Preparation of blood-compatible nanoparticles bearing phosphorylcholine group

The biodegradable poly (L-lactic acid) (PLA) nanoparticles covered with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer were prepared by the solvent evaporation technique with the amphiphilic water-soluble MPC polymer as the emulsifier. The diameter of the nanoparticles was approximately 200 nm, which was determined by atomic force microscopy and dynamic light scattering. X-ray photoelectron spectroscopy analysis indicated that the surface of the nanoparticles was fully covered with the MPC polymer. The amount of plasma protein bovine serum albumin adsorbed on the nanoparticles coated with the MPC polymer was significantly smaller compared with that on the polystyrene nanoparticles. The PLA nanoparticles coated with the MPC polymer is suggested to be a safer drug carrier in the bloodstream. One of the anticancer drugs, adriamycin (ADR), could be adsorbed on the nanoparticles through a hydrophobic interaction. Even when the nanoparticles were stored in PBS for 5 days, 40 % of the ADR still remained on the surface. We concluded that the nanoparticles coated with the MPC polymer are useful as a novel adsorption-type drug carrier, which could be applied through the bloodstream.