Study On Collagen-chitosan Electrostatic Spinning Membrane Composite Alginate Anti-seawater Immersion Dressing

Marine workers are vulnerable to injuries while working and can not be effectively treated in a short time.At the same time,seawater has the characteristics of high salinity and high osmosis,which makes the wounds easily edema and difficult to heal after being immersed in seawater.Therefore,for maritime workers,wound dressing not only has excellent hemostasis and healing promoting function,but also should be able to effectively block the damage of seawater to wound.The existing medical dressing has no anti-immersion function,so it is particularly important to develop a wound dressing that can prevent seawater immersion.The waterproof and moisture permeability of PU membrane can well meet the requirements of anti-seawater immersion dressing.In this experiment,30μm,50μm and 80μm PU membranes glued with 20 g,22 g,24 g of 205 adhesives and 28 g and 30g of 3768 adhesive respectively,thus forming three groups of 15 kinds of PU membranes.The comfort,water contact angle,vapor permeability,holding adhesion and peeling strength were measured.A New Zealand white rabbit immersion model was used to exam the effect of anti-seawater immersion of the PU membranes to screen the anti-seawater immersion PU membrane.The results showed that the water contact angle of 50μm PU membrane glued with 24 g of 205 adhesive was more than 90 degrees,suggesting that its surface was hydrophobic;it had good comfort;the vapor permeability is 907 g/24h·m~2.The holding adhesion is 0 mm.The peeling strength is the largest(10.09 N/25mm);anti-seawater immersion time could reach at least 22 hours;thermal stability was good;comprehensive performance was excellent,and it could well meet the requirements of water and moisture permeability of anti-seawater immersion dressing.Collagen-chitosan electrostatic spinning membrane composite alginate dressing was prepared by mixing collagen type I and chitosan in 20:1(mass ratio)ratio and electrospinning them on alginate substrates at high voltage.The composite alginate dressing can absorb 13 times water of its own mass,with 87%porosity and dense micropore structure has good absorption.The pH value is 6.48,which meets the requirements of wound dressing.The water vapor transmission rate is 0.0149 g/h·cm~2.Compound dressing with PU membrane to make collagen-chitosan electrostatic spinning membrane composite alginate anti-seawater immersion dressing.It can prevent seawater immersion,protect wounds,absorb wound exudates,and promote wound healing.The hemostatic properties of CCEAD were evaluated by Blood Clotting Index(BCI)test,rabbit ear artery trauma hemostasis test and rabbit back trauma hemostasis test.Rat back wound model was used to evaluate the wound healing effects.The wound healing rate was calculated by taking pictures on the 3rd,5th,7th and 12th day after operation.HE staining was used to observe histopathological changes.Immunohistochemical staining was used to observe CD31,FGF-2 and TGF-βexpression.Results The BCI of CCEAD group was 36.91%±6.62%,which was significantly less than gelatin sponge group(69.82%±1.83%)and gauze group(79.93%±6.30%)(P<0.01).In the hemostasis test of rabbit ear artery trauma,the hemostatic time of CCEAD group(107.67 s±17.62 s)was significantly shorter than that of gauze group(163.67 s±15.50 s)(P<0.05).In the hemostasis test of rabbit back trauma,the absorbance value of Hb in CCEAD group(0.120±0.052)was significantly lower than that of gauze group(0.294±0.021)(P<0.01).In the wound healing test,on the 7th day after operation,the healing rate of CCEAD group was 65.70%±4.94%,which was higher than that of chitosan dressing group(48.78%±8.33%)(P<0.05)and significantly higher than gauze group(37.76%±6.35%)(P<0.01).HE staining showed that CCEAD could promote fibroblast growth,angiogenesis and granulation tissue formation in the early stage of wound healing.Immunohistochemical results showed that CCEAD could promote the expression of CD31,FGF-2 and TGF-beta in the early stage of wound healing,which was beneficial to wound healing.The safety of CCEAD was evaluated by cytotoxicity test,skin irritation test and skin sensitization test.The results showed that the cells treated with CCEAD extract grew well and were grade 0 non-toxic.CellTiter-Glo cell viability test kit was used to determine the relative viability of HaCat cells and HUVEC cells.The relative viabilities were more than 80%.The relative viabilities of HaCat cells and HUVEC cells were more than 90%by CCK-8 kit.The results showed that cell viability was not inhibited and CCEAD had no cytotoxicity.No obvious pathological changes were observed in rabbit skin after single and multiple administration of CCEAD,suggesting that CCEAD had no obvious irritation.There was no obvious erythema and edema in the skin of guinea pigs in the low and high dose groups of CCEAD.CCEAD had no obvious sensitization effect.It suggests that it is safe and reliable as wound dressing.The collagen-chitosan electrostatic spinning membrane composite alginate anti-seawater immersion dressing can protect the wound from seawater immersion,has hemostatic and healing effects.It has no cytotoxicity,skin irritation and sensitization,safe and reliable and has important significance for wound healing of maritime workers.