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Sample records for bone substitute material

  1. Development of a piezoelectric bone substitute material

    CERN Document Server

    Al-Bader, Y A

    2000-01-01

    The thesis deals with the preparation and testing of ceramic compositions to be used as bone substitute. The proposed composition consisted of calcium enriched calcium phosphate, kaolin and barium titanate in different ratios. The homogeneous powder mixture was dry pressed at different pressures and fired at temperatures up to 1350 degC for different soaking times. The physical properties of the fired compacts that were tested are bulk density and porosity. These were determined as function of pressing pressure, firing temperature and soaking time for different compositions. The mechanical properties investigated were the ultimate compressive strength and Young's modulus, which were determined for different compositions and forming pressures. The electrical properties investigated were D.C. characteristics (resistivity) and A.C. characteristics (A.C. resistivity, dielectric constant, dielectric loss and loss tangent). The piezoelectric behaviour of the fired compacts was investigated and the piezoelectric coe...

  2. Tissue reaction and material characteristics of four bone substitutes

    DEFF Research Database (Denmark)

    Jensen, S S; Aaboe, M; Pinholt, E M;

    1996-01-01

    The aim of the present study was to qualitatively and quantitatively compare the tissue reactions around four different bone substitutes used in orthopedic and craniofacial surgery. Cylinders of two bovine bone substitutes (Endobon and Bio-Oss) and two coral-derived bone substitutes (Pro Osteon 5...

  3. Development of bioactive materials using reticulated ceramics for bone substitute

    Science.gov (United States)

    Jiang, Gengwei

    For hard tissue prosthetics, it is necessary to seek novel synthesis routes by which a real structural bone can be simulated in terms of bioactivity, porosity, and mechanical behavior. The work presented here deals with the development of such a component by a novel synthesis route for bone implantation. To enhance the mechanical properties, an industrial alumina has been selected as the substrate. Alumina is not only bio inert but also mechanically strong which makes it an ideal substrate for bone substitute. The high porosity is achieved via a sponge technique by which both pore size and density can be changed easily. The bioactivity is induced by coating a highly bioactive HA film onto the inner pore surfaces of the reticulated alumina. Based on this concept, the research has focused on the coating of HA onto inner pore surfaces of the reticulated alumina via several effective methods that are developed in our laboratory. No previous studies have so far been reported on coating inner surfaces of small-diameter pores ranging from 0.1--1.0 mm. The key materials processing issues dealt with in this work include precursor chemistry, coating procedures, synthesis of coated component, interface structure study, film adhesion strength testing, and mechanical properties of the component. This novel approach has shown great promise in synthesizing bone substitutes. To determine the applicability of the coated component in hard tissue prosthetics, a bioactivity study has been carried out. By immersing the synthetic HA into simulated body fluid (SBF), the bioresponse has been measured for a variety of samples with different processing conditions. Fundamental aspects of this study are centered on the effects of structural characteristics of HA on the bioactivity. Based on extensive IR and XRD experimental data, it has been found that the bioactivity of HA is sensitively controlled by the structural crystallinity of the HA and its specific surface area. Furthermore, based on

  4. Current trends and future perspectives of bone substitute materials - from space holders to innovative biomaterials.

    Science.gov (United States)

    Kolk, Andreas; Handschel, Jörg; Drescher, Wolf; Rothamel, Daniel; Kloss, Frank; Blessmann, Marco; Heiland, Max; Wolff, Klaus-Dietrich; Smeets, Ralf

    2012-12-01

    An autologous bone graft is still the ideal material for the repair of craniofacial defects, but its availability is limited and harvesting can be associated with complications. Bone replacement materials as an alternative have a long history of success. With increasing technological advances the spectrum of grafting materials has broadened to allografts, xenografts, and synthetic materials, providing material specific advantages. A large number of bone-graft substitutes are available including allograft bone preparations such as demineralized bone matrix and calcium-based materials. More and more replacement materials consist of one or more components: an osteoconductive matrix, which supports the ingrowth of new bone; and osteoinductive proteins, which sustain mitogenesis of undifferentiated cells; and osteogenic cells (osteoblasts or osteoblast precursors), which are capable of forming bone in the proper environment. All substitutes can either replace autologous bone or expand an existing amount of autologous bone graft. Because an understanding of the properties of each material enables individual treatment concepts this review presents an overview of the principles of bone replacement, the types of graft materials available, and considers future perspectives. Bone substitutes are undergoing a change from a simple replacement material to an individually created composite biomaterial with osteoinductive properties to enable enhanced defect bridging.

  5. Mineralized polymer composites as biogenic bone substitute material

    Science.gov (United States)

    Shah, Rushita; Saha, Nabanita; Kitano, Takeshi; Saha, Petr

    2015-05-01

    Mineralized polymer composites (MPC) are recognized as potential fillers of bone defects. Though bioceramics exhibits quite a good bone-bonding and vascularization, it is considered to be too stiff and brittle for using alone. Thus, the use of polymer scaffold instead of bioceramics has several advantages including combining the osteoconductivity and bone-bonding potential of the inorganic phase with the porosity and interconnectivity of the three-dimensional construction. Aiming the advantages of ceramic-polymer composite scaffolds, the calcium carbonate (CaCO3) based biomineralized scaffold was prepared, where the PVP-CMC hydrogel was used as an extracellular matrix. This paper is reported about the morphology, swelling trend (in physiological solution) and viscoelastic behavior of (90 min mineralized) MPC. The dry MPC are off-white, coarse in texture, comparatively less flexible than the original PVP-CMC based hydrogel film, and the deposition of granular structures on the surface of the hydrogel film confirms about the development of biomineralized scaffold/polymer composites. Irrespective of thickness, the dry MPC shows higher values of swelling ratio within 30 min, which varies between 200-250 approximately. The dynamic viscoelastic nature of freshly prepared MPC was investigated applying 1% and 10% strain. At higher strain the viscoelastic moduli (G' and G") show significant change, and the nature of MPC turns from elastic to viscous. Based on the observed basic properties, the MPC (calcite based polymer composites) can be recommended for the treatment of adyanamic bone disorder.

  6. Biocompatible glass-ceramic materials for bone substitution.

    Science.gov (United States)

    Vitale-Brovarone, Chiara; Verné, Enrica; Robiglio, Lorenza; Martinasso, Germana; Canuto, Rosa A; Muzio, Giuliana

    2008-01-01

    A new bioactive glass composition (CEL2) in the SiO(2)-P(2)O(5)-CaO-MgO-K(2)O-Na(2)O system was tailored to control pH variations due to ion leaching phenomena when the glass is in contact with physiological fluids. CEL2 was prepared by a traditional melting-quenching process obtaining slices that were heat-treated to obtain a glass-ceramic material (CEL2GC) that was characterized thorough SEM analysis. Pre-treatment of CEL2GC with SBF was found to enhance its biocompatibility, as assessed by in vitro tests. CEL2 powder was then used to synthesize macroporous glass-ceramic scaffolds. To this end, CEL2 powders were mixed with polyethylene particles within the 300-600 microm size-range and then pressed to obtain crack-free compacted powders (green). This was heat-treated to remove the organic phase and to sinter the inorganic phase, leaving a porous structure. The biomaterial thus obtained was characterized by X-ray diffraction, SEM equipped with EDS, density measurement, image analysis, mechanical testing and in vitro evaluation, and found to be a glass-ceramic macroporous scaffold with uniformly distributed and highly interconnected porosity. The extent and size-range of the porosity can be tailored by varying the amount and size of the polyethylene particles.

  7. A perfusion bioreactor system efficiently generates cell‐loaded bone substitute materials for addressing critical size bone defects

    Science.gov (United States)

    Kleinhans, Claudia; Mohan, Ramkumar Ramani; Vacun, Gabriele; Schwarz, Thomas; Haller, Barbara; Sun, Yang; Kahlig, Alexander; Kluger, Petra; Finne‐Wistrand, Anna; Walles, Heike

    2015-01-01

    Abstract Critical size bone defects and non‐union fractions are still challenging to treat. Cell‐loaded bone substitutes have shown improved bone ingrowth and bone formation. However, a lack of methods for homogenously colonizing scaffolds limits the maximum volume of bone grafts. Additionally, therapy robustness is impaired by heterogeneous cell populations after graft generation. Our aim was to establish a technology for generating grafts with a size of 10.5 mm in diameter and 25 mm of height, and thus for grafts suited for treatment of critical size bone defects. Therefore, a novel tailor‐made bioreactor system was developed, allowing standardized flow conditions in a porous poly(L‐lactide‐co‐caprolactone) material. Scaffolds were seeded with primary human mesenchymal stem cells derived from four different donors. In contrast to static experimental conditions, homogenous cell distributions were accomplished under dynamic culture. Additionally, culture in the bioreactor system allowed the induction of osteogenic lineage commitment after one week of culture without addition of soluble factors. This was demonstrated by quantitative analysis of calcification and gene expression markers related to osteogenic lineage. In conclusion, the novel bioreactor technology allows efficient and standardized conditions for generating bone substitutes that are suitable for the treatment of critical size defects in humans. PMID:26011163

  8. A perfusion bioreactor system efficiently generates cell-loaded bone substitute materials for addressing critical size bone defects.

    Science.gov (United States)

    Kleinhans, Claudia; Mohan, Ramkumar Ramani; Vacun, Gabriele; Schwarz, Thomas; Haller, Barbara; Sun, Yang; Kahlig, Alexander; Kluger, Petra; Finne-Wistrand, Anna; Walles, Heike; Hansmann, Jan

    2015-09-01

    Critical size bone defects and non-union fractions are still challenging to treat. Cell-loaded bone substitutes have shown improved bone ingrowth and bone formation. However, a lack of methods for homogenously colonizing scaffolds limits the maximum volume of bone grafts. Additionally, therapy robustness is impaired by heterogeneous cell populations after graft generation. Our aim was to establish a technology for generating grafts with a size of 10.5 mm in diameter and 25 mm of height, and thus for grafts suited for treatment of critical size bone defects. Therefore, a novel tailor-made bioreactor system was developed, allowing standardized flow conditions in a porous poly(L-lactide-co-caprolactone) material. Scaffolds were seeded with primary human mesenchymal stem cells derived from four different donors. In contrast to static experimental conditions, homogenous cell distributions were accomplished under dynamic culture. Additionally, culture in the bioreactor system allowed the induction of osteogenic lineage commitment after one week of culture without addition of soluble factors. This was demonstrated by quantitative analysis of calcification and gene expression markers related to osteogenic lineage. In conclusion, the novel bioreactor technology allows efficient and standardized conditions for generating bone substitutes that are suitable for the treatment of critical size defects in humans.

  9. Cell response of calcium phosphate based ceramics, a bone substitute material

    Directory of Open Access Journals (Sweden)

    Juliana Marchi

    2013-01-01

    Full Text Available The aim of this study was to characterize calcium phosphate ceramics with different Ca/P ratios and evaluate cell response of these materials for use as a bone substitute. Bioceramics consisting of mixtures of hydroxyapatite (HAp and β-tricalcium phosphate (β-TCP powders in different proportions were pressed and sintered. The physical and chemical properties of these bioceramics were then characterized. Characterization of the biological properties of these materials was based on analysis of cell response using cultured fibroblasts. The number of cells attached to the samples was counted from SEM images of samples exposed to cell culture solution for different periods. These data were compared by analysis of variance (ANOVA complemented by the Tukey's test. The TCP sample had higher surface roughness and lower density. The adherence and growth of FMM1 cells on samples from all groups was studied. Even though the different calcium based ceramics exhibited properties which made them suitable as bone substitutes, those with higher levels of β-TCP revealed improved cell growth on their surfaces. These observations indicated two-phase calcium phosphate based materials with a β-TCP surface layer to be a promising bone substitute.

  10. Design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite as a potential bone graft substitute material

    Science.gov (United States)

    Florschutz, Anthony Vatroslav

    Utilization of bone grafts for the treatment of skeletal pathology is a common practice in orthopaedic, craniomaxillofacial, dental, and plastic surgery. Autogenous bone graft is the established archetype but has disadvantages including donor site morbidity, limited supply, and prolonging operative time. In order to avoid these and other issues, bone graft substitute materials are becoming increasingly prevalent among surgeons for reconstructing skeletal defects and arthrodesis applications. Bone graft substitutes are biomaterials, biologics, and guided tissue/bone regenerative devices that can be used alone or in combinations as supplements or alternatives to autogenous bone graft. There is a growing interest and trend to specialize graft substitutes for specific indications and although there is good rationale for this indication-specific approach, the development and utility of a more universal bone graft substitute may provide a better answer for patients and surgeons. The aim of the present research focuses on the design, synthesis, and initial evaluation of D-glyceraldehyde crosslinked gelatin-hydroxyapatite composites for potential use as a bone graft substitutes. After initial establishment of rational material design, gelatinhydroxyapatite scaffolds were fabricated with different gelatin:hydroxyapatite ratios and crosslinking concentrations. The synthesized scaffolds were subsequently evaluated on the basis of their swelling behavior, porosity, density, percent composition, mechanical properties, and morphology and further assessed with respect to cell-biomaterial interaction and biomineralization in vitro. Although none of the materials achieved mechanical properties suitable for structural graft applications, a reproducible material design and synthesis was achieved with properties recognized to facilitate bone formation. Select scaffold formulations as well as a subset of scaffolds loaded with recombinant human bone morphogenetic protein-2 were

  11. Tissue reaction and material biodegradation of a calcium sulfate/apatite biphasic bone substitute in rat muscle

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    Jian-Sheng Wang

    2016-07-01

    Conclusion: Calcium sulfate hydroxyapatite bone substitute can be used as a carrier for antibiotics or other drugs, without adverse reaction due to the fast resorption of the calcium sulfate. No bone formation was seen despite treating the bone substitute with autologous bone marrow.

  12. Development of multi-substituted hydroxyapatite nanopowders as biomedical materials for bone tissue engineering applications.

    Science.gov (United States)

    Baba Ismail, Yanny M; Wimpenny, Ian; Bretcanu, Oana; Dalgarno, Kenneth; El Haj, Alicia J

    2017-02-15

    Ionic substitutions have been proposed as a tool to control the functional behavior of synthetic hydroxyapatite (HA), particularly for Bone Tissue Engineering (BTE) applications. The effect of simultaneous substitution of different levels of carbonate (CO3 ) and silicon (Si) ions in the HA lattice was investigated. Furthermore, human bone marrow-derived mesenchymal stem cells (hMSCs) were cultured on multi-substituted HA (SiCHA) to determine if biomimetic chemical compositions were osteoconductive. Of the four different compositions investigates, SiCHA-1 (0.58wt% Si) and SiCHA-2 (0.45wt% Si) showed missing bands for CO3 and Si using FTIR analysis, indicating competition for occupation of the phosphate site in the HA lattice. 500°C was considered the most favourable calcination temperature as: (i) the powders produced possessed a similar amount of CO3 (2-8wt%) and Si (<1.0wt%) as present in native bone; and (ii) there was a minimal loss of CO3 and Si from the HA structure to the surroundings during calcination. Higher Si content in SiCHA-1 led to lower cell viability and at most hindered proliferation, but no toxicity effect occurred. While, lower Si content in SiCHA-2 showed the highest ALP/DNA ratio after 21 days culture with hMSCs, indicating that the powder may stimulate osteogenic behaviour to a greater extent than other powders. This article is protected by copyright. All rights reserved.

  13. In vitro degradation and cell response of calcium carbonate composite ceramic in comparison with other synthetic bone substitute materials

    Energy Technology Data Exchange (ETDEWEB)

    He, Fupo [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China); Zhang, Jing [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Yang, Fanwen; Zhu, Jixiang; Tian, Xiumei [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China); Chen, Xiaoming, E-mail: xmchenw@126.com [Department of Biomedical Engineering, School of Basic Sciences, Guangzhou Medical University, Guangzhou 510182 (China)

    2015-05-01

    The robust calcium carbonate composite ceramics (CC/PG) can be acquired by fast sintering calcium carbonate at a low temperature (650 °C) using a biocompatible, degradable phosphate-based glass (PG) as sintering agent. In the present study, the in vitro degradation and cell response of CC/PG were assessed and compared with 4 synthetic bone substitute materials, calcium carbonate ceramic (CC), PG, hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics. The degradation rates in decreasing order were as follows: PG, CC, CC/PG, β-TCP, and HA. The proliferation of rat bone mesenchymal stem cells (rMSCs) cultured on the CC/PG was comparable with that on CC and PG, but inferior to HA and β-TCP. The alkaline phosphatase (ALP) activity of rMSCs on CC/PG was lower than PG, comparable with β-TCP, but higher than HA. The rMSCs on CC/PG and PG had enhanced gene expression in specific osteogenic markers, respectively. Compared to HA and β-TCP, the rMSCs on the CC/PG expressed relatively lower level of collagen I and runt-related transcription factor 2, but showed more considerable expression of osteopontin. Although CC, PG, HA, and β-TCP possessed impressive performances in some specific aspects, they faced extant intrinsic drawbacks in either degradation rate or mechanical strength. Based on considerable compressive strength, moderate degradation rate, good cell response, and being free of obvious shortcoming, the CC/PG is promising as another choice for bone substitute materials. - Highlights: • A calcium carbonate composite ceramic (CC/PG) was acquired. • The in vitro degradation and cell response of CC/PG were compared to 4 materials. • The CC/PG showed moderate degradation rate. • The CC/PG exhibited good cell response. • The CC/PG was free of obvious drawback compared to other materials.

  14. Composite bone substitutes prepared by two methods

    Science.gov (United States)

    Lee, Hoe Y.

    A variety of ceramics and polymers exists that can be used as bone substitute materials with desirable properties such as biocompatibility and osteoconductivity. A key feature missing in these bone substitutes, or scaffolds, is the ability to bear loads. This work explored two methods for solving this problem. The first used cancellous bone taken from bovine femoral bone to create a natural scaffold through a heat treating process that eliminated the organic components and sintered the bone minerals, known as hydroxyapatite, together. The strength and Young's modulus of the natural scaffold were greatly improved after polymer infiltration with polymethylmethacrylate. Unfortunately, compression testing revealed that there was not a good interfacial bond between the mineral and polymer phases. The second method employed a freeze-casting technique to create synthetic hydroxyapatite scaffolds that have an aligned lamellar microstructure. By varying the amount of hydroxyapatite in the initial slurry mixture and the cooling rate, synthetic scaffolds with a range of porosities and strengths was produced. The highest solid loading and fastest cooling rate produced a scaffold with a strength and modulus approaching that of cortical bone. Further study is required to produce a two phase composite that is chemically bonded together for optimal performance. The synthetic scaffolds, with their tunable mechanical properties and ease of fabrication, make them a promising material for a load-bearing bone substitute.

  15. Bioactivity and degradability of hybrids nano-composites materials with great application as bone tissue substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Téllez, D.A.; Téllez-Jurado, L.; Chávez-Alcalá, J.F., E-mail: fchaveza@hotmail.com

    2014-12-05

    Highlights: • pH has an effect on the degradation process of the hybrid materials. • Weight loss depends on the change of pH during the degradation process. • Bioactivity in the materials is strongly related to calcium and pH. - Abstract: In this work, hybrids with great application as bioactive materials having different compositions based on siloxane network were prepared. In vitro bioactivity and in vitro degradability tests were carried out in the materials by soaking them into simulated body fluid (SBF) and into phosphate buffer solution (PBS) to prove their apatite-forming ability and to show their degradation process, respectively. In both in vitro tests, measurements of pH and loss weight were made to observe bioactivity and degradation processes. To prove growth of HA, the materials were characterized through X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The results showed that some samples have better bioactivity than others. It was found that the incorporation of CaO component into the network of the materials results in an increase of the apatite-forming ability in SBF. Moreover, during the degradation tests, all the samples presented weight loss, especially the ones that contain CaO.

  16. Preparation and characterization of chitosan/nano-hydroxyapatite composite used as bone substitute materials

    Institute of Scientific and Technical Information of China (English)

    Zhang Li; Li Yubao; Zhou Gang; Wu Lan; Mu Yuanhua; Yang Zheng

    2007-01-01

    Chitosan/nano-hydroxyapatite composites with different weight ratios were prepared through a co-precipitation method using Ca(OH)2, H3PO4 and chitosan as starting materials. The properties of these composites were characterized by means of TEM, IR, XRD, TGA, bum-out tests and universal matertial testing machine. The results showed that the HA synthesized here was poorly crystalline carbonated nanometer crystals and dispersed uniformly in chitosan phase and there was no phase-separation between the two phases. The addition of n-HA resulted in a decrease of decomposing temperature of chitosan. Because of the interactions between chitosan and n-HA, the mechanical properties of these composites were improved, and the maximum value of the compressive strength was measured to be about 120MPa corresponding to the chitosan/n-HA composite with a weight ratio of 30/70.

  17. Stiffness compatibility of coralline hydroxyapatite bone substitute under dynamic loading

    Institute of Scientific and Technical Information of China (English)

    REN ChaoFeng; HOU ZhenDe; ZHAO Wei

    2009-01-01

    When hydroxyapatite bone substitutes are implanted in human bodies, bone tissues will grow into their porous structure, which will reinforce their strength and stiffness. The concept of mechanical com-patibility of bone substitutes implies that their mechanical properties are similar to the bone tissues around, as if they were part of the bone. The mechanical compatibility of bone substitutes includes both static and dynamic behavior, due to the mechanical properties of bone depending on the strain rate. In this study, split Hopkinson pressure bar technique (SHPB) was employed to determine the dy-namic mechanical properties of coralline hydroxyapatite, bones with and bones without organic com-ponents, and their dynamic stress-strain curves of the three materials were obtained. The mechanical effects of collagens in bone were assessed, by comparing the difference between the Young's moduli of the three materials. As the implanted bone substitute becomes a part of bone, it can be regarded as an inclusion composite. The effective modulus of the composite was also evaluated in order to estimate its mechanical compatibility on stiffness. The evaluated result shows that the suitable porosity of HA is0.8, which is in favor of both static and dynamic stiffness compatibility.

  18. Stiffness compatibility of coralline hydroxyapatite bone substitute under dynamic loading

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    When hydroxyapatite bone substitutes are implanted in human bodies,bone tissues will grow into their porous structure,which will reinforce their strength and stiffness.The concept of mechanical com-patibility of bone substitutes implies that their mechanical properties are similar to the bone tissues around,as if they were part of the bone.The mechanical compatibility of bone substitutes includes both static and dynamic behavior,due to the mechanical properties of bone depending on the strain rate.In this study,split Hopkinson pressure bar technique(SHPB) was employed to determine the dy-namic mechanical properties of coralline hydroxyapatite,bones with and bones without organic com-ponents,and their dynamic stress-strain curves of the three materials were obtained.The mechanical effects of collagens in bone were assessed,by comparing the difference between the Young’s moduli of the three materials.As the implanted bone substitute becomes a part of bone,it can be regarded as an inclusion composite.The effective modulus of the composite was also evaluated in order to estimate its mechanical compatibility on stiffness.The evaluated result shows that the suitable porosity of HA is 0.8,which is in favor of both static and dynamic stiffness compatibility.

  19. Bone augmentation procedures in localized defects in the alveolar ridge: clinical results with different bone grafts and bone-substitute materials

    DEFF Research Database (Denmark)

    Jensen, Simon Storgård; Terheyden, Hendrik

    2009-01-01

    periods. The heterogeneity of the available data did not allow identifying one superior grafting protocol for any of the osseous defect types under investigation. However, a series of grafting materials can be considered well-documented for different indications based on this review. There is a high level......PURPOSE: The objective of this review was to evaluate the efficacy of different grafting protocols for the augmentation of localized alveolar ridge defects. MATERIALS AND METHODS: A MEDLINE search and an additional hand search of selected journals were performed to identify all levels of clinical...... evidence except expert opinions. Any publication written in English and including 10 or more patients with at least 12 months of follow-up after loading of the implants was eligible for this review. The results were categorized according to the presenting defect type: (1) dehiscence and fenestration...

  20. 3D printing of octacalcium phosphate bone substitutes

    Directory of Open Access Journals (Sweden)

    Vladimir S. Komlev

    2015-06-01

    Full Text Available Biocompatible calcium phosphate ceramic grafts are able of supporting new bone formation in appropriate environment. The major limitation of these materials usage for medical implants is the absence of accessible methods for their patient-specific fabrication. 3D printing methodology is an excellent approach to overcome the limitation supporting effective and fast fabrication of individual complex bone substitutes. Here we proposed a relatively simple route for 3D printing of octacalcium phosphates in complexly shaped structures by the combination of inkjet printing with post-treatment methodology. The printed octacalcium phosphate blocks were further implanted in the developed cranial bone defect followed by histological evaluation. The obtained result confirmed the potential of the developed octacalcium phosphates bone substitutes, which allowed 2.5-time reducing of defect’s diameter at 6.5 months in a region where native bone repair is extremely inefficient.

  1. 3D Printing of Octacalcium Phosphate Bone Substitutes.

    Science.gov (United States)

    Komlev, Vladimir S; Popov, Vladimir K; Mironov, Anton V; Fedotov, Alexander Yu; Teterina, Anastasia Yu; Smirnov, Igor V; Bozo, Ilya Y; Rybko, Vera A; Deev, Roman V

    2015-01-01

    Biocompatible calcium phosphate ceramic grafts are able of supporting new bone formation in appropriate environment. The major limitation of these materials usage for medical implants is the absence of accessible methods for their patient-specific fabrication. 3D printing methodology is an excellent approach to overcome the limitation supporting effective and fast fabrication of individual complex bone substitutes. Here, we proposed a relatively simple route for 3D printing of octacalcium phosphates (OCP) in complexly shaped structures by the combination of inkjet printing with post-treatment methodology. The printed OCP blocks were further implanted in the developed cranial bone defect followed by histological evaluation. The obtained result confirmed the potential of the developed OCP bone substitutes, which allowed 2.5-time reducing of defect's diameter at 6.5 months in a region where native bone repair is extremely inefficient.

  2. 3D Printing of Octacalcium Phosphate Bone Substitutes

    Science.gov (United States)

    Komlev, Vladimir S.; Popov, Vladimir K.; Mironov, Anton V.; Fedotov, Alexander Yu.; Teterina, Anastasia Yu.; Smirnov, Igor V.; Bozo, Ilya Y.; Rybko, Vera A.; Deev, Roman V.

    2015-01-01

    Biocompatible calcium phosphate ceramic grafts are able of supporting new bone formation in appropriate environment. The major limitation of these materials usage for medical implants is the absence of accessible methods for their patient-specific fabrication. 3D printing methodology is an excellent approach to overcome the limitation supporting effective and fast fabrication of individual complex bone substitutes. Here, we proposed a relatively simple route for 3D printing of octacalcium phosphates (OCP) in complexly shaped structures by the combination of inkjet printing with post-treatment methodology. The printed OCP blocks were further implanted in the developed cranial bone defect followed by histological evaluation. The obtained result confirmed the potential of the developed OCP bone substitutes, which allowed 2.5-time reducing of defect’s diameter at 6.5 months in a region where native bone repair is extremely inefficient. PMID:26106596

  3. Bone graft substitutes: past, present, future.

    Directory of Open Access Journals (Sweden)

    Parikh S

    2002-04-01

    Full Text Available Bone grafts are necessary to provide support, fill voids, and enhance biologic repair of skeletal defects. They are used by orthopaedic surgeons, neurosurgeons, craniofacial surgeons, and periodontists. Bone harvested from donor sites is the gold standard for this procedure. It is well documented that there are limitations and complications from the use of autograft, including the limited quantity and associated chronic donor site pain. Despite the increase in the number of procedures that require bone grafts, there has not been a single ideal bone graft substitute Scientists, surgeons, and medical companies, thus, have a tremendous responsibility to develop biologic alternatives that will enhance the functional capabilities of the bone graft substitute, and potentially reduce or eliminate the need for autograft. This article is an attempt to review the past and existing bone graft substitutes, and future directions of research. The historical data was extracted after thorough review of the literature. The data for the current concepts and future directions was compiled from the Internet, and from direct correspondence with medical companies. Since many products are undergoing clinical trials, and are yet not commercially available, their data cannot be found in literature. The main purpose of this article is to give the reader an idea about the existing market products and products likely to be available in near future.

  4. Evaluation of bone substitute materials: comparison of flat-panel based volume CT to conventional multidetector CT.

    Science.gov (United States)

    Sauerbier, Sebastian; Duttenhoefer, Fabian; Sachlos, Elefterios; Haberstroh, Jörg; Scheifele, Christian; Wrbas, Karl-Thomas; Voss, Pit Jacob; Veigel, Egle; Smedek, Jörg; Ganter, Philip; Tuna, Taskin; Gutwald, Ralf; Palmowski, Moritz

    2013-10-01

    Over the last decade tissue engineering has emerged as a key factor in bone regeneration within the field of cranio-maxillofacial surgery. Despite this in vivo analysis of tissue-engineered-constructs to monitor bone rehabilitation are difficult to conduct. Novel high-resolving flat-panel based volume CTs (fp-VCT) are increasingly used for imaging bone structures. This study compares the potential value of novel fp-VCT with conventional multidetector CT (MDCT) based on a sheep sinus floor elevation model. Calcium-hydroxyapatite reinforced collagen scaffolds were populated with autologous osteoblasts and implanted into sheep maxillary sinus. After 8, 16 and 24 weeks MDCT and fp-VCT scans were performed to investigate the volume of the augmented area; densities of cancellous and compact bone were assessed as comparative values. fp-VCT imaging resulted in higher spatial resolution, which was advantageous when separating closely related anatomical structures (i.e. trabecular and compact bone, biomaterials). Fp-VCT facilitated imaging of alterations occurring in test specimens over time. fp-VCTs therefore displayed high volume coverage, dynamic imaging potential and superior performance when investigating superfine bone structures and bone remodelling of biomaterials. Thus, fp-VCTs may be a suitable instrument for intraoperative imaging and future in vivo tissue-engineering studies.

  5. Magnesium substitution in brushite cements for enhanced bone tissue regeneration.

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    Cabrejos-Azama, Jatsue; Alkhraisat, Mohammad Hamdan; Rueda, Carmen; Torres, Jesús; Blanco, Luis; López-Cabarcos, Enrique

    2014-10-01

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p<0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations.

  6. Magnesium substitution in brushite cements for enhanced bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Cabrejos-Azama, Jatsue, E-mail: jacaza@farm.ucm.es [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); Alkhraisat, Mohammad Hamdan; Rueda, Carmen [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Torres, Jesús [Facultad de Ciencias de la salud URJC, Alcorcón, Madrid (Spain); Blanco, Luis [Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); López-Cabarcos, Enrique [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain)

    2014-10-01

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p < 0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations. - Highlights: • The Mg-CPCs promote higher new bone formation than the CPC. • The incorporation of magnesium ions in CPC improves osteoblasts proliferation. • Mg-CPC is a bone substitute with controllable biodegradable properties. • We suggest that the use of Mg ions could improve the clinical efficiency of CPCs.

  7. Physicochemical Characteristics of Bone Substitutes Used in Oral Surgery in Comparison to Autogenous Bone

    Directory of Open Access Journals (Sweden)

    Antoine Berberi

    2014-01-01

    Full Text Available Bone substitutes used in oral surgery include allografts, xenografts, and synthetic materials that are frequently used to compensate bone loss or to reinforce repaired bone, but little is currently known about their physicochemical characteristics. The aim of this study was to evaluate a number of physical and chemical properties in a variety of granulated mineral-based biomaterials used in dentistry and to compare them with those of autogenous bone. Autogenous bone and eight commercial biomaterials of human, bovine, and synthetic origins were studied by high-resolution X-ray diffraction, atomic absorption spectrometry, and laser diffraction to determine their chemical composition, calcium release concentration, crystallinity, and granulation size. The highest calcium release concentration was 24. 94 mg/g for Puros and the lowest one was 2.83 mg/g for Ingenios β-TCP compared to 20.15 mg/g for natural bone. The range of particles sizes, in terms of median size D50, varied between 1.32 μm for BioOss and 902.41 μm for OsteoSponge, compared to 282.1 μm for natural bone. All samples displayed a similar hexagonal shape as bone, except Ingenios β-TCP, Macrobone, and OsteoSponge, which showed rhomboid and triclinic shapes, respectively. Commercial bone substitutes significantly differ in terms of calcium concentration, particle size, and crystallinity, which may affect their in vivo performance.

  8. Rapid prototyped porous nickel-titanium scaffolds as bone substitutes.

    Science.gov (United States)

    Hoffmann, Waldemar; Bormann, Therese; Rossi, Antonella; Müller, Bert; Schumacher, Ralf; Martin, Ivan; de Wild, Michael; Wendt, David

    2014-01-01

    While calcium phosphate-based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel-titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel-titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel-titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel-titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel-titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel-titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold's pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel-titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used titanium.

  9. Rapid prototyped porous nickel–titanium scaffolds as bone substitutes

    Directory of Open Access Journals (Sweden)

    Waldemar Hoffmann

    2014-06-01

    Full Text Available While calcium phosphate–based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel–titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel–titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel–titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel–titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel–titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel–titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold’s pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel–titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used

  10. Bioactive behavior of silicon substituted calcium phosphate based bioceramics for bone regeneration.

    Science.gov (United States)

    Khan, Ather Farooq; Saleem, Muhammad; Afzal, Adeel; Ali, Asghar; Khan, Afsar; Khan, Abdur Rahman

    2014-02-01

    Bone graft substitutes are widely used for bone regeneration and repair in defect sites resulting from aging, disease, trauma, or accident. With invariably increasing clinical demands, there is an urgent need to produce artificial materials, which are readily available and are capable of fast and guided skeletal repair. Calcium phosphate based bioactive ceramics are extensively utilized in bone regeneration and repair applications. Silicon is often utilized as a substituent or a dopant in these bioceramics, since it significantly enhances the ultimate properties of conventional biomaterials such as surface chemical structure, mechanical strength, bioactivity, biocompatibility, etc. This article presents an overview of the silicon substituted bioceramics, which have emerged as efficient bone replacement and bone regeneration materials. Thus, the role of silicon in enhancing the biological performance and bone forming capabilities of conventional calcium phosphate based bioceramics is identified and reviewed.

  11. Synthetic bone substitute engineered with amniotic epithelial cells enhances bone regeneration after maxillary sinus augmentation.

    Directory of Open Access Journals (Sweden)

    Barbara Barboni

    Full Text Available BACKGROUND: Evidence has been provided that a cell-based therapy combined with the use of bioactive materials may significantly improve bone regeneration prior to dental implant, although the identification of an ideal source of progenitor/stem cells remains to be determined. AIM: In the present research, the bone regenerative property of an emerging source of progenitor cells, the amniotic epithelial cells (AEC, loaded on a calcium-phosphate synthetic bone substitute, made by direct rapid prototyping (rPT technique, was evaluated in an animal study. MATERIAL AND METHODS: Two blocks of synthetic bone substitute (∼0.14 cm(3, alone or engineered with 1×10(6 ovine AEC (oAEC, were grafted bilaterally into maxillary sinuses of six adult sheep, an animal model chosen for its high translational value in dentistry. The sheep were then randomly divided into two groups and sacrificed at 45 and 90 days post implantation (p.i.. Tissue regeneration was evaluated in the sinus explants by micro-computer tomography (micro-CT, morphological, morphometric and biochemical analyses. RESULTS AND CONCLUSIONS: The obtained data suggest that scaffold integration and bone deposition are positively influenced by allotransplantated oAEC. Sinus explants derived from sheep grafted with oAEC engineered scaffolds displayed a reduced fibrotic reaction, a limited inflammatory response and an accelerated process of angiogenesis. In addition, the presence of oAEC significantly stimulated osteogenesis either by enhancing bone deposition or making more extent the foci of bone nucleation. Besides the modulatory role played by oAEC in the crucial events successfully guiding tissue regeneration (angiogenesis, vascular endothelial growth factor expression and inflammation, data provided herein show that oAEC were also able to directly participate in the process of bone deposition, as suggested by the presence of oAEC entrapped within the newly deposited osteoid matrix and by their

  12. Bone defect animal models for testing efficacy of bone substitute biomaterials

    Directory of Open Access Journals (Sweden)

    Ye Li

    2015-07-01

    Full Text Available Large bone defects are serious complications that are most commonly caused by extensive trauma, tumour, infection, or congenital musculoskeletal disorders. If nonunion occurs, implantation for repairing bone defects with biomaterials developed as a defect filler, which can promote bone regeneration, is essential. In order to evaluate biomaterials to be developed as bone substitutes for bone defect repair, it is essential to establish clinically relevant in vitro and in vivo testing models for investigating their biocompatibility, mechanical properties, degradation, and interactional with culture medium or host tissues. The results of the in vitro experiment contribute significantly to the evaluation of direct cell response to the substitute biomaterial, and the in vivo tests constitute a step midway between in vitro tests and human clinical trials. Therefore, it is essential to develop or adopt a suitable in vivo bone defect animal model for testing bone substitutes for defect repair. This review aimed at introducing and discussing the most available and commonly used bone defect animal models for testing specific substitute biomaterials. Additionally, we reviewed surgical protocols for establishing relevant preclinical bone defect models with various animal species and the evaluation methodologies of the bone regeneration process after the implantation of bone substitute biomaterials. This review provides an important reference for preclinical studies in translational orthopaedics.

  13. Supercritical carbon dioxide-processed resorbable polymer nanocomposites for bone graft substitute applications

    Science.gov (United States)

    Baker, Kevin C.

    Numerous clinical situations necessitate the use of bone graft materials to enhance bone formation. While autologous and allogenic materials are considered the gold standards in the setting of fracture healing and spine fusion, their disadvantages, which include donor site morbidity and finite supply have stimulated research and development of novel bone graft substitute materials. Among the most promising candidate materials are resorbable polymers, composed of lactic and/or glycolic acid. While the characteristics of these materials, such as predictable degradation kinetics and biocompatibility, make them an excellent choice for bone graft substitute applications, they lack mechanical strength when synthesized with the requisite porous morphology. As such, porous resorbable polymers are often reinforced with filler materials. In the presented work, we describe the use of supercritical carbon dioxide (scCO2) processing to create porous resorbable polymeric constructs reinforced by nanostructured, organically modified Montmorillonite clay (nanoclay). scCO2 processing simultaneously disperses the nanoclay throughout the polymeric matrix, while imparting a porous morphology to the construct conducive to facilitating cellular infiltration and neoangiogenesis, which are necessary components of bone growth. With the addition of as little as 2.5wt% of nanoclay, the compressive strength of the constructs nearly doubles putting them on par with human cortico-cancellous bone. Rheological measurements indicate that the dominant mode of reinforcement of the nanocomposite constructs is the restriction of polymer chain mobility. This restriction is a function of the positive interaction between polymer chains and the nanoclay. In vivo inflammation studies indicate biocompatibility of the constructs. Ectopic osteogenesis assays have determined that the scCO2-processed nanocomposites are capable of supporting growth-factor induced bone formation. scCO 2-processed resorbable

  14. Characterization of the inflammatory response to four commercial bone graft substitutes using a murine biocompatibility model

    Directory of Open Access Journals (Sweden)

    Markel DC

    2012-01-01

    Full Text Available David C Markel1, S Trent Guthrie2, Bin Wu3, Zheng Song4, Paul H Wooley41Department of Orthopaedics, Providence Hospital and Medical Centers, Southfield, MI, 2Henry Ford Hospital, Detroit, MI, 3Department of Biomedical Engineering, Wayne State University, Detroit, MI, 4Orthopaedic Research Institute, Wichita, KS, USAAbstract: Bone grafting is utilized in nearly all orthopedic subspecialties and in most anatomic regions. Bone graft substitutes have the potential to offer similar efficacy as autogenous grafts without the morbidity of harvest. Several studies have noted the efficacy of new-generation bone substitute products, but few studies have evaluated their safety. This study characterizes and quantifies the inflammatory reaction to four different commercially available bone graft substitutes, which were examined using the in vivo murine air pouch biocompatibility model. One coralline hydroxyapatite product was chosen as an example of a purely osteoconductive material. Three demineralized bone matrix products were chosen to represent products that are both osteoconductive and osteoinductive. Samples were implanted in a murine air pouch and harvested after 14 days in situ. Pouch fluid was extracted, mRNA isolated, and reverse transcription polymerase chain reactions carried out to detect interleukin-1 gene expression as a marker for inflammation. In addition, multiple histological characteristics were examined to quantify cellular responses to the implanted materials. All bone graft substitutes induced a significant inflammatory response compared with negative controls. Histology and polymerase chain reaction data indicated that the level of inflammatory reaction was elevated in materials with a higher demineralized bone matrix to carrier proportion. The hydroxyapatite product generated a low inflammatory reaction. In conclusion, this study used an in vivo model of biocompatibility to demonstrate that a significant inflammatory reaction occurs

  15. Controlling Bone Graft Substitute Microstructure to Improve Bone Augmentation.

    Science.gov (United States)

    Sheikh, Zeeshan; Drager, Justin; Zhang, Yu Ling; Abdallah, Mohamed-Nur; Tamimi, Faleh; Barralet, Jake

    2016-07-01

    Vertical bone augmentation procedures are frequently carried out to allow successful placement of dental implants in otherwise atrophic ridges and represent one of the most common bone grafting procedures currently performed. Onlay autografting is one of the most prevalent and predictable techniques to achieve this; however, there are several well documented complications and drawbacks associated with it and synthetic alternatives are being sought. Monetite is a bioresorbable dicalcium phosphate with osteoconductive and osteoinductive potential that has been previously investigated for onlay bone grafting and it is routinely made by autoclaving brushite to simultaneously sterilize and phase convert. In this study, monetite disc-shaped grafts are produced by both wet and dry heating methods which alter their physical properties such as porosity, surface area, and mechanical strength. Histological observations after 12 weeks of onlay grafting on rabbit calvaria reveal higher bone volume (38%) in autoclaved monetite grafts in comparison with the dry heated monetite grafts (26%). The vertical bone height gained is similar for both the types of monetite grafts (up to 3.2 mm). However, it is observed that the augmented bone height is greater in the lateral than the medial areas of both types of monetite grafts. It is also noted that the higher porosity of autoclaved monetite grafts increases the bioresorbability, whereas the dry heated monetite grafts having lower porosity but higher surface area resorb to a significantly lesser extent. This study provides information regarding two types of monetite onlay grafts prepared with different physical properties that can be further investigated for clinical vertical bone augmentation applications.

  16. Microtomographic and morphometric characterization of a bioceramic bone substitute in dental implantology

    Directory of Open Access Journals (Sweden)

    Deborah Meleo

    2012-01-01

    Full Text Available In recent years, bone tissue regeneration studies have led to a deeper knowledge of chemical and structural features of the best biomaterials to be used as replacements for lost bone structures, with the autologus bone still today the only graft material able to ostegenerate, osteinduct and/or osteoconduct. The difficulties of the small available amount of autologus bone, together with morbidity of a second surgical operation on the same patient, have been overcome using both synthetic and biologic substitute bones. The possibility of investigating morphometric characteristics of substitute bones makes it possible to evaluate the predictability of regenerative processes and, so far, a range of different methods have been used for the purpose. X-ray microtomography (micro-CT is a miniaturized form of conventional tomography, able to analyze the internal structure of small objects, performing three-dimensional images with high spatial resolution (<10 micron pixel size. For a correct analysis, samples need not be altered or treated in any way, as micro-CT is a non-invasive and non-destructive technique. It shows promising results in biomaterial studies and tissue engineering. This work shows the potential applications of this microtomographic technique by means of an in vitro analysis system, in characterizing morphometric features of human bone tissue, and contributes to the use of this technique in studies concerning biomaterials and bioscaffolds inserted in bone tissue.

  17. Characterization of silane coated hollow sphere alumina-reinforced ultra high molecular weight polyethylene composite as a possible bone substitute material

    Indian Academy of Sciences (India)

    S Roy; S Pal

    2002-12-01

    Silane coated hollow sphere alumina ceramic particles were moulded with ultra high molecular weight polyethylene (UHMWPE) to form a series of composites with alumina weight percent in the range from 15 to 50. The composites were prepared in a cylindrical mould using powder-processing technique. The composites were characterized for mechanical properties using destructive and non-destructive ultrasonic testing methods. The physical properties of the composite were determined and compared with those of cortical bone.

  18. The study of bone repair effect of recombinant human bone morphogenetic protein-2 combined with artificial bone substitute materials in alveolar defect around the dental implant%骨形态发生蛋白2复合人工骨替代材料修复犬种植体周骨缺损的研究

    Institute of Scientific and Technical Information of China (English)

    张敬阳; 黄翠

    2014-01-01

    Objective To evaluate the bone repair capacity of β-tricalciumphosphate (β-TCP) or Bio-Oss combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in Beagle dogs.Methods Ten healthy adult Beagle dogs were used in this study.The mandibular premolars of the dogs were extracted firstly.Three months later,dental implants were placed in the mandibular,and a 5 mm× 4 mm× 3 mm bone defect area was prepared on the buccal side of each implant.The bone defect areas were filled with β-TCP,rhBMP-2/β-TCP compound,Bio-Oss or rhBMP-2/Bio-Oss compound respectively.The bone defect areas were filled nothing as the blank.The dogs were sacrificed after 4 or 12 weeks.Samples were prepared for the gross observation,X-ray analysis and histomorphology analysis.Results The new bone formation was observed in all experiment groups.After 4 weeks,the bone density of materials combined with rhBMP-2 groups [(36.70 ± 1.73) % and (38.50 ± 1.83) %] were higher than the raw materials groups [(30.50 ± 1.81)% and (31.48 ± 1.86)%].After 12 weeks,the bone density of materials combined with rhBMP-2 groups [(52.84 ± 1.85) % and (54.85 ± 1.87) %] were also higher than the raw materials groups [(43.65 ± 1.81) % and (44.94 ± 1.88) %].And new bone formation rate of the materials combined with rhBMP-2 groups were higher than the raw materials groups at each evaluation time.Conclusion rhBMP-2 can promote the bone regeneration activity of the artificial bone substitute materials effectively.%目的 观察重组人骨形态发生蛋白-2(rhBMP-2)复合β-磷酸三钙(β-TCP)及无机牛骨(Bio-Oss)对骨缺损修复能力的影响.方法 拔除10条Beagle犬下颌前磨牙,3个月骨质愈合后预备种植窝并制备5 mm×4 mm×3 mm骨缺损区,植入种植体,并分别在骨缺损区填入β-TCP、rhBMP-2/β-TCP复合物、Bio-Oss或rhBMP-2/Bio-Oss复合物;空白对照组不充填.术后4、12周处死犬,行大体观察、X线观察和组织形态

  19. Hydroxyapatite-calcium sulfate-hyaluronic acid composite encapsulated with collagenase as bone substitute for alveolar bone regeneration.

    Science.gov (United States)

    Subramaniam, Sadhasivam; Fang, Yen-Hsin; Sivasubramanian, Savitha; Lin, Feng-Huei; Lin, Chun-pin

    2016-01-01

    Periodontitis is a very severe inflammatory condition of the periodontium that progressively damages the soft tissue and destroys the alveolar bone that supports the teeth. The bone loss is naturally irreversible because of limited reparability of the teeth. Advancement in tissue engineering provides an effective regeneration of osseous defects with suitable dental implants or tissue-engineered constructs. This study reports a hydroxyapatite, calcium sulfate hemihydrate and hyaluronic acid laden collagenase (HAP/CS/HA-Col) as a bone substitute for the alveolar bone regeneration. The composite material was mechanically tested and the biocompatibility was evaluated by WST-1 assay. The in vivo bone formation was assessed in rat with alveolar bone defects and the bone augmentation by the HAP/CS/HA-Col composite was confirmed by micro-CT images and histological examination. The mechanical strength of 6.69 MPa with excellent biocompatibility was obtained for the HAP/CS/HA-Col composite. The collagenase release profile had facilitated the acceleration of bone remodeling process and it was confirmed by the findings of micro-CT and H&E staining. The bone defects implanted with HAP/CS/HA composite containing 2 mg/mL type I collagenase have shown improved new bone formation with matured bone morphology in comparison with the HAP/CS/HA composite that lacks the collagenase and the porous hydroxyapatite (p-HAP) granules. The said findings demonstrated that the collagenase inclusion in HAP/CS/HA composite is a feasible approach for the alveolar bone regeneration and the same design can also be applied to other defective tissues.

  20. Journey of bone graft materials in periodontal therapy: A chronological review

    Directory of Open Access Journals (Sweden)

    Jitendra Kumar

    2016-01-01

    Full Text Available Bone, the basic building block of the healthy periodontium, is affected in most of the periodontal diseases and can be managed either by mechanically recontouring it or by grafting techniques, which encourages regeneration where it has been lost. Bone replacement grafts are widely used to promote bone formation and periodontal regeneration. Bone grafting, placing bone or bone substitutes into defects created by the disease process, acts like a scaffold upon which the body generates its own, new bone. A wide range of bone grafting materials, including bone grafts and bone graft substitutes, have been applied and evaluated clinically, including autografts, allografts, xenografts, and alloplasts. This review provides an overview of the clinical application, biologic function, and advantages and disadvantages of various types of bone graft materials used in periodontal therapy till date with emphasis on recent advances in this field.

  1. No effect of Osteoset, a bone graft substitute, on bone healing in humans: a prospective randomized double-blind study

    DEFF Research Database (Denmark)

    Petruskevicius, Juozas; Nielsen, Mette Strange; Kaalund, Søren;

    2002-01-01

    We studied the effects of a newly marketed bone substitute, Osteoset, on bone healing in a tibial defect in humans. 20 patients undergoing an ACL (anterior cruciate ligament) reconstruction with bone-patella tendon-bone graft were block-randomized into 2 groups of 10 each. In the treatment group...

  2. Tusk or Bone? An Example of Ivory Substitute in the Wildlife Trade

    Directory of Open Access Journals (Sweden)

    Margaret E. Sims

    2011-08-01

    Full Text Available Bone carvings (and other ivory substitutes are common in the modern-day lucrative international ivory trade.  Souvenirs for unknowing travelers and market shoppers can be made of non-biological material (plastic "ivory" beads or skillfully crafted natural objects made to resemble something other than their true origin.  Many of these items are received at the U. S. National Fish and Wildlife Forensics Laboratory (NFWFL for species identification as part of law enforcement investigations.  Morphologists at the Lab often receive uniquely carved ivory items that have been imported with little or no documentation.  In recent years, analysts examined several purported ivory tusks suspected to be walrus, a protected marine mammal.  After examination, the Lab determined their origin as carved leg bones of cattle using principles and methods of zooarchaeology and ancient DNA analysis.  The naturally long and straight ungulate metapodials had been cut, carved, filled, stained, and polished to closely resemble unmodified ivory tusks.  Morphological species identification of these bones proved to be a challenge since diagnostic characters of the bones had been altered and country of origin was unknown. Genetic analysis showed that the bones originated from cattle.  While bone is commonly used as a substitute for ivory, this style of artifact was not previously documented in the wildlife trade prior to our analysis.  Archaeological ethnobiologists commonly encounter bone tools and other forms of material culture from prehistoric and historic contexts; in this case bone tools come from a modern context, thus the application of methods common in zooarchaeology are situated in wildlife forensics.  In addition, results reported here pertain to cross-cultural ivory trade and conservation science.

  3. Dual mode antibacterial activity of ion substituted calcium phosphate nanocarriers for bone infections

    Directory of Open Access Journals (Sweden)

    Sampath Kumar eT.S.

    2015-05-01

    Full Text Available Nanotechnology has tremendous potential for the management of infectious diseases caused by multi-drug resistant (MDR bacteria, through the development of newer antibacterial materials and efficient modes of antibiotic delivery. Calcium phosphate (CaP bioceramics are commonly used as bone substitutes due to their similarity to bone mineral and are widely researched upon for the treatment of bone infections associated with bone loss. CaPs can be used as local antibiotic delivery agents for bone infections and can be substituted with antibacterial ions in their crystal structure to have a wide spectrum, sustained antibacterial activity even against drug resistant bacteria. In the present work, a dual mode antibiotic delivery system with antibacterial ion substituted calcium deficient hydroxyapatite (CDHA nanoparticles has been developed. Antibacterial ions such as zinc, silver and strontium have been incorporated into CDHA at concentrations of 6 at. %, 0.25-0.75 at. % and 2.5-7.5 at. % respectively. The samples were found to be phase pure, acicular nanoparticles of length 40-50 nm and width 5-6 nm approximately. The loading and release profile of doxycycline, a commonly used antibiotic, was studied from the nanocarriers. The drug release was studied for five days and the release profile was influenced by the ion concentrations. The release of antibacterial ions was studied over a period of 21 days. The ion substituted CDHA samples were tested for antibacterial efficacy on S.aureus and E.coli by MIC/MBC studies and time-kill assay. AgCDHA and ZnCDHA showed high antibacterial activity against both bacteria while SrCDHA was weakly active against S.aureus. Present study shows that the antibiotic release can provide the initial high antibacterial activity and the sustained ion release can provide a long-term antibacterial activity. Such dual mode antibiotic and antibacterial ion release offers an efficient and potent way to treat an incumbent drug

  4. Biologic and clinical aspects of integration of different bone substitutes in oral surgery: a literature review.

    Science.gov (United States)

    Zizzari, Vincenzo Luca; Zara, Susi; Tetè, Giulia; Vinci, Raffaele; Gherlone, Enrico; Cataldi, Amelia

    2016-10-01

    Many bone substitutes have been proposed for bone regeneration, and researchers have focused on the interactions occurring between grafts and host tissue, as the biologic response of host tissue is related to the origin of the biomaterial. Bone substitutes used in oral and maxillofacial surgery could be categorized according to their biologic origin and source as autologous bone graft when obtained from the same individual receiving the graft; homologous bone graft, or allograft, when harvested from an individual other than the one receiving the graft; animal-derived heterologous bone graft, or xenograft, when derived from a species other than human; and alloplastic graft, made of bone substitute of synthetic origin. The aim of this review is to describe the most commonly used bone substitutes, according to their origin, and to focus on the biologic events that ultimately lead to the integration of a biomaterial with the host tissue.

  5. A Simulation Study of Solving Material Substitution Problem

    Directory of Open Access Journals (Sweden)

    Yu-Hsin Lin

    2013-01-01

    Full Text Available The material substitution problem is a critical decision issue in the assembly industry. In practice, this problem is usually solved with managers’ experiences. However, the management objectives of material substitution are various and sometimes there are conflicts between different departments. Therefore, it needs a comprehensive analysis to assess the effectiveness of adopting substitution material under different management objectives. This research uses simulation model to analyze the effectiveness of material substitution policy which includes external substitution, internal substitution and general use of material. Full factorial experimental design was applied to find the performance of proposed material substitution policy, and order quantity, purchase lead-time, due-date variance, order arrival interval, and delay cost were chosen as independent variables. The average flow time, order delay time, order fulfillment rate, and system cost were chosen as dependent variables. Experimental results showed that material substitution policies are significant on all dependent variables. Especially the external substitution policy performed better than the others in the observed four performance indices. Through external substitution policy can improve order fulfillment rate and reduce average flow time. That is, applying external substitution policy can make a great improvement in customer satisfaction which is the most impact factor in satisfying customers under the mass customization environment.

  6. Development and mechanical characterization of porous titanium bone substitutes.

    Science.gov (United States)

    Barbas, A; Bonnet, A-S; Lipinski, P; Pesci, R; Dubois, G

    2012-05-01

    Commercially Pure Porous Titanium (CPPTi) can be used for surgical implants to avoid the stress shielding effect due to the mismatch between the mechanical properties of titanium and bone. Most researchers in this area deal with randomly distributed pores or simple architectures in titanium alloys. The control of porosity, pore size and distribution is necessary to obtain implants with mechanical properties close to those of bone and to ensure their osseointegration. The aim of the present work was therefore to develop and characterize such a specific porous structure. First of all, the properties of titanium made by Selective Laser Melting (SLM) were characterized through experimental testing on bulk specimens. An elementary pattern of the porous structure was then designed to mimic the orthotropic properties of the human bone following several mechanical and geometrical criteria. Finite Element Analysis (FEA) was used to optimize the pattern. A porosity of 53% and pore sizes in the range of 860 to 1500 μm were finally adopted. Tensile tests on porous samples were then carried out to validate the properties obtained numerically and identify the failure modes of the samples. Finally, FE elastoplastic analyses were performed on the porous samples in order to propose a failure criterion for the design of porous substitutes.

  7. Evaluation of injectable silica-embedded nanohydroxyapatite bone substitute in a rat tibia defect model

    Directory of Open Access Journals (Sweden)

    Xu W

    2011-08-01

    Full Text Available Weiguo Xu1, Cornelia Ganz2, Ulf Weber2, Martin Adam2, Gerd Holzhüter2, Daniel Wolter3, Bernhard Frerich3, Brigitte Vollmar1, Thomas Gerber21Institute for Experimental Surgery, 2Institute of Physics, 3Department of Oral, Maxillofacial and Plastic Surgery, University of Rostock, Rostock, GermanyAbstract: In clinical practice, vertebral compression fractures occur after trauma and osteoporosis. Kyphoplasty is a minimally invasive procedure using bone filler material for the treatment of such fractures. A full synthetic injectable bone substitute (SIBS was manufactured by means of spray drying. The aim of this study was to characterize the SIBS and to analyze the remodelling process during degradation of the biomaterial and new bone formation after implantation. SIBS is an aqueous suspension of donut-like microparticles. These microparticles consist of nanocrystallites of synthetic hydroxyapatite embedded in amorphous silica gel. After implantation of SIBS in a proximal tibial diaphyseal defect in 52 rats, grafts were harvested for subsequent analysis on different days. Newly formed bone originating from endosteum was observed on day 6. Hematomas in the medullary space and cortical wounds disappeared on day 12. The wound region was completely replaced by a composite of newly formed cancellous bone, extracellular matrix, and SIBS. At day 63 the cortical defect was fully healed by bone, while newly formed bone in the medullary space almost disappeared and was replaced with bone marrow. In conclusion, SIBS demonstrated a unique structure with osteoinductive and bioresorbable properties, which induced fast bone regeneration. Therefore, a clinical application of SIBS for kyphoplasty is promising.Keywords: bone remodelling, electron microscopy, histomorphometry, nanotechnology, tissue engineering

  8. Brushite-Forming Mg-, Zn- and Sr-Substituted Bone Cements for Clinical Applications

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    José M.F. Ferreira

    2010-01-01

    Full Text Available Calcium phosphate cements have been in clinical use for the last 10 years. Their most salient features include good biocompatibility, excellent bioactivity, self-setting characteristics, low setting temperature, adequate stiffness, and easy shaping to accomodate any complicated geometry. They are commonly used in filling bone defects and trauma surgeries as mouldable paste-like bone substitute materials. Substitution of trace elements, such as Mg, Sr and Zn ions, into the structure of calcium phosphates is the subject of widespread investigation nowadays, because of their impending role in the biological process. Subtle differences in composition and structure of these materials may have a profound effect on their in vivo behaviour. Therefore, the main goal of this paper is to provide a simple, but comprehensive overview of the present achievements relating to brushite-forming cements doped with Mg, Zn and Sr, and to identify new developments and trends. In particular, the influence of ionic substitution on the chemical, physical and biological properties of these materials is discussed.

  9. Morphological and mechanical characterization of chitosan-calcium phosphate composites for potential application as bone-graft substitutes

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    Guilherme Maia Mulder van de Graaf

    Full Text Available Introduction: Bone diseases, aging and traumas can cause bone loss and lead to bone defects. Treatment of bone defects is challenging, requiring chirurgical procedures. Bone grafts are widely used for bone replacement, but they are limited and expensive. Due to bone graft limitations, natural, semi-synthetic, synthetic and composite materials have been studied as potential bone-graft substitutes. Desirable characteristics of bone-graft substitutes are high osteoinductive and angiogenic potentials, biological safety, biodegradability, bone-like mechanical properties, and reasonable cost. Herein, we prepared and characterized potential bone-graft substitutes composed of calcium phosphate (CP - a component of natural bone, and chitosan (CS - a biocompatible biopolymer. Methods CP-CS composites were synthetized, molded, dried and characterized. The effect of drying temperatures (38 and 60 °C on the morphology, porosity and chemical composition of the composites was evaluated. As well, the effects of drying temperature and period of drying (3, 24, 48 and 72 hours on the mechanical properties - compressive strength, modulus of elasticity and relative deformation-of the demolded samples were investigated. Results Scanning electron microscopy and gas adsorption-desorption analyses of the CS-CP composites showed interconnected pores, indicating that the drying temperature played an important role on pores size and distribution. In addition, drying temperature have altered the color (brownish at 60 °C due to Maillard reaction and the chemical composition of the samples, confirmed by FTIR. Conclusion Particularly, prolonged period of drying have improved mechanical properties of the CS-CP composites dried at 38 °C, which can be designed according to the mechanical needs of the replaceable bone.

  10. A novel calcium phosphate ceramic-magnetic nanoparticle composite as a potential bone substitute.

    Science.gov (United States)

    Wu, Yao; Jiang, Wen; Wen, Xiantao; He, Bin; Zeng, Xiaobo; Wang, Gang; Gu, Zhongwei

    2010-02-01

    A magnetic field has been applied to accelerate bone healing for a long time. In this study, in order to combine the bone repair capability of calcium phosphate (CaP) ceramics with the magnetic field, a novel CaP ceramic-magnetic nanoparticle (CaP-MNP) composite was fabricated through integrating the superparamagnetic nanoparticles into the CaP ceramics. Two kinds of CaP ceramics were chosen: hydroxyapatite (HA) and HA/tricalcium phosphate (65/35, HT). The samples were cultured with Ros17/2.8 and MG63 cells respectively in vitro to evaluate the cell proliferation and differentiation via MTT and alkaline phosphatase activity tests. In order to find the influence of the magnetic materials on the expression of the bone morphological protein (BMP), the samples composited with BMP-2 were implanted subcutaneously in the fasciae of rat back muscles for 30 days. Compared with ordinary CaP ceramics, the results indicated that the CaP-MNP composite had good biocompatibility and was able to promote cell proliferation and differentiation significantly. The in vivo test showed that the expression of BMP-2 would be accelerated by HT composited with MNPs, and new bone-like tissue formation could be observed. Accordingly, it might be expected that this CaP-MNP composite could become a potential bone substitute or bone tissue engineering scaffold.

  11. Effects of a perfusion bioreactor activated novel bone substitute in spine fusion in sheep

    DEFF Research Database (Denmark)

    Sørensen, Jesper Roed; Koroma, Kariatta Ester; Ding, Ming;

    2012-01-01

    To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model.......To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model....

  12. Bioactive glass incorporation in calcium phosphate cement-based injectable bone substitute for improved in vitro biocompatibility and in vivo bone regeneration.

    Science.gov (United States)

    Sadiasa, Alexander; Sarkar, Swapan Kumar; Franco, Rose Ann; Min, Young Ki; Lee, Byong Taek

    2014-01-01

    In this work, we fabricated injectable bone substitutes modified with the addition of bioactive glass powders synthesized via ultrasonic energy-assisted hydrothermal method to the calcium phosphate-based bone cement to improve its biocompatibility. The injectable bone substitutes was initially composed of a powder component (tetracalcium phosphate, dicalcium phosphate dihydrate and calcium sulfate dehydrate) and a liquid component (citric acid, chitosan and hydroxyl-propyl-methyl-cellulose) upon which various concentrations of bioactive glass were added: 0%, 10%, 20% and 30%. Setting time and compressive strength of the injectable bone substitutes were evaluated and observed to improve with the increase of bioactive glass content. Surface morphologies were observed via scanning electron microscope before and after submersion of the samples to simulated body fluid and increase in apatite formation was detected using x-ray diffraction machine. In vitro biocompatibility of the injectable bone substitutes was observed to improve with the addition of bioactive glass as the proliferation/adhesion behavior of cells on the material increased. Human gene markers were successfully expressed using real time-polymerase chain reaction and the samples were found to promote cell viability and be more biocompatible as the concentration of bioactive glass increases. In vivo biocompatibility of the samples containing 0% and 30% bioactive glass were evaluated using Micro-CT and histological staining after 3 months of implantation in male rabbits' femurs. No inflammatory reaction was observed and significant bone formation was promoted by the addition of bioactive glass to the injectable bone substitute system.

  13. Minimally Invasive Alveolar Ridge Preservation Utilizing an In Situ Hardening β-Tricalcium Phosphate Bone Substitute: A Multicenter Case Series

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    Minas D. Leventis

    2016-01-01

    Full Text Available Ridge preservation measures, which include the filling of extraction sockets with bone substitutes, have been shown to reduce ridge resorption, while methods that do not require primary soft tissue closure minimize patient morbidity and decrease surgical time and cost. In a case series of 10 patients requiring single extraction, in situ hardening beta-tricalcium phosphate (β-TCP granules coated with poly(lactic-co-glycolic acid (PLGA were utilized as a grafting material that does not necessitate primary wound closure. After 4 months, clinical observations revealed excellent soft tissue healing without loss of attached gingiva in all cases. At reentry for implant placement, bone core biopsies were obtained and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological and histomorphometrical analysis revealed pronounced bone regeneration (24.4 ± 7.9% new bone in parallel to the resorption of the grafting material (12.9 ± 7.7% graft material while high levels of primary implant stability were recorded. Within the limits of this case series, the results suggest that β-TCP coated with polylactide can support new bone formation at postextraction sockets, while the properties of the material improve the handling and produce a stable and porous bone substitute scaffold in situ, facilitating the application of noninvasive surgical techniques.

  14. Minimally Invasive Alveolar Ridge Preservation Utilizing an In Situ Hardening β-Tricalcium Phosphate Bone Substitute: A Multicenter Case Series

    Science.gov (United States)

    Leventis, Minas D.; Fairbairn, Peter; Kakar, Ashish; Leventis, Angelos D.; Margaritis, Vasileios; Lückerath, Walter; Horowitz, Robert A.; Rao, Bappanadu H.; Lindner, Annette; Nagursky, Heiner

    2016-01-01

    Ridge preservation measures, which include the filling of extraction sockets with bone substitutes, have been shown to reduce ridge resorption, while methods that do not require primary soft tissue closure minimize patient morbidity and decrease surgical time and cost. In a case series of 10 patients requiring single extraction, in situ hardening beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic acid) (PLGA) were utilized as a grafting material that does not necessitate primary wound closure. After 4 months, clinical observations revealed excellent soft tissue healing without loss of attached gingiva in all cases. At reentry for implant placement, bone core biopsies were obtained and primary implant stability was measured by final seating torque and resonance frequency analysis. Histological and histomorphometrical analysis revealed pronounced bone regeneration (24.4 ± 7.9% new bone) in parallel to the resorption of the grafting material (12.9 ± 7.7% graft material) while high levels of primary implant stability were recorded. Within the limits of this case series, the results suggest that β-TCP coated with polylactide can support new bone formation at postextraction sockets, while the properties of the material improve the handling and produce a stable and porous bone substitute scaffold in situ, facilitating the application of noninvasive surgical techniques. PMID:27190516

  15. The efficacy of poly-d,l-lactic acid- and hyaluronic acid-coated bone substitutes on implant fixation in sheep

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    Christina M. Andreasen

    2017-01-01

    Conclusion: This study demonstrates that HA/βTCP granules coated with PDLLA and HyA have similar bone ingrowth and implant fixation as those with allograft, and with mechanical properties resembling those of allograft in advance, they may be considered as alternative substitute materials for bone formation in sheep.

  16. Bone Regeneration Using a Mixture of Silicon-Substituted Coral HA and β-TCP in a Rat Calvarial Bone Defect Model

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    Jiyeon Roh

    2016-02-01

    Full Text Available The demand of bone graft materials has been increasing. Among various origins of bone graft materials, natural coral composed of up to 99% calcium carbonate was chosen and converted into hydroxyapatite (HA; silicon was then substituted into the HA. Then, the Si-HA was mixed with β-tricalcium phosphate (TCP in the ratios 100:0 (S100T0, 70:30 (S70T30, 60:40 (S60T40, and 50:50 (S50T50. The materials were implanted for four and eight weeks in a rat calvarial bone defect model (8 mm. The MBCPTM (HA:β-TCP = 60:40, Biomatalante, Vigneux de Bretagne, France was used as a control. After euthanasia, the bone tissue was analyzed by making histological slides. From the results, S60T40 showed the fastest bone regeneration in four weeks (p < 0.05. In addition, S60T40, S50T50, and MBCPTM showed significant new bone formation in eight weeks (p < 0.05. In conclusion, Si-HA/TCP showed potential as a bone graft material.

