| Objective: To investigate the mechanism of silk fibroin in repairing the dermal defects in rats, the expression levels of CD90, TGF-β,α-SMA, Collagen I and III in fibroblasts during the repairing of dermal defects with Antheraea Yamamai silk,Bombyx mori silk or sponge stent, were detected by immunohistochemistry. Furthermore, we tried to probe the effects of silk fibroin on main repairing cells and to estimate the correlation of the CD90 expression in fibroblasts and their functions of proliferation,synthesis and constringency.Methods: 1. 144 male SD rats were randomly divided into 3 groups: Group A with Antheraea Yamamai silk (n=48), Group B with Bombyx mori silk (n=48), and Group C with sponge stent as control (n=48). The thin split-thickness skin grafts were covered with three types of materials to repair the back wounds on rats (2cm*2cm). After 5d, 10d, 15d and 25d, the specimens were taken and fixed in 10% formalin, made-up the paraffin sections, finally stained with HE. 2. According to the result of HE staining, the sampling point was located. One sampling point for each tissue section of four different time points was selected to construct a 6*6 tissue clip. Each clip included 36 tissue sections and totally 144 sections. 3. Four tissue chips were stained with immunohistochemistry to detect the expression of CD90, TGF-β,α-SMA, Collagen I and III in different time points and statistical analysis was performed for the observed results. 4. The correlation between the expression of CD90 and that of the other four kinds of proteins was also analyzed.Results: 1. The composite skin grafts grew and survived well in both Group A and Group B, while most of the transplants in Group C were necrotic and scabbed, even dropped. 2. The tissue chips were successfully constructed for the immunohistochemical detection and the multiple factors'analysis. 3. The results of immunohistochemical staining demonstrated a higher expression in CD90 in Group A and Group B in the stage of 10d,15d, and with a decrease in 25d. There was no significant statistical difference between the two groups (P>0.05). However, a significant difference was found between group C and group A/B (P<0.05). 4. TGF-βl andα-SMA expressed weakly in 5d, while that a higher expression was observed in 10d,15d and declined in 25d. And there was no significant statistical difference (P>0.05). Nevertheless, a significant difference (P<0.05) was found between group C and group A/B. 5. Collagen I and III were highly expressed in group A/B in 15d,25d, but showed no significant difference (P>0.05). Meanwhile, a significant statistical difference (P<0.05) was observed in comparison with sponge stent group. 6. Statistical analysis verified a significant correlation of CD90 expression in fibroblasts with that of TGF-βl andα-SMA.Conclusion: 1. It was demonstrated that the local inflammatory reactions of the two kinds of silk fibroin were milder, which had no significant statistical difference. Therefore, the silk fibroin was a good material with nice tissue compatibility, which satisfied the requirement of substituting dermis. 2. With a high efficiency and well quality control, the tissue chips were suitable for multiple factors'investigation and could be further applied in the study of dermal defects repairing in rats. 3. As the transplant of dermis, silk fibroin attracted the fibroblasts which lied in the basal of the wound. Finally, the CD90 expression of silk fibroin was decreased, that repressed the fibroblasts proliferating to myofibroblasts and reduced the scar atrophied. 4. The expression of CD90 had significant correlation with that of TGF-βl andα-SMA, which might have some synergistic relationships during the repair proceeding of dermal defects with porous silk fibroin in rats. |
PDF Full Text Request