MICROSTRUCTURED HYDROGELS WITH MODULATED TRANSITIONTEMPERATURE FOR POSITIVE CONTROL RELEASE

摘要

In this work we prepared microgels of N-isopropylacrylamide (NIPAAm) with theswollen-unswollen temperature transition modulated above the body temperature (37 °C),by copolymerization with acrylamide or N,N-dimethylacrylamide. The microgels wereused to produce microstructured hydrogels of NIPAAm, also with the temperaturemodulated with the comonomers. We found that the microstructured hydrogels present fasttemperature response when temperature is changed from 37 °C to 42 °C. The shrinkingswellingprocess was reversible when the temperature was cycled between the twotemperatures. However, since the temperature induced transition of the hydrogels wascontinuous, the change in degree of swelling between the two temperatures was smallerthan the change between 25°C and 42°C. Solute release studies shows fast release ofvitamin B12 without temperature control, but temperature controlled release of cytochrome C.