Experimental study of construction of tissue engineered bone ectopically by human bone marrow mesenchymal stem cells / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the possibility and mechanism of construction of tissue engineered bone with human bone marrow mesenchymal stem cells (hBMSCs) as seeding cells and partially demineralized bone matrix (pDBM) as scaffold.</p><p><b>METHODS</b>hBMSCs are cultured and mutiplified. The 4th grade hBMSCs are seeded on the pDBM, the growth and adhesion of hBMSCs on pDBM are observed under scanning electro microscope. The adhesion efficiency is assessed. The complexes are implanted in the nude mice subcutaneously, the pDBM without cells as control. The grafts are taken out on the 8th and 12th week.</p><p><b>RESULTS</b>There is new bone formation on the 8th and 12th week in complex group. There is a layer of osteoblast like cells adhered on the surface of most of the new bone, which suggest the possibility of intramembranous ossification. There is no bone formation in control group.</p><p><b>CONCLUSIONS</b>Tissue engineered bone can be constructed with hBMScs and pDBM in vivo, and the mechanism of which could be intramembranous ossification.</p>

The effects of cryopreservation on growth and osteogenesis of human bone marrow stromai cells cultured on demineralized bone matrix / 中华创伤骨科杂志

Objective To investigate the effects of cryopreservation on the growth and osteogenesis capa- bility of human bone marrow stromal cells(BMSCs)on demineralized bene matrix(DBM).Methods Bone marrow aspirates were obtained from the lilac crests of three donors.The BMSCs were isolated from the bone marrow by density gradient centrifugation.Cells of passage 3 were cryopreserved in liquid nitrogen for 24 hours,and then re- covered.The non-cryopreserved BMSCs were used as the control,The cryopreserved and control BMSCs were cul- tured in osteogenic media,collected and labeled with Dil to be seeded onto the DBM when cells were confluent.The percentage of BMSCs adhered to the DMB was detected.The cell morphology and matrices secreted by BMSCs on the DBM were observed by the inverted phase-contrasted microscope,fluorescence microscope and scanning electron microscope(SEM).The growth and viability of BMSCs on the DBM were determined using the modified MTT ashy. The osteogenesis ability of BMSCs on the DBM was determined by assessment of the alkaline phosphatase(ALP) activity and osteocalcin(OCN)content.Results The percentages of the cryopreserved and control cells adhered to DBM were(97.25?1.17)% and(97.00?1.09)% respectively.The cells adhered well to the DBM and grew rapidly.Large amounts of matrices on the DBM were observed by the light microscope and SEM.The cells embedded in the matrices could be observed by fluorescence microscope.There were no significant differences in the assay values of MTT,ALP and OCN between the cryopreserved and control BMSCs on the DBM.Conclusion Since cryopreservation does not affect the growth and osteogenesis capability of BMSCs on DBM,the cryopreserved BMSCs can be used as a cell source in bone tissue engineering.