ObjectiveTo investigate Schwann cells whether survival and migration after transplanted to central nervous system for a long-term.MethodsThe Schwann cells of rat were expended in vitro, the part of them were labeled with 5'-bromodeoxyuridine (BrdU) and transplanted to rat's middle brain injured by electric needle stimulus, the others were labeled with Hoechst 33342, seeded to PLGA scaffold, and transplanted to rat's transected spinal cord. 8 and 11 months later, rat brain and spinal cord were taken out respectively, examined by BrdU immunohistochemistry and fluorescence microscope.ResultsBrdU positive cells could be seen after 8 months and migrated toward cerebral cortex. Hoechst 33342 positive cells could be identified in scaffold and transected spinal cord after 11 months under fluorescence microscope.ConclusionGrafted Schwann cells can survive in central nervous system for a long-term and migrate toward distance.

OBJECTIVETo test the immunosuppressive effect of cyclosporine (Cs) in a polymer placed in the anterior chamber of corneal allograft recipients.

METHODSWistar inbred rats with vascularized corneas were recipients of corneal allografts from Sprague-Dawley donor rats. Rats underwent penetrating keratoplasty and were divided randomly into four groups: untreated control animals (UCA); Cs-polymer anterior chamber recipients (CPA); co-polymer subconjunctival recipients (CPS); and Cs-olive oil drop recipients (COO). Grafts were examined by slit lamp every 3 days and clinical conditions were scored. Cs concentration in the aqueous humor was assayed at 1, 2, and 4 weeks. At 1, 2 and 4 weeks after transplantation, the operated eyes were collected for histopathological evaluation of the grafts.

RESULTSThe median survival time of the allografts was 8.2 +/- 1.48 days for the UCA group, 11.4 +/- 2.50 days for the CPS group, and 17.0 +/- 2.00 days for the CPA group. There was a statistically significant difference (P < 0.05) between survival time of the allografts in the animals of the CPA group compared to the other groups of graft recipients. Significantly higher concentrations of Cs were found in the eyes given an anterior chamber implant of Cs-polymer, compared to other treatment groups or untreated rats. A transient inflammatory response in the anterior chamber was observed in the CPA group.

CONCLUSIONSCs-polymer placed in the anterior chamber significantly prolongs corneal allograft survival time in a high risk corneal graft rejection model. This intraocular delivery system may be a valuable adjunct for the suppression of immune graft rejection.

Animals ; Aqueous Humor ; metabolism ; Corneal Transplantation ; Cyclosporine ; administration & dosage ; metabolism ; Drug Delivery Systems ; Graft Survival ; Immunosuppressive Agents ; administration & dosage ; Male ; Rats ; Rats, Wistar ; Transplantation, Homologous