Srinath Balkundhi

Sanjay Ghodawat University, India

Title: Advances in Polymeric Particle Vaccine Formulations

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Biography

Srinath Balkundhi  has completed his PhD in Pharmaceutical Sciences  by JNTUA University and Mentor for postdoctorate scholar. He is working as professor in Pharmaceutics and Dean, School of Pharmaceutical Sciences Sanjay Ghodawat University Kolhapur Maharashtra, India. He has published more than 25 papers in reputed journals and presented papers in National and International conferences.

Abstract

The increasing cost of modern health care that relies heavily on the direct treatment of on-going disease, is leading to a need to reappraise current medical practice. It is becoming highly desirable to place more emphasis on preventive medicine. An attractive and highly cost-effective preventive approach is the use of vaccines.

Vaccines are chemical substances prepared from the proteins (antigen) of other mo/ animal cells which confer immunity to a particular virus, bacteria etc.Some of the vaccines are also synthesized biologically through genetic engineering techniques. New advances in immunology, molecular biology, and biotechnology allow us now to realistically approach diseases for which vaccines were previously unfeasible. The advances have already led to the improvement of existing vaccines, developing safer acellular vaccines and some vaccines may prevent or stop the development of cancers and there is a real potential for preventive and therapeutic vaccination against tumors, auto-immune and allergic diseases. The development of new technologies has allowed scientists in exploiting and improving the formulation, immunogenicity, efficacy, safety and delivery of vaccines. 

Improved and novel strategies involved in the development and designing of new generation vaccines like purified macromolecule, polymeric presentation of peptides, Synthetic peptide, and rDNA vaccines are few such types.

The polymeric presentation of peptide is a viable approach which improves the immunogenicity of multidose vaccine injection and synthetic peptides significantly. The novel polymeric particulate systems presently studied for delivery of antigen/peptide vaccines include liposomes, emulsions, ISCOMS, microspheres and nanoparticles. Most of the time these polymeric formulations entrapping proteins elicit immune responses. It is essential that the particles should entrap immunoreactive antigens and release of antigen should mimic the conventional vaccination schedule thus providing in vivo auto boosting to elicit desired antibody response. Apart from this, it is also desirable that antigens released from polymer particles are immunogenic. This is most important as polymer particles release soluble antigen and it is widely documented that soluble antigens are weak immunogen. Thus with proper formulation of polymer loaded particle it will be possible to generate cellular immune response which is in general difficult to generate with exogenous antigen.

Parameters which influences the entrapment, invitro release and immunogenicity of some vaccines were extensively studied in Wistar rats model. Optimization of particle formulation parameters in terms of size, loading, in vitro release characteristics and use of additional adjuvant during immunization resulted in generation of long lasting immune response from single point immunization. Intracellular uptake and immune response studies have provided evidence that nanoparticles can be selectively used to generate cellular immune response where as humoral response is predominantly generated by larger sized particles.

Nanoparticles based on polylactide, co-glycolide (PLGA, PLA) have gained much attention as carriers for antigens. Impressive results have been attained for both humoral and cell mediated effects. The incorporation of antigens into biodegradable micro/nano particles has several advantages including the protection of antigen from proteolysis and possible co-incorporation of immunological adjuvants that may further enhance the immune response.