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Sample records for osteoinductive material collosse

  1. Bone tissue induction, using a COLLOSS-filled titanium fibre mesh-scaffolding material.

    PubMed

    Walboomers, X Frank; Jansen, John A

    2005-08-01

    Scaffold materials for bone tissue engineering often are supplemented with bone morphogenetic proteins (BMPs). In the current study we aimed to investigate COLLOSS, a bovine extracellular matrix product containing native BMPs. Hollow cylindrical implants were made, with a length of 10 mm, a 3 mm inner diameter, and a 5 mm outer diameter, from titanium fibre mesh. The central space of the tube was filled with 20 mg COLLOSS. Subsequently, these implants, as well as non-loaded controls, were implanted subcutaneously into the back of Wistar rats, with n=6 for all study groups. After implantation periods of 2, 8, and 12 weeks, tissue-covered implants were retrieved, and sections were made, perpendicular to the long axis of the tube. Histology showed, that all implants were surrounded by a thin fibrous tissue capsule. After 2 weeks of implantation, the COLLOSS material was reduced in size inside the loaded implants, but no bone-like tissue formation was evident. After 8 weeks, in two out of six loaded specimens, new-formed bone- and bone marrow-like tissues could be observed. After 12 weeks, this had increased to five out of six COLLOSS-loaded samples. The amount of bone-like tissue did not differ between 8 and 12 weeks, and on average occupied 15% of the central space of the tube. In the non-loaded control samples, only connective tissue ingrowth was observed. In conclusion, we can say that COLLOSS material loaded in a titanium fibre mesh tube, showed bone-inducing properties. The final efficacy of these osteo-inductive properties has to be confirmed in future large animal studies. PMID:15763257

  2. Comparing Variable-Length Polyglutamate Domains to Anchor an Osteoinductive Collagen-Mimetic Peptide to Diverse Bone Grafting Materials

    PubMed Central

    Bain, Jennifer L.; Culpepper, Bonnie K.; Reddy, Michael S.; Bellis, Susan L.

    2015-01-01

    Purpose Allografts, xenografts, and alloplasts are commonly used in craniofacial medicine as alternatives to autogenous bone grafts; however, these materials lack important bone-inducing proteins. A method for enhancing the osteoinductive potential of these commercially available materials would provide a major clinical advance. In this study, a calcium-binding domain, polyglutamate, was added to an osteoinductive peptide derived from collagen type I, Asp-Gly-Glu-Ala (DGEA), to anchor the peptide onto four different materials: freeze-dried bone allograft (FDBA); anorganic bovine bone (ABB); β-tricalcium phosphate (β-TCP); and a calcium sulfate bone cement (CaSO4). The authors also examined whether peptide binding and retention could be tuned by altering the number of glutamate residues within the polyglutamate domain. Materials and Methods DGEA or DGEA modified with diglutamate (E2DGEA), tetraglutamate (E4DGEA), or heptaglutamate (E7DGEA) were evaluated for binding and release to the grafting materials. Peptides were conjugated with a fluorescein isothiocyanate (FITC) tag to allow monitoring by fluorescent microscopy or through measurements of solution fluorescence. In vivo retention was evaluated by implanting graft materials coated with FITC-peptides into rat subcutaneous pouches. Results Significantly more peptide was loaded onto the four graft materials as the number of glutamates increased, with E7DGEA exhibiting the greatest binding. There was also significantly greater retention of peptides with longer glutamate domains following a 3-day incubation with agitation. Importantly, E7DGEA peptides remained on the grafts after a 2-month implantation into skin pouches, a sufficient interval to influence bony healing. Conclusion Variable-length polyglutamate domains can be added to osteoinductive peptides to control the amount of peptide bound and rate of peptide released. The lack of methods for tunable coupling of biologics to commercial graft sources has been a

  3. A new biphasic osteoinductive calcium composite material with a negative Zeta potential for bone augmentation

    PubMed Central

    Smeets, Ralf; Kolk, Andreas; Gerressen, Marcus; Driemel, Oliver; Maciejewski, Oliver; Hermanns-Sachweh, Benita; Riediger, Dieter; Stein, Jamal M

    2009-01-01

    The aim of the present study was to analyze the osteogenic potential of a biphasic calcium composite material (BCC) with a negative surface charge for maxillary sinus floor augmentation. In a 61 year old patient, the BCC material was used in a bilateral sinus floor augmentation procedure. Six months postoperative, a bone sample was taken from the augmented regions before two titanium implants were inserted at each side. We analyzed bone neoformation by histology, bone density by computed tomography, and measured the activity of voltage-activated calcium currents of osteoblasts and surface charge effects. Control orthopantomograms were carried out five months after implant insertion. The BCC was biocompatible and replaced by new mineralized bone after being resorbed completely. The material demonstrated a negative surface charge (negative Zeta potential) which was found to be favorable for bone regeneration and osseointegration of dental implants. PMID:19523239

  4. A composite graft material containing bone particles and collagen in osteoinduction in mouse.

    PubMed

    Tsai, Chung-Hung; Chou, Ming-Yung; Jonas, Mecrehild; Tien, Yung-Tico; Chi, Emily Y

    2002-01-01

    Demineralized allogenic bone matrices (DABM) and demineralized freeze-dried bone allograft (DFDBA) have been successfully used as bone-graft materials in the treatment of acquired and congenital cranio-maxillofacial defects and in some orthopedic surgery. However, these bone-graft "powders" have many shortcomings. For example, placement of particulate graft material in a hemorrhaging site can result in inadequacies or inaccurate attachment as well as loss of the graft materials. To minimize the inadequacies of powderlike graft materials, xenogenic collagen isolated from human tendon, skin, or bone was added to the bone-graft particles to form a composite spongelike implant. This material is commercially available and consists of 60% collagen and 40% DFDBA (DynaGraft, GenSci Co., Irvine, CA). The goal of this study was to evaluate the characteristics of composite graft implants in the mineralization process in an animal model in comparison with DFDBA powder and pure collagen. Seventy-two Swiss Webster mice were divided into three groups: an experimental group implanted with DynaGraft, two comparison groups implanted with either DFDBA or collagen only. All the graft materials were surgically implanted and inserted into the left thigh muscle. Mice were humanely killed at 1, 2, 3, 4, 6, 8, and 12 weeks. Then the muscle tissues in the vicinity of the implants were excised and processed for histology. Paraffin sections were stained with hematoxylin and eosin (H&E), the Von Kossa method, and Masson's trichrome. Some selected specimens were processed for transmission electron microscopic observation. After 1 week of implantation, the DynaGraft group showed calcium deposition on the collagen material and on the periphery of the DFDBA particles. Increased calcification and bone-forming cells were observed at 4-6 weeks. After 8 weeks, the implant formed a calcified nodule and only heavily mineralized connective tissue was observed at the implanted site. The group implanted

  5. Tissue reactions to particles of bone-substitute materials in intraosseous and heterotopic sites in rats: discrimination of osteoinduction, osteocompatibility, and inflammation.

    PubMed

    Eid, K; Zelicof, S; Perona, B P; Sledge, C B; Glowacki, J

    2001-09-01

    Two rat models were used to characterize tissue-specific reactions to particles of bone-substitute materials: one for osteocompatibility in a healing tibial wound and the other in a heterotopic, subcutaneous site. Small, unicortical tibial wounds in rats healed spontaneously, beginning with the rapid proliferation of intramedullary woven bone. That temporary bone was resorbed by osteoclasts and finally, the cortical wound was healed with lamellar bone and the medullary space was repopulated with marrow. When various particulate materials were implanted into fresh wounds, three types of reactions were observed. (1) Demineralized bone powder (DBP) and non-resorbable calcium phosphate (nrCP) were incorporated into the reactive medullary and cortical bone. (2) Polymethylmetlhacrylate (PMMA) particles were surrounded with a fibrous layer, but did not impair bone healing. (3) Polyethylene (PE) shards and resorbable calcium phosphates (rCPs) were inflammatory and inhibited osseous repair. Subcutaneous sites showed osteoinductive, fibrotic, or inflammatory responses to these materials. Only DBP induced endochondral osteogenesis subcutaneously. The nrCP evoked a fibrous reaction. In contrast, rCPs, PMMA, and PE shards generated inflammatory reactions with each particle being surrounded by fibrous tissue and large multinucleated giant cells. In conclusion, only DBP showed osteoinductive as well as osteocompatible properties. The nrCP was osteocompatible. The rCPs stimulated various degrees of inflammatory responses. PMMA was osteocompatible and did not interfere with the bone healing process. PE was not osteocompatible and generated foreign body reactions in both sites. Use of the two sites distinguishes osteoinductive, osteocompatible, and inflammatory properties of particles of bone-substitute materials. PMID:11562148

  6. A rationale for delivery of osteoinductive proteins.

    PubMed

    Brekke, J H

    1996-01-01

    Highly pure, recombinant human osteoinductive proteins make it possible to consider programmable osteoneogenesis. Until recently, it was believed that a bioresorbable excipient or physiologic solution would suffice to transport osteoinductive agents from source to wound. After considering surgical requirements, particular bone wound circumstances, scarcity of collateral circulation, phenotype plasticity of mesenchymal progenitor cells, and the morphogens' pleiotrophic effects, it becomes clear that the issue of controlled, programmable osteoneogenesis is a more complicated proposition than can be addressed solely by application of osteoinductive protein. The essential characteristics of a manufactured bone graft substitute (BGS) device are dictated by demands placed on such a device by the surgeons who will employ them and the cells that will occupy them. This review outlines a design process for BGS devices that (1) begins by surveying BGS requirements gathered from the literature from 1991 to 1995, (2) briefly reviews recent in vitro studies of rhBMP-2 and OP- 1, (3) describes commonly encountered circumstances of recipient wound beds, (4) describes behaviors of mesenchymal cells involved in connective tissue repair and regeneration, and (5) concludes with a rationale for design of an osteoinductive bone graft substitute. Emerging from this process is a composite device consisting of a bioresorbable structural polymer, a filamentous velour of hyaluronan (HY), and an osteoinductive protein. The structural polymer, D,D-L,L-polylactic acid, fabricated in the architecture of cancellous bone, is capable of maintaining its structural and architectural properties after being thoroughly saturated with water. Within its interstices is located a filamentous velour of hyaluronan which, when fully hydrated, becomes a viscoelastic gel. It is anticipated that the osteoinductive protein will either be carried on the dried hyaluronic acid velour or in solution via the

  7. Osteoconductivity and Osteoinductivity of NanoFUSE® DBM

    PubMed Central

    Kirk, James F.; Ritter, Gregg; Waters, Chad; Narisawa, Sonoko; Millán, José Luis; Talton, James D.

