Study Of A Anti-adhesion Hydrogel Medical Dressing For Diabetic Epidermal Trauma

Currently,poor wound healing caused by chronic diseases has affected millions of people around the world.Diabetic wounds are the most common in the classification of chronic wounds,and have been widely concerned because of the large number of patients with diabetes and the high growth rate.At present,hyperbaric oxygen therapy and local oxygen therapy are used to treat diabetic wounds,but the treatment equipment is too large to realize portable and continuous treatment.Due to its adjustable mechanical properties,good biocompatibility,high porosity,swelling and drug loading properties,hydrogel has widely used in wound dressings to achieve the effect of promoting wound healing.Because diabetic wounds have been in a high glucose and hypoxia environment for a long time,continuous oxygen supply to the wound is a necessary condition for wound healing.However,ordinary hydrogel dressings cannot provide continuous oxygen supply,so it is a challenge to realize diabetic wound healing through continuous oxygen supply with hydrogel dressings.In this paper,polyvinyl alcohol-sodium alginate double network hydrogel was used to fix and disperse oxygen releasing microspheres,and dissolved oxygen was generated and released by oxygen releasing microspheres.Double-network hydrogels have higher drug delivery efficiency compared with single-network hydrogels because of the dense cross-linking network and stronger capillary effect between networks.The overall preparation of the dressing can be made using 3D printing technology.Due to the anti-adhesion properties of hydrogel,Gel MA hydrogel with adhesive properties can be 3D printed to fix the dressing on the wound.Meanwhile,a layer of PDMS can be printed on the surface of the dressing to prevent moisture evaporation when the dressing is exposed to the air,which has anti-water loss properties.The hydrogel dressing encapsulated by 3D printing can achieve adhesion function,and will not cause adhesion to the wound.In this work,PVA,PVA/Alg,PVA-Alg(1%wt Ca2+)and PVA-Alg(2%wt Ca2+)four hydrogel materials were tested the changes of surface morphology.It was found that the addition of sodium alginate would make the original fibrous surface of PVA more smooth,and the fibrous surface structure would gradually become prominent with the increase of the number of freezing cycles.At the same time,the changes of Raman peaks of four hydrogels were observed by Raman microscope.The mechanical properties of the four hydrogels were characterized.Finally,the young’s modulus of the hydrogels selected for animal experiment was about 30 k Pa,which was suitable for human skin modulus and could better fit the wound surface.The double network structure of hydrogel can improve the swelling,and the swelling rate in this study can reach 600%.In this paper,anti-adhesion properties,antibacterial properties and biocompatibility were further tested,and the hydrogel was found to have low adhesion,with adhesion energy of 5 J/m2.The double-network hydrogel studied in this paper can prevent the hydrogen peroxide produced by calcium peroxide from oxidizing the wound by adding catalase,which is not conducive to wound healing.The test results of oxygen production characteristics showed that the peak oxygen production was independent of the amount of calcium peroxide,and the oxygen production of the double network hydrogel was relatively stable in the 8-day cycle test,and the dissolved oxygen maintained at about 350 μM.The results of antibacterial and biocompatibility test showed that the dressing had good antibacterial and biocompatibility.Through animal experiments,the wound healing status of diabetic rats 14 days after operation was compared,and the healing status and pus status of oxygen-producing dressing were better than those of other experimental groups.To sum up,this paper utilizes the advantages of swelling,mechanical properties and drug delivery performance of double-network hydrogels to study the sustainable oxygen-releasing anti-adhesion hydrogel dressing that can promote the healing of diabetic wounds through the continuous release of oxygen to the diabetic wound by oxygen-releasing microspheres.On the basis of prolonging the service time of the dressing,the stripping damage of the dressing is reduced,and the encapsulation and fitting of the dressing are further realized by combining 3D printing technology.The challenge of continuous oxygen production with hydrogel dressings was completed,and the problem that diabetic wounds could not be sustained and could not be easily treated was solved.