  17. Calcite as a bone substitute. Comparison with hydroxyapatite and tricalcium phosphate with regard to the osteoblastic activity

    Energy Technology Data Exchange (ETDEWEB)

    Monchau, F., E-mail: Francine.monchau@univ-artois.fr [Laboratoire Genie Civil et geo-Environnement (EA 4515, Universite Lille Nord de France), Equipe Biomateriaux Artois (Universite d' Artois), IUT/GMP, 1230, rue de l' Universite, BP 819, 62408 Bethune cedex (France); Hivart, Ph.; Genestie, B. [Laboratoire Genie Civil et geo-Environnement (EA 4515, Universite Lille Nord de France), Equipe Biomateriaux Artois (Universite d' Artois), IUT/GMP, 1230, rue de l' Universite, BP 819, 62408 Bethune cedex (France); Chai, F. [Laboratoire Medicaments et Biomateriaux a Liberation Controlee (INSERM U 1008, Universite Lille Nord de France), Groupe de Recherche sur les Biomateriaux (Universite Lille-2), Faculte de Medecine, 1, place de Verdun, 59045 Lille cedex (France); and others

    2013-01-01

    Close to the bone mineral phase, the calcic bioceramics, such as hydroxyapatite (HA) and {beta}-tricalcium phosphate ({beta}-TCP), are commonly used as substitutes or filling materials in bone surgery. Besides, calcium carbonate (CaCO{sub 3}) is also used for their excellent biocompatibility and bioactivity. However, the problem with the animal-origin aragonite demands the new technique to synthesize pure calcite capable of forming 3D bone implant. This study aims to manufacture and evaluate a highly-pure synthetic crystalline calcite with good cytocompatibility regarding to the osteoblasts, comparing to that of HA and {beta}-TCP. After the manufacture of macroporous bioceramic scaffolds with the identical internal architecture, their cytocompatibility is studied through MC3T3-E1 osteoblasts with the tests of cell viability, proliferation, vitality, etc. The results confirmed that the studied process is able to form a macroporous material with a controlled internal architecture, and this synthesized calcite is non-cytotoxic and facilitate the cell proliferation. Indeed requiring further improvement, the studied calcite is definitely an interesting alternative not only to coralline aragonite but also to calcium phosphate ceramics, particularly in bone sites with the large bone remodelling. Highlights: Black-Right-Pointing-Pointer Macroporous calcite manufacturing with controlled architecture as bone substitute Black-Right-Pointing-Pointer Cytotoxicity: adaptation of the colony-forming method with the target cells: MC3T3-E1 osteoblasts Black-Right-Pointing-Pointer Study of osteoblast proliferation and activity on calcite, HA and TCP.

  18. Evaluation of hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate as a bone graft substitute for posterolateral spinal fusion

    Directory of Open Access Journals (Sweden)

    Bansal Sanjay

    2009-01-01

    Full Text Available Background: Autologous cancellous bone is the most effective biological graft material. However, harvest of autologous bone is associated with significant morbidity. Since porous hydroxyapatite and beta-tricalcium phosphate are biodegradable materials and can be replaced by bone tissue, but it lacks osteogenic property. We conducted a study to assess their use as a scaffold and combine them with bone marrow aspirate for bone regeneration using its osteogenic property for posterolateral spinal fusion on one side and autologous bone graft on the other side and compare them radiologically in terms of graft incorporation and fusion. Materials and Methods: Thirty patients with unstable dorsal and lumbar spinal injuries who needed posterior stabilization and fusion were evaluated in this prospective study from October 2005 to March 2008. The posterior stabilization was done using pedicle screw and rod assembly, and fusion was done using hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate as a bone graft substitute over one side of spine and autologous bone graft obtained from iliac crest over other side of spine. The patients were followed up to a minimum of 12 months. Serial radiographs were done at an interval of 3, 6, and 12 months and CT scan was done at one year follow-up. Graft incorporation and fusion were assessed at each follow-up. The study was subjected to statistical analysis using chi-square and kappa test to assess graft incorporation and fusion. Results: At the end of the study, radiological graft incorporation and fusion was evident in all the patients on the bone graft substitute side and in 29 patients on the autologous bone graft side of the spine ( P > 0.05. One patient showed lucency and breakage of distal pedicle screw in autologous bone graft side. The interobserver agreement (kappa had an average of 0.72 for graft incorporation, 0.75 for fusion on radiographs, and 0.88 for the CT scan findings

  19. Recurrent multilocular mandibular giant cell granuloma in neurofibromatosis type 1: Evidence for second hit mutation of NF1 gene in the jaw lesion and treatment with curettage and bone substitute materials.

    Science.gov (United States)

    Friedrich, Reinhard E; Grob, Tobias J; Hollants, Silke; Zustin, Jozef; Spaepen, Marijke; Mautner, Victor F; Luebke, Andreas M; Hagel, Christian; Legius, Eric; Brems, Hilde

    2016-08-01

    Giant cell granuloma (GCG) of the jaw is a rare, well-known feature of neurofibromatosis type 1 (NF1), an inborn multisystem disorder. Recently, the development of GCG in NF1 was attributed to second hit mutations in the NF1 gene. The treatment of GCG is pragmatic with a preference for local curettage of lytic osseous areas. This report describes the surgical therapy of an NF1-affected female with multilocular mandibular GCG and hypodontia who additionally suffered from a brain tumour and Hashimoto's thyroiditis. Although local recurrence of GCG was noted, augmentation of the curetted cavities with a bone substitute in successive interventions successfully restored the extensive periradicular local defects and stabilised the teeth. A meticulous in vitro study of the GCG specimen revealed a second hit mutation in the NF1 gene in the GCG spindle-cells. This study contributes to the increasing knowledge of the molecular basis for GCG in the jaw of NF1 patients, indicating that it is a neoplasm.

  20. The Role of Resorbable Plate and Artificial Bone Substitute in Reconstruction of Large Orbital Floor Defect

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    Ho Kwon

    2016-01-01

    Full Text Available It is essential to reduce and reconstruct bony defects adequately in large orbital floor fracture and defect. Among many reconstructive methods, alloplastic materials have attracted attention because of their safety and ease of use. We have used resorbable plates combined with artificial bone substitutes in large orbital floor defect reconstructions and have evaluated their long-term reliability compared with porous polyethylene plate. A total of 147 patients with traumatic orbital floor fracture were included in the study. Surgical results were evaluated by clinical evaluations, exophthalmometry, and computed tomography at least 12 months postoperatively. Both orbital floor height discrepancy and orbital volume change were calculated and compared with preoperative CT findings. The average volume discrepancy and vertical height discrepancies were not different between two groups. Also, exophthalmometric measurements were not significantly different between the two groups. No significant postoperative complication including permanent diplopia, proptosis, and enophthalmos was noted. Use of a resorbable plate with an artificial bone substitute to repair orbital floor defects larger than 2.5 cm2 in size yielded long-lasting, effective reconstruction without significant complications. We therefore propose our approach as an effective alternative method for large orbital floor reconstructions.

  1. Bone Material Properties in Osteogenesis Imperfecta.

    Science.gov (United States)

    Bishop, Nick

    2016-04-01

    Osteogenesis imperfecta entrains changes at every level in bone tissue, from the disorganization of the collagen molecules and mineral platelets within and between collagen fibrils to the macroarchitecture of the whole skeleton. Investigations using an array of sophisticated instruments at multiple scale levels have now determined many aspects of the effect of the disease on the material properties of bone tissue. The brittle nature of bone in osteogenesis imperfecta reflects both increased bone mineralization density-the quantity of mineral in relation to the quantity of matrix within a specific bone volume-and altered matrix-matrix and matrix mineral interactions. Contributions to fracture resistance at multiple scale lengths are discussed, comparing normal and brittle bone. Integrating the available information provides both a better understanding of the effect of current approaches to treatment-largely improved architecture and possibly some macroscale toughening-and indicates potential opportunities for alternative strategies that can influence fracture resistance at longer-length scales.

  2. A Bone Sample Containing a Bone Graft Substitute Analyzed by Correlating Density Information Obtained by X-ray Micro Tomography with Compositional Information Obtained by Raman Microscopy

    Directory of Open Access Journals (Sweden)

    Johann Charwat-Pessler

    2015-06-01

    Full Text Available The ability of bone graft substitutes to promote new bone formation has been increasingly used in the medical field to repair skeletal defects or to replace missing bone in a broad range of applications in dentistry and orthopedics. A common way to assess such materials is via micro computed tomography (µ-CT, through the density information content provided by the absorption of X-rays. Information on the chemical composition of a material can be obtained via Raman spectroscopy. By investigating a bone sample from miniature pigs containing the bone graft substitute Bio Oss®, we pursued the target of assessing to what extent the density information gained by µ-CT imaging matches the chemical information content provided by Raman spectroscopic imaging. Raman images and Raman correlation maps of the investigated sample were used in order to generate a Raman based segmented image by means of an agglomerative, hierarchical cluster analysis. The resulting segments, showing chemically related areas, were subsequently compared with the µ-CT image by means of a one-way ANOVA. We found out that to a certain extent typical gray-level values (and the related histograms in the µ-CT image can be reliably related to specific segments within the image resulting from the cluster analysis.

  3. Clinical Application of Antimicrobial Bone Graft Substitute in Osteomyelitis Treatment: A Systematic Review of Different Bone Graft Substitutes Available in Clinical Treatment of Osteomyelitis.

    Science.gov (United States)

    van Vugt, T A G; Geurts, J; Arts, J J

    2016-01-01

    Osteomyelitis is a common occurrence in orthopaedic surgery, which is caused by different bacteria. Treatment of osteomyelitis patients aims to eradicate infection by debridement surgery and local and systemic antibiotic therapy. Local treatment increases success rates and can be performed with different antimicrobial bone graft substitutes. This review is performed to assess the level of evidence of synthetic bone graft substitutes in osteomyelitis treatment. According to the PRISMA statement for reporting systematic reviews, different types of clinical studies concerning treatment of osteomyelitis with bone graft substitutes are included. These studies are assessed on their methodological quality as level of evidence and bias and their clinical outcomes as eradication of infection. In the fifteen included studies, the levels of evidence were weak and in ten out of the fifteen studies there was a moderate to high risk of bias. However, first results of the eradication of infection in these studies showed promising results with their relatively high success rates and low complication rates. Due to the low levels of evidence and high risks of bias of the included studies, these results are inconclusive and no conclusions regarding the performed clinical studies of osteomyelitis treatment with antimicrobial bone graft substitutes can be drawn.

  4. Efficacy of novel synthetic bone substitutes in the reconstruction of large segmental bone defects in sheep tibiae.

    Science.gov (United States)

    Li, Jiao Jiao; Roohani-Esfahani, Seyed-Iman; Dunstan, Colin R; Quach, Terrence; Steck, Roland; Saifzadeh, Siamak; Pivonka, Peter; Zreiqat, Hala

    2016-02-19

    The treatment of large bone defects, particularly those with segmental bone loss, remains a significant clinical challenge as current approaches involving surgery or bone grafting often do not yield satisfactory long-term outcomes. This study reports the evaluation of novel ceramic scaffolds applied as bone graft substitutes in a clinically relevant in vivo model. Baghdadite scaffolds, unmodified or modified with a polycaprolactone coating containing bioactive glass nanoparticles, were implanted into critical-sized segmental bone defects in sheep tibiae for 26 weeks. Radiographic, biomechanical, μ-CT and histological analyses showed that both unmodified and modified baghdadite scaffolds were able to withstand physiological loads at the defect site, and induced substantial bone formation in the absence of supplementation with cells or growth factors. Notably, all samples showed significant bridging of the critical-sized defect (average 80%) with evidence of bone infiltration and remodelling within the scaffold implant. The unmodified and modified baghdadite scaffolds achieved similar outcomes of defect repair, although the latter may have an initial mechanical advantage due to the nanocomposite coating. The baghdadite scaffolds evaluated in this study hold potential for use as purely synthetic bone graft substitutes in the treatment of large bone defects while circumventing the drawbacks of autografts and allografts.

  5. Histological Features and Biocompatibility of Bone and Soft Tissue Substitutes in the Atrophic Alveolar Ridge Reconstruction

    Directory of Open Access Journals (Sweden)

    Carlo Maiorana

    2016-01-01

    Full Text Available The reconstruction of the atrophic alveolar ridges for implant placement is today a common procedure in dentistry daily practice. The surgical reconstruction provides for the optimization of the supporting bone for the implants and a restoration of the amount of keratinized gingiva for esthetic and functional reasons. In the past, tissue regeneration has been performed with autogenous bone and free gingival or connective tissue grafts. Nowadays, bone substitutes and specific collagen matrix allow for a complete restoration of the atrophic ridge without invasive harvesting procedures. A maxillary reconstruction of an atrophic ridge by means of tissue substitutes and its histological features are then presented.

  6. IN VIVO PERFORMANCE OF THE EXPERIMENTAL CHITOSAN BASED BONE SUBSTITUTE--ADVANCED THERAPY MEDICINAL PRODUCT. A STUDY IN SHEEP.

    Science.gov (United States)

    Bojar, Witold; Kucharska, Martyna; Ciach, Tomasz; Paśnik, Iwona; Korobowicz, Elzbieta; Patkowski, Krzysztof; Gruszecki, Tomasz; Szymanowski, Marek; Rzodkiewicz, Przemysław

    2016-01-01

    When evaluating a novel bone substitute material, advanced in vivo testing is an important step in development and safety affirmation. Sheep seems to be a valuable model for human bone turnover and remodeling activity. The experimental material composed with the stem cells is an advanced therapy medicinal product (acc. to EC Regulation 1394/2007). Our research focuses on histological differences in bone formation (guided bone regeneration--GBR) in sheep maxillas after implantation of the new chitosan/tricalcium phosphate/alginate (CH/TCP/Alg) biomaterial in comparison to the commercially available xenogenic bone graft and a/m enhanced with the stem cells isolated from the adipose tissue. Twelve adult female sheep of BCP synthetic line, weighing 60-70 kg were used for the study. The 11 mm diameter defects in maxilla bone were prepared with a trephine bur under general anesthesia and then filled with the bone substitute materials: CH/TCP/Alg, BioOss Collagen, Geistlich AG (BO), CH/TCP/Alg composed with the stem cells (CH/S) or left just with the blood clot (BC). Inbreeding cycle of the animals terminated at 4 months after surgery. Dissected specimens of the maxilla were evaluated histologically and preliminary under microtomography. Histological evaluation showed early new bone formation observed around the experimental biomaterial and commercially available BO. There were no features of purulent inflammation and necrosis, or granulomatous inflammation. Microscopic examination after 4 months following the surgery revealed trabecular bone formation around chitosan based bone graft and xenogenic material with no significant inflammatory response. Different results--no bone recreation were observed for the negative control (BC). In conclusion, the tested materials (CH/TCP/Alg and BO) showed a high degree of biocompatibility and some osteoconductivity in comparison with the control group. Although the handiness, granules size and setting time of CHffCP/Alg may be refined

  7. Novel bone substitute composed of chitosan and strontium-doped α-calcium sulfate hemihydrate: Fabrication, characterisation and evaluation of biocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yirong; Zhou, Yilin [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Yang, Shenyu [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Li, Jiao Jiao [Biomaterials and Tissue Engineering Research Unit, School of AMME, University of Sydney, Sydney, NSW 2006 (Australia); Li, Xue; Ma, Yunfei; Hou, Yilong; Jiang, Nan; Xu, Changpeng; Zhang, Sheng [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Zeng, Rong [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Tu, Mei, E-mail: tumei@jnu.edu.cn [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Yu, Bin, E-mail: yubinol@163.com [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China)

    2016-09-01

    Calcium sulfate is in routine clinical use as a bone substitute, offering the benefits of biodegradability, biocompatibility and a long history of use in bone repair. The osteoconductive properties of calcium sulfate may be further improved by doping with strontium ions. Nevertheless, the high degradation rate of calcium sulfate may impede bone healing as substantial material degradation may occur before the healing process is complete. The purpose of this study is to develop a novel composite bone substitute composed of chitosan and strontium-doped α-calcium sulfate hemihydrate in the form of microcapsules, which can promote osteogenesis while matching the natural rate of bone healing. The developed microcapsules exhibited controlled degradation that facilitated the sustained release of strontium ions. In vitro testing showed that the microcapsules had minimal cytotoxicity and ability to inhibit bacterial growth. In vivo testing in a mouse model showed the absence of genetic toxicity and low inflammatory potential of the microcapsules. The novel microcapsules developed in this study demonstrated suitable degradation characteristics for bone repair as well as favourable in vitro and in vivo behaviour, and hold promise for use as an alternative bone substitute in orthopaedic surgery. - Highlights: • Chitosan + Sr-doped α-calcium sulfate hemihydrate microcapsules were synthesised. • The novel composite microcapsules had potential application as a bone substitute. • The microcapsules showed controlled degradation and release of strontium ions. • The microcapsules showed in vitro biocompatibility by cytotoxicity test. • The microcapsules showed in vivo biocompatibility in a mouse model.

  8. Bone Substitutes for Peri-Implant Defects of Postextraction Implants

    Directory of Open Access Journals (Sweden)

    Pâmela Letícia Santos

    2013-01-01

    Full Text Available Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immediately after tooth extraction, this study aimed to present a literature review about biomaterials surrounding immediate dental implants. The search included 56 articles published from 1969 to 2012. The results were based on data analysis and discussion. It was observed that implant fixation immediately after extraction is a reliable alternative to reduce the treatment length of prosthetic restoration. In general, the biomaterial should be used to increase bone/implant contact and enhance osseointegration.

  9. Design and optimization of a tissue-engineered bone graft substitute

    Science.gov (United States)

    Shimko, Daniel Andrew

    2004-12-01

    formulation, and scaffold material from all preceding studies were combined and a tissue-engineered bone graft was fabricated. The graft was exposed to long-term in vitro culture, and then mechanically evaluated to determine its clinical potential. The studies contained herein constitute the first steps in the conception and development of a viable tissue-engineered bone graft substitute and establish a solid scientific foundation for future in vivo experimentation utilizing this design.

  10. Multifunctional materials for bone cancer treatment

    Directory of Open Access Journals (Sweden)

    Marques C

    2014-05-01

    Full Text Available Catarina Marques,1 José MF Ferreira,1 Ecaterina Andronescu,2 Denisa Ficai,2 Maria Sonmez,3 Anton Ficai21Department of Materials and Ceramics Engineering, Centre for Research in Ceramics and Composite Materials, University of Aveiro, Aveiro, Portugal; 2Faculty of Applied Chemistry and Material Science, University Politehnica of Bucharest, Bucharest, Romania; 3National Research and Development Institute for Textiles and Leather, Bucharest, RomaniaAbstract: The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen–hydroxyapatite composites used for skin and bone cancer treatments. The multifunctionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative, cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin, silver nanoparticles, antibiotics (anthracyclines, geldanamycin, and/or analgesics (ibuprofen, fentanyl. The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies.Keywords: bone graft, cancer, collagen, magnetite, cytostatics, silver

  11. Study on osteopotential activity of Terminalia arjuna bark extract incorporated bone substitute

    Indian Academy of Sciences (India)

    G Krithiga; T Hemalatha; R Deepachitra; Kausik Ghosh; T P Sastry

    2014-10-01

    Bark extract of Terminalia arjuna (TA) possesses potent medical properties and therefore, holds a reputed position in both Ayurvedic and Unani systems of medicine. Bone substitutes play an inevitable role in traumatic bone damages. Growth factors induce osteoinductivity, but suffer from limitations such as high cost and side effects. This study aims to evaluate the osteoinductive potential of bark extract of TA in bone substitutes. Bone substitutes prepared with TA bark extract were characterized for their physicochemical properties. In vitro biomineralization study was carried out using simulated body fluid. Cytotoxicity, alkaline phosphatase activity and mineralization potential were assessed using MG-63 cell lines. Scanning electron microscope revealed apatite formation on the surface after biomineralization. Thermogravimetric analysis showed 15% increase in residual weight by deposition of calcium and phosphate and their presence was identified by energy dispersive analysis. Increased alkaline phosphatase and calcium release was observed in bone substitutes prepared with TA extract compared with control. The functional groups of TA bark extract help in in vitro biomineralization. In MG-63 cells, it showed potential influence in cell differentiation. TA extract may be used as low-cost alternative for growth factors for treatment of fractured bones.

  12. The materials used in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Tereshchenko, V. P., E-mail: tervp@ngs.ru; Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M. [Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Novosibirsk (Russian Federation)

    2015-11-17

    Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers are the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone.

  13. Autologous serum improves bone formation in a primary stable silica-embedded nanohydroxyapatite bone substitute in combination with mesenchymal stem cells and rhBMP-2 in the sheep model

    Directory of Open Access Journals (Sweden)

    Boos AM

    2014-11-01

    Full Text Available Anja M Boos,1,* Annika Weigand,1,* Gloria Deschler,1 Thomas Gerber,2 Andreas Arkudas,1 Ulrich Kneser,1 Raymund E Horch,1 Justus P Beier11Department of Plastic and Hand Surgery, University Hospital of Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg FAU, Erlangen, 2Institute of Physics, University of Rostock, Rostock, Germany *These authors contributed equally to this work Abstract: New therapeutic strategies are required for critical size bone defects, because the gold standard of transplanting autologous bone from an unharmed area of the body often leads to several severe side effects and disadvantages for the patient. For years, tissue engineering approaches have been seeking a stable, axially vascularized transplantable bone replacement suitable for transplantation into the recipient bed with pre-existing insufficient conditions. For this reason, the arteriovenous loop model was developed and various bone substitutes have been vascularized. However, it has not been possible thus far to engineer a primary stable and axially vascularized transplantable bone substitute. For that purpose, a primary stable silica-embedded nanohydroxyapatite (HA bone substitute in combination with blood, bone marrow, expanded, or directly retransplanted mesenchymal stem cells, recombinant human bone morphogenetic protein 2 (rhBMP-2, and different carrier materials (fibrin, cell culture medium, autologous serum was tested subcutaneously for 4 or 12 weeks in the sheep model. Autologous serum lead to an early matrix change during degradation of the bone substitute and formation of new bone tissue. The best results were achieved in the group combining mesenchymal stem cells expanded with 60 µg/mL rhBMP-2 in autologous serum. Better ingrowth of fibrovascular tissue could be detected in the autologous serum group compared with the control (fibrin. Osteoclastic activity indicating an active bone remodeling process was observed after 4 weeks, particularly

  14. Evaluation of Osteoconductive and Osteogenic Potential of a Dentin-Based Bone Substitute Using a Calvarial Defect Model

    Directory of Open Access Journals (Sweden)

    Ibrahim Hussain

    2012-01-01

    Full Text Available The aim of this study was to assess the osteoconductive and osteogenic properties of processed bovine dentin using a robust rabbit calvarial defect model. In total, 16 New Zealand White rabbits were operated to create three circular defects in the calvaria. One defect was left unfilled, one filled with collected autogenous bone, and the third defect was filled with the dentin-based bone substitute. Following surgery and after a healing period of either 1 or 6 weeks, a CT scan was obtained. Following sacrificing, the tissues were processed for histological examination. The CT data showed the density in the area grafted with the dentin-based material was higher than the surrounding bone and the areas grafted with autologous bone after 1 week and 6 weeks of healing. The area left unfilled remained an empty defect after 1 week and 6 weeks. Histological examination of the defects filled with the dentin product after 6 weeks showed soft tissue encapsulation around the dentin particles. It can be concluded that the rabbit calvarial model used in this study is a robust model for the assessment of bone materials. Bovine dentin is a biostable material; however, it may not be suitable for repairing large 4-wall defects.

  15. Sr-substituted bone cements direct mesenchymal stem cells, osteoblasts and osteoclasts fate

    Science.gov (United States)

    Panseri, Silvia; Dapporto, Massimiliano; Tampieri, Anna; Sprio, Simone

    2017-01-01

    Strontium-substituted apatitic bone cements enriched with sodium alginate were developed as a potential modulator of bone cells fate. The biological impact of the bone cement were investigated in vitro through the study of the effect of the nanostructured apatitic composition and the doping of strontium on mesenchymal stem cells, pre-osteoblasts and osteoclasts behaviours. Up to 14 days of culture the bone cells viability, proliferation, morphology and gene expression profiles were evaluated. The results showed that different concentrations of strontium were able to evoke a cell-specific response, in fact an inductive effect on mesenchymal stem cells differentiation and pre-osteoblasts proliferation and an inhibitory effect on osteoclasts activity were observed. Moreover, the apatitic structure of the cements provided a biomimetic environment suitable for bone cells growth. Therefore, the combination of biological features of this bone cement makes it as promising biomaterials for tissue regeneration. PMID:28196118

  16. Structural evaluation and animal implantation of porous eggshell wastederived hydroxyapatite graft as bone substitution

    Directory of Open Access Journals (Sweden)

    Yudha Mathan Sakti Rahadyan Magetsari

    2014-08-01

    Full Text Available The development of hydroxyapatite graft with high economically value is needed for orthopedic practice in developing countries. Eggsell waste is well known as natural substance for calcium resource. It has been used as raw material in producing hydroxyapatite. This study was conducted to synthesize porous hydroxyapatite from eggshell waste and evaluate its activity as bone substitution. The porous hydroxyapatite graft was manufactured from eggshell and sugar as a raw material using hydrothermal process. The porous eggshell waste-derived hydroxyapatite (EW-HAP graft was characterized using X ray difractometer (XRD and analytical scanning electron microscope (SEM and compared with commercial hydroxyapatite (HAP JCPDS 09-432 graft (Bangros® as standard. The porous EW-HAP graft obtained was then implanted on critically sized femoral defects surgically created in the right thigh of male Wistar rats (Rattus norvegicus with Bangros® as control. Radiological examination using XRD and histological examination using hematoxyline-and-eosin staining of the bone femour were performed at 28 days after implantation. The results showed that the XRD pattern for EW-HAP was likely similar with the HAP standard. However, the SEM examination showed that the pasticle size of EW-HAP graft (2.5-3 μm was higher than those HAP standard graft (1.5-2 μm. Radiographs according to the International of Limb Salvage (ISOLS radiological evaluation system between EW-HAP graft (6.1 ± 1.45 and HAP control graft (6.9 ± 2.10 was not significantly different (p>0.05. Moreover, histological examination according to Lane and Shandu scoring system between the both graft (4.0 ± 0.94 versus 4.4 ± 0.92 was also not significantly different (p>0.05. It can be concluded that the structure EW-HAP graft is similar with HAP graft standard. The both grafts have also equal outcome as bone substitution.

  17. Pharmacokinetics of gentamicin eluted from a regenerating bone graft substitute

    DEFF Research Database (Denmark)

    Stravinskas, M; Horstmann, P; Ferguson, J;

    2016-01-01

    in patients treated surgically for chronic corticomedullary osteomyelitis. RESULTS: The release pattern in vitro was comparable with the obtained release in the patient studies. No recurrence was detected in the osteomyelitis group at latest follow-up (minimum 1.5 years). CONCLUSIONS: This new biphasic bone...

  18. Hydroxyapatite reinforced with multi-walled carbon nanotubes and bovine serum albumin for bone substitute applications

    Science.gov (United States)

    Gholami, Fatemeh; Noor, Ahmad-Fauzi Mohd

    2016-12-01

    The similarity of the chemical composition of HA to the mineral phase of bone and its excellent biocompatibility meets the requirement of materials designed for bone substitute purpose. The application of HA in load bearing devices is limited by its poor mechanical properties. CNTs with outstanding stiffness, strength, combined with their small size and large interfacial area, suggest that they may have great potential as a reinforcing agent for HA. This work aims to develop the Hydroxyapatite/Multi-walled Carbon Nanotubes/Bovine Serum Albumin (HA/MWCNTs/BSA) composites with different types of MWCNTs including hydroxylated and carboxylated MWCNTs (MWCNTs-OH, MWCNTs-COOH), and evaluation of mechanical strength and in vitro cellular response of developed composites. HA powder was mixed with de-ionized water, 15 wt.% BSA, and 0.5 wt.% of different MWCNTs* (> 95%), MWCNTs (> 99.9%), MWCNTs-OH (> 99.9%), MWCNTs-COOH (> 99.9%) to produce composites. Among all developed composites, the HA/MWCNTs-COOH/BSA shows the highest compressive strength (29.57 MPa). The cytotoxic effect of HA/MWCNTs-COOH/BSA with different concentrations (6.25 to 200 µg/ml) was evaluated by MTT assay against normal human colon fibroblast (CCD-18Co cell line). At low concentration, all developed composites were found to be non-cytotoxic when treated to the human fibroblast cells and did not elicit cytotoxic effects on cell proliferation and the highest values of cell viability (283%) for the HA/MWCNTs-COOH/BSA composites obtained; whereas when the concentration was increased, the reduction in cell viability was observed. The novel composites showed favorable cytocompatibility with improved compressive strength which make it applicable to use in range of trabecular bone.

  19. Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep.

    Science.gov (United States)

    Ding, Ming; Andreasen, Christina M; Dencker, Mads L; Jensen, Anders E; Theilgaard, Naseem; Overgaard, Søren

    2015-04-01

    Cylindrical critical size defects were created at the distal femoral condyles bilaterally of eight female adult sheep. Titanium implants with 2-mm concentric gaps were inserted and the gaps were filled with one of the four materials: allograft; a synthetic 15-amino acid cell-binding peptide coated hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could be observed in all four groups. Interestingly, the microarchitecture of the ABM/P-15 group was significantly different from the control group. Tissue volume fraction and thickness were significantly greater in the ABM/P-15 group than in the allograft group. Bone formation and bone ingrowth to porous titanium implant were not significantly different among the four groups. The ABM/P-15 group had similar shear mechanical properties on implant fixation as the allograft group. Adding HA/βTCP-PDLLA to ABM/P-15 did not significantly change these parameters. This study revealed that ABM/P-15 had significantly bone formation in concentric gap, and its enhancements on bone formation and implant fixation were at least as good as allograft. It is suggested that ABM/P-15 might be a good alternative biomaterial for bone implant fixation in this well-validated critical-size defect gap model in sheep. Nevertheless, future clinical researches should focus on prospective, randomized, controlled trials in order to fully elucidate whether ABM/P-15 could be a feasible candidate for bone substitute material in orthopedic practices.

  20. A novel injectable, cohesive and toughened Si-HPMC (silanized-hydroxypropyl methylcellulose) composite calcium phosphate cement for bone substitution.

    Science.gov (United States)

    Liu, Weizhen; Zhang, Jingtao; Rethore, Gildas; Khairoun, Khalid; Pilet, Paul; Tancret, Franck; Bouler, Jean-Michel; Weiss, Pierre

    2014-07-01

    This study reports on the incorporation of the self-setting polysaccharide derivative hydrogel (silanized-hydroxypropyl methylcellulose, Si-HPMC) into the formulation of calcium phosphate cements (CPCs) to develop a novel injectable material for bone substitution. The effects of Si-HPMC on the handling properties (injectability, cohesion and setting time) and mechanical properties (Young's modulus, fracture toughness, flexural and compressive strength) of CPCs were systematically studied. It was found that Si-HPMC could endow composite CPC pastes with an appealing rheological behavior at the early stage of setting, promoting its application in open bone cavities. Moreover, Si-HPMC gave the composite CPC good injectability and cohesion, and reduced the setting time. Si-HPMC increased the porosity of CPCs after hardening, especially the macroporosity as a result of entrapped air bubbles; however, it improved, rather than compromised, the mechanical properties of composite CPCs, which demonstrates a strong toughening and strengthening effect. In view of the above, the Si-HPMC composite CPC may be particularly promising as bone substitute material for clinic application.

  1. Maxillary sinus lift with solely autogenous bone compared to a combination of autogenous bone and growth factors or (solely) bone substitutes. A systematic review : a systematic review

    NARCIS (Netherlands)

    Rickert, D.; Slater, J. J. R. Huddleston; Meijer, H. J. A.; Vissink, A.; Raghoebar, G. M.

    2012-01-01

    Literature regarding the outcome of maxillary sinus floor elevation to create sufficient bone fraction to enable implant placement was systematically reviewed. Bone fraction and implant survival rate were assessed to determine whether grafting material or applied growth factor affected bone fraction

  2. Bone graft substitutes and bone morphogenetic proteins for osteoporotic fractures: What is the evidence?

    NARCIS (Netherlands)

    E.M.M. van Lieshout (Esther); V. Alt (Volker)

    2016-01-01

    textabstractDespite improvements in implants and surgical techniques, osteoporotic fractures remain challenging to treat. Among other major risk factors, decreased expression of morphogenetic proteins has been identified for impaired fracture healing in osteoporosis. Bone grafts or bone graft substi

  3. New Bismuth-Substituted Hydroxyapatite Nanoparticles for Bone Tissue Engineering

    Science.gov (United States)

    Ciobanu, Gabriela; Bargan, Ana Maria; Luca, Constantin

    2015-11-01

    New bismuth-substituted hydroxyapatite [Ca10- x Bi x (PO4)6(OH)2 where x = 0-2.5] nanoparticles were synthesized by the co-precipitation method from aqueous solutions. The structural properties of the samples were analyzed by scanning electron microscopy coupled with x-ray analysis, x-ray powder diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller surface area analysis. The results confirm that bismuth ions have been incorporated into the hydroxyapatite lattice. The prepared nanocrystalline powders consisted of hydroxyapatite as single phase with hexagonal structure, crystal sizes smaller than 60 nm and (Bi + Ca)/P atomic ratio of around 1.67. The hydroxyapatite samples doped with Bi have mesoporous textures with pores size of around 2 nm and specific surface area in the range of 12-25 m2/g. The Bi-substituted hydroxyapatite powders are more effective against Gram-negative Escherichia coli bacteria than Gram-positive Staphylococcus aureus bacteria.

  4. The effects of a novel-reinforced bone substitute and Colloss®E on bone defect healing in sheep

    DEFF Research Database (Denmark)

    Ding, Ming; Røjskjaer, Jesper; Cheng, Liming;

    2012-01-01

    Hydroxyappatite-β-tricalciumphosphate (HA/β-TCP) was reinforced with poly(D,L)-lactic acid (PDLLA) to overcome its weak mechanical properties. Two substitutes with porosities of 77% and 81% HA/β-TCP reinforced with 12 wt % PDLLA were tested in compression. The effects of allograft, substitute (HA/β-TCP......, the sheep were sacrificed. Implants with surrounding bone were harvested and sectioned into two parts: one for microcomputed tomography scanning and push-out test, and one for histomorphometry. The 77% HA/β-TCP reinforced with PDLLA had similar mechanical properties to human cancellous bone...... and was significantly stronger than the HA/β-TCP without PDLLA. Microarchitecture of gap mass was significantly changed after implantation for all groups. Allograft had stronger shear mechanical properties than the other three groups, whereas there were no significant differences between the other three groups...

  5. Direct 3D powder printing of biphasic calcium phosphate scaffolds for substitution of complex bone defects.

    Science.gov (United States)

    Castilho, Miguel; Moseke, Claus; Ewald, Andrea; Gbureck, Uwe; Groll, Jürgen; Pires, Inês; Teßmar, Jörg; Vorndran, Elke

    2014-03-01

    The 3D printing technique based on cement powders is an excellent method for the fabrication of individual and complex bone substitutes even in the case of large defects. The outstanding bone remodeling capacity of biphasic calcium phosphates (BCPs) containing hydroxyapatite (HA) as well as tricalcium phosphate (TCP) in varying ratios makes the adaption of powder systems resulting in BCP materials to this fabrication technique a desirable aim. This study presents the synthesis and characterization of a novel powder system for the 3D printing process, intended for the production of complexly shaped BCP scaffolds by a hydraulic setting reaction of calcium carbonate and TCP with phosphoric acid. The HA/TCP ratio in the specimens could be tailored by the calcium/phosphate ratio of the starting powder. The scaffolds could be fabricated with a dimensional accuracy of >96.5% and a minimal macro pore size of 300 µm. Independent of the phase composition the printed specimens showed a microporosity of approximately 68%, while the compressive strength strongly depended on the chemical composition and increased with rising TCP content in the scaffolds to a maximum of 1.81 MPa. Post-treatment of the scaffolds with a polylactic-co-glycolic acid-solution enhanced the mechanical properties by a factor of 8. In vitro studies showed that all BCP scaffolds were cytocompatible and enhanced the cell viability as well as the cell proliferation, as compared with pure TCP. Cell proliferation is even better on BCP when compared to HA and cell viability is in a similar range on these materials.

  6. Injectability of brushite-forming Mg-substituted and Sr-substituted alpha-TCP bone cements.

    Science.gov (United States)

    Pina, S; Torres, P M C; Ferreira, J M F

    2010-02-01

    The influence of magnesium- and strontium-substitutions on injectability and mechanical performance of brushite-forming alpha-TCP cements has been evaluated in the present work. The effects of Mg- and Sr-substitutions on crystalline phase composition and lattice parameters were determined through quantitative X-ray phase analysis and structural Rietveld refinement of the starting calcium phosphate powders and of the hardened cements. A noticeable dependence of injectability on the liquid-to-powder ratio (LPR), smooth plots of extrusion force versus syringe plunger displacement and the absence of filter pressing effects were observed. For LPR values up to 0.36 ml g(-1), the percentage of injectability was always higher and lower for Mg-containing cements and for Sr-containing cements, respectively, while all the pastes could be fully injected for LPR > 0.36 ml g(-1). The hardened cements exhibited relatively high wet compressive strength values (~17-25 MPa) being the Sr- and Mg-containing cements the strongest and the weakest, respectively, holding an interesting promise for uses in trauma surgery such as for filling bone defects and in minimally invasive techniques such as percutaneous vertebroplasty to fill lesions and strengthen the osteoporotic bone.

  7. 21 CFR 872.3930 - Bone grafting material.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3930 Bone grafting material. (a) Identification... “Class II Special Controls Guidance Document: Dental Bone Grafting Material Devices.” (See § 872.1(e) for... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone grafting material. 872.3930 Section...

  8. Bone Substitute Fabrication Based on Dissolution-Precipitation Reactions

    Directory of Open Access Journals (Sweden)

    Kunio Ishikawa

    2010-02-01

    Full Text Available Although block- or granular-type sintered hydroxyapatite are known to show excellent tissue responses and good osteoconductivity, apatite powder elicits inflammatory response. For the fabrication of hydroxyapatite block or granules, sintering is commonly employed. However, the inorganic component of bone and tooth is not high crystalline hydroxyapatite but low crystalline B-type carbonate apatite. Unfortunately, carbonate apatite powder cannot be sintered due to its instability at high temperature. Another method to fabricate apatite block and/or granule is through phase transformation based on dissolution-precipitation reactions using a precursor phase. This reaction basically is the same as a setting and hardening reaction of calcium sulfate or plaster. In this paper, apatite block fabrication methods by phase transformation based on dissolution-precipitation reactions will be discussed, with a focus on the similarity of the setting and hardening reaction of calcium sulfate.

  9. SU-C-213-01: 3D Printed Patient Specific Phantom Composed of Bone and Soft Tissue Substitute Plastics for Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ehler, E; Sterling, D; Higgins, P [University of Minnesota, Minneapolis, MN (United States)

    2015-06-15

    Purpose: 3D printed phantoms constructed of multiple tissue approximating materials could be useful in both clinical and research aspects of radiotherapy. This work describes a 3D printed phantom constructed with tissue substitute plastics for both bone and soft tissue; air cavities were included as well. Methods: 3D models of an anonymized nasopharynx patient were generated for air cavities, soft tissues, and bone, which were segmented by Hounsfield Unit (HU) thresholds. HU thresholds were chosen to define air-to-soft tissue boundaries of 0.65 g/cc and soft tissue-to-bone boundaries of 1.18 g/cc based on clinical HU to density tables. After evaluation of several composite plastics, a bone tissue substitute was identified as an acceptable material for typical radiotherapy x-ray energies, composed of iron and PLA plastic. PET plastic was determined to be an acceptable soft tissue substitute. 3D printing was performed on a consumer grade dual extrusion fused deposition model 3D printer. Results: MVCT scans of the 3D printed heterogeneous phantom were acquired. Rigid image registration of the patient and the 3D printed phantom scans was performed. The average physical density of the soft tissue and bone regions was 1.02 ± 0.08 g/cc and 1.39 ± 0.14 g/cc, respectively, for the patient kVCT scan. In the 3D printed phantom MVCT scan, the average density of the soft tissue and bone was 1.01 ± 0.09 g/cc and 1.44 ± 0.12 g/cc, respectively. Conclusion: A patient specific phantom, constructed of heterogeneous tissue substitute materials was constructed by 3D printing. MVCT of the 3D printed phantom showed realistic tissue densities were recreated by the 3D printing materials. Funding provided by intra-department grant by University of Minnesota Department of Radiation Oncology.

  10. Substitution of dangerous substances and Materials to improve the Working Environment

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    2000-01-01

    Substitution of dangerous substances and Materials as a method to improve the Working Environment - 25 years of Danish experience......Substitution of dangerous substances and Materials as a method to improve the Working Environment - 25 years of Danish experience...

  11. Substituted Borosilicate Glasses with Improved Osteogenic Capacity for Bone Tissue Engineering.

    Science.gov (United States)

    Fernandes, João S; Gentile, Piergiorgio; Crawford, Aileen; Pires, Ricardo A; Hatton, Paul V; Reis, Rui L

    2017-03-27

    Borosilicate bioactive glasses (BBGs) have shown the capacity to promote higher formation of new bone when compared with silicate bioactive glasses. Herein, we assessed the capacity of BBGs to induce osteogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) as a function of their substituted divalent cations (Mg(2+), Ca(2+), Sr(2+)). To this purpose, we synthesized BBG particles by melt quenching. The cell viability, proliferation, and morphology (i.e., PrestoBlue(®), PicoGreen(®), and DAPI and Phalloidin stainings, respectively), as well as protein expression (i.e., alkaline phosphatase, ALP; osteopontin, OP; and osteocalcin, OC), of BM-MSCs in contact with BBGs were evaluated for 21 days. We observed an enhanced expression of bone-specific proteins (ALP, OP, and OC) and high mineralization of BM-MSCs under BBG-Mg and BBG-Sr-conditioned osteogenic media for concentrations of 20 and 50 mg/mL with low cytotoxic effects. Moreover, BBG-Sr, at a concentration of 50 mg/mL, was able to increase the mineralization and expression of the same bone-specific proteins even under basal medium conditions. These results indicated that the proposed BBGs improved osteogenic differentiation of BM-MSCs, therefore showing their potential as relevant biomaterials for bone tissue regeneration, not only by bonding to bone tissue but also by stimulating new bone formation.

  12. In Vitro Evaluation of Nanoscale Hydroxyapatite-Based Bone Reconstructive Materials with Antimicrobial Properties.

    Science.gov (United States)

    Ajduković, Zorica R; Mihajilov-Krstev, Tatjana M; Ignjatović, Nenad L; Stojanović, Zoran; Mladenović-Antić, Snezana B; Kocić, Branislava D; Najman, Stevo; Petrović, Nenad D; Uskoković, Dragan P

    2016-02-01

    In the field of oral implantology the loss of bone tissue prevents adequate patient care, and calls for the use of synthetic biomaterials with properties that resemble natural bone. Special attention is paid to the risk of infection after the implantation of these materials. Studies have suggested that some nanocontructs containing metal ions have antimicrobial properties. The aim of this study was to examine the antimicrobial and hemolytic activity of cobalt-substituted hydroxyapatite nanoparticles, compared to hydroxyapatite and hydroxyapatite/poly-lactide-co-glycolide. The antibacterial effects of these powders were tested against two pathogenic bacterial strains: Escherichia coi (ATCC 25922) and Staphylococcus aureus (ATCC 25923), using the disc diffusion method and the quantitative antimicrobial test in a liquid medium. The quantitative antimicrobial test showed that all of the tested biomaterials have some antibacterial properties. The effects of both tests were more prominent in case of S. aureus than in E coli. A higher percentage of cobalt in the crystal structure of cobalt-substituted hydroxyapatite nanoparticles led to an increased antimicrobial activity. All of the presented biomaterial samples were found to be non-hemolytic. Having in mind that the tested of cobalt-substituted hydroxyapatite (Ca/Co-HAp) material in given concentrations shows good hemocompatibility and antimicrobial effects, along with its previously studied biological properties, the conclusion can be reached that it is a potential candidate that could substitute calcium hydroxyapatite as the material of choice for use in bone tissue engineering and clinical practices in orthopedic, oral and maxillofacial surgery.

  13. Cellular compatibility of improved scaffold material with deproteinized heterogeneous bone

    Institute of Scientific and Technical Information of China (English)

    LIU Lei; PEI Fu-xing; ZHOU Zong-ke; LI Qi-hong

    2007-01-01

    Objective:To study cellular compatibility of improved scaffold material with deproteinized heterogeneous bone and provide experimental basis on choosing the scaffold material in bone tissue engineering.Methods: Bone marrow stromal cells (BMSC) were co-cultured with heterogeneous deproteinized bone in vitro. The contrast phase microscope, scanning electron microscope, MTT assay, flow cytometry were performed and the BGP content and ALP activities were detected in order to observe the cell growth, adhesion in the material, cell cycle and cell viability.Results: The scaffold material of deproteinized heterogeneous bone had no inhibitory effect on cellular proliferation, differentiation and secretion function of BMSCs.Conclusions: The established heterogeneous deproteinized bone has good biocompatibility with BMSCs and is a potentially ideal scaffold material for bone tissue engineering.

  14. Calcium phosphate cements for bone substitution: chemistry, handling and mechanical properties.

    Science.gov (United States)

    Zhang, Jingtao; Liu, Weizhen; Schnitzler, Verena; Tancret, Franck; Bouler, Jean-Michel

    2014-03-01

    Since their initial formulation in the 1980s, calcium phosphate cements (CPCs) have been increasingly used as bone substitutes. This article provides an overview on the chemistry, kinetics of setting and handling properties (setting time, cohesion and injectability) of CPCs for bone substitution, with a focus on their mechanical properties. Many processing parameters, such as particle size, composition of cement reactants and additives, can be adjusted to control the setting process of CPCs, concomitantly influencing their handling and mechanical performance. Moreover, this review shows that, although the mechanical strength of CPCs is generally low, it is not a critical issue for their application for bone repair--an observation not often realized by researchers and clinicians. CPCs with compressive strengths comparable to those of cortical bones can be produced through densification and/or homogenization of the cement matrix. The real limitation for CPCs appears to be their low fracture toughness and poor mechanical reliability (Weibull modulus), which have so far been only rarely studied.

  15. Biodegradable Materials for Bone Repairs: A Review

    Institute of Scientific and Technical Information of China (English)

    Lili Tan; Xiaoming Yu; Peng Wan; Ke Yang

    2013-01-01

    With attractive research and development of biomaterials,more and more opportunities have been brought to the treatments of human tissue repairs.The implant is usually no need to exist in the body accompanied with the recovery or regeneration of the tissue lesions,and the long-term effect of exotic substance to human body should be reduced as lower as possible.For this purpose,biodegradable materials,including polymers,magnesium alloys and ceramics,have attracted much attention for medical applications due to their biodegradable characters in body environment.This paper in turn introduces these three different types of widely studied biodegradable materials as well as their advantages as implants in applications for bone repairs.Relevant history and research progresses are summarized.

  16. Collagen immobilization of multi-layered BCP-ZrO{sub 2} bone substitutes to enhance bone formation

    Energy Technology Data Exchange (ETDEWEB)

    Linh, Nguyen Thuy Ba [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Jang, Dong-Woo [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Lee, Byong-Taek, E-mail: lbt@sch.ac.kr [Department of Regenerative Medicine, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of); Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, Cheonan, 330-090 (Korea, Republic of)

    2015-08-01

    Graphical abstract: - Highlights: • Col-BCP-ZrO. • Collagen fibers were formed and attached firmly on the surface of BCP-ZrO. • Highly interconnected but uniform porosity were obtained. • High biocompatible, strength scaffolds and new bone were evident in Col-BCP-ZrO{sub 2}. - Abstract: A porous microstructure of multi-layered BCP-ZrO{sub 2} bone substitutes was fabricated using the sponge replica method in which the highly interconnected structure was immobilized with collagen via ethyl(dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide crosslinking. Their struts are combined with a three-layered BCP/BCP-ZrO{sub 2}/ZrO{sub 2} microstructure. Collagen fibers were firmly attached to the strut surface of the BCP-ZrO{sub 2} scaffolds. With control of the three-layered microstructure and collagen immobilization, the compressive strength of the scaffolds increased significantly to 6.8 MPa compared to that of the monolithic BCP scaffolds (1.3 MPa). An in vitro study using MTT, confocal observation, and real-time polymer chain reaction analysis demonstrated that the proliferation and differentiation of the pre-osteoblast-like MC3T3-E1 cells was improved due to the collagen incorporation. Remarkable enhancement of bone regeneration was observed without any immunological reaction in the femurs of rabbits during 1 and 5 months of implantation. Furthermore, the interfaces between new bone and the scaffold struts bonded directly without any gaps.

  17. Bone graft materials in fixation of orthopaedic implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

    2013-01-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many...... the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking...... bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA...

  18. Osteogenic cells on bio-inspired materials for bone tissue engineering.

    Science.gov (United States)

    Vagaská, B; Bacáková, L; Filová, E; Balík, K

    2010-01-01

    This article reviews the development of artificial bone substitutes from their older single-phase forms to novel multi-phase composites, mimicking the composition and architecture of natural bone tissue. The new generation of bone implants should be bioactive, i.e. they should induce the desired cellular responses, leading to integration of the material into the natural tissue and stimulating self-healing processes. Therefore, the first part of the review explains the common principles of the cell-material interaction and summarizes the strategies how to improve the biocompatibility and bioactivity of the materials by modifying the physico-chemical properties of the material surface, such as surface chemistry, wettability, electrical charge, rigidity, microroughness and especially nanoroughness. The latter has been shown to stimulate preferentially the growth of osteoblasts in comparison with other competitive cell types, such as fibroblasts, which could prevent fibrous tissue formation upon implantation. The second more specialized part of the review deals with materials suitable for bone contact and substitution, particularly novel polymer-based composites reinforced with fibres or inorganic particles and containing bioactive components, such as crystals of hydroxyapatite or other calcium phosphates, synthetic ligands for cell adhesion receptors or growth factors. Moreover, if they are degradable, they can be gradually replaced with a regenerating tissue.

  19. Bone strength and material properties of the glenoid

    DEFF Research Database (Denmark)

    Frich, Lars Henrik; Jensen, N.C.; Odgaard, A.;

    1997-01-01

    The quality of the glenoid bone is important to a successful total shoulder replacement. Finite element models have been used to model the response of the glenoid bone to an implanted prosthesis. Because very little is known about the bone strength and the material properties at the glenoid, thes...

  20. Performance of broilers fed with snail (Pomacea caniculata meal as substitute to fish meal or meat and bone meal

    Directory of Open Access Journals (Sweden)

    Ulep, LJL.

    1991-01-01

    Full Text Available Snail meal was used as a substitution to fish meat and bone meal in broiler rations. Final weightand feed conversion efficiency of the birds, profit and return on investment differed significantly among treatments. Feed consumption and production costs were comparable. Results show that snail meal can replace fish or meat and bone meal in broiler diets.

  1. Immunohistochemical characterization of wound healing at two different bone graft substitutes.

    Science.gov (United States)

    Sager, M; Ferrari, D; Wieland, M; Dard, M; Becker, J; Schwarz, F

    2012-05-01

    The immunohistochemical characteristics of wound healing following application of a biphasic calcium phosphate or a collagen coated natural bone combined with a native collagen membrane in a dog model was assessed. Standardized buccal dehiscence-type defects were surgically created following implant bed preparation in 6 dogs. Following implant placement, defects were randomly filled with a collagen coated natural bone mineral (GBO), or a biphasic hydroxyapatite/beta tricalcium phosphate (SBC), and covered with a native collagen membrane. After 1, 4, and 9 weeks' submerged healing, dissected blocks were processed for immunohistochemical (collagen type I (CI), osteocalcin (OC), angiogenesis (TG)) analysis. At 1 week, GBO and SBC granules were homogeneously surrounded by a well vascularized, non-mineralized tissue (NMT). CI and OC antigen reactivity was commonly observed adjacent to both bone graft substitutes. At 4 and 9 weeks, SBC and GBO granules were completely integrated into a secondly formed network of spongiosa. At 9 weeks, dissolution of some granules was observed in the SBC group. Adjacent to these granules, NMT was significantly increased and revealed a pronounced CI, OC and TG antigen reactivity. The initial pattern of bone regeneration and graft integration was comparable in both groups; bone remodelling was more pronounced with SBC.

  2. Multifaceted Material Substitution: The Case of NdFeB Magnets, 2010-2015

    Science.gov (United States)

    Smith, Braeton J.; Eggert, Roderick G.

    2016-07-01

    Substitution is an important response for material users when faced with disruption to the availability or price of an essential material. In economic terms, substitution refers to the ability of firms to alter their patterns of material use in response to exogenous market shocks. Substitution comes in different forms which vary from situation to situation. This paper uses expert opinion to identify the specific forms of substitution that occurred in permanent magnets, specifically neodymium-iron-boron magnets, following the significant increase in rare earth prices in 2010-2011. The paper provides a framework for understanding the multifaceted nature of substitution and assesses the relative importance of five different types of substitution. Technology-for-element, grade-for-grade, and system-for-system substitution appear to have been more important than element-for-element and magnet-for-magnet substitution. Cost pass-through and absorption were also important responses.

  3. Coralline hydroxyapatite is a suitable bone graft substitute in an intra-articular goat defect model.

    Science.gov (United States)

    Koëter, S; Tigchelaar, S J; Farla, P; Driessen, L; van Kampen, A; Buma, P

    2009-07-01

    Intra-articular defects can be filled with an autologous bone graft taken from the iliac crest. This can be indicated after trauma or following correcting osteotomy. Patients may encounter donor site morbidity after this procedure. In this in vivo study, we studied if coralline hydroxyapatite (CHA) is a suitable material to replace autologous bone graft to fill a defect in the femoral trochlea of goats. CHA did not evoke any negative reaction in the synovium, and the articular cartilage was comparable to controls. In the bone graft group, we found scattered areas of (enchondral formed) bone. Most bone graft had been resorbed or remodeled, and the scarce remnants were incorporated into new bone. Resorption of CHA was limited or absent and most CHA was surrounded by new bone. In areas with fragmented CHA, close to the joint surface, numerous giant cells were found. The study shows that in this animal model, CHA inserted in a defect that directly communicates with the joint space incorporates into bone. This study did not show any negative effects of CHA in a joint environment.

  4. 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.

  5. Porous calcium polyphosphate bone substitutes: additive manufacturing versus conventional gravity sinter processing-effect on structure and mechanical properties.

    Science.gov (United States)

    Hu, Youxin; Shanjani, Yaser; Toyserkani, Ehsan; Grynpas, Marc; Wang, Rizhi; Pilliar, Robert

    2014-02-01

    Porous calcium polyphosphate (CPP) structures proposed as bone-substitute implants and made by sintering CPP powders to form bending test samples of approximately 35 vol % porosity were machined from preformed blocks made either by additive manufacturing (AM) or conventional gravity sintering (CS) methods and the structure and mechanical characteristics of samples so made were compared. AM-made samples displayed higher bending strengths (≈1.2-1.4 times greater than CS-made samples), whereas elastic constant (i.e., effective elastic modulus of the porous structures) that is determined by material elastic modulus and structural geometry of the samples was ≈1.9-2.3 times greater for AM-made samples. X-ray diffraction analysis showed that samples made by either method displayed the same crystal structure forming β-CPP after sinter annealing. The material elastic modulus, E, determined using nanoindentation tests also showed the same value for both sample types (i.e., E ≈ 64 GPa). Examination of the porous structures indicated that significantly larger sinter necks resulted in the AM-made samples which presumably resulted in the higher mechanical properties. The development of mechanical properties was attributed to the different sinter anneal procedures required to make 35 vol % porous samples by the two methods. A primary objective of the present study, in addition to reporting on bending strength and sample stiffness (elastic constant) characteristics, was to determine why the two processes resulted in the observed mechanical property differences for samples of equivalent volume percentage of porosity. An understanding of the fundamental reason(s) for the observed effect is considered important for developing improved processes for preparation of porous CPP implants as bone substitutes for use in high load-bearing skeletal sites.

  6. Estudio experimental de la osteosustitución con biomateriales cerámicos formulados como cementos óseos Experimental study of the bone substitution with ceramic biomaterials formulated as bone cements

    Directory of Open Access Journals (Sweden)

    E S Sanzana

    2007-01-01

    reabsorption of the materials. Finally, this work concluded that the calcium phosphate bone cements are osteoconductive, osteotransductive and biocompatible materials which behave as bone substitutes.

  7. Biologically inspired rosette nanotubes and nanocrystalline hydroxyapatite hydrogel nanocomposites as improved bone substitutes.

    Science.gov (United States)

    Zhang, Lijie; Rodriguez, Jose; Raez, Jose; Myles, Andrew J; Fenniri, Hicham; Webster, Thomas J

    2009-04-29

    Today, bone diseases such as bone fractures, osteoporosis and bone cancer represent a common and significant public health problem. The design of biomimetic bone tissue engineering materials that could restore and improve damaged bone tissues provides exciting opportunities to solve the numerous problems associated with traditional orthopedic implants. Therefore, the objective of this in vitro study was to create a biomimetic orthopedic hydrogel nanocomposite based on the self-assembly properties of helical rosette nanotubes (HRNs), the osteoconductive properties of nanocrystalline hydroxyapatite (HA), and the biocompatible properties of hydrogels (specifically, poly(2-hydroxyethyl methacrylate), pHEMA). HRNs are self-assembled nanomaterials that are formed from synthetic DNA base analogs in water to mimic the helical nanostructure of collagen in bone. In this study, different geometries of nanocrystalline HA were controlled by either hydrothermal or sintering methods. 2 and 10 wt% nanocrystalline HA particles were well dispersed into HRN hydrogels using ultrasonication. The nanocrystalline HA and nanocrystalline HA/HRN hydrogels were characterized by x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Mechanical testing studies revealed that the well dispersed nanocrystalline HA in HRN hydrogels possessed improved mechanical properties compared to hydrogel controls. In addition, the results of this study provided the first evidence that the combination of either 2 or 10 wt% nanocrystalline HA and 0.01 mg ml(-1) HRNs in hydrogels greatly increased osteoblast (bone-forming cell) adhesion up to 236% compared to hydrogel controls. Moreover, this study showed that HRNs stimulated HA nucleation and mineralization along their main axis in a way that is very reminiscent of the HA/collagen assembly pattern in natural bone. In summary, the presently observed excellent properties of the biomimetic nanocrystalline HA/HRN hydrogel composites

  8. Biologically inspired rosette nanotubes and nanocrystalline hydroxyapatite hydrogel nanocomposites as improved bone substitutes

    Science.gov (United States)

    Zhang, Lijie; Rodriguez, Jose; Raez, Jose; Myles, Andrew J.; Fenniri, Hicham; Webster, Thomas J.

    2009-04-01

    Today, bone diseases such as bone fractures, osteoporosis and bone cancer represent a common and significant public health problem. The design of biomimetic bone tissue engineering materials that could restore and improve damaged bone tissues provides exciting opportunities to solve the numerous problems associated with traditional orthopedic implants. Therefore, the objective of this in vitro study was to create a biomimetic orthopedic hydrogel nanocomposite based on the self-assembly properties of helical rosette nanotubes (HRNs), the osteoconductive properties of nanocrystalline hydroxyapatite (HA), and the biocompatible properties of hydrogels (specifically, poly(2-hydroxyethyl methacrylate), pHEMA). HRNs are self-assembled nanomaterials that are formed from synthetic DNA base analogs in water to mimic the helical nanostructure of collagen in bone. In this study, different geometries of nanocrystalline HA were controlled by either hydrothermal or sintering methods. 2 and 10 wt% nanocrystalline HA particles were well dispersed into HRN hydrogels using ultrasonication. The nanocrystalline HA and nanocrystalline HA/HRN hydrogels were characterized by x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Mechanical testing studies revealed that the well dispersed nanocrystalline HA in HRN hydrogels possessed improved mechanical properties compared to hydrogel controls. In addition, the results of this study provided the first evidence that the combination of either 2 or 10 wt% nanocrystalline HA and 0.01 mg ml-1 HRNs in hydrogels greatly increased osteoblast (bone-forming cell) adhesion up to 236% compared to hydrogel controls. Moreover, this study showed that HRNs stimulated HA nucleation and mineralization along their main axis in a way that is very reminiscent of the HA/collagen assembly pattern in natural bone. In summary, the presently observed excellent properties of the biomimetic nanocrystalline HA/HRN hydrogel composites

  9. Biologically inspired rosette nanotubes and nanocrystalline hydroxyapatite hydrogel nanocomposites as improved bone substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lijie; Webster, Thomas J [Division of Engineering, Brown University, 182 Hope Street, Providence, RI 02912 (United States); Rodriguez, Jose; Raez, Jose; Myles, Andrew J; Fenniri, Hicham [National Institute for Nanotechnology and Department of Chemistry, University of Alberta, 11421 Saskatchewan Drive, Edmonton, AB, T6G 2M9 (Canada)], E-mail: hicham.fenniri@ualberta.ca, E-mail: thomas_webster@brown.edu

    2009-04-29

    Today, bone diseases such as bone fractures, osteoporosis and bone cancer represent a common and significant public health problem. The design of biomimetic bone tissue engineering materials that could restore and improve damaged bone tissues provides exciting opportunities to solve the numerous problems associated with traditional orthopedic implants. Therefore, the objective of this in vitro study was to create a biomimetic orthopedic hydrogel nanocomposite based on the self-assembly properties of helical rosette nanotubes (HRNs), the osteoconductive properties of nanocrystalline hydroxyapatite (HA), and the biocompatible properties of hydrogels (specifically, poly(2-hydroxyethyl methacrylate), pHEMA). HRNs are self-assembled nanomaterials that are formed from synthetic DNA base analogs in water to mimic the helical nanostructure of collagen in bone. In this study, different geometries of nanocrystalline HA were controlled by either hydrothermal or sintering methods. 2 and 10 wt% nanocrystalline HA particles were well dispersed into HRN hydrogels using ultrasonication. The nanocrystalline HA and nanocrystalline HA/HRN hydrogels were characterized by x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Mechanical testing studies revealed that the well dispersed nanocrystalline HA in HRN hydrogels possessed improved mechanical properties compared to hydrogel controls. In addition, the results of this study provided the first evidence that the combination of either 2 or 10 wt% nanocrystalline HA and 0.01 mg ml{sup -1} HRNs in hydrogels greatly increased osteoblast (bone-forming cell) adhesion up to 236% compared to hydrogel controls. Moreover, this study showed that HRNs stimulated HA nucleation and mineralization along their main axis in a way that is very reminiscent of the HA/collagen assembly pattern in natural bone. In summary, the presently observed excellent properties of the biomimetic nanocrystalline HA/HRN hydrogel

  10. Biological responses of brushite-forming Zn- and ZnSr- substituted beta-tricalcium phosphate bone cements.

    Science.gov (United States)

    Pina, S; Vieira, S I; Rego, P; Torres, P M C; da Cruz e Silva, O A B; da Cruz e Silva, E F; Ferreira, J M F

    2010-09-07

    The core aim of this study was to investigate zinc (Zn)- and zinc and strontium (ZnSr)-containing brushite-forming beta-tricalcium phosphate (TCP) cements for their effects on proliferation and differentiation of osteoblastic-like cells (MC3T3-E1 cell line) as well as for their in vivo behaviour in trabecular bone cylindrical defects in a pilot study. In vitro proliferation and maturation responses of MC3T3-E1 osteoblastic-like cells to bone cements were studied at the cellular and molecular levels. The Zn- and Sr-containing brushite cements were found to stimulate pre-osteoblastic proliferation and osteoblastic maturation. Indeed, MC3T3-E1 cells exposed to the powdered cements had increased proliferative rates and higher adhesiveness capacity, in comparison to control cells. Furthermore, they exhibited higher alkaline phosphatase (ALP) activity and increased Type-I collagen secretion and fibre deposition into the extracellular matrix. Proliferative and collagen deposition properties were more evident for cells grown in cements doped with Sr. The in vivo osteoconductive propertiesof the ZnCPC and ZnSrCPC cements were also pursued. Histological and histomorphometric analyses were performed at 1 and 2 months after implantation, using carbonated apatite cement (Norian SRS) as control. There was no evidence of cement-induced adverse foreign body reactions, and furthermore ZnCPC and ZnSrCPC cements revealed better in vivo performance in comparison to the control apatite cement. Additionally, the presence of both zinc and strontium resulted in the highest rate of new bone formation. These novel results indicate that the investigated ZnCPC and ZnSrCPC cements are both biocompatible and osteoconductive, being good candidate materials to use as bone substitutes.

  11. Biological responses of brushite-forming Zn- and ZnSr- substituted beta-tricalcium phosphate bone cements

    Directory of Open Access Journals (Sweden)

    S Pina

    2010-09-01

    Full Text Available The core aim of this study was to investigate zinc (Zn- and zinc and strontium (ZnSr-containing brushite-forming beta-tricalcium phosphate (TCP cements for their effects on proliferation and differentiation of osteoblastic-like cells (MC3T3-E1 cell line as well as for their in vivo behaviour in trabecular bone cylindrical defects in a pilot study. In vitro proliferation and maturation responses of MC3T3-E1 osteoblastic-like cells to bone cements were studied at the cellular and molecular levels. The Zn- and Sr-containing brushite cements were found to stimulate pre-osteoblastic proliferation and osteoblastic maturation. Indeed, MC3T3-E1 cells exposed to the powdered cements had increased proliferative rates and higher adhesiveness capacity, in comparison to control cells. Furthermore, they exhibited higher alkaline phosphatase (ALP activity and increased Type-I collagen secretion and fibre deposition into the extracellular matrix. Proliferative and collagen deposition properties were more evident for cells grown in cements doped with Sr. The in vivo osteoconductive propertiesof the ZnCPC and ZnSrCPC cements were also pursued. Histological and histomorphometric analyses were performed at 1 and 2 months after implantation, using carbonated apatite cement (Norian SRS® as control. There was no evidence of cement-induced adverse foreign body reactions, and furthermore ZnCPC and ZnSrCPC cements revealed better in vivo performance in comparison to the control apatite cement. Additionally, the presence of both zinc and strontium resulted in the highest rate of new bone formation. These novel results indicate that the investigated ZnCPC and ZnSrCPC cements are both biocompatible and osteoconductive, being good candidate materials to use as bone substitutes.

  12. Development and characterization of novel alginate-based hydrogels as vehicles for bone substitutes.

    Science.gov (United States)

    Morais, D S; Rodrigues, M A; Silva, T I; Lopes, M A; Santos, M; Santos, J D; Botelho, C M

    2013-06-05

    In this work three different hydrogels were developed to associate, as vehicles, with the synthetic bone substitute GR-HAP. One based on an alginate matrix (Alg); a second on a mixture of alginate and chitosan (Alg/Ch); and a third on alginate and hyaluronate (Alg/HA), using Ca(2+) ions as cross-linking agents. The hydrogels, as well as the respective injectable bone substitutes (IBSs), were fully characterized from the physical-chemical point of view. Weight change studies proved that all hydrogels were able to swell and degrade within 72 h at pH 7.4 and 4.0, being Alg/HA the hydrogel with the highest degradation rate (80%). Rheology studies demonstrated that all hydrogels are non-Newtonian viscoelastic fluids, and injectability tests showed that IBSs presented low maximum extrusion forces, as well as quite stable average forces. In conclusion, the studied hydrogels present the necessary features to be successfully used as vehicles of GR-HAP, particularly the hydrogel Alg/HA.

