In addition, immunohistochemical evaluation was conducted to detect tyrosine hydroxylase (TH) antibodies in the corpus striatum and dopaminergic neurons in the substantia nigra pars compacta (SNpc). days. MSCs were isolated from the mononuclear cell fraction of pooled bone marrow from C57BL/6 mice and incubated with micrometer-sized iron oxide (MPIO) particles. For IN administration, we used a 20 l of 5105 cell suspension. Neurobehavioral assessment of the mice was performed, and after sacrifice, brain sections were stained with Prussian blue to detect the MPIO-labeled MSCs. In addition, immunohistochemical evaluation was conducted to detect tyrosine hydroxylase (TH) antibodies in the corpus striatum and dopaminergic neurons in the substantia nigra pars compacta (SNpc). The neurobehavioral assessment revealed progressive deterioration in the locomotor functions of the rotenone group, which was improved following MSC administration. Histopathological evaluation of brain sections in the rotenone+MSC group revealed successful delivery of MSCs, evidenced by positive Prussian blue staining. Furthermore, rotenone treatment led to significant decrease in dopaminergic neuron number in SNpc, as well as similar decrease in the corpus striatum fiber density. By contrast, in animals receiving IN administration of MSCs, the degeneration caused by rotenone treatment was significantly counteracted. In conclusion, the present study validated that IN delivery of MSCs may be a potential safe, easy and cheap alternative route for stem cell treatment in neurodegenerative disorders. and studies failed to show similar efficacy in humans, leading to high attrition rates of novel CNS active drugs in clinical trials (11). The main reason for such failure is the presence of the BBB, which prevents the passage of the right concentration of the drug to the target tissue (12). One approach for resolving this issue is targeted intranasal (IN) delivery, which is an applicable method used to circumvent BBB rather than attempting to cross it (13). The nasal passage is the only direct connection between the brain and the external environment. This connection occurs through the extension of axons from the olfactory bulb to the nose, allowing direct contact with the external environment. Another potential route is Calcitriol D6 the nose to brain pathway, which is a controversial pathway suggesting the passage of medication through the deep structures in the nose that are innervated by cranial nerves (14). Based on this pathway, the IN route has been used Calcitriol D6 for the delivery of a variety of agents for the treatment of different CNS conditions. For instance, drugs delivered using IN delivery system include growth factors, neuropeptides, genes and small molecules Calcitriol D6 (9). Notably, previous animal studies showed the successful IN delivery of mesenchymal stem cells (MSCs) to the brain. In addition, animal models of Parkinson’s disease have been successfully treated through IN administration of L-DOPA (15). Based on these previous findings, Rabbit Polyclonal to Mouse IgG the present study aimed to investigate the use of Calcitriol D6 the IN Calcitriol D6 route for administration of MSCs in a mouse model of PD. Materials and methods Rotenone mouse model and stem cells administration A total of 30 B57BL/6 mice (age, 8 weeks; weight, 16C20 g) were provided by the Medical Experimental Research Center of Mansoura University (Mansoura, Egypt) and maintained in conditions of 21C23C, with a humidity of 40C55% and a 12 h dark/light cycle. All animal experiments were performed according to the Guidelines for the Care and Use of Mammals in Neuroscience (2003), and were approved by the Ethical Committee for research at Mansoura University. All efforts were made to minimize animal suffering and to reduce the number of animals used. A PD model was developed in mice through the intraperitoneal administration of 3 mg/kg/day time body weight rotenone (Sigma-Aldrich, St. Louis, MO, USA), for 60 consecutive days. The mice were divided into three organizations (10 mice in each) as follows: Control group, which received daily intraperitoneal injection of 0.5% carboxymethyl cellulose (El-Nasr Chemicals Co., Cairo, Egypt); PD model group (rotenone group), receiving rotenone (3 mg/kg body weight) dissolved in 0.5% carboxymethyl cellulose intraperitoneally; and rotenone+MSC group, which received rotenone administration similarly to the PD model group, followed by IN bone marrow MSCs derived on day time 60. All animals were sacrificed by perfusion through the aorta with 50 ml of 10 mM phosphate-buffered saline (PBS),.