Increasing interest in using keratin-based materials for biomedical application has prompted the development of keratin/PVA nanofibers. To date, several kinds of keratins (including wool, feather, and human hair reductive keratins)/PVA blended nanofibers have been fabricated but limited to the in vitro studies. However, few studies focused on the in vivo biocompatibility test of keratin/PVA nanofibers. Herein, the keratose (oxidative keratin)/PVA nanofiber, a novel type of keratin/PVA nanofiber, was fabricated with an electrospinning technique. The obtained nanofibers possess uniform fibrous structure, suitable hydrophilicity and mechanical properties, which could be affected by the mass ratio of keratose to PVA. Furthermore, the biocompatibility tests of keratose/PVA nanofibers have been performed by subcutaneous implantation into SD rats. H&E staining and Masson's trichrome staining revealed that the implants were highly compatible with body tissue; and no acute toxic effects as well as no tissue damage were observed. The implants were fully degraded within four weeks. Beyond this, the analysis of proinflammatoly cytokines in rat serum indicated that the implants induced normal immune response and had no immunogenicity. These results demonstrate that keratose/PVA nanofibers have the potential for biomedical applications due to the favorable biocompatibility and biodegradability. (C) 2016 Elsevier B.V. All rights reserved.