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

• Published in: Advanced healthcare materials Vol. 12; no. 32; pp. e2302078 - n/a
• Main Authors: Paul, Sattwikesh, Schrobback, Karsten, Tran, Phong Anh, Meinert, Christoph, Davern, Jordan William, Weekes, Angus, Klein, Travis Jacob
• Format: Journal Article
• Language: English
• Published: Germany 01.12.2023
• Subjects: Adhesives; Animals; bioadhesive; Cartilage; Cattle; Chitosan - pharmacology; Gelatin; GelMA; glycol chitosan; hydrogels; Hydrogels - pharmacology; Tissue Engineering; visible light; glycol chitosan; GelMA; hydrogels; visible light; bioadhesive; cartilage
• ISSN: 2192-2640; 2192-2659
• DOI: 10.1002/adhm.202302078

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, hydrogels that are injectable, cytocompatible, mechanically robust, and highly adhesive to cartilage are developed. This approach uses GelMA‐glycol chitosan (GelMA‐GC) that is crosslinkable with visible light and photoinitiators (lithium acylphosphinate 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 ≈100 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. Bioadhesive hydrogels for cartilage are developed that are injectable, cytocompatible, and mechanically robust, based on gelatin methacryloyl‐glycol chitosan (GelMA‐GC) with ruthenium/sodium persulfate for photocross‐linking. Tensile and push‐out tests of the hydrogels demonstrate adhesive strength of ∼100 kPa and 46 kPa, respectively. After injection in bovine cartilage defects and in situ cross‐linking, the hydrogel remains intact and integrated with cartilage following joint manipulation ex vivo.