Engineering Remotely Triggered Liposomes to Target Triple Negative Breast Cancer

PubMed Central

Sneider, Alexandra; Jadia, Rahul; Piel, Brandon; VanDyke, Derek; Tsiros, Christopher; Rai, Prakash

2017-01-01

Triple Negative Breast Cancer (TNBC) continues to present a challenge in the clinic, as there is still no approved targeted therapy. TNBC is the worst sub-type of breast cancer in terms of prognosis and exhibits a deficiency in estrogen, progesterone, and human epidermal growth factor 2 (HER2) receptors. One possible option for the treatment of TNBC is chemotherapy. The issue with many chemotherapy drugs is that their effectiveness is diminished due to poor water solubility, and the method of administration directly or with a co-solvent intravenously can lead to an increase in toxicity. The issues of drug solubility can be avoided by using liposomes as a drug delivery carrier. Liposomes are engineered, biological nanoconstructs that possess the ability to encapsulate both hydrophobic and hydrophilic drugs and have been clinically approved to treat cancer. Specific targeting of cancer cell receptors through the use of ligands conjugated to the surface of drug-loaded liposomes could lessen damage to normal, healthy tissue. This study focuses on polyethylene glycol (PEG)-coated, folate conjugated, benzoporphyrin derivative (BPD)-loaded liposomes for treatment via photodynamic therapy (PDT). The folate receptor is over expressed on TNBC cells so these liposomes are targeted for greater uptake into cancer cells. PDT involves remotely irradiating light at 690 nm to trigger BPD, a hydrophobic photosensitive drug, to form reactive oxygen species that cause tumor cell death. BPD also displays a fluorescence signal when excited by light making it possible to image the fluorescence prior to PDT and for theranostics. In this study, free BPD, non-targeted and folate-targeted PEGylated BPD-loaded liposomes were introduced to a metastatic breast cancer cell line (MDA-MB-231) in vitro. The liposomes were reproducibly synthesized and characterized for size, polydispersity index (PDI), zeta potential, stability, and BPD release kinetics. Folate competition tests, fluorescence

Effects of surface displayed targeting ligand GE11 on liposome distribution and extravasation in tumor.

PubMed

Tang, Hailing; Chen, Xiaojing; Rui, Mengjie; Sun, Wenqiang; Chen, Jian; Peng, Jinliang; Xu, Yuhong

2014-10-06

Targeting ligands displayed on liposome surface had been used to mediate specific interactions and drug delivery to target cells. However, they also affect liposome distribution in vivo, as well as the tissue extravasation processes after IV injection. In this study, we incorporated an EGFR targeting peptide GE11 on liposome surfaces in addition to PEG at different densities and evaluated their targeting properties and antitumor effects. We found that the densities of surface ligand and PEG were critical to target cell binding in vitro as well as pharmacokinetic profiles in vivo. The inclusion of GE11-PEG-DSPE and PEG-DSPE at 2% and 4% mol ratios in the liposome formulation mediated a rapid accumulation of liposomes within 1 h after IV injection in the tumor tissues surrounding neovascular structures. This is in addition to the EPR effect that was most prominently described for surface PEG modified liposomes. Therefore, despite the fact that the distribution of liposomes into interior tumor tissues was still limited by diffusion, GE11 targeted doxorubicin loaded liposomes showed significantly better antitumor activity in tumor bearing mice as a result of the fast active-targeting efficiency. We anticipate these understandings can benefit further optimization of targeted drug delivery systems for improving efficacy in vivo.

A new liposome-based gene delivery system targeting lung epithelial cells using endothelin antagonist.

PubMed

Allon, Nahum; Saxena, Ashima; Chambers, Carolyn; Doctor, Bhupendra P

2012-06-10

We formulated a new gene delivery system based on targeted liposomes. The efficacy of the delivery system was demonstrated in in vitro and in vivo models. The targeting moiety consists of a high-affinity 7-amino-acid peptide, covalently and evenly conjugated to the liposome surface. The targeting peptide acts as an endothelin antagonist, and accelerates liposome binding and internalization. It is devoid of other biological activity. Liposomes with high phosphatidyl serine (PS) were specially formulated to help their fusion with the endosomal membrane at low pH and enable release of the liposome payload into the cytoplasm. A DNA payload, pre-compressed by protamine, was encapsulated into the liposomes, which directed the plasmid into the cell's nucleus. Upon exposure to epithelial cells, binding of the liposomes occurred within 5-10 min, followed by facilitated internalization of the complex. Endosomal escape was complete within 30 min, followed by DNA accumulation in the nucleus 2h post-transfection. A549 lung epithelial cells transfected with plasmid encoding for GFP encapsulated in targeted liposomes expressed significantly more protein than those transfected with plasmid complexed with Lipofectamine. The intra-tracheal instillation of plasmid encoding for GFP encapsulated in targeted liposomes into rat lungs resulted in the expression of GFP in bronchioles and alveoli within 5 days. These results suggest that this delivery system has great potential in targeting genes to lungs. Copyright © 2011 Elsevier B.V. All rights reserved.

Laser-induced disruption of systemically administered liposomes for targeted drug delivery

NASA Astrophysics Data System (ADS)

Mackanos, Mark A.; Larabi, Malika; Shinde, Rajesh; Simanovskii, Dmitrii M.; Guccione, Samira; Contag, Christopher H.

2009-07-01

Liposomal formulations of drugs have been shown to enhance drug efficacy by prolonging circulation time, increasing local concentration and reducing off-target effects. Controlled release from these formulations would increase their utility, and hyperthermia has been explored as a stimulus for targeted delivery of encapsulated drugs. Use of lasers as a thermal source could provide improved control over the release of the drug from the liposomes with minimal collateral tissue damage. Appropriate methods for assessing local release after systemic delivery would aid in testing and development of better formulations. We use in vivo bioluminescence imaging to investigate the spatiotemporal distribution of luciferin, used as a model small molecule, and demonstrate laser-induced release from liposomes in animal models after systemic delivery. These liposomes were tested for luciferin release between 37 and 45 °C in PBS and serum using bioluminescence measurements. In vivo studies were performed on transgenic reporter mice that express luciferase constitutively throughout the body, thus providing a noninvasive readout for controlled release following systemic delivery. An Nd:YLF laser was used (527 nm) to heat tissues and induce rupture of the intravenously delivered liposomes in target tissues. These data demonstrate laser-mediated control of small molecule delivery using thermally sensitive liposomal formulations.

Hyaluronic acid modified pH-sensitive liposomes for targeted intracellular delivery of doxorubicin.

PubMed

Paliwal, Shivani Rai; Paliwal, Rishi; Agrawal, Govind Prasad; Vyas, Suresh Prasad

2016-12-01

Surface-modified pH-sensitive liposomal system may be useful for intracellular delivery of chemotherapeutics. Achieving site-specific targeting with over-expressed hyaluronic acid (HA) receptors along with using pH sensitive liposome carrier for intracellular drug delivery was the aim of this study. Stealth HA-targeted pH-sensitive liposomes (SL-pH-HA) were developed and evaluated to achieve effective intracellular delivery of doxorubicin (DOX) vis-a-vis enhanced antitumor activity. The in vitro release studies demonstrated that the release of DOX from SL-pH-HA was pH-dependent, i.e. faster at mildly acidic pH ∼5, compared to physiological pH ∼7.4. SLpH-HA was evaluated for their cytotoxicity potential on CD44 receptor expressing MCF-7 cells. The half maximal inhibitory concentration (IC50) of SL-pH-HA and SL-HA were about 1.9 and 2.5 μM, respectively, after 48 h of incubation. The quantitative uptake study revealed higher localization of targeted liposomes in the receptor positive cells, which was further confirmed by fluorescent microscopy. The antitumor efficacy of the DOX-loaded HA-targeted pH-sensitive liposomes was also verified in a tumor xenograft mouse model. DOX was efficiently delivered to the tumor site by active targeting via HA and CD44 receptor interaction. The major side-effect of conventional DOX formulation, i.e. cardiotoxicity was also estimated by measuring serum enzyme levels of LDH and CPK and found to be minimized with developed formulation. Overall, HA targeted pH-sensitive liposomes were significantly more potent than the non-targeted liposomes in cells expressing high levels of CD44. Results strongly implies the promise of such liposomal system as an intracellular drug delivery carrier developed for potential anticancer treatment.

Application of liposomes in drug development — focus on gastroenterological targets

PubMed Central

Zhang, Jian-Xin; Wang, Kun; Mao, Zheng-Fa; Fan, Xin; Jiang, De-Li; Chen, Min; Cui, Lei; Sun, Kang; Dang, Sheng-Chun

2013-01-01

Over the past decade, liposomes became a focal point in developing drug delivery systems. New liposomes, with novel lipid molecules or conjugates, and new formulations opened possibilities for safely and efficiently treating many diseases including cancers. New types of liposomes can prolong circulation time or specifically deliver drugs to therapeutic targets. This article concentrates on current developments in liposome based drug delivery systems for treating diseases of the gastrointestinal tract. We will review different types and uses of liposomes in the development of therapeutics for gastrointestinal diseases including inflammatory bowel diseases and colorectal cancer. PMID:23630417

Application of multifunctional targeting epirubicin liposomes in the treatment of non-small-cell lung cancer

PubMed Central

Song, Xiao-li; Ju, Rui-jun; Xiao, Yao; Wang, Xin; Liu, Shuang; Fu, Min; Liu, Jing-jing; Gu, Li-yan; Li, Xue-tao; Cheng, Lan

2017-01-01

Chemotherapy for aggressive non-small-cell lung cancer (NSCLC) usually results in a poor prognosis due to tumor metastasis, vasculogenic mimicry (VM) channels, limited killing of tumor cells, and severe systemic toxicity. Herein, we developed a kind of multifunctional targeting epirubicin liposomes to enhance antitumor efficacy for NSCLC. In the liposomes, octreotide was modified on liposomal surface for obtaining a receptor-mediated targeting effect, and honokiol was incorporated into the lipid bilayer for inhibiting tumor metastasis and eliminating VM channels. In vitro cellular assays showed that multifunctional targeting epirubicin liposomes not only exhibited the strongest cytotoxic effect on Lewis lung tumor cells but also showed the most efficient inhibition on VM channels. Action mechanism studies showed that multifunctional targeting epirubicin liposomes could downregulate PI3K, MMP-2, MMP-9, VE-Cadherin, and FAK and activate apoptotic enzyme caspase 3. In vivo results exhibited that multifunctional targeting epirubicin liposomes could accumulate selectively in tumor site and display an obvious antitumor efficacy. In addition, no significant toxicity of blood system and major organs was observed at a test dose. Therefore, multifunctional targeting epirubicin liposomes may provide a safe and efficient therapy strategy for NSCLC. PMID:29066893

Dosimetric model for intraperitoneal targeted liposomal radioimmunotherapy of ovarian cancer micrometastases

NASA Astrophysics Data System (ADS)

Syme, A. M.; McQuarrie, S. A.; Middleton, J. W.; Fallone, B. G.

2003-05-01

A simple model has been developed to investigate the dosimetry of micrometastases in the peritoneal cavity during intraperitoneal targeted liposomal radioimmunotherapy. The model is applied to free-floating tumours with radii between 0.005 cm and 0.1 cm. Tumour dose is assumed to come from two sources: free liposomes in solution in the peritoneal cavity and liposomes bound to the surface of the micrometastases. It is assumed that liposomes do not penetrate beyond the surface of the tumours and that the total amount of surface antigen does not change over the course of treatment. Integrated tumour doses are expressed as a function of biological parameters that describe the rates at which liposomes bind to and unbind from the tumour surface, the rate at which liposomes escape from the peritoneal cavity and the tumour surface antigen density. Integrated doses are translated into time-dependent tumour control probabilities (TCPs). The results of the work are illustrated in the context of a therapy in which liposomes labelled with Re-188 are targeted at ovarian cancer cells that express the surface antigen CA-125. The time required to produce a TCP of 95% is used to investigate the importance of the various parameters. The relative contributions of surface-bound radioactivity and unbound radioactivity are used to assess the conditions required for a targeted approach to provide an improvement over a non-targeted approach during intraperitoneal radiation therapy. Using Re-188 as the radionuclide, the model suggests that, for microscopic tumours, the relative importance of the surface-bound radioactivity increases with tumour size. This is evidenced by the requirement for larger antigen densities on smaller tumours to affect an improvement in the time required to produce a TCP of 95%. This is because for the smallest tumours considered, the unbound radioactivity is often capable of exerting a tumouricidal effect before the targeting agent has time to accumulate

Pirfenidone-loaded liposomes for lung targeting: preparation and in vitro/in vivo evaluation

PubMed Central

Meng, Hui; Xu, Yong

2015-01-01

Background The purpose of this study was to develop novel pirfenidone (PFD)-loaded liposomes for targeting to the lung. Methods The liposomes were prepared by the film hydration method, and their in vitro/vivo characteristics were evaluated. Results The PFD liposomes appeared visually as green to yellowish suspensions and were spherical in shape. The particle size was 582.3±21.6 nm and the entrapment efficiency was relatively high (87.2%±5.7%). The liposomes showed typical sustained and prolonged drug-release behavior in vitro and fitted well with the Weibull distribution equation. The relatively slower time taken to reach a minimal plasma PFD concentration in vivo suggests that PFD liposomes have a sustained-release profile, which is consistent with the results of the in vitro release study. The PFD liposomes showed the largest area under the curve for the lung. The high distribution of PFD achieved in the lungs using this liposomal formulation may be explained by physical entrapment of the liposomes in the vascular network of the lung. Histopathological results indicated that liposomal PFD could alleviate pathological injury in lung tissue. Conclusion This liposomal formulation can enable sustained release of PFD and increase targeting to the lung. PMID:26185416

MRI-visible liposome nanovehicles for potential tumor-targeted delivery of multimodal therapies

NASA Astrophysics Data System (ADS)

Ren, Lili; Chen, Shizhen; Li, Haidong; Zhang, Zhiying; Ye, Chaohui; Liu, Maili; Zhou, Xin

2015-07-01

Real-time diagnosis and monitoring of disease development, and therapeutic responses to treatment, are possible by theranostic magnetic resonance imaging (MRI). Here we report the synthesis of a multifunctional liposome, which contains Gd-DOTA (an MRI probe), paclitaxel and c(RGDyk) (a targeted peptide). This nanoparticle overcame the insolubility of paclitaxel, reduced the side effects of FDA-approved formulation of PTX-Cre (Taxol®) and improved drug delivery efficiency to the tumor. c(RGDyk) modification greatly enhanced the cytotoxicity of the drug in tumor cells A549. The T1 relaxivity in tumor cells treated with the targeted liposome formulation was increased 16-fold when compared with the non-targeted group. In vivo, the tumors in mice were visualized using T1-weighted imaging after administration of the liposome. Also the tumor growth could be inhibited well after the treatment. Fluorescence images in vitro and ex vivo also showed the targeting effect of this liposome in tumor cells, indicating that this nanovehicle could limit the off-target side effects of anticancer drugs and contrast agents. These findings lay the foundation for further tumor inhibition study and application of this delivery vehicle in cancer therapy settings.

Targeting doxorubicin encapsulated in stealth liposomes to solid tumors by non thermal diode laser.

PubMed

Ghannam, Magdy M; El Gebaly, Reem; Fadel, Maha

2016-04-05

The use of liposomes as drug delivery systems is the most promising technique for targeting drug especially for anticancer therapy. In this study sterically stabilized liposomes was prepared from DPPC/Cholesterol/PEG-PE encapsulated doxorubicin. The effect of lyophilization on liposomal stability and hence expiration date were studied. Moreover, the effect of diode laser on the drug released from liposomesin vitro and in vivo in mice carrying implanted solid tumor were also studied. The results indicated that lyophilization of the prepared liposomes encapsulating doxorubicin led to marked stability when stored at 5 °C and it is possible to use the re-hydrated lyophilized liposomes within 12 days post reconstitution. Moreover, the use of low energy diode laser for targeting anticancer drug to the tumor cells is a promising method in cancer therapy. We can conclude that lyophilization of the liposomes encapsulating doxorubicin lead to marked stability for the liposomes when stored at 5 °C. Moreover, the use of low energy diode laser for targeting anticancer drug to the tumor cells through the use of photosensitive sterically stabilized liposomes loaded with doxorubicin is a promising method. It proved to be applicable and successful for treatment of Ehrlich solid tumors implanted in mice and eliminated toxic side effects of doxorubicin.

Hyaluronic acid-coated liposomes for targeted delivery of paclitaxel, in-vitro characterization and in-vivo evaluation.

PubMed

Ravar, Fatemeh; Saadat, Ebrahim; Gholami, Mehdi; Dehghankelishadi, Pouya; Mahdavi, Mehdi; Azami, Samira; Dorkoosh, Farid A

2016-05-10

Breast cancer is the leading cause of cancer death in women. Chemotherapy is regarded as the most essential strategy in inhibiting the proliferation of tumor cells. Paclitaxel is a widely used taxane; however, the side effects of available Cremophor-based formulations and also the limitations of passive targeting uncovered an essential need to develop tumor-specific targeted nanocarriers. A hyaluronic acid targeted liposomal formulation of paclitaxel was prepared in which, hyaluronic acid was electrostatistically attracted to the surface of liposomes. Liposomes, had a particle size of 106.4±3.2nm, a weakly negative zeta potential of -9.7±0.8mV and an acceptable encapsulation efficiency of 92.1±1.7%. The release profile of liposomes in buffer showed that 95% of PTX was released during 40h. Confocal laser scanning microscopy and flow cytometry analysis showed the greater cellular internalization of coumarin-loaded liposomes compared to free coumarin. MTT assay on 4T1 and T47D cells demonstrated the stronger cytotoxic activity of liposomes in comparison to free paclitaxel. Cell cycle analysis showed that cells were mainly blocked at G2/M phases after 48h treatment with liposomes. In vivo real time imaging on 4T1 tumor-bearing mice revealed that the liposomal formulation mainly accumulated in the tumor area. Liposomes also had better antitumor efficacy against Cremophor-based formulation. In conclusion, hyaluronic acid targeted paclitaxel liposome can serve as a promising targeted formulation of paclitaxel for future cancer chemotherapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Liposomes as potential carrier system for targeted delivery of polyene antibiotics.

PubMed

Naik, Suresh R; Desai, Sandhya K; Shah, Priyank D; Wala, Santosh M

2013-09-01

The development of new therapeutic modalities involves the use of drug carrier, such as liposomes, which can modify pharmacokinetic and bio-distribution of drug profile. Polyene antibiotics incorporation into liposomes improves its availability at the site, bio-distribution and therapeutic index mainly through the engulfment of liposomes by circulating monocytes/macrophages and transportation to the site of infection. Polyene antibiotics (AmB, SJA-95, HA-1-92) and other antibiotics (streptomycin, tobramycin, quinolones, anti-tubercular and anti-cancer drugs), liposomal preparations are described with possible advantages from therapeutic efficacy and toxicity point of view. The polyene macrolide antibiotics liposomal preparations proved to be more effective in the treatment of systemic mycosis. The AmB-cyclodextrin derivatives inclusion complex is a major breakthrough in liposomal preparation which can be converted into aqueous phase of liposome. Liposomal drug incorporated preparation has been one of the important areas of research for developing the existing polyene antibiotics into useful chemotherapeutic agents in clinical medicine. In recent past other antibiotics have also been incorporated into liposomes using wide variety of materials, phosphatidylethanolamine derivatives (pegylated liposomes, enzyme sensitive conjugates, fluidosomes of anti-cancer drugs and poly lactic/glycolic acid microspheres for anti-tuberculosis drugs). In addition, attempts were also made to extend the receptor mediated drug targeting and to review some relevant patents.

Barriers to Liposomal Gene Delivery: from Application Site to the Target.

PubMed

Saffari, Mostafa; Moghimi, Hamid Reza; Dass, Crispin R

2016-01-01

Gene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. One promising form of gene delivery system (DDS) is liposomes. The success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. Liposomal gene delivery systems face different barriers from their site of application to their target, which is inside the cells. These barriers include presystemic obstacles (epithelial barriers), systemic barriers in blood circulation and cellular barriers. Epithelial barriers differ depending on the route of administration. Systemic barriers include enzymatic degradation, binding and opsonisation. Both of these barriers can act as limiting hurdles that genetic material and their vector should overcome before reaching the cells. Finally liposomes should overcome cellular barriers that include cell entrance, endosomal escape and nuclear uptake. These barriers and their impact on liposomal gene delivery will be discussed in this review.

HER2-targeted liposomal doxorubicin displays enhanced anti-tumorigenic effects without associated cardiotoxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, Joseph G.; Geretti, Elena; Hendriks, Bart S.

2012-07-01

Anthracycline-based regimens are a mainstay of early breast cancer therapy, however their use is limited by cardiac toxicity. The potential for cardiotoxicity is a major consideration in the design and development of combinatorial therapies incorporating anthracyclines and agents that target the HER2-mediated signaling pathway, such as trastuzumab. In this regard, HER2-targeted liposomal doxorubicin was developed to provide clinical benefit by both reducing the cardiotoxicity observed with anthracyclines and enhancing the therapeutic potential of HER2-based therapies that are currently available for HER2-overexpressing cancers. While documenting the enhanced therapeutic potential of HER2-targeted liposomal doxorubicin can be done with existing models, there hasmore » been no validated human cardiac cell-based assay system to rigorously assess the cardiotoxicity of anthracyclines. To understand if HER2-targeting of liposomal doxorubicin is possible with a favorable cardiac safety profile, we applied a human stem cell-derived cardiomyocyte platform to evaluate the doxorubicin exposure of human cardiac cells to HER2-targeted liposomal doxorubicin. To the best of our knowledge, this is the first known application of a stem cell-derived system for evaluating preclinical cardiotoxicity of an investigational agent. We demonstrate that HER2-targeted liposomal doxorubicin has little or no uptake into human cardiomyocytes, does not inhibit HER2-mediated signaling, results in little or no evidence of cardiomyocyte cell death or dysfunction, and retains the low penetration into heart tissue of liposomal doxorubicin. Taken together, this data ultimately led to the clinical decision to advance this drug to Phase I clinical testing, which is now ongoing as a single agent in HER2-expressing cancers. -- Highlights: ► Novel approach using stem cell-derived cardiomyocytes to assess preclinical safety. ► HER2-targeted liposomal doxorubicin has improved safety profile vs free

Design and syntheses of mono and multivalent mannosyl-lipoconjugates for targeted liposomal drug delivery.

PubMed

Štimac, Adela; Cvitaš, Jelena TrmĿiĿ; Frkanec, Leo; Vugrek, Oliver; Frkanec, Ruža

2016-09-10

Multivalent mannosyl-lipoconjugates may be of interest for glycosylation of liposomes and targeted drug delivery because the mannose specifically binds to C-type lectin receptors on the particular cells. In this paper syntheses of two types of novel O-mannosides are presented. Conjugates 1 and 2 with a COOH- and NH2-functionalized spacer and the connection to a lysine and FmocNH-PEG-COOH, are described. The coupling reactions of prepared intermediates 6 and 4 with a PEGylated-DSPE or palmitic acid, respectively, are presented. Compounds 5, mono-, 8, di- and 12, tetravalent mannosyl-lipoconjugates, were synthesized. The synthesized compounds were incorporated into liposomes and liposomal preparations featuring exposed mannose units were characterized. Carbohydrate liposomal quartz crystal microbalance based assay has been established for studying carbohydrate-lectin binding. It was demonstrated that liposomes with incorporated mannosyl-lipoconjugates were effectively recognized by Con A and have great potential to be used for targeted liposomal drug delivery systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Anti-MRSA malleable liposomes carrying chloramphenicol for ameliorating hair follicle targeting.

PubMed

Hsu, Ching-Yun; Yang, Shih-Chun; Sung, Calvin T; Weng, Yi-Han; Fang, Jia-You

2017-01-01

Pathogens usually invade hair follicles when skin infection occurs. The accumulated bacteria in follicles are difficult to eradicate. The present study aimed to assess the cutaneous and follicular delivery of chloramphenicol (Cm)-loaded liposomes and the antibacterial activity of these liposomes against methicillin-resistant Staphylococcus aureus (MRSA). Skin permeation was conducted by in vitro Franz diffusion cell. The anti-MRSA potential was checked using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), a well diffusion test, and intracellular MRSA killing. The classic, dimyristoylphosphatidylcholine (DMPC), and deoxycholic acid (DA) liposomes had a vesicle size of 98, 132, and 239 nm, respectively. The incorporation of DMPC or DA into the liposomes increased the bilayer fluidity. The malleable vesicles containing DMPC and DA showed increased follicular Cm uptake over the control solution by 1.5- and 2-fold, respectively. The MIC and MBC of DA liposomes loaded with Cm were 62.5 and 62.5-125 μg/mL, comparable to free Cm. An inhibition zone about 2-fold higher was achieved by DA liposomes as compared to the free control at a Cm dose of 0.5 mg/mL. DA liposomes also augmented antibacterial activity on keratinocyte-infected MRSA. The deformable liposomes had good biocompatibility against keratinocytes and neutrophils (viability >80%). In vivo administration demonstrated that DA liposomes caused negligible toxicity on the skin, based on physiological examination and histology. These data suggest the potential application of malleable liposomes for follicular targeting and the treatment of MRSA-infected dermatologic conditions.

Anti-MRSA malleable liposomes carrying chloramphenicol for ameliorating hair follicle targeting

PubMed Central

Sung, Calvin T; Weng, Yi-Han; Fang, Jia-You

2017-01-01

Pathogens usually invade hair follicles when skin infection occurs. The accumulated bacteria in follicles are difficult to eradicate. The present study aimed to assess the cutaneous and follicular delivery of chloramphenicol (Cm)-loaded liposomes and the antibacterial activity of these liposomes against methicillin-resistant Staphylococcus aureus (MRSA). Skin permeation was conducted by in vitro Franz diffusion cell. The anti-MRSA potential was checked using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), a well diffusion test, and intracellular MRSA killing. The classic, dimyristoylphosphatidylcholine (DMPC), and deoxycholic acid (DA) liposomes had a vesicle size of 98, 132, and 239 nm, respectively. The incorporation of DMPC or DA into the liposomes increased the bilayer fluidity. The malleable vesicles containing DMPC and DA showed increased follicular Cm uptake over the control solution by 1.5- and 2-fold, respectively. The MIC and MBC of DA liposomes loaded with Cm were 62.5 and 62.5–125 μg/mL, comparable to free Cm. An inhibition zone about 2-fold higher was achieved by DA liposomes as compared to the free control at a Cm dose of 0.5 mg/mL. DA liposomes also augmented antibacterial activity on keratinocyte-infected MRSA. The deformable liposomes had good biocompatibility against keratinocytes and neutrophils (viability >80%). In vivo administration demonstrated that DA liposomes caused negligible toxicity on the skin, based on physiological examination and histology. These data suggest the potential application of malleable liposomes for follicular targeting and the treatment of MRSA-infected dermatologic conditions. PMID:29184410

Development of a novel cyclic RGD peptide for multiple targeting approaches of liposomes to tumor region.

PubMed

Amin, Mohamadreza; Mansourian, Mercedeh; Koning, Gerben A; Badiee, Ali; Jaafari, Mahmoud Reza; Ten Hagen, Timo L M

2015-12-28

Liposomes containing cytotoxic agents and targeted with Arg-Gly-Asp based peptides have frequently been used against αvβ3 integrin on tumor neovasculature. However, like many other ligand modified liposomes these preparations suffered from enhanced uptake by the reticulo endothelial system (RES) and off-targeted interaction with integrin receptors vastly expressed in normal organs causing poor biodistribution and toxic effects. Here we mainly focus on development of a RGD-modified liposomal delivery system to enhance both targeting selectivity and tumor uptake. First, sterically stabilized liposomal doxorubicin (SSLD) prepared and decorated with cRGDfK and RGDyC peptides differ in their physical properties. Stability assessments as well as in vitro and in vivo studies revealed that increasing the peptide hydrophobicity promotes the therapeutic efficacy of RGD-SSLD in a C-26 tumor model due to decreased recognition by RES and opsonization and limited off-targeted interactions. Then a novel N-methylated RGD peptide was designed and its capability in targeting integrin presenting cells was comprehensively assessed both in vitro and in vivo. RGDf[N-methyl]C promotes the liposome internalization by HUVEC via integrin mediated endocytosis. Intravital microscopy in window chamber bearing mice illustrated the capability of RGDf[N-methyl]C-liposomes in targeting both tumor vasculature and tumor cells in murine B16F0 and human BLM tumor models. Quantitative biodistribution in mice bearing B16F0 tumor revealed its high affinity to tumor with no considerable affinity to normal organs. Treatment by high dose of RGDf[N-methyl]C-SSLD was found more effective than non-targeted SSLD and no toxic side effect was observed. In conclusion, the RGDf[N-methyl]C-liposome was found promising in targeting tumor vasculature as well as other cells inside the tumor. Copyright © 2015 Elsevier B.V. All rights reserved.

Prostate-specific membrane antigen-targeted liposomes specifically deliver the Zn(2+) chelator TPEN inducing oxidative stress in prostate cancer cells.

PubMed

Stuart, Christopher H; Singh, Ravi; Smith, Thomas L; D'Agostino, Ralph; Caudell, David; Balaji, K C; Gmeiner, William H

2016-05-01

To evaluate the potential use of zinc chelation for prostate cancer therapy using a new liposomal formulation of the zinc chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)-ethylenediamine (TPEN). TPEN was encapsulated in nontargeted liposomes or liposomes displaying an aptamer to target prostate cancer cells overexpression prostate-specific membrane antigen. The prostate cancer selectivity and therapeutic efficacy of liposomal (targeted and nontargeted) and free TPEN were evaluated in vitro and in tumor-bearing mice. TPEN chelates zinc and results in reactive oxygen species imbalance leading to cell death. Delivery of TPEN using aptamer-targeted liposomes results in specific delivery to targeted cells. In vivo experiments show that TPEN-loaded, aptamer-targeted liposomes reduce tumor growth in a human prostate cancer xenograft model.

Minimizing antibody surface density on liposomes while sustaining cytokine-activated EC targeting.

PubMed

Almeda, Dariela; Wang, Biran; Auguste, Debra T

2015-02-01

Liposomes may be engineered to target inflamed endothelium by mimicking ligand-receptor interactions between leukocytes and cytokine-activated endothelial cells (ECs). The upregulation and assembly of vascular cell adhesion molecule-1 (VCAM1) and E-selectin on the cell membrane upon exposure to cytokines have shown potential for drug delivery vehicles to target sites of chronic endothelial inflammation, such as atherosclerosis and cancer. Herein, we characterized EC surfaces by measuring the E-selectin and VCAM1 surface densities and adhesion forces of aVCAM1 and aE-selectin to ECs. We quantified the antibody density, ratio, and diffusivity of liposomes to achieve significant binding and internalization. At 1 h, the 1:1 ratio of VCAM1:E-selectin antibodies was significantly higher than 1:0 and 0:1. Significant binding and uptake was achieved at aE-selectin densities as low as 400 molecules/μm(2). The highest levels of binding and uptake were achieved when using a 1:1 ratio of VCAM1:E-selectin antibodies at a density of 1000 molecules/μm(2); this density is 85% lower than previous reports. The binding and uptake of functionalized liposomes were reduced to levels comparable to IgG functionalized liposomes upon a 10-fold reduction in liposome membrane diffusivity. We conclude with a liposomal design that discriminates between healthy and inflamed endothelium while reducing antibody surface presentation. Copyright © 2014 Elsevier Ltd. All rights reserved.

MRI contrast agent for targeting glioma: interleukin-13 labeled liposome encapsulating gadolinium-DTPA

PubMed Central

Liu, Xiaoli; Madhankumar, Achuthamangalam B.; Miller, Patti A.; Duck, Kari A.; Hafenstein, Susan; Rizk, Elias; Slagle-Webb, Becky; Sheehan, Jonas M.; Connor, James R.; Yang, Qing X.

2016-01-01

Background Detection of glioma with MRI contrast agent is limited to cases in which the blood-brain barrier (BBB) is compromised as contrast agents cannot cross the BBB. Thus, an early-stage infiltrating tumor is not detectable. Interleukin-13 receptor alpha 2 (IL-13Rα2), which has been shown to be overexpressed in glioma, can be used as a target moiety. We hypothesized that liposomes conjugated with IL-13 and encapsulating MRI contrast agent are capable of passing through an intact BBB and producing MRI contrast with greater sensitivity. Methods The targeted MRI contrast agent was created by encapsulating Magnevist (Gd-DTPA) into liposomes conjugated with IL-13 and characterized by particle size distribution, cytotoxicity, and MRI relaxivity. MR image intensity was evaluated in the brain in normal mice post injection of Gd-DTPA and IL-13-liposome-Gd-DTPA one day apart. The specificity for glioma detection by IL-13-liposome-Gd-DTPA was demonstrated in an intracranial glioma mouse model and validated histologically. Results The average size of IL-13-liposome-Gd-DTPA was 137 ± 43 nm with relaxivity of 4.0 ± 0.4 L/mmole-s at 7 Tesla. No significant cytotoxicity was observed with MTS assay and serum chemistry in mice. The MRI signal intensity was enhanced up to 15% post injection of IL-13-liposome-Gd-DTPA in normal brain tissue following a similar time course as that for the pituitary gland outside of the BBB. MRI enhanced by IL-13-liposome-Gd-DTPA detected small tumor masses in addition to those seen with Magnevist-enhanced MRI. Conclusions IL-13-liposome-Gd-DTPA is able to pass through the uncompromised BBB and detect an early stage glioma that cannot be seen with conventional contrast-enhanced MRI. PMID:26519740

Targeting to cells of fluorescent liposomes covalently coupled with monoclonal antibody or protein A

NASA Astrophysics Data System (ADS)

Leserman, Lee D.; Barbet, Jacques; Kourilsky, François; Weinstein, John N.

1980-12-01

Many applications envisioned for liposomes in cell biology and chemotherapy require their direction to specific cellular targets1-3. The ability to use antibody as a means of conferring specificity to liposomes would markedly increase their usefulness. We report here a method for covalently coupling soluble proteins, including monoclonal antibody and Staphylococcus aureus protein A (ref. 4), to small sonicated liposomes, by using the heterobifunctional cross-linking reagent N-hydroxysuccinimidyl 3-(2-pyridyldithio)propionate (SPDP, Pharmacia). Liposomes bearing covalently coupled mouse monoclonal antibody against human β2-microglobulin [antibody B1.1G6 (IgG2a, κ) (B. Malissen et al., in preparation)] bound specifically to human, but not to mouse cells. Liposomes bearing protein A became bound to human cells previously incubated with the B1.1G6 antibody, but not to cells incubated without antibody. The coupling method results in efficient binding of protein to the liposomes without aggregation and without denaturation of the coupled ligand; at least 60% of liposomes bound functional protein. Further, liposomes did not leak encapsulated carboxyfluorescein (CF) as a consequence of the reaction.

Theranostic liposomes loaded with quantum dots and apomorphine for brain targeting and bioimaging

PubMed Central

Wen, Chih-Jen; Zhang, Li-Wen; Al-Suwayeh, Saleh A; Yen, Tzu-Chen; Fang, Jia-You

2012-01-01

Quantum dots (QDs) and apomorphine were incorporated into liposomes to eliminate uptake by the liver and enhance brain targeting. We describe the preparation, physicochemical characterization, in vivo bioimaging, and brain endothelial cell uptake of the theranostic liposomes. QDs and the drug were mainly located in the bilayer membrane and inner core of the liposomes, respectively. Spherical vesicles with a mean diameter of ~140 nm were formed. QDs were completely encapsulated by the vesicles. Nearly 80% encapsulation percentage was achieved for apomorphine. A greater fluorescence intensity was observed in mouse brains treated with liposomes compared to free QDs. This result was further confirmed by ex vivo imaging of the organs. QD uptake by the heart and liver was reduced by liposomal incorporation. Apomorphine accumulation in the brain increased by 2.4-fold after this incorporation. According to a hyperspectral imaging analysis, multifunctional liposomes but not the aqueous solution carried QDs into the brain. Liposomes were observed to have been efficiently endocytosed into bEND3 cells. The mechanisms involved in the cellular uptake were clathrin- and caveola-mediated endocytosis, which were energy-dependent. To the best of our knowledge, our group is the first to develop liposomes with a QD-drug hybrid for the aim of imaging and treating brain disorders. PMID:22619515

Theranostic liposomes loaded with quantum dots and apomorphine for brain targeting and bioimaging.

PubMed

Wen, Chih-Jen; Zhang, Li-Wen; Al-Suwayeh, Saleh A; Yen, Tzu-Chen; Fang, Jia-You

2012-01-01

Quantum dots (QDs) and apomorphine were incorporated into liposomes to eliminate uptake by the liver and enhance brain targeting. We describe the preparation, physicochemical characterization, in vivo bioimaging, and brain endothelial cell uptake of the theranostic liposomes. QDs and the drug were mainly located in the bilayer membrane and inner core of the liposomes, respectively. Spherical vesicles with a mean diameter of ~140 nm were formed. QDs were completely encapsulated by the vesicles. Nearly 80% encapsulation percentage was achieved for apomorphine. A greater fluorescence intensity was observed in mouse brains treated with liposomes compared to free QDs. This result was further confirmed by ex vivo imaging of the organs. QD uptake by the heart and liver was reduced by liposomal incorporation. Apomorphine accumulation in the brain increased by 2.4-fold after this incorporation. According to a hyperspectral imaging analysis, multifunctional liposomes but not the aqueous solution carried QDs into the brain. Liposomes were observed to have been efficiently endocytosed into bEND3 cells. The mechanisms involved in the cellular uptake were clathrin- and caveola-mediated endocytosis, which were energy-dependent. To the best of our knowledge, our group is the first to develop liposomes with a QD-drug hybrid for the aim of imaging and treating brain disorders.

Amadori-glycated phosphatidylethanolamine enhances the physical stability and selective targeting ability of liposomes

PubMed Central

Miyazawa, Taiki; Kamiyoshihara, Reina; Shimizu, Naoki; Harigae, Takahiro; Otoki, Yurika; Ito, Junya; Kato, Shunji; Miyazawa, Teruo

2018-01-01

Liposomes consisting of 100% phosphatidylcholine exhibit poor membrane fusion, cellular uptake and selective targeting capacities. To overcome these limitations, we used Amadori-glycated phosphatidylethanolamine, which is universally present in animals and commonly consumed in foods. We found that liposomes containing Amadori-glycated phosphatidylethanolamine exhibited significantly reduced negative membrane potential and demonstrated high cellular uptake. PMID:29515844

Micromixer Based Preparation of Functionalized Liposomes and Targeting Drug Delivery

PubMed Central

2016-01-01

We present here a specific targeting nanocarrier system by functionalization of liposomes with one new type of breast cancer targeting peptide (H6, YLFFVFER) by a micromixer with high efficiency. Antitumor drugs could be successfully delivered into human epidermal growth factor receptor 2 (HER2) positive breast cancer cells with high efficiency in both in vivo and ex vivo models. PMID:27096054

Micromixer Based Preparation of Functionalized Liposomes and Targeting Drug Delivery.

PubMed

Jia, Xiangqian; Wang, Weizhi; Han, Qiuju; Wang, Zihua; Jia, Yunhong; Hu, Zhiyuan

2016-04-14

We present here a specific targeting nanocarrier system by functionalization of liposomes with one new type of breast cancer targeting peptide (H6, YLFFVFER) by a micromixer with high efficiency. Antitumor drugs could be successfully delivered into human epidermal growth factor receptor 2 (HER2) positive breast cancer cells with high efficiency in both in vivo and ex vivo models.

NGR-modified pH-sensitive liposomes for controlled release and tumor target delivery of docetaxel.

PubMed

Gu, Zili; Chang, Minglu; Fan, Yang; Shi, Yanbin; Lin, Guimei

2017-12-01

As current tumor chemotherapy faces many challenges, it is important to develop drug delivery systems with increased tumor-targeting ability, enhanced therapeutic effects and reduced side effects. In this study, a pH-sensitive liposome was constructed containing CHEMS-anchored PEG2000 for extended circulation and NGR peptide as the targeting moiety. The NGR-modified docetaxel-loaded pH-sensitive extended-circulation liposomes (DTX/NGR-PLL) prepared possess suitable physiochemical properties, including particle size of approximately 200nm, drug encapsulation efficiency of approximately 70%, and pH-sensitive drug release properties. Experiments performed in vitro and in vivo on human fibrosarcoma cells (HT-1080) and human breast adenocarcinoma cells (MCF-7) verified the specific targeting ability and enhanced antitumor activity to HT-1080 cells. The results of intravenous administration demonstrated that NGR-modified liposomes can significantly and safely accumulate in tumor tissue in xenografted nude mice. In conclusion, the liposomes constructed hold promise as a safe and efficient drug delivery system for specific tumor treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Hyaluronan polymer length, grafting density, and surface poly(ethylene glycol) coating influence in vivo circulation and tumor targeting of hyaluronan-grafted liposomes.

PubMed

Qhattal, Hussaini Syed Sha; Hye, Tanvirul; Alali, Amer; Liu, Xinli

2014-06-24

Hyaluronan-grafted liposomes (HA-liposomes) preferentially target CD44-overexpressing tumor cells in vitro via receptor-mediated endocytosis. We investigated the pharmacokinetics and biodistribution of HA-liposomes with various sizes of HA (MW 5-8, 50-60, and 175-350 kDa) in mice. Incorporation of negatively charged HA on the liposome surface compromised its blood circulation time, which led to decreased tumor accumulation in CD44+ human breast cancer MDA-MB-231 xenografts compared to PEGylated liposomes (PEG-5000). Clearance of HA-liposomes was HA polymer length-dependent; high MW (175-350 kDa, highest ligand binding affinity) HA-liposomes displayed faster clearance compared to low MW (5-8, 50-60 kDa) HA-liposomes or PEGylated liposomes. Surface HA ligand density can also affect clearance of HA-liposomes. Thus, HA is not an effective stealth coating material. When dual coating of PEG and HA was used, the PEG-HA-liposomes displayed similar blood circulation time and tumor accumulation to that of the PEGylated liposomes; however, the PEG-HA-liposomes displayed better cellular internalization capability in vivo. Tumor histology showed that PEG-HA-liposomes had a more direct association with CD44+ cancer cells, while PEGylated liposomes located predominantly in the tumor periphery, with less association with CD44+ cells. Flow cytometry analysis of ex vivo tumor cells showed that PEG-HA-liposomes had significantly higher tumor cell internalization compared to PEGylated liposomes. This study demonstrates that a long blood circulation time is critical for active tumor targeting. Furthermore, the use of the tumor-targeting ligand HA does not increase total tumor accumulation of actively targeted liposomes in solid tumors; however, it can enhance intracellular delivery.

MRI contrast agent for targeting glioma: interleukin-13 labeled liposome encapsulating gadolinium-DTPA.

PubMed

Liu, Xiaoli; Madhankumar, Achuthamangalam B; Miller, Patti A; Duck, Kari A; Hafenstein, Susan; Rizk, Elias; Slagle-Webb, Becky; Sheehan, Jonas M; Connor, James R; Yang, Qing X

2016-05-01

Detection of glioma with MRI contrast agent is limited to cases in which the blood-brain barrier (BBB) is compromised as contrast agents cannot cross the BBB. Thus, an early-stage infiltrating tumor is not detectable. Interleukin-13 receptor alpha 2 (IL-13Rα2), which has been shown to be overexpressed in glioma, can be used as a target moiety. We hypothesized that liposomes conjugated with IL-13 and encapsulating MRI contrast agent are capable of passing through an intact BBB and producing MRI contrast with greater sensitivity. The targeted MRI contrast agent was created by encapsulating Magnevist (Gd-DTPA) into liposomes conjugated with IL-13 and characterized by particle size distribution, cytotoxicity, and MRI relaxivity. MR image intensity was evaluated in the brain in normal mice post injection of Gd-DTPA and IL-13-liposome-Gd-DTPA one day apart. The specificity for glioma detection by IL-13-liposome-Gd-DTPA was demonstrated in an intracranial glioma mouse model and validated histologically. The average size of IL-13-liposome-Gd-DTPA was 137 ± 43 nm with relaxivity of 4.0 ± 0.4 L/mmole-s at 7 Tesla. No significant cytotoxicity was observed with MTS assay and serum chemistry in mice. The MRI signal intensity was enhanced up to 15% post injection of IL-13-liposome-Gd-DTPA in normal brain tissue following a similar time course as that for the pituitary gland outside of the BBB. MRI enhanced by IL-13-liposome-Gd-DTPA detected small tumor masses in addition to those seen with Magnevist-enhanced MRI. IL-13-liposome-Gd-DTPA is able to pass through the uncompromised BBB and detect an early stage glioma that cannot be seen with conventional contrast-enhanced MRI. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Peptide-modified liposomes for selective targeting of bombesin receptors overexpressed by cancer cells: a potential theranostic agent

PubMed Central

Accardo, Antonella; Salsano, Giuseppina; Morisco, Anna; Aurilio, Michela; Parisi, Antonio; Maione, Francesco; Cicala, Carla; Tesauro, Diego; Aloj, Luigi; De Rosa, Giuseppe; Morelli, Giancarlo

2012-01-01

Objectives Drug delivery systems consisting of liposomes displaying a cell surface receptor-targeting peptide are being developed to specifically deliver chemotherapeutic drugs to tumors overexpressing a target receptor. This study addresses novel liposome composition approaches to specifically target tissues overexpressing bombesin (BN) receptors. Methods A new amphiphilic peptide derivative (MonY-BN) containing the BN(7–14) peptide, the DTPA (diethylenetriaminepentaacetate) chelating agent, a hydrophobic moiety with two C18 alkyl chains, and polyethylene glycol spacers, has been synthesized by solid-phase methods. Liposomes have been generated by co-aggregation of MonY-BN with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). The structural and biological properties of these new target-selective drug-delivery systems have been characterized. Results Liposomes with a DSPC/MonY-BN (97/3 molar ratio) composition showed a diameter of 145.5 ± 31.5 nm and a polydispersity index of 0.20 ± 0.05. High doxorubicin (Dox) loading was obtained with the remote pH gradient method using citrate as the inner buffer. Specific binding to PC-3 cells of DSPC/MonY-BN liposomes was obtained (2.7% ± 0.3%, at 37°C), compared with peptide-free DSPC liposomes (1.4% ± 0.2% at 37°C). Incubation of cells with DSPC/ MonY-BN/Dox showed significantly lower cell survival compared with DSPC/Dox-treated cells, in the presence of 100 ng/mL and 300 ng/mL drug amounts, in cytotoxicity experiments. Intravenous treatment of PC-3 xenograft-bearing mice with DSPC/MonY-BN/Dox at 10 mg/kg Dox dose produced higher tumour growth inhibition (60%) compared with nonspecific DSPC/ Dox liposomes (36%) relative to control animals. Conclusion The structural and loading properties of DSPC/MonY-BN liposomes along with the observed in-vitro and in-vivo activity are encouraging for further development of this approach for target-specific cancer chemotherapy. PMID:22619538

Multifunctional targeting vinorelbine plus tetrandrine liposomes for treating brain glioma along with eliminating glioma stem cells

PubMed Central

Li, Xue-tao; Tang, Wei; Jiang, Ying; Wang, Xiao-min; Wang, Yan-hong; Cheng, Lan; Meng, Xian-sheng

2016-01-01

Malignant brain glioma is the most lethal and aggressive type of cancer. Surgery and radiotherapy cannot eliminate all glioma stem cells (GSCs) and blood–brain barrier (BBB) restricts the movement of antitumor drugs from blood to brain, thus leading to the poor prognosis with high recurrence rate. In the present study, the targeting conjugates of cholesterol polyethylene glycol polyethylenimine (CHOL-PEG2000-PEI) and D-a-tocopheryl polyethylene glycol 1000 succinate vapreotide (TPGS1000-VAP) were newly synthesized for transporting drugs across the BBB and targeting glioma cells and GSCs. The multifunctional targeting vinorelbine plus tetrandrine liposomes were constructed by modifying the targeting conjugates. The studies were undertaken on BBB model, glioma cells, GSCs, and glioma-bearing mice. In vitro results showed that multifunctional targeting drugs-loaded liposomes with suitable physicochemical property could enhance the transport drugs across the BBB, increase the intracellular uptake, inhibit glioma cells and GSCs, penetrate and destruct the GSCs spheroids, and induce apoptosis via activating related apoptotic proteins. In vivo results demonstrated that multifunctional targeting drugs-loaded liposomes could significantly accumulate into brain tumor location, show the specificity to tumor sites, and result in a robust overall antitumor efficacy in glioma-bearing mice. These data suggested that the multifunctional targeting vinorelbine plus tetrandrine liposomes could offer a promising strategy for treating brain glioma. PMID:27029055

Glioma targeted delivery strategy of doxorubicin-loaded liposomes by dual-ligand modification.

PubMed

Han, Wei; Yin, Guangfu; Pu, Ximing; Chen, Xianchun; Liao, Xiaoming; Huang, Zhongbing

2017-10-01

The blood-brain barrier (BBB) is the protective parclose of brain safety, but it is also the main obstacle of the drug delivery to cerebral parenchyma, which hamper therapy for brain diseases. In this work, a glioma targeted drug delivery system was developed through loading doxorubicin into Angiopep-2 and TAT peptide dual-modified liposomes (DOX-TAT-Ang-LIP). Low-density lipoprotein receptor-related protein-1 (LRP1) was one receptor overexpressed on both BBB and glioma cytomembranes. Angiopep-2, a specific ligand of LRP1, exhibited high LRP1 binding efficiency. Additionally, TAT could penetrate through cell membranes without selectivity via an unsaturated pathway. To avoid the receptor saturation of Angiopep-2, TAT was also conjugated on the surface of liposomes, providing that the liposomes not only have effective BBB penetrating effect, but also have the glioma targeting function. The prepared DOX liposomes appeared good stability and narrow dispersity in serum with a diameter of 90 nm, and exhibited sustained DOX release behaviors. The conjunctions of Angiopep-2 and TAT were confirmed by 1 H NMR spectra. The BBB model, cellular uptake observations, antiproliferation study, and the cell ultrastructure analyses suggested that DOX-TAT-Ang-LIP could not only penetrate through BBB via transcytosis, but also concentrate in glioma, then enter into glioma cells and finally result in the necrosis of glioma cells.

Lymphatic-targeted cationic liposomes: a robust vaccine adjuvant for promoting long-term immunological memory.

PubMed

Wang, Ce; Liu, Peng; Zhuang, Yan; Li, Ping; Jiang, Boling; Pan, Hong; Liu, Lanlan; Cai, Lintao; Ma, Yifan

2014-09-22

Although retaining antigens at the injection site (the so-called "depot effect") is an important strategy for vaccine development, increasing evidence showed that lymphatic-targeted vaccine delivery with liposomes could be a promising approach for improving vaccine efficacy. However, it remains unclear whether antigen depot or lymphatic targeting would benefit long-term immunological memory, a major determinant of vaccine efficacy. In the present study, OVA antigen was encapsulated with DOTAP cationic liposomes (LP) or DOTAP-PEG-mannose liposomes (LP-Man) to generate depot or lymphatic-targeted liposome vaccines, respectively. The result of in vivo imaging showed that LP mostly accumulated near the injection site, whereas LP-Man not only effectively accumulated in draining lymph nodes (LNs) and the spleen, but also enhanced the uptake by resident antigen-presenting cells. Although LP vaccines with depot effect induced anti-OVA IgG more potently than LP-Man vaccines did on day 40 after priming, they failed to mount an effective B-cell memory response upon OVA re-challenge after three months. In contrast, lymphatic-targeted LP-Man vaccines elicited sustained antibody production and robust recall responses three months after priming, suggesting lymphatic targeting rather than antigen depot promoted the establishment of long-term memory responses. The enhanced long-term immunological memory by LP-Man was attributed to vigorous germinal center responses as well as increased Tfh cells and central memory CD4(+) T cells in the secondary lymphoid organs. Hence, lymphatic-targeted vaccine delivery with LP-Man could be an effective strategy to promote long-lasting immunological memory. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fasudil and SOD packaged in peptide-studded-liposomes: Properties, pharmacokinetics and ex-vivo targeting to isolated perfused rat lungs.

PubMed

Gupta, Nilesh; Al-Saikhan, Fahad I; Patel, Brijeshkumar; Rashid, Jahidur; Ahsan, Fakhrul

2015-07-05

The present study investigated the feasibility of encapsulating two drugs, fasudil and superoxide dismutase (SOD), into liposomes for targeted and inhalational delivery to the pulmonary vasculature to treat pulmonary arterial hypertension (PAH). Nanosized liposomes were prepared by a thin-film formation and extrusion method, and the drugs were encapsulated by a modified freeze-thaw technique. The peptide CARSKNKDC (CAR), a pulmonary-specific targeting sequence, was conjugated on the surface of liposomes. Formulations were optimized for various physicochemical properties, tested for their ex-vivo and in-vivo drug absorption after intratracheal administration, and evaluated for short-term safety in healthy rats. The homogenous nanosized liposomes contained both SOD (~55% entrapment) and fasudil (~40% entrapment), and were stable at 4°C and after nebulization. Liposomes released the drugs in a controlled-release fashion. Compared with plain liposomes, CAR-liposomes increased the uptake by pulmonary endothelial and smooth muscle cells by ~2-fold. CAR-liposomes extended the biological half-lives of SOD and fasudil by ~3-fold. Ex-vivo studies demonstrated that CAR-liposomes were better retained in the lungs than plain liposomes. Bronchoalveolar lavage studies indicated the safety of peptide-equipped liposomes as pulmonary delivery carriers. Overall, this study demonstrates that CAR-liposomes may be used as inhalational carriers for SOD plus fasudil-based combination therapy for PAH. Published by Elsevier B.V.

Synthesis of a novel galactosylated lipid and its application to the hepatocyte-selective targeting of liposomal doxorubicin.

PubMed

Wang, Shao-Ning; Deng, Yi-Hui; Xu, Hui; Wu, Hong-Bing; Qiu, Ying-Kun; Chen, Da-Wei

2006-01-01

This paper described the synthesis of a novel galactosylated lipid with mono-galactoside moiety, (5-Cholesten-3beta-yl) 4-oxo-4-[2-(lactobionyl amido) ethylamido] butanoate (CHS-ED-LA), and the targetability of doxorubicin (DOX), a model drug, in liposomes containing 10% mol/mol CHS-ED-LA (galactosylated liposomes, GalL) to the liver was studied. The weighted-average overall drug targeting efficiency (Te(*)) was used to evaluate the liver targetability of GalL DOX. The results showed that GalL DOX gave a relatively high (Te(*))(liver) value of 64.6%, while DOX in conventional liposome (CL DOX) only gave a (Te(*))(liver) value of 21.8%. In the liver, the GalL DOX was mainly taken up by parenchymal cells (88% of the total hepatic uptake). Moreover, preinjection of asialofetuin significantly inhibited the liver uptake of GalL DOX (from 70 to 12% of the total injected dose). It was suggested that liposomes containing such novel galactosylated lipid, CHS-ED-LA, had a great potential as drug delivery carriers for hepatocyte-selective targeting.

Paramagnetic and fluorescent liposomes for target-specific imaging and therapy of tumor angiogenesis

PubMed Central

Kluza, Ewelina; Van Tilborg, Geralda A. F.; van der Schaft, Daisy W. J.; Griffioen, Arjan W.; Mulder, Willem J. M.; Nicolay, Klaas

2010-01-01

Angiogenesis is essential for tumor growth and metastatic potential and for that reason considered an important target for tumor treatment. Noninvasive imaging technologies, capable of visualizing tumor angiogenesis and evaluating the efficacy of angiostatic therapies, are therefore becoming increasingly important. Among the various imaging modalities, magnetic resonance imaging (MRI) is characterized by a superb spatial resolution and anatomical soft-tissue contrast. Revolutionary advances in contrast agent chemistry have delivered versatile angiogenesis-specific molecular MRI contrast agents. In this paper, we review recent advances in the preclinical application of paramagnetic and fluorescent liposomes for noninvasive visualization of the molecular processes involved in tumor angiogenesis. This liposomal contrast agent platform can be prepared with a high payload of contrast generating material, thereby facilitating its detection, and is equipped with one or more types of targeting ligands for binding to specific molecules expressed at the angiogenic site. Multimodal liposomes endowed with contrast material for complementary imaging technologies, e.g., MRI and optical, can be exploited to gain important preclinical insights into the mechanisms of binding and accumulation at angiogenic vascular endothelium and to corroborate the in vivo findings. Interestingly, liposomes can be designed to contain angiostatic therapeutics, allowing for image-supervised drug delivery and subsequent monitoring of therapeutic efficacy. PMID:20390447

Destruction of vasculogenic mimicry channels by targeting epirubicin plus celecoxib liposomes in treatment of brain glioma

PubMed Central

Ju, Rui-Jun; Zeng, Fan; Liu, Lei; Mu, Li-Min; Xie, Hong-Jun; Zhao, Yao; Yan, Yan; Wu, Jia-Shuan; Hu, Ying-Jie; Lu, Wan-Liang

2016-01-01

The efficacy of chemotherapy for brain glioma is restricted by the blood–brain barrier (BBB), and surgery or radiotherapy cannot eliminate the glioma cells because of their unique location. Residual brain glioma cells can form vasculogenic mimicry (VM) channels that can cause a recurrence of brain glioma. In the present study, targeting liposomes incorporating epirubicin and celecoxib were prepared and used for the treatment of brain glioma, along with the destruction of their VM channels. Evaluations were performed on the human brain glioma U87MG cells in vitro and on intracranial brain glioma-bearing nude mice. Targeting epirubicin plus celecoxib liposomes in the circulatory blood system were able to be transported across the BBB, and accumulated in the brain glioma region. Then, the liposomes were internalized by brain glioma cells and killed glioma cells by direct cytotoxic injury and the induction of apoptosis. The induction of apoptosis was related to the activation of caspase-8- and -3-signaling pathways, the activation of the proapoptotic protein Bax, and the suppression of the antiapoptotic protein Mcl-1. The destruction of brain glioma VM channels was related to the downregulation of VM channel-forming indictors, which consisted of MMP-2, MMP-9, FAK, VE-Cad, and VEGF. The results demonstrated that the targeting epirubicin plus celecoxib liposomes were able to effectively destroy the glioma VM channels and exhibited significant efficacy in the treatment of intracranial glioma-bearing nude mice. Therefore, targeting epirubicin plus celecoxib liposomes could be a potential nanostructured formulation to treat gliomas and destroy their VM channels. PMID:27042063

The effect of lonidamine (LND) on radiation and thermal responses of human and rodent cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raaphorst, G.P.; Feeley, M.M.; Danjoux, C.E.

1991-03-01

Rodent and human cells were tested for response to Lonidamine (LND) (1-(2,4 dichlorobenzyl) 1-indazol-3-carboxylic acid) combined with radiation or hyperthermia. Lonidamine exposure before, during, and after irradiation caused varying degrees of inhibition of potentially lethal damage (PLD) repair which was cell line dependent. In human glioma, melanoma, squamous cell carcinoma, and fibroblasts, LND exposure did not inhibit or only partially inhibited repair of potentially lethal damage. LND up to 100 micrograms/ml produced only a low level of toxicity in these cells and only slightly inhibited glucose consumption at the maximum concentration. In human glioma cells, LND treatment alone did notmore » inhibit PLD repair, but when combined with hyperthermia treatment at moderate levels easily achievable in the clinic, there was complete inhibition of potentially lethal damage repair. These data suggest that LND effectiveness is cell type dependent. Combinations of LND, hyperthermia, and radiation may be effective in cancer therapy especially in tumors such as glioma in which repair of potentially lethal damage may be extensive.« less

Cyclic RGD peptide-modified liposomal drug delivery system for targeted oral apatinib administration: enhanced cellular uptake and improved therapeutic effects.

PubMed

Song, Zhiwang; Lin, Yun; Zhang, Xia; Feng, Chan; Lu, Yonglin; Gao, Yong; Dong, Chunyan

2017-01-01

Apatinib is an oral tyrosine kinase inhibitor, which selectively targets vascular endothelial growth factor receptor 2 and has the potential to treat many tumors therapeutically. Cyclic arginylglycylaspartic acid (cRGD)- and polyethylene glycol (PEG)-modified liposomes (cRGD-Lipo-PEG) were constructed to act as a targeted delivery system for the delivery of apatinib to the human colonic cancer cell line, HCT116. These cRGD-modified liposomes specifically recognized integrin α v β 3 and exhibited greater uptake efficiency with respect to delivering liposomes into HCT116 cells when compared to nontargeted liposomes (Lipo-PEG), as well as greater death of tumor cells and apoptosis. The mechanism by which cRGD-Lipo-PEG targets cells was elucidated further with competition assays. To determine the anticancer efficacy in vivo, nude mice were implanted with HCT116 xenografts and treated with apatinib-loaded liposomes or free apatinib intravenously or via intragastric administration. The active and passive targeting of cRGD-Lipo-PEG led to significant tumor treatment targeting ability, better inhibition of tumor growth, and less toxicity when compared with treatments using uncombined apatinib. The results presented strongly support the case for cRGD-Lipo-PEG representing a targeted delivery system for apatinib in the treatment of colonic cancer.

Cyclic RGD peptide-modified liposomal drug delivery system for targeted oral apatinib administration: enhanced cellular uptake and improved therapeutic effects

PubMed Central

Song, Zhiwang; Lin, Yun; Zhang, Xia; Feng, Chan; Lu, Yonglin; Gao, Yong; Dong, Chunyan

2017-01-01

Apatinib is an oral tyrosine kinase inhibitor, which selectively targets vascular endothelial growth factor receptor 2 and has the potential to treat many tumors therapeutically. Cyclic arginylglycylaspartic acid (cRGD)- and polyethylene glycol (PEG)-modified liposomes (cRGD-Lipo-PEG) were constructed to act as a targeted delivery system for the delivery of apatinib to the human colonic cancer cell line, HCT116. These cRGD-modified liposomes specifically recognized integrin αvβ3 and exhibited greater uptake efficiency with respect to delivering liposomes into HCT116 cells when compared to nontargeted liposomes (Lipo-PEG), as well as greater death of tumor cells and apoptosis. The mechanism by which cRGD-Lipo-PEG targets cells was elucidated further with competition assays. To determine the anticancer efficacy in vivo, nude mice were implanted with HCT116 xenografts and treated with apatinib-loaded liposomes or free apatinib intravenously or via intragastric administration. The active and passive targeting of cRGD-Lipo-PEG led to significant tumor treatment targeting ability, better inhibition of tumor growth, and less toxicity when compared with treatments using uncombined apatinib. The results presented strongly support the case for cRGD-Lipo-PEG representing a targeted delivery system for apatinib in the treatment of colonic cancer. PMID:28331317

Modifying glycyrrhetinic acid liposomes with liver-targeting ligand of galactosylated derivative: preparation and evaluations

PubMed Central

Cheng, Yi; Gao, Youheng; Zheng, Pinjing; Li, Chuangnan; Tong, Yidan; Li, Zhao; Luo, Wenhui; Chen, Zhao

2017-01-01

In this study, novel glycyrrhetinic acid (GA) liposomes modified with a liver-targeting galactosylated derivative ligand (Gal) were prepared using a film-dispersion method. To characterize the samples, particle size, zeta potential, drug loading, and encapsulation efficiency were performed. Moreover, plasma and tissues were pre-treated by liquid-liquid extraction and analyzed by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that the mean residence times (MRTs) and the area under the curve (AUC) of GA liposomes with Gal (Gal-GA-LP), and GA liposomes (GA-LP) were higher than the GA solution (GA-S) in plasma. The tissue (liver) distribution of Gal-GA-LP was significantly different in contrast to GA-LP. The relative intake rate (Re) of Gal-GA-LP and GA-LP in the liver was 4.752 and 2.196, respectively. The peak concentration ratio (Ce) of Gal-GA-LP and GA-LP in the liver was 2.796 and 1.083, respectively. The targeting efficiency (Te) of Gal-GA-LP and GA-LP in the liver was 48.193% and 34.718%, respectively. Taken together, the results indicate that Gal-GA-LP is an ideal complex for liver-targeting, and has great potential application in the clinical treatment of hepatic diseases. Drug loading and releasing experiments also indicated that most liposomes are spherical structures and have good dispersity under physiologic conditions, which could prolong GA release efficiency in vitro. PMID:29254224

Characterization of cationic liposome formulations designed to exhibit extended plasma residence times and tumor vasculature targeting properties.

PubMed

Ho, Emmanuel A; Ramsay, Euan; Ginj, Mihaela; Anantha, Malathi; Bregman, Isaiah; Sy, Jonathan; Woo, Janet; Osooly-Talesh, Maryam; Yapp, Donald T; Bally, Marcel B

2010-06-01

Cationic liposomes exhibit a propensity to selectively target tumor-associated blood vessels demonstrating potential value as anti-cancer drug delivery vehicles. Their utility however, is hampered by their biological instability and rapid elimination following i.v. administration. Efforts to circumvent rapid plasma elimination have, to date, focused on decreasing cationic lipid content and incorporating polyethylene glycol (PEG)-modified lipids. In this study we wanted to determine whether highly charged cationic liposomes with surface-associated PEG could be designed to exhibit extended circulation lifetimes, while retaining tumor vascular targeting properties in an HT29 colorectal cancer xenograft model. Cationic liposomes prepared of DSPC, cationic lipids (DODAC, DOTAP, or DC-CHOL), and DSPE-PEG(2000) were studied. Our results demonstrate that formulations prepared with 50 mol% DODAC or DC-CHOL, and 20 mol% DSPE-PEG(2000) exhibited circulation half-lives ranging from 6.5 to 12.5 h. Biodistribution studies demonstrated that DC-CHOL formulations prepared with DSPE-PEG(2000) accumulated threefold higher in s.c. HT29 tumors than its PEG-free counterpart. Fluorescence microscopy studies suggested that the presence of DSPE-PEG(2000) did not adversely affect liposomal tumor vasculature targeting. We show for the first time that it is achievable to design highly charged, highly pegylated (20 mol% DSPE-PEG(2000)) cationic liposomes which exhibit both extended circulation lifetimes and tumor vascular targeting properties. (c) 2010 Wiley-Liss, Inc. and the American Pharmacists Association

Increased liver uptake of liposomes and improved targeting efficacy by labeling with asialofetuin in rodents.

