Polymeric lamellar substrate particles for intranasal vaccination

In recent years, several strategies have been under investigation to achiev e safe and effective immunisation, in terms of new antigens, adjuvants and routes of vaccination. The latter include mucosal sites such as oral, recta l, vaginal and nasal. Biodegradable microparticles produced from polymers s uch as poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) co ntaining encapsulated vaccine antigens have been extensively studied for im munisation. These microparticles allow controlled release of vaccines with the aim to develop as single dose vaccines. However there are concerns rega rding the integrity and immunogenicity of the antigen during the encapsulat ion process when the antigen is exposed to organic solvents, high shear str esses and the exposure of antigen to low pH which is caused by polymer degr adation. Polymeric lamellar substrate particles (PLSP) produced by simple p recipitation of PLA, form a novel polymeric system for the adsorption of an tigens. This procedure avoids PH changes, exposure to organic solvents and hence allows the integrity of the antigen to be retained. The aim of this a rticle is to discuss the factors affecting the characteristics of PLSP and adsorption of antigens onto PLSP and consider their potential as adjuvants for the nasal delivery of protein, peptide or viral vaccines. (C) 2001 Else vier Science B.V. All rights reserved.