۳D Skin Printing: In-Situ Formation of Planar Tissues

Background: Wound healing and coverage are the crucial determinantsof burn patient survival. However, these are limitedby factors such as limited skin availability, size, and cell availability.Conventional wound dressings merely protect from infectionand absorb exudate fluid as passive layers. Of the currenttreatments for skin, autografts are limited in the extent ofavailable tissue, cell cultured epithelial autografts (CEA) graftshave a limited thickness and mechanical stability, and syntheticskin grafts (such as collagen/silicone bilayers) have slow cellinfiltration. There is a significant potential for wound dressingsas active devices to dynamically participate in the wound repairprocess through cell and scaffold delivery to the wound.Materials and Methods: A skin printer that enables the in-situformation of biomaterial and skin tissue sheets of different homogeneousand architected compositions will be introduced.Results: Consistent sheet formation is achieved by coordinatingthe flow rates at which bioink and cross-linker solution aredelivered, with the speed at which a pair of rollers activelytranslate the cartridge along the surface. Upon rapid crosslinking,biomaterial and skin cell-laden sheets of consistent thickness,width and composition were obtained. Proof-of-principledemonstrations for the in-situ formation of biomaterial sheetsin murine and porcine excisional wound models illustrate thecapacity of depositing onto inclined and compliant wound surfacesthat are subject to respiratory motion.Conclusions: The presented work will enable the in-situ deliveryof a wide range of different cells, biomaterials, and tissueadhesives, as well as the in-situ fabrication of spatially organizedbiomaterials, tissues, and biohybrid structures.