Synthesis and Characterizations of In Situ Cross-Linkable Gelatin and 4-Arm-PPO-PEO Hybrid Hydrogels via Enzymatic Reaction for Tissue Regenerative Medicine

Abstract

In situ cross-linkable hybrid hydrogels composed of gelatin and 4-arm-polypropylene oxide−polyethylene oxide (Tetronic) was developed as an injectable scaffold for tissue regeneration. The gelatin was modified by hydroxyphenyl propionic acid (HPA) and the Tetronic was conjugated with tyramines (Tet−TA). The hydrogels were rapidly formed by mixing the polymer solutions containing horseradish peroxidase (HRP) and hydrogen peroxide (H 2 O 2 ). The gelation time and mechanical properties of the hydrogels could be controlled by varying the HRP and H 2 O 2 concentrations. In vitro degradation study of the hybrid hydrogels was carried out using collagenase and the prolonged proteolytic degradation was obtained due to the presence of the Tetronic. Human dermal fibroblast (hDFB) was cultured in the hydrogel matrices to evaluate the cyto-compatibility. The encapsulated cells were shown to be highly viable and spread over the gel matrices, suggesting that the hybrid hydrogels have an excellent cyto-compatibility. The hydrogels were also subcutaneously injected in the back of mice and the results demonstrated that the hydrogels were rapidly formed at the injected site. From these results, we demonstrate that the in situ cross-linkable hydrogels formed by hybridization of gelatin and Tetronic via enzyme-mediated reactions hold great promise for use as injectable matrices for tissue regenerative medicine due to their tunable physico-chemical properties and excellent bioactivity.

A Versatile Biosynthetic Hydrogel Platform for Engineering of Tissue Analogues

“…However, the ratio might be further fine‐tuned toward a 1:1 Gln:Lys molar ratio, to match the degradation of the hydrogel with the speed of matrix deposition of a specific tissue type of interest. In fact, it was shown previously that degradation of hybrid hydrogels can be further slowed down by the addition of a synthetic polymer . While for vasculogenic and osteogenic cocultures, gelPEG hydrogels roughly retained their initial volume over culture time, this was not the case for Matrigel‐based cocultures.…”

Platelet‐rich plasma loaded in situ‐formed hydrogel enhances hyaline cartilage regeneration by CB1 upregulation

“…In this enzymatically cross‐linking reaction, the phenol groups of the polymer were covalently conjugated to each other through carbon‐carbon and carbon‐oxygen bonds. The detailed mechanism of the reaction was demonstrated in our previous studies 20, 27, 28…”

Mineralized gelatin methacrylate-based matrices induce osteogenic differentiation of human induced pluripotent stem cells

“…All matrices were dried at 37 °C for 24 hours and their dry weights (W d0 ) were measured. The dried matrices were equilibrated in PBS and incubated in 1.5 mL of 0.02 w/v% collagenase type II (Worthington Biochemical, catalog number: LS004177) in PBS at 37 °C [22]. The matrices incubated in 1.5 mL of PBS under identical experimental conditions were used to examine hydrolytic degradation.…”