Ashish Kumar Agrawal

Improved stability and antidiabetic potential of insulin containing folic acid functionalized polymer stabilized multilayered liposomes following oral administration.

The present study reports the folic acid (FA) functionalized insulin loaded stable liposomes with improved bioavailability following oral administration. Liposomes were stabilized by alternating coating of negatively charged poly(acrylic acid) (PAA) and positively charged poly(allyl amine) hydrochloride (PAH) over liposomes. Furthermore, folic acid was appended as targeting ligand by synthesizing folic acid-poly(allyl amine) hydrochloride conjugate. The insulin entrapped within the freeze-dried formulation was found stable both chemically as well as conformationally and developed formulation exhibited excellent stability in simulated biological fluids. Caco-2 cell and ex vivo intestinal uptake studies revealed higher uptake of folic acid functionalized layersomes in comparison with their plain counterparts. In vivo pharmacodynamic and pharmacokinetic studies further revealed almost double hypoglycemia and approximately 20% relative bioavailability in comparison with subcutaneously administered standard insulin solution. Overall the proposed strategy is expected to contribute significantly in the field of designing ligand-anchored, polyelectrolyte-based stable systems in drug delivery.

In situ gel systems as ‘smart’ carriers for sustained ocular drug delivery

Introduction: In situ gel systems refer to a class of novel delivery vehicles, composed of natural, semisynthetic or synthetic polymers, which present the unique property of sol–gel conversion on receipt of biological stimulus. Areas covered: The present review summarizes the latest developments in in situ gel technology, with regard to ophthalmic drug delivery. Starting with the mechanism of ocular absorption, the review expands on the fabrication of various polymeric in situ gel systems, made up of two or more polymers presenting multi-stimuli sensitivity, coupled with other interesting features, such as bio-adhesion, enhanced penetration or sustained release. Various key issues and challenges in this area have been addressed and critically analyzed. Expert opinion: The advent of in situ gel systems has inaugurated a new transom for ‘smart’ ocular delivery. By virtue of possessing stimuli-responsive phase transition properties, these systems can easily be administered into the eye, similar to normal eye drops. Their unique gelling properties endow them with special features, such as prolonged retention at the site of administration, followed by sustained drug release. Despite the superiority of these systems as compared with conventional ophthalmic formulations, further investigations are necessary to address the toxicity issues, so as to minimize regulatory hurdles during commercialization.

Improved stability and immunological potential of tetanus toxoid containing surface engineered bilosomes following oral administration

UNLABELLED The present study was designed with the objective to investigate the stability and potential of glucomannan-modified bilosomes (GM-bilosomes) in eliciting immune response following oral administration. GM-bilosomes exhibited desired quality attributes simultaneously maintaining the chemical and conformation stability of the tetanus toxoid (TT) entrapped in to freeze dried formulations. The GM-bilosomes exhibited excellent stability in different simulated biological fluids and sustained release profile up to 24 h. GM-bilosomes elicited significantly higher (P<0.05) systemic immune response (serum IgG level) as compared to bilosomes, niosomes and alum adsorbed TT administered through oral route. More importantly, GM-bilosomes were found capable of inducing mucosal immune response, i.e. sIgA titre in salivary and intestinal secretions as well as cell mediated immune response (IL-2 and IFN-γ levels in spleen homogenate) which was not induced by i.m. TT, the conventional route of immunization. Conclusively, GM-bilosomes could be considered as a promising carrier and adjuvant system for oral mucosal immunization. FROM THE CLINICAL EDITOR This team reports on the development and effects of a glucomannan-modified bilosome as an oral vaccine vector, using tetanus toxoid in the experiments. These GM-bilosomes not only elicited significantly higher systemic immune response as compared to bilosomes, niosomes and alum adsorbed orally administered TT, but also demonstrated mucosal immune response induction as well as cell mediated immune responses, which were not induced by the conventional route of immunization.

Exosomal formulation enhances therapeutic response of celastrol against lung cancer

Celastrol (CEL), a plant-derived triterpenoid, is a known inhibitor of Hsp90 and NF-κB activation pathways and has recently been suggested to be of therapeutic importance in various cancers. However, the molecular mechanisms of celastrol-mediated effects in lung cancer are not systematically studied. Moreover, it suffers from poor bioavailability and off-site toxicity issues. This study aims to study the effect of celastrol loaded into exosomes against two non-small cell-lung carcinoma (NSCLC) cell lines and explore the molecular mechanisms to determine the proteins governing the cellular responses. We observed that celastrol inhibited the proliferation of A549 and H1299 NSCLC cells in a time- and concentration-dependent manner as indexed by MTT assay. Mechanistically, CEL pre-treatment of H1299 cells completely abrogated TNFα-induced NF-κB activation and upregulated the expression of ER-stress chaperones Grp 94, Grp78, and pPERK. These changes in ER-stress mediators were paralleled by an increase in apoptotic response as evidenced by higher annexin-V/PI positive cells evaluated by FACS and immunoblotting which showed upregulation of the ER stress specific pro-apoptotic transcription factor, GADD153/CHOP and alteration of Bax/Bcl2 levels. Exosomes loaded with CEL exhibited enhanced anti-tumor efficacy as compared to free CEL against lung cancer cell xenograft. CEL did not exhibit any gross or systemic toxicity in wild-type C57BL6 mice as determined by hematological and liver and kidney function test. Together, our data demonstrate the chemotherapeutic potential of CEL in lung cancer and that exosomal formulation enhances its efficacy and reduces dose related toxicity.

