Biodegradable Polymers (PLA and PLGA) Based Nanoparticles in Protein and Plasmid DNA Delivery

Abstract

The biodegradable polymers like poly lactic acid (PLA) and poly (lactide-co-glycolic acid) (PLGA) are considered as the „green‟ eco-friendly materials due their biocompatibility and non-toxic properties. Biodegradable microspheres and nanoparticles have proven to be very useful in protein and DNA delivery systems. These are easily taken up by immunocompetent cells, shows prolonged antigen release characteristics and provide a long lasting immunity. Micro and nano-particulate based protein and DNA delivery systems have its importance for various therapeutic and biomedical applications. PLA and PLGA microparticles and nanoparticles were formulated by double solvent emulsion evaporation (w/o/w) method and characterised for their surface morphology, size, loading efficiency and release profile study. The microsphere and nanosphere morphology were examined by SEM and Zeta sizer. It was found that PLA encapsulated with BSA (2.5%) showed loading efficiency more than 82% and that with plasmid DNA (Concentration: 1mg/ml), it was found to be 41%. It was also found that the particle size for PLA was varying between 162-373 nm. Similarly for PLGA particles when encapsulated with BSA, the loading efficiency became 91% whereas for encapsulated plasmid DNA, the loading efficiency was 44%, with their respective particle size between 113-335 nm. In vitro release of BSA and plasmid DNA from encapsulated PLA and PLGA nanoparticles were checked spectrophotometrically with optical density 562 nm for protein and 260 nm in case of plasmid DNA, by taking samples at different time intervals dissolved in PBS (phosphate saline buffer, at pH 7.4).