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Sample records for 5-aminolevulinic acid-mediated photodynamic

  1. Therapeutic effects of topical 5-aminolevulinic acid photodynamic therapy

    PubMed Central

    Hu, Yin-E; Dai, Shu-Fang; Wang, Bin; Qu, Wei; Gao, Jun-Ling

    2016-01-01

    Objective: To evaluate the therapeutic effects of combined 5-aminolevulinic acid (ALA) and photodynamic therapy (PDT) on genital warts and the safety. Methods: One hundred ten patients with genital warts who were treated in our hospital from June 2013 to October 2014 were selected. The warts and affected parts were disinfected with benzalkonium bromide solution, and the warts were covered with absorbent cotton that had already been added freshly prepared 20% ALA solution, packaged and fixed. Then they were wet-dressed in dark, into which ALA solution was added according to the proportion of 5:3:2 every 30 minutes for three consecutive hours. Afterwards, the warts were illuminated by using photodynamic laser apparatus. The clinical outcomes, adverse reactions and recurrence rates were observed. Results: Genital warts were relieved in 107 out of the 110 cases (cure rate: 97.3%). Male patients had significantly better treatment outcomes at the urethral orifice than those in other affected parts. In the 107 patients, the cure rate of male patients was 98.8%, and they were cured after being treated four times. In contrast, female patients, who were cured after 5 times of treatment, had the cure rate of 91.7%. Their cure rates were similar (χ2=0, P>0.05), but the males were cured after significantly fewer times of treatment than the females (t=-7.432, P<0.05). Five patients suffered from mild tingling or burning sensation upon dressing at the urethral orifice, and the others were all free from systemic adverse reactions. After illumination, a small portion of the patients had mildly red, swelling, painful affected parts, with mild edema that almost disappeared within three days. Three patients relapsed at the urethral orifice and were then cured after further treatment. Conclusion: ALA-PDT can treat genital warts safely with high cure rate and low recurrence rate, particularly working for those of males at the urethral orifice. PMID:27648048

  2. Therapeutic effects of topical 5-aminolevulinic acid photodynamic therapy

    PubMed Central

    Hu, Yin-E; Dai, Shu-Fang; Wang, Bin; Qu, Wei; Gao, Jun-Ling

    2016-01-01

    Objective: To evaluate the therapeutic effects of combined 5-aminolevulinic acid (ALA) and photodynamic therapy (PDT) on genital warts and the safety. Methods: One hundred ten patients with genital warts who were treated in our hospital from June 2013 to October 2014 were selected. The warts and affected parts were disinfected with benzalkonium bromide solution, and the warts were covered with absorbent cotton that had already been added freshly prepared 20% ALA solution, packaged and fixed. Then they were wet-dressed in dark, into which ALA solution was added according to the proportion of 5:3:2 every 30 minutes for three consecutive hours. Afterwards, the warts were illuminated by using photodynamic laser apparatus. The clinical outcomes, adverse reactions and recurrence rates were observed. Results: Genital warts were relieved in 107 out of the 110 cases (cure rate: 97.3%). Male patients had significantly better treatment outcomes at the urethral orifice than those in other affected parts. In the 107 patients, the cure rate of male patients was 98.8%, and they were cured after being treated four times. In contrast, female patients, who were cured after 5 times of treatment, had the cure rate of 91.7%. Their cure rates were similar (χ2=0, P>0.05), but the males were cured after significantly fewer times of treatment than the females (t=-7.432, P<0.05). Five patients suffered from mild tingling or burning sensation upon dressing at the urethral orifice, and the others were all free from systemic adverse reactions. After illumination, a small portion of the patients had mildly red, swelling, painful affected parts, with mild edema that almost disappeared within three days. Three patients relapsed at the urethral orifice and were then cured after further treatment. Conclusion: ALA-PDT can treat genital warts safely with high cure rate and low recurrence rate, particularly working for those of males at the urethral orifice.

  3. Photodynamic therapy with 5-aminolevulinic acid: basic principles and applications

    NASA Astrophysics Data System (ADS)

    Pottier, Roy H.; Kennedy, James C.

    1996-01-01

    Numerous photosensitizing pigments that absorb visible light and are selectively retained in neoplastic tissue are being investigated as potential photochemotherapeutic agents. While much emphasis is being placed on the synthesis of new, far-red absorbing photosensitizers, an alternative approach has been to stimulate the human body to produce its own natural photosensitizer, namely protoporphyrin IX (PpIX). Exogenous 5-aminolevulinic acid (ALA) is rapidly bioconverted into PP by mitochondria, the process being particularly efficient in tumor cells. Since PpIX has a natural and rapid clearing mechanism (via the capture of iron in the process of being converted into heme), ALA-PDT does not suffer from lingering skin phototoxicity. ALA may be introduced orally, intravenously, or topically, and ALA-PDT has been shown to be effective in the treatment of both malignant and non-malignant lesions.

  4. Responses to hexyl 5-aminolevulinate-induced photodynamic treatment in rat bladder cancer model

    NASA Astrophysics Data System (ADS)

    Arum, Carl-Jørgen; Gederas, Odrun; Larsen, Eivind; Randeberg, Lise; Zhao, Chun-Mei

    2010-02-01

    OBJECTIVES: In this study, we evaluated histologically the effects of hexyl 5-aminolevulinateinduced photodynamic treatment in the AY-27 tumor cell induced rat bladder cancer model. MATERIAL & METHODS: The animals (fischer-344 female rats) were divided into 2 groups, half of which were orthotopically implanted with 400,000 syngeniec AY-27 urothelia1 rat bladder cancer cells and half sham implanted. 14 days post implantation 6 rats from each group were treated with hexyl 5-aminolevulinate-induced photodynamic treatment (8mM HAL and light fluence of 20 J/cm2). Additional groups of animals were only given HAL instillation, only light treatment, or no treatment. All animals were sacrificed 7 days after the PDT/only HAL/only light or no treatment. Each bladder was removed, embedded in paraffin and stained with hematoxylin, eosin, and saferin for histological evaluation at high magnification for features of tissue damage by a pathologist blinded to the sample source. RESULTS: In all animals that were AY-27 implanted and not given complete PDT treatment, viable tumors were found in the bladder mucosa and wall. In the animals treated with complete HAL-PDT only 3 of 6 animals had viable tumor. In the 3 animals with viable tumor it was significantly reduced in volume compared to the untreated animals. It was also noted that in the PDT treated animals there was a significantly increased inflammatory response (lymphocytic and mononuclear cell infiltration) in the peri-tumor area compared to implanted animals without complete HAL-PDT. CONCLUSION: Our results suggest that hexyl 5-aminolevulinate-induced photodynamic treatment in a rat bladder cancer model involves both direct effects on cell death (necrosis and apoptosis) and indirect effects to evoke the host immune-response, together contributing to tumor eradication.

  5. Enhanced 5-aminolevulinic acid-gold nanoparticle conjugate-based photodynamic therapy using pulse laser

    NASA Astrophysics Data System (ADS)

    Xu, Hao; Yao, Cuiping; Wang, Jing; Chang, Zhennan; Zhang, Zhenxi

    2016-02-01

    The low bioavailability is a crucial limitation for the application of 5-aminolevulinic acid (ALA) in theranostics. In this research, 5-aminolevulinic acid and gold nanoparticle conjugates (ALA-GNPs) were synthesized to improve the bioavailability of ALA and to investigate the impact of ALA photodynamic therapy (ALA-PDT) in Hela cells. A 532 nm pulse laser and light-emitting diode (central wavelengths 502 nm) were jointly used as light sources in PDT research. The results show a 532 nm pulse laser can control ALA release from ALA-GNPs by adjusting the pulse laser dose. This laser control release may be attributed to the heat generation from GNPs under pulse laser irradiation, which indicates accurately adjusting the pulse laser dose to control the drug release in the cell interior can be considered as a new cellular surgery modality. Furthermore, the PDT results in Hela cells indicate the enhancement of ALA release by pulse laser before PDT can promote the efficacy of cell eradication in the light-emitting diode PDT (LED-PDT). This laser mediated drug release system can provide a new online therapy approach in PDT and it can be utilized in the optical monitor technologies based individual theranostics.

  6. Utilization of 5-aminolevulinic acid in the photodynamic therapy of tumors: biochemical and photobiological aspects

    NASA Astrophysics Data System (ADS)

    Pottier, Roy H.; Kennedy, James C.

    1994-03-01

    Inherent in both plants and animals is the natural porphyrin, Protoporphyrin IX (Pp). Although Pp does not appear to have any intrinsic biological activity, it is a potent natural photosensitizer. When activated with ultraviolet or visible light, this photosensitizer can induce significant photodynamic effects on tissues, cells, subcellular elements, and macromolecules via the production of singlet oxygen. The biosynthesis of endogenous Pp is under strict enzymatic control. It is possible to bypass a rate controlling step and induce large, transient concentrations of Pp by the addition of exogenous 5-aminolevulinic acid (ALA). ALA may be administered systemically or topically. Much larger amounts of Pp are produced in certain types of tumor tissue than in adjacent normal tissue. Topically applied ALA can be used to treat a variety of skin lesions, including actinic keratosis, basal cell carcinomas and psoriasis.

  7. Fluorescence-guided resections and photodynamic therapy for malignant gliomas using 5-aminolevulinic acid

    NASA Astrophysics Data System (ADS)

    Stepp, Herbert G.; Beck, Tobias; Beyer, Wolfgang; Pongratz, Thomas; Sroka, Ronald; Baumgartner, Reinhold; Stummer, Walter; Olzowy, Bernhard; Mehrkens, Jan H.; Tonn, Joerg C.; Reulen, Hans J.

    2005-04-01

    Oral application of 20 mg/kg bw of 5-aminolevulinic acid results in a highly specific accumulation of fluorescent and phototoxic Protoporphyrin IX in malignant glioma tissue. Surgical removal with fluorescence guidance is studied in a phase III clinical trial, adjuvant Photodynamic Therapy (PDT) to the surgical cavity is in phase II and for interstitial PDT of recurrent gliomas, a phase I/II study has started. Fluorescence guided resections have been shown to be safe and effective in augmenting neurosurgical removal of malignant gliomas in 52 consecutive patients. Intra-operative fluorescence spectroscopy showed statistically significant higher sensitizer accumulation in vital brain tumor versus the infiltration zone and in the infiltration zone versus adjacent normal brain, which contained very little PPIX. This is promisingly exploited for PDT - both to the surgical cavity by surface irradiation and for stereotactically guided interstitial irradiation.

  8. Review of dermatology use of 5-aminolevulinic acid photodynamic therapy in China from 1997 to 2013

    NASA Astrophysics Data System (ADS)

    Wang, Peiru; Zhang, Guolong; Wang, Xiuli

    2015-07-01

    The prodrug 5-aminolevulinic acid (ALA) and its ester derivatives have been used in photodynamic therapy (PDT) in dermatology worldwide. In China, ALA-PDT was first used to treat urethral condylomata acuminata and non-melanoma skin cancers in 1997. A powder formulation of ALA hydrochloride was approved by the Chinese Food and Drug Administration for the treatment of condylomata acuminata in 2007. Large successful experience of treating condylomatas was accumulated compared with Western countries. Meanwhile, numerous clinical studies as well as off-label use of ALAPDT have been carried out in China. To reflect the progress of ALA-PDT in China, several major Chinese and English databases were searched and published data were reviewed in this article.

  9. Effectiveness of 5-aminolevulinic acid photodynamic therapy in the treatment of hidradenitis suppurativa: a report of 5 cases.

    PubMed

    Andino Navarrete, R; Hasson Nisis, A; Parra Cares, J

    2014-01-01

    Hidradenitis suppurativa has been described as a chronic, recurrent, and disabling inflammatory disease involving the entire hair follicle. Several treatments, including photodynamic therapy, have been used, but the results have been inconsistent and recurrence is high. In this prospective study, we evaluated disease severity, quality of life, and treatment tolerance in 5 patients with moderate to severe hidradenitis suppurativa treated with photodynamic therapy using 5-aminolevulinic acid and a 635-nm light source. Treatment effectiveness was evaluated using the Sartorius severity score, the Dermatology Life Quality Index, and a visual analog scale for pain and disease activity. Significant improvements were observed with all 3 instruments and the effects remained visible at 8 weeks. Our results suggest that photodynamic therapy with 5-aminolevulinic acid and a light wavelength of 635 nm could reduce disease severity and improve quality of life in patients with difficult-to-treat hidradenitis suppurativa.

  10. 5-Aminolevulinic Acid-Mediated Sonodynamic Therapy Inhibits RIPK1/RIPK3-Dependent Necroptosis in THP-1-Derived Foam Cells

    PubMed Central

    Tian, Fang; Yao, Jianting; Yan, Meng; Sun, Xin; Wang, Wei; Gao, Weiwei; Tian, Zhen; Guo, Shuyuan; Dong, Zengxiang; Li, Bicheng; Gao, Tielei; Shan, Peng; Liu, Bing; Wang, Haiyang; Cheng, Jiali; Gao, Qianping; Zhang, Zhiguo; Cao, Wenwu; Tian, Ye

    2016-01-01

    Necroptosis, or programmed necrosis, contributes to the formation of necrotic cores in atherosclerotic plaque in animal models. However, whether inhibition of necroptosis ameliorates atherosclerosis is largely unknown. In this study, we demonstrated that necroptosis occurred in clinical atherosclerotic samples, suggesting that it may also play an important role in human atherosclerosis. We established an in vitro necroptotic model in which necroptosis was induced in THP-1-derived foam cells by serum deprivation. With this model, we demonstrated that 5-aminolevulinic acid-mediated sonodynamic therapy (ALA-SDT) inhibited necroptosis while promoting apoptosis. ALA-SDT activated the caspase-3 and caspase-8 pathways in foam cells, which is responsible for the switch from necroptosis to apoptosis. The inhibition of either caspase-8 or caspase-3 abolished the anti-necroptotic effect of ALA-SDT. In addition, we found that caspase-3 activation peaked 4 hours after ALA-SDT treatment, 2 hours earlier than maximal caspase-8activation. Taken together, our data indicate that ALA-SDT mediates the switch from necroptosis to apoptosis by activating the caspase-3 and caspase-8 pathways and may improve the prognosis of atherosclerosis. PMID:26911899

  11. 5-Aminolevulinic Acid-Mediated Sonodynamic Therapy Inhibits RIPK1/RIPK3-Dependent Necroptosis in THP-1-Derived Foam Cells.

    PubMed

    Tian, Fang; Yao, Jianting; Yan, Meng; Sun, Xin; Wang, Wei; Gao, Weiwei; Tian, Zhen; Guo, Shuyuan; Dong, Zengxiang; Li, Bicheng; Gao, Tielei; Shan, Peng; Liu, Bing; Wang, Haiyang; Cheng, Jiali; Gao, Qianping; Zhang, Zhiguo; Cao, Wenwu; Tian, Ye

    2016-01-01

    Necroptosis, or programmed necrosis, contributes to the formation of necrotic cores in atherosclerotic plaque in animal models. However, whether inhibition of necroptosis ameliorates atherosclerosis is largely unknown. In this study, we demonstrated that necroptosis occurred in clinical atherosclerotic samples, suggesting that it may also play an important role in human atherosclerosis. We established an in vitro necroptotic model in which necroptosis was induced in THP-1-derived foam cells by serum deprivation. With this model, we demonstrated that 5-aminolevulinic acid-mediated sonodynamic therapy (ALA-SDT) inhibited necroptosis while promoting apoptosis. ALA-SDT activated the caspase-3 and caspase-8 pathways in foam cells, which is responsible for the switch from necroptosis to apoptosis. The inhibition of either caspase-8 or caspase-3 abolished the anti-necroptotic effect of ALA-SDT. In addition, we found that caspase-3 activation peaked 4 hours after ALA-SDT treatment, 2 hours earlier than maximal caspase-8activation. Taken together, our data indicate that ALA-SDT mediates the switch from necroptosis to apoptosis by activating the caspase-3 and caspase-8 pathways and may improve the prognosis of atherosclerosis. PMID:26911899

  12. Role of 5-aminolevulinic acid-conjugated gold nanoparticles for photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenxi; Wang, Sijia; Xu, Hao; Wang, Bo; Yao, Cuiping

    2015-05-01

    There are three possible mechanisms for 5-aminolevulinic acid (5-ALA) conjugated gold nanoparticles (GNPs) through electrostatic bonding for photodynamic therapy (PDT) of cancer: GNPs delivery function, singlet oxygen generation (SOG) by GNPs irradiated by light, and surface resonance enhancement (SRE) of SOG. Figuring out the exact mechanism is important for further clinical treatment. 5-ALA-GNPs and human chronic myeloid leukemia K562 cells were used to study delivery function and SOG by GNPs. The SRE of SOG enabled by GNPs was explored by protoporphyrin IX (PpIX)-GNPs conjugate through electrostatic bonding. Cell experiments show that the GNPs can improve the efficiency of PDT, which is due to the vehicle effect of GNPs. PpIX-GNPs conjugate experiments demonstrated that SOG can be improved about 2.5 times over PpIX alone. The experiments and theoretical results show that the local field enhancement (LFE) via localized surface plasmon resonance (LSPR) of GNPs is the major role; the LFE was dependent on the irradiation wavelength and the GNP's size. The LFE increased with an increase of the GNP size (2R ≤50 nm). However, the LSPR function of the GNPs was not found in cell experiments. Our study shows that in 5-ALA-conjugated GNPs PDT, the delivery function of GNPs is the major role.

  13. Rational design of 5-aminolevulinic acid derivatives aimed at improving photodynamic therapy.

    PubMed

    Casas, Adriana; Batlle, Alcira

    2002-07-01

    5-aminolevulinic acid (ALA) is the first intermediate in heme biosynthesis and is therefore a precursor of protoporphyrin IX (PpIX). PpIX is used as an endogenous photosensitizer in photodynamic therapy (PDT). Several chemical modifications have been made, both on the amino and carboxyl groups of ALA to induce higher PpIX production and photosensitisation. Esterification of ALA with aliphatic lineal and cyclic alcohols was found to reduce the amount of ALA required for photosensitization. Esterification by aliphatic alcohols with carbohydrate chains equal or lower than C4 leads to porphyrin accumulation lower than ALA, whereas equal or longer than C6 chains leads to greater synthesis of porphyrin. A branch point in the alcohol located next to the site of ester cleavage limits access of the esters to the esterase active site, resulting in lower PpIX production. ALA esters of the polyethylenglycol family can induce high levels of PpIX, with some selectivity for endothelial cells toward tumor cells. On the basis of the differential expression of some aminopeptidases in tumor vasculature when compared to normal vasculature, some ALA-pseudopeptides were synthesized. In a rational design of ALA derivatives, the transport mechanism of these aminoacids into the cell is central. Due to the similar characteristics between ALA and GABA transport, a novel approach for designing new ALA derivatives which could penetrate more easily into tumoral cells, would be to take into account the structures of the inhibitors of GABA transport. PMID:12678731

  14. Role of 5-aminolevulinic acid-conjugated gold nanoparticles for photodynamic therapy of cancer.

    PubMed

    Zhang, Zhenxi; Wang, Sijia; Xu, Hao; Wang, Bo; Yao, Cuiping

    2015-05-01

    There are three possible mechanisms for 5-aminolevulinic acid (5-ALA) conjugated gold nanoparticles (GNPs) through electrostatic bonding for photodynamic therapy (PDT) of cancer: GNPs delivery function,singlet oxygen generation (SOG) by GNPs irradiated by light, and surface resonance enhancement (SRE) of SOG. Figuring out the exact mechanism is important for further clinical treatment. 5-ALA-GNPs and human chronic myeloid leukemia K562 cells were used to study delivery function and SOG by GNPs. The SRE of SOG enabled by GNPs was explored by protoporphyrin IX (PpIX)-GNPs conjugate through electrostatic bonding.Cell experiments show that the GNPs can improve the efficiency of PDT, which is due to the vehicle effect of GNPs. PpIX–GNPs conjugate experiments demonstrated that SOG can be improved about 2.5 times over PpIX alone. The experiments and theoretical results show that the local field enhancement (LFE) via localized surface plasmon resonance (LSPR) of GNPs is the major role; the LFE was dependent on the irradiation wavelength and the GNP's size. The LFE increased with an increase of the GNP size (2R ≤ 50 nm). However, the LSPR function of the GNPs was not found in cell experiments. Our study shows that in 5-ALA-conjugated GNPs PDT, the delivery function of GNPs is the major role.

  15. Comparison of 5-aminolevulinic acid-encapsulated liposome versus ethosome for skin delivery for photodynamic therapy.

    PubMed

    Fang, Yi-Ping; Tsai, Yi-Hung; Wu, Pao-Chu; Huang, Yaw-Bin

    2008-05-22

    Topical photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) is an alternative therapy for many non-melanoma skin cancers. The major limitation of this therapy, however, is the low permeability of ALA through the stratum corneum (SC) of the skin. The objective of the present work was to characterize ethosomes containing ALA and to enhance the skin production of protoporphyrin IX (PpIX), compared to traditional liposomes. Results showed that the average particle sizes of the ethosomes were less than those of liposomes. Moreover, the entrapment efficiency of ALA in the ethosome formulations was 8-66% depending on the surfactant added. The particle size of the ethosomes was still approximately <200 nm after 32 days of storage. An in vivo animal study observed the presence of PpIX in the skin by confocal laser scanning microscopy (CLSM). The results indicated that the penetration ability of ethosomes was greater than that of liposomes. The enhancements of all the formulations were ranging from 11- to 15-fold in contrast to that of control (ALA in an aqueous solution) in terms of PpIX intensity. In addition, colorimetry detected no erythema in the irradiated skin. The results demonstrated that the enhancement ratio of ethosome formulations did not significantly differ between the non-irradiated and irradiated groups except for PE/CH/SS, which may have been due to a photobleaching effect of the PDT-irradiation process. PMID:18325699

  16. Photodynamic therapy of urethral condylomata acuminata using topically 5-aminolevulinic acid

    NASA Astrophysics Data System (ADS)

    Wang, Xiuli; Wang, Hongwei; Wang, Haishan; Xu, Shizheng; Liao, Kanghuang; Hillemanns, Peter

    2005-07-01

    Background Electrocoagulation and laser evaporation for urethral condylomata acuminata have high recurrence rates and can be associated with urethral malformations. Objective To investigate the effect of photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) on urethral condylomata acuminata and to examine the histological changes in lesions of condylomata acuminata after ALA-PDT. Methods One hundred and sixty-four urethral condylomata patients were given topical ALA followed by intraurethral PDT through a cylindrical fiber. Among the cases, 16 penile and vulval condylomatous lesions in 11 patients were treated with topical ALA-PDT at same time. After the treatment, biopsy specimens were collected from the 16 penile and vulval lesions. The histological changes were then evaluated by light microscope and electron microscope. Results The complete response rate for urethral condylomata by topical ALA-PDT was 95.12% and the recurrence rate was 5.13% after 6 to 24 months follow-up. Keratinocytes in middle and upper layers of the epidermis with marked vacuolation and some necrocytosis were detected one and three hours after PDT. Necrosis in all layers of the epidermis was noted five hours after PDT by microscopy. In electron microscopy of kerationcytes, distinct ultrastructural abnormalities of mitochondrion, endoplasmic reticulum and membrane damage were observed. Apoptotic bodies were detected three hours after PDT and a large number of the keratinocytes exhibited necrosis five hours after PDT by electron microscope. Conclusions Results suggests that topical ALA-PDT is a simple, effective, relatively safe, less recurrent and comparatively well tolerated treatment for urethral condylomata acuminata. The mechanisms might be that ALA-PDT could trigger apoptotic process and necrosis in the HPV infected keratinocytes. Key words:

  17. Hydrokolloid occlusive dressings for photodynamic therapy (PDT) of cutaneous lesions with endogenous porphyrins induced by 5-aminolevulinic acid

    NASA Astrophysics Data System (ADS)

    Gahlen, Johannes; Stern, Josef; Herfarth, Christian

    1995-03-01

    Protoporphyrin (Pp IX) is the final intermediate product before haem and can be stimulated to a phototoxic reaction with light. The presence of 5-aminolevulinic acid can increase the intracellular biosynthesis of Pp IX in certain types of tumor cells. The photosensitizing concentrations of Pp IX make laser light induced fluorescence diagnostics (LIFD) and photodynamic therapy possible. A topical application of a 5-aminolevulinic acid solution requires a waterproof occlusive dressing for several hours. We developed a simple technique for a practical preparation for PDT using a hydrocolloid dressing. The normal surrounding skin can be spared. We present our first therapeutic experience with a case of cutaneous breast cancer in a 65-year-old female patient. Six hours after topical application of 10% isotonic 5- aminolevulinic acid under the hydrocolloid dressing PDT was performed (Ar-Dye Laser, 630 nm wavelength). Twenty four hours after PDT a superficial tumor necrosis could be observed with a maximum depth of tumor necrosis of 2 - 3 mm. The surrounding normal skin was without any inflammation.

  18. Photodynamic therapy using systemic administration of 5-aminolevulinic acid and a 410-nm wavelength light-emitting diode for methicillin-resistant Staphylococcus aureus-infected ulcers in mice.

    PubMed

    Morimoto, Kuniyuki; Ozawa, Toshiyuki; Awazu, Kunio; Ito, Nobuhisa; Honda, Norihiro; Matsumoto, Sohkichi; Tsuruta, Daisuke

    2014-01-01

    Bacterial resistance to antibiotics has become a worldwide problem. One potential alternative for bacterial control is photodynamic therapy. 5-aminolevulinic acid is a natural precursor of the photosensitizer protoporphyrin IX. Relatively little is known about the antibacterial efficacy of photodynamic therapy using the systemic administration of 5-aminolevulinic acid; a few reports have shown that 5-aminolevulinic acid exerts photodynamic effects on methicillin-resistant Staphylococcus aureus (MRSA) in vitro. In this study, we evaluated the effectiveness of photodynamic therapy using 5-aminolevulinic acid and a 410-nm wavelength light-emitting diode in vitro and in vivo for the treatment of MRSA. We found that 5-aminolevulinic acid photodynamic therapy with the light-emitting diode had an in-vitro bactericidal effect on MRSA. In vivo, protoporphyrin IX successfully accumulated in MRSA on ulcer surfaces after intraperitoneal administration of 5-aminolevulinic acid to mice. Furthermore, 5-aminolevulinic acid photodynamic therapy accelerated wound healing and decreased bacterial counts on ulcer surfaces; in contrast, vancomycin treatment did not accelerate wound healing. Our findings indicate that 5-aminolevulinic acid photodynamic therapy may be a new treatment option for MRSA-infected wounds.

  19. Photodynamic Therapy Using Systemic Administration of 5-Aminolevulinic Acid and a 410-nm Wavelength Light-Emitting Diode for Methicillin-Resistant Staphylococcus aureus-Infected Ulcers in Mice

    PubMed Central

    Morimoto, Kuniyuki; Ozawa, Toshiyuki; Awazu, Kunio; Ito, Nobuhisa; Honda, Norihiro; Matsumoto, Sohkichi; Tsuruta, Daisuke

    2014-01-01

    Bacterial resistance to antibiotics has become a worldwide problem. One potential alternative for bacterial control is photodynamic therapy. 5-aminolevulinic acid is a natural precursor of the photosensitizer protoporphyrin IX. Relatively little is known about the antibacterial efficacy of photodynamic therapy using the systemic administration of 5-aminolevulinic acid; a few reports have shown that 5-aminolevulinic acid exerts photodynamic effects on methicillin-resistant Staphylococcus aureus (MRSA) in vitro. In this study, we evaluated the effectiveness of photodynamic therapy using 5-aminolevulinic acid and a 410-nm wavelength light-emitting diode in vitro and in vivo for the treatment of MRSA. We found that 5-aminolevulinic acid photodynamic therapy with the light-emitting diode had an in-vitro bactericidal effect on MRSA. In vivo, protoporphyrin IX successfully accumulated in MRSA on ulcer surfaces after intraperitoneal administration of 5-aminolevulinic acid to mice. Furthermore, 5-aminolevulinic acid photodynamic therapy accelerated wound healing and decreased bacterial counts on ulcer surfaces; in contrast, vancomycin treatment did not accelerate wound healing. Our findings indicate that 5-aminolevulinic acid photodynamic therapy may be a new treatment option for MRSA-infected wounds. PMID:25140800

  20. Cystic acne improved by photodynamic therapy with short-contact 5-aminolevulinic acid and sequential combination of intense pulsed light and blue light activation.

    PubMed

    Melnick, Stuart

    2005-01-01

    Photodynamic therapy with short-contact 5-aminolevulinic acid (Levulan Kerastick, Dusa Pharmaceuticals, Inc.) and activation by intense pulsed light in an initial treatment and blue light in 3 subsequent treatments has resulted in significant improvement in severity of acne, reduction in the number of lesions, improvement in skin texture, and smoothing of scar edges in an Asian patient with severe (class 4) facial cystic acne and scarring. PMID:16302560

  1. Photosensitizer fluorescence and singlet oxygen luminescence as dosimetric predictors of topical 5-aminolevulinic acid photodynamic therapy induced clinical erythema

    PubMed Central

    Mallidi, Srivalleesha; Anbil, Sriram; Lee, Seonkyung; Manstein, Dieter; Elrington, Stefan; Kositratna, Garuna; Schoenfeld, David; Pogue, Brian; Davis, Steven J.; Hasan, Tayyaba

    2014-01-01

    Abstract. The need for patient-specific photodynamic therapy (PDT) in dermatologic and oncologic applications has triggered several studies that explore the utility of surrogate parameters as predictive reporters of treatment outcome. Although photosensitizer (PS) fluorescence, a widely used parameter, can be viewed as emission from several fluorescent states of the PS (e.g., minimally aggregated and monomeric), we suggest that singlet oxygen luminescence (SOL) indicates only the active PS component responsible for the PDT. Here, the ability of discrete PS fluorescence-based metrics (absolute and percent PS photobleaching and PS re-accumulation post-PDT) to predict the clinical phototoxic response (erythema) resulting from 5-aminolevulinic acid PDT was compared with discrete SOL (DSOL)-based metrics (DSOL counts pre-PDT and change in DSOL counts pre/post-PDT) in healthy human skin. Receiver operating characteristic curve (ROC) analyses demonstrated that absolute fluorescence photobleaching metric (AFPM) exhibited the highest area under the curve (AUC) of all tested parameters, including DSOL based metrics. The combination of dose-metrics did not yield better AUC than AFPM alone. Although sophisticated real-time SOL measurements may improve the clinical utility of SOL-based dosimetry, discrete PS fluorescence-based metrics are easy to implement, and our results suggest that AFPM may sufficiently predict the PDT outcomes and identify treatment nonresponders with high specificity in clinical contexts. PMID:24503639

  2. Improvement of systemic 5-aminolevulinic acid-based photodynamic therapy in vivo using light fractionation with a 75-minute interval.

    PubMed

    de Bruijn, H S; van der Veen, N; Robinson, D J; Star, W M

    1999-02-15

    We have studied different single and fractionated illumination schemes after systemic administration of 5-aminolevulinic acid (ALA) to Improve the response of nodular tumors to ALA-mediated photodynamic therapy. Tumors transplanted on the thigh of female WAG/Rij rats were transdermally illuminated with red light (633 nm) after systemic ALA administration (200 mg/kg). The effectiveness of each treatment scheme was determined from the tumor volume doubling time. A single illumination (100 J/cm2 at 100 mW/cm2, 2.5 h after ALA administration) yielded a doubling time of 6.6+/-1.2 days. This was significantly different from the untreated control (doubling time, 1.7+/-0.1 days). The only treatment scheme that yielded a significant improvement compared to all other schemes studied was illumination at both 1 and 2.5 h after ALA administration (both 100 J/cm2 at 100 mW/cm2) and resulted in a tumor volume doubling time of 18.9+/-2.9 days. A possible mechanism to explain this phenomenon is that the protoporphyrin IX formed after administration of ALA is photodegraded by the first illumination. In the 75-min interval, new porphyrin is formed enhancing the effect of the second illumination. PMID:10029082

  3. Prospective study of topical 5-aminolevulinic acid photodynamic therapy for the treatment of severe adolescent acne in Chinese patients.

    PubMed

    Ma, Ying; Liu, Ye; Wang, Qianqian; Ren, Jie; Xiang, Leihong

    2015-05-01

    Acne vulgaris is one of the most common skin diseases in adolescents. In the present study, we aimed to evaluate the effectiveness and safety of topical 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) for the treatment of severe acne in Chinese adolescent patients. Twenty-one Chinese adolescent patients aged 12-18 years with Pillsbury III-IV severe facial acne were treated with three courses of ALA-PDT. A 5% ALA lotion was applied topically for 60 min followed by irradiation with light-emitting diode light at 633 nm with a light intensity of 75-80 mW/cm(2) and a light dose of 90-96 J/cm(2) . Clinical assessment was conducted before and after each treatment, and at each follow-up session. The total effective rates were 85.71%, 90.48%, and 95.23% after the three PDT sessions, and at the 4- and 8-week follow ups, respectively. ALA-PDT is an effective treatment for severe adolescent acne vulgaris, and is associated with mild and reversible side-effects.

  4. Topical photodynamic therapy with 5-aminolevulinic acid in the treatment of actinic keratoses: a first clinical study

    NASA Astrophysics Data System (ADS)

    Karrer, Sigrid; Szeimies, Rolf-Markus; Sauerwald, Angela; Landthaler, Michael

    1996-01-01

    In this first clinical study performed according to GCP- (good clinical practice) guidelines, efficacy, and tolerability of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) were tested in the treatment of actinic keratoses. Ten patients (6 f, 4 m) with 36 lesions (19 located on hands and arms, 17 on the head) received ALA-PDT once. Five to six hours after occlusive application of ALA (water-in-oil-emulsion containing 10% ALA) irradiation was performed with an incoherent light source. Up to 3 months after treatment patients were monitored. A score evaluating infiltration and keratosis of treated actinic keratoses allowed us to estimate therapeutic efficacy. Compared to the initial score (100%) significantly lower score-sums were observed at the 28 day follow-up at both localizations (head: 15%; hand: 67%). Complete remission (score sum 0) resulted in 71% of actinic keratoses localized on the head. Except for slight pain and burning sensations during and after irradiation there were no notable side effects. This study proved good efficacy and tolerability of topical PDT in the treatment of actinic keratoses. Whether PDT is able to compete with established treatment modalities remains to be shown in further studies.

  5. Needle-free injection of 5-aminolevulinic acid in photodynamic therapy for the treatment of condylomata acuminata

    PubMed Central

    LI, XIULI; WANG, XIUXIU; GU, JUNYING; MA, YUE’E; LIU, ZHIYU; SHI, YULING

    2013-01-01

    The external application of 5-aminolevulinic acid (ALA) in photodynamic therapy (PDT) results in a shallow penetration depth in thick or extensive condylomata acuminata (CA) lesions, thus demonstrating a poor therapeutic effect for those patients. To compare the efficacy of needle-free injection with external application of ALA in PDT for the treatment of CA, 160 CA patients with thick or extensive warts received ALA-PDT by means of external application or needle-free injection of ALA, respectively. The complete response (CR) rate and recurrence rate in the two groups were analyzed. The CR rate after the first treatment in the needle-free injection group (68.8%) was significantly higher compared with that in the external application group (52.5%; P=0.035). The recurrence rates in the needle-free injection group and external application group were 4.1 and 15.4%, respectively (P=0.022). The needle-free injection of ALA increases the therapeutic effect of PDT for CA patients with thick or extensive lesions. It shortens the treatment time and reduces the recurrence rate, and has great potential in the treatment of CA. PMID:23935753

  6. In vitro skin permeation and retention of 5-aminolevulinic acid ester derivatives for photodynamic therapy.

    PubMed

    De Rosa, Fernanda Scarmato; Tedesco, Antônio Cláudio; Lopez, Renata Fonseca Vianna; Pierre, Maria Bernadete Riemma; Lange, Norbert; Marchetti, Juliana Maldonado; Rotta, Jeane Cristina Gomes; Bentley, Maria Vitória Lopes Badra

    2003-04-29

    In photodynamic therapy (PDT), 5-aminiolevulinic acid (5-ALA) applied topically is converted, via the heme cycle, into protoporphyrin IX (PpIX), a photosensitizing agent, which upon excitation with light can induce tumor destruction. Due to its hydrophilic and zwitterionic characteristics, 5-ALA has limited penetration into the skin. More lipophilic 5-ALA ester derivatives are expected to cross stratum corneum more easily than 5-ALA. According to the determination of the partition coefficients of 5-ALA methyl, n-butyl, n-hexyl and n-octyl esters, these compounds showed an increased affinity to the SC, with 5-ALA hexyl ester and 5-ALA-octyl ester having the highest partition coefficients. Our in vitro skin permeation studies demonstrated an increased permeated amount for hexyl-ALA after 6 h of incubation, compared to other esters and 5-ALA. After 6 h, more 5-ALA-hexyl ester and -octyl ester were retained at viable epidermis and dermis than 5-ALA. According to these results, and considering that the conversion of 5-ALA into PpIX occurs preferentially in epidermis, it can be supposed that topical use of ester derivatives with longer chains (C(6) or C(8)) is an interesting proposal to optimize topical 5-ALA-PDT

  7. Comparative split-face study of 5-aminolevulinic acid photodynamic therapy with intense pulsed light for photorejuvenation of Asian skin.

    PubMed

    Kosaka, Sachiko; Yasumoto, Minako; Akilov, Oleg E; Hasan, Tayyaba; Kawana, Seiji

    2010-12-01

    Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) (ALA-PDT) using intense pulsed light (IPL) as a light source (IPL-ALA-PDT) has been used for photorejuvenation, but it is unclear if this protocol can be applied to darker skin types. We performed this study to assess our IPL-ALA-PDT protocol for photorejuvenation in Asian skin. To determine an appropriate dose, ALA ointment (0-20%) was applied to the upper arm of five healthy volunteers and the fluorescence intensity (FI) was measured using a spectrofluorometer. Non-linear regression analysis of FI 2 h after ALA application with global fitting gave a typical sigmoid dose-response curve with R² = 0.9705 and saturation after 5% ALA. The entire faces of 16 Japanese women with photodamage were then treated with IPL (500-670 and 870-1400 nm, 23-30 J/cm²) 2 h after application of 5% ALA to one side of the face. Three treatments were delivered at 4-week intervals with follow-up visits. Comparative analysis of photorejuvenation showed noticeable improvements on both sides of the face, although the reduction in the photoaging score from baseline did not differ significantly between the two sides in all subjects. Despite this finding, 75% of the patients felt that the IPL-ALA-PDT-treated side of the face showed greater improvement than the IPL-treated side. However, all IPL-ALA-PDT-treated sides showed adverse effects such as erythema and pain. Therefore, we conclude that the IPL-ALA-PDT protocol requires optimization for photorejuvenation in Asians.

  8. In Vitro Comparison of Hypericin and 5-Aminolevulinic Acid-Derived Protoporphyrin IX for Photodynamic Inactivation of Medulloblastoma Cells

    PubMed Central

    Ritz, Rainer; Scheidle, Christian; Noell, Susan; Roser, Florian; Schenk, Martin; Dietz, Klaus; Strauss, Wolfgang S. L.

    2012-01-01

    Background Hypericin (HYP) is a naturally occurring photosensitizer. Cellular uptake and photodynamic inactivation after incubation with this photosensitizer have neither been examined in medulloblastoma cells in vitro, nor compared with 5-aminolevulinic acid-derived protoporphyrin IX (5-ALA-derived PpIX). Methods In 3 medulloblastoma cell lines (D283 Med, Daoy, and D341 Med) the time- and concentration-dependent intracellular accumulation of HYP and 5-ALA-derived PpIX was analyzed by fluorescence microscopy (FM) and FACS. Photocytotoxicity was measured after illumination at 595 nm (HYP) and 635 nm (5-ALA-derived PpIX) in D283 Med cells and compared to U373 MG glioma cells. Results All medulloblastoma cell lines exhibited concentration- and time-dependent uptake of HYP. Incubation with HYP up to 10 µM resulted in a rapid increase in fluorescence intensity, which peaked between 2 and 4 hours. 5-ALA-derived PpIX accumulation increased in D283 Med cells by 22% over baseline after 5-ALA incubation up to 1.2 mM. Photocytotoxicity of 5-ALA-derived PpIX was higher in D283 Med medulloblastoma compared to U373MG glioma. The [lethal dose (light dose that is required to reduce cell survival to 50% of control)] of 5-ALA-derived PpIX was 3.8 J/cm2 in D283 Med cells versus 5.7 J/cm2 in U373MG glioma cells. Photocytotoxicity of HYP in D283 Med cells was determined at 2.5 µM after an incubation time of 2 h and an illumination wavelength of 595 nm. The value was 0.47 J/cm2. Conclusion By its 5-fold increase in fluorescence over autofluorescence levels HYP has excellent properties for tumor visualization in medulloblastomas. The high photocytotoxicity of HYP, compared to 5-ALA-derived PpIX, is convincingly demonstrated by its 8- to 13-fold lower . Therefore HYP might be a promising molecule for intraoperative visualization and photodynamic treatment of medulloblastomas. PMID:23251668

  9. Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen.

    PubMed

    Phung, Thu-Ha; Jung, Sunyo

    2015-04-01

    This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, Fv/Fm, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H2O2 production and greater increases in H2O2-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redox state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage.

  10. Red versus blue light illumination in hexyl 5-aminolevulinate photodynamic therapy: the influence of light color and irradiance on the treatment outcome in vitro.

    PubMed

    Helander, Linda; Krokan, Hans E; Johnsson, Anders; Gederaas, Odrun A; Plaetzer, Kristjan

    2014-08-01

    Hexyl 5-aminolevulinate (HAL) is a lipophilic derivative of 5-aminolevulinate, a key intermediate in biosynthesis of the photosensitizer protoporphyrin IX (PpIX). The photodynamic efficacy and cell death mode after red versus blue light illumination of HAL-induced PpIX have been examined and compared using five different cancer cell lines. LED arrays emitting at 410 and 624 nm served as homogenous and adjustable light sources. Our results show that the response after HAL-PDT is cell line specific, both regarding the shape of the dose-survival curve, the overall dose required for efficient cell killing, and the relative amount of apoptosis. The ratio between 410 and 624 nm in absorption coefficient correlates well with the difference in cell killing at the same wavelengths. In general, the PDT efficacy was several folds higher for blue light as compared with red light, as expected. However, HAL-PDT₆₂₄ induced more apoptosis than HAL-PDT₄₁₀ and illumination with low irradiance resulted in more apoptosis than high irradiance at the same lethal dose. This indicates differences in death modes after low and high irradiance after similar total light doses. From a treatment perspective, these differences may be important.

  11. Red versus blue light illumination in hexyl 5-aminolevulinate photodynamic therapy: the influence of light color and irradiance on the treatment outcome in vitro

    NASA Astrophysics Data System (ADS)

    Helander, Linda; Krokan, Hans E.; Johnsson, Anders; Gederaas, Odrun A.; Plaetzer, Kristjan

    2014-08-01

    Hexyl 5-aminolevulinate (HAL) is a lipophilic derivative of 5-aminolevulinate, a key intermediate in biosynthesis of the photosensitizer protoporphyrin IX (PpIX). The photodynamic efficacy and cell death mode after red versus blue light illumination of HAL-induced PpIX have been examined and compared using five different cancer cell lines. LED arrays emitting at 410 and 624 nm served as homogenous and adjustable light sources. Our results show that the response after HAL-PDT is cell line specific, both regarding the shape of the dose-survival curve, the overall dose required for efficient cell killing, and the relative amount of apoptosis. The ratio between 410 and 624 nm in absorption coefficient correlates well with the difference in cell killing at the same wavelengths. In general, the PDT efficacy was several folds higher for blue light as compared with red light, as expected. However, HAL-PDT624 induced more apoptosis than HAL-PDT410 and illumination with low irradiance resulted in more apoptosis than high irradiance at the same lethal dose. This indicates differences in death modes after low and high irradiance after similar total light doses. From a treatment perspective, these differences may be important.

  12. Differential antioxidant defense and detoxification mechanisms in photodynamically stressed rice plants treated with the deregulators of porphyrin biosynthesis, 5-aminolevulinic acid and oxyfluorfen

    SciTech Connect

    Phung, Thu-Ha; Jung, Sunyo

    2015-04-03

    This study focuses on differential molecular mechanisms of antioxidant and detoxification systems in rice plants under two different types of photodynamic stress imposed by porphyrin deregulators, 5-aminolevulinic acid (ALA) and oxyfluorfen (OF). The ALA-treated plants with white necrosis exhibited a greater decrease in photochemical quantum efficiency, F{sub v}/F{sub m}, as well as a greater increase in activity of superoxide dismutase, compared to the OF-treated plants. By contrast, the brown necrosis in OF-treated plants resulted in not only more widely dispersed H{sub 2}O{sub 2} production and greater increases in H{sub 2}O{sub 2}-decomposing enzymes, catalase and peroxidase, but also lower ascorbate redox state. In addition, ALA- and OF-treated plants markedly up-regulated transcript levels of genes involved in detoxification processes including transport and movement, cellular homeostasis, and xenobiotic conjugation, with prominent up-regulation of serine/threonine kinase and chaperone only in ALA-treated plants. Our results demonstrate that different photodynamic stress imposed by ALA and OF developed differential actions of antioxidant enzymes and detoxification. Particularly, detoxification system may play potential roles in plant protection against photodynamic stress imposed by porphyrin deregulators, thereby contributing to alleviation of photodynamic damage. - Highlights: • We employ two different types of photodynamic stress, white and brown necrosis. • We examine molecular mechanisms of antioxidative and detoxification systems. • ALA and OF develop differential actions of antioxidant and detoxification systems. • Coordinated mechanism of antioxidants and detoxification works against toxic ROS. • Detoxification system plays critical roles in protection against photodynamic stress.

  13. Treatment of moderate to severe inflammatory acne vulgaris: photodynamic therapy with 5-aminolevulinic acid and a novel advanced fluorescence technology pulsed light source.

    PubMed

    Gold, Michael H; Biron, Julie A; Boring, Molly; Bridges, Tancy M; Bradshaw, Virginia L

    2007-03-01

    The use of photodynamic therapy (PDT) with 20% 5-aminolevulinic acid (ALA) for the treatment of acne vulgaris has been explored. This study evaluates the safety and efficacy of a new Advanced Fluorescence Technology (AFT) pulsed light source (420-950 nm) for photoactivation in ALA PDT for the treatment of moderate to severe inflammatory facial acne vulgaris. Nineteen subjects received 4 ALA PDT treatments with the AFT pulsed light source. Treatments were spaced 2 weeks apart. ALA was incubated for 15 to 30 minutes. At the end of the fourth treatment, the total reductions in inflammatory and noninflammatory lesion counts were 54.5% and 37.5%, respectively. Median Global Severity Scores suggest a trend toward reduction after several treatments. Investigator and subject assessments show moderate to marked improvement in most patients. The new AFT pulsed light source with ALA PDT appears to be a safe and effective modality for the treatment of moderate to severe inflammatory acne vulgaris.

  14. Complete resolution of a squamous cell carcinoma of the skin using intralesional 5-aminolevulinic acid photodynamic therapy intralesional PDT for SCC.

    PubMed

    Sotiriou, Eleni; Apalla, Zoi; Ioannides, Demetris

    2010-10-01

    We present an 82-year-old female patient with a 2-year history of an infiltrative squamous cell carcinoma (SCC) on her right cheek. The patient was treated with one intralesional photodynamic therapy (PDT) session using 10% 5-aminolevulinic acid solution. We used red light by a non-coherent light source at a light dose of 100 J/cm² and a fluency rate of 100 mW/cm². Complete clinical and histological response was achieved 3 months after the treatment procedure. Cosmetic outcome was evaluated as fair. The patient remains disease free with the absence of any clinical sign of recurrence 16 months after PDT. Long-term follow-up is needed for assessment of recurrences. Optimization of the therapeutic protocol, as well as justification of our results in larger studies are needed in order to elicit safe conclusions.

  15. Treating cutaneous squamous cell carcinoma using 5-aminolevulinic acid polylactic-co-glycolic acid nanoparticle-mediated photodynamic therapy in a mouse model

    PubMed Central

    Wang, Xiaojie; Shi, Lei; Tu, Qingfeng; Wang, Hongwei; Zhang, Haiyan; Wang, Peiru; Zhang, Linglin; Huang, Zheng; Zhao, Feng; Luan, Hansen; Wang, Xiuli

    2015-01-01

    Background Squamous cell carcinoma (SCC) is a common skin cancer, and its treatment is still difficult. The aim of this study was to evaluate the effectiveness of nanoparticle (NP)-assisted 5-aminolevulinic acid (ALA) delivery for topical photodynamic therapy (PDT) of cutaneous SCC. Materials and methods Ultraviolet-induced cutaneous SCCs were established in hairless mice. ALA-loaded polylactic-co-glycolic acid (PLGA) NPs were prepared and characterized. The kinetics of ALA PLGA NP-induced protoporphyrin IX fluorescence in SCCs, therapeutic efficacy of ALA NP-mediated PDT, and immune responses were examined. Results PLGA NPs enhanced protoporphyrin IX production in SCC. ALA PLGA NP-mediated topical PDT was more effective than free ALA of the same concentration in treating cutaneous SCC. Conclusion PLGA NPs provide a promising strategy for delivering ALA in topical PDT of cutaneous SCC. PMID:25609949

  16. eEF1A1 binds and enriches protoporphyrin IX in cancer cells in 5-aminolevulinic acid based photodynamic therapy.

    PubMed

    Fan, Zhichao; Cui, Xiaojun; Wei, Dan; Liu, Wei; Li, Buhong; He, Hao; Ye, Huamao; Zhu, Naishuo; Wei, Xunbin

    2016-01-01

    Photodynamic therapy (PDT) with protoporphyrin IX (PpIX), which is endogenously derived from 5-aminolevulinic acid (5-ALA) or its derivatives, is a promising modality for the treatment of both pre-malignant and malignant lesions. However, the mechanisms of how ALA-induced PpIX selectively accumulated in the tumors are not fully elucidated. Here we discovered that eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) interacted with PpIX (with an affinity constant of 2.96 × 10(6) M(-1)). Microscopy imaging showed that ALA-induced PpIX was co-localized with eEF1A1 in cancer cells. eEF1A1 was found to enrich ALA-induced PpIX in cells by competitively blocking the downstream bioavailability of PpIX. Taken together, our study discovered eEF1A1 as a novel photosensitizer binding protein, which may play an essential role in the enrichment of ALA-induced PpIX in cancer cells during PDT. These suggested eEF1A1 as a molecular marker to predict the selectivity and efficiency of 5-ALA based PDT in cancer therapy. PMID:27150264

  17. Photodynamic therapy of superficial basal cell carcinoma with 5-aminolevulinic acid with dimethylsulfoxide and ethylendiaminetetraacetic acid: a comparison of two light sources.

    PubMed

    Soler, A M; Angell-Petersen, E; Warloe, T; Tausjø, J; Steen, H B; Moan, J; Giercksky, K E

    2000-06-01

    The aim of this prospective randomized study was to compare the clinical and cosmetic outcome of superficial basal cell carcinomas (BCC), using either laser or broadband halogen light, in photodynamic therapy with topical 5-aminolevulinic acid (ALA). A total of 83 patients with 245 superficial BCC were included in the study. Standard treatment involved 15 min of local pretreatment with 99% dimethylsulfoxide (DMSO) before topical application of 20% ALA with DMSO (2%) and ethylendiaminetetraacetic acid (2%) as cofactors for 3 h before light exposure with either laser or a broadband lamp (BL). A complete response was achieved in 95 lesions (86%) in the laser group and 110 lesions (82%) in the BL group 6 months after treatment. Of these, 80 lesions (84%) in the laser group and 101 lesions (92%) in the lamp group were independently evaluated to have an excellent or good cosmetic post-treatment score. No serious adverse events were reported. This study shows that there is no statistical significant difference in cure the rate (P = 0.49) and the cosmetic outcome (P = 0.075) with topical application of a modified ALA-cream between light exposure from a simple BL with continuous spectrum (570-740 nm) or from a red-light laser (monochromatic 630 nm). Cost and safety are further elements in favor of the BL in this setting.

  18. Inhibition of MAPK signaling pathways enhances cell death induced by 5-Aminolevulinic acid-photodynamic therapy in skin squamous carcinoma cells.

    PubMed

    Ge, Xinhong; Liu, Jianping; Shi, Zhiyun; Jing, Li; Yu, Nan; Zhang, Xiujuan; Jiao, Yaning; Wang, Yili; Li, P Andy

    2016-04-01

    Combination of a photosensitizer, 5-aminolevulinic acid (ALA), with photodynamic therapy (PDT) has been widely used to treat skin squamous cell carcinoma (SCC). However, a portion of SCC patients do not respond well to PDT. The molecular reason for this resistance is not clear. We hypothesize that mitogen-activated phosphorylation kinase (MAPK) plays a key role in mediating SCC resistance to PDT. To determine whether inhibition of MAPK signaling enhances the anti-tumor effect of ALA-PDT in SCC. The human squamous carcinoma cell line, SCL-1, was either untreated or treated with various combinations of ALA, PDT light source and inhibitors of MAPK signaling components. ALA-PDT treatment significantly decreased cell viability, increased the percentage of annexin-V positive cells and resulted in formation of apoptotic bodies. ALA-PDT treated cells showed increased levels of p-MEK, p-ERK1/2, p-p38, p-Elk-1, p-JNK and p-c-Jun. Addition of inhibitors for ERK1/2 (PD98059), p38 (SB203580) and JNK (SP60125) reversed the changes and led to a more dramatic decrease in SCL-1 cell viability than seen with ALA-PDT alone. Inhibition of the MAPK pathway enhances the cytotoxic effect of ALA-PDT on SCL-1.

  19. eEF1A1 binds and enriches protoporphyrin IX in cancer cells in 5-aminolevulinic acid based photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Fan, Zhichao; Cui, Xiaojun; Wei, Dan; Liu, Wei; Li, Buhong; He, Hao; Ye, Huamao; Zhu, Naishuo; Wei, Xunbin

    2016-05-01

    Photodynamic therapy (PDT) with protoporphyrin IX (PpIX), which is endogenously derived from 5-aminolevulinic acid (5-ALA) or its derivatives, is a promising modality for the treatment of both pre-malignant and malignant lesions. However, the mechanisms of how ALA-induced PpIX selectively accumulated in the tumors are not fully elucidated. Here we discovered that eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) interacted with PpIX (with an affinity constant of 2.96 × 106 M‑1). Microscopy imaging showed that ALA-induced PpIX was co-localized with eEF1A1 in cancer cells. eEF1A1 was found to enrich ALA-induced PpIX in cells by competitively blocking the downstream bioavailability of PpIX. Taken together, our study discovered eEF1A1 as a novel photosensitizer binding protein, which may play an essential role in the enrichment of ALA-induced PpIX in cancer cells during PDT. These suggested eEF1A1 as a molecular marker to predict the selectivity and efficiency of 5-ALA based PDT in cancer therapy.

  20. Wavelength-dependent in-vitro and in-vivo photodynamic effects after sensitization with 5-aminolevulinic acid induced protoporphyrin IX

    NASA Astrophysics Data System (ADS)

    Szeimies, Rolf-Markus; Abels, Christoph; Fritsch, Clemens; Steinbach, Pia; Baeumler, Wolfgang; Messmann, Helmut; Goetz, Alwin E.; Goerz, Guenter; Landthaler, Michael

    1996-01-01

    Photodynamic therapy (PDT) with topically applied 5-aminolevulinic acid (ALA) is of growing interest, in particular in dermatology. Due to the fact that PDT with intravenously administered Photofrin is the only clinically approved sensitizer so far and is performed at a wavelength of 630 nm, this wavelength is also used in most experimental and clinical trials with ALA. In this study influence of irradiation with coherent light from a tunable dye laser at different wavelengths ranging from 625 to 649 nm was investigated. In in vitro experiments HaCaT immortalized human keratinocytes were sensitized with 30 (mu) g/ml ALA for 24 hrs. By determination of cell viability with the MTT test, best cell-killing effects were observed following irradiation at 635 nm. In an in vivo setting using an amelanotic melanoma (A-Mel-3) grown subcutaneously in Syrian Golden hamsters, these results were confirmed: tumor growth determined by measuring tumor volume increase after 28 days was less pronounced in animals treated with 100 mg/kg ALA i.v. and irradiated 2.5 hrs. later at 635 nm, as compared to animals receiving an equal dose and irradiated at 630 nm. This observation in vitro is probably due to large amounts of photosensitizing protoporphyrin IX (PP) localized in cell membranes which is visualized by confocal laser scanning microscopy (CLSM) and determined by HPLC analysis. These results suggest that in ALA-PDT when a coherent light source is used probably better results are achieved irradiating at 635 nm.

  1. Inhibition of MAPK signaling pathways enhances cell death induced by 5-Aminolevulinic acid-photodynamic therapy in skin squamous carcinoma cells.

    PubMed

    Ge, Xinhong; Liu, Jianping; Shi, Zhiyun; Jing, Li; Yu, Nan; Zhang, Xiujuan; Jiao, Yaning; Wang, Yili; Li, P Andy

    2016-04-01

    Combination of a photosensitizer, 5-aminolevulinic acid (ALA), with photodynamic therapy (PDT) has been widely used to treat skin squamous cell carcinoma (SCC). However, a portion of SCC patients do not respond well to PDT. The molecular reason for this resistance is not clear. We hypothesize that mitogen-activated phosphorylation kinase (MAPK) plays a key role in mediating SCC resistance to PDT. To determine whether inhibition of MAPK signaling enhances the anti-tumor effect of ALA-PDT in SCC. The human squamous carcinoma cell line, SCL-1, was either untreated or treated with various combinations of ALA, PDT light source and inhibitors of MAPK signaling components. ALA-PDT treatment significantly decreased cell viability, increased the percentage of annexin-V positive cells and resulted in formation of apoptotic bodies. ALA-PDT treated cells showed increased levels of p-MEK, p-ERK1/2, p-p38, p-Elk-1, p-JNK and p-c-Jun. Addition of inhibitors for ERK1/2 (PD98059), p38 (SB203580) and JNK (SP60125) reversed the changes and led to a more dramatic decrease in SCL-1 cell viability than seen with ALA-PDT alone. Inhibition of the MAPK pathway enhances the cytotoxic effect of ALA-PDT on SCL-1. PMID:27032574

  2. eEF1A1 binds and enriches protoporphyrin IX in cancer cells in 5-aminolevulinic acid based photodynamic therapy

    PubMed Central

    Fan, Zhichao; Cui, Xiaojun; Wei, Dan; Liu, Wei; Li, Buhong; He, Hao; Ye, Huamao; Zhu, Naishuo; Wei, Xunbin

    2016-01-01

    Photodynamic therapy (PDT) with protoporphyrin IX (PpIX), which is endogenously derived from 5-aminolevulinic acid (5-ALA) or its derivatives, is a promising modality for the treatment of both pre-malignant and malignant lesions. However, the mechanisms of how ALA-induced PpIX selectively accumulated in the tumors are not fully elucidated. Here we discovered that eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) interacted with PpIX (with an affinity constant of 2.96 × 106 M−1). Microscopy imaging showed that ALA-induced PpIX was co-localized with eEF1A1 in cancer cells. eEF1A1 was found to enrich ALA-induced PpIX in cells by competitively blocking the downstream bioavailability of PpIX. Taken together, our study discovered eEF1A1 as a novel photosensitizer binding protein, which may play an essential role in the enrichment of ALA-induced PpIX in cancer cells during PDT. These suggested eEF1A1 as a molecular marker to predict the selectivity and efficiency of 5-ALA based PDT in cancer therapy. PMID:27150264

  3. Tissue responses to hexyl 5-aminolevulinate-induced photodynamic treatment in syngeneic orthotopic rat bladder cancer model: possible pathways of action

    NASA Astrophysics Data System (ADS)

    Arum, Carl-Jørgen; Gederaas, Odrun A.; Larsen, Eivind L. P.; Randeberg, Lise L.; Hjelde, Astrid; Krokan, Hans E.; Svaasand, Lars O.; Chen, Duan; Zhao, Chun-Mei

    2011-02-01

    Orthotopic bladder cancer model in rats mimics human bladder cancer with respect to urothelial tumorigenesis and progression. Utilizing this model at pT1 (superficial stage), we analyze the tissue responses to hexyl 5-aminolevulinate-induced photodynamic therapy (HAL-PDT). In comparison to untreated rats, HAL-PDT causes little change in tumor-free rat bladder but induces inflammatory changes with increased lymphocytes and mononuclear cell infiltration in rat bladders with tumor. Immunohistochemistry reveals that HAL-PDT is without effect on proliferating cell nuclear antigen expression within the tumor and increases caspase-3 expression in both normal urothelium and the tumor. Transmission electron microscopy reveals severe mitochondrial damage, formations of apoptotic bodies, vacuoles, and lipofuscin bodies, but no microvillus-formed niches in HAL-PDT-treated bladder cancer rats. Bioinformatics analysis of the gene expression profile indicates an activation of T-cell receptor signaling pathway in bladder cancer rats without PDT. HAL-PDT increases the expression of CD3 and CD45RA in the tumor (determined by immunohistochemistry). We suggest that pathways of action of HAL-PDT may include, at least, activations of mitochondrial apoptosis and autophagy, breakdown of cancer stem cell niches, and importantly, enhancement of T-cell activation.

  4. Interstitial photodynamic therapy of canine prostate with meso-tetra-(m-hydroxyphenyl) chlorin and 5-aminolevulinic acid: a preliminary study

    NASA Astrophysics Data System (ADS)

    Chang, Shi-Chung; Buonaccorsi, Giovanni A.; MacRobert, Alexander J.; Bown, Stephen G.

    1996-01-01

    Photodynamic therapy (PDT) is proved to have potential for managing various malignancies. We investigated tissue biodistribution and photodynamic effects on a canine model in vivo using second generation photosensitizers, meso-tetra(m-hydroxyphenyl)chlorin (mTHPC) and 5-aminolaevulinic acid (ALA) to evaluate the feasibility and possible future application of PDT on the prostate. Using fluorescence microscopy, the optimal sensitization time of the prostate was between 24 - 72 hours with mTHPC and, 3 hours with ALA. After optimum time of sensitization, prostates of mature beagle were treated with laser at various sites by placing fiber interstitially under the guidance of transrectal ultrasound. The light dose for each treatment site was 100 J (100 mW for 1,000 seconds at the wavelength of 650 and 630 nm, respectively). With mTHPC, single laser fiber was able to induce organ confined PDT lesion as large as 20 by 18 by 18 mm in size. However, the PDT lesion with ALA was negligible 3 days after treatment. Physical distress manifested as urinary retention, poor appetite and body weigh loss, was more prominent with increasing number of treatment sites as a result of extensive prostatic swelling and urethral damages. However, these problems usually alleviated spontaneously 7 to 10 days after PDT. The characteristic histological changes were hemorrhagic necrosis and glandular destruction with preservation of interlobular collagen fibers. Urethral damage seen at the early stage healed by regeneration of urothelium in 4 weeks. We conclude that interstitial PDT with mTHPC is technically possible to produce extensive glandular necrosis in the normal prostate which heals safely and does not change the prostatic architecture. ALA, although it seems promising for bladder tumors, is much less effective than mTHPC on the prostate. With mTHPC, it might have the potential for treating prostate cancers localized in the periphery of the gland.

  5. In vitro study of cell death with 5-aminolevulinic acid based photodynamic therapy to improve the efficiency of cancer treatment

    NASA Astrophysics Data System (ADS)

    Firdous, S.; Nawaz, M.; Ikram, M.; Ahmed, M.

    2012-03-01

    Photodynamic therapy (PDT) is a kind of photochemo therapeutic treatment that exerts its effect mainly through the induction of cell death. Distinct types of cell death may be elicited by different PDT regimes. In this study, efforts are underway to optimize PDT protocols for improved efficacy and combination of all three PDT mechanisms involved in the different human carcinomas cell narcosis. Our in vitro cell culture experiments with 5-aminolevulanic acid (ALA) a clinically approved photiosensitizer (PS) and 635 nm laser light have yielded promising results, as follow: (1) (human cervical cancer (HeLa) cell line incubated, for 18 h, with 30 μg/ml of 5-ALA, treated with laser light dose of 50 J/cm2 can produce 85% of cell killing (2) human larynx carcinoma (Hep2c) cell line incubated, for 7 h, with 55 μg/ml of 5-ALA, treated with laser light dose of 85 J/cm2 can produce 75% of cell killing (3) human liver cancer (HepG2) cell line incubated, for 22-48 h, with 262 μg/ml of 5-ALA, treated with laser light dose of 120 J/cm2 can produce 95% of cell killing (4) human muscle cancer (RD) cell line incubated, for 47 h, with 250 μg/ml of 5-ALA, treated with laser light dose of 80 J/cm2 can produce 76% of cell killing (5) Human embryonic kidney (HEK293T) cell line incu-bated, for 18 h, with 400 μg/ml of 5-ALA, treated with laser light dose of 40 J/cm2 can produce 82% of cell killing confirming the efficacy of photodynamic therapy.

  6. Photodynamic therapy (PDT) and photodiagnosis (PD) using endogenous photosensitization induced by 5-aminolevulinic acid (ALA): current clinical and development status

    NASA Astrophysics Data System (ADS)

    Marcus, Stuart L.; Sobel, Russel S.; Golub, Allyn L.; Carroll, Ronald L.; Lundahl, Scott L.; Shulman, D. Geoffrey

    1996-04-01

    Exogenous provision of ALA to many tissues results in the accumulation of sufficient quantities of the endogenous photosensitizer protoporphyrin IX, (PpIX), to produce a photodynamic effect. Therefore, ALA may be considered the only current PDT agent in clinical development which is a biochemical precursor of a photosensitizer. Topical ALA application, followed by exposure to activating light (ALA PDT), has been reported effective for the treatment of a variety of dermatologic diseases including cutaneous T-cell lymphoma, superficial basal cell carcinoma, Bowen's disease, and actinic (solar) keratoses, and is also being examined for treatment of acne and hirsutism. PpIX induced by ALA application also may serve as a fluorescence detection marker for photodiagnosis (PD) of malignant and pre- malignant conditions of the urinary bladder and other organs. Local internal application of ALA has also been used for selective endometrial ablation in animal model systems and is beginning to be examined in human clinical studies. Systemic, oral administration of ALA has been used for ALA PDT of superficial head and neck cancer, various gastrointestinal cancers, and the condition known as Barrett's esophagus. This brief paper reviews the current clinical and development status of ALA PDT.

  7. Low-Dose Topical 5-Aminolevulinic Acid Photodynamic Therapy in the Treatment of Different Severity of Acne Vulgaris.

    PubMed

    Tao, Shi-Qin; Li, Fei; Cao, Lei; Xia, Ru-Shan; Fan, Hua; Fan, Ying; Sun, Hui; Jing, Cheng; Yang, Li-Jia

    2015-12-01

    The objective of this article is to investigate the effectiveness and safety of photodynamic therapy (PDT) with 3.6 % topical aminolevulinic acid (ALA) and a short incubation time with red light in moderate to severe acne. One hundred and thirty-six patients with moderate to severe acne were treated with 3.6 % topical ALA-PDT for three sessions with an interval of 2 weeks. Patients were evaluated for efficacy and safety on week 2, 4, 6, 8, and 12 after the initial treatment. Most patients showed apparent clearance of acne lesions at the treated site after three sessions. The effective treatment rates were increased after the multiple therapies. The clinical outcomes are the best at 4 weeks after the final treatment. The total effectiveness rate and cure rate of the low-dose ALA-PDT procedure is 92.65 and 47.06 %, respectively. Thirty-one patients and nineteen patients showed apparent exacerbation of acne lesions before the 2nd and 3rd treatment, respectively, but all of them showed good or excellent improvement after a three-course treatment. A few patients showed mild relapse including papules and comedos at 8 weeks after the final treatment. No significant differences are found in the effects of different acne severity and different genders. Adverse reactions are mild and transient. A 3.6 % topical ALA-PDT with a short time incubation with red light is a simple and an effective treatment option for moderate to severe acne with mild side effects in Chinese people.

  8. Comparative Study of Photodynamic Therapy with Topical Methyl Aminolevulinate versus 5-Aminolevulinic Acid for Facial Actinic Keratosis with Long-Term Follow-Up

    PubMed Central

    Ko, Dong-Yeob; Kim, Ki-Ho

    2014-01-01

    Background Few studies have compared the efficacy, cosmetic outcomes, and adverse events between 5-aminolevulinic acid photodynamic therapy (ALA-PDT) and methyl aminolevulinate-PDT (MAL-PDT) for actinic keratoses (AKs) in Asian ethnic populations with dark-skin. Objective We retrospectively compared the long-term efficacy, recurrence rates, cosmetic outcomes, and safety of ALA-PDT versus MAL-PDT for facial AKs in Koreans. Methods A total of 222 facial AKs in 58 patients were included in this study. A total of 153 lesions (29 patients) were treated with 5-ALA, and 69 lesions (29 patients) with MAL. ALA and MAL creams were applied for 6 hours and 3 hours, respectively; the lesions were then illuminated with a halogen lamp at 150 J/cm2 for ALA-PDT and a diode lamp at 37 J/cm2 for MAL-PDT. Results The complete response rates of ALA-PDT and MAL-PDT were 56.9% and 50.7%, respectively, with no significant difference at 12 months after treatment. No significant difference in recurrence rates was observed between the 2 PDT modalities at either 6 or 12 months after treatment. There was no significant difference in the cosmetic outcomes between the 2 treatment modalities at 12 months after PDT. However, ALA-PDT caused significantly more painful than MAL-PDT (p=0.005). The adverse events were mild to moderate, transient, and self-limiting for both modalities. Conclusion MAL-PDT was similar to ALA-PDT in terms of long-term efficacy, recurrence rates, cosmetic outcomes, and adverse events; however, it was a significantly less painful procedure than ALA-PDT in our study. PMID:24966631

  9. Homology modeling of human γ-butyric acid transporters and the binding of pro-drugs 5-aminolevulinic acid and methyl aminolevulinic acid used in photodynamic therapy.

    PubMed

    Baglo, Yan; Gabrielsen, Mari; Sylte, Ingebrigt; Gederaas, Odrun A

    2013-01-01

    Photodynamic therapy (PDT) is a safe and effective method currently used in the treatment of skin cancer. In ALA-based PDT, 5-aminolevulinic acid (ALA), or ALA esters, are used as pro-drugs to induce the formation of the potent photosensitizer protoporphyrin IX (PpIX). Activation of PpIX by light causes the formation of reactive oxygen species (ROS) and toxic responses. Studies have indicated that ALA and its methyl ester (MAL) are taken up into the cells via γ-butyric acid (GABA) transporters (GATs). Uptake via GATs into peripheral sensory nerve endings may also account for one of the few adverse side effects of ALA-based PDT, namely pain. In the present study, homology models of the four human GAT subtypes were constructed using three x-ray crystal structures of the homologous leucine transporter (LeuT) as templates. Binding of the native substrate GABA and the possible substrates ALA and MAL was investigated by molecular docking of the ligands into the central putative substrate binding sites in the outward-occluded GAT models. Electrostatic potentials (ESPs) of the putative substrate translocation pathway of each subtype were calculated using the outward-open and inward-open homology models. Our results suggested that ALA is a substrate of all four GATs and that MAL is a substrate of GAT-2, GAT-3 and BGT-1. The ESP calculations indicated that differences likely exist in the entry pathway of the transporters (i.e. in outward-open conformations). Such differences may be exploited for development of inhibitors that selectively target specific GAT subtypes and the homology models may hence provide tools for design of therapeutic inhibitors that can be used to reduce ALA-induced pain. PMID:23762315

  10. Clinical efficacy of 5-aminolevulinic acid photodynamic therapy in the treatment of moderate to severe facial acne vulgaris

    PubMed Central

    CHEN, XIANGQI; SONG, HONGTAO; CHEN, SHENGPING; ZHANG, JING; NIU, GAOXIANG; LIU, XIANGNONG

    2015-01-01

    Acne vulgaris is considered as a therapeutic challenge in terms of managing ongoing symptoms and preventing scar formation. Although there are many available treatments for alleviating acne, therapies for resistant or moderate-to-severe forms have been limited to systemic agents that are accompanied by potentially severe side-effects. While, aminolevulinic acid (ALA) photodynamic therapy (PDT) has increasingly been used as a simple and safe therapeutic option of acne vulgaris, the clinical efficacy requires confirmation in further studies. The aim of this study was to investigate the efficacy and safety of 5-ALA-PDT in the treatment of moderate-to-severe facial acne vulgaris. A total of 50 patients with moderate-to-severe facial acne were enrolled in the study and randomly divided equally into a therapy group and a control group. In the therapy group, the patients were treated with 5% 5-ALA for 1.5 h, followed by three 20-min doses of infrared radiation once a week; in the control group, the patients were treated with three 20 min doses of infrared radiation without 5-ALA once a week. Both treatments lasted for 3 weeks. The clinical efficacy was determined by evaluating acne lesion counts at weeks 0, 2, 4 and 6. Total efficacy rate (TER) was the primary endpoint of the study, and was defined as the proportion of the patients whose treatment effectiveness evaluation was cured (≥90% of skin lesions improved) and excellent (60–89% improvement). Adverse effects were recorded throughout the study. The study was completed by 24 patients in the therapy group and 23 patients in the control group. The numbers of acne lesions significantly decreased. The TER of the therapy group was significantly higher than that of the control group at weeks 4 and 6. Adverse effects were observed in 12 patients of the therapy group and 2 patients of the control group. In the therapy group the most common adverse effect was a burning sensation (n=7), followed by transient

  11. 5-Aminolevulinic Acid-Mediated Sonodynamic Therapy Promotes Phenotypic Switching from Dedifferentiated to Differentiated Phenotype via Reactive Oxygen Species and p38 Mitogen-Activated Protein Kinase in Vascular Smooth Muscle Cells.

    PubMed

    Dan, Juhua; Sun, Xin; Li, Wanlu; Zhang, Yun; Li, Xuesong; Xu, Haobo; Li, Zhitao; Tian, Zhen; Guo, Shuyuan; Yao, Jianting; Gao, Weidong; Tian, Ye

    2015-06-01

    Sonodynamic therapy (SDT) has been found to inhibit in-stent restenosis in animal models. However, the mechanism is not fully elucidated. Here, we investigated the effects of 5-aminolevulinic acid (ALA)-mediated SDT (ALA-SDT) on vascular smooth muscle cells (VSMCs), a cause of restenosis, with a focus on SDT-induced phenotypic switching. Serum-induced dedifferentiated VSMCs were cultured with ALA (1 mm, 24 h) and exposed to ultrasound (0.8 W/cm(2)) for 5 min. Results indicated that ALA-SDT inhibited the migration and proliferation of VSMCs and enhanced the expression of differentiated phenotypic markers in VSMCs. Additionally, ALA-SDT increased intracellular reactive oxygen species accumulation and phosphorylated p38 mitogen-activated protein kinase in VSMCs. Inhibition of reactive oxygen species elevation or p38 mitogen-activated protein kinase activity abolished the expression of smooth muscle 22α (SM22α) in VSMCs induced by ALA-SDT. Taken together, these results suggest that ALA-SDT promotes transformation of the VSMC phenotype from the dedifferentiated to differentiated status via reactive oxygen species and activated p38 mitogen-activated protein kinase.

  12. In vitro study of 5-aminolevulinic acid-based photodynamic therapy for apoptosis in human cervical HeLa cell line

    NASA Astrophysics Data System (ADS)

    Atif, M.; Firdous, S.; Khurshid, A.; Noreen, L.; Zaidi, S. S. Z.; Ikram, M.

    2009-12-01

    5-aminolevulanic acid (ALA), belonging among the promising second generation of sensitizers, was evaluated as an inducer of photodamage on HeLa (human cervical adenocarcinoma) cell line. A diode laser (635 nm) was used as a source for initiation of the photodynamic effect. We studied the influence of different incubation times, various concentrations of sensitizer, different irradiation doses and various combinations of sensitizer and light doses on the photodamage of HeLa cells. Viability of cells was determined by means of neutral red assay. The quantitative cellular uptake of ALA sensitizer was done by spectrophotometric measurements. No prominent cytotoxic or phototoxic effects on HeLa were observed due to sensitizer or light doses when studied independently of each other. However phototoxicity evoked by laser irradiated sensitizer was detected in HeLa cell line.

  13. Photodynamic Therapy (PDT) using intratumoral injection of the 5- aminolevulinic acid (5-ALA) for the treatment of eye cancer in cattle

    NASA Astrophysics Data System (ADS)

    Hage, Raduan; Mancilha, Geraldo; Zângaro, Renato A.; Munin, Egberto; Plapler, Hélio

    2007-02-01

    A six-year old Holstein cow with an eye cancer (ocular squamous cell carcinoma) involving the third eyelid and conjunctiva was submitted to photodynamic therapy using intratumoral 20% aminolevulinic acid (5-ALA - Aldrich Chemical Company, Milwaukee, USA) and a light emitting diode (LED - VET LED - MMOptics (R)) with wavelength between 600 and 700 nm, 2 cm diameter circular light beam, power of 150 mW, light dose of 50 J/cm2 as a source of irradiation. Fifteen days after the experimental procedure we observed about 50% tumor reduction and complete remission after 3 months. Relapse was not observed up to 12 months after the treatment. Although the study only includes one animal not allowing definite conclusions, it indicates that PDT represents a safe and technically feasible approach in the treatment of eye cancer in cattle.

  14. Photodynamic therapy of human skin tumors using topical application of 5-aminolevulinic acid, dimethylsulfoxide (DMSO), and edetic acid disodium salt (EDTA)

    NASA Astrophysics Data System (ADS)

    Orenstein, Arie; Kostenich, Gennady; Tsur, H.; Roitman, Leonid; Ehrenberg, Benjamin; Malik, Zvi

    1995-01-01

    The results of photodynamic therapy (PDT) in 48 patients bearing basal cell carcinoma (BCC) and 7 patients with squamous cell carcinoma (SCC) of the skin are described. Five- aminolevulinic acid (5-ALA) was applied topically in two formulations. The first formulation contained 20% of 5-ALA in a base cream, and the second formulation (5-ALA composite cream), contained an additional 2% of dimethylsulfoxide (DMSO) and 2% of edetic acid disodium salt (EDTA). The creams were left on the skin for 2 - 5 hours. Production of protoporphyrin (PP) was measured in situ by a laser-induced fluorescence (LIF) method. The results of fluorescence measurement clearly indicate that PP accumulation in tumors induced by the 5-ALA composite cream was markedly higher than that induced by the 5-ALA cream. The tumors were light-irradiated (600 - 720 nm) after 4 - 5 hours of cream applications, using the light delivery system Versa-Light by a light dose of 100 J/cm2. The clinically superficial BCC tumors were highly responsive to PDT; the overall result in BCC patients was an 85.4% complete response. Histological examination showed an initial edematous reaction, followed by necrosis and complete disappearance of the tumor. The superficial SCC tumors showed a 100% complete response after PDT. The ulcerated nodular SCC showed partial responses.

  15. Photofrin and 5-aminolevulinic acid permeation through oral mucosa in vitro

    NASA Astrophysics Data System (ADS)

    Flock, Stephen T.; Alleman, Anthony; Lehman, Paul; Blevins, Steve; Stone, Angie; Fink, Louis; Dinehart, Scott; Stern, Scott J.

    1994-07-01

    Photofrin and 5-aminolevulinic acid are photosensitizers that show promise in the photodynamic treatment of cancer, port-wine stains, atherosclerosis and viral lesions. Photofrin is a mixture of porphyrins which, upon the absorption of light, become temporarily cytotoxic. One side-effect associated with the use of Photofrin is long-term cutaneous photosensitivity. It is possible that topical application of this photosensitizing dye will ameliorate such a side-effect. Another way to avoid the cutaneous photosensitivity in photodynamic therapy is to use 5- aminolevulinic acid, which is a porphyrin precursor that causes an increase in the synthesis and concentration of the photosensitizer protoporphyrin IX. 5-aminolevulinic acid is usually applied topically, and so minimizes cutaneous photosensitivity while maximizing the local protoporphyrin concentration. There are a host of disorders in oral mucosa that are potentially treatable by photodynamic therapy. However, since stratum corneum presents an impermeable barrier to many pharmaceuticals, it is not clear that topical application of the photosensitizer will result in a clinically relevant tissue concentration. We have therefore studied the permeation behavior of Photofrin and 5-aminolevulinic acid by applying them to the surface of ex vivo oral mucosa tissue positioned by a Franz diffusion cell. In order to increase the permeability of the photosensitizer across the stratum corneum, we studied the effects of four different drug carriers: phosphate buffered saline, dimethylsulfoxide, ethanol and Azone with isopropyl alcohol.

  16. 5-Aminolaevulinic acid-mediated photodynamic therapy in multidrug resistant leukemia cells.

    PubMed

    Li, W; Zhang, W J; Ohnishi, K; Yamada, I; Ohno, R; Hashimoto, K

    2001-07-01

    To verify if photodynamic therapy (PDT) could overcome multidrug resistance (MDR) when it it applied to eradicate minimal residual disease in patients with leukemia, we investigated the fluorescence kinetics of 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) and the effect of subsequent photodynamic therapy on MDR leukemia cells, which express P-glycoprotein (P-gp), as well as on their parent cells. Evaluation of PpIX accumulation by flow cytometry showed that PpIX accumulated at higher levels in mdr-1 gene-transduced MDR cells (NB4/MDR) and at lower levels in doxorubicin-induced MDR cells (NOMO-1/ADR) than in their parent cells. A P-gp inhibitor could not increase PpIX accumulation. Measurement of extracellular PpIX concentration by fluorescence spectrometry showed that P-gp did not mediate the fluorescence kinetics of ALA-induced PpIX production. Assessment of ferrochelatase activity using high-performance liquid chromatography indicated that PpIX accumulation in drug-induced MDR cells was probably regulated by this enzyme. Assessment of phototoxicity of PDT using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that PDT was effective in NB4, NB4/MDR, NOMO-1 and NOMO-1/ADR cells, which accumulated high levels of PpIX, but not effective in K562 and K562/ADR cell lines, which accumulated relatively low levels of PpIX. These findings demonstrate that P-gp does not mediate the ALA-fluorescence kinetics, and multidrug resistant leukemia cells do not have cross-resistance to ALA-PDT. PMID:11470562

  17. Characterization of 5-aminolevulinate synthase from Agrobacterium radiobacter, screening new inhibitors for 5-aminolevulinate dehydratase from Escherichia coli and their potential use for high 5-aminolevulinate production.

