title: Quantitative and sensitive in vitro assay for osteoinductive activity of demineralized bone matrix.
abstract: A sensitive, rapid, reliable and quantitative method to check the bone forming potential of demineralized bone matrix (DBM) has been developed. The osteoinductivity of the bone morphogenetic proteins (BMPs), present in DBM, can be measured in vitro using a pluripotent myoblast C2C12 cell line. Alkaline phosphatase activity induced by co-incubation of DBM with C2C12 cells was dose-responsive and corresponds to the amount of active BMPs in DBM. Bone forming potential was simultaneously tested in vivo by implanting DBM intra-muscularly in nude rats. ALP activity induced in C2C12 cells, correlated with bone formation in vivo (r=0.88), determined by alkaline phosphatase activity, mineralization density and histomorphology of the DBM explants. Results from DBM batches, originating from five established Bone Banks, showed good consistency between in vitro and in vivo assays. However, DBM activity varied widely from bank to bank as well as from batch to batch within the same bank.
authors.affiliation: Tissue Engineering Laboratory, Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Han
authors.forename: Baowei
authors.initials: B
authors.lastname: Tang
authors.forename: Marcel E
authors.initials: ME
authors.lastname: Nimni
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D018775:Bone Demineralization Technique; D015519:Bone Density; D001857:Bone Matrix; D018786:Bone Substitutes / Q000494:pharmacology*; D016025:Bone Transplantation; D001842:Bone and Bones / Q000502:physiology*; D002454:Cell Differentiation; D002460:Cell Line; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D032446:Myoblasts / Q000166:cytology; D010012:Osteogenesis / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011923:Rats, Nude; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D018786:Bone Substitutes; D000469:Alkaline Phosphatase