Studies On Bacterial Cellulose/poly Vinyl Alcohol(BC/PVA) Hydrogel Composites As Tissue-engineered Corneal Stroma

PURPOSE:Corneal transplantation is the main method to cure the severe corneal disease,but the shortage of corneal donors restricts the corneal transplantation.Tissue-engineered cornea is a possible substitution,may help finding a way to solve the problem.In our present study,we strived to develop a new tissue-engineered corneal stroma for reconstructing the cornea.METHODS:For in vivo-testing,Bacterial cellulose/poly vinyl alcohol(Bacterial Cellulose/Poly Vinyl Alcohol;BC/PVA)and BC(Bacterial Cellulose;BC)was implanted intrastromal in New Zealand White rabbits,BC was used as a comparison.Slit lamp microscopy,in vivo confocal microscopic,H&E staining and immunofluorescent staining were performed in post-operation observation.Human corneal stroma cells(Human corneal stroma cells;hCSCs)were used as seeds to test the cytotoxicity of the materials.Cytotoxicity was assessed by CCK-8 and PCR,while hCSCs phenotypes were assessed using PCR.Fluorescent Calcein AM staining(Calcein AM staining),fluorescent F-actin staining and Scanning Electron Microscopy(SEM)was used to observe the hCSCs grown on the materials.RESULTS:After implanted the BC/PVA into corneal stroma for 4 weeks in rabbits,the cornea stayed almost transparent,and did not induce inflammation,sensitization or neovascular compared to BC under slit lamp microscopy observation.In vivo confocal microscopy showed significant activation of corneal stromal cells in the cornea implanted with bacterial cellulose,and a large amount of inflammatory exudation around the material,while the corneal stromal cells implanted with bacterial cellulose/poly vinyl alcohol could maintain a relatively resting state without inflammation,sensitization or neovascular.Histological sections also confirmed that there was little apparent rejection of corneas implanted with bacterial cellulose/poly vinyl alcohol.While,implanted into the cornea of bacterial cellulose,the adhesion of the material to the corneal stroma is unstable.Bacterial cellulose/poly vinyl alcohol used as a scaffold for inoculation of corneal stromal cells had little effect on the phenotype and proliferation of corneal stromal cells,showing good cellular compatibility.Compared with bacterial cellulose,cells grown on the surface of bacterial cellulose/poly vinyl alcohol have better cell morphology and growth state.CONCLUSIONS:These results demonstrated that the BC/PVA is well-tolerated in the cornea,and maybe an ideal substrate for tissue engineering corneal stroma.