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Sample records for demineralized bone matrix

  1. Extraskeletal and intraskeletal new bone formation induced by demineralized bone matrix combined with bone marrow cells

    International Nuclear Information System (INIS)

    Lindholm, T.S.; Nilsson, O.S.; Lindholm, T.C.

    1982-01-01

    Dilutions of fresh autogenous bone marrow cells in combination with allogeneic demineralized cortical bone matrix were tested extraskeletally in rats using roentgenographic, histologic, and 45 Ca techniques. Suspensions of bone marrow cells (especially diluted 1:2 with culture media) combined with demineralized cortical bone seemed to induce significantly more new bone than did demineralized bone, bone marrow, or composite grafts with whole bone marrow, respectively. In a short-term spinal fusion experiment, demineralized cortical bone combined with fresh bone marrow produced new bone and bridged the interspace between the spinous processes faster than other transplantation procedures. The induction of undifferentiated host cells by demineralized bone matrix is further complemented by addition of autogenous, especially slightly diluted, bone marrow cells

  2. Demineralized dentin matrix composite collagen material for bone tissue regeneration.

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    Li, Jianan; Yang, Juan; Zhong, Xiaozhong; He, Fengrong; Wu, Xiongwen; Shen, Guanxin

    2013-01-01

    Demineralized dentin matrix (DDM) had been successfully used in clinics as bone repair biomaterial for many years. However, particle morphology of DDM limited it further applications. In this study, DDM and collagen were prepared to DDM composite collagen material. The surface morphology of the material was studied by scanning electron microscope (SEM). MC3T3-E1 cells responses in vitro and tissue responses in vivo by implantation of DDM composite collagen material in bone defect of rabbits were also investigated. SEM analysis showed that DDM composite collagen material evenly distributed and formed a porous scaffold. Cell culture and animal models results indicated that DDM composite collagen material was biocompatible and could support cell proliferation and differentiation. Histological evaluation showed that DDM composite collagen material exhibited good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that DDM composite collagen material might have a significant clinical advantage and potential to be applied in bone and orthopedic surgery.

  3. Bone induction by composite of bioerodible polyorthoester and demineralized bone matrix in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E; Bang, G

    1991-01-01

    A composite of a local, sustained, drug-release system, Alzamer bioerodible polyorthoester, and demineralized bone-matrix (DBM) particles implanted in the abdominal muscle of 89 Wistar rats induced cartilage and bone formation at the same rate as DBM when evaluated histologically and by 85Sr uptake....... The composite implant was technically easier to use than DBM alone....

  4. Injection of demineralized bone matrix with bone marrow concentrate improves healing in unicameral bone cyst.

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    Di Bella, Claudia; Dozza, Barbara; Frisoni, Tommaso; Cevolani, Luca; Donati, Davide

    2010-11-01

    Unicameral bone cysts are benign lesions that usually spontaneously regress with skeletal maturity; however, the high risk of pathologic fractures often justifies treatment that could reinforce a weakened bone cortex. Various treatments have been proposed but there is no consensus regarding the best procedure. We compared the healing rates and failures of two methods of cure based on multiple injections of corticosteroid or a single injection of demineralized bone matrix (DBM) in association with bone marrow concentrate (BMC). We retrospectively reviewed 184 patients who had one of the two treatments for unicameral bone cysts with cortical erosion. Clinical records were reviewed for treatment failures and radiographs for healing in all patients. The minimum followup was 12 months for the Steroids Group (mean, 48 months; range, 12-120 months) and 12 months for the DBM + BMC Group (mean, 20 months; range, 12-28 months). After one treatment we observed a lower healing rate of cysts treated with multiple injections of steroids compared with the healing after the first injection of DBM + BMC (21% versus 58%, respectively). At last followup, 38% healed with steroids and 71% with DBM + BMC. The rate of failure after one steroid injection was higher than after a single injection of BDM + BMC (63% versus 24%, respectively). We observed no difference in fracture rates after treatment between the two groups. A single injection of DBM added with autologous bone marrow concentrate appears to provide a higher healing rate with a lower number of failures compared with a single injection of steroids.

  5. Enhanced release of bone morphogenetic proteins from demineralized bone matrix by gamma irradiation

    International Nuclear Information System (INIS)

    Sung, Nak-Yun; Choi, Jong-il

    2015-01-01

    Gamma irradiation is a useful method for sterilizing demineralized bone matrix (DBM), but its effect on the osteoinductivity of DBM is still controversial. In this study, the osteoinductive activity of gamma-irradiated DBM was examined using a mouse myoblastic cell line (C2C12). DBM was extracted from adult bovine bone and was irradiated at a dose of 25 kGy using a 60 cobalt gamma-irradiator. Cell proliferation with DBM was not affected by gamma-irradiation, but alkaline phosphatase and osteocalcin productions were significantly increased in C2C12 cell groups treated with gamma-irradiated DBM. It was reasoned that bone morphogenetic proteins were more efficiently released from gamma-irradiated DBM than from the non-irradiated control. This result suggests the effectiveness of radiation sterilization of bone implants - Highlights: • Demineralized bone matrix (DBM) was gamma-irradiated for sterilization. • Irradiated DBM had higher alkaline phosphatase and osteocalcin production. • It was reasoned the more released bone morphogenetic proteins by irradiation. • This result supports the application of radiation sterilization for bone implants

  6. Autologous bone graft versus demineralized bone matrix in internal fixation of ununited long bones.

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    Pieske, Oliver; Wittmann, Alexandra; Zaspel, Johannes; Löffler, Thomas; Rubenbauer, Bianka; Trentzsch, Heiko; Piltz, Stefan

    2009-12-15

    Non-unions are severe complications in orthopaedic trauma care and occur in 10% of all fractures. The golden standard for the treatment of ununited fractures includes open reduction and internal fixation (ORIF) as well as augmentation with autologous-bone-grafting. However, there is morbidity associated with the bone-graft donor site and some patients offer limited quantity or quality of autologous-bone graft material. Since allogene bone-grafts are introduced on the market, this comparative study aims to evaluate healing characteristics of ununited bones treated with ORIF combined with either iliac-crest-autologous-bone-grafting (ICABG) or demineralized-bone-matrix (DBM). From 2000 to 2006 out of sixty-two consecutive patients with non-unions presenting at our Level I Trauma Center, twenty patients had ununited diaphyseal fractures of long bones and were treated by ORIF combined either by ICABG- (n = 10) or DBM-augmentation (n = 10). At the time of index-operation, patients of the DBM-group had a higher level of comorbidity (ASA-value: p = 0.014). Mean duration of follow-up was 56.6 months (ICABG-group) and 41.2 months (DBM-group). All patients were clinically and radiographically assessed and adverse effects related to bone grafting were documented. The results showed that two non-unions augmented with ICABG failed osseous healing (20%) whereas all non-unions grafted by DBM showed successful consolidation during the first year after the index operation (p = 0.146). No early complications were documented in both groups but two patients of the ICABG-group suffered long-term problems at the donor site (20%) (p = 0.146). Pain intensity were comparable in both groups (p = 0.326). However, patients treated with DBM were more satisfied with the surgical procedure (p = 0.031). With the use of DBM, the costs for augmentation of the non-union-site are more expensive compared to ICABG (calculated difference: 160 euro/case). Nevertheless, this study demonstrated that the

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

    Energy Technology Data Exchange (ETDEWEB)

    Severson, A.R. (Minnesota Univ., Duluth, MN (United States). Dept. of Anatomy and Cell Biology); Haut, C.F.; Firling, C.E. (Minnesota Univ., Duluth, MN (United States). Dept. of Biology); Huntley, T.E. (Minnesota Univ., Duluth, MN (United States). Dept. of Biochemistry and Molecular Biology)

    1992-12-01

    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. Thus, aluminum administration to rats appears to alter the differentiation and calcification of developing cartilage and bone in the DBM-induced bone formation model and suggests that aluminum by some mechanism alters the matrix calcification in growing bones. (orig.).

  8. Minimal invasive surgery for unicameral bone cyst using demineralized bone matrix: a case series

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    Cho Hwan

    2012-07-01

    Full Text Available Abstract Background Various treatments for unicameral bone cyst have been proposed. Recent concern focuses on the effectiveness of closed methods. This study evaluated the effectiveness of demineralized bone matrix as a graft material after intramedullary decompression for the treatment of unicameral bone cysts. Methods Between October 2008 and June 2010, twenty-five patients with a unicameral bone cyst were treated with intramedullary decompression followed by grafting of demineralized bone matrix. There were 21 males and 4 female patients with mean age of 11.1 years (range, 3–19 years. The proximal metaphysis of the humerus was affected in 12 patients, the proximal femur in five, the calcaneum in three, the distal femur in two, the tibia in two, and the radius in one. There were 17 active cysts and 8 latent cysts. Radiologic change was evaluated according to a modified Neer classification. Time to healing was defined as the period required achieving cortical thickening on the anteroposterior and lateral plain radiographs, as well as consolidation of the cyst. The patients were followed up for mean period of 23.9 months (range, 15–36 months. Results Nineteen of 25 cysts had completely consolidated after a single procedure. The mean time to healing was 6.6 months (range, 3–12 months. Four had incomplete healing radiographically but had no clinical symptom with enough cortical thickness to prevent fracture. None of these four cysts needed a second intervention until the last follow-up. Two of 25 patients required a second intervention because of cyst recurrence. All of the two had a radiographical healing of cyst after mean of 10 additional months of follow-up. Conclusions A minimal invasive technique including the injection of DBM could serve as an excellent treatment method for unicameral bone cysts.

  9. Minimal invasive surgery for unicameral bone cyst using demineralized bone matrix: a case series.

    Science.gov (United States)

    Cho, Hwan Seong; Seo, Sung Hwa; Park, So Hyun; Park, Jong Hoon; Shin, Duk Seop; Park, Il Hyung

    2012-07-29

    Various treatments for unicameral bone cyst have been proposed. Recent concern focuses on the effectiveness of closed methods. This study evaluated the effectiveness of demineralized bone matrix as a graft material after intramedullary decompression for the treatment of unicameral bone cysts. Between October 2008 and June 2010, twenty-five patients with a unicameral bone cyst were treated with intramedullary decompression followed by grafting of demineralized bone matrix. There were 21 males and 4 female patients with mean age of 11.1  years (range, 3-19 years). The proximal metaphysis of the humerus was affected in 12 patients, the proximal femur in five, the calcaneum in three, the distal femur in two, the tibia in two, and the radius in one. There were 17 active cysts and 8 latent cysts. Radiologic change was evaluated according to a modified Neer classification. Time to healing was defined as the period required achieving cortical thickening on the anteroposterior and lateral plain radiographs, as well as consolidation of the cyst. The patients were followed up for mean period of 23.9 months (range, 15-36 months). Nineteen of 25 cysts had completely consolidated after a single procedure. The mean time to healing was 6.6 months (range, 3-12 months). Four had incomplete healing radiographically but had no clinical symptom with enough cortical thickness to prevent fracture. None of these four cysts needed a second intervention until the last follow-up. Two of 25 patients required a second intervention because of cyst recurrence. All of the two had a radiographical healing of cyst after mean of 10 additional months of follow-up. A minimal invasive technique including the injection of DBM could serve as an excellent treatment method for unicameral bone cysts.

  10. BONE REGENERATION AFTER DEMINERALIZED BONE MATRIX AND CASTOR OIL (RICINUS COMMUNIS) POLYURETHANE IMPLANTATION

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    Leite, Fábio Renato Manzolli; Ramalho, Lizeti Toledo de Oliveira

    2008-01-01

    Innocuous biocompatible materials have been searched to repair or reconstruct bone defects. Their goal is to restore the function of live or dead tissues. This study compared connective tissue and bone reaction when exposed to demineralized bovine bone matrix and a polyurethane resin derived from castor bean (Ricinus communis). Forty-five rats were assigned to 3 groups of 15 animals (control, bovine bone and polyurethane). A cylindrical defect was created on mandible base and filled with bovine bone matrix and the polyurethane. Control group received no treatment. Analyses were performed after 15, 45 and 60 days (5 animals each). Histological analysis revealed connective tissue tolerance to bovine bone with local inflammatory response similar to that of the control group. After 15 days, all groups demonstrated similar outcomes, with mild inflammatory reaction, probably due to the surgical procedure rather than to the material. In the polymer group, after 60 days, scarce multinucleated cells could still be observed. In general, all groups showed good stability and osteogenic connective tissue with blood vessels into the surgical area. The results suggest biocompatibility of both materials, seen by their integration into rat mandible. Moreover, the polyurethane seems to be an alternative in bone reconstruction and it is an inexhaustible source of biomaterial. PMID:19089203

  11. Treatment of active unicameral bone cysts with percutaneous injection of demineralized bone matrix and autogenous bone marrow.

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    Rougraff, Bruce T; Kling, Thomas J

    2002-06-01

    The treatment of unicameral bone cysts varies from open bone-grafting procedures to percutaneous injection of corticosteroids or bone marrow. The purpose of this study was to evaluate the feasibility and effectiveness of percutaneous injection of a mixture of demineralized bone matrix and autogenous bone marrow for the treatment of simple bone cysts. Twenty-three patients with an active unicameral bone cyst were treated with trephination and injection of allogeneic demineralized bone matrix and autogenous bone marrow. The patients were followed for an average of fifty months (range, thirty to eighty-one months), at which time pain, function, and radiographic signs of resolution of the cyst were assessed. The average time until the patients had pain relief was five weeks, and the average time until the patients returned to full, unrestricted activities was six weeks. Bone-healing at the site of the injection was first seen radiographically at three to six months. No patient had a pathologic fracture during this early bone-healing stage. Cortical remodeling was seen radiographically by six to nine months, and after one year the response was usually complete, changing very little from then on. Five patients required a second injection because of recurrence of the cyst, and all five had a clinically and radiographically quiescent cyst after an average of thirty-six additional months of follow-up. Seven of the twenty-three patients had incomplete healing manifested by small, persistent radiolucent areas within the original cyst. None of these cysts increased in size or resulted in pain or fracture. Percutaneous injection of allogeneic demineralized bone matrix and autogenous bone marrow is an effective treatment for unicameral bone cysts.

  12. The effect of carrier type on bone regeneration of demineralized bone matrix in vivo.

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    Tavakol, Shima; Khoshzaban, Ahad; Azami, Mahmoud; Kashani, Iraj Ragerdi; Tavakol, Hani; Yazdanifar, Mahbube; Sorkhabadi, Seyed Mahdi Rezayat

    2013-11-01

    Demineralized bone matrix (DBM) is a bone substitute biomaterial used as an excellent grafting material. Some factors such as carrier type might affect the healing potential of this material. The background data discuss the present status of the field: Albumin as a main protein in blood and carboxymethyl cellulose (CMC) were applied frequently in the DBM gels. We investigated the bone-repairing properties of 2 DBMs with different carriers. Bone regeneration in 3 groups of rat calvaria treated with DBM from the Iranian Tissue Bank Research and Preparation Center, DBM from Hans Biomed Corporation, and an empty cavity was studied. Albumin and CMC as carriers were used. The results of bone regeneration in the samples after 1, 4, and 8 weeks of implantation were compared. The block of the histologic samples was stained with hematoxylin and eosin, and the percentage area of bone formation was calculated using the histomorphometry method. The results of in vivo tests showed a significantly stronger new regenerated bone occupation in the DBM with albumin carrier compared with the one with CMC 8 weeks after the implantation. The 2 types of DBM had a significant difference in bone regeneration. This difference is attributed to the type of carriers. Albumin could improve mineralization and bioactivity compared with CMC.

  13. Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    Best Poster 5Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants AuthorsBabiker , H.; Ding M.; Overgaard S.InstitutionOrthopaedic Research Laboratory, Department of Orthopaedic Surgery, Odense University Hospital, Clinical Institute, University of Southern...... from human tissue were included (IsoTis OrthoBiologics, Inc. USA). Both materials are commercially available. Titanium alloy implants (Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted bilaterally into the femoral condyles of 8 skeletally mature sheep. Thus four implants...... with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: DBM; DBM/CB with ratio of 1/3; DBM/allograft with ratio of 1/3; or allograft (Gold standard), respectively. Standardised surgical procedure was used1. At sacrifice, 6 weeks after surgery, both distal femurs were harvested...

  14. Intervariability and intravariability of bone morphogenetic proteins in commercially available demineralized bone matrix products.

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    Bae, Hyun W; Zhao, Li; Kanim, Linda E A; Wong, Pamela; Delamarter, Rick B; Dawson, Edgar G

    2006-05-20

    Enzyme-linked immunosorbent assay was used to detect bone morphogenetic proteins (BMPs) 2, 4, and 7 in 9 commercially available ("off the shelf") demineralized bone matrix (DBM) product formulations using 3 different manufacturer's production lots of each DBM formulation. To evaluate and compare the quantity of BMPs among several different DBM formulations (inter-product variability), as well as examine the variability of these proteins in different production lots within the same DBM formulation (intra-product variability). DBMs are commonly used to augment available bone graft in spinal fusion procedures. Surgeons are presented with an ever-increasing variety of commercially available human DBMs from which to choose. Yet, there is limited information on a specific DBM product's osteoinductive efficacy, potency, and constancy. There were protein extracts from each DBM sample separately dialyzed 4 times against distilled water at 4 degrees C for 48 hours. The amount of BMP-2, BMP-4, and BMP-7 was determined using enzyme-linked immunosorbent assay. RESULTS.: The concentrations of detected BMP-2 and BMP-7 were low for all DBM formulations, only nanograms of BMP were extracted from each gram of DBM (20.2-120.6 ng BMP-2/g DBM product; 54.2-226.8 ng BMP-7/g DBM). The variability of BMP concentrations among different lots of the same DBM formulation, intra-product variability, was higher than the variability of concentrations among different DBM formulations, inter-product variability (coefficient of variation range BMP-2 [16.34% to 76.01%], P DBMs are low, in the order of 1 x 10(-9) g of BMP/g of DBM. There is higher variability in concentration of BMPs among 3 different lots of the same DBM formulation than among different DBM formulations. This variability questions DBM products' reliability and, possibly, efficacy in providing consistent osteoinduction.

  15. Local effect of zoledronic acid on new bone formation in posterolateral spinal fusion with demineralized bone matrix in a murine model.

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    Zwolak, Pawel; Farei-Campagna, Jan; Jentzsch, Thorsten; von Rechenberg, Brigitte; Werner, Clément M

    2018-01-01

    Posterolateral spinal fusion is a common orthopaedic surgery performed to treat degenerative and traumatic deformities of the spinal column. In posteriolateral spinal fusion, different osteoinductive demineralized bone matrix products have been previously investigated. We evaluated the effect of locally applied zoledronic acid in combination with commercially available demineralized bone matrix putty on new bone formation in posterolateral spinal fusion in a murine in vivo model. A posterolateral sacral spine fusion in murine model was used to evaluate the new bone formation. We used the sacral spine fusion model to model the clinical situation in which a bone graft or demineralized bone matrix is applied after dorsal instrumentation of the spine. In our study, group 1 received decortications only (n = 10), group 2 received decortication, and absorbable collagen sponge carrier, group 3 received decortication and absorbable collagen sponge carrier with zoledronic acid in dose 10 µg, group 4 received demineralized bone matrix putty (DBM putty) plus decortication (n = 10), and group 5 received DBM putty, decortication and locally applied zoledronic acid in dose 10 µg. Imaging was performed using MicroCT for new bone formation assessment. Also, murine spines were harvested for histopathological analysis 10 weeks after surgery. The surgery performed through midline posterior approach was reproducible. In group with decortication alone there was no new bone formation. Application of demineralized bone matrix putty alone produced new bone formation which bridged the S1-S4 laminae. Local application of zoledronic acid to demineralized bone matrix putty resulted in significant increase of new bone formation as compared to demineralized bone matrix putty group alone. A single local application of zoledronic acid with DBM putty during posterolateral fusion in sacral murine spine model increased significantly new bone formation in situ in our model. Therefore, our

  16. Localized ridge defect augmentation using human pericardium membrane and demineralized bone matrix.

    Science.gov (United States)

    Vidyadharan, Arun Kumar; Ravindran, Anjana

    2014-01-01

    Patient wanted to restore her lost teeth with implants in the lower left first molar and second premolar region. Cone beam computerized tomography (CBCT) revealed inadequate bone width and height around future implant sites. The extraction socket of second premolar area revealed inadequate socket healing with sparse bone fill after 4 months of extraction. To evaluate the clinical feasibility of using a collagen physical resorbable barrier made of human pericardium (HP) to augment localized alveolar ridge defects for the subsequent placement of dental implants. Ridge augmentation was done in the compromised area using Puros® demineralized bone matrix (DBM) Putty with chips and an HP allograft membrane. Horizontal (width) and vertical hard tissue measurements with CBCT were recorded on the day of ridge augmentation surgery, 4 month and 7 months follow-up. Intra oral periapical taken 1 year after implant installation showed minimal crestal bone loss. Bone volume achieved through guided bone regeneration was a gain of 4.8 mm horizontally (width) and 6.8 mm vertically in the deficient ridge within a period of 7 months following the procedure. The results suggested that HP Allograft membrane may be a suitable component for augmentation of localized alveolar ridge defects in conjunction with DBM with bone chips.

  17. Demineralized bone matrix fibers formable as general and custom 3D printed mold-based implants for promoting bone regeneration.

    Science.gov (United States)

    Rodriguez, Rudy U; Kemper, Nathan; Breathwaite, Erick; Dutta, Sucharita M; Hsu, Erin L; Hsu, Wellington K; Francis, Michael P

    2016-07-26

    Bone repair frequently requires time-consuming implant construction, particularly when using un-formed implants with poor handling properties. We therefore developed osteoinductive, micro-fibrous surface patterned demineralized bone matrix (DBM) fibers for engineering both defect-matched and general three-dimensional implants. Implant molds were filled with demineralized human cortical bone fibers there were compressed and lyophilized, forming mechanically strong shaped DBM scaffolds. Enzyme linked immunosorbent assays and mass spectrometry confirmed that DBM fibers contained abundant osteogenic growth factors (bone morphogenetic proteins, insulin-like growth factor-I) and extracellular matrix proteins. Mercury porosimetry and mechanical testing showed interconnected pores within the mechanically stable, custom DBM fiber scaffolds. Mesenchymal stem cells readily attached to the DBM and showed increasing metabolic activity over time. DBM fibers further increased alkaline phosphatase activity in C2C12 cells. In vivo, DBM implants elicited osteoinductive potential in a mouse muscle pouch, and also promoted spine fusion in a rat arthrodesis model. DBM fibers can be engineered into custom-shaped, osteoinductive and osteoconductive implants with potential for repairing osseous defects with precise fitment, potentially reducing operating time. By providing pre-formed and custom implants, this regenerative allograft may improve patient outcomes following surgical bone repair, while further advancing personalized orthopedic and craniomaxillofacial medicine using three-dimensional-printed tissue molds.

  18. Influence of demineralized bone matrix's embryonic origin on bone formation: an experimental study in rats.

    Science.gov (United States)

    Stavropoulos, Andreas; Kostopoulos, Lambros; Mardas, Nicolaos; Karring, Thorkild

    2003-01-01

    There are results suggesting that differences regarding bone-inducing potential, in terms of amount and/or rate of bone formation, exist between demineralized bone matrices (DBMs) of different embryonic origins. The aim of the present study was to examine whether the embryonic origin of DBM affects bone formation when used as an adjunct to guided tissue regeneration (GTR). Endomembranous (EM) and endochondral (ECH) DBMs were produced from calvarial and long bones of rats, respectively. Prior to the study the osteoinductive properties of the DBMs were confirmed in six rats following intramuscular implantation. Following surgical exposure of the mandibular ramus, a rigid hemispheric Teflon capsule loosely packed with a standardized quantity of DBM was placed with its open part facing the lateral surface of the ramus in both sides of the jaw in 30 rats. In one side of the jaw, chosen at random, the capsule was filled with EM-DBM, whereas in the other side ECH-DBM was used. Groups of 10 animals were sacrificed after healing periods of 1, 2, and 4 months, and undecalcified sections of the capsules were produced and subjected to histologic analysis and computer-assisted planimetric measurements. During the experiment increasing amounts of newly formed bone were observed inside the capsules in both sides of the animals' jaws. Limited bone formation was observed in the 1- and 2-month specimens, but after 4 months of healing, the newly formed bone in the ECH-DBM grafted sides occupied 59.1% (range 45.6-74.7%) of the area created by the capsule versus 46.9% (range 23.0-64.0%) in the EM-DBM grafted sides (p =.01). It is concluded that the embryonic origin of DBM influences bone formation by GTR and that ECH-DBM is superior to EM-DBM.

  19. Serum albumin coating of demineralized bone matrix results in stronger new bone formation.

    Science.gov (United States)

    Horváthy, Dénes B; Vácz, Gabriella; Szabó, Tamás; Szigyártó, Imola C; Toró, Ildikó; Vámos, Boglárka; Hornyák, István; Renner, Károly; Klára, Tamás; Szabó, Bence T; Dobó-Nagy, Csaba; Doros, Attila; Lacza, Zsombor

    2016-01-01

    Blood serum fractions are hotly debated adjuvants in bone replacement therapies. In the present experiment, we coated demineralized bone matrices (DBM) with serum albumin and investigated stem cell attachment in vitro and bone formation in a rat calvaria defect model. In the in vitro experiments, we observed that significantly more cells adhere to the serum albumin coated DBMs at every time point. In vivo bone formation with albumin coated and uncoated DBM was monitored biweekly by computed tomography until 11 weeks postoperatively while empty defects served as controls. By the seventh week, the bone defect in the albumin group was almost completely closed (remaining defect 3.0 ± 2.3%), while uncoated DBM and unfilled control groups still had significant defects (uncoated: 40.2 ± 9.1%, control: 52.4 ± 8.9%). Higher density values were also observed in the albumin coated DBM group. In addition, the serum albumin enhanced group showed significantly higher volume of newly formed bone in the microCT analysis and produced significantly higher breaking force and stiffness compared to the uncoated grafts (peak breaking force: uncoated: 15.7 ± 4 N, albumin 46.1 ± 11 N). In conclusion, this investigation shows that implanting serum albumin coated DBM significantly reduces healing period in nonhealing defects and results in mechanically stronger bone. These results also support the idea that serum albumin coating provides a convenient milieu for stem cell function, and a much improved bone grafting success can be achieved without the use of exogenous stem cells. © 2015 Wiley Periodicals, Inc.

  20. A composite demineralized bone matrix--self assembling peptide scaffold for enhancing cell and growth factor activity in bone marrow.

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    Hou, Tianyong; Li, Zhiqiang; Luo, Fei; Xie, Zhao; Wu, Xuehui; Xing, Junchao; Dong, Shiwu; Xu, Jianzhong

    2014-07-01

    The need for suitable bone grafts is high; however, there are limitations to all current graft sources, such as limited availability, the invasive harvest procedure, insufficient osteoinductive properties, poor biocompatibility, ethical problems, and degradation properties. The lack of osteoinductive properties is a common problem. As an allogenic bone graft, demineralized bone matrix (DBM) can overcome issues such as limited sources and comorbidities caused by invasive harvest; however, DBM is not sufficiently osteoinductive. Bone marrow has been known to magnify osteoinductive components for bone reconstruction because it contains osteogenic cells and factors. Mesenchymal stem cells (MSCs) derived from bone marrow are the gold standard for cell seeding in tissue-engineered biomaterials for bone repair, and these cells have demonstrated beneficial effects. However, the associated high cost and the complicated procedures limit the use of tissue-engineered bone constructs. To easily enrich more osteogenic cells and factors to DBM by selective cell retention technology, DBM is modified by a nanoscale self-assembling peptide (SAP) to form a composite DBM/SAP scaffold. By decreasing the pore size and increasing the charge interaction, DBM/SAP scaffolds possess a much higher enriching yield for osteogenic cells and factors compared with DBM alone scaffolds. At the same time, SAP can build a cellular microenvironment for cell adhesion, proliferation, and differentiation that promotes bone reconstruction. As a result, a suitable bone graft fabricated by DBM/SAP scaffolds and bone marrow represents a new strategy and product for bone transplantation in the clinic. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Chest wall reconstruction in a canine model using polydioxanone mesh, demineralized bone matrix and bone marrow stromal cells.

    Science.gov (United States)

    Tang, Hua; Xu, Zhifei; Qin, Xiong; Wu, Bin; Wu, Lihui; Zhao, XueWei; Li, Yulin

    2009-07-01

    Extensive chest wall defect reconstruction remains a challenging problem for surgeons. In the past several years, little progress has been made in this area. In this study, a biodegradable polydioxanone (PDO) mesh and demineralized bone matrix (DBM) seeded with osteogenically induced bone marrow stromal cells (BMSCs) were used to reconstruct a 6 cm x 5.5 cm chest wall defect. Four experimental groups were evaluated (n=6 per group): polydioxanone (PDO) mesh/DBMs/BMSCs group, polydioxanone (PDO) mesh/DBMs group, polydioxanone (PDO) mesh group, and a blank group (no materials) in a canine model. All the animals survived except those in the blank group. In all groups receiving biomaterial implants, the polydioxanone (PDO) mesh completely degraded at 24 weeks and was replaced by fibrous tissue with thickness close to that of the normal intercostal tissue (P>0.05). In the polydioxanone (PDO) mesh/DBMs/BMSCs group, new bone formation and bone-union were observed by radiographic and histological examination. More importantly, the reconstructed rib could maintain its original radian and achieve satisfactory biomechanics close to normal ribs in terms of bending stress (P>0.05). However, in the other two groups, fibrous tissue was observed in the defect and junctions, and the reconstructed ribs were easily distorted under an outer force. Based on these results, a surgical approach utilizing biodegradable polydioxanone (PDO) mesh in combination with DBMs and BMSCs could repair the chest wall defect not only in function but also in structure.

  2. A Comparative Analysis of Recombinant Human Bone Morphogenetic Protein-2 with a Demineralized Bone Matrix versus Iliac Crest Bone Graft for Secondary Alveolar Bone Grafts in Patients with Cleft Lip and Palate: Review of 501 Cases.

    Science.gov (United States)

    Hammoudeh, Jeffrey A; Fahradyan, Artur; Gould, Daniel J; Liang, Fan; Imahiyerobo, Thomas; Urbinelli, Leo; Nguyen, JoAnna T; Magee, William; Yen, Stephen; Urata, Mark M

    2017-08-01

    Alveolar cleft reconstruction using iliac crest bone graft is considered standard of care for children with complete cleft lip and palate at the time of mixed dentition. Harvesting bone may result in donor-site morbidity and additional operating time and length of hospitalization. Recombinant human bone morphogenetic protein (rhBMP)-2 with a demineralized bone matrix is an alternative bone source for alveolar cleft reconstruction. The authors investigated the outcomes of rhBMP-2/demineralized bone matrix versus iliac crest bone graft for alveolar cleft reconstruction by reviewing postoperative surgical complications and cleft closure. A retrospective chart review was conducted for 258 rhBMP-2/demineralized bone matrix procedures (mean follow-up, 2.9 years) and 243 iliac crest bone graft procedures (mean follow-up, 4.1 years) on 414 patients over a 12-year period. The authors compared complications, canine eruption, and alveolar cleft closure between the two groups. In the rhBMP-2/demineralized bone matrix group, one patient required prolonged intubation because of intraoperative airway swelling not thought to be caused by rhBMP-2, 36 reported facial swelling and one required outpatient steroids as treatment, and 12 had dehiscence; however, half of these complications resolved without intervention. Twenty-three of the 228 rhBMP-2/demineralized bone matrix patients and 28 of the 242 iliac crest bone graft patients required repeated surgery for alveolar cleft repair. Findings for canine tooth eruption into the cleft site through the graft were similar between the groups. The rhBMP-2/demineralized bone matrix appears to be an acceptable alternative for alveolar cleft repair. The authors found no increase in serious adverse events with the use of this material. Local complications, such as swelling and minor wound dehiscence, predominantly improved without intervention. Therapeutic, III.

  3. In vitro evaluation of demineralized freeze-dried bone allograft in combination with enamel matrix derivative.

    Science.gov (United States)

    Miron, Richard J; Bosshardt, Dieter D; Laugisch, Oliver; Dard, Michel; Gemperli, Anja C; Buser, Daniel; Gruber, Reinhard; Sculean, Anton

    2013-11-01

    Preclinical and clinical studies suggest that a combination of enamel matrix derivative (EMD) with demineralized freeze-dried bone allograft (DFDBA) may improve periodontal wound healing and regeneration. To date, no single study has characterized the effects of this combination on in vitro cell behavior. The aim of this study is to test the ability of EMD to adsorb to the surface of DFDBA particles and determine the effect of EMD coating on downstream cellular pathways such as adhesion, proliferation, and differentiation of primary human osteoblasts and periodontal ligament (PDL) cells. DFDBA particles were precoated with EMD or human blood and analyzed for protein adsorption patterns via scanning electron microscopy. Cell attachment and proliferation were quantified using a commercial assay. Cell differentiation was analyzed using real-time polymerase chain reaction for genes encoding Runx2, alkaline phosphatase, osteocalcin, and collagen 1α1, and mineralization was assessed using alizarinred staining. Analysis of cell attachment revealed no significant differences among control, blood-coated, and EMD-coated DFDBA particles. EMD significantly increased cell proliferation at 3 and 5 days after seeding for both osteoblasts and PDL cells compared to control and blood-coated samples. Moreover, there were significantly higher messenger ribonucleic acid levels of osteogenic differentiation markers, including collagen 1α1, alkaline phosphatase, and osteocalcin, in osteoblasts and PDL cells cultured on EMD-coated DFDBA particles at 3, 7, and 14 days. The results suggest that the addition of EMD to DFDBA particles may influence periodontal regeneration by stimulating PDL cell and osteoblast proliferation and differentiation.

  4. In vivo performance of combinations of autograft, demineralized bone matrix, and tricalcium phosphate in a rabbit femoral defect model

    International Nuclear Information System (INIS)

    Kim, Jinku; McBride, Sean; Hollinger, Jeffrey O; Dean, David D; Sylvia, Victor L; Doll, Bruce A

    2014-01-01

    Large bone defects may be treated with autologous or allogeneic bone preparations. Each treatment has advantages and disadvantages; therefore, a clinically viable option for treating large (e.g., gap) bone defects may be a combination of the two. In the present study, bone repair was determined with combinations of autografts, allografts, and synthetic bone grafts using an established rabbit femoral defect model. Bilateral unicortical femoral defects were surgically prepared and treated with combinatorial bone grafts according to one of seven treatment groups. Recipient sites were retrieved at six weeks. Cellular/tissue responses and new bone formation were assessed by histology and histomorphometry. Histological analysis images indicated neither evidence of inflammatory, immune responses, tissue necrosis, nor osteolysis. Data suggested co-integration of implanted agents with host and newly formed bone. Finally, the histomorphometric data suggested that the tricalcium phosphate-based synthetic bone graft substitute allowed new bone formation that was similar to the allograft (i.e., demineralized bone matrix, DBM). (paper)

  5. Injection of Unicameral Bone Cysts with Bone Marrow Aspirate and Demineralized Bone Matrix Avoids Open Curettage and Bone Grafting in a Retrospective Cohort.

    Science.gov (United States)

    Gundle, Kenneth R; Bhatt, Etasha M; Punt, Stephanie E; Bompadre, Viviana; Conrad, Ernest U

    2017-01-01

    Many treatment options exist for unicameral bone cysts (UBC), without clear evidence of superiority. Meta-analyses have been limited by small numbers of patients in specific anatomic and treatment subgroups. The purpose of this study was to report the outcomes of injecting bone marrow aspirate and demineralized bone matrix (BMA/DBM) for the treatment of proximal humerus UBC. Fifty-one patients with proximal humerus lesions treated by BMA/DBM injection were retrospectively reviewed from a single academic medical center. The mean number of injections performed per patient was 2.14 (range 1-5). Eleven patients underwent only one injection (22%), an additional 19 patients completed treatment after two injections (37%), four patients healed after three injections (8%), and one patient healed after four injections (2%). The cumulative success rate of serial BMA/DBM injections was 22% (11/51), 58% (30/51), 67% (34/51), and 69% (35/51). Eleven patients (22%) ultimately underwent open curettage and bone grafting, and five patients (10%) were treated with injection of calcium phosphate bone substitute. A BMA/DBM injection strategy avoided an open procedure in 78% of patients with a proximal humerus UBC. The majority of patients underwent at least 2 injection treatments. Level IV retrospective cohort study.

  6. Experimental Evaluation of the Effectiveness of Demineralized Bone Matrix and Collagenated Heterologous Bone Grafts Used Alone or in Combination with Platelet-Rich Fibrin on Bone Healing in Sinus Floor Augmentation.

    Science.gov (United States)

    Peker, Elif; Karaca, Inci Rana; Yildirim, Benay

    2016-01-01

    The aim of this study was an experimental evaluation of the effectiveness of demineralized bone matrix (DBM) and collagenated heterologous bone graft (CHBG) used alone or in combination with platelet-rich fibrin on bone healing in sinus floor augmentation procedures. In this study, 36 New Zealand rabbits were used. The bilateral sinus elevation was performed, and 72 defects were obtained. The rabbit maxillary sinuses were divided into four groups according to the augmentation biomaterials obtained: demineralized bone matrix (Grafton DBM Putty, Osteotech; DBM group), DBM combined with platelet-rich fibrin (PRF; DBM + PRF group), collagenated heterologous bone graft (CHBG; Apatos Mix, OsteoBiol, Tecnoss; CHBG group), CHBG combined with PRF (CHBG + PRF group). All groups were sacrificed at 2, 4, and 8 weeks after surgery for histologic, histomorphometric, and immunohistochemical analyses. The inflammatory reaction was moderate to intense at the second week in all groups and declined from 2 to 8 weeks. New bone formation was started at the second week and increased from 2 to 8 weeks in all groups. There was no significant difference in bone formation between the experimental groups that used PRF mixed graft material and control groups that used only graft material. The percentage of new bone formation showed a significant difference in DBM groups and DBM + PRF groups compared with other groups. There were osteoclasts around all the bone graft materials used, but the percentage of residual graft particles was significantly higher in CHBG groups and CHBG + PRF groups at the eighth week. There is no beneficial effect of the application of PRF in combination with demineralized bone matrix or collagenated heterologous bone graft on bone formation in sinus floor augmentation. The results of this study showed that both collagenated heterologous bone graft and demineralized bone matrix have osteoconductive properties, but demineralized bone matrix showed more bone formation

  7. When size matters: differences in demineralized bone matrix particles affect collagen structure, mesenchymal stem cell behavior, and osteogenic potential.

    Science.gov (United States)

    Dozza, B; Lesci, I G; Duchi, S; Della Bella, E; Martini, L; Salamanna, F; Falconi, M; Cinotti, S; Fini, M; Lucarelli, E; Donati, D

    2017-04-01

    Demineralized bone matrix (DBM) is a natural, collagen-based, osteoinductive biomaterial. Nevertheless, there are conflicting reports on the efficacy of this product. The purpose of this study was to evaluate whether DBM collagen structure is affected by particle size and can influence DBM cytocompatibility and osteoinductivity. Sheep cortical bone was ground and particles were divided in three fractions with different sizes, defined as large (L, 1-2 mm), medium (M, 0.5-1 mm), and small (S, structure, with DBM-M being altered but not as much as DBM-S. DBM-M displayed a preferable trend in almost all biological characteristics tested, although all DBM particles revealed an optimal cytocompatibility. Subcutaneous implantation of DBM particles into immunocompromised mice resulted in bone induction only for DBM-M. When sheep MSC were seeded onto particles before implantation, all DBM particles were able to induce new bone formation with the best incidence for DBM-M and DBM-S. In conclusion, the collagen alteration in DBM-M is likely the best condition to promote bone induction in vivo. Furthermore, the choice of 0.5-1 mm particles may enable to obtain more efficient and consistent results among different research groups in bone tissue-engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1019-1033, 2017. © 2017 Wiley Periodicals, Inc.

  8. Three-Dimensional Cone Beam Computed Tomography Volumetric Outcomes of rhBMP-2/Demineralized Bone Matrix versus Iliac Crest Bone Graft for Alveolar Cleft Reconstruction.

    Science.gov (United States)

    Liang, Fan; Yen, Stephen L-K; Imahiyerobo, Thomas; Sanborn, Luke; Yen, Leia; Yen, Daniel; Nazarian, Sheila; Jedrzejewski, Breanna; Urata, Mark; Hammoudeh, Jeffrey

    2017-10-01

    Recent studies indicate that recombinant human bone morphogenetic protein-2 (rhBMP-2) in a demineralized bone matrix scaffold is a comparable alternative to iliac bone autograft in the setting of secondary alveolar cleft repair. Postreconstruction occlusal radiographs demonstrate improved bone stock when rhBMP-2/demineralized bone matrix (DBM) scaffold is used but lack the capacity to evaluate bone growth in three dimensions. This study uses cone beam computed tomography to provide the first clinical evaluation of volumetric and density comparisons between these two treatment modalities. A prospective study was conducted with 31 patients and 36 repairs of the alveolar cleft over a 2-year period. Twenty-one repairs used rhBMP-2/DBM scaffold and 14 repairs used iliac bone grafting. Postoperatively, occlusal radiographs were obtained at 3 months to evaluate bone fill; cone beam computed tomographic images were obtained at 6 to 9 months to compare volumetric and density data. At 3 months, postoperative occlusal radiographs demonstrated that 67 percent of patients receiving rhBMP-2/DBM scaffold had complete bone fill of the alveolus, versus 56 percent of patients in the autologous group. In contrast, cone beam computed tomographic data showed 31.6 percent (95 percent CI, 24.2 to 38.5 percent) fill in the rhBMP-2 group compared with 32.5 percent (95 percent CI, 22.1 to 42.9 percent) in the autologous population. Density analysis demonstrated identical average values between the groups (1.38 g/cc). These data demonstrate comparable bone regrowth and density values following secondary alveolar cleft repair using rhBMP-2/DBM scaffold versus autologous iliac bone graft. Cone beam computed tomography provides a more nuanced understanding of true bone regeneration within the alveolar cleft that may contribute to the information provided by occlusal radiographs alone. Therapeutic, II.

  9. A composite scaffold of MSC affinity peptide-modified demineralized bone matrix particles and chitosan hydrogel for cartilage regeneration

    Science.gov (United States)

    Meng, Qingyang; Man, Zhentao; Dai, Linghui; Huang, Hongjie; Zhang, Xin; Hu, Xiaoqing; Shao, Zhenxing; Zhu, Jingxian; Zhang, Jiying; Fu, Xin; Duan, Xiaoning; Ao, Yingfang

    2015-12-01

    Articular cartilage injury is still a significant challenge because of the poor intrinsic healing potential of cartilage. Stem cell-based tissue engineering is a promising technique for cartilage repair. As cartilage defects are usually irregular in clinical settings, scaffolds with moldability that can fill any shape of cartilage defects and closely integrate with the host cartilage are desirable. In this study, we constructed a composite scaffold combining mesenchymal stem cells (MSCs) E7 affinity peptide-modified demineralized bone matrix (DBM) particles and chitosan (CS) hydrogel for cartilage engineering. This solid-supported composite scaffold exhibited appropriate porosity, which provided a 3D microenvironment that supports cell adhesion and proliferation. Cell proliferation and DNA content analysis indicated that the DBM-E7/CS scaffold promoted better rat bone marrow-derived MSCs (BMMSCs) survival than the CS or DBM/CS groups. Meanwhile, the DBM-E7/CS scaffold increased matrix production and improved chondrogenic differentiation ability of BMMSCs in vitro. Furthermore, after implantation in vivo for four weeks, compared to those in control groups, the regenerated issue in the DBM-E7/CS group exhibited translucent and superior cartilage-like structures, as indicated by gross observation, histological examination, and assessment of matrix staining. Overall, the functional composite scaffold of DBM-E7/CS is a promising option for repairing irregularly shaped cartilage defects.

  10. Demineralized bone matrix and human cancellous bone enhance fixation of porous-coated titanium implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2016-01-01

    matrix (DBM), alone or in combination with allograft or commercially available human cancellous bone (CB), may replace allografts, as they have the capability of inducing new bone and improving implant fixation through enhancing bone ongrowth. The purpose of this study was to investigate the effect...... of DBM alone, DBM with CB, or allograft on the fixation of porous-coated titanium implants. DBM100 and CB produced from human tissue were included. Both materials are commercially available. DBM granules are placed in pure DBM and do not contain any other carrier. Titanium alloy implants, 10 mm long × 10...... mm diameter, were inserted bilaterally into the femoral condyles of eight skeletally mature sheep. Thus, four implants with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: (a) DBM; (b) DBM:CB at a ratio of 1:3; (c) DBM:allograft at a ratio of 1:3; or (d) allograft...

  11. Bone protein extraction without demineralization using principles from hydroxyapatite chromatography.

    Science.gov (United States)

    Cleland, Timothy P; Vashishth, Deepak

    2015-03-01

    Historically, extraction of bone proteins has relied on the use of demineralization to better retrieve proteins from the extracellular matrix; however, demineralization can be a slow process that restricts subsequent analysis of the samples. Here, we developed a novel protein extraction method that does not use demineralization but instead uses a methodology from hydroxyapatite chromatography where high concentrations of ammonium phosphate and ammonium bicarbonate are used to extract bone proteins. We report that this method has a higher yield than those with previously published small-scale extant bone extractions, with and without demineralization. Furthermore, after digestion with trypsin and subsequent high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis, we were able to detect several extracellular matrix and vascular proteins in addition to collagen I and osteocalcin. Our new method has the potential to isolate proteins within a short period (4h) and provide information about bone proteins that may be lost during demineralization or with the use of denaturing agents. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Combined effects of porous hydroxyapatite and demineralized bone matrix on bone induction: in vitro and in vivo study using a nude rat model

    International Nuclear Information System (INIS)

    Lee, Jae Hyup; Lee, Kyung-Mee; Baek, Hae-Ri; Jang, Soo-Jeong; Lee, Ji-Ho; Ryu, Hyun-Seung

    2011-01-01

    Hydroxyapatite (HA) is an osteoconductive material used as a bone graft extender and demineralized bone matrix (DBM) has been used as a source of osteoinductive factors. A combination of DBM and HA is expected to create a composite with both osteoconductive and osteoinductive properties. This study examined the effect of a combination of DBM and HA on osteogenesis both in vitro and in vivo using an athymic nude rat abdominal muscle pouch model, and evaluated the possibility of HA as a carrier of DBM. Alkaline phosphatase (ALP) staining, ALP assay and measurements of the mRNA expression of ALP and Runx2 by RT-PCR were performed by transplanting human mesenchymal stem cells onto a plate. Five athymic nude rats each were assigned to one of two experimental groups (DBM/HA putty and only HA, i.e. 15 pouches per group). The muscle pouches were filled with DBM/HA putty or only HA. Radiographs were obtained at weeks 4 and 8, postoperatively. The animals were sacrificed at week 8 postoperatively and high resolution microCT was used to confirm the newly formed mineralized tissue. Each pouch was fixed, embedded, sectioned and processed for hematoxylin and eosin staining. The ALP value of the DBM/HA putty was higher than those of HA and control (p < 0.05, each). The expression of ALP mRNA appeared higher on the DBM/HA putty than on HA and control. MicroCT and histology examinations of the DBM/HA putty demonstrated the presence of newly generated mineralized tissues but there was no mineralized tissue in the HA cases. In conclusion, the DBM/HA putty indicated osteoblastic differentiation in vitro and showed ectopic mineralized tissue formation in the rat abdominal pouch model. These findings indicate that the DBM/HA putty can retain its oteoinductivity and HA can be used as a carrier of DBM.

  13. Combined effects of porous hydroxyapatite and demineralized bone matrix on bone induction: in vitro and in vivo study using a nude rat model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Hyup; Lee, Kyung-Mee; Baek, Hae-Ri; Jang, Soo-Jeong; Lee, Ji-Ho [Department of Orthopedic Surgery, Seoul National University School of Medicine, SMG-SNU Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Ryu, Hyun-Seung, E-mail: spinelee@snu.ac.kr [Research and Development Center, CGBio Inc., Seong-Nam 462-120 (Korea, Republic of)

    2011-02-15

    Hydroxyapatite (HA) is an osteoconductive material used as a bone graft extender and demineralized bone matrix (DBM) has been used as a source of osteoinductive factors. A combination of DBM and HA is expected to create a composite with both osteoconductive and osteoinductive properties. This study examined the effect of a combination of DBM and HA on osteogenesis both in vitro and in vivo using an athymic nude rat abdominal muscle pouch model, and evaluated the possibility of HA as a carrier of DBM. Alkaline phosphatase (ALP) staining, ALP assay and measurements of the mRNA expression of ALP and Runx2 by RT-PCR were performed by transplanting human mesenchymal stem cells onto a plate. Five athymic nude rats each were assigned to one of two experimental groups (DBM/HA putty and only HA, i.e. 15 pouches per group). The muscle pouches were filled with DBM/HA putty or only HA. Radiographs were obtained at weeks 4 and 8, postoperatively. The animals were sacrificed at week 8 postoperatively and high resolution microCT was used to confirm the newly formed mineralized tissue. Each pouch was fixed, embedded, sectioned and processed for hematoxylin and eosin staining. The ALP value of the DBM/HA putty was higher than those of HA and control (p < 0.05, each). The expression of ALP mRNA appeared higher on the DBM/HA putty than on HA and control. MicroCT and histology examinations of the DBM/HA putty demonstrated the presence of newly generated mineralized tissues but there was no mineralized tissue in the HA cases. In conclusion, the DBM/HA putty indicated osteoblastic differentiation in vitro and showed ectopic mineralized tissue formation in the rat abdominal pouch model. These findings indicate that the DBM/HA putty can retain its oteoinductivity and HA can be used as a carrier of DBM.

  14. Efficacy comparison of Accell Evo3 and Grafton demineralized bone matrix putties against autologous bone in a rat posterolateral spine fusion model.

    Science.gov (United States)

    Brecevich, Antonio T; Kiely, Paul D; Yoon, B Victor; Nguyen, Joseph T; Cammisa, Frank P; Abjornson, Celeste

    2017-06-01

    Spinal fusion procedures are intended to stabilize the spinal column for a multitude of disorders including abnormal curvature, traumatic instability, degenerative instability, and damage from infections or tumors. As an aid in the bone healing response, bone graft materials are used to bridge joints for arthrodesis and promote unions in pseudoarthrosis. Currently, the gold standard for stabilizing fusion masses in spinal procedures involves using the osteogenic, osteoinductive, and osteoconductive properties of autologous iliac crest corticocancellous bone. However, considerable morbidity is associated with harvesting the autologous graft. Donor site complications including infection, large hematomas, and pain have been reported at rates as high as 50% (Boden and Jeffrey, 1995). Biologically, the rate of bone repair dictates the rate at which the fusion mass will unite under autologous graft conditions. The purpose of this study is to compare the quality and rate of fusion between Accell Evo3 and Grafton demineralized bone matrix (DBM), with the gold standard iliac crest bone graft (ICBG) as the control, in athymic rat posterolateral fusion. This study was a randomized, controlled study in a laboratory setting at the Hospital for Special Surgery in New York City. Blinded observations were made, which created an assessment of outcomes for successful fusions between each method. Forty-eight (48) athymic rats were used in this study and underwent posterolateral lumbar fusion. They were assessed at either 3 weeks or 9 weeks to see the rate and efficacy of fusion. Outcome measures will be the efficacy of the different bone grafts and their success rates of fusion in the rats. A comparison of the quality and rate of fusion between Accell Evo3® (DBM A) and Grafton (DBM B), with the gold standard iliac crest bone graft (ICBG) as the control, was performed using the established posterolateral intertransverse process on an athymic rat model. Materials were evaluated for

  15. Evaluation of Low Intensity Pulsed Ultrasound Effects on the Osteogenesis Potential of Demineralized Bone Matrix in Experimental Tibial Defect in Rabbits

    Directory of Open Access Journals (Sweden)

    Ezzati Givi

    2016-09-01

    Full Text Available Background Many studies have assessed the effects of either low intensity pulsed ultrasound (LIPUS or demineralized bone matrix (DBM on bone repair; however, an evaluation of the combination of these modalities (LIPUS + DBM has not yet been considered. Objectives This study aimed to investigate combined effects of DBM and LIPUS on fracture healing. Methods Bilateral 5-mm tibial defects were created in male Dutch rabbits (n = 30. Animals were divided to two groups of empty defect (A and DBM group (B, in which commercial DBM putty was used in defects. In each animal left tibia was treated with LIPUS (intensity = 30 mW/cm2, I SATA, 1 MHz, 20 min/day, pulsed duty 1:4 and the contralateral limb was used as the control. Animals, after 14, 28 and 60 days, were submitted to radiographic or computerized tomography (CT scanning analysis. Results At two weeks, LIPUS had no substantial effect on bone formation. Slight increase of average rates in LIPUS group (A2 were seen compared to the empty defect group (A1 at day 21 and 28. In the DBM–treated group compared with the sham LIPUS, bone-healing rate was reduced at the end of the period (60 days after surgery. The average healing rate in group B at the end of the 60-day period was less than group A after 21 days. Conclusions The present study discusses systemic effect of LIPUS because of non-significant results between treated group and control group and is the first to demonstrate that LIPUS decreases bone formation induced by DBM.

  16. Osteoinductive potential of demineralized rat bone increases with increasing donor age from birth to adulthood

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E

    1998-01-01

    Demineralized allogenic bone implanted in the subcutis or muscle of rodents causes formation of heterotopic bone by osteoinduction. The osteoinductive response may be weaker in primates than in rodents. It was suggested that the osteoinductive response of demineralized bone for clinical use could...... be enhanced by using young donors, because studies have indicated that the osteoinductive response is reduced in demineralized bone of old versus young donors. However, these findings may not represent a gradual decline in the osteoinductive property of bone matrix throughout the life span. We evaluated...... quantitatively, by uptake of strontium 85, the osteoinductive effect of demineralized bone matrix from newborn, 8-week-old (adolescent), and 8-month-old (adult) male Wistar rats implanted in the abdominal muscles of 8-week-old male Wistar rats. The osteoinductive response increased significantly with increasing...

  17. 'Adult T-cell leukemia/lymphoma' with bone demineralization

    International Nuclear Information System (INIS)

    Ohuchida, Toshiyuki; Nishitani, Hiromu; Matsuura, Keiichi

    1985-01-01

    Two patients with T-cell malignancy having radiographic manifestations of generalized and localized bone demineralization are reported. One, a 53-year-old-man, had marked osteoporosis and severe hypercalcemia, but no clinical evidence of leukemia throughout his illness. At autopsy there was no definite evidence of bone involvement. Histologic proof was obtained from abdominal skin which revealed ''adult T-cell leukemia/lymphoma (ATLL).'' The second case, a 33-year-old man, complained of arthralgia in his hands and feet; radiographs showed severe localized demineralization and pathologic fractures. Specimens of his peripheral blood, cervical lymph nodes, and bone marrow revealed ATLL cells. (orig.)

  18. Determination of bone demineralization in cats after experimental thyrotoxicosis

    Directory of Open Access Journals (Sweden)

    Fabiano Séllos Costa

    2006-10-01

    Full Text Available Hyperthyroidism can result in serious effects on the bone metabolism in humans as well as animals. For a better characterization of thyrotoxicosis effects, 16 cats were induced into thyrotoxicosis by intaking a dose of 150 µg/kg of sodium L-thyroxine every 24 hours during 42 days. The hormonal levels were evaluated by radioimmunoassay technique and the bone mineral density of the right distal radius extremity was measured through the radiographic optical densitometry. Was verified significant bone demineralization seven days of hormonal intake as weel as radius demineralization.

  19. Effect of glucose on fatigue-induced changes in the microstructure and mechanical properties of demineralized bovine cortical bone.

    Science.gov (United States)

    Trębacz, Hanna; Zdunek, Artur; Wlizło-Dyś, Ewa; Cybulska, Justyna; Pieczywek, Piotr

    2015-10-16

    The aim of this study was to test a hypothesis that fatigue-induced weakening of cortical bone was intensified in bone incubated in glucose and that this weakening is revealed in the microstructure and mechanical competence of the bone matrix. Cubic specimens of bovine femoral shaft were incubated in glucose solution (G) or in buffer (NG). One half of G samples and one half of NG were axially loaded in 300 cycles (30 mm/min) at constant deformation (F); the other half was a control (C). Samples from each group (GF, NGF, GC, NGC) were completely demineralized. Slices from demineralized samples were used for microscopic image analysis. A combined effect of glycation and fatigue on demineralized bone was tested in compression (10 mm/min). Damage of samples during the test was examined in terms of acoustic emission analysis (AE). During the fatigue procedure, resistance to loading in glycated samples decreased by 14.5% but only by 8.1% in nonglycated samples. In glycated samples fatigue resulted in increased porosity with pores significantly larger than in the other groups. Under compression, strain at failure in demineralized bone was significantly affected by glucose and fatigue. AE from demineralized bone matrix was considerably related to the largest pores in the tissue. The results confirm the hypothesis that the effect of fatigue on cortical bone tissue was intensified after incubation in glucose, both in the terms of the mechanical competence of bone tissue and the structural changes in the collagenous matrix of bone.

  20. Demineralization-remineralization dynamics in teeth and bone.

    Science.gov (United States)

    Abou Neel, Ensanya Ali; Aljabo, Anas; Strange, Adam; Ibrahim, Salwa; Coathup, Melanie; Young, Anne M; Bozec, Laurent; Mudera, Vivek

    Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization-remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties of the tooth and bone in addition to promoting more natural repair of surrounding tissues. Turning these new technologies to products and practices would improve health care worldwide.

  1. Ultrasonically-induced electrical potentials in demineralized bovine cortical bone

    Science.gov (United States)

    Mori, Shunki; Makino, Taiki; Koyama, Daisuke; Takayanagi, Shinji; Yanagitani, Takahiko; Matsukawa, Mami

    2018-04-01

    While the low-intensity pulsed ultrasound technique has proved useful for healing of bone fractures, the ultrasound healing mechanism is not yet understood. To understand the initial physical effects of the ultrasound irradiation process on bone, we have studied the anisotropic piezoelectric properties of bone in the MHz range. Bone is known to be composed of collagen and hydroxyapatite (HAp) and shows strong elastic anisotropy. In this study, the effects of HAp on the piezoelectricity were investigated experimentally. To remove the HAp crystallites from the bovine cortical bone, demineralization was performed using ethylene diamine tetra-acetic acid (EDTA) solutions. To investigate the piezoelectricity, we have fabricated ultrasound transducers using the cortical bone or demineralized cortical bone. The induced electrical potentials due to the piezoelectricity were observed as the output of these transducers under pulsed ultrasound irradiation in the MHz range. The cortical bone transducer (before mineralization) showed anisotropic piezoelectric behavior. When the ultrasound irradiation was applied normal to the transducer surface, the observed induced electrical potentials had minimum values. The potential increased under off-axis ultrasound irradiation with changes in polarization. In the demineralized bone transducer case, however, the anisotropic behavior was not observed in the induced electrical potentials. These results therefore indicate that the HAp crystallites affect the piezoelectric characteristics of bone.

  2. Comparison of ossification of demineralized bone, hydroxyapatite, Gelfoam, and bone wax in cranial defect repair.

    Science.gov (United States)

    Papay, F A; Morales, L; Ahmed, O F; Neth, D; Reger, S; Zins, J

    1996-09-01

    Demineralized bone allografts in the repair of calvarial defects are compared with other common bone fillers. This study uses a video-digitizing radiographic analysis of calvarial defect ossification to determine calcification of bone defects and its relation to postoperative clinical examination and regional controls. The postoperative clinical results at 3 months demonstrated that bony healing was greatest in bur holes filled with demineralized bone and hydroxyapatite. Radiographic analysis demonstrated calcification of demineralized bone-filled defects compared to bone wax- and Gelfoam-filled regions. Hydroxyapatite granules are radiographically dense, thus not allowing accurate measurement of true bone healing. The results suggest that demineralized bone and hydroxyapatite provide better structural support via bone healing to defined calvarial defects than do Gelfoam and bone wax.

  3. Advances in allogenic bone graft processing and usage: preparation and evaluation of chitosan-demineralized cancellous bone powder composite scaffolds as a bone graft substitute

    International Nuclear Information System (INIS)

    Yongyudh Vajaradul

    2008-01-01

    Full text: Demineralized bone matrix (DBM) is currently used by surgeons. It usually exists as a lyophilized powder which is difficult to handle and operated. In this study, we try to improve these disadvantages by combining DBM with a biomaterial. It focuses on a natural biodegradable polymer, chitosan, to act as a temporary matrix for bone growth that easily prepare in any size and shape by using tissue engineering knowledge to get a proper temporary matrix. Thus, the development of chitosan-demineralized bone powder composite scaffold is an alternative way. Polymeric scaffold has been demonstrated to have great potential for tissue engineering because the scaffold or three dimension (3D) construct provides the necessary support for cells to proliferate, extracellular matrix deposition and vascularization of neo-tissue. Moreover, chitosan, a natural cationic polymer which its structural is similar to extracellular matrix glycosaminoblycans, is biodegradable, biocompatible, non-antigenic and biofunctional. It can enhance osteoblast cells proliferation and mineral matrix deposition in culture. The first study was to fabricate and analyze composite scaffold composed of either chitosan-demineralized cancellous bone powders or chitosan-demineralized cancellous cartilage bone powders in a ratio 50:50 and 70:30 w/w (chitosan : bone powders) based on physical properties composing of average pore diameter, mechanical integrity and swelling property. Secondly, scaffolds were evaluated in term of biological properties composing of their ability to support neo osteogenesis, including assessments of cell attachment and viability, cell morphology, and the biosynthesis of extracellular matrix. Results indicated that chitosan-demineralized cancellous bone powder composite scaffolds possessing an interconnecting, porous structure could be easily created through a simple freezing and lyophilization process. (Author)

  4. Anisotropy in Bone Demineralization Revealed by Polarized Far-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Roman Schuetz

    2015-04-01

    Full Text Available Bone material is composed of an organic matrix of collagen fibers and apatite nanoparticles. Previously, vibrational spectroscopy techniques such as infrared (IR and Raman spectroscopy have proved to be particularly useful for characterizing the two constituent organic and inorganic phases of bone. In this work, we tested the potential use of high intensity synchrotron-based far-IR radiation (50–500 cm−1 to gain new insights into structure and chemical composition of bovine fibrolamellar bone. The results from our study can be summarized in the following four points: (I compared to far-IR spectra obtained from synthetic hydroxyapatite powder, those from fibrolamellar bone showed similar peak positions, but very different peak widths; (II during stepwise demineralization of the bone samples, there was no significant change neither to far-IR peak width nor position, demonstrating that mineral dissolution occurred in a uniform manner; (III application of external loading on fully demineralized bone had no significant effect on the obtained spectra, while dehydration of samples resulted in clear differences. (IV using linear dichroism, we showed that the anisotropic structure of fibrolamellar bone is also reflected in anisotropic far-IR absorbance properties of both the organic and inorganic phases. Far-IR spectroscopy thus provides a novel way to functionally characterize bone structure and chemistry, and with further technological improvements, has the potential to become a useful clinical diagnostic tool to better assess quality of collagen-based tissues.

  5. Ethylene oxide gas sterilization does not reduce the osteoinductive potential of demineralized bone in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G

    1995-01-01

    It has been shown that different sterilization procedures of demineralized bone may influence its osteoinductive properties. The aim of this study was to evaluate the effect of ethylene oxide sterilization for 1, 3, and 6 hours on the osteoinductive potential of allogeneic demineralized bone...... implanted heterotopically in rats. Sixty male Wistar rats were randomly assigned to one of four groups, A through D, and four demineralized bone chips (2.8 mg) were implanted in a pouch created between the right oblique abdominal muscles in each animal. In Group A, the demineralized bone was implanted...... without prior sterilization of the material, whereas the demineralized bone implanted in Groups B, C, and D had been sterilized in ethylene oxide gas for 1, 3, or 6 hours, respectively, and aerated for 48 hours. At 4 weeks postoperatively, bone formation was evaluated quantitatively by strontium 85 uptake...

  6. Regeneration of calvarial defects by a composite of bioerodible polyorthoester and demineralized bone in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G

    1992-01-01

    A study was performed to evaluate regeneration of defects in rat calvaria either unfilled or filled with a bioerodible polyorthoester only, demineralized bone only, or a composite of both. At 4 weeks, histological and radiographic studies showed that defects filled with a composite of bioerodible...... polyorthoester and demineralized bone or demineralized bone alone were bridged by bone. Unfilled defects or defects filled with polyorthoester only did not heal. The polyorthoester caused slight inflammation that subsided by 3 weeks, and only traces of the filler could be detected at 4 weeks. The polyorthoester...... provided local hemostasis when used either alone or in composites with demineralized bone. The composite implant was moldable, easily contoured, and technically easier to use than demineralized bone alone....

  7. Effect of ethylene oxide sterilization on the osteoinductivity of demineralized allograft bone powder

    International Nuclear Information System (INIS)

    Hamid Reza Aghayan; Babak Arjmand; Mehdi Golestani; Farokh Tirgari

    2008-01-01

    Full text: Ethylene oxide has been widely used for secondary sterilization of bone allograft to reduce the risk of infection and associated complications. In this study we investigate the effects of ethylene oxide gas sterilization on the osteoinductivity of demineralized bone Powder. Eighteen rats received two separate implants consisting of 30 mg aseptically prepared and 30 mg ethylene oxide-sterilized demineralized bone powder. The demineralized bone powder from each group was placed into two separate muscle pouch created in the paravertebral muscles of each rat. After 4 weeks each implantation site was removed with 0.5 cm normal tissue around the implant. Histological examination was done to determine the presence or absence of osteoinduction. All except one of eighteen aseptically prepared demineralized bone powder sites histologically contained new bone elements (94.4%) and fourteen (77.7%) of ethylene oxide sterilized demineralized bone powder sites showed evidence of new bone elements (p>0.05). There is no significant difference in osteoblast formation in two groups. We concluded that ethylene oxide sterilization in 42 degree C did not significantly reduce the osteoinductivity of demineralized bone powder. So ethylene oxide can be considered as a suitable but not perfect method for secondary sterilization of demineralized bone powder. (Author)

  8. ALVEOLAR BONE REGENERATION AFTER DEMINERALIZED FREEZE DRIED BONE ALOGRAFT (DFDBA BONE GRAFTING

    Directory of Open Access Journals (Sweden)

    Sri Oktawati

    2006-04-01

    Full Text Available Periodontal treatment by conventional way will result in healing repair, which easily cause recurrence. Modification of treatment should be done to get an effective result, that is the regeneration of alveolar bone and to reduce inflammation. The objective of this study is to determine the alveolar bone regeneration after using DFDBA (Demineralized Freeze Dried Bone Allograft. Quasi experimental designs with pre and post test method was used in this study. From 13 patients, 26 defects got conventional or regenerative treatment. The indicator of alveolar bone regenaration in bone height in radiographic appearance and level of osteocalsin in gingival crevicular fluid (GCF were checked before and after the treatment, then the changes that occurred were analyzed. The result of the research showed that alveolar bone regeneration only occurred to the group of regenerative treatment using DFDBA. The conclusion is the effective periodontal tissue regeneration occurred at regenerative treatment by using DFDBA, and the osteocalsin in GCF can be used as indicator of bone growth.

  9. Effect of gamma irradiation sterilization on the osteoinductive capacity of demineralized bone powder

    International Nuclear Information System (INIS)

    Babak Arjmand; Hamid Reza Aghayan; Mehdi Golestani; Farid Azmoudeh Ardalan

    2008-01-01

    Full text: Gamma irradiation is a well known method for secondary sterilization of bone allograft before clinical use to reduce the risk of infections and complications. The current study evaluated the effect of gamma irradiation on the osteoinductive capability of human demineralized bone powder using a rat model. Twenty rats received two separate implants consisting of 30 mg aseptically-harvested and 30 mg gamma irradiated demineralized bone powder. The implants from each group were placed into two separate muscle pouch in the paravertebral muscles of each rat. All 20 rats were euthanized after 4 weeks and each implantation site was removed with 0.5 cm normal tissue around the implant. Histological examination was done to determine the presence or absence of new bone, cartilage and bone marrow element. All except one of 20 aseptically-harvested demineralized bone powder sites histologically contained new bone elements (95%) and six (30%) of 20 gamma irradiated demineralized bone powder sites showed evidence of new bone elements. There was significant difference between two groups (p<0.05). The results of this study indicate that gamma irradiation reduces osteoinductive properties of demineralized bone powder. But because of its availability and low cost it is widely used for secondary sterilization of bone allografts. (Author)

  10. Bone induction by composite of bioerodible polyorthoester and deminiralized bone matrix in rats

    International Nuclear Information System (INIS)

    Pinholt, E.M.; Solheim, E.; Bang, G.; Sudmann, E.

    1991-01-01

    A composite of a local, sustained, drug-release system, Alzamer bioerodible polyorthoester, and demineralized bone-matrix (DBM) particles implanted in the abdominal muscle of 89 Wistar rats induced cartilage and bone formation at the same rate as DBM when evaluated histologically and by 85 Sr uptake. The composite implant was technically easier to use than DBM alone. (author)

  11. Avaliação das metaloproteinases de matriz -2 e -9 em gatos com desmineralização óssea secundária à tirotoxicose induzida Evaluation of matrix metalloproteinases -2 and -9 in cats under bone demineralization secondary to induced thyrotoxicosis

    Directory of Open Access Journals (Sweden)

    F.S. Costa

    2008-10-01

    Full Text Available Observou-se significativo aumento de atividade das formas ativas das metaloproteinases -2 e -9 em gatos com tirotoxicose induzida e desmineralização óssea. As formas pró e intermediária da metaloproteinase -2 elevaram-se com 14 dias de administração hormonal, porém, posteriormente, houve uma tendência de queda. Observou-se correlação negativa entre a forma ativa das metaloproteinases de matriz -2 e -9 e a densidade mineral óssea da extremidade distal do rádio. Os resultados sugerem aumento da degradação da matriz colágena secundária com a elevação dos hormônios tiroidianos.Significant increase of activity of active forms of matrix metalloproteinases -2 and -9 in cats under induced thyrotoxicosis and bone demineralization was observed. Pro and intermediated forms of matrix metalloproteinases -2 and -9 increased at 14 days of hormonal treatment, followed by decrease tendency. A negative correlation between active forms of matrix metalloproteinases -2 and -9 and bone mineral density of radius distal extremity was also observed. The results suggest an increase of collagen matrix degradation secondary to high levels of thyroid hormones.

  12. Effect of storage on osteoinductive properties of demineralized bone in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E

    1994-01-01

    A requirement for the clinical use of demineralized bone is the possibility of storing the material without loss of its osteoinductive properties. Seventy-five 8-week-old male Wistar rats were randomly assigned to one of five groups of 15 rats each. Lyophilized demineralized allogeneic bone...... was prepared and implanted in the abdominal muscle either without prior storage (control group) or after storage for 9 or 14 months at -70 degrees C or 4 degrees C (four experimental groups). Bone formation in the implants was evaluated quantitatively 4 weeks postoperatively by measuring the strontium 85...

