The preparation of phosphorylcholine-containing poly(L-lactide) nanoparticles with solvent evaporation method

Phosphorylcholine-containing poly(L-lactide) (PLLA-PC) is a kind of amphiphilic copolymer synthesized with L-lactide (LLA) as monomer and glycerophosphorylcholine as ring-opening reagent. In this paper, self-assembly nanoparticles of PLLA-PC were prepared with solvent evaporation method. The factors that affected the properties and stability of nanoparticles were investigated. Transmission electron microscope (TEM) indicated that PLLA-PC nanoparticles presented typical core/shell structure. The critical micelle concentration (CMC) was determined with fluorescent probe method. The results showed that the CMCs were quite low (< 1 x 10(-3) g/l) and were dependent on LLA units in the copolymer. The size of the nanoparticles was detected by dynamic light scattering (DLS). The results indicated that the size could be affected by LLA units, the amount of solvent and water in the preparation process. On the other hand, the obtained nanoparticles were stable while being stored at 4 C-0, and hardly changed over the dilution with water, which was of great importance in venous injection. The solubility of clofazimine was better in aqueous solution of PLLA-PC nanoparticles than in pure water. This preliminary study suggested that PLLA-PC nanoparticles had a great potential as delivery system for hydrophobic drug.