PubMed

Wu, J; Liu, P; Zhu, J L; Maddukuri, S; Zern, M A

1998-03-01

To improve liposome-directed therapy of liver disease and gene delivery, it would be beneficial to selectively target hepatocytes. For this purpose, conventional liposomes (CL) were labeled with asialofetuin (AF), an asialoglycoprotein. The biodistribution of AF-labeled liposomes (AF-L) in mice and their incorporation into rat hepatocytes, and their potential use in acute liver injury, were investigated. AF-L displayed a quicker plasma clearance than CL, and 25.4%, 2.7%, and 1.2% of the injected dose remained in the plasma versus 47.0%, 26.1%, and 9.5% of CL, respectively at 2, 4, and 20 hours after the injection. Total liver uptake of AF-L (73%+/-3.9%) was markedly higher (P < .005) than CL (16.5%+/-1.8%) 4 hours after the injection. Liposomal radioactivity (cpm/mg) was greatly enhanced in the liver (11-fold) during the first 4 hours after the administration of 14C-AF-L, and was much higher than in 14C-CL-injected mice (1.5-fold). In vitro incubation of isolated rat hepatocytes with 14C-AF-L or intravenous injection of 14C-AF-L in rats resulted in higher hepatocyte-bound radioactivity compared with 14C-CL (P < .01-.005). AF-L-associated 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) fluorescent signals were not only located in Kupffer cells, but also in hepatocytes, in which bile canaliculus networks were imaged. Intravenous administration of vitamin E (VE)-associated CL (VE-CL, 1 mg/mouse) significantly lowered alanine transaminase (ALT) levels in CCl4-treated mice (196+/-79 vs. 2,107+/-235 U/mL; P < .01). The ALT level in CCl4 + VE-AF-L group was decreased to 38+/-16 units/mL, which was significantly lower than the CC14 + VE-CL group (P < .05). In conclusion, labeling liposomes with AF led to a shortened liposome plasma half-life and greatly enhanced uptake of AF-L liposome by the liver. The enhanced uptake resulted from an increased incorporation of hepatocytes with AF-L liposomes. VE-associated AF liposomes further improved the

Multifunctional targeted liposomal drug delivery for efficient glioblastoma treatment

PubMed Central

Belhadj, Zakia; Zhan, Changyou; Ying, Man; Wei, Xiaoli; Xie, Cao; Yan, Zhiqiang; Lu, Weiyue

2017-01-01

Glioblastoma multiforme (GBM) has been considered to be the most malignant brain tumors. Due to the existence of various barriers including the blood–brain barrier (BBB) and blood–brain tumor barrier (BBTB) greatly hinder the accumulation and deep penetration of chemotherapeutics, the treatment of glioma remains to be the most challenging task in clinic. In order to circumvent these hurdles, we developed a multifunctional liposomal glioma-targeted drug delivery system (c(RGDyK)/pHA-LS) modified with cyclic RGD (c(RGDyK)) and p-hydroxybenzoic acid (pHA) in which c(RGDyK) could target integrin αvβ3 overexpressed on the BBTB and glioma cells and pHA could target dopamine receptors on the BBB. In vitro, c(RGDyK)/pHA-LS could target glioblastoma cells (U87), brain capillary endothelial cells (bEnd.3) and umbilical vein endothelial cells (HUVECs) through a comprehensive pathway. Besides, c(RGDyK)/pHA-LS could also increase the cytotoxicity of doxorubicin encapsulated in liposomes on glioblastoma cells, and was able to penetrate inside the glioma spheroids after traversing the in vitro BBB and BBTB. In vivo, we demonstrated the targeting ability of c(RGDyK)/pHA-LS to intracranial glioma. As expected, c(RGDyK)/pHA-LS/DOX showed a median survival time of 35 days, which was 2.31-, 1.76- and 1.5-fold higher than that of LS/DOX, c(RGDyK)-LS/DOX, and pHA-LS/DOX, respectively. The findings here suggested that the multifunctional glioma-targeted drug delivery system modified with both c(RGDyK) and pHA displayed strong antiglioma efficiency in vitro and in vivo, representing a promising platform for glioma therapy. PMID:28978003

Targeted Therapy for Acute Autoimmune Myocarditis with Nano-Sized Liposomal FK506 in Rats.

PubMed

Okuda, Keiji; Fu, Hai Ying; Matsuzaki, Takashi; Araki, Ryo; Tsuchida, Shota; Thanikachalam, Punniyakoti V; Fukuta, Tatsuya; Asai, Tomohiro; Yamato, Masaki; Sanada, Shoji; Asanuma, Hiroshi; Asano, Yoshihiro; Asakura, Masanori; Hanawa, Haruo; Hao, Hiroyuki; Oku, Naoto; Takashima, Seiji; Kitakaze, Masafumi; Sakata, Yasushi; Minamino, Tetsuo

2016-01-01

Immunosuppressive agents are used for the treatment of immune-mediated myocarditis; however, the need to develop a more effective therapeutic approach remains. Nano-sized liposomes may accumulate in and selectively deliver drugs to an inflammatory lesion with enhanced vascular permeability. The aims of this study were to investigate the distribution of liposomal FK506, an immunosuppressive drug encapsulated within liposomes, and the drug's effects on cardiac function in a rat experimental autoimmune myocarditis (EAM) model. We prepared polyethylene glycol-modified liposomal FK506 (mean diameter: 109.5 ± 4.4 nm). We induced EAM by immunization with porcine myosin and assessed the tissue distribution of the nano-sized beads and liposomal FK506 in this model. After liposomal or free FK506 was administered on days 14 and 17 after immunization, the cytokine expression in the rat hearts along with the histological findings and hemodynamic parameters were determined on day 21. Ex vivo fluorescent imaging revealed that intravenously administered fluorescent-labeled nano-sized beads had accumulated in myocarditic but not normal hearts on day 14 after immunization and thereafter. Compared to the administration of free FK506, FK506 levels were increased in both the plasma and hearts of EAM rats when liposomal FK506 was administered. The administration of liposomal FK506 markedly suppressed the expression of cytokines, such as interferon-γ and tumor necrosis factor-α, and reduced inflammation and fibrosis in the myocardium on day 21 compared to free FK506. The administration of liposomal FK506 also markedly ameliorated cardiac dysfunction on day 21 compared to free FK506. Nano-sized liposomes may be a promising drug delivery system for targeting myocarditic hearts with cardioprotective agents.

Highly specific targeting of the TMPRSS2/ERG fusion gene using liposomal nanovectors

PubMed Central

Shao, Longjiang; Tekedereli, Ibrahim; Wang, Jianghua; Yuca, Erkan; Tsang, Susan; Sood, Anil; Lopez-Berestein, Gabriel; Ozpolat, Bulent; Ittmann, Michael

2012-01-01

Purpose The TMPRSS2/ERG (T/E) fusion gene is present in half of all prostate cancer (PCa) tumors. Fusion of the oncogenic ERG gene with the androgen-regulated TMPRSS2 gene promoter results in expression of fusion mRNAs in PCa cells. The junction of theTMPRSS2 and ERG derived portions of the fusion mRNA constitutes a cancer specific target in cells containing the T/E fusion gene. Targeting the most common alternatively spliced fusion gene mRNA junctional isoforms in vivo using siRNAs in liposomal nanovectors may potentially be a novel, low toxicity treatment for PCa. Experimental Design We designed and optimized siRNAs targeting the two most common T/E fusion gene mRNA junctional isoforms (Type III or Type VI). Specificity of siRNAs was assessed by transient co-transfection in vitro. To test their ability to inhibit growth of PCa cells expressing these fusion gene isoforms in vivo, specific siRNAs in liposomal nanovectors were used to treat mice bearing orthotopic or subcutaneous xenograft tumors expressing the targeted fusion isoforms. Results The targeting siRNAs were both potent and highly specific in vitro. In vivo they significantly inhibited tumor growth. The degree of growth inhibition was variable and was correlated with the extent of fusion gene knockdown. The growth inhibition was associated with marked inhibition of angiogenesis and, to a lesser degree, proliferation and a marked increase in apoptosis of tumor cells. No toxicity was observed. Conclusions Targeting the T/E fusion junction in vivo with specific siRNAs delivered via liposomal nanovectors is a promising therapy for men with PCa. PMID:23052253

Highly specific targeting of the TMPRSS2/ERG fusion gene using liposomal nanovectors.

PubMed

Shao, Longjiang; Tekedereli, Ibrahim; Wang, Jianghua; Yuca, Erkan; Tsang, Susan; Sood, Anil; Lopez-Berestein, Gabriel; Ozpolat, Bulent; Ittmann, Michael

2012-12-15

The TMPRSS2/ERG (T/E) fusion gene is present in half of all prostate cancer tumors. Fusion of the oncogenic ERG gene with the androgen-regulated TMPRSS2 gene promoter results in expression of fusion mRNAs in prostate cancer cells. The junction of theTMPRSS2- and ERG-derived portions of the fusion mRNA constitutes a cancer-specific target in cells containing the T/E fusion gene. Targeting the most common alternatively spliced fusion gene mRNA junctional isoforms in vivo using siRNAs in liposomal nanovectors may potentially be a novel, low-toxicity treatment for prostate cancer. We designed and optimized siRNAs targeting the two most common T/E fusion gene mRNA junctional isoforms (type III or type VI). Specificity of siRNAs was assessed by transient co-transfection in vitro. To test their ability to inhibit growth of prostate cancer cells expressing these fusion gene isoforms in vivo, specific siRNAs in liposomal nanovectors were used to treat mice bearing orthotopic or subcutaneous xenograft tumors expressing the targeted fusion isoforms. The targeting siRNAs were both potent and highly specific in vitro. In vivo they significantly inhibited tumor growth. The degree of growth inhibition was variable and was correlated with the extent of fusion gene knockdown. The growth inhibition was associated with marked inhibition of angiogenesis and, to a lesser degree, proliferation and a marked increase in apoptosis of tumor cells. No toxicity was observed. Targeting the T/E fusion junction in vivo with specific siRNAs delivered via liposomal nanovectors is a promising therapy for men with prostate cancer. ©2012 AACR.

Nuclear and Fluorescent Labeled PD-1-Liposome-DOX-64Cu/IRDye800CW Allows Improved Breast Tumor Targeted Imaging and Therapy.

PubMed

Du, Yang; Liang, Xiaolong; Li, Yuan; Sun, Ting; Jin, Zhengyu; Xue, Huadan; Tian, Jie

2017-11-06

The overexpression of programmed cell death-1 (PD-1) in tumors as breast cancer makes it a possible target for cancer imaging and therapy. Advances in molecular imaging, including radionuclide imaging and near-infrared fluorescence (NIRF) imaging, enable the detection of tumors with high sensitivity. In this study, we aim to develop a novel PD-1 antibody targeted positron emission tomography (PET) and NIRF labeled liposome loaded with doxorubicin (DOX) and evaluate its application for in vivo cancer imaging and therapy. IRDye800CW and 64 Cu were conjugated to liposomes with PD-1 antibody labeling, and DOX was inside the liposomes to form theranostic nanoparticles. The 4T1 tumors were successfully visualized with PD-1-Liposome-DOX- 64 Cu/IRDye800CW using NIRF/PET imaging. The bioluminescent imaging (BLI) results showed that tumor growth was significantly inhibited in the PD-1-Liposome-DOX-treated group than the IgG control. Our results highlight the potential of using dual-labeled theranostic PD-1 mAb-targeted Liposome-DOX- 64 Cu/IRDye800CW for the management of breast tumor.

Inhibition of hexokinase-2 with targeted liposomal 3-bromopyruvate in an ovarian tumor spheroid model of aerobic glycolysis

PubMed Central

Gandham, Srujan Kumar; Talekar, Meghna; Singh, Amit; Amiji, Mansoor M

2015-01-01

Background The objective of this study was to evaluate the expression levels of glycolytic markers, especially hexokinase-2 (HK2), using a three-dimensional multicellular spheroid model of human ovarian adenocarcinoma (SKOV-3) cells and to develop an epidermal growth factor receptor-targeted liposomal formulation for improving inhibition of HK2 and the cytotoxicity of 3-bromopyruvate (3-BPA). Methods Multicellular SKOV-3 tumor spheroids were developed using the hanging drop method and expression levels of glycolytic markers were examined. Non-targeted and epidermal growth factor receptor-targeted liposomal formulations of 3-BPA were formulated and characterized. Permeability and cellular uptake of the liposomal formulations in three-dimensional SKOV-3 spheroids was evaluated using confocal microscopy. The cytotoxicity and HK2 inhibition potential of solution form of 3-BPA was compared to the corresponding liposomal formulation by using cell proliferation and HK2 enzymatic assays. Results SKOV-3 spheroids were reproducibly developed using the 96-well hanging drop method, with an average size of 900 µm by day 5. HK2 enzyme activity levels under hypoxic conditions were found to be higher than under normoxic conditions (P<0.0001, Student’s t-test, unpaired and two-tailed). Liposomal formulations (both non-targeted and targeted) of 3-BPA showed a more potent inhibitory effect (P<0.001, Student’s t-test, unpaired and two-tailed) at a dose of 50 µM than the aqueous solution form at 3, 6, and 24 hours post administration. Similarly, the cytotoxic activity 3-BPA at various concentrations (10 µM–100 µM) showed that the liposomal formulations had an enhanced cytotoxic effect of 2–5-fold (P<0.0001, Student’s t-test, unpaired and two-tailed) when compared to the aqueous solution form for both 10 µM and 25 µM concentrations. Conclusion SKOV-3 spheroids developed by the hanging drop method can be used as a tumor aerobic glycolysis model for evaluation of therapies

Inhibition of hexokinase-2 with targeted liposomal 3-bromopyruvate in an ovarian tumor spheroid model of aerobic glycolysis.

PubMed

Gandham, Srujan Kumar; Talekar, Meghna; Singh, Amit; Amiji, Mansoor M

2015-01-01

The objective of this study was to evaluate the expression levels of glycolytic markers, especially hexokinase-2 (HK2), using a three-dimensional multicellular spheroid model of human ovarian adenocarcinoma (SKOV-3) cells and to develop an epidermal growth factor receptor-targeted liposomal formulation for improving inhibition of HK2 and the cytotoxicity of 3-bromopyruvate (3-BPA). Multicellular SKOV-3 tumor spheroids were developed using the hanging drop method and expression levels of glycolytic markers were examined. Non-targeted and epidermal growth factor receptor-targeted liposomal formulations of 3-BPA were formulated and characterized. Permeability and cellular uptake of the liposomal formulations in three-dimensional SKOV-3 spheroids was evaluated using confocal microscopy. The cytotoxicity and HK2 inhibition potential of solution form of 3-BPA was compared to the corresponding liposomal formulation by using cell proliferation and HK2 enzymatic assays. SKOV-3 spheroids were reproducibly developed using the 96-well hanging drop method, with an average size of 900 µm by day 5. HK2 enzyme activity levels under hypoxic conditions were found to be higher than under normoxic conditions (P<0.0001, Student's t-test, unpaired and two-tailed). Liposomal formulations (both non-targeted and targeted) of 3-BPA showed a more potent inhibitory effect (P<0.001, Student's t-test, unpaired and two-tailed) at a dose of 50 µM than the aqueous solution form at 3, 6, and 24 hours post administration. Similarly, the cytotoxic activity 3-BPA at various concentrations (10 µM-100 µM) showed that the liposomal formulations had an enhanced cytotoxic effect of 2-5-fold (P<0.0001, Student's t-test, unpaired and two-tailed) when compared to the aqueous solution form for both 10 µM and 25 µM concentrations. SKOV-3 spheroids developed by the hanging drop method can be used as a tumor aerobic glycolysis model for evaluation of therapies targeting the glycolytic pathway in cancer

Enzyme-Responsive Liposomes for the Delivery of Anticancer Drugs

PubMed Central

Fouladi, Farnaz; Steffen, Kristine J.; Mallik, Sanku

2017-01-01

Liposomes are nanocarriers that deliver the payloads at the target site, leading to therapeutic drug concentrations at the diseased site and reduced toxic effects in healthy tissues. Several approaches have been used to enhance the ability of the nanocarrier to target the specific tissues, including ligand-targeted liposomes and stimuli-responsive liposomes. Ligand-targeted liposomes exhibit higher uptake by the target tissue due to the targeting ligand attached to the surface, while, the stimuli-responsive liposomes do not release their cargo unless they expose to an endogenous or exogenous stimulant at the target site. In this review, we mainly focus on the liposomes that are responsive to pathologically increased levels of enzymes at the target site. Enzyme-responsive liposomes release their cargo upon contact with the enzyme through several destabilization mechanisms: a) structural perturbation in the lipid bilayer, b) removal of a shielding polymer from the surface and increased cellular uptake, c) cleavage of a lipopeptide or lipopolymer incorporated in the bilayer, and d) activation of a prodrug in the liposomes. PMID:28201868

Enzyme-Responsive Liposomes for the Delivery of Anticancer Drugs.

PubMed

Fouladi, Farnaz; Steffen, Kristine J; Mallik, Sanku

2017-04-19

Liposomes are nanocarriers that deliver the payloads at the target site, leading to therapeutic drug concentrations at the diseased site and reduced toxic effects in healthy tissues. Several approaches have been used to enhance the ability of the nanocarrier to target the specific tissues, including ligand-targeted liposomes and stimuli-responsive liposomes. Ligand-targeted liposomes exhibit higher uptake by the target tissue due to the targeting ligand attached to the surface, while the stimuli-responsive liposomes do not release their cargo unless they expose to an endogenous or exogenous stimulant at the target site. In this review, we mainly focus on the liposomes that are responsive to pathologically increased levels of enzymes at the target site. Enzyme-responsive liposomes release their cargo upon contact with the enzyme through several destabilization mechanisms: (1) structural perturbation in the lipid bilayer, (2) removal of a shielding polymer from the surface and increased cellular uptake, (3) cleavage of a lipopeptide or lipopolymer incorporated in the bilayer, and (4) activation of a prodrug in the liposomes.

Comparative study of (Asp)7-CHOL-modified liposome prepared using pre-insertion and post-insertion methods for bone targeting in vivo.

PubMed

Zhang, Lijing; Cao, Hua; Zhang, Jiaxin; Yang, Chengli; Hu, Tingting; Li, Huili; Yang, Wu; He, Gu; Song, Xiangrong; Tong, Aiping; Guo, Gang; Li, Rui; Jiang, Yu; Liu, Jiyan; Cai, Lulu; Zheng, Yu

2017-02-01

Specific delivery of drugs to bone tissue is very challenging due to the architecture and structure of bone tissue. A seven-repeat sequence of aspartate, a representative bone-targeting oligopeptide, is preferentially used for targeted therapy for bone diseases. In this study, Asp7-cholesterol((Asp)7-CHOL) was synthesized and (Asp)7-CHOL-modified liposome loaded with doxorubicin (DOX) was successfully prepared using both pre-insertion (pre-L) and post-insertion (post-L) methods. The formulation was optimized according to particle size, zeta potential and the drug-loading efficiency of the liposome. In addition, the bone affinity of the (Asp)7-CHOL-modified liposome was evaluated using a hydroxyapatite (HA) absorption method. The results suggested that (Asp)7-CHOL-modified liposome show excellent HA absorption; pre-L showed slightly higher HA binding than post-L. However, post-L had a higher DOX entrapment efficiency than pre-L. In vivo imaging further demonstrated that pre-L showed a higher bone-targeting efficiency than post-L, which was consistent with in vitro results. In all, (Asp)7-CHOL-modified liposome showed excellent bone-targeting activity, suggesting their potential for use as a drug delivery system for bone disease-targeted therapies.

GE11-modified liposomes for non-small cell lung cancer targeting: preparation, ex vitro and in vivo evaluation.

PubMed

Cheng, Liang; Huang, Fa-Zhen; Cheng, Li-Fang; Zhu, Ya-Qin; Hu, Qing; Li, Ling; Wei, Lin; Chen, Da-Wei

2014-01-01

Non-small cell lung cancer (NSCLC) is a serious threat to human health, and 40%-80% of NSCLCs express high levels of epidermal growth factor receptor (EGFR). GE11 is a novel peptide and exhibits high affinity for EGFR binding. The aim of this study was to construct and evaluate GE11-modified liposomes for targeted drug delivery to EGFR-positive NSCLC. Doxorubicin, a broad-spectrum antitumor agent, was chosen as the payload. GE11 was conjugated to the distal end of DSPE-PEG2000-Mal by an addition reaction with a conjugation efficiency above 90%. Doxorubicin-loaded liposomes containing GE11 (GE11-LP/DOX) at densities ranging from 0% to 15% were prepared by combination of a thin film hydration method and a post insertion method. Irrespective of GE11 density, the physicochemical properties of these targeted liposomes, including particle size, zeta potential, and drug entrapment efficiency, were nearly identical. Interestingly, the cytotoxic effect of the liposomes on A549 tumor cells was closely related to GE11 density, and liposomes with 10% GE11 had the highest tumor cell killing activity and a 2.6-fold lower half maximal inhibitory concentration than that of the nontargeted counterpart (PEG-LP/DOX). Fluorescence microscopy and flow cytometry analysis revealed that GE11 significantly increased cellular uptake of the liposomes, which could be ascribed to specific EGFR-mediated endocytosis. It was found that multiple endocytic pathways were involved in entry of GE11-LP/DOX into cells, but GE11 assisted in cellular internalization mainly via the clathrin-mediated endocytosis pathway. Importantly, the GE11-modified liposomes showed enhanced accumulation and prolonged retention in tumor tissue, as evidenced by a 2.2-fold stronger mean fluorescence intensity in tumor tissue than the unmodified liposomes at 24 hours. In summary, GE11-modified liposomes may be a promising platform for targeted delivery of chemotherapeutic drugs in NSCLC.

Evaluation of antitumor activity and cardiac toxicity of a bone-targeted ph-sensitive liposomal formulation in a bone metastasis tumor model in mice.

PubMed

Dos Santos Ferreira, Diego; Jesus de Oliveira Pinto, Bruno Luís; Kumar, Vidhya; Cardoso, Valbert Nascimento; Fernandes, Simone Odília; Souza, Cristina Maria; Cassali, Geovanni Dantas; Moore, Anna; Sosnovik, David E; Farrar, Christian T; Leite, Elaine Amaral; Alves, Ricardo José; de Oliveira, Mônica Cristina; Guimarães, Alexander Ramos; Caravan, Peter

2017-07-01

Chemotherapy for bone tumors is a major challenge because of the inability of therapeutics to penetrate dense bone mineral. We hypothesize that a nanostructured formulation with high affinity for bone could deliver drug to the tumor while minimizing off-target toxicity. Here, we evaluated the efficacy and toxicity of a novel bone-targeted, pH-sensitive liposomal formulation containing doxorubicin in an animal model of bone metastasis. Biodistribution studies with the liposome showed good uptake in tumor, but low accumulation of doxorubicin in the heart. Mice treated with the bone-targeted liposome formulation showed a 70% reduction in tumor volume, compared to 35% reduction for free doxorubicin at the same dose. Both cardiac toxicity and overall mortality were significantly lower for animals treated with the bone-targeted liposomes compared to free drug. Bone-targeted, pH-sensitive, doxorubicin containing liposomes represent a promising approach to selectively delivering doxorubicin to bone tumors while minimizing cardiac toxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

Renal-targeted delivery of triptolide by entrapment in pegylated TRX-20-modified liposomes

PubMed Central

Yuan, Zhi-xiang; Jia, Lu; Lim, Lee Yong; Lin, Ju-chun; Shu, Gang; Zhao, Ling; Ye, Gang; Liang, Xiao-xia; Ji, Hongming; Fu, Hua-lin

2017-01-01

Previously, 3,5-dipentadecyloxybenzamidine hydrochloride (TRX-20)-modified liposomes were reported to specifically target mesangial cells (MCs) in glomeruli. To further gain a better understanding of the characteristics and potential application for glomerular diseases of TRX-20-modified liposomes, we synthesized TRX-20 and prepared TRX-20-modified liposomes (TRX-LPs) with different molar ratios – 6% (6%-TRX-LP), 11% (11%-TRX-LP), and 14% (14%-TRX-LP) – of TRX-20 to total lipid in the present study. All TRX-LPs exhibited concentration-dependent toxicity against the MCs at a lipid concentration ranging from 0.01 to 1.0 mg/mL with IC50 values of 3.45, 1.13, and 0.55 mg/mL, respectively. Comparison of the cell viability of TRX-LPs indicated that high levels of TRX-20 caused severe cell mortality, with 11%-TRX-LP showing the higher cytoplasmic accumulation in the MCs. Triptolide (TP) as a model drug was first loaded into 11%-TRX-LP and the liposomes were further modified with PEG5000 (PEG-TRX-TP-LP) in an attempt to prolong their circulation in blood and enhance TP-mediated immune suppression. Due to specific binding to MCs, PEG-TRX-TP-LP undoubtedly showed better anti-inflammatory action in vitro, evidenced by the inhibition of release of nitric oxide (NO) and tumor necrosis factor-α from lipopolysaccharide-stimulated MCs, compared with free TP at the same dose. In vivo, the PEG-TRX-TP-LP effectively attenuated the symptoms of membranous nephropathic (MN) rats and improved biochemical markers including proteinuria, serum cholesterol, and albumin. Therefore, it can be concluded that the TRX-modified liposome is an effective platform to target the delivery of TP to glomeruli for the treatment of MN. PMID:28848346

Renal-targeted delivery of triptolide by entrapment in pegylated TRX-20-modified liposomes.

PubMed

Yuan, Zhi-Xiang; Jia, Lu; Lim, Lee Yong; Lin, Ju-Chun; Shu, Gang; Zhao, Ling; Ye, Gang; Liang, Xiao-Xia; Ji, Hongming; Fu, Hua-Lin

2017-01-01

Previously, 3,5-dipentadecyloxybenzamidine hydrochloride (TRX-20)-modified liposomes were reported to specifically target mesangial cells (MCs) in glomeruli. To further gain a better understanding of the characteristics and potential application for glomerular diseases of TRX-20-modified liposomes, we synthesized TRX-20 and prepared TRX-20-modified liposomes (TRX-LPs) with different molar ratios - 6% (6%-TRX-LP), 11% (11%-TRX-LP), and 14% (14%-TRX-LP) - of TRX-20 to total lipid in the present study. All TRX-LPs exhibited concentration-dependent toxicity against the MCs at a lipid concentration ranging from 0.01 to 1.0 mg/mL with IC 50 values of 3.45, 1.13, and 0.55 mg/mL, respectively. Comparison of the cell viability of TRX-LPs indicated that high levels of TRX-20 caused severe cell mortality, with 11%-TRX-LP showing the higher cytoplasmic accumulation in the MCs. Triptolide (TP) as a model drug was first loaded into 11%-TRX-LP and the liposomes were further modified with PEG 5000 (PEG-TRX-TP-LP) in an attempt to prolong their circulation in blood and enhance TP-mediated immune suppression. Due to specific binding to MCs, PEG-TRX-TP-LP undoubtedly showed better anti-inflammatory action in vitro, evidenced by the inhibition of release of nitric oxide (NO) and tumor necrosis factor-α from lipopolysaccharide-stimulated MCs, compared with free TP at the same dose. In vivo, the PEG-TRX-TP-LP effectively attenuated the symptoms of membranous nephropathic (MN) rats and improved biochemical markers including proteinuria, serum cholesterol, and albumin. Therefore, it can be concluded that the TRX-modified liposome is an effective platform to target the delivery of TP to glomeruli for the treatment of MN.

E-selectin liposomal and nanotube-targeted delivery of doxorubicin to circulating tumor cells

PubMed Central

Mitchell, Michael J.; Chen, Christina S.; Ponmudi, Varun; Hughes, Andrew D.; King, Michael R.

2012-01-01

The presence of circulating tumor cells (CTCs) is believed to lead to the formation of secondary tumors via an adhesion cascade involving interaction between adhesion receptors of endothelial cells and ligands on CTCs. Many CTCs express sialylated carbohydrate ligands on their surfaces that adhere to selectin protein found on inflamed endothelial cells. We have investigated the feasibility of using immobilized selectin proteins as a targeting mechanism for CTCs under flow. Herein, targeted liposomal doxorubicin (L-DXR) was functionalized with recombinant human E-selectin (ES) and polyethylene glycol (PEG) to target and kill cancer cells under shear flow, both when immobilized along a microtube device or sheared in a cone-and-plate viscometer in a dilute suspension. Healthy circulating cells such as red blood cells were not targeted by this mechanism and were left to freely circulate, and minimal leukocyte death was observed. Halloysite nanotube (HNT)-coated microtube devices immobilized with nanoscale liposomes significantly enhanced the targeting, capture, and killing of cancer cells. This work demonstrates that E-selectin functionalized L-DXR, sheared in suspension or immobilized onto microtube devices, provides a novel approach to selectively target and deliver chemotherapeutics to CTCs in the bloodstream. PMID:22421423

Characteristics of sequential targeting of brain glioma for transferrin-modified cisplatin liposome.

PubMed

Lv, Qing; Li, Li-Min; Han, Min; Tang, Xin-Jiang; Yao, Jin-Na; Ying, Xiao-Ying; Li, Fan-Zhu; Gao, Jian-Qing

2013-02-28

Methods on how to improve the sequential targeting of glioma subsequent to passing of drug through the blood-brain barrier (BBB) have been occasionally reported. However, the characteristics involved are poorly understood. In the present study, cisplatin (Cis) liposome (lipo) was modified with transferrin (Tf) to investigate the characteristics of potential sequential targeting to glioma. In bEnd3/C6 co-culture BBB models, higher transport efficiency across the BBB and cytotoxicity in basal C6 cells induced by Cis-lipo(Tf) than Cis-lipo and Cis-solution, suggest its sequential targeting effect. Interestingly, similar liposomal morphology as that of donor compartment was first demonstrated in the receptor solution of BBB models. Meanwhile, a greater acquisition in the lysosome of bEnd3, distributed sequentially into the nucleus of C6 cells were found for the Cis-lipo(Tf). Pre-incubation of chlorpromazine and Tf inhibited this process, indicating that a clathrin-dependent endocytosis is involved in the transport of Cis-lipo(Tf) across the BBB. Copyright © 2013 Elsevier B.V. All rights reserved.

Liposomes and nanotechnology in drug development: focus on ocular targets

PubMed Central

Honda, Miki; Asai, Tomohiro; Oku, Naoto; Araki, Yoshihiko; Tanaka, Minoru; Ebihara, Nobuyuki

2013-01-01

Poor drug delivery to lesions in patients’ eyes is a major obstacle to the treatment of ocular diseases. The accessibility of these areas to drugs is highly restricted by the presence of barriers, including the corneal barrier, aqueous barrier, and the inner and outer blood–retinal barriers. In particular, the posterior segment is difficult to reach for drugs because of its structural peculiarities. This review discusses various barriers to drug delivery and provides comprehensive information for designing nanoparticle-mediated drug delivery systems for the treatment of ocular diseases. Nanoparticles can be designed to improve penetration, controlled release, and drug targeting. As highlighted in this review, the therapeutic efficacy of drugs in ocular diseases has been reported to be enhanced by the use of nanoparticles such as liposomes, micro/nanospheres, microemulsions, and dendrimers. Our recent data show that intravitreal injection of targeted liposomes encapsulating an angiogenesis inhibitor caused significantly greater suppression of choroidal neovascularization than did the injection of free drug. Recent progress in ocular drug delivery systems research has provided new insights into drug development, and the use of nanoparticles for drug delivery is thus a promising approach for advanced therapy of ocular diseases. PMID:23439842

A targeted liposome delivery system for combretastatin A4: formulation optimization through drug loading and in vitro release studies.

PubMed

Nallamothu, Ramakrishna; Wood, George C; Kiani, Mohammad F; Moore, Bob M; Horton, Frank P; Thoma, Laura A

2006-01-01

Efficient liposomal therapeutics require high drug loading and low leakage. The objective of this study is to develop a targeted liposome delivery system for combretastatin A4 (CA4), a novel antivascular agent, with high loading and stable drug encapsulation. Liposomes composed of hydrogenated soybean phosphatidylcholine (HSPC), cholesterol, and distearoyl phosphoethanolamine-PEG-2000 conjugate (DSPE-PEG) were prepared by the lipid film hydration and extrusion process. Cyclic arginine-glycine-aspartic acid (RGD) peptides with affinity for alphav beta3-integrins overexpressed on tumor vascular endothelial cells were coupled to the distal end of polyethylene glycol (PEG) on the liposomes sterically stabilized with PEG (non-targeted liposomes; LCLs). Effect of lipid concentration, drug-to-lipid ratio, cholesterol, and DSPE-PEG content in the formulation on CA4 loading and its release from the liposomes was studied. Total liposomal CA4 levels obtained increased with increasing lipid concentration in the formulation. As the drug-to-lipid ratio increased from 10:100 to 20:100, total drug in the liposome formulation increased from 1.05+/-0.11 mg/mL to 1.55+/-0.13 mg/mL, respectively. When the drug-to-lipid ratio was further raised to 40:100, the total drug in liposome formulation did not increase, but the amount of free drug increased significantly, thereby decreasing the percent of entrapped drug. Increasing cholesterol content in the formulation decreased drug loading. In vitro drug leakage from the liposomes increased with increase in drug-to-lipid ratio or DSPE-PEG content in the formulation; whereas increasing cholesterol content of the formulation up to 30 mol-percent, decreased CA4 leakage from the liposomes. Ligand coupling to the liposome surface increased drug leakage as a function of ligand density. Optimized liposome formulation with 100 mM lipid concentration, 20:100 drug-to-lipid ratio, 30 mol-percent cholesterol, 4 mol-percent DSPE-PEG, and 1 mol

ICAM-1-Targeted Liposomes Loaded with Liver X Receptor Agonists Suppress PDGF-Induced Proliferation of Vascular Smooth Muscle Cells

NASA Astrophysics Data System (ADS)

Huang, Xu; Xu, Meng-Qi; Zhang, Wei; Ma, Sai; Guo, Weisheng; Wang, Yabin; Zhang, Yan; Gou, Tiantian; Chen, Yundai; Liang, Xing-Jie; Cao, Feng

2017-05-01

The proliferation of vascular smooth muscle cells (VSMCs) is one of the key events during the progress of atherosclerosis. The activated liver X receptor (LXR) signalling pathway is demonstrated to inhibit platelet-derived growth factor BB (PDGF-BB)-induced VSMC proliferation. Notably, following PDGF-BB stimulation, the expression of intercellular adhesion molecule-1 (ICAM-1) by VSMCs increases significantly. In this study, anti-ICAM-1 antibody-conjugated liposomes were fabricated for targeted delivery of a water-insoluble LXR agonist (T0901317) to inhibit VSMC proliferation. The liposomes were prepared by filming-rehydration method with uniform size distribution and considerable drug entrapment efficiency. The targeting effect of the anti-ICAM-T0901317 liposomes was evaluated by confocal laser scanning microscope (CLSM) and flow cytometry. Anti-ICAM-T0901317 liposomes showed significantly higher inhibition effect of VSMC proliferation than free T0901317 by CCk8 proliferation assays and BrdU staining. Western blot assay further confirmed that anti-ICAM-T0901317 liposomes inhibited retinoblastoma (Rb) phosphorylation and MCM6 expression. In conclusion, this study identified anti-ICAM-T0901317 liposomes as a promising nanotherapeutic approach to overcome VSMC proliferation during atherosclerosis progression.

A nanostructure of functional targeting epirubicin liposomes dually modified with aminophenyl glucose and cyclic pentapeptide used for brain glioblastoma treatment

PubMed Central

Zhang, Cheng-Xiang; Zhao, Wei-Yu; Liu, Lei; Ju, Rui-Jun; Mu, Li-Min; Zhao, Yao; Zeng, Fan; Xie, Hong-Jun; Yan, Yan; Lu, Wan-Liang

2015-01-01

The objectives of the present study were to develop functional targeting epirubicin liposomes for transferring drugs across the blood-brain barrier (BBB), treating glioblastoma, and disabling neovascularization. The studies were performed on glioblastoma cells in vitro and on glioblastoma-bearing mice. The results showed that the constructed liposomes had a high encapsulation efficiency for drugs (>95%), suitable particle size (109 nm), and less leakage in the blood component-containing system; were significantly able to be transported across the BBB; and exhibited efficacies in killing glioblastoma cells and in destroying glioblastoma neovasculature in vitro and in glioblastoma-bearing mice. The action mechanisms of functional targeting epirubicin liposomes correlated with the following features: the long circulation in the blood system, the ability to be transported across the BBB via glucose transporter-1, and the targeting effects on glioblastoma cells and on the endothelial cells of the glioblastoma neovasculature via the integrin β3 receptor. In conclusion, functional targeting epirubicin liposomes could be used as a potential therapy for treating brain glioblastoma and disabling neovascularization in brain glioblastomas. PMID:26418720

Development of a liposomal delivery system for temperature-triggered release of a tumor targeting agent, Ln(III)-DOTA-phenylboronate.

PubMed

Djanashvili, Kristina; ten Hagen, Timo L M; Blangé, Roy; Schipper, Debby; Peters, Joop A; Koning, Gerben A

2011-02-01

Liposomes, capable of temperature-triggered content release at the site of interest, can be of great importance for imaging and therapy of tumors. The delivery of imaging agents or therapeutics can be improved by application of liposomes with a gel-to-liquid phase-transition temperature suitable for mild hyperthermia (41-43°C), and by prolonging their circulation time by incorporation of lipids containing polyethyleneglycol moieties. Still, the rapid wash out of the delivered material from the tumor tissue is a major obstacle for both imaging and therapy. In this study, we developed an optimized temperature sensitive liposomal system to be used with mild hyperthermia: highly stable at physiological temperature and with a sharp transition of the bilayer at 41.5°C, with subsequent rapid release of entrapped compounds such as calcein or tumor cell-targeting contrast agents. Intravital microscopy on calcein/rhodamine containing liposomes was applied to demonstrate the applicability of this system in vivo. The calcein loaded liposomes were injected iv into nude mice with a human BLM melanoma tumor implanted in a dorsal skin-fold window chamber. Arrival of the liposomes at the tumor site and content release after temperature increase were monitored. The results demonstrated not only accumulation of the liposomes at the tumor site, but also a massive release of calcein after increase of the temperature to 41°C. The versatility of the thermosensitive liposomes was further demonstrated by encapsulation of a tumor cell-targeting DOTA-phenylboronate conjugate and its release at elevated temperatures. The DOTA ligand in this system is able to chelate a variety of metals suitable for both diagnostic and therapeutic applications, whereas the phenylboronate function is able to target specifically to tumor cells through a covalent binding with sialic acid moieties over-expressed on their surface upon heat-triggered release from the liposomal carrier. Copyright © 2010 Elsevier

In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging.

PubMed

Gu, Meng-Jie; Li, Kun-Feng; Zhang, Lan-Xin; Wang, Huan; Liu, Li-Si; Zheng, Zhuo-Zhao; Han, Nan-Yin; Yang, Zhen-Jun; Fan, Tian-Yuan

2015-01-01

Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI) diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III) [N,N-bis-stearylamidomethyl-N'-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs). Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA), gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor.

In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging

PubMed Central

Gu, Meng-Jie; Li, Kun-Feng; Zhang, Lan-Xin; Wang, Huan; Liu, Li-Si; Zheng, Zhuo-Zhao; Han, Nan-Yin; Yang, Zhen-Jun; Fan, Tian-Yuan

2015-01-01

Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI) diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III) [N,N-bis-stearylamidomethyl-N′-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs). Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA), gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor. PMID:26316749

Receptor-targeted liposome-peptide-siRNA nanoparticles represent an efficient delivery system for MRTF silencing in conjunctival fibrosis

NASA Astrophysics Data System (ADS)

Yu-Wai-Man, Cynthia; Tagalakis, Aristides D.; Manunta, Maria D.; Hart, Stephen L.; Khaw, Peng T.

2016-02-01

There is increasing evidence that the Myocardin-related transcription factor/Serum response factor (MRTF/SRF) pathway plays a key role in fibroblast activation and that knocking down MRTF can lead to reduced scarring and fibrosis. Here, we have developed a receptor-targeted liposome-peptide-siRNA nanoparticle as a non-viral delivery system for MRTF-B siRNA in conjunctival fibrosis. Using 50 nM siRNA, the MRTF-B gene was efficiently silenced by 76% and 72% with LYR and LER nanoparticles, respectively. The silencing efficiency was low when non-targeting peptides or siRNA alone or liposome-siRNA alone were used. LYR and LER nanoparticles also showed higher silencing efficiency than PEGylated LYR-P and LER-P nanoparticles. The nanoparticles were not cytotoxic using different liposomes, targeting peptides, and 50 nM siRNA. Three-dimensional fibroblast-populated collagen matrices were also used as a functional assay to measure contraction in vitro, and showed that MRTF-B LYR nanoparticles completely blocked matrix contraction after a single transfection treatment. In conclusion, this is the first study to develop and show that receptor-targeted liposome-peptide-siRNA nanoparticles represent an efficient and safe non-viral siRNA delivery system that could be used to prevent fibrosis after glaucoma filtration surgery and other contractile scarring conditions in the eye.

Targeting of small molecule anticancer drugs to the tumour and its vasculature using cationic liposomes: lessons from gene therapy

PubMed Central

Dass, Crispin R; Choong, Peter FM

2006-01-01

Cationic (positively charged) liposomes have been tested in various gene therapy clinical trials for neoplastic and other diseases. They have demonstrated selectivity for tumour vascular endothelial cells raising hopes for both antiangiogenic and antivascular therapies. They are also capable of being selectively delivered to the lungs and liver when administered intravenously. These vesicles are being targeted to the tumour in various parts of the body by using advanced liposomal systems such as ligand-receptor and antibody-antigen combinations. At present, the transferrin receptor is commonly used for cancer-targeted drug delivery systems including cationic liposomes. This review looks at the growing utility of these vesicles for delivery of small molecule anticancer drugs. PMID:16792817

Site-specific antibody-liposome conjugation through copper-free click chemistry: a molecular biology approach for targeted photodynamic therapy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Obaid, Girgis; Wang, Yucheng; Kuriakose, Jerrin; Broekgaarden, Mans; Alkhateeb, Ahmed; Bulin, Anne-Laure; Hui, James; Tsourkas, Andrew; Hasan, Tayyaba

2016-03-01

Nanocarriers, such as liposomes, have the ability to potentiate photodynamic therapy (PDT) treatment regimens by the encapsulation of high payloads of photosensitizers and enhance their passive delivery to tumors through the enhanced permeability and retention effect. By conjugating targeting moieties to the surface of the liposomal nanoconstructs, cellular selectivity is imparted on them and PDT-based therapies can be performed with significantly higher dose tolerances, as off-target toxicity is simultaneously reduced.1 However, the maximal benefits of conventional targeted nanocarriers, including liposomes, are hindered by practical limitations including chemical instability, non-selective conjugation chemistry, poor control over ligand orientation, and loss of ligand functionality following conjugation, amongst others.2 We have developed a robust, physically and chemically stable liposomal nanoplatform containing benzoporphyrin derivative photosensitizer molecules within the phospholipid bilayer and an optimized surface density of strained cyclooctyne moieties for `click' conjugation to azido-functionalized antibodies.3 The clinical chimeric anti-EGFR antibody Cetuximab is site-specifically photocrosslinked to a recombinant bioengineered that recognizes the antibody's Fc region, containing a terminal azide.4 The copper-free click conjugation of the bioengineered Cetuximab derivative to the optimized photosensitizing liposome provides exceptional control over the antibody's optimal orientation for cellular antigen binding. Importantly, the reaction occurs rapidly under physiological conditions, bioorthogonally (selectively in the presence of other biomolecules) and without the need for toxic copper catalysis.3 Such state-of-the-art conjugation strategies push the boundaries of targeted photodynamic therapy beyond the limitations of traditional chemical coupling techniques to produce more robust and effective targeted therapeutics with applications beyond

CD9 monoclonal antibody-conjugated PEGylated liposomes for targeted delivery of rapamycin in the treatment of cellular senescence

NASA Astrophysics Data System (ADS)

Thuy Nguyen, Hanh; Thapa, Raj Kumar; Shin, Beom Soo; Jeong, Jee-Heon; Kim, Jae-Ryong; Yong, Chul Soon; Kim, Jong Oh

2017-03-01

Premature cellular senescence refers to the state of irreversible cell cycle arrest due to DNA damage or other stresses. In this study, CD9 monoclonal antibody (CD9mAb) was successfully conjugated to the surface of PEGylated liposomes for targeted delivery of rapamycin (LR-CD9mAb) to overcome senescence of CD9 receptor-overexpressing cells. LR-CD9mAb has a small particle size (143.3 ± 2.4 nm), narrow size distribution (polydispersity index: 0.220 ± 0.036), and negative zeta potential (-14.6 ± 1.2 mV). The uptake of CD9-targeted liposomes by premature senescent human dermal fibroblasts (HDFs) was higher than that by young HDFs, as displayed by confocal microscopic images. The senescence might not be reversed by treatment with rapamycin; however, the drug promoted cell proliferation and reduced the number of cells that expressed the senescence-associated-β-galactosidase (SA-β-gal). These effects were further confirmed by cell viability, cell cycle, and Western blotting analyses. Moreover, CD9-targeted liposomes showed better anti-senescence activity, in comparison with free rapamycin or the conventional liposomal formulation, suggesting the potential application of this system in further in vivo studies.

The enhanced longevity and liver targetability of Paclitaxel by hybrid liposomes encapsulating Paclitaxel-conjugated gold nanoparticles.

PubMed

Bao, Quan-Ying; Zhang, Ning; Geng, Dong-Dong; Xue, Jing-Wei; Merritt, Mackenzie; Zhang, Can; Ding, Ya

2014-12-30

Organic and inorganic drug delivery systems both demonstrate their own advantages and challenges in practical applications. Combining these two drug delivery strategies in one system is expected to solve their current issues and achieve desirable functions. In this paper, gold nanoparticles (GNPs) and liposomes have been chosen as the model systems to construct a hybrid system and investigate its performance for the tumor therapy of Paclitaxel (PTX). The thiol-terminated polyethylene glycol (PEG400)-PTX derivative has been covalently modified on the surface of GNPs, followed by the encapsulation of PTX-conjugated GNPs (PTX-PEG400@GNPs) in liposomes. The hybrid liposomes solve the solubility and stability problems of gold conjugates and show high drug loading capacity. In vitro PTX release from the hybrid system maintains the similar sustained behavior demonstrated in its conjugates. Under the protection of a biocompatible liposome shell, encapsulated PTX shows enhanced circulation longevity and liver targetability compared to Taxol(®) and PTX-PEG400@GNPs suspension in the pharmacokinetic and biodistribution studies. These indicate that encapsulating drug-conjugated inorganic nanoparticles inside organic carriers maintains the superiority of both vehicles and improves the performance of hybrid systems. Although these attributes of hybrid liposomes lead to a better therapeutic capacity in a murine liver cancer model than that of the comparison groups, it shows no significant difference from Taxol(®) and conjugate suspension. This result could be due to the delayed and sustained drug release from the system. However, it indicates the promising potential for these hybrid liposomes will allow further construction of a compound preparation with improved performance that is based on their enhanced longevity and liver targetability of Paclitaxel. Copyright © 2014 Elsevier B.V. All rights reserved.

Study of the pH-sensitive mechanism of tumor-targeting liposomes.

PubMed

Fan, Yang; Chen, Cong; Huang, Yiheng; Zhang, Fang; Lin, Guimei

2017-03-01

Currently, the phosphatidylethanolamine-based, pH-sensitive, liposome drug-delivery system has been widely developed for efficient, targeted cancer therapy. However, the mechanism of pH sensitivity was unclear; it is a main obstacle in controlling the preparation of pH-sensitive liposomes (PSLs).Therefore, our research is aimed at clarifying the pH-response mechanism of the various molecules that compose liposomes. We chose the small pH-sensitive molecules oleic acid (OA), linoleic acid (LA) and cholesteryl hemisuccinate (CHEMS) and the fundamental lipids cholesterol and phosphatidylethanolamine (PE) as test molecules. The PSLs were prepared using the thin-film hydration method and characterized in detail at various pH values (pH 5.0, 6.0 and 7.4), including particle size, ζ-potential, drug encapsulation efficiency and drug loading. The surface structure was observed by transmission electron microscopy (TEM), and the electrical conductivity of the liposome dispersion was also tested. The calorimetric analysis was conducted by Nano-differential scanning calorimetry (Nano-DSC). The in vitro drug release profile showed that PSLs exhibit good pH sensitivity. At neutral pH, the particle size was approximately 150nm, and it dramatically increased at pH 5.0. The ζ-potential increased as the pH decreased. The Nano-DSC results showed that cholesterol and CHEMS can both increase the stability and phase transfer temperature of PSLs. Conductivity increased to a maximum at pH 5.0 and was rather low at pH 7.4. In conclusion, results show that the three kinds of liposomes have pH responsive release characteristics in acidic pH. The OA-PSLs have a pH sensitive point of 5. Since CHEMS has a cholesterol-like structure, it can stabilizes the phospholipid bilayer under neutral conditions as shown in the Nano-DSC data, and because it has a special steroidal rigid structure, it exhibits better pH response characteristics under acidic conditions. Copyright © 2016 Elsevier B.V. All

Dual Targeting Biomimetic Liposomes for Paclitaxel/DNA Combination Cancer Treatment

PubMed Central

Liu, Guo-Xia; Fang, Gui-Qing; Xu, Wei

2014-01-01

Combinations of chemotherapeutic drugs with nucleic acid has shown great promise in cancer therapy. In the present study, paclitaxel (PTX) and DNA were co-loaded in the hyaluronic acid (HA) and folate (FA)-modified liposomes (HA/FA/PPD), to obtain the dual targeting biomimetic nanovector. The prepared HA/FA/PPD exhibited nanosized structure and narrow size distributions (247.4 ± 4.2 nm) with appropriate negative charge of −25.40 ± 2.7 mV. HA/FA/PD (PTX free HA/FA/PPD) showed almost no toxicity on murine malignant melanoma cell line (B16) and human hepatocellular carcinoma cell line (HepG2) (higher than 80% cell viability), demonstrating the safety of the blank nanovector. In comparison with the FA-modified PTX/DNA co-loaded liposomes (FA/PPD), HA/FA/PPD showed significant superiority in protecting the nanoparticles from aggregation in the presence of plasma and degradation by DNase I. Moreover, HA/FA/PPD could also significantly improve the transfection efficiency and cellular internalization rates on B16 cells comparing to that of FA/PPD (p < 0.05) and PPD (p < 0.01), demonstrating the great advantages of dual targeting properties. Furthermore, fluorescence microscope and flow cytometry results showed that PTX and DNA could be effectively co-delivered into the same tumor cell via HA/FA/PPD, contributing to PTX/DNA combination cancer treatment. In conclusion, the obtained HA/FA/PPD in the study could effectively target tumor cells, enhance transfection efficiency and subsequently achieve the co-delivery of PTX and DNA, displaying great potential for optimal combination therapy. PMID:25177862

Electromagnetic field triggered drug and chemical delivery via liposomes

DOEpatents

Liburdy, R.P.

1993-03-02

The present invention relates to a system and to a method of delivering a drug to a preselected target body site of a patient, comprising the steps of encapsulating the chemical agent within liposomes, essentially temperature insensitive, i.e. not having a specific predetermined phase transition temperature within the specific temperature range of drug administration; administering the liposomes to the target body site; and subjecting the target body site to nonionizing electromagnetic fields in an area of the preselected target body in order to release the chemical agent from the liposomes at a temperature of between about +10 and 65 C. The invention further relates to the use of the liposomes to bind to the surface of or to enter target tissue or an organ in a living system, and, when subjected to a nonionizing field, to release a drug from the liposomes into the target site.

Electromagnetic field triggered drug and chemical delivery via liposomes

DOEpatents

Liburdy, Robert P.

1993-01-01

The present invention relates to a system and to a method of delivering a drug to a preselected target body site of a patient, comprising the steps of encapsulating the chemical agent within liposomes, essentially temperature insensitive, i.e. not having a specific predetermined phase transition temperature within the specific temperature range of drug administration; administering the liposomes to the target body site; and subjecting the target body site to nonionizing electromagnetic fields in an area of the preselected target body in order to release said chemical agent from the liposomes at a temperature of between about +10 and 65.degree. C. The invention further relates to the use of said liposomes to bind to the surface of or to enter target tissue or an organ in a living system, and, when subjected to a nonionizing field, to release a drug from the liposomes into the target site.

Multiple polysaccharide-drug complex-loaded liposomes: A unique strategy in drug loading and cancer targeting.

PubMed

Ruttala, Hima Bindu; Ramasamy, Thiruganesh; Gupta, Biki; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

2017-10-01

In the present study, a unique strategy was developed to develop nanocarriers containing multiple therapeutics with controlled release characteristics. In this study, we demonstrated the synthesis of dextran sulfate-doxorubicin (DS-DOX) and alginate-cisplatin (AL-CIS) polymer-drug complexes to produce a transferrin ligand-conjugated liposome. The targeted nanoparticles (TL-DDAC) were nano-sized and spherical. The targeted liposome exhibited a specific receptor-mediated endocytic uptake in cancer cells. The enhanced cellular uptake of TL-DDAC resulted in a significantly better anticancer effect in resistant and sensitive breast cancer cells compared to that of the free drugs. Specifically, DOX and CIS at a molar ratio of 1:1 exhibited better therapeutic performance compared to that of other combinations. The combination of an anthracycline-based topoisomerase II inhibitor (DOX) and a platinum compound (CIS) resulted in significantly higher cell apoptosis (early and late) in both types of cancer cells. In conclusion, treatment with DS-DOX and AL-CIS based combination liposomes modified with transferrin (TL-DDAC) was an effective cancer treatment strategy. Further investigation in clinically relevant animal models is warranted to prove the therapeutic efficacy of this unique strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electromagnetic field triggered drug and chemical delivery via liposomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liburdy, R.P.

1993-03-02

The present invention relates to a system and to a method of delivering a drug to a preselected target body site of a patient, comprising the steps of encapsulating the chemical agent within liposomes, essentially temperature insensitive, i.e. not having a specific predetermined phase transition temperature within the specific temperature range of drug administration; administering the liposomes to the target body site; and subjecting the target body site to nonionizing electromagnetic fields in an area of the preselected target body in order to release the chemical agent from the liposomes at a temperature of between about +10 and 65 C.more » The invention further relates to the use of the liposomes to bind to the surface of or to enter target tissue or an organ in a living system, and, when subjected to a nonionizing field, to release a drug from the liposomes into the target site.« less

Formulation, Development, and In Vitro Evaluation of a CD22 Targeted Liposomal System Containing a Non-Cardiotoxic Anthracycline for B Cell Malignancies.

PubMed

Mittal, Nivesh K; Mandal, Bivash; Balabathula, Pavan; Setua, Saini; Janagam, Dileep R; Lothstein, Leonard; Thoma, Laura A; Wood, George C

2018-04-15

Doxorubicin cardiotoxicity has led to the development of superior chemotherapeutic agents such as AD 198. However, depletion of healthy neutrophils and thrombocytes from AD 198 therapy must be limited. This can be done by the development of a targeted drug delivery system that delivers AD 198 to the malignant cells. The current research highlights the development and in vitro analysis of targeted liposomes containing AD 198. The best lipids were identified and optimized for physicochemical effects on the liposomal system. Physiochemical characteristics such as size, ζ-potential, and dissolution were also studied. Active targeting to CD22 positive cells was achieved by conjugating anti-CD22 Fab’ to the liposomal surface. Size and ζ-potential of the liposomes was between 115 and 145 nm, and −8 to−15 mV. 30% drug was released over 72 h. Higher cytotoxicity was observed in CD22+ve Daudi cells compared to CD22−ve Jurkat cells. The route of uptake was a clathrin- and caveolin-independent pathway. Intracellular localization of the liposomes was in the endolysosomes. Upon drug release, apoptotic pathways were activated partly by the regulation of apoptotic and oncoproteins such as caspase-3 and c-myc. It was observed that the CD22 targeted drug delivery system was more potent and specific compared to other untargeted formulations.

RGD-modified pH-sensitive liposomes for docetaxel tumor targeting.

PubMed

Chang, Minglu; Lu, Shanshan; Zhang, Fang; Zuo, Tiantian; Guan, Yuanyuan; Wei, Ting; Shao, Wei; Lin, Guimei

2015-05-01

Phosphatidylethanolamine-based pH-sensitive liposomes of various compositions have been described as efficient systems for delivery of therapeutic molecules into tumor cells. The aim of this work was to develop a drug delivery system based on pH-sensitive liposomes (PLPs) that were modified with arginine-glycine-aspartic acid (RGD) peptide to enhance the effectiveness of docetaxel treatment. Docetaxel/coumarin-6 loaded PLPs were prepared by the thin-film dispersion method and characterized in detail, including by particle size, polydispersity, zeta potential and drug encapsulation efficiency. In vitro studies using MCF-7, HepG2and A549 cells were employed to investigate cytotoxicity and cellular uptake of the drug solution or docetaxel/coumarin-6 loaded PLPs. The accumulation of 7-nitro-2-1,3-benzoxadiazol-4-yl (NBD)-labeled liposomes in vivo was studied through tumor section imaging of xenograft mouse models of MCF-7 24h after intravenous administration. The particle size of the non-coated or RGD modified PLPs ranged between 146 and 129nm. Drug release in vitro was modestly prolonged and had good pH sensitivity. In the in vitro study, RGD-coated PLPs showed higher cytotoxicity and cellular uptake relative to non-coated ones. The results of the in vivo study showed that RGD-coated PLPs had higher fluorescence, which suggested a more efficient accumulation than normal PLPs in tumors. In conclusion, these results confirmed RGD-modified PLPs as a potential drug delivery system to achieve controlled release and tumor targeting. Copyright © 2015 Elsevier B.V. All rights reserved.

Revisiting nanoparticle technology for blood-brain barrier transport: Unfolding at the endothelial gate improves the fate of transferrin receptor-targeted liposomes.

PubMed

Johnsen, Kasper Bendix; Moos, Torben

2016-01-28

An unmet need exists for therapeutic compounds to traverse the brain capillary endothelial cells that denote the blood-brain barrier (BBB) to deliver effective treatment to the diseased brain. The use of nanoparticle technology for targeted delivery to the brain implies that targeted liposomes encapsulating a drug of interest will undergo receptor-mediated uptake and transport through the BBB with a subsequent unfolding of the liposomal content inside the brain, hence revealing drug release to adjacent drug-demanding neurons. As transferrin receptors (TfRs) are present on brain capillary endothelial, but not on endothelial cells elsewhere in the body, the use of TfR-targeted liposomes - colloidal particulates with a phospholipid bilayer membrane - remains the most relevant strategy to obtain efficient drug delivery to the brain. However, many studies have failed to provide sufficient quantitative data to proof passage of the BBB and significant appearance of drugs inside the brain parenchyma. Here, we critically evaluate the current evidence on the use of TfR-targeted liposomes for brain drug delivery based on a thorough investigation of all available studies within this research field. We focus on issues with respect to experimental design and data analysis that may provide an explanation to conflicting reports, and we discuss possible explanations for the current lack of sufficient transcytosis across the BBB for implementation in the design of TfR-targeted liposomes. We finally provide a list of suggestions for strategies to obtain substantial uptake and transport of drug carriers at the BBB with a concomitant transport of therapeutics into the brain. Copyright © 2015 Elsevier B.V. All rights reserved.

Lipid raft-like liposomes used for targeted delivery of a chimeric entry-inhibitor peptide with anti-HIV-1 activity.

PubMed

Gómara, María José; Pérez-Pomeda, Ignacio; Gatell, José María; Sánchez-Merino, Victor; Yuste, Eloisa; Haro, Isabel

2017-02-01

The work reports the design and synthesis of a chimeric peptide that is composed of the peptide sequences of two entry inhibitors which target different sites of HIV-1 gp41. The chimeric peptide offers the advantage of targeting two gp41 regions simultaneously: the fusion peptide and the loop both of which are membrane active and participate in the membrane fusion process. We therefore use lipid raft-like liposomes as a tool to specifically direct the chimeric inhibitor peptide to the membrane domains where the HIV-1 envelope protein is located. Moreover, the liposomes that mimic the viral membrane composition protect the chimeric peptide against proteolytic digestion thereby increasing the stability of the peptide. The described liposome preparations are suitable nanosystems for managing hydrophobic entry-inhibitor peptides as putative therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

Targeting distinct myeloid cell populations in vivo using polymers, liposomes and microbubbles.

PubMed

Ergen, Can; Heymann, Felix; Al Rawashdeh, Wa'el; Gremse, Felix; Bartneck, Matthias; Panzer, Ulf; Pola, Robert; Pechar, Michal; Storm, Gert; Mohr, Nicole; Barz, Matthias; Zentel, Rudolf; Kiessling, Fabian; Trautwein, Christian; Lammers, Twan; Tacke, Frank

2017-01-01

Identifying intended or accidental cellular targets for drug delivery systems is highly relevant for evaluating therapeutic and toxic effects. However, limited knowledge exists on the distribution of nano- and micrometer-sized carrier systems at the cellular level in different organs. We hypothesized that clinically relevant carrier materials, differing in composition and size, are able to target distinct myeloid cell subsets that control inflammatory processes, such as macrophages, neutrophils, monocytes and dendritic cells. Therefore, we analyzed the biodistribution and in vivo cellular uptake of intravenously injected poly(N-(2-hydroxypropyl) methacrylamide) polymers, PEGylated liposomes and poly(butyl cyanoacrylate) microbubbles in mice, using whole-body imaging (computed tomography - fluorescence-mediated tomography), intra-organ imaging (intravital multi-photon microscopy) and cellular analysis (flow cytometry of blood, liver, spleen, lung and kidney). While the three carrier materials shared accumulation in tissue macrophages in liver and spleen, they notably differed in uptake by other myeloid subsets. Kupffer cells and splenic red pulp macrophages rapidly take up microbubbles. Liposomes efficiently reach dendritic cells in liver, lung and kidney. Polymers exhibit the longest circulation half-life and target endothelial cells in the liver, neutrophils and alveolar macrophages. The identification of such previously unrecognized target cell populations might open up new avenues for more efficient drug delivery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrasound effects on brain-targeting mannosylated liposomes: in vitro and blood-brain barrier transport investigations.

PubMed

Zidan, Ahmed S; Aldawsari, Hibah

2015-01-01

Delivering drugs to intracerebral regions can be accomplished by improving the capacity of transport through blood-brain barrier. Using sertraline as model drug for brain targeting, the current study aimed at modifying its liposomal vesicles with mannopyranoside. Box-Behnken design was employed to statistically optimize the ultrasound parameters, namely ultrasound amplitude, time, and temperature, for maximum mannosylation capacity, sertraline entrapment, and surface charge while minimizing vesicular size. Moreover, in vitro blood-brain barrier transport model was established to assess the transendothelial capacity of the optimized mannosylated vesicles. Results showed a dependence of vesicular size, mannosylation capacity, and sertraline entrapment on cavitation and bubble implosion events that were related to ultrasound power amplitude, temperature. However, short ultrasound duration was required to achieve >90% mannosylation with nanosized vesicles (<200 nm) of narrow size distribution. Optimized ultrasound parameters of 65°C, 27%, and 59 seconds for ultrasound temperature, amplitude, and time were elucidated to produce 81.1%, 46.6 nm, and 77.6% sertraline entrapment, vesicular size, and mannosylation capacity, respectively. Moreover, the transendothelial ability was significantly increased by 2.5-fold by mannosylation through binding with glucose transporters. Hence, mannosylated liposomes processed by ultrasound could be a promising approach for manufacturing and scale-up of brain-targeting liposomes.

Targeted delivery of transferrin-conjugated liposomes to an orthotopic model of lung cancer in nude rats.

PubMed

Gaspar, Maria Manuela; Radomska, Anna; Gobbo, Oliviero L; Bakowsky, Udo; Radomski, Marek W; Ehrhardt, Carsten

2012-12-01

Lung cancer is the leading cause of cancer death worldwide. Pulmonary anticancer therapy might offer several advantages over systemic delivery, leading to an increased exposure of the lung tumor to the drug, while minimizing side effects, due to regional containment. Here, we studied if a combination of inhalation therapy and drug targeting holds potential as an even more efficient lung cancer therapy. Transferrin (Tf )-conjugated PEG liposomes loaded with doxorubicin (DOX) were administered using an intracorporeal nebulizing catheter to an orthotopic lung cancer model established in athymic Rowett nude rats. Different DOX formulations and doses (0.2 and 0.4 mg/kg) were tested and the influence on tumor progression and life span of rats was evaluated in comparison with the i.v. administration of Tf-PEG-liposomes loaded with DOX at a therapeutic dose of 2 mg/kg. Rats in the untreated control group showed significant weight loss 2 weeks after tumor induction and died between days 19 and 29. Lungs of these animals showed multiple foci of neoplastic deposits, ranging up to 20 mm replacing the entire lobe. Empty Tf-liposomes showed a significant effect on survival time. This might be caused by the secondary cytotoxicity via stimulation of pulmonary macrophages. All animal treated intravenously also perished before the end of the study. No significant (p<0.05) improvement in survival was observed between the groups treated with aerosols of free drug, DOX encapsulated in plain and in Tf-modified liposomes. However, more animals survived in the Tf-liposome groups than in the other treatment regimes, and their lung tissue generally had fewer and smaller tumors. Nevertheless, the size of the groups, and the duration of the trial render it impossible to come to a definite conclusion. Drug targeting demonstrated potential for improving the aerosol treatment of lung cancer.

Lactoferrin-modified PEGylated liposomes loaded with doxorubicin for targeting delivery to hepatocellular carcinoma

PubMed Central

Wei, Minyan; Guo, Xiucai; Tu, Liuxiao; Zou, Qi; Li, Qi; Tang, Chenyi; Chen, Bao; Xu, Yuehong; Wu, Chuanbin

2015-01-01

Lactoferrin (Lf) is a potential-targeting ligand for hepatocellular carcinoma (HCC) cells because of its specific binding with asialoglycoprotein receptor (ASGPR). In this present work, a doxorubicin (DOX)-loaded, Lf-modified, polyethylene glycol (PEG)ylated liposome (Lf-PLS) system was developed, and its targeting effect and antitumor efficacy to HCC was also explored. The DOX-loaded Lf-PLS system had spherical or oval vesicles, with mean particle size approximately 100 nm, and had an encapsulation efficiency of 97%. The confocal microscopy and flow cytometry indicated that the cellular uptake of Lf-PLS was significantly higher than that of PEGylated liposome (PLS) in ASGPR-positive cells (P<0.05) but not in ASGPR-negative cells (P>0.05). Cytotoxicity assay by MTT demonstrated that DOX-loaded Lf-PLS showed significantly stronger antiproliferative effects on ASGPR-positive HCC cells than did PLS without the Lf modification (P<0.05). The in vivo antitumor studies on male BALB/c nude mice bearing HepG2 xenografts demonstrated that DOX-loaded Lf-PLS had significantly stronger antitumor efficacy compared with PLS (P<0.05) and free DOX (P<0.05). All these results demonstrated that a DOX-loaded Lf-PLS might have great potential application for HCC-targeting therapy. PMID:26316745

Specific targeting and toxicity of sulphonated aluminium phthalocyanine photosensitised liposomes directed to cells by monoclonal antibody in vitro.

