Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bone Matrix”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
PubMed1998

Alveolar bone formation at dental implant dehiscence defects following guided bone regeneration and xenogeneic freeze-dried demineralized bone matrix.

The present study evaluated rate and extent of alveolar bone formation in dental implant dehiscence defects following guided bone regeneration (GBR) and implantation of xenogeneic freeze-dried demineralized bone matrix (xDBM). A total of 16 titanium plasma-sprayed (TPS) and 16 hydroxyapatite-coated (HA) titanium cylinder implants were inserted in 4 mongrel dogs following extraction of the mandibular premolar teeth. Four implant sites per jaw quadrant (2 TPS and 2 HA implant sites) were prepared into extraction sockets in each dog. Buccal alveolar bone was removed to create 3 x 5 mm dehiscence defects. Two jaw quadrants in separate animals received GBR, GBR + xDBM, xDBM (control), or gingival flap surgery alone (GFS; control). Thus, four conditions were available for each implant type (TPS or HA): GBR, GBR + xDBM; xDBM and GFS. The animals received fluorescent bone labels to allow observations of rate and extent of bone formation. Animals were sacrificed at 12 weeks postsurgery and block sections were harvested for histologic analysis. There were no apparent histologic differences between TPS and HA implant defects. GBR and GBR + xDBM resulted in almost complete bone closure of the dental implant dehiscence defect. Rate of bone formation appeared higher following GBR alone. Extent of bone formation appeared somewhat greater following GBR + xDBM; however, delayed. xDBM alone did not adequately resolve the bony defect. In conclusion, GBR results in rapid, clinically relevant bone closure of dental implant dehiscence defects. Adjunctive implantation of xDBM does not appear to significantly improve the healing response in the model used.

Alveolar Process↗
PubMed1995

Sterilization of partially demineralized bone matrix: the effects of different sterilization techniques on osteogenetic properties.

Transplantation of allogenic bone requires the thorough examination of donors as well as the careful processing and storage of samples in order to minimize potential infection. Other problems associated with allogenic transplants such as low osteoinductive properties and immunological reactions led to the development of partially demineralized bone matrix (PDBM). This highly osteogenic bone extract is largely free of antigens and easy to produce. However, in order to exclude the potential risk of infection, PDBM should be sterilized prior to implantation. It was the purpose of this study to investigate the influence of various sterilization techniques on the osteoinductive properties of PDBM. Seventy-six drill defects with a diameter of 0.6 cm in the tibia of 11 Merino sheep were filled with PDBM as well as autogenic or allogenic cancellous bone. Prior to implantation the PDBM was sterilized using autoclavation, gamma irradiation, ethylene oxide, or ethanol. Twelve empty drill holes served as controls. The extent of new bone formation was ascertained by histological, fluorescent-optical, and microradiographical examinations 3 and 6 weeks postoperatively. Furthermore, the amount of newly formed bone was measured quantitatively. Apart from autoclaved PDBM, all matrix grafts showed excellent new bone formation after sterilization, exceeding the results of allogenic cancellous bone.

Animals↗
PubMed1997

[The effects of microwave heating on osteoinduction of demineralized bone matrix in rabbits].

In order to study the change of the autograft demineralized bone matrix, twenty-four new-Zealand rabbits were randomly divided into four groups of 2, 4, 8, 12 week by sacrified time, each group had 7, 7, 5, 5 rabbits. Autoradiography was done for 2 rabbits in 2, 4 weeks respectively. The tibiae were removed by amputation at knee joint level, then they were cleansed of marrow and periosteun, cut into six pieces in length of 0.8 cm heated with microwave. Demineralized bone matrix were made by defated and decalcified, and implanted into abdomenal walls autograft. The results showed that the implants heated at 45 degrees C 30 min had same osteoinduction as control group. The 65 degrees C 30 minutes heating may reduce implant's osteoinduction slightly. The osteoinduction of the groups heated 75 degrees C for 30-60 minutes were impaired severely. The implants boiled at 100 degrees C 30 minuts had no osteoinduction at all, 65 degrees C 30 minutes may be a "safty" limit when heat treatment on bone clinically. Otherwise, bone formation ability would be reduced and remodelling was delayed.

Abdominal Muscles↗
PubMed1984

Glycosaminoglycan synthesis by rat fibroblast monolayers: effects of serum and solubilized bone matrix fractions.

