Effect of Bone Marrow Derived Mesenchymal Stem Cells on Healing of Induced Full-Thickness Skin Wounds in Albino Rat

BACKGROUND AND OBJECTIVES: Mesenchymal stem cells have delivered new approaches to the management of wound healing in severe skin injuries. This work was planned to evaluate the effect of bone marrow-derived mesenchymal stem cells (BMSCs) on healing of induced full thickness skin wounds in albino rats using topical & systemic injections. METHODS AND RESULTS: Forty adult male albino rats were classified into 2 groups after induction of full thickness skin wound; untreated group and stem cell-treated group. The latter was further subdivided into topically and systemically treated ones. BMSCs were isolated & labeled by PKH26 before injection. Healing of wounds was evaluated grossly. Skin biopsies were obtained one & three weeks after wound induction. Sections were stained with Hematoxylin & Eosin, Masson's trichrome and immunohistochemichal stain for vascular endothelial growth factor (VEGF). Epidermal thicknesses and mean area percent of both collagen fibers & VEGF immunopositive cells were measured using image analyzer & results were subjected to statistical analysis. PKH26 fluorescent-labeled cells were found in the regenerated epidermis, hair follicles and dermis in BMSCs-treated groups. By the end of the third week, the wounds of BMSCs-treated groups showed full regeneration of epidermis, re-organization of collagen and decrease in VEGF immunopositive cells. Delayed wound healing was seen in 20% of systemically treated rats. Significant increase in the mean area percent of collagen fibers was detected in topically treated group. CONCLUSIONS: Both methods of BMSCs injection were effective in healing of full thickness skin wound but topical method was more effective.

Effect of human cord blood-derived stem cells on induced diabetic retinopathy in adult albino rat: histological and immunohistochemical study

Diabetic retinopathy is a leading cause of blindness in adults. Recent developments in stem cell field have widened the prospects of applying cell-based therapies to regenerate ocular tissues. This study was done to explore the potential effect of human cord blood-derived stem cells on induced diabetic retinopathy in adult albino rats. This study was performed on 26 adult male albino rats. Animals were randomly divided into four groups. Group I [control group]: five control animals each received single intraperitoneal injection of citrate buffer. Group II: seven animals in whom diabetes was induced by single intraperitoneal injection of streptolotocin and animals were killed 4 weeks later. Group III: seven animals in whom diabetes was induced the same way as in group II and animals were killed 8 weeks later. Group IV: seven animals with diabetes were injected with ferrous oxide-labeled cord blood-derived stem cells 4 weeks after induction of diabetes and were killed 4 weeks after stem cell injection, All sections from retina of all groups were subjected to Haematoxylin and eosin, Prussian blue staining and CD34 immunohistochemistry. Statistical analysis was done to measure the mean number of ganglion cell nuclei and the wide clear areas around them. Groups II and III showed progressive histological changes of diabetic retinopathy. Group IV exhibited a significant increase in the number of ganglion cells with less clear areas compared with group III. Moreover, cells positive for Prussian blue and CD34 were detected in different retinal layers of group IV. Human cord blood-derived stem cells injected into rats with diabetic retinopathy contributed to restoration of ganglion cell layer and vascular repair, which may postulate a potential therapeutic intervention for diabetic retinopathy