PubMed Central

Morgan, J.; Gray, A. G.; Huehns, E. R.

1989-01-01

A partially purified fraction of the water soluble photosensitive dye sulphonated aluminium phthalocyanine (AlSPc) was encapsulated in liposomes which were then linked to a targeting monoclonal antibody 791T/36 using a heterobifunctional linking agent. The photocytotoxic effects of the liposomes were determined on two cell lines bearing an antigen with which the targeting antibody binds: 791T, an osteosarcoma and C170, a colorectal carcinoma; and a control cell line not bearing the antigen; DW-BCL, an Epstein-Barr virus immortalised B-cell line. Antibody dependent cytotoxicity was observed in 791T and C170 cells and was proportional to the number of antigens on the cells, the AlSPc concentration and the time of exposure to activating red light. No significant toxicity was seen using untargeted liposomes, control cells or free AlSPc fraction under similar conditions. Targeted cells and controls kept in the dark also showed no significant toxicity. A possible mechanism of action is postulated and simple adaptations which demonstrate the versatility of the model are discussed. Some suggestions as to the clinical situations to which this system might be applied in the form of photodynamic therapy (PDT) are made. PMID:2930700

Assessment of plaque vulnerability in atherosclerosis via intravascular photoacoustic imaging of targeted liposomal ICG J-aggregates (Conference Presentation)

NASA Astrophysics Data System (ADS)

Harris, Justin T.; Dumani, Diego S.; Cook, Jason R.; Sokolov, Konstantin V.; Emelianov, Stanislav Y.; Homan, Kimberly A.

2017-03-01

While molecular and cellular imaging can be used to visualize the conventional morphology characteristics of vulnerable plaques, there is a need to monitor other physiological factors correlated with high rupture rates; a high M1 activated macrophage concentration is one such indicator of high plaque vulnerability. Here, we present a molecularly targeted contrast agent for intravascular photoacoustic (IVPA) imaging consisting of liposomes loaded with indocyanine green (ICG) J-aggregates with high absorption at 890 nm, allowing for imaging in the presence of blood. This "Lipo-ICG" was targeted to a biomarker of M1 activated macrophages in vulnerable plaques: folate receptor beta (FRβ). The targeted liposomes accumulate in plaques through areas of endothelial dysfunction, while the liposome encapsulation prevents nonspecific interaction with lipids and endothelium. Lipo-ICG specifically interacts with M1 activated macrophages, causing a spectral shift and change in the 890/780 nm photoacoustic intensity ratio upon breakdown of J-aggregates. This sensing mechanism enables assessment of the M1 activated macrophage concentration, providing a measure of plaque vulnerability. In a pilot in vivo study utilizing ApoE deficient mouse models of atherosclerosis, diseased mice showed increased uptake of FRβ targeted Lipo-ICG in the heart and arteries vs. normal mice. Likewise, targeted Lipo-ICG showed increased uptake vs. two non-targeted controls. Thus, we successfully synthesized a contrast agent to detect M1 activated macrophages in high risk atherosclerotic plaques and exhibited targeting both in vitro and in vivo. This biocompatible agent could enable M1 macrophage detection, allowing better clinical decision making in treatment of atherosclerosis.

Predicting the influence of liposomal lipid composition on liposome size, zeta potential and liposome-induced dendritic cell maturation using a design of experiments approach.

PubMed

Soema, Peter C; Willems, Geert-Jan; Jiskoot, Wim; Amorij, Jean-Pierre; Kersten, Gideon F

2015-08-01

In this study, the effect of liposomal lipid composition on the physicochemical characteristics and adjuvanticity of liposomes was investigated. Using a design of experiments (DoE) approach, peptide-containing liposomes containing various lipids (EPC, DOPE, DOTAP and DC-Chol) and peptide concentrations were formulated. Liposome size and zeta potential were determined for each formulation. Moreover, the adjuvanticity of the liposomes was assessed in an in vitro dendritic cell (DC) model, by quantifying the expression of DC maturation markers CD40, CD80, CD83 and CD86. The acquired data of these liposome characteristics were successfully fitted with regression models, and response contour plots were generated for each response factor. These models were applied to predict a lipid composition that resulted in a liposome with a target zeta potential. Subsequently, the expression of the DC maturation factors for this lipid composition was predicted and tested in vitro; the acquired maturation responses corresponded well with the predicted ones. These results show that a DoE approach can be used to screen various lipids and lipid compositions, and to predict their impact on liposome size, charge and adjuvanticity. Using such an approach may accelerate the formulation development of liposomal vaccine adjuvants. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Development and characterization of CD22-targeted pegylated-liposomal doxorubicin (IL-PLD).

PubMed

O'Donnell, Robert T; Martin, Shiloh M; Ma, Yunpeng; Zamboni, William C; Tuscano, Joseph M

2010-06-01

Non-Hodgkin's lymphoma (NHL) is the sixth most common cause of cancer deaths in the U.S. Most NHLs initially respond well to chemotherapy, but relapse is common and treatment is often limited due to the toxicity of chemotherapeutic agents. Pegylated-liposomal doxorubicin (PLD, Ben Venue Laboratories, Inc), a produces less myelotoxicity than non-liposomal (NL) doxorubicin. To further enhance efficacy and NHL targeting and to decrease toxicity, we conjugated an anti-CD22 monoclonal antibody (HB22.7) to the surface of PLD, thereby creating CD22-targeted immunoliposomal PLD (IL-PLD). HB22.7 was successfully conjugated to PLD and the resulting IL-PLD exhibits specific binding to CD22-expressing cells as assessed by immunofluorescence staining. IL-PLD exhibits more cytotoxicity than PLD in CD22 positive cell lines but does not increase killing of CD22 negative cells. The IC(50) of IL-PLD is 3.1 to 5.4 times lower than that of PLD in CD22+ cell lines while the IC(50) of IL-PLD is equal to that of PLD in CD22- cells. Furthermore, IL-PLD remained bound to the CD22+ cells after washing and continued to exert cytotoxic effects, while PLD and NL- doxorubicin could easily be washed from these cells.

Thermo-responsive magnetic liposomes for hyperthermia-triggered local drug delivery.

PubMed

Dai, Min; Wu, Cong; Fang, Hong-Ming; Li, Li; Yan, Jia-Bao; Zeng, Dan-Lin; Zou, Tao

2017-06-01

We prepared and characterised thermo-responsive magnetic liposomes, which were designed to combine features of magnetic targeting and thermo-responsive control release for hyperthermia-triggered local drug delivery. The particle size and zeta-potential of the thermo-responsive magnetic ammonium bicarbonate (MagABC) liposomes were about 210 nm and -14 mV, respectively. The MagABC liposomes showed encapsulation efficiencies of about 15% and 82% for magnetic nanoparticles (mean crystallite size 12 nm) and doxorubicin (DOX), respectively. The morphology of the MagABC liposomes was visualised using transmission electron microscope (TEM). The MagABC liposomes showed desired thermo-responsive release. The MagABC liposomes, when physically targeted to tumour cells in culture by a permanent magnetic field yielded a substantial increase in intracellular accumulation of DOX as compared to non-magnetic ammonium bicarbonate (ABC) liposomes. This resulted in a parallel increase in cytotoxicity for DOX loaded MagABC liposomes over DOX loaded ABC liposomes in tumour cells.

Hepatocyte-targeted delivery using ph-sensitive liposomes loaded with lactosylnorcantharidin phospholipid complex: preparation, characterization, and therapeutic evaluation in vivo and in vitro.

PubMed

Qiao-ling, Z; Yi, Z; Min, G; Di-jia, Y; Xiao-feng, Z; Yang, L; Jing-yu, X; Ying, W; Zong-lin, G; Kong-lang, X; Ai-jun, Z; Wei-liang, C; Lin-sen, S; Xue-nong, Z; Qiang, Z

2012-01-01

Liposomes loaded with lactosyl-norcantharidin phospholipid complex (LPC) were prepared, in which soybean phosphatidylcholine was used to improve the liposolubility of lactosyl-norcantharidin (Lac-NCTD). The pH-sensitive LPC liposomes (pH-LPC-lips) were obtained by electrostatic adsorption of the carboxymethyl chitosan onto the surface of the liposomes. The in vitro drug release of pH-LPC-lips and LPC-lips was investigated in dissolution media with pH ranging from 1.0 to 8.0. The in vitro antitumor activity and cellular uptake of Lac-NCTD and its liposomes to HepG2 cells were studied. The pH-LPC-lips demonstrated strong cytotoxicity against the cells and easily permeated the cell membrane. The in vivo antitumor activities of Lac-NCTD and its liposomes were evaluated in mice bearing H22 liver tumors. The pH-LPC-lips displayed the best tumor inhibitory effect. The optical imaging results indicated that Cy7- labeled pH-LPC-lips showed excellent hepatocyte specificity in H22 tumor-bearing mice. Therefore, pH-LPC-lips can be regarded as liver-targeting agents that combine targeting and active releasing.

Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy.

PubMed

He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

2014-01-01

Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone-releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer.

Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy

PubMed Central

He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

2014-01-01

Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone–releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer. PMID:25187709

An efficient PEGylated liposomal nanocarrier containing cell-penetrating peptide and pH-sensitive hydrazone bond for enhancing tumor-targeted drug delivery.

PubMed

Ding, Yuan; Sun, Dan; Wang, Gui-Ling; Yang, Hong-Ge; Xu, Hai-Feng; Chen, Jian-Hua; Xie, Ying; Wang, Zhi-Qiang

2015-01-01

Cell-penetrating peptides (CPPs) as small molecular transporters with abilities of cell penetrating, internalization, and endosomal escape have potential prospect in drug delivery systems. However, a bottleneck hampering their application is the poor specificity for cells. By utilizing the function of hydration shell of polyethylene glycol (PEG) and acid sensitivity of hydrazone bond, we constructed a kind of CPP-modified pH-sensitive PEGylated liposomes (CPPL) to improve the selectivity of these peptides for tumor targeting. In CPPL, CPP was directly attached to liposome surfaces via coupling with stearate (STR) to avoid the hindrance of PEG as a linker on the penetrating efficiency of CPP. A PEG derivative by conjugating PEG with STR via acid-degradable hydrazone bond (PEG2000-Hz-STR, PHS) was synthesized. High-performance liquid chromatography and flow cytometry demonstrated that PHS was stable at normal neutral conditions and PEG could be completely cleaved from liposome surface to expose CPP under acidic environments in tumor. An optimal CPP density on liposomes was screened to guaranty a maximum targeting efficiency on tumor cells as well as not being captured by normal cells that consequently lead to a long circulation in blood. In vitro and in vivo studies indicated, in 4 mol% CPP of lipid modified system, that CPP exerted higher efficiency on internalizing the liposomes into targeted subcellular compartments while remaining inactive and free from opsonins at a maximum extent in systemic circulation. The 4% CPPL as a drug delivery system will have great potential in the clinical application of anticancer drugs in future.

An efficient PEGylated liposomal nanocarrier containing cell-penetrating peptide and pH-sensitive hydrazone bond for enhancing tumor-targeted drug delivery

PubMed Central

Ding, Yuan; Sun, Dan; Wang, Gui-Ling; Yang, Hong-Ge; Xu, Hai-Feng; Chen, Jian-Hua; Xie, Ying; Wang, Zhi-Qiang

2015-01-01

Cell-penetrating peptides (CPPs) as small molecular transporters with abilities of cell penetrating, internalization, and endosomal escape have potential prospect in drug delivery systems. However, a bottleneck hampering their application is the poor specificity for cells. By utilizing the function of hydration shell of polyethylene glycol (PEG) and acid sensitivity of hydrazone bond, we constructed a kind of CPP-modified pH-sensitive PEGylated liposomes (CPPL) to improve the selectivity of these peptides for tumor targeting. In CPPL, CPP was directly attached to liposome surfaces via coupling with stearate (STR) to avoid the hindrance of PEG as a linker on the penetrating efficiency of CPP. A PEG derivative by conjugating PEG with STR via acid-degradable hydrazone bond (PEG2000-Hz-STR, PHS) was synthesized. High-performance liquid chromatography and flow cytometry demonstrated that PHS was stable at normal neutral conditions and PEG could be completely cleaved from liposome surface to expose CPP under acidic environments in tumor. An optimal CPP density on liposomes was screened to guaranty a maximum targeting efficiency on tumor cells as well as not being captured by normal cells that consequently lead to a long circulation in blood. In vitro and in vivo studies indicated, in 4 mol% CPP of lipid modified system, that CPP exerted higher efficiency on internalizing the liposomes into targeted subcellular compartments while remaining inactive and free from opsonins at a maximum extent in systemic circulation. The 4% CPPL as a drug delivery system will have great potential in the clinical application of anticancer drugs in future. PMID:26491292

State of the Art of Stimuli-Responsive Liposomes for Cancer Therapy

PubMed Central

Heidarli, Elmira; Dadashzadeh, Simin; Haeri, Azadeh

2017-01-01

Specific delivery of therapeutic agents to solid tumors and their bioavailability at the target site are the most clinically important and challenging goals in cancer therapy. Liposomes are promising nanocarriers and have been well investigated for cancer therapy. In spite of preferred accumulation in tumors via the enhanced permeability and retention (EPR) effect, inefficient drug release at the target site and endosomal entrapment of long circulating liposomes are very important obstacles for achieving maximum anticancer efficacy. Thus, additional strategies such as stimulus-sensitive drug release are necessary to improve efficacy. Stimuli-sensitive liposomes are stable in blood circulation, however, activated by responding to external or internal stimuli and control the cargo release at the target site. This review focuses on state of the art of stimuli-responsive liposomes. Both external stimuli-responsive liposomes, including hyperthermia (HT), magnetic, light, and ultrasound-sensitive liposomes and internal stimuli (pH, reduction, and enzyme) responsive liposomes are covered. PMID:29552041

State of the Art of Stimuli-Responsive Liposomes for Cancer Therapy.

PubMed

Heidarli, Elmira; Dadashzadeh, Simin; Haeri, Azadeh

2017-01-01

Specific delivery of therapeutic agents to solid tumors and their bioavailability at the target site are the most clinically important and challenging goals in cancer therapy. Liposomes are promising nanocarriers and have been well investigated for cancer therapy. In spite of preferred accumulation in tumors via the enhanced permeability and retention (EPR) effect, inefficient drug release at the target site and endosomal entrapment of long circulating liposomes are very important obstacles for achieving maximum anticancer efficacy. Thus, additional strategies such as stimulus-sensitive drug release are necessary to improve efficacy. Stimuli-sensitive liposomes are stable in blood circulation, however, activated by responding to external or internal stimuli and control the cargo release at the target site. This review focuses on state of the art of stimuli-responsive liposomes. Both external stimuli-responsive liposomes, including hyperthermia (HT), magnetic, light, and ultrasound-sensitive liposomes and internal stimuli (pH, reduction, and enzyme) responsive liposomes are covered.

Electrosteric stealth Rivastigmine loaded liposomes for brain targeting: preparation, characterization, ex vivo, bio-distribution and in vivo pharmacokinetic studies.

PubMed

Nageeb El-Helaly, Sara; Abd Elbary, Ahmed; Kassem, Mohamed A; El-Nabarawi, Mohamed A

2017-11-01

Being one of the highly effective drugs in treatment of Alzheimer's disease, Rivastigmine brain targeting is highly demandable, therefore liposomal dispersion of Rivastigmine was prepared containing 2 mol% PEG-DSPE added to Lecithin, Didecyldimethyl ammonium bromide (DDAB), Tween 80 in 1:0.02:0.25 molar ratio. A major challenge during the preparation of liposomes is maintaining a stable formulation, therefore the aim of our study was to increase liposomal stability by addition of DDAB to give an electrostatic stability and PEG-DSPE to increase stability by steric hindrance, yielding what we called an electrosteric stealth (ESS) liposomes. A medium nano-sized liposome (478 ± 4.94 nm) with a nearly neutral zeta potential (ZP, -8 ± 0.2 mV) and an entrapment efficiency percentage of 48 ± 6.22 was prepared. Stability studies showed no major alteration after three months storage period concerning particle size, polydispersity index, ZP, entrapment efficiency and in vitro release study confirming the successful formation of a stable liposomes. No histopathological alteration was recorded for ESS liposomes of the sheep nasal mucosa. While ESS liposomes showed higher % of drug permeating through the sheep nasal mucosa (48.6%) than the drug solution (28.7%). On completing the in vivo pharmacokinetic studies of 36 rabbits showed 424.2% relative bioavailability of the mean plasma levels of the formula ESS compared to that of RHT intranasal solution and 486% relative bioavailability of the mean brain levels.

Liposome-Based Nanomedicine Therapeutics for Rheumatoid Arthritis.

PubMed

Rahman, Mahfoozur; Beg, Sarwar; Anwar, Firoz; Kumar, Vikas; Ubale, Ruhi; Addo, Richard T; Ali, Raisuddin; Akhter, Sohail

2017-01-01

Rheumatoid arthritis (RA) is a very painful severe autoimmune disease with complex pathology characterized by progressive chronic inflammation, and devastation of the synovium, cartilage, and other joint-associated structures. Significant advances in research in the area of pathophysiology, diagnosis, drug development, and targeted delivery have led to improved RA therapy and better patient compliance. Targeted drug delivery using liposomal nanomedicines significantly alleviate the challenges with conventional anti-RA medications such as off-target effects, short biological half-life, poor bioavailability, high dose-related toxicity, etc. Liposomal nanomedicines in RA drug targeting offer the opportunity for passive targeting [based on size and polyethylene glycol (PEG)-ylation-mediated enhanced permeability and retention] and active targeting (ligation with antibody or peptides, etc.) and encapsulation of lipophilic, hydrophilic drugs, and/or combinational drugs. However, it has been found recently that such injectable nanomedicines raise the concern of an adverse immune phenomenon called complement activationrelated pseudo allergy (CARPA) and failure of therapy on multiple doses due to accelerated body clearance caused many by anti-PEG immunoglobulin M. To ensure safety and efficacy of RA therapy, these need to be considered along with the common formulation quality parameters. Here, we discuss nanotherapeutic targeting in RA therapy using liposomes. Liposomal nanoparticles are investigated for individual anti-RA drug categories. CARPA issues and pathophysiology with such nanomedicines are also discussed in detail.

Hyaluronic Acid Surface Modified Liposomes Prepared via Orthogonal Aminoxy Coupling: Synthesis of Nontoxic Aminoxylipids Based on Symmetrically α-Branched Fatty Acids, Preparation of Liposomes by Microfluidic Mixing, and Targeting to Cancer Cells Expressing CD44.

PubMed

Bartheldyová, Eliška; Effenberg, Roman; Mašek, Josef; Procházka, Lubomír; Knötigová, Pavlína Turánek; Kulich, Pavel; Hubatka, František; Velínská, Kamila; Zelníčková, Jaroslava; Zouharová, Darina; Fojtíková, Martina; Hrebík, Dominik; Plevka, Pavel; Mikulík, Robert; Miller, Andrew D; Macaulay, Stuart; Zyka, Daniel; Drož, Ladislav; Raška, Milan; Ledvina, Miroslav; Turánek, Jaroslav

2018-06-25

New synthetic aminoxy lipids are designed and synthesized as building blocks for the formulation of functionalized nanoliposomes by microfluidization using a NanoAssemblr. Orthogonal binding of hyaluronic acid onto the outer surface of functionalized nanoliposomes via aminoxy coupling ( N-oxy ligation) is achieved at hemiacetal function of hyaluronic acid and the structure of hyaluronic acid-liposomes is visualized by transmission electron microscopy and cryotransmission electron microscopy. Observed structures are in a good correlation with data obtained by dynamic light scattering (size and ζ-potential). In vitro experiments on cell lines expressing CD44 receptors demonstrate selective internalization of fluorochrome-labeled hyaluronic acid-liposomes, while cells with down regulated CD44 receptor levels exhibit very low internalization of hyaluronic acid-liposomes. A method based on microfluidization mixing was developed for preparation of monodispersive unilamellar liposomes containing aminoxy lipids and orthogonal binding of hyaluronic acid onto the liposomal surface was demonstrated. These hyaluronic acid-liposomes represent a potentially new drug delivery platform for CD44-targeted anticancer drugs as well as for immunotherapeutics and vaccines.

Safe and efficient pH sensitive tumor targeting modified liposomes with minimal cytotoxicity.

PubMed

Wang, Lilin; Geng, Di; Su, Haijia

2014-11-01

Incorporating the pH-sensitivity of octylamine grafted poly aspartic acid (PASP) with the biocompatibility of liposomes, a novel pH sensitive drug delivery system, octylamine-graft-PASP (PASP-g-C8) modified liposomes (OPLPs), was obtained. Since hydrophobic chains have been grafted into PASP backbones, the octylamine chain could act as the "anchor" to implant onto liposomes. The structure of PASP-g-C8, involving long-chain and hydrophobic anchors can significantly enhance the stability of the drug carrier. The shortcoming of single PASP chain modified liposomes (PLPs), that cannot sustain a slow and controlled release especially in a physiological pH solution (resembling normal tissues of pH 7.4) is thus overcome. Drug release experiments were carried out and the result showed that OPLPs sustained a slow and steady release in comparison with PLPs in the physiological pH 7.4 environment. However, OPLPs can provide a fast release in subacid environment (pH 5.0 of resembled tumor tissues). The results of diameter analysis and zeta potential demonstrated that OPLPs presented a larger diameter and higher electronegativity. Furthermore, in the "chain-anchor" structure of PASP-g-C8, the degree of substitution (DS) of the "anchor" is a remarkable factor to alter the pH-sensitivity of OPLPs. The in vitro tumor inhibition and cell toxicity studies revealed that tumor cells treated with OPLPs survived only 35.0% after 48 h whereas normal cells survived 100% in the same condition. The pH sensitive OPLPs are promising tumor targeting drug delivery with high tumor inhibition and insignificant cytotoxicity. Copyright © 2014. Published by Elsevier B.V.

Tumor-specific pH-responsive peptide-modified pH-sensitive liposomes containing doxorubicin for enhancing glioma targeting and anti-tumor activity.

PubMed

Zhao, Yang; Ren, Wei; Zhong, Ting; Zhang, Shuang; Huang, Dan; Guo, Yang; Yao, Xin; Wang, Chao; Zhang, Wei-Qiang; Zhang, Xuan; Zhang, Qiang

2016-01-28

The pH environment in gliomas is acidic. Therefore, in the present research, we selected our previously reported tumor-specific pH-responsive peptide H7K(R2)2 as a targeting ligand, which could respond to the acidic pH environment in gliomas, possessing CPP characteristics. The pH-sensitive liposomes were selected as carriers which could also respond to the acidic pH environment in gliomas triggering encapsulated drug release from these pH-sensitive liposomes. The H7K(R2)2-modified pH-sensitive liposomes containing doxorubicin (DOX-PSL-H7K(R2)2) were designed and prepared in order to evaluate their potential targeting of glioma tumor cells and their anti-tumor activity in mice with glioma tumor cells. DOX-PSL-H7K(R2)2 was prepared by the thin-film hydration method followed by remote loading using an ammonium sulfate gradient method. The in vitro release of DOX from pH-sensitive liposomes was tested and the in vitro targeting characteristics of H7K(R2)2-modified liposomes regarding C6 (rat C6 glioma cells) and U87-MG (human glioblastoma cells) were evaluated. The in vivo anti-tumor activity of DOX-PSL-H7K(R2)2 was also investigated in C6 tumor-bearing mice and in U87-MG orthotopic tumor-bearing nude mice. A specific targeting effect triggered by an acidic pH was observed in our in vitro experiments in C6 and U87-MG glioma cells. The pH-triggered DOX release from the pH-sensitive liposomes under acidic conditions was also confirmed in our in vitro experiment. Anti-tumor activity of DOX-PSL-H7K(R2)2 was found in C6 tumor-bearing mice and U87-MG orthotopic tumor-bearing nude mice in in vivo experiments. The antiangiogenic activity of DOX-PSL-H7K(R2)2 was confirmed in C6 tumor-bearing mice in the in vivo experiment. These H7K(R2)2-modified pH-sensitive liposomes containing anti-tumor drugs developed in this study are a promising delivery system involving the response stimuli at the acidic pH in the glioma tumor microenvironment and are suitable for anti-tumor therapy

A FRET-guided, NIR-responsive bubble-generating liposomal system for in vivo targeted therapy with spatially and temporally precise controlled release.

PubMed

Chuang, Er-Yuan; Lin, Chia-Chen; Chen, Ko-Jie; Wan, De-Hui; Lin, Kun-Ju; Ho, Yi-Cheng; Lin, Po-Yen; Sung, Hsing-Wen

2016-07-01

The nonspecific distribution of therapeutic agents and nontargeted heating commonly produce undesirable side effects during cancer treatment since the optimal timing of triggering the carrier systems is unknown. This work proposes a multifunctional liposomal system that can intracellularly and simultaneously deliver the therapeutic drug doxorubicin (DOX), heat, and a bubble-generating agent (ammonium bicarbonate, ABC) into targeted tumor cells to have a cytotoxic effect. Gold nanocages that are encapsulated in liposomes effectively convert near-infrared light irradiation into localized heat, which causes the decomposition of ABC and generates CO2 bubbles, rapidly triggering the release of DOX. Additionally, a hybridized Mucin-1 aptamer is conjugated on the surface of the test liposomes, which then function as a recognition probe to enhance the uptake of those liposomes by cells, and as a molecular beacon to signal when the internalized particles have been maximized, which is the optimal time for photothermally triggering the release of the drug following the systemic administration of the liposomes. Empirical results reveal that this combined treatment effectively controls targeted drug release in a spatially and temporally precise fashion and so significantly increases the potency of the drug while minimizing unwanted side effects, making it a promising treatment for cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Silymarin liposomes improves oral bioavailability of silybin besides targeting hepatocytes, and immune cells.

PubMed

Kumar, Nitesh; Rai, Amita; Reddy, Neetinkumar D; Raj, P Vasanth; Jain, Prateek; Deshpande, Praful; Mathew, Geetha; Kutty, N Gopalan; Udupa, Nayanabhirama; Rao, C Mallikarjuna

2014-10-01

Silymarin, a hepatoprotective agent, has poor oral bioavailability. However, the current dosage form of the drug does not target the liver and inflammatory cells selectively. The aim of the present study was to develop lecithin-based carrier system of silymarin by incorporating phytosomal-liposomal approach to increase its oral bioavailability and to make it target-specific to the liver for enhanced hepatoprotection. The formulation was prepared by film hydration method. Release of drug was assessed at pH 1.2 and 7.4. Formulation was assessed for in vitro hepatoprotection on Chang liver cells, lipopolysaccharide-induced reactive oxygen species (ROS) production by RAW 267.4 (murine macrophages), in vivo efficacy against paracetamol-induced hepatotoxicity and pharmacokinetic study by oral route in Wistar rat. The formulation showed maximum entrapment (55%) for a lecithin-cholesterol ratio of 6:1. Comparative release profile of formulation was better than silymarin at pH 1.2 and pH 7.4. In vitro studies showed a better hepatoprotection efficacy for formulation (one and half times) and better prevention of ROS production (ten times) compared to silymarin. In in vivo model, paracetamol showed significant hepatotoxicity in Wistar rats assessed through LFT, antioxidant markers and inflammatory markers. The formulation was found more efficacious than silymarin suspension in protecting the liver against paracetamol toxicity and the associated inflammatory conditions. The liposomal formulation yielded a three and half fold higher bioavailability of silymarin as compared with silymarin suspension. Incorporating the phytosomal form of silymarin in liposomal carrier system increased the oral bioavailability and showed better hepatoprotection and better anti-inflammatory effects compared with silymarin suspension. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Cationic liposomes as vaccine adjuvants.

PubMed

Christensen, Dennis; Korsholm, Karen S; Rosenkrands, Ida; Lindenstrøm, Thomas; Andersen, Peter; Agger, Else Marie

2007-10-01

Cationic liposomes are lipid-bilayer vesicles with a positive surface charge that have re-emerged as a promising new adjuvant technology. Although there is some evidence that cationic liposomes themselves can improve the immune response against coadministered vaccine antigens, their main functions are to protect the antigens from clearance in the body and deliver the antigens to professional antigen-presenting cells. In addition, cationic liposomes can be used to introduce immunomodulators to enhance and modulate the immune response in a desirable direction and, thereby, represent an efficient tool when designing tailor-made adjuvants for specific disease targets. In this article we review the recent progress on cationic liposomes as vehicles, enhancing the effect of immunomodulators and the presentation of vaccine antigens.

PLGA/liposome hybrid nanoparticles for short-chain ceramide delivery.

PubMed

Zou, Peng; Stern, Stephan T; Sun, Duxin

2014-03-01

Rapid premature release of lipophilic drugs from liposomal lipid bilayer to plasma proteins and biological membranes is a challenge for targeted drug delivery. The purpose of this study is to reduce premature release of lipophilic short-chain ceramides by encapsulating ceramides into liposomal aqueous interior with the aid of poly (lactic-coglycolicacid) (PLGA). BODIPY FL labeled ceramide (FL-ceramide) and BODIPY-TR labeled ceramide (TR-ceramide) were encapsulated into carboxy-terminated PLGA nanoparticles. The negatively charged PLGA nanoparticles were then encapsulated into cationic liposomes to obtain PLGA/liposome hybrids. As a control, FL-ceramide and/or TR ceramide co-loaded liposomes without PLGA were prepared. The release of ceramides from PLGA/liposome hybrids and liposomes in rat plasma, cultured MDA-MB-231 cells, and rat blood circulation was compared using fluorescence resonance energy transfer (FRET) between FL-ceramide (donor) and TR-ceramide (acceptor). FRET analysis showed that FL-ceramide and TR-ceramide in liposomal lipid bilayer were rapidly released during incubation with rat plasma. In contrast, the FL-ceramide and TR-ceramide in PLGA/liposome hybrids showed extended release. FRET images of cells revealed that ceramides in liposomal bilayer were rapidly transferred to cell membranes. In contrast, ceramides in PLGA/liposome hybrids were internalized into cells with nanoparticles simultaneously. Upon intravenous administration to rats, ceramides encapsulated in liposomal bilayer were completely released in 2 min. In contrast, ceramides encapsulated in the PLGA core were retained in PLGA/liposome hybrids for 4 h. The PLGA/liposome hybrid nanoparticles reduced in vitro and in vivo premature release of ceramides and offer a viable platform for targeted delivery of lipophilic drugs.

PLGA/liposome hybrid nanoparticles for short-chain ceramide delivery

PubMed Central

Zou, Peng; Stern, Stephan T.; Sun, Duxin

2014-01-01

Purpose Rapid premature release of lipophilic drugs from liposomal lipid bilayer to plasma proteins and biological membranes is a challenge for targeted drug delivery. The purpose of this study is to reduce premature release of lipophilic short-chain ceramides by encapsulating ceramides into liposomal aqueous interior with the aid of poly( lactic-coglycolicacid) (PLGA). Methods BODIPY FL labeled ceramide (FL-ceramide) and BODIPY-TR labeled ceramide (TR-ceramide) were encapsulated into carboxy-terminated PLGA nanoparticles. The negatively charged PLGA nanoparticles were then encapsulated into cationic liposomes to obtain PLGA/liposome hybrids. As a control, FL-ceramide and/or TR ceramide co-loaded liposomes without PLGA were prepared. The release of ceramides from PLGA/liposome hybrids and liposomes in rat plasma, cultured MDA-MB-231 cells, and rat blood circulation was compared using fluorescence resonance energy transfer (FRET) between FL-ceramide (donor) and TR-ceramide (acceptor). Results FRET analysis showed that FL-ceramide and TR-ceramide in liposomal lipid bilayer were rapidly released during incubation with rat plasma. In contrast, the FL-ceramide and TR-ceramide in PLGA/liposome hybrids showed extended release. FRET images of cells revealed that ceramides in liposomal bilayer were rapidly transferred to cell membranes. In contrast, ceramides in PLGA/liposome hybrids were internalized into cells with nanoparticles simultaneously. Upon intravenous administration to rats, ceramides encapsulated in liposomal bilayer were completely released in 2 minutes. In contrast, ceramides encapsulated in the PLGA core were retained in PLGA/liposome hybrids for 4 hours. Conclusions The PLGA/liposome hybrid nanoparticles reduced in vitro and in vivo premature release of ceramides and offer a viable platform for targeted delivery of lipophilic drugs. PMID:24065591

The construction of the multifunctional targeting ursolic acids liposomes and its apoptosis effects to C6 glioma stem cells

PubMed Central

Ying, Xue; Wang, Yahua; Xu, Haolun; Li, Xia; Yan, Helu; Tang, Hui; Wen, Chen; Li, Yingchun

2017-01-01

Brain gliomas, one of the most fatal tumors to human, severely threat the health and life of human. They are capable of extremely strong invasion ability. And invasive glioma cells could rapidly penetrate into normal brain tissues and break them. We prepared a kind of functional liposomes, which could be transported acrossing the blood-brain barrier (BBB) and afterwards induce the apoptosis of glioma stem cells. In this research, we chose ursolic acids (UA) as an anti-cancer drug to inhibit the growth of C6 glioma cells, while epigallocatechin 3-gallate(EGCG) as the agent that could induce the apoptosis of C6 glioma stem cells. With the targeting ability of MAN, the liposomes could be delivered through the BBB and finally were concentrated on the brain gliomas. Cell experiments in vitro demonstrated that the functional liposomes were able to significantly enhance the anti-cancer effects of the drugs due to promoting the apoptosis and endocytosis effects of C6 glioma cells and C6 glioma stem cells at the same time. Furthermore, the evaluations through animal models showed that the drugs could obviously prolong the survival period of brain glioma-bearing mice and inhibit the tumor growth. Consequently, multifunctional targeting ursolic acids liposomes could potentially improve the therapeutic effects on C6 glioma cells and C6 glioma stem cells. PMID:28969057

A Label-Free Fluorescent Array Sensor Utilizing Liposome Encapsulating Calcein for Discriminating Target Proteins by Principal Component Analysis

PubMed Central

Imamura, Ryota; Murata, Naoki; Shimanouchi, Toshinori; Yamashita, Kaoru; Fukuzawa, Masayuki; Noda, Minoru

2017-01-01

A new fluorescent arrayed biosensor has been developed to discriminate species and concentrations of target proteins by using plural different phospholipid liposome species encapsulating fluorescent molecules, utilizing differences in permeation of the fluorescent molecules through the membrane to modulate liposome-target protein interactions. This approach proposes a basically new label-free fluorescent sensor, compared with the common technique of developed fluorescent array sensors with labeling. We have confirmed a high output intensity of fluorescence emission related to characteristics of the fluorescent molecules dependent on their concentrations when they leak from inside the liposomes through the perturbed lipid membrane. After taking an array image of the fluorescence emission from the sensor using a CMOS imager, the output intensities of the fluorescence were analyzed by a principal component analysis (PCA) statistical method. It is found from PCA plots that different protein species with several concentrations were successfully discriminated by using the different lipid membranes with high cumulative contribution ratio. We also confirmed that the accuracy of the discrimination by the array sensor with a single shot is higher than that of a single sensor with multiple shots. PMID:28714873

A Label-Free Fluorescent Array Sensor Utilizing Liposome Encapsulating Calcein for Discriminating Target Proteins by Principal Component Analysis.

PubMed

Imamura, Ryota; Murata, Naoki; Shimanouchi, Toshinori; Yamashita, Kaoru; Fukuzawa, Masayuki; Noda, Minoru

2017-07-15

A new fluorescent arrayed biosensor has been developed to discriminate species and concentrations of target proteins by using plural different phospholipid liposome species encapsulating fluorescent molecules, utilizing differences in permeation of the fluorescent molecules through the membrane to modulate liposome-target protein interactions. This approach proposes a basically new label-free fluorescent sensor, compared with the common technique of developed fluorescent array sensors with labeling. We have confirmed a high output intensity of fluorescence emission related to characteristics of the fluorescent molecules dependent on their concentrations when they leak from inside the liposomes through the perturbed lipid membrane. After taking an array image of the fluorescence emission from the sensor using a CMOS imager, the output intensities of the fluorescence were analyzed by a principal component analysis (PCA) statistical method. It is found from PCA plots that different protein species with several concentrations were successfully discriminated by using the different lipid membranes with high cumulative contribution ratio. We also confirmed that the accuracy of the discrimination by the array sensor with a single shot is higher than that of a single sensor with multiple shots.

Hepatocellular carcinoma-targeted effect of configurations and groups of glycyrrhetinic acid by evaluation of its derivative-modified liposomes.

PubMed

Sun, Yuqi; Dai, Chunmei; Yin, Meilin; Lu, Jinghua; Hu, Haiyang; Chen, Dawei

2018-01-01

There are abundant glycyrrhetinic acid (GA) receptors on the cellular membrane of hepatocytes and hepatocellular carcinoma (HCC) cells. The receptor binding effect might be related to the structure of the guiding molecule. GA exists in two stereoisomers with C3-hydroxyl and C11-carbonyl active groups. The objective of this study was to investigate the relationship between the HCC-targeted effect and the configurations and groups of GA. Different GA derivatives (18β-GA, 18α-GA, 3-acetyl-18β-GA [3-Ace-GA] and 11-deoxy-18β-GA [11-Deo-GA]) were used to investigate the targeting effect of GA's configurations and groups on HCC cells. The EC 50 values of competition to binding sites and the ratio of specific binding in HepG2 cells showed that 18β-GA and 3-Ace-GA demonstrated significant competitive effect with fluorescein isothiocyanate (FITC)-labeled GA. Then, the GA derivatives were distearoyl-phosphatidylethanolamine (DSPE)-PEGylated. 18β-GA-, 18α-GA-, 3-Ace-GA-and 11-Deo-GA-modified liposomes were prepared and characterized by size, zeta potential, encapsulation efficiency, loading capacity, leakage and membrane stability. Evaluation on the cellular location in vitro and tumor targeting in vivo was carried out. Compared to common long-circulation liposome (PEG-Lip), more 18β-GA- and 3-Ace-GA-modified liposomes aggregated around HepG2 cells in vitro in short time and transferred into HCC tumors in vivo for a longer time. The β-configuration hydrogen atom on C18 position of GA played the most important role on the targeting effect. C11-carbonyl and C3-hydroxy groups of GA have certain and little influence on targeting action to HCC, respectively. In general, GA might be a promising targeting molecule for the research on liver diseases and hepatoma therapy.

Liposomal Drug Delivery System for Cancer Therapy: Advancement and Patents.

PubMed

Jha, Sheetal; Sharma, Pramod K; Malviya, Rishabha

2016-01-01

In this review article, authors reviewed about the liposomes which are amongst various drug delivering systems for the delivery of the therapeutic agents at the target site. Advances in liposomal drug delivery systems for the cancer therapy have enhanced the therapeutic levels of the anticancer moieties. Liposomes show promising action on the tumor by incorporating less amount of drug at the target site, with minimum toxic effect and maximum therapeutic effect and thereby enhancing the bioavailability. Liposome-based drug delivery systems provide the potential to elevate the effect of drug concentration in tumor cells. Manuscript briefly describes the role of liposomes in cancer therapy and various patents based on the same. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Phosphatidylserine-targeted liposome for enhanced glioma-selective imaging.

PubMed

Zhang, Liang; Habib, Amyn A; Zhao, Dawen

2016-06-21

Phosphatidylserine (PS), which is normally intracellular, becomes exposed on the outer surface of viable endothelial cells (ECs) of tumor vasculature. Utilizing a PS-targeting antibody, we have recently established a PS-targeted liposomal (PS-L) nanoplatform that has demonstrated to be highly tumor-selective. Because of the vascular lumen-exposed PS that is immediately accessible without a need to penetrate the intact blood brain barrier (BBB), we hypothesize that the systemically administered PS-L binds specifically to tumor vascular ECs, becomes subsequently internalized into the cells and then enables its cargos to be efficiently delivered to glioma parenchyma. To test this, we exploited the dual MRI/optical imaging contrast agents-loaded PS-L and injected it intravenously into mice bearing intracranial U87 glioma. At 24 h, both in vivo optical imaging and MRI depicted enhanced tumor contrast, distinct from the surrounding normal brain. Intriguingly, longitudinal MRI revealed temporal and spatial intratumoral distribution of the PS-L by following MRI contrast changes, which appeared punctate in tumor periphery at an earlier time point (4 h), but became clustering and disseminated throughout the tumor at 24 h post injection. Importantly, glioma-targeting specificity of the PS-L was antigen specific, since a control probe of irrelevant specificity showed minimal accumulation in the glioma. Together, these results indicate that the PS-L nanoplatform enables the enhanced, glioma-targeted delivery of imaging contrast agents by crossing the tumor BBB efficiently, which may also serve as a useful nanoplatform for anti-glioma drugs.

pH-Triggered Echogenicity and Contents Release from Liposomes

PubMed Central

2015-01-01

Liposomes are representative lipid nanoparticles widely used for delivering anticancer drugs, DNA fragments, or siRNA to cancer cells. Upon targeting, various internal and external triggers have been used to increase the rate for contents release from the liposomes. Among the internal triggers, decreased pH within the cellular lysosomes has been successfully used to enhance the rate for releasing contents. However, imparting pH sensitivity to liposomes requires the synthesis of specialized lipids with structures that are substantially modified at a reduced pH. Herein, we report an alternative strategy to render liposomes pH sensitive by encapsulating a precursor which generates gas bubbles in situ in response to acidic pH. The disturbance created by the escaping gas bubbles leads to the rapid release of the encapsulated contents from the liposomes. Atomic force microscopic studies indicate that the liposomal structure is destroyed at a reduced pH. The gas bubbles also render the liposomes echogenic, allowing ultrasound imaging. To demonstrate the applicability of this strategy, we have successfully targeted doxorubicin-encapsulated liposomes to the pancreatic ductal carcinoma cells that overexpress the folate receptor on the surface. In response to the decreased pH in the lysosomes, the encapsulated anticancer drug is efficiently released. Contents released from these liposomes are further enhanced by the application of continuous wave ultrasound (1 MHz), resulting in substantially reduced viability for the pancreatic cancer cells (14%). PMID:25271780

pH-triggered echogenicity and contents release from liposomes.

PubMed

Nahire, Rahul; Hossain, Rayat; Patel, Rupa; Paul, Shirshendu; Meghnani, Varsha; Ambre, Avinash H; Gange, Kara N; Katti, Kalpana S; Leclerc, Estelle; Srivastava, D K; Sarkar, Kausik; Mallik, Sanku

2014-11-03

Liposomes are representative lipid nanoparticles widely used for delivering anticancer drugs, DNA fragments, or siRNA to cancer cells. Upon targeting, various internal and external triggers have been used to increase the rate for contents release from the liposomes. Among the internal triggers, decreased pH within the cellular lysosomes has been successfully used to enhance the rate for releasing contents. However, imparting pH sensitivity to liposomes requires the synthesis of specialized lipids with structures that are substantially modified at a reduced pH. Herein, we report an alternative strategy to render liposomes pH sensitive by encapsulating a precursor which generates gas bubbles in situ in response to acidic pH. The disturbance created by the escaping gas bubbles leads to the rapid release of the encapsulated contents from the liposomes. Atomic force microscopic studies indicate that the liposomal structure is destroyed at a reduced pH. The gas bubbles also render the liposomes echogenic, allowing ultrasound imaging. To demonstrate the applicability of this strategy, we have successfully targeted doxorubicin-encapsulated liposomes to the pancreatic ductal carcinoma cells that overexpress the folate receptor on the surface. In response to the decreased pH in the lysosomes, the encapsulated anticancer drug is efficiently released. Contents released from these liposomes are further enhanced by the application of continuous wave ultrasound (1 MHz), resulting in substantially reduced viability for the pancreatic cancer cells (14%).

pH-Sensitive Liposomes: Acid-Induced Liposome Fusion

NASA Astrophysics Data System (ADS)

Connor, Jerome; Yatvin, Milton B.; Huang, Leaf

1984-03-01

Sonicated unilamellar liposomes containing phosphatidylethanolamine and palmitoylhomocysteine fuse rapidly when the medium pH is lowered from 7 to 5. Liposome fusion was demonstrated by (i) mixing of the liposomal lipids as shown by resonance energy transfer, (ii) gel filtration, and (iii) electron microscopy. The pH-sensitive fusion of liposomes was observed only when palmitoylhomocysteine (>= 20 mol%) was present in the liposomes. The presence of phosphatidyl-ethanolamine in the liposomes greatly enhanced fusion whereas the presence of phosphatidylcholine inhibited fusion. During fusion of liposomes containing phosphatidylethanolamine and palmitoylhomocysteine (8:2, mol/mol), almost all of the encapsulated calcein was released. Inclusion of cholesterol (40 mol%) in the liposomes substantially decreased leakage without impairing fusion.

A novel glycyrrhetinic acid-modified oxaliplatin liposome for liver-targeting and in vitro/vivo evaluation

PubMed Central

Chen, Jingde; Jiang, Hong; Wu, Yin; Li, Yandong; Gao, Yong

2015-01-01

In this study, oxaliplatin (OX) liposomes surface-modified with glycyrrhetinic acid (GA) were developed by the film-dispersion method. Their morphology, physical and chemical properties, and in vitro release performance were investigated. The transmission electron microscope (TEM) image showed that most liposomes were spherical particles with similar size and uniform dispersion. Both OX-liposomes and GA-OX-liposomes had an average size of 90 nm. They were negatively charged, with zeta potentials of −20.6 and −21.3 mV, respectively, and the entrapment efficiency values of both were higher than 94%. In vitro data showed that the application of liposomes could prolong the OX release. The relatively high correlation coefficient values obtained from analyzing the amount of drug released versus the square root of time depicted that release followed the Weibull model. No significant changes were observed after the addition of GA to the liposomes. In vivo, the relatively long time to reach the maximum plasma concentration of OX-liposomes suggested a sustained-release profile of liposomes, which was consistent with the results of the in vitro release study. The increased area under the curve and maximum plasma concentration of OX-liposomes and GA-OX-liposomes demonstrated an increased absorption. The drug concentration in tissues indicated that the GA-modified liposomes delivered OX mainly to liver after intravenous administration. In addition, no severe signs, such as appearance of epithelial necrosis or sloughing of epithelial cells, were detected in histology studies. PMID:25945038

Heparin octasaccharide decoy liposomes inhibit replication of multiple viruses

PubMed Central

Hendricks, Gabriel L.; Velazquez, Lourdes; Pham, Serena; Qaisar, Natasha; Delaney, James C.; Viswanathan, Karthik; Albers, Leila; Comolli, James C.; Shriver, Zachary; Knipe, David M.; Kurt-Jones, Evelyn A.; Fygenson, Deborah K.; Trevejo, Jose M.

2016-01-01

Heparan sulfate (HS) is a ubiquitous glycosaminoglycan that serves as a cellular attachment site for a number of significant human pathogens, including respiratory syncytial virus (RSV), human parainfluenza virus 3 (hPIV3), and herpes simplex virus (HSV). Decoy receptors can target pathogens by binding to the receptor pocket on viral attachment proteins, acting as ‘molecular sinks’ and preventing the pathogen from binding to susceptible host cells. Decoy receptors functionalized with HS could bind to pathogens and prevent infection, so we generated decoy liposomes displaying HS-octasaccharide (HS-octa). These decoy liposomes significantly inhibited RSV, hPIV3, and HSV infectivity in vitro to a greater degree than the original HS-octa building block. The degree of inhibition correlated with the density of HS-octa displayed on the liposome surface. Decoy liposomes with HS-octa inhibited infection of viruses to a greater extent than either full-length heparin or HS-octa alone. Decoy liposomes were effective when added prior to infection or following the initial infection of cells in vitro. By targeting the well-conserved receptor-binding sites of HS-binding viruses, decoy liposomes functionalized with HS-octa are a promising therapeutic antiviral agent and illustrate the utility of the liposome delivery platform. PMID:25637710

Heparin octasaccharide decoy liposomes inhibit replication of multiple viruses.

PubMed

Hendricks, Gabriel L; Velazquez, Lourdes; Pham, Serena; Qaisar, Natasha; Delaney, James C; Viswanathan, Karthik; Albers, Leila; Comolli, James C; Shriver, Zachary; Knipe, David M; Kurt-Jones, Evelyn A; Fygenson, Deborah K; Trevejo, Jose M; Wang, Jennifer P; Finberg, Robert W

2015-04-01

Heparan sulfate (HS) is a ubiquitous glycosaminoglycan that serves as a cellular attachment site for a number of significant human pathogens, including respiratory syncytial virus (RSV), human parainfluenza virus 3 (hPIV3), and herpes simplex virus (HSV). Decoy receptors can target pathogens by binding to the receptor pocket on viral attachment proteins, acting as 'molecular sinks' and preventing the pathogen from binding to susceptible host cells. Decoy receptors functionalized with HS could bind to pathogens and prevent infection, so we generated decoy liposomes displaying HS-octasaccharide (HS-octa). These decoy liposomes significantly inhibited RSV, hPIV3, and HSV infectivity in vitro to a greater degree than the original HS-octa building block. The degree of inhibition correlated with the density of HS-octa displayed on the liposome surface. Decoy liposomes with HS-octa inhibited infection of viruses to a greater extent than either full-length heparin or HS-octa alone. Decoy liposomes were effective when added prior to infection or following the initial infection of cells in vitro. By targeting the well-conserved receptor-binding sites of HS-binding viruses, decoy liposomes functionalized with HS-octa are a promising therapeutic antiviral agent and illustrate the utility of the liposome delivery platform. Copyright © 2015 Elsevier B.V. All rights reserved.

Copper-64 Labeled Liposomes for Imaging Bone Marrow

PubMed Central

Lee, Sang-gyu; Gangangari, Kishore; Kalidindi, Teja Muralidhar; Punzalan, Blesida; Larson, Steven M.; Pillarsetty, Naga Vara Kishore

2016-01-01

Introduction Bone marrow is the soft tissue compartment inside the bones made up of hematopoietic cells, adipocytes, stromal cells, phagocytic cells, stem cells, and sinusoids. While [18F]-FLT has been utilized to image proliferative marrow, to date, there are no reports of particle based positron emission tomography (PET) imaging agents for imaging bone marrow. We have developed copper-64 labeled liposomal formulation that selectively targets bone marrow and therefore serves as an efficient PET probe for imaging bone marrow. Methods Optimized liposomal formulations were prepared with succinyl PE, DSPC, cholesterol, and mPEG-DSPE (69:39:1:10:0.1) with diameters of 90 and 140 nm, and were doped with DOTA-Bn-DSPE for stable 64Cu incorporation into liposomes. Results PET imaging and biodistribution studies with 64Cu-labeled liposomes indicate that accumulation in bone marrow was as high as 15.18 ± 3.69 %ID/g for 90 nm liposomes and 7.01 ± 0.92 %ID/g for 140 nm liposomes at 24 h post-administration. In vivo biodistribution studies in tumor-bearing mice indicate that the uptake of 90 nm particles is approximately 0.89 ± 0.48 %ID/g in tumor and 14.22 ± 8.07 %ID/g in bone marrow, but respective values for Doxil® like liposomes are 0.83 ± 0.49 %ID/g and 2.23 ± 1.00 %ID/g. Conclusion Our results indicate that our novel PET labeled liposomes target bone marrow with very high efficiency and therefore can function as efficient bone marrow imaging agents. PMID:27694056

Incorporation of a selective sigma-2 receptor ligand enhances uptake of liposomes by multiple cancer cells

PubMed Central

Zhang, Yifei; Huang, Yixian; Zhang, Peng; Gao, Xiang; Gibbs, Robert B; Li, Song

2012-01-01

Background: The sigma-2 receptor is an attractive target for tumor imaging and targeted therapy because it is overexpressed in multiple types of solid tumors, including prostate cancer, breast cancer, and lung cancer. SV119 is a synthetic small molecule that binds to sigma-2 receptors with high affinity and specificity. This study investigates the utility of SV119 in mediating the selective targeting of liposomal vectors in various types of cancer cells. Methods: SV119 was covalently linked with polyethylene glycol-dioleyl amido aspartic acid conjugate (PEG-DOA) to generate a novel functional lipid, SV119-PEG-DOA. This lipid was utilized for the preparation of targeted liposomes to enhance their uptake by cancer cells. Liposomes with various SV119 densities (0, 1, 3, and 5 mole%) were prepared and their cellular uptake was investigated in several tumor cell lines. In addition, doxorubicin (DOX) was loaded into the targeted and unmodified liposomes, and the cytotoxic effect on the DU-145 cells was evaluated by MTT assay. Results: Liposomes with or without SV119-PEG-DOA both have a mean diameter of approximately 90 nm and a neutral charge. The incorporation of SV119-PEG-DOA significantly increased the cellular uptake of liposomes by the DU-145, PC-3, A549, 201T, and MCF-7 tumor cells, which was shown by fluorescence microscopy and the quantitative measurement of fluorescence intensity. In contrast, the incorporation of SV119 did not increase the uptake of liposomes by the normal BEAS-2B cells. In a time course study, the uptake of SV119 liposomes by DU-145 cells was also significantly higher at each time point compared to the unmodified liposomes. Furthermore, the DOX-loaded SV119 liposomes showed significantly higher cytotoxicity to DU-145 cells compared to the DOX-loaded unmodified liposomes. Conclusion: SV119 liposomes were developed for targeted drug delivery to cancer cells. The targeting efficiency and specificity of SV119 liposomes to cancer cells was

Size-Dependency of the Surface Ligand Density of Liposomes Prepared by Post-insertion.

PubMed

Lee, Shang-Hsuan; Sato, Yusuke; Hyodo, Mamoru; Harashima, Hideyoshi

2017-01-01

In the active targeting of a drug delivery system (DDS), the density of the ligand on the functionalized liposome determines its affinity for binding to the target. To evaluate these densities on the surface of different sized liposomes, 4 liposomes with various diameters (188, 137, 70, 40 nm) were prepared and their surfaces were modified with fluorescently labeled ligand-lipid conjugates by the post-insertion method. Each liposomal mixture was fractionated into a series of fractions using size exclusion chromatography (SEC), and the resulting liposome fractions were precisely analyzed and the surface ligand densities calculated. The data collected using this methodology indicate that the density of the ligand on a particle is greatly dependent on the size of the liposome. This, in turn, indicates that smaller liposomes (75-40 nm) tend to possess higher densities. For developing active targeting systems, size and the density of the ligands are two important and independent factors that can affect the efficiency of a system as it relates to medical use.

Clearance and Biodistribution of Liposomally Encapsulated Nitroxides: A Model for Targeted Delivery of Electron Paramagnetic Resonance Imaging Probes to Tumors

PubMed Central

Burks, Scott R.; Legenzov, Eric A.; Rosen, Gerald M.

2011-01-01

Electron paramagnetic resonance (EPR) imaging using nitroxides as molecular probes is potentially a powerful tool for the detection and physiological characterization of micrometastatic lesions. Encapsulating nitroxides in anti-HER2 immunoliposomes at high concentrations to take advantage of the “self-quenching” phenomenon of nitroxides allows generation of robust EPR signals in HER2-overexpressing breast tumor cells with minimal background from indifferent tissues or circulating liposomes. We investigated the in vivo pharmacological properties of nitroxides encapsulated in sterically stabilized liposomes designed for long circulation times. We show that circulation times of nitroxides can be extended from hours to days; this increases the proportion of liposomes in circulation to enhance tumor targeting. Furthermore, nitroxides encapsulated in sterically stabilized anti-HER2 immunoliposomes can be delivered to HER2-overexpressing tumors at micromolar concentrations, which should be imageable by EPR. Lastly, after in vivo administration, liposomally encapsulated nitroxide signal also appears in the liver, spleen, and kidneys. Although these organs are spatially distinct and would not hinder tumor imaging in our model, understanding nitroxide signal retention in these organs is essential for further improvements in EPR imaging contrast between tumors and other tissues. These results lay the foundation to use liposomally delivered nitroxides and EPR imaging to visualize tumor cells in vivo. PMID:21737567

Hepatocellular carcinoma-targeted effect of configurations and groups of glycyrrhetinic acid by evaluation of its derivative-modified liposomes

PubMed Central

Sun, Yuqi; Dai, Chunmei; Yin, Meilin; Lu, Jinghua; Hu, Haiyang; Chen, Dawei

2018-01-01

Background There are abundant glycyrrhetinic acid (GA) receptors on the cellular membrane of hepatocytes and hepatocellular carcinoma (HCC) cells. The receptor binding effect might be related to the structure of the guiding molecule. GA exists in two stereoisomers with C3-hydroxyl and C11-carbonyl active groups. Purpose The objective of this study was to investigate the relationship between the HCC-targeted effect and the configurations and groups of GA. Methods and results Different GA derivatives (18β-GA, 18α-GA, 3-acetyl-18β-GA [3-Ace-GA] and 11-deoxy-18β-GA [11-Deo-GA]) were used to investigate the targeting effect of GA’s configurations and groups on HCC cells. The EC50 values of competition to binding sites and the ratio of specific binding in HepG2 cells showed that 18β-GA and 3-Ace-GA demonstrated significant competitive effect with fluorescein isothiocyanate (FITC)-labeled GA. Then, the GA derivatives were distearoyl-phosphatidylethanolamine (DSPE)-PEGylated. 18β-GA-, 18α-GA-, 3-Ace-GA-and 11-Deo-GA-modified liposomes were prepared and characterized by size, zeta potential, encapsulation efficiency, loading capacity, leakage and membrane stability. Evaluation on the cellular location in vitro and tumor targeting in vivo was carried out. Compared to common long-circulation liposome (PEG-Lip), more 18β-GA- and 3-Ace-GA-modified liposomes aggregated around HepG2 cells in vitro in short time and transferred into HCC tumors in vivo for a longer time. Conclusion The β-configuration hydrogen atom on C18 position of GA played the most important role on the targeting effect. C11-carbonyl and C3-hydroxy groups of GA have certain and little influence on targeting action to HCC, respectively. In general, GA might be a promising targeting molecule for the research on liver diseases and hepatoma therapy. PMID:29588589

Potentiation of antiproliferative drug activity by lonidamine in hepatocellular carcinoma cells.

PubMed

Ricotti, L; Tesei, A; De Paola, F; Milandri, C; Amadori, D; Frassineti, G L; Ulivi, P; Zoli, W

2003-10-01

The ability of lonidamine (LND), a derivative of indazole-carboxylic acid, to modulate the cytotoxic activity of anticancer drugs was investigated in two human hepatocarcinoma (HCC) cell lines. The cytotoxicity of drugs used singly, in association or in sequence was evaluated using the Sulforhodamine B (SRB) assay. LND did not appreciably potentiate the effect of antitumor drugs when given before or simultaneously, in either cell line. Conversely, a synergistic interaction was observed in both cell lines when LND was given after conventional drugs. LND produced a moderate decrease in S-phase cell fraction and did not induce apoptosis. Conversely, paclitaxel (TAX) induced an important block in G2 and an increase in apoptosis. Following a 48-h TAX wash out, a progressive passage of cells from G2 to M phase was observed with a corresponding increase in apoptotic cells. Post-treatment with LND increased the cytotoxicity of some antitumor drugs, especially TAX, in hepatocarcinoma cells, possibly by preventing, as an energolytic drug, cell damage repair or by producing an additional effect on microtubule stabilization.

Targeted delivery of CRISPR/Cas9 to prostate cancer by modified gRNA using a flexible aptamer-cationic liposome.

PubMed

Zhen, Shuai; Takahashi, Yoichiro; Narita, Shunichi; Yang, Yi-Chen; Li, Xu

2017-02-07

The potent ability of CRISPR/Cas9 system to inhibit the expression of targeted gene is being exploited as a new class of therapeutics for a variety of diseases. However, the efficient and safe delivery of CRISPR/Cas9 into specific cell populations is still the principal challenge in the clinical development of CRISPR/Cas9 therapeutics. In this study, a flexible aptamer-liposome-CRISPR/Cas9 chimera was designed to combine efficient delivery and increased flexibility. Our chimera incorporated an RNA aptamer that specifically binds prostate cancer cells expressing the prostate-specific membrane antigen as a ligand. Cationic liposomes were linked to aptamers by the post-insertion method and were used to deliver therapeutic CRISPR/Cas9 that target the survival gene, polo-like kinase 1, in tumor cells. We demonstrate that the aptamer-liposome-CRISPR/Cas9 chimeras had a significant cell-type binding specificity and a remarkable gene silencing effect in vitro. Furthermore, silencing promoted a conspicuous regression of prostate cancer in vivo. Importantly, the approach described here provides a universal means of cell type-specific CRISPR/Cas9 delivery, which is a critical goal for the widespread therapeutic applicability of CRISPR/Cas9 or other nucleic acid drugs.

Targeted delivery of CRISPR/Cas9 to prostate cancer by modified gRNA using a flexible aptamer-cationic liposome

PubMed Central

Zhen, Shuai; Takahashi, Yoichiro; Narita, Shunichi; Yang, Yi-Chen; Li, Xu

2017-01-01

The potent ability of CRISPR/Cas9 system to inhibit the expression of targeted gene is being exploited as a new class of therapeutics for a variety of diseases. However, the efficient and safe delivery of CRISPR/Cas9 into specific cell populations is still the principal challenge in the clinical development of CRISPR/Cas9 therapeutics. In this study, a flexible aptamer-liposome-CRISPR/Cas9 chimera was designed to combine efficient delivery and increased flexibility. Our chimera incorporated an RNA aptamer that specifically binds prostate cancer cells expressing the prostate-specific membrane antigen as a ligand. Cationic liposomes were linked to aptamers by the post-insertion method and were used to deliver therapeutic CRISPR/Cas9 that target the survival gene, polo-like kinase 1, in tumor cells. We demonstrate that the aptamer-liposome-CRISPR/Cas9 chimeras had a significant cell-type binding specificity and a remarkable gene silencing effect in vitro. Furthermore, silencing promoted a conspicuous regression of prostate cancer in vivo. Importantly, the approach described here provides a universal means of cell type–specific CRISPR/Cas9 delivery, which is a critical goal for the widespread therapeutic applicability of CRISPR/Cas9 or other nucleic acid drugs. PMID:28030843

Dual drug delivery using "smart" liposomes for triggered release of anticancer agents

NASA Astrophysics Data System (ADS)

Jain, Ankit; Gulbake, Arvind; Jain, Ashish; Shilpi, Satish; Hurkat, Pooja; Jain, Sanjay K.

2013-07-01

Ovarian cancer is one of the most fatal gynecologic cancers. In this debut study, dual approach using synergistically active combination of paclitaxel-topotecan (Pac-Top; 20:1, w/w) is investigated with utilization of characteristic features of tumor micro-environment and additionally overexpressed folate receptors (FR-α) to achieve targeting to tumor site. Various liposomes namely liposomes, PEGylated liposomes, and FR-targeted PEGylated liposomes with lipid compositions viz. DPPC:DMPG (85.5:9.5), DPPC:DMPG:mPEG2000-DSPE (85.5:9.5:5), and DPPC:DMPG:mPEG2000-DSPE:DSPE-PEG-folate (85.5:9.5:4.5:0.5), respectively, were developed using thin film casting method. These were nanometric in size around 200 nm. In vitro drug release study showed initial burst release followed by sustained release for more than 72 h at physiological milieu (37 ± 0.5 °C, pH 7.4) while burst release (i.e., more than 90 %) within 5 min at simulated tumor milieu (41 ± 1 °C, pH 4). SRB cytotoxicity assay in OVCAR-3 cell line revealed Pac-Top free (20:1, w/w) to be more toxic (GI50 = 6.5 μg/ml) than positive control (Adriamycin, GI50 = 9.1 μg/ml) and FR-targeted PEGylated liposomes GI50 (14.7 μg/ml). Moreover, florescence microscopy showed the highest cell uptake of FR-targeted PEGylated liposomes so called "smart liposomes" which has not only mediated effective targeting to FR-α but also triggered release of drugs upon hyperthermia.

Surfactant protein-A nanobody-conjugated liposomes loaded with methylprednisolone increase lung-targeting specificity and therapeutic effect for acute lung injury.

PubMed

Li, Nan; Weng, Dong; Wang, Shan-Mei; Zhang, Yuan; Chen, Shan-Shan; Yin, Zhao-Fang; Zhai, Jiali; Scoble, Judy; Williams, Charlotte C; Chen, Tao; Qiu, Hui; Wu, Qin; Zhao, Meng-Meng; Lu, Li-Qin; Mulet, Xavier; Li, Hui-Ping

2017-11-01

The advent of nanomedicine requires novel delivery vehicles to actively target their site of action. Here, we demonstrate the development of lung-targeting drug-loaded liposomes and their efficacy, specificity and safety. Our study focuses on glucocorticoids methylprednisolone (MPS), a commonly used drug to treat lung injuries. The steroidal molecule was loaded into functionalized nano-sterically stabilized unilamellar liposomes (NSSLs). Targeting functionality was performed through conjugation of surfactant protein A (SPANb) nanobodies to form MPS-NSSLs-SPANb. MPS-NSSLs-SPANb exhibited good size distribution, morphology, and encapsulation efficiency. Animal experiments demonstrated the high specificity of MPS-NSSLs-SPANb to the lung. Treatment with MPS-NSSLs-SPANb reduced the levels of TNF-α, IL-8, and TGF-β1 in rat bronchoalveolar lavage fluid and the expression of NK-κB in the lung tissues, thereby alleviating lung injuries and increasing rat survival. The nanobody functionalized nanoparticles demonstrate superior performance to treat lung injury when compared to that of antibody functionalized systems.

Eph A10-modified pH-sensitive liposomes loaded with novel triphenylphosphine-docetaxel conjugate possess hierarchical targetability and sufficient antitumor effect both in vitro and in vivo.

