Natural Tissue-Imprinted Biointerface for the Topographical Education of a Biomimetic Cell Sheet.

Cell sheet engineering as a cell-based scaffold-free therapy is promising in tissue engineering, allowing precise transforming treatments for various tissue damage. However, the current cutting-edge techniques are still hampered by the difficulty in mimicking the natural tissue organizations and the corresponding physiological functions. In this work, cell-imprinting technology using the natural tissue as a template was proposed to rationally educate the cellular alignment in the cell sheet. Through this technique, we obtained temporary templates with morphological structure complementary to native tissues and then directly transferred the structure on the template to the collagen layer on a photothermally convertible substrate by secondary imprinting replication. The resultant biomimetic interface was used for cell culture and release to obtain a cell sheet with a texture similar to the natural tissue morphology. Different from conventional photolithography, the natural tissue-imprinted biointerface guides the geometry of cell sheets in the way of natural principles instead of stereotyped or overuniform cell organization. Simultaneously, a near-infrared laser (NIR) was used to irradiate the photothermally responsive substrate to obtain complete cell sheets efficiently and nondestructively. The natural tissue-educated myocardium cell sheets exhibited good physiological activity and biomimetic biofunctions, such as mechanical properties and physiological performances. This approach might open an inspiring prospect in regenerative medicine and offer a new approach to realizing the biomimetic tissue construction.