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Sample records for enzyme prodrug therapy

  1. Targeted enzyme prodrug therapies.

    PubMed

    Schellmann, N; Deckert, P M; Bachran, D; Fuchs, H; Bachran, C

    2010-09-01

    The cure of cancer is still a formidable challenge in medical science. Long-known modalities including surgery, chemotherapy and radiotherapy are successful in a number of cases; however, invasive, metastasized and inaccessible tumors still pose an unresolved and ongoing problem. Targeted therapies designed to locate, detect and specifically kill tumor cells have been developed in the past three decades as an alternative to treat troublesome cancers. Most of these therapies are either based on antibody-dependent cellular cytotoxicity, targeted delivery of cytotoxic drugs or tumor site-specific activation of prodrugs. The latter is a two-step procedure. In the first step, a selected enzyme is accumulated in the tumor by guiding the enzyme or its gene to the neoplastic cells. In the second step, a harmless prodrug is applied and specifically converted by this enzyme into a cytotoxic drug only at the tumor site. A number of targeting systems, enzymes and prodrugs were investigated and improved since the concept was first envisioned in 1974. This review presents a concise overview on the history and latest developments in targeted therapies for cancer treatment. We cover the relevant technologies such as antibody-directed enzyme prodrug therapy (ADEPT), gene-directed enzyme prodrug therapy (GDEPT) as well as related therapies such as clostridial- (CDEPT) and polymer-directed enzyme prodrug therapy (PDEPT) with emphasis on prodrug-converting enzymes, prodrugs and drugs.

  2. Prodrugs for Gene-Directed Enzyme-Prodrug Therapy (Suicide Gene Therapy)

    PubMed Central

    2003-01-01

    This review focuses on the prodrugs used in suicide gene therapy. These prodrugs need to satisfy a number of criteria. They must be efficient and selective substrates for the activating enzyme, and be metabolized to potent cytotoxins preferably able to kill cells at all stages of the cell cycle. Both prodrugs and their activated species should have good distributive properties, so that the resulting bystander effects can maximize the effectiveness of the therapy, since gene transduction efficiencies are generally low. A total of 42 prodrugs explored for use in suicide gene therapy with 12 different enzymes are discussed, particularly in terms of their physiocochemical properties. An important parameter in determining bystander effects generated by passive diffusion is the lipophilicity of the activated form, a property conveniently compared by diffusion coefficients (log P for nonionizable compounds and log D7 for compounds containing an ionizable centre). Many of the early antimetabolite-based prodrugs provide very polar activated forms that have limited abilities to diffuse across cell membranes, and rely on gap junctions between cells for their bystander effects. Several later studies have shown that more lipophilic, neutral compounds have superior diffusion-based bystander effects. Prodrugs of DNA alkylating agents, that are less cell cycle-specific than antimetabolites and more effective against noncycling tumor cells, appear in general to be more active prodrugs, requiring less prolonged dosing schedules to be effective. It is expected that continued studies to optimize the bystander effects and other properties of prodrugs and the activated species they generate will contribute to improvements in the effectiveness of suicide gene therapy. PMID:12686722

  3. Macrophage mediated PCI enhanced gene-directed enzyme prodrug therapy

    NASA Astrophysics Data System (ADS)

    Christie, Catherine E.; Zamora, Genesis; Kwon, Young J.; Berg, Kristian; Madsen, Steen J.; Hirschberg, Henry

    2015-03-01

    Photochemical internalization (PCI) is a photodynamic therapy-based approach for improving the delivery of macromolecules and genes into the cell cytosol. Prodrug activating gene therapy (suicide gene therapy) employing the transduction of the E. coli cytosine deaminase (CD) gene into tumor cells, is a promising method. Expression of this gene within the target cell produces an enzyme that converts the nontoxic prodrug, 5-FC, to the toxic metabolite, 5-fluorouracil (5-FU). 5-FC may be particularly suitable for brain tumors, because it can readily cross the bloodbrain barrier (BBB). In addition the bystander effect, where activated drug is exported from the transfected cancer cells into the tumor microenvironment, plays an important role by inhibiting growth of adjacent tumor cells. Tumor-associated macrophages (TAMs) are frequently found in and around glioblastomas. Monocytes or macrophages (Ma) loaded with drugs, nanoparticles or photosensitizers could therefore be used to target tumors by local synthesis of chemo attractive factors. The basic concept is to combine PCI, to enhance the ex vivo transfection of a suicide gene into Ma, employing specially designed core/shell NP as gene carrier.

  4. Enzyme Prodrug Therapy Engineered into Electrospun Fibers with Embedded Liposomes for Controlled, Localized Synthesis of Therapeutics.

    PubMed

    Chandrawati, Rona; Olesen, Morten T J; Marini, Thatiane C C; Bisra, Gurpal; Guex, Anne Géraldine; de Oliveira, Marcelo G; Zelikin, Alexander N; Stevens, Molly M

    2017-09-01

    Enzyme prodrug therapy (EPT) enables localized conversion of inert prodrugs to active drugs by enzymes. Performance of EPT necessitates that the enzyme remains active throughout the time frame of the envisioned therapeutic application. β-glucuronidase is an enzyme with historically validated performance in EPT, however it retains its activity in biomaterials for an insufficiently long period of time, typically not exceeding 7 d. Herein, the encapsulation of β-glucuronidase in liposomal subcompartments within poly(vinyl alcohol) electrospun fibers is reported, leading to the assembly of biocatalytically active materials with activity of the enzyme sustained over at least seven weeks. It is further shown that liposomes provide the highly beneficial stabilization of the enzyme when incubated in cell culture media. The assembled biocatalytic materials successfully produce antiproliferative drugs (SN-38) using externally administered prodrugs (SN-38-glucuronide) and effectively suppress cell proliferation, with envisioned utility in the design of cardiovascular grafts. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Neural stem cell-mediated enzyme/prodrug therapy for glioma: preclinical studies.

    PubMed

    Aboody, Karen S; Najbauer, Joseph; Metz, Marianne Z; D'Apuzzo, Massimo; Gutova, Margarita; Annala, Alexander J; Synold, Timothy W; Couture, Larry A; Blanchard, Suzette; Moats, Rex A; Garcia, Elizabeth; Aramburo, Soraya; Valenzuela, Valerie V; Frank, Richard T; Barish, Michael E; Brown, Christine E; Kim, Seung U; Badie, Behnam; Portnow, Jana

    2013-05-08

    High-grade gliomas are extremely difficult to treat because they are invasive and therefore not curable by surgical resection; the toxicity of current chemo- and radiation therapies limits the doses that can be used. Neural stem cells (NSCs) have inherent tumor-tropic properties that enable their use as delivery vehicles to target enzyme/prodrug therapy selectively to tumors. We used a cytosine deaminase (CD)-expressing clonal human NSC line, HB1.F3.CD, to home to gliomas in mice and locally convert the prodrug 5-fluorocytosine to the active chemotherapeutic 5-fluorouracil. In vitro studies confirmed that the NSCs have normal karyotype, tumor tropism, and CD expression, and are genetically and functionally stable. In vivo biodistribution studies demonstrated NSC retention of tumor tropism, even in mice pretreated with radiation or dexamethasone to mimic clinically relevant adjuvant therapies. We evaluated safety and toxicity after intracerebral administration of the NSCs in non-tumor-bearing and orthotopic glioma-bearing immunocompetent and immunodeficient mice. We detected no difference in toxicity associated with conversion of 5-fluorocytosine to 5-fluorouracil, no NSCs outside the brain, and no histological evidence of pathology or tumorigenesis attributable to the NSCs. The average tumor volume in mice that received HB1.F3.CD NSCs and 5-fluorocytosine was about one-third that of the average volume in control mice. On the basis of these results, we conclude that combination therapy with HB1.F3.CD NSCs and 5-fluorocytosine is safe, nontoxic, and effective in mice. These data have led to approval of a first-in-human study of an allogeneic NSC-mediated enzyme/prodrug-targeted cancer therapy in patients with recurrent high-grade glioma.

  6. Enzyme Prodrug Therapy Achieves Site-Specific, Personalized Physiological Responses to the Locally Produced Nitric Oxide

    PubMed Central

    2018-01-01

    Nitric oxide (NO) is a highly potent but short-lived endogenous radical with a wide spectrum of physiological activities. In this work, we developed an enzymatic approach to the site-specific synthesis of NO mediated by biocatalytic surface coatings. Multilayered polyelectrolyte films were optimized as host compartments for the immobilized β-galactosidase (β-Gal) enzyme through a screen of eight polycations and eight polyanions. The lead composition was used to achieve localized production of NO through the addition of β-Gal–NONOate, a prodrug that releases NO following enzymatic bioconversion. The resulting coatings afforded physiologically relevant flux of NO matching that of the healthy human endothelium. The antiproliferative effect due to the synthesized NO in cell culture was site-specific: within a multiwell dish with freely shared media and nutrients, a 10-fold inhibition of cell growth was achieved on top of the biocatalytic coatings compared to the immediately adjacent enzyme-free microwells. The physiological effect of NO produced via the enzyme prodrug therapy was validated ex vivo in isolated arteries through the measurement of vasodilation. Biocatalytic coatings were deposited on wires produced using alloys used in clinical practice and successfully mediated a NONOate concentration-dependent vasodilation in the small arteries of rats. The results of this study present an exciting opportunity to manufacture implantable biomaterials with physiological responses controlled to the desired level for personalized treatment. PMID:29570264

  7. Modular adeno-associated virus (rAAV) vectors used for cellular virus-directed enzyme prodrug therapy

    PubMed Central

    Hagen, Sven; Baumann, Tobias; Wagner, Hanna J.; Morath, Volker; Kaufmann, Beate; Fischer, Adrian; Bergmann, Stefan; Schindler, Patrick; Arndt, Katja M.; Müller, Kristian M.

    2014-01-01

    The pre-clinical and clinical development of viral vehicles for gene transfer increased in recent years, and a recombinant adeno-associated virus (rAAV) drug took center stage upon approval in the European Union. However, lack of standardization, inefficient purification methods and complicated retargeting limit general usability. We address these obstacles by fusing rAAV-2 capsids with two modular targeting molecules (DARPin or Affibody) specific for a cancer cell-surface marker (EGFR) while simultaneously including an affinity tag (His-tag) in a surface-exposed loop. Equipping these particles with genes coding for prodrug converting enzymes (thymidine kinase or cytosine deaminase) we demonstrate tumor marker specific transduction and prodrug-dependent apoptosis of cancer cells. Coding terminal and loop modifications in one gene enabled specific and scalable purification. Our genetic parts for viral production adhere to a standardized cloning strategy facilitating rapid prototyping of virus directed enzyme prodrug therapy (VDEPT). PMID:24457557

  8. Water-soluble benzodiazepine prodrug/enzyme combinations for intranasal rescue therapies.

    PubMed

    Siegel, Ronald A; Kapoor, Mamta; Cheryala, Narsihmulu; Georg, Gunda I; Cloyd, James C

    2015-08-01

    Benzodiazepines (BZDs), including diazepam (DZP) and midazolam (MDZ), are drugs of choice for rapid treatment of seizure emergencies. Current approved use of these drugs involves administration via either intravenous or rectal routes. The former requires trained medical personnel, while the latter is socially unacceptable for many patients and caregivers. In recent years, efforts have been made to formulate BZDs for nasal administration. Because of the low solubility of these molecules, organic vehicles have been used to solubilize the drugs in the nasal products under development. However, organic solvents are irritating, potentially resulting in injury to nasal tissue. Here we report preliminary studies supporting a strategy in which water-soluble BZD prodrugs and a suitable converting enzyme are coadministered in an aqueous vehicle. Diazepam and midazolam prodrugs were synthesized and were readily converted to their active forms by a protease from Aspergillus oryzae. Using a permeation assay based on monolayers of Madin-Darby canine kidney II-wild type cells, we found that enzymatically produced BZDs could be maintained at high degrees of supersaturation, enabling faster transport across the membrane than can be achieved using saturated solutions. This strategy not only obviates the need for organic solvents, but it also suggests more rapid absorption and earlier peak concentrations than can be otherwise achieved. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Two-step polymer- and liposome-enzyme prodrug therapies for cancer: PDEPT and PELT concepts and future perspectives.

    PubMed

    Scomparin, Anna; Florindo, Helena F; Tiram, Galia; Ferguson, Elaine L; Satchi-Fainaro, Ronit

    2017-09-01

    Polymer-directed enzyme prodrug therapy (PDEPT) and polymer enzyme liposome therapy (PELT) are two-step therapies developed to provide anticancer drugs site-selective intratumoral accumulation and release. Nanomedicines, such as polymer-drug conjugates and liposomal drugs, accumulate in the tumor site due to extravasation-dependent mechanism (enhanced permeability and retention - EPR - effect), and further need to cross the cellular membrane and release their payload in the intracellular compartment. The subsequent administration of a polymer-enzyme conjugate able to accumulate in the tumor tissue and to trigger the extracellular release of the active drug showed promising preclinical results. The development of polymer-enzyme, polymer-drug conjugates and liposomal drugs had undergone a vast advancement over the past decades. Several examples of enzyme mimics for in vivo therapy can be found in the literature. Moreover, polymer therapeutics often present an enzyme-sensitive mechanism of drug release. These nanomedicines can thus be optimal substrates for PDEPT and this review aims to provide new insights and stimuli toward the future perspectives of this promising combination. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Combination cancer therapy by hapten-targeted prodrug-activating enzymes and cytokines.

    PubMed

    Chuang, Kuo-Hsiang; Cheng, Chiu-Min; Roffler, Steve R; Lu, Yu-Lin; Lin, Shiu-Ru; Wang, Jaw-Yuan; Tzou, Wen-Shyong; Su, Yu-Cheng; Chen, Bing-Mae; Cheng, Tian-Lu

    2006-01-01

    Combination therapy can help overcome limitations in the treatment of heterogeneous tumors. In the current study, we examined whether multiple therapeutic agents could be targeted to anti-dansyl single-chain antibodies (DNS scFv) that were anchored on the plasma membrane of cancer cells. Functional DNS scFv could be stably expressed on CT-26 colon cancer cells both in vitro and in vivo. Dansyl moieties were covalently attached to recombinant beta-glucuronidase (betaG) and interleukin 2 (IL-2) via a flexible poly(ethylene glycol) linker to form DNS-PEG-betaG and DNS-PEG-IL-2 conjugates. The conjugates displayed enzymatic and splenocyte-stimulatory activities, respectively, that were similar to those of the unmodified proteins. The conjugates selectively bound CT-26 cells that expressed anti-DNS scFv (CT-26/DNS cells) but not CT-26 cells that expressed control scFv (CT-26/phOx cells). DNS-PEG-betaG preferentially activated a glucuronide prodrug (BHAMG) of p-hydroxy aniline mustard at CT-26/DNS cells in culture and accumulated in subcutaneous CT-26/DNS tumors after intravenous administration. Systemic administration of DNS-PEG-IL-2 or DNS-PEG-betaG and BHAMG significantly delayed the growth of CT-26/DNS but not control CT-26/phOx tumors. Combination treatment with DNS-PEG-betaG and BHAMG followed by DNS-PEG-IL-2 therapy significantly suppressed the growth of CT-26/DNS tumors as compared to either single-agent regimen. These results show that at least two DNS-modified therapeutic agents can be selectively delivered to DNS scFv receptors in vitro and in vivo, allowing combination therapy of DNS scFv-modified tumors.

  11. Virus-directed enzyme prodrug therapy and the assessment of the cytotoxic impact of some benzimidazole derivatives.

    PubMed

    Szewczuk, Michał; Boguszewska, Karolina; Żebrowska, Marta; Balcerczak, Ewa; Stasiak, Marta; Świątkowska, Maria; Błaszczak-Świątkiewicz, Katarzyna

    2017-07-01

    Virus-directed enzyme prodrug therapy is one of the major strategy of increasing cytotoxicity of bioreductive agents. This research intended to examine new selected benzimidazole derivatives as a substrate for nitroreductase, the enzyme involved in nitroreduction which is responsible to the production of cytotoxic metabolites. In this way, the selectivity and strength of cytotoxicity can be raised. The effect of benzimidazoles on virus transfected cells and non-virus transfected cells A549 cell line was established by Annexin V + propidium iodide test, western blot, and polymerase chain reaction analysis of specific pro- and anti-apoptotic proteins in the corresponding gene expression and additionally nitroreductase gene expression. Our results proved the pro-apoptotic properties of all tested compounds in normoxia and hypoxia, especially according to virused A549 cells where the time of exposition was reduced from 48 to 4 h. In this shorten period of time, the strongest activity was shown by N-oxide compounds with nitro-groups. The apoptosis was confirmed by generation of BAX gene and protein and reduction of BCL2 gene and protein.

  12. Enterolactone glucuronide and β-glucuronidase in antibody directed enzyme prodrug therapy for targeted prostate cancer cell treatment.

    PubMed

    Di, Yunyun; Ji, Shaoping; Wolf, Philipp; Krol, Ed S; Alcorn, Jane

    2017-08-01

    Evidence from preclinical and animal studies demonstrated an anticancer effect of flaxseed lignans, particularly enterolactone (ENL), against prostate cancer. However, extensive first-pass metabolism following oral lignan consumption results in their systemic availability primarily as glucuronic acid conjugates (ENL-Gluc) and their modest in vivo effects. To overcome the unfavorable pharmacokinetics and improve their effectiveness in prostate cancer, antibody-directed enzyme prodrug therapy (ADEPT) might offer a novel strategy to allow for restricted activation of ENL from circulating ENL-Gluc within the tumor environment. The anti-prostate-specific membrane antigen (PSMA) antibody D7 was fused with human β-glucuronidase (hβG) via a flexible linker. The binding property of the fusion construct, D7-hβG, against purified or cell surface PSMA was determined by flow cytometry and Octet Red 384 system, respectively, with a binding rate constant, K d, of 2.5 nM. The enzymatic activity of D7-hβG was first tested using the probe, 4-methylumbelliferone glucuronide. A 3.8-fold greater fluorescence intensity was observed at pH 4.5 at 2 h compared with pH 7.4. The ability of D7-hβG to activate ENL from ENL-Gluc was tested and detected using LC-MS/MS. Enhanced generation of ENL was observed with increasing ENL-Gluc concentrations and reached 3613.2 ng/mL following incubation with 100 μM ENL-Gluc at pH 4.5 for 0.5 h. D7-hβG also decreased docetaxel IC 50 value from 23 nM to 14.9 nM in C4-2 cells. These results confirmed the binding and activity of D7-hβG and additional in vitro investigation is needed to support the future possibility of introducing this ADEPT system to animal models.

  13. The potential of 5-fluorocytosine/cytosine deaminase enzyme prodrug gene therapy in an intrahepatic colon cancer model.

    PubMed

    Nyati, M K; Symon, Z; Kievit, E; Dornfeld, K J; Rynkiewicz, S D; Ross, B D; Rehemtulla, A; Lawrence, T S

    2002-07-01

    Colorectal cancer can metastasize to the liver, but remain liver confined for years. A critical step in developing treatments for intrahepatic cancer involves assessment in an orthotopic intrahepatic model. The purpose of this study was to develop a noninvasive intrahepatic tumor model to study the efficacy of 5-flucytosine/yeast cytosine deaminase (5FC/yCD)-based gene therapy for liver tumors. Luciferase expressing human colorectal carcinoma (HT-29luc) cells were generated by retroviral infection and implanted in the left liver lobe of nude mice. The bioluminescence was measured every week for a period of 1 month, then animals were killed and tumors were measured by calipers. After we found a correlation between photon counts and tumor size, animals were implanted with tumors composed of either 0%, 10%, or 100% yCD/HT-29luc cells, and treated with 5FC. Tumor bioluminescence was measured during treatment and tumor histology examined at the time of death. We found that 5FC caused significant regression of yCD expressing tumors. Furthermore, visible tumors at the time of death, which emitted little bioluminescence, contained little or no viable tumor. We then developed an adenoviral vector for yCD. Intraperitoneal administration of adenovirus containing yCD led to the production of yCD enzyme within intrahepatic tumors. These results suggest that (1) intrahepatic cancer responds to 5FC when cells express yCD; (2) the luciferin-luciferase system permits non-invasive real time imaging of viable intrahepatic cancer; and (3) this system can be used to carry out gene therapy experiments using yCD adenovirus.

  14. Radiolabelling of glycosylated MFE-23::CPG2 fusion protein (MFECP1) with 99mTc for quantitation of tumour antibody-enzyme localisation in antibody-directed enzyme pro-drug therapy (ADEPT).

    PubMed

    Francis, R J; Mather, S J; Chester, K; Sharma, S K; Bhatia, J; Pedley, R B; Waibel, R; Green, A J; Begent, R H J

    2004-08-01

    MFECP1 is a glycosylated recombinant fusion protein composed of MFE-23, a high-affinity anti-carcinoembryonic antigen (CEA) single chain Fv (scFv), fused to the enzyme carboxypeptidase G2 (CPG2), and has been constructed for use in antibody-directed enzyme pro-drug therapy (ADEPT). Radiolabelling of glycosylated MFECP1 with technetium-99m was developed for the purpose of determining tumour localisation of MFECP1 in a phase I ADEPT clinical study. The method used was 99mTc-carbonyl [99mTc(H2O)3(CO)3]+ (abbreviated to TcCO) mediated labelling of 99mTc to the hexahistidine (His) tag of MFECP1. MFECP1 fusion protein was labelled with TcCO under a variety of conditions, and this was shown to be a relatively simple and robust method. Tissue biodistribution was assessed in a CEA-expressing LS174T (human colon carcinoma) nude mouse xenograft model. Tissues were taken at 1, 4 and 6 h for assessment of distribution of radioactivity and for measurement of CPG2 enzyme levels. The amount of radioactivity retained by the tumour proved to be an accurate estimation of actual measured enzyme activity, indicating that this radiolabelling method does not appear to damage the antibody-antigen binding or the enzyme activity of MFECP1. However, correlation between CPG2 enzyme activity and measured radioactivity in liver, spleen and kidney was poor, indicating retention of radioactivity in non-tumour sites but loss of enzyme activity. The high retention of technetium radioisotope in normal tissues may limit the clinical applicability of this radiolabelling method for MFECP1; however, these results suggest that this technique does have applicability for measuring the biodistribution of His-tagged recombinant proteins.

  15. New Enzyme Prodrug and Methionine-Depletion Combination Therapy of Breast Cancer Designed for Effective Delivery to the Tumor

    DTIC Science & Technology

    2011-10-01

    effects since the drug is produced locally in the tumor and the pro drug concentration would be at a le- vel that would not affect cells in other tissues...Depletion Combination Therapy of Breast Cancer Designed for Effective Delivery to the Tumor Roger Harrison University of Oklahoma Norman, OK 73019 15...SEP 2010 - 14 SEP 2011Annual01-10-2011 Recombinant L-methioninase-annexin V and cytosine deaminase-annexin V fusion proteins have been produced in

  16. Ligand-conjugated mesoporous silica nanorattles based on enzyme targeted prodrug delivery system for effective lung cancer therapy

    SciTech Connect

    Sundarraj, Shenbagamoorthy, E-mail: sundarrajbu09@gmail.com; Thangam, Ramar; Department of Virology, King Institute of Preventive Medicine and Research, Guindy, Chennai 600 032, TN

    2014-03-15

    Epidermal growth factor receptor antibody (EGFRAb) conjugated silica nanorattles (SNs) were synthesized and used to develop receptor mediated endocytosis for targeted drug delivery strategies for cancer therapy. The present study determined that the rate of internalization of silica nanorattles was found to be high in lung cancer cells when compared with the normal lung cells. EGFRAb can specifically bind to EGFR, a receptor that is highly expressed in lung cancer cells, but is expressed at low levels in other normal cells. Furthermore, in vitro studies clearly substantiated that the cPLA{sub 2}α activity, arachidonic acid release and cell proliferation were considerablymore » reduced by pyrrolidine-2 loaded EGFRAb-SN in H460 cells. The cytotoxicity, cell cycle arrest and apoptosis were significantly induced by the treatment of pyrrolidine-2 loaded EGFRAb-SN when compared with free pyrrolidine-2 and pyrrolidine-2 loaded SNs in human non-small cell lung cancer cells. An in vivo toxicity assessment showed that silica nanorattles and EGFRAb-SN-pyrrolidine-2 exhibited low systemic toxicity in healthy Balb/c mice. The EGFRAb-SN-pyrrolidine-2 showed a much better antitumor activity (38%) with enhanced tumor inhibition rate than the pyrrolidine-2 on the non-small cell lung carcinoma subcutaneous model. Thus, the present findings validated the low toxicity and high therapeutic potentials of EGFRAb-SN-pyrrolidine-2, which may provide a convincing evidence of the silica nanorattles as new potential carriers for targeted drug delivery systems. - Highlights: • EGFRAb-SN developed for receptor-mediated Drug delivery system (DDS). • EGFRAb-SN-pyrrolidine-2 targeted DDS for cPLA2α inhibition in NSLC. • Study indicates EGFRAb-SN-pyrrolidine-2 as an efficient in target dug delivery carrier. • Study explains entire efficiency of EGFRAb-SN-pyrrolidine-2 in vitro and in vivo models.« less

  17. Genetically engineered theranostic mesenchymal stem cells for the evaluation of the anticancer efficacy of enzyme/prodrug systems.

    PubMed

    Nouri, Faranak Salman; Wang, Xing; Hatefi, Arash

    2015-02-28

    Over the past decade, various enzyme/prodrug systems such as thymidine kinase/ganciclovir (TK/GCV), yeast cytosine deaminase/5-fluorocytosine (yCD/5-FC) and nitroreductase/CB1954 (NTR/CB1954) have been used for stem cell mediated suicide gene therapy of cancer. Yet, no study has been conducted to compare and demonstrate the advantages and disadvantages of using one system over another. Knowing that each enzyme/prodrug system has its own strengths and weaknesses, we utilized mesenchymal stem cells (MSCs) as a medium to perform for the first time a comparative study that illustrated the impact of subtle differences among these systems on the therapeutic outcome. For therapeutic purposes, we first genetically modified MSCs to stably express a panel of four suicide genes including TK (TK007 and TK(SR39) mutants), yeast cytosine deaminase:uracil phosphoribosyltransferase (yCD:UPRT) and nitroreductase (NTR). Then, we evaluated the anticancer efficacies of the genetically engineered MSCs in vitro and in vivo by using SKOV3 cell line which is sensitive to all four enzyme/prodrug systems. In addition, all MSCs were engineered to stably express luciferase gene making them suitable for quantitative imaging and dose-response relationship studies in animals. Considering the limitations imposed by the prodrugs' bystander effects, our findings show that yCD:UPRT/5-FC is the most effective enzyme/prodrug system among the ones tested. Our findings also demonstrate that theranostic MSCs are a reliable medium for the side-by-side evaluation and screening of the enzyme/prodrug systems at the preclinical level. The results of this study could help scientists who utilize cell-based, non-viral or viral vectors for suicide gene therapy of cancer make more informed decisions when choosing enzyme/prodrug systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Genetically Engineered Theranostic Mesenchymal Stem Cells for the Evaluation of the Anticancer Efficacy of Enzyme/Prodrug Systems

    PubMed Central

    Nouri, Faranak Salman; Wang, Xing; Hatefi, Arash

    2015-01-01

    Over the past decade, various enzyme/prodrug systems such as thymidine kinase/ganciclovir (TK/GCV), yeast cytosine deaminase/5-fluorocytosine (yCD/5-FC) and nitroreductase/CB1954 (NTR/CB1954) have been used for stem cell mediated suicide gene therapy of cancer. Yet, no study has been conducted to compare and demonstrate the advantages and disadvantages of using one system over another. Knowing that each enzyme/prodrug system has its own strengths and weaknesses, we utilized mesenchymal stem cells (MSCs) as a medium to perform for the first time a comparative study that illustrated the impact of subtle differences among these systems on the therapeutic outcome. For therapeutic purposes, we first genetically modified MSCs to stably express a panel of four suicide genes including TK (TK007 and TKSR39 mutants), yeast cytosine deaminase: uracil phosphoribosyltransferase (yCD:UPRT) and nitroreductase (NTR). Then, we evaluated the anticancer efficacies of the genetically engineered MSCs in vitro and in vivo by using SKOV3 cell line which is sensitive to all four enzyme/prodrug systems. In addition, all MSCs were engineered to stably express luciferase gene making them suitable for quantitative imaging and dose-response relationship studies in animals. Considering the limitations imposed by the prodrugs’ bystander effects, our findings show that yCD:UPRT/5-FC is the most effective enzyme/prodrug system among the ones tested. Our findings also demonstrate that theranostic MSCs are a reliable medium for the side-by-side evaluation and screening of the enzyme/prodrug systems at the preclinical level. The results of this study could help scientists who utilize cell-based, non-viral or viral vectors for suicide gene therapy of cancer make more informed decisions when choosing enzyme/prodrug systems. PMID:25575867

  19. Lipid prodrug nanocarriers in cancer therapy.

    PubMed

    Mura, Simona; Bui, Duc Trung; Couvreur, Patrick; Nicolas, Julien

    2015-06-28

    Application of nanotechnology in the medical field (i.e., nanomedicine) plays an important role in the development of novel drug delivery methods. Nanoscale drug delivery systems can indeed be customized with specific functionalities in order to improve the efficacy of the treatments. However, despite the progresses of the last decades, nanomedicines still face important obstacles related to: (i) the physico-chemical properties of the drug moieties which may reduce the total amount of loaded drug; (ii) the rapid and uncontrolled release (i.e., burst release) of the encapsulated drug after administration and (iii) the instability of the drug in biological media where a fast transformation into inactive metabolites can occur. As an alternative strategy to alleviate these drawbacks, the prodrug approach has found wide application. The covalent modification of a drug molecule into an inactive precursor from which the drug will be freed after administration offers several benefits such as: (i) a sustained drug release (mediated by chemical or enzymatic hydrolysis of the linkage between the drug-moiety and its promoiety); (ii) an increase of the drug chemical stability and solubility and, (iii) a reduced toxicity before the metabolization occurs. Lipids have been widely used as building blocks for the design of various prodrugs. Interestingly enough, these lipid-derivatized drugs can be delivered through a nanoparticulate form due to their ability to self-assemble and/or to be incorporated into lipid/polymer matrices. Among the several prodrugs developed so far, this review will focus on the main achievements in the field of lipid-based prodrug nanocarriers designed to improve the efficacy of anticancer drugs. Gemcitabine (Pubchem CID: 60750); 5-fluorouracil (Pubchem CID: 3385); Doxorubicin (Pubchem CID: 31703); Docetaxel (Pubchem CID: 148124); Methotrexate (Pubchem CID: 126941); Paclitaxel (Pubchem CID: 36314). Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Combined enzyme/prodrug treatment by genetically engineered AT-MSC exerts synergy and inhibits growth of MDA-MB-231 induced lung metastases.

    PubMed

    Matuskova, Miroslava; Kozovska, Zuzana; Toro, Lenka; Durinikova, Erika; Tyciakova, Silvia; Cierna, Zuzana; Bohovic, Roman; Kucerova, Lucia

    2015-04-09

    Metastatic spread of tumor cells remains a serious problem in cancer treatment. Gene-directed enzyme/prodrug therapy mediated by tumor-homing genetically engineered mesenchymal stromal cells (MSC) represents a promising therapeutic modality for elimination of disseminated cells. Efficacy of gene-directed enzyme/prodrug therapy can be improved by combination of individual systems. We aimed to define the combination effect of two systems of gene therapy mediated by MSC, and evaluate the ability of systemically administered genetically engineered mesenchymal stromal cells to inhibit the growth of experimental metastases derived from human breast adenocarcinoma cells MDA-MB-231/EGFP. Human adipose tissue-derived mesenchymal stromal cells (AT-MSC) were retrovirally transduced with fusion yeast cytosine deaminase::uracil phosphoribosyltransferase (CD::UPRT) or with Herpes simplex virus thymidine kinase (HSVtk). Engineered MSC were cocultured with tumor cells in the presence of prodrugs 5-fluorocytosin (5-FC) and ganciclovir (GCV). Combination effect of these enzyme/prodrug approaches was calculated. SCID/bg mice bearing experimental lung metastases were treated with CD::UPRT-MSC, HSVtk-MSC or both in combination in the presence of respective prodrug(s). Treatment efficiency was evaluated by EGFP-positive cell detection by flow cytometry combined with real-time PCR quantification of human cells in mouse organs. Results were confirmed by histological and immunohistochemical examination. We demonstrated various extent of synergy depending on tested cell line and experimental setup. The strongest synergism was observed on breast cancer-derived cell line MDA-MB-231/EGFP. Systemic administration of CD::UPRT-MSC and HSVtk-MSC in combination with 5-FC and GCV inhibited growth of MDA-MB-231 induced lung metastases. Combined gene-directed enzyme/prodrug therapy mediated by MSC exerted synergic cytotoxic effect and resulted in high therapeutic efficacy in vivo.

  1. pH-sensitive pHluorins as a molecular sensor for in situ monitoring of enzyme-catalyzed prodrug activation.

    PubMed

    Liu, Hui; Cao, Xiaodan; Wang, Ping; Ma, Xingyuan

    2017-07-01

    This work examines the feasibility of using a pH-sensitive fluorescent protein as a molecular reporter for enzyme-catalyzed prodrug activation reaction. Specifically, a ratiometric pHluorins was examined for detection of the activity of horseradish peroxidase (HRP) for the activation of indole-3-acetic acid. The pHluorins and HRP were conjugated chemically, forming a biocatalyst with a self-reporting function. Results showed that the characteristic fluorescence intensity ratio of the conjugate shifted from 1.47 to 1.40 corresponding to the progress of the prodrug activation reaction. The effectiveness of applying the conjugate for inhibition of the growth of Bcap-37 cells was also demonstrated simultaneously with reaction monitoring. The results reveal a very promising approach to realizing in situ monitoring of enzyme activities based on pH shifting for enzyme-based prodrug therapy applications. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  2. Antitumor Synergism and Enhanced Survival with a Tumor Vasculature-Targeted Enzyme Prodrug System, Rapamycin, and Cyclophosphamide.

    PubMed

    Krais, John J; Virani, Needa; McKernan, Patrick H; Nguyen, Quang; Fung, Kar-Ming; Sikavitsas, Vassilios I; Kurkjian, Carla; Harrison, Roger G

    2017-09-01

    Mutant cystathionine gamma-lyase was targeted to phosphatidylserine exposed on tumor vasculature through fusion with Annexin A1 or Annexin A5. Cystathionine gamma-lyase E58N, R118L, and E338N mutations impart nonnative methionine gamma-lyase activity, resulting in tumor-localized generation of highly toxic methylselenol upon systemic administration of nontoxic selenomethionine. The described therapeutic system circumvents systemic toxicity issues using a novel drug delivery/generation approach and avoids the administration of nonnative proteins and/or DNA required with other enzyme prodrug systems. The enzyme fusion exhibits strong and stable in vitro binding with dissociation constants in the nanomolar range for both human and mouse breast cancer cells and in a cell model of tumor vascular endothelium. Daily administration of the therapy suppressed growth of highly aggressive triple-negative murine 4T1 mammary tumors in immunocompetent BALB/cJ mice and MDA-MB-231 tumors in SCID mice. Treatment did not result in the occurrence of negative side effects or the elicitation of neutralizing antibodies. On the basis of the vasculature-targeted nature of the therapy, combinations with rapamycin and cyclophosphamide were evaluated. Rapamycin, an mTOR inhibitor, reduces the prosurvival signaling of cells in a hypoxic environment potentially exacerbated by a vasculature-targeted therapy. IHC revealed, unsurprisingly, a significant hypoxic response (increase in hypoxia-inducible factor 1 α subunit, HIF1A) in the enzyme prodrug-treated tumors and a dramatic reduction of HIF1A upon rapamycin treatment. Cyclophosphamide, an immunomodulator at low doses, was combined with the enzyme prodrug therapy and rapamycin; this combination synergistically reduced tumor volumes, inhibited metastatic progression, and enhanced survival. Mol Cancer Ther; 16(9); 1855-65. ©2017 AACR . ©2017 American Association for Cancer Research.

  3. Theranostic reduction-sensitive gemcitabine prodrug micelles for near-infrared imaging and pancreatic cancer therapy

    NASA Astrophysics Data System (ADS)

    Han, Haijie; Wang, Haibo; Chen, Yangjun; Li, Zuhong; Wang, Yin; Jin, Qiao; Ji, Jian

    2015-12-01

    A biodegradable and reduction-cleavable gemcitabine (GEM) polymeric prodrug with in vivo near-infrared (NIR) imaging ability was reported. This theranostic GEM prodrug PEG-b-[PLA-co-PMAC-graft-(IR820-co-GEM)] was synthesized by ring-opening polymerization and ``click'' reaction. The as-prepared reduction-sensitive prodrug could self-assemble into prodrug micelles in aqueous solution confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In vitro drug release studies showed that these prodrug micelles were able to release GEM in an intracellular-mimicking reductive environment. These prodrug micelles could be effectively internalized by BxPC-3 pancreatic cancer cells, which were observed by confocal laser scanning microscopy (CLSM). Meanwhile, a methyl thiazolyl tetrazolium (MTT) assay demonstrated that this prodrug exhibited high cytotoxicity against BxPC-3 cells. The in vivo whole-animal near-infrared (NIR) imaging results showed that these prodrug micelles could be effectively accumulated in tumor tissue and had a longer blood circulation time than IR820-COOH. The endogenous reduction-sensitive gemcitabine prodrug micelles with the in vivo NIR imaging ability might have great potential in image-guided pancreatic cancer therapy.A biodegradable and reduction-cleavable gemcitabine (GEM) polymeric prodrug with in vivo near-infrared (NIR) imaging ability was reported. This theranostic GEM prodrug PEG-b-[PLA-co-PMAC-graft-(IR820-co-GEM)] was synthesized by ring-opening polymerization and ``click'' reaction. The as-prepared reduction-sensitive prodrug could self-assemble into prodrug micelles in aqueous solution confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In vitro drug release studies showed that these prodrug micelles were able to release GEM in an intracellular-mimicking reductive environment. These prodrug micelles could be effectively internalized by BxPC-3 pancreatic cancer cells, which

  4. Use of enzyme inhibitors to evaluate the conversion pathways of ester and amide prodrugs: a case study example with the prodrug ceftobiprole medocaril.

    PubMed

    Eichenbaum, Gary; Skibbe, Jennifer; Parkinson, Andrew; Johnson, Mark D; Baumgardner, Dawn; Ogilvie, Brian; Usuki, Etsuko; Tonelli, Fred; Holsapple, Jeff; Schmitt-Hoffmann, Anne

    2012-03-01

    An approach was developed that uses enzyme inhibitors to support the assessment of the pathways that are responsible for the conversion of intravenously administered ester and amide prodrugs in different biological matrices. The methodology was applied to ceftobiprole medocaril (BAL5788), the prodrug of the cephalosporin antibiotic, ceftobiprole. The prodrug was incubated in plasma, postmitochondrial supernatant fractions from human liver (impaired and nonimpaired), kidney, and intestine as well as erythrocytes, in the presence and absence of different enzyme inhibitors (acetylcholinesterase, pseudocholinesterase, retinyl palmitoyl hydrolase, serine esterases, amidases, and cholinesterase). Hydrolysis was rapid, extensive, and not dependent on the presence of β-nicotinamide-adenine dinucleotide phosphate (reduced form) in all matrices tested, suggesting the involvement of carboxylesterases but not P450 enzymes. Hydrolysis in healthy human plasma was rapid and complete and only partially inhibited in the presence of paraoxonase inhibitors or in liver from hepatic impaired patients, suggesting involvement of nonparaoxonase pathways. The results demonstrate the utility of this approach in confirming the presence of multiple conversion pathways of intravenously administered prodrugs and in the case of BAL5788 demonstrated that this prodrug is unlikely to be affected by genetic polymorphisms, drug interactions, or other environmental factors that might inhibit or induce the enzymes involved in its conversion. Copyright © 2011 Wiley Periodicals, Inc.

  5. Gelatin-encapsulated iron oxide nanoparticles for platinum (IV) prodrug delivery, enzyme-stimulated release and MRI.

    PubMed

    Cheng, Ziyong; Dai, Yunlu; Kang, Xiaojiao; Li, Chunxia; Huang, Shanshan; Lian, Hongzhou; Hou, Zhiyao; Ma, Pingan; Lin, Jun

    2014-08-01

    A facile method for transferring hydrophobic iron oxide nanoparticles (IONPs) from chloroform to aqueous solution via encapsulation of FITC-modified gelatin based on the hydrophobic-hydrophobic interaction is described in this report. Due to the existence of large amount of active groups such as amine groups in gelatin, the fluorescent labeling molecules of fluorescein isothiocyanate (FITC) and platinum (IV) prodrug functionalized with carboxylic groups can be conveniently conjugated on the IONPs. The nanoparticles carrying Pt(IV) prodrug exhibit good anticancer activities when the Pt(IV) complexes are reduced to Pt(II) in the intracellular environment, while the pure Pt(IV) prodrug only presents lower cytotoxicity on cancer cells. Meanwhile, fluorescence of FITC on the surface of nanoparticles was completely quenched due to the possible Förster Resonance Energy Transfer (FRET) mechanism and showed a fluorescence recovery after gelatin release and detachment from IONPs. Therefore FITC as a fluorescence probe can be used for identification, tracking and monitoring the drug release. In addition, adding pancreatic enzyme can effectively promote the gelatin release from IONPs owing to the degradation of gelatin. Noticeable darkening in magnetic resonance image (MRI) was observed at the tumor site after in situ injection of nanoparticles, indicating the IONPs-enhanced T2-weighted imaging. Our results suggest that the gelatin encapsulated Fe3O4 nanoparticles have potential applications in multi-functional drug delivery system for disease therapy, MR imaging and fluorescence sensor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. ALA-Butyrate prodrugs for Photo-Dynamic Therapy

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  7. PSMA-Specific Theranostic Nanoplex for Combination of TRAIL Gene and 5-FC Prodrug Therapy of Prostate Cancer

    PubMed Central

    Chen, Zhihang; Penet, Marie-France; Krishnamachary, Balaji; Banerjee, Sangeeta R.; Pomper, Martin G.; Bhujwalla, Zaver M.

    2015-01-01

    Metastatic prostate cancer causes significant morbidity and mortality and there is a critical unmet need for effective treatments. We have developed a theranostic nanoplex platform for combined imaging and therapy of prostate cancer. Our prostate-specific membrane antigen (PSMA) targeted nanoplex is designed to deliver plasmid DNA encoding tumor necrosis factor related apoptosis-inducing ligand (TRAIL), together with bacterial cytosine deaminase (bCD) as a prodrug enzyme. Nanoplex specificity was tested using two variants of human PC3 prostate cancer cells in culture and in tumor xenografts, one with high PSMA expression and the other with negligible expression levels. The expression of EGFP-TRAIL was demonstrated by fluorescence optical imaging and real-time PCR. Noninvasive 19F MR spectroscopy detected the conversion of the nontoxic prodrug 5-fluorocytosine (5-FC) to cytotoxic 5-fluorouracil (5-FU) by bCD. The combination strategy of TRAIL gene and 5-FC/bCD therapy showed significant inhibition of the growth of prostate cancer cells and tumors. These data demonstrate that the PSMA-specific theranostic nanoplex can deliver gene therapy and prodrug enzyme therapy concurrently for precision medicine in metastatic prostate cancer. PMID:26706476

  8. Investigation of alternative prodrugs for use with E. coli nitroreductase in 'suicide gene' approaches to cancer therapy.

    PubMed

    Bailey, S M; Knox, R J; Hobbs, S M; Jenkins, T C; Mauger, A B; Melton, R G; Burke, P J; Connors, T A; Hart, I R

    1996-12-01

    The most commonly employed 'suicide' gene/prodrug system used in cancer gene therapy is the herpes simplex virus thymidine kinase (HSVtk)/ganciclovir system. We have examined the efficacy of an alternative approach utilising the E. coli nitroreductase B enzyme with CB1954 and a variety of other prodrugs. V79 cells transfected with a nitroreductase expression vector were up to 770-fold more sensitive to CB1954 than control non-expressing cells. In general other prodrugs which were found by HPLC to act as substrates for purified E. coli nitroreductase also exhibited increased cytotoxicity against the nitroreductase-expressing cells, although this correlation was not absolute. In particular nitrofurazone (97-fold) and additional aromatic nitro-compounds (nine- to 50-fold) showed a large differential whereas the quinones and the antimetabolite, B-FU, were less effective (< three-fold). The results support the possibility of using nitroreductase and CB1954 for 'suicide gene' therapy and in addition suggest that alternative prodrugs, such as nitrofurazone, warrant further investigation in this novel approach.

  9. A polymeric colchicinoid prodrug with reduced toxicity and improved efficacy for vascular disruption in cancer therapy

    PubMed Central

    Crielaard, Bart J; van der Wal, Steffen; Lammers, Twan; Le, Huong Thu; Hennink, Wim E; Schiffelers, Raymond M; Storm, Gert; Fens, Marcel HAM

    2011-01-01

    Colchicinoids are very potent tubulin-binding compounds, which interfere with microtubule formation, giving them strong cytotoxic properties, such as cell mitosis inhibition and induction of microcytoskeleton depolymerization. While this makes them promising vascular disrupting agents (VDAs) in cancer therapy, their dose-limiting toxicity has prevented any clinical application for this purpose. Therefore, colchicinoids are considered attractive lead molecules for the development of novel vascular disrupting nanomedicine. In a previous study, a polymeric colchicinoid prodrug that showed favorable hydrolysis characteristics at physiological conditions was developed. In the current study, this polymeric colchicinoid prodrug was evaluated in vitro and in vivo for its toxicity and vascular disrupting potential. Cell viability studies with human umbilical vein endothelial cells, as an in vitro measure for colchicine activity, reflected the degradation kinetics of the prodrug accordingly. Upon intravenous treatment, in vivo, of B16F10 melanoma-bearing mice with colchicine or with the polymeric colchicinoid prodrug, apparent vascular disruption and consequent tumor necrosis was observed for the prodrug but not for free colchicine at an equivalent dose. Moreover, a five-times-higher dose of the prodrug was well tolerated, indicating reduced toxicity. These findings demonstrate that the polymeric colchicinoid prodrug has a substantially improved efficacy/toxicity ratio compared with that of colchicine, making it a promising VDA for cancer therapy. PMID:22114500

  10. The application of prodrug-based nano-drug delivery strategy in cancer combination therapy.

    PubMed

    Ge, Yanxiu; Ma, Yakun; Li, Lingbing

    2016-10-01

    Single drug therapy that leads to the multidrug resistance of cancer cells and severe side-effect is a thing of the past. Combination therapies that affect multiple signaling pathways have been the focus of recent active research. Due to the successful development of prodrug-based nano-drug delivery systems (P-N-DDSs), their use has been extended to combination therapy as drug delivery platforms. In this review, we focus specifically on the P-N-DDSs in the field of combination therapy including the combinations of prodrugs with different chemotherapeutic agents, other therapeutic agents, nucleic acid or the combination of different types of therapy (e.g. chemotherapy and phototherapy). The relevant examples of prodrug-based nanoparticulate drug delivery strategy in combination cancer therapy from the recent literature are discussed to demonstrate the feasibilities of relevant technology. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Nanoassemblies from amphiphilic cytarabine prodrug for leukemia targeted therapy.

    PubMed

    Liu, Jing; Zhao, Dujuan; He, Wenxiu; Zhang, Huiyuan; Li, Zhonghao; Luan, Yuxia

    2017-02-01

    The anti-leukemia effect of cytarabine (Ara-C) is severely restricted by its high hydrophilic properties and rapid plasma degradation. Herein, a novel amphiphilic small molecular prodrug of Ara-C was developed by coupling a short aliphatic chain, hexanoic acid (HA) to 4-NH 2 of the parent drug. Based on the amphiphilic nature, the resulting bioconjugate (HA-Ara) could spontaneously self-assemble into stable spherical nanoassemblies (NAs) with an extremely high drug loading (∼71wt%). Moreover, folate receptor (FR)-targeting NAs with high grafting efficient folic acid - bovine serum albumin (FA-BSA) conjugate immobilized on the surface (NAs/FA-BSA) was prepared. The results of MTT assays on FR-positive K562 cells and FR-negative A549 cells demonstrated higher cytotoxicity of HA-Ara NAs than the native drug. Especially, the IC 50 values revealed that NAs/FA-BSA was 3 and 2-fold effective than non-targeted NAs after 24 and 48h treatment with K562 cells, respectively indicating FR-mediated enhanced anti-tumor efficacy. In vitro cellular uptake, larger accumulation of HA-Ara NAs were observed in comparative with the free FITC and the results further confirmed the selective uptake of NAs/FA-BSA in folate receptor enriched cancer cells. Above all, self-assembled HA-Ara NAs exhibited potential superiority for Ara-C delivery and FA-modified NAs would be an excellent candidate for targeting leukemia therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Amphipathic dextran-doxorubicin prodrug micelles for solid tumor therapy.

    PubMed

    Jin, Rong; Guo, Xuelian; Dong, Lingli; Xie, Enyuan; Cao, Aoneng

    2017-10-01

    A group of micelles self-assembled from deoxycholic acid-doxorubicin-conjugated dextran (denoted as Dex-DCA-DOX) prodrugs were designed and prepared for pH-triggered drug release and cancer chemotherapy. These prodrugs could be successfully produced by chemically coupling hydrophobic deoxycholic acid (DCA) to dextran hydrazine (denoted as Dex-NHNH 2 ) and hydrazone linker formation between doxorubicin (DOX) and Dex-NHNH 2 . These Dex-DCA-DOX prodrugs self-assembled to form micelles under physiological conditions with varied particle sizes depending on molecular weight of dextran, degree of substitution (DS) of DCA and DOX. After optimization, Dex10k-DCA9-DOX5.5 conjugate comprising dextran of 10kDa, DCA of DS 9 and DOX loading content of 5.5wt%, formed the micelles with the smallest size (110nm). These prodrug micelles could slowly liberate DOX under physiological conditions but efficiently released the drug at an acidified endosomal pH by the hydrolysis of acid-labile hydrazone linker. In vitro cytotoxicity experiment indicated that Dex10k-DCA9-DOX5.5 micelles exerted marked antitumor activity against MCF-7 and SKOV-3 cancer cells. Besides, intravenous administration of the micelles afforded growth inhibition of SKOV-3 tumor bearing in nude mice at a dosage of 2.5mg per kg with anti-cancer efficacy comparable to free DOX-chemotherapy but low systemic toxicity. This study highlights the feasibility of bio-safe and efficient dextran-based prodrug micelles designed for cancer chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Glutathione- and pH-responsive nonporous silica prodrug nanoparticles for controlled release and cancer therapy

    NASA Astrophysics Data System (ADS)

    Xu, Zhigang; Liu, Shiying; Kang, Yuejun; Wang, Mingfeng

    2015-03-01

    A myriad of drug delivery systems such as liposomes, micelles, polymers and inorganic nanoparticles (NPs) have been developed for cancer therapy. Very few of them, however, have the ability to integrate multiple functionalities such as specific delivery, high circulation stability, controllable release and good biocompatibility and biodegradability in a single system to improve the therapeutic efficacy. Herein, we report two types of stimuli-responsive nonporous silica prodrug NPs towards this goal for controlled release of anticancer drugs and efficient combinatorial cancer therapy. As a proof of concept, anticancer drugs camptothecin (CPT) and doxorubicin (DOX) were covalently encapsulated into silica matrices through glutathione (GSH)-responsive disulfide and pH-responsive hydrazone bonds, respectively, resulting in NPs with sizes tunable in the range of 50-200 nm. Both silica prodrug NPs showed stimuli-responsive controlled release upon exposure to a GSH-rich or acidic environment, resulting in improved anticancer efficacy. Notably, two prodrug NPs simultaneously taken up by HeLa cells showed a remarkable combinatorial efficacy compared to free drug pairs. These results suggest that the stimuli-responsive silica prodrug NPs are promising anticancer drug carriers for efficient cancer therapy.A myriad of drug delivery systems such as liposomes, micelles, polymers and inorganic nanoparticles (NPs) have been developed for cancer therapy. Very few of them, however, have the ability to integrate multiple functionalities such as specific delivery, high circulation stability, controllable release and good biocompatibility and biodegradability in a single system to improve the therapeutic efficacy. Herein, we report two types of stimuli-responsive nonporous silica prodrug NPs towards this goal for controlled release of anticancer drugs and efficient combinatorial cancer therapy. As a proof of concept, anticancer drugs camptothecin (CPT) and doxorubicin (DOX) were

  14. Clinical Advances of Hypoxia-Activated Prodrugs in Combination With Radiation Therapy.

    PubMed

    Mistry, Ishna N; Thomas, Matthew; Calder, Ewen D D; Conway, Stuart J; Hammond, Ester M

    2017-08-01

    With the increasing incidence of cancer worldwide, the need for specific, effective therapies is ever more urgent. One example of targeted cancer therapeutics is hypoxia-activated prodrugs (HAPs), also known as bioreductive prodrugs. These prodrugs are inactive in cells with normal oxygen levels but in hypoxic cells (with low oxygen levels) undergo chemical reduction to the active compound. Hypoxia is a common feature of solid tumors and is associated with a more aggressive phenotype and resistance to all modes of therapy. Therefore, the combination of radiation therapy and bioreductive drugs presents an attractive opportunity for synergistic effects, because the HAP targets the radiation-resistant hypoxic cells. Hypoxia-activated prodrugs have typically been precursors of DNA-damaging agents, but a new generation of molecularly targeted HAPs is emerging. By targeting proteins associated with tumorigenesis and survival, these compounds may result in greater selectivity over healthy tissue. We review the clinical progress of HAPs as adjuncts to radiation therapy and conclude that the use of HAPs alongside radiation is vastly underexplored at the clinical level. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Utilization of peptide carrier system to improve intestinal absorption: targeting prolidase as a prodrug-converting enzyme

    NASA Technical Reports Server (NTRS)

    Bai, J. P.; Hu, M.; Subramanian, P.; Mosberg, H. I.; Amidon, G. L.

    1992-01-01

    The feasibility of targeting prolidase as a peptide prodrug-converting enzyme has been examined. The enzymatic hydrolysis by prolidase of substrates for the peptide transporter L-alpha-methyldopa-pro and several dipeptide analogues without an N-terminal alpha-amino group (phenylpropionylproline, phenylacetylproline, N-benzoylproline, and N-acetylproline) was investigated. The Michaelis-Menten parameters Km and Vmax for L-alpha-methyldopa-pro are 0.09 +/- 0.02 mM and 3.98 +/- 0.25 mumol/min/mg protein, respectively. However, no hydrolysis of the dipeptide analogues without an N-terminal alpha-amino group is observed, suggesting that an N-terminal alpha-amino group is required for prolidase activity. These results demonstrate that prolidase may serve as a prodrug-converting enzyme for the dipeptide-type prodrugs, utilizing the peptide carrier for transport of prodrugs into the mucosal cells and prolidase, a cytosolic enzyme, to release the drug. However, a free alpha-amino group appears to be necessary for prolidase hydrolysis.

  16. Effect of alginate microencapsulation on the catalytic efficiency and in vitro enzyme-prodrug therapeutic efficacy of cytosine deaminase and of recombinant E. coli expressing cytosine deaminase.

    PubMed

    Funaro, Michael G; Nemani, Krishnamurthy V; Chen, Zhihang; Bhujwalla, Zaver M; Griswold, Karl E; Gimi, Barjor

    2016-02-01

    Cytosine deaminase (CD) catalyses the enzymatic conversion of the non-toxic prodrug 5-fluorocytosine (5-FC) to the potent chemotherapeutic form, 5-fluorouracil (5-FU). Intratumoral delivery of CD localises chemotherapy dose while reducing systemic toxicity. Encapsulation in biocompatible microcapsules immunoisolates CD and protects it from degradation. We report on the effect of alginate encapsulation on the catalytic and functional activity of isolated CD and recombinant E. coli engineered to express CD (E. coli(CD)). Alginate microcapsules containing either CD or Escherichia coli(CD) were prepared using ionotropic gelation. Conversion of 5-FC to 5-FU was quantitated in unencapsulated and encapsulated CD/E. coli(CD) using spectrophotometry, with a slower rate of conversion observed following encapsulation. Both encapsulated CD/5-FC and E. coli(CD)/5-FC resulted in cell kill and reduced proliferation of 9 L rat glioma cells, which was comparable to direct 5-FU treatment. Our results show that encapsulation preserves the therapeutic potential of CD and E. coli(CD) is equally effective for enzyme-prodrug therapy.

  17. Platinum(iv) prodrug conjugated Pd@Au nanoplates for chemotherapy and photothermal therapy

    NASA Astrophysics Data System (ADS)

    Shi, Saige; Chen, Xiaolan; Wei, Jingping; Huang, Yizhuan; Weng, Jian; Zheng, Nanfeng

    2016-03-01

    Owing to the excellent near infrared (NIR) light absorption and efficient passive targeting toward tumor tissue, two-dimensional (2D) core-shell PEGylated Pd@Au nanoplates have great potential in both photothermal therapy and drug delivery systems. In this work, we successfully conjugate Pd@Au nanoplates with a platinum(iv) prodrug c,c,t-[Pt(NH3)2Cl2(O2CCH2CH2CO2H)2] to obtain a nanocomposite (Pd@Au-PEG-Pt) for combined photothermal-chemotherapy. The prepared Pd@Au-PEG-Pt nanocomposite showed excellent stability in physiological solutions and efficient Pt(iv) prodrug loading. Once injected into biological tissue, the Pt(iv) prodrug was easily reduced by physiological reductants (e.g. ascorbic acid or glutathione) into its cytotoxic and hydrophilic Pt(ii) form and released from the original nanocomposite, and the NIR laser irradiation could accelerate the release of Pt(ii) species. More importantly, Pd@Au-PEG-Pt has high tumor accumulation (29%ID per g), which makes excellent therapeutic efficiency at relatively low power density possible. The in vivo results suggested that, compared with single therapy the combined thermo-chemotherapy treatment with Pd@Au-PEG-Pt resulted in complete destruction of the tumor tissue without recurrence, while chemotherapy using Pd@Au-PEG-Pt without irradiation or photothermal treatment using Pd@Au-PEG alone did not. Our work highlights the prospects of a feasible drug delivery strategy of the Pt prodrug by using 2D Pd@Au nanoplates as drug delivery carriers for multimode cancer treatment.Owing to the excellent near infrared (NIR) light absorption and efficient passive targeting toward tumor tissue, two-dimensional (2D) core-shell PEGylated Pd@Au nanoplates have great potential in both photothermal therapy and drug delivery systems. In this work, we successfully conjugate Pd@Au nanoplates with a platinum(iv) prodrug c,c,t-[Pt(NH3)2Cl2(O2CCH2CH2CO2H)2] to obtain a nanocomposite (Pd@Au-PEG-Pt) for combined photothermal-chemotherapy. The

  18. Smart activatable and traceable dual-prodrug for image-guided combination photodynamic and chemo-therapy.

    PubMed

    Hu, Fang; Yuan, Youyong; Mao, Duo; Wu, Wenbo; Liu, Bin

    2017-11-01

    Activatable photosensitizers (PSs) and chemo-prodrugs are highly desirable for anti-cancer therapy to reduce systemic toxicity. However, it is difficult to integrate both together into a molecular probe for combination therapy due to the complexity of introducing PS, singlet oxygen quencher, chemo-drug, chemo-drug inhibitor and active linker at the same time. To realize activatable PS and chemo-prodrug combination therapy, we develop a smart therapeutic platform in which the chemo-prodrug serves as the singlet oxygen quencher for the PS. Specifically, the photosensitizing activity and fluorescence of the PS (TPEPY-SH) are blocked by the chemo-prodrug (Mitomycin C, MMC) in the probe. Meanwhile, the cytotoxicity of MMC is also inhibited by the electron-withdrawing acyl at the nitrogen position next to the linker. Upon glutathione activation, TPEPY-S-MMC can simultaneously release active PS and MMC for combination therapy. The restored fluorescence of TPEPY-SH is also used to report the activation for both PS and MMC as well as to guide the photodynamic therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Pancreatic enzyme replacement therapy.

    PubMed

    Layer, P; Keller, J; Lankisch, P G

    2001-04-01

    Malabsorption due to severe pancreatic exocrine insufficiency is one of the most important late features of chronic pancreatitis. Generally, steatorrhea is more severe and occurs several years prior to malabsorption of other nutrients because synthesis and secretion of lipase are impaired more rapidly, its intraluminal survival is shorter, and the lack of pancreatic lipase activity is not compensated for by nonpancreatic mechanisms. Patients suffer not only from nutritional deficiencies but also from increased nutrient delivery to distal intestinal sites, causing symptoms by profound alteration of upper gastrointestinal secretory and motor functions. Adequate nutrient absorption requires delivery of sufficient enzymatic activity into the duodenal lumen simultaneously with meal nutrients. The following recommendations are based on modern therapeutic concepts: 25,000 to 40,000 units of lipase per meal using pH-sensitive pancreatin microspheres, with dosage increases, compliance checks, and differential diagnosis in case of treatment failure. Still, in most patients, lipid digestion cannot be completely normalized by current standard therapy, and future developments are needed to optimize treatment.

  20. Engineering a prostate-specific membrane antigen-activated tumor endothelial cell prodrug for cancer therapy.

    PubMed

    Denmeade, Samuel R; Mhaka, Annastasiah M; Rosen, D Marc; Brennen, W Nathaniel; Dalrymple, Susan; Dach, Ingrid; Olesen, Claus; Gurel, Bora; Demarzo, Angelo M; Wilding, George; Carducci, Michael A; Dionne, Craig A; Møller, Jesper V; Nissen, Poul; Christensen, S Brøgger; Isaacs, John T

    2012-06-27

    Heterogeneous expression of drug target proteins within tumor sites is a major mechanism of resistance to anticancer therapies. We describe a strategy to selectively inhibit, within tumor sites, the function of a critical intracellular protein, the sarcoplasmic/endoplasmic reticulum calcium adenosine triphosphatase (SERCA) pump, whose proper function is required by all cell types for viability. To achieve targeted inhibition, we took advantage of the unique expression of the carboxypeptidase prostate-specific membrane antigen (PSMA) by tumor endothelial cells within the microenvironment of solid tumors. We generated a prodrug, G202, consisting of a PSMA-specific peptide coupled to an analog of the potent SERCA pump inhibitor thapsigargin. G202 produced substantial tumor regression against a panel of human cancer xenografts in vivo at doses that were minimally toxic to the host. On the basis of these data, a phase 1 dose-escalation clinical trial has been initiated with G202 in patients with advanced cancer.

  1. Co-delivery of doxorubicin and curcumin by pH-sensitive prodrug nanoparticle for combination therapy of cancer

    NASA Astrophysics Data System (ADS)

    Zhang, Yumin; Yang, Cuihong; Wang, Weiwei; Liu, Jinjian; Liu, Qiang; Huang, Fan; Chu, Liping; Gao, Honglin; Li, Chen; Kong, Deling; Liu, Qian; Liu, Jianfeng

    2016-02-01

    Ample attention has focused on cancer drug delivery via prodrug nanoparticles due to their high drug loading property and comparatively lower side effects. In this study, we designed a PEG-DOX-Cur prodrug nanoparticle for simultaneous delivery of doxorubicin (DOX) and curcumin (Cur) as a combination therapy to treat cancer. DOX was conjugated to PEG by Schiff’s base reaction. The obtained prodrug conjugate could self-assemble in water at pH 7.4 into nanoparticles (PEG-DOX NPs) and encapsulate Cur into the core through hydrophobic interaction (PEG-DOX-Cur NPs). When the PEG-DOX-Cur NPs are internalized by tumor cells, the Schiff’s base linker between PEG and DOX would break in the acidic environment that is often observed in tumors, causing disassembling of the PEG-DOX-Cur NPs and releasing both DOX and Cur into the nuclei and cytoplasma of the tumor cells, respectively. Compared with free DOX, free Cur, free DOX-Cur combination, or PEG-DOX NPs, PEG-DOX-Cur NPs exhibited higher anti-tumor activity in vitro. In addition, the PEG-DOX-Cur NPs also showed prolonged blood circulation time, elevated local drug accumulation and increased tumor penetration. Enhanced anti-tumor activity was also observed from the PEG-DOX-Cur-treated animals, demonstrating better tumor inhibitory property of the NPs. Thus, the PEG-DOX-Cur prodrug nanoparticle system provides a simple yet efficient approach of drug delivery for chemotherapy.

  2. Hyaluronic acid-coated, prodrug-based nanostructured lipid carriers for enhanced pancreatic cancer therapy.

    PubMed

    Lu, Zhihe; Su, Jingrong; Li, Zhengrong; Zhan, Yuzhu; Ye, Decai

    2017-01-01

    Gemcitabine (GEM) and Baicalein (BCL) are reported to have anti-tumor effects including pancreatic cancer. Hyaluronic acid (HA) can bind to over-expressed receptors in various kinds of cancer cells. The aim of this study is to develop prodrugs containing HA, BCL and GEM, and construct nanomedicine incorporate GEM and BCL in the core and HA on the surface. This system could target the cancer cells and co-deliver the drugs. GEM-stearic acid lipid prodrug (GEM-SA) and hyaluronic acid-amino acid-baicalein prodrug (HA-AA-BCL) were synthesized. Then, GEM and BCL prodrug-based targeted nanostructured lipid carriers (HA-GEM-BCL NLCs) were prepared by the nanoprecipitation technique. The in vitro cytotoxicity studies of the NLCs were evaluated on AsPC1 pancreatic cancer cell line. In vivo anti-tumor effects were observed on the murine-bearing pancreatic cancer model. HA-GEM-BCL NLCs were effective in entering pancreatic cancer cells over-expressing HA receptors, and showed cytotoxicity of tumor cells in vitro. In vivo study revealed significant tumor growth inhibition ability of HA-GEM-BCL NLCs in murine pancreatic cancer model. It could be concluded that HA-GEM-BCL NLCs could be featured as promising co-delivery, tumor-targeted nanomedicine for the treatment of cancers.

  3. Intestinal absorption and activation of decitabine amino acid ester prodrugs mediated by peptide transporter PEPT1 and enterocyte enzymes.

    PubMed

    Tao, Wenhui; Zhao, Dongyang; Sun, Mengchi; Wang, Ziyu; Lin, Bin; Bao, Yu; Li, Yingying; He, Zhonggui; Sun, Yinghua; Sun, Jin

    2018-04-25

    Decitabine (DAC), a potent DNA methyltransferase (DNMT) inhibitor, has a limited oral bioavailability. Its 5'-amino acid ester prodrugs could improve its oral delivery but the specific absorption mechanism is not yet fully understood. The aim of this present study was to investigate the in vivo absorption and activation mechanism of these prodrugs using in situ intestinal perfusion and pharmacokinetics studies in rats. Although PEPT1 transporter is pH dependent, there appeared to be no proton cotransport in the perfusion experiment with a preferable transport at pH 7.4 rather than pH 6.5. This suggested that the transport was mostly dependent on the dissociated state of the prodrugs and the proton gradient might play only a limited role. In pH 7.4 HEPES buffer, an increase in P eff was observed for L-val-DAC, D-val-DAC, L-phe-DAC and L-trp-DAC (2.89-fold, 1.2-fold, 2.73-fold, and 1.90-fold, respectively), compared with the parent drug. When co-perfusing the prodrug with Glysar, a known substrate of PEPT1, the permeabilities of the prodrugs were significantly inhibited compared with the control. To further investigate the absorption of the prodrugs, L-val-DAC was selected and found to be concentration-dependent and saturable, suggesting a carrier-mediated process (intrinsic K m : 7.80 ± 2.61 mM) along with passive transport. Determination of drug in intestinal homogenate after perfusion further confirmed that the metabolic activation mainly involved an intestinal first-pass effect. In a pharmacokinetic evaluation, the oral bioavailability of L-val-DAC, L-phe-DAC and L-trp-DAC were nearly 1.74-fold, 1.69-fold and 1.49-fold greater than that of DAC. The differences in membrane permeability and oral bioavailability might be due to the different stability in the intestinal lumen and the distinct PEPT1 affinity which is mainly caused by the stereochemistry, hydrophobicity and steric hindrance of the side chains. In summary, the detailed investigation of the

  4. Clearance mechanism of a mannosylated antibody-enzyme fusion protein used in experimental cancer therapy.

    PubMed

    Kogelberg, Heide; Tolner, Berend; Sharma, Surinder K; Lowdell, Mark W; Qureshi, Uzma; Robson, Mathew; Hillyer, Tim; Pedley, R Barbara; Vervecken, Wouter; Contreras, Roland; Begent, Richard H J; Chester, Kerry A

    2007-01-01

    MFECP1 is a mannosylated antibody-enzyme fusion protein used in antibody-directed enzyme prodrug therapy (ADEPT). The antibody selectively targets tumor cells and the targeted enzyme converts a prodrug into a toxic drug. MFECP1 is obtained from expression in the yeast Pichia pastoris and produced to clinical grade. The P. pastoris-derived mannosylation of the fusion protein aids rapid normal tissue clearance required for successful ADEPT. The work presented provides evidence that MFECP1 is cleared by the endocytic and phagocytic mannose receptor (MR), which is known to bind to mannose-terminating glycans. MR-transfected fibroblast cells internalize MFECP1 as revealed by flow cytometry and confocal microscopy. Immunofluorescence microscopy shows that in vivo clearance in mice occurs predominantly by MR on liver sinusoidal endothelial cells, although MR is also expressed on adjacent Kupffer cells. In the spleen, MFECP1 is taken up by MR-expressing macrophages residing in the red pulp and not by dendritic cells which are found in the marginal zone and white pulp. Clearance can be inhibited in vivo by the MR inhibitor mannan as shown by increased enzyme activities in blood. The work improves understanding of interactions of MFECP1 with normal tissue, shows that glycosylation can be exploited in the design of recombinant anticancer therapeutics and opens the ways for optimizing pharmacokinetics of mannosylated recombinant therapeutics.

  5. Amplifying the Red-Emission of Upconverting Nanoparticles for Biocompatible Clinically Used Prodrug-Induced Photodynamic Therapy

    DOE PAGES

    Punjabi, Amol; Wu, Xiang; Tokatli-Apollon, Amira; ...

    2014-09-25

    A class of biocompatible upconverting nanoparticles (UCNPs) with largely amplified red-emissions was developed. The optimal UCNP shows a high absolute upconversion quantum yield of 3.2% in red-emission, which is 15-fold stronger than the known optimal β-phase core/shell UCNPs. When conjugated to aminolevulinic acid, a clinically used photodynamic therapy (PDT) prodrug, significant PDT effect in tumor was demonstrated in a deep-tissue (>1.2 cm) setting in vivo at a biocompatible laser power density. Furthermore, we show that our UCNP–PDT system with NIR irradiation outperforms clinically used red light irradiation in a deep tumor setting in vivo. This study marks a major stepmore » forward in photodynamic therapy utilizing UCNPs to effectively access deep-set tumors.Lastly, it also provides an opportunity for the wide application of upconverting red radiation in photonics and biophotonics.« less

  6. Amplifying the red-emission of upconverting nanoparticles for biocompatible clinically used prodrug-induced photodynamic therapy.

    PubMed

    Punjabi, Amol; Wu, Xiang; Tokatli-Apollon, Amira; El-Rifai, Mahmoud; Lee, Hyungseok; Zhang, Yuanwei; Wang, Chao; Liu, Zhuang; Chan, Emory M; Duan, Chunying; Han, Gang

    2014-10-28

    A class of biocompatible upconverting nanoparticles (UCNPs) with largely amplified red-emissions was developed. The optimal UCNP shows a high absolute upconversion quantum yield of 3.2% in red-emission, which is 15-fold stronger than the known optimal β-phase core/shell UCNPs. When conjugated to aminolevulinic acid, a clinically used photodynamic therapy (PDT) prodrug, significant PDT effect in tumor was demonstrated in a deep-tissue (>1.2 cm) setting in vivo at a biocompatible laser power density. Furthermore, we show that our UCNP-PDT system with NIR irradiation outperforms clinically used red light irradiation in a deep tumor setting in vivo. This study marks a major step forward in photodynamic therapy utilizing UCNPs to effectively access deep-set tumors. It also provides an opportunity for the wide application of upconverting red radiation in photonics and biophotonics.

  7. Amplifying the Red-Emission of Upconverting Nanoparticles for Biocompatible Clinically Used Prodrug-Induced Photodynamic Therapy

    SciTech Connect

    Punjabi, Amol; Wu, Xiang; Tokatli-Apollon, Amira

    A class of biocompatible upconverting nanoparticles (UCNPs) with largely amplified red-emissions was developed. The optimal UCNP shows a high absolute upconversion quantum yield of 3.2% in red-emission, which is 15-fold stronger than the known optimal β-phase core/shell UCNPs. When conjugated to aminolevulinic acid, a clinically used photodynamic therapy (PDT) prodrug, significant PDT effect in tumor was demonstrated in a deep-tissue (>1.2 cm) setting in vivo at a biocompatible laser power density. Furthermore, we show that our UCNP–PDT system with NIR irradiation outperforms clinically used red light irradiation in a deep tumor setting in vivo. This study marks a major stepmore » forward in photodynamic therapy utilizing UCNPs to effectively access deep-set tumors.Lastly, it also provides an opportunity for the wide application of upconverting red radiation in photonics and biophotonics.« less

  8. Chinese Medicine Amygdalin and β-Glucosidase Combined with Antibody Enzymatic Prodrug System As A Feasible Antitumor Therapy.

    PubMed

    Li, Yun-Long; Li, Qiao-Xing; Liu, Rui-Jiang; Shen, Xiang-Qian

    2018-03-01

    Amarogentin is an efficacious Chinese herbal medicine and a component of the bitter apricot kernel. It is commonly used as an expectorant and supplementary anti-cancer drug. β-Glucosidase is an enzyme that hydrolyzes the glycosidic bond between aryl and saccharide groups to release glucose. Upon their interaction, β-glucosidase catalyzes amarogentin to produce considerable amounts of hydrocyanic acid, which inhibits cytochrome C oxidase, the terminal enzyme in the mitochondrial respiration chain, and suspends adenosine triphosphate synthesis, resulting in cell death. Hydrocyanic acid is a cell-cycle-stage-nonspecific agent that kills cancer cells. Thus, β-glucosidase can be coupled with a tumor-specific monoclonal antibody. β-Glucosidase can combine with cancer-cell-surface antigens and specifically convert amarogentin to an active drug that acts on cancer cells and the surrounding antibodies to achieve a killing effect. β-Glucosidase is injected intravenously and recognizes cancer-cell-surface antigens with the help of an antibody. The prodrug amarogentin is infused after β-glucosidase has reached the target position. Coupling of cell membrane peptides with β-glucosidase allows the enzyme to penetrate capillary endothelial cells and clear extracellular deep solid tumors to kill the cells therein. The Chinese medicine amarogentin and β-glucosidase will become an important treatment for various tumors when an appropriate monoclonal antibody is developed.

  9. Oral enzyme therapy for celiac sprue

    PubMed Central

    Bethune, Michael T; Khosla, Chaitan

    2012-01-01

    Celiac sprue is an inflammatory disease of the small intestine caused by dietary gluten and treated by adherence to a lifelong gluten-free diet. The recent identification of immunodominant gluten peptides, the discovery of their cogent properties, and the elucidation of the mechanisms by which they engender immunopathology in genetically-susceptible individuals have advanced our understanding of the molecular pathogenesis of this complex disease, enabling the rational design of new therapeutic strategies. The most clinically advanced of these is oral enzyme therapy, in which enzymes capable of proteolyzing gluten (i.e. glutenases) are delivered to the alimentary tract of a celiac sprue patient to detoxify ingested gluten in situ. In this chapter, we discuss the key challenges for discovery and preclinical development of oral enzyme therapies for celiac sprue. Methods for lead identification, assay development, gram-scale production and formulation, and lead optimization for next-generation proteases are described and critically assessed. PMID:22208988

  10. A phase I trial of hypoxoside as an oral prodrug for cancer therapy--absence of toxicity.

    PubMed

    Smit, B J; Albrecht, C F; Liebenberg, R W; Kruger, P B; Freestone, M; Gouws, L; Theron, E; Bouic, P J; Etsebeth, S; van Jaarsveld, P P

    1995-09-01

    To assess the toxicity of hypoxoside taken orally by 24 patients with lung cancer. Open study with patients taking 1,200-3,200 mg standardised Hypoxis plant extract (200 mg capsules) per day divided in 3 doses in order to maintain metabolite blood levels near 100 micrograms/ml. Patients with histologically proven squamous, large-cell or adenocarcinoma were hospitalised initially at the radiation oncology ward, Karl Bremer Hospital, Bellville, W. Cape. Thereafter they returned every 2 weeks for full clinical examinations. Routine biochemical and haematological measurements were done. Patients underwent regular full clinical examinations including radiographs and computed tomography scanning according to the discretion of the principal investigator. Nineteen patients on hypoxoside therapy survived for an average of 4 months with progression of their primary tumours and metastases, while 5 survived for more than a year. One of them survived for 5 years and histological examination of the primary lesion showed absence of cancer. No toxic effects, in clinical examinations or biochemical or haematological measurements, were found that could be ascribed to the ingestion of hypoxoside. Only one occasion of possible drug intolerance, with anxiety, nausea, vomiting and diarrhoea, was noted. The absence of toxicity warrants further investigation of hypoxoside as an oral prodrug, especially in patients with slow-growing necrotising tumours that are inoperable and have high concentrations of beta-glucuronidase and sulphatase as well as a high sensitivity for rooperol.

  11. PET imaging of β-glucuronidase activity by an activity-based 124I-trapping probe for the personalized glucuronide prodrug targeted therapy.

    PubMed

    Su, Yu-Cheng; Cheng, Ta-Chun; Leu, Yu-Ling; Roffler, Steve R; Wang, Jaw-Yuan; Chuang, Chih-Hung; Kao, Chien-Han; Chen, Kai-Chuan; Wang, Hsin-Ell; Cheng, Tian-Lu

    2014-12-01

    Beta-glucuronidase (βG) is a potential biomarker for cancer diagnosis and prodrug therapy. The ability to image βG activity in patients would assist in personalized glucuronide prodrug cancer therapy. However, whole-body imaging of βG activity for medical usage is not yet available. Here, we developed a radioactive βG activity-based trapping probe for positron emission tomography (PET). We generated a (124)I-tyramine-conjugated difluoromethylphenol beta-glucuronide probe (TrapG) to form (124)I-TrapG that could be selectively activated by βG for subsequent attachment of (124)I-tyramine to nucleophilic moieties near βG-expressing sites. We estimated the specificity of a fluorescent FITC-TrapG, the cytotoxicity of tyramine-TrapG, and the serum half-life of (124)I-TrapG. βG targeting of (124)I-TrapG in vivo was examined by micro-PET. The biodistribution of (131)I-TrapG was investigated in different organs. Finally, we imaged the endogenous βG activity and assessed its correlation with therapeutic efficacy of 9-aminocamptothecin glucuronide (9ACG) prodrug in native tumors. FITC-TrapG showed specific trapping at βG-expressing CT26 (CT26/mβG) cells but not in CT26 cells. The native TrapG probe possessed low cytotoxicity. (124)I-TrapG preferentially accumulated in CT26/mβG but not CT26 cells. Meanwhile, micro-PET and whole-body autoradiography results demonstrated that (124)I-TrapG signals in CT26/mβG tumors were 141.4-fold greater than in CT26 tumors. Importantly, Colo205 xenografts in nude mice that express elevated endogenous βG can be monitored by using infrared glucuronide trapping probes (NIR-TrapG) and suppressed by 9ACG prodrug treatment. (124)I-TrapG exhibited low cytotoxicity allowing long-term monitoring of βG activity in vivo to aid in the optimization of prodrug targeted therapy. ©2014 American Association for Cancer Research.

  12. Enzyme replacement therapy of Fabry disease.

    PubMed

    Clarke, Joe T R; Iwanochko, R Mark

    2005-08-01

    Fabry disease is an X-linked lysosomal storage disease caused by deficiency of the enzyme alpha-galactosidase A and results in pain, progressive renal impairment, cardiomyopathy, and cerebrovascular disease. The results of two major randomized, double-blind, placebo-controlled clinical trials and open-label extensions have shown that replacement of the deficient enzyme with either of two preparations of recombinant human alpha-galactosidase A, agalsidase-alfa, and agalsidase-beta is safe. Biweekly i.v. infusions of 0.2 mg/kg of agalsidase-alfa were associated with a significant decrease in pain and stabilization of renal function. Biweekly infusions of 1 mg/kg of agalsidase-beta were associated with virtually complete clearing of accumulated glycolipid substrate from renal and cutaneous capillary endothelial cells. Several smaller, open-label studies, along with observations made in the course of monitoring large numbers of patients on enzyme replacement therapy, indicated that treatment stabilizes renal function and produces significant improvements in myocardial mass and function. Treatment of Fabry disease by enzyme replacement has a significant impact on at least some serious complications of the disease.

  13. Modern prodrug design for targeted oral drug delivery.

    PubMed

    Dahan, Arik; Zimmermann, Ellen M; Ben-Shabat, Shimon

    2014-10-14

    The molecular information that became available over the past two decades significantly influenced the field of drug design and delivery at large, and the prodrug approach in particular. While the traditional prodrug approach was aimed at altering various physiochemical parameters, e.g., lipophilicity and charge state, the modern approach to prodrug design considers molecular/cellular factors, e.g., membrane influx/efflux transporters and cellular protein expression and distribution. This novel targeted-prodrug approach is aimed to exploit carrier-mediated transport for enhanced intestinal permeability, as well as specific enzymes to promote activation of the prodrug and liberation of the free parent drug. The purpose of this article is to provide a concise overview of this modern prodrug approach, with useful successful examples for its utilization. In the past the prodrug approach used to be viewed as a last option strategy, after all other possible solutions were exhausted; nowadays this is no longer the case, and in fact, the prodrug approach should be considered already in the very earliest development stages. Indeed, the prodrug approach becomes more and more popular and successful. A mechanistic prodrug design that aims to allow intestinal permeability by specific transporters, as well as activation by specific enzymes, may greatly improve the prodrug efficiency, and allow for novel oral treatment options.

  14. Iterative design of emetine-based prodrug targeting fibroblast activation protein (FAP) and dipeptidyl peptidase IV DPPIV using a tandem enzymatic activation strategy.

    PubMed

    Akinboye, Emmanuel S; Brennen, W Nathaniel; Rosen, D Marc; Bakare, Oladapo; Denmeade, Samuel R

    2016-06-01

    There is an urgent need to develop new agents for treating metastatic prostate cancer to overcome multiple drug resistance to the current standard targeted cancer therapy. Emetine is a highly cytotoxic natural product protein synthesis inhibitor, which is toxic to all cell types. Its cytotoxicity can be blocked by derivatizing its N-2' position. Thus emetine can be selectively delivered to cancer cells in the region of metastatic cancer as a prodrug that will be activated by an enzyme selectively overexpressed within the metastatic tumor microenvironment. In this work, we convert emetine to a prodrug activatable by the fibroblast activation protein (FAP), a serine protease overexpressed by the carcinoma associated fibroblasts. By using an iterative structure-activity relationship strategy, several peptidyl emetine prodrug analogs (1-11) were synthesized by chemical derivatization of emetine at its N-2' position and tested for in-vitro activation by FAP. The lead prodrug 11 is made up of a DPPIV activatable prodrug precursor 10 (Ala-Pro-PABC-Emetine) coupled to FAP substrate (Ala-Ser-Gly-Pro-Ala-Gly-Pro). Activation assays of the prodrugs were performed in purified FAP, DPPIV, FBS, and human serum and were analyzed by LCMS. In vitro cytotoxicity assays of these prodrugs are carried out in prostate (LNCaP, PC3) and breast (MCF7 and MDA-MB-231) cancer cell lines. The prodrugs are also tested in normal immortalized human prostatic epithelial cell line (PrEC). The lead FAP activated emetine prodrug 11 is activated to emetine in tandem by FAP and DPPIV in about 70% conversion within 24 hr. In prostate and breast cancer cell lines treated with prodrug 11, it is found to be equipotent with emetine in the presence of FAP and DPPIV. However, in the PrEC cell line grown in serum free media, prodrug 11 is more than 200-fold less cytotoxic than emetine in the absence of FAP and DPPIV. This FAP activated prodrug of cytotoxic agent emetine further shows the crucial role of the

  15. GR-891: a novel 5-fluorouracil acyclonucleoside prodrug for differentiation therapy in rhabdomyosarcoma cells

    PubMed Central

    Marchal, J A; Prados, J; Melguizo, C; Gómez, J A; Campos, J; Gallo, M A; Espinosa, A; Arena, N; Aránega, A

    1999-01-01

    Differentiation therapy provides an alternative treatment of cancer that overcomes the undesirable effects of classical chemotherapy, i.e. cytotoxicity and resistance to drugs. This new approach to cancer therapy focuses on the development of specific agents designed to selectively engage the process of terminal differentiation, leading to the elimination of tumorigenic cells and recovery of normal cell homeostasis. A series of new anti-cancer pyrimidine acyclonucleoside-like compounds were designed and synthesized by structural modifications of 5-fluorouracil, a drug which causes considerable cell toxicity and morbidity, and we evaluated their applicability for differentiation therapy in human rhabdomyosarcoma cells. We tested the pyrimidine derivative GR-891, (RS)-1-{[3-(2-hydroxyethoxy)-1-isopropoxy]propyl}-5-fluorouracil, an active drug which shows low toxicity in vivo and releases acrolein which is an aldehyde with anti-tumour activity. Both GR-891 and 5-fluorouracil caused time- and dose-dependent growth inhibition in vitro; however, GR-891 showed no cytotoxicity at low doses (22.5 μmol l−1 and 45 μmol l−1) and induced terminal myogenic differentiation in RD cells (a rhabdomyosarcoma cell line) treated for 6 days. Changes in morphological features and in protein organization indicated re-entry in the pathway of muscular maturation. Moreover, GR-891 increased adhesion capability mediated by the expression of fibronectin, and did not induce overexpression of P-glycoprotein, the mdr1 gene product, implicated in multidrug resistance. New acyclonucleoside-like compounds such as GR-891 have important potential advantages over 5-fluorouracil because of their lower toxicity and their ability to induce myogenic differentiation in rhabdomyosarcoma cells. Our results suggest that this drug may be useful for differentiation therapy in this type of tumour. 1999 Cancer Research Campaign PMID:10070873

  16. An Enzyme-Responsive "Turn-on" Fluorescence Polymeric Superamphiphile as a Potential Visualizable Phosphate Prodrug Delivery Vehicle.

