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In this study, three-dimensional hydroxyapatite/silk fibroin (HAp/SF) nanocomposite scaffolds were successfully prepared through layer solvent casting combined with the freeze-drying technique for tissue engineering applications. Various SF aqueous concentrations, ranging from 2.5% to 10%, were used to control the physicochemical properties of the prepared scaffolds. Biologic responses of the rat bone marrow stromal cells (rBMSCs) to the HAp/SF scaffolds were examined by culturing the cells within them. In addition, biodegradation and biocompatibility of the scaffolds were evaluated in vitro and in vivo, respectively. Among the prepared scaffolds, HAp/SF-2.5% was the most brittle sample and showed porous structure with lowest mechanical properties. The average pore diameters were 350 ± 67 and 112 ± 89 µm and decreased with the increase in the SF concentration from 5% to 10%, respectively. The pores formed in the scaffolds, made up of the 5% SF, were more uniform and regular than those of the scaffolds made up of 5% and 10% SF. The HAp/SF scaffolds did not change the rBMSCs viability and were not cytotoxic compared with the control sample. The scanning electron microscopy micrographs showed that the cells migrated into the pores and well attached to the scaffolds and their cytoplasm was extended in all directions, indicating a promising cell adhesion, high biocompatibility, and no cytotoxicity of the HAp/SF-5% nanocomposite scaffolds. Subcutaneous implantation of the HAp/SF-5% scaffolds in rat models suggested an excellent biocompatibility. All data obtained from this study suggest the potential use of the HAp/SF-5% for hard tissue engineering.

Background: Cyclophosphamide (CP) has been known as an anticancer drug with several side effects on various organs such as a male reproductive system that can cause infertility. Objective: To evaluate the possible combined effects of zinc oxide nanoparticles (nZno) and melatonin (Mel) on sperm parameters and histopathological changes of the testis in CP-treated rats. Materials and Methods: 42 adult male Wistar rats were divided into six groups. GI: control, GII: 60 mg/kg/wk CP, GIII and GIV, 10 mg/kg/wk Mel and 5mg/kg/wk nZno and GV: 5 mg/kg/wk nZno and 10 mg/kg/wk Mel were given 2 hr prior to CP injection, respectively,GVI: 5mg/kg/wk nZno and 10 mg/kg/wk Mel simultaneously. After 8 wk of treatment, rats were sacrificed and testis and epididymis were harvested for further evaluation. Results: The CP-treated group showed significant decreases in the body, testes and epididymis weights and sperm parameters (sperm count, viability, motility) with an increase abnormal sperms when compared with the control (p<0.001), as well as many histological alterations included decreased diameters of seminiferous tubules and Johnsen's Testicular Score (with degeneration, desquamation, multi-nucleated giant cell formation), whereas combined treatment (GV), showed more protective effects on CP-induced reproductive system damage compared with groups III or IV (p<0.001). Conclusion: These results suggest simultaneous administration of Mel and nZno have more effectively protections against CP-induced reproductive damage than Mel or nZno alone.

Background: Diabetes mellitus affects male reproductive system that is known to cause male infertility. Objective: The aim of the present study was to assess the effects of L-carnitine (LC) on sperm parameters, apoptosis of spermatogenic cells and testis histopathology in Streptozotocin-induced diabetic Rats. Materials and Methods: The study was carried out on 36 male Wistar adult rats (220 ± 30 gr) randomly divided into six groups (n = 6/each). 1 (Control); 2 (LC 100 mg/kg); 3 (Diabetic); 4, 5, and 6 (Diabetic + LC 50 or 100 or 200 mg/kg, respectively). Daily injections were administered intraperitoneally for 48 days. Then, rats were sacrificed, left testis and epididymis were harvested for sperm analysis and histopathology, morphometric and spermatogenesis assessments, and Tunnel assay. Results: L-carnitine in group 6 significantly decreased blood glucose level (p < 0.01) in comparison with group 3. L-carnitine in groups 5 and 6 significantly (p < 0.001) and dose-dependently increased the count, motility, viability, maturity, and chromatin quality of sperm and decreased the abnormal morphology of sperm in comparison with group 3. In groups 4, 5, and particularly 6, in comparison with group 3, there has been a significant difference in the increase of seminiferous tubule diameter, germinal epithelium height (p < 0.001), maturity quality of the seminiferous tubules (p < 0.001), decrease apoptosis of spermatogenic cells (p < 0.001), and testis tissue histopathological complications. Conclusion: The data obtained from the present study suggest that in the diabetic rats, LC decreases serum glucose level, improves the diameter and thickness of the epithelium of spermatogenic cells, reduces germ cells’ apoptosis, and improves epididymal sperm parameters. Therefore, it seems that LC plays an effective role in diabetes-induced infertility.

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