OBJECTIVETo explore a new method for in vitro expansion of human mesenchymal stem cells (MSC) by using platelet-rich plasma (PRP) in place of fetal calf serum (FCS).

METHODSBone marrow(BM) samples were obtained from the proximal femurs of patients with normal haematopoietic function undergoing total hip arthroplasty. 2 x 10(5)/cm2 BM nucleated cells were seeded in 25 cm2 flasks for MSC cultivation containing one of the 3 mediums: complete Dexter medium with 12.5% FBS and 12.5% horse serum (medium1), alpha-MEM with 10% FCS (medium2) and alpha-MEM with 5% PRP(medium3). At the same time, 1 x 10(6) nucleated BM cells and same amount of nucleated cells from iliac aspirate were seeded in 25 cm2 tissue flasks, colony forming unit-fibroblast (CFU-F) assay.

RESULTSCulture-expanded cells from proximal femurs presented a typical fibroblast-like morphology. Cells were positive for SH2 (CD 105), SH3 (CD73), Thy-1 (CD90), while negative for CD34 and CD45. On induction, these cells could differentiate into osteoblasts. A significantly higher proliferative capacity of MSCs expanded in medium3 was observed in comparison to those in mediuml or 2 without alteration of the phenotype and the differentiation property. CFU-F assays indicated that bone marrow from the proximal femoral contained significantly more CFU-F than that from iliac aspirate.

CONCLUSIONPlatelet-rich plasma can be used in place of FCS to provide a safer and more effective culture condition to expand MSCs for clinical purpose. The proximal femur BM cells can be obtained in hip surgeries.