Preparation And Properties Of Silk Fibroin-based Electrospun Multi-stage Composite Fiber Dressings

Wound dressings can provide a suitable environment for wound healing during wound treatment,and at the same time play a protective role in barriers.In order to speed up wound healing,wound dressings need to have good antibacterial properties,air permeability and have the function of removing excess wound exudate.The development of functional new dressings is an effective way to improve the efficiency of wound healing.This article mainly uses electrostatic spinning and electrostatic spraying technology to prepare a multi-level composite nanofiber membrane with functions of draining excess exudate from the wound surface and antibacterial.The specific process is as follows:First,in order to improve the biocompatibility of the dressing,electrospinning technology is used to prepare silk fibroin/polycaprolactone(SF/PCL)nanofiber membranes.The biocompatibility was explored,and the experimental results showed that the cell activity on the nanofiber membrane was significantly improved after adding SF.In addition,when the feed rate ratio of SF and PCL is 1:3,the water contact angle of the SF/PCL nanofiber membrane reaches 112°,which has good hydrophobicity and can provide a hydrophobic layer material for the construction of heterogeneous composite nanofiber membranes.Next,in order to construct composite nanofiber membranes with different wetting gradients and achieve the effect of unidirectional water conduction,this study used electrospinning technology to prepare polyvinyl alcohol(PVA)nanofiber membranes for cross-linking and hydrophilic treatment,and then with Hydrophobic SF/PCL nanofiber composite.The research results show that as the immersion time of the PVA nanofiber membrane in the dopamine solution increases,its hydrophilicity is significantly improved.The results of the moisture management test(MMT)show that when the electrospinning time of the hydrophobic SF/PCL fiber layer is 5 minutes,the composite nanofiber membrane has the function of unidirectional water conduction,and the cumulative unidirectional transmission capacity(AOTC)of the composite membrane reaches 726.56%.Finally,in order to prepare functional medical dressings,electrostatic spraying technology is used to composite micron-sized mesoporous nano-silica(MSN)-SF/CS antibacterial drug-loaded microspheres and PVS-SF/PCL nanofiber membrane to prepare drug-loaded antibacterial The multi-stage composite unidirectional waterconducting membrane.The prepared MSN was successfully coated in SF/CS microspheres.The drug-loading performance and drug release of the microspheres were tested,and the cumulative release curve in vitro showed a trend of steep first and then slow,and the final release amount reached 54.46%.And the sample has good antibacterial and biocompatibility.In addition,when the electrostatic spraying time is10 minutes,the AOTC of the composite film reaches 651.75%.In summary,the unidirectional water-conducting composite membrane loaded with MSN-SF/CS antibacterial drug-loaded microspheres can drain excess exudate from the wound surface and maintain a certain degree of wettability,which is conducive to wound healing.Therefore,the composite nanofiber membrane It can be used for further research on wound dressings.