    PubMed

    Yang, Xi; Shen, Shihong; Guo, Li; Tan, Jidong; Lei, Henxin; Wu, Jianghan; Zhao, Lei; Xiong, Tao; Wu, Youshen; Cheng, Yilong; Zhang, Yanfeng

    2018-06-01

    The development of inexpensive and highly efficient enzyme-responsive polymers has significantly contributed to targeted drug delivery systems. Here, a superamphiphile with a capability of fluorescent dissociation sensing is designed. It is constructed with negatively charged adenosine 5'-triphosphate (ATP) and negatively charged fluorescein diphosphate (FDP), which are used as fluorescence detection, and a cationic diblock copolymer methoxy-poly(ethylene glycol) 113 -b-poly(2-dimethyl-aminoethyl methacrylate) 70 . Upon addition of calf intestinal alkaline phosphatase, the superamphiphile disintegrates, presumably due to the enzymatic hydrolysis of ATP. This process is accompanied by an increase in the fluorescence emission intensity of fluorescein owing to the hydrolysis of FDP. The in vitro application of the superamphiphile is also proven. Thus, the "turn-on" fluorescence of the superamphiphile serves as a real-time module for detection of the disintegration of superamphiphile. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Design of pH-sensitive methotrexate prodrug-targeted curcumin nanoparticles for efficient dual-drug delivery and combination cancer therapy.

    PubMed

    Xie, Jiajiang; Fan, Zhongxiong; Li, Yang; Zhang, Yinying; Yu, Fei; Su, Guanghao; Xie, Liya; Hou, Zhenqing

    2018-01-01

    We designed acid-labile methotrexate (MTX) targeting prodrug self-assembling nanoparticles loaded with curcumin (CUR) drug for simultaneous delivery of multi-chemotherapeutic drugs and combination cancer therapy. A dual-acting MTX, acting as both an anticancer drug and as a tumor-targeting ligand, was coupled to 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[aldehyde(polyethylene glycol)-2000] via Schiff's base reaction. The synthesized prodrug conjugate (DSPE-PEG-Imine-MTX) could be self-assembled into micellar nanoparticles (MTX-Imine-M) in aqueous solution, which encapsulated CUR into their core by hydrophobic interactions (MTX-Imine-M-CUR). The prepared MTX-Imine-M-CUR nanoparticles were composed of an inner hydrophobic DSPE/CUR core and an outside hydrophilic bishydroxyl poly (ethyleneglycol) (PEG) shell with a self-targeting MTX prodrug corona. The imine linker between 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[aldehyde(polyethyleneglycol)-2000] and MTX, as a dynamic covalent bond, was strong enough to remain intact in physiological pH, even though it is rapidly cleaved in acidic pH. The MTX-Imine-M-CUR could codeliver MTX and CUR selectively and efficiently into the cancer cells via folate receptor-mediated endocytosis followed by the rapid intracellular release of CUR and the active form of MTX via the acidity of endosomes/lysosomes. Moreover, the MTX-Imine-M-CUR resulted in significantly higher in vitro and in vivo anticancer activity than pH-insensitive DSPE-PEGAmide-MTX assembling nanoparticles loaded with CUR (MTX-Amide-M-CUR), MTX unconjugated DSPE-PEG assembling micellar nanoparticles loaded with CUR (M-CUR), combination of both free drugs, and individual free drugs. The smart system provided a simple, yet feasible, drug delivery strategy for targeted combination chemotherapy.

  18. Enzyme replacement therapy on hypophosphatasia mouse model

    PubMed Central

    Montaño, Adriana M.; Shimada, Tsutomu; Sly, William S.

    2013-01-01

    Hypophosphatasia (HPP) is an inborn error of metabolism caused by deficiency of the tissue-nonspecific alkaline phosphatase (TNSALP), resulting in a defect of bone mineralization. Natural substrates for this ectoenzyme accumulate extracellulary including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5-phosphate (PLP), a co-factor form of vitamin B6. Enzyme replacement therapy (ERT) for HPP by functional TNSALP is one of the therapeutic options. The C-terminal-anchorless human recombinant TNSALP derived from Chinese hamster ovary cell lines was purified. TNSALP-null mice (Akp2−/−), an infantile model of HPP, were treated from birth using TNSALP and vitamin B6 diet. Long-term efficacy studies of ERT consisted of every 3 days subcutaneous or intravenous injections till 28 days old (dose 20 U/g) and subsequently every 3 days intravenous injections for 6 months (dose 10 U/g). We assessed therapeutic effect by growth and survival rates, fertility, skeletal manifestations, and radiographic and pathological finding. Treated Akp2−/− mice grew normally till 4 weeks and appeared well with a minimum skeletal abnormality as well as absence of epilepsy, compared with untreated mice which died by 3 weeks old. The prognosis of TNSALP-treated Akp2−/− mice was improved substantially: 1) prolonged life span over 6 months, 2) improvement of the growth, and 3) normal fertility. After 6 months of treatment, we found moderate hypomineralization with abnormal proliferative chondrocytes in growth plate and articular cartilage. In conclusion, ERT with human native TNSALP improves substantial clinical manifestations in Akp2−/− mice, suggesting that ERT with anchorless TNSALP is also a potential therapy for HPP. PMID:23978959

  19. Catalytic activity of certain antibodies as a potential tool for drug synthesis and for directed prodrug therapies.

    PubMed

    Wójcik, T; Kieć-Kononowicz, K

    2008-01-01

    Catalytic activity of certain antibodies was proposed by Linus Pauling for the very first time more than six decades ago. Since then few examples of catalytic antibodies (abzymes) were found in human organism. From late 80's many synthetic abzymes were obtained after immunization by Transition State Analogs (TSA). Another approach is based on functional mimicry of antibody to an active site of an enzyme. Detection of an abzymatic activity requires special immunoassays. This unique strategy can be employed for new methods of drug synthesis, as well as for in vivo therapies. Catalytic antibodies seem to be a promising tool for therapeutic purposes, because of their specifity and stereoselectivity.

  20. Prodrugs for Improving Tumor Targetability and Efficiency

    PubMed Central

    Mahato, Rubi; Tai, Wanyi; Cheng, Kun

    2011-01-01

    As the mainstay in the treatment of various cancers for several decades, chemotherapy is successful but still faces challenges including non-selectivity and high toxicity. Improving the selectivity is therefore a critical step to improve the therapeutic efficacy of chemotherapy. Prodrug is one of the most promising approaches to increase the selectivity and efficacy of a chemotherapy drug. The classical prodrug approach is to improve the pharmaceutical properties (solubility, stability, permeability, irritation, distribution, etc.) via a simple chemical modification. This review will focus on various targeted prodrug designs that have been developed to increase the selectivity of chemotherapy drugs. Various tumor-targeting ligands, transporter-associated ligands, and polymers can be incorporated in a prodrug to enhance the tumor uptake. Prodrugs can also be activated by enzymes that are specifically expressed at a higher level in tumors, leading to a selective anti-tumor effect. This can be achieved by conjugating the enzyme to a tumor-specific antibody, or delivering a vector expressing the enzyme into tumor cells. PMID:21333700

  1. Towards antibody-drug conjugates and prodrug strategies with extracellular stimuli-responsive drug delivery in the tumor microenvironment for cancer therapy.

    PubMed

    Joubert, Nicolas; Denevault-Sabourin, Caroline; Bryden, Francesca; Viaud-Massuard, Marie-Claude

    2017-12-15

    The design of innovative anticancer chemotherapies with superior antitumor efficacy and reduced toxicity continues to be a challenging endeavor. Recently, the success of Adcetris ® and Kadcyla ® made antibody-drug conjugates (ADCs) serious contenders to reach the envied status of Paul Ehrlich's "magic bullet". However, ADCs classically target overexpressed and internalizing antigens at the surface of cancer cells, and in solid tumors are associated with poor tumor penetration, insufficient targeting in heterogeneous tumors, and appearance of several resistance mechanisms. In this context, alternative non-internalizing ADCs and prodrugs have been developed to circumvent these limitations, in which the drug can be selectively released by an extracellular stimulus in the tumor microenvironment. Each strategy and method of activation will be discussed as potential alternatives to internalizing ADCs for cancer therapy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Enzymes approved for human therapy: indications, mechanisms and adverse effects.

    PubMed

    Baldo, Brian A

    2015-02-01

    Research and drug developments fostered under orphan drug product development programs have greatly assisted the introduction of efficient and safe enzyme-based therapies for a range of rare disorders. The introduction and regulatory approval of 20 different recombinant enzymes has enabled, often for the first time, effective enzyme-replacement therapy for some lysosomal storage disorders, including Gaucher (imiglucerase, taliglucerase, and velaglucerase), Fabry (agalsidase alfa and beta), and Pompe (alglucosidase alfa) diseases and mucopolysaccharidoses I (laronidase), II (idursulfase), IVA (elosulfase), and VI (galsulfase). Approved recombinant enzymes are also now used as therapy for myocardial infarction (alteplase, reteplase, and tenecteplase), cystic fibrosis (dornase alfa), chronic gout (pegloticase), tumor lysis syndrome (rasburicase), leukemia (L-asparaginase), some collagen-based disorders such as Dupuytren's contracture (collagenase), severe combined immunodeficiency disease (pegademase bovine), detoxification of methotrexate (glucarpidase), and vitreomacular adhesion (ocriplasmin). The development of these efficacious and safe enzyme-based therapies has occurred hand in hand with some remarkable advances in the preparation of the often specifically designed recombinant enzymes; the manufacturing expertise necessary for commercial production; our understanding of underlying mechanisms operative in the different diseases; and the mechanisms of action of the relevant recombinant enzymes. Together with information on these mechanisms, safety findings recorded so far on the various adverse events and problems of immunogenicity of the recombinant enzymes used for therapy are presented.

  3. Effects of vehicles and prodrug properties and their interactions on the delivery of 6-mercaptopurine through skin: bisacyloxymethyl-6-mercaptopurine prodrugs.

    PubMed

    Waranis, R P; Sloan, K B

    1987-08-01

    A series of S6,9-bisacyloxymethyl-6-mercaptopurine (6,9-bis-6-MP) prodrug derivatives was synthesized and characterized. The solubilities of the derivatives in solvents (vehicles), which exhibited a wide range of polarities from water to oleic acid, were measured. The abilities of the prodrugs to deliver 6-mercaptopurine (6-MP) from the vehicles have also been determined, and experimental fluxes and permeability coefficients (Kp) have been calculated for a large number of prodrug: vehicle combinations. Generally the best prodrugs of the series in terms of delivering 6-MP, regardless of the vehicle, were the first two members--the bisacetyl- and the bispropionyloxymethyl-6-mercaptopurine prodrugs. This result has been attributed mainly to the increased water solubility of these two prodrugs compared with that of 6-MP and the other prodrugs, since all of the prodrugs are much more lipid soluble than 6-MP. For three vehicles--isopropyl myristate, propylene glycol, and water--there was a good correlation between log experimental Kp for the delivery of 6-MP by the prodrugs from those vehicles and the theoretical solubility parameters of the prodrugs. The stabilities of the bisacetyl-(2), bisproprionyl-(3), and bisbutyryloxymethyl-6-mercaptopurine (4) derivatives were determined in buffer and in buffer containing enzymes leached from the dermis. Prodrug 2 was more stable than 3 or 4 in the buffer containing the enzymes, while 4 was more stable than 2 or 3 in the plain buffer.

  4. Activation of a camptothecin prodrug by specific carboxylesterases as predicted by quantitative structure-activity relationship and molecular docking studies.

    PubMed

    Yoon, Kyoung Jin P; Krull, Erik J; Morton, Christopher L; Bornmann, William G; Lee, Richard E; Potter, Philip M; Danks, Mary K

    2003-11-01

    7-Ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (irinotecan, CPT-11) is a camptothecin prodrug that is metabolized by carboxylesterases (CE) to the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38), a topoisomerase I inhibitor. CPT-11 has shown encouraging antitumor activity against a broad spectrum of tumor types in early clinical trials, but hematopoietic and gastrointestinal toxicity limit its administration. To increase the therapeutic index of CPT-11 and to develop other prodrug analogues for enzyme/prodrug gene therapy applications, our laboratories propose to develop camptothecin prodrugs that will be activated by specific CEs. Specific analogues might then be predicted to be activated, for example, predominantly by human liver CE(hCE1), by human intestinal CE (hiCE), or in gene therapy approaches using a rabbit liver CE (rCE). This study describes a molecular modeling approach to relate the structure of rCE-activated camptothecin prodrugs with their biological activation. Comparative molecular field analysis, comparative molecular similarity index analysis, and docking studies were used to predict the biological activity of a 4-benzylpiperazine derivative of CPT-11 [7-ethyl-10-[4-(1-benzyl)-1-piperazino]carbonyloxycamptothecin (BP-CPT)] in U373MG glioma cell lines transfected with plasmids encoding rCE or hiCE. BP-CPT has been reported to be activated more efficiently than CPT-11 by a rat serum esterase activity; however, three-dimensional quantitative structure-activity relationship studies predicted that rCE would activate BP-CPT less efficiently than CPT-11. This was confirmed by both growth inhibition experiments and kinetic studies. The method is being used to design camptothecin prodrugs predicted to be activated by specific CEs.

  5. Development of a Hypoxic Radiosensitizer-Prodrug Liposome Delivery DNA Repair Inhibitor Dbait Combination with Radiotherapy for Glioma Therapy.

    PubMed

    Liu, Hongmei; Cai, Yifan; Zhang, Yafei; Xie, Yandong; Qiu, Hui; Hua, Lei; Liu, Xuejiao; Li, Yuling; Lu, Jun; Zhang, Longzhen; Yu, Rutong

    2017-06-01

    Gliomas are highly radioresistant tumors, mainly due to hypoxia in the core region of the gliomas and efficient DNA double-strand break repair. However, the design of a radiosensitizer incorporating the two above mechanisms is difficult and has rarely been reported. Thus, this study develops a hypoxic radiosensitizer-prodrug liposome (MLP) to deliver the DNA repair inhibitor Dbait (MLP/Dbait) to achieve the simultaneous entry of radiosensitizers with two different mechanisms into the glioma. MLP/Dbait effectively sensitizes glioma cells to X-ray radiotherapy (RT). Histological and microscopic examinations of dissected brain tissue confirm that MLP effectively delivers Dbait into the glioma. Furthermore, the combination of MLP/Dbait with RT significantly inhibits growth of the glioma, as assessed by in vivo bioluminescence imaging. These findings suggest that MLP is a promising candidate as a Dbait delivery system to enhance the effect of RT on glioma, owing to the synergistic effects of the two different radiosensitizers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Enzyme replacement therapy for murine hypophosphatasia.

    PubMed

    Millán, José Luis; Narisawa, Sonoko; Lemire, Isabelle; Loisel, Thomas P; Boileau, Guy; Leonard, Pierre; Gramatikova, Svetlana; Terkeltaub, Robert; Camacho, Nancy Pleshko; McKee, Marc D; Crine, Philippe; Whyte, Michael P

    2008-06-01

    Hypophosphatasia (HPP) is the inborn error of metabolism that features rickets or osteomalacia caused by loss-of-function mutation(s) within the gene that encodes the tissue-nonspecific isozyme of alkaline phosphatase (TNALP). Consequently, natural substrates for this ectoenzyme accumulate extracellulary including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5'-phosphate (PLP), a co-factor form of vitamin B6. Babies with the infantile form of HPP often die with severe rickets and sometimes hypercalcemia and vitamin B6-dependent seizures. There is no established medical treatment. Human TNALP was bioengineered with the C terminus extended by the Fc region of human IgG for one-step purification and a deca-aspartate sequence (D10) for targeting to mineralizing tissue (sALP-FcD10). TNALP-null mice (Akp2-/-), an excellent model for infantile HPP, were treated from birth using sALP-FcD10. Short-term and long-term efficacy studies consisted of once daily subcutaneous injections of 1, 2, or 8.2 mg/kg sALP-FcD10 for 15, 19, and 15 or 52 days, respectively. We assessed survival and growth rates, circulating levels of sALP-FcD10 activity, calcium, PPi, and pyridoxal, as well as skeletal and dental manifestations using radiography, microCT, and histomorphometry. Akp2-/- mice receiving high-dose sALP-FcD10 grew normally and appeared well without skeletal or dental disease or epilepsy. Plasma calcium, PPi, and pyridoxal concentrations remained in their normal ranges. We found no evidence of significant skeletal or dental disease. Enzyme replacement using a bone-targeted, recombinant form of human TNALP prevents infantile HPP in Akp2-/- mice.

  7. Enzyme Replacement Therapy for Murine Hypophosphatasia*

    PubMed Central

    Millán, José Luis; Narisawa, Sonoko; Lemire, Isabelle; Loisel, Thomas P; Boileau, Guy; Leonard, Pierre; Gramatikova, Svetlana; Terkeltaub, Robert; Camacho, Nancy Pleshko; McKee, Marc D; Crine, Philippe; Whyte, Michael P

    2008-01-01

    Introduction Hypophosphatasia (HPP) is the inborn error of metabolism that features rickets or osteomalacia caused by loss-of-function mutation(s) within the gene that encodes the tissue-nonspecific isozyme of alkaline phosphatase (TNALP). Consequently, natural substrates for this ectoenzyme accumulate extracellulary including inorganic pyrophosphate (PPi), an inhibitor of mineralization, and pyridoxal 5`-phosphate (PLP), a co-factor form of vitamin B6. Babies with the infantile form of HPP often die with severe rickets and sometimes hypercalcemia and vitamin B6-dependent seizures. There is no established medical treatment. Materials and Methods Human TNALP was bioengineered with the C terminus extended by the Fc region of human IgG for one-step purification and a deca-aspartate sequence (D10) for targeting to mineralizing tissue (sALP-FcD10). TNALP-null mice (Akp2−/−), an excellent model for infantile HPP, were treated from birth using sALP-FcD10. Short-term and long-term efficacy studies consisted of once daily subcutaneous injections of 1, 2, or 8.2 mg/kg sALP-FcD10 for 15, 19, and 15 or 52 days, respectively. We assessed survival and growth rates, circulating levels of sALP-FcD10 activity, calcium, PPi, and pyridoxal, as well as skeletal and dental manifestations using radiography, μCT, and histomorphometry. Results Akp2−/− mice receiving high-dose sALP-FcD10 grew normally and appeared well without skeletal or dental disease or epilepsy. Plasma calcium, PPi, and pyridoxal concentrations remained in their normal ranges. We found no evidence of significant skeletal or dental disease. Conclusions Enzyme replacement using a bone-targeted, recombinant form of human TNALP prevents infantile HPP in Akp2−/− mice. PMID:18086009

  8. Enzyme replacement and substrate reduction therapy for Gaucher disease.

    PubMed

    Shemesh, Elad; Deroma, Laura; Bembi, Bruno; Deegan, Patrick; Hollak, Carla; Weinreb, Neal J; Cox, Timothy M

    2015-03-27

    Gaucher disease, a rare disorder, is caused by inherited deficiency of the enzyme glucocerebrosidase. It is unique among the ultra-orphan disorders in that four treatments are currently approved by various regulatory authorities for use in routine clinical practice. Hitherto, because of the relatively few people affected worldwide, many of whom started therapy during a prolonged period when there were essentially no alternatives to imiglucerase, these treatments have not been systematically evaluated in studies such as randomized controlled trials now considered necessary to generate the highest level of clinical evidence. To summarize all available randomized controlled study data on the efficacy and safety of enzyme replacement therapies and substrate reduction therapy for treating Gaucher disease. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register. Additional searches were conducted on ClinicalTrials.gov for any ongoing studies with potential interim results, and through PubMed. We also searched the reference lists of relevant articles and reviews.Date of last search: 07 August 2014. All randomized and quasi-randomized controlled studies (including open-label studies and cross-over studies) assessing enzyme replacement therapy or substrate reduction therapy, or both, in all types of Gaucher disease were included. Two authors independently assessed the risk of bias in the included studies, and extracted relevant data. Of the 488 studies retrieved by the electronic searches, eight met the inclusion criteria and were analysed (300 participants). Response parameters were restricted to haemoglobin concentration, platelet count, spleen and liver volume and serum biomarkers (chitotriosidase and CCL18). Only one publication reported a 'low risk of bias' score in all parameters assessed, and all studies included were randomized.Four studies reported the responses to enzyme replacement therapy of previously

  9. Activation of multiple chemotherapeutic prodrugs by the natural enzymolome of tumour-localised probiotic bacteria.

    PubMed

    Lehouritis, Panos; Stanton, Michael; McCarthy, Florence O; Jeavons, Matthieu; Tangney, Mark

    2016-01-28

    Some chemotherapeutic drugs (prodrugs) require activation by an enzyme for efficacy. We and others have demonstrated the ability of probiotic bacteria to grow specifically within solid tumours following systemic administration, and we hypothesised that the natural enzymatic activity of these tumour-localised bacteria may be suitable for activation of certain such chemotherapeutic drugs. Several wild-type probiotic bacteria; Escherichia coli Nissle, Bifidobacterium breve, Lactococcus lactis and Lactobacillus species, were screened against a panel of popular prodrugs. All strains were capable of activating at least one prodrug. E. coli Nissle 1917 was selected for further studies because of its ability to activate numerous prodrugs and its resistance to prodrug toxicity. HPLC data confirmed biochemical transformation of prodrugs to their toxic counterparts. Further analysis demonstrated that different enzymes can complement prodrug activation, while simultaneous activation of multiple prodrugs (CB1954, 5-FC, AQ4N and Fludarabine phosphate) by E. coli was confirmed, resulting in significant efficacy improvement. Experiments in mice harbouring murine tumours validated in vitro findings, with significant reduction in tumour growth and increase in survival of mice treated with probiotic bacteria and a combination of prodrugs. These findings demonstrate the ability of probiotic bacteria, without the requirement for genetic modification, to enable high-level activation of multiple prodrugs specifically at the site of action. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Metabolic enzymes dysregulation in heart failure: the prospective therapy.

    PubMed

    Parihar, Priyanka; Parihar, Mordhwaj Singh

    2017-01-01

    The heart failure accounts for the highest mortality rate all over the world. The development of preventive therapeutic approaches is still in their infancy. Owing to the extremely high energy demand of the heart, the bioenergetics pathways need to respond efficiently based on substrate availability. The metabolic regulation of such heart bioenergetics is mediated by various rate limiting enzymes involved in energy metabolism. Although all the pertinent mechanisms are not clearly understood, the progressive decline in the activity of metabolic enzymes leading to diminished ATP production is known to cause progression of the heart failure. Therefore, metabolic therapy that can maintain the appropriate activities of metabolic enzymes can be a promising approach for the prevention and treatment of the heart failure. The flavonoids that constitute various human dietary ingredients also effectively offer a variety of health benefits. The flavonoids target a variety of metabolic enzymes and facilitate effective management of the equilibrium between production and utilization of energy in the heart. This review discusses the broad impact of metabolic enzymes in the heart functions and explains how the dysregulated enzyme activity causes the heart failure. In addition, the prospects of targeting dysregulated metabolic enzymes by developing flavonoid-based metabolic approaches are discussed.

  11. Effect of Cromakalim Prodrug 1 (CKLP1) on Aqueous Humor Dynamics and Feasibility of Combination Therapy With Existing Ocular Hypotensive Agents

    PubMed Central

    Roy Chowdhury, Uttio; Rinkoski, Tommy A.; Bahler, Cindy K.; Millar, J. Cameron; Bertrand, Jacques A.; Holman, Bradley H.; Sherwood, Joseph M.; Overby, Darryl R.; Stoltz, Kristen L.; Dosa, Peter I.; Fautsch, Michael P.

    2017-01-01

    Purpose Cromakalim prodrug 1 (CKLP1) is a water-soluble ATP-sensitive potassium channel opener that has shown ocular hypotensive properties in ex vivo and in vivo experimental models. To determine its mechanism of action, we assessed the effect of CKLP1 on aqueous humor dynamics and in combination therapy with existing ocular hypotensive agents. Methods Outflow facility was assessed in C57BL/6 mice by ex vivo eye perfusions and by in vivo constant flow infusion following CKLP1 treatment. Human anterior segments with no trabecular meshwork were evaluated for effect on pressure following CKLP1 treatment. CKLP1 alone and in combination with latanoprost, timolol, and Rho kinase inhibitor Y27632 were evaluated for effect on intraocular pressure in C57BL/6 mice and Dutch-belted pigmented rabbits. Results CKLP1 lowered episcleral venous pressure (control: 8.9 ± 0.1 mm Hg versus treated: 6.2 ± 0.1 mm Hg, P < 0.0001) but had no detectable effect on outflow facility, aqueous humor flow rate, or uveoscleral outflow. Treatment with CKLP1 in human anterior segments without the trabecular meshwork resulted in a 50% ± 9% decrease in pressure, suggesting an effect on the distal portion of the conventional outflow pathway. CKLP1 worked additively with latanoprost, timolol, and Y27632 to lower IOP, presumably owing to combined effects on different aspects of aqueous humor dynamics. Conclusions CKLP1 lowered intraocular pressure by reducing episcleral venous pressure and lowering distal outflow resistance in the conventional outflow pathway. Owing to this unique mechanism of action, CKLP1 works in an additive manner to lower intraocular pressure with latanoprost, timolol, and Rho kinase inhibitor Y27632. PMID:29114841

  12. Acid-activatable prodrug nanogels for efficient intracellular doxorubicin release.

    PubMed

    Zhan, Fuxing; Chen, Wei; Wang, Zhongjuan; Lu, Wentao; Cheng, Ru; Deng, Chao; Meng, Fenghua; Liu, Haiyan; Zhong, Zhiyuan

    2011-10-10

    Endosomal pH-activatable doxorubicin (DOX) prodrug nanogels were designed, prepared, and investigated for triggered intracellular drug release in cancer cells. DOX prodrugs with drug grafting contents of 3.9, 5.7, and 11.7 wt % (denoted as prodrugs 1, 2, and 3, respectively) were conveniently obtained by sequential treatment of poly(ethylene glycol)-b-poly(2-hydroxyethyl methacrylate-co-ethyl glycinate methacrylamide) (PEG-b-P(HEMA-co-EGMA)) copolymers with hydrazine and doxorubicin hydrochloride. Notably, prodrugs 1, 2, and 3 formed monodispersed nanogels with average sizes of 114.4, 75.3, and 66.3 nm, respectively, in phosphate buffer (PB, 10 mM, pH 7.4). The in vitro release results showed that DOX was released rapidly and nearly quantitatively from DOX prodrug nanogels at endosomal pH and 37 °C in 48 h, whereas only a minor amount (ca. 20% or less) of drug was released at pH 7.4 under otherwise the same conditions. Confocal laser scanning microscope (CLSM) observations revealed that DOX prodrug nanogels delivered and released DOX into the cytosols as well as cell nuclei of RAW 264.7 cells following 24 h incubation. MTT assays demonstrated that prodrug 3 had pronounced cytotoxic effects to tumor cells following 72 h incubation with IC(50) data determined to be 2.0 and 3.4 μg DOX equiv/mL for RAW 264.7 and MCF-7 tumor cells, respectively. The corresponding polymer carrier, PEG-b-P(HEMA-co-GMA-hydrazide), was shown to be nontoxic up to a tested concentration of 1.32 mg/mL. These endosomal pH-activatable DOX prodrug nanogels uniquely combining features of water-soluble macromolecular prodrugs and nanogels offer a promising platform for targeted cancer therapy.

  13. Abrogation of Microsatellite-instable Tumors Using a Highly Selective Suicide Gene/Prodrug Combination

    PubMed Central

    Ferrás, Cristina; Oude Vrielink, Joachim AF; Verspuy, Johan WA; te Riele, Hein; Tsaalbi-Shtylik, Anastasia; de Wind, Niels

    2009-01-01

    A substantial fraction of sporadic and inherited colorectal and endometrial cancers in humans is deficient in DNA mismatch repair (MMR). These cancers are characterized by length alterations in ubiquitous simple sequence repeats, a phenotype called microsatellite instability. Here we have exploited this phenotype by developing a novel approach for the highly selective gene therapy of MMR-deficient tumors. To achieve this selectivity, we mutated the VP22FCU1 suicide gene by inserting an out-of-frame microsatellite within its coding region. We show that in a significant fraction of microsatellite-instable (MSI) cells carrying the mutated suicide gene, full-length protein becomes expressed within a few cell doublings, presumably resulting from a reverting frameshift within the inserted microsatellite. Treatment of these cells with the innocuous prodrug 5-fluorocytosine (5-FC) induces strong cytotoxicity and we demonstrate that this owes to multiple bystander effects conferred by the suicide gene/prodrug combination. In a mouse model, MMR-deficient tumors that contained the out-of-frame VP22FCU1 gene displayed strong remission after treatment with 5-FC, without any obvious adverse systemic effects to the mouse. By virtue of its high selectivity and potency, this conditional enzyme/prodrug combination may hold promise for the treatment or prevention of MMR-deficient cancer in humans. PMID:19471249

  14. Pancreatic enzyme replacement therapy for people with cystic fibrosis.

    PubMed

    Somaraju, Usha Rani; Solis-Moya, Arturo

    2014-10-13

    Most people with cystic fibrosis (80% to 90%) need pancreatic enzyme replacement therapy to prevent malnutrition. Enzyme preparations need to be taken whenever food is taken, and the dose needs to be adjusted according to the food consumed. A systematic review on the efficacy and safety of pancreatic enzyme replacement therapy is needed to guide clinical practice, as there is variability between centres with respect to assessment of pancreatic function, time of commencing treatment, dose and choice of supplements. To evaluate the efficacy and safety of pancreatic enzyme replacement therapy in children and adults with cystic fibrosis and to compare the efficacy and safety of different formulations of this therapy and their appropriateness in different age groups. Also, to compare the effects of pancreatic enzyme replacement therapy in cystic fibrosis according to different diagnostic subgroups (e.g. different ages at introduction of therapy and different categories of pancreatic function). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Most recent search: 14 August 2014.We also searched an ongoing trials website and the websites of the pharmaceutical companies who manufacture pancreatic enzyme replacements for any additional trials. Most recent search: 12 May 2014. Randomised and quasi-randomised controlled trials in people of any age, with cystic fibrosis and receiving pancreatic enzyme replacement therapy, at any dosage and in any formulation, for a period of not less than four weeks, compared to placebo or other pancreatic enzyme replacement therapy preparations. Two authors independently assessed trials and extracted outcome data. They also assessed the risk of bias of the trials included in the review. One parallel trial and 11 cross-over trials of children and

  15. Pancreatic enzyme replacement therapy for people with cystic fibrosis.

    PubMed

    Somaraju, Usha Rani; Solis-Moya, Arturo

    2016-11-23

    Most people with cystic fibrosis (80% to 90%) need pancreatic enzyme replacement therapy to prevent malnutrition. Enzyme preparations need to be taken whenever food is taken, and the dose needs to be adjusted according to the food consumed. A systematic review on the efficacy and safety of pancreatic enzyme replacement therapy is needed to guide clinical practice, as there is variability between centres with respect to assessment of pancreatic function, time of commencing treatment, dose and choice of supplements. This is an updated version of a published review. To evaluate the efficacy and safety of pancreatic enzyme replacement therapy in children and adults with cystic fibrosis and to compare the efficacy and safety of different formulations of this therapy and their appropriateness in different age groups. Also, to compare the effects of pancreatic enzyme replacement therapy in cystic fibrosis according to different diagnostic subgroups (e.g. different ages at introduction of therapy and different categories of pancreatic function). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Most recent search: 15 July 2016.We also searched an ongoing trials website and the websites of the pharmaceutical companies who manufacture pancreatic enzyme replacements for any additional trials. Most recent search: 22 July 2016. Randomised and quasi-randomised controlled trials in people of any age, with cystic fibrosis and receiving pancreatic enzyme replacement therapy, at any dosage and in any formulation, for a period of not less than four weeks, compared to placebo or other pancreatic enzyme replacement therapy preparations. Two authors independently assessed trials and extracted outcome data. They also assessed the risk of bias of the trials included in the review. One

  16. [The switch of enzyme therapy in Fabry disease].

    PubMed

    Riccio, Eleonora; Pisani, Antonio

    2014-01-01

    Fabry disease (FD) is a multiorgan X-linked lysosomal storage disorder resulted from the deficiency of the lysosomal enzyme alpha galactosidase A. It particularly affects the heart, kidneys and cerebrovascular system. The treatment options for FD patients include long-term enzyme replacement therapy (ERT). Two recombinant enzyme formulations for the ERT of FD are available on European market: agalsidase alfa and agalsidase beta. Numerous evidences in the literature have confirmed the safety and efficacy of ERT. However, to date, there have been limited comparisons between the two agents, and no firm conclusion can be drawn regarding their specific efficacy and safety. In June 2009, a viral contamination in the manufacturing process of Fabrazyme led to a global shortage of agalsidase beta. Recommendations to shift patients to the recommended dose of Replagal were published by the European Medicines Agency (EMA) for all patients receiving Fabrazyme. This offered the unique opportunity to compare, although indirectly, the two drugs evaluating any clinical modification or adverse events that occurred after the switch. Moreover, with the increased availability of agalsidase beta in the last 3 months of 2012, some of the patients who previously switched to agalsidase alfa, were switched-back and returned to full-dose agalsidase beta. This article reviews the published evidence for the clinical efficacy of the two available enzyme preparations and compare it with the experience of our center.

  17. New Enzyme Prodrug and Methionine-Depletion Combination Therapy of Breast Cancer Designed for Effective Delivery to the Tumor

    DTIC Science & Technology

    2012-10-01

    arabinofuranosyl-2-fluoroadenine 5’-phosphate in mice and dogs , Cancer Treat. Rep. 67 (1983) 445-456. 9. X. Huang, M. Bennett, P.E. Thorpe, A...infections, and gastrointestinal tox ici t ies such as stromatitis, nausea, vomiting, and diarrhea [3 ]. To * Corresponding author. Address: School

  18. Theranostic Imaging of Cancer Gene Therapy.

    PubMed

    Sekar, Thillai V; Paulmurugan, Ramasamy

    2016-01-01

    Gene-directed enzyme prodrug therapy (GDEPT) is a promising therapeutic approach for treating cancers of various phenotypes. This strategy is independent of various other chemotherapeutic drugs used for treating cancers where the drugs are mainly designed to target endogenous cellular mechanisms, which are different in various cancer subtypes. In GDEPT an external enzyme, which is different from the cellular proteins, is expressed to convert the injected prodrug in to a toxic metabolite, that normally kill cancer cells express this protein. Theranostic imaging is an approach used to directly monitor the expression of these gene therapy enzymes while evaluating therapeutic effect. We recently developed a dual-GDEPT system where we combined mutant human herpes simplex thymidine kinase (HSV1sr39TK) and E. coli nitroreductase (NTR) enzyme, to improve therapeutic efficiency of cancer gene therapy by simultaneously injecting two prodrugs at a lower dose. In this approach we use two different prodrugs such as ganciclovir (GCV) and CB1954 to target two different cellular mechanisms to kill cancer cells. The developed dual GDEPT system was highly efficacious than that of either of the system used independently. In this chapter, we describe the complete protocol involved for in vitro and in vivo imaging of therapeutic cancer gene therapy evaluation.

  19. Highly phosphomannosylated enzyme replacement therapy for GM2 gangliosidosis.

    PubMed

    Tsuji, Daisuke; Akeboshi, Hiromi; Matsuoka, Kazuhiko; Yasuoka, Hiroko; Miyasaki, Eri; Kasahara, Yoshiko; Kawashima, Ikuo; Chiba, Yasunori; Jigami, Yoshifumi; Taki, Takao; Sakuraba, Hitoshi; Itoh, Kohji

    2011-04-01

    Novel recombinant human lysosomal β-hexosaminidase A (HexA) was developed for enzyme replacement therapy (ERT) for Tay-Sachs and Sandhoff diseases, ie, autosomal recessive GM2 gangliosidoses, caused by HexA deficiency. A recombinant human HexA (Om4HexA) with a high mannose 6-phosphate (M6P)-type-N-glycan content, which was produced by a methylotrophic yeast strain, Ogataea minuta, overexpressing the OmMNN4 gene, was intracerebroventricularly (ICV) administered to Sandhoff disease model mice (Hexb⁻/⁻ mice) at different doses (0.5-2.5 mg/kg), and then the replacement and therapeutic effects were examined. The Om4HexA was widely distributed across the ependymal cell layer, dose-dependently restored the enzyme activity due to uptake via cell surface cation-independent M6P receptor (CI-M6PR) on neural cells, and reduced substrates, including GM2 ganglioside (GM2), asialo GM2 (GA2), and oligosaccharides with terminal N-acetylglucosamine residues (GlcNAc-oligosaccharides), accumulated in brain parenchyma. A significant inhibition of chemokine macrophage inflammatory protein-1 α (MIP-1α) induction was also revealed, especially in the hindbrain (< 63%). The decrease in central neural storage correlated with an improvement of motor dysfunction as well as prolongation of the lifespan. This lysosome-directed recombinant human enzyme drug derived from methylotrophic yeast has the high therapeutic potential to improve the motor dysfunction and quality of life of the lysosomal storage diseases (LSDs) patients with neurological manifestations. We emphasize the importance of neural cell surface M6P receptor as a delivery target of neural cell-directed enzyme replacement therapy (NCDERT) for neurodegenerative metabolic diseases. Copyright © 2010 American Neurological Association.

  20. Enzyme replacement therapy in alpha-mannosidosis guinea-pigs.

    PubMed

    Crawley, Allison C; King, Barbara; Berg, Thomas; Meikle, Peter J; Hopwood, John J

    2006-01-01

    alpha-Mannosidosis is a lysosomal storage disorder caused by deficient activity of lysosomal alpha-mannosidase and is characterised by massive accumulation of mannose-containing oligosaccharides in affected individuals. Patients develop behaviour and learning difficulties, skeletal abnormalities, immune deficiency and hearing impairment. Disease in alpha-mannosidosis guinea-pigs resembles the clinical, histopathological, biochemical and molecular features of the human disease. We have used the guinea-pig model to investigate efficacy of enzyme replacement therapy as a treatment for alpha-mannosidosis. Intravenous recombinant human lysosomal alpha-mannosidase, administered at a dose of 1mg/kg, was cleared from circulation with a half-life of 53 h, with significant enzyme activity (1.4x normal levels) detected in circulation one week post-injection. alpha-Mannosidase administered to alpha-mannosidosis guinea-pigs at 1mg/kg (onset at birth or approximately 30 days) and 10mg/kg (at birth) was distributed widely amongst tissues, including to capillary depleted brain. By monitoring with tandem mass spectrometry, enzyme replacement therapy was found to be effective in reducing stored substrates in peripheral tissues at both dose rates, and in brain by up to 39% at the 10mg/kg dose, compared with untreated alpha-mannosidosis controls. Reductions of up to 60% of urinary mannose containing oligosaccharides were also observed. No histological improvements were seen in the brain at either dose, however marked decreases in lysosomal vacuolation in liver, kidney, spleen and endocrine pancreas, as well as a significant reduction in trigeminal ganglion neurons were observed. Multiple injections of 1mg/kg recombinant enzyme in alpha-mannosidosis guinea-pigs induced a very rapid humoral immune response precluding long-term intravenous treatment.

  1. Expression of β-glucuronidase on the surface of bacteria enhances activation of glucuronide prodrugs.

    PubMed

    Cheng, C-M; Chen, F M; Lu, Y-L; Tzou, S-C; Wang, J-Y; Kao, C-H; Liao, K-W; Cheng, T-C; Chuang, C-H; Chen, B-M; Roffler, S; Cheng, T-L

    2013-05-01

    Extracellular activation of hydrophilic glucuronide prodrugs by β-glucuronidase (βG) was examined to increase the therapeutic efficacy of bacteria-directed enzyme prodrug therapy (BDEPT). βG was expressed on the surface of Escherichia coli by fusion to either the bacterial autotransporter protein Adhesin (membrane βG (mβG)/AIDA) or the lipoprotein (lpp) outermembrane protein A (mβG/lpp). Both mβG/AIDA and mβG/lpp were expressed on the bacterial surface, but only mβG/AIDA displayed enzymatic activity. The rate of substrate hydrolysis by mβG/AIDA-BL21cells was 2.6-fold greater than by pβG-BL21 cells, which express periplasmic βG. Human colon cancer HCT116 cells that were incubated with mβG/AIDA-BL21 bacteria were sensitive to a glucuronide prodrug (p-hydroxy aniline mustard β-D-glucuronide, HAMG) with an half maximal inhibitory concentration (IC50) value of 226.53±45.4 μM, similar to the IC50 value of the active drug (p-hydroxy aniline mustard, pHAM; 70.6±6.75 μM), indicating that mβG/AIDA on BL21 bacteria could rapidly and efficiently convert HAMG to an active anticancer agent. These results suggest that surface display of functional βG on bacteria can enhance the hydrolysis of glucuronide prodrugs and may increase the effectiveness of BDEPT.

  2. Prodrug Strategies for Paclitaxel.

    PubMed

    Meng, Ziyuan; Lv, Quanxia; Lu, Jun; Yao, Houzong; Lv, Xiaoqing; Jiang, Feng; Lu, Aiping; Zhang, Ge

    2016-05-23

    Paclitaxel is an anti-tumor agent with remarkable anti-tumor activity and wide clinical uses. However, it is also faced with various challenges especially for its poor water solubility and low selectivity for the target. To overcome these disadvantages of paclitaxel, approaches using small molecule modifications and macromolecule modifications have been developed by many research groups from all over the world. In this review, we discuss the different strategies especially prodrug strategies that are currently used to make paclitaxel more effective.

  3. Enzyme replacement therapy in Fabry disease: influence on cardiac manifestations.

    PubMed

    Caballero, L; Climent, V; Hernández-Romero, D; Quintanilla, M A; de la Morena, G; Marín, F

    2010-01-01

    Fabry disease (FD) is an X-linked glycosphingolipid storage disorder caused by deficient activity of the lysosomal enzyme alpha-galactosidase A. This leads to a progressive accumulation of globotriaosylceramide (Gb3) in the lysosomes of different cells and tissues, causing principally ventricular hypertrophy, renal failure and cerebrovascular accidents, reducing lifespan both in hemizygous males and heterozygous females. Residual enzyme activity might lead to slow progression of the disease and result in the so-called cardiac or renal variants with delayed presentation. Two different forms of alpha-galactosidase A enzyme replacement therapies (ERT) are available for the treatment of FD, one genetically engineered in human cell line (agalsidase alfa, Replagal, Shire) and the other produced in a Chinese hamster ovary cell line (agalsidase beta, Fabrazyme, Genzyme). Although both proteins are structurally and functionally very similar, with the same amino acid sequence as the native human enzyme, they differ in the pattern of glycosilation of the protein depending on the originating cell line. Studies with both preparations have described a reduction in plasma, urinary sediment and tissue levels of Gb3, a decrease in the frequency of pain crisis and a reduction in left ventricular mass and improvement or stabilization of renal function. Studies have generally shown the greatest benefit when treatment is started at an early stage of the disease before extensive fibrosis or other irreversible tissue damage takes place. However, more data are needed to document long-term treatment outcomes. The aim of the present review is to provide an update overview of the two different forms of ERT for FD, their clinical effects in cardiac manifestations and their possible differences in terms of efficacy, side effects and safety profiles.

  4. Enzyme replacement therapy for Anderson-Fabry disease.

    PubMed

    El Dib, Regina; Gomaa, Huda; Carvalho, Raíssa Pierri; Camargo, Samira E; Bazan, Rodrigo; Barretti, Pasqual; Barreto, Fellype C

    2016-07-25

    Anderson-Fabry disease is an X-linked defect of glycosphingolipid metabolism. Progressive renal insufficiency is a major source of morbidity, additional complications result from cardio- and cerebro-vascular involvement. Survival is reduced among affected males and symptomatic female carriers.This is an update of a Cochrane review first published in 2010, and previously updated in 2013. To evaluate the effectiveness and safety of enzyme replacement therapy compared to other interventions, placebo or no interventions, for treating Anderson-Fabry disease. We searched the Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register (date of the most recent search: 08 July 2016). We also searched 'Clinical Trials' on The Cochrane Library, MEDLINE, Embase and LILACS (date of the most recent search: 24 September 2015). Randomized controlled trials of agalsidase alfa or beta in participants diagnosed with Anderson-Fabry disease. Two authors selected relevant trials, assessed methodological quality and extracted data. Nine trials comparing either agalsidase alfa or beta in 351 participants fulfilled the selection criteria.Both trials comparing agalsidase alfa to placebo reported on globotriaosylceramide concentration in plasma and tissue; aggregate results were non-significant. One trial reported pain scores measured by the Brief Pain Inventory severity, there was a statistically significant improvement for participants receiving treatment at up to three months, mean difference -2.10 (95% confidence interval -3.79 to -0.41; at up to five months, mean difference -1.90 (95% confidence interval -3.65 to -0.15); and at up to six months, mean difference -2.00 (95% confidence interval -3.66 to -0.34). There was a significant difference in the Brief Pain Inventory pain-related quality of life at over five months and up to six months, mean difference -2.10 (95% confidence interval -3.92 to -0.28) but not at other time points. Death was not an outcome

  5. Integrating a novel SN38 prodrug into the PEGylated liposomal system as a robust platform for efficient cancer therapy in solid tumors.

    PubMed

    Fang, Tao; Dong, Yuehan; Zhang, Xiaomin; Xie, Ke; Lin, Li; Wang, Hangxiang

    2016-10-15

    Liposomal nanoassemblies have been used extensively as carriers for the delivery of both lipophilic and hydrophilic drugs. They represent a mature, versatile technology with considerable potential for improving the pharmacokinetics of drugs. However, the formulation of many chemotherapeutics into liposome systems has posed a significant challenge due to their incompatible physicochemical properties, as was the case with camptothecin-based chemotherapeutics. Here, we present a rational paradigm of potent chemotherapeutics that were reconstructed and subsequently integrated into liposomal nanoassemblies. Using SN38 (7-ethyl-10-hydroxy camptothecin) as a model drug, a lipophilic prodrug 1 (designated as LA-SN38) was constructed by tethering the linoleic acid (LA) moiety via esterification, which was further facilitated to form liposomal nanoparticles (LipoNP) through supramolecular nanoassembly. The resulting 1-loaded LipoNP exhibited sustained drug release kinetics and decreased cellular uptake by macrophage cells. Uptake by tumor cells was enhanced relative to our previous supramolecular nanoparticles (SNP 1), which were derived from the self-assembling prodrug 1. Notably, LipoNP outperformed SNP 1 in terms of pharmacokinetics and in vivo therapeutic efficacy in both human BEL-7402 hepatocellular carcinoma (HCC) and HCT-116 colorectal cancer-derived xenograft mouse models. These results were likely due to the improved systemic circulation and preferential accumulation of nanodrugs in tumors. Hence, our results suggest that the combination of liposomal delivery platforms with rational prodrug engineering may emerge as a promising approach for the effective and safe delivery of anticancer chemotherapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Engineering of GlcNAc-1-Phosphotransferase for Production of Highly Phosphorylated Lysosomal Enzymes for Enzyme Replacement Therapy.

    PubMed

    Liu, Lin; Lee, Wang-Sik; Doray, Balraj; Kornfeld, Stuart

    2017-06-16

    Several lysosomal enzymes currently used for enzyme replacement therapy in patients with lysosomal storage diseases contain very low levels of mannose 6-phosphate, limiting their uptake via mannose 6-phosphate receptors on the surface of the deficient cells. These enzymes are produced at high levels by mammalian cells and depend on endogenous GlcNAc-1-phosphotransferase α/β precursor to phosphorylate the mannose residues on their glycan chains. We show that co-expression of an engineered truncated GlcNAc-1-phosphotransferase α/β precursor and the lysosomal enzyme of interest in the producing cells resulted in markedly increased phosphorylation and cellular uptake of the secreted lysosomal enzyme. This method also results in the production of highly phosphorylated acid β-glucocerebrosidase, a lysosomal enzyme that normally has just trace amounts of this modification.

  7. Fabry disease in children: agalsidase-beta enzyme replacement therapy.

    PubMed

    Borgwardt, L; Feldt-Rasmussen, U; Rasmussen, A K; Ballegaard, M; Meldgaard Lund, A

    2013-05-01

    Fabry disease is a rare, multiorgan disease. The most serious complications involve the kidney, brain and heart. This study aims to assess the effect of enzyme replacement therapy (ERT) using agalsidase-beta in children with Fabry disease. We carried out a nationwide, descriptive and observational retrospective cohort study of 10 children (9-16 years at baseline), who underwent regular systematic investigations for 1-8 years after initiation of ERT with agalsidase-beta (Fabryzyme®, Genzyme). Ophthalmological, echocardiographic abnormalities and hypohidrosis were found at baseline and during the follow-up period. Serious kidney, heart or brain involvement had not developed at the last follow-up examination. For the majority of the patients improvements were found concerning headache, acroparaesthesias and gastrointestinal pain during the follow-up period. The level of energy and physical activity also increased. Treatment with agalsidase-beta was associated with a reduction of neuropathic and abdominal pain and headache. Although all aspects of the Fabry pain phenotype cannot be treated with ERT, the observed effects were clinically significant in the lives of the majority of Fabry children and together with the absence of serious Fabry manifestations at last follow-up, we argue that early initiation of ERT may be considered. © 2012 John Wiley & Sons A/S.

  8. Enzyme replacement therapy and fatigue in adults with Pompe disease.

    PubMed

    Güngör, Deniz; de Vries, Juna M; Brusse, Esther; Kruijshaar, Michelle E; Hop, Wim C J; Murawska, Magda; van den Berg, Linda E M; Reuser, Arnold J J; van Doorn, Pieter A; Hagemans, Marloes L C; Plug, Iris; van der Ploeg, Ans T

    2013-06-01

    Pompe disease is a hereditary metabolic myopathy, for which enzyme replacement therapy (ERT) has been available since 2006. We investigated whether ERT reduces fatigue in adult patients with Pompe disease. In this prospective international observational survey, we used the Fatigue Severity Scale (FSS) to measure fatigue. Repeated measures ANOVA was used to analyze the data over time. In a subgroup of patients, we also evaluated muscle strength using the Medical Research Council Scale, measured pulmonary function as Forced Vital Capacity, and assessed depression using the Hospital Anxiety and Depression Scale. We followed 163 patients for a median period of 4 years before ERT and for 3 years during ERT. Before ERT, the mean FSS score remained stable at around 5.3 score points; during ERT, scores improved significantly by 0.13 score points per year (p < 0.001). Fatigue decreased mainly in women, in older patients and in those with shorter disease duration. Patients' improvements in fatigue were moderately correlated with the effect of ERT on depression (r 0.55; CI 95% 0.07 to 0.70) but not with the effect of ERT on muscle strength or pulmonary function. Fatigue is a common and disabling problem in patients with early and advanced stages of Pompe disease. Our finding that ERT helps to reduce fatigue is therefore important for this patient population, irrespective of the mechanisms underlying this effect. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Enzyme

    MedlinePlus

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  10. Development of macromolecular prodrug for rheumatoid arthritis☆

    PubMed Central

    Yuan, Fang; Quan, Ling-dong; Cui, Liao; Goldring, Steven R.; Wang, Dong

    2012-01-01

    Rheumatoid arthritis (RA) is a chronic autoimmune disease that is considered to be one of the major public health problems worldwide. The development of therapies that target tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and co-stimulatory pathways that regulate the immune system have revolutionized the care of patients with RA. Despite these advances, many patients continue to experience symptomatic and functional impairment. To address this issue, more recent therapies that have been developed are designed to target intracellular signaling pathways involved in immunoregulation. Though this approach has been encouraging, there have been major challenges with respect to off-target organ side effects and systemic toxicities related to the widespread distribution of these signaling pathways in multiple cell types and tissues. These limitations have led to an increasing interest in the development of strategies for the macromolecularization of anti-rheumatic drugs, which could target them to the inflamed joints. This approach enhances the efficacy of the therapeutic agent with respect to synovial inflammation, while markedly reducing non-target organ adverse side effects. In this manuscript, we provide a comprehensive overview of the rational design and optimization of macromolecular prodrugs for treatment of RA. The superior and the sustained efficacy of the prodrug may be partially attributed to their Extravasation through Leaky Vasculature and subsequent Inflammatory cell-mediated Sequestration (ELVIS) in the arthritic joints. This biologic process provides a plausible mechanism, by which macromolecular prodrugs preferentially target arthritic joints and illustrates the potential benefits of applying this therapeutic strategy to the treatment of other inflammatory diseases. PMID:22433784

  11. Combination of active targeting, enzyme-triggered release and fluorescent dye into gold nanoclusters for endomicroscopy-guided photothermal/photodynamic therapy to pancreatic ductal adenocarcinoma.

    PubMed

    Li, Hui; Wang, Ping; Deng, Yunxiang; Zeng, Meiying; Tang, Yan; Zhu, Wei-Hong; Cheng, Yingsheng

    2017-09-01

    Pancreatic ductal adenocarcinoma (PDAC) is one of the most devastating malignancies in patients, and there is an urgent need for an effective treatment method. Herein, we report a novel gold nanocluster-based platform for confocal laser endomicroscopy-guided photothermal therapy (PTT)/photodynamic therapy (PDT) for PDAC, which consists of four components: the PTT-carrier gold nanocluster, an active targeting ligand U11 peptide, a Cathepsin E (CTSE)-sensitive PDT therapy prodrug, and a CTSE-sensitive imaging agent (cyanine dye Cy5.5). Due to the strong coupling among cross-linked gold nanoparticles (AuNPs), the surface plasmon resonance peak of nanoclusters shifts to the near-infrared (NIR) region, thus making the nanoclusters useful in the effective PTT therapy. In the system, the labeling of nanoclusters with U11 peptide can distinctly increase their affinity and accelerate their uptake by pancreatic cancer cells. Cell apoptosis staining demonstrates that, upon incorporation of the uPAR-targeted unit, the antitumor efficacy of CTSE-sensitive nanocluster AuS-U11 is significantly enhanced with respect to that of the non-targeted nanocluster AuS-PEG and the insensitive nanocluster AuC-PEG. In vivo and ex vivo optical imaging confirms the high accumulation of AuS-U11 in the in situ pancreatic tumor model. Therapeutic studies further show that the combination of active targeting for tumor tissue, enzyme-triggered drug release of 5-ALA and fluorescent dye Cy5.5 in nanoclusters AuS-U11 could achieve optimal therapeutic efficacy with endomicroscopy-guided photothermal/photodynamic therapy with minimal side effects. As a consequence, the delicate gold nanocluster concept provides a promising strategy to enhance the therapy efficiency in the most challenging PDAC treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Prodrug strategy for cancer cell-specific targeting: A recent overview.

    PubMed

    Zhang, Xian; Li, Xiang; You, Qidong; Zhang, Xiaojin

    2017-10-20

    The increasing development of targeted cancer therapy provides extensive possibilities in clinical trials, and numerous strategies have been explored. The prodrug is one of the most promising strategies in targeted cancer therapy to improve the selectivity and efficacy of cytotoxic compounds. Compared with normal tissues, cancer cells are characterized by unique aberrant markers, thus inactive prodrugs targeting these markers are excellent therapeutics to release active drugs, killing cancer cells without damaging normal tissues. In this review, we explore an integrated view of potential prodrugs applied in targeted cancer therapy based on aberrant cancer specific markers and some examples are provided for inspiring new ideas of prodrug strategy for cancer cell-specific targeting. Copyright © 2017. Published by Elsevier Masson SAS.

  13. Pancreatic enzyme replacement therapy for pancreatic exocrine insufficiency in the 21(st) century.

    PubMed

    Trang, Tony; Chan, Johanna; Graham, David Y

    2014-09-07

    Restitution of normal fat absorption in exocrine pancreatic insufficiency remains an elusive goal. Although many patients achieve satisfactory clinical results with enzyme therapy, few experience normalization of fat absorption, and many, if not most, will require individualized therapy. Increasing the quantity of lipase administered rarely eliminates steatorrhea but increases the cost of therapy. Enteric coated enzyme microbead formulations tend to separate from nutrients in the stomach precluding coordinated emptying of enzymes and nutrients. Unprotected enzymes mix well and empty with nutrients but are inactivated at pH 4 or below. We describe approaches for improving the results of enzyme therapy including changing to, or adding, a different product, adding non-enteric coated enzymes, (e.g., giving unprotected enzymes at the start of the meal and acid-protected formulations later), use of antisecretory drugs and/or antacids, and changing the timing of enzyme administration. Because considerable lipid is emptied in the first postprandial hour, it is prudent to start therapy with enteric coated microbead prior to the meal so that some enzymes are available during that first hour. Patients with hyperacidity may benefit from adjuvant antisecretory therapy to reduce the duodenal acid load and possibly also sodium bicarbonate to prevent duodenal acidity. Comparative studies of clinical effectiveness of different formulations as well as the characteristics of dispersion, emptying, and dissolution of enteric-coated microspheres of different diameter and density are needed; many such studies have been completed but not yet made public. We discuss the history of pancreatic enzyme therapy and describe current use of modern preparations, approaches to overcoming unsatisfactory clinical responses, as well as studies needed to be able to provide reliably effective therapy.

  14. Pancreatic enzyme replacement therapy for pancreatic exocrine insufficiency in the 21st century

    PubMed Central

    Trang, Tony; Chan, Johanna; Graham, David Y

    2014-01-01

    Restitution of normal fat absorption in exocrine pancreatic insufficiency remains an elusive goal. Although many patients achieve satisfactory clinical results with enzyme therapy, few experience normalization of fat absorption, and many, if not most, will require individualized therapy. Increasing the quantity of lipase administered rarely eliminates steatorrhea but increases the cost of therapy. Enteric coated enzyme microbead formulations tend to separate from nutrients in the stomach precluding coordinated emptying of enzymes and nutrients. Unprotected enzymes mix well and empty with nutrients but are inactivated at pH 4 or below. We describe approaches for improving the results of enzyme therapy including changing to, or adding, a different product, adding non-enteric coated enzymes, (e.g., giving unprotected enzymes at the start of the meal and acid-protected formulations later), use of antisecretory drugs and/or antacids, and changing the timing of enzyme administration. Because considerable lipid is emptied in the first postprandial hour, it is prudent to start therapy with enteric coated microbead prior to the meal so that some enzymes are available during that first hour. Patients with hyperacidity may benefit from adjuvant antisecretory therapy to reduce the duodenal acid load and possibly also sodium bicarbonate to prevent duodenal acidity. Comparative studies of clinical effectiveness of different formulations as well as the characteristics of dispersion, emptying, and dissolution of enteric-coated microspheres of different diameter and density are needed; many such studies have been completed but not yet made public. We discuss the history of pancreatic enzyme therapy and describe current use of modern preparations, approaches to overcoming unsatisfactory clinical responses, as well as studies needed to be able to provide reliably effective therapy. PMID:25206255

  15. Preclinical studies of dendrimer prodrugs.

    PubMed

    Kojima, Chie

    2015-01-01

    Dendrimers are synthetic macromolecules with well-defined structures bearing a wide variety of functional groups on their periphery. These groups can be used to conjugate bioactive molecules such as drugs, ligands and imaging agents. Dendrimer prodrugs can be used to improve the water solubility and pharmacokinetic properties of the corresponding free drugs. This article summarizes preclinical studies pertaining to the use of drug-dendrimer conjugates as dendrimer prodrugs for the treatments of various diseases, including cancer and inflammatory diseases. A wide range of anticancer drugs have been conjugated to dendrimers via biodegradable linkers. The side effects of the parent drugs can be markedly reduced using dendrimer prodrugs, with some drugs showing improved efficacy. Anti-inflammatory agents have also been conjugated to dendrimers and used to treat a number of inflammatory diseases. Drug-dendrimer conjugates are preferable to drug-dendrimer complexes, where the use of degradable linkers is critical to the release of the drug. Polyethylene glycol and/or ligands can be added to a dendrimer prodrug, which is useful for the targeting of affected tissues. Imaging probes can also be incorporated into dendrimer prodrugs for the simultaneous delivery of therapeutic and diagnostic agents as 'theranostics.'

  16. Impact of enzyme replacement therapy on cardiac morphology and function and late enhancement in Fabry's cardiomyopathy.

    PubMed

    Beer, Meinrad; Weidemann, Frank; Breunig, Frank; Knoll, Anita; Koeppe, Sabrina; Machann, Wolfram; Hahn, Dietbert; Wanner, Christoph; Strotmann, Jörg; Sandstede, Jörn

    2006-05-15

    The present study evaluated the evolution of cardiac morphology, function, and late enhancement as a noninvasive marker of myocardial fibrosis, and their inter-relation during enzyme replacement therapy in patients with Fabry's disease using magnetic resonance imaging and color Doppler myocardial imaging. Late enhancement, which was present in up to 50% of patients, was associated with increased left ventricular mass, the failure of a significant regression of hypertrophy during enzyme replacement therapy, and worse segmental myocardial function. Late enhancement may predict the effect of enzyme replacement therapy on left ventricular mass and cardiac function.

  17. Cost-effectiveness of enzyme replacement therapy for Fabry disease.

    PubMed

    Rombach, Saskia M; Hollak, Carla E M; Linthorst, Gabor E; Dijkgraaf, Marcel G W

    2013-02-19

    The cost-effectiveness of enzyme replacement therapy (ERT) compared to standard medical care was evaluated in the Dutch cohort of patients with Fabry disease. Cost-effectiveness analysis was performed using a life-time state-transition model. Transition probabilities, effectiveness data and costs were derived from retrospective data and prospective follow-up of the Dutch study cohort consisting of males and females aged 5-78 years. Intervention with ERT (either agalsidase alfa or agalsidase beta) was compared to the standard medical care. The main outcome measures were years without end organ damage (renal, cardiac en cerebrovascular complications), quality adjusted life years (QALYs), and costs. Over a 70 year lifetime, an untreated Fabry patient will generate 55.0 years free of end-organ damage (53.5 years in males, 56.9 years in females) and 48.6 QALYs (47.8 in males, 49.7 in females). Starting ERT in a symptomatic patient increases the number of years free of end-organ damage by 1.5 year (1.6 in males, 1.3 in females), while the number of QALYs gained increases by a similar amount (1.7 in males, 1.4 in females). The costs of ERT starting in the symptomatic stage are between €9 - €10 million (£ 7.9 - £ 8.8 million, $13.0- $14.5 million) during a patient's lifetime. Consequently, the extra costs per additional year free of end-organ damage and the extra costs per additional QALY range from €5.5 - €7.5 million (£ 4.8 - £ 6.6 million, $ 8.0 - $ 10.8 million), undiscounted. In symptomatic patients with Fabry disease, ERT has limited effect on quality of life and progression to end organ damage. The pharmaco-economic evaluation shows that this modest effectiveness drives the costs per QALY and the costs per year free of end-organ damage to millions of euros. Differentiation of patients who may benefit from ERT should be improved to enhance cost-effectiveness.

  18. Troxacitabine prodrugs for pancreatic cancer.

    PubMed

    Adema, A D; Radi, M; Daft, J; Narayanasamy, J; Hoebe, E K; Alexander, L E; Chu, C K; Peters, G J

    2007-01-01

    Troxacitabine is a cytotoxic deoxycytidine analogue with an unnatural L-configuration, which is activated by deoxycytidine kinase (dCK). The configuration is responsible for differences in the uptake and metabolism of troxacitabine compared to other deoxynucleoside analogues. The main drawback in the use of most nucleoside anticancer agents originates from their hydrophilic nature, which property requires a high and frequent dosage for an intravenous administration. To overcome this problem several troxacitabine prodrugs modified in the aminogroup with a linear aliphatic chain with a higher lipophilicity were developed. To determine whether these prodrugs have an advantage over Troxacitabine pancreatic cancer cell lines were exposed to Troxacitabine and the lipophilic prodrugs. The addition of linear aliphatic chains to troxacitabine increased sensitivity of pancreatic cancer cell lines to the drug > 100-fold, possibly due to a better uptake and retention of the drug.

  19. PAM-OBG: A monoamine oxidase B specific prodrug that inhibits MGMT and generates DNA interstrand crosslinks, potentiating temozolomide and chemoradiation therapy in intracranial glioblastoma

    PubMed Central

    Sharpe, Martyn A.; Raghavan, Sudhir; Baskin, David S.

    2018-01-01

    Via extensive analyses of genetic databases, we have characterized the DNA-repair capacity of glioblastoma with respect to patient survival. In addition to elevation of O6-methylguanine DNA methyltransferase (MGMT), down-regulation of three DNA repair pathways; canonical mismatch repair (MMR), Non-Homologous End-Joining (NHEJ), and Homologous Recombination (HR) are correlated with poor patient outcome. We have designed and tested both in vitro and in vivo, a monoamine oxidase B (MAOB) specific prodrug, PAM-OBG, that is converted by glioma MAOB into the MGMT inhibitor O6-benzylguanine (O6BG) and the DNA crosslinking agent acrolein. In cultured glioma cells, we show that PAM-OBG is converted to O6BG, inhibiting MGMT and sensitizing cells to DNA alkylating agents such as BCNU, CCNU, and Temozolomide (TMZ). In addition, we demonstrate that the acrolein generated is highly toxic in glioma treated with an inhibitor of Nucleotide Excision Repair (NER). In mouse intracranial models of primary human glioma, we show that PAM-OBG increases survival of mice treated with either BCNU or CCNU by a factor of six and that in a chemoradiation model utilizing six rounds of TMZ/2Gy radiation, pre-treatment with PAM-OBG more than doubled survival time. PMID:29844863

  20. PAM-OBG: A monoamine oxidase B specific prodrug that inhibits MGMT and generates DNA interstrand crosslinks, potentiating temozolomide and chemoradiation therapy in intracranial glioblastoma.

    PubMed

    Sharpe, Martyn A; Raghavan, Sudhir; Baskin, David S

    2018-05-08

    Via extensive analyses of genetic databases, we have characterized the DNA-repair capacity of glioblastoma with respect to patient survival. In addition to elevation of O 6 -methylguanine DNA methyltransferase (MGMT), down-regulation of three DNA repair pathways; canonical mismatch repair (MMR), Non-Homologous End-Joining (NHEJ), and Homologous Recombination (HR) are correlated with poor patient outcome. We have designed and tested both in vitro and in vivo , a monoamine oxidase B (MAOB) specific prodrug, PAM-OBG, that is converted by glioma MAOB into the MGMT inhibitor O 6 -benzylguanine (O 6 BG) and the DNA crosslinking agent acrolein. In cultured glioma cells, we show that PAM-OBG is converted to O 6 BG, inhibiting MGMT and sensitizing cells to DNA alkylating agents such as BCNU, CCNU, and Temozolomide (TMZ). In addition, we demonstrate that the acrolein generated is highly toxic in glioma treated with an inhibitor of Nucleotide Excision Repair (NER). In mouse intracranial models of primary human glioma, we show that PAM-OBG increases survival of mice treated with either BCNU or CCNU by a factor of six and that in a chemoradiation model utilizing six rounds of TMZ/2Gy radiation, pre-treatment with PAM-OBG more than doubled survival time.

  1. ¹¹¹In-DOTA-Annexin V for imaging of apoptosis during HSV1-tk/GCV prodrug activation gene therapy in mice with NG4TL4 sarcoma.

    PubMed

    Lin, Ming-Hsien; Wu, Shih-Yen; Wang, Hsin-Ell; Liu, Ren-Shyan; Chen, Jyh-Cheng

    2016-02-01

    Apoptosis has been suggested as a cytocidal mechanism of the HSV1-tk-expressing cells when exposed to ganciclovir (GCV). This study evaluated the efficacy of (111)In-labeled Annexin V for monitoring tumor responses during prodrug activation gene therapy with HSV1-tk and GCV. Annexin V was conjugated to DOTA using N-hydroxysulfosuccinimide (sulfo-NHS) and 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC), labeled with (111)In-InCl3 and purified using size exclusion chromatography to give (111)In-DOTA-Annexin V conjugate. The radiochemical yield and the radiochemical purity of (111)In-DOTA-Annexin V were 74±12% and 98±3%, respectively (n=10). (111)In-DOTA-BSA was prepared similarly. An in vitro study to demonstrate the apoptosis of NG4TL4-STK cells after GCV treatment has been performed. Mice bearing NG4TL4-STK and NG4TL4-WT tumors were treated with GCV (10 mg/kg daily) by i.p. injection for 7 consecutive days. Before and during the GCV treatment, biodistribution studies and scintigraphic imaging were performed at 2h post injection of the radiotracers. The uptake of (111)In-DOTA-Annexin V in treated cells (13.41±1.30%) was 4.1 times higher than that in untreated cells (3.21±0.37%). The GCV-induced cell apoptosis in NG4TL4-STK tumor resulted in a significantly increasing accumulation of (111)In-DOTA-Annexin V (1.92±0.32%ID/g at day 0, 4.79±0.86%ID/g at day 2, 4.56±0.58%ID/g at day 4) was observed, but not for that of (111)In-DOTA-BSA. During consecutive GCV treatment, scintigraphic imaging with (111)In-DOTA-Annexin V revealed high uptake in NG4TL4-STK tumor compared with that in NG4TL4-WT tumor. However, no specific (111)In-DOTA-BSA accumulation in NG4TL4-STK and NG4TL4-WT tumors was observed throughout the course of GCV treatment. This study demonstrated that (111)In-DOTA-Annexin V can be used for monitoring tumor cell apoptosis during prodrug activation gene therapy with HSV1-tk and GCV for cancer treatment. Copyright © 2015 Elsevier Ltd. All rights

  2. A biochemical and physicochemical comparison of two recombinant enzymes used for enzyme replacement therapies of hunter syndrome.

    PubMed

    Chung, Yo Kyung; Sohn, Young Bae; Sohn, Jong Mun; Lee, Jieun; Chang, Mi Sun; Kwun, Younghee; Kim, Chi Hwa; Lee, Jin Young; Yook, Yeon Joo; Ko, Ah-Ra; Jin, Dong-Kyu

    2014-05-01

    Mucopolysaccharidosis II (MPS II, Hunter syndrome; OMIM 309900) is an X-linked lysosomal storage disease caused by a deficiency in the enzyme iduronate-2-sulfatase (IDS), leading to accumulation of glycosaminoglycans (GAGs). For enzyme replacement therapy (ERT) of Hunter syndrome, two recombinant enzymes, idursulfase (Elaprase(®), Shire Human Genetic Therapies, Lexington, MA) and idursulfase beta (Hunterase(®), Green Cross Corporation, Yongin, Korea), are currently available in Korea. To compare the biochemical and physicochemical differences between idursulfase and idursulfase beta, we examined the formylglycine (FGly) content, specific enzyme activity, mannose-6-phosphate (M6P) content, sialic acid content, and in vitro cell uptake activity of normal human fibroblasts of these two enzymes.The FGly content, which determines the enzyme activity, of idursulfase beta was significantly higher than that of idursulfase (79.4 ± 0.9 vs. 68.1 ± 2.2 %, P < 0.001). In accordance with the FGly content, the specific enzyme activity of idursulfase beta was significantly higher than that of idursulfase (42.6 ± 1.1 vs. 27.8 ± 0.9 nmol/min/μg protein, P < 0.001). The levels of M6P and sialic acid were not significantly different (2.4 ± 0.1 vs 2.4 ± 0.3 mol/mol protein for M6P and 12.3 ± 0.7 vs. 12.4 ± 0.4 mol/mol protein for sialic acid). However, the cellular uptake activity of the normal human fibroblasts in vitro showed a significant difference (Kuptake, 5.09 ± 0.96 vs. 6.50 ± 1.28 nM protein, P = 0.017).In conclusion, idursulfase beta exhibited significantly higher specific enzyme activity than idursulfase, resulting from higher FGly content. These biochemical differences may be partly attributed to clinical efficacy. However, long-term clinical evaluations of Hunter syndrome patients treated with these two enzymes will be needed to demonstrate the clinical implications of significant difference of the enzyme activity and the FGly content.

  3. Targeted prodrugs in oral drug delivery: the modern molecular biopharmaceutical approach.

    PubMed

    Dahan, Arik; Khamis, Mustafa; Agbaria, Riad; Karaman, Rafik

    2012-08-01

    The molecular revolution greatly impacted the field of drug design and delivery in general, and the utilization of the prodrug approach in particular. The increasing understanding of membrane transporters has promoted a novel 'targeted-prodrug' approach utilizing carrier-mediated transport to increase intestinal permeability, as well as specific enzymes to promote activation to the parent drug. This article provides the reader with a concise overview of this modern approach to prodrug design. Targeting the oligopeptide transporter PEPT1 for absorption and the serine hydrolase valacyclovirase for activation will be presented as examples for the successful utilization of this approach. Additionally, the use of computational approaches, such as DFT and ab initio molecular orbital methods, in modern prodrugs design will be discussed. Overall, in the coming years, more and more information will undoubtedly become available regarding intestinal transporters and potential enzymes that may be exploited for the targeted modern prodrug approach. Hence, the concept of prodrug design can no longer be viewed as merely a chemical modification to solve problems associated with parent compounds. Rather, it opens promising opportunities for precise and efficient drug delivery, as well as enhancement of treatment options and therapeutic efficacy.

  4. Dual-therapy with αvβ3-targeted Sn2 lipase-labile fumagillin-prodrug nanoparticles and zoledronic acid in the Vx2 rabbit tumor model.

    PubMed

    Esser, Alison K; Schmieder, Anne H; Ross, Michael H; Xiang, Jingyu; Su, Xinming; Cui, Grace; Zhang, Huiying; Yang, Xiaoxia; Allen, John S; Williams, Todd; Wickline, Samuel A; Pan, Dipanjan; Lanza, Gregory M; Weilbaecher, Katherine N

    2016-01-01

    Fumagillin, an unstable anti-angiogenesis mycotoxin, was synthesized into a stable lipase-labile prodrug and incorporated into integrin-targeted lipid-encapsulated nanoparticles (αvβ3-Fum-PD NP). Dual anti-angiogenic therapy combining αvβ3-Fum-PD NP with zoledronic acid (ZA), a long-acting osteoclast inhibitor with proposed anti-angiogenic effects, was evaluated. In vitro, αvβ3-Fum-PD NP reduced (P<0.05) endothelial cell viability without impacting macrophage viability. ZA suppressed (P<0.05) macrophage viability at high dosages but not endothelial cell proliferation. 3D MR neovascular imaging of rabbit Vx2 tumors showed no effect with ZA, whereas αvβ3-Fum-PD NP alone and with ZA decreased angiogenesis (P<0.05). Immunohistochemistry revealed decreased (P<0.05) microvascularity with αvβ3-Fum-PD NP and ZA and further microvascular reduction (P<0.05) with dual-therapy. In vivo, ZA did not decrease tumor macrophage numbers nor cancer cell proliferation, whereas αvβ3-Fum-PD-NPs reduced both measures. Dual-therapy with ZA and αvβ3-Fum-PD-NP may provide enhanced neo-adjuvant utility if macrophage ZA uptake is increased. From the Clinical Editor: Although anti-angiogenesis is one of the treatment modalities in the fight against cancer, many cancers become resistant to VEGF pathway inhibitors. In this article, the authors investigated the use of dual therapy using fumagillin, integrin-targeted lipid-encapsulated nanoparticles (αvβ3- Fum-PD NP) and zoledronic acid (ZA), in both in-vitro and in-vivo experiments. This combination approach may provide an insight to the design of future drugs against cancers. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. TH-302, a hypoxia-activated prodrug with broad in vivo preclinical combination therapy efficacy: optimization of dosing regimens and schedules.

    PubMed

    Liu, Qian; Sun, Jessica D; Wang, Jingli; Ahluwalia, Dharmendra; Baker, Amanda F; Cranmer, Lee D; Ferraro, Damien; Wang, Yan; Duan, Jian-Xin; Ammons, W Steve; Curd, John G; Matteucci, Mark D; Hart, Charles P

    2012-06-01

    Subregional hypoxia is a common feature of tumors and is recognized as a limiting factor for the success of radiotherapy and chemotherapy. TH-302, a hypoxia-activated prodrug selectively targeting hypoxic regions of solid tumors, delivers a cytotoxic warhead to the tumor, while maintaining relatively low systemic toxicity. The antitumor activity, different dosing sequences, and dosing regimens of TH-302 in combination with commonly used conventional chemotherapeutics were investigated in human tumor xenograft models. Seven chemotherapeutic drugs (docetaxel, cisplatin, pemetrexed, irinotecan, doxorubicin, gemcitabine, and temozolomide) were tested in combination with TH-302 in eleven human xenograft models, including non-small cell lung cancer (NSCLC), colon cancer, prostate cancer, fibrosarcoma, melanoma, and pancreatic cancer. The antitumor activity of docetaxel, cisplatin, pemetrexed, irinotecan, doxorubicin, gemcitabine, and temozolomide was increased when combined with TH-302 in nine out of eleven models tested. Administration of TH-302 2-8 h prior to the other chemotherapeutics yielded superior efficacy versus other sequences tested. Simultaneous administration of TH-302 and chemotherapeutics increased toxicity versus schedules with dosing separations. In a dosing optimization study, TH-302 administered daily at 50 mg/kg intraperitoneally for 5 days per week in the H460 NSCLC model showed the optimal response with minimal toxicity. TH-302 enhances the activity of a wide range of conventional anti-neoplastic agents in a broad panel of in vivo xenograft models. These data highlight in vivo effects of schedule and order of drug administration in regimen efficacy and toxicity and have relevance to the design of human regimens incorporating TH-302.

  6. TH-302, a hypoxia-activated prodrug with broad in vivo preclinical combination therapy efficacy: optimization of dosing regimens and schedules

    PubMed Central

    Liu, Qian; Sun, Jessica D.; Wang, Jingli; Ahluwalia, Dharmendra; Baker, Amanda F.; Cranmer, Lee D.; Ferraro, Damien; Wang, Yan; Duan, Jian-Xin; Ammons, W. Steve; Curd, John G.; Matteucci, Mark D.

    2014-01-01

    Purpose Subregional hypoxia is a common feature of tumors and is recognized as a limiting factor for the success of radiotherapy and chemotherapy. TH-302, a hypoxia-activated prodrug selectively targeting hypoxic regions of solid tumors, delivers a cytotoxic warhead to the tumor, while maintaining relatively low systemic toxicity. The antitumor activity, different dosing sequences, and dosing regimens of TH-302 in combination with commonly used conventional chemotherapeutics were investigated in human tumor xenograft models. Methods Seven chemotherapeutic drugs (docetaxel, cisplatin, pemetrexed, irinotecan, doxorubicin, gemcitabine, and temozolomide) were tested in combination with TH-302 in eleven human xenograft models, including non-small cell lung cancer (NSCLC), colon cancer, prostate cancer, fibrosarcoma, melanoma, and pancreatic cancer. Results The antitumor activity of docetaxel, cisplatin, pemetrexed, irinotecan, doxorubicin, gemcitabine, and temozolomide was increased when combined with TH-302 in nine out of eleven models tested. Administration of TH-302 2–8 h prior to the other chemotherapeutics yielded superior efficacy versus other sequences tested. Simultaneous administration of TH-302 and chemotherapeutics increased toxicity versus schedules with dosing separations. In a dosing optimization study, TH-302 administered daily at 50 mg/kg intraperitoneally for 5 days per week in the H460 NSCLC model showed the optimal response with minimal toxicity. Conclusions TH-302 enhances the activity of a wide range of conventional anti-neoplastic agents in a broad panel of in vivo xenograft models. These data highlight in vivo effects of schedule and order of drug administration in regimen efficacy and toxicity and have relevance to the design of human regimens incorporating TH-302. PMID:22382881

  7. Modulating lipophilicity of rohitukine via prodrug approach: Preparation, characterization, and in vitro enzymatic hydrolysis in biorelevant media.

    PubMed

    Kumar, Vikas; Bharate, Sonali S; Vishwakarma, Ram A

    2016-09-20

    Rohitukine is a medicinally important natural product which has inspired the discovery of two anticancer clinical candidates. Rohitukine is highly hydrophilic in nature which hampers its oral bioavailability. Thus, herein our objective was to improve the drug-like properties of rohitukine via prodrug-strategy. Various ester prodrugs were synthesized and studied for solubility, lipophilicity, chemical stability and enzymatic hydrolysis in plasma/esterase. All prodrugs displayed lower aqueous solubility and improved lipophilicity compared with rohitukine, which was in accordance with the criteria of compounds in drug-discovery. The stability of synthesized prodrugs was evaluated in buffers at different pH, SGF, SIF, rat plasma and in esterase enzyme. The rate of hydrolysis in all incubation media was dependent primarily on the acyl promoieties. Hexanoyl ester prodrug of rohitukine, 3d, was stable under chemical conditions; however it was completely hydrolyzed to rohitukine, in plasma and in esterase in 4h. Hexanoate ester 3d appeared to be the most promising prodrug as it remained intact at gastric/intestinal pH and was completely transformed to the parent compound in plasma as desired for an ideal prodrug. The data presented herein, will help in designing prodrugs with desired physicochemical properties in future in structurally similar chemotypes. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Safety and efficacy of enzyme replacement therapy in the nephropathy of Fabry disease

    PubMed Central

    Fervenza, Fernando C; Torra, Roser; Warnock, David G

    2008-01-01

    Kidney involvement with progressive loss of kidney function (Fabry nephropathy) is an important complication of Fabry disease, an X-linked lysosomal storage disorder arising from deficiency of α-galactosidase activity. Clinical trials have shown that enzyme replacement therapy (ERT) with recombinant human α-galactosidase clears globotriaosylceramide from kidney cells, and can stabilize kidney function in patients with mild to moderate Fabry nephropathy. Recent trials show that patients with more advanced Fabry nephropathy and overt proteinuria do not respond as well to ERT alone, but can benefit from anti-proteinuric therapy given in conjunction with ERT. This review focuses on the use of enzyme replacement therapy with agalsidase-alfa and agalsidase-beta in adults with Fabry nephropathy. The current results are reviewed and evaluated. The issues of dosing of enzyme replacement therapy, the use of adjunctive agents to control urinary protein excretion, and the individual factors that affect disease severity are reviewed. PMID:19707461

  9. Trial watch – inhibiting PARP enzymes for anticancer therapy

    PubMed Central

    Sistigu, Antonella; Manic, Gwenola; Obrist, Florine; Vitale, Ilio

    2016-01-01

    ABSTRACT Poly(ADP-ribose) polymerases (PARPs) are a members of family of enzymes that catalyze poly(ADP-ribosyl)ation (PARylation) and/or mono(ADP-ribosyl)ation (MARylation), two post-translational protein modifications involved in crucial cellular processes including (but not limited to) the DNA damage response (DDR). PARP1, the most abundant family member, is a nuclear protein that is activated upon sensing distinct types of DNA damage and contributes to their resolution by PARylating multiple DDR players. Recent evidence suggests that, along with DDR, activated PARP1 mediates a series of prosurvival and proapoptotic processes aimed at preserving genomic stability. Despite this potential oncosuppressive role, upregulation and/or overactivation of PARP1 or other PARP enzymes has been reported in a variety of human neoplasms. Over the last few decades, several pharmacologic inhibitors of PARP1 and PARP2 have been assessed in preclinical and clinical studies showing potent antineoplastic activity, particularly against homologous recombination (HR)-deficient ovarian and breast cancers. In this Trial Watch, we describe the impact of PARP enzymes and PARylation in cancer, discuss the mechanism of cancer cell killing by PARP1 inactivation, and summarize the results of recent clinical studies aimed at evaluating the safety and therapeutic profile of PARP inhibitors in cancer patients. PMID:27308587

  10. Prodrugs of phosphonates and phosphates: crossing the membrane barrier

    PubMed Central

    Wiemer, Andrew J.; Wiemer, David F.

    2016-01-01

    A substantial portion of metabolism involves transformation of phosphate esters, including pathways leading to nucleotides and oligonucleotides, carbohydrates, isoprenoids and steroids, and phosphorylated proteins. Because the natural substrates bear one or more negative charges, drugs that target these enzymes generally must be charged as well but small charged molecules can have difficulty traversing the cell membrane other than by endocytosis. The resulting dichotomy has stimulated abundant effort to develop effective prodrugs, compounds that carry little or no charge to enable them to transit biological membranes but then able to release the parent drug once inside the target cell. This chapter will present recent studies on advances in prodrug forms, along with representative examples of their application to marketed and developmental drugs. PMID:25391982

  11. Sulforaphane Preconditioning Sensitizes Human Colon Cancer Cells towards the Bioreductive Anticancer Prodrug PR-104A.