    2012-01-01

    Bone graft substitutes have become an essential component in a number of orthopedic applications. Autologous bone has long been the gold standard for bone void fillers. However, the limited supply and morbidity associated with using autologous graft material has led to the development of many different bone graft substitutes. Allogeneic demineralized bone matrix (DBM) has been used extensively to supplement autograft bone because of its inherent osteoconductive and osteoinductive properties. Synthetic and natural bone graft substitutes that do not contain growth factors are considered to be osteoconductive only. Bioactive glass has been shown to facilitate graft containment at the operative site as well as activate cellular osteogenesis. In the present study, we present the results of a comprehensive in vitro and in vivo characterization of a combination of allogeneic human bone and bioactive glass bone void filler, NanoFUSE® DBM. NanoFUSE® DBM is shown to be biocompatible in a number of different assays and has been approved by the FDA for use in bone filling indications. Data are presented showing the ability of the material to support cell attachment and proliferation on the material thereby demonstrating the osteoconductive nature of the material. NanoFUSE® DBM was also shown to be osteoinductive in the mouse thigh muscle model. These data demonstrate that the DBM and bioactive glass combination, NanoFUSE® DBM, could be an effective bone graft substitute. PMID:22323112

  8. Osteoinductive hydroxyapatite-coated titanium implants.

    PubMed

    Ripamonti, Ugo; Roden, Laura C; Renton, Louise F

    2012-05-01

    Previous studies have shown that heterotopic induction of bone formation by calcium phosphate-based macroporous constructs is set into motion by the geometry of the implanted substrata, i.e. a sequence of repetitive concavities assembled within the macroporous spaces. The aim of this study was to construct osteoinductive titanium implants that per se, and without the exogenous application of the osteogenic soluble molecular signals of the transforming growth factor-β supergene family, would initiate the induction of bone formation. To generate intrinsically osteoinductive titanium implants for translation in clinical contexts, titanium grade Ti-6A1-4V cylinders of 15 mm in length and 3.85 mm in diameter, with or without concavities, were plasma sprayed with crystalline hydroxyapatite resulting in a uniform layer of 30 μm in thickness. Before coating, experimental titanium implants were prepared with a sequence of 36 repetitive concavities 1600 μm in diameter and 800 μm in depth, spaced a distance of 1000 μm apart. Mandibular molars and premolars were extracted to prepare edentulous mandibular ridges for later implantation. Planar and geometric hydroxyapatite-coated titanium constructs were implanted in the left and right edentulized hemi-mandibles, respectively, after a healing period of 7-8 months, 3 per hemi-mandible. Three planar and three geometric implants were implanted in the left and right tibiae, respectively; additionally, planar and geometric constructs were also inserted in the rectus abdominis muscle. Six animals were euthanized at 30 and 90 days after implantation; one animal had to be euthanized 5 days after surgery and the remaining animal was euthanized 31 months after implantation. Undecalcified longitudinal sections were precision-sawed, ground and polished to 40-60 μm; all sections were stained with a modified Goldner's trichrome. Undecalcified specimen block preparation was performed using the EXAKT precision cutting and grinding system

  9. In vitro osteoinductive potential of porous monetite for bone tissue engineering

    PubMed Central

    Idowu, Bernadine; Cama, Giuseppe; Deb, Sanjukta

    2014-01-01

    Tissue engineering–based bone grafts are emerging as a viable alternative treatment modality to repair and regenerate tissues damaged as a result of disease or injury. The choice of the biomaterial component is a critical determinant of the success of the graft or scaffold; essentially, it must induce and allow native tissue integration, and most importantly mimic the hierarchical structure of the native bone. Calcium phosphate bioceramics are widely used in orthopaedics and dentistry applications due to their similarity to bone mineral and their ability to induce a favourable biological response. One such material is monetite, which is biocompatible, osteoconductive and has the ability to be resorbed under physiological conditions. The osteoinductive properties of monetite in vivo are known; however, little is known of the direct effect on osteoinduction of human mesenchymal stem cells in vitro. In this study, we evaluated the potential of monetite to induce and sustain human mesenchymal stem cells towards osteogenic differentiation. Human mesenchymal stem cells were seeded on the monetite scaffold in the absence of differentiating factors for up to 28 days. The gene expression profile of bone-specific markers in cells on monetite scaffold was compared to the control material hydroxyapatite. At day 14, we observed a marked increase in alkaline phosphatase, osteocalcin and osteonectin expressions. This study provides evidence of a suitable material that has potential properties to be used as a tissue engineering scaffold. PMID:24904727

  10. Fabrication and characterization of a novel carbon fiber-reinforced calcium phosphate silicate bone cement with potential osteo-inductivity.

    PubMed

    Zheng, Jiangjiang; Xiao, Yu; Gong, Tianxing; Zhou, Shuxin; Troczynski, Tom; Yang, Quanzu; Bao, Chongyun; Xu, Xiaoming

    2016-02-01

    The repair of bone defects is still a pressing challenge in clinics. Injectable bone cement is regarded as a promising material to solve this problem because of its special self-setting property. Unfortunately, its poor mechanical conformability, unfavorable osteo-genesis ability and insufficient osteo-inductivity seriously limit its clinical application. In this study, novel experimental calcium phosphate silicate bone cement reinforced by carbon fibers (CCPSC) was fabricated and characterized. First, a compressive strength test and cell culture study were carried out. Then, the material was implanted into the femoral epiphysis of beagle dogs to further assess its osteo-conductivity using a micro-computed tomography scan and histological analysis. In addition, we implanted CCPSC into the beagles' intramuscular pouches to perform an elementary investigation of its osteo-inductivity. The results showed that incorporation of carbon fibers significantly improved its mechanical properties. Meanwhile, CCPSC had better biocompatibility to activate cell adhesion as well as proliferation than poly-methyl methacrylate bone cement based on the cell culture study. Moreover, pronounced biodegradability and improved osteo-conductivity of CCPSC could be observed through the in vivo animal study. Finally, a small amount of osteoid was found at the heterotopic site one month after implantation which indicated potential osteo-inductivity of CCPSC. In conclusion, the novel CCPSC shows promise as a bioactive bone substitute in certain load-bearing circumstances. PMID:26695113

  11. Osteoinduction by combining bone morphogenetic protein (BMP)-2 with a bioactive novel nanocomposite

    PubMed Central

    Sharma, A.; Meyer, F.; Hyvonen, M.; Best, S. M.; Cameron, R. E.; Rushton, N.

    2012-01-01

    Objectives There is increasing application of bone morphogenetic proteins (BMPs) owing to their role in promoting fracture healing and bone fusion. However, an optimal delivery system has yet to be identified. The aims of this study were to synthesise bioactive BMP-2, combine it with a novel α-tricalcium phosphate/poly(D,L-lactide-co-glycolide) (α-TCP/PLGA) nanocomposite and study its release from the composite. Methods BMP-2 was synthesised using an Escherichia coli expression system and purified. In vitro bioactivity was confirmed using C2C12 cells and an alkaline phosphatase assay. The modified solution-evaporation method was used to fabricate α-TCP/PLGA nanocomposite and this was characterised using X-ray diffraction and scanning electron microscopy. Functionalisation of α-TCP/PLGA nanocomposite by adsorption of BMP-2 was performed and release of BMP-2 was characterised using an enzyme-linked immunosorbent assay (ELISA). Results Alkaline phosphatase activity of C2C12 cells was increased by the presence of all BMP-2/nanocomposite discs compared with the presence of a blank disc (p = 0.0022), and increased with increasing incubation concentrations of BMP-2, showing successful adsorption and bioactivity of BMP-2. A burst release profile was observed for BMP-2 from the nanocomposite. Conclusions Functionalisation of α-TCP/PLGA with BMP-2 produced osteoinduction and was dose-dependent. This material therefore has potential application as an osteoinductive agent in regenerative medicine. PMID:23610684

  12. Scaffold-Free Fabrication of Osteoinductive Cellular Constructs Using Mouse Gingiva-Derived Induced Pluripotent Stem Cells

    PubMed Central

    Okawa, Hiroko; Kayashima, Hiroki; Sasaki, Jun-Ichi; Miura, Jiro; Kamano, Yuya; Kosaka, Yukihiro; Imazato, Satoshi; Yatani, Hirofumi; Matsumoto, Takuya; Egusa, Hiroshi

    2016-01-01

    Three-dimensional (3D) cell constructs are expected to provide osteoinductive materials to develop cell-based therapies for bone regeneration. The proliferation and spontaneous aggregation capability of induced pluripotent stem cells (iPSCs) thus prompted us to fabricate a scaffold-free iPSC construct as a transplantation vehicle. Embryoid bodies of mouse gingival fibroblast-derived iPSCs (GF-iPSCs) were seeded in a cell chamber with a round-bottom well made of a thermoresponsive hydrogel. Collected ball-like cell constructs were cultured in osteogenic induction medium for 30 days with gentle shaking, resulting in significant upregulation of osteogenic marker genes. The constructs consisted of an inner region of unstructured cell mass and an outer osseous tissue region that was surrounded by osteoblast progenitor-like cells. The outer osseous tissue was robustly calcified with elemental calcium and phosphorous as well as hydroxyapatite. Subcutaneous transplantation of the GF-iPSC constructs into immunodeficient mice contributed to extensive ectopic bone formation surrounded by teratoma tissue. These results suggest that mouse GF-iPSCs could facilitate the fabrication of osteoinductive scaffold-free 3D cell constructs, in which the calcified regions and surrounding osteoblasts may function as scaffolds and drivers of osteoinduction, respectively. With incorporation of technologies to inhibit teratoma formation, this system could provide a promising strategy for bone regenerative therapies. PMID:27110251