PubMed

Zhang, Jiulong; Yang, Chunrong; Pan, Shuang; Shi, Menghao; Li, Jie; Hu, Haiyang; Qiao, Mingxi; Chen, Dawei; Zhao, Xiuli

2018-11-01

Mitochondrial-targeting therapy was considered to be a promising approach for the efficient treatment of cancer while positive charge induced nonspecific cytotoxicity severely limits its application. To overcome this drawback, a novel mitochondria targeted conjugate triphenylphosphine-docetaxel (TD) has been synthesized successfully and incorporated it into liposomes (EPSLP/TD), which possessed excellent pH-sensitive characteristic, EphA 10 mediated active targetability as well as mitochondria-targeting capability. EPSLP/TD was characterized to have a small particle size, high-encapsulation efficiency and excellent pH-sensitive characteristic. Compared with DTX-loaded liposomes (EPSLP/DTX), EPSLP/TD possessed higher cytotoxicity against MCF-7 cell line. Mitochondrial-targeting assay demonstrated mitochondria-targeting moiety triphenylphosphine (TPP) could efficiently deliver DTX to mitochondria. Western immunoblotting assay indicated that EPSLP/TD could efficiently deliver antitumor drug to mitochondria and induce cell apoptosis via mitochondria-mediated apoptosis pathway. In vivo antitumor study demonstrated EPSLP/TD owed excellent in vivo antitumor activity. Histological assay demonstrated EPSLP/TD showed strongly apoptosis inducing effect, anti-proliferation effect and anti-angiogenesis effect. This work investigated the potential of hierarchical targeting pH-sensitive liposomes is a suitable carrier to activate mitochondria-mediated apoptosis pathway for cancer therapy.

Targeting prostate cancer cells with hybrid elastin-like polypeptide/liposome nanoparticles

PubMed Central

Zhang, Wei; Song, Yunmei; Eldi, Preethi; Guo, Xiuli; Hayball, John D; Garg, Sanjay; Albrecht, Hugo

2018-01-01

Prostate cancer cells frequently overexpress the gastrin-releasing peptide receptor, and various strategies have been applied in preclinical settings to target this receptor for the specific delivery of anticancer compounds. Recently, elastin-like polypeptide (ELP)-based self-assembling micelles with tethered GRP on the surface have been suggested to actively target prostate cancer cells. Poorly soluble chemotherapeutics such as docetaxel (DTX) can be loaded into the hydrophobic cores of ELP micelles, but only limited drug retention times have been achieved. Herein, we report the generation of hybrid ELP/liposome nanoparticles which self-assembled rapidly in response to temperature change, encapsulated DTX at high concentrations with slow release, displayed the GRP ligand on the surface, and specifically bound to GRP receptor expressing PC-3 cells as demonstrated by flow cytometry. This novel type of drug nanocarrier was successfully used to reduce cell viability of prostate cancer cells in vitro through the specific delivery of DTX. PMID:29391790

"Smart" liposomal nanocontainers in biology and medicine.

PubMed

Tarahovsky, Y S

2010-07-01

The perspectives of using liposomes for delivery of drugs to desired parts of the human body have been intensively investigated for more than 30 years. During this time many inventions have been suggested and different kinds of liposomal devices developed, and a number of them have reached the stages of preclinical or clinical trials. The latest techniques can be used to develop biocompatible nano-sized liposomal containers having some abilities of artificial intellect, such as the presence of sensory and responsive units. However, only a few have been clinically approved. Further improvements in this area depend on our knowledge of the interactions of drugs with the lipid bilayer of liposomes. Further studies on liposomal transport through the human body, their targeting of cells requiring therapeutic treatment, and finally, the development of techniques for controlled drug delivery to desired acceptors on cell surfaces or in cytoplasm are still required.

A dual-targeting liposome conjugated with transferrin and arginine-glycine-aspartic acid peptide for glioma-targeting therapy.

PubMed

Qin, Li; Wang, Cheng-Zheng; Fan, Hui-Jie; Zhang, Chong-Jian; Zhang, Heng-Wei; Lv, Min-Hao; Cui, Shu-DE

2014-11-01

The treatment of a brain glioma remains one of the most difficult challenges in oncology. In the present study a delivery system was developed for targeted drug delivery across the blood-brain barrier (BBB) to the brain cancer cells. A cyclic arginine-glycine-aspartic acid (RGD) peptide and transferrin (TF) were utilized as targeting ligands. Cyclic RGD peptides are specific targeting ligands of cancer cells and TFs are ligands that specifically target the BBB and cancer cells. Liposome (LP) was used to conjugate the cyclic RGD and TFs to establish the brain glioma cascade delivery system (RGD/TF-LP). The LPs were prepared by the thin film hydration method and physicochemical characterization was conducted. In vitro cell uptake and three-dimensional tumor spheroid penetration studies demonstrated that the system could target endothelial and tumor cells, as well as penetrate the tumor cells to reach the core of the tumor spheroids. The results of the in vivo imaging further demonstrated that the RGD/TF-LP provided the highest brain distribution. As a result, the paclitaxel-loaded RGD/TF-LP presents the best antiproliferative activity against C6 cells and tumor spheroids. In conclusion, the RGD/TF-LP may precisely target brain glioma, which may be valuable for glioma imaging and therapy.

The energy blockers 3-bromopyruvate and lonidamine: effects on bioenergetics of brain mitochondria.

PubMed

Macchioni, Lara; Davidescu, Magdalena; Roberti, Rita; Corazzi, Lanfranco

2014-10-01

Tumor cells favor abnormal energy production via aerobic glycolysis and show resistance to apoptosis, suggesting the involvement of mitochondrial dysfunction. The differences between normal and cancer cells in their energy metabolism provide a biochemical basis for developing new therapeutic strategies. The energy blocker 3-bromopyruvate (3BP) can eradicate liver cancer in animals without associated toxicity, and is a potent anticancer towards glioblastoma cells. Since mitochondria are 3BP targets, in this work the effects of 3BP on the bioenergetics of normal rat brain mitochondria were investigated in vitro, in comparison with the anticancer agent lonidamine (LND). Whereas LND impaired oxygen consumption dependent on any complex of the respiratory chain, 3BP was inhibitory to malate/pyruvate and succinate (Complexes I and II), but preserved respiration from glycerol-3-phosphate and ascorbate (Complex IV). Accordingly, although electron flow along the respiratory chain and ATP levels were decreased by 3BP in malate/pyruvate- and succinate-fed mitochondria, they were not significantly influenced from glycerol-3-phosphate- or ascorbate-fed mitochondria. LND produced a decrease in electron flow from all substrates tested. No ROS were produced from any substrate, with the exception of 3BP-induced H(2)O(2) release from succinate, which suggests an antimycin-like action of 3BP as an inhibitor of Complex III. We can conclude that 3BP does not abolish completely respiration and ATP synthesis in brain mitochondria, and has a limited effect on ROS production, confirming that this drug may have limited harmful effects on normal cells.

Targeting of folate-conjugated liposomes with co-entrapped drugs to prostate cancer cells via prostate-specific membrane antigen (PSMA).

PubMed

Patil, Yogita; Shmeeda, Hilary; Amitay, Yasmine; Ohana, Patricia; Kumar, Saran; Gabizon, Alberto

2018-04-19

Folate-targeted liposomes (FTL) were tested as drug delivery vehicles to PSMA-positive cancer cells. We used FL with co-entrapped mitomycin C lipophilic prodrug (MLP) and doxorubicin (DOX), and the LNCaP prostate cancer cell line which expresses PSMA but is negative for folate receptor. A major increase in cell drug levels was observed when LNCaP cells were incubated with FTL as compared to non-targeted liposomes (NTL). MLP was activated to mitomycin C, and intracellular and nuclear fluorescence of DOX was detected, indicating FTL processing and drug bioavailability. PMPA (2-(phosphonomethyl)-pentanedioic acid), a specific inhibitor of PSMA, blocked the uptake of FTL into LNCaP cells, but did not affect the uptake of FTL into PSMA-deficient and folate receptor-positive KB cells. The cytotoxic activity of drug-loaded FTL was found significantly enhanced when compared to NTL in LNCaP cells. FTL may provide a new tool for targeted therapy of cancers that over-express the PSMA receptor. Copyright © 2018. Published by Elsevier Inc.

Vincristine-sulphate-loaded liposome-templated calcium phosphate nanoshell as potential tumor-targeting delivery system.

PubMed

Thakkar, Hetal Paresh; Baser, Amit Kumar; Parmar, Mayur Prakashbhai; Patel, Ketul Harshadbhai; Ramachandra Murthy, Rayasa

2012-06-01

Vincristine-sulfate-loaded liposomes were prepared with an aim to improve stability, reduce drug leakage during systemic circulation, and increase intracellular uptake. Liposomes were prepared by the thin-film hydration method, followed by coating with calcium phosphate, using the sequential addition approach. Prepared formulations were characterized for size, zeta potential, drug-entrapment efficiency, morphology by transmission electron microscopy (TEM), in vitro drug-release profile, and in vitro cell cytotoxicity study. Effect of formulation variables, such as drug:lipid ratio as well as nature and volume of hydration media, were found to affect drug entrapment, and the concentration of calcium chloride in coating was found to affect size and coating efficiency. Size, zeta potential, and TEM images confirmed that the liposomes were effectively coated with calcium phosphate. The calcium phosphate nanoshell exhibited pH-dependent drug release, showing significantly lower release at pH 7.4, compared to the release at pH 4.5, which is the pH of the tumor interstitium. The in vitro cytotoxicity study done on the lung cancer cell line indicated that coated liposomes are more cytotoxic than plain liposomes and drug solution, indicating their potential for intracellular drug delivery. The cell-uptake study done on the lung cancer cell line indicated that calcium-phosphate-coated liposomes show higher cell uptake than uncoated liposomes.

pH-Sensitive Liposomes: Possible Clinical Implications

NASA Astrophysics Data System (ADS)

Yatvin, M. B.; Kreutz, W.; Horwitz, B. A.; Shinitzky, M.

1980-12-01

When pH-sensitive molecules are incorporated into liposomes, drugs can be specifically released from these vesicles by a change of pH in the ambient serum. Liposomes containing the pH-sensitive lipid palmitoyl homocysteine (PHC) were constructed so that the greatest pH differential (6.0 to 7.4) of drug release was obtained near physiological temperature. Such liposomes could be useful clinically if they enable drugs to be targeted to areas of the body in which pH is less than physiological, such as primary tumors and metastases or sites of inflammation and infection.

Aptamer-based liposomes improve specific drug loading and release.

PubMed

Plourde, Kevin; Derbali, Rabeb Mouna; Desrosiers, Arnaud; Dubath, Céline; Vallée-Bélisle, Alexis; Leblond, Jeanne

2017-04-10

Aptamer technology has shown much promise in cancer therapeutics for its targeting abilities. However, its potential to improve drug loading and release from nanocarriers has not been thoroughly explored. In this study, we employed drug-binding aptamers to actively load drugs into liposomes. We designed a series of DNA aptamer sequences specific to doxorubicin, displaying multiple binding sites and various binding affinities. The binding ability of aptamers was preserved when incorporated into cationic liposomes, binding up to 15equivalents of doxorubicin per aptamer, therefore drawing the drug into liposomes. Optimization of the charge and drug/aptamer ratios resulted in ≥80% encapsulation efficiency of doxorubicin, ten times higher than classical passively-encapsulating liposomal formulations and similar to a pH-gradient active loading strategy. In addition, kinetic release profiles and cytotoxicity assay on HeLa cells demonstrated that the release and therapeutic efficacy of liposomal doxorubicin could be controlled by the aptamer's structure. Our results suggest that the aptamer exhibiting a specific intermediate affinity is the best suited to achieve high drug loading while maintaining efficient drug release and therapeutic activity. This strategy was successfully applied to tobramycin, a hydrophilic drug suffering from low encapsulation into liposomes, where its loading was improved six-fold using aptamers. Overall, we demonstrate that aptamers could act, in addition to their targeting properties, as multifunctional excipients for liposomal formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermo-sensitive liposomes loaded with doxorubicin and lysine modified single-walled carbon nanotubes as tumor-targeting drug delivery system.

PubMed

Zhu, Xiali; Xie, Yingxia; Zhang, Yingjie; Huang, Heqing; Huang, Shengnan; Hou, Lin; Zhang, Huijuan; Li, Zhi; Shi, Jinjin; Zhang, Zhenzhong

2014-11-01

This report focuses on the thermo-sensitive liposomes loaded with doxorubicin and lysine-modified single-walled carbon nanotube drug delivery system, which was designed to enhance the anti-tumor effect and reduce the side effects of doxorubicin. Doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes was prepared by reverse-phase evaporation method, the mean particle size was 232.0 ± 5.6 nm, and drug entrapment efficiency was 86.5 ± 3.7%. The drug release test showed that doxorubicin released more quickly at 42℃ than at 37℃. Compared with free doxorubicin, doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes could efficiently cross the cell membranes and afford higher anti-tumor efficacy on the human hepatic carcinoma cell line (SMMC-7721) cells in vitro. For in vivo experiments, the relative tumor volumes of the sarcomaia 180-bearing mice in thermo-sensitive liposomes group and doxorubicin group were significantly smaller than those of N.S. group. Meanwhile, the combination of near-infrared laser irradiation at 808 nm significantly enhanced the tumor growth inhibition both on SMMC-7721 cells and the sarcomaia 180-bearing mice. The quality of life such as body weight, mental state, food and water intake of sarcomaia 180 tumor-bearing mice treated with doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes were much higher than those treated with doxorubicin. In conclusion, doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes combined with near-infrared laser irradiation at 808 nm may potentially provide viable clinical strategies for targeting delivery of anti-cancer drugs. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Phospholipid liposomes functionalized by protein

NASA Astrophysics Data System (ADS)

Glukhova, O. E.; Savostyanov, G. V.; Grishina, O. A.

2015-03-01

Finding new ways to deliver neurotrophic drugs to the brain in newborns is one of the contemporary problems of medicine and pharmaceutical industry. Modern researches in this field indicate the promising prospects of supramolecular transport systems for targeted drug delivery to the brain which can overcome the blood-brain barrier (BBB). Thus, the solution of this problem is actual not only for medicine, but also for society as a whole because it determines the health of future generations. Phospholipid liposomes due to combination of lipo- and hydrophilic properties are considered as the main future objects in medicine for drug delivery through the BBB as well as increasing their bioavailability and toxicity. Liposomes functionalized by various proteins were used as transport systems for ease of liposomes use. Designing of modification oligosaccharide of liposomes surface is promising in the last decade because it enables the delivery of liposomes to specific receptor of human cells by selecting ligand and it is widely used in pharmacology for the treatment of several diseases. The purpose of this work is creation of a coarse-grained model of bilayer of phospholipid liposomes, functionalized by specific to the structural elements of the BBB proteins, as well as prediction of the most favorable orientation and position of the molecules in the generated complex by methods of molecular docking for the formation of the structure. Investigation of activity of the ligand molecule to protein receptor of human cells by the methods of molecular dynamics was carried out.

Characterization of CD44-Mediated Cancer Cell Uptake and Intracellular Distribution of Hyaluronan-Grafted Liposomes

PubMed Central

Qhattal, Hussaini Syed Sha; Liu, Xinli

2011-01-01

Hyaluronan (HA) is a biocompatible and biodegradable linear polysaccharide which is of interest for tumor targeting through cell surface CD44 receptors. HA binds with high affinity to CD44 receptors, which are overexpressed in many tumors and involved in cancer metastasis. In the present study, we investigated the impact of HA molecular weight (MW), grafting density, and CD44 receptor density on endocytosis of HA-grafted liposomes (HA-liposomes) by cancer cells. Additionally, the intracellular localization of the HA-liposomes was determined. HAs of different MWs (5-8, 10-12, 175-350, and 1600 kDa) were conjugated to liposomes with varying degrees of grafting density. HA surface density was quantified using the hexadecyltrimethylammonium bromide turbidimetric method. Cellular uptake and subcellular localization of HA-liposomes were evaluated by flow cytometry and fluorescence microscopy. Mean particle sizes of HA-liposomes ranged from 120 to 180 nm and increased with the bigger size of HA. HA-liposome uptake correlated with HA MW (5-8 < 10-12 < 175-350 kDa), grafting density, and CD44 receptor density and exceeded that obtained with unconjugated plain liposomes. HA-liposomes were taken up into cells via lipid raft-mediated endocytosis, which is both energy- and cholesterol-dependent. Once within cells, HA-liposomes localized primarily to endosomes and lysosomes. The results demonstrate that cellular targeting efficiency of HA-liposomes depends strongly upon HA MW, grafting density, and cell surface receptor CD44 density. The results support a role of HA-liposomes for targeted drug delivery. PMID:21696190

From conventional to stealth liposomes: a new frontier in cancer chemotherapy.

PubMed

Cattel, Luigi; Ceruti, Maurizio; Dosio, Franco

2003-01-01

Many attempts have been made to achieve good selectivity to targeted tumor cells by preparing specialized carrier agents that are therapeutically profitable for anticancer therapy. Among these, liposomes are the most studied colloidal particles thus far applied in medicine and in particular in antitumor therapy. Although they were first described in the 1960s, only at the beginning of 1990s did the first therapeutic liposomes appear on the market. The first-generation liposomes (conventional liposomes) comprised a liposome-containing amphotericin B, Ambisome (Nexstar, Boulder, CO, USA), used as an antifungal drug, and Myocet (Elan Pharma Int, Princeton, NJ, USA), a doxorubicin-containing liposome, used in clinical trials to treat metastatic breast cancer. The second-generation liposomes ("pure lipid approach") were long-circulating liposomes, such as Daunoxome, a daunorubicin-containing liposome approved in the US and Europe to treat AIDS-related Kaposi's sarcoma. The third-generation liposomes were surface-modified liposomes with gangliosides or sialic acid, which can evade the immune system responsible for removing liposomes from circulation. The fourth-generation liposomes, pegylated liposomal doxorubicin, were called "stealth liposomes" because of their ability to evade interception by the immune system, in the same way as the stealth bomber was able to evade radar. Actually, the only stealth liposome on the market is Caelyx/Doxil (Schering-Plough, Madison NJ, USA), used to cure AIDS-related Kaposi's sarcoma, resistant ovarian cancer and metastatic breast cancer. Pegylated liposomal doxorubicin is characterized by a very long-circulation half-life, favorable pharmacokinetic behavior and specific accumulation in tumor tissues. These features account for the much lower toxicity shown by Caelyx in comparison to free doxorubicin, in terms of cardiotoxicity, vesicant effects, nausea, vomiting and alopecia. Pegylated liposomal doxorubicin also appeared to be less

Stealth liposomes: review of the basic science, rationale, and clinical applications, existing and potential

PubMed Central

Immordino, Maria Laura; Dosio, Franco; Cattel, Luigi

2006-01-01

Among several promising new drug-delivery systems, liposomes represent an advanced technology to deliver active molecules to the site of action, and at present several formulations are in clinical use. Research on liposome technology has progressed from conventional vesicles (“first-generation liposomes”) to “second-generation liposomes”, in which long-circulating liposomes are obtained by modulating the lipid composition, size, and charge of the vesicle. Liposomes with modified surfaces have also been developed using several molecules, such as glycolipids or sialic acid. A significant step in the development of long-circulating liposomes came with inclusion of the synthetic polymer poly-(ethylene glycol) (PEG) in liposome composition. The presence of PEG on the surface of the liposomal carrier has been shown to extend blood-circulation time while reducing mononuclear phagocyte system uptake (stealth liposomes). This technology has resulted in a large number of liposome formulations encapsulating active molecules, with high target efficiency and activity. Further, by synthetic modification of the terminal PEG molecule, stealth liposomes can be actively targeted with monoclonal antibodies or ligands. This review focuses on stealth technology and summarizes pre-clinical and clinical data relating to the principal liposome formulations; it also discusses emerging trends of this promising technology. PMID:17717971

Stimulus-responsive liposomes as smart nanoplatforms for drug delivery applications.

PubMed

Zangabad, Parham Sahandi; Mirkiani, Soroush; Shahsavari, Shayan; Masoudi, Behrad; Masroor, Maryam; Hamed, Hamid; Jafari, Zahra; Taghipour, Yasamin Davatgaran; Hashemi, Hura; Karimi, Mahdi; Hamblin, Michael R

2018-02-01

Liposomes are known to be promising nanoparticles (NPs) for drug delivery applications. Among different types of self-assembled NPs, liposomes stand out for their non-toxic nature, and their possession of dual hydrophilic-hydrophobic domains. Advantages of liposomes include the ability to solubilize hydrophobic drugs, the ability to incorporate different hydrophilic and lipophilic drugs at the same time, lessening the exposure of host organs to potentially toxic drugs and allowing modification of the surface by a variety of different chemical groups. This modification of the surface, or of the individual constituents, may be used to achieve two important goals. Firstly, ligands for active targeting can be attached that are recognized by cognate receptors over-expressed on the target cells of tissues. Secondly, modification can be used to impart a stimulus-responsive or "smart" character to the liposomes, whereby the cargo is released on demand only when certain internal stimuli (pH, reducing agents, specific enzymes) or external stimuli (light, magnetic field or ultrasound) are present. Here, we review the field of smart liposomes for drug delivery applications.

Light induced cytosolic drug delivery from liposomes with gold nanoparticles.

PubMed

Lajunen, Tatu; Viitala, Lauri; Kontturi, Leena-Stiina; Laaksonen, Timo; Liang, Huamin; Vuorimaa-Laukkanen, Elina; Viitala, Tapani; Le Guével, Xavier; Yliperttula, Marjo; Murtomäki, Lasse; Urtti, Arto

2015-04-10

Externally triggered drug release at defined targets allows site- and time-controlled drug treatment regimens. We have developed liposomal drug carriers with encapsulated gold nanoparticles for triggered drug release. Light energy is converted to heat in the gold nanoparticles and released to the lipid bilayers. Localized temperature increase renders liposomal bilayers to be leaky and triggers drug release. The aim of this study was to develop a drug releasing system capable of releasing its cargo to cell cytosol upon triggering with visible and near infrared light signals. The liposomes were formulated using either heat-sensitive or heat- and pH-sensitive lipid compositions with star or rod shaped gold nanoparticles. Encapsulated fluorescent probe, calcein, was released from the liposomes after exposure to the light. In addition, the pH-sensitive formulations showed a faster drug release in acidic conditions than in neutral conditions. The liposomes were internalized into human retinal pigment epithelial cells (ARPE-19) and human umbilical vein endothelial cells (HUVECs) and did not show any cellular toxicity. The light induced cytosolic delivery of calcein from the gold nanoparticle containing liposomes was shown, whereas no cytosolic release was seen without light induction or without gold nanoparticles in the liposomes. The light activated liposome formulations showed a controlled content release to the cellular cytosol at a specific location and time. Triggering with visual and near infrared light allows good tissue penetration and safety, and the pH-sensitive liposomes may enable selective drug release in the intracellular acidic compartments (endosomes, lysosomes). Thus, light activated liposomes with gold nanoparticles are an attractive option for time- and site-specific drug delivery into the target cells. Copyright © 2015 Elsevier B.V. All rights reserved.

A review of mechanistic insight and application of pH-sensitive liposomes in drug delivery.

PubMed

Paliwal, Shivani Rai; Paliwal, Rishi; Vyas, Suresh P

2015-05-01

The pH-sensitive liposomes have been extensively used as an alternative to conventional liposomes in effective intracellular delivery of therapeutics/antigen/DNA/diagnostics to various compartments of the target cell. Such liposomes are destabilized under acidic conditions of the endocytotic pathway as they usually contain pH-sensitive lipid components. Therefore, the encapsulated content is delivered into the intracellular bio-environment through destabilization or its fusion with the endosomal membrane. The therapeutic efficacy of pH-sensitive liposomes enables them as biomaterial with commercial utility especially in cancer treatment. In addition, targeting ligands including antibodies can be anchored on the surface of pH-sensitive liposomes to target specific cell surface receptors/antigen present on tumor cells. These vesicles have also been widely explored for antigen delivery and serve as immunological adjuvant to enhance the immune response to antigens. The present review deals with recent research updates on application of pH-sensitive liposomes in chemotherapy/diagnostics/antigen/gene delivery etc.

Liposomal nanocarriers for tumor imaging.

PubMed

Erdogan, Suna

2009-04-01

Currently used imaging modalities such as scintigraphy, computed tomography, magnetic resonance imaging and ultrasonography require the sufficient intensity of a corresponding signal from an area of interest to differentiate this area from the surrounding tissues. Targeting of various reporter moieties directly to the specific organs, tissues or tumors provide the highest dose of drug directly where it is needed. Many different types of nanoparticles are currently being studied for applications in nanomedicine. Among particulate drug carriers, liposomes are one of the most extensively studied and possess the most suitable characteristics for encapsulation of many drugs, genes, and diagnostic (imaging) agents. Among the many potential targets for such nanocarriers, tumors have been most often investigated. This review attempts to summarize the currently available information regarding liposomal nanocarriers for cancer imaging.

Recent Developments of Liposomes as Nanocarriers for Theranostic Applications

PubMed Central

Xing, Hang; Hwang, Kevin; Lu, Yi

2016-01-01

Liposomes are nanocarriers comprised of lipid bilayers encapsulating an aqueous core. The ability of liposomes to encapsulate a wide variety of diagnostic and therapeutic agents has led to significant interest in utilizing liposomes as nanocarriers for theranostic applications. In this review, we highlight recent progress in developing liposomes as nanocarriers for a) diagnostic applications to detect proteins, DNA, and small molecule targets using fluorescence, magnetic resonance, ultrasound, and nuclear imaging; b) therapeutic applications based on small molecule-based therapy, gene therapy and immunotherapy; and c) theranostic applications for simultaneous detection and treatment of heavy metal toxicity and cancers. In addition, we summarize recent studies towards understanding of interactions between liposomes and biological components. Finally, perspectives on future directions in advancing the field for clinical translations are also discussed. PMID:27375783

Designing liposomal adjuvants for the next generation of vaccines.

PubMed

Perrie, Yvonne; Crofts, Fraser; Devitt, Andrew; Griffiths, Helen R; Kastner, Elisabeth; Nadella, Vinod

2016-04-01

Liposomes not only offer the ability to enhance drug delivery, but can effectively act as vaccine delivery systems and adjuvants. Their flexibility in size, charge, bilayer rigidity and composition allow for targeted antigen delivery via a range of administration routes. In the development of liposomal adjuvants, the type of immune response promoted has been linked to their physico-chemical characteristics, with the size and charge of the liposomal particles impacting on liposome biodistribution, exposure in the lymph nodes and recruitment of the innate immune system. The addition of immunostimulatory agents can further potentiate their immunogenic properties. Here, we outline the attributes that should be considered in the design and manufacture of liposomal adjuvants for the delivery of sub-unit and nucleic acid based vaccines. Copyright © 2015 Elsevier B.V. All rights reserved.

Dual-Energy CT Imaging of Tumor Liposome Delivery After Gold Nanoparticle-Augmented Radiation Therapy

PubMed Central

Ashton, Jeffrey R.; Castle, Katherine D.; Qi, Yi; Kirsch, David G.; West, Jennifer L.; Badea, Cristian T.

2018-01-01

Gold nanoparticles (AuNPs) are emerging as promising agents for both cancer therapy and computed tomography (CT) imaging. AuNPs absorb x-rays and subsequently release low-energy, short-range photoelectrons during external beam radiation therapy (RT), increasing the local radiation dose. When AuNPs are near tumor vasculature, the additional radiation dose can lead to increased vascular permeability. This work focuses on understanding how tumor vascular permeability is influenced by AuNP-augmented RT, and how this effect can be used to improve the delivery of nanoparticle chemotherapeutics. Methods: Dual-energy CT was used to quantify the accumulation of both liposomal iodine and AuNPs in tumors following AuNP-augmented RT in a mouse model of primary soft tissue sarcoma. Mice were injected with non-targeted AuNPs, RGD-functionalized AuNPs (vascular targeting), or no AuNPs, after which they were treated with varying doses of RT. The mice were injected with either liposomal iodine (for the imaging study) or liposomal doxorubicin (for the treatment study) 24 hours after RT. Increased tumor liposome accumulation was assessed by dual-energy CT (iodine) or by tracking tumor treatment response (doxorubicin). Results: A significant increase in vascular permeability was observed for all groups after 20 Gy RT, for the targeted and non-targeted AuNP groups after 10 Gy RT, and for the vascular-targeted AuNP group after 5 Gy RT. Combining targeted AuNPs with 5 Gy RT and liposomal doxorubicin led to a significant tumor growth delay (tumor doubling time ~ 8 days) compared to AuNP-augmented RT or chemotherapy alone (tumor doubling time ~3-4 days). Conclusions: The addition of vascular-targeted AuNPs significantly improved the treatment effect of liposomal doxorubicin after RT, consistent with the increased liposome accumulation observed in tumors in the imaging study. Using this approach with a liposomal drug delivery system can increase specific tumor delivery of chemotherapeutics

Calcium-Responsive Liposomes via a Synthetic Lipid Switch.

PubMed

Lou, Jinchao; Carr, Adam J; Watson, Alexa J; Mattern-Schain, Samuel I; Best, Michael D

2018-03-07

Liposomal drug delivery would benefit from enhanced control over content release. Here, we report a novel avenue for triggering release driven by chemical composition using liposomes sensitized to calcium-a target chosen due to its key roles in biology and disease. To demonstrate this principle, we synthesized calcium-responsive lipid switch 1, designed to undergo conformational changes upon calcium binding. The conformational change perturbs membrane integrity, thereby promoting cargo release. This was shown through fluorescence-based release assays via dose-dependent response depending on the percentage of 1 in liposomes, with minimal background leakage in controls. DLS experiments indicated dramatic changes in particle size upon treatment of liposomes containing 1 with calcium. In a comparison of ten naturally occurring metal cations, calcium provided the greatest release. Finally, STEM images showed significant changes in liposome morphology upon treatment of liposomes containing 1 with calcium. These results showcase lipid switches driven by molecular recognition principles as an exciting avenue for controlling membrane properties. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

pHLIP®-Mediated Delivery of PEGylated Liposomes to Cancer Cells

PubMed Central

Yao, Lan; Daniels, Jennifer; Wijesinghe, Dayanjali; Andreev, Oleg A.; Reshetnyak, Yana K.

2013-01-01

We develop a method for pH-dependent fusion between liposomes and cellular membranes using pHLIP® (pH Low Insertion Peptide), which inserts into lipid bilayer of membrane only at low pH. Previously we establish the molecular mechanism of peptide action and show that pHLIP can target acidic diseased tissue. Here we investigate how coating of PEGylated liposomes with pHLIP might affect liposomal uptake by cells. The presence of pHLIP on the surface of PEGylated-liposomes enhanced membrane fusion and lipid exchange in a pH dependent fashion, leading to increase of cellular uptake and payload release, and inhibition of cell proliferation by liposomes containing ceramide. A novel type of pH-sensitive, “fusogenic” pHLIP-liposomes was developed, which could be used to selectively deliver various diagnostic and therapeutic agents to acidic diseased cells. PMID:23416366

Surface functionalization of liposomes with proteins and carbohydrates for use in anti-cancer applications

NASA Astrophysics Data System (ADS)

Platt, Virginia M.

Liposomes can be used to exploit the altered biology of cancer thereby increasing delivery of liposome-associated anti-cancer drugs. In this dissertation, I explore methods that utilize the unique cancer expression of the polymeric glycosaminoglycan hyaluronan (HA) and the HA receptor CD44 to target liposomes to tumors, using liposomes functionalized with proteins or oligosaccharides on their surface. To make it easier to prepare protein-functionalized liposomes, a non-covalent protein/liposome association method based upon metal chelation/his 6 interaction was devised and characterized. I evaluated non-covalent attachment of the prodrug converting enzyme yeast cytosine deaminase, the far-red fluorescent protein mKate, two antigens ovalbumin and the membrane proximal region of an HIV GAG and hyaluronidase, a HA-degrading enzyme. In Chapter 2, I describe the synthesis of hyaluronan-oligosaccharide (HA-O) lipid conjugates and their incorporation into liposomes to target CD44-overexpressing cancer cells. HA-O ligands of defined-length, up to 10 monosaccharides, were attached to lipids via various linkers by reductive amination. The HA-lipids were easily incorporated into liposomes but did not mediate binding of liposomes to CD44 overexpressing cells. In Chapter 3, I evaluate the capacity of tris-NTA-Ni-lipids incorporated within a liposome bilayer to associate with his6-tagged proteins. Tris-NTA-lipids of differing structures and avidities were used to associate yeast cytosine deaminase and mKate to the surface of liposomes. Two tris-NTA-lipids and a mono-NTA lipid associated his-tagged proteins to a 1:1 molar ratio in solution. The proteins remained active while associated with the liposome surface. When challenged in vitro with fetal calf serum, tris-NTA-containing liposomes retained his-tagged proteins longer than mono-NTA. However, the tris-NTA/his6 interaction was found to be in a dynamic state; free yeast cytosine deaminase rapidly competed with pre-bound m

Release of Liposomal Contents by Cell-Secreted Matrix Metalloproteinase-9

PubMed Central

Banerjee, Jayati; Hanson, Andrea J.; Gadam, Bhushan; Elegbede, Adekunle I.; Tobwala, Shakila; Ganguly, Bratati; Wagh, Anil; Muhonen, Wallace W.; Law, Benedict; Shabb, John B.; Srivastava, D. K.; Mallik, Sanku

2011-01-01

Liposomes have been widely used as a drug delivery vehicle and currently, more than 10 liposomal formulations are approved by the Food and Drug Administration for clinical use. However, upon targeting, the release of the liposome-encapsulated contents is usually slow. We have recently demonstrated that contents from appropriately-formulated liposomes can be rapidly released by the cancer-associated enzyme matrix metalloproteinase-9 (MMP-9). Herein, we report our detailed studies to optimize the liposomal formulations. By properly selecting the lipopeptide, the major lipid component and their relative amounts, we demonstrate that the contents are rapidly released in the presence of cancer-associated levels of recombinant human MMP-9. We observed that the degree of lipid mismatch between the lipopepides and the major lipid component profoundly affects the release profiles from the liposomes. By utilizing the optimized liposomal formulations, we also demonstrate that cancer cells (HT-29) which secrete low levels of MMP-9 failed to release significant amount of the liposomal contents. Metastatic cancer cells (MCF7) secreting high levels of the enzyme rapidly release the encapsulated contents from the liposomes. PMID:19601658

Human rhinovirus-induced inflammatory responses are inhibited by phosphatidylserine containing liposomes.

PubMed

Stokes, C A; Kaur, R; Edwards, M R; Mondhe, M; Robinson, D; Prestwich, E C; Hume, R D; Marshall, C A; Perrie, Y; O'Donnell, V B; Harwood, J L; Sabroe, I; Parker, L C

2016-09-01

Human rhinovirus (HRV) infections are major contributors to the healthcare burden associated with acute exacerbations of chronic airway disease, such as chronic obstructive pulmonary disease and asthma. Cellular responses to HRV are mediated through pattern recognition receptors that may in part signal from membrane microdomains. We previously found Toll-like receptor signaling is reduced, by targeting membrane microdomains with a specific liposomal phosphatidylserine species, 1-stearoyl-2-arachidonoyl-sn-glycero-3-phospho-L-serine (SAPS). Here we explored the ability of this approach to target a clinically important pathogen. We determined the biochemical and biophysical properties and stability of SAPS liposomes and studied their ability to modulate rhinovirus-induced inflammation, measured by cytokine production, and rhinovirus replication in both immortalized and normal primary bronchial epithelial cells. SAPS liposomes rapidly partitioned throughout the plasma membrane and internal cellular membranes of epithelial cells. Uptake of liposomes did not cause cell death, but was associated with markedly reduced inflammatory responses to rhinovirus, at the expense of only modest non-significant increases in viral replication, and without impairment of interferon receptor signaling. Thus using liposomes of phosphatidylserine to target membrane microdomains is a feasible mechanism for modulating rhinovirus-induced signaling, and potentially a prototypic new therapy for viral-mediated inflammation.

Comparative dosimetric evaluation of nanotargeted (188)Re-(DXR)-liposome for internal radiotherapy.

PubMed

Chang, Chih-Hsien; Stabin, Michael G; Chang, Ya-Jen; Chen, Liang-Cheng; Chen, Min-Hua; Chang, Tsui-Jung; Lee, Te-Wei; Ting, Gann

2008-12-01

A dosimetric analysis was performed to evaluate nanoliposomes as carriers of radionuclides ((188)Re-liposomes) and radiochemotherapeutic drugs [(188)Re-doxorubicin (DXR)-liposomes] in internal radiotherapy for colon carcinoma, as evaluated in mice. Pharmacokinetic data for (188)Re-N, N-bis (2-mercaptoethyl)-N',N'-diethylethylenediamine (BMEDA), (188)Re-liposome, and (188)Re-DXR-liposome were obtained for the estimation of absorbed doses in tumors and normal organs. Two colon carcinoma mouse models were employed: subcutaneous growing solid tumor and malignant ascites pervading tumor models. Radiation-dose estimates for normal tissues and tumors were calculated by using the OLINDA/EXM program. An evaluation of a recommended maximum administered activity (MAA) for the nanotargeted drugs was also made. Mean absorbed doses derived from (188)Re-liposome and (188)Re-DXR-liposome in normal tissues were generally similar to those from (188)Re-BMEDA in intraperitoneal and intravenous administration. Tissue-absorbed dose in the liver was 0.24-0.40 and 0.17-0.26 (mGy/MBq) and in red marrow was 0.033-0.050 and 0.038-0.046 (mGy/MBq), respectively, for (188)Re-liposome and (188)Re-DXR-liposome. Tumor-absorbed doses for the nanotargeted (188)Re-liposome and (188)Re-DXR-liposome were higher than those of (188)Re-BMEDA for both routes of administration (4-26-fold). Dose to red marrow defined the recommended MAA. Our results suggest that radionuclide and chemoradiotherapeutic passive targeting delivery, using nanoliposomes as the carrier, is feasible and promising in systemic-targeted radionuclide therapy.

Syntheses and characterization of liposome-incorporated adamantyl aminoguanidines.

PubMed

Šekutor, Marina; Štimac, Adela; Mlinarić-Majerski, Kata; Frkanec, Ruža

2014-08-21

A series of mono and bis-aminoguanidinium adamantane derivatives has been synthesized and incorporated into liposomes. They combine two biomedically significant molecules, the adamantane moiety and the guanidinium group. The adamantane moiety possesses the membrane compatible features while the cationic guanidinium subunit was recognized as a favourable structural feature for binding to complementary molecules comprising phosphate groups. The liposome formulations of adamantyl aminoguanidines were characterized and it was shown that the entrapment efficiency of the examined compounds is significant. In addition, it was demonstrated that liposomes with incorporated adamantyl aminoguanidines effectively recognized the complementary liposomes via the phosphate group. These results indicate that adamantane derivatives bearing guanidinium groups might be versatile tools for biomedical application, from studies of molecular recognition processes to usage in drug formulation and cell targeting.

Multi-functional liposomes showing radiofrequency-triggered release and magnetic resonance imaging for tumor multi-mechanism therapy.

PubMed

Du, Bin; Han, Shuping; Li, Hongyan; Zhao, Feifei; Su, Xiangjie; Cao, Xiaohui; Zhang, Zhenzhong

2015-03-12

Recently, nanoplatforms with multiple functions, such as tumor-targeting drug carriers, MRI, optical imaging, thermal therapy etc., have become popular in the field of cancer research. The present study reports a novel multi-functional liposome for cancer theranostics. A dual targeted drug delivery with radiofrequency-triggered drug release and imaging based on the magnetic field influence was used advantageously for tumor multi-mechanism therapy. In this system, the surface of fullerene (C60) was decorated with iron oxide nanoparticles, and PEGylation formed a hybrid nanosystem (C60-Fe3O4-PEG2000). Thermosensitive liposomes (dipalmitoylphosphatidylcholine, DPPC) with DSPE-PEG2000-folate wrapped up the hybrid nanosystem and docetaxel (DTX), which were designed to combine features of biological and physical (magnetic) drug targeting for fullerene radiofrequency-triggered drug release. The magnetic liposomes not only served as powerful tumor diagnostic magnetic resonance imaging (MRI) contrast agents, but also as powerful agents for photothermal ablation of tumors. Furthermore, a remarkable thermal therapy combined chemotherapy multi-functional liposome nanoplatform converted radiofrequency energy into thermal energy to release drugs from thermosensitive liposomes, which was also observed during both in vitro and in vivo treatment. The multi-functional liposomes also could selectively kill cancer cells in highly localized regions via their excellent active tumor targeting and magnetic targeted abilities.

Experimental anticancer therapy with vascular-disruptive peptide and liposome-entrapped chemotherapeutic agent.

PubMed

Sochanik, Aleksander; Mitrus, Iwona; Smolarczyk, Ryszard; Cichoń, Tomasz; Snietura, Mirosław; Czaja, Maria; Szala, Stanisław

2010-06-01

Vasculature is essential for the sustained growth of solid tumors and metastases. Tumor cells surviving vascular-disruptive therapeutic intervention (especially those present at the tumor rim) can contribute to tumor regrowth. The aim was to strengthen, by carrier-mediated delivery of a chemotherapeutic, the curative effects of a bifunctional anti-vascular oligopeptide capable of inducing vascular shutdown and tumor shrinkage. For the in vitro experiments and animal therapy, ACDCRGDCFC-GG-(D)(KLAKLAK)(2) peptide (900 microM in D-PBSA, i.e. Dulbecco's PBS without Ca(2+) and Mg(2+)) and size-calibrated, passively or actively targeted liposomes based on distearoylphosphatidylcholine, cholesterol, and N-carbamoyl-methoxypolyethyleneglycol coupled to distearoylphosphatidylethanolamine (PEG-DSPE) and containing gradient-entrapped doxorubicin were used. The KB (human nasopharyngeal carcinoma) cell line overexpressing folate receptors was used in the fluorescence studies of liposomal uptake. The B16-F10 melanoma cell line was used for confirming, by flow cytometry and confocal microscopy, doxorubicin intracellular transfer as well as to induce experimental tumors in C57BL/6 mice. Animal therapy was achieved with injections of vascular-disrupting peptide, doxorubicin-loaded liposomes, or alternating combined therapy. The results (tumor growth inhibition and survival) were compared using the Mann-Whitney U test and the log-rank test. Necrosis in H&E-stained tumor sections was assessed microscopically by pathologists. Treatment of C57BL/6 mice bearing B16-F10 experimental tumors with a combination of vascular-disruptive peptide and doxorubicin-carrying pegylated liposomes (either passively targeted liposomes (PTL) or folate receptor targeted) gave better therapeutic effects when tumor development was re-challenged with a second cycle of combined therapy. Marked inhibition of tumor growth and a statistically significant extension of the lifespan of the treated mice were

A Novel Isoquinoline Derivative Anticancer Agent and Its Targeted Delivery to Tumor Cells Using Transferrin-Conjugated Liposomes

PubMed Central

Yang, Xuewei; Yang, Shuang; Chai, Hongyu; Yang, Zhaogang; Lee, Robert J.; Liao, Weiwei; Teng, Lesheng

2015-01-01

We have screened 11 isoquinoline derivatives and α-methylene-γ-butyrolactones using the 3-(4,5-dimethylthi-azol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay in HeLa and HEK-293T cells. Compound 2 was identified as potential anticancer agent. To further improve its therapeutic potential, this agent was incorporated into transferrin (Tf)-conjugated liposomes (LPs) for targeted delivery to tumor cells. We have demonstrated Tf-LP-Compound 2 have superior antitumor activity compared to non-targeted controls and the free drug. These data show Tf-LP-Compound 2 to be a promising agent that warrants further evaluation. PMID:26309138

Targeted light-inactivation of the Ki-67 protein using theranostic liposomes leads to death of proliferating cells

NASA Astrophysics Data System (ADS)

Rahmanzadeh, Ramtin; Rai, Prakash; Gerdes, Johannes; Hasan, Tayyaba

2010-02-01

Nanomedicine is beginning to impact the treatment of several diseases and current research efforts include development of integrated nano-constructs (theranostics) which serve as probes for imaging and therapy in addition to delivering macromolecules intracellularly. In cancer, there is a vital unmet need for effective alternative treatments with high specificity and low systemic toxicity. This can be achieved by targeting key molecular markers associated with cancer cells with reduced effective drug doses. Here, we show an innovative proof-of-principle approach for efficient killing of proliferating ovarian cancer cells by inactivating a protein associated with cell proliferation namely, the nuclear Ki-67 protein (pKi-67), using nanotechnology-based photodynamic therapy (PDT). Antibodies against pKi-67 are widely used as prognostic tools for tumor diagnosis. In this work, anti pKi-67 antibodies were first conjugated to fluorescein isothiocyanate (FITC) and then encapsulated inside liposomes. After incubation of OVCAR-5 ovarian cancer cells with these liposomes, confocal microscopy confirmed the localization of the antibodies to the nucleoli of the cells. Irradiation with a 488 nm laser led to a significant loss of cell viability. The specificity of this approach for pKi-67 positive cells was demonstrated in confluent human lung fibroblasts (MRC-5) where only a small population of cells stain positive for pKi-67 and only minimal cell death was observed. Taken together, our findings suggest that pKi-67 targeted with nano-platform is an attractive therapeutic target in cancer therapy.

Peritoneal retention of liposomes: Effects of lipid composition, PEG coating and liposome charge.

PubMed

Dadashzadeh, S; Mirahmadi, N; Babaei, M H; Vali, A M

2010-12-01

for negatively charged liposomes. The positively charged PEGylated vesicles (DOTAP/PEG 100) had the second-greatest peritoneal level after DOTAP 1000; however, their peritoneal-to-blood AUC ratio was low (3.05). Overall, among the different liposomal formulations, the positively charged conventional liposomes (100 and 1000nm) provided greater peritoneal levels and retention. DOTAP/PEG100 may also be a more efficient formulation because this formulation can provide a high level of anticancer drug into the peritoneal cavity and also can passively target the primary tumor. Copyright © 2010 Elsevier B.V. All rights reserved.

Design of ligand-targeted nanoparticles for enhanced cancer targeting

NASA Astrophysics Data System (ADS)

Stefanick, Jared F.

Ligand-targeted nanoparticles are increasingly used as drug delivery vehicles for cancer therapy, yet have not consistently produced successful clinical outcomes. Although these inconsistencies may arise from differences in disease models and target receptors, nanoparticle design parameters can significantly influence therapeutic efficacy. By employing a multifaceted synthetic strategy to prepare peptide-targeted nanoparticles with high purity, reproducibility, and precisely controlled stoichiometry of functionalities, this work evaluates the roles of polyethylene glycol (PEG) coating, ethylene glycol (EG) peptide-linker length, peptide hydrophilicity, peptide density, and nanoparticle size on tumor targeting in a systematic manner. These parameters were analyzed in multiple disease models by targeting human epidermal growth factor receptor 2 (HER2) in breast cancer and very late antigen-4 (VLA-4) in multiple myeloma to demonstrate the widespread applicability of this approach. By increasing the hydrophilicity of the targeting peptide sequence and simultaneously optimizing the EG peptide-linker length, the in vitro cellular uptake of targeted liposomes was significantly enhanced. Specifically, including a short oligolysine chain adjacent to the targeting peptide sequence effectively increased cellular uptake ~80-fold using an EG6 peptide-linker compared to ~10-fold using an EG45 linker. In vivo, targeted liposomes prepared in a traditional manner lacking the oligolysine chain demonstrated similar biodistribution and tumor uptake to non-targeted liposomes. However, by including the oligolysine chain, targeted liposomes using an EG45 linker significantly improved tumor uptake ~8-fold over non-targeted liposomes, while the use of an EG6 linker decreased tumor accumulation and uptake, owing to differences in cellular uptake kinetics, clearance mechanisms, and binding site barrier effects. To further improve tumor targeting and enhance the selectivity of targeted

Biophysical aspects of using liposomes as delivery vehicles.

PubMed

Ulrich, Anne S

2002-04-01

Liposomes are used as biocompatible carriers of drugs, peptides, proteins, plasmic DNA, antisense oligonucleotides or ribozymes, for pharmaceutical, cosmetic, and biochemical purposes. The enormous versatility in particle size and in the physical parameters of the lipids affords an attractive potential for constructing tailor-made vehicles for a wide range of applications. Some of the recent literature will be reviewed here and presented from a biophysical point of view, thus providing a background for the more specialized articles in this special issue on liposome technology. Different properties (size, colloidal behavior, phase transitions, and polymorphism) of diverse lipid formulations (liposomes, lipoplexes, cubic phases, emulsions, and solid lipid nanoparticles) for distinct applications (parenteral, transdermal, pulmonary, and oral administration) will be rationalized in terms of common structural, thermodynamic and kinetic parameters of the lipids. This general biophysical basis helps to understand pharmaceutically relevant aspects such as liposome stability during storage and towards serum, the biodistribution and specific targeting of cargo, and how to trigger drug release and membrane fusion. Methods for the preparation and characterization of liposomal formulations in vitro will be outlined, too.

Roles of dextrans on improving lymphatic drainage for liposomal drug delivery system.

PubMed

Feng, Linglin; Zhang, Lei; Liu, Min; Yan, Zhiqiang; Wang, Chenyu; Gu, Bing; Liu, Yu; Wei, Gang; Zhong, Gaoren; Lu, Weiyue

2010-04-01

Our aim was to develop a novel liposomal drug delivery system containing dextrans to reduce undesirable retention of antineoplastic agents and thus alleviate local tissue damage. At the cell level, diethylaminoethyl-dextran (DEAE-Dx) showed the strongest inhibiting effect on liposome uptake by macrophages among tested dextrans. The distribution of radiolabeled liposomes mixed with dextrans in injection site and draining lymph node was investigated in rats after subcutaneous injection. DEAE-Dx substantially reduced the undesired local retention and promoted the draining of liposome into lymphatics, which was further confirmed by confocal microscopy images revealing the substantial prevention of rhodamine B-labelled liposome sequestration by macrophages in normal lymph node in rats. Pharmacokinetic data indicated the accelerated drainage of liposome through lymphatics back to systemic circulation by mixing with DEAE-Dx. In the toxicological study in rabbits, DEAE-Dx alleviated the local tissue damage caused by liposomal doxorubicin. In conclusion, dextrans, particularly DEAE-Dx, could efficiently enhanced liposomes drainage into lymphatics, which proves themselves as promising adjuvants for lymphatic-targeted liposomal drug delivery system.

Alendronate-coated long-circulating liposomes containing 99mtechnetium-ceftizoxime used to identify osteomyelitis

PubMed Central

Ferreira, Diego dos Santos; Boratto, Fernanda Alves; Cardoso, Valbert Nascimento; Serakides, Rogéria; Fernandes, Simone Odília; Ferreira, Lucas Antônio Miranda; Oliveira, Mônica Cristina

2015-01-01

Osteomyelitis is a progressive destruction of bones caused by microorganisms. Inadequate or absent treatment increases the risk of bone growth inhibition, fractures, and sepsis. Among the diagnostic techniques, functional images are the most sensitive in detecting osteomyelitis in its early stages. However, these techniques do not have adequate specificity. By contrast, radiolabeled antibiotics could improve selectivity, since they are specifically recognized by the bacteria. The incorporation of these radiopharmaceuticals in drug-delivery systems with high affinity for bones could improve the overall uptake. In this work, long-circulating and alendronate-coated liposomes containing 99mtechnetium-radiolabeled ceftizoxime were prepared and their ability to identify infectious foci (osteomyelitis) in animal models was evaluated. The effect of the presence of PEGylated lipids and surface-attached alendronate was evaluated. The bone-targeted long-circulating liposomal 99mtechnetium–ceftizoxime showed higher uptake in regions of septic inflammation than did the non-long-circulating and/or alendronate-non-coated liposomes, showing that both the presence of PEGylated lipids and alendronate coating are important to optimize the bone targeting. Scintigraphic images of septic or aseptic inflammation-bearing Wistar rats, as well as healthy rats, were acquired at different time intervals after the intravenous administration of these liposomes. The target-to-non-target ratio proved to be significantly higher in the osteomyelitis-bearing animals for all investigated time intervals. Biodistribution studies were also performed after the intravenous administration of the formulation in osteomyelitis-bearing animals. A significant amount of liposomes were taken up by the organs of the mononuclear phagocyte system (liver and spleen). Intense renal excretion was also observed during the entire experiment period. Moreover, the liposome uptake by the infectious focus was significantly

Sonoporation enhances liposome accumulation and penetration in tumors with low EPR.

PubMed

Theek, Benjamin; Baues, Maike; Ojha, Tarun; Möckel, Diana; Veettil, Seena Koyadan; Steitz, Julia; van Bloois, Louis; Storm, Gert; Kiessling, Fabian; Lammers, Twan

2016-06-10

The Enhanced Permeability and Retention (EPR) effect is a highly variable phenomenon. To enhance EPR-mediated passive drug targeting to tumors, several different pharmacological and physical strategies have been evaluated over the years, including e.g. TNFα-treatment, vascular normalization, hyperthermia and radiotherapy. Here, we systematically investigated the impact of sonoporation, i.e. the combination of ultrasound (US) and microbubbles (MB), on the tumor accumulation and penetration of liposomes. Two different MB formulations were employed, and their ability to enhance liposome accumulation and penetration was evaluated in two different tumor models, which are both characterized by relatively low levels of EPR (i.e. highly cellular A431 epidermoid xenografts and highly stromal BxPC-3 pancreatic carcinoma xenografts). The liposomes were labeled with two different fluorophores, enabling in vivo computed tomography/fluorescence molecular tomography (CT-FMT) and ex vivo two-photon laser scanning microscopy (TPLSM). In both models, in spite of relatively high inter- and intra-individual variability, a trend towards improved liposome accumulation and penetration was observed. In treated tumors, liposome concentrations were up to twice as high as in untreated tumors, and sonoporation enhanced the ability of liposomes to extravasate out of the blood vessels into the tumor interstitium. These findings indicate that sonoporation may be a useful strategy for improving drug targeting to tumors with low EPR. Copyright © 2016 Elsevier B.V. All rights reserved.

Doped colorimetric assay liposomes

DOEpatents

Charych, Deborah; Stevens, Raymond C.

2001-01-01

The present invention provides compositions comprising colorimetric assay liposomes. The present invention also provides methods for producing colorimetric liposomes and calorimetric liposome assay systems. In preferred embodiments, these calorimetric liposome systems provide high levels of sensitivity through the use of dopant molecules. As these dopants allow the controlled destabilization of the liposome structure, upon exposure of the doped liposomes to analyte(s) of interest, the indicator color change is facilitated and more easily recognized.

Simultaneous measurement of liposome extravasation and content release in tumors.

PubMed

Wu, N Z; Braun, R D; Gaber, M H; Lin, G M; Ong, E T; Shan, S; Papahadjopoulos, D; Dewhirst, M W

1997-03-01

The success of liposome-based drug delivery systems for tumor targeting relies on maximum extravasation of liposomes into tumor interstitium, as well as optimal release of contents from the liposomes once within the tumor Liposome extravasation and content release are two separate processes that can be individually or jointly manipulated so a method is needed to monitor these two processes independently and simultaneously. In this report, we describe a method to measure liposome extravasation and content release in tumor tissues growing in a rat skinfold window chamber preparation. Mixtures of liposomes containing either doxorubicin or calcein, both of which are fluorescent, and liposomes surface-labeled with rhodamine were injected intravenously. Fluorescent, light intensities in a tumor region in two fluorescent channels were measured using an image-processing system. Light intensities of plasma from blood samples were also measured using this system. These measurements were used to calculate the amounts of liposomes and released contents in both plasma and tumor interstitium. The calculations were based on the fact that the liposome surface labels and contents emit fluorescent light at different wavelengths and when encapsulated, the contents fluorescence is self-quenched. The model included equations to account for fluorescent light "cross-contamination" by the two fluorochromes as well as equations relating the measured fluorescent light intensities to the amounts of liposomes and released contents. This method was applied to three situations in which liposome extravasation and content release were manipulated in different, predictable ways. Our results indicate that this method can perform simultaneous independent and quantitative measurements of liposome extravasation and content release. This method can potentially be used to study drug delivery of other carrier systems in vivo.

Sialylneolacto-N-tetraose c (LSTc)-bearing Liposomal Decoys Capture Influenza A Virus*

PubMed Central

Hendricks, Gabriel L.; Weirich, Kim L.; Viswanathan, Karthik; Li, Jing; Shriver, Zachary H.; Ashour, Joseph; Ploegh, Hidde L.; Kurt-Jones, Evelyn A.; Fygenson, Deborah K.; Finberg, Robert W.; Comolli, James C.; Wang, Jennifer P.

2013-01-01

Influenza is a severe disease in humans and animals with few effective therapies available. All strains of influenza virus are prone to developing drug resistance due to the high mutation rate in the viral genome. A therapeutic agent that targets a highly conserved region of the virus could bypass resistance and also be effective against multiple strains of influenza. Influenza uses many individually weak ligand binding interactions for a high avidity multivalent attachment to sialic acid-bearing cells. Polymerized sialic acid analogs can form multivalent interactions with influenza but are not ideal therapeutics due to solubility and toxicity issues. We used liposomes as a novel means for delivery of the glycan sialylneolacto-N-tetraose c (LSTc). LSTc-bearing decoy liposomes form multivalent, polymer-like interactions with influenza virus. Decoy liposomes competitively bind influenza virus in hemagglutination inhibition assays and inhibit infection of target cells in a dose-dependent manner. Inhibition is specific for influenza virus, as inhibition of Sendai virus and respiratory syncytial virus is not observed. In contrast, monovalent LSTc does not bind influenza virus or inhibit infectivity. LSTc decoy liposomes prevent the spread of influenza virus during multiple rounds of replication in vitro and extend survival of mice challenged with a lethal dose of virus. LSTc decoy liposomes co-localize with fluorescently tagged influenza virus, whereas control liposomes do not. Considering the conservation of the hemagglutinin binding pocket and the ability of decoy liposomes to form high avidity interactions with influenza hemagglutinin, our decoy liposomes have potential as a new therapeutic agent against emerging influenza strains. PMID:23362274

PLGA/polymeric liposome for targeted drug and gene co-delivery.

PubMed

Wang, Hanjie; Zhao, Peiqi; Su, Wenya; Wang, Sheng; Liao, Zhenyu; Niu, Ruifang; Chang, Jin

2010-11-01

Chemotherapy is one of the most effective approaches to treat cancers in the clinic, but the problems, such as multidrug resistance (MDR), low bioavailability and toxicity, severely constrain the further application of chemotherapy. Our group recently reported that cationic PLGA/folate coated PEGlated polymeric liposome core-shell nanoparticles (PLGA/FPL NPs). It was self-assembled from a hydrophobic PLGA core and a hydrophilic folate coated PEGlated lipid shell for targeting co-delivery of drug and gene. Hydrophobic drugs can be incorporated into the core and the cationic shell of the drug-loaded nanoparticles can be used to bind DNA. The drug-loaded PLGA/FPL NPs/DNA complexes offer advantages to overcome these problems mentioned above, such as co-delivery of drugs and DNA to improving the chemosensitivity of cancer cells at a gene level, and targeting delivery of drug to the cancer tissue that enhance the bioavailability and reduce the toxicity. The experiment showed that nanoparticles have core-shell structure with nanosize, sustained drug release profile and good DNA-binding ability. Importantly, the core-shell nanoparticles achieve the possibility of co-delivering drugs and genes to the same cells with high gene transfection and drug delivery efficiency. Our data suggest that the PLGA/FPL NPs may be a useful drug and gene co-delivery system. Copyright © 2010 Elsevier Ltd. All rights reserved.

Liposomal nanoparticles as a drug delivery vehicle against osteosarcoma

NASA Astrophysics Data System (ADS)

Dhule, Santosh Subhashrao

with folate for targeted delivery in vivo, a significant reduction in tumor size was observed with C6-curcumin-folate liposomes. The encapsulation of two water insoluble drugs, curcumin and C6, in the lipid bilayer of liposomes enhances the cytotoxic effect and validates the potential of combined drug therapy.

Cross-linkable liposomes stabilize a magnetic resonance contrast-enhancing polymeric fastener.

PubMed

Smith, Cartney E; Kong, Hyunjoon

2014-04-08

Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads.

Cross-Linkable Liposomes Stabilize a Magnetic Resonance Contrast-Enhancing Polymeric Fastener

PubMed Central

2015-01-01

Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads. PMID:24635565

Plasmon resonant liposomes for controlled drug delivery

NASA Astrophysics Data System (ADS)

Knights-Mitchell, Shellie S.; Romanowski, Marek

2015-03-01

Nanotechnology use in drug delivery promotes a reduction in systemic toxicity, improved pharmacokinetics, and better drug bioavailability. Liposomes continue to be extensively researched as drug delivery systems (DDS) with formulations such as Doxil® and Ambisome® approved by FDA and successfully marketed in the United States. However, the limited ability to precisely control release of active ingredients from these vesicles continues to challenge the broad implementation of this technology. Moreover, the full potential of the carrier to sequester drugs until it can reach its intended target has yet to be realized. Here, we describe a liposomal DDS that releases therapeutic doses of an anticancer drug in response to external stimulus. Earlier, we introduced degradable plasmon resonant liposomes. These constructs, obtained by reducing gold on the liposome surface, facilitate spatial and temporal release of drugs upon laser light illumination that ultimately induces an increase in temperature. In this work, plasmon resonant liposomes have been developed to stably encapsulate and retain doxorubicin at physiological conditions represented by isotonic saline at 37o C and pH 7.4. Subsequently, they are stimulated to release contents either by a 5o C increase in temperature or by laser illumination (760 nm and 88 mW/cm2 power density). Successful development of degradable plasmon resonant liposomes responsive to near-infrared light or moderate hyperthermia can provide a new delivery method for multiple lipophilic and hydrophilic drugs with pharmacokinetic profiles that limit clinical utility.

Long-Circulating and pH-Sensitive Liposome Preparation Trapping a Radiotracer for Inflammation Site Detection.

PubMed

Mota, Luciene Das Graças; de Barros, André Luís Branco; Fuscaldi, Leonardo Lima; de Oliveira, Mônica Cristina; Cardoso, Valbert Nascimento

2015-06-01

Inflammatory and infectious diseases are one of the most common causes of mortality and morbidity. This paper aimed to prepare and to evaluate the ability of long-circulating and pH-sensitive liposomes, trapping a radiotracer, to identify inflamed focus. The physicochemical characterization of freeze-dried liposomes, using glucose as cryoprotectant, showed 80% of the vesicles with adequate mean diameter and good vesicle size homogeneity. Radiotracer encapsulation percentage in liposomes was 10.65%, of which 4.88% was adsorbed on the surface of the vesicles. Furthermore, liposomes presented positive zeta potential. Freeze-dried liposomes, stored for 180 days at 4 degrees C, did not show significant changes in the mean diameter, indicating good stability. Free radiotracer and radiolabeled liposomes were injected into inflammation focus-bearing rats, and ex-vivo biodistribution studies and scintigraphic images were performed. Results showed that radiopharmaceutical, free and encapsulated into liposomes, were able to identify the inflamed site. Target/non-target ratios, obtained by scintigraphic images, were greater than 1.5 at all investigated times. Data did not show significant differences between the free radiotracer and radiolabeled liposomes. Results suggest that this liposomal preparation could be employed as an alternative procedure for inflamed site detection by means of scintigraphic images. However, as the radiotracer is adsorbed onto the liposome surface by electrostatic forces, it is suggested that a neutral radiopharmaceutical be used to confirm the potential of this formulation as a scintigraphic probe for inflammation/infection detection.

pH-Sensitive PEGylated liposomes functionalized with a fibronectin-mimetic peptide show enhanced intracellular delivery to colon cancer cell.

PubMed

Garg, Ashish; Kokkoli, Efrosini

2011-08-01

pH-sensitive liposomes undergo rapid destabilization under mildly acidic conditions such as those found in endocytotic vesicles. Though this makes them promising drug carriers, their application is limited due to their rapid clearance from circulation by the reticulo-endothelial system. Researchers have therefore used pH-sensitive liposomes that are sterically stabilized by polyethylene glycol (PEG) molecules (stealth liposomes) on the liposome surface. The goal of this study is to bring bio-functionality to pH-sensitive PEGylated liposomes in order to facilitate their potential use as a targeted drug delivery agent. To improve the selectivity of these nanoparticles, we included a targeting moiety, PR_b which specifically recognizes and binds to integrin α(5)β(1) expressing cells. PR_b (KSSPHSRN(SG)(5)RGDSP) is a novel fibronectin-mimetic peptide sequence that mimics the cell adhesion domain of fibronectin. Integrin α(5)β(1) is expressed on several types of cancer cells, including colon cancer, and plays an important role in tumor growth and metastasis. We have thoroughly studied the release of calcein from pH-sensitive PEGylated liposomes by varying the lipid composition of the liposomes in the absence and presence of the targeting peptide, PR_b, and accounting for the first time for the effect of both pH and time (photo-bleaching effect) on the fluorescence signal of calcein. We have demonstrated that we can design PR_b-targeted pH-sensitive PEGylated liposomes, which can undergo destabilization under mildly acidic conditions and have shown that incorporating the PR_b peptide does not significantly affect the pH-sensitivity of the liposomes. PR_b-targeted pH-sensitive PEGylated liposomes bind to CT26.WT colon carcinoma cells that express integrin α(5)β(1), undergo cellular internalization, and release their load intracellularly in a short period of time as compared to other formulations. Our studies demonstrate that PR_b-functionalized pH-sensitive targeted

Non-Invasive Detection of Lung Inflammation by Near-Infrared Fluorescence Imaging Using Bimodal Liposomes.

PubMed

Desu, Hari R; Wood, George C; Thoma, Laura A

2016-01-01

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome results in respiratory obstruction and severe lung inflammation. Critical characteristics of ALI are alveolar edema, infiltration of leukocytes (neutrophils and monocytes), release of pro-inflammatory cytokines and chemokines into broncho-alveolar lavage fluid, and activation of integrin receptors. The purpose of the study was to demonstrate non-invasive detection of lung inflammation using integrin receptor targeted fluorescence liposomes. An inflammation similar to that observed in ALI was elicited in rodents by intra-tracheal instillation of interleukin-1beta (IL-1beta). Cyclic arginine glycine-(D)-aspartic acid-peptide (cRGD-peptide) grafted fluorescence liposomes were administered to ALI induced male Sprague-Dawley rats for targeting lung integrin receptors. Near-infrared fluorescence imaging (NIRFI) was applied for visualization and quantitation of lung inflammation. NIRFI signals were correlated with inflammatory cellular and biochemical markers of lungs. A positive correlation was observed between NIRF signals and lung inflammation markers. Compared to control group, an intense NIRF signal was observed in ALI induced rats in the window 6-24 h post-IL-1beta instillation. Interaction of integrin receptors with targeted liposomes was assumed to contribute to intense NIRF signal. RT-PCR studies showed an elevated lung expression of alphavbeta5 integrin receptors, 12 h post-IL-1beta instillation. In vitro studies demonstrated integrin receptor specificity of targeted liposomes. These targeted liposomes showed binding to alphavbeta5 integrin receptors expressed on alveolar cells. Non-invasive detection of lung inflammation was demonstrated using a combination of integrin receptor targeting and NIRFI.

