Establishment of an animal model for human keloid scars using tissue engineering method.

The aim of this study is to establish an animal model for human keloid scarring using tissue engineering method and to improve the research for keloid scarring in clinical and laboratory settings. After primary and passage culture, human keloid fibroblasts (KFBs) were transferred to poly(lactic-co-glycolic acid) (PLGA) copolymer and cultured in a rotatory cell culture system for 1 week. The complex of KFBs and PLGA (experimental group), and PLGA only (control group) were then transplanted to subcutaneous pouches in athymic mice. The implants were collected on days 30, 60, 120, and 180 for histological observation. All mice survived after surgery. The size of implants in the experimental group kept increasing from days 30 to 180, whereas the implants in control group became smaller. Using different histological stainings, KFB and collagen were observed at all time points in the implants under light microscopy. Large amounts of KFBs and collagen were found in the implants of day 180, which exhibited similar histological features to human keloid. Also, the fibroblasts in the implants had abundant rough endoplasmic reticulum in the cytoplasm under transmission electron microscopy. These findings indicate that the fibroblasts retain cellular characteristics in the implant. The combination of KFBs and PLGA can form keloid-like tissue in athymic mice. Establishment of this promising animal model for keloid is worthwhile, and this model might help our understanding of the pathological process and our ability to evaluate drug efficacy to human keloid scars in clinical trials.