Synthesis, Characteristic And Its Release Properties In Vitro Of Thermosensitive Intelligent Materials Based On Poly(N-Isopropylacrylamide)-b-Oligo(Meth-YL Methacrylate)

Poly(N-isopropylacrylamide),oligo(methyl methacrylate)were synthesized and the copolymer PNIPAAm-b-OMMA was synthesized via polycondensation of two homopolymers in 1,4-dioxane.PNIPAAm-b-OMMA was a kind of novel temperature sensitive biomaterials and its properties as drug carrier were also studied in this paper.The products were characterized by FT-IR and ~1H NMR spectra and TEM.The PNIPAAm-b-OMMA copolymer micelles in aqueous solution presented the same lower critical solution temperature(LCST)as the unmodified PNIPAAm,owing to formation of a core-shell micellar structure shielding the hydrophobic inner OMMA core from interacting with water. Moreover,the micelles showed reversible temperature-responsive aggregation/dispersion in responsive to temperature cycles through the LCST. By using this property,the copolymer was used as drug carrier and its release behavior was also studied.The micelle carriers exhibited two heterogeneous microdomains:a hydrophobic inner core capable of highly solubilizing hydrophobic prednisolone molecules,plus a hydrated outer shell that stabilized this micellar structure below its LCST.By using the anti-inflammation drug prednisolone as model drug,it was found that the PNIPAAm-b-OMMA drug carrier could prolong the release time,and control the release amount by changing the temperature.Accordingly,this copolymer micelle may provide as an effective drug carrier for drug control and release.