RESUMEN
Background Hyaluronic acid is a mucopolysaccharide existing in extracellular matrix and having good biocompatibility.Using chemical crosslinking method can improve the physical properties of the material,so cross-linked hyaluronic has potential clinical application value.Objective The present study was to evaluate the histocompatibility and biological security of cross-linked hyaluronic acid as ophthalmic implant material.Methods Cross-linked hyaluronic acid implant material was prepared according to the criteria of Biological Evaluation of Medical Devices (GB/T16886.5-2003).Eighteen 8-week-old male New Zealand white rabbits were randomized into the experimental group and the control group.Cross-linked hyaluronic acid material with 5.0 mm diameter was implanted into corneal stroma interlaminationally in the experimental group,and only corneal stromal interlaminational pocket was made without any implanting material in the control group.Biological response of cornea was assessed in vivo from 1 week through 3 months after operation by slit lamp microscope.The corneas were obtained 2 weeks,1 month and 3 months respectively for histopathological examination.Mouse embryonic fibroblasts were cultured in cross-linked hyaluronic acid film plate,medical silicone material culture plate and regular culture plate respectively for 24 hours,and the cell growth state and morphology were observed under the inverted microscope and scan electron microscope.MTT assay was used to test the relative growth rate of the cultured cells 48 hours after cultured using extracted liquid of hyaluronic acid implant material.Results Cross-linked hyaluronic acid implant material showed a well healing to the corneas of rabbits during the observation duration,without obvious inflammatory response and neovascularization.The arrangement of stromal fibers was uniform in order,and no infiltration of inflammatory cells was seen under the light microscope.The cells grew well after cultured with cross-linked hyaluronic acid film and regular medium for 24 hours,but in the silicone culture group,fewer of adherent cells and more floating cells were found.The relative growth rate of the cells was 87.50％ 48 hours after cultured with extracted liquid of hyaluronic acid implant material.Conclusions The cross-linked hyaluronic acid material has good histocompatibility and biological security in rabbit cornea tissue.