Glycosaminoglycan synthesis by fibroblasts, from skeletal muscle of the neonatal rat, is stimulated by a bone matrix preparation, soluble in isotonic medium, obtained by extracting decalcified rat bone with 4 M guanidine HCl. The stimulation in glycosaminoglycan synthesis is dependent on the presence of serum in the culture, but the stimulatory effect can be clearly distinguished from that of serum. The stimulatory activity in the bone matrix has been fractionated by ion-exchange chromatography and coelutes largely with anionic, non-collagenous matrix glycoproteins.

Animals↗
PubMed1992

New bone induction by demineralized bone matrix in immunosuppressed rats.

Subcutaneous implantation of demineralized bone matrix (DBM) initiates a sequence of developmental events which culminate in endochondral bone formation. To test the effects of T-cell deficiency on new bone formation, the morphology of DBM-induced bone was examined in rats thymectomized at three weeks of age and in thymectomized or nonthymectomized rats lethally irradiated and reconstituted with syngeneic bone marrow. At 24 days after implantation, bone induction in control rats was appropriate for their age, while thymectomized-irradiated-reconstituted rats and thymectomized rats had significantly more new bone and larger bone marrow space than the controls. In non-thymectomized, irradiated and reconstituted rats, bone induction occurred in only 25% of the animals, compared to 95% in other groups.

Age Factors↗
PubMed1977

A bone matrix calcification-initiator noncollagenous protein.

When completely demineralized, the densely packed structure of bone matrix does not recalcify, neither in physiologic solutions in vitro nor in implants in vivo. Even when inorganic and organic calcification inhibitors (which normally are stored in bone matrix) are removed first by autolytic digestion in neutral buffers at 37C and then by sequential chemical extraction, implants of the EDTA insoluble residue will not recalcify after as long as 4 wk in a muscle pouch. However, if first demineralized in cold dilute HCl, second, extracted and autodigested in buffers solution at 37C, and then further extracted in EDTA and other solutions at 2C, a calcification initiator protein (Cp) is unmasked, and the residue will invariable recalcify. CIP, isolated by gel filtration and column chromatography, is a disulfide-bonded glycoprotein aggregate composed of subunites of a moleclar mass of 55,000. CIP is composed of a large proportion of acidic amino acids and has a calcium binding capacity of about 1.8 times greater than albumin. The affinity constant CaCIP, calculated by ultrafiltration of physiologic solutions of Ca2+, is log K, 2.9. Observations on implants of residues that containe a) CIP but not a bone morphogenetic property (BMP), B) BMP accompanied by CIP activity, or c) neither BMP nor CIP activity suggested that BMP covers CIP and that the two are attached to bone collagen in tandem. Whether CIP plays a part in calcification of the normal skeleton requires further investigation.

Amino Acids↗
PubMed1998

The effect of altered functional forces on the expression of bone-matrix proteins in developing mouse mandibular condyle.

Mechanical forces are known to have an effect on bone formation, maintenance and remodelling, and there is evidence that the development of the mandibular condyle in the rat is influenced by the consistency of the diet. Here a mouse model was used to investigate the relation between food, condylar development and the expression of bone sialoprotein (BSP), osteopontin (OPN), osteocalcin (OC) and type 1 collagen (COL I). Twenty-four 19-day-old male mice were randomly divided into three groups. Groups 1 and 2 were fed hard pellets and soft powdered food, respectively, for 2 weeks. Group 3 mice were fed soft food for 1 week followed by a week of hard pellets. Incisors of mice in groups 2 and 3 were trimmed twice a week to reduce occlusal forces. After killing the animals, mandibular condyles were collected for RNA extraction, in situ hybridization and immunohistochemical analyses. Histological sections showed that the condyles of mice in group 2 were underdeveloped, with a thinner layer of cartilage and fewer bone trabeculae. Northern hybridization of total RNA of the condyle from mice in this soft-food group also exhibited a significant decrease in the amounts of BSP, OPN, OC and COL I, representing 79%, 75%, 77% and 79% respectively, of that from mice fed hard food. In situ hybridization of these bone-matrix proteins demonstrated signals in bone-forming cells and BSP mRNA was also seen in the hypertrophic cartilage cells in the developing condyle. Immunohistochemical study demonstrated an obvious difference in the intensity of staining, especially for BSP. Results from group 3 were similar to those from group 1. The observed decrease in bone matrix-protein expression confirms that the consistency of the diet affects the development of the mouse mandibular condyle and that a soft diet diminishes the rate of bone formation.