  13. Bone graft substitutes for the treatment of traumatic fractures of the extremities [Knochenersatzmaterialien zur Behandlung von traumatischen Frakturen der Extremitäten

    Directory of Open Access Journals (Sweden)

    Hagen, Anja

    2012-06-01

    Full Text Available [english] Bone graft substitutes are increasingly being used as supplements to standard care or as alternative to bone grafts in the treatment of traumatic fractures.The efficacy and cost-effectiveness of bone graft substitutes for the treatment of traumatic fractures as well as the ethical, social and legal implications of their use are the main research questions addressed.A systematic literature search was conducted in electronic medical databases (MEDLINE, EMBASE etc. in December 2009. Randomised controlled trials (RCT, where applicable also containing relevant health economic evaluations and publications addressing the ethical, social and legal aspects of using bone graft substitutes for fracture treatment were included in the analysis. After assessment of study quality the information synthesis of the medical data was performed using metaanalysis, the synthesis of the health economic data was performed descriptively. 14 RCT were included in the medical analysis, and two in the heath economic evaluation. No relevant publications on the ethical, social and legal implications of the bone graft substitute use were found. In the RCT on fracture treatment with bone morphogenetic protein-2 (BMP-2 versus standard care without bone grafting (RCT with an elevd high risk of bias there was a significant difference in favour of BMP-2 for several outcome measures. The RCT of calcium phosphate (CaP cement and bone marrow-based composite materials versus autogenous bone grafts (RCT with a high risk of bias revealed significant differences in favour of bone graft substitutes for some outcome measures. Regarding the other bone graft substitutes, almost all comparisons demonstrated no significant difference.The use of BMP-2 in addition to standard care without bone grafting led in the study to increased treatment costs considering all patients with traumatic open fractures. However, cost savings through the additional use of BMP-2 were calculated in a

  14. HBM Mice Have Altered Bone Matrix Composition and Improved Material Toughness.

    Science.gov (United States)

    Ross, Ryan D; Mashiatulla, Maleeha; Acerbo, Alvin S; Almer, Jonathan D; Miller, Lisa M; Johnson, Mark L; Sumner, D Rick

    2016-10-01

    The G171V mutation in the low-density lipoprotein receptor-related protein 5 (LRP5) leads to a high bone mass (HBM) phenotype. Studies using HBM transgenic mouse models have consistently found increased bone mass and whole-bone strength, but little attention has been paid to the composition of the bone matrix. The current study sought to determine if the cortical bone matrix composition differs in HBM and wild-type mice and to determine how much of the variance in bone material properties is explained by variance in matrix composition. Consistent with previous studies, HBM mice had greater cortical area, moment of inertia, ultimate force, bending stiffness, and energy to failure than wild-type animals. The increased energy to failure was primarily caused by a large increase in post-yield behavior, with no difference in pre-yield behavior. The HBM mice had increased mineral-to-matrix and collagen cross-link ratios, and decreased crystallinity, carbonate, and acid phosphate substitution as measured by Fourier transform infrared microspectroscopy, but no differences in crystal length, intra-fibular strains, and mineral spacing compared to wild-type controls, as measured by X-ray scattering. The largest between genotype difference in material properties was a twofold increase in the modulus of toughness in HBM mice. Step-wise regression analyses showed that the specific matrix compositional parameters most closely associated with material properties varied between the wild-type and HBM genotypes. Although the mechanisms controlling the paradoxical combination of more mineralized yet tougher bone in HBM mice remain to be fully explained, the findings suggest that LRP5 represents a target to not only build bone mass but also to improve bone quality.

  15. Effect of rare earth substitution in cobalt ferrite bulk materials

    Energy Technology Data Exchange (ETDEWEB)

    Bulai, G., E-mail: georgiana.bulai@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bd. Carol I, nr. 11, 700506 Iasi (Romania); Diamandescu, L. [National Institute of Material Physics, P.O. Box MG-7, 07125 Bucharest (Romania); Dumitru, I.; Gurlui, S. [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bd. Carol I, nr. 11, 700506 Iasi (Romania); Feder, M. [National Institute of Material Physics, P.O. Box MG-7, 07125 Bucharest (Romania); Caltun, O.F. [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bd. Carol I, nr. 11, 700506 Iasi (Romania)

    2015-09-15

    The study was focused on the influence of small amounts of rare earth (RE=La, Ce, Sm, Gd, Dy, Ho, Er, Yb) addition on the microstructure, phase content and magnetic properties of cobalt ferrite bulk materials. The X-Ray diffraction measurements confirmed the formation of the spinel structure but also the presence of secondary phases of RE oxides or orthoferrite in small percentages (up to 3%). Density measurements obtained by Archimedes method revealed a ~1 g cm{sup −3} decrease for the RE doped cobalt ferrite samples compared with stoichiometric one. Both the Mössbauer and Fourier Transform Infrared Spectrocopy analysis results confirmed the formation of the spinel phase. The saturation magnetization and coercive field values of the doped samples obtained by Vibrating Sample Magnetometry were close to those of the pure cobalt ferrite. For magnetostrictive property studies the samples were analyzed using the strain gauge method. Higher maximum magnetostriction coefficients were found for the Ho, Ce, Sm and Yb doped cobalt ferrite bulk materials as related to the stoichiometric CoFe{sub 2}O{sub 4} sample. Moreover, improved strain derivative was observed for these samples but at higher magnetic fields due to the low increase of the coercive field values for doped samples. - Highlights: • Substitution by a large number of rare earth elements was investigated. • First reported results on magnetostriction measurements of RE doped cobalt ferrite. • The doped samples presented an increased porosity and a decreased grain size. • Increased magnetostrctive response was observed for several doped samples.

  16. Effects of zinc-substituted nano-hydroxyapatite coatings on bone integration with implant surfaces

    Institute of Scientific and Technical Information of China (English)

    Shi-fang ZHAO; Wen-jing DONG; Qiao-hong JIANG; Fu-ming HE; Xiao-xiang WANG; Guo-li YANG

    2013-01-01

    Objective:The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite (Zn-HA) coating,applied by an electrochemical process,on implant osseointegraton in a rabbit model.Methods:A Zn-HA coating or an HA coating was deposited using an electrochemical process.Surface morphology was examined using field-emission scanning electron microscopy.The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR).A total of 78 implants were inserted into femurs and tibias of rabbits.After two,four,and eight weeks,femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque (RTQ) tests.Results:Rod-like HA crystals appeared on both implant surfaces.The dimensions of the Zn-HA crystals seemed to be smaller than those of HA.XRD patterns showed that the peaks of both coatings matched well with standard HA patterns.FTIR spectra showed that both coatings consisted of HA crystals.The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks (P<0.05),the bone to implant contact (BIC) at four weeks (P<0.05),and RTQ values after four and eight weeks (P<0.05).Conclusions:The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.

  17. Chemistry of environmental materials. 3. Substitutive materials of asbestos; Kankyo zairyo no kagaku. Asbesto daitai zairyo

    Energy Technology Data Exchange (ETDEWEB)

    Fujiki, Y. [Kubota Corp., Osaka (Japan)

    1996-03-01

    This paper outlines the synthesis and characteristics of substitutive materials of asbestos. Oxide system fibers are used as substitutes and classified into natural and synthetic fibers. As natural substitute, wollastonite fiber is used, while as synthetic substitute, silicate system, alumina system, zirconia system and potassium titanate system fibers are used. Wollastonite distributes in regional metamorphic rock and contact metamorphic zone between limestone and plutonic rock, and is used as heat insulator and adiabator. Silicate system fiber includes glass fiber, quartz fiber and silica fiber, while alumina system fiber includes alumina/silica fiber and alumina fiber. Glass fiber is composed of non-alkaline boro-silicate glass and classified into lint and staple. As fibers similar to glass staple, rock wool and slag wool are used. Only slag wool is produced in Japan because of its lower cost and higher qualitative stability than those of glass wool. Potassium titanate system fiber offers excellent heat resistance, thermal insulation and frictional resistance. 18 refs., 13 figs., 9 tabs.

  18. Impacts of Vehicle Weight Reduction via Material Substitution on Life-Cycle Greenhouse Gas Emissions.

    Science.gov (United States)

    Kelly, Jarod C; Sullivan, John L; Burnham, Andrew; Elgowainy, Amgad

    2015-10-20

    This study examines the vehicle-cycle and vehicle total life-cycle impacts of substituting lightweight materials into vehicles. We determine part-based greenhouse gas (GHG) emission ratios by collecting material substitution data and evaluating that alongside known mass-based GHG ratios (using and updating Argonne National Laboratory's GREET model) associated with material pair substitutions. Several vehicle parts are lightweighted via material substitution, using substitution ratios from a U.S. Department of Energy report, to determine GHG emissions. We then examine fuel-cycle GHG reductions from lightweighting. The fuel reduction value methodology is applied using FRV estimates of 0.15-0.25, and 0.25-0.5 L/(100km·100 kg), with and without powertrain adjustments, respectively. GHG breakeven values are derived for both driving distance and material substitution ratio. While material substitution can reduce vehicle weight, it often increases vehicle-cycle GHGs. It is likely that replacing steel (the dominant vehicle material) with wrought aluminum, carbon fiber reinforced plastic (CRFP), or magnesium will increase vehicle-cycle GHGs. However, lifetime fuel economy benefits often outweigh the vehicle-cycle, resulting in a net total life-cycle GHG benefit. This is the case for steel replaced by wrought aluminum in all assumed cases, and for CFRP and magnesium except for high substitution ratio and low FRV.

  19. APPLICATION OF A BIODEGRADABLE MATERIAL FOR BONE REPLACEMENT IN TRAUMATOLOGY

    Directory of Open Access Journals (Sweden)

    T. V. Druzhinina

    2014-01-01

    Full Text Available 20 men (medium age (31.5 ± 13.5 years were studied. All patients underwent arthroscopic auditing plastic anterior cruciate ligament of the knee. Osteoregeneration dynamics were determined by biochemical testing of blood serum and X-ray computed tomography (CT of the fracture in 1–4 months after surgery. As a result, an estimation of the bone tissue reparative regeneration according to CT data in 10 patients with a defect of the patella, treated with the material is provided. The obtained results of the clinical study indicate the reparative effect of the biodegradable material for bone replacing on bone regeneration

  20. Calcium Phosphates as Bone Substitute for Dental Implant Surgery%口腔种植中磷酸钙类骨替代材料的应用

    Institute of Scientific and Technical Information of China (English)

    陈卓凡; 刘泉; Matinlinna JP

    2016-01-01

    在口腔种植手术中,磷酸钙类的骨替代材料已经被广泛应用于骨修复、骨增量和重建.了解此类材料的基础性能,对于一个种植医生来说是非常重要的,但初学者可能无法完全掌握.因此,本文对异种来源和人工合成的两类骨移植材料的特点,进行了全面总结评述.尽管部分材料显示了优良的生物效应,但目前磷酸钙类的骨替代材料仍有巨大的改进提升空间.%Calcium phosphate-based bone substitutes have been widely used for bone repair, augmentation and recon-struction in dental implant surgery. The basic properties of such materials are undoubtedly of importance, but may not be comprehensively understood by practitioners. Hence, the properties of two major groups, xenogenic and alloplastic grafting materials, have been reviewed and discussed in this article. It appears that more work is needed to improve the perfor-mance of the current calcium phosphate-based bone substitutes, although some of them have been showing outstanding bi-ological response.

  1. Conversion of sea urchin spines to Mg-substituted tricalcium phosphate for bone implants.

    Science.gov (United States)

    Vecchio, Kenneth S; Zhang, Xing; Massie, Jennifer B; Wang, Mark; Kim, Choll W

    2007-09-01

    The skeleton of sea urchin spines is composed of large single crystals of Mg-rich calcite, which have smooth, continuously curved surfaces and form a three-dimensional fenestrated mineral network. Spines of the echinoids Heterocentrotus trigonarius and Heterocentrotus mammillatus were converted by the hydrothermal reaction at 180 degrees C to bioresorbable Mg-substituted tricalcium phosphate (beta-TCMP). Due to the presence of Mg in the calcite lattice, conversion to beta-TCMP occurs preferentially to hydroxyapatite formation. The converted beta-TCMP still maintains the three-dimensional interconnected porous structures of the original spine. The main conversion mechanism is the ion-exchange reaction, although there is also a dissolution-reprecipitation process that forms some calcium phosphate precipitates on the surfaces of the spine network. The average fracture strength of urchin spines and converted spines (beta-TCMP) in the compression tests are 42 and 23MPa, respectively. In vivo studies using a rat model demonstrated new bone growth up to and around the beta-TCMP implants after implantation in rat femoral defects for 6 weeks. Some new bone was found to migrate through the spine structural pores, starting from the outside of the implant through the pores at the edge of the implants. These results indicate good bioactivity and osteoconductivity of the porous beta-TCMP implants.

  2. Bone graft materials in fixation of orthopaedic implants in sheep.

    Science.gov (United States)

    Babiker, Hassan

    2013-07-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many orthopaedic procedures, whereas allograft is the gold standard by replacement of extensive bone loss. However, the use of autograft is associated with donor site morbidity, especially chronic pain. In addition, the limited supply is a significant clinical challenge. Limitations in the use of allograft include the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking skeletal bones. The osteoconductive properties of the composite might be improved by adding bone marrow aspirate (BMA), which can be harvested during surgery. Other alternatives to bone graft are demineralised bone matrix (DBM) and human cancellous bone (CB). DBM is prepared by acid extraction of human bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA/Collagen composite alone and in combination with BMA on the early fixation of porous coated titanium implants. In addition, the study compares also the effect of autograft with the gold standard allograft. By using a sheep model, the implants were inserted in the trabecular bone of femoral condyles. The test biomaterials were placed in a well defined peri-implant gap. After the observation period, the bone-implant specimens were harvested and evaluated mechanically by a destructive push

  3. Preclinical investigation of an innovative magnesium-based bone graft substitute for potential orthopaedic applications

    Directory of Open Access Journals (Sweden)

    Chen Liu

    2014-07-01

    Full Text Available Degradable or corrosive biometal is an attractive research and development (R&D area in clinical orthopaedics. This study was designed to investigate biomechanical and biological properties of magnesium (Mg and strontium (Sr with a focus on Mg-based metals, including pure Mg and Mg–xwt% Sr (x = 0.25, x = 1.0, x = 1.5, x = 2.5 alloys, as potential bone graft substitutes in respect to their mechanical strength, corrosion resistance, and cytocompatibility for further optimization and establishing indications for relevant in vivo applications. Our data showed that the tensile and compressive strength increased with addition of Sr because of the Mg17Sr2 precipitation strengthen. Compared with commercially used bone graft substitutes, the mechanical properties of Mg–Sr alloys were close to those of cortical bone, and the compressive strength could reach 300 MPa, suggesting its potential application for load-bearing bone as bone defect filler. The corrosion rates of Mg–xwt% Sr alloys were controlled in the range of 0.05–0.07 mm/y, indicating feasibility of bone grafting and the in situ bone repair process. Moreover, Mg–Sr alloys also exhibit good cytocompatibility and antibacterial properties. Our innovation presented in this work supported in vivo clinical indication-based assessment of biodegradable Mg-based metals that could be potential candidates for bone graft substitutes for future orthopaedic applications.

  4. Nano-material aspects of shock absorption in bone joints.

    Science.gov (United States)

    Tributsch, H; Copf, F; Copf, P; Hindenlang, U; Niethard, F U; Schneider, R

    2010-01-01

    This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three-dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones.

  5. Bioreactor activated graft material for early implant fixation in bone

    DEFF Research Database (Denmark)

    Snoek Henriksen, Susan; Ding, Ming; Overgaard, Søren

    2011-01-01

    Introduction The combined incubation of a composite scaffold with bone marrow stromal cells in a perfusion bioreactor could make up a novel hybrid graft material with optimal properties for early fixation of implant to bone. The aim of this study was to create a bioreactor activated graft (BAG......) material, which could induce early implant fixation similar to that of allograft. Two porous scaffold materials incubated with cells in a perfusion bioreactor were tested in this study. Methods and Materials Two groups of 8 skeletally mature female sheep were anaesthetized before aspiration of bone marrow...... Technological Institute, Denmark). The granules were coated with poly-lactic acid (PLA) 12%, in order to increase the mechanical strength of the material (Phusis, France). Scaffold granules (Ø~900-1400 µm, 80% porosity) in group 2 consisted of pure HA/β-TCP (FinCeramica, Italy). For both groups, cells were...

  6. Fibrin gel-immobilized primary osteoblasts in calcium phosphate bone cement: in vivo evaluation with regard to application as injectable biological bone substitute.

    Science.gov (United States)

    Kneser, U; Voogd, A; Ohnolz, J; Buettner, O; Stangenberg, L; Zhang, Y H; Stark, G B; Schaefer, D J

    2005-01-01

    Osteogenic injectable bone substitutes may be useful for many applications. We developed a novel injectable bone substitute based on osteoblast-fibrin glue suspension and calcium phosphate bone cement (BC). Human osteoblasts were isolated from trabecular bone samples and cultured under standard conditions. Osteoblasts were suspended in fibrinogen solution (FS). BC was cured with thrombin solution. 8 x 4 mm injectable bone discs were prepared using silicon molds and a custom-made applicator device. Discs containing BC, BC/FS, or BC/FS/osteoblasts were implanted subcutaneously into athymic nude mice. After 3, 9 and 24 weeks, specimens were explanted and subjected to morphologic and biomechanical evaluation. In vitro fibrin gel-embedded osteoblasts displayed a differentiated phenotype as evidenced by alkaline phosphatase, collagen type 1 and von Kossa stains. A proportion of osteoblasts appeared morphologically intact over a 3-day in vitro period following application into the BC. BC/FS and BC/FS/osteoblast discs were sparsely infiltrated with vascularized connective tissue. There was no bone formation in implants from all groups. However, positive von Kossa staining only in BC/FS/osteoblast groups suggests engraftment of at least some of the transplanted cells. Biomechanical evaluation demonstrated initial stability of the composites. Young's modulus and maximal load did not differ significantly in the BC/FS and BC/FS/osteoblast groups. The practicability of osteoblast-containing injectable bone could be demonstrated. The dense microstructure and the suboptimal initial vascularization of the composites may explain the lack of bone formation. Modifications with regard to enhanced osteoblast survival are mandatory for a possible application as injectable osteogenic bone replacement system.

  7. Material Properties of the Mandibular Trabecular Bone

    Directory of Open Access Journals (Sweden)

    Éva Lakatos

    2014-01-01

    Full Text Available The present paper introduces a numerical simulation aided, experimental method for the measurement of Young’s modulus of the trabecular substance in the human mandible. Compression tests were performed on fresh cadaveric samples containing trabecular bone covered with cortical layer, thus avoiding the destruction caused by the sterilization, preservation, and storage and the underestimation of the stiffness resulting from the individual failure of the trabeculae cut on the surfaces. The elastic modulus of the spongiosa was determined by the numerical simulation of each compression test using a specimen specific finite element model of each sample. The received mandibular trabecular bone Young’s modulus values ranged from 6.9 to 199.5 MPa.

  8. [Hydroxyapatite bone substitute (Ostim) in sinus floor elevation. Maxillary sinus floor augmentation: bone regeneration by means of a nanocrystalline in-phase hydroxyapatite (Ostim)].

    Science.gov (United States)

    Smeets, Ralf; Grosjean, Maurice B; Jelitte, Gerd; Heiland, Max; Kasaj, Adrian; Riediger, Dieter; Yildirim, Murat; Spiekermann, Hubertus; Maciejewski, Oliver

    2008-01-01

    The range of bone regeneration materials suitable for maxillar bone augmentation has increased steadily in the past few years and there is now a wide variety of materials being used. In the present case report, we analyzed the state of bone regeneration after sinus floor augmentation using a nanocrystalline in-phase synthetic anorganic hydroxyapatite bone grafting material (Ostim). A 60-year-old female patient underwent maxillary sinus floor elevation and the cavity was filled with Ostim three years before. Actually, she presented herself with loosening of the dental implant at position 17, as a result of parafunction. At the time of the insertion of a second implant at position 17, bone samples were taken by using a trepan drilling device from the previously augmented area. These samples were analyzed histologically to determine the extent of bone remodeling around the deposits of Ostim. We found that the Ostim deposits were surrounded largely by woven bone and, in parts, by lamellar bone and had facilitated osteoconductive bone regeneration. The adjacent implant, at position 16, which beared a crown exposed to proper biting forces without parafunction, showed proper clinical and radiological characteristics of complete and firm integration into the area which was also filled with Ostim three years ago. We conclude that the use of the nanocrystalline hydroxyapatite Ostim with its stable volume properties appears to be suitable for maxillary sinus floor augmentation. Furthermore, we even found osteoconductive bone regeneration under Ostim near the site of the loosened implant.

  9. Impacts of Vehicle Weight Reduction via Material Substitution on Life-Cycle Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Jarod C.; Sullivan, John L.; Burnham, Andrew; Elgowainy, Amgad

    2015-10-20

    This study examines the vehicle-cycle impacts associated with substituting lightweight materials for those currently found in light-duty passenger vehicles. We determine part-based energy use and greenhouse gas (GHG) emission ratios by collecting material substitution data from both the literature and automotive experts and evaluating that alongside known mass-based energy use and GHG emission ratios associated with material pair substitutions. Several vehicle parts, along with full vehicle systems, are examined for lightweighting via material substitution to observe the associated impact on GHG emissions. Results are contextualized by additionally examining fuel-cycle GHG reductions associated with mass reductions relative to the baseline vehicle during the use phase and also determining material pair breakeven driving distances for GHG emissions. The findings show that, while material substitution is useful in reducing vehicle weight, it often increases vehicle-cycle GHGs depending upon the material substitution pair. However, for a vehicle’s total life cycle, fuel economy benefits are greater than the increased burdens associated with the vehicle manufacturing cycle, resulting in a net total life-cycle GHG benefit. The vehicle cycle will become increasingly important in total vehicle life-cycle GHGs, since fuel-cycle GHGs will be gradually reduced as automakers ramp up vehicle efficiency to meet fuel economy standards.

  10. Influence of Particle Size of Deproteinized Bovine Bone Mineral on New Bone Formation and Implant Stability after Simultaneous Sinus Floor Elevation

    DEFF Research Database (Denmark)

    Jensen, Simon S; Aaboe, Merete; Janner, Simone F M;

    2013-01-01

    Deproteinized bovine bone mineral (DBBM) is one of the best-documented bone substitute materials for sinus floor elevation (SFE).......Deproteinized bovine bone mineral (DBBM) is one of the best-documented bone substitute materials for sinus floor elevation (SFE)....

  11. CO 2 sorption on substituted carbon materials . Computational chemistry studies

    Science.gov (United States)

    Gauden, P. A.; Wiśniewski, M.

    2007-04-01

    Theoretical study of sorption of CO 2 on the 4-ring graphene ("unmodified" or N-, O-, and OH-substituted) structures possessing one completely unsaturated edge zigzag site is reported using the DFT (B3LYP/6-31G(d,p)) method. Lactone and heterocyclic complexes (due to thermodynamic favourability) are taken into account. The analysis of theoretical results shows that the enthalpy of reaction strongly depends on the chemical nature, i.e. the position of the doping of atom(s) is crucial. All substitutions do not change or decrease the enthalpy in comparison with the "unmodified" graphene sheet. The well-known theoretical reactivity indices (ionization potential, electron affinity, global softness, and HOMO-LUMO gaps) are calculated for the studied adsorbents in order to explain the above-mentioned tendencies. Finally, the effect of the presence of heteroatoms on the enthalpy of reaction (Δ H298) for all CO 2-heteroatom-doping adsorbent complexes is shown. Thus, carbon dioxide molecules adsorb on the edge plane surface of N-, O-, OH-containing carbon surfaces similarly or much less favourably in comparison with the "unmodified" adsorbents. This confirms some experimental observations.

  12. Ability of bone graft substitutes to support the osteoprogenitor cells: An in-vitro study

    Institute of Scientific and Technical Information of China (English)

    Ziad; Dahabreh; Michalis; Panteli; Ippokratis; Pountos; Mark; Howard; Peter; Campbell; Peter; V; Giannoudis

    2014-01-01

    AIM: To compare seven commercially available bone graft substitutes(BGS) in terms of these properties and without using any additional biological growth factors.METHODS: Porcine osteoprogenitor cells were loaded on seven commercially available BGS and allowed to proliferate for one week followed by osteogenic induction. Staining for live/dead cells as well as scanning electron microscopy(SEM) was carried out to determine viability and cellular binding. Further outcome measures included alkaline phosphatase(ALP) assays with normalisation for DNA content to quantify osteogenic potential. Negative and positive control experiments were carried out in parallel to validate the results.RESULTS: Live/dead and SEM imaging showed higher viability and attachment with β-tricalcium phosphate(β-TCP) than with other BGS(P < 0.05). The average ALP activity in nmol/mL(normalised value for DNA content in nmol/μg DNA) per sample was 657.58(132.03) for β-TCP, 36.22(unable to normalise) for calcium sulphate, 19.93(11.39) for the Hydroxyapatite/Tricalcium Phosphate composite, 14.79(18.53) for polygraft, 13.98(8.15) for the highly porous β-Tricalcium Phosphate, 5.56(10.0) for polymers, and 3.82(3.8) for Hydroxyapatite.CONCLUSION: Under the above experimental conditions, β-TCP was able to maintain better the viability of osteoprogenitor cells and allow proliferation and differentiation(P < 0.05).

  13. Macroporous bioceramics: a remarkable material for bone regeneration.

    Science.gov (United States)

    Lew, Kien-Seng; Othman, Radzali; Ishikawa, Kunio; Yeoh, Fei-Yee

    2012-09-01

    This review summarises the major developments of macroporous bioceramics used mainly for repairing bone defects. Porous bioceramics have been receiving attention ever since their larger surface area was reported to be beneficial for the formation of more rigid bonds with host tissues. The study of porous bioceramics is important to overcome the less favourable bonds formed between dense bioceramics and host tissues, especially in healing bone defects. Macroporous bioceramics, which have been studied extensively, include hydroxyapatite, tricalcium phosphate, alumina, and zirconia. The pore size and interconnections both have significant effects on the growth rate of bone tissues. The optimum pore size of hydroxyapatite scaffolds for bone growth was found to be 300 µm. The existence of interconnections between pores is critical during the initial stage of tissue ingrowth on porous hydroxyapatite scaffolds. Furthermore, pore formation on β-tricalcium phosphate scaffolds also allowed the impregnation of growth factors and cells to improve bone tissues growth significantly. The formation of vascularised tissues was observed on macroporous alumina but did not take place in the case of dense alumina due to its bioinert nature. A macroporous alumina coating on scaffolds was able to improve the overall mechanical properties, and it enabled the impregnation of bioactive materials that could increase the bone growth rate. Despite the bioinertness of zirconia, porous zirconia was useful in designing scaffolds with superior mechanical properties after being coated with bioactive materials. The pores in zirconia were believed to improve the bone growth on the coated system. In summary, although the formation of pores in bioceramics may adversely affect mechanical properties, the advantages provided by the pores are crucial in repairing bone defects.

  14. Biological evaluation of alginate-based hydrogels, with antimicrobial features by Ce(III) incorporation, as vehicles for a bone substitute.

    Science.gov (United States)

    Morais, D S; Rodrigues, M A; Lopes, M A; Coelho, M J; Maurício, A C; Gomes, R; Amorim, I; Ferraz, M P; Santos, J D; Botelho, C M

    2013-09-01

    A novel hydrogel, based on an alginate/hyaluronate mixture and Ce(III) ions, with effective bioactive and antimicrobial ability was developed to be used as vehicle of a synthetic bone substitute producing an injectable substitute (IBS). Firstly, three different IBSs were prepared using three developed alginate-based hydrogels, the hydrogel Alg composed by alginate, the hydrogel Alg/Ch composed by an alginate/chitosan mixture and the hydrogel Alg/HA composed by an alginate/hyaluronate mixture. MG63 cells viability on the IBSs was evaluated, being observed a significantly higher cell viability on the Alg/HA_IBS at all time points, which indicates a better cell adaptation to the material, increasing their predisposition to produce extracellular matrix and thus allowing a better bone regeneration. Moreover, SEM analysis showed evident filopodia and a spreader shape of MG63 cells when seeded on Alg/HA_IBS. This way, based upon the in vitro results, the hydrogel Alg/HA was chosen to the in vivo study by subcutaneous implantation in an animal model, promoting a slight irritating tissue response and visible tissue repairing. The next step was to grant antimicrobial properties to the hydrogel that showed the best biological behavior by incorporation of Ce(III) ions into the Alg/HA, producing the hydrogel Alg/HA2. The antimicrobial activity of these hyaluronate-based hydrogels was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans. Results showed that Ce(III) ions can significantly enhance the hydrogel antimicrobial ability without compromising the osteoconductivity improvement promoted by the vehicle association to the synthetic bone substitute.

  15. Effect of a carbonated HAP/β-glucan composite bone substitute on healing of drilled bone voids in the proximal tibial metaphysis of rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Borkowski, Leszek, E-mail: leszek.borkowski@umlub.pl [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodźki 1, 20-093 Lublin (Poland); Pawłowska, Marta; Radzki, Radosław P.; Bieńko, Marek [Department of Animal Physiology, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin (Poland); Polkowska, Izabela [Department and Clinic of Animal Surgery, University of Life Sciences in Lublin, Głęboka 30, 20-612 Lublin (Poland); Belcarz, Anna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodźki 1, 20-093 Lublin (Poland); Karpiński, Mirosław [Department of Companion and Wildlife Animals, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin (Poland); Słowik, Tymoteusz [Independent Radiology Unit at Lublin Small Animals Medical Centre, Stefczyka 11, 20-151 Lublin (Poland); Matuszewski, Łukasz [Children' s Orthopaedic Clinic and Rehabilitation Department, Medical University of Lublin, Chodzki 2, 20-093 Lublin (Poland); Ślósarczyk, Anna [Faculty of Materials Science and Ceramics, AGH-University of Science and Technology, Mickiewicza 30, 30-059 Krakow (Poland); Ginalska, Grażyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodźki 1, 20-093 Lublin (Poland)

    2015-08-01

    A novel elastic hydroxyapatite-based composite of high surgical handiness has been developed. Its potential application in orthopedics as a filler of bone defects has been studied. The biomaterial was composed of carbonated hydroxyapatite (CHAP) granules and polysaccharide polymer (β-1,3-glucan). Cylinders of 4 mm in diameter and 6 mm in length were implanted into bone cavities created in the proximal metaphysis of tibiae of 24 New Zealand white rabbits. 18 sham-operated animals were used as controls. After 1, 3 or 6 months, the rabbits were euthanized, the bones were harvested and subjected to analysis. Radiological images and histological sections revealed integration of implants with bone tissue with no signs of graft rejection. Peripheral quantitative computed tomography (pQCT) indicated the stimulating effect of the biomaterial on bone formation and mineralization. Densitometry (DXA) analysis suggested that biomineralization of bones was preceded by bioresorption and gradual disappearance of porous ceramic granules. The findings suggest that the CHAP–glucan composite material enables regeneration of bone tissue and could serve as a bone defect filler. - Highlights: • Highly porous carbonate HAP granules and β-1,3-glucan were used to fill bone voids. • Critical size defects of rabbit tibiae were filled with the composite scaffolds. • Biocompatibility, mineralization and osseointegration of implants were examined. • Histological analysis indicated a high biocompatibility of composite grafts. • We report penetration of bony tissue into implants and advanced osseointegration.

  16. The role of angiogenesis in implant dentistry part II: The effect of bone-grafting and barrier membrane materials on angiogenesis

    Science.gov (United States)

    Asatourian, Armen; Garcia-Godoy, Franklin; Sheibani, Nader

    2016-01-01

    Background In implant dentistry, bone substitute materials and barrier membranes are used in different treatments including guided bone regeneration (GBR), socket preservation, alveolar ridge augmentation, maxillary sinus elevation, and filling bony defects around the inserted dental implant. One of the most important factors in prognosis of treatments using these materials is the growth of new blood vessels in applied areas. Present review was performed to evaluate the effect of the bone-grafting and barrier membrane materials on angiogenesis events. Material and Methods An electronic search was performed in PubMed, MEDLINE, and EMBASE databases via OVID using the keywords mentioned in the PubMed and MeSH headings regarding the role of angiogenesis in implant dentistry from January 2000-April 2014. Results Of the 5,622 articles identified in our initial search results, only 33 met the inclusion criteria set for this review. Among bone substitute materials the autogenous bone-grafts, and among the barrier membranes the collagenous membranes, had the highest angiogenic potentials. Other bone-grafting materials or membranes were mostly used with pro-angiogenic factors to enhance their angiogenic properties. Conclusions Angiogenesis is one of the key factors, which plays a critical role in success rate of GBR technique and is seriously considered in manufacturing bone-grafting and barrier membrane materials. However, there is still lack of clinical and in-vivo studies addressing the effect of angiogenesis in treatments using bone-grafting and barrier membrane materials. Key words:Angiogenesis, bone-grafting materials, GBR, ridge augmentation, sinus elevation, socket preservation. PMID:27031074

  17. Behavior of POP-calcium carbonate hydrogel as bone substitute with controlled release capability: a study in rat.

    Science.gov (United States)

    Dewi, Anne Handrini; Ana, Ika Dewi; Wolke, Joop; Jansen, John

    2015-10-01

    Gypsum or calcium sulfate (CS) or plaster of Paris (POP) is considered as a fast degradable material that usually resorbs before the bone defect area is completely filled by new bone. In this study, the incorporation of CaCO3 hydrogel into POP in different compositions was proposed to enhance the bone biological activity of POP and to decrease its degradability. The mechanical and degradation properties of the various materials were characterized by in vitro analysis. Subsequently, the materials were inserted into cylindrically sized bone defects as created into the femoral condyle of rats and left in situ for 1, 4, and 8 weeks. Histological analysis of the retrieved specimens indicated that the addition of CaCO3 hydrogel into POP increased bone formation, angiogenesis and collagen density and resulted into faster bone formation and maturation. It was also confirmed that the degradation rate of the POP decreased by the addition of CaCO3 hydrogel. The in vivo findings did corroborate with the in vitro analysis. In conclusion, the incorporation of CaCO3 hydrogel provides a promising technology to improve the properties of POP, the oldest biomaterial used for bone grafting.

  18. Comparative experiment of four different materials as carriers of Bone morphogenetic protein to repair long bone defect

    Institute of Scientific and Technical Information of China (English)

    WEI Kuan-hai; PEI Guo-xian; YANG Run-gong

    2001-01-01

    @@ OBJECTIVE To investigate the effects of four different materials as carriers of bone morphogenetic protein (BMP) to repair long bone defect. METHODS 12 mm radius bone defects were made. They were divided into 4 groups in random and repaired respectively with the vascular muscle flap combined with FS/BMP (group A), vascular muscle flap/BMP (group B), bloodless muscle flap/BMP (group C) and autolyzed antigen-extracted allogeneic bone (AAA)/BMP (group D).Their abilities of bone forming to repair bone defects were observed.

  19. Biomechanical Stability of Juvidur and Bone Models on Osteosyntesic Materials

    Science.gov (United States)

    Grubor, Predrag; Mitković, Milorad; Grubor, Milan; Mitković, Milan; Meccariello, Luigi; Falzarano, Gabriele

    2016-01-01

    Introduction: Artificial models can be useful at approximate and qualitative research, which should give the preliminary results. Artificial models are usually made of photo-elastic plastic e.g.. juvidur, araldite in the three-dimensional contour shape of the bone. Anatomical preparations consist of the same heterogeneous, structural materials with extremely anisotropic and unequal highly elastic characteristics, which are embedded in a complex organic structure. The aim of the study: Examine the budget voltage and deformation of: dynamic compression plate (DCP), locking compression plate (LCP), Mitkovic internal fixator (MIF), Locked intramedullary nailing (LIN) on the compressive and bending forces on juvidur and veal bone models and compared the results of these two methods (juvidur, veal bone). Material and Methods: For the experimental study were used geometrically identical, anatomically shaped models of Juvidur and veal bones diameter of 30 mm and a length of 100 mm. Static tests were performed with SHIMADZU AGS-X testing machine, where the force of pressure (compression) increased from 0 N to 500 N, and then conducted relief. Bending forces grew from 0 N to 250 N, after which came into sharp relief. Results: On models of juvidur and veal bones studies have confirmed that uniform stability at the site of the fracture MIF with a coefficient ranking KMIF=0,1971, KLIN=0,2704, KDCP=0,2727 i KLCP=0,5821. Conclusion: On models of juvidur and veal bones working with Shimadzu AGS-X testing machine is best demonstrated MIF with a coefficient of 0.1971. PMID:27708489

  20. Studies on preparation and property of high-substitutional starch acetate hydrophode for the membrane material

    Institute of Scientific and Technical Information of China (English)

    ZUO Xiu-jin; DAI Xiao-min; MA Xiao-jun

    2005-01-01

    @@ Control-release technique is probably the most widely used,films control-release technique is the key of control-release technique,and film materials are the elements.The high-substitutional starch acetate was prepared by acetylation of starch with an acetic anhydride mixture.The best parameter of the technics (time of activation and reaction, reactant ratio) was obtained by orthogonal experiments.It was the hydrophode membrane material that property of the high-substitutional starch acetate was proofed.

  1. Towards new green high energy materials. Computational chemistry on nitro-substituted urea.

    Science.gov (United States)

    Wagner, Rachelle R; Ball, David W

    2011-11-01

    As part of a series of studies on new potential green high energy materials, we have calculated the structures and properties of a series of nitro-substituted urea molecules. Our results indicate that nitrated urea molecules have specific enthalpies of decomposition commensurate with current high energy materials. At the same time, they are all low in carbon, suggesting an application as a "green" high energy material.

  2. Modern materials in fabrication of scaffolds for bone defect replacement

    Science.gov (United States)

    Bazlov, V. A.; Mamuladze, T. Z.; Pavlov, V. V.; Kirilova, I. A.; Sadovoy, M. A.

    2016-08-01

    The article defines the requirements for modern scaffold-forming materials and describes the main advantages and disadvantages of various synthetic materials. Osseointegration of synthetic scaffolds approved for use in medical practice is evaluated. Nylon 618 (certification ISO9001 1093-1-2009) is described as the most promising synthetic material used in medical practice. The authors briefly highlight the issues of individual bone grafting with the use of 3D printing technology. An example of contouring pelvis defect after removal of a giant tumor with the use of 3D models is provided.

  3. Bone Indices in Thyroidectomized Patients on Long-Term Substitution Therapy with Levothyroxine Assessed by DXA and HR-pQCT

    Directory of Open Access Journals (Sweden)

    Emil Moser

    2015-01-01

    Full Text Available Background. Studies on bone effects of long-term substitution therapy with levothyroxine (LT4 have shown discrepant results. Previous studies have, however, not evaluated volumetric bone mineral densities (vBMD, bone structure, and strength using high resolution peripheral quantitative computed tomography (HR-pQCT and finite element analysis (FEA. Using a cross-sectional design, we aimed to determine whether BMD, structure, and strength are affected in hypothyroid patients on LT4 substitution therapy. Methods. We compared 49 patients with well-substituted hypothyroidism with 49 age- and gender-matched population based controls. Areal BMD was assessed by DXA, vBMD and bone geometry by HR-pQCT, and bone strength by FEA. Results. Patients had been thyroidectomized due to thyroid cancer (10% and nontoxic (33% or toxic goiter (57%. 82% were women. TSH levels did not differ between groups, but patients had significantly higher levels of T4 (p<0.001 and lower levels of T3 (p<0.01. Compared to controls, patients had higher levels of magnesium (p<0.05, whereas ionized calcium and PTH were lower (p<0.05. Bone scans did not reveal any differences in BMD, bone geometry, or strength. Conclusion. If patients with hypothyroidism are well-substituted with LT4, the disease does not affect bone indices to any major degree.

  4. Antibacterial and biocompatible properties of vancomycin-loaded nano-hydroxyapatite/collagen/poly (lactic acid) bone substitute

    Institute of Scientific and Technical Information of China (English)

    Xiaojie Lian; Huanye Liu; Xiumei Wang; Suju Xu; Fuzhai Cui; Xizhuang Bai

    2013-01-01

    Infected bone defects are normally regarded as contraindications for bone grafting. In the present study, an antibacterial bone graft substitute was synthesized by loading vancomycin (VCM) in our previously developed mineralized collagen based composite, nano-hydroxyapatite/collagen/poly (lactic acid) (nHAC/PLA), aiming to repair large size bone defects and inhibit related infections simultaneously. The VCM/nHAC/PLA showed typical porous structure with a porosity of (80.776.7)%and compressive strength of 1.52 MPa. The delivery of VCM from VCM/nHAC/PLA was detected in vitro for up to 4 weeks. And their antibacterial properties were determined using inhibition ratio assay and inhibition zone assay. Pretty high level of inhibition ratio (more than 99%) was obtained in VCM/nHAC/PLA group. Additionally, a distinct inhibition zone was clearly formed in Staphylococcus aureus bacterium incubation dish with VCM/nHAC/PLA disc for up to 18 days of incubation. Moreover, both of the nHAC/PLA composites with or without VCM exhibited favorable in vitro and in vivo biocompatibilities for rabbit marrow stromal cells (MSCs) adhesion, spreading, proliferation, and triggering no obvious inflammation responses in subcutaneous implantation. Our results suggested that the VCM/nHAC/PLA performed ideal antibacterial property and biocompatibility and has great promise for the treatment of bone defect-related infections in orthopedic surgeries.

  5. Material Mismatch Effect on the Fracture of a Bone-Composite Cement Interface.

    Science.gov (United States)

    Khandaker, M; Tarantini, S

    2012-12-01

    The interfacial mechanics at the bone-implant interface is a critical issue for implant fixation and the filling of bone defects created by tumors and/or their excision. Our previous study found that micron and nano sizes MgO particles improved the fracture toughness of bone-cement interfaces under tension loading. The strength of bonding of different types of bone with different types of implants may not be the same. The aims of this research were to determine the influences of material mismatch due to bone orientation and a magnesium oxide (MgO) filler material for PMMA bone cement on the mechanical strength between bone and bone cement specimens. This research studied the longitudinal and transverse directions bovine cortical bone as different bone materials and poly Methyl MethAcrylate (PMMA) bone cement with and without MgO additives as different implant materials. The scope of work for this study was: (1) to determine the bending strength and modulus of different bone and bone cement specimens, (2) to determine whether inclusion of MgO particles on PMMA has any influence on these mechanical properties of PMMA, and (3) to determine whether bone orientation and inclusion of MgO particles with PMMA has any influence on the interface strength between bone and PMMA. This study showed that bone orientation has statistically significant effect on the bonding strength between bone and bone cement specimens (P value0.05).

  6. Bone remodeling induced by dental implants of functionally graded materials.

    Science.gov (United States)

    Lin, Daniel; Li, Qing; Li, Wei; Swain, Michael

    2010-02-01

    Functionally graded material (FGM) had been developed as a potential implant material to replace titanium for its improved capability of initial osseointegration. The idea behind FGM dental implant is that its properties can be tailored in accordance with the biomechanical needs at different regions adapting to its hosting bony tissues, therefore creating an improved overall integration and stability in the entire restoration. However, there have been very few reports available so far on predicting bone remodeling induced by FGM dental implants. This article aims to evaluate bone remodeling when replacing the titanium with a hydroxyapatite/collagen (HAP/Col) FGM model. A finite element model was constructed in the buccal-lingual section of a dental implant-bone structure generated from in vivo CT scan images. The remodeling simulation was performed over a 4 year healing period. Comparisons were made between the titanium implant and various FGM implants of this model. The FGM implants showed an improved bone remodeling outcome. The study is expected to provide a basis for future development of FGM implants.

  7. Tooth and bone deformation: structure and material properties by ESPI

    Science.gov (United States)

    Zaslansky, Paul; Shahar, Ron; Barak, Meir M.; Friesem, Asher A.; Weiner, Steve

    2006-08-01

    In order to understand complex-hierarchical biomaterials such as bones and teeth, it is necessary to relate their structure and mechanical-properties. We have adapted electronic speckle pattern-correlation interferometry (ESPI) to make measurements of deformation of small water-immersed specimens of teeth and bones. By combining full-field ESPI with precision mechanical loading we mapped sub-micron displacements and determined material-properties of the samples. By gradually and elastically compressing the samples, we compensate for poor S/N-ratios and displacement differences of about 100nm were reliably determined along samples just 2~3mm long. We produced stress-strain curves well within the elastic performance range of these materials under biologically relevant conditions. For human tooth-dentin, Young's modulus in inter-dental areas of the root is 40% higher than on the outer sides. For cubic equine bone samples the compression modulus of axial orientations is about double the modulus of radial and tangential orientations (20 GPa versus 10 GPa respectively). Furthermore, we measured and reproduced a surprisingly low Poisson's ratio, which averaged about 0.1. Thus the non-contact and non-destructive measurements by ESPI produce high sensitivity analyses of mechanical properties of mineralized tissues. This paves the way for mapping deformation-differences of various regions of bones, teeth and other biomaterials.

  8. EVALUATION OF POSTERIOR SPINAL FUSION WITH PEDICLE SCREWS AND RODS WITH BONE SUBSTITUTES IN GRADE I AND II SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    Chaitanya Reddy

    2016-04-01

    Full Text Available BACKGROUND Low-back pain is the commonest condition encountered day in and day out of an orthopaedic practice. Incidence of spondylolisthesis in normal population is around 5-7%. No matter what the aetiology is, patient has significant functional disability. OBJECTIVES To study the efficacy of pedicular screw rod system and posterolateral fusion with bone substitutes in spondylolisthesis, and to study the complications associated with this treatment modality. METHODOLOGY From July 2012 to September 2014, a total of 30 patients operated with posterolateral fusion were followed up and evaluated based on VAS for low back pain and Japanese orthopaedic association scoring system. RESULTS The mean difference between pre-operative and post-operative VAS score is 3SD with a p value of <0.001, which is strongly significant. The pre-operative and post-operative JOA score has an improvement of 73.4% with a p value of <0.001, which is strongly significant. Rate of improvement was excellent in 16.7%, good in 53.3%, fair in 23.3% and poor in 6.3% of patients; 82% of patients had bone fusion by the end of 8 months. CONCLUSION Pedicular screw rod system with postero-lumbar fusion with bone substitute is safe, promising and appealing technique for low-grade spondylolisthesis with early post-operative pain relief.

  9. A new surgical management for oro-antral communication: the resorbable guided tissue regeneration membrane--bone substitute sandwich technique.

    Science.gov (United States)

    Ogunsalu, C

    2005-09-01

    This paper describes a new technique for the closure of oro-antral fistula/communication, in which both hard tissue (bone) and soft tissue closure is achieved. The sandwich technique utilizes a suitable bone grafting material sandwiched between two sheaths of Biogide (a resorbable membrane) for the hard tissue closure of oro-antral communication post traumatic exodontia. The bone grafting material utilized for this case was Bio-oss. The result obtained was excellent with regeneration of sufficient bony tissue to allow placement of an endosseous implant. This sandwich technique is a simple and excellent technique for the closure of oro-antral communication, especially when subsequent placement of endosseous implant is considered without the need of donor site surgery for bone grafting. The otorhinolaryngologists and oral and maxillofacial surgeons should find this technique very useful in the closure of oro-antral fistulae.

  10. [Regeneration processes in bone defects after implantation of composite material of different density of polylactide origin filled with HAP (experimental-morphological study)].

    Science.gov (United States)

    Kulakov, A A; Grigor'ian, A S; Krotova, L I; Popov, V K; Volozhin, A I; Losev, V F

    2009-01-01

    In experimental-morphological study on 6 dogs the dynamics of regenerate formation in ulna and mandible defects after implantation in them composite material of different density (0.46-0.50 and 0.38-0.42 g/cm(3)) of polylactide (PL) origin filled with HAP was followed at the terms of 6 and 9 months. Histologic study and structural determinant distribution analysis in the content of regenerate showed that optimal results according to the bone defect substitution by bone regenerate criterion at 9th month of the experiment were received after composite material from PL and HAP with the density of 0.38-0.42 g/cm(3) implantation. Newly formed trabecular bone tissue was seen in the regenerate and as well as strong tendency for bone matrix maturation. It was confirmed by the appearance of lamellar structures in newly formed bone trabecules situated in peripheral zones of bone defect. In bone mandible defects the substitution process of the implants from PL with HAP by the bone tissue was much slower than in ulna defects.

  11. CT assisted biomimetic artificial bone des

    Institute of Scientific and Technical Information of China (English)

    WANG Xian-gang; ZHANG Chao-zong; GUO Zhi-ping; TIAN Jie-mo

    2001-01-01

    @@ In the recent years, bioceramic materials have been widely used in the clinics. They are mainly fabricated as the substitution of human hard tissue, such as artificial bone and false tooth. As a medical implant, those that have similar structure to human bone have better biocompatibility and osteoinductional property. So it is necessary to design bone model close to human bone.

  12. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects

    DEFF Research Database (Denmark)

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S;

    2015-01-01

    The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled with nanocr......The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled...... with nanocrystalline hydroxyapatite (HA-SiO), deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (BCP 60/40) ratio, or particulate autogenous bone (A) for histological and histomorphometric analysis. At 2 weeks, percent filler amongst the test groups (DBBM (35.65%), HA...

  13. Wood would - Mass timber as a sustainable substitute for traditional building materials

    NARCIS (Netherlands)

    Struiksma, A.F.; Smilde, J.A.; Van Houten, R.S.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Innovation and Sustainability This manual explains why mass timber is the sustainable substitute for conventional materials and how it can be implemented in the design. It is intended for architects who usually always build in steel and

  14. Posterolateral arthrodesis in lumbar spine surgery using autologous platelet-rich plasma and cancellous bone substitute: an osteoinductive and osteoconductive effect.

    Science.gov (United States)

    Tarantino, Roberto; Donnarumma, Pasquale; Mancarella, Cristina; Rullo, Marika; Ferrazza, Giancarlo; Barrella, Gianna; Martini, Sergio; Delfini, Roberto

    2014-08-01

    Study Design Prospective cohort study. Objectives To analyze the effectiveness and practicality of using cancellous bone substitute with platelet-rich plasma (PRP) in posterolateral arthrodesis. Methods Twenty consecutive patients underwent posterolateral arthrodesis with implantation of cancellous bone substitute soaked with PRP obtained directly in the operating theater on the right hemifield and cancellous bone substitute soaked with saline solution on the right. Results Computed tomography scans at 6 and 12 months after surgery were performed in all patients. Bone density was investigated by comparative analysis of region of interest. The data were analyzed with repeated-measures variance analyses with value of density after 6 months and value of density after 12 months, using age, levels of arthrodesis, and platelet count as covariates. The data demonstrated increased bone density using PRP and heterologous cancellous block resulting in an enhanced fusion rate during the first 6 months after surgery. Conclusions PRP used with cancellous bone substitute increases the rate of fusion and bone density joining osteoinductive and osteoconductive effect.

  15. Avaliação pré-clínica de um material substituto ósseo xenógeno a base de hidroxiapatita/colágeno = Preclinical evaluation of a xenogenic hydroxyapatite/collagen-based bone substitute material

    Directory of Open Access Journals (Sweden)

    Bittencourt, Rafael Cotias

    2014-01-01

    Full Text Available Objetivo: O objetivo deste estudo foi avaliar as propriedades físicas, químicas e biológicas de um xenoenxerto bovino para o reparo ósseo. Métodos: Análise físico-química foi conduzida usando difração de raios X, espectroscopia no infravermelho por transformada de Fourier e microscopia eletrônica de varredura. Biocompatibilidade in vitro foi avaliada através de ensaios de citotoxicidade e adesão celular usando culturas de linhagem celular de fibroblastos e pré-osteoblastos murinos, respectivamente. Além disso, por ensaio in vivo usando enxertia subcutânea no modelo rato (5 e 10 semanas, hidroxiapatita sintética como material controle e ainda um experimento a longo prazo em defeitos de tamanho crítico em calvária (6 e 9 meses, coágulo sanguíneo e osso autógeno como controles negativo e positivo, respectivamente. Resultados: O material teste apresentou uma arquitetura tridimensional consistindo de grânulos densos e microporos (várias dimensões, composto de hidroxiapatita cristalina/fibras colágenas. O xenoenxerto foi citocompatível e após 7 dias foi observado espraiamento de pré-osteoblastos sobre grânulos do material. Análise histopatológica do material implantado no subcutâneo de ratos mostrou o xenoenxerto intato após 10 semanas circundado por tecido conjuntivo frouxo com suave infiltrado inflamatório e células gigantes multinucleadas ao redor de partículas (5 e 10 semanas similar à hidroxiapatita sintética. Considerando os defeitos de tamanho crítico em calvária foi observada 1,7 vezes mais formação de novo osso no xenoenxerto do que no grupo controle (P<0,001, um resultado similar verificado no autoenxerto. Não houve variação significante na densidade de volume do xenoenxerto (37,9%±4,3. Conclusão: Pode-se concluir que o material xenógeno é biomimético, biocompatível, osseocondutor e nãoreabsorvível, portanto sendo um material promissor para o reparo óss

  16. Novel Approaches to Bone Grafting: Porosity, Bone Morphogenetic Proteins, Stem Cells, and the Periosteum

    OpenAIRE

    Petrochenko, Peter; Narayan, Roger J.

    2010-01-01

    The disadvantages involving the use of a patient’s own bone as graft material have led surgeons to search for alternative materials. In this review, several characteristics of a successful bone graft material are discussed. In addition, novel synthetic materials and natural bone graft materials are being considered. Various factors can determine the success of a bone graft substitute. For example, design considerations such as porosity, pore shape, and interconnection play significant roles i...

  17. Synchrotron μCT Imaging of Bone, Titanium implants and Bone Substitutes -a Systematic Review of the Literature

    DEFF Research Database (Denmark)

    Neldam, Camilla Albeck; Pinholt, Else Marie

    2014-01-01

    examinations, SRμCT is considered as a gold standard to image trabecular bone microarchitecture since it is possible in a 3D manner to visualize fine structural elements within mineralized tissue such as osteon boundaries, rods and plates structures, cement lines, and differences in mineralization...

  18. The Effect of Bauxite Substitution on High Temperature Strength Properties of Zirconia—corundum Mullite Material

    Institute of Scientific and Technical Information of China (English)

    ZHONGWei-bin; SUNGeng-chen; 等

    1994-01-01

    Investigations on the effect of bauxite substi-tution for industrial alumina on high temperature strength and thermal shock resistance of reaction-sintered zirconia-corundum-mullite material(ZrO2 15%) have indicated that bauxite substitution would lead to increase in modulus of rupture at 1000-1400℃ as well as improvement in thermal shock resistance,Hot strength value reaches a maximum at 15% buxite addition.The mecha-nism of mechanical behavior at elevated tempera-tures is discussed in association with changes in mi-crostructural characteristics.

  19. Evaluation of cell binding peptide (p15) with silk fibre enhanced hydroxyappatite bone substitute for posterolateral spinal fusion in sheep

    DEFF Research Database (Denmark)

    Axelsen, M.; Jespersen, Stig; Overgaard, Søren;

    2015-01-01

    were assessed with 2D sections and 3D reconstruction images and fusion was defined as intertransverse bridging. Results: Spinal fusion was found in 72 % of levels receiving silk fibre enhanced ABM/P15 graft material. In levels with silk fibre enhanced AMB fusion rate was 41 %. These findings...... on the surface of bone forming cells. The binding initiates natural intra- and extracellular signalling pathways, inducing production of growth factors, bone morphogenic proteins and cytokines. P15 peptide has previously shown to improve osteoinductive properties when coated on graft materials. Purpose...

  20. Evolutionary design of bone scaffolds with reference to material selection.

    Science.gov (United States)

    Heljak, M K; Swięszkowski, W; Lam, C X F; Hutmacher, D W; Kurzydłowski, K J

    2012-01-01

    The favourable scaffold for bone tissue engineering should have desired characteristic features, such as adequate mechanical strength and three-dimensional open porosity, which guarantee a suitable environment for tissue regeneration. In fact, the design of such complex structures like bone scaffolds is a challenge for investigators. One of the aims is to achieve the best possible mechanical strength-degradation rate ratio. In this paper we attempt to use numerical modelling to evaluate material properties for designing bone tissue engineering scaffold fabricated via the fused deposition modelling technique. For our studies the standard genetic algorithm was used, which is an efficient method of discrete optimization. For the fused deposition modelling scaffold, each individual strut is scrutinized for its role in the architecture and structural support it provides for the scaffold, and its contribution to the overall scaffold was studied. The goal of the study was to create a numerical tool that could help to acquire the desired behaviour of tissue engineered scaffolds and our results showed that this could be achieved efficiently by using different materials for individual struts. To represent a great number of ways in which scaffold mechanical function loss could proceed, the exemplary set of different desirable scaffold stiffness loss function was chosen.

  1. Complex reconstruction of the dorsal hand using the induced membrane technique associated with bone substitute: A case report

    Science.gov (United States)

    Guillier, David; Rizzi, Philippe; De Taddeo, Alice; Henault, Benoit; Tchurukdichian, Alain; Zwetyenga, Narcisse

    2016-01-01

    Introduction High-energy trauma of the hand often causes tissue loss involving bone, tendon and skin and is sometimes accompanied by devascularization of digits. Bone stabilization is the first step in the management of such injuries. Materials and methods A young patient presented composite tissue loss of the dorsum of his right (dominant) hand following an accident with a surface planer. Tissue loss involved the diaphyses of the first 4 metacarpals, tendons and skin with almost complete amputation of the 3rd finger. Bone stabilization comprised osteosynthesis using pins associated with cement to fill the bone defect. Hunter tendon rods were used for tendon repair and a pedicle groin flap (McGregor) was used to achieve skin coverage. The cement was replaced with autologous cortico-cancellous bone graft combined with bone paste (Nanostim) 3 months after the cement stabilization. Results Eleven months after the accident, the patient was able to return to work as a carpenter. Pinch and Grasp strength in the injured hand were half that in the contralateral hand, but there was no loss of sensitivity. Mobility was very satisfactory with a Kapandji score of 9 and a mean TAM of 280°. The patient can write, open a bottle and does not feel limited for everyday activities. Radiographically, the bone of the 3 reconstructed metacarpals appears consolidated. Conclusion The induced membrane technique allowed the reconstruction of small bone deficits in the long bones of the hand in a two-step procedure, the first step taking place in an emergency context of composite tissue trauma. PMID:27077131

  2. Use of osteoplastic material to guide bone tissue regeneration deffect.

    Science.gov (United States)

    Machavariani, A; Mazmishvili, K; Grdzelidze, T; Menabde, G; Amiranashvili, I

    2011-12-01

    The goal of research was study of restoration processes in jaw-teeth bone defects by application of osteoplastic materials in the experiment. The experiment was performed over 32 white (6-12 month old) rats; the animals were divided into 2 groups; 16 animals were enrolled in the first group; the section was performed in the edge of lower jaw; the lower jaw body was revealed. Under the effect of the dental drilling machine and the # 1 cooling mean by the fissure bohrium (distilled water) the defect of the dimension of 2x2 mm was created; the defect was washed by 0/9% saline to remove the bone sawdust; the wound was sutured tightly, in layers. The second group of the experiment was staffed with 16 animals (main group); the similar bone defect of the size 2 x 2mm was created on the rat's jaw's body. After washing of modeled defect we inserted osteopathic materials PORESORB-TCP crystals with the size of 0,6-1.0 mm the wound was sutured tightly, in layers. After the 3-rd, 15-th, 30-th and 90-th days from the date of operation there was performed X-ray and morphological examination over the animals in the control as well as the main group. The analysis of the examination performed over the experimental materials showed that in the control group in samples taken at 90th day the defects were not completely restored. In the test group in samples taken at 90th day reparative regeneration is confirmed. This is stimulated by the factor that within the main group's animals the defect regeneration process is supported with the osteoplastic material PORESORB-TCP.

  3. Histological and morphometric aspects of ridge preservation with a moldable, in situ hardening bone graft substitute

    Directory of Open Access Journals (Sweden)

    Jurišić M.

    2013-01-01

    Full Text Available Biphasic calcium phosphates (BCP are widely used in alveolar ridge regeneration as a porous scaffold for new bone formation. The aim of this case series was to evaluate the regenerative effect of the combination of BCP and polylactide-co-glycolide (PLGA which can serve as a barrier membrane during bone regeneration. The study included five patients. Four months into the healing period, bone samples were collected for histological and morphometric analyses. The results of morphometric analysis showed that newly formed bone represented 32.2 ± 6.8% of the tissue, 31.9 ± 8.9% was occupied by residual graft and 35.9 ± 13.5% by soft tissue. Active osteogenesis was seen around the particles of the graft. The particles were occupied mostly by immature woven bone and connective tissue. The quality and quantity of newly formed bone, after the use of BCP/PLGA for ridge preservation, can be adequate for successful implant therapy after tooth extraction. [Projekat Ministarstva nauke Republike Srbije, br. OI 175021 i br. OI 173009

  4. Beneficial use of meat and bone meal combustion residue: "an efficient low cost material to remove lead from aqueous effluent".

    Science.gov (United States)

    Deydier, Eric; Guilet, Richard; Sharrock, Patrick

    2003-07-04

    Meat and bone meal (MBM) combustion residues, a natural apatite-rich substance, was evaluated as a low cost substitute for hydroxyapatite in lead sequestration from water effluents. The thermal behaviour of crude meat and bone meal was followed by TGA and 24% inorganic residue was collected. The resulting ashes were characterised by powder X-ray diffraction (XRD), particle size distribution, specific surface area (BET), and elemental analysis confirming apatite contents, with high level of phosphate (56.3%) and calcium (36.8%). Mechanism and kinetics of lead removal by this bioinorganic material were investigated and compared to mechanisms and kinetics involved with synthetic apatite. Batch metal removal experiments were carried out with 500 and 1500ppm (mg/kg) Pb(2+) solutions. Lead concentration, calcium and pH were monitored. We observed that the mechanism is similar to that occurring for pure apatite, and involved both surface complexation and calcium hydroyapatite (CaHA), Ca(10)(PO(4))(6)(OH)(2), dissolution followed by less soluble Pb(10)(PO(4))(6)(OH)(2) precipitation, as confirmed by XRD analysis of ashes after incubation with lead solution. Our results show that this natural apatite-rich material removes in a few minutes a large quantity of lead (275mg/g capacity) which remains however lower than the theoretical maximum capacity (if calcium were totally substituted by lead). Meat and bone meal combustion residues represent a valuable alternative apatite source for environmental application.

  5. Axial vascularization of a large volume calcium phosphate ceramic bone substitute in the sheep AV loop model.

    Science.gov (United States)

    Beier, Justus P; Horch, Raymund E; Hess, Andreas; Arkudas, Andreas; Heinrich, Johanna; Loew, Johanna; Gulle, Heinz; Polykandriotis, Elias; Bleiziffer, Oliver; Kneser, Ulrich

    2010-03-01

    Vascularization still remains an obstacle to engineering of bone tissue with clinically relevant dimensions. Our aim was to induce axial vascularization in a large volume of a clinically approved biphasic calcium phosphate ceramic by transferring the arteriovenous (AV) loop approach to a large animal model. HA/beta-TCP granula were mixed with fibrin gel for a total volume of 16 cm(3), followed by incorporation into an isolation chamber together with an AV loop. The chambers were implanted into the groins of merino sheep and the development of vascularization was monitored by sequential non-invasive magnetic resonance imaging (MRI). The chambers were explanted after 6 and 12 weeks, the pedicle was perfused with contrast agent and specimens were subjected to micro-computed tomography (micro-CT) scan and histological analysis. Sequential MRI demonstrated a significantly increased perfusion in the HA/beta-TCP matrices over time. Micro-CT scans and histology confirmed successful axial vascularization of HA/beta-TCP constructs. This study demonstrates, for the first time, successful axial vascularization of a clinically approved bone substitute with a significant volume in a large animal model by means of a microsurgically created AV loop, thus paving the way for the first microsurgical transplantation of a tissue-engineered, axially vascularized bone with clinically relevant dimensions.

  6. Effects of composition of biocomposite materials implanted into hole defects of the metaphysis on the reparative regeneration and mineralization of bone tissue.

    Science.gov (United States)

    Luneva, S N; Talashova, I A; Osipova, E V; Nakoskin, A N; Emanov, A A

    2013-12-01

    We carried out a comparative analysis of morphological pattern and element composition of regenerated bone tissue forming in the metaphysis defects after substitution of these defects with calcium phosphate substance containing low-molecular non-collagen bone proteins with various affinities to ion exchangers. We have found that regenerated tissue in the defects grew from the edges to the center and its element composition depended on the maturity of newly formed bone tissue. Implantation material containing non-collagen bone proteins with various affinities to ion exchangers induced no significant changes in the content of analyzed elements of bone tissue around the defect. The content of analyzed elements in the areas distant from the defect area did not change during the experiment.

  7. Biological evaluation of alginate-based hydrogels, with antimicrobial features by Ce(III) incorporation, as vehicles for a bone substitute

    OpenAIRE

    MORAIS, D.S.; Rodrigues, M. A.; Lopes, M A; Coelho, M.J.; Maurício, Ana Colette; Gomes, R; Amorim, Irina; Ferraz, M. P.; Santos,J.D.; Botelho, C. M.

    2013-01-01

    In this work three different hydrogels were developed to associate, as vehicles, with the synthetic bone substitute GR-HA. One based on an alginate matrix (Alg); a second on a mixture of alginate and chitosan (Alg/Ch); and a third on alginate and hyaluronate (Alg/HA), using Ca2+ ions as cross-linking agents. The hydrogels, as well as the respective injectable bone substitutes (IBSs), were fully characterized from the physical-chemical point of view. Weight change studies proved that all hydro...

  8. RESULTS OF THE FOSFOMYCIN APPLICATION FOR THE IMPREGNATION OF BONE REPLACEMENT MATERIALS IN THE TREATMENT OF CHRONIC OSTEOMYELITIS

    Directory of Open Access Journals (Sweden)

    V. A. Konev

    2016-01-01

    Full Text Available Aim – to evaluate in the experimental study in vitro the duration of antimicrobial activity of fosfomycin-impregnated bone cement and to study the dynamics of radiological and morphological changes depending on the local antibiotic therapy in two-stage treatment of chronic osteomyelitis in rabbits.Materials and methods. Duration of antimicrobial activity of bone cement (depuy cmw1 gentamicin with fosfomycin in vitro was studied in comparison to cements with vancomycin and controls without additional antibiotics. Presence of the lysis zone of bacterial cultures was evaluated (Staphylococcus aureus ATCC6538 and ATCC33591, Klebsiella pneumoniae ATCC33495 and Escherichia coli ATCC25922 after application of 10 μl of the solution, collected from the cement samples after incubation for 24 hours. For the in vivo experiment, Chinchilla rabbits (n = 20 with local osteomyelitis of the tibia underwent two-stage treatment where substitution of the bone defect at stage I was performed with PMMA and stage II – with the bioresorbable material based on hydroxyapatite and triclacium phosphate (ReproBone. In an experience group (n = 10 before setting osteoreplacement materials with fosfomycin (group FOSFO, and by control (n = 10 – vancomycin (group VANCO. X-ray imaging was performed on the 1st and 21st day after installation of the cement spacer, and 45th day after substitution of the spacer with the bioresorbable material. Microbiological analysis of the samples was performed intraoperatively and on the 7th, 14th day after each stage. Histological study was conducted in both groups on the 14th, 21th day after stage I and 45th day after stage II of the treatment.Results. Maximal duration of antimicrobial activity in vitro was observed in samples of PMMA with fosfomycin whereas minimal – in control samples of gentamicin-based bone cement. Relief of the infection was attained in all animals while application of fosfomycin resulted in a more

  9. Effects of altered crystalline structure and increased initial compressive strength of calcium sulfate bone graft substitute pellets on new bone formation.

    Science.gov (United States)

    Urban, Robert M; Turner, Thomas M; Hall, Deborah J; Infanger, Susan I; Cheema, Naveed; Lim, Tae-Hong; Moseley, Jon; Carroll, Michael; Roark, Michael

    2004-01-01

    A new, modified calcium sulfate has been developed with a different crystalline structure and a compressive strength similar to many calcium phosphate materials, but with a resorption profile only slightly slower than conventional surgical-grade calcium sulfate. A canine bilateral defect model was used to compare restoration of defects treated with the modified calcium sulfate compared to treatment using conventional calcium sulfate pellets after 6, 13, and 26 weeks. The modified calcium sulfate pellets were as effective as conventional calcium sulfate pellets with regard to the area fraction and compressive strength of newly formed bone in the treated bone defects. Mechanical testing demonstrated that the initial compressive strength of the modified material was increased nearly three-fold compared to that of conventional surgical-grade calcium sulfate. This increase potentially allows for its use in a broader range of clinical applications, such as vertebral and subchondral defects.

  10. Preparation and characterization of calcium phosphate ceramics and Composites as bone substitutes

    OpenAIRE

    Zhang, Xing

    2007-01-01

    Marine CaCO₃ skeletons have tailored architectures created by nature, which give them structural support and other functions. For example, seashells have dense lamellar structures, while coral, cuttlebone and sea urchin spines have interconnected porous structures. In our experiments, seashells, coral and cuttlebone were hydrothermally converted to hydroxyapatite (HAP), and sea urchin spines were converted to Mg-substituted tricalcium phosphate [beta]-TCMP, while maintaining their original st...

  11. In vitro performance assessment of new brushite-forming Zn- and ZnSr-substituted beta-TCP bone cements.

    Science.gov (United States)

    Pina, S; Vieira, S I; Torres, P M C; Goetz-Neunhoeffer, F; Neubauer, J; da Cruz E Silva, O A B; da Cruz E Silva, E F; Ferreira, J M F

    2010-08-01

    The present study investigated the in vitro performance of brushite-forming Zn- and ZnSr-substituted beta-TCP bone cements in terms of wet mechanical strength and biological response. Quantitative phase analysis and structural refinement of the powdered samples were performed by X-ray powder diffraction and Rietveld refinement technique. Initial and final setting times of the cement pastes, measured using Gilmore needles technique, showed that ZnSrCPC sets faster than ZnCPC. The measured values of the wet strength after 48 h of immersion in PBS solution at 37 degrees C showed that ZnSrCPC cements are stronger than ZnCPC cements. Human osteosarcoma-derived MG63 cell line proved the nontoxicity of the cement powders, using the resazurin metabolic assay.