    PubMed

    Erzinger, Melanie M; Bovet, Cédric; Hecht, Katrin M; Senger, Sabine; Winiker, Pascale; Sobotzki, Nadine; Cristea, Simona; Beerenwinkel, Niko; Shay, Jerry W; Marra, Giancarlo; Wollscheid, Bernd; Sturla, Shana J

    2016-01-01

    The chemoprotective properties of sulforaphane (SF), derived from cruciferous vegetables, are widely acknowledged to arise from its potent induction of xenobiotic-metabolizing and antioxidant enzymes. However, much less is known about the impact of SF on the efficacy of cancer therapy through the modulation of drug-metabolizing enzymes. To identify proteins modulated by a low concentration of SF, we treated HT29 colon cancer cells with 2.5 μM SF. Protein abundance changes were detected by stable isotope labeling of amino acids in cell culture. Among 18 proteins found to be significantly up-regulated, aldo-keto reductase 1C3 (AKR1C3), bioactivating the DNA cross-linking prodrug PR-104A, was further characterized. Preconditioning HT29 cells with SF reduced the EC50 of PR-104A 3.6-fold. The increase in PR-104A cytotoxicity was linked to AKR1C3 abundance and activity, both induced by SF in a dose-dependent manner. This effect was reproducible in a second colon cancer cell line, SW620, but not in other colon cancer cell lines where AKR1C3 abundance and activity were absent or barely detectable and could not be induced by SF. Interestingly, SF had no significant influence on PR-104A cytotoxicity in non-cancerous, immortalized human colonic epithelial cell lines expressing either low or high levels of AKR1C3. In conclusion, the enhanced response of PR-104A after preconditioning with SF was apparent only in cancer cells provided that AKR1C3 is expressed, while its expression in non-cancerous cells did not elicit such a response. Therefore, a subset of cancers may be susceptible to combined food-derived component and prodrug treatments with no harm to normal tissues.

  12. Production and purification of the multifunctional enzyme horseradish peroxidase

    PubMed Central

    Spadiut, Oliver; Herwig, Christoph

    2014-01-01

    The oxidoreductase horseradish peroxidase (HRP) is used in numerous industrial and medical applications. In this review, we briefly describe this well-studied enzyme and focus on its promising use in targeted cancer treatment. In combination with a plant hormone, HRP can be used in specific enzyme–prodrug therapies. Despite this outstanding application, HRP has not found its way as a biopharmaceutical into targeted cancer therapy yet. The reasons therefore lie in the present low-yield production and cumbersome purification of this enzyme from its natural source. However, surface glycosylation renders the recombinant production of HRP difficult. Here, we compare different production hosts for HRP and summarize currently used production and purification strategies for this enzyme. We further present our own strategy of glycoengineering this powerful enzyme to allow recombinant high-yield production in Pichia pastoris and subsequent simple downstream processing. PMID:24683473

  13. Cognitive Development in Infantile-Onset Pompe Disease Under Very Early Enzyme Replacement Therapy.

    PubMed

    Lai, Chih-Jou; Hsu, Ting-Rong; Yang, Chia-Feng; Chen, Shyi-Jou; Chuang, Ya-Chin; Niu, Dau-Ming

    2016-12-01

    Most patients with infantile-onset Pompe disease die in early infancy before beginning enzyme replacement therapy, which has made it difficult to evaluate the impact of Pompe disease on cognitive development. Patients with infantile-onset Pompe disease can survive with enzyme replacement therapy, and physicians can evaluate cognitive development in these patients. We established an effective newborn screening program with quick clinical diagnostic criteria. Cognitive and motor development were evaluated using the Bayley Scales of Infant and Toddler Development-Third Edition at 6, 12, and 24 months of age. The patients who were treated very early demonstrate normal cognitive development with no significant change in cognition during this period (P = .18 > .05). The cognitive development was positively correlated with motor development (r = 0.533, P = .011). The results indicated that very early enzyme replacement therapy could protect cognitive development in patients with infantile-onset Pompe disease up to 24 months of age. © The Author(s) 2016.

  14. Pancreatic Proteolytic Enzyme Therapy Compared With Gemcitabine-Based Chemotherapy for the Treatment of Pancreatic Cancer

    PubMed Central

    Chabot, John A.; Tsai, Wei-Yann; Fine, Robert L.; Chen, Chunxia; Kumah, Carolyn K.; Antman, Karen A.; Grann, Victor R.

    2010-01-01

    Purpose Conventional medicine has had little to offer patients with inoperable pancreatic adenocarcinoma; thus, many patients seek alternative treatments. The National Cancer Institute, in 1998, sponsored a randomized, phase III, controlled trial of proteolytic enzyme therapy versus chemotherapy. Because most eligible patients refused random assignment, the trial was changed in 2001 to a controlled, observational study. Methods All patients were seen by one of the investigators at Columbia University, and patients who received enzyme therapy were seen by the participating alternative practitioner. Of 55 patients who had inoperable pancreatic cancer, 23 elected gemcitabine-based chemotherapy, and 32 elected enzyme treatment, which included pancreatic enzymes, nutritional supplements, detoxification, and an organic diet. Primary and secondary outcomes were overall survival and quality of life, respectively. Results At enrollment, the treatment groups had no statistically significant differences in patient characteristics, pathology, quality of life, or clinically meaningful laboratory values. Kaplan-Meier analysis found a 9.7-month difference in median survival between the chemotherapy group (median survival, 14 months) and enzyme treatment groups (median survival, 4.3 months) and found an adjusted-mortality hazard ratio of the enzyme group compared with the chemotherapy group of 6.96 (P < .001). At 1 year, 56% of chemotherapy-group patients were alive, and 16% of enzyme-therapy patients were alive. The quality of life ratings were better in the chemotherapy group than in the enzyme-treated group (P < .01). Conclusion Among patients who have pancreatic cancer, those who chose gemcitabine-based chemotherapy survived more than three times as long (14.0 v 4.3 months) and had better quality of life than those who chose proteolytic enzyme treatment. PMID:19687327

  15. Human β-glucuronidase: structure, function, and application in enzyme replacement therapy.

    PubMed

    Naz, Huma; Islam, Asimul; Waheed, Abdul; Sly, William S; Ahmad, Faizan; Hassan, Imtaiyaz

    2013-10-01

    Lysosomal storage diseases occur due to incomplete metabolic degradation of macromolecules by various hydrolytic enzymes in the lysosome. Despite structural differences, most of the lysosomal enzymes share many common features including a lysosomal targeting motif and phosphotransferase recognition sites. β-Glucuronidase (GUSB) is an important lysosomal enzyme involved in the degradation of glucuronate-containing glycosaminoglycan. The deficiency of GUSB causes mucopolysaccharidosis type VII (MPSVII), leading to lysosomal storage in the brain. GUSB is a well-studied protein for its expression, sequence, structure, and function. The purpose of this review is to summarize our current understanding of sequence, structure, function, and evolution of GUSB and its lysosomal enzyme targeting. Enzyme replacement therapy reported for this protein is also discussed.

  16. Resolution of Hydronephrosis in a Patient With Mucopolysaccharidosis Type II With Enzyme Replacement Therapy.

    PubMed

    Nishiyama, Kei; Imai, Takashi; Ohkubo, Kazuhiro; Sanefuji, Masafumi; Takada, Hidetoshi

    2017-03-01

    Mucopolysaccharidosis type II (MPS II) is caused by deficiency of lysosomal enzyme iduronate-2-sulfatase. Insufficient activity of the enzyme results in accumulation of glycosaminoglycans leading to progressive multisystem pathologies. MPS II is less likely to be complicated by kidney and urinary tract problems. We report a boy with MPS II, who developed left hydronephrosis. His hydronephrosis improved after starting enzyme replacement therapy. It was suggested that MPS II was closely associated with the pathogenesis of hydronephrosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Application of homology modeling to generate CYP1A1 mutants with enhanced activation of the cancer chemotherapeutic prodrug dacarbazine.

    PubMed

    Lewis, Benjamin C; Mackenzie, Peter I; Miners, John O

    2011-11-01

    The chemotherapeutic prodrug dacarbazine (DTIC) has limited efficacy in human malignancies and exhibits numerous adverse effects that arise from systemic exposure to the cytotoxic metabolite. DTIC is activated by CYP1A1 and CYP1A2 catalyzed N-demethylation. However, structural features of these enzymes that confer DTIC N-demethylation have not been characterized. A validated homology model of CYP1A1 was employed to elucidate structure-activity relationships and to engineer CYP1A1 enzymes with altered DTIC activation. In silico docking demonstrated that DTIC orientates proximally to Ser122, Phe123, Asp313, Ala317, Ile386, Tyr259, and Leu496 of human CYP1A1. The site of metabolism is positioned 5.6 Å from the heme iron at an angle of 105.3°. Binding in the active site is stabilized by H-bonding between Tyr259 and the N(2) position of the imidazole ring. Twenty-seven CYP1A1 mutants were generated and expressed in Escherichia coli in yields ranging from 9 to 225 pmol P450/mg. DTIC N-demethylation by the E161K, E256K, and I458V mutants exhibited Michaelis-Menten kinetics, with decreases in K(m) (183-249 μM) that doubled the catalytic efficiency (p < 0.05) relative to wild-type CYP1A1 (K(m), 408 ± 43 μM; V(max), 28 ± 4 pmol · min(-1) · pmol of P450(-1)). The generation of enzymes with catalytically enhanced DTIC activation highlights the potential use of mutant CYP1A1 proteins in P450-based gene-directed enzyme prodrug therapy for the treatment of metastatic malignant melanoma.

  18. Immune tolerance improves the efficacy of enzyme replacement therapy in canine mucopolysaccharidosis I

    PubMed Central

    Dickson, Patricia; Peinovich, Maryn; McEntee, Michael; Lester, Thomas; Le, Steven; Krieger, Aimee; Manuel, Hayden; Jabagat, Catherine; Passage, Merry; Kakkis, Emil D.

    2008-01-01

    Mucopolysaccharidoses (MPSs) are lysosomal storage diseases caused by a deficit in the enzymes needed for glycosaminoglycan (GAG) degradation. Enzyme replacement therapy with recombinant human α-l-iduronidase successfully reduces lysosomal storage in canines and humans with iduronidase-deficient MPS I, but therapy usually also induces antibodies specific for the recombinant enzyme that could reduce its efficacy. To understand the potential impact of α-l-iduronidase–specific antibodies, we studied whether inducing antigen-specific immune tolerance to iduronidase could improve the effectiveness of recombinant iduronidase treatment in canines. A total of 24 canines with MPS I were either tolerized to iduronidase or left nontolerant. All canines received i.v. recombinant iduronidase at the FDA-approved human dose or a higher dose for 9–44 weeks. Nontolerized canines developed iduronidase-specific antibodies that proportionally reduced in vitro iduronidase uptake. Immune-tolerized canines achieved increased tissue enzyme levels at either dose in most nonreticular tissues and a greater reduction in tissue GAG levels, lysosomal pathology, and urinary GAG excretion. Tolerized MPS I dogs treated with the higher dose received some further benefit in the reduction of GAGs in tissues, urine, and the heart valve. Therefore, immune tolerance to iduronidase improved the efficacy of enzyme replacement therapy with recombinant iduronidase in canine MPS I and could potentially improve outcomes in patients with MPS I and other lysosomal storage diseases. PMID:18654665

  19. Hyperthyrotropinemia in newly diagnosed cystic fibrosis patients with pancreatic insufficiency reversed by enzyme therapy.

    PubMed

    Giannakopoulos, Aris; Katelaris, Anni; Noni, Maria; Karakonstantakis, Theodore; Kanaka-Gantenbein, Christina; Doudounakis, Stavros

    2018-05-01

    Patients with cystic fibrosis (CF) commonly present with an elevated TSH concentration, suggesting subclinical hypothyroidism. Its relation to concomitant pancreatic insufficiency and its natural course upon initiation of enzyme replacement have not been adequately studied. Herein, we investigated the thyroid function in newly diagnosed infants with CF and monitored the course of thyroid function response to pancreatic enzyme substitution treatment. Fourteen, newly diagnosed infants with CF and pancreatic insufficiency, were followed every 6-8 weeks for 6 months ensuing onset of pancreatic enzyme substitution therapy. All infants had normal TSH values on neonatal screening. Ten out of 14 (71%) had hyperthyrotropinemia and normal freeT4 values at presentation. No patient received thyroxine. Upon follow-up, after 6 months, TSH values normalized in 90% of infants with CF and hyperthyrotropinemia. Serum selenium levels were negatively correlated with TSH levels. Mild TSH elevation is a frequent finding in newly diagnosed cystic fibrosis patients with pancreatic insufficiency during infancy. TSH elevation resolves in most cases after initiation of enzyme substitution and improvement of nutritional status without any substitutive therapy with thyroxine. What is Known: • Newly diagnosed infants with cystic fibrosis often present with a state of hyperthyrotropinemia suggesting subclinical hypothyroidism. What is New: • Pancreatic enzyme substitution and improvement of nutrition restores normal TSH levels without the need of thyroxine therapy.

  20. Modulation of porcine biotransformation enzymes by anthelmintic therapy with fenbendazole and flubendazole.

    PubMed

    Savlík, M; Fimanová, K; Szotáková, B; Lamka, J; Skálová, L

    2006-06-01

    Fenbendazole (FEN) and flubendazole (FLU) are benzimidazole anthelmintics often used in pig management for the control of nematodoses. The in vivo study presented here was designed to test the influence of FLU and FEN on cytochrome P4501A and other cytochrome P450 (CYP) isoforms, UDP-glucuronosyl transferase and several carbonyl reducing enzymes. The results indicated that FEN (in a single therapeutic dose as well as in repeated therapeutic doses) caused significant induction of pig CYP1A, while FLU did not show an inductive effect towards this isoform. Some of the other hepatic and intestinal biotransformation enzymes that were assayed were moderately influenced by FEN or FLU. Strong CYP1A induction following FEN therapy in pigs may negatively affect the efficacy and pharmacokinetics of FEN itself or other simultaneously or consecutively administered drugs. From the perspective of biotransformation enzyme modulation, FLU would appear to be a more convenient anthelmintic therapy of pigs than FEN.

  1. Antiproteinuric therapy and fabry nephropathy: sustained reduction of proteinuria in patients receiving enzyme replacement therapy with agalsidase-beta.

    PubMed

    Tahir, Hindia; Jackson, Leslie L; Warnock, David G

    2007-09-01

    This report describes an open-label, nonrandomized, prospective evaluation of the effects of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker therapy on patients who have Fabry disease and also received enzyme replacement therapy with agalsidase-beta, given at 1 mg/kg body wt every 2 wk. Previous placebo-controlled phase III and phase IV trials with agalsidase-beta demonstrated clearing of globotriaosylceramide from vascular endothelia but little effect on proteinuria or progressive loss of kidney function in patients with Fabry disease and severe chronic kidney disease marked by overt proteinuria and/or estimated GFR <60 ml/min per 1.73 m2. Angiotensin-converting enzyme inhibitor and/or angiotensin receptor blocker therapy is the standard of care for patients with proteinuric kidney diseases, but their use is challenging in patients with Fabry disease and low or low-normal baseline systemic BP. A group of patients with Fabry disease were treated with antiproteinuric therapy, in conjunction with agalsidase-beta; sustained reductions in proteinuria with stabilization of kidney function were achieved in a group of six patients who had severe Fabry nephropathy; the progression rate was -0.23 +/- 1.12 ml/min per 1.73 m2 per yr with 30 mo of follow-up.

  2. N,N'-dihydroxyamidines: a new prodrug principle to improve the oral bioavailability of amidines.

    PubMed

    Reeh, Christiane; Wundt, Judith; Clement, Bernd

    2007-12-27

    N, N'-dihydroxybenzamdine represents a model compound for a new prodrug principle to improve the oral bioavailability of drugs containing amidine functions. The activation of the prodrug could be demonstrated in vitro by porcine and human subcellular enzyme fractions, the mitochondrial benzamidoxime reducing system, and porcine hepatocytes. In vivo, the bioavailability of benzamidine after oral application of N, N'-dihydroxybenzamidine was about 91% and exceeded that of benzamidine after oral application of benzamidoxime, being about 74% (Liu, L.; Ling, Y.; Havel, C.; Bashnick, L.; Young, W.; Rai, R.; Vijaykumar, D.; Riggs, J. R.; Ton, T.; Shaghafi, M.; Graupe, D.; Mordenti, J.; Sukbuntherng, J. Species comparison of in vitro and in vivo conversion of five N-hydroxyamidine prodrugs of fVIIA inhibitors to their corresponding active amidines. Presented at the 13th North America ISSX Meeting, Maui, HI, 2005).

  3. Formulated Delivery of Enzyme/Prodrug and Cytokine Gene Therapy to Promote Immune Reduction of Treated and Remote Tumors in Mouse Models of Prostate Cancer

    DTIC Science & Technology

    2007-01-01

    Cunha GR, Donjacour AA, Matusik RJ, Rosen JM. Prostate cancer in a transgenic mouse . Proc Natl Acad Sci U S A.1995;92(8):3439- 43 . Kanai F...data not shown). GFP expression in all cell lines was confirmed by UV microscopy and flow cytometry . Evaluation of RM1 cells for assessment of CDUPRT...for prostate cancer in a mouse model that imitates the development of human disease. J. Gene Med. (2004) 6(1): 43 -54. 108. MARTINIELLO-WILKS R

  4. Chlorzoxazone esters of some non-steroidal anti-inflammatory (NSAI) carboxylic acids as mutual prodrugs: design, synthesis, pharmacological investigations and docking studies.

    PubMed

    Abdel-Azeem, Ahmed Z; Abdel-Hafez, Atef A; El-Karamany, Gamal S; Farag, Hassan H

    2009-05-15

    The discovery of the inducible isoform of cyclooxygenase enzyme (COX-2) spurred the search for anti-inflammatory agents devoid of the undesirable effects associated with classical NSAIDs. New chlorzoxazone ester prodrugs (6-8) of some acidic NSAIDs (1-3) were designed, synthesized and evaluated as mutual prodrugs with the aim of improving the therapeutic potency and retard the adverse effects of gastrointestinal origin. The structure of the synthesized mutual ester prodrugs (6-8) were confirmed by IR, (1)H NMR, mass spectroscopy (MS) and their purity was ascertained by TLC and elemental analyses. In vitro chemical stability revealed that the synthesized ester prodrugs (6-8) are chemically stable in hydrochloric acid buffer pH 1.2 as a non-enzymatic simulated gastric fluid (SGF) and in phosphate buffer pH 7.4 as non-enzymatic simulated intestinal fluid (SIF). In 80% human plasma, the mutual prodrugs were found to be susceptible to enzymatic hydrolysis at relatively faster rate (t(1/2) approximately 37 and 34 min for prodrugs 6 and 7, respectively). Mutual ester prodrugs (6-8) were evaluated for their anti-inflammatory and muscle relaxation activities. Scanning electromicrographs of the stomach showed that the ester prodrugs induced very little irritancy in the gastric mucosa of rats after oral administration for 4days. In addition, docking of the mutual ester prodrugs (6-8) into COX-2 active site was conducted in order to predict the affinity and orientation of these prodrugs at the enzyme active site.

  5. Self-Immolative Polycations as Gene Delivery Vectors and Prodrugs Targeting Polyamine Metabolism in Cancer

    PubMed Central

    2015-01-01

    Polycations are explored as carriers to deliver therapeutic nucleic acids. Polycations are conventionally pharmacological inert with the sole function of delivering therapeutic cargo. This study reports synthesis of a self-immolative polycation (DSS-BEN) based on a polyamine analogue drug N1,N11-bisethylnorspermine (BENSpm). The polycation was designed to function dually as a gene delivery carrier and a prodrug targeting dysregulated polyamine metabolism in cancer. Using a combination of NMR and HPLC, we confirm that the self-immolative polycation undergoes intracellular degradation into the parent drug BENSpm. The released BENSpm depletes cellular levels of spermidine and spermine and upregulates polyamine catabolic enzymes spermine/spermidine N1-acetyltransferase (SSAT) and spermine oxidase (SMO). The synthesized polycations form polyplexes with DNA and facilitate efficient transfection. Taking advantage of the ability of BENSpm to sensitize cancer cells to TNFα-induced apoptosis, we show that DSS-BEN enhances the cell killing activity of TNFα gene therapy. The reported findings validate DSS-BEN as a dual-function delivery system that can deliver a therapeutic gene and improve the outcome of gene therapy as a result of the intracellular degradation of DSS-BEN to BENSpm and the subsequent beneficial effect of BENSpm on dysregulated polyamine metabolism in cancer. PMID:25153488

  6. Preparation, characterization and in vitro evaluation of a new nucleotide analogue prodrug cyclodextrin inclusion complexes.

    PubMed

    Diab, Roudayna; Jordheim, Lars P; Degobert, Ghania; Peyrottes, Suzanne; Périgaud, Christian; Dumontet, Charles; Fessi, Hatem

    2009-01-01

    Bis(tbutyl-S-acyl-2-thioethyl)-cytidine monophosophate is a new cytotoxic mononucleotide prodrug which have been developed to reverse the cellular resistance to nucleoside analogues. Unfortunately, its in vivo utilisation was hampered by its poor water solubility, raising the need of a molecular vector capable to mask its physicochemical characteristics although without affecting its cytotoxic activity. Hydroxypropyl-beta-cyclodextrin was used to prepare the prodrug inclusion complexes, allowing it to be solubilized in water and hence to be used for in vitro and in vivo experiments. A molar ratio of the cyclodextrin: prodrug of 3 was sufficient to obtain complete solubilization of the prodrug. The inclusion complex was characterized by differential scanning calorimetry, which revealed the disappearance of the melting peak of the prodrug suggesting the formation of inclusion complex. Proton Nuclear Magnetic Resonance spectroscopy provided a definitive proof of the inclusion complex formation, which was evidenced by the large chemical shift displacements observed for protons located in the interior of the hydrophobic cyclodextrin cavity. The complex retained its cytotoxic activity as shown by in vitro cell survival assays on murine leukemia cells. These results provided a basis for potential therapeutic applications of co-formulation of this new nucleotide analogue with hydroxypropyl-beta-CD in cancer therapy.

  7. Does early use of enzyme replacement therapy alter the natural history of mucopolysaccharidosis I? Experience in three siblings.

    PubMed

    Laraway, Sarah; Breen, Catherine; Mercer, Jean; Jones, Simon; Wraith, James E

    2013-07-01

    Enzyme replacement therapy is widely used as treatment for mucopolysaccharidosis I (MPS I), and there is evidence that this produces improvement in certain clinical domains. There does appear to be variation in the response of clinical features to treatment once these are established. In a reported sibling pair, when enzyme replacement therapy was commenced pre-symptomatically in the younger child, the natural history of the condition appeared to be affected. We present data from three siblings treated with enzyme replacement therapy at different ages which supports this finding. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Design and Synthesis of Phosphotyrosine Peptidomimetic Prodrugs

    PubMed Central

    Garrido-Hernandez, Hugo; Moon, Kyung D.; Geahlen, Robert L.; Borch, Richard F.

    2008-01-01

    A novel approach to the intracellular delivery of aryl phosphates has been developed that utilizes a phosphoramidate-based prodrug approach. The prodrugs contain an ester group that undergoes reductive activation intracellularly with concomitant expulsion of a phosphoramidate anion. This anion undergoes intramolecular cyclization and hydrolysis to generate aryl phosphate exclusively with a t1/2 = ∼ 20 min. Phosphoramidate prodrugs (8-10) of phosphate-containing peptidomimetics that target the SH2 domain were synthesized. Evaluation of these peptidomimetic prodrugs in a growth inhibition assay and, in a cell-based transcriptional assay, demonstrated that the prodrugs had IC50 values in the low micromolar range. Synthesis of phosphorodiamidate analogs containing a P-NH-Ar linker (16 – 18) was also carried out in the hope that the phosphoramidates released might be phosphatase-resistant. Comparable activation rates and cell-based activities were observed for these prodrugs, but the intermediate phosphoramidate dianion underwent spontaneous hydrolysis with a t1/2 = ∼ 30 min. PMID:16722656

  9. Update on the Genetic Polymorphisms of Drug-Metabolizing Enzymes in Antiepileptic Drug Therapy

    PubMed Central

    Saruwatari, Junji; Ishitsu, Takateru; Nakagawa, Kazuko

    2010-01-01

    Genetic polymorphisms in the genes that encode drug-metabolizing enzymes are implicated in the inter-individual variability in the pharmacokinetics and pharmaco-dynamics of antiepileptic drugs (AEDs). However, the clinical impact of these polymorphisms on AED therapy still remains controversial. The defective alleles of cytochrome P450 (CYP) 2C9 and/or CYP2C19 could affect not only the pharmacokinetics, but also the pharmacodynamics of phenytoin therapy. CYP2C19 deficient genotypes were associated with the higher serum concentration of an active metabolite of clobazam, N-desmethylclobazam, and with the higher clinical efficacy of clobazam therapy than the other CYP2C19 genotypes. The defective alleles of CYP2C9 and/or CYP2C19 were also found to have clinically significant effects on the inter-individual variabilities in the population pharmacokinetics of phenobarbital, valproic acid and zonisamide. EPHX1 polymorphisms may be associated with the pharmacokinetics of carbamazepine and the risk of phenytoin-induced congenital malformations. Similarly, the UDP-glucuronosyltransferase 2B7 genotype may affect the pharmacokinetics of lamotrigine. Gluthatione S-transferase null genotypes are implicated in an increased risk of hepatotoxicity caused by carbamazepine and valproic acid. This article summarizes the state of research on the effects of mutations of drug-metabolizing enzymes on the pharmacokinetics and pharmacodynamics of AED therapies. Future directions for the dose-adjustment of AED are discussed. PMID:27713373

  10. A Chaperone Enhances Blood α-Glucosidase Activity in Pompe Disease Patients Treated With Enzyme Replacement Therapy

    PubMed Central

    Parenti, Giancarlo; Fecarotta, Simona; la Marca, Giancarlo; Rossi, Barbara; Ascione, Serena; Donati, Maria Alice; Morandi, Lucia Ovidia; Ravaglia, Sabrina; Pichiecchio, Anna; Ombrone, Daniela; Sacchini, Michele; Pasanisi, Maria Barbara; De Filippi, Paola; Danesino, Cesare; Della Casa, Roberto; Romano, Alfonso; Mollica, Carmine; Rosa, Margherita; Agovino, Teresa; Nusco, Edoardo; Porto, Caterina; Andria, Generoso

    2014-01-01

    Enzyme replacement therapy is currently the only approved treatment for Pompe disease, due to acid α-glucosidase deficiency. Clinical efficacy of this approach is variable, and more effective therapies are needed. We showed in preclinical studies that chaperones stabilize the recombinant enzyme used for enzyme replacement therapy. Here, we evaluated the effects of a combination of enzyme therapy and a chaperone on α-glucosidase activity in Pompe disease patients. α-Glucosidase activity was analyzed by tandem-mass spectrometry in dried blood spots from patients treated with enzyme replacement therapy, either alone or in combination with the chaperone N-butyldeoxynojirimycin given at the time of the enzyme infusion. Thirteen patients with different presentations (3 infantile-onset, 10 late-onset) were enrolled. In 11 patients, the combination treatment resulted in α-glucosidase activities greater than 1.85-fold the activities with enzyme replacement therapy alone. In the whole patient population, α-glucosidase activity was significantly increased at 12 hours (2.19-fold, P = 0.002), 24 hours (6.07-fold, P = 0.001), and 36 hours (3.95-fold, P = 0.003). The areas under the curve were also significantly increased (6.78-fold, P = 0.002). These results suggest improved stability of recombinant α-glucosidase in blood in the presence of the chaperone. PMID:25052852

  11. Gastrointestinal manifestations of Fabry disease: clinical response to enzyme replacement therapy.

    PubMed

    Banikazemi, Maryam; Ullman, Thomas; Desnick, Robert J

    2005-08-01

    Gastrointestinal symptoms are often an early and prominent manifestation of Fabry disease, an X-linked inborn error of metabolism caused by the deficient activity of the lysosomal enzyme, alpha-galactosidase A. This enzyme deficiency results in the progressive accumulation of globotriaosylceramide and other glycosphingolipids in tissue lysosomes throughout the body. In classically affected patients, glycosphingolipid accumulation in the vascular endothelium eventually culminates in life-threatening renal, cardiac, and cerebrovascular disease. In addition, over 50% of patients experience post-prandial abdominal pain and diarrhea that interferes with the ability to work and quality of life. Here, we describe four males aged 17-40 years with classic Fabry disease and severe gastrointestinal symptoms who participated in clinical trials of enzyme replacement therapy with agalsidase beta (Fabrazyme, 1 mg/kg every 2 weeks). Before therapy, the three adult patients experienced post-prandial abdominal pain, bloating, and severe diarrhea with 7-10 bowel movements per day every day and the 17-year-old had weekly episodes of diarrhea with six bowel movements per day. Other symptoms included vomiting, food intolerance, and poor weight gain. All patients took medications for these symptoms (diphenoxylate-atropine [Lomotil], ranitidine hydrochloride [Zantac], or sulfasalazine). After 6-7 months of agalsidase beta therapy, all patients reported "no or only occasional" abdominal pain or diarrhea, had discontinued their gastrointestinal medications, and had gained 3-8 kg. These marked improvements in gastrointestinal symptoms have persisted for over 3 years of treatment. In such patients, enzyme replacement at 1 mg/kg effects an early and significant clinical improvement in the gastrointestinal manifestations of Fabry disease.

  12. Phenylalanine ammonia lyase, enzyme substitution therapy for phenylketonuria, where are we now?

    PubMed

    Sarkissian, Christineh N; Gámez, Alejandra

    2005-12-01

    Phenylketonuria (PKU) is an autosomal recessive genetic disorder in which mutations in the phenylalanine-4-hydroxylase (PAH) gene result in an inactive enzyme (PAH, EC 1.14.16.1). The effect is an inability to metabolize phenylalanine (Phe), translating into elevated levels of Phe in the bloodstream (hyperphenylalaninemia). If therapy is not implemented at birth, mental retardation can occur. PKU patients respond to treatment with a low-phenylalanine diet, but compliance with the diet is difficult, therefore the development of alternative treatments is desirable. Enzyme substitution therapy with a recombinant phenylalanine ammonia lyase (PAL) is currently being explored. This enzyme converts Phe to the harmless metabolites, trans-cinnamic acid and trace ammonia. Taken orally and when non-absorbable and protected, PAL lowers plasma Phe in mutant hyperphenylalaninemic mouse models. Subcutaneous administration of PAL results in more substantial lowering of plasma and significant reduction in brain Phe levels, however the metabolic effect is not sustained following repeated injections due to an immune response. We have chemically modified PAL by pegylation to produce a protected form of PAL that possesses better specific activity, prolonged half-life, and reduced immunogenicity in vivo. Subcutaneous administration of pegylated molecules to PKU mice has the desired metabolic response (prolonged reduction in blood Phe levels) with greatly attenuated immunogenicity.

  13. Pharmacogenetics of drug-metabolizing enzymes: implications for a safer and more effective drug therapy

    PubMed Central

    Ingelman-Sundberg, Magnus; Rodriguez-Antona, Cristina

    2005-01-01

    The majority of phase I- and phase II-dependent drug metabolism is carried out by polymorphic enzymes which can cause abolished, quantitatively or qualitatively decreased or enhanced drug metabolism. Several examples exist where subjects carrying certain alleles do not benefit from drug therapy due to ultrarapid metabolism caused by multiple genes or by induction of gene expression or, alternatively, suffer from adverse effects of the drug treatment due to the presence of defective alleles. It is likely that future predictive genotyping for such enzymes might benefit 15–25% of drug treatments, and thereby allow prevention of adverse drug reactions and causalities, and thus improve the health of a significant fraction of the patients. However, it will take time before this will be a reality within the clinic. We describe some important aspects in the field with emphasis on cytochrome P450 and discuss also polymorphic aspects of foetal expression of CYP3A5 and CYP3A7. PMID:16096104

  14. Pro-drugs for indirect cannabinoids as therapeutic agents.

    PubMed

    Ashton, John

    2008-10-01

    Medicinal cannabis, cannabis extracts, and other cannabinoids are currently in use or under clinical trial investigation for the control of nausea, emesis and wasting in patients undergoing chemotherapy, the control of neuropathic pain and arthritic pain, and the control of the symptoms of multiple sclerosis. The further development of medicinal cannabinoids has been challenged with problems. These include the psychoactivity of cannabinoid CB1 receptor agonists and the lack of availability of highly selective cannabinoid receptor full agonists (for the CB1 or CB2 receptor), as well as problems of pharmacokinetics. Global activation of cannabinoid receptors is usually undesirable, and so enhancement of local endocannabinoid receptor activity with indirect cannabimimetics is an attractive strategy for therapeutic modulation of the endocannabinoid system. However, existing drugs of this type tend to be metabolized by the same enzymes as their target endocannabinoids and are not yet available in a form that is clinically useful. A potential solution to these problems may now have been suggested by the discovery that paracetamol (acetaminophen) exerts its analgesic (and probably anti-pyretic) effects by its degradation into an anandamide (an endocannabinoid) reuptake inhibitor (AM404) within the body, thus classifying it as pro-drug for an indirect cannabimimetic. Given the proven efficacy and safety of paracetamol, the challenge now is to develop related drugs, or entirely different substrates, into pro-drug indirect cannabimimetics with a similar safety profile to paracetamol but at high effective dose titrations.

  15. [Radiation Anticarcinogenesis by Thiazolidine Pro-drug

    NASA Technical Reports Server (NTRS)

    Warters, Raymond L.; Roberts, Jeanette C.; Fain, Heidi

    1999-01-01

    The original goal of this work was to determine the capacity of selected aminothiols to modulate radiation induced cytotoxicity, mutagenesis and carcinogenesis in a human mammary epithelial cell line. The conclusions from this work are that WR-1065 is the "gold standard" for protection against radiation induced cytotoxicity, mutagenesis and carcinogenesis. While a potent radiation protector, WR-1065 is cytotoxic in vitro and in vivo. Our rationale for a study of the thiazolidine pro-drugs was that these compounds are neither toxic in vitro or in vivo. The results obtained during this funding period indicate that the thiazolidine pro-drugs are as potent as WR-1065 as protectors against radiation induced mutation induction, and thus presumably against radiation induced carcinogenesis. Our results indicate that the thiazolidine prodrugs are excellent candidates to test as non-toxic anticarcinogens for protecting astronauts from cancer induction during space travel.

  16. A biochemical and pharmacological comparison of enzyme replacement therapies for the glycolipid storage disorder Fabry disease.

    PubMed

    Lee, Karen; Jin, Xiaoying; Zhang, Kate; Copertino, Lorraine; Andrews, Laura; Baker-Malcolm, Jennifer; Geagan, Laura; Qiu, Huawei; Seiger, Keirsten; Barngrover, Debra; McPherson, John M; Edmunds, Tim

    2003-04-01

    Fabry disease is a lysosomal storage disease arising from deficiency of the enzyme alpha-galactosidase A. Two recombinant protein therapeutics, Fabrazyme (agalsidase beta) and Replagal (agalsidase alfa), have been approved in Europe as enzyme replacement therapies for Fabry disease. Both contain the same human enzyme, alpha-galactosidase A, but they are produced using different protein expression systems and have been approved for administration at different doses. To determine if there is recognizable biochemical basis for the different doses, we performed a comparison of the two drugs, focusing on factors that are likely to influence biological activity and availability. The two drugs have similar glycosylation, both in the type and location of the oligosaccharide structures present. Differences in glycosylation were mainly limited to the levels of sialic acid and mannose-6-phosphate present, with Fabrazyme having a higher percentage of fully sialylated oligosaccharides and a higher level of phosphorylation. The higher levels of phosphorylated oligomannose residues correlated with increased binding to mannose-6-phosphate receptors and uptake into Fabry fibroblasts in vitro. Biodistribution studies in a mouse model of Fabry disease showed similar organ uptake. Likewise, antigenicity studies using antisera from Fabry patients demonstrated that both drugs were indistinguishable in terms of antibody cross-reactivity. Based on these studies and present knowledge regarding the influence of glycosylation on protein biodistribution and cellular uptake, the two protein preparations appear to be functionally indistinguishable. Therefore, the data from these studies provide no rationale for the use of these proteins at different therapeutic doses.

  17. Prodrugs of herpes simplex thymidine kinase inhibitors.

    PubMed

    Yanachkova, Milka; Xu, Wei-Chu; Dvoskin, Sofya; Dix, Edward J; Yanachkov, Ivan B; Focher, Federico; Savi, Lida; Sanchez, M Dulfary; Foster, Timothy P; Wright, George E

    2015-04-01

    Because guanine-based herpes simplex virus thymidine kinase inhibitors are not orally available, we synthesized various 6-deoxy prodrugs of these compounds and evaluated them with regard to solubility in water, oral bioavailability, and efficacy to prevent herpes simplex virus-1 reactivation from latency in a mouse model. Organic synthesis was used to prepare compounds, High Performance Liquid Chromatography (HPLC) to analyze hydrolytic conversion, Mass Spectrometry (MS) to measure oral bioavailability, and mouse latent infection and induced reactivation to evaluate the efficacy of a specific prodrug. Aqueous solubilities of prodrugs were improved, oxidation of prodrugs by animal cytosols occurred in vitro, and oral absorption of the optimal prodrug sacrovir™ (6-deoxy-mCF3PG) in the presence of the aqueous adjuvant Soluplus® and conversion to active compound N(2)-[3-(trifluoromethyl)pheny])guanine (mCF3PG) were accomplished in mice. Treatment of herpes simplex virus-1 latent mice with sacrovir™ in 1% Soluplus in drinking water significantly suppressed herpes simplex virus-1 reactivation and viral genomic replication. Ad libitum oral delivery of sacrovir™ was effective in suppressing herpes simplex virus-1 reactivation in ocularly infected latent mice as measured by the numbers of mice shedding infectious virus at the ocular surface, numbers of trigeminal ganglia positive for infectious virus, number of corneas that had detectable infectious virus, and herpes simplex virus-1 genome copy numbers in trigeminal ganglia following reactivation. These results demonstrate the statistically significant effect of the prodrug on suppressing herpes simplex virus-1 reactivation in vivo. © The Author(s) 2015.

  18. Fabry disease, enzyme replacement therapy and the significance of antibody responses.

    PubMed

    Deegan, Patrick B

    2012-03-01

    Fabry disease is an X-linked disorder caused by a deficiency of α-galactosidase A. This leads to a progressive accumulation of globotriaosylceramide in tissues throughout the body. Cardiac, renal and neurological manifestations are common and life expectancy is significantly reduced relative to the general population. Management of Fabry disease involves the administration of intravenous enzyme replacement therapy (ERT). Two forms - agalsidase alfa and agalsidase beta - have been licensed in certain jurisdictions and are generally well tolerated; however, some patients develop antibodies to the infused enzyme, which may impair the efficacy and safety of treatment. Agalsidase alfa and agalsidase beta are produced in different systems; this leads to certain differences in post-translational modification that may affect immunogenicity. Immunoglobulin (Ig) G antibodies have frequently been reported in patients with Fabry disease receiving ERT; IgG responses are reported in a greater proportion of patients receiving agalsidase beta than in patients receiving agalsidase alfa. IgE antibodies are less common than IgG antibodies, and have not been observed in patients receiving agalsidase alfa. However, these data are difficult to interpret due to methodological differences in the assessment of seropositivity, and in the doses of enzyme used. The clinical impact of the development of IgG antibodies to ERT in patients with Fabry disease remains unclear, due to lack of data and to the marked heterogeneity of patients both in terms of disease manifestations and response to therapy. Further studies that examine the development of antibodies in patients with Fabry disease and the potential impact of such antibodies on the outcome of ERT are necessary.

  19. [In vitro metabolism of fenbendazole prodrug].

    PubMed

    Wen, Ai-Dan; Duan, Li-Ping; Liu, Cong-Shan; Tao, Yi; Xue, Jian; Wu, Ning-Bo; Jiang, Bin; Zhang, Hao-Bing

    2013-02-01

    Synthesized fenbendazole prodrug N-methoxycarbonyl-N'-(2-nitro-4-phenylthiophenyl) thiourea (MPT) was analyzed in vitro in artificial gastric juice, intestinal juice and mouse liver homogenate model by using HPLC method, and metabolic curve was then generated. MPT was tested against Echinococcus granulosus protoscolices in vitro. The result showed that MPT could be metabolized in the three biological media, and to the active compound fenbendazole in liver homogenate, with a metabolic rate of 7.92%. Besides, the prodrug showed a weak activity against E. granulosus protoscolices with a mortality of 45.9%.

  20. Amino acids as promoieties in prodrug design and development.

    PubMed

    Vig, Balvinder S; Huttunen, Kristiina M; Laine, Krista; Rautio, Jarkko

    2013-10-01

    Prodrugs are biologically inactive agents that upon biotransformation in vivo result in active drug molecules. Since prodrugs might alter the tissue distribution, efficacy and the toxicity of the parent drug, prodrug design should be considered at the early stages of preclinical development. In this regard, natural and synthetic amino acids offer wide structural diversity and physicochemical properties. This review covers the use of amino acid prodrugs to improve poor solubility, poor permeability, sustained release, intravenous delivery, drug targeting, and metabolic stability of the parent drug. In addition, practical considerations and challenges associated with the development of amino acid prodrugs are also covered. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Synthesis and antimalarial evaluation of prodrugs of novel fosmidomycin analogues.

    PubMed

    Faísca Phillips, Ana Maria; Nogueira, Fátima; Murtinheira, Fernanda; Barros, Maria Teresa

    2015-01-01

    The continuous development of drug resistance by Plasmodium falciparum, the agent responsible for the most severe forms of malaria, creates the need for the development of novel drugs to fight this disease. Fosmidomycin is an effective antimalarial and potent antibiotic, known to act by inhibiting the enzyme 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), essential for the synthesis of isoprenoids in eubacteria and plasmodia, but not in humans. In this study, novel constrained cyclic prodrug analogues of fosmidomycin were synthesized. One, in which the hydroxamate function is incorporated into a six-membered ring, was found have higher antimalarial activity than fosmidomycin against the chloroquine and mefloquine resistant P. falciparum Dd2 strain. In addition, it showed very low cytotoxicity against cultured human cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Enzyme-triggered size shrink and laser-enhanced NO release nanoparticles for deep tumor penetration and combination therapy.

    PubMed

    Hu, Chuan; Cun, Xingli; Ruan, Shaobo; Liu, Rui; Xiao, Wei; Yang, Xiaotong; Yang, Yuanyuan; Yang, Chuanyao; Gao, Huile

    2018-06-01

    Chemotherapy remains restricted by poor drug delivery efficacy due to the heterogenous nature of tumor. Herein, we presented a novel nanoparticle that could not only response to the tumor microenvironment but also modulate it for deep tumor penetration and combination therapy. The intelligent nanoparticle (IDDHN) was engineered by hyaluronidase (HAase)-triggered size shrinkable hyaluronic acid shells, which were modified with NIR laser sensitive nitric oxide donor (HN), small-sized dendrimeric prodrug (IDD) of doxorubicin (DOX) as chemotherapy agent and indocyanine green (ICG) as photothermal agent into a single nanoparticle. IDDHN displayed synergistic deep penetration both in vitro and in vivo, owing to the enzymatically degradable HN shell mediated by HAase and laser-enhanced NO release triggered deep penetration upon strong hyperthermia effect of ICG under the NIR laser irradiation. The therapeutic effect of IDDHN was verified in 4T1 xenograft tumor model, and IDDHN showed a much better antitumor efficiency with few side effects upon NIR laser irradiation. Therefore, the valid of this study might provide a novel tactic for engineering nanoparticles both response to and modulate the tumor microenvironment for improving penetration and heterogeneity distribution of therapeutic agents in tumor. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Improvement of dysphagia in a child affected by Pompe disease treated with enzyme replacement therapy

    PubMed Central

    2013-01-01

    Aim Dysphagia is a known complication in Pompe Disease (PD), a severe metabolic myopathy due to alpha-glucosidase deficiency. Enzyme replacement therapy (ERT) with alglucosidase alfa is the only approved therapy for PD. Presently no data are available on the effects of ERT on dysphagia in PD patients. The aim of this work is to evaluate the course of this complication in a 6 years old boy affected by PD after treatment with ERT. Methods Dysphagia was assessed by Videofluoroscopic Swallowing Study (VFSS) at baseline, before the start of ERT and after 36 months of therapy. We used the Dysphagia Severity Rating Scale (DSS) to define the severity grade of dysphagia. Results VFSS performed at baseline revealed complete incoordination of oral stage swallowing which was classified as a grade 1 dysphagia according to DSS. After 36 months of treatment VFSS revealed normal swallowing, classified as grade 0 by DSS. Conclusion Our results suggest that ERT is effective in improving dysphagia. VFSS may be a useful tool to investigate and monitor swallowing disorders in patients affected by PD. PMID:23668440

  4. Gene therapy/bone marrow transplantation in ADA-deficient mice: roles of enzyme-replacement therapy and cytoreduction.

    PubMed

    Carbonaro, Denise A; Jin, Xiangyang; Wang, Xingchao; Yu, Xiao-Jin; Rozengurt, Nora; Kaufman, Michael L; Wang, Xiaoyan; Gjertson, David; Zhou, Yang; Blackburn, Michael R; Kohn, Donald B

    2012-11-01

    Gene therapy (GT) for adenosine deaminase-deficient severe combined immune deficiency (ADA-SCID) can provide significant long-term benefit when patients are given nonmyeloablative conditioning and ADA enzyme-replacement therapy (ERT) is withheld before autologous transplantation of γ-retroviral vector-transduced BM CD34+ cells. To determine the contributions of conditioning and discontinuation of ERT to the therapeutic effects, we analyzed these factors in Ada gene knockout mice (Ada(-/-)). Mice were transplanted with ADA-deficient marrow transduced with an ADA-expressing γ-retroviral vector without preconditioning or after 200 cGy or 900 cGy total-body irradiation and evaluated after 4 months. In all tissues analyzed, vector copy numbers (VCNs) were 100- to 1000-fold greater in mice receiving 900 cGy compared with 200 cGy (P < .05). In mice receiving 200 cGy, VCN was similar whether ERT was stopped or given for 1 or 4 months after GT. In unconditioned mice, there was decreased survival with and without ERT, and VCN was very low to undetectable. When recipients were conditioned with 200 cGy and received transduced lineage-depleted marrow, only recipients receiving ERT (1 or 4 months) had detectable vector sequences in thymocytes. In conclusion, cytoreduction is important for the engraftment of gene-transduced HSC, and short-term ERT after GT did not diminish the capacity of gene-corrected cells to engraft and persist.

  5. Gene therapy/bone marrow transplantation in ADA-deficient mice: roles of enzyme-replacement therapy and cytoreduction

    PubMed Central

    Jin, Xiangyang; Wang, Xingchao; Yu, Xiao-Jin; Rozengurt, Nora; Kaufman, Michael L.; Wang, Xiaoyan; Gjertson, David; Zhou, Yang; Blackburn, Michael R.; Kohn, Donald B.

    2012-01-01

    Gene therapy (GT) for adenosine deaminase–deficient severe combined immune deficiency (ADA-SCID) can provide significant long-term benefit when patients are given nonmyeloablative conditioning and ADA enzyme-replacement therapy (ERT) is withheld before autologous transplantation of γ-retroviral vector-transduced BM CD34+ cells. To determine the contributions of conditioning and discontinuation of ERT to the therapeutic effects, we analyzed these factors in Ada gene knockout mice (Ada−/−). Mice were transplanted with ADA-deficient marrow transduced with an ADA-expressing γ-retroviral vector without preconditioning or after 200 cGy or 900 cGy total-body irradiation and evaluated after 4 months. In all tissues analyzed, vector copy numbers (VCNs) were 100- to 1000-fold greater in mice receiving 900 cGy compared with 200 cGy (P < .05). In mice receiving 200 cGy, VCN was similar whether ERT was stopped or given for 1 or 4 months after GT. In unconditioned mice, there was decreased survival with and without ERT, and VCN was very low to undetectable. When recipients were conditioned with 200 cGy and received transduced lineage-depleted marrow, only recipients receiving ERT (1 or 4 months) had detectable vector sequences in thymocytes. In conclusion, cytoreduction is important for the engraftment of gene-transduced HSC, and short-term ERT after GT did not diminish the capacity of gene-corrected cells to engraft and persist. PMID:22833548

  6. Targeting Carcinoma-Associated Fibroblasts Within the Tumor Stroma With a Fibroblast Activation Protein-Activated Prodrug

    PubMed Central

    2012-01-01

    : mean = 0.543mm3, 95% CI = 0.173 to 0.913mm3), respectively, on day 21 after therapy. Conclusions This study validates the proteolytic activity of FAP as a target for the activation of a systemically delivered cytotoxic prodrug and demonstrates that targeted killing of cells within the stromal compartment of the tumor microenvironment can produce a therapeutic response. PMID:22911669

  7. ROS-activated anticancer prodrugs: a new strategy for tumor-specific damage

    PubMed Central

    Peng, Xiaohua; Gandhi, Varsha

    2013-01-01

    Targeting tumor cells is an important strategy to improve the selectivity of cancer therapies. With the advanced studies in cancer biology, we know that cancer cells are usually under increased oxidative stress. The high level of reactive oxygen species in cancer cells has been exploited for developing novel therapeutic strategies to preferentially kill cancer cells. Our group, amongst others, have used boronic acids/esters as triggers for developing ROS-activated anticancer prodrugs that target cancer cells. The selectivity was achieved by combining a specific reaction between boronates and H2O2 with the efficient masking of drug toxicity in the prodrug via boronates. Prodrugs activated via ferrocene-mediated oxidation have also been developed to improve the selectivity of anticancer drugs. We describe how the strategies of ROS-activation can be used for further development of new ROS-targeting prodrugs, eventually leading to novel approaches and/or combined technology for more efficient and selective treatment of cancers. PMID:22900465

  8. Impact of enzyme replacement therapy and hematopoietic stem cell transplantation in patients with Morquio A syndrome

    PubMed Central

    Tomatsu, Shunji; Sawamoto, Kazuki; Alméciga-Díaz, Carlos J; Shimada, Tsutomu; Bober, Michael B; Chinen, Yasutsugu; Yabe, Hiromasa; Montaño, Adriana M; Giugliani, Roberto; Kubaski, Francyne; Yasuda, Eriko; Rodríguez-López, Alexander; Espejo-Mojica, Angela J; Sánchez, Oscar F; Mason, Robert W; Barrera, Luis A; Mackenzie, William G; Orii, Tadao

    2015-01-01

    Patients with mucopolysaccharidosis IVA (MPS IVA) can present with systemic skeletal dysplasia, leading to a need for multiple orthopedic surgical procedures, and often become wheelchair bound in their teenage years. Studies on patients with MPS IVA treated by enzyme replacement therapy (ERT) showed a sharp reduction on urinary keratan sulfate, but only modest improvement based on a 6-minute walk test and no significant improvement on a 3-minute climb-up test and lung function test compared with the placebo group, at least in the short-term. Surgical remnants from ERT-treated patients did not show reduction of storage materials in chondrocytes. The impact of ERT on bone lesions in patients with MPS IVA remains limited. ERT seems to be enhanced in a mouse model of MPS IVA by a novel form of the enzyme tagged with a bone-targeting moiety. The tagged enzyme remained in the circulation much longer than untagged native enzyme and was delivered to and retained in bone. Three-month-old MPS IVA mice treated with 23 weekly infusions of tagged enzyme showed marked clearance of the storage materials in bone, bone marrow, and heart valves. When treatment was initiated at birth, reduction of storage materials in tissues was even greater. These findings indicate that specific targeting of the enzyme to bone at an early stage may improve efficacy of ERT for MPS IVA. Recombinant N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in Escherichia coli BL21 (DE3) (erGALNS) and in the methylotrophic yeast Pichia pastoris (prGALNS) has been produced as an alternative to the conventional production in Chinese hamster ovary cells. Recombinant GALNS produced in microorganisms may help to reduce the high cost of ERT and the introduction of modifications to enhance targeting. Although only a limited number of patients with MPS IVA have been treated with hematopoietic stem cell transplantation (HSCT), beneficial effects have been reported. A wheelchair-bound patient with a severe form of MPS

  9. Catalase-loaded cisplatin-prodrug-constructed liposomes to overcome tumor hypoxia for enhanced chemo-radiotherapy of cancer.

    PubMed

    Zhang, Rui; Song, Xuejiao; Liang, Chao; Yi, Xuan; Song, Guosheng; Chao, Yu; Yang, Yu; Yang, Kai; Feng, Liangzhu; Liu, Zhuang

    2017-09-01

    Aiming at improved therapeutic efficacies, the combination of chemotherapy and radiotherapy (chemo-radiotherapy) has been widely studied and applied in clinic. However, the hostile characteristics of tumor microenvironment such as hypoxia often limit the efficacies in both types of cancer therapies. Herein, catalase (CAT), an antioxidant enzyme, is encapsulated inside liposomes constituted by cisplatin (IV)-prodrug-conjugated phospholipid, forming CAT@Pt (IV)-liposome for enhanced chemo-radiotherapy of cancer. After being loaded inside liposomes, CAT within CAT@Pt (IV)-liposome shows retained and well-protected enzyme activity, and is able to trigger decomposition of H 2 O 2 produced by tumor cells, so as to produce additional oxygen for hypoxia relief. As the result, treatment of CAT@Pt (IV)-liposome induces the highest level of DNA damage in cancer cells after X-ray radiation compared to the control groups. In vivo tumor treatment further demonstrates a remarkably improved therapeutic outcome in chemo-radiotherapy with such CAT@Pt (IV)-liposome nanoparticles. Hence, an exquisite type of liposome-based nanoparticles is developed in this work by integrating cisplatin-based chemotherapy and catalase-induced tumor hypoxia relief together for combined chemo-radiotherapy with great synergistic efficacy, promising for clinical translation in cancer treatment. Copyright © 2017. Published by Elsevier Ltd.

  10. Deubiquitinating enzymes in cancer stem cells: functions and targeted inhibition for cancer therapy.

    PubMed

    Kaushal, Kamini; Antao, Ainsley Mike; Kim, Kye-Seong; Ramakrishna, Suresh

    2018-06-01

    The ability of cancers to evade conventional treatments, such as chemotherapy and radiation therapy, has been attributed to a subpopulation of cancer stem cells (CSCs). CSCs are regulated by mechanisms similar to those that regulate normal stem cells (NSCs), including processes involving ubiquitination and deubiquitination enzymes (DUBs) that regulate the expression of various factors, such as Notch, Wnt, Sonic Hedgehog (Shh), and Hippo. In this review, we discuss the roles of various DUBs involved in the regulation of core stem cell transcription factors and CSC-related proteins that are implicated in the modulation of cellular processes and carcinogenesis. In addition, we discuss the various DUB inhibitors that have been designed to target processes relevant to cancer and CSC maintenance. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. A prospective 10-year study of individualized, intensified enzyme replacement therapy in advanced Fabry disease.

    PubMed

    Schiffmann, Raphael; Swift, Caren; Wang, Xuan; Blankenship, Derek; Ries, Markus

    2015-11-01

    To test the hypothesis that more frequent enzyme replacement therapy (ERT) slows the decline in kidney function in adult patients with Fabry disease. A single center open label 10-year prospective clinical trial of 12 patients with advanced Fabry disease who, after having experienced an ongoing decline in renal function after 2-4 years of receiving ERT at the approved dose of 0.2 mg/kg agalsidase alfa every other week (EOW), were switched to weekly (EW) ERT at the same dose. We used linear regression to fit each individual patient's longitudinal estimated glomerular filtration rate (eGFR) record in order to compare the deterioration rates between EOW and EW ERT. For the entire group, mean slope on agalsidase alfa every 2 weeks was -7.92 ± 2.88 ml/min/1.73 m(2)/year and 3.84 ± 4.08 ml/min/1.73 m(2)/year on weekly enzyme infusions (p = 0.01, two-tailed paired t test). Three patients (25 %) completed the entire study with relatively preserved renal function while 50 % of patients reached end-stage renal disease (ESRD) during the 10 years of this study. The estimated average delay to ESRD was 13.8 years [n = 11; 95 % CI 0.66, 27]. One patient had a positive eGFR slope on weekly infusions while the patient with the highest antibody titer had a steeper slope after switching. Mean globotriaosylceramide concentrations in urine and plasma as well as urine protein excretion remained unchanged. Weekly enzyme infusions slow the decline of renal function in a subgroup of more severe patients thus showing that existing ERT can be further optimized.

  12. Enzyme replacement therapy in newborn mucopolysaccharidosis IVA mice: early treatment rescues bone lesions?

    PubMed Central

    Tomatsu, Shunji; Montaño, Adriana M.; Oikawa, Hirotaka; Dung, Vu Chi; Hashimoto, Amiko; Oguma, Toshihiro; Takahashi, Tatsuo; Shimada, Tsutomu; Orii, Tadao; Sly, William S.

    2014-01-01

    We treated mucopolysaccharidosis IVA (MPS IVA) mice to assess the effects of long-term enzyme replacement therapy (ERT) initiated at birth, since adult mice treated by ERT showed little improvement in bone pathology (1). To conduct ERT in newborn mice, we used recombinant human N-acetylgalactosamine-6-sulfate sulfatase (GALNS) produced in a CHO cell line. First, to observe the tissue distribution pattern, a dose of 250 units/g body weight was administered intravenously in MPS IVA mice at day 2 or 3. The infused enzyme was primarily recovered in liver and spleen, with detectable activity in bone and brain. Second, newborn ERT was conducted after tissue distribution study. The first injection of newborn ERT was performed intravenously, the second to fourth weekly injections were intraperitoneal, and the remaining injections from 5th to 14th week were intravenous into the tail vein. MPS IVA mice treated with GALNS showed clearance of lysosomal storage in liver, spleen, and sinus lining cells in bone marrow. The column structure of the growth plate was organized better than adult mice treated with ERT; however, hyaline and fibrous cartilage cells in femur, spine, ligaments, discs, synovium, and periosteum still had storage materials to some extent. Heart valves were refractory to the treatment. Levels of serum keratan sulfate were kept normal in newborn ERT mice. In conclusion, the enzyme, which enters the cartilage before the cartilage cell layer becomes mature, prevents disorganization of column structure. Early treatment from birth leads to partial remission of bone pathology in MPS IVA mouse. PMID:24953405

  13. Efficacy of pancreatic enzyme replacement therapy in chronic pancreatitis: systematic review and meta-analysis

    PubMed Central

    de la Iglesia-García, Daniel; Huang, Wei; Szatmary, Peter; Baston-Rey, Iria; Gonzalez-Lopez, Jaime; Prada-Ramallal, Guillermo; Mukherjee, Rajarshi; Nunes, Quentin M; Domínguez-Muñoz, J Enrique

    2017-01-01

    Objective The benefits of pancreatic enzyme replacement therapy (PERT) in chronic pancreatitis (CP) are inadequately defined. We have undertaken a systematic review and meta-analysis of randomised controlled trials of PERT to determine the efficacy of PERT in exocrine pancreatic insufficiency (EPI) from CP. Design Major databases were searched from 1966 to 2015 inclusive. The primary outcome was coefficient of fat absorption (CFA). Effects of PERT versus baseline and versus placebo, and of different doses, formulations and schedules were determined. Results A total of 17 studies (511 patients with CP) were included and assessed qualitatively (Jadad score). Quantitative data were synthesised from 14 studies. PERT improved CFA compared with baseline (83.7±6.0 vs 63.1±15.0, p<0.00001; I2=89%) and placebo (83.2±5.5 vs 67.4±7.0, p=0.0001; I2=86%). PERT improved coefficient of nitrogen absorption, reduced faecal fat excretion, faecal nitrogen excretion, faecal weight and abdominal pain, without significant adverse events. Follow-up studies demonstrated that PERT increased serum nutritional parameters, improved GI symptoms and quality of life without significant adverse events. High-dose or enteric-coated enzymes showed a trend to greater effectiveness than low-dose or non-coated comparisons, respectively. Subgroup, sensitive and meta-regression analyses revealed that sample size, CP diagnostic criteria, study design and enzyme dose contributed to heterogeneity; data on health inequalities were lacking. Conclusions PERT is indicated to correct EPI and malnutrition in CP and may be improved by higher doses, enteric coating, administration during food and acid suppression. Further studies are required to determine optimal regimens, the impact of health inequalities and long-term effects on nutrition. PMID:27941156

  14. Efficacy of pancreatic enzyme replacement therapy in chronic pancreatitis: systematic review and meta-analysis.

    PubMed

    de la Iglesia-García, Daniel; Huang, Wei; Szatmary, Peter; Baston-Rey, Iria; Gonzalez-Lopez, Jaime; Prada-Ramallal, Guillermo; Mukherjee, Rajarshi; Nunes, Quentin M; Domínguez-Muñoz, J Enrique; Sutton, Robert

    2017-08-01

    The benefits of pancreatic enzyme replacement therapy (PERT) in chronic pancreatitis (CP) are inadequately defined. We have undertaken a systematic review and meta-analysis of randomised controlled trials of PERT to determine the efficacy of PERT in exocrine pancreatic insufficiency (EPI) from CP. Major databases were searched from 1966 to 2015 inclusive. The primary outcome was coefficient of fat absorption (CFA). Effects of PERT versus baseline and versus placebo, and of different doses, formulations and schedules were determined. A total of 17 studies (511 patients with CP) were included and assessed qualitatively (Jadad score). Quantitative data were synthesised from 14 studies. PERT improved CFA compared with baseline (83.7±6.0 vs 63.1±15.0, p<0.00001; I 2 =89%) and placebo (83.2±5.5 vs 67.4±7.0, p=0.0001; I 2 =86%). PERT improved coefficient of nitrogen absorption, reduced faecal fat excretion, faecal nitrogen excretion, faecal weight and abdominal pain, without significant adverse events. Follow-up studies demonstrated that PERT increased serum nutritional parameters, improved GI symptoms and quality of life without significant adverse events. High-dose or enteric-coated enzymes showed a trend to greater effectiveness than low-dose or non-coated comparisons, respectively. Subgroup, sensitive and meta-regression analyses revealed that sample size, CP diagnostic criteria, study design and enzyme dose contributed to heterogeneity; data on health inequalities were lacking. PERT is indicated to correct EPI and malnutrition in CP and may be improved by higher doses, enteric coating, administration during food and acid suppression. Further studies are required to determine optimal regimens, the impact of health inequalities and long-term effects on nutrition. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  15. Cardiomyopathy and Response to Enzyme Replacement Therapy in a Male Mouse Model for Fabry Disease

    PubMed Central

    Nguyen Dinh Cat, Aurelie; Escoubet, Brigitte; Agrapart, Vincent; Griol-Charhbili, Violaine; Schoeb, Trenton; Feng, Wenguang; Jaimes, Edgar; Warnock, David G.; Jaisser, Frederic

    2012-01-01

    Fabry disease is an X-linked disorder of glycosphingolipid metabolism that results in progressive accumulation of neutral glycosphingolipids, (predominately globotriaosylceramide; GL-3) in lysosomes, as well as other cellular compartments and the extracellular space. Our aim was to characterize the cardiac phenotype of male knock-out mice that are deficient in alpha-galactosidase A activity, as a model for Fabry disease and test the efficacy of Enzyme Replacement Therapy with agalsidase-beta. Male mice (3–4 months of age) were characterized with awake blood pressure and heart rate measurements, cardiac echocardiography and electrocardiography measurements under light anesthesia, histological studies and molecular studies with real-time polymerase chain reaction. The Fabry knock-out mouse has bradycardia and lower blood pressure than control wild type (CB7BL/6J) mice. In Fabry knock-out mice, the cardiomyopathy associated mild hypertrophy at echography with normal systolic LV function and mild diastolic dysfunction. Premature atrial contractions were more frequent in without conduction defect. Heart weight normalized to tibial length was increased in Fabry knock-out mice. Ascending aorta dilatation was observed. Molecular studies were consistent with early stages of cardiac remodeling. A single dose of agalsidase-beta (3 mg/kg) did not affect the LV hypertrophy, function or heart rate, but did improve the mRNA signals of early cardiac remodeling. In conclusion, the alpha-galactosidase A deficient mice at 3 to 4 months of age have cardiac and vascular alterations similar to that described in early clinical stage of Fabry disease in children and adolescents. Enzyme replacement therapy affects cardiac molecular remodeling after a single dose. PMID:22574107

  16. Cardiomyopathy and response to enzyme replacement therapy in a male mouse model for Fabry disease.

    PubMed

    Nguyen Dinh Cat, Aurelie; Escoubet, Brigitte; Agrapart, Vincent; Griol-Charhbili, Violaine; Schoeb, Trenton; Feng, Wenguang; Jaimes, Edgar; Warnock, David G; Jaisser, Frederic

    2012-01-01

    Fabry disease is an X-linked disorder of glycosphingolipid metabolism that results in progressive accumulation of neutral glycosphingolipids, (predominately globotriaosylceramide; GL-3) in lysosomes, as well as other cellular compartments and the extracellular space. Our aim was to characterize the cardiac phenotype of male knock-out mice that are deficient in alpha-galactosidase A activity, as a model for Fabry disease and test the efficacy of Enzyme Replacement Therapy with agalsidase-beta. Male mice (3-4 months of age) were characterized with awake blood pressure and heart rate measurements, cardiac echocardiography and electrocardiography measurements under light anesthesia, histological studies and molecular studies with real-time polymerase chain reaction. The Fabry knock-out mouse has bradycardia and lower blood pressure than control wild type (CB7BL/6J) mice. In Fabry knock-out mice, the cardiomyopathy associated mild hypertrophy at echography with normal systolic LV function and mild diastolic dysfunction. Premature atrial contractions were more frequent in without conduction defect. Heart weight normalized to tibial length was increased in Fabry knock-out mice. Ascending aorta dilatation was observed. Molecular studies were consistent with early stages of cardiac remodeling. A single dose of agalsidase-beta (3 mg/kg) did not affect the LV hypertrophy, function or heart rate, but did improve the mRNA signals of early cardiac remodeling. In conclusion, the alpha-galactosidase A deficient mice at 3 to 4 months of age have cardiac and vascular alterations similar to that described in early clinical stage of Fabry disease in children and adolescents. Enzyme replacement therapy affects cardiac molecular remodeling after a single dose.

  17. Reduction of elevated plasma globotriaosylsphingosine in patients with classic Fabry disease following enzyme replacement therapy.

    PubMed

    van Breemen, Mariëlle J; Rombach, Saskia M; Dekker, Nick; Poorthuis, Ben J; Linthorst, Gabor E; Zwinderman, Aeilko H; Breunig, Frank; Wanner, Christoph; Aerts, Johannes M; Hollak, Carla E

    2011-01-01

    Fabry disease is treated by two-weekly infusions with α-galactosidase A, which is deficient in this X-linked globotriaosylceramide (Gb3) storage disorder. Elevated plasma globotriaosylsphingosine (lysoGb3) is a hallmark of classical Fabry disease. We investigated effects of enzyme replacement therapy (ERT) on plasma levels of lysoGb3 and Gb3 in patients with classical Fabry disease treated with agalsidase alfa at 0.2mg/kg, agalsidase beta at 0.2mg/kg or at 1.0mg/kg bodyweight. Each treatment regimen led to prominent reductions of plasma lysoGb3 in Fabry males within 3 months (P=0.0313), followed by relative stability later on. Many males developed antibodies against α-galactosidase A, particularly those treated with agalsidase beta. Patients with antibodies tended towards smaller correction in plasma lysoGb3 concentration, whereas treatment with high dose agalsidase beta allowed a reduction comparable to patients without antibodies. Pre-treatment plasma lysoGb3 concentrations of Fabry females were relatively low. In all females and with each treatment regimen, ERT gave reduction or stabilisation of plasma lysoGb3. Our investigation revealed that ERT of Fabry patients reduces plasma lysoGb3, regardless of the recombinant enzyme used. This finding shows that ERT can correct a characteristic biochemical abnormality in Fabry patients. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Enzyme replacement therapy for Fabry disease: some answers but more questions.

    PubMed

    Alfadhel, Majid; Sirrs, Sandra

    2011-01-01

    Fabry disease (FD) is a multisystem, X-linked disorder of glycosphingolipid metabolism caused by enzyme deficiency of α-galactosidase A. Affected patients have symptoms including acroparesthesias, angiokeratomas, and hypohidrosis. More serious manifestations include debilitating pain and gastrointestinal symptoms, proteinuria and gradual deterioration of renal function leading to end-stage renal disease, hypertrophic cardiomyopathy, and stroke. Heterozygous females may have symptoms as severe as males with the classic phenotype. Before 2001, treatment of patients with FD was supportive. The successful development of enzyme replacement therapy (ERT) has been a great advancement in the treatment of patients with FD and can stabilize renal function and cardiac size, as well as improve pain and quality of life of patients with FD. In this review, we have provided a critical appraisal of the literature on the effects of ERT for FD. This analysis shows that data available on the treatment of FD are often derived from studies which are not controlled, rely on surrogate markers, and are of insufficient power to detect differences on hard clinical endpoints. Further studies of higher quality are needed to answer the questions that remain concerning the efficacy of ERT for FD.

  19. Long Circulating Enzyme Replacement Therapy Rescues Bone Pathology in Mucopolysaccharidosis VII Murine Model

    PubMed Central

    Rowan, Daniel J.; Tomatsu, Shunji; Grubb, Jeffrey H.; Haupt, Bisong; Montaño, Adriana M.; Oikawa, Hirotaka; Sosa, Catalina; Chen, Anping; Sly, William S.

    2012-01-01

    Mucopolysaccharidosis (MPS) type VII is a lysosomal storage disease caused by deficiency of the lysosomal enzyme β-glucuronidase (GUS), leading to accumulation of glycosaminoglycans (GAGs). Enzyme replacement therapy (ERT) effectively clears GAG storage in the viscera. Recent studies showed that a chemically modified form of GUS (PerT-GUS), which escaped clearance by mannose 6-phosphate and mannose receptors and showed prolonged circulation, reduced CNS storage more effectively than native GUS. Clearance of storage in bone has been limited due to the avascularity of the growth plate. To evaluate the effectiveness of long-circulating PerT-GUS in reducing the skeletal pathology, we treated MPS VII mice for 12 weeks beginning at 5 weeks of age with PerT-GUS or native GUS and used micro-CT, radiographs, and quantitative histopathological analysis for assessment of bones. Micro-CT findings showed PerT-GUS treated mice had a significantly lower BMD. Histopathological analysis also showed reduced storage material and a more organized growth plate in PerT-GUS treated mice compared with native GUS treated mice. Long term treatment with PerT-GUS from birth up to 57 weeks also significantly improved bone lesions demonstrated by micro-CT, radiographs and quantitative histopathological assay. In conclusion, long-circulating PerT-GUS provides a significant impact to rescue of bone lesions and CNS involvement. PMID:22902520

  20. Rapid Immunochromatographic Detection of Serum Anti-α-Galactosidase A Antibodies in Fabry Patients after Enzyme Replacement Therapy

    PubMed Central

    Nakano, Sachie; Tsukimura, Takahiro; Togawa, Tadayasu; Ohashi, Toya; Kobayashi, Masahisa; Takayama, Katsuyoshi; Kobayashi, Yukuharu; Abiko, Hiroshi; Satou, Masatsugu; Nakahata, Tohru; Warnock, David G.; Sakuraba, Hitoshi; Shibasaki, Futoshi

    2015-01-01

    We developed an immunochromatography-based assay for detecting antibodies against recombinant α-galactosidase A proteins in serum. The evaluation of 29 serum samples from Fabry patients, who had received enzyme replacement therapy with agalsidase alpha and/or agalsidase beta, was performed by means of this assay method, and the results clearly revealed that the patients exhibited the same level of antibodies against both agalsidase alpha and agalsidase beta, regardless of the species of recombinant α-galactosidase A used for enzyme replacement therapy. A conventional enzyme-linked immunosorbent assay supported the results. Considering these, enzyme replacement therapy with agalsidase alpha or agalsidase beta would generate antibodies against the common epitopes in both agalsidase alpha and agalsidase beta. Most of the patients who showed immunopositive reaction exhibited classic Fabry phenotype and harbored gene mutations affecting biosynthesis of α-galactosidase A. As immunochromatography is a handy and simple assay system which can be available at bedside, this assay method would be extremely useful for quick evaluation or first screening of serum antibodies against agalsidase alpha or agalsidase beta in Fabry disease with enzyme replacement therapy. PMID:26083343

  1. Rapid Immunochromatographic Detection of Serum Anti-α-Galactosidase A Antibodies in Fabry Patients after Enzyme Replacement Therapy.

    PubMed

    Nakano, Sachie; Tsukimura, Takahiro; Togawa, Tadayasu; Ohashi, Toya; Kobayashi, Masahisa; Takayama, Katsuyoshi; Kobayashi, Yukuharu; Abiko, Hiroshi; Satou, Masatsugu; Nakahata, Tohru; Warnock, David G; Sakuraba, Hitoshi; Shibasaki, Futoshi

    2015-01-01

    We developed an immunochromatography-based assay for detecting antibodies against recombinant α-galactosidase A proteins in serum. The evaluation of 29 serum samples from Fabry patients, who had received enzyme replacement therapy with agalsidase alpha and/or agalsidase beta, was performed by means of this assay method, and the results clearly revealed that the patients exhibited the same level of antibodies against both agalsidase alpha and agalsidase beta, regardless of the species of recombinant α-galactosidase A used for enzyme replacement therapy. A conventional enzyme-linked immunosorbent assay supported the results. Considering these, enzyme replacement therapy with agalsidase alpha or agalsidase beta would generate antibodies against the common epitopes in both agalsidase alpha and agalsidase beta. Most of the patients who showed immunopositive reaction exhibited classic Fabry phenotype and harbored gene mutations affecting biosynthesis of α-galactosidase A. As immunochromatography is a handy and simple assay system which can be available at bedside, this assay method would be extremely useful for quick evaluation or first screening of serum antibodies against agalsidase alpha or agalsidase beta in Fabry disease with enzyme replacement therapy.

  2. Antibody-mediated enzyme replacement therapy targeting both lysosomal and cytoplasmic glycogen in Pompe disease.

    PubMed

    Yi, Haiqing; Sun, Tao; Armstrong, Dustin; Borneman, Scott; Yang, Chunyu; Austin, Stephanie; Kishnani, Priya S; Sun, Baodong

    2017-05-01

    Pompe disease is characterized by accumulation of both lysosomal and cytoplasmic glycogen primarily in skeletal and cardiac muscles. Mannose-6-phosphate receptor-mediated enzyme replacement therapy (ERT) with recombinant human acid α-glucosidase (rhGAA) targets the enzyme to lysosomes and thus is unable to digest cytoplasmic glycogen. Studies have shown that anti-DNA antibody 3E10 penetrates living cells and delivers "cargo" proteins to the cytosol or nucleus via equilibrative nucleoside transporter ENT2. We speculate that 3E10-mediated ERT with GAA will target both lysosomal and cytoplasmic glycogen in Pompe disease. A fusion protein (FabGAA) containing a humanized Fab fragment derived from the murine 3E10 antibody and the 110 kDa human GAA precursor was constructed and produced in CHO cells. Immunostaining with an anti-Fab antibody revealed that the Fab signals did not co-localize with the lysosomal marker LAMP2 in cultured L6 myoblasts or Pompe patient fibroblasts after incubation with FabGAA. Western blot with an anti-GAA antibody showed presence of the 150 kDa full-length FabGAA in the cell lysates, in addition to the 95- and 76 kDa processed forms of GAA that were also seen in the rhGAA-treated cells. Blocking of mannose-6-phosphate receptor with mannose-6-phosphate markedly reduced the 95- and the 76 kDa forms but not the 150 kDa form. In GAA-KO mice, FabGAA achieved similar treatment efficacy as rhGAA at an equal molar dose in reducing tissue glycogen contents. Our data suggest that FabGAA retains the ability of rhGAA to treat lysosomal glycogen accumulation and has the beneficial potential over rhGAA to reduce cytoplasmic glycogen storage in Pompe disease. FabGAA can be delivered to both the cytoplasm and lysosomes in cultured cells. FabGAA equally reduced lysosomal glycogen accumulation as rhGAA in GAA-KO mice. FabGAA has the beneficial potential over rhGAA to clear cytoplasmic glycogen. This study suggests a novel antibody-enzyme fusion protein therapy

  3. Stepwise-activable multifunctional peptide-guided prodrug micelles for cancerous cells intracellular drug release

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Li, Mengfei; Yuan, Zhefan; Wu, Dan; Chen, Jia-da; Feng, Jie

    2016-10-01

    A novel type of stepwise-activable multifunctional peptide-guided prodrug micelles (MPPM) was fabricated for cancerous cells intracellular drug release. Deca-lysine sequence (K10), a type of cell-penetrating peptide, was synthesized and terminated with azido-glycine. Then a new kind of molecule, alkyne modified doxorubicin (DOX) connecting through disulfide bond (DOX-SS-alkyne), was synthesized. After coupling via Cu-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry reaction, reduction-sensitive peptide-guided prodrug was obtained. Due to the amphiphilic property of the prodrug, it can assemble to form micelles. To prevent the nanocarriers from unspecific cellular uptake, the prodrug micelles were subsequently modified with 2,3-dimethyl maleic anhydride to obtain MPPM with a negatively charged outer shell. In vitro studies showed that MPPM could be shielded from cells under psychological environment. However, when arriving at mild acidic tumor site, the cell-penetrating capacity of MPPM would be activated by charge reversal of the micelles via hydrolysis of acid-labile β-carboxylic amides and regeneration of K10, which enabled efficient internalization of MPPM by tumor cells as well as following glutathione- and protease-induced drug release inside the cancerous cells. Furthermore, since the guide peptide sequences can be accurately designed and synthesized, it can be easily changed for various functions, such as targeting peptide, apoptotic peptide, even aptamers, only need to be terminated with azido-glycine. This method can be used as a template for reduction-sensitive peptide-guided prodrug for cancer therapy.

  4. Human glutathione transferases catalyzing the bioactivation of anticancer thiopurine prodrugs.

    PubMed

    Eklund, Birgitta I; Gunnarsdottir, Sjofn; Elfarra, Adnan A; Mannervik, Bengt

    2007-06-01

    cis-6-(2-Acetylvinylthio)purine (cAVTP) and trans-6-(2-acetylvinylthio)guanine (tAVTG) are thiopurine prodrugs provisionally inactivated by an alpha,beta-unsaturated substituent on the sulfur of the parental thiopurines 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG). The active thiopurines are liberated intracellularly by glutathione (GSH) in reactions catalyzed by glutathione transferases (GSTs) (EC 2.5.1.18). Catalytic activities of 13 human GSTs representing seven distinct classes of soluble GSTs have been determined. The bioactivation of cAVTP and tAVTG occurs via a transient addition of GSH to the activated double bond of the S-substituent of the prodrug, followed by elimination of the thiopurine. The first of these consecutive reactions is rate-limiting for thiopurine release, but GST-activation of this first addition is shifting the rate limitation to the subsequent elimination. Highly active GSTs reveal the transient intermediate, which is detectable by UV spectroscopy and HPLC analysis. LC/MS analysis of the reaction products demonstrates that the primary GSH conjugate, 4-glutathionylbuten-2-one, can react with a second GSH molecule to form the 4-(bis-glutathionyl)butan-2-one. GST M1-1 and GST A4-4 were the most efficient enzymes with tAVTG, and GST M1-1 and GST M2-2 had highest activity with cAVTP. The highly efficient GST M1-1 is polymorphic and is absent in approximately half of the human population. GST P1-1, which is overexpressed in many cancer cells, had no detectable activity with cAVTP and only minor activity with tAVTG. Other GST-activated prodrugs have targeted GST P1-1-expressing cancer cells. Tumors expressing high levels of GST M1-1 or GST A4-4 can be predicted to be particularly vulnerable to chemotherapy with cAVTP or tAVTG.

  5. Prodrugs for transdermal drug delivery - trends and challenges.

    PubMed

    Ita, Kevin B

    2016-09-01

    Prodrugs continue to attract significant interest in the transdermal drug delivery field. These moieties can confer favorable physicochemical properties on transdermal drug delivery candidates. Alkyl chain lengthening, pegylation are some of the strategies used for prodrug synthesis. It is usually important to optimize partition coefficient, water and oil solubilities of drugs. In this review, progress made in the field of prodrugs for percutaneous penetration is highlighted and the challenges discussed.

  6. Long-term safety and efficacy of enzyme replacement therapy for Fabry disease.

    PubMed

    Wilcox, William R; Banikazemi, Maryam; Guffon, Nathalie; Waldek, Stephen; Lee, Philip; Linthorst, Gabor E; Desnick, Robert J; Germain, Dominique P

    2004-07-01

    Elsewhere, we reported the safety and efficacy results of a multicenter phase 3 trial of recombinant human alpha -galactosidase A (rh-alpha GalA) replacement in patients with Fabry disease. All 58 patients who were enrolled in the 20-wk phase 3 double-blind, randomized, and placebo-controlled study received subsequently 1 mg/kg of rh-alpha GalA (agalsidase beta, Fabrazyme, Genzyme Corporation) biweekly in an ongoing open-label extension study. Evidence of long-term efficacy, even in patients who developed IgG antibodies against rh- alpha GalA, included the continuously normal mean plasma globotriaosylceramide (GL-3) levels during 30 mo of the extension study and the sustained capillary endothelial GL-3 clearance in 98% (39/40) of patients who had a skin biopsy taken after treatment for 30 mo (original placebo group) or 36 mo (original enzyme-treated group). The mean serum creatinine level and estimated glomerular filtration rate also remained stable after 30-36 mo of treatment. Infusion-associated reactions decreased over time, as did anti-rh- alpha GalA IgG antibody titers. Among seroconverted patients, after 30-36 mo of treatment, seven patients tolerized (no detectable IgG antibody), and 59% had > or =4-fold reductions in antibody titers. As of 30 mo into the extension trial, three patients were withdrawn from the study because of positive serum IgE or skin tests; however, all have been rechallenged successfully at the time of this report. Thus, enzyme replacement therapy for 30-36 mo with agalsidase beta resulted in continuously decreased plasma GL-3 levels, sustained endothelial GL-3 clearance, stable kidney function, and a favorable safety profile.

  7. Pancreatic Enzyme Replacement Therapy in Children with Severe Acute Malnutrition: A Randomized Controlled Trial.

    PubMed

    Bartels, Rosalie H; Bourdon, Céline; Potani, Isabel; Mhango, Brian; van den Brink, Deborah A; Mponda, John S; Muller Kobold, Anneke C; Bandsma, Robert H; Boele van Hensbroek, Michael; Voskuijl, Wieger P

    2017-11-01

    To assess the benefits of pancreatic enzyme replacement therapy (PERT) in children with complicated severe acute malnutrition. We conducted a randomized, controlled trial in 90 children aged 6-60 months with complicated severe acute malnutrition at the Queen Elizabeth Central Hospital in Malawi. All children received standard care; the intervention group also received PERT for 28 days. Children treated with PERT for 28 days did not gain more weight than controls (13.7 ± 9.0% in controls vs 15.3 ± 11.3% in PERT; P = .56). Exocrine pancreatic insufficiency was present in 83.1% of patients on admission and fecal elastase-1 levels increased during hospitalization mostly seen in children with nonedematous severe acute malnutrition (P <.01). Although the study was not powered to detect differences in mortality, mortality was significantly lower in the intervention group treated with pancreatic enzymes (18.6% vs 37.8%; P < .05). Children who died had low fecal fatty acid split ratios at admission. Exocrine pancreatic insufficiency was not improved by PERT, but children receiving PERT were more likely to be discharged with every passing day (P = .02) compared with controls. PERT does not improve weight gain in severely malnourished children but does increase the rate of hospital discharge. Mortality was lower in patients on PERT, a finding that needs to be investigated in a larger cohort with stratification for edematous and nonedematous malnutrition. Mortality in severe acute malnutrition is associated with markers of poor digestive function. ISRCTN.com: 57423639. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Enzyme replacement therapy with agalsidase beta improves cardiac involvement in Fabry's disease.

    PubMed

    Spinelli, L; Pisani, A; Sabbatini, M; Petretta, M; Andreucci, M V; Procaccini, D; Lo Surdo, N; Federico, S; Cianciaruso, B

    2004-08-01

    Fabry's disease is an X-linked lysosomal storage disease caused by a deficiency of alpha-galactosidase that results in an accumulation of neutral glycosphingolipids throughout the body, including the cardiovascular system. Fabry cardiomyopathy, characterized by progressive severe concentric left ventricular (LV) hypertrophy, is very frequent and is the most important cause of death in affected patients. Enzyme replacement therapy (ERT) allows a specific treatment for this disease, however, there are very few data on the effectiveness of therapy on cardiac involvement. Nine patients with Fabry cardiac disease were studied on basal condition and after 6 and 12 months of treatment with algasidase beta (Fabrazyme). A complete clinical, electrocardiographic and echocardiographic evaluation was performed in all patients. Interpretable Doppler recordings of transmitral flow and pulmonary flow velocity curves were also acquired. At baseline, the patients with Fabry's disease had increased LV septum and posterior wall thickness, normal LV fractional shortening, LV ejection fraction, normal Doppler parameters of mitral inflow but a duration of pulmonary vein flow velocity wave exceeding that of the mitral wave at atrial systole. ERT did not affect heart rate and arterial pressure. LV internal diameters did not change, there was a slight but not significant decrease in the LV posterior wall thickening and a progressive decrease in the interventricular septum thickening (p < 0.025) and in LV mass (p < 0.001) The difference in duration between pulmonary vein flow velocity wave and mitral wave at atrial systole significantly decreased (p < 0.001). These results suggest that ERT in patients with Fabry cardiomyopathy is able to reduce the LV mass and ameliorate the LV stiffness. Copyright 2004 Blackwell Munksgaard

  9. Enzyme-activatable imaging probe reveals enhanced neutrophil elastase activity in tumors following photodynamic therapy

    PubMed Central

    Modi, Kshitij D.; Foster, Thomas H.

