Novel cross-linked polymers, their preparation and their use

While maintaining excellent properties such as biocompatibility and water solubility of PVLA, novel crosslinked polymers for making the gel, a manufacturing method thereof and use thereof. Formula I: In the N-p-vinylbenzyl -D- lactone amide represented, crosslinked polymer obtained by reacting PEG derivatives having respective reactive double bond to two or more ends, their preparation and their use.