    PubMed

    Lin, Jianping; Fu, Weiqi; Cen, Peilin

    2009-04-01

    The hemA gene encoding 5-aminolevulinate synthase (ALAS) from Agrobacterium radiobacter zju-0121 showed 92.6% homology with that from A. radiobacter ATCC4718 and contained several rare codons. To enhance the expression of this gene, Escherichia coli Rosetta(DE3), which is a rare codon optimizer strain, was used as the host to construct an efficient recombinant strain. And the encoded protein was over-expressed as fusion protein and was purified by affinity purification on Ni-NTA agarose and by gel filtration chromatography on Sephadex G-25 Medium resin. The recombinant protein was partly characterized, and D-glucose, D-fructose, D-xylose, D-mannose, L-arabinose, D-galactose, lactose, sucrose and maltose were detected to have no distinct inhibition on this recombinant ALAS. Meanwhile, 20mM D-glucose or D-xylose inhibited about 20% activity of ALA dehydratase (ALAD) from Escherichia coli Rosetta(DE3). Combining D-xylose as a new inhibitor for ALAD with D-glucose in fed-batch culture and based on the optimal culture system using Rosetta(DE3)/pET28a-hemA, the yield of ALA achieved was 7.3g/l (56 mM) under the appropriate conditions in the fermenter.

  18. Physicochemical characterisation of a novel thermogelling formulation for percutaneous penetration of 5-aminolevulinic acid.

    PubMed

    Grüning, Nadja; Müller-Goymann, Christel Charlotte

    2008-06-01

    The present contribution was dedicated to the development and characterisation of a semisolid formulation of 5-aminolevulinic acid (5-ALA), appropriate for the diagnosis and treatment of actinic keratosis in photodynamic therapy. To achieve sufficiently high concentrations of the polar substance within the living epithelium after topical application, the semisolid base was enriched with penetration enhancers. A semisolid liquid crystalline system for drug delivering was the formulation of choice. It was composed of isopropyl alcohol, dimethyl isosorbide, medium chain triglycerides, water, and Pluronic F 127 as a polyoxyethylene-polyoxypropylene surface-active block copolymer. Rheometrical investigations were performed in the oscillatory mode and showed a thermo reversible gelification behaviour of the formulation, which therefore was denoted Thermogel. Permeation studies through human stratum corneum revealed higher permeation coefficients for 5-ALA from the Thermogel than from different German Pharmacopoeia creams. For example a 7.5-fold increase in comparison with Basiscreme DAC, and a 19.5-fold increase compared to water containing hydrophilic ointment. With respect to Dolgit(R) Mikrogel, the permeation coefficient from the Thermogel was 6.4-fold higher. These results were in accordance with those of differential scanning calorimetry measurements. Thermogel disclosed the strongest interactions with stratum corneum lipids.

  19. A Formulation Study of 5-Aminolevulinic Encapsulated in DPPC Liposomes in Melanoma Treatment

    PubMed Central

    Lin, Ming-Wei; Huang, Yaw-Bin; Chen, Chun-Lin; Wu, Pao-Chu; Chou, Chien-Ying; Wu, Ping-Ching; Hung, Shih-Ya

    2016-01-01

    Photodynamic therapy (PDT) is a widely used technique for epithelial skin cancer treatment. 5-aminolevulinic acid (5-ALA) is a drug currently used for PDT and is a hydrophilic molecule at its physiological pH, and this limits its capacity to cross the stratum corneum of skin. Since skin penetration is a key factor in the efficacy of topical 5-ALA-mediated PDT, numerous strategies have been proposed to improve skin penetration. Yet this problem is still ongoing. The results of a previous study showed a low rate of 5-ALA encapsulated in liposomes (5.7%) that were 400 nm in size. In the present study, we used 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes as vehicles and tested their delivery efficacy of 5-ALA-medicated PDT both in vitro and in vivo. Our data shows that 5-ALA encapsulated in 0.1 or 0.5% DPPC liposomes (5-ALA/DPPC) had a better encapsulated rate (15~16%) and were smaller in size (84~89 nm). We found the 5-ALA/DPPC formulation reduced cell viability, mitochondria membrane potential, and enhanced intracellular ROS accumulation as compared to 5-ALA alone in melanoma cells. Furthermore, the 5-ALA/DPPC formulation also had better skin penetration ability as compared to the 5-ALA in our ex vivo data by assaying 5-ALA converted into protoporphyrin IX (PpIX) in the skin of the mice that were experimented on. In melanoma xenograft models, 5-ALA/DPPC enhanced PpIX accumulation only in tumor tissue but not normal skin. In conclusion, we found DPPC liposomes to be good carriers for 5-ALA delivery and believe that they may prove useful in 5-ALA-mediated PDT in the future. PMID:27429584

  20. Therapeutic and Aesthetic Uses of Photodynamic Therapy Part five of a five-part series

    PubMed Central

    2009-01-01

    The use of 5-aminolevulinic acid–photodynamic therapy in clinical practice is an individual determination based on experiences learned from clinicians and from personal experience. This manuscript reviews how one clinician approaches patients interested in having photodynamic therapy. It covers all practical aspects of the treatment process and reviews how photodynamic therapy can be utilized in your clinical practice. PMID:20967186

  1. Quantification of topically delivered 5-aminolevulinic acid by lontophoresis across ex vivo human stratum corneum.

    PubMed

    Boddé, Harry E; Roemelé, Peter E H; Star, Willem M

    2002-04-01

    Iontophoretic transport of the prodrug 5-aminolevulinic acid (ALA), which is used for photodynamic therapy (PDT), across human stratum corneum (SC) was studied quantitatively in vitro. The experiments were carried out in a three-compartment iontophoresis cell consisting of two electrode chambers equipped with Ag-AgCl electrodes, each separated from a central acceptor chamber by a sheet of SC, supported by a dialysis membrane, to mimic the side-by-side configuration normally used in vivo. Acceptor fluid samples were collected every hour for a period of 30 h in a fraction collector and analyzed by high-performance liquid chromatography-fluorometry after derivatization of the ALA. The iontophoretic ALA flux was studied as a function of the applied current density and the ALA concentration in the donor solution (1, 2.5 or 10% ALA). Depending on the ALA concentration in the donor cell, iontophoresis enhances the flux from close to the detection limit of 0.23 nmol cm(-2) h(-1) at zero current density (passive diffusion) to several hundred or thousand nanomoles per square centimeter per hour at current densities ranging from 100 to 1000 microA cm(-2). For example, interpolating our data we find that with an ALA concentration of 2% in the donor chamber, a current density of 0.255 mA cm(-2) transports 0.065 micromol cm(-2) ALA across the SC in 10 min (conditions of Rhodes et al. (1997), J. Invest. Dermatol. 108, 87-91). For passive diffusion we find that a 5 h topical application of 20% ALA results in the transport of 0.05 micromol cm(-2). Thus, the amount of ALA that passively diffuses through the SC in several hours, leading to therapeutic levels of protoporphyrin IX (PpIX) in the epidermis, can be delivered by iontophoresis in 10 min or less. However, because the formation of sufficient PpIX also requires several hours and also because the SC overlying skin lesions such as basal cell carcinoma (BCC) is not intact, the clinical benefit of topical ALA delivery by

  2. Inhibitory Effect of Gabaculine on 5-Aminolevulinate Dehydratase Activity in Radish Seedlings 1

    PubMed Central

    Tchuinmogne, Simo J.; Huault, Claude; Aoues, Abdelkader; Balangé, Alain P.

    1989-01-01

    We have compared the activity of 5-aminolevulinate dehydratase (5-ALAD) with the amount of protein detected by specific antibodies in rocket immunoelectrophoresis. Parallel kinetic evolutions of enzymic activity and amount of antigen were observed in radish (Raphanus sativus L.) cotyledons, both in complete darkness or under standard far red light involving phytochrome. However, the treatment of seedlings with gabaculine leads to an important decrease in enzymic activity, while the specific protein content is maintained. This inhibition is not overcome by the addition of glutamic acid, but by 5-aminolevulinic acid which points to a specific control of 5-ALAD activity by its substrate. As there is no discrepancy between the enzymic activity and the amount of antigen during the time course development of seedlings, this could confirm a coordinate cellular control between 5-aminolevulinic acid formation and 5-ALAD protein synthesis, both being amplified by the action of phytochrome. PMID:16666925

  3. 5-aminolevulinic acid for quantitative seek-and-treat of high-grade dysplasia in Barrett's esophagus cellular models

    NASA Astrophysics Data System (ADS)

    Yeh, Shu-Chi Allison; Ling, Celine S. N.; Andrews, David W.; Patterson, Michael S.; Diamond, Kevin R.; Hayward, Joseph E.; Armstrong, David; Fang, Qiyin

    2015-02-01

    High-grade dysplasia (HGD) in Barrett's esophagus (BE) poses increased risk for developing esophageal adenocarcinoma. To date, early detection and treatment of HGD regions are still challenging due to the sampling error from tissue biopsy and relocation error during the treatment after histopathological analysis. In this study, CP-A (metaplasia) and CP-B (HGD) cell lines were used to investigate the "seek-and-treat" potential using 5-aminolevulinic acid-induced protoporphyrin IX (PpIX). The photodynamic therapy photosensitizer then provides both a phototoxic effect and additional image contrast for automatic detection and real-time laser treatment. Complementary to our studies on automatic classification, this work focused on characterizing subcellular irradiation and the potential phototoxicity on both metaplasia and HGD. The treatment results showed that the HGD cells are less viable than metaplastic cells due to more PpIX production at earlier times. Also, due to mitochondrial localization of PpIX, a better killing effect was achieved by involving mitochondria or whole cells compared with just nucleus irradiation in the detected region. With the additional toxicity given by PpIX and potential morphological/textural differences for pattern recognition, this cellular platform serves as a platform to further investigate real-time "seek-and-treat" strategies in three-dimensional models for improving early detection and treatment of BE.

  4. A New Strategy for Production of 5-Aminolevulinic Acid in Recombinant Corynebacterium glutamicum with High Yield

    PubMed Central

    Yang, Peng; Liu, Wenjing; Cheng, Xuelian; Wang, Jing; Qi, Qingsheng

    2016-01-01

    ABSTRACT 5-Aminolevulinic acid (ALA), a nonprotein amino acid involved in tetrapyrrole synthesis, has been widely applied in agriculture, medicine, and food production. Many engineered metabolic pathways have been constructed; however, the production yields are still low. In this study, several 5-aminolevulinic acid synthases (ALASs) from different sources were evaluated and compared with respect to their ALA production capacities in an engineered Corynebacterium glutamicum CgS1 strain that can accumulate succinyl-coenzyme A (CoA). A codon-optimized ALAS from Rhodobacter capsulatus SB1003 displayed the best potential. Recombinant strain CgS1/pEC-SB produced 7.6 g/liter ALA using a mineral salt medium in a fed-batch fermentation mode. Employing two-stage fermentation, 12.46 g/liter ALA was produced within 17 h, with a productivity of 0.73 g/liter/h, in recombinant C. glutamicum. Through overexpression of the heterologous nonspecific ALA exporter RhtA from Escherichia coli, the titer was further increased to 14.7 g/liter. This indicated that strain CgS1/pEC-SB-rhtA holds attractive industrial application potential for the future. IMPORTANCE In this study, a two-stage fermentation strategy was used for production of the value-added nonprotein amino acid 5-aminolevulinic acid from glucose and glycine in a generally recognized as safe (GRAS) host, Corynebacterium glutamicum. The ALA titer represented the highest in the literature, to our knowledge. This high production capacity, combined with the potential easy downstream processes, made the recombinant strain an attractive candidate for industrial use in the future. PMID:26921424

  5. Evidence that isolated developing chloroplasts are capable of synthesizing chlorophyll b from 5-aminolevulinic acid

    SciTech Connect

    Huang, Laiqiang; Hoffman, N.E. )

    1990-09-01

    Developing chloroplasts isolated from cucumber (Cucumis sativus L. var Beit Alpha) cotyledons are capable of incorporating ({sup 14}C)5-aminolevulinic acid into chlorophyll (Chl) b and Chl a when incubated under photosynthetic illumination. Thin layer chromatography and high pressure liquid chromatography were employed to analyze the pigments. The specific radioactivity in Chl a was over three times higher than that found in Chl b. Both Chl a and b synthesizing activities in organello decayed rapidly at approximately the same rate. We conclude that concomitant synthesis of Chl a/b-binding apoprotein is not required for Chl b synthesis.

  6. The use of photodynamic therapy for treatment of acne vulgaris.

    PubMed

    Nestor, Mark S

    2007-01-01

    Current topical and most oral therapies for acne vulgaris have limited efficacy, especially in moderate to severe cases. Photodynamic therapy with 5-aminolevulinic acid and recently methyl aminolevulinate has been shown to be a safe and effective modality for the treatment of acne vulgaris. Consensus guidelines suggest that 30 to 60 minutes is sufficient 5-aminolevulinic acid contact time before photoactivation with blue light, red light, yellow light, broadband light, halogen, or pulsed dye laser devices. An average of three treatment can yield significant long-term improvement. PMID:17126741

  7. Production of 5-aminolevulinic acid by cell free multi-enzyme catalysis.

    PubMed

    Meng, Qinglong; Zhang, Yanfei; Ju, Xiaozhi; Ma, Chunling; Ma, Hongwu; Chen, Jiuzhou; Zheng, Ping; Sun, Jibin; Zhu, Jun; Ma, Yanhe; Zhao, Xueming; Chen, Tao

    2016-05-20

    5-Aminolevulinic acid (ALA) is the precursor for the biosynthesis of tetrapyrroles and has broad agricultural and medical applications. Currently ALA is mainly produced by chemical synthesis and microbial fermentation. Cell free multi-enzyme catalysis is a promising method for producing high value chemicals. Here we reported our work on developing a cell free process for ALA production using thermostable enzymes. Cheap substrates (succinate and glycine) were used for ALA synthesis by two enzymes: 5-aminolevulinic acid synthase (ALAS) from Laceyella sacchari (LS-ALAS) and succinyl-CoA synthase (Suc) from Escherichia coli. ATP was regenerated by polyphosphate kinase (Ppk) using polyphosphate as the substrate. Succinate was added into the reaction system in a fed-batch mode to avoid its inhibition effect on Suc. After reaction for 160min, ALA concentration was increased to 5.4mM. This is the first reported work on developing the cell free process for ALA production. Through further process and enzyme optimization the cell free process could be an effective and economic way for ALA production.

  8. Clinical utility of 5-aminolevulinic acid HCl to better visualize and more completely remove gliomas

    PubMed Central

    Halani, Sameer H; Adamson, D Cory

    2016-01-01

    Surgical resection is typically the first line of treatment for gliomas. However, the neurosurgeon faces a major challenge in achieving maximal resection in high-grade gliomas as these infiltrative tumors make it difficult to discern tumor margins from normal brain with conventional white-light microscopy alone. To aid in resection of these infiltrative tumors, fluorescence-guided surgery has gained much popularity in intraoperative visualization of malignant gliomas, with 5-aminolevulinic acid (5-ALA) leading the way. First introduced in an article in Neurosurgery, 5-ALA has since become a safe, effective, and inexpensive method to visualize and improve resection of gliomas. This has undoubtedly led to improvements in the clinical course of patients as demonstrated by the increased overall and progression-free survival in patients with such devastating disease. This literature review aims to discuss the major studies and trials demonstrating the clinical utility of 5-ALA and its ability to aid in complete resection of malignant gliomas.

  9. 5-aminolevulinic acid guidance during awake craniotomy to maximise extent of safe resection of glioblastoma multiforme.

    PubMed

    Corns, Robert; Mukherjee, Soumya; Johansen, Anja; Sivakumar, Gnanamurthy

    2015-01-01

    Overall survival for patients with glioblastoma multiforme (GBM) has been consistently shown to improve when the surgeon achieves a gross total resection of the tumour. It has also been demonstrated that surgical adjuncts such as 5-aminolevulinic acid (5-ALA) fluorescence--which delineates malignant tumour tissue--normal brain tissue margin seen using violet-blue excitation under an operating microscope--helps achieve this. We describe the case of a patient with recurrent left frontal GBM encroaching on Broca's area (eloquent brain). Gross total resection of the tumour was achieved by combining two techniques, awake resection to prevent damage to eloquent brain and 5-ALA fluorescence guidance to maximise the extent of tumour resection.This technique led to gross total resection of all T1-enhancing tumour with the avoidance of neurological deficit. The authors recommend this technique in patients when awake surgery can be tolerated and gross total resection is the aim of surgery. PMID:26177997

  10. Noninvasive fluorescence monitoring of protoporphyrin IX production and clinical outcomes in actinic keratoses following short-contact application of 5-aminolevulinate

    NASA Astrophysics Data System (ADS)

    Warren, Christine B.; Lohser, Sara; Wene, Lauren C.; Pogue, Brian W.; Bailin, Philip L.; Maytin, Edward V.

    2010-09-01

    Topical 5-aminolevulinic acid (ALA) is widely used in photodynamic therapy (PDT) of actinic keratoses (AK), a type of premalignant skin lesion. However, the optimal time between ALA application and exposure to light has not been carefully investigated. Our objective is to study the kinetics of protoporphyrin IX (PpIX) accumulation in AK after short contact ALA and relate this to erythemal responses. Using a noninvasive dosimeter, PpIX fluorescence measurements (5 replicates) were taken at 20-min intervals for 2 h following ALA application, in 63 AK in 20 patients. Data were analyzed for maximal fluorescent signal obtained, kinetic slope, and changes in erythema. Our results show that PpIX accumulation was linear over time, becoming statistically higher than background in 48% of all lesions by 20 min, 92% of lesions by 1 h, and 100% of lesions by 2 h. PpIX accumulation was roughly correlated with changes in lesional erythema post-PDT. We conclude that significant amounts of PpIX are produced in all AK lesions by 2 h. The linear kinetics of accumulation suggest that shorter ALA application times may be efficacious in many patients. Noninvasive fluorescence monitoring of PpIX may be useful to delineate areas of high PpIX accumulation within precancerous areas of the skin.

  11. Topical glycerol monooleate/propylene glycol formulations enhance 5-aminolevulinic acid in vitro skin delivery and in vivo protophorphyrin IX accumulation in hairless mouse skin.

    PubMed

    Steluti, Regilene; De Rosa, Fernanda Scarmato; Collett, John; Tedesco, Antônio Cláudio; Bentley, Maria Vitória Lopes Badra

    2005-08-01

    Photodynamic therapy (PDT), a potential therapy for cancer treatment, utilizes exogenously applied or endogenously formed photosensitizers, further activated by light in an appropriate wavelength and dose to induce cell death through free radical formation. 5-Aminolevulinic acid (5-ALA) is a pro-drug which can be converted to the effective photosensitizer, protoporphyrin IX (PpIX). However, the use of 5-ALA in PDT is limited by the low penetration capacity of this highly hydrophilic molecule into appropriate skin layers. In the present study, we propose to increase 5-ALA penetration by using formulations containing glycerol monooleate (GMO), an interesting and useful component of pharmaceutical formulations. Propylene glycol solutions containing different concentrations of GMO significantly increased the in vitro skin permeation/retention of 5-ALA in comparison to control solutions. In vivo studies also showed increased PpIX accumulation in mouse hairless skin, after the use of topical 5-ALA formulations containing GMO in a concentration-dependent manner. The results show that skin 5-ALA penetration and PpIX accumulation, important factors for the success of topical 5-ALA-PDT in skin cancer, are optimized by GMO/propylene glycol formulations.

  12. Regulation of the hemA gene during 5-aminolevulinic acid formation in Pseudomonas aeruginosa.

    PubMed Central

    Hungerer, C; Troup, B; Römling, U; Jahn, D

    1995-01-01

    The general tetrapyrrole precursor 5-aminolevulinic acid is formed in bacteria via two different biosynthetic pathways. Members of the alpha group of the proteobacteria use 5-aminolevulinic acid synthase for the condensation of succinyl-coenzyme A and glycine, while other bacteria utilize a two-step pathway from aminoacylated tRNA(Glu). The tRNA-dependent pathway, involving the enzymes glutamyl-tRNA reductase (encoded by hemA) and glutamate-1-semialdehyde-2,1-aminomutase (encoded by hemL), was demonstrated to be used by Pseudomonas aeruginosa, Pseudomonas putida, Pseudomonas stutzeri, Comamonas testosteroni, Azotobacter vinelandii, and Acinetobacter calcoaceticus. To study the regulation of the pathway, the glutamyl-tRNA reductase gene (hemA) from P. aeruginosa was cloned by complementation of an Escherichia coli hemA mutant. The hemA gene was mapped to the SpeI A fragment and the DpnIL fragment of the P. aeruginosa chromosome corresponding to min 24.1 to 26.8. The cloned hemA gene, coding for a protein of 423 amino acids with a calculated molecular mass of 46,234 Da, forms an operon with the gene for protein release factor 1 (prf1). This translational factor mediates the termination of the protein chain at the ribosome at amber and ochre codons. Since the cloned hemA gene did not possess one of the appropriate stop codons, an autoregulatory mechanism such as that postulated for the enterobacterial system was ruled out. Three open reading frames of unknown function transcribed in the opposite direction to the hemA gene were found. hemM/orf1 and orf2 were found to be homologous to open reading frames located in the 5' region of enterobacterial hemA genes. Utilization of both transcription start sites was changed in a P. aeruginosa mutant missing the oxygen regulator Anr (Fnr analog), indicating the involvement of the transcription factor in hemA expression. DNA sequences homologous to one half of an Anr binding site were detected at one of the determined

  13. Clinical utility of 5-aminolevulinic acid HCl to better visualize and more completely remove gliomas.

    PubMed

    Halani, Sameer H; Adamson, D Cory

    2016-01-01

    Surgical resection is typically the first line of treatment for gliomas. However, the neurosurgeon faces a major challenge in achieving maximal resection in high-grade gliomas as these infiltrative tumors make it difficult to discern tumor margins from normal brain with conventional white-light microscopy alone. To aid in resection of these infiltrative tumors, fluorescence-guided surgery has gained much popularity in intraoperative visualization of malignant gliomas, with 5-aminolevulinic acid (5-ALA) leading the way. First introduced in an article in Neurosurgery, 5-ALA has since become a safe, effective, and inexpensive method to visualize and improve resection of gliomas. This has undoubtedly led to improvements in the clinical course of patients as demonstrated by the increased overall and progression-free survival in patients with such devastating disease. This literature review aims to discuss the major studies and trials demonstrating the clinical utility of 5-ALA and its ability to aid in complete resection of malignant gliomas. PMID:27672334

  14. Physiological and Metabolic Effects of 5-Aminolevulinic Acid for Mitigating Salinity Stress in Creeping Bentgrass

    PubMed Central

    Yang, Zhimin; Chang, Zuoliang; Sun, Lihong; Yu, Jingjin; Huang, Bingru

    2014-01-01

    The objectives of this study were to determine whether foliar application of a chlorophyll precursor, 5-aminolevulinic acid (ALA), could mitigate salinity stress damages in perennial grass species by regulating photosynthetic activities, ion content, antioxidant metabolism, or metabolite accumulation. A salinity-sensitive perennial grass species, creeping bentgrass (Agrostis stolonifera), was irrigated daily with 200 mM NaCl for 28 d, which were foliar sprayed with water or ALA (0.5 mg L−1) weekly during the experiment in growth chamber. Foliar application of ALA was effective in mitigating physiological damage resulting from salinity stress, as manifested by increased turf quality, shoot growth rate, leaf relative water content, chlorophyll content, net photosynthetic rate, stomatal conductance and transpiration rate. Foliar application of ALA also alleviated membrane damages, as shown by lower membrane electrolyte leakage and lipid peroxidation, which was associated with increases in the activities of antioxidant enzymes. Leaf content of Na+ was reduced and the ratio of K+/Na+ was increased with ALA application under salinity stress. The positive effects of ALA for salinity tolerance were also associated with the accumulation of organic acids (α-ketoglutaric acid, succinic acid, and malic acid), amino acids (alanine, 5-oxoproline, aspartic acid, and γ -aminobutyric acid), and sugars (glucose, fructose, galactose, lyxose, allose, xylose, sucrose, and maltose). ALA-mitigation of physiological damages by salinity could be due to suppression of Na+ accumulation and enhanced physiological and metabolic activities related to photosynthesis, respiration, osmotic regulation, and antioxidant defense. PMID:25551443

  15. Mechanism for enhanced 5-aminolevulinic acid fluorescence in isocitrate dehydrogenase 1 mutant malignant gliomas

    PubMed Central

    Kim, Ji Young; Kim, Sung Kwon; Kim, Seung-Ki; Park, Sung-Hye; Kim, Hyeonjin; Lee, Se-Hoon; Choi, Seung Hong; Park, Sunghyouk; Park, Chul-Kee

    2015-01-01

    Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) has become the main treatment modality in malignant gliomas. However unlike glioblastomas, there are inconsistent result about fluorescence status in WHO grade III gliomas. Here, we show that mutational status of IDH1 is linked to 5-ALA fluorescence. Using genetically engineered malignant glioma cells harboring wild type (U87MG-IDH1WT) or mutant (U87MG-IDH1R132H) IDH1, we demonstrated a lag in 5-ALA metabolism and accumulation of protoporphyrin IX (PpIX) in U87MG-IDH1R132H cells. Next, we used liquid chromatography–mass spectrometry (LC-MS) to screen for tricarboxylic acid (TCA) cycle-related metabolite changes caused by 5-ALA exposure. We observed low baseline levels of NADPH, an essential cofactor for the rate-limiting step of heme degradation, in U87MG-IDH1R132H cells. High levels of NADPH are required to metabolize excessive 5-ALA, giving a plausible reason for the temporarily enhanced 5-ALA fluorescence in mutant IDH1 cells. This hypothesis was supported by the results of metabolic screening in human malignant glioma samples. In conclusion, we have discovered a relationship between enhanced 5-ALA fluorescence and IDH1 mutations in WHO grade III gliomas. Low levels of NADPH in tumors with mutated IDH1 is responsible for the enhanced fluorescence. PMID:26008980

  16. Clinical utility of 5-aminolevulinic acid HCl to better visualize and more completely remove gliomas

    PubMed Central

    Halani, Sameer H; Adamson, D Cory

    2016-01-01

    Surgical resection is typically the first line of treatment for gliomas. However, the neurosurgeon faces a major challenge in achieving maximal resection in high-grade gliomas as these infiltrative tumors make it difficult to discern tumor margins from normal brain with conventional white-light microscopy alone. To aid in resection of these infiltrative tumors, fluorescence-guided surgery has gained much popularity in intraoperative visualization of malignant gliomas, with 5-aminolevulinic acid (5-ALA) leading the way. First introduced in an article in Neurosurgery, 5-ALA has since become a safe, effective, and inexpensive method to visualize and improve resection of gliomas. This has undoubtedly led to improvements in the clinical course of patients as demonstrated by the increased overall and progression-free survival in patients with such devastating disease. This literature review aims to discuss the major studies and trials demonstrating the clinical utility of 5-ALA and its ability to aid in complete resection of malignant gliomas. PMID:27672334

  17. Binding of /sup 14/C-5-aminolevulinic acid to a stromal protein from developing pea chloroplasts

    SciTech Connect

    Thayer, S.S.; Castelfranco, P.A.; Wilkinson, J.; Benson, G.

    1987-04-01

    /sup 14/-5-Aminolevulinic acid (/sup 14/C-ALA) binds to a stromal protein with an apparent molecular weight of 42-43 KD on LDS and non-denaturing gels. The reaction is rapid. Binding is inhibited by sulfhydryl reagents, mM concentrations of levulinic, dihydroxy heptanoic acids and gabaculine, 10 ..mu..M N-methylprotoporphyrin. Dicarboxilic acids, such as deltaKG, Glu, OAA, do not inhibit. Chloramphenicol, ATP, protoporphyrin, anoxia, light, darkness have no effect. The product, once formed, is stable to treatment with 5% conc. HCl in cold acetone. It can be chased in a second incubation with unlabeled ALA, but not with levulinic acid. No activity was detected in the subplastidic membrane fractions. Western blot analysis failed to reveal any homology between the labeled protein and either cytochrome for ALA dehydratase. This ALA-binding protein was not formed in chloroplasts isolated from fully expanded pea leaves. Therefore, it is deemed likely to participate in ALA metabolism during chloroplast development.

  18. Effects of 5-aminolevulinic acid on a murine model of diet-induced obesity

    PubMed Central

    Koganei, Megumi; Saitou, Yuri; Tsuchiya, Kyoko; Abe, Fuminori; Tanaka, Toru; Horinouchi, Izumi; Izumi, Yoshiya; Yamaji, Taketo; Takahashi, Takeshi

    2015-01-01

    The effects of 5-aminolevulinic acid (5-ALA) on obesity were investigated using a murine model (diet-induced obese mice). Diet-induced obese mice were divided into 4 groups: a control group (C group), which was fed a high-fat diet; a low-5-ALA dose (10 mg/kg/day) group (10A group); a moderate-5-ALA dose (30 mg/kg/day) group (30A group); and a high-5-ALA dose (100 mg/kg/day) group (100A group). 5-ALA was administered by mixing the high fat diet for 8 weeks. Body weight increases in the 30A and 100A groups were significantly smaller compared with those of the C group. Body fat measurements by X-ray computed tomography indicated that the 100A group showed a tendency toward low visceral fat quantities during the final week of the study. Visceral fat weights in the 30A and 100A groups were slightly low. The levels of serum alanine aminotransferase (ALT) and total cholesterol (TC) in the 10A group was slightly low, whereas the 30A and 100A groups showed significantly lower ALT and TC values. Liver lipid concentration showed a dose-dependent decrease with ALA. Thus, in this diet-induced obese murine model, administration of 5-ALA had a significantly beneficial impact on the visceral fat, serum ALT and TC, and liver lipid concentration. PMID:26388673

  19. Sonodynamic therapy using 5-aminolevulinic acid enhances the efficacy of bleomycin.

    PubMed

    Osaki, Tomohiro; Ono, Misato; Uto, Yoshihiro; Ishizuka, Masahiro; Tanaka, Tohru; Yamanaka, Nobuyasu; Kurahashi, Tsukasa; Azuma, Kazuo; Murahata, Yusuke; Tsuka, Takeshi; Ito, Norihiko; Imagawa, Tomohiro; Okamoto, Yoshiharu

    2016-04-01

    Sonodynamic therapy (SDT) kills tumor cells through the synergistic effects of ultrasound and a sonosensitizer agent. We examined whether 5-aminolevulinic acid (5-ALA)-based SDT at 1 or 3 MHz could enhance the cytotoxicity of bleomycin (BLM) toward mouse mammary tumor cells both in vitro and in vivo. At 1 MHz, cell viability in the 5-ALA-based SDT group at 1, 2, and 3 W/cm(2) was 34.30%, 50.90%, and 60.16%, respectively. Cell viability in the 5-ALA-based SDT+BLM group at 1, 2, and 3 W/cm(2) was 0.09%, 0.32%, and 0.17%, respectively. In contrast, at 3 MHz, 5-ALA-based SDT+BLM did not show pronounced cytotoxicity. In the in vivo study, 5-ALA-based SDT+BLM was significantly more cytotoxic than 5-ALA-based SDT at 1 MHz and 3 MHz. These findings suggest that the mechanism of tumor shrinkage induced by 5-ALA-based SDT+BLM might involve not only direct cell killing, but also vascular shutdown. Thus, we show here that 5-ALA-based SDT enhances the efficacy of BLM both in vitro and in vivo. PMID:26799128

  20. Physiological and metabolic effects of 5-aminolevulinic acid for mitigating salinity stress in creeping bentgrass.

    PubMed

    Yang, Zhimin; Chang, Zuoliang; Sun, Lihong; Yu, Jingjin; Huang, Bingru

    2014-01-01

    The objectives of this study were to determine whether foliar application of a chlorophyll precursor, 5-aminolevulinic acid (ALA), could mitigate salinity stress damages in perennial grass species by regulating photosynthetic activities, ion content, antioxidant metabolism, or metabolite accumulation. A salinity-sensitive perennial grass species, creeping bentgrass (Agrostis stolonifera), was irrigated daily with 200 mM NaCl for 28 d, which were foliar sprayed with water or ALA (0.5 mg L-1) weekly during the experiment in growth chamber. Foliar application of ALA was effective in mitigating physiological damage resulting from salinity stress, as manifested by increased turf quality, shoot growth rate, leaf relative water content, chlorophyll content, net photosynthetic rate, stomatal conductance and transpiration rate. Foliar application of ALA also alleviated membrane damages, as shown by lower membrane electrolyte leakage and lipid peroxidation, which was associated with increases in the activities of antioxidant enzymes. Leaf content of Na+ was reduced and the ratio of K+/Na+ was increased with ALA application under salinity stress. The positive effects of ALA for salinity tolerance were also associated with the accumulation of organic acids (α-ketoglutaric acid, succinic acid, and malic acid), amino acids (alanine, 5-oxoproline, aspartic acid, and γ -aminobutyric acid), and sugars (glucose, fructose, galactose, lyxose, allose, xylose, sucrose, and maltose). ALA-mitigation of physiological damages by salinity could be due to suppression of Na+ accumulation and enhanced physiological and metabolic activities related to photosynthesis, respiration, osmotic regulation, and antioxidant defense.

  1. 5-aminolevulinic acid and neuronavigation in high-grade glioma surgery: results of a combined approach.

    PubMed

    Panciani, Pier Paolo; Fontanella, Marco; Garbossa, Diego; Agnoletti, Alessandro; Ducati, Alessandro; Lanotte, Michele

    2012-02-01

    In high-grade glioma surgery, several techniques are used to achieve the maximum cytoreductive treatment preserving neurological functions. However, the effectiveness of all the methods used alone is reduced by specific limitations of each. We assessed the reliability of a multimodal strategy based on 5-aminolevulinic acid (5-ALA) and neuronavigation. We prospectively studied 18 patients with suspected, non eloquent-area malignant gliomas amenable for complete resection. Conventional illumination was used until the excision appeared complete. The cavity was then systematically inspected in violet-blue light to identify any residual tumour. Multiple biopsies of both fluorescent and non-fluorescent tissue were performed in all cases. Each specimen was labelled according to the sampling location (inside or outside the boundary set by the neuronavigator). The samples were analysed by a neuropathologist blinded to the intraoperative classification. We reviewed the results of both methods, either singly or in combination. Individual analysis showed higher 5-ALA reliability compared to neuronavigation. However, several false-negative fluorescent specimens were detected. With the combined use of fluorescence and neuroimaging, only 1 sample (negative for both 5-ALA and navigation) was tumoral tissue. In our experience, the combined approach showed the best sensitivity and it is recommended in cases of lesions involving non-eloquent areas.

  2. Optimization of the heme biosynthesis pathway for the production of 5-aminolevulinic acid in Escherichia coli

    PubMed Central

    Zhang, Junli; Kang, Zhen; Chen, Jian; Du, Guocheng

    2015-01-01

    5-Aminolevulinic acid (ALA), the committed intermediate of the heme biosynthesis pathway, shows significant promise for cancer treatment. Here, we identified that in addition to hemA and hemL, hemB, hemD, hemF, hemG and hemH are also the major regulatory targets of the heme biosynthesis pathway. Interestingly, up-regulation of hemD and hemF benefited ALA accumulation whereas overexpression of hemB, hemG and hemH diminished ALA accumulation. Accordingly, by combinatorial overexpression of the hemA, hemL, hemD and hemF with different copy-number plasmids, the titer of ALA was improved to 3.25 g l−1. Furthermore, in combination with transcriptional and enzymatic analysis, we demonstrated that ALA dehydratase (HemB) encoded by hemB is feedback inhibited by the downstream intermediate protoporphyrinogen IX. This work has great potential to be scaled-up for microbial production of ALA and provides new important insights into the regulatory mechanism of the heme biosynthesis pathway. PMID:25716896

  3. Transcriptomic analysis for elucidating the physiological effects of 5-aminolevulinic acid accumulation on Corynebacterium glutamicum.

    PubMed

    Yu, Xiaoli; Jin, Haiying; Cheng, Xuelian; Wang, Qian; Qi, Qingsheng

    2016-11-01

    5-Aminolevulinic acid (ALA), the committed intermediate of the heme biosynthetic pathway, attracts close attention among researchers because of its potential applications to cancer treatment and agriculture. Overexpression of heterologous hemA and hemL, which encode glutamyl-tRNA reductase and glutamate-1-semialdehyde aminotransferase, respectively, in Corynebacterium glutamicum produces ALA, although whether ALA accumulation causes unintended effects on the host is unknown. Here we used an integrated systems approach to compare global transcriptional changes induced by the expression of hemA and hemL. Metabolic pathway such as glycolysis was inhibited, but tricarboxylic acid cycle, pentose phosphate pathway, and respiratory metabolism were stimulated. Moreover, the transcriptional levels of certain genes involved in heme biosynthesis were up-regulated, and the data implicate the two-component system (TCS) HrrSA was involved in the regulation of heme synthesis. With these understandings, it is proposed that ALA accumulation stimulates heme synthesis pathway and respiratory metabolism. Our study illuminates the physiological effects of overexpressing hemA and hemL on the phenotype of C. glutamicum and contributes important insights into the regulatory mechanisms of the heme biosynthetic pathways. PMID:27664748

  4. Alternative Routes for the Synthesis of 5-Aminolevulinic Acid in Maize Leaves 1

    PubMed Central

    Harel, Eitan; Ne'Eman, Emma

    1983-01-01

    Intact plastids from greening maize (Zea mays L.) leaves converted [14C]glutamate and [14C]2-ketoglutarate (KG) to [14C]5-aminolevulinic acid (ALA). Glutamate appeared to be the immediate precursor of ALA, while KG was first converted to glutamate, as shown by the effect of various inhibitors of amino acid metabolism. Plastids from greening leaves contained markedly higher activity as compared with etioplasts or chloroplasts. The synthesis of ALA by intact plastids was light dependent. The enzyme system resides in the stroma of plastids or may be lightly bound to membranes. The solubilized system showed maximal activity around pH 7.9 and required Mg2+, ATP, and NADPH although dependence on the latter was not clear-cut. A relatively high level of activity could be extracted from etioplasts. Maximal activity was obtained from plastids of leaves which had been illuminated for 90 minutes, after which activity declined sharply. The enzyme system solubilized from plastids also catalyzed the conversion of putative glutamate 1-semialdehyde to ALA in a reaction which was not dependent on the addition of an amino donor. The system in maize greatly resembled the one which had been reported from barley. It is suggested that this system is the one responsible for the biosynthesis of ALA destined for chlorophyll formation. PMID:16663121

  5. Increased Histone Deacetylase Activity Involved in the Suppressed Invasion of Cancer Cells Survived from ALA-Mediated Photodynamic Treatment

    PubMed Central

    Li, Pei-Tzu; Tsai, Yi-Jane; Lee, Ming-Jen; Chen, Chin-Tin

    2015-01-01

    Previously, we have found that cancer cells survived from 5-Aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) have abnormal mitochondrial function and suppressed cellular invasiveness. Here we report that both the mRNA expression level and enzymatic activity of histone deacetylase (HDAC) were elevated in the PDT-derived variants with dysfunctional mitochondria. The activated HDAC deacetylated histone H3 and further resulted in the reduced migration and invasion, which correlated with the reduced expression of the invasion-related genes, matrix metalloproteinase 9 (MMP9), paternally expressed gene 1 (PEG1), and miR-355, the intronic miRNA. Using chromatin immunoprecipitation, we further demonstrate the reduced amount of acetylated histone H3 on the promoter regions of MMP9 and PEG1, supporting the down-regulation of these two genes in PDT-derived variants. These results indicate that HDAC activation induced by mitochondrial dysfunction could modulate the cellular invasiveness and its related gene expression. This argument was further verified in the 51-10 cybrid cells with the 4977 bp mtDNA deletion and A375 ρ0 cells with depleted mitochondria. These results indicate that mitochondrial dysfunction might suppress tumor invasion through modulating histone acetylation. PMID:26473836

  6. Topical delivery of 5-aminolevulinic acid-encapsulated ethosomes in a hyperproliferative skin animal model using the CLSM technique to evaluate the penetration behavior.

    PubMed

    Fang, Yi-Ping; Huang, Yaw-Bin; Wu, Pao-Chu; Tsai, Yi-Hung

    2009-11-01

    Psoriasis, an inflammatory skin disease, exhibits recurring itching, soreness, and cracked and bleeding skin. Currently, the topical delivery of 5-aminolevulinic acid-photodynamic therapy (ALA-PDT) is an optional treatment for psoriasis which provides long-term therapeutic effects, is non-toxic and enjoys better compliance with patients. However, the precursor of ALA is hydrophilic, and thus its ability to penetrate the skin is limited. Also, little research has provided a platform to investigate the penetration behavior in disordered skin. We employed a highly potent ethosomal carrier (phosphatidylethanolamine; PE) to investigate the penetration behavior of ALA and the recovery of skin in a hyperproliferative murine model. We found that the application of ethosomes produced a significant increase in cumulative amounts of 5-26-fold in normal and hyperproliferative murine skin samples when compared to an ALA aqueous solution; and the ALA aqueous solution appeared less precise in terms of the penetration mode in hyperproliferative murine skin. After the ethosomes had been applied, the protoporphyrin IX (PpIX) intensity increased about 3.64-fold compared with that of the ALA aqueous solution, and the penetration depth reached 30-80 microm. The results demonstrated that the ethosomal carrier significantly improved the delivery of ALA and the formation of PpIX in both normal and hyperproliferative murine skin samples, and the expression level of tumor necrosis factor (TNF)-alpha was reduced after the ALA-ethosomes were applied to treat hyperproliferative murine skin. Furthermore, the results of present study encourage more investigations on the mechanism of the interaction with ethosomes and hyperproliferative murine skin.

  7. Topical delivery of 5-aminolevulinic acid-encapsulated ethosomes in a hyperproliferative skin animal model using the CLSM technique to evaluate the penetration behavior.

    PubMed

    Fang, Yi-Ping; Huang, Yaw-Bin; Wu, Pao-Chu; Tsai, Yi-Hung

    2009-11-01

    Psoriasis, an inflammatory skin disease, exhibits recurring itching, soreness, and cracked and bleeding skin. Currently, the topical delivery of 5-aminolevulinic acid-photodynamic therapy (ALA-PDT) is an optional treatment for psoriasis which provides long-term therapeutic effects, is non-toxic and enjoys better compliance with patients. However, the precursor of ALA is hydrophilic, and thus its ability to penetrate the skin is limited. Also, little research has provided a platform to investigate the penetration behavior in disordered skin. We employed a highly potent ethosomal carrier (phosphatidylethanolamine; PE) to investigate the penetration behavior of ALA and the recovery of skin in a hyperproliferative murine model. We found that the application of ethosomes produced a significant increase in cumulative amounts of 5-26-fold in normal and hyperproliferative murine skin samples when compared to an ALA aqueous solution; and the ALA aqueous solution appeared less precise in terms of the penetration mode in hyperproliferative murine skin. After the ethosomes had been applied, the protoporphyrin IX (PpIX) intensity increased about 3.64-fold compared with that of the ALA aqueous solution, and the penetration depth reached 30-80 microm. The results demonstrated that the ethosomal carrier significantly improved the delivery of ALA and the formation of PpIX in both normal and hyperproliferative murine skin samples, and the expression level of tumor necrosis factor (TNF)-alpha was reduced after the ALA-ethosomes were applied to treat hyperproliferative murine skin. Furthermore, the results of present study encourage more investigations on the mechanism of the interaction with ethosomes and hyperproliferative murine skin. PMID:19660544

  8. Alleviation of salt-induced oxidative damage by 5-aminolevulinic acid in wheat seedlings

    NASA Astrophysics Data System (ADS)

    Genişel, Mucip; Erdal, Serkan

    2016-04-01

    The aim of this study was to elucidate how 5-aminolevulinic acid (ALA), the precursor of chlorophyll compounds, affects the defence mechanisms of wheat seedlings induced by salt stress. To determine the possible stimulative effects of ALA against salinity, 11-day old wheat seedlings were sprayed with ALA at two different concentrations (10 and 20 mg.l-1) and then stressed by exposure to salt (150 mM NaCl). The salt stress led to significant changes in the antioxidant activity. While guaiacol peroxidase activity decreased, the activities of superoxide dismutase, catalase, and ascorbate peroxidase markedly increased under salt stress. Compared to the salt stress alone, the application of ALA beforehand further increased the activity of these enzymes. This study is the first time the effects of ALA have been monitored with regard to protein content and the isoenzyme profiles of the antioxidant enzymes. Although the salt stress reduced both the soluble protein content and protein band intensities, pre-treating with ALA significantly mitigated these stress-induced reductions. The data for the isoenzyme profiles of the antioxidant enzymes paralleled that of the ALA-induced increases in antioxidant activity. As a consequence of the high antioxidant activity in the seedlings pre-treated with ALA, the stress-induced elevations in the reactive oxygen species, superoxide anion, and hydrogen peroxide contents and lipid peroxidation levels were markedly diminished. Taken together, this data demonstrated that pre-treating with ALA confers resistance to salt stress by modulating the protein synthesis and antioxidant activity in wheat seedlings.

  9. [Effect of 5-aminolevulinic acid on photosynthetic characteristics of tomato seedlings under NaCl stress].

    PubMed

    Zhao, Yan-Yan; Yan, Fei; Hu, Li-Pan; Zhou, Xiao-Ting; Zou, Zhi-Rong

    2014-10-01

    In this research, the possibility of exogenous application of 5-aminolevulinic acid (ALA) on photosynthetic characteristics of tomato seedlings under NaCl stress was investigated. Five leaves seedlings of tomato (Solanum lycopersicum cv. Jinpeng No. 1) were used as starting materials, applied with 50 mg · L(-1) ALA by foliage spray or 10 mg · L(-1) ALA by root soaking to study the changes in their photosynthesis and fluorescence parameters under 100 mmol · L(-1) NaCl. The result showed that, photosynthetic gas exchange parameters (net photosynthetic rate P,, stomata conductance g(s), intercellular CO2 concentration Ci, transpiration Tr) and chlorophyll fluorescence parameters (Fv'/Fm', Fm', ΦPS II, ETR, qP, Pc) were severely reduced under NaCl treatment and ALA application by foliage spray or root soaking with proper concentrations exerted positive influences on tomato seedlings under salt stress, while there were some differences between foliage spray and root soaking in the influence on chlorophyll content, photosynthesis and chlorophyll fluorescence. Both foliage spray with 50 mg · L(-1) ALA and root soaking with 10 mg L(-1) ALA significantly increased Pn, Ci, g(s) and Tr of tomato seedlings under NaCl stress, alleviated photosynthetic inhibition. Root application of ALA had a better effect on the chlorophyll content than foliage application. However, the photosynthetic parameters showed that foliage application of ALA had a better effect than root application, and both treatments had no difference in the influence on chlorophyll fluorescence parameters of tomato seedlings. It could be deduced that the regulating effect of ALA on enhancing salt tolerance of tomato seedlings is attributed to its effect on improving chlorophyll biosynthesis and metabolism, increasing stomatal conductance and reducing stomatal limitation, thus, enhancing the photosynthetic capacity and PS II photochemical efficiency of tomato leaves under NaCl stress. PMID:25796901

  10. 5-Aminolevulinate production by Escherichia coli containing the Rhodobacter sphaeroides hemA gene

    SciTech Connect

    Van Der Werf, M.J.; Zeikus, J.G. |

    1996-10-01

    The Rhodobacter sphaeroides hemA gene codes for 5-aminolevulinate (ALA) synthase. This enzyme catalyzes the pyridoxal phosphate-dependent condensation of succinyl coenzyme A and glycine-forming ALA. The R. sphaeroides hemA gene in the pUC18/19 vector system was transformed into Escherichia coli. The effects of both genetic and physiological factors on the expression of ALA synthase and the production of ALA were studied. ALA synthase activity levels were maximal when hemA had the same transcription direction as the lac promoter. The distance between the lac promoter and hemA affected the expression of ALA synthase on different growth substrates. The E. coli host strain used had an enormous effect on the ALA synthase activity level and on the production of ALA, with E. coli DH1 being best suited. The ALA synthase activity level was also dependent on the carbon source. Succinate, L-malate, fumarate, and L-aspartate gave the highest levels of ALA synthase activity, while the use of lactose as a carbon source resulted in a repression of ALA synthase. After growth on succinate, ALA synthase represented {approx}5% of total cellular protein. The ALA synthase activity level was also dependent on the pH of the medium, with maximal activity occurring at pH 6.5. ALA production by whole cells was limited by the availability of glycine, and the addition of 2 g of glycine per liter to the growth medium increased the production of ALA fivefold, to 2.25 mM. In recombinant E. coli extracts, up to 22 mM ALA was produced from succinate, glycine, and ATP. 58 refs., 4 figs., 7 tabs.

  11. [Effect of 5-aminolevulinic acid on photosynthetic characteristics of tomato seedlings under NaCl stress].

    PubMed

    Zhao, Yan-Yan; Yan, Fei; Hu, Li-Pan; Zhou, Xiao-Ting; Zou, Zhi-Rong

    2014-10-01

    In this research, the possibility of exogenous application of 5-aminolevulinic acid (ALA) on photosynthetic characteristics of tomato seedlings under NaCl stress was investigated. Five leaves seedlings of tomato (Solanum lycopersicum cv. Jinpeng No. 1) were used as starting materials, applied with 50 mg · L(-1) ALA by foliage spray or 10 mg · L(-1) ALA by root soaking to study the changes in their photosynthesis and fluorescence parameters under 100 mmol · L(-1) NaCl. The result showed that, photosynthetic gas exchange parameters (net photosynthetic rate P,, stomata conductance g(s), intercellular CO2 concentration Ci, transpiration Tr) and chlorophyll fluorescence parameters (Fv'/Fm', Fm', ΦPS II, ETR, qP, Pc) were severely reduced under NaCl treatment and ALA application by foliage spray or root soaking with proper concentrations exerted positive influences on tomato seedlings under salt stress, while there were some differences between foliage spray and root soaking in the influence on chlorophyll content, photosynthesis and chlorophyll fluorescence. Both foliage spray with 50 mg · L(-1) ALA and root soaking with 10 mg L(-1) ALA significantly increased Pn, Ci, g(s) and Tr of tomato seedlings under NaCl stress, alleviated photosynthetic inhibition. Root application of ALA had a better effect on the chlorophyll content than foliage application. However, the photosynthetic parameters showed that foliage application of ALA had a better effect than root application, and both treatments had no difference in the influence on chlorophyll fluorescence parameters of tomato seedlings. It could be deduced that the regulating effect of ALA on enhancing salt tolerance of tomato seedlings is attributed to its effect on improving chlorophyll biosynthesis and metabolism, increasing stomatal conductance and reducing stomatal limitation, thus, enhancing the photosynthetic capacity and PS II photochemical efficiency of tomato leaves under NaCl stress.

  12. Blood interference in fiber-optical based fluorescence guided resection of glioma using 5-aminolevulinic acid

    NASA Astrophysics Data System (ADS)

    Haj-Hosseini, Neda; Lowndes, Shannely; Salerud, Göran; Wårdell, Karin

    2011-03-01

    Fluorescence guidance in brain tumor resection is performed intra-operatively where bleeding is included. When using fiber-optical probes, the transmission of light to and from the tissue is totally or partially blocked if a small amount of blood appears in front of the probe. Sometimes even after rinsing with saline, the remnant blood cells on the optical probe head, disturb the measurements. In such a case, the corresponding spectrum cannot be reliably quantified and is therefore discarded. The optimal case would be to calculate and take out the blood effect systematically from the collected signals. However, the first step is to study the pattern of blood interference in the fluorescence spectrum. In this study, a fiber-optical based fluorescence spectroscopy system with a laser excitation light of 405 nm (1.4 J/cm2) was used during fluorescence guided brain tumor resection using 5-aminolevulinic acid (5-ALA). The blood interference pattern in the fluorescence spectrum collected from the brain was studied in two patients. The operation situation was modeled in the laboratory by placing blood drops from the finger tip on the skin of forearm and the data was compared to the brain in vivo measurements. Additionally, a theoretical model was developed to simulate the blood interference pattern on the skin autofluorescence. The blood affects the collected fluorescence intensity and leaves traces of oxy and deoxy-hemoglobin absorption peaks. According to the developed theoretical model, the autofluorescence signal is considered to be totally blocked by an approximately 500 μm thick blood layer.

  13. Photodynamic therapy using light-emitting diodes for the treatment of viral warts.

    PubMed

    Ohtsuki, Akiko; Hasegawa, Toshio; Hirasawa, Yusuke; Tsuchihashi, Hitoshi; Ikeda, Shigaku

    2009-10-01

    Photodynamic therapy with topical 5-aminolevulinic acid is an effective and safe treatment for actinic keratosis and superficial non-melanoma skin cancer. Further, some studies have reported good efficacy when using photodynamic therapy to treat viral warts. The light-emitting diode is an incoherent, narrow-spectrum light source. The purpose of this study is to evaluate the efficacy of photodynamic therapy using a light-emitting diode for viral warts. Six patients with a total of 41 foot and hand warts were recruited in this study. They were treated with 20% 5-aminolevulinic acid cream under occlusion for 5 h. Thereafter, the treated area was irradiated with the light from a red light-emitting diode (633 +/- 6 nm) with a dose of 126 J/cm(2). This treatment was repeated at 2- or 3-week intervals. The rate of improvement observed in patients was 68.3%. The adverse effects included mild to moderate pain and erythema, which was well-tolerated by all six patients. No patients withdrew from the study due to the adverse effects. Photodynamic therapy with topical 5-aminolevulinic acid using the light from a red light-emitting diode has the advantage of non-invasiveness, minimal associated adverse reactions, and production of good results in a significant proportion of cases: therefore, it is an alternative treatment for recalcitrant viral warts.

  14. Imiquimod immunotherapy and ALA photodynamic therapy combination for the treatment of genital bowenoid papulosis

    NASA Astrophysics Data System (ADS)

    Wang, Xiu-Li; Wang, Hong-Wei; Guo, Ming-Xia; Huang, Zheng

    2007-02-01

    To investigate the feasibility and efficacy of combination of imiquimod immunotherapy and 5- aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) for the treatment of genital bowenoid papulosis (BP). A total of twenty seven BP patients were randomized into two groups: (I) fifteen patients (12 male and 3 female, age 22-56 years old) were treated with topical application of 5% imiquimod cream (three times a week) and ALA-PDT (100 J/cm2 at 100 mW/cm2, once a week) for 1-4 times in one week interval. (II) Twelve patients (6 male and 6 female, age 29-58 years old) were treated with CO II laser vaporization as a control. Patients were followed up for 3 to 12 months. Results: In combined therapy group, 60% (9/15) patients showed complete remission and only one recurred (11.1%) during follow up. Local side effects included mild erythema, edema, erosion and burning and/or stinging sensation. No systemic side effect was found. In CO II laser vaporization group, 83.3% (10/12) patients showed complete remission. However, recurrence occurred in 6 patients (60.0%). Local side effects included mild to moderate edema, erosion, ulceration, delayed healing, prolonged pain and scarring. The difference of recurrence rate between two groups was statistically significant (P < 0.05). Topical application of imiquimod cream and ALA-PDT is safe, effective and associated with low recurrence and less side effect. Its true clinical value needs to be further investigated by a long-term follow-up of large scale trial.

  15. Risk factors for developing oral 5-aminolevulinic acid-induced side effects in patients undergoing fluorescence guided resection.

    PubMed

    Chung, Ivan Wong Hin; Eljamel, Sam

    2013-12-01

    Oral 5 aminolevulinic acid (5-ALA) is used to assist surgical resection of malignant tumours in the brain and other locations. Hypotension and alteration of liver functions have been reported as potential adverse effects. This study was designed to assess the incidence and contributing factors that cause 5-ALA induced side effects in a cohort of 90 patients. Hypotension occurred in 11% of patients irrespective of 5-ALA dose. The only contributing factor was the presence of cardiovascular disease and antihypertensive drug therapy with an odd ratio of 17.7. Liver function were disturbed in 2% in patients who received 20mg or less/kg body weight compared to 4% in those who received a dose of >20mg/kg 5-ALA. The liver dysfunction was minor and was not clinically significant. We concluded that 5-ALA induced side effects were minimal and hypotension more likely to occur in patients receiving antihypertensive drug therapy.

  16. Optimization of Influencing Factors on Biomass Accumulation and 5-Aminolevulinic Acid (ALA) Yield in Rhodobacter sphaeroides Wastewater Treatment.

    PubMed

    Liu, Shuli; Li, Xiangkun; Zhang, Guangming; Zhang, Jie

    2015-11-01

    This study aimed to optimize four factors affecting biomass accumulation and 5-aminolevulinic acid (ALA) yield together with pollutants removal in Rhodobacter sphaeroides wastewater treatment. Results showed that it was feasible to produce biomass and ALA in R. sphaeroides wastewater treatment. Microaerobic, 1,000-3,000 lux, and pH 7.0 were optimal conditions for the highest ALA yield of 4.5 ± 0.5 mg/g-biomass. Under these conditions, COD removal and biomass production rate were 93.3 ± 0.9% and 31.8 ± 0.5 mg/l/h, respectively. In addition, trace elements Fe(2+), Mg(2+), Ni(2+), and Zn(2+) further improved the ALA yield, COD removal, and biomass production rate. Specifically, the highest ALA yield (12.5 ± 0.6 mg/g-biomass) was achieved with Fe(2+) addition.

  17. The heme precursor 5-aminolevulinic acid disrupts the Warburg effect in tumor cells and induces caspase-dependent apoptosis.

    PubMed

    Sugiyama, Yuta; Hagiya, Yuichiro; Nakajima, Motowo; Ishizuka, Masahiro; Tanaka, Tohru; Ogura, Shun-Ichiro

    2014-03-01

    Our previous study demonstrated that 5-aminolevulinic acid (ALA) administered to mice stimulates oxidative phosphorylation by upregulation of the mitochondrial respiratory chain complex IV enzyme cytochrome c oxidase (COX). The present study investigated whether ALA disrupts the Warburg effect, which represents a shift in ATP generation from oxidative phosphorylation to glycolysis, protecting tumor cells against oxidative stress-mediated apoptosis. The human lung carcinoma cell line A549 exposed to ALA exhibited enhanced oxidative phosphorylation, which was indicated by an increase in COX protein expression and oxygen consumption. Furthermore, ALA suppressed glycolysis-mediated acidosis. This normalization of the ATP metabolic pathways significantly increased the generation of superoxide anion radical (O2•-) and the functional expression of active caspase-3, leading to caspase-dependent apoptosis. These data demonstrate that ALA inhibits the Warburg effect and induces cancer cell death. Use of this endogenous compound might constitute a novel approach to cancer therapy. PMID:24366173

  18. Human Erythroid 5-Aminolevulinate Synthase Mutations Associated with X-Linked Protoporphyria Disrupt Conformational Equilibrium and Enhance Product Release†

    PubMed Central

    Fratz, Erica J.; Clayton, Jerome; Hunter, Gregory A.; Ducamp, Sarah; Breydo, Leonid; Uversky, Vladimir N.; Deybach, Jean-Charles; Gouya, Laurent; Puy, Hervé; Ferreira, Gloria C.

    2015-01-01

    Regulation of 5-aminolevulinate synthase (ALAS) is at the origin of balanced heme production in mammals. Mutations in the C-terminal region of human erythroid-specific ALAS (hALAS2) are associated with X-linked protoporphyria (XLPP), a disease characterized by extreme photosensitivity, with elevated blood concentrations of free protoporphyrin IX and zinc protoporphyrin. To investigate the molecular basis for this disease, recombinant hALAS2 and variants of the enzyme harboring the gain-of-function XLPP mutations were constructed, purified, and analyzed kinetically, spectroscopically and thermodynamically. Enhanced activities of the XLPP variants resulted from accelerations in the rate at which the product 5-aminolevulinate (ALA) was released from the enzyme. Circular dichroism spectroscopy revealed that the XLPP mutations altered the microenvironment of the pyridoxal 5’-phosphate cofactor, which underwent further and specific alterations upon succinyl-CoA binding. Transient kinetic analyses of the variant-catalyzed reactions and protein fluorescence quenching upon ALA binding to the XLPP variants demonstrated that the protein conformational transition step associated with product release was predominantly affected. Of relevance, XLPP could also be modeled in cell culture. We propose that 1) the XLPP mutations destabilize the succinyl-CoA-induced hALAS2 closed conformation and thus accelerate ALA release, 2) the extended C-terminus of wild-type mammalian ALAS2 provides a regulatory role that allows for allosteric modulation of activity, thereby controlling the rate of erythroid heme biosynthesis, and 3) this control is disrupted in XLPP, resulting in porphyrin accumulation. PMID:26300302

  19. Asn-150 of Murine Erythroid 5-Aminolevulinate Synthase Modulates the Catalytic Balance between the Rates of the Reversible Reaction.

    PubMed

    Stojanovski, Bosko M; Ferreira, Gloria C

    2015-12-25

    5-Aminolevulinate synthase (ALAS) catalyzes the first step in mammalian heme biosynthesis, the pyridoxal 5'-phosphate (PLP)-dependent and reversible reaction between glycine and succinyl-CoA to generate CoA, CO2, and 5-aminolevulinate (ALA). Apart from coordinating the positioning of succinyl-CoA, Rhodobacter capsulatus ALAS Asn-85 has a proposed role in regulating the opening of an active site channel. Here, we constructed a library of murine erythroid ALAS variants with substitutions at the position occupied by the analogous bacterial asparagine, screened for ALAS function, and characterized the catalytic properties of the N150H and N150F variants. Quinonoid intermediate formation occurred with a significantly reduced rate for either the N150H- or N150F-catalyzed condensation of glycine with succinyl-CoA during a single turnover. The introduced mutations caused modifications in the ALAS active site such that the resulting variants tipped the balance between the forward- and reverse-catalyzed reactions. Although wild-type ALAS catalyzes the conversion of ALA into the quinonoid intermediate at a rate 6.3-fold slower than the formation of the same quinonoid intermediate from glycine and succinyl-CoA, the N150F variant catalyzes the forward reaction at a mere 1.2-fold faster rate than that of the reverse reaction, and the N150H variant reverses the rate values with a 1.7-fold faster rate for the reverse reaction than that for the forward reaction. We conclude that the evolutionary selection of Asn-150 was significant for optimizing the forward enzymatic reaction at the expense of the reverse, thus ensuring that ALA is predominantly available for heme biosynthesis.

  20. Effect of 5-aminolevulinic acid on erythropoiesis: A preclinical in vitro characterization for the treatment of congenital sideroblastic anemia

    SciTech Connect

    Fujiwara, Tohru; Takahashi, Kiwamu; Okitsu, Yoko; Fukuhara, Noriko; Onishi, Yasushi; Ishizawa, Kenichi; Ichinohasama, Ryo; Nakamura, Yukio; Nakajima, Motowo; Tanaka, Tohru; Harigae, Hideo

    2014-11-07

    Highlights: • Treatment with ALA induces erythroid differentiation of K562 cells. • Transportation of ALA into erythroid cells occurs predominantly via SLC36A1. • ALA restores defects in ALAS2 in human iPS cell-derived erythroblasts. • ALA may represent a novel therapeutic option for CSA caused by ALAS2 mutations. - Abstract: Congenital sideroblastic anemia (CSA) is a hereditary disorder characterized by microcytic anemia and bone marrow sideroblasts. The most common form of CSA is attributed to mutations in the X-linked gene 5-aminolevulinic acid synthase 2 (ALAS2). ALAS2 is a mitochondrial enzyme, which utilizes glycine and succinyl-CoA to form 5-aminolevulinic acid (ALA), a crucial precursor in heme synthesis. Therefore, ALA supplementation could be an effective therapeutic strategy to restore heme synthesis in CSA caused by ALAS2 defects. In a preclinical study, we examined the effects of ALA in human erythroid cells, including K562 cells and human induced pluripotent stem cell-derived erythroid progenitor (HiDEP) cells. ALA treatment resulted in significant dose-dependent accumulation of heme in the K562 cell line. Concomitantly, the treatment substantially induced erythroid differentiation as assessed using benzidine staining. Quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis confirmed significant upregulation of heme-regulated genes, such as the globin genes [hemoglobin alpha (HBA) and hemoglobin gamma (HBG)] and the heme oxygenase 1 (HMOX1) gene, in K562 cells. Next, to investigate the mechanism by which ALA is transported into erythroid cells, quantitative RT-PCR analysis was performed on previously identified ALA transporters, including solute carrier family 15 (oligopeptide transporter), member (SLC15A) 1, SLC15A2, solute carrier family 36 (proton/amino acid symporter), member (SLC36A1), and solute carrier family 6 (neurotransmitter transporter), member 13 (SLC6A13). Our analysis revealed that SLC36A1 was abundantly

  1. Formation of protoporphyrin IX in mouse skin after topical application of 5-aminolevulinic acid and its methyl esther

    NASA Astrophysics Data System (ADS)

    Sorensen, Roar; Juzenas, Petras; Iani, Vladimir; Moan, Johan

    1999-02-01

    Normal skin of nude mice (Balb/c) was treated topically with 5-aminolevulinic acid (ALA) and its methyl ester (ALA-Me) for 24 hours. Approximately 0.1 gram of freshly prepared cream was applied to a spot of 1 cm2 on the flank of the mice, which was then covered with a transparent dressing. The ALA induced protoporphyrin IX (PpIX) was studied by means of a noninvasive fiber-optic fluorescence probe connected to a luminescence spectrometer. The excitation wavelength was 407 nm, and the emission wavelength was 637 nm. For the first hour a slight lag in PpIX production was observed for the mice treated with ALA-Me compared to the mice treated with ALA. After approximately 12 hours the ALA and the ALA-Me treated mice showed the same PpIX fluorescence intensity. From 12 hours until 24 hours the PpIX fluorescence intensity decreased for both treatment modalities, even though ALA and ALA-Me were continuously present. At 24 hours ALA-Me-treated mice had less than half the amount of PpIX in their skin compared with ALA- treated mice.

  2. Clearance of protoporphyrin IX from mouse skin after topical application of 5-aminolevulinic acid and its methyl ester

    NASA Astrophysics Data System (ADS)

    Juzenas, Petras; Sorensen, Roar; Iani, Vladimir; Moan, Johan

    1999-02-01

    The clearance of protoporphyrin IX (PpIX) from the skin of hairless BALB/c mice after topical application of 5- aminolevulinic acid (ALA) and its methyl ester (ALA-Me) was investigated. Creams containing 2 or 20% of ALA or ALA-Me were topically applied on spots of approximately 1 cm2 for 12 hours. The PpIX fluorescence was detected by the means of a Perkin Elmer LS50B luminescence spectrometer equipped with a fiber-optic probe. The emission spectrum was identical with that of cell-bound PpIX. After 12 hours application of ALA and ALA-Me similar amounts of PpIX were found. After creme removal the ALA-induced PpIX fluorescence decayed with a half-life of about 20 hours (20% ALA cream). The ALA-Me-induced PpIX was faster cleared from the skin than ALA-induced PpIX, and had a half-life of about 7 hours (20% ALA-Me cream).

  3. Optimization of Biomass and 5-Aminolevulinic Acid Production by Rhodobacter sphaeroides ATCC17023 via Response Surface Methodology.

    PubMed

    Liu, Shuli; Zhang, Guangming; Li, Jianzheng; Li, Xiangkun; Zhang, Jie

    2016-06-01

    Microbial 5-aminolevulinic acid (ALA) produced from wastewater is considered as potential renewable energy. However, many hurdles are needed to be overcome such as the regulation of key influencing factors on ALA yield. Biomass and ALA production by Rhodobacter sphaeroides was optimized using response surface methodology. The culturing medium was artificial volatile fatty acids wastewater. Three additives were optimized, namely succinate and glycine that are precursors of ALA biosynthesis, and D-glucose that is an inhibitor of ALA dehydratase. The optimal conditions were achieved by analyzing the response surface plots. Statistical analysis showed that succinate at 8.56 mmol/L, glycine at 5.06 mmol/L, and D-glucose at 7.82 mmol/L were the best conditions. Under these optimal conditions, the highest biomass production and ALA yield of 3.55 g/L and 5.49 mg/g-biomass were achieved. Subsequent verification experiments at optimal values had the maximum biomass production of 3.41 ± 0.002 g/L and ALA yield of 5.78 ± 0.08 mg/g-biomass. PMID:26875086

  4. Comparison of the beluga whale (Delphinapterus leucas) expressed genes for 5-aminolevulinate synthase with those in other vertebrates.

    PubMed

    Kreiling, J A; Duncan, R; Faggart, M A; Cornell, N W

    1999-06-01

    The cDNA and inferred amino acid sequences were determined for beluga whale (Delphinapterus leucas) erythroid (E) and housekeeping (H) forms of 5-aminolevulinate synthase (ALS), and they were compared with known sequences for five other vertebrates with particular attention to regulatory features. The cDNAs for whale ALS-E and -H encode, respectively, proteins of 582 and 640 amino acids. Sequence alignments suggest that the whale ALS-H, like those for rat and chicken, has an N-terminal mitochondrial targeting sequence of 56 amino acids. There is a high degree of amino acid conservation between the beluga whale proteins and those of other vertebrates, including regulatory elements and functional residues that have been defined in other ALSs. Both whale proteins contain three heme regulatory motifs suggesting that mitochondrial uptake may be regulated by heme. The ALS-E mRNA contains an iron responsive element in its 5'-untranslated region indicating that its expression may be post-transcriptionally regulated by cellular iron. This extensive structural similarity and the presence of the same regulatory elements found in other ALSs indicate that regulation of ALS in beluga whale is similar to that in other vertebrates.

  5. Nitric Oxide Mediates 5-Aminolevulinic Acid-Induced Antioxidant Defense in Leaves of Elymus nutans Griseb. Exposed to Chilling Stress

    PubMed Central

    Fu, Juanjuan; Chu, Xitong; Sun, Yongfang; Miao, Yanjun; Xu, Yuefei; Hu, Tianming

    2015-01-01

    Nitric oxide (NO) and 5-aminolevulinic acid (ALA) are both extremely important signalling molecules employed by plants to control many aspects of physiology. In the present study, the role of NO in ALA-induced antioxidant defense in leaves of two sources of Elymus nutans Griseb. (Damxung, DX and Zhengdao, ZD) was investigated. Chilling stress enhanced electrolyte leakage, accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide radical in two E. nutans, which were substantially alleviated by exogenous ALA and NO application. Pretreatment with NO scavenger PTIO or NOS inhibitor L-NNA alone and in combination with ALA induced enhancements in electrolyte leakage and the accumulation of MDA, H2O2 and superoxide radical in leaves of DX and ZD exposed to chilling stress, indicating that the inhibition of NO biosynthesis reduced the chilling resistance of E. nutans and the ALA-enhanced chilling resistance. Further analyses showed that ALA and NO enhanced antioxidant defense and activated plasma membrane (PM) H+-ATPase and decreased the accumulation of ROS induced by chilling stress. A pronounced increase in nitric oxide synthase (NOS) activity and NO release by exogenous ALA treatment was found in chilling-resistant DX plants exposed to chilling stress, while only a little increase was observed in chilling-sensitive ZD. Furthermore, inhibition of NO accumulation by PTIO or L-NNA blocked the protective effect of exogenous ALA, while both exogenous NO treatment and inhibition of endogenous NO accumulation did not induce ALA production. These results suggested that NO might be a downstream signal mediating ALA-induced chilling resistance in E. nutans. PMID:26151364

  6. Regulation of Cadmium-Induced Proteomic and Metabolic Changes by 5-Aminolevulinic Acid in Leaves of Brassica napus L.

    PubMed

    Ali, Basharat; Gill, Rafaqat A; Yang, Su; Gill, Muhammad B; Farooq, Muhammad A; Liu, Dan; Daud, Muhammad K; Ali, Shafaqat; Zhou, Weijun

    2015-01-01

    It is evident from previous reports that 5-aminolevulinic acid (ALA), like other known plant growth regulators, is effective in countering the injurious effects of heavy metal-stress in oilseed rape (Brassica napus L.). The present study was carried out to explore the capability of ALA to improve cadmium (Cd2+) tolerance in B. napus through physiological, molecular, and proteomic analytical approaches. Results showed that application of ALA helped the plants to adjust Cd2+-induced metabolic and photosynthetic fluorescence changes in the leaves of B. napus under Cd2+ stress. The data revealed that ALA treatment enhanced the gene expressions of antioxidant enzyme activities substantially and could increase the expression to a certain degree under Cd2+ stress conditions. In the present study, 34 protein spots were identified that differentially regulated due to Cd2+ and/or ALA treatments. Among them, 18 proteins were significantly regulated by ALA, including the proteins associated with stress related, carbohydrate metabolism, catalysis, dehydration of damaged protein, CO2 assimilation/photosynthesis and protein synthesis/regulation. From these 18 ALA-regulated proteins, 12 proteins were significantly down-regulated and 6 proteins were up-regulated. Interestingly, it was observed that ALA-induced the up-regulation of dihydrolipoyl dehydrogenase, light harvesting complex photo-system II subunit 6 and 30S ribosomal proteins in the presence of Cd2+ stress. In addition, it was also observed that ALA-induced the down-regulation in thioredoxin-like protein, 2, 3-bisphosphoglycerate, proteasome and thiamine thiazole synthase proteins under Cd2+ stress. Taken together, the present study sheds light on molecular mechanisms involved in ALA-induced Cd2+ tolerance in B. napus leaves and suggests a more active involvement of ALA in plant physiological processes than previously proposed.

  7. Regulation of Cadmium-Induced Proteomic and Metabolic Changes by 5-Aminolevulinic Acid in Leaves of Brassica napus L.

    PubMed Central

    Ali, Basharat; Gill, Rafaqat A.; Yang, Su; Gill, Muhammad B.; Farooq, Muhammad A.; Liu, Dan; Daud, Muhammad K.; Ali, Shafaqat; Zhou, Weijun

    2015-01-01

    It is evident from previous reports that 5-aminolevulinic acid (ALA), like other known plant growth regulators, is effective in countering the injurious effects of heavy metal-stress in oilseed rape (Brassica napus L.). The present study was carried out to explore the capability of ALA to improve cadmium (Cd2+) tolerance in B. napus through physiological, molecular, and proteomic analytical approaches. Results showed that application of ALA helped the plants to adjust Cd2+-induced metabolic and photosynthetic fluorescence changes in the leaves of B. napus under Cd2+ stress. The data revealed that ALA treatment enhanced the gene expressions of antioxidant enzyme activities substantially and could increase the expression to a certain degree under Cd2+ stress conditions. In the present study, 34 protein spots were identified that differentially regulated due to Cd2+ and/or ALA treatments. Among them, 18 proteins were significantly regulated by ALA, including the proteins associated with stress related, carbohydrate metabolism, catalysis, dehydration of damaged protein, CO2 assimilation/photosynthesis and protein synthesis/regulation. From these 18 ALA-regulated proteins, 12 proteins were significantly down-regulated and 6 proteins were up-regulated. Interestingly, it was observed that ALA-induced the up-regulation of dihydrolipoyl dehydrogenase, light harvesting complex photo-system II subunit 6 and 30S ribosomal proteins in the presence of Cd2+ stress. In addition, it was also observed that ALA-induced the down-regulation in thioredoxin-like protein, 2, 3-bisphosphoglycerate, proteasome and thiamine thiazole synthase proteins under Cd2+ stress. Taken together, the present study sheds light on molecular mechanisms involved in ALA-induced Cd2+ tolerance in B. napus leaves and suggests a more active involvement of ALA in plant physiological processes than previously proposed. PMID:25909456

  8. Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth

    PubMed Central

    Sim, Hyun Bo; Jang, Yong Hyun; Lee, Seok-Jong; Kim, Do Won; Yim, Soon-Ho

    2016-01-01

    Background Pattern hair loss is a very common problem. Although effective therapeutics for the treatment of pattern hair loss have been used, novel therapeutic modalities are still required to enhance hair growth. Objective We investigated the efficacy and safety of a complex (ALAVAX) of 5-aminolevulinic acid (5-ALA) and glycyl-histidyl-lysine (GHK) peptide for the treatment of pattern hair loss. Methods Forty-five patients with male pattern hair loss were treated with ALAVAX 100 mg/ml (group A), ALAVAX 50 mg/ml (group B) or placebo (group C) once a day for 6 months. Total hair count, hair length, hair thickness, patient's assessment and adverse events were evaluated at month 1, 3, and 6. Results An increase in hair count for 6 months was 52.6 (p<0.05) in group A, 71.5 (p<0.05) in group B, and 9.6 in group C. The ratio of changes in hair count between group B (2.38) and group C (1.21) at 6 months showed a statistically significant difference (p<0.05). The proportion above good satisfaction was higher in group A (26.7%) than in the other groups (group B: 14.3%, group C: 7.1%). There was no statistically significant difference in hair length and hair thickness among 3 groups at 6 months. There was no adverse event in 3 groups. Conclusion Our study showed that a complex of 5-ALA and GHK peptide may be considered as one of the complementary agents for the treatment of male pattern hair loss. PMID:27489425

  9. In Vivo Curative and Protective Potential of Orally Administered 5-Aminolevulinic Acid plus Ferrous Ion against Malaria

    PubMed Central

    Suzuki, Shigeo; Hikosaka, Kenji; Balogun, Emmanuel O.; Komatsuya, Keisuke; Niikura, Mamoru; Kobayashi, Fumie; Takahashi, Kiwamu; Tanaka, Tohru; Nakajima, Motowo

    2015-01-01

    5-Aminolevulinic acid (ALA) is a naturally occurring amino acid present in diverse organisms and a precursor of heme biosynthesis. ALA is commercially available as a component of cosmetics, dietary supplements, and pharmaceuticals for cancer diagnosis and therapy. Recent reports demonstrated that the combination of ALA and ferrous ion (Fe2+) inhibits the in vitro growth of the human malaria parasite Plasmodium falciparum. To further explore the potential application of ALA and ferrous ion as a combined antimalarial drug for treatment of human malaria, we conducted an in vivo efficacy evaluation. Female C57BL/6J mice were infected with the lethal strain of rodent malaria parasite Plasmodium yoelii 17XL and orally administered ALA plus sodium ferrous citrate (ALA/SFC) as a once-daily treatment. Parasitemia was monitored in the infected mice, and elimination of the parasites was confirmed using diagnostic PCR. Treatment of P. yoelii 17XL-infected mice with ALA/SFC provided curative efficacy in 60% of the mice treated with ALA/SFC at 600/300 mg/kg of body weight; no mice survived when treated with vehicle alone. Interestingly, the cured mice were protected from homologous rechallenge, even when reinfection was attempted more than 230 days after the initial recovery, indicating long-lasting resistance to reinfection with the same parasite. Moreover, parasite-specific antibodies against reported vaccine candidate antigens were found and persisted in the sera of the cured mice. These findings provide clear evidence that ALA/SFC is effective in an experimental animal model of malaria and may facilitate the development of a new class of antimalarial drug. PMID:26324278

  10. 5-Aminolevulinic acid ameliorates cadmium-induced morphological, biochemical, and ultrastructural changes in seedlings of oilseed rape.

    PubMed

    Ali, Basharat; Huang, C R; Qi, Z Y; Ali, Shafaqat; Daud, M K; Geng, X X; Liu, H B; Zhou, W J

    2013-10-01

    Due to its prolific growth, oilseed rape (Brassica napus L.) can be grown successfully for phytoremediation of cadmium (Cd)-contaminated soils. Nowadays, use of plant growth regulators against heavy metals stress is one of the major objectives of researchers. The present study evaluates the ameliorate effects of 5-aminolevulinic acid (ALA, 0, 0.4, 2, and 10 mg/l) on the growth of oilseed rape (B. napus L. cv. ZS 758) seedlings under Cd stress (0, 100, and 500 μM). Results have shown that Cd stress hampered the seedling growth by decreasing the radical and hypocotyls length, shoot and root biomass, chlorophyll content, and antioxidants enzymes. On the other hand, Cd stress increased the level of malondialdehyde (MDA) and production of H2O2 and accumulation of Cd in the shoots. The microscopic study of leaf mesophyll cells showed that toxicity of Cd totally destroyed the whole cell structure, and accumulation of Cd also appeared in micrographs. Application of ALA at lower dosage (2 mg/l) enhanced the seedling growth and biomass. The results showed that 2 mg/l ALA significantly improved chlorophyll content under Cd stress and decreased the level of Cd contents in shoots. Application of ALA reduced the MDA and H2O2 levels in the cotyledons. The antioxidants enzymes (ascorbate peroxidase, peroxidase, catalase, glutathione reductase, and superoxide dismutase) enhanced their activities significantly with the application of 2 mg/l ALA under Cd stress. This study also indicated that higher dosage of ALA (10 mg/l) imposed the negative effect on the growth of oilseed rape. Microscopic study showed that application of ALA alleviated the toxic effects of Cd in the mesophyll cell and improved the cell structure. Use of 2 mg/l ALA under 500 μM Cd was found to be more effective, and under this dosage, cell structure was clear, with obvious cell wall and cell membrane as well as a big nucleus, which was found with well-developed two or more nucleoli. Chloroplast was almost round

  11. Photodynamic therapy for epilepsy

    NASA Astrophysics Data System (ADS)

    Zusman, Edie; Sidhu, Manpreet; Coon, Valerie; Scott, Nicholas; Bisland, Stuart; Tsukamoto, Tara

    2006-02-01

    Epilepsy is surgically curable if the seizure focus can be localized and does not include areas of eloquent cortex. Because epileptic cells are indistinct from surrounding brain, resection typically includes normal tissue. Using the rat kindling model of epilepsy, we evaluated Photodynamic Therapy (PDT) as a super-selective lesioning technique. We present a series of pilot studies to evaluate: 1) Protoporphyrin IX (PpIX) fluorescence, 2) the efficacy of PDT to raise seizure thresholds, 3) the safety of PDT using behavioral studies, and 4) histologic results. Bipolar electrodes were chronically implanted into the cortex and animals received successive low-level stimulation generating seizures of increasing severity. Following 5-aminolevulinic acid (ALA) administration, fully kindled rats received electrical stimulation to induce a generalized seizure. Animals were irradiated with laser light focused onto a temporal craniectomy. Our results show: 1) an increase in PpIX fluorescence in the seizure group, 2) PDT treated animals failed to demonstrate seizure activity following repeat stimulation, 3) no statistically significant difference between treated and control animals were observed on behavioral tests, 4) histology showed pyknotic hippocampal pyramidal cells in the CA3 region without areas of obvious necrosis. In conclusion, this is the first report of heightened PpIX-mediated fluorescence in epileptic brain. The selective accumulation of PpIX with laser PDT may provide a less invasive and more precise technique for obliteration of epileptic foci. PDT warrants additional research to determine if this technique may augment or replace existing procedures for the surgical management of epilepsy.