Novel targeting of PEGylated liposomes for codelivery of TGF-β1 siRNA and four antitubercular drugs to human macrophages for the treatment of mycobacterial infection: a quantitative proteomic study

PubMed Central

Niu, Ning-Kui; Yin, Juan-Juan; Yang, Yin-Xue; Wang, Zi-Li; Zhou, Zhi-Wei; He, Zhi-Xu; Chen, Xiao-Wu; Zhang, Xueji; Duan, Wei; Yang, Tianxin; Zhou, Shu-Feng

2015-01-01

Tuberculosis (TB) is still a major public health issue in developing countries, and its chemotherapy is compromised by poor drug compliance and severe side effects. This study aimed to synthesize and characterize new multimodal PEGylated liposomes encapsulated with clinically commonly used anti-TB drugs with linkage to small interfering RNA (siRNA) against transforming growth factor-β1 (TGF-β1). The novel NP-siRNA liposomes could target THP-1-derived human macrophages that were the host cells of mycobacterium infection. The biological effects of the NP-siRNA liposomes were evaluated on cell cycle distribution, apoptosis, autophagy, and the gene silencing efficiency of TGF-β1 siRNA in human macrophages. We also explored the proteomic responses to the newly synthesized NP-siRNA liposomes using the stable isotope labeling with amino acids in cell culture approach. The results showed that the multifunctional PEGylated liposomes were successfully synthesized and chemically characterized with a mean size of 265.1 nm. The novel NP-siRNA liposomes functionalized with the anti-TB drugs and TGF-β1 siRNA were endocytosed efficiently by human macrophages as visualized by transmission electron microscopy and scanning electron microscopy. Furthermore, the liposomes showed a low cytotoxicity toward human macrophages. There was no significant effect on cell cycle distribution and apoptosis in THP-1-derived macrophages after drug exposure at concentrations ranging from 2.5 to 62.5 μg/mL. Notably, there was a 6.4-fold increase in the autophagy of human macrophages when treated with the NP-siRNA liposomes at 62.5 μg/mL. In addition, the TGF-β1 and nuclear factor-κB expression levels were downregulated by the NP-siRNA liposomes in THP-1-derived macrophages. The Ingenuity Pathway Analysis data showed that there were over 40 signaling pathways involved in the proteomic responses to NP-siRNA liposome exposure in human macrophages, with 160 proteins mapped. The top five canonical

Increased Liposome Extravasation in Selected Tissues: Effect of Substance P

NASA Astrophysics Data System (ADS)

Rosenecker, Joseph; Zhang, Weiming; Hong, Keelung; Lausier, James; Geppetti, Pierangelo; Yoshihara, Shigemi; Papahadjopoulos, Demetrios; Nadel, Jay A.

1996-07-01

We have used a pharmacologic mediator to open intercellular connections in selected vessels to allow liposomes to escape from the blood stream and to extravasate into tissues that have appropriate receptors. We have examined the effects of substance P (SP), a peptide known to increase vascular permeability in selected tissues, such as trachea, esophagus, and urinary bladder in rats. We used quantitative fluorescence analysis of tissues to measure two fluorescent markers, one attached to the lipid (rhodamine-phosphatidylethanolamine) and another, doxorubicin (an antitumor drug), encapsulated within the aqueous interior. We have also examined the deposition of liposomes microscopically by the use of encapsulated colloidal gold and silver enhancement. Analysis of the biochemical and morphological observations indicate the following: (i) Injection of SP produces a striking increase in both liposome labels, but only in tissues that possess receptors for SP in postcapillary venules; (ii) liposome material in these tissues has extravasated and is found extracellularly near a variety of cells beyond the endothelial layer over the first few hours; (iii) 24 h following injection of liposomes and SP, liposome material is found in these tissues, localized intracellularly in both endothelial cells and macrophages. We propose that appropriate application of tissue-specific mediators can result in liposome extravasation deep within tissues that normally do not take up significant amounts of liposomes from the blood. Such liposomes are able to carry a variety of pharmacological agents that can be released locally within selected target tissues for therapeutic purposes.

Synthesis and Functional Characterization of Novel Sialyl LewisX Mimic-Decorated Liposomes for E-selectin-Mediated Targeting to Inflamed Endothelial Cells.

PubMed

Chantarasrivong, Chanikarn; Ueki, Akiharu; Ohyama, Ryutaro; Unga, Johan; Nakamura, Shinya; Nakanishi, Isao; Higuchi, Yuriko; Kawakami, Shigeru; Ando, Hiromune; Imamura, Akihiro; Ishida, Hideharu; Yamashita, Fumiyoshi; Kiso, Makoto; Hashida, Mitsuru

2017-05-01

Sialyl LewisX (sLeX) is a natural ligand of E-selectin that is overexpressed by inflamed and tumor endothelium. Although sLeX is a potential ligand for drug targeting, synthesis of the tetrasaccharide is complicated with many reaction steps. In this study, structurally simplified novel sLeX analogues were designed and linked with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-2000 (DSPE-PEG) for E-selectin-mediated liposomal delivery. The sLeX structural simplification strategies include (1) replacement of the Gal-GlcNAc disaccharide unit with lactose to reduce many initial steps and (2) substitution of neuraminic acid with a negatively charged group, i.e., 3'-sulfo, 3'-carboxymethyl (3'-CM), or 3'-(1-carboxy)ethyl (3'-CE). While all the liposomes developed were similar in particle size and charge, the 3'-CE sLeX mimic liposome demonstrated the highest uptake in inflammatory cytokine-treated human umbilical vein endothelial cells (HUVECs), being even more potent than native sLeX-decorated liposomes. Inhibition studies using antiselectin antibodies revealed that their uptake was mediated primarily by overexpressed E-selectin on inflamed HUVECs. Molecular dynamics simulations were performed to gain mechanistic insight into the E-selectin binding differences among native and mimic sLeX. The terminally branched methyl group of the 3'-CE sLeX mimic oriented and faced the bulk hydrophilic solution during E-selectin binding. Since this state is entropically unfavorable, the 3'-CE sLeX mimic molecule might be pushed toward the binding pocket of E-selectin by a hydrophobic effect, leading to a higher probability of hydrogen-bond formation than native sLeX and the 3'-CM sLeX mimic. This corresponded with the fact that the 3'-CE sLeX mimic liposome exhibited much greater uptake than the 3'-CM sLeX mimic liposome.

Entrapment of ovalbumin into liposomes--factors affecting entrapment efficiency, liposome size, and zeta potential.

PubMed

Brgles, Marija; Jurasin, Darija; Sikirić, Maja Dutour; Frkanec, Ruza; Tomasić, Jelka

2008-01-01

Various amounts of Ovalbumin (OVA) were encapsulated into positively and negatively charged multilamellar liposomes, with the aim to investigate the entrapment efficiency in different buffers and to study their effects on the liposome size and zeta potential. Results showed that the entrapment efficiency of OVA in anionic liposomes was the same in 10 mM Phosphate Buffer (PB) as in Phosphate-Buffered Saline (PBS; PB + 0.15 M NaCl). Also, liposome size was approximately 1200 nm for all anionic liposomes incorporating OVA. The entrapment efficiency of OVA in cationic liposomes was highly dependent on ionic strength. The size of cationic liposomes was approximately 1200 nm in PBS, regardless of protein content, but increased with the amount of the incorporated protein in PB. Aggregation of cationic liposomes in PB was observed when the mass of the protein was 2.5 mg or greater. The zeta potential of anionic liposomes was negative and of cationic liposomes positive in the whole range of protein mass tested. These results show how different compositions of lipid and aqueous phases can be used to vary the entrapment efficiency, liposome size, and zeta potential--the factors that are of great importance for the use of liposomes as drug carriers.

Liposome-based drug co-delivery systems in cancer cells.

PubMed

Zununi Vahed, Sepideh; Salehi, Roya; Davaran, Soodabeh; Sharifi, Simin

2017-02-01

Combination therapy and nanotechnology offer a promising therapeutic method in cancer treatment. By improving drug's pharmacokinetics, nanoparticulate systems increase the drug's therapeutic effects while decreasing its adverse side effects related to high dosage. Liposomes are extensively used as drug delivery systems and several liposomal nanomedicines have been approved for clinical applications. In this regard, liposome-based combination chemotherapy (LCC) opens a novel avenue in drug delivery research and has increasingly become a significant approach in clinical cancer treatment. This review paper focuses on LCC strategies including co-delivery of: two chemotherapeutic drugs, chemotherapeutic agent with anti-cancer metals, and chemotherapeutic agent with gene agents and ligand-targeted liposome for co-delivery of chemotherapeutic agents. Definitely, the multidisciplinary method may help improve the efficacy of cancer therapy. An extensive literature review was performed mainly using PubMed. Copyright © 2016 Elsevier B.V. All rights reserved.

Feasibility and antitumor efficacy in vivo, of simultaneously targeting glycolysis, glutaminolysis and fatty acid synthesis using lonidamine, 6-diazo-5-oxo-L-norleucine and orlistat in colon cancer.

PubMed

Cervantes-Madrid, Diana; Dominguez-Gomez, Guadalupe; Gonzalez-Fierro, Aurora; Perez-Cardenas, Enrique; Taja-Chayeb, Lucia; Trejo-Becerril, Catalina; Duenas-Gonzalez, Alfonso

2017-03-01

The aim of the present study was to investigate in vivo the feasibility and efficacy of the combination of lonidamine (LND), 6-diazo-5-oxo-L-norleucine (DON) and orlistat to simultaneously target glycolysis, glutaminolysis and de novo synthesis of fatty acids, respectively. The doses of LND and DON used in humans were translated to mouse doses (77.7 mg/kg and 145.5 mg/kg, respectively) and orlistat was used at 240 mg/kg. Three schedules of LND, DON and orlistat at different doses were administered by intraperitoneal injection to BALB/c mice in a 21-day cycle (schedule 1: LND, 0.5 mg/day; DON, 0.25 mg/day 1, 5 and 9; orlistat, 240 mg/kg/day; schedule 2: LND, 0.1 mg/day; DON, 0.5 mg/day 1, 5 and 9; orlistat, 240 mg/kg/day; schedule 3: LND, 0.5 mg/day; DON, 0.08 mg/day 1, 5 and 9; orlistat, 360 mg/kg/day) to assess tolerability. To determine the antitumor efficacy, a syngeneic tumor model in BALB/c mice was created using colon cancer CT26.WT cells, and a xenogeneic tumor model was created in nude mice using the human colon cancer SW480 cell line. Mice were treated with schedule 1. Animals were weighed, clinically inspected during the experiment and the tumor volume was measured at day 21. The 3 schedules assessed in the tolerability experiments were well tolerated, as mice maintained their weight and no evident clinical signs of toxicity were observed. Combination treatment with schedule 1 significantly decreased tumor growth in each mouse model. No evident signs of toxicity were observed and mice maintained their weight during treatment. The triple metabolic blockade of the malignant phenotype appears feasible and promising for cancer therapy.

Feasibility and antitumor efficacy in vivo, of simultaneously targeting glycolysis, glutaminolysis and fatty acid synthesis using lonidamine, 6-diazo-5-oxo-L-norleucine and orlistat in colon cancer

PubMed Central

Cervantes-Madrid, Diana; Dominguez-Gomez, Guadalupe; Gonzalez-Fierro, Aurora; Perez-Cardenas, Enrique; Taja-Chayeb, Lucia; Trejo-Becerril, Catalina; Duenas-Gonzalez, Alfonso

2017-01-01

The aim of the present study was to investigate in vivo the feasibility and efficacy of the combination of lonidamine (LND), 6-diazo-5-oxo-L-norleucine (DON) and orlistat to simultaneously target glycolysis, glutaminolysis and de novo synthesis of fatty acids, respectively. The doses of LND and DON used in humans were translated to mouse doses (77.7 mg/kg and 145.5 mg/kg, respectively) and orlistat was used at 240 mg/kg. Three schedules of LND, DON and orlistat at different doses were administered by intraperitoneal injection to BALB/c mice in a 21-day cycle (schedule 1: LND, 0.5 mg/day; DON, 0.25 mg/day 1, 5 and 9; orlistat, 240 mg/kg/day; schedule 2: LND, 0.1 mg/day; DON, 0.5 mg/day 1, 5 and 9; orlistat, 240 mg/kg/day; schedule 3: LND, 0.5 mg/day; DON, 0.08 mg/day 1, 5 and 9; orlistat, 360 mg/kg/day) to assess tolerability. To determine the antitumor efficacy, a syngeneic tumor model in BALB/c mice was created using colon cancer CT26.WT cells, and a xenogeneic tumor model was created in nude mice using the human colon cancer SW480 cell line. Mice were treated with schedule 1. Animals were weighed, clinically inspected during the experiment and the tumor volume was measured at day 21. The 3 schedules assessed in the tolerability experiments were well tolerated, as mice maintained their weight and no evident clinical signs of toxicity were observed. Combination treatment with schedule 1 significantly decreased tumor growth in each mouse model. No evident signs of toxicity were observed and mice maintained their weight during treatment. The triple metabolic blockade of the malignant phenotype appears feasible and promising for cancer therapy. PMID:28454342

Systematic Review of Liposomal Bupivacaine (Exparel) for Postoperative Analgesia.

PubMed

Vyas, Krishna S; Rajendran, Sibi; Morrison, Shane D; Shakir, Afaaf; Mardini, Samir; Lemaine, Valerie; Nahabedian, Maurice Y; Baker, Stephen B; Rinker, Brian D; Vasconez, Henry C

2016-10-01

Management of postoperative pain often requires multimodal approaches. Suboptimal dosages of current therapies can leave patients experiencing periods of insufficient analgesia, often requiring rescue therapy. With absence of a validated and standardized approach to pain management, further refinement of treatment protocols and targeted therapeutics is needed. Liposomal bupivacaine (Exparel) is a longer acting form of traditional bupivacaine that delivers the drug by means of a multivesicular liposomal system. The effectiveness of liposomal bupivacaine has not been systematically analyzed relative to conventional treatments in plastic surgery. A comprehensive literature search of the MEDLINE, PubMed, and Google Scholar databases was conducted for studies published through October of 2015 with search terms related to liposomal bupivacaine and filtered for relevance to postoperative pain control in plastic surgery. Data on techniques, outcomes, complications, and patient satisfaction were collected. A total of eight articles were selected and reviewed from 160 identified. Articles covered a variety of techniques using liposomal bupivacaine for postoperative pain management. Four hundred five patients underwent procedures (including breast reconstruction, augmentation mammaplasty, abdominal wall reconstruction, mastectomy, and abdominoplasty) where pain was managed with liposomal bupivacaine and compared with those receiving traditional pain management. Liposomal bupivacaine use showed adequate safety and tolerability and, compared to traditional protocols, was equivalent or more effective in postoperative pain management. Liposomal bupivacaine is a safe method for postoperative pain control in the setting of plastic surgery and may represent an alternative to more invasive pain management systems such as patient-controlled analgesia, epidurals, peripheral nerve catheters, or intravenous narcotics.

Glycyrrhetinic Acid Liposomes Containing Mannose-Diester Lauric Diacid-Cholesterol Conjugate Synthesized by Lipase-Catalytic Acylation for Liver-Specific Delivery.

PubMed

Chen, Jing; Chen, Yuchao; Cheng, Yi; Gao, Youheng

2017-09-24

Mannose-diester lauric diacid-cholesterol (Man-DLD-Chol), as a liposomal target ligand, was synthesized by lipase catalyzed in a non-aqueous medium. Its chemical structure was confirmed by mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Glycyrrhetinic acid (GA) liposomes containing Man-DLD-Chol (Man-DLD-Chol-GA-Lp) were prepared by the film-dispersion method. We evaluated the characterizations of liposomes, drug-release in vitro, the hemolytic test, cellular uptake, pharmacokinetics, and the tissue distributions. The cellular uptake in vitro suggested that the uptake of Man-DLD-Chol-modified liposomes was significantly higher than that of unmodified liposomes in HepG2 cells. Pharmacokinetic parameters indicated that Man-DLD-Chol-GA-Lp was eliminated more rapidly than GA-Lp. In tissue distributions, the targeting efficiency (Te) of Man-DLD-Chol-GA-Lp on liver was 54.67%, relative targeting efficiency (R Te ) was 3.39, relative uptake rate (Re) was 4.78, and peak concentration ratio (Ce) was 3.46. All these results supported the hypothesis that Man-DLD-Chol would be an efficient liposomal carrier, and demonstrated that Man-DLD-Chol-GA-Lp has potential as a drug delivery for liver-targeting therapy.

Evaluation of pharmacokinetic and pharmacodynamic profiles of liposomes for the cell type-specific delivery of small molecule drugs.

PubMed

Dasa, Siva Sai Krishna; Suzuki, Ryo; Mugler, Emily; Chen, Lanlin; Jansson-Löfmark, Rasmus; Michaëlsson, Erik; Lindfors, Lennart; Klibanov, Alexander L; French, Brent A; Kelly, Kimberly A

2017-11-01

Liposome-based drug formulations represent an exciting avenue of research as they increase efficacy to toxicity ratios. Current formulations rely on passive accumulation to the disease site where drug is taken up by the cells. Ligand mediated targeting increases the net accumulation of liposomes, however, an unexplored benefit is to potentially refine pharmacodynamics (PD) of a drug specifically to different cell types within diseased tissue. As a model system, we engineered cardiomyocyte- (I-1) and endothelial-targeted (B-40) liposomes to carry a VEGFR2 inhibitor (PTK787), and examined the effect of cell type-specific delivery on both pharmacokinetics (PK) and PD. Neovascularization in post-myocardial infarction was significantly reduced by B-40 liposomes loaded with PTK787 as compared to animals injected with I-1 liposomes, and profoundly more as compared to free PTK787. This study thus shows that the intraorgan targeting of drugs through cell type-specific delivery holds substantial promise towards lowering the minimal efficacious dose administered systemically. Published by Elsevier Inc.

Secreted phospholipase A(2) as a new enzymatic trigger mechanism for localised liposomal drug release and absorption in diseased tissue.

PubMed

Davidsen, Jesper; Jørgensen, Kent; Andresen, Thomas L; Mouritsen, Ole G

2003-01-10

Polymer-coated liposomes can act as versatile drug-delivery systems due to long vascular circulation time and passive targeting by leaky blood vessels in diseased tissue. We present an experimental model system illustrating a new principle for improved and programmable drug-delivery, which takes advantage of an elevated activity of secretory phospholipase A(2) (PLA(2)) at the diseased target tissue. The secretory PLA(2) hydrolyses a lipid-based proenhancer in the carrier liposome, producing lyso-phospholipids and free fatty acids, which are shown in a synergistic way to lead to enhanced liposome destabilization and drug release at the same time as the permeability of the target membrane is enhanced. Moreover, the proposed system can be made thermosensitive and offers a rational way for developing smart liposome-based drug delivery systems. This can be achieved by incorporating specific lipid-based proenhancers or prodestabilisers into the liposome carrier, which automatically becomes activated by PLA(2) only at the diseased target sites, such as inflamed or cancerous tissue.

Cyclic-RGDyC functionalized liposomes for dual-targeting of tumor vasculature and cancer cells in glioblastoma: An in vitro boron neutron capture therapy study.

PubMed

Kang, Weirong; Svirskis, Darren; Sarojini, Vijayalekshmi; McGregor, Ailsa L; Bevitt, Joseph; Wu, Zimei

2017-05-30

The efficacy of boron neutron capture therapy depends on the selective delivery of 10B to the target. Integrins αvβ3 are transmembrane receptors over-expressed in both glioblastoma cells and its neovasculature. In this study, a novel approach to dual-target glioblastoma vasculature and tumor cells was investigated. Liposomes (124 nm) were conjugated with a αvβ3 ligand, cyclic arginine-glycine-aspartic acid-tyrosine-cysteine peptide (c(RGDyC)-LP) (1% molar ratio) through thiol-maleimide coupling. Expression of αvβ3 in glioblastoma cells (U87) and human umbilical vein endothelial cells (HUVEC), representing tumor angiogenesis, was determined using Western Blotting with other cells as references. The results showed that both U87 and HUVEC had stronger expression of αvβ3 than other cell types, and the degree of cellular uptake of c(RGDyC)-LP correlated with the αvβ3-expression levels of the cells. In contrast, control liposomes without c(RGDyC) showed little cellular uptake, regardless of cell type. In an in vitro boron neutron capture therapy study, the c(RGDyC)-LP containing sodium borocaptate generated more rapid and significant lethal effects to both U87 and HUVEC than the control liposomes and drug solution. Interestingly, neutron irradiated U87 and HUVEC showed different types of subsequent cell death. In conclusion, this study has demonstrated the potential of a new dual-targeting strategy using c(RGDyC)-LP to improve boron neutron capture therapy for glioblastoma.

Cyclic-RGDyC functionalized liposomes for dual-targeting of tumor vasculature and cancer cells in glioblastoma: An in vitro boron neutron capture therapy study

PubMed Central

Kang, Weirong; Svirskis, Darren; Sarojini, Vijayalekshmi; McGregor, Ailsa L.; Bevitt, Joseph; Wu, Zimei

2017-01-01

The efficacy of boron neutron capture therapy depends on the selective delivery of 10B to the target. Integrins αvβ3 are transmembrane receptors over-expressed in both glioblastoma cells and its neovasculature. In this study, a novel approach to dual-target glioblastoma vasculature and tumor cells was investigated. Liposomes (124 nm) were conjugated with a αvβ3 ligand, cyclic arginine-glycine-aspartic acid-tyrosine-cysteine peptide (c(RGDyC)-LP) (1% molar ratio) through thiol-maleimide coupling. Expression of αvβ3 in glioblastoma cells (U87) and human umbilical vein endothelial cells (HUVEC), representing tumor angiogenesis, was determined using Western Blotting with other cells as references. The results showed that both U87 and HUVEC had stronger expression of αvβ3 than other cell types, and the degree of cellular uptake of c(RGDyC)-LP correlated with the αvβ3-expression levels of the cells. In contrast, control liposomes without c(RGDyC) showed little cellular uptake, regardless of cell type. In an in vitro boron neutron capture therapy study, the c(RGDyC)-LP containing sodium borocaptate generated more rapid and significant lethal effects to both U87 and HUVEC than the control liposomes and drug solution. Interestingly, neutron irradiated U87 and HUVEC showed different types of subsequent cell death. In conclusion, this study has demonstrated the potential of a new dual-targeting strategy using c(RGDyC)-LP to improve boron neutron capture therapy for glioblastoma. PMID:28402271

Liposomes as nanomedical devices

PubMed Central

Bozzuto, Giuseppina; Molinari, Agnese

2015-01-01

Since their discovery in the 1960s, liposomes have been studied in depth, and they continue to constitute a field of intense research. Liposomes are valued for their biological and technological advantages, and are considered to be the most successful drug-carrier system known to date. Notable progress has been made, and several biomedical applications of liposomes are either in clinical trials, are about to be put on the market, or have already been approved for public use. In this review, we briefly analyze how the efficacy of liposomes depends on the nature of their components and their size, surface charge, and lipidic organization. Moreover, we discuss the influence of the physicochemical properties of liposomes on their interaction with cells, half-life, ability to enter tissues, and final fate in vivo. Finally, we describe some strategies developed to overcome limitations of the “first-generation” liposomes, and liposome-based drugs on the market and in clinical trials. PMID:25678787

Development of a bone-targeted pH-sensitive liposomal formulation containing doxorubicin: physicochemical characterization, cytotoxicity, and biodistribution evaluation in a mouse model of bone metastasis.

PubMed

Ferreira, Diêgo Dos Santos; Faria, Samilla Dornelas; Lopes, Sávia Caldeira de Araújo; Teixeira, Cláudia Salviano; Malachias, Angelo; Magalhães-Paniago, Rogério; de Souza Filho, José Dias; Oliveira, Bruno Luis de Jesus Pinto; Guimarães, Alexander Ramos; Caravan, Peter; Ferreira, Lucas Antônio Miranda; Alves, Ricardo José; Oliveira, Mônica Cristina

2016-01-01

Despite recent advances in cancer therapy, the treatment of bone tumors remains a major challenge. A possible underlying hypothesis, limitation, and unmet need may be the inability of therapeutics to penetrate into dense bone mineral, which can lead to poor efficacy and high toxicity, due to drug uptake in healthy organs. The development of nanostructured formulations with high affinity for bone could be an interesting approach to overcome these challenges. To develop a liposomal formulation with high affinity for hydroxyapatite and the ability to release doxorubicin (DOX) in an acidic environment for future application as a tool for treatment of bone metastases. Liposomes were prepared by thin-film lipid hydration, followed by extrusion and the sulfate gradient-encapsulation method. Liposomes were characterized by average diameter, ζ-potential, encapsulation percentage, X-ray diffraction, and differential scanning calorimetry. Release studies in buffer (pH 7.4 or 5), plasma, and serum, as well as hydroxyapatite-affinity in vitro analysis were performed. Cytotoxicity was evaluated by MTT assay against the MDA-MB-231 cell line, and biodistribution was assessed in bone metastasis-bearing animals. Liposomes presented suitable diameter (~170 nm), DOX encapsulation (~2 mg/mL), controlled release, and good plasma and serum stability. The existence of interactions between DOX and the lipid bilayer was proved through differential scanning calorimetry and small-angle X-ray scattering. DOX release was faster when the pH was in the range of a tumor than at physiological pH. The bone-targeted formulation showed a strong affinity for hydroxyapatite. The encapsulation of DOX did not interfere in its intrinsic cytotoxicity against the MDA-MB-231 cell line. Biodistribution studies demonstrated high affinity of this formulation for tumors and reduction of uptake in the heart. These results suggest that bone-targeted pH-sensitive liposomes containing DOX can be an interesting

Transient cerebral hypoperfusion assisted intraarterial cationic liposome delivery to brain tissue

PubMed Central

Joshi, Shailendra; Singh-Moon, Rajinder P.; Wang, Mei; Chaudhuri, Durba B.; Holcomb, Mark; Straubinger, Ninfa L.; Bruce, Jeffrey N.; Bigio, Irving J.; Straubinger, Robert M.

2014-01-01

Object Transient cerebral hypoperfusion (TCH) has empirically been used to assist intraarterial (IA) drug delivery to brain tumors. Transient (< 3 min) reduction of cerebral blood flow (CBF) occurs during many neuro- and cardiovascular interventions and has recently been used to better target IA drugs to brain tumors. In the present experiments, we assessed whether the effectiveness of IA delivery of cationic liposomes could be improved by TCH. Methods Cationic liposomes composed of 1:1 DOTAP:PC (dioleoyl-trimethylammonium-propane:phosphatidylcholine) were administered to three groups of Sprague Dawley rats. In the first group, we tested the effect of blood flow reduction on IA delivery of cationic liposomes. In the second group, we compared TCH-assisted IA liposomal delivery vs. intravenous (IV) administration of the same dose. In the third group, we assessed retention of cationic liposomes in brain four hours after TCH assisted delivery. The liposomes contained a near infrared dye, DilC18(7), whose concentration could be measured in vivo by diffuse reflectance spectroscopy. Results IA injections of cationic liposomes during TCH increased their delivery approximately four-fold compared to injections during normal blood flow. Optical pharmacokinetic measurements revealed that relative to IV injections, IA injection of cationic liposomes during TCH produced tissue concentrations that were 100-fold greater. The cationic liposomes were retained in the brain tissue four hours after a single IA injection. There was no gross impairment of neurological functions in surviving animals. Conclusions Transient reduction in CBF significantly increased IA delivery of cationic liposomes in the brain. High concentrations of liposomes could be delivered to brain tissue after IA injections with concurrent TCH while none could be detected after IV injection. IA-TCH injections were well tolerated and cationic liposomes were retained for at least 4 hours after IA administration. These

Lonidamine affects testicular steroid hormones in immature mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Traina, Maria Elsa; Guarino, Maria; Natoli, Alessia

The effects on the hypothalamus-pituitary-testicular axis of the well-known antispermatogenic drug lonidamine (LND) has not been elucidated so far. In the present study, the possible changes of the testicular steroid hormones were evaluated in immature mice for a better characterization of the LND adverse effects both in its use as antitumoral agent and male contraceptive. Male CD1 mice were orally treated on postnatal day 28 (PND28) with LND single doses (0 or 100 mg/kg b.w.) and euthanized every 24 h from PND29 to PND32, on PND35 and on PND42 (1 and 2 weeks after the administration, respectively). Severe testicular effectsmore » were evidenced in the LND treated groups, including: a) significant testis weight increase, 24 h and 48 h after dosing; b) sperm head counts decrease (more than 50% of the control) on PND29-32; c) damage of the tubule morphology primarily on the Sertoli cell structure and germ cell exfoliation. All these reproductive endpoints were recovered on PND42. At the same time, a significant impairment of the testicular steroid balance was observed in the treated mice, as evidenced by the decrease of testosterone (T) and androstenedione (ADIONE) and the increase of 17OH-progesterone (17OH-P4) on the first days after dosing, while the testicular content of 17{beta}-estradiol (E2) was unchanged. The hormonal balance was not completely restored afterwards, as levels of T, ADIONE and 17OH-P4 tended to be higher in the treated mice than in the controls, on PND35 and PND42. These data showed for the first time that LND affects intratesticular steroids in experimental animals. However further data are needed both to elucidate the mechanism responsible for the impairment of these metabolic pathways and to understand if the androgens decrease observed after LND administration could be partially involved in the testicular damage.« less

Pharmaceutical liposomal drug delivery: a review of new delivery systems and a look at the regulatory landscape.

PubMed

Zylberberg, Claudia; Matosevic, Sandro

2016-11-01

Liposomes were the first nanoscale drug to be approved for clinical use in 1995. Since then, the technology has grown considerably, and pioneering recent work in liposome-based delivery systems has brought about remarkable developments with significant clinical implications. This includes long-circulating liposomes, stimuli-responsive liposomes, nebulized liposomes, elastic liposomes for topical, oral and transdermal delivery and covalent lipid-drug complexes for improved drug plasma membrane crossing and targeting to specific organelles. While the regulatory bodies' opinion on liposomes is well-documented, current guidance that address new delivery systems are not. This review describes, in depth, the current state-of-the-art of these new liposomal delivery systems and provides a critical overview of the current regulatory landscape surrounding commercialization efforts of higher-level complexity systems, the expected requirements and the hurdles faced by companies seeking to bring novel liposome-based systems for clinical use to market.

Paramagnetic liposomes as innovative contrast agents for magnetic resonance (MR) molecular imaging applications.

PubMed

Terreno, Enzo; Delli Castelli, Daniela; Cabella, Claudia; Dastrù, Walter; Sanino, Alberto; Stancanello, Joseph; Tei, Lorenzo; Aime, Silvio

2008-10-01

This article illustrates some innovative applications of liposomes loaded with paramagnetic lanthanide-based complexes in MR molecular imaging field. When a relatively high amount of a Gd(III) chelate is encapsulated in the vesicle, the nanosystem can simultaneously affect both the longitudinal (R(1)) and the transverse (R(2)) relaxation rate of the bulk H2O H-atoms, and this finding can be exploited to design improved thermosensitive liposomes whose MRI response is not longer dependent on the concentration of the probe. The observation that the liposome compartmentalization of a paramagnetic Ln(III) complex induce a significant R(2) enhancement, primarily caused by magnetic susceptibility effects, prompted us to test the potential of such agents in cell-targeting MR experiments. The results obtained indicated that these nanoprobes may have a great potential for the MR visualization of cellular targets (like the glutamine membrane transporters) overexpressing in tumor cells. Liposomes loaded with paramagnetic complexes acting as NMR shift reagents have been recently proposed as highly sensitive CEST MRI agents. The main peculiarity of CEST probes is to allow the MR visualization of different agents present in the same region of interest, and this article provides an illustrative example of the in vivo potential of liposome-based CEST agents.

Extended acute toxicity study of (188) Re-liposome in rats.

PubMed

Chi-Mou, Liu; Chia-Che, Tsai; Chia-Yu, Yu; Wan-Chi, Lee; Chung-Li, Ho; Tsui-Jung, Chang; Chih-Hsien, Chang; Te-Wei, Lee

2013-09-01

Liposomes can selectively target cancer sites and carry payloads, thereby improving diagnostic and therapeutic effectiveness as well as reducing toxicity. To evaluate therapeutic strategies, it is essential to use animal models reflecting important safety aspects before clinical application. As our previous study found that a high dosage (185 of MBq) of (188) Re-N,N-bis (2-mercaptoethyl)-N',N'-diethylethylenediamine-labeled pegylated liposomes ((188) Re-liposome) induced a decrease in white blood cell (WBC) count in Sprague-Dawley rats 7 days postinjection, the objective of the present study was to investigate extended acute radiotoxicity of (188) Re-liposome. Rats were administered via intravenous (i.v.) injection with (188) Re-liposome (185, 55.5 and 18.5 MBq), normal saline as a blank control or non-radioactive liposome as a vehicle control. Mortality, clinical signs, food consumption, body weights, urinary, biochemical and hematological analyzes were examined. In addition, gross necropsy and histopathological examinations were also performed at the end of the follow-up period. None of the rats died and no clinical sign was observed during the 28-day study period. Only male rats receiving (188) Re-liposome at a high dosage (185 MBq) displayed a slight weight loss compared with the control rats. In both male and female rats, the WBC counts of both high-dose and medium-dose (55.5 MBq) groups reduced significantly 7 days postinjection, but recovered to the normal range on Study Day 29. There was no significant difference in urinary analyzes, biochemical parameters and histopathological assessments between the (188) Re-liposome-treated and control groups. The information generated from the present study on extended acute toxicity of (188) Re-liposome will serve as a safety reference for radiopharmaceuticals in early-phase clinical trials. Copyright © 2012 John Wiley & Sons, Ltd.

Fusogenic pH sensitive liposomal formulation for rapamycin: improvement of antiproliferative effect.

PubMed

Ghanbarzadeh, Saeed; Khorrami, Arash; Mohamed Khosroshahi, Leila; Arami, Sanam

2014-07-01

Liposomes are increasingly employed to deliver chemotherapeutic agents, antisense oligonucleotides, and genes to various therapeutic targets. The present investigation evaluates the ability of fusogenic pH-sensitive liposomes of rapamycin in increasing its antiproliferative effect on human breast adenocarcinoma (MCF-7) cell line. Cholesterol (Chol) and dipalmitoylphosphatidylcholine (DPPC) (DPPC:Chol, 7:3) were used to prepare conventional rapamycin liposomes by a modified ethanol injection method. Dioleoylphosphatidylethanolamine (DOPE) was used to produce fusogenic and pH-sensitive properties in liposomes simultaneously (DPPC:Chol:DOPE, 7:3:4.2). The prepared liposomes were characterized by their size, zeta potential, encapsulation efficiency percent (EE%), and chemical stability during 6 months. The antiproliferative effects of both types of rapamycin liposomes (10, 25, and 50 nmol/L) with optimized formulations were assessed on MCF-7 cells, as cancerous cells, and human umbilical vein endothelial cells (HUVEC), as healthy cells, employing the diphenyltetrazolium bromide (MTT) assay for 72 h. The particle size, zeta potential, and EE% of the liposomes were 165 ± 12.3 and 178 ± 15.4 nm, -39.6 ± 1.3, and -41.2 ± 2.1 mV as well as 76.9 ± 2.6 and 76.9 ± 2.6% in conventional and fusogenic pH-sensitive liposomes, respectively. Physicochemical stability results indicated that both liposome types were relatively stable at 4 °C than 25 °C. In vitro antiproliferative evaluation showed that fusogenic pH-sensitive liposomes had better antiproliferative effects on MCF-7 cells compared to the conventional liposomes. Conversely, fusogenic pH-sensitive liposomes had less cytotoxicity on HUVEC cell line.

Liposome Disruption Assay to Examine Lytic Properties of Biomolecules.

PubMed

Jimah, John R; Schlesinger, Paul H; Tolia, Niraj H

2017-08-05

Proteins may have three dimensional structural or amino acid features that suggest a role in targeting and disrupting lipids within cell membranes. It is often necessary to experimentally investigate if these proteins and biomolecules are able to disrupt membranes in order to conclusively characterize the function of these biomolecules. Here, we describe an in vitro assay to evaluate the membrane lytic properties of proteins and biomolecules. Large unilamellar vesicles (liposomes) containing carboxyfluorescein at fluorescence-quenching concentrations are treated with the biomolecule of interest. A resulting increase in fluorescence due to leakage of the dye from liposomes and subsequent dilution in the buffer demonstrates that the biomolecule is sufficient for disrupting liposomes and membranes. Additionally, since liposome disruption may occur via pore-formation or via general solubilization of lipids similar to detergents, we provide a method to distinguish between these two mechanisms. Pore-formation can be identified and evaluated by examining the blockade of carboxyfluorescein release with dextran molecules that fit the pore. The methods described here were used to determine that the malaria vaccine candidate CelTOS and proapoptotic Bax disrupt liposomes by pore formation (Saito et al. , 2000; Jimah et al. , 2016). Since membrane lipid binding by a biomolecule precedes membrane disruption, we recommend the companion protocol: Jimah et al. , 2017.

Liposome formation in microgravity.

PubMed

Claassen, D E; Spooner, B S

1996-01-01

Liposomes are artificial vesicles with a phospholipid bilayer membrane. The formation of liposomes is a self-assembly process that is driven by the amphipathic nature of phospholipid molecules and can be observed during the removal of detergent from phospholipids dissolved in detergent micelles. As detergent concentration in the mixed micelles decreases, the non-polar tail regions of phospholipids produce a hydrophobic effect that drives the micelles to fuse and form planar bilayers in which phospholipids orient with tail regions to the center of the bilayer and polar head regions to the external surface. Remaining detergent molecules shield exposed edges of the bilayer sheet from the aqueous environment. Further removal of detergent leads to intramembrane folding and membrane folding and membrane vesiculation, forming liposomes. We have observed that the formation of liposomes is altered in microgravity. Liposomes that were formed at 1-g did not exceed 150 nm in diameter, whereas liposomes that were formed during spaceflight exhibited diameters up to 2000 nm. Using detergent-stabilized planar bilayers, we determined that the stage of liposome formation most influenced by gravity is membrane vesiculation. In addition, we found that small, equipment-induced fluid disturbances increased vesiculation and negated the size-enhancing effects of microgravity. However, these small disturbances had no effect on liposome size at 1-g, likely due to the presence of gravity-induced buoyancy-driven fluid flows (e.g., convection currents). Our results indicate that fluid disturbances, induced by gravity, influence the vesiculation of membranes and limit the diameter of forming liposomes.

Liposome formation in microgravity

NASA Astrophysics Data System (ADS)

Claassen, D. E.; Spooner, B. S.

Liposomes are artificial vesicles with a phospholipid bilayer membrane. The formation of liposomes is a self-assembly process that is driven by the amphipathic nature of phospholipid molecules and can be observed during the removal of detergent from phospholipids dissolved in detergent micelles. As detergent concentration in the mixed micelles decreases, the non-polar tail regions of phospholipids produce a hydrophobic effect that drives the micelles to fuse and form planar bilayers in which phospholipids orient with tail regions to the center of the bilayer and polar head regions to the external surface. Remaining detergent molecules shield exposed edges of the bilayer sheet from the aqueous environment. Further removal of detergent leads to intramembrane folding and membrane vesiculation, forming liposomes. We have observed that the formation of liposomes is altered in microgravity. Liposomes that were formed at 1-g did not exceed 150 nm in diameter, whereas liposomes that were formed during spaceflight exhibited diameters up to 2000 nm. Using detergent-stabilized planar bilayers, we determined that the stage of liposome formation most influenced by gravity is membrane vesiculation. In addition, we found that small, equipment-induced fluid disturbances increased vesiculation and negated the size-enhancing effects of microgravity. However, these small disturbances had no effect on liposome size at 1-g, likely due to the presence of gravity-induced buoyancy-driven fluid flows (e.g., convection currents). Our results indicate that fluid disturbances, induced by gravity, influence the vesiculation of membranes and limit the diameter of forming liposomes.

Liposomal adjuvants for human vaccines.

PubMed

Alving, Carl R; Beck, Zoltan; Matyas, Gary R; Rao, Mangala

2016-06-01

Liposomes are well-known as drug carriers, and are now critical components of two of six types of adjuvants present in licensed vaccines. The liposomal vaccine adjuvant field has long been dynamic and innovative, and research in this area is further examined as new commercial products appear in parallel with new vaccines. In an arena where successful products exist the potential for new types of vaccines with liposomal adjuvants, and alternative liposomal adjuvants that could emerge for new types of vaccines, are discussed. Major areas include: virosomes, constructed from phospholipids and proteins from influenza virus particles; liposomes containing natural and synthetic neutral or anionic phospholipids, cholesterol, natural or synthetic monophosphoryl lipid A, and QS21 saponin; non-phospholipid cationic liposomes; and combinations and mixtures of liposomes and immunostimulating ingredients as adjuvants for experimental vaccines. Liposomes containing monophosphoryl lipid A and QS21 have considerable momentum that will result soon in emergence of prophylactic vaccines to malaria and shingles, and possible novel cancer vaccines. The licensed virosome vaccines to influenza and hepatitis A will be replaced with virosome vaccines to other infectious diseases. Alternative liposomal formulations are likely to emerge for difficult diseases such as tuberculosis or HIV-1 infection.

Sustained Zero-Order Release of Intact Ultra-Stable Drug-Loaded Liposomes from an Implantable Nanochannel Delivery System

PubMed Central

Celia, Christian; Ferrati, Silvia; Bansal, Shyam; van de Ven, Anne L.; Ruozi, Barbara; Zabre, Erika; Hosali, Sharath; Paolino, Donatella; Sarpietro, Maria Grazia; Fine, Daniel; Fresta, Massimo; Ferrari, Mauro

2014-01-01

Metronomic chemotherapy supports the idea that long-term, sustained, constant administration of chemotherapeutics, currently not achievable, could be effective against numerous cancers. Particularly appealing are liposomal formulations, used to solubilize hydrophobic therapeutics and minimize side effects, while extending drug circulation time and enabling passive targeting. As liposome alone cannot survive in circulation beyond 48 hrs, sustaining their constant plasma level for many days is a challenge. To address this, we developed, as a proof of concept, an implantable nanochannel delivery system and ultra-stable PEGylated lapatinib loaded-liposomes, and we demonstrate the release of intact vesicles for over 18 days. Further, we investigate intravasation kinetics of subcutaneously delivered liposomes and verify their biological activity post nanochannel release on BT474 breast cancer cells. The key innovation of this work is the combination of two nanotechnologies to exploit the synergistic effect of liposomes, demonstrated as passive-targeting vectors and nanofluidics to maintain therapeutic constant plasma levels. In principle, this approach could maximize efficacy of metronomic treatments. PMID:23881575

Pulmonary Delivery of Anti-Tubercular Drugs Using Ligand Anchored pH Sensitive Liposomes for the Treatment of Pulmonary Tuberculosis.

PubMed

Bhardwaj, Ankur; Grobler, Anne; Rath, Goutam; Goyal, Amit Kumar; Jain, Amit Kumar; Mehta, Abhinav

2016-01-01

Mycobacterium tuberculosis (M. TB) remains the prime cause of bacterial mortality and morbidity world-wide. Therefore, effective delivery and targeting of drug to the cellular tropics is essentially required to generate significant results for tuberculosis treatment. The aim of the present study was to develop and characterize ligand anchored pH sensitive liposomes (TPSL) as dry powder inhaler for the targeted delivery of drugs in the target site i.e. lungs. Ligand anchored PSL (TPSL) was prepared by thin film hydration for the combined delivery of Isoniazid (INH) and Ciprofloxacin HCl (CIP HCl) using 4-aminophenyl-α-D mannopyranoside (Man) as surface functionalized ligand and characterized using different parameters. It was observed that size of the ligand anchored liposomes (TPSL) was slightly more than the non-ligand anchored liposomes (PSL). Drug release was studied at different pH for 24 hrs and it was observed that liposomes exhibited slow release at alkaline pH (58-64%) as compared to macrophage pH (81-87%) where it increased dramatically due to the destabilization of pH sensitive liposome (PSL). In vitro cellular uptake study showed that much higher concentration was achieved in the alveolar macrophage using ligand anchored liposomes as compared to its counterpart. In vivo study showed that maximum drug accumulation was achieved in the lung by delivering drug using ligand anchored PSL as compared to conventional PSL. It was concluded that ligand anchored pH sensitive liposome is one of the promising systems for the targeted drug therapy in pulmonary tuberculosis.

RGD(Arg-Gly-Asp) internalized docetaxel-loaded pH sensitive liposomes: Preparation, characterization and antitumor efficacy in vivo and in vitro.

PubMed

Zuo, Tiantian; Guan, Yuanyuan; Chang, Minglu; Zhang, Fang; Lu, Shanshan; Wei, Ting; Shao, Wei; Lin, Guimei

2016-11-01

The goal of this research was to formulate dual-targeting liposomes (RGD/DTX-PSL) that can selectively release loaded contents in a low pH level environment and to actively target to the tumor using liposomes that had surface arginine-glycine-aspartic (RGD) tripeptides. We investigated whether RGD/DTX-PSL could serve as an effective tumor-targeted nanoparticle that is capable of suppressing tumor growth. The results suggest that DTX is released from liposomes faster at pH 5.0 than pH 7.4, demonstrating their pH sensitivity. RGD/DTX-PSL has a longer blood circulation than Duopafei(®) in rats. The RGD/DTX-PSL formulation displayed stronger antiproliferative effects than DTX alone and the strongest inhibition of tumor growth of the formulations tested, thus expanding therapeutic window of DTX. In conclusion, we established a novel, promising and easy-to-handle liposome formulation that has a considerable antitumor activity in vitro and in vivo. This study provides important prerequisite for the clinical application of dual-targeting liposomes in delivering therapies. Copyright © 2016 Elsevier B.V. All rights reserved.

Binding and internalization of NGR-peptide-targeted liposomal doxorubicin (TVT-DOX) in CD13-expressing cells and its antitumor effects.

PubMed

Garde, Seema V; Forté, André J; Ge, Michael; Lepekhin, Eugene A; Panchal, Chandra J; Rabbani, Shafaat A; Wu, Jinzi J

2007-11-01

In an effort to develop new agents and molecular targets for the treatment of cancer, aspargine-glycine-arginine (NGR)-targeted liposomal doxorubicin (TVT-DOX) is being studied. The NGR peptide on the surface of liposomal doxorubicin (DOX) targets an aminopeptidase N (CD13) isoform, specific to the tumor neovasculature, making it a promising strategy. To further understand the molecular mechanisms of action, we investigated cell binding, kinetics of internalization as well as cytotoxicity of TVT-DOX in vitro. We demonstrate the specific binding of TVT-DOX to CD13-expressing endothelial [human umbilical vein endothelial cells (HUVEC) and Kaposi sarcoma-derived endothelial cells (SLK)] and tumor (fibrosarcoma, HT-1080) cells in vitro. Following binding, the drug was shown to internalize through the endosomal pathway, eventually leading to the localization of doxorubicin in cell nuclei. TVT-DOX showed selective toxicity toward CD13-expressing HUVEC, sparing the CD13-negative colon-cancer cells, HT-29. Additionally, the nontargeted counterpart of TVT-DOX, Caelyx, was less cytotoxic to the CD13-positive HUVECs demonstrating the advantages of NGR targeting in vitro. The antitumor activity of TVT-DOX was tested in nude mice bearing human prostate-cancer xenografts (PC3). A significant growth inhibition (up to 60%) of PC3 tumors in vivo was observed. Reduction of tumor vasculature following treatment with TVT-DOX was also apparent. We further compared the efficacies of TVT-DOX and free doxorubicin in the DOX-resistant colon-cancer model, HCT-116, and observed the more pronounced antitumor effects of the TVT-DOX formulation over free DOX. The potential utility of TVT-DOX in a variety of vascularized solid tumors is promising.

Effect of Liposome Characteristics and Dose on the Pharmacokinetics of Liposomes Coated with Poly(amino acid)s

PubMed Central

Romberg, Birgit; Oussoren, Christien; Snel, Cor J.; Hennink, Wim E.

2007-01-01

Long-circulating liposomes, such as PEG-liposomes, are frequently studied for drug delivery and diagnostic purposes. In our group, poly(amino acid) (PAA)-based coatings for long-circulating liposomes have been developed. These coatings provide liposomes with similar circulation times as compared to PEG-liposomes, but have the advantage of being enzymatically degradable. For PEG-liposomes it has been reported that circulation times are relatively independent of their physicochemical characteristics. In this study, the influence of factors such as PAA grafting density, cholesterol inclusion, surface charge, particle size, and lipid dose on the circulation kinetics of PAA-liposomes was evaluated after intravenous administration in rats. Prolonged circulation kinetics of PAA-liposomes can be maintained upon variation of liposome characteristics and the lipid dose given. However, the use of relatively high amounts of strongly charge-inducing lipids and a too large mean size is to be avoided. In conclusion, PAA-liposomes represent a versatile drug carrier system for a wide variety of applications. PMID:17674159

Drug delivery to the human and mouse uterus using immunoliposomes targeted to the oxytocin receptor.

PubMed

Paul, Jonathan W; Hua, Susan; Ilicic, Marina; Tolosa, Jorge M; Butler, Trent; Robertson, Sarah; Smith, Roger

2017-03-01

The ability to provide safe and effective pharmacotherapy during obstetric complications, such as preterm labor or postpartum hemorrhage, is hampered by the systemic toxicity of therapeutic agents leading to adverse side effects in the mother and fetus. Development of novel strategies to target tocolytic and uterotonic agents specifically to uterine myocytes would improve therapeutic efficacy while minimizing the risk of side effects. Ligand-targeted liposomes have emerged as a reliable and versatile platform for targeted drug delivery to specific cell types, tissues or organs. Our objective was to develop a targeted drug delivery system for the uterus utilizing an immunoliposome platform targeting the oxytocin receptor. We conjugated liposomes to an antibody that recognizes an extracellular domain of the oxytocin receptor. We then examined the ability of oxytocin receptor-targeted liposomes to deliver contraction-blocking (nifedipine, salbutamol and rolipram) or contraction-enhancing (dofetilide) agents to strips of spontaneously contracting myometrial tissue in vitro (human and mouse). We evaluated the ability of oxytocin receptor-targeted liposomes to localize to uterine tissue in vivo, and assessed if targeted liposomes loaded with indomethacin were capable of preventing lipopolysaccharide-induced preterm birth in mice. Oxytocin receptor-targeted liposomes loaded with nifedipine, salbutamol or rolipram consistently abolished human myometrial contractions in vitro, while oxytocin receptor-targeted liposomes loaded with dofetilide increased contraction duration. Nontargeted control liposomes loaded with these agents had no effect. Similar results were observed in mouse uterine strips. Following in vivo administration to pregnant mice, oxytocin receptor-targeted liposomes localized specifically to the uterine horns and mammary tissue. Targeting increased localization to the uterus 7-fold. Localization was not detected in the maternal brain or fetus. Targeted

Noninvasive control of the transport function of fluorescent coloured liposomal nanoparticles

NASA Astrophysics Data System (ADS)

Stelmashchuk, O.; Zherebtsov, E.; Zherebtsova, A.; Kuznetsova, E.; Vinokurov, A.; Dunaev, A.; Mamoshin, A.; Snimshchikova, I.; Borsukov, A.; Bykov, A.; Meglinski, I.

2017-06-01

The use of liposomal nanoparticles with an incorporated active substance is an innovative and promising approach to diagnostics and therapy. The application of liposomal nanoparticle-based drugs allows for targeted localized delivery, overcomes the natural barriers within the body effectively, and minimizes possible side effects. Liposomes are able to contain a variety of ingredients with practically no limitations to their chemical composition, chemical properties, or size of constituent molecules. This study evaluated the ability to control the passage of fluorescent dye-filled liposomes through the intestinal mucosal barrier after oral administration. For this purpose, the increase in transcutaneous registered fluorescence from tetrabromofluorescein dye was recorded and analysed. Fluorescence intensity was measured at the proximal end of the tail of an animal model after oral administration of the liposomes. Measurements were taken at the excitation wavelengths of 365 and 450 nm. The fluorescence intensity in the group treated with the fluorescent contrast agent encapsulated in liposomal particles increased 140% of the initial level, but in the group treated with pure contrast agent, the increase in detected fluorescence intensity did not exceed 110%. Mice that received empty liposomes as well as the control group did not demonstrate statistically significant changes in fluorescence intensity. A potential application of our results is an express laser optical method of monitoring the transport of orally administered liposomal particles. The results can be used to help create new optical tools for use in the development of new drugs and in high-throughput screening used during their testing.

The Multirole of Liposomes in Therapy and Prevention of Infectious Diseases

PubMed Central

Nisini, Roberto; Poerio, Noemi; Mariotti, Sabrina; De Santis, Federica; Fraziano, Maurizio

2018-01-01

Liposomes are closed bilayer structures spontaneously formed by hydrated phospholipids that are widely used as efficient delivery systems for drugs or antigens, due to their capability to encapsulate bioactive hydrophilic, amphipathic, and lipophilic molecules into inner water phase or within lipid leaflets. The efficacy of liposomes as drug or antigen carriers has been improved in the last years to ameliorate pharmacokinetics and capacity to release their cargo in selected target organs or cells. Moreover, different formulations and variations in liposome composition have been often proposed to include immunostimulatory molecules, ligands for specific receptors, or stimuli responsive compounds. Intriguingly, independent research has unveiled the capacity of several phospholipids to play critical roles as intracellular messengers in modulating both innate and adaptive immune responses through various mechanisms, including (i) activation of different antimicrobial enzymatic pathways, (ii) driving the fusion–fission events between endosomes with direct consequences to phagosome maturation and/or to antigen presentation pathway, and (iii) modulation of the inflammatory response. These features can be exploited by including selected bioactive phospholipids in the bilayer scaffold of liposomes. This would represent an important step forward since drug or antigen carrying liposomes could be engineered to simultaneously activate different signal transduction pathways and target specific cells or tissues to induce antigen-specific T and/or B cell response. This lipid-based host-directed strategy can provide a focused antimicrobial innate and adaptive immune response against specific pathogens and offer a novel prophylactic or therapeutic option against chronic, recurrent, or drug-resistant infections. PMID:29459867

Liposome-chaperoned cell-free synthesis for the design of proteoliposomes: Implications for therapeutic delivery.

PubMed

Lu, Mei; Zhao, Xiaoyun; Xing, Haonan; Xun, Zhe; Yang, Tianzhi; Cai, Cuifang; Wang, Dongkai; Ding, Pingtian

2018-04-03

Cell-free (CF) protein synthesis has emerged as a powerful technique platform for efficient protein production in vitro. Liposomes have been widely studied as therapeutic carriers due to their biocompatibility, biodegradability, low toxicity, flexible surface manipulation, easy preparation, and higher cargo encapsulation capability. However, rapid immune clearance, insufficient targeting capacity, and poor cytoplasmic delivery efficiency substantially restrict their clinical application. The incorporation of functional membrane proteins (MPs) or peptides allows the transfer of biological properties to liposomes and imparts them with improved circulation, increased targeting, and efficient intracellular delivery. Liposome-chaperoned CF synthesis enables production of proteoliposomes in one-step reaction, which not only substantially simplifies the production procedure but also keeps protein functionality intact. Building off these observations, proteoliposomes with integrated MPs represent an excellent candidate for therapeutic delivery. In this review, we describe recent advances in CF synthesis with emphasis on detailing key factors for improving CF expression efficiency. Furthermore, we provide insights into strategies for rational design of proteoliposomal nanodelivery systems via CF synthesis. Liposome-chaperoned CF synthesis has emerged as a powerful approach for the design of recombinant proteoliposomes in one-step reaction. The incorporation of bioactive MPs or peptides into liposomes via CF synthesis can facilitate the development of proteoliposomal nanodelivery systems with improved circulation, increased targeting, and enhanced cellular delivery capacity. Moreover, by adapting lessons learned from natural delivery vehicles, novel bio-inspired proteoliposomes with enhanced delivery properties could be produced in CF systems. In this review, we first give an overview of CF synthesis with focus on enhancing protein expression in liposome-chaperoned CF

Transferrin-modified liposome promotes α-mangostin to penetrate the blood-brain barrier.

PubMed

Chen, Zhi-Lan; Huang, Man; Wang, Xia-Rong; Fu, Jun; Han, Min; Shen, You-Qing; Xia, Zheng; Gao, Jian-Qing

2016-02-01

α-Mangostin (α-M) is a polyphenolic xanthone that protects and improves the survival of cerebral cortical neurons against Aβ oligomer-induced toxicity in rats. α-M is a potential candidate as a treatment for Alzheimer's disease (AD). However, the efficacy was limited by the poor penetration of the drug through the blood-brain barrier (BBB). In this study, we modified the α-M liposome with transferrin (Tf) and investigated the intracellular distribution of liposomes in bEnd3 cells. In addition, the transport of α-M across the BBB in the Tf(α-M) liposome group was examined. In vitro studies demonstrated that the Tf(α-M) liposome could cross the BBB in the form of an integrated liposome. Results of the in vivo studies on the α-M distribution in the brain demonstrated that the Tf(α-M) liposome improved the brain delivery of α-M. These results indicated that the Tf liposome is a potential carrier of α-M against AD. The use of α-Mangostin (α-M) as a potential agent to treat Alzheimer's disease (AD) has been reported. However, its use is limited by the poor penetration through the blood brain barrier. The delivery of this agent by transferrin-modified liposomes was investigated by the authors in this study. The positive results could point to a better drug delivery system for brain targeting. Copyright © 2015 Elsevier Inc. All rights reserved.

Thermosensitive liposomes: extravasation and release of contents in tumor microvascular networks.

PubMed

Gaber, M H; Wu, N Z; Hong, K; Huang, S K; Dewhirst, M W; Papahadjopoulos, D

1996-12-01

liposomes, but negligible release of Dox occurred when the window chamber was heated to 45 degrees C for 1 h. Extravasation of liposomes continued after heating was stopped, but content release stopped after removal of heat. Release of Dox from extravasated liposomes was also seen if heating was applied 24 h after liposome administration, but no further enhancement of liposome extravasation occurred in this case. Our data suggest that hyperthermia can be used to selectively enhance both the delivery and the rate of release of drugs from thermosensitive liposomes to targeted tissues.

Application of Liposomes in Treatment of Rheumatoid Arthritis: Quo Vadis

PubMed Central

Singh, Sachin Kumar; Gulati, Monica

2014-01-01

The most common treatments for rheumatoid arthritis include nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, disease modifying antirheumatic drugs (DMARDs), and some biological agents. However, none of the treatments available is able to achieve the ultimate goal of treatment, that is, drug-free remission. This limitation has shifted the focus of treatment to delivery strategies with an ability to deliver the drugs into the synovial cavity in the proper dosage while mitigating side effects to other tissues. A number of approaches like microemulsions, microspheres, liposomes, microballoons, cocrystals, nanoemulsions, dendrimers, microsponges, and so forth, have been used for intrasynovial delivery of these drugs. Amongst these, liposomes have proven to be very effective for retaining the drug in the synovial cavity by virtue of their size and chemical composition. The fast clearance of intra-synovially administered drugs can be overcome by use of liposomes leading to increased uptake of drugs by the target synovial cells, which in turn reduces the exposure of nontarget sites and eliminates most of the undesirable effects associated with therapy. This review focuses on the use of liposomes in treatment of rheumatoid arthritis and summarizes data relating to the liposome formulations of various drugs. It also discusses emerging trends of this promising technology. PMID:24688450

Development and Characterization of Liposomal Doxorubicin Hydrochloride with Palm Oil

PubMed Central

Sabeti, Bahareh; Noordin, Mohamed Ibrahim; Mohd, Shaharuddin; Hashim, Rosnani; Akbari Javar, Hamid

2014-01-01

The usage of natural products in pharmaceuticals has steadily seen improvements over the last decade, and this study focuses on the utilization of palm oil in formulating liposomal doxorubicin (Dox). The liposomal form of Dox generally minimizes toxicity and enhances target delivery actions. Taking into account the antiproliferative and antioxidant properties of palm oil, the aim of this study is to design and characterize a new liposomal Dox by replacing phosphatidylcholine with 5% and 10% palm oil content. Liposomes were formed using the freeze_thaw method, and Dox was loaded through pH gradient technique and characterized through in vitro and ex vivo terms. Based on TEM images, large lamellar vesicles (LUV) were formed, with sizes of 438 and 453 nm, having polydispersity index of 0.21 ± 0.8 and 0.22 ± 1.3 and zeta potentials of about −31 and −32 mV, respectively. In both formulations, the entrapment efficiency was about 99%, and whole Dox was released through 96 hours in PBS (pH = 7.4) at 37°C. Comparing cytotoxicity and cellular uptake of LUV with CaelyxR on MCF7 and MDA-MBA 231 breast cancer cell lines indicated suitable uptake and lower IC50 of the prepared liposomes. PMID:24795894

Involvement of let-7 microRNA for the therapeutic effects of Rhenium-188-embedded liposomal nanoparticles on orthotopic human head and neck cancer model.

PubMed

Lin, Liang-Ting; Chang, Chun-Yuan; Chang, Chih-Hsien; Wang, Hsin-Ell; Chiou, Shih-Hwa; Liu, Ren-Shyan; Lee, Te-Wei; Lee, Yi-Jang

2016-10-04

Human head and neck squamous cell carcinoma (HNSCC) is usually treated by surgical resection with adjuvant radio-chemotherapy. In this study, we examined whether the radiopharmaceutical 188Re-liposome could suppress the growth of HNSCC followed by an investigation of molecular mechanisms. The orthotopic HNSCC tumor model was established by human hypopharyngeal FaDu carcinoma cells harboring multiple reporter genes. The drug targeting and therapeutic efficacy of 188Re-liposome were examined using in vivo imaging, bio-distribution, pharmacokinetics, and dosimetry. The results showed that 188Re-liposome significantly accumulated in the tumor lesion compared to free 188Re. The circulation time and tumor targeting of 188Re-liposome were also longer than that of free 188Re in tumor-bearing mice. The tumor growth was suppressed by 188Re-liposome up to three weeks using a single dose treatment. Subsequently, microarray analysis followed by Ingenuity Pathway Analysis (IPA) showed that tumor suppressor let-7 microRNA could be an upstream regulator induced by 188Re-liposome to regulate downstream genes. Additionally, inhibition of let-7i could reduce the effects of 188Re-liposome on suppression of tumor growth, suggesting that let-7 family was involved in 188Re-liposome mediated suppression of tumor growth in vivo. Our data suggest that 188Re-liposome could be a novel strategy for targeting HNSCC partially via induction of let-7 microRNA.

[Effect of polyethylene glycol-lipid derivatives on the stability of grafted liposomes].

PubMed

Xu, Yang; Shi, Li; Deng, Yi-hui

2011-10-01

It is reported that polyethylene glycol-lipid (PEG-lipid) derivatives increase liposomes stability, prolong the blood circulation of liposomes, enhance their tumor-targeting efficiency, and improve drug efficacy. Therefore, it is of great importance to investigate the influence of modified PEG-lipid derivatives on the physical, chemical, and biological characteristics of liposomes for the promotion of dealing with the existed problems, such as the accelerated blood clearance (ABC) phenomenon when repeated intravous injection at a certain time-interval, and developing novel targeted pharmaceutical preparations. In this review, the effects of modified PEG-lipid derivatives were summarized in many aspects. It indicats that the chemical bonds (amide, ether, ester, and disulfide) between PEG and lipid, as well as the species of lipids, such as the commonly used phosphatidylethanolamine, cholesterol, and diacylglycerol have substantial effects on the grafted liposomes stability in vitro and in vivo. Besides, the properties of lipids (the fatty acid chain length and saturation) and the groups (methoxy, carboxylic and amino) at the distal ends of the PEG chains were also considered to be important factors. In the end, the influence of the average molecular weight of PEG and the molar ratio of PEG-lipid derivatives in the total lipid were further focused.

Ciprofloxacin as ocular liposomal hydrogel.

PubMed

Hosny, Khaled Mohamed

2010-03-01

The purpose of this study was to prepare and characterize an ocular effective prolonged-release liposomal hydrogel formulation containing ciprofloxacin. Reverse-phase evaporation was used for preparation of liposomes consisting of soybean phosphatidylcholine (PC) and cholesterol (CH). The effect of PC/CH molar ratio on the percentage drug encapsulation was investigated. The effect of additives such as stearylamine (SA) or dicetyl phosphate (DP) as positive and negative charge inducers, respectively, were studied. Morphology, mean size, encapsulation efficiency, and in vitro release of ciprofloxacin from liposomes were evaluated. For hydrogel preparation, Carbopol 940 was applied. In vitro transcorneal permeation through excised albino rabbit cornea was also determined. Optimal encapsulation efficiency of 73.04 +/- 3.06% was obtained from liposomes formulated with PC/CH at molar ratio of 5:3 and by increasing CH content above this limit, the encapsulation decreased. Positively charged liposomes showed superior entrapment efficiency (82.01 +/- 0.52) over the negatively charged and the neutral liposomes. Hydrogel containing liposomes with lipid content PC, CH, and SA in molar ratio 5:3:1, respectively, showed the best release and transcorneal permeation with the percentage permeation of 30.6%. These results suggest that the degree of encapsulation of ciprofloxacin into liposomes and prolonged in vitro release depend on composition of the vesicles. In addition, the polymer hydrogel used in preparation ensure steady and prolonged transcorneal permeation. In conclusion, ciprofloxacin liposomal hydrogel is a suitable delivery system for improving the ocular bioavailability of ciprofloxacin.

Decreased circulation time offsets increased efficacy of PEGylated nanocarriers targeting folate receptors of glioma

NASA Astrophysics Data System (ADS)

McNeeley, Kathleen M.; Annapragada, Ananth; Bellamkonda, Ravi V.

2007-09-01

Liposomal and other nanocarrier based drug delivery vehicles can localize to tumours through passive and/or active targeting. Passively targeted liposomal nanocarriers accumulate in tumours via 'leaky' vasculature through the enhanced permeability and retention (EPR) effect. Passive accumulation depends upon the circulation time and the degree of tumour vessel 'leakiness'. After extravasation, actively targeted liposomal nanocarriers efficiently deliver their payload by receptor-mediated uptake. However, incorporation of targeting moieties can compromise circulation time in the blood due to recognition and clearance by the reticuloendothelial system, decreasing passive accumulation. Here, we compare the efficacy of passively targeted doxorubicin-loaded PEGylated liposomal nanocarriers to that of actively targeted liposomal nanocarriers in a rat 9L brain tumour model. Although folate receptor (FR)-targeted liposomal nanocarriers had significantly reduced blood circulation time compared to PEGylated liposomal nanocarriers; intratumoural drug concentrations both at 20 and 50 h after administration were equal for both treatments. Both treatments significantly increased tumour inoculated animal survival by 60-80% compared to non-treated controls, but no difference in survival was observed between FR-targeted and passively targeted nanocarriers. Therefore, alternate approaches allowing for active targeting without compromising circulation time may be important for fully realizing the benefits of receptor-mediated active targeting of gliomas.

