**4. Clinical reports on stem application of bone tissue engineering**

A clinical study by Centeno and colleagues reported the application of culture-expanded, autologous BM-MSC for osteoarthritis in more than 300 patients. The authors reported the safety and efficacy of its use. Briefly, the autologous BM-MSCs were cultured in monolayer culture flasks and transplanted into the affected peripheral joints. They concluded that a 50% improvement in clinical symptoms was recorded among the osteoarthritis patients [27]. The application of infrapatellar fat pad-derived ASCs was demonstrated by Koh and colleagues when they reported its efficiency in improving and managing knee osteoarthritis through clinical and radiological results [28].

A mixture of stem cells and progenitor cells with CD90- and CD14-expressing cells resident in the bone marrow called tissue repair cells (TRC) has been demonstrated to be efficient for reconstructing craniofacial bone defects in a controlled feasibility trial [29]. Briefly, the clinical trial was carried out using 24 patients in need of localized osseous reconstruction. The patients were randomized to either guided bone regeneration (GBR) or TRC transplantation and were subsequently assessed. They concluded that TRC therapy resulted in an accelerated and improved alveolar bone regeneration compared to GBR therapy.
