Fluorine-containing thermo-sensitive microgels as carrier systems for biomacromolecules.

A series of microgels with nanometer diameter were prepared from 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFMA, FA for short) and N-isopropylacrylamide (NIPAAm). The composition and structure of microgels were studied by FTIR and (1)H NMR. The transmission electron microscope (TEM) results showed that the introduction of fluorine was very advantageous in improving the stability and monodisperity of NIPAAm microgel. The differential scanning calorimetry (DSC) and photon correlation spectroscopy (PCS) revealed that fluorinated NIPAAm microgels still displayed obvious temperature-responsiveness, and the lower critical solution temperature (LCST) of microgel particles decreased significantly. PCS tests also displayed the swelling and absorption behavior of microgels. Fluorescence spectrum showed that the microgel particles were able to combine with BSA, which would facilitate further development of fluorinated thermo-sensitive microgel in biomacromolecule carrier and delivery system.