Capacious and programmable multi-liposomal carriers

NASA Astrophysics Data System (ADS)

Yaroslavov, Alexander A.; Sybachin, Andrey V.; Zaborova, Olga V.; Migulin, Vasiliy A.; Samoshin, Vyacheslav V.; Ballauff, Matthias; Kesselman, Ellina; Schmidt, Judith; Talmon, Yeshayahu; Menger, Fredric M.

2015-01-01

Spherical polycationic brushes (SPBs) were synthesized by grafting polycationic chains onto 100 nm polystyrene particles. These particles were exposed to unilamellar egg-lecithin (EL) liposomes with a mean diameter of 40 nm that had been rendered anionic via the presence of 10 molar% of phosphatidylserine (PS1-). The liposomes also contained 30 mole% of a morpholinocyclohexanol-based lipid (MOCH) that undergoes a conformational flip when the pH is decreased from 7.0 to 5.0. Mixtures of SPBs and liposomes at pH 7 gave an electrostatically-driven complex possessing, on average, about 40 liposomes for each SPB particle. It was found that the bound liposomes rapidly release much of their contents when the pH is reduced from 7.0 to 5.0 owing mostly to a MOCH conformational change that creates defects in the bilayer membrane. The drop in pH does not, however, induce a separation of the liposomes from the SPBs. Around 50-60% of the liposome contents escape before, it is reasoned, lateral and transmembrane motion of the membrane components heals the defects and prevents further release. Remarkably, the liposomes complexed with SPB release their cargo much faster than the identical but non-complexed liposomes.Spherical polycationic brushes (SPBs) were synthesized by grafting polycationic chains onto 100 nm polystyrene particles. These particles were exposed to unilamellar egg-lecithin (EL) liposomes with a mean diameter of 40 nm that had been rendered anionic via the presence of 10 molar% of phosphatidylserine (PS1-). The liposomes also contained 30 mole% of a morpholinocyclohexanol-based lipid (MOCH) that undergoes a conformational flip when the pH is decreased from 7.0 to 5.0. Mixtures of SPBs and liposomes at pH 7 gave an electrostatically-driven complex possessing, on average, about 40 liposomes for each SPB particle. It was found that the bound liposomes rapidly release much of their contents when the pH is reduced from 7.0 to 5.0 owing mostly to a MOCH conformational

Effective in vitro and in vivo gene delivery by the combination of liposomal bubbles (bubble liposomes) and ultrasound exposure.

PubMed

Suzuki, Ryo; Maruyama, Kazuo

2010-01-01

Gene delivery with a physical mechanism using ultrasound (US) and nano/microbubbles is expected as an ideal system in terms of delivering plasmid DNA noninvasively into a specific target site. We developed novel liposomal bubbles (Bubble liposomes (BLs)) containing the lipid nanobubbles of perfluoropropane which were utilized for contrast enhancement in ultrasonography. BLs were smaller in diameter than conventional microbubbles and induced cavitation upon exposure ultrasound. In addition, when coupled with US exposure, BLs could deliver plasmid DNA into various types of cells in vitro and in vivo. The transfection efficiency with BLs and US was higher than that with conventional lipofection method. Therefore, the combination of BLs and US might be an efficient and novel nonviral gene delivery system.

Comparison of Linear and Hyperbranched Polyether Lipids for Liposome Shielding by 18F-Radiolabeling and Positron Emission Tomography.

PubMed

Wagener, Karolin; Worm, Matthias; Pektor, Stefanie; Schinnerer, Meike; Thiermann, Raphael; Miederer, Matthias; Frey, Holger; Rösch, Frank

2018-04-27

Multifunctional and highly biocompatible polyether structures play a key role in shielding liposomes from degradation in the bloodstream, providing also multiple functional groups for further attachment of targeting moieties. In this work hyperbranched polyglycerol ( hbPG) bearing lipids with long alkyl chain anchor are evaluated with respect to steric stabilization of liposomes. The branched polyether lipids possess a hydrophobic bis(hexadecyl)glycerol membrane anchor for the liposomal membrane. hbPG was chosen as a multifunctional alternative to PEG, enabling the eventual linkage of multiple targeting vectors. Different hbPG lipids ( M n = 2900 and 5200 g mol -1 ) were examined. A linear bis(hexadecyl)glycerol-PEG lipid ( M n = 3000 g mol -1 ) was investigated as well, comparing hbPG and PEG with respect to shielding properties. Radiolabeling of the polymers was carried out using 1-azido-2-(2-(2-[ 18 F]fluoroethoxy)ethoxy)ethane ([ 18 F]F-TEG-N) 3 via copper-catalyzed alkyne-azide cycloaddition with excellent radiochemical yields exceeding 95%. Liposomes were prepared by the thin-film hydration method followed by repeated extrusion. Use of a custom automatic extrusion device gave access to reproducible sizes of the liposomes (hydrodynamic radius of 60-94 nm). The in vivo fate of the bis(hexadecyl)glycerol polyethers and their corresponding assembled liposome structures were evaluated via noninvasive small animal positron emission tomography (PET) imaging and biodistribution studies (1 h after injection and 4 h after injection) in mice. Whereas the main uptake of the nonliposomal polyether lipids was observed in the kidneys and in the bladder after 1 h due to rapid renal clearance, in contrast, the corresponding liposomes showed uptake in the blood pool as well as in organs with good blood supply, that is, heart and lung over the whole observation period of 4 h. The in vivo behavior of all three liposomal formulations was comparable, albeit with remarkable

Targeted delivery of epirubicin to tumor-associated macrophages by sialic acid-cholesterol conjugate modified liposomes with improved antitumor activity.

PubMed

Zhou, Songlei; Zhang, Ting; Peng, Bo; Luo, Xiang; Liu, Xinrong; Hu, Ling; Liu, Yang; Di, Donghua; Song, Yanzhi; Deng, Yihui

2017-05-15

With the knowledge that the receptors of sialic acid are overexpressed on the surface of tumor-associated macrophages (TAMs), which play a crucial role in the tumor's progression and metastasis, a sialic acid-cholesterol conjugate (SA-CH) was synthesized and modified on the surface of epirubicin (EPI)-loaded liposomes (EPI-SAL) to improve the delivery of EPI to the TAMs. The liposomes were developed using remote loading technology via a pH gradient. The liposomes were evaluated for particle size, encapsulation efficiency, in vitro release, stability, in vitro cytotoxicity and pharmacokinetics. And the in vitro and in vivo cellular uptake studies demonstrated EPI-SAL achieved enhanced accumulation of EPI into TAMs. The antitumor studies indicated that EPI-SAL provided the strongest antitumor activity compared with the other formulations (EPI-S, EPI-CL and EPI-PL represent EPI solution, conventional liposomal EPI, PEGylated liposomal EPI, respectively), and the survival percent of tumor-bearing mice was 83.3%. The superior antitumor efficacy was probably attributed to the killing of TAMs by EPI-SAL, and modulating the tumor microenvironment with the depletion of TAMs. These findings suggested that SA-CH decorated EPI-loaded liposomes may present an effective strategy to eradicate TAMs, which may be a promising approach for cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

pH-sensitive liposomes: characterization and application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Connor, J.

1986-01-01

It has been demonstrated that liposomes composed of dioleoylphosphatidylethanolamine (DOPE) and palmitoylhomocysteine (PHC) have the ability to fuse with adjacent membranes upon exposure to mildly acid pH. The ability of liposomes to fuse is absolutely dependent on the presence of DOPE and a weakly acidic amphiphile. The acid induced fusion event is a leaky process, but the leakage can be reduced by 50%, with only a small loss of fusion ability, by the inclusion of 40 mole percent cholesterol. Using an established monoclonal antibody targeting system. pH-sensitive immunoliposomes were prepared which successfully delivered entrapped calcein to the cytoplasm of targetmore » cells. The addition of chloroquine, which raises the internal pH of cellular vacuoles, blocks the cytoplasmic delivery of the pH-sensitive immunoliposomes. pH-insensitive immunoliposomes delivered calcein only to the endosome/lysosome system and not the cytoplasm. /sup 31/P-NMR and light scattering of DOPE:OA liposomes under acidic conditions demonstrate that the effect of the protons and the divalent cations is to force the DOPE to revert to the hexagonal II configuration. In vivo experiments with DOPE:OA immunoliposomes indicate that the liposomes rapidly aggregate and release their contents upon exposure to plasma. These results indicate that pH-sensitive immunoliposomes are an effective tool for in vitro cytoplasmic delivery but are ineffective for in vivo delivery at this point in development.« less

New drug candidates for liposomal delivery identified by computer modeling of liposomes' remote loading and leakage.

PubMed

Cern, Ahuva; Marcus, David; Tropsha, Alexander; Barenholz, Yechezkel; Goldblum, Amiram

2017-04-28

Remote drug loading into nano-liposomes is in most cases the best method for achieving high concentrations of active pharmaceutical ingredients (API) per nano-liposome that enable therapeutically viable API-loaded nano-liposomes, referred to as nano-drugs. This approach also enables controlled drug release. Recently, we constructed computational models to identify APIs that can achieve the desired high concentrations in nano-liposomes by remote loading. While those previous models included a broad spectrum of experimental conditions and dealt only with loading, here we reduced the scope to the molecular characteristics alone. We model and predict API suitability for nano-liposomal delivery by fixing the main experimental conditions: liposome lipid composition and size to be similar to those of Doxil® liposomes. On that basis, we add a prediction of drug leakage from the nano-liposomes during storage. The latter is critical for having pharmaceutically viable nano-drugs. The "load and leak" models were used to screen two large molecular databases in search of candidate APIs for delivery by nano-liposomes. The distribution of positive instances in both loading and leakage models was similar in the two databases screened. The screening process identified 667 molecules that were positives by both loading and leakage models (i.e., both high-loading and stable). Among them, 318 molecules received a high score in both properties and of these, 67 are FDA-approved drugs. This group of molecules, having diverse pharmacological activities, may be the basis for future liposomal drug development. Copyright © 2017 Elsevier B.V. All rights reserved.

Involvement of let-7 microRNA for the therapeutic effects of Rhenium-188-embedded liposomal nanoparticles on orthotopic human head and neck cancer model

PubMed Central

Lin, Liang-Ting; Chang, Chun-Yuan; Chang, Chih-Hsien; Wang, Hsin-Ell; Chiou, Shih-Hwa; Liu, Ren-Shyan; Lee, Te-Wei; Lee, Yi-Jang

2016-01-01

Human head and neck squamous cell carcinoma (HNSCC) is usually treated by surgical resection with adjuvant radio-chemotherapy. In this study, we examined whether the radiopharmaceutical 188Re-liposome could suppress the growth of HNSCC followed by an investigation of molecular mechanisms. The orthotopic HNSCC tumor model was established by human hypopharyngeal FaDu carcinoma cells harboring multiple reporter genes. The drug targeting and therapeutic efficacy of 188Re-liposome were examined using in vivo imaging, bio-distribution, pharmacokinetics, and dosimetry. The results showed that 188Re-liposome significantly accumulated in the tumor lesion compared to free 188Re. The circulation time and tumor targeting of 188Re-liposome were also longer than that of free 188Re in tumor-bearing mice. The tumor growth was suppressed by 188Re-liposome up to three weeks using a single dose treatment. Subsequently, microarray analysis followed by Ingenuity Pathway Analysis (IPA) showed that tumor suppressor let-7 microRNA could be an upstream regulator induced by 188Re-liposome to regulate downstream genes. Additionally, inhibition of let-7i could reduce the effects of 188Re-liposome on suppression of tumor growth, suggesting that let-7 family was involved in 188Re-liposome mediated suppression of tumor growth in vivo. Our data suggest that 188Re-liposome could be a novel strategy for targeting HNSCC partially via induction of let-7 microRNA. PMID:27588466

Cellular Engineering with Membrane Fusogenic Liposomes to Produce Functionalized Extracellular Vesicles.

PubMed

Lee, Junsung; Lee, Hyoungjin; Goh, Unbyeol; Kim, Jiyoung; Jeong, Moonkyoung; Lee, Jean; Park, Ji-Ho

2016-03-23

Engineering of extracellular vesicles (EVs) without affecting biological functions remains a challenge, limiting the broad applications of EVs in biomedicine. Here, we report a method to equip EVs with various functional agents, including fluorophores, drugs, lipids, and bio-orthogonal chemicals, in an efficient and controlled manner by engineering parental cells with membrane fusogenic liposomes, while keeping the EVs intact. As a demonstration of how this method can be applied, we prepared EVs containing azide-lipids, and conjugated them with targeting peptides using copper-free click chemistry to enhance targeting efficacy to cancer cells. We believe that this liposome-based cellular engineering method will find utility in studying the biological roles of EVs and delivering therapeutic agents through their innate pathway.

PLGA nanoparticles introduction into mitoxantrone-loaded ultrasound-responsive liposomes: In vitro and in vivo investigations.

PubMed

Xin, Yuxuan; Qi, Qi; Mao, Zhenmin; Zhan, Xiaoping

2017-08-07

A novel ultrasound-responsive liposomal system for tumor targeting was prepared in order to increase the antitumor efficacy and decrease serious side effects. In this paper, PLGA nanoparticles were used ultrasound-responsive agents instead of conventional microbubbles. The PLGA-nanoparticles were prepared by an emulsion solvent evaporation method. The liposomes were prepared by a lipid film hydration method. Particle size, zeta potential, encapsulation efficiency and drug loading capacity of the liposomes were studied by light scattering analysis and dialysis. Transmission electron microscopy (TEM) and atomic force microscope (AFM) were used to investigate the morphology of liposomes. The release in vitro was carried out in the pH 7.4 phosphate buffer solutions, as a result, liposome L3 encapsulating PLGA-nanoparticles displayed good stability under simulative physiological conditions and quickly responsive release under the ultrasound. The release in vivo was carried out on the rats, as a result, liposome L3 showed higher bioavailability than traditional intravenous injectable administration, and liposome L3 showed higher elimination ratio after stimulation by ultrasound than L3 without stimulation. Thus, the novel ultrasound-responsive liposome encapsulating PLGA-nanoparticles has a potential to be developed as a new drug delivery system for anti-tumor drug. Copyright © 2017 Elsevier B.V. All rights reserved.

Liposomalization of oxaliplatin induces skin accumulation of it, but negligible skin toxicity.

PubMed

Nishida, Kentaro; Kashiwagi, Misaki; Shiba, Shunsuke; Muroki, Kiwamu; Ohishi, Akihiro; Doi, Yusuke; Ando, Hidenori; Ishida, Tatsuhiro; Nagasawa, Kazuki

2017-12-15

Liposomalization causes alteration of the pharmacokinetics of encapsulated drugs, and allows delivery to tumor tissues through passive targeting via an enhanced permeation and retention (EPR) effect. PEGylated liposomal doxorubicin (Doxil ® , Lipo-DXR), a representative liposomal drug, is well-known to reduce cardiotoxicity and increase the anti-tumor activity of DXR, but to induce the hand-foot syndrome (HFS) as a result of skin DXR accumulation, which is one of its severe adverse effects. We have developed a new liposomal preparation of oxaliplatin (l-OHP), an important anti-tumor drug for treatment of colorectal cancer, using PEGylated liposomes (Lipo-l-OHP), and showed that Lipo-l-OHP exhibits increased anti-tumor activity in tumor-bearing mice compared to the original preparation of l-OHP. However, whether Lipo-l-OHP causes HFS-like skin toxicity similar to Lipo-DXR remains to be determined. Administration of Lipo-l-OHP promoted accumulation of platinum in rat hind paws, however, it caused negligible morphological and histological alterations on the plantar surface of the paws. Administration of DiI-labeled empty PEGylated liposomes gave almost the same distribution profile of dyes into the dermis of hind paws with DXR as in the case of Lipo-DXR. Treatment with Lipo-l-OHP, Lipo-DXR, DiI-labeled empty PEGylated liposomes or empty PEGylated liposomes caused migration of CD68 + macrophages into the dermis of hind paws. These findings suggest that the skin toxicity on administration of liposomalized drugs is reflected in the proinflammatory characteristics of encapsulated drugs, and indicate that Lipo-l-OHP with a higher anti-cancer effect and no HFS may be an outstanding l-OHP preparation leading to an improved quality of life of cancer patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Nanoparticle Stabilized Liposomes for Acne Therapy

NASA Astrophysics Data System (ADS)

Fu, Victoria

Acne vulgaris is a common skin disease that affects over 40 million people in the United States alone. The main cause of acne vulgaris is Propionibacterium acnes (P. acnes), resides deep in the pores and follicles of the skin in order to feed on oil produced by the sebaceous glands. The liposome is a lipid based nanoparticle with numerous advantages over free drug molecules as an acne treatment alternative. Bare liposomes loaded with lauric acid (LipoLA) were found to show strong antimicrobial activity against P. acnes while generating minimal toxicity. However, the platform is limited by the spontaneous tendency of liposomes to fuse with each other. Attaching nanoparticles to the surface of liposomes can overcome this challenge by providing steric repulsion and reduce surface tension. Thus, carboxyl-functionalized gold nanoparticles (AuC) were attached to the surface of liposomes (AuC-liposomes) loaded with doxycycline, a general tetracycline antibiotic. These particles were found to have a diameter of 120 nm and a zeta potential of 20.0 mV. Both fluorescent and antimicrobial studies demonstrated that based on electrostatic interaction, negatively charged AuC attached to the liposome's positively charged surface and stabilized liposomes in a neutral pH environment (pH = 7.4). Upon entering the skin's acidic environment (pH = 4), AuC detached from the liposome's surface and liposomes could fuse with P. acnes residing in the pores. Furthermore, toxicity studies showed that AuC-liposomes did not induce any significant toxicity, while two of the leading over-the-counter therapies, benzoyl peroxide and salicylic acid, generated substantial skin irritation.

Gd(III)-DOTA-modified sonosensitive liposomes for ultrasound-triggered release and MR imaging

NASA Astrophysics Data System (ADS)

Jung, Suk Hyun; Na, Kyunga; Lee, Seul A.; Cho, Sun Hang; Seong, Hasoo; Shin, Byung Cheol

2012-08-01

Ultrasound-sensitive (sonosensitive) liposomes for tumor targeting have been studied in order to increase the antitumor efficacy of drugs and decrease the associated severe side effects. Liposomal contrast agents having Gd(III) are known as a nano-contrast agent system for the efficient and selective delivery of contrast agents into pathological sites. The objective of this study was to prepare Gd(III)-DOTA-modified sonosensitive liposomes (GdSL), which could deliver a model drug, doxorubicin (DOX), to a specific site and, at the same time, be capable of magnetic resonance (MR) imaging. The GdSL was prepared using synthesized Gd(III)-DOTA-1,2-distearoyl- sn-glycero-3-phosphoethanolamine lipid. Sonosensitivity of GdSL to 20-kHz ultrasound induced 33% to 40% of DOX release. The relaxivities ( r 1) of GdSL were 6.6 to 7.8 mM-1 s-1, which were higher than that of MR-bester®. Intracellular uptake properties of GdSL were evaluated according to the intensity of ultrasound. Intracellular uptake of DOX for ultrasound-triggered GdSL was higher than that for non-ultrasound-triggered GdSL. The results of our study suggest that the paramagnetic and sonosensitive liposomes, GdSL, may provide a versatile platform for molecular imaging and targeted drug delivery.

HEPC-based liposomes trigger cytokine release from peripheral blood cells: effects of liposomal size, dose and lipid composition.

PubMed

Yamamoto, Sayaka; Ishida, Tatsuhiro; Inoue, Akiko; Mikami, Junko; Muraguchi, Masahiro; Ohmoto, Yasukazu; Kiwada, Hiroshi

2002-04-02

The immune response caused by liposome stimulation was studied by assessing the level of several cytokines released from human peripheral blood cells. Liposome stimulation resulted in the release of IL-6, IL-10, IL-1beta, TNF-alpha and IFN-gamma. The size of the liposomes affected the degree of the cytokine releases with larger sized liposomes causing higher levels of cytokine induction. In addition, it appears that the lipid composition of liposomes had no effect on the degree of cytokine release. The release of cytokines occurred even in the absence of serum, suggesting that serum proteins did not contribute to liposome stimulation in peripheral blood cells. The release of cytokines induced by liposome stimulation was inhibited by the presence of either protein kinase-C (PKC) or protein tyrosine kinase (PTK) inhibitor, but not by the presence of an endocytosis inhibitor. This indicates that signal transduction via PKC or PTK is necessary, in order for human peripheral blood cells to release cytokines (IL-6, IL-10, IL-1beta, TNF-alpha and IFN-gamma) as the result of liposome stimulation. These quantitative data on the release of cytokines by liposomal stimulation provide useful information for the development of rational drug delivery systems and the safety of cytokine induction via the use of liposomes.

Estrogen-anchored pH-sensitive liposomes as nanomodule designed for site-specific delivery of doxorubicin in breast cancer therapy.

PubMed

Paliwal, Shivani R; Paliwal, Rishi; Pal, Harish C; Saxena, Ajeet K; Sharma, Pradyumana R; Gupta, Prem N; Agrawal, Govind P; Vyas, Suresh P

2012-01-01

The present investigation reports the development of nanoengineered estrogen receptor (ER) targeted pH-sensitive liposome for the site-specific intracellular delivery of doxorubicin (DOX) for breast cancer therapy. Estrone, a bioligand, was anchored on the surface of pH-sensitive liposome for drug targeting to ERs. The estrone-anchored pH-sensitive liposomes (ES-pH-sensitive-SL) showed fusogenic potential at acidic pH (5.5). In vitro cytotoxicity studies carried out on ER-positive MCF-7 breast carcinoma cells revealed that ES-pH-sensitive-SL formulation was more cytotoxic than non-pH-sensitive targeted liposomes (ES-SL). The flow cytometry analysis confirmed significant enhanced uptake (p < 0.05) of ES-pH-sensitive-SL by MCF-7 cells. Intracellular delivery and nuclear localization of the DOX was confirmed by fluorescence microscopy. The mechanism for higher cytotoxicity shown by estrone-anchored pH-sensitive liposomal-DOX was elucidated using reactive oxygen species (ROS) determination. The in vivo biodistribution studies and antitumor activities of formulations were evaluated on tumor bearing female Balb/c mice followed by intravenous administration. The ES-pH-sensitive-SL efficiently suppressed the breast tumor growth in comparison to both ES-SL and free DOX. Serum enzyme activities such as LDH and CPK levels were assayed for the evaluation of DOX induced cardiotoxicity. The ES-pH-sensitive-SL accelerated the intracellular trafficking of encapsulated DOX, thus increasing the therapeutic efficacy. The findings support that estrone-anchored pH-sensitive liposomes could be one of the promising nanocarriers for the targeted intracellular delivery of anticancer agents to breast cancer with reduced systemic side effects.

Quantification of ligand density and stoichiometry on the surface of liposomes using single-molecule fluorescence imaging.

PubMed

Belfiore, Lisa; Spenkelink, Lisanne M; Ranson, Marie; van Oijen, Antoine M; Vine, Kara L

2018-05-28

Despite the longstanding existence of liposome technology in drug delivery applications, there have been no ligand-directed liposome formulations approved for clinical use to date. This lack of translation is due to several factors, one of which is the absence of molecular tools for the robust quantification of ligand density on the surface of liposomes. We report here for the first time the quantification of proteins attached to the surface of small unilamellar liposomes using single-molecule fluorescence imaging. Liposomes were surface-functionalized with fluorescently labeled human proteins previously validated to target the cancer cell surface biomarkers plasminogen activator inhibitor-2 (PAI-2) and trastuzumab (TZ, Herceptin®). These protein-conjugated liposomes were visualized using a custom-built wide-field fluorescence microscope with single-molecule sensitivity. By counting the photobleaching steps of the fluorescently labeled proteins, we calculated the number of attached proteins per liposome, which was 11 ± 4 proteins for single-ligand liposomes. Imaging of dual-ligand liposomes revealed stoichiometries of the two attached proteins in accordance with the molar ratios of protein added during preparation. Preparation of PAI-2/TZ dual-ligand liposomes via two different methods revealed that the post-insertion method generated liposomes with a more equal representation of the two differently sized proteins, demonstrating the ability of this preparation method to enable better control of liposome protein densities. We conclude that the single-molecule imaging method presented here is an accurate and reliable quantification tool for determining ligand density and stoichiometry on the surface of liposomes. This method has the potential to allow for comprehensive characterization of novel ligand-directed liposomes that should facilitate the translation of these nanotherapies through to the clinic. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhanced bactericidal potency of nanoliposomes by modification of the fusion activity between liposomes and bacterium.

PubMed

Ma, Yufan; Wang, Zhao; Zhao, Wen; Lu, Tingli; Wang, Rutao; Mei, Qibing; Chen, Tao

2013-01-01

Pseudomonas aeruginosa represents a good model of antibiotic resistance. These organisms have an outer membrane with a low level of permeability to drugs that is often combined with multidrug efflux pumps, enzymatic inactivation of the drug, or alteration of its molecular target. The acute and growing problem of antibiotic resistance of Pseudomonas to conventional antibiotics made it imperative to develop new liposome formulations to overcome these mechanisms, and investigate the fusion between liposome and bacterium. The rigidity, stability and charge properties of phospholipid vesicles were modified by varying the cholesterol, 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE), and negatively charged lipids 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol sodium salt (DMPG), 1,2-dimyristoyl-sn-glycero-3-phopho-L-serine sodium salt (DMPS), 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt (DMPA), nature phosphatidylserine sodium salt from brain and nature phosphatidylinositol sodium salt from soybean concentrations in liposomes. Liposomal fusion with intact bacteria was monitored using a lipid-mixing assay. It was discovered that the fluid liposomes-bacterium fusion is not dependent on liposomal size and lamellarity. A similar degree of fusion was observed for liposomes with a particle size from 100 to 800 nm. The fluidity of liposomes is an essential pre-request for liposomes fusion with bacteria. Fusion was almost completely inhibited by incorporation of cholesterol into fluid liposomes. The increase in the amount of negative charges in fluid liposomes reduces fluid liposomes-bacteria fusion when tested without calcium cations due to electric repulsion, but addition of calcium cations brings the fusion level of fluid liposomes to similar or higher levels. Among the negative phospholipids examined, DMPA gave the highest degree of fusion, DMPS and DMPG had intermediate fusion levels, and PI resulted in the lowest degree of fusion. Furthermore, the fluid

Enhanced bactericidal potency of nanoliposomes by modification of the fusion activity between liposomes and bacterium

PubMed Central

Ma, Yufan; Wang, Zhao; Zhao, Wen; Lu, Tingli; Wang, Rutao; Mei, Qibing; Chen, Tao

2013-01-01

Background Pseudomonas aeruginosa represents a good model of antibiotic resistance. These organisms have an outer membrane with a low level of permeability to drugs that is often combined with multidrug efflux pumps, enzymatic inactivation of the drug, or alteration of its molecular target. The acute and growing problem of antibiotic resistance of Pseudomonas to conventional antibiotics made it imperative to develop new liposome formulations to overcome these mechanisms, and investigate the fusion between liposome and bacterium. Methods The rigidity, stability and charge properties of phospholipid vesicles were modified by varying the cholesterol, 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE), and negatively charged lipids 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol sodium salt (DMPG), 1,2-dimyristoyl-sn-glycero-3-phopho-L-serine sodium salt (DMPS), 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt (DMPA), nature phosphatidylserine sodium salt from brain and nature phosphatidylinositol sodium salt from soybean concentrations in liposomes. Liposomal fusion with intact bacteria was monitored using a lipid-mixing assay. Results It was discovered that the fluid liposomes-bacterium fusion is not dependent on liposomal size and lamellarity. A similar degree of fusion was observed for liposomes with a particle size from 100 to 800 nm. The fluidity of liposomes is an essential pre-request for liposomes fusion with bacteria. Fusion was almost completely inhibited by incorporation of cholesterol into fluid liposomes. The increase in the amount of negative charges in fluid liposomes reduces fluid liposomes-bacteria fusion when tested without calcium cations due to electric repulsion, but addition of calcium cations brings the fusion level of fluid liposomes to similar or higher levels. Among the negative phospholipids examined, DMPA gave the highest degree of fusion, DMPS and DMPG had intermediate fusion levels, and PI resulted in the lowest degree of fusion

Liposomal membrane disruption by means of miniaturized dielectric-barrier discharge in air: liposome characterization

NASA Astrophysics Data System (ADS)

Svarnas, P.; Asimakoulas, L.; Katsafadou, M.; Pachis, K.; Kostazos, N.; Antimisiaris, S. G.

2017-08-01

The increasing interest of the plasma community in the application of atmospheric-pressure cold plasmas to bio-specimen treatment has led to the creation of the emerging field of plasma biomedicine. Accordingly, plasma setups based on dielectric-barrier discharges have already been widely tested for the inactivation of various cells. Most of these systems refer to the plasma jet concept where noble gases penetrate atmospheric air and are subjected to the influence of high electric fields, thus forming guided streamers. Following the original works of our group where liposomal membranes were proposed as models for studying the interaction between plasma jets and cells, we present herein a study on liposomal membrane disruption by means of miniaturized dielectric-barrier discharge running in atmospheric air. Liposomal membranes of various lipid compositions, lamellarities, and sizes are treated at different times. It is shown that the dielectric-barrier discharge of low mean power leads to efficient liposomal membrane disruption. The latter is achieved in a controllable manner and depends on liposome properties. Additionally, it is clearly demonstrated that liposomal membrane disruption takes place even after plasma extinction, i.e. during post-treatment, resembling thus an ‘apoptosis’ effect, which is well known today mainly for cell membranes. Thus, the adoption of the present concept would be beneficial for tailoring studies on plasma-treated cell-mimics. Finally, the liposome treatment is discussed with respect to possible physicochemical mechanisms and potential discharge modification due to the various compositions of the liquid electrode.

T1 relaxivity of core-encapsulated gadolinium liposomal contrast agents--effect of liposome size and internal gadolinium concentration.

PubMed

Ghaghada, Ketan; Hawley, Catherine; Kawaji, Keigo; Annapragada, Ananth; Mukundan, Srinivasan

2008-10-01

Long circulating core-encapsulated gadolinium (CE-Gd) liposomal nanoparticles that have surface conjugated polyethylene glycol are a promising platform technology for use as blood pool T1-based magnetic resonance (MR) contrast agents. The objective of this study was to investigate the effect of liposome size and internal (core) Gd concentration on the T1 relaxivity of CE-Gd liposomes. Twelve different liposomal formulations were synthesized and characterized, resulting in a size (50, 100, 200, and 400 nm) and core Gd-concentration (200, 350, and 500 mM) "matrix" of test samples. Subsequently, CE-Gd liposomes were diluted in deionized water (four diluted samples) and molar T1 relaxivity (r1) measurements were performed at 2- and 7-T MR field strengths. The r1 of CE-Gd liposomes was inversely related to the liposome size. The largest change in r1 was observed between liposomes that were extruded through 50- and 100-nm filter membranes. At both field strengths, the variation in internal gadolinium concentration did not show any significant correlation (alpha < or = 0.05) with r1. The size of CE-Gd liposomal nanoparticles significantly affects the T1 relaxivity. An inverse relation was observed between liposome size and T1 relaxivity. The T1 relaxivity did not change significantly with core Gd concentration over the measured concentration range.

Targeted Delivery of CRISPR/Cas9-Mediated Cancer Gene Therapy via Liposome-Templated Hydrogel Nanoparticles.

PubMed

Chen, Zeming; Liu, Fuyao; Chen, Yanke; Liu, Jun; Wang, Xiaoying; Chen, Ann T; Deng, Gang; Zhang, Hongyi; Liu, Jie; Hong, Zhangyong; Zhou, Jiangbing

2017-12-08

Due to its simplicity, versatility, and high efficiency, the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 technology has emerged as one of the most promising approaches for treatment of a variety of genetic diseases, including human cancers. However, further translation of CRISPR/Cas9 for cancer gene therapy requires development of safe approaches for efficient, highly specific delivery of both Cas9 and single guide RNA to tumors. Here, novel core-shell nanostructure, liposome-templated hydrogel nanoparticles (LHNPs) that are optimized for efficient codelivery of Cas9 protein and nucleic acids is reported. It is demonstrated that, when coupled with the minicircle DNA technology, LHNPs deliver CRISPR/Cas9 with efficiency greater than commercial agent Lipofectamine 2000 in cell culture and can be engineered for targeted inhibition of genes in tumors, including tumors the brain. When CRISPR/Cas9 targeting a model therapeutic gene, polo-like kinase 1 (PLK1), is delivered, LHNPs effectively inhibit tumor growth and improve tumor-bearing mouse survival. The results suggest LHNPs as versatile CRISPR/Cas9-delivery tool that can be adapted for experimentally studying the biology of cancer as well as for clinically translating cancer gene therapy.

The functional curcumin liposomes induce apoptosis in C6 glioblastoma cells and C6 glioblastoma stem cells in vitro and in animals.

PubMed

Wang, Yahua; Ying, Xue; Xu, Haolun; Yan, Helu; Li, Xia; Tang, Hui

2017-01-01

Glioblastoma is a kind of malignant gliomas that is almost impossible to cure due to the poor drug transportation across the blood-brain barrier and the existence of glioma stem cells. We prepared a new kind of targeted liposomes in order to improve the drug delivery system onto the glioma cells and induce the apoptosis of glioma stem cells afterward. In this experiment, curcumin was chosen to kill gliomas, while quinacrine was used to induce apoptosis of the glioma stem cells. Also, p -aminophenyl-α-D-mannopyranoside could facilitate the transport of liposomes across the blood-brain barrier and finally target the brain glioma cells. The cell experiments in vitro indicated that the targeted liposomes could significantly improve the anti-tumor effects of the drugs, while enhancing the uptake effects, apoptosis effects, and endocytic effects of C6 glioma cells and C6 glioma stem cells. Given the animal experiments in vivo, we discovered that the targeted liposomes could obviously increase the survival period of brain glioma-bearing mice and inhibit the growth of gliomas. In summary, curcumin and quinacrine liposomes modified with p -aminophenyl-α-D-mannopyranoside is a potential preparation to treat brain glioma cells and brain glioma stem cells.

The functional curcumin liposomes induce apoptosis in C6 glioblastoma cells and C6 glioblastoma stem cells in vitro and in animals

PubMed Central

Wang, Yahua; Ying, Xue; Xu, Haolun; Yan, Helu; Li, Xia; Tang, Hui

2017-01-01

Glioblastoma is a kind of malignant gliomas that is almost impossible to cure due to the poor drug transportation across the blood–brain barrier and the existence of glioma stem cells. We prepared a new kind of targeted liposomes in order to improve the drug delivery system onto the glioma cells and induce the apoptosis of glioma stem cells afterward. In this experiment, curcumin was chosen to kill gliomas, while quinacrine was used to induce apoptosis of the glioma stem cells. Also, p-aminophenyl-α-D-mannopyranoside could facilitate the transport of liposomes across the blood–brain barrier and finally target the brain glioma cells. The cell experiments in vitro indicated that the targeted liposomes could significantly improve the anti-tumor effects of the drugs, while enhancing the uptake effects, apoptosis effects, and endocytic effects of C6 glioma cells and C6 glioma stem cells. Given the animal experiments in vivo, we discovered that the targeted liposomes could obviously increase the survival period of brain glioma-bearing mice and inhibit the growth of gliomas. In summary, curcumin and quinacrine liposomes modified with p-aminophenyl-α-D-mannopyranoside is a potential preparation to treat brain glioma cells and brain glioma stem cells. PMID:28260885

Liposome retention in size exclusion chromatography

PubMed Central

Ruysschaert, Tristan; Marque, Audrey; Duteyrat, Jean-Luc; Lesieur, Sylviane; Winterhalter, Mathias; Fournier, Didier

2005-01-01

Background Size exclusion chromatography is the method of choice for separating free from liposome-encapsulated molecules. However, if the column is not presaturated with lipids this type of chromatography causes a significant loss of lipid material. To date, the mechanism of lipid retention is poorly understood. It has been speculated that lipid binds to the column material or the entire liposome is entrapped inside the void. Results Here we show that intact liposomes and their contents are retained in the exclusion gel. Retention depends on the pore size, the smaller the pores, the higher the retention. Retained liposomes are not tightly fixed to the beads and are slowly released from the gels upon direct or inverted eluent flow, long washing steps or column repacking. Further addition of free liposomes leads to the elution of part of the gel-trapped liposomes, showing that the retention is transitory. Trapping reversibility should be related to a mechanism of partitioning of the liposomes between the stationary phase, water-swelled polymeric gel, and the mobile aqueous phase. Conclusion Retention of liposomes by size exclusion gels is a dynamic and reversible process, which should be accounted for to control lipid loss and sample contamination during chromatography. PMID:15885140

Tumor Burden Talks in Cancer Treatment with PEGylated Liposomal Drugs

PubMed Central

Li, Jia-Je; Hwang, Jeng-Jong; Tseng, Yun-Long; Lin, Wuu-Jyh; Lin, Ming-Hsien; Ting, Gann; Wang, Hsin-Ell

2013-01-01

Purpose PEGylated liposomes are important drug carriers that can passively target tumor by enhanced permeability and retention (EPR) effect in neoplasm lesions. This study demonstrated that tumor burden determines the tumor uptake, and also the tumor response, in cancer treatment with PEGylated liposomal drugs in a C26/tk-luc colon carcinoma-bearing mouse model. Methods Empty PEGylated liposomes (NanoX) and those encapsulated with VNB (NanoVNB) were labeled with In-111 to obtain InNanoX and InVNBL in high labeling yield and radiochemical purity (all >90%). BALB/c mice bearing either small (58.4±8.0 mm3) or large (102.4±22.0 mm3) C26/tk-luc tumors in the right dorsal flank were intravenously administered with NanoVNB, InNanoX, InVNBL, or NanoX as a control, every 7 days for 3 times. The therapeutic efficacy was evaluated by body weight loss, tumor growth inhibition (using calipers and bioluminescence imaging) and survival fraction. The scintigraphic imaging of tumor mouse was performed during and after treatment. Results The biodistribution study of InVNBL revealed a clear inverse correlation (r 2 = 0.9336) between the tumor uptake and the tumor mass ranged from 27.6 to 623.9 mg. All three liposomal drugs showed better therapeutic efficacy in small-tumor mice than in large-tumor mice. Tumor-bearing mice treated with InVNBL (a combination drug) showed the highest tumor growth inhibition rate and survival fraction compared to those treated with NanoVNB (chemodrug only) and InNanoX (radionuclide only). Specific tumor targeting and significantly increased tumor uptake after periodical treatment with InVNBL were evidenced by scintigraphic imaging, especially in mice bearing small tumors. Conclusion The significant differences in the outcomes of cancer treatment and molecular imaging between animals bearing small and large tumors revealed that tumor burden is a critical and discriminative factor in cancer therapy using PEGylated liposomal drugs. PMID:23675454

Biocompatibility and light transmission of liposomal lenses.

PubMed

Danion, Anne; Doillon, Charles J; Giasson, Claude J; Djouahra, Saliha; Sauvageau, Patrick; Paradis, Renée; Vermette, Patrick

2007-10-01

To validate the biocompatibility and transmittance properties of contact lenses bearing intact liposomes. These liposomal lenses loaded with therapeutics can be used as ophthalmic drug delivery systems. The biocompatibility of soft contact lenses, coated with liposomes was evaluated through in vitro direct and indirect cytocompatibility assays on human corneal epithelial cells, on reconstructed human corneas and on ex vivo rabbit corneas. The direct and indirect transmission spectra of liposome-covered lenses were also evaluated to test if they transmit all wavelengths of the ultraviolet-visible spectrum, to thereby fulfill their optical function, without gross alteration of the colors perception and with a minimum of light dispersion. Contact lenses bearing layers of stable liposomes did not induce any significant changes in cell viability and in cell growth, compared with lenses bearing no liposome. Elution assays revealed that no cytotoxic compound leaks from the lenses whether bearing liposomes or not. Histological analyses of reconstructed human corneas and ex vivo rabbit corneas directly exposed to liposomal lenses revealed neither alteration to the cell nor to the tissue structures. Contact lenses bearing layers of liposomes did not significantly affect light transmission compared with control lenses without liposome at the wavelength of maximal photopic sensitivity, i.e., 550 nm. In addition, the contact lenses afford more eye protection in the ultraviolet spectrum, compared with the control lenses. Liposomal contact lenses are biocompatible and their transmittance properties are not affected in the visible light range.

Liposomes as carriers of macrolides: preferential association of erythromycin A and azithromycin with liposomes of phosphatidylglycerol containing unsaturated fatty acid(s).

PubMed

Stuhne-Sekalec, L; Stanacev, N Z; Djokic, S

1991-01-01

To assess the most favourable phospholipid composition of a liposomal carrier for antibiotics, small multilamellar liposomes were prepared from phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol of varying fatty acid composition in the presence of erythromycin A and azithromycin. Crude liposomes were subjected to Sepharose CL-4B column chromatography, and liposomes containing antibiotics were well separated from free antibiotics. These experiments established that the greatest association of antibiotics was achieved with liposomes prepared from phosphatidylglycerol rather than phosphatidylcholine or phosphatidylethanolamine. Furthermore, the composition of fatty acids in phosphatidylglycerol liposomes influenced the amount of antibiotics associated with liposomes; the highest amount was obtained with dioleoylphosphatidylglycerol followed by phosphatidylglycerol of fatty acid composition similar to that of egg yolk lecithin. It was established that purified liposomes, prepared from [3H]phosphatidylglycerol containing unsaturated fatty acid(s) bind about 25 per cent of originally present antibiotic. Both antibiotics, erythromycin A and azithromycin, were similar in respect to the amount of their association with liposomes. Determination of the size of phosphatidylglycerol/antibiotic liposomes established that the mean diameter of liposomes containing antibiotics was 200-350 nm, very close to that of liposomes without them.

Liposomes as potential masking agents in sport doping. Part 2: Detection of liposome-entrapped haemoglobin by flow cytofluorimetry.

PubMed

Esposito, Simone; Colicchia, Sonia; de la Torre, Xavier; Donati, Francesco; Mazzarino, Monica; Botrè, Francesco

2017-02-01

This work presents an analytical procedure for the identification and characterization of liposome-entrapped haemoglobins, based on flow cytofluorimetry. Flow cytofluorimetric detection is carried out following labelling by two distinct fluorescent reagents, an anti-haemoglobin antibody, fluorescein isothiocyanate conjugated, and an anti-poly(ethylene glycol) antibody, streptavidin-phycoerythrin conjugated. This experimental strategy allows the detection of liposome-entrapped haemoglobins in aqueous media, including plasma; the efficacy of the proposed approach has been verified on whole blood samples added with the liposomal formulation (ex-vivo). Additionally, the proposed technique allows the characterization of several key parameters in the study of liposomal haemoglobins, including, for instance (1) the determination of the degree of haemoglobin entrapment by liposomes; (2) the poly(ethylene glycol) insertion efficiency; and (3) the evaluation of liposome-entrapped haemoglobins stability following storage at 4 °C, allowing to follow both the process of haemoglobin loss from liposomes and the liposome degradation. The procedure is proposed for the detection and characterization of liposome-entrapped haemoglobin formulations to control their misuse in sport, but is also suggested for further applications in biological and clinical laboratory investigations. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Manufacturing Methods for Liposome Adjuvants.

PubMed

Perrie, Yvonne; Kastner, Elisabeth; Khadke, Swapnil; Roces, Carla B; Stone, Peter

2017-01-01

A wide range of studies have shown that liposomes can act as suitable adjuvants for a range of vaccine antigens. Properties such as their amphiphilic character and biphasic nature allow them to incorporate antigens within the lipid bilayer, on the surface, or encapsulated within the inner core. However, appropriate methods for the manufacture of liposomes are limited and this has resulted in issues with cost, supply, and wider scale application of these systems. Within this chapter we explore manufacturing processes that can be used for the production of liposomal adjuvants, and we outline new manufacturing methods can that offer fast, scalable, and cost-effective production of liposomal adjuvants.

An evaluation of the anti-tumor efficacy of oleanolic acid-loaded PEGylated liposomes

NASA Astrophysics Data System (ADS)

Tang, Shengnan; Gao, Dawei; Zhao, Tingting; Zhou, Jing; Zhao, Xiaoning

2013-06-01

The effective delivery of oleanolic acid (OA) to the target site has several benefits in therapy for different pathologies. However, the delivery of OA is challenging due to its poor aqueous solubility. The study aims to evaluate the tumor inhibition effect of the PEGylated OA nanoliposome on the U14 cervical carcinoma cell line. In our previous study, OA was successfully encapsulated into PEGylated liposome with the modified ethanol injection method. Oral administration of PEGylated OA liposome was demonstrated to be more efficient in inhibiting xenograft tumors. The results of organ index indicated that PEG liposome exhibited higher anti-tumor activity and lower cytotoxicity. It was also found that OA and OA liposomes induced tumor cell apoptosis detected by flow cytometry. Furthermore, effects of OA on the morphology of tumor and other tissues were observed by hematoxylin and eosin staining. The histopathology sections did not show pathological changes in kidney or liver in tested mice. In contrast, there was a significant difference in tumor tissues between treatment groups and the negative control group. These observations imply that PEGylated liposomes seem to have advantages for cancer therapy in terms of effective delivery of OA.

High-Performance Liquid Chromatography (HPLC) Quantification of Liposome-Delivered Doxorubicin in Arthritic Joints of Collagen-Induced Arthritis Rats.

PubMed

Niu, Hongqing; Xu, Menghua; Li, Shuangtian; Chen, Junwei; Luo, Jing; Zhao, Xiangcong; Gao, Chong; Li, Xiaofeng

2017-04-14

BACKGROUND Neoangiogenesis occurring in inflamed articular synovium in early rheumatoid arthritis (RA) is characterized by enhanced vascular permeability that allows nanoparticle agents, including liposomes, to deliver encapsulated drugs to arthritic joints and subsequently improve therapeutic efficacy and reduce adverse effects. However, the targeting distribution of liposomes in arthritic joints during RA has not been quantitatively demonstrated. We performed this study to evaluate the targeting distribution of PEGylated doxorubicin liposomes in the arthritic joints of collagen-induced arthritis (CIA) rats by high-performance liquid chromatography (HPLC). MATERIAL AND METHODS Two doxorubicin formulations were administered to CIA rats via tail intravenous injection at a single dose (50 mg/m²). CIA rats were sacrificed and the tissues of the inflamed ankle joints were collected. The content of doxorubicin in the arthritic joints was analyzed by a validated and reproducible HPLC method. A two-way ANOVA for 2×5 factorial design was used for statistical analysis. RESULTS The developed HPLC method was sensitive, precise, and reproducible. The method was successfully applied to quantify doxorubicin content in arthritic tissues. At each time point (6, 12, 24, 48, and 72 h), doxorubicin content in the arthritic joints of the doxorubicin liposome group (DOX-LIP group) was higher than in the free doxorubicin group (DOX group) (P<0.05). In the DOX-LIP group, doxorubicin levels in the arthritic joints increased gradually and significantly in the interval of 6-72 h post-administration. CONCLUSIONS PEGylated doxorubicin liposomes were targeted to, accumulated, and retained in the arthritic joints of CIA rats. The present study indicates that liposome encapsulation increases the therapeutic efficacy of antirheumatic drugs, presenting a promising therapeutic strategy for RA.

Encapsulated microbubbles and echogenic liposomes for contrast ultrasound imaging and targeted drug delivery

PubMed Central

Paul, Shirshendu; Nahire, Rahul; Mallik, Sanku; Sarkar, Kausik

2014-01-01

Micron- to nanometer-sized ultrasound agents, like encapsulated microbubbles and echogenic liposomes, are being developed for diagnostic imaging and ultrasound mediated drug/gene delivery. This review provides an overview of the current state of the art of the mathematical models of the acoustic behavior of ultrasound contrast microbubbles. We also present a review of the in vitro experimental characterization of the acoustic properties of microbubble based contrast agents undertaken in our laboratory. The hierarchical two-pronged approach of modeling contrast agents we developed is demonstrated for a lipid coated (Sonazoid™) and a polymer shelled (poly D-L-lactic acid) contrast microbubbles. The acoustic and drug release properties of the newly developed echogenic liposomes are discussed for their use as simultaneous imaging and drug/gene delivery agents. Although echogenicity is conclusively demonstrated in experiments, its physical mechanisms remain uncertain. Addressing questions raised here will accelerate further development and eventual clinical approval of these novel technologies. PMID:26097272

Inertial cavitation to non-invasively trigger and monitor intratumoral release of drug from intravenously delivered liposomes.

PubMed

Graham, Susan M; Carlisle, Robert; Choi, James J; Stevenson, Mark; Shah, Apurva R; Myers, Rachel S; Fisher, Kerry; Peregrino, Miriam-Bazan; Seymour, Len; Coussios, Constantin C

2014-03-28

The encapsulation of cytotoxic drugs within liposomes enhances pharmacokinetics and allows passive accumulation within tumors. However, liposomes designed to achieve good stability during the delivery phase often have compromised activity at the target site. This problem of inefficient and unpredictable drug release is compounded by the present lack of low-cost, non-invasive methods to measure such release. Here we show that focused ultrasound, used at pressures similar to those applied during diagnostic ultrasound scanning, can be utilised to both trigger and monitor release of payload from liposomes. Notably, drug release was influenced by liposome composition and the presence of SonoVue® microbubbles, which provided the nuclei for the initiation of an event known as inertial cavitation. In vitro studies demonstrated that liposomes formulated with a high proportion of 1,2 distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) released up to 30% of payload following ultrasound exposure in the presence of SonoVue®, provided that the exposure created sufficient inertial cavitation events, as characterised by violent bubble collapse and the generation of broadband acoustic emissions. In contrast a 'Doxil'-like liposome formulation gave no such triggered release. In pre-clinical studies, ultrasound was used as a non-invasive, targeted stimulus to trigger a 16-fold increase in the level of payload release within tumors following intravenous delivery. The inertial cavitation events driving this release could be measured remotely in real-time and were a reliable predictor of drug release. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Reconstitution of Contractile FtsZ Rings in Liposomes

PubMed Central

Osawa, Masaki; Anderson, David E.; Erickson, Harold P.

2009-01-01

FtsZ is a tubulin homolog and the major cytoskeletal protein in bacterial cell division. It assembles into the Z ring, which contains FtsZ and a dozen other division proteins, and constricts to divide the cell. We have constructed a membrane-targeted FtsZ (FtsZ-mts) by splicing an amphipathic helix to its C terminus. When mixed with lipid vesicles, FtsZ-mts was incorporated into the interior of some tubular vesicles. There it formed multiple Z rings that could move laterally in both directions along the length of the liposome and coalesce into brighter Z rings. Brighter Z rings produced visible constrictions in the liposome, suggesting that FtsZ itself can assemble the Z ring and generate a force. No other proteins were needed for assembly and force generation. PMID:18420899

Preparation, Characterization, and Preliminary In Vitro Testing of Nanoceria-Loaded Liposomes

PubMed Central

Grillone, Agostina; Li, Tianshu; Battaglini, Matteo; Scarpellini, Alice; Takeoka, Shinji

2017-01-01

Cerium oxide nanoparticles (nanoceria), well known for their pro- and antioxidant features, have been recently proposed for the treatment of several pathologies, including cancer and neurodegenerative diseases. However, interaction between nanoceria and biological molecules such as proteins and lipids, short blood circulation time, and the need of a targeted delivery to desired sites are some aspects that require strong attention for further progresses in the clinical application of these nanoparticles. The aim of this work is the encapsulation of nanoceria into a liposomal formulation in order to improve their therapeutic potentialities. After the preparation through a reverse-phase evaporation method, size, Z-potential, morphology, and loading efficiency of nanoceria-loaded liposomes were investigated. Finally, preliminary in vitro studies were performed to test cell uptake efficiency and preserved antioxidant activity. Nanoceria-loaded liposomes showed a good colloidal stability, an excellent biocompatibility, and strong antioxidant properties due to the unaltered activity of the entrapped nanoceria. With these results, the possibility of exploiting liposomes as carriers for cerium oxide nanoparticles is demonstrated here for the first time, thus opening exciting new opportunities for in vivo applications. PMID:28926967

Octanol-assisted liposome assembly on chip

PubMed Central

Deshpande, Siddharth; Caspi, Yaron; Meijering, Anna E. C.; Dekker, Cees

2016-01-01

Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5–20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin to bubble blowing, an inner aqueous phase and a surrounding lipid-carrying 1-octanol phase is pinched off by outer fluid streams. Such hydrodynamic flow focusing results in double-emulsion droplets that spontaneously develop a side-connected 1-octanol pocket. Owing to interfacial energy minimization, the pocket splits off to yield fully assembled solvent-free liposomes within minutes. This solves the long-standing fundamental problem of prolonged presence of residual oil in the liposome bilayer. We demonstrate the unilamellarity of liposomes with functional α-haemolysin protein pores in the membrane and validate the biocompatibility by inner leaflet localization of bacterial divisome proteins (FtsZ and ZipA). OLA offers a versatile platform for future analytical tools, delivery systems, nanoreactors and synthetic cells. PMID:26794442

Octanol-assisted liposome assembly on chip.

PubMed

Deshpande, Siddharth; Caspi, Yaron; Meijering, Anna E C; Dekker, Cees

2016-01-22

Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5-20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin to bubble blowing, an inner aqueous phase and a surrounding lipid-carrying 1-octanol phase is pinched off by outer fluid streams. Such hydrodynamic flow focusing results in double-emulsion droplets that spontaneously develop a side-connected 1-octanol pocket. Owing to interfacial energy minimization, the pocket splits off to yield fully assembled solvent-free liposomes within minutes. This solves the long-standing fundamental problem of prolonged presence of residual oil in the liposome bilayer. We demonstrate the unilamellarity of liposomes with functional α-haemolysin protein pores in the membrane and validate the biocompatibility by inner leaflet localization of bacterial divisome proteins (FtsZ and ZipA). OLA offers a versatile platform for future analytical tools, delivery systems, nanoreactors and synthetic cells.

Octanol-assisted liposome assembly on chip

NASA Astrophysics Data System (ADS)

Deshpande, Siddharth; Caspi, Yaron; Meijering, Anna E. C.; Dekker, Cees

2016-01-01

Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5-20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin to bubble blowing, an inner aqueous phase and a surrounding lipid-carrying 1-octanol phase is pinched off by outer fluid streams. Such hydrodynamic flow focusing results in double-emulsion droplets that spontaneously develop a side-connected 1-octanol pocket. Owing to interfacial energy minimization, the pocket splits off to yield fully assembled solvent-free liposomes within minutes. This solves the long-standing fundamental problem of prolonged presence of residual oil in the liposome bilayer. We demonstrate the unilamellarity of liposomes with functional α-haemolysin protein pores in the membrane and validate the biocompatibility by inner leaflet localization of bacterial divisome proteins (FtsZ and ZipA). OLA offers a versatile platform for future analytical tools, delivery systems, nanoreactors and synthetic cells.

Gemcitabine treatment of rat soft tissue sarcoma with phosphatidyldiglycerol-based thermosensitive liposomes.

PubMed

Limmer, Simone; Hahn, Jasmin; Schmidt, Rebecca; Wachholz, Kirsten; Zengerle, Anja; Lechner, Katharina; Eibl, Hansjörg; Issels, Rolf D; Hossann, Martin; Lindner, Lars H

2014-09-01

The pyrimidine analogue gemcitabine (dFdC) is frequently used in the treatment of patients with solid tumors. However, after i.v. application dFdC is rapidly inactivated by metabolization. Here, the potential of thermosensitive liposomes based on 1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol (DPPG2-TSL) were investigated as carrier and targeting system for delivery of dFdC in combination with local hyperthermia (HT). DPPG2-TSL were prepared by the lipid film hydration and extrusion method and characterized by dynamic light scattering, thin layer chromatography, phosphate assay and HPLC. In vivo experiments were performed in Brown Norway rats with a syngeneic soft tissue sarcoma. Local HT treatment was performed by light exposure. DPPG2-TSL were stable at 37°C in serum and showed a temperature dependent dFdC release >40°C. Plasma half-life of dFdC was strongly increased from 0.07 h (non-liposomal) to 0.53 h (liposomal, vesicle size 105 nm) or 2.59 h (liposomal, 129 nm). Therapy of BN175 tumors with dFdC encapsulated in DPPG2-TSL + HT showed significant improvement in tumor growth delay compared to non-liposomal dFdC without HT (p < 0.05), non-liposomal dFdC with HT (p < 0.01), and liposomal dFdC without HT (p < 0.05), respectively. Gemcitabine encapsulated in DPPG2-TSL in combination with local HT is a promising tool for the treatment of solid tumors. Therefore, these encouraging results ask for further investigation and evaluation.

Use of liposomes as injectable-drug delivery systems.

PubMed

Ostro, M J; Cullis, P R

1989-08-01

The formation of liposomes and their application as delivery systems for injectable drugs are described. Liposomes are microscopic vesicles composed of one or more lipid membranes surrounding discrete aqueous compartments. These vesicles can encapsulate water-soluble drugs in their aqueous spaces and lipid-soluble drugs within the membrane itself. Liposomes release their contents by interacting with cells in one of four ways: adsorption, endocytosis, lipid exchange, or fusion. Liposome-entrapped drugs are distributed within the body much differently than free drugs; when administered intravenously to healthy animals and humans, most of the injected vesicles accumulate in the liver, spleen, lungs, bone marrow, and lymph nodes. Liposomes also accumulate preferentially at the sites of inflammation and infection and in some solid tumors; however, the reason for this accumulation is not clear. Four major factors influence liposomes' in vivo behavior and biodistribution: (1) liposomes tend to leak if cholesterol is not included in the vesicle membrane, (2) small liposomes are cleared more slowly than large liposomes, (3) the half-life of a liposome increases as the lipid dose increases, and (4) charged liposomal systems are cleared more rapidly than uncharged systems. The most advanced application of liposome-based therapy is in the treatment of systemic fungal infections, especially with amphotericin B. Liposomes are also under investigation for treatment of neoplastic disorders. Liposomes' uses in cancer therapy include encapsulation of known antineoplastic agents such as doxorubicin and methotrexate, delivery of immune modulators such as N-acetylmuramyl-L-alanine-D-isoglutamine, and encapsulation of new chemical entities that are synthesized with lipophilic segments tailored for insertion into lipid bilayers. Liposomal formulations of injectable antimicrobial agents and antineoplastic agents already are undergoing clinical testing, and most probably will receive

Liposome encapsulation of chelating agents

DOEpatents

Rahman, Yueh Erh

1976-01-13

A method for transferring a chelating agent across a cellular membrane by encapsulating the charged chelating agent within liposomes and carrying the liposome-encapsulated chelating agent to the cellular membrane where the liposomes containing the chelating agent will be taken up by the cells, thereby transferring the chelating agent across the cellular membrane. A chelating agent can be introduced into the interior of a cell of a living organism wherein the liposomes will be decomposed, releasing the chelating agent to the interior of the cell. The released chelating agent will complex intracellularly deposited toxic heavy metals, permitting the more soluble metal complex to transfer across the cellular membrane from the cell and subsequently be removed from the living organism.

Getting into the brain: liposome-based strategies for effective drug delivery across the blood–brain barrier

PubMed Central

Vieira, Débora B; Gamarra, Lionel F

2016-01-01

This review summarizes articles that have been reported in literature on liposome-based strategies for effective drug delivery across the blood–brain barrier. Due to their unique physicochemical characteristics, liposomes have been widely investigated for their application in drug delivery and in vivo bioimaging for the treatment and/or diagnosis of neurological diseases, such as Alzheimer’s, Parkinson’s, stroke, and glioma. Several strategies have been used to deliver drug and/or imaging agents to the brain. Covalent ligation of such macromolecules as peptides, antibodies, and RNA aptamers is an effective method for receptor-targeting liposomes, which allows their blood–brain barrier penetration and/or the delivery of their therapeutic molecule specifically to the disease site. Additionally, methods have been employed for the development of liposomes that can respond to external stimuli. It can be concluded that the development of liposomes for brain delivery is still in its infancy, although these systems have the potential to revolutionize the ways in which medicine is administered. PMID:27799765

Getting into the brain: liposome-based strategies for effective drug delivery across the blood-brain barrier.

PubMed

Vieira, Débora B; Gamarra, Lionel F

This review summarizes articles that have been reported in literature on liposome-based strategies for effective drug delivery across the blood-brain barrier. Due to their unique physicochemical characteristics, liposomes have been widely investigated for their application in drug delivery and in vivo bioimaging for the treatment and/or diagnosis of neurological diseases, such as Alzheimer's, Parkinson's, stroke, and glioma. Several strategies have been used to deliver drug and/or imaging agents to the brain. Covalent ligation of such macromolecules as peptides, antibodies, and RNA aptamers is an effective method for receptor-targeting liposomes, which allows their blood-brain barrier penetration and/or the delivery of their therapeutic molecule specifically to the disease site. Additionally, methods have been employed for the development of liposomes that can respond to external stimuli. It can be concluded that the development of liposomes for brain delivery is still in its infancy, although these systems have the potential to revolutionize the ways in which medicine is administered.

Design considerations for liposomal vaccines: Influence of formulation parameters on antibody and cell-mediated immune responses to liposome associated antigens

PubMed Central

Watson, Douglas S.; Endsley, Aaron N.; Huang, Leaf

2012-01-01

Liposomes (phospholipid bilayer vesicles) are versatile and robust delivery systems for induction of antibody and T lymphocyte responses to associated subunit antigens. In the last 15 years, liposome vaccine technology has matured and now several vaccines containing liposome-based adjuvants have been approved for human use or have reached late stages of clinical evaluation. Given the intensifying interest in liposome-based vaccines, it is important to understand precisely how liposomes interact with the immune system and stimulate immunity. It has become clear that the physicochemical properties of liposomal vaccines – method of antigen attachment, lipid composition, bilayer fluidity, particle charge, and other properties – exert dramatic effects on the resulting immune response. Here, we present a comprehensive review of the physicochemical properties of liposomal vaccines and how they influence immune responses. A discussion of novel and emerging immunomodulators that are suitable for inclusion in liposomal vaccines is also presented. Through a comprehensive analysis of the body of liposomal vaccine literature, we enumerate a series of principles that can guide the rational design of liposomal vaccines to elicit immune responses of a desired magnitude and quality. We also identify major unanswered questions in the field, pointing the direction for future study. PMID:22306376

Nanoparticles target early-stage breast cancer metastasis in vivo

NASA Astrophysics Data System (ADS)

Goldman, Evgeniya; Zinger, Assaf; da Silva, Dana; Yaari, Zvi; Kajal, Ashima; Vardi-Oknin, Dikla; Goldfeder, Mor; Schroeder, Josh E.; Shainsky-Roitman, Janna; Hershkovitz, Dov; Schroeder, Avi

2017-10-01

Despite advances in cancer therapy, treating cancer after it has metastasized remains an unmet clinical challenge. In this study we demonstrate that 100 nm liposomes target triple-negative murine breast-cancer metastases post intravenous administration. Metastatic breast cancer was induced in BALB/c mice either experimentally, by a tail vein injection of 4T1 cells, or spontaneously, after implanting a primary tumor xenograft. To track their biodistribution in vivo the liposomes were labeled with multi-modal diagnostic agents, including indocyanine green and rhodamine for whole-animal fluorescent imaging, gadolinium for magnetic resonance imaging (MRI), and europium for a quantitative biodistribution analysis. The accumulation of liposomes in the metastases peaked at 24 h post the intravenous administration, similar to the time they peaked in the primary tumor. The efficiency of liposomal targeting to the metastatic tissue exceeded that of a non-liposomal agent by 4.5-fold. Liposomes were detected at very early stages in the metastatic progression, including metastatic lesions smaller than 2 mm in diameter. Surprisingly, while nanoparticles target breast cancer metastasis, they may also be found in elevated levels in the pre-metastatic niche, several days before metastases are visualized by MRI or histologically in the tissue. This study highlights the promise of diagnostic and therapeutic nanoparticles for treating metastatic cancer, possibly even for preventing the onset of the metastatic dissemination by targeting the pre-metastatic niche.

Disintegrable NIR Light Triggered Gold Nanorods Supported Liposomal Nanohybrids for Cancer Theranostics.

PubMed

Chauhan, Deepak S; Prasad, Rajendra; Devrukhkar, Janhavi; Selvaraj, Kaliaperumal; Srivastava, Rohit

2018-05-16

In this work, facile synthesis and application of targeted, dual therapeutic gold nanorods-liposome (GNR-Lipos) nanohybrid for imaging guided photothermal therapy and chemotherapy is investigated. The dual therapeutic GNR-Lipos nanohybrid consists of GNR supported, and doxorubicin (DOX) loaded liposome. GNRs not only serve as a photothermal agent and increase the drug release in intracellular environment of cancer cells, but also provide mechanical strength to liposomes by being decorated both inside and outside of bilayer surfaces. The designed nanohybrid shows a remarkable response for synergistic chemophotothermal therapy compared to only chemotherapy or photothermal therapy. The NIR response, efficient uptake by the cells, disintegration of GNR-Lipos nanohybrid, and synergistic therapeutic effect of photothermal and chemotherapy over breast cancer cells MDA-MB-231 are studied for the better development of a biocompatible nanomaterial based multifunctional cancer theranostic agent.

Comparative therapeutic efficacy of rhenium-188 radiolabeled-liposome and 5-fluorouracil in LS-174T human colon carcinoma solid tumor xenografts.

PubMed

Hsu, Chin-Wei; Chang, Ya-Jen; Chang, Chih-Hsien; Chen, Liang-Cheng; Lan, Keng-Li; Ting, Gann; Lee, Te-Wei

2012-10-01

Nanoliposomes are important carriers capable of packaging drugs for various delivery applications. Rhenium-188-radiolabeled liposome ((188)Re-liposome) has potential for radiotherapy and diagnostic imaging. To evaluate the targeting of (188)Re-liposome, biodistribution, microSPECT/CT, whole-body autoradiography (WBAR), and pharmacokinetics were performed in LS-174T human tumor-bearing mice. The comparative therapeutic efficacy of (188)Re-liposome and 5-fluorouracil (5-FU) was assessed according to inhibition of tumor growth and the survival ratio. The highest uptake of (188)Re-liposome in LS-174T tumor was found at 24 hours by biodistribution and microSPECT/CT imaging, showing a positive correlation for tumor targeting of (188)Re-liposome using the Pearson's correlation analysis (r=0.997). Pharmacokinetics of (188)Re-liposome showed the properties of high circulation time and high bioavailability (mean residence time [MRT]=18.8 hours, area under the curve [AUC]=1371%ID/g·h). For therapeutic efficacy, the tumor-bearing mice treated with (188)Re-liposome (80% maximum tolerated dose [MTD], 23.7 MBq) showed better tumor growth inhibition and longer survival time than those treated with 5-FU (80% MTD, 144 mg/kg). The median survival time for mice treated with (188)Re-liposome (58.5 days; p<0.05) was significantly better than those of 5-FU (48.25 days; p>0.05) and normal saline-treated mice (43.63 days). Dosimetry study revealed that the (188)Re-liposome did not lead to high absorbed doses in normal tissue, but did in small tumors. These results of imaging and biodistribution indicated the highly specific accumulation of tumor after intravenous (i.v.) injection of (188)Re-liposome. The therapeutic efficacy of radiotherapeutics of (188)Re-liposome have been confirmed in a LS-174T solid tumor animal model, which points to the potential benefit and promise of passive nanoliposome delivered radiotherapeutics for cancer treatment.