  13. Demineralized Freeze-Dried Bovine Cortical Bone: Its Potential for Guided Bone Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2017-01-01

    Full Text Available Background. Bovine pericardium collagen membrane (BPCM had been widely used in guided bone regeneration (GBR whose manufacturing process usually required chemical cross-linking to prolong its biodegradation. However, cross-linking of collagen fibrils was associated with poorer tissue integration and delayed vascular invasion. Objective. This study evaluated the potential of bovine cortical bone collagen membrane for GBR by evaluating its antigenicity potential, cytotoxicity, immune and tissue response, and biodegradation behaviors. Material and Methods. Antigenicity potential of demineralized freeze-dried bovine cortical bone membrane (DFDBCBM was done with histology-based anticellularity evaluation, while cytotoxicity was analyzed using MTT Assay. Evaluation of immune response, tissue response, and biodegradation was done by randomly implanting DFDBCBM and BPCM in rat’s subcutaneous dorsum. Samples were collected at 2, 5, and 7 days and 7, 14, 21, and 28 days for biocompatibility and tissue response-biodegradation study, respectively. Result. DFDBCBM, histologically, showed no retained cells; however, it showed some level of in vitro cytotoxicity. In vivo study exhibited increased immune response to DFDBCBM in early healing phase; however, normal tissue response and degradation rate were observed up to 4 weeks after DFDBCBM implantation. Conclusion. Demineralized freeze-dried bovine cortical bone membrane showed potential for clinical application; however, it needs to be optimized in its biocompatibility to fulfill all requirements for GBR membrane.

  14. Evaluation of demineralized bone and bone transplants in vitro and in vivo with cone beam computed tomography imaging.

    Science.gov (United States)

    Draenert, F G; Gebhart, F; Berthold, M; Gosau, M; Wagner, W

    2010-07-01

    The objective of this study was to determine the ability of two flat panel cone beam CT (CBCT) devices to identify demineralized bone and bone transplants in vivo and in vitro. Datasets from patients with autologous bone grafts (n = 9, KaVo 3DeXam (KaVo, Biberach, Germany); n = 38, Accuitomo 40 (Morita, Osaka, Japan)) were retrospectively evaluated. Demineralized and non-demineralized porcine cancellous bone blocks were examined with the two CBCT devices. A SawBone skull (Pacific Research Laboratories, Vashon, WA) was used as a positioning tool for the bone blocks. Descriptive evaluation and image quality assessment were conducted on the KaVo 3DeXam data (voxel size 0.3 mm) using the OsiriX viewer as well as on the Morita Accuitomo data (voxel size 0.25 mm) using proprietary viewer software. Both in vivo and in vitro, the descriptive analysis of the images of the two devices showed well-visualized bone transplants with clearly defined cancellous bones and well-defined single bone trabeculae in all cross-sections. In vitro, demineralized samples showed lower radiographic opacity but no significant loss of quality compared with fresh bone (P = 0.070). Single cancellous bone trabeculae were significantly better visualized with the Morita 3D Accuitomo device than with the KaVo 3DeXam device (P = 0.038). Both the KaVo 3DeXam and Morita 3D Accuitomo devices produce good-quality images of cancellous bones in in vivo remodelling as well as after in vitro demineralization.

  15. Pathologic fracture through a unicameral bone cyst of the pelvis: CT-guided percutaneous curettage, biopsy, and bone matrix injection.

    Science.gov (United States)

    Tynan, Jennifer R; Schachar, Norman S; Marshall, Geoffrey B; Gray, Robin R

    2005-02-01

    Unicameral bone cysts of the pelvis are extremely rare. A 19-year old man presented with a pathologic fracture through a pelvic unicameral bone cyst. He was treated with computed tomography-guided percutaneous curettage, biopsy, and demineralized bone matrix injection. Treatment has proven successful in short-term follow-up.

  16. Computational segmentation of collagen fibers in bone matrix indicates bone quality in ovariectomized rat spine.

    Science.gov (United States)

    Daghma, Diaa Eldin S; Malhan, Deeksha; Simon, Paul; Stötzel, Sabine; Kern, Stefanie; Hassan, Fathi; Lips, Katrin Susanne; Heiss, Christian; El Khassawna, Thaqif

    2018-05-01

    Bone loss varies according to disease and age and these variations affect bone cells and extracellular matrix. Osteoporosis rat models are widely investigated to assess mechanical and structural properties of bone; however, bone matrix proteins and their discrepant regulation of diseased and aged bone are often overlooked. The current study considered the spine matrix properties of ovariectomized rats (OVX) against control rats (Sham) at 16 months of age. Diseased bone showed less compact structure with inhomogeneous distribution of type 1 collagen (Col1) and changes in osteocyte morphology. Intriguingly, demineralization patches were noticed in the vicinity of blood vessels in the OVX spine. The organic matrix structure was investigated using computational segmentation of collagen fibril properties. In contrast to the aged bone, diseased bone showed longer fibrils and smaller orientation angles. The study shows the potential of quantifying transmission electron microscopy images to predict the mechanical properties of bone tissue.

  17. Effects of solvents on the early stage stiffening rate of demineralized dentin matrix.

    Science.gov (United States)

    Garcia, Fernanda C P; Otsuki, Masayuki; Pashley, David H; Tay, Franklin R; Carvalho, Ricardo M

    2005-05-01

    To monitor the stiffening rate of demineralized dentin matrix at the early stages after exposure to different neat solvents. Dentin beams approximately 0.8x0.7x8.0 mm were obtained from human third molars. After covering their ends with resin composite, the middle exposed length of 4.0mm (gauge-length) was demineralized in 0.5 M EDTA (pH 7.0) for 7 days. The specimens were gripped by a testing machine, pre-loaded to 10 g and cyclically stressed in tension to 5% strain, for 30 repeated cycles (total 20 min) at 0.6 mm/min while immersed in water (control). Then, water was replaced by either 100% acetone, methanol, ethanol, propanol, HEMA or air and the specimens subjected to the same cyclic protocol. The maximum apparent modulus of elasticity (E(Max)) was calculated for every cycle, plotted as a function of time and subjected to regression analysis. Stiffening rate was calculated as changes in E (min). Regression analysis examined the relationship between E and time for each solvent. Data were analyzed by one-way ANOVA and Student-Newman-Keuls test at alpha=0.05. Regression analysis showed that E increased significantly with time in all water-free solvents (R2=0.8-0.99). Stiffening rate was higher for acetone (0.9 MPa/min) and ethanol (0.8 MPa/min), intermediate for air (0.7 MPa/min), methanol (0.6 MPa/min) and propanol (0.5 MPa/min), lower for HEMA (0.2 MPa/min) and practically none for water (0.07 MPa/min) with prate of demineralized dentin matrix is both time and solvent-dependent. The ability of solvents to promptly stiffen the demineralized dentin matrix may be important in maintaining the resin-infiltrated matrix expanded during the solvent evaporation stage of resin bonding.

  18. Effects of ionizing radiation on proteins in demineralized, lyophilized or frozen human bone

    Energy Technology Data Exchange (ETDEWEB)

    Antebi, Uri; Mathor, Monica B., E-mail: uri@usp.br, E-mail: mathor@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Guimaraes, Rodrigo P., E-mail: clinicaguimaraes@gmail.com [Santa Casa de Sao Paulo (FCM/SCSP), Sao Paulo, SP (Brazil). Faculdade de Ciencias Medicas

    2015-07-01

    The aim is the study of the application of ionizing radiation (gamma and electron) as sterilizing agents at doses of 15 kGy, 25 kGy and 50 kGy, the demineralized bone tissue frozen and freeze-dried for use in transplants. Five human femoral diaphysis of different donors demineralized bone tissues were preserved as lyophilized or frozen at - 80 deg C. The samples were divided into non-irradiated groups (control) and irradiated by gamma rays or electron beam. The bone proteins were extracted and used to determine the concentrations of total protein, BMP 2 and 7. It was observed a decrease in total protein concentrations, and BMP 2 and 7. The decrease in total protein concentrations, as compared to respective control groups was significant in the lyophilized and frozen samples irradiated at a dose of 50 kGy gamma radiation and beam electrons with greater than 30% reduction. The significant decrease in the levels of BMP 2 and 7 were also observed in higher doses and especially by electron beam. The reductions in the concentrations of total protein and osteoinductive proteins (BMP 2 and 7), were related to the radiation dose, i.e., increase with higher doses of ionizing radiation type and the type of preservation of the bones. The largest reductions in concentrations were observed in bone irradiated by electron beam and at a dose of 50 kGy. But this type of radiation and this high dose are not usual practice for the sterilization of bone tissue. Keywords: demineralized bone tissue, ionizing radiation, Tissue Bank, BMP 2, BMP 7, bone proteins. (author)

  19. Effects of ionizing radiation on proteins in demineralized, lyophilized or frozen human bone

    International Nuclear Information System (INIS)

    Antebi, Uri; Mathor, Monica B.; Guimaraes, Rodrigo P.

    2015-01-01

    The aim is the study of the application of ionizing radiation (gamma and electron) as sterilizing agents at doses of 15 kGy, 25 kGy and 50 kGy, the demineralized bone tissue frozen and freeze-dried for use in transplants. Five human femoral diaphysis of different donors demineralized bone tissues were preserved as lyophilized or frozen at - 80 deg C. The samples were divided into non-irradiated groups (control) and irradiated by gamma rays or electron beam. The bone proteins were extracted and used to determine the concentrations of total protein, BMP 2 and 7. It was observed a decrease in total protein concentrations, and BMP 2 and 7. The decrease in total protein concentrations, as compared to respective control groups was significant in the lyophilized and frozen samples irradiated at a dose of 50 kGy gamma radiation and beam electrons with greater than 30% reduction. The significant decrease in the levels of BMP 2 and 7 were also observed in higher doses and especially by electron beam. The reductions in the concentrations of total protein and osteoinductive proteins (BMP 2 and 7), were related to the radiation dose, i.e., increase with higher doses of ionizing radiation type and the type of preservation of the bones. The largest reductions in concentrations were observed in bone irradiated by electron beam and at a dose of 50 kGy. But this type of radiation and this high dose are not usual practice for the sterilization of bone tissue. Keywords: demineralized bone tissue, ionizing radiation, Tissue Bank, BMP 2, BMP 7, bone proteins. (author)

  20. Usage of demineralized bone powder in dental implant surgery

    International Nuclear Information System (INIS)

    Chang Joon Yim

    1999-01-01

    While there is much concern in the dental community about the risk of disease transfer with processed bone a] iografts, there has never been a case of disease transfer with DFDB. Exclusionary techniques and chemical processing of the allogeneic bone has rendered these grafts safe for human implantation. The literature indicates that there has been considerable interest in the biology and applied science of osteoinduction. The accumulated evidence supports the concept of cartilage and bone cell differentiation induced by a unique bone motphogenetic protein (BMP). Currently clinical usage has been focused on the alveolar bone defects associated with the dental implant surgery, which has become one of the most important areas in dental outpatient clinic. Increased application of the endosseous dental implant system results in a lot of demands to regenerate the alveolar bone defects around the dental implants. Anderegg et al.(1991) reported the excellent results from the combination of DFDB powder and expanded PTFE (polytetrafluorethylene) membranes. Since 1980 the author experienced the human DFDB powders for the oral and maxillofacial surgery and the dental implant surgery. Yim and Kim(1993) evaluated 93 surgical sites where DFDB was used and found 96.7% of success rates at re-entry surgery. Mellonig and Triplett (1993) reported 97% of success rates, and Gelb (1993) obtained 98% of success rates. Fugazzotto (1994) placed 59 dental implants at the time of sinus lifts with the composite graft of DFDB and resorbable tricalcium phosphate and none of implants was lost on uncovering and only one was lost while functioning. Yim (1994) placed 44 dental implants at the time of sinus lifts with DFDB, and none of implants was lost on uncovering. Zinner and Small (1996) placed 215 dental implants at the time of sinus lifts (52 sinuses) with the composite graft of DFDB, and other materials, 3 implants of which were failed on uncovering. To date, maxillary sinus lift graft with

  1. The relation between bone demineralization, physical activity and anthropometric standards

    Directory of Open Access Journals (Sweden)

    Milena Barbosa Camara

    2017-03-01

    Full Text Available This paper aimed to verify the correlation between bone mineral density and the level of physical activity, as well as the food intake and the anthropometric parameters. It intended to analyse the bone mineral density (BMD of menopausal women through the bone densitometry test (DO in the lumbar region (L1 to L4, femoral neck and total femur, and also use Bouchard’s self-recall of daily activities; employing the food record from Buker and Stuart to dose and quantify the daily intake of calcium and vitamin D. The data were analysed via Kolmogorov-Smirnov’s test, and default value of α = 0.05 was set to compare the BMD averages. It was observed that one hundred percent of the assessed individuals had a BMD level below the average fixed by WHO: 14.4% with osteopenia and 85.6% with osteoporosis; a lower BMD in the femoral area (0.721g and the biggest loss among the sedentary ones (0.698g. It was noticed that there was a correlation between the physical activities and the BMD only when associated with anthropometric standards and the daily ingestion of vitamin D.

  2. Heterotopic new bone formation causes resorption of the inductive bone matrix

    International Nuclear Information System (INIS)

    Nilsson, O.S.; Persson, P.E.; Ekelund, A.

    1990-01-01

    The bone matrix of growing rats was labeled by multiple injections of 3H-proline, and demineralized bone matrix (DBM) was prepared. The DBM was allotransplanted heterotopically into growing rats. New bone formation was induced in and around the implants. The new bone formation was accompanied by a decrease in the content of 3H; 20 and 30 days after implantation, 72% and 46%, respectively, of the activity remained in the implants. Daily injections of indomethacin (2 mg/kg) inhibited calcium uptake by about 20% at 20 and 30 days and inhibited the release of 3H from the DBM to a similar degree. Heterotopic bone induction by DBM is accompanied by matrix resorption, and inhibition of the new bone formation decreases the resorption of DBM

  3. Net expansion of dried demineralized dentin matrix produced by monomer/alcohol saturation and solvent evaporation.

    Science.gov (United States)

    Agee, Kelli A; Becker, Thomas D; Joyce, Anthony P; Rueggeberg, Frederick A; Borke, James L; Waller, Jennifer L; Tay, Franklin R; Pashley, David H

    2006-11-01

    The purpose of this work was to determine if nonaqueous methacrylate monomer/alcohol mixtures could expand dried collapsed demineralized dentin matrix. Thin disks (ca. 200 microm) of human dentin were demineralized and placed in wells beneath contact probes of linear variable differential transformers. The probes were placed on water-saturated expanded matrices to record the shrinkage associated with drying. Monomer mixtures containing hydroxyethyl methacrylate, 2,2-bis[4-(2-hydroxy-3 methacryloyloxy)propoxyphenyl] propane, or triethyleneglycol dimethacrylate were mixed with methanol or ethanol at alcohol/monomer mass fraction % of 90/10, 70/30, 50/50, or 30/70. They were randomly applied to the dried matrices to determine the rate and magnitude of expansion; then shrinkage was recorded during evaporation of the alcohols. The results indicated that matrix expansion was positively correlated with the Hoy's solubility parameters for hydrogen bonding forces (delta(h)) of the monomer/solvent mixtures (p methanol-containing than with ethanol-containing monomer mixtures. For the test solutions, triethyleneglycol dimethacrylate-containing mixtures produced the slowest rate of matrix expansion and hydroxyethyl methacrylate-containing mixtures the most rapid expansion. When the solvents were evaporated, the matrix shrank in proportion to the solvent content and the delta(h) of the monomer-solvent mixtures. The results indicate that expansion of dried, collapsed dentin matrices requires that the delta(h) of the mixtures be larger than 17 (J/cm(3))(1/2). The greater the delta(h) of the monomer solutions, the greater the rate and extent of expansion.

  4. EXPERIMENTAL ESTIMATION OF THE DEMINERALIZED BONE ALLOGRAFTS MADE BY TECHNOLOGY OF CITO

    Directory of Open Access Journals (Sweden)

    Yu. B. Yurasova

    2010-01-01

    Full Text Available Research is devoted an experimental estimation of osteoinductive properties of demineralized bone implants (DBA made on technology CITO with use of lyophilization and radiating sterilization by stream of fast electrons. As experimental animals, white rats on ectopic osteogenesis model for a period of 40 days and rabbits to which DBA implanted into defect of the jaw with terms of experiment 10, 20, 30, 60 and 90 days have been chosen. Results of morphological researches testified to absence of toxicity, presence of high indicators of biointegration and osteoinductance studied DBA. The offered technology of processing of a bone tissue allows to keep biological activity of tissues and to receive biological materials with the expressed plastic properties. Obtained among other data were the bases for the decision of use of these materials in clinic of different bone pathologies.

  5. Microscopic and radiographic analysis of the effect of particle size of demineralized bovine cancellous bone matrix on the repair of bone defects in femurs of rabbits Análise microscópica e radiográfica do efeito do tamanho das partículas de matriz de osso medular bovino desmineralizado na reparação de defeito ósseo em fêmures de coelhos

    Directory of Open Access Journals (Sweden)

    Everdan Carneiro

    2005-06-01

    Full Text Available The bone tissue has a great regenerative potential, with ability to completely restore its structure and original functions. In some situations, though, bone defects cannot be self-repaired, thus requiring the use of grafts for a correct treatment and good prognosis. This work aimed at microscopically analyzing the effect of the particle size of demineralized bovine cancellous bone matrix in micro and macrogranular forms on the repair of bone defects in femurs of rabbits, with blood clot used as control. At 1, 3 and 6 months after implantation of the materials, the animals were killed and the anatomic specimens were removed. A foreign body-type granulomatous reaction containing macrophages and multinucleated giant cells in contact with the implanted particles was observed. These results suggest a failure in demineralization and/or interruption of the antigenic potential during production of the biomaterial. It is concluded that the size of the particles did not influence the evolution of the repair process of bone defects, acting only as bone-filler substances, and that the material implanted should be improved by quality control during production, since it may represent a good alternative for bone graft.O tecido ósseo possui grande potencial regenerativo com capacidade para restaurar completamente sua estrutura e função originais. Há situações em que os defeitos ósseos não conseguem por si só obter o reparo, casos em que se fazem necessários o uso de enxertos, para um correto tratamento e bom prognóstico. Este experimento teve o propósito de analisar microscopicamente o efeito do tamanho das partículas de matriz de osso medular bovino desmineralizado, nas formas micro e macrogranular, na reparação de defeito ósseo em fêmures de coelhos, tendo como controle o coágulo sanguíneo. Após 1,3 e 6 meses da implantação dos materiais, os animais foram mortos e as peças anatômicas removidas. Uma reação granulomatosa tipo corpo

  6. Genetical stability and osteogenic ability of mesenchimal stem cells on demineralized bone matrices

    Directory of Open Access Journals (Sweden)

    A. Pozzuoli

    2015-03-01

    Full Text Available Aim Tissue engineering is a rapidly expanding field with regard to the use of biomaterials and stem cells in the orthopedic surgery. Many experimental studies have been done to understand the best characteristics of cells, materials and laboratory methods for safe clinical applications. The aim of this study was to compare the ability of 2 different human demineralized bone matrices (DBMs, the one enriched and the other not enriched with hyaluronic acid, to stimulate in vitro the proliferation and the osteogenic differentiation of human adipose-derived stem cells (ADSCs seeded onto an osteoconductive scaffold. Materials and Methods ADSCs were isolated, by enzymatic digestion, from abdominal adipose tissue of 5 patients undergoing cosmetic lipoaspiration surgery. ADSCs were then seeded onto a 3D scaffold in the presence of the two different osteoinductive matrices of human demineralized bone and evaluated for proliferation and osteogenic differentiation. The safety of the methods was verified using array-Comparative Genomic Hybridization (array-CGH. Results ADSCs were able to differentiate in osteogenic sense. Both DBMs showed the ability to induce osteogenic differentiation of the cells. Conclusion array-CGH showed no changes at genome level, thus confirming the safety of materials and methods.

  7. Effects of fatigue on microstructure and mechanical properties of bone organic matrix under compression

    International Nuclear Information System (INIS)

    Trębacz, Hanna; Zdunek, Artur; Cybulska, Justyna; Pieczywek, Piotr

    2013-01-01

    The aim of the study was to investigate whether a fatigue induced weakening of cortical bone was revealed in microstructure and mechanical competence of demineralized bone matrix. Two types of cortical bone samples (plexiform and Haversian) were use. Bone slabs from the midshaft of bovine femora were subjected to cyclical bending. Fatigued and adjacent control samples were cut into cubes and demineralized in ethylenediaminetetraacetic acid. Demineralized samples were either subjected to microscopic quantitative image analysis, or compressed to failure (in longitudinal or transverse direction) with a simultaneous analysis of acoustic emission (AE). In fatigued samples porosity of organic matrix and average area of pores have risen, along with a change in the pores shape. The effect of fatigue depended on the type of the bone, being more pronounced in the plexiform than in Haversian tissue. Demineralized bone matrix was anisotropic under compressive loads in both types of cortical structure. The main result of fatigue pretreatment on mechanical parameters was a significant decrease of ultimate strain in the transverse direction in plexiform samples. The decrease of strain in this group was accompanied by a considerable increase of the fraction of large pores and a significant change in AE energy.

  8. Endochondral vs. intramembranous demineralized bone matrices as implants for osseous defects.

    Science.gov (United States)

    Nidoli, M C; Nielsen, F F; Melsen, B

    1999-05-01

    This study focuses on the difference in regenerative capacity between endochondral and intramembranous demineralized bone matrices (DBMs) when implanted into bony defects. It also focuses on the possible influence of the type of skeletal recipient site (orthotopic or heterotopic). Of 34 Wistar rats, 10 served as a source of DBM, and 24 were divided into two groups of 12 animals. In group A identical defects were produced in the parietal bones, whereas in group B the defects were produced in each radius. The right defects were implanted with endochondral DBM and the left defects were implanted with intramembranous DBM. Descriptive and/or histomorphometric analyses were performed by means of light and polarized microscopy, and radiography (group B). Right and left data were compared to disclose differences in bone-healing capacity. The quantitative results demonstrated that endochondral DBM displays a greater regenerative capacity than intramembranous DBM when implanted heterotopically. The different clinical performances of endochondral and intramembranous bone grafts might be explained on the basis of the mechanical rather than the osteoinductive principle. The qualitative results suggest that the type of bone deposition induced by the DBMs is not related to the type of implanted DBM. Recipient site characteristics and/or environmental factors seem decisive in the occurrence of either types of ossification.

  9. Angiographic findings of demineralised bone matrix grafts in femoral fracture repair in canines*

    International Nuclear Information System (INIS)

    Kumar, R.V.S.; Ramakrishna, O.

    2000-01-01

    Demineralised bone matrix implants and autogenous cancellous bone grafts were evaluated in femoral fracture repair with bone loss in canines, and compared to untreated animals. Angiograms were taken at 3,6,9 and 12 weeks post- operatively using conrary-420 as contrast medium. Early angiograms showed leakage of contrast medium into soft tissue. Grafted groups showed slight hypervascularity and enhanced capillary network. At 12 Weeks the same groups observed nearly normal persistent vascular supply. Early establishment of cortices continuity and draining of contrast medium via extraosseous veins was observed in demineralized bone matrix implanted groups

  10. The effect of a composite of polyorthoester and demineralized bone on the healing of large segmental defects of the radius in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Andersen, R

    1992-01-01

    The effect of a composite of demineralized bone mixed with polyorthoester on the healing of large segmental defects in the rat radius was studied. Sixty male Wistar rats were divided into four groups, A through D, and an osteoperiosteal diaphyseal defect of 50 per cent of the length of the bone....... The formation of bone in the defects was quantified with computer-assisted measurements of the area on radiographs. The host-tissue response was evaluated with light microscopy. Defects that had been filled with the composite of polyorthoester and demineralized bone or with demineralized bone alone showed...... regeneration of bone corresponding to 93.6 and 77.6 per cent of the area of the defect, respectively. Defects that had no implant or that had been filled with polyorthoester alone showed significantly less formation of bone. No inflammation was seen with light microscopy, and only traces of the polyorthoester...

  11. Development of Collagen/Demineralized Bone Powder Scaffolds and Periosteum-Derived Cells for Bone Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Wilairat Leeanansaksiri

    2013-01-01

    Full Text Available The aim of this study was to investigate physical and biological properties of collagen (COL and demineralized bone powder (DBP scaffolds for bone tissue engineering. DBP was prepared and divided into three groups, based on various particle sizes: 75–125 µm, 125–250 µm, and 250–500 µm. DBP was homogeneously mixed with type I collagen and three-dimensional scaffolds were constructed, applying chemical crosslinking and lyophilization. Upon culture with human periosteum-derived cells (PD cells, osteogenic differentiation of PD cells was investigated using alkaline phosphatase (ALP activity and calcium assay kits. The physical properties of the COL/DBP scaffolds were obviously different from COL scaffolds, irrespective of the size of DBP. In addition, PD cells cultured with COL scaffolds showed significantly higher cell adhesion and proliferation than those with COL/DBP scaffolds. In contrast, COL/DBP scaffolds exhibited greater osteoinductive potential than COL scaffolds. The PD cells with COL/DBP scaffolds possessed higher ALP activity than those with COL scaffolds. PD cells cultured with COL/DBP scaffolds with 250–500 mm particle size yielded the maximum calcium deposition. In conclusion, PD cells cultured on the scaffolds could exhibit osteoinductive potential. The composite scaffold of COL/DBP with 250–500 mm particle size could be considered a potential bone tissue engineering implant.

  12. Methods for demonstration of enzyme activity in muscle fibres at the muscle/bone interface in demineralized tissue

    DEFF Research Database (Denmark)

    Kirkeby, S; Vilmann, H

    1981-01-01

    A method for demonstration of activity for ATPase and various oxidative enzymes (succinic dehydrogenase, alpha-glycerophosphate dehydrogenase, and lactic dehydrogenase) in muscle/bone sections of fixed and demineralized tissue has been developed. It was found that it is possible to preserve...... considerable amounts of the above mentioned enzymes in the muscle fibres at the muscle/bone interfaces. The best results were obtained after 20 min fixation, and 2-3 weeks of storage in MgNa2EDTA containing media. As the same technique previously has been used to describe patterns of resorption and deposition...

  13. TOTAL HIP ARTHROPLASTY IN CHILDREN WHO HAVE UNDERGONE ARTHROPLASTY WITH DEMINERALIZED BONE-CARTILAGE ALLOCUPS

    Directory of Open Access Journals (Sweden)

    Vladimir E. Baskov

    2017-03-01

    Full Text Available Introduction. Treating children with degenerative dystrophic diseases of the hip joint has become one of the most acute problems in contemporary orthopedics. Until recently, we performed arthroplasty by demineralized bone-cartilage allocups (DBCA in the Clinic of the Hip Joint Pathology of the Turner Scientific and Research Institute for Children’s Orthopedics for patients showing clinical and radiological signs of irreversible destruction of the hip joint; we carried out this procedure to preserve the function of the lower limb. However, over the last 8 years, we have changed our protocol for children older than 12 years of age and have replaced DBCA with total hip replacement. In a number of cases, total hip replacement was performed after a previous intervention involving arthroplasty with DBCA. Objective. To determine the technical peculiarities of total hip replacement after a previous intervention involving arthroplasty with DBCA. Material and methods. We analyzed the results of treatment involving various types of hip pathology in 13 children (100% aged between 15 and 16 years [8 girls (61.5% and 5 boys (38.5%]. The medical histories of all 13 children (100% showed repeated operations on the hip joint, ultimately resulting in arthroplasty with DBCA. All 13 children (100% underwent a total hip replacement. Upon hip replacement, all 13 patients (100% showed a pronounced thinning and hardening of the edges and the bottom of the acetabulum, which created some difficulties in the process of acetabular component implantation. The transformation of DBCA was not evident in any of the 13 cases (100%. Results. During the observation period of 3–5 years following total hip arthroplasty, all 13 cases (100% showed recovery in the range of motion and absence of pain. An important criterion for evaluating the quality of care was the complete social and domestic adaptation of all 13 children (100% during the period from 6 to 9 months following total

  14. Total hip arthroplasty in children who have undergone arthroplasty with demineralized bone-cartilage allocups

    Directory of Open Access Journals (Sweden)

    Vladimir E. Baskov

    2017-03-01

    Full Text Available Introduction. Treating children with degenerative dystrophic diseases of the hip joint has become one of the most acute problems in contemporary orthopedics. Until recently, we performed arthroplasty by demineralized bone-cartilage allocups (DBCA in the Clinic of the Hip Joint Pathology of the Turner Scientific and Research Institute for Children’s Orthopedics for patients showing clinical and radiological signs of irreversible destruction of the hip joint; we carried out this procedure to preserve the function of the lower limb. However, over the last 8 years, we have changed our protocol for children older than 12 years of age and have replaced DBCA with total hip replacement. In a number of cases, total hip replacement was performed after a previous intervention involving arthroplasty with DBCA. Objective. To determine the technical peculiarities of total hip replacement after a previous intervention involving arthroplasty with DBCA. Material and methods. We analyzed the results of treatment involving various types of hip pathology in 13 children (100% aged between 15 and 16 years [8 girls (61.5% and 5 boys (38.5%]. The medical histories of all 13 children (100% showed repeated operations on the hip joint, ultimately resulting in arthroplasty with DBCA. All 13 children (100% underwent a total hip replacement. Upon hip replacement, all 13 patients (100% showed a pronounced thinning and hardening of the edges and the bottom of the acetabulum, which created some difficulties in the process of acetabular component implantation. The transformation of DBCA was not evident in any of the 13 cases (100%. Results. During the observation period of 3–5 years following total hip arthroplasty, all 13 cases (100% showed recovery in the range of motion and absence of pain. An important criterion for evaluating the quality of care was the complete social and domestic adaptation of all 13 children (100% during the period from 6 to 9 months following total

  15. The effect of surface demineralization of cortical bone allograft on the properties of recombinant adeno-associated virus coatings.

    Science.gov (United States)

    Yazici, Cemal; Yanoso, Laura; Xie, Chao; Reynolds, David G; Samulski, R Jude; Samulski, Jade; Yannariello-Brown, Judith; Gertzman, Arthur A; Zhang, Xinping; Awad, Hani A; Schwarz, Edward M

    2008-10-01

    Freeze-dried recombinant adeno-associated virus (rAAV) coated structural allografts have emerged as an approach to engender necrotic cortical bone with host factors that will persist for weeks following surgery to facilitate revascularization, osteointegration, and remodeling. However, one major limitation is the nonporous cortical surface that prohibits uniform distribution of the rAAV coating prior to freeze-drying. To overcome this we have developed a demineralization method to increase surface absorbance while retaining the structural integrity of the allograft. Demineralized bone wafers (DBW) made from human femoral allograft rings demonstrated a significant 21.1% (73.6+/-3.9% versus 52.5+/-2.6%; pcoating versus mineralized controls. Co-incubation of rAAV-luciferase (rAAV-Luc) coated DBW with a monolayer of C3H10T1/2 cells in culture led to peak luciferase levels that were not significantly different from soluble rAAV-Luc controls (p>0.05), although the peaks occurred at 60h and 12h, respectively. To assess the transduction efficiency of rAAV-Luc coated DBW in vivo, we first performed a dose response with allografts containing 10(7), 10(9) or 10(10) particles that were surgically implanted into the quadriceps of mice, and assayed by in vivo bioluminescence imaging (BLI) on days 1, 3, 5, 7, 10, 14, and 21. The results demonstrated a dose response in which the DBW coated with 10(10) rAAV-Luc particles achieved peak gene expression levels on day 3, which persisted until day 21, and was significantly greater than the 10(7) dose throughout this time period (pcoated with 10(10) rAAV-Luc particles failed to demonstrate any significant differences in transduction kinetics or efficiency in vivo. Thus, surface demineralization of human cortical bone allograft increases its absorbance for uniform rAAV coating, without affecting vector transduction efficiency.

  16. Use of X-ray microprobe to diagnose bone tissue demineralization after caffeine administration Use of X-ray microprobe to diagnose bone tissue demineralization after caffeine administration

    Directory of Open Access Journals (Sweden)

    Marek Tomaszewski

    2012-10-01

    Full Text Available Caffeine is a methylxanthine which permeates the placenta. In studies on animals, it has been
    shown to produce teratogenic and embryotoxic effects in large doses. The objective of this study was to
    assess the influence of caffeine on the development of bone tissue, with particular reference to elemental
    bone composition using an X-ray microprobe. The research was conducted on rats. The fertilized females
    were randomly divided into an experimental and a control group. The experimental group was
    given caffeine orally in 30 mg/day doses from the 8th to the 21st day of pregnancy, while the control group
    was given water. The fetuses were used to assess the growth and mineralization of the skeleton. On the
    basis of double dyeing, a qualitative analysis of the bone morphology and mineralization was conducted.
    For calcium and potassium analysis, an X-ray microprobe was used. In 67 fetuses from the experimental
    group, changes in skeleton staining with the alcian-alizarin method were noticed. The frequency of the
    development of variants in the experimental group was statistically higher. In the experimental group,
    a significant decrease in the calcium level, as well as an increase in the potassium level, was observed.
    The X-ray microprobe’s undoubted advantage is that is offers a quick qualitative and quantitative analysis
    of the elemental composition of the examined samples. Employing this new technique may furnish us
    with new capabilities when investigating the essence of the pathology process.Caffeine is a methylxanthine which permeates the placenta. In studies on animals, it has been
    shown to produce teratogenic and embryotoxic effects in large doses. The objective of this study was to
    assess the influence of caffeine on the development of bone tissue, with particular reference to elemental
    bone composition using an X-ray microprobe. The research was conducted on

  17. Determination of orthodontic tooth movement and tissue reaction following demineralized freeze-dried bone allograft grafting intervention

    Science.gov (United States)

    Seifi, Massoud; Ghoraishian, Seyed Ahmad

    2012-01-01

    Background: Socket preservation after tooth extraction is one of the indications of bone grafting to enhance preorthodontic condition. The aim of this study is to determine the effects of socket preservation on the immediate tooth movement, alveolar ridge height preservation and orthodontic root resorption. Materials and Methods: In a split-mouth technique, twelve sites in three dogs were investigated as an experimental study. Crushed demineralized freeze-dried bone allograft (DFDBA) (CenoBone®) was used as the graft material. The defects were made by the extraction of 3rd premolar. On one side of each jaw, the defects were preserved by DFDBA and defects of the other side left opened as the control group. Simultaneously the teeth adjacent to the defects were pulled together by a NiTi coil spring. After eight weeks, the amount of (OTM), alveolar height, and root resorption were measured. Analysis of variance was used for purpose of comparison. Results: There was a slight increase in OTM at grafted sites as they were compared to the control sites (Presorption in control site and successful socket preservation in experimental site were observed. Reduction of root resorption at the augmented site was significant compared to the normal healing site (Presorption. PMID:22623939

  18. Determination of orthodontic tooth movement and tissue reaction following demineralized freeze-dried bone allograft grafting intervention

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2012-01-01

    Full Text Available Background: Socket preservation after tooth extraction is one of the indications of bone grafting to enhance preorthodontic condition. The aim of this study is to determine the effects of socket preservation on the immediate tooth movement, alveolar ridge height preservation and orthodontic root resorption. Materials and Methods: In a split-mouth technique, twelve sites in three dogs were investigated as an experimental study. Crushed demineralized freeze-dried bone allograft (DFDBA (CenoBone® was used as the graft material. The defects were made by the extraction of 3 rd premolar. On one side of each jaw, the defects were preserved by DFDBA and defects of the other side left opened as the control group. Simultaneously the teeth adjacent to the defects were pulled together by a NiTi coil spring. After eight weeks, the amount of (OTM, alveolar height, and root resorption were measured. Analysis of variance was used for purpose of comparison. Results: There was a slight increase in OTM at grafted sites as they were compared to the control sites (P<0.05. Also a significant bone resorption in control site and successful socket preservation in experimental site were observed. Reduction of root resorption at the augmented site was significant compared to the normal healing site (P<0.05. Conclusion: Using socket preservation, tooth movement can be immediately started without waiting for the healing of the recipient site. This can provide some advantages like enhanced rate of OTM, its approved effects on ridge preservation that reduces the chance of dehiscence and the reduction of root resorption.

  19. Evaluation of inactivation of intracanal antiseptics by dentin, demineralized dentin, dentin matrix and mineral component of dentin

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    Razmi H

    2007-01-01

    Full Text Available Background and Aim: Many studies have shown that microorganisms are the main cause of pulpal diseases and the main purpose of root canal therapy is their elimination from the root canal system. Antiseptic agents are used to reduce bacteria but their antibacterial activities differ from in vivo to in vitro studies and might be inactivated by dentin and its components in root canal space. This study was designed to investigate the effect of dentin on antibacterial activity of different antimicrobial agents. Materials and Methods: In this experimental study, two antibacterial agents (sodium hypochlorite and chlorhexidine with different concentrations were used in four experimental groups: Group 1: dentin, Group 2: demineralized dentin with EDTA, Group 3: dentin matrix and Group 4: dentin mineral component. The species used in this study was Entrococcus faecalis. Different concentration of agents were added to mixture of each experimental group and bacteria. At the baseline and after one and 24 hours, samples were collected and cultured. After incubation period, colonies were counted. Data were analyzed by Tukey test with p<0.05 as the limit of significance. Results: 2% and 0.2% chlorhexidine, and 5% sodium hypochlorite solutions at the three studied times eliminated Entrococcus faecalis completely. 1% sodium hypochlorite eliminated all bacteria in 1h and 24 hs. Statistical analysis showed significant differences between experimental and control groups (P<0.05. Sodium 1% hypochlorite at time 0, could reduce bacteria significantly (P<0.05 but didn’t eliminate them completely. Conclusion: Inactivation of intracanal antiseptics was not observed in this study. As elimination of bacteria occurred, application of these antibacterial agents are recommended in endodontic treatment. Further investigations on other antibacterial agents, other concentrations and shorter time intervals are recommended.

  20. Physical and chemical characteristics of the demineralized lyophylized bovine cortical bone sterilized by gamma irradiation

    International Nuclear Information System (INIS)

    Basril, A.; Febrida, A.; Hilmy, N.; Surtipanti, S.; Petrus, Z.

    1999-01-01

    The purpose of the studies were: 1) to ascertain the relationship between immersion time of bone in the Hydrochloride acid (HCl) solution and Calcium and Phosphor content in the bone and 2) to study the effects of irradiation on bone hardness. The methods used in these studies were according to American Association of Tissue Bank. The samples of bovine cortical bone in shape of I cm x I cm were demineralised in 0.6 N of HCl at room temperature until 72 hours. At 12, 24, 48, and 72 hours after demineralisation, 10 grams of demineralised samples were removed and labelled to reflect the demineralisation time. The pH values were monitored at 15 minutes intervals until the end of the process. Subsequently the wet samples were freeze-dried and Calcium and phosphor content were determined by X-ray diffraction. To observe the effects of radiation on bone hardness, the lyophilised cortical bovine bone was irradiated with gamma rays at the doses of 0, 10, 20, and 30 kGy and then were stored until 6 months. Results indicate that the beginning pH of the solution is 1. 1 and it increase sharply up to 2.3 after 12 hours of demineralisation and that pH become constant at 2.5 until the end of process. Calcium and phosphor content in the bone reduce in correlation with increasing of the pH. The beginning of Calcium and phosphor content in the bone are 36.4% and 25.3%, respectively and they reduce to 10.8% and 8.4% at the end of the process. The hardness of non irradiated and non demineralised, demineralised, irradiated, and demineralised irradiated of the cortical bone are 77.67; 65.21; 63.67; and 55.15 Vickers, respectively. The effects of irradiation up to 30 kGy on the hardness of the bone are not significant, but the storage time until 6 months give a significant of reduction. It can be concluded using this method the minimum residual of Calcium concentration in the bone is 10.8%

  1. Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study

    Science.gov (United States)

    Mogharehabed, Ahmad; Birang, Reza; Torabinia, Nakisa; Nasiri, Saman; Behfarnia, Parichehr

    2014-01-01

    Background: The accelerating effect of plasma rich in growth factors (PRGFs) in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA). Materials and Methods: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA). Significant levels were set at 0.05. Results: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm). The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm²). The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm²). The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm²). Conclusion: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant. PMID:25225559

  2. Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study

    Directory of Open Access Journals (Sweden)

    Ahmad Mogharehabed

    2014-01-01

    Full Text Available Background: The accelerating effect of plasma rich in growth factors (PRGFs in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA. Materials and Methods: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA. Significant levels were set at 0.05. Results: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm. The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm². The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm². The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm². Conclusion: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant.

  3. Patterns of distribution of phosphomono-esterases on surfaces of demineralized bone

    DEFF Research Database (Denmark)

    Kirkeby, S; Vilmann, H

    1979-01-01

    Decalcification over short periods (5 days) with MnNa2 EDTA, MgNa2 EDTA and EGTA according to a method described in the present paper, creates sections of high quality with simultaneous good preservation of phosphomonoesterases on bone surfaces. In fact, the enzyme distribution seems to be compar...

  4. In vitro cartilage tissue engineering using cancellous bone matrix gelatin as a biodegradable scaffold

    International Nuclear Information System (INIS)

    Yang Bo; Yin Zhanhai; Cao Junling; Shi Zhongli; Zhang Zengtie; Liu Fuqiang; Song Hongxing; Caterson, Bruce

    2010-01-01

    In this study, we constructed tissue-engineered cartilage using allogeneic cancellous bone matrix gelatin (BMG) as a scaffold. Allogeneic BMG was prepared by sequential defatting, demineralization and denaturation. Isolated rabbit chondrocytes were seeded onto allogeneic cancellous BMG, and cell-BMG constructs were harvested after 1, 3 and 6 weeks for evaluation by hematoxylin and eosin staining for overall morphology, toluidine blue for extracellular matrix (ECM) proteoglycans, immunohistochemical staining for collagen type II and a transmission electron microscope for examining cellular microstructure on BMG. The prepared BMG was highly porous with mechanical strength adjustable by duration of demineralization and was easily trimmed for tissue repair. Cancellous BMG showed favorable porosity for cell habitation and metabolism material exchange with larger pore sizes (100-500 μm) than in cortical BMG (5-15 μm), allowing cell penetration. Cancellous BMG also showed good biocompatibility, which supported chondrocyte proliferation and sustained their differentiated phenotype in culture for up to 6 weeks. Rich and evenly distributed cartilage ECM proteoglycans and collagen type II were observed around chondrocytes on the surface and inside the pores throughout the cancellous BMG. Considering the large supply of banked bone allografts and relatively convenient preparation, our study suggests that allogeneic cancellous BMG is a promising scaffold for cartilage tissue engineering.

  5. In vitro cartilage tissue engineering using cancellous bone matrix gelatin as a biodegradable scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Yang Bo; Yin Zhanhai; Cao Junling; Shi Zhongli; Zhang Zengtie; Liu Fuqiang [College of Medicine, Xi' an Jiaotong University, Yanta West Road, No 76, Yanta District, Xi' an, Shaanxi Province 710061 (China); Song Hongxing [Department of Orthopedics, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Caterson, Bruce, E-mail: caojl@mail.xjtu.edu.c [Connective Tissue Biology Laboratories, Cardiff School of Biosciences, Cardiff University, Biomedical Building, Museum Avenue, Cardiff, CF10 3US (United Kingdom)

    2010-08-01

    In this study, we constructed tissue-engineered cartilage using allogeneic cancellous bone matrix gelatin (BMG) as a scaffold. Allogeneic BMG was prepared by sequential defatting, demineralization and denaturation. Isolated rabbit chondrocytes were seeded onto allogeneic cancellous BMG, and cell-BMG constructs were harvested after 1, 3 and 6 weeks for evaluation by hematoxylin and eosin staining for overall morphology, toluidine blue for extracellular matrix (ECM) proteoglycans, immunohistochemical staining for collagen type II and a transmission electron microscope for examining cellular microstructure on BMG. The prepared BMG was highly porous with mechanical strength adjustable by duration of demineralization and was easily trimmed for tissue repair. Cancellous BMG showed favorable porosity for cell habitation and metabolism material exchange with larger pore sizes (100-500 {mu}m) than in cortical BMG (5-15 {mu}m), allowing cell penetration. Cancellous BMG also showed good biocompatibility, which supported chondrocyte proliferation and sustained their differentiated phenotype in culture for up to 6 weeks. Rich and evenly distributed cartilage ECM proteoglycans and collagen type II were observed around chondrocytes on the surface and inside the pores throughout the cancellous BMG. Considering the large supply of banked bone allografts and relatively convenient preparation, our study suggests that allogeneic cancellous BMG is a promising scaffold for cartilage tissue engineering.

  6. Quantitative determination of anticonvulsant-induced bone demineralization by an improved x-ray densitometry technique

    Energy Technology Data Exchange (ETDEWEB)

    Wolschendorf, K.; Vanselow, K.; Schulz, H.; Moeller, W.D.

    1983-10-01

    Quantitative studies of the influence of anticonvulsant drugs on bone mineral content of 88 epileptics were performed by a microcomputer-aided densitometer system. The results showed that the mineral content decreases significantly with the duration of the therapy. This decrease was found to be approximately 1.2% per year for a Diphenylhydantoin (DPH) monotherapy and 1.8% per year and 2.0% per year for a DPH plus Phenobarbital and DPH plus Carbamazepin combination therapy.

  7. A comparison of commercially available demineralized bone matrices with and without human mesenchymal stem cells in a rodent spinal fusion model.

    Science.gov (United States)

    Hayashi, Tetsuo; Lord, Elizabeth L; Suzuki, Akinobu; Takahashi, Shinji; Scott, Trevor P; Phan, Kevin; Tian, Haijun; Daubs, Michael D; Shiba, Keiichiro; Wang, Jeffrey C

    2016-07-01

    OBJECTIVE The efficacy of some demineralized bone matrix (DBM) substances has been demonstrated in the spinal fusion of rats; however, no previous comparative study has reported the efficacy of DBM with human mesenchymal stem cells (hMSCs). There is an added cost to the products with stem cells, which should be justified by improved osteogenic potential. The purpose of this study is to prospectively compare the fusion rates of 3 different commercially available DBM substances, both with and without hMSCs. METHODS Posterolateral fusion was performed in 32 mature athymic nude rats. Three groups of 8 rats were implanted with 1 of 3 DBMs: Trinity Evolution (DBM with stem cells), Grafton (DBM without stem cells), or DBX (DBM without stem cells). A fourth group with no implanted material was used as a control group. Radiographs were obtained at 2, 4, and 8 weeks. The rats were euthanized at 8 weeks. Overall fusion was determined by manual palpation and micro-CT. RESULTS The fusion rates at 8 weeks on the radiographs for Trinity Evolution, Grafton, and DBX were 8 of 8 rats, 3 of 8 rats, and 5 of 8 rats, respectively. A significant difference was found between Trinity Evolution and Grafton (p = 0.01). The overall fusion rates as determined by micro-CT and manual palpation for Trinity Evolution, Grafton, and DBX were 4 of 8 rats, 3 of 8 rats, and 3 of 8 rats, respectively. The Trinity Evolution substance had the highest overall fusion rate, however no significant difference was found between groups. CONCLUSIONS The efficacies of these DBM substances are demonstrated; however, the advantage of DBM with hMSCs could not be found in terms of posterolateral fusion. When evaluating spinal fusion using DBM substances, CT analysis is necessary in order to not overestimate fusion.

  8. The use of acetone to enhance the infiltration of HA nanoparticles into a demineralized dentin collagen matrix.

    Science.gov (United States)

    Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

    2016-03-01

    This study investigates the role of acetone, as a carrier for nano-hydroxyapatite (nano-HA) in solution, to enhance the infiltration of fully demineralized dentin with HA nanoparticles (NPs). Dentin specimens were fully demineralized and subsequently infiltrated with two types of water-based nano-HA solutions (one containing acetone and one without). Characterization of the dentin surfaces and nano-HA particles was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface wettability and infiltration capacity of the nano-HA solutions were quantified by means of contact angle measurements and energy dispersive X-ray spectroscopy (EDS), respectively. Contact angle measurements were taken at baseline and repeated at regular intervals to assess the effect of acetone. The P and Ca levels of infiltrated dentin specimens were measured and compared to sound dentin and non-infiltrated controls. The presence of acetone resulted in an eight-fold decrease in the contact angles of the nano-HA solutions recorded on the surface of demineralized dentin compared to nano-HA solutions without acetone (one-way ANOVA, pacetone. Infiltration of demineralized dentin with the nano-HA solution containing acetone restored the lost mineral content by 50%, whereas the mean mineralization values for P and Ca in dentin treated with the acetone-free nano-HA solution were less than 6%. Acetone was shown to act as a vehicle to enhance the capacity to infiltrate demineralized dentin with HA NPs. The successful infiltration of dentin collagen with HA NPs provides a suitable scaffold, whereby the infiltrated HA NPs have the potential to act as seeds that may initiate heterogenous mineral growth when exposed to an appropriate mineral-rich environment. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. A comparative evaluation of extraction socket preservation with demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin: A clinical and radiographic study

    Directory of Open Access Journals (Sweden)

    Dhaval J Thakkar

    2016-01-01

    Full Text Available Aims: To investigate clinically and radiographically, the bone fill in extraction sockets using demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin (PRF. Materials and Methods: A randomized controlled clinical trial was carried out on 36 nonrestorable single-rooted teeth sites. Sites were randomized into demineralized freeze-dried bone allograft (DFDBA combined with PRF - test and DFDBA - control groups using a coin toss method. After the placement of graft material, collagen membrane was used to cover it. The clinical parameters recorded were ridge width and ridge height. All the parameters were recorded at baseline and at 90 and 180 days. Statistical Analysis Used: Independent t-test and paired t-test. Results: In both groups, there is significant reduction in loss of ridge width and ridge height from baseline to 90 days (P < 0.001, baseline to 180 days (P < 0.001, and 90-180 days (P < 0.001. However, when both the groups were compared the test group favored in the reduction of ridge width while there was no statistical difference in reduction of ridge height among at different intervals. Conclusions: Although DFDBA is considered as an ideal graft material, PRF can be used as an adjunctive with DFDBA for socket preservation.

  10. Osteogenic Matrix Cell Sheets Facilitate Osteogenesis in Irradiated Rat Bone

    Directory of Open Access Journals (Sweden)

    Yoshinobu Uchihara

    2015-01-01

    Full Text Available Reconstruction of large bone defects after resection of malignant musculoskeletal tumors is a significant challenge in orthopedic surgery. Extracorporeal autogenous irradiated bone grafting is a treatment option for bone reconstruction. However, nonunion often occurs because the osteogenic capacity is lost by irradiation. In the present study, we established an autogenous irradiated bone graft model in the rat femur to assess whether osteogenic matrix cell sheets improve osteogenesis of the irradiated bone. Osteogenic matrix cell sheets were prepared from bone marrow-derived stromal cells and co-transplanted with irradiated bone. X-ray images at 4 weeks after transplantation showed bridging callus formation around the irradiated bone. Micro-computed tomography images at 12 weeks postoperatively showed abundant callus formation in the whole circumference of the irradiated bone. Histology showed bone union between the irradiated bone and host femur. Mechanical testing showed that the failure force at the irradiated bone site was significantly higher than in the control group. Our study indicates that osteogenic matrix cell sheet transplantation might be a powerful method to facilitate osteogenesis in irradiated bones, which may become a treatment option for reconstruction of bone defects after resection of malignant musculoskeletal tumors.

  11. Clinical application of radiation sterilized demineralized freeze dried bone allograft (DFDBA) and DFDBA combined with bovine periosteum membrane in periodontal defects

    International Nuclear Information System (INIS)

    Tantin R Dwijartini; Paramita Pandansari; Basril Abbas; Nazly Hilmy

    2008-01-01

    Full text: The objective of this report is to evaluate the effects of Radiation Sterilized Demineralized Freeze Dried Bone Allograft (DFDBA) and DFDBA combined with Bovine Periosteum Membrane (BPM) as well as BPM only in some cases of Periodontal Defects. BPM was used as a guided tissue regeneration. This study was carried out to 26 patients as follows : 10 cases for periodontal pocket using only DFDBA and DFDBA combined with BPM for 16 cases which consist of 10 cases of post extraction socket, 5 cases of gingival recession and one case of maxillary bone defect. DFDBA and periosteum membrane used were produced by BATAN Research Tissue Bank. Flap operation was done for all of the treatments, and followed by filling with DFDBA and/or DFDBA combined with periosteum membrane or BPM only. Evaluations were done up to 6 months. Parameters observed were the improvement of bone level, clinical attachment level, pocket depth and gingival margin location as well as increasing the thickness of maxillary bone. All of those evaluations were done by clinical observation and x-ray examination. Results obtained show that the improvement of clinical attachment level, reduces the pocket depth and increases bone density happened in all cases observed. It was also shows that BPM can be used as a guided tissue regeneration. No rejection could be observed in all of those cases. This study clearly indicated that DFDBA had an inductive effect on the formation of new bone and connective tissue. It can be concluded that DFDBA and Bovine Periosteum Membrane are promising to be used in treatment of the case of Periodontal Defects. (Author)

  12. Evaluation of bioactive glass and demineralized freeze dried bone allograft in the treatment of periodontal intraosseous defects: A comparative clinico-radiographic study

    Directory of Open Access Journals (Sweden)

    Kishore Kumar Katuri

    2013-01-01

    Full Text Available Aim: The purpose of this study was to evaluate the efficacy of demineralized freeze dried bone allograft (DFDBA and bioactive glass by clinically and radiographically in periodontal intrabony defects for a period of 12 months. Materials and Methods: Ten systemically healthy patients diagnosed with chronic periodontitis, with radiographic evidence of at least a pair of contralateral vertical osseous defects were included in this study. Defect on one-side is treated with DFDBA and the other side with bioactive glass. Clinical and radiographic measurements were made at baseline 6 month and 12 month after the surgery. Results: Compared to baseline, the 12 month results indicated that both treatment modalities resulted in significant changes in all clinical parameters (gingival index, probing depth, clinical attachment level (CAL and radiographic parameters (bone fill; P < 0.001FNx01. However, sites treated with DFDBA exhibited statistically significantly more changes compared to the bioactive glass in probing depth reduction (2.5 ± 0.1 mm vs. 1.8 ± 0.1 mm CAL gain 2.4 ± 0.1 mm versus 1.7 ± 0.2 mm; ( P < 0.001FNx01. At 12 months, sites treated with bioactive glass exhibited 56.99% bone fill and 64.76% bone fill for DFDBA sites, which is statistically significant ( P < 0.05FNx01. Conclusion: After 12 months, there was a significant difference between the two materials with sites grafted with DFDBA showing better reduction in probing pocket depth, gain in CAL and a greater percentage of bone fill when compared to that of bioactive glass.

  13. Management Strategy for Unicameral Bone Cyst

    OpenAIRE

    Chin-Yi Chuo; Yin-Chih Fu; Song-Hsiung Chien; Gau-Tyan Lin; Gwo-Jaw Wang

    2003-01-01

    The management of a unicameral bone cyst varies from percutaneous needle biopsy, aspiration, and local injection of steroid, autogenous bone marrow, or demineralized bone matrix to the more invasive surgical procedures of conventional curettage and grafting (with autogenous or allogenous bone) or subtotal resection with bone grafting. The best treatment for a unicameral bone cyst is yet to be identified. Better understanding of the pathology will change the concept of management. The aim of t...

  14. Effect of mangosteen peel extract combined with demineralized freezed-dried bovine bone xenograft on osteoblast and osteoclast formation in post tooth extraction socket

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2016-12-01

    Full Text Available Background: Tooth extraction, a common procedure in dentistry, can cause bone resorption during socket healing. Therefore, it is important to perform socket preservation procedure to maintain alveolar bone. Providing a combination of mangosteen peel extract with demineralized freezed-dried bovine bone xenograft (DFDBBX in tooth extraction socket was expected to accelerate alveol bone formation. Purpose: This study aims to determine the effect of mangosteen peel extract combined with DFDBBX introduced into the socket of post tooth extraction on the formation of osteoblasts and osteoclasts. Method: Twenty-eight (28 Cavia cobayas were divided into four groups. Extraction to the lower left incisor of Cavia cobaya was performed. The extraction socket was filled with 25 gram of PEG (group I as a control, active materials consisted of mangosteen peel extract and DFDBBX 0.5% (group II, active materials consisted of mangosteen peel extract and DFDBBX 1% (group III, and active materials consisted of mangosteen peel extract and DFDBBX 2% (group IV. After thirty days, those Cavia cobayas were sacrificed. By using HE on Histopatological examination, the number of osteoblasts and osteoclasts were measured by light microscope with 400 times of magnification. The statistical analysis was then performed using oneway Anova & TukeyHSD test. Result: The component active materials consisted of mangosteen peel extract and DFDBBX 2% had the most significant results related to the formation of osteoblasts and osteoclasts. Conclusion: Mangosteen peel extract combined with DFDBBX can increase osteoblasts and decrease osteoclasts in the socket of tooth extraction in Cavia cobaya. The combination of mangosteen peel extract and DFDBBX 2% is the most effective material in increasing osteoblast and decreasing osteoclast.

  15. Steering the osteoclast through the demineralization-collagenolysis balance

    DEFF Research Database (Denmark)

    Søe, Kent; Merrild, Ditte Marie Horslev; Delaissé, Jean-Marie

    2013-01-01

    are generated when collagen degradation is slower than demineralization, and trenches when collagen degradation is as fast as demineralization. Next we treated the osteoclasts with a low dose of a carbonic anhydrase inhibitor to slightly decrease the rate of demineralization, thereby allowing collagen......, forming a pit, and continues parallel to the bone surface, forming a trench. Importantly, we show that the progress of the osteoclast along this route depends on the balance between the rate of collagenolysis and demineralization. We propose that the osteocytes and bone lining cells surrounding...... the osteoclast may act on this balance to steer the osteoclast resorptive activity in order to give the excavations a specific shape....

  16. Methods for histochemical demonstration of vascular structures at the muscle-bone interface from cryostate sections of demineralized tissue

    DEFF Research Database (Denmark)

    Kirkeby, S

    1981-01-01

    In tissue decalcified with MgNa2EDTA at a neutral pH activity for ATPase can used be for demonstration of the vascular structures at the muscle-bone interface. The GOMORI method for alkaline phosphatase is only of value, when fresh unfixed tissue is to be examined. The azo-dye method for alkaline...... phosphatase failed to give satisfactory results, and so did the alpha-amylase PAS method. 5'-nucleotidase activity is present in both capillaries and in cells lining the surfaces of bones, while larger blood vessels are poorly stained....

  17. Coherent scattering and matrix correction in bone-lead measurements

    International Nuclear Information System (INIS)

    Todd, A.C.

    2000-01-01

    The technique of K-shell x-ray fluorescence of lead in bone has been used in many studies of the health effects of lead. This paper addresses one aspect of the technique, namely the coherent conversion factor (CCF) which converts between the matrix of the calibration standards and those of human bone. The CCF is conventionally considered a constant but is a function of scattering angle, energy and the elemental composition of the matrices. The aims of this study were to quantify the effect on the CCF of several assumptions which may not have been tested adequately and to compare the CCFs for plaster of Paris (the present matrix of calibration standards) and a synthetic apatite matrix. The CCF was calculated, using relativistic form factors, for published compositions of bone, both assumed and assessed compositions of plaster, and the synthetic apatite. The main findings of the study were, first, that impurities in plaster, lead in the plaster or bone matrices, coherent scatter from non-bone tissues and the individual subject's measurement geometry are all minor or negligible effects; and, second, that the synthetic apatite matrix is more representative of bone mineral than is plaster of Paris. (author)

  18. A quantitative determination of anticonvulsant-induced bone demineralization by an improved x-ray densitometry technique

    International Nuclear Information System (INIS)

    Wolschendorf, K.; Vanselow, K.; Schulz, H.; Moeller, W.D.

    1983-01-01

    Quantitative studies of the influence of anticonvulsant drugs on bone mineral content of 88 epileptics were performed by a microcomputer-aided densitometer system. The results showed that the mineral content decreases significantly with the duration of the therapy. This decrease was found to be approximately 1.2% per year for a Diphenylhydantoin (DPH) monotherapy and 1.8% per year and 2.0% per year for a DPH plus Phenobarbital and DPH plus Carbamazepin combination therapy. (orig.)

  19. A study of 23 unicameral bone cysts of the calcaneus: open chip allogeneic bone graft versus percutaneous injection of bone powder with autogenous bone marrow.

    Science.gov (United States)

    Park, Il-Hyung; Micic, Ivan Dragoljub; Jeon, In-Ho

    2008-02-01

    The treatment of unicameral bone cyst varies from percutaneous needle biopsy, aspiration and local injection of steroid, autologous bone marrow, or demineralized bone matrix to curettage and open bone-grafting. The purpose of this study was to compare the results of open chip allogeneic bone graft versus percutaneous injection of demineralized bone powder with autogenous bone marrow in management of calcaneal cysts. Twenty-three calcaneal unicameral cysts in 20 patients were treated. Lyophilized irradiated chip allogeneic bone (CAB) and autogenous bone marrow were used for treatment of 13 cysts in 11 patients, and 10 cysts in 9 patients were treated with percutaneous injection of irradiated allogeneic demineralized bone powder (DBP) and autogenous bone marrow. There were 11 males and 9 female patients with mean age of 17 years. The patients were followed for an average of 49.4 months. Complete healing was achieved in 9 cysts treated with chip allogeneic bone and in 5 cysts treated with powdered bone. Four cysts treated with CAB and 3 cysts treated with DBP healed with a defect. Two cysts treated with powdered bone and autogenous bone marrow were classified as persistent. No infections or pathological fractures were observed during the followup period. Percutaneous injection of a mixture of allogeneic bone powder with autogenous bone marrow is a minimal invasive method and could be an effective alternative in the treatment of unicameral calcaneal bone cysts. The postoperative morbidity was low, the hospital stay was brief, and patient's comfort for unrestricted activity was enhanced.

  20. Bone induction by composites of bioresorbable carriers and demineralized bone in rats: a comparative study of fibrin-collagen paste, fibrin sealant, and polyorthoester with gentamicin

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E; Bang, G

    1992-01-01

    fibrin-collagen paste and fibrin sealant inhibited bone induction and produced a chronic inflammation; part of the fibrin-collagen paste was still present at 4 weeks. Polyorthoester with gentamicin was almost completely absorbed, induced minimal tissue reaction, and did not inhibit osteoinduction....

  1. Repair of massively defected hemi-joints using demineralized osteoarticular allografts with protected cartilage.

    Science.gov (United States)

    Li, Siming; Yang, Xiaohong; Tang, Shenghui; Zhang, Xunmeng; Feng, Zhencheng; Cui, Shuliang

    2015-08-01

    Surgical replacement of massively defected joints necessarily relies on osteochondral grafts effective to both of bone and cartilage. Demineralized bone matrix (DBM) retains the osteoconductivity but destroys viable chondrocytes in the cartilage portion essential for successful restoration of defected joints. This study prepared osteochondral grafts of DBM with protected cartilage. Protected cartilage portions was characterized by cellular and molecular biology and the grafts were allogenically used for grafting. Protected cartilage showed similar histomorphological structure and protected proteins estimated by total proteins and cartilage specific proteins as in those of fresh controls when DBMs were generated in bone portions. Such grafts were successfully used for simultaneously repair of bone and cartilage in massively defected osteoarticular joints within 16 weeks post-surgery. These results present an allograft with clinical potential for simultaneous restoration of bone and cartilage in defected joints.

  2. "Repair of cranial bone defects using endochondral bone matrix gelatin in rat "

    Directory of Open Access Journals (Sweden)

    "Sobhani A

    2001-05-01

    Full Text Available Bone matrix gelatin (BMG has been used for bone induction intramuscularly and subcutaneously by many investigators since 1965. More recently, some of the researchers have used BMG particles for bone repair and reported various results. In present study for evaluation of bone induction and new bone formation in parital defects, BMG particles were used in five groups of rats. The BMG was prepared as previously described using urist method. The defects wee produced with 5 –mm diameter in pariteal bones and filled by BMG particles. No BMG was used in control group.For evaluation of new bone formation and repair, the specimens were harvested on days 7 , 14 , 21 and 28 after operation. The samples were processed histologically, stained by H& E, alizarin red S staining, and Alcian blue, and studied by a light microscope.The results are as follows:In control group: Twenty-eight days after operation a narrow rim of new bone was detectable attached to the edge of defect.In BMG groups: At day 7 after operation young chondroblast cells appeared in whole area of defect. At 14th day after operation hypertrophic chondrocytes showed by Alcian blue staining and calcified cartilage were detectable by Alizarin red S staining. The numerous trabeculae spicules, early adult osteocytes and highly proliferated red bone marrow well developed on dayd 21 . finally typic bone trabeculae with regulated osteoblast cells and some osteoclast cells were detectable at day 28 after operation. In conclusion,BMG could stimulate bone induction and new bone formation in bony defects. So, it seems that BMG could be a godd biomaterial substance for new bone inducation in bone defects

  3. Microarchitecture of the Augmented Bone Following Sinus Elevation with an Albumin Impregnated Demineralized Freeze-Dried Bone Allograft (BoneAlbumin versus Anorganic Bovine Bone Mineral: A Randomized Prospective Clinical, Histomorphometric, and Micro-Computed Tomography Study

    Directory of Open Access Journals (Sweden)

    Kivovics Márton

    2018-01-01

    Full Text Available Serum albumin has been identified as an endogenous protein that is integral to early bone regeneration. We hypothesized that albumin addition to allografts may result in better bone remodeling than what can be achieved with anorganic xenografts. Sinus elevations were performed at 32 sites of 18 patients with the lateral window technique. Sites either received filling with an anorganic bovine bone mineral (ABBM, BioOss, Geistlich, CH or albumin impregnated allograft (BoneAlbumin, OrthoSera, AT. After 6-months patients received dental implants and 16 bone core biopsy samples were obtained from the ABBM filled, and 16 from the BoneAlbumin augmented sites. The biopsies were examined by histomorphometry and µCT. Percentage of the residual graft in the BoneAlbumin group was 0–12.7%, median 5.4% vs. ABBM 6.3–35.9%, median 16.9%, p < 0.05. Results of the µCT analysis showed that the microarchitecture of the augmented bone in the BoneAlbumin group resembles that of the native maxilla in morphometric parameters Trabecular Pattern Factor and Connectivity. Our data show that while ABBM successfully integrates into the newly formed bone tissue as persisting particles, BoneAlbumin is underway towards complete remodeling with new bone closely resembling that of the intact maxilla.

  4. Clinical and radiological studies upon a combined method for guided bone regeneration in experimental mandibular defects in dogs - a preliminary communication

    International Nuclear Information System (INIS)

    Borissov, I.; Uzunov, N.; Paskalev, M.

    2004-01-01

    The treated bone defects were compared clinically and radiologically. After a 3-month period of survey, the best results were obtained in the group treated with partially demineralized bone matrix, enzymatically processed and lyophilized dura mater and mucoperiosteal flap. The placement of titanium screw dental implants did not impair the guided bone regeneration, that was confirmed by their good osteointegration

  5. Marginal zinc deficiency in pregnant rats impairs bone matrix formation and bone mineralization in their neonates.

    Science.gov (United States)

    Nagata, Masashi; Kayanoma, Megumu; Takahashi, Takeshi; Kaneko, Tetsuo; Hara, Hiroshi

    2011-08-01

    Zinc (Zn) deficiency during pregnancy may result in a variety of defects in the offspring. We evaluated the influence of marginal Zn deficiency during pregnancy on neonatal bone status. Nine-week-old male Sprague-Dawley rats were divided into two groups and fed AIN-93G-based experimental diets containing 35 mg Zn/kg (Zn adequately supplied, N) or 7 mg Zn/kg (low level of Zn, L) from 14-day preconception to 20 days of gestation, that is, 1 day before normal delivery. Neonates were delivered by cesarean section. Litter size and neonate weight were not different between the two groups. However, in the L-diet-fed dam group, bone matrix formation in isolated neonatal calvaria culture was clearly impaired and was not recovered by the addition of Zn into the culture media. Additionally, serum concentration of osteocalcin, as a bone formation parameter, was lower in neonates from the L-diet-fed dam group. Impaired bone mineralization was observed with a significantly lower content of phosphorus in neonate femurs from L-diet-fed dams compared with those from N-diet-fed dams. Moreover, Zn content in the femur and calvaria of neonates from the L-diet group was lower than that of the N-diet-fed group. In the marginally Zn-deficient dams, femoral Zn content, serum concentrations of Zn, and osteocalcin were reduced when compared with control dams. We conclude that maternal Zn deficiency causes impairment of bone matrix formation and bone mineralization in neonates, implying the importance of Zn intake during pregnancy for proper bone development of offspring.

  6. Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhuoyue [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Song, Yue [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Zhang, Jing [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Key Laboratory of Resource Biology and Modern Biotechnology in Western China, Ministry of Education, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province, 710069 (China); Liu, Wei [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Cui, Jihong, E-mail: cjh@nwu.edu.cn [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Key Laboratory of Resource Biology and Modern Biotechnology in Western China, Ministry of Education, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province, 710069 (China); and others

    2017-03-01

    Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2 months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. - Highlights: • We laminated the nHA/PHB layers to obtain a scaffold for bone tissue engineering. • The laminated scaffold performed optimized cell-loading capacity. • MSCs exhibited osteogenic phenotypes on the laminated scaffold. • Osteoid tissue formed throughout the laminated scaffold after 2 months in vivo. The laminated bio-composite scaffolds can be applied to bone regeneration.

  7. Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering

    International Nuclear Information System (INIS)

    Chen, Zhuoyue; Song, Yue; Zhang, Jing; Liu, Wei; Cui, Jihong

    2017-01-01

    Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2 months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. - Highlights: • We laminated the nHA/PHB layers to obtain a scaffold for bone tissue engineering. • The laminated scaffold performed optimized cell-loading capacity. • MSCs exhibited osteogenic phenotypes on the laminated scaffold. • Osteoid tissue formed throughout the laminated scaffold after 2 months in vivo. The laminated bio-composite scaffolds can be applied to bone regeneration.

  8. The effect of combined Moringa oleifera and demineralized freeze-dried bovine bone xenograft on the amount of osteoblast and osteoclast in the healing of tooth extraction socket of Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Rostiny Rostiny

    2016-12-01

    Full Text Available Background: Alveolar bone has an important role in providing support to teeth and dentures. Loss of support caused by alveolar resorption will cause functional and aesthetic problems. Preservation socket using bone graft is one way to maintain the dimensions of the alveolar bone. Moringa oleifera leaf can increase the activity of bone graft in the formation of new bone. Purpose: This study was aimed to evaluate the effect of combined Moringa oleivera leaf extract and demineralized freeze-dried bovine bone xenograft (DFDBBX towards the formation of osteoblasts and osteoclasts in the tooth extraction sockets of cavia cobaya. Method: This study used 28 cavia cobayas divided into four groups. The combination of Moringa oleifera leaf extract and DFDBBX was inducted into the sockets of lower incisor tooth with certain dose in each group, ointment 1 containing PEG (a mixture of PEG 400 and PEG 4000 for control group, ointment 2 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active subtance consentration of 0.5% for group 1, ointment 3 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance concentration of 1% for group 2, and Ointment 4 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance consentration of 2% for group 3. paraffin block preparations were made for histopathology examination using hematoxylin eosin staining. Result: The results showed that there were significant differences of the number of osteoblasts and osteoclasts in each treatment group (p <0.05. Conclusion: It can be concluded that the combination of Moringa oleifera leaf extract and DFDBBX at 2% cocentration can increase the number of osteoblasts and decrease osteoclasts in the healing of tooth extraction sockets of cavia cobaya.

  9. Human interleukin 1β (IL-1β), a more powerful inducer of bone demineralization than interleukin 1α (IL-1α), parathyroid hormone (PTH) or prostaglandin E2 (PGE2) in vitro

    International Nuclear Information System (INIS)

    Chin, R.C.; Hodges, Y.C.; Allison, A.C.

