Study On Fabrication And Performance Of Bio-adhesive Fiber Wound Dressing With Waterproofness And Breathability

Over the years,commercial wound dressings such as hydrocolloids,hydrogels and foams,etc.have developed rapidly;however,these dressings generally have problems such as poor skin adhesion,poor waterproofness or breathability.Therefore,it is imperative to design adhesive wound dressings with waterproof and breathable（W&B）capabilities to not only improve the fit and comfort but also achieve high efficiency during wound care,thus promoting wound healing.Electrospinning is a versatile technology that can prepare fiber materials with excellent characteristics such as small pore size,high porosity,considerable specific surface area and controllable morphology.The porosity of the fiber membrane can be controlled by adjusting the electrospinning process parameters,thus obtaining fiber membranes with great breathable properties.However,existing electrospun wound dressings are difficult to possess both W&B properties.In addition,the fibrous hydrogel combines the performance advantages of both fiber and hydrogel,and the microstructure of fibrous hydrogel is vitally similar to the human extracellular matrix（ECM）,which is conducive to the proliferation and growth of tissue cells.Nevertheless,current electrospun fibrous hydrogels have poor adhesion to tissues.Therefore,it is of great significance to prepare wound dressings that integrate waterproofness,breathability and tissue adhesion via electrospinning technology.Aiming to solve the problem that the poor cooperativity of waterproof and breathable properties of existing dressings,W&B PU/PMHS/ES fiber membrane was prepared via using PU as raw material,polymethylhydrosilane（PMHS）as hydrophobic agent,epoxy siloxane（ES）as crosslinking agent.By adjusting the amount of PU,PMHS,and ES,the morphology of the fiber membrane is controlled to synergize its W&B performance.The obtained PU/PMHS/ES0.50 fiber membrane possessed the relatively comprehensive performance:high hydrostatic pressure（22.37k Pa）,high water vapor transmission rate（WVTR）(8.5 kg m^-2d^-1),excellent tensile strength（10.73MPa）and elongation at break（366%）.The tissue adhesion of commercially available dressings is generally poor,which makes them easy to fall off during long-term use.To solve the above problems,a sort of self-adhesive GT/EDC-NHS-DA fibrous hydrogels were prepared via using GT as raw material,dopamine（DA）as adhesive agent,1-（3-dimethylaminopropyl）-3-ethylcarbodiimide（EDC）and N-hydroxysuccinimide（NHS）as coupling agents.Inspired by marine mussel protein secretion-curing mechanisms,the in-situ sequential crosslinking method allows the non-oxidized form of DA to be retained under acidic spinning conditions and imparts unique adhesiveness to the fiber hydrogel during the subsequent cross-linking process.The introduction of DA via the in-situ sequential crosslinking approach imparted the resultant GT/EDC-NHS-DA1 fibrous hydrogel with extraordinary bio-adhesion and mechanical performance,which were 1.5 times and 3.1 times higher than that of commercial Mepiform^?dressing,respectively.Full-thickness skin experiments confirmed that the wounds of Balb/c mice could basically heal under the treatment of GT/EDC/NHS/DA1 fiber hydrogel as a wound dressing.In order to obtain the W&B wound dressing with bio-adhesiveness,we finally used the previously prepared PU/PMHS/ES W&B fiber membrane as the outer layer and GT/EDC-NHS-DA bio-adhesive repairable fibrous hydrogel as the inner layer to prepare the PU/GT double-layer fiber membrane,then its morphology and performance were characterized.The consequent PU/GT double-layer fibrous hydrogel possessed excellent water resistance,moisture permeability,tissue adhesion,mechanical properties and biocompatibility as expected,suggesting its promising future as a versatile functional joint wound dressing.