  12. Selenium-Substituted Hydroxyapatite/Biodegradable Polymer/Pamidronate Combined Scaffold for the Therapy of Bone Tumour

    Directory of Open Access Journals (Sweden)

    Ewa Oledzka

    2015-09-01

    Full Text Available The present study evaluated a new concept of combined scaffolds as a promising bone replacement material for patients with a bone tumour or bone metastasis. The scaffolds were composed of hydroxyapatite doped with selenium ions and a biodegradable polymer (linear or branched, and contained an active substance—bisphosphonate. For this purpose, a series of biodegradable polyesters were synthesized through a ring-opening polymerization of ε-caprolactone or d,l-lactide in the presence of 2-hydroxyethyl methacrylate (HEMA or hyperbranched 2,2-bis(hydroxymethylpropionic acid polyester-16-hydroxyl (bis-MPA initiators, substances often used in the synthesis of medical materials. The polymers were obtained with a high yield and a number-average molecular weight up to 45,300 (g/mol. The combined scaffolds were then manufactured by a direct compression of pre-synthesized hydroxyapatite doped with selenite or selenate ions, obtained polymer and pamidronate as a model drug. It was found that the kinetic release of the drug from the scaffolds tested in vitro under physiological conditions is strongly dependent on the physicochemical properties and average molecular weight of the polymers. Furthermore, there was good correlation with the hydrolytic biodegradation results of the scaffolds fabricated without drug. The preliminary findings suggest that the fabricated combined scaffolds could be effectively used for the sustained delivery of bioactive molecules at bone defect sites.

  13. Selenium-Substituted Hydroxyapatite/Biodegradable Polymer/Pamidronate Combined Scaffold for the Therapy of Bone Tumour.

    Science.gov (United States)

    Oledzka, Ewa; Sobczak, Marcin; Kolmas, Joanna; Nalecz-Jawecki, Grzegorz

    2015-09-14

    The present study evaluated a new concept of combined scaffolds as a promising bone replacement material for patients with a bone tumour or bone metastasis. The scaffolds were composed of hydroxyapatite doped with selenium ions and a biodegradable polymer (linear or branched), and contained an active substance-bisphosphonate. For this purpose, a series of biodegradable polyesters were synthesized through a ring-opening polymerization of ε-caprolactone or d,l-lactide in the presence of 2-hydroxyethyl methacrylate (HEMA) or hyperbranched 2,2-bis(hydroxymethyl)propionic acid polyester-16-hydroxyl (bis-MPA) initiators, substances often used in the synthesis of medical materials. The polymers were obtained with a high yield and a number-average molecular weight up to 45,300 (g/mol). The combined scaffolds were then manufactured by a direct compression of pre-synthesized hydroxyapatite doped with selenite or selenate ions, obtained polymer and pamidronate as a model drug. It was found that the kinetic release of the drug from the scaffolds tested in vitro under physiological conditions is strongly dependent on the physicochemical properties and average molecular weight of the polymers. Furthermore, there was good correlation with the hydrolytic biodegradation results of the scaffolds fabricated without drug. The preliminary findings suggest that the fabricated combined scaffolds could be effectively used for the sustained delivery of bioactive molecules at bone defect sites.

  14. Evaluation of bone substitutes for treatment of peri-implant bone defects: biomechanical, histological, and immunohistochemical analyses in the rabbit tibia

    Science.gov (United States)

    2016-01-01

    Purpose We sought to evaluate the effectiveness of bone substitutes in circumferential peri-implant defects created in the rabbit tibia. Methods Thirty rabbits received 45 implants in their left and right tibia. A circumferential bone defect (6.1 mm in diameter/4 mm depth) was created in each rabbit tibia using a trephine bur. A dental implant (4.1 mm × 8.5 mm) was installed after the creation of the defect, providing a 2-mm gap. The bone defect gaps between the implant and the bone were randomly filled according to the following groups: blood clot (CO), particulate Bio-Oss® (BI), and Bio-Oss® Collagen (BC). Ten animals were euthanized after periods of 15, 30, and 60 days. Biomechanical analysis by means of the removal torque of the implants, as well as histologic and immunohistochemical analyses for protein expression of osteocalcin (OC), Runx2, OPG, RANKL, and TRAP were evaluated. Results For biomechanics, BC showed a better biological response (61.00±15.28 Ncm) than CO (31.60±14.38 Ncm) at 30 days. Immunohistochemical analysis showed significantly different OC expression in CO and BC at 15 days, and also between the CO and BI groups, and between the CO and BC groups at 60 days. After 15 days, Runx2 expression was significantly different in the BI group compared to the CO and BC groups. RANKL expression was significantly different in the BI and CO groups and between the BI and BC groups at 15 days, and also between the BI and CO groups at 60 days. OPG expression was significantly higher at 60 days postoperatively in the BI group than the CO group. Conclusions Collectively, our data indicate that, compared to CO and BI, BC offered better bone healing, which was characterized by greater RUNX2, OC, and OPG immunolabeling, and required greater reversal torque for implant removal. Indeed, along with BI, BC presents promising biomechanical and biological properties supporting its possible use in osteoconductive grafts for filling peri-implant gaps. PMID:27382506

  15. Organoapatites: materials for artificial bone. II. Hardening reactions and properties.

    Science.gov (United States)

    Stupp, S I; Mejicano, G C; Hanson, J A

    1993-03-01

    This article reports on chemical reactions and the properties they generated in artificial bone materials termed "organoapatites." These materials are synthesized using methodology we reported in the previous article of this series. Two different processes were studied here for the transition from organoapatite particles to implants suitable for the restoration of the skeletal system. One process involved the hardening of powder compacts by beams of blue light derived from a lamp or a laser and the other involved pressure-induced interdiffusion of polymers. In both cases, the hardening reaction involved the formation of a polyion complex between two polyelectrolytes. In the photo-induced reaction an anionic electrolyte polymerizes to form the coulombic network and in the pressure-induced one, pressure forms the complex by interdiffusion of two polyions. Model reactions were studied using various polycations. Based on these results the organoapatite selected for the study was that containing dispersed poly(L-lysine) and sodium acrylate as the anionic monomer. The organomineral particles can be pressed at room temperature into objects of great physical integrity and hydrolytic stability relative to anorganic controls. The remarkable fact about these objects is that intimate molecular dispersion of only 2-3% by weight organic material provides integrity to the mineral network in an aqueous medium and also doubles its tensile strength. This integrity is essentially nonexistent in "anorganic" samples prepared by the same methodology used in organoapatite synthesis. The improvement in properties was most effectively produced by molecular bridges formed by photopolymerization. The photopolymerization leads to the "hardening" of pellets prepared by pressing of organoapatite powders. The reaction was found to be more facile in the microstructure of the organomineral, and it is potentially useful in the surgical application of organoapatites as artificial bone.

  16. Bone Formation in a Rat Tibial Defect Model Using Carboxymethyl Cellulose/BioC/Bone Morphogenic Protein-2 Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Sang-Heon Song

    2014-01-01

    Full Text Available The objective of this study was to assess whether carboxymethyl cellulose- (CMC- based hydrogel containing BioC (biphasic calcium phosphate (BCP; tricalcium phosphate (TCP : hydroxyapatite (Hap = 70 : 30 and bone morphogenic protein-2 (BMP-2 led to greater bone formation than CMC-based hydrogel containing BioC without BMP-2. In order to demonstrate bone formation at 4 and 8 weeks, plain radiographs, microcomputed tomography (micro-CT evaluation, and histological studies were performed after implantation of all hybrid materials on an 8 mm defect of the right tibia in rats. The plain radiographs and micro-CT analyses revealed that CMC/BioC/BMP-2 (0.5 mg led to much greater mineralization at 4 and 8 weeks than did CMC/BioC or CMC/Bio/BMP-2 (0.1 mg. Likewise, bone formation and bone remodeling studies revealed that CMC/BioC/BMP-2 (0.5 mg led to a significantly greater amount of bone formation and bone remodeling at 4 and 8 weeks than did CMC/BioC or CMC/BioC/BMP-2 (0.1 mg. Histological studies revealed that mineralized bone tissue was present around the whole circumference of the defect site with CMC/BioC/BMP-2 (0.5 mg but not with CMC/BioC or CMC/BioC/BMP-2 (0.1 mg at 4 and 8 weeks. These results suggest that CMC/BioC/BMP-2 hybrid materials induced greater bone formation than CMC/BioC hybrid materials. Thus, CMC/BioC/BMP-2 hybrid materials may be used as an injectable substrate to regenerate bone defects.

  17. 3D printing of mineral–polymer bone substitutes based on sodium alginate and calcium phosphate

    Science.gov (United States)

    Egorov, Aleksey A; Fedotov, Alexander Yu; Mironov, Anton V; Popov, Vladimir K; Zobkov, Yury V

    2016-01-01

    Summary We demonstrate a relatively simple route for three-dimensional (3D) printing of complex-shaped biocompatible structures based on sodium alginate and calcium phosphate (CP) for bone tissue engineering. The fabrication of 3D composite structures was performed through the synthesis of inorganic particles within a biopolymer macromolecular network during 3D printing process. The formation of a new CP phase was studied through X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. Both the phase composition and the diameter of the CP particles depend on the concentration of a liquid component (i.e., the “ink”). The 3D printed structures were fabricated and found to have large interconnected porous systems (mean diameter ≈800 μm) and were found to possess compressive strengths from 0.45 to 1.0 MPa. This new approach can be effectively applied for fabrication of biocompatible scaffolds for bone tissue engineering constructions. PMID:28144529

  18. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guangyong [Department of Orthopaedics, Taizhou Hospital of Zhejiang Province, Linhai Zhejiang, 317000 (China); Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Liu, Jianli [Trauma Center, Affiliated Hospital of Hainan Medical University, Haikou, Hainan, 570206 (China); Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China); Li, Fan; Pan, Zongyou; Ni, Xiao; Shen, Yue [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Xu, Huazi, E-mail: spinexu@163.com [Department of Orthopaedic Surgery, Second Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, 325000 (China); Huang, Qing, E-mail: huangqing@nimte.ac.cn [Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang, 315201 (China)

    2014-02-01

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6–12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration. - Highlights: • The mechanical strength and degradation rate of CSMPC composites are discussed. • The CSMPC composites exhibited good bioactivity to form bone-like apatite. • The CSMPC composites also show good biocompatibility.

  19. Bioactive ceramic-based materials with designed reactivity for bone tissue regeneration

    OpenAIRE

    Ohtsuki, Chikara; Kamitakahara, Masanobu; Miyazaki, Toshiki

    2009-01-01

    Bioactive ceramics have been used clinically to repair bone defects owing to their biological affinity to living bone; i.e. the capability of direct bonding to living bone, their so-called bioactivity. However, currently available bioactive ceramics do not satisfy every clinical application. Therefore, the development of novel design of bioactive materials is necessary. Bioactive ceramics show osteoconduction by formation of biologically active bone-like apatite through chemical reaction of t...

  20. Hierarcially biomimetic bone materials: from nanometer to millimeter

    Institute of Scientific and Technical Information of China (English)

    ZHANG W.; CUI F. Z.; LIAO S. S.

    2001-01-01

    @@ The bone composite was produced by biomimetic synthesis. It shows some features of natural bone in both composition and microstructure. And the collagen moleculars and the nano-crystal hydroxyapatite assemble into ultrastructure similar to natural bone. It possesses porous structure with porosity from 100μm to 500μm after mixed with PLA (poly lactic acid).

  1. Evaluation of bone response to synthetic bone grafting material treated with argon-based atmospheric pressure plasma

    Energy Technology Data Exchange (ETDEWEB)

    Beutel, Bryan G., E-mail: bryanbeutel@gmail.com; Danna, Natalie R.; Gangolli, Riddhi; Granato, Rodrigo; Manne, Lakshmiprada; Tovar, Nick; Coelho, Paulo G.

    2014-12-01

    Bone graft materials are utilized to stimulate healing of bone defects or enhance osseointegration of implants. In order to augment these capabilities, various surface modification techniques, including atmospheric pressure plasma (APP) surface treatment, have been developed. This in vivo study sought to assess the effect of APP surface treatment on degradation and osseointegration of Synthograft™, a beta-tricalcium phosphate (β-TCP) synthetic bone graft. The experimental (APP-treated) grafts were subjected to APP treatment with argon for a period of 60 s. Physicochemical characterization was performed by environmental scanning electron microscopy, surface energy (SE), and x-ray photoelectron spectroscopy analyses both before and after APP treatment. Two APP-treated and two untreated grafts were surgically implanted into four critical-size calvarial defects in each of ten New Zealand white rabbits. The defect samples were explanted after four weeks, underwent histological analysis, and the percentages of bone, soft tissue, and remaining graft material were quantified by image thresholding. Material characterization showed no differences in particle surface morphology and that the APP-treated group presented significantly higher SE along with higher amounts of the base material chemical elements on it surface. Review of defect composition showed that APP treatment did not increase bone formation or reduce the amount of soft tissue filling the defect when compared to untreated material. Histologic cross-sections demonstrated osteoblastic cell lines, osteoid deposition, and neovascularization in both groups. Ultimately, argon-based APP treatment did not enhance the osseointegration or degradation of the β-TCP graft. Future investigations should evaluate the utility of gases other than argon to enhance osseointegration through APP treatment. - Highlights: • Degradation/osseointegration of bone graft treated with argon-based APP is studied. • APP treatment did

  2. Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications.

    Science.gov (United States)

    Yang, Guangyong; Liu, Jianli; Li, Fan; Pan, Zongyou; Ni, Xiao; Shen, Yue; Xu, Huazi; Huang, Qing

    2014-02-01

    A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6-12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration.

  3. Degradability of injectable calcium sulfate/mineralized collagen-based bone repair material and its effect on bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonggang, E-mail: chenzg@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Kang, Lingzhi [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Meng, Qing-Yuan [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, Huanye [Department of Prosthodontics, School of Stomatology, China Medical University, Shenyang 110001 (China); Wang, Zhaoliang [Jinan Military General Hospital of PLA, Jinan 250031 (China); Guo, Zhongwu, E-mail: zwguo@sdu.edu.cn [National Glycoengineering Research Center, Shandong University, Jinan 250100 (China); Cui, Fu-Zhai, E-mail: cuifz@mail.tsinghua.edu.cn [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2014-12-01

    The nHAC/CSH composite is an injectable bone repair material with controllable injectability and self-setting properties prepared by introducing calcium sulfate hemihydrate (CSH) into mineralized collagen (nHAC). When mixed with water, the nHAC/CSH composites can be transformed into mineralized collagen/calcium sulfate dihydrate (nHAC/CSD) composites. The nHAC/CSD composites have good biocompatibility and osteogenic capability. Considering that the degradation behavior of bone repair material is another important factor for its clinical applications, the degradability of nHAC/CSD composites was studied. The results showed that the degradation ratio of the nHAC/CSD composites with lower nHAC content increased with the L/S ratio increase of injectable materials, but the variety of L/S ratio had no significant effect on the degradation ratio of the nHAC/CSD composites with higher nHAC content. Increasing nHAC content in the composites could slow down the degradation of nHAC/CSD composite. Setting accelerator had no significant effect on the degradability of nHAC/CSD composites. In vivo histological analysis suggests that the degradation rate of materials can match the growth rate of new mandibular bone tissues in the implanted site of rabbit. The regulable degradability of materials resulting from the special prescriptions of injectable nHAC/CSH composites will further improve the workability of nHAC/CSD composites. - Highlights: • The nHAC/CSH composite can be as an injectable bone repair material. • The L/S ratio and nHAC content have a significant effect on material degradability. • The degradability of bone materials can be regulated to match tissue repair. • The regulable degradability will further improve the workability of bone materials.

  4. 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

  5. Effect of a Bone Graft Substitute β Tricalcium Phosphate on Osteoblastic Genes mRNA Exprssion

    Institute of Scientific and Technical Information of China (English)

    QIU Tong; WANG Youfa; HAN Yinchao; JIANG Xin; LI Shipu

    2012-01-01

    To investigate the molecular aspects of osteoblastic interactions with β tricalcium phosphate (β-TCP) particles,human osteoblast-like MG-63 cells were cultured with β-TCP particles at a density of 6 mg/mL culture medium for 48 h.Then,the mRNA expression of selected genes were quantified by realtime polymerase chain reaction (PCR),including the attachment-related genes (α integrin and actin),the proliferation-related gene (c-jun),and the osteoblastic markers genes (type Ⅰ collagen,osteonectin,alkaline phosphatase,RUNX2 and osteoclain).The results showed that β-TCP particles (the average size 809 nm)significantly promote the attachment and the proliferation of MG-63 cells,and slightly enhance the osteoblastic differentiation based on the analyses of the related genes expression.This study provided scientific evidences to better reveal the underlines of functions of β-TCP in bone repair.

  6. Spin canting effect and microwave absorption properties of Sm–Mn substituted nanosized material

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq, Imran, E-mail: khanphysics@yahoo.com [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore (Pakistan); Naseem, Shahzad [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore (Pakistan); Naeem Ashiq, Muhammad [Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800 (Pakistan); Asif Iqbal, M.; Ali, Irshad [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Khan, M.A. [Department of Physics, BUITEMS, Quetta (Pakistan); Niaz, Shanawar [Department of Physics, University of Sargodha, Sargodha (Pakistan); Rana, M.U. [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore (Pakistan)

    2015-12-01

    In order to understand the substitutional effect of rare earth element Sm{sup 3+} and divalent Mn{sup 2+} on structural, magnetic and microwave absorption properties of hexagonal ferrites, a series of Sr{sub 2−x} Sm{sub x} Ni{sub 2} Fe{sub 28−y}Mn{sub y}O{sub 46} X-type hexagonal ferrites with concentration (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10 and y=0, 0.1, 0.2, 0.3, 0.4, 0.5) was synthesized by the sol–gel method. The XRD analysis shows that the material crystallized into single X-type hexagonal phase. The absorption bands at low wave number in FTIR curves are the characteristics of the X-type hexagonal ferrites. Decreasing trend in the magnetic properties with the substitution of Sm–Mn contents was also observed, which may be attributed to the oxidation of Mn{sup 2+} ions into Mn{sup 3+} ions and spin canting effect of rare earth element Sm{sup 3+}. The reflection loss peak shifted towards the low frequency and microwave absorption properties of the material enhanced with the substitution of Sm–Mn contents which reflects its applications in super high frequency (SHF) devices. The attenuation constant curves are in good agreement with the reflection loss peak. - Highlights: • A series of x-type hexagonal ferrites were prepared by sol–gel method. • The XRD analysis showed that the X-type hexagonal structure. • The c/a ratio of these samples falls in the range of X-type hexagonal ferrites. • The spin canting effect diminishes the magnetic properties. • The microwave absorption peak shifts towards the low frequency.

  7. Novel ceramic bone replacement material CeraBall seeded with human mesenchymal stem cells.

    NARCIS (Netherlands)

    Douglas, T.E.L.; Liu, Q.; Humpe, A.; Wiltfang, J.; Sivananthan, S.; Warnke, P.H.

    2010-01-01

    OBJECTIVES: Hydroxyapatite (HA) and tricalcium phosphate (TCP) are two very common ceramic materials for bone replacement. A recently developed material for bone replacement is CeraBall, which is a mixed HA-TCP scaffold available as porous spherical scaffolds of diameter 4 and 6 mm. Before their use

  8. Substitution of wastes for fuels and raw materials in high-temperature processes; Substitution von Brennstoffen und Rohstoffen durch Abfaelle in Hochtemperaturprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, R. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Energieverfahrenstechnik; Beckmann, M. [Clausthaler Umwelttechnik-Institut GmbH (CUTEC), Clausthal-Zellerfeld (Germany)

    1998-09-01

    The physical recycling and energy conversion of wastes has for a long time been a topic of discussion. Some of the most interesting questions in this connection concern specific applications such as the co-combustion of sewage sludge in power plants, substitution of plastic wastes for primary fuels in burning processes in the cement industry etc. This paper also undertakes a comparative study of different applications, giving additional consideration to the state of the art in thermal waste treatment. Different processes can of course only be compared by taking the entirety of expenditures on additives and auxiliary energy into account and assuming equal side constraints for all processes. A further requirement is that the waste materials` specific properties that are relevant to the application in question have to be taken into account. This concerns in particular the effects of the substitution of waste-derived fuels (secondary fuels) for primary fuels on, for example, heat transfer conditions during the combustion process, flow conditions, and the resultant temperature distribution, transport of feedstock, and specific energy expenditure. Secondary fuels must be suited for substitution in various respects, e.g. in their material properties, and their combustion and thermal behaviour. The present paper deals in particular with the requirements on wastes as substitutes for primary fuels with regard to combustion and thermal behaviour. For this purpose it briefly discusses some important aspects of heat transfer in firing plants and industrial furnaces. An important criterion in assessing fuel substitution is the energy exchange ratio, which expresses value of the substitute fuel relative to that of the primary fuel and should be duly considered when making comparative studies. Focussing on aspects of process engineering the paper also deals exemplarily with the influence of fuel substitution on, e.g. furnace temperature, exhaust gas quantities etc. in clinker

  9. Substitution of wastes for fuels and raw materials in high-temperature processes; Substitution von Brennstoffen und Rohstoffen durch Abfaelle in Hochtemperaturprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, R. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Energieverfahrenstechnik; Beckmann, M. [Clausthaler Umwelttechnik-Institut GmbH (CUTEC), Clausthal-Zellerfeld (Germany)

    1998-09-01

    The physical recycling and energy conversion of wastes has for a long time been a topic of discussion. Some of the most interesting questions in this connection concern specific applications such as the co-combustion of sewage sludge in power plants, substitution of plastic wastes for primary fuels in burning processes in the cement industry etc. This paper also undertakes a comparative study of different applications, giving additional consideration to the state of the art in thermal waste treatment. Different processes can of course only be compared by taking the entirety of expenditures on additives and auxiliary energy into account and assuming equal side constraints for all processes. A further requirement is that the waste materials` specific properties that are relevant to the application in question have to be taken into account. This concerns in particular the effects of the substitution of waste-derived fuels (secondary fuels) for primary fuels on, for example, heat transfer conditions during the combustion process, flow conditions, and the resultant temperature distribution, transport of feedstock, and specific energy expenditure. Secondary fuels must be suited for substitution in various respects, e.g. in their material properties, and their combustion and thermal behaviour. The present paper deals in particular with the requirements on wastes as substitutes for primary fuels with regard to combustion and thermal behaviour. For this purpose it briefly discusses some important aspects of heat transfer in firing plants and industrial furnaces. An important criterion in assessing fuel substitution is the energy exchange ratio, which expresses value of the substitute fuel relative to that of the primary fuel and should be duly considered when making comparative studies. Focussing on aspects of process engineering the paper also deals exemplarily with the influence of fuel substitution on, e.g. furnace temperature, exhaust gas quantities etc. in clinker

  10. Novel approaches to bone grafting: porosity, bone morphogenetic proteins, stem cells, and the periosteum.

    Science.gov (United States)

    Petrochenko, Peter; Narayan, Roger J

    2010-01-01

    The disadvantages involving the use of a patient's own bone as graft material have led surgeons to search for alternative materials. In this review, several characteristics of a successful bone graft material are discussed. In addition, novel synthetic materials and natural bone graft materials are being considered. Various factors can determine the success of a bone graft substitute. For example, design considerations such as porosity, pore shape, and interconnection play significant roles in determining graft performance. The effective delivery of bone morphogenetic proteins and the ability to restore vascularization also play significant roles in determining the success of a bone graft material. Among current approaches, shorter bone morphogenetic protein sequences, more efficient delivery methods, and periosteal graft supplements have shown significant promise for use in autograft substitutes or autograft extenders.

  11. [Reaction of bone tissue elements on synthetic bioresorbable materials based on lactic and glycolic acids].

    Science.gov (United States)

    Kulakov, A A; Grigor'ian, A S

    2014-01-01

    The aim of the study was to evaluate the adverse effects of synthetic polymeric bioresorbable materials based on lactic and glycolic acids on the bone tissue. The study was carried-out on 40 Wister-line rats. Four types of bioresorbable polymeric materials were implanted: PolyLactide Glycolide Acid (PLGA), Poly-L-Lactide Acid (PLLA); Poly-96L/4D-Lactide Acid (96/4 PLDLA); Poly-70L/30D-Lactide Acid (70/30 PLDLA). The results showed connective tissue formation (fibrointegration) bordering bone adjacent to implanted materials. This proved the materials to cause pathogenic influence on the bone which mechanisms are described in the article.

  12. Comparison of three calcium phosphate bone graft substitutes from biomechanical, histological, and crystallographic perspectives using a rat posterolateral lumbar fusion model.

    Science.gov (United States)

    Hu, Ming-Hsien; Lee, Pei-Yuan; Chen, Wen-Cheng; Hu, Jin-Jia

    2014-12-01

    This study evaluated the effectiveness of three calcium phosphate bone graft substitutes with different chemical compositions on spinal fusion using a rat posterolateral lumbar fusion model. Specifically, two recently developed non-dispersive tetracalcium phosphate/dicalcium phosphate anhydrous-based calcium phosphate cements (CPCs), namely a CPC consisting of equimolar amounts of the two compounds (nd-CPC) and a CPC consisting of a two-fold greater amount of dicalcium phosphate anhydrous (DCP-rich CPC), were compared with a commercial calcium phosphate bone graft (c-CPG) consisting of hydroxyapatite (60%) and β-tricalcium phosphate (40%). Single-level posterolateral lumbar fusion was performed at the L4-L5 vertebrae in fifteen adult rats (n=5 for each group). Spinal fusion was evaluated with radiographs, manual palpation, mechanical testing, micro-CT, and histology 8 weeks post-surgery. In particular, the crystallographic phases in the three substitutes were identified before and 8 weeks after their implantation. Manual palpation revealed stable constructs in nearly all of the spine specimens. The stiffness and bending load of fused spines in the two CPC groups were comparable to those in the c-CPG group. The radiographs specifically revealed implant resorption and bone remodeling in the DCP-rich CPC group. Analysis of 3D micro-CT images revealed that the bone volume ratio in the DCP-rich CPC group was significantly greater than those in the nd-CPC and c-CPG groups. Histology showed that the DCP-rich CPC group exhibited the highest degree of bone regeneration and osseointegration. Notably, DCP-rich CPC led to a pronounced phase transformation, generating the greatest amount of poorly crystalline apatite among the three groups, which together with adequate resorption may explain the aforementioned positive findings. We therefore conclude that of the bone graft substitutes considered, DCP-rich CPC has the greatest potential to be used in spinal fusion.

  13. Biofabrication of a PLGA-TCP-based porous bioactive bone substitute with sustained release of icaritin.

    Science.gov (United States)

    Xie, Xin-Hui; Wang, Xin-Luan; Zhang, Ge; He, Yi-Xin; Leng, Yang; Tang, Ting-Ting; Pan, Xiaohua; Qin, Ling

    2015-08-01

    A phytomolecule, icaritin, has been identified and shown to be osteopromotive for the prevention of osteoporosis and osteonecrosis. This study aimed to produce a bioactive poly (l-lactide-co-glycolide)-tricalcium phosphate (PLGA-TCP)-based porous scaffold incorporating the osteopromotive phytomolecule icaritin, using a fine spinning technology. Both the structure and the composition of icaritin-releasing PLGA-TCP-based scaffolds were evaluated by scanning electron microscopy (SEM). The porosity was quantified by both water absorption and micro-computed tomography (micro-CT). The mechanical properties were evaluated using a compression test. In vitro release of icaritin from the PLGA-TCP scaffold was quantified by high-performance liquid chromatography (HPLC). The attachment, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on the composite scaffold were evaluated. Both an in vitro cytotoxicity test and an in vivo test via muscular implantation were conducted to confirm the scaffold's biocompatibility. The results showed that the PLGA-TCP-icaritin composite scaffold was porous, with interconnected macro- (about 480 µm) and micropores (2-15 µm). The mechanical properties of the PLGA-TCP-icaritin scaffold were comparable with those of the pure PLGA-TCP scaffold, yet was spinning direction-dependent. Icaritin content was detected in the medium and increased with time. The PLGA-TCP-icaritin scaffold facilitated the attachment, proliferation and osteogenic differentiation of BMSCs. In vitro cytotoxicity test and in vivo intramuscular implantation showed that the composite scaffold had no toxicity with good biocompatibility. In conclusion, an osteopromotive phytomolecule, icaritin, was successfully incorporated into PLGA-TCP to form an innovative porous composite scaffold with sustained release of osteopromotive icaritin, and this scaffold had good biocompatibility and osteopromotion, suggesting its potential for orthopaedic

  14. Temperature dependent magnetic and microwave absorption properties of doubly substituted nanosized material

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq, Imran, E-mail: khanphysics@yahoo.com [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore (Pakistan); Naseem, Shahzad; Rana, M.U. [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore (Pakistan); Ashiq, Muhammad Naeem [Institute of chemical sciences, Bahauddin Zakariya University, Multan (Pakistan); Ali, Irshad [Department of Physics, Bahauddin Zakariya University, Multan (Pakistan)

    2015-07-01

    The sol gel method has been adopted to synthesize a series of X-type hexagonal ferrites with concentration Sr{sub 2−x} Gd{sub x} Ni{sub 2} Fe{sub 28−y}Cd{sub y}O{sub 46} (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10 and y=0, 0.1, 0.2, 0.3, 0.4, 0.5). The XRD analysis reveals the single phase of the prepared material and the lattice constants a (Å) and c (Å) varies with additives. The crystallite size of the present investigated ferrite is found in the range of 20–30 nm measured from TEM image. The enhancement in the magnetic properties (saturation magnetization, remanance magnetization and coercivity) can be observed with the increase of dopping concentration and the coercivity lies in the range of (484.22–887.47) G. The saturation and remanance magnetization decreases monotonically with the temperature which is the characteristic of the hexagonal ferrites. The Gd–Cd substituted sample possesses low values of complex relative permittivity and permeability than the pure samples. The material exhibits maximum microwave absorption −23 dB at 11.87 GHz and attenuation peak is in good agreement with the reflection loss value. The microwave absorption properties reflect the applications of this material in super high frequency devices (SHF). - Highlights: • A series of X-type hexagonal ferrites were prepared by Sol–gel method. • The XRD analysis showed that the X-type hexagonal structure. • The c/a ratio of these samples falls in the range of X-type hexagonal ferrites. • The magnetic properties improved with the increase of Gd–Cd contents. • The microwave absorption properties enhanced with Gd–Cd substitution.

  15. Bone marrow transplantation from unrelated donors: the impact of mismatches with substitutions at position 116 of the human leukocyte antigen class I heavy chain.

    Science.gov (United States)

    Ferrara, G B; Bacigalupo, A; Lamparelli, T; Lanino, E; Delfino, L; Morabito, A; Parodi, A M; Pera, C; Pozzi, S; Sormani, M P; Bruzzi, P; Bordo, D; Bolognesi, M; Bandini, G; Bontadini, A; Barbanti, M; Frumento, G

    2001-11-15

    The hypothesis was tested that amino acid substitutions in specific positions within human leukocyte antigen class I heavy chain would have different impacts on transplant-related mortality (TRM) in patients receiving transplanted bone marrow from unrelated donors. One hundred patients and their unrelated donors were typed by sequence-based typing for the human leukocyte antigen (HLA)-A, -B, and -C loci. All pairs were matched for DRB1, DRB3, DRB4, DRB5, DQA1, and DQB1 loci. Forty pairs were also matched at class I, and 60 pairs had one or more mismatches at class I loci. It was found that substitutions at positions 116 and 114 of class I heavy chain significantly increased the risk for TRM in univariate and bivariate Cox analyses. Conversely, no association between number of multiple mismatches or number of amino acid substitutions and TRM was seen when positions 116 and 114 were adjusted for. Variables predictive of TRM in multivariate Cox analysis were number of cells infused, diagnosis (chronic myeloid leukemia [CML] or non-CML), and amino acid substitution at position 116 or 152. The only variable predictive of severe acute graft-versus-host disease (GVHD) in multivariate Cox analysis was substitution at position 116. Actuarial risk for acute GVHD grade III-IV, TRM, and relapse in pairs with substitutions at position 116 (n = 37) compared to other pairs (n = 63) was, respectively, 36% versus 14% (P =.01), 59% versus 28% (P =.001), and 25% versus 31% (P =.4). In conclusion these data suggest that substitutions at position 116 of class I heavy chain increase the risk for acute GVHD and TRM in patients who receive transplanted bone marrow from unrelated donors.

  16. Emitting materials based on phenylanthracene-substituted naphthalene derivatives for organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Woo; Kim, Hye Jeong; Kim, Young Seok; Kim, Jwajin [Department of Chemistry, Sungkyunkwan University, Suwon 440‐746 (Korea, Republic of); Lee, Song Eun; Lee, Ho Won [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@wow.hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon 440‐746 (Korea, Republic of)

    2015-09-15

    This study reports the emitting materials based on phenylanthracene-substituted naphthalene derivatives to achieve efficient electroluminescent properties for OLED applications. An OLED device using 4,4′-bis(10-phenylanthracen-9-yl)-1,1′-binaphthalene exhibited the blue emission with the CIE coordinates of (0.19, 0.16) and efficient electroluminescent properties with the luminance, power and external quantum efficiency of 1.70 cd/A, 0.79 lm/W and 1.26% at 20 mA/cm{sup 2}, respectively. Also, the other device using 1,4-bis(10-phenylanthracene-9-yl)naphthalene exhibited white emission with the CIE coordinates of (0.34, 0.43) at 7V, respectively. This device exhibits the luminance, power and external quantum efficiency of 2.22 cd/A, 1.13 lm/W and 0.86% at 20 mA/cm{sup 2}, respectively. - Highlights: • We synthesized fluorescent materials based on phenylanthracene derivatives. • Electroluminescence properties of these materials depend on the molecular structures. • These blue and white materials have great potential for application in OLEDs.

  17. Synthetic hydroxyapatite obtaining using three different methods and characterization to use it as bone substitute

    OpenAIRE

    2012-01-01

    El método de obtención de la hidroxiapatita (HAp) para ser utilizada como sustituto óseo, debe ofrecer un producto de alta pureza, rendimiento, rapidez y bajo costo, y contar con propiedades como bioactividad, biocompatibilidad, osteoconductividad y unión directa al hueso. En este trabajo se elaboró HAp sintética mediante tres métodos reportados en la literatura de vía sinterización y vía precipitación. El material obtenido se caracterizó por espectrometría de absorción atómica (AAS), espectr...

  18. A high performance layered transition metal oxide cathode material obtained by simultaneous aluminum and iron cationic substitution

    Science.gov (United States)

    El Mofid, Wassima; Ivanov, Svetlozar; Konkin, Alexander; Bund, Andreas

    2014-12-01

    The method of self-combustion synthesis was applied to prepare double Al- and Fe-substituted LiNi0.6Mn0.2Co0.15Al0.025Fe0.025O2 (NMCAF) and non-substituted LiNi0.6Mn0.2Co0.2O2 (NMC-3:1:1) cathode materials for lithium ion batteries. The novel NMCAF structure obtained by simultaneous cationic substitution showed an improved capacity and high stability during electrochemical cycling. X-ray diffraction patterns proved that both materials have a layered α-NaFeO2 type structure with a good hexagonal ordering. It was found that NMCAF has increased a and c lattice parameters due to a structural expansion caused by Al and Fe ion substitution. Rietveld refinement analysis revealed a significant decrease of the cationic mixing after the metal substitution, suggesting a structural stabilization. Electron paramagnetic resonance (EPR) spectroscopy showed that Al and Fe substitution markedly influenced the EPR spectrum of NMC-(3:1:1). The EPR spectral lines of both materials are attributed to Mn4+ and Ni2+ present in the structure. The change in the Ni2+ line after the metal substitution suggests a redistribution of the Ni ions in the structure, which can be related to the diminished cation mixing in the NMCAF. The improved electrochemical behavior of NMCAF is closely connected to the stabilization of the layered structure and the reduction of the cation mixing after metal substitution.

  19. Manufacturing of individual biodegradable bone substitute implants using selective laser melting technique.

    Science.gov (United States)

    Lindner, Markus; Hoeges, Simon; Meiners, Wilhelm; Wissenbach, Konrad; Smeets, Ralf; Telle, Rainer; Poprawe, Reinhart; Fischer, Horst

    2011-06-15

    The additive manufacturing technique selective laser melting (SLM) has been successfully proved to be suitable for applications in implant manufacturing. SLM is well known for metal parts and offers direct manufacturing of three-dimensional (3D) parts with high bulk density on the base of individual 3D data, including computer tomography models of anatomical structures. Furthermore, an interconnecting porous structure with defined and reproducible pore size can be integrated during the design of the 3D virtual model of the implant. The objective of this study was to develop the SLM processes for a biodegradable composite material made of β-tricalcium phosphate (β-TCP) and poly(D, L)-lactide (PDLLA). The development of a powder composite material (β-TCP/PDLLA) suitable for the SLM process was successfully performed. The microstructure of the manufactured samples exhibit a homogeneous arrangement of ceramic and polymer. The four-point bending strength was up to 23 MPa. The X-ray diffraction (XRD) analysis of the samples confirmed β-TCP as the only present crystalline phase and the gel permeations chromatography (GPC) analysis documented a degradation of the polymer caused by the laser process less than conventional manufacturing processes. We conclude that SLM presents a new possibility to manufacture individual biodegradable implants made of β-TCP/PDLLA.

  20. Comparison of three calcium phosphate bone graft substitutes from biomechanical, histological, and crystallographic perspectives using a rat posterolateral lumbar fusion model

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ming-Hsien [Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Orthopedics, Show-Chwan Memorial Hospital, Changhua 50544, Taiwan (China); Department of Orthopedic Surgery, Faculty of Medicine, National Yang-Ming University, Taipei 112, Taiwan (China); Lee, Pei-Yuan [Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Orthopedics, Show-Chwan Memorial Hospital, Changhua 50544, Taiwan (China); Chen, Wen-Cheng, E-mail: wincheng0925@yahoo.com.tw [Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Hu, Jin-Jia, E-mail: jjhu@mail.ncku.edu.tw [Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Medical Device Innovation Center, National Cheng Kung University, Tainan 701, Taiwan (China)

    2014-12-01

    This study evaluated the effectiveness of three calcium phosphate bone graft substitutes with different chemical compositions on spinal fusion using a rat posterolateral lumbar fusion model. Specifically, two recently developed non-dispersive tetracalcium phosphate/dicalcium phosphate anhydrous-based calcium phosphate cements (CPCs), namely a CPC consisting of equimolar amounts of the two compounds (nd-CPC) and a CPC consisting of a two-fold greater amount of dicalcium phosphate anhydrous (DCP-rich CPC), were compared with a commercial calcium phosphate bone graft (c-CPG) consisting of hydroxyapatite (60%) and β-tricalcium phosphate (40%). Single-level posterolateral lumbar fusion was performed at the L4–L5 vertebrae in fifteen adult rats (n = 5 for each group). Spinal fusion was evaluated with radiographs, manual palpation, mechanical testing, micro-CT, and histology 8 weeks post-surgery. In particular, the crystallographic phases in the three substitutes were identified before and 8 weeks after their implantation. Manual palpation revealed stable constructs in nearly all of the spine specimens. The stiffness and bending load of fused spines in the two CPC groups were comparable to those in the c-CPG group. The radiographs specifically revealed implant resorption and bone remodeling in the DCP-rich CPC group. Analysis of 3D micro-CT images revealed that the bone volume ratio in the DCP-rich CPC group was significantly greater than those in the nd-CPC and c-CPG groups. Histology showed that the DCP-rich CPC group exhibited the highest degree of bone regeneration and osseointegration. Notably, DCP-rich CPC led to a pronounced phase transformation, generating the greatest amount of poorly crystalline apatite among the three groups, which together with adequate resorption may explain the aforementioned positive findings. We therefore conclude that of the bone graft substitutes considered, DCP-rich CPC has the greatest potential to be used in spinal fusion

  1. Temperature dependent magnetic and microwave absorption properties of doubly substituted nanosized material

    Science.gov (United States)

    Sadiq, Imran; Naseem, Shahzad; Rana, M. U.; Ashiq, Muhammad Naeem; Ali, Irshad

    2015-07-01

    The sol gel method has been adopted to synthesize a series of X-type hexagonal ferrites with concentration Sr2-x Gdx Ni2 Fe28-yCdyO46 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10 and y=0, 0.1, 0.2, 0.3, 0.4, 0.5). The XRD analysis reveals the single phase of the prepared material and the lattice constants a (Å) and c (Å) varies with additives. The crystallite size of the present investigated ferrite is found in the range of 20-30 nm measured from TEM image. The enhancement in the magnetic properties (saturation magnetization, remanance magnetization and coercivity) can be observed with the increase of dopping concentration and the coercivity lies in the range of (484.22-887.47) G. The saturation and remanance magnetization decreases monotonically with the temperature which is the characteristic of the hexagonal ferrites. The Gd-Cd substituted sample possesses low values of complex relative permittivity and permeability than the pure samples. The material exhibits maximum microwave absorption -23 dB at 11.87 GHz and attenuation peak is in good agreement with the reflection loss value. The microwave absorption properties reflect the applications of this material in super high frequency devices (SHF).

  2. Bone Adaptation Around Orthopaedic Implants of Varying Materials

    DEFF Research Database (Denmark)

    Bagge, Mette

    1998-01-01

    The bone adaptation around orthopaedic implants is simulated using a three-dimensional finite element model. The remodeling scheme has its origin in optimization methods, and includes anisotropy and time-dependent loading......The bone adaptation around orthopaedic implants is simulated using a three-dimensional finite element model. The remodeling scheme has its origin in optimization methods, and includes anisotropy and time-dependent loading...

  3. [Plants' materials and synthetic agonists of cannabinoid receptors use as a substitute of Marihuana, appearing in a current forensic toxicology practice of evidence materials].

    Science.gov (United States)

    Geppert, Bogna; Tezyk, Artur; Florek, Ewa; Zaba, Czesław

    2010-01-01

    Cannabis sativa species Indica (Marihuana) is nowadays one of the most common plant drug, with psychoactive activity, presently appearing on the illegal market in Poland. It is reported that frequency of securing evidential materials so called substitute of Marihuana, is growing rapidly during the last few years. The substitutes of Marihuana occurring on the market are of natural or synthetic origins, for example different species of raw plants' materials having action similar to Cannabis or raw plants' materials with no psychoactive properities but with an addition of components so called synthetic cannabinoids. The review presents recent developments in drug market and current problems of forensic toxicology on the example of Marihuana.

  4. Facile green synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin nanocomposite in the dual acting fluorine-containing ionic liquid medium for bone substitute applications

    Energy Technology Data Exchange (ETDEWEB)

    Jegatheeswaran, S. [Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi-3, Tamil Nadu (India); Selvam, S. [Laser and Sensor Application Laboratory, Pusan National University, Busan 609735 (Korea, Republic of); Sri Ramkumar, V. [Deptartment of Environmental Biotechnology, School of Environmental, Sciences, Bharathidasan University, Tiruchirappalli, Tamilnadu (India); Sundrarajan, M., E-mail: sundrarajan@yahoo.com [Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemical Sciences, Alagappa University, Karaikudi-3, Tamil Nadu (India)

    2016-05-15

    Highlights: • Fluorine based ionic liquid was highly influenced the morphological structure of nanocomposites. • These composites has been motivated controlled release of silver nanoparticles for uniform antibacterial activity. • These material has given excellent antibacterial biofilm activity and favourable cytotoxical behavior on the human osteosarcoma (MG-63) cells. • These material has been highly suitable for bone substitute appliactions. - Abstract: A novel green route has approached for the synthesis of silver doped fluor-hydroxyapatite/β-cyclodextrin composite by the assistance of fluorine-based ionic liquid. The selected [BMIM]BF{sub 4} ionic liquid for this work plays a dual role as fluoride source and templating agent. It helps to improve the crystalline structures and the shape of the composites. The crystallinity, surface morphology, topographical studies of the synthesized composite were validated. The XRD results of the composite show typical Ag reflection peaks at 38.1°, 44.2° and 63.4°. The ionic liquid assisted composite displayed the hexagonal shaped HA particles, which are surrounded by spherical nano-Ag particles and these particles are uniformly dispersed in the β-cyclodextrin matrix in both horizontal and cross sections from surface morphology observations. The Ionic liquid assisted silver doped fluor-hydroxyapatite/β-cyclodextrin composite exhibited very good antibacterial activities against Escherichia coli, Salmonella typhi, Klebsiella pneumonia and Serratia liquefaciens pathogens. The antibacterial proficiencies were established using Confocal Laser Scanning Microscopic developed biofilms images and bacterial growth curve analysis. The cytotoxicity results of the ionic liquid assisted composite analyzed by cell proliferation in vitro studies using human osteosarcoma cell line (MG-63) and this study has shown excellent biocompatibility.

  5. The bone matrix protein secreted phosphoprotein 24 kD (Spp24): bone metabolism regulator and starting material for biotherapeutic materials.

    Science.gov (United States)

    Murray, Samuel S; Wang, Jeffrey C; Duarte, Maria Eugenia Leite; Zhao, Ke-Wei; Tian, Haijun; Francis, Timothy; Brochmann Murray, Elsa J

    2015-05-01

    Secreted phosphoprotein 24 kD (Spp24) is a bone matrix protein that appears to be derived primarily from the liver and delivered to other tissues in a protective complex. A significant role in bone growth and turnover is suggested by genetic studies that associate the gene locus (SPP2) with bone mineral density and bone quality. The function of this protein in the normal bone environment is unknown but clues are given by the fact that Spp24, or proteolytic products of Spp24, bind cytokines of the TGF-β superfamily and also activate intracellular signaling pathways. Several potential biotherapeutics have been engineered from this protein including materials that enhance BMP-induced bone healing and, on the other hand, materials that inhibit BMPs in clinical situations where this is called for such as reducing BMP-induced inflammation and inhibiting tumors dependent on BMP autocrine systems. As understanding of the structure and function of this protein increases, more opportunities for rationally developed therapeutics will become apparent.

  6. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    Energy Technology Data Exchange (ETDEWEB)

    Herlin, Maria, E-mail: maria.herlin@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Finnilä, Mikko A.J., E-mail: mikko.finnila@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Zioupos, Peter, E-mail: p.zioupos@cranfield.ac.uk [Biomechanics Laboratories, Department of Engineering and Applied Science, Cranfield University, Shrivenham SN6 8LA (United Kingdom); Aula, Antti, E-mail: antti.aula@gmail.com [Department of Medical Physics, Imaging Centre, Tampere University Hospital, Tampere (Finland); Department of Biomedical Engineering, Tampere University of Technology, Tampere (Finland); Risteli, Juha, E-mail: juha.risteli@ppshp.fi [Department of Clinical Chemistry, Oulu University Hospital, Oulu (Finland); Miettinen, Hanna M., E-mail: hanna.miettinen@crl.com [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Jämsä, Timo, E-mail: timo.jamsa@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Diagnostic Radiology, Oulu University Hospital, Oulu (Finland); Tuukkanen, Juha, E-mail: juha.tuukkanen@oulu.fi [Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Korkalainen, Merja, E-mail: merja.korkalainen@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Håkansson, Helen, E-mail: Helen.Hakansson@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Viluksela, Matti, E-mail: matti.viluksela@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Department of Environmental Science, University of Eastern Finland, Kuopio (Finland)

    2013-11-15

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr{sup −/−}) and wild-type (Ahr{sup +/+}) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr{sup +/+} mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr{sup −/−} mice displayed a slightly modified bone phenotype as compared with untreated Ahr{sup +/+} mice, while TCDD exposure caused only a few changes in bones of Ahr{sup −/−} mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr{sup +/+} mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation

  7. Preparation of porous PLA/DBM composite biomaterials and experimental research of repair rabbit radius segmental bone defect.

    Science.gov (United States)

    Zhang, Yumin; Wang, Jianru; Wang, Jue; Niu, Xiaojun; Liu, Jianchun; Gao, Lan; Zhai, Xiaoyan; Chu, Kaibo

    2015-12-01

    Bone substitutes are used in wide range of orthopaedic application. An ideal bone substitute should exhibit superior osteoinductive and osteoconductive properties. Neither bio-derived materials nor synthetic materials can meet the needs of an ideal bone substitute. Preparation of composite materials is a promising way to improve properties of biomaterial. In this study, the porous poly lactic acid (PLA)/demineralized bone matrix (DBM) composite biomaterials prepared by supercritical CO2 technique were implanted to repair rabbit radius segmental bone defect. By comparing with PLA and bone autograft, the X-ray result and histological analysis showed the repair effect of PLA/DBM porous composite materials is significantly better than that of the PLA group and the blank control group, and is similar to autologous bone. The PLA/DBM can promote the healing of bone defects and can be used as a kind of ideal alternative materials to repair bone defects.

  8. Preparation and physicochemical properties of scaffold materials of heterogeneous deproteinized bone

    Institute of Scientific and Technical Information of China (English)

    LIU Lei; LI Qi-hong; TANG Kang-lai; YANG Liu; JIAN Yue-kui

    2007-01-01

    Objective:To prepare and observe the physicochemical properties of scaffold materials of heterogeneous deproteinized tissue-engineered bone.Methods:Deproteinized bone was made through a series of physicochemical treatments in pig ribs and analyzed with histological observation,scanning electron microscopy, infrared spectrum, X-ray diffraction and energy dispersive analysis, Kjeldahl determination and mechanics analysis.Results:Interstitial collagen fiber was positive and mucin was negative in deproteinized bone,but,both were positive in fresh bone. Deproteinized bone maintained natural pore network.Its pore size was 472.51 μm±7.02μm and the porosity was 78.15 % ± 6.45 %.The results of infrared spectrum showed that collagen was present in deproteinized bone.Both fresh and deproteinized bone had curve of hydroxyapatite.The Ca/P ratios were 1.71 ±0.95and 1.68 ± 0.76 ( P > 0.05 ),and the protein contents were 26.6% ± 2.23% and 19.1% ± 2.14% (P < 0.05)in fresh and deproteinized bone,respectively.There was no significant difference of destruction load under compression and maximal destruction load between fresh and deproteinized bone (P > 0.05).The elastic modulus was higher in deproteinized bone than that in fresh bone (P < 0.05).Conclusions:Physicochemical properties and mechanic strength of deproteinized tissue-engineered bone meet the demands of ideal scaffold materials. But,its immunogenicity should be observed through further experiments for its clinical applications.

  9. Evaluation of tissue-equivalent materials to be used as human brain tissue substitute in dosimetry for diagnostic radiology

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, C.C., E-mail: cassio.c.ferreira@gmail.co [Departamento de Fisica, Universidade Federal de Sergipe, Postal Code 353, Sergipe-SE 49100-000 (Brazil); Ximenes Filho, R.E.M., E-mail: raimundoximenes@hotmail.co [Departamento de Fisica, Universidade Federal de Sergipe, Postal Code 353, Sergipe-SE 49100-000 (Brazil); Vieira, J.W., E-mail: jwvieira@br.inter.ne [Centro Federal de Educacao Tecnologica de Pernambuco (CEFET-PE), Av. Professor Luiz Freire, 500 Curado, CEP 50740-540, Recife (Brazil); Escola Politecnica de Pernambuco, Universidade de Pernambuco (EPP/UPE), Rua Benfica, 455, Madalena, CEP 50720-001, Recife (Brazil); Tomal, A., E-mail: alessandratomal@pg.ffclrp.usp.b [Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, Ribeirao Preto-SP 14040-90 (Brazil); Poletti, M.E., E-mail: poletti@ffclrp.usp.b [Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, Ribeirao Preto-SP 14040-90 (Brazil); Garcia, C.A.B., E-mail: cgarcia@ufs.b [Departamento de Quimica, Universidade Federal de Sergipe, Postal Code 353, Sergipe-SE 49100-000 (Brazil); Maia, A.F., E-mail: afmaia@ufs.b [Departamento de Fisica, Universidade Federal de Sergipe, Postal Code 353, Sergipe-SE 49100-000 (Brazil)

    2010-08-15

    Tissue-equivalent materials to be used as substitutes for human brain tissue in dosimetry for diagnostic radiology have been investigated in terms of calculated total mass attenuation coefficient ({mu}/{rho}), calculated mass energy-absorption coefficient ({mu}{sub en}/{rho}) and absorbed dose. Measured linear attenuation coefficients ({mu}) have been used for benchmarking the calculated total mass attenuation coefficient ({mu}/{rho}). The materials examined were bolus, nylon (registered) , orange articulation wax, red articulation wax, PMMA (polymethylmethacrylate), bees wax, paraffin I, paraffin II, pitch and water. The results show that water is the best substitute for brain among the materials investigated. The average percentage differences between the calculated {mu}/{rho} and {mu}{sub en}/{rho} coefficients for water and those for brain were 1.0% and 2.5%, respectively. Absorbed doses determined by Monte Carlo methods confirm water as being the best brain substitute to be used in dosimetry for diagnostic radiology, showing maximum difference of 0.01%. Additionally this study showed that PMMA, a material often used for the manufacturing of head phantoms for computed tomography, cannot be considered to be a suitable substitute for human brain tissue in dosimetry.

  10. A nano-hydroxyapatite--pullulan/dextran polysaccharide composite macroporous material for bone tissue engineering.

    Science.gov (United States)

    Fricain, Jean Christophe; Schlaubitz, Silke; Le Visage, Catherine; Arnault, Isabelle; Derkaoui, Sidi Mohammed; Siadous, Robin; Catros, Sylvain; Lalande, Charlotte; Bareille, Reine; Renard, Martine; Fabre, Thierry; Cornet, Sandro; Durand, Marlène; Léonard, Alain; Sahraoui, Nouredine; Letourneur, Didier; Amédée, Joëlle

    2013-04-01

    Research in bone tissue engineering is focused on the development of alternatives to allogenic and autologous bone grafts that can stimulate bone healing. Here, we present scaffolds composed of the natural hydrophilic polysaccharides pullulan and dextran, supplemented or not with nanocrystalline hydroxyapatite particles (nHA). In vitro studies revealed that these matrices induced the formation of multicellular aggregates and expression of early and late bone specific markers with human bone marrow stromal cells in medium deprived of osteoinductive factors. In absence of any seeded cells, heterotopic implantation in mice and goat, revealed that only the composite macroporous scaffold (Matrix + nHA) (i) retained subcutaneously local growth factors, including Bone Morphogenetic Protein 2 (BMP2) and VEGF165, (ii) induced the deposition of a biological apatite layer, (iii) favored the formation of a dense mineralized tissue subcutaneously in mice, as well osteoid tissue after intramuscular implantation in goat. The composite scaffold was thereafter implanted in orthotopic preclinical models of critical size defects, in small and large animals, in three different bony sites, i.e. the femoral condyle of rat, a transversal mandibular defect and a tibial osteotomy in goat. The Matrix + nHA induced a highly mineralized tissue in the three models whatever the site of implantation, as well as osteoid tissue and bone tissue regeneration in direct contact to the matrix. We therefore propose this composite matrix as a material for stimulating bone cell differentiation of host mesenchymal stem cells and bone formation for orthopedic and maxillofacial surgical applications.

  11. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure on bone material properties.

    Science.gov (United States)

    Finnilä, Mikko A J; Zioupos, Peter; Herlin, Maria; Miettinen, Hanna M; Simanainen, Ulla; Håkansson, Helen; Tuukkanen, Juha; Viluksela, Matti; Jämsä, Timo

    2010-04-19

    Dioxins are known to decrease bone strength, architecture and density. However, their detailed effects on bone material properties are unknown. Here we used nanoindentation methods to characterize the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on nanomechanical behaviour of bone matrix. Pregnant rats were treated with a single intragastric dose of TCDD (1 microg/kg) or vehicle on gestational day 11. Tibias of female offspring were sampled on postnatal day (PND) 35 or 70, scanned at mid-diaphysis with pQCT, and evaluated by three-point bending and nanoindentation. TCDD treatment decreased bone mineralization (p<0.05), tibial length (p<0.01), cross-sectional geometry (p<0.05) and bending strength (p<0.05). Controls showed normal maturation pattern between PND 35 and 70 with decreased plasticity by 5.3% and increased dynamic hardness, storage and complex moduli by 26%, 13% and 12% respectively (p<0.05), while similar maturation was not observed in TCDD-exposed pups. In conclusion, for the first time, we demonstrate retardation of bone matrix maturation process in TCDD-exposed animals. In addition, the study confirms that developmental TCDD exposure has adverse effects on bone size, strength and mineralization. The current results in conjunction with macromechanical behaviour suggest that reduced bone strength caused by TCDD is more associated with the mineralization and altered geometry of bones than with changes at the bone matrix level.

  12. Study of calcium carbonate eggshell powder for potential use as bone substitute%碳磷灰石鸡蛋壳粉作为骨修复材料的初步研究

    Institute of Scientific and Technical Information of China (English)

    王淑敏; 张珂; 俞立英; 周鸿国; 丁亚通; 蔡意达

    2014-01-01

    Objective To develop a new bone substitute derived from avian eggshell (ES) using micro-wave processing and observe its abilities of bone formation. Methods Calcium carbonate ES powder was pre-pared by microwave method with different heating time. The physicochemical characteristics of the new materials with or without microwave heating were analyzed by SEM、EDXA、XRD、FT-IR . A pilot animal study was conducted by creating standard defects of 5 mm diameter on parietal bone of New Zealand rabbits. The defects were filled with 60 min microwave heated ES powder whereas using microwave untreated ES powder and Bio-Oss in comparison. After 8 weeks new bone formation of defects were observed. Results SEM, XRD, FT-IR and EDXA analysis showed the micromorphology of the new materials turned from needle-like to ball-like structures as the microwave heating time prolonged. The characteristic peak of calcium carbonate was also increased at the same time. Carbon, phosphorus and calcium were confirmed in the new material as well. Animal study showed 5 mm defects on parietal bone filled with calcium carbonate ES powder had more calcified bone formation and less uncalcified new bone. Conclusions The study demonstrated the efficient use of microwave in converting ES powder from natural CaCO3 into calcium carbonate. The new material might be a potential bone substitute.%目的:研制一种新型的碳磷灰石骨修复材料,初步观察其成骨作用。方法:以鸡蛋壳为原料,采用微波法制备不同加热条件下的骨修复材料,利用扫描电镜(SEM)、X射线衍射仪(XRD)、傅立叶红外(FT-IR)和能谱分析(EDXA)手段,表征微波处理前后材料的理化性能。进一步选用新西兰兔制备直径5mm的颅骨全层缺损区,以未经微波处理的鸡蛋壳粉及Bio-Oss作为对照,充填经微波处理后的新型骨修复材料,8周后观察新生骨的生成情况。结果:SEM, XRD, FT-IR和EDXA分析证实:

  13. A scintigraphic study of composited bone substitute in the repair of bone defect of femoral head%复合人工骨修复股骨头骨缺损的影像学研究

    Institute of Scientific and Technical Information of China (English)

    同志勤; 徐小良; 王坤正; 宋厂义

    2001-01-01

    Objective To evaluate the effect of bBMP-collagen-coral composited bone substitute in treatment of osteonecrosis of the femoral head(ONFH).Methods Canine bone defect of bilateral femoral head was established,They were devided into 4 groups:Ⅰ.composited bone substitute group(n=5),Ⅱ.muscle pedicle bone group (n=5),Ⅲ.simple coral group(n=4),Ⅳ.control group:contralateral hip(n=14).Roentgenography,Scintigraphy,MRI,CT were examined and studied at various time.Results ①Scintigraphic changes:In group Ⅰ,static bone image showed increased radionuclide uptake,but blood flow and blood-pool image didn't show in 6 and 12 week;②MRI:There was much more new bone formation in the bone defect of group Ⅰ;In group Ⅳ,there was fatty bone marrow which was surrounded with sclerotic bone;③Resules of roentgenographic and CT:In 14-16 weeks,in group Ⅰ,the coral was absorbed and most of the bone defects were closed completely;In the rest groups,part of each bone defect was remained except that in group Ⅳ,cystic sclerosis was formed.Conclusion The composited bone substitute possesses a superior osteoinductivity and osteoconductivity in the repair of bone defect of femoral head,but it can't improve the revascularization of ONFH.%目的研究用复合人工骨治疗股骨头坏死的效果。方法建立双侧股骨头内骨缺损模型,并分为4组:bBMP-胶原-珊瑚复合人工骨组(5侧)、肌骨瓣组(5侧)、单纯珊瑚组(4侧)、对照组(14侧,为以上各组的对侧)。造模及植入后定时行X线、核素骨显像、MRI及CT检查。结果①核素骨显像示:6周及12周,Ⅰ组股骨头核素摄取量静态相头/干比升高,但血流相及血池相不升高。②MRI:10周示Ⅰ组骨缺损内多量新生骨形成,Ⅳ组骨缺损内囊腔中为脂肪性信号,周围为低信号的硬化带。③拍片及CT示:14~16周,Ⅰ组骨缺损大多完全闭合,珊瑚已吸收,其余各组骨缺损部分残

  14. Characterization of a Composite Material to Mimic Human Cranial Bone

    Science.gov (United States)

    2015-09-01

    a general population. These file formats can be sent directly to additive manufacturing machines , generically referred to as 3-D printers, to...Illustration of the SLA additive manufacturing process. The SLA machine used in this study to manufacture specimens was a Viper Si (3D Systems, Rock...architectures while possessing physical and mechanical characteristics similar to that of bone. We are utilizing additive manufacturing , more generally

  15. Bone

    Science.gov (United States)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  16. The Effects of Surface Properties of Nanostructured Bone Repair Materials on Their Performances

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2015-01-01

    Full Text Available Nanotechnology has been expected to be an extraordinarily promising method for bone repair. Meanwhile, the promise of nanobiomaterials for therapeutic applications has been widely reported, and a lot of studies have been made in terms of repairing bone using nanomaterials accompanied by rapid development of nanotechnology. Compared with conventional biomaterials, nanostructured implants have been shown to possess positive effects on cellular functions because of their unique surface properties, such as nanotopography, increased wettability, larger surface area, and microenvironment similar to extracellular matrix. Moreover, many positive cellular responses have been found to take place at the interface between nanostructured implants and host bone. In this paper, we will give a review about the effects of surface properties of nanostructured bone repair materials on their performances in terms of several aspects and a detailed interpretation or introduction on the specific cellular recognitions at the interface between nanostructured implants and host bone.

  17. Long-term stability of surgical bone regenerative procedures of peri-implantitis lesions in a prospective case-control study over three years

    OpenAIRE

    2011-01-01

    Abstract Objectives: To evaluate the extent of bone fill over three years following surgical treatment of peri-implantitis with bone grafting with or without a membrane. Material & Methods: In a non-submerged wound healing mode, 15 subjects with 27 implants were treated with a bone substitute (Algipore?) alone, and 17 subjects with 29 implants were treated with the bone substitute and a resorbable membrane (Osseoquest?). Implants with radiographic bone loss ?1.8 mm following the...

  18. [Effect of periodontal regeneration using collagen-coated synthetic bone implant materials. Histopathological study].

    Science.gov (United States)

    Sugaya, A

    1989-09-01

    Granulated artificial bone implant materials such as hydroxyapatite (HAP) and tricalcium phosphate (TCP) have been frequently used in attempts to restore periodontal tissue lost as a result periodontitis. However, these materials are considered insufficient for the maintenance and stability of granules at sites losing bone, for active bone formation, or for periodontal ligament regeneration. We have now developed a complex consisting of HAP or TCP coated with atelocollagen (which has recently received attention as a biomaterial) and have conducted experiments to determine the effects of this material on the reconstruction of periodontal tissue. Implantations were performed using a HAP-atelocollagen complex, TCP-atelocollagen complex, HAP and TCP at three-wall bone defect sites in experimentally-induced periodontitis in dogs. A control group without the implants was included in the study. Histopathological observations were conducted 2, 4 and 12 weeks after surgery. Compared with the control group, the groups implanted with the complex displayed enhanced maintenance and stability of granules, suppression of epithelial downgrowth, and acceleration of new bone and cementum formation. These results indicate that the implant method using an atelocollagen-coated artificial bone implant material would be useful for periodontal surgical treatment, eliminating some of the disadvantages of conventional implant methods.

  19. A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality.

    Science.gov (United States)

    Hoerth, Rebecca M; Katunar, María R; Gomez Sanchez, Andrea; Orellano, Juan C; Ceré, Silvia M; Wagermaier, Wolfgang; Ballarre, Josefina

    2014-02-01

    Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments.

  20. 人工骨材料修复骨缺损:多种复合后的生物学与力学特征%Artificial bone materials for bone defect repair:biomechanical characteristics of multiple composites

    Institute of Scientific and Technical Information of China (English)

    杨毅; 毕鑫; 李多玉; 唐一萍; 李彪

    2014-01-01

    materials worldwide in recent years. METHODS:A computer-based search was performed in China Journal Ful-Text Database, PubMed database, China Biology Medicine Database and FMJS database to retrieve the papers concerning artificial bone materials published from 2007 to 2013. The keywords were “artificial bone, material, bone defect, bone graft” in Chinese and English. RESULTS AND CONCLUSION:The current commonly used artificial bone materials are natural polymer materials, synthetic polymer, inorganic material and nanometer material. The ideal bone graft substitutes should have the folowing conditions: good biocompatibility; local formation of acidic biological environment, good for the ingrowth of blood vessels and osteoblasts; complete biodegradation; osteogenesis, bone conduction and bone induction. Biological fibrin glue has good degradation and histocompatibility that can be shaped, but its strength is poor. The future research direction mainly focuses to reinforce its strength. Synthetic and inorganic materials have good strength and support role, but the histocompatibility is poor, for which, it is very important to improve the histocompatibility. Nanometer material is a suitable artificial bone material. Currently used artificial bone materials in bone tissue engineering research al have their respective advantages and disadvantages. They cannot satisfy the requirements of ideal bone tissue engineering extracelular matrix materials at the same time, and they have differences in the biological peculiarity and mechanical peculiarity with natural bone. Therefore, compositing the various types of materials with structure and function modification is the direction of developing ideal bone defect repair materials.

  1. Antler stiffness in moose (Alces alces): correlated evolution of bone function and material properties?

    Science.gov (United States)

    Blob, Richard W; Snelgrove, Jason M

    2006-09-01

    The material properties of bone can vary considerably among skeletal elements from different parts of the body that serve different functions. However, functional demands placed on a specific type of skeletal element also can vary at a variety of scales, such as between different parts of the element, among individuals of a species, and across species. Variation in bone material properties might be correlated with differing functional demands at any of these scales. In this study we performed three-point bending tests on bone specimens extracted from antlers of moose (Alces alces) to test for three types of variation in bone material stiffness (Young's modulus): within the antler structure, between populations of moose, and between moose and other deer species. Because superficial portions of the antler are exposed to greater bending stress and strain than deeper portions, and because the antler beam (the basal shaft that attaches to the skull) is subjected to greater bending moments than more distal parts of the antler, we predicted that superficial bone and bone from the beam would be stiffer than bone from other parts of the antler. Instead, we identified no significant differences in these comparisons. There were also no significant differences in antler stiffness between moose from Michigan and the Yukon, even though the rapid growth required of antlers from northern latitudes like the Yukon has the potential to compromise bone material properties. However, moose have significantly stiffer antlers (11.6 +/- 0.45 GPa, mean +/- SE) than any other deer in the odocoileine lineage. Moreover, phylogenetic reconstructions of the evolution of antler stiffness in deer indicate a strong potential that high antler stiffness is a derived feature of moose. The unusual palmate shape of moose antlers likely subjects their antler beams to higher bending moments than found in other odocoileines, a factor that may have contributed to the evolutionary divergence of moose antler

  2. Comparison about the bone material examination of JIS and ISO; Honezai shiken ni kansuru JIS to ISO no hikaku

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Sumie.; Yanagi, Kei.; Shimura, Akiharu.; Murohoshi, Shiori. [Japan Testing Center for Construction Materials, Tokyo (Japan)

    1998-12-01

    There are various things in slug bone material and so on manufactured from the macadam, crumble sand. Which crushed rock including gravel, sand to produce in the nature and which was manufactured, and a lightweight bone material and the industry by-product with the bone material used for the concrete. It is necessary with a bone material to grasp the nature of the bone material itself properly to occupy about 70% of the capacity in the concrete and to manufacture the good concrete of the quality from the influence that influence to the various concrete materiality that quality being big. When the quality of a bone material to use for the concrete is confirmed, an examination is being done in accordance with the way of examining it established as the Japanese industry standard in our country. (NEDO)

  3. Surface coatings for improvement of bone cell materials and antimicrobial activities of Ti implants.

    Science.gov (United States)

    Das, Kakoli; Bose, Susmita; Bandyopadhyay, Amit; Karandikar, Balu; Gibbins, Bruce L

    2008-11-01

    Ti surface was modified to simultaneously improve bone cell materials and antimicrobial activities. Titanium surface was first anodized in sodium fluoride and sulfuric acid electrolytic solution to form titania nanotube on the surface to improve the biocompatibility of the surface. Silver was electrodeposited on the titania nanotube surface at 5 V. Silver added titania nanotube surface was tested for compatibility with bone-cell materials interactions using human osteoblast bone cells. The antibacterial effect was studied using Pseudomonas aeruginosa. Our results show that silver-treated titania nanotube surface may provide antibacterial properties to prevent implants against postoperative infections without interference to the attachment and proliferation of bone tissue on titanium, which is commonly used in dental and orthopedic surgical procedures.

