Preparation And Properties Of Bio-based Hydrogel Composite Functional Wound Dressing

When the skin is injured,the original skin protection mechanism is destroyed and the injured skin requires extra protection.Wound dressing materials protect the skin from secondary damage while accelerating the recovery of skin barrier function.Therefore,the preparation of new functional wound dressings is imperative in the development of modern medical technology.To this end,various biological materials have been used for rapid healing of wounds,including electrospun nanofiber membranes,porous foams,biocompatible membranes and functional hydrogels.Among them,non-woven materials have attracted great interest because of its versatility to produce fibrous structures with antibacterial properties and rapid hemostasis,creating a highly breathable environment around the wound area to promote healing.At the same time,hydrogels have also attracted attention because their natural porous structure and high-water absorption can absorb a large amount of exudate or blood.It creates a moist wound to restore the environment,as a microbial barrier,maintaining a considerable level in the skin defect.It is humid and maintains good water permeability.And the hydrogel dressing has self-healing ability,which can relieve the pain of the patient to some extent.Here,we designed a bio-fiber nonwoven material and hydrogel composite functional wound dressing,integrating the breathability of the hemp-punched nonwoven fabric of the hemp/viscose fiber;the silk fibroin nanofiber film prevention Liquid diffusion to prevent bacterial invasive properties;porous structure of biomass fiber nonwoven,hydrogel with superabsorbent and self-healing properties to meet the growing skin damage requirements,in line with the repair and skin regeneration that new wound dressing materials should have advantage.The research work of this subject includes the following parts:Firstly,when selecting biomass fiber to construct non-woven materials,it is important to evaluate the characteristics and shortcomings of hemp fiber produced in Shandong,Select the hemp fiber that meets the requirements of materials and processing technology.The surface microstructure of hemp fiber and viscose fiber was characterized by SEM.Biomass fiber construction Non-woven material has a design surface density of 50 g/m²and uses 7 kinds of mixed ratio of hemp/viscose fiber 0/100,20/80,40/60,50/50,60/40,80/20 and 100/0,carded into a net,spunlaced.The basic physical and mechanical properties and moisture permeability of different blends compared to spunlaced nonwovens were tested.The hemp/viscose spunlaced nonwoven fabric with blending ratio of 60/40 was selected,surface morphology analysis,structural analysis,pore size distribution analysis and water retention performance analysis.Thus,a hemp-based spunlaced nonwoven fabric having a moderate thickness required for the dressing and having physical properties such as softness,gas permeability,moisture permeability and water retention property is obtained.Secondly,in Calcium chloride?CaCl₂??purity 99%?-formic acid?FA??purity 98%?dissolution system,the regenerated SF nanofiber membrane was prepared by electrospinning method.The dissolution mechanism of SF fiber was discussed.The rheological properties of the regenerated SF solution were tested and analyzed.The surface morphology and structure of the regenerated nanofilm were tested by different conditions.Analysis of water absorption and moisture permeability.The results show that the salt-acid binary dissolution system dissolves SF by damaging the crystal structure,adding 75%alcohol,and the structure of SF fiber changes from random coil to?-fold conformation.The SF nanofiber membrane has weak water absorption and strong moisture permeability.Thirdly,preparation of carboxymethyl cellulose and cellulose?CMC/CEL?water with superabsorbent and self-healing behavior by chemical crosslinking in sodium hydroxide/urea/water?NaOH/urea/H₂O?solution gel.Wherein CMC powder is mixed in CEL solution at a ratio of CMC/CEL 5:5,6:4,7:3,8:2,9:1 and 10:0?w/w?,coded as CCE55,CCE64,CCE73,CCE82,CCE91 and CCE10.The structure and properties were characterized by SEM,FTIR spectroscopy,XRD and DTG.The results show that all cellulose-based hydrogels exhibit a uniform porous structure and a certain miscibility.Cellulose-based hydrogels can be made into a variety of shapes and can withstand a variety of deformations,including large stretching,knotting and compression.A larger porosity indicates a larger pore size of the hydrogel.The maximum degree of swelling of the chemically crosslinked cellulose-based hydrogel is close to 1500?%?,which is significantly higher than that of the hydrogel prepared from the cellulose derivative.As the concentration of the NaCl solution increases,the hydrogel ionization decreases,the viscosity increases,and the water absorption decreases.The hydrogel can be biodegraded,and as the CEL content increases,the rate of degradation of the hydrogel decreases.At the same time,cellulose-based hydrogels can heal autonomously at ambient temperature without any external irritation.With the superior performance of superabsorbent and self-healing,the development of cellulose-based hydrogels has great application value.Fourthly,the research concept of hemp-based cellulose hydrogel composite functional wound dressing.The wound dressing is designed as a three-layer structure and is divided into a protective layer,a contact surface layer,and a hydrogel coating.The protective layer is a hemp-based nonwoven fabric prepared by using a spunlace processing technology,and the designed basis weight is 50 g/m²;the contact surface layer is an SF nanofiber membrane spun by electrospinning,and the SF nanofiber is uniformly spread on the water.On the punctured nonwoven fabric,the fiberizing property is good.The superabsorbent and self-healing hydrogel is then applied to the SF nanofiber membrane and the nonwoven fabric composite functional wound dressing base fabric to form the final functional wound dressing,which has moisturizing,antibacterial and liquid diffusion prevention.Multiple functions such as sex,water absorption,and self-healing.The functional wound dressing has a grammage of 51.62 g/m²,a thickness of 1.181 mm,and a moisture permeability of 284.201±27.39 g/m²·h^-1.