Acceleration of wound healing by a porous collagen/silk fibroin scaffold carrying zinc oxide nanoparticles / 中国组织工程研究

ABSTRACT

BACKGROUND:Anti-infective ability determine the success or failure of skin grafting. It is one of the commonly used methods to enhance the anti-infective ability of implants by compounding antibacterial materials with scaffolds. OBJECTIVE:To investigate the effect of porous collagen/silk fibroin scaffolds carrying zinc oxide nanoparticles against infection and inflammation, and to evaluate its effect on wound healing. METHODS:Thirty-two Sprague-Dawley rats with a full-thickness wound on the back skin were randomly divided into two groups. In experimental groiup, porous collagen/silk fibroin scaffolds containing zinc oxide nanoparticles were implanted, while only collagen/silk fibroin scaffolds were implanted in control group. Wound healing was compared between the two groups by measuring residual wound area at 1, 2, 4, 8 weeks post implantation. Hematoxylin-eosin and interleukin 6 immumohistochemical staining were performed at 1, 2, 4 weeks post implantation to observe wound morphology and inflammatory reactions. Meanwhile, expression of interleukin 6 and interleukin 1β was detected by real-time PCR. RESULTS AND CONCLUSION:(1) At 2, 4, 8 weeks post implantation, significantly increased healing rate was observed in the experiment group compared with the control group (P<0.05). (2) Findings from the hematoxylin-eosin staining showed that obvious inflammatory cell infiltration was observed in the control group, but less inflammation with vigorous growth of granulation tissues on the wound surface occurred in the experimental group at 1 week after implantation. Then, the wound repair was basically completed in the experimental group presenting with complete and compact epidermal tissue structure, while scar formation with no skin cover was found in the control group at 4 weeks after implantation. (3) Findings from the interleukin 6 immumohistochemical staining showed that there was interleukin 6 positive expression in both two groups to different extents; at 4 weeks after implantation, the expression of interleukin 6 was remarkably reduced in the control group, but it was still a strong positive expression, while week positive expression of interleukin 6 was observed in the experimental group. (4) Compared with the control group, the mRNA expression of interleukin 6 and interleukin 1β was both lower in the experimental group at 1, 2, 4 weeks after implantation, but there was a significant difference between the two groups at 1 and 2 weeks after implantation (P<0.05). Overall, the porous collagen/silk fibroin scaffold carrying zinc oxide nanoparticles can effectively reduce inflammations following skin injury, and accelerate skin wound healing.