Photo‐Cross‐Linkable, Injectable, and Highly Adhesive GelMA‐Glycol Chitosan Hydrogels for Cartilage Repair

Abstract

Hydrogels provide a promising platform for cartilage repair and regeneration. Although hydrogels have shown some efficacy, they still have shortcomings including poor mechanical properties and suboptimal integration with surrounding cartilage. Herein, we develop hydrogels that are injectable, cytocompatible, mechanically robust, and highly adhesive to cartilage. Our approach uses GelMA‐glycol chitosan (GelMA‐GC) that is crosslinkable with visible light and photo‐initiators (lithium acylphosphinate (LAP) and tris (2,2′‐bipyridyl) dichlororuthenium (II) hexahydrate ([RuII(bpy)3]2+ and sodium persulfate (Ru/SPS)). Ru/SPS‐cross‐linked hydrogels have higher compressive and tensile modulus, and most prominently higher adhesive strength with cartilage, which also depends on inclusion of GC. Tensile and push‐out tests of the Ru/SPS‐cross‐linked GelMA‐GC hydrogels demonstrate adhesive strength of approximately 100 kPa and 46 kPa, respectively. Hydrogel precursor solutions behave in a Newtonian manner and are injectable. After injection in focal bovine cartilage defects and in situ cross‐linking, this hydrogel system remains intact and integrated with cartilage following joint manipulation ex vivo. Cells remain viable (> 85%) in the hydrogel system, and further show tissue regeneration potential after three weeks of in vitro culture. These preliminary results provide further motivation for future research on bioadhesive hydrogels for cartilage repair and regeneration.This article is protected by copyright. All rights reserved

3D Bioprinted Xanthan Hydrogels with Dual Antioxidant and Chondrogenic Functions for Post-traumatic Cartilage Regeneration

“…The stress−strain curve of XGMA (H) approaches a straight line in the range of 10%−20% strain in Figure S6A, so we can obtain elastic modulus of XGMA (H) by calculating the slope of the curve in this interval. As shown in Figure S6B, the compressive modulus of XGMA (H) is 27 ± 3 KPa in the 10% to 20% strain range, which is promising for the maintenance of chondrocyte phenotype, re-differentiation, GAG, and collagen II accumulation according to a previous study. , …”

“…As shown in Figure S6B, the compressive modulus of XGMA (H) is 27 ± 3 KPa in the 10% to 20% strain range, which is promising for the maintenance of chondrocyte phenotype, re-differentiation, GAG, and collagen II accumulation according to a previous study. 31,32 The rheological behavior of the hydrogels was evaluated in three modes: angular frequency variation, oscillatory strain, and temperature sweep. In general, the elastic properties of the hydrogels were dominant, characterized by a storage modulus (G′) higher than the loss modulus (G′′).…”

Advances in Stimuli‐Responsive Chitosan Hydrogels for Drug Delivery Systems

“…[49] In this case, the primary mode of chemical cross-linking in chitosan-based hydrogels involves the formation of amide bonds. [50][51][52] Xu et al investigated the mucoadhesive capacity of the catechol functional groups by utilizing genipin to construct a crosslinking structure between catechol and chitosan. [17] With the help of NHs/EDC reaction, an amide bond is formed between the amino group of chitosan and the carboxyl group of graphene oxide, producing a hydrogel to serve as a skin wound dressing.…”