ABSTRACT
Background Corneal transplantation is a primary method for the treatment of serious corneal diseases, but its application is limited because of the shortage of corneal donor.The study on tissue engineering corneal epithelium provides a new approach to corneal transplantation, and the biological scaffold materials for tissue engineering corneal epithelium is an issue of increasing concern.Bacterial cellulose membrane has been used in medical field,but its application in tissue engineering corneal epithelium deserves more researching.Objective This study was to evaluate the biocompatibility of bacterial cellulose membrane as a biological scaffold of tissue engineering corneal epithelium.Methods Corneal epithelium was isolated from 1 month-old New Zealand White rabbit.Corneal epithelial cells were cultured using explant method and identified by detecting the CK-3 expression using immunofluorescence technique.The second generation ceils were inoculated on bacterial cellulose membrane and culture plate, respectively, and the growth status of the cells were examined and compared under the optical microscope.The cell activity/toxicity test was performed by LIVE/DEAD cell staining kit at the third day after inoculation to evaluate the survival rate.The ultrastructure of the cell surface was examined under the scanning electron microscope.The study was performed in accordance with the ARVO Statement.Results Rabbit corneal epithelial cells grew well 1 week after primarily cultured with a cobblestone-like appearance and positive response for CK3 antibody.The cells on the bacterial cellulose membrane presented a round shape and regular arrangement and showed the green fluorescence for LIVE/DEAD test,with the survival rate 100％.Abundant leafy protrusion, microvilli and intercellular junction were seen under the scanning electron microscope.In addition, mitosis phase of cells and many filopodia between the cells and bacterial cellulose membrane were also exhibited.Conclusions Rabbit corneal epithelial cells can grow well in bacterial cellulose membrane.Bacterial cellulose membrane has good biocompatibility, indicating that bacterial cellulose membrane can be used as new biological material for tissue engineering corneal epithelium.
ABSTRACT
BACKGROUND:Nano-hydroxyapatite/bacterial celulose (nHA/BC) composite scaffolds prepared by nano-bionics method exhibit a structure and performance similar to natural bone. OBJECTIVE:To study the cytotoxicity and biocompatibility of nHA/BC composite scaffolds. METHODS:(1) Acute systemic toxicity test: nHA/BC leach liquor and normal saline were respectively injected intraperitonealy into Kunming mice. After 24, 48, 72 hours, the body mass of mice was recorded. (2) Sensitization test: nHA/BC leach liquor and normal saline were respectively injected subcutaneously into the back of Japanese white rabbits. With 72 hours of injection, edema and erythema were observed, and the experiment was done again at an interval of 14 days. (3) Pyrogen test: nHA/BC leach liquor and normal saline were respectively injected into the ear vein of Japanese white rabbits, and after injection, the body temperature of rabbits were determined. (4) Hemolysis test: Diluted rabbit anti-coagulant was added into nHA/BC leach liquor, normal saline and distiled water, respectively. (5) Passage 3 bone marrow mesenchymal stem cels from rabbits were co-cultured with nHA/BC materials, and then, cel proliferation, growth and adhesion on the material surface were observed. RESULTS AND CONCLUSION: nHA/BC composite scaffold was of no acute systemic toxicity, non-alergenic, no pyrogenic and hemolytic reactions; nHA/BC had a three-dimensional porous structure that was better for growth, proliferation and adhesion of rabbit bone marrow mesenchymal stem cels. These findings indicate that the nHA/BC composite scaffold has good biocompatibility and cytocompatibility.
ABSTRACT
BACKGROUND: The nano-hydroxyapatite/bacterial cellulose (nHAP/BC) nanocomposites has a good prospect of application in bone tissue engineering, and the bone tissue engineered materials and its degradation products Should have excellent compatibility. This study further assessed DAN synthesis cycle using flow cytometry on the basis of evaluating cell compatibility by metabolic 3-(4, 5-dim ethylthiazo 1-2-y 1) -2, 5-Dipheny 1-2H-tetrazolium (MTT) assay. OBJECTIVE: To evaluate the cytocompatibility of a new-pattern nHAP/BC nanocomposites and its residues. METHODS: Effects of nHAP/BC nanocomposites and its residues on morphclogicel changes in osteoblasts were observed using in vitro cell culture method. Effects of nHAP/BC nanocomposites and its residues on osteoblast growth and prclifera'don were evaluated by MTT assay. Cell cycle phase changes were detected using flow cytometry to evaluate matsdal effects on cell proliferation on molecular levels. RESULTS AND CONCLUSION: The nHAP/BC nanocomposites and its residues had neither remarkable effects on cell morphology, nor significant inhibition on osteoblast growth and proliferation. Test of MTT cytotoxicity showed that the average cell proliferation rate was over 80% after treated with the material and its residues, with the cytotoxity grade of 1 (non-toxic). Flow cytometry indicated that the rate of G_0/G_1 was reduced, and the rates of S, G2/M were increased, and the synthesis of DNA was increased, the cellular growth and repair in osteoblasts was accelerated. These indicated that nHAP/BC nanocomposites have good cytocompatibility, and it will be safe and prospected scaffolds in bone tissue engineering.