Preparation and characterization of human scar acellular dermal matrix

Acellular dermal matrix (ADM) is commonly used to treat burn injuries and wounds. In this study, we aimed to analyze the structural and biomechanical characteristics of an ADM from human scars.We randomly selected human mature scars, human proliferative scars, and human normal skin as experimental specimens. Split-thickness dermal grafts were obtained using a free-hand graft knife. Samples were subjected to cell lysis to obtain ADMs. Structural analysis was performed via light microscopy, fluorescence microplate reader and scanning electron microscopy. Thereafter, human epithelial stem cells were incubated on these ADMs. Finally, the biomechanical characteristics of the ADMs were analyzed using a tensile machine.Normal skin ADM fibers were arranged in order, whereas proliferative scar ADM fibers were dense and disordered, and mature scar ADM fibers were porous and slightly disordered. The residual DNA of three ADM meet the residual DNA standard of biological material. After incubating human epithelial stem cells on ADMs, cells grew in an aggregated state in both normal skin ADMs and mature scar ADMs; however, cells adhered only on the surface of proliferative scar ADMs. No significant differences were observed in the Young's modulus, relaxation slope, creep slope, creep, or maximum tensile stress among the three ADMs, although significant differences in stress-strain elongation and relaxation were noted.Our findings showed that mature scar ADMs were similar to proliferative scar ADMs, showing a slight lag compared with normal skin ADMs, providing insights into the biomechanical features of these scar tissues. Abbreviations ADM Acellular dermal matrix H&E Hematoxylin and eosin PBS Phosphate-buffered saline SEM Scanning electron microscopy.