Hydrogels for Osteochondral Interface Regeneration: Biomaterial Types, Processes, and Animal Models

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• The osteochondral interface (OCI) is critical for joint function but has poor healing capacity due to its avascular and hypocellular nature.
• Current surgical treatments for OCI injuries are suboptimal, driving interest in regenerative strategies.
• Hydrogel-based biomaterials offer potential for OCI regeneration by mimicking the extracellular matrix.

Purpose of the Study:

• To review current hydrogel types, scaffold processing techniques, and animal models used for osteochondral interface regeneration.
• To identify key challenges and future directions for translating hydrogel-based OCI regeneration strategies to clinical practice.

Main Methods:

• Systematic literature review of hydrogels, scaffold fabrication, and animal models for OCI regeneration.
• Analysis of common hydrogel materials (gelatin, alginate, chitosan, hyaluronic acid) and scaffold designs (layered constructs).
• Evaluation of advanced processing techniques (3D printing, extrusion) and common animal models (rabbits).

Main Results:

• Gelatin, alginate, chitosan, and hyaluronic acid are frequently studied hydrogels for OCI regeneration.
• Layered scaffolds are common, but 3D printing and extrusion offer potential for graded architectures mimicking native OCI.
• Rabbit models are prevalent, but larger animal studies are needed for clinical relevance.

Conclusions:

• Hydrogels show significant potential for osteochondral regeneration, with specific materials and fabrication methods demonstrating promise.
• Advanced techniques like 3D printing can create biomimetic graded architectures.
• Future research must prioritize mechanically robust, biologically active, graded hydrogels and validation in large-animal models for clinical translation.