    1986-01-01

    Effects of human IL-1α and IL-1β, prepared by recombinant DNA technology on cultures of rat fetal long bones, prelabelled with 45 Ca were studied. IL-1β was found to be the most powerful inducer of bone calcium loss so far known. Maximal activity (2.5 times the control rate of calcium loss) was induced by IL-1β at concentrations between 1 x 10 -10 M to 6 x 10 -12 M. With IL-1α maximal activity (1.5 times the control rate of calcium loss) was obtained at 6 x 10 -10 M. With bovine PTH (1-34) maximal activity (1.8 times the control rate of calcium loss) was obtained at 1 x 10 -8 M. With PGE 2 maximal activity (1.6 times the control rate of calcium loss) was obtained at 1 x 10 -7 M. The calcium loss induced by IL-1β was inhibited in the presence of 1 x 10 -7 M indomethacin, 5 x 10 -5 M naproxen or ketorolac, or 5 x 10 -6 M cyclohexamide. These findings suggest that protein synthesis and prostaglandin formation are required to mediate bone demineralization induced by IL-1β

  10. Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering.

    Science.gov (United States)

    Chen, Zhuoyue; Song, Yue; Zhang, Jing; Liu, Wei; Cui, Jihong; Li, Hongmin; Chen, Fulin

    2017-03-01

    Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Osteoblast Differentiation and Bone Matrix Formation In Vivo and In Vitro.

    Science.gov (United States)

    Blair, Harry C; Larrouture, Quitterie C; Li, Yanan; Lin, Hang; Beer-Stoltz, Donna; Liu, Li; Tuan, Rocky S; Robinson, Lisa J; Schlesinger, Paul H; Nelson, Deborah J

    2017-06-01

    We review the characteristics of osteoblast differentiation and bone matrix synthesis. Bone in air breathing vertebrates is a specialized tissue that developmentally replaces simpler solid tissues, usually cartilage. Bone is a living organ bounded by a layer of osteoblasts that, because of transport and compartmentalization requirements, produce bone matrix exclusively as an organized tight epithelium. With matrix growth, osteoblasts are reorganized and incorporated into the matrix as living cells, osteocytes, which communicate with each other and surface epithelium by cell processes within canaliculi in the matrix. The osteoblasts secrete the organic matrix, which are dense collagen layers that alternate parallel and orthogonal to the axis of stress loading. Into this matrix is deposited extremely dense hydroxyapatite-based mineral driven by both active and passive transport and pH control. As the matrix matures, hydroxyapatite microcrystals are organized into a sophisticated composite in the collagen layer by nucleation in the protein lattice. Recent studies on differentiating osteoblast precursors revealed a sophisticated proton export network driving mineralization, a gene expression program organized with the compartmentalization of the osteoblast epithelium that produces the mature bone matrix composite, despite varying serum calcium and phosphate. Key issues not well defined include how new osteoblasts are incorporated in the epithelial layer, replacing those incorporated in the accumulating matrix. Development of bone in vitro is the subject of numerous projects using various matrices and mesenchymal stem cell-derived preparations in bioreactors. These preparations reflect the structure of bone to variable extents, and include cells at many different stages of differentiation. Major challenges are production of bone matrix approaching the in vivo density and support for trabecular bone formation. In vitro differentiation is limited by the organization and

  12. Anabolic action of parathyroid hormone (PTH) does not compromise bone matrix mineral composition or maturation.

    Science.gov (United States)

    Vrahnas, Christina; Pearson, Thomas A; Brunt, Athena R; Forwood, Mark R; Bambery, Keith R; Tobin, Mark J; Martin, T John; Sims, Natalie A

    2016-12-01

    Intermittent administration of parathyroid hormone (PTH) is used to stimulate bone formation in patients with osteoporosis. A reduction in the degree of matrix mineralisation has been reported during treatment, which may reflect either production of undermineralised matrix or a greater proportion of new matrix within the bone samples assessed. To explore these alternatives, high resolution synchrotron-based Fourier Transform Infrared Microspectroscopy (sFTIRM) coupled with calcein labelling was used in a region of non-remodelling cortical bone to determine bone composition during anabolic PTH treatment compared with region-matched samples from controls. 8week old male C57BL/6 mice were treated with vehicle or 50μg/kg PTH, 5 times/week for 4weeks (n=7-9/group). Histomorphometry confirmed greater trabecular and periosteal bone formation and 3-point bending tests confirmed greater femoral strength in PTH-treated mice. Dual calcein labels were used to match bone regions by time-since-mineralisation (bone age) and composition was measured by sFTIRM in six 15μm 2 regions at increasing depth perpendicular to the most immature bone on the medial periosteal edge; this allowed in situ measurement of progressive changes in bone matrix during its maturation. The sFTIRM method was validated in vehicle-treated bones where the expected progressive increases in mineral:matrix ratio and collagen crosslink type ratio were detected with increasing bone maturity. We also observed a gradual increase in carbonate content that strongly correlated with an increase in longitudinal stretch of the collagen triple helix (amide I:amide II ratio). PTH treatment did not alter the progressive changes in any of these parameters from the periosteal edge through to the more mature bone. These data provide new information about how the bone matrix matures in situ and confirm that bone deposited during PTH treatment undergoes normal collagen maturation and normal mineral accrual. Copyright © 2016

  13. Bone graft extenders and substitutes in the thoracolumbar spine.

    Science.gov (United States)

    Arner, Justin W; Daffner, Scott D

    2012-05-01

    Autologous iliac crest bone graft remains the gold standard for lumbar fusion. The potential for complications has led to the development of alternative bone graft materials and enhancers, including autologous growth factors, demineralized bone matrix products, osteoinductive agents, and ceramic products. The current literature centers mainly on preclinical studies, which, further complicating the situation, evaluate these products in different clinical scenarios or surgical techniques. Autologous growth factors and demineralized bone matrix products have had promising results in preclinical studies, but few strong clinical studies have been conducted. Ceramic extenders were evaluated with other substances and had good but often inconsistent results. Bone morphogenetic proteins have been extensively studied and may have benefits as osteoinductive agents. Category comparisons are difficult to make, and there are differences even between products within the same category. The surgeon must be knowledgeable about products and their advantages, disadvantages, indications, contraindications, and possible applications so that they can make the best choice for each patient.

  14. Bone regeneration: in vitro evaluation of the behaviour of osteoblast-like MG63 cells placed in contact with polylactic-co-glycolic acid, deproteinized bovine bone and demineralized freeze-dried bone allograft.

    Science.gov (United States)

    Pappalardo, S; Mastrangelo, F; Reale Marroccia, D; Cappello, V; Ciampoli, C; Carlino, V; Tanteri, L; Costanzo, M; Sinatra, F; Tetè, S

    2008-01-01

    Insufficient bone density of the alveolar crests, caused by loss of the dental elements, sometimes impedes the primary stability of an integrated bone implant. The techniques of bone regeneration allow to obtain a sufficient quantity of alveolar bone to permit the implant rehabilitation of the edentulous crests. Today several grafting materials are available and they have different characteristics, according to their structure, which influence the different behaviour of the grafting materials to the bone and the implant surface. The aim of this study is to evaluate the interaction between a human osteosarcoma MG63 cell line and three different biomaterials: polylactic-co-glycolic acid (PLAGA), deproteinized bovine bone and demineralised freeze-dried bone allograft (DFDBA). From this study a different behaviour emerges of the osteoblast-like MG63 cells in relation to the sublayer on which these cells were placed in culture. The results of the study, in fact, demonstrate that the most osteoconductive material of the three analysed is the DFDBA, followed by DPBB. On the contrary, the PLGA, because of its roughness, does not seem to represent a valid support for cell growth, and does not encourage any morphologic modification in tumor cells. Furthermore, deproteinized bovine bone shows a differentiating effect which could lead to hypothesise an osteoconductive capacity of this biomaterial. Further studies should be carried out with the aim of explaining the results obtained.

  15. [Levels of bone mineral matrix organization and the mechanisms determining parameters of its formation].

    Science.gov (United States)

    Avrunin, A S; Tikhilov, R M; Abolin, A B; Shcherbak, I G

    2005-01-01

    Authors suggest to regard bone mineral matrix as the four-level structure. The first level is represented by an internal structure of a mineral, the second--by mineral morphological structure, the third--by coplanar association of minerals, and the fourth--by macroassociation of minerals in a single complex inside each bone. The most probable mechanisms determining stability of reproduction of mineral matrix parameters on each of these levels are shown. As a result of their functioning, the variants of bone mineral matrix structures are formed that are the programmed reflection of specificity of the given site of organic structures.

  16. Bone Quality: The Mechanical Effects of Microarchitecture and Matrix Properties

    NARCIS (Netherlands)

    J.S. Day (Judd)

    2005-01-01

    textabstractIn this body of work we have examined some of the current concepts pertaining to the relation between bone mass, bone quality and the mechanical properties of bone. In our first series of studies we used a model of human osteoarthritis to investigate the implications of changes in the

  17. A 3D printed nano bone matrix for characterization of breast cancer cell and osteoblast interactions

    Science.gov (United States)

    Zhu, Wei; Castro, Nathan J.; Cui, Haitao; Zhou, Xuan; Boualam, Benchaa; McGrane, Robert; Glazer, Robert I.; Zhang, Lijie Grace

    2016-08-01

    Bone metastasis is one of the most prevalent complications of late-stage breast cancer, in which the native bone matrix components, including osteoblasts, are intimately involved in tumor progression. The development of a successful in vitro model would greatly facilitate understanding the underlying mechanism of breast cancer bone invasion as well as provide a tool for effective discovery of novel therapeutic strategies. In the current study, we fabricated a series of in vitro bone matrices composed of a polyethylene glycol hydrogel and nanocrystalline hydroxyapatite of varying concentrations to mimic the native bone microenvironment for the investigation of breast cancer bone metastasis. A stereolithography-based three-dimensional (3D) printer was used to fabricate the bone matrices with precisely controlled architecture. The interaction between breast cancer cells and osteoblasts was investigated in the optimized bone matrix. Using a Transwell® system to separate the two cell lines, breast cancer cells inhibited osteoblast proliferation, while osteoblasts stimulated breast cancer cell growth, whereas, both cell lines increased IL-8 secretion. Breast cancer cells co-cultured with osteoblasts within the 3D bone matrix formed multi-cellular spheroids in comparison to two-dimensional monolayers. These findings validate the use of our 3D printed bone matrices as an in vitro metastasis model, and highlights their potential for investigating breast cancer bone metastasis.

  18. Bisphosphonate treatment affects trabecular bone apparent modulus through micro-architecture rather than matrix properties

    DEFF Research Database (Denmark)

    Ding, Ming

    2004-01-01

    and trabecular architecture independently. Conventional histomorphometry and microdamage data were obtained from the second and third lumbar vertebrae of the same dogs [Bone 28 (2001) 524]. Bisphosphonate treatment resulted in an increased apparent Young's modulus, decreased bone turnover, increased calcified...... matrix density, and increased microdamage. We could not detect any change in the effective Young's modulus of the calcified matrix in the bisphosphonate treated groups. The observed increase in apparent Young's modulus was due to increased bone mass and altered trabecular architecture rather than changes...... in the calcified matrix modulus. We hypothesize that the expected increase in the Young's modulus of the calcified matrix due to the increased calcified matrix density was counteracted by the accumulation of microdamage. Udgivelsesdato: 2004 May...

  19. The potential of mangosteen (Garcinia mangostana peel extract, combined with demineralized freeze-dried bovine bone xenograft, to reduce ridge resorption and alveolar bone regeneration in preserving the tooth extraction socket

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2017-01-01

    Conclusion: The induction of MPEs and DFBBX is effective in reducing inflammation, lowering osteoclasts, decreasing alveolar bone resorption, and also increasing BMP2 expression and alveolar bone regeneration.

  20. Function of Matrix IGF-1 in Coupling Bone Resorption and Formation

    Science.gov (United States)

    Crane, Janet L.; Cao, Xu

    2013-01-01

    Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space and time dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of MSCs and HSCs and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis. PMID:24068256

  1. Function of matrix IGF-1 in coupling bone resorption and formation.

    Science.gov (United States)

    Crane, Janet L; Cao, Xu

    2014-02-01

    Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore, understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space- and time-dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of mesenchymal stem cells and hematopoietic stem cells and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis.

  2. Response of induced bone defects in horses to collagen matrix containing the human parathyroid hormone gene.

    Science.gov (United States)

    Backstrom, Kristin C; Bertone, Alicia L; Wisner, Erik R; Weisbrode, Stephen E

    2004-09-01

    To determine whether human parathyroid hormone (hPTH) gene in collagen matrix could safely promote bone formation in diaphyseal or subchondral bones of horses. 8 clinically normal adult horses. Amount, rate, and quality of bone healing for 13 weeks were determined by use of radiography, quantitative computed tomography, and histomorphometric analysis. Diaphyseal cortex and subchondral bone defects of metacarpi were filled with hPTH(1-34) gene-activated matrix (GAM) or remained untreated. Joints were assessed on the basis of circumference, synovial fluid analysis, pain on flexion, lameness, and gross and histologic examination. Bone volume index was greater for cortical defects treated with hPTH(1-34) GAM, compared with untreated defects. Bone production in cortical defects treated with hPTH(1-34) GAM positively correlated with native bone formation in untreated defects. In contrast, less bone was detected in hPTH(1-34) GAM-treated subchondral bone defects, compared with untreated defects, and histology confirmed poorer healing and residual collagen sponge. Use of hPTH(1-34) GAM induced greater total bone, specifically periosteal bone, after 13 weeks of healing in cortical defects of horses. The hPTH(1-34) GAM impeded healing of subchondral bone but was biocompatible with joint tissues. Promotion of periosteal bone formation may be beneficial for healing of cortical fractures in horses, but the delay in onset of bone formation may negate benefits. The hPTH(1-34) GAM used in this study should not be placed in articular subchondral bone defects, but contact with articular surfaces is unlikely to cause short-term adverse effects.

  3. Management strategy for unicameral bone cyst.

    Science.gov (United States)

    Chuo, Chin-Yi; Fu, Yin-Chih; Chien, Song-Hsiung; Lin, Gau-Tyan; Wang, Gwo-Jaw

    2003-06-01

    The management of a unicameral bone cyst varies from percutaneous needle biopsy, aspiration, and local injection of steroid, autogenous bone marrow, or demineralized bone matrix to the more invasive surgical procedures of conventional curettage and grafting (with autogenous or allogenous bone) or subtotal resection with bone grafting. The best treatment for a unicameral bone cyst is yet to be identified. Better understanding of the pathology will change the concept of management. The aim of treatment is to prevent pathologic fracture, to promote cyst healing, and to avoid cyst recurrence and re-fracture. We retrospectively reviewed 17 cases of unicameral bone cysts (12 in the humerus, 3 in the femur, 2 in the fibula) managed by conservative observation, curettage and bone grafting with open reduction and internal fixation, or continuous decompression and drainage with a cannulated screw. We suggest percutaneous cannulated screw insertion to promote cyst healing and prevent pathologic fracture. We devised a protocol for the management of unicameral bone cysts.

  4. Insulin-like growth factor I has independent effects on bone matrix formation and cell replication

    International Nuclear Information System (INIS)

    Hock, J.M.; Centrella, M.; Canalis, E.

    1988-01-01

    The effects of insulin-like growth factor-I (IGF-I) and insulin on bone matrix synthesis and bone cell replication were studied in cultured 21-day-old fetal rat calvariae. Histomorphometry techniques were developed to measure the incorporation of [2,3- 3 H]proline and [methyl- 3 H]thymidine into bone matrix and bone cell nuclei, respectively, using autoradiographs of sagittal sections of calvariae cultured with IGF-I, insulin, or vehicle for up to 96 h. To confirm an effect on bone formation, IGF-I was also studied for its effects on [ 3 H]proline incorporation into collagenase-digestible protein (CDP) and noncollagen protein and on [ 3 H]thymidine incorporation into acid-precipitable material (DNA). IGF-I at 10(-9)-10(-7) M significantly increased the rate of bone matrix apposition and CDP after 24 h by 45-50% and increased cell labeling by 8-fold in the osteoprogenitor cell zone, by 4-fold in the osteoblast cell zone, and by 2-fold in the periosteal fibroblast zone. Insulin at 10(-9)-10(-6) M also increased matrix apposition rate and CDP by 40-50%, but increased cell labeling by 2-fold only at a concentration of 10(-7) M or higher and then only in the osteoprogenitor cell zone. When hydroxyurea was added to IGF-I-treated bones, the effects of IGF-I on DNA synthesis were abolished, but the increase in bone matrix apposition induced by IGF-I was only partly diminished. In conclusion, IGF-I stimulates matrix synthesis in calvariae, an effect that is partly, although not completely, dependent on its stimulatory effect on DNA synthesis

  5. The sintered microsphere matrix for bone tissue engineering: in vitro osteoconductivity studies.

    Science.gov (United States)

    Borden, Mark; Attawia, Mohamed; Laurencin, Cato T

    2002-09-05

    A tissue engineering approach has been used to design three-dimensional synthetic matrices for bone repair. The osteoconductivity and degradation profile of a novel polymeric bone-graft substitute was evaluated in an in vitro setting. Using the copolymer poly(lactide-co-glycolide) [PLAGA], a sintering technique based on microsphere technology was used to fabricate three-dimensional porous scaffolds for bone regeneration. Osteoblasts and fibroblasts were seeded onto a 50:50 PLAGA scaffold. Morphologic evaluation through scanning electron microscopy demonstrated that both cell types attached and spread over the scaffold. Cells migrated through the matrix using cytoplasmic extensions to bridge the structure. Cross-sectional images indicated that cellular proliferation had penetrated into the matrix approximately 700 microm from the surface. Examination of the surfaces of cell/matrix constructs demonstrated that cellular proliferation had encompassed the pores of the matrix by 14 days of cell culture. With the aim of optimizing polymer composition and polymer molecular weight, a degradation study was conducted utilizing the matrix. The results demonstrate that degradation of the sintered matrix is dependent on molecular weight, copolymer ratio, and pore volume. From this data, it was determined that 75:25 PLAGA with an initial molecular weight of 100,000 has an optimal degradation profile. These studies show that the sintered microsphere matrix has an osteoconductive structure capable of functioning as a cellular scaffold with a degradation profile suitable for bone regeneration. Copyright 2002 Wiley Periodicals, Inc.

  6. Extracellular matrix scaffolds for cartilage and bone regeneration

    NARCIS (Netherlands)

    Benders, K.E.M.; van Weeren, P.R.; Badylak, S.F.; Saris, Daniël B.F.; Dhert, W.J.A.; Malda, J.

    2013-01-01

    Regenerative medicine approaches based on decellularized extracellular matrix (ECM) scaffolds and tissues are rapidly expanding. The rationale for using ECM as a natural biomaterial is the presence of bioactive molecules that drive tissue homeostasis and regeneration. Moreover, appropriately

  7. THE MEASUREMENT OF BONE QUALITY USING GRAY LEVEL CO-OCCURRENCE MATRIX TEXTURAL FEATURES.

    Science.gov (United States)

    Shirvaikar, Mukul; Huang, Ning; Dong, Xuanliang Neil

    2016-10-01

    In this paper, statistical methods for the estimation of bone quality to predict the risk of fracture are reported. Bone mineral density and bone architecture properties are the main contributors of bone quality. Dual-energy X-ray Absorptiometry (DXA) is the traditional clinical measurement technique for bone mineral density, but does not include architectural information to enhance the prediction of bone fragility. Other modalities are not practical due to cost and access considerations. This study investigates statistical parameters based on the Gray Level Co-occurrence Matrix (GLCM) extracted from two-dimensional projection images and explores links with architectural properties and bone mechanics. Data analysis was conducted on Micro-CT images of 13 trabecular bones (with an in-plane spatial resolution of about 50μm). Ground truth data for bone volume fraction (BV/TV), bone strength and modulus were available based on complex 3D analysis and mechanical tests. Correlation between the statistical parameters and biomechanical test results was studied using regression analysis. The results showed Cluster-Shade was strongly correlated with the microarchitecture of the trabecular bone and related to mechanical properties. Once the principle thesis of utilizing second-order statistics is established, it can be extended to other modalities, providing cost and convenience advantages for patients and doctors.

  8. Effect of platelet-rich plasma combined with demineralised bone matrix on bone healing in rabbit ulnar defects.

    Science.gov (United States)

    Galanis, Vasilios; Fiska, Alice; Kapetanakis, Stylianos; Kazakos, Konstantinos; Demetriou, Thespis

    2017-09-01

    This study evaluates the effect of autologous platelet-rich plasma (PRP) combined with xenogeneic demineralised bone matrix (DBM) on bone healing of critical-size ulnar defects (2-2.5 times the ulnar diameter) in New Zealand White rabbits. Critical-size defects were created unilaterally in the ulna of 36 rabbits, while keeping the contralateral limb intact. They were divided into three groups. In Group A, the defect was filled with autologous PRP and in Group B, with autologous PRP combined with DBM; in Group C, the defect remained empty. The rabbits were euthanised 12 weeks postoperatively. Radiological, biomechanical and histological assessments were carried out and statistical analysis of the results was performed. Group B had significantly higher radiological and histological scores than Groups A and C. Defects in Group B showed significant new bone formation, whereas there was minimal or no new bone formation in Groups A and C. Only specimens in Group B showed macroscopic bone union. Biomechanical evaluation of the treated and intact contralateral limbs in Group B showed significant differences. In this study, statistically significant enhancement of bone healing was found in critical-size defects treated with PRP and DBM, as shown by radiological findings, gross assessment, and biomechanical and histopathological results. Defects in the two other groups remained unbridged. Therefore, PRP was effective only when it was used in combination with a bone graft. Copyright: © Singapore Medical Association

  9. Nanoporous Structure of Bone Matrix at Osteoporosis from Data of Atomic Force Microscopy and IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    A. A. Gaidash

    2011-01-01

    Full Text Available It was found that in an osteoporotic bone the fraction of nanosized pores decreases, the mineral phase amorphizes, hydrated shells around mineralized particles of the bone matrix thicken, and adhesion forces increase. This contributes to the formation of water clusters similar to bulk water clusters compared to the healthy bone tissue and leads to the accumulation of more viscous liquid with increased intermolecular interaction forces in the pores of the bone matrix. Given this, the rates of chemical reactions proceeding in the water phase of ultrathin channels of general parts of collagen fibrils decrease. Ultimately, nanopores of collagen-apatite interfaces lose, to a certain extent, the capability of catalyzing the hydroxyapatite crystallization.

  10. Human Bone Matrix Changes During Deep Saturation Dives

    Science.gov (United States)

    2008-08-08

    urine concentrations of Ntx have been demonstrated in bone diseases such as osteoporosis, primary hyperthyroidism , and Paget’s disease. Also... loss in divers, and that the differentials likely came from the gas- induced osmosis model.30 4 The same facility was used for both dives and...Other demographic data such as age, height, weight , and diving experience were also collected for later correlational analyses. The dive took place

  11. Matrix change of bone grafting substitute after implantation into guinea pig bulla.

    Science.gov (United States)

    Punke, Ch; Zehlicke, T; Just, T; Holzhüter, G; Gerber, T; Pau, H W

    2012-05-01

    Many different surgical techniques have been developed to remove open mastoid cavities. In addition to autologous materials, alloplastic substances have been used. A very slow absorption of these materials and extrusion reactions have been reported. We investigated a newly developed, highly porous bone grafting material to eliminate open mastoid cavities, in an animal model. To characterise the transformation process, the early tissue reactions were studied in relation to the matrix transformation of the bone material. NanoBone (NB), a highly porous bone grafting material based on calcium phosphate and silica, was filled into the open bullae from 20 guinea pigs. The bullae were examined histologically. Energy dispersive X-ray spectroscopy (EDX) was used to investigate the change in the elemental composition at different sampling times. The surface topography of the sections was examined by electron microscopy. After 1 week, periodic acid-Schiffs (PAS) staining demonstrated accumulation of glycogen and proteins, particularly in the border area of the NB particles. After 2 weeks, the particles were evenly coloured after PAS staining. EDX analysis showed a rapid absorption of the silica in the bone grafting material. NanoBone showed a rapid matrix change after implantation in the bullae of guinea pigs. The absorption of the silica matrix and replacement by PAS-positive substances like glycoproteins and mucopolysaccharides seems to play a decisive role in the degradation processes of NB. This is associated with the good osteoinductive properties of the material.

  12. Ultra-structural defects cause low bone matrix stiffness despite high mineralization in osteogenesis imperfecta mice.

    Science.gov (United States)

    Vanleene, Maximilien; Porter, Alexandra; Guillot, Pascale-Valerie; Boyde, Alan; Oyen, Michelle; Shefelbine, Sandra

    2012-06-01

    Bone is a complex material with a hierarchical multi-scale organization from the molecule to the organ scale. The genetic bone disease, osteogenesis imperfecta, is primarily caused by mutations in the collagen type I genes, resulting in bone fragility. Because the basis of the disease is molecular with ramifications at the whole bone level, it provides a platform for investigating the relationship between structure, composition, and mechanics throughout the hierarchy. Prior studies have individually shown that OI leads to: 1. increased bone mineralization, 2. decreased elastic modulus, and 3. smaller apatite crystal size. However, these have not been studied together and the mechanism for how mineral structure influences tissue mechanics has not been identified. This lack of understanding inhibits the development of more accurate models and therapies. To address this research gap, we used a mouse model of the disease (oim) to measure these outcomes together in order to propose an underlying mechanism for the changes in properties. Our main finding was that despite increased mineralization, oim bones have lower stiffness that may result from the poorly organized mineral matrix with significantly smaller, highly packed and disoriented apatite crystals. Using a composite framework, we interpret the lower oim bone matrix elasticity observed as the result of a change in the aspect ratio of apatite crystals and a disruption of the crystal connectivity. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Densitometric analysis of the autogenous demineralized dentin matrix on the dental socket wound healing process in humans Análise densitométrica da matriz dentinária desmineralizada autógena na reparação alveolar de humanos

    Directory of Open Access Journals (Sweden)

    Mônica Fernandes Gomes

    2006-12-01

    Full Text Available The aim of this study was to evaluate the effects of the autogenous demineralized dentin matrix (ADDM on the third molar socket wound healing process in humans, using the guided bone regeneration technique and a polytetrafluoroethylene barrier (PTFE. Twenty-seven dental sockets were divided into three groups: dental socket (Control, dental socket with PTFE barrier (PTFE, and dental socket with ADDM slices associated to PTFE barrier (ADDM + PTFE. The dental sockets were submitted to radiographic bone densitometry analysis and statistical analysis on the 15th, 30th, 60th and 90th days using analysis of variance (ANOVA and Tukey's test (p £ 0.05. The radiographic analysis of the ADDM + PTFE group showed greater homogeneity of bone radiopacity than the Control group and the PTFE group, during all the observation times. The dentin matrix gradually disappeared from the dental socket during the course of the repair process, suggesting its resorption during the bone remodeling process. It was concluded that the radiographic bone density of the dental sockets treated with ADDM was similar to that of the surrounding normal bone on the 90th day. The ADDM was biocompatible with the bone tissue of the surgical wounds of human dental sockets. The radiographic analysis revealed that the repair process was discreetly faster in the ADDM + PTFE group than in the Control and PTFE groups, although the difference was not statistically significant. In addition, the radiographic image of the ADDM + PTFE group suggested that its bone architecture was better than that of the Control and PFTE groups.O objetivo desta pesquisa foi avaliar a reparação óssea em alvéolos dentários após exodontia dos terceiros molares inferiores em humanos, com implantação de matriz dentinária desmineralizada autógena (MDDA na cavidade e cobertura desta com barreira de politetrafluoretileno (PTFE. Foram selecionados 27 dentes, os quais foram divididos em três grupos: alvéolo dent

  14. [Experiment of porous calcium phosphate/bone matrix gelatin composite cement for repairing lumbar vertebral bone defect in rabbit].

    Science.gov (United States)

    Wang, Song; Yang, Han; Yang, Jian; Kang, Jianping; Wang, Qing; Song, Yueming

    2017-12-01

    To investigate the effect of a porous calcium phosphate/bone matrix gelatin (BMG) composite cement (hereinafter referred to as the "porous composite cement") for repairing lumbar vertebral bone defect in a rabbit model. BMG was extracted from adult New Zealand rabbits according to the Urist's method. Poly (lactic-co-glycolic) acid (PLGA) microsphere was prepared by W/O/W double emulsion method. The porous composite cement was developed by using calcium phosphate cement (CPC) composited with BMG and PLGA microsphere. The physicochemical characterizations of the porous composite cement were assessed by anti-washout property, porosity, and biomechanical experiment, also compared with the CPC. Thirty 2-month-old New Zealand rabbits were used to construct vertebral bone defect at L 3 in size of 4 mm×3 mm×3 mm. Then, the bone defect was repaired with porous composite cement (experimental group, n =15) or CPC (control group, n =15). At 4, 8, and 12 weeks after implantation, each bone specimen was assessed by X-ray films for bone fusion, micro-CT for bone mineral density (BMD), bone volume fraction (BVF), trabecular thickness (Tb. Th.), trabecular number (Tb.N.), and trabecular spacing (Tb. Sp.), and histological section with toluidine blue staining for new-born bone formation. The study demonstrated well anti-washout property in 2 groups. The porous composite cement has 55.06%±1.18% of porosity and (51.63±6.73) MPa of compressive strength. The CPC has 49.38%±1.75% of porosity and (63.34±3.27) MPa of compressive strength. There were significant differences in porosity and compressive strength between different cements ( t =4.254, P =0.006; t =2.476, P =0.034). X-ray films revealed that the zone between the cement and host bone gradually blurred with the time extending. At 12 weeks after implantation, the zone was disappeared in the experimental group, but clear in the control group. There were significant differences in BMD, BVF, Tb. Th., Tb. N., and Tb. Sp. between

  15. Aluminum and bone: Review of new clinical circumstances associated with Al(3+) deposition in the calcified matrix of bone.

    Science.gov (United States)

    Chappard, D; Bizot, P; Mabilleau, G; Hubert, L

    2016-06-01

    Several decades ago, aluminum encephalopathy associated with osteomalacia has been recognized as the major complication of chronic renal failure in dialyzed patients. Removal of aluminum from the dialysate has led to a disappearance of the disease. However, aluminum deposit occurs in the hydroxyapatite of the bone matrix in some clinical circumstances that are presented in this review. We have encountered aluminum in bone in patients with an increased intestinal permeability (coeliac disease), or in the case of prolonged administration of aluminum anti-acid drugs. A colocalisation of aluminum with iron was also noted in cases of hemochromatosis and sickle cell anemia. Aluminium was also identified in a series of patients with exostosis, a frequent benign bone tumor. Corrosion of prosthetic implants composed of grade V titanium (TA6V is an alloy containing 6% aluminum and 4% vanadium) was also observed in a series of hip or knee revisions. Aluminum can be identified in undecalcified bone matrix stained by solochrome azurine, a highly specific stain allowing the detection of 0.03 atomic %. Colocalization of aluminum and iron does not seem to be the fruit of chance but the cellular and molecular mechanisms are still poorly understood. Histochemistry is superior to spectroscopic analyses (EDS and WDS in scanning electron microscopy). Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. [Fabrication of porous poly lactic acid-bone matrix gelatin composite bioactive material and its osteoinductive activity].

    Science.gov (United States)

    Zhang, Yumin; Li, Baoxing; Li, Ji

    2007-02-01

    To fabricate a novel porous bioactive composite biomaterial consisting of poly lactic acid (PLA)-bone matrix gelatin (BMG) by using the supercritical carbon dioxide fluid technique (SC-CO2) and to evaluate its osteoinductive activity. The cortical bones selected from healthy adult donors were processed into BMG by the defatting, demineralizing, and deproteinizing processes. PLA and BMG were mixed at a volume radio of 3 : 1; then, the PLA-BMG mixed material and the pure PLA material were respectively placed in the supercritical carbon dioxide reaction kettles, and were respectively added by the NaCl particles 100-200 microm in diameter for the porosity of the materials so that the porous PLA-BMG composite material and the porous PLA composite material could be formed. The mouse osteoblast-like MC3T3-E1 cells were cultured in the dulbecco's modified eagle medium (DMEM) supplemented with 10% fetal bovine serum. Then, 20 microl of the MC3T3-E1 cell suspensions containing 2 X 10(6) cells /ml were delivered into the culturing plate (24 wells/plate) made of the different materials, which were co-cultured for 2 weeks. In the PLA-BMG group, 100 microg of the crushed PLA-BMG material was contained in each well; in the PLA group, 100 microg of the crushed PLA material was contained in each well; and in the DMEM group, only DMEM was contained, which served as the control group. There were 6 wells in each group. The quantitative analysis on the calcification area was performed by the staining of the alizarin red S. The co-cultured cells were harvested and lysated in 1 ml of 0. 2% Nonidet P-40 by the ultrasonic lysating technique. Then, the ALP activity and the Ca content were measured according to the illuminations of the reagent kits. The porous PLA-BMG composite material showed a good homological porosity with a pore diameter of 50-150 microm and a good connectivity between the pores. The ALP activity, the Ca content, and the calcification area were significantly greater in

  17. The available evidence on demineralised bone matrix in trauma and orthopaedic surgery

    NARCIS (Netherlands)

    J. van der Stok (Johan); Hartholt, K.A.; Schoenmakers, D.A.L.; J.J. Arts (Jacobus J.)

    2017-01-01

    textabstractObjectives: The aim of this systematic literature review was to assess the clinical level of evidence of commercially available demineralised bone matrix (DBM) products for their use in trauma and orthopaedic related surgery. Methods: A total of 17 DBM products were used as search terms

  18. The available evidence on demineralised bone matrix in trauma and orthopaedic surgery : a systematic review

    NARCIS (Netherlands)

    van der Stok, J.; Hartholt, K.A.; Schoenmakers, D.A.L.; Arts, J.J.C.

    2017-01-01

    Objectives: The aim of this systematic literature review was to assess the clinical level of evidence of commercially available demineralised bone matrix (DBM) products for their use in trauma and orthopaedic related surgery. Methods: A total of 17 DBM products were used as search terms in two

  19. Two types of mineral-related matrix vesicles in the bone mineralization of zebrafish

    International Nuclear Information System (INIS)

    Yang, L; Zhang, Y; Cui, F Z

    2007-01-01

    Two types of mineral-related matrix vesicle, multivesicular body (MVB) and monovesicle, were detected in the skeletal bone of zebrafish. Transmission electron microscopy and energy dispersive spectroscopy (EDS) analyses of the vesicular inclusions reveal that both types of vesicles contain calcium and phosphorus, suggesting that these vesicles may be involved in mineral ion delivery for the bone mineralization of zebrafish. However, their size and substructure are quite different. Monovesicles, whose diameter ranges from 100 nm to 550 nm, are similar to the previously reported normal matrix vesicles, while MVBs have a larger size of 700-1000 nm in nominal diameter and possess a substructure that is composed of smaller vesicles with their average size around 100 nm. The presence of mineral-related MVBs, which is first identified in zebrafish bone, indicates that the mineralization-associated transportation process of mineral ions is more complicated than is ordinarily imagined

  20. Castor oil polymer induces bone formation with high matrix metalloproteinase-2 expression.

    Science.gov (United States)

    Saran, Wallace Rocha; Chierice, Gilberto Orivaldo; da Silva, Raquel Assed Bezerra; de Queiroz, Alexandra Mussolino; Paula-Silva, Francisco Wanderley Garcia; da Silva, Léa Assed Bezerra

    2014-02-01

    The aim of this study was to evaluate the modulation of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) expression in newly formed bone tissue at the interface between implants derived from castor oil (Ricinus communis) polymer and the tibia medullary canal. Forty-four rabbits were assigned to either Group 1 (n = 12; control) or Group 2 (n = 30), which had the tibial medullary canals reamed bilaterally and filled with polymer. CT scans showed no space between the material surface and the bone at the implant/bone marrow interface, and the density of the tissues at this interface was similar to the density measured of other regions of the bone. At 90 days postimplantation, the interface with the polymer presented a thick layer of newly formed bone tissue rich in osteocytes. This tissue exhibited ongoing maturation at 120 and 150 days postimplantation. Overall, bone remodeling process was accompanied by positive modulation of MMP-2 and low MMP-9 expression. Differently, in control group, the internal surface close to the medullary canal was lined by osteoblasts, followed by a bone tissue zone with few lacunae filled with osteocytes. Maturation of the tissue of the medullary internal surface occurred in the inner region, with the bone being nonlamellar. © 2013 Wiley Periodicals, Inc.

  1. Changes in chemical composition of bone matrix in ovariectomized (OVX) rats detected by Raman spectroscopy and multivariate analysis

    Science.gov (United States)

    Oshima, Yusuke; Iimura, Tadahiro; Saitou, Takashi; Imamura, Takeshi

    2015-02-01

    Osteoporosis is a major bone disease that connotes the risk of fragility fractures resulting from alterations to bone quantity and/or quality to mechanical competence. Bone strength arises from both bone quantity and quality. Assessment of bone quality and bone quantity is important for prediction of fracture risk. In spite of the two factors contribute to maintain the bone strength, only one factor, bone mineral density is used to determine the bone strength in the current diagnosis of osteoporosis. On the other hand, there is no practical method to measure chemical composition of bone tissue including hydroxyapatite and collagen non-invasively. Raman spectroscopy is a powerful technique to analyze chemical composition and material properties of bone matrix non-invasively. Here we demonstrated Raman spectroscopic analysis of the bone matrix in osteoporosis model rat. Ovariectomized (OVX) rat was made and the decalcified sections of tibias were analyzed by a Raman microscope. In the results, Raman bands of typical collagen appeared in the obtained spectra. Although the typical mineral bands at 960 cm-1 (Phosphate) was absent due to decalcified processing, we found that Raman peak intensities of amide I and C-C stretching bands were significantly different between OVX and sham-operated specimens. These differences on the Raman spectra were statistically compared by multivariate analyses, principal component analysis (PCA) and liner discrimination analysis (LDA). Our analyses suggest that amide I and C-C stretching bands can be related to stability of bone matrix which reflects bone quality.

  2. Quantitative mapping of matrix content and distribution across the ligament-to-bone insertion.

    Directory of Open Access Journals (Sweden)

    Jeffrey P Spalazzi

    Full Text Available The interface between bone and connective tissues such as the Anterior Cruciate Ligament (ACL constitutes a complex transition traversing multiple tissue regions, including non-calcified and calcified fibrocartilage, which integrates and enables load transfer between otherwise structurally and functionally distinct tissue types. The objective of this study was to investigate region-dependent changes in collagen, proteoglycan and mineral distribution, as well as collagen orientation, across the ligament-to-bone insertion site using Fourier transform infrared spectroscopic imaging (FTIR-I. Insertion site-related differences in matrix content were also evaluated by comparing tibial and femoral entheses. Both region- and site-related changes were observed. Collagen content was higher in the ligament and bone regions, while decreasing across the fibrocartilage interface. Moreover, interfacial collagen fibrils were aligned parallel to the ligament-bone interface near the ligament region, assuming a more random orientation through the bulk of the interface. Proteoglycan content was uniform on average across the insertion, while its distribution was relatively less variable at the tibial compared to the femoral insertion. Mineral was only detected in the calcified interface region, and its content increased exponentially across the mineralized fibrocartilage region toward bone. In addition to new insights into matrix composition and organization across the complex multi-tissue junction, findings from this study provide critical benchmarks for the regeneration of soft tissue-to-bone interfaces and integrative soft tissue repair.

  3. Quantitative Mapping of Matrix Content and Distribution across the Ligament-to-Bone Insertion

    Science.gov (United States)

    Spalazzi, Jeffrey P.; Boskey, Adele L.; Pleshko, Nancy; Lu, Helen H.

    2013-01-01

    The interface between bone and connective tissues such as the Anterior Cruciate Ligament (ACL) constitutes a complex transition traversing multiple tissue regions, including non-calcified and calcified fibrocartilage, which integrates and enables load transfer between otherwise structurally and functionally distinct tissue types. The objective of this study was to investigate region-dependent changes in collagen, proteoglycan and mineral distribution, as well as collagen orientation, across the ligament-to-bone insertion site using Fourier transform infrared spectroscopic imaging (FTIR-I). Insertion site-related differences in matrix content were also evaluated by comparing tibial and femoral entheses. Both region- and site-related changes were observed. Collagen content was higher in the ligament and bone regions, while decreasing across the fibrocartilage interface. Moreover, interfacial collagen fibrils were aligned parallel to the ligament-bone interface near the ligament region, assuming a more random orientation through the bulk of the interface. Proteoglycan content was uniform on average across the insertion, while its distribution was relatively less variable at the tibial compared to the femoral insertion. Mineral was only detected in the calcified interface region, and its content increased exponentially across the mineralized fibrocartilage region toward bone. In addition to new insights into matrix composition and organization across the complex multi-tissue junction, findings from this study provide critical benchmarks for the regeneration of soft tissue-to-bone interfaces and integrative soft tissue repair. PMID:24019964

  4. Early matrix change of a nanostructured bone grafting substitute in the rat.

    Science.gov (United States)

    Xu, Weiguo; Holzhüter, Gerd; Sorg, Heiko; Wolter, Daniel; Lenz, Solvig; Gerber, Thomas; Vollmar, Brigitte

    2009-11-01

    A nanocrystalline bone substitute embedded in a highly porous silica gel matrix (NanoBone) has previously been shown to bridge bone defects by an organic matrix. As the initial host response on the bone graft substitute might be a determinant for subsequent bone formation, our present purpose was to characterize the early tissue reaction on this biomaterial. After implantation of 80 mg of NanoBone into the adipose neck tissue of a total of 35 rats, grafts were harvested for subsequent analysis at days 3, 6, 9, 12, and 21. The biomaterial was found encapsulated by granulation tissue which partly penetrated the implant at day 3 and completely pervaded the graft at day 12 on implantation. Histology revealed tartrate-resistant acid phosphatase (TRAP)-positive giant cells covering the biomaterial. ED1 (CD68) immunopositivity of these cells further indicated their osteoclast-like phenotype. Scanning electron microscopy revealed organic tissue components within the periphery of the graft already at day 9, whereas the central hematoma region still presented the silica-surface of the biomaterial. Energy dispersive X-ray spectroscopy further demonstrated that the silica gel was degraded faster in the peripheral granulation tissue than in the central hematoma and was replaced by organic host components by day 12. In conclusion, the silica gel matrix is rapidly replaced by carbohydrate macromolecules. This might represent a key step in the process of graft degradation on its way toward induction of bone formation. The unique composition and structure of this nanoscaled biomaterial seem to support its degradation by host osteoclast-like giant cells.

  5. Regulation of extracellular matrix vesicles via rapid responses to steroid hormones during endochondral bone formation.

    Science.gov (United States)

    Asmussen, Niels; Lin, Zhao; McClure, Michael J; Schwartz, Zvi; Boyan, Barbara D

    2017-12-09

    Endochondral bone formation is a precise and highly ordered process whose exact regulatory framework is still being elucidated. Multiple regulatory pathways are known to be involved. In some cases, regulation impacts gene expression, resulting in changes in chondrocyte phenotypic expression and extracellular matrix synthesis. Rapid regulatory mechanisms are also involved, resulting in release of enzymes, factors and micro RNAs stored in extracellular matrisomes called matrix vesicles. Vitamin D metabolites modulate endochondral development via both genomic and rapid membrane-associated signaling pathways. 1α,25-dihydroxyvitamin D3 [1α,25(OH) 2 D 3 ] acts through the vitamin D receptor (VDR) and a membrane associated receptor, protein disulfide isomerase A3 (PDIA3). 24R,25-dihydroxyvitamin D3 [24R,25(OH) 2 D 3 ] affects primarily chondrocytes in the resting zone (RC) of the growth plate, whereas 1α,25(OH) 2 D 3 affects cells in the prehypertrophic and upper hypertrophic cell zones (GC). This includes genomically directing the cells to produce matrix vesicles with zone specific characteristics. In addition, vitamin D metabolites produced by the cells interact directly with the matrix vesicle membrane via rapid signal transduction pathways, modulating their activity in the matrix. The matrix vesicle payload is able to rapidly impact the extracellular matrix via matrix processing enzymes as well as providing a feedback mechanism to the cells themselves via the contained micro RNAs. Copyright © 2017. Published by Elsevier Inc.

  6. Bioactive glass-ceramic bone repair associated or not with autogenous bone: a study of organic bone matrix organization in a rabbit critical-sized calvarial model.

    Science.gov (United States)

    Biguetti, Claudia Cristina; Cavalla, Franco; Tim, Carla Roberta; Saraiva, Patrícia Pinto; Orcini, Wilson; De Andrade Holgado, Leandro; Rennó, Ana Claudia Muniz; Matsumoto, Mariza Akemi

    2018-04-26

    The aim of the study was to analyze bone matrix (BMX) organization after bone grafting and repair using a new bioactive glass-ceramic (Biosilicate ® ) associated or not with particulate autogenous bone graft. Thirty rabbits underwent surgical bilateral parietal defects and divided into groups according to the materials used: (C) control-blood clot, (BG) particulate autogenous bone, (BS) bioactive glass-ceramic, and BG + BS. After 7, 14, and 30 days post-surgery, a fragment of each specimen was fixed in - 80 °C liquid nitrogen for zymographic evaluation, while the remaining was fixed in 10% formalin for histological birefringence analysis. The results of this study demonstrated that matrix organization in experimental groups was significantly improved compared to C considering collagenous organization. Zymographic analysis revealed pro-MMP-2, pro-MMP-9, and active (a)-MMP-2 in all groups, showing gradual decrease of total gelatinolytic activity during the periods. At day 7, BG presented more prominent gelatinolytic activity for pro-MMP-2 and 9 and a-MMP-2, when compared to the other groups. In addition, at day 7, a 53% activation ratio (active form/[active form + latent form]) was evident in C group, 33% in BS group, and 31% in BG group. In general, BS allowed the production of a BMX similar to BG, with organized collagen deposition and MMP-2 and MMP-9 disponibility, permitting satisfactory bone remodeling at the late period. The evaluation of new bone substitute, with favorable biological properties, opens the possibility for its use as a viable and efficient alternative to autologous bone graft.

  7. Tendon Reattachment to Bone in an Ovine Tendon Defect Model of Retraction Using Allogenic and Xenogenic Demineralised Bone Matrix Incorporated with Mesenchymal Stem Cells.

    Directory of Open Access Journals (Sweden)

    Tanujan Thangarajah

    Full Text Available Tendon-bone healing following rotator cuff repairs is mainly impaired by poor tissue quality. Demineralised bone matrix promotes healing of the tendon-bone interface but its role in the treatment of tendon tears with retraction has not been investigated. We hypothesized that cortical demineralised bone matrix used with minimally manipulated mesenchymal stem cells will result in improved function and restoration of the tendon-bone interface with no difference between xenogenic and allogenic scaffolds.In an ovine model, the patellar tendon was detached from the tibial tuberosity and a complete distal tendon transverse defect measuring 1 cm was created. Suture anchors were used to reattach the tendon and xenogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5, or allogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5 were used to bridge the defect. Graft incorporation into the tendon and its effect on regeneration of the enthesis was assessed using histomorphometry. Force plate analysis was used to assess functional recovery.Compared to the xenograft, the allograft was associated with significantly higher functional weight bearing at 6 (P = 0.047, 9 (P = 0.028, and 12 weeks (P = 0.009. In the allogenic group this was accompanied by greater remodeling of the demineralised bone matrix into tendon-like tissue in the region of the defect (p = 0.015, and a more direct type of enthesis characterized by significantly more fibrocartilage (p = 0.039. No failures of tendon-bone healing were noted in either group.Demineralised bone matrix used with minimally manipulated mesenchymal stem cells promotes healing of the tendon-bone interface in an ovine model of acute tendon retraction, with superior mechanical and histological results associated with use of an allograft.

  8. Minimally invasive esthetic ridge preservation with growth-factor enhanced bone matrix.

    Science.gov (United States)

    Nevins, Marc L; Said, Sherif

    2017-12-28

    Extraction socket preservation procedures are critical to successful esthetic implant therapy. Conventional surgical approaches are technique sensitive and often result in alteration of the soft tissue architecture, which then requires additional corrective surgical procedures. This case series report presents the ability of flapless surgical techniques combined with a growth factor-enhanced bone matrix to provide esthetic ridge preservation at the time of extraction for compromised sockets. When considering esthetic dental implant therapy, preservation, or further enhancement of the available tissue support at the time of tooth extraction may provide an improved esthetic outcome with reduced postoperative sequelae and decreased treatment duration. Advances in minimally invasive surgical techniques combined with recombinant growth factor technology offer an alternative for bone reconstruction while maintaining the gingival architecture for enhanced esthetic outcome. The combination of freeze-dried bone allograft (FDBA) and rhPDGF-BB (platelet-derived growth factor-BB) provides a growth-factor enhanced matrix to induce bone and soft tissue healing. The use of a growth-factor enhanced matrix is an option for minimally invasive ridge preservation procedures for sites with advanced bone loss. Further studies including randomized clinical trials are needed to better understand the extent and limits of these procedures. The use of minimally invasive techniques with growth factors for esthetic ridge preservation reduces patient morbidity associated with more invasive approaches and increases the predictability for enhanced patient outcomes. By reducing the need for autogenous bone grafts the use of this technology is favorable for patient acceptance and ease of treatment process for esthetic dental implant therapy. © 2017 Wiley Periodicals, Inc.

  9. Analysing the bioactive makeup of demineralised dentine matrix on bone marrow mesenchymal stem cells for enhanced bone repair.

    Science.gov (United States)

    Avery, S J; Sadaghiani, L; Sloan, A J; Waddington, R J

    2017-07-10

    Dentine matrix has proposed roles for directing mineralised tissue repair in dentine and bone; however, the range of bioactive components in dentine and specific biological effects on bone-derived mesenchymal stem cells (MSCs) in humans are less well understood. The aims of this study were to further elucidate the biological response of MSCs to demineralised dentine matrix (DDM) in enhancing wound repair responses and ascertain key contributing components. Dentine was obtained from human teeth and DDM proteins solubilised with ethylenediaminetetraacetic acid (EDTA). Bone marrow derived MSCs were commercially obtained. Cells with a more immature phenotype were then selected by preferential fibronectin adhesion (FN-BMMSCs) for use in subsequent in vitro assays. DDM at 10 µg/mL reduced cell expansion, attenuated apoptosis and was the minimal concentration capable of inducing osteoblastic differentiation. Enzyme-linked immunosorbent assay (ELISA) quantification of growth factors indicated physiological levels produced the above responses; transforming growth factor β (TGF-β1) was predominant (15.6 ng/mg DDM), with relatively lower concentrations of BMP-2, FGF, VEGF and PDGF (6.2-4.7 ng/mg DDM). Fractionation of growth factors from other DDM components by heparin affinity chromatography diminished osteogenic responses. Depletion of biglycan from DDM also attenuated osteogenic potency, which was partially rescued by the isolated biglycan. Decorin depletion from DDM had no influence on osteogenic potency. Collectively, these results demonstrate the potential of DDM for the delivery of physiological levels of growth factors for bone repair processes, and substantiate a role for biglycan as an additional adjuvant for driving osteogenic pathways.

  10. Alterations in proteins of bone marrow extracellular matrix in undernourished mice

    Directory of Open Access Journals (Sweden)

    C.L. Vituri

    2000-08-01

    Full Text Available The objective of the present study was to determine the effect of protein malnutrition on the glycoprotein content of bone marrow extracellular matrix (ECM. Two-month-old male Swiss mice were submitted to protein malnutrition with a low-protein diet containing 4% casein as compared to 20% casein in the control diet. When the experimental group had attained a 20% loss of their original body weight, we extracted the ECM proteins from bone marrow with PBS buffer, and analyzed ECM samples by SDS-PAGE (7.5% and ECL Western blotting. Quantitative differences were observed between control and experimental groups. Bone marrow ECM from undernourished mice had greater amounts of extractable fibronectin (1.6-fold increase and laminin (4.8-fold increase when compared to the control group. These results suggest an association between fluctuations in the composition of the hematopoietic microenvironment and altered hematopoiesis observed in undernourished mice.

  11. Heterogeneous and self-organizing mineralization of bone matrix promoted by hydroxyapatite nanoparticles.

    Science.gov (United States)

    Campi, G; Cristofaro, F; Pani, G; Fratini, M; Pascucci, B; Corsetto, P A; Weinhausen, B; Cedola, A; Rizzo, A M; Visai, L; Rea, G

    2017-11-16

    The mineralization process is crucial to the load-bearing characteristics of the bone extracellular matrix. In this work, we have studied the spatiotemporal dynamics of mineral deposition by human bone marrow mesenchymal stem cells differentiating toward osteoblasts promoted by the presence of exogenous hydroxyapatite nanoparticles. At the molecular level, the added nanoparticles positively modulated the expression of bone-specific markers and enhanced calcified matrix deposition during osteogenic differentiation. The nucleation, growth and spatial arrangement of newly deposited hydroxyapatite nanocrystals have been evaluated using scanning micro X-ray diffraction and scanning micro X-ray fluorescence. As leading results, we have found the emergence of a complex scenario where the spatial organization and temporal evolution of the process exhibit heterogeneous and self-organizing dynamics. At the same time the possibility of controlling the differentiation kinetics, through the addition of synthetic nanoparticles, paves the way to empower the generation of more structured bone scaffolds in tissue engineering and to design new drugs in regenerative medicine.

  12. Three dimensional printed macroporous polylactic acid/hydroxyapatite composite scaffolds for promoting bone formation in a critical-size rat calvarial defect model

    OpenAIRE

    Zhang, Haifeng; Mao, Xiyuan; Du, Zijing; Jiang, Wenbo; Han, Xiuguo; Zhao, Danyang; Han, Dong; Li, Qingfeng

    2016-01-01

    Abstract We have explored the applicability of printed scaffold by comparing osteogenic ability and biodegradation property of three resorbable biomaterials. A polylactic acid/hydroxyapatite (PLA/HA) composite with a pore size of 500??m and 60% porosity was fabricated by three-dimensional printing. Three-dimensional printed PLA/HA, ?-tricalcium phosphate (?-TCP) and partially demineralized bone matrix (DBM) seeded with bone marrow stromal cells (BMSCs) were evaluated by cell adhesion, prolife...

  13. Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2015-01-01

    Full Text Available The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group, followed by the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group. These results indicate that bridging 10-mm sciatic nerve defects with a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better

  14. Accurate 3-D Profile Extraction of Skull Bone Using an Ultrasound Matrix Array.

    Science.gov (United States)

    Hajian, Mehdi; Gaspar, Robert; Maev, Roman Gr

    2017-12-01

    The present study investigates the feasibility, accuracy, and precision of 3-D profile extraction of the human skull bone using a custom-designed ultrasound matrix transducer in Pulse-Echo. Due to the attenuative scattering properties of the skull, the backscattered echoes from the inner surface of the skull are severely degraded, attenuated, and at some points overlapped. Furthermore, the speed of sound (SOS) in the skull varies significantly in different zones and also from case to case; if considered constant, it introduces significant error to the profile measurement. A new method for simultaneous estimation of the skull profiles and the sound speed value is presented. The proposed method is a two-folded procedure: first, the arrival times of the backscattered echoes from the skull bone are estimated using multi-lag phase delay (MLPD) and modified space alternating generalized expectation maximization (SAGE) algorithms. Next, these arrival times are fed into an adaptive sound speed estimation algorithm to compute the optimal SOS value and subsequently, the skull bone thickness. For quantitative evaluation, the estimated bone phantom thicknesses were compared with the mechanical measurements. The accuracies of the bone thickness measurements using MLPD and modified SAGE algorithms combined with the adaptive SOS estimation were 7.93% and 4.21%, respectively. These values were 14.44% and 10.75% for the autocorrelation and cross-correlation methods. Additionally, the Bland-Altman plots showed the modified SAGE outperformed the other methods with -0.35 and 0.44 mm limits of agreement. No systematic error that could be related to the skull bone thickness was observed for this method.

  15. Time domain optical coherence tomography investigation of bone matrix interface in rat femurs

    Science.gov (United States)

    Rusu, Laura-Cristina; Negruá¹±iu, Meda-Lavinia; Sinescu, Cosmin; Hoinoiu, Bogdan; Topala, Florin-Ionel; Duma, Virgil-Florin; Rominu, Mihai; Podoleanu, Adrian G.

    2013-08-01

    The materials used to fabricate scaffolds for tissue engineering are derived from synthetic polymers, mainly from the polyester family, or from natural materials (e.g., collagen and chitosan). The mechanical properties and the structural properties of these materials can be tailored by adjusting the molecular weight, the crystalline state, and the ratio of monomers in the copolymers. Quality control and adjustment of the scaffold manufacturing process are essential to achieve high standard scaffolds. Most scaffolds are made from highly crystalline polymers, which inevitably result in their opaque appearance. Their 3-D opaque structure prevents the observation of internal uneven surface structures of the scaffolds under normal optical instruments, such as the traditional light microscope. The inability to easily monitor the inner structure of scaffolds as well as the interface with the old bone poses a major challenge for tissue engineering: it impedes the precise control and adjustment of the parameters that affect the cell growth in response to various mimicked culture conditions. The aim of this paper is to investigate the interface between the femur rat bone and the new bone that is obtained using a method of tissue engineering that is based on different artificial matrixes inserted in previously artificially induced defects. For this study, 15 rats were used in conformity with ethical procedures. In all the femurs a round defect was induced by drilling with a 1 mm spherical Co-Cr surgical drill. The matrixes used were Bioss and 4bone. These materials were inserted into the induced defects. The femurs were investigated at 1 week, 1 month, 2 month and three month after the surgical procedures. The interfaces were examined using Time Domain (TD) Optical Coherence Tomography (OCT) combined with Confocal Microscopy (CM). The optical configuration uses two single mode directional couplers with a superluminiscent diode as the source centered at 1300 nm. The scanning

  16. Biochemical studies of the macromolecular matrix of long bones in the Op/Orl mutant rat strain

    Energy Technology Data Exchange (ETDEWEB)

    Moczar, E; Berenholc, S; Phan-Dinh-Tuy, B; Robert, A M

    1978-01-01

    The long bones of normal and Op/Orl mutant rats were incubated with /sup 14/C-glucose and fractionated by EDTA and urea extraction. The analytical results of the various extracts suggested an increase in structural glycoprotein content and a decrease in collagen solubility in the long bones of mutants. Significant differences were found in the organic matrix composition of male and female bones of the two strains. /sup 14/C-glucose incorporation was stronger in males than in females. The presence of a glycosaminoglycan different from the chondroitinesulfate was shown in males. Basic amino acid content (lysine, arginine, histidine) was clearly higher in the insoluble residue of male bones .

  17. Biochemical studies of the macromolecular matrix of long bones in the Op/Orl mutant rat strain

    International Nuclear Information System (INIS)

    Moczar, E.; Berenholc, S.; Phan-Dinh-Tuy, B.; Robert, A.M.

    1978-01-01

    The long bones of normal and Op/Orl mutant rats were incubated with 14 C-glucose and fractionated by EDTA and urea extraction. The analytical results of the various extracts suggested an increase in structural glycoprotein content and a decrease in collagen solubility in the long bones of mutants. Significant differences were found in the organic matrix composition of male and female bones of the two strains. 14 C-glucose incorporation was stronger in males than in females. The presence of a glycosaminoglycan different from the chondroitinesulfate was shown in males. Basic amino acid content (lysine, arginine, histidine) was clearly higher in the insoluble residue of male bones

  18. Cleanup of TMI-2 demineralizer resins

    International Nuclear Information System (INIS)

    Bond, W.D.; King, L.J.; Knauer, J.B.; Hofstetter, K.J.; Thompson, J.D.

    1985-01-01

    Radiocesium is being removed from Demineralizers A and B (DA and DB by a process that was developed from laboratory tests on small samples of resin from the demineralizers. The process was designed to elute the radiocesium from the demineralizer resins and then to resorb it onto the zeolite ion exchangers contained in the Submerged Demineralizer System (SDS). The process was also required to limit the maximum cesium activities in the resin eluates (SDS feeds) so that the radiation field surrounding the pipelines would not be excessive. The process consists of 17 stages of batch elution. In the initial stage, the resin is contacted with 0.18 M boric acid. Subsequent stages subject the resin to increasing concentrations of sodium in NaH 2 BO 3 -H 3 BO 3 solution (total B = 0.35 M) and then 1 M sodium hydroxide in the final stages. Results on the performance of the process in the cleanup of the demineralizers at TMI-2 are compared to those obtained from laboratory tests with small samples of the DA and DB resins. To date, 15 stages of batch elution have been completed on the demineralizers at TMI-2 which resulted in the removal of about 750 Ci of radiocesium from DA and about 3300 Ci from DB

  19. Identification of osteocalcin as a permanent aging constituent of the bone matrix: basis for an accurate age at death determination.

    Science.gov (United States)

    Ritz, S; Turzynski, A; Schütz, H W; Hollmann, A; Rochholz, G

    1996-01-12

    Age at death determination based on aspartic acid racemization in dentin has been applied successfully in forensic odontology for several years now. An age-dependent accumulation of D-aspartic acid has also recently been demonstrated in bone osteocalcin, one of the most abundant noncollagenous proteins of the organic bone matrix. Evaluation of these initial data on in vivo racemization of aspartic acid in bone osteocalcin was taken a step further. After purification of osteocalcin from 53 skull bone specimens, the extent of aspartic acid racemization in this peptide was determined. The D-aspartic acid content of purified bone osteocalcin exhibited a very close relationship to age at death. This confirmed identification of bone osteocalcin as a permanent, 'aging' peptide of the organic bone matrix. Its D-aspartic acid content may be used as a measure of its age and hence that of the entire organism. The new biochemical approach to determination of age at death by analyzing bone is complex and demanding from a methodologic point of view, but appears to be superior in precision and reproducibility to most other methods applicable to bone.

  20. Multiscale, Converging Defects of Macro-Porosity, Microstructure and Matrix Mineralization Impact Long Bone Fragility in NF1

    Science.gov (United States)

    Kühnisch, Jirko; Seto, Jong; Lange, Claudia; Schrof, Susanne; Stumpp, Sabine; Kobus, Karolina; Grohmann, Julia; Kossler, Nadine; Varga, Peter; Osswald, Monika; Emmerich, Denise; Tinschert, Sigrid; Thielemann, Falk; Duda, Georg; Seifert, Wenke; el Khassawna, Thaqif; Stevenson, David A.; Elefteriou, Florent; Kornak, Uwe; Raum, Kay; Fratzl, Peter; Mundlos, Stefan; Kolanczyk, Mateusz

    2014-01-01

    Bone fragility due to osteopenia, osteoporosis or debilitating focal skeletal dysplasias is a frequent observation in the Mendelian disease Neurofibromatosis type 1 (NF1). To determine the mechanisms underlying bone fragility in NF1 we analyzed two conditional mouse models, Nf1Prx1 (limb knock-out) and Nf1Col1 (osteoblast specific knock-out), as well as cortical bone samples from individuals with NF1. We examined mouse bone tissue with micro-computed tomography, qualitative and quantitative histology, mechanical tensile analysis, small-angle X-ray scattering (SAXS), energy dispersive X-ray spectroscopy (EDX), and scanning acoustic microscopy (SAM). In cortical bone of Nf1Prx1 mice we detected ectopic blood vessels that were associated with diaphyseal mineralization defects. Defective mineral binding in the proximity of blood vessels was most likely due to impaired bone collagen formation, as these areas were completely devoid of acidic matrix proteins and contained thin collagen fibers. Additionally, we found significantly reduced mechanical strength of the bone material, which was partially caused by increased osteocyte volume. Consistent with these observations, bone samples from individuals with NF1 and tibial dysplasia showed increased osteocyte lacuna volume. Reduced mechanical properties were associated with diminished matrix stiffness, as determined by SAM. In line with these observations, bone tissue from individuals with NF1 and tibial dysplasia showed heterogeneous mineralization and reduced collagen fiber thickness and packaging. Collectively, the data indicate that bone fragility in NF1 tibial dysplasia is partly due to an increased osteocyte-related micro-porosity, hypomineralization, a generalized defect of organic matrix formation, exacerbated in the regions of tensional and bending force integration, and finally persistence of ectopic blood vessels associated with localized macro-porotic bone lesions. PMID:24465906

  1. Identification of transcriptional macromolecular associations in human bone using browser based in silico analysis in a giant correlation matrix.

    Science.gov (United States)

    Reppe, Sjur; Sachse, Daniel; Olstad, Ole K; Gautvik, Vigdis T; Sanderson, Paul; Datta, Harish K; Berg, Jens P; Gautvik, Kaare M

    2013-03-01

    Intracellular signaling is critically dependent on gene regulatory networks comprising physical molecular interactions. Presently, there is a lack of comprehensive databases for most human tissue types to verify such macromolecular interactions. We present a user friendly browser which helps to identify functional macromolecular interactions in human bone as significant correlations at the transcriptional level. The molecular skeletal phenotype has been characterized by transcriptome analysis of iliac crest bone biopsies from 84 postmenopausal women through quantifications of ~23,000 mRNA species. When the signal levels were inter-correlated, an array containing >260 million correlations was generated, thus recognizing the human bone interactome at the RNA level. The matrix correlation and p values were made easily accessible by a freely available online browser. We show that significant correlations within the giant matrix are reproduced in a replica set of 13 male vertebral biopsies. The identified correlations differ somewhat from transcriptional interactions identified in cell culture experiments and transgenic mice, thus demonstrating that care should be taken in extrapolating such results to the in vivo situation in human bone. The current giant matrix and web browser are a valuable tool for easy access to the human bone transcriptome and molecular interactions represented as significant correlations at the RNA-level. The browser and matrix should be a valuable hypothesis generating tool for identification of regulatory mechanisms and serve as a library of transcript relationships in human bone, a relatively inaccessible tissue. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Changes in subchondral bone mineral density and collagen matrix organization in growing horses.

    Science.gov (United States)

    Holopainen, Jaakko T; Brama, Pieter A J; Halmesmäki, Esa; Harjula, Terhi; Tuukkanen, Juha; van Weeren, P René; Helminen, Heikki J; Hyttinen, Mika M

    2008-12-01

    The effects of growth and maturation on the mineral deposition and the collagen framework of equine subchondral bone (SCB) were studied. Osteochondral specimens (diameter 6 mm) from the left metacarpophalangeal joint of 5-(n=8), 11-(n=8) and 18-month-old (n=6) horses were investigated at two differently loaded sites (Site 1 (S1): intermittent peak loading; Site 2 (S2): habitual loading). The SCB mineral density (BMD) was measured with peripheral quantitative computer tomography (pQCT), and the data were adjusted against the volume fraction (Vv) of the bone extracellular matrix (ECM). Polarised light microscopy (PLM) was used to analyze the Vv, the collagen fibril parallelism index and the orientation angle distribution in two fractions (1 mm/fraction) beneath the osteochondral junction of the SCB. PLM analysis was made along two randomly selected perpendicularly oriented vertical sections to measure the tissue anisotropy in the x-, y-, and z-directions. The BMD of SCB at S1 and S2 increased significantly during maturation. At the same time, the Vv of the ECM increased even more. This meant that the Vv-adjusted BMD decreased. There were no significant differences between sites. The basic collagen fibril framework of SCB seems to be established already at the age of 5 months. During maturation, the extracellular matrix underwent a decrease in collagen fibril parallelism but no changes in collagen orientation. The variation was negligible in the collagen network estimates in the two section planes. Growth and maturation induce significant changes in the equine SCB. The BMD increase in SCB is primarily due to the growth of bone volume and not to any increase in mineral deposition. An increase in weight-bearing appears to greatly affect the BMD and the volume of the extracellular matrix. Growth and maturation induce a striking change in collagen fibril parallelism but not in fibril orientation. The structural anisotropy of the subchondral bone is significant along the

  3. Formic acid demineralization does not affect the morphometry of cervical zygapophyseal joint meniscoids.

    Science.gov (United States)

    Farrell, Scott F; Osmotherly, Peter G; Rivett, Darren A; Cornwall, Jon

    2015-01-01

    Demineralization can facilitate the dissection of soft tissue structures in inaccessible locations by softening surrounding bone so that it can be easily removed without risking damage to the structure of interest. However, it is unclear whether demineralization alters the morphometry of soft tissues if used for this purpose. We have therefore examined the effect of extended-immersion formic acid demineralization on the size and shape of cervical zygapophyseal joint meniscoids to evaluate its usefulness as a means of facilitating dissection and examination of soft tissue structures from bony regions. Four cadaveric cervical spines were dissected, and three randomly selected zygapophyseal joints from each spine (12 in total) were removed, disarticulated and immersed in 5% formic acid for 32 days. Each joint was examined using a surgical microscope and photographed, and meniscoid length and surface area measured at days 0, 4, 18, and 32. Measurements were made on magnified digital photographs, and each measurement was repeated three times to determine intra-rater reliability. Data were analyzed using repeated-measures analysis of variance. Significance was set at p reliability was high (intra-class correlation > 0.9). These results support the use of formic acid demineralization to facilitate the study of cervical spine meniscoids by dissection, as even after a period of extended immersion in the solution, the morphometry of the structures was not significantly altered. Findings may have implications for dissection studies of other meniscoid-like soft tissue structures that use formic acid demineralization.

  4. Advanced bredigite-containing magnesium-matrix composites for biodegradable bone implant applications.

    Science.gov (United States)

    Dezfuli, Sina Naddaf; Huan, Zhiguang; Mol, Arjan; Leeflang, Sander; Chang, Jiang; Zhou, Jie

    2017-10-01

    The present research was aimed at developing magnesium-matrix composites that could allow effective control over their physiochemical and mechanical responses when in contact with physiological solutions. A biodegradable, bioactive ceramic - bredigite was chosen as the reinforcing phase in the composites, based on the hypothesis that the silicon- and magnesium-containing ceramic could protect magnesium from fast corrosion and at the same time stimulate cell proliferation. Methods to prepare composites with integrated microstructures - a prerequisite to achieve controlled biodegradation were developed. A systematic experimental approach was taken in order to elucidate the in vitro biodegradation mechanisms and kinetics of the composites. It was found that the composites with 20-40% homogenously dispersed bredigite particles, prepared from powders, could indeed significantly decrease the degradation rate of magnesium by up to 24 times. Slow degradation of the composites resulted in the retention of the mechanical integrity of the composites within the strength range of cortical bone after 12days of immersion in a cell culture medium. Cell attachment, cytotoxicity and bioactivity tests confirmed the stimulatory effects of bredigite embedded in the composites on the attachment, viability and differentiation of bone marrow stromal cells. Thus, the multiple benefits of adding bredigite to magnesium in enhancing degradation behavior, mechanical properties, biocompatibility and bioactivity were obtained. The results from this research showed the excellent potential of the bredigite-containing composites for bone implant applications, thus warranting further in vitro and in vivo research. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Allograft Cellular Bone Matrix in Extreme Lateral Interbody Fusion: Preliminary Radiographic and Clinical Outcomes

    Directory of Open Access Journals (Sweden)

    Antoine G. Tohmeh

    2012-01-01

    Full Text Available Introduction. Extreme lateral interbody fusion (XLIF is a minimally disruptive alternative for anterior lumbar interbody fusion. Recently, synthetic and allograft materials have been increasingly used to eliminate donor-site pain and complications secondary to autogenous bone graft harvesting. The clinical use of allograft cellular bone graft has potential advantages over autograft by eliminating the need to harvest autograft while mimicking autograft's biologic function. The objective of this study was to examine 12-month radiographic and clinical outcomes in patients who underwent XLIF with Osteocel Plus, one such allograft cellular bone matrix. Methods. Forty (40 patients were treated at 61 levels with XLIF and Osteocel Plus and included in the analysis. Results. No complications were observed. From preoperative to 12-month postoperative followup, ODI improved 41%, LBP improved 55%, leg pain improved 43.3%, and QOL (SF-36 improved 56%. At 12 months, 92% reported being “very” or “somewhat” satisfied with their outcome and 86% being either “very” or “somewhat likely” to choose to undergo the procedure again. Complete fusion was observed in 90.2% (55/61 of XLIF levels. Conclusions. Complete interbody fusion with Osteocel Plus was shown in 90.2% of XLIF levels, with the remaining 9.8% being partially consolidated and progressing towards fusion at 12 months.

