Synthesis and Thermosensitive Characterization of DTPA-Poly(N-isopropylacrylamide)

The thermosensitive poly(N-isopropylacrylamide)(PNIPAAm) aqueous solutions behave the low critical solution temperature(LCST) and could be used as drug delivery system.A novel drug delivery system based on PNIPAAm with isotopically labellable end groups DTPA has been designed and synthesized by reaction of 4,4′-azobis(4-cyanopentanoic acid),N-isopropylacrylamide,diethylenetriaminepentaacetic dianhydride and ethylenediamine.DSC measurements indicated DTPA-PNIPAAm showed similar LCST to that of PNIPAAm.DTPA-PNIPAAm enabled the delivery of therapeutic nuclides by PNIPAAm.