Induced pluripotent stem cells (iPSCs) as a new source of bone in reconstructive surgery: A systematic review and meta-analysis of preclinical studies

It is now well established that regenerative medicine and stem cell therapy are the most promising approach to obtain full tissue regeneration by using various cell types including stem cells isolated from adult tissues, embryonic stem cells, and induced pluripotent stem cells (iPSCs). Recently, iPSCs have been successfully differentiated into osteoprogenitors to facilitate repair and regeneration of bone defects. Thus, the purpose of this systematic review and meta-analysis is to summarize the articles published that assess the osteogenic potential of iPSCs in vitro and their ability to heal bone defects in reconstructive surgery. PICO questions were subjected to literature search in four different databases. Methodological and risk of bias assessment of the included in vitro and in vivo articles were performed. Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess the quality of evidence for each outcome variable included in the systematic review. In vivo bone formation was selected as the primary outcome for meta-analysis, and publication bias was explored using funnel plots. Initial literature search retrieved 4,772 studies, whereas only 70 articles included in the review. Yamanaka set was the commonly used reprogramming factor introduced with different vectors into the somatic cells. Several somatic cell sources have been used to successfully produce the iPSCs. iPSCs have osteogenic differentiation capacities and would be considered as a new source of stem cells that can be used in reconstructive surgery for bone regeneration.