  6. Organic composite-mediated surface coating of human acellular bone matrix with strontium.

    Science.gov (United States)

    Huang, Yi-Zhou; Wang, Jing-Jing; Huang, Yong-Can; Wu, Cheng-Guang; Zhang, Yi; Zhang, Chao-Liang; Bai, Lin; Xie, Hui-Qi; Li, Zhao-Yang; Deng, Li

    2018-03-01

    Acellular bone matrix (ACBM) provides an osteoconductive scaffold for bone repair, but its osteoinductivity is poor. Strontium (Sr) improves the osteoinductivity of bone implants. In this study, we developed an organic composite-mediated strontium coating strategy for ACBM scaffolds by using the ion chelating ability of carboxymethyl cellulose (CMC) and the surface adhesion ability of dopamine (DOPA). The organic coating composite, termed the CMC-DOPA-Sr composite, was synthesized under a mild condition, and its chemical structure and strontium ion chelating ability were then determined. After surface decoration, the physicochemical properties of the strontium-coated ACBM (ACBM-Sr) scaffolds were characterized, and their biocompatibility and osteoinductivity were determined in vitro and in vivo. The results showed that the CMC-DOPA-Sr composite facilitated strontium coating on the surface of ACBM scaffolds. The ACBM-Sr scaffolds possessed a sustained strontium ion release profile, exhibited good cytocompatibility, and enhanced the osteogenic differentiation of mesenchymal stem cells in vitro. Furthermore, the ACBM-Sr scaffolds showed good histocompatibility after subcutaneous implantation in nude mice. Taken together, this study provided a simple and mild strategy to realize strontium coating for ACBM scaffolds, which resulted in good biocompatibility and improved osteoinductivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Histone deacetylase 3 supports endochondral bone formation by controlling cytokine signaling and matrix remodeling

    Science.gov (United States)

    Carpio, Lomeli R.; Bradley, Elizabeth W.; McGee-Lawrence, Meghan E.; Weivoda, Megan M.; Poston, Daniel D.; Dudakovic, Amel; Xu, Ming; Tchkonia, Tamar; Kirkland, James L.; van Wijnen, Andre J.; Oursler, Merry Jo; Westendorf, Jennifer J.

    2017-01-01

    Histone deacetylase (HDAC) inhibitors are efficacious epigenetic-based therapies for some cancers and neurological disorders; however, each of these drugs inhibits multiple HDACs and has detrimental effects on the skeleton. To better understand how HDAC inhibitors affect endochondral bone formation, we conditionally deleted one of their targets, Hdac3, pre- and postnatally in type II collagen α1 (Col2α1)–expressing chondrocytes. Embryonic deletion was lethal, but postnatal deletion of Hdac3 delayed secondary ossification center formation, altered maturation of growth plate chondrocytes, and increased osteoclast activity in the primary spongiosa. HDAC3-deficient chondrocytes exhibited increased expression of cytokine and matrix-degrading genes (Il-6, Mmp3, Mmp13, and Saa3) and a reduced abundance of genes related to extracellular matrix production, bone development, and ossification (Acan, Col2a1, Ihh, and Col10a1). Histone acetylation increased at and near genes that had increased expression. The acetylation and activation of nuclear factor κB (NF-κB) were also increased in HDAC3-deficient chondrocytes. Increased cytokine signaling promoted autocrine activation of Janus kinase (JAK)–signal transducer and activator of transcription (STAT) and NF-κB pathways to suppress chondrocyte maturation, as well as paracrine activation of osteoclasts and bone resorption. Blockade of interleukin-6 (IL-6)–JAK–STAT signaling, NF-κB signaling, and bromodomain extraterminal proteins, which recognize acetylated lysines and promote transcriptional elongation, significantly reduced Il-6 and Mmp13 expression in HDAC3-deficient chondrocytes and secondary activation in osteoclasts. The JAK inhibitor ruxolitinib also reduced osteoclast activity in Hdac3 conditional knockout mice. Thus, HDAC3 controls the temporal and spatial expression of tissue-remodeling genes and inflammatory responses in chondrocytes to ensure proper endochondral ossification during development. PMID

  8. Influence of hyperbaric oxygen on biomechanics and structural bone matrix in type 1 diabetes mellitus rats.

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Justino Oliveira Limirio

    Full Text Available The aim of this study was to evaluate the biomechanics and structural bone matrix in diabetic rats subjected to hyperbaric oxygen therapy (HBO.Twenty-four male rats were divided into the following groups: Control; Control + HBO; Diabetic, and Diabetic + HBO. Diabetes was induced with streptozotocin (STZ in the diabetic Groups. After 30 days, HBO was performed every 48h in HBO groups and all animals were euthanized 60 days after diabetic induction. The femur was submitted to a biomechanical (maximum strength, energy-to-failure and stiffness and Attenuated Total Reflectance Fourier transform infrared (ATR-FTIR analyses (crosslink ratio, crystallinity index, matrix-to-mineral ratio: Amide I + II/Hydroxyapatite (M:MI and Amide III + Collagen/HA (M:MIII.In biomechanical analysis, diabetic animals showed lower values of maximum strength, energy and stiffness than non-diabetic animals. However, structural strength and stiffness were increased in groups with HBO compared with non-HBO. ATR-FTIR analysis showed decreased collagen maturity in the ratio of crosslink peaks in diabetic compared with the other groups. The bone from the diabetic groups showed decreased crystallinity compared with non-diabetic groups. M:MI showed no statistical difference between groups. However, M:MIII showed an increased matrix mineral ratio in diabetic+HBO and control+HBO compared with control and diabetic groups. Correlations between mechanical and ATR-FTIR analyses showed significant positive correlation between collagen maturity and stiffness.Diabetes decreased collagen maturation and the mineral deposition process, thus reducing biomechanical properties. Moreover, the study showed that HBO improved crosslink maturation and increased maximum strength and stiffness in the femur of T1DM animals.

  9. Influence of hyperbaric oxygen on biomechanics and structural bone matrix in type 1 diabetes mellitus rats.

    Science.gov (United States)

    Limirio, Pedro Henrique Justino Oliveira; da Rocha Junior, Huberth Alexandre; Morais, Richarlisson Borges de; Hiraki, Karen Renata Nakamura; Balbi, Ana Paula Coelho; Soares, Priscilla Barbosa Ferreira; Dechichi, Paula

    2018-01-01

    The aim of this study was to evaluate the biomechanics and structural bone matrix in diabetic rats subjected to hyperbaric oxygen therapy (HBO). Twenty-four male rats were divided into the following groups: Control; Control + HBO; Diabetic, and Diabetic + HBO. Diabetes was induced with streptozotocin (STZ) in the diabetic Groups. After 30 days, HBO was performed every 48h in HBO groups and all animals were euthanized 60 days after diabetic induction. The femur was submitted to a biomechanical (maximum strength, energy-to-failure and stiffness) and Attenuated Total Reflectance Fourier transform infrared (ATR-FTIR) analyses (crosslink ratio, crystallinity index, matrix-to-mineral ratio: Amide I + II/Hydroxyapatite (M:MI) and Amide III + Collagen/HA (M:MIII)). In biomechanical analysis, diabetic animals showed lower values of maximum strength, energy and stiffness than non-diabetic animals. However, structural strength and stiffness were increased in groups with HBO compared with non-HBO. ATR-FTIR analysis showed decreased collagen maturity in the ratio of crosslink peaks in diabetic compared with the other groups. The bone from the diabetic groups showed decreased crystallinity compared with non-diabetic groups. M:MI showed no statistical difference between groups. However, M:MIII showed an increased matrix mineral ratio in diabetic+HBO and control+HBO compared with control and diabetic groups. Correlations between mechanical and ATR-FTIR analyses showed significant positive correlation between collagen maturity and stiffness. Diabetes decreased collagen maturation and the mineral deposition process, thus reducing biomechanical properties. Moreover, the study showed that HBO improved crosslink maturation and increased maximum strength and stiffness in the femur of T1DM animals.

  10. An Autologous Bone Marrow Mesenchymal Stem Cell–Derived Extracellular Matrix Scaffold Applied with Bone Marrow Stimulation for Cartilage Repair

    Science.gov (United States)

    Tang, Cheng; Jin, Chengzhe; Du, Xiaotao; Yan, Chao; Min, Byoung-Hyun; Xu, Yan

    2014-01-01

    Purpose: It is well known that implanting a bioactive scaffold into a cartilage defect site can enhance cartilage repair after bone marrow stimulation (BMS). However, most of the current scaffolds are derived from xenogenous tissue and/or artificial polymers. The implantation of these scaffolds adds risks of pathogen transmission, undesirable inflammation, and other immunological reactions, as well as ethical issues in clinical practice. The current study was undertaken to evaluate the effectiveness of implanting autologous bone marrow mesenchymal stem cell–derived extracellular matrix (aBMSC-dECM) scaffolds after BMS for cartilage repair. Methods: Full osteochondral defects were performed on the trochlear groove of both knees in 24 rabbits. One group underwent BMS only in the right knee (the BMS group), and the other group was treated by implantation of the aBMSC-dECM scaffold after BMS in the left knee (the aBMSC-dECM scaffold group). Results: Better repair of cartilage defects was observed in the aBMSC-dECM scaffold group than in the BMS group according to gross observation, histological assessments, immunohistochemistry, and chemical assay. The glycosaminoglycan and DNA content, the distribution of proteoglycan, and the distribution and arrangement of type II and I collagen fibers in the repaired tissue in the aBMSC-dECM scaffold group at 12 weeks after surgery were similar to that surrounding normal hyaline cartilage. Conclusions: Implanting aBMSC-dECM scaffolds can enhance the therapeutic effect of BMS on articular cartilage repair, and this combination treatment is a potential method for successful articular cartilage repair. PMID:24666429

  11. Age-dependence of power spectral density and fractal dimension of bone mineralized matrix in atomic force microscope topography images: potential correlates of bone tissue age and bone fragility in female femoral neck trabeculae.

    Science.gov (United States)

    Milovanovic, Petar; Djuric, Marija; Rakocevic, Zlatko

    2012-11-01

    There is an increasing interest in bone nano-structure, the ultimate goal being to reveal the basis of age-related bone fragility. In this study, power spectral density (PSD) data and fractal dimensions of the mineralized bone matrix were extracted from atomic force microscope topography images of the femoral neck trabeculae. The aim was to evaluate age-dependent differences in the mineralized matrix of human bone and to consider whether these advanced nano-descriptors might be linked to decreased bone remodeling observed by some authors and age-related decline in bone mechanical competence. The investigated bone specimens belonged to a group of young adult women (n = 5, age: 20-40 years) and a group of elderly women (n = 5, age: 70-95 years) without bone diseases. PSD graphs showed the roughness density distribution in relation to spatial frequency. In all cases, there was a fairly linear decrease in magnitude of the power spectra with increasing spatial frequencies. The PSD slope was steeper in elderly individuals (-2.374 vs. -2.066), suggesting the dominance of larger surface morphological features. Fractal dimension of the mineralized bone matrix showed a significant negative trend with advanced age, declining from 2.467 in young individuals to 2.313 in the elderly (r = 0.65, P = 0.04). Higher fractal dimension in young women reflects domination of smaller mineral grains, which is compatible with the more freshly remodeled structure. In contrast, the surface patterns in elderly individuals were indicative of older tissue age. Lower roughness and reduced structural complexity (decreased fractal dimension) of the interfibrillar bone matrix in the elderly suggest a decline in bone toughness, which explains why aged bone is more brittle and prone to fractures. © 2012 The Authors Journal of Anatomy © 2012 Anatomical Society.

  12. Novel biocompatible polymeric blends for bone regeneration: Material and matrix design and development

    Science.gov (United States)

    Deng, Meng

    The first part of the work presented in this dissertation is focused on the design and development of novel miscible and biocompatible polyphosphazene-polyester blends as candidate materials for scaffold-based bone tissue engineering applications. Biodegradable polyesters such as poly(lactide-co-glycolide) (PLAGA) are among the most widely used polymeric materials for bone tissue engineering. However, acidic degradation products resulting from the bulk degradation mechanism often lead to catastrophic failure of the structure integrity, and adversely affect biocompatibility both in vitro and in vivo. One promising approach to circumvent these limitations is to blend PLAGA with other macromolecules that can buffer the acidic degradation products with a controlled degradation rate. Biodegradable polyphosphazenes (PPHOS), a new class of biomedical materials, have proved to be superior candidate materials to achieve this objective due to their unique buffering degradation products. A highly practical blending approach was adopted to develop novel biocompatible, miscible blends of these two polymers. In order to achieve this miscibility, a series of amino acid ester, alkoxy, aryloxy, and dipeptide substituted PPHOS were synthesized to promote hydrogen bonding interactions with PLAGA. Five mixed-substituent PPHOS compositions were designed and blended with PLAGA at different weight ratios producing candidate blends via a mutual solvent method. Preliminary characterization identified two specific side groups namely glycylglycine dipeptide and phenylphenoxy that resulted in improved blend miscibility and enhanced in vitro osteocompatibility. These findings led to the synthesis of a mixed-substituent polyphosphazene poly[(glycine ethyl glycinato)1(phenylphenoxy)1phosphazene] (PNGEGPhPh) for blending with PLAGA. Two dipeptide-based blends having weight ratios of PNGEGPhPh to PLAGA namely 25:75 (Matrix1) and 50:50 (Matrix2) were fabricated. Both of the blends were

  13. The role of lysyl oxidase, the extracellular matrix and the pre-metastatic niche in bone metastasis

    Directory of Open Access Journals (Sweden)

    Alison Gartland

    2016-09-01

    Full Text Available Most deaths from solid cancers occur as a result of secondary metastasis to distant sites. Bone is the most frequent metastatic site for many cancer types and can account for up to 80% of cancer-related deaths in certain tumours. The progression from a discrete solid primary tumour to devastating and painful bone metastases is a complex process involving multiple cell types and steps. There is increasing evidence that modulation of the extracellular matrix plays an important role in the lethal transition from a primary to disseminated metastatic bone tumour. This review provides an overview of the current understanding on the role of role of lysyl oxidase, the extracellular matrix and the pre-metastatic niche in bone metastasis

  14. Heterotopic bone formation in the musculus latissimus dorsi of sheep using β-tricalcium phosphate scaffolds: evaluation of an extended prefabrication time on bone formation and matrix degeneration.

    Science.gov (United States)

    Spalthoff, S; Jehn, P; Zimmerer, R; Möllmann, U; Gellrich, N-C; Kokemueller, H

    2015-06-01

    We previously generated viable heterotopic bone in living animals and found that 3 months of intrinsic vascularization improved bone formation and matrix degeneration. In this study, we varied the pre-vascularization time to determine its effects on the kinetics of bone formation and ceramic degradation. Two 25-mm-long cylindrical β-tricalcium phosphate scaffolds were filled intraoperatively with autogenous iliac crest bone marrow and implanted in the latissimus dorsi muscle in six sheep. To examine the effect of axial perfusion, one scaffold was surgically implanted with (group C) or without (group D) a central vascular bundle. All animals were sacrificed 6 months postoperatively and histomorphometric measurements were compared to previous results. All implanted scaffolds exhibited ectopic bone growth. However, bone growth was not significantly different between the 3-month (group A, 0.191±0.097 vs. group C, 0.237±0.075; P=0.345) and 6-month (group B, 0.303±0.105 vs. group D, 0.365±0.258; P=0.549) pre-vascularization durations, regardless of vessel supply; early differences between surgically and extrinsically vascularized constructs disappeared after 6 months. Here, we describe a reliable procedure for generating ectopic bone in vivo. A 3-month pre-vascularization duration appears sufficient and ceramic degradation proceeds in accordance with bone generation, supporting the hypothesis of cell-mediated resorption. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  15. Cartilage damage involving extrusion of mineralisable matrix from the articular calcified cartilage and subchondral bone

    Directory of Open Access Journals (Sweden)

    A Boyde

    2011-05-01

    Full Text Available Arthropathy of the distal articular surfaces of the third metacarpal (Mc3 and metatarsal (Mt3 bones in the Thoroughbred racehorse (Tb is a natural model of repetitive overload arthrosis. We describe a novel pathology that affects the articular calcified cartilage (ACC and subchondral bone (SCB and which is associated with hyaline articular cartilage degeneration. Parasagittal slices cut from the palmar quadrant of the distal condyles of the left Mc3/Mt3 of 39 trained Tbs euthanased for welfare reasons were imaged by point projection microradiography, and backscattered electron (BSE scanning electron microscopy (SEM, light microscopy, and confocal scanning light microscopy. Mechanical properties were studied by nanoindentation. Data on the horses' training and racing career were also collected. Highly mineralised projections were observed extending from cracks in the ACC mineralising front into the hyaline articular cartilage (HAC up to two-thirds the thickness of the HAC, and were associated with focal HAC surface fibrillation directly overlying their site. Nanoindentation identified this extruded matrix to be stiffer than any other mineralised phase in the specimen by a factor of two. The presence of projections was associated with a higher cartilage Mankin histology score (P < 0.02 and increased amounts of gross cartilage loss pathologically on the condyle (P < 0.02. Presence of projections was not significantly associated with: total number of racing seasons, age of horse, amount of earnings, number of days in training, total distance galloped in career, or presence of wear lines.

  16. Quantum dots as mineral- and matrix-specific strain gages for bone biomechanical studies

    Science.gov (United States)

    Zhu, Peizhi; Xu, Jiadi; Morris, Michael; Ramamoorthy, Ayyalusamy; Sahar, Nadder; Kohn, David

    2009-02-01

    We report the use of quantum dots (Qdots) as strain gages in the study of bone biomechanics using solid state nuclear magnetic resonance (NMR) spectroscopy. We have developed solid state NMR sample cells for investigation of deformations of bone tissue components at loads up to several Mega Pascal. The size constraints of the NMR instrumentation limit the bone specimen diameter and length to be no greater than 2-3 mm and 30 mm respectively. Further, magic angle spinning (MAS) solid state NMR experiments require the use of non-metallic apparatus that can be rotated at kilohertz rates. These experimental constraints preclude the use of standard biomechanical measurement systems. In this paper we explore the use of quantum dot center of gravity measurement as a strain gage technology consistent with the constraints of solid state NMR. We use Qdots that bind calcium (625 nm emission) and collagen (705 nm emission) for measurement of strain in these components. Compressive loads are applied to a specimen in a cell through a fine pitch screw turned with a mini-torque wrench. Displacement is measured as changes in the positions of arrays of quantum dots on the surface of a specimen. Arrays are created by spotting the specimen with dilute suspensions of Qdots. Mineral labeling is achieved with 705 nm carboxylated dots and matrix labeling with 565 nm quantum dots conjugated to collagen I antibodies. After each load increment the new positions of the quantum dots are measured by fluorescence microscopy. Changes in Qdot center of gravity as a function of applied load can be measured with submicron accuracy.

  17. Ornamenting 3D printed scaffolds with cell-laid extracellular matrix for bone tissue regeneration.

    Science.gov (United States)

    Pati, Falguni; Song, Tae-Ha; Rijal, Girdhari; Jang, Jinah; Kim, Sung Won; Cho, Dong-Woo

    2015-01-01

    3D printing technique is the most sophisticated technique to produce scaffolds with tailorable physical properties. But, these scaffolds often suffer from limited biological functionality as they are typically made from synthetic materials. Cell-laid mineralized ECM was shown to be potential for improving the cellular responses and drive osteogenesis of stem cells. Here, we intend to improve the biological functionality of 3D-printed synthetic scaffolds by ornamenting them with cell-laid mineralized extracellular matrix (ECM) that mimics a bony microenvironment. We developed bone graft substitutes by using 3D printed scaffolds made from a composite of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) and mineralized ECM laid by human nasal inferior turbinate tissue-derived mesenchymal stromal cells (hTMSCs). A rotary flask bioreactor was used to culture hTMSCs on the scaffolds to foster formation of mineralized ECM. A freeze/thaw cycle in hypotonic buffer was used to efficiently decellularize (97% DNA reduction) the ECM-ornamented scaffolds while preserving its main organic and inorganic components. The ECM-ornamented 3D printed scaffolds supported osteoblastic differentiation of newly-seeded hTMSCs by upregulating four typical osteoblastic genes (4-fold higher RUNX2; 3-fold higher ALP; 4-fold higher osteocalcin; and 4-fold higher osteopontin) and increasing calcium deposition compared to bare 3D printed scaffolds. In vivo, in ectopic and orthotopic models in rats, ECM-ornamented scaffolds induced greater bone formation than that of bare scaffolds. These results suggest a valuable method to produce ECM-ornamented 3D printed scaffolds as off-the-shelf bone graft substitutes that combine tunable physical properties with physiological presentation of biological signals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Current Concepts in Scaffolding for Bone Tissue Engineering.

    Science.gov (United States)

    Ghassemi, Toktam; Shahroodi, Azadeh; Ebrahimzadeh, Mohammad H; Mousavian, Alireza; Movaffagh, Jebraeel; Moradi, Ali

    2018-03-01

    Bone disorders are of significant worry due to their increased prevalence in the median age. Scaffold-based bone tissue engineering holds great promise for the future of osseous defects therapies. Porous composite materials and functional coatings for metallic implants have been introduced in next generation of orthopedic medicine for tissue engineering. While osteoconductive materials such as hydroxyapatite and tricalcium phosphate ceramics as well as some biodegradable polymers are suggested, much interest has recently focused on the use of osteoinductive materials like demineralized bone matrix or bone derivatives. However, physiochemical modifications in terms of porosity, mechanical strength, cell adhesion, biocompatibility, cell proliferation, mineralization and osteogenic differentiation are required. This paper reviews studies on bone tissue engineering from the biomaterial point of view in scaffolding. Level of evidence: I.

  19. Fabrication method, structure, mechanical, and biological properties of decellularized extracellular matrix for replacement of wide bone tissue defects.

    Science.gov (United States)

    Anisimova, N Y; Kiselevsky, M V; Sukhorukova, I V; Shvindina, N V; Shtansky, D V

    2015-09-01

    The present paper was focused on the development of a new method of decellularized extracellular matrix (DECM) fabrication via a chemical treatment of a native bone tissue. Particular attention was paid to the influence of chemical treatment on the mechanical properties of native bones, sterility, and biological performance in vivo using the syngeneic heterotopic and orthotopic implantation models. The obtained data indicated that after a chemical decellularization treatment in 4% aqueous sodium chlorite, no noticeable signs of the erosion of compact cortical bone surface or destruction of trabeculae of spongy bone in spinal channel were observed. The histological studies showed that the chemical treatment resulted in the decellularization of both bone and cartilage tissues. The DECM samples demonstrated no signs of chemical and biological degradation in vivo. Thorough structural characterization revealed that after decellularization, the mineral frame retained its integrity with the organic phase; however clotting and destruction of organic molecules and fibers were observed. FTIR studies revealed several structural changes associated with the destruction of organic molecules, although all organic components typical of intact bone were preserved. The decellularization-induced structural changes in the collagen constituent resulted changed the deformation under compression mechanism: from the major fracture by crack propagation throughout the sample to the predominantly brittle fracture. Although the mechanical properties of radius bones subjected to decellularization were observed to degrade, the mechanical properties of ulna bones in compression and humerus bones in bending remained unchanged. The compressive strength of both the intact and decellularized ulna bones was 125-130 MPa and the flexural strength of humerus bones was 156 and 145 MPa for the intact and decellularized samples, respectively. These results open new avenues for the use of DECM samples as

  20. Effect of enamel matrix derivative and parathyroid hormone on bone formation in standardized osseous defects: an experimental study in minipigs

    DEFF Research Database (Denmark)

    Jensen, Simon S; Chen, B; Bornstein, Michael M

    2011-01-01

    Previous experimental studies have indicated that locally administered enamel matrix derivative (EMD) and parathyroid hormone (PTH) may have a stimulatory effect on bone formation. However, it is not clear if the positive effect of EMD is related to its effect on the periodontium as a whole...

  1. Effect of Oxytetracycline on In vitro Mineralization and Demineralization Reactions in the Absence and Presence of Collagen

    Directory of Open Access Journals (Sweden)

    Monica Kakkar

    2017-11-01

    Full Text Available Introduction: Oxytetracycline and its derivatives are routinely used to treat various ailments have also been shown to inhibit embryonic bone formation, mineralization in pregnant female rats and parathyroid hormone induced demineralization of bones. Oxytetracycline has also been routinely used as bone fluorochrome to study bone metabolism. However, despite the above observations, its mechanism of action is not clearly understood. Some studies tend to suggest that it acts by inhibiting collagen biosynthesis while others indicate that it acts without influencing collagen metabolism. Aim: To study the mechanism by which oxytetracycline influences the mineralization and demineralization reactions. Materials and Methods: Homogeneous and heterogeneous systems of in vitro mineralization under physiological conditions of temperature, pH and ionic strength were used to investigate the effect of oxytetracycline not only on initial mineral phase formation but also on its subsequent growth or demineralization. In the Homogenous system, supersaturated conditions with respect to calcium and phosphate ions were employed to study their precipitation as mineral phase resembling hydroxyapatite in nature. However, in the heterogeneous system, collagen isolated from sheep tendons was used to induce identical mineral phases under saturated conditions with respect to calcium and phosphate ions prevailing in the body fluids. Results: The study demonstrated that in the homogeneous reaction system (mineralization in the absence of collagen oxytetracycline inhibited both the initial mineral phase formation and its subsequent growth without influencing its demineralization. However, in the heterogeneous system, oxytetracycline was found to inhibit not only the initial mineralization but also its subsequent growth or demineralization. Conclusion: Oxytetracycline acted like crystal poisons to inhibit the mineralization and demineralization reactions by tightly associating

  2. Biological Assessment of a Calcium Silicate Incorporated Hydroxyapatite-Gelatin Nanocomposite: A Comparison to Decellularized Bone Matrix

    Directory of Open Access Journals (Sweden)

    Dong Joon Lee

    2014-01-01

    Full Text Available Our laboratory utilized biomimicry to develop a synthetic bone scaffold based on hydroxyapatite-gelatin-calcium silicate (HGCS. Here, we evaluated the potential of HGCS scaffold in bone formation in vivo using the rat calvarial critical-sized defect (CSD. Twelve Sprague-Dawley rats were randomized to four groups: control (defect only, decellularized bone matrix (DECBM, and HGCS with and without multipotent adult progenitor cells (MAPCs. DECBM was prepared by removing all the cells using SDS and NH4OH. After 12 weeks, the CSD specimens were harvested to evaluate radiographical, histological, and histomorphometrical outcomes. The in vitro osteogenic effects of the materials were studied by focal adhesion, MTS, and alizarin red. Micro-CT analysis indicated that the DECBM and the HGCS scaffold groups developed greater radiopaque areas than the other groups. Bone regeneration, assessed using histological analysis and fluorochrome labeling, was the highest in the HGCS scaffold seeded with MAPCs. The DECBM group showed limited osteoinductivity, causing a gap between the implant and host tissue. The group grafted with HGCS+MAPCs resulting in twice as much new bone formation seems to indicate a role for effective bone regeneration. In conclusion, the novel HGCS scaffold could improve bone regeneration and is a promising carrier for stem cell-mediated bone regeneration.

  3. Antibacterial glass and glass-biodegradable matrix composites for bone tissue engineering

    OpenAIRE

    Fernandes, João Pedro Silva

    2017-01-01

    Multiple joint and bone diseases affect millions of people worldwide. In fact the Bone and Joint Decade’s association predicted that the percentage of people over 50 years of age affected by bone diseases will double by 2020. Bone diseases commonly require the need for surgical intervention, often involving partial or total bone substitution. Therefore biodegradable biomaterials designed as bone tissue engineered (BTE) devices to be implanted into the human body, function as a ...

  4. Bone matrix calcification during embryonic and postembryonic rat calvarial development assessed by SEM-EDX spectroscopy, XRD, and FTIR spectroscopy.

    Science.gov (United States)

    Henmi, Akiko; Okata, Hiroshi; Anada, Takahisa; Yoshinari, Mariko; Mikami, Yasuto; Suzuki, Osamu; Sasano, Yasuyuki

    2016-01-01

    Bone mineral is constituted of biological hydroxyapatite crystals. In developing bone, the mineral crystal matures and the Ca/P ratio increases. However, how an increase in the Ca/P ratio is involved in maturation of the crystal is not known. The relationships among organic components and mineral changes are also unclear. The study was designed to investigate the process of calcification during rat calvarial bone development. Calcification was evaluated by analyzing the atomic distribution and concentration of Ca, P, and C with scanning electron microscopy (SEM)-energy-dispersive X-ray (EDX) spectroscopy and changes in the crystal structure with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Histological analysis showed that rat calvarial bone formation started around embryonic day 16. The areas of Ca and P expanded, matching the region of the developing bone matrix, whereas the area of C became localized around bone. X-ray diffraction and FTIR analysis showed that the amorphous-like structure of the minerals at embryonic day 16 gradually transformed into poorly crystalline hydroxyapatite, whereas the proportion of mineral to protein increased until postnatal week 6. FTIR analysis also showed that crystallization of hydroxyapatite started around embryonic day 20, by which time SEM-EDX spectroscopy showed that the Ca/P ratio had increased and the C/Ca and C/P ratios had decreased significantly. The study suggests that the Ca/P molar ratio increases and the proportion of organic components such as proteins of the bone matrix decreases during the early stage of calcification, whereas crystal maturation continues throughout embryonic and postembryonic bone development.

  5. Osteoclastic bone degradation and the role of different cysteine proteinases and matrix metalloproteinases: differences between calvaria and long bone

    NARCIS (Netherlands)

    Everts, Vincent; Korper, Wolf; Hoeben, Kees A.; Jansen, Ineke D. C.; Bromme, Dieter; Cleutjens, Kitty B. J. M.; Heeneman, Sylvia; Peters, Christoph; Reinheckel, Thomas; Saftig, Paul; Beertsen, Wouter

    2006-01-01

    Osteoclastic bone degradation involves the activity of cathepsin K. We found that in addition to this enzyme other, yet unknown, cysteine proteinases participate in digestion. The results support the notion that osteoclasts from different bone sites use different enzymes to degrade the collagenous

  6. The effects of orbital spaceflight on bone histomorphometry and messenger ribonucleic acid levels for bone matrix proteins and skeletal signaling peptides in ovariectomized growing rats

    Science.gov (United States)

    Cavolina, J. M.; Evans, G. L.; Harris, S. A.; Zhang, M.; Westerlind, K. C.; Turner, R. T.

    1997-01-01

    A 14-day orbital spaceflight was performed using ovariectomized Fisher 344 rats to determine the combined effects of estrogen deficiency and near weightlessness on tibia radial bone growth and cancellous bone turnover. Twelve ovariectomized rats with established cancellous osteopenia were flown aboard the space shuttle Columbia (STS-62). Thirty ovariectomized rats were housed on earth as ground controls: 12 in animal enclosure modules, 12 in vivarium cages, and 6 killed the day of launch for baseline measurements. An additional 18 ovary-intact rats were housed in vivarium cages as ground controls: 8 rats were killed as baseline controls and the remaining 10 rats were killed 14 days later. Ovariectomy increased periosteal bone formation at the tibia-fibula synostosis; cancellous bone resorption and formation in the secondary spongiosa of the proximal tibial metaphysis; and messenger RNA (mRNA) levels for the prepro-alpha2(1) subunit of type 1 collagen, osteocalcin, transforming growth factor-beta, and insulin-like growth factor I in the contralateral proximal tibial metaphysis and for the collagen subunit in periosteum pooled from tibiae and femora and decreased cancellous bone area. Compared to ovariectomized weight-bearing rats, the flight group experienced decreases in periosteal bone formation, collagen subunit mRNA levels, and cancellous bone area. The flight rats had a small decrease in the cancellous mineral apposition rate, but no change in the calculated bone formation rate. Also, spaceflight had no effect on cancellous osteoblast and osteoclast perimeters or on mRNA levels for bone matrix proteins and signaling peptides. On the other hand, spaceflight resulted in an increase in bone resorption, as ascertained from the diminished retention of a preflight fluorochrome label. This latter finding suggests that osteoclast activity was increased. In a follow-up ground-based experiment, unilateral sciatic neurotomy of ovariectomized rats resulted in cancellous

  7. A Novel High Mechanical Property PLGA Composite Matrix Loaded with Nanodiamond-Phospholipid Compound for Bone Tissue Engineering.

    Science.gov (United States)

    Zhang, Fan; Song, Qingxin; Huang, Xuan; Li, Fengning; Wang, Kun; Tang, Yixing; Hou, Canglong; Shen, Hongxing

    2016-01-20

    A potential bone tissue engineering material was produced from a biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), loaded with nanodiamond phospholipid compound (NDPC) via physical mixing. On the basis of hydrophobic effects and physical absorption, we modified the original hydrophilic surface of the nanodiamond (NDs) with phospholipids to be amphipathic, forming a typical core-shell structure. The ND-phospholipid weight ratio was optimized to generate sample NDPC50 (i.e., ND-phospholipid weight ratio of 100:50), and NDPC50 was able to be dispersed in a PLGA matrix at up to 20 wt %. Compared to a pure PLGA matrix, the introduction of 10 wt % of NDPC (i.e., sample NDPC50-PF10) resulted in a significant improvement in the material's mechanical and surface properties, including a decrease in the water contact angle from 80 to 55°, an approximately 100% increase in the Young's modulus, and an approximate 550% increase in hardness, thus closely resembling that of human cortical bone. As a novel matrix supporting human osteoblast (hFOB1.19) growth, NDPC50-PFs with different amounts of NDPC50 demonstrated no negative effects on cell proliferation and osteogenic differentiation. Furthermore, we focused on the behaviors of NDPC-PFs implanted into mice for 8 weeks and found that NDPC-PFs induced acceptable immune response and can reduce the rapid biodegradation of PLGA matrix. Our results represent the first in vivo research on ND (or NDPC) as nanofillers in a polymer matrix for bone tissue engineering. The high mechanical properties, good in vitro and in vivo biocompatibility, and increased mineralization capability suggest that biodegradable PLGA composite matrices loaded with NDPC may potentially be useful for a variety of biomedical applications, especially bone tissue engineering.

  8. Management Strategy for Unicameral Bone Cyst

    Directory of Open Access Journals (Sweden)

    Chin-Yi Chuo

    2003-06-01

    Full Text Available The management of a unicameral bone cyst varies from percutaneous needle biopsy, aspiration, and local injection of steroid, autogenous bone marrow, or demineralized bone matrix to the more invasive surgical procedures of conventional curettage and grafting (with autogenous or allogenous bone or subtotal resection with bone grafting. The best treatment for a unicameral bone cyst is yet to be identified. Better understanding of the pathology will change the concept of management. The aim of treatment is to prevent pathologic fracture, to promote cyst healing, and to avoid cyst recurrence and re-fracture. We retrospectively reviewed 17 cases of unicameral bone cysts (12 in the humerus, 3 in the femur, 2 in the fibula managed by conservative observation, curettage and bone grafting with open reduction and internal fixation, or continuous decompression and drainage with a cannulated screw. We suggest percutaneous cannulated screw insertion to promote cyst healing and prevent pathologic fracture. We devised a protocol for the management of unicameral bone cysts.

  9. Effect of Extracellular Matrix Membrane on Bone Formation in a Rabbit Tibial Defect Model

    Directory of Open Access Journals (Sweden)

    Jin Wook Hwang

    2016-01-01

    Full Text Available Absorbable extracellular matrix (ECM membrane has recently been used as a barrier membrane (BM in guided tissue regeneration (GTR and guided bone regeneration (GBR. Absorbable BMs are mostly based on collagen, which is more biocompatible than synthetic materials. However, implanted absorbable BMs can be rapidly degraded by enzymes in vivo. In a previous study, to delay degradation time, collagen fibers were treated with cross-linking agents. These compounds prevented the enzymatic degradation of BMs. However, cross-linked BMs can exhibit delayed tissue integration. In addition, the remaining cross-linker could induce inflammation. Here, we attempted to overcome these problems using a natural ECM membrane. The membrane consisted of freshly harvested porcine pericardium that was stripped from cells and immunoreagents by a cleaning process. Acellular porcine pericardium (APP showed a bilayer structure with a smooth upper surface and a significantly coarser bottom layer. APP is an ECM with a thin layer (0.18–0.35 mm but with excellent mechanical properties. Tensile strength of APP was 14.15±2.24 MPa. In in vivo experiments, APP was transplanted into rabbit tibia. The biocompatible material was retained for up to 3 months without the need for cross-linking. Therefore, we conclude that APP could support osteogenesis as a BM for up to 3 months.

  10. Calcium-phosphate matrix with or without TGF-β3 improves tendon-bone healing after rotator cuff repair.

    Science.gov (United States)

    Kovacevic, David; Fox, Alice J; Bedi, Asheesh; Ying, Liang; Deng, Xiang-Hua; Warren, Russell F; Rodeo, Scott A

    2011-04-01

    Rotator cuff tendon heals by formation of an interposed zone of fibrovascular scar tissue. Recent studies demonstrate that transforming growth factor-beta 3 (TGF-β(3)) is associated with tissue regeneration and "scarless" healing, in contrast to scar-mediated healing that occurs with TGF-β(1). Delivery of TGF-β(3) in an injectable calcium-phosphate matrix to the healing tendon-bone interface after rotator cuff repair will result in increased attachment strength secondary to improved bone formation and collagen organization and reduced scar formation of the healing enthesis. Controlled laboratory study. Ninety-six male Sprague-Dawley rats underwent unilateral detachment of the supraspinatus tendon followed by acute repair using transosseous suture fixation. Animals were allocated into 1 of 3 groups: (1) repair alone (controls, n = 32), (2) repair augmented by application of an osteoconductive calcium-phosphate (Ca-P) matrix only (n = 32), or (3) repair augmented with Ca-P matrix + TGF-β(3) (2.75 µg) at the tendon-bone interface (n = 32). Animals were euthanized at either 2 weeks or 4 weeks postoperatively. Biomechanical testing of the supraspinatus tendon-bone complex was performed at 2 and 4 weeks (n = 8 per group). Microcomputed tomography was utilized to quantitate bone microstructure at the repair site. The healing tendon-bone interface was evaluated with histomorphometry and immunohistochemical localization of collagen types I (COLI) and III (COLIII). Statistical analysis was performed using 2-way analysis of variance with significance set at P repair site is associated with new bone formation, increased fibrocartilage, and improved collagen organization at the healing tendon-bone interface in the early postoperative period after rotator cuff repair. The addition of TGF-β(3) significantly improved strength of the repair at 4 weeks postoperatively and resulted in a more favorable COLI/COLIII ratio. The delivery of TGF-β(3) with an injectable Ca-P matrix

  11. Does collagen trigger the recruitment of osteoblasts into vacated bone resorption lacunae during bone remodeling?

    DEFF Research Database (Denmark)

    Abdelgawad, Mohamed Essameldin; Søe, Kent; Andersen, Thomas Levin

    2014-01-01

    matrix molecules, collagen's potency was superior and only equaled by fibronectin. Next, the majority of the newly recruited osteoblast lineage cells positioned immediately next to the osteoclasts exhibit uPARAP/Endo180, an endocytic collagen receptor reported to be involved in collagen internalization......Osteoblast recruitment during bone remodeling is obligatory to re-construct the bone resorbed by the osteoclast. This recruitment is believed to be triggered by osteoclast products and is therefore likely to start early during the remodeling cycle. Several osteoclast products with osteoblast...... recruitment potential are already known. Here we draw the attention on the osteoblast recruitment potential of the collagen that is freshly demineralized by the osteoclast. Our evidence is based on observations on adult human cancellous bone, combined with in vitro assays. First, freshly eroded surfaces where...

  12. Demineralised human dentine matrix stimulates the expression of VEGF and accelerates the bone repair in tooth sockets of rats.

    Science.gov (United States)

    Reis-Filho, Cláudio R; Silva, Elisângela R; Martins, Adalberto B; Pessoa, Fernanda F; Gomes, Paula V N; de Araújo, Mariana S C; Miziara, Melissa N; Alves, José B

    2012-05-01

    In this study we investigated the possible use of human demineralised dentine matrix (DHDM), obtained from the extracted teeth, as bone graft material and evaluated the expression of vascular endothelial growth factor (VEGF) induced by this material in the healing process of tooth sockets of rats. To evaluate bone regeneration and expression of VEGF induced by DHDM, thirty-two male Wistar rats weighing approximately 200 g were used. After maxillary second molar extraction, the left sockets were filled with DHDM and the right sockets were naturally filled by blood clot (control). The animals were sacrificed at 3, 7, 14 and 21 days after surgery and upper maxillaries were processed for histological, morphometric and immunohistochemical analyses. DHDM was used to evaluate the mechanical effect of bone graft material into sockets. Expression of VEGF was determined by immunohistochemistry in all groups. Our results demonstrated a significant increase in the newly formed bone tissue in sockets of 7, 14 and 21 days and a significant increase in VEGF expression at days 7 and 14 on treated sockets. Our results showed that DHDM increases the expression of VEGF and accelerates the healing process in rats tooth sockets, by stimulating bone deposition and also vessels formation. These results suggest that DHDM has osteoinductive/osteoconductive potential and may represent an efficient grafting material on guided bone regeneration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Comparison of efficacies of different bone substitutes adhered to osteoblasts with and without extracellular matrix proteins

    Directory of Open Access Journals (Sweden)

    Li-Ling Tseng

    2013-12-01

    Conclusion: The results indicated that ECM proteins increased cell attachment to bone substitutes in vitro. The preferential affinity of different bone substitutes to certain ECM proteins was evident. Cerasorb and BoneCeramic had better MG63 human osteosarcoma cell adhesion ability than Bio-Oss and MBCP.

  14. Scaffolds for bone regeneration made of hydroxyapatite microspheres in a collagen matrix

    Energy Technology Data Exchange (ETDEWEB)

    Cholas, Rahmatullah, E-mail: rahmat.cholas@gmail.com; Kunjalukkal Padmanabhan, Sanosh, E-mail: sanosh2001@gmail.com; Gervaso, Francesca; Udayan, Gayatri; Monaco, Graziana; Sannino, Alessandro; Licciulli, Antonio

    2016-06-01

    Biomimetic scaffolds with a structural and chemical composition similar to native bone tissue may be promising for bone tissue regeneration. In the present work hydroxyapatite mesoporous microspheres (mHA) were incorporated into collagen scaffolds containing an ordered interconnected macroporosity. The mHA were obtained by spray drying of a nano hydroxyapatite slurry prepared by the precipitation technique. X-ray diffraction (XRD) analysis revealed that the microspheres were composed only of hydroxyapatite (HA) phase, and energy-dispersive x-ray spectroscopy (EDS) analysis revealed the Ca/P ratio to be 1.69 which is near the value for pure HA. The obtained microspheres had an average diameter of 6 μm, a specific surface area of 40 m{sup 2}/g as measured by Brunauer-Emmett-Teller (BET) analysis, and Barrett-Joyner-Halenda (BJH) analysis showed a mesoporous structure with an average pore diameter of 16 nm. Collagen/HA-microsphere (Col/mHA) composite scaffolds were prepared by freeze-drying followed by dehydrothermal crosslinking. SEM observations of Col/mHA scaffolds revealed HA microspheres embedded within a porous collagen matrix with a pore size ranging from a few microns up to 200 μm, which was also confirmed by histological staining of sections of paraffin embedded scaffolds. The compressive modulus of the composite scaffold at low and high strain values was 1.7 and 2.8 times, respectively, that of pure collagen scaffolds. Cell proliferation measured by the MTT assay showed more than a 3-fold increase in cell number within the scaffolds after 15 days of culture for both pure collagen scaffolds and Col/mHA composite scaffolds. Attractive properties of this composite scaffold include the potential to load the microspheres for drug delivery and the controllability of the pore structure at various length scales. - Highlights: • Mesoporous hydroxyapatite microsphere(mHA) synthesized by spray drying method • Porous collagen/mHA composite scaffold made by freeze

  15. Composite porous scaffold of PEG/PLA support improved bone matrix deposition in vitro compared to PLA-only scaffolds.

    Science.gov (United States)

    Bhaskar, Birru; Owen, Robert; Bahmaee, Hossein; Wally, Zena; Sreenivasa Rao, Parcha; Reilly, Gwendolen C

    2018-05-01

    Controllable pore size and architecture are essential properties for tissue-engineering scaffolds to support cell ingrowth colonization. To investigate the effect of polyethylene glycol (PEG) addition on porosity and bone-cell behavior, porous polylactic acid (PLA)-PEG scaffolds were developed with varied weight ratios of PLA-PEG (100/0, 90/10, 75/25) using solvent casting and porogen leaching. Sugar 200-300 µm in size was used as a porogen. To assess scaffold suitability for bone tissue engineering, MLO-A5 murine osteoblast cells were cultured and cell metabolic activity, alkaline phosphatase (ALP) activity and bone-matrix production determined using (alizarin red S staining for calcium and direct red 80 staining for collagen). It was found that metabolic activity was significantly higher over time on scaffolds containing PEG, ALP activity and mineralized matrix production were also significantly higher on scaffolds containing 25% PEG. Porous architecture and cell distribution and penetration into the scaffold were analyzed using SEM and confocal microscopy, revealing that inclusion of PEG increased pore interconnectivity and therefore cell ingrowth in comparison to pure PLA scaffolds. The results of this study confirmed that PLA-PEG porous scaffolds support mineralizing osteoblasts better than pure PLA scaffolds, indicating they have a high potential for use in bone tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1334-1340, 2018. © 2018 Wiley Periodicals, Inc.

  16. Treatment for unicameral bone cysts in long bones: an evidence based review.

    Science.gov (United States)

    Donaldson, Sandra; Chundamala, Josie; Yandow, Suzanne; Wright, James G

    2010-03-20

    The purpose of this paper is to perform an evidence based review for treatment of unicameral bone cysts. A search of MEDLINE (1966 to 2009) was conducted and the studies were classified according to levels of evidence. This review includes only comparative Level I-III studies. The systematic review identified 16 studies. There is one level I study, one level II study and the remaining 14 studies are level III. Seven of the sixteen studies had statistically different results: three studies indicated that steroid injection was superior to bone marrow injection or curettage and bone grafting; one study indicated that cannulated screws were superior to steroid injections; one study indicated resection and myoplasty was superior to steroid injection; one study indicated a combination of steroid, demineralized bone matrix and bone marrow aspirate, and curettage and bone grafting were superior to steroid injection; and one study indicated that curettage and bone grafting was superior to non-operative immobilization. Based on one Level I study, including a limited number of individuals, steroid injection seems to be superior to bone marrow injection. As steroid injections have already demonstrated superiority over bone marrow injections in a randomized clinical trial, the next step would be a prospective trial comparing steroid injections with other treatments.

  17. Treatment for unicameral bone cysts in long bones: an evidence based review

    Directory of Open Access Journals (Sweden)

    Sandra E. Donaldson

    2010-05-01

    Full Text Available The purpose of this paper is to perform an evidence based review for treatment of unicameral bone cysts. A search of MEDLINE (1966 to 2009 was conducted and the studies were classified according to levels of evidence. This review includes only comparative Level I-III studies. The systematic review identified 16 studies. There is one level I study, one level II study and the remaining 14 studies are level III. Seven of the sixteen studies had statistically different results: three studies indicated that steroid injection was superior to bone marrow injection or curettage and bone grafting; one study indicated that cannulated screws were superior to steroid injections; one study indicated resection and myoplasty was superior to steroid injection; one study indicated a combination of steroid, demineralized bone matrix and bone marrow aspirate, and curettage and bone grafting were superior to steroid injection; and one study indicated that curettage and bone grafting was superior to non-operative immobilization. Based on one Level I study, including a limited number of individuals, steroid injection seems to be superior to bone marrow injection. As steroid injections have already demonstrated superiority over bone marrow injections in a randomized clinical trial, the next step would be a prospective trial comparing steroid injections with other treatments.

  18. Autogenous bone versus deproteinised bovine bone matrix in 1-stage lateral sinus floor elevation in the severely atrophied maxilla: a randomised controlled trial.

    Science.gov (United States)

    Merli, Mauro; Moscatelli, Marco; Mariotti, Giorgia; Rotundo, Roberto; Nieri, Michele

    2013-01-01

    To compare 100% deproteinised bovine bone matrix (DBBM) grafts (test group) with 100% autogenous bone (AB) grafts (control group) for lateral maxillary sinus floor elevation in a parallel group, superiority, randomised controlled trial. Patients with 1 to 3 mm of residual bone height below the maxillary sinus were randomised for sinus floor elevation with DBBM and AB grafts and simultaneous implant placement. Randomisation was computer generated with allocation concealment by sealed envelopes and the radiographic examiner was blinded to group assignment. The abutment connection was performed 8 months after surgery and insertion of the provisional prostheses was performed 9 months after surgery. Outcome variables were implant failures, prosthetic failures, complications, chair time, postoperative pain and radiographic bone level 6 months after loading. Forty patients were randomised: 20 (32 implants) to the DBBM group and 20 (27 implants) to the AB group. One patient from the AB group dropped out. Two implant failures occurred in the DBBM group and no implant failure occurred in the AB group (P = 0.4872). All of the planned prostheses could be delivered. One complication occurred in the DBBM group and 2 in the AB group (P = 0.6050). Chair time was shorter for the DBBM group, with a difference of 27.3 minutes (P = 0.0428). Pain difference measured with a visual analogue scale for 6 days post-surgery was 0.2 in favour of the DBBM group (P = 0.6838). The difference in vertical bone height was 0.0 mm (95% CI -1.1, 1.1; P = 0.9703) and the difference in marginal bone level was 0.3 in favour of AB (95% CI -0.3, 0.9; P = 0.3220). No differences apart from chair time were observed when comparing DBBM and AB grafts with simultaneous implant placement in sinus elevation.

  19. Location and incidence of localized juxta-articular demineralizations and erosions at the wrist in early rheumatoid arthritis

    International Nuclear Information System (INIS)

    Fischer, E.

    1988-01-01

    In early rheumatoid arthritis the location and incidence of localized juxta-articular demineralizations and erosions were investigated at 53 points of the wrist. On the level of the metacarpal bases, the distal and proximal row of the carpal bones more changes are seen in the oblique vd. and the lateral view than in the dv. view. At the distal bones of the forearm more changes are seen at the radius than at the ulnar styloid. The most often changes at all occur at the volar middle third of the triquetrum in the oblique view and at the distal volar articular facet of the scaphoid in the lateral view. Close relations between localized juxta-articular demineralizations and erosions do not exist. If the early bone changes at the wrist in rheumatoid arthritis are to be detected additional oblique and lateral view are prerequisite. (orig.) [de

  20. Human alveolar bone cell proliferation, expression of osteoblastic phenotype, and matrix mineralization on porous titanium produced by powder metallurgy.

    Science.gov (United States)

    Rosa, Adalberto Luiz; Crippa, Grasiele Edilaine; de Oliveira, Paulo Tambasco; Taba, Mario; Lefebvre, Louis-Philippe; Beloti, Marcio Mateus

    2009-05-01

    This study aimed at investigating the influence of the porous titanium (Ti) structure on the osteogenic cell behaviour. Porous Ti discs were fabricated by the powder metallurgy process with the pore size typically between 50 and 400 microm and a porosity of 60%. Osteogenic cells obtained from human alveolar bone were cultured until subconfluence and subcultured on dense Ti (control) and porous Ti for periods of up to 17 days. Cultures grown on porous Ti exhibited increased cell proliferation and total protein content, and lower levels of alkaline phosphatase (ALP) activity than on dense Ti. In general, gene expression of osteoblastic markers-runt-related transcription factor 2, collagen type I, alkaline phosphatase, bone morphogenetic protein-7, and osteocalcin was lower at day 7 and higher at day 17 in cultures grown on porous Ti compared with dense Ti, a finding consistent with the enhanced growth rate for such cultures. The amount of mineralized matrix was greater on porous Ti compared with the dense one. These results indicate that the porous Ti is an appropriate substrate for osteogenic cell adhesion, proliferation, and production of a mineralized matrix. Because of the three-dimensional environment it provides, porous Ti should be considered an advantageous substrate for promoting desirable implant surface-bone interactions.

  1. Polarization sensitive optical coherence tomography in equine bone

    Science.gov (United States)

    Jacobs, J. W.; Matcher, S. J.

    2009-02-01

    Optical coherence tomography (OCT) has been used to image equine bone samples. OCT and polarization sensitive OCT (PS-OCT) images of equine bone samples, before and after demineralization, are presented. Using a novel approach, taking a series of images at different angles of illumination, the polar angle and true birefringence of collagen within the tissue is determined, at one site in the sample. The images were taken before and after the bones were passed through a demineralization process. The images show an improvement in depth penetration after demineralization allowing better visualization of the internal structure of the bone and the optical orientation of the collagen. A quantitative measurement of true birefringence has been made of the bone; true birefringence was shown to be 1.9x10-3 before demineralization increasing to 2.7x10-3 after demineralization. However, determined collagen fiber orientation remains the same before and after demineralization. The study of bone is extensive within the field of tissue engineering where an understanding of the internal structures is essential. OCT in bone, and improved depth penetration through demineralization, offers a useful approach to bone analysis.

  2. Self-assembled composite matrix in a hierarchical 3-D scaffold for bone tissue engineering

    DEFF Research Database (Denmark)

    Chen, Muwan; Le, Dang Quang Svend; Baatrup, Anette

    2011-01-01

    It is of high clinical relevance in bone tissue engineering that scaffolds promote a high seeding efficiency of cells capable of osteogenic differentiation, such as human bone marrow-derived mesenchymal stem cells (hMSCs). We evaluated the effects of a novel polycaprolactone (PCL) scaffold on h...

  3. Elastic intramedullary nailing and DBM-Bone marrow injection for the treatment of simple bone cysts

    Science.gov (United States)

    Kanellopoulos, Anastasios D; Mavrogenis, Andreas F; Papagelopoulos, Panayiotis J; Soucacos, Panayotis N

    2007-01-01

    Background Simple or unicameral bone cysts are common benign fluid-filled lesions usually located at the long bones of children before skeletal maturity. Methods We performed demineralized bone matrix and iliac crest bone marrow injection combined with elastic intramedullary nailing for the treatment of simple bone cysts in long bones of 9 children with a mean age of 12.6 years (range, 4 to 15 years). Results Two of the 9 patients presented with a pathological fracture. Three patients had been referred after the failure of previous treatments. Four patients had large lesions with impending pathological fractures that interfered with daily living activities. We employed a ratio to ascertain the severity of the lesion. The extent of the lesion on the longitudinal axis was divided with the normal expected diameter of the long bone at the site of the lesion. The mean follow-up was 77 months (range, 5 to 8 years). All patients were pain free and had full range of motion of the adjacent joints at 6 weeks postoperatively. Review radiographs showed that all 7 cysts had consolidated completely (Neer stage I) and 2 cysts had consolidated partially (Neer stage II). Until the latest examination there was no evidence of fracture or re-fracture. Conclusion Elastic intramedullary nailing has the twofold benefits of continuous cyst decompression, and early immediate stability to the involved bone segment, which permits early mobilization and return to the normal activities of the pre-teen patients. PMID:17916249

  4. Elastic intramedullary nailing and DBM-Bone marrow injection for the treatment of simple bone cysts

    Directory of Open Access Journals (Sweden)

    Papagelopoulos Panayiotis J

    2007-10-01

    Full Text Available Abstract Background Simple or unicameral bone cysts are common benign fluid-filled lesions usually located at the long bones of children before skeletal maturity. Methods We performed demineralized bone matrix and iliac crest bone marrow injection combined with elastic intramedullary nailing for the treatment of simple bone cysts in long bones of 9 children with a mean age of 12.6 years (range, 4 to 15 years. Results Two of the 9 patients presented with a pathological fracture. Three patients had been referred after the failure of previous treatments. Four patients had large lesions with impending pathological fractures that interfered with daily living activities. We employed a ratio to ascertain the severity of the lesion. The extent of the lesion on the longitudinal axis was divided with the normal expected diameter of the long bone at the site of the lesion. The mean follow-up was 77 months (range, 5 to 8 years. All patients were pain free and had full range of motion of the adjacent joints at 6 weeks postoperatively. Review radiographs showed that all 7 cysts had consolidated completely (Neer stage I and 2 cysts had consolidated partially (Neer stage II. Until the latest examination there was no evidence of fracture or re-fracture. Conclusion Elastic intramedullary nailing has the twofold benefits of continuous cyst decompression, and early immediate stability to the involved bone segment, which permits early mobilization and return to the normal activities of the pre-teen patients.

  5. Porous titanium scaffolds with injectable hyaluronic acid-DBM gel for bone substitution in a rat critical-sized calvarial defect model.

    Science.gov (United States)

    van Houdt, C I A; Cardoso, D A; van Oirschot, B A J A; Ulrich, D J O; Jansen, J A; Leeuwenburgh, S C G; van den Beucken, J J J P

    2017-09-01

    Demineralized bone matrix (DBM) is an allograft bone substitute used for bone repair surgery to overcome drawbacks of autologous bone grafting, such as limited supply and donor-site comorbidities. In view of different demineralization treatments to obtain DBM, we examined the biological performance of two differently demineralized types of DBM, i.e. by acidic treatment using hydrochloric acid (HCl) or treatment with the chelating agent ethylene diamine tetra-acetate (EDTA). First, we evaluated the osteo-inductive properties of both DBMs by implanting the materials subcutaneously in rats. Second, we evaluated the effects on bone formation by incorporating DBM in a hyaluronic acid (HA) gel to fill a porous titanium scaffold for use in a critical-sized calvarial defect model in 36 male Wistar rats. These porous titanium scaffolds were implanted empty or filled with HA gel containing either DBM HCl or DBM EDTA. Ectopically implanted DBM HCl and DBM EDTA did not induce ectopic bone formation over the course of 12 weeks. For the calvarial defects, mean percentages of newly formed bone at 2 weeks were significantly higher for Ti-Empty compared to Ti-HA + DBM HCl , but not compared to Ti-HA + DBM EDTA. Significant temporal bone formation was observed for Ti-Empty and Ti-HA + DBM HCl, but not for Ti-HA + DBM EDTA. At 8 weeks there were no significant differences in values of bone formation between the three experimental constructs. In conclusion, these results showed that, under the current experimental conditions, neither DBM HCl nor DBM EDTA possess osteo-inductive properties. Additionally, in combination with an HA gel loaded in a porous titanium scaffold, DBM HCl and DBM EDTA showed similar amounts of new bone formation after 8 weeks, which were lower than using the empty porous titanium scaffold. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Increased serum cartilage oligomeric matrix protein levels and decreased patellar bone mineral density in patients with chondromalacia patellae.

    Science.gov (United States)

    Murphy, E; FitzGerald, O; Saxne, T; Bresnihan, B

    2002-11-01

    Chondromalacia patellae is a potentially disabling disorder characterised by features of patellar cartilage degradation. To evaluate markers of cartilage and bone turnover in patients with chondromalacia patellae. 18 patients with chondromalacia patellae were studied. Serum cartilage oligomeric matrix protein (s-COMP) and bone sialoprotein (s-BSP) levels were measured by enzyme linked immunosorbent assay (ELISA) and compared with those of age and sex matched healthy control subjects. Periarticular bone mineral density (BMD) of both knee joints was assessed by dual energy x ray absorptiometry (DXA). s-COMP levels were significantly raised in all patients with chondromalacia patellae compared with healthy control subjects (p=0.0001). s-BSP levels did not differ significantly between the groups (p=0.41). BMD of the patella was significantly reduced in patients with chondromalacia patellae compared with the control subjects (p=0.016). In patients with bilateral chondromalacia patellae, BMD of the patella was lower in the more symptomatic knee joint (p=0.005). Changes in periarticular BMD were localised to the patella and were not present in femoral regions. Neither s-COMP (p=0.18) nor s-BSP (p=0.40) levels correlated with patellar BMD. Increased s-COMP levels, reflecting cartilage degradation, and reduced BMD localised to the patella may represent clinically useful markers in the diagnosis and monitoring of patients with chondromalacia patellae. Measures of cartilage degradation did not correlate with loss of patellar bone density, suggesting dissociated pathophysiological mechanisms.

  7. Reconstitution of bone-like matrix in osteogenically differentiated mesenchymal stem cell–collagen constructs: A three-dimensional in vitro model to study hematopoietic stem cell niche

    Directory of Open Access Journals (Sweden)

    WY Lai

    2013-10-01

    Full Text Available Mesenchymal stem/stromal cells (MSCs and osteoblasts are important niche cells for hematopoietic stem cells (HSCs in bone marrow osteoblastic niche. Here, we aim to partially reconstitute the bone marrow HSC niche in vitro using collagen microencapsulation for investigation of the interactions between HSCs and MSCs. Mouse MSCs (mMSCs microencapsulated in collagen were osteogenically differentiated to derive a bone-like matrix consisting of osteocalcin, osteopontin, and calcium deposits and secreted bone morphogenic protein 2 (BMP2. Decellularized bone-like matrix was seeded with fluorescence-labeled human MSCs and HSCs. Comparing with pure collagen scaffold, significantly more HSCs and HSC–MSC pairs per unit area were found in the decellularized bone-like matrix. Moreover, incubation with excess neutralizing antibody of BMP2 resulted in a significantly higher number of HSC per unit area than that without in the decellularized matrix. This work suggests that the osteogenic differentiated MSC–collagen microsphere is a valuable three-dimensional in vitro model to elucidate cell–cell and cell–matrix interactions in HSC niche.

  8. Construction of human induced pluripotent stem cell-derived oriented bone matrix microstructure by using in vitro engineered anisotropic culture model.

    Science.gov (United States)

    Ozasa, Ryosuke; Matsugaki, Aira; Isobe, Yoshihiro; Saku, Taro; Yun, Hui-Suk; Nakano, Takayoshi

    2018-02-01

    Bone tissue has anisotropic microstructure based on collagen/biological apatite orientation, which plays essential roles in the mechanical and biological functions of bone. However, obtaining an appropriate anisotropic microstructure during the bone regeneration process remains a great challenging. A powerful strategy for the control of both differentiation and structural development of newly-formed bone is required in bone tissue engineering, in order to realize functional bone tissue regeneration. In this study, we developed a novel anisotropic culture model by combining human induced pluripotent stem cells (hiPSCs) and artificially-controlled oriented collagen scaffold. The oriented collagen scaffold allowed hiPSCs-derived osteoblast alignment and further construction of anisotropic bone matrix which mimics the bone tissue microstructure. To the best of our knowledge, this is the first report showing the construction of bone mimetic anisotropic bone matrix microstructure from hiPSCs. Moreover, we demonstrated for the first time that the hiPSCs-derived osteoblasts possess a high level of intact functionality to regulate cell alignment. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 360-369, 2018. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc.

  9. Differential expression pattern of extracellular matrix molecules during chondrogenesis of mesenchymal stem cells from bone marrow and adipose tissue

    DEFF Research Database (Denmark)

    Mehlhorn, A T; Niemeyer, P; Kaiser, S

    2006-01-01

    Adipose-derived adult stem cells (ADASCs) or bone marrow-derived mesenchymal stem cells (BMSCs) are considered as alternative cell sources for cell-based cartilage repair due to their ability to produce cartilage-specific matrix. This article addresses the differential expression pattern...... chondroinduction. TGF-beta1 induces alternative splicing of the alpha(1)-procollagen type II transcript in BMSCs, but not in ADASCs. These findings may direct the development of a cell-specific culture environment either to prevent hypertrophy in BMSCs or to promote chondrogenic maturation in ADASCs....

  10. Fourier transform infrared imaging microspectroscopy and tissue-level mechanical testing reveal intraspecies variation in mouse bone mineral and matrix composition.

    Science.gov (United States)

    Courtland, Hayden-William; Nasser, Philip; Goldstone, Andrew B; Spevak, Lyudmila; Boskey, Adele L; Jepsen, Karl J

    2008-11-01

    Fracture susceptibility is heritable and dependent upon bone morphology and quality. However, studies of bone quality are typically overshadowed by emphasis on bone geometry and bone mineral density. Given that differences in mineral and matrix composition exist in a variety of species, we hypothesized that genetic variation in bone quality and tissue-level mechanical properties would also exist within species. Sixteen-week-old female A/J, C57BL/6J (B6), and C3H/HeJ (C3H) inbred mouse femora were analyzed using Fourier transform infrared imaging and tissue-level mechanical testing for variation in mineral composition, mineral maturity, collagen cross-link ratio, and tissue-level mechanical properties. A/J femora had an increased mineral-to-matrix ratio compared to B6. The C3H mineral-to-matrix ratio was intermediate of A/J and B6. C3H femora had reduced acid phosphate and carbonate levels and an increased collagen cross-link ratio compared to A/J and B6. Modulus values paralleled mineral-to-matrix values, with A/J femora being the most stiff, B6 being the least stiff, and C3H having intermediate stiffness. In addition, work-to-failure varied among the strains, with the highly mineralized and brittle A/J femora performing the least amount of work-to-failure. Inbred mice are therefore able to differentially modulate the composition of their bone mineral and the maturity of their bone matrix in conjunction with tissue-level mechanical properties. These results suggest that specific combinations of bone quality and morphological traits are genetically regulated such that mechanically functional bones can be constructed in different ways.

  11. INFLUENCE OF THE SKELETON HIERARCHICAL ORGANIZATION ON ELECTRONIC STATE OF IONS IN BONE MATRIX

    Directory of Open Access Journals (Sweden)

    A. S. Avrunin

    2016-01-01

    Full Text Available The authors suggested the 3D-superlattice (3DSL model to describe the effect of coplanar assembly of the hydroxyapatite (HA nanocrystallites on local electronic state of ions in mineralized bone. This model is based on the main structural and functional relationships between adjacent levels of the hierarchical organization of bone tissue. In the framework of the 3DSL model the authors predicted the distinct assembly-to-crystal red shift of the unoccupied electronic states located near the bottom of the conduction band in HA and dependence of this shift on the ratio of the thickness of the hydrated layer to the crystallite size. To check these predictions the experimental X-ray absorption studies of native bone are performed near the Ca2р1/2,3/2-, P2р1/2,3/2- и O1s edges. Comparison of the measured spectra with the known spectra of the reference compounds has confirmed appearance of the distinct assembly-to-crystal red shift. The observed effect is the ground for development of new diagnostic methods for bone status and imaging changes in the local electronic structure of bone tissue by using ultrasoft X-ray absorption spectroscopy and measuring the assembly-tocrystal shifts. The experimental data analysis proved the applicability of the 3DSL model for better understanding of the hierarchical organization of bone at nanolevel.

  12. Intraoperative fat embolism during core decompression and bone grafting for osteonecrosis of the hip: report of 3 cases and literature review.

    Science.gov (United States)

    Schaffer, Joseph Christopher; Adib, Farshad; Cui, Quanjun

    2014-06-01

    Osteonecrosis (ON) of the femoral head, without timely intervention, often progresses to debilitating hip arthritis. Core decompression (CD) with bone grafting was used to treat patients with early-stage ON. In 3 cases, intraoperative oxygen saturation, end-tidal carbon dioxide fluctuations, and/or vital sign fluctuations were observed during insertion of the graft, a mixture of bone marrow and demineralized bone matrix. In 1 case, continued postoperative pulmonary symptoms required admission to intensive care. In this article, we describe these cases and provide supporting evidence that they were caused by fat emboli secondary to forceful insertion of bone graft. We review the literature and present complications data. Although no cases of fat emboli were reported as complications of any CD series with or without bone grafting, CD augmented with bone graft may carry risks not seen before in CD alone. Care should be taken to avoid these complications, possibly through technique modification.

  13. Effects of odanacatib on bone matrix mineralization in rhesus monkeys are similar to those of alendronate

    Directory of Open Access Journals (Sweden)

    Barbara M. Misof

    2016-12-01

    Full Text Available Odanacatib (ODN is a selective and reversible inhibitor of cathepsin K which is an important enzyme for the degradation of collagen I. Aim of the present work was the head-to-head comparison between the effects of ODN and alendronate (ALN on bone mineralization density distribution (BMDD, based on quantitative backscattered electron imaging in relation to changes in histomorphometric mineralizing surface per bone surface (MS/BS in 12–22 years old ovariectomized rhesus monkeys. Trabecular and cortical BMDD derived parameters from vertebrae and proximal tibiae were compared among vehicle (VEH, n = 8, odanacatib low dose (ODN-L, n = 8, odanacatib high dose (ODN-H, n = 8, and alendronate (ALN, n = 6 treated animals. Additionally, data from an intact, non-treated group of animals are shown (INT, n = 8. In trabecular bone from the vertebra and metaphyseal tibia, the BMDD of the ODN and ALN treatment groups was shifted toward higher mineralization densities (p < 0.001 consistent with the significant reduction of MS/BS (p < 0.05 in ODN-H and ALN compared to VEH. Vertebral trabecular CaMean (average degree of mineralization was significantly higher in ODN-L (+6.5%, ODN-H (+6.1%, and ALN (+6.7%, all p < 0.001. Tibial osteonal cortical bone revealed also significantly increased CaMean for ODN-L (+1.4%, p < 0.05, ODN-H (+2.2%, p < 0.05, and ALN (+3.4%, p < 0.001 versus VEH, while primary cortical bone (devoid of secondary osteons did not show any significant differences between the study groups. The percentage of primary bone area in the tibial cross-sections (on average 45 ± 12% was also not significantly different between the study groups (p = 0.232. No significant differences in any BMDD parameters of all studied skeletal sites between ODN and ALN treatment were found. Correlation analysis revealed that MS/BS was highly predictive for trabecular BMDD in vertebral bone. The higher MS/BS, the lower was CaMean. Our findings are

  14. Alteration of the bone tissue material properties in type 1 diabetes mellitus: A Fourier transform infrared microspectroscopy study.

    Science.gov (United States)

    Mieczkowska, Aleksandra; Mansur, Sity Aishah; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume

    2015-07-01

    Type 1 diabetes mellitus (T1DM) is a severe disorder characterized by hyperglycemia and hypoinsulinemia. A higher occurrence of bone fractures has been reported in T1DM, and although bone mineral density is reduced in this disorder, it is also thought that bone quality may be altered in this chronic pathology. Vibrational microscopies such as Fourier transform infrared microspectroscopy (FTIRM) represent an interesting approach to study bone quality as they allow investigation of the collagen and mineral compartment of the extracellular matrix in a specific bone location. However, as spectral feature arising from the mineral may overlap with those of the organic component, the demineralization of bone sections should be performed for a full investigation of the organic matrix. The aims of the present study were to (i) develop a new approach, based on the demineralization of thin bone tissue section to allow a better characterization of the bone organic component by FTIRM, (ii) to validate collagen glycation and collagen integrity in bone tissue and (iii) to better understand what alterations of tissue material properties in newly forming bone occur in T1DM. The streptozotocin-injected mouse (150 mg/kg body weight, injected at 8 weeks old) was used as T1DM model. Animals were randomly allocated to control (n = 8) or diabetic (n = 10) groups and were sacrificed 4 weeks post-STZ injection. Bones were collected at necropsy, embedded in polymethylmethacrylate and sectioned prior to examination by FTIRM. FTIRM collagen parameters were collagen maturity (area ratio between 1660 and 1690 cm(-1) subbands), collagen glycation (area ratio between the 1032 cm(-1) subband and amide I) and collagen integrity (area ratio between the 1338 cm(-1) subband and amide II). No significant differences in the mineral compartment of the bone matrix could be observed between controls and STZ-injected animals. On the other hand, as compared with controls, STZ-injected animals presented with

  15. Identification of proteinaceous material in the bone of the dinosaur Iguanodon.

    Science.gov (United States)

    Embery, Graham; Milner, Angela C; Waddington, Rachel J; Hall, Rachel C; Langley, Martin S; Milan, Anna M

    2003-01-01

    This study has directed attention at the search for bone-related proteins in an extract of demineralized rib bone of the 120 mya Iguanodon. The inner compact bone was demineralized and the GuCl extract resolved into 11 fractions using anion exchange chromatography, which all contained silver-reactive proteins with various amino acid profiles. Two specific fractions, iv and xi, revealed characteristics typical of contemporary phosphoproteins and proteoglycans, respectively. Fraction iv, 43-57 kDa, contained a high ratio of aspartate and serine, although no phosphate was discernable. Fraction xi contained a band of 41-47 kDa and was rich in chondroitin sulphate and hyaluronan. In addition an early eluting fraction was immunoreactive with an antibody against osteocalcin. A cancellous bone fraction from the same bone sample was also analyzed using N-terminal sequencing and revealed potential similarities with cystatin. While we do not claim to have identified the presence of intact proteins, this study has value in demonstrating that extruded extracellular matrix is protected by its capacity to induce mineralization, which subsequently is important in conserving detectable protein products in ancient skeletal tissues.