  13. Effect of nano-hydroxyapatite coating on the osteoinductivity of porous biphasic calcium phosphate ceramics

    PubMed Central

    2014-01-01

    Background Porous biphasic calcium phosphate (BCP) ceramics exhibit good biocompatibility and bone conduction but are not inherently osteoinductive. To overcome this disadvantage, we coated conventional porous BCP ceramics with nano-hydroxyapatite (nHA). nHA was chosen as a coating material due to its high osteoinductive potential. Methods We used a hydrothermal deposition method to coat conventional porous BCP ceramics with nHA and assessed the effects of the coating on the physical and mechanical properties of the underlying BCP. Next, its effects on mesenchymal stem cell (MSC) attachment, proliferation, viability, and osteogenic differentiation were investigated. Results nHA formed a deposited layer on the BCP surface, and synthesized nHA had a rod-like shape with lengths ranging from ~50–200 nm and diameters from ~15–30 mm. The nHA coating did not significantly affect the density, porosity, flexural strength, or compressive strength of the underlying BCP (P > 0.1). Scanning electron microscopy showed MSC attachment to the scaffolds, with a healthy morphology and anchorage to nHA crystals via cytoplasmic processes. The densities of MSCs attached on BCP and nHA-coated BCP scaffolds were 62 ± 26 cells/mm2 and 63 ± 27 cells/mm2 (P > 0.1), respectively, after 1 day and 415 ± 62 cells/mm2 and 541 ± 35 cells/mm2 (P < 0.05) respectively, after 14 days. According to an MTT assay, MSC viability was higher on nHA-coated BCP scaffolds than on BCP scaffolds (P < 0.05). In addition, MSCs on nHA-coated BCP scaffolds produced more alkaline phosphatase, collagen type I, and osteocalcin than MSCs on BCP scaffolds (P < 0.05). Conclusions Our results demonstrate that BCP scaffolds coated with nHA were more conducive for MSC adhesion, proliferation, and osteogenic differentiation than conventional, uncoated BCP scaffolds, indicating that nHA coating can enhance the osteoinductive potential of BCP ceramics, making this material more

  14. Osteoinduction of porous Ti implants with a channel structure fabricated by selective laser melting.

    PubMed

    Fukuda, A; Takemoto, M; Saito, T; Fujibayashi, S; Neo, M; Pattanayak, Deepak K; Matsushita, T; Sasaki, K; Nishida, N; Kokubo, T; Nakamura, T

    2011-05-01

    Many studies have shown that certain biomaterials with specific porous structures can induce bone formation in non-osseous sites without the need for osteoinductive biomolecules, however, the mechanisms responsible for this phenomenon (intrinsic osteoinduction of biomaterials) remain unclear. In particular, to our knowledge the type of pore structure suitable for osteoinduction has not been reported in detail. In the present study we investigated the effects of interconnective pore size on osteoinductivity and the bone formation processes during osteoinduction. Selective laser melting was employed to fabricate porous Ti implants (diameter 3.3mm, length 15 mm) with a channel structure comprising four longitudinal square channels, representing pores, of different diagonal widths, 500, 600, 900, and 1200 μm (termed p500, p600, p900, and p1200, respectively). These were then subjected to chemical and heat treatments to induce bioactivity. Significant osteoinduction was observed in p500 and p600, with the highest observed osteoinduction occurring at 5mm from the end of the implants. A distance of 5mm probably provides a favorable balance between blood circulation and fluid movement. Thus, the simple architecture of the implants allowed effective investigation of the influence of the interconnective pore size on osteoinduction, as well as the relationship between bone quantity and its location for different pore sizes. PMID:21295166

  15. Osteoinductive PolyHIPE Foams as Injectable Bone Grafts.

    PubMed

    Robinson, Jennifer L; McEnery, Madison A P; Pearce, Hannah; Whitely, Michael E; Munoz-Pinto, Dany J; Hahn, Mariah S; Li, Huinan; Sears, Nicholas A; Cosgriff-Hernandez, Elizabeth

    2016-03-01

    We have recently fabricated biodegradable polyHIPEs as injectable bone grafts and characterized the mechanical properties, pore architecture, and cure rates. In this study, calcium phosphate nanoparticles and demineralized bone matrix (DBM) particles were incorporated into injectable polyHIPE foams to promote osteoblastic differentiation of mesenchymal stem cells (MSCs). Upon incorporation of each type of particle, stable monoliths were formed with compressive properties comparable to control polyHIPEs. Pore size quantification indicated a negligible effect of all particles on emulsion stability and resulting pore architecture. Alizarin red calcium staining illustrated the incorporation of calcium phosphate particles at the pore surface, while picrosirius red collagen staining illustrated collagen-rich DBM particles within the monoliths. Osteoinductive particles had a negligible effect on the compressive modulus (∼30 MPa), which remained comparable to human cancellous bone values. All polyHIPE compositions promoted human MSC viability (∼90%) through 2 weeks. Furthermore, gene expression analysis indicated the ability of all polyHIPE compositions to promote osteogenic differentiation through the upregulation of bone-specific markers compared to a time zero control. These findings illustrate the potential for these osteoinductive polyHIPEs to promote osteogenesis and validate future in vivo evaluation. Overall, this work demonstrates the ability to incorporate a range of bioactive components into propylene fumarate dimethacrylate-based injectable polyHIPEs to increase cellular interactions and direct specific behavior without compromising scaffold architecture and resulting properties for various tissue engineering applications. PMID:26739120

  16. Influence of surface microstructure and chemistry on osteoinduction and osteoclastogenesis by biphasic calcium phosphate discs.

    PubMed

    Davison, N L; Su, J; Yuan, H; van den Beucken, J J J P; de Bruijn, J D; Barrère-de Groot, F

    2015-01-01

    It has been reported that surface microstructural dimensions can influence the osteoinductivity of calcium phosphates (CaPs), and osteoclasts may play a role in this process. We hypothesised that surface structural dimensions of ≤ 1 μm trigger osteoinduction and osteoclast formation irrespective of macrostructure (e.g., concavities, interconnected macropores, interparticle space) or surface chemistry. To test this, planar discs made of biphasic calcium phosphate (BCP: 80% hydroxyapatite, 20% tricalcium phosphate) were prepared with different surface structural dimensions - either ~ 1 μm (BCP1150) or ~ 2-4 μm (BCP1300) - and no macropores or concavities. A third material was made by sputter coating BCP1150 with titanium (BCP1150Ti), thereby changing its surface chemistry but preserving its surface structure and chemical reactivity. After intramuscular implantation in 5 dogs for 12 weeks, BCP1150 formed ectopic bone in 4 out of 5 samples, BCP1150Ti formed ectopic bone in 3 out of 5 samples, and BCP1300 formed no ectopic bone in any of the 5 samples. In vivo, large multinucleated osteoclast-like cells densely colonised BCP1150, smaller osteoclast-like cells formed on BCP1150Ti, and osteoclast-like cells scarcely formed on BCP1300. In vitro, RAW264.7 cells cultured on the surface of BCP1150 and BCP1150Ti in the presence of osteoclast differentiation factor RANKL (receptor activator for NF-κB ligand) proliferated then differentiated into multinucleated osteoclast-like cells with positive tartrate resistant acid phosphatase (TRAP) activity. However, cell proliferation, fusion, and TRAP activity were all significantly inhibited on BCP1300. These results indicate that of the material parameters tested - namely, surface microstructure, macrostructure, and surface chemistry - microstructural dimensions are critical in promoting osteoclastogenesis and triggering ectopic bone formation. PMID:26091730

  17. Encapsulated boron as an osteoinductive agent for bone scaffolds.

    PubMed

    Gümüşderelioğlu, Menemşe; Tunçay, Ekin Ö; Kaynak, Gökçe; Demirtaş, Tolga T; Aydın, Seda Tığlı; Hakkı, Sema S

    2015-01-01

    The aim of this study was to develop boron (B)-releasing polymeric scaffold to promote regeneration of bone tissue. Boric acid-doped chitosan nanoparticles with a diameter of approx. 175 nm were produced by tripolyphosphate (TPP)-initiated ionic gelation process. The nanoparticles strongly attached via electrostatic interactions into chitosan scaffolds produced by freeze-drying with approx. 100 μm pore diameter. According to the ICP-OES results, following first 5h initial burst release, fast release of B from scaffolds was observed for 24h incubation period in conditioned medium. Then, slow release of B was performed over 120 h. The results of the cell culture studies proved that the encapsulated boron within the scaffolds can be used as an osteoinductive agent by showing its positive effects on the proliferation and differentiation of MC3T3-E1 preosteoblastic cells. PMID:26004902

  18. Novel osteoinductive biomimetic scaffolds stimulate human osteoprogenitor activity--implications for skeletal repair.