Development and In Vitro Characterization of a Gemcitabine-loaded MUC4-targeted Immunoliposome Against Pancreatic Ductal Adenocarcinoma.

PubMed

Urey, Carlos; Hilmersson, Katarzyma Said; Andersson, Bodil; Ansari, Daniel; Andersson, Roland

2017-11-01

Pancreatic Ductal adeno-carcinoma (PDAC) is a devastating disease. Gemcitabine is the standard chemotherapeutic agent against PDAC but has only limited effectiveness. The aim of the study was to develop and study the targeting affinity and in vitro antiproliferative effect of a MUC4-targeted gemcitabine-loaded immuno-liposome for treatment of PDAC. Gemcitabine-loaded immunoliposomes were developed by grafting anti-MUC4 antibodies to the liposomal surface. Targeting affinity was compared in vitro between immunoliposomes and non-targeted liposomes and anti-proliferative effect was compared in vitro between free drug, non-targeted liposomal gemcitabine and MUC4-targeted immunoliposomal gemcitabine on a MUC4-positive pancreatic cancer cell line, Capan-1. Development of a MUC4-targeted immunoliposome was confirmed and characterized by immunoblots and size characterization. The MUC4-targeted immunoliposome showed a significantly higher targeting affinity compared to the non-targeted liposomes and also showed an improved antiproliferative effect compared to free and non-targeted liposomal drug. Successful development and characterization of a MUC4-targeted immunoliposome shows promising results for a targeted treatment and improved retention of gemcitabine for treatment of PDAC. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Ultrasound, liposomes, and drug delivery: principles for using ultrasound to control the release of drugs from liposomes.

PubMed

Schroeder, Avi; Kost, Joseph; Barenholz, Yechezkel

2009-11-01

Ultrasound is used in many medical applications, such as imaging, blood flow analysis, dentistry, liposuction, tumor and fibroid ablation, and kidney stone disruption. In the past, low frequency ultrasound (LFUS) was the main method to downsize multilamellar (micron range) vesicles into small (nano scale) unilamellar vesicles. Recently, the ability of ultrasound to induce localized and controlled drug release from liposomes, utilizing thermal and/or mechanical effects, has been shown. This review, deals with the interaction of ultrasound with liposomes, focusing mainly on the mechanical mechanism of drug release from liposomes using LFUS. The effects of liposome lipid composition and physicochemical properties, on one hand, and of LFUS parameters, on the other, on liposomal drug release, are addressed. Acoustic cavitation, in which gas bubbles oscillate and collapse in the medium, thereby introducing intense mechanical strains, increases release substantially. We suggest that the mechanism of release may involve formation and collapse of small gas nuclei in the hydrophobic region of the lipid bilayer during exposure to LFUS, thereby inducing the formation of transient pores through which drugs are released. Introducing PEG-lipopolymers to the liposome bilayer enhances responsivity to LFUS, most likely due to absorption of ultrasonic energy by the highly hydrated PEG headgroups. The presence of amphiphiles, such as phospholipids with unsaturated acyl chains, which destabilize the lipid bilayer, also increases liposome susceptibility to LFUS. Application of these principles to design highly LFUS-responsive liposomes is discussed.

In Vivo Evaluation of Magnetic Targeting in Mice Colon Tumors with Ultra-Magnetic Liposomes Monitored by MRI.

PubMed

Thébault, Caroline J; Ramniceanu, Grégory; Michel, Aude; Beauvineau, Claire; Girard, Christian; Seguin, Johanne; Mignet, Nathalie; Ménager, Christine; Doan, Bich-Thuy

2018-06-25

The development of theranostic nanocarriers as an innovative therapy against cancer has been improved by targeting properties in order to optimize the drug delivery to safely achieve its desired therapeutic effect. The aim of this paper is to evaluate the magnetic targeting (MT) efficiency of ultra-magnetic liposomes (UML) into CT26 murine colon tumor by magnetic resonance imaging (MRI). Dynamic susceptibility contrast MRI was applied to assess the bloodstream circulation time. A novel semi-quantitative method called %I 0.25 , based on the intensity distribution in T 2 * -weighted MRI images was developed to compare the accumulation of T 2 contrast agent in tumors with or without MT. To evaluate the efficiency of magnetic targeting, the percentage of pixels under the intensity value I 0.25 (I 0.25  = 0.25(I max  - I min )) was calculated on the intensity distribution histogram. This innovative method of processing MRI images showed the MT efficiency by a %I 0.25 that was significantly higher in tumors using MT compared to passive accumulation, from 15.3 to 28.6 %. This methodology was validated by ex vivo methods with an iron concentration that is 3-fold higher in tumors using MT. We have developed a method that allows a semi-quantitative evaluation of targeting efficiency in tumors, which could be applied to different T 2 contrast agents.

Specific targeting to B cells by lipid-based nanoparticles conjugated with a novel CD22-ScFv.

PubMed

Loomis, Kristin; Smith, Brandon; Feng, Yang; Garg, Himanshu; Yavlovich, Amichai; Campbell-Massa, Ryan; Dimitrov, Dimiter S; Blumenthal, Robert; Xiao, Xiaodong; Puri, Anu

2010-04-01

The CD22 antigen is a viable target for therapeutic intervention for B-cell lymphomas. Several therapeutic anti-CD22 antibodies as well as an anti-CD22-based immunotoxin (HA22) are currently under investigation in clinical settings. Coupling of anti-CD22 reagents with a nano-drug delivery vehicle is projected to significantly improve treatment efficacies. Therefore, we generated a mutant of the targeting segment of HA22 (a CD22 scFv) to increase its soluble expression (mut-HA22), and conjugated it to the surface of sonicated liposomes to generate immunoliposomes (mut-HA22-liposomes). We examined liposome binding and uptake by CD22(+) B-lymphocytes (BJAB) by using calcein and/or rhodamine PE-labeled liposomes. We also tested the effect of targeting on cellular toxicity with doxorubicin-loaded liposomes. We report that: (i) Binding of mut-HA22-liposomes to BJAB cells was significantly greater than liposomes not conjugated with mut-HA22 (control liposomes), and mut-HA22-liposomes bind to and are taken in by BJAB cells in a dose and temperature-dependent manner, respectively; (ii) This binding occurred via the interaction with the cellular CD22 as pre-incubation of the cells with mut-HA22 blocked subsequent liposome binding; (iii) Intracellular localization of mut-HA22-liposomes at 37 degrees C but not at 4 degrees C indicated that our targeted liposomes were taken up through an energy dependent process via receptor-mediated endocytosis; and (iv) Mut-HA22-liposomes loaded with doxorubicin exhibited at least 2-3 fold more accumulation of doxorubicin in BJAB cells as compared to control liposomes. Moreover, these liposomes showed at least a 2-4 fold enhanced killing of BJAB or Raji cells (CD22(+)), but not SUP-T1 cells (CD22(-)). Taken together these data suggest that these 2nd-generation liposomes may serve as promising carriers for targeted drug delivery to treat patients suffering from B-cell lymphoma. Published by Elsevier Inc.

A novel method to label preformed liposomes with 64Cu for positron emission tomography (PET) imaging.

PubMed

Seo, Jai Woong; Zhang, Hua; Kukis, David L; Meares, Claude F; Ferrara, Katherine W

2008-12-01

Radiolabeling of liposomes with 64Cu (t(1/2)=12.7 h) is attractive for molecular imaging and monitoring drug delivery. A simple chelation procedure, performed at a low temperature and under mild conditions, is required to radiolabel preloaded liposomes without lipid hydrolysis or the release of the encapsulated contents. Here, we report a 64Cu postlabeling method for liposomes. A 64Cu-specific chelator, 6-[p-(bromoacetamido)benzyl]-1,4,8,11-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid (BAT), was conjugated with an artificial lipid to form a BAT-PEG-lipid. After incorporation of 0.5% (mol/mol) BAT-PEG-lipid during liposome formulation, liposomes were successfully labeled with 64Cu in 0.1 M NH4OAc pH 5 buffer at 35 degrees C for 30-40 min with an incorporation yield as high as 95%. After 48 h of incubation of 64Cu-liposomes in 50/50 serum/PBS solution, more than 88% of the 64Cu label was still associated with liposomes. After injection of liposomal 64Cu in a mouse model, 44+/-6.9, 21+/-2.7, 15+/-2.5, and 7.4+/-1.1 (n=4) % of the injected dose per cubic centimeter remained within the blood pool at 30 min, 18, 28, and 48 h, respectively. The biodistribution at 48 h after injection verified that 7.0+/-0.47 (n=4) and 1.4+/-0.58 (n=3) % of the injected dose per gram of liposomal 64Cu and free 64Cu remained in the blood pool, respectively. Our results suggest that this fast and easy 64Cu labeling of liposomes could be exploited in tracking liposomes in vivo for medical imaging and targeted delivery.

Uptake and intracellular processing of PEG-liposomes and PEG-immunoliposomes by kupffer cells in vitro 1 *.

PubMed

Koning, G A; Morselt, H W; Kamps, J A; Scherphof, G L

2001-01-01

Specific targeting of drugs to for instance tumors or sites of inflammation may be achieved by means of immunoliposomes carrying site-specific antibodies on their surface. The presence of these antibodies may adversely affect the circulation kinetics of such liposomes as a result of interactions with cells of the mononuclear phagocyte system (MPS), mainly represented by macrophages in liver and spleen. The additional insertion of poly(ethylene glycol) chains on the surface of the immunoliposomes may, however, attenuate this effect. We investigated the influence of surface-coupled rat or rabbit antibodies and of PEG on the uptake of liposomes by rat Kupffer cells in culture with (3)H-cholesteryloleyl ether as a metabolically stable marker. Additionally, we assessed the effects of surface-bound IgG and PEG on the intracellular processing of the liposomes by the Kupffer cells, based on a double-label assay using the (3)H-cholesteryl ether as an absolute measure for liposome uptake and the hydrolysis of the degradable marker cholesteryl-(14)C-oleate as relative measure of degradation. Attachment of both rat and rabbit antibodies to PEG-free liposomes caused a several-fold increase in apparent size. The uptake by Kupffer cells, however, was 3-4 fold higher for the rat than for the rabbit IgG liposomes. The presence of PEG drastically reduced the difference between these liposome types. Uptake of liposomes without antibodies amounted to only about 10% (non-PEGylated) or less (PEGylated) of that of the immunoliposomes. In contrast to the marked effects of IgG and PEG on Kupffer cell uptake, the rate of intracellular processing of the liposomes remained virtually unaffected by the presence of these substances on the liposomal surface. These observations are discussed with respect to the design of optimally formulated liposomal drug preparations, combining maximal therapeutic efficacy with minimal toxicity.

Determination of the Subcellular Distribution of Liposomes Using Confocal Microscopy.

PubMed

Solomon, Melani A

2017-01-01

It is being increasingly recognized that therapeutics need to be delivered to specific organelle targets within cells. Liposomes are versatile lipid-based drug delivery vehicles that can be surface-modified to deliver the loaded cargo to specific subcellular locations within the cell. Hence, the development of such technology requires a means of measuring the subcellular distribution possibly by utilizing imaging techniques that can visualize and quantitate the extent of this subcellular localization. The apparent increase of resolution along the Z-axis offered by confocal microscopy makes this technique suitable for such studies. In this chapter, we describe the application of confocal laser scanning microscopy (CLSM) to determine the subcellular distribution of fluorescently labeled mitochondriotropic liposomes.

Drug release through liposome pores.

PubMed

Dan, Nily

2015-02-01

Electrical, ultrasound and other types of external fields are known to induce the formation of pores in cellular and model membranes. This paper examines drug release through field induced liposome pores using Monte Carlo simulations. We find that drug release rates vary as a function of pore size and spacing, as well as the overall fraction of surface area covered by pores: The rate of release from liposomes is found to increase rapidly with pore surface coverage, approaching that of the fully ruptured liposome at fractional pore areas. For a given pore surface coverage, the pore size affects the release rate in the limit of low coverage, but not when the pores cover a relatively high fraction of the liposome surface area. On the other hand, for a given pore size and surface coverage, the distribution of pores significantly affects the release in the limit of high surface coverage: The rate of release from a liposome covered with a regularly spaced array of pores is, in this limit, higher than the release rate from (most) systems where the pores are distributed randomly on the liposome surface. In contrast, there is little effect of the pore distribution on release when the pore surface coverage is low. The simulation results are in good agreement with the predictions of detailed diffusion models. Copyright © 2014 Elsevier B.V. All rights reserved.

Liposomes containing NY‑ESO‑1/tetanus toxoid and adjuvant peptides targeted to human dendritic cells via the Fc receptor for cancer vaccines.

PubMed

Cruz, Luis J; Rueda, Felix; Simón, Lorena; Cordobilla, Begoña; Albericio, Fernando; Domingo, Joan C

2014-04-01

To improve the immunological response against tumors, a vaccine based on nanoliposomes targeted to the Fcg-receptor was developed to enhance the immunogenicity of tumor-associated antigens (TAAs). Using human dendritic cells in vitro, a fragment of the TAA NY-ESO-1 combined with a T-helper peptide from the tetanus toxoid encapsulated in nanoliposomes was evaluated. In addition, peptides Palm-IL-1 and MAP-IFN-g were coadministered as adjuvants to enhance the immunological response. Coadministration of Palm-IL-1 or MAP-IFN-g peptide adjuvants and the hybrid NY-ESO-1-tetanus toxoid (soluble or encapsulated in nanoliposomes without targeting) increased immunogenicity. However, the most potent immunological response was obtained when the peptide adjuvants were encapsulated in liposomes targeted to human dendritic cells via the Fc receptor. This targeted vaccine strategy is a promising tool to activate and deliver antigens to dendritic cells, thus improving immunotherapeutic response in situations in which the immune system is frequently compromised, as in advanced cancers.

Biophysical characterization of gold nanoparticles-loaded liposomes.

PubMed

Mady, Mohsen Mahmoud; Fathy, Mohamed Mahmoud; Youssef, Tareq; Khalil, Wafaa Mohamed

2012-10-01

Gold nanoparticles were prepared and loaded into the bilayer of dipalmitoylphosphatidylcholine (DPPC) liposomes, named as gold-loaded liposomes. Biophysical characterization of gold-loaded liposomes was studied by transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy as well as turbidity and rheological measurements. FTIR measurements showed that gold nanoparticles made significant changes in the frequency of the CH(2) stretching bands, revealing that gold nanoparticles increased the number of gauche conformers and create a conformational change within the acyl chains of phospholipids. The transmission electron micrographs (TEM) revealed that gold nanoparticles were loaded in the liposomal bilayer. The zeta potential of DPPC liposomes had a more negative value after incorporating of Au NPs into liposomal membranes. Turbidity studies revealed that the loading of gold nanoparticles into DPPC liposomes results in shifting the temperature of the main phase transition to a lower value. The membrane fluidity of DPPC bilayer was increased by loading the gold nanoparticles as shown from rheological measurements. Knowledge gained in this study may open the door to pursuing liposomes as a viable strategy for Au NPs delivery in many diagnostic and therapeutic applications. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Codelivery of dihydroartemisinin and doxorubicin in mannosylated liposomes for drug-resistant colon cancer therapy

PubMed Central

Kang, Xue-jia; Wang, Hui-yuan; Peng, Hui-ge; Chen, Bin-fan; Zhang, Wen-yuan; Wu, Ai-hua; Xu, Qin; Huang, Yong-zhuo

2017-01-01

Multidrug resistance (MDR) is a major hurdle in cancer chemotherapy and makes the treatment benefits unsustainable. Combination therapy is a commonly used method for overcoming MDR. In this study we investigated the anti-MDR effect of dihydroartemisinin (DHA), a derivative of artemisinin, in combination with doxorubicin (Dox) in drug-resistant human colon tumor HCT8/ADR cells. We developed a tumor-targeting codelivery system, in which the two drugs were co-encapsulated into the mannosylated liposomes (Man-liposomes). The Man-liposomes had a mean diameter of 158.8 nm and zeta potential of −15.8 mV. In the HCT8/ADR cells that overexpress the mannose receptors, the Man-liposomes altered the intracellular distribution of Dox, resulting in a high accumulation of Dox in the nuclei and thus displaying the highest cytotoxicity (IC50=0.073 μg/mL) among all the groups. In a subcutaneous HCT8/ADR tumor xenograft model, administration of the Man-liposomes resulted in a tumor inhibition rate of 88.59%, compared to that of 47.46% or 70.54%, respectively, for the treatment with free Dox or free Dox+DHA. The mechanisms underlying the anti-MDR effect of the Man-liposomes involved preferential nuclear accumulation of the therapeutic agents, enhanced cancer cell apoptosis, downregulation of Bcl-xl, and the induction of autophagy. PMID:28479604

Starch-coated magnetic liposomes as an inhalable carrier for accumulation of fasudil in the pulmonary vasculature.

PubMed

Nahar, Kamrun; Absar, Shahriar; Patel, Brijeshkumar; Ahsan, Fakhrul

2014-04-10

In this study, we tested the feasibility of magnetic liposomes as a carrier for pulmonary preferential accumulation of fasudil, an investigational drug for the treatment of pulmonary arterial hypertension (PAH). To develop an optimal inhalable formulation, various magnetic liposomes were prepared and characterized for physicochemical properties, storage stability and in vitro release profiles. Select formulations were evaluated for uptake by pulmonary arterial smooth muscle cells (PASMCs) - target cells - using fluorescence microscopy and HPLC. The efficacy of the magnetic liposomes in reducing hyperplasia was tested in 5-HT-induced proliferated PASMCs. The drug absorption profiles upon intratracheal administration were monitored in healthy rats. Optimized spherical liposomes - with mean size of 170 nm, zeta potential of -35mV and entrapment efficiency of 85% - exhibited an 80% cumulative drug release over 120 h. Fluorescence microscopic study revealed an enhanced uptake of liposomes by PASMCs under an applied magnetic field: the uptake was 3-fold greater compared with that observed in the absence of magnetic field. PASMC proliferation was reduced by 40% under the influence of the magnetic field. Optimized liposomes appeared to be safe when incubated with PASMCs and bronchial epithelial cells. Compared with plain fasudil, intratracheal magnetic liposomes containing fasudil extended the half-life and area under the curve by 27- and 14-fold, respectively. Magnetic-liposomes could be a viable delivery system for site-specific treatment of PAH. Copyright © 2014 Elsevier B.V. All rights reserved.

The anti-tumour agent lonidamine is a potent inhibitor of the mitochondrial pyruvate carrier and plasma membrane monocarboxylate transporters.

PubMed

Nancolas, Bethany; Guo, Lili; Zhou, Rong; Nath, Kavindra; Nelson, David S; Leeper, Dennis B; Blair, Ian A; Glickson, Jerry D; Halestrap, Andrew P

2016-04-01

Lonidamine (LND) is an anti-tumour drug particularly effective at selectively sensitizing tumours to chemotherapy, hyperthermia and radiotherapy, although its precise mode of action remains unclear. It has been reported to perturb the bioenergetics of cells by inhibiting glycolysis and mitochondrial respiration, whereas indirect evidence suggests it may also inhibit L-lactic acid efflux from cells mediated by members of the proton-linked monocarboxylate transporter (MCT) family and also pyruvate uptake into the mitochondria by the mitochondrial pyruvate carrier (MPC). In the present study, we test these possibilities directly. We demonstrate that LND potently inhibits MPC activity in isolated rat liver mitochondria (Ki2.5 μM) and co-operatively inhibits L-lactate transport by MCT1, MCT2 and MCT4 expressed in Xenopus laevisoocytes with K0.5 and Hill coefficient values of 36-40 μM and 1.65-1.85 respectively. In rat heart mitochondria LND inhibited the MPC with similar potency and uncoupled oxidation of pyruvate was inhibited more effectively (IC50~ 7 μM) than other substrates including glutamate (IC50~ 20 μM). In isolated DB-1 melanoma cells 1-10 μM LND increased L-lactate output, consistent with MPC inhibition, but higher concentrations (150 μM) decreased L-lactate output whereas increasing intracellular [L-lactate] > 5-fold, consistent with MCT inhibition. We conclude that MPC inhibition is the most sensitive anti-tumour target for LND, with additional inhibitory effects on MCT-mediated L-lactic acid efflux and glutamine/glutamate oxidation. Together these actions can account for published data on the selective tumour effects of LND onL-lactate, intracellular pH (pHi) and ATP levels that can be partially mimicked by the established MPC and MCT inhibitor α-cyano-4-hydroxycinnamate (CHC). © 2016 Authors; published by Portland Press Limited.

The anti-tumour agent lonidamine is a potent inhibitor of the mitochondrial pyruvate carrier and plasma membrane monocarboxylate transporters

PubMed Central

Nancolas, Bethany; Guo, Lili; Zhou, Rong; Nath, Kavindra; Nelson, David S.; Leeper, Dennis B.; Blair, Ian A.; Glickson, Jerry D.; Halestrap, Andrew P.

2016-01-01

Lonidamine (LND) is an anti-tumour drug particularly effective at selectively sensitising tumours to chemotherapy, hyperthermia and radiotherapy, although its precise mode of action remains unclear. It has been reported to perturb the bioenergetics of cells by inhibiting glycolysis and mitochondrial respiration, while indirect evidence suggests it may also inhibit L-lactic acid efflux from cells mediated by members of the proton-linked monocarboxylate transporter (MCT) family and also pyruvate uptake into the mitochondria by the mitochondrial pyruvate carrier (MPC). Here we test these possibilities directly. We demonstrate that LND potently inhibits MPC activity in isolated rat liver mitochondria (Ki 2.5 μM) and cooperatively inhibits L-lactate transport by MCT1, MCT2 and MCT4 expressed in Xenopus laevis oocytes with K0.5 and Hill Coefficient values of 36–40 μM and 1.65–1.85. In rat heart mitochondria LND inhibited the MPC with similar potency and uncoupled oxidation of pyruvate was inhibited more effectively (IC50 ~7 μM) than other substrates including glutamate (IC50 ~20 μM). In isolated DB-1 melanoma cells 1–10 μM LND increased L-lactate output, consistent with MPC inhibition, but higher concentrations (150 μM) decreased L-lactate output while increasing intracellular [L-lactate] > five-fold, consistent with MCT inhibition. We conclude that MPC inhibition is the most sensitive anti-tumour target for LND, with additional inhibitory effects on MCT-mediated L-lactic acid efflux and glutamine/glutamate oxidation. Together these actions can account for published data on the selective tumour effects of LND on L-lactate, intracellular pH (pHi) and ATP levels that can be partially mimicked by the established MPC and MCT inhibitor α-cyano-4-hydroxycinnamate. PMID:26831515

Cocktail of Superoxide Dismutase and Fasudil Encapsulated in Targeted Liposomes Slows PAH Progression at a Reduced Dosing Frequency.

PubMed

Gupta, Nilesh; Rashid, Jahidur; Nozik-Grayck, Eva; McMurtry, Ivan F; Stenmark, Kurt R; Ahsan, Fakhrul

2017-03-06

Currently, two or more pulmonary vasodilators are used to treat pulmonary arterial hypertension (PAH), but conventional vasodilators alone cannot reverse disease progression. In this study, we tested the hypothesis that a combination therapy comprising a vasodilator plus a therapeutic agent that slows pulmonary arterial remodeling and right heart hypertrophy is an efficacious alternative to current vasodilator-based PAH therapy. Thus, we encapsulated a cocktail of superoxide dismutase (SOD), a superoxide scavenger, and fasudil, a specific rho-kinase inhibitor, into a liposomal formulation equipped with a homing peptide, CAR. We evaluated the effect of the formulations on pulmonary hemodynamics in monocrotaline-induced PAH rats (MCT-induced PAH) and assessed the formulation's efficacy in slowing the disease progression in Sugen-5416/hypoxia-induced PAH rats (SU/hypoxia-induced PAH). For acute studies, we monitored both mean pulmonary and systemic arterial pressures (mPAP and mSAP) for 2 to 6 h after a single dose of the plain drugs or formulations. In chronic studies, PAH rats received plain drugs every 48 h and the formulations every 72 h for 21 days. In MCT-induced PAH rats, CAR-modified liposomes containing fasudil plus SOD elicited a more pronounced, prolonged, and selective reduction in mPAP than unmodified liposomes and plain drugs did. In SU/hypoxia-induced PAH rats, the formulation produced a >50% reduction in mPAP and slowed right ventricular hypertrophy. When compared with individual plain drugs or combination, CAR-modified-liposomes containing both drugs reduced the extent of collagen deposition, muscularization of arteries, increased SOD levels in the lungs, and decreased the expression of pSTAT-3 and p-MYPT1. Overall, CAR-modified-liposomes of SOD plus fasudil, given every 72 h, was as efficacious as plain drugs, given every 48 h, suggesting that the formulation can reduce the total drug intake, systemic exposures, and dosing frequency.

Long-Circulating, pH-Sensitive Liposomes.

PubMed

Momekova, Denitsa; Rangelov, Stanislav; Lambov, Nikolay

2017-01-01

A major limiting factor for the wide application of pH-sensitive liposomes is their recognition and sequestration by the phagocytes of the reticuloendothelial system, which conditions a very short circulation half-life. Typically prolonged circulation of liposomes is achieved by grafting their membranes with pegylated phospholipids (PEG-lipids), which have been shown, however, to deteriorate membrane integrity on one hand and to hamper the pH-responsiveness on the other. Hence, the need for novel alternative surface modifying agents to ensure effective half-life prolongation of pH-sensitive liposomes is a subject of intensive research. A series of copolymers having short blocks of lipid-mimetic units has been shown to sterically stabilize conventional liposomes based on different phospholipids. This has prompted us to broaden their utilization to pH-sensitive liposomes, too. The present contribution gives a thorough account on the chemical synthesis of these copolymers their incorporation in DOPE:CHEMs pH-sensitive liposomes and detailed explanation on the battery of techniques for the biopharmaceutical characterization of the prepared formulations in terms of pH-responsiveness, cellular internalization, in vivo pharmacokinetics and biodistribution.

Long-circulating, pH-sensitive liposomes.

PubMed

Momekova, Denitsa; Rangelov, Stanislav; Lambov, Nikolay

2010-01-01

A major limiting factor for the wide application of pH-sensitive liposomes is their recognition and sequestration by the phagocytes of the reticulo-endothelial system, which conditions a very short circulation half-life. Typically prolonged circulation of liposomes is achieved by grafting their membranes with pegylated phospholipids (PEG-lipids), which have been shown, however, to deteriorate membrane integrity on one hand and to hamper the pH-responsiveness on the other. Hence, the need for novel alternative surface modifying agents to ensure effective half-life prolongation of pH-sensitive liposomes is a subject of intensive research. A series of copolymers having short blocks of lipid-mimetic units has been shown to sterically stabilize conventional liposomes based on different phospholipids. This has prompted us to broaden their utilization to pH-sensitive liposomes, too. The present contribution gives thorough account on the chemical synthesis of these copolymers their incorporation in DOPE:CHEMs pH-sensitive liposomes and detailed explanation on the battery of techniques for the biopharmaceutical characterization of the prepared formulations in terms of pH-responsiveness, cellular internalization, in vivo pharmacokinetics and biodistribution.

Accelerated Blood Clearance (ABC) Phenomenon Favors the Accumulation of Tartar Emetic in Pegylated Liposomes in BALB/c Mice Liver.

PubMed

Lopes, Tamara C M; Silva, Débora F; Costa, Walyson C; Frézard, Frédéric; Barichello, José M; Silva-Barcellos, Neila M; de Lima, Wanderson G; Rezende, Simone A

2018-01-01

Tartar emetic (TE) was the first drug used to treat leishmaniasis. However, its use was discontinued due to high toxicity. Association of TE with liposomes is a strategy to reduce its side effects. Pegylated liposomes (Lpeg) present lower rates of uptake by macrophages and prolonged circulation compared to their nonpegylated counterparts. However, repeated administration of Lpeg can cause an Accelerated Blood Clearance (ABC) phenomenon, whereby recognition of liposomes by antibodies results in faster phagocytosis. This work evaluated the effect of TE administration on histopathological aspects and the effect of the ABC phenomenon on targeting and toxicity in mice. Our results show that treatment with free or liposomal TE had no effect on the erythrocyte count, on liver and spleen weight, and on hepatic, splenic, and cardiac histology in mice. Severe lesions were observed on the kidneys of animals treated with a single dose of free TE. Treatment with TE in Lpeg after induction of ABC phenomenon caused a significant increase in Sb level in the liver without toxicity. Furthermore, mice treated with TE in liposomes showed normal renal histopathology. These results suggest site-specific targeting of Sb to the liver after induction of ABC phenomenon with no toxicity to other organs.

Accelerated Blood Clearance (ABC) Phenomenon Favors the Accumulation of Tartar Emetic in Pegylated Liposomes in BALB/c Mice Liver

PubMed Central

Lopes, Tamara C. M.; Silva, Débora F.; Costa, Walyson C.; Barichello, José M.; Silva-Barcellos, Neila M.; de Lima, Wanderson G.

2018-01-01

Tartar emetic (TE) was the first drug used to treat leishmaniasis. However, its use was discontinued due to high toxicity. Association of TE with liposomes is a strategy to reduce its side effects. Pegylated liposomes (Lpeg) present lower rates of uptake by macrophages and prolonged circulation compared to their nonpegylated counterparts. However, repeated administration of Lpeg can cause an Accelerated Blood Clearance (ABC) phenomenon, whereby recognition of liposomes by antibodies results in faster phagocytosis. This work evaluated the effect of TE administration on histopathological aspects and the effect of the ABC phenomenon on targeting and toxicity in mice. Our results show that treatment with free or liposomal TE had no effect on the erythrocyte count, on liver and spleen weight, and on hepatic, splenic, and cardiac histology in mice. Severe lesions were observed on the kidneys of animals treated with a single dose of free TE. Treatment with TE in Lpeg after induction of ABC phenomenon caused a significant increase in Sb level in the liver without toxicity. Furthermore, mice treated with TE in liposomes showed normal renal histopathology. These results suggest site-specific targeting of Sb to the liver after induction of ABC phenomenon with no toxicity to other organs. PMID:29593857

The role of cavitation in liposome formation.

PubMed

Richardson, Eric S; Pitt, William G; Woodbury, Dixon J

2007-12-15

Liposome size is a vital parameter of many quantitative biophysical studies. Sonication, or exposure to ultrasound, is used widely to manufacture artificial liposomes, yet little is known about the mechanism by which liposomes are affected by ultrasound. Cavitation, or the oscillation of small gas bubbles in a pressure-varying field, has been shown to be responsible for many biophysical effects of ultrasound on cells. In this study, we correlate the presence and type of cavitation with a decrease in liposome size. Aqueous lipid suspensions surrounding a hydrophone were exposed to various intensities of ultrasound and hydrostatic pressures before measuring their size distribution with dynamic light scattering. As expected, increasing ultrasound intensity at atmospheric pressure decreased the average liposome diameter. The presence of collapse cavitation was manifested in the acoustic spectrum at high ultrasonic intensities. Increasing hydrostatic pressure was shown to inhibit the presence of collapse cavitation. Collapse cavitation, however, did not correlate with decreases in liposome size, as changes in size still occurred when collapse cavitation was inhibited either by lowering ultrasound intensity or by increasing static pressure. We propose a mechanism whereby stable cavitation, another type of cavitation present in sound fields, causes fluid shearing of liposomes and reduction of liposome size. A mathematical model was developed based on the Rayleigh-Plesset equation of bubble dynamics and principles of acoustic microstreaming to estimate the shear field magnitude around an oscillating bubble. This model predicts the ultrasound intensities and pressures needed to create shear fields sufficient to cause liposome size change, and correlates well with our experimental data.

Antileishmanial Activity of Liposomal Clarithromycin against Leishmania Major Promastigotes

PubMed Central

Sazgarnia, Ameneh; Zabolinejad, Naghmeh; Layegh, Pouran; Rajabi, Omid; Berenji, Fariba; Javidi, Zari; Salari, Roshanak

2012-01-01

Objective(s) Cutaneous leishmaniasis is a common parasitic disease which is endemic in some parts of the world. In vitro and in vivo studies have shown azithromycin efficacy on some Leishmania species. Because of structural similarity between clarithromycin and azithromycin and efficacy of clarithromycin against intracellular organisms and due to the absence of previous studies in this respect, we decided to evaluate the efficacy of clarithromycin against promastigotes of L. major in vitro. Materials and Method First, liposomal and non- liposomal clarithromycin were prepared, then both forms of the drug were incubated with promastigotes for 24 hr in NNN culture media without red phenol in the presence of 5% FCS with different concentrations as follows: 20, 40, 80, 100, 200 and 500 µg/ml. Results According to the results, clarithromycin in both liposomal and non- liposomal forms has in vitro activity against the promastigotes of L. major. The concentration of drug that killed 50% of parasites (ED 50) was 169 and 253.6 µg/ml for liposomal and non- liposomal forms, respectively which shows that lower concentrations of liposomal drug are required to have the same effect as non- liposomal drug and the liposomal form of the drug is more effective than non- liposomal form. Conclusion Clarithromycin in both liposomal and non- liposomal forms has in vitro activity against the promastigotes of L. major. PMID:23658854

Antileishmanial Activity of Liposomal Clarithromycin against Leishmania Major Promastigotes.

PubMed

Sazgarnia, Ameneh; Zabolinejad, Naghmeh; Layegh, Pouran; Rajabi, Omid; Berenji, Fariba; Javidi, Zari; Salari, Roshanak

2012-11-01

Cutaneous leishmaniasis is a common parasitic disease which is endemic in some parts of the world. In vitro and in vivo studies have shown azithromycin efficacy on some Leishmania species. Because of structural similarity between clarithromycin and azithromycin and efficacy of clarithromycin against intracellular organisms and due to the absence of previous studies in this respect, we decided to evaluate the efficacy of clarithromycin against promastigotes of L. major in vitro. First, liposomal and non- liposomal clarithromycin were prepared, then both forms of the drug were incubated with promastigotes for 24 hr in NNN culture media without red phenol in the presence of 5% FCS with different concentrations as follows: 20, 40, 80, 100, 200 and 500 µg/ml. According to the results, clarithromycin in both liposomal and non- liposomal forms has in vitro activity against the promastigotes of L. major. The concentration of drug that killed 50% of parasites (ED 50) was 169 and 253.6 µg/ml for liposomal and non- liposomal forms, respectively which shows that lower concentrations of liposomal drug are required to have the same effect as non- liposomal drug and the liposomal form of the drug is more effective than non- liposomal form. Clarithromycin in both liposomal and non- liposomal forms has in vitro activity against the promastigotes of L. major.

Preparation and the influencing factors of timozolomide liposomes.

PubMed

Kong, Bin; Sun, Yong; Li, Yongjian; Hu, Dejian

2009-01-01

To prepare timozolomide liposomes for administration through nasal mucous membrane, we studied the factors of the preparation of the liposomes. The timozolomide liposomes were prepared by the ammonium sulphate gradient method; electroscopy and laser particle analyzer were utilized to determine the conformation, size and distribution of timozolomide liposomes; high performance liquid chromatography (HPLC) was applied to determine the entrapping efficiency of timozolomide liposomes; then we studied the influences of the concentration of ammonium sulphate solution, temperature, and the drug-to-lipid ratio on the entrapping efficiency. The average size of timozolomide liposomes was 185 nm; the entrapping efficiency was 90.3%. The entrapping efficiency was enhanced with the increasing of the concentration of ammonium sulphate solution and the rising of temperature, and decreased with the increasing of the drug-to-lipid ratio. The timozolomide liposomes with high entrapping efficiency, small and even particle sizes could be prepared by the simple and convenient ammonium sulphate gradient method. The primary influencing factors on the entrapping efficiency of timozolomide liposomes were the concentration of ammonium sulphate solution, the temperature, and the drug-to-lipid ratio.

Liposomal Bupivacaine Injection Technique in Total Knee Arthroplasty.

PubMed

Meneghini, R Michael; Bagsby, Deren; Ireland, Philip H; Ziemba-Davis, Mary; Lovro, Luke R

2017-01-01

Liposomal bupivacaine has gained popularity for pain control after total knee arthroplasty (TKA), yet its true efficacy remains unproven. We compared the efficacy of two different periarticular injection (PAI) techniques for liposomal bupivacaine with a conventional PAI control group. This retrospective cohort study compared consecutive patients undergoing TKA with a manufacturer-recommended, optimized injection technique for liposomal bupivacaine, a traditional injection technique for liposomal bupivacaine, and a conventional PAI of ropivacaine, morphine, and epinephrine. The optimized technique utilized a smaller gauge needle and more injection sites. Self-reported pain scores, rescue opioids, and side effects were compared. There were 41 patients in the liposomal bupivacaine optimized injection group, 60 in the liposomal bupivacaine traditional injection group, and 184 in the conventional PAI control group. PAI liposomal bupivacaine delivered via manufacturer-recommended technique offered no benefit over PAI ropivacaine, morphine, and epinephrine. Mean pain scores and the proportions reporting no or mild pain, time to first opioid, and amount of opioids consumed were not better with PAI liposomal bupivacaine compared with PAI ropivacaine, morphine, and epinephrine. The use of the manufacturer-recommended technique for PAI of liposomal bupivacaine does not offer benefit over a conventional, less expensive PAI during TKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Mannose-coated gadolinium liposomes for improved magnetic resonance imaging in acute pancreatitis.

PubMed

Tian, Bing; Liu, Ri; Chen, Shiyue; Chen, Luguang; Liu, Fang; Jia, Guorong; Dong, Yinmei; Li, Jing; Chen, Huaiwen; Lu, Jianping

2017-01-01

Acute pancreatitis (AP) is an acute inflammatory condition of the pancreas. The symptoms, treatment, and prognosis of mild and severe AP are different, and severe AP is a potentially life-threatening disease with a high incidence of complications and high mortality rate. Thus, it is urgent to develop an effective approach to reliably discriminate between mild and severe AP. We have developed novel gadolinium-diethylenetriaminepentaacetic (Gd-DTPA)-loaded mannosylated liposomes (named thereafter M-Gd-NL) that preferably target macrophages in AP. The targeting ability of M-Gd-NL toward macrophages in AP and its ability to discriminate between mild and severe AP were evaluated. The liposomes were of desired particle size (~100 nm), Gd-DTPA encapsulation efficiency (~85%), and stability. M-Gd-NL and non-targeted Gd-DTPA-loaded liposomes (Gd-NL) exhibited increased relaxivity compared with Gd-DTPA. Compared with Gd-NL and Gd-DTPA, M-Gd-NL showed increased uptake in macrophages, resulting in increased T 1 imaging ability both in vitro (macrophage cell line) and in vivo (severe AP model). Importantly, M-Gd-NL had the ability to discriminate between mild and severe AP, as reflected by a significantly higher T 1 magnetic resonance imaging signal in severe AP than in mild AP. M-Gd-NL did not show severe organ toxicity in rats. Our data suggest that M-Gd-NL had enhanced magnetic resonance imaging ability by targeting macrophages in AP and good ability to discriminate between mild and severe AP. We believe that M-Gd-NL could shed new light on the diagnosis of AP in the near future.

Vitamin A-coupled liposome system targeting free cholesterol accumulation in hepatic stellate cells offers a beneficial therapeutic strategy for liver fibrosis.

PubMed

Furuhashi, Hirotaka; Tomita, Kengo; Teratani, Toshiaki; Shimizu, Motonori; Nishikawa, Makoto; Higashiyama, Masaaki; Takajo, Takeshi; Shirakabe, Kazuhiko; Maruta, Koji; Okada, Yoshikiyo; Kurihara, Chie; Watanabe, Chikako; Komoto, Shunsuke; Aosasa, Suefumi; Nagao, Shigeaki; Yamamoto, Junji; Miura, Soichiro; Hokari, Ryota

2018-04-01

Liver fibrosis is a life-threatening disorder for which no approved therapy is available. Recently, we reported that mouse hepatic stellate cell (HSC) activation increased free cholesterol (FC) accumulation, partly by enhancing signaling through sterol regulatory element-binding protein 2 (SREBP2) and microRNA-33a (miR-33a), which resulted in HSC sensitization to transforming growth factor-β (TGFβ)-induced activation in a "vicious cycle" of liver fibrosis. Human HSCs were isolated from surgical liver specimens from control patients and patients with liver fibrosis. C57BL/6 mice were treated with carbon tetrachloride for 4 weeks and concurrently given SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes. In human activated HSCs obtained from patients with liver fibrosis, FC accumulation was enhanced independently of serum cholesterol levels through increased signaling by both SREBP2 and miR-33a. This increased FC accumulation enhanced Toll-like receptor 4 (TLR4) protein levels and lowered the TGFβ-pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor) mRNA levels in HSCs. Notably, in a mouse liver fibrosis model, reduction of FC accumulation, specifically in activated HSCs by suppression of SREBP2 or miR-33a expression using SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes, downregulated TLR4 signaling, increased Bambi expression, and consequently ameliorated liver fibrosis. Our results suggest that FC accumulation in HSCs, as an intracellular mediator promoting HSC activation, contributes to a vicious cycle of HSC activation in human and mouse liver fibrosis independent of serum cholesterol levels. Targeting FC accumulation-related molecules in HSCs through a vitamin A-coupled liposomal system represents a favorable therapeutic strategy for liver fibrosis. © 2017 The Japan Society of Hepatology.

In silico study of liposome transport across biomembranes

NASA Astrophysics Data System (ADS)

Glukhova, O. E.; Zyktin, A. A.; Slepchenkov, M. M.

2018-02-01

At present, the liposomes are widely used as drug carriers in different areas of clinical medicine. One of them is the transport across the blood-brain barrier (BBB) into brain. This work is devoted to computational modeling of liposome transport across biomembrane. For this, we applied the MARTINI coarse-grained model. The liposome model is constructed from lipid (DPPC) and cholesterol (CHOL) molecules in a percentage ratio of 60/40. The diameter of the liposome is 28 nm. The equilibrium configuration of the liposome is achieved by minimizing its total energy. A series of numerical experiments was conducted in order to study the transport of the drug contained in the liposome across the cell membrane. All computer manipulations were carried out using software packages GROMACS and Kvazar at a temperature of 305-310 K. All the processes were simulated for 10-20 ns. The speed of the liposome ranged from 0.89 to 1.07 m/s. It should be noted that the selected speed range corresponds to the rate of human blood flow. Various cases of the angle of the incidence of the liposome on the membrane surface were also considered. Since the process of contact of the liposome with the membrane can be characterized as rolling in most cases, the angles were considered in the interval from 0 to 20 degrees. Based on the simulation results, we determined optimal pathways (from the point of view of energy) for liposome penetration across biomembrane.

Hyaluronic Acid-Based pH-Sensitive Polymer-Modified Liposomes for Cell-Specific Intracellular Drug Delivery Systems.

PubMed

Miyazaki, Maiko; Yuba, Eiji; Hayashi, Hiroshi; Harada, Atsushi; Kono, Kenji

2018-01-17

For the enhancement of therapeutic effects and reduction of side effects derived from anticancer drugs in cancer chemotherapy, it is imperative to develop drug delivery systems with cancer-specificity and controlled release function inside cancer cells. pH-sensitive liposomes are useful as an intracellular drug delivery system because of their abilities to transfer their contents into the cell interior through fusion or destabilization of endosome, which has weakly acidic environment. We earlier reported liposomes modified with various types of pH-sensitive polymers based on synthetic polymers and biopolymers as vehicles for intracellular drug delivery systems. In this study, hyaluronic acid (HA)-based pH-sensitive polymers were designed as multifunctional polymers having not only pH-sensitivity but also targeting properties to cells expressing CD44, which is known as a cancer cell surface marker. Carboxyl group-introduced HA derivatives of two types, MGlu-HA and CHex-HA, which have a more hydrophobic side chain structure than that of MGlu-HA, were synthesized by reaction with various dicarboxylic anhydrides. These polymer-modified liposomes were stable at neutral pH, but showed content release under weakly acidic conditions. CHex-HA-modified liposomes delivered their contents into CD44-expressing cells more efficiently than HA-modified or MGlu-HA-modified liposomes or unmodified liposomes, whereas the same liposomes were taken up only slightly by cells expressing CD44 proteins less. Competition assay using free HA or other polymers revealed that HA derivative-modified liposomes might be recognized by CD44. Therefore, HA-derivative-modified liposomes are useful as cell-specific intracellular drug delivery systems.

Topology of Surface Ligands on Liposomes: Characterization Based on the Terms, Incorporation Ratio, Surface Anchor Density, and Reaction Yield.

PubMed

Lee, Shang-Hsuan; Sato, Yusuke; Hyodo, Mamoru; Harashima, Hideyoshi

2016-01-01

The surface topology of ligands on liposomes is an important factor in active targeting in drug delivery systems. Accurately evaluating the density of anchors and bioactive functional ligands on a liposomal surface is critical for ensuring the efficient delivery of liposomes. For evaluating surface ligand density, it is necessary to clarify that on the ligand-modified liposomal surfaces, some anchors are attached to ligands but some are not. To distinguish between these situations, a key parameter, surface anchor density, was introduced to specify amount of total anchors on the liposomal surface. Second, the parameter reaction yield was introduced to identify the amount of ligand-attached anchors among total anchors, since the conjugation efficiency is not always the same nor 100%. Combining these independent parameters, we derived: incorporation ratio=surface anchor density×reaction yield. The term incorporation ratio defines the surface ligand density. Since the surface anchor density represents the density of polyethylene glycol (PEG) on the surfaces in most cases, it also determines liposomal function. It is possible to accurately characterize various PEG and ligand densities and to define the surface topologies. In conclusion, this quantitative methodology can standardize the liposome preparation process and qualify the modified liposomal surfaces.

Ultrasmall superparamagnetic iron oxide (USPIO)-based liposomes as magnetic resonance imaging probes.

PubMed

Frascione, Daniela; Diwoky, Clemens; Almer, Gunter; Opriessnig, Peter; Vonach, Caroline; Gradauer, Kerstin; Leitinger, Gerd; Mangge, Harald; Stollberger, Rudolf; Prassl, Ruth

2012-01-01

Magnetic liposomes (MLs) are phospholipid vesicles that encapsulate magnetic and/or paramagnetic nanoparticles. They are applied as contrast agents for magnetic resonance imaging (MRI). MLs have an advantage over free magnetic nanocores, in that various functional groups can be attached to the surface of liposomes for ligand-specific targeting. We have synthesized PEG-coated sterically-stabilized magnetic liposomes (sMLs) containing ultrasmall superparamagnetic iron oxides (USPIOs) with the aim of generating stable liposomal carriers equipped with a high payload of USPIOs for enhanced MRI contrast. Regarding iron oxide nanoparticles, we have applied two different commercially available surface-coated USPIOs; sMLs synthesized and loaded with USPIOs were compared in terms of magnetization and colloidal stability. The average diameter size, morphology, phospholipid membrane fluidity, and the iron content of the sMLs were determined by dynamic light scattering (DLS), transmission electron microscopy (TEM), fluorescence polarization, and absorption spectroscopy, respectively. A colorimetric assay using potassium thiocyanate (KSCN) was performed to evaluate the encapsulation efficiency (EE%) to express the amount of iron enclosed into a liposome. Subsequently, MRI measurements were carried out in vitro in agarose gel phantoms to evaluate the signal enhancement on T1- and T2-weighted sequences of sMLs. To monitor the biodistribution and the clearance of the particles over time in vivo, sMLs were injected in wild type mice. DLS revealed a mean particle diameter of sMLs in the range between 100 and 200 nm, as confirmed by TEM. An effective iron oxide loading was achieved just for one type of USPIO, with an EE% between 74% and 92%, depending on the initial Fe concentration (being higher for lower amounts of Fe). MRI measurements demonstrated the applicability of these nanostructures as MRI probes. Our results show that the development of sMLs is strictly dependent on the

Hemisynthetic trifluralin analogues incorporated in liposomes for the treatment of leishmanial infections.

PubMed

Carvalheiro, Manuela; Esteves, M Alexandra; Santos-Mateus, David; Lopes, Rui M; Rodrigues, M Armanda; Eleutério, Carla V; Scoulica, Effie; Santos-Gomes, Gabriela; Cruz, M Eugénia M

2015-06-01

Leishmaniasis, a vector-borne parasitic disease caused by Leishmania protozoa, is one of the most neglected tropical diseases in terms of drug discovery and development. Current treatment is based on a limited number of chemotherapeutic agents all of which present either/or resistance issues, severe toxicities and adverse reactions associated with extended treatment regimens, and high cost of therapy. Dinitroanilines are a new class of drugs with proven in vitro antileishmanial activity. In previous work a liposomal formulation of one dinitroaniline (TFL) was found to be active against Leishmania parasites in a murine model of visceral leishmaniasis (VL) and in the treatment of experimental canine leishmaniasis. In this study we have investigated the use of dinitroaniline analogues (TFL-A) associated to liposomes, as means to further improve TFL antileishmanial activity. The potential of the liposomal formulations was assessed in vitro against Leishmania infantum promastigotes and intracellular amastigotes and in vivo in a murine model of zoonotic VL. Free and liposomal TFL-A were active in vitro against Leishmania parasites, and they also exhibited reduced cytotoxicity and haemolytic activity. Treatment of infected mice with liposomal TFL-A reduced the amastigote loads in the spleen up to 97%, compared with the loads for untreated controls. These findings illustrate that chemical synthesis of new molecules associated with the use of Nano Drug Delivery Systems that naturally target the diseased organs could be a promising strategy for effective management of VL. Copyright © 2015 Elsevier B.V. All rights reserved.

The protein corona of circulating PEGylated liposomes.

PubMed

Palchetti, Sara; Colapicchioni, Valentina; Digiacomo, Luca; Caracciolo, Giulio; Pozzi, Daniela; Capriotti, Anna Laura; La Barbera, Giorgia; Laganà, Aldo

2016-02-01

Following systemic administration, liposomes are covered by a 'corona' of proteins, and preserving the surface functionality is challenging. Coating the liposome surface with polyethylene glycol (PEG) is the most widely used anti-opsonization strategy, but it cannot fully preclude protein adsorption. To date, protein binding has been studied following in vitro incubation to predict the fate of liposomes in vivo, while dynamic incubation mimicking in vivo conditions remains largely unexplored. The main aim of this investigation was to determine whether shear stress, produced by physiologically relevant dynamic flow, could influence the liposome-protein corona. The corona of circulating PEGylated liposome was thoroughly compared with that formed by incubation in vitro. Systematic comparison in terms of size, surface charge and quantitative composition was made by dynamic light scattering, microelectrophoresis and nano-liquid chromatography tandem mass spectrometry (nanoLC-MS/MS). Size of coronas formed under static vs. dynamic incubation did not appreciably differ from each other. On the other side, the corona of circulating liposomes was more negatively charged than its static counterpart. Of note, the variety of protein species in the corona formed in a dynamic flow was significantly wider. Collectively, these results demonstrated that the corona of circulating PEGylated liposomes can be considerably different from that formed in a static fluid. This seems to be a key factor to predict the biological activity of a liposomal formulation in a physiological environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Structural properties of liposomes from digital holographic microscopy

NASA Astrophysics Data System (ADS)

Di Maio, Isabelle L.; Carl, Daniel; Langehanenberg, Patrik; Valenzuela, Stella M.; Battle, Andrew R.; Al Khazaaly, Sabah; Killingsworth, Murray; Kemper, Bjorn; von Bally, Gert; Martin, Donald K.

2006-01-01

We have constructed liposomes from L alpha Phosphatidylcholine (PC) lipids, which are biomimetic lipids similar to those present in the membranes of mammalian cells. We propose an advance in the use of liposomes, such as for drug delivery, to incorporate into the liposomal membranes transport proteins that have been extracted from the lipid membranes of mammalian cells. In this paper, we describe the usage of a novel optical microscope to characterize the nanomechanical properties of these liposomes. We have applied the technique of digital holographic microscopy, using an instrument recently developed at the University of Münster, Germany. This system enabled us to measure quantitatively the structural changes in liposomes. We have investigated the deformations of these biomimetic lipids comprising these liposomes by applying osmotic stresses, in order to gain insight into the membrane environment prior to incorporation of cloned membrane transport proteins. This control of the nanomechanical properties is important in the stresses transmitted to mechanosensitive ion channels that we have incorporated into the liposomal membranes. These liposomes provide transporting vesicles that respond to mechanical stresses, such as those that occur during implantation.

Arraying of intact liposomes into chemically functionalized microwells.

PubMed

Kalyankar, Nikhil D; Sharma, Manoj K; Vaidya, Shyam V; Calhoun, David; Maldarelli, Charles; Couzis, Alexander; Gilchrist, Lane

2006-06-06

Here, we describe a protocol to bind individual, intact phospholipid bilayer liposomes, which are on the order of 1 microm in diameter, in microwells etched in a regular array on a silicon oxide substrate. The diameter of the wells is on the order of the liposome diameter, so only one liposome is located in each well. The background of the silicon oxide surface is functionalized with a PEG oligomer using the contact printing of a PEG silane to present a surface that resists the adsorption of proteins, lipid material, and liposomes. The interiors of the wells are functionalized with an aminosilane to facilitate the conjugation of biotin, which is then bound to Neutravidin. The avidin-coated well interiors bind the liposomes whose surfaces contain biotinylated lipids. The specific binding of the liposomes to the surface using the biotin-avidin linkage, together with the resistant nature of the background and the physical confinement of the wells, allows the liposomes to remain intact and to not unravel, rupture, and fuse onto the surface. We demonstrate this intact arraying using confocal laser scanning microscopy of fluorophores specifically tagging the microwells, the lipid bilayer, and the aqueous interior of the liposome.

Label-free CEST MRI Detection of Citicoline-Liposome Drug Delivery in Ischemic Stroke

PubMed Central

Liu, Huanling; Jablonska, Anna; Li, Yuguo; Cao, Suyi; Liu, Dexiang; Chen, Hanwei; Van Zijl, Peter CM; Bulte, Jeff W.M.; Janowski, Miroslaw; Walczak, Piotr; Liu, Guanshu

2016-01-01

ABSTRACT Citicoline (CDPC) is a natural supplement with well-documented neuroprotective effects in the treatment of neurodegenerative diseases. In the present study, we sought to exploit citicoline as a theranostic agent with its inherent chemical exchange saturation transfer (CEST) MRI signal, which can be directly used as an MRI guidance in the citicoline drug delivery. Our in vitro CEST MRI results showed citicoline has two inherent CEST signals at +1 and +2 ppm, attributed to exchangeable hydroxyl and amine protons, respectively. To facilitate the targeted drug delivery of citicoline to ischemic regions, we prepared liposomes encapsulating citicoline (CDPC-lipo) and characterized the particle properties and CEST MRI properties. The in vivo CEST MRI detection of liposomal citicoline was then examined in a rat brain model of unilateral transient ischemia induced by a two-hour middle cerebral artery occlusion. The results showed that the delivery of CPDC-lipo to the brain ischemic areas could be monitored and quantified by CEST MRI. When administered intra-arterially, CDPC-lipo clearly demonstrated a detectable CEST MRI contrast at 2 ppm. CEST MRI revealed that liposomes preferentially accumulated in the areas of ischemia with a disrupted blood-brain-barrier. We furthermore used CEST MRI to detect the improvement in drug delivery using CDPC-lipo targeted against vascular cell adhesion molecule (VCAM)-1 in the same animal model. The MRI findings were validated using fluorescence microscopy. Hence, liposomal citicoline represents a prototype theranostic system, where the therapeutic agent can be detected directly by CEST MRI in a label-free fashion. PMID:27446492

Fusogenic activity of PEGylated pH-sensitive liposomes.

PubMed

Vanić, Zeljka; Barnert, Sabine; Süss, Regine; Schubert, Rolf

2012-06-01

The aim of this study was to investigate the fusogenic properties of poly(ethylene glycol) (PEG)ylated dioleoylphosphatidylethanolamine/cholesteryl hemisuccinate (DOPE/CHEMS) liposomes. These pH-sensitive liposomes were prepared by incorporating two different PEG lipids: distearoylphosphatidylethanolamine (DSPE)-PEG₂₀₀₀ was mixed with the liposomal lipids using the conventional method, whereas sterol-PEG₁₁₀₀ was inserted into the outer monolayer of preformed vesicles. Both types of PEGylated liposomes were characterized and compared for their entrapment efficiency, zeta potential and size, and were tested in vitro for pH sensitivity by means of proton-induced leakage and membrane fusion activity. To mimic the routes of intracellular delivery, fusion between pH-sensitive liposomes and liposomes designed to simulate the endosomal membrane was studied. Our investigations confirmed that DOPE/CHEMS liposomes were capable of rapidly releasing calcein and of fusing upon acidification. However, after incorporation of DSPE-PEG₂₀₀₀ or sterol-PEG₁₁₀₀ into the membrane, pH sensitivity was significantly reduced; as the mol ratio of PEG-lipid was increased, the ability to fuse was decreased. Comparison between two different PEGylated pH-sensitive liposomes showed that only vesicles containing 0.6 mol% sterol-PEG₁₁₀₀ in the outer monolayer were still capable of fusing with the endosome-like liposomes and showing leakage of calcein at pH 5.5.

External beam radiotherapy synergizes 188Re-liposome against human esophageal cancer xenograft and modulates 188Re-liposome pharmacokinetics

PubMed Central

Chang, Chih-Hsien; Liu, Shin-Yi; Chi, Chih-Wen; Yu, Hsiang-Lin; Chang, Tsui-Jung; Tsai, Tung-Hu; Lee, Te-Wei; Chen, Yu-Jen

2015-01-01

External beam radiotherapy (EBRT) treats gross tumors and local microscopic diseases. Radionuclide therapy by radioisotopes can eradicate tumors systemically. Rhenium 188 (188Re)-liposome, a nanoparticle undergoing clinical trials, emits gamma rays for imaging validation and beta rays for therapy, with biodistribution profiles preferential to tumors. We designed a combinatory treatment and examined its effects on human esophageal cancer xenografts, a malignancy with potential treatment resistance and poor prognosis. Human esophageal cancer cell lines BE-3 (adenocarcinoma) and CE81T/VGH (squamous cell carcinoma) were implanted and compared. The radiochemical purity of 188Re-liposome exceeded 95%. Molecular imaging by NanoSPECT/CT showed that BE-3, but not CE81T/VGH, xenografts could uptake the 188Re-liposome. The combination of EBRT and 188Re-liposome inhibited tumor regrowth greater than each treatment alone, as the tumor growth inhibition rate was 30% with EBRT, 25% with 188Re-liposome, and 53% with the combination treatment at 21 days postinjection. Combinatory treatment had no additive adverse effects and significant biological toxicities on white blood cell counts, body weight, or liver and renal functions. EBRT significantly enhanced the excretion of 188Re-liposome into feces and urine. In conclusion, the combination of EBRT with 188Re-liposome might be a potential treatment modality for esophageal cancer. PMID:26056445

Binding of Diphtheria Toxin to Phospholipids in Liposomes

NASA Astrophysics Data System (ADS)

Alving, Carl R.; Iglewski, Barbara H.; Urban, Katharine A.; Moss, Joel; Richards, Roberta L.; Sadoff, Jerald C.

1980-04-01

Diphtheria toxin bound to the phosphate portion of some, but not all, phospholipids in liposomes. Liposomes consisting of dimyristoyl phosphatidylcholine and cholesterol did not bind toxin. Addition of 20 mol% (compared to dimyristoyl phosphatidylcholine) of dipalmitoyl phosphatidic acid, dicetyl phosphate, phosphatidylinositol phosphate, cardiolipin, or phosphatidylserine in the liposomes resulted in substantial binding of toxin. Inclusion of phosphatidylinositol in dimyristol phosphatidylcholine / cholesterol liposomes did not result in toxin binding. The calcium salt of dipalmitoyl phosphatidic acid was more effective than the sodium salt, and the highest level of binding occurred with liposomes consisting only of dipalmitoyl phosphatidic acid (calcium salt) and cholesterol. Binding of toxin to liposomes was dependent on pH, and the pattern of pH dependence varied with liposomes having different compositions. Incubation of diphtheria toxin with liposomes containing dicetyl phosphate resulted in maximal binding at pH 3.6, whereas binding to liposomes containing phosphatidylinositol phosphate was maximal above pH 7. Toxin did not bind to liposomes containing 20 mol% of a free fatty acid (palmitic acid) or a sulfated lipid (3-sulfogalactosylceramide). Toxin binding to dicetyl phosphate or phosphatidylinositol phosphate was inhibited by UTP, ATP, phosphocholine, or p-nitrophenyl phosphate, but not by uracil. We conclude that (a) diphtheria toxin binds specifically to the phosphate portion of certain phospholipids, (b) binding to phospholipids in liposomes is dependent on pH, but is not due only to electrostatic interaction, and (c) binding may be strongly influenced by the composition of adjacent phospholipids that do not bind toxin. We propose that a minor membrane phospholipid (such as phosphatidylinositol phosphate or phosphatidic acid), or that some other phosphorylated membrane molecule (such as a phosphoprotein) may be important in the initial binding of

Preparation and properties evaluation of a novel pH-sensitive liposomes based on imidazole-modified cholesterol derivatives.

PubMed

Ju, Liang; Cailin, Fang; Wenlan, Wu; Pinghua, Yu; Jiayu, Gao; Junbo, Li

2017-02-25

As a new kind of drug carries, pH-sensitive liposomes have been widely studied in tumor therapy for their advantages of target ability and sustained-release. Here, we synthesized a pH-sensitive material, N-(3-Aminopropyl)imidazole-cholesterol (IM-Chol) and prepared a novel pH-sensitive liposomes using IM-Chol and phosphatidylcholine. IM-Chol was synthesized through amidation reaction between the amino group of N-(3-Aminopropyl)imidazole and acyl chloride group of cholesteryl chloroformate in a weak base solution. Optimal conditions to prepare liposomes were obtained by the orthogonal experiment with the higher encapsulation efficiency as the evaluation indicator. The properties of liposomes, such as particle size, zeta potential, morphology, encapsulation efficiency, drug release behavior and in vitro cell toxicity were evaluated by transmission electron microscopy (TEM), dynamic light scattering (DLS) and MTT assay respectively. The results showed that the average particle size of IM-Chol liposomes was 141nm (PDI 0.323). Liposomes can assemble into uniform spheres at pH 7.4, but under the condition of pH 5.0, the spherical structure of IM-Chol liposomes was broken, exhibiting pH-sensitive property. In vitro drug releasing studies demonstrated the controlled-release behavior of the curcumin (CUR) in the IM-Chol liposomes. The cumulative release of CUR reached to 72.5% in the first 24h at pH 5.0, faster than that at pH 7.4, which confirmed that the drug carrier displayed pH-sensitive release behaviors. In addition, the MTT assay was employed to test the cytotoxicity of IM-Chol liposomes and CUR IM-Chol liposomes. All cell viabilities were greater than 80% after incubating for 24h, even up to the highest dose of 500mg/L, indicating that IM-Chol liposomes had good biocompatibility. The tumor inhibitory results towards EC109 cells of free CUR and CUR-loaded IM-Chol liposomes indicated that IM-Chol liposomes indeed enhanced the cell killing effect of CUR. These results

Enhanced Cytotoxicity of Folic Acid-Targeted Liposomes Co-Loaded with C6 Ceramide and Doxorubicin: In Vitro Evaluation on HeLa, A2780-ADR, and H69-AR Cells.

PubMed

Sriraman, Shravan Kumar; Pan, Jiayi; Sarisozen, Can; Luther, Ed; Torchilin, Vladimir

2016-02-01

Current research in cancer therapy is beginning to shift toward the use of combinational drug treatment regimens. However, the efficient delivery of drug combinations is governed by a number of complex factors in the clinical setting. Therefore, the ability to synchronize the pharmacokinetics of the individual therapeutic agents present in combination not only to allow for simultaneous tumor accumulation but also to allow for a synergistic relationship at the intracellular level could prove to be advantageous. In this work, we report the development of a novel folic acid-targeted liposomal formulation simultaneously co-loaded with C6 ceramide and doxorubicin [FA-(C6+Dox)-LP]. In vitro cytotoxicity assays showed that the FA-(C6+Dox)-LP was able to significantly reduce the IC50 of Dox when compared to that after the treatment with the doxorubicin-loaded liposomes (Dox-LP) as well as the untargeted drug co-loaded (C6+Dox)-LP on HeLa, A2780-ADR, and H69-AR cells. The analysis of the cell cycle distribution showed that while the C6 liposomes (C6-LP) did not cause cell cycle arrest, all the Dox-containing liposomes mediated cell cycle arrest in HeLa cells in the G2 phase at Dox concentrations of 0.3 and 1 μM and in the S phase at the higher concentrations. It was also found that this arrest in the S phase precedes the progression of the cells to apoptosis. The targeted FA-(C6+Dox)-LP were able to significantly enhance the induction of apoptotic events in HeLa cell monolayers as compared to the other treatment groups. Next, using time-lapse phase holographic imaging microscopy, it was found that upon treatment with the FA-(C6+Dox)-LP, the HeLa cells underwent rapid progression to apoptosis after 21 h as evidenced by a drastic drop in the average area of the cells after loss of cell membrane integrity. Finally, upon evaluation in a HeLa spheroid cell model, treatment with the FA-(C6+Dox)-LP showed significantly higher levels of cell death compared to those with C6-LP and

Hydrophobic Drug-Loaded PEGylated Magnetic Liposomes for Drug-Controlled Release

NASA Astrophysics Data System (ADS)

Hardiansyah, Andri; Yang, Ming-Chien; Liu, Ting-Yu; Kuo, Chih-Yu; Huang, Li-Ying; Chan, Tzu-Yi

2017-05-01

Less targeted and limited solubility of hydrophobic-based drug are one of the serious obstacles in drug delivery system. Thus, new strategies to enhance the solubility of hydrophobic drug and controlled release behaviors would be developed. Herein, curcumin, a model of hydrophobic drug, has been loaded into PEGylated magnetic liposomes as a drug carrier platform for drug controlled release system. Inductive magnetic heating (hyperthermia)-stimulated drug release, in vitro cellular cytotoxicity assay of curcumin-loaded PEGylated magnetic liposomes and cellular internalization-induced by magnetic guidance would be investigated. The resultant of drug carriers could disperse homogeneously in aqueous solution, showing a superparamagnetic characteristic and could inductive magnetic heating with external high-frequency magnetic field (HFMF). In vitro curcumin release studies confirmed that the drug carriers exhibited no significant release at 37 °C, whereas exhibited rapid releasing at 45 °C. However, it would display enormous (three times higher) curcumin releasing under the HFMF exposure, compared with that without HFMF exposure at 45 °C. In vitro cytotoxicity test shows that curcumin-loaded PEGylated magnetic liposomes could efficiently kill MCF-7 cells in parallel with increasing curcumin concentration. Fluorescence microscopy observed that these drug carriers could internalize efficiently into the cellular compartment of MCF-7 cells. Thus, it would be anticipated that the novel hydrophobic drug-loaded PEGylated magnetic liposomes in combination with inductive magnetic heating are promising to apply in the combination of chemotherapy and thermotherapy for cancer therapy.

