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At least 19 recordsLinked to original sources
PubMed2001

[Preparation of decalcified bone matrix, bone cement and bone morphogenetic protein composite].

OBJECTIVE: To investigate the most excellent composite proportion and the most convenient composite method of decalcified bone matrix (DBM), bone cement (BC) and bovine bone morphogenetic protein (bBMP) composite. METHODS: The canine DBM and the bBMP were prepared beforehand. First mix the bBMP and DBM together with the proportion of 1:25 with adsorption and directly, then add BC with different weight proportion and finally the complex material was examined by biomechanics, scan electron microscope, determination of bone inductive activity and implanted into the canine femoral defect caused by microwave-induced hyperthermia. RESULTS: The bBMP had strong bone inductive activity and had no affect for this function when combined with DBM with different method. There were irregular gaps in the composite and most of them with diameter less than 100 microns and the porosity of the composite was less than 20% when the proportion of DBM was 40%. So it was unfavorable for the new bone to form and the new blood vessels to reconstruct. The DBM and BC could not be combined together when the proportion of DBM was 80%. While the biomechanical intensity of the composite decreased and the qualities of the new bone forming and new blood vessels reconstructing improved successively when the proportion of DBM was from 50% to 75%. CONCLUSION: It is the most convenient that bBMP is combined with DBM directly while its bone inductive activity could not be affected. The composite material not only has high biomechanical intensity, but also is favorable for new bone to form and new blood vessels to reconstruct when the proportion of DBM is 50% and 60%. So it is favorable for bone repair in the places where need to bear a load. However it is also favorable for bone repair in the places where do not need to bear a load when the proportion of DBM is 75%.

Animals↗
PubMed2001

Demineralized bone matrix, bone morphogenetic proteins, and animal models of spine fusion: an overview.

Preclinical investigations on the use of bone morphogenetic proteins (BMP) in the spine have yielded promising results. This has led to the preliminary introduction of these growth factors in controlled clinical trials. Initial data made available suggest that these differentiating factors will play a major role in the treatment of spinal disorders in the future. This article reviews key preclinical studies and their results that formed the basis for introduction into clinical trials. Non-primate and non-human primate models of spine fusion with BMP are reviewed objectively, and important issues regarding carrier, dose, and site of implantation are discussed. Finally, exciting new gene therapy research is discussed, with comments made on its applicability for the future.

Animals↗
PubMed2004

[Bone quality in the respect of bone matrix].

Bone is abundant in extracellular matrices, and therefore,"bone quality" appears to reflect the property of the bone matrix. The bone matrix is composed of minerals and organic materials. The volume of collagen fiber is approximately 90% of the whole organic materials of the bone matrix. Since collagen fibers could resist tension, the elasticity of the bone seems to come from the property of the collagen fibers. The mineralization of the bone matrix is achieved by the formation of hydroxyapatite crystals. The non-collagenous proteins and proteoglycans may regulate the growth of the mineralized crystal.

Bone Matrix↗
PubMed1994

[Biochemistry of bone matrix].

Bone matrix proteins can be divided into several groups according to their function; structural proteins, cell adhesive molecules, growth factors, proteinases and others. 1) Type I collagen is a major structural protein. 2) Osteopontin and bone sialoprotein (BSP) are RGD-containing cell adhesive proteins. Cadherins, OSF-2 and MGP also act as cell adhesive molecules in cell to cell or cell to matrix signal transition systems. 3) BMPs, TGF-b, IGFs, FGFs and PDGF are bone growth factors associated to bone matrix. 4) Collagenases and cathepsins are well known organic bone matrix degrading enzymes.

Animals↗
PubMed1994

Activity and solubility of bone morphogenetic protein derived from porcine bone matrix.

Bone morphogenetic protein (BMP) was extracted from porcine bone matrix and purified by liquid chromatography. The final purified fraction was shown to be homogeneous by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis (SDS-PAGE). The molecular weight of porcine bone matrix-derived BMP was estimated to be about 20 kDa by SDS-PAGE. The final purified BMP was highly soluble in vivo, so that it dispersed immediately after implantation and exerted no effect on bone induction. The other crude active fractions obtained in the process of purification induced new bone in three weeks when implanted into muscle pouches of Wistar rats. These findings suggested that pure BMP requires an appropriate carrier (delivery system) for clinical use; hence, experiments using atelopeptide type-I collagen as carrier were conducted.

