Nanomedicine Research Center

Taipei, Taiwan

Nanomedicine Research Center

Taipei, Taiwan
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Gupta S.,Nanomedicine Research Center | Pal A.,Nanomedicine Research Center | Vyas S.P.,Drug Delivery Research Laboratory
Expert Opinion on Drug Delivery | Year: 2010

Importance of the field: Visceral leishmaniasis (VL) is the most overwhelming type of leishmaniasis associated with the poverty of developing countries and usually mortal if untreated. Most of the conventionally used dosage forms offer us the shortcomings of toxic side effects and emergence of drug resistance. Several efforts have been made to overcome the barriers involved in the treatment of VL. Colloidal carriers extensively represent the drug delivery systems (DDSs) for intracellular localization of antileishmanial compounds in macrophage-rich organs such as liver, spleen and bone marrow. These DDSs offer superior therapeutic efficacy over the conventional treatment in terms of site-specific drug delivery with reduced side effects. However, after 35 years of research in the field, AmBisome® (Amphotericin B liposome for injection, Astellas Pharma US, Inc.) is the only DDS used against the VL. Areas covered in this review: A literature search was performed (for drugs and DDSs against VL) on PubMed and through Google. What the reader will gain: This review aims to describe the pathophysiology of VL and its current conventional treatment with special reference to DDSs designed against VL. Take home message: On reviewing the conventional drugs and DDSs developed against VL, it is concluded that advances in the field of targeted drug delivery can result in more efficient strategies for the therapy of VL. © 2010 Informa UK Ltd.

Wadhwa S.,Nanomedicine Research Center | Paliwal R.,Nanomedicine Research Center | Paliwal S.R.,Nanomedicine Research Center | Vyas S.P.,Nanomedicine Research Center
Journal of Drug Targeting | Year: 2010

In clinical practices, solution of dorzolamide hydrochloride (DH) and timolol maléate (TM) is recommended for the treatment of glaucoma. However, low drug-contact time and poor ocular bioavailability of drugs due to drainage of solution, tear turnover and its dilution or lacrimation limits its uses. In addition, systemic absorption of TM may induce undesirable cardiovascular side effects. Chitosan (CS) is a polycationic biodegradable polymer which provides sustained and local delivery of drugs to the ocular sites. Hyaluronic acid (HA) also provides synergistic effect for mucoadhesion in association with chitosan. In the present study, hyaluronic acid modified chitosan nanoparticles (CS-HA-NPs) loaded with TM and DH were developed and characterized. The CS-HA-NPs were evaluated for size, shape, zeta potential, entrapment efficiency, and mucoadhesive strength. The in vitro release study was also performed in PBS pH 7.4. The ocular irritation potential of CS-HA-NPs was estimated using draize test on albino rabbits. A significant reduction in IOP level was obtained using CS-HA-NPs as compared to plain solution of drug and a comparable higher reduction in IOP level was observed as to CS-NPs. These results suggest that HA potentialy enhance the mucoadhesiveness and efficiency of CS-NPs and may be promising carrier for ocular drug delivery. © 2010 Informa UK Ltd.

Gupta S.,Nanomedicine Research Center | Gupta S.,Drug Delivery Research Laboratory | Vyas S.P.,Drug Delivery Research Laboratory
Scientia Pharmaceutica | Year: 2010

The poor bioavailability and therapeutic response exhibited by conventional ophthalmic preparations due to rapid precorneal elimination, dilution and nasolacrimal drainage of the drug may be vanquished by the use of in situ gelling systems that are instilled as drops in to the eye and undergo a sol-gel transition in the cul-de-sac. Timolol eye drops may cause systemic side effects in glaucoma patients due to absorption of the drug into systemic circulation. In situ gelling system of this drug can provide localized effect with reduced contraindications, improved patient compliance and better therapeutic index. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antiglaucoma drug, timolol maleate (TM) based on the concept of pH-triggered in situ gelation. Polyacrylic acid (carbopol) was used as the gelling agent in combination with chitosan (amine polysaccharide), which was acted as a viscosity-enhancing agent. Formulations were evaluated for pH, viscosity, gelling capacity and drug content. The 0.4% w/v carbopol/0.5% w/v chitosan based in situ gelling system was in liquid state at room temperature and at the pH formulated (pH 6.0) and underwent rapid transition into the viscous gel phase at the pH of the tear fluid (lacrimal fluid) (pH 7.4). The in vitro drug release and in vivo effects of the developed in situ gelling system were compared with that of Glucomol® (a 0.25% TM ophthalmic solution), 0.4% w/v carbopol solution as well as liposomal formulation. The results clearly demonstrated that developed carbopol-chitosan based formulation was therapeutically efficacious and showed a fickian (diffusion controlled) type of release behaviour over 24 h periods. The developed system is thus a viable alternative to conventional eye drops and can also prevent the rapid drainage as in case of liposomes. © Gupta and Vyas.

