Arvind K. Jain

Synthesis, characterization and evaluation of novel triblock copolymer based nanoparticles for vaccine delivery against hepatitis B

Poly lactic acid (PLA) is one of widely used biodegradable polymer in vaccine delivery. However, the use is restricted due to hydrophobic nature and generation of acidic microenvironment upon its degradation, rendering it unfavorable to the encapsulated antigen. In the present study we have synthesized PEG derivatized block copolymers of PLA for development of nanoparticles encapsulating HBsAg for mucosal vaccination against hepatitis B. The copolymers of compositions AB, ABA and BAB (PLA as A-block and PEG as B-block) were synthesized and characterized by 1H NMR spectroscopy and gel permeation chromatography. Nanoparticles were characterized to determine the effect of copolymer. Among all, BAB produced nanoparticles of smallest size and lowest zeta potential, suggesting highest PEG density on their surface. The in vitro release experiments were performed in PBS (pH7.4). SDS-PAGE analysis confirmed the structural stability and integrity of the released antigen. Results were compared for immunogenicity with plain PLA nanoparticles and conventional alum-HBsAg based vaccine. BAB nanoparticles produced better humoral response as compared to other polymeric nanoparticles. The extent of humoral response obtained in single dose of BAB nanoparticles was comparable to the response produced by alum based vaccine (which received a booster dose). Block copolymeric nanoparticles also produced better sIgA level at all local and distal mucosal sites as compare of PLA nanoparticles, where alum based formulation failed to give any considerable response. Additionally, IgG1 and IgG2a isotype were determined to confirm the T(H)1/T(H)2 mixed immune response. These data demonstrate the potential of BAB nanoparticles as mucosal vaccine delivery system capable of eliciting high and prolonged immune response.

Evaluation of mucoadhesive PLGA microparticles for nasal immunization.

In this study, hepatitis B surface antigen (HBsAg) loaded poly(lactic-co-glycolic acid) (PLGA) microparticles were prepared and coated with chitosan and trimethyl chitosan (TMC) to evaluate the effect of coating material for nasal vaccine delivery. The developed formulations were characterized for size, zeta potential, entrapment efficiency, and mucin adsorption ability. Plain PLGA microparticles demonstrated negative zeta potential. However, coated microparticles showed higher positive zeta potential. Results indicated that TMC microparticles demonstrated substantially higher mucin adsorption when compared to chitosan-coated microparticles and plain PLGA microparticles. The coated and uncoated microparticles showed deposition in nasal-associated lymphoid tissue under fluorescence microscopy. The coated and uncoated microparticles were then administered intranasally to mice. Immune-adjuvant effect was determined on the basis of specific antibody titer observed in serum and secretions using enzyme-linked immunosorbent assay. It was observed that coated particles showed a markedly increased anti-HBsAg titer as compared to plain PLGA microparticles, but the results were more pronounced with the TMC-coated PLGA microparticles.

Pharmaceutical and immunological evaluation of mucoadhesive nanoparticles based delivery system(s) administered Intranasally

Tri-methyl chitosan synthesis accompanies polymer chain scission, which may affect the carrier and adjuvant properties of the polymer. The main objective of this study was to synthesize the tri-methylated chitosan using mild (TMC-M) and conventional (TMC) method and compare their efficacy as nasal vaccine delivery vehicle. During in vitro studies TMC-M nanoparticles showed the lowest nasal clearance rate when compared with chitosan (CS) and TMC nanoparticles. The immunogenicity of nanoparticles based delivery system(s) was assessed by measuring anti-HBsAg antibody titer in mice serum and secretions after intranasal administration. The alum based HBsAg vaccine injected subcutaneously was used as positive control. Results indicated that alum based HBsAg induced strong humoral but negligible mucosal immunity. However, TMC-M nanoparticles induced stronger immune response at both of the fronts as compared to generated by CS or TMC nanoparticles. Present study demonstrates that TMC-M can be a better carrier adjuvant for nasal subunit vaccines.