Animals↗
PubMedDate not supplied

Histologic study of a bovine demineralized bone matrix on bone repair process in rabbits calvaria.

The aim of this study was to evaluate histologically the bovine demineralized bone matrix, Osseobond, on bone repair process in rabbit's calvaria. Nine rabbits were used and two surgical defects were created on each calvaria, one was just filled with the animal blood and the other was filled with demineralized bone matrix. The animals were sacrificed in postoperative period of 3, 7, and 15 weeks. Specimens on light microscopy analysis revealed that bone repair were improved on cavities filled with bovine demineralized bone matrix.

Animals↗
PubMed1995

Purification and characterization of bone morphogenetic protein derived from bovine bone matrix.

Bone morphogenetic protein (BMP) was extracted from bovine bone matrix and purified. The 6M guanidine-HCL soluble fraction and the final purified substance were bioassayed by implantation of about 3 mg into the thigh muscles of C3H strain mice. These specimens induced new bone in three weeks when implanted into muscle pouches of the C3H mouse. The final fraction purified by liquid chromatography (fraction III) was shown to be homogeneous by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis (SDS-PAGE). The molecular weight of the bovine bone matrix-derived BMP was estimated to be about 14-18 kDa in MW. The main components correspond to a MW of 18 kDa and 14 kDa when they are compared with the mobilities of standard proteins. These were invariably present in fractions with osteoinductive activity.

Animals↗
PubMed1989

Purification of bone morphogenetic protein derived from bovine bone matrix.

Bone morphogenetic protein (BMP) was extracted from the bovine bone matrix and purified by liquid chromatography. The molecular weight of the BMP was 18 kDa by SDS-PAGE, and its pI value was 4.9. Amino acid analysis suggested that the BMP is a polypeptide containing 163 amino acids. In the present study, telopeptide-free type I collagen was used as a carrier of BMP.

Amino Acids↗
PubMed2004

Release of intact and fragmented osteocalcin molecules from bone matrix during bone resorption in vitro.

Osteocalcin detected from serum samples is considered a specific marker of osteoblast activity and bone formation rate. However, osteocalcin embedded in bone matrix must also be released during bone resorption. To understand the contribution of each type of bone cell in circulating osteocalcin levels, we used immunoassays detecting different molecular forms of osteocalcin to monitor bone resorption in vitro. Osteoclasts were obtained from rat long bones and cultured on bovine bone slices using osteocalcin-depleted fetal bovine serum. In addition, human osteoclasts differentiated from peripheral blood mononuclear cells were used. Both rat and human osteoclasts released osteocalcin from bovine bone into medium. The amount of osteocalcin increased in the presence of parathyroid hormone, a stimulator of resorption, and decreased in the presence of bafilomycin A1, an inhibitor of resorption. The amount of osteocalcin in the medium correlated with a well characterized marker of bone resorption, the C-terminal telopeptide of type I collagen (r > 0.9, p < 0.0001). The heterogeneity of released osteocalcin was determined using reverse phase high performance liquid chromatography, and several molecular forms of osteocalcin, including intact molecule, were identified in the culture medium. In conclusion, osteocalcin is released from the bone matrix during bone resorption as intact molecules and fragments. In addition to the conventional use as a marker of bone formation, osteocalcin can be used as a marker of bone resorption in vitro. Furthermore, bone matrix-derived osteocalcin may contribute to circulating osteocalcin levels, suggesting that serum osteocalcin should be considered as a marker of bone turnover rather than bone formation.

Animals↗
PubMed1991

Monkey bone matrix induces bone formation in the athymic rat, but not in adult monkeys.

Demineralized bone matrix from young and adult monkeys was implanted intramuscularly for 6 weeks in athymic rats and adult monkeys. Cartilage and bone induction was evaluated by histology and calcium content. In the athymic rat, most implants induced cartilage or bone. In the monkeys, cartilage was formed only on rare occasions and there was no sign of bone formation. We conclude that (a) adult monkey bone matrix contains bone inductive properties; (b) these properties are not sufficient to induce bone formation in adult monkey muscle sites.

