Bone marrow stem cells with or without superparamagnetic iron oxide nanoparticles as a magnetic targeting tool: Which is better in regeneration of neurolysed facial nerve? An experimental study.

Aim: This study was performed to evaluate neural regenerative capacities of bone marrow stem cells (BMSCs) with or without superparamagnetic iron oxide nanoparticles (SPIONs) as a magnetic targeting tool after neurolysis of the facial nerve (FN) in albino rats. Methods: Thirty-eight male albino rats were selected. Two of them were euthanized for normal FN histology assessment. Thirty-six rats were injected with ethanol in the FN nerve for neurolysis induction and assessed one week post-operatively by eye blinking test. Animals were divided into three groups, each containing twelve rats: Group I (positive control) was injected with Dulbecco Modified Eagle's medium (DMEM-F12), group II was injected with BMSCs in DMEM-F12, and group III was injected with BMSCs in DMEM-F12 with poly l-lysine coated SPIONs (0.5 mmol/mL). Monitoring of SPIONs in the rat's body was carried out by MRI. A circular neodymium magnet N52 (0.57 T, 2 × 5 mm) was placed on each rat in group III just below the right ear at the site of surgery to attract SPIONs labeled BMSCs, left in place for 24 h, and then removed. From each group, six rats were euthanized at the end of the 4th and 8th week of treatment, respectively. The right FN trunks were extracted for routine histological examination using H&E stain. Immunohistochemical examination by anti-S100B was performed to characterize the thickness of the myelin sheath formed by the Schwann cells. Ultra-structural examination was performed to study changes in axons, myelin sheaths, and Schwann cells. Results: Regeneration of nerve fibers, Schwan cells, and myelin sheaths was better in group II than in groups I and III histologically, immunohistochemically, and ultra-structurally. Conclusion: BMSCs alone could ameliorate FN regeneration better than magnetic targeting treatment using BMSCs labeled with SPIONs.

Biological Impact of Alloplastic Bone Graft vs Bovine Xenograft and Allograft Materials in Bone Healing: An Experimental Study.

AIM: This study aims to compare the performance of beta-tricalcium phosphate with calcium sulfate (ß-TCP/CS) vs a bovine xenograft, freeze-dried mineralized allograft, and spontaneous healing in surgically prepared bone defects in rabbit tibia. MATERIALS AND METHODS: The grafting materials were implanted in three out of four standardized monocortical bony defects, 3-mm diameter and 3-mm deep, in rabbit tibia while one defect was left empty for spontaneous healing as a control group. Twelve rabbits were euthanized at 2 and 6 weeks after surgery. The bone tissue specimens were histologically evaluated using hematoxylin and eosin, Masson's trichrome and osteoprotegrin (OPG) immunohistochemical staining. Results were quantitatively evaluated. RESULTS: An enhancement of bone healing was noticed in the defects grafted with ß-TCP/CS compared with all other groups at 2 and 6 weeks after surgery as it showed significant increase in OPG expression and a significant decrease in the amount of collagen at 6 weeks after surgery. The residual grafted particles were the least with ß-TCP/CS at 6 weeks after surgery. CONCLUSION: The ß-TCP/CS grafting material is a promising bioactive alloplastic bone substitute as it proved to be biocompatible, osteoconductive, and bioresorbable bone substitute. CLINICAL SIGNIFICANCE: The ß-TCP/CS grafting material can be used for guided bone regeneration resulting in pronounced high-quality bone which aids in oral and maxillofacial reconstruction.

Role of bone marrow-derived mesenchymal stem cells on the parotid glands of streptozotocin induced diabetes rats.

The functional insufficiency of salivary glands constitute the common oral complaints in both type 1 and type 2 diabetes mellitus. The treatment with stem cell could decrease diabetic-induced hyposalivation and improve the quality of life for patients. OBJECTIVE: The current study designed to assess the biological outcome of systemic injection of stem cells on the parotid salivary gland in streptozotocin induced diabetic. METHODS: Twenty-four albino rats received intra-peritoneal injection of 50 mg/kg streptozotocin for induction of diabetes and were divided into two groups (n = 12): Group I (control) were kept without any manipulation, Group II received intravenous injection of 1×106 of mesenchymal stem cells of bone marrow derived for two days. All rats were sacrificed at 1, 3 weeks, then the parotid glands were isolated, fixed and processed for Heamatoxylin and Eosin examination, immunohistochemical staining for aquaporin-5. RESULTS: group I groups showed intracellular cytoplasmic vacuoles and focal loss of salivary architecture, while group II showed maintenance of gland architecture. Immunohistochemical examination of aquaporin-5 showed significant difference between the two groups. CONCLUSION: bone marrow derived stem cell treatment considers as an improved methods in prevention and treatment of diabeticinduced hyposalivation.