Vaidya B.,Dr Hari Singh Gour University | Vaidya B.,Nanomedicine Research Center | Vyas S.P.,Dr Hari Singh Gour University
Journal of Drug Targeting | Year: 2012

Objectives: In the present study attempt has been made to enhance the selective tumor cell killing in mouse xenograft model using DQAsomes as a mitochondriotropic carrier and transferrin (Tf) as a ligand to target tumor cells. Methods: Tf modified DQAsomes (Tf-DQAsomes) were prepared by incubating preformed paclitaxel loaded DQAsomes with Tf in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride. Developed systems were characterized for size and size distribution, entrapment efficiency, and in vitro drug release. Fluorescence microscopy and flow cytometry were performed to evaluate cellular uptake of the carriers. Antitumor activity was determined using HeLa cells. In vivo therapeutic efficacy was determined in xenograft mouse model. Key findings: Uptake studies demonstrated that Tf-DQAsomes result in higher flurescence intensity to the cancer cells as compared to plain DQAsomes. Tf-DQAsomes exhibited better antitumor activity in vitro as compared to plain DQAsomes and paclitaxel solution. In vivo biodistribution study revealed that paclitaxel concentration in the tumor was much higher in the case of Tf-DQAsomes as compared to plain DQAsomes and paclitaxel solution; however in other organs it was much lower than the latter two formulations. Tf-DQAsomes exhibited significant antitumor activity in the mouse xenograft model. Conclusions: The finding demonstrated that Tf conjugated DQAsomes can effectively be delivered to the tumor in vivo and exhibit significant antitumor activity. © 2012 Informa UK, Ltd.

Arora S.,Nanomedicine Research Center | Budhiraja R.D.,Nanomedicine Research Center
Journal of Advanced Pharmaceutical Technology and Research | Year: 2012

Amoxicillin-loaded microcapsules were prepared by ionotropic gelation of sodium alginate (ALG) with chitosan (CS) in presence of calcium chloride as gastroretentive delivery system. The effect of pH, concentration of ALG, CS and calcium chloride, and drug : ALG ratio were optimized in this study for minimizing the degradation of drug in acidic environment and increasing the loading efficacy and mucoadhesive efficiency of microcapsules. The optimum condition for prepared CS-ALG microcapsules was 2%w/v ALG, 0.75%w/v CS (pH5.0), and 1.0% w/v calcium chloride. The resulting microcapsules had drug entrapment efficiency of 84% and average size of 840 mm. CS concentration significantly influenced particle size and encapsulation efficiency of CS-ALG microcapsules (P<0.05). Decrease in the drug: ALG ratio resulted in an increased release of amoxicillin in acidic media. The relative decomposition of drug after encapsulation in CS-ALG microcapsules was decreased to 20.7%, 41.9%, and 83.3% in 2, 4, and 8 hours, respectively.

Sood N.,Nanomedicine Research Center | Bhardwaj A.,Nanomedicine Research Center | Mehta S.,Nanomedicine Research Center | Mehta A.,Nanomedicine Research Center
Drug Delivery | Year: 2016

Hydrogels are the three-dimensional network structures obtained from a class of synthetic or natural polymers which can absorb and retain a significant amount of water. Hydrogels are one of the most studied classes of polymer-based controlled drug release. These have attracted considerable attention in biochemical and biomedical fields because of their characteristics, such as swelling in aqueous medium, biocompatibility, pH and temperature sensitivity or sensitivity towards other stimuli, which can be utilized for their controlled zero-order release. The hydrogels are expected to explore new generation of self-regulated delivery system having a wide array of desirable properties. This review highlights the exciting opportunities and challenges in the area of hydrogels. Here, we review different literatures on stimuli-sensitive hydrogels, such as role of temperature, electric potential, pH and ionic strength to control the release of drug from hydrogels. © 2014 Informa Healthcare USA, Inc.

