Fabrication And Properties Of Fibrous Membrane/Sponge Composite Wound Dressings

Skin wound repair has always been a common and considerable problem due to infection,and electrolyte balance disorders.Wound dressing,which is an effective approach to promote wound healing,has developed rapidly in recent years.In particular,sponge dressings have drawn widespread attention owing to their high porosity and excellent liquid absorption capacity.However,its hemostatic performance still required to be improved,and promoting wound healing still face a lot of challenges.Therefore,there is an urgent need to develop composite dressings with effective hemostasis and wound repair performance.Electro-spun nanofibers have broad prospects in the field of tissue repair since they can simulate the natural extracellular matrix,and effectively promote cell adhesion,migration,and proliferation.In our previous study,we have developed a radially aligned nanofibrous membrane loaded with stromal-cell-derived factor 1α(SDF-1α).It was found that the scaffolds could effectively promoted wound healing,but it lacked hemostatic properties.Therefore,in order to prepare a medical dressing with good hemostasis and wound repair functions,we designed a multi-functional wound dressing by combining nanofibrous membranes and sponge together.We firstly prepared radially aligned nanofibrous membrane comprising of polycaprolactone(PCL)and gelatin(GT),with the collector composed of needle electrode array and a ring electrode.Further,the membrane was covered on the chitosan and dopamine(DA)solution,and the fibrous membrane/chitosan sponge composite scaffold was prepared by a freeze-drying method.By adjusting the concentration of coupling agent DA and the crosslinking time,the adhesion force between two layers of fiber/sponge composite(FSC)was improved.In addition,a cyclic compression test was performed,and the results showed that FSC has excellent shape recovery property in water.Finally,the biological performance of the FSC scaffold was studied,including in vitro coagulation performance,platelet adhesion performance,in vivo hemostasis property and wound healing capability.The results showed that the addition of DA could effectively enhance the adhesion performance between the PCL/GT nanofibrous membrane and chitosan sponge with a peeling strength of 4.09 k Pa,leading to improved stability of FSC scaffold interlayer structure.Meanwhile,the shape recovery of FSC-DA scaffolds was about 73.5% after 100 cycles in water,indicating good compression resilience performance under wet conditions.In terms of hemostatic performance,the FSC scaffolds significantly improved hemostasis and coagulation performance than single-layer PCL/GT nanofibrous membrane and commercial gelatin sponge.The FSC scaffolds showed a coagulation index BCI value of only 20.5%,which is a third of the commercial gelatin sponge.Furthermore,for in vivo hemostasis experiment,the blood loss of commercial gelatin dressing reached 95.4 mg,while the blood loss of FSC scaffold was only58.5 mg.In wound repair experiment in rats,FSC scaffold showed excellent wound healing capacity compared to traditional gauze and commercial gelatin dressings.On the 12 th day,the wound contractions of gauze group and commercial gelatin dressing group were about 79.62%and 83.24%,respectively.Whereas,SDF-1α/FSC scaffold group was almost healed,with a wound contraction of 98.69%.Additionally,compared with the pristine FSC scaffold group,the wound contraction of SDF-1α/FSC scaffold group increased 9.6% owing to the addition of SDF-1α.In summary,the prepared nanofibrous membranes/chitosan sponge composite scaffolds showed multiple functions,including good cyclic compression capability,shape recovery property,hemostasis and coagulation performance,and wound healing property,which shows a great potential in the field of wound dressings.