  12. Expression of a hemA gene from Agrobacterium radiobacter in a rare codon optimizing Escherichia coli for improving 5-aminolevulinate production.

    PubMed

    Fu, Weiqi; Lin, Jianping; Cen, Peilin

    2010-01-01

    The 5-aminolevulinate (ALA) synthase gene (hemA) from Agrobacterium radiobacter zju-0121, which was cloned previously in our laboratory, contains several rare codons. To enhance the expression of this gene, Escherichia coli Rosetta(DE3), which is a rare codon optimizer strain, was picked out as the host to construct an efficient recombinant strain. Cell extracts of the recombinant E. coli were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under the appropriate conditions. The results indicated that the activity of ALA synthase expressed in Rosetta(DE3)/pET-28a(+)-hemA was about 20% higher than that in E. coli BL21(DE3). Then the effects of precursors (glycine and succinate) and glucose, which is an inhibitor for ALA dehydratase as well as the carbon sources for cell growth, on the production of 5-aminolevulinate were investigated. Based on an optimal fed-batch culture system described in our previous work, up to 6.5 g/l (50 mM) ALA was produced in a 15-l fermenter.

  13. Recent advances in the prevention and treatment of skin cancer using photodynamic therapy

    PubMed Central

    Zhao, Baozhong; He, Yu-Ying

    2011-01-01

    Photodynamic therapy (PDT) is a noninvasive procedure that involves a photosensitizing drug and its subsequent activation by light to produce reactive oxygen species that specifically destroy target cells. Recently, PDT has been widely used in treating non-melanoma skin malignancies, the most common cancer in the USA, with superior cosmetic outcomes compared with conventional therapies. The topical ‘photosensitizers’ commonly used are 5-aminolevulinic acid (ALA) and its esterified derivative methyl 5-aminolevulinate, which are precursors of the endogenous photosensitizer protoporphyrin IX. After treatment with ALA or methyl 5-aminolevulinate, protoporphyrin IX preferentially accumulates in the lesion area of various skin diseases, which allows not only PDT treatment but also fluorescence diagnosis with ALA-induced porphyrins. Susceptible lesions include various forms of non-melanoma skin cancer such as actinic keratosis, basal cell carcinoma and squamous cell carcinoma. The most recent and promising developments in PDT include the discovery of new photosensitizers, the exploitation of new drug delivery systems and the combination of other modalities, which will all contribute to increasing PDT therapeutic efficacy and improving outcome. This article summarizes the main principles of PDT and its current clinical use in the management of non-melanoma skin cancers, as well as recent developments and possible future research directions. PMID:21080805

  14. Photodynamic therapy of acne vulgaris.

    NASA Astrophysics Data System (ADS)

    Ershova, Ekaterina Y.; Karimova, Lubov N.; Kharnas, Sergey S.; Kuzmin, Sergey G.; Loschenov, Victor B.

    2003-06-01

    Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) was tested for the treatment of acne vulgaris. Patients with acne were treated with ALA plus red light. Ten percent water solution of ALA was applied with 1,5-2 h occlusion and then 18-45 J/cm2 630 nm light was given. Bacterial endogenous porphyrins fluorescence also was used for acne therapy. Treatment control and diagnostics was realized by fluorescence spectra and fluorescence image. Light sources and diagnostic systems were used: semiconductor laser (λ=630 nm, Pmax=1W), (LPhT-630-01-BIOSPEC); LED system for PDT and diagnostics with fluorescent imager (λ=635 nm, P=2W, p=50 mW/cm2), (UFPh-630-01-BIOSPEC); high sensitivity CCD video camera with narrow-band wavelength filter (central wavelength 630 nm); laser electronic spectrum analyzer for fluorescent diagnostics and photodynamic therapy monitoring (LESA-01-BIOSPEC). Protoporphyrin IX (PP IX) and endogenous porphyrins concentrations were measured by fluorescence at wavelength, correspondingly, 700 nm and 650 nm. It was shown that topical ALA is converted into PP IX in hair follicles, sebaceous glands and acne scars. The amount of resulting PP IX is sufficient for effective PDT. There was good clinical response and considerable clearance of acne lesion. ALA-PDT also had good cosmetic effect in treatment acne scars. PDT with ALA and red light assist in opening corked pores, destroying Propionibacterium acnes and decreasing sebum secretion. PDT treatment associated with several adverse effects: oedema and/or erytema for 3-5 days after PDT, epidermal exfoliation from 5th to 10th day and slight pigmentation during 1 month after PDT. ALA-PDT is effective for acne and can be used despite several side effects.

  15. Topical photodynamic therapy with 5-ALA in the treatment of arsenic-induced skin tumors

    NASA Astrophysics Data System (ADS)

    Karrer, Sigrid; Szeimies, Rolf-Markus; Landthaler, Michael

    1995-03-01

    A case of a 62-year-old woman suffering from psoriasis who was treated orally with arsenic 25 years ago is reported. The cumulative dose of arsenic trioxide was 800 mg. Since 10 years ago arsenic keratoses, basal cell carcinomas, Bowen's disease and invasive squamous cell carcinomas mainly on her hands and feet have developed, skin changes were clearly a sequence of arsenic therapy. Control of disease was poor, her right little finger had to be amputated. Topical photodynamic therapy with 5-aminolevulinic acid was performed on her right hand. Clinical and histological examinations 6 months after treatment showed an excellent cosmetic result with no signs of tumor residue.

  16. Generation of reactive oxygen species from 5-aminolevulinic acid and Glutamate in cooperation with excited CdSe/ZnS QDs

    NASA Astrophysics Data System (ADS)

    Duong, Hong Dinh; Lee, Jee Won; Rhee, Jong Il

    2014-08-01

    CdSe/ZnS quantum dots (QDs) can be joined in the reductive pathway involving the electron transfer to an acceptor or in the oxidative pathway involving the hole transfer to a donor. They were exploited in the oxidation reactions of 5-aminolevulinic acid (ALA) and glutamate (GLU) for the generation of reactive oxygen species (ROS) such as hydroxyl radical (HO●) and superoxide anion (O2 ● -). Fast and highly efficient oxidation reactions of ALA to produce HO● and of GLU to produce O2 ●- were observed in the cooperation of mercaptopropionic acid (MPA)-capped CdSe/ZnS QDs under LED irradiation. Fluorescence spectroscopy and electron spin resonance (ESR) spectroscopy were used to evaluate the generation of different forms of ROS. Confocal fluorescent microscopic images of the size and morphology of HeLa cells confirmed the ROS generation from ALA or GLU in cooperation with CdSe/ZnS QDs under LED irradiation.

  17. Catalytically active alkaline molten globular enzyme: Effect of pH and temperature on the structural integrity of 5-aminolevulinate synthase.

    PubMed

    Stojanovski, Bosko M; Breydo, Leonid; Hunter, Gregory A; Uversky, Vladimir N; Ferreira, Gloria C

    2014-12-01

    5-Aminolevulinate synthase (ALAS), a pyridoxal-5'phosphate (PLP)-dependent enzyme, catalyzes the first step of heme biosynthesis in mammals. Circular dichroism (CD) and fluorescence spectroscopies were used to examine the effects of pH (1.0-3.0 and 7.5-10.5) and temperature (20 and 37°C) on the structural integrity of ALAS. The secondary structure, as deduced from far-UV CD, is mostly resilient to pH and temperature changes. Partial unfolding was observed at pH2.0, but further decreasing pH resulted in acid-induced refolding of the secondary structure to nearly native levels. The tertiary structure rigidity, monitored by near-UV CD, is lost under acidic and specific alkaline conditions (pH10.5 and pH9.5/37°C), where ALAS populates a molten globule state. As the enzyme becomes less structured with increased alkalinity, the chiral environment of the internal aldimine is also modified, with a shift from a 420nm to 330nm dichroic band. Under acidic conditions, the PLP cofactor dissociates from ALAS. Reaction with 8-anilino-1-naphthalenesulfonic acid corroborates increased exposure of hydrophobic clusters in the alkaline and acidic molten globules, although the reaction is more pronounced with the latter. Furthermore, quenching the intrinsic fluorescence of ALAS with acrylamide at pH1.0 and 9.5 yielded subtly different dynamic quenching constants. The alkaline molten globule state of ALAS is catalytically active (pH9.5/37°C), although the kcat value is significantly decreased. Finally, the binding of 5-aminolevulinate restricts conformational fluctuations in the alkaline molten globule. Overall, our findings prove how the structural plasticity of ALAS contributes to reaching a functional enzyme.

  18. Catalytically active alkaline molten globular enzyme: Effect of pH and temperature on the structural integrity of 5-aminolevulinate synthase.

    PubMed

    Stojanovski, Bosko M; Breydo, Leonid; Hunter, Gregory A; Uversky, Vladimir N; Ferreira, Gloria C

    2014-12-01

    5-Aminolevulinate synthase (ALAS), a pyridoxal-5'phosphate (PLP)-dependent enzyme, catalyzes the first step of heme biosynthesis in mammals. Circular dichroism (CD) and fluorescence spectroscopies were used to examine the effects of pH (1.0-3.0 and 7.5-10.5) and temperature (20 and 37°C) on the structural integrity of ALAS. The secondary structure, as deduced from far-UV CD, is mostly resilient to pH and temperature changes. Partial unfolding was observed at pH2.0, but further decreasing pH resulted in acid-induced refolding of the secondary structure to nearly native levels. The tertiary structure rigidity, monitored by near-UV CD, is lost under acidic and specific alkaline conditions (pH10.5 and pH9.5/37°C), where ALAS populates a molten globule state. As the enzyme becomes less structured with increased alkalinity, the chiral environment of the internal aldimine is also modified, with a shift from a 420nm to 330nm dichroic band. Under acidic conditions, the PLP cofactor dissociates from ALAS. Reaction with 8-anilino-1-naphthalenesulfonic acid corroborates increased exposure of hydrophobic clusters in the alkaline and acidic molten globules, although the reaction is more pronounced with the latter. Furthermore, quenching the intrinsic fluorescence of ALAS with acrylamide at pH1.0 and 9.5 yielded subtly different dynamic quenching constants. The alkaline molten globule state of ALAS is catalytically active (pH9.5/37°C), although the kcat value is significantly decreased. Finally, the binding of 5-aminolevulinate restricts conformational fluctuations in the alkaline molten globule. Overall, our findings prove how the structural plasticity of ALAS contributes to reaching a functional enzyme. PMID:25240868

  19. Evaluating the efficacy and safety of a novel endoscopic fluorescence imaging modality using oral 5-aminolevulinic acid for colorectal tumors

    PubMed Central

    Tsuruki, Eriko So; Saito, Yutaka; Abe, Seiichiro; Takamaru, Hiroyuki; Yamada, Masayoshi; Sakamoto, Taku; Nakajima, Takeshi; Matsuda, Takahisa; Sekine, Shigeki; Taniguchi, Hirokazu

    2016-01-01

    Background and study aims: Five-aminolevulinic acid (5-ALA) is being increasingly used for photodynamic diagnosis and therapy of various types of tumors including brain, urologic, and other neoplasias. The use of 5-ALA to treat Barrett’s carcinomas has been documented, but its clinical effectiveness for diagnosis of gastrointestinal tumors, particularly early cancers, remains unknown. Patients and methods: The aim of our feasibility study was to evaluate the visibility of colorectal tumors using endoscopic fluorescence imaging (EFI) after oral administration of 5-ALA. The lesions identified by direct visualization and by the spectrums produced using EFI modality with 5-ALA were compared to the clinicopathologic features of resected specimens. Results: Twenty-three patients with a total of 27 known colorectal lesions were enrolled in the study. The median tumor size was 30 mm (range 10 – 75). Eleven of the lesions were flat or depressed lesions and 16 were sessile. Red fluorescence was observed in 22 out of 27 lesions. Red fluorescence was negative in 4 out of 11 flat or depressed lesions. In comparison with histopathologic findings, the rates of red fluorescence visibility were 62.5 % in low-grade intraepithelial neoplasia, 77.8 % in high-grade neoplasia, and 100 % in submucosal carcinoma. Red fluorescence visibility increased with the degree of dysplasia. There were no significant adverse events identified in this study. Conclusions: This feasibility study using EFI with 5-ALA demonstrated high visibility of superficial colorectal neoplasia. EFI with 5-ALA appears to be a novel, safe technique for improving real-time colorectal tumor imaging. PMID:26793782

  20. Photodynamic Therapy for Non-Melanoma Skin Cancers

    PubMed Central

    Cohen, Diana K.; Lee, Peter K.

    2016-01-01

    Non-melanoma skin cancer (NMSC) is traditionally treated with surgical excision. Non-surgical methods such as cryotherapy and topical chemotherapeutics, amongst other treatments, are other options. Actinic keratosis (AKs) are considered precancerous lesions that eventually may progress to squamous cell carcinoma (SCC). Photodynamic therapy (PDT) offers an effective treatment for AKs, and is also effective for superficial basal cell carcinoma (BCC). Nodular BCC and Bowen’s disease (SCC in situ) have shown acceptable response rates with PDT, although recurrence rates are higher for these two NMSC subtypes. Methylaminolevulinate (MAL) PDT is a more effective treatment option than 5-aminolevulinic acid (ALA) PDT for nodular BCC. Several studies have shown that PDT results in superior cosmetic outcomes compared to surgical treatment. PDT is overall well-tolerated, with pain being the most common side effect. PMID:27782043

  1. Photodynamic therapy (ALA-PDT) in the treatment of pathological states of the cornea

    NASA Astrophysics Data System (ADS)

    Switka-Wieclawska, Iwona; Kecik, Tadeusz; Kwasny, Miroslaw; Graczyk, Alfreda

    2003-10-01

    Each year an increasing amount of research is published on the use of photodynamic therapy in medicine. The most recent research has focused mostly on the use of photosensitizer called vertoporphyrin (Visudyne) is the treatment of subretinal neovascularization in age-related macular degeneration (AMD) or myopia, following a substantial amount of ophthalmology research mostly experimental on the application of the method in diagnosis and treatment of some eye tumors. In the Department of Ophthalmology of Polish Medical University in Warsaw, PDT was used as supplementary method in a selected group of patients with chronic virus ulcer of the cornea and keratopathies. During the treatment 5-aminolevulinic acid (5-ALA) was applied in ointment form as a photosensitizer activated with light wave of 633 nm. It appears, on the basis of the results obtained, that photodynamic therapy (ALA-PDT) may become in the future a valuable supplement to the methods being used at the present treating pathological states of the cornea.

  2. A Pilot Cost-Effectiveness Analysis of Treatments in Newly Diagnosed High-Grade Gliomas: The Example of 5-Aminolevulinic Acid Compared With White-Light Surgery

    PubMed Central

    Alves, Marta; Castel-Branco, Marta; Stummer, Walter

    2015-01-01

    BACKGROUND: High-grade gliomas are aggressive, incurable tumors characterized by extensive diffuse invasion of the normal brain parenchyma. Novel therapies at best prolong survival; their costs are formidable and benefit is marginal. Economic restrictions thus require knowledge of the cost-effectiveness of treatments. Here, we show the cost-effectiveness of enhanced resections in malignant glioma surgery using a well-characterized tool for intraoperative tumor visualization, 5-aminolevulinic acid (5-ALA). OBJECTIVE: To evaluate the cost-effectiveness of 5-ALA fluorescence-guided neurosurgery compared with white-light surgery in adult patients with newly diagnosed high-grade glioma, adopting the perspective of the Portuguese National Health Service. METHODS: We used a Markov model (cohort simulation). Transition probabilities were estimated with the use of data from 1 randomized clinical trial and 1 noninterventional prospective study. Utility values and resource use were obtained from published literature and expert opinion. Unit costs were taken from official Portuguese reimbursement lists (2012 values). The health outcomes considered were quality-adjusted life-years, life-years, and progression-free life-years. Extensive 1-way and probabilistic sensitivity analyses were performed. RESULTS: The incremental cost-effectiveness ratios are below €10 000 in all evaluated outcomes, being around €9100 per quality-adjusted life-year gained, €6700 per life-year gained, and €8800 per progression-free life-year gained. The probability of 5-ALA fluorescence-guided surgery cost-effectiveness at a threshold of €20000 is 96.0% for quality-adjusted life-year, 99.6% for life-year, and 98.8% for progression-free life-year. CONCLUSION: 5-ALA fluorescence-guided surgery appears to be cost-effective in newly diagnosed high-grade gliomas compared with white-light surgery. This example demonstrates cost-effectiveness analyses for malignant glioma surgery to be feasible on

  3. Alleviation of lead toxicity by 5-aminolevulinic acid is related to elevated growth, photosynthesis, and suppressed ultrastructural damages in oilseed rape.

    PubMed

    Tian, Tian; Ali, Basharat; Qin, Yebo; Malik, Zaffar; Gill, Rafaqat A; Ali, Shafaqat; Zhou, Weijun

    2014-01-01

    Lead (Pb) is a widely spread pollutant and leads to diverse morphological and structural changes in the plants. In this study, alleviating role of 5-aminolevulinic acid (ALA) in oilseed rape (Brassica napus L.) was investigated with or without foliar application of ALA (25 mg L(-1)) in hydroponic environment under different Pb levels (0, 100, and 400 µM). Outcomes stated that plant morphology and photosynthetic attributes were reduced under the application of Pb alone. However, ALA application significantly increased the plant growth and photosynthetic parameters under Pb toxicity. Moreover, ALA also lowered the Pb concentration in shoots and roots under Pb toxicity. The microscopic studies depicted that exogenously applied ALA ameliorated the Pb stress and significantly improved the cell ultrastructures. After application of ALA under Pb stress, mesophyll cell had well-developed nucleus and chloroplast having a number of starch granules. Moreover, micrographs illustrated that root tip cell contained well-developed nucleus, a number of mitochondria, and golgi bodies. These results proposed that under 15-day Pb-induced stress, ALA improved the plant growth, chlorophyll content, photosynthetic parameters, and ultrastructural modifications in leaf mesophyll and root tip cells of the B. napus plants.

  4. Mechanism of rat osteosarcoma cell apoptosis induced by a combination of low-intensity ultrasound and 5-aminolevulinic acid in vitro.

    PubMed

    Li, Y N; Zhou, Q; Yang, B; Hu, Z; Wang, J H; Li, Q S; Cao, W W

    2015-01-01

    We investigated the killing effect of low-intensity ultrasound combined with 5-aminolevulinic acid (5-ALA) on the rat osteosarcoma cell line UMR-106. Logarithmic-phase UMR-106 cells were divided into a control group, ultrasound group and 5-ALA group. The cell apoptotic rate, production of reactive oxygen species, and the change in mitochondrial membrane potential were analyzed by flow cytometry; ultrastructural changes were observed by transmission electron microscopy. Using low-intensity ultrasound at 1.0 MHz and 2.0 W/cm(2) plus 5-ALA at a concentration of 2 mM, the apoptotic rate of the sonodynamic therapy group was 27.2 ± 3.4% which was significantly higher than that of the control group, ultrasound group, and 5-ALA group (P < 0.05). The production of reactive oxygen species was 32.6 ± 2.2% and the decrease in mitochondrial membrane potential was 39.5 ± 2.5%. The 33342 staining showed nuclear condensation and fragmentation in the ultrasound group and 5-ALA group. Structural changes in the cell membrane, mitochondria, Golgi apparatus, and other organelles observed by transmission electron microscopy included formation of apoptotic bodies. The killing effect of low-intensity ultrasound combined with 5-ALA on UMR-106 cells was significant. Cell apoptosis played a vital role in the killing effect, and the mitochondria pathway contributed to the apoptosis of UMR-106 cells. PMID:26345893

  5. The Safety and Tolerability of 5-Aminolevulinic Acid Phosphate with Sodium Ferrous Citrate in Patients with Type 2 Diabetes Mellitus in Bahrain

    PubMed Central

    Al-Saber, Feryal; Aldosari, Waleed; Alselaiti, Mariam; Khalfan, Hesham; Kaladari, Ahmed; Khan, Ghulam; Harb, George; Rehani, Riyadh; Kudo, Sizuka; Koda, Aya; Tanaka, Tohru

    2016-01-01

    Type 2 diabetes mellitus is prevalent especially in Gulf countries and poses serious long-term risks to patients. A multifaceted treatment approach can include nutritional supplements with antioxidant properties such as 5-aminolevulinic acid (5-ALA) with sodium ferrous citrate (SFC). This prospective, randomized, single-blind, placebo-controlled, dose escalating pilot clinical trial assessed the safety of 5-ALA with SFC at doses up to 200 mg 5-ALA/229.42 mg SFC per day in patients living in Bahrain with type 2 diabetes mellitus that was uncontrolled despite the use of one or more antidiabetic drugs. Fifty-three patients (n = 53) from 3 sites at one center were enrolled by Dr. Feryal (Site #01), Dr. Hesham (Site #02), and Dr. Waleed (Site #03) (n = 35, 5-ALA-SFC; n = 18, placebo). There was no significant difference in incidence of adverse events reported, and the most frequent events reported were gastrointestinal in nature, consistent with the known safety profile of 5-ALA in patients with diabetes. No significant changes in laboratory values and no difference in hypoglycemia between patients receiving 5-ALA and placebo were noted. Overall, the current results support that use of 5-ALA-SFC up to 200 mg per day taken as 2 divided doses is safe in patients taking concomitant oral antidiabetic medications and may offer benefits in the diabetic population. This trial is registered with ClinicalTrials.gov NCT02481141. PMID:27738640

  6. Synergism of herbicide toxicity by 5-aminolevulinic acid is related to physiological and ultra-structural disorders in crickweed (Malachium aquaticum L.).

    PubMed

    Xu, Ling; Zhang, Wenfang; Ali, Basharat; Islam, Faisal; Zhu, Jinwen; Zhou, Weijun

    2015-11-01

    Selection of effective herbicides to control weeds has been one of the major objectives of scientists. This study determines the differential tolerance or susceptibility of crickweed (Malachium aquaticum L.) to various concentration combinations of 5-aminolevulinic acid (ALA) (1, 10 and 100mg/L) and propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273) (100, 200, and 500mg/L). ALA was applied as pre- and post-treatment alone or in combination with ZJ0273. Results showed that ZJ0273 stress alone imposed negative effects on M. aquaticum seedling's growth, net photosynthetic rates and SPAD values, and the rate of decline was consistently increased with the increase in ZJ0273 concentration. The ZJ0273 treatment showed a gradual decrease in the activities of antioxidant enzymes peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX), and increase in the accumulation of malondialdehyde (MDA). Changes in chloroplast swelling, increased number of plastoglobuli, disruption of thylakoid, disintegrated mitochondria and turbid nucleoplasm were noticed. Moreover, SDS-PAGE analysis of total proteins revealed that herbicide stress in the leaves was associated with the decrease or disappearance of some protein bands. Further, two-dimensional gel electrophoresis (2-DE) results showed that proteins in different spots were classified into three types for M. aquaticum. These results indicate that the combined treatment of ALA and ZJ0273 synergizes the herbicide toxicity which is different from its independent effects on M. aquaticum and thus, could improve weed control efficacy. PMID:26615151

  7. Alleviation of Lead Toxicity by 5-Aminolevulinic Acid Is Related to Elevated Growth, Photosynthesis, and Suppressed Ultrastructural Damages in Oilseed Rape

    PubMed Central

    Tian, Tian; Qin, Yebo; Gill, Rafaqat A.; Ali, Shafaqat

    2014-01-01

    Lead (Pb) is a widely spread pollutant and leads to diverse morphological and structural changes in the plants. In this study, alleviating role of 5-aminolevulinic acid (ALA) in oilseed rape (Brassica napus L.) was investigated with or without foliar application of ALA (25 mg L−1) in hydroponic environment under different Pb levels (0, 100, and 400 µM). Outcomes stated that plant morphology and photosynthetic attributes were reduced under the application of Pb alone. However, ALA application significantly increased the plant growth and photosynthetic parameters under Pb toxicity. Moreover, ALA also lowered the Pb concentration in shoots and roots under Pb toxicity. The microscopic studies depicted that exogenously applied ALA ameliorated the Pb stress and significantly improved the cell ultrastructures. After application of ALA under Pb stress, mesophyll cell had well-developed nucleus and chloroplast having a number of starch granules. Moreover, micrographs illustrated that root tip cell contained well-developed nucleus, a number of mitochondria, and golgi bodies. These results proposed that under 15-day Pb-induced stress, ALA improved the plant growth, chlorophyll content, photosynthetic parameters, and ultrastructural modifications in leaf mesophyll and root tip cells of the B. napus plants. PMID:24683549

  8. Photodynamic therapy for cancer

    MedlinePlus

    ... Cancer of the esophagus-photodynamic; Esophageal cancer-photodynamic; Lung cancer-photodynamic ... the light at the cancer cells. PDT treats cancer in the: Lungs, using a bronchoscope Esophagus, using upper endoscopy Doctors ...

  9. The use of photodynamic therapy in dermatology.

    PubMed

    Babilas, P; Szeimies, R M

    2010-10-01

    In dermatology, topical photodynamic therapy (PDT) is a well established treatment modality which has mainly shown to be effective for dermato-oncologic conditions like actinic keratosis, Bowen's disease, in-situ squamous cell carcinoma and superficial basal cell carcinoma. However, a therapeutical benefit of PDT is also evident for inflammatory dermatoses like localized scleroderma, acne vulgaris and granuloma annulare as well as for aesthetic indications like photo aged skin or sebaceous gland hyperplasia. Recent work has been focused on the development and evaluation of topical photosensitizers like the hem precursor 5-aminolevulinic acid or its methyl ester inducing photosensitizing porphyrins. These drugs do not induce strong generalized cutaneous photosensitization like the systemically applied porphyrins or their derivatives. For dermatological purposes incoherent lamps or LED arrays can be used for light activation. Depending on the applied light dose and the concentration of the photosensitizer either cytotoxic effects resulting in tumor destruction or immunomodulatory effects improving the inflammatory conditions occur. Treating superficial oncologic lesions (tumor thickness < 2-3 mm) cure rates achieved by PDT are equal to the cure rates of the respective standard therapeutic procedure. The benefits of PDT are the low level of invasiveness and the excellent cosmetic results after treatment. PMID:20930696

  10. 5-Aminolevulinic acid combined with ferrous iron induces carbon monoxide generation in mouse kidneys and protects from renal ischemia-reperfusion injury.

    PubMed

    Hou, Jiangang; Cai, Songjie; Kitajima, Yuya; Fujino, Masayuki; Ito, Hidenori; Takahashi, Kiwamu; Abe, Fuminori; Tanaka, Tohru; Ding, Qiang; Li, Xiao-Kang

    2013-10-15

    Renal ischemia reperfusion injury (IRI) is a major factor responsible for acute renal failure. An intermediate in heme synthesis, 5-aminolevulinic acid (5-ALA) is fundamental in aerobic energy metabolism. Heme oxygenase (HO)-1 cleaves heme to form biliverdin, carbon monoxide (CO), and iron (Fe(2+)), which is used with 5-ALA. In the present study, we investigated the role of 5-ALA in the attenuation of acute renal IRI using a mouse model. Male Balb/c mice received 30 mg/kg 5-ALA with Fe(2+) 48, 24, and 2 h before IRI and were subsequently subjected to bilateral renal pedicle occlusion for 45 min. The endogenous CO concentration of the kidneys from the mice administered 5-ALA/Fe(2+) increased significantly, and the peak concentrations of serum creatinine and blood urea nitrogen decreased. 5-ALA/Fe(2+) treatments significantly decreased the tubular damage and number of apoptotic cells. IRI-induced renal thiobarbituric acid-reactive substance levels were also significantly decreased in the 5-ALA/Fe(2+) group. Furthermore, mRNA expression of HO-1, TNF-α, and interferon-γ was significantly increased after IRI. Levels of HO-1 were increased and levels of TNF-α and interferon-γ were decreased in the 5-ALA/Fe(2+)-pretreated renal parenchyma after IRI. F4/80 staining showed reduced macrophage infiltration, and TUNEL staining revealed that there were fewer interstitial apoptotic cells. These findings suggest that 5-ALA/Fe(2+) can protect the kidneys against IRI by reducing macrophage infiltration and decreasing renal cell apoptosis via the generation of CO.

  11. Effects of exogenous 5-aminolevulinic acid on photosynthesis, stomatal conductance, transpiration rate, and PIP gene expression of tomato seedlings subject to salinity stress.

    PubMed

    Zhao, Y Y; Yan, F; Hu, L P; Zhou, X T; Zou, Z R; Cui, L R

    2015-01-01

    The effects of exogenous 5-aminolevulinic acid (ALA) on photosynthesis, plant growth, and the expression of two aquaporin genes in tomato seedlings under control and salinity conditions were investigated. Exogenous ALA application significantly improved net photosynthetic rate (Pn), total chlorophyll content, and plant biomass accumulation of tomato seedlings under salinity stress. As revealed by real-time PCR analyses, after treatment with ALA alone, expression of both LePIP1 and LePIP2 in the two tomato cultivars was up-regulated at 2 h and subsequently decreased to normal levels. Under salinity stress, transcript levels of LePIP1 in both leaves and roots of salt-sensitive cultivars (cv. Zhongza No.9) increased significantly and were considerably higher than in cultivars exposed to ALA alone. In contrast, the expression levels of LePIP1 and LePIP2 in cvs. Jinpeng No.1 cultivars were slightly lower under salinity stress than under ALA treatment. In addition, transcript levels of both LePIP1 and LePIP2 in the roots of Jinpeng No. 1 cultivars were considerably lower than those in the roots of Zhongza No. 9 cultivars under salinity stress, regardless of ALA supplementation, implying that Jinpeng No. 1 cultivars had a better capacity to maintain membrane intrinsic protein stability. Further, ALA application distinctly counteracted the up- or down-regulation of LePIP1 and LePIP2 in both cultivars under salinity stress, in accordance with the improvements instomatal conductance, transpiration rate, and Pn of tomato leaves. The results presented here indicate that ALA controls aquaporin expression, thus, presumably ALA regulates water homeostasis and enhances salt tolerance of tomato seedlings. PMID:26125845

  12. Impact of 5-aminolevulinic acid with iron supplementation on exercise efficiency and home-based walking training achievement in older women.

    PubMed

    Masuki, Shizue; Morita, Atsumi; Kamijo, Yoshi-ichiro; Ikegawa, Shigeki; Kataoka, Yufuko; Ogawa, Yu; Sumiyoshi, Eri; Takahashi, Kiwamu; Tanaka, Tohru; Nakajima, Motowo; Nose, Hiroshi

    2016-01-01

    A reduction in exercise efficiency with aging limits daily living activities. We examined whether 5-aminolevulinic acid (ALA) with sodium ferrous citrate (SFC) increased exercise efficiency and voluntary achievement of interval walking training (IWT) in older women. Ten women [65 ± 3(SD) yr] who had performed IWT for >12 mo and were currently performing IWT participated in this study. The study was conducted in a placebo-controlled, double-blind crossover design. All subjects underwent two trials for 7 days each in which they performed IWT with ALA+SFC (100 and 115 mg/day, respectively) or placebo supplement intake (CNT), intermittently with a 2-wk washout period. Before and after each trial, subjects underwent a graded cycling test at 27.0 °C atmospheric temperature and 50% relative humidity, and oxygen consumption rate, carbon dioxide production rate, and lactate concentration in plasma were measured. Furthermore, for the first 6 days of each trial, exercise intensity for IWT was measured by accelerometry. We found that, in the ALA+SFC trial, oxygen consumption rate and carbon dioxide production rate during graded cycling decreased by 12% (P < 0.001) and 11% (P = 0.001) at every workload, respectively, accompanied by a 16% reduction in lactate concentration in plasma (P < 0.001), although all remained unchanged in the CNT trial (P > 0.2). All of the reductions were significantly greater in the ALA+SFC than the CNT trial (P < 0.05). Furthermore, the training days, impulse, and time at fast walking were 42% (P = 0.028), 102% (P = 0.027), and 69% (P = 0.039) higher during the ALA+SFC than the CNT intake period, respectively. Thus ALA+SFC supplementation augmented exercise efficiency and thereby improved IWT achievement in older women.

  13. Short Communication: Molecular cloning and expression pattern of the porcine 5-aminolevulinate synthase 1 (ALAS1) gene and its association with reproductive traits.

    PubMed

    Liu, L Q; Li, F E; Deng, C Y

    2016-01-01

    5-Aminolevulinate synthase 1 (ALAS1) is the first enzyme in the heme biosynthetic pathway and is upregulated in follicular tissue during the early stages of ovulation. In this study, we isolated the complete coding sequence of the porcine ALAS1 gene and its 2-9 intron sequence, identified a single nucleotide polymorphism (SNP; T/C) in intron 9, and developed a PCR-MspI-restriction fragment length polymorphism genotyping assay. Association of the SNP with litter size was assessed in two populations [purebred Large White and the experimental synthetic (DIV) line]. Statistical analysis demonstrated that for total number of piglets born (TNB) in all parities, pigs with the CC genotype had an additional 0.68 and 0.74 piglets compared to the TC and TT animals (P < 0.05) in the DIV line, respectively. Purebred Large White sows inheriting the CC and TC genotypes gave birth to an additional 0.96 and 0.70 piglets compared to the TT animals (P < 0.05) in all parities, respectively. In addition, for TNB in all parities, a significant additive effect of 0.48 ± 0.23 and 0.37 ± 0.17 piglets/ litter was detected in sows of both populations (P < 0.05), respectively. The highest levels of ALAS1 gene expression were observed in isolated ovarian granulosa cells 2 and 12 h after stimulation with pregnant mare serum gonadotropin human chorionic gonadotropin, which represents the time of follicular development and ovulation, respectively. Therefore, the ALAS1 gene was significantly associated with litter size in two populations and could be a useful molecular marker for the selection of increasing litter size in pigs. PMID:26910002

  14. Impact of 5-aminolevulinic acid with iron supplementation on exercise efficiency and home-based walking training achievement in older women

    PubMed Central

    Masuki, Shizue; Morita, Atsumi; Kamijo, Yoshi-ichiro; Ikegawa, Shigeki; Kataoka, Yufuko; Ogawa, Yu; Sumiyoshi, Eri; Takahashi, Kiwamu; Tanaka, Tohru; Nakajima, Motowo

    2015-01-01

    A reduction in exercise efficiency with aging limits daily living activities. We examined whether 5-aminolevulinic acid (ALA) with sodium ferrous citrate (SFC) increased exercise efficiency and voluntary achievement of interval walking training (IWT) in older women. Ten women [65 ± 3(SD) yr] who had performed IWT for >12 mo and were currently performing IWT participated in this study. The study was conducted in a placebo-controlled, double-blind crossover design. All subjects underwent two trials for 7 days each in which they performed IWT with ALA+SFC (100 and 115 mg/day, respectively) or placebo supplement intake (CNT), intermittently with a 2-wk washout period. Before and after each trial, subjects underwent a graded cycling test at 27.0°C atmospheric temperature and 50% relative humidity, and oxygen consumption rate, carbon dioxide production rate, and lactate concentration in plasma were measured. Furthermore, for the first 6 days of each trial, exercise intensity for IWT was measured by accelerometry. We found that, in the ALA+SFC trial, oxygen consumption rate and carbon dioxide production rate during graded cycling decreased by 12% (P < 0.001) and 11% (P = 0.001) at every workload, respectively, accompanied by a 16% reduction in lactate concentration in plasma (P < 0.001), although all remained unchanged in the CNT trial (P > 0.2). All of the reductions were significantly greater in the ALA+SFC than the CNT trial (P < 0.05). Furthermore, the training days, impulse, and time at fast walking were 42% (P = 0.028), 102% (P = 0.027), and 69% (P = 0.039) higher during the ALA+SFC than the CNT intake period, respectively. Thus ALA+SFC supplementation augmented exercise efficiency and thereby improved IWT achievement in older women. PMID:26514619

  15. 5-Aminolevulinic Acid Protects against Cisplatin-Induced Nephrotoxicity without Compromising the Anticancer Efficiency of Cisplatin in Rats In Vitro and In Vivo

    PubMed Central

    Matsumoto, Tatsuki; Ishihara, Masayuki; Hamada, Kazu; Shimamura, Yoshiko; Ogata, Koji; Inoue, Kosuke; Taniguchi, Yoshinori; Horino, Taro; Karashima, Takashi; Tamura, Kenji; Fukuhara, Hideo; Fujimoto, Shimpei; Tsuda, Masayuki; Shuin, Taro

    2013-01-01

    Background/Aims Nephrotoxicity is a frequent and major limitation in cisplatin (CDDP)-based chemotherapy. 5-Aminolevulinic acid (ALA) is widely distributed in animal cells, and it is a precursor of tetrapyrole compounds such as heme that is fundamentally important in aerobic energy metabolism. The aim of this study is to evaluate the protective role of ALA in CDDP-induced acute kidney injury (AKI). Method We used CDDP-induced AKI rat model and cultured renal tubular cells (NRK-52E). We divided four groups of rats: control, CDDP only, CDDP + ALA(post);(ALA 10 mg/kg + Fe in drinking water) after CDDP, CDDP + ALA(pre & post). Result CDDP increased Cr up to 6.5 mg/dl, BUN up to 230 mg/dl, and ALA significantly reduced these changes. ALA ameliorates CDDP-induced morphological renal damages, and reduced tubular apoptosis evaluated by TUNEL staining and cleaved caspase 3. Protein and mRNA levels of ATP5α, complex(COX) IV, UCP2, PGC-1α in renal tissue were significantly decreased by CDDP, and ALA ameliorates reduction of these enzymes. In contrast, Heme Oxigenase (HO)-1 level is induced by CDDP treatment, and ALA treatment further up-regulates HO-1 levels. In NRK-52E cells, the CDDP-induced reduction of protein and mRNA levels of mitochondrial enzymes was significantly recovered by ALA + Fe. CDDP-induced apoptosis were ameliorated by ALA + Fe treatment. Furthermore, we evaluated the size of transplantated bladder carcinoma to the rat skin, and ALA did not change the anti cancer effects of CDDP. Conclusion These data suggested that the protective role of ALA in cisplatin-induced AKI is via protection of mitochondrial viability and prevents tubular apoptosis. Also there are no significant effects of ALA on anticancer efficiency of CDDP in rats. Thus, ALA has the potential to prevent CDDP nephrotoxicity without compromising its anticancer efficacy. PMID:24324635

  16. Effects of exogenous 5-aminolevulinic acid on photosynthesis, stomatal conductance, transpiration rate, and PIP gene expression of tomato seedlings subject to salinity stress.

    PubMed

    Zhao, Y Y; Yan, F; Hu, L P; Zhou, X T; Zou, Z R; Cui, L R

    2015-06-11

    The effects of exogenous 5-aminolevulinic acid (ALA) on photosynthesis, plant growth, and the expression of two aquaporin genes in tomato seedlings under control and salinity conditions were investigated. Exogenous ALA application significantly improved net photosynthetic rate (Pn), total chlorophyll content, and plant biomass accumulation of tomato seedlings under salinity stress. As revealed by real-time PCR analyses, after treatment with ALA alone, expression of both LePIP1 and LePIP2 in the two tomato cultivars was up-regulated at 2 h and subsequently decreased to normal levels. Under salinity stress, transcript levels of LePIP1 in both leaves and roots of salt-sensitive cultivars (cv. Zhongza No.9) increased significantly and were considerably higher than in cultivars exposed to ALA alone. In contrast, the expression levels of LePIP1 and LePIP2 in cvs. Jinpeng No.1 cultivars were slightly lower under salinity stress than under ALA treatment. In addition, transcript levels of both LePIP1 and LePIP2 in the roots of Jinpeng No. 1 cultivars were considerably lower than those in the roots of Zhongza No. 9 cultivars under salinity stress, regardless of ALA supplementation, implying that Jinpeng No. 1 cultivars had a better capacity to maintain membrane intrinsic protein stability. Further, ALA application distinctly counteracted the up- or down-regulation of LePIP1 and LePIP2 in both cultivars under salinity stress, in accordance with the improvements instomatal conductance, transpiration rate, and Pn of tomato leaves. The results presented here indicate that ALA controls aquaporin expression, thus, presumably ALA regulates water homeostasis and enhances salt tolerance of tomato seedlings.

  17. Novel theranostic nanoporphyrins for photodynamic diagnosis and trimodal therapy for bladder cancer.

    PubMed

    Lin, Tzu-Yin; Li, Yuanpei; Liu, Qiangqiang; Chen, Jui-Lin; Zhang, Hongyong; Lac, Diana; Zhang, Hua; Ferrara, Katherine W; Wachsmann-Hogiu, Sebastian; Li, Tianhong; Airhart, Susan; deVere White, Ralph; Lam, Kit S; Pan, Chong-Xian

    2016-10-01

    The overall prognosis of bladder cancer has not been improved over the last 30 years and therefore, there is a great medical need to develop novel diagnosis and therapy approaches for bladder cancer. We developed a multifunctional nanoporphyrin platform that was coated with a bladder cancer-specific ligand named PLZ4. PLZ4-nanoporphyrin (PNP) integrates photodynamic diagnosis, image-guided photodynamic therapy, photothermal therapy and targeted chemotherapy in a single procedure. PNPs are spherical, relatively small (around 23 nm), and have the ability to preferably emit fluorescence/heat/reactive oxygen species upon illumination with near infrared light. Doxorubicin (DOX) loaded PNPs possess slower drug release and dramatically longer systemic circulation time compared to free DOX. The fluorescence signal of PNPs efficiently and selectively increased in bladder cancer cells but not normal urothelial cells in vitro and in an orthotopic patient derived bladder cancer xenograft (PDX) models, indicating their great potential for photodynamic diagnosis. Photodynamic therapy with PNPs was significantly more potent than 5-aminolevulinic acid, and eliminated orthotopic PDX bladder cancers after intravesical treatment. Image-guided photodynamic and photothermal therapies synergized with targeted chemotherapy of DOX and significantly prolonged overall survival of mice carrying PDXs. In conclusion, this uniquely engineered targeting PNP selectively targeted tumor cells for photodynamic diagnosis, and served as effective triple-modality (photodynamic/photothermal/chemo) therapeutic agents against bladder cancers. This platform can be easily adapted to individualized medicine in a clinical setting and has tremendous potential to improve the management of bladder cancer in the clinic.

  18. Novel theranostic nanoporphyrins for photodynamic diagnosis and trimodal therapy for bladder cancer.

    PubMed

    Lin, Tzu-Yin; Li, Yuanpei; Liu, Qiangqiang; Chen, Jui-Lin; Zhang, Hongyong; Lac, Diana; Zhang, Hua; Ferrara, Katherine W; Wachsmann-Hogiu, Sebastian; Li, Tianhong; Airhart, Susan; deVere White, Ralph; Lam, Kit S; Pan, Chong-Xian

    2016-10-01

    The overall prognosis of bladder cancer has not been improved over the last 30 years and therefore, there is a great medical need to develop novel diagnosis and therapy approaches for bladder cancer. We developed a multifunctional nanoporphyrin platform that was coated with a bladder cancer-specific ligand named PLZ4. PLZ4-nanoporphyrin (PNP) integrates photodynamic diagnosis, image-guided photodynamic therapy, photothermal therapy and targeted chemotherapy in a single procedure. PNPs are spherical, relatively small (around 23 nm), and have the ability to preferably emit fluorescence/heat/reactive oxygen species upon illumination with near infrared light. Doxorubicin (DOX) loaded PNPs possess slower drug release and dramatically longer systemic circulation time compared to free DOX. The fluorescence signal of PNPs efficiently and selectively increased in bladder cancer cells but not normal urothelial cells in vitro and in an orthotopic patient derived bladder cancer xenograft (PDX) models, indicating their great potential for photodynamic diagnosis. Photodynamic therapy with PNPs was significantly more potent than 5-aminolevulinic acid, and eliminated orthotopic PDX bladder cancers after intravesical treatment. Image-guided photodynamic and photothermal therapies synergized with targeted chemotherapy of DOX and significantly prolonged overall survival of mice carrying PDXs. In conclusion, this uniquely engineered targeting PNP selectively targeted tumor cells for photodynamic diagnosis, and served as effective triple-modality (photodynamic/photothermal/chemo) therapeutic agents against bladder cancers. This platform can be easily adapted to individualized medicine in a clinical setting and has tremendous potential to improve the management of bladder cancer in the clinic. PMID:27479049

  19. Photodynamic Therapy

    NASA Astrophysics Data System (ADS)

    Kaščáková, Slávka; Giuliani, Alexandre; Jamme, Frédéric; Refregiers, Matthieu

    Treatments based on absorption of electromagnetic radiation may be categorized according to the photon wavelength range. On the one hand, radiotherapy is based on X-rays delivery to tissues and is widely spread and recognized for cancer treatment. On the other hand, photodynamic therapy (PDT) involves low energy radiation in the visible and near infrared range in combination with a drug referred to as the photosensitizer. A short overview of conventional radiotherapy and accelerator-based therapy is first presented. Then PDT is introduced and its mechanisms are reviewed along with the factors affecting its outcome. The domains of application of this therapy are presented through a discussion of the most used photosentizers. Finally we present new developments in the field that would permit the combination of potentialized radiotherapy and photodynamic therapy.

  20. ALA-Butyrate prodrugs for Photo-Dynamic Therapy

    NASA Astrophysics Data System (ADS)

    Berkovitch, G.; Nudelman, A.; Ehenberg, B.; Rephaeli, A.; Malik, Z.

    2010-05-01

    The use of 5-aminolevulinic acid (ALA) administration has led to many applications of photodynamic therapy (PDT) in cancer. However, the hydrophilic nature of ALA limits its ability to penetrate the cells and tissues, and therefore the need for ALA derivatives became an urgent research target. In this study we investigated the activity of novel multifunctional acyloxyalkyl ester prodrugs of ALA that upon metabolic hydrolysis release active components such as, formaldehyde, and the histone deacetylase inhibitory moiety, butyric acid. Evaluation of these prodrugs under photo-irradiation conditions showed that butyryloxyethyl 5-amino-4-oxopentanoate (ALA-BAC) generated the most efficient photodynamic destruction compared to ALA. ALA-BAC stimulated a rapid biosynthesis of protoporphyrin IX (PpIX) in human glioblastoma U-251 cells which resulted in generation of intracellular ROS, reduction of mitochondrial activity, leading to apoptotic and necrotic death of the cells. The apoptotic cell death induced by ALA / ALA-BAC followed by PDT equally activate intrinsic and extrinsic apoptotic signals and both pathways may occur simultaneously. The main advantage of ALA-BAC over ALA stems from its ability to induce photo-damage at a significantly lower dose than ALA.

  1. The application of 5-aminolevulinic acid in the treatment of precancerous lesions, skin cancer, and a new approach to the control of therapy

    NASA Astrophysics Data System (ADS)

    Kulas, Zbigniew; Bereś-Pawlik, Elżbieta; Bieniek, Andrzej; Matusiak, Łukasz

    2009-02-01

    The aim of our work was to determine a therapeutic effect of photodynamic therapy (PDT). Twenty five patients with the Bowen's disease, actinic keratosis and basal cell carcinoma (superficial, nodular) were examined. They were treated with photosensitizer - aminolevulinic acid (metabolized in protoporphyrin IX), and the new red light source built of high-power diodes. A new method, based on numerical analysis of fluorescence imaging of tissues, was proposed as a way for controlling therapy.

  2. Effect of cell cycle phase on the sensitivity of SAS cells to sonodynamic therapy using low-intensity ultrasound combined with 5-aminolevulinic acid in vitro.

    PubMed

    Li, Nan; Sun, Miao; Wang, Yao; Lv, Yanhong; Hu, Zheng; Cao, Wenwu; Zheng, Jinhua; Jiao, Xiaohui

    2015-08-01

    Sonodynamic therapy (SDT) with 5-aminolevulinic acid (5-ALA) can effectively inhibit various types of tumor in vitro and in vivo. However, the association between the efficacy of SDT and the phase of the cell cycle remains to be elucidated. 5-ALA may generate different quantities of sonosensitizer, protoporphyrin IX (PpIX), in different phases of the cell cycle, which may result in differences in sensitivity to 5-ALA-induced SDT. The present study aimed to investigate the effect of the cell cycle on the susceptibility of SAS cells to SDT following synchronization to different cell cycle phases. These results indicates that the rates of cell death and apoptosis of the SAS cells in the S and G2/M phases were significantly higher following SDT, compared with those in the G1-phase cells and unsynchronized cells, with a corresponding increase in PpIX in the S and G2/M cells. In addition, the expression of caspase-3 increased, while that of B-cell lymphoma (Bcl)-2 decreased markedly in theS and G2/M cells following SDT. Cyclin A was also expressed at higher levels in the S and G2/M cells, compared with the G1-phase cells. SDT also caused a significant upregulation of cyclin A in all phases of the cell cycle, however this was most marked in the S and G2/M cells. It was hypothesized that high expression levels of cyclin A in the S and G2/M cells may promote the induction of caspase-3 and reduce the induction of Bcl-2 by SDT and, therefore, enhance apoptosis. Taken together, these data demonstrated that cells in The S and G2/M phases generate more intracellular PpIX, have higher levels of cyclin A and are, therefore, more sensitive to SDT-induced cytotoxicity. These findings indicate the potential novel approach to preventing the onset of cancer by combining cell-cycle regulators with SDT. This sequential combination therapy may be a simple and cost-effective way of enhancing the effects of SDT in clinical settings.

  3. Quantitative fluorescence using 5-aminolevulinic acid–induced protoporphyrin IX biomarker as a surgical adjunct in low-grade glioma surgery

    PubMed Central

    Valdés, Pablo A.; Jacobs, Valerie; Harris, Brent T.; Wilson, Brian C.; Leblond, Frederic; Paulsen, Keith D.; Roberts, David W.

    2015-01-01

    OBJECT Previous studies in high-grade gliomas (HGGs) have indicated that protoporphyrin IX (PpIX) accumulates in higher concentrations in tumor tissue, and, when used to guide surgery, it has enabled improved resection leading to increased progression-free survival. Despite the benefits of complete resection and the advances in fluorescence-guided surgery, few studies have investigated the use of PpIX in low-grade gliomas (LGGs). Here, the authors describe their initial experience with 5-aminolevulinic acid (ALA)–induced PpIX fluorescence in a series of patients with LGG. METHODS Twelve patients with presumed LGGs underwent resection of their tumors after receiving 20 μg/kg of ALA approximately 3 hours prior to surgery under an institutional review board–approved protocol. Intraoperative assessments of the resulting PpIX emissions using both qualitative, visible fluorescence and quantitative measurements of PpIX concentration were obtained from tissue locations that were subsequently biopsied and evaluated histopathologically. Mixed models for random effects and receiver operating characteristic curve analysis for diagnostic performance were performed on the fluorescence data relative to the gold-standard histopathology. RESULTS Five of the 12 LGGs (1 ganglioglioma, 1 oligoastrocytoma, 1 pleomorphic xanthoastrocytoma, 1 oligodendroglioma, and 1 ependymoma) demonstrated at least 1 instance of visible fluorescence during surgery. Visible fluorescence evaluated on a specimen-by-specimen basis yielded a diagnostic accuracy of 38.0% (cutoff threshold: visible fluorescence score ≥ 1, area under the curve = 0.514). Quantitative fluorescence yielded a diagnostic accuracy of 67% (for a cutoff threshold of the concentration of PpIX [CPpIX] > 0.0056 μg/ml, area under the curve = 0.66). The authors found that 45% (9/20) of nonvisibly fluorescent tumor specimens, which would have otherwise gone undetected, accumulated diagnostically significant levels of CPpIX that were

  4. Photodynamic therapy of diseased bone

    NASA Astrophysics Data System (ADS)

    Bisland, Stuart K.; Yee, Albert; Siewerdsen, Jeffery; Wilson, Brian C.; Burch, Shane

    2005-08-01

    Objective: Photodynamic therapy (PDT) defines the oxygen-dependent reaction that occurs upon light-mediated activation of a photosensitizing compound, culminating in the generation of cytotoxic, reactive oxygen species, predominantly, singlet oxygen. We are investigating PDT treatment of diseased bone. Methods: Using a rat model of human breast cancer (MT-1)-derived bone metastasis we confirmed the efficacy of benzoporphyrin-derivative monoacid (BPD-MA)-PDT for treating metastatic lesions within vertebrae or long bones. Results: Light administration (150 J) 15 mins after BPDMA (2.5 mg/Kg, i.v.) into the lumbar (L3) vertebra of rats resulted in complete ablation of the tumour and surrounding bone marrow 48 hrs post-PDT without paralysis. Porcine vertebrae provided a model comparable to that of human for light propagation (at 150 J/cm) and PDT response (BPD-MA; 6 mg/m2, i.v.) in non-tumour vertebrae. Precise fibre placement was afforded by 3-D cone beam computed tomography. Average penetration depth of light was 0.16 +/- 0.04 cm, however, the necrotic/non-necrotic interface extended 0.6 cm out from the treatment fiber with an average incident fluence rate of 4.3 mW/cm2. Non-necrotic tissue damage was evident 2 cm out from the treatment fiber. Current studies involving BPD-MA-PDT treatment of primary osteosarcomas in the forelimbs of dogs are very promising. Magnetic resonance imaging 24 hr post treatment reveal well circumscribed margins of treatment that encompass the entire 3-4 cm lesion. Finally, we are also interested in using 5-aminolevulinic acid (ALA) mediated PDT to treat osteomyelitis. Response to therapy was monitored as changes in bioluminescence signal of staphylococcus aureus (SA)-derived biofilms grown onto 0.5 cm lengths of wire and subjected to ALA-PDT either in vitro or in vivo upon implant into the intramedullary space of rat tibia. Transcutaneous delivery of PDT (75 J/cm2) effectively eradicated SAbiofilms within bone. Conclusions: Results support

  5. Photodynamic therapy potentiates the paracrine endothelial stimulation by colorectal cancer

    NASA Astrophysics Data System (ADS)

    Lamberti, María Julia; Florencia Pansa, María; Emanuel Vera, Renzo; Belén Rumie Vittar, Natalia; Rivarola, Viviana Alicia

    2014-11-01

    Colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer death worldwide. Recurrence is a major problem and is often the ultimate cause of death. In this context, the tumor microenvironment influences tumor progression and is considered as a new essential feature that clearly impacts on treatment outcome, and must therefore be taken into consideration. Photodynamic therapy (PDT), oxygen, light and drug-dependent, is a novel treatment modality when CRC patients are inoperable. Tumor vasculature and parenchyma cells are both potential targets of PDT damage modulating tumor-stroma interactions. In biological activity assessment in photodynamic research, three-dimensional (3D) cultures are essential to integrate biomechanical, biochemical, and biophysical properties that better predict the outcome of oxygen- and drug-dependent medical therapies. Therefore, the objective of this study was to investigate the antitumor effect of methyl 5-aminolevulinic acid-PDT using a light emitting diode for the treatment of CRC cells in a scenario that mimics targeted tissue complexity, providing a potential bridge for the gap between 2D cultures and animal models. Since photodynamic intervention of the tumor microenvironment can effectively modulate the tumor-stroma interaction, it was proposed to characterize the endothelial response to CRC paracrine communication, if one of these two populations is photosensitized. In conclusion, we demonstrated that the dialogue between endothelial and tumor populations when subjected to lethal PDT conditions induces an increase in angiogenic phenotype, and we think that it should be carefully considered for the development of PDT therapeutic protocols.

  6. Update on photodynamic treatment for actinic keratosis.

    PubMed

    Wiegell, Stine Regin

    2015-01-01

    Photodynamic therapy (PDT) is an attractive treatment option for actinic keratoses (AKs), as large skin areas can be treated with high response rates and superior cosmetic outcome. The efficacy of 5-aminolevulinic acid (ALA)-PDT and methyl aminolevulinate (MAL)-PDT for AK has been proven in multiple studies, and this treatment is recommended in numerous consensus works and therapy guidelines. Moreover, a self-adhesive ALA patch has been approved for the PDT of AK. In a phase III study, ALA-patch-PDT was superior to cryotherapy and placebo in the treatment of mild to moderate AK on the face and scalp, and pre-treatment of the lesions and additional light occlusion was unnecessary when using the patch. ALA with a proprietary nanoemulsion is another newly marketed ALA gel that has been approved for the treatment of mild to moderate AK on the head. ALA was combined with a nanoemulsion to achieve increased chemical stability of the active ingredient and to enhance skin penetration. One study found that ALA was superior to MAL in the treatment of AK on the face or scalp. Daylight-PDT is a simpler and more tolerable treatment procedure for PDT, and three randomised studies have shown that daylight-PDT is an effective and pain-free treatment for AK; however, the procedure is limited by the need for a sufficient light dose and outdoor temperature. Ablative fractional laser resurfacing prior to MAL has been used to improve the PDT response of thick AK. However, more intense acute skin reactions and long-term adverse events in ablative fractional laser resurfacing-PDT compared with PDT-treated skin were found, which might limit the use of the intensified treatment.

  7. Photodynamic Therapy: One Step Ahead with Self-Assembled Nanoparticles

    PubMed Central

    Avci, Pinar; Erdem, S. Sibel; Hamblin, Michael R.

    2014-01-01

    Photodynamic therapy (PDT) is a promising treatment modality for cancer with possible advantages over current treatment alternatives. It involves combination of light and a photosensitizer (PS), which is activated by absorption of specific wavelength light and creates local tissue damage through generation of reactive oxygen species (ROS) that induce a cascade of cellular and molecular events. However, as of today, PDT is still in need of improvement and nanotechnology may play a role. PDT frequently employs PS with molecular structures that are highly hydrophobic, water insoluble and prone to aggregation. Aggregation of PS leads to reduced ROS generation and thus lowers the PDT activity. Some PS such as 5-aminolevulinic acid (ALA) cannot penetrate through the stratum corneum of the skin and systemic administration is not an option due to frequently encountered side effects. Therefore PS are often encapsulated or conjugated in/on nano-drug delivery vehicles to allow them to be better taken up by cells and to more selectively deliver them to tumors or other target tissues. Several nano-drug delivery vehicles including liposomes, fullerosomes and nanocells have been tested and reviewed. Here we cover non-liposomal self-assembled nanoparticles consisting of polymeric micelles including block co-polymers, polymeric micelles, dendrimers and porphysomes. PMID:25580097

  8. Photodynamic therapy improves the ultraviolet-irradiated hairless mice skin

    NASA Astrophysics Data System (ADS)

    Jorge, Ana Elisa S.; Hamblin, Michael R.; Parizotto, Nivaldo A.; Kurachi, Cristina; Bagnato, Vanderlei S.

    2014-03-01

    Chronic exposure to ultraviolet (UV) sunlight causes premature skin aging. In light of this fact, photodynamic therapy (PDT) is an emerging modality for treating cancer and other skin conditions, however its response on photoaged skin has not been fully illustrated by means of histopathology. For this reason, the aim of this study was analyze whether PDT can play a role on a mouse model of photoaging. Hence, SKH-1 hairless mice were randomly allocated in two groups, UV and UV/PDT. The mice were daily exposed to an UV light source (280-400 nm: peak at 350 nm) for 8 weeks followed by a single PDT session using 20% 5-aminolevulinic acid (ALA) topically. After the proper photosensitizer accumulation within the tissue, a non-coherent red (635 nm) light was performed and, after 14 days, skin samples were excised and processed for light microscopy, and their sections were stained with hematoxylin-eosin (HE) and Masson's Trichrome. As a result, we observed a substantial epidermal thickening and an improvement in dermal collagen density by deposition of new collagen fibers on UV/PDT group. These findings strongly indicate epidermal and dermal restoration, and consequently skin restoration. In conclusion, this study provides suitable evidences that PDT improves the UV-irradiated hairless mice skin, supporting this technique as an efficient treatment for photoaged skin.

  9. Usefulness of Photodynamic Therapy in the Management of Onychomycosis.

    PubMed

    Robres, P; Aspiroz, C; Rezusta, A; Gilaberte, Y

    2015-12-01

    Onychomycosis, or fungal infection of the nails, is one of the most prevalent fungal diseases in the general population. Treatment is of limited effectiveness, tedious, and must be administered for long periods. Furthermore, systemic antifungal agents are associated with adverse effects. Photodynamic therapy (PDT) may prove to be a viable alternative in the treatment of superficial skin infections, including onychomycosis. We review articles relating to the usefulness of PDT in onychomycosis in both in vitro and in vivo settings and discuss the potential and limitations of various photosensitizing agents. In vivo, methylene blue and 5-aminolevulinic acid have led to cure rates in 80% and 43% of cases, respectively, at 12 months. Finally, based on data in the literature and our own experience, we propose a protocol of 3 PDT sessions, separated by an interval of 1 or 2 weeks, using methyl aminolevulinate 16% as a photosensitizing agent and red light (λ=630 nm, 37 J.cm(-2)). Each session is preceded by the topical application of urea 40% over several days. Clinical trials are needed to optimize PDT protocols and to identify those patients who will benefit most from this treatment.

  10. Topical delivery of a preformed photosensitizer for photodynamic therapy of cutaneous lesions

    NASA Astrophysics Data System (ADS)

    Oleinick, Nancy L.; Kenney, Malcolm E.; Lam, Minh; McCormick, Thomas; Cooper, Kevin D.; Baron, Elma D.

    2012-02-01

    Photosensitizers for photodynamic therapy (PDT) are most commonly delivered to patients or experimental animals via intravenous injection. After initial distribution throughout the body, there can be some preferential accumulation within tumors or other abnormal tissue in comparison to the surrounding normal tissue. In contrast, the photosensitizer precursor, 5-aminolevulinic acid (ALA) or one of its esters, is routinely administered topically, and more specifically, to target skin lesions. Following metabolic conversion to protoporphyrin IX, the target area is photoilluminated, limiting peripheral damage and targeting the effective agent to the desired region. However, not all skin lesions are responsive to ALA-PDT. Topical administration of fully formed photosensitizers is less common but is receiving increased attention, and some notable advances with selected approved and experimental photosensitizers have been published. Our team has examined topical administration of the phthalocyanine photosensitizer Pc 4 to mammalian (human, mouse, pig) skin. Pc 4 in a desired formulation and concentration was applied to the skin surface at a rate of 5-10 μL/cm2 and kept under occlusion. After various times, skin biopsies were examined by confocal microscopy, and fluorescence within regions of interest was quantified. Early after application, images show the majority of the Pc 4 fluorescence within the stratum corneum and upper epidermis. As a function of time and concentration, penetration of Pc 4 across the stratum corneum and into the epidermis and dermis was observed. The data indicate that Pc 4 can be delivered to skin for photodynamic activation and treatment of skin pathologies.

  11. An irradiation system for photodynamic therapy with a fiber-optic sensor for measuring tissue oxygen

    NASA Astrophysics Data System (ADS)

    Quintanar, L.; Fabila, D.; Stolik, S.; de la Rosa, J. M.

    2013-11-01

    Photodynamic Therapy is a well known treatment based on the interaction of light of specific wavelength with a photosensitizing drug. In the presence of oxygen molecules, the illumination of the photosensitizer can activate the production of reactive oxygen species, which leads to the death of target cells within the treated tissue. In order to obtain the best therapy response, the tissue oxygen concentration should be measured to adjust the therapy parameters before and during the treatment. In this work, an irradiation system for 5-Aminolevulinic Acid Photodynamic Therapy is presented. It allows the application of visible light radiation of 630 nm using as a light source a high-brightness light emitting diode with an optical-power automatic control considering a light depth-distribution model. A module to measure the tissue oxygen saturation has been implemented into the system. It is based on two light emitting diodes of 660 nm and 940 nm as light sources, a photodiode as a detector and a new handheld fiber optic reflectance pulse oximetry sensor for estimating the blood oxygen saturation within the tissue. The pulse oximetry sensor was modeled through multilayered Monte Carlo simulations to study the behavior of the sensor with changes in skin thickness and melanin content.

  12. Quantitative approach to skin field cancerization using a nanoencapsulated photodynamic therapy agent: a pilot study

    PubMed Central

    Passos, Simone K; de Souza, Paulo EN; Soares, Priscila KP; Eid, Danglades RM; Primo, Fernando L; Tedesco, Antonio Cláudio; Lacava, Zulmira GM; Morais, Paulo C

    2013-01-01

    Background This paper introduces a new nanoformulation of 5-aminolevulinic acid (nano-ALA) as well as a novel quantitative approach towards evaluating field cancerization for actinic keratosis and/or skin photodamage. In this pilot study, we evaluated field cancerization using nano-ALA and methyl aminolevulinate (MAL), the latter being commercialized as Metvix®. Methods and results Photodynamic therapy was used for the treatment of patients with selected skin lesions, whereas the fluorescence of the corresponding photosensitizer was used to evaluate the time evolution of field cancerization in a quantitative way. Field cancerization was quantified using newly developed color image segmentation software. Using photodynamic therapy as the precancer skin treatment and the approach introduced herein for evaluation of fluorescent area, we found that the half-life of field cancerization reduction was 43.3 days and 34.3 days for nano-ALA and MAL, respectively. We also found that nano-ALA targeted about 45% more skin lesion areas than MAL. Further, we found the mean reduction in area of skin field cancerization was about 10% greater for nano-ALA than for MAL. Conclusion Although preliminary, our findings indicate that the efficacy of nano-ALA in treating skin field cancerization is higher than that of MAL. PMID:23450821

  13. Colloidal gold nanorings for improved photodynamic therapy through field-enhanced generation of reactive oxygen species

    NASA Astrophysics Data System (ADS)

    Hu, Yue; Yang, Yamin; Wang, Hongjun; Du, Henry

    2013-02-01

    Au nanostructures that exhibit strong localized surface plasmon resonance (SPR) have excellent potential for photo-medicine, among a host of other applications. Here, we report the synthesis and use of colloidal gold nanorings (GNRs) with potential for enhanced photodynamic therapy of cancer. The GNRs were fabricated via galvanic replacement reaction of sacrificial Co nanoparticles in gold salt solution with low molecular weight (Mw = 2,500) poly(vinylpyrrolidone) (PVP) as a stabilizing agent. The size and the opening of the GNRs were controlled by the size of the starting Co particles and the concentration of the gold salt. UV-Vis absorption measurements indicated the tunability of the SPR of the GNRs from 560 nm to 780 nm. MTT assay showed that GNRs were non-toxic and biocompatible when incubated with breast cancer cells as well as the healthy counterpart cells. GNRs conjugated with 5-aminolevulinic acid (5-ALA) photosensitizer precursor led to elevated formation of reactive oxygen species and improved efficacy of photodynamic therapy of breast cancer cells under light irradiation compared to 5-ALA alone. These results can be attributed to significantly enhance localized electromagnetic field of the GNRs.

  14. The Value of 5-Aminolevulinic Acid in Low-grade Gliomas and High-grade Gliomas Lacking Glioblastoma Imaging Features: An Analysis Based on Fluorescence, Magnetic Resonance Imaging, 18F-Fluoroethyl Tyrosine Positron Emission Tomography, and Tumor Molecular Factors

    PubMed Central

    Jaber, Mohammed; Wölfer, Johannes; Ewelt, Christian; Holling, Markus; Hasselblatt, Martin; Niederstadt, Thomas; Zoubi, Tarek; Weckesser, Matthias

    2015-01-01

    BACKGROUND: Approximately 20% of grade II and most grade III gliomas fluoresce after 5-aminolevulinic acid (5-ALA) application. Conversely, approximately 30% of nonenhancing gliomas are actually high grade. OBJECTIVE: The aim of this study was to identify preoperative factors (ie, age, enhancement, 18F-fluoroethyl tyrosine positron emission tomography [18F-FET PET] uptake ratios) for predicting fluorescence in gliomas without typical glioblastomas imaging features and to determine whether fluorescence will allow prediction of tumor grade or molecular characteristics. METHODS: Patients harboring gliomas without typical glioblastoma imaging features were given 5-ALA. Fluorescence was recorded intraoperatively, and biopsy specimens collected from fluorescing tissue. World Health Organization (WHO) grade, Ki-67/MIB-1 index, IDH1 (R132H) mutation status, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status, and 1p/19q co-deletion status were assessed. Predictive factors for fluorescence were derived from preoperative magnetic resonance imaging and 18F-FET PET. Classification and regression tree analysis and receiver-operating-characteristic curves were generated for defining predictors. RESULTS: Of 166 tumors, 82 were diagnosed as WHO grade II, 76 as grade III, and 8 as glioblastomas grade IV. Contrast enhancement, tumor volume, and 18F-FET PET uptake ratio >1.85 predicted fluorescence. Fluorescence correlated with WHO grade (P < .001) and Ki-67/MIB-1 index (P < .001), but not with MGMT promoter methylation status, IDH1 mutation status, or 1p19q co-deletion status. The Ki-67/MIB-1 index in fluorescing grade III gliomas was higher than in nonfluorescing tumors, whereas in fluorescing and nonfluorescing grade II tumors, no differences were noted. CONCLUSION: Age, tumor volume, and 18F-FET PET uptake are factors predicting 5-ALA-induced fluorescence in gliomas without typical glioblastoma imaging features. Fluorescence was associated with an increased

  15. Application of Titanium Dioxide (TiO2) Nanoparticles in Photodynamic Therapy (PDT) of an Experimental Tumor

    NASA Astrophysics Data System (ADS)

    Miyoshi, Norio; Kume, Kyo; Tsutumi, Kotaro; Fukunaga, Yukihiro; Ito, Shinnji; Imamura, Yoshiaki; Bibin, Andriana B.

    2011-12-01

    Nano-sized particles has been used for the photodynamic and sonodynamic treatments of pre-clinical cancer study in previous studies [1-7]. In this study, the 5-aminolevulinic acid (5-ALA) solution mixed with TiO2 nanoparticles was oral-administrated into the nude mouse transplanted under the skin with a human prostate cancer cell line. The experimental tumor model tissue (7×7×7 mm3) was measured of the size at different times after the photodynamic therapy (PDT) by laser to take a growth curve of the tumor. The treatment efficacy was jugged from the growth curves comparing different conditions. In the presence of the nanoparticle, the PDT treatment effect was enhanced those in the absence of the particles. Furthermore, the sonodynamic therapy (SDT) effect also enhanced with the nanoparticle to produce more OH radicals by ultrasound irradiation. These combination therapy of PDT and SDT with nanoparticles was very effectively resulted to be useful as a clinical use in future.

  16. In-vitro study on ALA-induced endogenous protoporphyrin IX as photosensitizer for photodynamic tumor diagnosis and therapy

    NASA Astrophysics Data System (ADS)

    Ueberriegler, K.; Fiedler, D.; Verwanger, Thomas; Schnitzhofer, Gerlinde; Banieghbal, E.; Krammer, Barbara E.

    1998-07-01

    Photodynamic tumor diagnosis and therapy is efficiently carried out by endogenous protoporphyrin IX as photosensitizer, induced by external addition of the precursor 5-aminolevulinic acid (ALA). In the present study, PpIX localization and photodynamically induced damage was investigated in normal and transformed human fibroblasts. PpIX formation reaches its maximum after incubation for at least 20 h with 700 (mu) g/m1 ALA, and increases with the pH- value. ALA has to be given 20-30 times more than external PpIX in order to produce the same cytotoxic damage. As detected by Low Light Imaging, PpIX is generated in the mitochondria, released to the cytoplasm and distributed to cytoplasma and nuclear membranes.The nucleus is not stained. Intracellular targets of PpIX damage after irradiation are mainly mitochondria, ER and nuclear membrane. The organelles show a decomposition pattern, which resembles apoptotic morphology and occurs faster in the co-cultivated transformed than in the normal cells. ALA-treated hepatocytes produce micronuclei and chromosomal aberrations, which indicates some mutagenic potential. Expression studies of the (proto)oncogenes c-myc and bcl-2 sublethally treated fibroblasts by quantitative RT-PCR show high deviations from the constitutive expression level, which are accompanied by cell cycle disturbances, indicating a possible precursor role to apoptosis introduction.

  17. Routine experimental system for defining conditions used in photodynamic therapy and fluorescence photodetection of (non-) neoplastic epithelia

    NASA Astrophysics Data System (ADS)

    Lange, Norbert; Vaucher, Laurent; Marti, Alexandre; Etter, Anne-Lise; Gerber, Patrick; van den Bergh, Hubert; Jichlinski, Patrice; Kucera, Pavel

    2001-04-01

    A common method to induce enhanced short-term endogenous porphyrin synthesis and accumulation in cell is the topical, systemic application of 5-aminolevulinic acid or one of its derivatives. This circumvents the intravenous administration of photosensitizers normally used for photodynamic therapy (PDT) of fluorescence photodetection. However, in the majority of potential medical indications, optimal conditions with respect to the porphyrin precursor or its pharmaceutical formulation have not yet been found. Due to ethical restrictions and animal right directives, the number of available test objects is limited. Hence, definition and use of nonanimal test methods are needed. Tissue and organ cultures are a promising approach in replacing cost intensive animal models in early stages of drug development. In this paper, we present a tissue culture, which can among others be used routinely to answer specific questions emerging in the field of photodynamic therapy and fluorescence photodetection. This technique uses mucosae excised from sheep paranasal sinuses or pig bladder, which is cultured under controlled conditions. It allows quasiquantative testing of different protoporphyrin IX precursors with respect to dose-response curves and pharmacokinetics, as well as the evaluation of different incubation conditions and/or different drug formulations. Furthermore, this approach, when combined with the use of electron microscopy and fluorescence-based methods, can be used to quantitatively determine the therapeutic outcome following protoporphyrin IX-mediated PDT.

  18. Designing photosensitizers for photodynamic therapy: strategies, challenges and promising developments.

    PubMed

    Garland, Martin J; Cassidy, Corona M; Woolfson, David; Donnelly, Ryan F

    2009-07-01

    Photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) are techniques that combine the effects of visible light irradiation with subsequent biochemical events that arise from the presence of a photosensitizing drug (possessing no dark toxicity) to cause destruction of selected cells. Despite its still widespread clinical use, Photofrin(®) has several drawbacks that limit its general clinical use. Consequently, there has been extensive research into the design of improved alternative photosensitizers aimed at overcoming these drawbacks. While there are many review articles on the subject of PDT and PACT, these have focused on the photosensitizers that have been used clinically, with little emphasis placed on how the chemical aspects of the molecule can affect their efficacy as PDT agents. Indeed, many of the PDT/PACT agents used clinically may not even be the most appropriate within a given class. As such, this review aims to provide a better understanding of the factors that have been investigated, while aiming at improving the efficacy of a molecule intended to be used as a photosensitizer. Recent publications, spanning the last 5 years, concerning the design, synthesis and clinical usage of photosensitizers for application in PDT and PACT are reviewed, including 5-aminolevulinic acid, porphyrins, chlorins, bacteriochlorins, texaphyrins, phthalocyanines and porphycenes. It has been shown that there are many important considerations when designing a potential PDT/PACT agent, including the influence of added groups on the lipophilicity of the molecule, the positioning and nature of these added groups within the molecule, the presence of a central metal ion and the number of charges that the molecule possesses. The extensive ongoing research within the field has led to the identification of a number of potential lead molecules for application in PDT/PACT. The development of the second-generation photosensitizers, possessing shorter periods of

  19. Mechanistic studies of malonic acid-mediated in situ acylation.

    PubMed

    Chandra, Koushik; Naoum, Johnny N; Roy, Tapta Kanchan; Gilon, Chaim; Gerber, R Benny; Friedler, Assaf

    2015-09-01

    We have previously introduced an easy to perform, cost-effective and highly efficient acetylation technique for solid phase synthesis (SPPS). Malonic acid is used as a precursor and the reaction proceeds via a reactive ketene that acetylates the target amine. Here we present a detailed mechanistic study of the malonic acid-mediated acylation. The influence of reaction conditions, peptide sequence and reagents was systematically studied. Our results show that the methodology can be successfully applied to different types of peptides and nonpeptidic molecules irrespective of their structure, sequence, or conformation. Using alkyl, phenyl, and benzyl malonic acid, we synthesized various acyl peptides with almost quantitative yields. The ketenes obtained from the different malonic acid derived precursors were characterized by in situ (1) H-NMR. The reaction proceeded in short reaction times and resulted in excellent yields when using uronium-based coupling agents, DIPEA as a base, DMF/DMSO/NMP as solvents, Rink amide/Wang/Merrifield resins, temperature of 20°C, pH 8-12 and 5 min preactivation at inert atmosphere. The reaction was unaffected by Lewis acids, transition metal ions, surfactants, or salt. DFT studies support the kinetically favorable concerted mechanism for CO2 and ketene formation that leads to the thermodynamically stable acylated products. We conclude that the malonic acid-mediated acylation is a general method applicable to various target molecules. PMID:25846609

  20. Whole bladder wall photodynamic therapy using 5-ALA: an experimental study in pigs

    NASA Astrophysics Data System (ADS)

    van Staveren, Hugo J.; Beek, Johan F.; Verlaan, Cess W.; Edixhoven, Annie; Saarnak, Anne E.; Sterenborg, Dick; de Reijke, Theo M.; de la Riviere, Guy B.; Thomsen, Sharon L.; van Gemert, Martin J. C.; Star, Willem M.

    1996-01-01

    The agent 5-aminolevulinic acid (5-ALA) can be an alternative drug in whole bladder wall (WBW) photodynamic therapy (PDT), as its good tumor selectivity and the short time skin photosensitivity after systemic administration are advantageous for clinical use. To determine the maximum drug and light doses for reversible normal tissue damage, a pre-clinical study was performed using an in vivo normal piglet bladder model. First, the kinetics of PpIX production in 2 pigs was determined in vitro after oral administration of 75 and 150 mg/kg ALA respectively. The concentration of PpIX in plasma, and erythrocytes was determined by reversed phase high-performance liquid chromatography (HPLC) and the maximum was reached at approximately equals 5 hours after the administration of ALA. This provided a guideline for the optimum interval between ALA administration and light application. Next, various ALA doses were either administered orally or instilled in the bladder and different light doses were applied. Bladder biopsies were taken at regular intervals and normal tissue damage was investigated histologically. Reversible tissue damage was obtained using 60 mg/kg of 5-ALA in combination with a light dose of 100 J cm-2 (non-scattered plus scattered 630 nm wavelength light) in the case of oral administration. In the case of intravesical instillation, a drug dose of 2.5 gram and a light dose of 100 J cm-2 are still too high to obtain reversible tissue damage.

  1. Surgery combined with topical photodynamic therapy for the treatment of squamous cell carcinoma of the lip.

    PubMed

    Wang, Yuanyuan; Yang, Yadong; Yang, Yunchuan; Lu, Yuangang

    2016-06-01

    Due to the unique location of the squamous cell carcinoma (SCC) of the lip, using a single method such as extended resection or radiotherapy probably causes morphological and functional defects. So we used surgery combined with topical photodynamic therapy (PDT) to treat SCC of the lip. Under local anesthesia with 5% lidocaine, the hyperplastic and ulcerative SCC of the lip were curetted and assisted by topical PDTs after surgery. The 20% 5-aminolevulinic acid cream was used as a photosensitizer and applied evenly to the surface of the tumor lesion for 4h. Then the lesion site was irradiated with a 635-nm laser at 120J/cm(2). A total of five PDTs were performed postoperatively at an interval of 2 weeks. Photos were taken before and after every PDT to compare the skin lesions, treatment effects, and side effects. A long-term follow-up was undertaken to observe tumor recurrence. After surgery combined with five topical PDTs, the SCC of the lip disappeared without the compromised morphology of the lip, significant side effects, or tumor recurrence in one-year follow-up. Surgery combined with topical PDT can reduce the excision size of tumors and play a positive role in the treatment of tumors of special locations. PMID:27102062

  2. Photodynamic Therapy with Ablative Carbon Dioxide Fractional Laser in Treatment of Actinic Keratosis

    PubMed Central

    Jang, Yong Hyun; Lee, Dong Jun; Shin, Jaeyoung; Kang, Hee Young; Lee, Eun-So

    2013-01-01

    Background Recently, photodynamic therapy (PDT) has been shown to be an effective first-line treatment for actinic keratosis (AK). However, a major limitation of PDT is the long incubation time required to allow penetration of the photosensitizer. Objective The aim of this study was to assess if pretreatment with an ablative carbon dioxide (CO2) fractional laser can reduce the incubation time of the photosensitizer. Methods Initially, 29 patients with a total of 34 AK lesions were treated with an ablative CO2 fractional laser at Ajou University Hospital between January and December 2010. Immediately after the laser treatment, topical 20% 5-aminolevulinic acid or methyl-aminolevulinate was applied to the AK lesions and incubated for 70 to 90 minutes. Then, the treated areas were illuminated with a red light source. Improvement was clinically or histologically assessed eight weeks after the treatment. Results In spite of the short incubation time, 24 lesions (70.6%) showed a complete response (CR) within three sessions of PDT (10 lesions a clinical CR and 14 lesions a clinical/histological CR). There were no significant side effects associated with the combination of ablative CO2 fractional laser and PDT. Conclusion Ablative CO2 fractional laser may be considered an additional treatment option for reducing the incubation time of the photosensitizer in PDT. PMID:24371387

  3. Photodynamic and Antibiotic Therapy in Combination to Fight Biofilms and Resistant Surface Bacterial Infections

    PubMed Central

    Barra, Federica; Roscetto, Emanuela; Soriano, Amata A.; Vollaro, Adriana; Postiglione, Ilaria; Pierantoni, Giovanna Maria; Palumbo, Giuseppe; Catania, Maria Rosaria

    2015-01-01

    Although photodynamic therapy (PDT), a therapeutic approach that involves a photosensitizer, light and O2, has been principally considered for the treatment of specific types of cancers, other applications exist, including the treatment of infections. Unfortunately, PDT does not always guarantee full success since it exerts lethal effects only in cells that have taken up a sufficient amount of photosensitizer and have been exposed to adequate light doses, conditions that are not always achieved. Based on our previous experience on the combination PDT/chemotherapy, we have explored the possibility of fighting bacteria that commonly crowd infected surfaces by combining PDT with an antibiotic, which normally does not harm the strain at low concentrations. To this purpose, we employed 5-aminolevulinic acid (5-ALA), a pro-drug that, once absorbed by proliferating bacteria, is converted into the natural photosensitizer Protoporphyrin IX (PpIX), followed by Gentamicin. Photoactivation generates reactive oxygen species (ROS) which damage or kill the cell, while Gentamicin, even at low doses, ends the work. Our experiments, in combination, have been highly successful against biofilms produced by several Gram positive bacteria (i.e., Staphylococcus aureus, Staphylococcus epidermidis, etc.). This original approach points to potentially new and wide applications in the therapy of infections of superficial wounds and sores. PMID:26343645

  4. Comparison of three light doses in the photodynamic treatment of actinic keratosis using mathematical modeling

    NASA Astrophysics Data System (ADS)

    Vignion-Dewalle, Anne-Sophie; Betrouni, Nacim; Tylcz, Jean-Baptiste; Vermandel, Maximilien; Mortier, Laurent; Mordon, Serge

    2015-05-01

    Photodynamic therapy (PDT) is an emerging treatment modality for various diseases, especially for cancer therapy. Although high efficacy is demonstrated for PDT using standardized protocols in nonhyperkeratotic actinic keratoses, alternative light doses expected to increase efficiency, to reduce adverse effects or to expand the use of PDT, are still being evaluated and refined. We propose a comparison of the three most common light doses in the treatment of actinic keratosis with 5-aminolevulinic acid PDT through mathematical modeling. The proposed model is based on an iterative procedure that involves determination of the local fluence rate, updating of the local optical properties, and estimation of the local damage induced by the therapy. This model was applied on a simplified skin sample model including an actinic keratosis lesion, with three different light doses (red light dose, 37 J/cm2, 75 mW/cm2, 500 s blue light dose, 10 J/cm2, 10 mW/cm2, 1000 s and daylight dose, 9000 s). Results analysis shows that the three studied light doses, although all efficient, lead to variable local damage. Defining reference damage enables the nonoptimal parameters for the current light doses to be refined and the treatment to be more suitable.

