2D and 3D co-spatial compartmentalized patch to enhance the therapeutic efficacy of keratinocytes for wound closure

Keratinocytes are frequently used for the biological and biomedical remodeling of damaged skin tissues. However, low cell viability, poor cell maintenance, and lack of paracrine factors hamper the therapeutic efficacy of keratinocytes for skin wound healing. Here, we report the fabrication of a 2D and 3D co-spatial compartmentalized patch (CSCP) for a microscale keratinocyte-engineering platform and a novel method for delivering keratinocytes to enhance wound closure compared to that achieved by the conventional keratinocyte delivery method. Micro-sized cylinders engraved within a polydimethylsiloxane (PDMS) substrate were fabricated to induce and trap 3D keratinocyte clusters. Simultaneously, the outer surface of the PDMS substrate was used as an area for 2D keratinocyte culture. As a result, the CSCPs could be simultaneously applied for both 2D and 3D in vitro keratinocyte culture and in vivo cell delivery. The 3D keratinocytes increased the cell density for delivery and angiogenic factor expression but decreased the cell proliferation, which was complemented by the high proliferation of 2D keratinocytes. Our in vivo results confirmed that the therapeutic efficacy of keratinocytes for wound closure was significantly enhanced when the cells were delivered in a 2D and 3D co-spatial manner. We used the CSCPs to improve the wound closing efficacy of keratinocytes by simple dual spatial control, which was supported by the simultaneous upregulation of molecular mechanisms, and provided new insights for the development of a large-scale keratinocyte delivery system for skin wound healing.