Biocompatible crosslinked polymers

A method for preparing a biocompatible crosslinked polymer hydrogel, comprising:

• combining a biocompatible small molecule crosslinker having at least two first functional groups and a molecular weight of 2000 or less with a synthetic biocompatible functional polymer having at least two second functional groups and having a molecular weight at least about 7 times more than the small molecule crosslinker wherein each of the first functional groups are different than each of the second functional groups and the first and the second functional groups are chosen from the group consisting of electrophiles and nucleophiles, such that the combination of the first and second functional groups results in the formation of the biocompatible crosslinked polymer hydrogel.

A biocompatible crosslinked polymer hydrogel, comprising:

• at least one biocompatible crosslinker region consisting essentially of a crosslinked synthetic crosslinker molecule with a pre-crosslinked molecular weight of less than 2000;
• at least one biocompatible functional polymer region consisting essentially of a crosslinked synthetic polymer molecule with a pre-crosslinked molecular weight of more than about 7 times the molecular weight of the pre-crosslinked crosslinker molecule,
• wherein the biocompatible crosslinked polymer comprises at least three links between the crosslinker region and the functional polymer region, and the links are a reaction product of at least one electrophilic functional group with of at least one nucleophilic functional group that react to form the hydrogel.