    PubMed

    Yang, X B; Green, D W; Roach, H I; Clarke, N M P; Anderson, H C; Howdle, S M; Shakesheff, K M; Oreffo, R O C

    2003-01-01

    The development of new bone formation strategies offers tremendous therapeutic implications in a variety of musculoskeletal diseases. One approach involves harnessing the regenerative capacity of osteoprogenitor bone cells in combination with biomimetic scaffolds generated from appropriate scaffold matrices and osteoinductive factors. The aims of our study were to test the efficacy of two innovative osteoinductive agents: the osteoblast stimulating factor-1 (osf-1), an extracellular matrix-associated protein, and osteoinductive extracts of Saos-2 cells on human osteoprogenitor cells. Saos-2 extracted osteoinductive factors significantly stimulated alkaline phosphatase specific activity in basal and osteogenic conditions. Osf-1 significantly stimulated chemotaxis, total colony formation, alkaline phosphatase-positive colony formation, and alkaline phosphatase specific activity at concentrations as low as 10 pg/ml compared with control cultures. Osteoinductive factors present in Saos-2 cell extracts and osf-1 promoted adhesion, migration, expansion, and differentiation of human osteoprogenitor cells on 3-D scaffolds. The successful generation of 3-D biomimetic structures incorporating osf-1 or osteoinductive factors from Saos-2 cells indicates their potential for de novo bone formation that exploits cell-matrix interactions. PMID:12952215

  19. A Simple Approach for an Eggshell-Based 3D-Printed Osteoinductive Multiphasic Calcium Phosphate Scaffold.

    PubMed

    Dadhich, Prabhash; Das, Bodhisatwa; Pal, Pallabi; Srivas, Pavan K; Dutta, Joy; Ray, Sabyasachi; Dhara, Santanu

    2016-05-18

    Natural origin bioceramics are widely used for bone grafts. In the present study, an eggshell-derived bioceramic scaffold is fabricated by 3D printing as a potential bone-graft analogue. The eggshell, a biological waste material, was mixed with a specific ratio of phosphoric acid and chitosan to form a precursor toward the fabrication of an osteoinductive multiphasic calcium phosphate scaffold via a coagulation-assisted extrusion and sintering for a multiscalar hierarchical porous structure with improved mechanical properties. Physicochemical characterization of the formed scaffolds was carried out for phase analysis, surface morphology, and mechanical properties. A similar scaffold was prepared using a chemically synthesized calcium phosphate powder that was compared with the natural origin one. The higher surface area associated with the interconnected porosity along with multiple phases of the natural origin scaffold facilitated higher cell adhesion and proliferation compared to the chemically synthesized one. Further, the natural origin scaffold displayed relatively higher cell differentiation activity, as is evident by protein and gene expression studies. On subcutaneous implantation for 30 days, promising vascular tissue in-growth was observed, circumventing a major foreign body response. Collagen-rich vascular extracellular matrix deposition and osteocalcin secretion indicated bonelike tissue formation. Finally, the eggshell-derived multiphasic calcium phosphate scaffold displayed improvement in the mechanical properties with higher porosity and osteoinductivity compared to the chemically derived apatite and unveiled a new paradigm for utilization of biological wastes in bone-graft application. PMID:26853051

  20. Osteoinductivity of engineered cartilaginous templates devitalized by inducible apoptosis.

    PubMed

    Bourgine, Paul E; Scotti, Celeste; Pigeot, Sebastien; Tchang, Laurent A; Todorov, Atanas; Martin, Ivan

    2014-12-01

    The role of cell-free extracellular matrix (ECM) in triggering tissue and organ regeneration has gained increased recognition, yet current approaches are predominantly based on the use of ECM from fully developed native tissues at nonhomologous sites. We describe a strategy to generate customized ECM, designed to activate endogenous regenerative programs by recapitulating tissue-specific developmental processes. The paradigm was exemplified in the context of the skeletal system by testing the osteoinductive capacity of engineered and devitalized hypertrophic cartilage, which is the primordial template for the development of most bones. ECM was engineered by inducing chondrogenesis of human mesenchymal stromal cells and devitalized by the implementation of a death-inducible genetic device, leading to cell apoptosis on activation and matrix protein preservation. The resulting hypertrophic cartilage ECM, tested in a stringent ectopic implantation model, efficiently remodeled to form de novo bone tissue of host origin, including mature vasculature and a hematopoietic compartment. Importantly, cartilage ECM could not generate frank bone tissue if devitalized by standard "freeze & thaw" (F&T) cycles, associated with a significant loss of glycosaminoglycans, mineral content, and ECM-bound cytokines critically involved in inflammatory, vascularization, and remodeling processes. These results support the utility of engineered ECM-based devices as off-the-shelf regenerative niches capable of recruiting and instructing resident cells toward the formation of a specific tissue. PMID:25422415

  1. Osteoinductivity of engineered cartilaginous templates devitalized by inducible apoptosis

    PubMed Central

    Bourgine, Paul E.; Scotti, Celeste; Pigeot, Sebastien; Tchang, Laurent A.; Todorov, Atanas; Martin, Ivan

    2014-01-01

    The role of cell-free extracellular matrix (ECM) in triggering tissue and organ regeneration has gained increased recognition, yet current approaches are predominantly based on the use of ECM from fully developed native tissues at nonhomologous sites. We describe a strategy to generate customized ECM, designed to activate endogenous regenerative programs by recapitulating tissue-specific developmental processes. The paradigm was exemplified in the context of the skeletal system by testing the osteoinductive capacity of engineered and devitalized hypertrophic cartilage, which is the primordial template for the development of most bones. ECM was engineered by inducing chondrogenesis of human mesenchymal stromal cells and devitalized by the implementation of a death-inducible genetic device, leading to cell apoptosis on activation and matrix protein preservation. The resulting hypertrophic cartilage ECM, tested in a stringent ectopic implantation model, efficiently remodeled to form de novo bone tissue of host origin, including mature vasculature and a hematopoietic compartment. Importantly, cartilage ECM could not generate frank bone tissue if devitalized by standard “freeze & thaw” (F&T) cycles, associated with a significant loss of glycosaminoglycans, mineral content, and ECM-bound cytokines critically involved in inflammatory, vascularization, and remodeling processes. These results support the utility of engineered ECM-based devices as off-the-shelf regenerative niches capable of recruiting and instructing resident cells toward the formation of a specific tissue. PMID:25422415

  2. Biological Strategies for Improved Osseointegration and Osteoinduction of Porous Metal Orthopedic Implants

    PubMed Central

    Riester, Scott M.; Bonin, Carolina A.; Kremers, Hilal Maradit; Dudakovic, Amel; Kakar, Sanjeev; Cohen, Robert C.; Westendorf, Jennifer J.

    2015-01-01

    The biological interface between an orthopedic implant and the surrounding host tissue may have a dramatic effect upon clinical outcome. Desired effects include bony ingrowth (osseointegration), stimulation of osteogenesis (osteoinduction), increased vascularization, and improved mechanical stability. Implant loosening, fibrous encapsulation, corrosion, infection, and inflammation, as well as physical mismatch may have deleterious clinical effects. This is particularly true of implants used in the reconstruction of load-bearing synovial joints such as the knee, hip, and the shoulder. The surfaces of orthopedic implants have evolved from solid-smooth to roughened-coarse and most recently, to porous in an effort to create a three-dimensional architecture for bone apposition and osseointegration. Total joint surgeries are increasingly performed in younger individuals with a longer life expectancy, and therefore, the postimplantation lifespan of devices must increase commensurately. This review discusses advancements in biomaterials science and cell-based therapies that may further improve orthopedic success rates. We focus on material and biological properties of orthopedic implants fabricated from porous metal and highlight some relevant developments in stem-cell research. We posit that the ideal primary and revision orthopedic load-bearing metal implants are highly porous and may be chemically modified to induce stem cell growth and osteogenic differentiation, while minimizing inflammation and infection. We conclude that integration of new biological, chemical, and mechanical methods is likely to yield more effective strategies to control and modify the implant–bone interface and thereby improve long-term clinical outcomes. PMID:25348836

  3. Bone sialoprotein-coated femoral implants are osteoinductive but mechanically compromised.

    PubMed

    O'Toole, Gary C; Salih, E; Gallagher, C; FitzPatrick, D; O'Higgins, N; O'Rourke, S K

    2004-05-01

    Aseptic loosening of femoral implants in total hip replacement remains an unsolved orthopaedic problem. This paper investigates the potential role of bone sialoprotein (BSP) in enhancing bone-implant adherence. As BSP is osteoinductive in rat calvarial models, we investigated whether BSP is similarly osteoinductive when coated onto intramedullary femoral implants. BSP-coated titanium implants were implanted into the femur of female 'Wistar' rats (average weight 215 g) that were sacrificed at days 10, 20 and 30. Harvested femoral implants were subjected to pullout testing and then examined histologically. BSP-coated implants demonstrate osteoinduction when examined histologically. Plugging the femoral canal with BSP prior to inserting the implant neither increased implant pullout strengths nor further increased osteoblastic activity. This study has demonstrated for the first time that BSP is osteoinductive when coated onto femoral implants and inserted into bones subjected to mechanical loading. However, we found that pullout strengths are a function of implant surface topographical characteristics and are not affected by BSP coating or histological osteoinduction. PMID:15099646

  4. Experimental osteoinduction in rats: collagen-apatite versus osteogenin-containing gelatine.

    PubMed

    Schwarz, N; Redl, H; Schlag, G; Lintner, F; Dinges, H P; Thurnher, M; Schiesser, A

    1987-01-01

    An experimental study in rats was done to investigate the bone-regenerating properties of collagen apatite (Collapat) and to compare it with osteoinduction dependent on osteogenin-containing gelatine (OCG). The test substances were implanted orthotopically (calvarial defect--7 mm in diameter) and heterotopically (paravertebral muscles, abdominal muscles). The results were evaluated histologically and enzymatically (alkaline phosphatase). Collapat caused neither osteoinduction in the heterotopic site nor healing of the bone defects. Foreign body reaction without new bone formation was encountered. OCG implantation leads to new bone formation in the muscles within 3 weeks, associated with a significant increase in alkaline phosphatase activity, and to extensive new bone formation in the calvarial defect within 4 weeks. The defects did not heal if left empty. The value of clinical application of Collapat appears to be doubtful. Osteoinduction with OCG requires further experimental investigation. PMID:3551878

  5. Design of an Osteoinductive Extracellular Fibronectin Matrix Protein for Bone Tissue Engineering

    PubMed Central

    Lee, Sujin; Lee, Dong-Sung; Choi, Ilsan; Pham, Le B. Hang; Jang, Jun-Hyeog

    2015-01-01

    Integrin-mediated cell-matrix interactions play an important role in osteogenesis. Here, we constructed a novel osteoinductive fibronectin matrix protein (oFN) for bone tissue engineering, designed to combine the integrin-binding modules from fibronectin (iFN) and a strong osteoinductive growth factor, bone morphogenetic protein-2. Compared with iFN, the purified oFN matrix protein caused a significant increase in cell adhesion and osteogenic differentiation of pre-osteoblast MC3T3-E1 cells (p < 0.05). PMID:25853265

