Nanoparticles of biocompatible and biodegradable polymers such as poly-lactic-co-glycolic acid (PLGA) are widely used as drug delivery systems for the administration of biomolecules like proteins. The purpose of this work is to validate a novel formulation method by a phase separation phenomenon using the non-toxic solvent glycofurol (GF) in order to encapsulate proteins into PLGA nanoparticles. Nanoprecipitates of a model protein (lysozyme) and a therapeutic protein (TGF-β1) were formed to ensure their stability upon subsequent encapsulation in PLGA nanoparticles.
Good encapsulation efficiency was obtained with preservation of the structure integrity and protein bioactivity after encapsulation. PLGA nanoparticles were then characterized in terms of size, zeta potential and morphology. Moreover, residual solvent was quantified and in vitro release study of the encapsulated proteins was performed to demonstrate the efficacy of our encapsulation method in drug sustained release. Finally, cytocompatibility study of nanoparticles was performed. Thus, we developed an effective method based on the preliminary step of protein precipitation for the formulation of PLGA nanoparticles as protein carriers for biomedical applications.