  16. Demineralization of drinking water: Is it prudent?

    Science.gov (United States)

    Verma, K C; Kushwaha, A S

    2014-10-01

    Water is the elixir of life. The requirement of water for very existence of life and preservation of health has driven man to devise methods for maintaining its purity and wholesomeness. The water can get contaminated, polluted and become a potential hazard to human health. Water in its purest form devoid of natural minerals can also be the other end of spectrum where health could be adversely affected. Limited availability of fresh water and increased requirements has led to an increased usage of personal, domestic and commercial methods of purification of water. Desalination of saline water where fresh water is in limited supply has led to development of the latest technology of reverse osmosis but is it going to be safe to use such demineralized water over a long duration needs to be debated and discussed.

  17. Optimal reduction of humus in demineralization

    International Nuclear Information System (INIS)

    Persson, F.

    1989-04-01

    To have an optimal reduction of organic substance and colloids in a demineralization plant the following ought to be observed. * At least two anion exchangers should be in series. The firs one being either a weak macroporous polystyrene anion exchanger or a weak polyacrylic anion exchanger. A third anion exchanger in series improves the reduction only marginally. * The leakage of organic substance and colloids increases rapidly at the same time or before the leakage of anions. The anion exchangers in a plant should therefore have a higher capacity than the cation exchangers. If the anion exchangers do not have a higher capacity than the cation exchangers only 90-95 % of the capacity shall be used. * The filtration rates have normally no influence of the reduction organic of substance. Sometime a low filtration rate gives a better reduction of colloids. * The content of organic substance in the water to the plants has a great effect on the capacity for ions. At high content of organic substance (20 mg KMnO 4 ) the capacity for ions can be reduced with 30-40 %. * Different technics for regenerations does not seem to have any influence on the reduction of organic substances and colloids. Neither age of the anion exchangers nor washing with solutions of sodium chloride seems to have any influence on the reduction. Age and organic contamination have mainly an influence on the capacity per regeneration. At all demineralization plants some organic substances and colloids leak through the plant, the quantities depending on the colloids. To remove this organic substances and colloids the ion exchangers must be completed with for instance flocculation or reverse osmosis. (L.E.)

  18. Synthesis and characterization of a nanostructured matrix hydroxyapatite ceramic bone reconstruction

    International Nuclear Information System (INIS)

    Correa, P.; Camargo, N.H.A.; Silva, D.F.

    2012-01-01

    The nanostructured ceramics have been shown promise as biomaterials for bone reconstruction. Among calcium phosphates, hydroxyapatite Ca/P ratio = 1.67 mol stands out because of its crystallographic similarity with the mineral bone phase and biocompatibility. This work was based on synthesis and characterization of a nanostructured hydroxyapatite for use in reconstituting bone tissue. The synthesis method for obtaining the bioceramic powder occurred at process of dissolution/precipitation, involving CaO solid/liquid and phosphoric acid required for forming the composition of Ca/P = 1.67 mole. The material recovered from the synthesis was calcined at 900 ° C/2h, providing the hydroxyapatite powder nanometer. This was subjected to mechanical fragmentation process in mill attritor, providing a hydroxyapatite with modified surface morphology. The results presented relate to morphological characterization studies (SEM), mineralogical (XRD), chemical (FTIR) and particle size distribution, using the laser particle size analysis method. Such results showed the formation of hydroxyapatite phase and morphology satisfactory for use in reconstituting bone tissue

  19. [An in vitro method for studying the metabolism of young bone matrix].

    Science.gov (United States)

    Bonneton, C; Guest, M; Delbarre, F

    1977-07-04

    A method for studying in vitro bone resorption by the use of 35S labeled injection was investigated. Various substances (papaine) and hormones (calcitonin, vitamin D analogues) were tested and their effects on 35S and 45Ca metabolism were compared.

  20. Advanced bredigite-containing magnesium-matrix composites for biodegradable bone implant applications

    NARCIS (Netherlands)

    Naddaf Dezfuli, S.; Huan, Z.; Mol, J.M.C.; Leeflang, M.A.; Chang, Jiang; Zhou, J.

    2017-01-01

    The present research was aimed at developing magnesium-matrix composites that could allow effective control over their physiochemical and mechanical responses when in contact with physiological solutions. A biodegradable, bioactive ceramic - bredigite was chosen as the reinforcing phase in the

  1. Matrix elasticity of void-forming hydrogels controls transplanted-stem-cell-mediated bone formation

    Science.gov (United States)

    Huebsch, Nathaniel; Lippens, Evi; Lee, Kangwon; Mehta, Manav; Koshy, Sandeep T.; Darnell, Max C.; Desai, Rajiv M.; Madl, Christopher M.; Xu, Maria; Zhao, Xuanhe; Chaudhuri, Ovijit; Verbeke, Catia; Kim, Woo Seob; Alim, Karen; Mammoto, Akiko; Ingber, Donald E.; Duda, Georg N.; Mooney, David J.

    2015-12-01

    The effectiveness of stem cell therapies has been hampered by cell death and limited control over fate. These problems can be partially circumvented by using macroporous biomaterials that improve the survival of transplanted stem cells and provide molecular cues to direct cell phenotype. Stem cell behaviour can also be controlled in vitro by manipulating the elasticity of both porous and non-porous materials, yet translation to therapeutic processes in vivo remains elusive. Here, by developing injectable, void-forming hydrogels that decouple pore formation from elasticity, we show that mesenchymal stem cell (MSC) osteogenesis in vitro, and cell deployment in vitro and in vivo, can be controlled by modifying, respectively, the hydrogel’s elastic modulus or its chemistry. When the hydrogels were used to transplant MSCs, the hydrogel’s elasticity regulated bone regeneration, with optimal bone formation at 60 kPa. Our findings show that biophysical cues can be harnessed to direct therapeutic stem cell behaviours in situ.

  2. Evaluation of radiotherapy and chemotherapy effects in bone matrix using X-ray microfluorescence

    International Nuclear Information System (INIS)

    Andrade, C.B.V.; Salata, C.; Silva, C.M.

    2014-01-01

    Premenopausal women undergoing adjuvant chemotherapy and/or radiotherapy for Breast Cancer (BC) treatment have significant bone loss. This high bone mineral density loss can lead to an increased risk of fractures. In this study, there were evaluated parameters involved in osteoporosis when rats were subjected to a chemotherapy regimen (TC) and/or irradiation (IR). Female Wistar rats were divided into 3 groups: control (G1), TC+IR (G2) and IR (G3). The animals were euthanized after 5 months at the end of treatment and their femurs were excised and dissected. Sections of 10 μm thick were used for μXRF analysis at the National Laboratory of Synchrotron Light. The uteri of these rats were collected and weighed. The obtained results showed that animals from G2 had a significant reduction (p<0.05) of uterine mass when compared to control. The qualitative analysis performed by μXRF showed that animals from G2 had iron in bone composition of the femurs. This same result was notobserved in animals from G1 and G3 groups. These results suggest that early menopause occurs and osteoporosis begins, probably because of the absence, or reduced, production of estrogen. The presence of iron in the G2 samples in indicates the process of osteoporosis, because according to literature, this ion is competitive with calcium ions. - Highlights: • Premenopausal women undergoing Breast Cancer treatment have significant bone mineral density loss. • Animals submitted to Breast Cancer treatment have their uteri mass decreased. • The µXRF can detect differences in Iron concentration patterns between rats treated, and not treated, with chemotherapy. • Breast Cancer treatment changes the concentration of estrogens, increasing the chances of developing osteoporosis

  3. In vitro and in vivo investigations on bone regeneration potential of laminated hydroxyapatite/gelatin nanocomposite scaffold along with DBM

    Energy Technology Data Exchange (ETDEWEB)

    Tavakol, Shima [School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Department of Medical Nanotechnology (Iran, Islamic Republic of); Ragerdi Kashani, Iraj [School of Medicine, Tehran University of Medical Sciences, Department of Anatomy (Iran, Islamic Republic of); Azami, Mahmood [School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Department of Tissue Engineering (Iran, Islamic Republic of); Khoshzaban, Ahad [Tehran University of Medical Sciences, Iranian Tissue Bank Research and Preparation Center (Iran, Islamic Republic of); Tavakol, Behnaz [Kashan University of Medical Sciences, Department of Medicine (Iran, Islamic Republic of); Kharrazi, Sharmin [School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Department of Medical Nanotechnology (Iran, Islamic Republic of); Ebrahimi, Somayeh [University of Tarbiat Moallem, Department of Biology, Faculty of Sciences (Iran, Islamic Republic of); Rezayat Sorkhabadi, Seyed Mahdi, E-mail: sh_tavakol@razi.tums.ac.ir [School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Department of Medical Nanotechnology (Iran, Islamic Republic of)

    2012-12-15

    Bone regeneration ability of a scaffold strongly depends on its structure and the size of its components. In this study, a nanostructured scaffold was designed for bone repair using nano hydroxyapatite (nHA) (8-16 nm Multiplication-Sign 50-80 nm) and gelatin (GEL) as main components. In vitro investigations of calcium matrix deposition and gene expression of the seeded cells for this scaffold, demineralized bone matrix (DBM), scaffold plus DBM, and the control group were carried out. Bone regeneration in rat calvarium with critical defect size after 1, 4, and 8 weeks post implantation was investigated. The calcium matrix depositions by the osteoblast and RUNX2, ALP, osteonectin, and osteocalcin gene expression in scaffold were more significant than in other groups. Histomorphometry analysis confirmed in vitro results. In vitro and in vivo bone regeneration were least in scaffold plus DBM group. Enhanced effects in scaffold could be attributed to the shape and size of nHA particles and good architecture of the scaffold. Reduction of bone regeneration might be due to tight bonding of BMPs and nHA particles in the third group. Results obtained from this study confirmed that nano-scale size of the main components and the scaffold architecture (pore diameter, interconnectivity pores, etc.) have significant effects on bone regeneration ability of the scaffold and are important parameters in designing a temporary bone substitute.

  4. In vitro and in vivo investigations on bone regeneration potential of laminated hydroxyapatite/gelatin nanocomposite scaffold along with DBM

    International Nuclear Information System (INIS)

    Tavakol, Shima; Ragerdi Kashani, Iraj; Azami, Mahmood; Khoshzaban, Ahad; Tavakol, Behnaz; Kharrazi, Sharmin; Ebrahimi, Somayeh; Rezayat Sorkhabadi, Seyed Mahdi

    2012-01-01

    Bone regeneration ability of a scaffold strongly depends on its structure and the size of its components. In this study, a nanostructured scaffold was designed for bone repair using nano hydroxyapatite (nHA) (8–16 nm × 50–80 nm) and gelatin (GEL) as main components. In vitro investigations of calcium matrix deposition and gene expression of the seeded cells for this scaffold, demineralized bone matrix (DBM), scaffold plus DBM, and the control group were carried out. Bone regeneration in rat calvarium with critical defect size after 1, 4, and 8 weeks post implantation was investigated. The calcium matrix depositions by the osteoblast and RUNX2, ALP, osteonectin, and osteocalcin gene expression in scaffold were more significant than in other groups. Histomorphometry analysis confirmed in vitro results. In vitro and in vivo bone regeneration were least in scaffold plus DBM group. Enhanced effects in scaffold could be attributed to the shape and size of nHA particles and good architecture of the scaffold. Reduction of bone regeneration might be due to tight bonding of BMPs and nHA particles in the third group. Results obtained from this study confirmed that nano-scale size of the main components and the scaffold architecture (pore diameter, interconnectivity pores, etc.) have significant effects on bone regeneration ability of the scaffold and are important parameters in designing a temporary bone substitute.

  5. In situ biomimetic synthesis, characterization and in vitro investigation of bone-like nanohydroxyapatite in starch matrix

    Energy Technology Data Exchange (ETDEWEB)

    Sadjadi, M.S., E-mail: msadjad@gmail.com [Department of Chemistry, Science and Research Branch, Islamic Azad University, Poonak, Tehran (Iran, Islamic Republic of); Meskinfam, M. [Department of Chemistry, Science and Research Branch, Islamic Azad University, Poonak, Tehran (Iran, Islamic Republic of); Sadeghi, B. [Department of Chemistry, Tonekabon Branch, Islamic Azad university, Tonekabon (Iran, Islamic Republic of); Jazdarreh, H. [Department of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of); Zare, K. [Department of Chemistry, Faculty of Science, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2010-11-01

    In this work, we report the synthesis of bone-like hydroxyapatite (HAp) nanorods in wheat starch matrix via a biomimetic process. Characterization of the samples was performed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Scanning and transmission electron microscopy (SEM and TEM) were used to determine the size, shape and morphology of nano-HAp. The results indicate that, the shape and morphology of nHAp is influenced by the presence of starch as a template agent and rod-like nHAp similar to the inorganic component in the human body is obtained at room temperature. In vitro bioactivity of the synthesized HAp nanocomposites was finally verified by comparison of the HAp's structures and morphology before and after immersion in simulated body fluid (SBF) solution for 3, 7, and 14 days.

  6. Mechanical Loading Improves Tendon-Bone Healing in a Rabbit Anterior Cruciate Ligament Reconstruction Model by Promoting Proliferation and Matrix Formation of Mesenchymal Stem Cells and Tendon Cells

    Directory of Open Access Journals (Sweden)

    Fanglong Song

    2017-02-01

    Full Text Available Background/Aims: This study investigated the effect of mechanical stress on tendon-bone healing in a rabbit anterior cruciate ligament (ACL reconstruction model as well as cell proliferation and matrix formation in co-culture of bone-marrow mesenchymal stem cells (BMSCs and tendon cells (TCs. Methods: The effect of continuous passive motion (CPM therapy on tendon-bone healing in a rabbit ACL reconstruction model was evaluated by histological analysis, biomechanical testing and gene expressions at the tendon-bone interface. Furthermore, the effect of mechanical stretch on cell proliferation and matrix synthesis in BMSC/TC co-culture was also examined. Results: Postoperative CPM therapy significantly enhanced tendon-bone healing, as evidenced by increased amount of fibrocartilage, elevated ultimate load to failure levels, and up-regulated gene expressions of Collagen I, alkaline phosphatase, osteopontin, Tenascin C and tenomodulin at the tendon-bone junction. In addition, BMSC/TC co-culture treated with mechanical stretch showed a higher rate of cell proliferation and enhanced expressions of Collagen I, Collagen III, alkaline phosphatase, osteopontin, Tenascin C and tenomodulin than that of controls. Conclusion: These results demonstrated that proliferation and differentiation of local precursor cells could be enhanced by mechanical stimulation, which results in enhanced regenerative potential of BMSCs and TCs in tendon-bone healing.

  7. Outcome of nonunion fractures in dogs treated with fixation, compression resistant matrix, and recombinant human bone morphogenetic protein-2.

    Science.gov (United States)

    Massie, Anna M; Kapatkin, Amy S; Fuller, Mark C; Verstraete, Frank J M; Arzi, Boaz

    2017-03-20

    To report the use of compression resistant matrix (CRM) infused with recombinant human bone morphogenetic protein (rhBMP-2) prospectively in the healing of nonunion long-bone fractures in dogs. A longitudinal cohort of dogs that were presented with nonunion fractures were classified and treated with CRM soaked with rhBMP-2 and fracture fixation. They were followed with serial radiographs and evaluated for healing times and complications according to the time frame and definitions previously established for orthopaedic clinical cases. Eleven nonunion fractures in nine dogs were included. Median healing time was 10 weeks (range: 7-20 weeks). Major perioperative complications due to bandage morbidity were encountered in two of 11 limbs and resolved. All other complications were minor. They occurred perioperatively in eight of 11 limbs. Minor follow-up complications included short-term in one of two limbs, mid-term in one of three, and long-term in four of five limbs. Nine limbs returned to full function and two limbs returned to acceptable function at the last follow-up. Nonunion fractures given a poor prognosis via standard-of-care treatment were successfully repaired using CRM with rhBMP-2 accompanying fixation. These dogs, previously at high risk of failure, returned to full or acceptable function.

  8. Effects of cell-attachment and extracellular matrix on bone formation in vivo in collagen-hydroxyapatite scaffolds.

    Science.gov (United States)

    Villa, Max M; Wang, Liping; Rowe, David W; Wei, Mei

    2014-01-01

    Cell-based tissue engineering can be used to replace missing or damaged bone, but the optimal methods for delivering therapeutic cells to a bony defect have not yet been established. Using transgenic reporter cells as a donor source, two different collagen-hydroxyapatite (HA) scaffolds, and a critical-size calvarial defect model, we investigated the effect of a cell-attachment period prior to implantation, with or without an extracellular matrix-based seeding suspension, on cell engraftment and osteogenesis. When quantitatively compared, the in-house scaffold implanted immediately had a higher mean radiopacity than in-house scaffolds incubated overnight. Both scaffold types implanted immediately had significantly higher area fractions of donor cells, while the in-house collagen-HA scaffolds implanted immediately had higher area fractions of the mineralization label compared with groups incubated overnight. When the cell loading was compared in vitro for each delivery method using the in-house scaffold, immediate loading led to higher numbers of delivered cells. Immediate loading may be preferable in order to ensure robust bone formation in vivo. The use of a secondary ECM carrier improved the distribution of donor cells only when a pre-attachment period was applied. These results have improved our understanding of cell delivery to bony defects in the context of in vivo outcomes.

  9. Bone Mineral 31P and Matrix-Bound Water Densities Measured by Solid-State 1H and 31P MRI

    Science.gov (United States)

    Seifert, Alan C.; Li, Cheng; Rajapakse, Chamith S.; Bashoor- Zadeh, Mahdieh; Bhagat, Yusuf A.; Wright, Alexander C.; Zemel, Babette S.; Zavaliangos, Antonios; Wehrli, Felix W.

    2014-01-01

    Bone is a composite material consisting of mineral and hydrated collagen fractions. MRI of bone is challenging due to extremely short transverse relaxation times, but solid-state imaging sequences exist that can acquire the short-lived signal from bone tissue. Previous work to quantify bone density via MRI used powerful experimental scanners. This work seeks to establish the feasibility of MRI-based measurement on clinical scanners of bone mineral and collagen-bound water densities, the latter as a surrogate of matrix density, and to examine the associations of these parameters with porosity and donors’ age. Mineral and matrix-bound water images of reference phantoms and cortical bone from 16 human donors, ages 27-97 years, were acquired by zero-echo-time 31P and 1H MRI on whole body 7T and 3T scanners, respectively. Images were corrected for relaxation and RF inhomogeneity to obtain density maps. Cortical porosity was measured by micro-CT, and apparent mineral density by pQCT. MRI-derived densities were compared to x-ray-based measurements by least-squares regression. Mean bone mineral 31P density was 6.74±1.22 mol/L (corresponding to 1129±204 mg/cc mineral), and mean bound water 1H density was 31.3±4.2 mol/L (corresponding to 28.3±3.7 %v/v). Both 31P and bound water (BW) densities were correlated negatively with porosity (31P: R2 = 0.32, p bone mineralization ratio (expressed here as the ratio of 31P density to bound water density), which is proportional to true bone mineralization, was found to be uncorrelated with porosity, age, or pQCT density. This work establishes the feasibility of image-based quantification of bone mineral and bound water densities using clinical hardware. PMID:24846186

  10. Fragility Fracture Incidence in Chronic Obstructive Pulmonary Disease (COPD) Patients Associates With Nanoporosity, Mineral/Matrix Ratio, and Pyridinoline Content at Actively Bone-Forming Trabecular Surfaces.

    Science.gov (United States)

    Paschalis, Eleftherios P; Gamsjaeger, Sonja; Dempster, David; Jorgetti, Vanda; Borba, Victoria; Boguszewski, Cesar L; Klaushofer, Klaus; Moreira, Carolina A

    2017-01-01

    Chronic obstructive pulmonary disease (COPD) is associated with low areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) and altered microstructure by bone histomorphometry and micro-computed tomography. Nevertheless, not all COPD patients sustain fragility fractures. In the present study, we used Raman microspectroscopic analysis to determine bone compositional properties at actively forming trabecular surfaces (based on double fluorescent labels) in iliac crest biopsies from 19 postmenopausal COPD patients (aged 62.1 ± 7.3 years). Additionally, we analyzed trabecular geometrical centers, representing tissue much older than the forming surfaces. Eight of the patients had sustained fragility fractures, and 13 had received treatment with inhaled glucocorticoids. None of the patients had taken oral glucocorticoids. The monitored parameters were mineral/matrix ratio (MM), nanoporosity, and relative glycosaminoglycan (GAG), lipid, and pyridinoline contents (PYD). There were no significant differences between the glucocorticoid-treated patients and those who did not receive any. On the other hand, COPD patients sustaining fragility fractures had significantly lower nanoporosity and higher MM and PYD values compared with COPD patients without fragility fractures. To the best of our knowledge, this is the first study to discriminate between fracture and non-fracture COPD patients based on differences in the material properties of bone matrix. Given that these bone material compositional differences are evident close to the cement line (a major bone interface), they may contribute to the inferior bone toughness and coupled with the lower lumbar spine bone mineral density values result in the fragility fractures prevalent in these patients. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

  11. Raman and Fourier Transform Infrared (FT-IR) Mineral to Matrix Ratios Correlate with Physical Chemical Properties of Model Compounds and Native Bone Tissue.

    Science.gov (United States)

    Taylor, Erik A; Lloyd, Ashley A; Salazar-Lara, Carolina; Donnelly, Eve

    2017-10-01

    Raman and Fourier transform infrared (FT-IR) spectroscopic imaging techniques can be used to characterize bone composition. In this study, our objective was to validate the Raman mineral:matrix ratios (ν 1 PO 4 :amide III, ν 1 PO 4 :amide I, ν 1 PO 4 :Proline + hydroxyproline, ν 1 PO 4 :Phenylalanine, ν 1 PO 4 :δ CH 2 peak area ratios) by correlating them to ash fraction and the IR mineral:matrix ratio (ν 3 PO 4 :amide I peak area ratio) in chemical standards and native bone tissue. Chemical standards consisting of varying ratios of synthetic hydroxyapatite (HA) and collagen, as well as bone tissue from humans, sheep, and mice, were characterized with confocal Raman spectroscopy and FT-IR spectroscopy and gravimetric analysis. Raman and IR mineral:matrix ratio values from chemical standards increased reciprocally with ash fraction (Raman ν 1 PO 4 /Amide III: P Raman ν 1 PO 4 /Amide I: P Raman ν 1 PO 4 /Proline + Hydroxyproline: P Raman ν 1 PO 4 /Phenylalanine: P Raman ν 1 PO 4 /δ CH 2 : P Raman and IR mineral:matrix ratio values were strongly correlated ( P Raman mineral:matrix bone composition parameter correlates strongly to ash fraction and to its IR counterpart. Finally, the mineral:matrix ratio values of the native bone tissue are similar to those of both chemical standards and theoretical values, confirming the biological relevance of the chemical standards and the characterization techniques.

  12. Evaluation of radiotherapy and chemotherapy effects in bone matrix using X-ray microfluorescence

    Science.gov (United States)

    Andrade, C. B. V.; Salata, C.; Silva, C. M.; Ferreira-Machado, S. C.; Braz, D.; Almeida, A. P.; Nogueira, L. P.; Barroso, R. C.; deAlmeida, C. E.; Mantuano, A.; Mota, C. L.; Pickler, A.

    2014-02-01

    Premenopausal women undergoing adjuvant chemotherapy and/or radiotherapy for Breast Cancer (BC) treatment have significant bone loss. This high bone mineral density loss can lead to an increased risk of fractures. In this study, there were evaluated parameters involved in osteoporosis when rats were subjected to a chemotherapy regimen (TC) and/or irradiation (IR). Female Wistar rats were divided into 3 groups: control (G1), TC+IR (G2) and IR (G3). The animals were euthanized after 5 months at the end of treatment and their femurs were excised and dissected. Sections of 10 μm thick were used for μXRF analysis at the National Laboratory of Synchrotron Light. The uteri of these rats were collected and weighed. The obtained results showed that animals from G2 had a significant reduction (pbone composition of the femurs. This same result was notobserved in animals from G1 and G3 groups. These results suggest that early menopause occurs and osteoporosis begins, probably because of the absence, or reduced, production of estrogen. The presence of iron in the G2 samples in indicates the process of osteoporosis, because according to literature, this ion is competitive with calcium ions.

  13. Experimental study on the effect of x-irradiation in the rat bone matrix

    International Nuclear Information System (INIS)

    You, Dong Soo

    1979-01-01

    The author studied on the side effects of x-ray irradiation to the developing mandible of the gestation and period of grow the stage rats. For experimental observation, 100 rads, 200 rads, and 300 rads of x-ray were irradiated in regular order at the lower abdomen of the 8th day gestated rats. 5 weeks after conception, their offspring were sacrificed and their mandibles were extracted with intact form. All the extracted mandible were examined for their developing modes histological findings. The results were as followed; 1) In 10 -200 rads irradiated rats offsprings, their mandibles were not revealed any morphological changes except of the irregular pattern of trabeculatum. In accompany with this findings, most of all the fibroblasts and osteoclasts had their nucleus with shrunken and eccentric position. 2) In according to the increasing x-ray irradiation, marked advent of osteoclast and cortical bone remuamsorption were observed. 3) In 300 rads irradiated rats offsprings, there irregular pattern of trabeculae and widening of bone morrow cavity in their alveolar proper.

  14. Feasibility of autologous bone marrow mesenchymal stem cell-derived extracellular matrix scaffold for cartilage tissue engineering.

    Science.gov (United States)

    Tang, Cheng; Xu, Yan; Jin, Chengzhe; Min, Byoung-Hyun; Li, Zhiyong; Pei, Xuan; Wang, Liming

    2013-12-01

    Extracellular matrix (ECM) materials are widely used in cartilage tissue engineering. However, the current ECM materials are unsatisfactory for clinical practice as most of them are derived from allogenous or xenogenous tissue. This study was designed to develop a novel autologous ECM scaffold for cartilage tissue engineering. The autologous bone marrow mesenchymal stem cell-derived ECM (aBMSC-dECM) membrane was collected and fabricated into a three-dimensional porous scaffold via cross-linking and freeze-drying techniques. Articular chondrocytes were seeded into the aBMSC-dECM scaffold and atelocollagen scaffold, respectively. An in vitro culture and an in vivo implantation in nude mice model were performed to evaluate the influence on engineered cartilage. The current results showed that the aBMSC-dECM scaffold had a good microstructure and biocompatibility. After 4 weeks in vitro culture, the engineered cartilage in the aBMSC-dECM scaffold group formed thicker cartilage tissue with more homogeneous structure and higher expressions of cartilaginous gene and protein compared with the atelocollagen scaffold group. Furthermore, the engineered cartilage based on the aBMSC-dECM scaffold showed better cartilage formation in terms of volume and homogeneity, cartilage matrix content, and compressive modulus after 3 weeks in vivo implantation. These results indicated that the aBMSC-dECM scaffold could be a successful novel candidate scaffold for cartilage tissue engineering. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

  15. Low-power laser irradiation improves histomorphometrical parameters and bone matrix organization during tibia wound healing in rats.

    Science.gov (United States)

    Garavello-Freitas, I; Baranauskas, V; Joazeiro, P P; Padovani, C R; Dal Pai-Silva, M; da Cruz-Höfling, Maria Alice

    2003-01-01

    The influence of daily energy doses of 0.03, 0.3 and 0.9 J of He-Ne laser irradiation on the repair of surgically produced tibia damage was investigated in Wistar rats. Laser treatment was initiated 24 h after the trauma and continued daily for 7 or 14 days in two groups of nine rats (n=3 per laser dose and period). Two control groups (n=9 each) with injured tibiae were used. The course of healing was monitored using morphometrical analysis of the trabecular area. The organization of collagen fibers in the bone matrix and the histology of the tissue were evaluated using Picrosirius-polarization method and Masson's trichrome. After 7 days, there was a significant increase in the area of neoformed trabeculae in tibiae irradiated with 0.3 and 0.9 J compared to the controls. At a daily dose of 0.9 J (15 min of irradiation per day) the 7-day group showed a significant increase in trabecular bone growth compared to the 14-day group. However, the laser irradiation at the daily dose of 0.3 J produced no significant decrease in the trabecular area of the 14-day group compared to the 7-day group, but there was significant increase in the trabecular area of the 15-day controls compared to the 8-day controls. Irradiation increased the number of hypertrophic osteoclasts compared to non-irradiated injured tibiae (controls) on days 8 and 15. The Picrosirius-polarization method revealed bands of parallel collagen fibers (parallel-fibered bone) at the repair site of 14-day-irradiated tibiae, regardless of the dose. This organization improved when compared to 7-day-irradiated tibiae and control tibiae. These results show that low-level laser therapy stimulated the growth of the trabecular area and the concomitant invasion of osteoclasts during the first week, and hastened the organization of matrix collagen (parallel alignment of the fibers) in a second phase not seen in control, non-irradiated tibiae at the same period. The active osteoclasts that invaded the regenerating site were

  16. Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

    Energy Technology Data Exchange (ETDEWEB)

    Yunoki, Shunji [Life Science Group, Tokyo Metropolitan Industrial Technology Research Institute, 2-11-1 Fukasawa, Setagaya-ku, Tokyo 158-0081 (Japan); Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori [Department of Sports Medicine and Joint Surgery, Graduate School of Medicine, Hokkaido University, Kita-15 Nishi-7, Sapporo, Hokkaido 060-8638 Japan (Japan); Ikoma, Toshiyuki; Tanaka, Junzo, E-mail: yunoki.shunji@iri-tokyo.jp [Department of Metallurgy and Ceramics Science, 2-12-1-S7-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2011-02-15

    The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm{sup -3} and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 {+-} 0.48 and 0.651 {+-} 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

  17. Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

    International Nuclear Information System (INIS)

    Yunoki, Shunji; Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori; Ikoma, Toshiyuki; Tanaka, Junzo

    2011-01-01

    The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm -3 and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 ± 0.48 and 0.651 ± 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

  18. Biodegradable Thermogel as Culture Matrix of Bone Marrow Mesenchymal Stem Cells for Potential Cartilage Tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    Yan-bo Zhang; Jian-xun Ding; Wei-guo Xu; Jie Wu; Fei Chang; Xiu-li Zhuang; Xue-si Chen

    2014-01-01

    Poly(lactide-co-glycolide)-poly(ethylene glycol)-poly(lactide-co-glycolide) (PLGA-PEG-PLGA) triblock copolymer was synthesized through the ring-opening polymerization of LA and GA with PEG as macroinitiator and stannous octoate as catalyst.The amphiphilic copolymer self-assembled into micelles in aqueous solutions,and formed hydrogels as the increase of temperature at relatively high concentrations (> 15 wt%).The favorable degradability of the hydrogel was confirmed by in vitro and in vivo degradation experiments.The good cellular and tissular compatibilities of the thermogel were demonstrated.The excellent adhesion and proliferation of bone marrow mesenchymal stem cells endowed PLGA-PEG-PLGA thermogelling hydrogel with fascinating prospect for cartilage tissue engineering.

  19. Altered composition of bone as triggered by irradiation facilitates the rapid erosion of the matrix by both cellular and physicochemical processes.

    Directory of Open Access Journals (Sweden)

    Danielle E Green

    Full Text Available Radiation rapidly undermines trabecular architecture, a destructive process which proceeds despite a devastated cell population. In addition to the 'biologically orchestrated' resorption of the matrix by osteoclasts, physicochemical processes enabled by a damaged matrix may contribute to the rapid erosion of bone quality. 8w male C57BL/6 mice exposed to 5 Gy of Cs(137 γ-irradiation were compared to age-matched control at 2d, 10d, or 8w following exposure. By 10d, irradiation had led to significant loss of trabecular bone volume fraction. Assessed by reflection-based Fourier transform infrared imaging (FTIRI, chemical composition of the irradiated matrix indicated that mineralization had diminished at 2d by -4.3±4.8%, and at 10d by -5.8±3.2%. These data suggest that irradiation facilitates the dissolution of the matrix through a change in the material itself, a conclusion supported by a 13.7±4.5% increase in the elastic modulus as measured by nanoindentation. The decline in viable cells within the marrow of irradiated mice at 2d implies that the immediate collapse of bone quality and inherent increased risk of fracture is not solely a result of an overly-active biologic process, but one fostered by alterations in the material matrix that predisposes the material to erosion.

  20. Characterization of Bone Marrow Mononuclear Cells on Biomaterials for Bone Tissue Engineering In Vitro

    Science.gov (United States)

    Verboket, René; Kontradowitz, Kerstin; Oppermann, Elsie; Brune, Jan C.; Nau, Christoph; Meier, Simon; Bonig, Halvard; Marzi, Ingo; Seebach, Caroline

    2015-01-01

    Bone marrow mononuclear cells (BMCs) are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma), demineralized bone matrix (DBM), and bovine cancellous bone (BS) were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo. PMID:25802865

  1. Characterization of bone marrow mononuclear cells on biomaterials for bone tissue engineering in vitro.

    Science.gov (United States)

    Henrich, Dirk; Verboket, René; Schaible, Alexander; Kontradowitz, Kerstin; Oppermann, Elsie; Brune, Jan C; Nau, Christoph; Meier, Simon; Bonig, Halvard; Marzi, Ingo; Seebach, Caroline

    2015-01-01

    Bone marrow mononuclear cells (BMCs) are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma), demineralized bone matrix (DBM), and bovine cancellous bone (BS) were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo.

  2. Characterization of Bone Marrow Mononuclear Cells on Biomaterials for Bone Tissue Engineering In Vitro

    Directory of Open Access Journals (Sweden)

    Dirk Henrich

    2015-01-01

    Full Text Available Bone marrow mononuclear cells (BMCs are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma, demineralized bone matrix (DBM, and bovine cancellous bone (BS were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo.

  3. ROC analysis of acid demineralized artificial caries

    International Nuclear Information System (INIS)

    Kang, Byung Cheol

    1997-01-01

    This study is designed to determine the artificial incipient proximal caries lesion detectability by dentists on Ektaspeed Plus film using ROC analysis. Sixteen premolars and 30 molars, which have 52 proximal caries-like demineralized lesions using acid-gel technique were added to 20 sound premolars and 30 sound molars to make 24 plaster blocks. Each block with 4 teeth and 6 contacting proximal surfaces was placed in an optical bench to take 12 bitewing radiographs with Ektaspeed Plus film. Thirty-six dentists acted as observers to evaluated the proximal lesions using five rating scales for ROC analysis. They were also asked to determine the presence or absence of the proximal caries. The true status of the proximal caries was established by the consensus of three oral and maxillofacila radiologists. For evaluation of intra-observer agreement, 9 dentist reread the radiographs at an interval of 1 month. The Pearson correlation coefficient for the intra-observer agreement was 0.746 (good agreement). Ten observer's data set were degenerated. The mean area under ROC curve from 26 observers was 0.806 and standard deviation was 0.061. The sensitivity and the specificity of the binary response were 0.17 (SD=0.11) and 0.78 (SD=0.17) respectively. The binary response only reveal a single values of sensitivity and the specificity. The ROC analysis to assess the diagnostic accuracy in caries detection, which producing estimates of sensitivities for all specifities, yield more comprehensive measures of diagnostic performance than single values for sensitivity and specificity.

  4. A combined approach of enamel matrix derivative gel and autogenous bone grafts in treatment of intrabony periodontal defects. A case report.

    Science.gov (United States)

    Leung, George; Jin, Lijian

    2003-04-01

    Enamel matrix derivative (EMD) has recently been introduced as a new modality in regenerative periodontal therapy. This case report demonstrates a combined approach in topical application of EMD gel (Emdogain) and autogenous bone grafts for treatment of intrabony defects and furcation involvement defects in a patient with chronic periodontitis. The seven-month post-surgery clinical and radiographic results were presented. The combined application of EMD gel with autogenous bone grafts in intrabony osseous defects resulted in clinically significant gain of attachment on diseased root surfaces and bone fill on radiographs. Further controlled clinical studies are required to confirm the long-term effectiveness of the combination of EMD gel and autogenous bone grafts in treatment of various osseous defects in subjects with chronic periodontitis.

  5. Cost and radiation exposure optimization of demineralizer operation

    International Nuclear Information System (INIS)

    Bernal, F.E.; Burn, R.R.; Cook, G.M.; Simonetti, L.; Simpson, P.A.

    1985-01-01

    A pool water demineralizer is utilized at a research reactor to minimize impurities that become radioactive; to minimize impurities that react chemically with reactor components; to maintain optical clarity of the pool water; and to minimize aluminum fuel cladding corrosion by maintaining a slightly acidic pH. Balanced against these advantages are the dollar costs of equipment, resins, recharging chemicals, and maintenance; the man-rem costs of radiation exposure during maintenance, demineralizer recharges, and resin replacement; and hazardous chemical exposure. At the Ford Nuclear Reactor (FNR), maintenance of the demineralizer system is the second largest source of radiation exposure to operators. Theoretical and practical aspects of demineralizer operation are discussed. The most obvious way to reduce radiation exposure due to demineralizer system operation is to perform recharges after the reactor has been shut down for the maximum possible time. Setting a higher depletion limit and operating with the optimum system lineup reduce the frequency between recharges, saving both exposure and cost. Recharge frequency and resin lifetime seem to be relatively independent of the quality of the chemicals used and the personnel performing recharges, provided consistent procedures are followed

  6. Extrafibrillar collagen demineralization-based chelate-and-rinse technique bridges the gap between wet and dry dentin bonding.

    Science.gov (United States)

    Mai, Sui; Wei, Chin-Chuan; Gu, Li-Sha; Tian, Fu-Cong; Arola, Dwayne D; Chen, Ji-Hua; Jiao, Yang; Pashley, David H; Niu, Li-Na; Tay, Franklin R

    2017-07-15

    Limitations associated with wet-bonding led to the recent development of a selective demineralization strategy in which dentin was etched with a reduced concentration of phosphoric acid to create exclusive extrafibrillar demineralization of the collagen matrix. However, the use of acidic conditioners removes calcium via diffusion of very small hydronium ions into the intrafibrillar collagen water compartments. This defeats the purpose of limiting the conditioner to the extrafibrillar space to create a collagen matrix containing only intrafibrillar minerals to prevent collapse of the collagen matrix. The present work examined the use of polymeric chelators (the sodium salt of polyacrylic acid) of different molecular weights to selectively demineralize extrafibrillar dentin. These polymeric chelators exhibit different affinities for calcium ions (isothermal titration calorimetry), penetrated intrafibrillar dentin collagen to different extents based on their molecular sizes (modified size-exclusion chromatography), and preserve the dynamic mechanical properties of mineralized dentin more favorably compared with completely demineralized phosphoric acid-etched dentin (nanoscopical dynamic mechanical analysis). Scanning and transmission electron microscopy provided evidence for retention of intrafibrillar minerals in dentin surfaces conditioned with polymeric chelators. Microtensile bond strengths to wet-bonded and dry-bonded dentin conditioned with these polymeric chelators showed that the use of sodium salts of polyacrylic acid for chelating dentin prior to bonding did not result in significant decline in resin-dentin bond strength. Taken together, the findings led to the conclusion that a chelate-and-rinse conditioning technique based on extrafibrillar collagen demineralization bridges the gap between wet and dry dentin bonding. The chelate-and-rinse dental adhesive bonding concept differentiates from previous research in that it is based on the size

  7. Relative accretion of /sup 99m/Tc-polyphosphate by forming and resorbing bone systems in rats: its significance in the pathologic basis of bone scanning

    International Nuclear Information System (INIS)

    Garcia, D.A.; Tow, D.E.; Kapur, K.K.; Wells, H.

    1976-01-01

    The relative roles of osteogenesis and osteolysis in the production of positive radionuclide images of skeletal lesions were investigated. The uptake of /sup 99m/Tc-polyphosphate (Tc-PP) by each process was measured in an animal model that permitted bone formation and resorption to be studied independently. Ten rats received intramuscular implants of bone-forming demineralized matrix (DM) and resorbing devitalized bone (DV). Radiographs and Tc-PP scintiscans were made each week thereafter. At 6 to 10 weeks, the implants and normal bone samples were removed, counted for /sup 99m/Tc, and examined histologically. The uptake of Tc-PP by DM implants was first detected on images made 3 weeks after implantation, and by DV implants, 1 to 2 weeks later. Serial radiography showed progressive calcification of DM and resorption of DV implants. Microscopic examinations of undecalcified sections, stained with a modified Goldner preparation, revealed vital-bone formation in the DM implants and osteoclastic resorption in the DV. Activity counts per gram of DM and DV implants were, respectively, 200 percent and 90 percent that of normal bone. Since only the bone-forming system (DM) accumulated Tc-PP at greater than normal concentrations, this study indicates that positive bone images of osteolytic lesions solely reflect compensatory osteogenic responses

  8. Zymography of Hybrid Layers Created Using Extrafibrillar Demineralization.

    Science.gov (United States)

    Gu, L; Mazzoni, A; Gou, Y; Pucci, C; Breschi, L; Pashley, D H; Niu, L; Tay, F R

    2018-04-01

    A chelate-and-rinse extrafibrillar calcium chelation dentin bonding concept has recently been developed and investigated for its effectiveness in improving resin-dentin bonding by bridging the gap between wet and dry dentin bonding. The objective of the present study was to evaluate the gelatinolytic activity of hybrid layers (HLs) created using the chelate-and-rinse bonding technique. Gelatinolytic activity within the HL was examined using in situ zymography and confocal laser-scanning microscopy after 24-h storage or after thermomechanical cycling. Dentin specimens were bonded with Prime&Bond NT (Dentsply Sirona) after conditioning with 15 wt% phosphoric acid for 15 s (control) or 15 wt% polymeric chelators (sodium salt of polyacrylic acid; PAAN) of 2 different molecular weights for 60 s. For each reagent, bonding was performed using dry-bonding and wet-bonding techniques ( n = 10). Slices containing the adhesive-dentin interface were covered with fluorescein-conjugated gelatin and examined with a confocal laser-scanning microscope. Fluorescence intensity emitted by the hydrolyzed fluorescein-conjugated gelatin was quantified. Gelatinolytic activity was expressed as the percentage of green fluorescence emitted within the HL. After storage for 24 h, enzymatic activity was only detected within the completely demineralized phosphoric acid-etched dentin, with values derived from dry bonding higher than those from wet bonding ( P < 0.05). Almost no fluorescence signals were detected within the HL when dentin was conditioned with PAANs compared with the controls ( P < 0.05). After thermomechanical cycling, enzymatic activities significantly increased for the phosphoric acid-conditioned, drying-bonding group compared with 24-h storage ( P < 0.05). The present study showed that the use of the chelate-and-rinse bonding concept for both dry-bonding and wet-bonding approaches results in the near absence of matrix-bound collagenolytic activities in the HL even after aging

  9. Beyond the functional matrix hypothesis: a network null model of human skull growth for the formation of bone articulations.

    Science.gov (United States)

    Esteve-Altava, Borja; Rasskin-Gutman, Diego

    2014-09-01

    Craniofacial sutures and synchondroses form the boundaries among bones in the human skull, providing functional, developmental and evolutionary information. Bone articulations in the skull arise due to interactions between genetic regulatory mechanisms and epigenetic factors such as functional matrices (soft tissues and cranial cavities), which mediate bone growth. These matrices are largely acknowledged for their influence on shaping the bones of the skull; however, it is not fully understood to what extent functional matrices mediate the formation of bone articulations. Aiming to identify whether or not functional matrices are key developmental factors guiding the formation of bone articulations, we have built a network null model of the skull that simulates unconstrained bone growth. This null model predicts bone articulations that arise due to a process of bone growth that is uniform in rate, direction and timing. By comparing predicted articulations with the actual bone articulations of the human skull, we have identified which boundaries specifically need the presence of functional matrices for their formation. We show that functional matrices are necessary to connect facial bones, whereas an unconstrained bone growth is sufficient to connect non-facial bones. This finding challenges the role of the brain in the formation of boundaries between bones in the braincase without neglecting its effect on skull shape. Ultimately, our null model suggests where to look for modified developmental mechanisms promoting changes in bone growth patterns that could affect the development and evolution of the head skeleton. © 2014 Anatomical Society.

  10. Unicameral bone cyst: a retrospective study of three surgical treatments.

    Science.gov (United States)

    Sung, Anthony D; Anderson, Megan E; Zurakowski, David; Hornicek, Francis J; Gebhardt, Mark C

    2008-10-01

    Between 1979 and 2004, 167 patients younger than 20 years were treated surgically for humeral or femoral unicameral bone cysts with either injection of corticosteroids (steroids), curettage plus bone grafting (curettage), or a combination injection of steroids, demineralized bone matrix, and bone marrow aspirate (SDB) at Children's Hospital of Boston and Massachusetts General Hospital (mean followup, 7.3 years; range, 1 month-27 years). Outcomes included treatment failure (defined clinically as subsequent pathologic fracture or need for retreatment to prevent pathologic fracture) and complications. Information was obtained from medical records and by telephone questionnaire. After one treatment, 84% of cysts treated with steroids experienced failed treatment versus 64% with curettage and 50% with SDB. For unicameral bone cysts requiring retreatment (regardless of first treatment), 76% retreated with steroids had failed treatment versus 63% with curettage and 71% with SDB. Curettage was associated with the lowest rate of posttreatment pathologic fractures and highest rate of pain and other complications. Multivariate logistic regression indicated treatment with steroids alone and younger age were independent predictors of failure. We believe SDB is a reasonable first treatment for unicameral bone cysts in the humerus and femur in patients younger than 20 years, being less invasive yet comparable to curettage in preventing recurrence.

  11. Clinical assessment of demineralization and remineralization surrounding orthodontic brackets with FluoreCam

    Directory of Open Access Journals (Sweden)

    Bora Korkut

    2017-04-01

    Conclusions: This study demonstrated that demineralization is measurable around orthodontic brackets and the demineralization can be completely inhibited and/or reversed by the use of commercially available remineralization products.

  12. Bone Marrow-derived Myofibroblasts Are the Providers of Pro-invasive Matrix Metalloproteinase 13 in Primary Tumor

    Directory of Open Access Journals (Sweden)

    Julie Lecomte

    2012-10-01

    Full Text Available Carcinoma-associated fibroblasts are key contributors of the tumor microenvironment that regulates carcinoma progression. They consist of a heterogeneous cell population with diverse origins, phenotypes, and functions. In the present report, we have explored the contribution of bone marrow (BM-derived cells to generate different fibroblast subsets that putatively produce the matrix metalloproteinase 13 (MMP13 and affect cancer cell invasion. A murine model of skin carcinoma was applied to mice, irradiated, and engrafted with BM isolated from green fluorescent protein (GFP transgenic mice. We provide evidence that one third of BM-derived GFP+ cells infiltrating the tumor expressed the chondroitin sulfate proteoglycan NG2 (pericytic marker or α-smooth muscle actin (α-SMA, myofibroblast marker, whereas almost 90% of Thy1+ fibroblasts were originating from resident GFP-negative cells. MMP13producing cells were exclusively α-SMA+ cells and derived from GFP+ BM cells. To investigate their impact on tumor invasion, we isolated mesenchymal stem cells (MSCs from the BM of wild-type and MMP13-deficient mice. Wild-type MSC promoted cancer cell invasion in a spheroid assay, whereas MSCs obtained from MMP13-deficient mice failed to. Our data support the concept of fibroblast subset specialization with BM-derived α-SMA+ cells being the main source of MMP13, a stromal mediator of cancer cell invasion.

  13. Demineralization of Enamel in Primary Second Molars Related to Properties of the Enamel

    OpenAIRE

    Sabel, N.; Robertson, A.; Nietzsche, S.; Norén, J. G.

    2012-01-01

    Enamel structure is of importance in demineralization. Differences in porosity in enamel effect the rate of demineralization, seen between permanent and deciduous teeth. Individual differences have been shown in the mean mineral concentration values in enamel, the role of this in demineralization is not thoroughly investigated. The aim of this study was to study variations of depths of artificial lesions of demineralization and to analyze the depth in relation to variations in the chemical an...

  14. Effect of weightlessness on mineral saturation of bone tissue

    Science.gov (United States)

    Krasnykh, I. G.

    1975-01-01

    X-ray photometry of bone density established dynamic changes in mineral saturation of bone tissues for Soyuz spacecraft and Salyut orbital station crews. Calcaneus optical bone densities in all crew members fell below initial values; an increase in spacecrew exposure time to weightlessness conditions also increased the degree of decalcification. Demineralization under weightlessness conditions took place at a higher rate than under hypodynamia.

  15. Quantitative diagnosis of skeletons with demineralizing osteopathy

    International Nuclear Information System (INIS)

    Banzer, D.

    1979-01-01

    The quantitative diagnosis of bone diseases must be assessed according to the accuracy of the applied method, the expense in apparatus, personnel and financial resources and the comparability of results. Nuclide absorptiometry and in the future perhaps computed tomography represent the most accurate methods for determining the mineral content of bones. Their application is the clinics' prerogative because of the costs. Morphometry provides quantiative information, in particular in course control, and enables an objective judgement of visual pictures. It requires little expenditure and should be combined with microradioscopy. Direct comparability of the findings of different working groups is most easy in morphometry; it depends on the equipment in computerized tomography and is still hardly possible in nuclide absorptiometry. For fundamental physical reason, it will hardly be possible to produce a low-cost, fast and easy-to-handle instrument for the determination of the mineral salt concentration in bones. Instead, there is rather a trend towards more expensive equipment, e.g. CT instruments; the universal use of these instruments, however, will help to promote quantitative diagnoses. (orig.) [de

  16. Histologic Evaluation of Critical Size Defect Healing With Natural and Synthetic Bone Grafts in the Pigeon ( Columba livia ) Ulna.

    Science.gov (United States)

    Tunio, Ahmed; Jalila, Abu; Goh, Yong Meng; Shameha-Intan; Shanthi, Ganabadi

    2015-06-01

    Fracture and bone segment loss are major clinical problems in birds. Achieving bone formation and clinical union in a fracture case is important for the survival of the bird. To evaluate the efficacy of bone grafts for defect healing in birds, 2 different bone grafts were investigated in the healing of a bone defect in 24 healthy pigeons ( Columba livia ). In each bird, a 1-cm critical size defect (CSD) was created in the left ulna, and the fracture was stabilized with external skeletal fixation (ESF). A graft of hydroxyapatite (HA) alone (n = 12 birds) or demineralized bone matrix (DBM) combined with HA (n = 12 birds) was implanted in the CSD. The CSD healing was evaluated at 3 endpoints: 3, 6, and 12 weeks after surgery. Four birds were euthanatized at each endpoint from each treatment group, and bone graft healing in the ulna CSD was evaluated by histologic examination. The CSD and graft implants were evaluated for quality of union, cortex development, and bone graft incorporation. Results showed no graft rejection in any bird, and all birds had connective tissue formation in the defect because of the bone graft application. These results suggest that bone defect healing can be achieved by a combination of osteoinductive and osteoconductive bone graft materials for clinical union and new bone regeneration in birds. The combination of DBM and HA resulted in a better quality bone graft (P < .05) than did HA alone, but there was no significant differences in cortex development or bone graft incorporation at 3, 6, or 12 weeks. From the results of this study, we conclude that HA bone grafts, alone or in combination with DBM, with external skeletal fixation is suitable and safe for bone defect and fracture treatment in pigeons.

  17. Penetration of varnishes into demineralized root dentine in vitro

    NARCIS (Netherlands)

    Arends, J; Duschner, H; Ruben, JL

    1997-01-01

    In this paper the penetration of three different varnishes employed in caries prevention (Duraphat(R), Fluor Protector(R) and Cervitec(R)) into demineralized dentine is quantified using confocal laser scanning microscopy. The results show that the varnish penetration into lesions about 85 mu m in

  18. Staining of dentin from amalgam corrosion is induced by demineralization

    NARCIS (Netherlands)

    Scholtanus, J.D.; van der Hoorn, W.; Özcan, M.; Huysmans, M.C.D.N.J.M.; Roeters, J.F.M.; Kleverlaan, C.J.; Feilzer, A.J.

    2013-01-01

    PURPOSE: To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam. METHODS: Sound human molars (n = 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n

  19. Staining of dentin from amalgam corrosion is induced by demineralization

    NARCIS (Netherlands)

    Scholtanus, Johannes D.; van der Hoorn, Wietske; Huysmans, Marie-Charlotte D. N. J. M.; Roeters, Joost F. M.; Kleverlaan, Cornelis J.; Feilzer, Albert J.; Ozcan, Mutlu

    Purpose: To evaluate the effect of artificial demineralization upon color change of dentin in contact with dental amalgam. Methods: Sound human molars (n= 34) were embedded in resin and coronal enamel was removed. Dentin was exposed to artificial caries gel (pH 5.5) at 37 degrees C for 12 weeks (n=

  20. Effects of particle size and porosity on in vivo remodeling of settable allograft bone/polymer composites.

    Science.gov (United States)

    Prieto, Edna M; Talley, Anne D; Gould, Nicholas R; Zienkiewicz, Katarzyna J; Drapeau, Susan J; Kalpakci, Kerem N; Guelcher, Scott A

    2015-11-01

    Established clinical approaches to treat bone voids include the implantation of autograft or allograft bone, ceramics, and other bone void fillers (BVFs). Composites prepared from lysine-derived polyurethanes and allograft bone can be injected as a reactive liquid and set to yield BVFs with mechanical strength comparable to trabecular bone. In this study, we investigated the effects of porosity, allograft particle size, and matrix mineralization on remodeling of injectable and settable allograft/polymer composites in a rabbit femoral condyle plug defect model. Both low viscosity and high viscosity grafts incorporating small (<105 μm) particles only partially healed at 12 weeks, and the addition of 10% demineralized bone matrix did not enhance healing. In contrast, composite grafts with large (105-500 μm) allograft particles healed at 12 weeks postimplantation, as evidenced by radial μCT and histomorphometric analysis. This study highlights particle size and surface connectivity as influential parameters regulating the remodeling of composite bone scaffolds. © 2015 Wiley Periodicals, Inc.

  1. Extracellular matrix production by nucleus pulposus and bone marrow stem cells in response to altered oxygen and glucose microenvironments.

    Science.gov (United States)

    Naqvi, Syeda M; Buckley, Conor T

    2015-12-01

    Bone marrow (BM) stem cells may be an ideal source of cells for intervertebral disc (IVD) regeneration. However, the harsh biochemical microenvironment of the IVD may significantly influence the biological and metabolic vitality of injected stem cells and impair their repair potential. This study investigated the viability and production of key matrix proteins by nucleus pulposus (NP) and BM stem cells cultured in the typical biochemical microenvironment of the IVD consisting of altered oxygen and glucose concentrations. Culture-expanded NP cells and BM stem cells were encapsulated in 1.5% alginate and ionically crosslinked to form cylindrical hydrogel constructs. Hydrogel constructs were maintained under different glucose concentrations (1, 5 and 25 mM) and external oxygen concentrations (5 and 20%). Cell viability was measured using the Live/Dead® assay and the production of sulphated glycosaminoglycans (sGAG), and collagen was quantified biochemically and histologically. For BM stem cells, IVD-like micro-environmental conditions (5 mM glucose and 5% oxygen) increased the accumulation of sGAG and collagen. In contrast, low glucose conditions (1 mM glucose) combined with 5% external oxygen concentration promoted cell death, inhibiting proliferation and the accumulation of sGAG and collagen. NP-encapsulated alginate constructs were relatively insensitive to oxygen concentration or glucose condition in that they accumulated similar amounts of sGAG under all conditions. Under IVD-like microenvironmental conditions, NP cells were found to have a lower glucose consumption rate compared with BM cells and may in fact be more suitable to adapt and sustain the harsh microenvironmental conditions. Considering the highly specialised microenvironment of the central NP, these results indicate that IVD-like concentrations of low glucose and low oxygen are critical and influential for the survival and biological behaviour of stem cells. Such findings may promote and accelerate

  2. Photothermal tomography for the functional and structural evaluation, and early mineral loss monitoring in bones.

    Science.gov (United States)

    Kaiplavil, Sreekumar; Mandelis, Andreas; Wang, Xueding; Feng, Ting

    2014-08-01

    Salient features of a new non-ionizing bone diagnostics technique, truncated-correlation photothermal coherence tomography (TC-PCT), exhibiting optical-grade contrast and capable of resolving the trabecular network in three dimensions through the cortical region with and without a soft-tissue overlayer are presented. The absolute nature and early demineralization-detection capability of a marker called thermal wave occupation index, estimated using the proposed modality, have been established. Selective imaging of regions of a specific mineral density range has been demonstrated in a mouse femur. The method is maximum-permissible-exposure compatible. In a matrix of bone and soft-tissue a depth range of ~3.8 mm has been achieved, which can be increased through instrumental and modulation waveform optimization. Furthermore, photoacoustic microscopy, a comparable modality with TC-PCT, has been used to resolve the trabecular structure and for comparison with the photothermal tomography.

  3. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling...... of aged bones....

  4. Development of Bone Remodeling Model for Spaceflight Bone Physiology Analysis

    Science.gov (United States)

    Pennline, James A.; Werner, Christopher R.; Lewandowski, Beth; Thompson, Bill; Sibonga, Jean; Mulugeta, Lealem

    2015-01-01

    Current spaceflight exercise countermeasures do not eliminate bone loss. Astronauts lose bone mass at a rate of 1-2% a month (Lang et al. 2004, Buckey 2006, LeBlanc et al. 2007). This may lead to early onset osteoporosis and place the astronauts at greater risk of fracture later in their lives. NASA seeks to improve understanding of the mechanisms of bone remodeling and demineralization in 1g in order to appropriately quantify long term risks to astronauts and improve countermeasures. NASA's Digital Astronaut Project (DAP) is working with NASA's bone discipline to develop a validated computational model to augment research efforts aimed at achieving this goal.

  5. DEMINERALIZATION OF HUMAN DENTIN COMPARED WITH ENAMEL IN A PH-CYCLING APPARATUS WITH A CONSTANT COMPOSITION DURING DE-MINERALIZATION AND REMINERALIZATION PERIODS

    NARCIS (Netherlands)

    HERKSTROTER, FM; WITJES, M; ARENDS, J

    1991-01-01

    A comparison was made between the demineralization of enamel and dentine with and without abraded surfaces. This was done in a pH-cycling experiment for different demineralization/remineralization ratios - in the range from 1:1 to 1:4 - and for different fluoride additions (up to 2 ppm) in solution.

  6. Alternatives to Autologous Bone Graft in Alveolar Cleft Reconstruction: The State of Alveolar Tissue Engineering.

    Science.gov (United States)

    Liang, Fan; Leland, Hyuma; Jedrzejewski, Breanna; Auslander, Allyn; Maniskas, Seija; Swanson, Jordan; Urata, Mark; Hammoudeh, Jeffrey; Magee, William

    2018-05-01

    Alveolar cleft reconstruction has historically relied on autologous iliac crest bone grafting (ICBG), but donor site morbidity, pain, and prolonged hospitalization have prompted the search for bone graft substitutes. The authors evaluated bone graft substitutes with the highest levels of evidence, and highlight the products that show promise in alveolar cleft repair and in maxillary augmentation. This comprehensive review guides the craniofacial surgeon toward safe and informed utilization of biomaterials in the alveolar cleft.A literature search was performed to identify in vitro human studies that fulfilled the following criteria: Level I or Level II of evidence, ≥30 subjects, and a direct comparison between a autologous bone graft and a bone graft substitute. A second literature search was performed that captured all studies, regardless of level of evidence, which evaluated bone graft substitutes for alveolar cleft repair or alveolar augmentation for dental implants. Adverse events for each of these products were tabulated as well.Sixteen studies featuring 6 bone graft substitutes: hydroxyapatite, demineralized bone matrix (DBM), β-tricalcium phosphate (TCP), calcium phosphate, recombinant human bone morphogenic protein-2 (rhBMP-2), and rhBMP7 fit the inclusion criteria for the first search. Through our second search, the authors found that DBM, TCP, rhBMP-2, and rhBMP7 have been studied most extensively in the alveolar cleft literature, though frequently in studies using less rigorous methodology (Level III evidence or below). rhBMP-2 was the best studied and showed comparable efficacy to ICBG in terms of volume of bone regeneration, bone density, and capacity to accommodate tooth eruption within the graft site. Pricing for products ranged from $290 to $3110 per 5 mL.The balance between innovation and safety is a complex process requiring constant vigilance and evaluation. Here, the authors profile several bone graft substitutes that demonstrate the most

  7. Unicameral bone cyst of the humeral head: arthroscopic curettage and bone grafting.

    Science.gov (United States)

    Randelli, Pietro; Arrigoni, Paolo; Cabitza, Paolo; Denti, Matteo

    2009-01-01

    Arthroscopic surgery has improved greatly over the past decade. Treatment of various juxta-articular disorders around the shoulder have benefited from endoscopic approaches. Cystic lesions of the shoulder on the scapular side have been treated in this way. This article describes a case of a 29-year-old patient with a unicameral bone cyst on the posterior aspect of the humeral head. Arthroscopic visualization using an accessory posteroinferior portal localized the cyst through the bare area of the humeral head. A cannulated burr was used to create an opening through the cortical wall between the cyst and the joint, and a careful curettage was performed. The cavity was filled with a demineralized bone matrix enriched with autologous blood packed into an arthroscopic cannula and delivered through the accessory portal. The patient reported pain relief immediately postoperatively and at follow-up. This case demonstrates the feasibility of arthroscopic treatment of a simple bone cyst of the humeral head. We believe that the knowledge of the juxta-articular anatomy allows the applications of scope-assisted procedures to be expanded, maximizing the results of a technique that allows a shorter recovery and less painful rehabilitation.

  8. Solubility effects in waste-glass/demineralized-water systems

    International Nuclear Information System (INIS)

    Fullam, H.T.

    1981-06-01

    Aqueous systems involving demineralized water and four glass compositions (including standins for actinides and fission products) at temperatures of up to 150 0 C were studied. Two methods were used to measure the solubility of glass components in demineralized water. One method involved approaching equilibrium from subsaturation, while the second method involved approaching equilibrium from supersaturation. The aqueous solutions were analyzed by induction-coupled plasma spectrometry (ICP). Uranium was determined using a Scintrex U-A3 uranium analyzer and zinc and cesium were determined by atomic absorption. The system that results when a waste glass is contacted with demineralized water is a complex one. The two methods used to determine the solubility limits gave very different results, with the supersaturation method yielding much higher solution concentrations than the subsaturation method for most of the elements present in the waste glasses. The results show that it is impossible to assign solubility limits to the various glass components without thoroughly describing the glass-water systems. This includes not only defining the glass type and solution temperature, but also the glass surface area-to-water volume ratio (S/V) of the system and the complete thermal history of the system. 21 figures, 22 tables

  9. Forensic DNA typing from teeth using demineralized root tips.

    Science.gov (United States)

    Corrêa, Heitor Simões Dutra; Pedro, Fabio Luis Miranda; Volpato, Luiz Evaristo Ricci; Pereira, Thiago Machado; Siebert Filho, Gilberto; Borges, Álvaro Henrique

    2017-11-01

    Teeth are widely used samples in forensic human genetic identification due to their persistence and practical sampling and processing. Their processing, however, has changed very little in the last 20 years, usually including powdering or pulverization of the tooth. The objective of this study was to present demineralized root tips as DNA sources while, at the same time, not involving powdering the samples or expensive equipment for teeth processing. One to five teeth from each of 20 unidentified human bodies recovered from midwest Brazil were analyzed. Whole teeth were demineralized in EDTA solution with daily solution change. After a maximum of approximately seven days, the final millimeters of the root tip was excised. This portion of the sample was used for DNA extraction through a conventional organic protocol. DNA quantification and STR amplification were performed using commercial kits followed by capillary electrophoresis on 3130 or 3500 genetic analyzers. For 60% of the unidentified bodies (12 of 20), a full genetic profile was obtained from the extraction of the first root tip. By the end of the analyses, full genetic profiles were obtained for 85% of the individuals studied, of which 80% were positively identified. This alternative low-tech approach for postmortem teeth processing is capable of extracting DNA in sufficient quantity and quality for forensic casework, showing that root tips are viable nuclear DNA sources even after demineralization. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Histological and histomorphometrical analysis of a silica matrix embedded nanocrystalline hydroxyapatite bone substitute using the subcutaneous implantation model in Wistar rats

    Energy Technology Data Exchange (ETDEWEB)

    Ghanaati, Shahram; Orth, Carina; Barbeck, Mike; Kirkpatrick, Charles James [Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55101 Mainz (Germany); Willershausen, Ines [Institute for Dental Material Sciences and Technology, University Medical Center of the Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 14, 55128 Mainz (Germany); Thimm, Benjamin W [Institute for Biomechanics, ETH Zuerich, Wolfgang-Pauli-Str.10, 8093 Zuerich (Switzerland); Booms, Patrick [Leeds Institute of Molecular Medicine, Section of Medicine, Surgery and Anaesthesia, University of Leeds (United Kingdom); Stuebinger, Stefan; Landes, Constantin; Sader, Robert Anton, E-mail: ghanaati@uni-mainz.d [Department for Oral, Cranio-Maxillofacial and Facial Plastic Surgery, Medical Center of the Goethe University Frankfurt, Theodor-Stein-Kai 7, 60596 Frankfurt am Main (Germany)

    2010-06-01

    The clinical suitability of a bone substitute material is determined by the ability to induce a tissue reaction specific to its composition. The aim of this in vivo study was to analyze the tissue reaction to a silica matrix-embedded, nanocrystalline hydroxyapatite bone substitute. The subcutaneous implantation model in Wistar rats was chosen to assess the effect of silica degradation on the vascularization of the biomaterial and its biodegradation within a time period of 6 months. Already at day 10 after implantation, histomorphometrical analysis showed that the vascularization of the implantation bed reached its peak value compared to all other time points. Both vessel density and vascularization significantly decreased until day 90 after implantation. In this time period, the bone substitute underwent a significant degradation initiated by TRAP-positive and TRAP-negative multinucleated giant cells together with macrophages and lymphocytes. Although no specific tissue reaction could be related to the described silica degradation, the biomaterial was close to being fully degraded without a severe inflammatory response. These characteristics are advantageous for bone regeneration and remodeling processes.

  11. Three-dimensional bone tissue substitute based on a human mesenchymal stem cell culture on a nanofiber carrier and inorganic matrix

    Directory of Open Access Journals (Sweden)

    Martin Krbec

    2016-01-01

    Full Text Available The aim was to construct a composite structure for bone tissue substitute on the basis of a degradable composite of an organic nanofiber carrier and an inorganic matrix in 3D, and to achieve subsequent colonisation by differentiated human mesenchymal stem cells (hMSC towards osteocytes. We developed an active bone tissue substitute using nanofiber technology for a polycaprolactone (PCL scaffold with the addition of hydroxyapatite and the colonisation of both components with hMSC with the ability of differentiation towards osteocytes. The constructed composition included the components necessary for bone healing (inorganic and cellular and it also forms a spatially-oriented 3D structure. We used polycaprolactone Mw 70,000 with electrostatic spinning for the formation of nanofibers using a modified NanospiderTM method. For the inorganic component we used orthophosphate-calcium silicate with a crystal size of 1-2 mm which the nanofiber membrane was coated with. Both components were connected together with a tissue adhesive based of fibrin glue. Cultivated hMSC cells at a concentration of 1.2 × 104/cm2 were multiplied in vitro and then cultivated in the expansion medium. HMSC overgrew both the PCL membrane and the Si-CaP crystals. After colonisation with cultivated cells, this composite 3D structure can serve as a three-dimensional bone tissue replacement.

  12. Histological and histomorphometrical analysis of a silica matrix embedded nanocrystalline hydroxyapatite bone substitute using the subcutaneous implantation model in Wistar rats

    International Nuclear Information System (INIS)

    Ghanaati, Shahram; Orth, Carina; Barbeck, Mike; Kirkpatrick, Charles James; Willershausen, Ines; Thimm, Benjamin W; Booms, Patrick; Stuebinger, Stefan; Landes, Constantin; Sader, Robert Anton

    2010-01-01

    The clinical suitability of a bone substitute material is determined by the ability to induce a tissue reaction specific to its composition. The aim of this in vivo study was to analyze the tissue reaction to a silica matrix-embedded, nanocrystalline hydroxyapatite bone substitute. The subcutaneous implantation model in Wistar rats was chosen to assess the effect of silica degradation on the vascularization of the biomaterial and its biodegradation within a time period of 6 months. Already at day 10 after implantation, histomorphometrical analysis showed that the vascularization of the implantation bed reached its peak value compared to all other time points. Both vessel density and vascularization significantly decreased until day 90 after implantation. In this time period, the bone substitute underwent a significant degradation initiated by TRAP-positive and TRAP-negative multinucleated giant cells together with macrophages and lymphocytes. Although no specific tissue reaction could be related to the described silica degradation, the biomaterial was close to being fully degraded without a severe inflammatory response. These characteristics are advantageous for bone regeneration and remodeling processes.

  13. Enhanced Androgen Signaling With Androgen Receptor Overexpression in the Osteoblast Lineage Controls Skeletal Turnover, Matrix Quality and Bone Architecture

    National Research Council Canada - National Science Library

    Wiren, Kristine M; Jepsen, Karl

    2006-01-01

    .... We genetically engineered transgenic mice in which androgen receptor (AR) overexpression is skeletally targeted in two separate models to better understand the role of androgen signaling directly in bone...

  14. Demineralization of Enamel in Primary Second Molars Related to Properties of the Enamel

    Directory of Open Access Journals (Sweden)

    N. Sabel

    2012-01-01

    Full Text Available Enamel structure is of importance in demineralization. Differences in porosity in enamel effect the rate of demineralization, seen between permanent and deciduous teeth. Individual differences have been shown in the mean mineral concentration values in enamel, the role of this in demineralization is not thoroughly investigated. The aim of this study was to study variations of depths of artificial lesions of demineralization and to analyze the depth in relation to variations in the chemical and mineral composition of the enamel. A demineralized lesion was created in second primary molars from 18 individuals. Depths of lesions were then related to individual chemical content of the enamel. Enamel responded to demineralization with different lesion depths and this was correlated to the chemical composition. The carbon content in sound enamel was shown to be higher where lesions developed deeper. The lesion was deeper when the degree of porosity of the enamel was higher.

  15. Removal of different fractions of NOM foulants during demineralized water backwashing

    KAUST Repository

    Li, Sheng

    2012-09-01

    The effectiveness of demineralized water backwashing on fouling by different fractions of NOM was investigated in this study. Two types of natural surface water (Schie canal and Biesbosch reservoir) were tested to confirm the improvement of demineralized water backwashing on fouling control, and LC-OCD analysis was conducted on Schie canal water to find out which fraction of NOM was removed with those backwashes. Results derived from natural waters showed that demineralized water backwashing substantially improved UF fouling control. LC-OCD analyses showed both UF permeate and demineralized water backwashes were effective on removing part of biopolymers, but demineralized water is also effective for humic substances and a limited amount of low molecular weight substances. However, based on the LC-OCD results, even demineralized water backwashing is not effective to remove all humic substances and biopolymers rejected on the UF membranes. © 2012 Elsevier B.V. All rights reserved.