  6. Icariin: does it have an osteoinductive potential for bone tissue engineering?

    PubMed

    Zhang, Xin; Liu, Tie; Huang, Yuanliang; Wismeijer, Daniel; Liu, Yuelian

    2014-04-01

    Traditional Chinese medicines have been recommended for bone regeneration and repair for thousands of years. Currently, the Herba Epimedii and its multi-component formulation are the attractive native herbs for the treatment of osteoporosis. Icariin, a typical flavonol glycoside, is considered to be the main active ingredient of the Herba Epimedii from which icariin has been successfully extracted. Most interestingly, it has been reported that icariin can be delivered locally by biomaterials and that it has an osteoinductive potential for bone tissue engineering. This review focuses on the performance of icariin in bone tissue engineering and on blending the information from icariin with the current knowledge relevant to molecular mechanisms and signal pathways. The osteoinductive potential of icariin could be attributed to its multiple functions in the musculoskeletal system which is involved in the regulation of multiple signaling pathways in anti-osteoporosis, osteogenesis, anti-osteoclastogenesis, chondrogenesis, angiogenesis, and anti-inflammation. The osteoinductive potential and the low price of icariin make it a very attractive candidate as a substitute of osteoinductive protein-bone morphogenetic proteins (BMPs), or as a promoter for enhancing the therapeutic effects of BMPs. However, the effectiveness of the local delivery of icariin needs to be investigated further. PMID:23824956

  7. Biomaterials with Antibacterial and Osteoinductive Properties to Repair Infected Bone Defects

    PubMed Central

    Lu, Haiping; Liu, Yi; Guo, Jing; Wu, Huiling; Wang, Jingxiao; Wu, Gang

    2016-01-01

    The repair of infected bone defects is still challenging in the fields of orthopedics, oral implantology and maxillofacial surgery. In these cases, the self-healing capacity of bone tissue can be significantly compromised by the large size of bone defects and the potential/active bacterial activity. Infected bone defects are conventionally treated by a systemic/local administration of antibiotics to control infection and a subsequent implantation of bone grafts, such as autografts and allografts. However, these treatment options are time-consuming and usually yield less optimal efficacy. To approach these problems, novel biomaterials with both antibacterial and osteoinductive properties have been developed. The antibacterial property can be conferred by antibiotics and other novel antibacterial biomaterials, such as silver nanoparticles. Bone morphogenetic proteins are used to functionalize the biomaterials with a potent osteoinductive property. By manipulating the carrying modes and release kinetics, these biomaterials are optimized to maximize their antibacterial and osteoinductive functions with minimized cytotoxicity. The findings, in the past decade, have shown a very promising application potential of the novel biomaterials with the dual functions in treating infected bone defects. In this review, we will summarize the current knowledge of novel biomaterials with both antibacterial and osteoinductive properties. PMID:26950123

  8. Osteoinductive peptide-functionalized nanofibers with highly ordered structure as biomimetic scaffolds for bone tissue engineering

    PubMed Central

    Gao, Xiang; Zhang, Xiaohong; Song, Jinlin; Xu, Xiao; Xu, Anxiu; Wang, Mengke; Xie, Bingwu; Huang, Enyi; Deng, Feng; Wei, Shicheng

    2015-01-01

    The construction of functional biomimetic scaffolds that recapitulate the topographical and biochemical features of bone tissue extracellular matrix is now of topical interest in bone tissue engineering. In this study, a novel surface-functionalized electrospun polycaprolactone (PCL) nanofiber scaffold with highly ordered structure was developed to simulate the critical features of native bone tissue via a single step of catechol chemistry. Specially, under slightly alkaline aqueous solution, polydopamine (pDA) was coated on the surface of aligned PCL nanofibers after electrospinning, followed by covalent immobilization of bone morphogenetic protein-7-derived peptides onto the pDA-coated nanofiber surface. Contact angle measurement, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed the presence of pDA and peptides on PCL nanofiber surface. Our results demonstrated that surface modification with osteoinductive peptides could improve cytocompatibility of nanofibers in terms of cell adhesion, spreading, and proliferation. Most importantly, Alizarin Red S staining, quantitative real-time polymerase chain reaction, immunostaining, and Western blot revealed that human mesenchymal stem cells cultured on aligned nanofibers with osteoinductive peptides exhibited enhanced osteogenic differentiation potential than cells on randomly oriented nanofibers. Furthermore, the aligned nanofibers with osteoinductive peptides could direct osteogenic differentiation of human mesenchymal stem cells even in the absence of osteoinducting factors, suggesting superior osteogenic efficacy of biomimetic design that combines the advantages of osteoinductive peptide signal and highly ordered nanofibers on cell fate decision. The presented peptide-decorated bone-mimic nanofiber scaffolds hold a promising potential in the context of bone tissue engineering. PMID:26604759

  9. Polyglutamate directed coupling of bioactive peptides for the delivery of osteoinductive signals on allograft bone

    PubMed Central

    Culpepper, Bonnie K.; Bonvallet, Paul P.; Reddy, Michael S.; Ponnazhagan, Selvarangan; Bellis, Susan L.

    2012-01-01

    Allograft bone is commonly used as an alternative to autograft, however allograft lacks many osteoinductive factors present in autologous bone due to processing. In this study, we investigated a method to reconstitute allograft with osteoregenerative factors. Specifically, an osteoinductive peptide from collagen I, DGEA, was engineered to express a heptaglutamate (E7) domain, which binds the hydroxyapatite within bone mineral. Addition of E7 to DGEA resulted in 9× greater peptide loading on allograft, and significantly greater retention after a 5-day interval with extensive washing. When factoring together greater initial loading and retention, the E7 domain directed a 45-fold enhancement of peptide density on the allograft surface. Peptide-coated allograft was also implanted subcutaneously into rats and it was found that E7DGEA was retained in vivo for at least 3 months. Interestingly, E7DGEA peptides injected intravenously accumulated within bone tissue, implicating a potential role for E7 domains in drug delivery to bone. Finally, we determined that, as with DGEA, the E7 modification enhanced coupling of a bioactive BMP2-derived peptide on allograft. These results suggest that E7 domains are useful for coupling many types of bone-regenerative molecules to the surface of allograft to reintroduce osteoinductive signals and potentially advance allograft treatments. PMID:23182349

  10. Osteoinductive Effects of Free and Immobilized Bone Forming Peptide-1 on Human Adipose-Derived Stem Cells.

    PubMed

    Li, Wenyue; Zheng, Yunfei; Zhao, Xianghui; Ge, Yanjun; Chen, Tong; Liu, Yunsong; Zhou, Yongsheng

    2016-01-01

    Most synthetic polymeric materials currently used for bone tissue engineering lack specific signals through which cells can identify and interact with the surface, resulting in incompatibility and compromised osteogenic activity. Soluble inductive factors also have issues including a short half-live in vivo. Bone forming peptide-1 is a truncated peptide from the immature form of bone morphogenetic protein-7 (BMP-7) that displays higher osteogenic activity than full-length, mature BMP-7. In this study, we used a mussel-inspired immobilization strategy mediated by polymerization of dopamine to introduce recently discovered stimulators of bone forming peptide-1 (BFP-1) onto the surface of poly-lactic-co-glycolic acid (PLGA) substrate to form a biomaterial that overcomes these challenges. Human adipose-derived stem cells (hASCs), being abundant and easy accessible, were used to test the osteogenic activity of BFP-1 and the novel biomaterial. Under osteoinductive conditions, cells treated with both BFP-1 alone and BFP-1-coated biomaterials displayed elevated expression of the osteogenic markers alkaline phosphatase (ALP), osteocalcin (OC), and RUNX2. Furthermore, hASCs associated with poly-dopamine-assisted BFP-1-immobilized PLGA (pDA-BFP-1-PLGA) scaffolds promoted in vivo bone formation in nude mice. Our novel materials may hold great promise for future bone tissue engineering applications. PMID:26930062

  11. Osteoinductive Effects of Free and Immobilized Bone Forming Peptide-1 on Human Adipose-Derived Stem Cells

    PubMed Central

    Zhao, Xianghui; Ge, Yanjun; Chen, Tong; Liu, Yunsong; Zhou, Yongsheng

    2016-01-01

    Most synthetic polymeric materials currently used for bone tissue engineering lack specific signals through which cells can identify and interact with the surface, resulting in incompatibility and compromised osteogenic activity. Soluble inductive factors also have issues including a short half-live in vivo. Bone forming peptide-1 is a truncated peptide from the immature form of bone morphogenetic protein-7 (BMP-7) that displays higher osteogenic activity than full-length, mature BMP-7. In this study, we used a mussel-inspired immobilization strategy mediated by polymerization of dopamine to introduce recently discovered stimulators of bone forming peptide-1 (BFP-1) onto the surface of poly-lactic-co-glycolic acid (PLGA) substrate to form a biomaterial that overcomes these challenges. Human adipose-derived stem cells (hASCs), being abundant and easy accessible, were used to test the osteogenic activity of BFP-1 and the novel biomaterial. Under osteoinductive conditions, cells treated with both BFP-1 alone and BFP-1-coated biomaterials displayed elevated expression of the osteogenic markers alkaline phosphatase (ALP), osteocalcin (OC), and RUNX2. Furthermore, hASCs associated with poly-dopamine-assisted BFP-1-immobilized PLGA (pDA-BFP-1-PLGA) scaffolds promoted in vivo bone formation in nude mice. Our novel materials may hold great promise for future bone tissue engineering applications. PMID:26930062

  12. Synthetic Calcite as a Scaffold for Osteoinductive Bone Substitutes.

    PubMed

    Chróścicka, Anna; Jaegermann, Zbigniew; Wychowański, Piotr; Ratajska, Anna; Sadło, Jarosław; Hoser, Grażyna; Michałowski, Sławomir; Lewandowska-Szumiel, Malgorzata

    2016-07-01

    Although a wide variety of biomaterials have been already proposed for use in bone tissue engineering, there is still need for man-made materials, which would combine support for osteogenesis with simplicity desirable for upscaling and costs reduction. In this study we have shown that synthetic calcite may serve as a scaffold for human osteoblasts transplantation. A simple dynamic system allows uniform and effective cell distribution. Cell viability and osteogenic phenotype were confirmed by XTT assay, alkaline phosphatase activity and selected osteoblast-specific genes expression. Extracellular matrix deposited by cells improved elasticity and made the whole system similar to the flexible composite material rather than to the brittle ceramic implants. It was revealed in the compression tests and also by the improved samples handling. Subcutaneous implantation of the cell-seeded calcite scaffolds to immunodeficient mice resulted in mineralized bone formation, which was confirmed histologically and by EPR analysis. The latter we propose as a method supplementary to histological analysis, for bone regeneration investigations. It specifically confirms the presence of bone mineral with a unique sensitivity and using bulk samples, which eliminates the risk of missing the material in the preparation. Our study resulted in development of a new osteogenic tissue engineered product based on man-made calcite. PMID:26666226

  13. Fabrication of silver nanoparticle-doped hydroxyapatite coatings with oriented block arrays for enhancing bactericidal effect and osteoinductivity.

