Biodegradable Nanoparticles Made of Amino-Acid-Based Ester Polymers: Preparation, Characterization, and in Vitro Biocompatibility Study

A systematic study of fabricating nanoparticles (NPs) by cost-effective polymer deposition/solvent displacement (nanoprecipitation) method has been carried out. Five amino acid based biodegradable (AABB) ester polymers (four neutral and one cationic), four organic solvents miscible with water, and eight surfactants were tested for the fabrication of the goal NPs. Depending on the nature of the AABB polymers, organic solvents and surfactants, as well as on the fabrication conditions, the size (Mean Particle Diameter) of the NPs could be tuned within 42 ÷ 398 nm, the zeta-potential within 12.5 ÷ +28 mV. The stability (resuspendability) of the NPs upon storage (at room temperature and refrigerated) was tested as well. In Vitro biocompatibility study of the NPs was performed with four different stable cell lines: A549, HeLa (human); RAW264.7, Hepa 1-6 (murine). Comparing the NPs parameters, their stability upon storage, and the data of biological examinations the best were found: As the AABB polymer, a poly(ester amide) composed of l-leucine, 1,6-hexanediol and sebacic acid–8L6, as a solvent (organic phase—DMSO), and as a surfactant, Tween 20.