  5. Photodynamic therapy induces epidermal thickening in hairless mice skin: an optical coherence tomography assessment

    NASA Astrophysics Data System (ADS)

    Jorge, Ana Elisa S.; Campos, Carolina P.; Freitas, Anderson Z.; Bagnato, Vanderlei S.

    2014-03-01

    Photodynamic therapy (PDT) promotes skin improvement according to many practitioners, however the immediately in vivo assessment of its response remains clinically inaccessible. As a non-invasive modality, optical coherence tomography (OCT) has been shown a feasible optical diagnostic technique that provides images in real time, avoiding tissue biopsies. For this reason, our investigation focused on evaluates the PDT effect on a rodent model by means of OCT. Therefore, a normal hairless mouse skin has undergone a single-session PDT, which was performed with topical 5- aminolevulinic acid (ALA) cream using a red (630 nm) light emitting diode (LED) which reached the light dose of 75 J/cm2. As the optical imaging tool, an OCT (930 nm) with axial resolution of 6.0 microns in air was used, generating images with contact to the mouse skin before, immediately after, 24 hours, and 2 weeks after the correspondent procedure. Our result demonstrates that, within 24 hours after ALA-PDT, the mouse skin from the PDT group has shown epidermal thickness (ET), which has substantially increased after 2 weeks from the treatment day. Moreover, the skin surface has become evener after ALA-PDT. Concluding, this investigation demonstrates that the OCT is a feasible and reliable technique that allows real-time cross-sectional imaging of skin, which can quantify an outcome and predict whether the PDT reaches its goal.

  6. Surgery combined with topical photodynamic therapy for the treatment of squamous cell carcinoma of the lip.

    PubMed

    Wang, Yuanyuan; Yang, Yadong; Yang, Yunchuan; Lu, Yuangang

    2016-06-01

    Due to the unique location of the squamous cell carcinoma (SCC) of the lip, using a single method such as extended resection or radiotherapy probably causes morphological and functional defects. So we used surgery combined with topical photodynamic therapy (PDT) to treat SCC of the lip. Under local anesthesia with 5% lidocaine, the hyperplastic and ulcerative SCC of the lip were curetted and assisted by topical PDTs after surgery. The 20% 5-aminolevulinic acid cream was used as a photosensitizer and applied evenly to the surface of the tumor lesion for 4h. Then the lesion site was irradiated with a 635-nm laser at 120J/cm(2). A total of five PDTs were performed postoperatively at an interval of 2 weeks. Photos were taken before and after every PDT to compare the skin lesions, treatment effects, and side effects. A long-term follow-up was undertaken to observe tumor recurrence. After surgery combined with five topical PDTs, the SCC of the lip disappeared without the compromised morphology of the lip, significant side effects, or tumor recurrence in one-year follow-up. Surgery combined with topical PDT can reduce the excision size of tumors and play a positive role in the treatment of tumors of special locations.

  7. Comparison of three light doses in the photodynamic treatment of actinic keratosis using mathematical modeling.

    PubMed

    Vignion-Dewalle, Anne-Sophie; Betrouni, Nacim; Tylcz, Jean-Baptiste; Vermandel, Maximilien; Mortier, Laurent; Mordon, Serge

    2015-05-01

    Photodynamic therapy (PDT) is an emerging treatment modality for various diseases, especially for cancer therapy. Although high efficacy is demonstrated for PDT using standardized protocols in nonhyperkeratotic actinic keratoses, alternative light doses expected to increase efficiency, to reduce adverse effects or to expand the use of PDT, are still being evaluated and refined. We propose a comparison of the three most common light doses in the treatment of actinic keratosis with 5-aminolevulinic acid PDT through mathematical modeling. The proposed model is based on an iterative procedure that involves determination of the local fluence rate, updating of the local optical properties, and estimation of the local damage induced by the therapy. This model was applied on a simplified skin sample model including an actinic keratosis lesion, with three different light doses (red light dose, 37 J∕cm2, 75 mW∕cm2, 500 s; blue light dose, 10 J∕cm2, 10 mW∕cm2, 1000 s; and daylight dose, 9000 s). Results analysis shows that the three studied light doses, although all efficient, lead to variable local damage. Defining reference damage enables the nonoptimal parameters for the current light doses to be refined and the treatment to be more suitable.

  8. Photodynamic therapy: Theoretical and experimental approaches to dosimetry

    NASA Astrophysics Data System (ADS)

    Wang, Ken Kang-Hsin

    Singlet oxygen (1O2) is the major cytotoxic species generated during photodynamic therapy (PDT), and 1O 2 reactions with biological targets define the photodynamic dose at the most fundamental level. We have developed a theoretical model for rigorously describing the spatial and temporal dynamics of oxygen (3O 2) consumption and transport and microscopic 1O 2 dose deposition during PDT in vivo. Using experimentally established physiological and photophysical parameters, the mathematical model allows computation of the dynamic variation of hemoglobin-3O 2 saturation within vessels, irreversible photosensitizer degradation due to photobleaching, therapy-induced blood flow decrease and the microscopic distributions of 3O2 and 1O 2 dose deposition under various irradiation conditions. mTHPC, a promising photosensitizer for PDT, is approved in Europe for the palliative treatment of head and neck cancer. Using the theoretical model and informed by intratumor sensitizer concentrations and distributions, we calculated photodynamic dose depositions for mTHPC-PDT. Our results demonstrate that the 1O 2 dose to the tumor volume does not track even qualitatively with long-term tumor responses. Thus, in this evaluation of mTHPC-PDT, any PDT dose metric that is proportional to singlet oxygen creation and/or deposition would fail to predict the tumor response. In situations like this one, other reporters of biological response to therapy would be necessary. In addition to the case study of mTHPC-PDT, we also use the mathematical model to simulate clinical photobleaching data, informed by a possible blood flow reduction during treatment. In a recently completed clinical trial at Roswell Park Cancer Institute, patients with superficial basal cell carcinoma received topical application of 5-aminolevulinic acid (ALA) and were irradiated with 633 nm light at 10-150 mW cm-2 . Protoporphyrin IX (PpIX) photobleaching in the lesion and the adjacent perilesion normal margin was monitored by

  9. Single LED-based device to perform widefield fluorescence imaging and photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Grecco, Clovis; Buzzá, Hilde H.; Stringasci, Mirian D.; Andrade, Cintia T.; Vollet-Filho, Jose D.; Pratavieira, Sebastião.; Zanchin, Anderson L.; Tuboy, Aparecida M.; Bagnato, Vanderlei S.

    2015-06-01

    Photodynamic therapy (PDT) is a treatment modality that can be indicated for several cancer types and pre-cancer lesions. One of the main applications of PDT is the treatment of superficial skin lesions such as basal cell carcinoma, Bowen's disease and actinic keratosis. Three elements are necessary in PDT, a photosensitizer (PS); light at specific wavelength to be absorbed by the PS, and molecular oxygen. A typical PS used for skin lesion is protoporphyrin IX (PpIX), which is an intrinsic PS; its production is stimulated by a pro-drug, such as 5-aminolevulinic acid (ALA). Before starting a treatment, it is very important to follow up the PpIX production (to ensure that enough PS was produced prior to a PDT application) and, during a PDT session, to monitor its photodegradation (as it is evidence of the photodynamic effect taking place). The aim of this paper is to present a unique device, LINCE (MMOptics - São Carlos, Brazil), that brings together two probes that can, respectively, allow for fluorescence imaging and work as a light source for PDT treatment. The fluorescence probe of the system is optically based on 400 nm LED (light emitting diodes) arrays that allow observing the fluorescence emission over 450 nm. The PDT illumination probe options are constituted of 630 nm LED arrays for small areas and, for large areas, of both 630 nm and 450 nm LED arrays. Joining both functions at the same device makes PDT treatment simpler, properly monitorable and, hence, more clinically feasible. LINCE has been used in almost 1000 PDT treatments of superficial skin lesions in Brazil, with 88.4% of clearance of superficial BCC.

  10. Critical role of ABCG2 in ALA-photodynamic diagnosis and therapy of human brain tumor.

    PubMed

    Ishikawa, Toshihisa; Kajimoto, Yoshinaga; Inoue, Yutaka; Ikegami, Yoji; Kuroiwa, Toshihiko

    2015-01-01

    Primary brain tumors occur in around 250,000 people per year globally. Survival rates in primary brain tumors depend on the type of tumor, patient's age, the extent of surgical tumor removal, and other factors. Photodynamic diagnosis (PDD) is a practical tool currently used in surgical operation of aggressive brain tumors, such as glioblastoma and meningiomas, whereas clinical application of photodynamic therapy (PDT) to brain tumor therapy has just recently started. Both PDD and PDT are achieved by a photon-induced physicochemical reaction, which is induced by the excitation of porphyrins exposed to light. In fluorescence-guided gross-total resection, PDD can be achieved by the administration of 5-aminolevulinic acid (5-ALA) as the precursor of protoporphyrin IX (PpIX). Exogenously administered ALA induces biosynthesis and accumulation of PpIX, a natural photosensitizer, in cancer cells. However, ATP-binding cassette transporter ABCG2 plays a critical role in regulating the cellular accumulation of porphyrins in cancer cells and thereby its expression and function can affect the efficacy of PDD and PDT. In response to the photoreaction of porphyrins leading to oxidative stress, the nuclear factor erythroid-derived 2-related transcription factor can transcriptionally upregulate ABCG2, which may reduce the efficacy of PDD and PDT. On the other hand, certain protein kinase inhibitors potentially enhance the efficacy of PDD and PDT by blocking ABCG2-mediated porphyrin efflux from cancer cells. In this context, it is of great interest to develop ABCG2 inhibitors that can be applied to PDD or PDT for the therapy of brain tumor and other tumors.

  11. Co-expression of autophagic markers following photodynamic therapy in SW620 human colon adenocarcinoma cells

    PubMed Central

    Ziółkowska, Barbara; Woźniak, Marta; Ziółkowski, Piotr

    2016-01-01

    Photodynamic therapy (PDT) is a minimally invasive cancer treatment. It involves the combination of a photosensitizer and light of a specific wavelength to generate singlet oxygen and other reactive oxygen species that lead to tumor cell death. Autophagy is one of the pathways that tumor cells undergo during photodamage and it is common in photodynamic therapy. The aim of this study was to examine the effect of in vitro PDT on the expression of autophagy-related proteins, autophagy related 7 (Atg7), light chain 3 (LC3) and Beclin-1. Human SW620 colon carcinoma cells were treated with 5-aminolevulinic acid (ALA)-based PDT at a dose of 3 mM. The irradiation was performed using 4.5 J/cm2 total light and a fluence rate of 60 mW/cm2. Autophagy was evaluated by immunocytochemistry using specific antibodies to Atg7, Beclin-1 and LC3. The evaluation was repeated at several time points (0, 4, 8 and 24 h) following irradiation. The induction of autophagy was observed directly following the 5-ALA-mediated PDT procedure with the strongest expression of autophagy-related proteins at 4 and 8 h after irradiation as demonstrated using immunocytochemistry. It was characterized by significantly increased expression of Beclin-1, Atg7 and LC3. To the best of our knowledge this is the first study to analyze Beclin-1, Atg7 and LC3 expression in a PDT-related experiment. This study enhances the understanding of the role of autophagy in PDT, which may contribute to better and more effective tumor responses to this therapy. PMID:27485939

  12. Study of the efficacy of 5 ALA-mediated photodynamic therapy on human larynx squamous cell carcinoma (Hep2c) cell line

    NASA Astrophysics Data System (ADS)

    Khursid, A.; Atif, M.; Firdous, S.; Zaidi, S. S. Z.; Salman, R.; Ikram, M.

    2010-07-01

    5-aminolevulanic acid (ALA), a precursor of Protoporphyrin IX, was evaluated as an inducer of photodamage on Hep2c, human larynx squamous cell carcinoma, cell line. Porphyrins are used as active cytotoxic antitumor agents in photodynamic therapy (PDT). The present study evaluates the effects of photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) using human larynx cells as experimental model. Hep2c cell line was irradiated with red light (a diode laser, λ = 635 nm). The influence of different incubation times and concentrations of 5-ALA, different irradiation doses and various combinations of photosensitizer and light doses on the cellular viability of Hep2c cells were studied. The optimal uptake of photosensitizer ALA in Hep-2c cells was investigated by means of spectrometric measurement. Cells viability was determined by means of neutral red assay (NR). It was observed that sensitizer or light doses have no significant effect on cells viability when studied independently. The spectrometric measurements showed that the maximal cellular uptake of 5-ALA occurred after 7 h in vitro incubation. The photocytotoxic assay showed that light dose of 85 J/cm2 gives effective PDT outcome for Hep2c cell line incubated with 55 μg/ml of 5-ALA with a conclusion that Hep2c cell line is sensitive to ALA-mediated PDT.

  13. Photodynamic therapy in dentistry.

    PubMed

    Konopka, K; Goslinski, T

    2007-08-01

    Photodynamic therapy (PDT), also known as photoradiation therapy, phototherapy, or photochemotherapy, involves the use of a photoactive dye (photosensitizer) that is activated by exposure to light of a specific wavelength in the presence of oxygen. The transfer of energy from the activated photosensitizer to available oxygen results in the formation of toxic oxygen species, such as singlet oxygen and free radicals. These very reactive chemical species can damage proteins, lipids, nucleic acids, and other cellular components. Applications of PDT in dentistry are growing rapidly: the treatment of oral cancer, bacterial and fungal infection therapies, and the photodynamic diagnosis (PDD) of the malignant transformation of oral lesions. PDT has shown potential in the treatment of oral leukoplakia, oral lichen planus, and head and neck cancer. Photodynamic antimicrobial chemotherapy (PACT) has been efficacious in the treatment of bacterial, fungal, parasitic, and viral infections. The absence of genotoxic and mutagenic effects of PDT is an important factor for long-term safety during treatment. PDT also represents a novel therapeutic approach in the management of oral biofilms. Disruption of plaque structure has important consequences for homeostasis within the biofilm. Studies are now leading toward selective photosensitizers, since killing the entire flora leaves patients open to opportunistic infections. Dentists deal with oral infections on a regular basis. The oral cavity is especially suitable for PACT, because it is relatively accessible to illumination. PMID:17652195

  14. Photodynamic immune modulation (PIM)

    NASA Astrophysics Data System (ADS)

    North, John R.; Hunt, David W. C.; Simkin, Guillermo O.; Ratkay, Leslie G.; Chan, Agnes H.; Lui, Harvey; Levy, Julia G.

    1999-09-01

    Photodynamic Therapy (PDT) is accepted for treatment of superficial and lumen-occluding tumors in regions accessible to activating light and is now known to be effective in closure of choroidal neovasculature in Age Related Macular Degeneration. PDT utilizes light absorbing drugs (photosensitizers) that generate the localized formation of reactive oxygen species after light exposure. In a number of systems, PDT has immunomodulatory effects; Photodynamic Immune Modulation (PIM). Using low- intensity photodynamic regimens applied over a large body surface area, progression of mouse autoimmune disease could be inhibited. Further, this treatment strongly inhibited the immunologically- medicated contact hypersensitivity response to topically applied chemical haptens. Immune modulation appears to result from selective targeting of activated T lymphocytes and reduction in immunostimulation by antigen presenting cells. Psoriasis, an immune-mediated skin condition, exhibits heightened epidermal cell proliferation, epidermal layer thickening and plaque formation at different body sites. In a recent clinical trial, approximately one-third of patients with psoriasis and arthritis symptoms (psoriatic arthritis) displayed a significant clinical improvement in several psoriasis-related parameters after four weekly whole-body PIM treatments with verteporfin. The safety profile was favorable. The capacity of PIM to influence other human immune disorders including rheumatoid arthritis is under extensive evaluation.

  15. Cetalox and analogues: synthesis via acid-mediated polyene cyclizations.

    PubMed

    Snowden, Roger L

    2008-06-01

    Using a novel, acid-mediated cyclization methodology, a direct access to Cetalox ((+/-)-1; a commercially important ambergris-type odorant) and various structurally related didehydro (i.e., 19, 26, and 30) and tetradehydro (i.e., 28 and 37/38) analogues is described. Treatment of either (E,E)-14 or (E)-15 with an excess of FSO(3)H in 2-nitropropane at -90 degrees stereospecifically afforded (+/-)-1 in 40 and 42% yield, respectively. Under similar conditions, cyclization of (E)-18 or 20 furnished 19 in 60 and 64% yield, respectively. Analogously, using an excess of ClSO(3)H in CH(2)Cl(2) at -80 degrees, 26 is formed with high stereoselectivity by cyclization of either (E)-24 or (Z)-25 (52 and 31% yield, resp.); in the same manner, 28 was prepared from 27 (22% yield). The same principle was applied to the synthesis of racemic Superambrox (30), via cyclization of 35, but only with poor selectivity (22%) and low yield (7%). Another approach via cyclization of (E)-40 under solvolysis conditions (excess TFA in CH(2)Cl(2) at -10 degrees) gave a higher yield (15%) with improved selectivity (43%). Finally, cyclization of 34 (1:1 diastereoisomer mixture) afforded 37/38 (10:1) in 27% yield. The qualitative organoleptic properties of 19, 26, 28, 30, and 37/38 (10:1) are briefly discussed.

  16. Ca(2+)/calmodulin regulates salicylic-acid-mediated plant immunity.

    PubMed

    Du, Liqun; Ali, Gul S; Simons, Kayla A; Hou, Jingguo; Yang, Tianbao; Reddy, A S N; Poovaiah, B W

    2009-02-26

    Intracellular calcium transients during plant-pathogen interactions are necessary early events leading to local and systemic acquired resistance. Salicylic acid, a critical messenger, is also required for both of these responses, but whether and how salicylic acid level is regulated by Ca(2+) signalling during plant-pathogen interaction is unclear. Here we report a mechanism connecting Ca(2+) signal to salicylic-acid-mediated immune response through calmodulin, AtSR1 (also known as CAMTA3), a Ca(2+)/calmodulin-binding transcription factor, and EDS1, an established regulator of salicylic acid level. Constitutive disease resistance and elevated levels of salicylic acid in loss-of-function alleles of Arabidopsis AtSR1 suggest that AtSR1 is a negative regulator of plant immunity. This was confirmed by epistasis analysis with mutants of compromised salicylic acid accumulation and disease resistance. We show that AtSR1 interacts with the promoter of EDS1 and represses its expression. Furthermore, Ca(2+)/calmodulin-binding to AtSR1 is required for suppression of plant defence, indicating a direct role for Ca(2+)/calmodulin in regulating the function of AtSR1. These results reveal a previously unknown regulatory mechanism linking Ca(2+) signalling to salicylic acid level.

  17. Oxalic acid-mediated stress responses in Brassica napus L.

    PubMed

    Liang, Yue; Strelkov, Stephen E; Kav, Nat N V

    2009-06-01

    Oxalic acid (OA) occurs extensively in nature and plays diverse roles, especially in pathogenic processes involving various plant pathogens. However, proteome changes and modifications of signaling and oxidative network of plants in response to OA are not well understood. In order to investigate the responses of Brassica napus toward OA, a proteome analysis was conducted employing 2-DE with MS/MS. A total of 37 proteins were identified as responding to OA stress, of which 13 were up-regulated and 24 were down-regulated. These proteins were categorized into several functional groups including protein processing, RNA processing, photosynthesis, signal transduction, stress response, and redox homeostasis. Investigation of the effect of OA on phytohormone signaling and oxidative responses revealed that jasmonic acid-, ethylene-, and abscisic acid-mediated signaling pathways appear to increase at later time points, whereas those pathways mediated by salicylic acid appear to be suppressed. Moreover, the activities of the antioxidant enzymes catalase, peroxidase, superoxide dismutase and oxalic acid oxidase, but not NADPH oxidase, were suppressed by OA stress. Our findings are discussed within the context of the proposed role(s) of OA during infection by Sclerotinia sclerotiorum and subsequent disease progression. PMID:19526549

  18. Retinoic acid-mediated gene expression in transgenic reporter zebrafish.

    PubMed

    Perz-Edwards, A; Hardison, N L; Linney, E

    2001-01-01

    Retinoic acid-mediated gene activation is important for normal vertebrate development. The size and nature of retinoic acid make it difficult to identify the precise cellular location of this signaling molecule throughout an embryo. Additionally, retinoic acid (RA) signaling is regulated by a complex combination of receptors, coactivators, and antagonizing proteins. Thus, in order to integrate these signals and identify regions within a whole developing embryo where cells can respond transcriptionally to retinoic acid, we have used a reporter transgenic approach. We have generated several stable lines of transgenic zebrafish which use retinoic acid response elements to drive fluorescent protein expression. In these zebrafish lines, transgene expression is localized to regions of the neural tube, retina, notochord, somites, heart, pronephric ducts, branchial arches, and jaw muscles in embryos and larvae. Transgene expression can be induced in additional regions of the neural tube and retina as well as the immature notochord, hatching gland, enveloping cell layer, and fin by exposing embryos to retinoic acid. Treatment with retinoic acid synthase inhibitors, citral and diethylaminobenzaldehyde (DEAB), during neurulation, greatly reduces transgene expression. DEAB treatment of embryos at gastrulation phenocopies the embryonic effects of vitamin A deprivation or targeted disruption of the RA synthase retinaldehyde dehydrogenase-2 in other vertebrates. Together these data suggest that the reporter expression we see in zebrafish is dependent upon conserved vertebrate pathways of RA synthesis.

  19. Multifunctional gold nanoparticles for photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Khaing Oo, Maung Kyaw

    As an important and growing branch of photomedicine, photodynamic therapy (PDT) is being increasingly employed in clinical applications particularly for the treatment of skin cancer. This dissertation focuses on the synthesis, characterization and deployment of gold nanoparticles for enhanced PDT of fibrosarcoma cancer cells. We have developed robust strategies and methods in fabrication of gold nanoparticles with positively- and negatively-tethered surface charges by photo-reduction of gold chloride salt using branched polyethyleneimine and sodium citrate respectively. An optimal concentration window of gold salt has been established to yield the most stable and monodispersed gold nanoparticles. 5-aminolevulinic acid (5-ALA), a photosensitizing precursor, has been successfully conjugated on to positively charged gold nanoparticles through electrostatic interactions. The 5-ALA/gold nanoparticle conjugates are biocompatible and have shown to be preferably taken up by cancer cells. Subsequent light irradiation results in the generation of reactive oxygen species (ROS) in cancer cells, leading to their destruction without adverse effects on normal fibroblasts. We have demonstrated for the first time that gold nanoparticles can enhance PDT efficacy by 50% compared to the treatment with 5-ALA alone. Collected evidence has strongly suggested that this enhancement stems from the elevated formation of ROS via the strongly localized electric field of gold nanoparticles. Through single cell imaging using surface-enhanced Raman scattering enabled by the very same gold nanoparticles, we have shown that multifunctionality of gold nanoparticles can be harvested concurrently for biomedical applications in general and for PDT in specific. In other words, gold nanoparticles can be used not only for targeted drug delivery and field-enhanced ROS formation, but also for monitoring cell destructions during PDT. Finally, our COMSOL Multiphysics simulation of the size-dependent electric

  20. [Photodynamic therapy of cholangiocarcinomas].

    PubMed

    Ulstrup, Thomas; Pedersen, Finn Møller

    2013-02-25

    Cholangiocarcinomas (CC) account for approximately 3% of all gastrointestinal cancers with an incidence of about three per 100,000. 70% of CC are perihilar lesions and can be classified according to the Bismuth-Corlette system. At the time of dia-gnosis less than 30% are candidates for complete resection. For nonresectable CC median survival is 4-6 months. Since biliary obstruction is the most common cause of death, biliary stenting has been the standard palliative therapy. Several studies have confirmed that administering photodynamic therapy to perihilar CC improves quality of life and increases median survival time. PMID:23608009

  1. Portable instrument that integrates irradiation with fluorescence and reflectance spectroscopies during clinical photodynamic therapy of cutaneous disease

    NASA Astrophysics Data System (ADS)

    Cottrell, W. J.; Oseroff, A. R.; Foster, T. H.

    2006-06-01

    We report a portable clinical instrument for delivering photodynamic therapy (PDT) while performing noninvasive spectroscopic monitoring in vivo. Using an off-surface probe, the instrument delivers the treatment beam to a user-defined field on the skin and performs reflectance and fluorescence spectroscopies at two regions within this field. The instrument is being used to monitor photosensitizer fluorescence photobleaching, fluorescent photoproduct kinetics, blood volume, and hemoglobin oxygen saturation during a pilot clinical trial of 5-aminolevulinic acid-PDT treatment of superficial basal cell carcinoma (BCC). Protoporphyrin IX and photoproduct fluorescence excited by the 633nm PDT treatment laser is collected between 655 and 800nm. During a series of brief treatment interruptions at programable time points, white light reflectance spectra between 475 and 800nm are acquired. Fluorescence spectra are corrected for the effects of absorption and scattering, informed by the reflectance measurements, and then decomposed into known fluorophore contributions in real time using a robust singular value decomposition fitting routine. Reflectance spectra additionally provide information on blood volume and hemoglobin oxygen saturation. Monitoring blood oxygenation and implicit dose metrics such as photosensitizer photobleaching during PDT allows the improved interpretation of clinical results and is helping to guide the treatment protocol for an anticipated low-irradiance PDT clinical trial of BCC.

  2. In vivo validation of high frequency ultrasound-guided fluorescence tomography system to improve delivery of photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Paliwal, Akshat; Torosean, Sason; Gruber, Josiah; O'Hara, Julia; Hasan, Tayyaba; Pogue, Brian; Maytin, Edward V.

    2011-02-01

    Photodynamic therapy (PDT) for skin cancer is sometimes only partially effective, due to inadequate levels of the fluorescent drug (photosensitizer, PS) and due to heterogeneous distribution of PS within the tissue. To image the PS distribution within skin tumors, we have developed a fluorescence tomography system (FTS) that combines a fluorescence detection array with a high frequency ultrasound (HFUS) transducer. In this paper we describe in vitro and in vivo validation of this new system. The target fluorophore for detection was Protoporphyrin IX (PPIX). Validation experiments were performed in vivo using a subcutaneous tumor model in which A431 tumor-bearing mice were treated with 5-aminolevulinic acid to induce production of PPIX. FTS reconstructions were compared with standard histology and with data from bulk tumor slices imaged ex vivo on a fluorescence scanner. Reconstructed images obtained from the FTS were correlated with the histology and the ex vivo scans, confirming several-fold increases in PPIX fluorescence in the skin and in the tumor relative to the surrounding tissues. Our data demonstrate the feasibility of using the FTS for subsurface imaging of PPIX in skin carcinoma in vivo. Future aims are to use this device for individualized treatment planning, in order to improve overall patient responses to PDT.

  3. Comparative in vivo study of precursors of PpIX (ALA and MAL) used topically in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Rego, Raquel F.; Inada, Natalia M.; Ferreira, Juliana; Araújo-Moreira, Fernando M.; Bagnato, Vanderlei S.

    2009-06-01

    The efficacy of Photodynamic Therapy (PDT) combined with aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) in treatment of cancer has been studied for over ten years. However, there is no established dose for the topical use of these drugs in PDT. The purpose of this study was the comparison of induced PDT response of ALAsense (5-aminolevulinic acid - ALA) and Metvix (methyl aminolevulinate - MAL). Depth of necrosis induced by PDT was analyzed in normal liver of male Wistar rats, using different light doses and topical application of both PpIX precursors - ALA and MAL. PDT was performed with a diode laser at 630 nm with different doses of light (20, 50, 100 and 200 J/cm2), and intensity of 250 mW/cm2. Depth of necrosis analysis was used to calculate the threshold dose for each drug. The results showed that MAL-PDT presented a better response than ALA-PDT, mainly due to formulation differences. Moreover, the ability of the ALA PpIX production was more efficient.

  4. Accelerated migration and invasion of prostate cancer cells after a photodynamic therapy-like challenge: Role of nitric oxide.

    PubMed

    Fahey, Jonathan M; Girotti, Albert W

    2015-09-15

    Employing an in vitro model for 5-aminolevulinic acid (ALA)-based photodynamic therapy (PDT), we recently reported that human prostate cancer PC3 cells rapidly and persistently overexpressed inducible nitric oxide synthase (iNOS) and nitric oxide (NO) after a moderate ALA/light challenge. The upregulated iNOS/NO was shown to play a key role in cell resistance to apoptotic photokilling and also in the dramatic growth spurt observed in surviving cells. In the present study, we found that PC3 cells surviving an ALA/light insult not only proliferated faster than non-stressed controls, but migrated and invaded faster as well, these effects being abrogated by an iNOS inhibitor or NO scavenger. Photostressed prostate DU145 cells exhibited similar behavior. Using in-gel zymography, we showed that PC3 extracellular matrix metalloproteinase-9 (MMP-9) was strongly activated 24 h after ALA/light treatment and that MMP-9 inhibitor TIMP-1 was downregulated, consistent with MMP-9 involvement in enhanced invasiveness. We also observed a photostress-induced upregulation of α6 and β1 integrins, implying their involvement as well. The MMP-9, TIMP-1, and integrin effects were strongly attenuated by iNOS inhibition, confirming NO's role in photostress-enhanced migration/invasion. This study reveals novel, potentially tumor-promoting, side-effects of prostate cancer PDT which may be averted through use of iNOS inhibitors as PDT adjuvants.

  5. Photodynamic therapy with 5-aminoolevulinic acid-induced porphyrins and DMSO/EDTA for basal cell carcinoma

    NASA Astrophysics Data System (ADS)

    Warloe, Trond; Peng, Qian; Heyerdahl, Helen; Moan, Johan; Steen, Harald B.; Giercksky, Karl-Erik

    1995-03-01

    Seven hundred sixty three basal cell carcinomas (BCCs) in 122 patients were treated by photodynamic therapy by 5-aminolevulinic acid (ALA) in cream topically applied, either alone, in combination with dimethyl sulphoxide (DMSO) and ethylenediaminetetraacetic acid disodium salt (EDTA), or with DMSO as a pretreatment. After 3 hours cream exposure 40 - 200 Joules/cm2 of 630 nm laser light was given. Fluorescence imaging of biopsies showed highly improved ALA penetration depth and doubled ALA-induced porphyrin production using DMSO/EDTA. Treatment response was recorded after 3 months. After a single treatment 90% of 393 superficial lesions responded completely, independent of using DMSO/EDTA. In 363 nodulo-ulcerative lesions the complete response rate increased from 67% to above 90% with DMSO/EDTA for lesions less than 2 mm thickness and from 34% to about 50% for lesions thicker than 2 mm. Recurrence rate observed during a follow-up period longer than 12 months was 2 - 5%. PDT of superficial thin BCCs with ALA-induced porphyrins and DMSO/EDTA equals surgery and radiotherapy with respect to cure rate and recurrence. Cosmetic results of ALA-based PDT seemed to be better than those after other therapies. In patients with the nevoid BCC syndrome the complete response rate after PDT was far lower.

  6. Nontumor photodynamic therapy

    NASA Astrophysics Data System (ADS)

    van den Bergh, Hubert

    1997-12-01

    Photodynamic therapy (PDT) has become an approved treatment for different types of cancer in many countries over the last few years. As an example one might mention PDT of the early stages of bronchial or esophageal cancer which have been treated with only about 20% recurrence being observed over several years of follow-up. The low degree of invasion of PDT, as compared to most alternative treatments as well as minimal sided effects, and good repeatability, all speak for this treatment modality. Improved and cheap screening procedures, that are now being developed for the early stage disease, will lead to a more frequent application of PDT for these indications. Detailed studies of PDT showed that certain dyes, after systematic or topical application, could be taken up more in neoplastic tissue as compared to the surrounding normal tissue in the clinical context, thus leading to 'selective' or at least partially selective destruction of the tumor following light application. This selectivity of uptake of certain compounds in hyperproliferative tissue, as well as the observation that PDT can lead to blood vessel stasis, suggested that photodynamic therapy might be worth trying in non-tumor disease. Some of the diseases associated with hyperproliferation and/or neovascularization which are being considered for PDT are listed in table I.

  7. Photodynamic Therapy (PDT): PDT Mechanisms

    PubMed Central

    Allison, Ron R.

    2013-01-01

    Photodynamic therapy (PDT) is a light based therapy used to ablate tumors. As practiced in oncology a photosensitizing agent is applied and then activated by a specific wavelength and energy of light. This light energy in the presence of oxygen will lead to the creation of the photodynamic reaction which is cyto and vasculo toxic. This paper will review the mechanisms of action of PDT and how they may be manipulated to improve clinical outcome in cancer patients. PMID:23422955

  8. Disruption of the Blood–Brain Barrier Following ALA-Mediated Photodynamic Therapy

    PubMed Central

    Hirschberg, Henry; Uzal, Francisco A.; Chighvinadze, David; Zhang, Michelle J.; Peng, Qian; Madsen, Steen J.

    2009-01-01

    Background and Objective Photodynamic therapy (PDT) is a local antineoplastic treatment with the potential for tumor cell specificity. PDT using either hematoporphyrin derivatives or 5-aminolevulinic acid (ALA) has been reported to induce brain edema indicating disruption of the blood–brain barrier (BBB). We have evaluated the ability of ALA-mediated PDT to open the BBB in rats. This will permit access of chemotherapeutic agents to brain tumor cells remaining in the resection cavity wall, but limit their penetration into normal brain remote from the site of illumination. Study Design/Materials and Methods ALA-PDT was performed on non-tumor bearing inbred Fischer rats at increasing fluence levels. Contrast T1-weighted high field (3 T) magnetic resonance imaging (MRI) scans were used to monitor the degree of BBB disruption which could be inferred from the intensity and volume of the contrast agent visualized. Results PDT at increasing fluence levels between 9 and 26 J demonstrated an increasing contrast flow rate. A similar increased contrast volume was observed with increasing fluence rates. The BBB was found to be disrupted 2 hours following PDT and 80–100% restored 72 hours later at the lowest fluence level. No effect on the BBB was observed if 26 J of light was given in the absence of ALA. Conclusion ALA-PDT was highly effective in opening the BBB in a localized region of the brain. The degradation of the BBB was temporary in nature at fluence levels of 9 J, opening rapidly following treatment and significantly restored during the next 72 hours. No signs of tissue damage were seen on histological sections at this fluence level. However, higher fluences did demonstrate permanent tissue changes localized in the immediate vicinity of the light source. PMID:18798293

  9. Fluorescence image-guided photodynamic therapy of cancer cells using a scanning fiber endoscope

    NASA Astrophysics Data System (ADS)

    Woldetensae, Mikias H.; Kirshenbaum, Mark R.; Kramer, Greg M.; Zhang, Liang; Seibel, Eric J.

    2013-03-01

    A scanning fiber endoscope (SFE) and the cancer biomarker 5-aminolevulinic acid (5-ALA) were used to fluorescently detect and destroy superficial cancerous lesions, while experimenting with different dosimetry levels for concurrent or sequential imaging and laser therapy. The 1.6-mm diameter SFE was used to fluorescently image a confluent monolayer of A549 human lung cancer cells from culture, previously administered with 5 mM solution of 5-ALA for 4 hours. Twenty hours after therapy, cell cultures were stained to distinguish between living and dead cells using a laser scanning confocal microscope. To determine relative dosimetry for photodynamic therapy (PDT), 405-nm laser illumination was varied from 1 to 5 minutes with power varying from 5 to 18 mW, chosen to compare equal amounts of energy delivered to the cell culture. The SFE produced 500-line images of fluorescence at 15 Hz using the red detection channel centered at 635 nm. The results show that PDT of A549 cancer cell monolayers using 405nm light for imaging and 5-ALAinduced PpIX therapy was possible using the same SFE system. Increased duration and power of laser illumination produced an increased area of cell death upon live/dead staining. The ultrathin and flexible SFE was able to direct PDT using wide-field fluorescence imaging of a monolayer of cultured cancer cells after uptaking 5-ALA. The correlation between light intensity and duration of PDT was measured. Increased length of exposure and decreased light intensity yields larger areas of cell death than decreased length of exposure with increased light intensity.

  10. Tumor cell hyperresistance to photodynamic killing arising from nitric oxide preconditioning

    NASA Astrophysics Data System (ADS)

    Niziolek-Kierecka, Magdalena; Korytowski, Witold; Girotti, Albert W.

    2007-02-01

    Relatively little is known about how nitric oxide (NO) generated by tumor vascular cells or tumor cells themselves might affect the outcome of photodynamic therapy (PDT). Using a breast tumor epithelial line (COH-BR1) metabolically sensitized with protoporphyrin IX (PpIX) by pre-treating with 5-aminolevulinic acid (ALA), we have recently shown that NO from chemical donors can elicit both an immediate (NO-now) and delayed (NO-then) hyperresistance to photokilling. Cell death was mainly apoptotic when PpIX was confined to mitochondria, but mainly necrotic when it was allowed to diffuse to the cell periphery. We found that NO-now operates primarily by scavenging lipid-derived free radicals, whereas NO-then "preconditions" cells by some other mechanism. In addressing this, we have used a biologically relevant NO donor/tumor target model, viz. RAW 264.7 macrophages grown on microporous membrane inserts and COH-BR1 cells grown in culture plate wells. The RAW cells were activated with lipopolysaccharide, and 15 h later (when NO output was ~ 2 μM/h) placed over the tumor cells for 20 h, after which the latter were ALA-treated and then irradiated. Prior exposure to activated RAW macrophages reduced tumor cell photokilling by >50 %. This effect was completely lost when the RAW cells were pre-treated with the nitric oxide synthase inhibitor L-NAME, confirming that NO was involved in the hyperresistance. Results from other experiments suggest that heme oxygenase-1 and ferritin play a role in the preconditioning effect described. These studies provide new insights into how NO might modulate PDT efficacy.

  11. Photosensitization and mechanism of cytotoxicity induced by the use of ALA derivatives in photodynamic therapy

    PubMed Central

    Casas, A; Fukuda, H; Di Venosa, G; Batlle, A

    2001-01-01

    The use of more lipophilic derivatives of 5-aminolevulinic acid (ALA) is expected to have better diffusing properties, and after conversion into the parent ALA, to reach a higher protoporphyrin IX (PPIX) formation rate, thus improving the efficacy of topical photodynamic therapy (PDT). Here we have analysed the behaviour of 3 ALA derivatives (ALA methyl-ester, hexyl ester and a 2-sided derivative) regarding PPIX formation, efficiency in photosensitizing cells and mechanism of cellular death. The maximum amount of porphyrins synthesized from 0.6 mM ALA was 47 ± 8 ng/105 cells. The same amount was formed by a concentration 60-fold lower of hexyl-ALA and 2-fold higher of methyl-ALA. The 2-sided derivative failed to produce PPIX accumulation. Applying a 0.6 J cm−2 light dose, cell viability decreased to 50%. With the 1.5 J cm−2 light dose, less than 20% of the cells survive, and higher light doses produced nearly total cell killing. Comparing the PPIX production and the induced phototoxicity, the more the amount of porphyrins, the greater the cellular killing, and PPIX formed from either ALA or ALA-esters equally sensitize the cells to photoinactivation. ALA-PDT treated cells exhibited features of apoptosis, independently on the pro-photosensitizer employed. ALA-PDT can be improved with the use of ALA derivatives, reducing the amount of ALA necessary to induce efficient photosensitization. ©2001 Cancer Research Campaign http://www.bjcancer.com PMID:11461090

  12. Neurotransmitter transporter family including SLC6A6 and SLC6A13 contributes to the 5-aminolevulinic acid (ALA)-induced accumulation of protoporphyrin IX and photodamage, through uptake of ALA by cancerous cells.

    PubMed

    Tran, Tai Tien; Mu, Anfeng; Adachi, Yuka; Adachi, Yasushi; Taketani, Shigeru

    2014-01-01

    δ-Aminolevulinic acid (ALA)-induced protoporphyrin accumulation is widely used in the treatment of cancer, as photodynamic therapy (PDT). To clarify the mechanisms of ALA uptake by tumor cells, we have examined the ALA-induced accumulation of protoporphyrin by the treatment of colon cancer DLD-1 and epithelial cancer HeLa cells with γ-aminobutyric acid (GABA)-related compounds. When the cells were treated with GABA, taurine and β-alanine, the level of protoporphyrin was decreased, suggesting that plasma membrane transporters involved in the transport of neurotransmitters contribute to the uptake of ALA. By transfection with neurotransmitter transporters SLC6A6, SLC6A8 and SLC6A13 cDNA, the ALA- and ALA methylester-dependent accumulation of protoporphyrin markedly increased in HEK293T cells, dependent on an increase in the uptake of ALA. When ALA-treated cells were exposed to white light, the extent of photodamage increased in SLC6A6- and SLC6A13-expressing cells. Conversely, knockdown of SLC6A6 or SLC6A13 with siRNAs in DLD-1 and HeLa cells decreased the ALA-induced accumulation. The expression of SLC6A6 and SLC6A13 was found in some cancer cell lines. Immunohistochemical studies revealed that the presence of these transporters was elevated in colon cancerous cells. These results indicated that neurotransmitter transporters including SLC6A6 and SLC6A13 mediate the uptake of ALA and can play roles in the enhancement of ALA-induced accumulation of protoporphyrin in cancerous cells.

  13. Hyperbaric oxygen therapy augments the photodynamic action of methylene blue against bacteria in vitro

    NASA Astrophysics Data System (ADS)

    Bisland, S. K.; Dadani, F. N.; Chien, C.; Wilson, B. C.

    2007-02-01

    Photodynamic therapy (PDT) entails the combination of photosensitizer and light to generate cytotoxic molecules that derive from molecular oxygen (O II). The presence of sufficient O II within the target tissues is critical to the efficiency of PDT. This study investigates the use of hyperbaric oxygen therapy in combination with PDT (HOTPDT) to augment the photodynamic action of methylene blue (MB) or 5-aminolevulinic acid (ALA) against gram positive and gram negative bacterial strains in vitro. Staphylococcus aureus or Pseudomonas aeruginosa were grown in trypticase soy broth as planktonic cultures (~10 8/mL) or as established biofilms in 48 well plates (3 days old) at 32°C. Dark toxicity and PDT response in the presence or absence of HOT (2 atmospheres, 100% O II for 30, 60 or 120 min) was established for both MB (0-0.1 mM) and ALA (0- 1 mM) for a range of incubation times. The number of surviving colonies (CFU/mL) was plotted for each treatment groups. Light treatments (5, 10, 20 or 30 J/cm2) were conducted using an array of halogen bulbs with a red filter providing 90% transmittance over 600-800 nm at 21 mW/cm2. HOT increased the dark toxicity of MB (30 min, 0.1 mM) from < 0.2 log cell kill to 0.5 log cell kill. Dark toxicity of ALA (4 hr, 1 mM) was negligible and did not increase with HOT. For non-dark toxic concentrations of MB or ALA, (0.05 mM and 1 mM respectively) HOT-PDT enhanced the antimicrobial effect of MB against Staphylococcus aureus in culture by >1 and >2 logs of cell kill (CFU/mL) at 5 and 10 J/cm2 light dose respectively as compared to PDT alone. HOT-PDT also increased the anti-microbial effects of MB against Staphylococcus aureus biofilms compared to PDT, albeit less so (> 2 logs) following 10 J/cm2 light dose. Anti-microbial effects of PDT using ALA were not significant for either strain with or without HOT. These data suggest that HOTPDT may be useful for improving the PDT treatment of bacterial infections.

  14. Photodynamic tumor therapy and on-line fluorescence spectroscopy after ALA administration using 633-nm light as therapeutic and fluorescence excitation radiation

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten; Kienle, Alwin; Boehncke, Wolf-Henning; Kaufmann, Roland; Rueck, Angelika C.; Meier, Thomas H.; Steiner, Rudolf W.

    1994-09-01

    Photodynamic therapy (PDT) and on-line fluorescence spectroscopy were carried out on human tumors after 5-aminolevulinic acid (ALA) administration using 633-nm light of a dye laser as therapeutic radiation and as fluorescence excitation radiation. This has the advantages of (1) enabling use of one laser for PDT and fluorescence diagnosis only, (2) enabling the possibility of on-line fluorescence measurements, and (3) exciting protoporphyrin molecules in deep tissue layers. Monte Carlo calculations were carried out to determine excitation and fluorescence phonon distribution in case of red and violet excitation radiation. The results show the possibility of depth-resolved measurements on the fluorophore distribution by variation of excitation wavelength. The high penetration depth of 633-nm radiation results in a higher ratio of the 700-nm protoporphyrin fluorescence of the xenotransplanted tumor It to Is compared with 407-nm excitation. No values greater than 1 for the ratio I/Is were found, however, in case of intravenous ALA injection even for red excitation. Therefore, a large amount of ALA will be metabolized in the skin and can cause photosensitivity of the patient when applied systematically. In contrast, protoporphyrin fluorescence limited to the pretreated skin area was detected in case of topically applied ALA to patients with mycosis funcoides and erythroplasy of Queyrat. The influence of remitted excitation light and of the spontaneous radiation from the laser as well as the possible excitation of foodbased degradation products of chlorophyll has to be considered in high-sensitivity fluorescence measurements.

  15. In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints

    PubMed Central

    Mallidi, Srivalleesha; Mai, Zhiming; Rizvi, Imran; Hempstead, Joshua; Arnason, Stephen; Celli, Jonathan; Hasan, Tayyaba

    2015-01-01

    Abstract. In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs. PMID:25909707

  16. Immobilization of ALA-Zn(II) Coordination Polymer Pro-photosensitizers on Magnetite Colloidal Supraparticles for Target Photodynamic Therapy of Bladder Cancer.

    PubMed

    Tan, Jing; Sun, Chuanyu; Xu, Ke; Wang, Changchun; Guo, Jia

    2015-12-16

    5-Aminolevulinic acid (ALA) is a widely used photodynamic therapy (PDT) prodrug in the clinic. It can be metalized to the photosensitizer PpIX, which produces toxic singlet oxygen to kill cancer cells upon visible light irradiation. Herein, a core/shell-structured vehicle is designed to comprise magnetite colloidal supraparticles (MCSPs) as cores and ALA-Zn(II) coordination polymers as shells (Fe3O4@ALA-Zn(II) ) for target pro-photosensitizer delivery. The coordination polymers with 2D layered structures are locally deposited on the MCSPs by the complexation of the ALA and Zn(II) ions, and are readily controlled by varying the feed precursors and reaction temperatures. The maximum conjugated ALA amount is up to 17%. The Fe3O4@ALA-Zn(II) microspheres exhibit pH-sensitive release of ALA in acidic environment and rapid magnetic responsiveness. Cytotoxicity results demonstrate that Fe3O4@ALA-Zn(II) shows a significant inhibitory effect to T24 cells and is nontoxic to 293T normal cells as exposed to the 630 nm visible light for a very short time, which may due to the selective accumulation of ALA-induced PpIX in T24 cancer cells. Compared to the ALA used alone, the coordination polymer form is more efficient because of the bioactivity of incorporated Zn ions despite underlying the same apoptosis mechanism as ALA agent.

  17. The Effect of Coatings on the Affinity of Lanthanide Nanoparticles to MKN45 and HeLa Cancer Cells and Improvement in Photodynamic Therapy Efficiency.

    PubMed

    Sawamura, Takashi; Tanaka, Tatsumi; Ishige, Hiroyuki; Iizuka, Masayuki; Murayama, Yasutoshi; Otsuji, Eigo; Ohkubo, Akihiro; Ogura, Shun-Ichiro; Yuasa, Hideya

    2015-01-01

    An improvement in photodynamic therapy (PDT) efficiency against a human gastric cancer cell line (MKN45) with 5-aminolevulinic acid (ALA) and lanthanide nanoparticles (LNPs) is described. An endogenous photosensitizer, protoporphyrin IX, biosynthesized from ALA and selectively accumulated in cancer cells, is sensitizable by the visible lights emitted from up-conversion LNPs, which can be excited by a near-infrared light. Ten kinds of surface modifications were performed on LNPs, NaYF₄(Sc/Yb/Er) and NaYF₄(Yb/Tm), in an aim to distribute these irradiation light sources near cancer cells. Among these LNPs, only the amino-functionalized LNPs showed affinity to MKN45 and HeLa cancer cells. A PDT assay with MKN45 demonstrated that amino-modified NaYF₄(Sc/Yb/Er) gave rise to a dramatically enhanced PDT effect, reaching almost perfect lethality, whereas NaYF₄(Yb/Tm)-based systems caused little improvement in PDT efficiency. The improvement of PDT effect with the amino-modified NaYF₄(Sc/Yb/Er) is promising for a practical PDT against deep cancer cells that are reachable only by near-infrared lights. PMID:26389895

  18. In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints

    NASA Astrophysics Data System (ADS)

    Mallidi, Srivalleesha; Mai, Zhiming; Rizvi, Imran; Hempstead, Joshua; Arnason, Stephen; Celli, Jonathan; Hasan, Tayyaba

    2015-04-01

    In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs.

  19. In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints.

    PubMed

    Mallidi, Srivalleesha; Mai, Zhiming; Rizvi, Imran; Hempstead, Joshua; Arnason, Stephen; Celli, Jonathan; Hasan, Tayyaba

    2015-04-01

    In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs.

  20. In vivo evaluation of battery-operated light-emitting diode-based photodynamic therapy efficacy using tumor volume and biomarker expression as endpoints.

    PubMed

    Mallidi, Srivalleesha; Mai, Zhiming; Rizvi, Imran; Hempstead, Joshua; Arnason, Stephen; Celli, Jonathan; Hasan, Tayyaba

    2015-04-01

    In view of the increase in cancer-related mortality rates in low- to middle-income countries (LMIC), there is an urgent need to develop economical therapies that can be utilized at minimal infrastructure institutions. Photodynamic therapy (PDT), a photochemistry-based treatment modality, offers such a possibility provided that low-cost light sources and photosensitizers are available. In this proof-of-principle study, we focus on adapting the PDT light source to a low-resource setting and compare an inexpensive, portable, battery-powered light-emitting diode (LED) light source with a standard, high-cost laser source. The comparison studies were performed in vivo in a xenograft murine model of human squamous cell carcinoma subjected to 5-aminolevulinic acid-induced protoporphyrin IX PDT. We observed virtually identical control of the tumor burden by both the LED source and the standard laser source. Further insights into the biological response were evaluated by biomarker analysis of necrosis, microvessel density, and hypoxia [carbonic anhydrase IX (CAIX) expression] among groups of control, LED-PDT, and laser-PDT treated mice. There is no significant difference in the percent necrotic volume and CAIX expression in tumors that were treated with the two different light sources. These encouraging preliminary results merit further investigations in orthotopic animal models of cancers prevalent in LMICs. PMID:25909707

  1. Photodynamic therapy inhibit Fibroblast Growth Factor-10 induced keratinocyte differentiation and proliferation through ROS in Fibroblast Growth Factor Receptor-2b pathway

    PubMed Central

    Gozali, Maya Valeska; Yi, Fei; Zhang, Jia-an; Liu, Juan; Wu, Hong-jin; Xu, Yang; Luo, Dan; Zhou, Bing-rong

    2016-01-01

    5-aminolevulinic acid-photodynamic therapy (ALA-PDT) is known to be effective in several skin diseases such as acne, actinic keratoses, condyloma acuminata. However, some detailed mechanisms of ALA-PDT to treat these skin diseases still remain elusive. In this study, we aimed to investigate mechanism of ALA-PDT in in-vitro and in-vivo models. For in vitro, we use human keratinocyte cell line (HaCaT) cells. CCK-8 was used to detect cell proliferation activity, immunofluorescence and western blotting method to detect the content of keratin (K)1, K6, K16, protein kinase C (PKC), fibroblast growth factor receptor-2b (FGFR2b) protein, ELISA and RT-PCR to detect expression of interleukin (IL) 1α in the cell supernatant, and detect reactive oxygen species (ROS). For in vivo, we use 20 rabbits to induce hyperkeratosis acne model in their ear. Dermatoscope was used to see follicle hyperkeratosis and skin biopsy to analyze histology and immunohistochemical of PKC, FGFR2b, K1, K6 and K16. Results from this study suggest that ROS stimulated by ALA-PDT lead to inhibition of FGFR2b pathway in PKC downstream to cause reduction of IL1α expression, and eventually, keratinocytes differentiation and proliferation. Our data thus reveal a treatment mechanism of ALA-PDT underlying hyperkeratosis related dermatoses. PMID:27273653

  2. Studies on Lewis acid-mediated intramolecular cyclization reactions of allene-ene systems.

    PubMed

    Hiroi, K; Watanabe, T; Tsukui, A

    2000-03-01

    The Lewis acid-mediated reactions of allene-ene compounds, derived from 3-methylcitronellal or dimethyl malonate, were carried out using various Lewis acids such as ethylaluminum dichloride, diethylaluminum chloride, titanium chloride, zinc chloride etherate, or boron trifluoride etherate, affording unexpectedly intramolecular [2+2]cycloaddition products under some particular reaction conditions without any formation of intramolecular ene reaction products.

  3. Photodynamic therapy using hemagglutinating virus of Japan envelope (HVJ-E): a novel therapeutic approach for the treatment of hormone antagonistic prostate cancer

    NASA Astrophysics Data System (ADS)

    Inai, Mizuho; Yamauchi, Masaya; Honda, Norihiro; Hazama, Hisanao; Tachikawa, Shoji; Nakamura, Hiroyuki; Nishida, Tomoki; Yasuda, Hidehiro; Kaneda, Yasufumi; Awazu, Kunio

    2015-03-01

    Traditional treatment options for prostate cancer are insufficient to cure advanced drug-resistant prostate cancer. Thus, as an alternative form of cancer therapy, photodynamic therapy (PDT) has become the main subject of intense investigation as a possible treatment modality. In this study, ultraviolet-inactivated viral vector, called hemagglutinating virus of Japan envelope (HVJ-E) was utilized to establish an effective delivery system for photosensitizer. Lipidated protoporphyrin IX (PpIX lipid) was inserted in HVJ-E by centrifugation to create a new drug delivering system that allows selective accumulation of photosensitizers in cancer cells. To study in vitro drug release mechanism of porphyrus envelope, the ultra-high voltage electron microscope tomography was applied. Next, to evaluate the photodynamic efficiency of porphyrus envelope for hormone antagonistic prostate cancer cells (PC-3), uptake of porphyrus envelope derived PpIX lipid and PpIX induced from exogenously administered precursor of 5-aminolevulinic acid hydrochloride (5-ALA) were compared by measuring fluorescence intensity of PpIX. Finally, to evaluate the efficacy of porphyrus envelope-PDT, laser light at a wavelength of 405 nm was irradiated to PC-3 cells. As a result, incorporation of porphyrus envelope-derived PpIX lipid occurred via membrane fusion, giving the highest fluorescence intensity when compared to 5-ALA-induced PpIX. Also, results from PDT experiment revealed the 28.6 × 103-fold and 206-fold increase in therapeutic efficacy when compared to those of PDT using 5-ALA induced PpIX and PpIX lipid, respectively. Our findings suggest how porphyrus envelope can induce efficient accumulation of PpIX lipid, which can enhance the therapeutic efficacy of PDT against hormone antagonistic prostate cancer.

  4. Photodynamic therapy for basal cell carcinoma.

    PubMed

    Fargnoli, Maria Concetta; Peris, Ketty

    2015-11-01

    Topical photodynamic therapy is an effective and safe noninvasive treatment for low-risk basal cell carcinoma, with the advantage of an excellent cosmetic outcome. Efficacy of photodynamic therapy in basal cell carcinoma is supported by substantial research and clinical trials. In this article, we review the procedure, indications and clinical evidences for the use of photodynamic therapy in the treatment of basal cell carcinoma.

  5. Photodynamic therapy--aspects of pain management.

    PubMed

    Fink, Christine; Enk, Alexander; Gholam, Patrick

    2015-01-01

    Topical photodynamic therapy (PDT) is a highly effective and safe treatment method for actinic keratoses with an excellent cosmetic outcome and is commonly used for the therapy of large areas of photodamaged skin with multiple clinically manifest and subclinical lesions. However, the major drawback of photodynamic therapy is the pain experienced during the treatment that can be intense and sometimes even intolerable for patients, requiring interruption or termination of the process. Several strategies for controlling pain during photodynamic therapy have been studied but few effective methods are currently available. Therefore, this review puts the spotlight on predictors on pain intensity and aspects of pain management during photodynamic therapy. PMID:25640485

  6. Light Fractionation Significantly Increases the Efficacy of Photodynamic Therapy Using BF-200 ALA in Normal Mouse Skin

    PubMed Central

    de Bruijn, Henriëtte S.; Brooks, Sander; van der Ploeg-van den Heuvel, Angélique; ten Hagen, Timo L. M.; de Haas, Ellen R. M.; Robinson, Dominic J.

    2016-01-01

    Background Light fractionation significantly increases the efficacy of 5-aminolevulinic acid (ALA) based photodynamic therapy (PDT) using the nano-emulsion based gel formulation BF-200. PDT using BF-200 ALA has recently been clinically approved and is under investigation in several phase III trials for the treatment of actinic keratosis. This study is the first to compare BF-200 ALA with ALA in preclinical models. Results In hairless mouse skin there is no difference in the temporal and spatial distribution of protoporphyrin IX determined by superficial imaging and fluorescence microscopy in frozen sections. In the skin-fold chamber model, BF-200 ALA leads to more PpIX fluorescence at depth in the skin compared to ALA suggesting an enhanced penetration of BF-200 ALA. Light fractionated PDT after BF-200 ALA application results in significantly more visual skin damage following PDT compared to a single illumination. Both ALA formulations show the same visual skin damage, rate of photobleaching and change in vascular volume immediately after PDT. Fluorescence immunohistochemical imaging shows loss of VE-cadherin in the vasculature at day 1 post PDT which is greater after BF-200 ALA compared to ALA and more profound after light fractionation compared to a single illumination. Discussion The present study illustrates the clinical potential of light fractionated PDT using BF-200 ALA for enhancing PDT efficacy in (pre-) malignant skin conditions such as basal cell carcinoma and vulval intraepithelial neoplasia and its application in other lesion such as cervical intraepithelial neoplasia and oral squamous cell carcinoma where current approaches have limited efficacy. PMID:26872051

  7. Cytoprotective signaling associated with nitric oxide upregulation in tumor cells subjected to photodynamic therapy-like oxidative stress.

    PubMed

    Bhowmick, Reshma; Girotti, Albert W

    2013-04-01

    Photodynamic therapy (PDT) employs photoexcitation of a sensitizer to generate tumor-eradicating reactive oxygen species. We recently showed that irradiating breast cancer COH-BR1 cells after treating with 5-aminolevulinic acid (ALA, a pro-sensitizer) resulted in rapid upregulation of inducible nitric oxide (NO) synthase (iNOS). Apoptotic cell killing was strongly enhanced by an iNOS inhibitor (1400W), iNOS knockdown (kd), or a NO scavenger, suggesting that NO was acting cytoprotectively. Stress signaling associated with these effects was examined in this study. ALA/light-stressed COH-BR1 cells, and also breast adenocarcinoma MDA-MB-231 cells, mounted an iNOS/NO-dependent resistance to apoptosis that proved to be cGMP-independent. Immunocytochemistry and subcellular Western analysis of photostressed COH-BR1 cells revealed a cytosol-to-nucleus translocation of NF-κB which was negated by the NF-κB activation inhibitor Bay11. Bay11 also enhanced apoptosis and prevented iNOS induction, consistent with NF-κB involvement in the latter. JNK and p38 MAP kinase inhibitors suppressed apoptosis, implicating these kinases in death signaling. Post-irradiation extent and duration of JNK and p38 phosphorylation were dramatically elevated by 1400 W or iNOS-kd, suggesting that these activations were suppressed by NO. Regarding pro-survival stress signaling, rapid activation of Akt was unaffected by 1400 W, but prevented by Wortmannin, which also enhanced apoptosis. Thus, a link between upstream Akt activation and iNOS induction was apparent. Furthermore, p53 protein expression under photostress was elevated by iNOS-kd, whereas robust Survivin induction was abolished, consistent with p53 and Survivin being negatively and positively regulated by NO, respectively. Collectively, these findings enhance our understanding of cytoprotective signaling associated with photostress-induced NO and suggest iNOS inhibitor-based approaches for improving PDT efficacy.

  8. Intensified oxidative and nitrosative stress following combined ALA-based photodynamic therapy and local hyperthermia in rat tumors.

    PubMed

    Frank, Juergen; Lambert, Christine; Biesalski, Hans Konrad; Thews, Oliver; Vaupel, Peter; Kelleher, Debra K

    2003-12-20

    Oxidative stress-related changes in tumors upon localized hyperthermia (HT), 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) and their combination (ALA+HT) were examined after the observation that the antitumor effects of ALA-PDT could be significantly enhanced upon simultaneous application of HT. Rats bearing s.c. DS-sarcomas (0.6-1.0 ml) on the hind foot dorsum were anesthetized and underwent one of the following treatments: (i) ALA-PDT (375 mg/kg 5-ALA i.v.); (ii) localized HT, 43 degrees C for 60 min; (iii) combined ALA-PDT and HT [=ALA+HT]. Appropriate control experiments were also performed. After treatment, tumors were excised and rapidly frozen for later analysis of nitrosative stress (protein nitration), apoptotic events (TUNEL, caspase activation, DNA and RNA fragmentation), expression of heat shock proteins (hsp70 and HO-1), glutathione (GSH) levels and glutathione peroxidase (GPx) activity. Protein nitration was found to increase upon treatment, being especially pronounced in the ALA+HT group, and could partially be related to areas surrounding microvessels. The extent of nitrosative stress also correlated well with the appearance of the markers of apoptosis and the inhibition of in vivo tumor growth as seen in a previous study. GSH levels decreased upon treatment, the reduction being most prominent in the ALA-PDT and ALA+HT groups. GPx activity, however, showed a significant decrease only in the ALA-PDT group. Whereas hsp70 expression increased upon HT, ALA-PDT caused a decrease, and these opposing effects were nullified with ALA+HT. The results obtained point to a number of cellular mechanisms-including effects on cellular defense mechanisms and an abrogation of the heat shock defense mechanism-that may interact to achieve the potentiated tumor response rate seen in vivo upon combined treatment. PMID:14601053

  9. Cytoprotective Signaling Associated with Nitric Oxide Upregulation in Tumor Cells Subjected to Photodynamic Therapy-like Oxidative Stress

    PubMed Central

    Bhowmick, Reshma; Girotti, Albert W.

    2012-01-01

    Photodynamic therapy (PDT) employs photoexcitation of a sensitizer to generate tumor-eradicating reactive oxygen species. We recently showed that irradiating breast cancer COH-BR1 cells after treating with 5-aminolevulinic acid (ALA, a pro-sensitizer) resulted in rapid upregulation of inducible nitric oxide (NO) synthase (iNOS). Apoptotic cell killing was strongly enhanced by an iNOS inhibitor (1400W), iNOS knockdown (kd), or a NO scavenger, suggesting that NO was acting cytoprotectively. Stress signaling associated with these effects was examined in this study. ALA/light-stressed COH-BR1 cells, and also breast adenocarcinoma MDA-MB-231 cells, mounted an iNOS/NO-dependent resistance to apoptosis that proved to be cGMP-independent. Immunocytochemistry and subcellular Western analysis of photostressed COH-BR1 cells revealed a cytosol-to-nucleus translocation of NF-κB which was negated by the NF-κB activation inhibitor Bay11. Bay11 also enhanced apoptosis and prevented iNOS induction, consistent with NF-κB involvement in the latter. JNK and p38 MAP kinase inhibitors suppressed apoptosis, implicating these kinases in death signaling. Post-irradiation extent and duration of JNK and p38 phosphorylation were dramatically elevated by 1400W or iNOS-kd, suggesting that these activations were suppressed by NO. Regarding pro-survival stress signaling, rapid activation of Akt was unaffected by 1400W, but prevented by Wortmannin, which also enhanced apoptosis. Thus, a link between upstream Akt activation and iNOS induction was apparent. Furthermore, p53 protein expression under photostress was elevated by iNOS-kd, whereas robust Survivin induction was abolished, consistent with p53 and Survivin being negatively and positively regulated by NO, respectively. Collectively, these findings enhance our understanding of cytoprotective signaling associated with photostress-induced NO and suggest iNOS inhibitor-based approaches for improving PDT efficacy. PMID:23261943

  10. Enhancement and optimization of PpIX-based photodynamic therapy of skin cancer: translational studies from bench to clinic

    NASA Astrophysics Data System (ADS)

    Maytin, Edward V.; Anand, Sanjay; Baran, Christine; Honari, Golara; Lohser, Sara; Kyei, Angela; Bailin, Philip; Pogue, Brian W.

    2009-02-01

    Nonmelanoma skin carcinomas are the most common of all human cancers. Photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA) has been used to treat these tumors, but has shown variable results. We are pursuing a multifaceted approach toward optimizing tumor responsiveness. First, a new paradigm is being developed in which tumors are pretreated with differentiation-inducing agents, e.g. methotrexate or Vitamin D, to enhance synthesis of protoporphyrin IX (PpIX) and improve tumor cell killing upon exposure to 635 nm light. This principle was first elucidated in cell culture studies, and has now been shown to hold true for murine skin tumors, and for a human subcutaneous tumor model (A431 cells injected in nude mice). Clinical trials to test methotrexate and Vitamin D as augmenting agents for ALA-PDT of nonmelanoma skin cancer are being designed. Second, better methods to measure PpIX in patients' skin tumors in real time are being developed. In a clinical study to measure PpIX in patients with dysplastic skin lesions, in vivo fluorescence dosimetry was used to measure the accumulation of PpIX over time, and revealed that intralesional PpIX may reach clinically-useful levels earlier than previously thought for the treatment of actinic keratoses. In a second clinical study to examine depth of PpIX production in nonmelanoma skin cancer, the depth of PpIX within BCC tumors was found at relatively deep levels (>1 mm) in some tumor nests, but not in others. Production of PpIX in deep squamous cell carcinoma was very low. In summary, molecular approaches such as differentiation therapy to enhance ALA-PDT for individual patients may ultimately be needed to help to improve skin cancer responses to this modality.

  11. 5-ALA Fluorescence in Native Pituitary Adenoma Cell Lines: Resection Control and Basis for Photodynamic Therapy (PDT)?

    PubMed Central

    Poeschke, Stephan; Greve, Burkhard; Prevedello, Daniel; Santacroce, Antonio; Stummer, Walter; Senner, Volker

    2016-01-01

    Objective: Pituitary adenomas (PA), especially invasive ones, are often not completely resectable. Usage of 5-aminolevulinic acid (5-ALA) for fluorescence guided surgery could improve the rate of total resection and, additionally, open the doors for photodynamic therapy (PDT) in case of unresectable or partially resected PAs. The aim of this study was to investigate the uptake of 5-ALA and the effect of 5-ALA based PDT in cell lines. Methods: GH3 and AtT-20 cell lines were incubated with different concentrations of 5-ALA, protoporphyrin IX (PPIX) fluorescence was measured by flow cytometry and fluorescencespectrometry. WST-1 assays were performed to determine the surviving fraction of cells after PDT. PPIX fluorescence intensities and PDT effect of the pituitary adenoma cells were compared to U373MG, a well-known glioblastoma cell line. Results: Both cell lines showed a 5-ALA dependent intracellular PPIX fluorescence. Significant differences after 24hrs of incubation were observed in AtT-20 cells in comparison to GH3. Regardless of the incubation or metabolism time, there was a proliferation inhibiting effect after PDT, with no statistical significance. Conclusion: Since GH3 cells showed a heterogenous uptake of 5-ALA in the flow cytometry profile, but not constantly high concentrations they might have a 5-ALA efflux mechanism, which still needs to be determined. In the case of AtT-20, the cells might need a longer time for the uptake due to their size or slow metabolism. We showed that the different cell lines have different uptake and metabolism mechanisms, which needs to be further investigated. The general uptake of 5-ALA allows the possibility of resection control and PDT for pituitary adenomas. But, the role of PDT for unresectable pituitary adenomas deserves further investigations. PMID:27583461

  12. Preclinical in vitro and in vivo studies to examine the potential use of photodynamic therapy in the treatment of osteomyelitis

    NASA Astrophysics Data System (ADS)

    Bisland, Stuart K.; Chien, Claudia; Wilson, Brian C.; Burch, Shane

    2005-04-01

    Osteomyelitis can lead to severe morbidity and even death resulting from an acute or chronic inflammation of the bone and contiguous structures due to fungal or bacterial infection. Incidence approximates 1 in 1,000 neonates and 1 in 5,000 children in the United States annually and increases up to 0.36% and 16% in adults with diabetes or sickle cell anaemia, respectively. Current regiments of treatment include antibiotics and/or surgery. However, the increasing number of antibiotic resistant pathogens suggests that alternate strategies are required. We are investigating photodynamic therapy (PDT) as one such alternate treatment for osteomyelitis using a bioluminescent strain of biofilm-producing staphylococcus aureus (SA) grown onto kirschner wires (K-wire). SA-coated K-wires were exposed to methylene blue (MB) or 5-aminolevulinic acid (ALA)-mediated PDT either in vitro or following implant into the tibial medullary cavity of Sprague-Dawley rats. The progression of SA biofilm was monitored non-invasively using bioluminescence and expressed as a percentage of the signal for each sample immediately prior to treatment. SA infections were subject to PDT 10 days post inoculation. Treatment comprised administration of ALA (300 mg/Kg) intraperitoneally followed 4 hr later by light (635 +/- 10 nm; 38 or 75 J/cm2) delivered transcutaneously via an optical fiber placed onto the tibia. In vitro, MB and ALA displayed similar cell kill with >= 4log10 cell kill. In vivo, ALA-mediated PDT inhibited biofilm implants in bone. These results confirm that MB or ALA-mediated PDT have potential to treat SA cultures grown in vitro or in vivo using an animal model of osteomyelitis.

  13. Photodynamic Diagnosis and Therapy of Cancer

    SciTech Connect

    Subiel, Anna

    2010-01-05

    This paper gives brief information about photodynamic method used in diagnosis and therapy for cancer and other human body disorders. In particular it concentrates on detection and analysis of fluorescent dye, i.e. protoporphyrin IX (PpIX) and its two-photon excitation (TPE) process, which offers photodynamic method many fascinating possibilities.

  14. Photodynamic therapy in endodontics: a literature review.

    PubMed

    Trindade, Alessandra Cesar; De Figueiredo, José Antônio Poli; Steier, Liviu; Weber, João Batista Blessmann

    2015-03-01

    Recently, several in vitro and in vivo studies demonstrated promising results about the use of photodynamic therapy during root canal system disinfection. However, there is no consensus on a standard protocol for its incorporation during root canal treatment. The purpose of this study was to summarize the results of research on photodynamic therapy in endodontics published in peer-reviewed journals. A review of pertinent literature was conducted using the PubMed database, and data obtained were categorized into sections in terms of relevant topics. Studies conducted in recent years highlighted the antimicrobial potential of photodynamic therapy in endodontics. However, most of these studies were not able to confirm a significant improvement in root canal disinfection for photodynamic therapy as a substitute for current disinfection methods. Its indication as an excellent adjunct to conventional endodontic therapy is well documented, however. Data suggest the need for protocol adjustments or new photosensitizer formulations to enhance photodynamic therapy predictability in endodontics. PMID:25719896

  15. Antimicrobial Photodynamic Inactivation and Photodynamic Therapy for Infections

    PubMed Central

    Huang, Liyi; Dai, Tianhong; Hamblin, Michael R.

    2010-01-01

    Photodynamic therapy (PDT) was initially discovered over 100 years ago by its ability to kill microorganisms, but its use to treat infections clinically has not been much developed. However, the present relentless increase in antibiotic resistance worldwide and the emergence of strains that are resistant to all known antibiotics has stimulated research into novel antimicrobial strategies such as PDT that are thought to be unlikely to lead to the development of resistance. In this chapter we will cover the use of PDT to kill pathogenic microbial cells in vitro and describe a mouse model of localized infection and its treatment by PDT without causing excessive damage to the host tissue. PMID:20552347

  16. Temperature effects in photodynamic processes

    NASA Astrophysics Data System (ADS)

    Hovhannisyan, Vladimir A.; Avetisyan, Hasmik A.; Mathevosyan, Margarita B.; Elbakyan, Egishe G.

    2005-04-01

    Photodynamic activity of several dyes on Drosophila melanogaster at different temperatures (15-35°C) inside of test-tubes was investigated. Both phototoxic sensitizers (chlorin e6, methylene blue, etc. -group A) and non active compounds (hemoglobin, brilliant green, pyronine, etc.-group B) were used. Dyes of 10-5-10-3 M concentration were added to the food for drosophila 24 hours before irradiation. Solar radiation, narrow-band halogen lamps, LEDs and laser were used as a photo-stimulator. Irradiation parameters: I <= 45mW/cm2 and 0.2photodynamic effect. This, probably, is concerned with the toxic photoproduct suppression by the inactive dye. Experimental model of drosophila allows to investigate photosensitization impact within wide temperature range, to find out the processes, when using combination of dyes, as well as to study photodynamic effect on reproductive functions of insects.

  17. Photodynamic treatment for surface sanitation

    NASA Astrophysics Data System (ADS)

    Brovko, Lubov; Romanova, Nadya A.; Leslie, Christina; Ollivier, Helene; Griffiths, Mansel W.

    2005-09-01

    The bactericidal effect of visible light illumination on bacteria treated with non-toxic photosensitizers (PS) has been shown previously, its effectiveness depended on both cell type and nature of photosensitizer used. The photosensitizer (PS)-mediated bactericidal effect of light against different types of microorganisms including vegetative bacteria (both in planktonic form and in biofilms), bacterial spores, yeasts, viruses was investigated for both cells in liquid media, and on surface. Bactericidal effect was monitored for different photosensitizer such as TBO and derivatives of rosamine at different concentrations. The possibility of using photodynamic treatment for surface sanitation was investigated.

  18. Fluorescence photobleaching of ALA and ALA-heptyl ester induced protoporphyrin IX during photodynamic therapy of normal hairless mouse skin: a comparison of two light sources and different illumination schemes.

    PubMed

    Pudroma, Xiao; Juzeniene, Asta; Ma, Li-Wei; Iani, Vladimir; Moan, Johan

    2011-01-01

    This study investigated photobleaching of protoporphyrin IX (PpIX) induced by 5-aminolevulinic acid (ALA) and ALA-heptyl ester during superficial photodynamic therapy (PDT) in normal skin of the female BALB/c-nu/nu athymic mouse. We examined the effects of two light sources (laser and broadband lamp) and two different illumination schemes (fractionated light and continuous irradiation) on the kinetics of photobleaching. Our results show that light exposure (0-30 minutes, 10 mW/cm2) of wavelengths of approximately 420 nm (blue light) and 635 nm (red light) induced time-dependent PpIX photobleaching for mouse skin of 2% ALA and ALA-heptyl ester. Blue light (10 mW/cm2) caused more rapid PpIX photobleaching than did red light (100 mW/cm2), which is attributed to stronger absorption at 407 nm than at 632 nm for PpIX. In the case of light fractionation, fractionated light induced faster photobleaching compared with continuous light exposure after topical application of 2% ALA and ALA-heptyl ester in vivo. These have been suggested to allow reoxygenation of the irradiated tissue, with a consequent enhancement of singlet oxygen production in the second and subsequent fractions.

  19. Fluorescent standards for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Belko, N.; Kavalenka, S.; Samtsov, M.

    2016-08-01

    Photodynamic therapy is an evolving technique for treatment of various oncological diseases. This method employs photosensitizers - species that lead to death of tumor cells after the photoactivation. For further development and novel applications of photodynamic therapy new photosensitizers are required. After synthesis of a new photosensitizer it is important to know its concentration in different biological tissues after its administration and distribution. The concentration is frequently measured by the extraction method, which has some disadvantages, e.g. it requires many biological test subjects that are euthanized during the measurement. We propose to measure the photosensitizer concentration in tissue by its fluorescence. For this purpose fluorescent standards were developed. The standards are robust and simple to produce; their fluorescence signal does not change with time. The fluorescence intensity of fluorescent standards seems to depend linearly on the dye concentration. A set of standards thus allow the calibration of a spectrometer. Finally, the photosensitizer concentration can be determined by the fluorescence intensity after comparing the corresponding spectrum with spectra of the set of fluorescent standards. A biological test subject is not euthanized during this kind of experiment. We hope this more humane technique can be used in future instead of the extraction method.

  20. Vascular effect of photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Fyodorov, Svyatoslav N.; Kopayeva, V. G.; Andreev, J. B.; Ponomarev, Gelii V.; Stranadko, Eugeny P.; Suchin, H. M.

    1996-01-01

    Vascular effect of PDT has been studied in patients with corneal vascularized leucomas (10 patients) and in patients with corneal neovascularized transplant (3 patients). For vascularized leucomas the method of photodynamic therapy consisted of the local injection of dimegin (deiteroporphyrin derivative) into the space of the newly-formed vessels under operating microscope (opton) with the microneedle (diameter 200 microns) and corneal irradiation by the operating microscope light. For corneal neovascularized transplant the injection of photogem (hematoporphyrin derivative) intravenously were made with subsequent irradiation by light of dye laser (5 hours after the injection) with light density of 150 mW/cm2 for 15 minutes. In all the cases at the time of irradiation the aggregated blood flow was appeared, followed by blood flow stasis. In postoperative period the vessels disintegrated into separate fragments which disappeared completely after 10 - 15 days. Taking into account the data of light microscopy, the disappearance of the vessels took place as a result of the vascular endothelium lisis along the vascular walls. Neovascularized cornea and newly-formed vessels in tumor stroms have much in common. The vessel alterations study presented in this paper, may serve to specify the mechanism of photodynamic destruction of neovascularized stroma of tumor.

  1. Photodynamic therapy toward selective endometrial ablation

    NASA Astrophysics Data System (ADS)

    Tadir, Yona; Tromberg, Bruce J.; Krasieva, Tatiana B.; Berns, Michael W.

    1993-05-01

    Potential applications of photodynamic therapy for endometrial disease are discussed. Experimental models that may lead to diagnosis and treatment of endometriosis as well as selective endometrial ablation are summarized.

  2. Photodynamic Cancer Therapy - Recent Advances

    SciTech Connect

    Abrahamse, Heidi

    2011-09-22

    The basic principle of the photodynamic effect was discovered over a hundred years ago leading to the pioneering work on PDT in Europe. It was only during the 1980s, however, when 'photoradiation therapy' was investigated as a possible treatment modality for cancer. Photodynamic therapy (PDT) is a photochemotherapeutic process which requires the use of a photosensitizer (PS) that, upon entry into a cancer cell is targeted by laser irradiation to initiate a series of events that contribute to cell death. PSs are light-sensitive dyes activated by a light source at a specific wavelength and can be classified as first or second generation PSs based on its origin and synthetic pathway. The principle of PS activation lies in a photochemical reaction resulting from excitation of the PS producing singlet oxygen which in turn reacts and damages cell organelles and biomolecules required for cell function and ultimately leading to cell destruction. Several first and second generation PSs have been studied in several different cancer types in the quest to optimize treatment. PSs including haematoporphyrin derivative (HpD), aminolevulinic acid (ALA), chlorins, bacteriochlorins, phthalocyanines, naphthalocyanines, pheophorbiedes and purpurins all require selective uptake and retention by cancer cells prior to activation by a light source and subsequent cell death induction. Photodynamic diagnosis (PDD) is based on the fluorescence effect exhibited by PSs upon irradiation and is often used concurrently with PDT to detect and locate tumours. Both laser and light emitting diodes (LED) have been used for PDT depending on the location of the tumour. Internal cancers more often require the use of laser light delivery using fibre optics as delivery system while external PDT often make use of LEDs. Normal cells have a lower uptake of the PS in comparison to tumour cells, however the acute cytotoxic effect of the compound on the recovery rate of normal cells is not known. Subcellular

  3. Antimicrobial photodynamic therapy: An overview

    PubMed Central

    Rajesh, S.; Koshi, Elizabeth; Philip, Koshi; Mohan, Aparna

    2011-01-01

    Inflammatory periodontal disease caused by dental plaque is characterized by the clinical signs of inflammation and loss of periodontal tissue support. The mechanical removal of this biofilm and adjunctive use of antibacterial disinfectants and antibiotics have been the conventional methods of periodontal therapy. But the removal of plaque and the reduction in the number of infectious organisms can be impaired in sites with difficult access. The possibility of development of resistance to antibiotics by the target organism has led to the development of a new antimicrobial concept with fewer complications. Photodynamic therapy (PDT) involves the use of low power lasers with appropriate wavelength to kill micro organisms treated with a photosensitizer drug. PDT could be a useful adjunct to mechanical as well as antibiotics in eliminating periopathogenic bacteria. PMID:22368354

  4. A Prospective Study of Pain Control by a Two-Step Irradiance Schedule During Topical Photodynamic Therapy of Non-melanoma Skin Cancer

    PubMed Central

    Zeitouni, Nathalie C.; Sunar, Ulas; Rohrbach, Daniel J.; Paquette, Anne D.; Bellnier, David A.; Shi, Yi; Wilding, Gregory; Foster, Thomas H.; Henderson, Barbara W.