    2013-01-01

    Abstract. We demonstrate the use of an enzyme-activatable fluorogenic probe, Neutrophil Elastase 680 FAST (NE680), for in vivo imaging of neutrophil elastase (NE) activity in tumors subjected to photodynamic therapy (PDT). NE protease activity was assayed in SCC VII and EMT6 tumors established in C3H and BALB/c mice, respectively. Four nanomoles of NE680 was injected intravenously immediately following PDT irradiation. 5 h following administration of NE680, whole-mouse fluorescence imaging was performed. At this time point, levels of NE680 fluorescence were at least threefold greater in irradiated versus unirradiated SCC VII and EMT6 tumors sensitized with Photofrin. To compare possible photosensitizer-specific differences in therapy-induced elastase activity, EMT6 tumors were also subjected to 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH)-PDT. NE levels measured in HPPH-PDT-treated tumors were twofold higher than in unirradiated controls. Ex vivo labeling of host cells using fluorophore-conjugated antibodies and confocal imaging were used to visualize Gr1+ cells in Photofrin-PDT-treated EMT6 tumors. These data were compared with recently reported analysis of Gr1+ cell accumulation in EMT6 tumors subjected to HPPH-PDT. The population density of infiltrating Gr1+ cells in treated versus unirradiated drug-only control tumors suggests that the differential in NE680 fold enhancement observed in Photofrin versus HPPH treatment may be attributed to the significantly increased inflammatory response induced by Photofrin-PDT. The in vivo imaging of NE680, which is a fluorescent reporter of NE extracellular release caused by neutrophil activation, demonstrates that PDT results in increased NE levels in treated tumors, and the accumulation of the cleaved probe tracks qualitatively with the intratumor Gr1+ cell population. PMID:23897439

  10. Dual-Porosity Hollow Nanoparticles for the Immunoprotection and Delivery of Nonhuman Enzymes

    PubMed Central

    2015-01-01

    Although enzymes of nonhuman origin have been studied for a variety of therapeutic and diagnostic applications, their use has been limited by the immune responses generated against them. The described dual-porosity hollow nanoparticle platform obviates immune attack on nonhuman enzymes paving the way to in vivo applications including enzyme-prodrug therapies and enzymatic depletion of tumor nutrients. This platform is manufactured with a versatile, scalable, and robust fabrication method. It efficiently encapsulates macromolecular cargos filled through mesopores into a hollow interior, shielding them from antibodies and proteases once the mesopores are sealed with nanoporous material. The nanoporous shell allows small molecule diffusion allowing interaction with the large macromolecular payload in the hollow center. The approach has been validated in vivo using l-asparaginase to achieve l-asparagine depletion in the presence of neutralizing antibodies. PMID:24471767

  11. Deleterious effects of interruption followed by reintroduction of enzyme replacement therapy on a lysosomal storage disorder.

    PubMed

    Schneider, Ana Paula; Matte, Ursula; Pasqualim, Gabriela; Tavares, Angela Maria Vicente; Mayer, Fabiana Quoos; Martinelli, Barbara; Ribas, Graziela; Vargas, Carmen Regla; Giugliani, Roberto; Baldo, Guilherme

    2016-10-01

    Temporary interruption of enzyme replacement therapy (ERT) in patients with different lysosomal storage disorders may happen for different reasons (adverse reactions, issues with reimbursement, logistic difficulties, and so forth), and the impact of the interruption is still uncertain. In the present work, we studied the effects of the interruption of intravenous ERT (Laronidase, Genzyme) followed by its reintroduction in mice with the prototypical lysosomal storage disorder mucopolysaccharidosis type I, comparing to mice receiving continuous treatment, untreated mucopolysaccharidosis type I mice, and normal mice. In the animals which treatment was temporarily interrupted, we observed clear benefits of treatment in several organs (liver, lung, heart, kidney, and testis) after reintroduction, but a worsening in the thickness of the aortic wall was detected. Furthermore, these mice had just partial improvements in behavioral tests, suggesting some deterioration in the brain function. Despite worsening is some disease aspects, urinary glycosaminoglycans levels did not increase during interruption, which indicates that this biomarker commonly used to monitor treatment in patients should not be used alone to assess treatment efficacy. The deterioration observed was not caused by the development of serum antienzyme antibodies. All together our results suggest that temporary ERT interruption leads to deterioration of function in some organs and should be avoided whenever possible. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Severe infusion reactions to fabry enzyme replacement therapy: rechallenge after tracheostomy.

    PubMed

    Nicholls, K; Bleasel, K; Becker, G

    2012-01-01

    A 34-year-old male patient with Fabry disease (OMIM 301500) commenced enzyme replacement therapy (ERT) with Agalsidase alfa, with positive clinical response. Infusion reactions, initially mild and easily managed, commenced during his 13th infusion, and continued over the next 3 years. Severity of reactions subsequently increased despite very slow infusion, extended prophylactic medication and attempted desensitisation, requiring regular intensive care unit (ICU) admissions. Facial oedema and flushing, throat tightness, headache and joint pain typically occurred 4-36 h after completion of most infusions, responding rapidly to subcutaneous adrenaline. Low titre specific IgG seroconversion was noted at 12 months, with subsequent reversion to negative after 5 years, despite persistence of infusion reactions. Specific IgE and skin testing was negative. Trial of ERT product switch to Agalsidase-beta resulted in no improvement in reactions. At 5 years, ERT was ceased in the face of recurrent ICU readmissions. In the face of progressive clinical deterioration, he underwent tracheostomy to allow recommencement of ERT. Two years later, he has clinically improved on regular attenuated dose Agalsidase-beta, administered by slow infusion in a local hospital setting.

  13. Enzyme Replacement Therapy Prevents Dental Defects in a Model of Hypophosphatasia

    PubMed Central

    McKee, M.D.; Nakano, Y.; Masica, D.L.; Gray, J.J.; Lemire, I.; Heft, R.; Whyte, M.P.; Crine, P.; Millán, J.L.

    2011-01-01

    Hypophosphatasia (HPP) occurs from loss-of-function mutation in the tissue-non-specific alkaline phosphatase (TNALP) gene, resulting in extracellular pyrophosphate accumulation that inhibits skeletal and dental mineralization. TNALP-null mice (Akp2-/-) phenocopy human infantile hypophosphatasia; they develop rickets at 1 week of age, and die before being weaned, having severe skeletal and dental hypomineralization and episodes of apnea and vitamin B6-responsive seizures. Delay and defects in dentin mineralization, together with a deficiency in acellular cementum, are characteristic. We report the prevention of these dental abnormalities in Akp2-/- mice receiving treatment from birth with daily injections of a mineral-targeting, human TNALP (sALP-FcD10). sALP-FcD10 prevented hypomineralization of alveolar bone, dentin, and cementum as assessed by micro-computed tomography and histology. Osteopontin – a marker of acellular cementum – was immuno-localized along root surfaces, confirming that acellular cementum, typically missing or reduced in Akp2-/- mice, formed normally. Our findings provide insight concerning how acellular cementum is formed on tooth surfaces to effect periodontal ligament attachment to retain teeth in their osseous alveolar sockets. Furthermore, they provide evidence that this enzyme-replacement therapy, applied early in post-natal life – where the majority of tooth root development occurs, including acellular cementum formation – could prevent the accelerated tooth loss seen in individuals with HPP. PMID:21212313

  14. Enzyme replacement therapy prevents dental defects in a model of hypophosphatasia.

    PubMed

    McKee, M D; Nakano, Y; Masica, D L; Gray, J J; Lemire, I; Heft, R; Whyte, M P; Crine, P; Millán, J L

    2011-04-01

    Hypophosphatasia (HPP) occurs from loss-of-function mutation in the tissue-non-specific alkaline phosphatase (TNALP) gene, resulting in extracellular pyrophosphate accumulation that inhibits skeletal and dental mineralization. TNALP-null mice (Akp2(-/-)) phenocopy human infantile hypophosphatasia; they develop rickets at 1 week of age, and die before being weaned, having severe skeletal and dental hypomineralization and episodes of apnea and vitamin B(6)-responsive seizures. Delay and defects in dentin mineralization, together with a deficiency in acellular cementum, are characteristic. We report the prevention of these dental abnormalities in Akp2(-/-) mice receiving treatment from birth with daily injections of a mineral-targeting, human TNALP (sALP-FcD(10)). sALP-FcD(10) prevented hypomineralization of alveolar bone, dentin, and cementum as assessed by micro-computed tomography and histology. Osteopontin--a marker of acellular cementum--was immuno-localized along root surfaces, confirming that acellular cementum, typically missing or reduced in Akp2(-/-) mice, formed normally. Our findings provide insight concerning how acellular cementum is formed on tooth surfaces to effect periodontal ligament attachment to retain teeth in their osseous alveolar sockets. Furthermore, they provide evidence that this enzyme-replacement therapy, applied early in post-natal life--where the majority of tooth root development occurs, including acellular cementum formation--could prevent the accelerated tooth loss seen in individuals with HPP.

  15. The Role of Pancreatic Enzyme Replacement Therapy in Unresectable Pancreatic Cancer: A Prospective Cohort Study.

    PubMed

    Saito, Tomotaka; Hirano, Kenji; Isayama, Hiroyuki; Nakai, Yousuke; Saito, Kei; Umefune, Gyotane; Akiyama, Dai; Watanabe, Takeo; Takagi, Kaoru; Hamada, Tsuyoshi; Takahara, Naminatsu; Uchino, Rie; Mizuno, Suguru; Kogure, Hirofumi; Matsubara, Saburo; Yamamoto, Natsuyo; Tada, Minoru; Koike, Kazuhiko

    2017-03-01

    Although patients with pancreatic cancer (PC) are prone to exocrine pancreatic insufficiency, there are little evidence about pancreatic enzyme replacement therapy (PERT) in patients with PC, especially those receiving chemotherapy. This is a prospective consecutive observational study of PERT in patients with unresectable PC. We prospectively enrolled patients receiving chemotherapy for unresectable PC from April 2012 to February 2014 and prescribed oral pancrelipase of 48,000 lipase units per meal (pancrelipase group). N-benzoyl-tryrosyl para-aminobenzoic acid test was performed at baseline. Patients receiving chemotherapy before April 2012 were retrospectively studied as a historical cohort. Data on the nutritional markers at baseline and 16 weeks were extracted, and serial changes, defined as the ratio of markers at 16 weeks/baseline, were compared between 2 groups. A total of 91 patients (46 in the pancrelipase group and 45 in the historical cohort) were analyzed. N-benzoyl-tryrosyl para-aminobenzoic acid test was low in 94% of the pancrelipase group. Serial change in the pancrelipase group versus historical cohort was 1.01 versus 0.95 in body mass index (P < 0.001) and 1.03 versus 0.97 in serum albumin (P = 0.131). The rate of exocrine pancreatic insufficiency in unresectable PC was high, and PERT can potentially improve the nutritional status during chemotherapy.

  16. Quantitative modeling of the dynamics and intracellular trafficking of far-red light-activatable prodrugs: implications in stimuli-responsive drug delivery system.

    PubMed

    Li, Mengjie; Thapa, Pritam; Rajaputra, Pallavi; Bio, Moses; Peer, Cody J; Figg, William D; You, Youngjae; Woo, Sukyung

    2017-12-01

    The combination of photodynamic therapy (PDT) with anti-tumor agents is a complimentary strategy to treat local cancers. We developed a unique photosensitizer (PS)-conjugated paclitaxel (PTX) prodrug in which a PS is excited by near-infrared wavelength light to site-specifically release PTX while generating singlet oxygen (SO) to effectively kill cancer cells with both PTX and SO. The aim of the present study was to identify the determinants influencing the combined efficacy of this light-activatable prodrug, especially the bystander killing effects from released PTX. Using PS-conjugated PTX as a model system, we developed a quantitative mathematical model describing the intracellular trafficking. Dynamics of the prodrug and the model predictions were verified with experimental data using human cancer cells in vitro. The sensitivity analysis suggested that parameters related to extracellular concentration of released PTX, prodrug uptake, target engagement, and target abundance are critical in determining the combined killing efficacy of the prodrug. We found that released PTX cytotoxicity was most sensitive to the retention time of the drug in extracellular space. Modulating drug internalization and conjugating the agents targeted to abundant receptors may provide a new strategy for maximizing the killing capacity of the far-red light-activatable prodrug system. These results provide guidance for the design of the PDT combination study in vivo and have implications for other stimuli-responsive drug delivery systems.

  17. Hepatic Enzyme Alterations in HIV Patients on Antiretroviral Therapy: A Case-Control Study in a Hospital Setting in Ghana.

    PubMed

    Osakunor, Derick Nii Mensah; Obirikorang, Christian; Fianu, Vincent; Asare, Isaac; Dakorah, Mavis

    2015-01-01

    Diagnosing hepatic injury in HIV infection can be a herculean task for clinicians as several factors may be involved. In this study, we sought to determine the effects of antiretroviral therapy (ART) and disease progression on hepatic enzymes in HIV patients. A case-control study conducted from January to May 2014 at the Akwatia Government Hospital, Eastern region, Ghana, The study included 209 HIV patients on ART (designated HIV-ART) and 132 ART-naive HIV patients (designated HIV-Controls). Data gathered included demography, clinical history and results of blood tests for hepatic enzymes. We employed the Fisher's, Chi-square, unpaired t-test and Pearson's correlation in analysis, using GraphPad Prism and SPSS. A P value < 0.05 was considered significant. Median CD4 lymphocyte count of HIV-ART participants (604.00 cells/mm3) was higher than that of HIV-Controls (491.50 cells/mm3; P = 0.0005). Mean values of ALP, ALT, AST and GGT did not differ between the two groups compared (P > 0.05). There was a significant positive correlation between hepatic enzymes (ALP, ALT, AST and GGT) for both groups (p < 0.01 each). Duration of ART correlated positively with ALT (p < 0.05). The effect size of disease progression on hepatic enzymes for both groups was small. Antiretroviral therapy amongst this population has minimal effects on hepatic enzymes and does not suggest modifications in therapy. Hepatic injury may occur in HIV, even in the absence of ART and other traditional factors. Monitoring of hepatic enzymes is still important in HIV patients.

  18. Far-Red Light Activatable, Multifunctional Prodrug for Fluorescence Optical Imaging and Combinational Treatment

    PubMed Central

    2015-01-01

    We recently developed “photo-unclick chemistry”, a novel chemical tool involving the cleavage of aminoacrylate by singlet oxygen, and demonstrated its application to visible light-activatable prodrugs. In this study, we prepared an advanced multifunctional prodrug, Pc-(L-CA4)2, composed of the fluorescent photosensitizer phthalocyanine (Pc), an SO-labile aminoacrylate linker (L), and a cytotoxic drug combretastatin A-4 (CA4). Pc-(L-CA4)2 had reduced dark toxicity compared with CA4. However, once illuminated, it showed improved toxicity similar to CA4 and displayed bystander effects in vitro. We monitored the time-dependent distribution of Pc-(L-CA4)2 using optical imaging with live mice. We also effectively ablated tumors by the illumination with far-red light to the mice, presumably through the combined effects of photodynamic therapy (PDT) and released chemotherapy drug, without any sign of acute systemic toxicity. PMID:24694092

  19. Enzyme replacement therapy in classical infantile pompe disease: results of a ten-month follow-up study.

    PubMed

    Klinge, L; Straub, V; Neudorf, U; Voit, T

    2005-02-01

    Infantile Pompe disease (IPD) is a fatal, autosomal recessive muscle-wasting disorder. Due to a deficiency of the lysosomal enzyme acid alpha-glucosidase patients develop a generalized myopathy, diaphragmatic weakness, and cardiomyopathy leading to death usually within the first year of life. So far there is no therapy available. We report on the safety and efficacy of transgenically derived recombinant human precursor acid alpha-glucosidase (rhGAA) in a 10-month follow-up study in two children with IPD who previously completed a 48-week course of enzyme replacement therapy (ERT) with the same medication at the same dose in a phase II clinical trial. Under this therapy cardiac status and muscle strength had improved, leading to survival beyond the age of one year. These results, together with data from two other phase II clinical trials encouraged further evaluation of the long-term safety and efficacy of enzyme replacement therapy in patients with infantile-onset Pompe disease. During the 10-month follow-up period, ERT was well-tolerated and neither patient experienced a single infusion-associated reaction. The initial improvements in cardiac size and function, as measured by left ventricular mass index and the fractional shortening, were maintained in both patients, and a continued improvement of motor function, as measured by the Alberta infant motor scale, was observed.

  20. Respiratory muscle training with enzyme replacement therapy improves muscle strength in late - onset Pompe disease.

    PubMed

    Jevnikar, Mitja; Kodric, Metka; Cantarutti, Fabiana; Cifaldi, Rossella; Longo, Cinzia; Della Porta, Rossana; Bembi, Bruno; Confalonieri, Marco

    2015-12-01

    Pompe disease is an autosomal recessive metabolic disorder caused by the deficiency of the lysosomal enzyme acid α-glucosidase. This deficiency leads to glycogen accumulation in the lysosomes of muscle tissue causing progressive muscular weakness particularly of the respiratory system. Enzyme replacement therapy (ERT) has demonstrated efficacy in slowing down disease progression in infants. Despite the large number of studies describing the effects of physical training in juvenile and adult late onset Pompe disease (LOPD). There are very few reports that analyze the benefits of respiratory muscle rehabilitation or training. The effectiveness of respiratory muscle training was investigated using a specific appliance with adjustable resistance (Threshold). The primary endpoint was effect on respiratory muscular strength by measurements of MIP and MEP. Eight late-onset Pompe patients (aged 13 to 58 years; 4 female, 4 male) with respiratory muscle deficiency on functional respiratory tests were studied. All patients received ERT at the dosage of 20 mg/kg/every 2 weeks and underwent training with Threshold at specified pressures for 24 months. A significant increase in MIP was observed during the follow-up of 24 month: 39.6 cm H 2 O (+ 25.0%) at month 3; 39.5 cm H 2 O (+ 24.9%) at month 6; 39.1 cm H 2 O (+ 23.7%) at month 9; 37.3 cm H 2 O (+ 18.2%) at month 12; and 37.3 cm H 2 O (+ 17.8%) at month 24. Median MEP values also showed a significant increase during the first 9 months: 29.8 cm H 2 O, (+ 14.3%) at month 3; 31.0 cm H 2 O (+ 18.6) at month 6; and 29.5 cm H 2 O (+ 12.9) at month 9. MEP was then shown to be decreased at months 12 and 24; median MEP was 27.2 cm H 2 O (+ 4.3%) at 12 months and 26.6 cm H 2 O (+ 1.9%) at 24 months. The FVC remain stable throughout the study. An increase in respiratory muscular strength was demonstrated with Threshold training when used in combination with ERT.

  1. COMPARING THE ENZYME REPLACEMENT THERAPY COST IN POST PANCREATECTOMY PATIENTS DUE TO PANCREATIC TUMOR AND CHRONIC PANCREATITIS.

    PubMed

    Fragoso, Anna Victoria; Pedroso, Martha Regina; Herman, Paulo; Montagnini, André Luis

    2016-01-01

    Among late postoperative complications of pancreatectomy are the exocrine and endocrine pancreatic insufficiencies. The presence of exocrine pancreatic insufficiency imposes, as standard treatment, pancreatic enzyme replacement. Patients with chronic pancreatitis, with intractable pain or any complications with surgical treatment, are likely to present exocrine pancreatic insufficiency or have this condition worsened requiring adequate dose of pancreatic enzymes. The aim of this study is to compare the required dose of pancreatic enzyme and the enzyme replacement cost in post pancreatectomy patients with and without chronic pancreatitis. Observational cross-sectional study. In the first half of 2015 patients treated at the clinic of the Department of Gastrointestinal Surgery at Hospital das Clínicas, Universidade de São Paulo, Brazil, who underwent pancreatectomy for at least 6 months and in use of enzyme replacement therapy were included in this series. The study was approved by the Research Ethics Committee. The patients were divided into two groups according to the presence or absence of chronic pancreatitis prior to pancreatic surgery. For this study, P<0.05 was considered statistically significant. The annual cost of the treatment was R$ 2150.5 ± 729.39; R$ 2118.18 ± 731.02 in patients without pancreatitis and R$ 2217.74 ± 736.30 in patients with pancreatitis. There was no statistically significant difference in the cost of treatment of enzyme replacement post pancreatectomy in patients with or without chronic pancreatitis prior to surgical indication.

  2. Dual delivery systems based on polyamine analog BENSpm as prodrug and gene delivery vectors

    NASA Astrophysics Data System (ADS)

    Zhu, Yu

    Combination drug and gene therapy shows promise in cancer treatment. However, the success of such strategy requires careful selection of the therapeutic agents, as well as development of efficient delivery vectors. BENSpm (N 1, N11-bisethylnorspermine), a polyamine analogue targeting the intracellular polyamine pathway, draws our special attention because of the following reasons: (1) polyamine pathway is frequently dysregulated in cancer; (2) BENSpm exhibits multiple functions to interfere with the polyamine pathway, such as to up-regulate polyamine metabolism enzymes and down-regulate polyamine biosynthesis enzymes. Therefore BENSpm depletes all natural polyamines and leads to apoptosis and cell growth inhibition in a wide range of cancers; (3) preclinical studies proved that BENSpm can act synergistically with various chemotherapy agents, making it a promising candidate in combination therapy; (4) multiple positive charges in BENSpm enable it as a suitable building block for cationic polymers, which can be further applied to gene delivery. In this dissertation, our goal was to design dual-function delivery vector based on BENSpm that can function as a gene delivery vector and, after intracellular degradation, as an active anticancer agent targeting dysregulated polyamine metabolism. We first demonstrated strong synergism between BENSpm and a potential therapeutic gene product TRAIL. Strong synergism was obtained in both estrogen-dependent MCF-7 breast cancer cells and triple-negative MDA-MB-231 breast cancer cells. Significant dose reduction of TRAIL in combination with BENSpm in MDA-MB-231 cells, together with the fact that BENSpm rendered MCF-7 cells more sensitive to TRAIL treatment verified our rationale of designing BENSpm-based delivery platform. This was expected to be beneficial for overcoming drug resistance in chemotherapy, as well as boosting the therapeutic effect of therapeutic genes. We first designed a lipid-based BENSpm dual vector (Lipo

  3. Relationship of Mitochondrial Enzymes to Fatigue Intensity in Men With Prostate Cancer Receiving External Beam Radiation Therapy

    PubMed Central

    Filler, Kristin; Lyon, Debra; McCain, Nancy; Bennett, James; Fernández-Martínez, Juan Luis; deAndrés-Galiana, Enrique Juan; Elswick, R. K.; Lukkahatai, Nada; Saligan, Leorey

    2015-01-01

    Purpose: Mitochondrial dysfunction is a plausible biological mechanism for cancer-related fatigue. Specific aims of this study were to (1) describe the levels of mitochondrial oxidative phosphorylation complex (MOPC) enzymes, fatigue, and health-related quality of life (HRQOL) before and at completion of external beam radiation therapy (EBRT) in men with nonmetastatic prostate cancer (PC); (2) examine relationships over time among levels of MOPC enzymes, fatigue, and HRQOL; and (3) compare levels of MOPC enzymes in men with clinically significant and nonsignificant fatigue intensification during EBRT. Methods: Fatigue was measured by the revised Piper Fatigue Scale and the Functional Assessment of Cancer Therapy–Fatigue subscale (FACT-F). MOPC enzymes (Complexes I–V) and mitochondrial antioxidant superoxide dismutase 2 were measured in peripheral blood using enzyme-linked immunosorbent assay at baseline and completion of EBRT. Participants were categorized into high or low fatigue (HF vs. LF) intensification groups based on amount of change in FACT-F scores during EBRT. Results: Fatigue reported by the 22 participants with PC significantly worsened and HRQOL significantly declined from baseline to EBRT completion. The HF group comprised 12 men with clinically significant change in fatigue (HF) during EBRT. Although no significant changes were observed in MOPC enzymes from baseline to EBRT completion, there were important differences in the patterns in the levels of MOPC enzymes between HF and LF groups. Conclusion: Distinct patterns of changes in the absorbance of MOPC enzymes delineated fatigue intensification among participants. Further investigation using a larger sample is warranted. PMID:26584846

  4. Light-emitting diode therapy reduces persistent inflammatory pain: Role of interleukin 10 and antioxidant enzymes.

    PubMed

    Martins, D F; Turnes, B L; Cidral-Filho, F J; Bobinski, F; Rosas, R F; Danielski, L G; Petronilho, F; Santos, A R S

    2016-06-02

    During the last decades, the use of light-emitting diode therapy (LEDT) has increased significantly for the treatment of wound healing, analgesia and inflammatory processes. Nevertheless, scientific data on the mechanisms responsible for the therapeutic effect of LEDT are still insufficient. Thus, this study investigated the analgesic, anti-inflammatory and anti-oxidative effect of LEDT in the model of chronic inflammatory hyperalgesia. Mice injected with Complete Freund's Adjuvant (CFA) underwent behavioral, i.e. mechanical and hot hyperalgesia; determination of cytokine levels (tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL-10), oxidative stress markers (protein carbonyls and thiobarbituric acid reactive species (TBARS)) and antioxidant enzymes (catalase (CAT) and superoxide dismutase (SOD)). Additionally, mice were pretreated with either naloxone or fucoidin and mechanical hyperalgesia was assessed. LEDT inhibited mechanical and thermal hyperalgesia induced by CFA injection. LEDT did not reduce paw edema, neither influenced the levels of TNF-α and IL1-β; although it increased the levels of IL-10. LEDT significantly prevented TBARS increase in both acute and chronic phases post-CFA injection; whereas protein carbonyl levels were reduced only in the acute phase. LEDT induced an increase in both SOD and CAT activity, with effects observable in the acute but not in the chronic. And finally, pre-administration of naloxone or fucoidin prevented LEDT analgesic effect. These data contribute to the understanding of the neurobiological mechanisms involved in the therapeutic effect of LEDT as well as provides additional support for its use in the treatment of painful conditions of inflammatory etiology. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Clinical benefit in Fabry patients given enzyme replacement therapy--a case series.

    PubMed

    Guffon, N; Fouilhoux, A

    2004-01-01

    Fabry disease is a rare lysosomal storage disorder resulting from deficient activity of alpha-galactosidase A and subsequent pathological accumulation of glycosphingolipids throughout the body. Traditionally, Fabry disease was managed symptomatically, but the introduction of enzyme replacement therapies (ERTs) (agalsidase beta (Fabrazyme); agalsidase alfa (Replagal)) has transformed treatment of this disorder. Clinical studies of both compounds have demonstrated clearance of glycosphingolipds from key tissues. To explore whether substrate clearance translates into clinical benefit, a retrospective survey of 17 patients (mean age 34.7 years) treated with agalsidase beta (1 mg/kg every 2 weeks) was undertaken, using an eight-item retrospective questionnaire developed specifically to assess the effect of ERT on the symptoms of Fabry disease. Pain severity, heat tolerance, physical activity, fatigue and psychological status were scored using a 10-point visual analogue scale (e.g. for pain severity: 1=none, 10=strong). Answers to all other questions were quantitative. Changes in mean scores were 4.69 to 2.25 (p =0.012) for pain severity; 4.38 to 2.21 (p =0.019) for number of pain crises per month; 8.69 to 2.98 (p =0.097) for duration of pain crises in hours; 2.76 to 5.76 (p =0.002) for heat tolerance; 3.28 to 2.51 (p =0.058) for bowel movements per day; 2.47 to 4.47 (p =0.007) for frequency of physical activity; 5.53 to 3.71 (p =0.046) for fatigue, and 5.82 to 8.12 (p =0.005) for psychological status. All patients improved in at least one aspect, although the degree of improvement across patients and aspects varied widely; reasons for this remain unclear. Despite the inherent bias involved in retrospective questionnaires, we believe that the findings are encouraging. A prospective version of the questionnaire is currently under validation.

  6. Enzyme replacement therapy in Japanese Fabry disease patients: the results of a phase 2 bridging study.

    PubMed

    Eto, Y; Ohashi, T; Utsunomiya, Y; Fujiwara, M; Mizuno, A; Inui, K; Sakai, N; Kitagawa, T; Suzuki, Y; Mochizuki, S; Kawakami, M; Hosoya, T; Owada, M; Sakuraba, H; Saito, H

    2005-01-01

    Fabry Disease (alpha-galactosidase A deficiency) is an X-linked hereditary disorder leading to the pathological accumulation of globotriaosylceramide (GL-3) in lysosomes, particularly in the vascular endothelium of the kidney, heart and brain. We report the results of an open-label phase 2 study that was undertaken to evaluate whether ethnic differences exist that would affect agalsidase beta (Fabrazyme) treatment of Fabry patients in the Japanese population, relative to safety and efficacy. The study design mirrored the design of the completed phase 3 clinical trial that led to approval of the product agalsidase beta. The 13 Japanese, male Fabry patients enrolled in the study received the enzyme replacement therapy over a period of 20 weeks as biweekly infusions. All selected efficacy end points showed improvements that were comparable with findings from the phase 3 study. These improvements included reductions of GL-3 accumulation in both kidney and skin capillary endothelial cells to (near) normal levels (92% of patients). Kidney and plasma GL-3 levels decreased by 51.9% and 100%, respectively, by ELISA. Renal function remained normal. Fabry-associated pain, and quality of life, showed improvement over baseline in multiple categories. Related adverse events were mild or moderate in intensity and mostly infusion-associated (fever and rigors). As expected, IgG antibody formation was observed in 85% of the patients, but had no effect on treatment response. These results suggest that treatment with agalsidase beta is safe and effective in Japanese patients with Fabry disease. With regard to safety and efficacy, no differences were observed as compared to the caucasian population.

  7. Enzyme replacement therapy with agalsidase beta in kidney transplant patients with Fabry disease: a pilot study.

    PubMed

    Mignani, Renzo; Panichi, Vincenzo; Giudicissi, Antonio; Taccola, Daniele; Boscaro, Francesca; Feletti, Carlo; Moneti, Gloriano; Cagnoli, Leonardo

    2004-04-01

    We sought to assess the safety and efficacy of enzyme replacement therapy (ERT) with recombinant human-alpha-galactosidase A (rh-alpha-Gal A) in kidney transplant recipients with Fabry disease, a previously unstudied population. Three male kidney transplant recipients with biochemically, genetically, and histologically confirmed Fabry disease and documented Fabry myocardiopathy received the rh-alpha-Gal A, agalsidase beta, 1 mg/kg of body weight every 2 weeks by intravenous infusion and were monitored biochemically, clinically, and electrocardiographically and echocardiographically for 18 months. Patients showed biochemical, clinical/functional, and morphologic response to ERT. Plasma globotriaosylceramide decreased 23% to 50%. Extremity pain resolved within 2 months in the patient with this manifestation. On echocardiography, left ventricular mass, end diastolic diameter (EDD), and cardiac contractility, shown by ejection fraction (EF), improved in 2 of the 3 patients receiving essentially all planned infusions. EDD and EF remained basically stable, but cardiac morphologic abnormalities progressed in the other patient, who had a 5-month interruption in ERT after the initial month. Mild mitral insufficiency persisted in all patients, as did atrial fibrillation in the affected individual. After a combined total of 116 infusions, no treatment-related adverse event, intolerance, or seroconversion was seen. Renal function remained stable and the immunosuppression regimen unchanged in all patients. Our pilot study provides preliminary evidence that ERT with agalsidase beta, 1 mg/kg every 2 weeks, is safe and often effective against extra-renal manifestations in kidney transplant patients with Fabry disease. Studies with longer courses of this and higher doses of ERT are merited in this population.

  8. Ocular lesions in canine mucopolysaccharidosis I and response to enzyme replacement therapy.

    PubMed

    Newkirk, Kim M; Atkins, Rosalie M; Dickson, Patti I; Rohrbach, Barton W; McEntee, Michael F

    2011-07-11

    Mucopolysaccharidosis I (MPS I) is an inherited metabolic disorder resulting from deficiency of α-L-iduronidase and lysosomal accumulation of glycosaminoglycans (GAG) in multiple tissues. Accumulation of GAG in corneal stromal cells causes corneal opacity and reduced vision. The purpose of this study was to determine the extent of ocular GAG accumulation and investigate the effectiveness of intravenous enzyme replacement therapy (ERT) on corneal GAG accumulation in dogs. Ocular tissues were obtained from 58 dogs with mucopolysaccharidosis I and four unaffected controls. Affected dogs received either low-dose ERT, high-dose ERT, or no treatment; some low-dose dogs also received intrathecal treatments. Histologic severity of corneal stromal GAG accumulation was scored. Accumulation of GAG was found in corneal stromal cells and scleral fibroblasts but not in corneal epithelium, endothelium, ciliary epithelium, choroid, retina, retinal pigment epithelium, or optic nerve. Corneal GAG accumulation increased in severity with increasing age. Although low-dose ERT did not significantly reduce corneal stromal GAG accumulation in comparison with untreated animals, high-dose ERT did result in significantly less GAG accumulation compared with the untreated dogs (adjusted P = 0.0143) or the low-dose ERT group (adjusted P = 0.0031). Intrathecal treatments did not significantly affect GAG accumulation. Dogs that began ERT shortly after birth also had significantly less (P < 0.0001) GAG accumulation in the corneal stroma than dogs with a later onset of treatment. These data suggest that high-dose, intravenous ERT is effective at preventing and/or clearing corneal stromal GAG accumulation, particularly if initiated early after birth.

  9. Pregnancy is associated with elevation of liver enzymes in HIV-positive women on antiretroviral therapy.

    PubMed

    Huntington, Susie; Thorne, Claire; Newell, Marie-Louise; Anderson, Jane; Taylor, Graham P; Pillay, Deenan; Hill, Teresa; Tookey, Pat A; Sabin, Caroline

    2015-04-24

    The objective of this study is to assess whether pregnancy is associated with an increased risk of liver enzyme elevation (LEE) and severe LEE in HIV-positive women on antiretroviral therapy (ART). Two observational studies: the UK Collaborative HIV Cohort (UK CHIC) study and the UK and Ireland National Study of HIV in Pregnancy and Childhood (NSHPC). Combined data from UK CHIC and NSHPC were used to identify factors associated with LEE (grade 1-4) and severe LEE (grade 3-4). Women starting ART in 2000-2012 were included irrespective of pregnancy status. Cox proportional hazards were used to assess fixed and time-dependent covariates including pregnancy status, CD4 cell count, drug regimen and hepatitis B virus/hepatitis C virus (HBV/HCV) coinfection. One-quarter (25.7%, 982/3815) of women were pregnant during follow-up, 14.2% (n = 541) when starting ART. The rate of LEE was 14.5/100 person-years in and 6.0/100 person-years outside of pregnancy. The rate of severe LEE was 3.9/100 person-years in and 0.6/100 person-years outside of pregnancy. The risk of LEE and severe LEE was increased during pregnancy [LEE: adjusted hazard ratio (aHR) 1.66 (1.31-2.09); severe LEE: aHR 3.57 (2.30-5.54)], including in secondary analyses excluding 541 women pregnant when starting ART. Other factors associated with LEE and severe LEE included lower CD4 cell count (<250 cells/μl), HBV/HCV coinfection and calendar year. Although few women developed severe LEE, this study provides further evidence that pregnancy is associated with an increased risk of LEE and severe LEE, reinforcing the need for regular monitoring of liver biomarkers during pregnancy.

  10. Development of Targeted, Enzyme-Activated Nano-Conjugates for Hepatic Cancer Therapy

    NASA Astrophysics Data System (ADS)

    Kuruvilla, Sibu Philip

    Hepatocellular carcinoma (HCC) is the 5th most commonly-occurring cancer worldwide and the 2nd highest cause for cancer-related deaths globally. The current treatment strategy is the direct injection of a chemotherapeutic agent (e.g. doxorubicin; DOX) into the hepatic artery, through a process called hepatic arterial infusion (HAI). Unfortunately, HAI is severely hindered by limited therapeutic efficacy against the tumor and high systemic toxicity to surrounding organs (e.g. cardiotoxicity). This thesis focuses on the development of a targeted, nanoparticle-based drug delivery system aimed to improve the clinical treatment of HCC. In particular, we employ generation 5 (G5) poly(amido amine) (PAMAM) dendrimers targeted to hepatic cancer cells via N-acetylgalactosamine (NAcGal) ligands attached to the surface through a poly(ethylene glycol) (PEG) brush. DOX is attached to the G5 surface through two different enzyme-sensitive linkages, L3 or L4, to achieve controllable release of the drug inside hepatic cancer cells. The combination of NAcGal-PEG targeting branches with either L3- or L4-DOX linkages led to the development of P1 and P2 particles, respectively. In Part 1, we discuss the development of these particles and measure their ability to target and kill hepatic cancer cells in vitro. In Part 2, we investigate the antitumor activity of P1 and P2 particles in tumor-bearing mice in comparison to the free drug, and we measure the cardiac function of mice undergoing treatment to assess differences in DOX-induced cardiotoxicity. Finally, in Part 3, we explore multi-valent targeting of G5 dendrimers in pursuit of further improving their specificity to hepatic cancer cells. Ultimately, this thesis provides insight into the utility of nanoparticle-based drug delivery systems that can potentially be translated to the clinic to improve cancer therapy.

  11. AAV Gene Therapy for Alcoholism: Inhibition of Mitochondrial Aldehyde Dehydrogenase Enzyme Expression in Hepatoma Cells.

    PubMed

    Sanchez, Anamaria C; Li, Chengwen; Andrews, Barbara; Asenjo, Juan A; Samulski, R Jude

    2017-09-01

    Most ethanol is broken down in the liver in two steps by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH2) enzymes, which metabolize down ethanol into acetaldehyde and then acetate. Some individuals from the Asian population who carry a mutation in the aldehyde dehydrogenase gene (ALDH2*2) cannot metabolize acetaldehyde as efficiently, producing strong effects, including facial flushing, dizziness, hypotension, and palpitations. This results in an aversion to alcohol intake and protection against alcoholism. The large prevalence of this mutation in the human population strongly suggests that modulation of ALDH2 expression by genetic technologies could result in a similar phenotype. scAAV2 vectors encoding ALDH2 small hairpin RNA (shRNA) were utilized to validate this hypothesis by silencing ALDH2 gene expression in human cell lines. Human cell lines HEK-293 and HepG2 were transduced with scAAV2/shRNA, showing a reduction in ALDH2 RNA and protein expression with the two viral concentration assayed (1 × 10 4 and 1 × 10 5 vg/cell) at two different time points. In both cell lines, ALDH2 RNA levels were reduced by 90% and protein expression was inhibited by 90% and 52%, respectively, 5 days post infection. Transduced HepG2 VL17A cells (ADH+) exposed to ethanol resulted in a 50% increase in acetaldehyde levels. These results suggest that gene therapy could be a useful tool for the treatment of alcoholism by knocking down ALDH2 expression using shRNA technology delivered by AAV vectors.

  12. Enzyme therapy in Fabry disease: severe adverse events associated with anti-agalsidase cross-reactive IgG antibodies.

    PubMed

    Tesmoingt, Chloe; Lidove, Olivier; Reberga, Axele; Thetis, Marguerite; Ackaert, Chloe; Nicaise, Pascale; Arnaud, Philippe; Papo, Thomas

    2009-11-01

    To report a severe adverse event related to enzyme replacement therapy with agalsidase in an hemizygous male patient treated for Fabry disease. Retrospective analysis of clinical, radiological and biochemical data in a patient who suffered adverse events related to both agalsidase alfa and agalsidase beta treatments. A hemizygous male patient was first treated for Fabry disease with agalsidase alfa. After more than 1 year of therapy, infusion-related symptoms necessitated systemic steroids and antihistaminic therapy. Decline in kidney function prompted a switch for agalsidase beta. Anaphylactoid shock occurred after the second infusion. No serum IgE antibodies were disclosed. Skin-test reactivity to agalsidase beta was negative. Following a published rechallenge infusion protocol, agalsidase beta was reintroduced, leading to a second anaphylactoid shock episode. Enzyme replacement therapy was stopped and the patient was treated with symptomatic therapy only. This case was referred to the pharmacovigilance department. The negativity of immunological tests (specific anti-agalsidase IgE antibodies and skin tests) does not rule out the risk of repeated anaphylactoid shock following agalsidase infusion.

  13. Enzyme therapy in Fabry disease: severe adverse events associated with anti-agalsidase cross-reactive IgG antibodies

    PubMed Central

    Tesmoingt, Chloe; Lidove, Olivier; Reberga, Axele; Thetis, Marguerite; Ackaert, Chloe; Nicaise, Pascale; Arnaud, Philippe; Papo, Thomas

    2009-01-01

    AIMS To report a severe adverse event related to enzyme replacement therapy with agalsidase in an hemizygous male patient treated for Fabry disease. METHODS Retrospective analysis of clinical, radiological and biochemical data in a patient who suffered adverse events related to both agalsidase alfa and agalsidase beta treatments. RESULTS A hemizygous male patient was first treated for Fabry disease with agalsidase alfa. After more than 1 year of therapy, infusion-related symptoms necessitated systemic steroids and antihistaminic therapy. Decline in kidney function prompted a switch for agalsidase beta. Anaphylactoid shock occurred after the second infusion. No serum IgE antibodies were disclosed. Skin-test reactivity to agalsidase beta was negative. Following a published rechallenge infusion protocol, agalsidase beta was reintroduced, leading to a second anaphylactoid shock episode. Enzyme replacement therapy was stopped and the patient was treated with symptomatic therapy only. This case was referred to the pharmacovigilance department. CONCLUSION The negativity of immunological tests (specific anti-agalsidase IgE antibodies and skin tests) does not rule out the risk of repeated anaphylactoid shock following agalsidase infusion. PMID:19917001

  14. Retrospective study of long-term outcomes of enzyme replacement therapy in Fabry disease: Analysis of prognostic factors

    PubMed Central

    Biegstraaten, Marieke; Hughes, Derralynn A.; Mehta, Atul; Elliott, Perry M.; Oder, Daniel; Watkinson, Oliver T.; Vaz, Frédéric M.; van Kuilenburg, André B. P.; Wanner, Christoph; Hollak, Carla E. M.

    2017-01-01

    Despite enzyme replacement therapy, disease progression is observed in patients with Fabry disease. Identification of factors that predict disease progression is needed to refine guidelines on initiation and cessation of enzyme replacement therapy. To study the association of potential biochemical and clinical prognostic factors with the disease course (clinical events, progression of cardiac and renal disease) we retrospectively evaluated 293 treated patients from three international centers of excellence. As expected, age, sex and phenotype were important predictors of event rate. Clinical events before enzyme replacement therapy, cardiac mass and eGFR at baseline predicted an increased event rate. eGFR was the most important predictor: hazard ratios increased from 2 at eGFR <90 ml/min/1.73m2 to 4 at eGFR <30, compared to patients with an eGFR >90. In addition, men with classical disease and a baseline eGFR <60 ml/min/1.73m2 had a faster yearly decline (-2.0 ml/min/1.73m2) than those with a baseline eGFR of >60. Proteinuria was a further independent risk factor for decline in eGFR. Increased cardiac mass at baseline was associated with the most robust decrease in cardiac mass during treatment, while presence of cardiac fibrosis predicted a stronger increase in cardiac mass (3.36 gram/m2/year). Of other cardiovascular risk factors, hypertension significantly predicted the risk for clinical events. In conclusion, besides increasing age, male sex and classical phenotype, faster disease progression while on enzyme replacement therapy is predicted by renal function, proteinuria and to a lesser extent cardiac fibrosis and hypertension. PMID:28763515

  15. Enzyme replacement therapy for Fabry disease: lessons from two alpha-galactosidase A orphan products and one FDA approval.

    PubMed

    Desnick, Robert J

    2004-07-01

    Two virtually identical products have been developed for enzyme replacement therapy for the treatment of Fabry disease, which is a rare and debilitating genetic disease caused by decreased activity of the lysosomal enzyme alpha-galactosidase A. Lack of this enzyme results in progressive tissue accumulation of globotriaosylceramide (GL-3), resulting in life-threatening renal, cardiac and cerebrovascular complications. Both enzyme replacement products, agalsidase alfa (Replagal; Transkaryotic Therapies, Cambridge, MA, USA) and agalsidase beta (Fabrazyme; Genzyme Corporation, Cambridge, MA, USA), were approved by the European Agency for the Evaluation of Medicinal Products in 2001; agalsidase alfa at a recommended dose of 0.2 mg/kg and agalsidase beta at a recommended dose of 1 mg/kg. In the US, however, orphan drug laws dictated that only one of these products could be approved. In April 2003, after a rigorous evaluation of both products by the US FDA, this approval was granted to agalsidase beta. This decision reflected clinical trial design, how dosages were determined, antibody effects and the ability of each product to demonstrate either clinical efficacy or reduction of tissue storage of GL-3 in major organs of pathology when administered at the recommended dosage. The process also highlighted important issues in the evaluation of drugs to treat life-threatening genetic diseases for which the pathological basis is well-defined.

  16. Beta-lactamase targeted enzyme activatable photosensitizers for antimicrobial PDT

    NASA Astrophysics Data System (ADS)

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

    2009-06-01

    Photodynamic therapy (PDT) as a treatment modality for infectious disease has shown promise. However, most of the antimicrobial photosensitizers (PS) non-preferentially accumulate in both bacteria and host tissues, causing host tissue phototoxicity during treatment. We have developed a new antimicrobial PDT strategy which exploits beta-lactam resistance mechanism, one of the major drug-resistance bacteria evolved, to achieve enhanced target specificity with limited host damage. Our strategy comprises a prodrug construct with a PS and a quencher linked by beta-lactam ring, resulting in a diminished phototoxicity. This construct, beta-lactamase enzyme-activated-photosensitizer (beta-LEAP), can only be activated in the presence of both light and bacteria, and remains inactive elsewhere such as mammalian tissue. Beta-LEAP construct had shown specific cleavage by purified beta-lactamase and by beta-lactamase over-expressing methicillin resistant Staphylococcus aureus (MRSA). Specific photodynamic toxicity was observed towards MRSA, while dark and light toxicity were equivalent to reference strains. The prodrug design, synthesis and photophysical properties will be discussed.

  17. Photo-triggered fluorescent theranostic prodrugs as DNA alkylating agents for mechlorethamine release and spatiotemporal monitoring.

    PubMed

    Cao, Yanting; Pan, Rong; Xuan, Weimin; Wei, Yongyi; Liu, Kejian; Zhou, Jiahong; Wang, Wei

    2015-06-28

    We describe a new theranostic strategy for selective delivery and spatiotemporal monitoring of mechlorethamine, a DNA alkylating agent. A photo-responsive prodrug is designed and composed of a photolabile o-nitrophenylethyl group, a DNA alkylating mechlorethamine drug and a coumarin fluorophore. Masking of the "N" in mechlorethamine in a positively charged state in the prodrug renders it inactive, non-toxic, selective and non-fluorescent. Indeed, the stable prodrug shows negligible cytotoxicity towards normal cells with and without UV activation and is completely non-fluorescent. However, upon photo-irradiation, the active mechlorethamine is released and induces efficient DNA cross-links, accompanied by a strong fluorescence enhancement (152 fold). Furthermore, DNA cross-linking activity from the release can be transformed into anticancer activity observed in in vitro studies of tumor cells. Importantly, the drug release progress and the movement can be conveniently monitored by fluorescence spectroscopy. The mechanistic study proves that the DNA cross-linking activity is mainly due to the release of DNA alkylating mechlorethamine. Altogether, the studies show the power of the theranostic strategy for efficient therapy in cancer treatment.

  18. A prodrug-doped cellular Trojan Horse for the potential treatment of prostate cancer.

    PubMed

    Levy, Oren; Brennen, W Nathaniel; Han, Edward; Rosen, David Marc; Musabeyezu, Juliet; Safaee, Helia; Ranganath, Sudhir; Ngai, Jessica; Heinelt, Martina; Milton, Yuka; Wang, Hao; Bhagchandani, Sachin H; Joshi, Nitin; Bhowmick, Neil; Denmeade, Samuel R; Isaacs, John T; Karp, Jeffrey M

    2016-06-01

    Despite considerable advances in prostate cancer research, there is a major need for a systemic delivery platform that efficiently targets anti-cancer drugs to sites of disseminated prostate cancer while minimizing host toxicity. In this proof-of-principle study, human mesenchymal stem cells (MSCs) were loaded with poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) that encapsulate the macromolecule G114, a thapsigargin-based prostate specific antigen (PSA)-activated prodrug. G114-particles (∼950 nm in size) were internalized by MSCs, followed by the release of G114 as an intact prodrug from loaded cells. Moreover, G114 released from G114 MP-loaded MSCs selectively induced death of the PSA-secreting PCa cell line, LNCaP. Finally, G114 MP-loaded MSCs inhibited tumor growth when used in proof-of-concept co-inoculation studies with CWR22 PCa xenografts, suggesting that cell-based delivery of G114 did not compromise the potency of this pro-drug in-vitro or in-vivo. This study demonstrates a potentially promising approach to assemble a cell-based drug delivery platform, which inhibits cancer growth in-vivo without the need of genetic engineering. We envision that upon achieving efficient homing of systemically infused MSCs to cancer sites, this MSC-based platform may be developed into an effective, systemic 'Trojan Horse' therapy for targeted delivery of therapeutic agents to sites of metastatic PCa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. TIMP-2 mediates the anti-invasive effects of the nitric oxide-releasing prodrug JS-K in breast cancer cells.

    PubMed

    Simeone, Ann-Marie; McMurtry, Vanity; Nieves-Alicea, René; Saavedra, Joseph E; Keefer, Larry K; Johnson, Marcella M; Tari, Ana M

    2008-01-01

    Tumor invasion and metastasis remain a major cause of mortality in breast cancer patients. High concentrations of nitric oxide (NO) suppress tumor invasion and metastasis in vivo. NO prodrugs generate large amounts of NO upon metabolism by appropriate intracellular enzymes, and therefore could have potential in the prevention and therapy of metastatic breast cancer. The present study was designed to determine the effects of the NO-releasing prodrug O2-(2,4-dinitrophenyl) 1- [(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K) on breast cancer invasion and the mechanisms involved. MDA-MB-231, MDA-MB-231/F10, and MCF-7/COX-2 were the three breast cancer cell lines tested. NO levels were determined spectrophotometrically using a NO assay kit. Invasion and the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of MMPs were determined using Matrigel invasion assays, an MMP array kit and ELISAs. The activity and expression of extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase mitogen-activated protein kinases were determined using western blot analyses. Under conditions by which JS-K was not cytotoxic, JS-K significantly decreased (P < 0.05) the invasiveness of breast cancer cells across the Matrigel basement membrane, which was directly correlated with NO production. JS-43-126, a non-NO-releasing analog of JS-K, had no effect on NO levels or invasion. JS-K increased (P < 0.05) TIMP-2 production, and blocking TIMP-2 activity with a neutralizing antibody significantly increased (P < 0.05) the invasive activity of JS-K-treated cells across Matrigel. JS-K decreased p38 activity, whereas the activity and the expression of extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase were unaffected. We report the novel findings that JS-K inhibits breast cancer invasion across the Matrigel basement membrane, and NO production is vital for this activity. Upregulation of TIMP-2 production is one mechanism by which

  20. The outcome of clinical parameters in adults with severe Type I Gaucher disease using very low dose enzyme replacement therapy.

    PubMed

    Wilson, Callum; Spearing, Ruth; Teague, Lochie; Robertson, Patsy; Blacklock, Hilary

    2007-01-01

    Enzyme replacement therapy is now well established as the treatment of choice in Type I Gaucher disease. Historically higher dosage regimens have been used in preference to lower doses despite the little clinical evidence in the way of large controlled clinical trials to support this. Moreover, the extraordinary cost of therapy means that not all eligible patients are able to be treated at the higher dose. Twelve type I adult patients with relatively severe disease were commenced on a very low dose of 7.5U of alglucerase/imiglucerase per kg every two weeks (initially given thrice weekly and later weekly). Follow-up 5 year data reveal a good visceral and haematological response with outcomes consistent with recently published treatment guidelines. Satisfactory clinical and radiological skeletal improvement was also demonstrated in most patients. Three patients had an inadequate overall skeletal response to therapy. Biomarkers also steadily improved although perhaps not quite at the same rate as that seen in higher doses. Very low dose enzyme replacement therapy may be appropriate for adult type I Gaucher patients with mild-moderate skeletal disease.

  1. Enzyme replacement therapy stabilized white matter lesion progression in Fabry disease.

    PubMed

    Fellgiebel, Andreas; Gartenschläger, Martin; Wildberger, Kerstin; Scheurich, Armin; Desnick, Robert J; Sims, Katherine

    2014-01-01

    The central nervous system manifestations in Fabry disease (FD) include progressive white matter lesions (WMLs) and stroke. Due to progressive microvascular involvement, men and women with FD over 35 years of age develop WMLs. Moreover, the prevalence of stroke has been estimated to be 12 times higher in FD compared with the general population. Enzyme replacement therapy (ERT) is available and has shown beneficial effects on renal, cardiac, and peripheral nerve function in FD, but the ERT effect on the progression of WMLs, or the reduction in cerebrovascular events, remains unknown. The WML burden and the effect of agalsidase beta 1 mg/kg biweekly on WML progression were assessed longitudinally in a Phase 4 agalsidase-beta placebo-controlled analysis of untreated and treated FD patients with mild-to-moderate renal involvement (serum creatinine measurements of ≥1.2 mg/dl and <3.0 mg/dl). The primary end point was the difference in the number of patients with increased WML burden between the agalsidase beta and placebo groups at the end of treatment. The diameters of the WMLs were determined manually using axial flow-attenuated-inversion-recovery-weighted magnetic resonance imaging (MRI) scans taken at baseline and follow-up. MRI scans from 41 FD patients (mean age 43.9, age range 20-68, 3 females; n=25 on ERT, n=16 on placebo) were analyzed. WML burden was present in 63% of patients at baseline, increased over a mean of 27 months (range 12-33 months) follow-up, and correlated with left ventricular hypertrophy (LVPW). Patients with previous or recent strokes (n=11, 39-68 years) showed an increase in the number of WMLs (p=0.005). A greater proportion of younger patients (≤50 years) on ERT (n=18) had stable WML burden compared with younger patients in the placebo group (n=13): 44% (8 of 18) versus 31% (4 of 13), p=0.014. The number needed to treat was 8. This FD patient cohort, with mild-to-moderate renal involvement, had a significant WML burden and high inter

  2. [The Russian consensus on the diagnosis and treatment of chronic pancreatitis: Enzyme replacement therapy].

    PubMed

    Khatkov, I E; Maev, I V; Bordin, D S; Kucheryavyi, Yu A; Abdulkhakov, S R; Alekseenko, S A; Alieva, E I; Alikhanov, R B; Bakulin, I G; Baranovsky, A Yu; Beloborodova, E V; Belousova, E A; Buriev, I M; Bystrovskaya, E V; Vertyankin, S V; Vinokurova, L V; Galperin, E I; Gorelov, A V; Grinevich, V B; Danilov, M V; Darvin, V V; Dubtsova, E A; Dyuzheva, T G; Egorov, V I; Efanov, M G; Zakharova, N V; Zagainov, V E; Ivashkin, V T; Izrailov, R E; Korochanskaya, N V; Kornienko, E A; Korobka, V L; Kokhanenko, N Yu; Livzan, M A; Loranskaya, I D; Nikolskaya, K A; Osipenko, M F; Okhlobystin, A V; Pasechnikov, V D; Plotnikova, E Yu; Polyakova, S I; Sablin, O A; Simanenkov, V I; Ursova, N I; Tsvirkun, V V; Tsukanov, V V; Shabunin, A V

    Russian National Research Medical University, Ministry of Health of Russia, Moscow; 26A.M. Nikiforov All-Russian Center of Emergency and Radiation Medicine, Russian Ministry for Civil Defense, Emergencies and Elimination of Consequences of Natural Disasters, Saint Petersburg; 27Research Institute for Medical Problems of the North, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk; 28S.P. Botkin City Clinical Hospital, Moscow Healthcare Department, Moscow; 29Tver State Medical University, Ministry of Health of Russia, Tver The Russian consensus on the diagnosis and treatment of chronic pancreatitis has been prepared on the initiative of the Russian Pancreatology Club to clarify and consolidate the opinions of Russian specialists (gastroenterologists, surgeons, and pediatricians) on the most significant problems of diagnosis and treatment of chronic pancreatitis. This article continues a series of publications explaining the most significant interdisciplinary consensus statements and deals with enzyme replacement therapy.

  3. Cost-effectiveness of enzyme replacement therapy for type 1 Gaucher disease

    PubMed Central

    2014-01-01

    Objective To evaluate the cost-effectiveness of enzyme replacement therapy (ERT) compared to standard medical care without ERT in the Dutch cohort of patients with type 1 Gaucher disease (GD I). Design Cost-effectiveness analysis was performed using a life-time state-transition model of the disease’s natural course. Transition probabilities, effectiveness data and costs were derived from retrospective data and prospective follow-up of the Dutch study cohort. Setting The tertiary referral center for Gaucher disease in the Netherlands. Participants The Dutch cohort of patients with GD I. Intervention ERT versus standard medical care without ERT in symptomatic patients. Main outcome measures Years free of end organ damage (YFEOD) (splenectomy, bone complication, malignancy, multiple complications), quality adjusted life years (QALY), and costs. Results Over an 85 year lifetime, an untreated GD I patient will generate 48.9 YFEOD and 55.86 QALYs. Starting ERT in a symptomatic patient increases the YFEOD by 12.8 years, while the number of QALYs gained increases by 6.27. The average yearly ERT medication costs range between €124,000 and €258,000 per patient. The lifetime costs of ERT starting in the symptomatic stage are €5,716,473 against €171,780 without ERT, a difference of €5,544,693. Consequently, the extra costs per additional YFEOD or per additional QALY are €434,416 and €884,994 respectively. After discounting effects by 1.5% and costs by 4% and under a reasonable scenario of ERT unit cost reduction by 25%, these incremental cost-effectiveness ratios could decrease to €149,857 and €324,812 respectively. Discussion ERT is a highly potential drug for GD I with substantial health gains. The conservatively estimated incremental cost-effectiveness ratios are substantially lower than for Pompe and Fabry disease. We suggest that the high effectiveness has contributed importantly to acceptance of reimbursement of ERT for GD I. The present study may

  4. Analgesic Prodrugs for Combating their Side-Effects: Rational Approach.

    PubMed

    Ruchita; Sucheta; Nanda, Sanju; Pathak, Dharampal

    2017-01-01

    Analgesics are the drugs which bring insensibility to pain without loosing consciousness. Treatment strategy is generally based on the type of pain. Most of the analgesics are associated with serious side effects, such as NSAIDS can cause severe GI disturbance and opioids can cause addiction. There are various ways to reduce their side effects The analgesic prodrug approach is one of the several strategies used to attain the required pharmacological response with a considerable decrease in side effects. The aim of this paper is to introduce in depth the rational behind the use of the analgesic prodrug approach from past to present. Data is collected from online as well as from extensive literature survey which have appeared on this subject during the last decades. This review will map the origins and development of the most important of the analgesic prodrugs to date. This review indicates that, designing analgesic prodrugs represent successful strategy to gain the required pharmacological activity with a considerable decrease in side effects. However thorough knowledge of diverse biological phenomena is needed which enables scientists to invent and design superior, nontoxic and better-targeted prodrugs. The newly synthesized chemical entity or prodrugs may or may not have intrinsic pharmacological activity and also synthesizing novel molecules consume a lot of time and money than developing prodrugs of existing clinically used analgesic drugs which is surely an attractive and promising area of research now a days. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Slow self-activation enhances the potency of viridin prodrugs.

    PubMed

    Blois, Joseph; Yuan, Hushan; Smith, Adam; Pacold, Michael E; Weissleder, Ralph; Cantley, Lewis C; Josephson, Lee

    2008-08-14

    When the viridin wortmannin (Wm) is modified by reaction with certain nucleophiles at the C20 position, the compounds obtained exhibit an improved antiproliferative activity even though a covalent reaction between C20 and a lysine in the active site of PI3 kinase is essential to Wm's ability to inhibit this enzyme. Here we show that this improved potency results from an intramolecular attack by the C6 hydroxyl group that slowly converts these inactive prodrugs to the active species Wm over the 48 h duration of the antiproliferative assay. Our results provide a guide for selecting Wm-like compounds to maximize kinase inhibition with the variety of protocols used to assess the role of PI3 kinase in biological systems, or for achieving optimal therapeutic effects in vivo . In addition, the slow self-activation of WmC20 derivatives provides a mechanism that can be exploited to obtain kinase inhibitors endowed with physical and pharmacokinetic properties far different from man-made kinase inhibitors because they do not bind to kinase active sites.

  6. Endothelial Targeting of Semi-permeable Polymer Nanocarriers for Enzyme Therapies

    PubMed Central

    Dziubla, Thomas D; Shuvaev, Vladimir V.; Hong, Nan Kang; Hawkins, Brian; Muniswamy, Madesh; Takano, Hajime; Simone, Eric; Nakada, Marian T.; Fisher, Aron; Albelda, Steven M.; Muzykantov, Vladimir R.

    2007-01-01

    The medical utility of proteins, e.g. therapeutic enzymes, is greatly restricted by their liable nature and inadequate delivery. Most therapeutic enzymes do not accumulate in their targets and are inactivated by proteases. Targeting of enzymes encapsulated into substrate-permeable Polymeric Nano-Carriers (PNC) impermeable for proteases might overcome these limitations. To test this hypothesis, we designed endothelial targeted PNC loaded with catalase, the H2O2-detoxifying enzyme, and tested if this approach protects against vascular oxidative stress, a pathological process implicated in ischemia-reperfusion and other disease conditions. Encapsulation of catalase (MW 240KD), peroxidase (MW 42kD) and xanthine oxidase (XO, MW 300 kD) into ~300nm diameter PNC composed of co-polymers of PEG-PLGA (polyethylene glycol and poly-lactic/poly-glycolic acid) was in the range ~10% for all enzymes. PNC/catalase and PNC/peroxidase were protected from external proteolysis and exerted the enzymatic activity on their PNC diffusible substrates, H2O2 and ortho-phenylendiamine, whereas activity of encapsulated XO was negligible due to polymer impermeability to the substrate. PNC targeted to platelet-endothelial cell adhesion molecule-1 delivered active encapsulated catalase to endothelial cells and protected the endothelium against oxidative stress in cell culture and animal studies. Vascular targeting of PNC-loaded detoxifying enzymes may find wide medical applications including management of oxidative stress and other toxicities. PMID:17950837

  7. Ocular drug metabolism of the bioactivating antioxidant N-acetylcarnosine for vision in ophthalmic prodrug and codrug design and delivery.

    PubMed

    Babizhayev, Mark A

    2008-10-01

    The basic idea in this study relates to the interesting research problem to employ with the knowledgeable pharmacy staff N-acetylcarnosine (NAC) in the developed suitable compounded prodrug ophthalmic preparations, which are currently used for the treatment of cataract and have antioxidant effect, in order to provide the molecular support to one of the most popular beliefs of the growing market for the treatment of senile cataract in patients and animals with efficacious NAC drug formulations worldwide patented by the author. This work presents the progress in ocular NAC prodrug and codrug design and delivery in light of revealed ocular metabolic activities. There is a considerable interest in the ophthalmic codrug design including NAC prodrug based on the strategies to improve ophthalmic drug delivery of the active peptide principal L-carnosine through the sustained intraocular metabolic activation of a dipeptide while making it resistant to enzymatic hydrolysis. Novel approaches to ocular NAC drug delivery, developed by Innovative Vision Products, Inc. (IVP), aim at enhancing the drug bioavailability by ensuring a prolonged retention of the medication in the eye, and/or by facilitating transcorneal penetration. IVP team studied the effects of lubricant eye drops designed as 1% NAC prodrug of L-carnosine containing a mucoadhesive cellulose-based and corneal absorption promoters in a drug delivery system. The predicted responses of the corneal and conjunctival penetrations to the synergistic promoters are useful in controlling the extent and pathway of the ocular and systemic absorptions of instilled NAC prodrug in designed ophthalmic formulations thereof. Utility of peptidase enzyme inhibitors in the codrug formulation to modulate the transport and metabolism of NAC prodrug appears to be a promising strategy for enhancing dipeptide drug transport across the cornea. The developed and officially CE mark registered by IVP NAC prodrug and codrug lubricating eye drop

  8. Switch from agalsidase beta to agalsidase alfa in the enzyme replacement therapy of patients with Fabry disease in Latin America.

    PubMed

    Ripeau, Diego; Amartino, Hernán; Cedrolla, Martín; Urtiaga, Luis; Urdaneta, Bella; Cano, Marilis; Valdez, Rita; Antongiovanni, Norberto; Masllorens, Francisca

    2017-01-01

    There are currently two available enzyme replacement therapies for Fabry disease and little information regarding efficacy and safety of switching therapies. Between 2009 and 2012 there was a worldwide shortage of agalsidase beta and patients on that enzyme were switched to agalsidase alfa. This retrospective observational study assessed a 2-year period of efficacy and safety in a population of Fabry patients, in Argentina (30 patients) and Venezuela (3 patients), who switched therapies from algasidase beta to agalsidase alfa. Thirty-three patients completed 24-months follow-up after the switch (age 32.4 ± 2.0, range 10.0-55.9 years; male: female 23:10). Measures of renal function such as estimated glomerular filtration rate remained almost unchanged in 31 patients without end stage renal disease over the 2 years after switching and urine protein excretion continued stable. Cardiac functional parameters: left ventricular mass index, interventricular septum, left ventricular posterior wall showed no significant change from baseline in the 33 patients. Quality of life, pain and disease severity scores were mostly unchanged after 24-months and agalsidase alfa was generally well tolerated. Our findings showed there is no significant change in the efficacy measured through the renal or cardiac function, quality of life, pain, disease severity scoring and safety for at least 2 years after switching from agalsidase beta to agalsidase alfa.

  9. Effect of Simvastatin Prodrug on Experimental Periodontitis.

    PubMed

    Bradley, Aaron D; Zhang, Yijia; Jia, Zhenshan; Zhao, Gang; Wang, Xiaobei; Pranke, Laura; Schmid, Marian J; Wang, Dong; Reinhardt, Richard A

    2016-05-01

    Local application of statins has shown potential in preventing and regenerating bone loss associated with experimental periodontitis. This study evaluates the effect of a novel simvastatin (SIM) prodrug (capable of delivering high doses to periodontitis inflammatory lesion and cells) on experimental periodontitis bone loss and inflammation. Forty mature female Sprague Dawley rats were subjected to ligature-induced experimental periodontitis between maxillary first and second molars (M1-M2). Equal groups were treated with three weekly doses of: 1) prodrug carrier alone (mPEG); 2) 0.5 mg SIM dose equivalent in carrier (SIM/SIM-mPEG); 3) 1.0 mg SIM/SIM-mPEG; 4) 1.5 mg SIM/SIM-mPEG; or 5) ligature alone. Contralateral molars served as unmanipulated controls. Four weeks after initiation of periodontitis, animals were euthanized, the M1-M2 interproximal was evaluated with microcomputed tomography and histology, and data were analyzed with one-way analysis of variance. Ligature alone caused a mean bone loss of 1.01 ± 0.06 mm from the cemento-enamel junction, whereas all doses of SIM/SIM-mPEG reduced bone loss, especially 1.5 mg SIM/SIM-mPEG (0.68 ± 0.05 mm, P <0.001), which was not statistically different from contralateral control (0.47 ± 0.06 mm). A dose of 1.5 mg SIM/SIM-mPEG also reduced percentage of neutrophils compared with carrier alone (2.0% ± 1.0% versus 5.7% ± 1.1%; P <0.05), and increased amount of uninflamed connective tissue in the M1-M2 interproximal area (65.2% ± 3.3% versus 46.3% ± 3.3%; P <0.001). The mPEG carrier alone did not have bone-sparing or anti-inflammatory properties. Multiple local 1.5-mg doses of a macromolecular SIM prodrug decreases amount of experimental periodontitis bone loss and inflammation in rats.

  10. [Enzyme replacement therapy in patients with Fabry disease: state of the art and review of the literature].

    PubMed

    Riccio, Eleonora; Capuano, Ivana; Visciano, Bianca; Marchetiello, Cristina; Petrillo, Fortunato; Pisani, Antonio

    2013-01-01

    Anderson-Fabry disease is a hereditary X-linked lysosomal storage disorder caused by a deficiency of the lysosomal enzyme alpha galactosidase A. It results in the accumulation of the glycosphingolypid globotrioasoyl ceramide (Gb3 in different cells and organs, resulting in a multi-system pathology including end organ failure. Patients with Fabry disease present clinically with cardiac, renal and neurological involvement; both life expectancy and quality of life are severely compromised. The current causal treatment for Fabry disease is enzyme replacement therapy (ERT), available since 2001. The two recombinant preparations available for ERT are agalsidase alfa (Replagal) and agalsidase beta (Fabrazyme). They have both been showed to have positive effect on kidney and heart, on the symptoms of pain and quality of life. Few data to date are available on comparison of the two preparations of ERT. This article reviews evidence of the literature and shows our personal experience about the safety and efficacy of ERT.

  11. Uneventful pregnancy outcome after enzyme replacement therapy with agalsidase beta in a heterozygous female with Fabry disease: A case report.

    PubMed

    Germain, Dominique P; Bruneval, Patrick; Tran, Thi-Chien; Balouet, Pierre; Richalet, Bernard; Benistan, Karelle

    2010-01-01

    No reproductive studies have been performed with enzyme replacement therapy (ERT) for Fabry disease (FD, OMIM 301500), a lysosomal storage disorder. Therefore, use during pregnancy is theoretically contraindicated. We report the first case of agalsidase beta treatment throughout pregnancy. High-range proteinuria remained stable and the patient gave birth to a healthy boy after an uncomplicated pregnancy. The decision to administer ERT during pregnancy should be made on an individual basis, considering the FD status and possible risks. Copyright 2009 Elsevier Masson SAS. All rights reserved.

  12. Ocular Sustained Release Nanoparticles Containing Stereoisomeric Dipeptide Prodrugs of Acyclovir

    PubMed Central

    Jwala, Jwala; Boddu, Sai H.S.; Shah, Sujay; Sirimulla, Suman; Pal, Dhananjay

    2011-01-01

    Abstract Purpose The objective of this study was to develop and characterize polymeric nanoparticles of appropriate stereoisomeric dipeptide prodrugs of acyclovir (L-valine-L-valine-ACV, L-valine-D-valine-ACV, D-valine-L-valine-ACV, and D-valine-D-valine-ACV) for the treatment of ocular herpes keratitis. Methods Stereoisomeric dipeptide prodrugs of acyclovir (ACV) were screened for bioreversion in various ocular tissues, cell proliferation, and uptake across the rabbit primary corneal epithelial cell line. Docking studies were carried out to examine the affinity of prodrugs to the peptide transporter protein. Prodrugs with optimum characteristics were selected for the preparation of nanoparticles using various grades of poly (lactic-co-glycolic acid) (PLGA). Nanoparticles were characterized for the entrapment efficiency, surface morphology, size distribution, and in vitro release. Further, the effect of thermosensitive gels on the release of prodrugs from nanoparticles was also studied. Results L-valine-L-valine-ACV and L-valine-D-valine-ACV were considered to be optimum in terms of enzymatic stability, uptake, and cytotoxicity. Docking results indicated that L-valine in the terminal position increases the affinity of the prodrugs to the peptide transporter protein. Entrapment efficiency values of L-valine-L-valine-ACV and L-valine-D-valine-ACV were found to be optimal with PLGA 75:25 and PLGA 65:35 polymers, respectively. In vitro release of prodrugs from nanoparticles exhibited a biphasic release behavior with initial burst phase followed by sustained release. Dispersion of nanoparticles in thermosensitive gels completely eliminated the burst release phase. Conclusion Novel nanoparticulate systems of dipeptide prodrugs of ACV suspended in thermosensitive gels may provide sustained delivery after topical administration. PMID:21500985

  13. The synthesis of amphipathic prodrugs of 1,2-diol drugs with saccharide conjugates by high regioselective enzymatic protocol.

    PubMed

    Quan, Jing; Chen, Zhichun; Han, Chengyou; Lin, Xianfu

    2007-02-15

    A facile, high regioselective enzymatic synthesis approach for the preparation of amphipathic prodrugs with saccharides of mephenesin and chlorphenesin was developed. Firstly, transesterification of two drugs with divinyl dicarboxylates with different carbon chain length was performed under the catalysis of Candida antarctica lipase acrylic resin and Lipozyme in anhydrous acetone at 50 degrees C, respectively. A series of lipophilic derivatives with vinyl groups of mephenesin and chlorphenesin were prepared. The influences of different organic solvents, enzyme sources, reaction time, and the acylation reagents on the synthesis of vinyl esters were investigated. And then, protease-catalyzed high regioselective acylation of D-glucose and D-mannose with vinyl esters of mephenesin and chlorphenesin gave drug-saccharide derivatives in good yields. The studies of lipophilicity and hydrolysis in vitro of prodrugs verified that drug-saccharide derivatives had amphipathic properties, and both lipophilic and amphipathic drug derivatives had obvious controlled release characteristics.

  14. Direct Real-Time Monitoring of Prodrug Activation by Chemiluminescence.

    PubMed

    Gnaim, Samer; Scomparin, Anna; Das, Sayantan; Blau, Rachel; Satchi-Fainaro, Ronit; Shabat, Doron

    2018-05-22

    The majority of theranostic prodrugs reported so far relay information through a fluorogenic response generated upon release of the active chemotherapeutic agent. A chemiluminescence detection mode offers significant advantages over fluorescence, mainly due to the superior signal-to-noise ratio of chemiluminescence. Here we report the design and synthesis of the first theranostic prodrug monitored by a chemiluminescence diagnostic mode. As a representative model, we prepared a prodrug from the chemotherapeutic monomethyl auristatin E, which was modified for activation by β-galactosidase. The activation of the prodrug in the presence of β-galactosidase is accompanied by emission of a green photon. Light emission intensities, which increase with increasing concentration of the prodrug, were linearly correlated with a decrease in the viability of a human cell line that stably expresses β-galactosidase. We obtained sharp intravital chemiluminescent images of endogenous enzymatic activity in β-galactosidase-overexpressing tumor-bearing mice. The exceptional sensitivity achieved with the chemiluminescence diagnostic mode should allow the exploitation of theranostic prodrugs for personalized cancer treatment. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Cost-effectiveness of enzyme replacement therapy with alglucosidase alfa in classic-infantile patients with Pompe disease

    PubMed Central

    2014-01-01

    Background Infantile Pompe disease is a rare metabolic disease. Patients generally do not survive the first year of life. Enzyme replacement therapy (ERT) has proven to have substantial effects on survival in infantile Pompe disease. However, the costs of therapy are very high. In this paper, we assess the cost-effectiveness of enzyme replacement therapy in infantile Pompe disease. Methods A patient simulation model was used to compare costs and effects of ERT with costs of effects of supportive therapy (ST). The model was filled with data on survival, quality of life and costs. For both arms of the model, data on survival were obtained from international literature. In addition, survival as observed among 20 classic-infantile Dutch patients, who all received ERT, was used. Quality of life was measured using the EQ-5D and assumed to be the same in both treatment groups. Costs included the costs of ERT (which depend on a child’s weight), infusions, costs of other health care utilization, and informal care. A lifetime time horizon was used, with 6-month time cycles. Results Life expectancy was significantly longer in the ERT group than in the ST group. On average, ST receiving patients were modelled not to survive the first half year of life; whereas the life expectancy in the ERT patients was modelled to be almost 14 years. Lifetime incremental QALYs were 6.8. Incremental costs were estimated to be € 7.0 million, which primarily consisted of treatment costs (95%). The incremental costs per QALY were estimated to be € 1.0 million (range sensitivity analyses: € 0.3 million - € 1.3 million). The incremental cost per life year gained was estimated to be € 0.5 million. Conclusions The incremental costs per QALY ratio is far above the conventional threshold values. Results from univariate and probabilistic sensitivity analyses showed the robustness of the results. PMID:24884717

  16. Multilocus Genotypes of Relevance for Drug Metabolizing Enzymes and Therapy with Thiopurines in Patients with Acute Lymphoblastic Leukemia

    PubMed Central

    Stocco, Gabriele; Franca, Raffaella; Verzegnassi, Federico; Londero, Margherita; Rabusin, Marco; Decorti, Giuliana

    2013-01-01

    Multilocus genotypes have been shown to be of relevance for using pharmacogenomic principles to individualize drug therapy. As it relates to thiopurine therapy, genetic polymorphisms of TPMT are strongly associated with the pharmacokinetics and clinical effects of thiopurines (mercaptopurine and azathioprine), influencing their toxicity and efficacy. We have recently demonstrated that TPMT and ITPA genotypes constitute a multilocus genotype of pharmacogenetic relevance for children with acute lymphoblastic leukemia (ALL) receiving thiopurine therapy. The use of high-throughput genomic analysis allows identification of additional candidate genetic factors associated with pharmacogenetic phenotypes, such as TPMT enzymatic activity: PACSIN2 polymorphisms have been identified by a genome-wide analysis, combining evaluation of polymorphisms and gene expression, as a significant determinant of TPMT activity in the HapMap CEU cell lines and the effects of PACSIN2 on TPMT activity and mercaptopurine induced adverse effects were confirmed in children with ALL. Combination of genetic factors of relevance for thiopurine metabolizing enzyme activity, based on the growing understanding of their association with drug metabolism and efficacy, is particularly promising for patients with pediatric ALL. The knowledge basis and clinical applications for multilocus genotypes of importance for therapy with mercaptopurine in pediatric ALL is discussed in the present review. PMID:23335936

  17. Enzyme replacement therapy in patients with Fabry disease: state of the art and review of the literature.

    PubMed

    Pisani, Antonio; Visciano, Bianca; Roux, Graciana Diez; Sabbatini, Massimo; Porto, Caterina; Parenti, Giancarlo; Imbriaco, Massimo

    2012-11-01

    Anderson-Fabry disease is an X-linked lysosomal storage disorder resulting from the deficiency of the hydrolytic enzyme alpha galactosidase A, with consequent accumulation of globotrioasoyl ceramide in cells and tissues of the body, resulting in a multi-system pathology including end organ failure. In the classical phenotype, cardiac failure, renal failure and stroke result in a reduced median life expectancy. The current causal treatment for Fabry disease is the enzyme replacement therapy (ERT): two different products, Replagal (agalsidase alfa) and Fabrazyme (agalsidase beta), have been commercially available in Europe for almost 10 years and they are both indicated for long-term treatment. In fact, clinical trials, observational studies and registry data have provided many evidences for safety and efficacy of ERT in improving symptoms of pain, gastrointestinal disturbances, hypohidrosis, left ventricular mass index, glomerular filtration rate and quality of life. Few data are available on comparison of the two treatments and on the clinical course of the disease. This article reviews the published evidence for clinical efficacy of the two available enzyme preparations. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Leveraging Hypoxia-Activated Prodrugs to Prevent Drug Resistance in Solid Tumors.

    PubMed

    Lindsay, Danika; Garvey, Colleen M; Mumenthaler, Shannon M; Foo, Jasmine

    2016-08-01

    Experimental studies have shown that one key factor in driving the emergence of drug resistance in solid tumors is tumor hypoxia, which leads to the formation of localized environmental niches where drug-resistant cell populations can evolve and survive. Hypoxia-activated prodrugs (HAPs) are compounds designed to penetrate to hypoxic regions of a tumor and release cytotoxic or cytostatic agents; several of these HAPs are currently in clinical trial. However, preliminary results have not shown a survival benefit in several of these trials. We hypothesize that the efficacy of treatments involving these prodrugs depends heavily on identifying the correct treatment schedule, and that mathematical modeling can be used to help design potential therapeutic strategies combining HAPs with standard therapies to achieve long-term tumor control or eradication. We develop this framework in the specific context of EGFR-driven non-small cell lung cancer, which is commonly treated with the tyrosine kinase inhibitor erlotinib. We develop a stochastic mathematical model, parametrized using clinical and experimental data, to explore a spectrum of treatment regimens combining a HAP, evofosfamide, with erlotinib. We design combination toxicity constraint models and optimize treatment strategies over the space of tolerated schedules to identify specific combination schedules that lead to optimal tumor control. We find that (i) combining these therapies delays resistance longer than any monotherapy schedule with either evofosfamide or erlotinib alone, (ii) sequentially alternating single doses of each drug leads to minimal tumor burden and maximal reduction in probability of developing resistance, and (iii) strategies minimizing the length of time after an evofosfamide dose and before erlotinib confer further benefits in reduction of tumor burden. These results provide insights into how hypoxia-activated prodrugs may be used to enhance therapeutic effectiveness in the clinic.

  19. Effects of vehicles and prodrug properties and their interactions on the delivery of 6-mercaptopurine through skin: S6-acyloxymethyl-6-mercaptopurine prodrugs.

    PubMed

    Waranis, R P; Sloan, K B

    1988-03-01

    A homologous series of S6-acyloxymethyl-6-mercaptopurine (6-mono-6-MP) and two 9-acyloxymethyl-6-mercaptopurine (9-mono-6-MP) prodrugs have been synthesized and characterized. The ability of the 6-mono-6-MP prodrugs to deliver 6-mercaptopurine (6-MP) through hairless mouse skin from isopropyl myristate (IPM) and propylene glycol (PG) has been evaluated. There was a good correlation between the log experimental permeability coefficients from the diffusion data and calculated solubility parameters of the prodrugs. Although there was no statistical difference between the rates of delivery of 6-MP by the acetyl through valeryl 6-mono-6-MP prodrugs from IPM, the butyryl and valeryl prodrugs were significantly better at delivering 6-MP from PG. For a given solubility parameter value, the 6-mono-6-MP prodrugs were less soluble in water and IPM, and more soluble in PG than the previously studied S6,9-bisacyloxymethyl-6-MP (6,9-bis-6-MP) prodrugs. On the other hand, for a given solubility parameter, the 6,9-bis-6-MP prodrugs were generally more effective at delivering 6-MP from IPM and PG. The single 9-mono-6-MP prodrug that was evaluated was much less effective at delivering 6-MP than either the 6-mono- or 6,9-bis-6-MP prodrugs. Thus, it is much less important to mask the imidazole than the thionamide functional group in 6-MP to enhance the topical delivery of 6-MP using a prodrug approach.

  20. [Effect of components and some protocols of anti-ulcer therapy on content and activity of monooxigenase system enzymes of the stomach mucosa in experimental stomach ulcer].

    PubMed

    Iakubov, A V; Pattakhova, M Kh

    2009-01-01

    The influence of components and some schemata of antiulcerous therapy on content and activity of monooxigenase system's enzymes in mucous membrane of stomach are studied on the model of experimental stomach ulcer in rats. It is established, that among components of antiulcerous therapy such as omeprazole, clarithromycin and metronidazole inhibit content and activity of MOS enzymes. Tinidazol, amoxicillin and azithromycin do not affect the function of MOS. Rifampicin and pantoprazole induce enzyme system of monooxigenase. In triple therapy with omeprazole, clarithromycin and metronidazole the inhibit effect of preparations to system of MOS is exponentiated and it leads to suppression of mucous cytoprotaction of gastro duodenal zone. Triple therapy of ulcerous disease with pantoprazole, rifampicin and azithromycin is effective planning to stimulate defense mechanisms of the organism.

  1. Enzyme replacement therapy started at birth improves outcome in difficult-to-treat organs in mucopolysaccharidosis I mice.

    PubMed

    Baldo, Guilherme; Mayer, Fabiana Q; Martinelli, Bárbara Z; de Carvalho, Talita G; Meyer, Fabiola S; de Oliveira, Patrícia G; Meurer, Luise; Tavares, Angela; Matte, Ursula; Giugliani, Roberto

    2013-05-01

    Since we previously observed that in patients with mucopolysaccharidosis (MPS) the storage of undegraded glycosaminoglycans (GAG) occurs from birth, in the present study we aimed to compare normal, untreated MPS I mice (knockout for alpha-l-iduronidase-IDUA), and MPS I mice treated with enzyme replacement therapy (ERT, Laronidase, 1.2mg/kg every 2 weeks) started from birth (ERT-neo) or from 2 months of age (ERT-ad). All mice were sacrificed at 6 months. Both treatments were equally effective in normalizing GAG levels in the viscera but had no detectable effect on the joint. Heart function was also improved with both treatments. On the other hand, mice treated from birth presented better outcomes in the difficult-to-treat aortas and heart valves. Surprisingly, both groups had improvements in behavior tests, and normalization of GAG levels in the brain and IDUA injection resulted in detectable levels of enzyme in the brain tissue 1h after administration. ERT-ad mice developed significantly more anti-IDUA-IgG antibodies, and mice that didn't develop antibodies had better performances in behavior tests, indicating that development of antibodies may reduce enzyme bioavailability. Our results suggest that ERT started from birth leads to better outcomes in the aorta and heart valves, as well as a reduction in antibody levels. Some poor vascularized organs, such as the joints, had partial or no benefit and ancillary therapies might be needed for patients. The results presented here support the idea that ERT started from birth leads to better treatment outcomes and should be considered whenever possible, a observation that gains relevance as newborn screening programs are being considered for MPS and other treatable lysosomal storage disorders. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Recent advances in targeting protein arginine methyltransferase enzymes in cancer therapy.

