Bioenergetic-active hydrogel drives extracellular matrix synthesis for cartilage repair

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Bioenergy is crucial for cartilage anabolic processes, including extracellular matrix (ECM) synthesis.
• Developing bioenergetic-active materials is a promising strategy for cartilage repair.
• Current cartilage repair methods often lack sufficient bioenergetic support for chondrocytes.

Purpose of the Study:

• To design and evaluate a biodegradable bioenergetic-active hydrogel (BAH) for cartilage repair.
• To investigate BAH's effect on chondrocyte energy metabolism, oxidative stress, and ECM synthesis.
• To assess BAH's efficacy in a rabbit cartilage defect model.

Main Methods:

• Fabrication of an injectable, photo-crosslinkable BAH.
• Assessment of BAH's impact on chondrocyte mitochondrial membrane potential (ΔΨm) and adenosine triphosphate (ATP) production.
• Evaluation of chondrocyte oxidative stress markers (ROS, ATP levels, mitochondrial morphology).
• Analysis of chondrocyte gene expression (ACAN, Col2α1) and ECM synthesis in 3D microtissues.
• In vivo study in a rabbit cartilage defect model with immunohistochemical analysis of ECM components (ACAN, type II collagen).

Main Results:

• BAH significantly enhanced chondrocyte ATP production and mitochondrial membrane potential.
• BAH mitigated oxidative stress in chondrocytes by restoring ATP levels and reducing ROS.
• BAH upregulated ACAN and Col2α1 gene expression and promoted hyaline-like ECM synthesis in vitro.
• In vivo, BAH significantly increased ECM synthesis, ACAN, and type II collagen production in rabbit cartilage defects.
• BAH promoted a native-like chondrocyte arrangement in the repaired cartilage.

Conclusions:

• The developed BAH effectively modulates chondrocyte energy metabolism and rescues them from oxidative stress.
• BAH promotes significant extracellular matrix synthesis, accelerating cartilage repair.
• This bioenergetic-active hydrogel presents a promising therapeutic strategy for articular cartilage injuries.