    2015-01-01

    Background Topical photodynamic therapy (PDT) for selected non-melanoma skin cancer, employing 5-aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) has yielded high long-term complete response rates with very good cosmesis. Pain during light activation of the photosensitizer can be a serious adverse event. A two-step irradiance protocol has previously been shown to minimize ALA-PDT pain. Objectives To determine the irradiance-dependent pain threshold for MAL-PDT, to adapt the two-step protocol to an LED light source, and assess clinical response. Methods In this prospective study, 25 superficial basal cell carcinoma (sBCC) received an initial irradiance by laser at 40 or 50 mW/cm2, or LED at 35 mW/cm2 followed by an irradiance at 70 mW/cm2 for a total of 75 J/cm2. Pain levels were recorded for both irradiance steps. Efficacy was assessed at 6, 12 or 24 months. Results Pain was mild in the 40/70 mW/cm2 laser cohort. Three instances of irradiance-limiting pain occurred at 50/70 mW/cm2. Pain was minimal in the 35/70 mW/cm2 LED cohort. Clinical response rates were 80% in the 50/70 mW/cm2 laser cohort and 90% in the 35/70 mW/cm2 LED cohort. Conclusions Topical PDT can be effectively delivered to sBCC with minimal treatment related pain by a two-step irradiance protocol. PMID:25393353

  5. Targeting PBR by hexaminolevulinate-mediated photodynamic therapy induces apoptosis through translocation of apoptosis-inducing factor in human leukemia cells.

    PubMed

    Furre, Ingegerd Eggen; Shahzidi, Susan; Luksiene, Zivile; Møller, Michael T N; Borgen, Elin; Morgan, Janet; Tkacz-Stachowska, Kinga; Nesland, Jahn M; Peng, Qian

    2005-12-01

    Photodynamic therapy (PDT) with endogenous protoporphyrin IX derived from 5-aminolevulinic acid or its derivatives has been established for treatments of several premalignancies and malignancies; however, the mechanism of the modality is not fully elucidated. The mitochondrial permeability transition pore consists mainly of the mitochondrial outer membrane voltage-dependent anion channel and the peripheral benzodiazepine receptor (PBR) and the mitochondrial inner membrane adenine nucleotide translocator (ANT). These mitochondrial proteins are responsible for the permeability transition that leads to apoptosis. In the present study, the human leukemia cell line, Reh, was treated with PDT using hexaminolevulinate (HAL). More than 80% of apoptotic Reh cells were found after HAL-mediated PDT (HAL-PDT) with high-molecular-weight (50 kbp) DNA fragmentation. Addition of PK11195 or Ro5-4864, two ligands of PBR, during HAL-PDT significantly inhibited the apoptotic effect. Bongkrekic acid, a ligand for ANT, also reduced the PDT effect. Although the mitochondrial transmembrane potential collapsed, neither cytosolic translocation of mitochondrial cytochrome c nor activation of caspase-9, caspase-8, caspase-3, and poly(ADP-ribose) polymerase were found. However, nuclear translocation of mitochondrial apoptosis-inducing factor (AIF) was shown by both immunoblotting and immunocytochemistry. Because AIF is the sole one among all proapoptotic factors involved in caspase-dependent and caspase-independent pathways that induces the high-molecular-weight DNA fragmentation, we conclude that HAL-PDT specifically targets PBR, leading to apoptosis of the Reh cells through nuclear translocation of mitochondrial AIF. This study suggests PBR as a possible novel therapeutic target for HAL-based PDT of cancer.

  6. Simvastatin may induce insulin resistance through a novel fatty acid mediated cholesterol independent mechanism

    PubMed Central

    Kain, Vasundhara; Kapadia, Bandish; Misra, Parimal; Saxena, Uday

    2015-01-01

    Statins are a class of oral drugs that are widely used for treatment of hypercholesterolemia. Recent clinical data suggest that chronic use of these drugs increases the frequency of new onset diabetes. Studies to define the risks of statin-induced diabetes and its underlying mechanisms are clearly necessary. We explored the possible mechanism of statin induced insulin resistance using a well-established cell based model and simvastatin as a prototype statin. Our data show that simvastatin induces insulin resistance in a cholesterol biosynthesis inhibition independent fashion but does so by a fatty acid mediated effect on insulin signaling pathway. These data may help design strategies for prevention of statin induced insulin resistance and diabetes in patients with hypercholesterolemia. PMID:26345110

  7. Poly(methacrylic acid)-mediated morphosynthesis of PbWO4 micro-crystals

    NASA Astrophysics Data System (ADS)

    Yu, J. G.; Zhao, X. F.; Liu, S. W.; Li, M.; Mann, S.; Ng, D. H. L.

    2007-04-01

    PbWO4 crystals with various morphologies were fabricated via a facile poly(methacrylic acid)-mediated hydrothermal route. Novel microsized PbWO4 single crystals with a needle-like shape as well as other morphologies, such as a fishbone, dendrite, sphere, spindle, ellipsoid, rod, and dumbbell with two dandelion-like heads, could be produced. The presence of PMAA, [Pb2+]/[WO4 2-] molar ratio (R), and aging temperature played key roles in the formation of the PbWO4 needle-like structures. Between temperatures of 60 to 150 °C, the length and photoluminescence intensities of the PbWO4 micro needles significantly increased with aging temperature, while the diameter did not change remarkably. Time-dependent experiments revealed that the formation of PbWO4 microneedles involved an unusual growth process, involving nucleation, oriented assembly and controlled mesoscale restructuring of nanoparticle building blocks.

  8. Lewis acid-mediated generation of bicyclo[5.3.0]decanes and bicyclo[4.3.0]nonanes.

    PubMed

    Deak, Holly L; Williams, Michael J; Snapper, Marc L

    2005-12-22

    [reactions: see text] Fragmentation of the cyclobutane-containing adducts generated from intramolecular cycloadditions of cyclobutadiene with olefins provides rapid entry into bicyclo[5.3.0]decane and bicyclo[4.3.0]nonane ring systems. Whereas earlier studies featured thermal methods to achieve the desired rearrangements, a mild, Lewis acid-mediated fragmentation has been identified for substrates with appropriate functionality adjacent to the strained ring system. The substrate scope and stereochemical outcome of the acid-mediated fragmentation are complementary to the thermal ring expansions, particularly in the case of the bicyclo[5.3.0]decanes.

  9. Selective tumor destruction with photodynamic therapy: exploitation of photodynamic thresholds

    NASA Astrophysics Data System (ADS)

    Barr, Hugh

    1991-11-01

    The uptake and distribution of the photosensitizer aluminum sulphonated phthalocyanine (AlSPc) has been studied. In a variety of experimentally induced gastrointestinal tumors the photosensitizer is retained between 24 - 48 hours after intravenous administration compared with the adjacent normal tissue in which the tumor arose. However, the maximum tumor-to- normal-tissue ratio was only 2:1. Quantitative fluorescence photometry using digital image processing, with a CCD camera and helium neon laser, was used to probe the microscopic localization of the photosensitizer in tissue sections of tumor and normal tissue. Selective localization of the photosensitizer was nonspecific in tumor stroma and there was never any significant difference between normal and neoplastic cells. Exploitation of the small differences in photosensitizer concentration, photodynamic threshold effects, and photosensitizer photodegration allows up to 2 mm of selective tumor damage to be produced in a tumor, when a similar light dose will produce no damage in adjacent normal tissue. However, selective eradication of a tumor without adjacent tissue damage will not be possible by using these methods. This paper reviews this previously reported data.

  10. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    PubMed Central

    Costa, Liliana; Faustino, Maria Amparo F.; Neves, Maria Graça P. M. S.; Cunha, Ângela; Almeida, Adelaide

    2012-01-01

    Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process. PMID:22852040

  11. Photodynamic inactivation of mammalian viruses and bacteriophages.

    PubMed

    Costa, Liliana; Faustino, Maria Amparo F; Neves, Maria Graça P M S; Cunha, Angela; Almeida, Adelaide

    2012-07-01

    Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

  12. Strategies for targeted antimicrobial photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Verma, Sarika; Sallum, Ulysses; Zheng, Xiang; Hasan, Tayyaba

    2009-06-01

    The photophysics and mechanisms of cell killing by photodynamic therapy (PDT) have been extensively studied in recent years, and PDT has received regulatory approval for the treatment of a number of diseases worldwide. As the application of this treatment modality expands with regard to both anatomical sites and diseases, it is important to develop strategies for enhancing PDT outcomes. Our group has focused on developing targeting strategies to enhance PDT for both cancerous as well as anti-microbial applications. In this article, we will discuss photosensitizer modification and conjugation strategies for targeted antimicrobial photodynamic therapy.

  13. Broadband radiometry for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Folgosi-Correa, M. S.; Caly, J. P.; Nogueira, G. E. C.

    2010-04-01

    The effective irradiance is a useful measure to compare performances of different broadband light sources and to more precisely predict the outcome of a topical photodynamic therapy. The effective irradiance (or effective fluence rate) and the exposition time of the optical radiation usually determine the light dose. The effective irradiance (Eeff) takes into account the spectral irradiance of the source as well as the action spectrum, where the wavelength dependence of both optical diffusion through tissue and photosensitizer are considered. In practice there are no standard action spectra for the currently used photosensitizers. As a consequence, measured values of effective irradiance using different action spectra can not be compared. In order to solve this problem, the basis of the calibration theory developed for the broadband ultraviolet radiometry can be applied, where an experimental radiometer is compared with a standard radiometer. Here is presented a simple set of linear relations in the form Eeff = k . E, where E is the source irradiance and k a real positive value, here denoted as a characteristic of the radiometer, as valuable tools for correction of effective irradiances measured according to different action spectra. As a result, for two effective radiometers with different characteristics k1 and k2, measured values are Eeff and Qeff respectively, and it is easily shown that the value Eeff = Qeff • k1/k2 .

  14. Photodynamic therapy of gastric cancer

    NASA Astrophysics Data System (ADS)

    Kharnas, Sergey S.; Kuzin, N. M.; Zavodnov, Victor Y.; Sclyanskaya, Olga A.; Linkov, Kirill G.; Loschenov, Victor B.; Meerovich, Gennadii A.; Torshina, Nadezgda L.; Stratonnikov, Alexander A.; Steiner, Rudolf W.

    1996-01-01

    Photodynamic therapy (PDT) with the use of laser endoscopic spectrum analyzer (LESA-5), the spectral-analyzing video-imaging system, Kr laser and various types of catheters for different tumor localizations, and Phthalocyanine aluminum photosensitizers in patients with gastric cancer was discussed. PDT was carried out in fifteen patients with gastric cancer. There were the following indications for PDT: early gastric cancer (3 patients), malignant stenosis of the cardia or pyloric portion of the stomach (4 patients), cancer of gastric stump with stenosis of gastrojejunal anastomosis (1 patient), preoperative treatment of patients with large but probably resectable gastric tumor size (7 patients). Usually we used 3 - 4 seances of laser treatment 10 - 30 minutes long. Concentration of photosensitizer in normal and malignant tissue was controlled by LESA-5. Treatment was monitored by spectral-analyzing video- imaging system in fluorescent light. The results show high efficiency of PDT especially in patients with early gastric cancer (necrosis of all tumor mass, i.e. complete regression of tumor). For all other patients we obtained partial regression of gastric cancer.

  15. Functionalized Fullerenes in Photodynamic Therapy

    PubMed Central

    Huang, Ying-Ying; Sharma, Sulbha K.; Yin, Rui; Agrawal, Tanupriya; Chiang, Long Y.; Hamblin, Michael R.

    2014-01-01

    Since the discovery of C60 fullerene in 1985, scientists have been searching for biomedical applications of this most fascinating of molecules. The unique photophysical and photochemical properties of C60 suggested that the molecule would function well as a photosensitizer in photodynamic therapy (PDT). PDT uses the combination of non-toxic dyes and harmless visible light to produce reactive oxygen species that kill unwanted cells. However the extreme insolubility and hydrophobicity of pristine C60, mandated that the cage be functionalized with chemical groups that provided water solubility and biological targeting ability. It has been found that cationic quaternary ammonium groups provide both these features, and this review covers work on the use of cationic fullerenes to mediate destruction of cancer cells and pathogenic microorganisms in vitro and describes the treatment of tumors and microbial infections in mouse models. The design, synthesis, and use of simple pyrrolidinium salts, more complex decacationic chains, and light-harvesting antennae that can be attached to C60, C70 and C84 cages are covered. In the case of bacterial wound infections mice can be saved from certain death by fullerene-mediated PDT. PMID:25544837

  16. Can nanotechnology potentiate photodynamic therapy?

    PubMed Central

    Huang, Ying-Ying; Sharma, Sulbha K.; Dai, Tianhong; Chung, Hoon; Yaroslavsky, Anastasia; Garcia-Diaz, Maria; Chang, Julie; Chiang, Long Y.

    2015-01-01

    Photodynamic therapy (PDT) uses the combination of non-toxic dyes and harmless visible light to produce reactive oxygen species that can kill cancer cells and infectious microorganisms. Due to the tendency of most photosensitizers (PS) to be poorly soluble and to form nonphotoactive aggregates, drug-delivery vehicles have become of high importance. The nanotechnology revolution has provided many examples of nanoscale drug-delivery platforms that have been applied to PDT. These include liposomes, lipoplexes, nanoemulsions, micelles, polymer nanoparticles (degradable and nondegradable), and silica nanoparticles. In some cases (fullerenes and quantum dots), the actual nanoparticle itself is the PS. Targeting ligands such as antibodies and peptides can be used to increase specificity. Gold and silver nanoparticles can provide plasmonic enhancement of PDT. Two-photon excitation or optical upconversion can be used instead of one-photon excitation to increase tissue penetration at longer wavelengths. Finally, after sections on in vivo studies and nanotoxicology, we attempt to answer the title question, “can nano-technology potentiate PDT?” PMID:26361572

  17. Photodynamic Therapy in Pediatric Dentistry

    PubMed Central

    da Silva Barbosa, Patricia; Duarte, Danilo Antônio; Leite, Mariana Ferreira; de Sant' Anna, Giselle Rodrigues

    2014-01-01

    Conservation of deciduous teeth with pulp alterations caused by caries and trauma is a major therapeutic challenge in pediatric dentistry as a result of the internal anatomy and life cycle characteristic. It is essential that the root canal procedures sanitizers have a performance in eliminating bacterial. In this context, antimicrobial photodynamic therapy (PAT) is promising and emerging as adjuvant therapy in an attempt to eliminate the microorganisms persistent to chemi-mechanical preparation. Since there is presence of oxygen in cells, photosensitizer activated by light can react with molecules in its vicinity by electrons' or hydrogen's transfer, leading to microorganism death. This paper reports the case of 4-year-old patient, female, with early childhood caries. The proposed endodontic treatment incuded chemomechanical treatment allied to PAT in the decontamination of root canals using methylene blue dye 50 μg/mL during 3–5 minutes and 40 J/cm2 as energy density, taking into account the need for tissue penetration and effectiveness of PAT inside the dentinal tubules. PMID:25371829

  18. Defluoridation of water using dicarboxylic acids mediated chitosan-polyaniline/zirconium biopolymeric complex.

    PubMed

    Muthu Prabhu, Subbaiah; Meenakshi, Sankaran

    2016-04-01

    The present investigation describes the preparation of hydrogen bonded chitosan-polyaniline/zirconium biopolymeric matrix by grafting method under dicarboxylic acid medium for the removal of fluoride, first time. Herein, the dicarboxylic acids, oxalic acid, malonic acid, succinic acid were used as medium. The synthesized complex was characterized by usual analytical techniques like FTIR, XRD, SEM and EDAX analysis. From the batch equilibrium experiments, the maximum defluoridation capacity (DC) was found to be 8.713 mg/g at room temperature with the minimum contact time of 24 min at 100mg of the sorbent dosage. The temperature study results of adsorption kinetics showed the adsorption behavior could be better described by the pseudo-second-order equation than pseudo-first-order kinetic model. The adsorption isotherm was well fitted by the Freundlich equation rather than Langmuir and D-R isotherms. The mechanism of fluoride removal was ligand exchange at neutral pH and electrostatic attraction at acidic pH of the medium. Regeneration studies were carried out to identify the best regenerant which makes the process cost-effective. Conclusions of this work demonstrate the potential applicability of the dicarboxylic acid mediated chitosan-polyaniline/zirconium complex as an effective adsorbent for fluoride removal from water. PMID:26706844

  19. Defluoridation of water using dicarboxylic acids mediated chitosan-polyaniline/zirconium biopolymeric complex.

    PubMed

    Muthu Prabhu, Subbaiah; Meenakshi, Sankaran

    2016-04-01

    The present investigation describes the preparation of hydrogen bonded chitosan-polyaniline/zirconium biopolymeric matrix by grafting method under dicarboxylic acid medium for the removal of fluoride, first time. Herein, the dicarboxylic acids, oxalic acid, malonic acid, succinic acid were used as medium. The synthesized complex was characterized by usual analytical techniques like FTIR, XRD, SEM and EDAX analysis. From the batch equilibrium experiments, the maximum defluoridation capacity (DC) was found to be 8.713 mg/g at room temperature with the minimum contact time of 24 min at 100mg of the sorbent dosage. The temperature study results of adsorption kinetics showed the adsorption behavior could be better described by the pseudo-second-order equation than pseudo-first-order kinetic model. The adsorption isotherm was well fitted by the Freundlich equation rather than Langmuir and D-R isotherms. The mechanism of fluoride removal was ligand exchange at neutral pH and electrostatic attraction at acidic pH of the medium. Regeneration studies were carried out to identify the best regenerant which makes the process cost-effective. Conclusions of this work demonstrate the potential applicability of the dicarboxylic acid mediated chitosan-polyaniline/zirconium complex as an effective adsorbent for fluoride removal from water.

  20. Photodynamics of nonlinear fullerene-containing media

    NASA Astrophysics Data System (ADS)

    Belousova, Inna M.; Belousov, Vlidilen P.; Danilov, Oleg B.; Grigor'ev, Vladimir A.; Kalintsev, Alexander G.; Zgonnik, V. N.; Kamanina, Natalia V.; Zhevlakov, Aleksandr P.; Kris'ko, A. V.; Mironova, N. G.; Sosnov, Eugene N.; Gavronskaya, E. A.; Smirnov, V. A.; Yur'ev, Michail S.; Ponomarev, Alexander N.; Yashin, Vladimir E.

    2001-03-01

    The results of theoretical and experimental studies on photodynamics and mechanism of nonlinear optical processes, responsible for optical limiting of power radiation in the wavelength range from 0.3 to 1.3 microns, are presented. Peculiarities in the mechanisms of optical limiting for different fullerene-containing matrices, including solutions, solid-state and polymer systems, are shown.

  1. In vitro effects of Panax ginseng in aristolochic acid-mediated renal tubulotoxicity: apoptosis versus regeneration.

    PubMed

    Bunel, Valérian; Antoine, Marie-Hélène; Nortier, Joëlle; Duez, Pierre; Stévigny, Caroline

    2015-03-01

    This in vitro study aimed to determine the effects of a Panax ginseng extract on aristolochic acid-mediated toxicity in HK-2 cells. A methanolic extract of ginseng (50 µg/mL) was able to reduce cell survival after treatment with 50 µM aristolochic acid for 24, 48, and 72 h, as evidenced by a resazurin reduction assay. This result was confirmed by a flow cytometric evaluation of apoptosis using annexin V-PI staining, and indicated higher apoptosis rates in cells treated with aristolochic acid and P. ginseng extract compared with aristolochic acid alone. However, P. ginseng extract by itself (5 and 50 µg/mL) increased the Ki-67 index, indicating an enhancement in cellular proliferation. Cell cycle analysis excluded a P. ginseng extract-mediated induction of G2/M cell cycle arrest such as the one typically observed with aristolochic acid. Finally, β-catenin acquisition was found to be accelerated when cells were treated with both doses of ginseng, suggesting that the epithelial phenotype of renal proximal tubular epithelial cells was maintained. Also, ginseng treatment (5 and 50 µg/mL) reduced the oxidative stress activity induced by aristolochic acid after 24 and 48 h. These results indicate that the ginseng extract has a protective activity towards the generation of cytotoxic reactive oxygen species induced by aristolochic acid. However, the ginseng-mediated alleviation of oxidative stress did not correlate with a decrease but rather with an increase in aristolochic acid-induced apoptosis and death. This deleterious herb-herb interaction could worsen aristolochic acid tubulotoxicity and reinforce the severity and duration of the injury. Nevertheless, increased cellular proliferation and migration, along with the improvement in the epithelial phenotype maintenance, indicate that ginseng could be useful for improving tubular regeneration and the recovery following drug-induced kidney injury. Such dual activities of ginseng certainly warrant further in vivo

  2. Photodynamic therapy of cervical intraepithelial neoplasia

    NASA Astrophysics Data System (ADS)

    Inada, Natalia M.; Lombardi, Welington; Leite, Marieli F. M.; Trujillo, Jose R.; Kurachi, Cristina; Bagnato, Vanderlei S.

    2014-03-01

    Photodynamic therapy (PDT) is a technique that has been used for the treatment of tumors, especially in Gynecology. The photodynamic reaction is based on the production of reactive oxygen species after the activation of a photosensitizer. Advantages of the PDT in comparison to the surgical resection are: ambulatory treatment and tissue recovery highly satisfactory, through a non-invasive procedure. The cervical intraepithelial neoplasia (CIN) grades I and II presents potential indications for PDT. The aim of the proposed study is to evaluate the safety and efficacy of the PDT for the diagnostics and treatment of CIN I and II. The equipment and the photosensitizer are produced in Brazil with a representative low cost. It is possible to visualize the fluorescence of the cervix and to treat the lesions, without side effects. The proposed clinical protocol shows great potential to become a public health technique.

  3. Second generation photodynamic agents: a review.

    PubMed

    Sternberg, E D; Dolphin, D

    1993-10-01

    Over the last decade, laser treatment of neoplastic diseases has become routine. The ability of these light-induced therapies to effect positive results is increased with the utilization of photosensitizing dyes. The approval of Photofrin in Canada as a first generation photodynamic therapeutic agent for the treatment of some forms of bladder cancer is being followed by the development of other agents with improved properties. At this time a number of second generation photosensitizing dyes are under study in phase I/II clinical trials. A review of the status of these trials along with mechanistic aspects is reviewed in this article. In addition, a review of the status of lasers to be utilized for photodynamic therapy gives some indication of which instruments could be considered for this therapy in the future.

  4. Second generation photodynamic agents: a review.

    PubMed

    Sternberg, E D; Dolphin, D

    1993-10-01

    Over the last decade, laser treatment of neoplastic diseases has become routine. The ability of these light-induced therapies to effect positive results is increased with the utilization of photosensitizing dyes. The approval of Photofrin in Canada as a first generation photodynamic therapeutic agent for the treatment of some forms of bladder cancer is being followed by the development of other agents with improved properties. At this time a number of second generation photosensitizing dyes are under study in phase I/II clinical trials. A review of the status of these trials along with mechanistic aspects is reviewed in this article. In addition, a review of the status of lasers to be utilized for photodynamic therapy gives some indication of which instruments could be considered for this therapy in the future. PMID:10146514

  5. Resistance in antimicrobial photodynamic inactivation of bacteria.

    PubMed

    Maisch, Tim

    2015-08-01

    Antibiotics have increasingly lost their impact to kill bacteria efficiently during the last 10 years. The emergence and dissemination of superbugs with resistance to multiple antibiotic classes have occurred among Gram-positive and Gram-negative strains including Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter strains. These six superbugs can "escape" more or less any single kind of antibiotic treatment. That means bacteria are very good at developing resistance against antibiotics in a short time. One new approach is called photodynamic antimicrobial chemotherapy (PACT) which already has demonstrated an efficient antimicrobial efficacy among multi-resistant bacteria. Until now it has been questionable if bacteria can develop resistance against PACT. This perspective summarises the current knowledge about the susceptibility of bacteria towards oxidative stress and sheds some light on possible strategies of the development of photodynamic inactivation of bacteria (PACT)-induced oxidative stress resistance by bacteria.

  6. Present status of photodynamic procedures in urology

    NASA Astrophysics Data System (ADS)

    Jocham, Dieter; Thomas, Stephen

    1994-03-01

    Since 1976, photodynamic therapy (PDT) has been used for the treatment of different stages of urothelial bladder tumors. First applications were based on the irradiation of single exophytic tumors using bare fibers for laser irradiation (630 mm) or bright white light generated e.g. from a mercury arc lamp. Clinical results of several centers demonstrated the possibility of destroying single superficially growing tumors. A new approach to the treatment of multifocal growing tumors, including the endoscopically often undetectable carcinoma in situ, was provided by the development of treatment modalities allowing for whole bladder wall irradiation. Photodynamic diagnosis (PDD) is a novel procedure for detecting flat precancerous and malignant lesions undetectable by endoscopy alone on the basis of laser- induced fluorescence.

  7. [Photodynamic therapy: non-oncologic indications].

    PubMed

    Karrer, S; Szeimies, R-M

    2007-07-01

    While efficacy of topical photodynamic therapy (PDT) for the treatment of superficial non-melanoma skin cancer is already well-proven by several controlled clinical trials, there are only a few controlled studies showing efficacy of PDT for non-oncologic skin disorders. This report provides information on the use of PDT for inflammatory skin disorders, disorders of the pilosebaceous unit, infections of the skin, sclerotic skin diseases and cosmetic indications. PMID:17546432

  8. Photodynamic therapy for pododermatitis in penguins.

    PubMed

    Sellera, Fábio Parra; Sabino, Caetano Padial; Ribeiro, Martha Simões; Fernandes, Loriê Tukamoto; Pogliani, Fabio Celidonio; Teixeira, Carlos Roberto; Dutra, Gustavo Henrique Pereira; Nascimento, Cristiane Lassálvia

    2014-01-01

    Pododermatitis is currently one of most frequent and important clinical complications in seabirds kept in captivity or in rehabilitation centers. In this study, five Magellanic penguins with previous pododermatitis lesions on their footpad were treated with photodynamic therapy (PDT). All PDT treated lesions successfully regressed and no recurrence was observed during the 6-month follow-up period. PDT seems to be an inexpensive and effective alternative treatment for pododermatitis in Magellanic penguins encouraging further research on this topic.

  9. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    SciTech Connect

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  10. Retinoblastoma: might photodynamic therapy be an option?

    PubMed

    Teixo, Ricardo; Laranjo, Mafalda; Abrantes, Ana Margarida; Brites, Gonçalo; Serra, Arménio; Proença, Rui; Botelho, Maria Filomena

    2015-12-01

    Retinoblastoma is a tumor that mainly affects children under 5 years, all over the world. The origin of these tumors is related with mutations in the RB1 gene, which may result from genetic alterations in cells of the germ line or in retinal somatic cells. In developing countries, the number of retinoblastoma-related deaths is higher due to less access to treatment, unlike what happens in developed countries where survival rates are higher. However, treatments such as chemotherapy and radiotherapy, although quite effective in treating this type of cancer, do not avoid high indices of mortality due to secondary malignances which are quite frequent in these patients. Additionally, treatments such as cryotherapy, thermotherapy, thermochemotherapy, or brachytherapy represent other options for retinoblastoma. When all these approaches fail, enucleation is the last option. Photodynamic therapy might be considered as an alternative, particularly because of its non-mutagenic character. Photodynamic therapy is a treatment modality based on the administration of photosensitizing molecules that only upon irradiation of the tumor with a light source of appropriate wavelength are activated, triggering its antitumor action. This activity may be not only due to direct damage to tumor cells but also due to damage caused to the blood vessels responsible for the vascular supply of the tumor. Over the past decades, several in vitro and in vivo studies were conducted to assess the effectiveness of photodynamic therapy in the treatment of retinoblastoma, and very promising results were achieved.

  11. Combined surgery and photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Douplik, Alexandre

    According to the recent guidelines, the gold standard is resecting an extra 0.5-3 cm beyond the lesion margins that are visually detected and/or biopsy confirmed depending on type of malignancy and its localisation to avoid missing the residuals of the tumour. Often, such a large resection leads to dysfunctions of the organ or tissues, which underwent the surgery. In some cases, an extra tumour-free margin cannot be achieved because of tumour proximity to vital sites such as major vascular or nerve structures. Photodynamic Therapy (PDT) is an emerging clinical modality to locally destroy cancer lesions selectively. The limitation of photodynamic therapy is the curable depth of an order of one centimetre or less. A combination of cancer surgery following by PDT can bring a benefit to reduce the resection and minimise the impact on the organ or tissue functionality. Combination of cancer surgery and photodynamic therapy provides another opportunity-fluorescence image guidance of cancer removal. Most of the photosensitizers intensively fluoresce and hence facilitate a strong fluorescence contrast versus healthy adjacent tissues.

  12. Anacardic acid-mediated changes in membrane potential and pH gradient across liposomal membranes.

    PubMed

    Toyomizu, Masaaki; Okamoto, Katsuyuki; Akiba, Yukio; Nakatsu, Tetsuo; Konishi, Tetsuya

    2002-01-01

    We have previously shown that anacardic acid has an uncoupling effect on oxidative phosphorylation in rat liver mitochondria using succinate as a substrate (Life Sci. 66 (2000) 229-234). In the present study, for clarification of the physicochemical characteristics of anacardic acid, we used a cyanine dye (DiS-C3(5)) and 9-aminoacridine (9-AA) to determine changes of membrane potential (DeltaPsi) and pH difference (DeltapH), respectively, in a liposome suspension in response to the addition of anacardic acid to the suspension. The anacardic acid quenched DiS-C3(5) fluorescence at concentrations higher than 300 nM, with the degree of quenching being dependent on the log concentration of the acid. Furthermore, the K(+) diffusion potential generated by the addition of valinomycin to the suspension decreased for each increase in anacardic acid concentration used over 300 nM, but the sum of the anacardic acid- and valinomycin-mediated quenching was additively increasing. This indicates that the anacardic acid-mediated quenching was not due simply to increments in the K(+) permeability of the membrane. Addition of anacardic acid in the micromolar range to the liposomes with DeltaPsi formed by valinomycin-K(+) did not significantly alter 9-AA fluorescence, but unexpectedly dissipated DeltaPsi. The DeltaPsi preformed by valinomycin-K(+) decreased gradually following the addition of increasing concentrations of anacardic acid. The DeltaPsi dissipation rate was dependent on the pre-existing magnitude of DeltaPsi, and was correlated with the logarithmic concentration of anacardic acid. Furthermore, the initial rate of DeltapH dissipation increased with logarithmic increases in anacardic acid concentration. These results provide the evidence for a unique function of anacardic acid, dissimilar to carbonylcyanide p-trifluoromethoxyphenylhydrazone or valinomycin, in that anacardic acid behaves as both an electrogenic (negative) charge carrier driven by DeltaPsi, and a 'proton

  13. Graphene-based nanovehicles for photodynamic medical therapy.

    PubMed

    Li, Yan; Dong, Haiqing; Li, Yongyong; Shi, Donglu

    2015-01-01

    Graphene and its derivatives such as graphene oxide (GO) have been widely explored as promising drug delivery vehicles for improved cancer treatment. In this review, we focus on their applications in photodynamic therapy. The large specific surface area of GO facilitates efficient loading of the photosensitizers and biological molecules via various surface functional groups. By incorporation of targeting ligands or activatable agents responsive to specific biological stimulations, smart nanovehicles are established, enabling tumor-triggering release or tumor-selective accumulation of photosensitizer for effective therapy with minimum side effects. Graphene-based nanosystems have been shown to improve the stability, bioavailability, and photodynamic efficiency of organic photosensitizer molecules. They have also been shown to behave as electron sinks for enhanced visible-light photodynamic activities. Owing to its intrinsic near infrared absorption properties, GO can be designed to combine both photodynamic and photothermal hyperthermia for optimum therapeutic efficiency. Critical issues and future aspects of photodynamic therapy research are addressed in this review.

  14. Photoangioplasty: new applications of photodynamic therapy in atherosclerosis

    NASA Astrophysics Data System (ADS)

    Rockson, Stanley G.

    2000-05-01

    Atherosclerosis has traditionally held appeal as a pathologic entity in which photodynamic therapy might arrest or reverse the manifestations of disease. Earlier attempts to bring photodynamic therapy to the human clinical arena were hampered by the limitations of the photosensitizers under investigation, including the propensity to phototoxic manifestations and light-induced trauma to surrounding, normal vascular tissues. Many of these inherent limitations may be circumvented by newer photosensitizers that are activated at longer, more optimal wavelengths of light energy. Advances in fiberoptic catheter design for the endovascular delivery of light have also contributed to the greater applicability of photodynamic therapy to human atherosclerosis. Initial experiences with one family of photosensitizers, the texaphyrins, indicate that photodynamic therapy of human peripheral arterial atherosclerosis is feasible, safe, and well-tolerated. Photodynamic therapy of atherosclerosis holds promise for the treatment of de novo atherosclerosis and may have future applicability in the treatment, and perhaps prevention, of restenosis.

  15. Photodynamic therapy for treatment subretinal neovascularization

    NASA Astrophysics Data System (ADS)

    Avetisov, Sergey E.; Budzinskaja, Maria V.; Kiseleva, Tatyana N.; Balatskaya, Natalia V.; Gurova, Irina V.; Loschenov, Viktor B.; Shevchik, Sergey A.; Kuzmin, Sergey G.; Vorozhtsov, Georgy N.

    2007-07-01

    This work are devoted our experience with photodynamic therapy (PDT) with <> for patients with choroidal neovascularization (CNV). 18 patients with subfoveal CNV in age-related macular degeneration (AMD), 24 patients with subfoveal CNV in pathological myopia (PM) and 4 patients with subfoveal CNV associated with toxoplasmic retinochoroiditis were observed. CNV was 100% classic in all study patients. Standardized protocol refraction, visual acuity testing, ophthalmologic examinations, biomicroscopy, fluorescein angiography, and ultrasonography were performed before treatment and 1 month, 3 months, 6 months, and 1 year after treatment; were used to evaluate the results of photodynamic therapy with <> (0.02% solution of mixture sulfonated aluminium phtalocyanine 0.05 mg/kg, intravenously). A diode laser (<>, Inc, Moscow) was used operating in the range of 675 nm. Need for retreatment was based on fluorescein angiographic evidence of leakage at 3-month follow-up intervals. At 3, 6, 9 month 26 (56.5%) patients had significant improvement in the mean visual acuity. At the end of the 12-month minimal fluorescein leakage from choroidal neovascularization was seen in 12 (26.1%) patients and the mean visual acuity was slightly worse than 0.2 which was not statistically significant as compared with the baseline visual acuity. Patients with fluorescein leakage from CNV underwent repeated PDT with <>. 3D-mode ultrasound shown the decreasing thickness of chorioretinal complex in CNV area. Photodynamic therapy with <> can safely reduce the risk of severe vision loss in patients with predominantly classic subfoveal choroidal neovascularization secondary to AMD, PM and toxoplasmic retinochoroiditis.

  16. In-office Painless Aminolevulinic Acid Photodynamic Therapy

    PubMed Central

    2016-01-01

    Objective: To evaluate the efficacy, safety, and pain of in-office “painless” aminolevulinic acid photodynamic therapy aimed at decreasing treatment-associated pain in patients undergoing removal of actinic keratoses. Design: Prospective split-face study comparing short aminolevulinic acid incubation times of 15 minutes followed by extended exposure (60 minutes) of continuous blue light versus conventional aminolevulinic acid photodynamic therapy. Prospective assessment of pain in patients undergoing in-office “painless” aminolevulinic acid photodynamic therapy. Setting: Clinical practice office. Participants: Three patients with actinic keratoses participated in the split-face study and 101 in the pain assessment study. Measurements: Evaluations in the split-face study included removal of actinic keratoses, skin temperature, and pain measured on a 10-point visual analog scale. Pain was assessed using the visual analog scale in the pain assessment study. Results: In the split-face study, in-office “painless” aminolevulinic acid photodynamic therapy resulted in a 52-percent reduction in lesions versus 44 percent for conventional aminolevulinic acid photodynamic therapy. Maximum pain scores of in-office “painless” aminolevulinic acid photodynamic therapy were all 0 at each time point, and the average score for conventional aminolevulinic acid photodynamic therapy was 7. Baseline skin temperatures increased from a baseline of 29 to 32°C to 34 to 35°C by minute 10 of blue light activation on both sides of the face. Results from the pain assessment study indicated no or minimal (scores 0-2) pain in nearly all patients who received in-office “painless” aminolevulinic acid photodynamic therapy as monotherapy or in combination with 5-fluoruacil or imiquimod used as pretreatments. Conclusions: In-office “painless” aminolevulinic acid photodynamic therapy appears to be effective for removing actinic keratoses and is associated with little or no pain

  17. Flexible textile light diffuser for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Selm, Barbel; Camenzind, Martin

    2005-03-01

    In this article a new medical application is introduced using textile production techniques to deliver a defined radiation dose. The advantage for photodynamic therapy (PDT) is that a flat luminous textile structure can homogeneously illuminate unequal body surfaces. The optical properties of this two-dimensional luminous pad are characterized with a set of bench-scale tests. In vitro investigations on petri dishes with cultivated cells and first clinical tests on animal patients are promising. In addition first measurement results are presented together with an outlook to future developments.

  18. Photodynamic dosimetry in the treatment of periodontitis

    NASA Astrophysics Data System (ADS)

    Andersen, Roger C.; Loebel, Nicolas G.; Andersen, Dane M.

    2009-06-01

    Photodynamic therapy has been demonstrated to effectively kill human periopathogens in vitro. However, the translation of in vitro work to in vivo clinical efficacy has been difficult due to the number of variables present in any given patient. Parameters such as photosensitizer concentration, duration of light therapy and amount of light delivered to the target tissue all play a role in the dose response of PDT in vivo. In this 121 patient study we kept all parameters the same except for light dose which was delivered at either 150 mW or 220 mW. This clearly demonstrated the clinical benefits of a higher light dose in the treatment of periodontitis.

  19. Endoscopic photodynamic therapy (PDT) for oesophageal cancer.

    PubMed

    Moghissi, Keyvan

    2006-06-01

    Endoscopic photodynamic therapy (PDT) is undertaken only when tumour is visible endoscopically with malignancy biopsy confirmed. Patients will be either Group A: inoperable cases with locally advanced cancer when the aim is palliation of dysphagia, or Group E: patients with early stage I-II disease who are unsuitable for surgery or decline operation, when the intent is curative. Following assessment for suitability for PDT and counselling, Photofrin 2mg/(kgbw) is administered 24-72h before endoscopic illumination using a Diode 630nm laser. Illumination may be either interstitial or intraluminal at a dose of 100-200J/cm. PMID:25049097

  20. Acceleration Of Wound Healing Ny Photodynamic Therapy

    DOEpatents

    Hasan, Tayyaba; Hamblin, Michael R.; Trauner, Kenneth

    2000-08-22

    Disclosed is a method for accelerating wound healing in a mammal. The method includes identifying an unhealed wound site or partially-healed wound site in a mammal; administering a photosensitizer to the mammal; waiting for a time period wherein the photosensitizer reaches an effective tissue concentration at the wound site; and photoactivating the photosensitizer at the wound site. The dose of photodynamic therapy is selected to stimulate the production of one or more growth factor by cells at the wound site, without causing tissue destruction.

  1. Hormonal component of tumor photodynamic therapy response

    NASA Astrophysics Data System (ADS)

    Korbelik, Mladen; Merchant, Soroush

    2008-02-01

    The involvement of adrenal glucocorticoid hormones in the response of the treatment of solid tumors by photodynamic therapy (PDT) comes from the induction of acute phase response by this modality. This adrenal gland activity is orchestrated through the engagement of the hypothalamic-pituitary-adrenal hormonal axis incited by stress signals emanating from the PDT-treated tumor. Glucocorticoid hormone activity engendered within the context of PDT-induced acute phase response performs multiple important functions; among other involvements they beget acute phase reactant production, systemic neutrophil mobilization, and control the production of inflammation-modulating and immunoregulatory proteins.

  2. Clinical use of photodynamic therapy in ocular tumors.

    PubMed

    Cerman, Eren; Çekiç, Osman

    2015-01-01

    Although the introduction of intravitreal anti-vascular endothelial growth factor drugs reduced the indications for photodynamic therapy in ophthalmology, it may still be used in various ocular tumors. Although many studies have shown that photodynamic therapy is effective in ocular tumors, the literature consists of case reports and series. In this review, we systematically performed a meta-analysis for the use of photodynamic therapy in circumscribed choroidal hemangioma, diffuse choroidal hemangioma, retinal capillary hemangioma, von Hippel-Lindau angiomatosis, choroidal melanoma, retinal astrocytoma, retinoblastoma, eyelid tumors, conjunctival tumors, and choroidal metastasis.

  3. Photosensitizer and light diffusion through dentin in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Nogueira, Ana C.; Graciano, Ariane X.; Nagata, Juliana Y.; Fujimaki, Mitsue; Terada, Raquel S. S.; Bento, Antonio C.; Astrath, Nelson G. C.; Baesso, Mauro L.

    2013-05-01

    Photodynamic therapy has been considered a potential antimicrobial modality against oral infections, including dental caries. A model to estimate the penetration of both photosensitizers and light through human dentin, a factor of interest in photodynamic therapy, is proposed. The photoacoustic spectroscopy technique was used to evaluate in vitro dentin permeability of three different photosensitizers. Using the dentin optical absorption and scattering coefficients, it was possible to propose a semi-quantitative model predicting both photosensitizer and light doses within dentin. The graphic illustrations obtained provided guidelines that may be useful in photodynamic therapy protocols used as antimicrobial tools in caries lesions.

  4. Nicotinamide augments the survival and incidence of apoptosis in glioma cells following photodynamic therapy in vitro

    NASA Astrophysics Data System (ADS)

    Bisland, Stuart K.; Modi, Nayan; Wilson, Brian C.

    2004-10-01

    The ability to customize photodynamic therapy (PDT) parameters with regards to timing and dosing of administered drug and light can be beneficial in determining target specificity and mode of cell death. Sustained, low level PDT or metronomic PDT (mPDT) may afford enhanced apoptotic cell death. This is of particular importance when considering PDT for the treatment of brain tumors as unlike apoptosis, necrotic cell death often leads to inflammation with increased intracranial pressure. The ability, therefore, to 'fine tune' PDT in favour of apoptosis is paramount. We have studied both acute (one time treatment) PDT (aPDT) and mPDT delivery strategies in combination with nicotinamide (NA) in an attempt to maximize the number of tumor cells dieing by apoptosis. Using several different glioma cell lines (9L, U87-MG and CNS-1) we now confirm that NA provides a dose-dependent (0.1-0.5 mM) increase in apoptotic cells following d-aminolevulinic acid-mediated aPDT or mPDT. Furthermore, using the 9L cell line stably transfected with the luciferase gene, NA was shown to delay the depletion of bioluminscence signal in aPDT and mPDT treated cells, inferring that adenosine triphosphate levels are maintained for longer following NA treatment. NA has previously been reported as promoting neuronal and vascular cell survival in normal brain following a number of neurological insults in which reactive oxygen species are implicated including, stroke, Alzheimer's disease and toxin-induced lesions. It is likely that the effects of NA reflect its capacity as an antioxidant as well as its ability to inhibit poly (adenosine diphosphate-ribose) polymerase-mediated depletion of ATP. Our results indicate that NA may prove therapeutically advantageous when used in combination with PDT treatment of brain tumors.

  5. Role of multidrug resistance in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Diddens, Heyke C.

    1992-06-01

    Multidrug resistance in cancer chemotherapy is a well established phenomenon. One of the most common phenotypical changes in acquired or intrinsic multidrug resistance in human tumor cells is the overexpression of the mdrl gene product P-glycoprotein, which acts as an active efflux pump. Increased levels of P-glycoprotein are associated with resistance to a variety of anticancer drugs commonly used in tumor chemotherapy like anthracyclins, vinca- alcaloids, epipodophyllotoxins or actinomycin D. We investigated the efficacy or photodynamic therapy in the treatment of tumor cells expressing the multidrug resistance phenotype. Our data show that multidrug resistant cells are highly cross resistant to the phototoxic stain rhodamine 123 but exhibit only low degrees of cross resistance (2 - 3 -folds) to the photosensitizers Photosan-3, Clorin-2, methylene blue and meso-tetra (4- sulfonatophenyl) porphine (TPPS4). Resistance is associated with a decrease in intracellular accumulation of the photosensitizer. Verapamil, a membrane active compound known to enhance drug sensitivity in multidrug resistant cells by inhibition of P-glycoprotein, also increases phototoxicity in multidrug resistant cells. Our results imply that tumors expressing the multidrug resistance phenotype might fail to respond to photochemotherapy with rhodamine 123. On the other hand, multidrug resistance may not play an important role in photodynamic therapy with Photosan-3, Chlorin-2, methylene blue or TPPS4.

  6. Fighting fish parasites with photodynamically active chlorophyllin.

    PubMed

    Häder, D-P; Schmidl, J; Hilbig, R; Oberle, M; Wedekind, H; Richter, P

    2016-06-01

    Water-soluble chlorophyll (chlorophyllin) was used in a phototoxic reaction against a number of fish ectoparasites such as Ichtyobodo, Dactylogyrus, Trichodina, and Argulus. Chlorophyllin is applied to the water at concentrations of several micrograms per milliliter for a predefined incubation time, and afterwards, the parasites are exposed to simulated solar radiation. Application in the dark caused only little damage to the parasites; likewise, light exposure without the addition of the photosensitizer was ineffective. In Ichthyobodo, 2 μg/mL proved sufficient with subsequent simulated solar radiation to almost quantitatively kill the parasites, while in Dactylogyrus, a concentration of about 6 μg/mL was necessary. The LD50 value for this parasite was 1.02 μg/mL. Trichodina could be almost completely eliminated at 2 μg/mL. Only in the parasitic crustacean Argulus, no killing could be achieved by a photodynamic reaction using chlorophyllin. Chlorophyllin is non-toxic, biodegradable, and can be produced at low cost. Therefore, we propose that chlorophyllin (or other photodynamic substances) are a possible effective countermeasure against several ectoparasites in ponds and aquaculture since chemical remedies are either forbidden and/or ineffective.

  7. Photodynamic-induced inactivation of Propionibacterium acnes

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten; Teschke, M.; Eick, Stephen G.; Pfister, W.; Meyer, Herbert; Halbhuber, Karl-Juergen

    1998-05-01

    We report on photodynamically induced inactivation of the skin bacterium Propionibacterium acnes (P. acnes) using endogenous as well as exogenous photosensitizers and red light sources. P. acnes is involved in the pathogenesis of the skin disease acne vulgaris. The skin bacterium is able to synthesize the metal-free fluorescent porphyrins protoporphyrin IX (PP) and coproporphyrin (CP) as shown by in situ spectrally-resolved detection of natural autofluorescence of human skin and bacteria colonies. These naturally occurring intracellular porphyrins act as efficient endogenous photosensitizers. Inactivation of P. acnes suspensions was achieved by irradiation with He-Ne laser light in the red spectral region (632.8 nm). We monitored the photodynamically-induced death of single bacteria using a fluorescent viability kit in combination with confocal laser scanning microscopy. In addition, the photo-induced inactivation was calculated by CFU (colony forming units) determination. We found 633 nm-induced inactivation (60 mW, 0.12 cm2 exposure area, 1 hour irradiation) of 72% in the case of non-incubated bacteria based on the destructive effect of singlet oxygen produced by red light excited endogenous porphyrins and subsequent energy transfer to molecular oxygen. In order to achieve a nearly complete inactivation within one exposure procedure, the exogenous photosensitizer Methylene Blue (Mb) was added. Far red exposure of Mb-labeled bacteria using a krypton ion laser at 647 nm and 676 nm resulted in 99% inactivation.

  8. Drug Carrier for Photodynamic Cancer Therapy

    PubMed Central

    Debele, Tilahun Ayane; Peng, Sydney; Tsai, Hsieh-Chih

    2015-01-01

    Photodynamic therapy (PDT) is a non-invasive combinatorial therapeutic modality using light, photosensitizer (PS), and oxygen used for the treatment of cancer and other diseases. When PSs in cells are exposed to specific wavelengths of light, they are transformed from the singlet ground state (S0) to an excited singlet state (S1–Sn), followed by intersystem crossing to an excited triplet state (T1). The energy transferred from T1 to biological substrates and molecular oxygen, via type I and II reactions, generates reactive oxygen species, (1O2, H2O2, O2*, HO*), which causes cellular damage that leads to tumor cell death through necrosis or apoptosis. The solubility, selectivity, and targeting of photosensitizers are important factors that must be considered in PDT. Nano-formulating PSs with organic and inorganic nanoparticles poses as potential strategy to satisfy the requirements of an ideal PDT system. In this review, we summarize several organic and inorganic PS carriers that have been studied to enhance the efficacy of photodynamic therapy against cancer. PMID:26389879

  9. Treatment of ichthyophthiriasis with photodynamically active chlorophyllin.

    PubMed

    Häder, D-P; Schmidl, J; Hilbig, R; Oberle, M; Wedekind, H; Richter, P R

    2016-04-01

    Water-soluble chlorophyll (chlorophyllin) exerts pronounced photodynamic activity on fish parasites. In order to determine its potential as a remedy against ectoparasites in fish carps were incubated in water with defined concentrations of chlorophyllin. The main focus of the experiments was on the ciliate Ichthyophthirius multifiliis (Fouquet) which is responsible for considerable losses in livestock in aquaculture. As malachite green, which in the past efficiently cured infected fishes, is banned because of its possible carcinogenicity; no effective remedy is presently available in aquaculture to treat ichthyophthiriasis. Using chlorophyllin, the number of trophonts was significantly reduced (more than 50 %) after 3 h incubation of infested fish at 2 and 4 mg/L and subsequent irradiation with simulated solar radiation. The lack of reinfection after light treatment indicates that also the remaining parasites have lost their multiplication capacity. In the controls (no chlorophyllin and no light, light but no chlorophyllin, or chlorophyllin but no light), no reduction of the I. multifiliis infection was observed. We propose that chlorophyllin (or other photodynamic substances) is a possible effective countermeasure against I. multifiliis and other ectoparasites in aquaculture. PMID:26693716

  10. Photodynamic Therapy in Non-Gastrointestinal Thoracic Malignancies.

    PubMed

    Kidane, Biniam; Hirpara, Dhruvin; Yasufuku, Kazuhiro

    2016-01-21

    Photodynamic therapy has a role in the management of early and late thoracic malignancies. It can be used to facilitate minimally-invasive treatment of early endobronchial tumours and also to palliate obstructive and bleeding effects of advanced endobronchial tumours. Photodynamic therapy has been used as a means of downsizing tumours to allow for resection, as well as reducing the extent of resection necessary. It has also been used successfully for minimally-invasive management of local recurrences, which is especially valuable for patients who are not eligible for radiation therapy. Photodynamic therapy has also shown promising results in mesothelioma and pleural-based metastatic disease. As new generation photosensitizers are being developed and tested and methodological issues continue to be addressed, the role of photodynamic therapy in thoracic malignancies continues to evolve.

  11. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    NASA Astrophysics Data System (ADS)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  12. Photodynamic action of protoporphyrin IX derivatives on Trichophyton rubrum*

    PubMed Central

    Ramos, Rogério Rodrigo; Kozusny-Andreani, Dora Inês; Fernandes, Adjaci Uchôa; Baptista, Mauricio da Silva

    2016-01-01

    BACKGROUND Dermatophytes are filamentous keratinophilic fungi. Trichophyton rubrum is a prevalent infectious agent in tineas and other skin diseases. Drug therapy is considered to be limited in the treatment of such infections, mainly due to low accessibility of the drug to the tissue attacked and development of antifungal resistance in these microorganisms. In this context, Photodynamic Therapy is presented as an alternative. OBJECTIVE Evaluate, in vitro, the photodynamic activity of four derivatives of Protoporphyrin IX by irradiation with LED 400 nm in T. rubrum. METHOD Assays were subjected to irradiation by twelve cycles of ten minutes at five minute intervals. RESULT Photodynamic action appeared as effective with total elimination of UFCs from the second irradiation cycle. CONCLUSION Studies show that the photodynamic activity on Trichophyton rubrum relates to a suitable embodiment of the photosensitizer, which can be maximized by functionalization of peripheral groups of the porphyrinic ring. PMID:27192510

  13. Photodynamic Therapy in Non-Gastrointestinal Thoracic Malignancies

    PubMed Central

    Kidane, Biniam; Hirpara, Dhruvin; Yasufuku, Kazuhiro

    2016-01-01

    Photodynamic therapy has a role in the management of early and late thoracic malignancies. It can be used to facilitate minimally-invasive treatment of early endobronchial tumours and also to palliate obstructive and bleeding effects of advanced endobronchial tumours. Photodynamic therapy has been used as a means of downsizing tumours to allow for resection, as well as reducing the extent of resection necessary. It has also been used successfully for minimally-invasive management of local recurrences, which is especially valuable for patients who are not eligible for radiation therapy. Photodynamic therapy has also shown promising results in mesothelioma and pleural-based metastatic disease. As new generation photosensitizers are being developed and tested and methodological issues continue to be addressed, the role of photodynamic therapy in thoracic malignancies continues to evolve. PMID:26805818

  14. Inhibiton of photodynamic haemolysis by Gratiola officinalis L. extract

    NASA Astrophysics Data System (ADS)

    Tkachenko, Natalie; Pravdin, Alexander; Terentyuk, George; Navolokin, Nikita; Kurchatova, Maria; Polukonova, Natalia

    2015-03-01

    On the model of photodynamic haemolysis, the membranoprotective properties of a plant origin antioxidant, Gratiola officinalis L. extract, have been studied based on its ability to inhibit photodamage of sensitized erythrocyte membranes. The effect of different concentrations of the antioxidant on the photodynamic hemolysis has been studied; and the influence of incubation time on the membranoprotective properties of Gratiola officinalis L. extract has also been revealed.

  15. Photodynamic activity of thiophene-derived lysosome-specific dyes.

    PubMed

    Baldassarre, Francesca; Foglietta, Federica; Vergaro, Viviana; Barbero, Nadia; Capodilupo, Agostina L; Serpe, Loredana; Visentin, Sonja; Tepore, Antonio; Ciccarella, Giuseppe

    2016-05-01

    The photodynamic activity occurring through the lysosome photo-damage is effective in terms of triggered synergic effects which can avoid chemo-resistance pathways. The potential photodynamic activity of two fluorescent lysosome-specific probes was studied providing their interaction with human serum albumin, demonstrating their in vitro generation of singlet oxygen and investigating the resulted photo-toxic effect in human cancer cells. PMID:26930158

  16. [Photodynamic reaction and oxidative stress - influence of the photodynamic effect on the activity antioxidant enzymes].

    PubMed

    Romiszewska, Anna; Nowak-Stępniowska, Agata

    2014-01-01

    The interaction of light with a photosensitizer, accumulated in a tissue in the presence of oxygen, leads to formation of reactive oxygen species, mainly of singlet oxygen and free radicals. These factors react with biomolecules producing their oxidized states. Reactive oxygen species, such as singlet oxygen and free radicals are able to damage membranes, DNA, enzymes, structural peptides and other cellular structures leading to cell death. An antioxidant protection of cell is formed by enzymes belonging to the family of oxidoreductases: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR). Photodynamic therapy leads to the increased production of oxidizing toxic forms. It is important to analyze impact of PDT on the activity of antioxidant enzymes, such as SOD, CAT, GPx. The activity of antioxidant enzymes during the photodynamic effect is influenced by both the light energy dose and the concentration of photosensitizer. The presence only of the photosensitizer or only the light energy may also result in changes in the activity of these enzymes. The differences in changes in the activity of these enzymes depend on the type of used photosensitizer. A phenomenon of selective accumulation of photosensitizer in tumor tissues is used in the photodynamic method of tumor diagnosis and treatment.

  17. Photodynamic therapy and its role in periodontitis treatment.

    PubMed

    Mielczarek-Badora, Ewa; Szulc, Małgorzata

    2013-11-13

    Photodynamic therapy is a novel therapeutic approach for eradicating pathogenic bacteria in periodontal disease. Inactivation of microorganisms using photodynamic therapy has been defined as either antimicrobial photodynamic therapy (aPDT), photodynamic antimicrobial chemotherapy (PACT) or photodynamic disinfection. The use of aPDT requires a non-toxic photosensitizer, harmless visible light and oxygen. The photosensitizer binds to targeted bacteria and then can be activated by light of the appropriate wavelength in the presence of oxygen. Photoinactivation of bacteria is tightly restricted to the localization of the photosensitizer, ensuring the protection of distant cells from side-effects. Because of the fact that conventional treatment such as scaling and root planing (SRP) does not completely eliminate periodontal pathogens, especially in deep periodontal pockets, aPDT may be considered to be an alternative therapeutic strategy. This article describes the mechanism of aPDT and novel approaches such as nanoparticles. The aim of the study was to review the literature concerning the assessment of the effectiveness of aPDT in periodontitis treatment. Although studies have not indicated the superiority of aPDT compared to conventional periodontitis treatment, antimicrobial photodynamic treatment has been reported to be effective as an adjunct to conventional therapy to destroy bacteria in sites where there is limited access for mechanical instrumentation.

  18. Oxidative stress of photodynamic antimicrobial chemotherapy inhibits Candida albicans virulence

    NASA Astrophysics Data System (ADS)

    Kato, Ilka Tiemy; Prates, Renato Araujo; Tegos, George P.; Hamblin, Michael R.; Simões Ribeiro, Martha

    2011-03-01

    Photodynamic antimicrobial chemotherapy (PACT) is based on the principal that microorganisms will be inactivated using a light source combined to a photosensitizing agent in the presence of oxygen. Oxidative damage of cell components occurs by the action of reactive oxygen species leading to cell death for microbial species. It has been demonstrated that PACT is highly efficient in vitro against a wide range of pathogens, however, there is limited information for its in vivo potential. In addition, it has been demonstrated that sublethal photodynamic inactivation may alter the virulence determinants of microorganisms. In this study, we explored the effect of sublethal photodynamic inactivation to the virulence factors of Candida albicans. Methylene Blue (MB) was used as photosensitizer for sublethal photodynamic challenge on C. albicans associated with a diode laser irradiation (λ=660nm). The parameters of irradiation were selected in causing no reduction of viable cells. The potential effects of PACT on virulence determinants of C. albicans cells were investigated by analysis of germ tube formation and in vivo pathogenicity assays. Systemic infection was induced in mice by the injection of fungal suspension in the lateral caudal vein. C. albicans exposed to sublethal photodynamic inactivation formed significantly less germ tube than untreated cells. In addition, mice infected with C. albicans submitted to sublethal PACT survived for a longer period of time than mice infected with untreated cells. The oxidative damage promoted by sublethal photodynamic inactivation inhibited virulence determinants and reduced in vivo pathogenicity of C. albicans.

  19. Nonlinear stability of a heterogeneous state in a PDE-ODE model for acid-mediated tumor invasion.

    PubMed

    Tao, Youshan; Tello, J Ignacio

    2016-02-01

    This work studies a general reaction-diffusion model for acid-mediated tumor invasion, where tumor cells produce excess acid that primarily kills healthy cells, and thereby invade the microenvironment. The acid diffuses and could be cleared by vasculature, and the healthy and tumor cells are viewed as two species following logistic growth with mutual competition. A key feature of this model is the density-limited diffusion for tumor cells, reflecting that a healthy tissue will spatially constrain a tumor unless shrunk. Under appropriate assumptions on model parameters and on initial data, it is shown that the unique heterogeneous state is nonlinearly stable, which implies a long-term coexistence of the healthy and tumor cells in certain parameter space. Our theoretical result suggests that acidity may play a significant role in heterogeneous tumor progression. PMID:26776259

  20. Nonlinear stability of a heterogeneous state in a PDE-ODE model for acid-mediated tumor invasion.

    PubMed

    Tao, Youshan; Tello, J Ignacio

    2016-02-01

    This work studies a general reaction-diffusion model for acid-mediated tumor invasion, where tumor cells produce excess acid that primarily kills healthy cells, and thereby invade the microenvironment. The acid diffuses and could be cleared by vasculature, and the healthy and tumor cells are viewed as two species following logistic growth with mutual competition. A key feature of this model is the density-limited diffusion for tumor cells, reflecting that a healthy tissue will spatially constrain a tumor unless shrunk. Under appropriate assumptions on model parameters and on initial data, it is shown that the unique heterogeneous state is nonlinearly stable, which implies a long-term coexistence of the healthy and tumor cells in certain parameter space. Our theoretical result suggests that acidity may play a significant role in heterogeneous tumor progression.

  1. Photodynamic Cancer Therapy—Recent Advances

    NASA Astrophysics Data System (ADS)

    Abrahamse, Heidi

    2011-09-01

    The basic principle of the photodynamic effect was discovered over a hundred years ago leading to the pioneering work on PDT in Europe. It was only during the 1980s, however, when "photoradiation therapy" was investigated as a possible treatment modality for cancer. Photodynamic therapy (PDT) is a photochemotherapeutic process which requires the use of a photosensitizer (PS) that, upon entry into a cancer cell is targeted by laser irradiation to initiate a series of events that contribute to cell death. PSs are light-sensitive dyes activated by a light source at a specific wavelength and can be classified as first or second generation PSs based on its origin and synthetic pathway. The principle of PS activation lies in a photochemical reaction resulting from excitation of the PS producing singlet oxygen which in turn reacts and damages cell organelles and biomolecules required for cell function and ultimately leading to cell destruction. Several first and second generation PSs have been studied in several different cancer types in the quest to optimize treatment. PSs including haematoporphyrin derivative (HpD), aminolevulinic acid (ALA), chlorins, bacteriochlorins, phthalocyanines, naphthalocyanines, pheophorbiedes and purpurins all require selective uptake and retention by cancer cells prior to activation by a light source and subsequent cell death induction. Photodynamic diagnosis (PDD) is based on the fluorescence effect exhibited by PSs upon irradiation and is often used concurrently with PDT to detect and locate tumours. Both laser and light emitting diodes (LED) have been used for PDT depending on the location of the tumour. Internal cancers more often require the use of laser light delivery using fibre optics as delivery system while external PDT often make use of LEDs. Normal cells have a lower uptake of the PS in comparison to tumour cells, however the acute cytotoxic effect of the compound on the recovery rate of normal cells is not known. Subcellular

  2. A Comprehensive Tutorial on In Vitro Characterization of New Photosensitizers for Photodynamic Antitumor Therapy and Photodynamic Inactivation of Microorganisms

    PubMed Central

    Maisch, Tim; Berneburg, Mark; Plaetzer, Kristjan

    2013-01-01

    In vitro research performed on eukaryotic or prokaryotic cell cultures usually represents the initial step for characterization of a novel photosensitizer (PS) intended for application in photodynamic therapy (PDT) of cancer or photodynamic inactivation (PDI) of microorganisms. Although many experimental steps of PS testing make use of the wide spectrum of methods readily employed in cell biology, special aspects of working with photoactive substances, such as the autofluorescence of the PS molecule or the requirement of light protection, need to be considered when performing in vitro experiments in PDT/PDI. This tutorial represents a comprehensive collection of operative instructions, by which, based on photochemical and photophysical properties of a PS, its uptake into cells, the intracellular localization and photodynamic action in both tumor cells and microorganisms novel photoactive molecules may be characterized for their suitability for PDT/PDI. Furthermore, it shall stimulate the efforts to expand the convincing benefits of photodynamic therapy and photodynamic inactivation within both established and new fields of applications and motivate scientists of all disciplines to get involved in photodynamic research. PMID:23762860

  3. Intraoperative photodynamic therapy for larynx carcinomas

    NASA Astrophysics Data System (ADS)

    Loukatch, Erwin V.; Latyshevska, Galina; Fekeshgazi, Ishtvan V.

    1995-05-01

    We made an experimental and clinical researches to examine Intraoperative Photodynamic Therapy (IPT) as a method to prevent the recidives of tumors. In experimental researches on models with radio-inducated fibrosarcomas and Erlich carcinomas of mice the best method of IPT was worked out. The therapeutic effect was studied also on patients with laryngeal cancer. In researches on C3H mice the antirecidive effect of IPT established with local administration of methylene blue and Ar-laser. We found that IPT (He-Ne laser combined with methylene blue administration) was endured by patients with laryngeal cancers without problems. We got good results of treatment 42 patients with laryngeal cancers with middle localization during three years with using IPT method. This can show the perspectives of using this method in treatment of other ENT-oncological diseases.

  4. PHOTODYNAMIC THERAPY OF CANCER: AN UPDATE

    PubMed Central

    Agostinis, Patrizia; Berg, Kristian; Cengel, Keith A.; Foster, Thomas H.; Girotti, Albert W.; Gollnick, Sandra O.; Hahn, Stephen M.; Hamblin, Michael R.; Juzeniene, Asta; Kessel, David; Korbelik, Mladen; Moan, Johan; Mroz, Pawel; Nowis, Dominika; Piette, Jacques; Wilson, Brian C.; Golab, Jakub

    2011-01-01

    Photodynamic therapy (PDT) is a clinically approved, minimally invasive therapeutic procedure that can exert a selective cytotoxic activity toward malignant cells. The procedure involves administration of a photosensitizing agent followed by irradiation at a wavelength corresponding to an absorbance band of the sensitizer. In the presence of oxygen, a series of events lead to direct tumor cell death, damage to the microvasculature and induction of a local inflammatory reaction. Clinical studies revealed that PDT can be curative particularly in early-stage tumors. It can prolong survival in inoperable cancers and significantly improve quality of life. Minimal normal tissue toxicity, negligible systemic effects, greatly reduced long-term morbidity, lack of intrinsic or acquired resistance mechanisms, and excellent cosmetic as well as organ function-sparing effects of this treatment make it a valuable therapeutic option for combination treatments. With a number of recent technological improvements, PDT has the potential to become integrated into the mainstream of cancer treatment. PMID:21617154

  5. Monitoring photodynamic therapy with photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Shao, Peng; Chapman, David W.; Moore, Ronald B.; Zemp, Roger J.

    2015-10-01

    We present our work on examining the feasibility of monitoring photodynamic therapy (PDT)-induced vasculature change with acoustic-resolution photoacoustic microscopy (PAM). Verteporfin, an FDA-approved photosensitizer for clinical PDT, was utilized. With a 60-μm-resolution PAM system, we demonstrated the capability of PAM to monitor PDT-induced vasculature variations in a chick chorioallantoic membrane model with topical application and in a rat ear with intravenous injection of the photosensitizer. We also showed oxygen saturation change in target blood vessels due to PDT. Success of the present approach may potentially lead to the application of PAM imaging in evaluating PDT efficacy, guiding treatment, and predicting responders from nonresponders.

  6. Photodynamic therapy of different photosensitizers in leukemia

    NASA Astrophysics Data System (ADS)

    Zhang, Sujuan; Zhang, Zhenxi; Jiang, Dazong

    2002-04-01

    Photodynamic therapy (PDT), a cancer treatment using a photosensitizer and visible light has been applied to treatment of blood cancer-leukemia. The effect of PDT may be modulated by the leukemia cell type; the photosensitizer's type, dose, dose rate changes; the incubation time; the light wavelength, dosage, dose rate change; the conjugation of photosensitizers to variety subcellular target: cell membrane, mitochondia, lipoprotein or liposome; the addition of chemotherapeutic agents et al. Many reports in the current literature are confusing and often apparently contradictory. In this article, we have attempted to conduct and present a comprehensive review of this rapidly expanding novel field in a range of photosensitizers. Cell types, photosensitizers, treatment conditions and mechanism of PDT are considered. Nonetheless, there is ample ground for optimism, and such knowledge as we already have should effectively underpin the clinical research that is ongoing.

  7. Photodynamic therapy as an antifungal treatment

    PubMed Central

    LIANG, YI; LU, LI-MING; CHEN, YONG; LIN, YOU-KUN

    2016-01-01

    Photodynamic therapy (PDT) involves the systemic or topical application of a photosensitizer (PS), alongside the selective illumination of the target lesion with light of an appropriate wavelength, in order to promote localized oxidative photodamage and subsequent cell death. Numerous studies have demonstrated that PDT is highly effective in the destruction of fungi in vitro. The mechanism underlying the effects of PDT results from the photons of visible light of an appropriate wavelength interacting with the intracellular molecules of the PS. Reactive species are produced as a result of the oxidative stress caused by the interaction between the visible light and the biological tissue. At present, no antifungal treatment based on PDT has been licensed. However, antifungal PDT is emerging as an area of interest for research. PMID:27347012

  8. Light emitting fabric technologies for photodynamic therapy.

    PubMed

    Mordon, Serge; Cochrane, Cédric; Tylcz, Jean Baptiste; Betrouni, Nacim; Mortier, Laurent; Koncar, Vladan

    2015-03-01

    Photodynamic therapy (PDT) is considered to be a promising method for treating various types of cancer. A homogeneous and reproducible illumination during clinical PDT plays a determinant role in preventing under- or over-treatment. The development of flexible light sources would considerably improve the homogeneity of light delivery. The integration of optical fiber into flexible structures could offer an interesting alternative. This paper aims to describe different methods proposed to develop Side Emitting Optical Fibers (SEOF), and how these SEOF can be integrated in a flexible structure to improve light illumination of the skin during PDT. Four main techniques can be described: (i) light blanket integrating side-glowing optical fibers, (ii) light emitting panel composed of SEOF obtained by micro-perforations of the cladding, (iii) embroidery-based light emitting fabric, and (iv) woven-based light emitting fabric. Woven-based light emitting fabrics give the best performances: higher fluence rate, best homogeneity of light delivery, good flexibility.

  9. Scope of photodynamic therapy in periodontics.

    PubMed

    Kumar, Vivek; Sinha, Jolly; Verma, Neelu; Nayan, Kamal; Saimbi, C S; Tripathi, Amitandra K

    2015-01-01

    Periodontal disease results from inflammation of the supporting structure of the teeth and in response to chronic infection caused by various periodontopathic bacteria. The mechanical removal of this biofilm and adjunctive use of antibacterial disinfectants and antibiotics have been the conventional methods of periodontal therapy. However, the removal of plaque and the reduction in the number of infectious organisms can be impaired in sites with difficult access. Photodynamic therapy (PDT) is a powerful laser-initiated photochemical reaction, involving the use of a photoactive dye (photosensitizer) activated by light of a specific wavelength in the presence of oxygen. Application of PDT in periodontics such as pocket debridement, gingivitis, and aggressive periodontitis continue to evolve into a mature clinical treatment modality and is considered as a promising novel approach for eradicating pathogenic bacteria in periodontitis. PMID:26481895

  10. Photodynamic therapy for port wine stains

    NASA Astrophysics Data System (ADS)

    Li, Junheng

    1998-11-01

    Previous therapies for port wine stains usually cause unacceptable scarring or obtain poor effect. Because port wine is a congenital vasculopathy consisting of an abnormal network of capillaries in the upper dermis with an overlying normal epidermis and the researchers found the tumor blood vessels were occluded accompanying the necrosis of the tumor after PDT. The author and his colleagues started a series of animal and clinical studies since 1991 about photodynamic therapy for port wine stain an they established the method of PDT for PWS. The clinical studies of over 1500 cases proved that PWS can be cured by PDT without scar formation because there is no thermal effect involved. No relapse was found within a maximum follow-up of six years.

  11. Colonic mucosectomy using laser photodynamic therapy

    SciTech Connect

    Fisher, D.G.; Rypins, E.B.; Watson, L.R.; Nelson, J.S.; Berns, M.W.

    1989-06-01

    Photodynamic therapy (PDT) involves photosensitizing tissue and then activating it with monochromatic light, causing necrosis. Precise control of the extent of injury should be possible by varying the energy density of the light applied to the target tissue. We tested the sensitivity of colonic tissue to PDT by injecting 10 mg/kg Photofrin II intraperitoneally in 10 rats. After 24 hr the left colon was opened and cleansed. A 1.0-cm2 area of mucosa was exposed to 630 nm (red) light produced by an argon-pumped dye laser. Pairs of rats were treated with energy densities of either 10, 20, 40, 60, or 80 J/cm2, controlled by varying exposure times. After 48 hr, we sacrificed the rats and fixed, sectioned, and stained the left colons. The depth of injury was measured with an ocular micrometer and expressed as a percentage of normal bowel wall thickness. A curve was fit to the data points by computerized nonlinear regression. The relationship between depth of injury (Y) and energy density (X) was found to fit the equation Y = 1 - aebx, where constants a = 1.15 and b = -0.0353, (R2 = 0.93, P less than 0.001). The relationship between injury and energy density is biphasic, rising rapidly from 0 to 40 J/cm2 and more slowly after this point, suggesting that colonic mucosa is more sensitive to PDT than muscularis, providing a margin of safety against perforation. Bowel perforation did not occur in this study but is predicted by extrapolation for energy densities of 100 J/cm2 or greater. These data indicate that photodynamic colonic mucosectomy is possible.

  12. A folic acid conjugated silica-titania porous hollow nanosphere for improved topical photodynamic therapy.

    PubMed

    Jang, Yoonsun; Kim, Sojin; Oh, Wan-Kyu; Kim, Chanhoi; Lee, Inkyu; Jang, Jyongsik

    2014-12-18

    The folic acid conjugated hollow nanosphere is used to encapsulate protoporphyrin IX and is utilized for photodynamic therapy. This system represents a 3.33 times higher photodynamic efficiency than previous protoporphyrin IX-based systems. The result proposes a new opportunity for effective photodynamic therapy of folate receptor positive tumor cells.

  13. Sono-photodynamic combination therapy: a review on sensitizers.

    PubMed

    Sadanala, Krishna Chaitanya; Chaturvedi, Pankaj Kumar; Seo, You Mi; Kim, Jeung Mo; Jo, Yong Sam; Lee, Yang Koo; Ahn, Woong Shick

    2014-09-01

    Cancer is characterized by the dysregulation of cell signaling pathways at several steps. The majority of current anticancer therapies involve the modulation of a single target. A tumor-targeting drug-delivery system consists of a tumor detection moiety and a cytotoxic material joined directly or through a suitable linker to form a conjugate. Photodynamic therapy has been used for more than 100 years to treat tumors. One of the present goals of photodynamic therapy research is to enhance the selective targeting of tumor cells in order to reduce the risk and extension of unwanted side-effects, caused by normal cell damage. Sonodynamic therapy is a promising new treatment for patients with cancer. It treats cancer with ultrasound and sonosensitive agents. Porphyrin compounds often serve as photosensitive and sonosensitive agents. The combination of these two methods makes cancer treatment more effective. The present review provides an overview of photodynamic therapy, sonodynamic therapy, sono-photodynamic therapy and the four sensitizers which are suitable candidates for combined sono-photodynamic therapy.

  14. Photodynamic therapy for multi-resistant cutaneous Langerhans cell histiocytosis

    PubMed Central

    Failla, Valérie; Wauters, Odile; Caucanas, Marie; Nikkels-Tassoudji, Nazli; Nikkels, Arjen F

    2010-01-01

    Langerhans cell histiocytosis is a rare group of proliferative disorders. Beside cutaneous involvement, other internal organs can be affected. The treatment of cutaneous lesions is difficult and relies on topical corticosteroids, carmustine, nitrogen mustard, and photochemotherapy. Systemic steroids and vinblastine are used for recalcitrant skin lesions. However, some cases fail to respond. An 18-month old boy presented a CD1a+, S100a+ Langerhans cell histocytosis with cutaneous and severe scalp involvement. Topical corticosteroids and nitrogen mustard failed to improve the skin lesions. Systemic corticosteroids and vinblastine improved the truncal involvement but had no effect on the scalp lesions. Methylaminolevulinate (MAL) based photodynamic therapy (PDT) resulted in a significant regression of the scalp lesions. Control histology revealed an almost complete clearance of the tumor infiltrate. Clinical follow-up after six months showed no recurrence. Although spontaneous regression of cutaneous Langerhans cell histiocytosis is observed, the rapid effect of photodynamic therapy after several failures of other treatment suggests that photodynamic therapy was successful. As far as we know this is the first report of photodynamic therapy for refractory skin lesions. Larger series are needed to determine whether photodynamic therapy deserves a place in the treatment of multiresistant cutaneous Langerhans cell histiocytosis. PMID:21139836

  15. Graphene-based nanovehicles for photodynamic medical therapy

    PubMed Central

    Li, Yan; Dong, Haiqing; Li, Yongyong; Shi, Donglu

    2015-01-01

    Graphene and its derivatives such as graphene oxide (GO) have been widely explored as promising drug delivery vehicles for improved cancer treatment. In this review, we focus on their applications in photodynamic therapy. The large specific surface area of GO facilitates efficient loading of the photosensitizers and biological molecules via various surface functional groups. By incorporation of targeting ligands or activatable agents responsive to specific biological stimulations, smart nanovehicles are established, enabling tumor-triggering release or tumor-selective accumulation of photosensitizer for effective therapy with minimum side effects. Graphene-based nanosystems have been shown to improve the stability, bioavailability, and photodynamic efficiency of organic photosensitizer molecules. They have also been shown to behave as electron sinks for enhanced visible-light photodynamic activities. Owing to its intrinsic near infrared absorption properties, GO can be designed to combine both photodynamic and photothermal hyperthermia for optimum therapeutic efficiency. Critical issues and future aspects of photodynamic therapy research are addressed in this review. PMID:25848263

  16. Photodynamic therapy: Biophysical mechanisms and molecular responses

    NASA Astrophysics Data System (ADS)

    Mitra, Soumya

    In photodynamic therapy (PDT), photochemical reactions induced by optical activation of sensitizer molecules cause destruction of the target tissue. In this thesis we present results of several related studies, which investigated the influence of photophysical properties and photobleaching mechanisms of sensitizers and oxygen-dependent tissue optical properties on PDT treatment efficacy. The bleaching mechanism of the sensitizer meso-tetra hydroxyphenyl chlorin (mTHPC) is examined indirectly using measurements of photochemical oxygen consumption during PDT irradiation of multicell tumor spheroids. Analysis of the results with a theoretical model of oxygen diffusion that incorporates the effects of sensitizer photobleaching shows that mTHPC is degraded via a singlet-oxygen (1O2)-mediated bleaching process. The analysis allows us to extract photophysical parameters of mTHPC which are used to account for its enhanced clinical photodynamic potency in comparison to that of Photofrin. Evaluation of the spatially-resolved fluorescence in confocal optical sections of intact spheroids during PDT irradiation allows for the direct experimental verification of mTHPC's 1O2-mediated bleaching mechanism. The technique is also used to investigate the complex bleaching kinetics of Photofrin. The results allow us to successfully reconcile apparently contradictory experimental observations and to confirm the predictions of a new theoretical model in which both 1O2 and excited triplet sensitizer molecules are allowed to contribute to photobleaching. Based on studies performed in tissue-simulating erythrocyte phantoms and in a murine tumor model in vivo, we present clinically relevant results which indicate that a shift toward increased hemoglobin-oxygen saturation due to improved tissue oxygenation reduces PDT treatment beam attenuation and may allow for more effective treatment of deeper lesions. Finally, we investigate the induction of the stress protein, heat shock protein 70 (HSP

  17. Reduced Endoplasmic Reticulum Luminal Calcium Links Saturated Fatty Acid-Mediated Endoplasmic Reticulum Stress and Cell Death in Liver Cells

    PubMed Central

    Wei, Yuren; Wang, Dong; Gentile, Christopher L.; Pagliassotti, Michael J.

    2010-01-01

    Chronic exposure to elevated free fatty acids, in particular long chain saturated fatty acids, provokes endoplasmic reticulum (ER) stress and cell death in a number of cell types. The perturbations to the ER that instigate ER stress and activation of the unfolded protein in response to fatty acids in hepatocytes have not been identified. The present study employed H4IIE liver cells and primary rat hepatocytes to examine the hypothesis that saturated fatty acids induce ER stress via effects on ER luminal calcium stores. Exposure of H4IIE liver cells and primary hepatocytes to palmitate and stearate reduced thapsigargin-sensitive calcium stores and biochemical markers of ER stress over similar time courses (6h). These changes preceded cell death, which was only observed at later time points (16h). Co-incubation with oleate prevented the reduction in calcium stores, induction of ER stress markers and cell death observed in response to palmitate. Inclusion of calcium chelators, BAPTA-AM or EGTA, reduced palmitate- and stearate-mediated enrichment of cytochrome c in post-mitochondrial supernatant fractions and cell death. These data suggest that redistribution of ER luminal calcium contributes to long chain saturated fatty acid-mediated ER stress and cell death. PMID:19444596

  18. Optical delivery and monitoring of photodynamic therapy of prostate cancer

    NASA Astrophysics Data System (ADS)

    Weersink, Robert A.; Bogaards, Arjun; Gertner, Mark; Davidson, Sean; Zhang, Kai; Netchev, George; Giewercer, David J.; Trachtenberg, John; Wilson, Brian C.

    2004-10-01

    Photodynamic therapy of recurrent prostate cancer is currently undergoing Phase II clinical trials with the vascular targeting drug TOOKAD. Proper PDT dosage requires sound estimates of the light fluence and drug concentration throughout the organ. The treatment requires multiple diffusing light delivery fibers placed in position according to a light dose treatment plan under ultrasound guidance. Fluence rate is monitored by multiple sensor fibers placed throughout the organ and in sensitive organs near the prostate. The combination of multiple light delivery and fluence sensor fibers is used to estimate the optical properties of the tissue and to provide a general fluence map throughout the organ. This fluence map is then used to estimate extent of photodynamic dose. Optical spectroscopy is used to monitor drug pharmacokinetics in the organ and blood hemodynamics within the organ. Further development of these delivery and monitoring techniques will permit full online monitoring of the treatment that will enable real-time patient-specific delivery of photodynamic therapy.

  19. Charge dependent photodynamic activity of alanine based zinc phthalocyanines.

    PubMed

    Wang, Ao; Li, Yejing; Zhou, Lin; Yuan, Linxin; Lu, Shan; Lin, Yun; Zhou, Jiahong; Wei, Shaohua

    2014-12-01

    In this paper, to minimize the effects of different structure, three alanine-based zinc phthalocyanines (Pcs) of differing charges were engineered and synthesized with the same basic structure. On this premise, the relationship between nature of charge and photodynamic activity was studied. Besides, further verification and explanation of some inconsistent results were also carried out. The results showed that charge can influence the aggregation state, singlet oxygen generation ability and cellular uptake of Pcs, thereby affecting their photodynamic activity. In addition, the biomolecules inside cells may interact with Pcs of differing charges, which can also influence the aggregation state and singlet oxygen generation of the Pcs, and then influence the relationship between nature of charge and photodynamic activity.

  20. [Photophysical properties and photodynamic activity of nanostructured aluminium phthalocyanines].

    PubMed

    Udartseva, O O; Lobanov, A V; Andeeva, E R; Dmitrieva, G S; Mel'nikov, M Ia; Buravkova, L B

    2014-01-01

    We developed water-soluble supramolecular complexes of aluminium phthalocyanine based on mesoporous silica nanoparticles and polyvinylpirrolidone containing rare photoactive nanoaggregates. Radiative lifetimes, extinction coefficients and energy of electronic transitions of isolated and associated metal phthalocyanine complexes were calculated. Nontoxic concentrations of synthesized nanocomposite photosensibilizers were in vitro determined. In present study we compared photodynamic treatment efficacy using different modifications of aluminium phthalocyanine (Photosens®, AlPc-nSiO2 and AlPc-PVP). Mesenchymal stromal cells were used as a model for photodynamic treatment. Intracellular accumulation of aluminium phthalocyanine based on mesoporous silica nanoparticles AlPc-nSiO2 was the most efficient. Illumination of phthalocyanine-loaded cells led to reactive oxygen species generation and subsequent apoptotic cell death. Silica nanoparticles provided a significant decrease of effective phthalocyanine concentration and enhanced cytotoxicity of photodynamic treatment.

