POLY(D, L- LACTIDE) NANOPARTICLES CONTAINING PROTEIN I. PREPARATION AND CHARACTERIZATION

Abstract

For several years, large molecules such as peptides and proteins are not considered feasible candidates for controlled release systems since the physicochemical and biological properties of peptide and protein are different from those of conventional drugs. Therefore, specific delivery device for peptides and proteins needs to be developed. Previous literatures showed some advantages of polymeric nano- and micro-particles for the delivery of peptides and proteins to the systemic circulation and to immune system. The latest works further revealed the advantages of the nanoparticles over the microparticles. In this paper, we are reporting fabrication of poly (D, L- lactide) nanoparticles containing BSA protein by an improved double-emulsion (water-in-oil-in-water) solvent evaporation /extraction technique. The BSA-loaded PDLLA nanoparticles are characterized in terms of size, zeta potential, morphology and BSA-loaded encapsulation efficiency, using various analytical techniques such as HR-TEM, laser light scattering method, FT-IR and micro-BCA assay. Results show that the encapsulation efficiency is 53.3%, particle size about 350 nm and zeta potential –48.18 mv. IR spectra suggest the absence of strong chemical interactions between BSA and PDLLA and the physicochemical integrity of BSA is retained within the nanoparticles. The current study suggests that the PDLLA nanoparticles could be an effective carrier for protein and peptide delivery. Based on the results above, we are expecting to construct a preparation fundamental for sensitive bio-macromolecules nano-delivery system.