Hydrogels have found wide applications in biomedical field because of their good biocompatibility and stimuli-responsivity

however

some drawbacks

such as weak mechanical strength

slow response rate and lack of biodegradability

still need to be resolved. In recent years

we designed a series of biomaterials

mainly based on the thermosensitive poly(N-isopropylacrylamide) (PNIPAM) microgels

to be used as drug carriers

biosensors and cell scaffolds. The major problem we aimed to resolve is the slow response of the hydrogel biomaterials. We have designed and prepared PNIPAM microgels with good glucose-sensitivity

which were used for self-regulated insulin release. We proposed a new polymerized crystalline colloidal array optical sensing method and developed several optical biosensors which can respond quickly. We also achieved the in situ gelation of concentrated PNIPAM microgel dispersions

which were further developed as a new injectable 3D cell scaffold. Also based on the reversibility of this system

we proposed a new method for the fabrication of multicellular spheroids

which have important applications in drug screening

cancer study and tissue engineering.