Dynamic hyaluronic acid hydrogel with covalent linked gelatin as an anti-oxidative bioink for cartilage tissue engineering

Abstract

Cartilage tissue engineering has arisen as a promising therapeutic option for degenerative joint diseases, such as osteoarthritis, in the hope of restoring the structure and physiological functions. Hydrogels are promising biomaterials for developing engineered constructs for cartilage regeneration. However, such cell-laden constructs could be exposed to elevated levels of reactive oxygen species (ROS) in the inflammatory microenvironment after being implanted into injured joints, which may affect their phenotype and normal functions and thereby hinder the regeneration efficacy. To attenuate ROS induced side effects, a multifunctional hydrogel with an innate anti-oxidative ability was produced in this study. The hydrogel was rapidly formed through a dynamic covalent bond between phenylboronic acid grafted hyaluronic acid (HA-PBA) and poly (vinyl alcohol) (PVA) and was further stabilized through a secondary crosslinking between the acrylate moiety on HA-PBA and the free thiol group from thiolated gelatin. The hydrogel is cyto-compatible and injectable and can be used as a bioink for 3D bioprinting. The viscoelastic properties of the hydrogels could be modulated through the hydrogel precursor concentration. The presence of dynamic covalent linkages contributed to its shear-thinning property and thus good printability of the hydrogel, resulting in the fabrication of a porous grid construct and a meniscus like scaffold at high structural fidelity. The bioprinted hydrogel promoted cell adhesion and chondrogenic differentiation of encapsulated rabbit adipose derived mesenchymal stem cells. Meanwhile, the hydrogel supported robust deposition of extracellular matrix components, including glycosaminoglycans and type II collagen, by embedded mouse chondrocytes in vitro. Most importantly, the hydrogel could protect encapsulated chondrocytes from ROS induced downregulation of cartilage-specific anabolic genes (ACAN and COL2) and upregulation of a catabolic gene (MMP13) after incubation with H2O2. Furthermore, intra-articular injection of the hydrogel in mice revealed adequate stability and good biocompatibility in vivo. These results demonstrate that this hydrogel can be used as a novel bioink for the generation of 3D bioprinted constructs with anti-ROS ability to potentially enhance cartilage tissue regeneration in a chronic inflammatory and elevated ROS microenvironment.

Advanced injectable hydrogels for cartilage tissue engineering

“…Shi’s team researched and prepared an injectable hydrogel with natural antioxidant capacity. A dynamic covalent bond between PVA and phenylboronic acid grafted to HA-PBA forms hydrogels, which are further stabilized by secondary cross-linking between the acrylate portion of the HA-PBA and the free sulfhydryl group in the vulcanized gelatin ( Shi et al, 2021b ). The existence of a dynamic covalent bond contributes to the shear thinning of hydrogels, which makes hydrogels have suitable printing.…”

Engineering Hyaluronic Acid for the Development of New Treatment Strategies for Osteoarthritis

“…Constructs implanted into the osteochondral defects of rats with medial meniscectomy-induced OA could successfully induce tissue repair while attenuating a joint inflammatory response. HA-based bioinks can be further modified to provide additional therapeutic benefits for applications in degenerative joint diseases while supporting the viability of encapsulated cells [ 115 ]. For instance, bioink that consists of HA modified with phenylboronic acid and gelatin demonstrated inherent antioxidant properties by boronate ester bonds [ 115 ].…”

“…HA-based bioinks can be further modified to provide additional therapeutic benefits for applications in degenerative joint diseases while supporting the viability of encapsulated cells [ 115 ]. For instance, bioink that consists of HA modified with phenylboronic acid and gelatin demonstrated inherent antioxidant properties by boronate ester bonds [ 115 ]. The bioink effectively scavenged H 2 O 2 and supported the viability of encapsulated chondrocytes.…”

Characteristic and Chondrogenic Differentiation Analysis of Hybrid Hydrogels Comprised of Hyaluronic Acid Methacryloyl (HAMA), Gelatin Methacryloyl (GelMA), and the Acrylate-Functionalized Nano-Silica Crosslinker

“…However, the development of a hybrid HAMA-GelMA (HG) hydrogel that incorporates several crosslinkers has emerged as a promising strategy for optimizing the physical and mechanical properties of the hydrogel so to make it suitable for cartilage regeneration or other biological applications [ 19 , 20 ]. For example, Shi et al [ 21 ] showed this HG hydrogel through a dynamic covalent bond between phenylboronic acid-grafted hyaluronic acid (HA-PBA) and poly(vinyl alcohol), which was further stabilized through a secondary crosslinking between the acrylate moiety on the HA-PBA and the free thiol group from the thiolated gelatin with the antireactive oxygen species’ potential ability to enhance cartilage tissue regeneration. In addition, interest in free radical photopolymerization with a photoinitiator (P.I.)…”