ABSTRACT
BACKGROUND:How to improve the stability of artificial cornea in the host and reduce the complications is the current key issues to be solved.Therefore,looking for an ideal biocompatible scaffold material is still the focus of the study.OBJECTIVE:To explore the biocompatibility of nano-hydroxyapatite (nHA)/polyvinyl alcohol (PVA) porous composite hydrogel and pure PVA hydrogel as artificial corneal materials.METHODS:Inverted microscope was used to observe cell growth of rabbit corneal stromal fibroblasts when cultured with nHA/PVA composite hydrogel extract or PVA extract for 48 hours.MTT method was used to detect the relative proliferation rate of rabbit corneal stromal fibroblasts cultured with nHA/PVA composite hydrogel extract or PVA extract.Systemic toxicity,allergies,pyrogen reaction and deaths were observed in New Zealand white rabbits at 48 hours after artificial corneal implantation.ELISA and hematoxylin-eosin staining were used to detect changes in serum inflammatory factors at 4 weeks after artificial corneal implantation.Slit-lamp examination was performed to observe corneal or conjunctival hyperemia/edema and corneal neovascularization at 1-4 weeks after corneal implantation.Corneal neovascularization time and neovascularization area were detected after the two materials were implanted.RESULTS AND CONCLUSION:The cells were sparse and grew slowly at 48 hours after culture in nHA/PVA composite hydrogel or PVA extract as compared with the blank control group.The cell growth in the nHA/PVA composite hydrogel group was better than that in the PVA group.The relative cell proliferation rate was significantly decreased at different time after culture in nHA/PVA composite hydrogel or PVA extract compared with the blank control group (P ＜ 0.05),and the relative cell proliferation rate in the nHA/PVA composite hydrogel group was significantly higher than that in the PVA group (P ＜ 0.05).There were two rabbits appearing to have allergic reaction,but no one presenting with pyrogen reaction and death in the nHA/PVA composite hydrogel group;and there were two rabbits appearing to have allergic reaction,and two appearing to have pyrogen reaction,but no death in the PVA group at 48 hours after implantation.The inflammatory factor levels were increased significantly in the nHA/PVA composite hydrogel group and PVA group compared with the control group (P ＜ 0.05),and inflammatory infiltration was milder in the nHA/PVA composite hydrogel group than the PVA group at 4 weeks after implantation (P ＜ 0.05).Corneal neovascularization appeared later in the nHA/PVA composite hydrogel group than the PVA group,and the neovascularization area was also smaller in the nHA/PVA composite hydrogel group than the PVA group (P ＜ 0.05).Taken together,the biocompatibility of nHA/PVA composite hydrogel is superior to that of pure PVA when they are used as artificial cornea materials,which provides a scientific basis for artificial cornea material innovation and extensive clinical application.
ABSTRACT
It is important that the oral hospital establish a guarantee system of medical graduation clinical practice quality. Having experienced clinical education for many years,the hospital has formed a system in order to achieve objective management and process management organic unification,which can gradually promote the clinical practice quality.