Bupivacaine Versus Liposomal Bupivacaine For Pain Control.

PubMed

Beiranvand, Siavash; Moradkhani, Mahmoud Reza

2017-11-06

Local infiltrations and regional blocks have been some of the effective ways employed to manage and control post-operative pain. One of the limitations of administration of local anesthesia drugs in post-operative conditions is its inability to act for a longer period of time. Multi-vesicular liposomes made up of bupivacaine have been progressively used for their increased duration of action. Compared to bupivacaine HCL, local infiltration of liposomal bupivacaine have shown to have a significantly increase the duration and delay in peak plasma concentration. In this article, we attempt to compare liposomal bupivacaine and bupivacaine based on available clinical literatures. Liposomal bupivacaine has been demonstrated to have promising implications in post- operative pain control resulting in increased patient satisfaction; reduced hospital admission and opioid induced adverse events. Clinical studies have identified liposomal bupivacaine to be effective in delivering increased post-operative pain control. The purpose of this review is to give a comprehensive comparison between bupivacaine liposomal and conventional bupivacaine based on reported clinical trials. © Georg Thieme Verlag KG Stuttgart · New York.

General and programmable synthesis of hybrid liposome/metal nanoparticles

PubMed Central

Lee, Jin-Ho; Shin, Yonghee; Lee, Wooju; Whang, Keumrai; Kim, Dongchoul; Lee, Luke P.; Choi, Jeong-Woo; Kang, Taewook

2016-01-01

Hybrid liposome/metal nanoparticles are promising candidate materials for biomedical applications. However, the poor selectivity and low yield of the desired hybrid during synthesis pose a challenge. We designed a programmable liposome by selective encoding of a reducing agent, which allows self-crystallization of metal nanoparticles within the liposome to produce stable liposome/metal nanoparticles alone. We synthesized seven types of liposome/monometallic and more complex liposome/bimetallic hybrids. The resulting nanoparticles are tunable in size and metal composition, and their surface plasmon resonance bands are controllable in visible and near infrared. Owing to outer lipid bilayer, our liposome/Au nanoparticle shows better colloidal stability in biologically relevant solutions as well as higher endocytosis efficiency than gold nanoparticles without the liposome. We used this hybrid in intracellular imaging of living cells via surface-enhanced Raman spectroscopy, taking advantage of its improved physicochemical properties. We believe that our method greatly increases the utility of metal nanoparticles in in vivo applications. PMID:28028544

General and programmable synthesis of hybrid liposome/metal nanoparticles.

PubMed

Lee, Jin-Ho; Shin, Yonghee; Lee, Wooju; Whang, Keumrai; Kim, Dongchoul; Lee, Luke P; Choi, Jeong-Woo; Kang, Taewook

2016-12-01

Hybrid liposome/metal nanoparticles are promising candidate materials for biomedical applications. However, the poor selectivity and low yield of the desired hybrid during synthesis pose a challenge. We designed a programmable liposome by selective encoding of a reducing agent, which allows self-crystallization of metal nanoparticles within the liposome to produce stable liposome/metal nanoparticles alone. We synthesized seven types of liposome/monometallic and more complex liposome/bimetallic hybrids. The resulting nanoparticles are tunable in size and metal composition, and their surface plasmon resonance bands are controllable in visible and near infrared. Owing to outer lipid bilayer, our liposome/Au nanoparticle shows better colloidal stability in biologically relevant solutions as well as higher endocytosis efficiency than gold nanoparticles without the liposome. We used this hybrid in intracellular imaging of living cells via surface-enhanced Raman spectroscopy, taking advantage of its improved physicochemical properties. We believe that our method greatly increases the utility of metal nanoparticles in in vivo applications.

Liposomal nanomedicines.

PubMed

Fenske, David B; Cullis, Pieter R

2008-01-01

Liposomal nanoparticles (LNs) encapsulating therapeutic agents, or liposomal nanomedicines, represent an advanced class of drug delivery systems, with several formulations presently on the market and many more in clinical trials. Over the past 20 years, a variety of techniques have been developed for encapsulating both conventional drugs (such as anticancer drugs and antibiotics) and the new genetic drugs (plasmid DNA containing therapeutic genes, antisense oligonucleotides and small interfering RNA) within LNs. If the LNs possess certain properties, they tend to accumulate at sites of disease, such as tumours, where the endothelial layer is 'leaky' and allows extravasation of particles with small diameters. These properties include a diameter centred on 100 nm, a high drug-to-lipid ratio, excellent retention of the encapsulated drug, and a long (> 6 h) circulation lifetime. These properties permit the LNs to protect their contents during circulation, prevent contact with healthy tissues, and accumulate at sites of disease. The authors discuss recent advances in this field involving conventional anticancer drugs, as well as applications involving gene delivery, stimulation of the immune system and silencing of unwanted gene expression. Liposomal nanomedicines have the potential to offer new treatments in such areas as cancer therapy, vaccine development and cholesterol management.

Interaction of the alpha-toxin of Staphylococcus aureus with the liposome membrane.

PubMed

Ikigai, H; Nakae, T

1987-02-15

When the liposome membrane is exposed to the alpha-toxin of Staphylococcus aureus, fluorescence of the tryptophan residue(s) of the toxin molecule increases concomitantly with the degree of toxin-hexamer formation (Ikigai, H., and Nakae, T. (1985) Biochem. Biophys. Res. Commun. 130, 175-181). In the present study, the toxin-membrane interaction was distinguished from the hexamer formation by the fluorescence energy transfer from the tryptophan residue(s) of the toxin molecule to the dansylated phosphatidylethanolamine in phosphatidylcholine liposome. Measurement of these two parameters yielded the following results. The effect of the toxin concentration and phospholipid concentration on these two parameters showed first order kinetics. The effect of liposome size on the energy transfer and the fluorescence increment of the tryptophan residue(s) was only detectable in small liposomes. Under moderately acidic or basic conditions, the fluorescence energy transfer always preceded the fluorescence increment of the tryptophan residue(s). The fluorescence increment at 336 nm at temperatures below 20 degrees C showed a latent period, whereas the fluorescence energy transfer did not. These results were thought to indicate that when alpha-toxin damages the target membrane, the molecule interacts with the membrane first, and then undergoes oligomerization within the membrane.

Aerosolized liposomes with dipalmitoyl phosphatidylcholine enhance pulmonary insulin delivery.

PubMed

Chono, Sumio; Fukuchi, Rie; Seki, Toshinobu; Morimoto, Kazuhiro

2009-07-20

The pulmonary insulin delivery characteristics of liposomes were examined. Aerosolized liposomes containing insulin were administered into rat lungs and the enhancing effect on insulin delivery was evaluated by changes of plasma glucose levels. Liposomes with dipalmitoyl phosphatidylcholine (DPPC) enhanced pulmonary insulin delivery in rats, however, liposomes with dilauroyl, dimyristoyl, distearoyl or dioleoyl phosphatidylcholine did not. Liposomes with DPPC also enhanced the in vitro permeation of FITC dextran (Mw 4400, FD-4) through the calu-3 cell monolayer by reducing the transepithelial electrical resistance and did not harm lung tissues in rats. These findings suggest that liposomes with DPPC enhance pulmonary insulin delivery by opening the epithelial cell space in the pulmonary mucosa not mucosal cell damage. Liposomes with DPPC could be useful as a pulmonary delivery system for peptide and protein drugs.

Technetium-99m-labeled ceftizoxime loaded long-circulating and pH-sensitive liposomes used to identify osteomyelitis.

PubMed

Ferreira, Soraya Maria Zandim Maciel Dias; Domingos, Giselle Pires; Ferreira, Diego dos Santos; Rocha, Talita Guieiro Ribeiro; Serakides, Rogéria; de Faria Rezende, Cleuza Maria; Cardoso, Valbert Nascimento; Fernandes, Simone Odília Antunes; Oliveira, Mônica Cristina

2012-07-15

Osteomyelitis is an infectious disease located in the bone or bone marrow. Long-circulating and pH-sensitive liposomes containing a technetium-99m-labeled antibiotic, ceftizoxime, (SpHL-(99m)Tc-CF) were developed to identify osteomyelitis foci. Biodistribution studies and scintigraphic images of bone infection or non infection-bearing rats that had been treated with these liposomes were performed. A high accumulation in infectious foci and high values in the target-non target ratio could be observed. These results indicate the potential of SpHL-(99m)Tc-CF as a potential agent for the diagnosis of bone infections. Copyright © 2012 Elsevier Ltd. All rights reserved.

Pharmacokinetics and disposition of various drug loaded liposomes.

PubMed

Qian, Shuai; Li, Chenrui; Zuo, Zhong

2012-05-01

Due to great efforts in past 45 years, several liposomal products including two liposomal vaccine products have been commercialized and many more potential products are now under clinical trial stage. Although liposome has significantly reduced the toxicity of the drugs with improved or maintained the efficacy, its further development has been limited by its instabilities during preparation and storage, incompatibility with certain drugs, relative high cost of production and quality control as well as unspecified drug release time and sites in vivo. In vivo behaviors of liposomal drugs highly depend on their physiochemical properties including lipid composition, particle size, surface charge, surface modifications and the administrated dose as well as the route of administration. Based on the literature reports from the past two decades, the current review provided an updated summary of the key factors in liposomal preparations for clinical usage and its impact on the alternation of pharmacokinetic and disposition behaviors of drugs encapsulated in the liposome formulations. Clinical applications of liposomal preparation in anti-tumor agents, anti-infective agents as well as the macromolecules have been highlighted.

Application of long-circulating liposomes to cancer photodynamic therapy.

PubMed

Oku, N; Saito, N; Namba, Y; Tsukada, H; Dolphin, D; Okada, S

1997-06-01

Photodynamic therapy (PDT) as a cancer treatment is notable for its quite low side effects in comparison with those of chemotherapy and radiotherapy. However, the accumulation of porphyrin derivatives used in PDT into tumor tissues is rather low. Since long-circulating liposomes are known to accumulate passively into tumor tissues, we liposomalized a porphyrin derivative, benzoporphyrin derivative monoacid ring A (BPD-MA), and used these liposomes to investigate the usefulness of PDT for tumor-bearing mice. BPD-MA was liposomalized into glucuronate-modified liposomes, which are known to be long-circulating. These liposomes were injected i.v. into Balb/c mice bearing Meth A sarcoma, and tumor regression and survival time were monitored after irradiation with laser light. Tumor regression and complete curing of tumor (80% cure rate by the treatment with 6 mg/kg BPD-MA) were observed when long circulating liposomalized BPD-MA was injected and laser-irradiated. In contrast, only a 20% cure rate was obtained when the animals were treated with BPD-MA solution or BPD-MA entrapped in conventional liposomes. These results suggest that a long-circulating liposomal formulation of photo-sensitive agents is useful for PDT.

Liposome Technology for Industrial Purposes

PubMed Central

Wagner, Andreas; Vorauer-Uhl, Karola

2011-01-01

Liposomes, spherical vesicles consisting of one or more phospholipid bilayers, were first described in the mid 60s by Bangham and coworkers. Since then, liposomes have made their way to the market. Today, numerous lab scale but only a few large-scale techniques are available. However, a lot of these methods have serious limitations in terms of entrapment of sensitive molecules due to their exposure to mechanical and/or chemical stress. This paper summarizes exclusively scalable techniques and focuses on strengths, respectively, limitations in respect to industrial applicability. An additional point of view was taken to regulatory requirements concerning liposomal drug formulations based on FDA and EMEA documents. PMID:21490754

Indocyanine Green-Loaded Liposomes for Light-Triggered Drug Release.

PubMed

Lajunen, Tatu; Kontturi, Leena-Stiina; Viitala, Lauri; Manna, Moutusi; Cramariuc, Oana; Róg, Tomasz; Bunker, Alex; Laaksonen, Timo; Viitala, Tapani; Murtomäki, Lasse; Urtti, Arto

2016-06-06

Light-triggered drug delivery systems enable site-specific and time-controlled drug release. In previous work, we have achieved this with liposomes containing gold nanoparticles in the aqueous core. Gold nanoparticles absorb near-infrared light and release the energy as heat that increases the permeability of the liposomal bilayer, thus releasing the contents of the liposome. In this work, we replaced the gold nanoparticles with the clinically approved imaging agent indocyanine green (ICG). The ICG liposomes were stable at storage conditions (4-22 °C) and at body temperature, and fast near-infrared (IR) light-triggered drug release was achieved with optimized phospholipid composition and a 1:50 ICG-to-lipid molar ratio. Encapsulated small molecular calcein and FITC-dextran (up to 20 kDa) were completely released from the liposomes after light exposure for 15 s. Location of ICG in the PEG layer of the liposomes was simulated with molecular dynamics. ICG has important benefits as a light-triggering agent in liposomes: fast content release, improved stability, improved possibility of liposomal size control, regulatory approval to use in humans, and the possibility of imaging the in vivo location of the liposomes based on the fluorescence of ICG. Near-infrared light used as a triggering mechanism has good tissue penetration and safety. Thus, ICG liposomes are an attractive option for light-controlled and efficient delivery of small and large drug molecules.

Co-liposomes having anisamide tagged lipid and cholesteryl tryptophan trigger enhanced gene transfection in sigma receptor positive cells.

PubMed

Misra, Santosh K; Moitra, Parikshit; Kondaiah, Paturu; Bhattacharya, Santanu

2016-06-01

Selective gene transfection could be strategy of interest for reducing off-target gene expression and toxicity. In this respect, sigma receptors are found to be over-expressed in many human tumors and liposomal formulations with ability to target these sigma receptors may improve the transfection efficiency to a significant level. To this direction, six novel lipids have been synthesized with different hydrophobic segments such as a long hydrophobic chain or a cholesteryl group and L-tryptophan as the head group. Three of them, Lipid 1, 3 and 5 possessed cationic Me3N(+) moiety at the distal end. In contrast each of the other three Lipid 2, 4 and 6 possessed sigma receptor targeting anisamide group with no cationic charge. Mixing of cationic and anisamide counterparts of the same lipid in a molar ratio of 1:1 produced co-liposomes L-M-1 (Lipid 1+2), L-M-2 (Lipid 3+4) and L-M-3 (Lipid 5+6). These co-liposomes, while keeping the sigma targeting anisamide tag intact, showed good DNA binding and release which were optimized from EB intercalation and gel electrophoresis assays. Inclusion of a zwitterionic, fusogenic natural lipid, DOPE, into the co-liposomes further improved the binding efficiencies of the lipid mixtures with DNA. These co-liposomes having cationic and anisamide lipids and DOPE were highly selective toward sigma positive HEK293 and HEK293T cells compared to the sigma negative HeLa cells. As evidenced from both FACS and luciferase assay, a lipid mixture comprising Lipid 3, 4 and DOPE in a molar ratio of 1:1:1 (L-M-2D1) was the best for transfection of reporter pEGFP-C3 and functional pCEP4-p53 gene plasmids. Anisamide mediated sigma receptor selectivity was further probed by pre-incubating the transfecting cells with lipids possessing anisamide and by quantification of the un-transfected plasmid DNA. Also each formulation was highly non-toxic in the cell lines examined. Copyright © 2016. Published by Elsevier B.V.

Application of Various Types of Liposomes in Drug Delivery Systems

PubMed Central

Alavi, Mehran; Karimi, Naser; Safaei, Mohsen

2017-01-01

Liposomes, due to their various forms, require further exploration. These structures can deliver both hydrophilic and hydrophobic drugs for cancer, antibacterial, antifungal, immunomodulation, diagnostics, ophtalmica, vaccines, enzymes and genetic elements. Preparation of liposomes results in different properties for these systems. In addition, based on preparation methods, liposomes types can be unilamellar, multilamellar and giant unilamellar; however, there are many factors and difficulties that affect the development of liposome drug delivery structure. In the present review, we discuss some problems that impact drug delivery by liposomes. In addition, we discuss a new generation of liposomes, which is utilized for decreasing the limitation of the conventional liposomes. PMID:28507932

Imaging experimental intraabdominal abscesses with 99mTc-PEG liposomes and 99mTc-HYNIC IgG.

PubMed Central

Dams, E T; Reijnen, M M; Oyen, W J; Boerman, O C; Laverman, P; Storm, G; van der Meer, J W; Corstens, F H; van Goor, H

1999-01-01

abnormalities. In addition, the preferential localization of radiolabeled PEG liposomes holds promise for targeted delivery of liposome-encapsulated drugs. Images Figure 1. PMID:10203089

In vivo distribution and antitumor activity of heparin-stabilized doxorubicin-loaded liposomes.

PubMed

Han, Hee Dong; Lee, Aeri; Song, Chung Kil; Hwang, Taewon; Seong, Hasoo; Lee, Chong Ock; Shin, Byung Cheol

2006-04-26

The purpose of this study was to investigate the effect of heparin conjugation to the surface of doxorubicin (DOX)-loaded liposomes on the circulation time, biodistribution and antitumor activity after intravenous injection in murine B16F10 melanoma tumor-bearing mice. The heparin-conjugated liposomes (heparin-liposomes) were prepared by fixation of the negatively charged heparin to the positively charged liposomes. The existence of heparin on the liposomal surface was confirmed by measuring the changes in the particle size, zeta potential and heparin amount of the liposomes. The stability of the heparin-liposomes in serum was higher than that of the control liposomes, due to the heparin-liposomes being better protected from the adsorption of serum proteins. The DOX-loaded heparin-liposomes showed high drug levels for up to 64 h after the intravenous injection and the half-life of DOX was approximately 8.4- or 1.5-fold higher than that of the control liposomes or polyethyleneglycol-fixed liposomes (PEG-liposomes), respectively. The heparin-liposomes accumulated to a greater extent in the tumor than the control or PEG-liposomes as a result of their lower uptake by the reticuloendothelial system cells in the liver and spleen. In addition, the DOX-loaded heparin-liposomes retarded the growth of the tumor effectively compared with the control or PEG-liposomes. These results indicate the promising potential of heparin-liposomes as a new sterically stabilized liposomal delivery system for the enhancement of the therapeutic efficacy of chemotherapeutic agents.

Preparation, pharmacokinetics and tumour-suppressive activity of berberine liposomes.

PubMed

Wang, Xinghui; Wang, Qiong; Liu, Zhihui; Zheng, Xiao

2017-06-01

Berberine (BBR) has shown promising antitumour effects in vitro. However, intravenous administration of BBR solution is complicated by lethal adverse cardiovascular effects. The aim of this study was to prepare common and polyethylene glycol (PEG)-modified long-circulating BBR liposomes and evaluate their efficacy and safety as potential antitumour agents. Physiochemical properties of common and long-circulating BBR liposomes were characterized including particle size, Zeta potential and thermal stability. Pharmacokinetic and tissue distribution study of liposomal BBR was performed in rats and tumour-bearing nude mice, respectively. Antitumour efficacy and safety were observed in SGC-7901 tumour-xenografted mice. Berberine liposomes showed homogenous morphology, storage stability and sustained-releasing behaviour in vitro. BBR liposomes led to significantly increased circulation retention of BBR in comparison with BBR solution. In tumour-bearing mice, BBR liposomes selectively increased BBR concentrations in the liver, spleen, lung and tumour, while conferred lower distribution to the heart and kidney. Importantly, chronic administration of BBR liposomes proved effective and safe in suppressing the tumour growth in nude mice, especially the PEG-modified long-circulating liposomes. Our study suggested that BBR liposomes may provide a safe form of intravenous drug therapy for strengthening the antitumour effects of BBR. © 2017 Royal Pharmaceutical Society.

Liposome encapsulation of curcumin and resveratrol in combination reduces prostate cancer incidence in PTEN knockout mice.

PubMed

Narayanan, Narayanan K; Nargi, Dominick; Randolph, Carla; Narayanan, Bhagavathi A

2009-07-01

Increasing interest in the use of phytochemicals to reduce prostate cancer led us to investigate 2 potential agents, curcumin and resveratrol as preventive agents. However, there is concern about the bioavailability of these agents pertinent to the poor absorption and thereby limiting its clinical use. With the view to improve their bioavailability, we used the liposome encapsulated curcumin, and resveratrol individually and in combination in male B6C3F1/J mice. Further, we examined the chemopreventive effect of liposome encapsulated curcumin and resveratrol in combination in prostate-specific PTEN knockout mice. In vitro assays using PTEN-CaP8 cancer cells were performed to investigate the combined effects curcumin with resveratrol on (i) cell growth, apoptosis and cell cycle (ii) impact on activated p-Akt, cyclin D1, m-TOR and androgen receptor (AR) proteins involved in tumor progression. HPLC analysis of serum and prostate tissues showed a significant increase in curcumin level when liposome encapsulated curcumin coadministered with liposomal resveratrol (p < 0.001). Combination of liposomal forms of curcumin and resveratrol significantly decreased prostatic adenocarcinoma in vivo (p < 0.001). In vitro studies revealed that curcumin plus resveratrol effectively inhibit cell growth and induced apoptosis. Molecular targets activated due to the loss of phosphatase and tensin homolog (PTEN) including p-Akt, cyclin D1, mammalian target of rapamycin and AR were downregulated by these agents in combination. Findings from this study for the first time provide evidence on phytochemicals in combination to enhance chemopreventive efficacy in prostate cancer. These findings clearly suggest that phytochemicals in combination may reduce prostate cancer incidence due to the loss of the tumor suppressor gene PTEN.

Characterisation of gene delivery using liposomal bubbles and ultrasound

NASA Astrophysics Data System (ADS)

Koshima, Risa; Suzuki, Ryo; Oda, Yusuke; Hirata, Keiichi; Nomura, Tetsuya; Negishi, Yoichi; Utoguchi, Naoki; Kudo, Nobuki; Maruyama, Kazuo

2011-09-01

The combination of nano/microbubbles and ultrasound is a novel technique for a non-viral gene deliver. We have previously developed novel ultrasound sensitive liposomes (Bubble liposomes) which contain the ultrasound imaging gas perfluoropropane. In this study, Bubble liposomes were compared with cationic lipid (CL)-DNA complexes as potential gene delivery carriers into tumors in vivo. The delivery of genes by bubble liposomes depended on the intensity of the applied ultrasound. The transfection efficiency plateaued at 0.7 W/cm2 ultrasound intensity. Bubble liposomes efficiently transferred genes into cultured cells even when the cells were exposed to ultrasound for only 1 s. In addition, bubble liposomes were able to introduce the luciferase gene more effectively than CL-DNA complexes into mouse ascites tumor cells. We conclude that the combination of Bubble liposomes and ultrasound is a good method for gene transfer in vivo.

Liposomal bupivacaine and clinical outcomes.

PubMed

Tong, Yi Cai Isaac; Kaye, Alan David; Urman, Richard D

2014-03-01

In the multimodal approach to the management of postoperative pain, local infiltration and regional blocks have been increasingly utilized for pain control. One of the limitations of local anesthetics in the postoperative setting is its relatively short duration of action. Multivesicular liposomes containing bupivacaine have been increasingly utilized for their increased duration of action. Compared with bupivacaine HCl, local infiltration of liposomal bupivacaine has shown to have an increase in duration of action and causes delay in peak plasma concentration. In this article, we attempt to review the clinical literature surrounding liposomal bupivacaine and its evolving role in perioperative analgesia. This new bupivacaine formation may have promising implications in postoperative pain control, resulting in increased patient satisfaction and a decrease in both hospital stay and opioid-induced adverse events (AEs). Although more studies are needed, the preliminary clinical trials suggest that liposomal bupivacaine has predictable pharmacokinetics, a similar side effect profile compared with bupivacaine HCl, and is effective in providing increased postoperative pain control. Copyright © 2014 Elsevier Ltd. All rights reserved.

Method of encapsulating polyaminopolycarboxylic acid chelating agents in liposomes

DOEpatents

Rahman, Yueh Erh

1977-11-10

A method is provided for transferring a polyaminopolycarboxylic acid chelating agent across a cellular membrane by encapsulating the charged chelating agent within liposomes, which liposomes will be taken up by the cells, thereby transferring the chelating agent across the cellular membrane. The chelating agent is encapsulated within liposomes by drying a lipid mixture to form a thin film and wetting the lipid film with a solution containing the chelating agent. Mixing then results in the formation of a suspension of liposomes encapsulating the chelating agent, which liposomes can then be separated.

Liposomal adjuvant development for leishmaniasis vaccines.

PubMed

Askarizadeh, Anis; Jaafari, Mahmoud Reza; Khamesipour, Ali; Badiee, Ali

2017-08-01

Leishmaniasis is a parasitic disease that ranges in severity from skin lesions to fatality. Since long-lasting protection is induced upon recovery from cutaneous leishmaniasis, development of an effective vaccine is promising. However, there is no vaccine for use in humans yet. It seems limited efficacy in leishmaniasis vaccines is due to lack of an appropriate adjuvant or delivery system. Hence, the use of particulate adjuvants such as liposomes for effective delivery to the antigen presenting cells (APCs) is a valuable strategy to enhance leishmaniasis vaccine efficacy. The extraordinary versatility of liposomes because of their unique amphiphilic and biphasic nature allows for using antigens or immunostimulators within the core, on the surface or within the bilayer, and modulates both the magnitude and the T-helper bias of the immune response. In this review article, we attempt to summarize the role of liposomal adjuvants in the development of Leishmania vaccines and describe the main physicochemical properties of liposomes like phospholipid composition, surface charge, and particle size during formulation design. We also suggest potentially useful formulation strategies in order for future experiments to have a chance to succeed as liposomal vaccines against leishmaniasis.

Liposomal adjuvant development for leishmaniasis vaccines

PubMed Central

Askarizadeh, Anis; Jaafari, Mahmoud Reza; Khamesipour, Ali; Badiee, Ali

2017-01-01

Leishmaniasis is a parasitic disease that ranges in severity from skin lesions to fatality. Since long-lasting protection is induced upon recovery from cutaneous leishmaniasis, development of an effective vaccine is promising. However, there is no vaccine for use in humans yet. It seems limited efficacy in leishmaniasis vaccines is due to lack of an appropriate adjuvant or delivery system. Hence, the use of particulate adjuvants such as liposomes for effective delivery to the antigen presenting cells (APCs) is a valuable strategy to enhance leishmaniasis vaccine efficacy. The extraordinary versatility of liposomes because of their unique amphiphilic and biphasic nature allows for using antigens or immunostimulators within the core, on the surface or within the bilayer, and modulates both the magnitude and the T-helper bias of the immune response. In this review article, we attempt to summarize the role of liposomal adjuvants in the development of Leishmania vaccines and describe the main physicochemical properties of liposomes like phospholipid composition, surface charge, and particle size during formulation design. We also suggest potentially useful formulation strategies in order for future experiments to have a chance to succeed as liposomal vaccines against leishmaniasis. PMID:29201374

Modification of liposomal concentration in liposome/adenoviral complexes allows significant protection of adenoviral vectors from neutralising antibody, in vitro.

PubMed

Steel, Jason C; Cavanagh, Heather M A; Burton, Mark A; Dingwall, Daniel J; Kalle, Wouter H J

2005-06-01

Adenoviral vectors have been commonly used in gene therapy protocols, however the success of their use is often limited by the induction of host immunity to the vector. Following exposure to the adenoviral vector, adenoviral-specific neutralising antibodies are produced which limits further administration. This study examines the efficacy of complexing liposomes to adenovirus for the protection of the adenovirus from neutralising antibodies in an in vitro setting. Dimethyldioctadecylammonium bromide (DDAB)-dioleoyl-l-phosphatidylethanolamine (DOPE) liposomes were bound at varying concentrations to adenovirus to form AL complexes and tested these complexes' ability to prevent adenoviral neutralisation. It is shown that by increasing the concentration of liposomes in the adenoviral-liposome (AL) complexes we can increase the level of immuno-shielding afforded the adenovirus. It is also shown that the increase in liposomal concentration may lead to drawbacks such as increased cytotoxicity and reductions in expression levels.

Liposome-encapsulated actinomycin for cancer chemotherapy

DOEpatents

Rahman, Yueh-Erh; Cerny, Elizabeth A.

1976-01-01

An improved method is provided for chemotherapy of malignant tumors by injection of antitumor drugs. The antitumor drug is encapsulated within liposomes and the liposomes containing the encapsulated drug are injected into the body. The encapsulated drug penetrates into the tumor cells where the drug is slowly released and induces degeneration and death of the tumor cells, while any toxicity to the host body is reduced. Liposome encapsulation of actinomycin D has been found to be particularly effective in treating cancerous abdominal tumors, while drastically reducing the toxicity of actinomycin D to the host.

Cellular uptake and in vitro antitumor efficacy of composite liposomes for neutron capture therapy.

PubMed

Peters, Tanja; Grunewald, Catrin; Blaickner, Matthias; Ziegner, Markus; Schütz, Christian; Iffland, Dorothee; Hampel, Gabriele; Nawroth, Thomas; Langguth, Peter

2015-02-22

the Auger and conversion electrons produced in (157)Gd capture, the proximity of Gd-atoms to cellular DNA is a crucial factor for infliction of lethal damage. Furthermore, Gd-containing liposomes may be used as MRI contrast agents for diagnostic purposes and surveillance of tumor targeting, thus enabling a theranostic approach for tumor therapy.

Amelioration of renal ischaemia–reperfusion injury by liposomal delivery of curcumin to renal tubular epithelial and antigen-presenting cells

PubMed Central

Rogers, NM; Stephenson, MD; Kitching, AR; Horowitz, JD; Coates, PTH

2012-01-01

BACKGROUND AND PURPOSE Renal ischaemia–reperfusion (IR) injury is an inevitable consequence of renal transplantation, causing significant graft injury, increasing the risk of rejection and contributing to poor long-term graft outcome. Renal injury is mediated by cytokine and chemokine synthesis, inflammation and oxidative stress resulting from activation of the NF-κB pathway. EXPERIMENTAL APPROACH We utilized liposomal incorporation of a potent inhibitor of the NF-κB pathway, curcumin, to target delivery to renal tubular epithelial and antigen-presenting cells. Liposomes containing curcumin were administered before bilateral renal ischaemia in C57/B6 mice, with subsequent reperfusion. Renal function was assessed from plasma levels of urea and creatinine, 4 and 24 h after reperfusion. Renal tissue was examined for NF-κB activity and oxidative stress (histology, immunostaining) and for apoptosis (TUNEL). Cytokines and chemokines were measured by RT-PCR and Western blotting. KEY RESULTS Liposomal curcumin significantly improved serum creatinine, reduced histological injury and cellular apoptosis and lowered Toll-like receptor-4, heat shock protein-70 and TNF-α mRNA expression. Liposomal curcumin also reduced neutrophil infiltration and diminished inflammatory chemokine expression. Curcumin liposomes reduced intracellular superoxide generation and increased superoxide dismutase levels, decreased inducible NOS mRNA expression and 3-nitrotyrosine staining consistent with limitations in nitrosative stress and inhibited renal tubular mRNA and protein expression of thioredoxin-interacting protein. These actions of curcumin were mediated by inhibition of NF-κB, MAPK and phospho-S6 ribosomal protein. CONCLUSIONS AND IMPLICATIONS Liposomal delivery of curcumin promoted effective, targeted delivery of this non-toxic compound that provided cytoprotection via anti-inflammatory and multiple antioxidant mechanisms following renal IR injury. PMID:21745189

Enhanced fluorescence diffuse optical tomography with indocyanine green-encapsulating liposomes targeted to receptors for vascular endothelial growth factor in tumor vasculature.

PubMed

Zanganeh, Saeid; Xu, Yan; Hamby, Carl V; Backer, Marina V; Backer, Joseph M; Zhu, Quing

2013-12-01

To develop an indocyanine green (ICG) tracer with slower clearance kinetics, we explored ICG-encapsulating liposomes (Lip) in three different formulations: untargeted (Lip/ICG), targeted to vascular endothelial growth factor (VEGF) receptors (scVEGF-Lip/ICG) by the receptor-binding moiety single-chain VEGF (scVEGF), or decorated with inactivated scVEGF (inactive-Lip/ICG) that does not bind to VEGF receptors. Experiments were conducted with tumor-bearing mice that were placed in a scattering medium with tumors located at imaging depths of either 1.5 or 2.0 cm. Near-infrared fluorescence diffuse optical tomography that provides depth-resolved spatial distributions of fluorescence in tumor was used for the detection of postinjection fluorescent signals. All liposome-based tracers, as well as free ICG, were injected intravenously into mice in the amounts corresponding to 5 nmol of ICG/mouse, and the kinetics of increase and decrease of fluorescent signals in tumors were monitored. A signal from free ICG reached maximum at 15-min postinjection and then rapidly declined with t1/2 of ~20 min. The signals from untargeted Lip/ICG and inactive-Lip/ICG also reached maximum at 15-min postinjection, however, declined somewhat slower than free ICG with t1/2 of ~30 min. By contrast, a signal from targeted scVEGF-Lip/ICG grew slower than that of all other tracers, reaching maximum at 30-min postinjection and declined much slower than that of other tracers with t1/2 of ~90 min, providing a more extended observation window. Higher scVEGF-Lip/ICG tumor accumulation was further confirmed by the analysis of fluorescence on cryosections of tumors that were harvested from animals at 400 min after injection with different tracers.

Optimization and characterization of liposome formulation by mixture design.

PubMed

Maherani, Behnoush; Arab-tehrany, Elmira; Kheirolomoom, Azadeh; Reshetov, Vadzim; Stebe, Marie José; Linder, Michel

2012-02-07

This study presents the application of the mixture design technique to develop an optimal liposome formulation by using the different lipids in type and percentage (DOPC, POPC and DPPC) in liposome composition. Ten lipid mixtures were generated by the simplex-centroid design technique and liposomes were prepared by the extrusion method. Liposomes were characterized with respect to size, phase transition temperature, ζ-potential, lamellarity, fluidity and efficiency in loading calcein. The results were then applied to estimate the coefficients of mixture design model and to find the optimal lipid composition with improved entrapment efficiency, size, transition temperature, fluidity and ζ-potential of liposomes. The response optimization of experiments was the liposome formulation with DOPC: 46%, POPC: 12% and DPPC: 42%. The optimal liposome formulation had an average diameter of 127.5 nm, a phase-transition temperature of 11.43 °C, a ζ-potential of -7.24 mV, fluidity (1/P)(TMA-DPH)((¬)) value of 2.87 and an encapsulation efficiency of 20.24%. The experimental results of characterization of optimal liposome formulation were in good agreement with those predicted by the mixture design technique.

Liposomal bupivacaine for regional anesthesia.

PubMed

Uskova, Anna; O'Connor, Jessica E

2015-10-01

Using a regional block in a multimodal approach to postoperative analgesia management involves addressing, which local anesthetic and how much should be used to ensure adequate pain relief to reduce related morbidity and mortality. This article will review literature surrounding the recently approved formulation of slow release liposomal bupivacaine, define its proven benefits, and identify ongoing studies to further examine the utility of this novel formulation by various routes. Recent Phase II and III clinical trials have demonstrated the ability of liposomal bupivacaine to provide prolonged analgesia, maintain a high safety profile in therapeutic doses, and decrease opioid requirements when compared with placebo in local infiltration applications for up to 24 h. Between 24 and 72 h after study drug administration, there was minimal to no difference between EXPAREL and placebo treatments on mean pain intensity. Conventional bupivacaine or ropivacaine groups (current standard practice in many hospitals in the USA) were not compared. In addition, the analgesic efficacy, cost-effectiveness, and safety profile of liposomal bupivacaine has not thoroughly been studied in various standard clinical settings such as perineural, intrathecal, and epidural administration. Current published data do not provide superior clinical results for EXPAREL over conventional bupivacaine based upon the lack of adequately powered multicentered clinical trials with comparison groups. Further investigation is necessary to identify the analgesic efficacy and safety profile of liposomal bupivacaine versus standard local anesthetics and to define the optimal clinical indication for liposomal bupivacaine administration in regional anesthesia.

Liposomal curcumin and its application in cancer

PubMed Central

Lee, Robert J; Zhao, Ling

2017-01-01

Curcumin (CUR) is a yellow polyphenolic compound derived from the plant turmeric. It is widely used to treat many types of diseases, including cancers such as those of lung, cervices, prostate, breast, bone and liver. However, its effectiveness has been limited due to poor aqueous solubility, low bioavailability and rapid metabolism and systemic elimination. To solve these problems, researchers have tried to explore novel drug delivery systems such as liposomes, solid dispersion, microemulsion, micelles, nanogels and dendrimers. Among these, liposomes have been the most extensively studied. Liposomal CUR formulation has greater growth inhibitory and pro-apoptotic effects on cancer cells. This review mainly focuses on the preparation of liposomes containing CUR and its use in cancer therapy. PMID:28860764

Liposomal curcumin and its application in cancer.

PubMed

Feng, Ting; Wei, Yumeng; Lee, Robert J; Zhao, Ling

2017-01-01

Curcumin (CUR) is a yellow polyphenolic compound derived from the plant turmeric. It is widely used to treat many types of diseases, including cancers such as those of lung, cervices, prostate, breast, bone and liver. However, its effectiveness has been limited due to poor aqueous solubility, low bioavailability and rapid metabolism and systemic elimination. To solve these problems, researchers have tried to explore novel drug delivery systems such as liposomes, solid dispersion, microemulsion, micelles, nanogels and dendrimers. Among these, liposomes have been the most extensively studied. Liposomal CUR formulation has greater growth inhibitory and pro-apoptotic effects on cancer cells. This review mainly focuses on the preparation of liposomes containing CUR and its use in cancer therapy.

Assembly of the alpha-toxin-hexamer of Staphylococcus aureus in the liposome membrane.

PubMed

Ikigai, H; Nakae, T

1987-02-15

It has been shown that the access of the alpha-toxin of Staphylococcus aureus to the target membrane and assembly of the hexamer can be monitored independently by respectively measuring the fluorescence energy transfer from the tryptophan residue(s) of the toxin to the dansylated phosphatidylethanolamine in the liposome membrane and the fluorescence increment of the toxin at 336 nm (Ikigai, H., and Nakae, T., (1987) J. Biol. Chem. 262, 2150-2155). Measurement of these parameters under various conditions showed the following results: when phosphatidylcholine (PC) liposomes composed of saturated fatty acids were mixed with the toxin, the fluorescence energy transfer occurred below, at, and above the transition temperature of the lipid, but the change of fluorescence at 336 nm was never detectable; when PC-liposomes containing unsaturated fatty acids were used, both the fluorescence energy transfer and the fluorescence increment of 336 nm were observed. These results suggested that the toxin-membrane interaction occurs in PC-membranes containing saturated and/or unsaturated fatty acids and that the oligomerization occurs only in the presence of PC containing unsaturated fatty acid(s). This conclusion was supported by the results of quantitative determination of the toxin-hexamer assembly and leakage of carboxyfluorescein from PC-liposomes under conditions similar to the above.

Clinical Trials with Pegylated Liposomal Doxorubicin in the Treatment of Ovarian Cancer

PubMed Central

Pisano, Carmela; Cecere, Sabrina Chiara; Di Napoli, Marilena; Cavaliere, Carla; Tambaro, Rosa; Facchini, Gaetano; Losito, Simona; Pizzolorusso, Antonio; Pignata, Sandro

2013-01-01

Among the pharmaceutical options available for treatment of ovarian cancer, increasing attention has been progressively focused on pegylated liposomal doxorubicin (PLD), whose unique formulation prolongs the persistence of the drug in the circulation and potentiates intratumor accumulation. Pegylated liposomal doxorubicin (PLD) has become a major component in the routine management of epithelial ovarian cancer. In 1999 it was first approved for platinum-refractory ovarian cancer and then received full approval for platinum-sensitive recurrent disease in 2005. PLD remains an important therapeutic tool in the management of recurrent ovarian cancer in 2012. Recent interest in PLD/carboplatin combination therapy has been the object of phase III trials in platinum-sensitive and chemonaïve ovarian cancer patients reporting response rates, progressive-free survival, and overall survival similar to other platinum-based combinations, but with a more favorable toxicity profile and convenient dosing schedule. This paper summarizes data clarifying the role of pegylated liposomal doxorubicin (PLD) in ovarian cancer, as well as researches focusing on adding novel targeted drugs to this cytotoxic agent. PMID:23577259

Boron-Containing Compounds for Liposome-Mediated Tumor Localization and Application to Neutron Capture Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawthorne, M. Frederick

2005-04-07

Medical application of boron neutron capture therapy (BNCT) has been significantly hindered by the slow development of boron drug-targeting methodologies for the selective delivery of high boron concentration sto malignant cells. We have successfully sought to fill this need by creating liposomes suitable as in vivo boron delivery vehicles for BNCT. Delivery of therapeutic quantities of boron to tumors in murine models has been achieved with small unilamellar boron-rich liposomes. Subsequently, attempts have been made to improve delivery efficiency of liposomes encapsulating boron-containing water-soluble species into their hollow core by incorporating lipophilic boron compounds as addenda to the liposome bilayer,more » incorporating boron compounds as structural components of the bilayer (which however, poses the risk of sacrificing some stability), and combinations thereof. Regardless of the method, approximately 90% of the total liposome mass remains therapeutically inactive and comprised of the vehicle's construction materials, while less than 5% is boron for neutron targeting. Following this laboratory's intensive study, the observed tumor specificity of certain liposomes has been attributed to their diminutive size of these liposomes (30-150 nm), which enables these small vesicles to pass through the porous, immature vasculature of rapidly growing tumor tissue. We surmised that any amphiphilic nanoparticle of suitable size could possess some tumor selectivity. Consequently, the discovery of a very boron-rich nanoparticle delivery agent with biodistribution performance similar to unilamellar liposomes became one of our goals. Closomers, a new class of polyhedral borane derivatives, attracted us as an alternative BNCT drug-delivery system. We specifically envisioned dodeca (nido-carboranyl)-substituted closomers as possibly having a great potential role in BNCT drug delivery. They could function as extraordinarily boron-rich BNCT drugs since they are

Thermosensitive liposomes for localized delivery and triggered release of chemotherapy

PubMed Central

Ta, Terence; Porter, Tyrone M.

2016-01-01

Liposomes are a promising class of nanomedicine with the potential to provide site-specific chemotherapy, thus improving the quality of cancer patient care. First-generation liposomes have emerged as one of the first nanomedicines used clinically for localized delivery of chemotherapy. Second-generation liposomes, i.e. stimuli-responsive liposomes, have the potential to not only provide site-specific chemotherapy, but also triggered drug release and thus greater spatial and temporal control of therapy. Temperature-sensitive liposomes are an especially attractive option, as tumors can be heated in a controlled and predictable manner with external energy sources. Traditional thermosensitive liposomes are composed of lipids that undergo a gel-to-liquid phase transition at several degrees above physiological temperature. More recently, temperature-sensitization of liposomes has been demonstrated with the use of lysolipids and synthetic temperature-sensitive polymers. The design, drug release behavior, and clinical potential of various temperature-sensitive liposomes, as well as the various heating modalities used to trigger release, are discussed in this review. PMID:23583706

Overcoming cellular and tissue barriers to improve liposomal drug delivery

NASA Astrophysics Data System (ADS)

Kohli, Aditya G.

Forty years of liposome research have demonstrated that the anti-tumor efficacy of liposomal therapies is, in part, driven by three parameters: 1) liposome formulation and lipid biophysics, 2) accumulation and distribution in the tumor, and 3) release of the payload at the site of interest. This thesis outlines three studies that improve on each of these delivery steps. In the first study, we engineer a novel class of zwitterlipids with an inverted headgroup architecture that have remarkable biophysical properties and may be useful for drug delivery applications. After intravenous administration, liposomes accumulate in the tumor by the enhanced permeability and retention effect. However, the tumor stroma often limits liposome efficacy by preventing distribution into the tumor. In the second study, we demonstrate that depletion of hyaluronan in the tumor stroma improves the distribution and efficacy of DoxilRTM in murine 4T1 tumors. Once a liposome has distributed to the therapeutic site, it must release its payload over the correct timescale. Few facile methods exist to quantify the release of liposome therapeutics in vivo. In the third study, we outline and validate a simple, robust, and quantitative method for tracking the rate and extent of release of liposome contents in vivo. This tool should facilitate a better understanding of the pharmacodynamics of liposome-encapsulated drugs in animals. This work highlights aspects of liposome behavior that have prevented successful clinical translation and proposes alternative approaches to improve liposome drug delivery.

Skin whitening effect of linoleic acid is enhanced by liposomal formulations.

PubMed

Shigeta, Yasutami; Imanaka, Hiromichi; Ando, Hideya; Ryu, Atsuko; Oku, Naoto; Baba, Naomichi; Makino, Taketoshi

2004-04-01

Linoleic acid (LA) is known to have a whitening effect on hyperpigmented skin, and is encapsulated in liposomes for topical application because of its low solubility in aqueous solution, although the effect of liposomalization of LA on the whitening activity has not been evaluated. In the present study, we evaluated the effect of liposomalization on the whitening activity of LA by using LA in ethanol, hydrogel containing LA, and hydrogel containing liposomal LA towards the UV-stimulated hyperpigmented dorsal skin of brownish guinea pigs. The whitening effect was far greater for hydrogel containing liposomal LA (0.1% w/w as a final concentration of LA) than for free LA in ethanol or hydrogel containing LA. Next, the whitening effect of LA was examined with UV-stimulated hyperpigmented human upper arm skin by using a hydrogel containing liposomal LA (0.1% LA) and non-liposomal LA (3.0, 10.0% LA). Liposomal LA (0.1%) showed a whitening effect comparable to 10.0% non-liposomal LA and was far more effective than 3.0% non-liposomal LA. These results indicate that liposomal formulations are favorable for the transdermal application of LA.

Development and characterization of multilamellar liposomes containing pyridostigmine.

PubMed

Souza, Ana Carolina Moreira; Grabe-Guimarães, Andrea; Souza, Jacqueline; Botacim, Wallace Entringer; Almeida, Tamara Marine; Frézard, Fréderic Jean Georges; Silva Barcellos, Neila Márcia

2014-06-01

Pyridostigmine has cardioprotective activity in both free and liposomal forms. This study aimed to develop and characterize liposomal formulations of pyridostigmine. For this, a spectrophotometric ultraviolet (UV) analytical method, at 270 nm, was developed and validated to quantify liposomal pyridostigmine. The method was linear in ranges from 0.02 to 0.09 mg/mL. The accuracy of this method was determined intra- and inter-day; the results of coefficient of variation were of 1.73-2.72% and 0.32-2.32%, respectively. The accuracy ranged between 99.45% and 101.12%. The method has not changed by influence of liposomal matrix and demonstrated being able to quantify pyridostigmine in liposomes. Two liposomal multilamellar formulations were developed: a constituted by dystearoyl-phosphatidylcholine (DSPC) and cholesterol (CHOL) other by dioleil-phosphatidylcholine (DOPC) and CHOL. The encapsulation efficiency was determined as 23.4% and 15.4%, respectively. Analyses of size and release of pyridostigmine from the formulations were made and the results showed that the formulations are viable for future studies in vivo.

Interaction of dipalmitoyl phosphatidylcholine (DPPC) liposomes and insulin

NASA Astrophysics Data System (ADS)

Mady, Mohsen M.; Elshemey, Wael M.

2011-06-01

Insulin, a peptide that has been used for decades in the treatment of diabetes, has well-defined properties and delivery requirements. Liposomes, which are lipid bilayer vesicles, have gained increasing attention as drug carriers which reduce the toxicity and increase the pharmacological activity of various drugs. The molecular interaction between (uncharged lipid) dipalmitoyl phosphatidylcholine (DPPC) liposomes and insulin has been characterized by using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. The characteristic protein absorption band peaks, Amide I (at about 1660 cm-1) and Amide II band (at about 1546 cm-1) are potentially reduced in the liposome insulin complex. Wide-angle x-ray scattering measurements showed that the association of insulin with DPPC lipid of liposomes still maintains the characteristic DPPC diffraction peaks with almost no change in relative intensities or change in peak positions. The absence of any shift in protein peak positions after insulin being associated with DPPC liposomes indicates that insulin is successfully forming complex with DPPC liposomes with possibly no pronounced alterations in the structure of insulin molecule.

Imaging the urinary pathways in mice by liposomal indocyanine green.

PubMed

Portnoy, Emma; Nizri, Eran; Golenser, Jacob; Shmuel, Miriam; Magdassi, Shlomo; Eyal, Sara

2015-07-01

Intraoperative ureter identification can assist in the prevention of ureteral injury and consequently improve surgery outcomes. Our aim was to take advantage of the altered pharmacokinetics of liposomal indocyanine green (ICG), the only FDA-approved near-infrared (NIR) dye, for imaging of ureters during surgeries. ICG was passively adsorbed to liposomes. NIR whole mice body and isolated tissue imaging were used to study liposomal ICG properties vs. free ICG. In vivo, the urinary bladder could be clearly observed in most of the liposome-treated mice. Liposomal encapsulation of ICG enhanced ureteral emission up to 1.9 fold compared to free ICG (P<0.01). Increase in liposomal micropolarity and microviscosity and differential scanning calorimetry supported ICG localization within the liposomal bilayer. Our findings suggest that liposomal ICG could be utilized for ureteral imaging intra-operatively, thus potentially improving surgical outcomes. Iatrogenic ureteral injury is a serious complication of abdominal surgery and intra-operative recognition of the ureters is usually the best method of injury prevention. In this article, the authors developed liposomal indocyanine green, which could be excreted via the urinary system and investigated its in-vivo use in mice. Copyright © 2015 Elsevier Inc. All rights reserved.

Improved Antitumor Efficacy and Pharmacokinetics of Bufalin via PEGylated Liposomes

NASA Astrophysics Data System (ADS)

Yuan, Jiani; Zhou, Xuanxuan; Cao, Wei; Bi, Linlin; Zhang, Yifang; Yang, Qian; Wang, Siwang

2017-11-01

Bufalin was reported to show strong pharmacological effects including cardiotonic, antiviral, immune-regulation, and especially antitumor effects. The objective of this study was to determine the characterization, antitumor efficacy, and pharmacokinetics of bufalin-loaded PEGylated liposomes compared with bufalin entity, which were prepared by FDA-approved pharmaceutical excipients. Bufalin-loaded PEGylated liposomes and bufalin-loaded liposomes were prepared reproducibly with homogeneous particle size by the combination of thin film evaporation method and high-pressure homogenization method. Their mean particle sizes were 127.6 and 155.0 nm, mean zeta potentials were 2.24 and - 18.5 mV, and entrapment efficiencies were 76.31 and 78.40%, respectively. In vitro release profile revealed that the release of bufalin in bufalin-loaded PEGylated liposomes was slower than that in bufalin-loaded liposomes. The cytotoxicity of blank liposomes has been found within acceptable range, whereas bufalin-loaded PEGylated liposomes showed enhanced cytotoxicity to U251 cells compared with bufalin entity. In vivo pharmacokinetics indicated that bufalin-loaded PEGylated liposomes could extend or eliminate the half-life time of bufalin in plasma in rats. The results suggested that bufalin-loaded PEGylated liposomes improved the solubility and increased the drug concentration in plasma.

Nanoparticle-stabilized liposomes for pH-responsive gastric drug delivery.

PubMed

Thamphiwatana, Soracha; Fu, Victoria; Zhu, Jingying; Lu, Diannan; Gao, Weiwei; Zhang, Liangfang

2013-10-01

We report a novel pH-responsive gold nanoparticle-stabilized liposome system for gastric antimicrobial delivery. By adsorbing small chitosan-modified gold nanoparticles (diameter ~10 nm) onto the outer surface of negatively charged phospholipid liposomes (diameter ~75 nm), we show that at gastric pH the liposomes have excellent stability with limited fusion ability and negligible cargo releases. However, when the stabilized liposomes are present in an environment with neutral pH, the gold stabilizers detach from the liposomes, resulting in free liposomes that can actively fuse with bacterial membranes. Using Helicobacter pylori as a model bacterium and doxycycline as a model antibiotic, we demonstrate such pH-responsive fusion activity and drug release profile of the nanoparticle-stabilized liposomes. Particularly, at neutral pH the gold nanoparticles detach, and thus the doxycycline-loaded liposomes rapidly fuse with bacteria and cause superior bactericidal efficacy as compared to the free doxycycline counterpart. Our results suggest that the reported liposome system holds a substantial potential for gastric drug delivery; it remains inactive (stable) in the stomach lumen but actively interacts with bacteria once it reaches the mucus layer of the stomach where the bacteria may reside.

Tat peptide and hexadecylphosphocholine introduction into pegylated liposomal doxorubicin: An in vitro and in vivo study on drug cellular delivery, release, biodistribution and antitumor activity.

PubMed

Teymouri, Manouchehr; Badiee, Ali; Golmohammadzadeh, Shiva; Sadri, Kayvan; Akhtari, Javad; Mellat, Mostafa; Nikpoor, Amin Reza; Jaafari, Mahmoud Reza

2016-09-10

We have investigated the co-addition of hexadecylphosphocholine (HePC) and a Tat derived peptide (Tat), coupled to Maleimide-PEG2000-DSPE pegylated liposomal doxorubicin (PLD) in many respects, including drug and liposome cellular delivery, drug release, biodistribution, in vivo cell delivery and antitumor activity. The liposomes were HePC-free and -containing liposomes, from which liposomes with 25, 50, 100 and 200 numbers of Tat/liposome were prepared. Similarly, DiI-C18 (3)-model liposomes (DiI-L and DiI-HePC-L) were prepared. HePC and Tat increased cellular delivery of Dox and cytotoxicity in B16F0 melanoma and C26 colon carcinoma cells. Tat enhanced liposome-cell interaction and caused Dox burst release. HePC and Tat reduced the serum retention time of liposomal Dox, slightly and dramatically, respectively. In comparison, Tat-liposomes enhanced Dox delivery to liver and spleen cells 3h post-injection. Likewise, Dox content of these tissues and tumor was lower at 24h. The naïve liposomes retarded tumor growth more effectively and their related median survival time of the treated C26 bearing BALB/c mice was longer than those of Tat-liposomes (MST>45days versus MST<38days). Overall liposomes exhibiting sustained drug release and negligible cell interaction were more suitable delivery systems in targeting cancerous tumors and suppressing their growth. Copyright © 2016 Elsevier B.V. All rights reserved.

Hydrophobic drug concentration affects the acoustic susceptibility of liposomes.

PubMed

Nguyen, An T; Lewin, Peter A; Wrenn, Steven P

2015-04-01

The purpose of this study was to investigate the effect of encapsulated hydrophobic drug concentration on ultrasound-mediated leakage from liposomes. Studies have shown that membrane modifications affect the acoustic susceptibility of liposomes, likely because of changes in membrane packing. An advantage of liposome as drug carrier is its ability to encapsulate drugs of different chemistries. However, incorporation of hydrophobic molecules into the bilayer may cause changes in membrane packing, thereby affecting the release kinetics. Liposomes containing calcein and varying concentrations of papaverine, a hydrophobic drug, were exposed to 20 kHz, 2.2 Wcm(-2) ultrasound. Papaverine concentration was observed to affect calcein leakage although the effects varied widely based on liposome phase. For example, incorporation of 0.5mg/mL papaverine into Ld liposomes increased the leakage of hydrophilic encapsulants by 3× within the first minute (p=0.004) whereas the same amount of papaverine increased leakage by only 1.5× (p<0.0001). Papaverine was also encapsulated into echogenic liposomes and its concentration did not significantly affect calcein release rates, suggesting that burst release from echogenic liposomes is predictable regardless of encapsulants chemistry and concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

In vivo monitoring of liposomal release in tumours following ultrasound stimulation.

PubMed

Evjen, Tove J; Hagtvet, Eirik; Moussatov, Alexei; Røgnvaldsson, Sibylla; Mestas, Jean-Louis; Fowler, R Andrew; Lafon, Cyril; Nilssen, Esben A

2013-08-01

Dioeleoylphosphatidylethanolamine (DOPE)-based liposomes were recently reported as a new class of liposomes for ultrasound (US)-mediated drug delivery. The liposomes showed both high stability and in vitro US-mediated drug release (sonosensitivity). In the current study, in vivo proof-of-principle of US triggered release in tumoured mice was demonstrated using optical imaging. Confocal non-thermal US was used to deliver cavitation to tumours in a well-controlled manner. To detect in vivo release, the near infrared fluorochrome Al (III) Phthalocyanine Chloride Tetrasulphonic acid (AlPcS₄) was encapsulated into both DOPE-based liposomes and control liposomes based on hydrogenated soy phosphatidylcholine (HSPC). Encapsulation causes concentration dependent quenching of fluorescence that is recovered upon AlPcS₄ release from the liposomes. Exposure of tumours to US resulted in a significant increase in fluorescence in mice administered with DOPE-based liposomes, but no change in the mice treated with HSPC-based liposomes. Thus, DOPE-based liposomes showed superior sonosensitivity compared to HSPC-based liposomes in vivo. Copyright © 2012 Elsevier B.V. All rights reserved.

Liposomal temozolomide drug delivery using convection enhanced delivery.

PubMed

Nordling-David, Mirjam M; Yaffe, Roni; Guez, David; Meirow, Hadar; Last, David; Grad, Etty; Salomon, Sharona; Sharabi, Shirley; Levi-Kalisman, Yael; Golomb, Gershon; Mardor, Yael

2017-09-10

Even though some progress in diagnosis and treatment has been made over the years, there is still no definitive treatment available for Glioblastoma multiforme (GBM). Convection-enhanced delivery (CED), a continuous infusion-mediated pressure gradient via intracranial catheters, studied in clinical trials, enables in situ drug concentrations several orders of magnitude greater than those achieved by systemic administration. We hypothesized that the currently limited efficacy of CED could be enhanced by a liposomal formulation, thus achieving enhanced drug localization to the tumor site with minimal toxicity. We hereby describe a novel approach for treating GBM by CED of liposomes containing the known chemotherapeutic agent, temozolomide (TMZ). A new technique for encapsulating TMZ in hydrophilic (PEGylated) liposomes, characterized by nano-size (121nm), low polydispersity index (<0.13) and with near-neutral charge (-ʒ,0.2mV), has been developed. Co-infusion of PEGylated Gd-DTPA liposomes and TMZ-liposomes by CED in GBM bearing rats, resulted in enhanced tumor detection with longer residence time than free Gd-DTPA. Treatment of GBM-bearing rats with either TMZ solution or TMZ-liposomes resulted in greater tumor inhibition and significantly higher survival. However, the longer survival and smaller tumor volumes exhibited by TMZ liposomal treatment in comparison to TMZ in solution were insignificant (p<0.053); and only significantly lower edema volumes were observed. Thus, there are no clear-cut advantages to use a liposomal delivery system of TMZ via CED over a drug solution. Copyright © 2017 Elsevier B.V. All rights reserved.

Formulation, antileukemia mechanism, pharmacokinetics, and biodistribution of a novel liposomal emodin

PubMed Central

Wang, Tiechuang; Yin, Xiaodong; Lu, Yaping; Shan, Weiguang; Xiong, Subin

2012-01-01

Emodin is a multifunctional Chinese traditional medicine with poor water solubility. D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) is a pegylated vitamin E derivate. In this study, a novel liposomal-emodin-conjugating TPGS was formulated and compared with methoxypolyethyleneglycol 2000-derivatized distearoyl-phosphatidylethanolamine (mPEG2000–DSPE) liposomal emodin. TPGS improved the encapsulation efficiency and stability of emodin egg phosphatidylcholine/cholesterol liposomes. A high encapsulation efficiency of 95.2% ± 3.0%, particle size of 121.1 ± 44.9 nm, spherical ultrastructure, and sustained in vitro release of TPGS liposomal emodin were observed; these were similar to mPEG2000–DSPE liposomes. Only the zeta potential of −13.1 ± 2.7 mV was significantly different to that for mPEG2000–DSPE liposomes. Compared to mPEG2000–DSPE liposomes, TPGS liposomes improved the cytotoxicity of emodin on leukemia cells by regulating the protein levels of myeloid cell leukemia 1 (Mcl-1), B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein, which was further enhanced by transferrin. TPGS liposomes prolonged the circulation time of emodin in the blood, with the area under the concentration–time curve (AUC) 1.7 times larger than for free emodin and 0.91 times larger than for mPEG2000–DSPE liposomes. In addition, TPGS liposomes showed higher AUC for emodin in the lung and kidney than for mPEG2000–DSPE liposomes, and both liposomes elevated the amount of emodin in the heart. Overall, TPGS is a pegylated agent that could potentially be used to compose a stable liposomal emodin with enhanced therapeutics. PMID:22661889

PEGylated liposomal vancomycin: a glimmer of hope for improving treatment outcomes in MRSA pneumonia.

PubMed

Pumerantz, Andrew S

2012-12-01

Methicillin-resistant Staphylococcus aureus (MRSA) plays a significant role in the pandemic of multidrug resistant bacterial infections and is a major cause of hospital-acquired pneumonia. MRSA pneumonia carries a high morbidity and mortality rate especially in elderly diabetics with chronic kidney disease. S. aureus is highly virulent and successful respiratory pathogen. Vancomycin and linezolid are the only two antimicrobial agents FDA-approved to treat MRSA pneumonia. Standard vancomycin dosing is associated with high clinical failure rates and higher dosages are associated with increased nephrotoxicity. Pharmacokinetic and pharmacodynamic limitations are major contributors to poor outcomes with vancomycin. New agents are needed to improve treatment outcomes with MRSA pneumonia. Recently released antimicrobials with in vitro activity are not FDA-approved for treating MRSA pneumonia. Other novel agents are being investigated though none are in late-stage development. Pharmaceutical industry perception of low returns on investment, a Sisyphean regulatory environment, and obstacles to patentability have contributed to declining interest in both the development of novel antibiotics and the improvement of existing generic formulations. Despite decades of investigation into liposomal encapsulation as a drug delivery system that would increase efficacy and decrease toxicity, only liposomal amphotericin B and doxorubicin are commercially available. In this article, the pharmacokinetics and biodistribution of a novel PEGylated liposomal vancomycin formulation along with passive targeting and the enhanced permeability and retention effect of liposomal drug delivery; the pathogenesis of MRSA pneumonia; and recent patents of novel anti-MRSA agents, including inhalational liposomal vancomycin, are reviewed.

Liposomal-Encapsulated Stroma-Free Hemoglobin as a Potential Blood Substitute.

DTIC Science & Technology

1980-01-02

circulating life-time even further. If all liposomes are taken up by RE cells, then when 14C- inulin is administered i.v. encapsulated in liposomes one should...of inulin would result only when liposomes become leaky or decompose before being taken up by cells. If liposomes are not maximally stable, then after...some time any liposome which had not been taken-up by RE cells would have decomposed and the released inulin excreted. We have used these facts to

Characterization, stability and in-vivo distribution of asialofetuin glycopeptide incorporating DSPC/CHOL liposomes prepared by mild cholate incubation.

PubMed

Kallinteri, P; Liao, W Y; Antimisiaris, S G; Hwang, K H

2001-04-01

In this study, a small triantennary asialoglycopeptide of fetuin (A-F2) was used as a ligand to direct liposomes to hepatocytes. A-F2 was cleaved from asialofetuin, purified, conjugated with fatty acids and incorporated into pre-formed sonicated DSPC/Chol (2:1) liposomes. A mild cholate incubation method for incorporating the A-F2 ligand on pre-formed vesicles was used. In preliminary in vivo experiments 111In3+ encapsulated in A-F2/palmityl liposomes was seen to accumulate in the liver of mice significantly faster than when encapsulated in non-ligand bearing liposomes of the same lipid composition (studied before), justifying further investigation of this system. The presence of the A-F2/fatty acid conjugate in a functional form on the vesicle surface was confirmed by their reversible agglutination in the presence of Ricinus communis agglutinin (RCA120). Effects of ligand incorporation on the vesicle size distribution, z-potential, membrane integrity and stability were monitored. The results demonstrate that highest ligand incorporation was achieved when liposomes and ligand were co-incubated in the presence of 1 mM sodium cholate. Incorporation increased with the length of the fatty acid used for A-F2 conjugation. Ligand-bearing liposomes were demonstrated to be smaller in diameter (about 30%) with a more positive z-potential in comparison to control vesicles while ligand incorporation did not influence the liposome membrane integrity. The size of the ligand-incorporating vesicles was maintained after 24 hours of incubation in isotonic buffer, proving that the vesicles do not aggregate. Although the preliminary biodistribution results may suggest that ligand bearing liposomes are accumulating in the liver, further cell culture, in vivo distribution and especially liver fractionation studies are required in order to clarify the intrahepatic localization of these liposomes and the ability to target liver hepatocytes in vivo.

Rupture Pathway of Phosphatidylcholine Liposomes on Silicon Dioxide

PubMed Central

Reimhult, Erik; Kasemo, Bengt; Höök, Fredrik

2009-01-01

We have investigated the pathway by which unilamellar POPC liposomes upon adsorption undergo rupture and form a supported lipid bilayer (SLB) on a SiO2 surface. Biotinylated lipids were selectively incorporated in the outer monolayer of POPC liposomes to create liposomes with asymmetric lipid compositions in the outer and inner leaflets. The specific binding of neutravidin and anti-biotin to SLBs formed by liposome fusion, prior to and after equilibrated flip-flop between the upper and lower monolayers in the SLB, were then investigated. It was concluded that the lipids in the outer monolayer of the vesicle predominantly end up on the SLB side facing the SiO2 substrate, as demonstrated by having maximum 30–40% of lipids in the liposome outer monolayer orienting towards the bulk after forming the SLB. PMID:19468333