Preparation And Evaluation Of Silk Fibroin-based Gel Coat Dressings

As a covering at the wound,the medical dressings play a temporary role in replacing the damaged skin and play an important role in the healing of the wound.At present,there are many kinds of medical dressings,and the hydrogel dressing as a new medicine dressing has become the focus of research.As a natural high molecular protein,silk fibroin has excellent biocompatibility,mechanical properties and diverse plasticity,and can form silk fibroin hydrogel under various induction conditions.Therefore,this paper used cotton fabric as a base,and used different forms of silk fibroin hydrogels as carriers to prepare antibacterial and anti-inflammatory functional dressings,and a systematic basic research was carried out.Firstly,three typical silk fibroin gels of silk fibroin/PEG400 gel,silk fibroin/methanol gel and silk fibroin/HRP gel were prepared and used as functional layer materials to coat fsbroins,and conducted a series of tests related to dressing properties.It was found that the permeability and flexibility of silk fibroin/PEG400 gel,and silk fibroin/methanol gel met the requirements of dressings.The silk fabric/HRP gel coated fabric has poor flexibility and permeability,which seriously affects the performance of the dressing.Therefore,HRP gel was excluded from the study.Secondly,silk fibroin/PEG400 gel and silk fibroin/methanol gel were loaded with antibacterial factor(nano silver)and anti-inflammatory factor(curcumin)respectively to prepare gel-coated fabric with antibacterial and anti-inflammatory functions.The in vitro release of curcumin from curcumin loaded gel dressing showed that curcumin could be released quickly within 12 hours,and the cumulative release rate of curcumin in silk fibroin/PEG400 gel functional layer material was greater than that of silk fibroin/methanol gel.The antibacterial experiments on nano-silver dressings showed that the antibacterial activity was the best when the concentration of nano-silver was 80 ug/mL.The inhibition zone width of the dressing was 1.45±0.14 mm for E.coli and 2.10±0.21 mm for S.aureus.After the gel was placed for 60 days,the inhibition zone width for E.coli was 1.29±0.09 mm,and 2.47±0.17 mm for S.aureus.,The gel material showed good bacteriostatic stability.When the antibacterial gel was applied to the fabric,the inhibition rate against S.aureus reached 100%,and the inhibition rate against E.coli was 95%.The results shown that the prepared gel-coated fabric has great potential as a dressing.Finally,biological evaluation(in vitro degradation and cell compatibility experiments)of gel material was conducted.The in vitro degradation experiments showed that the silk fibroin/PEG400 gel had good degradability,and the weight of the gel remained 37.5%within six days,which was better than the remaining 68.3%of the weight of the ultrasonic gel material that as a control.The results of mouse fibroblast compatibility experiments show that the silk fibroin/PEG400 gel material had good biocompatibility,and after 7 days of culture,the morphology of the mouse fibroblasts was good and the number of mouse fibroblasts was increased.In summary,a coated fabric with asilk fibroin gel material as a coating was prepared,The gel coated fabric was used as a potential dressing and related properties have been studied.It is concluded that silk fibroin gel coated fabric has great potential as dressing,and provided a new method for the development of dressing.