A New Type Of Corneal Epithelia Scaffold For Treatment Of Corneal Alkali Burn Wounds

Objective To evaluate the physical and biological properties of carboxymethyl chitosan(CMCTS)blended membranes and identify their application in the repair of corneal alkali burn wounds.Methods The blend membranes were prepared using carboxymethyl chitosan(CMCTS),gelatin(Gel)and hyaluronic acid(HA)at a mass ratio of 20?1?2.The transparency was examined by Multiskan Spectrum Spectrophotometer with different wavelengths(400~800 nm)of light.Then the blended membranes were implanted into subcutaneous tissue and skeletal muscle of SD rats.The in vivo degradability and histocompatibility of the membranes were determined by tissue section and HE staining.The toxicity in vivo were determined by weighing their kidneys and livers.Then the rabbit primary corneal epithelial cells were seeded onto the CMCTS blended membranes,and the cytocompatibility was evaluated by CFSE staining and SEM.Subsequently,the New Zealand rabbit models of corneal alkali burns were treated with the tissue engineering corneal epithelium as cell-carried group.The general observation,eye slit lamp microscope observation and histological immunofluorescence staining were used to evaluate the efficacy compared with the blank,model and membrane groups.Results The experimental results indicated that the CMCTS blended membranes had good transparency(over 80%).The films showed a high degradation rate and mild immune response in vivo,with relatively low in vivo toxicity in liver and kidney.The degradation time of the blended membranes was more than eight weeks in the subcutaneous tissues and four weeks in skeletal muscles.The CFSE staining and SEM observation exhibited that the films had good cytocompatibility to the rabbit primary corneal epithelial cells.In the treatment of the engineering corneal epithelium carrier transplanted to the corneal alkali burn wounds,basic completion of wound repair was observed in the experimental group 30 d after the surgery,while the repair effects of the membrane group were poor.In the model group,the corneal alkali burn could not be repaired by autologous cell proliferation and migration.Conclusion The CMCTS blend membrane based cell carriers with good physical and biological properties could be a promising tissue engineering corneal epithelium in treatment of corneal alkali burn,which provides experimental basis for the research of corneal disease treatment using tissue engineering method.