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

ABSTRACT

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.