Animals↗
PubMed1991

Muscle tissue reactions to implantation of bone matrix gelatin.

Histologic changes of muscle tissue in the early stage of heterotopic osteogenesis induced by syngeneic insoluble bone matrix gelatin (BMG) with bone morphogenetic protein in rats was observed by light and electron microscopy. BMG induced cartilage in muscle tissue by Day 7 after its implantation, woven bone by Day 10, and lamellar bone with bone marrow by Day 14. The new findings in this work include (1) the disappearance of the basement membrane of muscle fibers; (2) the activation of the satellite cells of muscle fibers; (3) the appearance of fibroblastlike cells that closely resembled activated satellite cells among the degenerated muscle fibers or on the surface of the BMG; and (4) the change of fibroblastlike cells to chondroblasts or osteoblasts. These findings suggest that intramuscular implantation of BMG caused the conspicuous disappearance of the basement membrane of the muscle fiber and may play a part in osteogenesis induced by BMG.

Animals↗
PubMed2006

Mammary gland secretory concretions contain non-collagenous bone matrix proteins.

Secretory concretions in mammary gland alveoli are commonly of microscopical size. However, some concretions reach clinically palpable dimensions and may occlude teat canals and obstruct milk flow. We studied secretory concretions in sheep, goat and cow mammary glands, using routine histological staining methods, conventional histochemistry and electron microscopy. As concretions frequently mineralize, immunostaining for keratan sulphate and calcium-binding non-collagenous bone matrix proteins (bone sialoprotein, osteocalcin, osteonectin and osteopontin) was performed. Concretions consisted of organic matrix (condensed secretions) with calcium precipitates. Mineralized deposits mostly show concentric organization, bound haematoxylin, and were readily identified in H&E-stained sections. Mineral components of concretions reacted for calcium carbonate and phosphate, organic matrix was found to contain sialoglycan material. Immunohistochemistry revealed bone sialoprotein, osteonectin and keratan sulphate in cow and goat concretions. Osteocalcin was detected in sheep, cow and goat concretions, whilst osteopontin was not identified in any of the specimens studied. Our results indicate the presence of non-collagenous bone matrix proteins (except osteopontin) in mammary gland concretions. These glycoproteins are commonly thought to govern mineralization of organic matrix and are assumed also to promote mineral deposition in mammary gland secretory concretions. Besides caseins, these particular glycoproteins have to be considered as calcium-binding milk proteins.

Animals↗
PubMedDate not supplied

Perforated demineralized bone matrix: a new form of osteoinductive biomaterial.

This study was undertaken to evaluate a new osteoinductive material--perforated decalcified bone matrix (PDBM). Subcutaneous implantation of PDBM induces multiple centers of endochondral osteogenesis with subsequent resorption of bone matrix and its replacement by new bone. PDBM should therefore prove useful as a research model to study osteoinduction and in the clinical situation in orthopedic and reconstructive surgery for the filling of bone defects and stimulation of fracture healing.

Animals↗
PubMed1999

Trabecular bone turnover, bone marrow cell development, and gene expression of bone matrix proteins after low calcium feeding in rats.

Low-calcium-fed animals have been accepted as one of the experimental models showing a reduction in bone mass. However, the effects of short-term low-calcium feeding on bone turnover, the development of osteoprogenitor cells, and gene expression of bone matrix proteins have not been reported. In this study, we examined the effect of a low-calcium diet on rat tibia and analyzed the changes in the bone by histomorphometry, bone marrow cell culture, and in situ and Northern hybridization of the bone matrix proteins. Rats were fed either a low-calcium diet (0.05% Ca) or a normal calcium diet (0.5% Ca) using the pair feeding technique. They were killed at day 0, 12 h, and days 1, 2, and 3. In the low-calcium group, the serum parathyroid hormone (PTH) level was temporarily increased in 12 h after feeding the low-calcium diet. Bone mineral density in the trabecular bone was significantly decreased from 1 day after the low-calcium feeding, but cortical bone did not show any changes during the experimental period. The bone volume per tissue volume in the proximal tibia also decreased from day 1 in the low-calcium group. The number of osteoclasts and osteoblasts on the trabecular bone surface was increased in the low-calcium group compared with the normal-calcium group. An ex vivo study showed that the number of progenitors of osteoclasts and osteoblasts in bone marrow was also increased in the low-calcium group of rats. The localization of type I collagen mRNA was observed in osteoblasts in the low-calcium group. The Northern hybridization study showed that the gene expression of type I collagen, osteopontin, and osteocalcin was increased at day 3 in the low-calcium group. These results indicated that the trabecular bone surface quickly responded to the low-calcium feeding and that bone remodeling activity was activated probably by PTH. The changes in bone marrow cell populations and the gene expression of bone matrix proteins are closely associated with increased bone turnover induced by the low-calcium diet, resulting in rapid bone loss of the trabecular bone.