  4. Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones

    Energy Technology Data Exchange (ETDEWEB)

    Piccirillo, C.; Silva, M.F. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pullar, R.C. [Dept. Engenharia de Materiais e Ceramica/CICECO, Universidade de Aveiro, Aveiro (Portugal); Braga da Cruz, I. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Jorge, R. [WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pintado, M.M.E. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Castro, P.M.L., E-mail: plcastro@porto.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal)

    2013-01-01

    Apatite- and tricalcium phosphate-based materials were produced from codfish bones, thus converting a waste by-product from the food industry into high added-valued compounds. The bones were annealed at temperatures between 900 and 1200 Degree-Sign C, giving a biphasic material of hydroxyapatite and tricalcium phosphate (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and {beta}-Ca(PO{sub 4}){sub 3}) with a molar proportion of 75:25, a material widely used in biomedical implants. The treatment of the bones in solution prior to their annealing changed the composition of the material. Single phase hydroxyapatite, chlorapatite (Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}) and fluorapatite (Ca{sub 10}(PO{sub 4}){sub 6}F{sub 2}) were obtained using CaCl{sub 2} and NaF solutions, respectively. The samples were analysed by several techniques (X-ray diffraction, infrared spectroscopy, scanning electron microscopy and differential thermal/thermogravimetric analysis) and by elemental analyses, to have a more complete understanding of the conversion process. Such compositional modifications have never been performed before for these materials of natural origin to tailor the relative concentrations of elements. This paper shows the great potential for the conversion of this by-product into highly valuable compounds for biomedical applications, using a simple and effective valorisation process. - Highlights: Black-Right-Pointing-Pointer Apatite and calcium phosphate compounds extraction from cod fish bones Black-Right-Pointing-Pointer Bone calcination: biphasic material hydroxyapatite-calcium phosphate production Black-Right-Pointing-Pointer Bone pre-treatments in solution change the material composition. Black-Right-Pointing-Pointer Single phase materials (hydroxy-, chloro- or fluoroapatite) are obtained. Black-Right-Pointing-Pointer Concentration of other elements (Na, F, Cl) suitable for biomedical applications.

  5. Comparison and preparation of multilayered polylactic acid fabric strengthen calcium phosphate-based bone substitutes for orthopedic applications.

    Science.gov (United States)

    Chen, Wen-Cheng; Ko, Chia-Ling; Yang, Jia-Kai; Wu, Hui-Yu; Lin, Jia-Horng

    2016-03-01

    An attempt to maintain the three-dimensional space into restorative sites through the conveniently pack porous fillers are general used strategy. Advancement in the manufacturing protective shells in the scaffolds, which would be filled with brittle ceramic grafts for the development of highly connective pores provides the approach to solve crack problem for generating the tissues. Therefore, multilayered braided and alkalized poly(lactic acid) (PLA) composites with calcium phosphate bone cement (CPC) were synthesized and compared. The PLA/CPC composites were divided into various groups according to a series of heat-treatment temperatures (100-190 °C) and periods (1-3 h) and then characterized. The effects of 24-h immersion on the strength decay resistance of the samples were compared. Results showed that the residual oil capped on the surfaces of alkalized PLA braid was removed, and the structure was unaltered. However, the reduced tensile stress of alkalized PLA braids was due to ester-group formation by hydrolysis. Mechanical test results of PLA/CPC composites showed that the strength significantly increased after heat treatment, except when the heating temperature was higher than the PLA melting point at approximately 160-170 °C. The degree of PLA after recrystallization became higher than that of unheated composites, thereby leading to reduced strength and toughness of the specimen. Braiding fibers of biodegradable PLA reinforced and toughened the structure particularly of the extra-brittle material of thin-sheet CPC after implantation.

  6. A non-linear homogeneous model for bone-like materials under compressive load.

    Science.gov (United States)

    Mengoni, M; Voide, R; de Bien, C; Freichels, H; Jérôme, C; Léonard, A; Toye, D; Müller, R; van Lenthe, G H; Ponthot, J P

    2012-02-01

    Finite element (FE) models accurately compute the mechanical response of bone and bone-like materials when the models include their detailed microstructure. In order to simulate non-linear behavior, which currently is only feasible at the expense of extremely high computational costs, coarser models can be used if the local morphology has been linked to the apparent mechanical behavior. The aim of this paper is to implement and validate such a constitutive law. This law is able to capture the non-linear structural behavior of bone-like materials through the use of fabric tensors. It also allows for irreversible strains using an elastoplastic material model incorporating hardening. These features are expressed in a constitutive law based on the anisotropic continuum damage theory coupled with isotropic elastoplasticity in a finite strain framework. This material model was implemented into metafor (LTAS-MNNL, University of Liège, Belgium), a non-linear FE software. The implementation was validated against experimental data of cylindrical samples subjected to compression. Three materials with bone-like microstructure were tested: aluminum foams of variable density (ERG, Oakland, CA, USA), polylactic acid foam (CERM, University of Liège, Liège, Belgium), and cancellous bone tissue of a deer antler (Faculty of Veterinary Medicine, University of Liège, Liège, Belgium).

  7. Effects of Materials of Cementless Femoral Stem on the Functional Adaptation of Bone

    Institute of Scientific and Technical Information of China (English)

    He Gong; Wei Wu; Juan Fang; Xin Dong; Meisheng Zhao; Tongtong Guo

    2012-01-01

    The objective of this paper is to identify the effects of materials of cementless femoral stem on the functional adaptive behaviors of bone.The remodeling behaviors of a two-dimensional simplified model of cementless hip prosthesis with stiff stem,flexible 'iso-elastic' stem,one-dimensional Functionally Graded Material (FGM) stem and two-dimensional FGM stem for the period of four years after prosthesis replacement were quantified by incorporating the bone remodeling algorithm with finite element analysis.The distributions of bone density,von Mises stress,and interface shear stress were obtained.The results show that two-dimensional FGM stem may produce more mechanical stimuli and more uniform interface shear stress compared with the stems made of other materials,thus the host bone is well preserved.Accordingly,the two-dimensional FGM stem is an appropriate femoral implant from a biomechanical point of view.The numerical simulation in this paper can provide a quantitative computational paradigm for the changes of bone morphology caused by implants,which can help to improve the design of implant to reduce stress shielding and the risk of bone-prosthesis interface failure.

  8. Osteogenic protein-1 increases the fixation of implants grafted with morcellised bone allograft and ProOsteon bone substitute: an experimental study in dogs

    DEFF Research Database (Denmark)

    Baad-Hansen, Thomas Einer; Overgaard, S; Lind, M;

    2007-01-01

    (ProOsteon) would improve the incorporation of bone and implant fixation. We also compared the response to using ProOsteon alone against bone allograft used in isolation. We implanted two non-weight-bearing hydroxyapatite-coated implants into each proximal humerus of six dogs, with each implant...... surrounded by a concentric 3 mm gap. These gaps were randomly allocated to four different procedures in each dog: 1) bone allograft used on its own; 2) ProOsteon used on its own; 3) allograft and ProOsteon used together; or 4) allograft and ProOsteon with the addition of osteogenic protein-1. After three...

  9. [Mandibular bone tissue regeneration after the introduction of the implantation system performed on the basis of carbon composite material].

    Science.gov (United States)

    Chetvertnykh, V A; Loginova, N P; Astashina, N B; Rogozhnikov, G I; Rapekta, S I

    2013-01-01

    The purpose of this study was to investigate the processes of regeneration of bone tissue after the introduction of new implant systems. In the experiment, performed on 10 male pigs of Landras breed aged 50-55 days and weighing 17-18.5 kg, the time course of histological changes was studied in the area of mandibular regeneration after the formation of tissue defect and the introduction of the implant of a proposed construction. Morphological analysis of the experimental results 90, 180 and 270 days after the operation demonstrated the process of reparative regeneration of damaged bone along implant-bone block boundaries. Bone repair proceeded through the stage of formation of the woven bone with its progressive substitution by the lamellar bone, with the maintenance of the shape, size and symmetry of the damaged organ.

  10. Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep

    DEFF Research Database (Denmark)

    Ding, Ming; Andreasen, Christina Møller; Dencker, Mads L.;

    2015-01-01

    hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could...... implant were not significantly different among the four groups. The ABM/P-15 group had similar shear mechanical properties on implant fixation as the allograft group. Adding HA/βTCP-PDLLA to ABM/P-15 did not significantly change these parameters. This study revealed that ABM/P-15 had significantly bone...

  11. Comparison of platelet rich plasma and synthetic graft material for bone regeneration after third molar extraction

    Science.gov (United States)

    Nathani, Dipesh B.; Sequeira, Joyce; Rao, B. H. Sripathi

    2015-01-01

    Aims: To compare the efficacy of Platelet rich plasma and synthetic graft material for bone regeneration after bilateral third molar extraction. Material and Methods: This study was conducted in 10 patients visiting the outpatient department of Oral & Maxillofacial Surgery, Yenepoya Dental College & Hospital. Patients requiring extraction of bilateral mandibular third molars were taken for the study. Following extraction, PRP (Platelet Rich Plasma) was placed in one extraction socket and synthetic graft material in form granules [combination of Hydroxyapatite (HA) and Bioactive glass (BG)] in another extraction socket. The patients were assessed for postoperative pain and soft tissue healing. Radiological assessment of the extraction site was done at 8, 12 and 16 weeks interval to compare the change in bone density in both the sockets. Results: Pain was less on PRP site when compared to HA site. Soft tissue evaluation done using gingival healing index given by Landry et al showed better healing on PRP site when compared to HA site. The evaluation of bone density by radiological assessment showed the grey level values calculated at 4 months at the PRP site were comparatively higher than HA site. Conclusion: The study showed that the platelet rich plasma is a better graft material than synthetic graft material in terms of soft tissue and bone healing. However a more elaborate study with a larger number of clinical cases is very much essential to be more conclusive regarding the efficacy of both the materials. PMID:26981473

  12. A new Fe–Mn–Si alloplastic biomaterial as bone grafting material: In vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Fântânariu, Mircea, E-mail: mfantanariu@uaiasi.ro [“Ion Ionescu de la Brad” University of Agricultural Sciences and Veterinary Medicine, Faculty of Veterinary Medicine, Str. Aleea M. Sadoveanu, no. 8, 700489, Iasi (Romania); Trincă, Lucia Carmen, E-mail: lctrinca@uaiasi.ro [“Ion Ionescu de la Brad” University of Agricultural Sciences and Veterinary Medicine, Faculty of Horticulture, Str. Aleea M. Sadoveanu, no. 3, 700490, Iasi (Romania); Solcan, Carmen, E-mail: csolcan@yahoo.com [“Ion Ionescu de la Brad” University of Agricultural Sciences and Veterinary Medicine, Faculty of Veterinary Medicine, Str. Aleea M. Sadoveanu, no. 8, 700489, Iasi (Romania); Trofin, Alina, E-mail: aetrofin@yahoo.com [“Ion Ionescu de la Brad” University of Agricultural Sciences and Veterinary Medicine, Faculty of Horticulture, Str. Aleea M. Sadoveanu, no. 3, 700490, Iasi (Romania); Strungaru, Ştefan, E-mail: strungaru_stefan@yahoo.com [“Alexandru Ioan Cuza” University, Faculty of Biology, Bulevardul Carol I, Nr.11, 700506, Iasi (Romania); Şindilar, Eusebiu Viorel, E-mail: esindilar@uaiasi.ro [“Ion Ionescu de la Brad” University of Agricultural Sciences and Veterinary Medicine, Faculty of Veterinary Medicine, Str. Aleea M. Sadoveanu, no. 8, 700489, Iasi (Romania); Plăvan, Gabriel, E-mail: gabriel.plavan@uaic.ro [“Alexandru Ioan Cuza” University, Faculty of Biology, Bulevardul Carol I, Nr.11, 700506, Iasi (Romania); and others

    2015-10-15

    Highlights: • A Fe–Mn–Si alloy was obtained as alloplastic graft material for bone implants. • Fe–Mn–Si alloy degradation rate was preliminary evaluate with SEM and EDAX techniques. • Biochemical, histological, RX and CT investigations were done in rats with subcutaneous and tibiae implants. • Fe–Mn–Si alloy assured an ideal compromise between degradation and mechanical integrity during bone regeneration. - Abstract: Designing substrates having suitable mechanical properties and targeted degradation behavior is the key's development of bio-materials for medical application. In orthopedics, graft material may be used to fill bony defects or to promote bone formation in osseous defects created by trauma or surgical intervention. Incorporation of Si may increase the bioactivity of implant locally, both by enhancing interactions at the graft–host interface and by having a potential endocrine like effect on osteoblasts. A Fe–Mn–Si alloy was obtained as alloplastic graft materials for bone implants that need long recovery time period. The surface morphology of the resulted specimens was investigated using scanning electrons microscopy (VegaTescan LMH II, SE detector, 30 kV), X-ray diffractions (X’Pert equipment) or X-ray dispersive energy analyze (Bruker EDS equipment). This study objective was to evaluate in vivo the mechanisms of degradation and the effects of its implantation over the main metabolic organs. Biochemical, histological, plain X radiography and computed tomography investigations showed good compatibility of the subcutaneous implants in the rat organism. The implantation of the Fe–Mn–Si alloy, in critical size bone (tibiae) defect rat model, did not induced adverse biological reactions and provided temporary mechanical support to the affected bone area. The biodegradation products were hydroxides layers which adhered to the substrate surface. Fe–Mn–Si alloy assured the mechanical integrity in rat tibiae defects

  13. Global carbon benefits of material substitution in passenger cars until 2050 and the impact on the steel and aluminum industries.

    Science.gov (United States)

    Modaresi, Roja; Pauliuk, Stefan; Løvik, Amund N; Müller, Daniel B

    2014-09-16

    Light-weighting of passenger cars using high-strength steel or aluminum is a common emissions mitigation strategy. We provide a first estimate of the global impact of light-weighting by material substitution on GHG emissions from passenger cars and the steel and aluminum industries until 2050. We develop a dynamic stock model of the global car fleet and combine it with a dynamic MFA of the associated steel, aluminum, and energy supply industries. We propose four scenarios for substitution of conventional steel with high-strength steel and aluminum at different rates over the period 2010-2050. We show that light-weighting of passenger cars can become a "gigaton solution": Between 2010 and 2050, persistent light-weighting of passenger cars can, under optimal conditions, lead to cumulative GHG emissions savings of 9-18 gigatons CO2-eq compared to development business-as-usual. Annual savings can be up to 1 gigaton per year. After 2030, enhanced material recycling can lead to further reductions: closed-loop metal recycling in the automotive sector may reduce cumulative emissions by another 4-6 gigatons CO2-eq. The effectiveness of emissions mitigation by material substitution significantly depends on how the recycling system evolves. At present, policies focusing on tailpipe emissions and life cycle assessments of individual cars do not consider this important effect.

  14. Effects of gamma irradiation on the initial mechanical and material properties of goat bone-patellar tendon-bone allografts

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, M.J.; Butler, D.L.; Grood, E.S.; Bylski-Austrow, D.I.; Levy, M.S.; Noyes, F.R. (Univ. of Cincinnati, OH (USA))

    1991-03-01

    The effects of {sup 60}Co gamma irradiation on the initial mechanical properties of the composite bone-patellar tendon-bone unit (CU) and the tendon midsubstance (TM) were studied. Frozen specimens were exposed to either 2 or 3 Mrad of gamma irradiation. Paired frozen specimens served as intraanimal controls. Treatment effects on the CU were assessed using four mechanical parameters. Effects on the TM were assessed using four material parameters measured using an optical surface-strain analysis system. The maximum force and strain energy to maximum force of the composite unit were significantly reduced 27% and 40%, respectively, after 3 Mrad of irradiation (p less than .05). Mechanical properties of the CU were not significantly altered, however, following 2 Mrad of irradiation. Based on individual paired contrasts between treatment and control, significant differences were also found in the material properties of the tendon midsubstance. The maximum stress, maximum strain, and strain energy density to maximum stress were significantly reduced following 3 Mrad, but not 2 Mrad, of irradiation. The results provide important time zero material property data, which will be useful for later anterior cruciate ligament reconstruction studies using irradiated allograft patellar tendons in the goat model and other animal models as well.

  15. Theoretical Study on the Rational Design of Cyano-Substituted P3HT Materials for OSCs

    DEFF Research Database (Denmark)

    Qiu, Meng; Brandt, Rasmus Guldbæk; Niu, Yingli

    2015-01-01

    Calculations have been made regarding the strong electron-withdrawing cyano (-CN) group, which was introduced onto the backbone of poly(3-hexylthiophene) (P3HT), as an effective way to improve the parameters essential for the photovoltaic performance of organic solar cells (OSCs). The substitution...... effect on the optical and photovoltaic properties of various CN-substituted P3HT are comprehensively investigated by means of density functional theory and molecular dynamics simulation. The results of theoretical modeling indicate that the direct introduction of strong electron-withdrawing group -CN...

  16. Magnetic hydroxyapatite bone substitutes to enhance tissue regeneration: evaluation in vitro using osteoblast-like cells and in vivo in a bone defect.

    Directory of Open Access Journals (Sweden)

    Silvia Panseri

    Full Text Available In case of degenerative disease or lesion, bone tissue replacement and regeneration is an important clinical goal. In particular, nowadays, critical size defects rely on the engineering of scaffolds that are 3D structural supports, allowing cellular infiltration and subsequent integration with the native tissue. Several ceramic hydroxyapatite (HA scaffolds with high porosity and good osteointegration have been developed in the past few decades but they have not solved completely the problems related to bone defects. In the present study we have developed a novel porous ceramic composite made of HA that incorporates magnetite at three different ratios: HA/Mgn 95/5, HA/Mgn 90/10 and HA/Mgn 50/50. The scaffolds, consolidated by sintering at high temperature in a controlled atmosphere, have been analysed in vitro using human osteoblast-like cells. Results indicate high biocompatibility, similar to a commercially available HA bone graft, with no negative effects arising from the presence of magnetite or by the use of a static magnetic field. HA/Mgn 90/10 was shown to enhance cell proliferation at the early stage. Moreover, it has been implanted in vivo in a critical size lesion of the rabbit condyle and a good level of histocompatibility was observed. Such results identify this scaffold as particularly relevant for bone tissue regeneration and open new perspectives for the application of a magnetic field in a clinical setting of bone replacement, either for magnetic scaffold fixation or magnetic drug delivery.

  17. Repairing rabbit radial defects by combining bone marrow stroma stem cells with bone scaffold material comprising a core-cladding structure.

    Science.gov (United States)

    Wu, H; Liu, G H; Wu, Q; Yu, B

    2015-10-05

    We prepared a bone scaffold material comprising a PLGA/β-TCP core and a Type I collagen cladding, and recombined it with bone marrow stroma stem cells (BMSCs) to evaluate its potential for use in bone tissue engineering by in vivo and in vitro experiments. PLGA/β-TCP without a cladding was used for comparison. The adherence rate of the BMSCs to the scaffold was determined by cell counting. Cell proliferation rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The osteogenic capability was evaluated by alkaline phosphatase activity. The scaffold materials were recombined with the BMSCs and implanted into a large segmental rabbit radial defect model to evaluate defect repair. Osteogenesis was assessed in the scaffold materials by histological and double immunofluorescence labeling, etc. The adherence number, proliferation number, and alkaline phosphatase expression of the cells on the bone scaffold material with core-cladding structure were significantly higher than the corresponding values in the PLGA/β-TCP composite scaffold material (P cladding structure completely degraded at the bone defect site and bone formation was completed. The rabbit large sentimental radial defect was successfully repaired. The degradation and osteogenesis rates matched well. The bone scaffold with core-cladding structure exhibited better osteogenic activity and capacity to repair a large segmental bone defect compared to the PLGA/β-TCP composite scaffold. The bone scaffold with core-cladding structure has excellent physical properties and biocompatibility. It is an ideal scaffold material for bone tissue engineering.

  18. Selective laser melting-produced porous titanium scaffolds regenerate bone in critical size cortical bone defects

    NARCIS (Netherlands)

    J. van der Stok (Johan); O.P. van der Jagt (Olav); S. Amin Yavari (Saber); M.F.P. de Haas (Mirthe); J.H. Waarsing (Jan); H. Jahr (Holger); E.M.M. van Lieshout (Esther); P. Patka (Peter); J.A.N. Verhaar (Jan); A.A. Zadpoor (Amir Abbas); H.H. Weinans (Harrie)

    2013-01-01

    textabstractPorous titanium scaffolds have good mechanical properties that make them an interesting bone substitute material for large bone defects. These scaffolds can be produced with selective laser melting, which has the advantage of tailoring the structure's architecture. Reducing the strut siz

  19. Biomechanical properties of an advanced new carbon/flax/epoxy composite material for bone plate applications.

    Science.gov (United States)

    Bagheri, Zahra S; El Sawi, Ihab; Schemitsch, Emil H; Zdero, Rad; Bougherara, Habiba

    2013-04-01

    This work is part of an ongoing program to develop a new carbon fiber/flax/epoxy (CF/flax/epoxy) hybrid composite material for use as an orthopaedic long bone fracture plate, instead of a metal plate. The purpose of this study was to evaluate the mechanical properties of this new novel composite material. The composite material had a "sandwich structure", in which two thin sheets of CF/epoxy were attached to each outer surface of the flax/epoxy core, which resulted in a unique structure compared to other composite plates for bone plate applications. Mechanical properties were determined using tension, three-point bending, and Rockwell hardness tests. Also, scanning electron microscopy (SEM) was used to characterize the failure mechanism of specimens in tension and three-point bending tests. The results of mechanical tests revealed a considerably high ultimate strength in both tension (399.8MPa) and flexural loading (510.6MPa), with a higher elastic modulus in bending tests (57.4GPa) compared to tension tests (41.7GPa). The composite material experienced brittle catastrophic failure in both tension and bending tests. The SEM images, consistent with brittle failure, showed mostly fiber breakage and fiber pull-out at the fractured surfaces with perfect bonding at carbon fibers and flax plies. Compared to clinically-used orthopaedic metal plates, current CF/flax/epoxy results were closer to human cortical bone, making the material a potential candidate for use in long bone fracture fixation.

  20. The effect of water, various incorporations and substitutions on physical and chemical properties of bioapatite and mechanical properties of bone tissue

    Directory of Open Access Journals (Sweden)

    A. S. Avrunin

    2015-01-01

    Full Text Available Basing on scientific publications and original research the authors specified the effect of incorporation and adsorption of different ions and water molecules on physical, chemical and mechanical properties of bioapatite and determined new directions for investigations of intercrystallite interactions in nanoscale. Inner structure of the apatite crystallites more adaptable to chemical substitutions in comparison with other minerals controls their important characteristics such as a size, solubility, hardness, fragility, formability and thermal stability. The water molecules incorporated in crystallites and adsorbed on their surfaces stabilize them. In case the distances between crystallites become shorter than 10 nm the water molecules adsorbed on their surface play dominant role in bonding between the crystallites. This bond determines the main mechanical properties of bones. We bring forward a suggestion that theoretical model developed on the basis of near edge X-ray spectroscopic studies of bones using the contemporary high brilliant sources of X-ray radiation (synchrotrons and X-ray free electrons lasers will allow to receive new quantitative data on local electronic and atomic structure (coordination numbers, ionic charges, interatomic distances interatomic and intercrystallite forces of nanoelements in osseous tissue. The investigation results must bring to construction of new morphologically correct model providing deeper understanding of processes occurring in mineral matrix and mechanical properties of bones.

  1. Elastic moduli of untreated, demineralized and deproteinized cortical bone: validation of a theoretical model of bone as an interpenetrating composite material.

    Science.gov (United States)

    Hamed, E; Novitskaya, E; Li, J; Chen, P-Y; Jasiuk, I; McKittrick, J

    2012-03-01

    A theoretical experimentally based multi-scale model of the elastic response of cortical bone is presented. It portrays the hierarchical structure of bone as a composite with interpenetrating biopolymers (collagen and non-collagenous proteins) and minerals (hydroxyapatite), together with void spaces (porosity). The model involves a bottom-up approach and employs micromechanics and classical lamination theories of composite materials. Experiments on cortical bone samples from bovine femur include completely demineralized and deproteinized bones as well as untreated bone samples. Porosity and microstructure are characterized using optical and scanning electron microscopy, and micro-computed tomography. Compression testing is used to measure longitudinal and transverse elastic moduli of all three bone types. The characterization of structure and properties of these three bone states provides a deeper understanding of the contributions of the individual components of bone to its elastic response and allows fine tuning of modeling assumptions. Very good agreement is found between theoretical modeling and compression testing results, confirming the validity of the interpretation of bone as an interpenetrating composite material.

  2. Pneumatization of the Temporal Bones in a Greenlandic Inuit Anthropological Material

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N

    1991-01-01

    The degree of pneumatization of the temporal bones correlates with exposure during childhood and adolescence to infectious middle ear diseases (IMED), both acute and chronic. The pneumatized area as seen on cranial X-rays can be measured. This was applied to an anthropological material in order...

  3. Influence of Material Properties on Rate of Resorption of Two Bone Graft Materials after Sinus Lift Using Radiographic Assessment

    Directory of Open Access Journals (Sweden)

    Fawzi Riachi

    2012-01-01

    Full Text Available Purpose. The aim of this study was to investigate the influence of chemical and physical properties of two graft materials on the rate of resorption. Materials and Methods. Direct sinus graft procedure was performed on 22 patients intended for implant placement. Two types of graft materials were used (Bio-Oss and Cerabone and after 8 months healing time the implants were inserted. Radiographic assessment was performed over the period of four years. Particle size, rate of calcium release, and size and type of crystal structure of each graft were evaluated. Results. The average particle size of Bio-Oss (1 mm was much smaller compared to Cerabone (2.7 mm. The amount of calcium release due to dissolution of material in water was much higher for Bio-oss compared to Cerabone. X-ray image analysis revealed that Bio-Oss demonstrated significantly higher volumetric loss (33.4 ± 3.1% of initial graft size compared to Cerabone (23.4 ± 3.6%. The greatest amount of vertical loss of graft material volume was observed after one year of surgery. Conclusion. The chemical and physical properties of bone graft material significantly influence resorption rate of bone graft materials used for sinus augmentation.

  4. A biocompatible hybrid material with simultaneous calcium and strontium release capability for bone tissue repair

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, J. Carlos [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Wacha, András [Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2, Budapest 1117 (Hungary); Gomes, Pedro S. [Laboratory for Bone Metabolism and Regeneration, Faculdade de Medicina Dentária, Universidade do Porto (Portugal); Alves, Luís C. [C2TN, Instituto Superior Técnico, Universidade de Lisboa, E.N.10, 2695-066 Bobadela LRS (Portugal); Fernandes, M. Helena Vaz [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Salvado, Isabel M. Miranda, E-mail: isabelmsalvado@ua.pt [CICECO — Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Fernandes, M. Helena R. [Laboratory for Bone Metabolism and Regeneration, Faculdade de Medicina Dentária, Universidade do Porto (Portugal)

    2016-05-01

    The increasing interest in the effect of strontium in bone tissue repair has promoted the development of bioactive materials with strontium release capability. According to literature, hybrid materials based on the system PDMS–SiO{sub 2} have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS–SiO{sub 2}–CaO–SrO, was prepared with the incorporation of 0.05 mol of titanium per mol of SiO{sub 2}. Calcium and strontium were added using the respective acetates as sources, following a sol–gel technique previously developed by the present authors. The obtained samples were characterized by FT-IR, solid-state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studies were performed by immersion of the samples in Kokubo's SBF for different periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed samples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity. - Highlights: • A hybrid PDMS–SiO{sub 2}–CaO–SrO material was prepared with the incorporation of Ti. • Sr was released in concentrations suitable for the induction of bone tissue repair. • The material demonstrated to be cytocompatible when tested with osteoblastic cells.

  5. Materials and prognostic factors of bone regeneration in periapical surgery: A systematic review

    OpenAIRE

    Sánchez Torres, Alba; Sánchez Garcés, María Angeles; Gay Escoda, Cosme

    2014-01-01

    Objectives: Analyse the effectiveness of different materials and techniques used in guided tissue regeneration (GTR) applied in periapical surgery, comparing the success rate obtained in 4-wall defects and in through-and-through bone lesions as well as to establish prognostic factors. Material and Methods: A Cochrane, PubMed-MEDLINE and Scopus database search (October 2012 to March 2013) was conducted with the search terms “periapical surgery”, “surgical endodontic treatment”, “guided tissue ...

  6. Fresh-frozen bone: case series of a new grafting material for sinus lift and immediate implants.

    LENUS (Irish Health Repository)

    Viscioni, A

    2010-08-01

    Although autologous bone is considered to be the gold standard grafting material, it needs to be harvested from patients, a process that can be off-putting and can lead to donor site morbidity. For this reason, homologous fresh-frozen bone (FFB) was used in the current study as an alternative graft material.

  7. Bone Regeneration after Treatment with Covering Materials Composed of Flax Fibers and Biodegradable Plastics: A Histological Study in Rats

    Science.gov (United States)

    Gedrange, Tomasz

    2016-01-01

    The aim of this study was to examine the osteogenic potential of new flax covering materials. Bone defects were created on the skull of forty rats. Materials of pure PLA and PCL and their composites with flax fibers, genetically modified producing PHB (PLA-transgen, PCL-transgen) and unmodified (PLA-wt, PCL-wt), were inserted. The skulls were harvested after four weeks and subjected to histological examination. The percentage of bone regeneration by using PLA was less pronounced than after usage of pure PCL in comparison with controls. After treatment with PCL-transgen, a large amount of new formed bone could be found. In contrast, PCL-wt decreased significantly the bone regeneration, compared to the other tested groups. The bone covers made of pure PLA had substantially less influence on bone regeneration and the bone healing proceeded with a lot of connective tissue, whereas PLA-transgen and PLA-wt showed nearly comparable amount of new formed bone. Regarding the histological data, the hypothesis could be proposed that PCL and its composites have contributed to a higher quantity of the regenerated bone, compared to PLA. The histological studies showed comparable bone regeneration processes after treatment with tested covering materials, as well as in the untreated bone lesions. PMID:27597965

  8. Bone Regeneration after Treatment with Covering Materials Composed of Flax Fibers and Biodegradable Plastics: A Histological Study in Rats.

    Science.gov (United States)

    Gredes, Tomasz; Kunath, Franziska; Gedrange, Tomasz; Kunert-Keil, Christiane

    2016-01-01

    The aim of this study was to examine the osteogenic potential of new flax covering materials. Bone defects were created on the skull of forty rats. Materials of pure PLA and PCL and their composites with flax fibers, genetically modified producing PHB (PLA-transgen, PCL-transgen) and unmodified (PLA-wt, PCL-wt), were inserted. The skulls were harvested after four weeks and subjected to histological examination. The percentage of bone regeneration by using PLA was less pronounced than after usage of pure PCL in comparison with controls. After treatment with PCL-transgen, a large amount of new formed bone could be found. In contrast, PCL-wt decreased significantly the bone regeneration, compared to the other tested groups. The bone covers made of pure PLA had substantially less influence on bone regeneration and the bone healing proceeded with a lot of connective tissue, whereas PLA-transgen and PLA-wt showed nearly comparable amount of new formed bone. Regarding the histological data, the hypothesis could be proposed that PCL and its composites have contributed to a higher quantity of the regenerated bone, compared to PLA. The histological studies showed comparable bone regeneration processes after treatment with tested covering materials, as well as in the untreated bone lesions.

  9. Asymmetrically substituted 5,5 `-bistriazoles - nitrogen-rich materials with various energetic functionalities

    OpenAIRE

    Dippold, Alexander A.; Klapötke, Thomas M.; Oswald, Michaela

    2013-01-01

    In this contribution the synthesis and full structural and spectroscopic characterization of three asymmetrically substituted bis-1,2,4-triazoles, along with different energetic moieties like amino, nitro, nitrimino and azido moieties, is presented. Additionally, selected nitrogen-rich ionic derivatives have been prepared and characterized. This comparative study on the influence of these energetic moieties on structural and energetic properties constitutes a complete characterization includi...

  10. Histological Study on a Novel Bone Graft Substitute: Human Derived Tooth-Hydroxyapatite Compared With Coralline Hydroxyapatite

    Science.gov (United States)

    2007-11-02

    HCl, Eczacýbaþý, Ýstanbul, Turkey). After anesthesia the tibial section of the right leg was shaved and disinfected. Under sterile surgical...conditions after incising the skin, the muscles and periost were dissected. The spongious bone medially at the proximal metaphysis of the tibia was

  11. Biomineralization of Engineered Spider Silk Protein-Based Composite Materials for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    John G. Hardy

    2016-07-01

    Full Text Available Materials based on biodegradable polyesters, such as poly(butylene terephthalate (PBT or poly(butylene terephthalate-co-poly(alkylene glycol terephthalate (PBTAT, have potential application as pro-regenerative scaffolds for bone tissue engineering. Herein, the preparation of films composed of PBT or PBTAT and an engineered spider silk protein, (eADF4(C16, that displays multiple carboxylic acid moieties capable of binding calcium ions and facilitating their biomineralization with calcium carbonate or calcium phosphate is reported. Human mesenchymal stem cells cultured on films mineralized with calcium phosphate show enhanced levels of alkaline phosphatase activity suggesting that such composites have potential use for bone tissue engineering.

  12. A novel composite material specifically developed for ultrasound bone phantoms: cortical, trabecular and skull.

    Science.gov (United States)

    Wydra, A; Maev, R Gr

    2013-11-21

    In the various stages of developing diagnostic and therapeutic equipment, the use of phantoms can play a very important role in improving the process, help in implementation, testing and calibrations. Phantoms are especially useful in developing new applications and training new doctors in medical schools. However, devices that use different physical factors, such as MRI, Ultrasound, CT Scan, etc will require the phantom to be made of different physical properties. In this paper we introduce the properties of recently designed new materials for developing phantoms for ultrasonic human body investigation, which in today's market make up more than 30% in the world of phantoms. We developed a novel composite material which allows fabrication of various kinds of ultrasound bone phantoms to mimic most of the acoustical properties of human bones. In contrast to the ex vivo tissues, the proposed material can maintain the physical and acoustical properties unchanged for long periods of time; moreover, these properties can be custom designed and created to suit specific needs. As a result, we introduce three examples of ultrasound phantoms that we manufactured in our laboratory: cortical, trabecular and skull bone phantoms. The paper also presents the results of a comparison study between the acoustical and physical properties of actual human bones (reported in the referenced literatures) and the phantoms manufactured by us.

  13. Collagen-embedded hydroxylapatite-beta-tricalcium phosphate-silicon dioxide bone substitute granules assist rapid vascularization and promote cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Ghanaati, Shahram M; Thimm, Benjamin W; Unger, Ronald E; Orth, Carina; Barbeck, Mike; Kirkpatrick, C James [Institute of Pathology, Johannes Gutenberg-University Mainz, Langenbeckstr.1, 55101 Mainz (Germany); Kohler, Thomas; Mueller, Ralph, E-mail: ghanaati@uni-mainz.d [Institute for Biomechanics, ETH Zuerich, Wolfgang-Pauli-Str.10, 8093 Zuerich (Switzerland)

    2010-04-15

    In the present study we assessed the biocompatibility in vitro and in vivo of a low-temperature sol-gel-manufactured SiO{sub 2}-based bone graft substitute. Human primary osteoblasts and the osteoblastic cell line, MG63, cultured on the SiO{sub 2} biomatrix in monoculture retained their osteoblastic morphology and cellular functionality in vitro. The effect of the biomaterial in vivo and its vascularization potential was tested subcutaneously in Wistar rats and demonstrated both rapid vascularization and good integration within the peri-implant tissue. Scaffold degradation was progressive during the first month after implantation, with tartrate-resistant acid phosphatase-positive macrophages being present and promoting scaffold degradation from an early stage. This manuscript describes successful osteoblastic growth promotion in vitro and a promising biomaterial integration and vasculogenesis in vivo for a possible therapeutic application of this biomatrix in future clinical studies.

  14. Single-beam two-photon three-dimensional optical storage in a pyrryl-substituted fulgide photochromic material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We introduce a high-density three-dimensional optical data storage approach by using a pyrryl-substituted fulgide photochromic material with a method of single-beam two-photon recording and fluorescence confocal readout. The detailed information about the photochromic material and the experimental setup are presented. The experiments about multi-layered recording and readout are carried out with a 100-μm-thick transparent photochromic material film. The results show that the lateral resolution is better than 1 μm, and the longitudinal resolution is about 3 μm. Besides, the readout times for the recorded data are desirable when using a readout laser power smaller than 5 mW.``

  15. Investigating the weight ratio variation of alginate-hydroxyapatite composites for vertebroplasty method bone filler material

    Science.gov (United States)

    Lestari, Gusti Ruri; Yuwono, Akhmad Herman; Sofyan, Nofrijon; Ramahdita, Ghiska

    2017-02-01

    One of the newly developed methods for curing spinal fracture due to osteoporosis is vertebroplasty. The method is basically based on injection of special material directly to the fractured spine in order to commence the formation of new bone. Therefore, appropriate injectable materials are very important to the curing success. In this study, injectable alginate-hydroxyapatite (HA) composites were fabricated varying the weight percentage of alginate upon synthesis procedure. The result of injection capability and compressive tests as well as Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM) suggested that bone filler composite containing 60 wt% alginate is the optimum composition obtaining a compressive modulus up to 0.15 MPa, injection capability of more than 85% and morphology with uniform porous and fibrous structure. This injectable composite fabrication process can be used for the development of injectable materials system for vertebroplasty method.

  16. Tooth Movement out of the Bony Wall Using Augmented Corticotomy with Nonautogenous Graft Materials for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Kye-Bok Lee

    2014-01-01

    Full Text Available This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars for buccal tipping for 6 weeks. The pocket depth and width of keratinized tissue (WKT were measured. Histologic and histomorphometric analyses were performed. The probing depth, WKT, and ratio of the area of new bone to that of total bone on the buccal side were not significantly different between groups. All groups had considerable new bone formation on the pressure side. New bone formation on the buccal side and buccal plate formation in the coronal direction along the root surfaces were induced by the bone-derived and PDL-derived mesenchymal matrix, respectively. The angular change between groups was significantly different (P < 0.001. Augmented corticotomy using nonautogenous graft materials facilitated tooth movement without fenestrations and accelerated new bone formation on the pressure side.

  17. Prediction of Local Ultimate Strain and Toughness of Trabecular Bone Tissue by Raman Material Composition Analysis

    Directory of Open Access Journals (Sweden)

    Roberto Carretta

    2015-01-01

    Full Text Available Clinical studies indicate that bone mineral density correlates with fracture risk at the population level but does not correlate with individual fracture risk well. Current research aims to better understand the failure mechanism of bone and to identify key determinants of bone quality, thus improving fracture risk prediction. To get a better understanding of bone strength, it is important to analyze tissue-level properties not influenced by macro- or microarchitectural factors. The aim of this pilot study was to identify whether and to what extent material properties are correlated with mechanical properties at the tissue level. The influence of macro- or microarchitectural factors was excluded by testing individual trabeculae. Previously reported data of mechanical parameters measured in single trabeculae under tension and bending and its compositional properties measured by Raman spectroscopy was evaluated. Linear and multivariate regressions show that bone matrix quality but not quantity was significantly and independently correlated with the tissue-level ultimate strain and postyield work (r=0.65–0.94. Principal component analysis extracted three independent components explaining 86% of the total variance, representing elastic, yield, and ultimate components according to the included mechanical parameters. Some matrix parameters were both included in the ultimate component, indicating that the variation in ultimate strain and postyield work could be largely explained by Raman-derived compositional parameters.

  18. Operculum bone carp (cyprinus carprio sp.) scaffold is a new potential xenograft material: a preliminary study

    Science.gov (United States)

    Kartiwa, A.; Abbas, B.; Pandansari, P.; Prahasta, A.; Nandini, M.; Fadhlillah, M.; Subroto, T.; Panigoro, R.

    2017-02-01

    Orbital floor fracture with extensive bone loss, would cause herniation of the orbital tissue into the maxillary sinus. Graft implantation should be done on the orbital fracture with extensive bone loss. Different types of grafts have their own characteristics and advantages. Xenograft has been widely studied for use in bone defects. This study was to investigate cyprinus carprio sp. opercula bone as a potential xenograft. The aim of this study was to investigate based on EDS chemical analysis using a ZAF Standardless Method of Quantitative Analysis (Oxide) and SEM examination conducted in the laboratory of Mathematics, Institute of Technology Bandung. Particularly the mass ratio of Ca and P (5.8/3:47), the result is 1.67. This is equivalent to the stoichiometric Hydroxyapatite (HA) (Aoki H, 1991, Science and medical applications of hydroxyapatite, Tokyo: Institute for Medical and Engineering, Tokyo Medical and Dental University). C N O that there is an element of protein/amino acid collagen compound, serves as a matrix together with HA. As shown in the SEM analysis that the matrix is a porous sheet-shaped (oval) that interconnect with each other, which is good scaffold. The pore is composed of large pores >200 microns and smaller pores between the large pores with a size smaller or equal to 10 microns that can serve for the attachment of osteoblast cell. In conclusion, Opercula bone carp (cyprinus carprio sp.) scaffold could be a new potential xenograft material.

  19. An Injectable Hydrogel as Bone Graft Material with Added Antimicrobial Properties

    Science.gov (United States)

    Tommasi, Giacomo; Perni, Stefano

    2016-01-01

    Currently, the technique which provides the best chances for a successful bone graft, is the use of bone tissue from the same patient receiving it (autograft); the main limitations are the limited availability and the risks involved in removing living bone tissue, for example, explant site pain and morbidity. Allografts and xenografts may overcome these limitations; however, they increase the risk of rejection. For all these reasons the development of an artificial bone graft material is particularly important and hydrogels are a promising alternative for bone regeneration. Gels were prepared using 1,4-butanediol diacrylate as crosslinker and alpha tricalciumphosphate; ZnCl2 and SrCl2 were added to the aqueous phase. MTT results demonstrated that the addition of strontium had a beneficial effect on the osteoblast cells density on hydrogels, and zinc instead did not increase osteoblast proliferation. The amount of calcium produced by the osteoblast cells quantified through the Alizarin Red protocol revealed that both strontium and zinc positively influenced the formation of calcium; furthermore, their effect was synergistic. Rheology properties were used to mechanically characterize the hydrogels and especially the influence of crosslinker's concentration on them, showing the hydrogels presented had extremely good mechanical properties. Furthermore, the antimicrobial activity of strontium and zinc in the hydrogels against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis was determined. PMID:27174392

  20. A novel {sup 99m}Tc-labeled dimethyl-substituted zoledronic acid (DMIDP) with improved bone imaging efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, L.; Lin, J.; Luo, S.; Wang, Y.; Cheng, W.; Zhang, S. [Jiangsu Institute of Nuclear Medicine, Wuxi (China). Key Laboratory of Nuclear Medicine

    2012-07-01

    A novel zoledronic acid (ZL) derivative, 1-hydroxy-2-(2,4-dimethyl-1H-imidazol-1-yl)-ethane-1,1-diyldiphosphonic acid (DMIDP, dimezoledronate), was successfully prepared and labeled with {sup 99m}Tc in a high labeling yield. The biodistribution in mice shows that {sup 99m}Tc-DMIDP has significant advantage regarding bone resorption and clearance from soft tissues compared with {sup 99m}Tc-ZL and the clinically widely-used bone-imaging agent {sup 99m}Tc-MDP (methylenediphosphonic acid). Kinetics of blood clearance displayed that distribution half-life (T{sub 1/2{alpha}}) and elimination half-life (T{sub 1/2{beta}}) of {sup 99m}Tc-DMIDP were 2.53 min and 23.53 min, while those of {sup 99m}Tc-ZL were 2.28 and 52.63 min, respectively. Excellent images of the rabbit skeleton can be quickly obtained from {sup 99m}Tc-DMIDP, which was faster than {sup 99m}Tc-ZL and {sup 99m}Tc-MDP. The present findings indicate that {sup 99m}Tc-DMIDP possesses excellent potential for application as a novel bone scanning agent. (orig.)

  1. Validation of an efficient method of assigning material properties in finite element analysis of pelvic bone.

    Science.gov (United States)

    Shim, Vickie B; Battley, Mark; Anderson, Iain A; Munro, Jacob T

    2015-01-01

    Bone in the pelvis is a composite material with a complex anatomical structure that is difficult to model computationally. Rather than assigning material properties to increasingly smaller elements to capture detail in three-dimensional finite element (FE) models, properties can be assigned to Gauss points within larger elements. As part of a validation process, we compared experimental and analytical results from a composite beam under four-point load to FE models with material properties assigned to refined elements and Gauss points within larger elements. Both FE models accurately predicted deformation and the analytical predictions of internal shear stress.

  2. Bovine Calcined Bone for the Repair of Radial Defect in a Rabbit Model

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to investigate the bovine calcined bone's ability of repairing segmental bone defect and seek a new artificial bone substitute material, the bovine calcined bone (450℃,32 h) was implanted into the 10-mm middle radial defect of rabbits with tricalcium phosphate ceramics as the control. By using the methods of histology, radiology and biomechanics their osteogenic ability were measured. It was found that the bovine calcined bone's ability of repairing bone defect was better than that of tricalcium phosphate ceramics. The histological Nilsson′s scores at 3rd, 5th, 9th week after operation were significantly increased (P<0.01). At 12th week after operation the bending strength of radius in experimental group was much higher than that of control group and turned normal. It was suggested that bovine calcined bone is an ideal artificial bone substitute material with good ability of repairing segmental bone defect and some degree of mechanical strength.

  3. Biphasic calcium phosphates (BCP of hydroxyapatite (HA and tricalcium phosphate (TCP as bone substitutes: Importance of physicochemical characterizations in biomaterials studies

    Directory of Open Access Journals (Sweden)

    Mehdi Ebrahimi

    2017-02-01

    Full Text Available The data presented in this article are related to the research article entitled “Biphasic calcium phosphates bioceramics (HA/TCP: Concept, physicochemical properties and the impact of standardization of study protocols in biomaterials research” [1]. This article provides in depth study of BCP bone substitutes as valuable option in the field of tissue engineering. However, there are discrepancies in the literature regarding the ideal physicochemical properties of BCP and the ideal balance between different phase compositions for enhanced bone tissue engineering (M. Ebrahimi, M.G. Botelho, S.V. Dorozhkin, 2016; M. Ebrahimi, P. Pripatnanont, S. Suttapreyasri, N. Monmaturapoj, 2014 [1,2]. This is found to be mainly because of improper characterization of BCP bioceramics in basic studies and lack of standard study protocols in in vitro and in vivo research. This data article along with original article provide the basic data required for ideal characterization of BCP and other bioceramics in an attempt to provide basic standardized protocols for future studies.

  4. Properties of the "Orgamax" osteoplastic material made of a demineralized allograft bone

    Science.gov (United States)

    Podorognaya, V. T.; Kirilova, I. A.; Sharkeev, Yu. P.; Uvarkin, P. V.; Zhelezny, P. A.; Zheleznaya, A. P.; Akimova, S. E.; Novoselov, V. P.; Tupikova, L. N.

    2016-08-01

    We investigated properties of the "Orgamax" osteoplastic material, which was produced from a demineralized bone, in the treatment of extensive caries, in particular chronic pulpitis of the permanent teeth with unformed roots in children. The "Orgamax" osteoplastic material consists of demineralized bone chips, a collagen additive, and antibiotics. The surface morphology of the "Orgamax" osteoplastic material is macroporous, with the maximum pore size of 250 µm, whereas the surface morphology of the major component of "Orgamax", demineralized bone chips, is microporous, with a pore size of 10-20 µm. Material "Orgamax" is used in the treatment of complicated caries, particularly chronic pulpitis of permanent teeth with unformed roots in children. "Orgamax" filling a formed cavity exhibits antimicrobial properties, eliminates inflammation in the dental pulp, and, due to its osteoconductive and osteoinductive properties, undergoes gradual resorption, stimulates regeneration, and provides replacement of the defect with newly formed tissue. The dental pulp viability is completely restored, which ensures the complete formation of tooth roots with root apex closure in the long-term period.

  5. TU-A-12A-08: Computing Longitudinal Material Changes in Bone Metastases Using Dual Energy Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schmidtlein, CR; Hwang, S; Veeraraghavan, H; Fehr, D; Humm, J; Deasy, J [Memorial Sloan Kettering Cancer Center, New York, NY (United States)

    2014-06-15

    Purpose: This study demonstrates a methodology for tracking changes in metastatic bone disease using trajectories in material basis space in serial dual energy computed tomography (DECT) studies. Methods: This study includes patients with bone metastases from breast cancer that had clinical surveillance CT scans using a General Electric CT750HD in dual energy mode. A radiologist defined regions-of-interested (ROI) for bone metastasis, normal bone, and marrow across the serial DECT scans. Our approach employs a Radon transform to forward-projection the basis images, namely, water and iodine, into sinogram space. This data is then repartitioned into fat/bone and effective density/Z image pairs using assumed energy spectrums for the x-ray energies. This approach both helps remove negative material densities and avoids adding spectrum-hardening artifacts. These new basis data sets were then reconstructed via filtered back-projection to create new material basis pair images. The trajectories of these pairs were then plotted in the new basis space providing a means to both visualize and quantitatively measure changes in the material properties of the tumors. Results: ROI containing radiologist defined metastatic bone disease showed well-defined trajectories in both fat/bone and effective density/Z space. ROI that contained radiologist defined normal bone and marrow did not exhibit any discernible trajectories and were stable from scan to scan. Conclusions: The preliminary results show that changes in material composition and effective density/Z image pairs were seen primarily in metastasis and not in normal tissue. This study indicates that by using routine clinical DECT it may be possible to monitor therapy response of bone metastases because healing or worsening bone metastases change material composition of bone. Additional studies are needed to further validate these results and to test for their correlation with outcome.

  6. Tensile material properties of human rib cortical bone under quasi-static and dynamic failure loading and influence of the bone microstucture on failure characteristics

    CERN Document Server

    Subit, Damien; Valazquez-Ameijide, Juan; Arregui-Dalmases, Carlos; Crandall, Jeff

    2011-01-01

    Finite element models of the thorax are under development to assist vehicle safety researchers with the design of countermeasures such as advanced restrain systems. Computational models have become more refined with increasing geometrical complexity as element size decreases. These finite element models can now capture small geometrical features with an attempt to predict fracture. However, the bone material properties currently available, and in particular the rate sensitivity, have been mainly determined from compression tests or tests on long bones. There is a need for a new set of material properties for the human rib cortical bone. With this objective, a new clamping technique was developed to test small bone coupons under tensile loading. Ten coupons were harvested from the cortical shell of the sixth and seventh left ribs from three cadavers. The coupons were tested to fracture under quasi-static (target strain rate of 0.07 %/s) and dynamic loading (target strain rate of 170 %/s). Prior to testing, eac...

  7. Effect of substitutional defects on Kambersky damping in L1{sub 0} magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Qu, T. [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Victora, R. H., E-mail: victora@umn.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2015-02-16

    Kambersky damping, representing the loss of magnetic energy from the electrons to the lattice through the spin orbit interaction, is calculated for L1{sub 0} FePt, FePd, CoPt, and CoPd alloys versus chemical degree of order. When more substitutional defects exist in the alloys, damping is predicted to increase due to the increase of the spin-flip channels allowed by the broken symmetry. It is demonstrated that this corresponds to an enhanced density of states (DOS) at the Fermi level, owing to the rounding of the DOS with loss of long-range order. Both the damping and the DOS of the Co-based alloy are found to be less affected by the disorder. Pd-based alloys are predicted to have lower damping than Pt-based alloys, making them more suitable for high density spintronic applications.

  8. SUBSTITUTED IRON OXIDES FOR THE GRANT ENTITLED LASER PROCESSING OF ADVANCED MAGNETIC MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Monica Sorescu

    2004-03-01

    Structural and morphological characteristics of (1-x){alpha}-Fe{sub 2}O{sub 3}-xSnO{sub 2} (x = 0.0-1.0) nanoparticles obtained under hydrothermal conditions have been investigated by X-ray diffraction (XRD), transmission Moessbauer spectroscopy, scanning (SEM) and transmission electron microscopy (TEM) as well as energy dispersive X-ray analysis (EDX). On the basis of the Rietveld structure refinements of the XRD spectra at low tin concentrations, it was found that Sn{sup 4+} ions partially substitute for Fe{sup 3+} at the octahedral sites and also occupy the interstitial octahedral sites which are vacant in {alpha}-Fe{sub 2}O{sub 3} corundum structure. A phase separation of {alpha}-Fe{sub 2}O{sub 3} and SnO{sub 2} was observed for x {ge} 0.4: the {alpha}-Fe{sub 2}O{sub 3} structure containing tin decreases simultaneously with the increase of the SnO{sub 2} phase containing substitutional iron ions. The mean particle dimension decreases from 70 nm to 6 nm, as the molar fraction x increases up to x = 1.0. The estimated solubility limits in the nanoparticle system (1-x){alpha}-Fe{sub 2}O{sub 3}-xSnO{sub 2} synthesized under hydrothermal conditions are: x {le} 0.2 for Sn{sup 4+} in {alpha}-Fe{sub 2}O{sub 3} and x {ge} 0.7 for Fe{sup 3+} in SnO{sub 2}. These findings are in press in the Journal of Physics and Chemistry of Solids.

  9. Injectable calcium phosphate cement for bone repair and implant fixation.

    NARCIS (Netherlands)

    Jansen, J.; Ooms, E.M.; Verdonschot, N.J.J.; Wolke, J.G.C.

    2005-01-01

    The studies as described are aimed at determining the efficacy of newly developed calcium phosphate cement when this material is used as a bone defect filler or gap filler around metal implants. An overview is provided about bone graft substitutes and methods of metal implant fixation.

  10. Tooth movement out of the bony wall using augmented corticotomy with nonautogenous graft materials for bone regeneration.

    Science.gov (United States)

    Lee, Kye-Bok; Lee, Dong-Yeol; Ahn, Hyo-Won; Kim, Seong-Hun; Kim, Eun-Cheol; Roitman, Igor

    2014-01-01

    This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars for buccal tipping for 6 weeks. The pocket depth and width of keratinized tissue (WKT) were measured. Histologic and histomorphometric analyses were performed. The probing depth, WKT, and ratio of the area of new bone to that of total bone on the buccal side were not significantly different between groups. All groups had considerable new bone formation on the pressure side. New bone formation on the buccal side and buccal plate formation in the coronal direction along the root surfaces were induced by the bone-derived and PDL-derived mesenchymal matrix, respectively. The angular change between groups was significantly different (P tooth movement without fenestrations and accelerated new bone formation on the pressure side.

  11. Choice of osteoplastic materials for bone regeneration in the treatment of patients with generalized periodontitis with diabetes mellitus tape 2.

    Directory of Open Access Journals (Sweden)

    Gudaryan A.A.

    2014-11-01

    Full Text Available The article presents the results of a comparative study of using osteoinductive and osteoconductive material for bone osteoplastic grafting used to perform operations in the treatment of 60 patients with generalized periodontitis with diabetes mellitus type 2. It was found that by using different types of materials osteoplastic bone growth occurs differently. It was found that in preserved walls of bone pockets a mixture of osteoinductive material «Bio-Oss», combined with osteoconductive material osteoplastic «BondBone» prepared in platelet-rich plasma using collagen membranes «Bio-Gide» is enough and appropriate to use. This technique allowed achieving full recovery of bone in 86.2% of patients bone defects with. It was found that by using natural osteoplastic material «Bio-Oss» with extensive periodontal regeneration of alveolar bone defects in patients with generalized periodontitis associated with diabetes mellitus type 2 it is necessary to use membranes of polylactic acid to prevent migration of particles of osteoplastic material in the wound.

  12. Demineralized bone matrix as a bone tissue engineering scaffold material%骨组织工程支架材料:脱矿骨基质

    Institute of Scientific and Technical Information of China (English)

    陈海霞; 谢志刚

    2014-01-01

    BACKGROUND:Demineralized bone matrix as bone tissue engineering biological scaffold material is more researched currently, which has osteoinductive and osteoconductive. OBTECTIVE:To summarize the development of demineralized bone matrix as bone tissue engineering scaffold material and to prospect its trend. METHODS:The relative literatures addressing demineralized bone matrix as bone tissue engineering scaffold material published between January 1965 and May 2013 in PubMed database, Chinese Biomedical Database, Wanfang Database and FMJS database were searched by the first author. The key words were“demineralized bone matrix, scaffold material, growth factor, cells, drugs”in English and Chinese. According to the inclusion criteria, repetitive researches were excluded, and final y 34 articles were included. RESULTS AND CONCLUSION:Scaffold material is the key composition of tissue engineered bone, and only demineralized bone matrix has both osteoinductive and osteoconductive properties which cannot only provide space for bone repair, but also can be combined with bioactive factors, living cells, antibiotics in vitro to construct bone graft thereby promoting healing of bone defects. However, this technique is also facing some problems to be solved such as the ratio of demineralized bone matrix and various substances, disinfection, preservation of osteogenetic activity and antigenicity elimination. Sufficiently understanding demineralized bone matrix as bone tissue engineering scaffold can provide a theoretical basis for its clinical service.%背景:脱矿骨基质是目前研究较多的具备骨诱导及骨引导的生物支架材料之一。目的:总结脱矿骨基质作为骨组织工程支架材料的研究进展,并展望其发展趋势。  方法:由第一作者检索1965年1月至2013年5月PubMed数据库、中国生物医学数据库、万方数据库及FMJS数据库有关脱矿骨基质及其作为骨组织工程支架材料的相关文

  13. Obesity-related changes in bone structural and material properties in hyperphagic OLETF rats and protection by voluntary wheel running

    Science.gov (United States)

    We conducted a study to examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. This was a 36-week study of sedentary, hyperphag...

  14. Composites organiques-inorganiques pour la substitution et la réparation osseuse : concepts, premiers résultats et potentialités Organic-inorganic composites for bone substitute and bone repair applications: concepts, first results and potentialities

    Directory of Open Access Journals (Sweden)

    Peroglio Marianna

    2013-11-01

    Full Text Available Ce document présente un très bref aperçu de l'intérêt des matériaux composites organique – inorganique pour la substitution et la réparation osseuse. Deux types de composites sont présentés. Dans une première partie, des matériaux poreux en céramique ou bio-verre élaborés par la technologie des poudres sont imprégnés par un polymère. Cette imprégnation se traduit par une forte augmentation de l'énergie à la rupture du squelette céramique, permettant de limiter le risque de rupture fragile. L'augmentation des propriétés mécaniques des substituts osseux céramiques par une phase polymère peut être mise en regard des mécanismes de renforcement présents dans l'os et du rôle du collagène sur la ténacité de celui-ci. Dans une deuxième partie, des composites denses sont élaborés par des technologies de plasturgie, qui permettent de réaliser des produits de formes complexes. Les phases polymères et céramiques sont ici choisies pour leurs caractères respectifs résorbable et ostéo-inducteur. Ces composites permettent la création rapide d'hydroxyapatite à leur surface et accélèrent la guérison osseuse. A terme, ils sont résorbés. Ces deux exemples démontrent les potentialités de tels multi-matériaux architecturés pour la réalisation de substituts osseux plus résistants mécaniquement et apportant de nouvelles fonctionnalités, ainsi que pour la production de produits d'ostéosynthèse favorisant les processus de guérison osseuse. Here we show a brief outline of organic-inorganic composites for bone substitute and bone repair applications. Two types of composites are presented. In a first strategy, porous ceramics and bioactive glasses processed by sintering methods are impregnated by a polymer. The strong improvement of the mechanical properties of the ceramic scaffolds by a polymer phase can be linked to the one present in bone with the role of collagen on bone toughness. In a second strategy, a

  15. Morphological and pharmacological investigation on some biopotent materials derived from substituted pyrimidine and imidazole enzyme constituents

    Science.gov (United States)

    Shobana, Sutha; Subramaniam, Perumal; Dharmaraja, Jeyapraksh; Narayan, Arvind

    Coordinating behavior of novel N2O type mixed ligand complexes (1-6) have been synthesized from substituted fluoropyrimidine [5-Fluorouracil (5-FU; A)] with biopotent imidazole enzyme constituents (B) viz., imidazole(him) and benzimidazole(bim) in the presence of Ni(II), Cu(II) and Zn(II) ions. Synthesized complexes were characterized by chemical analysis, spectral studies, magnetic moment and conductivity measurements. The results of chemical analysis and the observed low molar conductance values propose their stoichiometry to be 1:1:1 (M:A:B) with non-electrolytic nature. From the spectral data, it is inferred that the ligands A & B coordinate with M(II) ions in bi and monodentate approach through C(4)dbnd O, N(3) and imidazole ring N(3) atoms respectively. The thermogravimetric analysis shows the dehydration, decomposition and thermal stability of mixed ligand complexes. XRD and SEM patterns show sharp crystalline peaks with homogeneous morphology. In vitro antimicrobial activities of free ligands (A & B) and their metal complexes were screened against some pathogenic strains by well diffusion technique. Absorption and gel electrophoresis experiments on the interaction of mixed ligand complexes with DNA suggest that all the complexes can bind as well as cleave the DNA by intercalation between chromophores and DNA base pairs. In addition, in vitro antioxidant activities were tested by DPPH free radical scavenging model.

  16. Asymmetrically substituted 5,5'-bistriazoles--nitrogen-rich materials with various energetic functionalities.

    Science.gov (United States)

    Dippold, Alexander A; Klapötke, Thomas M; Oswald, Michaela

    2013-08-21

    In this contribution the synthesis and full structural and spectroscopic characterization of three asymmetrically substituted bis-1,2,4-triazoles, along with different energetic moieties like amino, nitro, nitrimino and azido moieties, is presented. Additionally, selected nitrogen-rich ionic derivatives have been prepared and characterized. This comparative study on the influence of these energetic moieties on structural and energetic properties constitutes a complete characterization including IR, Raman and multinuclear NMR spectroscopy. Single crystal X-ray crystallographic measurements were performed and provide insight into structural characteristics as well as inter- and intramolecular interactions. The standard enthalpies of formation were calculated for all compounds at the CBS-4M level of theory, revealing highly positive heats of formation for all compounds. The detonation parameters were calculated using the EXPLO5 program and compared to the common secondary explosive RDX as well as recently published symmetric bistriazoles. As expected, the measured sensitivities to mechanical stimuli and decomposition temperatures strongly depend on the energetic moiety of the triazole ring. All compounds were characterized in terms of sensitivities (impact, friction, electrostatic) and thermal stabilities, the ionic derivatives were found to be thermally stable, insensitive compounds.

  17. Microstructure, cytotoxicity and corrosion of powder-metallurgical iron alloys for biodegradable bone replacement materials

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Bernd; Sievers, Birte; Utzschneider, Sandra; Mueller, Peter; Jansson, Volkmar [Department of Orthopedic Surgery, Ludwig-Maximilians-University of Munich, Marchioninistrasse 15, 81377 Muenchen (Germany); Roessler, Sophie; Nies, Berthold [InnoTERE GmbH, Tatzberg 47, 01307 Dresden (Germany); Stephani, Guenter; Kieback, Bernd [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany); Quadbeck, Peter, E-mail: peter.quadbeck@ifam-dd.fraunhofer.de [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany)

    2011-12-15

    Up to now biodegradable bone implants with the ability of bearing high loads for the temporary replacement of bones or as osteosynthesis material are not available. Iron and iron based alloys have been identified as appropriate materials, since they combine high strength at medium corrosion rates. Thus, the aim of the present study is the development of a degradable iron based alloy with the perspective of using them as matrix material of cellular structures with biomechanical tailored properties. A powder metallurgical approach has been used to manufacture Fe-C, Fe-0.6P, Fe-1.6P, Fe-B and Fe-Ag samples, which have been tested with respect to their microstructure, their cytotoxicity, and their degradation rate. In order to determine the cytotoxicity of the material a monolayer culture of fibroblast and a perfusion chamber system has been chosen, which was recommended by the ISO 10993-5:1999 for biological testing of medical devices. It has been found, that in particular phosphorus features beneficial properties, since density and thus the strength of the material are increased. No corrosion inhibiting effects of phosphorus on the degradation rate have been found.

  18. 19. network conference: Substitute fuels - from waste material to product. Proceedings; 19. Netzwerktreffen: Ersatzbrennstoffe - vom Abfall zum Produkt. Konferenzband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Substitute fuels are in great demand, both from the view of waste management and as substitutes for increasingly expensive fuels. According to German law, the share of renewable energy sources in electric power supply is to increase from the present 6 percent to 12.5 percent by 2010. In Europe, the current 14 percent are to increase to 22 during the same period. There are still unresolved problems, however, e.g. origins of raw materials for substitute fuel production; collecting and conditioning; logistic problems of distribution; experience of producers and users; long-term availability. These problems, as well as some other ones, were discussed at the 19th network conference, as were requirements made on substitute fuels and their applications. Experts from economy, politics and science were given a platform for discussion, generation of knowledge, information transfer, and exchange of experience. (orig.) [German] Ersatzbrennstoffe liegen zur Zeit voll im Trend. Aus gutem Grund, denn zum einen dienen sie nach Vorgabe des Kreislaufwirtschafts- und Abfallgesetzes sowie der TA Siedlungsabfall als heizwertreiche Fraktion zur energetischen Verwertung. Zum anderen substituieren sie teure Regelbrennstoffe, und dies nicht nur in energieintensiven Branchen. Der Gesetzgebung folgend soll in Deutschland der Anteil der erneuerbaren Energien an der Stromerzeugung von derzeit 6 % auf 12,5 % im Jahr 2010 steigen. In ganz Europa soll der Anteil von derzeit 14 % auf 22 % anwachsen. Fur erneuerbare Energien, hierunter fallen biogene Ersatzbrennstoffe, existiert folglich ein Wachstumsmarkt. Es bleiben jedoch einige Fragen offen: Wo kommen die Abfaelle bzw. Rohstoffe zur Erzeugung von Ersatzbrennstoffen her? Wie erfolgen Erfassung und Aufbereitung? Welche logistischen Anforderungen existieren hinsichtlich der Distribution? Welche Erfahrungen sammeln derzeit Produzenten und Verwerter? Sind die Ersatzbrennstoffe auch zukunftig in ausreichender Menge fuer die angestrebte energetische

  19. Material-related effects of BMP-2 delivery systems on bone regeneration.

    Science.gov (United States)

    Hernández, Antonio; Sánchez, Esther; Soriano, Isabel; Reyes, Ricardo; Delgado, Araceli; Évora, Carmen

    2012-02-01

    Material-related effects of a brushite and a PLGA controlled release system loaded with two distinct doses of bone morphogenetic protein-2 (BMP-2) (3.5 and 17.5 μg), pre-encapsulated in poly(lactic-co-glycolic acid) (PLGA), were investigated in an intramedullary femur defect model in rabbits. The systems were characterized in vitro and in vivo over 12 weeks in terms of morphology, release kinetics, porosity, molecular weight, and composition using scanning electron microscopy, mercury porosimetry, radioactivity counting, X-ray diffractometry, differential scanning calorimetry, and gel permeation chromatography. During the experimental period the investigated systems underwent significant changes in vitro as well as in vivo. It should be stressed that the two in vitro release patterns were similar, however in vivo parallel profiles were observed with a higher burst effect for BMP-2 in the PLGA system. The PLGA system degraded and disintegrated significantly faster than the brushite system, which suffered slowly progressing external erosion and, additionally, material resorption by osteoclasts in vivo. The consequences of this were reflected in the degree of bone regeneration. Although a sustained delivery of BMP-2 was achieved with both systems, the brushite construct, independent of the loaded growth factor dose, failed to consistently induce defect repair, a result attributed to its slow resorption rate. In contrast, the PLGA system resulted in complete regeneration with mature trabecular bone formation 8 weeks after implantation.

