Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

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.

Original publication




Journal article


J Control Release

Publication Date





161 - 169


Animals, Drug Delivery Systems, Female, Hepatitis B, Hepatitis B Vaccines, Lactic Acid, Mice, Mice, Inbred BALB C, Nanoparticles, Polyesters, Polymers