Animals↗
PubMed2005

Demineralized bone matrix gelatin as scaffold for osteochondral tissue engineering.

To develop a single-unit osteochondral tissue with demineralized bone matrix gelatin (BMG), rabbit chondrocytes were cultured on demineralized bone matrix gelatin for 6 weeks. The engineered osteochondral tissue was characterized with histology, immunolocalization, TEM, SEM, biochemical assay, and gene expression analysis. About 1.3mm viable neo-cartilage was produced on demineralized BMG. RT-PCR, immunohistochemistry, TEM, biochemical assay, and histology revealed hyaline-like cartilage with zonal layers, intense type II collagen expression, and abundant proteoglycan content formed upon BMG compared with normal cartilage. But hydroxyproline content and type I collagen gene and protein expressions were significantly lower. We consider engineering cartilage tissue with chondrocytes cultured on allogenic demineralized BMG is a good approach for osteochondral tissue engineering.

Animals↗
PubMed1985

Implant-stimulated interface reactions during collagenous bone matrix-induced bone formation.

The sequential cellular reactions in the interface of collagenous bone matrix implants are described. The multistep cascade in response to bone matrix implantation include: binding of fibrin and fibronectin to the implanted matrix, chemotaxis of cells, proliferation of fibroblasts, differentiation into chondroblasts, cartilage formation, vascular invasions, bone formation, remodeling, and bone marrow differentiation. The mechanisms of action is not known. However, several properties governing the implant-cell interface are described. It is possible that bone matrix is a suitable biomaterial with potential applications in periodontal and orthopedic practice.

Animals↗
PubMed1999

[The experimental study of repairing bone defects with allogeneic bone matrix gelatin and plaster].

OBJECTIVE: To study the function of the composite of bone matrix gelatin(BMG) and plaster in the repairing process of bone defects. METHODS: Sixteen New Zealand rabbits which were defected in corpus radii were made as implant zone of bone. Sixteen sides of radii were implanted with the composite of BMG and plaster as experimental group. Others were implanted with BMG(8 sides) and bone stored in alcohol(8 sides) as control groups. The repairing process in bone defects were observed by X-ray and histological examination. RESULTS: There was an obvious osteogenesis in experimental group. The defects of radii were almost healed at 12th week after operation. There were osteogenesis in both control groups, but the repairing process was slower than that of the experimental group. CONCLUSION: The composite of BMG and plaster is a good material for bone transplantation.

Animals↗
PubMed1996

Effects of osteogenic protein-1 (OP-1, BMP-7) on bone matrix protein expression by fetal rat calvarial cells are differentiation stage specific.