Advances in Novel Drug Delivery Strategies for Breast Cancer Therapy

Abstract: Breast cancer remains one of the worlds most devastating diseases. However, better understanding of tumor biology and improved diagnostic devices could lead to improved therapeutic outcomes. Nanotechnology has the potential to revolutionize cancer diagnosis and therapy. Various nanocarriers have been introduced to improve the therapeutic efficacy of anticancer drugs, including liposomes, polymeric micelles, quantum dots, nanoparticles, and dendrimers. Recently, targeted drug delivery systems for anti-tumor drugs have demonstrated great potential to lower cytotoxicity and increase therapeutic effects. Various ligands/approaches have been explored for targeting breast cancer. This paper provides an overview of breast cancer, conventional therapy, potential of nanotechnology in management of breast cancer, and rational approaches for targeting breast cancer.

Electrosprayed inulin microparticles for microbiota triggered targeting of colon.

Inulin, a naturally occurring polysaccharide, was acetylated to make it processable by electrospraying, a facile and single step method for microparticle fabrication. Electrospraying process parameters were optimized for fabrication of spherical and monodisperse indomethacin (IDM) loaded inulin acetate (INA) microparticles. The apparent entrapment efficiency of IDM was determined to be 100%, whereas working encapsulation efficiency was estimated to be 35.39 ± 1.63%. Differential scanning calorimetry and X-ray diffraction analysis confirmed molecular dispersion of IDM in an amorphous state within the INA matrix. Finally, the results from in vitro release study performed in simulated gastro-intestinal fluids demonstrated that IDM was released only in simulated colonic fluid that contained inulinase. Therefore, this study demonstrates that acetylation of inulin does not alter its susceptibility to inulinase and that microparticles fabricated from INA can be developed as a colon targeting drug delivery system.

Development of a method to quantify the DNA content in cationic peptide-DNA nanoparticles.

Gene therapy has the potential to provide safe and targeted therapies for a variety of diseases. A range of intracellular gene delivery vehicles have been proposed for this purpose. Non-viral vectors are a particularly attractive option and among them cationic peptides have emerged as promising candidates. For the pharmaceutical formulation and application to clinical studies it is necessary to quantify the amount of pDNA condensed with the delivery system. There is a severe deficiency in this area, thus far no methods have been reported specifically for pDNA condensed with cationic peptide to form nanoparticles. The current study seeks to address this and describes the evaluation of a range of disruption agents to extract DNA from nanoparticles formed by condensation with cationic fusogenic peptides RALA and KALA. Only proteinase K exhibited efficient and reproducible results and compatibility with the PicoGreen reagent based quantification assay. Thus we report for the first time a simple and reliable method that can quantify the pDNA content in pDNA cationic peptide nanoparticles.

Evaluation of mucoadhesive carrier adjuvant: Toward an oral anthrax vaccine

Abstract The aim of present study was to evaluate the potential of mucoadhesive alginate-coated chitosan microparticles (A-CHMp) for oral vaccine against anthrax. The zeta potential of A-CHMp was − 29.7 mV, and alginate coating could prevent the burst release of antigen in simulated gastric fluid. The results indicated that A-CHMp was mucoadhesive in nature and transported it to the peyers patch upon oral delivery. The immunization studies indicated that A-CHMp resulted in the induction of potent systemic and mucosal immune responses, whereas alum-adjuvanted rPA could induce only systemic immune response. Thus, A-CHMp represents a promising acid carrier adjuvant for oral immunization against anthrax.

Development of polymeric–cationic peptide composite nanoparticles, a nanoparticle-in-nanoparticle system for controlled gene delivery

We report the formulation of novel composite nanoparticles that combine the high transfection efficiency of cationic peptide-DNA nanoparticles with the biocompatibility and prolonged delivery of polylactic acid–polyethylene glycol (PLA-PEG). The cationic cell-penetrating peptide RALA was used to condense DNA into nanoparticles that were encapsulated within a range of PLA-PEG copolymers. The composite nanoparticles produced exhibited excellent physicochemical properties including size <200 nm and encapsulation efficiency >80%. Images of the composite nanoparticles obtained with a new transmission electron microscopy staining method revealed the peptide-DNA nanoparticles within the PLA-PEG matrix. Varying the copolymers modulated the DNA release rate >6 weeks in vitro. The best formulation was selected and was able to transfect cells while maintaining viability. The effect of transferrin-appended composite nanoparticles was also studied. Thus, we have demonstrated the manufacture of composite nanoparticles for the controlled delivery of DNA.