  16. In vitro demineralization of tooth enamel subjected to two whitening regimens.

    Science.gov (United States)

    Ogura, Kayoko; Tanaka, Reina; Shibata, Yo; Miyazaki, Takashi; Hisamitsu, Hisashi

    2013-07-01

    The resistance of bleached enamel to demineralization has not been elucidated fully. In this study, the authors aimed to examine the level of in vitro demineralization of human tooth enamel after bleaching by using two common bleaching regimens: home bleaching (HB) and office bleaching (OB) with photoirradiation. The authors bleached teeth to equivalent levels by means of the two bleaching regimens. They used fluorescence spectroscopy to measure the reduction in enamel density and the release of calcium into solution after storing the treated teeth in a demineralizing solution for two weeks. They also visualized and quantified mineral distribution in demineralized bleached enamel over time by using a desktop microcomputed-tomographic analyzer. Enamel subjected to HB or to photoirradiation without bleaching showed increased demineralization. In contrast, enamel treated with OB was more resistant to demineralization. This resistance to demineralization in teeth treated with OB presumably is due to peroxide's permeating to deeper layers of enamel before being activated by photoirradiation, which enhances mineralization. The mineral distribution pattern of enamel after treatment plays a critical role in providing resistance to demineralization in whitened teeth. OB confers to enamel significant resistance to in vitro demineralization. Dentists should supervise the nightguard HB process.

  17. Regenerative surgical therapy for peri-implantitis using deproteinized bovine bone mineral with 10% collagen, enamel matrix derivative and Doxycycline-A prospective 3-year cohort study.

    Science.gov (United States)

    Mercado, Faustino; Hamlet, Stephen; Ivanovski, Saso

    2018-05-16

    There is limited evidence regarding the long-term efficacy of regenerative treatment for peri-implantitis. The aim of this study was to evaluate a combination therapy of deproteinized bovine bone mineral with 10% collagen (DBBMC), enamel matrix derivative (EMD) and Doxycycline in the regeneration of bone defects associated with peri-implantitis. Thirty patients diagnosed with peri-implantitis (BoP/suppuration, probing depth greater than 4 mm, minimum radiographic bone loss of 20%, at least 2 years in function) were enrolled in the study. Clinical measurements included probing depths, recession, radiographic bone fill, gingival inflammation and bleeding on probing/suppuration. Following surgical access and debridement, the implant surfaces were decontaminated with 24% EDTA for 2 min, and the bone defects were filled with a combined mixture of DBBMC, EMD and Doxycycline powder. The defects were covered with connective tissue grafts where necessary. Clinical measurements were recorded after 12, 24 and 36 months. The mean probing depth and bone loss at the initial visit was 8.9 mm (±1.9) and 6.92 mm (±1.26), respectively. Both mean probing depth and bone loss reduced significantly from baseline to 3.55 mm (±0.50) and 2.85 mm (±0.73) at 12 months, 3.50 (±0.50) and 2.62 mm (±0.80) at 24 months and 3.50 mm (±0.50) and 2.60 mm (±0.73) at 36 months. 56.6% of the implants were considered successfully treated (according to Successful Treatment Outcome Criterion: PD 10%, no BoP/suppuration, no recession >0.5 mm for anterior implants and >1.5 mm for posterior implants) after 36 months. Regenerative treatment of peri-implantitis using a combined mixture of DBBMC, EMD and Doxycycline achieved promising results. The benefits of this protocol incorporating EMD should be tested in randomized clinical trials. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Efficacy of various topical agents to prevent enamel demineralization

    Directory of Open Access Journals (Sweden)

    Priska Lestari Hendrawan

    2011-09-01

    Full Text Available Background: Enamel demineralization is a common and undesirable side effect of fixed appliance orthodontic treatment. Many sudies showed that the prevalence varied between 2–96%. There are many ways to prevent demineralization and increased remineralization such as oral hygiene instruction and by topical application such as acidulated phosphate fluor (APF casein phospo peptide-amorphous calcium phosphate (CPP-ACP, casein phospo peptide-amorphous calcium phosphate plus (CPP-ACPF. Purpose: The purpose of this in-vitro study was to evaluate the efficacy of various topical agents to prevent enamel demineralization. Methods: Fourty extracted human premolars were allocated to 1 of 4 groups: 1.23% APF gel; 10% CPP-ACP paste; 10% CPP-ACPF paste; and untreated control. All samples were subjected to pH cycling treatment for 12 days through a daily procedure of demineralization solution with pH 4 for 6 hours and remineralization solution with pH 7 for 18 hours. Microhardness testing were done before and after pH cycling and the delta hardness values were determined. Results: APF, CPP-ACP and CPP-ACPF application significantly prevent lowering of enamel microhardness value compared with untreated control group. Kruskal-Wallis, ANOVA, Mann-Whitney U, Tukey and Bonferroni Post-Hoc multiple comparison test showed significant difference between mean delta microhardness value of CPP-ACPF and CPP-ACP group with APF group, but there is no significant difference between mean delta microhardness value of CPP-ACPF and CPP-ACP group. Conclusion: APF, CPP-ACP and CPP-ACPF prevent enamel demineralization. CPP-ACP and CPP-ACPF prevent demineralization more than APF.Latar belakang: Demineralisasi email merupakan efek samping negatif yang sering dijumpai pada perawatan ortodontik cekat. Beberapa penelitian menyatakan bahwa prevalensinya bervariasi 2–96 persen. Ada beberapa cara untuk mencegah demineralisasi dan meningkatkan remineralisasi, misalnya dengan instruksi

  19. Immobilization and long-term recovery results in large changes in bone structure and strength but no corresponding alterations of osteocyte lacunar properties.

    Science.gov (United States)

    Bach-Gansmo, Fiona Linnea; Wittig, Nina Kølln; Brüel, Annemarie; Thomsen, Jesper Skovhus; Birkedal, Henrik

    2016-10-01

    The ability of osteocytes to demineralize the perilacunar matrix, osteocytic osteolysis, and thereby participate directly in bone metabolism, is an aspect of osteocyte biology that has received increasing attention during the last couple of years. The aim of the present work was to investigate whether osteocyte lacunar properties change during immobilization and subsequent recovery. A rat cortical bone model with negligible Haversian remodeling effects was used, with temporary immobilization of one hindlimb induced by botulinum toxin. Several complementary techniques covering multiple length scales enabled correlation of osteocyte lacunar properties to changes observed on the organ and tissue level of femoral bone. Bone structural parameters measured by μCT and mechanical properties were compared to sub-micrometer resolution SR μCT data mapping an unprecedented number (1.85 million) of osteocyte lacunae. Immobilization induced a significant reduction in aBMD, bone volume, tissue volume, and load to fracture, as well as the muscle mass of rectus femoris. During the subsequent recovery period, the bone structural and mechanical properties were only partly regained in spite of a long-term (28weeks) study period. No significant changes in osteocyte lacunar volume, density, oblateness, stretch, or orientation were detected upon immobilization or subsequent recovery. In conclusion, the bone architecture and not osteocyte lacunar properties or bone material characteristics dominate the immobilization response as well as the subsequent recovery. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Biofilm extracellular polysaccharides degradation during starvation and enamel demineralization.

    Directory of Open Access Journals (Sweden)

    Bárbara Emanoele Costa Oliveira

    Full Text Available This study was conducted to evaluate if extracellular polysaccharides (EPS are used by Streptococcus mutans (Sm biofilm during night starvation, contributing to enamel demineralization increasing occurred during daily sugar exposure. Sm biofilms were formed during 5 days on bovine enamel slabs of known surface hardness (SH. The biofilms were exposed to sucrose 10% or glucose + fructose 10.5% (carbohydrates that differ on EPS formation, 8x/day but were maintained in starvation during the night. Biofilm samples were harvested during two moments, on the end of the 4th day and in the morning of the 5th day, conditions of sugar abundance and starvation, respectively. The slabs were also collected to evaluate the percentage of surface hardness loss (%SHL. The biofilms were analyzed for EPS soluble and insoluble and intracellular polysaccharides (IPS, viable bacteria (CFU, biofilm architecture and biomass. pH, calcium and acid concentration were determined in the culture medium. The data were analyzed by two-way ANOVA followed by Tukey's test or Student's t-test. The effect of the factor carbohydrate treatment for polysaccharide analysis was significant (p 0.05. Larger amounts of soluble and insoluble EPS and IPS were formed in the sucrose group when compared to glucose + fructose group (p < 0.05, but they were not metabolized during starvation time (S-EPS, p = 0.93; I-EPS, p = 0.11; and IPS = 0.96. Greater enamel %SHL was also found for the sucrose group (p < 0.05 but the demineralization did not increase during starvation (p = 0.09. In conclusion, the findings suggest that EPS metabolization by S. mutans during night starvation do not contribute to increase enamel demineralization occurred during the daily abundance of sugar.

  1. Release of organics from BWR condensate demineralizer resins

    International Nuclear Information System (INIS)

    Ohira, Taku; Furukawa, Makoto; Sekiguchi, Masahiko; Takiguchi, Hideki; Deguchi, Tatsuya; Ino, Takao; Izumi, Takeshi; Hagiwara, Masahiro

    1998-01-01

    In BWRs, one of major factors to affect water chemistry in reactor is the organics leaching from condensate demineralizer. Especially, the organics from cation ion exchange resin (described CER hereafter) is intaken to reactor and changes to the sulfuric acid due to thermal decomposition and radiolysis, because CER contains sulfuric groups. In this paper, the influence of environmental parameters and structure of ion exchange resin (described IER hereafter) on the organics leaching are clarified by using 'the new method' developed for accurate measurement organics leaching from IER. Based on these results, the mechanism of the organics leaching from IER is discussed. (author)

  2. Comparison of 3D-Printed Poly-ɛ-Caprolactone Scaffolds Functionalized with Tricalcium Phosphate, Hydroxyapatite, Bio-Oss, or Decellularized Bone Matrix.

    Science.gov (United States)

    Nyberg, Ethan; Rindone, Alexandra; Dorafshar, Amir; Grayson, Warren L

    2017-06-01

    Three-dimensional (3D)-printing facilitates rapid, custom manufacturing of bone scaffolds with a wide range of material choices. Recent studies have demonstrated the potential for 3D-printing bioactive (i.e., osteo-inductive) scaffolds for use in bone regeneration applications. In this study, we 3D-printed porous poly-ɛ-caprolactone (PCL) scaffolds using a fused deposition modeling (FDM) process and functionalized them with mineral additives that have been widely used commercially and clinically: tricalcium phosphate (TCP), hydroxyapatite (HA), Bio-Oss (BO), or decellularized bone matrix (DCB). We assessed the "print quality" of the composite scaffolds and found that the print quality of PCL-TCP, PCL-BO, and PCL-DCB measured ∼0.7 and was statistically lower than PCL and PCL-HA scaffolds (∼0.8). We found that the incorporation of mineral particles did not significantly decrease the compressive modulus of the graft, which was on the order of 260 MPa for solid blocks and ranged from 32 to 83 MPa for porous scaffolds. Raman spectroscopy revealed the surfaces of the scaffolds maintained the chemical profile of their dopants following the printing process. We evaluated the osteo-inductive properties of each scaffold composite by culturing adipose-derived stromal/stem cells in vitro and assessing their differentiation into osteoblasts. The calcium content (normalized to DNA) increased significantly in PCL-TCP (p  0.05). Collagen 1 expression was 10-fold greater than PCL in PCL-BO and PCL-DCB (p < 0.05) and osteocalcin expression was 10-fold greater in PCL-BO and PCL-DCB (p < 0.05) as measured by quantitative-real time-polymerase chain reaction. This study suggests that PCL-BO and PCL-DCB hybrid material may be advantageous for bone healing applications over PCL-HA or PCL-TCP blends.

  3. A fiber-optic setup for quantification of root surface demineralization

    NARCIS (Netherlands)

    vanderVeen, MH; tenBosch, JJ

    A fiber-optic fluorescence observation (FOFO) technique has been developed for the quantification of demineralized root dentin, The method was tested on 40 specimens of in vitro demineralized parts of human root dentin, Fluorescein sodium salt was used as a penetrating dye, The fluorescein sodium

  4. Reverse osmosis using for water demineralization for supplying the NPP and TPP steam generators

    International Nuclear Information System (INIS)

    Mamet, A.P.; Sitnyakovskij, Yu.A.

    2000-01-01

    Paper analyzes the conditions affecting the efficiency of water reverse-osmosis demineralization for NPP and TPP steam generators and presents an example of efficient application of a membrane reverse-osmosis facility serving as the first stage of water demineralization at the Mosehnergo Joint-Stock Company heating and power plant no. 23 to feed boilers [ru

  5. The influence of an in vitro generated bone-like extracellular matrix on osteoblastic gene expression of marrow stromal cells.

    NARCIS (Netherlands)

    Pham, Q.P.; Kasper, F.K.; Baggett, L.S.; Raphael, R.M.; Jansen, J.A.; Mikos, A.G.

    2008-01-01

    The function and development of cells rely heavily on the signaling interactions with the surrounding extracellular matrix (ECM). Therefore, a tissue engineering scaffold should mimic native ECM to recreate the in vivo environment. Previously, we have shown that an in vitro generated ECM secreted by

  6. Repair of Traumatic Skeletal Muscle Injury with Bone-Marrow-Derived Mesenchymal Stem Cells Seeded on Extracellular Matrix

    Science.gov (United States)

    2010-06-02

    expressing full length dystrophin can complement Duchenne muscular dystrophy myotubes by cell fusion. Hum Mol Genet 15, 213, 2006. 52. Pittenger, M.F., et al... muscle , and vascular tissue, that are necessary for viable muscular regeneration after muscle defect injury.29–32 Cells from the bone marrow are known to...3,3-diaminobenzidine. Muscular infiltration into the ECM was further confirmed by immunofluorescent staining for the muscle -specific cyto- skeleton

  7. Lactic acid demineralization of shrimp shell and chitosan synthesis

    Directory of Open Access Journals (Sweden)

    Alewo Opuada AMEH

    2015-05-01

    Full Text Available The use of lactic acid was compared to hydrochloric acid for shrimp shell demineralization in chitosan synthesis. Five different acid concentrations were considered for the study: 1.5M, 3.0M, 4.5M, 6.0M and 7.5M. After demineralization, the shrimp shell were deproteinized and subsequently deacetylated to produce chitosan using sodium hydroxide solution. The synthesized chitosan samples were characterized using solubility, FTIR, SEM, XRD and viscosity. The SEM, FTIR and XRD analysis indicated that chitosan was synthesized with a high degree of deacetylation (83.18±2.11 when lactic acid was used and 84.2±5.00 when HCl was used. The degree of deacetylation and the molecular weight of the chitosan samples were also estimated. ANOVA analysis (at 95% confidence interval indicated that acid type and concentration did not significantly affect the solubility, degree of deacetylation, viscosity and molecular weight of the chitosan within the range considered.

  8. Grafton and local bone have comparable outcomes to iliac crest bone in instrumented single-level lumbar fusions.

    Science.gov (United States)

    Kang, James; An, Howard; Hilibrand, Alan; Yoon, S Tim; Kavanagh, Eoin; Boden, Scott

    2012-05-20

    Prospective multicenter randomized clinical trail. The goal of our 2-year prospective study was to perform a randomized clinical trial comparing the outcomes of Grafton demineralized bone matrix (DBM) Matrix with local bone with that of iliac crest bone graft (ICBG) in a single-level instrumented posterior lumbar fusion. There has been extensive research and development in identifying a suitable substitute to replace autologous ICBG that is associated with known morbidities. DBMs are a class of commercially available grafting agents that are prepared from allograft bone. Many such products have been commercially available for clinical use; however, their efficacy for spine fusion has been mostly based on anecdotal evidence rather than randomized controlled clinical trials. Forty-six patients were randomly assigned (2:1) to receive Grafton DBM Matrix with local bone (30 patients) or autologous ICBG (16 patients). The mean age was 64 (females [F] = 21, males [M] = 9) in the DBM group and 65 (F = 9, M = 5) in the ICBG group. An independent radiologist evaluated plain radiographs and computed tomographic scans at 6-month, 1-year, and 2-year time points. Clinical outcomes were measured using Oswestry Disability Index (ODI) and Medical Outcomes Study 36-Item Short Form Health Survey. Forty-one patients (DBM = 28 and ICBG = 13) completed the 2-year follow-up. Final fusion rates were 86% (Grafton Matrix) versus 92% (ICBG) (P = 1.0 not significant). The Grafton group showed slightly better improvement in ODI score than the ICBG group at the final 2-year follow-up (Grafton [16.2] and ICBG [22.7]); however, the difference was not statistically significant (P = 0.2346 at 24 mo). Grafton showed consistently higher physical function scores at 24 months; however, differences were not statistically significant (P = 0.0823). Similar improvements in the physical component summary scores were seen in both the Grafton and ICBG groups. There was a statistically significant greater mean

  9. Synthesis and characterization of injectable, thermosensitive, and biocompatible acellular bone matrix/poly(ethylene glycol)-poly (ε-caprolactone)-poly(ethylene glycol) hydrogel composite.

    Science.gov (United States)

    Ni, Pei-Yan; Fan, Min; Qian, Zhi-Yong; Luo, Jing-Cong; Gong, Chang-Yang; Fu, Shao-Zhi; Shi, Shuai; Luo, Feng; Yang, Zhi-Ming

    2012-01-01

    In orthopedic tissue engineering, the extensively applied acellular bone matrix (ABM) can seldom be prefabricated just right to mold the cavity of the diverse defects, might induce severe inflammation on account of the migration of small granules and usually bring the patients great pain in the treatment. In this study, a new injectable thermosensitive ABM/PECE composite with good biocompatibility was designed and prepared by adding the ABM granules into the triblock copolymer poly(ethylene eglycol)-poly(ε-caprolactone)-poly(ethylene eglycol) (PEG-PCL-PEG, PECE). The PECE was synthesized by ring-opening copolymerization and characterized by ¹H NMR. The ABM was prepared by acellular treatment of natural bone and ground to fine granules. The obtained ABM/PECE composite showed the most important absorption bands of ABM and PECE copolymer in FT-IR spectroscopy and underwent sol-gel phage transition from solution to nonflowing hydrogel at 37°C. SEM results indicated that the ABM/PECE composite with different ABM contents all presented similar porous 3D structure. ABM/PECE composite presented mild cytotoxicity to rat MSCs in vitro and good biocompatibility in the BALB/c mice subcutis up to 4 weeks. In conclusion, all the results confirmed that the injectable thermosensitive ABM/PECE composite was a promising candidate for orthopedic tissue engineering in a minimally-invasive way. Copyright © 2011 Wiley Periodicals, Inc.

  10. Mechanobiology of bone marrow stem cells: from myosin-II forces to compliance of matrix and nucleus in cell forms and fates.

    Science.gov (United States)

    Shin, Jae-Won; Swift, Joe; Ivanovska, Irena; Spinler, Kyle R; Buxboim, Amnon; Discher, Dennis E

    2013-10-01

    Adult stem cells and progenitors are of great interest for their clinical application as well as their potential to reveal deep sensitivities to microenvironmental factors. The bone marrow is a niche for at least two types of stem cells, and the prototype is the hematopoietic stem cell/progenitors (HSC/Ps), which have saved many thousands of patients for several decades now. In bone marrow, HSC/Ps interact functionally with marrow stromal cells that are often referred to as mesenchymal stem cells (MSCs) or derivatives thereof. Myosin and matrix elasticity greatly affect MSC function, and these mechanobiological factors are now being explored with HSC/Ps both in vitro and in vivo. Also emerging is a role for the nucleus as a mechanically sensitive organelle that is semi-permeable to transcription factors which are modified for nuclear entry by cytoplasmic mechanobiological pathways. Since therapies envisioned with induced pluripotent stem cells and embryonic stem cells generally involve in vitro commitment to an adult stem cell or progenitor, a very deep understanding of stem cell mechanobiology is essential to progress with these multi-potent cells. © 2013 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  11. Effect of Emdogain enamel matrix derivative and BMP-2 on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells.

    Science.gov (United States)

    Fawzy El-Sayed, Karim M; Dörfer, Christof; Ungefroren, Hendrick; Kassem, Neemat; Wiltfang, Jörg; Paris, Sebastian

    2014-07-01

    The objective of this study was to evaluate the effect of Emdogain (Enamel Matrix Derivative, EMD) and Bone Morphogenetic Protein-2 (BMP-2), either solely or in combination, on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells. Stem/progenitor cells were isolated from human alveolar bone proper, magnetically sorted using STRO-1 antibodies, characterized flowcytometrically for their surface markers' expression, and examined for colony formation and multilineage differentiation potential. Subsequently, cells were treated over three weeks with 100 μg/ml Emdogain (EMD-Group), or 100 ng/ml BMP-2 (BMP-Group), or a combination of 100 ng/ml BMP-2 and 100 μg/ml Emdogain (BMP/EMD-Group). Unstimulated stem/progenitor cells (MACS(+)-Group) and osteoblasts (OB-Group) served as controls. Osteogenic gene expression was analyzed using RTq-PCR after 1, 2 and 3 weeks (N = 3/group). Mineralized nodule formation was evaluated by Alizarin-Red staining. BMP and EMD up-regulated the osteogenic gene expression. The BMP Group showed significantly higher expression of Collagen-I, III, and V, Alkaline phosphatase and Osteonectin compared to MACS(+)- and OB-Group (p < 0.05; Two-way ANOVA/Bonferroni) with no mineralized nodule formation. Under in-vitro conditions, Emdogain and BMP-2 up-regulate the osteogenic gene expression of stem/progenitor cells. The combination of BMP-2 and Emdogain showed no additive effect and would not be recommended for a combined clinical stimulation. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  12. Characterization of partially hydrolyzed OCP crystals deposited in a gelatin matrix as a scaffold for bone tissue engineering

    Science.gov (United States)

    Ezoe, Yushi; Anada, Takahisa; Yamazaki, Hajime; Handa, Takuto; Kobayashi, Kazuhito; Takahashi, Tetsu; Suzuki, Osamu

    2015-03-01

    The present study was designed to investigate how hydrolysis of octacalcium phosphate (OCP) into hydroxyapatite is affected by the presence of gelatin (Gel) molecules and how osteoblastic cells respond to the resultant OCP hydrolyzate/Gel composites as the hydrolysis advances. OCP was prepared from a solution containing calcium and phosphate ions and Gel molecules, having a composition to produce a 40 wt% OCP as a final co-precipitate as the OCP/Gel. The precipitate was further incubated up to 40 h to advance the hydrolysis of OCP. These precipitates were processed to mold OCP/Gel sponges through lyophilization and dehydrothermal treatment. Chemical analysis, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and selected area electron diffraction revealed that the hydrolysis of OCP/Gel composite in hot water advanced in a time-dependent manner and faster than hydrolysis of OCP alone. The effect of Gel on the OCP hydrolysis was further examined in the presence of distinct concentrations of Gel molecules in hot water, showing that the Gel enhanced the hydrolysis as the concentration increased. Proliferation and differentiation of mouse bone marrow stromal ST-2 cells on the hydrolyzed OCP/Gel composites were compatible with Gel sponge alone after 21 days of culture, suggesting that these composites could be a candidate as a scaffold in bone tissue engineering.

  13. Characterization of partially hydrolyzed OCP crystals deposited in a gelatin matrix as a scaffold for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Ezoe, Yushi [Tohoku University Graduate School of Dentistry, Division of Oral and Maxillofacial Surgery (Japan); Anada, Takahisa [Tohoku University Graduate School of Dentistry, Division of Craniofacial Function Engineering (Japan); Yamazaki, Hajime [The Forsyth Institute, Department of Applied Oral Sciences, Center for Biomineralization (United States); Handa, Takuto; Kobayashi, Kazuhito; Takahashi, Tetsu [Tohoku University Graduate School of Dentistry, Division of Oral and Maxillofacial Surgery (Japan); Suzuki, Osamu, E-mail: suzuki-o@m.tohoku.ac.jp [Tohoku University Graduate School of Dentistry, Division of Craniofacial Function Engineering (Japan)

    2015-03-15

    The present study was designed to investigate how hydrolysis of octacalcium phosphate (OCP) into hydroxyapatite is affected by the presence of gelatin (Gel) molecules and how osteoblastic cells respond to the resultant OCP hydrolyzate/Gel composites as the hydrolysis advances. OCP was prepared from a solution containing calcium and phosphate ions and Gel molecules, having a composition to produce a 40 wt% OCP as a final co-precipitate as the OCP/Gel. The precipitate was further incubated up to 40 h to advance the hydrolysis of OCP. These precipitates were processed to mold OCP/Gel sponges through lyophilization and dehydrothermal treatment. Chemical analysis, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and selected area electron diffraction revealed that the hydrolysis of OCP/Gel composite in hot water advanced in a time-dependent manner and faster than hydrolysis of OCP alone. The effect of Gel on the OCP hydrolysis was further examined in the presence of distinct concentrations of Gel molecules in hot water, showing that the Gel enhanced the hydrolysis as the concentration increased. Proliferation and differentiation of mouse bone marrow stromal ST-2 cells on the hydrolyzed OCP/Gel composites were compatible with Gel sponge alone after 21 days of culture, suggesting that these composites could be a candidate as a scaffold in bone tissue engineering.

  14. The key role of proinflammatory cytokines, matrix proteins, RANKL/OPG and Wnt/β-catenin in bone healing of hip arthroplasty patients.

    Science.gov (United States)

    Cassuto, Jean; Folestad, Agnetha; Göthlin, Jan; Malchau, Henrik; Kärrholm, Johan

    2018-02-01

    We still lack understanding of why some implants fail while most remain stable after decades of use. Proinflammatory cytokines, matrix proteins and bone regulating cytokines of the RANKL/OPG (receptor activator of nuclear factor kappa B ligand/osteoprotegerin) and Wnt/β-catenin pathways are mandatory for normal bone repair but their spatial and temporal role in the healing of primary total hip arthroplasties (THA) has not been previously shown. Twenty-four osteoarthritis patients with one-sided well-fixed primary THA were prospectively monitored during 18years (18Y) with repeated blood samples, clinical variables and radiographs. Eighty-one healthy donors divided in three age- and gender-matched groups and twenty osteoarthritis patients awaiting THA and serving as control of the validity of stored plasma in THA patients, were included. Plasma was analyzed for C-reactive protein (CRP), interleukin (IL)-6, IL-8, IL-1β, tumor necrosis factor (TNF)-α, osteopontin (OPN), secreted protein acidic and rich in cysteine (SPARC/osteonectin), osteocalcin (OC), bone specific alkaline phosphatase (BALP), N-terminal propeptide of collagen type I (P1NP), RANKL, OPG, the Wnt agonistic ligands (Wnt)-1 and Wnt-3a, and the Wnt antagonists sclerostin, Dickkopf (Dkk)-1, Dkk-3, Dkk-4, secreted frizzled related protein (sFRP)-1, sFRP-3 and Wnt inhibitory factor-1 (Wif-1). Inflammatory mediators in arthroplasty patients (CRP, IL-6, OPN) increased significantly on day one after surgery vs preoperative value (PR) and healthy subjects and returned to baseline at 6W. TNF-α did not change relative preoperative level or healthy subjects. SPARC and OC increased in a biphasic fashion with the primary phase beginning shortly after surgery and lasting 3M (SPARC) and 2Y (OC) while the secondary phase peaked at 1Y (SPARC) and 13Y (OC), with both returning to basal level at 15Y. BALP peaked at 3M after surgery with a return to basal level at 2Y followed by a continuous increase from 5Y until 18Y. P

  15. The Influence of Autologous Bone Marrow Stem Cell Transplantation on Matrix Metalloproteinases in Patients Treated for Acute ST-Elevation Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Eline Bredal Furenes

    2014-01-01

    Full Text Available Background. Matrix metalloproteinase-9 (MMP-9, regulated by tissue inhibitor of metalloproteinase-9 (TIMP-1 and the extracellular matrix metalloproteinase inducer (EMMPRIN, contributes to plaque instability. Autologous stem cells from bone marrow (mBMC treatment are suggested to reduce myocardial damage; however, limited data exists on the influence of mBMC on MMPs. Aim. We investigated the influence of mBMC on circulating levels of MMP-9, TIMP-1, and EMMPRIN at different time points in patients included in the randomized Autologous Stem-Cell Transplantation in Acute Myocardial Infarction (ASTAMI trial (n=100. Gene expression analyses were additionally performed. Results. After 2-3 weeks we observed a more pronounced increase in MMP-9 levels in the mBMC group, compared to controls (P=0.030, whereas EMMPRIN levels were reduced from baseline to 2-3 weeks and 3 months in both groups (P<0.0001. Gene expression of both MMP-9 and EMMPRIN was reduced from baseline to 3 months. MMP-9 and EMMPRIN were significantly correlated to myocardial injury (CK: P=0.005 and P<0.001, resp. and infarct size (SPECT: P=0.018 and P=0.008, resp.. Conclusion. The results indicate that the regulation of metalloproteinases is important during AMI, however, limited influenced by mBMC.

  16. Influence of bone morphogenetic protein-2 on the extracellular matrix, material properties, and gene expression of long-term articular chondrocyte cultures: loss of chondrocyte stability.

    Science.gov (United States)

    Krawczak, David A; Westendorf, Jennifer J; Carlson, Cathy S; Lewis, Jack L

    2009-06-01

    The aim of this study was to determine the effects of bone morphogenetic protein-2 (BMP-2) on articular chondrocyte tissues grown as monolayers in vitro for up to 8 weeks. Articular chondrocytes were isolated from New Zealand White rabbits and plated in monolayer cultures. The cultures were supplemented with 100 ng/mL of BMP-2 for up to 8 weeks and the extracellular matrix (ECM) composition, material properties, and messenger RNA (mRNA) expression were analyzed. mRNA expression of cartilage-specific genes, type II collagen, and aggrecan showed that BMP-2 enhanced chondrocyte stability for up to 3 weeks. After 3 weeks in culture, there was substantially more type I collagen expression and more osteopontin and runt-related transcription factor 2 expression in 5- and 8-week cultures treated with BMP-2 than in controls. Additionally, matrix metalloproteinase-13 and ADAMTS-5 (A disintegrin-like and metalloproteinase with thrombospondin 5) were upregulated in 5- and 8-week cultures treated with BMP-2, coinciding with a loss of ECM density, collagen, and proteoglycan. Eight-week tissue stimulated with BMP-2 was more fragile and tore more easily when removed from the culture dish as compared to controls, suggesting temporal limitations to the effectiveness of BMP-2 in monolayer systems and perhaps other models to enhance the generation of a cartilage-like tissue for tissue engineering purposes.

  17. Bone marrow-derived myofibroblasts are the providers of pro-invasive matrix metalloproteinase 13 in primary tumor

    DEFF Research Database (Denmark)

    Lecomte, Julie; Masset, Anne; Blacher, Silvia

    2012-01-01

    producing cells were exclusively α-SMA(+) cells and derived from GFP(+) BM cells. To investigate their impact on tumor invasion, we isolated mesenchymal stem cells (MSCs) from the BM of wild-type and MMP13-deficient mice. Wild-type MSC promoted cancer cell invasion in a spheroid assay, whereas MSCs obtained......)-derived cells to generate different fibroblast subsets that putatively produce the matrix metalloproteinase 13 (MMP13) and affect cancer cell invasion. A murine model of skin carcinoma was applied to mice, irradiated, and engrafted with BM isolated from green fluorescent protein (GFP) transgenic mice. We...

  18. Odontogenic Differentiation of Human Dental Pulp Stem Cells on Hydrogel Scaffolds Derived from Decellularized Bone Extracellular Matrix and Collagen Type I.

    Science.gov (United States)

    Paduano, Francesco; Marrelli, Massimo; White, Lisa J; Shakesheff, Kevin M; Tatullo, Marco

    2016-01-01

    The aim of this study was to evaluate the level of odontogenic differentiation of dental pulp stem cells (DPSCs) on hydrogel scaffolds derived from bone extracellular matrix (bECM) in comparison to those seeded on collagen I (Col-I), one of the main components of dental pulp ECM. DPSCs isolated from human third molars were characterized for surface marker expression and odontogenic potential prior to seeding into bECM or Col-I hydrogel scaffolds. The cells were then seeded onto bECM and Col-I hydrogel scaffolds and cultured under basal conditions or with odontogenic and growth factor (GF) supplements. DPSCs cultivated on tissue culture polystyrene (TCPS) with and without supplements were used as controls. Gene expression of dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP-1) and matrix extracellular phosphoglycoprotein (MEPE) was evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and mineral deposition was observed by Von Kossa staining. When DPSCs were cultured on bECM hydrogels, the mRNA expression levels of DSPP, DMP-1 and MEPE genes were significantly upregulated with respect to those cultured on Col-I scaffolds or TCPS in the absence of extra odontogenic inducers. In addition, more mineral deposition was observed on bECM hydrogel scaffolds as demonstrated by Von Kossa staining. Moreover, DSPP, DMP-1 and MEPE mRNA expressions of DPSCs cultured on bECM hydrogels were further upregulated by the addition of GFs or osteo/odontogenic medium compared to Col-I treated cells in the same culture conditions. These results demonstrate the potential of the bECM hydrogel scaffolds to stimulate odontogenic differentiation of DPSCs.

  19. Use of the submerged demineralizer system at Three Mile Island

    International Nuclear Information System (INIS)

    Hofstetter, K.J.; Hitz, C.G.

    1983-01-01

    The Submerged Demineralizer System (SDS) has been used at Three Mile Island-Unit 2 (TMI-2) to process more than 1.5 million gallons of water contaminated as a result of the March, 1979 accident. The SDS has processed approximately 315,000 gallons of water accumulated in tanks in the Auxiliary Building, approximately 650,000 gallons of water that existed in the Reactor Containment Building basement, approximately 90,000 gallons of primary reactor coolant (processed in a bleed and feed mode) and approximately 169,000 gallons of water used in the large scale decontamination of the Reactor Building. During its operation, the SDS has immobilized approximately 340,000 curies of the principal fission products 137 Cs, 134 Cs and 90 Sr on inorganic media (zeolite). Processing summaries and performance evaluations are presented. 12 references, 1 figure, 6 tables

  20. Microstructural analysis of demineralized primary enamel after in vitro toothbrushing

    Directory of Open Access Journals (Sweden)

    Neves Aline de Almeida

    2002-01-01

    Full Text Available The aim of this study was to investigate, in vitro, the morphological characteristics of demineralized primary enamel subjected to brushing with a dentifrice with or without fluoride. In order to do so, 32 enamel blocks were divided in 4 different groups containing 8 blocks each. They were separately immersed in artificial saliva for 15 days. The experimental groups were: C - control; E - submitted to etching with 37% phosphoric acid gel (30 s; EB - submitted to etching and brushing 3 times a day with a non-fluoridated dentifrice; EBF = submitted to etching and brushing 3 times a day with a fluoridated dentifrice. The toothbrushing force was standardized at 0.2 kgf and 15 double strokes were performed on each block. After the experimental period, the samples were prepared and examined under SEM. The control group (C showed a smooth surface, presenting scratches caused by habitual toothbrushing. The etched samples (E exhibited different degrees of surface disintegration, but the pattern of acid etching was predominantly the type II dissolution. The brushed surfaces were smooth, with elevations which corresponded to the exposure of Tomes? process pits and depressions which corresponded to interrod enamel. Particles resembling calcium carbonate were found in the most protected parts of the grooves. No morphological differences were observed between brushing with fluoridated (EBF and non-fluoridated (EB dentifrice. The results suggest that the mechanical abrasion caused by brushing demineralized enamel with dentifrice smoothes the rough etched surface, and the presence of fluoride does not cause morphological modifications in this pattern.

  1. Effect of modifications in mineralized collagen fibril and extra-fibrillar matrix material properties on submicroscale mechanical behavior of cortical bone.

    Science.gov (United States)

    Wang, Yaohui; Ural, Ani

    2018-06-01

    A key length scale of interest in assessing the fracture resistance of bone is the submicroscale which is composed of mineralized collagen fibrils (MCF) and extra-fibrillar matrix (EFM). Although the processes through which the submicroscale constituents of bone contribute to the fracture resistance in bone have been identified, the extent of the modifications in submicroscale mechanical response due to the changes in individual properties of MCFs and EFM has not been determined. As a result, this study aims to quantify the influence of individual MCF and EFM material property modifications on the mechanical behavior (elastic modulus, ultimate strength, and resistance to failure) of bone at the submicroscale using a novel finite element modeling approach that incorporate 3D networks of MCFs with three different orientations as well as explicit representation of EFM. The models were evaluated under tensile loading in transverse (representing MCF separation) and longitudinal (representing MCF rupture) directions. The results showed that the apparent elastic modulus at the submicroscale under both loading directions for all orientations was only affected by the change in the elastic modulus of MCFs. MCF separation and rupture strengths were mainly dependent on the ultimate strength of EFM and MCFs, respectively, with minimal influence of other material properties. The extent of damage during MCF separation increased with increasing ultimate strength of EFM and decreased with increasing fracture energy of EFM with minimal contribution from elastic modulus of MCFs. For MCF rupture, there was an almost one-to-one linear relationship between the percent change in fracture energy of MCFs and the percent change in the apparent submicroscale fracture energy. The ultimate strength and elastic modulus of MCFs had moderate to limited influence on the MCF rupture fracture energy. The results of this study quantified the extent of changes that may be seen in the energy

  2. Decreased hypertrophic differentiation accompanies enhanced matrix formation in co-cultures of outer meniscus cells with bone marrow mesenchymal stromal cells

    Science.gov (United States)

    2012-01-01

    Introduction The main objective of this study was to determine whether meniscus cells from the outer (MCO) and inner (MCI) regions of the meniscus interact similarly to or differently with mesenchymal stromal stem cells (MSCs). Previous study had shown that co-culture of meniscus cells with bone marrow-derived MSCs result in enhanced matrix formation relative to mono-cultures of meniscus cells and MSCs. However, the study did not examine if cells from the different regions of the meniscus interacted similarly to or differently with MSCs. Methods Human menisci were harvested from four patients undergoing total knee replacements. Tissue from the outer and inner regions represented pieces taken from one third and two thirds of the radial distance of the meniscus, respectively. Meniscus cells were released from the menisci after collagenase treatment. Bone marrow MSCs were obtained from the iliac crest of two patients after plastic adherence and in vitro culture until passage 2. Primary meniscus cells from the outer (MCO) or inner (MCI) regions of the meniscus were co-cultured with MSCs in three-dimensional (3D) pellet cultures at 1:3 ratio, respectively, for 3 weeks in the presence of serum-free chondrogenic medium containing TGF-β1. Mono-cultures of MCO, MCI and MSCs served as experimental control groups. The tissue formed after 3 weeks was assessed biochemically, histochemically and by quantitative RT-PCR. Results Co-culture of inner (MCI) or outer (MCO) meniscus cells with MSCs resulted in neo-tissue with increased (up to 2.2-fold) proteoglycan (GAG) matrix content relative to tissues formed from mono-cultures of MSCs, MCI and MCO. Co-cultures of MCI or MCO with MSCs produced the same amount of matrix in the tissue formed. However, the expression level of aggrecan was highest in mono-cultures of MSCs but similar in the other four groups. The DNA content of the tissues from co-cultured cells was not statistically different from tissues formed from mono-cultures of

  3. Fourier transform infrared imaging of femoral neck bone: reduced heterogeneity of mineral-to-matrix and carbonate-to-phosphate and more variable crystallinity in treatment-naive fracture cases compared with fracture-free controls.

    Science.gov (United States)

    Gourion-Arsiquaud, Samuel; Lukashova, Lyudmilla; Power, Jon; Loveridge, Nigel; Reeve, Jonathan; Boskey, Adele L

    2013-01-01

    After the age of 60 years, hip fracture risk strongly increases, but only a fifth of this increase is attributable to reduced bone mineral density (BMD, measured clinically). Changes in bone quality, specifically bone composition as measured by Fourier transform infrared spectroscopic imaging (FTIRI), also contribute to fracture risk. Here, FTIRI was applied to study the femoral neck and provide spatially derived information on its mineral and matrix properties in age-matched fractured and nonfractured bones. Whole femoral neck cross sections, divided into quadrants along the neck's axis, from 10 women with hip fracture and 10 cadaveric controls were studied using FTIRI and micro-computed tomography. Although 3-dimensional micro-CT bone mineral densities were similar, the mineral-to-matrix ratio was reduced in the cases of hip fracture, confirming previous reports. New findings were that the FTIRI microscopic variation (heterogeneity) of the mineral-to-matrix ratio was substantially reduced in the fracture group as was the heterogeneity of the carbonate-to-phosphate ratio. Conversely, the heterogeneity of crystallinity was increased. Increased variation of crystallinity was statistically associated with reduced variation of the carbonate-to-phosphate ratio. Anatomical variation in these properties between the different femoral neck quadrants was reduced in the fracture group compared with controls. Although our treatment-naive patients had reduced rather than increased bending resistance, these changes in heterogeneity associated with hip fracture are in another way comparable to the effects of experimental bisphosphonate therapy, which decreases heterogeneity and other indicators of bone's toughness as a material. Copyright © 2013 American Society for Bone and Mineral Research.

  4. Tissue inhibitor of matrix metalloproteinase-1 suppresses apoptosis of mouse bone marrow stromal cell line MBA-1.

    Science.gov (United States)

    Guo, L-J; Luo, X-H; Xie, H; Zhou, H-D; Yuan, L-Q; Wang, M; Liao, E-Y

    2006-05-01

    We investigated the action of tissue inhibitor of metalloproteinase-1 (TIMP-1) on apoptosis and differentiation of mouse bone marrow stromal cell line MBA-1. TIMP-1 did not affect alkaline phosphatase (ALP) activity, suggesting that it is not involved in osteoblastic differentiation in MBA-1 cells. However, TIMP-1 inhibited MBA-1 apoptosis induced by serum deprivation in a dose-dependent manner. Our study also showed increased Bcl-2 protein expression and decreased Bax protein expression with TIMP-1 treatment. TIMP-1 decreased cytochrome c release and caspase-3 activation in MBA-1 cells. TIMP-1 activated phosphatidylinositol 3-kinase (PI3-kinase) and c-Jun N-terminal kinase (JNK), and the PI3-kinase inhibitor LY294002 or the JNK inhibitor SP600125 abolished its antiapoptotic activity. To investigate whether antiapoptotic action of TIMP-1 was mediated through its inhibition on MMP activities, we constructed mutant TIMP-1 by side-directed mutagenesis, which abolished the inhibitory activity of MMPs by deletion of Cys1 to Ala4. Wild-type TIMP-1 and mutant TIMP-1 expression plasmids were transfected in MBA-1 cells, and results showed that mutant TIMP-1 still protected the induced MBA-1 cell against apoptosis. These data suggest that TIMP-1 antiapoptotic actions are mediated via the PI3-kinase and JNK signaling pathways and independent of TIMP-1 inhibition of MMP activities.

  5. Effect of demineralization on the physiochemical structure and thermal degradation of acid treated indigenous rice husk

    Directory of Open Access Journals (Sweden)

    Aslam Umair

    2016-09-01

    Full Text Available Energy generation from biomass presents some serious problems like slagging, fouling and corrosion of boilers. To address these problems, demineralization of biomass is performed using different leaching agents. This study is focused on determining the influence of leaching agents and leaching time on the physiochemical structure of rice husk during demineralization. Dilute (5% wt solutions of HCl and H2SO4 were used for the demineralization of rice husk separately with leaching time of 15, 60 and 120 minutes. It is shown that H2SO4 exhibited higher removal of alkali and alkaline earth metals (AAEM comparatively as depicted by the 34.2% decrease in ash content along with an increase of 7.10% in the heating value. The acid has been seen to induce more notable changes in physiochemical structure as depicted by the FTIR spectra and SEM micrographs. The thermal degradation behavior of the demineralized rice husk has also been reported.

  6. In vitro demineralization of enamel by orange juice, apple juice, Pepsi Cola and Diet Pepsi Cola.

    Science.gov (United States)

    Grobler, S R; Senekal, P J; Laubscher, J A

    1990-12-01

    Enamel demineralization was studied over periods related to normal use of an orange juice, an apple juice, Pepsi Cola and Diet Pepsi Cola. Rectangular blocks of intact human enamel (3 mm x 3 mm) were cut from teeth, coated with nail varnish except for the enamel surface and exposed to the drinks for 2, 4, 5, 6 or 40 minutes. The amount of calcium released from the enamel into solution was determined with the use of an atomic absorption spectrophotometer. The results showed the following degree of enamel demineralization: Pepsi Cola = orange juice greater than apple juice greater than Diet Pepsi Cola. The results suggest that diet colas are less demineralizing than other acid drinks, and complementary plaque studies indicate that they are also less cariogenic. The study emphasized the importance of acid-type, buffer capacity, pH and the presence of other components on the degree of enamel demineralization.

  7. Removal of different fractions of NOM foulants during demineralized water backwashing

    KAUST Repository

    Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Verliefde, Arne R. D.; Amy, Gary L.; Van Dijk, Johannis C.

    2012-01-01

    The effectiveness of demineralized water backwashing on fouling by different fractions of NOM was investigated in this study. Two types of natural surface water (Schie canal and Biesbosch reservoir) were tested to confirm the improvement

  8. Co-culture of chondrocytes and bone marrow mesenchymal stem cells in vitro enhances the expression of cartilaginous extracellular matrix components

    Directory of Open Access Journals (Sweden)

    Chang Qing

    2011-04-01

    Full Text Available Chondrocytes and bone marrow mesenchymal stem cells (BMSCs are frequently used as seed cells in cartilage tissue engineering. In the present study, we determined if the co-culture of rabbit articular chondrocytes and BMSCs in vitro promotes the expression of cartilaginous extracellular matrix and, if so, what is the optimal ratio of the two cell types. Cultures of rabbit articular chondrocytes and BMSCs were expanded in vitro and then cultured individually or at a chondrocyte:BMSC ratio of 4:1, 2:1, 1:1, 1:2, 1:4 for 21 days and cultured in DMEM/F12. BMSCs were cultured in chondrogenic induction medium. Quantitative real-time RT-PCR and Western blot were used to evaluate gene expression. In the co-cultures, type II collagen and aggrecan expression increased on days 14 and 21. At the mRNA level, the expression of type II collagen and aggrecan on day 21 was much higher in the 4:1, 2:1, and 1:1 groups than in either the articular chondrocyte group or the induced BMSC group, and the best ratio of co-culture groups seems to be 2:1. Also on day 21, the expression of type II collagen and aggrecan proteins in the 2:1 group was much higher than in all other groups. The results demonstrate that the co-culture of rabbit chondrocytes and rabbit BMSCs at defined ratios can promote the expression of cartilaginous extracellular matrix. The optimal cell ratio appears to be 2:1 (chondrocytes:BMSCs. This approach has potential applications in cartilage tissue engineering since it provides a protocol for maintaining and promoting seed-cell differentiation and function.

  9. Co-culture of chondrocytes and bone marrow mesenchymal stem cells in vitro enhances the expression of cartilaginous extracellular matrix components.

    Science.gov (United States)

    Qing, Chang; Wei-ding, Cui; Wei-min, Fan

    2011-04-01

    Chondrocytes and bone marrow mesenchymal stem cells (BMSCs) are frequently used as seed cells in cartilage tissue engineering. In the present study, we determined if the co-culture of rabbit articular chondrocytes and BMSCs in vitro promotes the expression of cartilaginous extracellular matrix and, if so, what is the optimal ratio of the two cell types. Cultures of rabbit articular chondrocytes and BMSCs were expanded in vitro and then cultured individually or at a chondrocyte:BMSC ratio of 4:1, 2:1, 1:1, 1:2, 1:4 for 21 days and cultured in DMEM/F12. BMSCs were cultured in chondrogenic induction medium. Quantitative real-time RT-PCR and Western blot were used to evaluate gene expression. In the co-cultures, type II collagen and aggrecan expression increased on days 14 and 21. At the mRNA level, the expression of type II collagen and aggrecan on day 21 was much higher in the 4:1, 2:1, and 1:1 groups than in either the articular chondrocyte group or the induced BMSC group, and the best ratio of co-culture groups seems to be 2:1. Also on day 21, the expression of type II collagen and aggrecan proteins in the 2:1 group was much higher than in all other groups. The results demonstrate that the co-culture of rabbit chondrocytes and rabbit BMSCs at defined ratios can promote the expression of cartilaginous extracellular matrix. The optimal cell ratio appears to be 2:1 (chondrocytes:BMSCs). This approach has potential applications in cartilage tissue engineering since it provides a protocol for maintaining and promoting seed-cell differentiation and function.

  10. In vitro mesenchymal trilineage differentiation and extracellular matrix production by adipose and bone marrow derived adult equine multipotent stromal cells on a collagen scaffold.

    Science.gov (United States)

    Xie, Lin; Zhang, Nan; Marsano, Anna; Vunjak-Novakovic, Gordana; Zhang, Yanru; Lopez, Mandi J

    2013-12-01

    Directed differentiation of adult multipotent stromal cells (MSC) is critical for effective treatment strategies. This study was designed to evaluate the capability of equine MSC from bone marrow (BMSC) and adipose tissue (ASC) on a type I collagen (COLI) scaffold to undergo chondrogenic, osteogenic and adipogenic differentiation and form extracellular matrix (ECM) in vitro. Following determination of surface antigen expression, MSC were loaded into scaffolds in a perfusion bioreactor and loading efficiency was quantified. Cell-scaffold constructs were assessed after loading and 7, 14 and 21 days of culture in stromal or induction medium. Cell number was determined with DNA content, cell viability and spatial uniformity with confocal laser microscopy and cell phenotype and matrix production with light and scanning electron microscopy and mRNA levels. The MSC were positive for CD29 (>90 %), CD44 (>99 %), and CD105 (>60 %). Loading efficiencies were >70 %. The ASC and BMSC cell numbers on scaffolds were affected by culture in induction medium differently. Viable cells remained uniformly distributed in scaffolds for up to 21 days and could be directed to differentiate or to maintain an MSC phenotype. Micro- and ultrastructure showed lineage-specific cell and ECM changes. Lineage-specific mRNA levels differed between ASC and BMSC with induction and changed with time. Based on these results, equine ASC and BMSC differentiate into chondrogenic, osteogenic and adipogenic lineages and form ECM similarly on COLI scaffolds. The collected data supports the potential for equine MSC-COLI constructs to support diverse equine tissue formation for controlled biological studies.

  11. Thrombospondin-2 promotes prostate cancer bone metastasis by the up-regulation of matrix metalloproteinase-2 through down-regulating miR-376c expression

    Directory of Open Access Journals (Sweden)

    Po-Chun Chen

    2017-01-01

    Full Text Available Abstract Background Thrombospondin-2 (TSP-2 is a secreted matricellular glycoprotein that is found to mediate cell-to-extracellular matrix attachment and participates in many physiological and pathological processes. The expression profile of TSP-2 on tumors is controversial, and it up-regulates in some cancers, whereas it down-regulates in others, suggesting that the functional role of TSP-2 on tumors is still uncertain. Methods The expression of TSP-2 on prostate cancer progression was determined in the tissue array by the immunohistochemistry. The molecular mechanism of TSP-2 on prostate cancer (PCa metastasis was investigated through pharmaceutical inhibitors, siRNAs, and miRNAs analyses. The role of TSP-2 on PCa metastasis in vivo was verified through xenograft in vivo imaging system. Results Based on the gene expression omnibus database and immunohistochemistry, we found that TSP-2 increased with the progression of PCa, especially in metastatic PCa and is correlated with the matrix metalloproteinase-2 (MMP-2 expression. Additionally, through binding to CD36 and integrin ανβ3, TSP-2 increased cell migration and MMP-2 expression. With inhibition of p38, ERK, and JNK, the TSP-2-induced cell migration and MMP-2 expression were abolished, indicating that the TSP-2’s effect on PCa is MAPK dependent. Moreover, the microRNA-376c (miR-376c was significantly decreased by the TSP-2 treatment. Furthermore, the TSP-2-induced MMP-2 expression and the subsequent cell motility were suppressed upon miR-376c mimic stimulation. On the other hand, the animal studies revealed that the bone metastasis was abolished when TSP-2 was stably knocked down in PCa cells. Conclusions Taken together, our results indicate that TSP-2 enhances the migration of PCa cells by increasing MMP-2 expression through down-regulation of miR-376c expression. Therefore, TSP-2 may represent a promising new target for treating PCa.

  12. Enhanced hyaline cartilage matrix synthesis in collagen sponge scaffolds by using siRNA to stabilize chondrocytes phenotype cultured with bone morphogenetic protein-2 under hypoxia.

    Science.gov (United States)

    Legendre, Florence; Ollitrault, David; Hervieu, Magalie; Baugé, Catherine; Maneix, Laure; Goux, Didier; Chajra, Hanane; Mallein-Gerin, Frédéric; Boumediene, Karim; Galera, Philippe; Demoor, Magali

    2013-07-01

    Cartilage healing by tissue engineering is an alternative strategy to reconstitute functional tissue after trauma or age-related degeneration. However, chondrocytes, the major player in cartilage homeostasis, do not self-regenerate efficiently and lose their phenotype during osteoarthritis. This process is called dedifferentiation and also occurs during the first expansion step of autologous chondrocyte implantation (ACI). To ensure successful ACI therapy, chondrocytes must be differentiated and capable of synthesizing hyaline cartilage matrix molecules. We therefore developed a safe procedure for redifferentiating human chondrocytes by combining appropriate physicochemical factors: hypoxic conditions, collagen scaffolds, chondrogenic factors (bone morphogenetic protein-2 [BMP-2], and insulin-like growth factor I [IGF-I]) and RNA interference targeting the COL1A1 gene. Redifferentiation of dedifferentiated chondrocytes was evaluated using gene/protein analyses to identify the chondrocyte phenotypic profile. In our conditions, under BMP-2 treatment, redifferentiated and metabolically active chondrocytes synthesized a hyaline-like cartilage matrix characterized by type IIB collagen and aggrecan molecules without any sign of hypertrophy or osteogenesis. In contrast, IGF-I increased both specific and noncharacteristic markers (collagens I and X) of chondrocytes. The specific increase in COL2A1 gene expression observed in the BMP-2 treatment was shown to involve the specific enhancer region of COL2A1 that binds the trans-activators Sox9/L-Sox5/Sox6 and Sp1, which are associated with a decrease in the trans-inhibitors of COL2A1, c-Krox, and p65 subunit of NF-kappaB. Our procedure in which BMP-2 treatment under hypoxia is associated with a COL1A1 siRNA, significantly increased the differentiation index of chondrocytes, and should offer the opportunity to develop new ACI-based therapies in humans.

  13. EXPERIMENTAL DEVELOPMENT OF BIO-BASED POLYMER MATRIX BUILDING MATERIAL AND FISH BONE DIAGRAM FOR MATERIAL EFFECT ON QUALITY

    Directory of Open Access Journals (Sweden)

    Asmamaw Tegegne

    2014-06-01

    Full Text Available These days cost of building materials are continuously increasing and the conventional construction materials for this particular purpose become low and low. The weight of conventional construction materials particularly building block is heavy and costly due to particularly cement. Thus, the objective of this paper is to develop an alternative light weight, high strength and relatively cost effective building material that satisfy the quality standard used in the country. A bio-based polymer matrix composite material for residential construction was experimentally developed. Sugar cane bagasse, thermoplastics (polyethylene g roup sand and red ash were used as materials alternatively. Mixing of the additives,melting of the hermoplastics, molding and curing (dryingwere the common methods used on the forming process of the samples. Mechanical behavior evaluation (testing of the product was carried out. Totally 45 specimens were produced and three replicate tests were performed per each test type. Quality analysis was carried out for group B material using Ishikawa diagram. The tensile strength of group A specimen was approximately 3 times greater than that of group B specimens. The compression strength of group A specimens were nearly 2 times greater than group B. Comparing to the conventional building materials(concert block and agrostoneproduced in the country, which the compression strength is 7Mpa and 16Mpa respectively, the newly produced materials show much better results in which Group A is 25.66 Mpa and group B is 16.66 Mpa. energy absorption capacity of group A specimens was approximately 3 times better than that of group B. Water absorption test was carried out for both groups and both showed excellent resistivity. Group A composite material specimens, showed better results in all parameters.

  14. Enamel matrix protein derivative plus synthetic bone substitute for the treatment of mandibular Class II furcation defects: a case series.

    Science.gov (United States)

    Queiroz, Lucas Araujo; Santamaria, Mauro; Casati, Marcio; Silverio, Karina; Nociti-Junior, Francisco; Sallum, Enilson

    2015-03-01

    The aim of this study is to report on the treatment of mandibular Class II furcation defects with enamel matrix protein derivative (EMD) combined with a βTCP/HA (β-tricalcium phosphate/hydroxyapatite) alloplastic material. Thirteen patients were selected. All patients were nonsmokers, systemically healthy, and diagnosed with chronic periodontitis; had not taken medications known to interfere with periodontal tissue health and healing; presented one Class II mandibular furcation defect with horizontal probing equal to or greater than 4 mm at buccal site. The clinical parameters evaluated were probing depth (PD), relative gingival margin position (RGMP), relative vertical clinical attachment level (RVCAL), and relative horizontal clinical attachment level (RHCAL). A paired Student t test was used to detect differences between the baseline and 6-month measurements, with the level of significance of .05. After 6 months, the treatment produced a statistically significant reduction in PD and a significant gain in RVCAL and RHCAL, but no observable change in RGMP. RVCAL ranged from 13.77 (± 1.31) at baseline to 12.15 (± 1.29) after 6 months, with a mean change of -1.62 ± 1.00 mm (P < .05). RHCAL ranged from 5.54 (± 0.75) to 2.92 (± 0.92), with a mean change of -2.62 ± 0.63 mm (P < .05). After 6 months, 76.92% of the patients improved their diagnosis to Class I furcation defects while 23.08% remained as Class II. The present study has shown that positive clinical results may be expected from the combined treatment of Class II furcation defects with EMD and βTCP/HA, especially considering the gain of horizontal attachment level. Despite this result, controlled clinical studies are needed to confirm our outcomes.

  15. Experimentally-based multiscale model of the elastic moduli of bovine trabecular bone and its constituents

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, Elham [University of Illinois at Urbana-Champaign, Department of Mechanical Science and Engineering, 1206 West Green Street, Urbana, IL 61801 (United States); Novitskaya, Ekaterina, E-mail: eevdokim@ucsd.edu [University of California, San Diego, Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Li, Jun; Jasiuk, Iwona [University of Illinois at Urbana-Champaign, Department of Mechanical Science and Engineering, 1206 West Green Street, Urbana, IL 61801 (United States); McKittrick, Joanna [University of California, San Diego, Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, 9500 Gilman Dr., La Jolla, CA 92093 (United States)

    2015-09-01

    The elastic moduli of trabecular bone were modeled using an analytical multiscale approach. Trabecular bone was represented as a porous nanocomposite material with a hierarchical structure spanning from the collagen–mineral level to the trabecular architecture level. In parallel, compression testing was done on bovine femoral trabecular bone samples in two anatomical directions, parallel to the femoral neck axis and perpendicular to it, and the measured elastic moduli were compared with the corresponding theoretical results. To gain insights on the interaction of collagen and minerals at the nanoscale, bone samples were deproteinized or demineralized. After such processing, the treated samples remained as self-standing structures and were tested in compression. Micro-computed tomography was used to characterize the hierarchical structure of these three bone types and to quantify the amount of bone porosity. The obtained experimental data served as inputs to the multiscale model and guided us to represent bone as an interpenetrating composite material. Good agreement was found between the theory and experiments for the elastic moduli of the untreated, deproteinized, and demineralized trabecular bone. - Highlights: • A multiscale model was used to predict the elastic moduli of trabecular bone. • Samples included demineralized, deproteinized and untreated bone. • The model portrays bone as a porous, interpenetrating two phase composite. • The experimental elastic moduli for trabecular bone fell between theoretical bounds.

  16. Experimentally-based multiscale model of the elastic moduli of bovine trabecular bone and its constituents

    International Nuclear Information System (INIS)

    Hamed, Elham; Novitskaya, Ekaterina; Li, Jun; Jasiuk, Iwona; McKittrick, Joanna

    2015-01-01

    The elastic moduli of trabecular bone were modeled using an analytical multiscale approach. Trabecular bone was represented as a porous nanocomposite material with a hierarchical structure spanning from the collagen–mineral level to the trabecular architecture level. In parallel, compression testing was done on bovine femoral trabecular bone samples in two anatomical directions, parallel to the femoral neck axis and perpendicular to it, and the measured elastic moduli were compared with the corresponding theoretical results. To gain insights on the interaction of collagen and minerals at the nanoscale, bone samples were deproteinized or demineralized. After such processing, the treated samples remained as self-standing structures and were tested in compression. Micro-computed tomography was used to characterize the hierarchical structure of these three bone types and to quantify the amount of bone porosity. The obtained experimental data served as inputs to the multiscale model and guided us to represent bone as an interpenetrating composite material. Good agreement was found between the theory and experiments for the elastic moduli of the untreated, deproteinized, and demineralized trabecular bone. - Highlights: • A multiscale model was used to predict the elastic moduli of trabecular bone. • Samples included demineralized, deproteinized and untreated bone. • The model portrays bone as a porous, interpenetrating two phase composite. • The experimental elastic moduli for trabecular bone fell between theoretical bounds

  17. Morphology and thickness of the diffusion of resin through demineralized or unconditioned dentinal matrix

    Directory of Open Access Journals (Sweden)

    Arrais César Augusto Galvão

    2002-01-01

    Full Text Available The formation of a hybrid layer is the main bonding mechanism of current dentin-bonding systems. This study evaluated the morphology and thickness of the resin-infiltrated dentinal layer after the application of adhesive systems. The dentin-bonding agents were evaluated on flat dentinal preparations confected on the occlusal surfaces of human teeth. The test specimens were prepared and inspected under scanning electron microscopy at a magnification of X 2,000. The adhesive systems were responsible for different hybrid layer thicknesses (p < 0.05, and the mean values were: for Scotchbond MP Plus (SM, 7.41 ± 1.24mum; for Single Bond (SB, 5.55 ± 0.82mum; for Etch & Prime 3.0 (EP, 3.86 ± 1.17mum; and for Clearfil SE Bond (CB, 1.22 ± 0.45mum. The results suggest that the conventional three-step adhesive system (SM was responsible for the thickest hybrid layer, followed by the one-bottle adhesive (SB. The self-etching adhesives, EP and CB, produced the formation of the thinnest hybrid layers.

  18. Expression of bone morphogenic protein 2/4, transforming growth factor-β1, and bone matrix protein expression in healing area between vascular tibia grafts and irradiated bone-experimental model of osteonecrosis

    International Nuclear Information System (INIS)

    Schultze-Mosgau, Stefan; Lehner, Bernhard; Roedel, Franz; Wehrhan, Falk; Amann, Kerstin; Kopp, Juergen; Thorwarth, Michael; Nkenke, Emeka; Grabenbauer, Gerhard

    2005-01-01

    Purpose: For the surgical treatment of osteoradionecrosis after multimodal therapy of head-and-neck cancers, free vascular bone grafts are used to reconstruct osseous structures in the previously irradiated graft bed. Reduced, or even absent osseous healing in the transition area between the vascular graft and the irradiated graft bed represents a clinical problem. Inflammatory changes and fibrosis lead to delayed healing, triggered by bone morphogentic protein 2/4 (BMP2/4) and transforming growth factor (TGF)-β 1 . Given the well-known fibrosis-inducing activity of TGF-β 1 , an osteoinductive effect has been reported for BMP2/4. However, the influence of irradiation (RT) on this cytokine expression remains elusive. Therefore, the aim of the present in vivo study was to analyze the expression of BMP2/4, TGF-β 1 , collagen I, and osteocalcin in the transition area between the bone graft and the graft bed after RT. Methods and materials: Twenty Wistar rats (male, weight 300-500 g) were used in this study. A free vascular tibia graft was removed in all rats and maintained pedicled in the groin region. Ten rats underwent RT with 5 x 10 Gy to the right tibia, the remainder served as controls. After 4 weeks, the previously removed tibia grafts were regrafted into the irradiated (Group 1) and nonirradiated (Group 2) graft beds. The interval between RT and grafting was 4 weeks. After a 4-week osseous healing period, the bone grafts were removed, and the transition area between the nonirradiated graft and the irradiated osseous graft bed was examined histomorphometrically (National Institutes of Health imaging program) and immunohistochemically (avidin-biotin-peroxidase complex) for the expression of BMP2/4, TGF-β 1 , collagen I, and osteocalcin. Results: Absent or incomplete osseous healing of the graft was found in 9 of 10 rats after RT with 50 Gy and in 1 of 10 of the rats with nonirradiated osseous grafts. Histomorphometrically, the proportion of osseous healing in

  19. Treatment of unicameral bone cyst: systematic review and meta analysis.

    Science.gov (United States)

    Kadhim, Muayad; Thacker, Mihir; Kadhim, Amjed; Holmes, Laurens

    2014-03-01

    Different treatment modalities have been utilized to treat unicameral bone cyst (UBC), but evidence has not been fully described to support one treatment over another and the optimal treatment is controversial. The aim of this quantitative systematic review was to assess the effectiveness of different UBC treatment modalities. We utilized Pubmed to isolate retrospective studies on patients with UBC who received any kind of treatment. The included studies needed to have a minimum sample size of 15 patients, and have provided data on radiographic healing outcome. Sixty-two articles were selected for the meta-analysis from a total of 463 articles. The cumulative sample size was 3,211 patients with 3,217 UBC, and male to female ratio was 2.2:1. The summary or pool estimate of methylprednisolone acetate (MPA) injection resulted in a healing rate of (77.4 %) that was comparable to bone marrow injection (77.9 %). A higher healing rate was observed with MPA injection when inner wall disruption was performed. The pool estimate of bone marrow with demineralized bone matrix injection was high (98.7 %). UBC healing rate after surgical curettage was comparable whether autograft or allograft was utilized (90 %). UBC treatment with flexible intramedullary nails without curettage provided almost 100% healing rate, while continuous decompression with cannulated screws provided 89 % healing rate. Conservative treatment indicated a healing rate of 64.2, 95 % CI (26.7-101.8). Active treatment for UBC provided variable healing rates and the outcomes were favorable relative to conservative treatment. Due to the heterogeneity of the studies and reporting bias, the interpretation of these findings should be handled with caution.

  20. Seawater ultrafiltration fouling control: Backwashing with demineralized water/SWRO permeate

    KAUST Repository

    Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Amy, Gary L.; Van Dijk, Johannis C.

    2012-01-01

    In this study, the effect of demineralized water backwashing on fouling control of seawater ultrafiltration was investigated. Seawater from Scheveningen beach in The Hague and a desalination plant of Evides Company at Zeeland in the Netherlands was used as feed water, while demineralized water and UF permeate were used as backwash water for a fouling control efficiency comparison under different fluxes and backwash durations. Furthermore, demineralized waters with 5 or 50 mmol/l NaCl were applied for backwashing as well, to check the influence of monovalent cations on UF fouling control. Additionally, SWRO permeate was used for backwashes in long-term experiments to check the possibility of it replacing demineralized water. Results show that seawater UF fouling control is substantially improved by demineralized water backwashing. However, due to the high salinity of seawater, more water was required to dilute the cation concentration and limit the dispersion effect near the membrane surface than was needed for surface water. A 2-min demineralized water backwash showed better fouling control efficiency than a 1-min backwash. Furthermore, the presence of monovalent cations in the backwash water deteriorated the fouling control efficiency of the backwash, indicating the existence of a charge screening effect. The demineralized water with 5 and 50 mmol/l NaCl both showed a similar fouling control efficiency which is better than the UF permeate backwash. The calcium ions in UF permeate probably deteriorates the fouling control efficiency by maintaining a Ca-bridging effect between the membranes and NOM. SWRO permeate backwashing successfully controls membrane fouling as well. © 2012 Elsevier B.V. All rights reserved.

  1. New ways of combating demineralization: link between classic and allopathic medicine

    Science.gov (United States)

    Idoraşi, Laura; Secoşan, Sandra Andreea; Ogodescu, Alexandru; Sinescu, Cosmin; Zaharia, Cristian; Stan, Adrian Tudor; Podoleanu, Adrian G.; Negruťiu, Meda-Lavinia

    2018-03-01

    Prevention and allopathic medicine gained attention, since it is possible for dentists to prevent demineralization, using plants and natural substances with well-known efficacy. The purpose of this study was to present new methods for teeth remineralization. It was made a selection of 10 extracted teeth, maintained in physiological serum, with no color fading, decay or demineralization. It was induced demineralization, with ortho-phosphoric acid (concentration 45 %), for one minute. The probes were visually and with optical coherence tomography (OCT) inspected. The natural product and the bonding with additional nanoparticles of argent were created and applied on the demineralization zone of the both groups of teeth. Each tooth in the first group had one plain surface demineralized. The second group of teeth had a cavity prepared on one of each tooth's side. The pastes were applied on the demineralized surfaces and in the demineralized cavities for two minutes. After time expired, the pasta applied on the first group of teeth was washed away; the bonding above the second group of teeth was light cured. The probes were again visually and with OCT inspected. It was observed an improvement in remineralizing the white marks on plain surfaces and in the created cavities, the OCT being able to detect different levels of remineralization. The efficacy of natural pasta depends on the time it is applied and the concentration of the different main substances. Also, the type of surface, plain or occlusal facets, may influence the substances' penetration ability. The non-invasive specific feature of these products, low costs and safety are strong positive aspects of this method of remineralization. However, the natural process of remineralization is a long-lasting one; perfecting the main substances in order to accelerate the process, in addition to several in vivo studies would be necessary to be fulfilled.

  2. Seawater ultrafiltration fouling control: Backwashing with demineralized water/SWRO permeate

    KAUST Repository

    Li, Sheng

    2012-09-01

    In this study, the effect of demineralized water backwashing on fouling control of seawater ultrafiltration was investigated. Seawater from Scheveningen beach in The Hague and a desalination plant of Evides Company at Zeeland in the Netherlands was used as feed water, while demineralized water and UF permeate were used as backwash water for a fouling control efficiency comparison under different fluxes and backwash durations. Furthermore, demineralized waters with 5 or 50 mmol/l NaCl were applied for backwashing as well, to check the influence of monovalent cations on UF fouling control. Additionally, SWRO permeate was used for backwashes in long-term experiments to check the possibility of it replacing demineralized water. Results show that seawater UF fouling control is substantially improved by demineralized water backwashing. However, due to the high salinity of seawater, more water was required to dilute the cation concentration and limit the dispersion effect near the membrane surface than was needed for surface water. A 2-min demineralized water backwash showed better fouling control efficiency than a 1-min backwash. Furthermore, the presence of monovalent cations in the backwash water deteriorated the fouling control efficiency of the backwash, indicating the existence of a charge screening effect. The demineralized water with 5 and 50 mmol/l NaCl both showed a similar fouling control efficiency which is better than the UF permeate backwash. The calcium ions in UF permeate probably deteriorates the fouling control efficiency by maintaining a Ca-bridging effect between the membranes and NOM. SWRO permeate backwashing successfully controls membrane fouling as well. © 2012 Elsevier B.V. All rights reserved.