  1. Influence of bacterial interactions on the susceptibility to photodynamic inactivation

    NASA Astrophysics Data System (ADS)

    Upadya, M. H.; Tegos, G.; Hamblin, M.; Kishen, A.

    2009-06-01

    Photodynamic therapy has emerged as a possible supplement to the existing protocols for endodontic disinfection. Microbes are known to gain significant ecological advantage when they survive as coaggregates and biofilms in an infected tissue. Such microbial coaggregates and biofilms have been confirmed to play a key role in the pathogenicity of many infections. So far, not many studies have correlated the efficacy of antimicrobial photodynamic inactivation (APDI) to the different modes of bacterial growth. This study aims to evaluate the APDI of 3 strains of Enterococcus faecalis in planktonic phase, in a co-aggregated suspension and in a 4-day old biofilm. The results showed that the biofilm mode of growth offered the greatest resistance to APDI and the inclusion of an efflux pump inhibitor significantly increased the APDI of biofilm bacteria. From this study, we conclude that APDI of bacteria in biofilms is the most challenging and that the use of bacterial efflux pump inhibitors enhances its photodynamic antibiofilm efficacy.

  2. Human glioblastoma stem-like cells accumulate protoporphyrin IX when subjected to exogenous 5-aminolaevulinic acid, rendering them sensitive to photodynamic treatment.

    PubMed

    Schimanski, Adrian; Ebbert, Lara; Sabel, Michael C; Finocchiaro, Gaetano; Lamszus, Katrin; Ewelt, Christian; Etminan, Nima; Fischer, Johannes C; Sorg, Rüdiger V

    2016-10-01

    Glioblastoma (GBM) is the most frequent and lethal primary brain tumor in adults. Despite multimodal therapy combining resection, radio- and alkylating chemotherapy, disease recurrence is universal and prognosis of patients is poor. Glioblastoma stem-like cells (GSC), which can be grown as neurospheres from primary tumors in vitro, appear to be resistant to the established therapies and are suspected to be the driving force for disease recurrence. Thus, efficacy of emerging therapies may depend on targeting GSC. 5-aminolaevulinic acid-mediated photodynamic therapy (5-ALA/PDT) is a promising therapeutic approach in GBM. It utilizes the selective accumulation of the photosensitizer protoporphyrin IX (PPIX) in GBM cells after application of 5-ALA. When exposed to laser light of 635nm wavelength, PPIX initiates a photochemical reaction resulting in the generation of reactive oxygen species, which kill the tumor cells. Whether GSC accumulate PPIX and are sensitive to 5-ALA/PDT is currently unknown. Therefore, human GSC were derived from primary tumors and grown as neurospheres under serum free conditions. When subjected to exogenous 5-ALA, a dose- and time-dependent accumulation of PPIX in GSC was observed by flow cytometry, which varied between individual GSC preparations. Subsequent exposure to laser light of 635nm wavelength substantially killed GSC, whereas treatment with 5-ALA or exposure to laser light only had no effect. LD50 values differed between GSC preparations, but were negatively correlated with PPIX accumulation in GSC. In summary, we report for the first time that glioblastoma stem-like cells accumulate PPIX when subjected to 5-aminolaevulinic acid and are sensitive to 5-aminolaevulinc acid based photodynamic therapy. PMID:27588717

  3. Mreg Activity in Tumor Response to Photodynamic Therapy and Photodynamic Therapy-Generated Cancer Vaccines

    PubMed Central

    Korbelik, Mladen; Banáth, Judith; Zhang, Wei

    2016-01-01

    Myeloid regulatory cells (Mregs) are, together with regulatory T cells (Tregs), a dominant effector population responsible for restriction of the duration and strength of antitumor immune response. Photodynamic therapy (PDT) and cancer vaccines generated by PDT are modalities whose effectiveness in tumor destruction is closely dependent on the associated antitumor immune response. The present study investigated whether the immunodepletion of granulocytic Mregs in host mice by anti-GR1 antibody would improve the response of tumors to PDT or PDT vaccines in these animals. Anti-GR1 administration immediately after Temoporfin-PDT of mouse SCCVII tumors abrogated curative effect of PDT. The opposite effect, increasing PDT-mediated tumor cure-rates was attained by delaying anti-GR1 treatment to 1 h post PDT. With PDT vaccines, multiple anti-GR1 administrations (days 0, 4, and 8 post vaccination) improved the therapy response with SCCVII tumors. The results with PDT suggest that neutrophils (boosting antitumor effect of this therapy) that are engaged immediately after photodynamic light treatment are within one hour replaced with a different myeloid population, presumably Mregs that hampers the therapy-mediated antitumor effect. Anti-GR1 antibody, when used with optimal timing, can improve the efficacy of both PDT of tumors in situ and PDT-generated cancer vaccines. PMID:27754452

  4. Photodynamic Therapy: The Imminent Milieu For Treating Oral Lesions

    PubMed Central

    Mohanty, Neeta; Jalaluddin, MD; Kotina, Sreekanth; Routray, Samapika; Ingale, Yashwant

    2013-01-01

    Photodynamic therapy (PDT) is used in curative and palliative treatment of head and neck squamous cell carcinoma (HNSCC) and other oral lesions. Oral infections (such as mucosal and endodontic infections, periodontal diseases, caries, and peri-implantitis) are among the specific targets where PDT can be applied Photodynamic therapy (PDT) efficacy depends on the local dose deposited in the lesion as well as oxygen availability in the lesion. Further long-term clinical studies are necessary in establishing a more specific place of the technique in the field of dentistry. PMID:23905154

  5. New biotinylated phthalocyanines for the photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Hirth, Andreas; Bartik, Bernd; Bogdahn-Rai, Tatjana; Woehrle, Dieter; Kaul, Sepp

    1997-12-01

    Suitable substituted phthalocyanines are promising and widely investigated photosensitizers (PS) for the photodynamic therapy of cancer (PDT). However, selective accumulation of the PSs in tumor tissues, avoiding contamination of healthy tissues, is still an unsolved central problem. We present first results on the synthesis of new biotinylated phthalocyanines as potentially selective photosensitizers when applied in a polyphasic tumor targeting (tumor cell plus first step: biotinylated/monoclonal antibody, second step: streptavidin, and third step: biotinylated PS). The binding and the photodynamic activity of biotinylated PS in this three step model is shown in tumor cell lines.

  6. Photodynamic antimicrobial polymers for infection control.

    PubMed

    McCoy, Colin P; O'Neil, Edward J; Cowley, John F; Carson, Louise; De Baróid, Áine T; Gdowski, Greg T; Gorman, Sean P; Jones, David S

    2014-01-01

    Hospital-acquired infections pose both a major risk to patient wellbeing and an economic burden on global healthcare systems, with the problem compounded by the emergence of multidrug resistant and biocide tolerant bacterial pathogens. Many inanimate surfaces can act as a reservoir for infection, and adequate disinfection is difficult to achieve and requires direct intervention. In this study we demonstrate the preparation and performance of materials with inherent photodynamic, surface-active, persistent antimicrobial properties through the incorporation of photosensitizers into high density poly(ethylene) (HDPE) using hot-melt extrusion, which require no external intervention except a source of visible light. Our aim is to prevent bacterial adherence to these surfaces and eliminate them as reservoirs of nosocomial pathogens, thus presenting a valuable advance in infection control. A two-layer system with one layer comprising photosensitizer-incorporated HDPE, and one layer comprising HDPE alone is also described to demonstrate the versatility of our approach. The photosensitizer-incorporated materials are capable of reducing the adherence of viable bacteria by up to 3.62 Log colony forming units (CFU) per square centimeter of material surface for methicillin resistant Staphylococcus aureus (MRSA), and by up to 1.51 Log CFU/cm(2) for Escherichia coli. Potential applications for the technology are in antimicrobial coatings for, or materials comprising objects, such as tubing, collection bags, handrails, finger-plates on hospital doors, or medical equipment found in the healthcare setting. PMID:25250740

  7. Integrating spheres for improved skin photodynamic therapy.

    PubMed

    Glennie, Diana L; Farrell, Thomas J; Hayward, Joseph E; Patterson, Michael S

    2010-01-01

    The prescribed radiant exposures for photodynamic therapy (PDT) of superficial skin cancers are chosen empirically to maximize the success of the treatment while minimizing adverse reactions for the majority of patients. They do not take into account the wide range of tissue optical properties for human skin, contributing to relatively low treatment success rates. Additionally, treatment times can be unnecessarily long for large treatment areas if the laser power is not sufficient. Both of these concerns can be addressed by the incorporation of an integrating sphere into the irradiation apparatus. The light fluence rate can be increased by as much as 100%, depending on the tissue optical properties. This improvement can be determined in advance of treatment by measuring the reflectance from the tissue through a side port on the integrating sphere, allowing for patient-specific treatment times. The sphere is also effective at improving beam flatness, and reducing the penumbra, creating a more uniform light field. The side port reflectance measurements are also related to the tissue transport albedo, enabling an approximation of the penetration depth, which is useful for real-time light dosimetry. PMID:21054127

  8. Photodynamic therapy on normal rabbit mandible

    NASA Astrophysics Data System (ADS)

    Fan, Kathleen F.; Hopper, Colin; Speight, Paul M.; Davies, Claire; Bown, Stephen G.

    1995-03-01

    Photodynamic therapy has been proposed as an intra-operative adjunct to surgical resection of tumors invading bone. To assess this, we studied the effects of PDT in normal bone. Forty- four rabbits were sensitized with Photofrin 3 mg/kg, 5-aminolaevulinic acid (ALA) 400 mg/kg, or meso-tetrahydroxyphenylchlorin (mTHPC) 0.3 mg/kg. A mandibular incisor was removed and the socket irradiated with a cylindrical diffusion fiber (630 nm Photofrin and ALA, 650 nm mTHPC, 100 J per treatment). Irradiation was given 1 or 48 hours after Photofrin, 72 hours after mTHPC, whilst 2 doses were given 2.5 and 4 hours after the first fractionated dose of ALA. The socket of the ipsilateral maxillary incisor was used as a nonirradiated control to assess healing without PDT. Other controls assessed healing after irradiation of unsensitized animals. Rabbits were killed 3, 10, and 21 days after treatment. Tooth socket healing appeared to be the same in all groups of animals with evidence of woven bone formation by 10 days. We conclude that PDT is unlikely to have any effect on healing in normal bone, which makes it suitable for treating tumors invading bone.

  9. Photodynamic therapy of breast cancer with photosense

    NASA Astrophysics Data System (ADS)

    Vakoulovskaya, Elena G.; Shental, Victor V.; Oumnova, Loubov V.; Vorozhcsov, Georgiu N.

    2003-06-01

    Photodynamic Therapy (PDT) using photosensitizer Photosense (PS) in dose 0.5 mg per kg of body weight have been provided in 24 patients with breast cancer. In 22 patients with T1-T2N0M0 primary tumor was treated as the preoperative treatment, radical mastectomy has been fulfilled 7-10 days after PDT with subsequent histological examination. 2 patients had recurrencies of breast cancer with lymph node metastases after radiotherapy. Fluorescent diagnostics of tumor, accumulation of PS in tumor, adjacent tissue, skin before and during PDT was fulfilled with spectranalyzer LESA-01. We used semiconductive laser for PDT - λ = 672+2nm, P=1,5 W, interstitial irradiation 2-24 hours after PS injection has been done in light dose 150-200 J/cm3, 1-3 irradiations with interval 24-48 hours and total light dose 400-600 J/cm3 depending mostly of size and fluorescent data. Partial regression of tumor with pathomorphosis of 2-4 degrees has been found in 19 cases. Our experience shows pronounced efficacy of PDT for treating breast cancer as preoperative modality and as palliation in cases of recurrencies.

  10. Photodynamic antibacterial effect of graphene quantum dots.

    PubMed

    Ristic, Biljana Z; Milenkovic, Marina M; Dakic, Ivana R; Todorovic-Markovic, Biljana M; Milosavljevic, Momir S; Budimir, Milica D; Paunovic, Verica G; Dramicanin, Miroslav D; Markovic, Zoran M; Trajkovic, Vladimir S

    2014-05-01

    Synthesis of new antibacterial agents is becoming increasingly important in light of the emerging antibiotic resistance. In the present study we report that electrochemically produced graphene quantum dots (GQD), a new class of carbon nanoparticles, generate reactive oxygen species when photoexcited (470 nm, 1 W), and kill two strains of pathogenic bacteria, methicillin-resistant Staphylococcus aureus and Escherichia coli. Bacterial killing was demonstrated by the reduction in number of bacterial colonies in a standard plate count method, the increase in propidium iodide uptake confirming the cell membrane damage, as well as by morphological defects visualized by atomic force microscopy. The induction of oxidative stress in bacteria exposed to photoexcited GQD was confirmed by staining with a redox-sensitive fluorochrome dihydrorhodamine 123. Neither GQD nor light exposure alone were able to cause oxidative stress and reduce the viability of bacteria. Importantly, mouse spleen cells were markedly less sensitive in the same experimental conditions, thus indicating a fairly selective antibacterial photodynamic action of GQD.

  11. Photodynamic therapy: a promising alternative in oncology

    NASA Astrophysics Data System (ADS)

    Nelius, Thomas; de Riese, Werner T. W.; Filleur, Stephanie

    2004-07-01

    Photodynamic Therapy (PDT) is a treatment modality that is based on the administration of a photosensitizer and the following application of light in a wavelength range matching the absorption spectrum of the photosensitizer. Ideally the photosensitizer retains in the tumor tissue more than in normal tissue and thus allows targeted destruction of cancerous tissue. The use of PDT is slowly being accepted as a standard treatment for certain types of cancer. This includes mainly treatment strategies with only palliative intentions (obstructive esophageal cancer and advanced lung cancer) while for certain malignant conditions new applications exists that are already intended for cure (e.g. early stage of lung cancer). The main advantage of PDT is that the treatment can be repeated multiple times safely without major side effects. PDT can be safely combined with already established treatment options like surgery, chemotherapy or radiotherapy. A disadvantage of PDT is the only localized effect of the therapy, which usually cannot significantly alter the outcome of a systemic disease. In this paper we review the history of PDT as well as current clinical applications in oncology and future directions.

  12. PDT Dose Dosimeter for Pleural Photodynamic Therapy

    PubMed Central

    Kim, Michele M.; Darafsheh, Arash; Ahmad, Mahmoud; Finlay, Jarod C.; Zhu, Timothy C.

    2016-01-01

    PDT dose is the product of the photosensitizer concentration and the light fluence in the target tissue. For improved dosimetry during plural photodynamic therapy (PDT), a PDT dose dosimeter was developed to measure both the light fluence and the photosensitizer concentration simultaneously in the same treatment location. Light fluence and spectral data were rigorously compared to other methods of measurement (e.g. photodiode, multi-fiber spectroscopy contact probe) to assess the accuracy of the measurements as well as their uncertainty. Photosensitizer concentration was obtained by measuring the fluorescence of the sensitizer excited by the treatment light. Fluence rate based on the intensity of the laser spectrum was compared to the data obtained by direct measurement of fluence rate by a fiber-coupled photodiode. Phantom studies were done to obtain an optical property correction for the fluorescence signal. Measurements were performed in patients treated Photofrin for different locations in the pleural cavity. Multiple sites were measured to investigate the heterogeneity of the cavity and to provide cross-validation via relative dosimetry. This novel method will allow for accurate real-time determination of delivered PDT dose and improved PDT dosimetry. PMID:27053825

  13. Photodynamic therapy (PDT) for lung cancer

    NASA Astrophysics Data System (ADS)

    Moghissi, K.; Dixon, Kate

    2005-11-01

    The Yorkshire Laser Centre has been engaged in Photodynamic Therapy (PDT) since 1990. In this article we present our experience highlighting the lesson learnt. 280 bronchoscopic PDT treatments have been carried out in 160 patients divided in 2 groups. Group A: (Nr 144) with advanced inoperable disease and Group E (Nr 16) with early stage cancer. PDT method was intravenous administration of 2mg/kg bw of Photofrin followed by bronchoscopic illumination of 630nm laser light. There was no procedure-related mortality. A total of 9 cases of photosensitivity (skin burn) occurred in the series (5.6% of patients). Every patient in both groups expressed their total satisfaction to treatment. Group A: Symptom relief was achieved in all. This was matched by improvement in significant bronchial opening (58.1%). Survival was 9.6 months (mean).This was greater in patients with better performance status and lower stage of disease. Group E: Every patient had a complete response to treatment. Survival in this group was 75.4 months (mean). We conclude that bronchoscopic PDT is indicated in both advanced and early stage lung cancer. In the former it provides symptomatic relief in all and survival benefit in some; in the latter it achieves long survival and potential cure.

  14. Novel Photodynamics in Phytochrome & Cyanobacteriochrome Photosensory Proteins

    NASA Astrophysics Data System (ADS)

    Larsen, Delmar

    2015-03-01

    The photodynamics of recently characterized phytochrome and cyanobacteriochrome photoreceptors are discussed. Phytochromes are red/far-red photosensory proteins that utilize the photoisomerization of a linear tetrapyrrole (bilin) chromophore to detect the red to far-red light ratio. Cyanobacteriochromes (CBCRs) are distantly related cyanobacterial photosensors with homologous bilin-binding GAF domains, but exhibit greater spectral diversity. The excited-state mechanisms underlying the initial photoisomerization in the forward reactions of the cyanobacterial photoreceptor Cph1 from Synechocystis, the RcaE CBCR from Fremyella diplosiphon, and Npr6012g4 CBCR from Nostoc punctiforme were contrasted via multipulse pump-dump-probe transient spectroscopy. A rich excited-state dynamics are resolved involving a complex interplay of excited-state proton transfer, photoisomerization, multilayered inhomogeneity, and reactive intermediates, and Le Chatelier redistribution. NpR6012g4 exhibits a high quantum yield for its forward photoreaction (40%) that was ascribed to the activity of hidden, productive ground-state intermediates via a ``second chance initiation dynamics'' (SCID) mechanism. This work was supported by a grant from the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, United States Department of Energy (DOE DE-FG02-09ER16117).

  15. Melanoma resistance to photodynamic therapy: new insights

    PubMed Central

    Huang, Ying-Ying; Vecchio, Daniela; Avci, Pinar; Yin, Rui; Garcia-Diaz, Maria; Hamblin, Michael R.

    2012-01-01

    Melanoma is the most dangerous form of skin cancer, with a steeply rising incidence and a poor prognosis in its advanced stages. Melanoma is highly resistant to traditional chemotherapy and radiotherapy, although modern targeted therapies such as BRAF inhibitors are showing some promise. Photodynamic therapy (PDT, the combination of photosensitizing dyes and visible light) has been tested for melanoma with some promising results, but melanoma is generally considered to also be resistant to PDT. Optical interference by the highly-pigmented melanin, the anti-oxidant effect of melanin, the sequestration of photosensitizers inside melanosomes, defects in apoptotic pathways, and the efflux of photosensitizers by ATP-binding cassette (ABC) transporters have all been implicated in melanoma resistance to PDT. Approaches to overcoming melanoma resistance to PDT include: the discovery of highly active photosensitizers absorbing in the 700–800-nm near infrared spectral region; interventions that can temporarily reduce the amount or the pigmentation of the melanin; compounds that can reverse apoptotic defects or inhibit drug-efflux of photosensitizers; and immunotherapy approaches that can take advantage of the ability of PDT to activate the host immune system to the treated tumor. PMID:23152406

  16. Integrating spheres for improved skin photodynamic therapy.

    PubMed

    Glennie, Diana L; Farrell, Thomas J; Hayward, Joseph E; Patterson, Michael S

    2010-01-01

    The prescribed radiant exposures for photodynamic therapy (PDT) of superficial skin cancers are chosen empirically to maximize the success of the treatment while minimizing adverse reactions for the majority of patients. They do not take into account the wide range of tissue optical properties for human skin, contributing to relatively low treatment success rates. Additionally, treatment times can be unnecessarily long for large treatment areas if the laser power is not sufficient. Both of these concerns can be addressed by the incorporation of an integrating sphere into the irradiation apparatus. The light fluence rate can be increased by as much as 100%, depending on the tissue optical properties. This improvement can be determined in advance of treatment by measuring the reflectance from the tissue through a side port on the integrating sphere, allowing for patient-specific treatment times. The sphere is also effective at improving beam flatness, and reducing the penumbra, creating a more uniform light field. The side port reflectance measurements are also related to the tissue transport albedo, enabling an approximation of the penetration depth, which is useful for real-time light dosimetry.

  17. PDT dose dosimeter for pleural photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Kim, Michele M.; Darafsheh, Arash; Ahmad, Mahmoud; Finlay, Jarod C.; Zhu, Timothy C.

    2016-03-01

    PDT dose is the product of the photosensitizer concentration and the light fluence in the target tissue. For improved dosimetry during plural photodynamic therapy (PDT), a PDT dose dosimeter was developed to measure both the light fluence and the photosensitizer concentration simultaneously in the same treatment location. Light fluence and spectral data were rigorously compared to other methods of measurement (e.g. photodiode, multi-fiber spectroscopy contact probe) to assess the accuracy of the measurements as well as their uncertainty. Photosensitizer concentration was obtained by measuring the fluorescence of the sensitizer excited by the treatment light. Fluence rate based on the intensity of the laser spectrum was compared to the data obtained by direct measurement of fluence rate by a fiber-coupled photodiode. Phantom studies were done to obtain an optical property correction for the fluorescence signal. Measurements were performed in patients treated Photofrin for different locations in the pleural cavity. Multiple sites were measured to investigate the heterogeneity of the cavity and to provide cross-validation via relative dosimetry. This novel method will allow for accurate real-time determination of delivered PDT dose and improved PDT dosimetry.

  18. Photodynamic therapy of advanced malignant tumors

    NASA Astrophysics Data System (ADS)

    Wang, Lian-xing; Dai, Lu-pin; Lu, Wen-qin

    1993-03-01

    Forty patients with advanced tumors were treated by photodynamic therapy (PDT) from May 1991 to August 1991 in our hospital with age ranges from 30 to 81 years old. The pathological diagnosis shows that 13 had tumors in the colon, 3 in the stomach, 2 in the oesophageal, 2 in the palatum, 1 in the cervix, and 19 others with malignant cancers of the skin. The histology was as follows: squamous cell in 20, adenocarcinoma in 19, melanocarcinoma in 1. By TNM classification there were no cases of T1, 5 cases of T2, and 35 cases of T2 - T3. All patients were stage IV. The overall effective rate was 85%, our experience is that the PDT is suitable for the patients with advanced tumor, especially those whose tumor recurrences are hard to treat after conventional treatment (surgery, radiotherapy, chemotherapy). The PDT appears to be a new and promising possibility to treat advanced tumors and to improve the patients' survival rates.

  19. Photodynamic therapy of recurrent cerebral glioma

    NASA Astrophysics Data System (ADS)

    Zhu, Shu-Gan; Wu, Si-En; Chen, Zong-Qian; Sun, Wei

    1993-03-01

    Photodynamic therapy (PDT) was performed on 11 cases of recurrent cerebral glioma, including 3 cases of recurrent glioblastoma, 7 of recurrent anaplastic astrocytoma, and 1 recurrent ependymoma. Hematoporphyrin derivative (HPD) was administered intravenously at a dose of 4 - 7 mg/kg 5 - 24 hours before the operation. All patients underwent a craniotomy with a nearly radical excision of the tumor following which the tumor bed was irradiated with 630 nm laser light emitting either an argon pumped dye laser or frequency double YAG pumped dye laser for 30 to 80 minutes with a total dose of 50 J/cm2 (n equals 1), 100 J/cm2 (n equals 2), 200 J/cm2 (n equals 7), and 300 J/cm2 (n equals 1). The temperature was kept below 37 degree(s)C by irrigation. Two patients underwent postoperative radiotherapy. There was no evidence of increased cerebral edema, and no other toxicity by the therapy. All patients were discharged from the hospital within 15 days after surgery. We conclude that PDT using 4 - 7 mg/kg of HPD and 630 nm light with a dose of up to 300 J/cm2 can be used as an adjuvant therapy with no additional complications. Adjuvant PDT in the treatment of recurrent glioma is better than simple surgery.

  20. Combination immunotherapy and photodynamic therapy for cancer

    NASA Astrophysics Data System (ADS)

    Hamblin, Michael R.; Castano, Ana P.; Mroz, Pawel

    2006-02-01

    Cancer is a leading cause of death among modern people largely due to metastatic disease. The ideal cancer treatment should target both the primary tumor and the metastases with minimal toxicity towards normal tissue. This is best accomplished by priming the body's immune system to recognize the tumor antigens so that after the primary tumor is destroyed, distant metastases will also be eradicated. Photodynamic therapy (PDT) involves the IV administration of photosensitizers followed by illumination of the tumor with red light producing reactive oxygen species leading to vascular shutdown and tumor cell death. Anti-tumor immunity is stimulated after PDT due to the acute inflammatory response, generation of tumor-specific antigens, and induction of heat-shock proteins. Combination regimens using PDT and immunostimulating treatments are likely to even further enhance post-PDT immunity. These immunostimulants are likely to include products derived from pathogenic microorganisms that are effectively recognized by Toll-like receptors and lead to upregulation of transcription factors for cytokines and inflammatory mediators. The following cascade of events causes activation of macrophages, dendritic and natural killer cells. Exogenous cytokine administration can be another way to increase PDT-induced immunity as well as treatment with a low dose of cyclophosphamide that selectively reduces T-regulatory cells. Although so far these combination therapies have only been used in animal models, their use in clinical trials should receive careful consideration.

  1. Photodynamic therapy (PDT) as a biological modifier

    NASA Astrophysics Data System (ADS)

    Obochi, Modestus; Tao, Jing-Song; Hunt, David W. C.; Levy, Julia G.

    1996-04-01

    The capacity of photosensitizers and light to ablate cancerous tissues and unwanted neovasculature constitutes the classical application of photodynamic therapy (PDT). Cell death results from either necrotic or apoptotic processes. The use of photosensitizers and light at doses which do not cause death has been found to affect changes in certain cell populations which profoundly effect their expression of cell surface molecules and secretion of cytokines, thereby altering the functional attributes of the treated cells. Cells of the immune system and the skin may be sensitive to modulation by 'sub-lethal PDT.' Ongoing studies have been conducted to assess, at the molecular level, changes in both lymphocytes and epidermal cells (EC) caused by treatment with low levels of benzoporphyrin derivative monoacid ring A (BPD) (a photosensitizer currently in clinical trials for cancer, psoriasis, endometriosis and age-related macular degeneration) and light. Treatment of skin with BPD and light, at levels which significantly enhanced the length of murine skin allograft acceptance, have been found to down-regulate the expression of Langerhans cell (LC) surface antigen molecules [major histocompatibility complex (MHC) class II and intracellular adhesion molecule (ICAM)-1] and the formation of some cytokines (tumor necrosis factor-alpha (TNF- (alpha) ).

  2. Photodynamic Antimicrobial Polymers for Infection Control

    PubMed Central

    McCoy, Colin P.; O’Neil, Edward J.; Cowley, John F.; Carson, Louise; De Baróid, Áine T.; Gdowski, Greg T.; Gorman, Sean P.; Jones, David S.

    2014-01-01

    Hospital-acquired infections pose both a major risk to patient wellbeing and an economic burden on global healthcare systems, with the problem compounded by the emergence of multidrug resistant and biocide tolerant bacterial pathogens. Many inanimate surfaces can act as a reservoir for infection, and adequate disinfection is difficult to achieve and requires direct intervention. In this study we demonstrate the preparation and performance of materials with inherent photodynamic, surface-active, persistent antimicrobial properties through the incorporation of photosensitizers into high density poly(ethylene) (HDPE) using hot-melt extrusion, which require no external intervention except a source of visible light. Our aim is to prevent bacterial adherence to these surfaces and eliminate them as reservoirs of nosocomial pathogens, thus presenting a valuable advance in infection control. A two-layer system with one layer comprising photosensitizer-incorporated HDPE, and one layer comprising HDPE alone is also described to demonstrate the versatility of our approach. The photosensitizer-incorporated materials are capable of reducing the adherence of viable bacteria by up to 3.62 Log colony forming units (CFU) per square centimeter of material surface for methicillin resistant Staphylococcus aureus (MRSA), and by up to 1.51 Log CFU/cm2 for Escherichia coli. Potential applications for the technology are in antimicrobial coatings for, or materials comprising objects, such as tubing, collection bags, handrails, finger-plates on hospital doors, or medical equipment found in the healthcare setting. PMID:25250740

  3. Photodynamic Therapy for Infections: Clinical Applications

    PubMed Central

    Kharkwal, Gitika B.; Sharma, Sulbha K.; Huang, Ying-Ying; Dai, Tianhong; Hamblin, Michael R.

    2012-01-01

    Background and Objective Photodynamic therapy (PDT) was discovered over 100 years ago by its ability to kill various microorganisms when the appropriate dye and light were combined in the presence of oxygen. However it is only in relatively recent times that PDT has been studied as a treatment for various types of localized infections. This resurgence of interest has been partly motivated by the alarming increase in drug resistance amongst bacteria and other pathogens. This review will focus on the clinical applications of antimicrobial PDT. Study Design/Materials and Methods The published peer-reviewed literature was reviewed between 1960 and 2011. Results The basics of antimicrobial PDT are discussed. Clinical applications of antimicrobial PDT to localized viral infections caused by herpes and papilloma viruses, and nonviral dermatological infections such as acne and other yeast, fungal and bacterial skin infections are covered. PDT has been used to treat bacterial infections in brain abscesses and non-healing ulcers. PDT for dental infections including periodontitis and endodontics has been well studied. PDT has also been used for cutaneous Leishmaniasis. Clinical trials of PDT and blue light alone therapy for gastric Helicobacter pylori infection are also covered. Conclusion As yet clinical PDT for infections has been mainly in the field of dermatology using 5-aminolevulanic acid and in dentistry using phenothiazinium dyes. We expect more to see applications of PDT to more challenging infections using advanced antimicrobial photosensitizers targeted to microbial cells in the years to come. PMID:22057503

  4. Photodynamic inactivation of pathogens causing infectious keratitis

    NASA Astrophysics Data System (ADS)

    Simon, Carole; Wolf, G.; Walther, M.; Winkler, K.; Finke, M.; Hüttenberger, D.; Bischoff, Markus; Seitz, B.; Cullum, J.; Foth, H.-J.

    2014-03-01

    The increasing prevalence of antibiotic resistance requires new approaches also for the treatment of infectious keratitis. Photodynamic Inactivation (PDI) using the photosensitizer (PS) Chlorin e6 (Ce6) was investigated as an alternative to antibiotic treatment. An in-vitro cornea model was established using porcine eyes. The uptake of Ce6 by bacteria and the diffusion of the PS in the individual layers of corneal tissue were investigated by fluorescence. After removal of the cornea's epithelium Ce6-concentrations < 1 mM were sufficient to reach a penetration depth of 500 μm. Liquid cultures of microorganisms were irradiated using a specially constructed illumination chamber made of Spectralon(R) (reflectance: 99 %), which was equipped with high power light emitting diodes (λ = 670 nm). Clinical isolates of Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) from keratitis patients were tested in liquid culture against different concentrations of Ce6 (1 - 512 μM) using 10 minutes irradiation (E = 18 J/cm2 ). This demonstrated that a complete inactivation of the pathogen strains were feasible whereby SA was slightly more susceptible than PA. 3909 mutants of the Keio collection of Escherichia coli (E.coli) were screened for potential resistance factors. The sensitive mutants can be grouped into three categories: transport mutants, mutants in lipopolysaccharide synthesis and mutants in the bacterial SOS-response. In conclusion PDI is seen as a promising therapy concept for infectious keratitis.

  5. Optical dosimetry for interstitial photodynamic therapy

    SciTech Connect

    Arnfield, M.R.; Tulip, J.; Chetner, M.; McPhee, M.S. )

    1989-07-01

    An approach to photodynamic treatment of tumors is the interstitial implantation of fiber optic light sources. Dosimetry is critical in identifying regions of low light intensity in the tumor which may prevent tumor cure. We describe a numerical technique for calculating light distributions within tumors, from multiple fiber optic sources. The method was tested using four translucent plastic needles, which were placed in a 0.94 X 0.94 cm grid pattern within excised Dunning R3327-AT rat prostate tumors. A cylindrical diffusing fiber tip, illuminated by 630 nm dye laser light was placed within one needle and a miniature light detector was placed within another. The average penetration depth in the tumor region between the two needles was calculated from the optical power measured by the detector, using a modified diffusion theory. Repeating the procedure for each pair of needles revealed significant variations in penetration depth within individual tumors. Average values of penetration depth, absorption coefficient, scattering coefficient, and mean scattering cosine were 0.282 cm, 0.469 cm-1, 250 cm-1 and 0.964, respectively. Calculated light distributions from four cylindrical sources in tumors gave reasonable agreement with direct light measurements using fiber optic probes.

  6. Photodynamic therapy for port wine stains

    NASA Astrophysics Data System (ADS)

    Li, Junheng

    1998-08-01

    Therapies for port wine stains including conventional laser irradiation usually cause unacceptable scarring or obtain poor effect. Pulsed dye laser has better approach, but only few patients obtain complete fading after multiple laser treatment. Because port wine stain is a congenital vasculopathy consisting of an abnormal network of capillaries in the upper dermis with an overlying normal epidermis and the researchers found that tumor blood vessels were occluded accompanying the necrosis of the tumor after PDT. It is though to be the effect primarily by thrombus formation in vessels and shut down of the blood supply to the tumor as well as direct tumor cells kill. The author and his colleagues started a series of animal and clinical studies since 1991 about photodynamic therapy for port wine stains and they established the method of PDT for PWS. An experimental study showed that Hpd appeared rapidly within the human vascular endothelial cells in culture fluid. Animal study using chicken combs as PWS models treated by PDT revealed the possibility of selective destruction of the malformative vasculature in PWS. The clinical studies of over 1700 cases proved that PWS can be cured without scar formation by PDT because there is no thermal effect involved. No relapse was found within a maximum follow-up of seven years. The differences and mechanism between the treatments of PDT and conventional lasers are discussed.

  7. Tissue temperature monitoring during interstitial photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Svensson, Jenny; Johansson, Ann; Svanberg, Katarina; Andersson-Engels, Stefan

    2005-04-01

    During δ-aminolevulinic acid (ALA) based Interstitial Photodynamic Therapy (IPDT) a high light fluence rate is present close to the source fibers. This might induce an unintentional tissue temperature increase of importance for the treatment outcome. In a previous study, we have observed, that the absorption in the tissue increases during the treatment. A system to measure the local tissue temperature at the source fibers during IPDT on tissue phantoms is presented. The temperature was measured by acquiring the fluorescence from small Cr3+-doped crystals attached to the tip of the illumination fiber used in an IPDT-system. The fluorescence of the Alexandrite crystal used is temperature dependent. A ratio of the intensity of the fluorescence was formed between two different wavelength bands in the red region. The system was calibrated by immersing the fibers in an Intralipid solution placed in a temperature controlled oven. Measurements were then performed by placing the fibers interstitially in a pork chop as a tissue phantom. Measurements were also performed superficially on skin on a volunteer. A treatment was conducted for 10 minutes, and the fluorescence was measured each minute during the illumination. The fluorescence yielded the temperature at the fiber tip through the calibration curve. The measurements indicate a temperature increase of a few degrees during the simulated treatment.

  8. Pecularities of clinical photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Stranadko, Eugeny P.; Skobelkin, Oleg K.; Litvin, Grigory D.; Astrakhankina, Tamara A.

    1996-01-01

    The analysis of the results of photodynamic therapy (PDT) for treating malignant neoplasms of the skin, mammary glands, tongue, oral mucous, lower lip, larynx, lungs, urinary bladder rectum and other locations has been made. During 1992 - 1995 478 tumoral foci in 125 patients have been treated with PDT. All patients were previously treated with conventional techniques without effect or they were not treated due to contraindications either because of severe accompanying diseases or because of old age. A part of the patients had PDT because of recurrences or intradermal metastases in 1 - 2 years after surgical, radial or combined treatment. Two home-made preparations were used as photosensitizers: Photohem (hematoporphyrine derivative) and Photosense (aluminum sulfonated phthalocyanine). Light sources were: the argon pumped dye laser (`Innova-200', `Coherent') and home-made laser devices: copper-vapor laser-pumped dye laser (`Yakhroma-2', Frjazino), gas-discharge unit `Ksenon' (wavelength 630 nm), gold-vapor laser (wavelength 627.8 nm) for Photohem; while for Photosense sessions we used solid-state laser on ittrium aluminate `Poljus-1' (wavelength 670 nm). Up to now we have follow-up control data within 2 months and 3 years. Positive effect of PDT was seen in 92% of patients including complete regression of tumors in 66.4% and partial in 25.6%. Currently, this new perspective technique of treating malignant neoplasms is successfully being used in Russia; new photosensitizers and light sources for PDT and fluorescent tumor diagnostics are being developed as well.

  9. Photochemical predictive analysis of photodynamic therapy in dermatology

    NASA Astrophysics Data System (ADS)

    Fanjul-Vélez, F.; Salas-García, I.; López-Escobar, M.; Ortega-Quijano, N.; Arce-Diego, J. L.

    2010-02-01

    Photodynamic Therapy is a recent treatment modality that allows malignant tissue destruction. The technique provides a localized effect and good cosmetic results. The application of Photodynamic Therapy is based on the inoculation of a photosensitizer and the posterior irradiation by an optical source. This radiation chemically activates the drug and provokes reactions that lead to tissue necrosis. Nowadays there are fixed clinical Photodynamic Therapy protocols that make use of a particular optical dose and photosensitizer amount. These parameters are independent of the patient and the lesion. In this work we present a Photodynamic Therapy model that tries to predict the effect of the treatment on the skin. First the results of a clinical study in the Dermatology Department of the Marqués de Valdecilla University Hospital are presented. The most common lesions and some unsuccessful cases are stated. The predictive model proposed is based on a 3D optical propagation of radiation by a Monte Carlo approach. Once the optical energy is obtained, a complex photochemical model is employed. This model takes into account the electronic transitions between molecular levels and particles concentrations. As the process of generation of photosensitizer is not homogeneous, the photosensitizer distribution is also taken into account. The optical power of the source, the exposition time and the optochemical characteristics of the tissue can be varied. This implies that these parameters could be adjusted to the particular pathology we are dealing with, so the unsuccessful cases could be better treated.

  10. Photodynamic Therapy in Treatment of Oral Lichen Planus

    PubMed Central

    Mostafa, Diana; Tarakji, Bassel

    2015-01-01

    Oral lichen planus (OLP) is a relatively common chronic immunologic mucocutaneous disorder. Although there are many presenting treatments, some of them proved its failure. Recently, the use of photodynamic therapy (PDT) has been expanding due to its numerous advantages, as it is safe, convenient, and non-invasive and has toxic effect towards selective tissues. This article provides comprehensive review on OLP, its etiology, clinical features and recent non-pharmacological treatments. We also describe the topical PDT and its mechanisms. Our purpose was to evaluate the efficacy of PDT in treatment of OLP through collecting the data of the related clinical studies. We searched in PubMed website for the clinical studies that were reported from 2000 to 2014 using specific keywords: “photodynamic therapy” and “treatment of oral lichen planus”. Inclusion criteria were English publications only were concerned. In the selected studies of photodynamic treatment, adult patients (more than 20 years) were conducted and the OLP lesions were clinically and histologically confirmed. Exclusion criteria were classical and pharmacological treatments of OLP were excluded and also the using of PDT on skin lesions of lichen planus. We established five clinical studies in this review where all of them reported improvement and effectiveness of PDT in treatment of OLP lesions. The main outcome of comparing the related clinical studies is that the photodynamic is considered as a safe, effective and promising treatment modality for OLP. PMID:25883701

  11. Photodynamic Inactivation of Bacteria and Biofilms Using Cationic Bacteriochlorins

    NASA Astrophysics Data System (ADS)

    Meerovich, G. A.; Tiganova, I. G.; Makarova, E. A.; Meerovich, I. G.; Romanova Ju., M.; Tolordova, E. R.; Alekseeva, N. V.; Stepanova, T. V.; Yu, Koloskova; Luk'anets, E. A.; Krivospitskaya, N. V.; Sipailo, I. P.; Baikova, T. V.; Loschenov, V. B.; Gonchukov, S. A.

    2016-02-01

    This work is devoted to the study of two new synthetic bacteriochlorins with four and eight cationic substitutes as the photosensitizers in the photodynamic process. The spectral and antibacterial properties of these photosensitizers in saline solution were investigated. It is shown, that the aggregation ability decreases and the antibacterial efficiency grows as the cationic substitute number increases.

  12. Photodynamically crosslinked and chitosan-incorporated dentin collagen.

    PubMed

    Shrestha, A; Friedman, S; Kishen, A

    2011-11-01

    A lingering concern with restored root-filled teeth is the loss of structural integrity of the dentin and dentin-sealer interface over time. We hypothesized that crosslinking of dentin collagen with simultaneous incorporation of a biopolymer into collagen matrix would improve its structural stability. This study aimed to investigate the effects of combining chemical/photodynamic crosslinking of dentin collagen with the incorporation of carboxymethyl-chitosan (CMCS) on the resistance to enzymatic degradation and mechanical properties of dentin collagen. Ninety-six demineralized dentin collagen specimens (human, n = 72; and bovine, n = 24) were prepared and crosslinked chemically/ photodynamically, with/without CMCS. Glutaraldehyde and carbodiimides were used for chemical crosslinking, while rose Bengal activated with a non-coherent light (540 nm) at 20 J/cm(2) was applied for photodynamic crosslinking. The crosslinked human dentin collagen was subjected to chemical characterization, 7 days enzymatic degradation, and transmission electron microscopy (TEM), while the bovine dentin collagen was used for tensile-testing. Crosslinked collagen showed significantly higher resistance to enzymatic degradation (p < 0.01), stable ultrastructure, and increased tensile strength (p < 0.05). Crosslinking CMCS with collagen matrix as observed in the TEM further improved the mechanical properties of dentin collagen (p < 0.01). This study highlighted the possibility of improving the resistance and toughness of dentin collagen by chemically/photodynamically crosslinking collagen matrix with CMCS.

  13. Suppression of cucurbit scab on cucumber leaves by photodynamic dyes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this study was to test the ability of the photodynamic dyes bengal rose, toluidine blue, and methylene blue, to protect systemically cucumber plants from cucurbit scab. At the stage of one true leaf, water or aqueous solutions of the dyes were applied to the leaf as droplets. When the se...

  14. Effect of photodynamic therapy on a heterotransplanted human parotid tumor.

    PubMed

    Christensen, N R; Charabi, S; Johansen, L S; Rygaard, J; Balle, V H; Tos, M; Thomsen, J

    2000-07-01

    To evaluate the effect of photodynamic therapy on human parotid tumors we used tumor specimens obtained from parotid surgery on a consecutive group of patients. The tumors were transplanted into a subcutaneous pocket of nude mice. The original human tumors were pleomorphic adenoma (four), adenolymphoma (one), acinic cell carcinoma (one), sarcoma (one) and low-grade adenocarcinoma (one). The most aggressive growth was seen in the low-grade adenocarcinoma. We re-implanted this tumor on ten mice bilaterally, and treated the tumors with photodynamic therapy (PDT), resulting in a mean depth of tumor necrosis of 5.4 mm (1-10 mm). In three cases we found vital tumor cells in the periphery of the tumor after treatment, with several new blood vessels in the surrounding tissue, indicating a great potential for neo-angiogenesis in this tumor. In order to evaluate the possible nerve damage subsequent to the photodynamic therapy, the ischiadic nerve in 24 lower limbs of nude mice were investigated. In one case only the macroscopical and histological investigation revealed signs of nerve damage. The current study demonstrates that the nude mice implantation model is excellent to investigate growth in both malignant and benign parotid tumors, and to test new therapeutic modalities. Photodynamic therapy seems to have a possible role in the future management of the malignant lesions of the parotid gland, in cases where radical surgery for some reason is not achievable. PMID:10808112

  15. Important cellular targets for antimicrobial photodynamic therapy.

    PubMed

    Awad, Mariam M; Tovmasyan, Artak; Craik, James D; Batinic-Haberle, Ines; Benov, Ludmil T

    2016-09-01

    The persistent problem of antibiotic resistance has created a strong demand for new methods for therapy and disinfection. Photodynamic inactivation (PDI) of microbes has demonstrated promising results for eradication of antibiotic-resistant strains. PDI is based on the use of a photosensitive compound (photosensitizer, PS), which upon illumination with visible light generates reactive species capable of damaging and killing microorganisms. Since photogenerated reactive species are short lived, damage is limited to close proximity of the PS. It is reasonable to expect that the larger the number of damaged targets is and the greater their variety is, the higher the efficiency of PDI is and the lower the chances for development of resistance are. Exact molecular mechanisms and specific targets whose damage is essential for microbial inactivation have not been unequivocally established. Two main cellular components, DNA and plasma membrane, are regarded as the most important PDI targets. Using Zn porphyrin-based PSs and Escherichia coli as a model Gram-negative microorganism, we demonstrate that efficient photoinactivation of bacteria can be achieved without detectable DNA modification. Among the cellular components which are modified early during illumination and constitute key PDI targets are cytosolic enzymes, membrane-bound protein complexes, and the plasma membrane. As a result, membrane barrier function is lost, and energy and reducing equivalent production is disrupted, which in turn compromises cell defense mechanisms, thus augmenting the photoinduced oxidative injury. In conclusion, high PDI antimicrobial effectiveness does not necessarily require impairment of a specific critical cellular component and can be achieved by inducing damage to multiple cellular targets. PMID:27221289

  16. Photodynamic Therapy for Malignant Brain Tumors

    PubMed Central

    AKIMOTO, Jiro

    2016-01-01

    Photodynamic therapy (PDT) using talaporfin sodium together with a semiconductor laser was approved in Japan in October 2003 as a less invasive therapy for early-stage lung cancer. The author believes that the principle of PDT would be applicable for controlling the invading front of malignant brain tumors and verified its efficacy through experiments using glioma cell lines and glioma xenograft models. An investigator-initiated clinical study was jointly conducted with Tokyo Women’s Medical University with the support of the Japan Medical Association. Patient enrollment was started in May 2009 and a total of 27 patients were enrolled by March 2012. Of 22 patients included in efficacy analysis, 13 patients with newly diagnosed glioblastoma showed progression-free survival of 12 months, progression-free survival at the site of laser irradiation of 20 months, 1-year survival of 100%, and overall survival of 24.8 months. In addition, the safety analysis of the 27 patients showed that adverse events directly related to PDT were mild. PDT was approved in Japan for health insurance coverage as a new intraoperative therapy with the indication for malignant brain tumors in September 2013. Currently, the post-marketing investigation in the accumulated patients has been conducted, and the preparation of guidelines, holding training courses, and dissemination of information on the safe implementation of PDT using web sites and videos, have been promoted. PDT is expected to be a breakthrough for the treatment of malignant glioma as a tumor cell-selective less invasive therapy for the infiltrated functional brain area. PMID:26888042

  17. Animal models for photodynamic therapy (PDT)

    PubMed Central

    Silva, Zenildo Santos; Bussadori, Sandra Kalil; Fernandes, Kristianne Porta Santos; Huang, Ying-Ying; Hamblin, Michael R.

    2015-01-01

    Photodynamic therapy (PDT) employs non-toxic dyes called photosensitizers (PSs), which absorb visible light to give the excited singlet state, followed by the long-lived triplet state that can undergo photochemistry. In the presence of ambient oxygen, reactive oxygen species (ROS), such as singlet oxygen and hydroxyl radicals are formed that are able to kill cancer cells, inactivate microbial pathogens and destroy unwanted tissue. Although there are already several clinically approved PSs for various disease indications, many studies around the world are using animal models to investigate the further utility of PDT. The present review will cover the main groups of animal models that have been described in the literature. Cancer comprises the single biggest group of models including syngeneic mouse/rat tumours that can either be subcutaneous or orthotopic and allow the study of anti-tumour immune response; human tumours that need to be implanted in immunosuppressed hosts; carcinogen-induced tumours; and mice that have been genetically engineered to develop cancer (often by pathways similar to those in patients). Infections are the second biggest class of animal models and the anatomical sites include wounds, burns, oral cavity, ears, eyes, nose etc. Responsible pathogens can include Gram-positive and Gram-negative bacteria, fungi, viruses and parasites. A smaller and diverse group of miscellaneous animal models have been reported that allow PDT to be tested in ophthalmology, atherosclerosis, atrial fibrillation, dermatology and wound healing. Successful studies using animal models of PDT are blazing the trail for tomorrow's clinical approvals. PMID:26415497

  18. Photodynamic Therapy for Malignant Brain Tumors.

    PubMed

    Akimoto, Jiro

    2016-01-01

    Photodynamic therapy (PDT) using talaporfin sodium together with a semiconductor laser was approved in Japan in October 2003 as a less invasive therapy for early-stage lung cancer. The author believes that the principle of PDT would be applicable for controlling the invading front of malignant brain tumors and verified its efficacy through experiments using glioma cell lines and glioma xenograft models. An investigator-initiated clinical study was jointly conducted with Tokyo Women's Medical University with the support of the Japan Medical Association. Patient enrollment was started in May 2009 and a total of 27 patients were enrolled by March 2012. Of 22 patients included in efficacy analysis, 13 patients with newly diagnosed glioblastoma showed progression-free survival of 12 months, progression-free survival at the site of laser irradiation of 20 months, 1-year survival of 100%, and overall survival of 24.8 months. In addition, the safety analysis of the 27 patients showed that adverse events directly related to PDT were mild. PDT was approved in Japan for health insurance coverage as a new intraoperative therapy with the indication for malignant brain tumors in September 2013. Currently, the post-marketing investigation in the accumulated patients has been conducted, and the preparation of guidelines, holding training courses, and dissemination of information on the safe implementation of PDT using web sites and videos, have been promoted. PDT is expected to be a breakthrough for the treatment of malignant glioma as a tumor cell-selective less invasive therapy for the infiltrated functional brain area. PMID:26888042

  19. Immunologic Effects Of Peritoneal Photodynamic Treatment

    NASA Astrophysics Data System (ADS)

    Lynch, David H.; Haddad, Sandra; Jolles, Christopher J.; King, Vernon J.; Ott, Mark J.; Robertson, Bekkie; Straight, Richard C.

    1989-06-01

    One of the side effects of peritoneal photodynamic treatment (PDT) of mice is a systemic suppression of contact hypersensitivity (CH) responses. Treatment with either laser alone or the photosensitizer, Photofrin II (PFII), alone does not cause suppression of CH responses. Immunosuppression of CH responses is an active process that is adoptively transferable using viable cells, but not serum, from PDT-treated mice. The induction of adoptively transferable suppressor cells in PDT-treated mice requires exposure to an antigenic stimulus, yet the suppressor cells are antigen non-specific in their function. T cell function in PDT-treated mice, as measured by the ability of splenic lymphoid cells to generate allogeneic cytotoxic T lymphocyte responses, is comparable to that detected in normal mice. However, the ability of spleen cells from PDT-treated mice to act as stimulators in a mixed lymhocyte reaction is dramatically impaired, suggesting that the major cell type affected by peritoneal PDT is of the macrophage lineage. Support for this concept is provided by experiments in which spleen cells from PDT-treated mice were chromatographically separated into populations of T cells, B cells and macrophages prior to adoptive transfer into naive recipients. The results indicate that the cell type mediating adoptively transferable suppression of CH responsiveness is of the macrophage lineage. Analysis of hematologic parameters revealed that induction of suppression by PDT-treatment was associated with a marked neutrophilia and lymphocytosis, and was also accompanied by a 5-fold increase in concentration of the acute phase protein, Serum Amyloid P. Finally, attempts to ameliorate PDT-induced immunosuppression by pharmacologic intervention have proved successful using implants of pellets that release indomethacin at a rate of 1.25µg/day. Thus, the data suggest that PDT-treatment induces macrophages to produce factors (e.g., prostaglandins) that are known to be potently

  20. Polymeric Nanoparticles for Cancer Photodynamic Therapy.

    PubMed

    Conte, Claudia; Maiolino, Sara; Pellosi, Diogo Silva; Miro, Agnese; Ungaro, Francesca; Quaglia, Fabiana

    2016-01-01

    In chemotherapy a fine balance between therapeutic and toxic effects needs to be found for each patient, adapting standard combination protocols each time. Nanotherapeutics has been introduced into clinical practice for treating tumors with the aim of improving the therapeutic outcome of conventional therapies and of alleviating their toxicity and overcoming multidrug resistance. Photodynamic therapy (PDT) is a clinically approved, minimally invasive procedure emerging in cancer treatment. It involves the administration of a photosensitizer (PS) which, under light irradiation and in the presence of molecular oxygen, produces cytotoxic species. Unfortunately, most PSs lack specificity for tumor cells and are poorly soluble in aqueous media, where they can form aggregates with low photoactivity. Nanotechnological approaches in PDT (nanoPDT) can offer a valid option to deliver PSs in the body and to solve at least some of these issues. Currently, polymeric nanoparticles (NPs) are emerging as nanoPDT system because their features (size, surface properties, and release rate) can be readily manipulated by selecting appropriate materials in a vast range of possible candidates commercially available and by synthesizing novel tailor-made materials. Delivery of PSs through NPs offers a great opportunity to overcome PDT drawbacks based on the concept that a nanocarrier can drive therapeutic concentrations of PS to the tumor cells without generating any harmful effect in non-target tissues. Furthermore, carriers for nanoPDT can surmount solubility issues and the tendency of PS to aggregate, which can severely affect photophysical, chemical, and biological properties. Finally, multimodal NPs carrying different drugs/bioactive species with complementary mechanisms of cancer cell killing and incorporating an imaging agent can be developed. In the following, we describe the principles of PDT use in cancer and the pillars of rational design of nanoPDT carriers dictated by tumor and

  1. Mechanisms of Resistance to Photodynamic Therapy

    PubMed Central

    Casas, Adriana; Di Venosa, Gabriela; Hasan, Tayyaba; Batlle, Alcira

    2013-01-01

    Photodynamic therapy (PDT) involves the administration of a photosensitizer (PS) followed by illumination with visible light, leading to generation of reactive oxygen species. The mechanisms of resistance to PDT ascribed to the PS may be shared with the general mechanisms of drug resistance, and are related to altered drug uptake and efflux rates or altered intracellular trafficking. As a second step, an increased inactivation of oxygen reactive species is also associated to PDT resistance via antioxidant detoxifying enzymes and activation of heat shock proteins. Induction of stress response genes also occurs after PDT, resulting in modulation of proliferation, cell detachment and inducing survival pathways among other multiple extracellular signalling events. In addition, an increased repair of induced damage to proteins, membranes and occasionally to DNA may happen. PDT-induced tissue hypoxia as a result of vascular damage and photochemical oxygen consumption may also contribute to the appearance of resistant cells. The structure of the PS is believed to be a key point in the development of resistance, being probably related to its particular subcellular localization. Although most of the features have already been described for chemoresistance, in many cases, no cross-resistance between PDT and chemotherapy has been reported. These findings are in line with the enhancement of PDT efficacy by combination with chemotherapy. The study of cross resistance in cells with developed resistance against a particular PS challenged against other PS is also highly complex and comprises different mechanisms. In this review we will classify the different features observed in PDT resistance, leading to a comparison with the mechanisms most commonly found in chemo resistant cells. PMID:21568910

  2. Animal models for photodynamic therapy (PDT).

    PubMed

    Silva, Zenildo Santos; Bussadori, Sandra Kalil; Fernandes, Kristianne Porta Santos; Huang, Ying-Ying; Hamblin, Michael R

    2015-01-01

    Photodynamic therapy (PDT) employs non-toxic dyes called photosensitizers (PSs), which absorb visible light to give the excited singlet state, followed by the long-lived triplet state that can undergo photochemistry. In the presence of ambient oxygen, reactive oxygen species (ROS), such as singlet oxygen and hydroxyl radicals are formed that are able to kill cancer cells, inactivate microbial pathogens and destroy unwanted tissue. Although there are already several clinically approved PSs for various disease indications, many studies around the world are using animal models to investigate the further utility of PDT. The present review will cover the main groups of animal models that have been described in the literature. Cancer comprises the single biggest group of models including syngeneic mouse/rat tumours that can either be subcutaneous or orthotopic and allow the study of anti-tumour immune response; human tumours that need to be implanted in immunosuppressed hosts; carcinogen-induced tumours; and mice that have been genetically engineered to develop cancer (often by pathways similar to those in patients). Infections are the second biggest class of animal models and the anatomical sites include wounds, burns, oral cavity, ears, eyes, nose etc. Responsible pathogens can include Gram-positive and Gram-negative bacteria, fungi, viruses and parasites. A smaller and diverse group of miscellaneous animal models have been reported that allow PDT to be tested in ophthalmology, atherosclerosis, atrial fibrillation, dermatology and wound healing. Successful studies using animal models of PDT are blazing the trail for tomorrow's clinical approvals. PMID:26415497

  3. Photodynamic therapy for the treatment of non-small cell lung cancer.

    PubMed

    Simone, Charles B; Friedberg, Joseph S; Glatstein, Eli; Stevenson, James P; Sterman, Daniel H; Hahn, Stephen M; Cengel, Keith A

    2012-02-01

    Photodynamic therapy is increasingly being utilized to treat thoracic malignancies. For patients with early-stage non-small cell lung cancer, photodynamic therapy is primarily employed as an endobronchial therapy to definitely treat endobronchial, roentgenographically occult, or synchronous primary carcinomas. As definitive monotherapy, photodynamic therapy is most effective in treating bronchoscopically visible lung cancers ≤1 cm with no extracartilaginous invasion. For patients with advanced-stage non-small cell lung cancer, photodynamic therapy can be used to palliate obstructing endobronchial lesions, as a component of definitive multi-modality therapy, or to increase operability or reduce the extent of operation required. A review of the available medical literature detailing all published studies utilizing photodynamic therapy to treat at least 10 patients with non-small cell lung cancer is performed, and treatment recommendations and summaries for photodynamic therapy applications are described.

  4. A study of the photodynamic effect on cancerous cells A study of the photodynamic effect on cancerous cells

    NASA Astrophysics Data System (ADS)

    AlSalhi, M. S.; Atif, M.; Alobiadi, A. A.; Aldwayyan, A. S.

    2012-08-01

    We use a rate equation model for the loss of the photosensitizer resulting from photo-oxidation (singlet oxygen attack on the photodynamic therapy (PDT) photosensitizer). It also incorporates the effect of photobleaching (photosensitizer decay) on the oxygen and the photosensitizer concentration which play an important role in photodynamic damage in different cell cultures. As a part of this study, we calculated photodynamic damage against the exposure time. Secondly photodynamic damage in different treated malignant/neoplastic as well as normal cell lines (Hep-2, A-549, and WI-38) has been investigated using a continuous wave (CW) He-Ne laser (633 nm of red wavelength). For determination of effectiveness of photodynamic damage two sorts of experiments are conducted. In first step of this experiment, given cell lines were photosensitized/treated with 1 ml of δ-aminolevulinic acid (ALA) having working solution of 200 μg/ml and after 4 hours of time of incubation ALA treated cells were exposed/irradiated with different doses (15 - 60 J/cm2) with constant irradiation time (15 minutes approximately). Same technique with exception of different concentration of ALA (60 - 800 μg/ml) and light dose (15 - 60 J/cm2/5-20 mW of power along with time of irradiation 15 minutes approximately) has been applied in second step of experiment. Finally result has been verified by using staining of mitochondria technique. 633 nm He-Ne (CW) along with 400 μg/ml of 5-ALA stipulates excellent therapeutic results verified by using mitochondrial staining technique as well as cell hemocytometry. Both the experimental as well as theoretical results are in good agreement with each other.

  5. Therapeutic and Aesthetic Uses of Photodynamic Therapy Part three of a five-part series

    PubMed Central

    2008-01-01

    The use of aminolevulinic acid photodynamic therapy and methyl ester of aminolevulinic acid photodynamic therapy has become commonplace in dermatology for the treatment of actinic keratoses, among other clinical entities. An intriguing question that has arisen is whether we can utilize these medicines for a chemopreventive effect; that is, preventing or delaying the onset of actinic keratoses and perhaps nonmelanoma skin cancers. This manuscript reviews the current literature and anecdotal evidence that suggests that aminolevulinic acid photodynamic therapy and methyl ester of aminolevulinic acid photodynamic therapy may indeed be chemopreventive and thus useful in preventing and/or delaying these lesions. PMID:21212845

  6. Enhancement of selectivity for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Bedwell, Joanne

    Photodynamic Therapy (PDT) is a technique for producing localised tissue damage with low power light following prior administration of a photosensitising drug. The promise of PDT has been based on the selective retention of photosensitisers by tumours, but this aspect has been over-emphasised with a maximum ratio of photosensitiser concentration of 3:1, tumour to normal, for extracranial tumours and current drugs. This makes selective tumour necrosis difficult to achieve. This thesis explores ways in which selectivity may be improved. Aluminium sulphonated phthalocyanine (AlSPc) has better photochemical properties than the widely used HpD and Photofrin II, but has the same tumour selectivity, although the ratio was improved marginally using its disulphonated component. However, when used in conjunction with the radioprotective drug W7, in a rat colon cancer model, tumour necrosis was the same as without W7 while there was no damage to adjacent normal colon. A radical new approach is to give 5-aminolaevulinic acid (ALA) which induces endogenous production of the photosensitiser protoporphyrin IX. This improves selectivity in the rat colon cancer to 6:1 (tumour to normal mucosa), but also sensitises the mucosa selectively compared with the underlying muscle (10:1), giving a tumour to muscle ratio of 60:1. This has enormous potential for treating small tumours or areas of dysplasia in a range of hollow organs. ALA also has the major advantages of a short optimum drug to light time (typically 4-6 hours), short duration of skin sensitivity (approximately 24 hours) and it can be given orally with minimal systemic toxicity. This work has also shown in vitro that PDT with AlSPc sensitisation can kill helicohacter pylori at doses unlikely to affect gastric mucosa. In conclusion, by careful choice of photosensitising agents and treatment regimes, it is possible to limit PDT effects to abnormal tissues, and even if there is some normal tissue damage, in most cases, this heals

  7. Fractionated PDT with 5-aminolevulinic acid: effective, cost effective, and patient friendly

    NASA Astrophysics Data System (ADS)

    de Vijlder, Hannah C.; Middelburg, Tom A.; de Bruijn, Henriette S.; Robinson, Dominic J.; Neumann, H. A. Martino; de Haas, Ellen R. M.

    2009-06-01

    PDT with ALA and MAL is established as a relatively effective treatment for non-melanoma skin cancer and premalignancies. PDT is often repeated, because a single treatment gives poor long term results. Preclinical studies showed that ALA-PDT applying a fractionated illumination scheme with a small first light fraction and a second larger light fraction separated by a dark interval of two hours resulted in a significant increase in efficacy. Whereas the efficacy was not enhanced by fractionating MAL-PDT, indicating that ALA-PDT mechanism is not the same as MAL-PDT mechanism. The increase in efficacy using fractionated PDT was confirmed clinically. A randomized comparative clinical study comparing fractionated ALA-PDT versus non-fractionated ALA-PDT in the treatment of superficial basal cell carcinoma showed a significant higher response rate in the lesions treated with fractionated ALA-PDT after a follow-up of one year ( p<0.002, log-rank test). The five year follow-up is studied at moment. So far the complete response in the group treated with fractionated ALA-PDT seems to be only a few percentages lower compared to the one year follow-up. Besides the gain in response rate, fractionated ALA PDT is cost effective. ALA gel is less expensive than the commercially available MAL (Metvix) and moreover fractionated ALA-PDT takes one treatment day, instead of two treatment days using the Metvix treatment protocol (two MAL-PDT treatments separated by one week), both reducing direct and indirect costs and the burden to the patient.

  8. Photodynamic therapy for chest wall recurrence from breast cancer.

    PubMed

    Allison, R R; Sibata, C; Mang, T S; Bagnato, V S; Downie, G H; Hu, X H; Cuenca, R

    2004-09-01

    Breast cancer is common with over 230,000 new cases diagnosed each year in North America alone. While great strides have been made to achieve excellent cancer control and survival, a significant minority of patients fail locally. While initial salvage to regain disease control is of the utmost importance, it is not universally successful. This leads to a therapeutic quagmire. Additional surgery, radiation and chemo-hormonal therapy are possible, but they are usually highly morbid with low success rates. Photodynamic therapy appears to be an underutilized salvage modality for this unfortunate patient population. This report analyzes and reviews the role of photodynamic therapy for patients with chest wall re-recurrence from breast cancer.

  9. Photodynamic therapy for implanted VX2 tumor in rabbit brains

    NASA Astrophysics Data System (ADS)

    Li, Fei; Feng, Hua; Lin, Jiangkai; Zhu, Gang; Chen, Zhi; Li, Cong-yan

    2005-07-01

    To evaluate the therapeutic effect and the safety of single photodynamic therapy (PDT) with hematoporphyrin derivative produced in China, 60 New Zealand adult rabbits with VX2 tumor implanted into the brain were divided randomly into non-PDT-group and PDT-group. 36 rabbits of the PDT-group were performed photodynamic therapy. The survival time, neurological deteriorations, intracranial pressure (ICP), histology, pathology, tumor volume and brain water content were measured. Other 12 rabbits were received hematoporphyrin derivative and light irradiation of the normal brain. The ICP, histology, pathology, and brain water content were measured. The result indicated that Simple PDT may elongate the average survival time of the rabbits with VX2 tumors significantly; kill tumor cells; cause transient brain edema and increase ICP, but it is safe to be used in treating brain tumor.

  10. Photoswitching of Salicylidene Methylamine: A Theoretical Photodynamics Study

    PubMed Central

    2014-01-01

    Photoswitching of simple photochromic molecules attracts substantial attention because of its possible role in future photon-driven molecular electronics. Here we model the full photoswitching cycle of a minimal photochromic Schiff base–salicylidene methylamine (SMA). We perform semiempirical nonadiabatic on-the-fly photodynamics simulations at the OM2/MRCI level and thoroughly analyze the structural time evolution and switching efficiency of the system. We also identify and examine in detail the crucial steps in the SMA photochemistry ruled by excited-state intramolecular proton transfer. The results place the investigated model aromatic Schiff base among the promising candidates for novel photoswitching molecular materials. Our study also shows the potential of the semiempirical multireference photodynamics simulations as a tool for early stage molecular photodevice design. PMID:25341075

  11. Anticancer photodynamic therapy based on the use of a microsystem

    NASA Astrophysics Data System (ADS)

    Jastrzebska, E.; Bulka, N.; Zukowski, K.; Chudy, M.; Brzozka, Z.; Dybko, A.

    2015-07-01

    The paper presents the evaluation of photodynamic therapy (PDT) procedures with an application of a microsystem. Two cell lines were used in the experiments, i.e. human lung carcinoma - A549 and normal human fetal lung fibroblast MRC5. Mono-, coculture and mixed cultures were performed in a microsystem at the same time. The microsystem consisted of a concentration gradient generator (CGG) which generates different concentrations of a photosensitizer, and a set of microchambers for cells. The microchambers were linked by microchannels of various length in order to allow cells migration and in this way cocultures were created. Transparent materials were used for the chip manufacture, i.e. glass and poly(dimethylsiloxane). A high power LED was used to test photodynamic therapy effectiveness in the microsystem.

  12. First experience of application of photodynamic therapy in keratoplasty

    NASA Astrophysics Data System (ADS)

    Fyodorov, Svyatoslav N.; Kopayeva, V. G.; Andreev, Yu. V.; Stranadko, Eugeny P.; Ponomariov, G. V.

    1996-12-01

    Vascular effect of photodynamic therapy has been studied in patients with corneal neovascularized transplant in 10 cases. THe injection of photoheme intravenously were made with subsequent irradiation by light of argon-pumped dye laser with light density of 150-300 mW/cm2 for 10-15 minutes. Energy density consisted 150-300 J/cm2. In all the cases at the time of irradiation the aggregated blood flow was appeared followed by blood flow stasis. In post- operative period the vessels disintegrated into separate fragments which disappeared completely after 10-15 days. Taking into account the data of light microscope, the disappearance of the vessels took place as a result of the vascular endothelium lysis along the vascular walls. The vessel alteration study presented in this paper, may also serve to specify the mechanism of photodynamic destruction of neovascularized stroma of tumor.

  13. Does stacking restrain the photodynamics of individual nucleobases?

    PubMed

    Nachtigallová, Dana; Zelený, Tomás; Ruckenbauer, Matthias; Müller, Thomas; Barbatti, Mario; Hobza, Pavel; Lischka, Hans

    2010-06-23

    Nonadiabatic photodynamical simulations of 4-aminopyrimidine (4-APy) used as a model for adenine were performed by embedding it between two stacking methyl-guanine (mGua) molecules to determine the effect of spatial restrictions on the ultrafast photodeactivation mechanism of this nucleobase. A hybrid multiconfigurational ab initio/molecular mechanical approach in combination with surface hopping was used. During the dynamics the formation of a significant fraction of intrastrand hydrogen bonding from 4-APy to mGua above and below is observed. These findings show that this type of hydrogen bond may play an important role for the photodynamics within one DNA strand and that it should be of interest even in irregular segments of double stranded nucleic acids structures. The relaxation mechanism of internal conversion to the ground state is dominated by ring puckering, and an overall elongation of the lifetime of the embedded system by approximately 20% as compared to the isolated 4-APy is computed. PMID:20513159

  14. Immune Response Following Photodynamic Therapy For Bladder Cancer

    NASA Astrophysics Data System (ADS)

    Raymond K.

    1989-06-01

    This study was undertaken to determine if photodynamic therapy (PDT) produces an immunologic response in patients treated for bladder cancer. Gamma interferon, interleukin 1-beta, interleukin 2 and tumor necrosis factor-alpha were assayed in the urine of four patients treated with photodynamic therapy for bladder cancer, in seven patients undergoing transurethral procedures, and in five healthy control subjects. Quantifiable concentrations of all cytokines, except gamma interferon, were measured in urine samples from the PDT patients treated with the highest light energies, while no urinary cytokines were found in the PDT patient who received the lowest light energy or in the control subjects. These findings suggest that a local immunologic response may occur following PDT for bladder cancer. Such an immunologic response activated by PDT may be an additional mechanism involved in bladder tumor destruction.

  15. Targeted photodynamic therapy--a promising strategy of tumor treatment.

    PubMed

    Bugaj, Andrzej M

    2011-07-01

    Targeted therapy is a new promising therapeutic strategy, created to overcome growing problems of contemporary medicine, such as drug toxicity and drug resistance. An emerging modality of this approach is targeted photodynamic therapy (TPDT) with the main aim of improving delivery of photosensitizer to cancer tissue and at the same time enhancing specificity and efficiency of PDT. Depending on the mechanism of targeting, we can divide the strategies of TPDT into "passive", "active" and "activatable", where in the latter case the photosensitizer is activated only in the target tissue. In this review, contemporary strategies of TPDT are described, including new innovative concepts, such as targeting assisted by peptides and aptamers, multifunctional nanoplatforms with navigation by magnetic field or "photodynamic molecular beacons" activatable by enzymes and nucleic acid. The imperative of introducing a new paradigm of PDT, focused on the concepts of heterogeneity and dynamic state of tumor, is also called for. PMID:21547329

  16. Latex carrier for improving protoporphyrin IX for photodynamic therapy.

    PubMed

    Bui, Brian; Liu, Li; Chen, Wei

    2016-06-01

    Attachment of Protoporphyrin IX (PPIX) to poly (styrene-co-4-vinylpyridine) (PS4VP) nanobeads was carried out to improve its properties in aqueous solutions. After using an oil-in-water heated emulsion polymerization technique to synthesize PS4VP, PPIX was bonded to the particles via the carboxylic acid of PPIX hydrogen-bonding to the nitrogen at the surface of PS4VP, thereby preventing self-reactions between the carboxyl groups and the porphyrin core. Refraining the two parts from interacting while attached to the nanobeads prevented PPIX from aggregating, which then increased water solubility, enhanced luminescence and singlet oxygen production. Attachment also improved cell uptake and cell destruction by photodynamic activity. This shows that PS4VP-PPIX may help improve aspects of photodynamic therapy for the treatment of cancer. PMID:27020668

  17. A Photosensitizer-Loaded DNA Origami Nanosystem for Photodynamic Therapy.

    PubMed

    Zhuang, Xiaoxi; Ma, Xiaowei; Xue, Xiangdong; Jiang, Qiao; Song, Linlin; Dai, Luru; Zhang, Chunqiu; Jin, Shubin; Yang, Keni; Ding, Baoquan; Wang, Paul C; Liang, Xing-Jie

    2016-03-22

    Photodynamic therapy (PDT) offers an alternative for cancer treatment by using ultraviolet or visible light in the presence of a photosensitizer and molecular oxygen, which can produce highly reactive oxygen species that ultimately leading to the ablation of tumor cells by multifactorial mechanisms. However, this technique is limited by the penetration depth of incident light, the hypoxic environment of solid tumors, and the vulnerability of photobleaching reduces the efficiency of many imaging agents. In this work, we reported a cellular level dual-functional imaging and PDT nanosystem BMEPC-loaded DNA origami for photodynamic therapy with high efficiency and stable photoreactive property. The carbazole derivative BMEPC is a one- and two-photon imaging agent and photosensitizer with large two-photon absorption cross section, which can be fully excited by near-infrared light, and is also capable of destroying targets under anaerobic condition by generating reactive intermediates of Type I photodynamic reactions. However, the application of BMEPC was restricted by its poor solubility in aqueous environment and its aggregation caused quenching. We observed BMEPC-loaded DNA origami effectively reduced the photobleaching of BMEPC within cells. Upon binding to DNA origami, the intramolecular rotation of BMEPC became proper restricted, which intensify fluorescence emission and radicals production when being excited. After the BMEPC-loaded DNA origami are taken up by tumor cells, upon irradiation, BMEPC could generate free radicals and be released due to DNA photocleavage as well as the following partially degradation. Apoptosis was then induced by the generation of free radicals. This functional nanosystem provides an insight into the design of photosensitizer-loaded DNA origami for effective intracellular imaging and photodynamic therapy.

  18. Simultaneous two-photon excitation of photodynamic therapy agents

    SciTech Connect

    Wachter, E.A.; Fisher, W.G. |; Partridge, W.P.; Dees, H.C.; Petersen, M.G.

    1998-01-01

    The spectroscopic and photochemical properties of several photosensitive compounds are compared using conventional single-photon excitation (SPE) and simultaneous two-photon excitation (TPE). TPE is achieved using a mode-locked titanium:sapphire laser, the near infrared output of which allows direct promotion of non-resonant TPE. Excitation spectra and excited state properties of both type 1 and type 2 photodynamic therapy (PDT) agents are examined.

  19. Photodynamic therapy as adjunctive therapy for morpheaform basal cell carcinoma.

    PubMed

    Torres, T; Fernandes, I; Costa, V; Selores, M

    2011-01-01

    The authors decided to evaluate the possible use of methyl-aminolevulinate photodynamic therapy (MAL-PDT) as adjunctive therapy for morpheaform basal cell carcinoma prior to standard surgical excision in order to reduce tumor size and volume and to facilitate surgical treatment. It was observed that MAL-PDT may be an option as an adjunctive therapy prior to standard surgical excision of morpheaform basal cell carcinoma, leading to less invasive surgery.

  20. Photodynamic action on some pathogenic microorganisms of oral cavity

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, Ilya S.; Tuchin, Valery V.

    2001-10-01

    The work is devoted to an analysis of pre-clinical and clinical experiments on photodynamic action of HeNe laser radiation in aggregate with a cation thiazinium dye Methylene Blue (MB) on a mix of pathogenic and conditionally pathogenic aerobic bacteria being activators of pyoinflammatory diseases of oral cavity. Concentration of photosensitizes at which there is no own bactericidal influence on dying microflora, and parameters of influence at which the efficiency of irradiated microflora defeat reaches 99 % are determined.

  1. Glycan-Targeted Virus-like Nanoparticles for Photodynamic Therapy

    PubMed Central

    Rhee, Jin-Kyu; Baksh, Michael; Nycholat, Corwin; Paulson, James C.; Kitagishi, Hiroaki; Finn, M.G.

    2012-01-01

    Virus-like particles (VLPs) have proven to be versatile platforms for chemical and functionalization for a variety of purposes in biomedicine, catalysis, and materials science. We here the simultaneous modification of the bacteriophage Qβ VLP with a metalloporphyrin derivative photodynamic therapy and a glycan ligand for specific targeting of cells bearing the CD-22 receptor. This application benefits from the presence of the targeting function and the delivery of a high local concentration of singlet oxygen-generating payload. PMID:22827531

  2. Photodynamic therapy in the treatment of basal cell carcinoma

    PubMed Central

    Matei, C; Tampa, M; Poteca, T; Panea-Paunica, G; Georgescu, SR; Ion, RM; Popescu, SM; Giurcaneanu, C

    2013-01-01

    Photodynamic therapy (PDT) is a medical procedure based on the activation of the molecules of various exogenous or endogenous chemical substances called photosensitizers by a light source emitting radiation of an adequate wavelength, usually situated in the visible spectrum; photosensitizers are chemical compounds bearing the capacity to selectively concentrate in the neoplastic cells. The energy captured by the molecules of these substances pervaded in the tumor cells is subsequently discharged in the surrounding tissue, triggering certain photodynamic reactions that result in the destruction of the tumor. The procedure is applicable in numerous medical fields. Skin basal cell carcinoma (BCC), the most frequent type of cancer of the human species, is a cutaneous tumor that responds very well to this innovative treatment method. By reviewing numerous recent studies in the field, this article aims to present the role and the indications of photodynamic therapy in the management of basal cell carcinoma, as well as the most important results achieved so far by this therapy in the field of dermato-oncology. PMID:23599819

  3. Effects of telomerase expression on photodynamic therapy of Barrett's esophagus

    NASA Astrophysics Data System (ADS)

    Wang, Kenneth K.; Anderson, Marlys; Buttar, Navtej; WongKeeSong, Louis-Michel; Borkenhagen, Lynn; Lutzke, Lori

    2003-06-01

    Photodynamic therapy has been applied to Barrett's esophagus and has been shown in prospective randomized studies to eliminate dysplasia as well as decrease the occurrence of cancer. However, the therapy isnot always effective and there are issues with residual areas of Barrett's mucosa despite therapy. There has not been a good explanation for these residual areas and they seem to imply that there may exist a biological mechanisms by which these cells may be resistant to photodynamic therapy. It was our aim to determine if known abnormalities in Barrett's mucosa could be correlated with the lack of response of some of these tissues. We examined the tissue from mulitpel patients who had resonse to therapy as well as those who did not respond. We assessed the tissue for p53 mutations, inactivatino of p16, ploidy status, cell proliferation, telomerase activity, and degree of dysplasia. Interestingly, the only genetic marker than was found to be correlated with lack of reonse was p53 and telomerase activity. This suggests that cells that have lost mechanisms for cell death such as apoptosis or telomere shortengin may be more resistant to photodynamic therapy. In this study, we examined patients before and after PDT for telomerase activity.

  4. Nanotechnology-Based Photodynamic Therapy: Concepts, Advances, and Perspectives.

    PubMed

    Garg, Tarun; Jain, Nitin K; Rath, Goutam; Goyal, Amit Kumar

    2015-01-01

    Photodynamic therapy (PDT) is a photoactive process that uses the combination of photosensitizers (PSs) and specific wavelengths of light for the treatment of solid tumors and other diseases. PDT received increased attention after regulatory approval of several photosensitizing drugs and light applicators worldwide. With the advent of newer PSs, the role of PDT in the treatment of cancer and other diseases has been revolutionized. In addition, various targeting strategies developed for site-specific delivery of PSs will be helpful for avoiding phototoxicity to normal tissues. Receptor-mediated targeted PDT approaches using nanocarriers offer the opportunity of enhancing photodynamic efficiency by directly targeting diseased cells and tissues. At present, clinical application of PDT is well established in medicine and surgery. Successfully used in dermatology, urology, gastroenterology, and neurosurgery, PDT has also seen much progress in basic sciences and clinical photodynamics in recent years. Currently, the use of PDT is just beginning, and more research must be performed to prove its therapeutic efficacy. However, nontoxic compounds involved in PDT provide a certain hope that it will evolve to be an effective mechanism for combating chronic diseases. PMID:26559433

  5. Photodynamic therapy for the treatment of buccal candidiasis in rats.

    PubMed

    Junqueira, Juliana Campos; Martins, Joyce da Silva; Faria, Raquel Lourdes; Colombo, Carlos Eduardo Dias; Jorge, Antonio Olavo Cardoso

    2009-11-01

    The study objective was to evaluate the effects of photodynamic therapy on buccal candidiasis in rats. After experimental candidiasis had been induced on the tongue dorsum, 72 rats were distributed into four groups according to treatment: treated with laser and methylene blue photosensitizer (L+P+); treated only with laser (L+P-); treated only with photosensitizer (L--P+); not treated with laser or photosensitizer (L-P-). The rats were killed immediately, 1 day, or 5 days after treatment, for microscopic analysis of the tongue dorsum. Observation verified that the photodynamic therapy group (L+P+) exhibited fewer epithelial alterations and a lower chronic inflammatory response than the L-P- group. The group L+P- presented more intense epithelial alterations and chronic inflammatory response than the remaining groups. The L-P+ group showed tissue lesions similar to those of the L-P- group. In conclusion, rats treated with photodynamic therapy developed more discrete candidiasis lesions than did the remaining groups.

