Shed Blood-derived Cells from Total Hip Arthroplasty Have Osteoinductive Potential: A Pilot Study

Abstract

Cell therapy using autologous cells has been used in the treatment of various medical conditions. The mononuclear cell (MNC) fraction of bone marrow (BM) contains stem/progenitor cells that could contribute to osteogenesis and angiogenesis. We asked whether MNCs derived from intraoperative shed blood (SB), consisting of peripheral blood and BM, have osteoinductive and angiogenic potential. We harvested SB and BM from six patients undergoing THA. Isolated MNCs from SB and BM were analyzed by flow cytometry to evaluate the CD34(+) cell fraction and 1 × 10(6) cells were seeded on an interconnective porous calcium hydroxyapatite ceramic (IP-CHA) and transplanted in the backs of athymic rats. IP-CHAs without cells were transplanted as controls and all composites were harvested after 4 and 8 weeks. Osteoinductive potential was evaluated by histologic observation, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) using anti-osteocalcin (OC) antibodies qualitatively and quantitatively. To evaluate angiogenic potential, capillary density was measured by immunohistochemistry using Isolectin B4 4 weeks after implantation. We found that CD34(+) cells existed in SB-MNCs and there was a trend toward lower frequency compared with BM-MNCs. Histologic osteoinduction, OC expression, and capillary density were increased by transplantation of MNCs from SB. Similar results were achieved with MNCs from BM. MNCs from SB have equivalent osteoinductive and angiogenic potential compared with those from BM. SB could be an attractive source for isolation of MNCs, enhancing osteoinduction and neovascularization, to augment the reconstruction of skeletal defects.