Hasan Metineren

Objectives: Different materials are currently being used experimentally to accelerate cartilage healing and to obtain hyaline cartilage. We aimed to investigate the effect of platelet-rich fibrin on joint cartilage healing. Methods: Twenty rats were used in this study. platelet-rich fibrin was obtained from 4 rats, and the remaining 16 rats were randomly divided into two groups (4 and 8 weeks). Both knee joints were prepared, and an osteochondral defect was created at the femoral condyle in all rats. platelet-rich fibrin was placed into the osteochondral defect of the right knee, while the left knee joint was used as a control. Groups were sacrificed after 4 and 8 weeks, respectively. Results: According to the O'Driscoll score, there were no significant differences between the right and left knee scores in group 4 weeks (p = 0.820). However, the right knee scores were significantly different than the left knee scores in group 8 weeks (p < 0.001). Defects were completely filled with cartilage tissue after 8 weeks in the platelet-rich fibrin group. Conclusions: Similar to its role in various tissues, platelet-rich fibrin is an effective biomaterial that enhances the healing of osteochondral defects.

Ebselen is an organoselenium compound which has strong antioxidant and anti-inflammatory effects. We investigated the neuroprotective role of ebselen pretreatment in rats with experimental sciatic nerve ischemia-reperfusion (I/R) injury. Adult male Sprague Dawley rats were divided into four groups (N = 7 in each group). Before sciatic nerve I/R was induced, ebselen was injected intraperitoneally at doses of 15 and 30 mg/kg. After a 2 h ischemia and a 3 h reperfusion period, sciatic nerve tissues were excised. Tissue levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were measured. Sciatic nerve tissues were also examined histopathologically. The 15 mg/kg dose of ebselen reduced sciatic nerve damage and apoptosis (P < 0.01), levels of MDA, NO, and inducible nitric oxide synthase (iNOS) positive cells (P < 0.01, P < 0.05, respectively), and increased SOD, GPx, and CAT activities (P < 0.001, P < 0.01, P < 0.05, respectively) compared with the I/R group that did not receive ebselen. Conversely, the 30 mg/kg dose of ebselen increased sciatic nerve damage, apoptosis, iNOS positive cells (P < 0.01, P < 0.05, P < 0.001) and MDA and NO levels (P < 0.05, P < 0.01) and decreased SOD, GPx, and CAT activities (P < 0.05) compared with the sham group. The results of this study suggest that ebselen may cause different effects depending on the dose employed. Ebselen may be protective against sciatic nerve I/R injury via antioxidant and antiapoptotic activities at a 15 mg/kg dose, conversely higher doses may cause detrimental effects.