Introduction Endothelial progenitor cells (EPCs) are cells that can differentiate into endothelial cells in vitro. Their importance lies on the fact that vasculature has a cornerstone role in the healing process after injury of the musculoskeletal system and of the spine. The main target of this review is to clarify whether EPCs could be a viable alternative of mesenchymal stem cells for musculoskeletal regeneration.
Methods The literature search was performed via the internet using the Medline, Scopus and Cochrane database. The key words which were searched in the abstracts were the terms ‘EPCs’, ‘bone’, ‘spine cord’, ‘cartilage’, ‘menisci’, ‘ligament’, ‘tendon’ and ‘healing’.
Results Three papers reported that EPCs can differentiate into osteoblasts in vitro. In a fourth paper, EPCs were used in an in vivo model in order to enhance the fracture healing in a non-union animal model. A fifth paper implies that fracture may induce mobilisation of EPCs and recruitment of the mobilised EPCs into fracture sites. Another two papers showed that local transplantation of EPCs with atelocollagen scaffold is a feasible strategy for therapeutic vasculogenesis and osteogenesis needed for fracture and ligament healing. Another paper suggested that co-transplantation of hematopoietic and mesenchymal stem/progenitor cells may improve the regeneration of vascular dependent tissues such as bone, adipose, muscle and dermal grafts. Two papers reported stimulating results for the use of EPCs for spine cord regeneration.
Discussion The importance of EPCs for the healing of both musculoskeletal tissue and spine is based on the advantages of this cell population for regeneration purposes: (1) relative abundance, (2) isolation by the circulation, (3) new insight revealing new mechanisms