Khan W.,Hebrew University of Jerusalem | Hosseinkhani H.,National Taiwan University of Science and Technology | Ickowicz D.,Hebrew University of Jerusalem | Hong P.-D.,National Taiwan University of Science and Technology | And 2 more authors.
Acta Biomaterialia | Year: 2012

Gene delivery is a promising technique that involves in vitro or in vivo introduction of exogenous genes into cells for experimental and therapeutic purposes. Successful gene delivery depends on the development of effective and safe delivery vectors. Two main delivery systems, viral and non-viral gene carriers, are currently deployed for gene therapy. While most current gene therapy clinical trials are based on viral approaches, non-viral gene medicines have also emerged as potentially safe and effective for the treatment of a wide variety of genetic and acquired diseases. Non-viral technologies consist of plasmid-based expression systems containing a gene associated with the synthetic gene delivery vector. Polysaccharides compile a large family of heterogenic sequences of monomers with various applications and several advantages as gene delivery agents. This chapter, compiles the recent progress in polysaccharide based gene delivery, it also provides an overview and recent developments of polysaccharide employed for in vitro and in vivo delivery of therapeutically important nucleotides, e.g. plasmid DNA and small interfering RNA. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Hosseinkhani H.,National Taiwan University of Science and Technology | Hong P.-D.,National Taiwan University of Science and Technology | Yu D.-S.,Nanomedicine Research Center
Chemical Reviews | Year: 2013

A chemical review considers the self-assembled systems and the latest developments for their potential applications in regenerative medicine. Self-assembly is a native process, which can be classified into two types, such as static and dynamic. Static selfassembly contributes to systems that are at global or local equilibrium and do not dissipate energy. Dynamic self-assembly occurs when formation of an ordered state of equilibrium requires dissipation of energy. Interactions responsible for formation of structures or patterns between components occur only if the system dissipates energy lead to dynamic self-assembly. Self-assembly also takes place at molecular, mesoscopic, and macroscopic scales. Self-assembly has been classified as molecular and nanoscale self-assemblies and meso- and macroscopic self-assemblies on the basis of this criteria.

Aggarwal S.,Nanomedicine Research Center | Yadav S.,Nanomedicine Research Center | Gupta S.,Nanomedicine Research Center
Journal of Biomedical Nanotechnology | Year: 2011

The present study aimed to prepare and characterize anti EGFR monoclonal antibody (mab) conjugated Gemcitabine loaded PLGA nanoparticles for their selective delivery to pancreatic cells and evaluation of the systems in vitro. It was observed that direct covalent coupling of antibodies to glutaraldehyde activated nanoparticles is an appropriate method to achieve cell-type specific drug carrier systems based on polymeric nanoparticles that have potential to be applied for targeted chemotherapy in EGFR positive cancer. Copyright © 2011 American Scientific Publishers All rights reserved.

Bhardwaj A.,Nanomedicine Research Center
Artificial cells, nanomedicine, and biotechnology (Print) | Year: 2013

Tuberculosis (TB) remains one of the oldest and deadliest diseases in the current scenario. The intracellular organism Mycobacterium tuberculosis, which mainly resides in mononuclear phagocytes, is responsible for tuberculosis in humans. A few therapies are available for the treatment of tuberculosis but they have many hurdles. To overcome these hurdles, a combination of chemotherapeutic agent-loaded vesicular systems have been prepared to overcome tuberculosis. To investigate the role of novel drug delivery systems for the treatment of pulmonary tuberculosis, ligand appended liposomals have been developed. In the present study, drug-loaded, ligand-appended liposomes and their DPI (Dry Powder Inhaler) forms have been prepared and characterized using various in vitro and in vivo parameters. The prepared ligand-appended liposomal formulation showed good entrapment efficiency, prolonged drug release, improved recovery of drugs from the target site, and proved to be more suitable for use as DPI, justifying their potential for improved drug delivery. Thus we tried our best by our project to reduce the national burden of tuberculosis, which is still a global health challenge.

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