The aim of the present study was designing a novel drug carrier system composed of the block copolymer PBLA-POLO-PBLA via ring-opening polymerization of the β-benzyl-Lasparate N-carboxyanhydride (BLA-NCA) monomer which was initiated by poloxamer 188. The polymers were characterized and confirmed by 1H-NMR, Fourier transform infrared assay (FTIR) and gel permeation chromatography (GPC). Then, studying with A549 cells to evaluate the material`s cytotoxicity showed that the copolymer was nontoxic. PBLA-POLO-PBLA nanoparticles loaded with Valaciclovir (VACV) were prepared by the emulsion-solvent evaporation method, and the physicochemical properties were also investigated afterwards. The transmission electron microscope (TEM) showed that the VACV-loaded nanoparticles had a sub-micron size with a spherical shape. The VACV-loaded nanoparticles (with a loading efficiency of 4.36%) showed a sustained release of VACV molecules (with 70.22% release in 96 h) which was determined by HPLC at 251 nm. These results suggested that PBLA-POLO-PBLA block copolymer was a promising nano-carrier in nanoparticle drug delivery systems.
