Functional Hydrogels and Their Application in Drug Delivery, Biosensors, and Tissue Engineering

Table 1

Stimulating and responsive factors of smart hydrogels.

Type	Stimulating factors	Responsive group or substance
Temperature-sensitive	Temperature	N-Isopropylacrylamide
pH-sensitive	pH	-COOH, -HSO3, -NH2
Light-sensitive	Light	Cinnamoyl-, azobenzene, O-nitrobenzyl alcohol
Electricity-sensitive	Electricity	Carbonyl-, nitro-, alkyl group