Tetanus Toxoids Loaded Glucomannosylated Chitosan Based Nanohoming Vaccine Adjuvant with Improved Oral Stability and Immunostimulatory Response

PurposeThe present report embarks on rational designing of stable and functionalized chitosan nanoparticles for oral mucosal immunization.MethodsStable glucomannosylated sCh-GM-NPs were prepared by tandem cross linking method followed by lyophilization. The in vitro stability of antigen and formulation, cellular uptake and immunostimulatory response were assessed by suitable experimental protocol.ResultsStability testing ensured the chemical and conformation permanency of encapsulated TT as well as robustness of sCh-GM-NPs in simulated biological media. The antigen release from sCh-GM-NPs followed initial burst followed by controlled Weibull’s type of release profile. The higher intracellular uptake of sCh-GM-NPs in Raw 264.7 and Caco-2 was concentration and time dependent which mainly attributed to Clathrin and receptor mediated endocytosis via mannose and glucose receptor. The in vivo evaluation in animals revealed that sCh-GM-NPs posed significantly (p < 0.001) higher humoral, mucosal and cellular immune response than other counterparts. More importantly, commercial TT vaccine administered through oral or intramuscular route was unable to elicit all type of immune response.ConclusionThe sCh-GM-NPs could be considered as promising vaccine adjuvant for oral tetanus immunization. Additionally, this technology expected to benefit the design and development of stable peroral formulation for administration of protein, peptides and variety of other antigens.

Milk-derived exosomes for oral delivery of paclitaxel

In this report milk-derived exosomes have been investigated for oral delivery of the chemotherapeutic drug paclitaxel (PAC) as an alternative to conventional i.v. therapy for improved efficacy and reduced toxicity. PAC-loaded exosomes (ExoPAC) were found to have a particle size of ~108 nm, a narrow particle size distribution (PDI ~0.190), zeta potential (~ -7 mV) and a practical loading efficiency of ~8%. Exosomes and ExoPAC exhibited excellent stability in the presence of simulated-gastrointestinal fluids, and during the storage at -80 °C. A sustained release of PAC was also observed up to 48 h in vitro using PBS (pH 6.8). Importantly, ExoPAC delivered orally showed significant tumor growth inhibition (60%; P<0.001) against human lung tumor xenografts in nude mice. Treatment with i.p. PAC at the same dose as ExoPAC, however, showed modest but statistically insignificant inhibition (31%). Moreover, ExoPAC demonstrated remarkably lower systemic and immunologic toxicities as compared to i.v. PAC.

Enhanced transfection efficiency and reduced cytotoxicity of novel lipid-polymer hybrid nanoplexes.

The present study reports the development, characterization, and evaluation of novel polyelectrolytes stabilized lipoplexes as a nonviral vector for gene delivery. In order to achieve the advantage of both DOTAP (1,2-dioleoyl-3-trimethylammonium propane) and PEI (high transfection efficiency) a system was hypothesized in which DOTAP/phosphatidyl choline (PC) lipoplexes were electrostatically coated with anionic poly(acrylic acid) (PAA) and cationic polyethylenimine (PEI) alternatively to finally shape a robust structure PEI-PAA-DOTAP/PC-lipoplexes (nanoplexes). The nanoplexes were found to have size of 242.6 ± 9.4 nm and zeta potential of +23.1 ± 1.5 mV. Following development nanoplexes were evaluated for cellular uptake, nuclear colocalization, transfection efficiency, and cellular toxicity in MCF-7, HeLa, and HEK-293 cell lines. In support of our hypothesis nanoplexes exhibited higher uptake and nuclear colocalization in comparison with DOTAP/PC, DOTAP/DOPE lipoplexes, and PEI polyplexes. Nanoplexes also exhibited 50-80, 11-12, 6-7, and 5-6 fold higher transfection efficiency in comparison with DOTAP/PC-lipoplexes, DOTAP/DOPE-lipoplexes, PEI-polyplexes, and lipofectamine, respectively, and significantly lower toxicity in comparison with DOTAP/PC, DOTAP/DOPE lipoplexes, PEI polyplexes, and commercial lipofectamine.

Enhanced Antitumor Efficacy and Reduced Toxicity of Docetaxel Loaded Estradiol Functionalized Stealth Polymeric Nanoparticles.

