Fig. 5

Representative studies for diabetic-skin models. a Schematic showing that even a small wound can become an ulcer owing to the poor wound-healing ability in patients with diabetes [47]. b Biofabrication process for the diabetic-skin model [48]. First, diabetic foot-ulcer fibroblasts contained in type I collagen were seeded onto the hanging cell-culture insert, which was followed by maturation for the dermal equivalent for three weeks of culture. Keratinocytes were then seeded on the dermal equivalent and allowed to proliferate for 5 d. Finally, an air–liquid interface culture was used to differentiate the keratinocytes, followed by the formation of stratified epidermal layers. c Comparison of skin models comprising human-foreskin, nondiabetic adult-foot, and diabetic foot-ulcer fibroblasts [48]. d Biofabrication strategy to create the diabetic-skin model via dermal–epidermal crosstalk [47]. e Wound fabrication using a 3D bioprinting device and wound-healing analysis via hematoxylin and eosin staining [47]. f Perfusion of metformin via a bioprinted vascular channel in the diabetic-skin model [47]. g Application of the diabetic-skin model as a drug-testing platform [47]. Reprinted with permission from Ref. [47, 48]