    PubMed

    Smith, Emily; Zhou, Wei; Shindiapina, Polina; Sif, Said; Li, Chenglong; Baiocchi, Robert A

    2018-05-21

    Exploration in the field of epigenetics has revealed the diverse roles of the protein arginine methyltransferase (PRMT) family of proteins in multiple disease states. These findings have led to the development of specific inhibitors and discovery of several new classes of drugs with potential to treat both benign and malignant conditions. Areas covered: We provide an overview on the role of PRMT enzymes in healthy and malignant cells, highlighting the role of arginine methylation in specific pathways relevant to cancer pathogenesis. Additionally, we describe structure and catalytic activity of PRMT and discuss the mechanisms of action of novel small molecule inhibitors of specific members of the arginine methyltransferase family. Expert opinion: As the field of PRMT biology advances, it's becoming clear that this class of enzymes is highly relevant to maintaining normal physiologic processes as well and disease pathogenesis. We discuss the potential impact of PRMT inhibitors as a broad class of drugs, including the pleiotropic effects, off target effects the need for more detailed PRMT-centric interactomes, and finally, the potential for targeting this class of enzymes in clinical development of experimental therapeutics for cancer.

  3. Triacylglycerol mimetics regulate membrane interactions of glycogen branching enzyme: implications for therapy.

    PubMed

    Alvarez, Rafael; Casas, Jesús; López, David J; Ibarguren, Maitane; Suari-Rivera, Ariadna; Terés, Silvia; Guardiola-Serrano, Francisca; Lossos, Alexander; Busquets, Xavier; Kakhlon, Or; Escribá, Pablo V

    2017-08-01

    Adult polyglucosan body disease (APBD) is a neurological disorder characterized by adult-onset neurogenic bladder, spasticity, weakness, and sensory loss. The disease is caused by aberrant glycogen branching enzyme (GBE) (GBE1Y329S) yielding less branched, globular, and soluble glycogen, which tends to aggregate. We explore here whether, despite being a soluble enzyme, GBE1 activity is regulated by protein-membrane interactions. Because soluble proteins can contact a wide variety of cell membranes, we investigated the interactions of purified WT and GBE1Y329S proteins with different types of model membranes (liposomes). Interestingly, both triheptanoin and some triacylglycerol mimetics (TGMs) we have designed (TGM0 and TGM5) markedly enhance GBE1Y329S activity, possibly enough for reversing APBD symptoms. We show that the GBE1Y329S mutation exposes a hydrophobic amino acid stretch, which can either stabilize and enhance or alternatively, reduce the enzyme activity via alteration of protein-membrane interactions. Additionally, we found that WT, but not Y329S, GBE1 activity is modulated by Ca 2+ and phosphatidylserine, probably associated with GBE1-mediated regulation of energy consumption and storage. The thermal stabilization and increase in GBE1Y329S activity induced by TGM5 and its omega-3 oil structure suggest that this molecule has a considerable therapeutic potential for treating APBD. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  4. Molecular Basis of Prodrug Activation by Human Valacyclovirase, an [alpha]-Amino Acid Ester Hydrolase

    SciTech Connect

    Lai, Longsheng; Xu, Zhaohui; Zhou, Jiahai

    2008-07-08

    Chemical modification to improve biopharmaceutical properties, especially oral absorption and bioavailability, is a common strategy employed by pharmaceutical chemists. The approach often employs a simple structural modification and utilizes ubiquitous endogenous esterases as activation enzymes, although such enzymes are often unidentified. This report describes the crystal structure and specificity of a novel activating enzyme for valacyclovir and valganciclovir. Our structural insights show that human valacyclovirase has a unique binding mode and specificity for amino acid esters. Biochemical data demonstrate that the enzyme hydrolyzes esters of {alpha}-amino acids exclusively and displays a broad specificity spectrum for the aminoacyl moiety similar tomore » tricorn-interacting aminopeptidase F1. Crystal structures of the enzyme, two mechanistic mutants, and a complex with a product analogue, when combined with biochemical analysis, reveal the key determinants for substrate recognition; that is, a flexible and mostly hydrophobic acyl pocket, a localized negative electrostatic potential, a large open leaving group-accommodating groove, and a pivotal acidic residue, Asp-123, after the nucleophile Ser-122. This is the first time that a residue immediately after the nucleophile has been found to have its side chain directed into the substrate binding pocket and play an essential role in substrate discrimination in serine hydrolases. These results as well as a phylogenetic analysis establish that the enzyme functions as a specific {alpha}-amino acid ester hydrolase. Valacyclovirase is a valuable target for amino acid ester prodrug-based oral drug delivery enhancement strategies.« less

  5. 1-Arylsulfonyl-2-(Pyridylmethylsulfinyl) Benzimidazoles as New Proton Pump Inhibitor Prodrugs

    PubMed Central

    Shin, Jai Moo; Sachs, George; Cho, Young-moon; Garst, Michael

    2010-01-01

    New arylsulfonyl proton pump inhibitor (PPI) prodrug forms were synthesized. These prodrugs provided longer residence time of an effective PPI plasma concentration, resulting in better gastric acid inhibition. PMID:20032890

  6. Rapid intranasal delivery of chloramphenicol acetyltransferase in the active form to different brain regions as a model for enzyme therapy in the CNS.

    PubMed

    Appu, Abhilash P; Arun, Peethambaran; Krishnan, Jishnu K S; Moffett, John R; Namboodiri, Aryan M A

    2016-02-01

    The blood brain barrier (BBB) is critical for maintaining central nervous system (CNS) homeostasis by restricting entry of potentially toxic substances. However, the BBB is a major obstacle in the treatment of neurotoxicity and neurological disorders due to the restrictive nature of the barrier to many medications. Intranasal delivery of active enzymes to the brain has therapeutic potential for the treatment of numerous CNS enzyme deficiency disorders and CNS toxicity caused by chemical threat agents. The aim of this work is to provide a sensitive model system for analyzing the rapid delivery of active enzymes into various regions of the brain with therapeutic bioavailability. We tested intranasal delivery of chloramphenicol acetyltransferase (CAT), a relatively large (75kD) enzyme, in its active form into different regions of the brain. CAT was delivered intranasally to anaesthetized rats and enzyme activity was measured in different regions using a highly specific High Performance Thin Layer Chromatography (HP-TLC)-radiometry coupled assay. Active enzyme reached all examined areas of the brain within 15min (the earliest time point tested). In addition, the yield of enzyme activity in the brain was almost doubled in the brains of rats pre-treated with matrix metalloproteinase-9 (MMP-9). Intranasal administration of active enzymes in conjunction with MMP-9 to the CNS is both rapid and effective. The present results suggest that intranasal enzyme therapy is a promising method for counteracting CNS chemical threat poisoning, as well as for treating CNS enzyme deficiency disorders. Published by Elsevier B.V.

  7. Synthesis and Characterization of a Phosphate Prodrug of Isoliquiritigenin.

    PubMed

    Boyapelly, Kumaraswamy; Bonin, Marc-André; Traboulsi, Hussein; Cloutier, Alexandre; Phaneuf, Samuel C; Fortin, Daniel; Cantin, André M; Richter, Martin V; Marsault, Eric

    2017-04-28

    Isoliquiritigenin (1) possesses a variety of biological activities in vitro. However, its poor aqueous solubility limits its use for subsequent in vivo experimentation. In order to enable the use of 1 for in vivo studies without the use of toxic carriers or cosolvents, a phosphate prodrug strategy was implemented relying on the availability of phenol groups in the molecule. In this study, a phosphate group was added to position C-4 of 1, leading to the more water-soluble prodrug 2 and its ammonium salt 3, which possesses increased stability compared to 2. Herein are reported the synthesis, characterization, solubility, and stability of phosphate prodrug 3 in biological medium in comparison to 1, as well as new results on its anti-inflammatory properties in vivo. As designed, the solubility of prodrug 3 was superior to that of the parent natural product 1 (9.6 mg/mL as opposed to 3.9 μg/mL). Prodrug 3 as an ammonium salt was also found to possess excellent stability as a solid and in aqueous solution, as opposed to its phosphoric acid precursor 2.

  8. Wild-type and mutated IDH1/2 enzymes and therapy responses.

    PubMed

    Molenaar, Remco J; Maciejewski, Jaroslaw P; Wilmink, Johanna W; van Noorden, Cornelis J F

    2018-04-01

    Isocitrate dehydrogenase 1 and 2 (IDH1/2) are key enzymes in cellular metabolism, epigenetic regulation, redox states, and DNA repair. IDH1/2 mutations are causal in the development and/or progression of various types of cancer due to supraphysiological production of D-2-hydroxyglutarate. In various tumor types, IDH1/2-mutated cancers predict for improved responses to treatment with irradiation or chemotherapy. The present review discusses the molecular basis of the sensitivity of IDH1/2-mutated cancers with respect to the function of mutated IDH1/2 in cellular processes and their interactions with novel IDH1/2-mutant inhibitors. Finally, lessons learned from IDH1/2 mutations for future clinical applications in IDH1/2 wild-type cancers are discussed.

  9. ELQ-300 prodrugs for enhanced delivery and single-dose cure of malaria.

    PubMed

    Miley, Galen P; Pou, Sovitj; Winter, Rolf; Nilsen, Aaron; Li, Yuexin; Kelly, Jane X; Stickles, Allison M; Mather, Michael W; Forquer, Isaac P; Pershing, April M; White, Karen; Shackleford, David; Saunders, Jessica; Chen, Gong; Ting, Li-Min; Kim, Kami; Zakharov, Lev N; Donini, Cristina; Burrows, Jeremy N; Vaidya, Akhil B; Charman, Susan A; Riscoe, Michael K

    2015-09-01

    ELQ-300 is a preclinical candidate that targets the liver and blood stages of Plasmodium falciparum, as well as the forms that are crucial to transmission of disease: gametocytes, zygotes, and ookinetes. A significant obstacle to the clinical development of ELQ-300 is related to its physicochemical properties. Its relatively poor aqueous solubility and high crystallinity limit absorption to the degree that only low blood concentrations can be achieved following oral dosing. While these low blood concentrations are sufficient for therapy, the levels are too low to establish an acceptable safety margin required by regulatory agencies for clinical development. One way to address the challenging physicochemical properties of ELQ-300 is through the development of prodrugs. Here, we profile ELQ-337, a bioreversible O-linked carbonate ester prodrug of the parent molecule. At the molar equivalent dose of 3 mg/kg of body weight, the delivery of ELQ-300 from ELQ-337 is enhanced by 3- to 4-fold, reaching a maximum concentration of drug in serum (C max) of 5.9 μM by 6 h after oral administration, and unlike ELQ-300 at any dose, ELQ-337 provides single-dose cures of patent malaria infections in mice at low-single-digit milligram per kilogram doses. Our findings show that the prodrug strategy represents a viable approach to overcome the physicochemical limitations of ELQ-300 to deliver the active drug to the bloodstream at concentrations sufficient for safety and toxicology studies, as well as achieving single-dose cures. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. AB073. Classic infantile-onset Pompe disease: phenotypes and outcomes of 5 Vietnamese patients receiving enzyme replacement therapy

    PubMed Central

    Nguyen, Khanh Ngoc; Do, Mai Thi Thanh; Can, Ngoc Thi Bich; Hwu, Wuh-Liang; Vu, Dung Chi

    2017-01-01

    Background Pompe disease (PD) or glycogen storage disease type II is a lysosomal storage disorder, caused by mutations of GAA gene which results in deficiency of acid alpha-glucosidase (GAA) enzyme that involves in metabolism of glycogen in the lysosomes. Its incidence is 1/14,000–1/100,000. PD is divided into three types: classic infantile onset, non-classic infantile onset, and late onset. Early enzyme replacement therapy (ERT) before developing respiratory distress may lead to good outcome. Since 2013, we have identified 16 cases with classic infantile-onset and 5 cases were treated with ERT. Herein, we describe phenotypes and outcomes of five infantile-onset PD patients who received ERT. Methods GAA enzyme assay was done at National Taiwan University Hospital. Results Ages of diagnosis were 12, 38 and 70 days, 5 and 9 months of age. Clinical presentations included macroglossia (5/5), hypertrophic cardiomyopathy (5/5), failure to thrive (5/5), facial weakness and hypotonia (3 patients diagnosed after 70 days of age), respiratory failure (1 patient diagnosed at 9 months of age). All patients had mildly elevated plasma CK (270–380 UI/L) and transaminase (60–260 UI/l). Ages at starting ERT were 28 and 58 days, 3, 6 and 10 months. The time intervals from diagnosis to starting ERT were between 14 days and 1 month. The durations of ERT were 4–22 months. The outcomes were good. All patients had improvement of cardiac functions shown on echocardiography, respiratory status, and motor development. The patient who first received ERT at 10 months of age was reportedly dead at home due to food obstruction at 18 months of age. Current ages of the survivors were 5–24 months. Conclusions Patients with classic infantile-onset PD will have good outcomes if ERT is started early. Newborn screening for this disease is necessary to yield an early diagnosis.

  11. Cardiac energy metabolism is disturbed in Fabry disease and improves with enzyme replacement therapy using recombinant human galactosidase A.

    PubMed

    Machann, Wolfram; Breunig, Frank; Weidemann, Frank; Sandstede, Jörn; Hahn, Dietbert; Köstler, Herbert; Neubauer, Stefan; Wanner, Christoph; Beer, Meinrad

    2011-03-01

    In vitro studies have shown impairment of energy metabolism in cardiac fibroblasts from Fabry patients. A recent in vivo study reported an association between cardiac energy metabolism and increased myocardial mass in Fabry patients. We therefore assessed possible disturbances of cardiac energy metabolism in Fabry patients by in vivo (31)P-MR-spectroscopy. Additionally, the effect of enzyme replacement therapy (ERT) on cardiac energetics was tested. Twenty-three patients (41 ± 9 years; 10 females) with genetically proven Fabry disease were examined with a 1.5 T Scanner, and compared with an age-matched healthy control group. Eight patients underwent ERT and had follow-up examinations after 3 and 14 months. The high-energy phosphate molecules phosphocreatine (PCr) and adenosine triphosphate (ATP) were quantified in localized 31P-spectra by SLOOP (spectral localization with optimum point spread function). Cine- and late gadolinium enhancement (LGE) studies were also performed. When compared with healthy controls, Fabry patients demonstrated reduced PCr- (6.1 ± 1.9 vs. 8.8 ± 2.6 mmol/kg; P = 0.003) and ATP concentrations (3.9 ± 1.5 vs. 4.6 ± 1.0 mmol/kg; P = 0.048). During ERT, PCr concentrations increased (7.1 ± 1.5 mmol/kg vs. 6.1 ± 1.9; P < 0.05) and left ventricular mass decreased (215 ± 55 vs. 185 ± 45 g; P = 0.012). Disturbances in cardiac energetics were not correlated to the presence or absence of cardiac fibrosis on LGE. Cardiac energy metabolism is disturbed in Fabry disease; this may play an important role in the pathogenesis of Fabry cardiomyopathy. Enzyme replacement therapy ameliorates energetic depression.

  12. Fabry disease and enzyme replacement therapy in classic patients with same mutation: different formulations--different outcome?

    PubMed

    Politei, J; Schenone, A B; Cabrera, G; Heguilen, R; Szlago, M

    2016-01-01

    We describe the results of the multidisciplinary evaluation in patients with Fabry disease and the same genetic mutation and their outcomes using different approved enzyme replacement therapy (ERT). We measured baseline data and serial results of neuropathic pain assessment and renal, cardiac and cerebrovascular functioning. Pain scale showed improvement in all male cases treated with agalsidasa beta. A mild improvement was detected in agalsidasa alfa-treated patients after 1 year with posterior increase. During the agalsidase beta shortage, two male patients were switched to agalsidasa alfa, after 1 year both cases presented an increase in scale values. Renal evolution showed a tendency toward a decrease in proteinuria in patients using agalsidase beta and worsening with agalsidase alfa. We found improvement in two females using agalsidase beta and no changes in the other cases regarding cardiac functioning. Brain magnetic resonance imaging (MRI) showed increase of white matter lesions in four patients. Improvement and stabilization in neuropathic pain, renal and cardiac functioning and brain MRI were found mainly in patients treated with agalsidase beta. Following the reported recommendations on reintroduction of agalsidase beta after the enzyme shortage, we decided to switch all patients to agalsidase beta. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Clinical observations on enzyme replacement therapy in patients with Fabry disease and the switch from agalsidase beta to agalsidase alfa.

    PubMed

    Lin, Hsiang-Yu; Huang, Yu-Hsiu; Liao, Hsuan-Chieh; Liu, Hao-Chuan; Hsu, Ting-Rong; Shen, Chia-I; Li, Shao-Tzu; Li, Cheng-Fang; Lee, Li-Hong; Lee, Pi-Chang; Huang, Chun-Kai; Chiang, Chuan-Chi; Lin, Shuan-Pei; Niu, Dau-Ming

    2014-04-01

    Fabry disease is an X-linked inherited lysosomal storage disease that can be treated with the enzymes of agalsidase beta (Fabrazyme) and agalsidase alfa (Replagal). Since June 2009, viral contamination of Genzyme's production facility has resulted in a worldwide shortage of agalsidase beta, leading to the switch to agalsidase alfa for patients with Fabry disease in Taiwan. The medical records were retrospectively reviewed for nine male patients with Fabry disease from the start of agalsidase beta treatment until the switch to agalsidase alfa for at least 1 year. After 12-112 months of enzyme replacement therapy (ERT), decreased plasma globotriaosylsphingosine (lyso-Gb3) was found in five out of seven patients, indicating improvement in disease severity. Among the six patients with available echocardiographic data at baseline and after ERT, all six experienced reductions of left ventricular mass index. Renal function, including microalbuminuria and estimated glomerular filtration rate, showed stability after ERT. Mainz Severity Score Index scores revealed that all nine patients remained stable at 12 months after switching to agalsidase alfa. ERT improved or stabilized cardiac status and stabilized renal function, while reducing plasma lyso-Gb3. ERT was well tolerated, even among the three patients who had hypersensitivity reactions. The switch of ERT from agalsidase beta to agalsidase alfa appears to be safe after 1 year of follow-up for Taiwanese patients with Fabry disease. Copyright © 2013. Published by Elsevier B.V.

  14. Ten-year outcome of enzyme replacement therapy with agalsidase beta in patients with Fabry disease.

    PubMed

    Germain, Dominique P; Charrow, Joel; Desnick, Robert J; Guffon, Nathalie; Kempf, Judy; Lachmann, Robin H; Lemay, Roberta; Linthorst, Gabor E; Packman, Seymour; Scott, C Ronald; Waldek, Stephen; Warnock, David G; Weinreb, Neal J; Wilcox, William R

    2015-05-01

    Fabry disease results from deficient α-galactosidase A activity and globotriaosylceramide accumulation causing renal insufficiency, strokes, hypertrophic cardiomyopathy and early demise. We assessed the 10-year outcome of recombinant α-galactosidase A therapy. The outcomes (severe clinical events, renal function, cardiac structure) of 52/58 patients with classic Fabry disease from the phase 3 clinical trial and extension study, and the Fabry Registry were evaluated. Disease progression rates for patients with low renal involvement (LRI, n=32) or high renal involvement (HRI, n=20) at baseline were assessed. 81% of patients (42/52) did not experience any severe clinical event during the treatment interval and 94% (49/52) were alive at the end of the study period. Ten patients reported a total of 16 events. Patients classified as LRI started therapy 13 years younger than HRI (mean 25 years vs 38 years). Mean slopes for estimated glomerular filtration rate for LRI and HRI were -1.89 mL/min/1.73 m(2)/year and -6.82 mL/min/1.73 m(2)/year, respectively. Overall, the mean left ventricular posterior wall thickness and interventricular septum thickness remained unchanged and normal. Patients who initiated treatment at age ≥ 40 years exhibited significant increase in left ventricular posterior wall thickness and interventricular septum thickness. Mean plasma globotriaosylceramide normalised within 6 months. This 10-year study documents the effectiveness of agalsidase beta (1 mg/kg/2 weeks) in patients with Fabry disease. Most patients remained alive and event-free. Patients who initiated treatment at a younger age and with less kidney involvement benefited the most from therapy. Patients who initiated treatment at older ages and/or had advanced renal disease experienced disease progression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. Ten-year outcome of enzyme replacement therapy with agalsidase beta in patients with Fabry disease

    PubMed Central

    Germain, Dominique P; Charrow, Joel; Desnick, Robert J; Guffon, Nathalie; Kempf, Judy; Lachmann, Robin H; Lemay, Roberta; Linthorst, Gabor E; Packman, Seymour; Scott, C Ronald; Waldek, Stephen; Warnock, David G; Weinreb, Neal J; Wilcox, William R

    2015-01-01

    Background Fabry disease results from deficient α-galactosidase A activity and globotriaosylceramide accumulation causing renal insufficiency, strokes, hypertrophic cardiomyopathy and early demise. We assessed the 10-year outcome of recombinant α-galactosidase A therapy. Methods The outcomes (severe clinical events, renal function, cardiac structure) of 52/58 patients with classic Fabry disease from the phase 3 clinical trial and extension study, and the Fabry Registry were evaluated. Disease progression rates for patients with low renal involvement (LRI, n=32) or high renal involvement (HRI, n=20) at baseline were assessed. Results 81% of patients (42/52) did not experience any severe clinical event during the treatment interval and 94% (49/52) were alive at the end of the study period. Ten patients reported a total of 16 events. Patients classified as LRI started therapy 13 years younger than HRI (mean 25 years vs 38 years). Mean slopes for estimated glomerular filtration rate for LRI and HRI were −1.89 mL/min/1.73 m2/year and −6.82 mL/min/1.73 m2/year, respectively. Overall, the mean left ventricular posterior wall thickness and interventricular septum thickness remained unchanged and normal. Patients who initiated treatment at age ≥40 years exhibited significant increase in left ventricular posterior wall thickness and interventricular septum thickness. Mean plasma globotriaosylceramide normalised within 6 months. Conclusions This 10-year study documents the effectiveness of agalsidase beta (1 mg/kg/2 weeks) in patients with Fabry disease. Most patients remained alive and event-free. Patients who initiated treatment at a younger age and with less kidney involvement benefited the most from therapy. Patients who initiated treatment at older ages and/or had advanced renal disease experienced disease progression. PMID:25795794

  16. A budesonide prodrug accelerates treatment of colitis in rats.

    PubMed Central

    Cui, N; Friend, D R; Fedorak, R N

    1994-01-01

    Although oral glucocorticoids are the treatment of choice for moderate to severe ulcerative pancolitis, their systemic side effects and adrenal suppression account for considerable morbidity. An oral glucocorticoid-conjugate (prodrug), budesonide-beta-D-glucuronide, which is not absorbed in the small intestine but is hydrolysed by colonic bacterial and mucosal beta-glucuronidase to release free budesonide into the colon was synthesised. The objective of this study was to compare treatment with budesonide-beta-D-glucuronide with treatment with free budesonide by examining: (1) the healing of experimental colitis and (2) the extent of adrenal suppression. Pancolitis was induced with 4% acetic acid. Animals were then randomised to receive oral therapy for 72 hours with (1) budesonide-beta-D-glucuronide, (2) free budesonide, or (3) vehicle. Drug efficacy and colitic healing was determined by measuring gross colonic ulceration, myeloperoxidase activity, and in vivo colonic fluid absorption. Adrenal suppression was determined by measuring plasma adrenocorticotrophic hormone and serum corticosterone. Vehicle-treated colitis animals had gross ulceration, increased myeloperoxidase activity, and net colonic fluid secretion. Treatment with oral budesonide-beta-D-glucuronide accelerated all measures of colitis healing at a fourfold lower dose than did free budesonide. Furthermore, treatment with budesonide-beta-D-glucuronide did not result in adrenal suppression whereas free budesonide treatment did. A newly synthesised orally administered glucocorticoid-conjugate accelerates colitis healing with limited adrenal suppression. Development of an orally administered colon-specific steroid delivery system represents a novel approach to inflammatory bowel disease treatment. PMID:7959202

  17. Computational modeling and in-vitro/in-silico correlation of phospholipid-based prodrugs for targeted drug delivery in inflammatory bowel disease

    NASA Astrophysics Data System (ADS)

    Dahan, Arik; Markovic, Milica; Keinan, Shahar; Kurnikov, Igor; Aponick, Aaron; Zimmermann, Ellen M.; Ben-Shabat, Shimon

    2017-11-01

    Targeting drugs to the inflamed intestinal tissue(s) represents a major advancement in the treatment of inflammatory bowel disease (IBD). In this work we present a powerful in-silico modeling approach to guide the molecular design of novel prodrugs targeting the enzyme PLA2, which is overexpressed in the inflamed tissues of IBD patients. The prodrug consists of the drug moiety bound to the sn-2 position of phospholipid (PL) through a carbonic linker, aiming to allow PLA2 to release the free drug. The linker length dictates the affinity of the PL-drug conjugate to PLA2, and the optimal linker will enable maximal PLA2-mediated activation. Thermodynamic integration and Weighted Histogram Analysis Method (WHAM)/Umbrella Sampling method were used to compute the changes in PLA2 transition state binding free energy of the prodrug molecule (ΔΔGtr) associated with decreasing/increasing linker length. The simulations revealed that 6-carbons linker is the optimal one, whereas shorter or longer linkers resulted in decreased PLA2-mediated activation. These in-silico results were shown to be in excellent correlation with experimental in-vitro data. Overall, this modern computational approach enables optimization of the molecular design of novel prodrugs, which may allow targeting the free drug specifically to the diseased intestinal tissue of IBD patients.

  18. Timing of initiation of enzyme replacement therapy after diagnosis of type 1 Gaucher disease: effect on incidence of avascular necrosis

    PubMed Central

    Mistry, Pramod K; Deegan, Patrick; Vellodi, Ashok; Cole, J Alexander; Yeh, Michael; Weinreb, Neal J

    2009-01-01

    Data from the International Collaborative Gaucher Group Gaucher Registry were analysed to assess the relationship between enzyme replacement therapy with imiglucerase (ERT) and incidence of avascular necrosis (AVN) in type 1 Gaucher disease (GD1), and to determine whether the time interval between diagnosis and initiation of ERT influences the incidence rate of AVN. All patients with GD1 enrolled in the Gaucher Registry who received ERT and did not report AVN prior to starting therapy (n = 2700) were included. The incidence rate of AVN following initiation of ERT was determined. An incidence rate of AVN of 13·8 per 1000 person-years was observed in patients receiving ERT. Patients who initiated ERT within 2 years of diagnosis had an incidence rate of 8·1 per 1000 person-years; patients who started ERT ≥2 years after diagnosis had an incidence rate of 16·6 per 1000 person-years. The adjusted incidence rate ratio was 0·59 [95% confidence interval (CI) 0·36–0·96, P = 0·0343]. Splenectomy was an independent risk factor for AVN (adjusted incidence rate ratio 2·23, 95% CI 1·61–3·08, P < 0·0001). In conclusion, the risk of AVN was reduced among patients who initiated ERT within 2 years of diagnosis, compared to initiating treatment ≥2 years after diagnosis. A higher risk of AVN was observed among patients who had previously undergone splenectomy. PMID:19732054

  19. The impact of the immune system on the safety and efficiency of enzyme replacement therapy in lysosomal storage disorders.

    PubMed

    Broomfield, A; Jones, S A; Hughes, S M; Bigger, B W

    2016-07-01

    In the light of clinical experience in infantile onset Pompe patients, the immunological impact on the tolerability and long-term efficacy of enzyme replacement therapy (ERT) for lysosomal storage disorders has come under renewed scrutiny. This article details the currently proposed immunological mechanisms involved in the development of anti-drug antibodies and the current therapies used in their treatment. Given the current understanding of the adaptive immune response, it focuses particularly on T cell dependent mechanisms and the paradigm of using lymphocytic negative selection as a predictor of antibody formation. This concept originally postulated in the 1970s, stipulated that the genotypically determined lack of production or production of a variant protein determines an individual's lymphocytic repertoire. This in turn is the key factor in determining the potential severity of an individual's immunological response to ERT. It also highlights the need for immunological assay standardization particularly those looking at describing the degree of functional impact, robust biochemical or clinical endpoints and detailed patient subgroup identification if the true evaluations of impact are to be realised.

  20. Synthesis of pro-prodrugs L-lysine based for 5-aminosalicylic acid and 6-mercaptopurine colon specific release.

    PubMed

    Trombino, Sonia; Cassano, Roberta; Cilea, Alessia; Ferrarelli, Teresa; Muzzalupo, Rita; Picci, Nevio

    2011-11-28

    The aim of this work is to design, prepare and characterize L-lysine based prodrugs capable of targeting 6-mercaptopurine to the colon, an anti-tumor and immunosuppressant drug, and 5-aminosalicylic acid (5-ASA), drug of choice for inflammatory bowel disease (IBD). More specifically, Nɛ-feruloyl-S-(6-purinyl)-L-lysine and Nɛ-acryloyl-S-(6-purinyl)-L-lysine were synthesized and then characterized by FT-IR, (1)H-NMR and GC/MS spectroscopies. The ability of feruloyl derivative in inhibiting lipid peroxidation in rat liver microsomal membranes, induced in vitro by tert-butyl hydroperoxide as source of free radicals, was evaluated. Moreover, Nɛ-acryloyl-S-(6-purinyl)-L-lysine, polymerizable prodrug, was used to microspheres realization for 5-ASA release. These lasts, obtained by emulsion inverse technique, were characterized by light scattering and scanning electron microscopy (SEM) analysis. The microspheres equilibrium swelling degree was evaluated and showed good swelling behaviour in simulating colonic fluids. Results confirm the possibility that the application range of L-lysine prodrug can be extended to the treatment of intestinal diseases whose conventional therapy envisages medications with serious side effects that, thanks to this new strategy, can be minimized in an optimal way. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Amphiphilic curcumin conjugate-forming nanoparticles as anticancer prodrug and drug carriers: in vitro and in vivo effects.

    PubMed

    Tang, Huadong; Murphy, Caitlin J; Zhang, Bo; Shen, Youqing; Sui, Meihua; Van Kirk, Edward Alva; Feng, Xiaowen; Murdoch, William J

    2010-08-01

    Curcumin has been shown to have high cytotoxicity towards various cancer cell lines, but its water insolubility and instability make its bioavailability exceedingly low and, thus, it is generally inactive in in vivo anticancer tests. Here, we report an intracellular-labile amphiphilic surfactant-like curcumin prodrug--curcumin conjugated with two short oligo(ethylene glycol) (Curc-OEG) chains via beta-thioester bonds that are labile in the presence of intracellular glutathione and esterase. Curc-OEG formed stable nanoparticles in aqueous conditions and served two roles--as an anticancer prodrug and a drug carrier. As an anticancer prodrug, the formed nanoparticles had a high and fixed curcumin-loading content of 25.3 wt%, and released active curcumin in the intracellular environment. Curc-OEG had high inhibition ability to several cancer cell lines due to apoptosis. Intravenously injected Curc-OEG significantly reduced the tumor weights and tumor numbers in the athymic mice xenografted with intraperitoneal SKOV-3 tumors and subcutaneous (mammary fat pad) MDA-MB-468 tumors. Preliminary systemic toxicity studies found that Curc-OEG did not cause acute and subchronic toxicities to mouse visceral organs at high doses. As drug carriers, Curc-OEG nanoparticles could carry other anticancer drugs, such as doxorubicin and camptothecin, and ship them into drug-resistant cells, greatly enhancing the cytotoxicity of the loaded drug. Thus, Curc-OEG is a promising prototype that merits further study for cancer therapy.

  2. Esterase-sensitive prodrugs with tunable release rates and direct generation of hydrogen sulfidea

    PubMed Central

    Zheng, Yueqin; Yu, Bingchen; Ji, Kaili; Pan, Zhixiang; Chittavong, Vayou

    2016-01-01

    Prodrugs that release hydrogen sulfide upon esterase-mediated cleavage of an ester group followed by lactonization are described herein. By modifying the ester group and thus its susceptibility to esterase, and structural features critical to the lactonization rate, H2S release rates can be tuned. Such prodrugs directly release hydrogen sulfide without the involvement of perthiol species, which are commonly encountered with existing H2S donors. Additionally, such prodrugs can easily be conjugated to another non-steroidal anti-inflammatory agent, leading to easy synthesis of hybrid prodrugs. As a biological validation of the H2S prodrugs, the anti-inflammatory effects of one such prodrug were examined by studying its ability to inhibit LPS-induced TNF-α production in RAW 264.7 cells. This type of H2S prodrugs shows great potential as both research tools and therapeutic agents. PMID:26822005

  3. Bioactivation antioxidant and transglycating properties of N-acetylcarnosine autoinduction prodrug of a dipeptide L-carnosine in mucoadhesive drug delivery eye-drop formulation: powerful eye health application technique and therapeutic platform.

    PubMed

    Babizhayev, Mark A

    2012-06-01

    A considerable interest in N-acetylcarnosine ocular drug design for eye health is based on clinical strategies to improve ocular drug delivery through metabolic enzymatic activation. Human biology aspects of ocular N-acetylcarnosine deacetylation during its pass through the cornea to the aqueous humor and dipeptide hydrolyzing enzymes are characterized. Novel approaches to ocular drug delivery increasing intraocular bioavailability of N-acetylcarnosine biologically activated metabolite carnosine become an integral development ensuring prolonged retention of the medication in the mucoadhesive precorneal area and facilitating transcorneal penetration of the natural dipeptide with the corneal promoters. A comprehensive list of techniques for peptide drug design, synthesis, purification, and biological analyses was considered: liquid chromatography (LC), high performance liquid chromatography (HPLC), (1) H and (13) C nuclear magnetic resonance (NMR), electrospray ionization (ESI) mass spectroscopy, and spectrophotometry. The antioxidant activity of therapeutics-targeted molecules was studied in aqueous solution and in a lipid membrane environment. A deglycation therapeutic system was developed involving removal, by transglycation of sugar or aldehyde moieties from Schiff bases by histidyl-hydrazide compounds or aldehyde scavenger L-carnosine. Clinical studies included ophthalmoscopy, visual acuity (VA), halometer disability glare tests, slit-image, and retro-illumination photography. N-acetylcarnosine 1% lubricant eye drops are considered as an auto-induction prodrug and natural ocular redox state balance therapies with implications in prevention and treatment of serious eye diseases that involve pathways of continuous oxidative damage to ocular tissues(cataracts, primary open-angle glaucoma, age-related macular degeneration) and sight-threatening glycosylation processes (diabetic retinopathy and consequent visual impairment) important for public health. The results of

  4. Enzyme responsive drug delivery system based on mesoporous silica nanoparticles for tumor therapy in vivo

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Ding, Xingwei; Li, Jinghua; Luo, Zhong; Hu, Yan; Liu, Junjie; Dai, Liangliang; Zhou, Jun; Hou, Changjun; Cai, Kaiyong

    2015-04-01

    To reduce the toxic side effects of traditional chemotherapeutics in vivo, we designed and constructed a biocompatible, matrix metalloproteinases (MMPs) responsive drug delivery system based on mesoporous silica nanoparticles (MSNs). MMPs substrate peptide containing PLGLAR (sensitive to MMPs) was immobilized onto the surfaces of amino-functionalized MSNs via an amidation reaction, serving as MMPs sensitive intermediate linker. Bovine serum albumin was then covalently coupled to linker as end-cap for sealing the mesopores of MSNs. Lactobionic acid was further conjugated to the system as targeting motif. Doxorubicin hydrochloride was used as the model anticancer drug in this study. A series of characterizations revealed that the system was successfully constructed. The peptide-functionalized MSNs system demonstrated relatively high sensitivity to MMPs for triggering drug delivery, which was potentially important for tumor therapy since the tumor’s microenvironment overexpressed MMPs in nature. The in vivo experiments proved that the system could efficiently inhibit the tumor growth with minimal side effects. This study provides an approach for the development of the next generation of nanotherapeutics toward efficient cancer treatment.

  5. Intrathecal enzyme replacement therapy reduces lysosomal storage in the brain and meninges of the canine model of MPS I.

    PubMed

    Kakkis, E; McEntee, M; Vogler, C; Le, S; Levy, B; Belichenko, P; Mobley, W; Dickson, P; Hanson, S; Passage, M

    2004-01-01

    Enzyme replacement therapy (ERT) has been developed for several lysosomal storage disorders, including mucopolysaccharidosis I (MPS I), and is effective at reducing lysosomal storage in many tissues and in ameliorating clinical disease. However, intravenous ERT does not adequately treat storage disease in the central nervous system (CNS), presumably due to effects of the blood-brain barrier on enzyme distribution. To circumvent this barrier, we studied whether intrathecal (IT) recombinant human alpha-L-iduronidase (rhIDU) could penetrate and treat the brain and meninges. An initial dose-response study showed that doses of 0.46-4.14 mg of IT rhIDU successfully penetrated the brain of normal dogs and reached tissue levels 5.6 to 18.9-fold normal overall and 2.7 to 5.9-fold normal in deep brain sections lacking CSF contact. To assess the efficacy and safety in treating lysosomal storage disease, four weekly doses of approximately 1 mg of IT rhIDU were administered to MPS I-affected dogs resulting in a mean 23- and 300-fold normal levels of iduronidase in total brain and meninges, respectively. Quantitative glycosaminoglycan (GAG) analysis showed that the IT treatment reduced mean total brain GAG to normal levels and achieved a 57% reduction in meningeal GAG levels accompanied by histologic improvement in lysosomal storage in all cell types. The dogs did develop a dose-dependent immune response against the recombinant human protein and a meningeal lymphocytic/plasmacytic infiltrate. The IT route of ERT administration may be an effective way to treat the CNS disease in MPS I and could be applicable to other lysosomal storage disorders.

  6. Simvastatin Prodrug Micelles Target Fracture and Improve Healing

    PubMed Central

    Dusad, Anand; Yuan, Hongjiang; Ren, Ke; Li, Fei; Fehringer, Edward V.; Purdue, P. Edward; Goldring, Steven R.; Daluiski, Aaron; Wang, Dong

    2014-01-01

    Simvastatin (SIM), a widely used anti-lipidaemic drug, has been identified as a bone anabolic agent. Its poor water solubility and the lack of distribution to the skeleton, however, have limited its application in the treatment of bone metabolic diseases. In this study, an amphiphilic macromolecular prodrug of SIM was designed and synthesized to overcome these limitations. The polyethylene glycol (PEG)-based prodrug can spontaneously self-assemble to form micelles. The use of SIM trimer as the prodrug’s hydrophobic segment allows easy encapsulation of additional free SIM. The in vitro studies showed that SIM/SIM-mPEG micelles were internalized by MC3T3 cells via lysosomal trafficking and consistently induced expression of both BMP2 and DKK1 mRNA, suggesting that the prodrug micelle retains the biological functions of SIM. After systemic administration, optical imaging suggests that the micelles would passively target to bone fracture sites associated with hematoma and inflammation. Furthermore, flow cytometry study revealed that SIM/SIM-mPEG micelles had preferred cellular uptake by inflammatory and resident cells within the fracture callus tissue. The treatment study using a mouse osteotomy model validated the micelles’ therapeutic efficacy in promoting bone fracture healing as demonstrated by micro-CT and histological analyses. Collectively, these data suggest that the macromolecular prodrug-based micelle formulation of SIM may have great potential for clinical management of impaired fracture healing. PMID:25542644

  7. Evaluation of diclofenac prodrugs for enhancing transdermal delivery.

    PubMed

    Lobo, Shabbir; Li, Henan; Farhan, Nashid; Yan, Guang

    2014-03-01

    Abstract Objective: The purpose of this study was to evaluate the approach of using diclofenac acid (DA) prodrugs for enhancing transdermal delivery. Methanol diclofenac ester (MD), ethylene glycol diclofenac ester (ED), glycerol diclofenac ester (GD) and 1,3-propylene glycol diclofenac ester (PD) were synthesized and evaluated for their physicochemical properties such as solubilities, octanol/water partition coefficients, stratum corneum/water partition coefficients, hydrolysis rates and bioconversion rates. In vitro fluxes across human epidermal membrane (HEM) in the Franz diffusion cell were determined on DA-, MD-, ED-, GD- and PD-saturated aqueous solutions. The formation of GD and ED led to the prodrugs with higher aqueous solubilities and lower partition coefficients than those of the parent drug. Prodrugs with improved aqueous solubility showed better fluxes across HEM in aqueous solution than that of the parent drug, with GD showing the highest aqueous solubility and also the highest flux. There is a linear relationship between the aqueous solubility and flux for DA, ED and PD, but GD and MD deviated from the linear line. Diclofenac prodrugs with improved hydrophilicity than the parent drug could be utilized for enhancing transdermal diclofenac delivery.

  8. Reduction of Plasma Globotriaosylsphingosine Levels After Switching from Agalsidase Alfa to Agalsidase Beta as Enzyme Replacement Therapy for Fabry Disease.

    PubMed

    Goker-Alpan, Ozlem; Gambello, Michael J; Maegawa, Gustavo H B; Nedd, Khan J; Gruskin, Daniel J; Blankstein, Larry; Weinreb, Neal J

    2016-01-01

    Agalsidase alfa and agalsidase beta, recombinant enzyme preparations for treatment of Fabry disease (FD), have different approved dosing schedules: 0.2 mg/kg and 1.0 mg/kg every other week (EOW), respectively. This open-label, multicenter, exploratory phase 4 study evaluated plasma globotriaosylsphingosine (lyso-GL-3) and plasma and urine globotriaosylceramide (GL-3) levels at baseline and 2, 4, and 6 months after the switch from agalsidase alfa (0.2 mg/kg EOW for ≥12 months) to agalsidase beta (1.0 mg/kg EOW) in 15 male patients with FD. Immunoglobulin (Ig)G antidrug antibody titers were assessed, and safety was monitored throughout the study. Plasma lyso-GL-3 concentrations decreased significantly within 2 months after switch and reductions continued through month 6 (mean absolute changes, -12.8, -16.1, and -16.7 ng/mL at 2, 4, and 6 months, respectively; all P < 0.001). The mean percentage reduction from baseline was 39.5% (P < 0.001) at month 6. For plasma GL-3, the mean absolute change from baseline (-0.9 μg/mL) and percentage reduction (17.9%) at month 6 were both significant (P < 0.05). Urine GL-3 measurements showed intra-patient variability and changes from baseline were not significant. No clinical outcomes were assessed in this 6-month study, and, therefore, no conclusions can be drawn regarding the correlation of observed reductions in glycosphingolipid concentrations with clinically relevant outcomes. There were no differences in IgG antidrug antibody titers between the two enzymes. The switch from agalsidase alfa to agalsidase beta was well tolerated. Plasma lyso-GL-3 and GL-3 levels reduced after switching from agalsidase alfa to agalsidase beta, indicating that agalsidase beta has a greater pharmacodynamic effect on these markers at the recommended dose. These data further support the use of agalsidase beta 1.0 mg/kg EOW as enzyme replacement therapy in FD.

  9. Fabry disease under enzyme replacement therapy-new insights in efficacy of different dosages.

    PubMed

    Krämer, Johannes; Lenders, Malte; Canaan-Kühl, Sima; Nordbeck, Peter; Üçeyler, Nurcan; Blaschke, Daniela; Duning, Thomas; Reiermann, Stefanie; Stypmann, Jörg; Brand, Stefan-Martin; Gottschling, Timo; Störk, Stefan; Wanner, Christoph; Sommer, Claudia; Brand, Eva; Weidemann, Frank

    2017-11-23

    Fabry patients on reduced dose of agalsidase-beta or after switch to agalsidase-alfa show a decline in estimated glomerular filtration rate (eGFR) and an increase of the Mainz Severity Score Index. In this prospective observational study, we assessed end-organ damage and clinical symptoms in 112 patients who had received agalsidase-beta (1.0 mg/kg) for >1 year, who were (i) non-randomly assigned to continue this treatment regime (regular-dose group, n = 37); (ii) received a reduced dose of agalsidase-beta and subsequent switch to agalsidase-alfa (0.2 mg/kg) or a direct switch to 0.2 mg/kg agalsidase-alfa (switch group, n = 38); or (iii) were re-switched to agalsidase-beta after receiving agalsidase-alfa for at least 12 months (re-switch group, n = 37) with a median follow-up of 53 (38-57) months. eGFR of patients in the regular-dose group remained stable. Patients in the switch group showed an annual eGFR loss of - 4.6  ±  9.1 mL/min/1.73 m2 (P < 0.05). Patients in the re-switch group also had an eGFR loss of - 2.2  ±  4.4 mL/min/1.73 m2 after re-switch to agalsidase-beta, but to a lower degree compared with the switch group (P < 0.05). Patients in the re-switch group suffered less frequently from diarrhoea (relative risk 0.42; 95% confidence interval 0.19-0.93; P = 0.02). Lyso-Gb3 remained stable in the switch (P = 0.97) and the regular-dose (P = 0.48) groups, but decreased in the re-switch group after change of the therapy regimen (P < 0.05). After switch to agalsidase-alfa, Fabry patients experienced a continuous decline in eGFR, while this decline was attenuated in patients who were re-switched to agalsidase-beta. Decreasing lyso-Gb3 levels may indicate a better treatment response in the latter group. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  10. Expensive drugs for rare disorders: to treat or not to treat? The case of enzyme replacement therapy for mucopolysaccharidosis VI.

    PubMed

    Schlander, M; Beck, M

    2009-05-01

    Mucopolysaccharidosis VI (MPS VI) is a very rare, chronically debilitating lysosomal storage disorder that develops in people with an enzyme deficiency. Clinical characteristics and progression rates vary widely between patients. The recent introduction of enzyme replacement therapy (ERT) has improved considerably the lives of patients with MPS VI, at an annual cost of treatment between euro 150,000 and euro 450,000 per patient. This Commentary article addresses the controversial topic of granting reimbursement for expensive treatment options for orphan diseases, such as MPS VI. The discussion reflects clinical, economic and ethical aspects and incorporates insights from the relevant literature (based on a Medline search to September 2008) on MPS VI, efficacy of ERT, orphan drugs, and the economics and ethics of health-care prioritisation. Although ERT for MPS VI received marketing authorisation in the European Union in January 2006, patients' access to this therapy varies geographically due to differences between national reimbursement schemes for orphan drugs. Some inclusion and exclusion criteria for treatment of MPS VI patients with ERT appear arbitrary and may contribute to the exclusion from treatment of patients who could benefit in the long term. Reimbursement schemes which rely on proof of short-term treatment effectiveness may discriminate against slowly progressive patients, as health gain can often not be confirmed over a short period of time in these patients. Conventional cost-effectiveness analysis remains silent on crucial issues related to budgetary impact, i.e. opportunity cost from a system perspective, and fair access to treatment. To prevent patients from being deprived of effective treatment, it is suggested that inclusion and exclusion criteria for treatment should be primarily based on a careful individual assessment of expected long-term clinical benefits. Once treatment has been agreed to as the correct option on clinical grounds, it is

  11. Clickable prodrugs bearing potent and hydrolytically cleavable nicotinamide phosphoribosyltransferase inhibitors.

    PubMed

    Sadrerafi, Keivan; Mason, Emilia O; Lee, Mark W

    2018-01-01

    Our previous study indicated that carborane containing small-molecule 1-(hydroxymethyl)-7-(4'-( trans -3″-(3'″-pyridyl)acrylamido)butyl)-1,7-dicarbadodecaborane (hm-MC4-PPEA), was a potent inhibitor of nicotinamide phosphoribosyltransferase (Nampt). Nampt has been shown to be upregulated in most cancers and is a promising target for the treatment of many different types of cancers, including breast cancers. To increase the selectivity of hm-MC4-PPEA toward cancer cells, three prodrugs were synthesized with different hydrolyzable linkers: ester, carbonate, and carbamate. Using click chemistry a fluorophore was attached to these prodrugs to act as a model for our conjugation strategy and to serve as an aid for prodrug stability studies. The stabilities of these drug conjugates were tested in phosphate-buffered saline (PBS) at normothermia (37°C) using three different pH levels, 5.5, 7.5, and 9.5, as well as in horse serum at physiological pH. The stability of each was monitored using reversed-phase HPLC equipped with both diode array and fluorescence detection. The inhibitory activity of hm-MC4-PPEA was also measured using a commercially available colorimetric assay. The biological activities of the drug conjugates as well as those of the free drug (hm-MC4-PPEA), were evaluated using the MTT assay against the human breast cancer cell lines T47D and MCF7, as well as the noncancerous, transformed, Nampt-dependent human breast epithelium cell line 184A1. hm-MC4-PPEA showed to be a potent inhibitor of recombinant Nampt activity, exhibiting an IC50 concentration of 6.8 nM. The prodrugs showed great stability towards hydrolytic degradation under neutral, mildly acidic and mildly basic conditions. The carbamate prodrug also showed to be stable in rat serum. However, the carbonate and the ester prodrug release at various rates in serum presumably owing to the presence of several different classes of esterase. The biological activities of the drug conjugates correlate

  12. Transporter targeted gatifloxacin prodrugs: synthesis, permeability, and topical ocular delivery.

    PubMed

    Vooturi, Sunil K; Kadam, Rajendra S; Kompella, Uday B

    2012-11-05

    In this work, we aim to design and synthesize prodrugs of gatifloxacin targeting organic cation transporter (OCT), monocarboxylate transporter (MCT), and ATB (0, +) transporters and to identify a prodrug with enhanced delivery to the back of the eye. Dimethylamino-propyl, carboxy-propyl, and amino-propyl(2-methyl) derivatives of gatifloxacin (GFX), DMAP-GFX, CP-GFX, and APM-GFX, were designed and synthesized to target OCT, MCT, and ATB (0, +) transporters, respectively. An LC-MS method was developed to analyze drug and prodrug levels in various studies. Solubility and log D (pH 7.4) were measured for prodrugs and the parent drug. The permeability of the prodrugs was determined in the cornea, conjunctiva, and sclera-choroid-retinal pigment epitheluim (SCRPE) and compared with gatifloxacin using an Ussing chamber assembly. Permeability mechanisms were elucidated by determining the transport in the presence of transporter specific inhibitors. 1-Methyl-4-phenylpyridinium iodide (MPP+), nicotinic acid sodium salt, and α-methyl-DL-tryptophan were used to inhibit OCT, MCT, and ATB (0, +) transporters, respectively. A prodrug selected based on in vitro studies was administered as an eye drop to pigmented rabbits, and the delivery to various eye tissues including vitreous humor was compared with gatifloxacin dosing. DMAP-GFX exhibited 12.8-fold greater solubility than GFX. All prodrugs were more lipophilic, with the measured log D (pH 7.4) values ranging from 0.05 to 1.04, when compared to GFX (log D: -1.15). DMAP-GFX showed 1.4-, 1.8-, and 1.9-fold improvement in permeability across the cornea, conjunctiva, and SCRPE when compared to GFX. Moreover, it exhibited reduced permeability in the presence of MPP+ (competitive inhibitor of OCT), indicating OCT-mediated transport. CP-GFX showed 1.2-, 2.3-, and 2.5-fold improvement in permeability across the cornea, conjunctiva, and SCRPE, respectively. In the presence of nicotinic acid (competitive inhibitor of MCT), the

  13. Transporter targeted gatifloxacin prodrugs: Synthesis, permeability, and topical ocular delivery

    PubMed Central

    Vooturi, Sunil K.; Kadam, Rajendra S.; Kompella, Uday B.

    2013-01-01

    Purpose To design and synthesize prodrugs of gatifloxacin targeting OCT, MCT, and ATB (0, +) transporters and to identify a prodrug with enhanced delivery to the back of the eye. Method Dimethylamino-propyl, carboxy-propyl, and amino-propyl(2-methyl) derivatives of gatifloxacin (GFX), DMAP-GFX, CP-GFX, and APM-GFX, were designed and synthesized to target OCT, MCT, and ATB (0, +) transporters, respectively. LC-MS method was developed to analyze drug and prodrug levels in various studies. Solubility and Log D (pH 7.4) were measured for prodrugs and the parent drug. Permeability of the prodrugs was determined in cornea, conjunctiva, and sclera-choroidretinal pigment epitheluim (SCRPE) and compared with gatifloxacin using Ussing chamber assembly. Permeability mechanisms were elucidated by determining the transport in the presence of transporter specific inhibitors. 1-Methyl-4-phenylpyridinium iodide (MPP+), nicotinic acid sodium salt, and α-methyl-DL-tryptophan were used to inhibit OCT, MCT, and ATB (0, +) transporters, respectively. A prodrug selected based on in vitro studies was administered as an eye drop to pigmented rabbits and the delivery to various eye tissues including vitreous humor was compared with gatifloxacin dosing. Results DMAP-GFX exhibited 12.8-fold greater solubility than GFX. All prodrugs were more lipophilic, with the measured Log D (pH 7.4) values ranging from 0.05 to 1.04, when compared to GFX (Log D: -1.15). DMAP-GFX showed 1.4-, 1.8-, and 1.9-fold improvement in permeability across cornea, conjunctiva, as well as SCRPE when compared to GFX. Moreover, it exhibited reduced permeability in the presence of MPP+ (competitive inhibitor of OCT), indicating OCT-mediated transport. CP-GFX showed 1.2-, 2.3- and 2.5-fold improvement in permeability across cornea, conjunctiva and SCRPE, respectively. In the presence of nicotinic acid (competitive inhibitor of MCT), permeability of CP-GFX was reduced across conjunctiva. However, cornea and SCRPE

  14. Retroviral-mediated gene therapy for the treatment of hepatocellular carcinoma: an innovative approach for cancer therapy.

    PubMed Central

    Huber, B E; Richards, C A; Krenitsky, T A

    1991-01-01

    An approach involving retroviral-mediated gene therapy for the treatment of neoplastic disease is described. This therapeutic approach is called "virus-directed enzyme/prodrug therapy" (VDEPT). The VDEPT approach exploits the transcriptional differences between normal and neoplastic cells to achieve selective killing of neoplastic cells. We now describe development of the VDEPT approach for the treatment of hepatocellular carcinoma. Replication-defective, amphotrophic retroviruses were constructed containing a chimeric varicella-zoster virus thymidine kinase (VZV TK) gene that is transcriptionally regulated by either the hepatoma-associated alpha-fetoprotein or liver-associated albumin transcriptional regulatory sequences. Subsequent to retroviral infection, expression of VZV TK was limited to either alpha-fetoprotein- or albumin-positive cells, respectively. VZV TK metabolically activated the nontoxic prodrug 6-methoxypurine arabinonucleoside (araM), ultimately leading to the formation of the cytotoxic anabolite adenine arabinonucleoside triphosphate (araATP). Cells that selectively expressed VZV TK became selectively sensitive to araM due to the VZV TK-dependent anabolism of araM to araATP. Hence, these retroviral-delivered chimeric genes generated tissue-specific expression of VZV TK, tissue-specific anabolism of araM to araATP, and tissue-specific cytotoxicity due to araM exposure. By utilizing such retroviral vectors, araM was anabolized to araATP in hepatoma cells, producing a selective cytotoxic effect. Images PMID:1654555

  15. Legubicin a Tumor-activated Prodrug for Breast Cancer Therapy

    DTIC Science & Technology

    2008-04-01

    slides were incubated with a cocktail of first primary antibodies for overnight (biotin-conjugeted rat anti-mouse CD68 at 1:100 dilution and sheep anti... sheep (green) (Vector Laboratories) for 40 minutes. Nuclear staining was performed DEPI (10ug/ml) for 10 minutes, then mount cover slip with anti-fade

  16. Legubicin, a Tumor-Activated Prodrug for Breast Cancer Therapy

    DTIC Science & Technology

    2007-04-01

    carcinomas, leukemias, lymphomas, melanomas, fibrosarcomas , neuroblastoma, and the like. The cancer can, for example, be autoimmune deficiency syndrome...their analogs. (a) 4-Nitrophenyl chloroformate, Py, CH2Cl2, 0°C; (b) (i) OsO4 ( cat ), NMO, citric acid, CH2Cl2-H2O (10:1), RT, (ii) NaIO4, THF- H2O (1:1

  17. Toward reducing immunogenicity of enzyme replacement therapy: altering the specificity of human β-glucuronidase to compensate for α-iduronidase deficiency.

    PubMed

    Chuang, Huai-Yao; Suen, Ching-Shu; Hwang, Ming-Jing; Roffler, Steve R

    2015-11-01

    Enzyme replacement therapy (ERT) is an effective treatment for many patients with lysosomal storage disorders caused by deficiency in enzymes involved in cell metabolism. However, immune responses that develop against the administered enzyme in some patients can hinder therapeutic efficacy and cause serious side effects. Here we investigated the feasibility of a general approach to decrease ERT immunogenicity by altering the specificity of a normal endogenous enzyme to compensate for a defective enzyme. We sought to identify human β-glucuronidase variants that display α-iduronidase activity, which is defective in mucopolysaccharidosis (MPS) type I patients. A human β-glucuronidase library was screened by the Enzyme Cleavable Surface-Tethered All-purpose Screen sYstem to isolate variants that exhibited 100-290-fold greater activity against the α-iduronidase substrate 4-methylumbelliferyl α-l-iduronide and 7900-24 500-fold enzymatic specificity shift when compared with wild-type β-glucuronidase. In vitro treatment of MPS I cells with the β-glucuronidase variants significantly restored lysosome appearance similar to treatment with α-iduronidase. Our study suggests that β-glucuronidase variants can be isolated to display α-iduronidase activity and produce significant phenotype improvement of MPS I cells. This strategy may represent a possible approach to produce enzymes that display therapeutic benefits with potentially less immunogenicity. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Prognostic Importance of Early Worsening Renal Function Following Initiation of Angiotensin Converting Enzyme Inhibitor Therapy in Patients with Cardiac Dysfunction

    PubMed Central

    Testani, Jeffrey M.; Kimmel, Stephen E.; Dries, Daniel L.; Coca, Steven G.

    2011-01-01

    Background Worsening renal function (WRF) in the setting of heart failure has been associated with increased mortality. However, it is unclear if this decreased survival is a direct result of the reduction in glomerular filtration rate (GFR) or if the mechanism underlying the deterioration in GFR is driving prognosis. Given that WRF in the setting of angiotensin converting enzyme inhibitor (ACE-I) initiation is likely mechanistically distinct from spontaneously occurring WRF, we sought to investigate the relative early WRF associated mortality rates in subjects randomized to ACE-I or placebo. Methods and Results Subjects in the Studies Of Left Ventricular Dysfunction limited data set were studied (6,377 patients). The interaction between early WRF (decrease in estimated GFR ≥20% at 14 days), randomization to enalapril, and mortality was the primary endpoint. In the overall population, early WRF was associated with increased mortality (adjusted HR=1.2, 95% CI 1.0–1.4, p=0.037). When analysis was restricted to the placebo group, this association strengthened (adjusted HR=1.4, 95% CI 1.1–1.8, p=0.004). However, in the enalapril group, early WRF had no adverse prognostic significance (adjusted HR=1.0, 95% CI 0.8–1.3, p=1.0, p interaction=0.09). In patients that continued study drug despite early WRF, a survival advantage remained with enalapril therapy (adjusted HR=0.66, 95% CI 0.5–0.9, p=0.018). Conclusions These data support the notion that the mechanism underlying WRF is important in determining its prognostic significance. Specifically, early WRF in the setting of ACE-I initiation appears to represent a benign event which is not associated with a loss of benefit from continued ACE-I therapy. PMID:21903907

  19. Metformin and Its Sulfenamide Prodrugs Inhibit Human Cholinesterase Activity.

    PubMed

    Markowicz-Piasecka, Magdalena; Sikora, Joanna; Mateusiak, Łukasz; Mikiciuk-Olasik, Elżbieta; Huttunen, Kristiina M

    2017-01-01

    The results of epidemiological and pathophysiological studies suggest that type 2 diabetes mellitus (T2DM) may predispose to Alzheimer's disease (AD). The two conditions present similar glucose levels, insulin resistance, and biochemical etiologies such as inflammation and oxidative stress. The diabetic state also contributes to increased acetylcholinesterase (AChE) activity, which is one of the factors leading to neurodegeneration in AD. The aim of this study was to assess in vitro the effects of metformin, phenformin, and metformin sulfenamide prodrugs on the activity of human AChE and butyrylcholinesterase (BuChE) and establish the type of inhibition. Metformin inhibited 50% of the AChE activity at micromolar concentrations (2.35  μ mol/mL, mixed type of inhibition) and seemed to be selective towards AChE since it presented low anti-BuChE activity. The tested metformin prodrugs inhibited cholinesterases (ChE) at nanomolar range and thus were more active than metformin or phenformin. The cyclohexyl sulfenamide prodrug demonstrated the highest activity towards both AChE (IC 50  = 890 nmol/mL, noncompetitive inhibition) and BuChE (IC 50  = 28 nmol/mL, mixed type inhibition), while the octyl sulfenamide prodrug did not present anti-AChE activity, but exhibited mixed inhibition towards BuChE (IC 50  = 184 nmol/mL). Therefore, these two bulkier prodrugs were concluded to be the most selective compounds for BuChE over AChE. In conclusion, it was demonstrated that biguanides present a novel class of inhibitors for AChE and BuChE and encourages further studies of these compounds for developing both selective and nonselective inhibitors of ChEs in the future.

  20. Efficacy of Enzyme and Substrate Reduction Therapy with a Novel Antagonist of Glucosylceramide Synthase for Fabry Disease

    PubMed Central

    Ashe, Karen M; Budman, Eva; Bangari, Dinesh S; Siegel, Craig S; Nietupski, Jennifer B; Wang, Bing; Desnick, Robert J; Scheule, Ronald K; Leonard, John P; Cheng, Seng H; Marshall, John

    2015-01-01

    Fabry disease, an X-linked glycosphingolipid storage disorder, is caused by the deficient activity of α-galactosidase A (α-Gal A). This results in the lysosomal accumulation in various cell types of its glycolipid substrates, including globotriaosylceramide (GL-3) and lysoglobotriaosylceramide (globotriaosyl lysosphingolipid, lyso-GL-3), leading to kidney, heart, and cerebrovascular disease. To complement and potentially augment the current standard of care, biweekly infusions of recombinant α-Gal A, the merits of substrate reduction therapy (SRT) by selectively inhibiting glucosylceramide synthase (GCS) were examined. Here, we report the development of a novel, orally available GCS inhibitor (Genz-682452) with pharmacological and safety profiles that have potential for treating Fabry disease. Treating Fabry mice with Genz-682452 resulted in reduced tissue levels of GL-3 and lyso-GL-3 and a delayed loss of the thermal nociceptive response. Greatest improvements were realized when the therapeutic intervention was administered to younger mice before they developed overt pathology. Importantly, as the pharmacologic profiles of α-Gal A and Genz-682452 are different, treating animals with both drugs conferred the greatest efficacy. For example, because Genz-682452, but not α-Gal A, can traverse the blood–brain barrier, levels of accumulated glycosphingolipids were reduced in the brain of Genz-682452–treated but not α-Gal A–treated mice. These results suggest that combining substrate reduction and enzyme replacement may confer both complementary and additive therapeutic benefits in Fabry disease. PMID:25938659

  1. Melanoma cell therapy: Endothelial progenitor cells as shuttle of the MMP12 uPAR-degrading enzyme

    PubMed Central

    Laurenzana, Anna; Biagioni, Alessio; D'Alessio, Silvia; Bianchini, Francesca; Chillà, Anastasia; Margheri, Francesca; Luciani, Cristina; Mazzanti, Benedetta; Pimpinelli, Nicola; Torre, Eugenio; Danese, Silvio; Calorini, Lido; Rosso, Mario Del; Fibbi, Gabriella

    2014-01-01

    The receptor for the urokinase-type plasminogen activator (uPAR) accounts for many features of cancer progression, and is therefore considered a target for anti-tumoral therapy. Only full length uPAR mediates tumor progression. Matrix-metallo-proteinase-12 (MMP12)-dependent uPAR cleavage results into the loss of invasion properties and angiogenesis. MMP12 can be employed in the field of “targeted therapies” as a biological drug to be delivered directly in patient's tumor mass. Endothelial Progenitor Cells (EPCs) are selectively recruited within the tumor and could be used as cellular vehicles for delivering anti-cancer molecules. The aim of our study is to inhibit cancer progression by engeneering ECFCs, a subset of EPC, with a lentivirus encoding the anti-tumor uPAR-degrading enzyme MMP12. Ex vivo manipulated ECFCs lost the capacity to perform capillary morphogenesis and acquired the anti-tumor and anti-angiogenetic activity. In vivo MMP12-engineered ECFCs cleaved uPAR within the tumor mass and strongly inhibited tumor growth, tumor angiogenesis and development of lung metastasis. The possibility to exploit tumor homing and activity of autologous MMP12-engineered ECFCs represents a novel way to combat melanoma by a “personalized therapy”, without rejection risk. The i.v. injection of radiolabelled MMP12-ECFCs can thus provide a new theranostic approach to control melanoma progression and metastasis. PMID:25003596

  2. Plant-based oral delivery of β-glucocerebrosidase as an enzyme replacement therapy for Gaucher's disease.

    PubMed

    Shaaltiel, Yoseph; Gingis-Velitski, Svetlana; Tzaban, Salit; Fiks, Nadia; Tekoah, Yoram; Aviezer, David

    2015-10-01

    Gaucher's disease (GD), a lysosomal storage disorder caused by mutations in the gene encoding glucocerebrosidase (GCD), is currently treated by enzyme replacement therapy (ERT) using recombinant GCD that is administered intravenously every 2 weeks. However, intravenous administration includes discomfort or pain and might cause local and systemic infections that may lead to low patient compliance. An orally administered drug has the potential to alleviate these problems. In this study, we describe the potential use of plant cells as a vehicle for the oral delivery of recombinant human GCD (prGCD) expressed in carrot cells. The in vitro results demonstrate that the plant cells protect the recombinant protein in the gastric fluids and may enable absorption into the blood. Feeding experiments, with rat and pig as model animals, using carrot cells containing prGCD, show that active recombinant prGCD was found in the digestive tract and blood system and reached both, liver and spleen, the target organs in GD. These results demonstrate that the oral administration of proteins encapsulated in plant cells is feasible. Specifically, carrot cells containing recombinant human prGCD can be used as an oral delivery system and are a feasible alternative to intravenous administration of ERT for GD. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  3. Expression of Eukaryotic Initiation Factor 5A and Hypusine Forming Enzymes in Glioblastoma Patient Samples: Implications for New Targeted Therapies

    PubMed Central

    Preukschas, Michael; Hagel, Christian; Schulte, Alexander; Weber, Kristoffer; Lamszus, Katrin; Sievert, Henning; Pällmann, Nora; Bokemeyer, Carsten; Hauber, Joachim; Braig, Melanie; Balabanov, Stefan

    2012-01-01

    Glioblastomas are highly aggressive brain tumors of adults with poor clinical outcome. Despite a broad range of new and more specific treatment strategies, therapy of glioblastomas remains challenging and tumors relapse in all cases. Recent work demonstrated that the posttranslational hypusine modification of the eukaryotic initiation factor 5A (eIF-5A) is a crucial regulator of cell proliferation, differentiation and an important factor in tumor formation, progression and maintenance. Here we report that eIF-5A as well as the hypusine-forming enzymes deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH) are highly overexpressed in glioblastoma patient samples. Importantly, targeting eIF-5A and its hypusine modification with GC7, a specific DHS-inhibitor, showed a strong antiproliferative effect in glioblastoma cell lines in vitro, while normal human astrocytes were not affected. Furthermore, we identified p53 dependent premature senescence, a permanent cell cycle arrest, as the primary outcome in U87-MG cells after treatment with GC7. Strikingly, combined treatment with clinically relevant alkylating agents and GC7 had an additive antiproliferative effect in glioblastoma cell lines. In addition, stable knockdown of eIF-5A and DHS by short hairpin RNA (shRNA) could mimic the antiproliferative effects of GC7. These findings suggest that pharmacological inhibition of eIF-5A may represent a novel concept to treat glioblastomas and may help to substantially improve the clinical course of this tumor entity. PMID:22927971

  4. Cerebellar Alterations and Gait Defects as Therapeutic Outcome Measures for Enzyme Replacement Therapy in α-Mannosidosis

    PubMed Central

    Damme, Markus; Stroobants, Stijn; Walkley, Steven U.; Lüllmann-Rauch, Renate; D`Hooge, Rudi; Fogh, Jens; Saftig, Paul; Lübke, Torben; Blanz, Judith

    2011-01-01

    α-Mannosidosis is a rare lysosomal storage disease with accumulation of undegraded mannosyl-linked oligosaccharides in cells throughout the body, most notably in the CNS. This leads to a broad spectrum of neurological manifestations, including progressive intellectual impairment, disturbed motor functions and cerebellar atrophy. To develop therapeutic outcome measures for enzyme replacement therapy (ERT) that could be used for human patients, a gene knockout model of α-mannosidosis in mice was analyzed for CNS pathology and motor deficits. In the cerebellar molecular layer, α-mannosidosis mice display clusters of activated Bergman glia, infiltration of phagocytic macrophages and accumulation of free cholesterol and gangliosides (GM1), notably in regions lacking Purkinje cells. α-mannosidosis brain lysates also displayed increased expression of Lamp1 and hyperglycosylation of the cholesterol binding protein NPC2. Detailed assessment of motor function revealed age-dependent gait defects in the mice that resemble the disturbed motor function in human patients. Short-term ERT partially reversed the observed cerebellar pathology with fewer activated macrophages and astrocytes but unchanged levels of hyperglycosylated NPC2, gangliosides and cholesterol. The present study demonstrates cerebellar alterations in α-mannosidosis mice that relate to the motor deficits and pathological changes seen in human patients and can be used as therapeutic outcome measures. PMID:21157375

  5. A glutathione-responsive sulfur dioxide polymer prodrug as a nanocarrier for combating drug-resistance in cancer chemotherapy.

    PubMed

    Shen, Wei; Liu, Wanguo; Yang, Huailin; Zhang, Peng; Xiao, Chunsheng; Chen, Xuesi

    2018-02-03

    Multidrug resistance (MDR) in cancer remains a significant challenge for curing cancer by chemotherapy. In this work, a kind of glutathione (GSH)-responsive polymer prodrug of SO 2 was designed and synthesized, which presented synergistic effect with doxorubicin (DOX) for combating MCF-7 ADR human breast cancer cell. Firstly, a small molecular prodrug of SO 2 , N-(3-azidopropyl)-2,4-dinitrobenzenesulfonamide (AP-DNs), was chemically conjugated onto the side chain of methoxy poly (ethylene glycol)-block-poly (γ-propargyl-l-glutamate) (mPEG-PPLG) block copolymer to generate an amphiphilic polymer prodrug of SO 2 , mPEG-PLG (DNs). The obtained mPEG-PLG (DNs) prodrug could self-assemble into micelles in aqueous media and release SO 2 rapidly in response to thiol compounds. Then, DOX was loaded into mPEG-PLG (DNs) nanoparticles with ultrahigh drug-loading efficiency (97.3%). In vitro drug release tests indicated that the DOX-loaded nanoparticles could simultaneously release SO 2 and DOX by GSH triggering. Moreover, the effective cellular uptake of the DOX-loaded nanoparticles and subsequent intracellular release of SO 2 and DOX were verified by confocal laser scanning microscopy (CLSM) and flow cytometry (FCM) analyses. The released SO 2 could promote the reactive oxygen species (ROS) level in tumor cells, which thereby resulted in oxidative damages of cancer cells, together with restoration of MCF-7 ADR cells sensitivity to DOX. As a result, the released DOX and SO 2 showed synergistic therapeutic effect against MCF-7 ADR cells. In vivo antitumor evaluation further indicated that, compared with free DOX, the DOX-loaded nanoparticles exhibited better antitumor effect in a MCF-7 ADR-xenografted nude mice model while had lower system toxicity. Overall, we demonstrated, for the first time, that a SO 2 polymer prodrug, acting as a stimuli-responsive nanocarrier to codeliver DOX, can efficiently inhibit the proliferation of MDR tumor cells, which may offer a new weapon

  6. A fully human anti-Ep-CAM scFv-beta-glucuronidase fusion protein for selective chemotherapy with a glucuronide prodrug.

    PubMed

    de Graaf, M; Boven, E; Oosterhoff, D; van der Meulen-Muileman, I H; Huls, G A; Gerritsen, W R; Haisma, H J; Pinedo, H M

    2002-03-04

    Monoclonal antibodies against tumour-associated antigens could be useful to deliver enzymes selectively to the site of a tumour for activation of a non-toxic prodrug. A completely human fusion protein may be advantageous for repeated administration, as host immune responses may be avoided. We have constructed a fusion protein consisting of a human single chain Fv antibody, C28, against the epithelial cell adhesion molecule and the human enzyme beta-glucuronidase. The sequences encoding C28 and human enzyme beta-glucuronidase were joined by a sequence encoding a flexible linker, and were preceded by the IgGkappa signal sequence for secretion of the fusion protein. A CHO cell line was engineered to secrete C28-beta-glucuronidase fusion protein. Antibody specificity and enzyme activity were retained in the secreted fusion protein that had an apparent molecular mass of 100 kDa under denaturing conditions. The fusion protein was able to convert a non-toxic prodrug of doxorubicin, N-[4-doxorubicin-N-carbonyl(oxymethyl)phenyl]-O-beta-glucuronyl carbamate to doxorubicin, resulting in cytotoxicity. A bystander effect was demonstrated, as doxorubicin was detected in all cells after N-[4-doxorubicin-N-carbonyl(oxymethyl)phenyl]-O-beta-glucuronyl carbamate administration when only 10% of the cells expressed the fusion protein. This is the first fully human and functional fusion protein consisting of an scFv against epithelial cell adhesion molecule and human enzyme beta-glucuronidase for future use in tumour-specific activation of a non-toxic glucuronide prodrug. Copyright 2002 Cancer Research UK

  7. A fully human anti-Ep-CAM scFv-beta-glucuronidase fusion protein for selective chemotherapy with a glucuronide prodrug

    PubMed Central

    de Graaf, M; Boven, E; Oosterhoff, D; van der Meulen-Muileman, I H; Huls, G A; Gerritsen, W R; Haisma, H J; Pinedo, H M

    2002-01-01

    Monoclonal antibodies against tumour-associated antigens could be useful to deliver enzymes selectively to the site of a tumour for activation of a non-toxic prodrug. A completely human fusion protein may be advantageous for repeated administration, as host immune responses may be avoided. We have constructed a fusion protein consisting of a human single chain Fv antibody, C28, against the epithelial cell adhesion molecule and the human enzyme β-glucuronidase. The sequences encoding C28 and human enzyme β-glucuronidase were joined by a sequence encoding a flexible linker, and were preceded by the IgGκ signal sequence for secretion of the fusion protein. A CHO cell line was engineered to secrete C28-β-glucuronidase fusion protein. Antibody specificity and enzyme activity were retained in the secreted fusion protein that had an apparent molecular mass of 100 kDa under denaturing conditions. The fusion protein was able to convert a non-toxic prodrug of doxorubicin, N-[4-doxorubicin-N-carbonyl(oxymethyl)phenyl]-O-β-glucuronyl carbamate to doxorubicin, resulting in cytotoxicity. A bystander effect was demonstrated, as doxorubicin was detected in all cells after N-[4-doxorubicin-N-carbonyl(oxymethyl)phenyl]-O-β-glucuronyl carbamate administration when only 10% of the cells expressed the fusion protein. This is the first fully human and functional fusion protein consisting of an scFv against epithelial cell adhesion molecule and human enzyme β-glucuronidase for future use in tumour-specific activation of a non-toxic glucuronide prodrug. British Journal of Cancer (2002) 86, 811–818. DOI: 10.1038/sj/bjc/6600143 www.bjcancer.com © 2002 Cancer Research UK PMID:11875747

  8. The beneficial effects of long-term enzyme replacement therapy on cardiac involvement in Japanese Fabry patients.

    PubMed

    Hongo, Kenichi; Ito, Keiichi; Date, Taro; Anan, Ikuko; Inoue, Yasunori; Morimoto, Satoshi; Ogawa, Kazuo; Kawai, Makoto; Kobayashi, Hiroshi; Kobayashi, Masahisa; Ida, Hiroyuki; Ohashi, Toya; Taniguchi, Ikuo; Yoshimura, Michihiro; Eto, Yoshikatsu

    2018-06-01

    Fabry disease is a hereditary disorder that occurs due to the reduction or absence of alpha-galactosidase A activity, which leads to cardiac involvement including left ventricular hypertrophy (LVH). Enzyme replacement therapy (ERT) provides better patient outcomes by preventing serious complications. However, there have been very few studies on the long-term effects of ERT on the cardiac manifestations in Japanese Fabry patients. We retrospectively analyzed the data from the medical records of 42 Fabry patients (male, n = 17; female, n = 25) who were followed at Jikei University Hospital, and in whom the long-term effects of ERT could be evaluated (median follow-up period: male, 11 years; female, 8 years). The slope of the left ventricular mass (LVM) increase was 3.02 ± 3.41 g/m 2 /year in males and 1.69 ± 2.73 g/m 2 /year in females. In a subgroup analysis, the slopes of males with and without LVH did not differ to a statistically significant extent; however, the slope in female patients without LVH was significantly smaller than that of female patients with LVH. We then compared our data to the natural historical data that have previously been reported. In comparison to the previously reported data, we found a significant reduction in the LVM changes (g/height 2.7 /year) of patients who received long-term ERT (male, 4.07 ± 1.03 to 1.25 ± 1.39; female, 2.31 ± 0.81 to 0.78 ± 1.23). Long-term ERT effectively prevents LVH in Fabry patients. This effect was also observed in the patients with LVH prior to the initiation of ERT. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Enzyme replacement therapy with galsulfase in 34 children younger than five years of age with MPS VI.

    PubMed

    Horovitz, Dafne D G; Magalhães, Tatiana S P C; Acosta, Angelina; Ribeiro, Erlane M; Giuliani, Liane R; Palhares, Durval B; Kim, Chong A; de Paula, Ana Carolina; Kerstenestzy, Marcelo; Pianovski, Mara A D; Costa, Maria Ione F; Santos, Francisca C; Martins, Ana Maria; Aranda, Carolina S; Correa Neto, Jordão; Holanda, Gervina Brady Moreira; Cardoso, Laércio; da Silva, Carlos A B; Bonatti, Renata C F; Ribeiro, Bethania F R; Rodrigues, Maria do Carmo S; Llerena, Juan C

    2013-05-01

    Mucopolysaccharidosis type VI (MPS VI) is a progressive, chronic and multisystem lysosomal storage disease with a wide disease spectrum. Clinical and biochemical improvements have been reported for MPS VI patients on enzyme replacement therapy (ERT) with rhASB (recombinant human arylsulfatase B; galsulfase, Naglazyme®, BioMarin Pharmaceutical Inc.), making early diagnosis and intervention imperative for optimal patient outcomes. Few studies have included children younger than five years of age. This report describes 34 MPS VI patients that started treatment with galsulfase before five years of age. Data from patients who initiated treatment at <5 years of age were collected from patients' medical records. Baseline and follow-up assessments of common symptoms that led to diagnosis and that were used to evaluate disease progression and treatment efficacy were evaluated. A significant negative correlation was seen with treatment with ERT and urinary GAG levels. Of those with baseline and follow-up growth data, 47% remained on their pre-treatment growth curve or moved to a higher percentile after treatment. Of the 9 patients with baseline and follow-up sleep studies, 5 remained unaffected and 1 patient initially with mild sleep apnea showed improvement. Data regarding cardiac, ophthalmic, central nervous system, hearing, surgical interventions and development are also reported. No patient discontinued treatment due to an adverse event and all that were treatment-emergent resolved. The prescribed dosage of 1mg/kg IV weekly with galsulfase ERT is shown to be safe and effective in slowing and/or improving certain aspects of the disease, although patients should be closely monitored for complications associated with the natural history of the disease, especially cardiac valve involvement and spinal cord compression. A long-term follow-up investigation of this group of children will provide further information on the benefits of early treatment as well as disease

  10. Activities of Daily Living in patients with Hunter syndrome: Impact of enzyme replacement therapy and hematopoietic stem cell transplantation

    PubMed Central

    Tanjuakio, Julian; Suzuki, Yasuyuki; Patel, Pravin; Yasuda, Eriko; Kubaski, Francyne; Tanaka, Akemi; Yabe, Hiromasa; Mason, Robert W.; Montaño, Adriana M.; Orii, Kenji E.; Orii, Koji O.; Fukao, Toshiyuki; Orii, Tadao; Tomatsu, Shunji

    2014-01-01

    The aim of this study was to assess the Activities of Daily Living (ADL) in patients with Hunter syndrome (mucopolysaccharidosis II; MPS II) using a newly designed ADL questionnaire. We applied the questionnaire to evaluate clinical phenotypes and therapeutic efficacies of enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT). We also explored early signs and symptoms to make early diagnosis feasible. We devised a new ADL questionnaire with three domains: “Movement,” “Movement with Cognition,” and “Cognition.” Each domain has four subcategories rated on a 5-point scale based on level of assistance. We also scored signs and symptoms unique to MPS by 12 subcategories (five points per category), providing 60 points in total. The questionnaire was first administered to 138 healthy Japanese controls (0.33 – 50 years), and successively, to 74 Japanese patients with Hunter syndrome (4 – 49 years). The patient cohort consisted of 51 severe and 23 attenuated phenotypes; 20 patients treated with HSCT, 23 patients treated early with ERT (≤ 8 years), and 25 patients treated late with ERT (> 8 years), and 4 untreated patients. Among 18 severe phenotypic patients treated by HSCT, 10 were designated as early HSCT (≤ 5 years), while 8 were designated as late HSCT (> 5 years). Scores from patients with severe phenotypes were lower than controls and attenuated phenotypes in all categories. Among patients with severe phenotypes, there was a trend that HSCT provides a higher ADL score than early ERT, and there was a significant difference in ADL scores between late ERT and HSCT groups. Early ERT and early HSCT provided a higher score than late ERT and late HSCT, respectively. In conclusion, we have evaluated the feasibility of a new questionnaire in control population and patients with Hunter syndrome, leading to a novel evaluation method for clinical phenotypes and therapeutic efficacy. Early treatment with HSCT provides a better

  11. Effects of Neonatal Enzyme Replacement Therapy and Simvastatin Treatment on Cervical Spine Disease in Mucopolysaccharidosis I Dogs

    PubMed Central

    Chiaro, Joseph A; O’Donnell, Patricia; Shore, Eileen M; Malhotra, Neil R; Ponder, Katherine P; Haskins, Mark E; Smith, Lachlan J

    2014-01-01

    Mucopolysaccharidosis I (MPS I) is a lysosomal storage disease characterized by deficient α-L-iduronidase activity, leading to the accumulation of poorly degraded glycosaminoglycans (GAGs). Children with MPS I exhibit high incidence of spine disease, including accelerated disc degeneration and vertebral dysplasia, which in turn lead to spinal cord compression and kypho-scoliosis. In this study we investigated the efficacy of neonatal enzyme replacement therapy (ERT), alone or in combination with oral simvastatin (ERT+SIM) for attenuating cervical spine disease progression in MPS I, using a canine model. Four groups were studied: normal controls; MPS I untreated; MPS I ERT treated; and MPS I ERT+SIM treated. Animals were euthanized at one year-of-age. Intervertebral disc condition and spinal cord compression were evaluated from MRIs and plain radiographs, vertebral bone condition and odontoid hypoplasia were evaluated using microcomputed tomography, and epiphyseal cartilage to bone conversion was evaluated histologically. Untreated MPS I animals exhibited more advanced disc degeneration and more severe spinal cord compression than normal animals. Both treatment groups resulted in partial preservation of disc condition and cord compression, with ERT+SIM not significantly better than ERT alone. Untreated MPS I animals had significantly lower vertebral trabecular bone volume and mineral density, while ERT treatment resulted in partial preservation of these properties. ERT+SIM treatment demonstrated similar, but not greater, efficacy. Both treatment groups partially normalized endochondral ossification in the vertebral epiphyses (as indicated by absence of persistent growth plate cartilage), and odontoid process size and morphology. These results indicate that ERT begun from a very early age attenuates the severity of cervical spine disease in MPS I, particularly for the vertebral bone and odontoid process, and that additional treatment with simvastatin does not

  12. Indoleamine-2,3-dioxygenase, an immunosuppressive enzyme that inhibits natural killer cell function, as a useful target for ovarian cancer therapy

    PubMed Central

    WANG, DONGDONG; SAGA, YASUSHI; MIZUKAMI, HIROAKI; SATO, NAOTO; NONAKA, HIROAKI; FUJIWARA, HIROYUKI; TAKEI, YUJI; MACHIDA, SHIZUO; TAKIKAWA, OSAMU; OZAWA, KEIYA; SUZUKI, MITSUAKI

    2012-01-01

    This study examined the role of the immunosuppressive enzyme indoleamine-2,3-dioxygenase (IDO) in ovarian cancer progression, and the possible application of this enzyme as a target for ovarian cancer therapy. We transfected a short hairpin RNA vector targeting IDO into the human ovarian cancer cell line SKOV-3, that constitutively expresses IDO and established an IDO downregulated cell line (SKOV-3/shIDO) to determine whether inhibition of IDO mediates the progression of ovarian cancer. IDO downregulation suppressed tumor growth and peritoneal dissemination in vivo, without influencing cancer cell growth. Moreover, IDO downregulation enhanced the sensitivity of cancer cells to natural killer (NK) cells in vitro, and promoted NK cell accumulation in the tumor stroma in vivo. These findings indicate that downregulation of IDO controls ovarian cancer progression by activating NK cells, suggesting IDO targeting as a potential therapy for ovarian cancer. PMID:22179492

  13. Validation of an enzyme-linked immunosorbent assay that detects Histoplasma capsulatum antigenuria in Colombian patients with AIDS for diagnosis and follow-up during therapy.