  3. Re- and Demineralization Characteristics of Enamel Depending on Baseline Mineral Loss and Lesion Depth in situ.

    Science.gov (United States)

    Wierichs, Richard J; Lausch, Julian; Meyer-Lueckel, Hendrik; Esteves-Oliveira, Marcella

    2016-01-01

    The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds. In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF2 and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (x0394;x0394;Z) and lesion depth (x0394;LD) were calculated between values before and after the in situ period using transversal microradiography. Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for x0394;x0394;Z of the dentifrice with 0 ppm F, sound surfaces showed significantly higher x0394;x0394;Z and x0394;LD values compared with lowly and highly demineralized lesions (p test). Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth. © 2016 S. Karger AG, Basel.

  4. Evaluation of the effect of a gamma irradiated DBM-pluronic F127 composite on bone regeneration in Wistar rat.

    Directory of Open Access Journals (Sweden)

    Tamer Al Kayal

    Full Text Available Demineralized bone matrix (DBM is widely used for bone regeneration. Since DBM is prepared in powder form its handling properties are not optimal and limit the clinical use of this material. Various synthetic and biological carriers have been used to enhance the DBM handling. In this study we evaluated the effect of gamma irradiation on the physical-chemical properties of Pluronic and on bone morphogenetic proteins (BMPs amount in DBM samples. In vivo studies were carried out to investigate the effect on bone regeneration of a gamma irradiated DBM-Pluronic F127 (DBM-PF127 composite implanted in the femur of rats. Gamma irradiation effects (25 kGy on physical-chemical properties of Pluronic F127 were investigated by rheological and infrared analysis. The BMP-2/BMP-7 amount after DBM irradiation was evaluated by ELISA. Bone regeneration capacity of DBM-PF127 containing 40% (w/w of DBM was investigated in transcortical holes created in the femoral diaphysis of Wistar rat. Bone porosity, repaired bone volume and tissue organization were evaluated at 15, 30 and 90 days by Micro-CT and histological analysis. The results showed that gamma irradiation did not induce significant modification on physical-chemical properties of Pluronic, while a decrease in BMP-2/BMP-7 amount was evidenced in sterilized DBM. Micro-CT and histological evaluation at day 15 post-implantation revealed an interconnected trabeculae network in medullar cavity and cellular infiltration and vascularization of DBM-PF127 residue. In contrast a large rate of not connected trabeculae was observed in Pluronic filled and unfilled defects. At 30 and 90 days the DBM-PF127 samples shown comparable results in term of density and thickness of the new formed tissue respect to unfilled defect. In conclusion a gamma irradiated DBM-PF127 composite, although it may have undergone a significant decrease in the concentration of BMPs, was able to maintains bone regeneration capability.

  5. Effect of the gamma radiation and common antioxidants on some aspects of osteoblast differentiation during the formation of bone tissue in an in-vivo model

    International Nuclear Information System (INIS)

    Quinones O, M. G.

    2015-01-01

    Gamma radiation is the emission of energy through short electromagnetic waves to a higher level of frequency with respect to ultraviolet light. This type of energy in the medical application is used as a tool to kill cancer cells in humans, however, adverse damages to its exposure can produce secondary effects in the short and long term depending on the damage in cells and tissues nearby to the irradiation zone, the human body will present various injuries and conditions. In bone tissue, secondary effects that have been observed, is an alteration of the architecture and integrity of bone extracellular matrix of cortical and trabecular tissue, which causes loss of bone density. However, the reason that the bone tissue is affected is not clear, but is believed to be related to the formation of free radicals, which generate oxidative damage in biomolecules of the cells, damaging the tissue structure, organs and systems of the human body. The studies to identify the main reasons that will affect bone tissue as a result of radiotherapy have been carried out by models In-vitro and some In-vivo. In most studies in-vitro with cells with osteoblast phenotype, the results suggest alterations in proliferation and differentiation of these cells. However, the etiology and the role of these changes in disorders and bone injuries as adverse secondary effects of the radiotherapy are very poorly understood to date. In the present study an In-vivo model was used, that are ectopic bone plates which are developed by endochondral ossification, after having implanted demineralized bone particles at 16 days of development, at which time they are constituted by bone tissue. Ectopic bone plates were used with the aim of knowing as gamma radiation indirectly modifies to cellular level the osteoblast differentiation, cells that are involved in the formation and mineralization of bone extracellular matrix. One of the well known effects of gamma radiation is the generation of free radicals

  6. Three dimensional printed macroporous polylactic acid/hydroxyapatite composite scaffolds for promoting bone formation in a critical-size rat calvarial defect model

    Science.gov (United States)

    Zhang, Haifeng; Mao, Xiyuan; Du, Zijing; Jiang, Wenbo; Han, Xiuguo; Zhao, Danyang; Han, Dong; Li, Qingfeng

    2016-01-01

    We have explored the applicability of printed scaffold by comparing osteogenic ability and biodegradation property of three resorbable biomaterials. A polylactic acid/hydroxyapatite (PLA/HA) composite with a pore size of 500 μm and 60% porosity was fabricated by three-dimensional printing. Three-dimensional printed PLA/HA, β-tricalcium phosphate (β-TCP) and partially demineralized bone matrix (DBM) seeded with bone marrow stromal cells (BMSCs) were evaluated by cell adhesion, proliferation, alkaline phosphatase activity and osteogenic gene expression of osteopontin (OPN) and collagen type I (COL-1). Moreover, the biocompatibility, bone repairing capacity and degradation in three different bone substitute materials were estimated using a critical-size rat calvarial defect model in vivo. The defects were evaluated by micro-computed tomography and histological analysis at four and eight weeks after surgery, respectively. The results showed that each of the studied scaffolds had its own specific merits and drawbacks. Three-dimensional printed PLA/HA scaffolds possessed good biocompatibility and stimulated BMSC cell proliferation and differentiation to osteogenic cells. The outcomes in vivo revealed that 3D printed PLA/HA scaffolds had good osteogenic capability and biodegradation activity with no difference in inflammation reaction. Therefore, 3D printed PLA/HA scaffolds have potential applications in bone tissue engineering and may be used as graft substitutes in reconstructive surgery.

  7. Bone disease in primary hyperparathyroidism

    Science.gov (United States)

    Bandeira, Francisco; Cusano, Natalie E.; Silva, Barbara C.; Cassibba, Sara; Almeida, Clarissa Beatriz; Machado, Vanessa Caroline Costa; Bilezikian, John P.

    2015-01-01

    Bone disease in severe primary hyperparathyroidism (PHPT) is described classically as osteitis fibrosa cystica (OFC). Bone pain, skeletal deformities and pathological fractures are features of OFC. Bone mineral density is usually extremely low in OFC, but it is reversible after surgical cure. The signs and symptoms of severe bone disease include bone pain, pathologic fractures, proximal muscle weakness with hyperreflexia. Bone involvement is typically characterized as salt-and-pepper appearance in the skull, bone erosions and bone resorption of the phalanges, brown tumors and cysts. In the radiography, diffuse demineralization is observed, along with pathological fractures, particularly in the long bones of the extremities. In severe, symptomatic PHPT, marked elevation of the serum calcium and PTH concentrations are seen and renal involvement is manifested by nephrolithiasis and nephrocalcinosis. A new technology, recently approved for clinical use in the United States and Europe, is likely to become more widely available because it is an adaptation of the lumbar spine DXA image. Trabecular bone score (TBS) is a gray-level textural analysis that provides an indirect index of trabecular microarchitecture. Newer technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), have provided further understanding of the microstructural skeletal features in PHPT. PMID:25166047

  8. Bone marker gene expression in calvarial bones: different bone microenvironments.

    Science.gov (United States)

    Al-Amer, Osama

    2017-12-01

    In calvarial mice, mesenchymal stem cells (MSCs) differentiate into osteoprogenitor cells and then differentiate into osteoblasts that differentiate into osteocytes, which become embedded within the bone matrix. In this case, the cells participating in bone formation include MSCs, osteoprogenitor cells, osteoblasts and osteocytes. The calvariae of C57BL/KaLwRijHsD mice consist of the following five bones: two frontal bones, two parietal bones and one interparietal bone. This study aimed to analyse some bone marker genes and bone related genes to determine whether these calvarial bones have different bone microenvironments. C57BL/KaLwRijHsD calvariae were carefully excised from five male mice that were 4-6 weeks of age. Frontal, parietal, and interparietal bones were dissected to determine the bone microenvironment in calvariae. Haematoxylin and eosin staining was used to determine the morphology of different calvarial bones under microscopy. TaqMan was used to analyse the relative expression of Runx2, OC, OSX, RANK, RANKL, OPG, N-cadherin, E-cadherin, FGF2 and FGFR1 genes in different parts of the calvariae. Histological analysis demonstrated different bone marrow (BM) areas between the different parts of the calvariae. The data show that parietal bones have the smallest BM area compared to frontal and interparietal bones. TaqMan data show a significant increase in the expression level of Runx2, OC, OSX, RANKL, OPG, FGF2 and FGFR1 genes in the parietal bones compared with the frontal and interparietal bones of calvariae. This study provides evidence that different calvarial bones, frontal, parietal and interparietal, contain different bone microenvironments.

  9. Prevention of enamel demineralization during orthodontic treatment: an in vitro comparative study.

    Science.gov (United States)

    Bichu, Yashodhan M; Kamat, Nandini; Chandra, Pavan Kumar; Kapoor, Aditi; Razmus, Thomas; Aravind, N K S

    2013-01-01

    Enamel demineralization is considered to be the most prevalent and significant iatrogenic effect associated with fixed orthodontic treatment and can seriously jeopardize both tooth longevity and dental esthetics. This in vitro study was undertaken to compare the effectiveness of four different commercially available surface treatment medicaments for the inhibition of enamel demineralization. Seventy-five intact maxillary premolars extracted from patients undergoing orthodontic treatment were divided into five equal groups and were subjected to one of the following protocols: no treatment (control group) or treatment with one of the following four medicaments: fluoride varnish (Fluor Protector [FP]), casein phosphopeptide-amorphous calcium phosphate (GC Tooth Mousse [TM]), calcium sodium phosphosilicate (SHY-NM), and casein phosphopeptide-amorphous calcium phosphate with fluoride (GC Tooth Mousse Plus [TMP]). All the teeth were subjected to ten Cate demineralization solution?for 96 hours and subsequently evaluated under polarized light microscopy to obtain the mean depths of enamel demineralization. One-way analysis of variance and Bonferroni comparison tests were used to obtain statistically significant differences between the five different groups at P < .05. All four surface treatment medicaments provided statistically significant reduction in the depths of enamel demineralization as compared with the control group. FP provided the greatest protection of enamel surface in terms of reduction of lesion depth, followed by TMP, SHY-NM, and TM. The use of these commercially available medicaments could prove to be beneficial for patients undergoing orthodontic treatment and who are at a risk for developing enamel decalcification.

  10. Effect of white tea and xylitol on structure and properties of demineralized enamel and jawbone

    Science.gov (United States)

    Auerkari, EI; Kiranahayu, R.; Emerita, D.; Sumariningsih, P.; Sarita, D.; Adiwirya, MS; Suhartono, AW

    2018-05-01

    White tea and xylitol have been suggested as potential agents to combat dental caries and osteoporosis through enhanced remineralization. This investigation aimed to determine the effects of exposure to white tea with and without xylitol on the structure, composition and hardness of demineralized human dental enamel. For control, samples of untreated and demineralized enamel and samples of untreated rat jawbone were subjected to similar measurements. For demineralization, the enamel samples were immersed for two days at 50°C in an acetate solution (pH 4.0). All samples were then soaked for two weeks at 37°C in a solution containing three different concentrations of white tea, xylitol or both, and an optional addition of the remineralization ingredients including Ca, P and F. For enamel samples without preceding demineralization and without added remineralization ingredients, the results showed highest mean hardness after immersion in a solution containing both white tea and xylitol, practically independently of their applied concentration level. However, for demineralized enamel samples with added remineralization ingredients, the resulting mean hardness was also dependent on concentration of white tea and xylitol. With sufficient concentration, hardness was again higher for combined white tea and xylitol than for either of these used alone.

  11. Radiographic and histological study of perennial bone defect repair in rat calvaria after treatment with blocks of porous bovine organic graft material.

    Science.gov (United States)

    Marins, Lucele Vieira; Cestari, Tania Mary; Sottovia, André Dotto; Granjeiro, José Mauro; Taga, Rumio

    2004-03-01

    Over the last few years, various bone graft materials of bovine origin to be used in oromaxillofacial surgeries have entered the market. In the present study, we determined the capacity of a block organic bone graft material (Gen-ox, Baumer SA, Brazil) prepared from bovine cancellous bone to promote the repair of critical size bone injuries in rat calvaria. A transosseous defect measuring approximately 8mm in diameter was performed with a surgical trephine in the parietal bone of 25 rats. In 15 animals, the defects were filled with a block of graft material measuring 8mm in diameter and soaked in the animal's own blood, and in the other 10 animals the defects were only filled with blood clots. The calvariae of rats receiving the material were collected 1, 3 and 6 months after surgery, and those of animals receiving the blood clots were collected immediately and 6 months after surgery. During surgery, the graft material was found to be of easy handling and to adapt perfectly to the receptor bed after soaking in blood. The results showed that, in most animals treated, the material was slowly resorbed and served as a space filling and maintenance material, favoring angiogenesis, cell migration and adhesion, and bone neoformation from the borders of the lesion. However, a foreign body-type granulomatous reaction, with the presence of numerous giant cells preventing local bone neoformation, was observed in two animals of the 1-month subgroup and in one animal of the 3-month subgroup. These cases were interpreted as resulting from the absence of demineralization and the lack of removal of potential antigen factors during production of the biomaterial. We conclude that, with improvement in the quality control of the material production, block organic bone matrix will become a good alternative for bone defect repair in the oromaxillofacial region due to its high osteoconductive capacity.

  12. Vibrational monitor of early demineralization in tooth enamel after in vitro exposure to phosphoridic liquid

    Science.gov (United States)

    Pezzotti, Giuseppe; Adachi, Tetsuya; Gasparutti, Isabella; Vincini, Giulio; Zhu, Wenliang; Boffelli, Marco; Rondinella, Alfredo; Marin, Elia; Ichioka, Hiroaki; Yamamoto, Toshiro; Marunaka, Yoshinori; Kanamura, Narisato

    2017-02-01

    The Raman spectroscopic method has been applied to quantitatively assess the in vitro degree of demineralization in healthy human teeth. Based on previous evaluations of Raman selection rules (empowered by an orientation distribution function (ODF) statistical algorithm) and on a newly proposed analysis of phonon density of states (PDOS) for selected vibrational modes of the hexagonal structure of hydroxyapatite, a molecular-scale evaluation of the demineralization process upon in vitro exposure to a highly acidic beverage (i.e., CocaCola™ Classic, pH = 2.5) could be obtained. The Raman method proved quite sensitive and spectroscopic features could be directly related to an increase in off-stoichiometry of the enamel surface structure since the very early stage of the demineralization process (i.e., when yet invisible to other conventional analytical techniques). The proposed Raman spectroscopic algorithm might possess some generality for caries risk assessment, allowing a prompt non-contact diagnostic practice in dentistry.

  13. Kinetic modelling of the demineralization of shrimp exoskeleton using citric acid

    Directory of Open Access Journals (Sweden)

    Alewo Opuada AMEH

    2014-11-01

    Full Text Available Citric acid was used in the demineralization of shrimp exoskeleton and the kinetics of the demineralization process was studied. Kinetic data was obtained by demineralisation using five acid concentrations (0.1, 0.2, 0.3, 0.4 and 0.5M. The obtained kinetic data were fitted to the shrinking core model for fluid particle reactions. The concentration of calcium was found to decrease with time. For all acid concentrations considered, the best predictive mechanism for the demineralization process was determined to be Ash Layer Diffusion Control Mechanism. This was indicated by the high R2 values obtained (0.965 with 150% excess of citric acid.

  14. Fourier Transformed Infra-Red Imaging of Femoral Neck Bone: Reduced Heterogeneity of Mineral-to-Matrix and Carbonate-to-Phosphate and more Variable Crystallinity in Treatment-Naïve Fracture Cases compared to Fracture-Free Controls

    Science.gov (United States)

    Gourion-Arsiquaud, Samuel; Lukashova, Lyudmilla; Power, Jon; Loveridge, Nigel; Reeve, Jonathan; Boskey, Adele L.

    2012-01-01

    After age 60 hip fracture risk strongly increases, but only a fifth of this increase is attributable to reduced mineral density (BMD, measured clinically). Changes in bone quality, specifically bone composition as measured by Fourier Transform Infrared spectroscopic imaging (FTIRI), also contribute to fracture risk. Here, FTIRI was applied to study the femoral neck and provide spatially derived information on its mineral and matrix properties in age-matched fractured and non-fractured bones. Whole femoral neck cross sections, divided into quadrants along the neck’s axis, from 10 women with hip fracture and 10 cadaveric controls were studied using FTIRI and micro-computed Tomography. Although 3-dimensional micro-CT bone mineral densities were similar, the mineral-to-matrix ratio was reduced in the cases of hip fracture, confirming previous reports. New findings were that the FTIRI microscopic variation (heterogeneity) of the mineral-to-matrix ratio was substantially reduced in the fracture group as was the heterogeneity of the carbonate-to-phosphate ratio. Conversely, the heterogeneity of crystallinity was increased. Increased variation of crystallinity was statistically associated with reduced variation of the carbonate-to-phosphate ratio. Anatomical variation in these properties between the different femoral neck quadrants was reduced in the fracture group compared to controls. While our treatment-naïve patients had reduced rather than increased bending resistance, these changes in heterogeneity associated with hip fracture are in another way comparable to the effects of experimental bisphosphonate therapy, which decreases heterogeneity and other indicators of bone’s toughness as a material. PMID:22865771

  15. [Bone homeostasis and Mechano biology.

    Science.gov (United States)

    Nakashima, Tomoki

    The weight-bearing exercises help to build bones and to maintain them strength. Bone is constantly renewed by the balanced action of osteoblastic bone formation and osteoclastic bone resorption both of which mainly occur at the bone surface. This restructuring process called "bone remodeling" is important not only for normal bone mass and strength, but also for mineral homeostasis. Bone remodeling is stringently regulated by communication between bone component cells such as osteoclasts, osteoblasts and osteocytes. An imbalance of this process is often linked to various bone diseases. During bone remodeling, resorption by osteoclasts precedes bone formation by osteoblasts. Based on the osteocyte location within the bone matrix and the cellular morphology, it is proposed that osteocytes potentially contribute to the regulation of bone remodeling in response to mechanical and endocrine stimuli.

  16. Demineralization–remineralization dynamics in teeth and bone

    Directory of Open Access Journals (Sweden)

    Abou Neel EA

    2016-09-01

    Full Text Available Ensanya Ali Abou Neel,1–3 Anas Aljabo,3 Adam Strange,3 Salwa Ibrahim,3 Melanie Coathup,4 Anne M Young,3 Laurent Bozec,3 Vivek Mudera4 1Division of Biomaterials, Operative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; 2Biomaterials Department, Faculty of Dentistry, Tanta University, Tanta, Egypt; 3Department of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, London, UK; 4UCL Institute of Orthopaedics and Musculoskeletal Sciences, Royal National Orthopaedic Hospital, Stanmore, London, UK Abstract: Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization–remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties

  17. Crystallization and demineralization phenomena in washed-rind cheese.

    Science.gov (United States)

    Tansman, Gil F; Kindstedt, Paul S; Hughes, John M

    2017-11-01

    This report documents an observational study of a high-moisture washed-rind cheese. Three batches of cheese were sampled on a weekly basis for 6 wk and again at wk 10. Center, under-rind, rind, and smear samples were tested for pH, moisture, and selected mineral elements. Powder x-ray diffractometry and petrographic microscopy were applied to identify and image the crystal phases. The pH of the rind increased by over 2 pH units by wk 10. The pH of the under-rind increased but remained below the rind pH, whereas the center pH decreased for most of aging and only began to rise after wk 5. Diffractograms of smear material revealed the presence of 4 crystal phases: brushite, calcite, ikaite, and struvite. The phases nucleated in succession over the course of aging, with calcite and ikaite appearing around the same time. A very small amount of brushite appeared sporadically in center and under-rind samples, but otherwise no other crystallization was observed beneath the rind. Micrographs revealed that crystals in the smear grew to over 250 μm in length by wk 10, and at least 2 different crystal phases, probably ikaite and struvite, could be differentiated by their different optical properties. The surface crystallization was accompanied by a mineral diffusion phenomenon that resulted, on average, in a 217, 95.7, and 149% increase in calcium, phosphorus, and magnesium, respectively, in the rind by wk 10. The diffusion phenomenon caused calcium, phosphorus, and magnesium to decrease, on average, by 55.0, 21.5, and 36.3%, respectively, in the center by wk 10. The present study represents the first observation of crystallization and demineralization phenomena in washed-rind cheese. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  18. Demineralization of Sargassum spp. Macroalgae Biomass: Selective Hydrothermal Liquefaction Process for Bio-Oil Production

    Energy Technology Data Exchange (ETDEWEB)

    Díaz-Vázquez, Liz M., E-mail: limdiaz@uprrp.edu; Rojas-Pérez, Arnulfo; Fuentes-Caraballo, Mariela; Robles, Isis V. [Department of Chemistry, University of Puerto Rico Río Piedras Campus, San Juan, PR (United States); Jena, Umakanta [Bioenergy Laboratory, Desert Research Institute, Reno, NV (United States); Das, K. C. [College of Engineering, University of Georgia, Athens, GA (United States)

    2015-02-11

    Algae biomasses are considered a viable option for the production of biofuel because of their high yields of oil produced per dry weight. Brown macroalgae Sargassum spp. are one of the most abundant species of algae in the shores of Puerto Rico. Its availability in large quantity presents a great opportunity for use as a source of renewable energy. However, high ash content of macroalgae affects the conversion processes and the quality of resulting fuel products. This research studied the effect of different demineralization treatments of Sargassum spp. biomass, subsequent hydrothermal liquefaction (HTL), and bio-oil characterization. Demineralization constituted five different treatments: nanopure water, nitric acid, citric acid, sulfuric acid, and acetic acid. Performance of demineralization was evaluated by analyzing both demineralized biomass and HTL products by the following analyses: total carbohydrates, proteins, lipids, ash content, caloric content, metals analysis, Fourier transform infrared-attenuated total reflectance spectroscopy, energy dispersive spectroscopy, scanning electron microscopy, and GCMS analysis. HTL of Sargassum spp. before and after citric acid treatment was performed in a 1.8 L batch reactor system at 350°C with a holding time of 60 min and high pressures (5–21 MPa). Demineralization treatment with nitric acid was found the most effective in reducing the ash content of the macroalgae biomass from 27.46 to 0.99% followed by citric acid treatment that could reduce the ash content to 7%. Citric acid did not show significant leaching of organic components such as carbohydrates and proteins, and represented a less toxic and hazardous option for demineralization. HTL of untreated and citric acid treated Sargassum spp. resulted in bio-oil yields of 18.4 ± 0.1 and 22.2 ± 0.1% (ash-free dry basis), respectively.

  19. Fluoride releasing and enamel demineralization around orthodontic brackets by fluoride-releasing composite containing nanoparticles.

    Science.gov (United States)

    Melo, Mary A S; Morais, Weslanny A; Passos, Vanara F; Lima, Juliana P M; Rodrigues, Lidiany K A

    2014-05-01

    Fluoride-containing materials have been suggested to control enamel demineralization around orthodontic brackets during the treatment with fixed appliances. The improvement of their properties has been made through innovations, such as the application of nanotechnology by incorporation of nanofillers. This in vitro study evaluated the capacity of fluoride releasing and enamel demineralization inhibition of fluoride-releasing nanofilled cement around orthodontic brackets using an artificial caries biofilm model. Forty bovine enamel discs were selected by evaluating surface microhardness and randomized into four groups (n = 10): non-fluoride-releasing microfilled composite, fluoride-releasing microfilled composite, resin-modified glass ionomer cement (RMGI), and fluoride-releasing nanofilled composite (FN). After brackets bonding in each disc, the specimens were subjected to a cariogenic challenge through a Streptococcus mutans biofilm model. After the experimental period, the biofilm formed around the brackets was collected for fluoride analysis and the mineral loss around the brackets was determined by integrated demineralization via cross-sectional microhardness measurement at 20 and 70 μm from the bracket margin. Additionally, samples of each group were subjected to energy-dispersive X-ray spectroscopy (EDX) analysis examined under a scanning electron microscopy (SEM). ANOVA followed by Tukey test were applied for fluoride concentration and mineral loss data, respectively. At both distances, only RMGI statistically differed from the other groups presenting the lowest demineralization, although there was a trend to a lower demineralization of enamel around brackets in FN group. Similar condition was found to fluoride concentration and EDX/SEM analysis. Under the cariogenic exposure condition of this study, the fluoride-releasing nanofilled material had similar performance to fluoride-releasing microfilled materials. The presence of nanofillers in the fluoride

  20. Acid demineralization susceptibility of dental enamel submitted to different bleaching techniques and fluoridation regimens.

    Science.gov (United States)

    Salomão, Dlf; Santos, Dm; Nogueira, Rd; Palma-Dibb, Rg; Geraldo-Martins, Vr

    2014-01-01

    The aim of the current study was to assess the acid demineralization susceptibility of bleached dental enamel submitted to different fluoride regimens. One hundred bovine enamel blocks (6×6×3 mm) were randomly divided into 10 groups (n=10). Groups 1 and 2 received no bleaching. Groups 3 to 6 were submitted to an at-home bleaching technique using 6% hydrogen peroxide (HP; G3 and G4) or 10% carbamide peroxide (CP; G5 and G6). Groups 7 to 10 were submitted to an in-office bleaching technique using 35% HP (G7 and G8) or 35% CP (G9 and G10). During bleaching, a daily fluoridation regimen of 0.05% sodium fluoride (NaF) solution was performed on groups 3, 5, 7, and 9, while weekly fluoridation with a 2% NaF gel was performed on groups 4, 6, 8, and 10. The samples in groups 2 to 10 were pH cycled for 14 consecutive days. The samples from all groups were then assessed by cross-sectional Knoop microhardness at different depths from the outer enamel surface. The average Knoop hardness numbers (KHNs) were compared using one-way analysis of variance and Tukey tests (α=0.05). The comparison between groups 1 and 2 showed that the demineralization method was effective. The comparison among groups 2 to 6 showed the same susceptibility to acid demineralization, regardless of the fluoridation method used. However, the samples from groups 8 and 10 showed more susceptibility to acid demineralization when compared with group 2 (penamel to acid demineralization. However, the use of 35% HP and 35% CP must be associated with a daily fluoridation regimen, otherwise the in-office bleaching makes the bleached enamel more susceptible to acid demineralization.

  1. Demineralization of Sargassum spp. Macroalgae Biomass: Selective Hydrothermal Liquefaction Process for Bio-Oil Production

    International Nuclear Information System (INIS)

    Díaz-Vázquez, Liz M.; Rojas-Pérez, Arnulfo; Fuentes-Caraballo, Mariela; Robles, Isis V.; Jena, Umakanta; Das, K. C.

    2015-01-01

    Algae biomasses are considered a viable option for the production of biofuel because of their high yields of oil produced per dry weight. Brown macroalgae Sargassum spp. are one of the most abundant species of algae in the shores of Puerto Rico. Its availability in large quantity presents a great opportunity for use as a source of renewable energy. However, high ash content of macroalgae affects the conversion processes and the quality of resulting fuel products. This research studied the effect of different demineralization treatments of Sargassum spp. biomass, subsequent hydrothermal liquefaction (HTL), and bio-oil characterization. Demineralization constituted five different treatments: nanopure water, nitric acid, citric acid, sulfuric acid, and acetic acid. Performance of demineralization was evaluated by analyzing both demineralized biomass and HTL products by the following analyses: total carbohydrates, proteins, lipids, ash content, caloric content, metals analysis, Fourier transform infrared-attenuated total reflectance spectroscopy, energy dispersive spectroscopy, scanning electron microscopy, and GCMS analysis. HTL of Sargassum spp. before and after citric acid treatment was performed in a 1.8 L batch reactor system at 350°C with a holding time of 60 min and high pressures (5–21 MPa). Demineralization treatment with nitric acid was found the most effective in reducing the ash content of the macroalgae biomass from 27.46 to 0.99% followed by citric acid treatment that could reduce the ash content to 7%. Citric acid did not show significant leaching of organic components such as carbohydrates and proteins, and represented a less toxic and hazardous option for demineralization. HTL of untreated and citric acid treated Sargassum spp. resulted in bio-oil yields of 18.4 ± 0.1 and 22.2 ± 0.1% (ash-free dry basis), respectively.

  2. Demineralization of Sargassum spp. macroalgae biomass: selective hydrothermal liquefaction process for bio-oil production

    Directory of Open Access Journals (Sweden)

    Liz M Díaz-Vázquez

    2015-02-01

    Full Text Available Algae biomasses are considered a viable option for the production of biofuel because of their high yields of oil produced per dry weight. Brown macroalgae Sargassum spp. are one of the most abundant species of algae in the shores of Puerto Rico. Its availability in large quantity presents a great opportunity for use as a source of renewable energy. However, high ash content of macroalgae affects the conversion processes and the quality of resulting fuel products. This research studied the effect of different demineralization treatments of Sargassum spp. biomass, subsequent hydrothermal liquefaction (HTL and bio-oil characterization. Demineralization constituted five different treatments: nanopure water, nitric acid, citric acid, sulfuric acid, and acetic acid. Performance of demineralization was evaluated by analyzing both demineralized biomass and HTL products by the following analyses: total carbohydrates, proteins, lipids, ash content, caloric content, metals analysis, Fourier Transform Infrared - Attenuated Total Reflectance (FTIR-ATR Spectroscopy, Energy Dispersive Spectroscopy (EDS, Scanning Electron Microscopy (SEM, and GCMS analysis. HTL of Sargassum spp. before and after citric acid treatment, was performed in a 1.8 L batch reactor system at 350°C with a holding time of 60 min and high pressures (5-21 MPa. Demineralization treatment with nitric acid was found the most effective in reducing the ash content of the macroalgae biomass from 27.46% to 0.99% followed by citric acid treatment that could reduce the ash content to 7%. Citric acid did not show significant leaching of organic components such as carbohydrates and proteins, and represented a less toxic and hazardous option for demineralization. HTL of untreated and citric acid treated Sargassum spp. resulted in bio-oil yields of 18.4±0.1 % and 22.2±0.1 % (ash free dry basis, respectively.

  3. Acellular dermal matrix loading with bFGF achieves similar acceleration of bone regeneration to BMP-2 via differential effects on recruitment, proliferation and sustained osteodifferentiation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Du, Mi; Zhu, Ting; Duan, Xiaoqi; Ge, Shaohua; Li, Ning; Sun, Qinfeng; Yang, Pishan

    2017-01-01

    New generation of barrier membranes has been developed, which not only act as barriers but also as delivery devices to release specific growth factors. This study observed biological behaviors of bone morrow mesenchymal stem cells (BMMSCs) pretreated by bFGF or BMP-2 in vitro and evaluated differential bone regeneration process induced by bFGF and BMP-2 loaded acellular dermal matrix (ADM) membrane using critical-size rat calvarial defect model in vivo. The results showed that the proliferation capability of BMMSCs pretreated by bFGF was stronger than that by BMP-2, while there was temporally differential effect of bFGF and BMP-2 pretreatment on MSC osteogenic differentiation potentials. During healing process of rat calvarial defects, 2-fold more CD34 −/CD90 + MSCs in group of bFGF-ADM was observed than in any other treatment group at 2 weeks. However, there were similar amount of new bone formation and expression of osteopotin in newly-formed bone tissue in groups of bFGF- and BMP-2-ADM at 8 weeks, which were more than those in ADM alone and blank control. Taken together, bFGF-ADM guided similar bone regeneration to BMP-2 through more efficient recruitment of MSCs, and moreover, BMMSCs pretreated by bFGF showed stronger proliferation at 1–5 days and osteogenic differentiation potentials at 14 days compared with BMP-2 pretreatment. - Highlights: • An improved barrier membrane used in the field of bone tissue engineering was proposed, which is acellular dermal matrix (ADM) loaded with growth factors. • It is generally agreed that BMP-2 and -7 provide the greatest bone regeneration potentials, however, we found that ADM loading with bFGF could guide similar bone regeneration to BMP-2. • Compared with BMP-2, bFGF could more effectively recruit MSCs and moreover, BMMSCs pretreated by bFGF showed out stronger proliferation at 1-5 days and osteogenic differentiation potentials at 14 days.

  4. Comparison of histomorphometry and 85Sr uptake in induced heterotopic bone in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G

    1992-01-01

    Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by implantation of 5, 10, or 15 mg demineralized bone (DBM) powder was evaluated at 4 weeks by 85Sr uptake of the implants and area histomorphometry of the induced bone. Two indices of 85Sr uptake were...... with increasing mass of implanted DBM, whereas the osteogenic index did not change....

  5. Changes in composition and enamel demineralization inhibition activities of gallic acid at different pH values

    NARCIS (Netherlands)

    Zhang, J.; Huang, X.; Huang, S.; Deng, M.; Xie, X.; Liu, M.; Liu, H.; Zhou, X.; Li, J.; ten Cate, J.M.

    2015-01-01

    Background. Gallic acid (GA) has been shown to inhibit demineralization and enhance remineralization of enamel; however, GA solution is highly acidic. This study was to investigate the stability of GA solutions at various pH and to examine the resultant effects on enamel demineralization. Methods.

  6. Isolation of mouse mesenchymal stem cells with normal ploidy from bone marrows by reducing oxidative stress in combination with extracellular matrix

    Directory of Open Access Journals (Sweden)

    Wang Fang

    2011-07-01

    Full Text Available Abstract Background Isolation of mouse MSCs (mMSCs with normal ploidy from bone marrow remains challenging. mMSCs isolated under 20% O2 are frequently contaminated by overgrown hematopoietic cells, and could also be especially vulnerable to oxidative damage, resulting in chromosomal instability. Culture under low oxygen or extracellular matrix (ECM improves proliferation of MSCs in several species. We tested the hypothesis that culture under low oxygen in combination with ECM prepared from mouse embryonic fibroblast (MEF-ECM could be used to purify proliferative mMSCs, and to reduce oxidative damage and maintain their chromosomal stability. Results Optimization of culture conditions under 20% O2 resulted in immortalization of mMSCs, showing extensive chromosome abnormalities, consistent with previous studies. In contrast, culture under low oxygen (2% O2 improved proliferation of mMSCs and reduced oxidative damage, such that mMSCs were purified simply by plating at low density under 2% O2. MEF-ECM reduced oxidative damage and enhanced proliferation of mMSCs. However, these isolated mMSCs still exhibited high frequency of chromosome abnormalities, suggesting that low oxygen or in combination with MEF-ECM was insufficient to fully protect mMSCs from oxidative damage. Notably, antioxidants (alpha -phenyl-t-butyl nitrone (PBN and N-acetylcysteine (NAC further reduced DNA damage and chromosomal abnormalities, and increased proliferation of mMSCs. mMSCs isolated by the combination method were successfully used to generate induced pluripotent stem (iPS cells by ectopic expression of Oct4, Sox2, Klf4 and c-Myc. Conclusions We have developed a technique that allows to reduce the number of karyotypic abnormalities for isolation of primary mMSCs and for limited culture period by combination of low oxygen, MEF-ECM, antioxidants and low density plating strategy. The effectiveness of the new combination method is demonstrated by successful generation of i

  7. The Expression of Bone Morphogenetic Protein 2 and Matrix Metalloproteinase 2 through Retinoic Acid Receptor Beta Induced by All-Trans Retinoic Acid in Cultured ARPE-19 Cells.

    Directory of Open Access Journals (Sweden)

    Zhenya Gao

    Full Text Available All-trans retinoic acid (ATRA plays an important role in ocular development. Previous studies found that retinoic acid could influence the metabolism of scleral remodeling by promoting retinal pigment epithelium (RPE cells to secrete secondary signaling factors. The purpose of this study was to investigate whether retinoic acid affected secretion of bone morphogenetic protein 2 (BMP-2 and matrix metalloproteinase 2 (MMP-2 and to explore the signaling pathway of retinoic acid in cultured acute retinal pigment epithelial 19 (ARPE-19 cells.The effects of ATRA (concentrations from 10-9 to 10-5 mol/l on the expression of retinoic acid receptors (RARs in ARPE-19 cells were examined at the mRNA and protein levels using reverse transcription-polymerase chain reaction (RT-PCR and western blot assay, respectively. The effects of treating ARPE-19 cells with ATRA concentrations ranging from 10-9 to 10-5 mol/l for 24 h and 48 h or with 10-6mol/l ATRA at different times ranging from 6h to 72h were assessed using real-time quantitative PCR (qPCR and enzyme-linked immunosorbent assay (ELISA. The contribution of RARβ-induced activation of ARPE-19 cells was confirmed using LE135, an antagonist of RARβ.RARβ mRNA levels significantly increased in the ARPE-19 cells treated with ATRA for 24h and 48h. These increases in RARβ mRNA levels were dose dependent (at concentrations of 10-9 to 10-5 mol/l with a maximum effect observed at 10-6 mol/l. There were no significant changes in the mRNA levels of RARα and RARγ. Western blot assay revealed that RARβ protein levels were increased significantly in a time-dependent manner in ARPE-19 cells treated with 10-6 mol/l ATRA from 12 h to 72 h, with a marked increase observed at 24 h and 48 h. The upregulation of RARβ and the ATRA-induced secretion in ARPE-19 cells could be inhibited by the RARβ antagonist LE135.ATRA induced upregulation of RARβ in ARPE-19 cells and stimulated these cells to secrete BMP-2 and MMP-2.

  8. Increased serum and bone matrix levels of transforming growth factor {beta}1 in patients with GH deficiency in response to GH treatment

    DEFF Research Database (Denmark)

    Ueland, Thor; Lekva, Tove; Otterdal, Kari

    2011-01-01

    Patients with adult onset GH deficiency (aoGHD) have secondary osteoporosis, which is reversed by long-term GH substitution. Transforming growth factor β1 (TGFβ1 or TGFB1) is abundant in bone tissue and could mediate some effects of GH/IGFs on bone. We investigated its regulation by GH/IGF1 in vivo...

  9. Efficacy of rhBMP-2 Loaded PCL/β-TCP/bdECM Scaffold Fabricated by 3D Printing Technology on Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Eun-Bin Bae

    2018-01-01

    Full Text Available This study was undertaken to evaluate the effect of 3D printed polycaprolactone (PCL/β-tricalcium phosphate (β-TCP scaffold containing bone demineralized and decellularized extracellular matrix (bdECM and human recombinant bone morphogenetic protein-2 (rhBMP-2 on bone regeneration. Scaffolds were divided into PCL/β-TCP, PCL/β-TCP/bdECM, and PCL/β-TCP/bdECM/BMP groups. In vitro release kinetics of rhBMP-2 were determined with respect to cell proliferation and osteogenic differentiation. These three reconstructive materials were implanted into 8 mm diameter calvarial bone defect in male Sprague-Dawley rats. Animals were sacrificed four weeks after implantation for micro-CT, histologic, and histomorphometric analyses. The findings obtained were used to calculate new bone volumes (mm3 and new bone areas (%. Excellent cell bioactivity was observed in the PCL/β-TCP/bdECM and PCL/β-TCP/bdECM/BMP groups, and new bone volume and area were significantly higher in the PCL/β-TCP/bdECM/BMP group than in the other groups (p<.05. Within the limitations of this study, bdECM printed PCL/β-TCP scaffolds can reproduce microenvironment for cells and promote adhering and proliferating the cells onto scaffolds. Furthermore, in the rat calvarial defect model, the scaffold which printed rhBMP-2 loaded bdECM stably carries rhBMP-2 and enhances bone regeneration confirming the possibility of bdECM as rhBMP-2 carrier.

  10. Successful treatment of unicameral bone cyst by single percutaneous injection of alpha-BSM.

    Science.gov (United States)

    Thawrani, Dinesh; Thai, Chia Che; Welch, Robert D; Copley, Lawson; Johnston, Charles E

    2009-01-01

    Unicameral bone cyst (UBC) is a benign bone lesion, recognized for its high rate of recurrence and need for repeat procedures to achieve healing. We hypothesized that the osteoconductive material apatitic calcium phosphate (alpha-BSM) could be effective in filling and stimulating resolution of UBC. The purpose of this study was to evaluate clinical and radiographic outcomes of UBC treated by a single injection of alpha-BSM. Thirteen patients (6 male, 7 female) with a mean age of 10.5 years, underwent single percutaneous injection of alpha-BSM for presumed UBC. The aspiration of the cysts was followed by vigorous saline lavage using 2 wide bore needles to disrupt the cyst walls. alpha-BSM "paste" was then injected under fluoroscopic guidance. Radiographs were digitized to measure cystic area (millimeter squares) on 2 orthogonal views. Healing was rated according to a modified Neer outcome grading system. Nine of the 13 patients had had pathologic fractures in the past. Eleven of the 13 patients had had past unsuccessful treatment: multiple steroid injections in 6, curettage and bone grafting in 3, and bone marrow and demineralized bone matrix (Grafton) injection in 2. Five cysts were grade 1 (healed 100%), 6 grade 2 (healed >50%), 2 grade 3 (healed <50% with increased cortical thickness), and none grade 4 (recurrence/enlargement). The average resolution of cystic area in 11/13 cysts was 85.7% at final follow-up of 35.8 months (P=0.0001) with 2.8 mm of average gain in cortical thickness (P=0.0018). None of the 13 lesions required an additional procedure or repeat injection. All patients were clinically asymptomatic at latest follow-up. This is the first study quantifying cyst resolution objectively according to actual decrease in area (millimeter squares). A single injection of alpha-BSM is a safe, minimally invasive and efficacious method to treat UBC in the pediatric population.

  11. The changes of bone mineralization after parathyroidectomy in primary hyperparathyroidism. Case report

    International Nuclear Information System (INIS)

    Przedlacki, J.; Nawrot, I.; Chudzinski, W.

    1995-01-01

    The aim of the study was to evaluate the changes of bone demineralization in the patient after parathyroidectomy in primary hyperparathyroidism. Bone mineralization was evaluated by Lunar DPX-L equipment in lumbar spine, femoral neck, radius and total skeleton area in 3 months intervals during 18 months period. Because of transient after surgical hypocalcemia she has received active metabolite of vitamin D - Alfacalcidolum during one year. After removal of parathyroid adenoma there was disappearance of clinical and biochemical signs of primary hyperparathyroidism. At the same time there was total normalization of bone mineral density in lumbar spine, femoral neck, ultradistal site of radius and total area. There was partial normalization of bone mineralization in radius shaft. The surgery of adenoma in primary hyperparathyroidism with transient treatment with active metabolite of vitamin D is successful therapy of bone demineralization in this disease. (author). 5 refs, 2 figs

  12. Fouling control mechanisms of demineralized water backwash: Reduction of charge screening and calcium bridging effects

    KAUST Repository

    Li, Sheng

    2011-12-01

    This paper investigates the impact of the ionic environment on the charge of colloidal natural organic matter (NOM) and ultrafiltration (UF) membranes (charge screening effect) and the calcium adsorption/bridging on new and fouled membranes (calcium bridging effect) by measuring the zeta potentials of membranes and colloidal NOM. Fouling experiments were conducted with natural water to determine whether the reduction of the charge screening effect and/or calcium bridging effect by backwashing with demineralized water can explain the observed reduction in fouling. Results show that the charge of both membranes and NOM, as measured by the zeta potential, became more negative at a lower pH and a lower concentration of electrolytes, in particular, divalent electrolytes. In addition, calcium also adsorbed onto the membranes, and consequently bridged colloidal NOM and membranes via binding with functional groups. The charge screening effect could be eliminated by flushing NOM and membranes with demineralized water, since a cation-free environment was established. However, only a limited amount of the calcium bridging connection was removed with demineralized water backwashes, so the calcium bridging effect mostly could not be eliminated. As demineralized water backwash was found to be effective in fouling control, it can be concluded that the reduction of the charge screening is the dominant mechanism for this. © 2011 Elsevier Ltd.

  13. Fouling control mechanisms of demineralized water backwash: Reduction of charge screening and calcium bridging effects

    KAUST Repository

    Li, Sheng; Heijman, Bas G J; Verberk, J. Q J C; Le-Clech, Pierre; Lu, Jie; Kemperman, Antoine J B; Amy, Gary L.; Van Dijk, Johannis C.

    2011-01-01

    with demineralized water can explain the observed reduction in fouling. Results show that the charge of both membranes and NOM, as measured by the zeta potential, became more negative at a lower pH and a lower concentration of electrolytes, in particular, divalent

  14. Effects of honey, glucose, and fructose on the enamel demineralization depth

    Directory of Open Access Journals (Sweden)

    Fatemeh Ahmadi-Motamayel

    2013-06-01

    Conclusion: The results of this study demonstrated that honey had less caries activity than the other sugars. However, further evidence is required to detect the active components and mechanisms by which it reduces demineralization and to demonstrate whether this food has any clinical application for preventing and reducing dental caries.

  15. Microhardness of demineralized enamel following home bleaching and laser-assisted in office bleaching

    Science.gov (United States)

    Ghanbarzadeh, Majid; Akbari, Majid; Hamzei, Haniye

    2015-01-01

    Background There is little data regarding the effect of tooth whitening on microhardness of white spot lesions. This study was conducted to investigate the effect of home-bleaching and laser-assisted in-office bleaching on microhardness of demineralized enamel. Material and Methods Forty bovine incisors were selected and immersed in a demineralizing solution for 12 weeks to induce white spot lesions. Enamel blocks were prepared and randomly assigned to two groups of 20 each. The first group underwent home bleaching with 15% carbamide peroxide which was applied for 8 hours a day over a period of 15 days. In the second group, in-office bleaching was performed by 40% hydrogen peroxide and powered by irradiation from an 810 nm gallium-aluminum-arsenide (GaAlAs) diode laser (CW, 2W). This process was performed for 3 sessions every seven days, in 15 days. The specimens were stored in Fusayama Meyer artificial saliva during the experiment. Surface microhardness was assessed before and after the bleaching therapies in both groups. Results Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (pTooth whitening through home bleaching or laser-assisted in-office bleaching can result in a significant reduction in microhardness of white spot lesions. Therefore, it is suggested to take protective measures on bleached demineralized enamel. Key words:White spot lesion, bleaching, laser, microhardness, demineralized enamel, home bleaching, in-office bleaching. PMID:26330939

  16. Comparison Study of Water Demineralization System for the OPR 1000 and AP 1000 Nuclear Power Plant

    International Nuclear Information System (INIS)

    Dedy Priambodo; Siti Alimah; Erlan Dewita

    2009-01-01

    OPR 1000 adopts demineralization method based on ion exchanger resin and AP 1000 adopt the method that based on Reverse Osmosis (RO)-Electrodeionization (EDI). The Ion exchange process is a reversible chemical reaction of a solution and an insoluble solid. Ion exchanger use resin as polluter ions capture and will be regenerated after its saturated. RO is method using pressure to force a solution through a membrane, retaining the solute on one side and allowing the pure solvent to pass to the other side. Whereas, EDI is a combination of ion exchange and electrodialysis. The ions is taken by ion exchange resin, and then it is discharged utilizing electric potential difference. Due to water splitting phenomena in EDI, make resin will never be saturated, so the RO-EDI process is water demineralization system that use little chemical, more simple installation, capable to maintain demineralization water product quality and environmental friendly. Thereby, The RO-EDI water demineralization system is more advance then ion exchange technology. (author)

  17. Strategies to eradicate minimal residual disease in small cell lung cancer: high-dose chemotherapy with autologous bone marrow transplantation, matrix metalloproteinase inhibitors, and BEC2 plus BCG vaccination.

    Science.gov (United States)

    Krug, L M; Grant, S C; Miller, V A; Ng, K K; Kris, M G

    1999-10-01

    In the last 25 years, treatment for small cell lung cancer (SCLC) has improved with advances in chemotherapy and radiotherapy. Standard chemotherapy regimens can yield 80% to 90% response rates and some cures when combined with thoracic irradiation in limited-stage patients. Nonetheless, small cell lung cancer has a high relapse rate due to drug resistance; this has resulted in poor survival for most patients. Attacking this problem requires a unique approach to eliminate resistant disease remaining after induction therapy. This review will focus on three potential strategies: high-dose chemotherapy with autologous bone marrow transplantation, matrix metalloproteinase inhibitors, and BEC2 plus BCG vaccination.

  18. Clinical evaluation of an allogeneic bone matrix containing viable osteogenic cells in patients undergoing one- and two-level posterolateral lumbar arthrodesis with decompressive laminectomy.

    Science.gov (United States)

    Musante, David B; Firtha, Michael E; Atkinson, Brent L; Hahn, Rebekah; Ryaby, James T; Linovitz, Raymond J

    2016-05-27

    Trinity Evolution® cellular bone allograft (TE) possesses the osteogenic, osteoinductive, and osteoconductive elements essential for bone healing. The purpose of this study is to evaluate the radiographic and clinical outcomes when TE is used as a graft extender in combination with locally derived bone in one- and two-level instrumented lumbar posterolateral arthrodeses. In this retrospective evaluation, a consecutive series of subject charts that had posterolateral arthrodesis with TE and a 12-month radiographic follow-up were evaluated. All subjects were diagnosed with degenerative disc disease, radiculopathy, stenosis, and decreased disc height. At 2 weeks and at 3 and 12 months, plain radiographs were performed and the subject's back and leg pain (VAS) was recorded. An evaluation of fusion status was performed at 12 months. The population consisted of 43 subjects and 47 arthrodeses. At 12 months, a fusion rate of 90.7 % of subjects and 89.4 % of surgical levels was observed. High-risk subjects (e.g., diabetes, tobacco use, etc.) had fusion rates comparable to normal patients. Compared with the preoperative leg or back pain level, the postoperative pain levels were significantly (p < 0.0001) improved at every time point. There were no adverse events attributable to TE. Fusion rates using TE were higher than or comparable to fusion rates with autologous iliac crest bone graft that have been reported in the recent literature for posterolateral fusion procedures, and TE fusion rates were not adversely affected by several high-risk patient factors. The positive results provide confidence that TE can safely replace autologous iliac crest bone graft when used as a bone graft extender in combination with locally derived bone in the setting of posterolateral lumbar arthrodesis in patients with or without risk factors for compromised bone healing. Because of the retrospective nature of this study, the trial was not registered.

  19. The hardness and chemical changes in demineralized primary dentin treated by fluoride and glass ionomer cement

    Directory of Open Access Journals (Sweden)

    Gisele Fernandes DIAS

    Full Text Available Abstract Background Fluoride plays an important role in the control of dental caries. Aim To evaluate the chemical exchange between restoration of glass ionomer cement of high viscosity (GIC and primary dentin with application of sodium fluoride (NaF 2% through changes in hardness from uptake of calcium, phosphate and fluoride. Material and method Class I cavities were prepared in 40 sound primary molars, and the sample was divided into two groups (n=20 according to dentin condition: sound (1 and demineralized (2. Sub-groups (n=10 were formed to investigate the isolated action of the GIC or the association with NaF (F. This in vitro study examined the chemical exchange under two conditions, sound and demineralized dentin (pH cycling, to simulate the occurrence of mineral loss for the caries lesion. G1 and G2 received GIC restoration only; groups G1F and G2F received NaF before GIC restoration. The specimens were prepared for Knoop hardness test and micro-Raman spectroscopy. A two-way ANOVA test (α = 0.05 was used for statistical analysis. Micro-Raman data were qualitatively described. Result Increased hardness was observed in all the sites of direct contact with GIC in sound and demineralized dentin for all groups (p0.05. In the evaluation of micro-Raman, direct contact between GIC and dentin for sound and demineralized dentin resulted in increased peaks of phosphate. Conclusion The exchange between GIC and demineralized dentin may induce changes of mechanical properties of the substrate, and uptake of mineral ions (phosphate occurs without the influence of NaF.

  20. In vitro study of the diode laser effect on artificial demineralized surface of human dental enamel

    International Nuclear Information System (INIS)

    Ebel, Patricia

    2003-01-01

    In scientific literature there are many reports about fusion and resolidification of dental enamel after laser irradiation and their capability to generate surfaces with increased resistance to demineralization compared to non-irradiated areas. The use of high power diode laser on demineralized surfaces of human dental enamel is presented as a good alternative in caries prevention. The purpose of this study is to investigate the morphological changes produced by the use of one high power diode laser on human dental enamel surface after demineralization treatment with lactic acid, under chosen parameters. Fifteen samples of human dental molars were used and divided in four groups: control - demineralization treatment with lactic acid and no irradiation, and demineralization treatment with lactic acid followed of irradiation with 212,20 mJ/cm 2 , 282,84 mJ/cm 2 and 325,38 mJ/cm 2 , respectively. The samples were irradiated with high power diode laser (808 nm) with a 300 μm diameter fiber optics. Black ink was used on enamel surface to enhance the superficial absorption. The samples were studied by optical microscopy and scanning electron microscopy. Modifications on the enamel surfaces were observed. Such modifications were characterized by melted and re-solidified region of the enamel. According with our results the best parameter was 2.0 W, presenting the most uniform surface. The use of high power diode laser as demonstrated in this study is able to promote melting and re-solidification on human dental enamel. (author)

  1. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  2. Solution exchange corrosion testing with the glass-zeolite ceramic waste form in demineralized water at 900C

    International Nuclear Information System (INIS)

    Simpson, L. J.

    1998-01-01

    A ceramic waste form of glass-bonded zeolite is being developed for the long-term disposition of fission products and transuranic elements in wastes from the U.S. Department of Energy's spent nuclear fuel conditioning activities. Solution exchange corrosion tests were performed on the ceramic waste form and its potential base constituents of glass, zeolite 5A, and sodalite as part of an effort to qualify the ceramic waste form for acceptance into the Civilian Radioactive Waste Management System. Solution exchange tests were performed at 90 C by replacing 80 to 90% of the leachate with fresh demineralized water after set time intervals. The results from these tests provide information about corrosion mechanisms and the ability of the ceramic waste form and its constituent materials to retain waste components. The results from solution exchange tests indicate that radionuclides will be preferentially retained in the zeolites without the glass matrix and in the ceramic waste form, with respect to cations like Li, K, and Na. Release results have been compared for simulated waste from candidate ceramic waste forms with zeolite 5A and its constituent materials to determine the corrosion behavior of each component

  3. Oriented and Ordered Biomimetic Remineralization of the Surface of Demineralized Dental Enamel Using HAP@ACP Nanoparticles Guided by Glycine

    Science.gov (United States)

    Wang, Haorong; Xiao, Zuohui; Yang, Jie; Lu, Danyang; Kishen, Anil; Li, Yanqiu; Chen, Zhen; Que, Kehua; Zhang, Qian; Deng, Xuliang; Yang, Xiaoping; Cai, Qing; Chen, Ning; Cong, Changhong; Guan, Binbin; Li, Ting; Zhang, Xu

    2017-01-01

    Achieving oriented and ordered remineralization on the surface of demineralized dental enamel, thereby restoring the satisfactory mechanical properties approaching those of sound enamel, is still a challenge for dentists. To mimic the natural biomineralization approach for enamel remineralization, the biological process of enamel development proteins, such as amelogenin, was simulated in this study. In this work, carboxymethyl chitosan (CMC) conjugated with alendronate (ALN) was applied to stabilize amorphous calcium phosphate (ACP) to form CMC/ACP nanoparticles. Sodium hypochlorite (NaClO) functioned as the protease which decompose amelogenin in vivo to degrade the CMC-ALN matrix and generate HAP@ACP core-shell nanoparticles. Finally, when guided by 10 mM glycine (Gly), HAP@ACP nanoparticles can arrange orderly and subsequently transform from an amorphous phase to well-ordered rod-like apatite crystals to achieve oriented and ordered biomimetic remineralization on acid-etched enamel surfaces. This biomimetic remineralization process is achieved through the oriented attachment (OA) of nanoparticles based on non-classical crystallization theory. These results indicate that finding and developing analogues of natural proteins such as amelogenin involved in the biomineralization by natural macromolecular polymers and imitating the process of biomineralization would be an effective strategy for enamel remineralization. Furthermore, this method represents a promising method for the management of early caries in minimal invasive dentistry (MID).

  4. Near-surface structural examination of human tooth enamel subject to in vitro demineralization and remineralization

    Science.gov (United States)

    Gaines, Carmen Veronica

    The early stages of chemical tooth decay are governed by dynamic processes of demineralization and remineralization of dental enamel that initiates along the surface of the tooth. Conventional diagnostic techniques lack the spatial resolution required to analyze near-surface structural changes in enamel at the submicron level. In this study, slabs of highly-polished, decay-free human enamel were subjected to 0.12M EDTA and buffered lactic acid demineralizing agents and MI Paste(TM) and calcifying (0.1 ppm F) remineralizing treatments in vitro. Grazing incidence x-ray diffraction (GIXD), a technique typically used for thin film analysis, provided depth profiles of crystallinity changes in surface enamel with a resolution better than 100 nm. In conjunction with nanoindentation, a technique gaining acceptance as a means of examining the mechanical properties of sound enamel, these results were corroborated with well-established microscopy and Raman techniques to assess the nanohardness, morphologies and chemical nature of treated enamel. Interestingly, the average crystallite size of surface enamel along its c-axis dimension increased by nearly 40% after a 60 min EDTA treatment as detected by GIXD. This result was in direct contrast to the obvious surface degradation observed by microscopic and confocal Raman imaging. A decrease in nanohardness from 4.86 +/- 0.44 GPa to 0.28 +/- 0.10 GPa was observed. Collective results suggest that mineral dissolution characteristics evident on the micron scale may not be fully translated to the nanoscale in assessing the integrity of chemically-modified tooth enamel. While an intuitive decrease in enamel crystallinity was observed with buffered lactic acid-treated samples, demineralization was too slow to adequately quantify the enamel property changes seen. MI Paste(TM) treatment of EDTA-demineralized enamel showed preferential growth along the a-axis direction. Calcifying solution treatments of both demineralized sample types

  5. Multiscale Modeling of Bone

    Science.gov (United States)

    2014-12-01

    is an ordered array of bone fibers in a matrix material [1]. It is the dominant form of bone and closely resembles a layered fiber - reinforced ...mineral [3], [14]. These fibers are not independent structures, but exist only within the complex lamellar bone [13], similar to a fiber reinforced ...accuracy of this method. What this model does not provide is the transverse properties or a Poisson ’ s ratio for TC. Thus, we must assume that

  6. Titanium dioxide (TiO2) nanoparticles filled poly(d,l lactid acid) (PDLLA) matrix composites for bone tissue engineering

    NARCIS (Netherlands)

    Gerhardt, L.C.; Jell, G.M.R.; Boccaccini, A.R.

    2007-01-01

    Titanium dioxide (TiO2) nanoparticles were investigated for bone tissue engineering applications with regard to bioactivity and particle cytotoxicity. Composite films on the basis of poly(d,l lactid acid) (PDLLA) filled with 0, 5 and 30 wt% TiO2 nanoparticles were processed by solvent casting.

  7. Detection of irradiated ingredients included in low quantity in non-irradiated food matrix. 1. Extraction and ESR analysis of bones from mechanically recovered poultry meat

    NARCIS (Netherlands)

    Marchioni, Eric; Horvatovich, Péter; Charon, Helène; Kuntz, Florent

    2005-01-01

    Protocol EN 1786 for the detection of irradiated food by electron spin resonance (ESR) spectroscopy was not conceived for the detection of irradiated bone-containing ingredients included in low concentration in non-irradiated food. An enzymatic hydrolysis method, realized at 55 degrees C, has been

  8. Effect of the gamma radiation and common antioxidants on some aspects of osteoblast differentiation during the formation of bone tissue in an in-vivo model; Efecto de la radiacion gamma y antioxidantes comunes sobre algunos aspectos de la diferenciacion de los osteoblastos durante la formacion de tejido oseo en un modelo in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Quinones O, M. G.

    2015-07-01

    Gamma radiation is the emission of energy through short electromagnetic waves to a higher level of frequency with respect to ultraviolet light. This type of energy in the medical application is used as a tool to kill cancer cells in humans, however, adverse damages to its exposure can produce secondary effects in the short and long term depending on the damage in cells and tissues nearby to the irradiation zone, the human body will present various injuries and conditions. In bone tissue, secondary effects that have been observed, is an alteration of the architecture and integrity of bone extracellular matrix of cortical and trabecular tissue, which causes loss of bone density. However, the reason that the bone tissue is affected is not clear, but is believed to be related to the formation of free radicals, which generate oxidative damage in biomolecules of the cells, damaging the tissue structure, organs and systems of the human body. The studies to identify the main reasons that will affect bone tissue as a result of radiotherapy have been carried out by models In-vitro and some In-vivo. In most studies in-vitro with cells with osteoblast phenotype, the results suggest alterations in proliferation and differentiation of these cells. However, the etiology and the role of these changes in disorders and bone injuries as adverse secondary effects of the radiotherapy are very poorly understood to date. In the present study an In-vivo model was used, that are ectopic bone plates which are developed by endochondral ossification, after having implanted demineralized bone particles at 16 days of development, at which time they are constituted by bone tissue. Ectopic bone plates were used with the aim of knowing as gamma radiation indirectly modifies to cellular level the osteoblast differentiation, cells that are involved in the formation and mineralization of bone extracellular matrix. One of the well known effects of gamma radiation is the generation of free radicals

  9. Photothermal radiometry and modulated luminescence examination of demineralized and remineralized dental lesions

    International Nuclear Information System (INIS)

    Hellen, A; Mandelis, A; Finer, Y

    2010-01-01

    Dental caries involves continuous challenges of acid-induced mineral loss and a counteracting process of mineral recovery. As an emerging non-destructive methodology, photothermal radiometry and modulated luminescence (PTR-LUM) has shown promise in measuring changes in tooth mineral content. Human molars (n=37) were subjected to demineralization in acid gel (pH 4.5, 10 days), followed by incubation in remineralisation solutions (pH 6.7, 4 weeks) without or with fluoride (1 or 1000 ppm). PTR-LUM frequency scans (1 Hz - 1 kHz) were performed prior to and during demineralization and remineralization treatments. Transverse Micro-Radiography (TMR) analysis followed at treatment conclusion. The non-fluoridated group exhibited opposite amplitude and phase trends to those of the highly fluoridated group: smaller phase lag and larger amplitude. These results point to a complex interplay between surface and subsurface processes during remineralization, confining the thermal-wave centroid toward the dominating layer.

  10. Assessing the environmental impacts of using demineralized coal for electricity generation

    DEFF Research Database (Denmark)

    Ryberg, Morten; Owsianiak, Mikolaj; Laurent, Alexis

    2014-01-01

    because of the large energy use forrunning the demineralization process. Local and regional environmental impacts were shown to improve from demineralization for low ranking coals or lignite where the ash content is above ≈25 % and the carboncontent is less than ≈50 %. Overall, it can be concluded...... in alkaline and acidic solution to dissolve and remove the ash. This process is well-studied on lab scale but has only to a small extent been tried on a full scale. This assessment is conducted as an aid for further developing thetechnology, allowing for early identification of environmental impacts...... cycle perspective, to assessthe environmental impacts from removing ash in coal, and assess how this affects the combustion in terms of higher thermal efficiency. We assess 260 different data points applying alkali-acid leaching or acidleaching and assess how the treatment and subsequent energy...

  11. Detection for demineralization of dental hard tissues using index-sequenced radiographs

    International Nuclear Information System (INIS)

    Park, Dong Hyun; Park, Young Ho; Kim, Kyung Sook; Park, Jeong Hoon; Lee, Gi Ja; Choi, Sam Jin; Park, Hun Kuk; Choi, Yong Suk; Hwang, Eui Hwan

    2009-01-01

    The purpose of this study was to develop the radiographic technique for detecting the demineralization which is known as indication of dental caries. This technique was based on the comparing of multiple radiographs which was irradiated by multiple X-ray spectra. For the meaningful comparing, the multiple radiographs were reconstructed to the dosimetrically consistent images using a standard material. The difference of resulting images of same target with multiple spectra represents the difference of response of material as regards the spectra. We have found about 10% of demineralization of dental hard tissues particularly in the proximal region through the analyzing of differences. Most intriguing thing in this investigation was that the method to analyze difference shows us to an anatomic structure of dental hard tissues even if absolute values of optical density were excluded during the procedures.

  12. Ph-activated nano-amorphous calcium phosphate-based cement to reduce dental enamel demineralization.

    Science.gov (United States)

    Melo, Mary A S; Weir, Michael D; Passos, Vanara F; Powers, Michael; Xu, Hockin H K

    2017-12-01

    Enamel demineralization is destructive, esthetically compromised, and costly complications for orthodontic patients. Nano-sized amorphous calcium phosphate (NACP) has been explored to address this challenge. The 20% NACP-loaded ortho-cement notably exhibited favorable behavior on reducing demineralization of enamel around brackets in a caries model designed to simulate the carious attack. The 20% NACP-loaded ortho-cement markedly promotes higher calcium and phosphate release at a low pH, and the mineral loss was almost two fold lower and carious lesion depth decreased the by 1/3. This novel approach is promising co-adjuvant route for prevention of dental caries dissemination in millions of patients under orthodontic treatment.

  13. Photothermal radiometry and modulated luminescence examination of demineralized and remineralized dental lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hellen, A; Mandelis, A [Center for Advanced Diffusion-Wave Technologies, University of Toronto, 5 King' s College Road, Toronto, Ontario, M5S 3G8 (Canada); Finer, Y, E-mail: mandelis@mie.utoronto.c [Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, Ontario, M5G 1G6 (Canada)

    2010-03-01

    Dental caries involves continuous challenges of acid-induced mineral loss and a counteracting process of mineral recovery. As an emerging non-destructive methodology, photothermal radiometry and modulated luminescence (PTR-LUM) has shown promise in measuring changes in tooth mineral content. Human molars (n=37) were subjected to demineralization in acid gel (pH 4.5, 10 days), followed by incubation in remineralisation solutions (pH 6.7, 4 weeks) without or with fluoride (1 or 1000 ppm). PTR-LUM frequency scans (1 Hz - 1 kHz) were performed prior to and during demineralization and remineralization treatments. Transverse Micro-Radiography (TMR) analysis followed at treatment conclusion. The non-fluoridated group exhibited opposite amplitude and phase trends to those of the highly fluoridated group: smaller phase lag and larger amplitude. These results point to a complex interplay between surface and subsurface processes during remineralization, confining the thermal-wave centroid toward the dominating layer.

  14. Detection for demineralization of dental hard tissues using index-sequenced radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dong Hyun; Park, Young Ho; Kim, Kyung Sook; Park, Jeong Hoon; Lee, Gi Ja; Choi, Sam Jin; Park, Hun Kuk [Department of Biomedical Engineering, School of Medicine, KyungHee University, Seoul (Korea, Republic of); Choi, Yong Suk; Hwang, Eui Hwan [Department of Oral and Maxillofacial Radiology, Institute of Oral Biology, School of Dentistry, KyungHee University, Seoul (Korea, Republic of)

    2009-06-15

    The purpose of this study was to develop the radiographic technique for detecting the demineralization which is known as indication of dental caries. This technique was based on the comparing of multiple radiographs which was irradiated by multiple X-ray spectra. For the meaningful comparing, the multiple radiographs were reconstructed to the dosimetrically consistent images using a standard material. The difference of resulting images of same target with multiple spectra represents the difference of response of material as regards the spectra. We have found about 10% of demineralization of dental hard tissues particularly in the proximal region through the analyzing of differences. Most intriguing thing in this investigation was that the method to analyze difference shows us to an anatomic structure of dental hard tissues even if absolute values of optical density were excluded during the procedures.

  15. Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units.

    Science.gov (United States)

    Mousavinasab, Sayed-Mostafa; Khoroushi, Maryam; Moharreri, Mohammadreza; Atai, Mohammad

    2014-08-01

    Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05). Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

  16. Temperature changes under demineralized dentin during polymerization of three resin-based restorative materials using QTH and LED units

    Directory of Open Access Journals (Sweden)

    Sayed-Mostafa Mousavinasab

    2014-08-01

    Full Text Available Objectives Light-curing of resin-based materials (RBMs increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs of three different RBMs using quartz tungsten halogen (QTH and light-emitting diode (LED units (LCUs. Materials and Methods Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12 during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey, a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE, and a giomer (Beautifil II, Shofu GmbH, was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p 0.05. Conclusions Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

  17. Analysis of Ion-Exchange Resin Capability of the RSG-GAS Demineralized Water System (GCA01)

    International Nuclear Information System (INIS)

    Diyah Erlina Lestari; Setyo Budi Utomo; Harsono

    2012-01-01

    The Demineralized water system (GCA01) is a system which is function to process raw water to be demineralized water using ion exchange resin unit consisting of a column of cation exchange resins, anion exchange resin column and the column resin mix bed. After certain time the ion exchange resins to be saturated so that is needed regeneration. The RSG-GAS demineralized water system (GCA01) not operated continuously and indication of when does an ion exchange resin regeneration on The RSG-GAS demineralized water system (GCA01) is the water conductivity from anion exchange resin column output indicates ≥ 5μS/cm. Analysis of capability of the ion exchange resin demineralized water system (GCA01) line I has been performed. The analysis was done by comparing the time required in the system operating cycle of regeneration to the next regeneration during the period 2011 and 2012. From the results of the analysis showed the cycle regeneration time is varies. This shows that ion exchange resin capability of the RSG-GAS demineralized water system (GCA01) is varies depending on the raw water quality and success of the regeneration ion exchange resin. (author)

  18. Design and construction of demineralized water production and maintenance system for RA-O nuclear reactor

    International Nuclear Information System (INIS)

    Rumis, D.; Martin, H.R.

    1990-01-01

    The normal operation of zero power RA-O Nuclear Reactor requires a production and maintenance of demineralized water system. This system was designed and built-up during the works for actualization, upgrading and new start up at Cordoba National University of this facility. This paper comments the relevant aspects about the didactical purpose of that system and the details considered for training and practices with it. Similarly, considerations about solids wastes and effluents treatment are discussed. (Author)

  19. Comparison of retention and demineralization inhibition potential of adhesive banding cements in primary teeth.

    Science.gov (United States)

    Prabhakar, A R; Mahantesh, T; Ahuja, Vipin

    2010-01-01

    The purpose of this study was to evaluate the efficacy of banding cements in terms of retentive capability and demineralization inhibition potential. We included 48 non-carious primary mandibular second molar teeth. Preformed stainless steel bands were adapted onto the teeth. All teeth were randomly assigned to four groups: Group I (Adaptation of bands without cementation), Group II (Cementation of bands using conventional Glass Ionomer Cement), Group III (Cementation of bands using Resin-modified Glass Ionomer Cement), Group IV (Cementation of bands using Resin cement), and placed in artificial saliva. Each day, specimens were taken from artificial saliva and suspended in an artificial caries solution for 35 minutes, every 8 hours. At the end of 3 months, retention of bands was estimated using an Instron Universal Testing Machine. The mode of failure was recorded and specimens were sectioned and examined under polarized microscope for demineralized lesions. The mean retention value was highest with resin cement, followed by RMGIC, GIC, and Control group respectively. The RMGIC group showed more favorable modes of failures. All the experimental groups showed significant demineralization inhibition potential. RMGIC is the preferable banding cement and can be used effectively to cement bands in primary dentition.

