Self-assembled cell sheets composed of mesenchymal stem cells and gelatin nanofibers for the treatment of full-thickness wounds.

Cell sheet engineering has attracted great attention because thin layers of tissue can be easily transplanted to defect sites. Wound-dressing materials are required to support fast re-epithelization, both with keratinocytes and fibroblasts, to enhance the prognosis and therapeutic outcomes. We prepared self-assembled cell sheets composed of adipocyte-derived stem cells (ADSCs) and surface-engineered nanofibrils (NFs). NFs were surface-engineered with multilayers of gelatin so that the cell sheets could spontaneously assemble within 3 days in cell culture plates. Dorsal wounds transplanted with the cell sheets exhibited higher wound-healing rates when a high concentration of gelatin was immobilized on the surfaces of the NFs. Histochemical staining revealed that those with gelatin-immobilized NFs showed a higher expression of cytokeratin and collagen in the re-epithelized epidermis. Keratinocytic differentiation of the epidermis was molecularly evidenced by the higher expression of keratinocyte-specific genes.