In situ miRNA delivery from a hydrogel promotes osteogenesis of encapsulated mesenchymal stromal cells.

Hydrogels are attractive candidates for use in tissue-engineering and the encapsulation and subsequent differentiation of mesenchymal stem/stromal cells (MSCs) is a strategy that holds great promise for the repair and regeneration of bone and cartilage. However, MSCs are well-known for their sensitivity to mechanical cues, particularly substrate stiffness, and so the inherent softness of hydrogels is poorly matched to the mechanical cues that drive efficient osteogenesis. One approach to overcome this limitation is to harness mechanotransductive signalling pathways and override the signals cells receive from their environment. Previous reports demonstrate that mechanosensitive miRNAs, miR-100–5p and miR-143–3p can enhance MSC osteogenesis, using a complex multi-step procedure to transfect, encapsulate and differentiate the cells.