  20. Effect of Argon Laser on Enamel Demineralization around Orthodontic Brackets: An In Vitro Study

    Science.gov (United States)

    Miresmaeili, Amirfarhang; Etrati Khosroshahi, Mohammad; Motahary, Pouya; Rezaei-Soufi, Loghman; Mahjub, Hossein; Dadashi, Maryam; Farhadian, Nasrin

    2014-01-01

    Objective This study was designed to evaluate the effect of argon laser irradiation on development and progress of enamel demineralization around orthodontic brackets. Materials and Methods: Fifty caries-free, intact human premolars were randomly assigned to one of the following five equal groups: Groups 1 (control) and 2: The brackets were bonded using conventional halogen light for 40s and argon laser for 10s, respectively. Teeth in group 3 were lased with argon laser for 10s before bracket bonding with halogen light. Group 4 was the same as group 3 except that brackets were also bonded with argon laser. In group 5 samples were bonded conventionally, immersed in an artificial caries solution for two days and then irradiated for 10s with argon laser. All samples were subjected to demineralization by artificial caries solution for 10 days. After bracket removal, samples were buccolingually sectioned and evaluated by polarized light microscopy. Decalcified lesion depth in each section was measured by a trained examiner in a blind fashion. Data were analyzed in SPSS 14 using one-way ANOVA and Tukey’s HSD post hoc test. Results: The control group showed the greatest mean lesion depth while group 5 revealed the lowest. The laser-treated groups had significantly lower mean lesion depth compared with the control group (Pbracket bonding can increase caries resistance of intact and demineralized enamel. PMID:25584052

  1. The influence of topical application of grapeseed extract gel on enamel surface hardness after demineralization

    Science.gov (United States)

    Saragih, D. A.; Herda, E.; Triaminingsih, S.

    2017-08-01

    The aim of this study was to analyze the influence of topical application of 6.5% and 12.5% grapeseed extract gels for duration of application 16 and 32 minutes on the enamel surface hardness following tooth demineralization by an energy drink. The samples were 21 bovine teeth that underwent demineralization by immersion in the energy drink for 5 minutes in an incubator at 37°C. The demineralized specimens were randomly divided into a control group and 2 treatment groups. The control group was immersed in artificial saliva for 6 hours at 37°C, whereas the treatment groups were treated with topical 6.5% and 12.5% grapeseed extract gels for durations of 16 and 32 minutes and then immersed in artificial saliva for 6 hours at 37°C. The hardness was measured with a Knoop hardness tester. Statistical analysis by repeated ANOVA and one-way ANOVA revealed a significant increase in the enamel hardness value (p0.05).

  2. Influence of EDC on Dentin-Resin Shear Bond Strength and Demineralized Dentin Thermal Properties

    Directory of Open Access Journals (Sweden)

    Lin Tang

    2016-11-01

    Full Text Available This study aimed to evaluate the bonding strength and thermal properties of demineralized dentin with and without EDC treatment. Sound human molars were randomly divided into seven treatment groups (n = 20: control, 80% ethanol, and five EDC ethanol solutions (0.01–1.0 M. In each group, 16 samples were used for bond strength assessment and 4 samples were used for scanning electron microscopy (SEM analysis. A further 70 intact molars were used to obtain a fine demineralized dentin powder, treated with the same solutions and were evaluated the crosslink degree by ninhydrin test and denaturation temperature (Td by differential scanning calorimetry. EDC-treated specimens (<1.0 M had a higher bond strength, especially 0.3 and 0.5 M group, than the control counterpart. There was a significant drop in bond strength of 1.0 M EDC group. SEM revealed a homogeneous and regular interface under all treatments. EDC treatment significantly increased the demineralized dentin cross-link degree and Td compared with the control and ethanol treatments. The 0.3 and 0.5 M treatments showed the highest cross-link degree and Td. In terms of mechnical and theramal properties consideration, 0.3 and 0.5 M EDC solutions may be favorable for when applied with etch-and-rinse adhesives, but it is still needed further long-term study.

  3. Bone scintiscanning updated.

    Science.gov (United States)

    Lentle, B C; Russell, A S; Percy, J S; Scott, J R; Jackson, F I

    1976-03-01

    Use of modern materials and methods has given bone scintiscanning a larger role in clinical medicine, The safety and ready availability of newer agents have led to its greater use in investigating both benign and malignant disease of bone and joint. Present evidence suggests that abnormal accumulation of 99mTc-polyphosphate and its analogues results from ionic deposition at crystal surfaces in immature bone, this process being facilitated by an increase in bone vascularity. There is, also, a component of matrix localization. These factors are in keeping with the concept that abnormal scintiscan sites represent areas of increased osteoblastic activity, although this may be an oversimplification. Increasing evidence shows that the bone scintiscan is more sensitive than conventional radiography in detecting focal disease of bone, and its ability to reflect the immediate status of bone further complements radiographic findings. The main limitation of this method relates to nonspecificity of the results obtained.

  4. Matrix metalloproteinase-12 (MMP-12) in osteoclasts

    DEFF Research Database (Denmark)

    Hou, Peng; Troen, Tine; Ovejero, Maria C

    2004-01-01

    Osteoclasts require matrix metalloproteinase (MMP) activity and cathepsin K to resorb bone, but the critical MMP has not been identified. Osteoclasts express MMP-9 and MMP-14, which do not appear limiting for resorption, and the expression of additional MMPs is not clear. MMP-12, also called...... bone show MMP-12 expression in osteoclasts in calvariae and long bones. We also demonstrate that recombinant MMP-12 cleaves the putative functional domains of osteopontin and bone sialoprotein, two bone matrix proteins that strongly influence osteoclast activities, such as attachment, spreading...

  5. Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model

    Directory of Open Access Journals (Sweden)

    Barrientos-Durán A

    2014-09-01

    combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone-inducing capabilities both in vitro and in vivo, confirming them as alternatives to current bone-repair therapies. Keywords: human allografts, demineralized bone matrix, cartilage particles, bone regeneration

  6. Increased expression of matrix extracellular phosphoglycoprotein (MEPE in cortical bone of the rat tibia after mechanical loading: identification by oligonucleotide microarray.

    Directory of Open Access Journals (Sweden)

    Christianne M A Reijnders

    Full Text Available Skeletal integrity in humans and animals is maintained by daily mechanical loading. It has been widely accepted that osteocytes function as mechanosensors. Many biochemical signaling molecules are involved in the response of osteocytes to mechanical stimulation. The aim of this study was to identify genes involved in the translation of mechanical stimuli into bone formation. The four-point bending model was used to induce a single period of mechanical loading on the right tibia, while the contra lateral left tibia served as control. Six hours after loading, the effects of mechanical loading on gene-expression were determined with microarray analysis. Protein expression of differentially regulated genes was evaluated with immunohistochemistry. Nine genes were found to exhibit a significant differential gene expression in LOAD compared to control. MEPE, Garnl1, V2R2B, and QFG-TN1 olfactory receptor were up-regulated, and creatine kinase (muscle form, fibrinogen-B beta-polypeptide, monoamine oxidase A, troponin-C and kinesin light chain-C were down-regulated. Validation with real-time RT-PCR analysis confirmed the up-regulation of MEPE and the down-regulation of creatine kinase (muscle form and troponin-C in the loaded tibia. Immunohistochemistry showed that the increase of MEPE protein expression was already detectable six hours after mechanical loading. In conclusion, these genes probably play a role during translation of mechanical stimuli six hours after mechanical loading. The modulation of MEPE expression may indicate a connection between bone mineralization and bone formation after mechanical stimulation.

  7. Effect of light-curable fluoride varnish on enamel demineralization adjacent to orthodontic brackets: an in-vivo study.

    Science.gov (United States)

    Mehta, Anurag; Paramshivam, Ganesh; Chugh, Vinay Kumar; Singh, Surjit; Halkai, Sudha; Kumar, Santosh

    2015-11-01

    The purpose of this in-vivo study was to evaluate the effect of a single application of Clinpro XT (3M ESPE, Pymble, New South Wales, Australia), a light-curable fluoride varnish, on enamel demineralization adjacent to orthodontic brackets. Thirty-eight patients (152 teeth) whose orthodontic treatment involved extraction of 4 first premolars were recruited. Two premolars each were assigned to the control group (no treatment) and the experimental group (received fluoride varnish application). The study was designed as a nonrandomized split-mouth study in which diagonally opposite quadrants received the same treatment. After the bonding procedures, a sectional T-loop was ligated into each bracket to serve as a site for plaque retention for enhanced demineralization. Clinpro XT was applied on the buccal surfaces adjacent to the brackets on all teeth in the experimental group only. Teeth in both groups were extracted after 15 days (n = 30), 30 days (n = 30), 45 days (n = 30), 90 days (n = 18), and 120 days (n = 18). Buccolingual sections were then evaluated under polarized light microscopy. After we excluded the dropouts, the mean depth of the demineralized enamel lesions was measured in final sample of 126 teeth. The Mann-Whitney test was used for comparison of the groups. In the control group, the depths of the demineralized enamel lesions increased from 30 to 120 days, whereas in the experimental group no sign of demineralization was noted throughout the observation period except for 3 teeth. Significant differences in the depths of demineralized lesions were found between the study groups. Clinpro XT light-curable fluoride varnish may be a reasonable alternative in the reduction of enamel demineralization around orthodontic brackets, especially in noncompliant and high-risk patients. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  8. Aneurysmal bone cyst of the temporal bone

    International Nuclear Information System (INIS)

    Buxi, Tarvinder; Sud Seema; Vohra, Rakesh; Sud, Aditi; Singh, Satnam

    2004-01-01

    Aneurysmal bone cyst (ABC) of the temporal bone is rare. The nature of the underlying disorder that converted into the ABC might, however, be difficult to ascertain on imaging as well as on histopathology. The unusual CT and MRI findings in a case of ABC of the temporal bone are presented. This had transdural intracerebral spread with a large component of solid enhancing matrix but no peripheral calcific rim. The patient was an adult of 45 years with a history of headache for more than 1 year Copyright (2004) Blackwell Publishing Asia Pty Ltd

  9. Low-frequency vibration treatment of bone marrow stromal cells induces bone repair in vivo.

    Science.gov (United States)

    He, Shengwei; Zhao, Wenzhi; Zhang, Lu; Mi, Lidong; Du, Guangyu; Sun, Chuanxiu; Sun, Xuegang

    2017-01-01

    To study the effect of low-frequency vibration on bone marrow stromal cell differentiation and potential bone repair in vivo . Forty New Zealand rabbits were randomly divided into five groups with eight rabbits in each group. For each group, bone defects were generated in the left humerus of four rabbits, and in the right humerus of the other four rabbits. To test differentiation, bones were isolated and demineralized, supplemented with bone marrow stromal cells, and implanted into humerus bone defects. Varying frequencies of vibration (0, 12.5, 25, 50, and 100 Hz) were applied to each group for 30 min each day for four weeks. When the bone defects integrated, they were then removed for histological examination. mRNA transcript levels of runt-related transcription factor 2, osteoprotegerin, receptor activator of nuclear factor κ-B ligan, and pre-collagen type 1 α were measured. Humeri implanted with bone marrow stromal cells displayed elevated callus levels and wider, more prevalent, and denser trabeculae following treatment at 25 and 50 Hz. The mRNA levels of runt-related transcription factor 2, osteoprotegerin, receptor activator of nuclear factor κ-B ligand, and pre-collagen type 1 α were also markedly higher following 25 and 50 Hz treatment. Low frequency (25-50 Hz) vibration in vivo can promote bone marrow stromal cell differentiation and repair bone injury.

  10. Low-frequency vibration treatment of bone marrow stromal cells induces bone repair in vivo

    Directory of Open Access Journals (Sweden)

    Shengwei He

    2017-01-01

    Full Text Available Objective(s:To study the effect of low-frequency vibration on bone marrow stromal cell differentiation and potential bone repair in vivo. Materials and Methods:Forty New Zealand rabbits were randomly divided into five groups with eight rabbits in each group. For each group, bone defects were generated in the left humerus of four rabbits, and in the right humerus of the other four rabbits. To test differentiation, bones were isolated and demineralized, supplemented with bone marrow stromal cells, and implanted into humerus bone defects. Varying frequencies of vibration (0, 12.5, 25, 50, and 100 Hz were applied to each group for 30 min each day for four weeks. When the bone defects integrated, they were then removed for histological examination. mRNA transcript levels of runt-related transcription factor 2, osteoprotegerin, receptor activator of nuclear factor k-B ligan, and pre-collagen type 1 a were measured. Results:Humeri implanted with bone marrow stromal cells displayed elevated callus levels and wider, more prevalent, and denser trabeculae following treatment at 25 and 50 Hz. The mRNA levels of runt-related transcription factor 2, osteoprotegerin, receptor activator of nuclear factor k-B ligand, and pre-collagen type 1 a were also markedly higher following 25 and 50 Hz treatment. Conclusion:Low frequency (25–50 Hz vibration in vivo can promote bone marrow stromal cell differentiation and repair bone injury.

  11. Bone tumors

    International Nuclear Information System (INIS)

    Unni, K.K.

    1988-01-01

    This book contains the proceedings on bone tumors. Topics covered include: Bone tumor imaging: Contribution of CT and MRI, staging of bone tumors, perind cell tumors of bone, and metastatic bone disease

  12. Bone marrow edema syndrome

    International Nuclear Information System (INIS)

    Korompilias, Anastasios V.; Lykissas, Marios G.; Beris, Alexandros E.; Karantanas, Apostolos H.

    2009-01-01

    Bone marrow edema syndrome (BMES) refers to transient clinical conditions with unknown pathogenic mechanism, such as transient osteoporosis of the hip (TOH), regional migratory osteoporosis (RMO), and reflex sympathetic dystrophy (RSD). BMES is primarily characterized by bone marrow edema (BME) pattern. The disease mainly affects the hip, the knee, and the ankle of middle-aged males. Many hypotheses have been proposed to explain the pathogenesis of the disease. Unfortunately, the etiology of BMES remains obscure. The hallmark that separates BMES from other conditions presented with BME pattern is its self-limited nature. Laboratory tests usually do not contribute to the diagnosis. Histological examination of the lesion is unnecessary. Plain radiographs may reveal regional osseous demineralization. Magnetic resonance imaging is mainly used for the early diagnosis and monitoring the progression of the disease. Early differentiation from other aggressive conditions with long-term sequelae is essential in order to avoid unnecessary treatment. Clinical entities, such as TOH, RMO, and RSD are spontaneously resolving, and surgical treatment is not needed. On the other hand, early differential diagnosis and surgical treatment in case of osteonecrosis is of crucial importance. (orig.)

  13. Combining casein phosphopeptide-amorphous calcium phosphate with fluoride: synergistic remineralization potential of artificially demineralized enamel or not?

    Science.gov (United States)

    Elsayad, Iman; Sakr, Amal; Badr, Yahia

    2009-07-01

    Recaldent is a product of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). The remineralizing potential of CPP-ACP per se, or when combined with 0.22% Fl gel on artificially demineralized enamel using laser florescence, is investigated. Mesial surfaces of 15 sound human molars are tested using a He-Cd laser beam at 441.5 nm with 18-mW power as an excitation source on a suitable setup based on a Spex 750-M monochromator provided with a photomultiplier tube (PMT) for detection of collected autofluorescence from sound enamel. Mesial surfaces are subjected to demineralization for ten days. The spectra from demineralized enamel are measured. Teeth are divided into three groups according to the remineralizing regimen: group 1 Recaldent per se, group 2 Recaldent combined with fluoride gel and ACP, and group 3 artificial saliva as a positive control. After following these protocols for three weeks, the spectra from the remineralized enamel are measured. The spectra of enamel autofluorescence are recorded and normalized to peak intensity at about 540 nm to compare spectra from sound, demineralized, and remineralized enamel surfaces. A slight red shift occurred in spectra from demineralized enamel, while a blue shift may occur in remineralized enamel. Group 2 shows the highest remineralizing potential. Combining fluoride and ACP with CPP-ACP can give a synergistic effect on enamel remineralization.

  14. Biomaterials and bone mechanotransduction

    Science.gov (United States)

    Sikavitsas, V. I.; Temenoff, J. S.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    Bone is an extremely complex tissue that provides many essential functions in the body. Bone tissue engineering holds great promise in providing strategies that will result in complete regeneration of bone and restoration of its function. Currently, such strategies include the transplantation of highly porous scaffolds seeded with cells. Prior to transplantation the seeded cells are cultured in vitro in order for the cells to proliferate, differentiate and generate extracellular matrix. Factors that can affect cellular function include the cell-biomaterial interaction, as well as the biochemical and the mechanical environment. To optimize culture conditions, good understanding of these parameters is necessary. The new developments in bone biology, bone cell mechanotransduction, and cell-surface interactions are reviewed here to demonstrate that bone mechanotransduction is strongly influenced by the biomaterial properties.

  15. Effects of Treatment with Various Remineralizing Agents on the Microhardness of Demineralized Enamel Surface

    Directory of Open Access Journals (Sweden)

    Kiana Salehzadeh Esfahani

    2015-12-01

    Full Text Available Background and aims. Remineralization of incipient caries is one of the goals in dental health care. The present study aimed at comparing the effects of casein phosphopeptide-amorphous calcium phosphate complex (CPP-ACP, Remin Pro®, and 5% sodium fluoride varnish on remineralization of enamel lesions. Materials and methods. In this in vitro study, 60 enamel samples were randomly allocated to six groups of 10. After four days of immersion in demineralizing solution, microhardness of all samples was measured. Afterward, groups 1-3 under-went one-time treatment with fluoride varnish, CPP-ACP, and Remin Pro®, respectively. Microhardness of groups 4-6 was measured not only after one-month treatment with the above-mentioned materials (for eight hours a day, but also after re-exposing to the demineralizing solution. The results were analyzed by one-way analysis of variance (ANOVA, repeated measures ANOVA, and Fisher’s least significant difference (LSD test. Results. None of the regimens could increase microhardness in groups 1-3. However, one-month treatment regimens in groups 4-6 caused a significant increase in microhardness. The greatest microhardness was detected in the group treated with CPP-ACP (P = 0.001. In addition, although microhardness reduced following re-demineralization in all three groups, the mean reduction was minimum in the CPP-ACP-treated group (P < 0.001. Conclusion. While long-term repeated application of all compounds improved microhardness, the remineralization potential of CPP-ACP was significantly higher than that of Remin Pro® and sodium fluoride varnish.

  16. Combination effect of fluoride dentifrices and varnish on deciduous enamel demineralization

    Directory of Open Access Journals (Sweden)

    Alessandra Gatti

    2011-10-01

    Full Text Available The aim of this study was to evaluate the anticaries potential of 500 or 1100 ppm F dentifrices combined with fluoride varnish using a pH-cycling regimen. Seventy primary canines were covered with nail polish, leaving a 4×4 mm window on their buccal surface, and randomly assigned into 7 groups (n = 10: S: sound enamel not submitted to the pH-cycling regimen or treatment; N: negative control, submitted to the pH-cycling regimen without any treatment; D1 and D2: subjected to the pH-cycling regimen and treated twice daily with 1100 or 500 ppm F dentifrice, respectively; VF: fluoride varnish (subjected to F-varnish before and in the middle of the pH-cycling regimen; and VF+D1 and VF+D2. After 10 days, the teeth were sectioned, and enamel demineralization was assessed by cross-sectional hardness at different distances from the dental surface. Data were analyzed using a two-way ANOVA followed by Tukey's test. Dentifrice with 1100 ppm F and the combination of F-varnish with the dentifrices significantly reduced enamel demineralization compared with the negative control (p 0.05. The effect of combining F-varnish with the dentifrices was not greater than the effect of the dentifrices alone (p < 0.05. The data suggest that the combination of F-varnish with dentifrices containing 500 and 1100 ppm F is not more effective in reducing demineralization in primary teeth than the isolated effect of dentifrice containing 1100 ppm F.

  17. [Differential diagnosis of dental enamel focal demineralization and fluorosis by means of spectrophotometry].

    Science.gov (United States)

    Makarova, N E; Vinnichenko, Yu A

    2018-01-01

    The article presents the results of spectrophotometric tooth enamel scanning for differential diagnosis of focal enamel demineralization and fluorosis. Research was conducted in vivo on teeth affected by these diseases. VITA EasyShade spectrophotometer measurements were made on the affected area and on the visually healthy part of enamel. The lightness appeared as the only one differential significant optical characteristics of tooth enamel. Lightness metrics were higher in the case of initial caries than on the healthy part of enamel when these metrics were lower in the case of fluorosis than on the healthy part of enamel.

  18. Effect of fluoridated milk on enamel demineralization adjacent to fixed orthodontic appliances

    DEFF Research Database (Denmark)

    Sköld-Larsson, Kerstin; Sollenius, Ola; Karlsson, Lena

    2012-01-01

    Abstract Objective. To investigate the effect of daily intake of fluoridated milk on enamel demineralization adjacent to fixed orthodontic brackets assessed with quantitative light-induced fluorescence (QLF). Materials and methods. Sixty-four healthy adolescents (13-18 years) undergoing orthodontic...... amount of milk without fluoride. The intervention period was 12 weeks and the end-point was mineral gain or loss in enamel, assessed by QLF on two selected sites from each individual. The attrition rate was 12.5% and 112 sites were included in the final evaluation. Results. There was no statistically...

  19. Higher number of pentosidine cross-links induced by ribose does not alter tissue stiffness of cancellous bone

    Energy Technology Data Exchange (ETDEWEB)

    Willems, Nop M.B.K., E-mail: n.willems@acta.nl [Dept. of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Langenbach, Geerling E.J. [Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Stoop, Reinout [Dept. of Metabolic Health Research, TNO, P.O. Box 2215, 2301 CE Leiden (Netherlands); Toonder, Jaap M.J. den [Dept. of Mechanical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Mulder, Lars [Dept. of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Zentner, Andrej [Dept. of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Everts, Vincent [Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands)

    2014-09-01

    The role of mature collagen cross-links, pentosidine (Pen) cross-links in particular, in the micromechanical properties of cancellous bone is unknown. The aim of this study was to examine nonenzymatic glycation effects on tissue stiffness of demineralized and non-demineralized cancellous bone. A total of 60 bone samples were derived from mandibular condyles of six pigs, and assigned to either control or experimental groups. Experimental handling included incubation in phosphate buffered saline alone or with 0.2 M ribose at 37 °C for 15 days and, in some of the samples, subsequent complete demineralization of the sample surface using 8% EDTA. Before and after experimental handling, bone microarchitecture and tissue mineral density were examined by means of microcomputed tomography. After experimental handling, the collagen content and the number of Pen, hydroxylysylpyridinoline (HP), and lysylpyridinoline (LP) cross-links were estimated using HPLC, and tissue stiffness was assessed by means of nanoindentation. Ribose treatment caused an up to 300-fold increase in the number of Pen cross-links compared to nonribose-incubated controls, but did not affect the number of HP and LP cross-links. This increase in the number of Pen cross-links had no influence on tissue stiffness of both demineralized and nondemineralized bone samples. These findings suggest that Pen cross-links do not play a significant role in bone tissue stiffness. - Highlights: • The assessment of effects of glycation in bone using HPLC, microCT, and nanoindentation • Ribose incubation: 300‐fold increase in the number of pentosidine cross-links • 300‐fold increase in the number of pentosidine cross-links: no changes in bone tissue stiffness.

  20. In-vitro study investigating influence of toothpaste containing green tea extract on the microhardness of demineralized human enamel

    Science.gov (United States)

    Febrian, K.; Triaminingsih, S.; Indrani, DJ

    2017-08-01

    The aim of this study was to analyze the influence of toothpaste containing green tea extract on the microhardness of demineralized enamel. Human tooth, which was demineralised in citric acid solution, had a toothpaste containing green tea extract of concentration of 5, 10 or 15% application. Microhardness measurement was carried out on each enamel surface of the teeth for initial, after the demineralization and after application of the tooth pastes. It showed that there was significant decrease between enamel microhardness of the teeth at the initial condition and after demineralization. After application of the toothpaste containing green tea extract of each concentration the microhardnss increased significantly. However, there the microhardness was insignificant between the applications of each green tea concentration.

  1. Effect of local hemostatics on bone induction in rats: a comparative study of bone wax, fibrin-collagen paste, and bioerodible polyorthoester with and without gentamicin

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G

    1992-01-01

    Local hemostatics for osseous tissue should preferably be absorbable and biocompatible and should not inhibit osteogenesis. The tissue response and effect on demineralized bone-induced heterotopic osteogenesis in the abdominal muscle of 120 male Wistar rats by different local hemostatics were...... evaluated by light microscopy and 85Sr uptake analyses. Non-absorbable bone wax of 88% beeswax and absorbable bovine fibrin-collagen paste both significantly inhibited osteoinduction, whereas a bioerodible polyorthoester drug delivery system with or without 4% gentamicin did not. Bone wax was not absorbed...

  2. Premature loss of bone remodeling compartment canopies is associated with deficient bone formation

    DEFF Research Database (Denmark)

    Jensen, Pia Rosgaard; Andersen, Thomas Levin; Søe, Kent

    2011-01-01

    A remarkable property of bone remodeling is that osteoblasts form bone matrix exactly where and when osteoclasts have removed it. The bone remodeling compartment (BRC) canopies that cover bone surfaces undergoing remodeling, were proposed to be critical players in this mechanism. Here, we provide...

  3. Influence of fluoride varnish on shear bond strength of a universal adhesive on intact and demineralized enamel.

    Science.gov (United States)

    Ortiz-Ruiz, Antonio José; Muñoz-Gómez, Iban Jesús; Pérez-Pardo, Ana; Germán-Cecilia, Concepción; Martínez-Beneyto, Yolanda; Vicente, Ascensión

    2018-04-27

    The aim was to evaluate the effect of fluoride varnish on the shear bond strength (SBS) on polished and non-polished intact and demineralized enamel. Bovine incisors (half demineralized) were used. Bifluorid 12™ was applied. Bonding was made with Futurabond ® M + and GrandioSO, 24 h and 7 days after varnishing. In some groups, varnish was removed by polishing before bonding. SBS was measured. Fracture type was determined by stereomicroscopy and scanning electron microscope (SEM) observations of the enamel surface were made. Between-group differences were determined by one-way ANOVA and the Tukey test. Associations between study factors and fracture modes were analysed using contingency tables and Pearson's chi-squared test. For intact enamel, SBS on varnished enamel at 24 h was significantly less than in the other groups. SBS recovered 7 days after varnishing. Varnish elimination after 24 h significantly increased the SBS. However, removal at 7 days did not modify SBS. SBS on demineralized enamel groups was significantly less than in intact enamel, except for demineralized enamel varnished and removed at 7 days. Demineralized enamel was associated with cohesive enamel fractures and intact enamel with cohesive fractures of the composite and adhesive fractures. SEM of varnish surfaces showed a homogenous layer scattered with amorphous precipitate. In conclusion, on intact enamel fluoride varnish had a negative effect on SBS at 24 h, which disappeared after 7 days. On demineralized enamel, varnish did not reduce SBS at either time. Polishing the varnished enamel surface showed a similar SBS to intact enamel after 7 days.

  4. Matrix theory

    CERN Document Server

    Franklin, Joel N

    2003-01-01

    Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.

  5. Immobilization of cross linked Col-I–OPN bone matrix protein on aminolysed PCL surfaces enhances initial biocompatibility of human adipogenic mesenchymal stem cells (hADMSC)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hee; Jyoti, Md. Anirban; Song, Ho-Yeon, E-mail: songmic@sch.ac.kr

    2014-06-01

    In bone tissue engineering surface modification is considered as one of the important ways of fabricating successful biocompatible material. Addition of biologically active functionality on the surfaces has been tried for improving the overall biocompatibility of the system. In this study poly-ε-caprolactone film surfaces have been modified through aminolysis and immobilization process. Collagen type I (COL-I) and osteopontin (OPN), which play an important role in osteogenesis, was immobilized onto PCL films followed by aminolysis treatment using 1,6-hexanediamine. Characterization of animolysed and immobilized surfaces were done by a number techniques using scanning electron microscopy (SEM), FT-IR, XPS, ninhydrin staining, SDS-PAGE and confocal microscopy and compared between the modified and un-modified surfaces. Results of the successive experiments showed that aminolysis treatment was homogeneously achieved which helped to entrap or immobilize Col-I–OPN proteins on surfaces of PCL film. In vitro studies with human adipogenic mesenchymal stem cells (hADMSC) also confirmed the attachment and proliferation of cells was better in modified PCL surfaces than the unmodified surfaces. SEM, confocal microscopy and MTT assay showed a significant increase in cell spreading, attachment and proliferations on the biofunctionalized surfaces compared to the unmodified PCL surfaces at all-time points indicating the success of surface biofunctionalization.

  6. Crud removal with deep bed type condensate demineralizer in Tokai-2 BWR

    International Nuclear Information System (INIS)

    Abe, Ayumi; Takiguchi, Hideki; Numata, Kunio; Saito, Toshihiko

    1996-01-01

    The major objective and functions for the installation of the deep bed type condensate polishers in BWR power plants is to remove both ionic impurities caused by sea water leakage and suspended impurities called crud mainly consisting of metal oxides which are produced from metal corrosion. In considering the reduction of occupational radiation exposure level, it is extremely important to remove the crud effectively. In recent Japanese BWR power plants, condensate pre-filters with powdered ion exchange resins or with hollow fiber membrane have been installed to remove the crud at the upper stream of the deep bed polishers. In such plants, the crud removal is conventionally the secondary objective for the deep bed polishers. The Japan Atomic Power Company has introduced the small particle ion exchange resin and a soak regeneration method since April 1985, and then applied the low cross-linked resin since July 1995 at Tokai-2 Power Station, to improve the crud removal performance by using only deep bed type condensate demineralizer, and as a result condensate demineralizer outlet iron level has been kept below 1 ppb since 1991

  7. Enamel resistance to demineralization following Er:YAG laser etching for bonding orthodontic brackets

    Science.gov (United States)

    Ahrari, Farzaneh; Poosti, Maryam; Motahari, Pourya

    2012-01-01

    Background: Several studies have shown that laser-etching of enamel for bonding orthodontic brackets could be an appropriate alternative for acid conditioning, since a potential advantage of laser could or might be caries prevention. This study compared enamel resistance to demineralization following etching with acid phosphoric or Er:YAG laser for bonding orthodontic brackets. Materials and Methods: Fifty sound human premolars were divided into two equal groups. In the first group, enamel was etched with 37% phosphoric acid for 15 seconds. In the second group, Er:YAG laser (wavelength, 2 940 nm; 300 mJ/pulse, 10 pulses per second, 10 seconds) was used for tooth conditioning. The teeth were subjected to 4-day PH-cycling process to induce caries-like lesions. The teeth were then sectioned and the surface area of the lesion was calculated in each microphotographs and expressed in pixel. The total surface of each specimen was 196 608 pixels. Results: Mean lesion areas were 7 171 and 7532 pixels for Laser-etched and Acid-etched groups, respectively. The two sample t-test showed that there was no significant difference in lesion area between the two groups (P = 0.914). Conclusion: Although Er:YAG laser seems promising for etching enamel before bonding orthodontic brackets, it does not reduce enamel demineralization when exposed to acid challenge. PMID:23162591

  8. Thermophotonic lock-in imaging of early demineralized and carious lesions in human teeth

    Science.gov (United States)

    Tabatabaei, Nima; Mandelis, Andreas; Amaechi, Bennett Tochukwu

    2011-07-01

    As an extension of frequency-domain photothermal radiometry, a novel dental-imaging modality, thermophotonic lock-in imaging (TPLI), is introduced. This methodology uses photothermal wave principles and is capable of detecting early carious lesions and cracks on occlusal and approximal surfaces as well as early caries induced by artificial demineralizing solutions. The increased light scattering and absorption within early carious lesions increases the thermal-wave amplitude and shifts the thermal-wave centroid, producing contrast between the carious lesion and the intact enamel in both amplitude and phase images. Samples with artificial and natural occlusal and approximal caries were examined in this study. Thermophotonic effective detection depth is controlled by the modulation frequency according to the well-known concept of thermal diffusion length. TPLI phase images are emissivity normalized and therefore insensitive to the presence of stains. Amplitude images, on the other hand, provide integrated information from deeper enamel regions. It is concluded that the results of our noninvasive, noncontacting imaging methodology exhibit higher sensitivity to very early demineralization than dental radiographs and are in agreement with the destructive transverse microradiography mineral density profiles.

  9. Synergistic effect of fluoride and laser irradiation for the inhibition of the demineralization of dental enamel

    Science.gov (United States)

    Lee, Raymond; Chan, Kenneth H.; Jew, Jamison; Simon, Jacob C.; Fried, Daniel

    2017-02-01

    Both laser irradiation and fluoride treatment alone are known to provide increased resistance to acid dissolution. CO2 lasers tuned to a wavelength of 9.3 μm can be used to efficiently convert the carbonated hydroxyapatite of enamel to a much more acid resistant purer phase hydroxyapatite (HAP). Further studies have shown that fluoride application to HAP yields fluoroapatite (FAP) which is even more resistant against acid dissolution. Previous studies show that CO2 lasers and fluoride treatments interact synergistically to provide significantly higher protection than either method alone, but the mechanism of interaction has not been elucidated. We recently observed the formation of microcracks or a "crazed" zone in the irradiated region that is resistant to demineralization using high-resolution microscopy. The microcracks are formed due to the slight contraction of enamel due to transformation of carbonated hydroxyapatite to the more acid resistant pure phase hydroxyapatite (HAP) that has a smaller lattice. In this study, we test the hypothesis that these small cracks will provide greater adhesion for topical fluoride for greater protection against acid demineralization.

  10. Binding of a cementum attachment protein to extracellular matrix components and to dental surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pitaru, S; Hekmati, H [Department of Oral Biology, Goldschleger School of Dental Medicine, Tel Aviv University (Israel); Savion, N [Goldschleger Eye Institute, Sackler School of Medicine, Tel Aviv University (Israel); Olsen, S; Narayanan, S A [Department of Pathology, School of Medicine, University of Washington, Seattle, Washington (United States)

    1992-01-01

    Cementum proteins (CP) have been shown to mediate cell attachment. Among these, a 55 kDa protein was isolated. The purpose of the present study was to assess the capacity of CP to bind to non-demineralized and demineralized root surfaces and to support cell attachment to dentin. CP were prepared by sequential extraction of bovine cementum with 25 mM EDTA, 0.5 M acetic acid followed by 4 M guanidine HCl. The latter was subjected to ion exchange chromatography on a DEAE-3SW column and eluted stepwise with a 0-0.5 M NaCl gradient. CP were labelled with [sup 125]I and the capacity of [sup 125]I-CP to bind to mineralized and partially demineralized dentin, synthetic hydroxyapatite, collagen, fibronectin and fibrillar collagen-fibronectin cimplex was assessed. It was found that CP bind specifically to mineralized dentin and synthetic hydroxyapatite but not to demineralized dentin. The specific binding was 60% of the total binding. SDS-PAGE analysis of the proteins bound to dentin indicated that the main bound protein had a molecular weight of 55 kDa. CP exhibited high affinity for fibronectin (k[sub D] = 1.56 x 10[sup -10] M) and fibronectincollagen complex, but their binding to either molecular or fibrillar collagen was negligible. It is suggested that CP may play an important role in the attachment of cells of the periodontium to cementum extracellular matrix during homeostasis and regeneration. (au).

  11. Photoacoustic and ultrasound characterization of bone composition

    Science.gov (United States)

    Lashkari, Bahman; Yang, Lifeng; Liu, Lixian; Tan, Joel W. Y.; Mandelis, Andreas

    2015-02-01

    This study examines the sensitivity and specificity of backscattered ultrasound (US) and backscattering photoacoustic (PA) signals for bone composition variation assessment. The conventional approach in the evaluation of bone health relies on measurement of bone mineral density (BMD). Although, a crucial and probably the most important parameter, BMD is not the only factor defining the bone health. New trends in osteoporosis research, also pursue the changes in collagen content and cross-links with bone diseases and aging. Therefore, any non-invasive method that can assess any of these parameters can improve the diagnostic tools and also can help with the biomedical studies on the diseases themselves. Our previous studies show that both US and PA are responsive to changes in the BMD, PA is, in addition, sensitive to changes in the collagen content of the bone. Measurements were performed on bone samples before and after mild demineralization and decollagenization at the exact same points. Results show that combining both modalities can enhance the sensitivity and specificity of diagnostic tool.

  12. Role of bone scan in rheumatic disease

    International Nuclear Information System (INIS)

    Choi, Yun Young

    2003-01-01

    Rheumatic diseases can be categorized by pathology into several specific types of musculoskeletal problems, including synovitis (e.g. rheumatoid arthritis), enthesopathy (e.g. ankylosing spondylitis) and cartilage degeneration (e.g. osteoarthritis). Skeletal radiographs have contributed to the diagnosis of these articular diseases, and some disease entities need typical radiographic changes as a factor of the diagnostic criteria. However, they sometimes show normal radiographic findings in the early stage of disease, when there is demineralization of less than 30-50%. Bone scans have also been used in arthritis, but not widely because the findings are nonspecific and it is thought that bone scans do not add significant information to routine radiography. Bone scans do however play a different role than simple radiography, and it is a complementary imaging method in the course of management of arthritis. The image quality of bone scans can be improved by obtaining regional views and images under al pin-hole collimator, and through a variety of scintigraphic techniques including the three phase bone scan and bone SPECT. Therefore, bone scans could improve the diagnostic value, and answer multiple clinical questions, based on the pathophysiology of various forms of arthritis

  13. Migration of bone marrow and cord blood mesenchymal stem cells in vitro is regulated by stromal-derived factor-1-CXCR4 and hepatocyte growth factor-c-met axes and involves matrix metalloproteinases.

    Science.gov (United States)

    Son, Bo-Ra; Marquez-Curtis, Leah A; Kucia, Magda; Wysoczynski, Marcin; Turner, A Robert; Ratajczak, Janina; Ratajczak, Mariusz Z; Janowska-Wieczorek, Anna

    2006-05-01

    Human mesenchymal stem cells (MSCs) are increasingly being considered in cell-based therapeutic strategies for regeneration of various organs/tissues. However, the signals required for their homing and recruitment to injured sites are not yet fully understood. Because stromal-derived factor (SDF)-1 and hepatocyte growth factor (HGF) become up-regulated during tissue/organ damage, in this study we examined whether these factors chemoattract ex vivo-expanded MSCs derived from bone marrow (BM) and umbilical cord blood (CB). Specifically, we investigated the expression by MSCs of CXCR4 and c-met, the cognate receptors of SDF-1 and HGF, and their functionality after early and late passages of MSCs. We also determined whether MSCs express matrix metalloproteinases (MMPs), including membrane type 1 (MT1)-MMP, matrix-degrading enzymes that facilitate the trafficking of hematopoietic stem cells. We maintained expanded BM- or CB-derived MSCs for up to 15-18 passages with monitoring of the expression of 1) various tissue markers (cardiac and skeletal muscle, neural, liver, and endothelial cells), 2) functional CXCR4 and c-met, and 3) MMPs. We found that for up to 15-18 passages, both BM- and CB-derived MSCs 1) express mRNA for cardiac, muscle, neural, and liver markers, as well as the vascular endothelial (VE) marker VE-cadherin; 2) express CXCR4 and c-met receptors and are strongly attracted by SDF-1 and HGF gradients; 3) express MMP-2 and MT1-MMP transcripts and proteins; and 4) are chemo-invasive across the reconstituted basement membrane Matrigel. These in vitro results suggest that the SDF-1-CXCR4 and HGF-c-met axes, along with MMPs, may be involved in recruitment of expanded MSCs to damaged tissues.

  14. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

  15. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    International Nuclear Information System (INIS)

    Sockalingam, K.; Abdullah, H. Z.

    2015-01-01

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties

  16. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

  17. Differential Expression of Matrix Metalloproteinase-2 Expression in Disseminated Tumor Cells and Micrometastasis in Bone Marrow of Patients with Nonmetastatic and Metastatic Prostate Cancer: Theoretical Considerations and Clinical Implications—An Immunocytochemical Study

    Directory of Open Access Journals (Sweden)

    Nigel P. Murray

    2012-01-01

    Full Text Available Matrix metalloproteinase-2 (MMP-2 is important in the dissemination and invasion of tumor cells and activates angiogenesis. We present an immunocytochemical study of MMP-2 expression in circulating prostate cells (CPCs, disseminated tumor cells (DTCs, and micrometastasis (mM in bone marrow of men with prostate cancer. Methods and Patients. Tumor cells were identified with anti-PSA immunocytochemistry. Positive samples underwent processing with anti-MMP-2, its expression was compared with Gleason score, concordance of expression, and metastatic and nonmetastatic disease. Results. 215 men participated, CPCs were detected in 62.7%, DTCs in 62.2%, and mM in 71.4% in nonmetastatic cancer; in metastatic cancer all had CPCs, DTCs, and mM detected. All CPCs and DTCs expressed MMP-2; in mM MMP-2 expression was positively associated with increasing Gleason score. MMP-2 expression in CPCs and DTCs showed concordance. In low grade tumors, mM and surrounding stromal cells were MMP-2 negative, with variable expression in high grade tumors; in metastatic disease, both mM and stromal cells were MMP-2 positive. Conclusions. CPCs and DTCs are different from mM, with inhibition of MMP-2 expression in mM of low grade tumors. With disease progression, MMP-2 expression increases in both mM and surrounding stromal cells, with implications for the use of bisphosphonates or MMP-2 inhibitors.

  18. EFFECT OF FREQUENT CONSUMPTION OF STARCHY FOOD ITEMS ON ENAMEL AND DENTIN DEMINERALIZATION AND ON PLAQUE PH IN-SITU

    NARCIS (Netherlands)

    LINGSTROM, P; BIRKHED, D; RUBEN, J; ARENDS, J

    The aim of this cross-over study was to determine the cariogenic potential of starchy food items as between-meal snacks. This was done by measuring demineralization of human enamel and dentin as well as the pH of dental plaque in situ. Eight volunteers with complete dentures carried two enamel and

  19. Role of fluoridated carbamide peroxide whitening gel in the remineralization of demineralized enamel: An in vitro study.

    Science.gov (United States)

    Bollineni, Swetha; Janga, Ravi Kumar; Venugopal, L; Reddy, Indukuri Ravikishore; Babu, P Ravisekhar; Kumar, Sunil S

    2014-05-01

    The use of self-administered carbamide peroxide bleaching gels has become increasingly popular for whitening of discolored vital teeth. Studies have reported that its use may induce increased levels of sensitivity and surface roughness of the tooth due to demineralization. This study evaluates the effect of fluoride addition to the bleaching agent - its remineralizing capacity and alterations in the whitening properties. Twenty-four extracted lower third molar teeth, with the pretreatment shade determined, were taken up in the study. Each tooth was sectioned into four and labeled as groups A, B, C, and D. The tooth quadrants in group A-C were demineralized; groups A and B were treated with 10% carbamide peroxide gel (group-A without fluoride and group-B with 0.463% fluoride addition) (no further treatment was carried out for group c) group-D remained as the control. The post-treatment shade was determined. The tooth samples were sectioned (approximately 200 μm) for evaluation under a light microscope. The depth of demineralization was analyzed at five different equidistant points. Statistical analysis was carried out with t-tests, accepting ≤0.05 as significant. Addition of fluoride caused remineralization of demineralized enamel. The tooth whitening system showed that the remineralization properties did not affect the whitening properties.

  20. Bone Marrow-Derived Mesenchymal Stromal Cells Enhanced by Platelet-Rich Plasma Maintain Adhesion to Scaffolds in Arthroscopic Simulation.

    Science.gov (United States)

    Hoberman, Alexander R; Cirino, Carl; McCarthy, Mary Beth; Cote, Mark P; Pauzenberger, Leo; Beitzel, Knut; Mazzocca, Augustus D; Dyrna, Felix

    2018-03-01

    To assess the response of bone marrow-derived mesenchymal stromal cells (bMSCs) enhanced by platelet-rich plasma (PRP) in the setting of a normal human tendon (NHT), a demineralized bone matrix (DBM), and a fibrin scaffold (FS) with simulated arthroscopic mechanical washout stress. Bone marrow was aspirated from the humeral head and concentrated. BMSCs were counted, plated, and grown to confluence. Cells were seeded onto 3 different scaffolds: (1) NHT, (2) DBM, and (3) FS. Each scaffold was treated with a combination of (+)/(-) PRP and (+)/(-) arthroscopic washout simulation. A period of 60 minutes was allotted before arthroscopic washout. Adhesion, proliferation, and differentiation assays were performed to assess cellular activity in each condition. Significant differences were seen in mesenchymal stromal cell adhesion, proliferation, and differentiation among the scaffolds. DBM and FS showed superior results to NHT for cell adhesion, proliferation, and differentiation. PRP significantly enhanced cellular adhesion, proliferation, and differentiation. Arthroscopic simulation did not significantly decrease bMSC adhesion. We found that the type of scaffold impacts bMSCs' behavior. Both scaffolds (DBM and FS) were superior to NHT. The use of an arthroscopic simulator did not significantly decrease the adhesion of bMSCs to the scaffolds nor did it decrease their biologic differentiation potential. In addition, PRP enhanced cellular adhesion, proliferation, and differentiation. Improved healing after tendon repair can lead to better clinical outcomes. BMSCs are attractive for enhancing healing given their accessibility and regenerative potential. Application of bMSCs using scaffolds as cell carriers relies on arthroscopic feasibility. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  1. Scanning electron microscopy of bone.

    Science.gov (United States)

    Boyde, Alan

    2012-01-01

    This chapter described methods for Scanning Electron Microscopical imaging of bone and bone cells. Backscattered electron (BSE) imaging is by far the most useful in the bone field, followed by secondary electrons (SE) and the energy dispersive X-ray (EDX) analytical modes. This chapter considers preparing and imaging samples of unembedded bone having 3D detail in a 3D surface, topography-free, polished or micromilled, resin-embedded block surfaces, and resin casts of space in bone matrix. The chapter considers methods for fixation, drying, looking at undersides of bone cells, and coating. Maceration with alkaline bacterial pronase, hypochlorite, hydrogen peroxide, and sodium or potassium hydroxide to remove cells and unmineralised matrix is described in detail. Attention is given especially to methods for 3D BSE SEM imaging of bone samples and recommendations for the types of resin embedding of bone for BSE imaging are given. Correlated confocal and SEM imaging of PMMA-embedded bone requires the use of glycerol to coverslip. Cathodoluminescence (CL) mode SEM imaging is an alternative for visualising fluorescent mineralising front labels such as calcein and tetracyclines. Making spatial casts from PMMA or other resin embedded samples is an important use of this material. Correlation with other imaging means, including microradiography and microtomography is important. Shipping wet bone samples between labs is best done in glycerol. Environmental SEM (ESEM, controlled vacuum mode) is valuable in eliminating -"charging" problems which are common with complex, cancellous bone samples.

  2. Tissue engineering rib with the incorporation of biodegradable polymer cage and BMSCs/decalcified bone: an experimental study in a canine model.

    Science.gov (United States)

    Tang, Hua; Wu, Bin; Qin, Xiong; Zhang, Lu; Kretlow, Jim; Xu, Zhifei

    2013-05-20

    The reconstruction of large bone defects, including rib defects, remains a challenge for surgeons. In this study, we used biodegradable polydioxanone (PDO) cages to tissue engineer ribs for the reconstruction of 4cm-long costal defects. PDO sutures were used to weave 6cm long and 1cm diameter cages. Demineralized bone matrix (DBM) which is a xenograft was molded into cuboids and seeded with second passage bone marrow mesenchymal stem cells (BMSCs) that had been osteogenically induced. Two DBM cuboids seeded with BMSCs were put into the PDO cage and used to reconstruct the costal defects. Radiographic examination including 3D reconstruction, histologic examination and mechanical test was performed after 24 postoperative weeks. All the experimental subjects survived. In all groups, the PDO cage had completely degraded after 24 weeks and been replaced by fibrous tissue. Better shape and radian were achieved in PDO cages filled with DBM and BMSCs than in the other two groups (cages alone, or cages filled with acellular DBM cuboids). When the repaired ribs were subjected to an outer force, the ribs in the PDO cage/DBMs/BMSCs group kept their original shape while ribs in the other two groups deformed. In the PDO cage/DBMs/BMSCs groups, we also observed bony union at all the construct interfaces while there was no bony union observed in the other two groups. This result was also confirmed by radiographic and histologic examination. This study demonstrates that biodegradable PDO cage in combination with two short BMSCs/DBM cuboids can repair large rib defects. The satisfactory repair rate suggests that this might be a feasible approach for large bone repair.

  3. Analyzing the cellular contribution of bone marrow to fracture healing using bone marrow transplantation in mice

    International Nuclear Information System (INIS)

    Colnot, C.; Huang, S.; Helms, J.

    2006-01-01

    The bone marrow is believed to play important roles during fracture healing such as providing progenitor cells for inflammation, matrix remodeling, and cartilage and bone formation. Given the complex nature of bone repair, it remains difficult to distinguish the contributions of various cell types. Here we describe a mouse model based on bone marrow transplantation and genetic labeling to track cells originating from bone marrow during fracture healing. Following lethal irradiation and engraftment of bone marrow expressing the LacZ transgene constitutively, wild type mice underwent tibial fracture. Donor bone marrow-derived cells, which originated from the hematopoietic compartment, did not participate in the chondrogenic and osteogenic lineages during fracture healing. Instead, the donor bone marrow contributed to inflammatory and bone resorbing cells. This model can be exploited in the future to investigate the role of inflammation and matrix remodeling during bone repair, independent from osteogenesis and chondrogenesis

  4. Dynamic measurement of the optical properties of bovine enamel demineralization models using four-dimensional optical coherence tomography

    Science.gov (United States)

    Aden, Abdirahman; Anthony, Arthi; Brigi, Carel; Merchant, Muhammad Sabih; Siraj, Huda; Tomlins, Peter H.

    2017-07-01

    Dental enamel mineral loss is multifactorial and is consequently explored using a variety of in vitro models. Important factors include the presence of acidic pH and its specific ionic composition, which can both influence lesion characteristics. Optical coherence tomography (OCT) has been demonstrated as a promising tool for studying dental enamel demineralization. However, OCT-based characterization and comparison of demineralization model dynamics are challenging without a consistent experimental environment. Therefore, an automated four-dimensional OCT system was integrated with a multispecimen flow cell to measure and compare the optical properties of subsurface enamel demineralization in different models. This configuration was entirely automated, thus mitigating any need to disturb the specimens and ensuring spatial registration of OCT image volumes at multiple time points. Twelve bovine enamel disks were divided equally among three model groups. The model demineralization solutions were citric acid (pH 3.8), acetic acid (pH 4.0), and acetic acid with added calcium and phosphate (pH 4.4). Bovine specimens were exposed to the solution continuously for 48 h. Three-dimensional OCT data were obtained automatically from each specimen at a minimum of 1-h intervals from the same location within each specimen. Lesion dynamics were measured in terms of the depth below the surface to which the lesion extended and the attenuation coefficient. The net loss of surface enamel was also measured for comparison. Similarities between the dynamics of each model were observed, although there were also distinct characteristic differences. Notably, the attenuation coefficients showed a systematic offset and temporal shift with respect to the different models. Furthermore, the lesion depth curves displayed a discontinuous increase several hours after the initial acid challenge. This work demonstrated the capability of OCT to distinguish between different enamel demineralization

  5. Demineralized water flow cancelling experiments with ice plug into high diameter horizontal tube (300 nominal diameter)

    International Nuclear Information System (INIS)

    Gyongyosi, T.; Valeca, S.; Corbescu, B.; Puiu, D.; Panaitescu, V. N.

    2015-01-01

    The isolation with ice plug of a high diameter horizontal pipeline section is a specific technique for repairs activities/ replacements of components owning to thermo-hydraulic installations working with liquid agents. The application of such technique don.t assumes stopping of the entire system. The ice plugging inside of the pipeline assumes using of a special device and of an own specific technology for application. The paper contains a brief description of the experimental technological facilities used, followed by setting off the main moments in evolution of two experimental tests carried out on the test section with 300 mm nominal diameter for demineralized water and, finally, by a brief results analysis and some conclusions. The paper is dedicated to the specialists working in the research and technological engineering. (authors)

  6. Bone scintigraphy in chondroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Humphry, A.; Gilday, D.L.; Brown, R.G.

    1980-11-01

    Scintigraphy in 3 patients with chondroblastoma showed that the tumors were hyperemic and avidly accumulated the radionuclide. These changes were also present in adjacent normal bone, but to a lesser degree. This suggests that radionuclide uptake in chondroblastoma is a function of the blood supply to the tumor rather than primary matrix extraction.

  7. Novel Dental Cement to Combat Biofilms and Reduce Acids for Orthodontic Applications to Avoid Enamel Demineralization

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2016-05-01

    Full Text Available Orthodontic treatments often lead to biofilm buildup and white spot lesions due to enamel demineralization. The objectives of this study were to develop a novel bioactive orthodontic cement to prevent white spot lesions, and to determine the effects of cement compositions on biofilm growth and acid production. 2-methacryloyloxyethyl phosphorylcholine (MPC, nanoparticles of silver (NAg, and dimethylaminohexadecyl methacrylate (DMAHDM were incorporated into a resin-modified glass ionomer cement (RMGI. Enamel shear bond strength (SBS was determined. Protein adsorption was determined using a micro bicinchoninic acid method. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU and lactic acid production. Incorporating 3% of MPC, 1.5% of DMAHDM, and 0.1% of NAg into RMGI, and immersing in distilled water at 37 °C for 30 days, did not decrease the SBS, compared to control (p > 0.1. RMGI with 3% MPC + 1.5% DMAHDM + 0.1% NAg had protein amount that was 1/10 that of control. RMGI with triple agents (MPC + DMAHDM + NAg had much stronger antibacterial property than using a single agent or double agents (p < 0.05. Biofilm CFU on RMGI with triple agents was reduced by more than 3 orders of magnitude, compared to commercial control. Biofilm metabolic activity and acid production were also greatly reduced. In conclusion, adding MPC + DMAHDM + NAg in RMGI substantially inhibited biofilm viability and acid production, without compromising the orthodontic bracket bond strength to enamel. The novel bioactive cement is promising for orthodontic applications to hinder biofilms and plaque buildup and enamel demineralization.

  8. Degradation of the organic phase of bone by osteoclasts

    DEFF Research Database (Denmark)

    Henriksen, Kim; Sørensen, Mette G; Nielsen, Rasmus H

    2006-01-01

    Osteoclasts degrade bone matrix by secretion of hydrochloric acid and proteases. We studied the processes involved in the degradation of the organic matrix of bone in detail and found that lysosomal acidification is involved in this process and that MMPs are capable of degrading the organic matrix...

  9. Matrix calculus

    CERN Document Server

    Bodewig, E

    1959-01-01

    Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well

  10. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  11. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  12. Synthetic matrix metalloproteinase inhibitors inhibit growth of established breast cancer osteolytic lesions and prolong survival in mice

    DEFF Research Database (Denmark)

    Winding, Bent; NicAmhlaoibh, Róisín; Misander, Henriette

    2002-01-01

    Breast cancer frequently leads to incurable bone metastasis. Essential requirements for the development of bone metastasis are cell-cell and cell-matrix interactions, release of bioactive growth factors and cytokines, and removal of large amounts of bone matrix. Matrix metalloproteinases (MMPs...

  13. Bone mineral changes in primary hyperparathyroidism

    International Nuclear Information System (INIS)

    Richardson, M.L.; Harborview Medical Center, Seattle, WA; Pozzi-Mucelli, R.S.; Trieste Univ.; Kanter, A.S.; Genant, H.K.; Kolb, F.O.; Ettinger, B.

    1986-01-01

    We studied 34 patients with primary hyperparathyroidism in order to assess their bone mineral status, to determine its relationship to biochemical parameters (serum calcium and parathyroid hormone) and surgical status, and to determine the relationship between peripheral cortical bone and spinal trabecular bone in this disease. These patients were studied with radiogrammetry of the metacarpals, Norland-Cameron photon absorptiometry of the radius, quantitative computed tomography (QCT) of the spine, industrial radiography of the hands, and conventional radiography of the thoracolumbar spine. We also calculated a spinal fracture index from thoracolumbar spine films. We found that the appendicular measurements correlated well together, but less well with spinal QCT. The spinal fracture index correlated best with QCT (r = 0.55), although significant dispersion was noted. We found that, in general, these hyperparathyroid patients had statistically significant decrements in bone mineral content in both the appendicular and the axial portions of the skeleton. However, the decrement in the appendicular skeleton did not correlate well with that in the axial skeleton. Therefore we conclude that it is necessary to measure both peripheral and central bone mineral content in order to reliably assess the skeletal demineralizing effects of primary hyperparathyroidism in an individual patient. (orig.)

  14. Cell based bone tissue engineering in jaw defects

    NARCIS (Netherlands)

    Meijer, Gert J.; de Bruijn, Joost Dick; Koole, Ron; van Blitterswijk, Clemens

    2008-01-01

    In 6 patients the potency of bone tissue engineering to reconstruct jaw defects was tested. After a bone marrow aspirate was taken, stem cells were cultured, expanded and grown for 7 days on a bone substitute in an osteogenic culture medium to allow formation of a layer of extracellular bone matrix.

  15. Transcutaneous Raman Spectroscopy of Bone

    Science.gov (United States)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral

  16. Effect of dentifrice containing fluoride and/or baking soda on enamel demineralization/remineralization: an in situ study.

    Science.gov (United States)

    Cury, J A; Hashizume, L N; Del Bel Cury, A A; Tabchoury, C P

    2001-01-01

    The additive effect of baking soda on the anticariogenic effect of fluoride dentifrice is not well established. To evaluate it, a crossover in situ study was done in three phases of 28 days. Volunteers, using acrylic palatal appliances containing four human enamel blocks, two sound (to evaluate demineralization) and two with artificial caries lesions (to evaluate remineralization), took part in this study. During each phase, 10% sucrose solution was dripped (3 times a day) only onto the sound blocks. After 10 min, a slurry of placebo, fluoride (F) or fluoride and baking soda (F+NaHCO(3)) dentifrice was dripped onto all enamel blocks. The results showed a higher F concentration in dental plaque formed during treatment with F+NaHCO(3) than placebo (pbaking soda neither improves nor impairs the effect of F dentifrice on reduction of demineralization and enhancement of remineralization of enamel.

  17. Electrochemical corrosion characteristics of aluminium alloy 6061 T6 in demineralized water containing 0.1 % chloride ion

    International Nuclear Information System (INIS)

    Zaifol Samsu; Muhammad Daud; Siti Radiah Mohd Kamarudin; Mohd Saari Ripin; Rusni Rejab; Mohd Shariff Sattar

    2012-01-01

    Direct current electrochemical method is one of the techniques has been used to study the corrosion behaviour of metal/alloy in its environment. This paper attempts to investigate the corrosion behaviour of Al 6061 T6 immersed in Reactor TRIGA Mark II pool water containing about 0.1% NaCl content. The result shown that the corrosion rate value of the aluminium 6061 T6 increased with the presence of 0.1 % Ion Chloride content in the demineralized water reactor pool as compared to normal demineralized water. This is due to aggressiveness of chloride ion attack to metal surface. Beside corrosion rate analysis, the further tests such as corrosion behaviour diagram, cyclic polarization have been carried and the results have been reported. (author)

  18. The efficacy of laser-assisted in-office bleaching and home bleaching on sound and demineralized enamel

    Science.gov (United States)

    Akbari, Majid; Mohammadpour, Sakineh

    2015-01-01

    Aims: This study investigated the effectiveness of laser-assisted in-office bleaching and home-bleaching in sound and demineralized enamel. Materials and Methods: The sample consisted of 120 freshly-extracted bovine incisors. Half of the specimens were stored in a demineralizing solution to induce white spot lesions. Following exposure to a tea solution for 7.5 days, the specimens were randomly assigned to 4 groups of 30 according to the type of enamel and the bleaching procedure employed. Groups 1 and 2 consisted of demineralized teeth subjected to in-office bleaching and home bleaching, whereas in groups 3 and 4, sound teeth were subjected to in-office and home bleaching, respectively. A diode laser (810 nm, 2 W, continuous wave, four times for 15 seconds each) was employed for assisting the in-office process. The color of the specimens was measured before (T1) and after (T2) staining and during (T3) and after (T4) the bleaching procedures using a spectrophotometer. The color change (ΔE) between different treatments stages was compared among the groups. Results: There were significant differences in the color change between T2 and T3 (ΔE T2–T3) and T2 and T4 (ΔE T2–T4) stages among the study groups (pbleaching (group 1) as compared to the other groups (Pbleaching could provide faster and greater whitening effect than home bleaching on stained demineralized enamel, but both procedures produced comparable results on sound teeth. PMID:26877590

  19. Does ozone enhance the remineralizing potential of nanohydroxyapatite on artificially demineralized enamel? A laser induced fluorescence study

    Science.gov (United States)

    Srinivasan, Samuelraj; Prabhu, Vijendra; Chandra, Subhash; Koshy, Shalini; Acharya, Shashidhar; Mahato, Krishna K.

    2014-02-01

    The present era of minimal invasive dentistry emphasizes the early detection and remineralization of initial enamel caries. Ozone has been shown to reverse the initial demineralization before the integrity of the enamel surface is lost. Nano-hydroxyapatite is a proven remineralizing agent for early enamel caries. In the present study, the effect of ozone in enhancing the remineralizing potential of nano-hydroxyapatite on artificially demineralized enamel was investigated using laser induced fluorescence. Thirty five sound human premolars were collected from healthy subjects undergoing orthodontic treatment. Fluorescence was recorded by exciting the mesial surfaces using 325 nm He-Cd laser with 2 mW power. Tooth specimens were subjected to demineralization to create initial enamel caries. Following which the specimens were divided into three groups, i.e ozone (ozonated water for 2 min), without ozone and artificial saliva. Remineralization regimen was followed for 3 weeks. The fluorescence spectra of the specimens were recorded from all the three experimental groups at baseline, after demineralization and remineralization. The average spectrum for each experimental group was used for statistical analysis. Fluorescence intensities of Ozone treated specimens following remineralization were higher than that of artificial saliva, and this difference was found to be statistically significant (P<0.0001). In a nutshell, ozone enhanced the remineralizing potential of nanohydroxyapatite, and laser induced fluorescence was found to be effective in assessing the surface mineral changes in enamel. Ozone can be considered an effective agent in reversing the initial enamel caries there by preventing the tooth from entering into the repetitive restorative cycle.

  20. A biomimetic approach toward artificial bone-like materials

    OpenAIRE

    Bertozzi, Carolyn R.

    2001-01-01

    Bone consists of microcrystalline hydroxyapatite and collagen, an elastic protein matrix that is decorated with mineral-nucleating phosphoproteins. Our rational design of artificial bone-like material uses natural bone as a guide. Hydrogel and self-assembling polymers that possess anionic groups suitably positioned for nucleating biominerals, and therefore mimic the natural function of the collagen-phosphoprotein matrix in bone, were designed to direct template-driven biomimetic mineralizatio...

  1. Lyophilized allogeneic bone grafts for cystic and discontinuity defects of the jaws

    International Nuclear Information System (INIS)

    Pill Hoon Choung; Eun Seok Kim

    1999-01-01

    Allogenic bone grafts have been used after various processing in each institute was made by lyophilized allogenic bone and used for maxillofacial reconstruction. Three types of lyophilized allogenic bone grafts as powder, chip and block form were performed to reconstruct the following defects: 1) maxillectomy, 2) mandiblectomy, 3) cystectomy, 4) cleft alveolus, 5) gap in orthognathic osteotomy, 6) peri-implant defect, 7) extraction socket, and 8) facial contouring. Above defects can be classified as cystic and discontinuity defects of the maxilia and the mandible. Because discontinuity defects have more difficult problems to reconstruct considering mechanical strength of the allogenic bone. We performed allogenic bone grafts on 50 cystic defects and 12 discontinuity defects of the jaws. Among them, 3 cases were removed due to infection, and the others had no complications. In reconstruction of cystic defects, the defects were filled with allogenic chip which were made from allogenic block bone at the surgery, which later were changed to host bone. Three cases of them showed tooth eruption through the allogenic bone grafting site, changing the eruption pathway, which was interrupted by the lesion. in reconstruction of discontinuity defects, usually allogenic bone has been used as a tray, in which PMCB or demineralized bone chips were filled. But we tried to reconstruct this discontinuity defect using allogeneic bone block without inside filling of PMCB different from tray type. We will present the results of allogenic bone grafts using cranial bone, costochondral graft, and the mandible

  2. Comparative investigation of viability, metabolism and osteogenic capability of tissue-engineered bone preserved in sealed osteogenic media at 37 0C and 4 0C

    International Nuclear Information System (INIS)

    Wang Hengjian; Liu Guangpeng; Zhou Guangdong; Cen Lian; Cui Lei; Cao Yilin

    2010-01-01

    Preservation of tissue-engineered (TE) bone is one of the key problems needed to be solved for its clinic application and industrialization. Traditional cryopreservation has been restricted because of the damages caused by ice formation and solution. Hypothermic preservation at 4 0 C has been widely used for the preservation of transplanted organ despite potential negative effects on viability of cells and tissue. 37 0 C is the best temperature for maintaining cellular bioactivities. However, 37 0 C also has a potential negative effect on preserved cells due to consumption of nutrients and accumulation of by-products. No studies have reported which temperature is more suitable for the preservation of TE bone constructs. The current study explored the feasibility of preservation of TE bone constructs in sealed osteogenic media at 37 0 C and 4 0 C. Human bone marrow stromal cells (hBMSCs) were seeded into partially demineralized bone matrix (pDBM) scaffolds and cultured for 7 days to form TE bone constructs. The constructs were preserved in sealed osteogenic media at either 37 0 C or 4 0 C for 5, 7, 9 and 11 days, respectively. Growth kinetics, viability, metabolism and osteogenic capability were evaluated to explore the feasibility of preservation at 37 0 C and 4 0 C. The constructs cultured in osteogenic media at humidified 37 0 C/5%CO 2 served as the positive control. The results demonstrated that all the constructs preserved at 4 0 C showed negative osteogenic capability at all time points with a much lower level of growth kinetics, viability and metabolism compared to the positive control. However, the constructs preserved at 37 0 C showed good osteogenic capability within 7 days with a certain level of growth kinetics, viability and metabolism, although an obvious decrease in osteogenic capability was observed in the constructs preserved at 37 0 C over 9 days. These results indicate that the preservation of TE bone constructs is feasible at 37 0 C within 7 days

  3. Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm – caries model

    Directory of Open Access Journals (Sweden)

    Juliana Nunes BOTELHO

    2016-01-01

    Full Text Available Abstract Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day to one of the following treatments: 0.9% NaCl (negative control, 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose. To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day the culture medium pH. After 4 (dentine or 5 (enamel days of growth, biofilms (n = 9 were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001 on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

  4. Selective Acid Etching Improves the Bond Strength of Universal Adhesive to Sound and Demineralized Enamel of Primary Teeth.

    Science.gov (United States)

    Antoniazzi, Bruna Feltrin; Nicoloso, Gabriel Ferreira; Lenzi, Tathiane Larissa; Soares, Fabio Zovico Maxnuck; Rocha, Rachel de Oliveira

    To evaluate the influence of enamel condition and etching strategy on bond strength of a universal adhesive in primary teeth. Thirty-six primary molars were randomly assigned to six groups (n = 6) according to the enamel condition (sound [S] and demineralized [DEM]/cariogenic challenge by pH cycling prior to restorative procedures) and adhesive system (Scotchbond Universal Adhesive [SBU]) used in either etch-and-rinse (ER) or selfetching (SE) mode, with Clearfil SE Bond as the self-etching control. The adhesives were applied to flat enamel surfaces and composite cylinders (0.72 mm2) were built up. After 24-h storage in water, specimens were subjected to the microshear test. Bond strength (MPa) data were analyzed using two-way ANOVA and Tukey's post-hoc tests (α = 0.05). Significant differences were found considering the factors adhesive system (p = 0.003) and enamel condition (p = 0.001). Demineralized enamel negatively affected the bond strength, with μSBS values approximately 50% lower than those obtained for sound enamel. SBU performed better in etch-and-rinse mode, and the bond strength found for SBU applied in self-etching mode was similar to that of CSE. Enamel etching with phosphoric acid improves the bond strength of a universal adhesive system to primary enamel. Demineralized primary enamel results in lower bond strength.

  5. Bone markers during acute burn care: Relevance to clinical practice?

    Science.gov (United States)

    Rousseau, Anne-Françoise; Damas, Pierre; Delanaye, Pierre; Cavalier, Etienne

    2017-02-01

    Bone changes are increasingly described after burn. How bone markers could help to detect early bone changes or to screen burn patients at higher risk of demineralization is still not made clear. We performed an observational study assessing the changes in serum bone markers after moderate burn. Adults admitted in the first 24h following burn extended on >10% body surface area were included. Serum levels of collagen type 1 cross-linked C-telopeptide (CTX), tartrate-resistant acid phosphatase 5b (TRAP), type 1 procollagen N-terminal (P1NP) and bone alkaline phosphatase (b-ALP) were measured at admission and every week during the first month. Data are expressed as median [min-max]. Bone markers were measured in 20 patients: 18 men, 2 women (including one post-menopausal). Age was 46 [19-86] years old, burn surface area reached 15 [7-85] %. Twelve patients completed the study. All biomarkers mainly remained into normal ranges during evolution. A huge variability was observed regarding biomarkers evolution. Patient's evolution was not linear and could fluctuate from a decrease to an increase of blood concentrations. There was not necessarily a consistency between the two formation or the two resorption markers. Variations observed between two consecutive measurements were lesser than the accepted critical difference in almost one third of the cases. Considering available data, role and interest of bone markers in management of burn related bone disease remain unclear. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  6. [In vivo retention of KOH soluble and firmly bound fluoride in demineralized dental enamel].

    Science.gov (United States)

    Hellwig, E; Klimek, J; Albert, G

    1989-03-01

    Cylindrical enamel blocks with initial carious lesions were treated for one hour with Duraphat or Fluor-Protector. After removal of the fluoride varnishes the enamel blocks were kept in the mouths of 3 probands for 5 days. Plaque was allowed to accumulate on half of the enamel cylinders, while the other half was kept clean. Part of the enamel cylinders were retained as fluoridated controls. Compared with Duraphat the application of Fluor-Protector resulted in a significantly higher uptake of KOH soluble and firmly bound fluoride. During the 5 days of the experiment the amount of KOH soluble fluorides decreased in both groups. In the presence of plaque the fluoride loss was higher. The amount of firmly bound fluoride increased both in the plaque covered and in the clean enamel. The durable cariostatic effect of fluoridated varnishes seems to be due to the slow dissolution of Ca F2-like precipitates on the enamel surface and the concomitant fluoride uptake in the underlying demineralized enamel.

  7. Effect of Violet-Blue Light on Streptococcus mutans-Induced Enamel Demineralization

    Directory of Open Access Journals (Sweden)

    Grace Gomez Felix Gomez

    2018-03-01

    Full Text Available Background: This in vitro study determined the effectiveness of violet-blue light (405 nm on inhibiting Streptococcus mutans-induced enamel demineralization. Materials and Methods: S. mutans UA159 biofilm was grown on human enamel specimens for 13 h in 5% CO2 at 37 °C with/without 1% sucrose. Wet biofilm was treated twice daily with violet-blue light for five minutes over five days. A six-hour reincubation was included daily between treatments excluding the final day. Biofilms were harvested and colony forming units (CFU were quantitated. Lesion depth (L and mineral loss (∆Z were quantified using transverse microradiography (TMR. Quantitative light-induced fluorescence Biluminator (QLF-D was used to determine mean fluorescence loss. Data were analyzed using one-way analysis of variance (ANOVA to compare differences in means. Results: The results demonstrated a significant reduction in CFUs between treated and non-treated groups grown with/without 1% sucrose. ∆Z was significantly reduced for specimens exposed to biofilms grown without sucrose with violet-blue light. There was only a trend on reduction of ∆Z with sucrose and with L on both groups. There were no differences in fluorescence-derived parameters between the groups. Conclusions: Within the limitations of the study, the results indicate that violet-blue light can serve as an adjunct prophylactic treatment for reducing S. mutans biofilm formation and enamel mineral loss.

  8. Condensate demineralizer system fo