Fabrication of a Controlled in Situ Forming Polypeptide Hydrogel with a Good Biological Compatibility and Shapeable Property.

A hydrogel is required to have a good biocompatibility, permeability for nutrients, and an easy construction procedure for biomedical applications. In particular, in situ forming hydrogels (ISFHs) have triggered considerable interest in their facile preparation methods. Here, an enzyme-prompted ISF, biodegradable poly(l-lysine)-graft-4-hydroxyphenylacetic acid (PLL-g-HPA) hydrogel in the conditions of horseradish peroxidase (HRP) and hydrogen peroxide (H 2 O 2 ) and with a good biocompatibility was developed. The gelling time varied from a couple of seconds to several minutes depending on the amounts of catalyst, H 2 O 2 , and polymer. Due to the conveniently ISF means, the fabricated hydrogel could be applied in any form according to the need. The hydrogels display a good biological compatibility, as demonstrated in vitro cell culture and attachment experiments. Besides, the remaining NH 2 groups in the hydrogel could be further functionalized for various cell research and bioapplications.