Many investigations in recent years have applied injectable hydrogels as carriers for biologically active factors and as cell transplant vehicles for bone tissue regeneration.
While the hydrogels can be effective at delivering factors and cells to irregularly shaped defects, they often lack an interconnected microporosity to enable infiltration of cells and vasculature to support tissue formation and viability. A recent article by Cui et al. reports optimization of porous injectable chitosan-based hydrogels reinforced with nanoclay particles for bone tissue engineering. The authors found that incorporation of the nanoclay particles mechanically reinforced the hydrogels and introduced porosity into the constructs. The porous hydrogel composites supported osteogenic differentiation of mesenchymal stem cells in culture and promoted bone tissue formation in a mouse calvarial defect model, even in the absence of exogenous growth factor or cell delivery. Overall, the article demonstrates proof-of-concept of an innovative approach leveraging intercalation chemistry to impart porosity into injectable hydrogels capable of recruiting host cells for craniofacial bone tissue regeneration.
Microporous methacrylated glycol chitosan-montmorillonite nanocomposite hydrogel for bone tissue engineering.
Cui ZK, Kim S, Baljon JJ, Wu BM, Aghaloo T, Lee M. Nat Commun. 2019;10(1):3523.