In spite of extensive research over the decades, breast cancer treatment is still a major challenge due to nonspecific distribution of the chemotherapeutics. This void can be filled by restricting the distribution of chemotherapeutics toward the cancerous cells. In the present report estradiol (E2) functionalization of docetaxel (DTX) loaded PLGA nanoparticles was supposed to have specific distribution of DTX to cancerous cells simultaneously avoiding the nonspecific distribution toward the normal cells. In line, E2-PEG-PLGA conjugate was synthesized and characterized by FTIR and NMR spectroscopy. Extensive optimization of different process variables resulted in the formation of spherical E2-PEG-PLGA NPs in the size range of 228.5 ± 11.8 nm and entrapment efficiency of 94.25 ± 2.49. Trehalose (5% w/v) resulted in the formation of a fluffy, easy to redisperse freeze-dried cake of nanoparticles. PXRD analysis revealed the amorphous nature of DTX encapsulated within the nanoparticles. X-ray photoelectron spectroscopy confirmed the presence of E2 over the surface of nanoparticles. In line with our hypothesis, cellular uptake studies on ER positive MCF-7 cells revealed relatively higher uptake and efficient localization into the nuclear region of E2-PEG-PLGA NPs in comparison with plain counterparts, while in the case of ER negative HeLa cells E2-PEG-PLGA NPs showed no difference in fluorescence pattern as compared to MCF-7 cells incubated with unmodified nanoformulation, indicating nonspecific delivery of DTX. Moreover, MTT assay revealed relatively higher cytotoxicity of E2-PEG-PLGA NPs in comparison with free DTX. Furthermore, in vivo pharmacokinetic studies revealed 9.36- and 4.79-fold enhancement in circulation half-life and AUC(0-∞), respectively, of E2-PEG-PLGA NPs in comparison with Taxotere. In vivo antitumor efficacy in DMBA induced rat model demonstrated significant reduction in tumor volume in comparison with the plain counterpart (PLGA-NPs) and a marketed formulation, Taxotere. Moreover, the safety of the estradiol functionalized PLGA NPs was confirmed by hepato- and nephrotoxicity studies.

Macromolecular Bipill of Gemcitabine and Methotrexate Facilitates Tumor-Specific Dual Drug Therapy with Higher Benefit-to-Risk Ratio

The present study reports the synthesis, characterization, and biological evaluation of a novel macromolecular bipill, synthesized by appending two different anticancer agents, viz., gemcitabine (GEM) and methotrexate (MTX), to the distal ends of a long-circulating poly(ethylene glycol) (PEG) spacer. Covalent conjugation of GEM and MTX via PEG linker not only transformed the solubility profiles of constituent drug molecules, but significantly improved their stability in the presence of plasma. In vitro cytotoxicity studies confirmed that GEM-PEG-MTX exerts higher cytotoxicity (IC50 0.181 μM at 24 h) in human breast adenocarcinoma MCF-7 cell lines, when compared to free drug congeners, i.e., free GEM (IC50 0.294 μM at 24 h) and free MTX (IC50 0.591 μM at 24 h). Tumor growth inhibition studies in chemically induced breast cancer bearing rats established the superiority of GEM-PEG-MTX conjugate over all other pharmaceutical preparations including free drugs, physical mixture of GEM and MTX, and PEGylated GEM/MTX. Toxicity studies in tumor bearing rats as well as healthy mice corroborated that dual drug conjugation is an effective means to synergize the therapeutic indices of potential drug candidates while alleviating drug-associated side effects.

Novel drug delivery system: an immense hope for diabetics

Abstract Context: Existing medication systems for the treatment of diabetes mellitus (DM) are inconvenient and troublesome for effective and safe delivery of drugs to the specific site. Therefore, investigations are desired to deliver antidiabetics using novel delivery approaches followed by their commercialization. Objective: The present review aims to provide a compilation on the latest development in the field of novel drug delivery systems (NDDSs) for antidiabetics with special emphasis on particulate, vesicular and miscellaneous systems. Methods: Review of literature (restricted to English language only) was done using electronic databases like Pubmed® and Scirus, i.e. published during 2005–2013. The CIMS/MIMS India Medical Drug Information eBook was used regarding available marketed formulation of antidiabetic drugs. Keywords used were “nanoparticle”, “microparticle”, “liposomes”, “niosomes”, “transdermal systems”, “insulin”, “antidiabetic drugs” and “novel drug delivery systems”. Single inclusion was made for one article. If in vivo study was not done then article was seldom included in the manuscript. Results: The curiosity to develop NDDSs of antidiabetic drugs with special attention to the nanoparticulate system followed by microparticulate and lipid-based system is found to emerge gradually to overcome the problems associated with the conventional dosage forms and to win the confidence of end users towards the higher acceptability. Conclusion: In the current scientific panorama when the area of novel drug delivery system has been recognized for its palpable benefits, unique potential of providing physical stability, sustained and site-specific drug delivery for a scheduled period of time can open new vistas for precise, safe and quality treatment of DM.