Biobridge concept in stem cell therapy for ischemic stroke.

Stroke causes a significant social and economic burden to the society. Despite advancement in awareness and prevention of stroke, there are still limited treatment options for stroke patients. One of the emerging experimental therapies for stroke is stem cell transplantation. The conventional belief of stem cell mechanisms is that the protective effects are produced by either cell replacement or releasing trophic factors. While the exact mechanisms of action of stem cells are not completely understood, recent evidence demonstrates another possible mechanism of stem cells. This new approach emphasizes on the formation of a biobridge between the damage area and the endogenous neurogenic niches of the brain. The transplanted cells can form a pathway which promotes the proliferation and migration of the endogenous stem cells. This paper discusses the use of stem cell transplantation for stroke with an emphasis on the new biobridge concept. Also discussed are the current challenges faced before this approach can advance to the clinical setting.