Osteochondral Regeneration with 3D‐Printed Biodegradable High‐Strength Supramolecular Polymer Reinforced‐Gelatin Hydrogel Scaffolds

Abstract

Biomacromolecules with poor mechanical properties cannot satisfy the stringent requirement for load‐bearing as bioscaffolds. Herein, a biodegradable high‐strength supramolecular polymer strengthened hydrogel composed of cleavable poly( N ‐acryloyl 2‐glycine) (PACG) and methacrylated gelatin (GelMA) (PACG‐GelMA) is successfully constructed by photo‐initiated polymerization. Introducing hydrogen bond‐strengthened PACG contributes to a significant increase in the mechanical strengths of gelatin hydrogel with a high tensile strength (up to 1.1 MPa), outstanding compressive strength (up to 12.4 MPa), large Young's modulus (up to 320 kPa), and high compression modulus (up to 837 kPa). In turn, the GelMA chemical crosslinking could stabilize the temporary PACG network, showing tunable biodegradability by adjusting ACG/GelMA ratios. Further, a biohybrid gradient scaffold consisting of top layer of PACG‐GelMA hydrogel‐Mn 2+ and bottom layer of PACG‐GelMA hydrogel‐bioactive glass is fabricated for repair of osteochondral defects by a 3D printing technique. In vitro biological experiments demonstrate that the biohybrid gradient hydrogel scaffold not only supports cell attachment and spreading but also enhances gene expression of chondrogenic‐related and osteogenic‐related differentiation of human bone marrow stem cells. Around 12 weeks after in vivo implantation, the biohybrid gradient hydrogel scaffold significantly facilitates concurrent regeneration of cartilage and subchondral bone in a rat model.

Evaluation of Nisin and LL-37 Antimicrobial Peptides as Tool to Preserve Articular Cartilage Healing in a Septic Environment

“…Biomaterials science recently offered an alternative approach for articular cartilage repair based on the possibility to replace the injured tissue by an artificial scaffold substitute resembling the naïve tissue, thus allowing for temporary replacement and a progressive guided self-repair. Some promising examples include the use of hydrogels (Cochis et al, 2017;Cipriani et al, 2019;Bonifacio et al, 2020;Meng et al, 2020), polymers (Pourbashir et al, 2020;Xuan et al, 2020), and composites (Gao et al, 2019;Sun et al, 2019). However, the scaffold synthesis and surgical procedures aimed at the scaffold implantation open the possibility of bacterial infection.…”

Advancements and Frontiers in the High Performance of Natural Hydrogels for Cartilage Tissue Engineering

“…Furthermore, they fabricated a biocompatible composite scaffold with PACG-GelMA hydrogelbioactive glass and PACG-GelMA hydrogel-Mn 2+ layers for osteochondral repair using 3D printing techniques. In vitro and in vivo biological results demonstrate that these biocompatible hybrid gradient hydrogel scaffolds could facilitate cell adhesion, spreading, osteogenic-oriented differentiation, gene expression, cartilage regeneration, and subchondral bone formation in a rat model (Gao et al, 2019).…”

Black phosphorus-based 2D materials for bone therapy

“…The ideal bone tissue engineering repair scaffold needs to have key features such as biocompatibility, biodegradability, bone conductivity and mechanical properties [ 162 ], among which, bone conductivity and good mechanical support capabilities may be essentially required for the development of bone repair materials [ 163 ]. Traditional hydrogels and other scaffolds tend to have good cell adhesion, proliferation and biodegradation capacity, without the ability of bone conductivity and long-lasting mechanical support [ 164 , 165 ]. With the rapid development of 3D printing technology, this demand has been well met.…”