    PubMed

    Tian, Bo; Chen, Wei; Yu, Degang; Lei, Yong; Ke, Qinfei; Guo, Yaping; Zhu, Zhenan

    2016-08-01

    Implant-associated infection is a common postoperative complication and remains a serious problem in orthopedic surgery. This work describes the synthesis of silver nanoparticle-doped hydroxyapatite coatings with oriented block arrays (AgNP-BHAC). The resulting nanostructure was investigated using scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy. AgNP-BHAC exhibited excellent antimicrobial activity toward gram-negative Escherichia coli and gram-positive Staphylococcus aureus owing to the antibacterial effects of the silver nanoparticles. Human bone marrow stromal cells (hBMSC) culture revealed that the AgNP-BHAC exhibited better biocompatibility, and permitted improved cell proliferation, attachment, and osteoinductivity than uncoated Ti-6Al-4V titanium alloy, the favored material for biomedical applications. In summary, this study presents a convenient and effective method for the incorporation of silver into HA coatings with block morphology. This method can be utilized to modify a variety of metallic implant surfaces to improve their antimicrobial effects and reduce potential long-term cytotoxicity. PMID:27107263

  14. Myo-conductive and osteo-inductive free-standing polysaccharide membranes

    PubMed Central

    Caridade, Sofia G.; Monge, Claire; Almodóvar, Jorge; Guillot, Raphael; Lavaud, Jonathan; Josserand, Véronique; Coll, Jean-Luc; Mano, João F.; Picart, Catherine

    2015-01-01

    Free-standing (FS) membranes have increasing applications in the biomedical field as drug delivery systems for wound healing and tissue engineering. Here, we studied the potential of free-standing membranes made by the layer-by-layer assembly of chitosan and alginate to be used as a simple biomimetic system of the periosteum. The design of a periosteum-like membrane implies the elaboration of a thick membrane suitable for both muscle and bone formation. Our aim was to produce well defined ~50 μm thick polysaccharide membranes that could be easily manipulated, be mechanically resistant, and enable both myogenesis and osteogenesis in vitro and in vivo. The membranes were chemically crosslinked to improve their mechanical properties. Crosslinking chemistry was followed via FTIR and the mechanical properties of the membranes were assessed using dynamic mechanical analysis. The loading and release of the potent osteoinductive growth factor bone morphogenetic protein 2 (BMP-2) inside and outside of the FS membrane was followed by fluorescence spectroscopy in a physiological buffer over one month. The myogenic and osteogenic potential of the membranes in vitro was assessed using BMP-2 responsive skeletal myoblasts. Finally, their osteoinductive properties in vivo were studied in a preliminary experiment using a mouse ectopic model. Our results showed that the more crosslinked FS membranes enabled a more efficient myoblast differentiation in myotubes. In addition, we showed that a tunable amount of BMP-2 can be loaded in and subsequently released from the membranes depending on the crosslinking degree and BMP-2 initial concentration in solution. Only the more crosslinked membranes were found to be osteoinductive in vivo. These polysaccharide-based membranes have strong potential as a periosteum-mimetic scaffold for bone tissue regeneration. PMID:25575853

  15. Comparative evaluation of the osteoinductivity of two formulations of human demineralized bone matrix.

    PubMed

    Takikawa, Satoshi; Bauer, Thomas W; Kambic, Helen; Togawa, Daisuke

    2003-04-01

    In the United States, demineralized bone matrix (DBM) is considered a transplantable tissue and therefore is regulated primarily by the American Association of Tissue Banks. Even though DBM is not subjected to the same regulations relative to performance claims as medical devices are, one would expect different processing methods might yield DBM preparations of different osteoinductive potential. The purpose of this study was to use an established athymic rat model to compare the osteoinductive properties of two commercially available human DBMs prepared using different methods but having essentially identical product claims. Sixteen female athymic rats were used to test equivalent volumes of two lots each of Grafton Putty (Osteotech, Inc., Eatontown, NJ), Osteofil (Regeneration Technologies, Inc., Alachua, FL), and rat DBM. At 28 days after implantation, qualitative and semiquantitative microscopy showed no significant differences in bone formation between the two lots from each source, but rat DBM produced significantly more bone than Grafton, which produced significantly more bone than Osteofil. Our results suggest that methods of graft processing may represent a greater source of variability than do differences among individual donors. Whether these differences relate to methods of demineralization, carrier, dose of DBM per volume, or to some other factor remains to be determined. PMID:12635152

  16. Production of an osteoinductive demineralised bone matrix powder without the use of organic solvents.

    PubMed

    Eagle, M J; Rooney, P; Kearney, J N

    2015-09-01

    Demineralised bone matrix (DBM) is produced by grinding cortical bone into a powder, sieving the powder to obtain a desired size range and then demineralising the powder using acid. Protocols for the production of DBM powder have been published since 1965 and the powder can be used in lyophilised form or it can be mixed with a carrier to produce a paste or putty. The powder is generally produced from cortical bone which has been processed to remove blood, bone marrow and bone marrow components, including fat. Removal of fat is accomplished by incorporating incubation in an organic solvent, often chloroform, chloroform/methanol or acetone. The use of organic solvents in a clean room environment in a human tissue bank is problematic and involves operator exposure and the potential for the solvent to be trapped in air filters or recirculated throughout the clean room suite. Consequently, in this study, we have developed a cortical bone washing step which removes fat/lipid without the use of an organic solvent. Bone was prepared from six femoral shafts from three donors by dissecting soft tissue and bisecting the shaft, the shafts were then cut into ~9-10 cm lengths. These struts were then taken through a series of hot water washes at 56-59 °C, centrifugation and decontamination steps. Washed cortical struts were then lyophilised before being ground with a compressed air milling machine. The ground bone was sieved, demineralised, freeze-dried and terminally sterilised with a target dose of 25 kGy gamma irradiation. The DBM powder was evaluated for residual calcium content, in vitro cytotoxicity and osteoinductivity by implantation into the muscle of an athymic mouse. Data indicated that in addition to removing in excess of 97% DNA and extractable soluble protein, the washing protocol reduced lipid 10,000-fold. The processed bone was easily ground without clogging the grinder; the sterilised DBM powder was not cytotoxic but was osteoinductive in the animal model

  17. In vitro osteoinduction of human mesenchymal stem cells in biomimetic surface modified titanium alloy implants.

    PubMed

    Santander, Sonia; Alcaine, Clara; Lyahyai, Jaber; Pérez, Maria Angeles; Rodellar, Clementina; Doblaré, Manuel; Ochoa, Ignacio

    2012-01-01

    Interaction between cells and implant surface is crucial for clinical success. This interaction and the associated surface treatment are essential for achieving a fast osseointegration process. Several studies of different topographical or chemical surface modifications have been proposed previously in literature. The Biomimetic Advanced Surface (BAS) topography is a combination of a shot blasting and anodizing procedure. Macroroughness, microporosity of titanium oxide and Calcium/Phosphate ion deposition is obtained. Human mesenchymal stem cells (hMCSs) response in vitro to this treatment has been evaluated. The results obtained show an improved adhesion capacity and a higher proliferation rate when hMSCs are cultured on treated surfaces. This biomimetic modification of the titanium surface induces the expression of osteblastic differentiation markers (RUNX2 and Osteopontin) in the absence of any externally provided differentiation factor. As a main conclusion, our biomimetic surface modification could lead to a substantial improvement in osteoinduction in titanium alloy implants. PMID:23037849

  18. Biphasic Peptide Amphiphile Nanomatrix Embedded with Hydroxyapatite Nanoparticles for Stimulated Osteoinductive Response

    PubMed Central

    Anderson, Joel M.; Patterson, Jessica L.; Vines, Jeremy B.; Javed, Amjad; Gilbert, Shawn R.; Jun, Ho-Wook

    2013-01-01

    Formation of the native bone extracellular matrix (ECM) provides an attractive template for bone tissue engineering. The structural support and biological complexity of bone ECM are provided within a composite microenvironment that consists of an organic fibrous network reinforced by inorganic hydroxyapatite (HA) nanoparticles. Recreating this biphasic assembly, a bone ECM analogous scaffold comprised of self-assembling peptide amphiphile (PA) nanofibers and interspersed HA nanoparticles was investigated. PAs were endowed with biomolecular ligand signaling using a synthetically inscribed peptide sequence (i.e. RGDS) and integrated with HA nanoparticles to form a biphasic nanomatrix hydrogel. It was hypothesized the biphasic hydrogel would induce osteogenic differentiation of human mesenchymal stem cells (hMSCs) and improve bone healing as mediated by RGDS ligand signaling within PA nanofibers and embedded HA mineralization source. Viscoelastic stability of the biphasic PA hydrogels was evaluated with different weight concentrations of HA for improved gelation. After demonstrating initial viability, long-term cellularity and osteoinduction of encapsulated hMSCs in different PA hydrogels were studied in vitro. Temporal progression of osteogenic maturation was assessed by gene expression of key markers. A preliminary animal study demonstrated bone healing capacity of the biphasic PA nanomatrix under physiological conditions using a critical size femoral defect rat model. The combination of RGDS ligand signaling and HA nanoparticles within the biphasic PA nanomatrix hydrogel demonstrated the most effective osteoinduction and comparative bone healing response. Therefore, the biphasic PA nanomatrix establishes a well-organized scaffold with increased similarity to natural bone ECM with the prospect for improved bone tissue regeneration. PMID:22077993

