In this study, a amphiphilic copolymer, poly ((N-isopropylacrylamide)-co-acrylamide-co- (octadecylacrylate)-co-(Falate-(polyethyleneglycol)-(acrylicacid)))(P(NIPA-co-AAm-co-ODA-co-FPA)) micelles was synthesized by free radical random copolymerization. The obtained amphiphilic copolymers were self-assembled into micelles, which exhibited thermally sensitivity. LCST of the micelles was detected by uv-vis spectrophotometer. The diameter and morphology of micelles were determined by laser particle size analyzer (LPSA) and transmittance electron microscope (TEM), respectively. The micelle with a diameter of 60 nm and LCST of 40 oC was obtained by utilizing of ODA and the feed ratio of NIPA and AAm, respectively, which is satisfied for drug delivery in living body. The maximum DLC was achieved with the amount of ODA (180mg).

Matriptase is a type II transmembrane serine protease highly expressed on the surface of tumor cells and participated in a range of human cancers including those of the breast, cervix, ovaries, prostate, colon and gastrointestinal tract. In this study, we developed a new matriptase detection probe with gold nanoparticles (AuNPs). A fluorescence dye was attached to AuNP surface through the bridge of peptide substrate (GRQSRAC). The fluorescence was quenched due to the fluorescence resonance energy transfer (FRET) between AuNP and the fluorescence dye. The fluorescence recovery properties were confirmed by dithiothreitol in vitro. The result of in vitro cell research indicates that the gold nanoparticle probe is sensitive and specificitive for the detection of matriptase expression in early tumor and has great potential in biomedical application.