    PubMed

    Caceres, Diego H; Scheel, Christina M; Tobón, Angela M; Ahlquist Cleveland, Angela; Restrepo, Angela; Brandt, Mary E; Chiller, Tom; Gómez, Beatriz L

    2014-09-01

    We validated an antigen capture enzyme-linked immunosorbent assay (ELISA) in Colombian persons with AIDS and proven histoplasmosis and evaluated the correlation between antigenuria and clinical improvement during follow-up. The sensitivity of the Histoplasma capsulatum ELISA was 86%, and the overall specificity was 94%. The antigen test successfully monitored the response to therapy. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  14. The role of arginine and the modified arginine deiminase enzyme ADI-PEG 20 in cancer therapy with special emphasis on Phase I/II clinical trials.

    PubMed

    Synakiewicz, Anna; Stachowicz-Stencel, Teresa; Adamkiewicz-Drozynska, Elzbieta

    2014-11-01

    The metabolic differences between normal, healthy cells and neoplastic cells have been exploited by anticancer therapies targeting metabolic pathways. Various studies of malignant processes have demonstrated disturbances in both arginine synthesis and metabolism that enhance or inhibit tumor cell growth. Consequently, there has been an increased interest in the arginine-depleting enzyme arginine deiminase (ADI) as a potential antineoplastic therapy. This review summarizes the literature on the potential anti-cancer therapeutics arginine and ADI, an arginine-catabolizing enzyme. The authors searched the MEDLINE database PubMed using the key words: 'arginine, 'ADI', 'arginine in cancer' and 'ADI and cancer'. The authors evaluate prospective randomized studies on cancer patients between 2004 and 2013 as well as ongoing research found through the US National Institutes of Health trial database. The results of current studies are promising but do not give unequivocal answers and so it is impossible to recommend arginine or its enzyme ADI as a therapeutic. In the opinion of the authors, further identification of arginine-dependent malignant tumors and their metabolism should be investigated. Furthermore, the use of these chemicals, in combination with other chemotherapeutics drugs, should be investigated and indeed may improve the success of arginine-depleting enzymes such as pegylated ADI (ADI-PEG20).

  15. Differential In Vitro and In Vivo Toxicities of Antimicrobial Peptide Prodrugs for Potential Use in Cystic Fibrosis

    PubMed Central

    Schütte, André; Reeves, Emer; Greene, Catherine; Humphreys, Hilary; Mall, Marcus; Fitzgerald-Hughes, Deirdre; Devocelle, Marc

    2016-01-01

    There has been considerable interest in the use of antimicrobial peptides (AMPs) as antimicrobial agents for the treatment of many conditions, including cystic fibrosis (CF). The challenging conditions of the CF patient lung require robust AMPs that are active in an environment of high proteolytic activity but that also have low cytotoxicity and immunogenicity. Previously, we developed prodrugs of AMPs that limited the cytotoxic effects of AMP treatment by rendering the antimicrobial activity dependent on the host enzyme neutrophil elastase (NE). However, cytotoxicity remained an issue. Here, we describe the further optimization of the AMP prodrug (pro-AMP) model for CF to produce pro-WMR, a peptide with greatly reduced cytotoxicity (50% inhibitory concentration against CFBE41o- cells, >300 μM) compared to that of the previous group of pro-AMPs. The bactericidal activity of pro-WMR was increased in NE-rich bronchoalveolar lavage (BAL) fluid from CF patients (range, 8.4% ± 6.9% alone to 91.5% ± 5.8% with BAL fluid; P = 0.0004), an activity differential greater than that of previous pro-AMPs. In a murine model of lung delivery, the pro-AMP modification reduced host toxicity, with pro-WMR being less toxic than the active peptide. Previously, host toxicity issues have hampered the clinical application of AMPs. However, the development of application-specific AMPs with modifications that minimize toxicity similar to those described here can significantly advance their potential use in patients. The combination of this prodrug strategy with a highly active AMP has the potential to produce new therapeutics for the challenging conditions of the CF patient lung. PMID:26902766

  16. In vitro evaluation of dendrimer prodrugs for oral drug delivery.

    PubMed

    Najlah, Mohammad; Freeman, Sally; Attwood, David; D'Emanuele, Antony

    2007-05-04

    Dendrimer-based prodrugs were used to enhance the transepithelial permeability of naproxen, a low solubility model drug. The stability of the dendrimer-naproxen link was assessed. Naproxen was conjugated to G0 polyamidoamine (PAMAM) dendrimers either by an amide bond or an ester bond. The stability of G0 prodrugs was evaluated in 80% human plasma and 50% rat liver homogenate. The cytotoxicity of conjugates towards Caco-2 cells was determined and the transport of the conjugates across Caco-2 monolayers (37 degrees C) was reported. In addition, one lauroyl chain (L) was attached to the surface group of G0 PAMAM dendrimer of the diethylene glycol ester conjugate (G0-deg-NAP) to enhance permeability. The lactic ester conjugate, G0-lact-NAP, hydrolyzed slowly in 80% human plasma and in 50% rat liver homogenate (t(1/2)=180 min). G0-deg-NAP was hydrolyzed more rapidly in 80% human plasma (t(1/2)=51 min) and was rapidly cleaved in 50% liver homogenate (t(1/2)=4.7 min). The conjugates were non-toxic when exposed to Caco-2 cells for 3h. Permeability studies showed a significant enhancement in the transport of naproxen when conjugated to dendrimers; L-G0-deg-NAP yielding the highest permeability. Dendrimer-based prodrugs with appropriate linkers have potential as carriers for the oral delivery of low solubility drugs such as naproxen.

  17. Hypoxia-activated prodrug enhances therapeutic effect of sunitinib in melanoma

    PubMed Central

    Liu, Shujing; Tetzlaff, Michael T.; Wang, Tao; Chen, Xiang; Yang, Ruifeng; Kumar, Suresh M.; Vultur, Adina; Li, Pengxiang; Martin, James S.; Herlyn, Meenhard; Amaravadi, Ravi

    2017-01-01

    Angiogenesis is a critical step during tumor progression. Anti-angiogenic therapy has only provided modest benefits in delaying tumor progression despite its early promise in cancer treatment. It has been postulated that anti-angiogenic therapy may promote the emergence of a more aggressive cancer cell phenotype by generating increased tumor hypoxia—a well-recognized promoter of tumor progression. TH-302 is a 2-nitroimidazole triggered hypoxia-activated prodrug (HAP) which has been shown to selectively target the hypoxic tumor compartment and reduce tumor volume. Here, we show that melanoma cells grown under hypoxic conditions exhibit increased resistance to a wide variety of therapeutic agents in vitro and generate larger and more aggressive tumors in vivo than melanoma cells grown under normoxic conditions. However, hypoxic melanoma cells exhibit a pronounced sensitivity to TH-302 which is further enhanced by the addition of sunitinib. Short term sunitinib treatment fails to prolong the survival of melanoma bearing genetically engineered mice (Tyr::CreER; BRafCA;Ptenlox/lox) but increases tumor hypoxia. Long term TH-302 alone modestly prolongs the overall survival of melanoma bearing mice. Combination therapy of TH-302 with sunitinib further increases the survival of treated mice. These studies provide a translational rationale for combining hypoxic tumor cell targeted therapies with anti-angiogenics for treatment of melanoma. PMID:29383148

  18. Long term clinical history of an Italian cohort of infantile onset Pompe disease treated with enzyme replacement therapy.

    PubMed

    Parini, Rossella; De Lorenzo, Paola; Dardis, Andrea; Burlina, Alberto; Cassio, Alessandra; Cavarzere, Paolo; Concolino, Daniela; Della Casa, Roberto; Deodato, Federica; Donati, Maria Alice; Fiumara, Agata; Gasperini, Serena; Menni, Francesca; Pagliardini, Veronica; Sacchini, Michele; Spada, Marco; Taurisano, Roberta; Valsecchi, Maria Grazia; Di Rocco, Maja; Bembi, Bruno

    2018-02-08

    Enzyme replacement therapy (ERT) has deeply modified the clinical history of Infantile Onset Pompe Disease (IOPD). However, its long-term effectiveness is still not completely defined. Available data shows a close relationship between clinical outcome and patients' cross-reactive immunological status (CRIM), being CRIM-negative status a negative prognostic factor. At the same time limited data are available on the long-term treatment in CRIM-positive infants. A retrospective multicentre observational study was designed to analyse the long-term effectiveness of ERT in IOPD. Thirteen Italian centres spread throughout the country were involved and a cohort of 28 patients (15 females, 13 males, born in the period: February 2002-January 2013) was enrolled. IOPD diagnosis was based on clinical symptoms, enzymatic and molecular analysis. All patients received ERT within the first year of life. Clinical, laboratory, and functional data (motor, cardiac and respiratory) were collected and followed for a median period of 71 months (5 years 11 months). Median age at onset, diagnosis and start of ERT were 2, 3 and 4 months, respectively. CRIM status was available for 24/28 patients: 17/24 (71%) were CRIM-positive. Nineteen patients (67%) survived > 2 years: 4 were CRIM-negative, 14 CRIM-positive and one unknown. Six patients (5 CRIM-positive and one unknown) never needed ventilation support (21,4%) and seven (6 CRIM-positive and one unknown: 25%) developed independent ambulation although one subsequently lost this function. Brain imaging study was performed in 6 patients and showed peri-ventricular white matter abnormalities in all of them. Clinical follow-up confirmed the better prognosis for CRIM-positive patients, though a slow, progressive worsening of motor and/or respiratory functions was detected in 8 patients. These data are the result of the longest independent retrospective study on ERT in IOPD reported so far outside clinical trials. The data obtained

  19. Long-term outcome of enzyme-replacement therapy in advanced Fabry disease: evidence for disease progression towards serious complications

    PubMed Central

    Weidemann, F; Niemann, M; Störk, S; Breunig, F; Beer, M; Sommer, C; Herrmann, S; Ertl, G; Wanner, C

    2013-01-01

    Objective The long-term effects of enzyme-replacement therapy (ERT) in Fabry disease are unknown. Thus, the aim of this study was to determine whether ERT in patients with advanced Fabry disease affects progression towards ‘hard’ clinical end-points in comparison with the natural course of the disease. Methods A total of 40 patients with genetically proven Fabry disease (mean age 40 ± 9 years; n = 9 women) were treated prospectively with ERT for 6 years. In addition, 40 subjects from the Fabry Registry, matched for age, sex, chronic kidney disease stage and previous transient ischaemic attack (TIA), served as a comparison group. The main outcome was a composite of stroke, end-stage renal disease (ESRD) and death. Secondary outcomes included changes in myocardial left ventricular (LV) wall thickness and replacement fibrosis, change in glomerular filtration rate (GFR), new TIA and change in neuropathic pain. Results During a median follow-up of 6.0 years (bottom and top quartiles: 5.1, 7.2), 15 events occurred in 13 patients (n = 7 deaths, n = 4 cases of ESRD and n = 4 strokes). Sudden death occurred (n = 6) only in patients with documented ventricular tachycardia and myocardial replacement fibrosis. The annual progression of myocardial LV fibrosis in the entire cohort was 0.6 ± 0.7%. As a result, posterior end-diastolic wall thinning was observed (baseline, 13.2 ± 2.0 mm; follow-up, 11.4 ± 2.1 mm; P < 0.01). GFR decreased by 2.3 ± 4.6 mL min−1 per year. Three patients experienced a TIA. The major clinical symptom was neuropathic pain (n = 37), and this symptom improved in 25 patients. The event rate was not different between the ERT group and the untreated (natural history) group of the Fabry Registry. Conclusion Despite ERT, clinically meaningful events including sudden cardiac death continue to develop in patients with advanced Fabry disease. PMID:23586858

  20. Pulmonary involvement in Fabry disease: effect of plasma globotriaosylsphingosine and time to initiation of enzyme replacement therapy.

    PubMed

    Franzen, Daniel; Haile, Sarah R; Kasper, David C; Mechtler, Thomas P; Flammer, Andreas J; Krayenbühl, Pierre A; Nowak, Albina

    2018-01-01

    Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by mutations of GLA gene leading to reduced α-galactosidase activity and resulting in a progressive accumulation of globotriaosylceramide (Gb3) and its deacylated derivative, globotriaosyl-sphingosine (Lyso-Gb3). Plasma Lyso-Gb3 levels serve as a disease severity and treatment monitoring marker during enzyme replacement therapy (ERT). Adult patients with AFD who had yearly pulmonary function tests between 1999 and 2015 were eligible for this observational study. Primary outcome measures were the change in z-score of forced expiratory volume in the first second (FEV 1 ) and FEV 1 /FVC over time. Plasma Lyso-Gb3 levels and the age of ERT initiation were investigated for their association with lung function decline. Fifty-three patients (42% male, median (range) age at diagnosis of AFD 34 (6-61) years in men, 34 (13-67) in women) were included. The greatest decrease of FEV 1 /FVC z-scores was observed in Classic men (-0.048 per year, 95% CI -0.081 to -0.014), compared with the Later-Onset men (+0.013,95% CI -0.055 to 0.082), Classic women (-0.008, 95% CI -0.035 to +0.020) and Later-Onset women (-0.013, 95% CI -0.084 to +0.058). Cigarette smoking (P=0.022) and late ERT initiation (P=0.041) were independently associated with faster FEV 1 decline. FEV 1 /FVC z-score decrease was significantly reduced after initiation of ERT initiation (-0.045 compared with -0.015, P=0.014). Furthermore, there was a trend towards a relevant influence of Lyso-Gb3 (P=0.098) on airflow limitation with age. Early ERT initiation seems to preserve pulmonary function. Plasma Lyso-Gb3 is maybe a useful predictor for airflow limitation. Classic men need a closer monitoring of the lung function.

  1. Effect of insulin analog initiation therapy on LDL/HDL subfraction profile and HDL associated enzymes in type 2 diabetic patients.

    PubMed

    Aslan, Ibrahim; Kucuksayan, Ertan; Aslan, Mutay

    2013-04-24

    Insulin treatment can lead to good glycemic control and result in improvement of lipid parameters in type 2 diabetic patients. This study was designed to evaluate the effect of insulin analog initiation therapy on low-density lipoprotein (LDL)/ high-density lipoprotein (HDL) sub-fractions and HDL associated enzymes in type 2 diabetic patients during early phase. Twenty four type 2 diabetic patients with glycosylated hemoglobin (HbA1c) levels above 10% despite ongoing combination therapy with sulphonylurea and metformin were selected. Former treatment regimen was continued for the first day followed by substitution of sulphonylurea therapy with different insulin analogs (0.4 U/kg/day) plus metformin. Glycemic profiles were determined over 72 hours by continuous glucose monitoring system (CGMS) and blood samples were obtained from all patients at 24 and 72 hours. Plasma levels of cholesteryl ester transfer protein (CETP), lecithin-cholesterol acyltransferase (LCAT), apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-I) were determined by enzyme-linked immunosorbent assay (ELISA). Measurement of CETP and LCAT activity was performed via fluorometric analysis. Paraoxonase (PON1) enzyme activity was assessed from the rate of enzymatic hydrolysis of phenyl acetate to phenol formation. LDL and HDL subfraction analysis was done by continuous disc polyacrylamide gel electrophoresis. Mean blood glucose, total cholesterol (TC), triglyceride (TG) and very low-density lipoprotein cholesterol (VLDL-C) levels were significantly decreased while HDL-C levels were significantly increased after insulin treatment. Although LDL-C levels were not significantly different before and after insulin initiation therapy a significant increase in LDL-1 subgroup and a significant reduction in atherogenic LDL-3 and LDL-4 subgroups were observed. Insulin analog initiation therapy caused a significant increase in HDL-large, HDL- intermediate and a significant reduction in HDL-small subfractions

  2. JS-K, a Nitric Oxide Prodrug, Has Enhanced Cytotoxicity in Colon Cancer Cells with Knockdown of Thioredoxin Reductase 1

    PubMed Central

    Edes, Kornelia; Cassidy, Pamela; Shami, Paul J.; Moos, Philip J.

    2010-01-01

    Background The selenoenzyme thioredoxin reductase 1 has a complex role relating to cell growth. It is induced as a component of the cellular response to potentially mutagenic oxidants, but also appears to provide growth advantages to transformed cells by inhibiting apoptosis. In addition, selenocysteine-deficient or alkylated forms of thioredoxin reductase 1 have also demonstrated oxidative, pro-apoptotic activity. Therefore, a greater understanding of the role of thioredoxin reductase in redox initiated apoptotic processes is warranted. Methodology The role of thioredoxin reductase 1 in RKO cells was evaluated by attenuating endogenous thioredoxin reductase 1 expression with siRNA and then either inducing a selenium-deficient thioredoxin reductase or treatment with distinct redox challenges including, hydrogen peroxide, an oxidized lipid, 4-hydroxy-2-nonenol, and a nitric oxide donating prodrug. Thioredoxin redox status, cellular viability, and effector caspase activity were measured. Conclusions/Significance In cells with attenuated endogenous thioredoxin reductase 1, a stably integrated selenocysteine-deficient form of the enzyme was induced but did not alter either the thioredoxin redox status or the cellular growth kinetics. The oxidized lipid and the nitric oxide donor demonstrated enhanced cytotoxicity when thioredoxin reductase 1 was knocked-down; however, the effect was more pronounced with the nitric oxide prodrug. These results are consistent with the hypothesis that attenuation of the thioredoxin-system can promote apoptosis in a nitric oxide-dependent manner. PMID:20098717

  3. [Purine and pyrimidine nucleoside phosphorylases - remarkable enzymes still not fully understood].

    PubMed

    Bzowska, Agnieszka

    2015-01-01

    Purine and pyrimidine nucleoside phosphorylases catalyze the reversible phosphorolytic cleavage of the glycosidic bond of purine and pyrimidine nucleosides, and are key enzymes of the nucleoside salvage pathway. This metabolic route is the less costly alternative to the de novo synthesis of nucleosides and nucleotides, supplying cells with these important building blocks. Interest in nucleoside phosphorylases is not only due to their important role in metabolism of nucleosides and nucleotides, but also due to the potential medical use of the enzymes (all phosphorylases in activating prodrugs - nucleoside and nucleic base analogs, high-molecular mass purine nucleoside phosphorylases in gene therapy of some solid tumors) and their inhibitors (as selective immunosuppressive, anticancer and antiparasitic agents, and preventing inactivation of other nucleoside drugs). Phosphorylases are also convenient tools for efficient enzymatic synthesis of otherwise inaccessible nucleoside analogues. In this paper the contribution of Professor David Shugar and some of his colleagues and coworkers in studies of these remarkable enzymes carried out over nearly 40 years is discussed on the background of global research in this field.

  4. Antibody Epitope of Human α-Galactosidase A Revealed by Affinity Mass Spectrometry: A Basis for Reversing Immunoreactivity in Enzyme Replacement Therapy of Fabry Disease.

    PubMed

    Kukacka, Zdenek; Iurascu, Marius; Lupu, Loredana; Rusche, Hendrik; Murphy, Mary; Altamore, Lorenzo; Borri, Fabio; Maeser, Stefan; Papini, Anna Maria; Hennermann, Julia; Przybylski, Michael

    2018-05-08

    α-Galactosidase (αGal) is a lysosomal enzyme that hydrolyses the terminal α-galactosyl moiety from glycosphingolipids. Mutations in the encoding genes for αGal lead to defective or misfolded enzyme, which results in substrate accumulation and subsequent organ dysfunction. The metabolic disease caused by a deficiency of human α-galactosidase A is known as Fabry disease or Fabry-Anderson disease, and it belongs to a larger group known as lysosomal storage diseases. An effective treatment for Fabry disease has been developed by enzyme replacement therapy (ERT), which involves infusions of purified recombinant enzyme in order to increase enzyme levels and decrease the amounts of accumulated substrate. However, immunoreactivity and IgG antibody formation are major, therapy-limiting, and eventually life-threatening complications of ERT. The present study focused on the epitope determination of human α-galactosidase A against its antibody formed. Here we report the identification of the epitope of human αGal(309-332) recognized by a human monoclonal anti-αGal antibody, using a combination of proteolytic excision of the immobilized immune complex and surface plasmon resonance biosensing mass spectrometry. The epitope peptide, αGal(309-332), was synthesized by solid-phase peptide synthesis. Determination of its affinity by surface plasmon resonance analysis revealed a high binding affinity for the antibody (K D =39×10 -9  m), which is nearly identical to that of the full-length enzyme (K D =16×10 -9  m). The proteolytic excision affinity mass spectrometry method is shown here to be an efficient tool for epitope identification of an immunogenic lysosomal enzyme. Because the full-length αGal and the antibody epitope showed similar binding affinities, this provides a basis for reversing immunogenicity upon ERT by: 1) treatment of patients with the epitope peptide to neutralize antibodies, or 2) removal of antibodies by apheresis, and thus significantly

  5. Prodrugs as self-assembled hydrogels: a new paradigm for biomaterials.

    PubMed

    Vemula, Praveen Kumar; Wiradharma, Nikken; Ankrum, James A; Miranda, Oscar R; John, George; Karp, Jeffrey M

    2013-12-01

    Prodrug-based self-assembled hydrogels represent a new class of active biomaterials that can be harnessed for medical applications, in particular the design of stimuli responsive drug delivery devices. In this approach, a promoiety is chemically conjugated to a known-drug to generate an amphiphilic prodrug that is capable of forming self-assembled hydrogels. Prodrug-based self-assembled hydrogels are advantageous as they alter the solubility of the drug, enhance drug loading, and eliminate the use of harmful excipients. In addition, self-assembled prodrug hydrogels can be designed to undergo controlled drug release or tailored degradation in response to biological cues. Herein we review the development of prodrug-based self-assembled hydrogels as an emerging class of biomaterials that overcome several common limitations encountered in conventional drug delivery. Published by Elsevier Ltd.

  6. The In-Situ One-Step Synthesis of a PDC Macromolecular Pro-Drug and the Fabrication of a Novel Core-Shell Micell.

    PubMed

    Yu, Cui-Yun; Yang, Sa; Li, Zhi-Ping; Huang, Can; Ning, Qian; Huang, Wen; Yang, Wen-Tong; He, Dongxiu; Sun, Lichun

    2016-01-01

    The development of slow release nano-sized carriers for efficient antineoplastic drug delivery with a biocompatible and biodegradable pectin-based macromolecular pro-drug for tumor therapy has been reported in this study. Pectin-doxorubicin conjugates (PDC), a macromolecular pro-drug, were prepared via an amide condensation reaction, and a novel amphiphilic core-shell micell based on a PDC macromolecular pro-drug (PDC-M) was self-assembled in situ, with pectin as the hydrophilic shell and doxorubicin (DOX) as the hydrophobic core. Then the chemical structure of the PDC macromolecular pro-drug was identified by both Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy ((1)H-NMR), and proved that doxorubicin combined well with the pectin and formed macromolecular pro-drug. The PDC-M were observed to have an unregularly spherical shape and were uniform in size by scanning electron microscopy (SEM). The average particle size of PDC-M, further measured by a Zetasizer nanoparticle analyzer (Nano ZS, Malvern Instruments), was about 140 nm. The encapsulation efficiency and drug loading were 57.82% ± 3.7% (n = 3) and 23.852% ±2.3% (n = 3), respectively. The in vitro drug release behaviors of the resulting PDC-M were studied in a simulated tumor environment (pH 5.0), blood (pH 7.4) and a lysosome media (pH 6.8), and showed a prolonged slow release profile. Assays for antiproliferative effects and flow cytometry of the resulting PDC-M in HepG2 cell lines demonstrated greater properties of delayed and slow release as compared to free DOX. A cell viability study against endothelial cells further revealed that the resulting PDC-M possesses excellent cell compatibilities and low cytotoxicities in comparison with that of the free DOX. Hemolysis activity was investigated in rabbits, and the results also demonstrated that the PDC-M has greater compatibility in comparison with free DOX. This shows that the resulting PDC-M can ameliorate the

  7. Evaluation of salicylic acid fatty ester prodrugs for UV protection.

    PubMed

    Im, Jong Seob; Balakrishnan, Prabagar; Oh, Dong Hoon; Kim, Jung Sun; Jeon, Eun-Mi; Kim, Dae-Duk; Yong, Chul Soon; Choi, Han-Gon

    2011-07-01

    The purpose of this study was to investigate the physicochemical properties and in vitro evaluation of fatty ester prodrugs of salicylic acid for ultraviolet (UV) protection. The physicochemical properties such as lipophilicity, chemical stability and enzymatic hydrolysis were investigated with the following fatty ester prodrugs of salicylic acid: octanoyl (C8SA), nonanoyl (C9SA), decanoyl (C10SA), lauroyl (C12SA), myristoyl (C14SA) and palmitoyl oxysalicylate (C16SA). Furthermore, their skin permeation and accumulation were evaluated using a combination of common permeation enhancing techniques such as the use of a lipophilic receptor solution, removal of stratum corneum and delipidization of skin. Their k' values were proportional to the degree of carbon-carbon saturation in the side chain. All these fatty esters were highly stable in 2-propanol, acetonitrile and glycerin, but unstable in methanol and ethanol. They were relatively unstable in liver and skin homogenates. In particular, C16SA was mostly hydrolyzed to its parent compound in hairless mouse liver and skin homogenates, suggesting that it might be converted to salicylic acid after its topical administration. In the skin permeation and accumulation study, C16SA showed the poorest permeation in all skins, suggesting that it could not be permeated in the skin. Furthermore, C14SA and C16SA were less accumulated in delipidized skin compared with normal skin or stripped skin, suggesting that these esters had relatively strong affinities for lipids compared with the other prodrugs in the skin. C16SA showed significantly higher dermal accumulation in all skins compared with its parent salicylic acid. Thus, the palmitoyl oxysalicylate (C16SA) might be a potential candidate for UV protection due to its absence of skin permeation, smaller uptake in the lipid phase and relatively lower skin accumulation.

  8. Association of angiotensin-converting-enzyme gene polymorphism with the depressor response to mild exercise therapy in patients with mild to moderate essential hypertension.

    PubMed

    Zhang, B; Sakai, T; Miura, S; Kiyonaga, A; Tanaka, H; Shindo, M; Saku, K

    2002-10-01

    We studied the association of angiotensin I-converting enzyme (ACE) gene polymorphism with the depressor response to exercise therapy in 64 Japanese subjects with mild to moderate essential hypertension. Each subject performed 10 weeks of mild (lactate threshold intensity: approximately 50% maximum oxygen consumption) exercise therapy on a bicycle ergometer. Systolic blood pressure (SPB), diastolic blood pressure (DPB), and mean arterial pressure (MAP) were significantly decreased by exercise therapy in subjects with the ACE-II and ID genotypes but not in DD subjects. The time-by-genotype interaction effects were significant for DBP and MAP. According to a multiple logistic regression analysis, the age- and baseline plasma renin activity-adjusted relative risk (odds ratio) for the lack of a depressor response conferred by the D allele (assuming an additive effect) was 2.72 [95% confidence interval (CI), 1.07-6.91; p = 0.034]; for DD genotypes, as compared with the DI and II genotypes (assuming that the D allele is recessive), it was 11.7 (95% CI, 2.25-60.6; p = 0.003). ACE gene I/D polymorphism is associated with the depressor response of essential hypertensives to mild exercise therapy, which suggests that genetic features may underlie, at least in part, the heterogeneity of the depressor response in essential hypertensives to mild exercise therapy.

  9. Discovery and Characterization of a Water-Soluble Prodrug of a Dual Inhibitor of Bacterial DNA Gyrase and Topoisomerase IV.

    PubMed

    O'Dowd, Hardwin; Shannon, Dean E; Chandupatla, Kishan R; Dixit, Vaishali; Engtrakul, Juntyma J; Ye, Zhengqi; Jones, Steven M; O'Brien, Colleen F; Nicolau, David P; Tessier, Pamela R; Crandon, Jared L; Song, Bin; Macikenas, Dainius; Hanzelka, Brian L; Le Tiran, Arnaud; Bennani, Youssef L; Charifson, Paul S; Grillot, Anne-Laure

    2015-07-09

    Benzimidazole 1 is the lead compound resulting from an antibacterial program targeting dual inhibitors of bacterial DNA gyrase and topoisomerase IV. With the goal of improving key drug-like properties, namely, the solubility and the formulability of 1, an effort to identify prodrugs was undertaken. This has led to the discovery of a phosphate ester prodrug 2. This prodrug is rapidly cleaved to the parent drug molecule upon both oral and intravenous administration. The prodrug achieved equivalent exposure of 1 compared to dosing the parent in multiple species. The prodrug 2 has improved aqueous solubility, simplifying both intravenous and oral formulation.

  10. Supramolecular curcumin-barium prodrugs for formulating with ceramic particles.

    PubMed

    Kamalasanan, Kaladhar; Anupriya; Deepa, M K; Sharma, Chandra P

    2014-10-01

    A simple and stable curcumin-ceramic combined formulation was developed with an aim to improve curcumin stability and release profile in the presence of reactive ceramic particles for potential dental and orthopedic applications. For that, curcumin was complexed with barium (Ba(2+)) to prepare curcumin-barium (BaCur) complex. Upon removal of the unbound curcumin and Ba(2+) by dialysis, a water-soluble BaCur complex was obtained. The complex was showing [M+1](+) peak at 10,000-20,000 with multiple fractionation peaks of MALDI-TOF-MS studies, showed that the complex was a supramolecular multimer. The (1)H NMR and FTIR studies revealed that, divalent Ba(2+) interacted predominantly through di-phenolic groups of curcumin to form an end-to-end complex resulted in supramolecular multimer. The overall crystallinity of the BaCur was lower than curcumin as per XRD analysis. The complexation of Ba(2+) to curcumin did not degrade curcumin as per HPLC studies. The fluorescence spectrum was blue shifted upon Ba(2+) complexation with curcumin. Monodisperse nanoparticles with size less than 200dnm was formed, out of the supramolecular complex upon dialysis, as per DLS, and upon loading into pluronic micelles the size was remaining in similar order of magnitude as per DLS and AFM studies. Stability of the curcumin was improved greater than 50% after complexation with Ba(2+) as per UV/Vis spectroscopy. Loading of the supramloecular nanoparticles into pluronic micelles had further improved the stability of curcumin to approx. 70% in water. These BaCur supramolecule nanoparticles can be considered as a new class of prodrugs with improved solubility and stability. Subsequently, ceramic nanoparticles with varying chemical composition were prepared for changing the material surface reactivity in terms of the increase in, degradability, surface pH and protein adsorption. Further, these ceramic particles were combined with curcumin prodrug formulations and optimized the curcumin release

  11. Role of cardiac MRI in evaluating patients with Anderson-Fabry disease: assessing cardiac effects of long-term enzyme replacement therapy.

    PubMed

    Messalli, G; Imbriaco, M; Avitabile, G; Russo, R; Iodice, D; Spinelli, L; Dellegrottaglie, S; Cademartiri, F; Salvatore, M; Pisani, A

    2012-02-01

    Anderson-Fabry disease is a multisystemic disorder of lipid metabolism secondary to X-chromosome alterations and is frequently associated with cardiac manifestations such as left ventricular (LV) hypertrophy, gradually leading to an alteration in cardiac performance. The purpose of this study was to monitor, using magnetic resonance imaging (MRI), any changes produced by enzyme replacement therapy with agalsidase beta at the cardiac level in patients with Anderson-Fabry disease. Sixteen (ten men, six women) patients with genetically confirmed Anderson-Fabry disease underwent cardiac MRI before starting enzyme replacement therapy (baseline study) and after 48 months of treatment with agalsidase beta at the dose of 1 mg/kg (follow-up study). After 48 months of treatment, a significant reduction in LV mass and wall thickness was observed: 187±59 g vs. 149±44 g, and 16±3 mm vs. 13±3 mm, respectively. A significant reduction in T2 relaxation time was noted at the level of the interventricular septum (81±3 ms vs. 67±7 ms), at the apical level (80±8 ms vs. 63±6 ms) and at the level of the lateral wall (82±8 ms vs. 63±10 ms) (p<0.05). No significant variation was observed in ejection fraction between the two studies (65±3% vs. 64±2%; p>0.05) (mean bias 1.0); however, an improvement was noted in the New York Heart Association (NYHA) class of the majority of patients (12/16) (p<0.05). In patients with Anderson-Fabry disease undergoing enzyme replacement therapy with agalsidase beta, MRI documented a significant reduction in myocardial T2 relaxation time, a significant decrease in maximal myocardial thickness and in total LV mass. MRI did not reveal significant improvements in LV global systolic function; however, improvement in NYHA functional class was noted, consistent with improved diastolic function.

  12. Enzyme replacement therapy in a patient with Fabry disease and the development of IgE antibodies against agalsidase beta but not agalsidase alpha.

    PubMed

    Tanaka, Akemi; Takeda, Taisuke; Hoshina, Takao; Fukai, Kazuyoshi; Yamano, Tsunekazu

    2010-12-01

    Fabry disease is an X-linked inherited lysosomal storage disorder caused by an inborn deficiency of the enzyme α-galactosidase A. Enzyme replacement therapy (ERT) with agalsidase alpha or beta isozymes is an effective treatment. Cross-reactivity of immunoglobulin G (IgG) antibodies with agalsidase alpha and beta has been reported, but no such reaction has been recorded for IgE antibodies. We present the case of a patient with Fabry disease who developed antiagalsidase beta IgE antibodies without cross-reactivity to agalsidase alpha. A 17-year-old boy with Fabry disease had suffered from severe atopic dermatitis since infancy, and he complained for several years of peripheral pain during the summer months and when exercising. Fabry disease was confirmed by family history and a positive enzyme test, and ERT was commenced. Following infusion of agalsidase beta (1.0 mg/kg), the patient complained of a high temperature in his hands and feet, and purulent eczema developed. The infusion dose was reduced to 0.2 mg/kg, but the hyperthermia did not change, although its duration decreased. After three infusions, eosinophilia developed (9.4%; 573 cells/μl blood) and remained unresolved after four infusions with agalsidase beta. Treatment with this enzyme was discontinued, and agalsidase alpha (0.2 mg/kg) started. This produced immediate resolution of the eosinophilia, which has been maintained during follow-up. In conclusion, this patient developed IgE antibodies against agalsidase beta, which demonstrated no cross-reactivity to agalsidase alpha. These findings emphasize the importance of analyzing IgE antibodies against both enzymes when patients exhibit severe infusion-related events.

  13. Intracellular implantation of enzymes in hollow silica nanospheres for protein therapy: cascade system of superoxide dismutase and catalase.

    PubMed

    Chang, Feng-Peng; Chen, Yi-Ping; Mou, Chung-Yuan

    2014-11-01

    An approach for enzyme therapeutics is elaborated with cell-implanted nanoreactors that are based on multiple enzymes encapsulated in hollow silica nanospheres (HSNs). The synthesis of HSNs is carried out by silica sol-gel templating of water-in-oil microemulsions so that polyethyleneimine (PEI) modified enzymes in aqueous phase are encapsulated inside the HSNs. PEI-grafted superoxide dismutase (PEI-SOD) and catalase (PEI-CAT) encapsulated in HSNs are prepared with quantitative control of the enzyme loadings. Excellent activities of superoxide dismutation by PEI-SOD@HSN are found and transformation of H2 O2 to water by PEI-CAT@HSN. When PEI-SOD and PEI-CAT are co-encapsulated, cascade transformation of superoxide through hydrogen peroxide to water was facile. Substantial fractions of HSNs exhibit endosome escape to cytosol after their delivery to cells. The production of downstream reactive oxygen species (ROS) and COX-2/p-p38 expression show that co-encapsulated SOD/CAT inside the HSNs renders the highest cell protection against the toxicant N,N'-dimethyl-4,4'-bipyridinium dichloride (paraquat). The rapid cell uptake and strong detoxification effect on superoxide radicals by the SOD/CAT-encapsulated hollow mesoporous silica nanoparticles demonstrate the general concept of implanting catalytic nanoreactors in biological cells with designed functions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. The Evaluation Of Therapeutic Efficacy and Safety Profile of Simvastatin Prodrug Micelles in a Closed Fracture Mouse Model

    PubMed Central

    Zhang, Yijia; Jia, Zhenshan; Yuan, Hongjiang; Dusad, Anand; Ren, Ke; Wei, Xin; Fehringer, Edward V.; Purdue, P. Edward; Daluiski, Aaron; Goldring, Steven R.; Wang, Dong

    2016-01-01

    Purpose To evaluate the therapeutic efficiency of a micellar prodrug formulation of simvastatin (SIM/SIM-mPEG) and explore its safety in a closed femoral fracture mouse model. Methods The amphiphilic macromolecular prodrug of simvastatin (SIM-mPEG) was synthesized and formulated together with free simvastatin into micelles. It was also labeled with a near infrared dye for in vivo imaging purpose. A closed femoral fracture mouse model was established using a three-point bending device. The mice with established closed femoral fracture were treated with SIM/SIM-mPEG micelle, using free simvastatin and saline as controls. The therapeutic efficacy of the micelles was evaluated using a high-resolution micro-CT. Serum biochemistry and histology analyses were performed to explore the potential toxicity of the micelle formulation. Results Near Infrared Fluorescence (NIRF) imaging confirmed the passive targeting of SIM/SIM-mPEG micelles to the bone lesion of the mice with closed femoral fracture. The micelle was found to promote fracture healing with an excellent safety profile. In addition, the accelerated healing of the femoral fracture also helped to prevent disuse-associated same-side tibia bone loss accompanying the femur fracture. Conclusion SIM/SIM-mPEG micelle was found to be an effective and safe treatment for closed femoral fracture repair in mice. The evidence obtained in this study suggests that it may have the potential to be translated into a novel therapy for clinical management of skeletal fractures and non-union. PMID:27164897

  15. Design, Synthesis, and Pharmacokinetics of a Bone-Targeting Dual-Action Prodrug for the Treatment of Osteoporosis.

    PubMed

    Xie, Haibo; Chen, Gang; Young, Robert N

    2017-08-24

    A dual-action bone-targeting prodrug has been designed, synthesized, and evaluated for in vitro and in vivo metabolic stability, in vivo tissue distribution, and rates of release of the active constituents after binding to bones through the use of differentially double-labeled derivatives. The conjugate (general structure 7) embodies the merger of a very potent and proven anabolic selective agonist of the prostaglandin EP4 receptor, compound 5, and alendronic acid, a potent inhibitor of bone resorption, optimally linked through a differentially hydrolyzable linker unit, N-4-carboxymethylphenyl-methyloxycarbonyl-leucinyl-argininyl-para-aminophenylmethylalcohol (Leu-Arg-PABA). Optimized conjugate 16 was designed so that esterase activity will liberate 5 and cathepsin K cleavage of the Leu-Arg-PABA element will liberate alendronic acid. Studies with doubly radiolabeled 16 provide a proof-of-concept for the use of a cathepsin K cleavable peptide-linked conjugate for targeting of bisphosphonate prodrugs to bone and slow release liberation of the active constituents in vivo. Such conjugates are potential therapies for the treatment of bone disorders such as osteoporosis.

  16. Enzyme Kinetics in Microgravity

    NASA Astrophysics Data System (ADS)

    Liu, C. C.; Licata, V. J.

    2010-04-01

    The kinetics of some enzymes have been found to be enhanced by the microgravity environment. This is a relatively small effect, but is sufficient to have physiological effects and to impact pharmaceutical therapy in microgravity.

  17. A prodrug approach to enhance azelaic acid percutaneous availability.

    PubMed

    Al-Marabeh, Sara; Khalil, Enam; Khanfar, Mohammad; Al-Bakri, Amal G; Alzweiri, Muhammed

    2017-06-01

    Azelaic acid is a dicarboxylic acid compound used in treatment of acne vulgaris. However, high concentration (ca 20%) is needed to guarantee the drug availability in the skin. The latter increases the incidence of side effects such as local irritation. The prodrug strategy to enhance azelaic acid diffusion through skin was not reported before. Thus, a lipophilic prodrug of azelaic acid (diethyl azelate [DEA]) was synthesized and investigated to improve percutaneous availability of azelaic acid, with a subsequent full physical, chemical, and biological characterization. Expectedly, DEA exhibited a significant increase in diffusion compared to azelaic acid through silicone membrane. In contrast, the diffusion results through human stratum corneum (SC) displayed weaker permeation for DEA with expected retention in the SC. Therefore, a desorption study of DEA from SC was conducted to examine the reservoir behavior in SC. Results showed an evidence of sustained release behavior of DEA from SC. Consequently, enhancement of keratolytic effect is expected due to azelaic acid produced from enzymatic conversion of DEA released from SC.

  18. Mutual Amide Prodrug of Etodolac-glucosamine: Synthesis, Characterization and Pharmacological Screening

    PubMed Central

    Pandey, Preeti; Pandey, S.; Dubey, Shaifali

    2013-01-01

    Etodolac, a nonsteroidal antiinflammatory drug, widely used in arthritis is associated with gastric ulceration and irritation due to presence of free carboxylic group. The current investigation reports synthesis of mutual amide prodrug of etodolac by masking free carboxylic group with glucosamine, a nutritional supplement for treatment of arthritis. Confirmation and characterization of the structure of the synthesized prodrug done by elemental and spectroscopy analysis, melting point, determination of migration parameters (Rf, RM, and Rt) by using thin layer chromatography and high performance liquid chromatography, respectively. Partition coefficient and solubility study confirms its lipophilic character so can be suitable candidate for controlled release delivery. In vitro hydrolytic studies of prodrug confirms good rate of hydrolysis in blood plasma, fecal matter, and simulated intestinal fluid while stable in gastric simulated fluid. In vivo pharmacological screening performed on animals. Prodrug with respect to etodolac shows good analgesic, antiinflammatory, and antiarthritic activity. The prodrug was assessed for their probable damaging effects by ulcerogeniticity and histopathological analysis. The histopathological studies showed less ulceration in the gastric region when treated with prodrug, thereby proving the prodrug to be better in action as compared to etodolac and are advantageous in having less gastrointestinal side effects. PMID:24302794

  19. Glutathione S-conjugates as prodrugs to target drug-resistant tumors

    PubMed Central

    Ramsay, Emma E.; Dilda, Pierre J.

    2014-01-01

    Living organisms are continuously exposed to xenobiotics. The major phase of enzymatic detoxification in many species is the conjugation of activated xenobiotics to reduced glutathione (GSH) catalyzed by the glutathione-S-transferase (GST). It has been reported that some compounds, once transformed into glutathione S-conjugates, enter the mercapturic acid pathway whose end products are highly reactive and toxic for the cell responsible for their production. The cytotoxicity of these GSH conjugates depends essentially on GST and gamma-glutamyl transferases (γGT), the enzymes which initiate the mercapturic acid synthesis pathway. Numerous studies support the view that the expression of GST and γGT in cancer cells represents an important factor in the appearance of a more aggressive and resistant phenotype. High levels of tumor GST and γGT expression were employed to selectively target tumor with GST- or γGT-activated drugs. This strategy, explored over the last two decades, has recently been successful using GST-activated nitrogen mustard (TLK286) and γGT-activated arsenic-based (GSAO and Darinaparsin) prodrugs confirming the potential of GSH-conjugates as anticancer drugs. PMID:25157234

  20. Design of Enzymatically Cleavable Prodrugs of a Potent Platinum-Containing Anticancer Agent

    PubMed Central

    Ding, Song; Pickard, Amanda J.; Kucera, Gregory L.

    2014-01-01

    Using a versatile synthetic approach, a new class of potential ester prodrugs of highly potent, but systemically too toxic, platinum–acridine anticancer agents was generated. The new hybrids contain a hydroxyl group, which has been masked with a cleavable lipophilic acyl moiety. Both butanoic (butyric) and bulkier 2-propanepentanoic (valproic) esters were introduced. The goals of this design were to improve the drug-like properties (e.g., logD) and to reduce the systemic toxicity of the pharmacophore. Two distinct pathways by which the target compounds undergo effective ester hydrolysis, the proposed activating step, have been confirmed: platinum-assisted, self-immolative ester cleavage in a low-chloride environment (LC-ESMS, NMR spectroscopy) and enzymatic cleavage by human carboxylesterase-2 (hCES-2) (LC-ESMS). The valproic acid ester derivatives are the first example of a metal-containing agent cleavable by the pro-drug-converting enzyme. They show excellent chemical stability and reduced systemic toxicity. Preliminary results from screening in lung adenocarcinoma cell lines (A549, NCI-H1435) suggest that the mechanism of the valproic esters may involve intracellular deesterification. PMID:25303639

  1. para-Aminosalicylic acid is a prodrug targeting dihydrofolate reductase in Mycobacterium tuberculosis.

    PubMed

    Zheng, Jun; Rubin, Eric J; Bifani, Pablo; Mathys, Vanessa; Lim, Vivian; Au, Melvin; Jang, Jichan; Nam, Jiyoun; Dick, Thomas; Walker, John R; Pethe, Kevin; Camacho, Luis R

    2013-08-09

    para-Aminosalicylic acid (PAS) is one of the antimycobacterial drugs currently used for multidrug-resistant tuberculosis. Although it has been in clinical use for over 60 years, its mechanism(s) of action remains elusive. Here we report that PAS is a prodrug targeting dihydrofolate reductase (DHFR) through an unusual and novel mechanism of action. We provide evidences that PAS is incorporated into the folate pathway by dihydropteroate synthase (DHPS) and dihydrofolate synthase (DHFS) to generate a hydroxyl dihydrofolate antimetabolite, which in turn inhibits DHFR enzymatic activity. Interestingly, PAS is recognized by DHPS as efficiently as its natural substrate para-amino benzoic acid. Chemical inhibition of DHPS or mutation in DHFS prevents the formation of the antimetabolite, thereby conferring resistance to PAS. In addition, we identified a bifunctional enzyme (riboflavin biosynthesis protein (RibD)), a putative functional analog of DHFR in a knock-out strain. This finding is further supported by the identification of PAS-resistant clinical isolates encoding a RibD overexpression mutation displaying cross-resistance to genuine DHFR inhibitors. Our findings reveal that a metabolite of PAS inhibits DHFR in the folate pathway. RibD was shown to act as a functional analog of DHFR, and as for DHFS, both were shown to be associated in PAS resistance in laboratory strains and clinical isolates.

  2. Electrospun poly-l-lactide scaffold for the controlled and targeted delivery of a synthetically obtained Diclofenac prodrug to treat actinic keratosis.

    PubMed

    Piccirillo, Germano; Bochicchio, Brigida; Pepe, Antonietta; Schenke-Layland, Katja; Hinderer, Svenja

    2017-04-01

    Actinic Keratosis' (AKs) are small skin lesions that are related to a prolonged sun-damage, which can develop into invasive squamous cell carcinoma (SCC) when left untreated. Effective, specific and well tolerable therapies to cure AKs are still of great interest. Diclofenac (DCF) is the current gold standard for the local treatment of AKs in terms of costs, effectiveness, side effects and tolerability. In this work, an electrospun polylactic acid (PLA) scaffold loaded with a synthetic DCF prodrug was developed and characterized. Specifically, the prodrug was successfully synthetized by binding DCF to a glycine residue via solid phase peptide synthesis (SPPS) and then incorporated in an electrospun PLA scaffold. The drug encapsulation was verified using multiphoton microscopy (MPM) and its scaffold release was spectrophotometrically monitored and confirmed with MPM. The scaffold was further characterized with scanning electron microscopy (SEM), tensile testing and contact angle measurements. Its biocompatibility was verified by performing a cell proliferation assay and compared to PLA scaffolds containing the same amount of DCF sodium salt (DCFONa). Finally, the effect of the electrospun scaffolds on human dermal fibroblasts (HDFs) morphology and metabolism was investigated by combining MPM with fluorescence lifetime imaging microscopy (FLIM). The obtained results suggest that the obtained scaffold could be suitable for the controlled and targeted delivery of the synthesized prodrug for the treatment of AKs. Electrospun scaffolds are of growing interest as materials for a controlled drug delivery. In this work, an electrospun polylactic acid scaffold containing a synthetically obtained Diclofenac prodrug is proposed as a novel substrate for the topical treatment of actinic keratosis. A controlled drug delivery targeted to the area of interest could enhance the efficacy of the therapy and favor the healing process. The prodrug was synthesized via solid phase

  3. Successful reinstitution of agalsidase beta therapy in Fabry disease patients with previous IgE-antibody or skin-test reactivity to the recombinant enzyme.

    PubMed

    Bodensteiner, David; Scott, C Ronald; Sims, Katherine B; Shepherd, Gillian M; Cintron, Rebecca D; Germain, Dominique P

    2008-05-01

    To determine if enzyme replacement therapy, involving intravenous infusions of recombinant human alpha-galactosidase A (agalsidase beta; Fabrazyme), could be safely continued in patients with Fabry disease who had been withdrawn from a previous clinical trial as a precautionary, protocol-specified measure due to detection of serum IgE antibodies or skin-test reactivity to agalsidase beta. The rechallenge infusion protocol specified strict patient monitoring conditions and graded dosing and infusion-rate schemes that were adjusted according to each patient's tolerance to the infusion. Six males (age: 26-66 years) were enrolled. During rechallenge, five patients received between 4 and 27 infusions; one patient voluntarily withdrew after one infusion because of recurrence of infusion-associated reactions. No anaphylactic reactions occurred. All adverse events, including four serious adverse events, were mild or moderate in intensity. Most treatment-related adverse events occurred during infusions (most commonly urticaria, vomiting, nausea, chills, pruritus, hypertension) and were resolved by infusion rate reductions and/or medication. After participation in the study, all patients, including the one who withdrew after one infusion, transitioned to commercial drug. Agalsidase beta therapy can be successfully reinstated in patients with Fabry disease who have developed IgE antibodies or skin test reactivity to the recombinant enzyme.

  4. Effect of anti-tuberculosis therapy on polymorphic drug metabolizing enzyme CYP2C9 using phenytoin as a probe drug

    PubMed Central

    George, Melvin; Shewade, Deepak Gopal; Kumar, Saka Vinod; Adithan, Chandrasekaran

    2012-01-01

    Objectives: Patients on anti-tuberculosis therapy (ATT) are more prone to drug interactions in the presence of coexisting illnesses which warrant drug therapy. Rifampicin is a strong CYP enzyme inducer while isoniazid is a potent CYP inhibitor. The objective of the study was to find the net effect of one month ATT on CYP2C9 enzyme and to correlate it with respect to the CYP2C9 genetic polymorphisms. Materials and Methods: Forty eight newly diagnosed tuberculosis patients were included in the study based on the inclusion-exclusion criteria. Before commencing ATT, they were given a single dose of phenytoin 300 mg as a probe drug for CYP2C9. Blood sample was collected after three hours to carry out CYP2C9 genotyping by PCR-RFLP method. Phenotyping for CYP2C9 enzyme was done by measuring the ratio of phenytoin and its metabolite p-HPPH (para hydroxy phenyl hydantoin) by reverse phase HPLC (high performance liquid chromatography) method before and after one month of ATT. Results: In the CYP2C9*1*1 genotype, the mean plasma concentrations of phenytoin before and after one month of ATT were 5.2 ± 0.3 μg/ml and 3.5 ± 0.4 μg/ml respectively, a reduction by 33% showing significant induction (P < 0.001). There was also significant decrease in the metabolic ratio after one month of ATT from 23.2 ± 4.8 to 10.1 ± 1.9 (P < 0.001). The metabolic ratio was also observed to reduce significantly (P < 0.05) when the CYP2C9*1*2, CYP2C9*1*3, and CYP2C9*3*3 data were pooled together. Conclusion: The presence of polymorphisms in the CYP2C9 gene does not affect the induction potential of ATT. PMID:23087510

  5. Successful management of enzyme replacement therapy in related fabry disease patients with severe adverse events by switching from agalsidase Beta (fabrazyme(®)) to agalsidase alfa (replagal (®)).

    PubMed

    Tsuboi, Kazuya; Yamamoto, Hiroshi; Somura, Fuji; Goto, Hiromi

    2015-01-01

    Enzyme replacement therapy (ERT) is the only approved therapy for Fabry disease. In June 2009, there was a worldwide shortage of agalsidase beta, necessitating dose reductions or switching to agalsidase alfa in some patients. We present two cases of Fabry disease (a parent and a child) who received agalsidase beta for 27 months at the licensed dose and 10 months at a reduced dose, followed by a switch to agalsidase alfa for 28 months. Case 1, a 26-year-old male had severe coughing and fatigue during ERT with agalsidase beta requiring antitussive and asthmatic drug therapy. After switching to agalsidase alfa, the coughing gradually resolved completely. Case 2, a 62-year-old female had advanced cardiac manifestations at the time of diagnosis. Despite receiving ERT with the approved dose of agalsidase beta, she experienced aggravation of congestive heart failure and was hospitalized. After switching to agalsidase alfa with standard care in heart disease, BNP level, echocardiographic parameters, eGFR rate and lyso-Gb3 levels were improved or stabilized. We report on two Fabry disease patients who experienced severe adverse events while on approved and/or reduced doses of agalsidase beta. Switching to agalsidase alfa associated with standard care in heart disease led to resolution or improvement in the cardiorespiratory status. And reduction in dose associated with standard care in respiratory disease was useful for decrease in cough and fatigue. Plasma BNP level was useful for monitoring heart failure and the effects of ERT.

  6. Comparison of gallium-67 scanning, bronchoalveolar lavage, and serum angiotensin-converting enzyme levels in pulmonary sarcoidosis. Predicting response to therapy

    SciTech Connect

    Baughman, R.P.; Fernandez, M.; Bosken, C.H.

    1984-05-01

    Patients with active pulmonary sarcoidosis underwent bronchoalveolar lavage, gallium scan, and serum angiotensin-converting enzyme (ACE) level determination prior to treatment with corticosteroids. Pulmonary function was tested before and after therapy. Increase in vital capacity after treatment ranged from 40 to 1,030 ml; 12 of the 16 patients studied had an increase of more than 200 ml. There was a close correlation between the percentage uptake of gallium scan and the increase of the vital capacity after therapy (r . 0.95, p less than 0.01). There was no relationship between the percentage of lymphocytes obtained on lavage and the changes inmore » vital capacity with therapy (r . 0.05). There was a positive correlation between the changes in vital capacity and the ratio of T4(+):T8(+)lymphocytes (r . 0.62, p less than 0.05) and number of T4 (+) lymphocytes (r . 0.92, p less than 0.01) in the bronchoalveolar fluid. There was a low correlation between the pretreatment ACE level and the change in vital capacity (r . 0.368, p greater than 0.05).« less

  7. Targeted theranostic platinum(IV) prodrug with a built-in aggregation-induced emission light-up apoptosis sensor for noninvasive early evaluation of its therapeutic responses in situ.

    PubMed

    Yuan, Youyong; Kwok, Ryan T K; Tang, Ben Zhong; Liu, Bin

    2014-02-12

    Targeted drug delivery to tumor cells with minimized side effects and real-time in situ monitoring of drug efficacy is highly desirable for personalized medicine. In this work, we report the synthesis and biological evaluation of a chemotherapeutic Pt(IV) prodrug whose two axial positions are functionalized with a cyclic arginine-glycine-aspartic acid (cRGD) tripeptide for targeting integrin αvβ3 overexpressed cancer cells and an apoptosis sensor which is composed of tetraphenylsilole (TPS) fluorophore with aggregation-induced emission (AIE) characteristics and a caspase-3 enzyme specific Asp-Glu-Val-Asp (DEVD) peptide. The targeted Pt(IV) prodrug can selectively bind to αvβ3 integrin overexpressed cancer cells to facilitate cellular uptake. In addition, the Pt(IV) prodrug can be reduced to active Pt(II) drug in cells and release the apoptosis sensor TPS-DEVD simultaneously. The reduced Pt(II) drug can induce the cell apoptosis and activate caspase-3 enzyme to cleave the DEVD peptide sequence. Due to free rotation of the phenylene rings, TPS-DEVD is nonemissive in aqueous media. The specific cleavage of DEVD by caspase-3 generates the hydrophobic TPS residue, which tends to aggregate, resulting in restriction of intramolecular rotations of the phenyl rings and ultimately leading to fluorescence enhancement. Such noninvasive and real-time imaging of drug-induced apoptosis in situ can be used as an indicator for early evaluation of the therapeutic responses of a specific anticancer drug.

  8. Development and characterization of nanoparticulate formulation of a water soluble prodrug of dexamethasone by HIP complexation.

    PubMed

    Gaudana, Ripal; Parenky, Ashwin; Vaishya, Ravi; Samanta, Swapan K; Mitra, Ashim K

    2011-01-01

    The objective of this study was to develop and characterize a nanoparticulate-based sustained release formulation of a water soluble dipeptide prodrug of dexamethasone, valine-valine-dexamethasone (VVD). Being hydrophilic in nature, it readily leaches out in the external aqueous medium and hence partitions poorly into the polymeric matrix resulting in minimal entrapment in nanoparticles. Hence, hydrophobic ion pairing (HIP) complexation of the prodrug was employed with dextran sulphate as a complexing polymer. A novel, solid in oil in water emulsion method was employed to encapsulate the prodrug in HIP complex form in poly(lactic-co-glycolic acid) matrix. Nanoparticles were characterized with respect to size, zeta potential, crystallinity of entrapped drug and surface morphology. A significant enhancement in the entrapment of the prodrug in nanoparticles was achieved. Finally, a simple yet novel method was developed which can also be applicable to encapsulate other charged hydrophilic molecules, such as peptides and proteins.

  9. Development and characterization of nanoparticulate formulation of a water soluble prodrug of dexamethasone by HIP complexation

    PubMed Central

    Gaudana, Ripal; Parenky, Ashwin; Vaishya, Ravi; Samanta, Swapan K.; Mitra, Ashim K.

    2015-01-01

    The objective of this study was to develop and characterize a nanoparticulate-based sustained release formulation of a water soluble dipeptide prodrug of dexamethasone, valine–valine-dexamethasone (VVD). Being hydrophilic in nature, it readily leaches out in the external aqueous medium and hence partitions poorly into the polymeric matrix resulting in minimal entrapment in nanoparticles. Hence, hydrophobic ion pairing (HIP) complexation of the prodrug was employed with dextran sulphate as a complexing polymer. A novel, solid in oil in water emulsion method was employed to encapsulate the prodrug in HIP complex form in poly(lactic-co-glycolic acid) matrix. Nanoparticles were characterized with respect to size, zeta potential, crystallinity of entrapped drug and surface morphology. A significant enhancement in the entrapment of the prodrug in nanoparticles was achieved. Finally, a simple yet novel method was developed which can also be applicable to encapsulate other charged hydrophilic molecules, such as peptides and proteins. PMID:20939702

  10. PARP Inhibitor and NO-Donor Dual Prodrugs as Anticancer Agents | NCI Technology Transfer Center | TTC

    Cancer.gov

    The National Cancer Institute’s Chemical Biology Laboratory seeks partners interested in collaborative research to co-develop PARP inhibitor and NO-donor hybrid prodrugs for the treatment of cancer.

  11. Re-engineering Cytochrome P450 2B11dH for Enhanced Metabolism of Several Substrates Including the Anti-cancer Prodrugs Cyclophosphamide and Ifosfamide

    PubMed Central

    Sun, Ling; Chen, Chong S.; Waxman, David J.; Liu, Hong; Halpert, James R.; Kumar, Santosh

    2007-01-01

    Based on recent directed evolution of P450 2B1, six P450 2B11 mutants at three positions were created in an N-terminal modified construct termed P450 2B11dH and characterized for enzyme catalysis using five substrates. Mutant I209A demonstrated a 3.2-fold enhanced kcat/Km for 7-ethoxy-4-trifluoromethylcourmarin O-deethylation, largely due to a dramatic decrease in Km (0.72 vs. 18 μM). I209A also demonstrated enhanced selectivity for testosterone 16β-hydroxylation over 16α-hydroxylation. In contrast, V183L showed a 4-fold increased kcat for 7-benzyloxyresorufin debenzylation and a 4.7-fold increased kcat/Km for testosterone 16α-hydroxylation. V183L also displayed a 1.7-fold higher kcat/Km than P450 2B11dH with the anti-cancer prodrugs cyclophosphamide and ifosfamide, resulting from a ~4-fold decrease in Km. Introduction of the V183L mutation into full-length P450 2B11 did not enhance the kcat/Km. Overall, the re-engineered P450 2B11dH enzymes exhibited enhanced catalytic efficiency with several substrates including the anti-cancer prodrugs. PMID:17254539

  12. Novel prodrugs of tegafur that display improved anticancer activity and antiangiogenic properties.

    PubMed

    Engel, Dikla; Nudelman, Abraham; Tarasenko, Nataly; Levovich, Inesa; Makarovsky, Igor; Sochotnikov, Segev; Tarasenko, Igor; Rephaeli, Ada

    2008-01-24

    New and more potent prodrugs of the 5-fluorouracyl family derived by hydroxymethylation or acyloxymethylation of 5-fluoro-1-(tetrahydro-2-furanyl)-2,4(1H,3H)-pyrimidinedione (tegafur, 1) are described. The anticancer activity of the butyroyloxymethyl-tegafur derivative 3 and not that of tegafur was attenuated by the antioxidant N-acetylcysteine, suggesting that the increased activity of the prodrug is in part mediated by an increase of reactive oxygen species. Compound 3 in an in vitro matrigel assay was found to be a more potent antiangiogenic agent than tegafur. In vivo 3 was significantly more potent than tegafur in inhibiting 4T1 breast carcinoma lung metastases and growth of HT-29 human colon carcinoma tumors in a mouse xenograft. In summary, the multifunctional prodrugs of tegafur display selectivity toward cancer cells, antiangiogenic activity, and anticancer activities in vitro and in vivo, superior to those of tegafur. 5-fluoro-1-(tetrahydro-2-furanyl)-2,4(1 H,3 H)-pyrimidinedione (tegafur, 1), the oral prodrug of 5-FU, has been widely used for treatment of gastrointestinal malignancies with modest efficacy. The aim of this study was to develop and characterize new and more potent prodrugs of the 5-FU family derived by hydroxymethylation or acyloxymethylation of tegafur. Comparison between the effect of tegafur and the new prodrugs on the viability of a variety of cancer cell lines showed that the IC50 and IC90 values of the novel prodrugs were 5-10-fold lower than those of tegafur. While significant differences between the IC50 values of tegafur were observed between the sensitive HT-29 and the resistant LS-1034 colon cancer cell lines, the prodrugs affected them to a similar degree, suggesting that they overcame drug resistance. The increased potency of the prodrugs could be attributed to the antiproliferative contribution imparted by formaldehyde and butyric acid, released upon metabolic degradation. The anticancer activity of the butyroyloxymethyl

  13. Synthesis and anti-cancer efficacy of rapid hydrolysed water-soluble paclitaxel pro-drugs.

    PubMed

    Ryu, Beom-Young; Sohn, Jeong-Sun; Hess, Michael; Choi, Soo-Kyung; Choi, Jae-Kon; Jo, Byung-Wook

    2008-01-01

    A new series of poly(ethylene glycol)(PEG)-paclitaxel conjugates that increases water solubility of paclitaxel was synthesized. We developed well-designed self-immolating linkers between a drug and a water-soluble polymer moiety which gave an extremely rapid hydrolysis rate to convert a pro-drug into a parent drug without any reduction in drug efficacy. The self-immolating spacer groups were introduced between the solubilizing PEG and C7-OH of paclitaxel in order to control the rate of enzymatic hydrolysis. All these pro-drugs had a water-solubility of 400 mg/ml or more compared with a solubility of about 0.01 mg/ml. The rate of hydrolysis for the pro-drugs in rat plasma showed considerable variation of t((1/2)) ranging from 0.94 min to 42.7 min. To evaluate the anti-tumor efficacy of the pro-drug which had the fastest enzymatic hydrolysis rate, the growth inhibitory effect (IC(50)), the anti-tumor activity and the anti-metastatic potential of the pro-drug were examined. The pro-drug was potent to inhibit the growth of various cancer cell lines, such as human lung, ovarian, colon and melanoma cancer cells. On the development of melanoma lung colonies in C57B/6 mice following intravenous administration of metastatic murine B16/F10 melanoma cells, the pro-drug seems to be more efficacious than paclitaxel. The reduction of the number of melanoma lung colonies was 46.9% (dose: 5 mg/kg) with pure paclitaxel, and 24.5%, and 40.0% with the pro-drug in the dose of 0.71 mg paclitaxel equivalent/kg and 1.42 mg paclitaxel equivalent/kg, respectively.

  14. Hypoxia-activated prodrug TH-302 decreased survival rate of canine lymphoma cells under hypoxic condition.

    PubMed

    Yamazaki, Hiroki; Lai, Yu-Chang; Tateno, Morihiro; Setoguchi, Asuka; Goto-Koshino, Yuko; Endo, Yasuyuki; Nakaichi, Munekazu; Tsujimoto, Hajime; Miura, Naoki

    2017-01-01

    We tested the hypotheses that hypoxic stimulation enhances growth potentials of canine lymphoma cells by activating hypoxia-inducible factor 1α (HIF-1α), and that the hypoxia-activated prodrug (TH-302) inhibits growth potentials in the cells. We investigated how hypoxic culture affects the growth rate, chemoresistance, and invasiveness of canine lymphoma cells and doxorubicin (DOX)-resistant lymphoma cells, and influences of TH-302 on survival rate of the cells under hypoxic conditions. Our results demonstrated that hypoxic culture upregulated the expression of HIF-1α and its target genes, including ATP-binding cassette transporter B1 (ABCB1), ATP-binding cassette transporter G2 (ABCG2), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and survivin, and enhanced the growth rate, DOX resistance, and invasiveness of the cells. Additionally, TH-302 decreased the survival rate of the cells under hypoxic condition. Our studies suggest that hypoxic stimulation may advance the tumorigenicity of canine lymphoma cells, favoring malignant transformation. Therefore, the data presented may contribute to the development of TH-302-based hypoxia-targeting therapies for canine lymphoma.

  15. Inhaled Treprostinil-Prodrug Lipid Nanoparticle Formulations Provide Long-Acting Pulmonary Vasodilation.

    PubMed

    Leifer, Franziska G; Konicek, Donna M; Chen, Kuan-Ju; Plaunt, Adam J; Salvail, Dany; Laurent, Charles E; Corboz, Michel R; Li, Zhili; Chapman, Richard W; Perkins, Walter R; S Malinin, Vladimir

    2018-05-23

    Treprostinil (TRE), a prostanoid analogue approved in the USA for the treatment of pulmonary arterial hypertension, requires continuous infusion or multiple dosing sessions per day for inhaled and oral routes of administration due to its short half-life. The inhaled drug is known to induce adverse systemic and local effects including headache, nausea, cough, and throat irritation which may be due at least in part to transiently high drug concentrations in the lungs and plasma immediately following administration [1]. To ameliorate these side effects and reduce dosing frequency we designed an inhaled slow-release TRE formulation. TRE was chemically modified to be an alkyl prodrug (TPD) which was then packaged into a lipid nanoparticle (LNP) carrier. Preclinical screening in a rat model of hypoxia-induced pulmonary vasoconstriction led to selection of a 16-carbon alkyl ester derivative of TRE. The TPD-LNP demonstrated approximately 10-fold lower TRE plasma C max compared to inhaled TRE solution while maintaining an extended vasodilatory effect. The favorable PK profile is attributed to gradual dissociation of TPD from the LNP and subsequent conversion to TRE. Together, this sustained presentation of TRE to the lungs and plasma is consistent with a once- or twice-daily dosing schedule in the absence of high C max -associated adverse events which could provide patients with an improved treprostinil therapy. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Pt(IV) complexes as prodrugs for cisplatin.

    PubMed

    Shi, Yi; Liu, Shu-An; Kerwood, Deborah J; Goodisman, Jerry; Dabrowiak, James C

    2012-02-01

    The antitumor effects of platinum(IV) complexes, considered prodrugs for cisplatin, are believed to be due to biological reduction of Pt(IV) to Pt(II), with the reduction products binding to DNA and other cellular targets. In this work we used pBR322 DNA to capture the products of reduction of oxoplatin, c,t,c-[PtCl(2)(OH)(2)(NH(3))(2)], 3, and a carboxylate-modified analog, c,t,c-[PtCl(2)(OH)(O(2)CCH(2)CH(2)CO(2)H)(NH(3))(2)], 4, by ascorbic acid (AsA) or glutathione (GSH). Since carbonate plays a significant role in the speciation of platinum complexes in solution, we also investigated the effects of carbonate on the reduction/DNA-binding process. In pH 7.4 buffer in the absence of carbonate, both 3 and 4 are reduced by AsA to cisplatin (confirmed using ((195))Pt NMR), which binds to and unwinds closed circular DNA in a manner consistent with the formation of the well-known 1, 2 intrastrand DNA crosslink. However, when GSH is used as the reducing agent for 3 and 4, ((195))Pt NMR shows that cisplatin is not produced in the reaction medium. Although the Pt(II) products bind to closed circular DNA, their effect on the mobility of Form I DNA is different from that produced by cisplatin. When physiological carbonate is present in the reduction medium, ((13))C NMR shows that Pt(II) carbonato complexes form which block or impede platinum binding to DNA. The results of the study vis-à-vis the ability of the Pt(IV) complexes to act as prodrugs for cisplatin are discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Biotransformation Capacity of Carboxylesterase in Skin and Keratinocytes for the Penta-Ethyl Ester Prodrug of DTPA.

    PubMed

    Fu, Jing; Sadgrove, Matthew; Marson, Lesley; Jay, Michael

    2016-08-01

    The penta-ethyl ester prodrug of the chelating agent diethylene triamine pentaacetic acid (DTPA), referred to as C2E5, effectively accelerated clearance of americium after transdermal delivery. Carboxylesterases (CESs) play important roles in facilitating C2E5 hydrolysis. However, whether CESs in human skin hydrolyze C2E5 remains unknown. We evaluated the gene and protein expression of CESs in distinctive human epidermal cell lines: HEKa, HEKn, HaCaT, and A431. The substrates p-nitrophenyl acetate (pNPA) and 4-nitrophenyl valerate (4-NPV) were used to access esterase and CES activity. C2E5 hydrolysis was measured by radiometric high-performance liquid chromatography after incubation of [(14)C]C2E5 with supernatant fractions after centrifugation at 9000g (S9) prepared from skin cell lines. CES-specific inhibitors were used to access metabolism in human skin S9 fractions with analysis by liquid chromatography-tandem mass spectrometry. We identified the human carboxylesterase 1 and 2 (CES1 and CES2) bands in a Western blot. The gene expression of these enzymes was supported by a real-time polymerase chain reaction (qPCR). pNPA and 4-NPV assays demonstrated esterase and CES activity in all the cell lines that were comparable to human skin S9 fractions. The prodrug C2E5 was hydrolyzed by skin S9 fractions, resulting in a primary metabolite, C2E4. In human skin S9 fractions, inhibition of C2E5 hydrolysis was greatest with a pan-CES inhibitor (benzil). CES1 inhibition (troglitazone) was greater than CES2 (loperamide), suggesting a primary metabolic role for CES1. These results indicate that human keratinocyte cell lines are useful for the evaluation of human cutaneous metabolism and absorption of ester-based prodrugs. However, keratinocytes from skin provide a small contribution to the overall metabolism of C2E5. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  18. Enhancement of Curcumin Bioavailability Via the Prodrug Approach: Challenges and Prospects.

    PubMed

    Ratnatilaka Na Bhuket, Pahweenvaj; El-Magboub, Asma; Haworth, Ian S; Rojsitthisak, Pornchai

    2017-06-01

    Curcumin is a natural product with many interesting pharmacological properties. However, these are offset by the particularly poor biopharmaceutical properties. The oral bioavailability of curcumin in humans is very low, mainly due to low solubility, poor stability, and extensive metabolism. This has led to multiple approaches to improve bioavailability, including administration of curcumin with metabolism inhibitors, formulation into nanoparticles, modification of the curcumin structure, and development of curcumin prodrugs. In this paper, we focus on the pharmacokinetic outcomes of these approaches. Pharmacokinetic parameters of curcumin after release from prodrugs are dependent on the linker between curcumin and the promoiety, and the release itself may depend on the physiological and enzymatic environment at the site of cleavage. This is an area in which more data are required for rational design of improved linkers. Cytotoxicity of curcumin prodrugs seems to correlate well with cellular uptake in vitro, but the in vivo relevance is uncertain. We conclude that improved experimental and theoretical models of absorption of curcumin prodrugs, development of accurate analytical methods for simultaneous measurement of plasma levels of prodrug and released curcumin, and acquisition of more pharmacokinetic data in animal models for dose prediction in humans are required to facilitate movement of curcumin prodrugs into clinical trials.

  19. New prodrugs of two pyrimidine acyclic nucleoside phosphonates: Synthesis and antiviral activity.

    PubMed

    Krečmerová, Marcela; Dračínský, Martin; Snoeck, Robert; Balzarini, Jan; Pomeisl, Karel; Andrei, Graciela

    2017-09-01

    New 2,4-diamino-6-[2-(phosphonomethoxy)ethoxy]pyrimidine (PMEO-DAPy) and 1-[2-(phosphonomethoxy)ethyl]-5-azacytosine (PME-5-azaC) prodrugs were prepared with a pro-moiety consisting of carbonyloxymethyl esters (POM, POC), alkoxyalkyl esters, amino acid phosphoramidates and/or tyrosine. The activity of the prodrugs was evaluated in vitro against different virus families. None of the synthesized prodrugs demonstrated activity against RNA viruses but some of them proved active against herpesviruses [including herpes simplex virus (HSV), varicella-zoster virus (VZV), and human cytomegalovirus (HCMV)]. The bis(POC) and the bis(amino acid) phosphoramidate prodrugs of PMEO-DAPy inhibited herpesvirus replication at lower doses than the parent compound although the selectivity against HSV and VZV was only slightly improved compared to PMEO-DAPy. The mono-octadecyl ester of PME-5-azaC emerged as the most potent and selective PME-5-azaC prodrug against HSV, VZV and HCMV with EC 50 's of 0.15-1.12µM while PME-5-azaC only had marginal anti-herpesvirus activity. Although the bis(hexadecylamido-l-tyrosyl) and the bis(POM) esters of PME-5-azaC were also very potent anti-herpesvirus drugs, these were less selective than the mono-octadecyl ester prodrug. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Metronidazole prodrugs: synthesis, physicochemical properties, stability, and ex vivo release studies.

    PubMed

    Mura, Carla; Valenti, Donatella; Floris, Costantino; Sanna, Roberta; De Luca, Maria Antonietta; Fadda, Anna Maria; Loy, Giuseppe

    2011-09-01

    The aim of the present study was to develop a colon targeted delivery system for metronidazole using polymeric prodrug formulation. Two chitosan amide conjugates of metronidazole were prepared by using two different spacers to covalently link the drug to the amino group of the chitosan glucosamine units. Glutaric and succinic hemiesters of metronidazole were thus prepared and then coupled to chitosan to obtain metronidazole-glutaryl- and metronidazole-succinyl-chitosan conjugates. Polymeric prodrugs were characterized by solid state NMR method, namely carbon 13 cross polarization magic angle spinning ((13)C NMR CPMAS). Prodrug stability study was carried out in acid (pH = 1.2) and in alkaline (pH = 7.4) buffers in a thermostatic bath at 37 °C. Drug release from the two prodrugs was studied by incubating each of them with 10% w/v cecal and colonic content of rats. Obtained results showed that both prodrugs were adequately stable in acid environment, while the succinyl conjugate was more stable than the glutaryl one in alkaline buffer. Both the prodrugs released the drug in cecal and colonic content, showing that the two systems could serve as colon specific delivery systems of metronidazole. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  1. Dual-targeted and pH-sensitive Doxorubicin Prodrug-Microbubble Complex with Ultrasound for Tumor Treatment

    PubMed Central

    Luo, Wanxian; Wen, Ge; Yang, Li; Tang, Jiao; Wang, Jianguo; Wang, Jihui; Zhang, Shiyu; Zhang, Li; Ma, Fei; Xiao, Liling; Wang, Ying; Li, Yingjia

    2017-01-01

    In this study, we investigated the potential of a dual-targeted pH-sensitive doxorubicin prodrug-microbubble complex (DPMC) in ultrasound (US)-assisted antitumor therapy. The doxorubicin prodrug (DP) consists of a succinylated-heparin carrier conjugated with doxorubicin (DOX) via hydrazone linkage and decorated with dual targeting ligands, folate and cRGD peptide. Combination of microbubble (MB) and DP, generated via avidin-biotin binding, promoted intracellular accumulation and improved therapeutic efficiency assisted by US cavitation and sonoporation. Aggregates of prepared DP were observed with an inhomogeneous size distribution (average diameters: 149.6±29.8 nm and 1036.2±38.8 nm, PDI: 1.0) while DPMC exhibited a uniform distribution (average diameter: 5.804±2.1 μm), facilitating its usage for drug delivery. Notably, upon US exposure, DPMC was disrupted and aggregated DP dispersed into homogeneous small-sized nanoparticles (average diameter: 128.6±42.3 nm, PDI: 0.21). DPMC could target to angiogenic endothelial cells in tumor region via αvβ3-mediated recognition and subsequently facilitate its specific binding to tumor cells mediated via recognition of folate receptor (FR) after US exposure. In vitro experiments showed higher tumor specificity and killing ability of DPMC with US than free DOX and DP for breast cancer MCF-7 cells. Furthermore, significant accumulation and specificity for tumor tissues of DPMC with US were detected using in vivo fluorescence and ultrasound molecular imaging, indicating its potential to integrate tumor imaging and therapy. In particular, through inducing apoptosis, inhibiting cell proliferation and antagonizing angiogenesis, DPMC with US produced higher tumor inhibition rates than DOX or DPMC without US in MCF-7 xenograft tumor-bearing mice while inducing no obvious body weight loss. Our strategy provides an effective platform for the delivery of large-sized or aggregated particles to tumor sites, thereby extending their

  2. Macrocyclic Prodrugs of a Selective Nonpeptidic Direct Thrombin Inhibitor Display High Permeability, Efficient Bioconversion but Low Bioavailability.

    PubMed

    Andersson, Vincent; Bergström, Fredrik; Brånalt, Jonas; Grönberg, Gunnar; Gustafsson, David; Karlsson, Staffan; Polla, Magnus; Bergman, Joakim; Kihlberg, Jan

    2016-07-28

    The only oral direct thrombin inhibitors that have reached the market, ximelagatran and dabigatran etexilat, are double prodrugs with low bioavailability in humans. We have evaluated an alternative strategy: the preparation of a nonpeptidic, polar direct thrombin inhibitor as a single, macrocyclic esterase-cleavable (acyloxy)alkoxy prodrug. Two homologous prodrugs were synthesized and displayed high solubilities and Caco-2 cell permeabilities, suggesting high absorption from the intestine. In addition, they were rapidly and completely converted to the active zwitterionic thrombin inhibitor in human hepatocytes. Unexpectedly, the most promising prodrug displayed only moderately higher oral bioavailability in rat than the polar direct thrombin inhibitor, most likely due to rapid metabolism in the intestine or the intestinal wall. To the best of our knowledge, this is the first in vivo ADME study of macrocyclic (acyloxy)alkoxy prodrugs, and it remains to be established if the modest increase in bioavailability is a general feature of this category of prodrugs or not.

  3. Genetic polymorphisms in phase I and phase II enzymes and breast cancer risk associated with menopausal hormone therapy in postmenopausal women.

    PubMed

    2010-01-01

    Recent findings indicate a greater risk of postmenopausal breast cancer with estrogen-progestagen therapy than estrogen monotherapy, and more so for current than past use. Few studies have examined individual genetic susceptibility to the effects of menopausal hormone therapy. We used two population-based case-control studies with 3,155 postmenopausal breast cancer patients and 5,496 controls to evaluate modification of breast cancer risk associated with duration of hormone use by genes involved in hormone metabolism and detoxification. Twenty-eight polymorphisms in eight genes of phase I (CYP1A1, CYP1A2, CYP1B1, CYP2C9, CYP2C19, CYP3A4, CYP3A5, CYP3A7) and nine genes of phase II enzymes (COMT, GSTM1, GSTM3, GSTP1, GSTT1, SULT1A1, UGT1A1, UGT1A6, UGT2B7) were genotyped. The risk associated with duration of use of combined estrogen-progestagen therapy was significantly modified by genetic polymorphisms located in CYP1B1, GSTP1, and GSTT1. In homozygote carriers of the CYP1B1_142_G and the CYP1B1_355 _T variant alleles, adjusted odds ratios (OR) per year of use were 1.06 (95% confidence interval (CI) = 1.02-1.09) and 1.06 (95% CI = 1.03-1.09), respectively, compared with 1.02 (95% CI = 1.01-1.03) in non-carriers of either polymorphism (p(interaction) = 0.01). Carriers of the functional GSTT1 allele and the GSTP1_341_T allele were at significantly higher risks associated with hormone use compared with non-carriers (p(interaction) = 0.0001 and 0.02). CYP1A1_2452_C>A significantly reduced the risk associated with duration of use of estrogen monotherapy (p(interaction) = 0.01). The finding regarding GSTT1 was still statistically significant after corrections for multiple comparisons. Postmenopausal breast cancer risk associated with hormone therapy may be modified by genetically determined variations in phase I and II enzymes involved in steroid hormone metabolism.

  4. Safety and efficacy of enzyme replacement therapy with agalsidase beta: an international, open-label study in pediatric patients with Fabry disease.

    PubMed

    Wraith, J Edmond; Tylki-Szymanska, Anna; Guffon, Nathalie; Lien, Y Howard; Tsimaratos, Michel; Vellodi, Ashok; Germain, Dominique P

    2008-04-01

    To evaluate the safety and explore the efficacy of enzyme replacement therapy with agalsidase beta (recombinant human alpha-galactosidase A; Fabrazyme [Genzyme Corporation, Cambridge, MA]) in pediatric patients with Fabry disease, a genetic disorder in which deficient endogenous enzyme causes pathogenic tissue accumulation of globotriaosylceramide (GL-3). Fourteen male and 2 female patients, 8 to 16 years old, were treated in this open-label study. A 12-week observation period to collect baseline data preceded the 48-week treatment period when agalsidase beta (1 mg/kg) was infused intravenously every 2 weeks. No primary efficacy end point was specified. Before treatment, results of skin biopsies from 12 male patients showed moderate or severe GL-3 accumulation in superficial dermal capillary endothelial cells; with treatment, these cells were completely cleared of GL-3 in week-24 biopsies from all 12 male patients and in all available week-48 biopsies. With treatment, reports of gastrointestinal symptoms declined steadily. Patient diaries documented significant reductions in school absences due to sickness. Agalsidase beta was generally well tolerated; most treatment-related adverse events were mild or moderate infusion-associated reactions involving rigors, fever, or rhinitis. Agalsidase beta safely and effectively reduced the GL-3 accumulation in dermal endothelium already evident in children with Fabry disease. Early intervention may prevent irreversible end-organ damage from chronic GL-3 deposition.

  5. The effect of enzyme replacement therapy on clinical outcomes in paediatric patients with Fabry disease - A systematic literature review by a European panel of experts.

    PubMed

    Spada, Marco; Baron, Ralf; Elliott, Perry M; Falissard, Bruno; Hilz, Max J; Monserrat, Lorenzo; Tøndel, Camilla; Tylki-Szymańska, Anna; Wanner, Christoph; Germain, Dominique P

    2018-04-26

    Fabry disease is caused by a deficiency of the lysosomal enzyme α-galactosidase, resulting in progressive accumulation of globotriaosylceramide (GL-3). The disease can manifest early during childhood and adolescence. Enzyme replacement therapy (ERT) with recombinant human α-galactosidase is the first specific treatment for Fabry disease and has been available in Europe since 2001. This paper presents the findings of a systematic literature review of clinical outcomes with ERT in paediatric patients with Fabry disease. A comprehensive systematic review of published literature on ERT in Fabry disease was conducted in January 2017. The literature analysis included all original articles reporting outcomes of ERT in paediatric patients. Treatment-related outcomes in the paediatric population were reported in six publications derived from open-label clinical trials and in 10 publications derived from observational or registry-based studies. ERT was shown to significantly reduce plasma and urine GL-3 levels in paediatric patients with Fabry disease. The effect of ERT on GL-3 clearance from renal podocytes appeared to be agalsidase dose-dependent. ERT relieved pain and improved gastrointestinal symptoms and quality of life. Based on the published literature, the use of ERT in paediatric patients can significantly clear GL-3 accumulation, ameliorate the early symptoms of Fabry disease, and improve quality of life. Treatment with ERT in paediatric patients with Fabry disease may be important to prevent further disease progression and overt organ damage. Copyright © 2018. Published by Elsevier Inc.

  6. Pharmacokinetics and Abuse Potential of Benzhydrocodone, a Novel Prodrug of Hydrocodone, After Intranasal Administration in Recreational Drug Users.

