Biocompatibility between poly beta-hydroxyethyl methacrylate/porous hydrogel and electrospinning for wrapping orbital implant

BACKGROUND: Poly β-hydroxyethyl methacrylate (PHEMA)/hydrogel has been safely used to establish artificial cornea and lens; however, very little studies are related to orbital implant. Fiber produced by electrospinning technique has been widely used in biomedical fields, including tissue engineering scaffold, surface dressing, sustained drug release, medical bandage, and respiratory mask; however, very little reports are correlated to wrapping orbital implant. OBJECTIVE: To establish PHEMA/hydrogel combined with polyurethane membrane for wrapping orbital implant, and to study the biological features. DESIGN, TIME AND SETTING: A randomized controlled animal study was performed at the Department of Ophthalmology, the General Hospital of Chinese PLA from April to December 2007. MATERIALS: Ethylene glycol methacrylate compound with methyl methacrylate was mixed with NaCI solution to obtain porous hydrogel orbital implant; polyurethane membrane was established using electrospinning method. A volume fraction of 75% ethanol was used to make homologous sclera wrappage. METHODS: Circled digit one Stimulus test: A total of 18 Wistar rats were randomly divided into two groups. Unhairing area sizing 4 mm x 4 mm was selected from bilateral spine. One area was wrapped with hydrogel, and the other area was wrapped with polyurethane membrane. Four hours later, sticking patch was removed, and erythema and edema were scored. Circled digit two Flow cytometry: An addition of 30 Wistar rats were randomly divided into three groups of which orbital implants were wrapped with polyurethane membrane-coated PHEMA/porous hydrogel, homologous sclera-coated PHEMA/porous hydrogel, and porous hydrogel, respectively. The whole blood was drawn from caudal vein at day 1 before operation, and at days 1, 7, 14, 21, and 28 after operation to detect percentage between T lymphocyte subgroup CD4+ and CD8+. MAIN OUTCOME MEASURES: Erythema, edema, and CD4 +/CD8+. RESULTS: Stimulus test indicated that both materials could not induce stimulus to the skin, which was coincidence with the criteria. Flow cytometry demonstrated that there was no significant difference in CD4+/D8+ among each group at days 14, 21, and 28 after operation compared to before implantation (P > 0.05). Both granuloma and ocular prosthesis discharge were not observed in the orbital implants. CONCLUSION: The polyurethane membrane-coated hydrogel orbital implant has good histocompatibility, and can be transplanted into the eyes.