A comprehensive review on using injectable chitosan microgels for osteochondral tissue repair

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Cartilage restoration is hindered by low cell density and limited regenerative capacity.
• Existing cartilage repair platforms lack clinical translatability and require specialized handling.
• Higher concentrations of engineered cell microaggregates can promote cartilage formation without exogenous growth factors.

Purpose of the Study:

• To review the application of chitosan as an injectable hydrogel for osteochondral defects.
• To highlight chitosan's potential for creating cell-laden microgels for in vivo microaggregate formation.
• To explore chitosan's suitability for minimally invasive, one-step surgical treatments.

Main Methods:

• Review of studies focusing on encapsulating mesenchymal stem cells within chitosan hydrogels.
• Identification of microfluidic devices as a key technology for forming chitosan microgels.
• Assessment of chitosan's printability for 3D printing in cartilage tissue engineering.

Main Results:

• Chitosan hydrogels demonstrate potential as injectable bioinks for tissue regeneration.
• Microfluidic techniques are effective for generating cell-laden chitosan microgels.
• Chitosan's properties are suitable for both injectability and 3D printing applications in cartilage repair.

Conclusions:

• Chitosan-based injectable hydrogels are a promising strategy for treating osteochondral defects.
• The development of cell-laden microgels using chitosan facilitates in situ cartilage formation.
• Chitosan offers a versatile material for minimally invasive and potentially one-step cartilage regeneration therapies.