  6. Localized electric field of plasmonic nanoplatform enhanced photodynamic tumor therapy.

    PubMed

    Li, Yiye; Wen, Tao; Zhao, Ruifang; Liu, Xixi; Ji, Tianjiao; Wang, Hai; Shi, Xiaowei; Shi, Jian; Wei, Jingyan; Zhao, Yuliang; Wu, Xiaochun; Nie, Guangjun

    2014-11-25

    Near-infrared plasmonic nanoparticles demonstrate great potential in disease theranostic applications. Herein a nanoplatform, composed of mesoporous silica-coated gold nanorods (AuNRs), is tailor-designed to optimize the photodynamic therapy (PDT) for tumor based on the plasmonic effect. The surface plasmon resonance of AuNRs was fine-tuned to overlap with the exciton absorption of indocyanine green (ICG), a near-infrared photodynamic dye with poor photostability and low quantum yield. Such overlap greatly increases the singlet oxygen yield of incorporated ICG by maximizing the local field enhancement, and protecting the ICG molecules against photodegradation by virtue of the high absorption cross section of the AuNRs. The silica shell strongly increased ICG payload with the additional benefit of enhancing ICG photostability by facilitating the formation of ICG aggregates. As-fabricated AuNR@SiO2-ICG nanoplatform enables trimodal imaging, near-infrared fluorescence from ICG, and two-photon luminescence/photoacoustic tomography from the AuNRs. The integrated strategy significantly improved photodynamic destruction of breast tumor cells and inhibited the growth of orthotopic breast tumors in mice, with mild laser irradiation, through a synergistic effect of PDT and photothermal therapy. Our study highlights the effect of local field enhancement in PDT and demonstrates the importance of systematic design of nanoplatform to greatly enhancing the antitumor efficacy. PMID:25375193

  7. Protoporphyrin IX fluorescence for enhanced photodynamic diagnosis and photodynamic therapy in murine models of skin and breast cancer

    NASA Astrophysics Data System (ADS)

    Rollakanti, Kishore Reddy

    Protoporphyrin IX (PpIX) is a photosensitizing agent derived from aminolevulinic acid. PpIX accumulates specifically within target cancer cells, where it fluoresces and produces cytotoxic reactive oxygen species. Our aims were to employ PpIX fluorescence to detect squamous cell carcinoma (SCC) of the skin (Photodynamic diagnosis, PDD), and to improve treatment efficacy (Photodynamic therapy, PDT) for basal cell carcinoma (BCC) and cutaneous breast cancer. Hyperspectral imaging and a spectrometer based dosimeter system were used to detect very early SCC in UVB-irradiated murine skin, using PpIX fluorescence. Regarding PDT, we showed that low non-toxic doses of vitamin D, given before ALA application, increase tumor specific PpIX accumulation and sensitize BCC and breast cancer cells to ALA-PDT. These optical imaging methods and the combination therapy regimen (vitamin D and ALA-PDT) are promising tools for effective management of skin and breast cancer.

  8. Preclinical studies of photodynamic therapy of intracranial tissues

    NASA Astrophysics Data System (ADS)

    Lilge, Lothar D.; Sepers, Marja; Park, Jane; O'Carroll, Cindy; Pournazari, Poupak; Prosper, Joe; Wilson, Brian C.

    1997-05-01

    The applicability and limitations of the photodynamic threshold model were investigated for an intracranial tumor (VX2) and normal brain tissues in a rabbit model. Photodynamic threshold values for four different photosensitizers, i.e., Photofrin, 5(delta) -aminolaevulinic acid (5(delta) -ALA) induced Protoporphyrin IX (PPIX), Tin Ethyl Etiopurpurin (SnET2), and chloroaluminum phthalocyanine (AlClPc), were determined based on measured light fluence distributions, macroscopic photosensitizer concentration in various brain structures, and histologically determined extent of tissue necrosis following PDT. For Photofrin, AlClPc, and SnET2, normal brain displayed a significantly lower threshold value than VX2 tumor. For 5(delta) -ALA induced PPIX and SnET2 no or very little white matter damage, equalling to very high or infinite threshold values, was observed. Additionally, the latter two photosensitizers showed significantly lower uptake in white matter compared to other brain structures and VX2 tumor. Normal brain structures lacking a blood- brain-barrier, such as the choroid plexus and the meninges, showed high photosensitizer uptake for all photosensitizers, and, hence, are at risk when exposed to light. Results to date suggest that the photodynamic threshold values iares valid for white matter, cortex and VX2 tumor. For clinical PDT of intracranial neoplasms 5(delta) -ALA induced PPIX and SnET2 appear to be the most promising for selective tumor necrosis.However, the photosensitizer concentration in each normal brain structure and the fluence distribution throughout the treatment volume and adjacent tissues at risk must be monitored to maximize the selectivity of PDT for intracranial tumors.

  9. [The randomized study of efficiency of preoperative photodynamic].

    PubMed

    Akopov, A L; Rusanov, A A; Molodtsova, V P; Gerasin, A V; Kazakov, N V; Urtenova, M A; Chistiakov, I V

    2013-01-01

    The authors made a prospective randomized comparison of results of preoperative photodynamic therapy (PhT) with chemotherapy, preoperative chemotherapy in initial unresectable central non-small cell lung cancer in stage III. The efficiency and safety of preoperative therapy were estimated as well as the possibility of subsequent surgical treatment. The research included patients in stage IIIA and IIIB of central non-small cell lung cancer with lesions of primary bronchi and lower section of the trachea, which initially were unresectable, but potentially the patients could be operated on after preoperative treatment. The photodynamic therapy was performed using chlorine E6 and the light of wave length 662 nm. Since January 2008 till December 2011,42 patients were included in the research, 21 patients were randomized in the group for photodynamic therapy and 21--in group without PhT. These groups were compared according to their sex, age, stage of the disease and histological findings. After nonadjuvant treatment the remissions were reached in 19 (90%) patients of the group with PhT and in 16 (76%) patients without PhT and all the patients were operated on. The explorative operations were made on 3 patients out of 16 operated on in the group without PhT (19%). In the group PhT 14 pneumonectomies and 5 lobectomies were perfomed opposite 10 pneumonectomies and 3 lobectomies in group without PhT. The degree of radicalism of resection appears to be reliably higher in the group PhT (RO-89%, R1-11% as against RO-54%, R1-46% in group without PhT), p = 0.038. The preoperative endobronchial PhT conducted with chemotherapy was characterized by efficiency and safety, allowed the surgical treatment and elevated the degree of radicalism of this treatment in selected patients, initially assessed as unresectable. PMID:23808222

  10. Efficient Photodynamic Therapy on Human Retinoblastoma Cell Lines

    PubMed Central

    Walther, Jan; Schastak, Stanislas; Dukic-Stefanovic, Sladjana; Wiedemann, Peter; Neuhaus, Jochen; Claudepierre, Thomas

    2014-01-01

    Photodynamic therapy (PDT) has shown to be a promising technique to treat various forms of malignant neoplasia. The photodynamic eradication of the tumor cells is achieved by applying a photosensitizer either locally or systemically and following local activation through irradiation of the tumor mass with light of a specific wavelength after a certain time of incubation. Due to preferential accumulation of the photosensitizer in tumor cells, this procedure allows a selective inactivation of the malignant tumor while sparing the surrounding tissue to the greatest extent. These features and requirements make the PDT an attractive therapeutic option for the treatment of retinoblastoma, especially when surgical enucleation is a curative option. This extreme solution is still in use in case of tumours that are resistant to conventional chemotherapy or handled too late due to poor access to medical care in less advanced country. In this study we initially conducted in-vitro investigations of the new cationic water-soluble photo sensitizer tetrahydroporphyrin-tetratosylat (THPTS) regarding its photodynamic effect on human Rb-1 and Y79 retinoblastoma cells. We were able to show, that neither the incubation with THPTS without following illumination, nor the sole illumination showed a considerable effect on the proliferation of the retinoblastoma cells, whereas the incubation with THPTS combined with following illumination led to a maximal cytotoxic effect on the tumor cells. Moreover the phototoxicity was lower in normal primary cells from retinal pigmented epithelium demonstrating a higher phototoxic effect of THPTS in cancer cells than in this normal retinal cell type. The results at hand form an encouraging foundation for further in-vivo studies on the therapeutic potential of this promising photosensitizer for the eyeball and vision preserving as well as potentially curative therapy of retinoblastoma. PMID:24498108

  11. Efficient photodynamic therapy on human retinoblastoma cell lines.

    PubMed

    Walther, Jan; Schastak, Stanislas; Dukic-Stefanovic, Sladjana; Wiedemann, Peter; Neuhaus, Jochen; Claudepierre, Thomas

    2014-01-01

    Photodynamic therapy (PDT) has shown to be a promising technique to treat various forms of malignant neoplasia. The photodynamic eradication of the tumor cells is achieved by applying a photosensitizer either locally or systemically and following local activation through irradiation of the tumor mass with light of a specific wavelength after a certain time of incubation. Due to preferential accumulation of the photosensitizer in tumor cells, this procedure allows a selective inactivation of the malignant tumor while sparing the surrounding tissue to the greatest extent. These features and requirements make the PDT an attractive therapeutic option for the treatment of retinoblastoma, especially when surgical enucleation is a curative option. This extreme solution is still in use in case of tumours that are resistant to conventional chemotherapy or handled too late due to poor access to medical care in less advanced country. In this study we initially conducted in-vitro investigations of the new cationic water-soluble photo sensitizer tetrahydroporphyrin-tetratosylat (THPTS) regarding its photodynamic effect on human Rb-1 and Y79 retinoblastoma cells. We were able to show, that neither the incubation with THPTS without following illumination, nor the sole illumination showed a considerable effect on the proliferation of the retinoblastoma cells, whereas the incubation with THPTS combined with following illumination led to a maximal cytotoxic effect on the tumor cells. Moreover the phototoxicity was lower in normal primary cells from retinal pigmented epithelium demonstrating a higher phototoxic effect of THPTS in cancer cells than in this normal retinal cell type. The results at hand form an encouraging foundation for further in-vivo studies on the therapeutic potential of this promising photosensitizer for the eyeball and vision preserving as well as potentially curative therapy of retinoblastoma. PMID:24498108

  12. Intraoperative photodynamic therapy in laryngeal part of pharynx cancers

    NASA Astrophysics Data System (ADS)

    Loukatch, Erwin V.; Trojan, Vasily; Loukatch, Vjacheslav

    1996-12-01

    In clinic intraoperative photodynamic therapy (IPT) was done in patients with primal squamous cells cancer of the laryngeal part of the pharynx. The He-Ne laser and methylene blue as a photosensibilizator were used. Cobalt therapy in the postoperative period was done in dose 45 Gr. Patients of control groups (1-th group) with only laser and (2-th group) only methylene blue were controlled during three years with the main group. The statistics show certain differences of recidives in the main group compared to the control groups. These facts are allowing us to recommend the use of IPT as an additional method in ENT-oncology diseases treatment.

  13. Spectroscopic evaluation of photodynamic therapy of the intraperitoneal cavity

    NASA Astrophysics Data System (ADS)

    Finlay, Jarod C.; Sandell, Julia L.; Zhu, Timothy C.; Lewis, Robert; Cengel, Keith A.; Hahn, Stephen M.

    2010-02-01

    We present the results of spectroscopic measurements of diffuse reflectance and fluorescence before and after photodynamic therapy of healthy canine peritoneal cavity. Animals were treated intra-operatively after iv injection of the benzoporphyrin derivative (BPD). The small bowel was treated using a uniform light field projected by a microlens-tipped fiber. The cavity was then filled with scattering medium and the remaining organs were treated using a moving diffuser. Diffuse reflectance and fluorescence measurements were made using a multi-fiber optical probe positioned on the surface of various tissues within the cavity before and after illumination. The measured data were analyzed to quantify hemoglobin concentration and oxygenation and sensitizer concentration.

  14. Biomodulatory Approaches to Photodynamic Therapy for Solid Tumors

    PubMed Central

    Anand, Sanjay; Ortel, Bernhard J.; Pereira, Stephen P.; Hasan, Tayyaba; Maytin, Edward V.

    2012-01-01

    Photodynamic Therapy (PDT) uses a photosensitizing drug in combination with visible light to kill cancer cells. PDT has an advantage over surgery or ionizing radiation because PDT can eliminate tumors without causing fibrosis or scarring. Disadvantages include the dual need for drug and light, and a generally lower efficacy for PDT versus surgery. This minireview describes basic principles of PDT, photosensitizers available, and aspects of tumor biology that may provide further opportunities for treatment optimization. An emerging biomodulatory approach, using methotrexate or Vitamin D in combination with aminolevulinate-based PDT, is described. Finally, current clinical uses of PDT for solid malignancies are reviewed. PMID:22842096

  15. Synthesis, bioanalysis and biodistribution of photosensitizer conjugates for photodynamic therapy

    PubMed Central

    Denis, Tyler GSt; Hamblin, Michael R

    2013-01-01

    Photodynamic therapy (PDT) was discovered in 1900 by Raab, and has since emerged as a promising tool for treating diseases characterized by unwanted cells or hyperproliferating tissue (e.g., cancer or infectious disease). PDT consists of the light excitation of a photosensitizer (PS) in the presence of O2 to yield highly reactive oxygen species. In recent years, PDT has been improved by the synthesis of targeted bioconjugates between monoclonal antibodies and PS, and by investigating PS biodistribution and PD. Here, we provide a comprehensive review of major developments in PS-immunoconjugate-based PDT and the bioanalysis of these agents, with a specific emphasis on anticancer and antimicrobial PDT. PMID:23641699

  16. Photodynamic induction of a bacterial cell surface polypeptide.

    PubMed Central

    Hoober, J K

    1977-01-01

    The photodynamic action of several dyes on cells of a bacterium, tentatively identified as a species of Arthrobacter, resulted in remarkable stimulation of synthesis of a polypeptide 21,000 daltons in mass. This polypeptide resides on the cell surface and can be solubilized by sodium dodecyl sulfate without lysis of the cells. Chlorophyllin and rose bengal are effective in inducing synthesis of the polypeptide in proportion to their ability to sensitize the photooxidation of histidine. Etiolated cells of the alga Chlamydomonas reinhardtii y-1 excrete a substance into the medium that also sensitized the photoinduction of the polypeptide. Images PMID:885841

  17. Destructive fat tissue engineering using photodynamic and selective photothermal effects

    NASA Astrophysics Data System (ADS)

    Tuchin, Valery V.; Yanina, Irina Yu.; Simonenko, Georgy V.

    2009-02-01

    Destructive fat tissue engineering could be realized using the optical method, which provides reduction of regional or site-specific accumulations of subcutaneous adipose tissue on the cell level. We hypothesize that light irradiation due to photodynamic and selective photothermal effects may lead to fat cell lypolytic activity (the enhancement of lipolysis of cell triglycerides due to expression of lipase activity and cell release of free fat acids (FFAs) due to temporal cell membrane porosity), and cell delayed killing due to apoptosis caused by the induced fat cell stress and/or limited cell necrosis.

  18. Uniform irradiation of irregularly shaped cavities for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Rem, Alex I.; van Gemert, Martin J. C.; van der Meulen, Freerk W.; Gijsbers, Geert H. M.; Beek, Johan F.

    1997-03-01

    It is difficult to achieve a uniform light distribution in irregularly shaped cavities. We have conducted a study on the use of hollow `integrating' moulds for more uniform light delivery of photodynamic therapy in irregularly shaped cavities such as the oral cavity. Simple geometries such as a cubical box, a sphere, a cylinder and a `bottle-neck' geometry have been investigated experimentally and the results have been compared with computed light distributions obtained using the `radiosity method'. A high reflection coefficient of the mould and the best uniform direct irradiance possible on the inside of the mould were found to be important determinants for achieving a uniform light distribution.

  19. Photodynamic therapy with laser scanning mode of tumor irradiation

    NASA Astrophysics Data System (ADS)

    Chepurna, Oksana; Shton, Irina; Kholin, Vladimir; Voytsehovich, Valerii; Popov, Viacheslav; Pavlov, Sergii; Gamaleia, Nikolai; Wójcik, Waldemar; Zhassandykyzy, Maral

    2015-12-01

    In this study we propose a new version of photodynamic therapy performed by laser scanning. The method consists in tumor treatment by a light beam of a small cross section which incrementally moves through the chosen area with a defined delay at each point and repetitively re-scans a zone starting from the initial position. Experimental evaluation of the method in vitro on murine tumor model showed that despite the dose, applied by scanning irradiation mode, was 400 times lower, the tumor inhibition rate conceded to attained with continuous irradiation mode by only 20%.

  20. In vitro photodynamic inactivation of Sporothrix schenckii complex species.

    PubMed

    Nunes Mario, Débora Alves; Denardi, Laura Bedin; Brayer Pereira, Daniela Isabel; Santurio, Janio Morais; Alves, Sydney Hartz

    2014-10-01

    Photodynamic therapy has been applied successfully against cutaneous and subcutaneous mycoses. We applied methylene blue as a photosensitizing agent and light emitting diode (InGaAlP) against Sporothrix schenckii complex species in an in vitro assay. The viability of the conidia was determined by counting colony-forming units. Methylene blue in conjunction with laser irradiation was able to inhibit the growth of all tested samples. The in vitro inhibition of Sporothrix spp. isolates by laser light deserves in vivo experimental and clinical studies since it may be a promising treatment for cutaneous and subcutaneous sporotrichosis.

  1. 3D Monte Carlo radiation transfer modelling of photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Campbell, C. Louise; Christison, Craig; Brown, C. Tom A.; Wood, Kenneth; Valentine, Ronan M.; Moseley, Harry

    2015-06-01

    The effects of ageing and skin type on Photodynamic Therapy (PDT) for different treatment methods have been theoretically investigated. A multilayered Monte Carlo Radiation Transfer model is presented where both daylight activated PDT and conventional PDT are compared. It was found that light penetrates deeper through older skin with a lighter complexion, which translates into a deeper effective treatment depth. The effect of ageing was found to be larger for darker skin types. The investigation further strengthens the usage of daylight as a potential light source for PDT where effective treatment depths of about 2 mm can be achieved.

  2. Photodynamic therapy of port wine stain: preliminary clinical studies

    NASA Astrophysics Data System (ADS)

    Nelson, J. Stuart

    1993-07-01

    The broad, long term objective of this work is the development of Photodynamic Therapy (PDT) for application in the clinical management of patients with port wine stain (PWS). PDT involves the use of an exogenous drug which is concentrated in a targeted tissue. When irradiated at wavelengths specifically absorbed by the drug, selective destruction of the targeted tissue, without the production of heat, occurs. The results of this preliminary study demonstrate in human PWS patients that a photosensitizer, such as PHOTOFRINR, activated by red light at the appropriate therapeutic wavelength, can cause destruction of subsurface blood vessels in the skin with a high degree of specificity, and further study appears warranted.

  3. Three-dimensional illumination procedure for photodynamic therapy of dermatology

    NASA Astrophysics Data System (ADS)

    Hu, Xiao-ming; Zhang, Feng-juan; Dong, Fei; Zhou, Ya

    2014-09-01

    Light dosimetry is an important parameter that affects the efficacy of photodynamic therapy (PDT). However, the irregular morphologies of lesions complicate lesion segmentation and light irradiance adjustment. Therefore, this study developed an illumination demo system comprising a camera, a digital projector, and a computing unit to solve these problems. A three-dimensional model of a lesion was reconstructed using the developed system. Hierarchical segmentation was achieved with the superpixel algorithm. The expected light dosimetry on the targeted lesion was achieved with the proposed illumination procedure. Accurate control and optimization of light delivery can improve the efficacy of PDT.

  4. Encapsulation of methylene blue in polyacrylamide nanoparticle platforms protects its photodynamic effectiveness.

    PubMed

    Tang, Wei; Xu, Hao; Park, Edwin J; Philbert, Martin A; Kopelman, Raoul

    2008-05-01

    The ability to prevent methylene blue (MB), a photosensitizer, from being reduced by plasma reductases will greatly improve its efficacy in photodynamic therapy (PDT) applications. We have developed a delivery approach for PDT by encapsulating MB using nanoparticle platforms (NPs). The 30-nm polyacrylamide-based NPs provide protection for the embedded MB against reduction by diaphorase enzymes. Furthermore, our data shows the matrix-protected MB efficiently induces photodynamic damage to tumor cells. The unprecedented results demonstrate the significant in vitro photodynamic effectiveness of MB when encapsulated within NPs, which promises to open new opportunities for MB in its in vivo and clinical studies.

  5. Two-photon photodynamic properties of TBO-AuNR-in-shell nanoparticles (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Wu, Cheng-Han; Yeh, Chen-Sheng; Cheng, Fong-Yu; Tsai, Zen-Uong; Liu, Tzu-Ming

    2016-03-01

    Photodynamic therapy (PDT) is a light-activated chemotherapeutic treatment that utilizes singlet oxygen and reactive oxygen species induced oxidative reactions to react with surrounding biological substrates, which either kills or irreversibly damages malignant cells. We used multiphoton nonlinear optical microscopy to observe the photo-dynamic effects of TBO-AuNR-in-shell NPs. Excited by femtosecond Cr:forsterite laser operating at 1230nm, singlet oxygen were generated through a plasmon-enhanced two-photon nonlinear optical process. For cells took up NPs, this photodynamic effect can kill the cell. From nonlinear optical microscopy images, we found they shrunk after 3 minutes of illumination.

  6. Encapsulation of methylene blue in polyacrylamide nanoparticle platforms protects its photodynamic effectiveness.

    PubMed

    Tang, Wei; Xu, Hao; Park, Edwin J; Philbert, Martin A; Kopelman, Raoul

    2008-05-01

    The ability to prevent methylene blue (MB), a photosensitizer, from being reduced by plasma reductases will greatly improve its efficacy in photodynamic therapy (PDT) applications. We have developed a delivery approach for PDT by encapsulating MB using nanoparticle platforms (NPs). The 30-nm polyacrylamide-based NPs provide protection for the embedded MB against reduction by diaphorase enzymes. Furthermore, our data shows the matrix-protected MB efficiently induces photodynamic damage to tumor cells. The unprecedented results demonstrate the significant in vitro photodynamic effectiveness of MB when encapsulated within NPs, which promises to open new opportunities for MB in its in vivo and clinical studies. PMID:18298950

  7. Enhancement of tumor responsiveness to aminolevulinate-photodynamic therapy (ALA-PDT) using differentiation-promoting agents in mouse models of skin carcinoma

    NASA Astrophysics Data System (ADS)

    Anand, Sanjay; Honari, Golara; Paliwal, Akshat; Hasan, Tayyaba; Maytin, Edward V.

    2009-06-01

    Aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) is an emerging treatment for cancers. ALA, given as a prodrug, selectively accumulates and is metabolized in cancer cells to form protoporphyrin IX (PpIX). Targeted local irradiation with light induces cell death. Since the efficacy of ALA-PDT for large or deep tumors is currently limited, we are developing a new approach that combines differentiation-inducing agents with ALA-PDT to improve the clinical response. Here, we tested this new combination paradigm in the following two models of skin carcinoma in mice: 1) tumors generated by topical application of chemical carcinogens (DMBA-TPA); 2) human SCC cells (A431) implanted subcutaneously. To achieve a differentiated state of the tumors, pretreatment with a low concentration of methotrexate (MTX) or Vitamin D (Vit D) was administered for 72 h prior to exposure to ALA. Confocal images of histological sections were captured and digitally analyzed to determine relative PpIX levels. PpIX in the tumors was also monitored by real-time in vivo fluorescence dosimetry. In both models, a significant increase in levels of PpIX was observed following pretreatment with MTX or Vit D, as compared to no-pretreatment controls. This enhancing effect was observed at very low, non-cytotoxic concentrations, and was highly specific to cancer cells as compared to normal cells. These results suggest that use of differentiating agents such as MTX or Vit D, as a short-term combination therapy given prior to ALA-PDT, can increase the production of PpIX photosensitizer and enhance the therapeutic response of skin cancers.

  8. Measurement of intracellular oxygen concentration during photodynamic therapy in vitro.

    PubMed

    Weston, Mark A; Patterson, Michael S

    2014-01-01

    A technique is introduced that monitors the depletion of intracellular ground state oxygen concentration ([(3)O(2)]) during photodynamic therapy of Mat-LyLu cell monolayers and cell suspensions. The photosensitizer Pd(II) meso-tetra(4-carboxyphenyl)porphine (PdT790) is used to manipulate and indicate intracellular [(3)O(2)] in both of the in vitro models. The Stern-Volmer relationship for PdT790 phosphorescence was characterized in suspensions by flowing nitrogen over the suspension while short pulses of 405 nm light were used to excite the sensitizer. The bleaching of sensitizer and the oxygen consumption rate were also measured during continuous exposure of the cell suspension to the 405 nm laser. Photodynamic therapy (PDT) was conducted in both cell suspensions and in cell monolayers under different treatment conditions while the phosphorescence signal was acquired. The intracellular [(3)O(2)] during PDT was calculated by using the measured Stern-Volmer relationship and correcting for sensitizer photobleaching. In addition, the amount of oxygen that was consumed during the treatments was calculated. It was found that even at large oxygen consumption rates, cells remain well oxygenated during PDT of cell suspensions. For monolayer treatments, it was found that intracellular [(3)O(2)] is rapidly depleted over the course of PDT.

  9. Predicting photodynamic therapy efficacy with photoacoustic imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Mallidi, Srivalleesha; Mai, Zhiming; Khan, Amjad P.; Hasan, Tayyaba

    2016-03-01

    Photodynamic therapy (PDT) is a photochemistry based cytotoxic technique that imparts cellular damage via excitation of a photosensitizer with drug-specific wavelength of light. The dose at the treatment site for type II PDT is determined by three factors: photosensitizer (PS) concentration, oxygenation status and delivered light irradiance. Most of the FDA approved photosensitizers in their triplet-excited state generate cytotoxic species by reacting with the ground state oxygen that is available in the surrounding environment. Given the inter- and intra-subject variability in the uptake of the photosensitizer and the distribution of oxygen in the tumor, understanding the interplay between these dose parameters could aid in determining photodynamic therapy efficacy. Previously several studies have discussed the interplay between the dose parameters using shown point measurements and 2D imaging systems. Using various subcutaneous and orthotopic mouse models we will demonstrate the utility of a non-invasive non-ionizing photoacoustic imaging modality to determine efficacy and predict treatment response in Benzoporphyrin derivative (BPD) or Aminolevulinic acid (ALA) based PDT. We further compare the predictive capability of photoacoustic imaging with the more predominantly used fluorescence imaging and immunohistochemistry techniques.

  10. Hematoporphyrin derivative uptake and photodynamic therapy in pancreatic carcinoma

    SciTech Connect

    Schroder, T.; Chen, I.W.; Sperling, M.; Bell, R.H. Jr.; Brackett, K.; Joffe, S.N.

    1988-05-01

    Little information is currently available concerning the uptake of porphyrins by pancreatic tumors, or the effect of photodynamic therapy (PDT) on pancreatic cancer. In Syrian golden hamsters (n = 33), the organ distribution of /sup 125/I-labeled dihematoporphyrin ether (DHE) was studied in a pancreatic cancer model. In the same animal model the effect of PDT was studied using a gold vapor laser for energy delivery 3 hr after the injection of DHE (n = 7). DHE was 2.4 times more concentrated in the pancreatic tumor than in the nontumorous pancreas at 3 hr. Simultaneously there was a considerable accumulation of DHE in the surrounding gastrointestinal tract, causing perforation of the duodenum and jejunum with resultant death in four (57%) animals after PDT. Photodynamic therapy caused extensive tumor necrosis without any obvious effect on the nontumor-bearing pancreas. Damage to the surrounding tissue in the hamster indicates that precautions should be taken if PDT is to be used clinically in pancreatic cancer. Intratumoral injection of DHE may give higher drug concentrations with greater specificity for tumor treatment.

  11. Upconversion Nanoparticles for Photodynamic Therapy and Other Cancer Therapeutics

    PubMed Central

    Wang, Chao; Cheng, Liang; Liu, Zhuang

    2013-01-01

    Photodynamic therapy (PDT) is a non-invasive treatment modality for a variety of diseases including cancer. PDT based on upconversion nanoparticles (UCNPs) has received much attention in recent years. Under near-infrared (NIR) light excitation, UCNPs are able to emit high-energy visible light, which can activate surrounding photosensitizer (PS) molecules to produce singlet oxygen and kill cancer cells. Owing to the high tissue penetration ability of NIR light, NIR-excited UCNPs can be used to activate PS molecules in much deeper tissues compared to traditional PDT induced by visible or ultraviolet (UV) light. In addition to the application of UCNPs as an energy donor in PDT, via similar mechanisms, they could also be used for the NIR light-triggered drug release or activation of 'caged' imaging or therapeutic molecules. In this review, we will summarize the latest progresses regarding the applications of UCNPs for photodynamic therapy, NIR triggered drug and gene delivery, as well as several other UCNP-based cancer therapeutic approaches. The future prospects and challenges in this emerging field will be also discussed. PMID:23650479

  12. A combination of techniques to evaluate photodynamic efficiency of photosensitizers

    NASA Astrophysics Data System (ADS)

    Cavalcante, R. S.; Imasato, H.; Bagnato, V. S.; Perussi, J. R.

    2009-01-01

    Photodynamic therapy, used mainly for cancer treatment and microorganisms inactivation, is based on production of reactive oxygen species by light irradiation of a sensitizer. Hematoporphyrin derivatives as Photofrin® (PF), Photogem® (PG) and Photosan® (PF), and chlorin-e6-derivatives as Photodithazine® (PZ), have suitable sensitizing properties. The present study provides a way to make a fast previous evaluation of photosensitizers efficacy by a combination of techniques: a) use of bovine serum albumin and uric acid as chemical dosimeters; b) photo-hemolysis of red blood cells used as a cell membrane interaction model, and c) octanol/phosphate buffer partition to assess the relative lipophilicity of the compounds. The results suggest the photodynamic efficient ranking: PZ > PG >= PF > PS. These results agree with the cytotoxicity of the photosensitizers as well as to chromatographic separation of the HpDs, both performed in our group, showing that the more lipophilic is the dye, the more acute is the damage to the RBC membrane and the oxidation of indol, which is immersed in the hydrophobic region of albumin.

  13. Phthalocyanines And Their Sulfonated Derivatives As Photosensitizers In Photodynamic Therapy.

    NASA Astrophysics Data System (ADS)

    Riesz, Peter; Krishna, C. Murali

    1988-02-01

    Photodynamic therapy (PDT) of human tumors with hematoporphyrin derivative (HpD) has achieved encouraging results. However, HpD is a complex mixture whose composition varies in different preparations and with time of storage. The future promise of PDT for cancer treatment depends on the development of new chemically defined sensitizers which absorb more strongly than HpD in the 600-800 nm region. A shift to higher wavelengths is desirable since it allows increased light penetration in human tissues. In vivo, these sensitizers should be non-toxic, localize selectively in tumors and generate cytotoxic species upon illumination with a high quantum yield. These damaging species may be singlet oxygen (1O2) produced by the transfer of energy from the triplet state of the sensitizer to oxygen (Type II) or superoxide anion radicals formed by electron transfer to oxygen or substrate radicals generated by electron or hydrogen transfer directly from the sensitizer (Type I). The recent work of several groups indicating that phthalocyanines and their water soluble derivatives are promising candidates for PDT is reviewed. The photophysics, photochemistry, photosensitized killing of cultured mammalian cells and the use for in vivo photodynamic therapy of phthalocyanines is outlined. Our studies of the post-illumination photohemolysis of human red blood cells as a model system for membrane photomodification sensitized by phthalocyanine sulfonates are consistent with the predominant role of 1O2 as the damaging species.

  14. Photodynamic therapy for circumscribed choroidal haemangioma: a case report.

    PubMed

    Bhatt, Chirag; Bandyopadhyay, Samir Kumar; Chatterjee, P K; Paul, R C; Bagchi, S C; Chatterjee, Arkendu

    2011-10-01

    Choroidal haemangioma is a benign tumour with visual acuity diminution due to subretinal fluid accumulation. There are many modalities of treatment of this visually disabling syndrome, some of them being argon laser photocoagulation, cryotherapy, external beam irradiation, proton beam radiotherapy, episcleral plaque radiotherapy and transpupillary thermotherapy. Another new modality of treatment with remarkable success rate is photodynamic therapy. In this modality a photosensitiser is injected intravenously followed by irradiation of a specific wave length for a specified time period. The photosensitiser concentrates within the vascular channels and after irradiation these channels are irreversibly obliterated. A 62 years old female patient of choroidal haemangioma, who presented in eye outpatient department was treated with the standard protocol used for photodynamic therapy. On follow-up of this patient it was found that there was improvement in the visual acuity from 6/12 in the left eye (affected eye) to 6/9. Not only was there an improvement in the visual acuity but there was anatomical improvement too as was evident by regressed cystoid macular oedema and circumscribed choroidal haemangioma. After six months of follow-up there was no leakage of dye with digital fluorescein angiography and indocyanine green.

  15. Photodynamic therapy of human tubulo-villous adenomas

    NASA Astrophysics Data System (ADS)

    Warloe, Trond; Peng, Qian; Heyerdahl, Helen; Waehre, Hakon; Moan, Johan; Steen, Harald B.; Giercksky, Karl-Erik

    1995-01-01

    Nine selected patients with rectal tubulo-villous adenomas were treated with Photofrin- or aminolevulinic acid (ALA)-based photodynamic therapy (PDT) after the main bulk of the primary tumors had been endoscopically resected. The distribution patterns of Photofrin and ALA-induced porphyrins in the adenomas and surrounding normal tissues were studied by means of microscopic fluorescence photometry. Nine patients were treated in a total of 14 PDT sessions. Photofrin and ALA were used in 5 and 9 sessions, respectively. The tumors in all 5 Photofrin-based PDT sessions demonstrated complete regression. However, they all recurred 4 - 20 months after PDT. Four of 9 ALA-based PDT sessions achieved complete regression and so far no recurrence of these tumors has been found, although the follow-up is only 3 - 10 months. Two of the cases of partial response were given a second ALA-based PDT and both of them obtained complete response. The microscopic fluorescence photometry of the biopsies taken from the tumor and surrounding normal tissues after administration of either Photofrin or ALA showed that there was a strong fluorescence of Photofrin in the vascular stroma of the tumor and normal tissues, whereas ALA-induced porphyrins were mainly distributed in the glandular neoplastic cells. The correlation between the distribution of Photofrin and ALA-induced porphyrins in the adenomas and their photodynamic effects is discussed.

  16. Metal nanoparticles amplify photodynamic effect on skin cells in vitro

    NASA Astrophysics Data System (ADS)

    Bauer, Brigitte; Chen, Si; Käll, Mikael; Gunnarsson, Linda; Ericson, Marica B.

    2011-03-01

    We report on an investigation aimed to increase the efficiency of photodynamic therapy (PDT) through the influence of localized surface plasmon resonances (LSPR's) in metal nanoparticles. PDT is based on photosensitizers that generate singlet oxygen at the tumour site upon exposure to visible light. Although PDT is a well-established treatment for skin cancer, a major drawback is the low quantum yield for singlet-oxygen production. This motivates the development of novel methods that enhance singlet oxygen generation during treatment. In this context, we study the photodynamic effect on cultured human skin cells in the presence or absence of gold nanoparticles with well established LSPR and field-enhancement properties. The cultured skin cells were exposed to protoporphyrin IX and gold nanoparticles and subsequently illuminated with red light. We investigated the differences in cell viability by tuning different parameters, such as incubation time and light dose. In order to find optimal parameters for specific targeting of tumour cells, we compared normal human epidermal keratinocytes with a human squamous skin cancer cell line. The study indicates significantly enhanced cell death in the presence of nanoparticles and important differences in treatment efficiency between normal and tumour cells. These results are thus promising and clearly motivate further development of nanoparticle enhanced clinical PDT treatment.

  17. Targeted photodynamic therapy for infected wounds in mice

    NASA Astrophysics Data System (ADS)

    Hamblin, Michael R.; O'Donnell, David A.; Zahra, Touqir; Contag, Christopher H.; McManus, Albert T.; Hasan, Tayyaba

    2002-06-01

    Although many workers have used photodynamic therapy to kill bacteria in vitro, the use of this approach has seldom been reported in vivo in animal models of infection. We report on the use of a targeted polycationic photosensitizer conjugate between poly-L-lysine and chlorin(e6) that can penetrate the Gram (-) outer membrane together with red laser light to kill Escherichia coli and Pseudomonas aeruginosa infecting excisional wounds in mice. We used genetically engineered luminescent bacteria that allowed the infection to be imaged in mouse wounds using a sensitive CCD camera. Wounds were infected with 5x106 bacteria, followed by application of the conjugate in solution and illumination. There was a light-dose dependent loss of luminescence as measured by image analysis in the wound treated with conjugate and light, not seen in control wounds. This strain of E coli is non-invasive and the infection in untreated wounds spontaneously resolved in a few days and all wounds healed equally well showing the photodynamic treatment did not damage the host tissue. P aeruginosa is highly invasive and mice with untreated or control wounds all died while 90% of PDT treated mice survived. PDT may have a role to play in the rapid treatment of infected wounds in view of the worldwide rise in antibiotic resistance.

  18. Illumination devices for photodynamic therapy of the oral cavity.

    PubMed

    Canavesi, Cristina; Fournier, Florian; Cassarly, William J; Foster, Thomas H; Rolland, Jannick P

    2010-11-23

    Three compact and efficient designs are proposed to deliver an average irradiance of 50 mW/cm(2) with spatial uniformity well above 90% over a 25 mm(2) target area for photodynamic therapy of the oral cavity. The main goal is to produce uniform illumination on the target while limiting irradiation of healthy tissue, thus overcoming the need of shielding the whole oral cavity and greatly simplifying the treatment protocol. The first design proposed consists of a cylindrical diffusing fiber placed in a tailored reflector derived from the edge-ray theorem with dimensions 5.5 × 7.2 × 10 mm(3); the second device combines a fiber illuminator and a lightpipe with dimensions 6.8 × 6.8 × 50 mm(3); the third design, inspired by the tailored reflector, is based on a cylindrical diffusing fiber and a cylinder reflector with dimensions 5 × 10 × 11 mm(3). A prototype for the cylinder reflector was built that provided the required illumination for photodynamic therapy of the oral cavity, producing a spatial uniformity on the target above 94% and an average irradiance of 51 mW/cm(2) for an input power of 70 mW.

  19. Illumination devices for photodynamic therapy of the oral cavity

    PubMed Central

    Canavesi, Cristina; Fournier, Florian; Cassarly, William J.; Foster, Thomas H.; Rolland, Jannick P.

    2010-01-01

    Three compact and efficient designs are proposed to deliver an average irradiance of 50 mW/cm2 with spatial uniformity well above 90% over a 25 mm2 target area for photodynamic therapy of the oral cavity. The main goal is to produce uniform illumination on the target while limiting irradiation of healthy tissue, thus overcoming the need of shielding the whole oral cavity and greatly simplifying the treatment protocol. The first design proposed consists of a cylindrical diffusing fiber placed in a tailored reflector derived from the edge-ray theorem with dimensions 5.5 × 7.2 × 10 mm3; the second device combines a fiber illuminator and a lightpipe with dimensions 6.8 × 6.8 × 50 mm3; the third design, inspired by the tailored reflector, is based on a cylindrical diffusing fiber and a cylinder reflector with dimensions 5 × 10 × 11 mm3. A prototype for the cylinder reflector was built that provided the required illumination for photodynamic therapy of the oral cavity, producing a spatial uniformity on the target above 94% and an average irradiance of 51 mW/cm2 for an input power of 70 mW. PMID:21157577

  20. Photodynamic inactivation of contaminated blood with Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Corrêa, Thaila Q.; Inada, Natalia M.; Pratavieira, Sebastião.; Blanco, Kate C.; Kurachi, Cristina; Bagnato, Vanderlei S.

    2016-03-01

    The presence of bacteria in the bloodstream can trigger a serious systemic inflammation and lead to sepsis that cause septic shock and death. Studies have shown an increase in the incidence of sepsis over the years and it is mainly due to the increased resistance of microorganisms to antibiotics, since these drugs are still sold and used improperly. The bacterial contamination of blood is also a risk to blood transfusions. Thus, bacteria inactivation in blood is being studied in order to increase the security of the blood supply. The purpose of this study was to decontaminate the blood using the photodynamic inactivation (PDI). Human blood samples in the presence of Photogem® were illuminated at an intensity of 30 mW/cm2, and light doses of 10 and 15 J/cm2. Blood counts were carried out for the quantitative evaluation and blood smears were prepared for qualitative and morphological evaluation by microscopy. The results showed normal viability values for the blood cells analyzed. The light doses showed minimal morphological changes in the membrane of red blood cells, but the irradiation in the presence of the photosensitizer caused hemolysis in red blood cells at the higher concentrations of the photosensitizer. Experiments with Staphylococcus aureus, one of the responsible of sepsis, showed 7 logs10 of photodynamic inactivation with 50 μg/mL and 15 J/cm2 and 1 log10 of this microorganism in a co-culture with blood.

  1. Pulmonary decontamination for photodynamic inactivation with extracorporeal illumination

    NASA Astrophysics Data System (ADS)

    Geralde, Mariana C.; Leite, Ilaiáli S.; Inada, Natalia M.; Grecco, Clóvis; Medeiros, Alexandra I.; Kurachi, Cristina; Bagnato, Vanderlei S.

    2014-03-01

    Infectious pneumonia is a major cause of morbidity and mortality, despite advances in diagnostics and therapeutics in pulmonary infections. One of the major difficulties associated with the infection comes from the high rate of antibiotic resistant microorganisms, claiming for the use of alternative techniques with high efficiency and low cost. The photodynamic inactivation (PDI) is emerging as one of the great possibilities in this area, once its action is oxidative, not allowing microorganism develops resistance against the treatment. PDI for decontamination pulmonary has potential for treatment or creating better conditions for the action of antibiotics. In this study, we are developing a device to implement PDI for the treatment of lung diseases with extracorporeal illumination. To validate our theory, we performed measurements in liquid phantom to simulate light penetration in biological tissues at various fluency rates, the temperature was monitored in a body of hairless mice and the measurements of light transmittance in this same animal model. A diode laser emitting at 810 nm in continuous mode was used. Our results show 70% of leakage at 0.5 mm of thickness in phantom model. The mouse body temperature variation was 5.4 °C and was observed light transmittance through its chest. These results are suggesting the possible application of the extracorporeal illumination using infrared light source. Based on these findings, further studies about photodynamic inactivation will be performed in animal model using indocyanine green and bacteriochlorin as photosensitizers. The pulmonary infection will be induced with Streptococcus pneumoniae and Klebsiella pneumoniae.

  2. Photodynamic therapy: a review of applications in neurooncology and neuropathology

    NASA Astrophysics Data System (ADS)

    Uzdensky, Anatoly B.; Berezhnaya, Elena; Kovaleva, Vera; Neginskaya, Marya; Rudkovskii, Mikhail; Sharifulina, Svetlana

    2015-06-01

    Photodynamic therapy (PDT) effect is a promising adjuvant modality for diagnosis and treatment of brain cancer. It is of importance that the bright fluorescence of most photosensitizers provides visualization of brain tumors. This is successfully used for fluorescence-guided tumor resection according to the principle "to see and to treat." Non-oncologic application of PDT effect for induction of photothrombotic infarct of the brain tissue is a well-controlled and reproducible stroke model, in which a local brain lesion is produced in the predetermined brain area. Since normal neurons and glial cells may also be damaged by PDT and this can lead to unwanted neurological consequences, PDT effects on normal neurons and glial cells should be comprehensively studied. We overviewed the current literature data on the PDT effect on a range of signaling and epigenetic proteins that control various cell functions, survival, necrosis, and apoptosis. We hypothesize that using cell-specific inhibitors or activators of some signaling proteins, one can selectively protect normal neurons and glia, and simultaneously exacerbate photodynamic damage of malignant gliomas.

  3. Merocyanine-540 mediated photodynamic effects on Staphylococcus epidermidis biofilms

    NASA Astrophysics Data System (ADS)

    Sbarra, Maria Sonia; Di Poto, Antonella; Saino, Enrica; Visai, Livia; Minzioni, Paolo; Bragheri, Francesca; Cristiani, Ilaria

    2009-07-01

    Staphylococci are important causes of nosocomial and medical-device-related infections. Their virulence is attributed to the elaboration of biofilms that protect the organisms from immune system clearance and to increased resistance to phagocytosis and antibiotics. Photodynamic treatment (PDT) has been proposed as an alternative approach for the inactivation of bacteria in biofilms. In this study, we evaluated the antimicrobial activity of merocyanine 540 (MC 540), a photosensitizing dye that is used for purging malignant cells from autologous bone marrow grafts, against Staphylococcus epidermidis biofilms. We evaluated the effect of the combined photodynamic action of MC 540 and 532 nm laser on the viability and structure of biofilms of two Staphylococcus epidermidis strains. Significant inactivation of cells was observed in the biofilms treated with MC-540 and then exposed to laser radiation. Furthermore we found that the PDT effect, on both types of cells, was significantly dependent on both the light-dose and on the impinging lightintensity. Disruption of PDT-treated biofilm was confirmed by scanning electron microscopy (SEM).

  4. Photodynamic evaluation of tetracarboxy-phthalocyanines in model systems.

    PubMed

    Alonso, Lais; Sampaio, Renato N; Souza, Thalita F M; Silva, Rodrigo C; Neto, Newton M Barbosa; Ribeiro, Anderson O; Alonso, Antonio; Gonçalves, Pablo J

    2016-08-01

    The present work reports the synthesis, photophysical and photochemical characterization and photodynamic evaluation of zinc, aluminum and metal free-base tetracarboxy-phthalocyanines (ZnPc, AlPc and FbPc, respectively). To evaluate the possible application of phthalocyanines as a potential photosensitizer the photophysical and photochemical characterization were performed using aqueous (phosphate-buffered solution, PBS) and organic (dimethyl sulfoxide, DMSO) solvents. The relative lipophilicity of the compounds was estimated by the octanol-water partition coefficient and the photodynamic activity evaluated through the photooxidation of a protein and photohemolysis. The photooxidation rate constants (k) were obtained and the hemolytic potential was evaluated by the maximum percentage of hemolysis achieved (Hmax) and the time (t50) to reach 50% of the Hmax. Although these phthalocyanines are all hydrophilic and possess very low affinity for membranes (log PO/W=-2.0), they led to significant photooxidation of bovine serum albumin (BSA) and photohemolysis. Our results show that ZnPc was the most efficient photosensitizer, followed by AlPc and FbPc; this order is the same as the order of the triplet and singlet oxygen quantum yields (ZnPc>AlPc>FbPc). Furthermore, together, the triplet, fluorescence and singlet oxygen quantum yields of zinc tetracarboxy-phthalocyanines suggest their potential for use in theranostic applications, which simultaneously combines photodiagnosis and phototherapy.

  5. Photosensitizer nanocarriers modeling for photodynamic therapy applied to dermatological diseases

    NASA Astrophysics Data System (ADS)

    Salas-García, I.; Fanjul-Vélez, F.; Ortega-Quijano, N.; López-Escobar, M.; Arce-Diego, J. L.

    2011-02-01

    Photodynamic Therapy involves the therapeutic use of photosensitizers in combination with visible light. The subsequent photochemical reactions generate reactive oxygen species which are considered the principal cytotoxic agents to induce cell death. This technique has become widely used in medicine to treat tumors and other nonmalignant diseases. However, there are several factors related to illumination or the photosensitizer that limit an optimal treatment outcome. The use of nanoparticles (NP) for PDT has been proposed as a solution to current shortcomings. In this way, there are NPs that act as carriers for photosensitizers, NPs that absorb the light and transfer the energy to the photosensitizer and NPs that are themselves photodynamically active. In dermatology, the use of topical photosensitizers produces a time dependent inhomogeneous distribution within the tumor, where the stratum corneum is the main barrier to the diffusion of the photosensitizer to the deeper layers of skin. This produces an insufficient photosensitizer accumulation in tumor tissues and therefore, a low therapeutic efficiency in the case of deep lesions. This work focuses in the use of NPs as photosensitizer carriers to improve the actual topical drug distribution in malignant skin tissues. We present a mathematical model of PS distribution in tumor tissue using NPs that takes into account parameters related to nanoparticles binding. Once the concentration profile of NPs into tissue is obtained, we use a photochemical model which allows us to calculate the temporal evolution of reactive oxygen species according to PS distribution calculated previously from NPs profile.

  6. Photodynamic research at Baylor University Medical Center Dallas, Texas

    NASA Astrophysics Data System (ADS)

    Gulliya, Kirpal S.; Matthews, James Lester; Sogandares-Bernal, Franklin M.; Aronoff, Billie L.; Judy, Millard M.

    1993-03-01

    We received our first CO2 laser at Baylor University Medical Center in December 1974, following a trip to Israel in January of that year. Discussion with the customs office of the propriety of charging an 18% import tax lasted for nine months. We lost that argument. Baylor has been using lasers of many types for many procedures since that time. About ten years ago, through the kindness of Tom Dougherty and Roswell Park, we started working with photodynamic therapy, first with hematoporphyrin I and later with dihematoporphyrin ether (II). In February 1984, we were invited to a conference at Los Alamos, New Mexico, U.S.A. on medical applications of the free electron laser as part of the Star Wars Program. A grant application from Baylor was approved that November, but funding did not start for many months. This funding contributed to the development of a new research center as part of Baylor Research Institute. Many of the projects investigated at Baylor dealt with applications of the free electron laser (FEL), after it became available. A staff was assembled and many projects are still ongoing. I would like to outline those which are in some way related to photodynamic therapy.

  7. Upconversion nanoparticles for photodynamic therapy and other cancer therapeutics.

    PubMed

    Wang, Chao; Cheng, Liang; Liu, Zhuang

    2013-01-01

    Photodynamic therapy (PDT) is a non-invasive treatment modality for a variety of diseases including cancer. PDT based on upconversion nanoparticles (UCNPs) has received much attention in recent years. Under near-infrared (NIR) light excitation, UCNPs are able to emit high-energy visible light, which can activate surrounding photosensitizer (PS) molecules to produce singlet oxygen and kill cancer cells. Owing to the high tissue penetration ability of NIR light, NIR-excited UCNPs can be used to activate PS molecules in much deeper tissues compared to traditional PDT induced by visible or ultraviolet (UV) light. In addition to the application of UCNPs as an energy donor in PDT, via similar mechanisms, they could also be used for the NIR light-triggered drug release or activation of 'caged' imaging or therapeutic molecules. In this review, we will summarize the latest progresses regarding the applications of UCNPs for photodynamic therapy, NIR triggered drug and gene delivery, as well as several other UCNP-based cancer therapeutic approaches. The future prospects and challenges in this emerging field will be also discussed.

  8. Anti-microbial photodynamic therapy: useful in the future?

    PubMed

    Maisch, Tim

    2007-06-01

    Previous chapters in this volume have focused on fundamental principles and clinical applications of PDT. This chapter will attempt to outline emerging areas of research to identify some new applications that may become useful in the future in clinical practise. The worldwide rise in antibiotic resistance has driven research to the development of novel anti-microbial strategies. Cutaneous diseases caused by MRSA are ideally suited to treatment by anti-microbial photodynamic therapy for eradicating localized infections and for modulating wound healing due to the ability to deliver photosensitizer and light with topical application. The use of photosensitizer and light as an anti-microbial agent against periodontal microbial biofilms should also represent an attractive method of eliminating oral bacteria. Suitable light sources, laser light and non-coherent light will be briefly covered. This chapter will focus on some aspects of anti-microbial photodynamic therapy that appear to be promising for dermatological indications and inactivation of pathogenic bacteria within the oral cavity.

  9. Photodynamic evaluation of tetracarboxy-phthalocyanines in model systems.

    PubMed

    Alonso, Lais; Sampaio, Renato N; Souza, Thalita F M; Silva, Rodrigo C; Neto, Newton M Barbosa; Ribeiro, Anderson O; Alonso, Antonio; Gonçalves, Pablo J

    2016-08-01

    The present work reports the synthesis, photophysical and photochemical characterization and photodynamic evaluation of zinc, aluminum and metal free-base tetracarboxy-phthalocyanines (ZnPc, AlPc and FbPc, respectively). To evaluate the possible application of phthalocyanines as a potential photosensitizer the photophysical and photochemical characterization were performed using aqueous (phosphate-buffered solution, PBS) and organic (dimethyl sulfoxide, DMSO) solvents. The relative lipophilicity of the compounds was estimated by the octanol-water partition coefficient and the photodynamic activity evaluated through the photooxidation of a protein and photohemolysis. The photooxidation rate constants (k) were obtained and the hemolytic potential was evaluated by the maximum percentage of hemolysis achieved (Hmax) and the time (t50) to reach 50% of the Hmax. Although these phthalocyanines are all hydrophilic and possess very low affinity for membranes (log PO/W=-2.0), they led to significant photooxidation of bovine serum albumin (BSA) and photohemolysis. Our results show that ZnPc was the most efficient photosensitizer, followed by AlPc and FbPc; this order is the same as the order of the triplet and singlet oxygen quantum yields (ZnPc>AlPc>FbPc). Furthermore, together, the triplet, fluorescence and singlet oxygen quantum yields of zinc tetracarboxy-phthalocyanines suggest their potential for use in theranostic applications, which simultaneously combines photodiagnosis and phototherapy. PMID:27232148

  10. Modulation of photosensitization processes for an improved targeted photodynamic therapy.

    PubMed

    Verhille, M; Couleaud, P; Vanderesse, R; Brault, D; Barberi-Heyob, M; Frochot, C

    2010-01-01

    Photodynamic therapy (PDT) is a cancer treatment modality involving the combination of light, a photosensitizer (PS) and molecular oxygen, which results in the production of cytotoxic reactive oxygen species (ROS). Singlet oxygen ((1)O(2)) is one of the most important of these ROS. Because the lifetime and diffusion of (1)O(2) is very limited, a controllable singlet oxygen generation with high selectivity and localization would lead to more efficient and reliable PDT. The lack of selective accumulation of the PS within tumour tissue is a major problem in PDT. Targeted PDT would offer the advantage to enhance photodynamic efficiency by directly targeting diseased cells or tissues. Many attempts have been made to either selectively deliver light to diseased tissues or increase the uptake of the photoactive compounds by the target cells. The review will survey the literature regarding the multi-level control of (1)O(2) production for PDT applications. The mechanisms of ROS formation are described. The different strategies leading to targeted formation of (1)O(2) are developed. Some active PDT agents have been based on energy transfer between PS by control of the aggregation/ disaggregation. The concept of molecular beacon based on quenching-dequenching upon protease cleavage is capable of precise control of (1)O(2) by responding to specific cancer-associated biomarkers.

  11. Hydrogels containing porphyrin-loaded nanoparticles for topical photodynamic applications.

    PubMed

    González-Delgado, José A; Castro, Pedro M; Machado, Alexandra; Araújo, Francisca; Rodrigues, Francisca; Korsak, Bárbara; Ferreira, Marta; Tomé, João P C; Sarmento, Bruno

    2016-08-20

    5,10,15,20-tetrakis(1-methylpyridinium-4-yl)-porphyrin tetra-iodide (TMPyP), a potent water-soluble photosensitizer (PS) used in antimicrobial applications, was encapsulated into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TMPyP-PLGA) for topical delivery purposes. Nanoparticles resulted in a mean particle size around 130nm, narrow polydispersity index (PdI), spherical morphology and association efficiency up to 93%. Free TMPyP and TMPyP-PLGA nanoparticles were incorporated into Carbopol(®) hydrogels, resulting in controlled TMPyP release of about 60% and 20% after 4.5h, respectively. Critical properties such as appearance, clarity, viscosity and pH were maintained over time, as hydrogels were stable during 6 months at 4°C, 25°C/60% RH and 40°C/75% RH. For photodynamic applications, the photoproduction of singlet oxygen from these hydrogels was quite efficient being both formulations very photostable after 20min. No TMPyP permeation through pig ear skin was observed after 24h, and histological assays did not show relevant damages in surrounding tissues. All these excellent characteristics make them promising platforms for photodynamic applications through topical clinical use. PMID:27321129

  12. Optical Imaging, Photodynamic Therapy and Optically-Triggered Combination Treatments

    PubMed Central

    Hasan, Tayyaba

    2015-01-01

    Optical imaging is becoming increasingly promising for real-time image-guided resections and combined with photodynamic therapy (PDT), a photochemistry-based treatment modality, optical approaches can be intrinsically “theranostic”. Challenges in PDT include precise light delivery, dosimetry and photosensitizer tumor localization to establish tumor selectivity, and like all other modalities, incomplete treatment and subsequent activation of molecular escape pathways are often attributable to tumor heterogeneity. Key advances in molecular imaging, target-activatable photosensitizers and optically active nanoparticles that provide both cytotoxicity and a drug release mechanism, have opened exciting avenues to meet these challenges. The focus of the review is optical imaging in the context of PDT but the general principles presented are applicable to many of the conventional approaches to cancer management. We highlight the role of optical imaging in providing structural, functional and molecular information regarding photodynamic mechanisms of action, thereby advancing PDT and PDT-based combination therapies of cancer. These advances represent a PDT renaissance with increasing applications of clinical PDT as a frontline cancer therapy working in concert with fluorescence-guided surgery, chemotherapy and radiation. PMID:26049699

  13. Self-Monitoring Artificial Red Cells with Sufficient Oxygen Supply for Enhanced Photodynamic Therapy

    NASA Astrophysics Data System (ADS)

    Luo, Zhenyu; Zheng, Mingbin; Zhao, Pengfei; Chen, Ze; Siu, Fungming; Gong, Ping; Gao, Guanhui; Sheng, Zonghai; Zheng, Cuifang; Ma, Yifan; Cai, Lintao

    2016-03-01

    Photodynamic therapy has been increasingly applied in clinical cancer treatments. However, native hypoxic tumoural microenvironment and lacking oxygen supply are the major barriers hindering photodynamic reactions. To solve this problem, we have developed biomimetic artificial red cells by loading complexes of oxygen-carrier (hemoglobin) and photosensitizer (indocyanine green) for boosted photodynamic strategy. Such nanosystem provides a coupling structure with stable self-oxygen supply and acting as an ideal fluorescent/photoacoustic imaging probe, dynamically monitoring the nanoparticle biodistribution and the treatment of PDT. Upon exposure to near-infrared laser, the remote-triggered photosensitizer generates massive cytotoxic reactive oxygen species (ROS) with sufficient oxygen supply. Importantly, hemoglobin is simultaneously oxidized into the more active and resident ferryl-hemoglobin leading to persistent cytotoxicity. ROS and ferryl-hemoglobin synergistically trigger the oxidative damage of xenograft tumour resulting in complete suppression. The artificial red cells with self-monitoring and boosted photodynamic efficacy could serve as a versatile theranostic platform.

  14. Cyclodextrin complexed [60]fullerene derivatives with high levels of photodynamic activity by long wavelength excitation.

    PubMed

    Ikeda, Atsushi; Iizuka, Tatsuya; Maekubo, Naotake; Aono, Ryota; Kikuchi, Jun-Ichi; Akiyama, Motofusa; Konishi, Toshifumi; Ogawa, Takuya; Ishida-Kitagawa, Norihiro; Tatebe, Hisashi; Shiozaki, Kazuhiro

    2013-08-01

    We have evaluated the photodynamic activities of C60 derivative·γ-cyclodextrin (γ-CDx) complexes and demonstrated that they were significantly higher than those of the pristine C60 and C70·γ-CDx complexes under photoirradiation at long wavelengths (610-720 nm), which represent the optimal wavelengths for photodynamic therapy (PDT). In particular, the cationic C60 derivative·γ-CDx complex had the highest photodynamic ability because the complex possessed the ability to generate high levels of (1)O2 and provided a higher level of intracellular uptake. The photodynamic activity of this complex was greater than that of photofrin, which is the most widely used of the known clinical photosensitizers. These findings therefore provide a significant level of information toward the optimization of molecular design strategies for the synthesis of fullerene derivatives for PDT. PMID:24900742

  15. Zinc phthalocyanine-conjugated with bovine serum albumin mediated photodynamic therapy of human larynx carcinoma

    NASA Astrophysics Data System (ADS)

    Silva, E. P. O.; Santos, E. D.; Gonçalves, C. S.; Cardoso, M. A. G.; Soares, C. P.; Beltrame, M., Jr.

    2016-10-01

    Phthalocyanines, which are classified as second-generation photosensitizers, have advantageous photophysical properties, and extensive studies have demonstrated their potential applications in photodynamic therapy. The present work describes the preparation of a new zinc phthalocyanine conjugated to bovine serum albumin (compound 4a) and its photodynamic efficiency in human larynx-carcinoma cells (HEp-2 cells). The unconjugated precursor (compound 4) was also studied. Compounds 4 and 4a penetrated efficiently into the cell, exhibiting cytoplasmic localization, and showed no cytotoxicity in the dark. However, high photodynamic activities were observed in HEp-2 cells after treatments with 5 µM photosensitizers and 4.5 J cm-2 light. These conditions were sufficient to decrease the cell viability to 57.93% and 32.75% for compounds 4 and 4a, respectively. The present results demonstrated high photodynamic efficiency of zinc phthalocyanine conjugated with bovine serum albumin in destroying the larynx-carcinoma cells.

  16. In vitro study for photodynamic therapy using Fotolon in glioma treatment

    NASA Astrophysics Data System (ADS)

    Abdel Hamid, Sara; Zimmermann, Wolfgang; Huettenberger, Dirk; Wittig, Rainer; Abdel Kader, Mahmoud; Stepp, Herbert

    2015-07-01

    Several forms of Chlorin e6 and its derivatives are reported as efficient photosensitizers (PS) studied in Photodynamic Therapy (PDT) for oncologic applications. Fotolon® is a pure form of Chlorin e6 trisodium salt developed by Apocare Pharma.

  17. Therapeutic and Aesthetic Uses of Photodynamic Therapy Part five of a five-part series

    PubMed Central

    2009-01-01

    The use of photodynamic therapy has increased dramatically over the past several years. More clinicians are utilizing this therapy and additional indications for its use have become available. The photosensitizers that are utilized for this therapy differ and have been used differently over the past 10 years of our experience with photodynamic therapy. This manuscript examines the photosensitizers and the differences between them as well as reviews the literature on photosensitizers. PMID:20967181

  18. Device for fluorescent control and photodynamic therapy of age-related macula degeneration

    NASA Astrophysics Data System (ADS)

    Loschenov, Victor B.; Meerovich, Gennadii A.; Budzinskaya, M. V.; Ermakova, N. A.; Shevchik, S. A.; Kharnas, Sergey S.

    2004-07-01

    Age-related macula degeneration (AMD) is a wide spread disease the appearance of which leads to poor eyesight and blindness. A method of treatment is not determined until today. Traditional methods, such as laser coagulation and surgical operations are rather traumatic for eye and often bring to complications. That's why recently a photodynamic method of AMD treatment is studied. Based on photodynamic occlusion of choroidal neovascularization (CNV) with minimal injury to overlying neurosensory retina what increases the efficiency.

  19. Investigation of photodynamic therapy optimization for port wine stain using modulation of photosensitizer administration methods.

    PubMed

    Wang, Ying; Zuo, Zhaohui; Liao, Xiaohua; Gu, Ying; Qiu, Haixia; Zeng, Jing

    2013-12-01

    To raise photosensitizer concentration level during the photodynamic therapy process, two new methods of photosensitizer administration were investigated. The first method involves the slow intravenous injection of photosensitizer throughout the first 15 min of irradiation, and the second method involves 30 min fomentation before photosensitizer injection and irradiation. The fluorescence spectra of port wine stain skin were monitored and the therapeutic effect correlated index was calculated with a previously published spectral algorithm. Thirty cases were divided into group A (slow injection of photosensitizer during the first 15 min), group B (fomentation), and group C (control group, traditional injection method), with 10 cases in each group. To analyze the effect of these two new methods, the change of therapeutic effect correlated index values of two photodynamic therapy sessions for each patient were calculated, and the photodynamic therapy outcome was compared. The results showed that the change of therapeutic effect correlated index in group A was slightly more remarkable than that in the control group. The change of therapeutic effect correlated index in group B was similar to that in the control group. Slow injection of photosensitizer during photodynamic therapy has a potential to increase photosensitizer concentration level during photodynamic therapy. However, fomentation before photodynamic therapy has no such potential. There is a need for new methods to be attempted.

  20. Development of Singlet Oxygen Luminescence Kinetics during the Photodynamic Inactivation of Green Algae.

    PubMed

    Bornhütter, Tobias; Pohl, Judith; Fischer, Christian; Saltsman, Irena; Mahammed, Atif; Gross, Zeev; Röder, Beate

    2016-04-13

    Recent studies show the feasibility of photodynamic inactivation of green algae as a vital step towards an effective photodynamic suppression of biofilms by using functionalized surfaces. The investigation of the intrinsic mechanisms of photodynamic inactivation in green algae represents the next step in order to determine optimization parameters. The observation of singlet oxygen luminescence kinetics proved to be a very effective approach towards understanding mechanisms on a cellular level. In this study, the first two-dimensional measurement of singlet oxygen kinetics in phototrophic microorganisms on surfaces during photodynamic inactivation is presented. We established a system of reproducible algae samples on surfaces, incubated with two different cationic, antimicrobial potent photosensitizers. Fluorescence microscopy images indicate that one photosensitizer localizes inside the green algae while the other accumulates along the outer algae cell wall. A newly developed setup allows for the measurement of singlet oxygen luminescence on the green algae sample surfaces over several days. The kinetics of the singlet oxygen luminescence of both photosensitizers show different developments and a distinct change over time, corresponding with the differences in their localization as well as their photosensitization potential. While the complexity of the signal reveals a challenge for the future, this study incontrovertibly marks a crucial, inevitable step in the investigation of photodynamic inactivation of biofilms: it shows the feasibility of using the singlet oxygen luminescence kinetics to investigate photodynamic effects on surfaces and thus opens a field for numerous investigations.

  1. Investigation of photodynamic effect caused by MPPa-PDT on breast cancer Investigation of photodynamic effect caused by MPPa-PDT

    NASA Astrophysics Data System (ADS)

    Tian, Y. Y.; Hu, X. Y.; Leung, W. N.; Yuan, H. Q.; Zhang, L. Y.; Cui, F. A.; Tian, X.

    2012-10-01

    Breast cancer is the common malignant tumor, the incidence increases with age. Photodynamic therapy (PDT) is a new technique applied in tumors, which involves the administration of a tumor localizing photosensitizer and it is followed by the activation of a specific wavelength. Pyropheophorbide-a methyl ester (MPPa), a derivative of chlorophyll, is a novel potent photosensitizer. We are exploring the photodynamic effect caused by MPPa-PDT on breast cancer. The in vitro and in vivo experiments indicate that MPPa is a comparatively ideal photosensitizer which can induce apoptosis in breast cancer.

  2. In vitro photodynamic therapy based on magnetic-luminescent Gd2O3:Yb,Er nanoparticles with bright three-photon up-conversion fluorescence under near-infrared light.

    PubMed

    Li, Hao; Song, Shaoxin; Wang, Wei; Chen, Kezheng

    2015-09-28

    Yb(3+) and Er(3+) co-doped Gd2O3 nanoparticles were synthesized via a simple homogeneous precipitation method followed by subsequent heat treatment. Morphology characterization results showed that these nanoparticles were almost spherical in shape with diameters of 200-400 nm. The particles were further modified by polyethylene glycol (PEG) to improve their suspensibility in water. The sintering temperature was found to greatly influence the fluorescent properties of the products. After calcination at 700-1200 °C, the Gd2O3:Yb,Er nanoparticles could emit bright up-conversion fluorescence under 980 nm near-infrared (NIR) laser light excitation. The mechanism of up-conversion fluorescence was studied in detail and a three-photon process was observed for both green and red up-conversion fluorescence of the Gd2O3:Yb,Er nanoparticles. Different from many other Yb(3+),Er(3+) co-doped up-conversion materials, the prepared Gd2O3:Yb,Er nanoparticles emitted much stronger red light than green light. The reason was investigated and ascribed to the presence of abundant hydroxyl groups on the surface of the nanoparticles as a result of PEGylation. The nanoparticles could be taken up by the human cervical cancer (HeLa) cells and presented low toxicity. Well-selected photodynamic therapy (PDT) drugs, methylene blue (MB) with a UV/Vis absorption maximum (λmax) of 665 nm and 5-aminolevulinic acid (5ALA) which is a precursor of the natural photosensitizer photoporphyrin IX (PpIX) with a λmax of 635 nm, were loaded onto the nanoparticles respectively to obtain Gd2O3:Yb,Er-MB and Gd2O3:Yb,Er-5ALA nanoparticles. Being up-conversion nanoparticles (UCNPs), the taken up Gd2O3:Yb,Er nanoparticles exposed to 980 nm laser light emitted red fluorescence which activated the loaded MB and PpIX, and then killed the HeLa cells via a PDT mechanism. In vitro therapeutic investigation evidenced the prominent PDT effects of Gd2O3:Yb,Er-MB and Gd2O3:Yb,Er-5ALA upon NIR light irradiation. In

  3. Physicochemical properties of potential porphyrin photosensitizers for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Kempa, Marta; Kozub, Patrycja; Kimball, Joseph; Rojkiewicz, Marcin; Kuś, Piotr; Gryczyński, Zugmunt; Ratuszna, Alicja

    2015-07-01

    This research evaluated the suitability of synthetic photosensitizers for their use as potential photosensitizers in photodynamic therapy using steady state and time-resolved spectroscopic techniques. Four tetraphenylporphyrin derivatives were studied in ethanol and dimethyl sulfoxide. The spectroscopic properties namely electronic absorption and emission spectra, ability to generate singlet oxygen, lifetimes of the triplet state, as well as their fluorescence quantum yield were determined. Also time-correlated single photon counting method was used to precisely determine fluorescence lifetimes for all four compounds. Tested compounds exhibit high generation of singlet oxygen, low generation of fluorescence and they are chemical stable during irradiation. The studies show that the tested porphyrins satisfy the conditions of a potential drug in terms of physicochemical properties.

  4. Transient Increased Exudation after Photodynamic Therapy of Intraocular Tumors

    PubMed Central

    Mashayekhi, Arman; Shields, Carol L.; Shields, Jerry A.

    2013-01-01

    To report transient increased exudation after photodynamic therapy (PDT) of three different intraocular tumors (retinal hemangioblastoma, retinal astrocytoma, amelanotic choroidal melanoma). PDT with verteporfin (6 mg/m2 body surface area) was delivered at a dose of 50 J/cm2 and intensity of 600 mW/cm2 over 83 s. All patients experienced decreased vision within a few days following PDT. Optical coherence tomography showed development of subfoveal fluid in all cases and noncystoid intraretinal edema in the eye with juxtapapillary retinal hemangioblastoma. There was complete absorption of retinal/subretinal fluid with improvement of visual acuity to 20/20 in all cases between 3 weeks to 4 months after PDT. PMID:23580859

  5. Intraoperative photodynamic therapy on spontaneous canine nasal tumors

    NASA Astrophysics Data System (ADS)

    Fonda, Diego; Mortellaro, Carlo M.; Romussi, Stefano; Taroni, Paola; Cubeddu, Rinaldo

    1994-09-01

    Promising results obtained by photodynamic therapy (PDT) with porphyrins on superficial spontaneous canine tumors suggested the experiment of this technique on intracavitary tumors, specifically at the endonasal site. The supposed neoplastic residual bed was irradiated directly during surgery at the end of the debulking. Five dogs referred to the surgical department of the veterinary school, University of Milan and affected by endonasal neoplasias were submitted to PDT after radiologic and cyto-histologic diagnosis and TNM stadiation. All the selected tumors were included in the clinical stage 1 (T1NOMO). Mean and median survival time (from the day of treatment) were 11.6 - 5.4 and 12 months, respectively. Different staging of the treated tumors limits the possibility of an objective comparison with other alternative therapeutic procedures.

  6. Blue laser system for photo-dynamic therapy

    NASA Astrophysics Data System (ADS)

    Dabu, R.; Carstocea, B.; Blanaru, C.; Pacala, O.; Stratan, A.; Ursu, D.; Stegaru, F.

    2007-03-01

    A blue laser system for eye diseases (age related macular degeneration, sub-retinal neo-vascularisation in myopia and presumed ocular histoplasmosis syndrome - POHS) photo-dynamic therapy, based on riboflavin as photosensitive substance, has been developed. A CW diode laser at 445 nm wavelength was coupled through an opto-mechanical system to the viewing path of a bio-microscope. The laser beam power in the irradiated area is adjustable between 1 mW and 40 mW, in a spot of 3-5 mm diameter. The irradiation time can be programmed in the range of 1-19 minutes. Currently, the laser system is under clinic tests.

  7. Photodynamic Therapy with Blended Conducting Polymer/Fullerene Nanoparticle Photosensitizers.

    PubMed

    Doshi, Mona; Gesquiere, Andre J

    2015-10-28

    In this article a method for the fabrication and reproducible in-vitro evaluation of conducting polymer nanoparticles blended with fullerene as the next generation photosensitizers for Photodynamic Therapy (PDT) is reported. The nanoparticles are formed by hydrophobic interaction of the semiconducting polymer MEH-PPV (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]) with the fullerene PCBM (phenyl-C61-butyric acid methyl ester) in the presence of a non-compatible solvent. MEH-PPV has a high extinction coefficient that leads to high rates of triplet formation, and efficient charge and energy transfer to the fullerene PCBM. The latter processes enhance the efficiency of the PDT system through fullerene assisted triplet and radical formation, and ultrafast deactivation of MEH-PPV excited stated. The results reported here show that this nanoparticle PDT sensitizing system is highly effective and shows unexpected specificity to cancer cell lines.

  8. Evaluating Photodynamic Therapy Efficacy Using Laser Induced Breakdown Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fekry, O.; El-Batanouny, M. H.; El-Begawy, M. B.; Harith, M. A.

    2011-09-01

    Laser-induced breakdown spectroscopy (LIBS), is an excellent tool for trace elemental analysis, was exploited for a detecting concentrations of calcium and magnesium in malignant tissues before and after PDT. Calcium and magnesium concentrations are known tobe high in malignancy. Tissues were injected with methylene blue photosensitizer with concentrations 0.5%, 1% and 2%. Two different light sources were used with two different energy densities/each light sources. The results showed a decrease in tissue elements content after PDT application for both calcium and magnesium compared to before PDT application as shown in the tissue spectral lines' intensities which has been reflected in. Type of light source showed no effect on tissue elements content which showed slight differences among the different energy densities. It has been shown that LIBS technique can be adopted method to monitor tumor photodynamic therapy applications.

  9. Photodynamic therapy of cancer with the photosensitizer PHOTOGEM

    NASA Astrophysics Data System (ADS)

    Sokolov, Victor V.; Chissov, Valery I.; Filonenko, E. V.; Sukhin, Garry M.; Yakubovskaya, Raisa I.; Belous, T. A.; Zharkova, Natalia N.; Kozlov, Dmitrij N.; Smirnov, V. V.

    1995-01-01

    The first clinical trials of photodynamic therapy (PDT) in Russia were started in P. A. Hertzen Moscow Research Oncology Institute in October of 1992. Up to now, 61 patients with primary or recurrent malignant tumors of the larynx (3), trachea (1), bronchus (11), nose (1), mouth (3), esophagus (12), vagina and uterine cervix (3), bladder (2), skin (6), and cutaneous and subcutaneous metastases of breast cancer and melanomas (6) have been treated by PDT with the photosensitizer Photogem. At least partial tumor response was observed in all of the cases, but complete remission indicating no evident tumors has been reached in 51% of the cases. Among 29 patients with early and first stage cancer 14 patients had multifocal tumors. Complete remission of tumors in this group reached 86%.

  10. TOPICAL REVIEW: The physics, biophysics and technology of photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Wilson, Brian C.; Patterson, Michael S.

    2008-05-01

    Photodynamic therapy (PDT) uses light-activated drugs to treat diseases ranging from cancer to age-related macular degeneration and antibiotic-resistant infections. This paper reviews the current status of PDT with an emphasis on the contributions of physics, biophysics and technology, and the challenges remaining in the optimization and adoption of this treatment modality. A theme of the review is the complexity of PDT dosimetry due to the dynamic nature of the three essential components—light, photosensitizer and oxygen. Considerable progress has been made in understanding the problem and in developing instruments to measure all three, so that optimization of individual PDT treatments is becoming a feasible target. The final section of the review introduces some new frontiers of research including low dose rate (metronomic) PDT, two-photon PDT, activatable PDT molecular beacons and nanoparticle-based PDT.

  11. Current evidence and applications of photodynamic therapy in dermatology

    PubMed Central

    Wan, Marilyn T; Lin, Jennifer Y

    2014-01-01

    In photodynamic therapy (PDT) a photosensitizer – a molecule that is activated by light – is administered and exposed to a light source. This leads both to destruction of cells targeted by the particular type of photosensitizer, and immunomodulation. Given the ease with which photosensitizers and light can be delivered to the skin, it should come as no surprise that PDT is an increasingly utilized therapeutic in dermatology. PDT is used commonly to treat precancerous cells, sun-damaged skin, and acne. It has reportedly also been used to treat other conditions including inflammatory disorders and cutaneous infections. This review discusses the principles behind how PDT is used in dermatology, as well as evidence for current applications of PDT. PMID:24899818

  12. [Palliative locoregional therapy for hilar cholangiocarcinoma: photodynamic therapy and brachytherapy].

    PubMed

    Dumoulin, F L; Horst, E; Sauerbruch, T; Gerhardt, T

    2007-08-01

    In hilar cholangiocarcinoma, only 20-30% of the patients are candidates for curative surgical resection, leaving the majority with merely palliative treatment options. Since the natural history of hilar cholangiocarcinoma is dominated by local complications rather than metastatic disease, local palliative treatment seems a reasonable option. Here, endoluminal photodynamic therapy has emerged as a promising treatment with several prospective observational studies and 2 prospective randomised studies published which included nearly 200 patients. With low complication rate and morbidity, PDT achieves an increased median survival as well as an increased quality of life even in patients with reduced performance status. Radiotherapy is an alternative local treatment option applied as brachytherapy, external beam radiotherapy or combined modality treatment. To date, however, sufficient data from controlled clinical trials are lacking, thus palliative radiotherapy has to be considered an experimental treatment option.

  13. Towards Effective Photothermal/Photodynamic Treatment Using Plasmonic Gold Nanoparticles

    PubMed Central

    Bucharskaya, Alla; Maslyakova, Galina; Terentyuk, Georgy; Yakunin, Alexander; Avetisyan, Yuri; Bibikova, Olga; Tuchina, Elena; Khlebtsov, Boris; Khlebtsov, Nikolai; Tuchin, Valery

    2016-01-01

    Gold nanoparticles (AuNPs) of different size and shape are widely used as photosensitizers for cancer diagnostics and plasmonic photothermal (PPT)/photodynamic (PDT) therapy, as nanocarriers for drug delivery and laser-mediated pathogen killing, even the underlying mechanisms of treatment effects remain poorly understood. There is a need in analyzing and improving the ways to increase accumulation of AuNP in tumors and other crucial steps in interaction of AuNPs with laser light and tissues. In this review, we summarize our recent theoretical, experimental, and pre-clinical results on light activated interaction of AuNPs with tissues and cells. Specifically, we discuss a combined PPT/PDT treatment of tumors and killing of pathogen bacteria with gold-based nanocomposites and atomic clusters, cell optoporation, and theoretical simulations of nanoparticle-mediated laser heating of tissues and cells. PMID:27517913

  14. Photodynamic detection and treatment of squamous cell carcinoma

    NASA Astrophysics Data System (ADS)

    Vari, Sandor G.; Pergadia, Vani R.; Papaioannou, Thanassis; Snyder, Wendy J.; Marcus, J.; Glassberg, Edward; Dimino-Emme, L.; Fishbein, Michael C.; Thomas, Reem; Dhondt, M. D.; Lask, Gary P.; Grundfest, Warren S.

    1994-02-01

    In this study the fluorescence intensity of photosensitizer in squamous cell tumors were quantified in terms of the tumor resolution rate. A He-Cd laser (442 nm - 17 mW) with a 600 micrometers core silica fiber was used for excitation. The same fiber was used for fluorescence acquisition and an optical multichannel analyzer (EG&G, OMA III) was used to analyze the fluorescence. Twelve days after carcinoma inoculation fluorescence signal from the tumor and skin (1 cm radius from the tumor) at the 12, 3, 6, and 9 o'clock positions were recorded. Benzoporphyrin Derivative (QLT, Canada -- 2 mg/kg of body weight) was then injected into the tail vein. The drug was photoactivated with a 690 nm modified argon pump cw-dye laser (Medtech) operating at 140 mW/cm2 for 15 mins. LIFS is capable of localizing in situ malignancy and evaluating photosensitizers for photodynamic fluorescence detection and therapy of tumors.

  15. Photodynamic therapy in dermatology: state-of-the-art.

    PubMed

    Babilas, Philipp; Schreml, Stephan; Landthaler, Michael; Szeimies, Rolf-Markus

    2010-06-01

    Photodynamic therapy (PDT) has become an established treatment modality for dermatooncologic conditions like actinic keratosis, Bowen's disease, in situ squamous cell carcinoma and superficial basal cell carcinoma. There is also great promise of PDT for many non-neoplastic dermatological diseases like localized scleroderma, acne vulgaris, granuloma anulare and leishmaniasis. Aesthetic indications like photo-aged skin or sebaceous gland hyperplasia complete the range of applications. Major advantages of PDT are the low level of invasiveness and the excellent cosmetic results. Here, we review the principal mechanism of action, the current developments in the field of photosensitizers and light sources, practical aspects of topical PDT and therapeutical applications in oncologic as well as non-oncologic indications. PMID:20584250

  16. Physical and mathematical modeling of antimicrobial photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Bürgermeister, Lisa; López, Fernando Romero; Schulz, Wolfgang

    2014-07-01

    Antimicrobial photodynamic therapy (aPDT) is a promising method to treat local bacterial infections. The therapy is painless and does not cause bacterial resistances. However, there are gaps in understanding the dynamics of the processes, especially in periodontal treatment. This work describes the advances in fundamental physical and mathematical modeling of aPDT used for interpretation of experimental evidence. The result is a two-dimensional model of aPDT in a dental pocket phantom model. In this model, the propagation of laser light and the kinetics of the chemical reactions are described as coupled processes. The laser light induces the chemical processes depending on its intensity. As a consequence of the chemical processes, the local optical properties and distribution of laser light change as well as the reaction rates. The mathematical description of these coupled processes will help to develop treatment protocols and is the first step toward an inline feedback system for aPDT users.

  17. Effects of verteporfin-mediated photodynamic therapy on endothelial cells

    NASA Astrophysics Data System (ADS)

    Kraus, Daniel; Chen, Bin

    2015-03-01

    Photodynamic therapy (PDT) is a treatment modality in which cytotoxic reactive oxygen species are generated from oxygen and other biological molecules when a photosensitizer is activated by light. PDT has been approved for the treatment of cancers and age-related macular degeneration (AMD) due to its effectiveness in cell killing and manageable normal tissue complications. In this study, we characterized the effects of verteporfin-PDT on SVEC mouse endothelial cells and determined its underlying cell death mechanisms. We found that verteporfin was primarily localized in mitochondria and endoplasmic reticulum (ER) in SVEC cells. Light treatment of photosensitized SVEC cells induced a rapid onset of cell apoptosis. In addition to significant structural damages to mitochondria and ER, verteporfin-PDT caused substantial degradation of ER signaling molecules, suggesting ER stress. These results demonstrate that verteporfin-PDT triggered SVEC cell apoptosis by both mitochondrial and ER stress pathways. Results from this study may lead to novel therapeutic approaches to enhance PDT outcome.

