The Preparation And Performance Study Of Skin Repair Materials Based On Regenerated Cellulose

With the development of material science and tissue engineering, skin repair materialshave been intensively studied. It is well known that materials made of single chemical ornatural polymer are hard to satisfy the requirements for different wound repair, thusdeveloping composite materials, which takes advantages of combined properties fromdifferent polymers, becomes a research hotspot in skin tissue engineering. This work aimed toprepare regenerated cellulose (RC)/collagen (Col) composite materials, combine the highmechanical strength and hydrature, good gas-liquid permeability of RC with the excellentbiocompatibility and biodegradability of Col, study their physic-chemical properties, andevaluated their potential application as wound dressings and skin repair scaffold.Firstly, we prepared RC film by freezing-thawing-acid curing method. Themicrostructure of RC film and its properties such as pore sizes and porosity, mechanicalproperty, water holding capacity, equilibrium-swelling ratio, air permeability, water retentionproperties as well as biocompatibility were tested to evaluate its potentiality as a skin repairmaterial. The experimental results showed that RC film had a3-Dimensional porous structurewith the porosity of95%and pore size ranging from20nm to200nm. RC film displayedhigh mechanical properties, high water holding capacity, and good air permeability and waterretention properties. Its good biocompatibility could promote cellular adhesion and growth.Furthermore, the structural characteristics of RC/Col combined dressing, which wasgenerated by NaIO4modification, were investigated by FT-IR and SEM. The results of SEMshowed that RC/Col showed a refined porous morphology, with its surface was covered bycollagen. In addition, the composite dressing showed novel mechanical properties (the strainwas55.50MPa, the stress was5.45%), good equilibrium-swelling ratio (256%), good airpermeability (640g·m-2·d-1) and excellent water retaining property (26.12%, after5days).The adhesion and proliferation of cell culture on RC/Col revealed that cell adhered to thesurface firmly, the morphology of cell was extended, and presented a proliferative trend.Taken together, RC/Col composite dressing could be a poteintial material for wound repair.Finally, we prepared a bilayer scaffold by amination modification of RC and crosslinkingof Col for skin tissue engineering application. The microstructure, mechanical properties,equilibrium-swelling ratio, biodegradation, and biocompatibility were investigated. Theexperimental results showed that the dense outer layer of RC film has good mechanicalproperties, wound compliance, permeability and resistance of bacteria, which could provide amoist environment for wound repair. The porous inner layer of Col sponge could promotecellular proliferation and differentiation effectively. Its aperture size (30~120μm) wassuitable for cell implantation and the degradation cycle meet the requirement of wound repair and healing. To sum up, the bilayer scaffold is a good base material for the preparation oftissue-engineered skin, could develop more advantageous artificial skin.