Biomimetic Polymer Nanoparticles Embedding Quantum Dots

To develop new functional fluorescence probe based on semiconductor nanoparticles, such as quantum dots (QD)s, we investigated polymer particle embedding QDs and covered with artificial cell membrane-biointerface. These nanoparticles were prepared by assembling 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer as a platform and biomolecules immobilized on the surface of the nanoparticles. The fluorescence property of QDs remained after embedding in the polymer nanoparticles. The MPC polymer surface showed high resistance to non-specific cellular uptake due to the phosphorylcholine groups in the side chain. On the other hand, when cell-penetration oligopeptide, octaarginine was immobilized on the surface, they could permeate the membrane of cells effectively and good fluorescence based on QDs could be observed. Cytotoxicity and inflammation reaction was not produced by these nanoparticles even after immobilization of octapeptide. In conclusion, we could obtain stable fluorescence polymer nanoparticles covered with artificial cell membrane, which are useful as an excellent bioimaging probe and as a novel evaluation tool for biomolecular function in the target cells.