  18. Bioluminescence-activated deep-tissue photodynamic therapy of cancer.

    PubMed

    Kim, Yi Rang; Kim, Seonghoon; Choi, Jin Woo; Choi, Sung Yong; Lee, Sang-Hee; Kim, Homin; Hahn, Sei Kwang; Koh, Gou Young; Yun, Seok Hyun

    2015-01-01

    Optical energy can trigger a variety of photochemical processes useful for therapies. Owing to the shallow penetration of light in tissues, however, the clinical applications of light-activated therapies have been limited. Bioluminescence resonant energy transfer (BRET) may provide a new way of inducing photochemical activation. Here, we show that efficient bioluminescence energy-induced photodynamic therapy (PDT) of macroscopic tumors and metastases in deep tissue. For monolayer cell culture in vitro incubated with Chlorin e6, BRET energy of about 1 nJ per cell generated as strong cytotoxicity as red laser light irradiation at 2.2 mW/cm(2) for 180 s. Regional delivery of bioluminescence agents via draining lymphatic vessels killed tumor cells spread to the sentinel and secondary lymph nodes, reduced distant metastases in the lung and improved animal survival. Our results show the promising potential of novel bioluminescence-activated PDT.

  19. Enhancing antibiofilm efficacy in antimicrobial photodynamic therapy: effect of microbubbles

    NASA Astrophysics Data System (ADS)

    Kishen, Anil; George, Saji

    2013-02-01

    In this study, we tested the hypothesis that a microbubble containing photosensitizer when activated with light would enable comprehensive disinfection of bacterial biofilms in infected root dentin by antimicrobial photodynamic therapy (APDT). Experiments were conducted in two stages. In the stage-1, microbubble containing photosensitizing formulation was tested for its photochemical properties. In the stage-2, the efficacy of microbubble containing photosensitizing formulation was tested on in vitro infected root canal model, developed with monospecies biofilm models of Enterococcus faecalis on root dentin substrate. The findings from this study showed that the microbubble containing photosensitizing formulation was overall the most effective formulation for photooxidation, generation of singlet oxygen, and in disinfecting the biofilm bacteria in the infected root canal model. This modified photosensitizing formulation will have potential advantages in eliminating bacterial biofilms from infected root dentin.

  20. Bioluminescence-Activated Deep-Tissue Photodynamic Therapy of Cancer

    PubMed Central

    Kim, Yi Rang; Kim, Seonghoon; Choi, Jin Woo; Choi, Sung Yong; Lee, Sang-Hee; Kim, Homin; Hahn, Sei Kwang; Koh, Gou Young; Yun, Seok Hyun

    2015-01-01

    Optical energy can trigger a variety of photochemical processes useful for therapies. Owing to the shallow penetration of light in tissues, however, the clinical applications of light-activated therapies have been limited. Bioluminescence resonant energy transfer (BRET) may provide a new way of inducing photochemical activation. Here, we show that efficient bioluminescence energy-induced photodynamic therapy (PDT) of macroscopic tumors and metastases in deep tissue. For monolayer cell culture in vitro incubated with Chlorin e6, BRET energy of about 1 nJ per cell generated as strong cytotoxicity as red laser light irradiation at 2.2 mW/cm2 for 180 s. Regional delivery of bioluminescence agents via draining lymphatic vessels killed tumor cells spread to the sentinel and secondary lymph nodes, reduced distant metastases in the lung and improved animal survival. Our results show the promising potential of novel bioluminescence-activated PDT. PMID:26000054

  1. Systemic estimation of the effect of photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Kogan, Eugenia A.; Meerovich, Gennadii A.; Torshina, Nadezgda L.; Loschenov, Victor B.; Volkova, Anna I.; Posypanova, Anna M.

    1997-12-01

    The effects of photodynamic therapy (PDT) of cancer needs objective estimation and its unification in experimental as well as in clinical studies. They must include not only macroscopical changes but also the complex of following morphological criteria: (1) the level of direct tumor damage (direct necrosis and apoptosis); (2) the level of indirect tumor damage (ischemic necrosis); (3) the signs of vascular alterations; (4) the local and systemic antiblastome resistance; (5) the proliferative activity and malignant potential of survival tumor tissue. We have performed different regimes PDT using phthalocyanine derivatives. The complex of morphological methods (Ki-67, p53, c-myc, bcl-2) was used. Obtained results showed the connection of the tilted morphological criteria with tumor regression.

  2. Photodynamic therapy in dermatology: past, present, and future

    NASA Astrophysics Data System (ADS)

    Darlenski, Razvigor; Fluhr, Joachim W.

    2013-06-01

    Photodynamic therapy (PDT) is a noninvasive therapeutic method first introduced in the field of dermatology. It is mainly used for the treatment of precancerous and superficial malignant skin tumors. Today PDT finds new applications not only for nononcologic dermatoses but also in the field of other medical specialties such as otorhinolaryngology, ophthalmology, neurology, gastroenterology, and urology. We are witnessing a broadening of the spectrum of skin diseases that are treated by PDT. Since its introduction, PDT protocol has evolved significantly in terms of increasing method efficacy and patient safety. In this era of evidence-based medicine, it is expected that much effort will be put into creating a worldwide accepted consensus on PDT. A review on the current knowledge of PDT is given, and the historical basis of the method's evolution since its introduction in the 1900s is presented. At the end, future challenges of PDT are focused on discussing gaps that exist for research in the field.

  3. Daylight-mediated photodynamic therapy in Spain: advantages and disadvantages.

    PubMed

    Pérez-Pérez, L; García-Gavín, J; Gilaberte, Y

    2014-09-01

    Photodynamic therapy (PDT) is an option for the treatment of actinic keratosis, Bowen disease, and certain types of basal cell carcinoma. It is also used to treat various other types of skin condition, including inflammatory and infectious disorders. The main disadvantages of PDT are the time it takes to administer (both for the patient and for health professionals) and the pain associated with treatment. Daylight-mediated PDT has recently been reported to be an alternative to the conventional approach. Several studies have shown it to be similar in efficacy to and better tolerated than classic PDT for the treatment of mild to moderate actinic keratosis. Nevertheless, most of these studies are from northern Europe, and no data have been reported from southern Europe. The present article reviews the main studies published to date, presents the treatment protocol, and summarizes our experience with a group of treated patients.

  4. Fat tissue staining and photodynamic/photothermal effects

    NASA Astrophysics Data System (ADS)

    Tuchin, Valery V.; Altshuler, Gregory B.; Yanina, Irina Yu.; Kochubey, Vyacheslav I.; Simonenko, Georgy V.

    2010-02-01

    Cellulite is considered as a disease of the subcutaneous fat layer that appears mostly in women and consists of changes in fat cell accumulation together with disturbed lymphatic drainage, affecting the external appearance of the skin. The photodynamic and selective photothermal treatments may provide reduction the volume of regional or sitespecific accumulations of subcutaneous adipose tissue on the cellular level. We hypothesize that light irradiation of stained fat tissue at selected temperature leads to fat cell lypolytic activity (the enhancement of lipolysis of cell triglycerides due to expression of lipase activity and cell release of free fat acids (FFAs) due to temporal cell membrane porosity), and cell killing due to apoptosis caused by the induced fat cell stress and/or limited cell necrosis.

  5. Photodynamic therapy of head and neck cancer with different sensitizers

    NASA Astrophysics Data System (ADS)

    Vakoulovskaya, Elena G.; Shental, Victor V.; Abdoullin, N. A.; Kuvshinov, Yury P.; Tabolinovskaia, T. D.; Edinak, N. J.; Poddubny, Boris K.; Kondratjeva, T. T.; Meerovich, Gennadii A.; Stratonnikov, Alexander A.; Linkov, Kirill G.; Agafonov, Valery V.

    1997-12-01

    This paper deals with the results of clinical trials for sulfated aluminum phthalocyanine (PHS) (Photosens, Russia; Photogeme (PG) in Russia. The results of photodynamic therapy (PDT) of head and neck tumors (HNT), side effects and ways of their correction and prevention, as well as possibility to work out less toxic regimes of PDT with photosense, choice of laser and type of irradiation are discussed. PDT have been provided in 79 patients with different head and neck tumors. Efficacy of PDT depended on tumor size and its histological type. Undesirable changes in plasma content of antioxidants by means of high pressure liquid chromatography (HLPC) have been found in patients after PHS injection. Influence of short-term and long-term supplementation with beta-carotene and vitamin E on this parameters are discussed.

  6. Photodynamic method of diagnosis and treatment of intraocular melanoma

    NASA Astrophysics Data System (ADS)

    Kecik, Tadeusz; Switka-Wieclawska, Iwona; Kasprzak, Jan; Graczyk, Alfreda; Pratnicki, Antoni

    1993-06-01

    Malignant melanoma is the most prevalent and the most dangerous primary intraocular tumor. The most common treatment until recently was enucleation. In our experimental work we would like to present the use of hematoporphyrin derivative photodynamic therapy (HpD- PDT) in diagnosis and treatment of cancer. Eighteen eyes of rabbits were incubated intracamerally with amelanotic Greene melanoma tissue. The technique involves the administration of HpD and photoactivation of the tumor with violet light (406 nm) for diagnostic purposes and with red light (630 nm) to achieve selective destruction of cancer cells. After photoradiation the tumor showed blanching and shrinkage, we could also observe the tumor vasculature damage. Successfully treated tumors had large areas of necrosis with severely damaged blood vessels in histopathological examination. Results indicate that HpD- PDT is a very promising modern modality offering new diagnostic and treatment methods for melanoma.

  7. Towards Effective Photothermal/Photodynamic Treatment Using Plasmonic Gold Nanoparticles.

    PubMed

    Bucharskaya, Alla; Maslyakova, Galina; Terentyuk, Georgy; Yakunin, Alexander; Avetisyan, Yuri; Bibikova, Olga; Tuchina, Elena; Khlebtsov, Boris; Khlebtsov, Nikolai; Tuchin, Valery

    2016-01-01

    Gold nanoparticles (AuNPs) of different size and shape are widely used as photosensitizers for cancer diagnostics and plasmonic photothermal (PPT)/photodynamic (PDT) therapy, as nanocarriers for drug delivery and laser-mediated pathogen killing, even the underlying mechanisms of treatment effects remain poorly understood. There is a need in analyzing and improving the ways to increase accumulation of AuNP in tumors and other crucial steps in interaction of AuNPs with laser light and tissues. In this review, we summarize our recent theoretical, experimental, and pre-clinical results on light activated interaction of AuNPs with tissues and cells. Specifically, we discuss a combined PPT/PDT treatment of tumors and killing of pathogen bacteria with gold-based nanocomposites and atomic clusters, cell optoporation, and theoretical simulations of nanoparticle-mediated laser heating of tissues and cells. PMID:27517913

  8. Cationic porphycenes as potential photosensitizers for antimicrobial photodynamic therapy

    PubMed Central

    Ragàs, Xavier; Sánchez-García, David; Ruiz-González, Rubén; Dai, Tianhong; Agut, Montserrat; Hamblin, Michael R.; Nonell, Santi

    2010-01-01

    Structures of typical photosensitizers used in antimicrobial photodynamic therapy are based on porphyrins, phthalocyanines and phenothiazinium salts, with cationic charges at physiological pH values. However derivatives of the porphycene macrocycle (a structural isomer of porphyrin) have barely been investigated as antimicrobial agents. Therefore, we report the synthesis of the first tricationic water-soluble porphycene and its basic photochemical properties. We successfully tested it for in vitro photoinactivation of different Gram-positive and Gram-negative bacteria, as well as a fungal species (Candida) in a drug-dose and light-dose dependent manner. We also used the cationic porphycene in vivo to treat an infection model comprising mouse 3rd degree burns infected with a bioluminescent methicillin-resistant Staphylococcus aureus strain. There was a 2.6-log10 reduction (p < 0.001) of the bacterial bioluminescence for the PDT-treated group after irradiation with 180 J·cm-2 of red light. PMID:20936792

  9. Facile synthesis of advanced photodynamic molecular beacon architectures.

    PubMed

    Lovell, Jonathan F; Chen, Juan; Huynh, Elizabeth; Jarvi, Mark T; Wilson, Brian C; Zheng, Gang

    2010-06-16

    Nucleic acid photodynamic molecular beacons (PMBs) are a class of activatable photosensitizers that increase singlet oxygen generation upon binding a specific target sequence. Normally, PMBs are functionalized with multiple solution-phase labeling and purification steps. Here, we make use of a flexible solid-phase approach for completely automated synthesis of PMBs. This enabled the creation of a new type of molecular beacon that uses a linear superquencher architecture. The 3' terminus was labeled with a photosensitizer by generating pyropheophorbide-labeled solid-phase support. The 5' terminus was labeled with up to three consecutive additions of a dark quencher phosphoramidite. These photosensitizing and quenching moieties were stable in the harsh DNA synthesis environment and their hydrophobicity facilitated PMB purification by HPLC. Linear superquenchers exhibited highly efficient quenching. This fully automated synthesis method simplifies not only the synthesis and purification of PMBs, but also the creation of new activatable photosensitizer designs.

  10. Photodynamic therapy-driven induction of suicide cytosine deaminase gene.

    PubMed

    Bil, Jacek; Wlodarski, Pawel; Winiarska, Magdalena; Kurzaj, Zuzanna; Issat, Tadeusz; Jozkowicz, Alicja; Wegiel, Barbara; Dulak, Jozef; Golab, Jakub

    2010-04-28

    Photodynamic therapy (PDT) of tumors is associated with induction of hypoxia that results in activation of hypoxia-inducible factors (HIFs). Several observations indicate that increased HIFs transcriptional activity in tumor cells is associated with cytoprotective responses that limit cytotoxic effectiveness of PDT. Therefore, we decided to examine whether this cytoprotective mechanism could be intentionally used for designing more efficient tumor cell cytotoxicity. To this end we transfected tumor cells with a plasmid vector carrying a suicide cytosine deaminase gene driven by a promoter containing hypoxia response elements (HRE). The presence of such a genetic molecular beacon rendered tumor cells sensitive to cytotoxic effects of a non-toxic prodrug 5-fluorocytosine (5-FC). The results of this study provides a proof of concept that inducible cytoprotective mechanisms can be exploited to render tumor cells more susceptible to cytotoxic effects of prodrugs activated by products of suicide genes.

  11. Effects of photodynamic therapy on human glioma spheroids

    NASA Astrophysics Data System (ADS)

    Madsen, Steen J.; Sun, Chung-Ho; Chu, Eugene A.; Hirschberg, Henry; Tromberg, Bruce J.

    1999-07-01

    The poor prognosis for patients with malignant brain neoplasm has led to a search for better treatment modalities. Although gliomas are considered to be disseminated tumors in the brain, most recur at the site of the previous tumor resection. Improved local control would thus be of clear benefit. The utility of photodynamic therapy (PDT) in the treatment of brain neoplasms is investigated using a human glioma spheroid model. Specifically, the effects of PDT on human glioma spheroids are investigated using PhotofrinTM and 56-aminolevulinic acid (ALA). The effects of various irradiation schemes were monitored using a simple growth assay. A growth delay was observed at an optical fluence of approximately 35 J cm-2 for spheroids incubated in Photofrin. Spheroids incubated in ALA were unaffected by the PDT treatment regimens examined in this study. This was most likely a result of inadequate photosensitizer concentration.

  12. 5-ALA-assisted photodynamic therapy in canine prostates

    NASA Astrophysics Data System (ADS)

    Sroka, Ronald; Muschter, Rolf; Knuechel, Ruth; Steinbach, Pia; Perlmutter, Aaron P.; Martin, Thomas; Baumgartner, Reinhold

    1996-05-01

    Photodynamic therapy (PDT) and interstitial thermotherapy are well known treatment modalities in urology. The approach of this study is to combine both to achieve a selective treatment procedure for benign prostatic hyperplasia (BPH) and prostate carcinoma. Measurements of thy in-vivo pharmacokinetics of 5-ALA induced porphyrins by means of fiber assisted ratiofluorometry showed a maximum fluorescence intensity at time intervals of 3 - 4 h post administration. Fluorescence microscopy at that time showed bright fluorescence in epithelial cells while in the stroma fluorescence could not be observed. Interstitial PDT using a 635-nm dye laser with an irradiation of 50 J/cm2 resulted in a nonthermic hemorrhagic lesion. The lesion size did not change significantly when an irradiation of 100 J/cm2 was used. The usefulness of PDT for treating BPH as well as prostate carcinoma has to be proven in further studies.

  13. Photodynamic therapy of Cervical Intraepithelial Neoplasia (CIN) high grade

    NASA Astrophysics Data System (ADS)

    Carbinatto, Fernanda M.; Inada, Natalia M.; Lombardi, Welington; da Silva, Eduardo V.; Belotto, Renata; Kurachi, Cristina; Bagnato, Vanderlei S.

    2016-02-01

    Cervical intraepithelial neoplasia (CIN) is the precursor of invasive cervical cancer and associated with human papillomavirus (HPV) infection. Photodynamic therapy (PDT) is a technique that has been used for the treatment of tumors. PDT is based on the accumulation of a photosensitizer in target cells that will generate cytotoxic reactive oxygen species upon illumination, inducing the death of abnormal tissue and PDT with less damaging to normal tissues than surgery, radiation, or chemotherapy and seems to be a promising alternative procedure for CIN treatment. The CIN high grades (II and III) presents potential indications for PDT due the success of PDT for CIN low grade treatment. The patients with CIN high grade that were treated with new clinic protocol shows lesion regression to CIN low grade 60 days after the treatment. The new clinical protocol using for treatment of CIN high grade shows great potential to become a public health technique.

  14. [Use of nanoparticles (NP) in photodynamic therapy (PDT) against cancer].

    PubMed

    Roblero-Bartolón, Gabriela Victoria; Ramón-Gallegos, Eva

    2015-01-01

    Nanotechnology is a promising interdisciplinary field for developing improved methods of diagnosis and treatment of different diseases, including cancer. Give their optical, magnetic, and structural property, the nanoparticles have been proposed to be use in the development of unconventional treatments for cancer such as photodynamic therapy (PDT). In PDT, a photosensitizing agent is used that accumulates in tumor cells, generating reactive oxygen species that causes the death of malignant cells after irradiation with light at a particular wavelength. However, the use of PDT presents different problems in its application due to the characteristics of hydrophobicity of the photosensitizers, which hinder the efficiency of administration and treatment. It is here where the use of nanoparticles is proposed as a delivery vehicle to optimize treatment application. In this review we describe the use of nanoparticles coupled to PDT in the treatment of cancer and its molecular mechanism of action. PMID:25739488

  15. Porphyrin-based Nanostructure-Dependent Photodynamic and Photothermal Therapies

    NASA Astrophysics Data System (ADS)

    Jin, Cheng S.

    This thesis presents the investigation of nanostructure-dependent phototherapy. We reviewed the liposomal structures for delivery of photosensitizers, and introduced a novel class of phototransducing liposomes called "porphysomes". Porphysomes are self-assembled from high packing density of pyropheophorbide alpha-conjugated phospholipids, resulting in extreme self-quenching of porphyrin fluorescence and comparable optical absorption to gold nanoparticles for high photothermal efficiency. We demonstrated this self-assembly of porphyrin-lipid conjugates converts a singlet oxygen generating mechanism (photodynamic therapy PDT activity) of porphyrin to photothermal mechanism (photothermal therapy PTT activity). The efficacy of porphysome-enhanced PTT was then evaluated on two pre-clinical animal models. We validated porphysome-enabled focal PTT to treat orthotopic prostate cancer using MRI-guided focal laser placement to closely mimic the current clinic procedure. Furthermore, porphysome-enabled fluorescence-guided transbronchial PTT of lung cancer was demonstrated in rabbit orthotopic lung cancer models, which led to the development of an ultra-minimally invasive therapy for early-stage peripheral lung cancer. On the other hand, the nanostructure-mediated conversion of PDT to PTT can be switched back by nanoparticle dissociation. By incorporating folate-conjugated phospholipids into the formulation, porphysomes were internalized into cells rapidly via folate receptor-mediated endocytosis and resulted in efficient disruption of nanostructures, which turned back on the photodynamic activity of densely packed porphyrins, making a closed loop of conversion between PDT and PTT. The multimodal imaging and therapeutic features of porphysome make it ideal for future personalized cancer treatments.

  16. Hypericin in the Dark: Foe or Ally in Photodynamic Therapy?

    PubMed Central

    Huntosova, Veronika; Stroffekova, Katarina

    2016-01-01

    Photosensitizers (PSs) in photodynamic therapy (PDT) are, in most cases, administered systemically with preferential accumulation in malignant tissues; however, exposure of non-malignant tissues to PS may also be clinically relevant, when PS molecules affect the pro-apoptotic cascade without illumination. Hypericin (Hyp) as PS and its derivatives have long been studied, regarding their photodynamic and photocytotoxic characteristics. Hyp and its derivatives have displayed light-activated antiproliferative and cytotoxic effects in many tumor cell lines without cytotoxicity in the dark. However, light-independent effects of Hyp have emerged. Contrary to the acclaimed Hyp minimal dark cytotoxicity and preferential accumulation in tumor cells, it was recently been shown that non-malignant and malignant cells uptake Hyp at a similar level. In addition, Hyp has displayed light-independent toxicity and anti-proliferative effects in a wide range of concentrations. There are multiple mechanisms underlying Hyp light-independent effects, and we are still missing many details about them. In this paper, we focus on Hyp light-independent effects at several sub-cellular levels—protein distribution and synthesis, organelle ultrastructure and function, and Hyp light-independent effects regarding reactive oxygen species (ROS). We summarize work from our laboratories and that of others to reveal an intricate network of the Hyp light-independent effects. We propose a schematic model of pro- and anti-apoptotic protein dynamics between cell organelles due to Hyp presence without illumination. Based on our model, Hyp can be explored as an adjuvant therapeutic drug in combination with chemo- or radiation cancer therapy. PMID:27754424

  17. Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria

    PubMed Central

    Sperandio, Felipe F; Huang, Ying-Ying; Hamblin, Michael R

    2013-01-01

    Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT may have advantages over traditional antibiotic therapy. PDT is a non-thermal photochemical reaction that involves the simultaneous presence of visible light, oxygen and a dye or photosensitizer (PS). Several PS have been studied for their ability to bind to bacteria and efficiently generate reactive oxygen species (ROS) upon photostimulation. ROS are formed through type I or II mechanisms and may inactivate several classes of microbial cells including Gram-negative bacteria such as Pseudomonas aeruginosa, which are typically characterized by an impermeable outer cell membrane that contains endotoxins and blocks antibiotics, dyes, and detergents, protecting the sensitive inner membrane and cell wall. This review covers significant peer-reviewed articles together with US and World patents that were filed within the past few years and that relate to the eradication of Gram-negative bacteria via PDI or PDT. It is organized mainly according to the nature of the PS involved and includes natural or synthetic food dyes; cationic dyes such as methylene blue and toluidine blue; tetrapyrrole derivatives such as phthalocyanines, chlorins, porphyrins, chlorophyll and bacteriochlorophyll derivatives; functionalized fullerenes; nanoparticles combined with different PS; other formulations designed to target PS to bacteria; photoactive materials and surfaces; conjugates between PS and polycationic polymers or antibodies; and permeabilizing agents such as EDTA, PMNP and CaCl2. The present review also covers the different laboratory animal models normally used to treat Gram-negative bacterial infections with antimicrobial PDT. PMID

  18. Photodynamic Therapy for Head and Neck Dysplasia and Cancer

    PubMed Central

    Rigual, Nestor R.; Thankappan, Krishnakumar; Cooper, Michele; Sullivan, Maureen A.; Dougherty, Thomas; Popat, Saurin R.; Loree, Thom R.; Biel, Merrill A.; Henderson, Barbara

    2009-01-01

    Objective To determine the response of dysplasia, carcinoma in situ (CIS), and T1 carcinoma of the oral cavity and larynx to photodynamic therapy with porfimer sodium. Design Prospective trial. Setting A National Cancer Institute–designated cancer institute. Patients Patients with primary or recurrent moderate to severe oral or laryngeal dysplasia, CIS, or T1N0 carcinoma. Intervention Porfimer sodium, 2 mg/kg of body weight, was injected intravenously 48 hours before treatment. Light at 630 nm for photosensitizer activation was delivered from an argon laser or diode laser using lens or cylindrical diffuser fibers. The light dose was 50 J/cm2 for dysplasia and CIS and 75 J/cm2 for carcinoma. Main Outcome Measures Response was evaluated at 1 week and at 1 month and then at 3-month intervals thereafter. Response options were complete (CR), partial (PR), and no (NR) response. Posttreatment biopsies were performed in all patients with persistent and recurrent visible lesions. Results Thirty patients were enrolled, and 26 were evaluable. Mean follow-up was 15 months (range, 7–52 months). Twenty-four patients had a CR, 1 had a PR, and 1 had NR. Three patients with oral dysplasia with an initial CR experienced recurrence in the treatment field. All the patients with NR, a PR, or recurrence after an initial CR underwent salvage treatment. Temporary morbidities included edema, pain, hoarseness, and skin phototoxicity. Conclusion Photodynamic therapy with porfimer sodium is an effective treatment alternative, with no permanent sequelae, for oral and laryngeal dysplasia and early carcinoma. PMID:19687399

  19. Photodynamic damage of glial cells in crayfish ventral nerve cord

    NASA Astrophysics Data System (ADS)

    Kolosov, M. S.; Duz, E.; Uzdensky, A. B.

    2010-10-01

    Photodynamic therapy (PDT) is a promising method for treatment of brain tumors, the most of which are of glial origin. In the present work we studied PDT-mediated injury of glial cells in nerve tissue, specifically, in abdominal connectives in the crayfish ventral nerve cord. The preparation was photosensitized with alumophthalocyanine Photosens and irradiated 30 min with the diode laser (670 nm, 0.1 or 0.15 W/cm2). After following incubation in the darkness during 1- 10 hours it was fluorochromed with Hoechst 33342 and propidium iodide to reveal nuclei of living, necrotic and apoptotic cells. The chain-like location of the glial nuclei allowed visualization of those enveloping giant axons and blood vessels. The level of glial necrosis in control preparations was about 2-5 %. Apoptosis was not observed in control preparations. PDT significantly increased necrosis of glial cells to 52 or 67 % just after irradiation with 0.1 or 0.15 W/cm2, respectively. Apoptosis of glial cells was observed only at 10 hours after light exposure. Upper layers of the glial envelope of the connectives were injured stronger comparing to deep ones: the level of glial necrosis decreased from 100 to 30 % upon moving from the connective surface to the plane of the giant axon inside the connective. Survival of glial cells was also high in the vicinity of blood vessels. One can suggest that giant axons and blood vessels protect neighboring glial cells from photodynamic damage. The mechanism of such protective action remains to be elucidated.

  20. Photodynamic damage of glial cells in crayfish ventral nerve cord

    NASA Astrophysics Data System (ADS)

    Kolosov, M. S.; Duz, E.; Uzdensky, A. B.

    2011-03-01

    Photodynamic therapy (PDT) is a promising method for treatment of brain tumors, the most of which are of glial origin. In the present work we studied PDT-mediated injury of glial cells in nerve tissue, specifically, in abdominal connectives in the crayfish ventral nerve cord. The preparation was photosensitized with alumophthalocyanine Photosens and irradiated 30 min with the diode laser (670 nm, 0.1 or 0.15 W/cm2). After following incubation in the darkness during 1- 10 hours it was fluorochromed with Hoechst 33342 and propidium iodide to reveal nuclei of living, necrotic and apoptotic cells. The chain-like location of the glial nuclei allowed visualization of those enveloping giant axons and blood vessels. The level of glial necrosis in control preparations was about 2-5 %. Apoptosis was not observed in control preparations. PDT significantly increased necrosis of glial cells to 52 or 67 % just after irradiation with 0.1 or 0.15 W/cm2, respectively. Apoptosis of glial cells was observed only at 10 hours after light exposure. Upper layers of the glial envelope of the connectives were injured stronger comparing to deep ones: the level of glial necrosis decreased from 100 to 30 % upon moving from the connective surface to the plane of the giant axon inside the connective. Survival of glial cells was also high in the vicinity of blood vessels. One can suggest that giant axons and blood vessels protect neighboring glial cells from photodynamic damage. The mechanism of such protective action remains to be elucidated.

  1. Decontamination of dental implant surfaces by means of photodynamic therapy.

    PubMed

    Marotti, Juliana; Tortamano, Pedro; Cai, Silvana; Ribeiro, Martha Simões; Franco, João Eduardo Miranda; de Campos, Tomie Toyota

    2013-01-01

    Several implant surface debridement methods have been reported for the treatment of peri-implantitis, however, some of them can damage the implant surface or promote bacterial resistance. Photodynamic therapy (PDT) is a new treatment option for peri-implantitis. The aim of this in vitro study was to analyze implant surface decontamination by means of PDT. Sixty implants were equally distributed (n = 10) into four groups and two subgroups. In group G1 there was no decontamination, while in G2 decontamination was performed with chlorhexidine. G3 (PDT - laser + dye) and G4 (laser, without dye) were divided into two subgroups each; with PDT performed for 3 min in G3a and G4a, and for 5 min in G3b and G4b. After 5 min in contact with methylene blue dye (G3), the implants were irradiated (G3 and G4) with a low-level laser (GaAlAs, 660 nm, 30 mW) for 3 or 5 min (7.2 and 12 J). After the dilutions, culture media were kept in an anaerobic atmosphere for 1 week, and then colony forming units were counted. There was a significant difference (p < 0.001) between G1 and the other groups, and between G4 in comparison with G2 and G3. Better decontamination was obtained in G2 and G3, with no statistically significant difference between them. The results of this study suggest that photodynamic therapy can be considered an efficient method for reducing bacteria on implant surfaces, whereas laser irradiation without dye was less efficient than PDT.

  2. Photodynamic therapy of bacterial and fungal biofilm infections.

    PubMed

    Biel, Merrill A

    2010-01-01

    Biofilms have been found to be involved in a wide variety of microbial infections in the body, by one estimate 80% of all infections. Infectious processes in which biofilms have been implicated include common problems such as urinary tract infections, catheter infections, middle-ear infections, sinusitis, formation of dental plaque, gingivitis, coating contact lenses, endocarditis, infections in cystic fibrosis, and infections of permanent indwelling devices such as joint prostheses and heart valves. Bacteria living in a biofilm usually have significantly different properties from free-floating bacteria of the same species, as the dense and protected environment of the film allows them to cooperate and interact in various ways. One benefit of this environment is increased resistance to detergents and antibiotics, as the dense extracellular matrix and the outer layer of cells protect the interior of the community. In some cases antibiotic resistance can be increased 1000-fold. Also, the biofilm bacteria excrete toxins that reversibly block important processes such as translation and protecting the cell from bactericidal antibiotics that are ineffective against inactive targets. In the head and neck area, biofilms are a major etiologic factor in periodontitis, wound infections, oral candidiasis, and sinus and ear infections. For the past several decades, photodynamic treatment has been reported in the literature to be effective in eradicating various microorganisms using different photosensitizers, different wavelengths of light, and different light sources. PDT has been further studied to demonstrate its effectiveness for the eradication of both Gram-negative and Gram-positive antibiotic-resistant bacteria. This chapter will focus on the use of PDT in the treatment of antibiotic-resistant biofilms, antibiotic-resistant wound infections, and azole-resistant oral candidiasis using methylene blue-based photodynamic therapy.

  3. System for integrated interstitial photodynamic therapy and dosimetric monitoring

    NASA Astrophysics Data System (ADS)

    Johansson, Ann; Soto Thompson, Marcelo; Johansson, Thomas; Bendsoe, Niels; Svanberg, Katarina; Svanberg, Sune; Andersson-Engels, Stefan

    2005-04-01

    Photodynamic therapy for the treatment of cancer relies on the presence of light, sensitizer and oxygen. By monitoring these three parameters during the treatment a better understanding and treatment control could possibly be achieved. Here we present data from in vivo treatments of solid skin tumors using an instrument for interstitial photodynamic therapy with integrated dosimetric monitoring. By using intra-tumoral ALA-administration and interstitial light delivery solid tumors are targeted. The same fibers are used for measuring the fluence rate at the treatment wavelength, the sensitizer fluorescence and the local blood oxygen saturation during the treatment. The data presented is based on 10 treatments in 8 patients with thick basal cell carcinomas. The fluence rate measurements at 635 nm indicate a major treatment induced absorption increase, leading to a limited light penetration at the treatment wavelength. This leads to a far from optimal treatment since the absorption increase prevents peripheral tumor regions from being fully treated. An interactive treatment has been implemented assisting the physician in delivering the correct light dose. The absorption increase can be compensated for by either prolonging the treatment time or increasing the output power of each individual treatment fiber. The other parameters of importance, i.e. the sensitizer fluorescence at 705 nm and the local blood oxygen saturation, are monitored in order to get an estimate of the amount of photobleaching and oxygen consumption. Based on the oxygen saturation signal, a fractionized irradiation can be introduced in order to allow for a re-oxygenation of the tissue.

  4. Insight into 2α-Chloro-2′(2′,6′)-(Di)Halogenopicropodophyllotoxins Reacting with Carboxylic Acids Mediated by BF3·Et2O

    PubMed Central

    Fan, Lingling; Zhi, Xiaoyan; Che, Zhiping; Xu, Hui

    2015-01-01

    Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2′(2′,6′)-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5–31 h, the resulting compounds were all transformed into the unusual C-ring aromatization products. Additionally, it demonstrated that BF3·Et2O and reaction temperature were the important factors for C-ring aromatization, and AlCl3 could be substituted for BF3·Et2O as a lewis acid for C-ring aromatization. Halogenation of E-ring of 2β-chloropodophyllotoxins with NCS or NBS also led to the same C-ring aromatization compounds. Especially compounds 5c, 6g and 7b exhibited insecticidal activity equal to that of toosendanin. PMID:26573374

  5. Meta-Analysis of Global Transcriptomics Suggests that Conserved Genetic Pathways are Responsible for Quercetin and Tannic Acid Mediated Longevity in C. elegans

    PubMed Central

    Pietsch, Kerstin; Saul, Nadine; Swain, Suresh C.; Menzel, Ralph; Steinberg, Christian E. W.; Stürzenbaum, Stephen R.

    2012-01-01

    Recent research has highlighted that the polyphenols Quercetin and Tannic acid are capable of extending the lifespan of Caenorhabditis elegans. To gain a deep understanding of the underlying molecular genetics, we analyzed the global transcriptional patterns of nematodes exposed to three concentrations of Quercetin or Tannic acid, respectively. By means of an intricate meta-analysis it was possible to compare the transcriptomes of polyphenol exposure to recently published datasets derived from (i) longevity mutants or (ii) infection. This detailed comparative in silico analysis facilitated the identification of compound specific and overlapping transcriptional profiles and allowed the prediction of putative mechanistic models of Quercetin and Tannic acid mediated longevity. Lifespan extension due to Quercetin was predominantly driven by the metabolome, TGF-beta signaling, Insulin-like signaling, and the p38 MAPK pathway and Tannic acid’s impact involved, in part, the amino acid metabolism and was modulated by the TGF-beta and the p38 MAPK pathways. DAF-12, which integrates TGF-beta and Insulin-like downstream signaling, and genetic players of the p38 MAPK pathway therefore seem to be crucial regulators for both polyphenols. Taken together, this study underlines how meta-analyses can provide an insight of molecular events that go beyond the traditional categorization into gene ontology-terms and Kyoto encyclopedia of genes and genomes-pathways. It also supports the call to expand the generation of comparative and integrative databases, an effort that is currently still in its infancy. PMID:22493606

  6. DJ-1 plays an important role in caffeic acid-mediated protection of the gastrointestinal mucosa against ketoprofen-induced oxidative damage.

    PubMed

    Cheng, Yu-Ting; Ho, Cheng-Ying; Jhang, Jhih-Jia; Lu, Chi-Cheng; Yen, Gow-Chin

    2014-10-01

    Ketoprofen is widely used to alleviate pain and inflammation in clinical medicine; however, this drug may cause oxidative stress and lead to gastrointestinal (GI) ulcers. We previously reported that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in protecting cells against reactive oxygen species, and it facilitates the prevention of ketoprofen-induced GI mucosal ulcers. Recent reports suggested that Nrf2 becomes unstable in the absence of DJ-1/PARK7, attenuating the activity of Nrf2-regulated downstream antioxidant enzymes. Thus, increasing Nrf2 translocation by DJ-1 may represent a novel means for GI protection. In vitro, caffeic acid increases the nuclear/cytosolic Nrf2 ratio and the mRNA expression of the downstream antioxidant enzymes, ϒ-glutamyl cysteine synthetase, glutathione peroxidase, glutathione reductase, and heme oxygenase-1, by activating the JNK/p38 pathway in Int-407 cells. Moreover, knockdown of DJ-1 also reversed caffeic acid-induced nuclear Nrf2 protein expression in a JNK/p38-dependent manner. Our results also indicated that treatment of Sprague-Dawley rats with caffeic acid prior to the administration of ketoprofen inhibited oxidative damage and reversed the inhibitory effects of ketoprofen on the antioxidant system and DJ-1 protein expression in the GI mucosa. Our observations suggest that DJ-1 plays an important role in caffeic acid-mediated protection against ketoprofen-induced oxidative damage in the GI mucosa.

  7. Quinones as photosensitizer for photodynamic therapy: ROS generation, mechanism and detection methods.

    PubMed

    Rajendran, M

    2016-03-01

    Photodynamic therapy (PDT) is based on the dye-sensitized photooxidation of biological matter in the target tissue, and utilizes light activated drugs for the treatment of a wide variety of malignancies. Quinones and porphyrins moiety are available naturally and involved in the biological process. Quinone metabolites perform a variety of key functions in plants which includes pathogen protection, oxidative phosphorylation, and redox signaling. Quinones and porphyrin are biologically accessible and will not create any allergic effects. In the field of photodynamic therapy, porphyrin derivatives are widely used, because it absorb in the photodynamic therapy window region (600-900 nm). Hence, researchers synthesize drugs based on porphyrin structure. Benzoquinone and its simple polycyclic derivatives such as naphthaquinone and anthraquinones absorb at lower wavelength region (300-400 nm), which is lower than porphyrin. Hence they are not involved in PDT studies. However, higher polycyclic quinones absorb in the photodynamic therapy window region (600-900 nm), because of its conjugation and can be used as PDT agents. Redox cycling has been proposed as a possible mechanism of action for many quinone species. Quinones are involved in the photodynamic as well as enzymatic generation of reactive oxygen species (ROS). Generations of ROS may be measured by optical, phosphorescence and EPR methods. The photodynamically generated ROS are also involved in many biological events. The photo-induced DNA cleavage by quinones correlates with the ROS generating efficiencies of the quinones. In this review basic reactions involving photodynamic generation of ROS by quinones and their biological applications were discussed.

  8. Photodynamic therapy in the treatment of chronic periodontitis: a systematic review and meta-analysis.

    PubMed

    Sgolastra, Fabrizio; Petrucci, Ambra; Gatto, Roberto; Marzo, Giuseppe; Monaco, Annalisa

    2013-02-01

    This meta-analysis was conducted to investigate the efficacy and safety of antimicrobial photodynamic therapy used alone or adjunctive to scaling root planing in patients with chronic periodontitis. The meta-analysis was conducted according to the QUOROM statement and recommendations of the Cochrane Collaboration. An extensive literature search was performed on seven databases, followed by a manual search. Weighted mean differences and 95% confidence intervals were calculated for clinical attachment level, probing depth and gingival recession. The I(2) test was used for inter-study heterogeneity; visual asymmetry inspection of the funnel plot, Egger's regression test and the trim-and-fill method were used to investigate publication bias. At 3 months, significant differences in clinical attachment level (p = 0.006) and probing depth reduction (p = 0.02) were observed for scaling root planing with antimicrobial photodynamic therapy, while no significant differences were retrieved for antimicrobial photodynamic therapy used alone; at 6 months no significant differences were observed for any investigated outcome. Neither heterogeneity nor publication bias was detected. The use of antimicrobial photodynamic therapy adjunctive to conventional treatment provides short-term benefits, but microbiological outcomes are contradictory. There is no evidence of effectiveness for the use of antimicrobial photodynamic therapy as alternative to scaling root planing. Long-term randomized controlled clinical trials reporting data on microbiological changes and costs are needed to support the long-term efficacy of adjunctive antimicrobial photodynamic therapy and the reliability of antimicrobial photodynamic therapy as alternative treatment to scaling root planing.

  9. Quinones as photosensitizer for photodynamic therapy: ROS generation, mechanism and detection methods.

    PubMed

    Rajendran, M

    2016-03-01

    Photodynamic therapy (PDT) is based on the dye-sensitized photooxidation of biological matter in the target tissue, and utilizes light activated drugs for the treatment of a wide variety of malignancies. Quinones and porphyrins moiety are available naturally and involved in the biological process. Quinone metabolites perform a variety of key functions in plants which includes pathogen protection, oxidative phosphorylation, and redox signaling. Quinones and porphyrin are biologically accessible and will not create any allergic effects. In the field of photodynamic therapy, porphyrin derivatives are widely used, because it absorb in the photodynamic therapy window region (600-900 nm). Hence, researchers synthesize drugs based on porphyrin structure. Benzoquinone and its simple polycyclic derivatives such as naphthaquinone and anthraquinones absorb at lower wavelength region (300-400 nm), which is lower than porphyrin. Hence they are not involved in PDT studies. However, higher polycyclic quinones absorb in the photodynamic therapy window region (600-900 nm), because of its conjugation and can be used as PDT agents. Redox cycling has been proposed as a possible mechanism of action for many quinone species. Quinones are involved in the photodynamic as well as enzymatic generation of reactive oxygen species (ROS). Generations of ROS may be measured by optical, phosphorescence and EPR methods. The photodynamically generated ROS are also involved in many biological events. The photo-induced DNA cleavage by quinones correlates with the ROS generating efficiencies of the quinones. In this review basic reactions involving photodynamic generation of ROS by quinones and their biological applications were discussed. PMID:26241780

  10. Photosensitizer-loaded gold nanorods for near infrared photodynamic and photothermal cancer therapy.

    PubMed

    Bhana, Saheel; O'Connor, Ryan; Johnson, Jermaine; Ziebarth, Jesse D; Henderson, Luke; Huang, Xiaohua

    2016-05-01

    Despite the advancement of photodynamic therapy and photothermal therapy, the ability to form compact nanocomplex for combined photodynamic and photothermal cancer therapy under a single near infrared irradiation remains limited. In this work, we prepared an integrated sub-100 nm nanosystem for simultaneous near infrared photodynamic and photothermal cancer therapy. The nanosystem was formed by adsorption of silicon 2,3-naphthalocyanine dihydroxide onto gold nanorod followed by covalent stabilization with alkylthiol linked polyethylene glycol. The effects of alkylthiol chain length on drug loading, release and cell killing efficacy were examined using 6-mercaptohexanoic acid, 11-mercaptoundecanoic acid and 16-mercaptohexadecanoic acid. We found that the loading efficiency of silicon 2,3-naphthalocyanine dihydroxide increased and the release rate decreased with the increase of the alkylthiol chain length. We demonstrated that the combined near infrared photodynamic and photothermal therapy using the silicon 2,3-naphthalocyanine dihydroxide-loaded gold nanorods exhibit superior efficacy in cancer cell destruction as compared to photodynamic therapy and photothermal therapy alone. The nanocomplex stabilized with 16-mercaptohexadecanoic acid linked polyethylene glycol provided highest cell killing efficiency as compared to those stabilized with the other two stabilizers under low drug dose. This new nanosystem has potential to completely eradicate tumors via noninvasive phototherapy, preventing tumor reoccurrence and metastasis.

  11. Prevention of Distant Lung Metastasis After Photodynamic Therapy Application in a Breast Cancer Tumor Model.

    PubMed

    Longo, João Paulo Figueiró; Muehlmann, Luis Alexandre; Miranda-Vilela, Ana Luisa; Portilho, Flávia Arruda; de Souza, Ludmilla Regina; Silva, Jaqueline Rodrigues; Lacava, Zulmira Guerrero Marques; Bocca, Anamelia Lorenzetti; Chaves, Sacha Braun; Azevedo, Ricardo Bentes

    2016-04-01

    The objective of this study was to investigate the activity of photodynamic therapy mediated by aluminum-chlorophthalocyanine contained in a polymeric nanostructured carrier composed by methyl vinyl ether-co-maleic anhydride (PVM/MA) against local subcutaneous breast cancer tumors and its effects against distant metastasis in a mouse tumor model. In our results, we observed a decrease in breast cancer tumor growth, prevention of distant lung metastases, and a significant increased survival in mice treated with photodynamic therapy. In addition to these results, we observed that tumor-bearing mice without treatment developed a significant extension of liver hematopoiesis that was significantly reduced in mice treated with photodynamic therapy. We hypothesized and showed that this reduction in (1) metastasis and (2) liver hematopoiesis may be related to the systemic activity of immature hematopoietic cells, specifically the myeloid-derived suppressor cells, which were suppressed in mice treated with photodynamic therapy. These cells produce a tolerogenic tumor environment that protects tumor tissues from immunological surveillance. Therefore, we suggest that photodynamic therapy could be employed in combination with other conventional therapies; such as surgery and radiotherapy, to improve the overall survival of patients diagnosed with breast cancer, as observed in our experimental resuIts.

  12. Polymeric photosensitizer-embedded self-expanding metal stent for repeatable endoscopic photodynamic therapy of cholangiocarcinoma.

    PubMed

    Bae, Byoung-chan; Yang, Su-Geun; Jeong, Seok; Lee, Don Haeng; Na, Kun; Kim, Joon Mee; Costamagna, Guido; Kozarek, Richard A; Isayama, Hiroyuki; Deviere, Jacques; Seo, Dong Wan; Nageshwar Reddy, D

    2014-10-01

    Photodynamic therapy (PDT) is a new therapeutic approach for the palliative treatment of malignant bile duct obstruction. In this study, we designed photosensitizer-embedded self-expanding nonvascular metal stent (PDT-stent) which allows repeatable photodynamic treatment of cholangiocarcinoma without systemic injection of photosensitizer. Polymeric photosensitizer (pullulan acetate-conjugated pheophorbide A; PPA) was incorporated in self-expanding nonvascular metal stent. Residence of PPA in the stent was estimated in buffer solution and subcutaneous implantation on mouse. Photodynamic activity of PDT-stent was evaluated through laserexposure on stent-layered tumor cell lines, HCT-116 tumor-xenograft mouse models and endoscopic intervention of PDT-stent on bile duct of mini pigs. Photo-fluorescence imaging of the PDT-stent demonstrated homogeneous embedding of polymeric Pheo-A (PPA) on stent membrane. PDT-stent sustained its photodynamic activities at least for 2 month. And which implies repeatable endoscopic PDT is possible after stent emplacement. The PDT-stent after light exposure successfully generated cytotoxic singlet oxygen in the surrounding tissues, inducing apoptotic degradation of tumor cells and regression of xenograft tumors on mouse models. Endoscopic biliary in-stent photodynamic treatments on minipigs also suggested the potential efficacy of PDT-stent on cholangiocarcinoma. In vivo and in vitro studies revealed our PDT-stent, allows repeatable endoscopic biliary PDT, has the potential for the combination therapy (stent plus PDT) of cholangiocarcinoma.

  13. Prevention of Distant Lung Metastasis After Photodynamic Therapy Application in a Breast Cancer Tumor Model.

    PubMed

    Longo, João Paulo Figueiró; Muehlmann, Luis Alexandre; Miranda-Vilela, Ana Luisa; Portilho, Flávia Arruda; de Souza, Ludmilla Regina; Silva, Jaqueline Rodrigues; Lacava, Zulmira Guerrero Marques; Bocca, Anamelia Lorenzetti; Chaves, Sacha Braun; Azevedo, Ricardo Bentes

    2016-04-01

    The objective of this study was to investigate the activity of photodynamic therapy mediated by aluminum-chlorophthalocyanine contained in a polymeric nanostructured carrier composed by methyl vinyl ether-co-maleic anhydride (PVM/MA) against local subcutaneous breast cancer tumors and its effects against distant metastasis in a mouse tumor model. In our results, we observed a decrease in breast cancer tumor growth, prevention of distant lung metastases, and a significant increased survival in mice treated with photodynamic therapy. In addition to these results, we observed that tumor-bearing mice without treatment developed a significant extension of liver hematopoiesis that was significantly reduced in mice treated with photodynamic therapy. We hypothesized and showed that this reduction in (1) metastasis and (2) liver hematopoiesis may be related to the systemic activity of immature hematopoietic cells, specifically the myeloid-derived suppressor cells, which were suppressed in mice treated with photodynamic therapy. These cells produce a tolerogenic tumor environment that protects tumor tissues from immunological surveillance. Therefore, we suggest that photodynamic therapy could be employed in combination with other conventional therapies; such as surgery and radiotherapy, to improve the overall survival of patients diagnosed with breast cancer, as observed in our experimental resuIts. PMID:27301195

  14. Specific inhibition of the ABCG2 transporter could improve the efficacy of photodynamic therapy.

    PubMed

    Bebes, Attila; Nagy, Tünde; Bata-Csörgo, Zsuzsanna; Kemény, Lajos; Dobozy, Attila; Széll, Márta

    2011-11-01

    Photodynamic therapy is based on the selective accumulation of a photosensitizer in tumors, followed by destruction of the target tissue by a light source. Protoporphyrin IX, a well-known photosensitizer, was recently reported as an endogenous substrate for the multidrug transporter ABCG2. We investigated the role of ABCG2 protein in the porphyrin extrusion ability of keratinocytes, with regard to the impact of the specific inhibition of ABCG2 by a non-toxic fumitremorgin C analog, Ko-134, on photodynamic therapy efficacy. We studied the level of porphyrin accumulation in response to delta-aminolevulinic acid pretreatment in proliferating and highly differentiated HaCaT keratinocytes. An in vitro model of photodynamic therapy on HaCaT cells was established with a therapeutically approved narrow-bandwidth red-light source. The porphyrin extrusion ability of HaCaT cells proved to correlate with their ABCG2 expression which was higher in proliferating cells than in differentiated cells. Moreover, the specific inhibition of ABCG2 by Ko-134 enhanced the sensitivity of keratinocytes to photodynamic therapy in vitro. These results suggest that ABCG2 may serve as a target molecule via which to improve the photodynamic therapy of skin lesions: its inhibition by the non-toxic Ko-134 is a promising therapeutic modality.

  15. [Photodynamic therapy in combined treatment of stage III non-small cell lung carcinoma].

    PubMed

    Akopov, A L; Rusanov, A A; Molodtsova, V P; Chistiakov, I V; Kazakov, N V; Urtenova, M A; Rait, Makhmud; Papaian, G V

    2013-01-01

    The aim of the study was to evaluate the effectiveness of combined treatment of locally advanced lung cancer with the use of neoadjuvant chemotherapy and surgery with the use of pre- and intraoperative photodynamic therapy. 20 patients with IIIa (n=7) and IIIb (n=13) stage of non-small cell lung carcinoma were included. At the time of diagnosis the surgical treatment was decided to abstain because of the trachea invasion in 9 patients, wide mediastinal invasion in 2 patients and contralateral mediastinal lymph nodes metastases in 2 patients; pneumonectomy was not possible due to the poor respiratory function in 7 patients. Neoadjuvant therapy included 3 courses of chemotherapy and endobronchial photodynamic therapy. During the operation, along with the lung resection (pneumonectomy - 15, lobectomy - 5), photodynamic therapy of the resection margins were carried out. No adjuvant treatment was done. Preoperative treatment led to partial regress of the disease in all cases; the goal of surgery was the complete tumor removal. No complications of the photodynamic therapy were observed. 18 surgical interventions were radical and two non-complete microscopically (R1). Postoperative morbidity was 20%, one patient died due to massive gastrointestinal bleeding. The average follow-up period was 18 months: 19 patients were alive, of them 18 with no signs of the disease recurrence. The first experience of the combined use of neoadjuvant chemotherapy and surgery with pre- and intraoperative photodynamic therapy demonstrates safety and efficacy of the suggested treatment tactics. PMID:23612332

  16. TMV-Cg Coat Protein stabilizes DELLA proteins and in turn negatively modulates salicylic acid-mediated defense pathway during Arabidopsis thaliana viral infection

    PubMed Central

    2014-01-01

    Background Plant viral infections disturb defense regulatory networks during tissue invasion. Emerging evidence demonstrates that a significant proportion of these alterations are mediated by hormone imbalances. Although the DELLA proteins have been reported to be central players in hormone cross-talk, their role in the modulation of hormone signaling during virus infections remains unknown. Results This work revealed that TMV-Cg coat protein (CgCP) suppresses the salicylic acid (SA) signaling pathway without altering defense hormone SA or jasmonic acid (JA) levels in Arabidopsis thaliana. Furthermore, it was observed that the expression of CgCP reduces plant growth and delays the timing of floral transition. Quantitative RT-qPCR analysis of DELLA target genes showed that CgCP alters relative expression of several target genes, indicating that the DELLA proteins mediate transcriptional changes produced by CgCP expression. Analyses by fluorescence confocal microscopy showed that CgCP stabilizes DELLA proteins accumulation in the presence of gibberellic acid (GA) and that the DELLA proteins are also stabilized during TMV-Cg virus infections. Moreover, DELLA proteins negatively modulated defense transcript profiles during TMV-Cg infection. As a result, TMV-Cg accumulation was significantly reduced in the quadruple-DELLA mutant Arabidopsis plants compared to wild type plants. Conclusions Taken together, these results demonstrate that CgCP negatively regulates the salicylic acid-mediated defense pathway by stabilizing the DELLA proteins during Arabidopsis thaliana viral infection, suggesting that CgCP alters the stability of DELLAs as a mechanism of negative modulation of antiviral defense responses. PMID:25084837

  17. Photodynamic therapy of non-melanoma skin cancers

    NASA Astrophysics Data System (ADS)

    Ikram, M.; Khan, R. U.; Firdous, S.; Atif, M.; Nawaz, M.

    2011-02-01

    In this prospective study duly approved from Institutional Ethics Review Committee for research in medicine, PAEC General Hospital Islamabad, Pakistan, we investigate the efficacy, safety and tolerability along with cosmetic outcome of topical 5-aminolaevulinic acid photodynamic therapy for superficial nonmelanoma skin cancers (NMSCs) and their precursors. Patients with Histological diagnosis of NMSCs and their precursors were assessed for PDT, after photographic documentation of the lesions and written consent, underwent two (2) sessions of PDT in one month (4 weeks) according to standard protocol. A freshly prepared 20% 5-ALA in Unguentum base was applied under occlusive dressing for 4-6 h as Drug Light Interval (DLI) and irradiated with light of 630 nm wavelength from a diode laser at standard dose of 90 J/cm2. Approximately 11% patients reported pain during treatment which was managed in different simple ways. In our study we regularly followed up the patients for gross as well as histopathological response and recurrence free periods during median follow-up of 24 months. Regarding Basal cell carcinomas complete response was observed in 86.2% (25/29), partial response in 10.3% (3/29) and recurrence during first year in 3.5% (1/29) lesions. All the lesions which showed partial response or recurrence were nBCCs. Regarding Actinic Keratosis complete response was observed in 95.3% (20/21), partial response in 4.7% (1/21) while Bowen's disease showed 100% (2/2) results. 81.8% (9/11) Squamous Cell Carcinomas showed complete, 9% (1/11) partial response and 9% (1/11) presented with recurrence after 3 months. We observed excellent and good cosmetic results along with tumor clearance in our study. Treatment sessions were well tolerated with high level of patient's satisfaction and only minor side effects of pain during treatment sessions and inflammatory changes post photodynamic therapy were observed. We concluded that 5-ALA PDT is an effective and safe emerging

  18. Using fluorescence to augment the efficacy of photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Dickey, Dwayne J.; Liu, Weiyang; Naicker, Selvaraj; Woo, Thomas; Moore, Ronald B.; Tulip, John

    2006-09-01

    Photodynamic Therapy (PDT) is a relatively novel oncological treatment modality, in which a patient is administered a photosensitive drug, called a photosensitizer. After allowing sufficient time for biodistribution, the cancerous area is irradiated with light of the appropriate wavelength, activating the photosensitizer to produce highly reactive singlet oxygen, which produces a highly localized cell kill. The efficacy of PDT is determined by a) the intensity of the light b) the local concentration of the photosensitizer, and c) the availability of oxygen. However, with the clinical application of PDT, the patient is simply administered a body mass dependent quantity of photosensitizer, and then the target area is administered a prescribed amount of radiant energy (joules per cubic centimetre). For treatment of superficial malignancies, PDT has many successes; however, interstitial PDT (PDT of solid, internal malignancies) has inconsistent outcomes mostly due to the inability to predict, calculate or measure the variables that affect PDT: the radiation dose, oxygen concentration, and the photosensitizer concentration. We have developed sophisticated methods to determine the behaviour of light in homogeneous biological tissues. Tissue oxygen levels can be replenished by fractionating the light dose - allowing areas of your target tissue to go through a "dark" cycle during PDT. However, to date, there has not been an accurate method of determining tissue photosensitizer concentrations in-vivo. We are researching the efficacy of a novel hypocrellin derivative, SL-052. Like other photosensitizers available, SL-052 shows strong therapeutic photodynamic activity when irradiated by 635 nm light. Like most photosensitizers, SL-052 exhibits fluorescent activity, but SL-052 also shows strong fluorescent emission at 725nm when excited by 635 nm. The intensity of the fluorescent emission can been correlated with the local concentration of the photosenstizer. However, many

  19. Photodynamic Therapy As a Promising Method Used in the Treatment of Oral Diseases.

    PubMed

    Prażmo, Ewa J; Kwaśny, Mirosław; Łapiński, Mariusz; Mielczarek, Agnieszka

    2016-01-01

    Photodynamic therapy (PDT) consists of three elements: photosensitizer, light and oxygen. The photosensitizer has the property of selective accumulation in abnormal or infected tissues without causing any damage to the healthy cells. This innovative therapeutic method has already been successfully adapted in many fields of medicine, e.g. dermatology, gynecology, urology and cancer therapy. Dentistry is also beginning to incorporate photodisinfection for treatment of the oral cavity. The antibacterial and fungicidal properties of the photosensitizer have been used to achieve better results in root canal treatment, periodontal therapy and the eradication of candidiasis in prosthodontics. The aim of this article is to discuss the effectiveness of photodynamic methods in the diagnosis and therapy of selected oral diseases. Scientific data and published papers regarding the antibacterial properties of PDT will be subjected to analysis. Photodynamic therapy will be discussed as an alternative treatment protocol in oncology, endodontics, periodontology and other fields of dentistry.

  20. Ratiometric Biosensor for Aggregation-Induced Emission-Guided Precise Photodynamic Therapy.

    PubMed

    Han, Kai; Wang, Shi-Bo; Lei, Qi; Zhu, Jing-Yi; Zhang, Xian-Zheng

    2015-10-27

    Photodynamic therapy faces the barrier of choosing the appropriate irradiation region and time. In this paper, a matrix metalloproteinase-2 (MMP-2) responsive ratiometric biosensor was designed and synthesized for aggregation-induced emission (AIE)-guided precise photodynamic therapy. It was found that the biosensor presented the MMP-2 responsive AIE behavior. Most importantly, it could accurately differentiate the tumor cells from the healthy cells by the fluorescence ratio between freed tetraphenylethylene and protoporphyrin IX (PpIX, internal reference). In vivo study demonstrated that the biosensor could preferentially accumulate in the tumor tissue with a relative long blood retention time. Note that the intrinsic fluorescence of PpIX and MMP-2-triggered AIE fluorescence provided a real-time feedback which guided precise photodynamic therapy in vivo efficiently. This strategy demonstrated here opens a window in the precise medicine, especially for phototherapy.

  1. Photodynamic Therapy As a Promising Method Used in the Treatment of Oral Diseases.

    PubMed

    Prażmo, Ewa J; Kwaśny, Mirosław; Łapiński, Mariusz; Mielczarek, Agnieszka

    2016-01-01

    Photodynamic therapy (PDT) consists of three elements: photosensitizer, light and oxygen. The photosensitizer has the property of selective accumulation in abnormal or infected tissues without causing any damage to the healthy cells. This innovative therapeutic method has already been successfully adapted in many fields of medicine, e.g. dermatology, gynecology, urology and cancer therapy. Dentistry is also beginning to incorporate photodisinfection for treatment of the oral cavity. The antibacterial and fungicidal properties of the photosensitizer have been used to achieve better results in root canal treatment, periodontal therapy and the eradication of candidiasis in prosthodontics. The aim of this article is to discuss the effectiveness of photodynamic methods in the diagnosis and therapy of selected oral diseases. Scientific data and published papers regarding the antibacterial properties of PDT will be subjected to analysis. Photodynamic therapy will be discussed as an alternative treatment protocol in oncology, endodontics, periodontology and other fields of dentistry. PMID:27629857

  2. Photodynamic inactivation of microorganisms which cause pulmonary diseases with infrared light: an in vitro study

    NASA Astrophysics Data System (ADS)

    Leite, Ilaiáli S.; Geralde, Mariana C.; Salina, Ana C.; Medeiros, Alexandra I.; Kurachi, Cristina; Bagnato, Vanderlei S.; Inada, Natalia M.

    2014-03-01

    Lower respiratory infections are among the leading causes of death worldwide. In this study, it was evaluated the interaction of indocyanine green, a photosensitizer activated by infrared light, with alveolar macrophages and the effectiveness of the photodynamic therapy using this compound against Streptococcus pneumoniae . Initial experiments analyzed indocyanine green toxicity to alveolar macrophages in the dark with different drug concentrations and incubation times, and macrophage viability was obtained with the MTT method. The average of the results showed viability values below 90% for the two highest concentrations. Experiments with Streptococcus pneumoniae showed photodynamic inactivation with 10 μM indocyanine green solution. Further experiments with the bacteria in co-culture with AM will be conducted verifying the photodynamic inactivation effectiveness of the tested drug concentrations and incubation periods using infrared light.

  3. Plasmonic Nanoparticle-based Hybrid Photosensitizers with Broadened Excitation Profile for Photodynamic Therapy of Cancer Cells

    PubMed Central

    Wang, Peng; Tang, Hong; Zhang, Peng

    2016-01-01

    Photodynamic therapy combining nanotechnology has shown great potential with improved therapeutic efficacy and fewer side effects. Ideal photosensitizers for cancer treatment should both have good singlet oxygen production capability and be excitable by light illuminations with deep tissue penetration. Here we report a type of hybrid photosensitizers consisting of plasmonic silver nanoparticles and photosensitizing molecules, where strong resonance coupling between the two leads to a broadened excitation profile and exceptionally high singlet oxygen production under both visible light and infrared light excitations. Our results indicate that the hybrid photosensitizers display low cytotoxicity without light illumination yet highly enhanced photodynamic inhibition efficacy against Hela cells under a broad spectrum of light illuminations including the near-infrared light, which has great implication in photodynamic therapy of deep-tissue cancers. PMID:27725746

  4. Investigation of myocardial photodynamic revascularization method on ischemic rat myocardium model

    NASA Astrophysics Data System (ADS)

    Vasilchenko, S. Yu.; Stratonnikov, A. A.; Volkova, A. I.; Loschenov, V. B.; Sheptak, E. A.; Kharnas, S. S.

    2006-08-01

    Ischemic heart disease is one of the leading reasons of invalidisation and death rate of able-bodied citizens in the world. There are many various surgical and medicamentous methods of its treatment for today, however all these methods have restrictions in application. Our work was directed at initiation possibility clarification of ischemic myocardium revascularization by means of making necrosis with photodynamic therapy. The investigation was carried out in rats with the ischemia artificial made by means of left coronary artery ligation. Level of Photosense photosensitizer accumulation in ischemic and normal rat myocardium zones was defined. Myocardial photodynamic revascularization procedure of ischemic rat myocardium was carried out. Morphological analysis of the myocardium preparations showed the presence of active revascularization of ischemic myocardium after photodynamic therapy. The method of ischemia level estimation based on spectral optical definition of blood oxygen saturation was developed.

  5. Plasmonic copper sulfide nanocrystals exhibiting near-infrared photothermal and photodynamic therapeutic effects.

    PubMed

    Wang, Shunhao; Riedinger, Andreas; Li, Hongbo; Fu, Changhui; Liu, Huiyu; Li, Linlin; Liu, Tianlong; Tan, Longfei; Barthel, Markus J; Pugliese, Giammarino; De Donato, Francesco; Scotto D'Abbusco, Marco; Meng, Xianwei; Manna, Liberato; Meng, Huan; Pellegrino, Teresa

    2015-02-24

    Recently, plasmonic copper sulfide (Cu2-xS) nanocrystals (NCs) have attracted much attention as materials for photothermal therapy (PTT). Previous reports have correlated photoinduced cell death to the photothermal heat mechanism of these NCs, and no evidence of their photodynamic properties has been reported yet. Herein we have prepared physiologically stable near-infrared (NIR) plasmonic copper sulfide NCs and analyzed their photothermal and photodynamic properties, including therapeutic potential in cultured melanoma cells and a murine melanoma model. Interestingly, we observe that, besides a high PTT efficacy, these copper sulfide NCs additionally possess intrinsic NIR induced photodynamic activity, whereupon they generate high levels of reactive oxygen species. Furthermore, in vitro and in vivo acute toxic responses of copper sulfide NCs were also elicited. This study highlights a mechanism of NIR light induced cancer therapy, which could pave the way toward more effective nanotherapeutics.

  6. Photodynamic antimicrobial effects of bis-indole alkaloid indigo from Indigofera truxillensis Kunth (Leguminosae).

    PubMed

    Andreazza, Nathalia Luiza; de Lourenço, Caroline C; Stefanello, Maria Élida Alves; Atvars, Teresa Dib Zambon; Salvador, Marcos José

    2015-05-01

    Multidrug-resistant microbial infections represent an exponentially growing problem affecting communities worldwide. Photodynamic therapy is a promising treatment based on the combination of light, oxygen, and a photosensitizer that leads to reactive oxygen species production, such as superoxide (type I mechanism) and singlet oxygen (type II mechanism) that cause massive oxidative damage and consequently the host cell death. Indigofera genus has gained considerable interest due its mutagenic, cytotoxic, and genotoxic activity. Therefore, this study was undertaken to investigate the effect of crude extracts, alkaloidal fraction, and isolated substance derived from Indigofera truxillensis in photodynamic antimicrobial chemotherapy on the viability of bacteria and yeast and evaluation of mechanisms involved. Our results showed that all samples resulted in microbial photoactivation in subinhibitory concentration, with indigo alkaloid presenting a predominant photodynamic action through type I mechanism. The use of CaCl2 and MgCl2 as cell permeabilizing additives also increased gram-negative bacteria susceptibility to indigo.

  7. Plasmonic Nanoparticle-based Hybrid Photosensitizers with Broadened Excitation Profile for Photodynamic Therapy of Cancer Cells

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Tang, Hong; Zhang, Peng

    2016-10-01

    Photodynamic therapy combining nanotechnology has shown great potential with improved therapeutic efficacy and fewer side effects. Ideal photosensitizers for cancer treatment should both have good singlet oxygen production capability and be excitable by light illuminations with deep tissue penetration. Here we report a type of hybrid photosensitizers consisting of plasmonic silver nanoparticles and photosensitizing molecules, where strong resonance coupling between the two leads to a broadened excitation profile and exceptionally high singlet oxygen production under both visible light and infrared light excitations. Our results indicate that the hybrid photosensitizers display low cytotoxicity without light illumination yet highly enhanced photodynamic inhibition efficacy against Hela cells under a broad spectrum of light illuminations including the near-infrared light, which has great implication in photodynamic therapy of deep-tissue cancers.

  8. Analysis of superficial fluorescence patterns in nonmelanoma skin cancer during photodynamic therapy by a dosimetric model

    NASA Astrophysics Data System (ADS)

    Salas-García, I.; Fanjul-Vélez, F.; Arce-Diego, J. L.

    2016-03-01

    In this work the superficial fluorescence patterns in different nonmelanoma skin cancers and their photodynamic treatment response are analysed by a fluorescence based dosimetric model. Results show differences of even more than 50% in the fluorescence patterns as photodynamic therapy progresses depending on the malignant tissue type. They demonstrate the great relevance of the biological media as an additional dosimetric factor and contribute to the development of a future customized therapy with the assistance of dosimetric tools to interpret the fluorescence images obtained during the treatment monitoring and the differential photodiagnosis.

  9. Photodynamic therapy for diffuse choroidal hemangioma in a child with Sturge-Weber syndrome.

    PubMed

    Nugent, Ryan; Lee, Lawrence; Kwan, Anthony

    2015-04-01

    Sturge-Weber syndrome is a rare neurocutaneous disorder involving the leptomeninges, skin of the face, and, in 40% of cases, diffuse choroidal hemangioma. We report the case of a 6-year-old girl with Sturge-Weber syndrome and a large diffuse choroidal hemangioma with retinal detachment involving the majority of the retina. The patient underwent photodynamic therapy. The retinal detachment resolved completely within 3 months of treatment. This case represents the youngest patient in the literature to undergo successful treatment with photodynamic therapy for Sturge-Weber syndrome-associated diffuse choroidal hemangioma. PMID:25828818

  10. Photosensitizer anchored gold nanorods for targeted combinational photothermal and photodynamic therapy.

    PubMed

    Tham, Huijun Phoebe; Chen, Hongzhong; Tan, Yu Hui; Qu, Qiuyu; Sreejith, Sivaramapanicker; Zhao, Lingzhi; Venkatraman, Subbu S; Zhao, Yanli

    2016-07-01

    Silylated zinc phthalocyanine (ZnPc) was anchored onto silica-coated gold nanorods (AuNR) with retained local surface plasmon resonance (LSPR). Independent LSPR and singlet oxygen production of anchored ZnPc enhance the photothermal and photodynamic efficacy of the obtained AuNR-Si-ZnPc under NIR light excitation. AuNR-Si-ZnPc was further grafted with hyaluronic acid (HA). Since HA has selective targeting capability to CD44 antigens, the final hybrid could target cancer cells directly for synergistic photothermal and photodynamic therapy. PMID:27346609

  11. Treatment parameters affecting the response of normal brain to photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Chen, Qun; Chopp, Michael; Dereski, Mary O.; Wilson, Brian C.; Patterson, Michael S.; Kessel, David; Heads, Larry; Hetzel, Fred W.

    1993-06-01

    Different aspects of photodynamic therapy in normal rat brain tissue have been studied, in an effort to understand and improve the dosimetry of this new modality in treatment of brain tumors. dosimetry parameters, including light energy dose, fluence rate and beam size, and drug dosage were studied. PDT induced lesion depth in brain was measured as a biological endpoint. Effective attenuation depth and absolute light fluence rate distribution under superficial irradiation were measured using invasive optical probes. Photosensitizer uptake was quantified using HPLC analysis. The results indicate that normal brain have a high intrinsic sensitivity to PDT treatment, based on the estimated photodynamic threshold.

  12. Therapeutic and Aesthetic Uses of Photodynamic Therapy Part One of a Five-Part Series

    PubMed Central

    2008-01-01

    The utilization of aminolevulinic acid–photodynamic therapy in dermatology has steadily been on the rise since its introduction into our therapeutic armamentarium almost 10 years ago. Clinicians are realizing the continued benefits of this therapy from a therapeutic and cosmetic/aesthetic outcome. This was first seen in the treatment of nonhyperkeratotic actinic keratoses of the face and scalp where resolution of the actinic keratoses was achieved and a cosmetic improvement noted from the therapies. Clinicians are embracing photorejuvenation utilizing aminolevulinic acid–photodynamic therapy, which is reviewed in this article. PMID:21103321

  13. Contrast enhanced-magnetic resonance imaging as a surrogate to map verteporfin delivery in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Samkoe, Kimberley S.; Bryant, Amber; Gunn, Jason R.; Pereira, Stephen P.; Hasan, Tayyaba; Pogue, Brian W.

    2013-12-01

    The use of in vivo contrast-enhanced magnetic resonance (MR) imaging as a surrogate for photosensitizer (verteporfin) dosimetry in photodynamic therapy of pancreas cancer is demonstrated by correlating MR contrast uptake to ex vivo fluorescence images on excised tissue. An orthotopic pancreatic xenograft mouse model was used for the study. A strong correlation (r=0.57) was found for bulk intensity measurements of T1-weighted gadolinium enhancement and verteporfin fluorescence in the tumor region of interest. The use of contrast-enhanced MR imaging shows promise as a method for treatment planning and photosensitizer dosimetry in human photodynamic therapy (PDT) of pancreas cancer.

  14. Combined photothermal and photodynamic therapy delivered by PEGylated MoS2 nanosheets

    NASA Astrophysics Data System (ADS)

    Liu, Teng; Wang, Chao; Cui, Wei; Gong, Hua; Liang, Chao; Shi, Xiaoze; Li, Zhiwei; Sun, Baoquan; Liu, Zhuang

    2014-09-01

    Single- or few-layered transitional metal dichalcogenides, as a new genus of two-dimensional nanomaterials, have attracted tremendous attention in recent years, owing to their various intriguing properties. In this study, chemically exfoliated MoS2 nanosheets are modified with lipoic acid-terminated polyethylene glycol (LA-PEG), obtaining PEGylated MoS2 (MoS2-PEG) with high stability in physiological solutions and no obvious toxicity. Taking advantage of its ultra-high surface area, the obtained MoS2-PEG is able to load a photodynamic agent, chlorin e6 (Ce6), by physical adsorption. In vitro experiments reveal that Ce6 after being loaded on MoS2-PEG shows remarkably increased cellular uptake and thus significantly enhanced photodynamic therapeutic efficiency. Utilizing the strong, near-infrared (NIR) absorbance of the MoS2 nanosheets, we further demonstrate photothermally enhanced photodynamic therapy using Ce6-loaded MoS2-PEG for synergistic cancer killing, in both in vitro cellular and in vivo animal experiments. Our study presents a new type of multifunctional nanocarrier for the delivery of photodynamic therapy, which, if combined with photothermal therapy, appears to be an effective therapeutic approach for cancer treatment.Single- or few-layered transitional metal dichalcogenides, as a new genus of two-dimensional nanomaterials, have attracted tremendous attention in recent years, owing to their various intriguing properties. In this study, chemically exfoliated MoS2 nanosheets are modified with lipoic acid-terminated polyethylene glycol (LA-PEG), obtaining PEGylated MoS2 (MoS2-PEG) with high stability in physiological solutions and no obvious toxicity. Taking advantage of its ultra-high surface area, the obtained MoS2-PEG is able to load a photodynamic agent, chlorin e6 (Ce6), by physical adsorption. In vitro experiments reveal that Ce6 after being loaded on MoS2-PEG shows remarkably increased cellular uptake and thus significantly enhanced photodynamic

  15. Development of Photodynamic Antimicrobial Chemotherapy (PACT) for Clostridium difficile

    PubMed Central

    Pye, Hayley; Kohoutova, Darina; Mosse, Charles A.; Yahioglu, Gokhan; Stamati, Ioanna; Deonarain, Mahendra; Battah, Sinan; Ready, Derren; Allan, Elaine; Mullany, Peter; Lovat, Laurence B.

    2015-01-01

    Background Clostridium difficile is the leading cause of antibiotic-associated diarrhoea and pseudo membranous colitis in the developed world. The aim of this study was to explore whether Photodynamic Antimicrobial Chemotherapy (PACT) could be used as a novel approach to treating C. difficile infections. Methods PACT utilises the ability of light-activated photosensitisers (PS) to produce reactive oxygen species (ROS) such as free radical species and singlet oxygen, which are lethal to cells. We screened thirteen PS against C. difficile planktonic cells, biofilm and germinating spores in vitro, and cytotoxicity of effective compounds was tested on the colorectal adenocarcinoma cell-line HT-29. Results Three PS were able to kill 99.9% of bacteria in both aerobic and anaerobic conditions, both in the planktonic state and in a biofilm, after exposure to red laser light (0.2 J/cm2) without harming model colon cells. The applicability of PACT to eradicate C. difficile germinative spores indirectly was also shown, by first inducing germination with the bile salt taurocholate, followed by PACT. Conclusion This innovative and simple approach offers the prospect of a new antimicrobial therapy using light to treat C. difficile infection of the colon. PMID:26313448

  16. Fluorescence guided evaluation of photodynamic therapy as acne treatment

    NASA Astrophysics Data System (ADS)

    Ericson, Marica B.; Horfelt, Camilla; Cheng, Elaine; Larsson, Frida; Larko, Olle; Wennberg, Ann-Marie

    2005-08-01

    Photodynamic therapy (PDT) is an attractive alternative treatment for patients with acne because of its efficiency and few side effects. Propionibacterium acnes (P.acnes) are bacteria present in the skin, which produce endogenous porphyrins that act as photosensitisers. In addition, application of aminolaevulinic acid or its methyl ester (mALA) results in increased accumulation of porphyrins in the pilosebaceous units. This makes it possible to treat acne with PDT. This initial study investigates the possibility of fluorescence imaging as assessment tool in adjunct to PDT of patients with acne. Twenty-four patients with acne on the cheeks have been treated with PDT with and without mALA. Fluorescence images have been obtained before and after treatment. The clinical acne score was assessed as base line before PDT, and at every follow up visit. Additionally the amount of P.acnes was determined. The clinical evaluation showed a general improvement of acne, even though no difference between treatment with and without mALA was observed. By performing texture analysis and multivariate data analsysis on the fluorescence images, the extracted texture features were found to correlate with the corresponding clinical assessment (67%) and amount of P.acnes (72%). The analysis showed that features describing the highly fluorescent pores could be related to the clinical assessment. This result suggests that fluorescence imaging can be used as an objective assessment of acne, but further improvement of the technique is possible, for example by including colour images.

  17. An update on photodynamic therapies in the treatment of onychomycosis.

    PubMed

    Simmons, B J; Griffith, R D; Falto-Aizpurua, L A; Nouri, K

    2015-07-01

    Onychomycosis is a common fungal infection of the nails that is increasing in prevalence in the old, diabetics and immunocompromised. Onychomycosis presents a therapeutic challenge that can lead to significant reductions in quality of life leading to both physical and psychological consequences. Current treatment modalities are difficult to implement due to the poor penetration of topical treatments to the nail bed, the slow growing nature of nails and the need for prolonged use of topical and/or oral medications. Standard of care medications have cure rates of 63-76% that leads to a high propensity of treatment failures and recurrences. Photodynamic therapy (PDT) offers an alternative treatment for onychomycosis. Methylene blue dye, methyl-aminolevulinate (MAL) and aminolevulinic acid (ALA) have been used as photosensitizers with approximately 630 nm light. These modalities are combined with pre-treatment of urea and/or microabrasion for better penetration. PDT treatments are well tolerated with only mild transient pain, burning and erythema. In addition, significant cure rates for patients who have contraindications to oral medications or failed standard medications can be obtained. With further enhancements in photosensitizer permeability, decreased pre-treatment and photosensitizer incubation times, PDT can be a more efficient and cost-effective in office based treatment for onychomycosis. However, more large-scale randomized control clinical trials are needed to access the efficacy of PDT treatments. PMID:25589056

  18. Measurement of photodynamic therapy drug concentrations in a tissue

    SciTech Connect

    Mourant, J.; Biglo, I.; Johnson, T.

    1996-09-01

    This is the final report of a one-year laboratory-directed research and development project at the Los Alamos National Laboratory (LANL). Photodynamic therapy (PDT) is an experimental treatment modality for cancer in which a photoactive molecule with an affinity for tumors in administered to the patient, then excited by light. Photoactivation creates singlet oxygen consequently killing the tissue. Knowledge of the concentration of the photoactive compound in the tissue is necessary for proper light dosimetry during PDT. Presently, the control of light application is problematic. If too much light is applied, damage to the surrounding tissue will occur. If insufficient light is applied, the targeted tissue volume will remain viable. The ideal implementation of PDT would use a feedback system for light delivery that incorporates the optical properties of the tissue and knowledge of the concentration of the photoactive compound. This project sought to develop a method for measuring photosensitizer concentrations in tissue phantoms that will lead to a noninvasive, endoscopically compatible, in vivo method of measuring PST drug concentrations.

  19. Layered bismuth oxyhalide nanomaterials for highly efficient tumor photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Xu, Yu; Shi, Zhenzhi; Zhang, Ling'e.; Brown, Eric Michael Bratsolias; Wu, Aiguo

    2016-06-01

    Layered bismuth oxyhalide nanomaterials have received much more interest as promising photocatalysts because of their unique layered structures and high photocatalytic performance, which can be used as potential inorganic photosensitizers in tumor photodynamic therapy (PDT). In recent years, photocatalytic materials have been widely used in PDT and photothermal therapy (PTT) as inorganic photosensitizers. This investigation focuses on applying layered bismuth oxyhalide nanomaterials toward cancer PDT, an application that has never been reported so far. The results of our study indicate that the efficiency of UV-triggered PDT was highest when using BiOCl nanoplates followed by BiOCl nanosheets, and then TiO2. Of particular interest is the fact that layered BiOCl nanomaterials showed excellent PDT effects under low nanomaterial dose (20 μg mL-1) and low UV dose (2.2 mW cm-2 for 10 min) conditions, while TiO2 showed almost no therapeutic effect under the same parameters. BiOCl nanoplates and nanosheets have shown excellent performance and an extensive range of applications in PDT.

  20. Photodynamic therapy for experimental intraocular melanoma using chloroaluminum sulfonated phthalocyanine

    SciTech Connect

    Panagopoulos, J.A.; Svitra, P.P.; Puliafito, C.A.; Gragoudas, E.S.

    1989-06-01

    Chloroaluminum sulfonated phthalocyanine (CASPc), a novel photosensitizing dye, was evaluated for treatment of experimental intraocular melanoma in 33 rabbit eyes. An argon ion pumped dye laser, operating at an emission of 675 nm, was used in a nonthermal mode to irradiate iris tumors in rabbits 24 hours after they received in intravenous dye injection (23 eyes). The effects of laser irradiation alone and dye alone were examined in ten control eyes. A threshold tumoricidal dose was established for photodynamic therapy with CASPc and laser irradiation. Vascular occlusion was produced in a well-circumscribed area corresponding to the boundaries of laser irradiation after CASPc injection. Tumors successfully treated with CASPc and laser irradiation were arrested in growth and exhibited no viable tumor cells on histologic examination. Control tumors continued rapid growth, unaffected by dye or laser. Our data indicate that CASPc demonstrates a strong photosensitizing effect on both tumor and normal tissue. These results suggest that CASPc is a potential photosensitizing compound that may be useful in the treatment of choroidal melanoma.