Injectable, covalently in situ forming hydrogels based on poly (N-isopropylacrylamide) have been designed on the basis of mixing hydrazide-functionalized nucleophilic precursor polymers with electrophilic precursor polymers functionalized with a combination of ketone (slow reacting) and aldehyde (fast reacting) functional groups. By tuning the ratio of aldehyde: ketone functional groups as well as the total number of ketone groups in the ...