    PubMed

    Mickle, Travis C; Guenther, Sven M; Barrett, Andrew C; Roupe, Kathryn Ann; Zhou, Jing; Dickerson, Daniel; Webster, Lynn R

    2017-10-28

    Developing an acetaminophen-free, immediate-release hydrocodone product remains an unmet medical need; however, new opioid analgesics should not introduce new abuse risks. Benzhydrocodone is a prodrug of hydrocodone that must be metabolized into hydrocodone by enzymes in the intestinal tract to optimally deliver its pharmacologic effects. This study evaluated the intranasal pharmacokinetics and abuse potential of benzhydrocodone active pharmaceutical ingredient (API) compared with hydrocodone bitartrate (HB) API. Single-center, randomized, double-blind, crossover study. Clinical research site. Healthy adult, nondependent, recreational opioid users. Subjects (N = 51 Completers) were randomized to receive 13.34 mg of intranasal benzhydrocodone API and 15.0 mg of intranasal HB API (molar-equivalent doses of hydrocodone). Blood samples were taken, and Drug Liking scores (assessed on a bipolar visual analog scale) were obtained throughout each dosing interval. Nasal irritation and safety were assessed. Peak hydrocodone plasma concentration (Cmax) was 36.0% lower, and total hydrocodone exposures (AUClast and AUCinf) were 20.3% and 19.5% lower, respectively, for benzhydrocodone API compared with HB API (P < 0.0001). All partial AUC values were lower for benzhydrocodone API, with a ≥ 75% reduction in hydrocodone exposure at all time intervals up to one hour postdose (P < 0.0001). Median Tmax of hydrocodone following benzhydrocodone API was delayed by more than one hour compared with HB. Drug Liking score, as assessed by maximal liking (Emax), was significantly lower for benzhydrocodone API vs HB API (P = 0.004), with 45% of subjects showing a ≥ 30% reduction in Drug Liking Emax. Reductions in hydrocodone exposure and associated decreases in Drug Liking relative to HB suggest that the prodrug benzhydrocodone may deter intranasal abuse. © 2017 American Academy of Pain Medicine.

  7. Human transport protein carrier for controlled photoactivation of antitumor prodrug and real-time intracellular tumor imaging.

    PubMed

    Li, Xi; Mu, Jing; Liu, Fang; Tan, Eddy Wei Ping; Khezri, Bahareh; Webster, Richard D; Yeow, Edwin Kok Lee; Xing, Bengang

    2015-05-20

    Current anticancer chemotherapy often suffers from poor tumor selectivity and serious drug resistance. Proper vectors for targeted delivery and controlled drug release play crucial roles in improving the therapeutic selectivity to tumor areas and also overcoming the resistance of cancer cells. In this work, we developed a novel human serum albumin (HSA) protein-based nanocarrier system, which combines the photoactivatable Pt(IV) antitumor prodrug for realizing the controlled release and fluorescent light-up probe for evaluations of drug action and efficacy. The constructed Pt(IV)-probe@HSA platform can be locally activated by light irradiation to release the active Pt species, which results in enhanced cell death at both drug-sensitive A2780 and cisplatin-resistant A2780cis cell lines when compared to the free prodrug molecules. Simultaneously, the cytotoxicity caused by light controlled drug release would further lead to the cellular apoptosis and trigger the activation of caspases 3, one crucial protease enzyme in apoptotic process, which could cleave the recognition peptide moiety (DEVD) with a flanking fluorescent resonance energy transfer (FRET) pair containing near-infrared (NIR) fluorophore Cy5 and quencher Qsy21 on the HSA nanocarrier surface. The turn-on fluorescence in response to caspase-3 could be assessed by fluorescence microscopy and flow cytometry analysis. Our results supported the hypothesis that such a unique design may present a successful platform for multiple roles: (i) a biocompatible protein-based nanocarrier for drug delivery, (ii) the controlled drug release with strengthened therapeutic effects, (iii) real-time monitoring of antitumor drug efficacy at the earlier stage.

  8. Development and characterization of PLGA nanoparticles as delivery systems of a prodrug of zidovudine obtained by its conjugation with ursodeoxycholic acid.

    PubMed

    Dalpiaz, Alessandro; Contado, Catia; Mari, Lara; Perrone, Daniela; Pavan, Barbara; Paganetto, Guglielmo; Hanuskovà, Miriam; Vighi, Eleonora; Leo, Eliana

    2014-05-01

    Zidovudine (AZT) is employed against AIDS and hepatitis; its use is limited by active efflux transporters (AETs) that induce multidrug resistance for intracellular therapies and hamper AZT to reach the brain. Ursodeoxycholic acid (UDCA) conjugation with AZT (prodrug UDCA-AZT) allows to elude the AET systems. To investigate the effect of the Pluronic F68 coating on the loading, release and stability of poly(D,L lactide-co-glicolide) nanoparticles (NPs) embedded with UDCA-AZT. The mean diameter of the NP prepared by nanoprecipitation or emulsion/solvent evaporation methods was determined using both photon correlation spectroscopy and sedimentation field-flow fractionation; particle morphology was detected by scanning electron microscope. The stability of the free and encapsulated UDCA-AZT was evaluated in rat liver homogenates by high-performance liquid chromatography analysis. The mean diameter of the NPs was found to be ∼ 600 nm with a relatively high polydispersity. The NPs obtained by emulsion/solvent evaporation were not able to control the prodrug release, differently from NPs obtained by nanoprecipitation. The presence of the Pluronic coating did not substantially modify the kinetics of the drug release, or the extent of the burst effect that were instead only influenced by the preparation parameters. UDCA-AZT incorporated in the NPs was more stable in the rat liver homogenates than the free prodrug and no influence of the Pluronic coating was observed. Considering the different potential applications of nanoparticles coated and uncoated with Pluronic (brain and macrophage targeting, respectively), both of these nanoparticle systems could be useful in the therapies against HIV.

  9. Fluorogenic reaction-based prodrug conjugates as targeted cancer theranostics.

    PubMed

    Lee, Min Hee; Sharma, Amit; Chang, Min Jung; Lee, Jinju; Son, Subin; Sessler, Jonathan L; Kang, Chulhun; Kim, Jong Seung

    2018-01-02

    Theranostic systems are receiving ever-increasing attention due to their potential therapeutic utility, imaging enhancement capability, and promise for advancing the field of personalized medicine, particularly as it relates to the diagnosis, staging, and treatment of cancer. In this Tutorial Review, we provide an introduction to the concepts of theranostic drug delivery effected via use of conjugates that are able to target cancer cells selectively, provide cytotoxic chemotherapeutics, and produce readily monitored imaging signals in vitro and in vivo. The underlying design concepts, requiring the synthesis of conjugates composed of imaging reporters, masked chemotherapeutic drugs, cleavable linkers, and cancer targeting ligands, are discussed. Particular emphasis is placed on highlighting the potential benefits of fluorogenic reaction-based targeted systems that are activated for both imaging and therapy by cellular entities, e.g., thiols, reactive oxygen species and enzymes, which are present at relatively elevated levels in tumour environments, physiological characteristics of cancer, e.g., hypoxia and acidic pH. Also discussed are systems activated by an external stimulus, such as light. The work summarized in this Tutorial Review will help define the role fluorogenic reaction-based, cancer-targeting theranostics may have in advancing drug discovery efforts, as well as improving our understanding of cellular uptake and drug release mechanisms.

  10. Engineered mesenchymal stem cells as vectors in a suicide gene therapy against preclinical murine models for solid tumors.

    PubMed

    Amara, Ikrame; Pramil, Elodie; Senamaud-Beaufort, Catherine; Devillers, Audrey; Macedo, Rodney; Lescaille, Géraldine; Seguin, Johanne; Tartour, Eric; Lemoine, François M; Beaune, Philippe; de Waziers, Isabelle

    2016-10-10

    Gene-directed enzyme pro-drug therapy (GDEPT) consists of expressing, in tumor cells, a suicide gene which converts a pro-drug into cytotoxic metabolites, in situ. In a previous work, we demonstrated that the combination of the suicide gene CYP2B6TM-RED (a fusion of a triple mutant of CYP2B6 with NADPH cytochrome P450 reductase) and cyclophosphamide (CPA) constituted a powerful treatment for solid tumors. In this work, we investigated the use of mesenchymal stem cells (MSCs) as cellular vehicles for the delivery of our suicide gene. MSCs were genetically engineered ex-vivo to stably express CYP2B6TM-RED. Ex vivo and in vivo investigations showed that MSCs expressing CYP2B6TM-RED were able 1) to bioactivate CPA and produce local cytotoxic metabolites in tumor sites and 2) to destroy neighboring tumor cells through a bystander effect. Intratumoral injections of CYP2B6TM-RED-MSCs and CPA completely eradicated tumors in 33% of mice without recurrence after 6months. Rechallenge experiments demonstrated an efficient immune response. These data suggest that MSCs expressing CYP2B6TM-RED with CPA could represent a promising treatment for solid tumors to test in future clinical trials. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Intra-articular Enzyme Replacement Therapy with rhIDUA is Safe, Well-Tolerated, and Reduces Articular GAG Storage in the Canine Model of Mucopolysaccharidosis Type I

    PubMed Central

    Wang, Raymond Y; Aminian, Afshin; McEntee, Michael F; Kan, Shih-Hsin; Simonaro, Calogera M; Lamanna, William; Lawrence, Roger; Ellinwood, N. Matthew; Guerra, Catalina; Le, Steven Q; Dickson, Patricia I; Esko, Jeffrey D

    2014-01-01

    Background Treatment with intravenous enzyme replacement therapy and hematopoietic stem cell transplantation for mucopolysaccharidosis (MPS) type I does not address joint disease, resulting in persistent orthopedic complications and impaired quality of life. A proof-of-concept study was conducted to determine the safety, tolerability, and efficacy of intra-articular recombinant human iduronidase (IA-rhIDUA) enzyme replacement therapy in the canine MPS I model. Methods Four MPS I dogs underwent monthly rhIDUA injections (0.58 mg/joint) into the right elbow and knee for six months. Contralateral elbows and knees concurrently received normal saline. No intravenous rhIDUA therapy was administered. Monthly blood counts, chemistries, anti-rhIDUA antibody titers, and synovial fluid cell counts were measured. Lysosomal storage of synoviocytes and chondrocytes, synovial macrophages and plasma cells were scored at baseline and one month following the final injection. Results All injections were well-tolerated without adverse reactions. One animal required prednisone for spinal cord compression. There were no clinically significant abnormalities in blood counts or chemistries. Circulating anti-rhIDUA antibody titers gradually increased in all dogs except the prednisone-treated dog; plasma cells, which were absent in all baseline synovial specimens, were predominantly found in synovium of rhIDUA-treated joints at study-end. Lysosomal storage in synoviocytes and chondrocytes following 6 months of IA-rhIDUA demonstrated significant reduction compared to tissues at baseline, and saline-treated tissues at study-end. Mean joint synovial GAG levels in IA-rhIDUA joints was 8.62±5.86 μg/mg dry weight and 21.6±10.4 μg/mg dry weight in control joints (60% reduction). Cartilage heparan sulfate was also reduced in the IA-rhIDUA joints (113±39.5 ng/g wet weight) compared to saline-treated joints (142±56.4 ng/g wet weight). Synovial macrophage infiltration, which was present in all

  12. Intra-articular enzyme replacement therapy with rhIDUA is safe, well-tolerated, and reduces articular GAG storage in the canine model of mucopolysaccharidosis type I.

    PubMed

    Wang, Raymond Y; Aminian, Afshin; McEntee, Michael F; Kan, Shih-Hsin; Simonaro, Calogera M; Lamanna, William C; Lawrence, Roger; Ellinwood, N Matthew; Guerra, Catalina; Le, Steven Q; Dickson, Patricia I; Esko, Jeffrey D

    2014-08-01

    Treatment with intravenous enzyme replacement therapy and hematopoietic stem cell transplantation for mucopolysaccharidosis (MPS) type I does not address joint disease, resulting in persistent orthopedic complications and impaired quality of life. A proof-of-concept study was conducted to determine the safety, tolerability, and efficacy of intra-articular recombinant human iduronidase (IA-rhIDUA) enzyme replacement therapy in the canine MPS I model. Four MPS I dogs underwent monthly rhIDUA injections (0.58 mg/joint) into the right elbow and knee for 6 months. Contralateral elbows and knees concurrently received normal saline. No intravenous rhIDUA therapy was administered. Monthly blood counts, chemistries, anti-rhIDUA antibody titers, and synovial fluid cell counts were measured. Lysosomal storage of synoviocytes and chondrocytes, synovial macrophages and plasma cells were scored at baseline and 1 month following the final injection. All injections were well-tolerated without adverse reactions. One animal required prednisone for spinal cord compression. There were no clinically significant abnormalities in blood counts or chemistries. Circulating anti-rhIDUA antibody titers gradually increased in all dogs except the prednisone-treated dog; plasma cells, which were absent in all baseline synovial specimens, were predominantly found in synovium of rhIDUA-treated joints at study-end. Lysosomal storage in synoviocytes and chondrocytes following 6 months of IA-rhIDUA demonstrated significant reduction compared to tissues at baseline, and saline-treated tissues at study-end. Mean joint synovial GAG levels in IA-rhIDUA joints were 8.62 ± 5.86 μg/mg dry weight and 21.6 ± 10.4 μg/mg dry weight in control joints (60% reduction). Cartilage heparan sulfate was also reduced in the IA-rhIDUA joints (113 ± 39.5 ng/g wet weight) compared to saline-treated joints (142 ± 56.4 ng/g wet weight). Synovial macrophage infiltration, which was present in all joints at baseline, was

  13. Gene therapy in liver diseases: state-of-the-art and future perspectives.

    PubMed

    Domvri, Kalliopi; Zarogoulidis, Paul; Porpodis, Konstantinos; Koffa, Maria; Lambropoulou, Maria; Kakolyris, Stylianos; Kolios, George; Zarogoulidis, Konstantinos; Chatzaki, Ekaterini

    2012-12-01

    Gene therapy is a fundamentally novel therapeutic approach that involves introducing genetic material into target cells in order to fight or prevent disease. A number of different strategies of gene therapy are tested at experimental and clinical levels, including: a) replacing a mutated gene that causes disease with a healthy copy of the gene, b) inactivating a mutated gene that its improper function causes pathogenesis, c) introducing a new gene coding a therapeutic compound to fight a disease, d) introducing to the target organ an enzyme converting an inactive pro-drug to its cytotoxic metabolite. In gene therapy, the transcriptional machinery of the patient is used to produce the active factor that exerts the intended therapeutic effect, ideally in a permanent, tissue-specific and manageable way. The liver is a major target for gene therapy, presenting inherited metabolic defects of single-gene etiology, but also severe multifactorial pathologies with limited therapeutic options such as hepatocellular carcinoma. The initial promising results from gene therapy strategies in liver diseases were followed by skepticism on the actual clinical value due to specificity, efficacy, toxicity and immune limitations, but are recently re-evaluated due to progress in vector technology and monitoring techniques. The significant amount of experimental data along with the available information from clinical trials are systematically reviewed here and presented per pathological entity. Finally, future perspectives of gene therapy protocols in hepatology are summarized.

  14. Polyphosphoester-Camptothecin Prodrug with Reduction-Response Prepared via Michael Addition Polymerization and Click Reaction.

    PubMed

    Du, Xueqiong; Sun, Yue; Zhang, Mingzu; He, Jinlin; Ni, Peihong

    2017-04-26

    Polyphosphoesters (PPEs), as potential candidates for biocompatible and biodegradable polymers, play an important role in material science. Various synthetic methods have been employed in the preparation of PPEs such as polycondensation, polyaddition, ring-opening polymerization, and olefin metathesis polymerization. In this study, a series of linear PPEs has been prepared via one-step Michael addition polymerization. Subsequently, camptothecin (CPT) derivatives containing disulfide bonds and azido groups were linked onto the side chain of the PPE through Cu(I)-catalyzed azidealkyne cyclo-addition "click" chemistry to yield a reduction-responsive polymeric prodrug P(EAEP-PPA)-g-ss-CPT. The chemical structures were characterized by nuclear magnetic resonance spectroscopy, gel permeation chromatography, Fourier transform infrared, ultraviolet-visible spectrophotometer, and high performance liquid chromatograph analyses, respectively. The amphiphilic prodrug could self-assemble into micelles in aqueous solution. The average particle size and morphology of the prodrug micelles were measured by dynamic light scattering and transmission electron microscopy, respectively. The results of size change under different conditions indicate that the micelles possess a favorable stability in physiological conditions and can be degraded in reductive medium. Moreover, the studies of in vitro drug release behavior confirm the reduction-responsive degradation of the prodrug micelles. A methyl thiazolyl tetrazolium assay verifies the good biocompatibility of P(EAEP-PPA) not only for normal cells, but also for tumor cells. The results of cytotoxicity and the intracellular uptake about prodrug micelles further demonstrate that the prodrug micelles can efficiently release CPT into 4T1 or HepG2 cells to inhibit the cell proliferation. All these results show that the polyphosphoester-based prodrug can be used for triggered drug delivery system in cancer treatment.

  15. Decreased Risk of Radiation Pneumonitis With Incidental Concurrent Use of Angiotensin-Converting Enzyme Inhibitors and Thoracic Radiation Therapy

    SciTech Connect

    Kharofa, Jordan; Cohen, Eric P.; Tomic, Rade

    2012-09-01

    Purpose: Angiotensin-converting enzyme (ACE) inhibitors have been shown to mitigate radiation-induced lung injury in preclinical models. The aim of this study was to evaluate whether ACE inhibitors decrease the risk of radiation pneumonitis in lung cancer patients receiving thoracic irradiation. Methods and Materials: Patients with Stage I through III small-cell and non-small-cell lung cancer treated definitively with radiation from 2004-2009 at the Clement J. Zablocki Veterans Affairs Medical Center were retrospectively reviewed. Acute pulmonary toxicity was quantified within 6 months of completion of treatment according to the Common Terminology Criteria for Adverse Events version 4. The use of ACE inhibitors,more » nonsteroidal anti-inflammatory drugs, inhaled glucocorticosteroids, statins, and angiotensin receptor blockers; dose-volume histogram parameters; and patient factors were assessed for association with Grade 2 or higher pneumonitis. Results: A total of 162 patients met the criteria for inclusion. The majority of patients had Stage III disease (64%) and received concurrent chemotherapy (61%). Sixty-two patients were identified as ACE inhibitor users (38%). All patients had acceptable radiation plans based on dose-volume histogram constraints (V20 [volume of lung receiving at least 20 Gy] {<=}37% and mean lung dose {<=}20 Gy) with the exception of 2 patients who did not meet both criteria. Grade 2 or higher pulmonary toxicity occurred in 12 patients (7.4%). The rate of Grade 2 or higher pneumonitis was lower in ACE inhibitor users vs. nonusers (2% vs. 11%, p = 0.032). Rates of Grade 2 or higher pneumonitis were significantly increased in patients aged greater than 70 years (16% vs. 2%, p = 0.005) or in whom V5 (volume of lung receiving at least 5 Gy) was 50% or greater (13% vs. 4%, p = 0.04). V10 (volume of lung receiving at least 10 Gy), V20, V30 (volume of lung receiving at least 30 Gy), and mean lung dose were not independently associated with Grade

  16. Flurbiprofen–antioxidant mutual prodrugs as safer nonsteroidal anti-inflammatory drugs: synthesis, pharmacological investigation, and computational molecular modeling

    PubMed Central

    Ashraf, Zaman; Alamgeer; Kanwal, Munazza; Hassan, Mubashir; Abdullah, Sahar; Waheed, Mamuna; Ahsan, Haseeb; Kim, Song Ja

    2016-01-01

    Flurbiprofen–antioxidant mutual prodrugs were synthesized to reduce the gastrointestinal (GI) effects associated with flurbiprofen. For reducing the GI toxicity, the free carboxylic group (–COOH) was temporarily masked by esterification with phenolic –OH of natural antioxidants vanillin, thymol, umbelliferone, and sesamol. The in vitro hydrolysis of synthesized prodrugs showed that they were stable in buffer solution at pH 1.2, indicating their stability in the stomach. The synthesized prodrugs undergo significant hydrolysis in 80% human plasma and thus release free flurbiprofen. The minimum reversion was observed at pH 1.2, suggesting that prodrugs are less irritating to the stomach than flurbiprofen. The anti-inflammatory, analgesic, antipyretic, and ulcerogenic activities of prodrugs were evaluated. All the synthesized prodrugs significantly (P<0.001) reduced the inflammation against carrageenan and egg albumin-induced paw edema at 4 hours of study. The reduction in the size of the inflamed paw showed that most of the compounds inhibited the later phase of inflammation. The prodrug 2-oxo-2H-chromen-7-yl-2-(2-fluorobiphenyl-4-yl)propanoate (4b) showed significant reduction in paw licking with percentage inhibition of 58%. It also exhibited higher analgesic activity, reducing the number of writhes with a percentage of 75%, whereas flurbiprofen showed 69% inhibition. Antipyretic activity was investigated using brewer’s yeast-induced pyrexia model, and significant (P<0.001) reduction in rectal temperature was shown by all prodrugs at all times of assessment. The results of ulcerogenic activity showed that all prodrugs produced less GI irritation than flurbiprofen. Molecular docking and simulation studies were carried out with cyclooxygenase (COX-1 and COX-2) proteins, and it was observed that our prodrugs have more potential to selectively bind to COX-2 than to COX-1. It is concluded that the synthesized prodrugs have promising pharmacological activities

  17. Flurbiprofen-antioxidant mutual prodrugs as safer nonsteroidal anti-inflammatory drugs: synthesis, pharmacological investigation, and computational molecular modeling.

    PubMed

    Ashraf, Zaman; Alamgeer; Kanwal, Munazza; Hassan, Mubashir; Abdullah, Sahar; Waheed, Mamuna; Ahsan, Haseeb; Kim, Song Ja

    2016-01-01

    Flurbiprofen-antioxidant mutual prodrugs were synthesized to reduce the gastrointestinal (GI) effects associated with flurbiprofen. For reducing the GI toxicity, the free carboxylic group (-COOH) was temporarily masked by esterification with phenolic -OH of natural antioxidants vanillin, thymol, umbelliferone, and sesamol. The in vitro hydrolysis of synthesized prodrugs showed that they were stable in buffer solution at pH 1.2, indicating their stability in the stomach. The synthesized prodrugs undergo significant hydrolysis in 80% human plasma and thus release free flurbiprofen. The minimum reversion was observed at pH 1.2, suggesting that prodrugs are less irritating to the stomach than flurbiprofen. The anti-inflammatory, analgesic, antipyretic, and ulcerogenic activities of prodrugs were evaluated. All the synthesized prodrugs significantly (P<0.001) reduced the inflammation against carrageenan and egg albumin-induced paw edema at 4 hours of study. The reduction in the size of the inflamed paw showed that most of the compounds inhibited the later phase of inflammation. The prodrug 2-oxo-2H-chromen-7-yl-2-(2-fluorobiphenyl-4-yl)propanoate (4b) showed significant reduction in paw licking with percentage inhibition of 58%. It also exhibited higher analgesic activity, reducing the number of writhes with a percentage of 75%, whereas flurbiprofen showed 69% inhibition. Antipyretic activity was investigated using brewer's yeast-induced pyrexia model, and significant (P<0.001) reduction in rectal temperature was shown by all prodrugs at all times of assessment. The results of ulcerogenic activity showed that all prodrugs produced less GI irritation than flurbiprofen. Molecular docking and simulation studies were carried out with cyclooxygenase (COX-1 and COX-2) proteins, and it was observed that our prodrugs have more potential to selectively bind to COX-2 than to COX-1. It is concluded that the synthesized prodrugs have promising pharmacological activities with

  18. Hydrolyzable Poly[Poly(Ethylene Glycol) Methyl Ether Acrylate]-Colistin Prodrugs through Copper-Mediated Photoinduced Living Radical Polymerization.

    PubMed

    Zhu, Chongyu; Schneider, Elena K; Nikolaou, Vasiliki; Klein, Tobias; Li, Jian; Davis, Thomas P; Whittaker, Michael R; Wilson, Paul; Kempe, Kristian; Velkov, Tony; Haddleton, David M

    2017-07-19

    Through the recently developed copper-mediated photoinduced living radical polymerization (CP-LRP), a novel and well-defined polymeric prodrug of the antimicrobial lipopeptide colistin has been developed. A colistin initiator (Boc 5 -col-Br 2 ) was synthesized through the modification of colistin on both of its threonine residues using a cleavable initiator linker, 2-(2-bromo-2-methylpropanoyloxy) acetic acid (BMPAA), and used for the polymerization of acrylates via CP-LRP. Polymerization proceeds from both sites of the colistin initiator, and through the polymerization of poly(ethylene glycol) methyl ether acrylate (PEGA 480 ), three water-soluble polymer-colistin conjugates (col-PPEGA, having degrees of polymerization of 5, 10, and 20) were achieved with high yield (conversion of ≥93%) and narrow dispersities (Đ < 1.3) in 2-4 h. Little or no effect on the structure and activity of the colistin was observed during the synthesis, and most of the active colistin can be recovered from the conjugates in vitro within 2 days. Furthermore, in vitro biological analyses including disk diffusion, broth microdilution, and time-kill studies suggested that all of the conjugates have the ability to inhibit the growth of multidrug-resistant (MDR) Gram-negative bacteria, of which col-PPEGA DP5 and DP10 showed similar or better antibacterial performance compared to the clinically relevant colistin prodrug CMS, indicating their potential as an alternative antimicrobial therapy. Moreover, considering the control over the polymerization, the CP-LRP technique has the potential to provide an alternative platform for the development of polymer bioconjugates.

  19. Enhanced Intratumoral Delivery of SN38 as a Tocopherol Oxyacetate Prodrug Using Nanoparticles in a Neuroblastoma Xenograft Model.

    PubMed

    Nguyen, Ferro; Alferiev, Ivan; Guan, Peng; Guerrero, David T; Kolla, Venkatadri; Moorthy, Ganesh S; Chorny, Michael; Brodeur, Garrett M

    2018-06-01

    Purpose: Currently, <50% of high-risk pediatric solid tumors like neuroblastoma can be cured, and many survivors experience serious or life-threatening toxicities, so more effective, less toxic therapy is needed. One approach is to target drugs to tumors using nanoparticles, which take advantage of the enhanced permeability of tumor vasculature. Experimental Design: SN38, the active metabolite of irinotecan (CPT-11), is a potent therapeutic agent that is readily encapsulated in polymeric nanoparticles. Tocopherol oxyacetate (TOA) is a hydrophobic mitocan that was linked to SN38 to significantly increase hydrophobicity and enhance nanoparticle retention. We treated neuroblastomas with SN38-TOA nanoparticles and compared the efficacy with the parent prodrug CPT-11 using a mouse xenograft model. Results: Nanoparticle treatment induced prolonged event-free survival (EFS) in most mice, compared with CPT-11. This was shown for both SH-SY5Y and IMR-32 neuroblastoma xenografts. Enhanced efficacy was likely due to increased and sustained drug levels of SN38 in the tumor compared with conventional CPT-11 delivery. Interestingly, when recurrent CPT-11-treated tumors were re-treated with SN38-TOA nanoparticles, the tumors transformed from undifferentiated neuroblastomas to maturing ganglioneuroblastomas. Furthermore, these tumors were infiltrated with Schwann cells of mouse origin, which may have contributed to the differentiated histology. Conclusions: Nanoparticle delivery of SN38-TOA produced increased drug delivery and prolonged EFS compared to conventional delivery of CPT-11. Also, lower total dose and drug entrapment in nanoparticles during circulation should decrease toxicity. We propose that nanoparticle-based delivery of a rationally designed prodrug is an attractive approach to enhance chemotherapeutic efficacy in pediatric and adult tumors. Clin Cancer Res; 24(11); 2585-93. ©2018 AACR . ©2018 American Association for Cancer Research.

  20. Biological and Mechanistic Characterization of Novel Prodrugs of Green Tea Polyphenol Epigallocatechin Gallate Analogs in Human Leiomyoma Cell Lines.

    PubMed

    Ahmed, Reda Saber Ibrahim; Liu, Gang; Renzetti, Andrea; Farshi, Pershang; Yang, Huanjie; Soave, Claire; Saed, Ghassan; El-Ghoneimy, Ashraf Ahmed; El-Banna, Hossny Awad; Foldes, Robert; Chan, Tak-Hang; Dou, Q Ping

    2016-10-01

    Uterine fibroids (leiomyomas) are very common benign tumors grown on the smooth muscle layer of the uterus, present in up to 75% of reproductive-age women and causing significant morbidity in a subset of this population. Although the etiology and biology of uterine fibroids are unclear, strong evidence supports that cell proliferation, angiogenesis and fibrosis are involved in their formation and growth. Currently the only cure for uterine fibroids is hysterectomy; the available alternative therapies have limitations. Thus, there is an urgent need for developing a novel strategy for treating this condition. The green tea polyphenol epigallocatechin gallate (EGCG) inhibits the growth of uterine leiomyoma cells in vitro and in vivo, and the use of a green tea extract (containing 45% EGCG) has demonstrated clinical activity without side effects in women with symptomatic uterine fibroids. However, EGCG has a number of shortcomings, including low stability, poor bioavailability, and high metabolic transformations under physiological conditions, presenting challenges for its development as a therapeutic agent. We developed a prodrug of EGCG (Pro-EGCG or 1) which shows increased stability, bioavailability and biological activity in vivo as compared to EGCG. We also synthesized prodrugs of EGCG analogs, compounds 2a and 4a, in order to potentially reduce their susceptibility to methylation/inhibition by catechol-O-methyltransferase. Here, we determined the effect of EGCG, Pro-EGCG, and 2a and 4a on cultured human uterine leiomyoma cells, and found that 2a and 4a have potent antiproliferative, antiangiogenic, and antifibrotic activities. J. Cell. Biochem. 117: 2357-2369, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. A comparative evaluation of treatments with 17β-estradiol and its brain-selective prodrug in a double-transgenic mouse model of Alzheimer's disease.

    PubMed

    Tschiffely, Anna E; Schuh, Rosemary A; Prokai-Tatrai, Katalin; Prokai, Laszlo; Ottinger, Mary Ann

    2016-07-01

    Estrogens are neuroprotective and, thus, potentially useful for the therapy of Alzheimer's disease; however, clinical use of hormone therapy remains controversial due to adverse peripheral effects. The goal of this study was to investigate the benefits of treatment with 10β,17β-dihydroxyestra-1,4-dien-3-one (DHED), a brain-selective prodrug of 17β-estradiol, in comparison with the parent hormone using APPswe/PS1dE9 double transgenic mice to model the pathology of the disease. Ovariectomized and intact females were continuously treated with vehicle, 17β-estradiol, or DHED via subcutaneous osmotic pumps from 6 to 8months of age. We confirmed that this prolonged treatment with DHED did not stimulate uterine tissue, whereas 17β-estradiol treatment increased uterine weight. Amyloid precursor protein decreased in both treatment groups of intact, but not in ovariectomized double transgenic females in which ovariectomy already decreased the expression of this protein significantly. However, reduced brain amyloid-β peptide levels could be observed for both treatments. Consequently, double-transgenic ovariectomized and intact mice had higher cognitive performance compared to untreated control animals in response to both estradiol and DHED administrations. Overall, the tested brain-selective 17β-estradiol prodrug proved to be an effective early-stage intervention in an Alzheimer's disease-relevant mouse model without showing systemic impact and, thus, warrants further evaluation as a potential therapeutic candidate. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Insulin dependence and pancreatic enzyme replacement therapy are independent prognostic factors for long-term survival after operation for chronic pancreatitis.

    PubMed

    Winny, Markus; Paroglou, Vagia; Bektas, Hüseyin; Kaltenborn, Alexander; Reichert, Benedikt; Zachau, Lea; Kleine, Moritz; Klempnauer, Jürgen; Schrem, Harald

    2014-02-01

    This retrospective, single-center, observational study on postoperative long-term results aims to define yet unknown factors for long-term outcome after operation for chronic pancreatitis. We analyzed 147 consecutive patients operated for chronic pancreatitis from 2000 to 2011. Mean follow-up was 5.3 years (range, 1 month to 12.7 years). Complete long-term survival data were provided by the German citizen registration authorities for all patients. A quality-of-life questionnaire was sent to surviving patients after a mean follow-up of 5.7 years. Surgical principles were resection (n = 86; 59%), decompression (n = 29; 20%), and hybrid procedures (n = 32; 21%). No significant influences of different surgical principles and operative procedures on survival, long-term quality of life and pain control could be detected. Overall 30-day mortality was 2.7%, 1-year survival 95.9%, and 3-year survival 90.8%. Multivariate Cox regression analysis revealed that only postoperative insulin dependence at the time of hospital discharge (P = .027; Exp(B) = 2.111; 95% confidence interval [CI], 1.089-4.090) and the absence of pancreas enzyme replacement therapy at the time of hospital discharge (P = .039; Exp(B) = 2.102; 95% CI, 1.037-4.262) were significant, independent risk factors for survival with significant hazard ratios for long-term survival. Long-term improvement in quality of life was reported by 55 of 76 long-term survivors (73%). Pancreatic enzyme replacement should be standard treatment after surgery for chronic pancreatitis at the time of hospital discharge, even when no clinical signs of exocrine pancreatic failure exist. This study underlines the potential importance of early operative intervention in chronic pancreatitis before irreversible endocrine dysfunction is present. Copyright © 2014 Mosby, Inc. All rights reserved.

  3. Drug-Induced Inhibition of Angiotensin Converting Enzyme and Dipeptidyl Peptidase 4 Results in Nearly Therapy Resistant Bradykinin Induced Angioedema: A Case Report

    PubMed Central

    Hahn, Janina; Trainotti, Susanne; Hoffmann, Thomas K.; Greve, Jens

    2017-01-01

    Patient: Female, 83 Final Diagnosis: Angioedema Symptoms: Edema Medication: Ramipril Clinical Procedure: — Specialty: Otolaryngology Objective: Unusual clinical course Background: Bradykinin is an underestimated mediator of angioedema. One subgroup of bradykinin induced angioedema is angioedema triggered by treatment with angiotensin converting enzyme (ACE) inhibitors. Due to its localization in the head and neck region and its unpredictable course, it is a possibly life-threatening condition. There is not an officially approved treatment for ACE inhibitor induced angioedema. Case Report: We present a case of an 83-year-old woman, who presented to our ENT department because of acute swelling of the tongue. On admission, there was no pharyngeal or laryngeal edema and no dyspnea. Treatment with glucocorticoids and antihistamines had no response. The patient had ramipril as regular medication, so we assumed ACE inhibitor induced angioedema and treated consequently with C1-inhibitor (human) 1,500 IU. Nevertheless, swelling was progressive and required intubation. Even after the second specific treatment with icatibant, her angioedema subsided extremely slowly. The patient also had regular treatment with saxagliptin, a dipeptidyl peptidase 4 inhibitor, so we assumed that the simultaneous inhibition of two bradykinin degrading enzymes led to a treatment-refractory course of angioedema. Conclusions: General awareness for bradykinin induced angioedema due to regular medication is limited. Our case demonstrated the importance of improving awareness and knowledge about this side effect. We need a better understanding of the pathomechanism to aid in more precise clinical diagnosis. Securing the patient’s airway as well as administration of an officially approved therapy is of utmost importance. As the number of patients simultaneously treated with antihypertensive and antidiabetic drugs is likely to increase, the incidence of bradykinin mediated drug induced angioedema is

  4. An interfacial and comparative in vitro study of gastrointestinal lipases and Yarrowia lipolytica LIP2 lipase, a candidate for enzyme replacement therapy.

    PubMed

    Bénarouche, Anaïs; Point, Vanessa; Carrière, Frédéric; Cavalier, Jean-François

    2014-07-01

    Lipolytic activities of Yarrowia lipolytica LIP2 lipase (YLLIP2), human pancreatic (HPL) and dog gastric (DGL) lipases were first compared using lecithin-stabilized triacylglycerol (TAG) emulsions (Intralipid) at various pH and bile salt concentrations. Like DGL, YLLIP2 was able to hydrolyze TAG droplets covered by a lecithin monolayer, while HPL was not directly active on that substrate. These results were in good agreement with the respective kinetics of adsorption on phosphatidylcholine (PC) monomolecular films of the same three lipases, YLLIP2 being the most tensioactive lipase. YLLIP2 adsorption onto a PC monolayer spread at the air/water interface was influenced by pH-dependent changes in the enzyme/lipid interfacial association constant (KAds) which was optimum at pH 6.0 on long-chain egg PC monolayer, and at pH 5.0 on medium chain dilauroylphosphatidylcholine film. Using substrate monolayers (1,2-dicaprin, trioctanoin), YLLIP2 displayed the highest lipolytic activities on both substrates in the 25-35 mN m(-1) surface pressure range. YLLIP2 was active in a large pH range and displayed a pH-dependent activity profile combining DGL and HPL features at pH values found in the stomach (pH 3-5) and in the intestine (pH 6-7), respectively. The apparent maximum activity of YLLIP2 was observed at acidic pH 4-6 and was therefore well correlated with an efficient interfacial binding at these pH levels, whatever the type of interfaces (Intralipid emulsions, substrate or PC monolayers). All these findings support the use of YLLIP2 in enzyme replacement therapy for the treatment of pancreatic exocrine insufficiency, a pathological situation in which an acidification of intestinal contents occurs. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  5. Preclinical toxicity evaluation of erythrocyte-encapsulated thymidine phosphorylase in BALB/c mice and beagle dogs: an enzyme-replacement therapy for mitochondrial neurogastrointestinal encephalomyopathy.

    PubMed

    Levene, Michelle; Coleman, David G; Kilpatrick, Hugh C; Fairbanks, Lynette D; Gangadharan, Babunilayam; Gasson, Charlotte; Bax, Bridget E

    2013-01-01

    Erythrocyte-encapsulated thymidine phosphorylase (EE-TP) is currently under development as an enzyme replacement therapy for mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), an autosomal recessive disorder caused by a deficiency of thymidine phosphorylase. The rationale for the development of EE-TP is based on the pathologically elevated metabolites (thymidine and deoxyuridine) being able to freely diffuse across the erythrocyte membrane where the encapsulated enzyme catalyses their metabolism to the normal products. The systemic toxic potential of EE-TP was assessed when administered intermittently by iv bolus injection to BALB/c mice and Beagle dogs for 4 weeks. The studies consisted of one control group receiving sham-loaded erythrocytes twice weekly and two treated groups, one dosed once every 2 weeks and the other dosed twice per week. The administration of EE-TP to BALB/c mice resulted in thrombi/emboli in the lungs and spleen enlargement. These findings were also seen in the control group, and there was no relationship to the number of doses administered. In the dog, transient clinical signs were associated with EE-TP administration, suggestive of an immune-based reaction. Specific antithymidine phosphorylase antibodies were detected in two dogs and in a greater proportion of mice treated once every 2 weeks. Nonspecific antibodies were detected in all EE-TP-treated animals. In conclusion, these studies do not reveal serious toxicities that would preclude a clinical trial of EE-TP in patients with MNGIE, but caution should be taken for infusion-related reactions that may be related to the production of nonspecific antibodies or a cell-based immune response.

  6. Enzyme replacement therapy with velmanase alfa (human recombinant alpha-mannosidase): Novel global treatment response model and outcomes in patients with alpha-mannosidosis.

    PubMed

    Harmatz, Paul; Cattaneo, Federica; Ardigò, Diego; Geraci, Silvia; Hennermann, Julia B; Guffon, Nathalie; Lund, Allan; Hendriksz, Christian J; Borgwardt, Line

    2018-06-01

    Alpha-mannosidosis is an ultra-rare monogenic disorder resulting from a deficiency in the lysosomal enzyme alpha-mannosidase, with a prevalence estimated to be as low as 1:1,000,000 live births. The resulting accumulation of mannose-rich oligosaccharides in all tissues leads to a very heterogeneous disorder with a continuum of clinical manifestations with no distinctive phenotypes. Long-term enzyme replacement therapy (ERT) with velmanase alfa is approved in Europe for the treatment of non-neurological manifestations in patients with mild to moderate alpha-mannosidosis. The clinical heterogeneity and rarity of the disease limit the sensitivity of single parameters to detect clinically relevant treatment effects. Thus, we propose a novel multiple variable responder analysis to evaluate the efficacy of ERT for alpha-mannosidosis and present efficacy analyses for velmanase alfa using this method. Global treatment response to velmanase alfa (defined by response to ≥2 domains comprising pharmacodynamic, functional, and quality of life outcomes) was applied post hoc to data from the pivotal placebo-controlled rhLAMAN-05 study and to the longer-term integrated data from all patients in the clinical development program (rhLAMAN-10). After 12 months of treatment, a global treatment response was achieved by 87% of patients receiving velmanase alfa (n = 15) compared with 30% of patients receiving placebo (n = 10). Longer-term data from all patients in the clinical program (n = 33) showed 88% of patients were global responders, including all (100%) pediatric patients (n = 19) and the majority (71%) of adult patients (n = 14). The responder analysis model demonstrates a clinically meaningful treatment effect with velmanase alfa and supports the early initiation and continued benefit of longer-term treatment of all patients with alpha-mannosidosis with this ERT. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Multifactorial resistance to aminopeptidase inhibitor prodrug CHR2863 in myeloid leukemia cells: down-regulation of carboxylesterase 1, drug sequestration in lipid droplets and pro-survival activation ERK/Akt/mTOR

    PubMed Central

    Verbrugge, Sue Ellen; Al, Marjon; Assaraf, Yehuda G.; Kammerer, Sarah; Chandrupatla, Durga M.S.H.; Honeywell, Richard; Musters, Rene P.J.; Giovannetti, Elisa; O'Toole, Tom; Scheffer, George L.; Krige, David; de Gruijl, Tanja D.; Niessen, Hans W.M.; Lems, Willem F.; Kramer, Pieternella A.; Scheper, Rik J.; Cloos, Jacqueline; Ossenkoppele, Gert J.; Peters, Godefridus J.; Jansen, Gerrit

    2016-01-01

    Aminopeptidase inhibitors are receiving attention as combination chemotherapeutic agents for the treatment of refractory acute myeloid leukemia. However, the factors determining therapeutic efficacy remain elusive. Here we identified the molecular basis of acquired resistance to CHR2863, an orally available hydrophobic aminopeptidase inhibitor prodrug with an esterase-sensitive motif, in myeloid leukemia cells. CHR2863 enters cells by diffusion and is retained therein upon esterase activity-mediated conversion to its hydrophilic active metabolite drug CHR6768, thereby exerting amino acid depletion. Carboxylesterases (CES) serve as candidate prodrug activating enzymes given CES1 expression in acute myeloid leukemia specimens. We established two novel myeloid leukemia sublines U937/CHR2863(200) and U937/CHR2863(5uM), with low (14-fold) and high level (270-fold) CHR2863 resistance. The latter drug resistant cells displayed: (i) complete loss of CES1-mediated drug activation associated with down-regulation of CES1 mRNA and protein, (ii) marked retention/sequestration of the prodrug, (iii) a substantial increase in intracellular lipid droplets, and (iv) a dominant activation of the pro-survival Akt/mTOR pathway. Remarkably, the latter feature coincided with a gain of sensitivity to the mTOR inhibitor rapamycin. These finding delineate the molecular basis of CHR2863 resistance and offer a novel modality to overcome this drug resistance in myeloid leukemia cells. PMID:26496029

  8. Electrochemical Detection of Platinum(IV) Prodrug Satraplatin in Serum.

    PubMed

    Wu, Yao; Lai, Rebecca Y

    2015-11-03

    We report the design and fabrication of a reagentless and reusable electrochemical sensor for detection of satraplatin (SAT), a platinum(IV) prodrug. The detection strategy is based on the electrocatalytic reaction between the Pt(IV) center of SAT and surface-immobilized methylene blue. We systematically evaluated the effect of passivating diluent chain length on the overall sensor performance. Our results show that the use of a shorter diluent like 2-mercaptoethanol is more advantageous than using a longer and more passivating diluent such as 6-mercapto-1-hexanol. Independent of the use of cyclic voltammetry or chronoamperometry as the sensor interrogation technique, all three sensors, each passivated with a different alkanethiol diluent, have been demonstrated to be sensitive; the limit of detection is in the range of 1-10 μM. They are also highly specific and do not respond to Pt(II) drugs such as cisplatin and carboplatin. More importantly, they are selective enough to be employed directly in 50% serum. This sensing strategy has potential applications in clinical pharmacokinetics studies.

  9. Stability of penethamate, a benzylpenicillin ester prodrug, in oily vehicles.

    PubMed

    Jain, Rohit; Bork, Olaf; Tucker, Ian G

    2015-01-01

    Penethamate (PNT) is an ester prodrug of benzylpenicillin which is marketed as dry powder for reconstitution with aqueous vehicle prior to injection. The purpose of this paper was to investigate the chemical stability of PNT in oily formulations to provide a basis for a ready-to-use (RTU) oil-based PNT formulation. The chemical stability of PNT solutions and suspensions in light liquid paraffin (LP), medium chain triglyceride (MIG), ethyl oleate (EO) and sunflower oil (SO) was investigated at 30 °C. Solid state stability of PNT powder and stability of PNT in EO suspensions with different moisture contents were also evaluated. The solubility of PNT in the oils was in order SO > EO > MIG > LP. Degradation of PNT was rapid in oily solutions and less than 10% remained after 7-15 days. Stability of PNT decreased with increase in moisture content in ethyl oleate suspensions. PNT was stable over four weeks in the solid state. Hydrolysis, due to moisture in the oil formulation is not the only degradation mechanism. PNT stability (% drug remaining) in oily suspensions after 3.5 months was in the order LP (96.2%) > MIG (95.4%) > EO (94.1%) > SO (86%). A shelf-life of up to 5.5 years at 30 °C may be achieved for PNT suspension in these oils.

  10. Structure of ThiM from Vitamin B1 biosynthetic pathway of Staphylococcus aureus - Insights into a novel pro-drug approach addressing MRSA infections

    NASA Astrophysics Data System (ADS)

    Drebes, Julia; Künz, Madeleine; Windshügel, Björn; Kikhney, Alexey G.; Müller, Ingrid B.; Eberle, Raphael J.; Oberthür, Dominik; Cang, Huaixing; Svergun, Dmitri I.; Perbandt, Markus; Betzel, Christian; Wrenger, Carsten

    2016-03-01

    Infections caused by the methicillin-resistant Staphylococcus aureus (MRSA) are today known to be a substantial threat for global health. Emerging multi-drug resistant bacteria have created a substantial need to identify and discover new drug targets and to develop novel strategies to treat bacterial infections. A promising and so far untapped antibiotic target is the biosynthesis of vitamin B1 (thiamin). Thiamin in its activated form, thiamin pyrophosphate, is an essential co-factor for all organisms. Therefore, thiamin analogous compounds, when introduced into the vitamin B1 biosynthetic pathway and further converted into non-functional co-factors by the bacterium can function as pro-drugs which thus block various co-factor dependent pathways. We characterized one of the key enzymes within the S. aureus vitamin B1 biosynthetic pathway, 5-(hydroxyethyl)-4-methylthiazole kinase (SaThiM; EC 2.7.1.50), a potential target for pro-drug compounds and analyzed the native structure of SaThiM and complexes with the natural substrate 5-(hydroxyethyl)-4-methylthiazole (THZ) and two selected substrate analogues.

  11. Intein-mediated site-specific synthesis of tumor-targeting protein delivery system: Turning PEG dilemma into prodrug-like feature

    PubMed Central

    Chen, Yingzhi; Zhang, Meng; Jin, Hongyue; Tang, Yisi; Wang, Huiyuan; Xu, Qin; Li, Yaping; Li, Feng; Huang, Yongzhuo

    2017-01-01

    Poor tumor-targeted and cytoplasmic delivery is a bottleneck for protein toxin-based cancer therapy. Ideally, a protein toxin drug should remain stealthy in circulation for prolonged half-life and reduced side toxicity, but turn activated at tumor. PEGylation is a solution to achieve the first goal, but creates a hurdle for the second because PEG rejects interaction between the drugs and tumor cells therein. Such PEG dilemma is an unsolved problem in protein delivery. Herein proposed is a concept of turning PEG dilemma into prodrug-like feature. A site-selectively PEGylated, gelatinase-triggered cell-penetrating trichosanthin protein delivery system is developed with three specific aims. The first is to develop an intein-based ligation method for achieving site-specific modification of protein toxins. The second is to develop a prodrug feature that renders protein toxins remaining stealthy in blood for reduced side toxicity and improved EPR effect. The third is to develop a gelatinase activatable cell-penetration strategy for enhanced tumor targeting and cytoplasmic delivery. Of note, site-specific modification is a big challenge in protein drug research, especially for such a complicated, multifunctional protein delivery system. We successfully develop a protocol for constructing a macromolecular prodrug system with intein-mediated ligation synthesis. With an on-column process of purification and intein-mediated cleavage, the site-specific PEGylation then can be readily achieved by conjugation with the activated C-terminus, thus constructing a PEG-capped, cell-penetrating trichosanthin system with a gelatinase-cleavable linker that enables tumor-specific activation of cytoplasmic delivery. It provides a promising method to address the PEG dilemma for enhanced protein drug delivery, and importantly, a facile protocol for site-specific modification of such a class of protein drugs for improving their druggability and industrial translation. PMID:27914267

  12. Disease Progression Modeling to Evaluate the Effects of Enzyme Replacement Therapy on Kidney Function in Adult Patients with the Classic Phenotype of Fabry Disease.

    PubMed

    Nowak, Albina; Koch, Gilbert; Huynh-Do, Uyen; Siegenthaler, Martin; Marti, Hans-Peter; Pfister, Marc

    2017-01-01

    Fabry disease (FD) is a rare inherited lysosomal storage disease with common and serious kidney complications. Enzyme replacement therapies (ERT) with agalsidase-α and -β were investigated to characterize their therapeutic effect on kidney function in FD patients with Classic phenotype. The prospective FD cohort consisted of 98 genetically confirmed patients (females, n = 61, males, n = 37). The median [interquartile range] follow-up time (time difference from first to last visit) was 9 [6, 12] years. The median age of ERT start was 36 [21 - 54] years for females and 39 [28 - 49] years for males. A disease progression model was developed to (i) characterize the time course of estimated glomerular filtration rate (eGFR) and (ii) evaluate therapeutic effects of ERT on kidney function. Change in eGFR over time was best described by the linear model. Females had stable kidney function with and without ERT (eGFR slopes of -0.07 ml/min/1.73m^2 per year and 0.52 ml/min/1.73m^2 per year, respectively). Males with ERT showed an eGFR decrease of -3.07 ml/min/1.73m^2 per year. Mathematical disease progression modeling indicates that there is no clear therapeutic effect of ERT on kidney function in adult patients with Classic Phenotype of FD. Interpretation of these findings should take into account that the study is not randomized and lacks a placebo controlled group. Further investigations are warranted to clarify whether earlier ERT initiation before 18 years of age, higher ERT dose or more intensive therapies can preserve kidney function. © 2017 The Author(s)Published by S. Karger AG, Basel.

  13. Effects of enzyme-replacement therapy in patients with Anderson-Fabry disease: a prospective long-term cardiac magnetic resonance imaging study.

    PubMed

    Imbriaco, M; Pisani, A; Spinelli, L; Cuocolo, A; Messalli, G; Capuano, E; Marmo, M; Liuzzi, R; Visciano, B; Cianciaruso, B; Salvatore, M

    2009-07-01

    Anderson-Fabry disease is a multisystem X linked disorder of lipid metabolism frequently associated with cardiac symptoms, including left ventricular (LV) hypertrophy gradually impairing cardiac function. Evidence showing that enzyme-replacement therapy (ERT) can be effective in reducing LV hypertrophy and improving myocardial function in the long term is limited. This study aimed to assess the long-term effects of ERT with recombinant alpha-galactosidase A (agalsidase beta, Fabrazyme) on LV function and myocardial signal intensity in 11 patients with Anderson-Fabry disease. Eleven patients (eight males, three females) with varying stages of genetically confirmed Anderson-Fabry disease were examined by means of physical examination and magnetic resonance imaging before ERT with agalsidase beta at 1 mg/kg every other week (study 1) and after a mean treatment duration of 45 months (study 2). At 45 months of treatment, LV mass and LV wall thickness had significantly reduced: 188 (SD 60) g versus 153 (47) g, and 16 (4) mm versus 14 (4) mm, respectively. Furthermore, a significant reduction in myocardial T2 relaxation times was noted in all myocardial regions, that is, interventricular septum 80 (5) ms versus 66 (8) ms, apex 79 (10) ms versus 64 (10) ms, and lateral wall 80 (8) ms versus 65 (16) ms. Changes in LV ejection fraction were not significant. Amelioration of clinical symptoms was observed in all patients. Long-term therapy with agalsidase beta at 1 mg/kg every 2 weeks was effective in significantly reducing LV hypertrophy, improving overall cardiac performance and ameliorating clinical symptoms in patients with Anderson-Fabry disease.

  14. Risk factors for severe clinical events in male and female patients with Fabry disease treated with agalsidase beta enzyme replacement therapy: Data from the Fabry Registry.

    PubMed

    Hopkin, Robert J; Cabrera, Gustavo; Charrow, Joel; Lemay, Roberta; Martins, Ana Maria; Mauer, Michael; Ortiz, Alberto; Patel, Manesh R; Sims, Katherine; Waldek, Stephen; Warnock, David G; Wilcox, William R

    2016-09-01

    Fabry disease, an X-linked lysosomal storage disorder, causes intracellular accumulation of glycosphingolipids leading to progressive renal, cardiovascular, and cerebrovascular disease, and premature death. This longitudinal Fabry Registry study analyzed data from patients with Fabry disease to determine the incidence and type of severe clinical events following initiation of enzyme replacement therapy (ERT) with agalsidase beta, as well as risk factors associated with occurrence of these events. Severe events assessed included chronic dialysis, renal transplantation, cardiac events, stroke, and death. The analyses included 969 male and 442 female Fabry patients. The mean age at first agalsidase beta infusion was 35 and 44, and median treatment follow-up 4.3years and 3.2years, respectively. Among males, cardiac events were the most common on-ERT events, followed by renal, stroke, and non-cardiac death. Among females, cardiac events were also most common followed by stroke and renal events. Patients with on-ERT events had significantly more advanced cardiac and renal disease at baseline as compared with patients without on-ERT events. Severe events were also associated with older age at ERT initiation (males and females), a history of pre-ERT events (females; approaching statistical significance in males), and a higher urinary protein/creatinine ratio (females). Approximately 65% of patients with pre-ERT events did not experience subsequent on-ERT events. Of patients without pre-ERT events, most (84% of males, 92% of females) remained event-free. Patients with on-ERT severe events had more advanced Fabry organ involvement at baseline than those without such events and patients who initiated ERT at a younger age had less residual risk of on-ERT events. The observed patterns of residual risk may aid clinicians in multidisciplinary monitoring of male and female patients with Fabry disease receiving ERT, and in determining the need for administration of adjunctive

  15. Prognostic importance of early worsening renal function after initiation of angiotensin-converting enzyme inhibitor therapy in patients with cardiac dysfunction.

    PubMed

    Testani, Jeffrey M; Kimmel, Stephen E; Dries, Daniel L; Coca, Steven G

    2011-11-01

    Worsening renal function (WRF) in the setting of heart failure has been associated with increased mortality. However, it is unclear if this decreased survival is a direct result of the reduction in glomerular filtration rate (GFR) or if the mechanism underlying the deterioration in GFR is driving prognosis. Given that WRF in the setting of angiotensin-converting enzyme inhibitor (ACE-I) initiation is likely mechanistically distinct from spontaneously occurring WRF, we investigated the relative early WRF-associated mortality rates in subjects randomized to ACE-I or placebo. Subjects in the Studies Of Left Ventricular Dysfunction (SOLVD) limited data set (n=6337) were studied. The interaction between early WRF (decrease in estimated GFR ≥20% at 14 days), randomization to enalapril, and mortality was the primary end point. In the overall population, early WRF was associated with increased mortality (adjusted hazard ratio [HR], 1.2; 95% CI, 1.0-1.4; P=0.037). When analysis was restricted to the placebo group, this association strengthened (adjusted HR, 1.4; 95% CI, 1.1-1.8; P=0.004). However, in the enalapril group, early WRF had no adverse prognostic significance (adjusted HR, 1.0; 95% CI, 0.8-1.3; P=1.0; P=0.09 for the interaction). In patients who continued to receive study drug despite early WRF, a survival advantage remained with enalapril therapy (adjusted HR, 0.66; 95% CI, 0.5-0.9; P=0.018). These data support the notion that the mechanism underlying WRF is important in determining its prognostic significance. Specifically, early WRF in the setting of ACE-I initiation appears to represent a benign event that is not associated with a loss of benefit from continued ACE-I therapy.

  16. Angiotensin-converting enzyme-inhibitor therapy in adolescents with type 1 diabetes in a regional cohort: Auckland, New Zealand from 2006 to 2016.

    PubMed

    Hornung, Rosalie J; Reed, Peter W; Mouat, Fran; Jefferies, Craig; Gunn, Alistair J; Hofman, Paul L

    2018-05-01

    To review indications and use of angiotensin-converting enzyme-inhibitor (ACEI) therapy for the treatment of persistent microalbuminuria (MA) and/or hypertension (HTN) in adolescents with type 1 diabetes mellitus (T1DM). Retrospective chart review of adolescent patients with T1DM seen within the paediatric diabetes service in Auckland, New Zealand, from 2006 to 2016. MA, HTN, patient demographic characteristics and ACEI prescribing and monitoring indices were examined. Five hundred adolescents with T1DM were included. There were 26 patients (5%) with MA and/or HTN. MA alone was present in 16, HTN alone in 3 and both HTN and MA in 7. The 5-year MA/HTN-free rate was 98%, and the 10-year MA/HTN-free rate was 93%. Longer disease duration and earlier diagnosis were predictors of MA/HTN. There was no significant difference in standard clinical indices between study patients and others. ACEI was prescribed for 17 of 26 patients for either HTN or MA. Within 6 weeks of ACEI commencement, less than half of the subjects had repeat serum creatinine and MA screens and no record of repeat blood pressure measurement. Despite this, all patients had 3-monthly reviews within outpatient clinics where adjustments of ACEI doses were made. In our regional adolescent population with T1DM, there were low rates of both MA and/or HTN. In those who required treatment with ACEI, clinical monitoring post-commencement of therapy was inconsistent. Local consensus guidelines for the management of persistent MA in children and adolescents with diabetes mellitus were developed in response to this study. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

  17. A prodrug micellar carrier assembled from polymers with pendant farnesyl thiosalicylic acid moieties for improved delivery of paclitaxel.

    PubMed

    Sun, Jingjing; Chen, Yichao; Li, Ke; Huang, Yixian; Fu, Xiaofeng; Zhang, Xiaolan; Zhao, Wenchen; Wei, Yuan; Xu, Liang; Zhang, Peijun; Venkataramanan, Raman; Li, Song

    2016-10-01

    In order to achieve enhanced and synergistic delivery of paclitaxel (PTX), a hydrophobic anticancer agent, two novel prodrug copolymers, POEG15-b-PFTS6 and POEG15-b-PFTS16 composed of hydrophilic poly(oligo(ethylene glycol) methacrylate) (POEG) and hydrophobic farnesylthiosalicylate (FTS, a nontoxic Ras antagonist) blocks, were synthesized. Both POEG-b-PFTS polymers were able to form micelles with intrinsic antitumor activity in vitro and in vivo. Employing these micelles as a carrier to load PTX, their drug loading capacity, stability, in vivo biodistribution and tumor inhibition effect were evaluated. PTX/POEG15-b-PFTS16 mixed micelles exhibited an excellent stability of 9days at 4°C with a PTX loading capacity of 8.2%, which was more effective than PTX/POEG15-b-PFTS6 mixed micelles. In vivo biodistribution data showed that DiR-loaded POEG-b-PFTS micelles were more effectively localized in the tumor than in other organs. Moreover, both PTX/POEG-b-PFTS micelles showed significantly higher antitumor activity than Taxol in a 4T1.2 murine breast tumor model, and the tumor inhibition and animal survival followed the order of PTX/POEG15-b-PFTS16>PTX/POEG15-b-PFTS6>POEG15-b-PFTS16>Taxol≈POEG15-b-PFTS6. Our data suggest that POEG-b-PFTS micelles are a promising anticancer drug carrier that warrants more studies in the future. Polymerization of drug-based monomer represents a facile and precise method to obtain well-defined polymeric prodrug amphiphiles. Currently, most reports largely focus on the synthesis methods and the biophysical properties. There is limited information about their anti-tumor activity and delivery function as prodrug carriers in vitro and in vivo. In this manuscript, we report the development of two novel prodrug copolymers, POEG15-b-PFTS6 and POEG15-b-PFTS16 composed of hydrophilic poly(oligo(ethylene glycol) methacrylate) (POEG) and hydrophobic farnesylthiosalicylate (FTS, a nontoxic Ras antagonist) blocks. Both POEG-b-PFTS polymers were able

  18. Activity of the hypoxia-activated prodrug, TH-302, in preclinical human acute myeloid leukemia models.

    PubMed

    Portwood, Scott; Lal, Deepika; Hsu, Yung-Chun; Vargas, Rodrigo; Johnson, Megan K; Wetzler, Meir; Hart, Charles P; Wang, Eunice S

    2013-12-01

    Acute myeloid leukemia (AML) is an aggressive hematologic neoplasm. Recent evidence has shown the bone marrow microenvironment in patients with AML to be intrinsically hypoxic. Adaptive cellular responses by leukemia cells to survive under low oxygenation also confer chemoresistance. We therefore asked whether therapeutic exploitation of marrow hypoxia via the hypoxia-activated nitrogen mustard prodrug, TH-302, could effectively inhibit AML growth. We assessed the effects of hypoxia and TH-302 on human AML cells, primary samples, and systemic xenograft models. We observed that human AML cells and primary AML colonies cultured under chronic hypoxia (1% O2, 72 hours) exhibited reduced sensitivity to cytarabine-induced apoptosis as compared with normoxic controls. TH-302 treatment resulted in dose- and hypoxia-dependent apoptosis and cell death in diverse AML cells. TH-302 preferentially decreased proliferation, reduced HIF-1α expression, induced cell-cycle arrest, and enhanced double-stranded DNA breaks in hypoxic AML cells. Hypoxia-induced reactive oxygen species by AML cells were also diminished. In systemic human AML xenografts (HEL, HL60), TH-302 [50 mg/kg intraperitoneally (i.p.) 5 times per week] inhibited disease progression and prolonged overall survival. TH-302 treatment reduced the number of hypoxic cells within leukemic bone marrows and was not associated with hematologic toxicities in nonleukemic or leukemic mice. Later initiation of TH-302 treatment in advanced AML disease was as effective as earlier TH-302 treatment in xenograft models. Our results establish the preclinical activity of TH-302 in AML and provide the rationale for further clinical studies of this and other hypoxia-activated agents for leukemia therapy. ©2013 AACR.

  19. Click polymerization for the synthesis of reduction-responsive polymeric prodrug

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaojin; Wang, Hongquan; Dai, Yu

    2018-05-01

    Click polymerization is a powerful polymerization technique for the construction of new macromolecules with well-defined structures and multifaceted functionalities. Here, we synthesize reduction-responsive polymeric prodrug PEG- b-(PSS- g-MTX)- b-PEG containing disulfide bonds and pendant methotrexate (MTX) via two-step click polymerization followed by conjugating MTX to pendant hydroxyl. MTX content in polymeric prodrug is 13.5%. Polymeric prodrug is able to form polymeric micelles by self-assembly in aqueous solution. Polymeric micelles are spherical nanoparticles with tens of nanometers in size. Of note, polymeric micelles are reduction-responsive due to disulfide bonds in the backbone of PEG- b-(PSS- g-MTX)- b-PEG and could release pendant drugs in the presence of the reducing agents such as dl-dithiothreitol (DTT).

  20. Development of Platinum(iv) Complexes as Anticancer Prodrugs: the Story so Far

    NASA Astrophysics Data System (ADS)

    Wong, Daniel Yuan Qiang; Ang, Wee Han

    2012-06-01

    The serendipitous discovery of the antitumor properties of cisplatin by Barnett Rosenberg some forty years ago brought about a paradigm shift in the field of medicinal chemistry and challenged conventional thinking regarding the role of potentially toxic heavy metals in drugs. Platinum(II)-based anticancer drugs have since become some of the most effective and widely-used drugs in a clinician's arsenal and have saved countless lives. However, they are limited by high toxicity, severe side-effects and the incidence of drug resistance. In recent years, attention has shifted to stable platinum(IV) complexes as anticancer prodrugs. By exploiting the unique chemical and structural attributes of their scaffolds, these platinum(IV) prodrugs offer new strategies of targeting and killing cancer cells. This review summarizes the development of anticancer platinum(IV) prodrugs to date and some of the exciting strategies that utilise the platinum(IV) construct as targeted chemotherapeutic agents against cancer.

  1. Gastric-sparing nitric oxide-releasable 'true' prodrugs of aspirin and naproxen.

    PubMed

    Gund, Machhindra; Gaikwad, Parikshit; Borhade, Namdev; Burhan, Aslam; Desai, Dattatraya C; Sharma, Ankur; Dhiman, Mini; Patil, Mohan; Sheikh, Javed; Thakre, Gajanan; Tipparam, Santhosh G; Sharma, Somesh; Nemmani, Kumar V S; Satyam, Apparao

    2014-12-15

    Nitric oxide-releasing non-steroidal anti-inflammatory drugs (NO-NSAIDs) are gaining attention as potentially gastric-sparing NSAIDs. Herein, we report a novel class of '1-(nitrooxy)ethyl ester' group-containing NSAIDS as efficient NO releasing 'true' prodrugs of aspirin and naproxen. While an aspirin prodrug exhibited comparable oral bioavailability and antiplatelet activity (i.e., TXB2 inhibition) to those of aspirin, a naproxen prodrug exhibited better bioavailability than naproxen. These promising NO-NSAIDs protected experimental rats from gastric damage. We therefore believe that these promising NO-NSAIDs could represent a new class of potentially 'Safe NSAIDs' for the treatment of arthritic pain, inflammation and cardiovascular disorders in the case of NO-aspirin. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Amphiphilic naproxen prodrugs: differential scanning calorimetry study on their interaction with phospholipid bilayers.

    PubMed

    Giuffrida, Maria Chiara; Pignatello, Rosario; Castelli, Francesco; Sarpietro, Maria Grazia

    2017-09-01

    Naproxen, a nonsteroid anti-inflammatory drug studied for Alzheimer's disease, was conjugated with lipoamino acids (LAA) directly or through a diethylamine (EDA) spacer to improve the drug lipophilicity and the interaction with phospholipid bilayers. The interaction of naproxen and its prodrugs with biomembrane models consisting of dimyristoylphosphatidylcholine multilamellar vesicles was studied by differential scanning calorimetry. The transfer of prodrugs from a lipophilic carrier to a biomembrane model was also studied. Naproxen conjugation to lipoamino acids improves its interaction with biomembrane models and affects the transfer from a lipophilic carrier to biomembrane model. LAA portion may localize between the phospholipid chains; the entity of the interaction depends not only on the presence of the spacer but also on the LAA chain length. Variation of LAA portion can modulate the naproxen prodrugs affinity towards the biological membrane as well as towards the lipophilic carrier. © 2017 Royal Pharmaceutical Society.

  3. Enzyme replacement therapy improves joint motion and outcome of the 12-min walk test in a mucopolysaccharidosis type VI patient previously treated with bone marrow transplantation.

    PubMed

    Sohn, Young Bae; Park, Sung Won; Kim, Se-Hwa; Cho, Sung-Yoon; Ji, Sun-Tae; Kwon, Eun Kyung; Han, Sun Ju; Oh, Se Jung; Park, Yong Jae; Ko, Ah-Ra; Paik, Kyung-Hoon; Lee, Jeehun; Lee, Dong Hwan; Jin, Dong-Kyu

    2012-05-01

    Mucopolysaccharidosis type VI (MPS VI; Maroteaux-Lamy syndrome, OMIM #253200) is a rare disorder involving multiple organs and manifested particularly by severe skeletal abnormalities. Bone marrow transplantation (BMT) improves cardiopulmonary function and facial features, but has limited success in ameliorating skeletal abnormalities and short stature. Here, we report the outcome of enzyme replacement therapy (ERT) with recombinant human arylsulfatase-B (ASB, Naglazyme, BioMarin, Novato, CA) in an MPS VI patient who received BMT 10 years prior to ERT induction. Administration of weekly Naglazyme for 18 months was effective in improving range of motion in several joints [shoulders (improvement of flexion (Right/Left): 40°/55°; improvement of extension 30°/40°; improvement of abduction 10°/10°), elbows (improvement of flexion 25°/25°; improvement of extension 10°/15°), hips (improvement of flexion 25°/10°), and knees (improvement of flexion 45°/40°; improvement of extension 50°/60°)]. Improvement in the outcome of the 12-min walk test (70% increase) and 3-min stair-climbing test (29% increase) was also noted after ERT. Because ERT improved clinical features in an MPS VI patient who had undergone prior BMT, the role of ERT post successful BMT in MPS VI needs further investigation. Copyright © 2012 Wiley Periodicals, Inc.

  4. Quantitative Systems Pharmacology Modeling of Acid Sphingomyelinase Deficiency and the Enzyme Replacement Therapy Olipudase Alfa Is an Innovative Tool for Linking Pathophysiology and Pharmacology.

    PubMed

    Kaddi, Chanchala D; Niesner, Bradley; Baek, Rena; Jasper, Paul; Pappas, John; Tolsma, John; Li, Jing; van Rijn, Zachary; Tao, Mengdi; Ortemann-Renon, Catherine; Easton, Rachael; Tan, Sharon; Puga, Ana Cristina; Schuchman, Edward H; Barrett, Jeffrey S; Azer, Karim

    2018-06-19

    Acid sphingomyelinase deficiency (ASMD) is a rare lysosomal storage disorder with heterogeneous clinical manifestations, including hepatosplenomegaly and infiltrative pulmonary disease, and is associated with significant morbidity and mortality. Olipudase alfa (recombinant human acid sphingomyelinase) is an enzyme replacement therapy under development for the non-neurological manifestations of ASMD. We present a quantitative systems pharmacology (QSP) model supporting the clinical development of olipudase alfa. The model is multiscale and mechanistic, linking the enzymatic deficiency driving the disease to molecular-level, cellular-level, and organ-level effects. Model development was informed by natural history, and preclinical and clinical studies. By considering patient-specific pharmacokinetic (PK) profiles and indicators of disease severity, the model describes pharmacodynamic (PD) and clinical end points for individual patients. The ASMD QSP model provides a platform for quantitatively assessing systemic pharmacological effects in adult and pediatric patients, and explaining variability within and across these patient populations, thereby supporting the extrapolation of treatment response from adults to pediatrics. © 2018 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  5. [Shift of focus in the financing of Hungarian drugs. Reimbursement for orphan drugs for treating rare diseases: financing of enzyme replacement therapy in Hungary].

    PubMed

    Szegedi, Márta; Molnár, Mária Judit; Boncz, Imre; Kosztolányi, György

    2014-11-02

    Focusing on the benefits of patients with rare disease the authors analysed the aspects of orphan medicines financed in the frame of the Hungarian social insurance system in 2012 in order to make the consumption more rational, transparent and predictable. Most of the orphan drugs were financed in the frame of compassionate use by the reimbursement system. Consequently, a great deal of crucial problems occurred in relation to the unconventional subsidized method, especially in the case of the highest cost enzyme replacement therapies. On the base of the findings, proposals of the authors are presented for access to orphan drugs, fitting to the specific professional, economical and ethical aspects of this unique field of the health care system. The primary goal is to provide a suitable subsidized method for the treatment of rare disease patients with unmet medical needs. The financial modification of orphans became indispensible in Hungary. Professionals from numerous fields dealing with rare disease patients' care expressed agreement on the issue. Transforming the orphan medicines' financial structure has been initiated according to internationally shared principles.

  6. Catechin prodrugs and analogs: a new array of chemical entities with improved pharmacological and pharmacokinetic properties.

    PubMed

    Bansal, Sumit; Vyas, Sandeep; Bhattacharya, Shoumyo; Sharma, Manu

    2013-10-11

    Extensive research on tea catechins, mainly (-)-epigallocatechin gallate, has shown numerous health promoting effects. However, various clinical studies demonstrated several issues associated with tea catechins which account for their poor systemic bioavailability. In order to improve pharmacological activity and bioavailability of natural tea catechins, two major strategies have been adopted to date which include synthesizing catechin analogs/prodrugs and the development of novel drug delivery systems. In this review, we provide a detailed account of novel synthetic analogs/prodrugs as well as novel drug delivery approaches used for natural tea catechins to make them therapeutically potent drug-like molecules.

  7. Pyruvate sensitizes pancreatic tumors to hypoxia-activated prodrug TH-302.

    PubMed

    Wojtkowiak, Jonathan W; Cornnell, Heather C; Matsumoto, Shingo; Saito, Keita; Takakusagi, Yoichi; Dutta, Prasanta; Kim, Munju; Zhang, Xiaomeng; Leos, Rafael; Bailey, Kate M; Martinez, Gary; Lloyd, Mark C; Weber, Craig; Mitchell, James B; Lynch, Ronald M; Baker, Amanda F; Gatenby, Robert A; Rejniak, Katarzyna A; Hart, Charles; Krishna, Murali C; Gillies, Robert J

    2015-01-01

    Hypoxic niches in solid tumors harbor therapy-resistant cells. Hypoxia-activated prodrugs (HAPs) have been designed to overcome this resistance and, to date, have begun to show clinical efficacy. However, clinical HAPs activity could be improved. In this study, we sought to identify non-pharmacological methods to acutely exacerbate tumor hypoxia to increase TH-302 activity in pancreatic ductal adenocarcinoma (PDAC) tumor models. Three human PDAC cell lines with varying sensitivity to TH-302 (Hs766t > MiaPaCa-2 > SU.86.86) were used to establish PDAC xenograft models. PDAC cells were metabolically profiled in vitro and in vivo using the Seahorse XF system and hyperpolarized (13)C pyruvate MRI, respectively, in addition to quantitative immunohistochemistry. The effect of exogenous pyruvate on tumor oxygenation was determined using electroparamagnetic resonance (EPR) oxygen imaging. Hs766t and MiaPaCa-2 cells exhibited a glycolytic phenotype in comparison to TH-302 resistant line SU.86.86. Supporting this observation is a higher lactate/pyruvate ratio in Hs766t and MiaPaCa xenografts as observed during hyperpolarized pyruvate MRI studies in vivo. Coincidentally, response to exogenous pyruvate both in vitro (Seahorse oxygen consumption) and in vivo (EPR oxygen imaging) was greatest in Hs766t and MiaPaCa models, possibly due to a higher mitochondrial reserve capacity. Changes in oxygen consumption and in vivo hypoxic status to pyruvate were limited in the SU.86.86 model. Combination therapy of pyruvate plus TH-302 in vivo significantly decreased tumor growth and increased survival in the MiaPaCa model and improved survival in Hs766t tumors. Using metabolic profiling, functional imaging, and computational modeling, we show improved TH-302 activity by transiently increasing tumor hypoxia metabolically with exogenous pyruvate. Additionally, this work identified a set of biomarkers that may be used clinically to predict which tumors will be most responsive to

  8. Contamination of the Norepinephrine Prodrug Droxidopa by Dihydroxyphenylacetaldehyde

    PubMed Central

    Holmes, Courtney; Whittaker, Noel; Heredia-Moya, Jorge; Goldstein, David S.

    2015-01-01

    BACKGROUND l-Threo-3,4-dihydroxyphenylserine (L-DOPS, droxidopa) is a norepinephrine (NE) prodrug under development to treat orthostatic hypotension. 3,4-Dihydroxyphenylacetaldehyde (DOPAL), an endogenous catecholaldehyde produced by enzymatic oxidative deamination of dopamine, is toxic to catecholaminergic neurons. Based on the observation of increasing plasma DOPAL after oral administration of L-DOPS to a patient, we examined whether other subjects also had DOPAL in their plasma after droxidopa administration, and whether droxidopa is contaminated with DOPAL. METHODS Thirteen subjects took 400 mg droxidopa orally. We sampled venous blood at baseline and 1, 2, 3, 6, 24, and 48 h after drug administration and assayed L-DOPS, NE, and DOPAL by use of liquid chromatography with electrochemical detection (LC-ED). Droxidopa in acidic solution (20:80 mixture of 0.04 mol/L phosphoric acid:0.20 mol/L acetic acid) was vacuum centrifuged for 1 h at 30 °C and then assayed by LC-ED. RESULTS Droxidopa contained 0.01% DOPAL. At 6 h after droxidopa, all subjects had detectable DOPAL in plasma (1.89 nmol/L, P = 0.0001). Across the sampling times, plasma DOPAL correlated with plasma L-DOPS (r = 0.996). The mean increment in plasma DOPAL was more than 4 times that in plasma NE (0.39 nmol/L). In 2 patients with Parkinson disease and orthostatic hypotension, DOPAL was detected in plasma at baseline (0.12 nmol/L) and increased by about 70-fold after droxidopa. Vacuum concentration of droxidopa in the acid solution converted L-DOPS to DOPAL completely. CONCLUSIONS Droxidopa is contaminated with DOPAL. After oral droxidopa administration, DOPAL is detected in plasma of humans. Droxidopa is susceptible to extensive nonenzymatic conversion to DOPAL. PMID:20207766

  9. Contamination of the norepinephrine prodrug droxidopa by dihydroxyphenylacetaldehyde.

    PubMed

    Holmes, Courtney; Whittaker, Noel; Heredia-Moya, Jorge; Goldstein, David S

    2010-05-01

    L-threo-3,4-dihydroxyphenylserine (L-DOPS, droxidopa) is a norepinephrine (NE) prodrug under development to treat orthostatic hypotension. 3,4-Dihydroxyphenylacetaldehyde (DOPAL), an endogenous catecholaldehyde produced by enzymatic oxidative deamination of dopamine, is toxic to catecholaminergic neurons. Based on the observation of increasing plasma DOPAL after oral administration of L-DOPS to a patient, we examined whether other subjects also had DOPAL in their plasma after droxidopa administration, and whether droxidopa is contaminated with DOPAL. Thirteen subjects took 400 mg droxidopa orally. We sampled venous blood at baseline and 1, 2, 3, 6, 24, and 48 h after drug administration and assayed L-DOPS, NE, and DOPAL by use of liquid chromatography with electrochemical detection (LC-ED). Droxidopa in acidic solution (20:80 mixture of 0.04 mol/L phosphoric acid:0.20 mol/L acetic acid) was vacuum centrifuged for 1 h at 30 degrees C and then assayed by LC-ED. Droxidopa contained 0.01% DOPAL. At 6 h after droxidopa, all subjects had detectable DOPAL in plasma (1.89 nmol/L, P = 0.0001). Across the sampling times, plasma DOPAL correlated with plasma L-DOPS (r = 0.996). The mean increment in plasma DOPAL was more than 4 times that in plasma NE (0.39 nmol/L). In 2 patients with Parkinson disease and orthostatic hypotension, DOPAL was detected in plasma at baseline (0.12 nmol/L) and increased by about 70-fold after droxidopa. Vacuum concentration of droxidopa in the acid solution converted L-DOPS to DOPAL completely. Droxidopa is contaminated with DOPAL. After oral droxidopa administration, DOPAL is detected in plasma of humans. Droxidopa is susceptible to extensive nonenzymatic conversion to DOPAL.

  10. Enzyme Informatics

    PubMed Central

    Alderson, Rosanna G.; Ferrari, Luna De; Mavridis, Lazaros; McDonagh, James L.; Mitchell, John B. O.; Nath, Neetika

    2012-01-01

    Over the last 50 years, sequencing, structural biology and bioinformatics have completely revolutionised biomolecular science, with millions of sequences and tens of thousands of three dimensional structures becoming available. The bioinformatics of enzymes is well served by, mostly free, online databases. BRENDA describes the chemistry, substrate specificity, kinetics, preparation and biological sources of enzymes, while KEGG is valuable for understanding enzymes and metabolic pathways. EzCatDB, SFLD and MACiE are key repositories for data on the chemical mechanisms by which enzymes operate. At the current rate of genome sequencing and manual annotation, human curation will never finish the functional annotation of the ever-expanding list of known enzymes. Hence there is an increasing need for automated annotation, though it is not yet widespread for enzyme data. In contrast, functional ontologies such as the Gene Ontology already profit from automation. Despite our growing understanding of enzyme structure and dynamics, we are only beginning to be able to design novel enzymes. One can now begin to trace the functional evolution of enzymes using phylogenetics. The ability of enzymes to perform secondary functions, albeit relatively inefficiently, gives clues as to how enzyme function evolves. Substrate promiscuity in enzymes is one example of imperfect specificity in protein-ligand interactions. Similarly, most drugs bind to more than one protein target. This may sometimes result in helpful polypharmacology as a drug modulates plural targets, but also often leads to adverse side-effects. Many cheminformatics approaches can be used to model the interactions between druglike molecules and proteins in silico. We can even use quantum chemical techniques like DFT and QM/MM to compute the structural and energetic course of enzyme catalysed chemical reaction mechanisms, including a full description of bond making and breaking. PMID:23116471

  11. Divergent clinical outcomes of alpha-glucosidase enzyme replacement therapy in two siblings with infantile-onset Pompe disease treated in the symptomatic or pre-symptomatic state.

    PubMed

    Matsuoka, Takashi; Miwa, Yoshiyuki; Tajika, Makiko; Sawada, Madoka; Fujimaki, Koichiro; Soga, Takashi; Tomita, Hideshi; Uemura, Shigeru; Nishino, Ichizo; Fukuda, Tokiko; Sugie, Hideo; Kosuga, Motomichi; Okuyama, Torayuki; Umeda, Yoh

    2016-12-01

    Pompe disease is an autosomal recessive, lysosomal glycogen storage disease caused by acid α-glucosidase deficiency. Infantile-onset Pompe disease (IOPD) is the most severe form and is characterized by cardiomyopathy, respiratory distress, hepatomegaly, and skeletal muscle weakness. Untreated, IOPD generally results in death within the first year of life. Enzyme replacement therapy (ERT) with recombinant human acid alpha glucosidase (rhGAA) has been shown to markedly improve the life expectancy of patients with IOPD. However, the efficacy of ERT in patients with IOPD is affected by the presence of symptoms and cross-reactive immunologic material (CRIM) status. We have treated two siblings with IOPD with ERT at different ages: the first was symptomatic and the second was asymptomatic. The female proband (Patient 1) was diagnosed with IOPD and initiated ERT at 4 months of age. Her younger sister (Patient 2) was diagnosed with IOPD at 10 days of age and initiated ERT at Day 12. Patient 1, now 6 years old, is alive but bedridden, and requires 24-hour invasive ventilation due to gradually progressive muscle weakness. In Patient 2, typical symptoms of IOPD, including cardiac failure, respiratory distress, progressive muscle weakness, hepatomegaly and myopathic facial features were largely absent during the first 12 months of ERT. Her cardiac function and mobility were well-maintained for the first 3 years, and she had normal motor development. However, she developed progressive hearing impairment and muscle weakness after 3 years of ERT. Both siblings have had low anti-rhGAA immunoglobulin G (IgG) antibody titers during ERT and have tolerated the treatment well. These results suggest that initiation of ERT during the pre-symptomatic period can prevent and/or attenuate the progression of IOPD, including cardiomyopathy, respiratory distress, and muscle weakness for first several years of ERT. However, to improve the long-term efficacy of ERT for IOPD, new strategies

  12. Use of Cardiac Magnetic Resonance Imaging to Evaluate Cardiac Structure, Function and Fibrosis in Children with Infantile Pompe Disease on Enzyme Replacement Therapy

    PubMed Central

    Barker, Piers C.A.; Pasquali, Sara K.; Darty, Stephen; Ing, Richard J.; Li, Jennifer S.; Kim, Raymond J.; DeArmey, Stephanie; Kishnani, Priya S.; Campbell, Michael J.

    2010-01-01

    Background Pompe disease (acid α-glucosidase deficiency) is one of several lysosomal storage diseases amenable to treatment with enzyme replacement therapy (ERT). While echocardiography (echo) has been the standard method to evaluate the cardiac response to ERT, cardiac magnetic resonance imaging (CMR) has the advantage of better tissue definition and characterization of myocardial fibrosis. However, CMR for Pompe disease is not frequently performed due to the high risk of sedation. We report the first use of CMR in a feasible protocol to quantify left ventricular (LV) mass, function, and presence of myocardial fibrosis in the Pompe population. Methods Children with Pompe disease on ERT were assessed with transthoracic echo and CMR over a 3 year period at a single institution. Echocardiography was performed using standard techniques without sedation. CMR was performed using retrospectively gated and real-time imaging, with and without sedation. LV mass indexed to body surface area (LVMI) and ejection fraction (EF) were measured by both echo and CMR, and evaluated for change over time. Myocardial fibrosis was assessed with CMR by delayed enhancement imaging 5-10 min after gadolinium contrast using single-shot inversion recovery sequences with inversion time set to null the myocardium. Results Seventeen CMR scans were successfully performed in 10 subjects with Pompe disease (median age at first CMR 9 months, range 1-38 months, 80% male), with sedation only performed for 4 studies. There was a median interval of 5 months (range 0-34 months) from start of ERT to first CMR (baseline). At baseline, median indexed LVMI by CMR (140.0 g/m2, range 43.8-334.0) tended to be lower than that assessed by echo (median 204.0 g/m2, range 52.0-385.0), but did not reach statistical significance. At baseline, CMR EF was similar to that assessed by echo (55% vs. 55%). Overall, there was not a significant decrease in CMR measured LVMI over time (CMR median LVMI at baseline 94 g/m2

  13. Use of cardiac magnetic resonance imaging to evaluate cardiac structure, function and fibrosis in children with infantile Pompe disease on enzyme replacement therapy.

