Preparation And Application Study On Natural Bioactive Substances Loaded Electrospun Nanofibrous Wound Dressing

The use of wound dressings with antibacterial and antioxidant activity to wrap wounds is of great significance for promoting wound healing.Traditional wound dressings are loaded with antibiotics or silver nanoparticles to prevent bacterial infections.However,these antibacterial agents have the problems of bacterial resistance or biological toxicity,which prompted researchers to explore new bioactive wound dressings.Recently,natural active substances have received more and more attention in the field of wound treatment due to their biocompatibility,antibacterial,antioxidant and other biological activities.In addition,the nanofibrous membrane prepared by electrospinning can mimic extracellular matrix in structure,which is conducive to cell adhesion,migration and proliferation,and functionally can release various drugs,thereby promoting wound healing.Thus,in this study,natural active substances were loaded in electrospun nanofibrous membranes,and then the performances of nanofibrous membranes as wound dressings were explored.The main research contents and conclusions are as follows:Firstly,honey loaded alginate/polyvinyl alcohol nanofibrous wound dressing was prepared by blending electrospinning.Before electrospinning,the influence of honey content on the properties of the electrospinning solution was explored.With the increment of honey content,the viscosity and conductivity of the electrospinning solution decreased.The morphology of the nanofibrous membrane was observed by scanning electron microscopy.It was found that the average diameter of the nanofibers increased with the increment of honey.In the Fourier transform infrared spectroscopy spectra,the characteristic peaks of honey appeared in the nanofibrous membrane,indicating that the honey was successfully loaded in the nanofibrous membrane.The absorptive capacity of the nanofibrous membrane to wound exudate was simulated by measuring the swelling rate,and it was found that as the honey content increased,the water absorption performance of the nanofibrous membrane decreased,while the weight loss of the nanofibrous membrane increased instead.With the increase of honey content and reaction time,the antioxidant activity of nanofibrous membrane increased.The honey loaded nanofibrous membrane showed antibacterial activity against both Grampositive bacteria and Gram-negative bacteria,and had stronger antibacterial activity against Gram-positive bacteria.The biocompatibility assay indicated that the prepared nanofibrous membrane had no obvious cytotoxicity.Secondly,a series of coaxial nanofibers incorporated with tea polyphenols in the core layer and ?-poly(L-lysine)in the shell layer were prepared by coaxial electrospinning.The physicochemical characterizations by transmission electron microscopy,inverted fluorescence microscopy and Fourier transform infrared spectroscopy demonstrated the formation of coreshell structure.The water vapor transmission experiment showed that all of the prepared nanofibrous membranes possessed good water vapor transmission performance.The addition of tea polyphenols resulted in a decrease in the tensile strength of the nanofibrous membrane,while the addition of ?-poly(L-lysine)did not have a significant effect on the mechanical properties of the nanofibrous membrane.According to the results of in vitro drug release,?-poly(L-lysine)showed a fast release profile while tea polyphenols exhibited a sustained release profile,which could inhibit the growth of bacteria in the initial phase and could achieve long-term antioxidant activity.With the increase of tea polyphenols content and reaction time,the antioxidant activity of coaxial nanofibers increased.The antibacterial test showed that the prepared coaxial nanofibers loaded with ?-poly(L-lysine)had strong antibacterial activity against Escherichia coli and Staphylococcus aureus.Finally,the biocompatibility of nanofibrous membrane was explored,and it was found that all of the prepared coaxial nanofibers displayed low cytotoxicity.In summary,the prepared two kinds of nanofibrous membranes loaded with natural active substances had antibacterial and antioxidant activities,and were biocompatible,which are promising as potential wound dressing materials.