الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Any person’s physical, psychological, and emotional makeup is mainly dependent on a normal activity of his facial nerve. Facial disfigurement can affect all these components and can result in social and vocational difficulties. Facial palsy can be defined as a kind of paralysis affecting facial muscles. It is termed Bell’s palsy if it is unilateral. It may occur due to trauma to the facial nerve, infections as herpes zoster, neoplastic lesions, or unknown cause. It may be also associated with metabolic and systemic diseases as hypertension, toxicity, amyloidosis, alcoholism, auto-immune diseases and diabetes mellitus Mesenchymal stem cells may be more beneficial in the management of various neurologic diseases, in comparison with other types of stem cells. The bone marrow cells are readily accessible, overwhelming the risks of extracting neural stem cells from the central nervous system, and granting a renewable population. Bone marrow stem cells (BMSCs) grow rapidly in culture, and differentiate into neurons exclusively with use of a simple protocol Magnetic targeting systems with magnetically labeled cells have been evaluated as a more efficient and effective method for the delivery of cells to target sites. These systems depend on loading stem cells with magnetic nanoparticles and attracting them to particular regions inside the body by utilizing an external magnetic field .The present study was designed to perform a biological evaluation of the neuronal regeneration capabilities of bone marrow stem cells with or without supermagnetic iron oxide nanoparticles, as a magnetic targeting tool, after facial nerve neurolysis in albino rats. Materials and Research Methods: This study was carried out on 38 male rats, weighing between 200-300 g. The animals were randomly divided into four groups as follows: Negative control group: (number 2) where they were not exposed to any surgical procedure. The remaining rats were then injected with 0.01 ml of 90% ethanol into each rat intrafascularly of the right facial nerve trunk. An assessment of right facial nerve activity was performed one week after surgery by observing the movement of the right eyelid with air infflation. Complete neurodegeneration was considered with complete loss of eyelid movement, then the animals were divided into 3 groups, each group containing 12 rats: The first group: (number 12): the rats were intravenously injected with 2.0 ml of DMEM, and it was considered the positive control group. The second group: (number 12) rats were intravenously injected with (10) 6 of bone marrow stem cells in 0.2 ml of DMEM Third group: (number 12) mice were intravenously injected with (10) 6 bone marrow stem cells in 0.2 ml of DMEM with superparamagnetic iron oxide nanoparticle Six rats from each group were euthanized at the end of the fourth week of treatment, and the rest of the animals were slaughtered at the end of the eighth week of treatment at the end of the experiment Isolation and transplantation of stem cells derived from bone marrow rats tissue samples were collected from four white, disease-free rats weighing from 80 to 150 g. Samples were processed aseptically, then cells were cultured in DMEM—F 12 supplemented with 10% fetal bovine serum, 1% streptomycin, penicillin and amphotericin. The isolated cells were maintained in the incubator at 37°C and 5% CO2 humid air, then the cells were treated with trypsin and partially cultured. Association of bone marrow-derived stem cells with superparamagnetic iron oxide nanoparticles A sample of 25 μg/ml Fe/ml supermagnetic iron oxide nanoparticles and 375 ng/ml poly-L-lysine was added to the bone marrow-derived stem cells. Cells were cultured for 24 h at 37 °C in an incubator at a concentration of 5% CO, then the medium was discarded. A circular neodymium magnet (0.57 Tesla, 2 x 5 mm) was placed on the face of each mouse just below the right ear at the surgical site to attract stem cells that were bound to superparamagnetic iron oxide nanoparticles. Magnetic resonance imaging was performed to ensure that the cells reached the surgical site. Histological and immunohistochemical evaluation: • Examination by light microscopy: the samples were fixed in neutral formalin for 24 hours, then placed inside wax cubes, and the samples were cut in the form of slices to be stained with the following dyes: Hematoxylin and Eosin stain. . Immunostaining: (anti-S100B). Electron microscopy examination statistical analysis: The results have been included digitally in a table to be statistically analyzed using the program (SPSS version 20.0 .). Results: Negative control group: Histological examination and electron microscopy results showed that the facial nerve trunks retain their normal structure, and the histochemical examination showed a slight reaction of the dye. The first group: Histological examination and electron microscopy results showed severe vascular degeneration in nerve fibers and Schwann cells with a large number of areas of edema after four weeks of treatment, which subsided slightly after the eighth week. The histochemical examination of the anti-S100B immunostaining showed a slight reaction after four weeks of treatment, which did not change much by the end of the eighth week. The second group: Histological examination and electron microscopy results showed an improvement in the remodeling and distribution of nerve fibers, Schwann cells and myelin sheathes, in addition to an increase in blood vessel formation after four weeks of treatment. This improvement increased to almost the normal structure of the nervous tissue by the end of the eighth week. The histochemical examination showed a moderate anti-S100B reaction after four weeks of treatment, which increased to severe after the end of the eighth week. The third group: Histological examination and electron microscopy results showed similar improvement to the second group in nerve fibers and Schwann cells after the fourth week of treatment, which decreased somewhat by the end of the eighth week. The histochemical examination also showed a severe reaction to the immunoglobulin anti-S100B after four weeks of treatment, which decreased to mild after the end of the eighth week. Conclusion: Based on the adopted methodology and the results obtained, the following can be concluded: Stem cells derived from bone marrow alone have better ability to regenerate nerve fibers than stem cells derived from bone marrow and accompanying superparamagnetic iron oxide nanoparticles as a means of magnetic targeting. Recommendations: Treatment with neurolysis followed by BMSCs injection may be a promising therapy for treatment of peripheral nerve disorders as spasticity, which needs to be tested in further experimental studies before it could be considered as a novel and effective therapy. Further preclinical research is recommended for the use of stem cells derived from bone marrow following neurolysis as a new treatment for spasticity associated with nervous system diseases. It is also recommended to conduct more scientific research to confirm the bio-efficiency of using superparamagnetic iron oxide nanoparticles with stem cells derived from bone marrow as a means of magnetic targeting of neural tissues in the long term.