Preparation of PNIPAM-g-P (NIPAM-co-St) microspheres and their blood compatibility.

The poly(N-isopropylacrylamide)-g-poly(N-isopropylacrylamide-co-styrene) microspheres (PNNS-MSs) were prepared by an emulsifier-free emulsion polymerization method. The blood compatibility of PNNS-MSs was characterized by in vitro for coagulation tests, hemolysis assay, plasma recalcification time, complement activation, platelet activation, and cytotoxicity experiments. The results showed that the PNNS-MSs have good blood compatibility and lack cytotoxicity, which may be attributed to the formation of a strong interfacial hydration layer that result from amphiphilic molecular structure of the PNIPAM shell and minimal interaction between PNNS-MSs interfaces and blood components. The PNNS-MSs provide a promising platform of blood circulation system for early illness diagnosis and therapy.