Co- transplantation of bone marrow stromal cells with schwann cells evokes mechanical allodynia in the contusion model of spinal cord injury in rats

Several studies have shown that, although transplantation of neural stem cells into the contusion model of spinal cord injury [SCI] promotes locomotor function and improves functional recovery, it induces a painful response, Allodynia. Different studies indicate that bone marrow stromal cells [BMSCs] and Schwann cells [SCs] can improve locomotor recovery when transplanted into the injured rat spinal cord. Since these cells are commonly used in cell therapy, we investigated whether co-transplantation of these cells leads to the development of Allodynia. In this experimental research, the contusion model of SCI was induced by laminectomy at the T8-T9 level of the spinal cord in adult female wistar rats [n=40] weighting [250-300g] using the New York University Device. BMSCs and SCs were cultured and prelabeled with 5-bromo-2-deoxyuridine [BrdU] and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate [DiI] respectively. The rats were divided into five groups of 8 including: a control group [laminectomy only], three experimental groups [BMSC, SC and Co-transplant] and a sham group. The experimental groups received BMSCs, SCs, and BMSCs and SCs respectively by intraspinal injection 7 days after injury and the sham group received serum only. Locomotion was assessed using Basso, Beattie and Bresnahan [BBB] test and Allodynia by the withdrawal threshold test using Von Frey Filaments at 1, 7, 14, 21, 28, 35, 42, 49 and 56 days after SCI. The statistical comparisons between groups were carried out by using repeated measures analysis of variances [ANOVA]. Significant differences were observed in BBB scores in the Co- transplant group compared to the BMSC and SC groups [p< 0.05]. There were also significant differences in the withdrawal threshold means between animals in the sham group and the BMSC, SC and the Co-transplant groups [p<0.05].BBB scores and withdrawal threshold means showed that co-transplation improved functioning but greater Allodynia compared to the other experimental groups. The present study has shown that, although transplantation of BMSCs, SCs and a combination of these cells into the injured rat spinal cord can improve functional recovery, it leads to the development of mechanical Allodynia. This finding indicates that strategies to reduce Allodynia in cell transplantation studies are required

role of biodegradable engineered nanofiber scaffolds seeded with hair follicle stem cells for tissue engineering

The aim of this study was to fabricate the poly caprolactone [PCL] aligned nanofiber scaffold and to evaluate the survival, adhesion, proliferation, and differentiation of rat hair follicle stem cells [HFSC] in the graft material using electrospun PCL nanofiber scaffold for tissue engineering applications. The bulge region of rat whisker was isolated and cultured in DMEM: nutrient mixture F-12 supplemented with epidermal growth factor. The morphological and biological features of cultured bulge cells were observed by light microscopy using immunocytochemistry methods. Electrospinning was used for production of PCL nanofiber scaffolds. Scanning electron microscopy [SEM], 3-[4, 5-di-methylthiazol- 2-yl]-2, 5-diphenyltetrazolium bromide [MTT] assay, and histology analysis were used to investigate the cell morphology, viability, attachment and infiltration of the HFSC on the PCL nanofiber scaffolds. The results of the MTT assay showed cell viability and cell proliferation of the HFSC on PCL nanofiber scaffolds. SEM microscopy images indicated that HFSC are attached, proliferated and spread on PCL nanofiber scaffolds. Also, immunocytochemical analysis showed cell infiltration and cell differentiation on the scaffolds. The results of this study reveal that PCL nanofiber scaffolds are suitable for cell culture, proliferation, differentiation and attachment. Furthermore, HFSC are attached and proliferated on PCL nanofiber scaffolds