  20. Thermosetting composite matrix materials based on allyl and/or propargyl substituted cyclopentadiene, indene and fluorene

    Science.gov (United States)

    Tregre, Gregory Jude

    A series of all-hydrocarbon thermoset composite matrix resins was synthesized via electrophilic substitution of cyclopentadiene, indene, and fluorene ring systems with allyl and/or propargyl halides under phase transfer conditions. Reaction of cyclopentadiene with allyl chloride (ACP resin), propargyl bromide (PCP resin) or various feed ratios of allyl chloride and propargyl bromide (APCP resins) yielded mixtures of products with 2-6 substituents per cyclopentadiene ring. Reaction of indene with allyl chloride (Al resins) or propargyl bromide (PI resins) yielded mixtures of products with 2-4 substituents per indene. In both sets of resins the allyl functionality obtained a greater average degree of substitution than the analogous propargyl species. Differential scanning calorimetric (DSC) analysis of the multifunctional resins showed broad, high-energy thermal cures in all cases. The enthalpies of cure for ACP and PCP were 750 J/g and 805 J/g, respectively, with peak cure energies occurring at 310 and 248sp°C. The enthalpy of cure for APCP resins ranged from 750 J/g to 800 J/g with higher propargyl-functional resins yielding higher enthalpies of cure. Physically mixed ACP/PCP resin systems gave peak cure temperatures and energy values comparable to APCP resins. The enthalpies of cure for Al and PI-resins were 480 J/g and 630 J/g, respectively. Peak cure temperature for Al resin was 320sp°C, while the peak cure for PI resin occurred at 282sp°C. Infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR) were used to evaluate mechanisms of cure in the experimental resins. The allyl functional resins cured through a combination of ene reactions and polyaddition reactions. The propargyl functional resins cured through ene reactions and polyadditions but also underwent some cyclotrimerization of the propargyl functionalities. A small amount of autoxidation was seen in all of the resins. Thermal stability and carbon yields of the cured resins were

  1. Study on β-TCP Coated Porous Mg as a Bone Tissue Engineering Scaffold Material

    Institute of Scientific and Technical Information of China (English)

    Fang Geng; Lili Tan; Bingchun Zhang; Chunfu Wu; Yonglian He; Jingyu Yang; Ke Yang

    2009-01-01

    Three-dimensional honeycomb-structured magnesium (Mg) scaffolds with interconnected pores of accurately controlled pore size and porosity were fabricated by laser perforation technique. Biodegradable and bioactive β-tricalcium phosphate (β-TCP) coatings were prepared on the porous Mg to further improve its biocompatibility, and the biodegradation mechanism was simply evaluated in vitro. It was found that the mechanical properties of this type of porous Mg significantly depended on its porosity. Elastic modulus and compressive strength similar to human bones could be obtained for the porous Mg with porosity of 42.6%-51%. It was observed that the human osteosarcoma cells (UMR106) were well adhered and proliferated on the surface of the β-TCP coated porous Mg, which indicates that the β-TCP coated porous Mg is promising to be a bone tissue engineering scaffold material.

  2. Bone marrow histopathology in the diagnostic evaluation of splenic marginal-zone and splenic diffuse red pulp small B-cell lymphoma: a reliable substitute for spleen histopathology?

    Science.gov (United States)

    Ponzoni, Maurilio; Kanellis, George; Pouliou, Evi; Baliakas, Panagiotis; Scarfò, Lydia; Ferreri, Andrés J M; Doglioni, Claudio; Bikos, Vasilis; Dagklis, Antonis; Anagnostopoulos, Achilles; Ghia, Paolo; Stamatopoulos, Kostas; Papadaki, Theodora

    2012-11-01

    Primary splenic small B-cell lymphomas mostly comprise the distinct entity of splenic marginal-zone lymphoma (SMZL) and the provisional category of splenic lymphoma/leukemia unclassifiable, mainly represented by the hairy cell leukemia variant and splenic diffuse red pulp small B-cell lymphoma (SDRL). Until recently, histopathologic examination of splenectomy specimens was considered mandatory for the diagnosis of SMZL. However, nowadays, mainly because of advances in chemoimmunotherapy, splenectomy is performed much less frequently. We evaluated the diagnostic efficacy of bone marrow biopsy (BMB) histopathology in the diagnostic approach toward SMZL and SDRL and tested whether it may serve as a substitute for spleen histopathology in the differential diagnosis between these 2 entities. To this end, we conducted a paired assessment of BMB and spleen diagnostic samples from 46 cases with a diagnosis of SMZL (n=32) or SDRL (n=14) based on spleen histopathology. We demonstrate that detailed immunohistopathologic BMB evaluation offers adequate evidence for the confirmation of these entities and their differential diagnosis from other small B-cell lymphoma histotypes. Notably, the immunophenotypical profile of SMZL and SDRL was identical in both BMB and spleen specimens for 21 evaluated markers. Paired assessment of BMB and spleen specimens did not identify discriminating patterns of BMB infiltration, cytology, and/or immunohistology between SMZL and SDRL. Accordingly, bone marrow histopathology contributes significantly in confirming the diagnosis of SMZL and SDRL. However, presently it is not possible to distinguish SMZL from SDRL on the basis of BMB evaluation alone; hence, histopathologic examination of the spleen remains the "gold standard" approach.

  3. Transition metal substituted SrTiO3 perovskite oxides as promising functional materials for oxygen sensor

    Science.gov (United States)

    Misra, Sunasira

    2012-07-01

    Modern industries employ several gases as process fluids. Leakage of these gases in the operating area could lead to undesirable consequences. Even in chemical industries, which use large quantities of inert gases in confined areas, accidental leakage of these process gases would result in the reduction of oxygen partial pressure in atmospheric air. For instance, large amounts of gaseous nitrogen and argon are used in pharmaceutical industries, gas filling/bottling plants, operating area of Fast Breeder reactors, etc. Fall of concentration of oxygen in air below 17% could lead to life risk (Asphyxiation) of the working personnel that has to be checked well in advance. Further, when the leaking gas is of explosive nature, its damage potential would be very high if its concentration level in air increases beyond its lower explosive limit. Surveillance of the ambient within these industries at the critical areas and also in the environment around them for oxygen therefore becomes highly essential. Sensitive and selective gas sensors made of advanced materials are required to meet this demand of monitoring environmental pollution. The perovskite class of oxides (ABO3) is chemically stable even at high temperatures and can tolerate large levels of dopants without phase transformations. The electronic properties of this parent functional material can be tailored by adding appropriate dopants that exhibit different valence states. Aliovalent transition metal substituted SrTiO3 perovskites are good mixed ionic and electronic conductors and potential candidates for sensing oxygen at percentage level exploiting their oxygen pressure dependent electrical conductivity. This paper presents the preparation, study of electrical conductivity and oxygen-sensing characteristics of iron and cobalt substituted SrTiO3.

  4. Ordinary and Activated Bone Grafts: Applied Classification and the Main Features

    Directory of Open Access Journals (Sweden)

    R. V. Deev

    2015-01-01

    Full Text Available Bone grafts are medical devices that are in high demand in clinical practice for substitution of bone defects and recovery of atrophic bone regions. Based on the analysis of the modern groups of bone grafts, the particularities of their composition, the mechanisms of their biological effects, and their therapeutic indications, applicable classification was proposed that separates the bone substitutes into “ordinary” and “activated.” The main differential criterion is the presence of biologically active components in the material that are standardized by qualitative and quantitative parameters: growth factors, cells, or gene constructions encoding growth factors. The pronounced osteoinductive and (or osteogenic properties of activated osteoplastic materials allow drawing upon their efficacy in the substitution of large bone defects.

  5. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  6. Zwitterionic Cellulose Carbamate with Regioselective Substitution Pattern: A Coating Material Possessing Antimicrobial Activity.

    Science.gov (United States)

    Elschner, Thomas; Lüdecke, Claudia; Kalden, Diana; Roth, Martin; Löffler, Bettina; Jandt, Klaus D; Heinze, Thomas

    2016-04-01

    A polyzwitterion is synthesized by regioselective functionalization of cellulose possessing a uniform charge distribution. The positively charged ammonium group is present at position 6, while the negative charge of carboxylate is located at positions 2 and 3 of the repeating unit. The molecular structure of the biopolymer derivative is proved by NMR spectroscopy. This cellulose-based zwitterion is applied to several support materials by spin-coating and characterized by means of atomic force microscope, contact angle measurements, ellipsometry, and X-ray photoelectron spectroscopy. The coatings possess antimicrobial activity depending on the support materials (glass, titanium, tissue culture poly(styrene)) as revealed by confocal laser scanning microscopy and live/dead staining.

  7. Theoretical and Computational Studies of Rare Earth Substitutes: A Test-bed for Accelerated Materials Development

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, Lorin X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    Hard permanent magnets in wide use typically involve expensive Rare Earth elements. In this effort, we investigated candidate permanent magnet materials which contain no Rare Earths, while simultaneously exploring improvements in theoretical methodology which enable the better prediction of magnetic properties relevant for the future design and optimization of permanent magnets. This included a detailed study of magnetocrystalline anisotropy energies, and the use of advanced simulation tools to better describe magnetic properties at elevated temperatures.

  8. Searching for new energetic materials: Computational design of novel nitro-substituted heterocyclic explosives

    Science.gov (United States)

    Tsyshevsky, Roman V.; Pagoria, Philip; Kuklja, Maija M.

    2017-01-01

    The continuous search for safe and powerful energetic materials is an exciting research challenge that attracts experts in material science, chemistry, physics, and engineering. Elucidation of meaningful relationships between sensitivity and structures of explosives is a fundamental problem, which needs to be addressed to ensure successful design of new materials and improvements of existing energetics. In this paper, quantum-chemical DFT study of thermal decomposition of a series of recently synthesized oxadiazole-based explosives, BNFF (3,4-bis(4-Nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole-N-oxide), BNFF-1 (3,4-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole) and ANFF-1 (3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole) is presented. We also show how the knowledge of discovered interplay between the structures and thermal stability of these compounds is used to design several novel candidate heterocyclic energetic molecules, including DNBTT (2,7-dinitro-4H,9H-bis([1,2,4]triazolo)[1,5-b:1',5'-e][1,2,4,5]tetrazine), the compound with high thermal stability, which is on predicted to be par or better than that of TATB.

  9. 复合α-TCP透磷灰石骨水泥材料的生物相容性研究%Biocompatibility of α-TCP brushite bone cement material

    Institute of Scientific and Technical Information of China (English)

    马建敏; 杨洪; 王凯; 刘璨; 赵慧娟

    2012-01-01

    目的:观察复合α-TCP透磷灰石骨水泥的生物相容性,为该复合骨水泥的临床应用提供动物组织学实验依据.方法:在β-TCP+ MCPM骨水泥的基础上添加α-TCP,得到一种改进型透磷灰石骨水泥.以传统的透磷灰石骨水泥为对照组,对其进行体外溶血试验、热源试验、急性毒性试验、皮肤过敏试验、肌内植入试验.结果:α-TCP透磷灰石骨水泥的溶血率<5%,无热源性、无毒性、无皮肤过敏,植入肌肉后无明显炎症反应.结论:α-TCP的透磷灰石骨水泥具有良好的生物相容性和安全性,可作为体内骨替换材料.%AIM: To investigate the biocompatibility of α-TCP brushite bone cement. METHOD; a-TCP was introduced to β-TCP + MCPM bone cement to obtain α-TCP brashite bone cement. The material was evaluated by hemulysis test, pyrogen test, acute toxicity test, skin allergy test and muscle implant test. The bioeompatibility of α-TCP brushite bone cement was compared with traditional brushite bone cement. RESULTS: The hemolysis rate of α-TCP brushite bone cement was below 5 percent. No pyrogenic, no toxic, no skin allergic, and no obvious inflammatory reaction were observs. CONCLUSION: The α-TCP brushite bone cement shows excellent biocompatibilily and safety, tence can be used in vivo as a bone substitute material.

  10. Oil Palm Biomass As Potential Substitution Raw Materials For Commercial Biomass Briquettes Production

    Directory of Open Access Journals (Sweden)

    A. B. Nasrin

    2008-01-01

    Full Text Available Palm oil industry generates vast amount of palm biomass. Converting palm biomass into a uniform and solid fuel through briquetting process appears to be an attractive solution in upgrading its properties and add value. In this study, raw materials including empty fruit bunch (EFB, in powder and fibre forms, palm kernel expeller (PKE and sawdust were densified into briquettes at high temperature and pressure using screw extrusion technology. The briquettes were analysed to determine its physical and chemical properties, mechanical strength and burning characteristics. It was found that briquettes made either from 100% pulverized EFB or mixed with sawdust exhibited good burning properties. EFB fibre and PKE, due to their physical properties, were recommended to be blended with sawdust in producing quality briquettes. In overall, converting palm biomass into briquettes has increased its energy content and reduced moisture content about minimum of 5% and 38% respectively compared to its raw materials. The properties of palm biomass briquettes obtained from the study were compared to the commercial sawdust briquettes properties and to the minimum requirements of DIN 51731. The details of the study were highlighted in this paper. Palm biomass briquettes can become an important renewable energy fuel source in the future.

  11. Characterising structural, mechanical and cytotoxic properties of coral-based composite material intended for bone implant applications

    Directory of Open Access Journals (Sweden)

    Angela Samper Gaitán

    2011-08-01

    Full Text Available Studies concerning the application of Porites asteroides coral for bone implant purposes have demonstrated the biological viability of its use. As a complement to previous research regarding the development of bone-powder based composite materials which are useful for such applications, this study was aimed at developing a coral powder-based composite material which would be able to satisfy the appropriate structural, mechanical and cytotoxic properties required for its use. A composite material made of coral powder, calcium sulphate powder and water was therefore developed, and its properties were tested in different compositions. The results showed how the resulting composite material had properties which were comparable to those of human cortical bone (from both a structural and mechanical point of view, as well as being non-toxic below a 0.35 mg/ml critical composite material concentration.

  12. Facile synthesis, characterization, and antimicrobial activity of cellulose-chitosan-hydroxyapatite composite material: a potential material for bone tissue engineering.

    Science.gov (United States)

    Mututuvari, Tamutsiwa M; Harkins, April L; Tran, Chieu D

    2013-11-01

    Hydroxyapatite (HAp) is often used as a bone-implant material because it is biocompatible and osteoconductive. However, HAp possesses poor rheological properties and it is inactive against disease-causing microbes. To improve these properties, we developed a green method to synthesize multifunctional composites containing: (1) cellulose (CEL) to impart mechanical strength; (2) chitosan (CS) to induce antibacterial activity thereby maintaining a microbe-free wound site; and (3) HAp. In this method, CS and CEL were co-dissolved in an ionic liquid (IL) and then regenerated from water. HAp was subsequently formed in situ by alternately soaking [CEL+CS] composites in aqueous solutions of CaCl2 and Na2 HPO4 . At least 88% of IL used was recovered for reuse by distilling the aqueous washings of [CEL+CS]. The composites were characterized using FTIR, XRD, and SEM. These composites retained the desirable properties of their constituents. For example, the tensile strength of the composites was enhanced 1.9 times by increasing CEL loading from 20% to 80%. Incorporating CS in the composites resulted in composites which inhibited the growth of both Gram positive (MRSA, S. aureus and VRE) and Gram negative (E. coli and P. aeruginosa) bacteria. These findings highlight the potential use of [CEL+CS+HAp] composites as scaffolds in bone tissue engineering.

  13. Material rhetoric: spreading stones and showing bones in the study of prehistory.

    Science.gov (United States)

    Van Reybrouck, David; de Bont, Raf; Rock, Jan

    2009-06-01

    Since the linguistic turn, the role of rhetoric in the circulation and the popular representation of knowledge has been widely accepted in science studies. This article aims to analyze not a textual form of scientific rhetoric, but the crucial role of materiality in scientific debates. It introduces the concept of material rhetoric to understand the promotional regimes in which material objects play an essential argumentative role. It analyzes the phenomenon by looking at two students of prehistory from nineteenth-century Belgium. In the study of human prehistory and evolution, material data are either fairly abundant stone tools or very scarce fossil bones. These two types of material data stand for two different strategies in material rhetoric. In this article, the first strategy is exemplified by Aimé Rutot, who gathered great masses of eoliths (crudely chipped stones which he believed to be prehistoric tools). The second strategy is typified by the example of Julien Fraipont, who based his scientific career on only two Neanderthal skeletons. Rutot sent his "artifacts" to a very wide audience, while Fraipont showed his skeletons to only a few selected scholars. Unlike Rutot, however, Fraipont was able to monitor his audience's interpretation of the finds by means of personal contacts. What an archaeologist gains in reach, he or she apparently loses in control. In this article we argue that only those scholars who find the right balance between the extremes of reach and control will prove to be successful.

  14. Water plasticization of extruded material made from meat and bone meal and sodium caseinate.

    Science.gov (United States)

    Garcia, Rafael A; Onwulata, Charles I; Ashby, Richard D

    2004-06-16

    Meat and bone meal (MBM) is a high protein agricultural commodity that currently has few applications other than as an animal feed. Unmodified MBM has poor functional properties, due to its low solubility. Our results from pilot plant trials demonstrate that MBM can be extrusion-processed along with sodium caseinate to produce a useful plastic material. We developed this material for use as a dog chew toy. For this application, elastic modulus (stiffness) is a key characteristic. Our results detail the relationship between ambient relative humidity and equilibrium moisture content (MC) in the material. The influence of MC on the glass transition temperature and elastic modulus reflects the plasticization of this material by water. On the basis of a comparison to a commercially available dog chew, the range of stiffness achievable with our material, 0.25-2.50 GPa, encompasses the values appropriate for a dog chew. Our results show that a particular desired stiffness can be maintained by applying an edible moisture barrier to the surface of the material.

  15. EFFECT OF MAGNESIUM AS SUBSTITUTE MATERIAL IN ENZYME MEDIATED CALCITE PRECIPITATION (EMCP FOR SOIL IMPROVEMENT TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Heriansyah ePutra

    2016-05-01

    Full Text Available The optimization of enzyme-mediated calcite precipitation (EMCP was evaluated as a soil improvement technique. In our previous works, purified urease was utilized to bio-catalyze the hydrolysis of urea, which causes the supplied Ca2+ to precipitate with CO32- as calcium carbonate. In the present work, magnesium chloride was newly added to the injecting solutions to delay the reaction rate and to enhance the amount of carbonate precipitation. Soil specimens were prepared in PVC cylinders and treated with concentration-controlled solutions composed of urea, urease, calcium, and magnesium chloride. The mechanical properties of the treated soil specimens were examined through unconfined compressive strength (UCS tests. A precipitation ratio of the carbonate up to 90% of the maximum theoretical precipitation was achieved by adding a small amount of magnesium chloride. Adding magnesium chloride as a delaying agent was indeed found to reduce the reaction rate of the precipitation, which may increase the volume of the treated soil if used in real fields because of the slower precipitation rate and the resulting higher injectivity. A mineralogical analysis revealed that magnesium chloride decreases the crystal size of the precipitated materials and that another carbonate of aragonite is newly formed. Mechanical test results indicated that carbonate precipitates within the soils and brings about a significant improvement in strength. A maximum UCS of 0.6 MPa was obtained from the treated samples.

  16. [Bovine heterologous bone graft in orbital surgery].

    Science.gov (United States)

    Morax, S; Hurbli, T; Smida, R

    1993-08-01

    Lubboc (T650) is a bovine heterologous bone implant obtained by specific preparation of trabecular of bone. In vitro and in vivo biocompatibility studies have revealed the absence of any cytotoxicity or systemic toxicity. Lubboc has many fields of application, including all bone graft surgical indications. We report our first results concerning the use of this product in orbital surgery either as a filling or contention material or as an apposition material. On all 20 operated patients we did not encounter any intolerance, inflammation or infection. The follow-up is still too short to appreciate the long term integration of this material which has the advantage of being a substitute for autologous bone, avoiding bone graft harvesting.

  17. Changing patterns in the use, recycling, and material substitution of mercury in the United States

    Science.gov (United States)

    Wilburn, David R.

    2013-01-01

    Environmental concerns have led to numerous regulations that have dramatically decreased the reported production and use of mercury in the United States since the 1980s. Government legislation and subsequent industry actions have led to increased collection of mercury-containing materials and the recovery of mercury through recycling. Mercury emissions have been reduced and effective alternatives to mercury products have been developed for many applications. This study updates and quantifies the changes in demand, supply, use, and material flow for mercury in various sectors in the United States that have taken place since 1996. Nearly all primary mercury produced in the United States is derived as a byproduct of processing of gold and silver ore in Nevada. Since 2001, annual production of mercury from gold and silver mining in Nevada has decreased by 22 percent overall because ore from greater depths containing low grade mercury is recovered, and mercury emissions from this source have decreased by 95 percent as a result of increased regulation and improved collection and suppression technology. The distribution of consumption of mercury in the United States has changed as a result of regulation (elimination of large-scale mercury use in the paint and battery sectors), reduction by consumers (decommissioning of mercury-cell chloralkali manufacturing capacity), and technological advances (improvements in dental, lighting, and wiring sectors). Mercury use in the chloralkali sector, the leading end-use sector in the United States in 1996, has declined by 98 percent from 136 metric tons (t) in 1996 to about 0.3 t in 2010 because of increased processing and recycling efficiencies and plant closures or conversion to other technologies. As plants were closed, mercury recovered from the infrastructure of decommissioned plants has been exported, making the United States a net exporter of mercury, even though no mercury has been produced as the primary product from mines in

  18. Characterization of wear in composite material orthopaedic implants. Part II: The implant/bone interface.

    Science.gov (United States)

    Albert, K; Schledjewski, R; Harbaugh, M; Bleser, S; Jamison, R; Friedrich, K

    1994-01-01

    Carbon fiber/PEEK polymer (C/PEEK) composite materials are being developed for use as orthopaedic implant materials. Wear is an issue of increasing importance in orthopaedic implants; particulate debris generated by the wearing of biomaterials may be a causal factor leading to osteolysis and implant loosening. Therefore, numerical and experimental studies were completed to characterize the wear of C/PEEK composite materials in comparison to current orthopaedic implant materials. Finite element analyses (FEA) of a composite material hip stem implanted in a femur and loaded at 890 N determined that peak contact stresses will occur at the proximal-medial and distal regions of the implant. These contact stresses were found to be below 1.0 MPa over most of the implant surface; however the peak stress in the proximal-medial region was 1.8 MPa and higher still at the distal portion of the stem. In vivo forces result in contact stress values up to 9.0 MPa. The composite implant exhibited 10-40% lower contact stresses in the distal region compared to a titanium-alloy implant of identical design. Composite material wear samples were slid against porous hydroxylapatite (HA) to simulate the stem/bone interface. An identical series of experiments was run for comparison to a current orthopaedic implant material--Ti6A14V titanium alloy. Two domains of motion were studied; a composite ring-on-HA disc large amplitude sliding wear test; and a composite pin-on-HA disc small amplitude fretting regimen. Nominal contact pressures during testing were 1.4 MPa and 7.6 MPa for sliding and fretting tests, respectively. Fretting and sliding abrasive wear tests resulted in the composite material exhibiting a lower wear rate than the titanium-alloy. The magnitude of the difference was greatly dependent on the contact pressures, sliding amplitudes, and counterface material properties.

  19. Synthesis and Characterization of Biocomposite BCP/Collagen for Bone Material Scaffold

    Directory of Open Access Journals (Sweden)

    Anjarsari Anjarsari

    2017-02-01

    Full Text Available AbstractBiphasic calcium phosphate (BCP widely used as implants and scaffolds in different orthopedic and dental application. The aim of this study was to determine synthesis and characteristics of biocomposite BCP/collagen as bone scaffold material. BCP/collagen was classified into three groups: 1 BCP/K5 (5% collagen in scaffold, 2 BCP/K10 (10% collagen in scaffold, and 3 BCP/K15 (15% collagen in scaffold. The samples were characterized by Fourier Transform Infrared (FTIR Spectroscopy, and Scanning Electron Microscope (SEM techniques. Overall, concentration of collagen was not significantly different to the spectrum. However, FTIR analysis shows the change intensity in bio-composite BCP/collagen. Collagen intensity Higher concentration when collagen concentration in scaffold higher. Morphology analysis of the scaffold showed significant differences in pore formation. BCP/K15 was showed pores formed in scaffold. Synthesis of composite BCP/collagen does not affect the spectrum of functional groups, but affects the formation of pores in the bone scaffold material.

  20. Artrodese na coluna cervical utilizando SICAP como substituto de enxerto ósseo Artrodesis en la columna cervical utilizando SICAP como sustituto de injerto óseo Cervical spine fusion utilizing silicated calcium phosphate bone graft substitute (SICAP

    Directory of Open Access Journals (Sweden)

    Juliano Fratezi

    2011-01-01

    Tech EE.UU, Reino Unido es un injerto óseo compuesto de calcio-fosfato con una sustitución de silicato en la estructura química, con una estructura tridimensional que parece hueso natural. MÉTODOS: 19 pacientes fueron sometidos a fusión ósea cervical y analizados retrospectivamente. La evaluación radiográfica y la evaluación clínica fueron realizadas utilizandose el cuestionario Neck Disability Index y la escala análoga del dolor (VAS pre y postoperación. RESULTADOS: El período promedio de seguimiento postoperatorio fue de 14 meses ± 5 meses (7-30 meses. Once pacientes fueron sometidos a fusión vía anterior; 5 pacientes vía posterior y 3 pacientes vía anterior y posterior. La revisión radiográfica mostró 19/19 (100% de fusión ósea, ningún caso presentó subsidencia, rotura o soltura de material de implante o movimiento en los niveles fusionados. Ningún ejemplo de osificación heterotópica o de crecimiento óseo intracanal fue observado. Clínicamente, el promedio de las puntuaciones del Neck Disability disminuyeron 13,3 puntos (promedio preop. de 34,5, postop. de 21,2, mejora de 39%, el promedio de VAS para dolor cervical disminuyó 2 puntos (2,7 preop. para 0,7 postop.; mejora de 74,1%. No fueron observadas complicaciones como infección, osteólisis o edema excesivo de las partes blandas. CONCLUSIÓN: Los resultados preliminares obtenidos en esta serie feuron estimulantes con el uso de SICaP como injerto óseo, con sólida fusión ósea obtenida en todos los casos y sin formación de osificación heterotópica o crecimiento de hueso intracanal. SIcaP demuestra ser un sustituto confiable para el injerto óseo autólogo en la columna cervical.OBJECTIVE: Bone graft substitutes have been developed to obviate the need for autograft from the iliac crest and its resultant complications. SiCaP (Actifuse, ApaTech US, UK is a calcium phosphate bone graft substitute with selective controlled silicate substitution in a patented 3-dimensional structure

  1. Synthesis and properties of Pr-substituted MgZn ferrites for core materials and high frequency applications

    Energy Technology Data Exchange (ETDEWEB)

    Mukhtar, Muhammad Waqas; Irfan, Muhammad [Department of Physics, Federal Urdu University of Arts, Science and Technology, Islamabad 44000 (Pakistan); Ahmad, Ishtiaq; Ali, Ihsan [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Akhtar, Majid Niaz [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan); Khan, Muhammad Azhar [Department of Physics, Islamia University, Bahawalpur (Pakistan); Abbas, Ghazanfar [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan); Rana, M.U. [Center of Excellence in Solid State Physics, University of the Punjab, Lahore (Pakistan); Ali, Akbar [Department of Basic Sciences, Riphah International University, Islamabad-44000 (Pakistan); Ahmad, Mukhtar, E-mail: ahmadmr25@yahoo.com [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

    2015-05-01

    A series of single phase spinel ferrites having chemical formula Mg{sub 0.5}Zn{sub 0.5}Pr{sub x}Fe{sub 2−x}O{sub 4} (x=0.00, 0.05, 0.10, 0.15, 0.20, 0.25) were prepared using the sol–gel technique after sintering at 700 °C. The thermal decomposition behavior of an as prepared powder was investigated by means of DTA/TGA analyses. The sintered powders were then characterized by Fourier transform infrared spectroscope, X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscope and vibrating sample magnetometer. X-ray diffraction patterns confirm the single phase spinel structure of prepared ferrites without the presence of any impurity phase. The value of lattice parameter (a) increases with the increase of Pr contents (x) into the spinel lattice. The grain size estimated from electron microscope images is in the range of 2.75–5.4 µm which confirms the spinel crystalline nature of the investigated samples. The saturation magnetization (M{sub s}) decreases whereas coercivity (H{sub c}) increases with the increase of Pr contents (x). The measured parameters suggest that these materials are favorable for high frequency applications and as core materials. - Highlights: • Pr-substituted spinel ferrites synthesized by autocombustion route have been investigated. • The average grain size was in the range of 2.75–5.4 µm estimated by SEM technique. • The (M{sub s}) decreases whereas (H{sub c}) increases with the increase of Pr contents (x). • These parameters are favorable for high frequency applications and as core materials.

  2. Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs

    OpenAIRE

    Jung, R E; Kokovic, V; Jurisic, M; Yaman, D; K. Subramani; Weber, F. E.

    2011-01-01

    Objectives: The aim of the present study was to compare a newly developed biodegradable polylactide/polyglycolide/N-methyl-2-pyrrolidone (PLGA/NMP) membrane with a standard resorbable collagen membrane (RCM) in combination with and without the use of a bone substitute material (deproteinized bovine bone mineral [DBBM]) looking at the proposed tenting effect and bone regeneration. Materials and methods: In five adult German sheepdogs, the mandibular premolars P2, P3, P4, and the molar M1 were ...

  3. Bone response to machined and resorbable blast material titanium implants: an experimental study in rabbits.

    Science.gov (United States)

    Piattelli, Maurizio; Scarano, Antonio; Paolantonio, Michele; Iezzi, Giovanna; Petrone, Giovanna; Piattelli, Adriano

    2002-01-01

    The aim of the present study was a comparison of implants' responses to a machined surface and to a surface sandblasted with hydroxyapatite (HA) particles (resorbable blast material [RBM]). Threaded machined and RBM, grade 3, commercially pure, titanium, screw-shaped inplants were used in this study. Twenty-four New Zealand white mature male rabbits were used. The inplants were inserted into the articular femoral knee joint according to a previously described technique. Each rabbit received 2 inplants, 1 test (RBM) and 1 control (machined). A total of 48 implants (24 control and 24 test) were inserted. The rabbits were anesthetized with intramuscular injections of fluanisone (0.7 mg/ kg body weight) and diazepam (1.5 mg/kg b.wt.), and local anesthesia was given using 1 mL of 2% lidocaine/adrenalin solution. Two rabbits died in the postoperative course. Four animals were euthanatized with an overdose of intravenous pentobarbital after 1, 2, 3, and 4 weeks; 6 rabbits were euthanatized after 8 weeks. A total of 44 implants were retrieved. The specimens were processed with the Precise 1 Automated System to obtain thin ground sections. A total of 3 slides were obtained for each implant. The slides were stained with acid and basic fuchsin and toluidine blue. The slides were observed in normal transmitted light under a Leitz Laborlux microscope, and histomorphometric analysis was performed. With the machined implants, it was possible to observe the presence of bone trabeculae near the implant surface at low magnification. At higher magnification many actively secreting alkaline phosphatasepositive (ALP+) osteoblasts were observed. In many areas, a not yet mineralized matrix was present. After 4 to 8 weeks, mature bone appeared in direct contact with the implant surface, but in many areas a not yet mineralized osteoid matrix was interposed between the mineralized bone and implant surface. In the RBM implants, many ALP+ osteoblasts were present and in direct contact with

  4. Bone regeneration in 3D printing bioactive ceramic scaffolds with improved tissue/material interface pore architecture in thin-wall bone defect.

    Science.gov (United States)

    Shao, Huifeng; Ke, Xiurong; Liu, An; Sun, Miao; He, Yong; Yang, Xianyan; Fu, Jianzhong; Liu, Yanming; Zhang, Lei; Yang, Guojing; Xu, Sanzhong; Gou, Zhongru

    2017-03-13

    Three-dimensional (3D) printing bioactive ceramics have demonstrated alternative approaches to bone tissue repair, but an optimized materials system for improving the recruitment of host osteogenic cells into the bone defect and enhancing targeted repair of the thin-wall craniomaxillofacial defects remains elusive. Herein we systematically evaluated the role of side-wall pore architecture in the direct-ink-writing bioceramic scaffolds on mechanical properties and osteogenic capacity in rabbit calvarial defects. The pure calcium silicate (CSi) and dilute Mg-doped CSi (CSi-Mg6) scaffolds with different layer thickness and macropore sizes were prepared by varying the layer deposition mode from single-layer printing (SLP) to double-layer printing (DLP) and then by undergoing one-, or two-step sintering. It was found that the dilute Mg doping and/or two-step sintering schedule was especially beneficial for improving the compressive strength (~25‒104 MPa) and flexural strength (~6‒18 MPa) of the Ca-silicate scaffolds. The histological analysis for the calvarial bone specimens in vivo revealed that the SLP scaffolds had a high osteoconduction at the early stage (4 weeks) but the DLP scaffolds displayed a higher osteogenic capacity for a long time stage (8~12 weeks). Although the DLP CSi scaffolds displayed somewhat higher osteogenic capacity at 8 and 12 weeks, the DLP CSi-Mg6 scaffolds with excellent fracture resistance also showed appreciable new bone tissue ingrowth. These findings demonstrate that the side-wall pore architecture in 3D printed bioceramic scaffolds is required to optimize for bone repair in calvarial bone defects, and especially the Mg doping wollastontie is promising for 3D printing thin-wall porous scaffolds for craniomaxillofacial bone defect treatment.

  5. Development of a strain rate dependent material model of human cortical bone for computer-aided reconstruction of injury mechanisms.

    Science.gov (United States)

    Asgharpour, Zahra; Zioupos, Peter; Graw, Matthias; Peldschus, Steffen

    2014-03-01

    Computer-aided methods such as finite-element simulation offer a great potential in the forensic reconstruction of injury mechanisms. Numerous studies have been performed on understanding and analysing the mechanical properties of bone and the mechanism of its fracture. Determination of the mechanical properties of bones is made on the same basis used for other structural materials. The mechanical behaviour of bones is affected by the mechanical properties of the bone material, the geometry, the loading direction and mode and of course the loading rate. Strain rate dependency of mechanical properties of cortical bone has been well demonstrated in literature studies, but as many of these were performed on animal bones and at non-physiological strain rates it is questionable how these will apply in the human situations. High strain-rates dominate in a lot of forensic applications in automotive crashes and assault scenarios. There is an overwhelming need to a model which can describe the complex behaviour of bone at lower strain rates as well as higher ones. Some attempts have been made to model the viscoelastic and viscoplastic properties of the bone at high strain rates using constitutive mathematical models with little demonstrated success. The main objective of the present study is to model the rate dependent behaviour of the bones based on experimental data. An isotropic material model of human cortical bone with strain rate dependency effects is implemented using the LS-DYNA material library. We employed a human finite element model called THUMS (Total Human Model for Safety), developed by Toyota R&D Labs and the Wayne State University, USA. The finite element model of the human femur is extracted from the THUMS model. Different methods have been employed to develop a strain rate dependent material model for the femur bone. Results of one the recent experimental studies on human femur have been employed to obtain the numerical model for cortical femur. A

  6. Quantifying trabecular bone material anisotropy and orientation using low resolution clinical CT images: A feasibility study.

    Science.gov (United States)

    Nazemi, S Majid; Cooper, David M L; Johnston, James D

    2016-09-01

    Accounting for spatial variation of trabecular material anisotropy and orientation can improve the accuracy of quantitative computed tomography-based finite element (FE) modeling of bone. The objective of this study was to investigate the feasibility of quantifying trabecular material anisotropy and orientation using clinical computed tomography (CT). Forty four cubic volumes of interest were obtained from micro-CT images of the human radius. Micro-FE modeling was performed on the samples to obtain orthotropic stiffness entries as well as trabecular orientation. Simulated computed tomography images (0.32, 0.37, and 0.5mm isotropic voxel sizes) were created by resampling micro-CT images with added image noise. The gray-level structure tensor was used to derive fabric eigenvalues and eigenvectors in simulated CT images. For 'best case' comparison purposes, Mean Intercept Length was used to define fabric from micro-CT images. Regression was used in combination with eigenvalues, imaged density and FE to inversely derive the constants used in Cowin and Zysset-Curnier fabric-elasticity equations, and for comparing image derived fabric-elasticity stiffness entries to those obtained using micro-FE. Image derived eigenvectors (which indicated trabecular orientation) were then compared to orientation derived using micro-FE. When using clinically available voxel sizes, gray-level structure tensor derived fabric combined with Cowin's equations was able to explain 94-97% of the variance in orthotropic stiffness entries while Zysset-Curnier equations explained 82-88% of the variance in stiffness. Image derived orientation deviated by 4.4-10.8° from micro-FE derived orientation. Our results indicate potential to account for spatial variation of trabecular material anisotropy and orientation in subject-specific finite element modeling of bone using clinically available CT.

  7. P(3HB Based Magnetic Nanocomposites: Smart Materials for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Everest Akaraonye

    2016-01-01

    Full Text Available The objective of this work was to investigate the potential application of Poly(3-hydroxybutyrate/magnetic nanoparticles, P(3HB/MNP, and Poly(3-hydroxybutyrate/ferrofluid (P(3HB/FF nanocomposites as a smart material for bone tissue repair. The composite films, produced using conventional solvent casting technique, exhibited a good uniform dispersion of magnetic nanoparticles and ferrofluid and their aggregates within the P(3HB matrix. The result of the static test performed on the samples showed that there was a 277% and 327% increase in Young’s modulus of the composite due to the incorporation of MNP and ferrofluid, respectively. The storage modulus of the P(3HBMNP and P(3HB/FF was found to have increased to 186% and 103%, respectively, when compared to neat P(3HB. The introduction of MNP and ferrofluid positively increased the crystallinity of the composite scaffolds which has been suggested to be useful in bone regeneration. The total amount of protein absorbed by the P(3HB/MNP and P(3HB/FF composite scaffolds also increased by 91% and 83%, respectively, with respect to neat P(3HB. Cell attachment and proliferation were found to be optimal on the P(HB/MNP and P(3HB/FF composites compared to the tissue culture plate (TCP and neat P(3HB, indicating a highly compatible surface for the adhesion and proliferation of the MG-63 cells. Overall, this work confirmed the potential of using P(3HB/MNP and P(3HB/FF composite scaffolds in bone tissue engineering.

  8. Development of efficient electron beam irradiating condition of artificial bone substitutes with 7 to 3 ratio of hydroxyapatite, tricalcium phosphate and type I collagen to maximize bony regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soung Min; Eo, Mi Young; Myoung, Hoon; Kang, Ji Young; Lee, Jong Ho [Seoul National Univ., Seoul (Korea, Republic of); Cho, Hye Jin [Korea Basic Science Institute, Daejeon (Korea, Republic of); Yea, Kwon Hae; Lee, Byungcheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-07-01

    Bony defects in oral and maxillofacial region was a common problem -Auto graft -Allograft -Xenograft. Accenting bone is 'Gold standard' for bone defect repair and from the rib, iliac crest, jaw and tibia. Bone is 70% inorganic components -which provide firmness, and approx. and 30% organic substances.

  9. Lathyrism-induced alterations in collagen cross-links influence the mechanical properties of bone material without affecting the mineral

    Science.gov (United States)

    Paschalis, E.P.; Tatakis, D.N.; Robins, S.; Fratzl, P.; Manjubala, I.; Zoehrer, R.; Gamsjaeger, S.; Buchinger, B.; Roschger, A.; Phipps, R.; Boskey, A.L.; Dall'Ara, E.; Varga, P.; Zysset, P.; Klaushofer, K.; Roschger, P.

    2011-01-01

    In the present study a rat animal model of lathyrism was employed to decipher whether anatomically confined alterations in collagen cross-links are sufficient to influence the mechanical properties of whole bone. Animal experiments were performed under an ethics committee approved protocol. Sixty-four female (47 day old) rats of equivalent weights were divided into four groups (16 per group): Controls were fed a semi-synthetic diet containing 0.6% calcium and 0.6% phosphorus for 2 or 4 weeks and β-APN treated animals were fed additionally with β-aminopropionitrile (0.1% dry weight). At the end of this period the rats in the four groups were sacrificed, and L2–L6 vertebra were collected. Collagen cross-links were determined by both biochemical and spectroscopic (Fourier transform infrared imaging (FTIRI)) analyses. Mineral content and distribution (BMDD) were determined by quantitative backscattered electron imaging (qBEI), and mineral maturity/crystallinity by FTIRI techniques. Micro-CT was used to describe the architectural properties. Mechanical performance of whole bone as well as of bone matrix material was tested by vertebral compression tests and by nano-indentation, respectively. The data of the present study indicate that β-APN treatment changed whole vertebra properties compared to non-treated rats, including collagen cross-links pattern, trabecular bone volume to tissue ratio and trabecular thickness, which were all decreased (p < 0.05). Further, compression tests revealed a significant negative impact of β-APN treatment on maximal force to failure and energy to failure, while stiffness was not influenced. Bone mineral density distribution (BMDD) was not altered either. At the material level, β-APN treated rats exhibited increased Pyd/Divalent cross-link ratios in areas confined to a newly formed bone. Moreover, nano-indentation experiments showed that the E-modulus and hardness were reduced only in newly formed bone areas under the influence

  10. The sealing ability of novel Kryptonite adhesive bone cement as a retrograde filling material

    Science.gov (United States)

    Uzun, İsmail; Keskin, Cangül; Güler, Buğra

    2016-01-01

    Background. This study evaluated the ability of Kryptonite bone cement in sealing retrograde cavities. Methods. The root canals of one hundred extracted human maxillary incisor teeth were instrumented up to master apical file #40 using Mtwo rotary system and obturated with gutta-percha and AHPlus sealer by cold lateral compaction method. The specimens were assigned to one control group and four experimental groups based on the retrograde filling materials (n=20). The specimens were immersed in 0.5% Rhodamine B solution for 48h. Then the specimens were divided longitudinally into two parts and the depth of dye penetration was assessed under ×10 magnification. Data were analyzed using one-way ANOVA and Bonferroni tests. Results. There were statistically significant difference between the experimental groups and the control group (P0.05). Conclusion. Kryptonite cement provided optimal apical seal in a manner similar to MTA, amalgam and IRM when used as a retrograde filling cement. PMID:27651886

  11. Advanced bioimaging technologies in assessment of the quality of bone and scaffold materials. Techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Qin Ling; Leung, Kwok Sui (eds.) [Chinese Univ. of Hong Kong (China). Dept. of Orthopaedics and Traumatology; Genant, H.K. [California Univ., San Francisco, CA (United States); Griffith, J.F. [Chinese Univ. of Hong Kong (China). Dept. of Radiology and Organ Imaging

    2007-07-01

    This book provides a perspective on the current status of bioimaging technologies developed to assess the quality of musculoskeletal tissue with an emphasis on bone and cartilage. It offers evaluations of scaffold biomaterials developed for enhancing the repair of musculoskeletal tissues. These bioimaging techniques include micro-CT, nano-CT, pQCT/QCT, MRI, and ultrasound, which provide not only 2-D and 3-D images of the related organs or tissues, but also quantifications of the relevant parameters. The advance bioimaging technologies developed for the above applications are also extended by incorporating imaging contrast-enhancement materials. Thus, this book will provide a unique platform for multidisciplinary collaborations in education and joint R and D among various professions, including biomedical engineering, biomaterials, and basic and clinical medicine. (orig.)

  12. Guided bone regeneration for immediate non-submerged implant placement using bioabsorbable materials in Beagle dogs.

    Science.gov (United States)

    Brunel, G; Benqué, E; Elharar, F; Sansac, C; Duffort, J F; Barthet, P; Baysse, E; Miller, N

    1998-10-01

    The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri-implant defects after placement of non-submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow-screw non-submerged dental implants. For each animal, the coronal peri-implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site; 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures (P > 0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%, P < 0.05) or sites grafted with HA (22.2%, P < 0.02). Total BIC in sites treated with the HA-membrane combination (43%) was only significantly different from sites treated with HA (P < 0.05). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.

  13. Phantom-less bone mineral density (BMD) measurement using dual energy computed tomography-based 3-material decomposition

    Science.gov (United States)

    Hofmann, Philipp; Sedlmair, Martin; Krauss, Bernhard; Wichmann, Julian L.; Bauer, Ralf W.; Flohr, Thomas G.; Mahnken, Andreas H.

    2016-03-01

    Osteoporosis is a degenerative bone disease usually diagnosed at the manifestation of fragility fractures, which severely endanger the health of especially the elderly. To ensure timely therapeutic countermeasures, noninvasive and widely applicable diagnostic methods are required. Currently the primary quantifiable indicator for bone stability, bone mineral density (BMD), is obtained either by DEXA (Dual-energy X-ray absorptiometry) or qCT (quantitative CT). Both have respective advantages and disadvantages, with DEXA being considered as gold standard. For timely diagnosis of osteoporosis, another CT-based method is presented. A Dual Energy CT reconstruction workflow is being developed to evaluate BMD by evaluating lumbar spine (L1-L4) DE-CT images. The workflow is ROI-based and automated for practical use. A dual energy 3-material decomposition algorithm is used to differentiate bone from soft tissue and fat attenuation. The algorithm uses material attenuation coefficients on different beam energy levels. The bone fraction of the three different tissues is used to calculate the amount of hydroxylapatite in the trabecular bone of the corpus vertebrae inside a predefined ROI. Calibrations have been performed to obtain volumetric bone mineral density (vBMD) without having to add a calibration phantom or to use special scan protocols or hardware. Accuracy and precision are dependent on image noise and comparable to qCT images. Clinical indications are in accordance with the DEXA gold standard. The decomposition-based workflow shows bone degradation effects normally not visible on standard CT images which would induce errors in normal qCT results.

  14. Effects of Na-substitution on structural and electronic properties of Li2CoSiO4 cathode material

    Institute of Scientific and Technical Information of China (English)

    WU Shun-qing; ZHU Zi-zhong; YANG Yong; HOU Zhu-feng

    2009-01-01

    Na-substituted dilithium orthosilicate Li2CoSiO4 was investigated by performing density functional theory calculations within the GGA+U framework. The effects of Na-substitution on the electronic structures and structural properties of Li2CoSiO4 were presented. The results show that the Na-substitution on Li sites in Li2CoSiO4 induces a lowering of the conduction bands and a narrowing of the band gap, which could be helpful for enhancing the electronic conductivity. On the other hand, the Na-substitution on the Li ions in Li2CoSiO4 leads to the expansion of interlayer space of the adjacent corrugated layers. This lattice expansion effect would benefit the Li ion diffusion.

  15. Examining the diagenetic alteration of human bone material from a range of archaeological burial sites using nuclear microscopy

    Science.gov (United States)

    Elliott, T. A.; Grime, G. W.

    1993-05-01

    The inorganic analysis of archaeological bone material can potentially provide a wealth of information about the chronology, diet and palaeoenvironment of past populations: for example, strontium and uranium levels are used in palaeodietary and dating studies, respectively. However, the extent to which the chemical composition of bone is subject to diagenetic change during burial is open to controversy due, in part, to differences in analytical technique, bone types and burial conditions. To investigate this problem, archaeological human bone material from a number of different geological environments including Pompeii and a 12th century British ecclesiastical site, together with material from two seawater burials (The "Mary Rose" and a 6th century Mediterranean wreck) have been studied using the nuclear microprobe facility at the University of Oxford. Results using microbeam PIXE show that bone is subject to contamination from a wide range of trace elements depending on the burial conditions. Elemental maps are presented to demonstrate the distribution of trace element accumulation under different burial conditions, and the significance of this work to future trace element studies is discussed.

  16. Augmentation of Bone Tunnel Healing in Anterior Cruciate Ligament Grafts: Application of Calcium Phosphates and Other Materials

    Directory of Open Access Journals (Sweden)

    F. R. Baxter

    2010-01-01

    Full Text Available Bone tunnel healing is an important consideration after anterior cruciate ligament (ACL replacement surgery. Recently, a variety of materials have been proposed for improving this healing process, including autologous bone tissue, cells, artificial proteins, and calcium salts. Amongst these materials are calcium phosphates (CaPs, which are known for their biocompatibility and are widely commercially available. As with the majority of the materials investigated, CaPs have been shown to advance the healing of bone tunnel tissue in animal studies. Mechanical testing shows fixation strengths to be improved, particularly by the application of CaP-based cement in the bone tunnel. Significantly, CaP-based cements have been shown to produce improvements comparable to those induced by potentially more complex treatments such as biologics (including fibronectin and chitin and cultured cells. Further investigation of CaP-based treatment in the bone tunnels during ACL replacement is therefore warranted in order to establish what improvements in healing and resulting clinical benefits may be achieved through its application.

  17. PMMA-hydroxyapatite composite material retards fatigue failure of augmented bone compared to augmentation with plain PMMA: in vivo study using a sheep model.

    Science.gov (United States)

    Arabmotlagh, Mohammad; Bachmaier, Samuel; Geiger, Florian; Rauschmann, Michael

    2014-11-01

    Polymethylmethacrylate (PMMA) is the most commonly used void filler for augmentation of osteoporotic vertebral fracture, but the differing mechanical features of PMMA and osteoporotic bone result in overload and failure of adjacent bone. The aim of this study was to compare fatigue failure of bone after augmentation with PMMA-nanocrystalline hydroxyapatite (HA) composite material or with plain PMMA in a sheep model. After characterization of the mechanical properties of a composite material consisting of PMMA and defined amounts (10, 20, and 30% volume fraction) of HA, the composite material with 30% volume fraction HA was implanted in one distal femur of sheep; plain PMMA was implanted in the other femur. Native non-augmented bone served as control. Three and 6 months after implantation, the augmented bone samples were exposed to cyclic loading and the evolution of damage was investigated. The fatigue life was highest for the ovine native bone and lowest for bone-PMMA specimens. Bone-composite specimens showed significantly higher fatigue life than the respective bone-PMMA specimens in both 3- and 6-month follow-up groups. These results suggest that modification of mechanical properties of PMMA by addition of HA to approximate those of cancellous bone retards fatigue failure of the surrounding bone compared to augmented bone with plain PMMA.

  18. Materials compatibility and lubricants research on CFC-refrigerant substitutes. Quarterly MCLR program technical progress report, January 1, 1995--March 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Szymurski, S.R.; Hourahan, G.C.; Godwin, D.S.

    1995-04-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. The Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) manages and contracts multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each subcontractor.

  19. The effect of permanent grafting materials on the preservation of the buccal bone plate after tooth extraction: an experimental study in the dog.

    LENUS (Irish Health Repository)

    Bashara, Haitham

    2012-08-01

    The aim of the present study was to evaluate the effects of a novel bone substitute system (Natix(®)), consisting of porous titanium granules (PTG) and a bovine-derived xenograft (Bio-Oss(®)), on hard tissue remodelling following their placement into fresh extraction sockets in dogs.

  20. The bone regenerative effect of platelet-rich plasma in combination with an osteoconductive material in rat cranial defects.

    NARCIS (Netherlands)

    Plachokova, A.S.; Dolder, J. van den; Stoelinga, P.J.W.; Jansen, J.A.

    2006-01-01

    The effect of platelet-rich plasma (PRP) on bone regeneration, in combination with an osteoconductive material, was evaluated in a rat model. Cranial defects, 6.2 mm in diameter, were filled with HA/beta-TCP particles, HA/beta-TCP particles combined with PRP and HA/beta-TCP particles combined with P

  1. Mechanical and material properties of cortical and trabecular bone from cannabinoid receptor-1-null (Cnr1(-/-)) mice.

    Science.gov (United States)

    Khalid, Aysha B; Goodyear, Simon R; Ross, Ruth A; Aspden, Richard M

    2016-10-01

    The endocannabinoid system is known for its regulatory effects on bone metabolism through the cannabinoid receptors, Cnr1 and Cnr2. In this study we analysed the mechanical and material properties of long bones from Cnr1(-/-) mice on a C57BL/6 background. Tibiae and femora from 5- and 12-week-old mice were subjected to three-point bending to measure bending stiffness and yield strength. Elastic modulus, density and mineral content were measured in the diaphysis. Second moment of area (MOA2), inner and outer perimeters of the cortical shaft and trabecular fractional bone volume (BV/TV) were measured using micro-CT. In Cnr1(-/-) males and females at both ages the bending stiffness was reduced due to a smaller MOA2. Bone from Cnr1(-/-) females had a greater modulus than wild-type controls, although no differences were observed in males. BV/TV of 12-week-old Cnr1(-/-) females was greater than controls, although no difference was seen at 5-weeks. On the contrary, Cnr1(-/-) males had the same BV/TV as controls at 12-weeks while they had significantly lower values at 5-weeks. This study shows that deleting Cnr1 decreases the amount of cortical bone in both males and females at 12-weeks, but increases the amount of trabecular bone only in females.

  2. Carboxymethyl cellulose-hydroxyapatite hybrid hydrogel as a composite material for bone tissue engineering applications.

    Science.gov (United States)

    Pasqui, Daniela; Torricelli, Paola; De Cagna, Milena; Fini, Milena; Barbucci, Rolando

    2014-05-01

    Natural bone is a complex inorganic-organic nanocomposite material, in which hydroxyapatite (HA) nanocrystals and collagen fibrils are well organized into hierarchical architecture over several length scales. In this work, we reported a new hybrid material (CMC-HA) containing HA drown in a carboxymethylcellulose (CMC)-based hydrogel. The strategy for inserting HA nanocrystals within the hydrogel matrix consists of making the freeze-dried hydrogel to swell in a solution containing HA microcrystals. The composite CMC-HA hydrogel has been characterized from a physicochemical and morphological point of view by means of FTIR spectroscopy, rheological measurements, and field emission scanning electron microscopy (FESEM). No release of HA was measured in water or NaCl solution. The distribution of HA crystal on the surface and inside the hydrogel was determined by time of flight secondary ion mass spectrometry (ToF-SIMS) and FESEM. The biological performance of CMC-HA hydrogel were tested by using osteoblast MG63 line and compared with a CMC-based hydrogel without HA. The evaluation of osteoblast markers and gene expression showed that the addition of HA to CMC hydrogel enhanced cell proliferation and metabolic activity and promoted the production of mineralized extracellular matrix.

  3. Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants.

    Science.gov (United States)

    Gryshkov, Oleksandr; Klyui, Nickolai I; Temchenko, Volodymyr P; Kyselov, Vitalii S; Chatterjee, Anamika; Belyaev, Alexander E; Lauterboeck, Lothar; Iarmolenko, Dmytro; Glasmacher, Birgit

    2016-11-01

    Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO2) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO2 using effective gas detonation deposition approach (GDD). The surface morphology and cytotoxicity of SiC ceramics as well as phase composition and crystallinity of deposited coatings were analyzed. It has been shown that the porosity and pore size of SiC ceramics depend on initial wood source. The XRD and FTIR studies revealed the preservation of crystal structure and phase composition of in the HA coating, while addition of ZrO2 to the initial HA powder resulted in significant decomposition of the final HA/ZrO2 coating and formation of other calcium phosphate phases. In turn, NIH 3T3 cells cultured in medium exposed to coated and uncoated SiC ceramics showed high re-cultivation efficiency as well as metabolic activity. The recultivation efficiency of cells was the highest for HA-coated ceramics, whereas HA/ZrO2 coating improved the recultivation efficiency of cells as compared to uncoated SiC ceramics. The GDD method allowed generating homogeneous HA coatings with no change in calcium to phosphorus ratio. In summary, porous and cytocompatible bio-SiC ceramics with bioactive coatings show a great promise in construction of light, robust, inexpensive and patient-specific bone implants for clinical application.

  4. Novel intramedullary-fixation technique for long bone fragility fractures using bioresorbable materials.

    Directory of Open Access Journals (Sweden)

    Takanobu Nishizuka

    Full Text Available Almost all of the currently available fracture fixation devices for metaphyseal fragility fractures are made of hard metals, which carry a high risk of implant-related complications such as implant cutout in severely osteoporotic patients. We developed a novel fracture fixation technique (intramedullary-fixation with biodegradable materials; IM-BM for severely weakened long bones using three different non-metallic biomaterials, a poly(l-lactide (PLLA woven tube, a nonwoven polyhydroxyalkanoates (PHA fiber mat, and an injectable calcium phosphate cement (CPC. The purpose of this work was to evaluate the feasibility of IM-BM with mechanical testing as well as with an animal experiment. To perform mechanical testing, we fixed two longitudinal acrylic pipes with four different methods, and used them for a three-point bending test (N = 5. The three-point bending test revealed that the average fracture energy for the IM-BM group (PLLA + CPC + PHA was 3 times greater than that of PLLA + CPC group, and 60 to 200 times greater than that of CPC + PHA group and CPC group. Using an osteoporotic rabbit distal femur incomplete fracture model, sixteen rabbits were randomly allocated into four experimental groups (IM-BM group, PLLA + CPC group, CPC group, Kirschner wire (K-wire group. No rabbit in the IM-BM group suffered fracture displacement even under full weight bearing. In contrast, two rabbits in the PLLA + CPC group, three rabbits in the CPC group, and three rabbits in the K-wire group suffered fracture displacement within the first postoperative week. The present work demonstrated that IM-BM was strong enough to reinforce and stabilize incomplete fractures with both mechanical testing and an animal experiment even in the distal thigh, where bone is exposed to the highest bending and torsional stresses in the body. IM-BM can be one treatment option for those with severe osteoporosis.

  5. Development of Magnesium and Siloxane-containing Vaterite and its Composite Materials for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Shinya eYamada

    2015-12-01

    Full Text Available Development of novel biomaterials with Mg2+, Ca2+ and silicate ions releasability for bone regeneration is now in progress. Several inorganic ions have been reported to stimulate bone-forming cells. We featured Ca2+, silicate and especially Mg2+ ions as growth factors for osteoblasts. Various biomaterials, such as ceramic powders and organic-inorganic composites, releasing the ions have been developed and investigated in their cytocompatibilities in our previous work. Through the investigation, providing the three ions was found to be effective to activate osteogenic cells. Mg and siloxane-containing vaterite (MgSiV was prepared by a carbonation process as an inorganic particles, which can provide simultaneously releasing ability of Ca2+, silicate and Mg2+ ions to biodegradable polymers. Poly(L-lactic acid (PLLA- and bioactive PLLA-based composites containing vaterite coatings were discussed on their degradability and cytocompatibility using a metallic Mg substrate as Mg2+ ion source. PLLA/SiV composite film, which has a releasability of silicate ions besides Ca2+ ion, was coated on a pure Mg substrate to be compared with the PLLA/V coating. The degradability and releasability of inorganic ions were morphologically and quantitatively monitored in a cell culture medium. The bonding strength between the coatings and Mg substrates was one of the key factors to control Mg2+ ion release from the substrates. The cell culture tests were conducted using mouse osteoblast-like cells (MC3T3-E1 cells; cellular morphology, proliferation and differentiation on the materials were evaluated. The PLLA/V and PLLA/SiV coatings on Mg substrates were found to enhance the proliferation; especially the PLLA/SiV coating possessed a higher ability of inducing the osteogenic differentiation of the cells.

  6. Novel naturally crosslinked electrospun nanofibrous chitosan mats for guided bone regeneration membranes: material characterization and cytocompatibility.

    Science.gov (United States)

    Norowski, Peter A; Fujiwara, Tomoko; Clem, William C; Adatrow, Pradeep C; Eckstein, Eugene C; Haggard, Warren O; Bumgardner, Joel D

    2015-05-01

    Guided bone regeneration (GBR) barrier membranes are used to prevent soft tissue infiltration into the graft space during dental procedures that involve bone grafting. Chitosan materials have shown promise as GBR barrier membranes, due to their biocompatibility and predictable biodegradability, but degradation rates may still be too high for clinical applications. In this study, chitosan GBR membranes were electrospun using chitosan (70% deacetylated, 312 kDa, 5.5 w/v%), with or without the addition of 5 or 10 mm genipin, a natural crosslinking agent, in order to extend the degradation to meet the clinical target time frame of 4-6 months. Membranes were evaluated for fibre diameter, tensile strength, biodegradation rate, bond structure and cytocompatibility. Genipin addition, at 5 or 10 mm, resulted in median fibre diameters 184, 144 and 154 nm for uncrosslinked, 5 mm and 10 mm crosslinked, respectively. Crosslinking, examined by Fourier transform infrared spectroscopy, showed a decrease in N-H stretch as genipin levels were increased. Genipin-crosslinked mats exhibited only 22% degradation based on mass loss, as compared to 34% for uncrosslinked mats at 16 weeks in vitro. The ultimate tensile strength of the mats was increased by 165% to 32 MPa with 10 mm crosslinking as compared to the uncrosslinked mats. Finally, genipin-crosslinked mats supported the proliferation of SAOS-2 cells in a 5 day growth study, similar to uncrosslinked mats. These results suggest that electrospun chitosan mats may benefit from genipin crosslinking and have the potential to meet clinical degradation time frames for GBR applications.

  7. Microscale Material Properties of Bone and the Mineralized Tissues of the Intervertebral Disc-Vertebral Body Interface

    Science.gov (United States)

    Paietta, Rachel C.

    The objective of this dissertation is to understand the influences of material structure on the properties, function and failure of biological connective tissues. Biological interfaces are becoming an increasingly studied system within mechanics and tissue engineering as a model for attaching dissimilar materials. The elastic modulus of bone (≈ 20 GPa) and cartilage (≈ 0.1-1 MPa) differ over orders of magnitude, which should intuitively create high stress concentrations and failure at the interface. Yet, these natural interface systems rarely fail in vivo, and the mechanism by which loads are transferred between tissues has not yet been established. Tissue quality is one major contributor to the mechanical behavior of bone and cartilage, and is defined by properties such as collagen orientation, mineral volume fraction, porosity and tissue geometry. These properties have yet to be established at the bone-cartilage interface in the spine, and the lack of quantitative data on material microstructure and behavior limits treatments and tissue engineering construct design. In this dissertation, second harmonic generation imaging, quantitative backscattered scanning electron imaging and nanoindentation are combined to characterize micrometer scale tissue quality and modulus in both bone and calcified cartilage. These techniques are utilized to: 1) determine the hierarchical micrometer to millimeter scale properties of lamellar bone, 2) quantify changes throughout development and aging at the human intervertebral disc-vertebral body junction, and 3) explore compressive fractures at this interface. This work is the first to provide quantitative data on the mineral volume fraction, collagen orientation and modulus from the same, undecalcified sections of tissue to corroborate tissue structure and mineralization and describe quantitative parameters of the interface. The principal findings from this work indicate that the underlying matrix, or collagen, organization in

  8. Evaluation of bone regenerative capacity in rats claverial bone defect using platelet rich fibrin with and without beta tri calcium phosphate bone graft material

    Directory of Open Access Journals (Sweden)

    Walid Ahmed Abdullah

    2016-07-01

    Conclusion: The addition of β-TCP to PRF significantly improved bone regeneration in the first 2 weeks after surgery. Although the differences between results with and without the addition of β-TCP to PRF were statistically insignificant from weeks 3 to 6, it was nevertheless apparent that the group receiving the combination showed better results. We suggest a synergistic mechanism for this effect.

  9. Compound soft regenerated skull material for repairing dog skull defects using bone morphogenetic protein as an inductor and nanohydroxyapatite as a scaffold

    Institute of Scientific and Technical Information of China (English)

    Zhidong Shi; Mingwang Liu; Zhongzong Qin; Qinmei Wang; Ying Guo; Haiyong He; Zhonghe Yu

    2008-01-01

    BACKGROUND: In previous studies of skull defects and regeneration, bone morphogenetic protein as an inductor and nanohydroxyapatite as a scaffold have been cocultured with osteoblasts.OBJECTIVE: To verify the characteristics of the new skull regenerated material after compound soft regenerated skull material implantatiom.DESIGN, TIME AND SETTING: The self-control and inter-group control animal experiment was perfurmed at the Sun Yat-sen University, China from February to July 2007.MATERIALS: Twenty-tour healthy adult dogs of both genders weighing 15-20 kg were used in this study. Nanohydroxyapatite as a scaffold was cocultured with osteoblasts. Using demineralized canine bone matrix as a carrier, recombinant human bone morphogenetic protein-2 was employed to prepare compound soft regenerated skull material. Self-designed compound soft regenerated skull material was implanted in models of skull defects.METHODS: Animals were randomly assigned into two groups, Group A (n = 16) and Group B (n = 8).Bilateral 2.5-cm-diameter full-thickness parietal skull defects were made in all animals. In Group A, the right side was reconstructed with calcium alginate gel, osteoblasts, and nanomcter bone meal composite;the left side was reconstructed with calcium alginate gel, osteoblasts, nanometer bone meal and recombinant human bone morphogenetic protein-2 composite. In Group B, the right side was kept as a simple skull detect, and the left side was reconstructed with calcium alginate gel, osteoblasts, nanometer bone meal and recombinant human bone morphogenetic protein-2 composite.MAIN OUTCOME MEASURES: Bone regeneration and histopathological changes at the site of the skull defect were observed with an optical microscope and a scanning electron microscope after surgery.The ability to form bone was measured by alizarin red S staining. In vitro cultured osteoblasts were observed for morphology.RESULTS: One month following surgery, newly formed bone trabeculae mostly covered the

  10. The role of synthetic biomaterials in resorptive alveolar bone regeneration

    Directory of Open Access Journals (Sweden)

    Kaličanin Biljana M.

    2007-01-01

    Full Text Available The alveolar bone tissue resorption defect has a significant role in dentistry. Because of the bone tissue deficit developed by alveolar resorption, the use of synthetic material CP/PLGA (calcium-phosphate/polylactide-co-gliycolide composite was introduced. Investigations were performed on rats with artificially produced resorption of the mandibular bone. The results show that the best effect on alveolar bone were attained by using nano-composite implants. The effect of the nanocomposite was ascertained by determining the calcium and phosphate content, as a basis of the hydroxyapatite structure. The results show that synthetic CP/PLGA nanocomposite alleviate the rehabilitation of weakened alveolar bone. Due to its osteoconductive effect, CP/PLGA can be the material of choice for bone substitution in the future.

  11. Effects of deleting cannabinoid receptor-2 on mechanical and material properties of cortical and trabecular bone

    Directory of Open Access Journals (Sweden)

    Aysha B. Khalid

    2015-12-01

    Full Text Available Cnr2 is one of two cannabinoid receptors known to regulate bone metabolism. Here, we compared the whole bone properties of femora and tibiae from three-month-old Cnr2−/- mice with wild-type controls using a C57BL/6 background. Bending stiffness was measured by three-point bending. The elastic modulus, density and mineral content were measured using ultrasound, Archimedes’ principle and ashing. Micro-CT was used to measure the second moment of area, inner and outer perimeters of the cortical shaft and trabecular parameters. Deleting Cnr2 increased the bending stiffness by increasing the second moment of area. Bone from affected male mice had a greater modulus than controls, although no difference was observed in females. The fractional volume of trabecular bone was greater in Cnr2−/- females than controls, while no difference was seen in males. These data indicate that inactivating Cnr2 increases the amount of cortical bone in both males and females at 3 months of age, but the effect on trabecular bone is different in the two sexes. These findings extend previous studies looking only at trabecular bone and provide further support for the possible use of Cnr2 antagonists for improving bone properties that may be of value in the treatment of bone disorders.

  12. Histomorphometric analysis of newly formed bone after bilateral maxillary sinus augmentation using two different osteoconductive materials and internal collagen membrane.

    Science.gov (United States)

    Kolerman, Roni; Samorodnitzky-Naveh, Gili R; Barnea, Eitan; Tal, Haim

    2012-02-01

    Deproteinized bovine bone mineral (DBBM) and human freeze-dried bone allograft (FDBA) were compared in five patients undergoing bilateral maxillary sinus floor augmentation using DBBM on one side and FDBA on the contralateral side. After 9 months, core biopsy specimens were harvested. Mean newly formed bone values were 31.8% and 27.2% at FDBA and DBBM sites, respectively (P = .451); mean residual graft particle values were 21.5% and 24.2%, respectively (P = .619); and mean connective tissue values were 46.7% and 48.6%, respectively (P = .566). Within the limits of the present study, it is suggested that both graft materials are equally suitable for sinus augmentation.

  13. Osteogenesis and cytotoxicity of a new Carbon Fiber/Flax/Epoxy composite material for bone fracture plate applications.