    PubMed

    Barker, Piers C A; Pasquali, Sara K; Darty, Stephen; Ing, Richard J; Li, Jennifer S; Kim, Raymond J; DeArmey, Stephanie; Kishnani, Priya S; Campbell, Michael J

    2010-12-01

    Pompe disease (acid α-glucosidase deficiency) is one of several lysosomal storage diseases amenable to treatment with enzyme replacement therapy (ERT). While echocardiography (echo) has been the standard method to evaluate the cardiac response to ERT, cardiac magnetic resonance imaging (CMR) has the advantage of a better tissue definition and characterization of myocardial fibrosis. However, CMR for Pompe disease is not frequently performed due to a high risk of sedation. We report the first use of CMR in a feasible protocol to quantify left ventricular (LV) mass, function, and the presence of myocardial fibrosis in the Pompe population. Children with Pompe disease on ERT were assessed with transthoracic echo and CMR over a 3 year period at a single institution. Echocardiography was performed using standard techniques without sedation. CMR was performed using retrospectively gated and real-time imaging, with and without sedation. LV mass indexed to body surface area (LVMI) and ejection fraction (EF) were measured by both echo and CMR, and evaluated for change over time. Myocardial fibrosis was assessed by CMR with delayed enhancement imaging 5-10 min after gadolinium contrast using single shot inversion recovery sequences with inversion time set to null the signal from normal myocardium. Seventeen CMR scans were successfully performed in 10 subjects with Pompe disease (median age at first CMR is 9 months, range 1-38 months, 80% male), with sedation only performed in 4 studies. There was a median interval of 5 months (range 0-34 months) from the start of ERT to first CMR (baseline). At baseline, the median indexed LVMI by CMR (140.0 g/m(2), range 43.8-334.0) tended to be lower than that assessed by echo (median 204.0 g/m(2), range 52.0-385.0), but did not reach statistical significance. At baseline, CMR EF was similar to that assessed by echo (55% vs. 55%). Overall, there was no significant decrease in CMR measured LVMI over time (CMR median LVMI at baseline 94 g

  14. Effective gene silencing activity of prodrug-type 2'-O-methyldithiomethyl siRNA compared with non-prodrug-type 2'-O-methyl siRNA.

    PubMed

    Hayashi, Junsuke; Nishigaki, Misa; Ochi, Yosuke; Wada, Shun-Ichi; Wada, Fumito; Nakagawa, Osamu; Obika, Satoshi; Harada-Shiba, Mariko; Urata, Hidehito

    2018-07-01

    Small interfering RNAs (siRNAs) are an active agent to induce gene silencing and they have been studied for becoming a biological and therapeutic tool. Various 2'-O-modified RNAs have been extensively studied to improve the nuclease resistance. However, the 2'-O-modified siRNA activities were often decreased by modification, since the bulky 2'-O-modifications inhibit to form a RNA-induced silencing complex (RISC). We developed novel prodrug-type 2'-O-methyldithiomethyl (MDTM) siRNA, which is converted into natural siRNA in an intracellular reducing environment. Prodrug-type 2'-O-MDTM siRNAs modified at the 5'-end side including 5'-end nucleotide and the seed region of the antisense strand exhibited much stronger gene silencing effect than non-prodrug-type 2'-O-methyl (2'-O-Me) siRNAs. Furthermore, the resistances for nuclease digestion of siRNAs were actually enhanced by 2'-O-MDTM modifications. Our results indicate that 2'-O-MDTM modifications improve the stability of siRNA in serum and they are able to be introduced at any positions of siRNA. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Variations in plasma and urinary lipids in response to enzyme replacement therapy for Fabry disease patients by nanoflow UPLC-ESI-MS/MS.

    PubMed

    Byeon, Seul Kee; Kim, Jin Yong; Lee, Jin-Sung; Moon, Myeong Hee

    2016-03-01

    A deficiency of α-galactosidase A causes Fabry disease (FD) by disrupting lipid metabolism, especially trihexosylceramide (THC). Enzyme replacement therapy (ERT) is clinically offered to FD patients in an attempt to lower the accumulated lipids. Studies on specific types of lipids that are directly or indirectly altered by FD are very scarce, even though they are crucial in understanding the biological process linked to the pathogenesis of FD. We performed a comprehensive lipid profiling of plasma and urinary lipids from FD patients with nanoflow liquid chromatography electrospray-ionization tandem mass spectrometry (nLC-ESI-MS/MS) and identified 129 plasma and 111 urinary lipids. Among these, lipids that exhibited alternations (>twofold) in patients were selected as targets for selected reaction monitoring (SRM)-based high-speed quantitation using nanoflow ultra-performance LC-ESI-MS/MS (nUPLC-ESI-MS/MS) and 31 plasma and 26 urinary lipids showed significant elevation among FD patients. Higher percentages of sphingolipids (SLs; 48% for plasma and 42% for urine) were highly elevated in patients; whereas, a smaller percentage of phospholipids (PLs; 15% for plasma and 13% for urine) were significantly affected. Even though α-galactosidase A is reported to affect THC only, the results show that other classes of lipids (especially SLs) are changed as well, indicating that FD not only alters metabolism of THC but various classes of lipids too. Most lipids showing significant increases in relative amounts before ERT decreased after ERT, but overall, ERT influenced plasma lipids more than urinary lipids.

  16. Effect of enzyme replacement therapy with alglucosidase alfa (Myozyme®) in 12 patients with advanced late-onset Pompe disease.

    PubMed

    Papadopoulos, Constantinos; Orlikowski, David; Prigent, Hélène; Lacour, Arnaud; Tard, Céline; Furby, Alain; Praline, Julien; Solé, Guilhem; Hogrel, Jean-Yves; De Antonio, Marie; Semplicini, Claudio; Deibener-Kaminsky, Joelle; Kaminsky, Pierre; Eymard, Bruno; Taouagh, Nadjib; Perniconi, Barbara; Hamroun, Dalil; Laforêt, Pascal

    2017-09-01

    The efficacy of enzyme replacement therapy (ERT) in patients at an advanced stage of Pompe disease has only been addressed in a few studies. Our objective was to assess the long term effects of ERT in a cohort of patients with severe Pompe disease. We identified patients from the French Pompe Registry with severe respiratory failure and permanent wheelchair use (assisted walk for a few meters was allowed) when starting ERT. Patients' medical records were collected and reviewed and respiratory and motor functions, before ERT initiation and upon last evaluation were compared. Twelve patients (7 males) were identified. Median age at symptom onset was 24years [IQR=15.5; 36.0]. At baseline ventilation was invasive in 11 patients and noninvasive in one, with a median ventilation time of 24h [IQR=21.88; 24.00] (min 20; max 24). ERT was initiated at a median age of 52.5years [IQR=35.75; 66.50]. Median treatment duration was 55months [IQR=39.5; 81.0]. During observational period no adverse reaction to ERT was recorded, five patients (41.67%) died, three decreased their ventilation time by 30, 60 and 90min and two increased their assisted walking distance, by 80 and 20m. Some patients at a very advanced stage of Pompe disease may show a mild benefit from ERT, in terms of increased time of autonomous ventilation and of enlarged distance in assisted walk. ERT can be initiated in these patients in order to retain their current level of independence and ability to perform daily life activities. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Factors associated with the frequency of monitoring of liver enzymes, renal function and lipid laboratory markers among individuals initiating combination antiretroviral therapy: a cohort study.

    PubMed

    Gillis, Jennifer; Bayoumi, Ahmed M; Burchell, Ann N; Cooper, Curtis; Klein, Marina B; Loutfy, Mona; Machouf, Nima; Montaner, Julio Sg; Tsoukas, Chris; Hogg, Robert S; Raboud, Janet

    2015-10-26

    As the average age of the HIV-positive population increases, there is increasing need to monitor patients for the development of comorbidities as well as for drug toxicities. We examined factors associated with the frequency of measurement of liver enzymes, renal function tests, and lipid levels among participants of the Canadian Observational Cohort (CANOC) collaboration which follows people who initiated HIV antiretroviral therapy in 2000 or later. We used zero-inflated negative binomial regression models to examine the associations of demographic and clinical characteristics with the rates of measurement during follow-up. Generalized estimating equations with a logit link were used to examine factors associated with gaps of 12 months or more between measurements. Electronic laboratory data were available for 3940 of 7718 CANOC participants. The median duration of electronic follow-up was 3.5 years. The median (interquartile) rates of tests per year were 2.76 (1.60, 3.73), 2.55 (1.44, 3.38) and 1.42 (0.50, 2.52) for liver, renal and lipid parameters, respectively. In multivariable zero-inflated negative binomial regression models, individuals infected through injection drug use (IDU) were significantly less likely to have any measurements. Among participants with at least one measurement, rates of measurement of liver, renal and lipid tests were significantly lower for younger individuals and Aboriginal Peoples. Hepatitis C co-infected individuals with a history of IDU had lower rates of measurement and were at greater risk of having 12 month gaps between measurements. Hepatitis C co-infected participants infected through IDU were at increased risk of gaps in testing, despite publicly funded health care and increased risk of comorbid conditions. This should be taken into consideration in analyses examining factors associated with outcomes based on laboratory parameters.

  18. A retrospective analysis of the potential impact of IgG antibodies to agalsidase beta on efficacy during enzyme replacement therapy for Fabry disease.

    PubMed

    Bénichou, Bernard; Goyal, Sunita; Sung, Crystal; Norfleet, Andrea M; O'Brien, Fanny

    2009-01-01

    Fabry disease results from a genetic deficiency of alpha-galactosidase A (alpha GAL) and the impaired catabolism of globotriasoylceramide (GL-3) and other glycosphingolipid substrates, which then accumulate pathogenically within most cells. Enzyme replacement therapy (ERT) with agalsidase beta (Fabrazyme), one of two available forms of recombinant human alpha GAL, involves regular intravenous infusions of the therapeutic protein. Immunoglobulin G (IgG) antibodies to recombinant alpha GAL develop in the majority of patients upon repeated infusion. To explore whether anti-alpha GAL IgG interferes with therapeutic efficacy, retrospective analyses were conducted using data obtained from a total of 134 adult male and female patients with Fabry disease who were treated with agalsidase beta at 1mg/kg every 2 weeks for up to 5 years during placebo-controlled trials and the corresponding open-label extension studies. The analyses did not reveal a correlation between anti-alpha GAL IgG titers and the onset of clinical events or the rate of change in estimated GFR during treatment, and no statistically significant association was found between anti-alpha GAL IgG titers and abnormal elevations in plasma GL-3 during treatment. However, a statistically significant association was found between anti-alpha GAL IgG titers and observation of some GL-3 deposition in the dermal capillary endothelial cells of skin during treatment, suggesting that GL-3 clearance may be partially impaired in some patients with high antibody titers. Determination of the long-term impact of circulating anti-alpha GAL IgG antibodies on clinical outcomes will require continued monitoring, and serology testing is recommended as part of the routine care of Fabry disease patients during ERT.

  19. Effect of enzyme therapy and prognostic factors in 69 adults with Pompe disease: an open-label single-center study

    PubMed Central

    2012-01-01

    Background Enzyme replacement therapy (ERT) in adults with Pompe disease, a progressive neuromuscular disorder, is of promising but variable efficacy. We investigated whether it alters the course of disease, and also identified potential prognostic factors. Methods Patients in this open-label single-center study were treated biweekly with 20 mg/kg alglucosidase alfa. Muscle strength, muscle function, and pulmonary function were assessed every 3–6 months and analyzed using repeated-measures ANOVA. Results Sixty-nine patients (median age 52.1 years) were followed for a median of 23 months. Muscle strength increased after start of ERT (manual muscle testing 1.4 percentage points per year (pp/y); hand-held dynamometry 4.0 pp/y; both p < 0.001). Forced vital capacity (FVC) remained stable when measured in upright, but declined in supine position (−1.1 pp/y; p = 0.03). Muscle function did not improve in all patients (quick motor function test 0.7 pp/y; p = 0.14), but increased significantly in wheelchair-independent patients and those with mild and moderate muscle weakness. Relative to the pre-treatment period (49 patients with 14 months pre-ERT and 22 months ERT median follow-up), ERT affected muscle strength positively (manual muscle testing +3.3 pp/y, p < 0.001 and hand-held dynamometry +7.9 pp/y, p < 0.001). Its effect on upright FVC was +1.8 pp/y (p = 0.08) and on supine FVC +0.8 (p = 0.38). Favorable prognostic factors were female gender for muscle strength, and younger age and better clinical status for supine FVC. Conclusions We conclude that ERT positively alters the natural course of Pompe disease in adult patients; muscle strength increased and upright FVC stabilized. Functional outcome is probably best when ERT intervention is timely. PMID:23013746

  20. Transformation in pretreatment manifestations of Gaucher disease type 1 during two decades of alglucerase/imiglucerase enzyme replacement therapy in the International Collaborative Gaucher Group (ICGG) Gaucher Registry

    PubMed Central

    Batista, Julie L.; Andersson, Hans C.; Balwani, Manisha; Burrow, Thomas Andrew; Charrow, Joel; Kaplan, Paige; Khan, Aneal; Kishnani, Priya S.; Kolodny, Edwin H.; Rosenbloom, Barry; Scott, C. Ronald; Weinreb, Neal

    2017-01-01

    Abstract This study tests the hypothesis that the prevalence of severe clinical manifestations in Gaucher disease type 1 (GD1) patients at the time of treatment initiation has changed since alglucerase/imiglucerase enzyme replacement therapy (ERT) was approved in the United States (US) in 1991. US alglucerase/imiglucerase‐treated GD1 patients from the International Collaborative Gaucher Group Gaucher Registry clinicaltrials.gov NCT00358943 were stratified by age at ERT initiation (<18, 18 to <50, ≥50 years), era of ERT initiation (1991‐1995, 1996‐2000, 2001‐2005, 2006‐2009), and splenectomy status pre‐ERT. Prevalence of splenectomy decreased dramatically across the eras among all age groups. Bone manifestations were more prevalent in splenectomized patients than non‐splenectomized patients in all age groups. Prevalence of bone manifestations differed across eras in certain age groups: non‐splenectomized patients had a lower prevalence of ischemic bone events (pediatric patients) and bone crisis (pediatric patients and adults 18 to <50 years) in later eras; splenectomized adult (18 to <50 years) patients had a lower prevalence of ischemic bone events and bone crisis in later eras. Over two decades after the introduction of ERT, the prevalence of splenectomy and associated skeletal complications has declined dramatically. Concomitantly, the interval between diagnosis and initiation of ERT has decreased, most strikingly in pediatric patients who have the most severe disease. Together, these findings suggest that since the introduction of alglucerase/imiglucerase ERT, optimal standard of care has become established in the US to prevent destructive complications of GD1. PMID:28569047

  1. Oral pharmacological chaperone migalastat compared with enzyme replacement therapy in Fabry disease: 18-month results from the randomised phase III ATTRACT study.

    PubMed

    Hughes, Derralynn A; Nicholls, Kathleen; Shankar, Suma P; Sunder-Plassmann, Gere; Koeller, David; Nedd, Khan; Vockley, Gerard; Hamazaki, Takashi; Lachmann, Robin; Ohashi, Toya; Olivotto, Iacopo; Sakai, Norio; Deegan, Patrick; Dimmock, David; Eyskens, François; Germain, Dominique P; Goker-Alpan, Ozlem; Hachulla, Eric; Jovanovic, Ana; Lourenco, Charles M; Narita, Ichiei; Thomas, Mark; Wilcox, William R; Bichet, Daniel G; Schiffmann, Raphael; Ludington, Elizabeth; Viereck, Christopher; Kirk, John; Yu, Julie; Johnson, Franklin; Boudes, Pol; Benjamin, Elfrida R; Lockhart, David J; Barlow, Carrolee; Skuban, Nina; Castelli, Jeffrey P; Barth, Jay; Feldt-Rasmussen, Ulla

    2017-04-01

    Fabry disease is an X-linked lysosomal storage disorder caused by GLA mutations, resulting in α-galactosidase (α-Gal) deficiency and accumulation of lysosomal substrates. Migalastat, an oral pharmacological chaperone being developed as an alternative to intravenous enzyme replacement therapy (ERT), stabilises specific mutant ( amenable ) forms of α-Gal to facilitate normal lysosomal trafficking. The main objective of the 18-month, randomised, active-controlled ATTRACT study was to assess the effects of migalastat on renal function in patients with Fabry disease previously treated with ERT. Effects on heart, disease substrate, patient-reported outcomes (PROs) and safety were also assessed. Fifty-seven adults (56% female) receiving ERT (88% had multiorgan disease) were randomised (1.5:1), based on a preliminary cell-based assay of responsiveness to migalastat, to receive 18 months open-label migalastat or remain on ERT. Four patients had non-amenable mutant forms of α-Gal based on the validated cell-based assay conducted after treatment initiation and were excluded from primary efficacy analyses only. Migalastat and ERT had similar effects on renal function. Left ventricular mass index decreased significantly with migalastat treatment (-6.6 g/m 2 (-11.0 to -2.2)); there was no significant change with ERT. Predefined renal, cardiac or cerebrovascular events occurred in 29% and 44% of patients in the migalastat and ERT groups, respectively. Plasma globotriaosylsphingosine remained low and stable following the switch from ERT to migalastat. PROs were comparable between groups. Migalastat was generally safe and well tolerated. Migalastat offers promise as a first-in-class oral monotherapy alternative treatment to intravenous ERT for patients with Fabry disease and amenable mutations. NCT00925301; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Enzyme replacement therapy for mucopolysaccharidosis VI: Growth and pubertal development in patients treated with recombinant human N-acetylgalactosamine 4-sulfatase

    PubMed Central

    Decker, Celeste; Yu, Zi-Fan; Giugliani, Roberto; Schwartz, Ida Vanessa D.; Guffon, Nathalie; Teles, Elisa Leão; Miranda, M. Clara Sá; Wraith, J. Edmond; Beck, Michael; Arash, Laila; Scarpa, Maurizio; Ketteridge, David; Hopwood, John J.; Plecko, Barbara; Steiner, Robert; Whitley, Chester B.; Kaplan, Paige; Swiedler, Stuart J.; Conrad, Susan; Harmatz, Paul

    2010-01-01

    Background and Methods Growth failure is characteristic of untreated mucopolysaccharidosis type VI (MPS VI: Maroteaux-Lamy syndrome). Growth was studied in fifty-six MPS VI patients (5 to 29 years old) prior to and for up to 240 weeks of weekly infusions of recombinant human arylsulfatase B (rhASB) at 1 mg/kg during Phase 1/2, Phase 2, Phase 3 or Phase 3 Extension clinical trials. Height, weight, and Tanner stage data were collected. Pooled data were analyzed to determine mean height increase by treatment week, growth impacts of pubertal status, baseline urinary GAG, and age at treatment initiation. Growth rate for approximately 2 years prior to and following treatment initiation was analyzed using longitudinal modeling. Results Mean height increased by 2.9 cm after 48 weeks and 4.3 cm after 96 weeks on enzyme replacement therapy (ERT). Growth on ERT was not correlated with baseline urinary GAG. Patients under 16 years of age showed greatest increases in height on treatment. Model results based on pooled data showed significant improvement in growth rate during 96 weeks of ERT when compared to the equivalent pretreatment time period. Delayed pubertal onset or progression was noted in 10 patients entering the clinical trials; all of whom showed progression of at least one Tanner stage during 2 years on ERT, and 6 of whom (60%) completed puberty. Conclusion Analysis of mean height by treatment week and longitudinal modeling demonstrate significant increase in height and growth rate in MPS VI patients receiving long-term ERT. This impact was greatest in patients aged below 16 years. Height increase may result from bone growth and/or reduction in joint contractures. Bone growth and resolution of delayed puberty may be related to improvements in general health, bone cell health, nutrition, endocrine gland function and reduced inflammation. PMID:20634905

  3. Facial-muscle weakness, speech disorders and dysphagia are common in patients with classic infantile Pompe disease treated with enzyme therapy.

    PubMed

    van Gelder, C M; van Capelle, C I; Ebbink, B J; Moor-van Nugteren, I; van den Hout, J M P; Hakkesteegt, M M; van Doorn, P A; de Coo, I F M; Reuser, A J J; de Gier, H H W; van der Ploeg, A T

    2012-05-01

    Classic infantile Pompe disease is an inherited generalized glycogen storage disorder caused by deficiency of lysosomal acid α-glucosidase. If left untreated, patients die before one year of age. Although enzyme-replacement therapy (ERT) has significantly prolonged lifespan, it has also revealed new aspects of the disease. For up to 11 years, we investigated the frequency and consequences of facial-muscle weakness, speech disorders and dysphagia in long-term survivors. Sequential photographs were used to determine the timing and severity of facial-muscle weakness. Using standardized articulation tests and fibreoptic endoscopic evaluation of swallowing, we investigated speech and swallowing function in a subset of patients. This study included 11 patients with classic infantile Pompe disease. Median age at the start of ERT was 2.4 months (range 0.1-8.3 months), and median age at the end of the study was 4.3 years (range 7.7 months -12.2 years). All patients developed facial-muscle weakness before the age of 15 months. Speech was studied in four patients. Articulation was disordered, with hypernasal resonance and reduced speech intelligibility in all four. Swallowing function was studied in six patients, the most important findings being ineffective swallowing with residues of food (5/6), penetration or aspiration (3/6), and reduced pharyngeal and/or laryngeal sensibility (2/6). We conclude that facial-muscle weakness, speech disorders and dysphagia are common in long-term survivors receiving ERT for classic infantile Pompe disease. To improve speech and reduce the risk for aspiration, early treatment by a speech therapist and regular swallowing assessments are recommended.

  4. Long-term velaglucerase alfa treatment in children with Gaucher disease type 1 naïve to enzyme replacement therapy or previously treated with imiglucerase.

    PubMed

    Smith, Laurie; Rhead, William; Charrow, Joel; Shankar, Suma P; Bavdekar, Ashish; Longo, Nicola; Mardach, Rebecca; Harmatz, Paul; Hangartner, Thomas; Lee, Hak-Myung; Crombez, Eric; Pastores, Gregory M

    2016-02-01

    Gaucher Disease type 1 (GD1) often manifests in childhood. Early treatment with enzyme replacement therapy (ERT) may prevent disease complications. We report the assessment of velaglucerase alfa ERT in pediatric GD1 patients who participated in a long-term extension study (HGT-GCB-044, ClinicalTrials.gov Identifier NCT00635427). Safety and efficacy were evaluated in pediatric patients receiving velaglucerase alfa 30-60U/kg by intravenous infusion every other week. In addition to key hematological and visceral efficacy assessments, exploratory assessments conducted specifically in pediatric patients included evaluation of height, bone age, bone marrow burden, and Tanner stage of puberty. The study included 24 pediatric patients. Fifteen patients were naïve to ERT on entry into the preceding trials TKT032 (12-month trial) or HGT-GCB-039 (9-month trial): in the preceding trials, ten of these 15 patients received velaglucerase alfa and five patients received imiglucerase ERT. Nine patients in the study were previously treated with imiglucerase for >30months and were switched to velaglucerase alfa in the preceding trial TKT034 (12-month trial). Cumulative ERT exposure in the clinical studies ranged from 2.0 to 5.8years. Three serious adverse events, including a fatal convulsion, were reported; none were deemed related to velaglucerase alfa. One patient tested positive for anti-velaglucerase alfa antibodies. An efficacy assessment at 24months showed that velaglucerase alfa had positive effects on primary hematological and visceral parameters in treatment-naïve patients, which were maintained with longer-term treatment. Disease parameters were stable in patients switched from long-term imiglucerase ERT. Exploratory results may suggest benefits of early treatment to enable normal growth in pediatric patients. The safety profile and clinical response seen in pediatric patients are consistent with results reported in adults. Copyright © 2016 Shire Development LLC

  5. Efficacy and safety of enzyme-replacement-therapy with agalsidase alfa in 36 treatment-naïve Fabry disease patients.

    PubMed

    Tsuboi, Kazuya; Yamamoto, Hiroshi

    2017-06-07

    Fabry disease (FD) is an X-linked lysosomal storage disorder resulting from the α-galactosidase A gene mutations. Enzyme-replacement-therapy (ERT) products for FD currently used include agalsidase alfa and agalsidase beta. There are many reports on efficacy and safety of ERT. However, most of the previous studies are done as a retrospective medical records analysis. The Japan Fabry Research - 002 (JFR-002) was a prospective observational clinical study of 36 ERT-naïve FD patients (14 men and 22 women) at baseline (BL) and after initiation of ERT with agalsidase alfa 0.2 mg/kg every two weeks, a median period 62.5 months. The parameters measured included globotriaosylceramide (Gb3), globotriaosylsphingosine (Lyso-Gb3), left ventricular mass index (LVMI), brain natriuretic peptide (BNP), high-sensitivity troponin I (hs-Trop I), estimated glomerular filtration rate (eGFR), and anti-agalsidase alfa IgG antibody formation. All parameters remained steady during ERT treatment period. BNP levels in 14 patients whose BL levels were within the normal range (<19.5 pg/mL) remained within the same range, while 22 patients whose BL levels were abnormally high (≥19.5 pg/mL) gradually showed decreased levels after start of ERT. Gb3 and Lyso-Gb3 levels remarkably decreased after the initiation of ERT and remained low. The JFR-002 suggests that agalsidase alfa is effective in maintaining organ function in FD patients, and that the incidence of infusion reactions related to the treatment with agalsidase alfa is low, indicating the good tolerability to this ERT. The JFR-002 was retrospectively registered at Japan Medical Association Center for Clinical Trials (Registration number: JMA-IIA00291 ) on May 19th, 2017.

  6. Pharmacokinetics and Toxicology of a Fibroblast Activation Protein (FAP)-activated Prodrug in Murine Xenograft Models of Human Cancer

    PubMed Central

    Brennen, W. Nathaniel; Rosen, D. Marc; Chaux, Alcides; Netto, George J.; Isaacs, John T.; Denmeade, Samuel R.

    2014-01-01

    Background As carcinoma progresses, the stroma undergoes a variety of phenotypic changes, including the presence of carcinoma-associated fibroblasts (CAFs) that express fibroblast activation protein (FAP). FAP is a post-prolyl endopeptidase whose expression in a healthy adult is largely restricted to the cancer-associated stroma. FAP-targeted prodrugs with a 100-fold greater therapeutic window over the parent compound were previously generated. Methods Prodrugs and non-cleavable controls were incubated in the presence of FAP. Plasma and tumor half-lives (t1/2) of the full-length and active forms of the prodrugs were determined using LCMS. Biodistribution studies of prodrug activation were performed. Histopathological analysis of tissues from treated animals were compared to vehicle-treated controls. Toxicity and efficacy studies were performed in human breast (MDA-MB-231 and MCF-7) and prostate (LNCaP) cancer xenografts models. Results These FAP-activated prodrugs have a significantly slower clearance from tumor tissue than the circulation (~12 vs. ~4.5 hrs). Micromolar concentrations of active drug persist in the tumor. Active drug is detected in non-target tissues; however, histopathologic evaluation reveals no evidence of drug-induced toxicity. A FAP-activated prodrug (ERGETGP-S12ADT) inhibits tumor growth in multiple human breast and prostate cancer xenograft models. The anti-tumor effect is comparable to that observed with docetaxel, but results in significantly less toxicity. Conclusion FAP-activated prodrugs are a viable strategy for the management of prostate and other cancers. These prodrugs exhibit less toxicity than a commonly used chemotherapeutic agent. Further refinement of the FAP cleavage site for greater specificity may reduce prodrug activation in non-target tissues and enhance clinical benefit. PMID:25053236

  7. Pharmacokinetics and toxicology of a fibroblast activation protein (FAP)-activated prodrug in murine xenograft models of human cancer.

    PubMed

    Brennen, W Nathaniel; Rosen, D Marc; Chaux, Alcides; Netto, George J; Isaacs, John T; Denmeade, Samuel R

    2014-09-01

    As carcinoma progresses, the stroma undergoes a variety of phenotypic changes, including the presence of carcinoma-associated fibroblasts (CAFs) that express fibroblast activation protein (FAP). FAP is a post-prolyl endopeptidase whose expression in a healthy adult is largely restricted to the cancer-associated stroma. FAP-targeted prodrugs with a 100-fold greater therapeutic window over the parent compound were previously generated. Prodrugs and non-cleavable controls were incubated in the presence of FAP. Plasma and tumor half-lives (t1/2) of the full-length and active forms of the prodrugs were determined using LCMS. Biodistribution studies of prodrug activation were performed. Histopathological analysis of tissues from treated animals were compared to vehicle-treated controls. Toxicity and efficacy studies were performed in human breast (MDA-MB-231 and MCF-7) and prostate (LNCaP) cancer xenografts models. These FAP-activated prodrugs have a significantly slower clearance from tumor tissue than the circulation (∼12 vs. ∼4.5 hr). Micromolar concentrations of active drug persist in the tumor. Active drug is detected in non-target tissues; however, histopathologic evaluation reveals no evidence of drug-induced toxicity. A FAP-activated prodrug (ERGETGP-S12ADT) inhibits tumor growth in multiple human breast and prostate cancer xenograft models. The anti-tumor effect is comparable to that observed with docetaxel, but results in significantly less toxicity. FAP-activated prodrugs are a viable strategy for the management of prostate and other cancers. These prodrugs exhibit less toxicity than a commonly used chemotherapeutic agent. Further refinement of the FAP cleavage site for greater specificity may reduce prodrug activation in non-target tissues and enhance clinical benefit. © 2014 Wiley Periodicals, Inc.

  8. Prodrugs of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), More Than Meets the Eye: A Critical Review

    PubMed Central

    Qandil, Amjad M.

    2012-01-01

    The design and the synthesis of prodrugs for nonsteroidal anti-inflammatory drugs (NSAIDs) have been given much attention by medicinal chemists, especially in the last decade. As a therapeutic group, NSAIDs are among the most widely used prescribed and over the counter (OTC) medications. The rich literature about potential NSAID prodrugs clearly shows a shift from alkyl, aryalkyl or aryl esters with the sole role of masking the carboxylic acid group, to more elaborate conjugates that contain carefully chosen groups to serve specific purposes, such as enhancement of water solubility and dissolution, nitric oxide release, hydrogen sulfide release, antioxidant activity, anticholinergic and acetylcholinesterase inhibitory (AChEI) activity and site-specific targeting and delivery. This review will focus on NSAID prodrugs that have been designed or were, later, found to possess intrinsic pharmacological activity as an intact chemical entity. Such intrinsic activity might augment the anti-inflammatory activity of the NSAID, reduce its side effects or transform the potential therapeutic use from classical anti-inflammatory action to something else. Reports discussed in this review will be those of NO-NSAIDs, anticholinergic and AChEI-NSAIDs, Phospho-NSAIDs and some miscellaneous agents. In most cases, this review will cover literature dealing with these NSAID prodrugs from the year 2006 and later. Older literature will be used when necessary, e.g., to explain the chemical and biological mechanisms of action. PMID:23247285

  9. Prodrug and nanomedicine approaches for the delivery of the camptothecin analogue SN38.

    PubMed

    Bala, Vaskor; Rao, Shasha; Boyd, Ben J; Prestidge, Clive A

    2013-11-28

    SN38 (7-ethyl-10-hydroxy camptothecin) is a prominent and efficacious anticancer agent. It is poorly soluble in both water and pharmaceutically approved solvents; therefore, the direct formulation of SN38 in solution form is limited. Currently, the water soluble prodrug of SN38, irinotecan (CPT-11), is formulated as a low pH solution and is approved for chemotherapy. However, CPT-11, along with most other water-soluble prodrugs shows unpredictable inter-patient conversion to SN38 in vivo, instability in the physiological environment and variable dose-related toxicities. More recently, macromolecular prodrugs (i.e. EZN-2208, IMMU-130) and nanomedicine formulations (i.e. nanoemulsions, polymeric micelles, lipid nanocapsule/nanoparticle, and liposomes) of SN38 have been investigated for improved delivery to cancer cells and tissues. Specifically, these carriers can take advantage of the EPR effect to direct drug preferentially to tumour tissues, thereby substantially improving efficacy and minimising side effects. Furthermore, oral delivery has been shown to be possible in preclinical results using nanomedicine formulations (i.e. dendrimers, lipid nanocapsules, polymeric micelles). This review summarizes the recent advances for the delivery of SN38 with a focus on macromolecular prodrugs and nanomedicines. © 2013 Elsevier B.V. All rights reserved.

  10. An acetate prodrug of a pyridinol-based vitamin E analogue.

    PubMed

    Khdour, Omar M; Lu, Jun; Hecht, Sidney M

    2011-11-01

    To investigate of an approach to stabilize a novel pyridinol based α-tocopherol analogue (1) as a prodrug by acetylation of its phenol moiety. Biochemical indicators of oxidative stress in mitochondria were utilized to gain insight into the cytoprotective mechanism(s) of compound 1 acetate. Oxygen free radical scavenging activity was measured using DCF probe in a cultured cell model system that had been placed under oxidative stress. Lipid peroxidation was examined both in a cell-free system and in oxidatively stressed cultured cells. The bioenergetic parameters of mitochondria were evaluated by measuring mitochondrial membrane potential (Δψ(m)) and the MPT. The present results suggest strongly that the antioxidant efficacy of compound 1 can be improved by using it as a prodrug. The tested prodrug has shown to be activated as a function of time, presumably due to susceptibility to enzymatic hydrolysis, and exhibits an antioxidant effect in time-dependent manner, providing a compound that is more effective than α-tocopherol acetate with regard to all protective properties studied. An effective approach to stabilize compound 1 was realized by using its acetate as a prodrug.

  11. Comparative pharmacokinetics of two prodrugs of zidovudine in rabbits: enhanced levels of zidovudine in brain tissue.

    PubMed

    Lupia, R H; Ferencz, N; Lertora, J J; Aggarwal, S K; George, W J; Agrawal, K C

    1993-04-01

    The pharmacokinetics of two prodrugs of zidovudine (AZT), 1,4-dihydro-1-methyl-3-[(pyridylcarbonyl)oxy] ester and isoleucinyl ester (DPAZT and IAZT, respectively), were investigated in a rabbit model to determine their potential utility as drugs against human immunodeficiency virus. Drugs were administered by intravenous infusion over 5 min at doses equal to 10 mg of AZT per kg of body weight. The levels of the prodrugs and of released AZT in plasma, cerebrospinal fluid (CSF), and brain were determined by high-performance liquid chromatography analysis. DPAZT disappeared rapidly from plasma, whereas IAZT maintained a sustained level in plasma for up to 4 h. The levels in plasma of AZT released from DPAZT were consistently lower than the levels of AZT released from IAZT or AZT itself. At 75 min after infusion of AZT, DPAZT, and IAZT, the CSF plasma AZT ratios were 0.23, 0.30, and 0.25, while the brain/CSF AZT ratios were 0.32, 0.63, and 0.64, respectively. These results indicate that the administration of each of the prodrugs produced a higher concentration of AZT in the brain than did the direct administration of AZT. Both prodrugs therefore may be superior to AZT itself with respect to achieving anti-human immunodeficiency virus concentrations within the central nervous system.

  12. Comparative pharmacokinetics of two prodrugs of zidovudine in rabbits: enhanced levels of zidovudine in brain tissue.

    PubMed Central

    Lupia, R H; Ferencz, N; Lertora, J J; Aggarwal, S K; George, W J; Agrawal, K C

    1993-01-01

    The pharmacokinetics of two prodrugs of zidovudine (AZT), 1,4-dihydro-1-methyl-3-[(pyridylcarbonyl)oxy] ester and isoleucinyl ester (DPAZT and IAZT, respectively), were investigated in a rabbit model to determine their potential utility as drugs against human immunodeficiency virus. Drugs were administered by intravenous infusion over 5 min at doses equal to 10 mg of AZT per kg of body weight. The levels of the prodrugs and of released AZT in plasma, cerebrospinal fluid (CSF), and brain were determined by high-performance liquid chromatography analysis. DPAZT disappeared rapidly from plasma, whereas IAZT maintained a sustained level in plasma for up to 4 h. The levels in plasma of AZT released from DPAZT were consistently lower than the levels of AZT released from IAZT or AZT itself. At 75 min after infusion of AZT, DPAZT, and IAZT, the CSF plasma AZT ratios were 0.23, 0.30, and 0.25, while the brain/CSF AZT ratios were 0.32, 0.63, and 0.64, respectively. These results indicate that the administration of each of the prodrugs produced a higher concentration of AZT in the brain than did the direct administration of AZT. Both prodrugs therefore may be superior to AZT itself with respect to achieving anti-human immunodeficiency virus concentrations within the central nervous system. PMID:8494380

  13. Alkoxycarbonate Ester Prodrugs of Preclinical Drug Candidate ELQ-300 for Prophylaxis and Treatment of Malaria.

    PubMed

    Frueh, Lisa; Li, Yuexin; Mather, Michael W; Li, Qigui; Pou, Sovitj; Nilsen, Aaron; Winter, Rolf W; Forquer, Isaac P; Pershing, April M; Xie, Lisa H; Smilkstein, Martin J; Caridha, Diana; Koop, Dennis R; Campbell, Robert F; Sciotti, Richard J; Kreishman-Deitrick, Mara; Kelly, Jane X; Vesely, Brian; Vaidya, Akhil B; Riscoe, Michael K

    2017-10-13

    ELQ-300 is a preclinical antimalarial drug candidate that is active against liver, blood, and transmission stages of Plasmodium falciparum. While ELQ-300 is highly effective when administered in a low multidose regimen, poor aqueous solubility and high crystallinity have hindered its clinical development. To overcome its challenging physiochemical properties, a number of bioreversible alkoxycarbonate ester prodrugs of ELQ-300 were synthesized. These bioreversible prodrugs are converted to ELQ-300 by host and parasite esterase action in the liver and bloodstream of the host. One such alkoxycarbonate prodrug, ELQ-331, is curative against Plasmodium yoelii with a single low dose of 3 mg/kg in a murine model of patent malaria infection. ELQ-331 is at least as fully protective as ELQ-300 in a murine malaria prophylaxis model when delivered 24 h before sporozoite inoculation at an oral dose of 1 mg/kg. Here, we show that ELQ-331 is a promising prodrug of ELQ-300 with improved physiochemical and metabolic properties and excellent potential for clinical formulation.

  14. Prodrug and covalent linker strategies for the solubilization of dual-action antioxidants/iron chelators.

    PubMed

    Bebbington, David; Dawson, Claire E; Gaur, Suneel; Spencer, John

    2002-11-18

    Water soluble prodrugs of hybrid free radical scavenger/iron chelating molecules, based on 3,5-disubstituted-4-hydroxyphenyl derivatives and 3-hydroxy-2-methyl-4(1H)-pyridinone (deferiprone), have been prepared. Related hybrid molecules containing a covalent poly(ethylene)glycol or an amine linker were also synthesized.

  15. Rational design of a dual-mode optical and chemical prodrug.

    PubMed

    McCoy, Colin P; Rooney, Clare; Jones, David S; Gorman, Sean P; Nieuwenhuyzen, Mark

    2007-01-01

    The purpose of this study is to demonstrate the rational design and behaviour of the first dual-mode optical and chemical prodrug, exemplified by an acetyl salicylic acid-based system. A cyclic 1,4-benzodioxinone prodrug was synthesised by reaction of 3,5-dimethoxybenzoin and acetyl salicoyl chloride with pyridine. After purification by column chromatography and recrystallization, characterization was achieved using infrared and NMR spectroscopies, mass spectrometry, elemental analysis and single crystal X-ray diffraction. Light-triggered drug liberation was characterised via UV-visible spectroscopy following low-power 365 nm irradiation for controlled times. Chemical drug liberation was characterised via UV-visible spectroscopy in pH 5.5 solution. The synthetic method yielded pure prodrug, with full supporting characterisation. Light-triggered drug liberation proceeded at a rate of 8.30x10(-2) s-1, while chemical, hydrolytic liberation proceeded independently at 1.89x10(-3) s-1. The photochemical and hydrolytic reactions were both quantitative. This study demonstrates the first rational dual-mode optical and chemical prodrug, using acetyl salicylic acid as a model, acting as a paradigm for future dual-mode systems. Photochemical drug liberation proceeds 44 times faster than chemical liberation, suggesting potential use in drug-eluting medical devices where an additional burst of drug is required at the onset of infection.

  16. Antimycobacterial activity of pyrazinoate prodrugs in replicating and non-replicating Mycobacterium tuberculosis.

    PubMed

    Segretti, Natanael Dante; Simões, Cristina Kortstee; Corrêa, Michelle Fidelis; Felli, Veni Maria Andres; Miyata, Marcelo; Cho, Sang Hyun; Franzblau, Scott Gary; Fernandes, João Paulo Dos Santos

    2016-07-01

    Tuberculosis (TB) is an important infectious disease caused by Mycobacterium tuberculosis (Mtb) and responsible for thousands of deaths every year. Although there are antimycobacterial drugs available in therapeutics, just few new chemical entities have reached clinical trials, and in fact, since introduction of rifampin only two important drugs had reached the market. Pyrazinoic acid (POA), the active agent of pyrazinamide, has been explored through prodrug approach to achieve novel molecules with anti-Mtb activity, however, there is no activity evaluation of these molecules against non-replicating Mtb until the present. Additionally, pharmacokinetic must be preliminary evaluated to avoid future problems during clinical trials. In this paper, we have presented six POA esters as prodrugs in order to evaluate their anti-Mtb activity in replicating and non-replicating Mtb, and these showed activity highly influenced by medium composition (especially by albumin). Lipophilicity seems to play the main role in the activity, possibly due to controlling membrane passage. Novel duplicated prodrugs of POA were also described, presenting interesting activity. Cytotoxicity of these prodrugs set was also evaluated, and these showed no important cytotoxic profile. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Enhanced Cellular Uptake and Pharmacokinetic Characteristics of Doxorubicin-Valine Amide Prodrug.

    PubMed

    Park, Yohan; Park, Ju-Hwan; Park, Suryeon; Lee, Song Yi; Cho, Kwan Hyung; Kim, Dae-Duk; Shim, Won-Sik; Yoon, In-Soo; Cho, Hyun-Jong; Maeng, Han-Joo

    2016-09-22

    In this study, we synthesized the valine (Val)-conjugated amide prodrug of doxorubicin (DOX) by the formation of amide bonds between DOX and Val. The synthesis of the DOX-Val prodrug was identified by a proton nuclear magnetic resonance (¹H-NMR) assay. In the MCF-7 cells (human breast adenocarcinoma cell; amino acid transporter-positive cell), the cellular accumulation efficiency of DOX-Val was higher than that of DOX according to the flow cytometry analysis data. Using confocal laser scanning microscopy (CLSM) imaging, it was confirmed that DOX-Val as well as DOX was mainly distributed in the nucleus of cancer cells. DOX-Val was intravenously administered to rats at a dose of 4 mg/kg, and the plasma concentrations of DOX-Val (prodrug) and DOX (formed metabolite) were quantitatively determined. Based on the systemic exposure (represented as area under the curve (AUC) values) of DOX-Val (prodrug) and DOX (formed metabolite), approximately half of DOX-Val seemed to be metabolized into DOX. However, it is expected that the remaining DOX-Val may exert improved cellular uptake efficiency in cancer cells after its delivery to the cancer region.

  18. "Project ALERT's" Effects on Adolescents' Prodrug Beliefs: A Replication and Extension Study

    ERIC Educational Resources Information Center

    Clark, Heddy Kovach; Ringwalt, Chris L.; Hanley, Sean; Shamblen, Stephen R.

    2010-01-01

    This article represents a replication and extension of previous studies of the effects of "Project ALERT", a school-based substance use prevention program, on the prodrug beliefs of adolescents. Specifically, the authors' research examined "Project ALERT's" effects on adolescents' intentions to use substances in the future, beliefs about substance…

  19. Alkylation of 6-mercaptopurine (6-MP) with N-alkyl-N-alkoxycarbonylaminomethyl chlorides: S6-(N-alkyl-N-alkoxycarbonyl)aminomethyl-6-MP prodrug structure effect on the dermal delivery of 6-MP.

    PubMed

    Siver, K G; Sloan, K B

    1990-01-01

    The S6-(N-alkyl-N-alkoxycarbonyl)aminomethyl-6-MP (6-CARB-6-MP) prodrugs 5-20 were synthesized from the reaction of 6-MP with N-alkyl-N-alkyoxycarbonylaminomethyl chlorides (4) in dimethyl sulfoxide in overall yields of 5-62%, depending on the N-alkyl and the alkoxy groups involved. The derivatives were fully characterized by spectral and microanalyses. The assignment of the substitution pattern as S6-alkyl was based on comparisons of the UV, 1H NMR and 13C NMR spectra with model compounds. A S6, 9-bis-alkyl derivative was obtained from the reaction of 2 equivalents of 4 with 6-MP but the product was unstable and decomposed on standing to a 9-alkyl derivative. The 6-CARB-6-MP prodrugs reverted to 6-MP in water by an SN1-type mechanism involving unimolecular charge separation in the transition state of the rate determining step. There was no effect of dermal enzymes on the rate of hydrolysis. The solubilities in isopropyl myristate (IPM) for all of the 6-CARB-6-MP prodrugs were significantly greater than the solubility of 6-MP in IPM but only one prodrug (5) was apparently even as soluble as 6-MP in water. Selected 6-CARB-6-MP prodrugs were examined in diffusion cell experiments. Only the N-methyl-N-methoxycarbonyl derivative 5 gave a steady-state rate of delivery of 6-MP from IPM that was significantly greater than the steady-state rate of delivery of 6-MP from 6-MP in IPM. All the other derivatives gave steady-state rates of delivery of 6-MP from IPM that were either not significantly different, or were significantly lower than the rate obtained from 6-MP in IPM. In all cases, the effect of the 6-CARB-6-MP:IPM suspensions on the permeability of the skin, as determined by the second application flux of theophylline:propylene glycol, was of the same magnitude as the effect of IPM alone.

  20. The nitric oxide prodrug JS-K is effective against non-small-cell lung cancer cells in vitro and in vivo: involvement of reactive oxygen species.

    PubMed

    Maciag, Anna E; Chakrapani, Harinath; Saavedra, Joseph E; Morris, Nicole L; Holland, Ryan J; Kosak, Ken M; Shami, Paul J; Anderson, Lucy M; Keefer, Larry K

    2011-02-01

    Non-small-cell lung cancer is among the most common and deadly forms of human malignancies. Early detection is unusual, and there are no curative therapies in most cases. Diazeniumdiolate-based nitric oxide (NO)-releasing prodrugs are a growing class of promising NO-based therapeutics. Here, we show that O(2)-(2,4-dinitrophenyl)-1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K) is a potent cytotoxic agent against a subset of human non-small-cell lung cancer cell lines both in vitro and as xenografts in mice. JS-K treatment led to 75% reduction in the growth of H1703 lung adenocarcinoma cells in vivo. Differences in sensitivity to JS-K in different lung cancer cell lines seem to be related to their endogenous levels of reactive oxygen species (ROS)/reactive nitrogen species (RNS). Other related factors, levels of peroxiredoxin 1 (PRX1) and 8-oxo-deoxyguanosine glycosylase (OGG1), also correlated with drug sensitivity. Treatment of the lung adenocarcinoma cells with JS-K resulted in oxidative/nitrosative stress in cells with high basal levels of ROS/RNS, which, combined with the arylating properties of the compound, was reflected in glutathione depletion and alteration in cellular redox potential, mitochondrial membrane permeabilization, and cytochrome c release. Inactivation of manganese superoxide dismutase by nitration was associated with increased superoxide and significant DNA damage. Apoptosis followed these events. Taken together, the data suggest that diazeniumdiolate-based NO-releasing prodrugs may have application as a personalized therapy for lung cancers characterized by high levels of ROS/RNS. PRX1 and OGG1 proteins, which can be easily measured, could function as biomarkers for identifying tumors sensitive to the therapy.

  1. Pharmacokinetics of Curcumin Diethyl Disuccinate, a Prodrug of Curcumin, in Wistar Rats.

    PubMed

    Bangphumi, Kunan; Kittiviriyakul, Chuleeporn; Towiwat, Pasarapa; Rojsitthisak, Pornchai; Khemawoot, Phisit

    2016-12-01

    Curcumin is the major bioactive component of turmeric, but has poor oral bioavailability that limits its clinical applications. To improve the in vitro solubility and alkaline stability, we developed a prodrug of curcumin by succinylation to obtain curcumin diethyl disuccinate, with the goal of improving the oral bioavailability of curcumin. The in vivo pharmacokinetic profile of curcumin diethyl disuccinate was compared with that of curcumin in male Wistar rats. Doses of curcumin 20 mg/kg intravenous or 40 mg/kg oral were used as standard regimens for comparison with the prodrug at equivalent doses in healthy adult rats. Blood, tissues, urine, and faeces were collected from time zero to 48 h after dosing to determine the prodrug level, curcumin level and a major metabolite by liquid chromatography-tandem spectrometry. The absolute oral bioavailability of curcumin diethyl disuccinate was not significantly improved compared with curcumin, with both compounds having oral bioavailability of curcumin less than 1 %. The major metabolic pathway of the prodrug was rapid hydrolysis to obtain curcumin, followed by glucuronidation. Interestingly, curcumin diethyl disuccinate gave superior tissue distribution with higher tissue to plasma ratio of curcumin and curcumin glucuronide in several organs after intravenous dosing at 1 and 4 h. The primary elimination route of curcumin glucuronide occurred via biliary and faecal excretion, with evidence of an entry into the enterohepatic circulation. Curcumin diethyl disuccinate did not significantly improve the oral bioavailability of curcumin due to first pass metabolism in the gastrointestinal tract. Further studies on reduction of first pass metabolism are required to optimise delivery of curcumin using a prodrug approach.

  2. Comparative plasma disposition kinetics of albendazole and its new benzimidazol prodrug in dog.

    PubMed

    Khalil, Z; El Karbane, M; Faouzi, M E A; Ansar, M; Azougagh, M; El Harti, J; Taoufik, J

    2016-01-01

    The comparative pharmacokinetic behavior of albendazole (ABZ) and its new benzimidazol prodrug [1-tert-butyloxycarbonyl-5-propylthio-1-H-benzimidazol-2ylcarbamate of methyl] (ABZBoc), following their oral administration (10mg/kg) to healthy dogs was explored. Blood samples were obtained serially over a 24h period after treatment, then the plasma was analyzed by high-performance liquid chromatography (HPLC) to search the albendazole metabolites (ABZSO and ABZSO2). However, the albendazole parent drug was not detectable at any time after both treatments (ABZ and ABZBoc). By albendazole metabolites (ABZSO and ABZSO2) were the analytes recovered in the plasma after oral administration of ABZ and ABZBoc. Furthermore, some amounts of ABZBoc were also available in the plasma samples treated with this new produg. The plasma profile of each analyte followed a similar pattern after both treatments, the active metabolite (ABZSO) was the major analyte recovered in plasma (between 1 and 24h post-treatment). The pharmacokinetic parameters of both groups were calculated (Cmax, Tmax, t1/2, AUC0-›∞), and analyzed using the Student's t-test, P<0.05. Thus,the pharmacokinetic analysis indicated four statistically significant changes in the pharmacokinetic parameters defined above of the albendazole metabolites (ABZSO, ABZSO2) between the group treated with albendazole (group A) and that treated with ABZBoc prodrug (group B). Hence, the levels of the various pharmacokinetics parameters were low in the group treated with prodrug, as well they did not reach equivalent concentrations to that of albendazole. These differences between albendazole and its new prodrug may be explained by the fact that ABZBoc prodrug was not effectively reduced in the intestine of dogs. Copyright © 2015 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.

  3. Folate Receptor-Mediated Enhanced and Specific Delivery of Far-Red Light-Activatable Prodrugs of Combretastatin A-4 to FR-Positive Tumor

    PubMed Central

    2015-01-01

    We examined the concept of a novel prodrug strategy in which anticancer drug can be locally released by visible/near IR light, taking advantage of the photodynamic process and photo-unclick chemistry. Our most recently formulated prodrug of combretastatin A-4, Pc-(L-CA4)2, showed multifunctionality for fluorescence imaging, light-activated drug release, and the combined effects of PDT and local chemotherapy. In this formulation, L is a singlet oxygen cleavable linker. Here, we advanced this multifunctional prodrug by adding a tumor-targeting group, folic acid (FA). We designed and prepared four FA-conjugated prodrugs 1–4 (CA4-L-Pc-PEGn-FA: n = 0, 2, 18, ∼45) and one non-FA-conjugated prodrug 5 (CA4-L-Pc-PEG18-boc). Prodrugs 3 and 4 had a longer PEG spacer and showed higher hydrophilicity, enhanced uptake to colon 26 cells via FR-mediated mechanisms, and more specific localization to SC colon 26 tumors in Balb/c mice than prodrugs 1 and 2. Prodrug 4 also showed higher and more specific uptake to tumors, resulting in selective tumor damage and more effective antitumor efficacy than non-FA-conjugated prodrug 5. FR-mediated targeting seemed to be an effective strategy to spare normal tissues surrounding tumors in the illuminated area during treatment with this prodrug. PMID:25351441

  4. Effects of enzyme replacement therapy for cardiac-type Fabry patients with a Chinese hotspot late-onset Fabry mutation (IVS4+919G>A)

    PubMed Central

    Lin, Hsiang-Yu; Liu, Hao-Chuan; Huang, Yu-Hsiu; Liao, Hsuan-Chieh; Hsu, Ting-Rong; Shen, Chia-I; Li, Shao-Tzu; Li, Cheng-Fang; Lee, Li-Hong; Lee, Pi-Chang; Huang, Chun-Kai; Chiang, Chuan-Chi; Lin, Ching-Yuang; Lin, Shuan-Pei; Niu, Dau-Ming

    2013-01-01

    Objective Current studies of newborn screening for Fabry disease in Taiwan have revealed a remarkably high prevalence of cardiac-type Fabry disease with a Chinese hotspot late-onset Fabry mutation (IVS4+919G>A). Design Retrospective cohort study. Setting Tertiary medical centre. Participants 21 patients with cardiac-type Fabry disease (15 men and 6 women) as well as 15 patients with classic Fabry disease (4 men and 11 women) treated with biweekly intravenous infusions of agalsidase β (1 mg/kg) or agalsidase α (0.2 mg/kg) for at least 6 months. Outcome measures These data were collected at the time before enzyme replacement therapy (ERT) began and followed up after ERT for at least 6 months, including patient demographics, medical history, parameter changes of cardiac status and renal functions, plasma globotriaosylsphingosine (lyso-Gb3) and Mainz Severity Score Index. Results After 6–39 months of ERT, plasma lyso-Gb3 was found to be reduced in 89% (17/19) and 93% (14/15) of patients with cardiac-type and classic Fabry disease, respectively, which indicated an improvement of disease severity. For patients with cardiac-type Fabry disease, echocardiography revealed the reduction or stabilisation of left ventricular mass index (LVMI), the thicknesses of intraventricular septum (IVS) and left posterior wall (LPW) in 83% (15/18), 83% (15/18) and 67% (12/18) of patients, respectively, as well as 77% (10/13), 73% (11/15) and 60% (9/15) for those with classic type. Most patients showed stable renal function after ERT. There were statistically significant improvements (p<0.05) between the data at baseline and those after ERT for values of plasma lyso-Gb3, LVMI, IVS, LPW and Mainz Severity Score Index. No severe clinical events were reported during the treatment. Conclusions ERT is beneficial and appears to be safe for Taiwanese patients with cardiac-type Fabry disease, as well as for those with the classic type. PMID:23864212

  5. Recommendations for initiation and cessation of enzyme replacement therapy in patients with Fabry disease: the European Fabry Working Group consensus document.

    PubMed

    Biegstraaten, Marieke; Arngrímsson, Reynir; Barbey, Frederic; Boks, Lut; Cecchi, Franco; Deegan, Patrick B; Feldt-Rasmussen, Ulla; Geberhiwot, Tarekegn; Germain, Dominique P; Hendriksz, Chris; Hughes, Derralynn A; Kantola, Ilkka; Karabul, Nesrin; Lavery, Christine; Linthorst, Gabor E; Mehta, Atul; van de Mheen, Erica; Oliveira, João P; Parini, Rossella; Ramaswami, Uma; Rudnicki, Michael; Serra, Andreas; Sommer, Claudia; Sunder-Plassmann, Gere; Svarstad, Einar; Sweeb, Annelies; Terryn, Wim; Tylki-Szymanska, Anna; Tøndel, Camilla; Vujkovac, Bojan; Weidemann, Frank; Wijburg, Frits A; Woolfson, Peter; Hollak, Carla E M

    2015-03-27

    Fabry disease (FD) is a lysosomal storage disorder resulting in progressive nervous system, kidney and heart disease. Enzyme replacement therapy (ERT) may halt or attenuate disease progression. Since administration is burdensome and expensive, appropriate use is mandatory. We aimed to define European consensus recommendations for the initiation and cessation of ERT in patients with FD. A Delphi procedure was conducted with an online survey (n = 28) and a meeting (n = 15). Patient organization representatives were present at the meeting to give their views. Recommendations were accepted with ≥75% agreement and no disagreement. For classically affected males, consensus was achieved that ERT is recommended as soon as there are early clinical signs of kidney, heart or brain involvement, but may be considered in patients of ≥16 years in the absence of clinical signs or symptoms of organ involvement. Classically affected females and males with non-classical FD should be treated as soon as there are early clinical signs of kidney, heart or brain involvement, while treatment may be considered in females with non-classical FD with early clinical signs that are considered to be due to FD. Consensus was achieved that treatment should not be withheld from patients with severe renal insufficiency (GFR < 45 ml/min/1.73 m(2)) and from those on dialysis or with cognitive decline, but carefully considered on an individual basis. Stopping ERT may be considered in patients with end stage FD or other co-morbidities, leading to a life expectancy of <1 year. In those with cognitive decline of any cause, or lack of response for 1 year when the sole indication for ERT is neuropathic pain, stopping ERT may be considered. Also, in patients with end stage renal disease, without an option for renal transplantation, in combination with advanced heart failure (NYHA class IV), cessation of ERT should be considered. ERT in patients who are non-compliant or fail to attend regularly

  6. Nanostructured nanoparticles of self-assembled lipid pro-drugs as a route to improved chemotherapeutic agents.

    PubMed

    Sagnella, Sharon M; Gong, Xiaojuan; Moghaddam, Minoo J; Conn, Charlotte E; Kimpton, Kathleen; Waddington, Lynne J; Krodkiewska, Irena; Drummond, Calum J

    2011-03-01

    We demonstrate that oral delivery of self-assembled nanostructured nanoparticles consisting of 5-fluorouracil (5-FU) lipid prodrugs results in a highly effective, target-activated, chemotherapeutic agent, and offers significantly enhanced efficacy over a commercially available alternative that does not self-assemble. The lipid prodrug nanoparticles have been found to significantly slow the growth of a highly aggressive mouse 4T1 breast tumour, and essentially halt the growth of a human MDA-MB-231 breast tumour in mouse xenografts. Systemic toxicity is avoided as prodrug activation requires a three-step, enzymatic conversion to 5-FU, with the third step occurring preferentially at the tumour site. Additionally, differences in the lipid prodrug chemical structure and internal nanostructure of the nanoparticle dictate the enzymatic conversion rate and can be used to control sustained release profiles. Thus, we have developed novel oral nanomedicines that combine sustained release properties with target-selective activation.

  7. Nanostructured nanoparticles of self-assembled lipid pro-drugs as a route to improved chemotherapeutic agents

    SciTech Connect

    Sagnella, Sharon M.; Gong, Xiaojuan; Moghaddam, Minoo J.

    2014-09-24

    We demonstrate that oral delivery of self-assembled nanostructured nanoparticles consisting of 5-fluorouracil (5-FU) lipid prodrugs results in a highly effective, target-activated, chemotherapeutic agent, and offers significantly enhanced efficacy over a commercially available alternative that does not self-assemble. The lipid prodrug nanoparticles have been found to significantly slow the growth of a highly aggressive mouse 4T1 breast tumour, and essentially halt the growth of a human MDA-MB-231 breast tumour in mouse xenografts. Systemic toxicity is avoided as prodrug activation requires a three-step, enzymatic conversion to 5-FU, with the third step occurring preferentially at the tumour site. Additionally, differences in the lipidmore » prodrug chemical structure and internal nanostructure of the nanoparticle dictate the enzymatic conversion rate and can be used to control sustained release profiles. Thus, we have developed novel oral nanomedicines that combine sustained release properties with target-selective activation.« less

  8. Pharmacokinetics of amino acid ester prodrugs of Acyclovir after oral administration: Interaction with the transporters on Caco-2 cells

    PubMed Central

    Katragadda, Suresh; Jain, Ritesh; Kwatra, Deep; Hariharan, Sudharshan; Mitra, Ashim K.

    2008-01-01

    In vivo systemic absorption of the amino acid prodrugs of acyclovir (ACV) after oral administration was evaluated in rats. Stability of the prodrugs, L-Alanine-ACV (AACV), L-Serine-ACV (SACV), L-Isoleucine-ACV (IACV), γ-Glutamate-ACV (EACV) and L-Valine-ACV (VACV) was evaluated in various tissues. Interaction of these prodrugs with the transporters on Caco-2 cells was studied. In vivo systemic bioavailability of these prodrugs upon oral administration was evaluated in jugular vein cannulated rats. The amino acid ester prodrugs showed affinity towards various amino acid transporters as well as the peptide transporter on the Caco-2 cells. In terms of stability, EACV was most enzymatically stable compared to other prodrugs especially in liver homogenate. In oral absorption studies, ACV and AACV showed high terminal elimination rate constants (λz). SACV and VACV exhibited approximately five fold increase in area under the curve (AUC) values relative to ACV (p<0.05). Cmax(T) (maximum concentration) of SACV was observed to be 39 ± 22 µM in plasma which is 2 times better than VACV and 15 times better than ACV. Clast(T) (concentration at the last time point) of SACV was observed to be 0.18 ± 0.06 µM in plasma which is 2 times better than VACV and 3 times better than ACV. Amino acid ester prodrugs of ACV were absorbed at varying amounts (Cmax) and eliminated at varying rates (λz) thereby leading to varying extents (AUC). The amino acid ester prodrug SACV owing to its enhanced stability, higher AUC and better concentration at last time point seems to be a promising candidate for the oral treatment of herpes infections. PMID:18638532

  9. Synthesis of mutual azo prodrugs of anti-inflammatory agents and peptides facilitated by α-aminoisobutyric acid.

    PubMed

    Kennedy, David A; Vembu, Nagarajan; Fronczek, Frank R; Devocelle, Marc

    2011-12-02

    Reported is the synthesis of azo mutual prodrugs of the nonsteroidal anti-inflammatory agents (NSAIDs) 4-aminophenylacetic acid (4-APAA) or 5-aminosalicylic acid (5-ASA) with peptides, including an antibiotic peptide temporin analogue modified at the amino terminal by an α-aminoisobutyric acid (Aib) residue. These prodrugs are designed for colonic delivery of two agents to treat infection and inflammation by the bacterial pathogen Clostridium difficile . © 2011 American Chemical Society

  10. Evaluation of the “Steal” Phenomenon on the Efficacy of Hypoxia Activated Prodrug TH-302 in Pancreatic Cancer

    PubMed Central

    Ibrahim-Hashim, Arig; Wojtkowiak, Jonathan W.; Hart, Charles P.; Zhang, Xiaomeng; Leos, Rafael; Martinez, Gary V.; Baker, Amanda F.; Gillies, Robert J.

    2014-01-01

    Pancreatic ductal adenocarcinomas are desmoplastic and hypoxic, both of which are associated with poor prognosis. Hypoxia-activated prodrugs (HAPs) are specifically activated in hypoxic environments to release cytotoxic or cytostatic effectors. TH-302 is a HAP that is currently being evaluated in a Phase III clinical trial in pancreatic cancer. Using animal models, we show that tumor hypoxia can be exacerbated using a vasodilator, hydralazine, improving TH-302 efficacy. Hydralazine reduces tumor blood flow through the “steal” phenomenon, in which atonal immature tumor vasculature fails to dilate in coordination with normal vasculature. We show that MIA PaCa-2 tumors exhibit a “steal” effect in response to hydralazine, resulting in decreased tumor blood flow and subsequent tumor pH reduction. The effect is not observed in SU.86.86 tumors with mature tumor vasculature, as measured by CD31 and smooth muscle actin (SMA) immunohistochemistry staining. Combination therapy of hydralazine and TH-302 resulted in a reduction in MIA PaCa-2 tumor volume growth after 18 days of treatment. These studies support a combination mechanism of action for TH-302 with a vasodilator that transiently increases tumor hypoxia. PMID:25532146

  11. Mitochondrial Uncoupler Prodrug of 2,4-Dinitrophenol, MP201, Prevents Neuronal Damage and Preserves Vision in Experimental Optic Neuritis

    PubMed Central

    Khan, Reas S.; Geisler, John G.

    2017-01-01

    The ability of novel mitochondrial uncoupler prodrug of 2,4-dinitrophenol (DNP), MP201, to prevent neuronal damage and preserve visual function in an experimental autoimmune encephalomyelitis (EAE) model of optic neuritis was evaluated. Optic nerve inflammation, demyelination, and axonal loss are prominent features of optic neuritis, an inflammatory optic neuropathy often associated with the central nervous system demyelinating disease multiple sclerosis. Currently, optic neuritis is frequently treated with high-dose corticosteroids, but treatment fails to prevent permanent neuronal damage and associated vision changes that occur as optic neuritis resolves, thus suggesting that additional therapies are required. MP201 administered orally, once per day, attenuated visual dysfunction, preserved retinal ganglion cells (RGCs), and reduced RGC axonal loss and demyelination in the optic nerves of EAE mice, with limited effects on inflammation. The prominent mild mitochondrial uncoupling properties of MP201, with slow elimination of DNP, may contribute to the neuroprotective effect by modulating the entire mitochondria's physiology directly. Results suggest that MP201 is a potential novel treatment for optic neuritis. PMID:28680531

  12. Corrosion-Activated Chemotherapeutic Function of Nanoparticulate Platinum as a Cisplatin Resistance-Overcoming Prodrug with Limited Autophagy Induction.

    PubMed

    Cheng, Hsien-Jen; Wu, Te-Haw; Chien, Chih-Te; Tu, Hai-Wei; Cha, Ting-Shan; Lin, Shu-Yi

    2016-11-01

    Despite nanoparticulate platinum (nano-Pt) has been validated to be acting as a platinum-based prodrug for anticancer therapy, the key factor in controlling its cytotoxicity remains to be clarified. In this study, it is found that the corrosion susceptibility of nano-Pt can be triggered by inducing the oxidization of superficial Pt atoms, which can kill both cisplatin-sensitive/resistance cancer cells. Direct evidence in the oxidization of superficial Pt atoms is validated to observe the formation of platinum oxides by X-ray absorption spectroscopy. The cytotoxicity is originated from the dissolution of nano-Pt followed by the release of highly toxic Pt ions during the corrosion process. Additionally, the limiting autophagy induction by nano-Pt might prevent cancer cells from acquiring autophagy-related drug resistance. With such advantages, the possibility of further autophagy-related drug resistance could be substantially reduced or even eliminated in cancer cells treated with nano-Pt. Moreover, nano-Pt is demonstrated to kill cisplatin-resistant cancer cells not only by inducing apoptosis but also by inducing necrosis for pro-inflammatory/inflammatory responses. Thus, nano-Pt treatment might bring additional therapeutic benefits by regulating immunological responses in tumor microenvironment. These findings support the idea that utilizing nano-Pt for its cytotoxic effects might potentially benefit patients with cisplatin resistance in clinical chemotherapy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Product release mechanism and the complete enzyme catalysis cycle in yeast cytosine deaminase (yCD): A computational study.

    PubMed

    Zhao, Yuan; She, Nai; Zhang, Xin; Wang, Chaojie; Mo, Yirong

    2017-08-01

    Yeast cytosine deaminase (yCD) is critical in gene-directed enzyme prodrug therapy as it catalyzes the hydrolytic deamination of cytosine. The product (uracil) release process is considered as rate-limiting in the whole enzymatic catalysis and includes the cleavage of the uracil-metal bond and the delivery of free uracil out of the reactive site. Herein extensive combined random acceleration molecular dynamics (RAMD) and molecular dynamics (MD) simulations coupled with the umbrella sampling technique have been performed to study the product transport mechanism. Five channels have been identified, and the thermodynamic and dynamic characterizations for the two most favorable channels have been determined and analyzed. The free energy barrier for the most beneficial pathway is about 13kcal/mol and mainly results from the cleavage of hydrogen bonds between the ligand uracil and surrounding residues Asn51, Glu64, and Asp155. The conjugated rings of Phe114 and Trp152 play gating and guiding roles in the product delivery via π⋯π van der Waals interactions with the product. Finally, the full cycle of the enzymatic catalysis has been determined, making the whole process computationally more precise. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Enzyme actuated bioresponsive hydrogels

    NASA Astrophysics Data System (ADS)

    Wilson, Andrew Nolan

    Bioresponsive hydrogels are emerging with technological significance in targeted drug delivery, biosensors and regenerative medicine. Conferred with the ability to respond to specific biologically derived stimuli, the design challenge is in effectively linking the conferred biospecificity with an engineered response tailored to the needs of a particular application. Moreover, the fundamental phenomena governing the response must support an appropriate dynamic range and limit of detection. The design of these systems is inherently complicated due to the high interdependency of the governing phenomena that guide the sensing, transduction, and the actuation response of hydrogels. To investigate the dynamics of these materials, model systems may be used which seek to interrogate the system dynamics by uni-variable experimentation and limit confounding phenomena such as: polymer-solute interactions, polymer swelling dynamics and biomolecular reaction-diffusion concerns. To this end, a model system, alpha-chymotrypsin (Cht) (a protease) and a cleavable peptide-chromogen (pro-drug) covalently incorporated into a hydrogel, was investigated to understand the mechanisms of covalent loading and release by enzymatic cleavage in bio-responsive delivery systems. Using EDC and Sulfo-NHS, terminal carboxyl groups of N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide, a cleavable chromogen, were conjugated to primary amines of a hydrated poly(HEMA)-based hydrogel. Hydrogel discs were incubated in buffered Cht causing enzyme-mediated cleavage of the peptide and concomitant release of the chromophore for monitoring. To investigate substrate loading and the effects of hydrogel morphology on the system, the concentration of the amino groups (5, 10, 20, and 30 mol%) and the cross-linked density (1, 5, 7, 9 and 12 mol%) were independently varied. Loading-Release Efficiency of the chromogen was shown to exhibit a positive relation to increasing amino groups (AEMA). The release rates demonstrated a

  15. Tailoring acyclovir prodrugs with enhanced antiviral activity: rational design, synthesis, human plasma stability and in vitro evaluation.

    PubMed

    Chayrov, Radoslav L; Stylos, Evgenios K; Chatziathanasiadou, Maria V; Chuchkov, Kiril N; Tencheva, Aleksandra I; Kostagianni, Androniki D; Milkova, Tsenka S; Angelova, Assia L; Galabov, Angel S; Shishkov, Stoyan A; Todorov, Daniel G; Tzakos, Andreas G; Stankova, Ivanka G

    2018-05-19

    Bile acid prodrugs have served as a viable strategy for refining the pharmaceutical profile of parent drugs through utilizing bile acid transporters. A series of three ester prodrugs of the antiherpetic drug acyclovir (ACV) with the bile acids cholic, chenodeoxycholic and deoxycholic were synthesized and evaluated along with valacyclovir for their in vitro antiviral activity against herpes simplex viruses type 1 and type 2 (HSV-1, HSV-2). The in vitro antiviral activity of the three bile acid prodrugs was also evaluated against Epstein-Barr virus (EBV). Plasma stability assays, utilizing ultra-high performance liquid chromatography coupled with tandem mass spectrometry, in vitro cytotoxicity and inhibitory experiments were conducted in order to establish the biological profile of ACV prodrugs. The antiviral assays demonstrated that ACV-cholate had slightly better antiviral activity than ACV against HSV-1, while it presented an eight-fold higher activity with respect to ACV against HSV-2. ACV-chenodeoxycholate presented a six-fold higher antiviral activity against HSV-2 with respect to ACV. Concerning EBV, the highest antiviral effect was demonstrated by ACV-chenodeoxycholate. Human plasma stability assays revealed that ACV-deoxycholate was more stable than the other two prodrugs. These results suggest that decorating the core structure of ACV with bile acids could deliver prodrugs with amplified antiviral activity.

  16. Tyrosine hydroxylase (TH), its cofactor tetrahydrobiopterin (BH4), other catecholamine-related enzymes, and their human genes in relation to the drug and gene therapies of Parkinson's disease (PD): historical overview and future prospects.

    PubMed

    Nagatsu, Toshiharu; Nagatsu, Ikuko

    2016-11-01

    Tyrosine hydroxylase (TH), which was discovered at the National Institutes of Health (NIH) in 1964, is a tetrahydrobiopterin (BH4)-requiring monooxygenase that catalyzes the first and rate-limiting step in the biosynthesis of catecholamines (CAs), such as dopamine, noradrenaline, and adrenaline. Since deficiencies of dopamine and noradrenaline in the brain stem, caused by neurodegeneration of dopamine and noradrenaline neurons, are mainly related to non-motor and motor symptoms of Parkinson's disease (PD), we have studied human CA-synthesizing enzymes [TH; BH4-related enzymes, especially GTP-cyclohydrolase I (GCH1); aromatic L-amino acid decarboxylase (AADC); dopamine β-hydroxylase (DBH); and phenylethanolamine N-methyltransferase (PNMT)] and their genes in relation to PD in postmortem brains from PD patients, patients with CA-related genetic diseases, mice with genetically engineered CA neurons, and animal models of PD. We purified all human CA-synthesizing enzymes, produced their antibodies for immunohistochemistry and immunoassay, and cloned all human genes, especially the human TH gene and the human gene for GCH1, which synthesizes BH4 as a cofactor of TH. This review discusses the historical overview of TH, BH4-, and other CA-related enzymes and their genes in relation to the pathophysiology of PD, the development of drugs, such as L-DOPA, and future prospects for drug and gene therapy for PD, especially the potential of induced pluripotent stem (iPS) cells.

  17. An evaluation of serum soluble CD30 levels and serum CD26 (DPPIV) enzyme activity as markers of type 2 and type 1 cytokines in HIV patients receiving highly active antiretroviral therapy

    PubMed Central

    Keane, N M; Price, P; Lee, S; Stone, S F; French, M A

    2001-01-01

    This study evaluates serum CD26 (dipeptidyl peptidase IV, DPPIV) enzyme activity and serum levels of soluble CD30 as markers of T1 and T2 cytokine environments in HIV patients who achieved immune reconstitution after highly active antiretroviral therapy (HAART). Patients who had experienced inflammatory disease associated with pre-existent opportunistic infections after HAART (immune restoration diseases, IRD) were considered separately. Serum sCD30 levels and CD26 (DPPIV) enzyme activity were compared with IFN-γ production by PBMC cultured with cytomegalovirus (CMV) antigen in controls and patient groups. High sCD30 levels were associated with low IFN-γ production after antigenic stimulation in control subjects and, to a lesser extent, in immune reconstituted HIV patients. There was no association between serum CD26 (DPPIV) enzyme activity and IFN-γ production or sCD30 levels. Serum sCD30 levels and CD26 (DPPIV) enzyme activity were significantly increased in immune reconstituted patients with high HIV viral loads. Patients who had experienced CMV retinitis as an IRD had significantly higher sCD30 levels than all other patient groups. Hence, high sCD30 levels may be a marker of a T2 cytokine environment in HIV patients with immune reconstitution and are associated with higher HIV viral loads and a history of CMV associated IRD. PMID:11678906

  18. Sulfur mustard induced mast cell degranulation in mouse skin is inhibited by a novel anti-inflammatory and anticholinergic bifunctional prodrug.

    PubMed

    Joseph, Laurie B; Composto, Gabriella M; Perez, Roberto M; Kim, Hong-Duck; Casillas, Robert P; Heindel, Ned D; Young, Sherri C; Lacey, Carl J; Saxena, Jaya; Guillon, Christophe D; Croutch, Claire R; Laskin, Jeffrey D; Heck, Diane E

    2018-09-01

    Sulfur mustard (SM, bis(2-chloroethyl sulfide) is a potent vesicating agent known to cause skin inflammation, necrosis and blistering. Evidence suggests that inflammatory cells and mediators that they generate are important in the pathogenic responses to SM. In the present studies we investigated the role of mast cells in SM-induced skin injury using a murine vapor cup exposure model. Mast cells, identified by toluidine blue staining, were localized in the dermis, adjacent to dermal appendages and at the dermal/epidermal junction. In control mice, 48-61% of mast cells were degranulated. SM exposure (1.4g/m 3 in air for 6min) resulted in increased numbers of degranulated mast cells 1-14days post-exposure. Treatment of mice topically with an indomethacin choline bioisostere containing prodrug linked by an aromatic ester-carbonate that targets cyclooxygenases (COX) enzymes and acetylcholinesterase (1% in an ointment) 1-14days after SM reduced skin inflammation and injury and enhanced tissue repair. This was associated with a decrease in mast cell degranulation from 90% to 49% 1-3days post SM, and from 84% to 44% 7-14days post SM. These data suggest that reduced inflammation and injury in response to the bifunctional indomethacin prodrug may be due, at least in part, to abrogating mast cell degranulation. The use of inhibitors of mast cell degranulation may be an effective strategy for mitigating skin injury induced by SM. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Pharmacokinetics of penciclovir after oral administration of its prodrug famciclovir to horses.

    PubMed

    Tsujimura, Koji; Yamada, Masayuki; Nagata, Shun-ichi; Yamanaka, Takashi; Nemoto, Manabu; Kondo, Takashi; Kurosawa, Masahiko; Matsumura, Tomio

    2010-03-01

    We investigated the pharmacokinetics of penciclovir after oral administration of its prodrug famciclovir to horses. Following an oral dose of famciclovir at 20 mg/kg, maximum plasma concentrations of penciclovir occurred between 0.75 and 1.5 hr (mean 0.94 + or - 0.38 hr) after dosing and were in the range 2.22 to 3.56 microg/ml (mean 2.87 + or - 0.61 microg/ml). The concentrations of penciclovir declined in a biphasic manner after the peak concentration was attained. The mean half-life of the rapid elimination phase was 1.73 + or - 0.34 hr whereas that of the slow elimination phase was 34.34 + or - 13.93 hr. These pharmacokinetic profiles observed were similar to those of another antiherpesvirus drug, acyclovir, previously reported in horses following oral dosing of its prodrug valacyclovir.

  20. Inhibition of epithelial ovarian cancer by Minnelide, a water-soluble pro-drug.

    PubMed

    Rivard, Colleen; Geller, Melissa; Schnettler, Erica; Saluja, Manju; Vogel, Rachel Isaksson; Saluja, Ashok; Ramakrishnan, Sundaram

    2014-11-01

    Minnelide is a water-soluble pro-drug of triptolide, a natural product. The goal of this study was to evaluate the effectiveness of Minnelide on ovarian cancer growth in vitro and in vivo. The effect of Minnelide on ovarian cancer cell proliferation was determined by real time electrical impedance measurements. Multiple mouse models with C200 and A2780 epithelial ovarian cancer cell lines were used to assess the efficacy of Minnelide in inhibiting ovarian cancer growth. Minnelide decreased cell viability of both platinum sensitive and resistant epithelial ovarian cancer cells in vitro. Minnelide with carboplatin showed additive effects in vitro. Minnelide monotherapy increased the survival of mice bearing established ovarian tumors. Minnelide, in combination with carboplatin and paclitaxel, improved overall survival of mice. Minnelide is a promising pro-drug for the treatment of ovarian cancer, especially when combined with standard chemotherapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. A Versatile Bioorthogonal Copper-free Click Chemistry Platform to Functionalize Cisplatin Prodrugs

    PubMed Central

    Pathak, Rakesh K.; McNitt, Christopher D.; Popik, Vladimir V.; Dhar, Shanta

    2015-01-01

    The ability to rationally design and construct a platform technology to develop new platinum(IV) [Pt(IV)] prodrugs with functionalities for installation of targeting moieties, delivery systems, fluorescent reporters from a single precursor with the ability to release biologically active cisplatin using well-defined chemistry is critical for discovering new platinum-based therapeutics. With limited numbers of possibilities by considering the sensitivity of Pt(IV) centers to reduction, thiols, etc, we used a strain promoted azide alkyne cycloaddition (SPAAC) approach to provide a novel platform where new functionalities can easily be installed on cisplatin prodrugs from a single Pt(IV) precursor. The ability of this platform to be incorporated in nano-delivery vehicle and conjugation to fluorescent reporters were also investigated. PMID:24756923

  2. Copper-free click-chemistry platform to functionalize cisplatin prodrugs.

    PubMed

    Pathak, Rakesh K; McNitt, Christopher D; Popik, Vladimir V; Dhar, Shanta

    2014-06-02

    The ability to rationally design and construct a platform technology to develop new platinum(IV) [Pt(IV)] prodrugs with functionalities for installation of targeting moieties, delivery systems, fluorescent reporters from a single precursor with the ability to release biologically active cisplatin by using well-defined chemistry is critical for discovering new platinum-based therapeutics. With limited numbers of possibilities considering the sensitivity of Pt(IV) centers, we used a strain-promoted azide-alkyne cycloaddition approach to provide a platform, in which new functionalities can easily be installed on cisplatin prodrugs from a single Pt(IV) precursor. The ability of this platform to be incorporated in nanodelivery vehicle and conjugation to fluorescent reporters were also investigated. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Synthesis and in vitro evaluation of potential sustained release prodrugs via targeting ASBT.

    PubMed

    Zheng, Xiaowan; Polli, James E

    2010-08-30

    The objective was to synthesize prodrugs of niacin and ketoprofen that target the human apical sodium-dependent bile acid transporter (ASBT) and potentially allow for prolonged drug release. Each drug was conjugated to the naturally occurring bile acid chenodeoxycholic acid (CDCA) using lysine as a linker. Their inhibitory binding and transport properties were evaluated in stably transfected ASBT-MDCK monolayers, and the kinetic parameters K(i), K(t), normJ(max), and P(p) were characterized. Enzymatic stability of the conjugates was evaluated in Caco-2 and liver homogenate. Both conjugates were potent inhibitors of ASBT. For the niacin prodrug, substrate kinetic parameter K(t) was 8.22microM and normJ(max) was 0.0917. In 4h, 69.4% and 26.9% of niacin was released from 1microM and 5microM of the conjugate in Caco-2 homogenate, respectively. For the ketoprofen prodrug, K(t) was 50.8microM and normJ(max) was 1.58. In 4h, 5.94% and 3.73% of ketoprofen was released from 1microM and 5microM of the conjugate in Caco-2 homogenate, and 24.5% and 12.2% of ketoprofen was released in liver homogenate, respectively. In vitro results showed that these bile acid conjugates are potential prolonged release prodrugs with binding affinity for ASBT. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Transdermal delivery and cutaneous targeting of antivirals using a penetration enhancer and lysolipid prodrugs.

    PubMed

    Diblíková, Denisa; Kopečná, Monika; Školová, Barbora; Krečmerová, Marcela; Roh, Jaroslav; Hrabálek, Alexandr; Vávrová, Kateřina

    2014-04-01

    In this work, we investigate prodrug and enhancer approaches for transdermal and topical delivery of antiviral drugs belonging to the 2,6-diaminopurine acyclic nucleoside phosphonate (ANP) group. Our question was whether we can differentiate between transdermal and topical delivery, i.e., to control the delivery of a given drug towards either systemic absorption or retention in the skin. The in vitro transdermal delivery and skin concentrations of seven antivirals, including (R)- and (S)-9-[2-(phosphonomethoxy)propyl]-2,6-diaminopurine (PMPDAP), (S)-9-[3-hydroxy-2-(phosphonomethoxy)propyl]-2,6-diaminopurine ((S)-HPMPDAP), its 8-aza analog, and their cyclic and hexadecyloxypropyl (HDP) prodrugs, was investigated with and without the penetration enhancer dodecyl-6-(dimethylamino)hexanoate (DDAK) using human skin. The ability of ANPs to cross the human skin barrier was very low (0.5-1.4 nmol/cm(2)/h), and the majority of the compounds were found in the stratum corneum, the uppermost skin layer. The combination of antivirals and the penetration enhancer DDAK proved to be a viable approach for transdermal delivery, especially in case of (R)-PMPDAP, an anti-HIV effective drug (30.2 ± 2.3 nmol/cm(2)/h). On the other hand, lysophospholipid-like HDP prodrugs, e.g., HDP-(S)-HPMPDAP, reached high concentrations in viable epidermis without significant systemic absorption. By using penetration enhancers or lysolipid prodrugs, it is possible to effectively target systemic diseases by the transdermal route or to target cutaneous pathologies by topical delivery.

  5. Pharmacokinetic and pharmacodynamic assessment of bioavailability for two prodrugs of methylprednisolone

    PubMed Central

    Daley-Yates, P. T.; Gregory, A. J.; Brooks, C. D.

    1997-01-01

    Aims The aim of this study was to establish whether pharmacokinetic differences between two pro-drugs of methylprednisolone (MP) are likely to be of clinical significance. Methods This study was a single-blind, randomized, crossover design comparing the bioequivalence of MP released from the pro-drugs Promedrol (MP suleptanate) and Solu-Medrol (MP succinate) after a single 250 mg (MP equivalent) intramuscular injection to 20 healthy male volunteers. Bioequivalence was assessed by conventional pharmacokinetic analysis, by measuring pharmacodynamic responses plus a novel approach using pharmacokinetic/pharmacodynamic modeling. The main measure of pharmacodynamic response was whole blood histamine (WBH), a measure of basophil numbers. Results The MP Cmax was less for MP suleptanate due to a longer absorption half-life of the prodrug from the intramuscular injection site. The bioavailability of MP was equivalent when based on AUC with a MP suleptanate median 108% of the MP succinate value (90%