  19. Experimental study of osteoinduction using a new material as a carrier for bone morphogenetic protein-2.

    PubMed

    Koyama, Noriaki; Okubo, Yasunori; Nakao, Kazumasa; Osawa, Kenji; Bessho, Kazuhisa

    2011-06-01

    We evaluated the usefulness of artificial collagen as a new carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) by comparing it with that of atelopeptide collagen, which is derived from porcine skin, and which we have previously shown to be useful for the induction of bone. rhBMP-2 5μg with either atelopeptide collagen 3mg or artificial collagen 3mg was implanted into the calf muscle of 10-week-old Wistar rats (n=3 in each group). Three rats were given artificial collagen alone and acted as controls (n=3). Radiographic evaluation, histological analysis, and biochemical examinations were made on day 21 after implantation. Soft radiographs (wavelength 10-0.10nm) showed opaque shadows in both groups. Histological analysis showed that new bone had formed in both experimental groups. Endochondral ossification was found at the outermost edge of the implanted collagen in the atelopeptide group. However, there was less ossification in the implanted collagen in the artificial collagen group. On biochemical examination, alkaline phosphatase activity and calcium concentrations in both experimental groups were higher than in the control group, and were higher in the atelopeptide group than in the artificial collagen group. Our results suggest that artificial collagen is useful as a carrier for rhBMP-2 designed to promote the formation of new bone. PMID:20554359

  20. The homing of bone marrow MSCs to non-osseous sites for ectopic bone formation induced by osteoinductive calcium phosphate

    PubMed Central

    Song, Guodong; Habibovic, Pamela; Bao, Chongyun; Hu, Jing; van Blitterswijk, Clemens A.; Yuan, Huipin; Chen, Wenchuan; Xu, Hockin H.K.

    2013-01-01

    Osteoinductive biomaterials are promising for bone repair. There is no direct proof that bone marrow mesenchymal stem cells (BMSCs) home to non-osseous sites and participate in ectopic bone formation induced by osteoinductive bioceramics. The objective of this study was to use a sex-mismatched beagle dog model to investigate BMSC homing via blood circulation to participate in ectopic bone formation via osteoinductive biomaterial. BMSCs of male dogs were injected into female femoral marrow cavity. The survival and stable chimerism of donor BMSCs in recipients were confirmed with polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH). Biphasic calcium phosphate (BCP) granules were implanted in dorsal muscles of female dogs. Y chromosomes were detected in samples harvested from female dogs which had received male BMSCs. At 4 weeks, cells with Y-chromosomes were distributed in the new bone matrix throughout the BCP granule implant. At 6 weeks, cells with Y chromosomes were present in newly mineralized woven bone. TRAP positive osteoclast-like cells were observed in 4-week implants, and the number of such cells decreased from 4 to 6 weeks. These results show that osteoprogenitors were recruited from bone marrow and homed to ectopic site to serve as a cell source for calcium phosphate-induced bone formation. In conclusion, BMSCs were demonstrated to migrate from bone marrow through blood circulation to non-osseous bioceramic implant site to contribute to ectopic bone formation in a canine model. BCP induced new bone in muscles without growth factor delivery, showing excellent osteoinductivity that could be useful for bone tissue engineering. PMID:23298780

  1. Aseptic Raman spectroscopy can detect changes associated with the culture of human dental pulp stromal cells in osteoinductive culture

    PubMed Central

    Mitchell, Adam; Ashton, Lorna; Yang, Xuebin B.; Goodacre, Royston; Tomlinson, Matthew J.; Smith, Alistair

    2015-01-01

    There is an unmet need for the non-invasive characterisation of stem cells to facilitate the translation of cell-based therapies. Raman spectroscopy has proven utility in stem cell characterisation but as yet no method has been reported capable of taking repeated Raman measurements of living cells aseptically over time. The aim of this study was to determine if Raman spectroscopy could be used to monitor changes in a well characterised cell population (human dental pulp stromal cells (DPSCs)) by taking repeated Raman measurements from the same cell populations in osteoinductive culture over time and under aseptic conditions. DPSCs were isolated from extracted premolar teeth from 3 consenting donors. Following in vitro expansion, DPSCs were maintained for 28 days in osteo-inductive medium. Raman spectra were acquired from the cells at days 0, 3, 7, 10, 14 and 28. Principal component analysis (PCA) was carried out to assess if there was any temporal spectral variation. At day 28, osteoinduction was confirmed using alizarin red staining and qRT-PCR for alkaline phosphatase and osteocalcin. Alizarin red staining was positive in all samples at day 28 and significant increases in alkaline phosphatase (p < 0.001) and osteocalcin (p < 0.05) gene expression were also observed compared with day 0. PCA of the Raman data demonstrated trends in PC1 from days 0–10, influenced by protein associated features and PC2 from days 10–28, influenced by DNA/RNA associated features. We conclude that spectroscopy can be used to monitor changes in Raman signature with time associated with the osteoinduction of DPSCs using repeated measurements via an aseptic methodology. PMID:26374253

  2. Extracellular calcium and CaSR drive osteoinduction in mesenchymal stromal cells.

    PubMed

    González-Vázquez, Arlyng; Planell, Josep A; Engel, Elisabeth

    2014-06-01

    Bone is the main store of calcium and progenitor cells in the body. During the resorption process, the local calcium concentration reaches 8-40mM, and the surrounding cells are exposed to these fluctuations in calcium. This stimulus is a signal that is detected through the calcium sensing receptor (CaSR), which modulates chemotactic and proliferative G protein-dependent signaling pathways. The objective of the present work is to evaluate the roles of extracellular calcium ([Ca(2+)]o) and the CaSR in osteoinduction. Rat bone marrow mesenchymal stromal cells (rBMSCs) were stimulated with 10mM of Ca(2+). Several experiments were conducted to demonstrate the effect of [Ca(2+)]o on chemotaxis, proliferation and differentiation on the osteoblastic lineage. It was found that [Ca(2+)]o induces rBMSCs to migrate and proliferate in a concentration-dependent manner. Real-time polymerase chain reaction and immunofluorescence also revealed that 10mM Ca(2+) stimulates overexpression of osteogenic markers in rBMSCs, including alkaline phosphatase (ALP), bone sialoprotein, collagen Ia1 and osteocalcin. Functional assays determining ALP activity and mineralization tests both corroborate the increased expression of these markers in rBMSCs stimulated with Ca(2+). Moreover, CaSR blockage inhibited the cellular response to stimulation with high concentrations of [Ca(2+)]o, revealing that the CaSR is a key modulator of these cellular responses. PMID:24525034

  3. Osteoinductive nanohydroxyapatite bone substitute prepared via in situ hydrothermal transformation of cuttlefish bone.

    PubMed

    Hongmin, Li; Wei, Zhou; Xingrong, Yan; Jing, Wei; Wenxin, Geng; Jihong, Cui; Xin, Xie; Fulin, Chen

    2015-05-01

    The capacity to induce a rapid and controlled healing of bone defects is critical for a bone substitute. Previous studies have reported hydrothermal transformation (HT) of aragonite from cuttlebone (CB) to cuttlebone hydroxyapatite (CBHA). However, the biocompatibility and in vivo characteristic of CBHA have not been fully investigated. We fabricated CBHA via the in situ HT of aragonite from CB. This CBHA exhibited a highly porous structure and nanoscaled surface morphology with a significantly higher protein adsorption rate than CB. Marrow mesenchymal stem cells (MSCs) were seeded and cultured on the CBHA and CB to evaluate their influence on cell proliferation and differentiation. According to scanning electronic microscopy observation and MTT assay, the MSCs adhered and proliferated well on both the CBHA and CB. Compared with the cells on the CB, the MSCs on CBHA exhibited enhanced alkaline phosphatase activity and osteocalcin levels after 13 days of culture. In vivo testing revealed that CBHA could induce ectopic bone formation after implantation, while no bone formation being observed in the CB. These findings demonstrated that a nanoscaled and osteoinductive bone substitute could be produced by hydrothermally transforming an aragonite of CB into a hydroxyapatite. PMID:25115654

  4. In Vitro Effects of Strontium on Proliferation and Osteoinduction of Human Preadipocytes

    PubMed Central

    Nardone, V.; Zonefrati, R.; Mavilia, C.; Romagnoli, C.; Ciuffi, S.; Fabbri, S.; Palmini, G.; Galli, G.; Tanini, A.; Brandi, M. L.

    2015-01-01

    Development of tools to be used for in vivo bone tissue regeneration focuses on cellular models and differentiation processes. In searching for all the optimal sources, adipose tissue-derived mesenchymal stem cells (hADSCs or preadipocytes) are able to differentiate into osteoblasts with analogous characteristics to bone marrow mesenchymal stem cells, producing alkaline phosphatase (ALP), collagen, osteocalcin, and calcified nodules, mainly composed of hydroxyapatite (HA). The possibility to influence bone differentiation of stem cells encompasses local and systemic methods, including the use of drugs administered systemically. Among the latter, strontium ranelate (SR) represents an interesting compound, acting as an uncoupling factor that stimulates bone formation and inhibits bone resorption. The aim of our study was to evaluate the in vitro effects of a wide range of strontium (Sr2+) concentrations on proliferation, ALP activity, and mineralization of a novel finite clonal hADSCs cell line, named PA20-h5. Sr2+ promoted PA20-h5 cell proliferation while inducing the increase of ALP activity and gene expression as well as HA production during in vitro osteoinduction. These findings indicate a role for Sr2+ in supporting bone regeneration during the process of skeletal repair in general, and, more specifically, when cell therapies are applied. PMID:26240575

  5. BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects

    PubMed Central

    Xiong, Long; Zeng, Jianhua; Yao, Aihua; Tu, Qiquan; Li, Jingtang; Yan, Liang; Tang, Zhiming

    2015-01-01

    The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2), a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 μm) with a core (60±18 μm) and a mesoporous shell (180±42 m2/g surface area) were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 μg/mg). There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option for bone graft substitutes in bone regeneration. PMID:25609957

  6. Incorporation of sol-gel bioactive glass into PLGA improves mechanical properties and bioactivity of composite scaffolds and results in their osteoinductive properties.