    Science.gov (United States)

    Bagheri, Zahra S; Giles, Erica; El Sawi, Ihab; Amleh, Asma; Schemitsch, Emil H; Zdero, Radovan; Bougherara, Habiba

    2015-01-01

    This study is part of an ongoing program to develop a new CF/Flax/Epoxy bone fracture plate to be used in orthopedic trauma applications. The purpose was to determine this new plate's in-vitro effects on the level of bone formation genes, as well as cell viability in comparison with a medical grade metal (i.e. stainless steel) commonly employed for fabrication of bone plates (positive control). Cytotoxicity and osteogenesis induced by wear debris of the material were assessed using Methyl Tetrazolium (MTT) assay and reverse transcription polymerase chain reaction (RT-PCR) for 3 osteogenesis specific gene markers, including bone morphogenetic proteins (BMP2), runt-related transcription factor 2 (Runx2) and Osterix. Moreover, the Flax/Epoxy and CF/Epoxy composites were examined separately for their wettability properties by water absorption and contact angle (CA) tests using the sessile drop technique. The MTT results for indirect and direct assays indicated that the CF/Flax/Epoxy composite material showed comparable cell viability with no cytotoxicity at all incubation times to that of the metal group (p≥0.05). Osteogenesis test results showed that the expression level of Runx2 marker induced by CF/Flax/Epoxy were significantly higher than those induced by metal after 48 h (p=0.57). Also, the Flax/Epoxy composite revealed a hydrophilic character (CA=68.07°±2.05°) and absorbed more water up to 17.2% compared to CF/Epoxy, which reached 1.25% due to its hydrophobic character (CA=93.22°±1.95°) (p<0.001). Therefore, the new CF/Flax/Epoxy may be a potential candidate for medical applications as a bone fracture plate, as it showed similar cell viability with no negative effect on gene expression levels responsible for bone formation compared to medical grade stainless steel.

  14. Genetics of the Steller's Sea Cow (Hydrodamalis gigas): A Study of Ancient Bone Material

    Science.gov (United States)

    Crerar, Lorelei D.

    Georg Wilhelm Steller was born 100 years before Darwin in 1709 and he was part of a vast exploration fifty years before Lewis and Clark explored America. Steller was important to the study of marine mammals because he was the only naturalist to see and describe the great northern sea cow ( Hydrodamalis gigas). Knowledge of an extinct population can be used to aid the conservation of a current population. Extraction of DNA from this extinct animal was performed in order to determine the population structure of the Steller's sea cow. A test was also developed that can definitively state whether or not a random bone sample came from H. gigas. This test could be used by the Fish and Wildlife Service (FWS) and the National Oceanic and Atmospheric Administration (NOAA) to examine material distributed in the North Pacific to determine whether samples are legally traded extinct Steller's sea cow or illegally traded extant marine mammal species protected under the Marine Mammal Protection Act (MMPA).

  15. Sealing ability of a new calcium silicate based material as a dentin substitute in class II sandwich restorations: An in vitro study

    Directory of Open Access Journals (Sweden)

    Raji Viola Solomon

    2014-01-01

    Full Text Available Background: Class ll sandwich restorations are routinely performed where conventional Glass ionomer cement (GIC or Resin-modified GIC (RMGIC is used as a base or dentin substitute and a light curing composite resin restorative material is used as an enamel substitute. Various authors have evaluated the microleakage of composite resin restorations where glass ionomer cement has been used as a base in class II sandwich restorations, but a literature survey reveals limited studies on the microleakage analysis of similar restorations with biodentine as a dentin substitute, as an alternative to glass ionomer cement. The aim of this study is: To evaluate the marginal sealing efficacy of a new calcium-silicate-based material (Biodentine as a dentin substitute, at the cervical margins, in posterior class II sandwich restorations.To compare and evaluate the microleakage at the biodentine/composite interface with the microleakage at the resin-modified GIC/composite interface, in posterior class II open sandwich restorations. To compare the efficacy between a water-based etch and rinse adhesive (Scotch bond multipurpose and an acetone-based etch and rinse adhesive (Prime and bond NT, when bonding biodentine to the composite. To evaluate the enamel, dentin, and interfacial microleakage at the composite and biodentine/RMGIC interfaces. Materials and Methods: Fifty class II cavities were prepared on the mesial and distal surfaces of 25 extracted human maxillary third molars, which were randomly divided into five groups of ten cavities each: (G1 Biodentine group, (G2 Fuji II LC GIC group, (G3 Biodentine as a base + prime and bond NT + Tetric N-Ceram composite, (G4 Biodentine + scotchbond multi-purpose + Tetric N-Ceram composite, (G5 Fuji II LC as a base + prime and bond NT+ Tetric-N Ceram composite. The samples were then subjected to thermocycling, 2500× (5°C to 55°C, followed by the dye penetration test. Scores are given from 0 to 3 based on the depth of

  16. Mesenchymal Stem Cells and Platelet Gel Improve Bone Deposition within CAD-CAM Custom-Made Ceramic HA Scaffolds for Condyle Substitution

    Directory of Open Access Journals (Sweden)

    L. Ciocca

    2013-01-01

    Full Text Available Purpose. This study evaluated the efficacy of a regenerative approach using mesenchymal stem cells (MSCs and CAD-CAM customized pure and porous hydroxyapatite (HA scaffolds to replace the temporomandibular joint (TMJ condyle. Methods. Pure HA scaffolds with a 70% total porosity volume were prototyped using CAD-CAM technology to replace the two temporomandibular condyles (left and right of the same animal. MSCs were derived from the aspirated iliac crest bone marrow, and platelets were obtained from the venous blood of the sheep. Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Sheep were sacrificed 4 months postoperatively. The HA scaffolds were explanted, histological specimens were prepared, and histomorphometric analysis was performed. Results. Analysis of the porosity reduction for apposition of newly formed bone showed a statistically significant difference in bone formation between condyles loaded with MSC and condyles without (P<0.05. The bone ingrowth (BI relative values of split-mouth comparison (right versus left side showed a significant difference between condyles with and without MSCs (P<0.05. Analysis of the test and control sides in the same animal using a split-mouth study design was performed; the condyle with MSCs showed greater bone formation. Conclusion. The split-mouth design confirmed an increment of bone regeneration into the HA scaffold of up to 797% upon application of MSCs.

  17. Bio-Oss Bone Substitutes Combined with Bone Rubbish Autotransplantation in Implantation of Maxillary Sinus lift and Simultaneous Dental Implantation%Bio-Oss骨代用品混合自体骨碎屑移植在开窗法上颌窦底提升同期牙种植体植入术中的应用

    Institute of Scientific and Technical Information of China (English)

    韩尚哲; 刘玉柱; 胡青; 谢美艳; 张倩

    2016-01-01

    目的 探讨自体骨碎屑混合Bio-Oss骨代用品用于侧壁开窗上颌窦底提升术同期牙种植体植入的临床效果. 方法 选择2013年1月—2014年6月于解放军62医院口腔科就诊的牙列缺损患者28例,利用种植机于阻生下颌第3磨牙制备合适足量的骨碎屑,与Bio-Oss骨代用品混合植入提升上颌窦底,侧壁开窗区表面覆盖Bio-Gide可吸收胶原膜,种植体同期植入. 观察种植效果. 结果 本组28例共植入32枚种植体,均获得骨结合,种植体无松动脱落. 所有病例完成修复后随访6个月,修复效果满意. 结论 Bio-Oss骨代用品混合自体骨碎屑移植在开窗法上颌窦底提升同期牙种植体植入术中临床效果良好.%Objective To investigate the effect of bone rubbish autotransplantation combined with Bio-Oss bone substitutes in implantation of maxillary sinus lift and simultaneous dental implantation. Methods A total of 28 patients with dentition defect during January 2013 and June 2014 were recruited in this study. The ample numbers of bone rubbish were obtained using bone block of mandibular third molar region, and then were combined with Bio-Oss bone substitutes in implantation of maxillary sinus floor for lifting. Bio-Gide adsorbable collagenous membrane covered the surface of side windowing area with simultaneous implantation. The effect of implantation was observed. Results A total of 32 implants were obtained in the 28 patients, and synostosis was performed for all implants without loosening or shedding. All the pa-tients were followed up for 6 months with satisfactory effect. Conclusion The bio-oss bone substitutes combined with bone rubbish autotransplantation in implantation of maxillary sinus lift and simultaneous dental implantation can achieve good effect.

  18. Evaluation of implant-materials as cell carriers for dental stem cells under in vitro conditions

    OpenAIRE

    Gosau, Martin; Viale-Bouroncle, Sandra; Eickhoff, Hannah; Prateeptongkum, Esthera; Reck, Anja; Götz, W.; Klingelhöffer, Christoph; Müller, Steffen; Morsczeck, Christian

    2015-01-01

    Background Dental stem cells in combination with implant materials may become an alternative to autologous bone transplants. For tissue engineering different types of soft and rigid implant materials are available, but little is known about the viability and the osteogenic differentiation of dental stem cells on these different types of materials. According to previous studies we proposed that rigid bone substitute materials are superior to soft materials for dental tissue engineering. Method...

  19. The impact of bone and suture material properties on mandibular function in Alligator mississippiensis: testing theoretical phenotypes with finite element analysis

    Science.gov (United States)

    Reed, David A; Porro, Laura B; Iriarte-Diaz, Jose; Lemberg, Justin B; Holliday, Casey M; Anapol, Fred; Ross, Callum F

    2011-01-01

    Abstract The functional effects of bone and suture stiffness were considered here using finite element models representing three different theoretical phenotypes of an Alligator mississippiensis mandible. The models were loaded using force estimates derived from muscle architecture in dissected specimens, constrained at the 18th and 19th teeth in the upper jaw and 19th tooth of the lower jaw, as well as at the quadrate-articular joint. Stiffness was varied systematically in each theoretical phenotype. The three theoretical phenotypes included: (i) linear elastic isotropic bone of varying stiffness and no sutures; (ii) linear elastic orthotropic bone of varying stiffness with no sutures; and (iii) linear elastic isotropic bone of a constant stiffness with varying suture stiffness. Variation in the isotropic material properties of bone primarily resulted in changes in the magnitude of principal strain. By comparison, variation in the orthotropic material properties of bone and isotropic material properties of sutures resulted in: a greater number of bricks becoming either more compressive or more tensile, changing between being either dominantly compressive or tensile, and having larger changes in the orientation of maximum principal strain. These data indicate that variation in these model properties resulted in changes to the strain regime of the model, highlighting the importance of using biologically verified material properties when modeling vertebrate bones. When bones were compared within each set, the response of each to changing material properties varied. In two of the 12 bones in the mandible, varied material properties within sutures resulted in a decrease in the magnitude of principal strain in bricks adjacent to the bone/suture interface and decreases in stored elastic energy. The varied response of the mandibular bones to changes in suture stiffness highlights the importance of defining the appropriate functional unit when addressing relationships of

  20. [Combined treatment of long tubular bone fractures and false joints using the bioplastic material collapan (Russia)].

    Science.gov (United States)

    Kesian, G A; Berchenko, G N; Urazgil'deev, R Z; Arsen'ev, I G; Mikelaishvili, D S; Karapetian, G S

    2008-01-01

    This experimental morphological study on 32 dogs was designed to evaluate the efficiency of hydroxyapatite containing preparation collapan used to promote healing of segmented femur defects. Implantation of collapan was shown to greatly contribute to the formation, maturation and remodelling of bone callus. Combined treatment of 165 patients with comminuted fractures and 148 ones with false joints of long tubular bones using collapan implants proved to efficaciously promote bone consolidation in 99.4% of the total 313 subjects. Collapan activated reparative osteogenesis, reduced the duration of hospitalization, the frequency of inflammatory complications, and the requirement of secondary inpatient care.

  1. Microindentation for in vivo measurement of bone tissue material properties in atypical femoral fracture patients and controls.

    Science.gov (United States)

    Güerri-Fernández, Roberto C; Nogués, Xavier; Quesada Gómez, José M; Torres Del Pliego, Elisa; Puig, Lluís; García-Giralt, Natalia; Yoskovitz, Guy; Mellibovsky, Leonardo; Hansma, Paul K; Díez-Pérez, Adolfo

    2013-01-01

    Atypical femoral fractures (AFF) associated with long-term bisphosphonates (LTB) are a growing concern. Their etiology is unknown, but bone material properties might be deteriorated. In an AFF series, we analyzed the bone material properties by microindentation. Four groups of patients were included: 6 AFF, 38 typical osteoporotic fractures, 6 LTB, and 20 controls without fracture. Neither typical osteoporotic fractures nor controls have received any antiosteoporotic medication. A general laboratory workup, bone densitometry by dual-energy X-ray absorptiometry (DXA), and microindentation testing at the tibia were done in all patients. Total indentation distance (Total ID), indentation distance increase (IDI), and creep indentation distance (Creep ID) were measured (microns). Age-adjusted analysis of covariance (ANCOVA) was used for comparisons. Controls were significantly younger than fracture groups. Bisphosphonate exposure was on average 5.5 years (range 5 to 12 years) for the AFF and 5.4 years (range 5 to 8 years) for the LTB groups. Total ID (microns) showed better material properties (lower Total ID) for controls 36 (± 6; mean ± SD) than for AFF 46 (± 4) and for typical femoral fractures 47 (± 13), respectively. Patients on LTB showed values between controls and fractures, 38 (± 4), although not significantly different from any of the other three groups. IDI values showed a similar pattern 13 (± 2), 16 (± 6), 19 (± 3), and 18 (± 5). After adjusting by age, significant differences were seen between controls and typical (p Creep ID between groups. Our data suggest that patients with AFF have a deep deterioration in bone material properties at a tissue level similar to that for the osteoporotic fracture group. The LTB group shows levels that are in between controls and both type of fractures, although not statistically different. These results suggest that bisphosphonate therapy probably does not put the majority of patients at risk

  2. Materials Compatibility and Lubricants Research of CFC-refrigerant substitutes. Quarterly technical progress report, 1 April 1993--30 June 1993

    Energy Technology Data Exchange (ETDEWEB)

    Godwin, D.S.; Hourahan, G.C.; Szymurski, S.R.

    1993-07-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The DCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. The work is guided by an Advisory Committee consisting of technical experts from the refrigeration and air-conditioning industry and government agencies. Under the current MCLR program the Air-Conditioning and Refrigeration Technology Institute, Inc., (ARTI) is contracting and managing multiple research projects and a data collection and dissemination effort. Detailed results from these projects are reported in technical reports prepared by each researcher.

  3. Nature of the Electrochemical Properties of Sulphur Substituted LiMn2O4 Spinel Cathode Material Studied by Electrochemical Impedance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Monika Bakierska

    2016-08-01

    Full Text Available In this work, nanostructured LiMn2O4 (LMO and LiMn2O3.99S0.01 (LMOS1 spinel cathode materials were comprehensively investigated in terms of electrochemical properties. For this purpose, electrochemical impedance spectroscopy (EIS measurements as a function of state of charge (SOC were conducted on a representative charge and discharge cycle. The changes in the electrochemical performance of the stoichiometric and sulphur-substituted lithium manganese oxide spinels were examined, and suggested explanations for the observed dependencies were given. A strong influence of sulphur introduction into the spinel structure on the chemical stability and electrochemical characteristic was observed. It was demonstrated that the significant improvement in coulombic efficiency and capacity retention of lithium cell with LMOS1 active material arises from a more stable solid electrolyte interphase (SEI layer. Based on EIS studies, the Li ion diffusion coefficients in the cathodes were estimated, and the influence of sulphur on Li+ diffusivity in the spinel structure was established. The obtained results support the assumption that sulphur substitution is an effective way to promote chemical stability and the electrochemical performance of LiMn2O4 cathode material.

  4. Cement from magnesium substituted hydroxyapatite.

    Science.gov (United States)

    Lilley, K J; Gbureck, U; Knowles, J C; Farrar, D F; Barralet, J E

    2005-05-01

    Brushite cement may be used as a bone graft material and is more soluble than apatite in physiological conditions. Consequently it is considerably more resorbable in vivo than apatite forming cements. Brushite cement formation has previously been reported by our group following the mixture of nanocrystalline hydroxyapatite and phosphoric acid. In this study, brushite cement was formed from the reaction of nanocrystalline magnesium-substituted hydroxyapatite with phosphoric acid in an attempt to produce a magnesium substituted brushite cement. The presence of magnesium was shown to have a strong effect on cement composition and strength. Additionally the presence of magnesium in brushite cement was found to reduce the extent of brushite hydrolysis resulting in the formation of HA. By incorporating magnesium ions in the apatite reactant structure the concentration of magnesium ions in the liquid phase of the cement was controlled by the dissolution rate of the apatite. This approach may be used to supply other ions to cement systems during setting as a means to manipulate the clinical performance and characteristics of brushite cements.

  5. Quantum mechanical design of efficient second-order nonlinear optical materials based on heteroaromatic imido-substituted hexamolybdates: first theoretical framework of POM-based heterocyclic aromatic rings.

    Science.gov (United States)

    Janjua, Muhammad Ramzan Saeed Ashraf

    2012-11-05

    This work was inspired by a previous report (Janjua et al. J. Phys. Chem. A 2009, 113, 3576-3587) in which the nonlinear-optical (NLO) response strikingly improved with an increase in the conjugation path of the ligand and the nature of hexamolybdates (polyoxometalates, POMs) was changed into a donor by altering the direction of charge transfer with a second aromatic ring. Herein, the first theoretical framework of POM-based heteroaromatic rings is found to be another class of excellent NLO materials having double heteroaromatic rings. First hyperpolarizabilities of a large number of push-pull-substituted conjugated systems with heteroaromatic rings have been calculated. The β components were computed at the density functional theory (DFT) level (BP86 geometry optimizations and LB94 time-dependent DFT). The largest β values are obtained with a donor (hexamolybdates) on the benzene ring and an acceptor (-NO(2)) on pyrrole, thiophene, and furan rings. The pyrrole imido-substituted hexamolybdate (system 1c) has a considerably large first hyperpolarizability, 339.00 × 10(-30) esu, and it is larger than that of (arylimido)hexamolybdate, calculated as 0.302 × 10(-30) esu (reference system 1), because of the double aromatic rings in the heteroaromatic imido-substituted hexamolybdates. The heteroaromatic rings act as a conjugation bridge between the electron acceptor (-NO(2)) and donor (polyanion). The introduction of an electron donor into heteroaromatic rings significantly enhances the first hyperpolarizabilities because the electron-donating ability is substantially enhanced when the electron donor is attached to the heterocyclic aromatic rings. Interposing five-membered auxiliary fragments between strong donor (polyanion) or acceptor (-NO(2)) groups results in a large computed second-order NLO response. The present investigation provides important insight into the NLO properties of (heteroaromatic) imido-substituted hexamolybdate derivatives because these compounds

  6. 3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

    Science.gov (United States)

    Asa'ad, Farah; Giannì, Aldo Bruno; Giannobile, William V.; Rasperini, Giulio

    2016-01-01

    To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration. PMID:27366149

  7. 3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

    Directory of Open Access Journals (Sweden)

    Farah Asa’ad

    2016-01-01

    Full Text Available To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration.

  8. Hydroxyapatite from fish scale for potential use as bone scaffold or regenerative material

    Energy Technology Data Exchange (ETDEWEB)

    Pon-On, Weeraphat, E-mail: fsciwpp@ku.ac.th [Department of Physics, Faculty of Science, Kasetsart University, Bangkok (Thailand); Suntornsaratoon, Panan [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Charoenphandhu, Narattaphol [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand); Thongbunchoo, Jirawan [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Krishnamra, Nateetip [Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok (Thailand); Department of Physiology, Faculty of Science, Mahidol University, Bangkok (Thailand); Tang, I. Ming [Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand)

    2016-05-01

    The present paper studies the physico-chemical, bioactivity and biological properties of hydroxyapatite (HA) which is derived from fish scale (FS) (FSHA) and compares them with those of synthesized HA (sHA) obtained by co-precipitation from chemical solution as a standard. The analysis shows that the FSHA is composed of flat-plate nanocrystal with a narrow width size of about 15–20 nm and having a range of 100 nm in length and that the calcium phosphate ratio (Ca/P) is 2.01 (Ca-rich CaP). Whereas, synthesized HA consists of sub-micron HA particle having a Ca/P ratio of 1.65. Bioactivity test shows that the FSHA forms more new apatite than does the sHA after being incubated in simulated body fluid (SBF) for 7 days. Moreover, the biocompatibility study shows a higher osteoblast like cell adhesion on the FSHA surface than on the sHA substrate after 3 days of culturing. Our results also show the shape of the osteoblast cells on the FSHA changes from being a rounded shape to being a flattened shape reflecting its spreading behavior on this surface. MTT assay and ALP analysis show significant increases in the proliferation and activity of osteoblasts over the FSHA scaffold after 5 days of culturing as compared to those covering the sHA substrates. These results confirm that the bio-materials derived from fish scale (FSHA) are biologically better than the chemically synthesized HA and have the potential for use as a bone scaffold or as regenerative materials. - Highlights: • Preparation of hydroxyapatite (HA) which is derived from fish scale (FS) (FSHA) and their bioactivities • The FSHA is composed of flat-plate nanocrystal with a narrow size of 15–20 nm. • Bioactivity test shows that the FSHA forms more new apatite than does the sHA after being incubated SBF. • In vitro cell availability tests show a higher cell adhesion on the FSHA surface.

  9. Synthesis of substituted pyrazines

    Energy Technology Data Exchange (ETDEWEB)

    Pagoria, Philip F.; Zhang, Mao Xi

    2016-10-04

    A method for synthesizing a pyrazine-containing material according to one embodiment includes contacting an iminodiacetonitrile derivative with a base and a reagent selected from a group consisting of hydroxylamine, a hydroxylamine salt, an aliphatic primary amine, a secondary amine, an aryl-substituted alkylamine a heteroaryl-substituted alkyl amine, an alcohol, an alkanolamine and an aryl alcoholamine. Additional methods and several reaction products are presented. ##STR00001##

  10. Nuevos enfoques para mejorar las propiedades mecánicas y biológicas de substitutos óseos basados en calcio (New Approaches for Improving Mechanical and Biological Properties of Calcium-Based Bone Substitutes

    Directory of Open Access Journals (Sweden)

    Arias Fernández, José Ignacio.

    2007-12-01

    Full Text Available ResumenEl proceso biológico por el cual los seres vivos logran una mineralización inorgánica se conoce como biomineralización. Las investigaciones en implantes óseos han intentado aprovechar el proceso natural de regeneración del hueso, utilizando sustitutos óseos que posean características de osteo-inducción, integración y conducción similares al hueso propio. Entre los sustitutos óseos podemos mencionar el uso de estructuras calcáreas naturales como la de los corales (compuestos de carbonato de calcio que en algunos casos son fosfatados superficialmente, la generación de diversos cementos y cerámicas porosas en base a fosfato tricálcico a y b solos o mezclados con compuestos orgánicos naturales o sintéticos; como pueden ser entre otros colágeno, quitosano, hidrogeles, derivados del ácido poliglicólico o compuestos acrílicos para mejorar sus deficiencias de rapidez de disolución y mejorar las propiedades mecánicas. Una de las formas más ocupadas del fosfato de calcio es la hidroxiapatita (HA que también ha sido mezclada con diversos compuestos orgánicos e inorgánicos con el fin de mejorar su resistencia a fuerzas de tensión, compresión y flexión. Los desafíos futuros son por lo tanto lograr compuestos que no sólo permitan la regeneración ósea sino que además den soporte mecánico mientras este proceso ocurre. En la presente monografía se revisan las principales características químicas, físicas y biológicas de los compuestos cálcicos utilizados como sustitutos óseos, y se proponen nuevos enfoques que deberían considerarse para mejorar su eficiencia. SummaryThe biological process for which living organisms achieve an inorganic mineralization is known as biomineralization. Research in bone implants has tried to mimick the natural process of regeneration of bone by using bone substitutes possessing characteristics of osteo-induction, integration and conduction similar to that of natural bone. Among other

  11. Osteoclast-like cells on deproteinized bovine bone mineral and biphasic calcium phosphate

    DEFF Research Database (Denmark)

    Jensen, Simon S; Gruber, Reinhard; Buser, Daniel;

    2015-01-01

    OBJECTIVES: The occurrence of multinucleated giant cells (MNGCs) on bone substitute materials has been recognized for a long time. However, there have been no studies linking material characteristics with morphology of the MNGCs. The aim was to analyze the qualitative differences of MNGCs on two ...

  12. Polymeric scaffolds as stem cell carriers in bone repair.

    Science.gov (United States)

    Rossi, Filippo; Santoro, Marco; Perale, Giuseppe

    2015-10-01

    Although bone has a high potential to regenerate itself after damage and injury, the efficacious repair of large bone defects resulting from resection, trauma or non-union fractures still requires the implantation of bone grafts. Materials science, in conjunction with biotechnology, can satisfy these needs by developing artificial bones, synthetic substitutes and organ implants. In particular, recent advances in polymer science have provided several innovations, underlying the increasing importance of macromolecules in this field. To address the increasing need for improved bone substitutes, tissue engineering seeks to create synthetic, three-dimensional scaffolds made from polymeric materials, incorporating stem cells and growth factors, to induce new bone tissue formation. Polymeric materials have shown a great affinity for cell transplantation and differentiation and, moreover, their structure can be tuned in order to maintain an adequate mechanical resistance and contemporarily be fully bioresorbable. This review emphasizes recent progress in polymer science that allows relaible polymeric scaffolds to be synthesized for stem cell growth in bone regeneration.

  13. Development of anode material based on La-substituted SrTiO{sub 3} perovskites doped with manganese and/or gallium for SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Escudero, M.J. [Dpto Energia, CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); School of Chemistry, Purdie Building, University of St Andrews, St Andres, Fife KY16 9ST (United Kingdom); Irvine, J.T.S. [School of Chemistry, Purdie Building, University of St Andrews, St Andres, Fife KY16 9ST (United Kingdom); Daza, L. [Dpto Energia, CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), Campus Cantoblanco, C/Marie Curie 2, 28049 Madrid (Spain)

    2009-07-01

    Materials based on La-substituted SrTiO{sub 3} perovskites doped with manganese and/or gallium for SOFC have been studied as novel anodes for solid oxide fuel cell. La{sub 4}Sr{sub 8}Ti{sub 11}Mn{sub 1-x}Ga{sub x}O{sub 38-{delta}} (0 {<=} x {<=} 1) oxides were synthesized by solid state reaction and the influences of the manganese and/or gallium content on the structure, morphology, thermal properties and electrical conductivity of these materials has been investigated. All compounds show cubic structure with a space group Pm-3m. These compounds presented high electrical conductivity values under reducing atmosphere between 7.9 and 6.8 S cm{sup -1} at 900 C. For the composition x {>=} 0.5, the thermal expansion coefficient in both reducing and oxidizing atmosphere are close to that of SOFC electrolytes (8YSZ, CGD). In general, the substitution of Ga by Mn causes a slight reduction in each of the following, lattice parameter, degree of oxygen loss on reduction, thermal expansion coefficient, and electrical conductivity. (author)

  14. Development of primers for detection of heat-treated cetacean materials in porcine meat and bone meal.

    Science.gov (United States)

    Shinoda, Naoki; Yoshida, Tomotaro; Kusama, Toyoko; Takagi, Masami; Onodera, Takashi; Sugiura, Katsuaki

    2009-07-01

    The feed ban introduced after the detection of the first case of bovine spongiform encephalopathy in 2001 in Japan has been modified to allow some of the previously prohibited animal materials to be used in animal feed. Recently, porcine materials were allowed to be used in feed for pigs, poultry, and fish. Materials from other mammals, including whales, remain prohibited. In the absence of a method to detect the prohibited whale materials in porcine materials, there is a possibility that the whale materials are being used for feed for pigs, poultry, and fish. To detect illegal use of whale materials mixed with porcine materials, we have developed PCR primers specific to a group of most cetacean species, using a computer-based method we developed previously. The primer sets were capable of detecting whale meat meal that had been autoclaved at 133 degrees C for up to 20 min. The detection limit of whale material in porcine meat and bone meal was 0.1%.

  15. Geometrical and material parameters to assess the macroscopic mechanical behaviour of fresh cranial bone samples.

    Science.gov (United States)

    Auperrin, Audrey; Delille, Rémi; Lesueur, Denis; Bruyère, Karine; Masson, Catherine; Drazétic, Pascal

    2014-03-21

    The present study aims at providing quantitative data for the personalisation of geometrical and mechanical characteristics of the adult cranial bone to be applied to head FE models. A set of 351 cranial bone samples, harvested from 21 human skulls, were submitted to three-point bending tests at 10 mm/min. For each of them, an apparent elastic modulus was calculated using the beam's theory and a density-dependant beam inertia. Thicknesses, apparent densities and percentage of ash weight were also measured. Distributions of characteristics among the different skull bones show their symmetry and their significant differences between skull areas. A data analysis was performed to analyse potential relationship between thicknesses, densities and the apparent elastic modulus. A specific regression was pointed out to estimate apparent elastic modulus from the product of thickness by apparent density. These results offer quantitative tools in view of personalising head FE models and thus improve definition of local injury criteria for this body part.

  16. Enhanced osteoconductivity of sodium-substituted hydroxyapatite by system instability.

    Science.gov (United States)

    Sang Cho, Jung; Um, Seung-Hoon; Su Yoo, Dong; Chung, Yong-Chae; Hye Chung, Shin; Lee, Jeong-Cheol; Rhee, Sang-Hoon

    2014-07-01

    The effect of substituting sodium for calcium on enhanced osteoconductivity of hydroxyapatite was newly investigated. Sodium-substituted hydroxyapatite was synthesized by reacting calcium hydroxide and phosphoric acid with sodium nitrate followed by sintering. As a control, pure hydroxyapatite was prepared under identical conditions, but without the addition of sodium nitrate. Substitution of calcium with sodium in hydroxyapatite produced the structural vacancies for carbonate ion from phosphate site and hydrogen ion from hydroxide site of hydroxyapatite after sintering. The total system energy of sodium-substituted hydroxyapatite with structural defects calculated by ab initio methods based on quantum mechanics was much higher than that of hydroxyapatite, suggesting that the sodium-substituted hydroxyapatite was energetically less stable compared with hydroxyapatite. Indeed, sodium-substituted hydroxyapatite exhibited higher dissolution behavior of constituent elements of hydroxyapatite in simulated body fluid (SBF) and Tris-buffered deionized water compared with hydroxyapatite, which directly affected low-crystalline hydroxyl-carbonate apatite forming capacity by increasing the degree of apatite supersaturation in SBF. Actually, sodium-substituted hydroxyapatite exhibited markedly improved low-crystalline hydroxyl-carbonate apatite forming capacity in SBF and noticeably higher osteoconductivity 4 weeks after implantation in calvarial defects of New Zealand white rabbits compared with hydroxyapatite. In addition, there were no statistically significant differences between hydroxyapatite and sodium-substituted hydroxyapatite on cytotoxicity as determined by BCA assay. Taken together, these results indicate that sodium-substituted hydroxyapatite with structural defects has promising potential for use as a bone grafting material due to its enhanced osteoconductivity compared with hydroxyapatite.

  17. Comparación entre distintos sustitutos óseos utilizados para procedimientos de elevación de seno maxilar previo a la colocación de implantes dentales Comparison between different bone substitutes for maxillary sinus floor augmentation prior to placement of dental implants

    Directory of Open Access Journals (Sweden)

    M. Muñoz Corcuera

    2008-12-01

    standard of bone grafting materials, it is associated with morbidity and limited availability. The aim of this revision was to evaluate the bone substitutes for sinus floor augmentation prior to the placement of dental implants. Materials and Methods: An electronic literature search was conducted in the Cochrane database and Pubmed. Studies analysing graft materials for sinus floor augmentation were chosen. Results: 13 articles were selected for the revision, from which 2 groups were established for comparison; those studies based in histological and mineralisation analyses and those evaluating clinical parameters and the survival rate of the implants. Discussion: Due to the different findings of the studies, there is no material that can be considered preferable over any other. It would be desirable that future studies had longer follow-ups, larger samples, compared different graft materials and evaluated histological and clinical results simultaneously. Conclusions: Autogenous bone is still considered the gold standard of graft materials; however, it is associated with a high complication rate. Although more studies are needed, bovine hydroxiapatite and ß-tricalcium phosphate have achieved promising results.

  18. Smooth surface micro finite element modelling of a cancellous bone analogue material.

    Science.gov (United States)

    Leung, S Y; Browne, M; New, A M

    2008-01-01

    Tetrahedral finite element meshes with smooth surfaces can be created from computed tomography scans of cancellous bone in order to evaluate its mechanical properties. Image processing before creation of the mesh can affect the accuracy of determined mechanical properties. For a cancellous bone analogue, threshold, mesh density and surface smoothing parameters used in mesh generation were varied and the mechanical properties predicted by the resulting meshes were compared to experimental results. This study has shown that threshold selection is vital for accurate determination of volume fraction and resulting mechanical properties.

  19. Geometrical and material parameters to assess the macroscopic mechanical behaviour of fresh cranial bone samples

    OpenAIRE

    AUPERRIN, Audrey; Delille, Rémi; LESUEUR, Denis; BRUYERE, Karine; Masson, Catherine; Drazetic, Pascal

    2014-01-01

    The present study aims at providing quantitative data for the personalisation of geometrical and 21 mechanical characteristics of the adult cranial bone to be applied to head FE models. A set of 351 22 cranial bone samples, harvested from 21 human skulls, were submitted to three-point bending tests 23 at 10 mm/min. For each of them, an apparent elastic modulus was calculated using the beam's 24 theory and a density-dependant beam inertia. Thicknesses, apparent densities and percentage of ash ...

  20. Fabrication and materials properties of high-density polyethylene (HDPE)/biphasic calcium phosphate (BCP) hybrid bone plates

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Sun Young; Youn, Min Ho; Lim, Youn Mook; Gwon, Hui Jeong; Park, Jong Seok; Nho, Young Chang [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-06-15

    Biphasic calcium phosphate-reinforced high-density polyethylene (BCP/HDPE) hybrid composite is a new orthopedic biomaterial, which was made to simulate a natural bone composition. Calcium phosphate systems and HDPE hybrid composites have been used in biomedical applications without any inflammatory response. Differences in natural bone of both materials have motivated the use of coupling agents to improve their interfacial interfacial interactions. The composites were prepared using medical grade BCP powder and granular polyethylene. This material was produced by replacing the mineral component and collagen soft tissue of the bone with BCP and HDPE, respectively. As expected, increased volume fraction of either reinforcement type over 0 {approx} 50 vol.% resulted in a increased Vickers hardness and Young's modulus. Thus, BCP particle-reinforced HDPE composites possessed improved material and mechanical properties. BCP particles-reinforced composites were anisotropic due to an alignment of the particles in the matrix during a processing. On the other hand, bending and tensile strength was dramatically changed in the matrix. To change the material and mechanical properties of HDPE/BCP composites, the process of a blending was used, and its effect on the microstructure and mechanical proprieties of HDPE/BCP composites were investigated by means of FT-IR/ATR spectroscopy, XRD, FE-SEM, Vickers Hardness Testing Machine, Universal Testing Machine, Mercury Porosimeter and Ultrasonic Flaw Detector at room temperature. For the evaluation of the cell viability and proliferation onto the external surface of HDPE/BCP hybrid plates with a HaCaT cell line, which is a multipotent cell line able to differentiate towards different phenotypes under the action of biological factors, has been evaluated with in vitro studies and quantified by colormetric assays. These findings indicate that the HDPE/BCP hybrid plates are biocompatible and non-toxic.

  1. Orthopaedic tissue engineering and bone regeneration.

    Science.gov (United States)

    Dickson, Glenn; Buchanan, Fraser; Marsh, David; Harkin-Jones, Eileen; Little, Uel; McCaigue, Mervyn

    2007-01-01

    Orthopaedic tissue engineering combines the application of scaffold materials, cells and the release of growth factors. It has been described as the science of persuading the body to reconstitute or repair tissues that have failed to regenerate or heal spontaneously. In the case of bone regeneration 3-D scaffolds are used as a framework to guide tissue regeneration. Mesenchymal cells obtained from the patient via biopsy are grown on biomaterials in vitro and then implanted at a desired site in the patient's body. Medical implants that encourage natural tissue regeneration are generally considered more desirable than metallic implants that may need to be removed by subsequent intervention. Numerous polymeric materials, from natural and artificial sources, are under investigation as substitutes for skeletal elements such as cartilage and bone. For bone regeneration, cells (obtained mainly from bone marrow aspirate or as primary cell outgrowths from bone biopsies) can be combined with biodegradable polymeric materials and/or ceramics and absorbed growth factors so that osteoinduction is facilitated together with osteoconduction; through the creation of bioactive rather than bioinert scaffold constructs. Relatively rapid biodegradation enables advantageous filling with natural tissue while loss of polymer strength before mass is disadvantageous. Innovative solutions are required to address this and other issues such as the biocompatibility of material surfaces and the use of appropriate scaffold topography and porosity to influence bone cell gene expression.

  2. Bone Formation with Deproteinized Bovine Bone Mineral or Biphasic Calcium Phosphate in the Presence of Autologous Platelet Lysate: Comparative Investigation in Rabbit

    Directory of Open Access Journals (Sweden)

    Carole Chakar

    2014-01-01

    Full Text Available Bone substitutes alone or supplemented with platelet-derived concentrates are widely used to promote bone regeneration but their potency remains controversial. The aim of this study was, therefore, to compare the regenerative potential of preparations containing autologous platelet lysate (APL and particles of either deproteinized bovine bone mineral (DBBM or biphasic calcium phosphate (BCP, two bone substitutes with different resorption patterns. Rabbit APL was prepared by freeze-thawing a platelet suspension. Critical-size defects in rabbit femoral condyle were filled with DBBM or DBBM+APL and BCP or BCP+APL. Rabbits were sacrificed after six weeks and newly formed bone and residual implanted material were evaluated using nondemineralized histology and histomorphometry. New bone was observed around particles of all fillers tested. In the defects filled with BCP, the newly formed bone area was greater (70%; P<0.001 while the residual material area was lower (60%; P<0.001 than that observed in those filled with DBBM. New bone and residual material area of defects filled with either APL+DBBM or APL+BCP were similar to those observed in those filled with the material alone. In summary, osteoconductivity and resorption of BCP were greater than those of DBBM, while APL associated with either DBBM or BCP did not have an additional benefit.

  3. Culture of osteoblasts on bio-derived bones

    Institute of Scientific and Technical Information of China (English)

    LAN Xu; YANG Zhi-ming; GE Bao-feng; LIU Xue-mei

    2005-01-01

    Objective: To study the effect of bio-derived bones, as substitutes of autogenous bone grafts and demineralized cadaver bones, on the attachment, spreading and proliferation of isolated osteoblasts. Methods: Osteoblasts were isolated from the calvaria of a fetal rabbit through sequential collagenase digestion. In the attachment study, the osteoblasts labeled with 3H-leucine were incubated with the bio-derived bone materials in sterile microcentrifugale tubes for 15, 90 and 180 minutes, and 24 hours, respectively. The attached cells were collected and the radioactivity was measured with liquid scintillation spectrometry. In the proliferation study, the osteoblasts were cultured with the bio-derived bone materials for 24 hours and 3H-thymidine was added during the last 2 hours of the incubation. The attached cells were collected and the radioactivity was measured with liquid scintillation spectrometry. Osteoblasts were seeded on the bone graft materials for 60 or 120 minutes, 24 or 48 hours, and 3 or 7 days, then the co-culture was processed for scanning electron microscopy to observe the interaction of osteoblasts and the bio-derived bone materials. Results: Osteoblasts attached to the bio-derived bone materials in a time-dependent manner. There were significantly (P<0.05) more attached cells after 180 minutes than after 15 and 90 minutes of incubations (P<0.05). Osteoblasts were proliferated in a large amount on the surface and in the materials. Osteoblasts seeded onto 100 mg bio-derived bones resulted in significantly (P<0.05) more measurable proliferation than those seeded onto 10 mg bones. Osteoblasts appeared round as they attached to the materials, then flattened and spread over with time passing. Conclusions: Bio-derived bones can provide a good environment for the attachment and proliferation of osteoblasts.

  4. Substitutional analysis

    CERN Document Server

    Rutherford, Daniel Edwin

    2013-01-01

    Classic monograph, suitable for advanced undergraduates and graduate students. Topics include calculus of permutations and tableaux, semi-normal representation, orthogonal and natural representations, group characters, and substitutional equations. 1968 edition.

  5. Regulation of Bone Metabolism.

    Science.gov (United States)

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-04-01

    Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs) differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation, and bone homeostasis are controlled by various markers and signaling pathways. Bone needs to be remodeled to maintain integrity with osteoblasts, which are bone-forming cells, and osteoclasts, which are bone-degrading cells.In this review we considered the major factors and signaling pathways in bone formation; these include fibroblast growth factors (FGFs), bone morphogenetic proteins (BMPs), wingless-type (Wnt) genes, runt-related transcription factor 2 (RUNX2) and osteoblast-specific transcription factor (osterix or OSX).

  6. Regulation of Bone Metabolism

    Science.gov (United States)

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-01-01

    Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs) differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation, and bone homeostasis are controlled by various markers and signaling pathways. Bone needs to be remodeled to maintain integrity with osteoblasts, which are bone-forming cells, and osteoclasts, which are bone-degrading cells.In this review we considered the major factors and signaling pathways in bone formation; these include fibroblast growth factors (FGFs), bone morphogenetic proteins (BMPs), wingless-type (Wnt) genes, runt-related transcription factor 2 (RUNX2) and osteoblast-specific transcription factor (osterix or OSX). PMID:28367467

  7. Fabrication of highly porous scaffold materials based on functionalized oligolactides and preliminary results on their use in bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Vogt S.

    2002-12-01

    Full Text Available Tissue engineering offers a promising new approach to repair bone defects. Its practical realisation is connected with the development of suitable scaffold materials. In the present work, functionalized oligolactides have been prepared and used as macromers for the scaffold fabrication The developed fabrication process leads to highly porous scaffolds, available in various shapes and sizes, with an open inter-connective pore structure and porosities up to 90 %. Degradable or even osteoconductive components as well as biocompatible co-monomers can be used as additives to modulate the scaffold properties. Under in vitro conditions, the scaffolds exhibit a continuous degradation with varying degradation rates depending on their material composition. In vitro studies on the cultivation of osteoblasts on the scaffolds were performed and revealed their excellent biocompatibility. Cell growth on the scaffold surfaces and inside the scaffolds, formation of extracellular matrix and starting mineralization were detected by microscopical and histological analyses. Based on these results the developed materials are well-suited candidates for the design of tailor-made matrices in bone tissue engineering

  8. Bone cutting.

    Science.gov (United States)

    Giraud, J Y; Villemin, S; Darmana, R; Cahuzac, J P; Autefage, A; Morucci, J P

    1991-02-01

    Bone cutting has always been a problem for surgeons because bone is a hard living material, and many osteotomes are still very crude tools. Technical improvement of these surgical tools has first been their motorization. Studies of the bone cutting process have indicated better features for conventional tools. Several non-conventional osteotomes, particularly ultrasonic osteotomes are described. Some studies on the possible use of lasers for bone cutting are also reported. Use of a pressurised water jet is also briefly examined. Despite their advantages, non-conventional tools still require improvement if they are to be used by surgeons.

  9. Biologically Inspired Self-assembling Synthesis of Bone-like Nano-hydroxyapatite/PLGA- (PEG-ASP)n Composite: A New Biomimetic Bone Tissue Engineering Scaffold Material

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new biomimetic bone tissue engineering scaffold material, nano-HA/ PLGA-( PEG- ASP )n composite, was synthesized by a biologically inspired self assembling approach. A novel biodegradable PLGA( PEG-ASP ) n copolymer with pendant amine functional groups and enhanced hydrophilicity was synthesized by bulk ring-opening copolymerization by DL-lactide( DLLA ) and glycolide( GA ) with Aspartic acid ( ASP )-Polyethylene glycol( PEG ) alt-prepolymer. A Three-dimensional, porous scaffold of the PLGA-( PEG-ASP )n copolymer was fabricated by a solvent casting, particulate leaching process. The scaffold was then incubated in modified simulated body fluid ( mSBF ) . Growth of HA nanocrystals on the inner pore surfaces of the porous scaffold is confirmed by calcium ion binding analyses, SEM, mass increase measurements and quantification of phosphate content within scaffolds . SEM analysis demonstrated the nucleation and growth of a continuous bonelike, low crystalline carbonated HA nanocrystals on the inner pore surfawes of the PLGA-( PEG-ASP)n scaffolds. The amount of calcium binding, total mass and the mass of pbosphate on experimental PLGA-( PEG- ASP )n scaffolds at different incubation times in mSBF was significantly greater than that of control PLGA scaffolds . This nano-HA/ PLGA- ( PEG-ASP )n composite shows some features of natural bone both in main composition and hierarchical microstructure. The ASPPEG alt-prepolymer modified PLGA copolymer provide a controllable high surface density and distribution of anionic functional groups which would enhauce nucleation and growth of bonelike mineral following exposure to mSBF. This biomimetic treatment provides a simple method for surface funetionalization and subsequent mineral nucleation and self-assembling on biodegradable polymer scaffolds for tissue engineering.

  10. Microscopy and image analysis based approaches for the species-specific identification of bovine and swine bone containing material

    Directory of Open Access Journals (Sweden)

    Matteo Ottoboni

    2014-05-01

    Full Text Available The aim of this study was to evaluate the potential of image analysis measurements in combination with the official analytical method for the detection of constituents of animal origin in feedstuffs, in distinguishing between bovine and swine (bone containing material. Authentic samples of controlled origin containing bovine or swine meat and bone meals were analysed by the microscopic method, in accordance with the official analytical method. Sediment fractions of each sample were observed with a compound microscope at X40. A total of 362 bone fragment lacunae images were recorded and processed through image analysis software, deriving 30 geometric variables for each lacuna. Results indicated that not only were most variables significantly (P<0.001 different between bovine and swine samples, but also that two thirds of the same variables were bigger in bovine than in swine. This information, however, does not seem to be so effective in practice since bovine and swine features and measurements overlapped. It can be concluded that the microscopic method even when combined with image analysis does not fit all the requirements for accurately identifying prohibited ingredients of animal origin. A combined approach with other methods is therefore recommended.

  11. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals: Significantly Reduced Bone Stock in the Metaphyseal and Subcapital Regions of Osteoporotic Individuals.

    Science.gov (United States)

    Sprecher, Christoph M; Schmidutz, Florian; Helfen, Tobias; Richards, R Geoff; Blauth, Michael; Milz, Stefan

    2015-12-01

    Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred.The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals.The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis.At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side.This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus.

  12. Reduction in fluoride-induced genotoxicity in mouse bone marrow cells after substituting high fluoride-containing water with safe drinking water.

    Science.gov (United States)

    Podder, Santosh; Chattopadhyay, Ansuman; Bhattacharya, Shelley

    2011-10-01

    Treatment of mice with 15 mg l(-1) sodium fluoride (NaF) for 30 days increased the number of cell death, chromosomal aberrations (CAs) and 'cells with chromatid breaks' (aberrant cells) compared with control. The present study was intended to determine whether the fluoride (F)-induced genotoxicity could be reduced by substituting high F-containing water after 30 days with safe drinking water, containing 0.1 mg F ions l(-1). A significant fall in percentage of CAs and aberrant cells after withdrawal of F-treatment following 30 days of safe water treatment in mice was observed which was highest after 90 days, although their levels still remained significantly high compared with the control group. This observation suggests that F-induced genotoxicity could be reduced by substituting high F-containing water with safe drinking water. Further study is warranted with different doses and extended treatment of safe water to determine whether the induced damages could be completely reduced or not.

  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. New design strategy for the two-photon active material based on push-pull substituted bisanthene molecule.

    Science.gov (United States)

    Chattopadhyaya, Mausumi; Alam, Md Mehboob; Chakrabarti, Swapan

    2011-03-31

    In the present work, we have critically examined the origin of strong two-photon transition probability of a donor-acceptor substituted bisanthene molecule that imitates a small piece of edge passivated (4, 4) graphene nanoribbon. In our calculations, we have considered -OMe, and -NH(2) as donors and -NO(2) as an acceptor. The one- and two-photon absorption parameters are evaluated using state-of-the-art linear and quadratic response theory, respectively, and all these calculations are carried out within the framework of time dependent density functional theory. To give a proper judgment on our findings, we have used the long-range corrected CAMB3LYP functional for all of the time dependent calculations. The present investigation reveals that the bisanthene molecule with three pairs of donor/acceptor moiety has a lower two-photon transition probability than that of a suitably designed bisanthene with only a single pair of donor/acceptor moiety. This in silico observation is consistent for all of the donor/acceptor moieties chosen in the present work. A comprehensive analysis at the two state model level of theory clearly offers us a verdict that by placing the donor/acceptor moiety in a suitable position of bisanthene, we can create a significant asymmetry in the electron density in the first excited state, which eventually leads to a significant difference in the ground and excited state dipole moment and is attributed to the higher two-photon transition probability of a particular bisanthene with a single pair of donor/acceptor moiety than bisanthene with three pairs of donor/acceptor.

  15. Impact of the chemical composition of poly-substituted hydroxyapatite particles on the in vitro pro-inflammatory response of macrophages.

    Science.gov (United States)

    Douard, Nathalie; Leclerc, Lara; Sarry, Gwendoline; Bin, Valérie; Marchat, David; Forest, Valérie; Pourchez, Jérémie

    2016-04-01

    To improve the biological properties of calcium phosphate (CaP) bone substitute, new chemical compositions are under development. In vivo such materials are subject to degradation that could lead to particles release and inflammatory reactions detrimental to the bone healing process. This study aimed at investigating the interactions between a murine macrophage cell line (RAW 264.7) and substituted hydroxyapatite particles presenting promising biological properties. Micron size particles of stoichiometric and substituted hydroxyapatites (CO3 substitution for PO4 and OH; SiO4 substitution for PO4; CO3 and SiO4 co-substitution) were obtained by aqueous precipitation followed by spray drying. Cells, incubated with four doses of particles ranging from 15 to 120 μg/mL, revealed no significant LDH release or ROS production, indicating no apparent cytotoxicity and no oxidative stress. TNF-α production was independent of the chemistry of the particles; however the particles elicited a significant dose-dependent pro-inflammatory response. As micron size particles of these hydroxyapatites could be at the origin of inflammation, attention must be paid to the degradation behavior of substituted hydroxyapatite bone substitute in order to limit, in vivo, the generation of particulate debris.

  16. Physical and chemical characterisation of crude meat and bone meal combustion residue: "waste or raw material?".

    Science.gov (United States)

    Deydier, Eric; Guilet, Richard; Sarda, Stéphanie; Sharrock, Patrick

    2005-05-20

    As a result of the recent bovine spongiform encephalopathy (BSE) crisis in the European beef industry, the use of animal by-product is now severely controlled. Meat and bone meal (MBM) production can no longer be used to feed cattle and must be safely disposed of or transformed. Main disposal option is incineration, producing huge amounts of ashes the valorisation of which becomes a major concern. The aim of this work is to characterise MBM combustion residue in order to evaluate their physical and chemical properties to propose new valorisation avenues. The thermal behaviour of crude meat and bone meal was followed by thermogravimetric analysis (TGA) and (24 wt.%) inorganic residue was collected. The resulting ashes were characterised by powder X-ray diffraction (XRD), particle size distribution, specific surface area (BET), scanning electron microscopy (SEM) couple with energy disperse X-ray analysis (EDX). Elemental analysis revealed the presence of chloride, sodium, potassium, magnesium with high level of phosphate (56 wt.%) and calcium (31 wt.%), two major constituents of bone, mainly as a mixture of Ca10(PO4)6(OH)2 and Ca3(PO4)2 phases. The impact of combustion temperature (from 550 to 1000 degrees C) on the constitution of ashes was followed by TGA, XRD and specific surface measurements. We observed a strong decrease of surface area for the ashes with crystallisation of calcium phosphates phases without major changes of chemical composition.

  17. Micro-finite element simulation of trabecular-bone post-yield behaviour--effects of material model, element size and type.

    Science.gov (United States)

    Verhulp, E; Van Rietbergen, B; Muller, R; Huiskes, R

    2008-08-01

    Micro-finite element (micro-FE) analysis became a standard tool for the evaluation of trabecular bone mechanical properties. The accuracy of micro-FE models for linear analyses is well established. However, the accuracy of recently developed nonlinear micro-FE models for simulations of trabecular bone failure is not known. In this study, a trabecular bone specimen was compressed beyond the apparent yield point. The experiment was simulated using different micro-FE meshes with different element sizes and types, and material models based on cortical bone. The results from the simulations were compared with experimental results to study the effects of the different element and material models. It was found that a decrease in element size from 80 to 40 mum had little effect on predicted post-yield behaviour. Element type and material model had significant effects. Nevertheless, none of the established material models for cortical bone were able to predict the typical descent in the load-displacement curve seen during compression of trabecular bone.

  18. Acridizinium-Substituted Dendrimers As a New Potential Rewritable Optical Data Storage Material for Blu-ray

    DEFF Research Database (Denmark)

    Lohse, Brian; Vestberg, Robert; Ivanov, Mario T.

    2008-01-01

    . This provides an alternative chromophore for rewritable optical data storage media to the existing dye materials such as azo, cyanine, and phthalocyanine dyes for Blu-ray recording. The compound was initially tested in ethanol, showing good reversible properties and photoinduced degree of dimerization...

  19. Different bone graft fusion materials applied in lumbar interbody fusion%不同植骨融合材料在腰椎椎体间脊柱融合中的应用

    Institute of Scientific and Technical Information of China (English)

    覃建朴; 王翀; 张朋云; 曹广如; 蔡玉强; 廖文波

    2016-01-01

    背景:脊柱融合治疗时选择合适的替代移植骨具有重要的意义,能够解决自体骨移植及其他移植材料带来的弊端。目的:观察不同植骨融合材料性能,探讨不同植骨融合材料在犬腰椎椎体间脊柱融合中的应用效果。方法:选取45只中华田园犬建立腰椎椎体间脊柱融合模型,建模后随机分3组,分别植入自体髂骨、重组人骨形态发生蛋白2复合材料和同种异体髂骨,分析不同植骨融合材料在犬腰椎椎体间脊柱融合中的效果。结果与结论:①融合率:重组人骨形态发生蛋白2复合材料组犬融合率显著高于其他组(P <0.05);②Oswestry 功能障碍指数:重组人骨形态发生蛋白2复合材料组术后 Oswestry 功能障碍指数显著低于其他2组(P <0.05);②组织学形态:苏木精-伊红染色显示,术后12周,与其他2组相比,重组人骨形态发生蛋白2犬完全骨性融合,且形成了连续骨小梁,植入骨与犬上下椎体完全粘连;④结果提示:重组人骨形态发生蛋白2复合材料更能够促更好地促进脊柱愈合,效果优于自体和同种异体骨移植。%BACKGROUND: The choice of suitable bone graft substitute is vital for spinal fusion treatment, which can solve some limitations caused by autogenous bone graft and other materials. OBJECTIVE: To investigate properties of different bone graft fusion materials, and to explore their application in dog spinal fusion of lumbar vertebral body. METHODS: Forty-five Chinese rural dogs were enrol ed to prepare lumbar interbody fusion models, and then were randomized into three groups transplanted with autogenous ilium, recombinant human bone morphogenetic protein-2 composite or al ograft ilium, respectively. Afterwards, effects of different materials in the lumbar interbody fusion were analyzed. RESULTS AND CONCLUSION: The fusion rate of the composite group was significantly higher than those of the other

  20. Characterization of PCBs from computers and mobile phones, and the proposal of newly developed materials for substitution of gold, lead and arsenic.

    Science.gov (United States)

    Dervišević, Irma; Minić, Duško; Kamberović, Željko; Ćosović, Vladan; Ristić, Mirjana

    2013-06-01

    In this paper, we have analyzed parts of printed circuit board (PCB) and liquid crystal display (LCD) screens of mobile phones and computers, quantitative and qualitative chemical compositions of individual components, and complete PCBs were determined. Differential thermal analysis (DTA) and differential scanning calorimetry (DSC) methods were used to determine the temperatures of phase transformations, whereas qualitative and quantitative compositions of the samples were determined by X-ray fluorescence spectrometry (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES), and scanning electron microscopy (SEM)-energy dispersive X-ray spectrometry (EDS) analyses. The microstructure of samples was studied by optical microscopy. Based on results of the analysis, a procedure for recycling PCBs is proposed. The emphasis was on the effects that can be achieved in the recycling process by extraction of some parts before the melting process. In addition, newly developed materials can be an adequate substitute for some of the dangerous and harmful materials, such as lead and arsenic are proposed, which is in accordance with the European Union (EU) Restriction of the use of certain hazardous substances (RoHS) directive as well as some alternative materials for use in the electronics industry instead of gold and gold alloys.

  1. Synthesis and characterization of pure STW-zeotype germanosilicate, Cu- and Co-substituted STW-zeotype materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Na [Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Shi, Lei, E-mail: qg_shilei@163.com [Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Yu, Tingting [Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Li, Tianduo, E-mail: ylpt6296@vip.163.com [Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353 (China); Hua, Wei; Lin, Cong [College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2015-05-15

    Pure STW-type germanosilicate (denoted as GeSi-STW), Cu- and Co-containing STW-zeotype (denoted as Cu-STW and Co-STW) materials were synthesized by the hydrothermal method in the presence of an organic structure-directing agent (OSDA), N,N-diethylethylenediamine (DEEDA). The effects of the reaction mixture ratio and the incorporation of transition metals M (M=Cu and Co) on the synthesis of the pure product was investigated. The synthesized samples were characterized by powder and single-crystal X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma analysis (ICP), thermogravimetric and differential scanning calorimetry (TG–DSC) analysis and UV–vis diffuse reflectance spectra (DRS). The results reveal that the crystallization time, the concentration of H{sub 2}O in the reaction mixture and the addition of HF all have an important impact on the synthesis of pure STW-type zeolite. GeSi-STW is stable up to 800 °C, and has much higher thermal stability than SU-32 (stable to 400 °C). Co and Cu have been introduced for the first time into STW-zeotype materials. - Graphical abstract: SEM images of GeSi-STW (A and B), Co-STW (C and D) and Cu-STW (E and F). - Highlights: • Pure STW-type germanosilicate materials were hydrothermally synthesized. • The STW-type germanosilicate has high thermal stability up to 800 °C. • Co and Cu have been introduced for the first time in the STW-zeotype materials.

  2. Histological and radiographic evaluations of demineralized bone matrix and coralline hydroxyapatite in the rabbit tibia.

    Science.gov (United States)

    Zhukauskas, Rasa; Dodds, Robert A; Hartill, Caroline; Arola, Travis; Cobb, Ronald R; Fox, Casey

    2010-03-01

    Complex fractures resulting in bone loss or impaired fracture healing remain problematic in trauma and orthopedic surgeries. Many bone graft substitutes have been developed and are commercially available. These products differ in their osteoconductive and osteoinductive properties. Differential enhancement of these properties may optimize the performance of these products for various orthopedic and craniofacial applications. The use of bone graft substitutes offers the ability to lessen the possible morbidity of the harvest site in autografts. The objective of the present study was to compare the ability of two bone graft substitutes, BioSet RT, an allograft demineralized bone matrix formulation, and ProOsteon 500R, a coralline hydroxyapatite, in a rabbit critical tibial defect model. BioSet RT and ProOsteon 500R were implanted into a unicortical proximal metaphyseal tibial defect and evaluated for new bone formation. Samples were analyzed radiographically and histologically at 1 day, 6 weeks, 12 weeks, and 24 weeks post surgery. Both materials were biocompatible and demonstrated significant bone growth and remodeling. At 12 weeks, the BioSet RT implanted sites demonstrated significantly more defect closure and bone remodeling as determined by radiographic analyses with 10 out of 14 defects being completely healed versus 1 out of 14 being completely healed in the ProOsteon 500R implanted sites. At 24 weeks, both materials demonstrated complete closure of the defect as determined histologically. There were no statistical differences in radiographic scores between the two implanted materials. However, there was an observable trend that the BioSet RT material generated higher histological and radiographic scores, although not statistically significant. This study provides evidence that both BioSet RT and ProOsteon 500R are biocompatible and able to induce new bone formation as measured in this rabbit model. In addition, this in vivo study demonstrates the ability of

  3. Computer modelling integrated with micro-CT and material testing provides additional insight to evaluate bone treatments: Application to a beta-glycan derived whey protein mice model.

    Science.gov (United States)

    Sreenivasan, D; Tu, P T; Dickinson, M; Watson, M; Blais, A; Das, R; Cornish, J; Fernandez, J

    2016-01-01

    The primary aim of this study was to evaluate the influence of a whey protein diet on computationally predicted mechanical strength of murine bones in both trabecular and cortical regions of the femur. There was no significant influence on mechanical strength in cortical bone observed with increasing whey protein treatment, consistent with cortical tissue mineral density (TMD) and bone volume changes observed. Trabecular bone showed a significant decline in strength with increasing whey protein treatment when nanoindentation derived Young׳s moduli were used in the model. When microindentation, micro-CT phantom density or normalised Young׳s moduli were included in the model a non-significant decline in strength was exhibited. These results for trabecular bone were consistent with both trabecular bone mineral density (BMD) and micro-CT indices obtained independently. The secondary aim of this study was to characterise the influence of different sources of Young׳s moduli on computational prediction. This study aimed to quantify the predicted mechanical strength in 3D from these sources and evaluate if trends and conclusions remained consistent. For cortical bone, predicted mechanical strength behaviour was consistent across all sources of Young׳s moduli. There was no difference in treatment trend observed when Young׳s moduli were normalised. In contrast, trabecular strength due to whey protein treatment significantly reduced when material properties from nanoindentation were introduced. Other material property sources were not significant but emphasised the strength trend over normalised material properties. This shows strength at the trabecular level was attributed to both changes in bone architecture and material properties.

  4. 组织工程骨材料在运动性骨缺损修复中的评价%Evaluation of materials of bone tissue engineering in athletic bone defects reconstruction

    Institute of Scientific and Technical Information of China (English)

    李华

    2011-01-01

    目的:评价组织工程化人工骨材料的性能和应用,找合理的骨缺损修复材料.方法:以"组织工程,缺损,工骨,米材料" 为中文关键词;以"tissue engineering,bone defect,artificial bone,biological degradation"为英文关键词,用计算机检索1993-01/2009-10相关文章.纳入与有关组织工程相关的文章;排除重复研究或Meta分析类文章.以30篇文献为主,点进行了讨论组织工程纳米级人工骨材料的种类及其性能.结果:可生物降解并具有生物活性的组织工程人工骨材料可作为一种较理想的支架材料应用于骨缺损修复组织工程.修复效果相当或接近自体骨,源充足,无免疫排斥反应,避免取自体骨给患者带来的痛苦和并发症,影响运动员重返赛场,动员患者乐于接受.复合材料人工骨在解除运动员患者的后顾之忧的同时,带来巨大的社会效益.基于纳米羟基磷灰石复合重组人骨形态发生蛋白2制成的支架,但具有理想的生物相容性、生物降解性和较高的亲和性,且能提高了骨诱导活性,够促进新骨的形成.可生物降解并具有生物活性的组织工程人工骨材料在临床使用的初步情况表明,人体生物相容性良好,免疫排斥反应,合情况良好.结论:骨缺损是常见的运动损伤,直为运动损伤研究热点.组织工程化骨缺损修复的研究近年来发展迅速,运动损伤骨缺损修复带来了契机.组织工程复合材料可以发挥不同材料的优势,补单一材料的不足,一种比较理想的支架材料.%OBJECTIVE: To evaluate the disposition and application of tissue-engineered artificial bone materials, in order to find a reasonable repair material for bone defect.METHODS: Taking "tissue engineering, bone defect, artificial bone, nanomaterials" in Chinese, and "tissue engineering, bone defect, artificial bone, biological degradation" in English as search terms, the articles between January 1993 and October 2009were

  5. Development of Nano-biomaterials for Bone Repair

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new kind of nano-biomaterials of nano apatite ( NA ) and polyamide8063 ( PA ) composite was prepared by direct using NA slurry. The experimental results showed that the NA content in the composite was similar to that of natural bone. Interface chemical bonding was formed between NA and PA. The NA keeps the original morphological structure with a crystal size of 10- 30 nm in width by 50- 90 nm in length with a ratio of~ 2.5 and distributed uniformly in the polymer. The synthetic nano-biomaterials could be one of the best bioactive materials for load-bearing bone repair or substitution materials.

  6. A Study on the Meat and Bone Meal or Poultry By-product Meal as Protein Substitutes of Fishmeal in Concentrated Diets for Paralichthys olivaceus

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient (ADC) of Japanese flounder (Paralichthys olivaceus). The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences (P>0.05) in growth performance among the treatments fed with 0%-60% MBM replacement of fishmeal, while the percent weight gain (WG,%), body length gain (BLG, %) and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences (P>0.05) in growth performance and ADC among all treatments fed with the diets with 0%-80% replacements of fishmeal with PBM.

  7. A study on the meat and bone meal or poultry by-product meal as protein substitutes of fishmeal in concentrated diets for Paralichthys olivaceus

    Science.gov (United States)

    Zhu, Wei; Mai, Kangsen; Zhang, Baigang; Hu, Yangjiang; Yu, Yu

    2006-01-01

    A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient (ADC) of Japanese flounder ( Paralichthys olivaceus). The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences ( P>0.05) in growth performance among the treatments fed with 0% 60% MBM replacement of fishmeal, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences ( P>0.05) in growth performance and ADC among all treatments fed with the diets with 0% 80% replacements of fishmeal with PBM.

  8. Structural properties of a bone-ceramic composite as a promising material in spinal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kirilova, I. A., E-mail: IKirilova@mail.ru; Sadovoy, M. A.; Podorozhnaya, V. T., E-mail: VPodorognaya@niito.ru; Taranov, O. S. [Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Novosibirsk (Russian Federation); Klinkov, S. V.; Kosarev, V. F. [Christianovich Institute of Theoretical and Applied Mechanics, SB RAS, Novosibirsk (Russian Federation); Shatskaya, S. S. [Institute of Solid State Chemistry and Mechanochemistry, SB RAS, Novosibirsk (Russian Federation)

    2015-11-17

    The paper describes the results of in vitro tests of composite bone-ceramic implants and procedures for modifying implant surfaces to enhance osteogenesis. Analysis of CBCI ESs demonstrated that they have a porous structure with the mean longitudinal pore size of 70 µm and the mean transverse pore size of 46 µm; surface pores are open, while inner pores are closed. Elemental analysis of the CBCI surface demonstrates that CBCIs are composed of aluminum and zirconium oxides and contain HA inclusions. Profilometry of the CBCI ES surface revealed the following deviations: the maximum deviation of the profile in the sample center is 15 µm and 16 µm on the periphery, while the arithmetical mean and mean square deviations of the profile are 2.65 and 3.4 µm, respectively. In addition, CBCI biodegradation products were pre-examined; a 0.9% NaCl solution was used as a comparison group. Potentially toxic and tissue accumulated elements, such as cadmium, cobalt, mercury, and lead, are present only in trace amounts and have no statistically significant differences with the comparison group, which precludes their potential toxic effects on the macroorganism. Ceramic-based CBCI may be effective and useful in medicine for restoration of the anatomic integrity and functions of the bone tissue.

  9. Adult mesenchymal stem cells for bone and cartilage engineering: effect of scaffold materials

    Directory of Open Access Journals (Sweden)

    A Gigante

    2009-08-01

    Full Text Available Bone marrow is a useful cell source for skeletal tissue engineering approaches. In vitro differentiation of marrow mesenchymal stem cells (MSCs to chondrocytes or osteoblasts can be induced by the addition of specific growth factors to the medium. The present study evaluated the behaviour of human MSCs cultured on various scaffolds to determine whether their differentiation can be induced by cell-matrix interactions. MSCs from bone marrow collected from the acetabulum during hip arthroplasty procedures were isolated by cell sorting, expanded and characterised by a flow cytometry system. Cells were grown on three different scaffolds (type I collagen, type I + II collagen and type I collagen + hydroxyapatite membranes and analysed by histochemistry, immunohistochemistry and spectrophotometry (cell proliferation, alkaline phosphatase activity at 15 and 30 days. Widely variable cell adhesion and proliferation was observed on the three scaffolds. MSCs grown on type I+II collagen differentiated to cells expressing chondrocyte markers, while those grown on type I collagen + hydroxyapatite differentiated into osteoblast-like cells. The study highlighted that human MSCs grown on different scaffold matrices may display different behaviours in terms of cell proliferation and phenotype expression without growth factor supplementation.

  10. Structural properties of a bone-ceramic composite as a promising material in spinal surgery

    Science.gov (United States)

    Kirilova, I. A.; Sadovoy, M. A.; Podorozhnaya, V. T.; Taranov, O. S.; Klinkov, S. V.; Kosarev, V. F.; Shatskaya, S. S.

