The histological observation of hair (H&E stain, ). (a) 1 week after implantation, there was a mild infiltration with a small number of neutrophils and lymphocytes. The multinucleated giant cells were present around polypropylene and the hair. The epithelial cells were observed around the hair. (b) At 1 month, the neutrophils, lymphocytes, and multinucleated giant cells were reduced, while fibroblasts were increased. More epithelial cells surrounded the hair. (c, d, e) At 3, 8 and 12 months after implantation，no obvious infiltration of inflammatory cells was identified and epithelial cells were still seen. Many fibroblasts and collagen fibers were seen around the hair and polypropylene. Infiltration by lymphocytes and reject reaction were not evident at 12 months.