Animals↗
PubMed1993

Localization of bone sialoprotein (BSP) to Golgi and post-Golgi secretory structures in osteoblasts and to discrete sites in early bone matrix.

Bone sialoprotein (BSP), a bone matrix-enriched glycoprotein containing the Arg-Gly-Asp (RGD) motif and endowed with cell binding properties, was localized in osteoblasts and early bone matrix of developing rat bone at the ultrastructural level. Preliminary light microscopic observations indicated that intracellular labelling was restricted to a paranuclear dot corresponding to the "negative Golgi image" of classical histology. The same pattern was observed whether antisera against the fully glycosylated protein or a peptide antiserum to a stretch of amino acids in human BSP sequence were employed. At the EM level, we obtained labeling over the Golgi area of osteoblasts but not over the rER. The labeling was concentrated over distensions of the trans Golgi and over pro-secretory granules. In the matrix, BSP was distributed in a non-random manner. The label was concentrated over spherical aggregates of finely fibrillar material corresponding to the sites of early mineral deposition (so-called "mineralization nodules"). Such BSP-positive foci were seen both close to and away from the cell surface. The predominant association of BSP with Golgi and post-Golgi secretory structures and its absence from rER, as well as the reproducibility of the same pattern of localization with different antisera, might indicate a slow transit of the protein through the Golgi, not necessarily associated with protein glycosylation.

Amino Acid Sequence↗
PubMed1997

Utilization of type I collagen gel, demineralized bone matrix, and bone morphogenetic protein-2 to enhance autologous bone lumbar spinal fusion.

Autologous bone grafts are currently considered "gold standard" material for achieving long-term spinal arthrodesis. The present study was performed to determine whether demineralized bone matrix (DBM), type I collagen gels, or bone morphogenetic protein-2 (BMP-2) can improve autologous bone spinal fusions. Using a unilateral decompression-contralateral fusion technique in dogs, each of these materials was added to an autologous bone graft. Volumetric analysis, histological analysis, and biomechanical testing were performed to assess the effectiveness of each material. The DBM had an inhibitory effect on solid bone fusion of the spine, whereas the type I collagen gels improved the bony interface between the graft and the host spine. The BMP-2 strongly enhanced the amount of bone deposition at the fusion site and increased the number of intervertebral levels that were solidly fused. This study strongly supports the use of BMP-2 as an additive to autologous bone grafts in spine stabilization.

Animals↗
PubMed1990

Interactions of growth factors present in bone matrix with bone cells: effects on DNA synthesis and alkaline phosphatase.

It has been shown that bone cells produce and secrete several growth factors (GFs) which are also found in the bone matrix. To investigate the role of these growth factors in bone cell metabolism, we compared the effects of different factors separately and in combination with respect to osteoblastic cell proliferation and differentiation. While basic fibroblast GF (FGF), transforming GF beta-1 (TGF beta), and platelet-derived GF (PDGF) enhance DNA synthesis, they had the opposite effect on alkaline phosphatase (ALP) activity in cell extracts: FGF, TGF beta, and PDGF inhibited cell ALP but strongly stimulated DNA synthesis. The IGFs had little effect on cell ALP but increased the release of ALP into the conditioned medium. In mitogenic tests of combinations of GFs, most had at least additive effects at low concentrations, and FGF, TGF beta, and IGF2 produced synergistic effects. Evidence is presented for (1) the modulation of the effects of one GF by the action of other GF, (2) synergistic interactions between FGF, TGF beta, and IGF2, and (3) a possible role for the observed interactions among GF for the mitogenic effect of human bone extract.

Alkaline Phosphatase↗
PubMed1994

[Growth factors and bone tissue. Implications in the formation of bone matrix].

Bone formation is highly dependent on the number of osteoblastic cells. Simulating factors which recruit osteoblastic cells play an essential role in regulating bone formation. Several growth factors produced locally by bone marrow cells and osteoblasts regulate cell growth and differentiation of osteoblastic cells. These growth factors may be systemic or local and can be stocked in the matrix. The factors secreted locally play a dominant role in regulation and are stocked in an active form in the bone matrix. Growth factors act through both autocrine and paracrine effects, or as local mediators of hormones and compression forces. The wide range of effects of the local growth factors and cytokines on bone cells, and the numerous interactions between these factors lead to precise regulation of the osteoblastic function. Thus these factors plan an extremely important role in local regulation and cell growth and osteoblastic differentiation, and are highly implicated in local control of bone formation.