    2015-11-01

    The paper describes the results of in vitro tests of composite bone-ceramic implants and procedures for modifying implant surfaces to enhance osteogenesis. Analysis of CBCI ESs demonstrated that they have a porous structure with the mean longitudinal pore size of 70 µm and the mean transverse pore size of 46 µm; surface pores are open, while inner pores are closed. Elemental analysis of the CBCI surface demonstrates that CBCIs are composed of aluminum and zirconium oxides and contain HA inclusions. Profilometry of the CBCI ES surface revealed the following deviations: the maximum deviation of the profile in the sample center is 15 µm and 16 µm on the periphery, while the arithmetical mean and mean square deviations of the profile are 2.65 and 3.4 µm, respectively. In addition, CBCI biodegradation products were pre-examined; a 0.9% NaCl solution was used as a comparison group. Potentially toxic and tissue accumulated elements, such as cadmium, cobalt, mercury, and lead, are present only in trace amounts and have no statistically significant differences with the comparison group, which precludes their potential toxic effects on the macroorganism. Ceramic-based CBCI may be effective and useful in medicine for restoration of the anatomic integrity and functions of the bone tissue.

  11. Substitutos ósseos comparados ao enxerto ósseo autólogo em cirurgia ortopédica: revisão sistemática da literatura Bone graft substitutes compared to autologous bone graft in orthopedic surgery: systematic literature review

    Directory of Open Access Journals (Sweden)

    José Luís Amim Zabeu

    2008-03-01

    Full Text Available OBJETIVO: Identificar, a partir de revisão sistematizada da literatura, estudos clínicos com nível de evidência 1 comparando substitutos ósseos ao enxerto autólogo. MÉTODOS: Realizada busca eletrônica de artigos que comparassem o uso do enxerto ósseo autólogo a um substituto ósseo em cirurgia ortopédica. Foram considerados como critérios de elegibilidade ensaios clínicos prospectivos e randomizados em cirurgia ortopédica, com casuística mínima de 20 pacientes, envolvendo ossos da coluna vertebral ou esqueleto apendicular, publicados entre janeiro de 1990 e janeiro de 2006. RESULTADOS: Foram identificados 22 trabalhos, todos em língua inglesa, dos quais cinco compararam enxerto autólogo ao homólogo, sete envolveram uso de proteína morfogenética do tipo 2 (BMP-2, em três foi avaliada a proteína morfogenética do tipo 7 (BMP- 7 e sete utilizaram biocerâmicas, como hidroxiapatita, fosfato tricálcio e sulfato de cálcio. Os resultados mais sugestivos da equivalência com o enxerto autólogo se deram nos trabalhos com BMP-2 em cirurgia da coluna vertebral, embora diversos questionamentos possam ser feitos em relação a estes e aos demais estudos analisados, referentes a métodos e possíveis conflitos de interesses. CONCLUSÃO: Existem poucos estudos com alto nível de evidência que demonstrem a aplicabilidade clínica dos substitutos ósseos atualmente existentes.OBJECTIVE: Based on a systematic literature review, to identify studies with level of evidence 1 to compare bone graft substitutes to autologous bone grafts. METHODS: An electronic survey of papers comparing the use of autologous bone graft and a bone graft substitute in orthopedic surgery was performed. Inclusion criteria considered were prospective and randomized clinical trials in orthopedic surgery, with a minimum of 20 patients, involving spine or appendicular skeleton bones, published between January 1990 and January 2006. RESULTS: 22 papers were identified

  12. Effect of raw material source, processing systems, and processing temperatures on amino acid digestibility of meat and bone meals.

    Science.gov (United States)

    Wang, X; Parsons, C M

    1998-06-01

    Experiments were conducted to evaluate amino acid digestibility of 32 commercial meat and bone meals (MBM) varying in raw material source and produced in seven different commercial cooking systems and at two processing temperatures (low vs high) that differed by 15 to 20 C. Raw material sources included all beef, all pork, mixed species, and high bone MBM. True digestibilities of amino acids were determined using the precision-fed cecectomized rooster assay. Protein efficiency ratio (PER) of six MBM varying greatly in amino acid digestibility was determined with chicks fed 10% CP diets containing a MBM as the sole source of dietary protein. The 32 MBM samples averaged 53.2% CP, 2.73% Lys, 0.6% Cys, and 0.75% Met on a DM basis. True digestibility averaged 82% for Lys, 87% for Met, and 47% for Cys. True digestibilities of amino acids varied substantially among processing systems and temperatures, particularly for Lys and Cys. For example, Lys and Cys digestibility ranged from 68 to 92% and from 20 to 71%, respectively, among different MBM. The higher processing temperature generally yielded lower amino acid digestibility than did the low processing temperature. A smaller, less consistent, effect was observed for raw material source. The PER values of the six selected MBM varied from 0.97 to 2.68 and were highly correlated with amino acid digestibility. These results indicated that very high amino acid digestibility MBM can be produced in commercial rendering systems. However, differences in processing systems and temperatures can cause substantial variability in amino acid digestibilities.

  13. Osteogenic potential of porous {beta}-tricalcium phosphate ({beta}-TCP) combined with cultured bone. Tissue engineered bone using a biodegradable material as a scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Fu, S.; Yamada, Y.; Honda, M.; Ueda, M. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Yoshikawa, T. [Nara Medical Univ. (Japan). First Dept. of Pathology; Hibino, Y.; Hata, K. [Nagoya Univ. (Japan). Dept. of Tissue Engineering; Niimi, A. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Chunichi Hospital (Japan). Dept. of Oral and Maxillofacial Surgery; Okazaki, Y. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Nagoya Univ. (Japan). Dept. of Tissue Engineering

    2001-07-01

    Recently, the tissue engineering approach has widespread attention for regeneration. The present study was undertaken to evaluate whether biodegradable porous {beta}-tricalcium phosphate ({beta}-TCP) can be used as a scaffold for cultured bone marrow cells or not. Marrow cells were obtained from bone shaft of rat femur and cultured in a standard medium for 10 days, then trypsinized to combine cells with ceramics. An additional subculture was done for cells/ceramics composite in a standard medium with the addition of {beta}-glycerophosphate, ascorbic acid and dexamethason. The 20 day subcultured composites were implanted into subcutaneous sites of syngeneic rats. These implants were harvested at 4 and 8 weeks postimplantation, and prepared for the histological analysis. In the histological analysis of composites at 4 weeks postimplantation, active bone formation could be found in the composites. The bone formation was evidenced by active osteoblast lining on the surfaces of bone. At 8 weeks, more extensive bone formation was observed in the composites. These results suggested that beta-TCP could play a role as scaffold of tissueengineered bone derived from marrow cells. (orig.)

  14. Polyphosphate: A Morphogenetically Active Implant Material Serving as Metabolic Fuel for Bone Regeneration.

    Science.gov (United States)

    Müller, Werner E G; Tolba, Emad; Schröder, Heinz C; Wang, Xiaohong

    2015-09-01

    The initial mineralization centers during human bone formation onto osteoblasts are composed of CaCO3 . Those bioseeds are enzymatically formed via carbonic anhydrase(s) in close association with the cell surface of the osteoblasts. Subsequently, the bicarbonate/carbonate anions are exchanged non-enzymatically by inorganic phosphate [Pi ]. One source for the supply of Pi is polyphosphate [polyP] which is a physiological polymer, formed in the osteoblasts as well as in the platelets. The energy-rich acid anhydride bonds within the polyP chain are cleaved by phosphatase(s); during this reaction free-energy might be released that could be re-used, as metabolic fuel, for the maintenance of the steady-state concentrations of the substrates/products during mineralization. Finally it is outlined that polyP, as a morphogenetically active scaffold, is even suitable for 3D cell printing.

  15. A study on the meat and bone meal and poultry by-product meal as protein substitutes of fish meal in practical diets for Litopenaeus vannamei juveniles

    Science.gov (United States)

    Zhu, Wei; Mai, Kangsen; Zhang, Baigang; Wang, Fuzhen; Yu, Yu

    2004-10-01

    A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fish meal in the diets on the growth performance, survival and apparent digestibility coefficients (ADC) of Litopenaeus vannamei. The basal diets were formulated with 22% fish meal and other ingredients which provided about 40% protein and 9% lipid in the diet. The experimental diets included MBM or PBM to replace 0, 20%, 40%, 60% and 80% of total fish meal respectively. All diets were iso-nitrogenous and isocaloric in gross terms. The results showed that there were no significant differences (Pτ;0.05) in growth performance and ADC among the treatments fed with the diets in which 0 60% fish meal had been replaced with MBM, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decreased when the MBM was up to 80% of the fish meal. There were no significant differences (Pτ;0.05) in growth performance and ADC among all the treatments fed with the diets in which 0 80% fish meal had been replaced with PBM.

  16. A Study on the Meat and Bone Meal and Poultry By-product Meal as Protein Substitutes of Fish Meal in Practical Diets for Litopenaeus vannamei Juveniles

    Institute of Scientific and Technical Information of China (English)

    ZHU Wei; MAI Kangsen; ZHANG Baigang; WANG Fuzhen; YU Yu

    2004-01-01

    A study was conducted to evaluate the effects of meat and bone meal(MBM)and poultry by-product meal(PBM)as the replacement of fish meal in the diets on the growth performance, survival and apparent digestibility coefficients(ADC)of Litopenaeus vannamei. The basal diets were formulated with 22% fish meal and other ingredients which provided about 40% protein and 9% lipid in the diet. The experimental diets included MBM or PBM to replace 0, 20%, 40%, 60% and 80% of total fish meal respectively. All diets were iso-nitrogenous and isocaloric in gross terms. The results showed that there were no significant differences(P>0.05)in growth performance and ADC among the treatments fed with the diets in which 0-60% fish meal had been replaced with MBM, while the percent weight gain(WG,%), body length gain(BLG,%)and ADC significantly decreased when the MBM was up to 80% of the fish meal. There were no significant differences(P>0.05)in growth performance and ADC among all the treatments fed with the diets in which 0-80% fish meal had been replaced with PBM.

  17. Substituting complements

    OpenAIRE

    Dari-Mattiacci, G.; Parisi, F.; Heller, M.

    2009-01-01

    The presence of multiple sellers in the provision of (nonsubstitutable) complementary goods leads to outcomes that are worse than those generated by a monopoly (with a vertically integrated production of complements), a problem known in the economic literature as complementary oligopoly and recently popularized in the legal literature as the tragedy of the anticommons. We ask the following question: how many substitutes for each complement are necessary to render the presence of multiple sell...

  18. 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 ...

  19. Biosilica-glass formation using enzymes from sponges [silicatein]: Basic aspects and application in biomedicine [bone reconstitution material and osteoporosis

    Science.gov (United States)

    Wang, Shun-Feng; Wang, Xiao-Hong; Gan, Lu; Wiens, Matthias; Schröder, Heinz C.; Müller, Werner E. G.

    2011-09-01

    In the last 15 years biomineralization, in particular biosilicification (i.e., the formation of biogenic silica, SiO2), has become an exciting source of inspiration for the development of novel bionic approaches, following "Nature as model". Among the silica forming organisms there are the sponges that have the unique property to catalyze their silica skeletons by a specific enzyme termed silicatein. In the present review we summarize the present state of knowledge on silicatein-mediated "biosilica" formation in marine sponges, the involvement of further molecules in silica metabolism and their potential application in biomedicine. Recent advancements in the production of bone replacement material and in the potential use as a component in the treatment of osteoporosis are highlighted.

  20. Tile concrete base materials as substitutes for lead shielding installations diagnostic X-ray; Losetas de materiales con base de hormigon como blindajes sustitutivos del plomo en instalaciones de rayos X de diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Pombar Camean, M.; Pasin, J.; Fuestes-Vazquez, V.; Alonso, E.; Pereira, B.

    2011-07-01

    In this paper we study the damping characteristics in the energy range of medical diagnostic X-ray product X-RAD trade name manufactured by Construction Radiotherapy Techniques (CTRADC) consisting of different composition tile with concrete base, for its characterization as a substitute shielding material lead.

  1. Effect of rapidly resorbable calcium phosphates and a calcium phosphate bone cement on the expression of bone-related genes and proteins in vitro.

    Science.gov (United States)

    Knabe, C; Berger, G; Gildenhaar, R; Meyer, J; Howlett, C R; Markovic, B; Zreiqat, H

    2004-04-01

    The use of biodegradable bone substitutes is advantageous for alveolar ridge augmentation because it avoids second-site surgery for autograft harvesting. This study examines the effect of novel, rapidly resorbable calcium phosphates and a calcium phosphate bone cement on the expression of bone-related genes and proteins by human bone-derived cells (HBDCs) and compares this behavior to that of tricalciumphosphate (TCP). Test materials were alpha-TCP, two materials with a crystalline phase Ca(2)KNa(PO(4))(2) and with a small amorphous portion containing either magnesium potassium phosphate (material denominated GB14) or silica phosphate (material denominated GB9), and a calcium phosphate bone cement (material denominated Biocement D). HBDCs were grown on the substrata for 3, 7, 14, and 21 days, counted, and probed for various mRNAs and proteins (type I collagen, osteocalcin, osteopontin, osteonectin, alkaline phosphatase, and bone sialoprotein). All substrates supported continuous cellular growth for 21 days. In the presence of GB14 and Biocement D specimens cell proliferation was reduced and cell differentiation increased. At day 21, the greatest number of cells was found on GB9 expressing significantly higher levels of bone-related proteins than cells grown on all other surfaces. Because all novel materials facilitated the expression of the osteoblastic phenotype at least as much as TCP and the polystyrene control, these biomaterials can be regarded as excellent candidate bone substitute materials. GB9 induced the highest proliferation and cellular differentiation after 21 days of incubation, suggesting that this material may possess a higher potency for enhancing osteogenesis than TCP.

  2. Collagen for bone tissue regeneration.

    Science.gov (United States)

    Ferreira, Ana Marina; Gentile, Piergiorgio; Chiono, Valeria; Ciardelli, Gianluca

    2012-09-01

    In the last decades, increased knowledge about the organization, structure and properties of collagen (particularly concerning interactions between cells and collagen-based materials) has inspired scientists and engineers to design innovative collagen-based biomaterials and to develop novel tissue-engineering products. The design of resorbable collagen-based medical implants requires understanding the tissue/organ anatomy and biological function as well as the role of collagen's physicochemical properties and structure in tissue/organ regeneration. Bone is a complex tissue that plays a critical role in diverse metabolic processes mediated by calcium delivery as well as in hematopoiesis whilst maintaining skeleton strength. A wide variety of collagen-based scaffolds have been proposed for different tissue engineering applications. These scaffolds are designed to promote a biological response, such as cell interaction, and to work as artificial biomimetic extracellular matrices that guide tissue regeneration. This paper critically reviews the current understanding of the complex hierarchical structure and properties of native collagen molecules, and describes the scientific challenge of manufacturing collagen-based materials with suitable properties and shapes for specific biomedical applications, with special emphasis on bone tissue engineering. The analysis of the state of the art in the field reveals the presence of innovative techniques for scaffold and material manufacturing that are currently opening the way to the preparation of biomimetic substrates that modulate cell interaction for improved substitution, restoration, retention or enhancement of bone tissue function.

  3. Relleno de cavidades óseas en cirugía maxilofacial con materiales autólogos Bone cavity augmentation in maxillofacial surgery using autologous material

    Directory of Open Access Journals (Sweden)

    P. Infante-Cossío

    2007-02-01

    Full Text Available Aunque se han descrito numerosos materiales para rellenar una cavidad ósea, el mejor material sigue siendo el hueso autólogo corticoesponjoso o particulado, que puede formar hueso nuevo por mecanismos de osteogénesis, osteinducción y osteoconducción. El cirujano oral y maxilofacial debe conocer las propiedades biológicas y las características fundamentales de los materiales autólogos, las diferentes técnicas de obtención y sus aplicaciones clínicas. Como zonas donantes se emplean preferentemente las intraorales, el filtro de hueso y los raspadores para pequeños defectos, y el hueso ilíaco, tibia o calota cuando se requiere más cantidad. No existen estudios concluyentes respecto a la asociación de injertos óseos con membranas. La combinación de injertos autólogos con otros materiales de relleno, ha desembocado en múltiples estudios, sin que se puedan establecer conclusiones definitivas por el momento. El hueso autólogo es de elección para el relleno de cavidades óseas, ya que es útil para dar solución a variadas situaciones clínicas de forma simple, rápida y segura.Although a large number of materials have been described for augmenting bone cavities, the best material is still autologous cortical-cancellous bone or bone chip, which can form new bone through osteogenesis, osteoinduction and osteoconduct ion mechanisms. The oral and maxillofacial surgeon needs to be familiar with the biological properties and the fundamental characteristics of autologous material, the different techniques for obtaining it and its clinical application. Donor sites should preferably be intraoral. Bone filters and scrapers should be used for small defects, and the iliac, tibial or calvaria bones [should be used] when more quantity is required. There are no conclusive studies with regard to combining bone grafts with membranes. The combination of autologous grafts with other augmentation material has led to multiple studies, although

  4. Material properties and in vitro biocompatibility of a newly developed bone cement

    Directory of Open Access Journals (Sweden)

    Elke Mitzner

    2009-01-01

    Full Text Available In this study mechanical properties and biocompatibility (In Vitro of a new bone cement were investigated. A new platform technology named COOL is a variable composite of dissolved, chemically modified PMMA and different bioceramics. COOL cures at body temperature via a classical cementation reaction. Compressive strengths ranging from 3.6 ± 0.8 to 62.8 ± 1.3 MPa and bending strengths ranging from 9.9 ± 2.4 to 26.4 ± 3.0 MPa were achieved with different COOL formulations. Porosity varied between 31 and 43%. Varying the components of each formulation mechanical properties and porosity could be adjusted. In Vitro biocompatibility studies with primary human osteoblasts (pHOB in direct contact with different COOL formulations, did not reveal any signs of toxicity. In contrast to Refobacin® R, cells incubated with COOL showed similar density, viability and ALP activity compared to control, if specimen were added immediately to the cell monolayer after preparation. In conclusion, COOL has promising mechanical properties in combination with high biocompatibility In Vitro and combines different advantages of both CPCs and PMMA cements by avoiding some of the respective shortcomings.

  5. [Study of regeneration in periodontal tissue after implantation of bone ceramic and collagen gel compound materials. Evaluation of histopathological finding and autoradiography].

    Science.gov (United States)

    Miyamoto, Y; Hayashi, H; Kamoi, K

    1989-12-01

    The aim of this study is to determine the process of periodontal tissue regeneration and the metabolic activity of osteoblasts after implantation of bone ceramic and collagen gel compound materials (BC). Bone defects were artificially prepared in the alveolar septa of the bilateral upper first and second molars of Wistar rats. Subsequently, BC were implanted into the defective sites on the left side, and the gingival flaps were closed. At the defective sites on the right side, as a control, gingival flaps were closed without implantation. Rats were sacrificed 1, 3, 5, 7 or 14 weeks after implantation, and prepared tissue sections were observed both pathologically and autoradiographically using 3H-Proline. The results obtained were as follows: Pathological Findings One week after BC implantation, inflammatory cellular infiltration of the surrounding gingival connective tissue was relatively mild. Three weeks after implantation, BC were present in fibrous connective tissues, and some directly bound to the marices of regenerated bone. Observation 5 weeks after implantation revealed that BC had become embedded in the regenerated bone matrices and that there was giant cell reaction to foreign bodies at the margin of BC located in connective tissue. BC were directly bound to the regenerated bone matrices without intermediary fibrous tissues 7 and 14 weeks after implantation. Connective tissues showed high grade regeneration of collagen fiber bundles, in an arrangement that tended to be fixed in mesial and distal directions. Autoradiographic Findings There was no uptake of 3H-Proline into the regenerated bone matrices or the gingival connective tissue surrounding BC, while uptake of 3H-Proline into the entire area around the root apex and in the vicinity of the alveolar septum was observed with time (weeks) after BC implantation. These results suggest that BC provide nuclei for bone regeneration through inclusion in newly-generated periodontal bone tissue, although it is

  6. Synthesis of amino, azido, nitro, and nitrogen-rich azole-substituted derivatives of 1H-benzotriazole for high-energy materials applications.

    Science.gov (United States)

    Srinivas, Dharavath; Ghule, Vikas D; Tewari, Surya P; Muralidharan, Krishnamurthi

    2012-11-19

    The amino, azido, nitro, and nitrogen-rich azole substituted derivatives of 1H-benzotriazole have been synthesized for energetic material applications. The synthesized compounds were fully characterized by (1)H and (13)C NMR spectroscopy, IR, MS, and elemental analysis. 5-Chloro-4-nitro-1H-benzo[1,2,3]triazole (2) and 5-azido-4,6-dinitro-1H-benzo[1,2,3]triazole (7) crystallize in the Pca2(1) (orthorhombic) and P2(1)/c (monoclinic) space group, respectively, as determined by single-crystal X-ray diffraction. Their densities are 1.71 and 1.77 g cm(-3), respectively. The calculated densities of the other compounds range between 1.61 and 1.98 g cm(-3). The detonation velocity (D) values calculated for these synthesized compounds range from 5.45 to 8.06 km s(-1), and the detonation pressure (P) ranges from 12.35 to 28 GPa.

  7. Treatment concepts for the posterior maxilla and mandible: short implants versus long implants in augmented bone

    Science.gov (United States)

    2017-01-01

    The aim of this narrative review is to describe treatment options for the posterior regions of the mandible and the maxilla, comparing short implants vs. longer implants in an augmented bone. The dental literature was screened for treatment options enabling the placement of dental implants in posterior sites with a reduced vertical bone height in the maxilla and the mandible. Short dental implants have been increasingly used recently, providing a number of advantages including reduced patient morbidity, shorter treatment time, and lower costs. In the posterior maxilla, sinus elevation procedures were for long considered to be the gold standard using various bone substitute materials and rendering high implant survival rates. More recently, implants were even placed without any further use of bone substitute materials, but the long-term outcomes have yet to be documented. Vertical bone augmentation procedures in the mandible require a relatively high level of surgical skill and allow the placement of standard-length dental implants by the use of autogenous bone blocks. Both treatment options, short dental implants, and standard-length implants in combination with vertical bone augmentation procedures, appear to result in predictable outcomes in terms of implant survival rates. According to recent clinical studies comparing the therapeutic options of short implants vs. long implants in augmented bone, the use of short dental implants leads to a number of advantages for the patients and the clinician. PMID:28261519

  8. Treatment concepts for the posterior maxilla and mandible: short implants versus long implants in augmented bone.

    Science.gov (United States)

    Thoma, Daniel Stefan; Cha, Jae-Kook; Jung, Ui-Won

    2017-02-01

    The aim of this narrative review is to describe treatment options for the posterior regions of the mandible and the maxilla, comparing short implants vs. longer implants in an augmented bone. The dental literature was screened for treatment options enabling the placement of dental implants in posterior sites with a reduced vertical bone height in the maxilla and the mandible. Short dental implants have been increasingly used recently, providing a number of advantages including reduced patient morbidity, shorter treatment time, and lower costs. In the posterior maxilla, sinus elevation procedures were for long considered to be the gold standard using various bone substitute materials and rendering high implant survival rates. More recently, implants were even placed without any further use of bone substitute materials, but the long-term outcomes have yet to be documented. Vertical bone augmentation procedures in the mandible require a relatively high level of surgical skill and allow the placement of standard-length dental implants by the use of autogenous bone blocks. Both treatment options, short dental implants, and standard-length implants in combination with vertical bone augmentation procedures, appear to result in predictable outcomes in terms of implant survival rates. According to recent clinical studies comparing the therapeutic options of short implants vs. long implants in augmented bone, the use of short dental implants leads to a number of advantages for the patients and the clinician.

  9. Material Rhetoric: Spreading Stones and Showing Bones in the Study of Prehistory

    NARCIS (Netherlands)

    Van Reybrouck, D.; de Bont, R.; Rock, J.

    2009-01-01

    Since the linguistic turn, the role of rhetoric in the circulation and the popular representation of knowledge has been widely accepted in science studies. This article aims to analyze not a textual form of scientific rhetoric, but the crucial role of materiality in scientific debates. It introduces

  10. Bone cysts: unicameral and aneurysmal bone cyst.

    Science.gov (United States)

    Mascard, E; Gomez-Brouchet, A; Lambot, K

    2015-02-01

    Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy.

  11. Analysis of stress on mucosa and basal bone underlying complete dentures with different reliner material thicknesses: a three-dimensional finite element study.

    Science.gov (United States)

    Lima, J B G; Orsi, I A; Borie, E; Lima, J H F; Noritomi, P Y

    2013-10-01

    The aim of this study was to determine the optimal thickness of reliner material that provides the least amount of stress on thin mucosa and supporting bone in patients with complete removable dentures using a three-dimensional finite element analyses. The model was obtained from two CT scans of edentulous mandibles with dentures supported by the alveolar ridge. After virtual reconstruction, the three-dimensional models were exported to the solidworks cad software and divided into six groups based on the thickness of the reliner material as follows: (i) without material, (ii) 0·5 mm, (iii) 1 mm, (iv) 1·5 mm, (v) 2 mm and (vi) 2·5 mm. The applied load was 60 N and perpendicular to the long axis of the alveolar ridge of all the prosthetic teeth, and the mucosal thickness used was 1 mm. The analyses were based on the maximum principal stress in the fibromucosa and the minimum principal stress in the basal bone. Stress concentration was observed in the anterior zone of the mandible in the mucosa and in the bone. The maximum and minimum principal stress in the mucosa and bone, respectively, decreased, whereas the thickness of the reliner material increased until 2 mm, which transmitted the lowest stress, compared with the control. Reliner materials with a thickness of 2·5 mm showed higher stress values than those with a thickness of 2 mm. In conclusion, reliner material with a thickness of 2 mm transmitted the lowest amount of stress to the mucosa and bone in 1 mm of mucosa thickness.

  12. The Impact of Aluminum and Iron Substitution on the Structure and Electrochemistry of Li[Ni0.4Co0.2-yMyMn0.4]O2 Materials

    Energy Technology Data Exchange (ETDEWEB)

    WIlcox, James D.; Rodriguez, Efrain E.; Doeff, Marca M.

    2009-07-23

    Li[Ni0.4Co0.2-yMyMn0.4]O2 (0<_y<_0.2) (M=Al) and Li[Ni0.4Co0.15Fe0.05Mn0.4]O2 compounds were prepared in order to investigate the effect of replacement of all or part of the cobalt on the structural and electrochemical properties. The impact of substitution on the structure has been examined by both x-ray and neutron diffraction experiments. The incorporation of aluminum has minimal effect on the anti-site defect concentration, but leads to structural changes that affect electrochemical performance. The most important effect is an opening of the lithium slab dimension upon substitution, which results in improved rate performance compared to the parent compound. In contrast, the lithium slab dimension is not affected by iron substitution and no rate enhancement effect is observed. The cycling stability of aluminum containing materials is superior to both the parent material and iron-substituted materials.

  13. 脱蛋白松质骨作为异种骨移植材料的修复作用%Repair effect of deproteinised cancellous bone as xenogeneic bone graft material

    Institute of Scientific and Technical Information of China (English)

    高春阳; 姜宏春; 金春明

    2011-01-01

    BACKGROUND: Unequal size, mutual communication, and open pore network structure can be seen in cancellous bone treated with deproteinization. Its inorganic component is hydroxyapatite, and the organic component is collagen, which has a good mechanical property and biocompatibility. It may be a new type of bone graft material.OBJECTIVE: To study the properties of xenogeneic deproteinised cancellous bone being carrier of bone tissue engineering in bone fusion.METHODS: Taking “xenogeneic deproteinised cancellous bone, bone fusion, carrier” in Chinese as search terms, the articles from January 1998 to December 2009 in VIP database, CNKI database, Pubmed database were retrieved by computer. The relevant literatures were included, the literature of irrelevant purpose and repetitive content were excluded, and 33 of them were involved for further analysis.RESULTS AND CONCLUSION: Compared with synthetic bone material, animal bones have similar biomaterial structure, modeling, excellent cell attachment, and cell growth and proliferation environment. However, the compatibility of bone tissue is poor, because of the differences in species when xenogeneic deproteinised cancellous bone transplantation, and gravis immune rejection, the key question is implantation of immune problems. How to overcome immunogenicity, xenogeneic deproteinised cancellous bone is a good carrier of bone tissue engineering, which can provide a stable environment for revascularization and differentiation of osteoblasts.%背景:采用脱蛋白处理后的松质骨可见大小不等、相互交通、开放孔隙的网架结构,其无机成分为羟基磷灰石,有机成分为胶原,力学性能保存良好,有良好的细胞相容性,可能是一种新型骨移植材料.目的:介绍异种脱蛋白松质骨作为骨组织工程载体的性能,以及其用于骨融合的作用.方法:分别以"异种脱蛋白松质骨、骨融合、载体",为检索词,应用计算机检索重庆

  14. Lanthanum-silicon-substituted hydroxyapatite: Mechanochemical synthesis and prospects for medical applications

    Science.gov (United States)

    Chaikina, M. V.; Komarova, E. G.; Sharkeev, Yu. P.; Bulina, N. V.; Prosanov, I. Yu.

    2016-08-01

    The paper presents the results of mechanochemical synthesis of hydroxyapatite (HAP) with simultaneous substitutions of lanthanum (La3+) for calcium ions and silicate ((SiO4)4--group) for the phosphate group with the substituent concentrations in the range 0.2-2.0 mol per HAP mol. The use of Si-substituted HAP as a coating material promotes accelerated osteosynthesis and osteointegration of implants into the bone tissue. The replacement of calcium ions by La3+ in the HAP structure plays an antimicrobial role preventing inflammatory processes. Annealing-induced variations in the lattice parameters of synthesized samples indicate the substituent incorporation into the HAP structure. It is known that complex compounds with lanthanides are used for cancer chemotherapy. In particular, La plays a key role in the course of treatment of injured defects of bone tissue. In addition, La-substituted HAP can be used for filling bone defects and coating implants in postoperational areas affected by bone cancer.

  15. Geometric and mechanical properties evaluation of scaffolds for bone tissue applications designing by a reaction-diffusion models and manufactured with a material jetting system

    Directory of Open Access Journals (Sweden)

    Marco A. Velasco

    2016-10-01

    Full Text Available Scaffolds are essential in bone tissue engineering, as they provide support to cells and growth factors necessary to regenerate tissue. In addition, they meet the mechanical function of the bone while it regenerates. Currently, the multiple methods for designing and manufacturing scaffolds are based on regular structures from a unit cell that repeats in a given domain. However, these methods do not resemble the actual structure of the trabecular bone which may work against osseous tissue regeneration. To explore the design of porous structures with similar mechanical properties to native bone, a geometric generation scheme from a reaction-diffusion model and its manufacturing via a material jetting system is proposed. This article presents the methodology used, the geometric characteristics and the modulus of elasticity of the scaffolds designed and manufactured. The method proposed shows its potential to generate structures that allow to control the basic scaffold properties for bone tissue engineering such as the width of the channels and porosity. The mechanical properties of our scaffolds are similar to trabecular tissue present in vertebrae and tibia bones. Tests on the manufactured scaffolds show that it is necessary to consider the orientation of the object relative to the printing system because the channel geometry, mechanical properties and roughness are heavily influenced by the position of the surface analyzed with respect to the printing axis. A possible line for future work may be the establishment of a set of guidelines to consider the effects of manufacturing processes in designing stages.

  16. Realization and testing of multi-material 3D printer for bone scaffold fabrication

    Science.gov (United States)

    Whulanza, Yudan; Hidayaturrahmi, Pretty; Kurniawati, Tri; AJ, Rahyussalim

    2017-02-01

    This research realized 3D constructs by integrating more than one material with multi fabrication system within a single session. A commercial rapid prototyping system, RepRap MendelTM, is modified so that it enables us to realize microenvironment composed of multi materials namely gelatin hydrogel and polylactic acid. Firstly, the session is preceded by realization of 3D scaffold using polylactic acid (PLA) with porosity and modulus elasticity as characterized. Later, the gelatin extrusion took place to seed the cellular in determined spatial arrangement. The results show that our apparatus able to realized scaffold that using PLA as matrix filled with gelatin that act as cell carrier in future application. The scaffolds have porous around 0.25 mm2 porosity with a modulus of elasticity around 160 MPa.

  17. Biocompatibility of Tri-block Bone-matrix Material in vitro

    Institute of Scientific and Technical Information of China (English)

    DUAN Deyu; ZHENG Qixin; HAO Jie; GUO Xiaodong

    2007-01-01

    To evaluate the biocompatibility of poly(lactic acid/glycolic acid/ asparagic acid-copolyethylene glycol)(PLGA-[ASP-PEG]) tri-block copolymer in vitro, L929 fibroblast was co-cultured with the copolymer for cytotoxicity, hemolysis and pyrogen tests. And, compared with PLGA, the adhesiveness rate of the copolymer was calculated. The experimental results show that the toxicity gradation of the material was 0-1; L929 fibroblasts had a good cell morphology and proliferated rapidly on the surface of the material; hemolysis ratio was 3.08%; there was no pyrogen reaction. The adhesiveness of PLGA-[ASP-PEG] was better than that of the PLGA's(P<0.05). The results confirm that the PLGA-[ASP-PEG] has a good biocompatibility.

  18. Enhanced electrochemical performance and manganese redox activity of LiFe0.4Mn0.6PO4 by iodine anion substitution as cathode material for Li-ion battery

    Science.gov (United States)

    Sin, Byung Cheol; Singh, Laxman; An, JiEun; Lee, Hansol; Lee, Hyung-il; Lee, Youngil

    2016-05-01

    For the first time, an attempt has been made for the possible augmentation and exploration of iodine substitution into LiFe0.4Mn0.6PO4 (LFMP) material is assessed as a cathode material for lithium ion batteries. Iodine substituted LiFe0.4Mn0.6(PO4)1-xIx (LFMPI, x = 0, 0.01, 0.015, and 0.02) have been synthesized by a solid-state reaction without any external carbon source. X-ray diffraction shows that the LFMP and LFMPI cathode materials have formed the same single crystalline phase; the values of lattice parameters and unit cell volume have been insignificantly changed by I- anion substitution. Uniformly distributed grains of the LFMPI samples with grain sizes in the range of 250 nm to 0.9 μm have been obtained by scanning electron microscopy. X-ray photoelectron spectroscopy for the LFMPI with x = 0.02 have clearly observed at 619.5 and 630.7 eV for I 3d5/2 and I 3d3/2, respectively. The electrochemical properties of the pure LFMP cathode material have been compared with those of I- anion substituted LFMPI samples. LFMPI with x = 0.015 has delivered the highest discharge capacity of 141.5 mAh g-1 at 0.1C, and LFMPI with x = 0.01 has 102.1 mAh g-1 at high rate of 3C. Iodine substituted LFMPI have demonstrated improved electrochemical properties with excellent reversible cycling.

  19. 重组人工骨修复实验性骨缺损影像学评价%Imaginological study on resombinant artificial bone substitute for experimental bone defects

    Institute of Scientific and Technical Information of China (English)

    宋会平; 刘强; 原林; 李宝兴

    2006-01-01

    [目的]探讨重组人胰岛素样生长因子-1(recombinant human insulinlike growth factor-1,rhIGF-1)/珊瑚羟基磷灰石(coralline hydroxyapatite,CHA)/自体红骨髓(autogeneous red bone marrow,ARBM)复合修复骨缺损的能力.[方法]成年中国家兔54只,随机分为3组,制成双侧桡骨中段11 mm骨-骨膜全层缺损模型,每组18只,每组动物左右两侧缺损分别随机植入2种不同材料:1组两侧分别植入材料A(CHA/ARBM/rhIGF-1)和B(CHA/ARBM);2组植入C(CHA/rhIGF-1)和D(CHA);3组植入E(自体皮质骨)和F(缺损旷置).术后行大体、X线(2、4、8、12周)和99mTc-MDP骨扫描(12周)观察.[结果]A组X线片显示桥接骨痂生长良好,12周时缺损修复.12周99mTc-MDP骨显像示A和E组修复区高度核浓聚.[结论]CHA/ARBM/rhIGF-1重组人工骨移植可协同实现骨传导、骨诱导和骨再生作用,促进骨缺损重建.

  20. Influence of rhBMP-2 on rat bone marrow stromal cells cultured on titanium fiber mesh.

    NARCIS (Netherlands)

    Vehof, J.W.M.; Ruijter, J.E. de; Spauwen, P.H.M.; Jansen, J.A.

    2001-01-01

    Titanium (Ti) fiber mesh is a candidate scaffold material for the creation of bone graft substitutes (BGS). Two densities (3.54 x 10(4) cells/cm(2) [LD or low density] and 3.54 x 10(5) cells/cm(2) [HD or high density]) of rat bone marrow stromal cells were seeded on Ti-fiber mesh discs. Cells were c

  1. Research trends in biomimetic medical materials for tissue engineering: 3D bioprinting, surface modification, nano/micro-technology and clinical aspects in tissue engineering of cartilage and bone.

    Science.gov (United States)

    Chen, Cen; Bang, Sumi; Cho, Younghak; Lee, Sahnghoon; Lee, Inseop; Zhang, ShengMin; Noh, Insup

    2016-01-01

    This review discusses about biomimetic medical materials for tissue engineering of bone and cartilage, after previous scientific commentary of the invitation-based, Korea-China joint symposium on biomimetic medical materials, which was held in Seoul, Korea, from October 22 to 26, 2015. The contents of this review were evolved from the presentations of that symposium. Four topics of biomimetic medical materials were discussed from different research groups here: 1) 3D bioprinting medical materials, 2) nano/micro-technology, 3) surface modification of biomaterials for their interactions with cells and 4) clinical aspects of biomaterials for cartilage focusing on cells, scaffolds and cytokines.

  2. Combined micro computed tomography and histology study of bone augmentation and distraction osteogenesis

    Science.gov (United States)

    Ilgenstein, Bernd; Deyhle, Hans; Jaquiery, Claude; Kunz, Christoph; Stalder, Anja; Stübinger, Stefan; Jundt, Gernot; Beckmann, Felix; Müller, Bert; Hieber, Simone E.

    2012-10-01

    Bone augmentation is a vital part of surgical interventions of the oral and maxillofacial area including dental implantology. Prior to implant placement, sufficient bone volume is needed to reduce the risk of peri-implantitis. While augmentation using harvested autologous bone is still considered as gold standard, many surgeons prefer bone substitutes to reduce operation time and to avoid donor site morbidity. To assess the osteogenic efficacy of commercially available augmentation materials we analyzed drill cores extracted before implant insertion. In younger patients, distraction osteogenesis is successfully applied to correct craniofacial deformities through targeted bone formation. To study the influence of mesenchymal stem cells on bone regeneration during distraction osteogenesis, human mesenchymal stem cells were injected into the distraction gap of nude rat mandibles immediately after osteotomy. The distraction was performed over eleven days to reach a distraction gap of 6 mm. Both the rat mandibles and the drill cores were scanned using synchrotron radiation-based micro computed tomography. The three-dimensional data were manually registered and compared with corresponding two-dimensional histological sections to assess bone regeneration and its morphology. The analysis of the rat mandibles indicates that bone formation is enhanced by mesenchymal stem cells injected before distraction. The bone substitutes yielded a wide range of bone volume and degree of resorption. The volume fraction of the newly formed bone was determined to 34.4% in the computed tomography dataset for the augmentation material Geistlich Bio-Oss®. The combination of computed tomography and histology allowed a complementary assessment for both bone augmentation and distraction osteogenesis.

  3. In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile

    Directory of Open Access Journals (Sweden)

    Bronckers Antonius LJJ

    2006-02-01

    Full Text Available Abstract Background Polymethyl-methacrylate (PMMA beads releasing antibiotics are used extensively to treat osteomyelitis, but require surgical removal afterwards because they do not degrade. Methods As an alternative option, this report compares the in vitro gentamicin release profile from clinically used, biodegradable carrier-materials: six injectable cements and six granule-types. Cement cylinders and coated granules containing 3% gentamicin were submerged in dH2O and placed in a 48-sample parallel drug-release system. At regular intervals (30, 90, 180 min. and then every 24 h, for 21 days, the release fluid was exchanged and the gentamicin concentration was measured. The activity of released gentamicin was tested on Staphylococcus aureus. Results All combinations showed initial burst-release of active gentamicin, two cements had continuous-release (17 days. The relative release of all cements (36–85% and granules (30–62% was higher than previously reported for injectable PMMA-cements (up to 17% and comparable to other biodegradable carriers. From the cements residual gentamicin could be extracted, whereas the granules released all gentamicin that had adhered to the surface. Conclusion The high release achieved shows great promise for clinical application of these biodegradable drug-carriers. Using the appropriate combination, the required release profile (burst or sustained may be achieved.

  4. Teeth and bones: applications of surface science to dental materials and related biomaterials

    Science.gov (United States)

    Jones, F. H.

    2001-05-01

    Recent years have seen a considerable upsurge in publications concerning the surface structure and chemistry of materials with biological or biomedical applications. Within the body, gas-solid interactions become relatively less significant and solid-liquid or solid-solid interfaces dominate, providing new challenges for the surface scientist. The current paper aims to provide a timely review of the use of surface analysis and modification techniques within the biomaterials field. A broad overview of applications in a number of related areas is given with particular attention focusing on those materials commonly encountered in dentistry and oral or maxillofacial implantology. Several specific issues of current interest are discussed. The interaction between synthetic and natural solids, both in the oral environment and elsewhere in the body is important in terms of adhesion, related stresses and strains and ultimately the longevity of a dental restoration, biomedical implant, or indeed the surrounding tissue. Exposure to body fluids, of course, can also affect stability, leading to the degradation or corrosion of materials within the body. Whilst this could potentially be harmful, e.g., if cytotoxic elements are released, it may alternatively provide a route to the preferential release of beneficial substances. Furthermore, in some cases, the controlled disintegration of a biomaterial is desirable, allowing the removal of an implant, e.g., without the need for further surgery. The presence of cells in the immediate bioenvironment additionally complicates the situation. A considerable amount of current research activity is targeted at the development of coatings or surface treatments to encourage tissue growth. If this is to be achieved by stimulating enhanced cell productivity, determination of the relationship between cell function and surface composition is essential.

  5. Bonelike/PLGA hybrid materials for bone regeneration : preparation route and physicochemical characterisation

    OpenAIRE

    Oliveira, Joaquim M.; Miyazaki, T; Lopes, M A; Ohtsuki, C.; Santos,J.D.

    2005-01-01

    Bonelike R /PLGA hybrid materials have been developed using γ -MPS as silane-coupling agent between the inorganic and organic phases for controlled drug delivery applications. Silanization showed to be more effective when cyclohexane was used as a non-polar solvent (nP method) due to a chemical interaction between Bonelike R and the silane film, while by using a 95/5 (V/V) methanol/water as a polar solvent (P method), a much thinner film was achieved. Functional groups of PL...

  6. Intrinsic material property differences in bone tissue from patients suffering low-trauma osteoporotic fractures, compared to matched non-fracturing women.

    Science.gov (United States)

    Vennin, S; Desyatova, A; Turner, J A; Watson, P A; Lappe, J M; Recker, R R; Akhter, M P

    2017-04-01

    Osteoporotic (low-trauma) fractures are a significant public health problem. Over 50% of women over 50yrs. of age will suffer an osteoporotic fracture in their remaining lifetimes. While current therapies reduce skeletal fracture risk by maintaining or increasing bone density, additional information is needed that includes the intrinsic material strength properties of bone tissue to help develop better treatments, since measurements of bone density account for no more than ~50% of fracture risk. The hypothesis tested here is that postmenopausal women who have sustained osteoporotic fractures have reduced bone quality, as indicated with measures of intrinsic material properties compared to those who have not fractured. Transiliac biopsies (N=120) were collected from fracturing (N=60, Cases) and non-fracturing postmenopausal women (N=60, age- and BMD-matched Controls) to measure intrinsic material properties using the nano-indentation technique. Each biopsy specimen was embedded in epoxy resin and then ground, polished and used for the nano-indentation testing. After calibration, multiple indentations were made using quasi-static (hardness, modulus) and dynamic (storage and loss moduli) testing protocols. Multiple indentations allowed the median and variance to be computed for each type of measurement for each specimen. Cases were found to have significantly lower median values for cortical hardness and indentation modulus. In addition, cases showed significantly less within-specimen variability in cortical modulus, cortical hardness, cortical storage modulus and trabecular hardness, and more within-specimen variability in trabecular loss modulus. Multivariate modeling indicated the presence of significant independent mechanical effects of cortical loss modulus, along with variability of cortical storage modulus, cortical loss modulus, and trabecular hardness. These results suggest mechanical heterogeneity of bone tissue may contribute to fracture resistance

  7. Treatment of osteonecrosis of femoral head with BMSCs-seeded bio-derived bone materials combined with rhBMP-2 in rabbits

    Institute of Scientific and Technical Information of China (English)

    XIAO Zeng-ming; JIANG Hua; ZHAN Xin-li; WU Zhen-guo; ZHANG Xing-lin

    2008-01-01

    Objective: To evaluate the effect of autologous bone marrow mesenchymal stem cells (BMSCs) seeded bio-derived bone materials (BBM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in repairing defect of osteonecrosis of femoral head (ONFH). Methods: Early-stage osteonecrosis in the left hip was induced in 36 adult New Zealand white rabbits (provided by the Animal Center of Guangxi Medical University, Nanning, China) after core decompression and delivery of liquid nitrogen into the femoral head. Then the animals were divided into three groups according to the type of implants for bone repair: 12 rabbits with nothing (GroupⅠ, the blank control group), 12 with BBM combined with rhBMP-2 (Group Ⅱ), and 12 with BMSCs-seeded BBM combined with rhBMP-2 (Group Ⅲ). At 4, 8, and 12 weeks after surgery, X-ray of the femoral head of every 4 rabbits in each group was taken, and then they were killed and the femoral heads were collected at each time point, respectively. Gross observation was made on the femoral heads. After hematoxylin and eosin staining, Lane-sandhu scores of X-ray and bone densitometry were calculated and the histomorphometric measurements were made for the new bone trabeculae. Results: At 12 weeks after surgery, two femoral heads collapsed in GroupⅠ, but none in Group Ⅱor Group Ⅲ. X-ray examination showed that the femoral heads in Group Ⅰ had defect shadow or collapsed while those in Group Ⅱ had a low density and those in Group Ⅲ presented with a normal density. Histologically, the defects of femoral heads were primarily filled with no new bone but fibrous tissues in Group Ⅰ. In contrast, new bone regeneration and fibrous tissues occurred in Group Ⅱ and only new bone regeneration occurrd in Group Ⅲ. Lane-sandhu scores of X-ray, bone mineral density and rate of new bone in trabecular area in Group Ⅲ were higher signifIcantly than those of the other two groups. Conclusions: Our findings indicate a superior choice of

  8. Mimicking the nanostructure of bone matrix to regenerate bone

    Directory of Open Access Journals (Sweden)

    Robert Kane

    2013-11-01

    Full Text Available Key features of bone tissue structure and composition are capable of directing cellular behavior toward the generation of new bone tissue. Bone tissue, as well as materials derived from bone, have a long and successful history of use as bone grafting materials. Recent developments in design and processing of synthetic scaffolding systems has allowed the replication of the bone's desirable biological activity in easy to fabricate polymeric materials with nano-scale features exposed on the surface. The biological response to these new tissue-engineering scaffold materials oftentimes exceeds that seen on scaffolds produced using biological materials.

  9. AN EXPERIMENTAL STUDY ON RECOMBINANT ARTIFICIAL BONE SUBSTITUTE FOR REPAIRING SEGMENTAL BONE DEFECT IN RABBITS%重组人工骨移植修复节段性骨缺损的实验研究

    Institute of Scientific and Technical Information of China (English)

    宋会平; 刘强; 王志强; 李钢; 张立峰; 彭晨

    2005-01-01

    目的探讨重组人胰岛素样生长因子-1(recombinant human insulin-like growth factor 1,rhIGF-1)/珊瑚羟基磷灰石(coralline hydroxyapatite,CHA)/自体红骨髓(autogeneous red bone marrow ,ARBM)复合构建重组人工骨修复骨缺损的能力. 方法成年中国家兔54只,随机分为3组,每组18只.制成双侧桡骨干11 mm骨-骨膜全层缺损模型,每组动物双侧缺损分别随机植入两种不同材料,形成自体对照的实验组和对照组.1组:实验组(A组,植入CHA/ARBM/rhIGF-1)和对照组(B组,植入CHA/ARBM);2组:实验组(C组,植入CHA/ rhIGF-1)和对照组(D组,植入CHA);3组:实验组(E组,植入取自对侧相应缺损骨段的自体骨)和对照组(F组,缺损旷置).于术后2、4、8和12周行X线片观察、计算机图像分析、组织学观察和生物力学检测,比较各组修复骨缺损能力. 结果 A组在各时间点X线片及计算机图像分析均优于其它各组,差异有统计学意义(P0.05),但显著优于其它各组(P0.05),成骨效果低于A、B和E组.12周时F组缺损未修复. 结论 CHA/ARBM/rhIGF-1重组后可协同实现骨再生、骨传导和骨诱导三重促成骨功效,可替代自体骨移植,成为一种新型的复合活性人工骨.

  10. Factor substitution in nursing homes.

    Science.gov (United States)

    Cawley, John; Grabowski, David C; Hirth, Richard A

    2006-03-01

    This paper studies factor substitution in one important sector: the nursing home industry. Specifically, we measure the extent to which nursing homes substitute materials for labor when labor becomes relatively more expensive. From a policy perspective, factor substitution in this market is important because materials-intensive methods of care are associated with greater risks of morbidity and mortality among nursing home residents. Studying longitudinal data from 1991 to 2000 on nearly every nursing home in the United States, we use the method of instrumental variables (IV) to address measurement error in nursing home wages. The results from the IV models yield evidence of factor substitution: higher nursing home wages are associated with greater use of psychoactive drugs and lower quality.

  11. Mechanical properties and in vitro cellular behavior of zinc-containing nano-bioactive glass doped biphasic calcium phosphate bone substitutes.

    Science.gov (United States)

    Badr-Mohammadi, Mohammad-Reza; Hesaraki, Saeed; Zamanian, Ali

    2014-01-01

    In the present study, different amounts (0.5-5 wt%) of a sol gel-derived zinc-containing nano-bioactive glass (NBG-Zn) powder were added to biphasic calcium phosphate (BCP). The mixtures were sintered at 1,100-1,300 °C and physical characteristics, mechanical properties, phase composition and morphology of them were studied. The samples were also soaked in human blood plasma for 15 days to evaluate variations in their surface morphologies. Rat calvarium-derived osteoblastic cells were seeded on tops of various samples and cell adhesion, proliferation, and alkaline phosphatase activity were evaluated at different culturing periods. The maximum bending strength (62 MPa) was obtained for BCP containing 0.5 wt% NBG-Zn at temperature 1,200 °C. This value was approximately 80% higher than that of pure BCP. The bending strength failed when both sintering temperature and amount of added NBG-Zn increased. At 1,100 °C, NBG-Zn additive did not change the phase composition of BCP. At temperatures 1,200 and 1,300 °C, both alpha-tricalcium calcium phosphate (α-TCP) and beta-tricalcium phosphate (β-TCP and) phases were detected. However, adding higher amount of NBG-Zn to BCP resulted in elevation of β-TCP at 1,200 °C and progression of α-TCP at 1,300 °C. Based on the microscopic observations, adding 0.5 wt% NBG-Zn to BCP led to disappearance of grain boundaries, reduction of micropores and formation of a monolithic microstructure. No calcium phosphate precipitation was observed on sample surfaces after soaking in blood plasma, but some pores were produced by phase dissolution. The size and volume of these pores were directly proportional to NBG-Zn content. Based on the cell studies, both BCP and NBG-Zn-added BCP samples supported attachment and proliferation of osteoblasts, but higher alkaline phosphatase enzyme was synthesized within the cells cultured on NBG-Zn-added BCP. Overall, biphasic calcium phosphate materials with improved mechanical and biological properties

  12. ZMW型环氧乙烷灭菌箱对异体骨材料灭菌效果的初步观察%Primary observation of the sterilizing effects of ZMW anprolene case on foreign bone materials

    Institute of Scientific and Technical Information of China (English)

    孙建华; 史晨辉; 董卫; 黄新玲; 王永明; 董金波; 刘维刚

    2002-01-01

    @@ Background: The foreign bone material of the same species was widely applied, while for the multiple manipulating processes, it got lots of chances to be infected, especially for the bone manufacturing, the pollution odds increased greatly, so the sterilizing process was most important. Objective: To observe the sterilizing effects of ZMW anprolene case on foreign bone materials to find a safe and economic disinfecting way. Unit:First attached hospital of the Shihezi medical university. Subject:The manipulating method of the foreign bone material of the same species: In clean environment., bone was got in 2 hours after death of the donor, soft tissue was removed and it was made to foreign bone material of 0.5 cm× 0.5 cm× 2 cm, it was washed with water and marinated till the water got clear, then washed with distilled water repeatedly, lipid was removed with 1:1 chloroform and methanol for 4 hours at room temperature, calcium was removed with 0.6 mol/L HCL for 4 hours at 4 ℃ , it was washed with distilled water till the pH was 6.5. The bone material after treating were divided into two groups, one was dried in common air dried to make wet one plantation material and the other one was dried in 37℃ roasting case to make dry bone plantation material. They were both put in double polyethylene bags and sealed with standard sealing machine, the weight was 5 g,

  13. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

    Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

  14. PMMA-based composite materials with reactive ceramic fillers: IV. Radiopacifying particles embedded in PMMA beads for acrylic bone cements.

    Science.gov (United States)

    Abboud, M; Casaubieilh, L; Morvan, F; Fontanille, M; Duguet, E

    2000-01-01

    New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS) and embedded in poly(methylmethacrylate-co-ethylacrylate) beads with about 7 mol% of ethyl acrylate repeating units. The encapsulation was performed through a conventional suspension polymerization process. The influence of (i) the concentration of the dispersion stabilizer and (ii) the alumina content upon the shape, size, and size distribution of the acrylic beads was studied. Cements were prepared from each batch by hand-mixing alumina-filled acrylic beads with a liquid monomer mixture containing methyl methacrylate, n-butyl methacrylate, and N,N-dimethyl-p-toluidine. Benzoyl peroxide was previously added to the solid part. The powder-to-liquid ratio was equal to 2 for each formulation. Compressive strength of cured cement decreases with alumina content, whereas compressive modulus remains roughly constant. These results are in contradiction to those obtained for cements based on a mixture of gamma-MPS-treated alumina and unfilled acrylic beads. Nevertheless, they are interpreted in terms of alumina arrangement in the cement. In the first case, alumina particles contribute to the reinforcement of the dispersed acrylic phase, with poor benefits for the whole materials. In the second case, they allow the reinforcement of the continuous acrylic phase and, therefore, the cement's one.

  15. The efficacy of hydrothermally obtained carbonated hydroxyapatite in healing alveolar bone defects in rats with or without corticosteroid treatment

    Directory of Open Access Journals (Sweden)

    Marković Dejan

    2014-01-01

    Full Text Available Background/Aim. Autogenous bone grafting has been the gold standard in clinical cases when bone grafts are required for bone defects in dentistry. The study was undertaken to evaluate multilevel designed carbonated hydroxyapatite (CHA obtained by hydrothermal method, as a bone substitute in healing bone defects with or without corticosteroid treatment in rats as assessed by histopathologic methods. Methods. Bone defects were created in the alveolar bone by teeth extraction in 12 rats. The animals were initially divided into two groups. The experimental group was pretreated with corticosteroids: methylprednisolone and dexamethasone, intramuscularly, while the control group was without therapy. Posterior teeth extraction had been performed after the corticosteroid therapy. The extraction defects were fulfilled with hydroxyapatite with bimodal particle sizes in the range of 50-250 μm and the sample from postextocactional defect of the alveolar bone was analyzed pathohystologically. Results. The histopatological investigations confirmed the biologic properties of the applied material. The evident growth of new bone in the alveolar ridge was clearly noticed in both groups of rats. Carbonated HA obtained by hydrothermal method promoted bone formation in the preformed defects, confirming its efficacy for usage in bone defects. Complete resorption of the material’s particles took place after 25 weeks. Conclusion. Hydroxyapatite completely meets the clinical requirements for a bone substitute material. Due to its microstructure, complete resorption took place during the observation period of the study. Corticosteroid treatment did not significantly affect new bone formation in the region of postextractional defects. [Projekat Ministarstva nauke Republike Srbije, br. 172026

  16. Composite biopolymers for bone regeneration enhancement in bony defects.

    Science.gov (United States)

    Jahan, K; Tabrizian, M

    2016-01-01

    For the past century, various biomaterials have been used in the treatment of bone defects and fractures. Their role as potential substitutes for human bone grafts increases as donors become scarce. Metals, ceramics and polymers are all materials that confer different advantages to bone scaffold development. For instance, biocompatibility is a highly desirable property for which naturally-derived polymers are renowned. While generally applied separately, the use of biomaterials, in particular natural polymers, is likely to change, as biomaterial research moves towards mixing different types of materials in order to maximize their individual strengths. This review focuses on osteoconductive biocomposite scaffolds which are constructed around natural polymers and their performance at the in vitro/in vivo stages and in clinical trials.

  17. Analysis on Application Bottleneck of Repairing Bone Defects with Tissue Engineered Bone%组织工程骨修复骨缺损的应用瓶颈分析

    Institute of Scientific and Technical Information of China (English)

    李凯

    2012-01-01

    Bone defects caused by bone cancer treatment are common in clinical, however the only way to repair the defects is bone graft. According to sources, the bone graft material can be divided into autogenous bone, allograft bone ,xenograft bone and artificial bone substitute materials. The rise of bone tissue engineering brings new options for the treatment of bone defects. The use of artificial bone tissue engineering training not only fixes the large area of bone defect, but also can be prepared and shaped in large quantity according to need,which makes it an ideal bone repair material. Here is to make a review' on the application status of tissue engineered bone in the treatment of bone defects.%骨肿瘤的治疗导致骨缺损很常见,修复缺损的方法是采取骨移植.骨移植材料根据来源大致可分为自体骨、同种异体骨、异种骨和人工骨替代材料.骨组织工程的兴起为骨缺损的治疗带来新的选择.利用骨组织工程培养的人工骨不仅可以修复大面积骨缺损,而且可以按需塑形并大量制备,是一种理想的骨修复材料.现就组织工程骨在治疗骨缺损中的应用现状进行综述.

  18. The Use of Micro and Nano Particulate Fillers to Modify the Mechanical and Material Properties of Acrylic Bone Cement

    Science.gov (United States)

    Slane, Joshua A.

    Acrylic bone cement (polymethyl methacrylate) is widely used in total joint replacements to provide long-term fixation of implants. In essence, bone cement acts as a grout by filling in the voids left between the implant and the patient's bone, forming a mechanical interlock. While bone cement is considered the `gold standard' for implant fixation, issues such as mechanical failure of the cement mantle (aseptic loosening) and the development of prosthetic joint infection (PJI) still plague joint replacement procedures and often necessitate revision arthroplasty. In an effort to address these failures, various modifications are commonly made to bone cement such as mechanical reinforcement with particles/fibers and the addition of antibiotics to mitigate PJI. Despite these attempts, issues such as poor particle interfacial adhesion, inadequate drug release, and the development of multidrug resistant bacteria limit the effectiveness of bone cement modifications. Therefore, the overall goal of this work was to use micro and nanoparticles to enhance the properties of acrylic bone cement, with particular emphasis placed on improving the mechanical properties, cumulative antibiotic release, and antimicrobial properties. An acrylic bone cement (Palacos R) was modified with three types of particles in various loading ratios: mesoporous silica nanoparticles (for mechanical reinforcement), xylitol microparticles (for increased antibiotic release), and silver nanoparticles (as an antimicrobial agent). These particles were used as sole modifications, not in tandem with one another. The resulting cement composites were characterized using a variety of mechanical (macro to nano, fatigue, fracture, and dynamic), imaging, chemical, thermal, biological, and antimicrobial testing techniques. The primary outcomes of this dissertation demonstrate that: (1) mesoporous silica, as used in this work, is a poor reinforcement phase for acrylic bone cement, (2) xylitol can significantly

  19. Experimental study on the effects of artificial bone composite materials on bone formation%复合人工骨材料对骨形成影响的实验研究

    Institute of Scientific and Technical Information of China (English)

    李练兵; 马明福; 张其清; 侯志伟; 朱一剑; 张丹妍; 吕静; 赵乐天; 杨智曦; 朱明华

    2014-01-01

    探讨胶原/羟基磷灰石(hydroxyapatile-collagen,CHA )-骨形态发生蛋白(bone morphogenetic protein,BMP)复合材料的体外成骨效应,以及体内修复兔桡骨缺损的效果。方法采用体外细胞培养技术,将人胚成骨细胞分别与纯羟基磷灰石(hydroxyapatile,HA)、CHA、HA-BMP 和 CHA-BMP材料于体外联合培养,观察细胞的生长情况。测定细胞冻融中的细胞增殖率,及碱性磷酸酶(alkline phosphatase,ALP)、骨钙素(osteocalcin,OC)的分泌水平。小鼠股部肌袋内植入,评价其异位骨诱导能力。然后在兔桡骨缺损部位植入,术后2周、4周、8周、16周、24周观察新骨形成规律。结果胶原/羟基磷灰石-骨形态发生蛋白复合材料的细胞增殖率、ALP、OC 水平明显高于相应单一材料,异位诱导可见软骨及骨组织,ALP呈阳性。桡骨植入8周、16周时 X射线显示骨断端形成紧密的纤维连接,有少量骨痂形成,镜下可见大量成熟板层骨及骨髓组织填充,免疫组织化学(BMP、I 型胶原、骨胶原)均呈阳性反应,非 BMP复合材料未见骨或软骨形成。结论 CHA-BMP 复合材料有利于成骨细胞早期黏附、生长,小鼠异位骨诱导,加速兔缺损桡骨的新骨形成,从而促进骨愈合,是一种较理想的骨修复材料。%Objective To explore the osteogenic effect of collagen/hydroxyapatite(CHA)composite of bone morphogenetic protein (BMP)material in vitro and in repairing rabbit radius defect effect.Methods With the technique of cell culture in vitro,the human embryo osteoblast was cultured in vitro with HA,CHA,HA-BMP and CHA-BMP materials respectively and was observed the cell growth in the materials.The cell proliferation rate and secretion of ALP and OC were detected in cell frozen solution.The ability to induce ectopic bone was evaluated in the implant of mouse femoral muscle pouches.The laws of new bone formation were

  20. Bone Biopsy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Bone Biopsy Bone biopsy uses a needle and imaging ... the limitations of Bone Biopsy? What is a Bone Biopsy? A bone biopsy is an image-guided ...

  1. 基于粗糙集理论的军队代储应急物资品种选择%Emergency Material Variety Selection of Military Substitute National Reserve Based on Rough Set Theory

    Institute of Scientific and Technical Information of China (English)

    何定养; 姜大立; 汪贻生

    2015-01-01

    Based on the demand characteristics and essential attribute of military emergency material, the index system of mil⁃itary substitute reserve emergency material selection is established. Thus, through military investigation and experts experience, a group of the sample data of military substitute reserve emergency material selection is obtained and then the decision table is formed;attribute reduction is conducted to decision table using the attribute reduction algorithm based on the discernibility matrix and attribute value reduction is conducted to reduction attribute sets. Selection rules of military substitute reserve of emergency ma⁃terial are extracted, which are simple, reasonable and able to provide decision support for military substitute reserve emergency ma⁃terial selection.%从军队对应急物资的需求特点及应急物资的特征属性出发,构建了军队代储应急物资品种选择的指标体系。在此基础上,通过部队调研和专家经验获得了一组军队代储应急物资品种选择的样本数据并形成了决策表,运用基于可辨识矩阵的属性频率约简算法对决策表进行属性约简,并对约简属性集进行属性值约简,提取出军队代储应急物资品种的选择规则。提取的规则简洁合理,能够为军队代储应急物资品种选择提供决策支持。

  2. 两种骨代材料引导组织再生用于牙槽嵴保存的可行性%Feasibility of guided bone tissue regeneration technique to conserve the alveolar ridge: Two kinds of bone substitutes

    Institute of Scientific and Technical Information of China (English)

    高晓蔚; 李珂

    2012-01-01

    BACKGROUND: The ideal bone materials for guiding bone tissue regeneration can maximally recover hard and soft tissue morphology of tooth extraction fossa, which are conducive to the success of dental grown. OBJECTIVE: To compare the effects of different guided bone tissue materials on extraction socket in early reconstruction. METHODS: A total of 60 patients required the extraction of the teeth, and they were randomly divided into three groups with 20 teeth in each. The teeth were extracted and the different guided bone tissue materials were implanted. Bio-Oss and hydroxyapatite were implanted into the Bio-Oss and hydroxyapatite groups after tooth extraction, and no treatment was done in the control group. RESULTS AND CONCLUSION: The heights of the proximal alveolar bone and the interdental papilla as well as the width of lip to lingua were changed little in the Bio-Oss group, more in the hydroxyapatite group, and most in the control group. It can prove that Bio-oss is the best guided bone tissue material in conserving the alveolar ridge after tooth extraction.%背景:理想的骨引导材料可最大程度地恢复拔牙窝处软硬组织形态,利于牙体种植的成功.目的:比较不同骨代材料恢复和重建拔牙窝处软硬组织的能力.方法:纳入2010-01/2011-01 于新疆医科大学第五附属医院口腔颌面外科拔除前牙或前磨牙的60 例患者,随机分为3 组,Bio-Oss 组和羟基磷灰石组于拔牙后分别应用Bio-Oss、羟基磷灰石对拔牙窝进行填充,空白对照组拔牙后不进行任何干预.结果与结论:分别于拔牙前及拔牙后6 个月测量各组邻面牙槽嵴高度、牙间乳头高度及唇舌向宽度,经比较发现,Bio-Oss 组各项指标变化最小,羟基磷灰石组次之,空白对照组变化最大.说明Bio-Oss 作为拔牙后牙槽窝的骨代材料能够更好地维持甚至增加牙槽嵴的骨量,促进软组织外形的恢复.

  3. Multiscale approach for bone remodeling simulation based on finite element and neural network computation

    CERN Document Server

    Hambli, Ridha

    2011-01-01

    The aim of this paper is to develop a multiscale hierarchical hybrid model based on finite element analysis and neural network computation to link mesoscopic scale (trabecular network level) and macroscopic (whole bone level) to simulate bone remodelling process. Because whole bone simulation considering the 3D trabecular level is time consuming, the finite element calculation is performed at macroscopic level and a trained neural network are employed as numerical devices for substituting the finite element code needed for the mesoscale prediction. The bone mechanical properties are updated at macroscopic scale depending on the morphological organization at the mesoscopic computed by the trained neural network. The digital image-based modeling technique using m-CT and voxel finite element mesh is used to capture 2 mm3 Representative Volume Elements at mesoscale level in a femur head. The input data for the artificial neural network are a set of bone material parameters, boundary conditions and the applied str...

  4. Bone regeneration by octacalcium phosphate collagen composites in a dog alveolar cleft model.

    Science.gov (United States)

    Matsui, K; Matsui, A; Handa, T; Kawai, T; Suzuki, O; Kamakura, S; Echigo, S

    2010-12-01

    Octacalcium phosphate (OCP) and porcine atelocollagen sponge composites (OCP/Col) markedly enhanced bone regeneration in a rat cranial defect model. To assess clinical application, the authors examined whether OCP/Col would enhance bone regeneration in an alveolar cleft model in an adult dog, which was assumed to reflect patients with alveolar cleft. Disks of OCP/Col or collagen were implanted into the defect and bone regeneration by OCP/Col or collagen was investigated 4 months after implantation. Macroscopically, the OCP/Col-treated alveolus was obviously augmented and occupied by radio-opacity, and the border between the original bone and the defect was indistinguishable. Histological analysis revealed it was filled and bridged with newly formed bone; a small quantity of the remaining implanted OCP was observed. X-ray diffraction patterns of the area of implanted OCP/Col indicated no difference from those of dog bone. In the collagen-treated alveolus, the hollowed alveolus was mainly filled with fibrous connective tissue, and a small amount of new bone was observed at the defect margin. These results suggest that bone was obviously repaired when OCP/Col was implanted into the alveolar cleft model in a dog, and OCP/Col would be a significant bone regenerative material to substitute for autogeneous bone.

  5. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Bone Densitometry (DEXA) Bone densitometry, also called dual-energy ... limitations of DEXA Bone Densitometry? What is a Bone Density Scan (DEXA)? Bone density scanning, also called ...

  6. Effects of vitamin K on the morphometric and material properties of bone in the tibiae of growing rats.

    Science.gov (United States)

    Matsumoto, Takeshi; Miyakawa, Takushi; Yamamoto, Daiki

    2012-03-01

    Suboptimal vitamin K nutriture is evident during rapid growth. We aimed to determine whether vitamin K(2) (menaquinone-4 [MK-4]) supplementation is beneficial to bone structure and intrinsic bone tissue properties in growing rats. Male Wistar rats (5 weeks old) were assigned to either a control diet (n = 8) or an MK-4-supplemented diet (22 mg d(-1) kg(-1) body weight, n = 8). After a 9-week feeding period, we determined the serum concentrati