Nanofiber Composite Microchannel-Containing Injectable Hydrogels for Cartilage Tissue Regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Articular cartilage lacks self-repair capabilities, necessitating advanced therapies for defects.
• Injectable hydrogels are promising for cartilage regeneration due to their minimally invasive application.

Purpose of the Study:

• To develop novel nanofiber composite microchannel-containing injectable hydrogels for articular cartilage regeneration.
• To investigate the properties and efficacy of these hydrogels in promoting chondrogenesis and neocartilage formation.

Main Methods:

• Constructed injectable hydrogels (APA/CMCS/KGN@PGF/GM) using aldehydized polyethylene glycol/carboxymethyl chitosan, gelatin microrods, and kartogenin-loaded polylactic acid/gelatin fibers.
• Evaluated in situ formation, micromorphology, porosity, swelling, degradation, mechanical properties, self-healing, and drug release.
• Assessed hydrogel effects on bone marrow mesenchymal stem cell (BMSC) proliferation, ingrowth, chondrogenesis, and neocartilage formation in a rabbit model.

Main Results:

• The hydrogel demonstrated good self-healing ability and improved mechanical properties with nanofiber incorporation.
• Sustained release of kartogenin was achieved, aligning with cartilage repair timelines.
• The microchannel structure significantly enhanced BMSC proliferation and ingrowth.
• In vitro and in vivo studies confirmed enhanced chondrogenesis and neocartilage formation.

Conclusions:

• The developed nanofiber composite microchannel-containing hydrogels show significant potential for cartilage regeneration.
• The combination of microchannels, nanofibers, and sustained drug delivery offers a promising therapeutic strategy for cartilage defects.