Bone morphogenetic proteins (BMPs) are a group of cytokines that are characterized by their ability to stimulate osteoblast differentiation and bone formation. However, the influence of BMPs on osteoblastic cells at different stages of differentiation is not known. Since bone matrix proteins are differentially regulated during bone formation we have studied the effects of recombinant human osteogenic protein-1 (rhOP-1; BMP-7) on the expression of these proteins by fetal rat calvarial cells (FRCCs) at discrete stages of osteoblast differentiation. Continuous administration of rhOP-1 to FRCCs, beginning at confluence (day 7), produced a dose-dependent increase in the number, size and mineralization of bone-like nodules formed in the presence of vitamin C and beta-glycerophosphate. Within 9 h of administration, rhOP-1 stimulated a 3-fold increase in OPN mRNA which was reflected in a comparable increase in the low phosphorylated, 55 kDa form of osteopontin. In contrast, changes in type 1 collagen, alkaline phosphatase and bone sialoprotein mRNAs followed the differentiation of preosteoblastic cells, and were increased 2-, 4- and 5-fold, respectively, after 8 days (day 15). When administered at intermediate stages of osteoblast differentiation (days 12, 15 and 18) BSP remained refractory to rhOP-1 whereas the ALP was increased almost 2-fold, independent of the constitutive levels of mRNA expression. To determine the effects on osteoblasts, FRCCs were first grown to the bone nodule-forming stage (day 21) before rhOP-1 was administered. Only modest, transient increases in the expression of ALP and OPN mRNAs were evident whereas OC expression was increased more than 3-fold. In contrast, collagen type 1 and BSP mRNA levels were not changed significantly. These results suggest that rhOP-1 increases bone formation by promoting osteoblastic differentiation, as indicated by the increased number of bone forming colonies and by increasing the number of osteoblastic cells in the colonies, but not by increasing matrix production by individual osteoblasts. It is also evident that the regulation of bone matrix proteins by rhOP-1 is dependent upon the differentiated state of the cell.

Animals↗
PubMed1998

Effects of estrogen on the concentration of insulin-like growth factor-I in rat bone matrix.

Insulin-like growth factor-I (IGF-I) plays an important role in bone metabolism, but data on the regulation of IGF-I in bone tissue in vivo are still limited. In the present study, we examined the effects of ovariectomy (ovx) and estrogen replacement on the skeletal concentration of IGF-I in the femur shaft of 6-10 week-old female rats. Ovx had no consistent effect on bone matrix IGF-I concentration regardless of animal age at ovx. In contrast, administration of estradiol in doses that exceeded physiological replacement (50 and 150 nmol/kg per day, subcutaneously) significantly increased the bone matrix IGF-I concentration. These are the first in vivo data which demonstrate that estrogens are capable of increasing the concentration of IGF-I in bone tissue. However, this stimulatory effect appears to be limited to supraphysiological estrogen concentrations.

Animals↗
PubMed2004

The Fos-related antigen Fra-1 is an activator of bone matrix formation.

Ectopic expression of the transcription factor Fra-1 in transgenic mice leads to osteosclerosis, a bone disorder characterized by increased bone mass. The molecular basis for this phenotype is unknown and Fra-1 functions cannot be studied by a conventional loss-of-function approach, since fra-1-knockout mice die in utero likely due to placental defects. Here we show that the lethality of fra-1-knockout mice can be rescued by specific deletion of Fra-1 only in the mouse embryo and not in the placenta. Mice lacking Fra-1 (fra-1(delta/delta)) are viable and develop osteopenia, a low bone mass disease. Long bones of fra-1(delta/delta) mice appear to have normal osteoclasts but express reduced amounts of bone matrix components produced by osteoblasts and chondrocytes such as osteocalcin, collagen1a2 and matrix Gla protein. The gene for matrix Gla protein seems to be a specific target of Fra-1 since its expression was markedly increased in the long bones of fra-1-transgenic mice. These results uncover a novel function of Fra-1 in regulating bone mass through bone matrix production by osteoblasts and chondrocytes.

Animals↗
PubMed1986

Embryonic bone matrix formation is increased after exposure to a low-amplitude capacitively coupled electric field, in vitro.

In order to investigate the mechanism(s) of electric field-stimulated osteogenesis, we have developed an in vitro model in which embryonic chick tibiae have consistently demonstrated increased bone matrix formation in response to a low amplitude (estimated 10(-5) V/m in the serum-free culture medium), capacitively coupled, 10 Hz sinusoidal electric field. Initial applications of this model revealed that 72 h of continuous exposure to the electric field increased tibial collagen production by 29% compared to untreated controls, P less than 0.01. Additional studies further revealed: (a) that when electric field exposure was limited to 30 min/day during the 72 h in vitro incubation, embryonic bone matrix formation was increased by 83%, compared to non-treated controls (P less than 0.001), suggesting an inductive mechanism; (b) that the osteogenic response to electric field exposure in vitro was not unique to embryonic chick tibiae, since a similar response was also seen with newborn mouse calvaria (+133%, P less than 0.02); (c) that electric field-exposure-stimulated chick bone matrix formation was associated with increased bone cell proliferation; and (d) that this mitogenic response to in vitro electric field exposure could also be observed with embryonic chick calvarial cells in monolayer, serum-free cultures.

Animals↗