Do stem cells promote healing of experimentally induced wound injury in adult male dogs? Histological and immunohistochemical study

Background: Stem cells have generated considerable interest and promise as a potential source of cells for cell-based therapeutic strategies, primarily owing to their intrinsic ability to self-renew and differentiate into multiple functional cell types. Stem cells have been utilized to regenerate viable skin tissue

Aim of the work: The present study was carried out to investigate the healing capacity of autologous bone marrow-derived mesenchymal stem cells [BM-MSCs] and its regenerative role in experimentally induced wound injury

Materials and methods: The present study was carried out on 18 dogs. The study included two groups. Group I [n=6] was used a negative control and received no treatment. Group II was used as an experimental group and was divided into subgroup IIa [n=6], used as a positive control, and subgroup IIb [n=6]. Subsequently, three circular wounds were made using a 10-mm diameter skin punch biopsy in the animals of subgroup IIa and subgroup IIb to induce wound injury. Group IIb were injected subcutaneously with undifferentiated mesenchymal stem cells at a dose of 1.4-1.6×10[6]/ml in 5 ml sterile saline into the wound bed for 2 weeks after wound injury; skin biopsies from the wound areas were prepared for staining by H and E and immunostaining using anti-Thy-1 [CD90] antibodies

Results: BM-MSC-treated wounds showed accelerated wound closure, with increased re-epithelialization of the epidermis, increased dermal cellularity and hair follicles, and angiogenesis. This was confirmed by the apparent increased immunoreactivity of the cell content of anti-rat Thy-1 CD90 cells in the dermis

Conclusion: Asubcutaneous injection of autologous undifferentiated mesenchymal stem cells into the wound bed is an effective method of wound regeneration and can be used in chronic wounds as in a diabetic foot

Role of stem cells in regeneration of myocardium in experimentally induced myocardial infarction

Stem cells have generated a great deal of excitement and promise as a potential source for cell based therapeutic strategies. Primarily owing to their intrinsic ability to self re-new and differentiation into multiple functional cell types. Emberyonic stem cells [EBCs] and bone marrow-derived cells [BMCs] have been studied and dramatic advances have been achieved in their clinical application in ischemic and non- ischemic heart failure. The present study was done to investigate the healing capacity of autologous bone marrow-derived mesenchymal stem cells [BM-Mscs] and its regenerative rote in experimentally induced myocardial infarction. The study included two groups of albino rabbits. Group I [n=10] was used a negative control and received no treatment. Group II was used as an experimental group and was divided into subgroup IIa [n=10] used as positive control and subgroup IIb [n=10]. Animals of subgroup IIa and subgroup IIb received a single subcutaneous [s.c.] injection of isoproterenol [150mg/kg] to induce myocardial infarction. Group lIb were received undifferentiated mesenchymal stem cells in a dose of [1.4- 1.6 X 10[6] ml. in 5 ml sterile saline] intravenously [iv.] 2 weeks after injury. The animals were anaesthetized by ether and killed 2 weeks after transplantation. The regeneration capacity of the engrafied cells was detected by H and E and immunostaining using antivimentin antibodies. Damaged myocardium revealed regeneration denoted by increased content of vimentin proteins in the cytoplasm of the regenerated cardiac myocytes and in the wall of the newly formed small blood vessels. Transplantation of autologous undifferentiated mesenchymal stem cells injected i.v. in rabbits is an effective method of myocardial regeneration in cases of myocardial infarction