Bone Matrix↗
PubMed1992

Influence of short-term aluminum exposure on demineralized bone matrix induced bone formation.

The effects of aluminum exposure on bone formation employing the demineralized bone matrix (DBM) induced bone development model were studied using 4-week-old Sprague-Dawley rats injected with a saline (control) or an aluminum chloride (experimental) solution. After 2 weeks of aluminum treatment, 20-mg portions of rat DBM were implanted subcutaneously on each side in the thoracic region of the control and experimental rats. Animals were killed 7, 12, or 21 days after implantation of the DBM and the developing plaques removed. No morphological, histochemical, or biochemical differences were apparent between plaques from day 7 control and experimental rats. Plaques from day 12 control and experimental rats exhibited cartilage formation and alkaline phosphatase activity localized in osteochondrogenic cells, chondrocytes, osteoblasts, and extracellular matrix. Unlike the plaques from control rats that contained many osteoblastic mineralizing fronts, the plaques from the 12-day experimental group had a preponderance of cartilaginous tissue, no evidence of mineralization, increased levels of alkaline phosphatase activity, and a reduced calcium content. Plaques developing for 21 days in control animals demonstrated extensive new bone formation and bone marrow development, while those in the experimental rats demonstrated unmineralized osteoid-like matrix with poorly developed bone marrow. Alkaline phosphatase activity of the plaques continued to remain high on day 21 for the control and experimental groups. Calcium levels were significantly reduced in the experimental group. These biochemical changes correlated with histochemical reductions in bone calcification.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed2003

Reconstruction of cartilage, bone, and hematopoietic microenvironment with demineralized bone matrix and bone marrow cells.

Highly specialized hard tissues, such as cartilage, bone, and stromal microenvironment supporting hematopoiesis, originate from a common type of mesenchymal progenitor cell (MPC). We hypothesized that MPCs present in bone marrow cell suspension and demineralized bone matrix (DBM) that possess natural conductive and inductive features might constitute a unit containing all the essential elements for purposive bone and cartilage induction. Using a rodent preclinical model, we found that implantation of a composite comprising DBM and MPCs into A) a damaged area of a joint; B) an ablated bone marrow cavity, and C) a calvarial defect resulted in the generation of A) a new osteochondral complex comprising articular cartilage and subchondral bone; B) trabecular bone and stromal microenvironment supporting hematopoiesis, and C) flat bone, respectively. The new tissue formation followed differentiation pathways controlled by site-specific physiological conditions, thus developing tissues that precisely met local demands.

Animals↗
PubMed1988

Rabbit bone matrix induces bone formation in the athymic rat.

Rabbit and rat bone matrix were implanted in athymic rat muscle, and the bone yield was measured as total calcium content after 4, 6, and 8 weeks. Matrix from both species induced equal amounts of new bone in the athymic rat. In rabbit and normal rat, the xenogenic matrix induced little or no bone formation. Thus, in the case of rabbit and rat, bone induction is species specific due to immunogenic mechanisms. The athymic rat can be used to measure inductive properties of bone matrix from different species.

Animals↗
PubMed2003

Combined effects of phosphatidylcholine and demineralized bone matrix on bone induction.

The osteoinductivity of demineralized bone matrix (DBM) becomes significantly reduced if the specimens are further delipidated with chloroform-methanol. The addition of phosphatidylcholine (PC), a major constituent of the lipid fraction present in the calcification front during normal bone formation, can restore the biological activity. Active endochondral bone formation is observed in the DBM/PC implants placed in the anterior abdominal wall musculature or subcutaneously for 28 days. When PC is added to generate a putty containing 60% PC and 40% DBM, biochemical parameters associated with osteoinductivity are significantly enhanced. Biological responses evaluated histologically and by determination of alkaline phosphatase activity are in very good agreement. The DBM/PC putty has good handling properties, can be molded into different shapes, and does not wash away from the application site. An advantage of adding PC is that it not only enhances the handling properties, but also boosts the osteoinductivity of the preparation.

Alkaline Phosphatase↗