Keywords: entrapped efficiency, microencapsulation, drug delivery systems, PLA, poly(lactic acid), PLGA microspheres, poly(DL–lactide–co–glycolide), PLL, poly–L–lysine, CTAB, cetyltrimethylammonium, PEI, polyethyleneimine, antigen delivery systems, polymeric microspheres, nanotechnology, antigen binding
The preparation and characteristic of poly(lactide co–glycolide) microspheres as novel antigen delivery systems
Polymeric microspheres with encapsulated antigens or medicine have become well established in the last decade as potent delivery systems. Our novel PLGA microspheres were prepared using a w/o/w solvent evaporation process in the presence of the anionic surfactants, including poly–L–lysine (PLL), cetyltrimethylammonium (CTAB), polyethyleneimine (PEI). High lamellae incorporation efficiency (97%), protein–adsorbed on PLA lamellae capacity (240 μg/mg), efficiency (93%) and encapsulated by PLGA formatted microspheres yield rate (77%) are successfully produced. The PEI modified PLA lamellae (240.2, 20) have more significantly increased proteins loading capacity (μg/mg) and in vitro 50% amount release time (day) than CTAB–modified (83.8, 0.5), PLL–modified (26.0, 0.5), and unmodified lamellae (10.1, 0.3), respectively. Also the sustained release effect over four weeks of FTIR–OVA microspheres was obtained by PEI modified PLA lamellae. In vitro release profiles show more active protein sustain release from PEI modified PLA lamellae than OVA–PLA only microspheres. Antigen binding to the charged PLGA microspheres was influenced by both electrostatic interaction and by other mechanisms, including hydrophobic interactions.