    PubMed

    Filipowska, J; Pawlik, J; Cholewa-Kowalska, K; Tylko, G; Pamula, E; Niedzwiedzki, L; Szuta, M; Laczka, M; Osyczka, A M

    2014-12-01

    In this study, 3D porous bioactive composite scaffolds were produced and evaluated for their physico-chemical and biological properties. Polymer poly-L-lactide-co-glycolide (PLGA) matrix scaffolds were modified with sol-gel-derived bioactive glasses (SBGs) of CaO-SiO2-P2O5 systems. We hypothesized that SBG incorporation into PLGA matrix would improve the chemical and biological activity of composite materials as well as their mechanical properties. We applied two bioactive glasses, designated as S2 or A2, differing in the content of SiO2 and CaO (i.e. 80 mol% SiO2, 16 mol% CaO for S2 and 40 mol% SiO2, 52 mol% CaO for A2). The composites were characterized for their porosity, bioactivity, microstructure and mechanical properties. The osteoinductive properties of these composites were evaluated in human bone marrow stromal cell (hBMSC) cultures grown in either standard growth medium or treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) or dexamethasone (Dex). After incubation in simulated body fluid, calcium phosphate precipitates formed inside the pores of both A2-PLGA and S2-PLGA scaffolds. The compressive strength of the latter was increased slightly compared to PLGA. Both composites promoted superior hBMSC attachment to the material surface and stimulated the expression of several osteogenic markers in hBMSC compared to cells grown on unmodified PLGA. There were also marked differences in the response of hBMSC to composite scaffolds, depending on chemical compositions of the scaffolds and culture treatments. Compared to silica-rich S2-PLGA, hBMSC grown on calcium-rich A2-PLGA were overall less responsive to rhBMP-2 or Dex and the osteoinductive properties of these A2-PLGA scaffolds seemed partially dependent on their ability to induce BMP signaling in untreated hBMSC. Thus, beyond the ability of currently studied composites to enhance hBMSC osteogenesis, it may become possible to modulate the osteogenic response of hBMSC, depending on the

  7. Osteoinduction on acid and heat treated porous Ti metal samples in canine muscle.

    PubMed

    Kawai, Toshiyuki; Takemoto, Mitsuru; Fujibayashi, Shunsuke; Akiyama, Haruhiko; Tanaka, Masashi; Yamaguchi, Seiji; Pattanayak, Deepak K; Doi, Kenji; Matsushita, Tomiharu; Nakamura, Takashi; Kokubo, Tadashi; Matsuda, Shuichi

    2014-01-01

    Samples of porous Ti metal were subjected to different acid and heat treatments. Ectopic bone formation on specimens embedded in dog muscle was compared with the surface characteristics of the specimen. Treatment of the specimens by H2SO4/HCl and heating at 600 °C produced micrometer-scale roughness with surface layers composed of rutile phase of titanium dioxide. The acid- and heat-treated specimens induced ectopic bone formation within 6 months of implantation. A specimen treated using NaOH followed by HCl acid and then heat treatment produced nanometer-scale surface roughness with a surface layer composed of both rutile and anatase phases of titanium dioxide. These specimens also induced bone formation after 6 months of implantation. Both these specimens featured positive surface charge and good apatite-forming abilities in a simulated body fluid. The amount of the bone induced in the porous structure increased with apatite-forming ability and higher positive surface charge. Untreated porous Ti metal samples showed no bone formation even after 12 months. Specimens that were only heat treated featured a smooth surface composed of rutile. A mixed acid treatment produced specimens with micrometer-scale rough surfaces composed of titanium hydride. Both of them also showed no bone formation after 12 months. The specimens that showed no bone formation also featured almost zero surface charge and no apatite-forming ability. These results indicate that osteoinduction of these porous Ti metal samples is directly related to positive surface charge that facilitates formation of apatite on the metal surfaces in vitro. PMID:24520375

  8. Study on the anticorrosion, biocompatibility, and osteoinductivity of tantalum decorated with tantalum oxide nanotube array films.

    PubMed

    Wang, Na; Li, Hongyi; Wang, Jinshu; Chen, Su; Ma, Yuanping; Zhang, Zhenting

    2012-09-26

    With its excellent anticorrosion and biocompatibility, tantalum, as a promising endosseous implant or implant coating, is attracting more and more attention. For improving physicochemical property and biocompatibility, the research of tantalum surface modification has increased. Tantalum oxide (Ta(2)O(5)) nanotube films can be produced on tantalum by controlling the conditions of anodization and annealing. The objective of our present study was to investigate the influence of Ta(2)O(5) nanotube films on pure tantalum properties related with anticorrosion, protein adsorption, and biological function of rabbit bone mesenchymal stem cells (rBMSCs). The polarization curve was measured, the adsorption of bovine serum albumin and fibronectin to Ta(2)O(5) nanotubes was detected, and the morphology and actin cytoskeletons of the rBMSCs were observed via fluorescence microscopy, and the adhesion and proliferation of the rBMSCs, as well as the osteogenic differentiation potential on tantalum specimens, were examined quantificationally by MTT and real-time PCR technology. The results showed that Ta(2)O(5) nanotube films have high anticorrosion capability and can increase the protein adsorption to tantalum and promote the adhesion, proliferation, and differentiation of rBMSCs, as well as the mRNA expression of osteogenic gene such as Osterix, ALP, Collagen-I, and Osteocalcin on tantalum. This study suggests that Ta(2)O(5) nanotube films can improve the anticorrosion, biocompatibility, and osteoinduction of pure tantalum, which provides the theoretical elaboration for development of tantalum endosseous implant or implant coating to a certain extent. PMID:22894817

  9. Heat and Radiofrequency Plasma Glow Discharge Pretreatment of a Titanium Alloy: Eveidence for Enhanced Osteoinductive Properties

    PubMed Central

    Rapuano, Bruce E.; Singh, Herman; Boskey, Adele L.; Doty, Stephen B.; MacDonald, Daniel E.

    2013-01-01

    It is believed that orthopedic and implant longevity can be improved by optimizing fixation, or direct bone-implant contact, through the stimulation of new bone formation around the implant. The purpose of this study was to determine whether heat (600°C) or radiofrequency plasma glow discharge (RFGD) pretreatment of Ti6Al4V stimulated calcium-phosphate mineral formation in cultures of attached MC3T3 osteoprogenitor cells with or without a fibronectin coating. Calcium-phosphate mineral was analyzed by flame atomic absorption spectrophotometry, scanning electron microscopy (SEM)/electron dispersive X-ray microanalysis (EDAX) and Fourier transformed infrared spectroscopy (FTIR). RFGD and heat pretreatments produced a general pattern of increased total soluble calcium levels, although the effect of heat pretreatment was greater than that of RFGD. SEM/EDAX showed the presence of calcium-and phosphorus-containing particles on untreated and treated disks that were more numerous on fibronectin-coated disks. These particles were observed earliest (1 week) on RFGD-pretreated surfaces. FTIR analyses showed that the heat pretreatment produced a general pattern of increased levels of apatite mineral at 2–4 weeks; a greater effect was observed for fibronectin-coated disks compared to uncoated disks. The observed findings suggest that heat pretreatment of Ti6Al4V increased the total mass of the mineral formed in MC3T3 osteoprogenitor cell cultures more than RFGD while the latter pretreatment hastened the early deposition of mineral. These findings help to support the hypothesis that the pretreatments enhance the osteoinductive properties of the alloy. PMID:23494951

  10. Effect of Er:YAG laser holes on osteoinduction in demineralized rat calvarial allografts.

    PubMed

    O'Donnell, R J; Deutsch, T F; Flotte, R J; Lorente, C A; Tomford, W W; Mankin, H J; Schomacker, K T

    1996-01-01

    Massive cortical autografts and allografts have been found to incorporate into host bone very slowly and thus are subject to complications such as fatigue fracture and infection. In order to understand and improve the process of osteogenesis in these types of bone grafts, a new experimental model was developed using bone discs from rat calvaria prepared by demineralization and drilling of 0.5 mm diameter holes with a pulsed, 2.94 microns wavelength Erbium:Yttrium-Aluminum-Garnet laser. Four types of bone discs were analyzed: untreated (Type I), demineralized (Type II), laser-ablated (Type III), and laser-ablated then demineralized (Type IV). The discs were transplanted into a subcutaneous site in adult Sprague-Dawley rats and followed for as long as 6 weeks. Histologic analysis of the discs at weekly intervals with use of hematoxylin and eosin staining confirmed the presence of new bone growth in Type-II and Type-IV discs. The amount of new bone growth in each disc was estimated by determining the mineral x-ray attenuation coefficient, which is proportional to mineral density, from digitized radiographs of the discs. The results showed that the processes of demineralization (P < 0.001) and laser ablation with demineralization (p < 0.05) were both significant in enhancing new bone growth in this model. This study demonstrated that osteoinduction can be fostered in cortical bone through the processes of demineralization and laser ablation. To the extent that laser ablation may allow maintenance of structural integrity while altering the surface geometry in such a way as to promote ingrowth of new bone, this experimental model represents an advance in understanding how osteogenesis in cortical bone grafts might be improved. PMID:8618152

  11. HUBBLE VIEWS COLLOSSAL POLAR CYCLONE ON MARS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [left]: The discovery image of the Martian polar storm as seen in blue light (410 nm). The storm is located near 65 deg. N latitude and 85 deg. W longitude, and is more than 1000 miles (1600 km) across. The residual north polar water ice cap is at top. A belt of clouds like that seen in previous telescopic observations during this Martian season can also be seen in the planet's equatorial regions and northern mid-latitudes, as well as in the southern polar regions. The volcano Ascraeus Mons can be seen as a dark spot poking above the cloud deck near the western (morning) limb; this extinct volcano towers nearly 16 miles (25 km) above the surrounding plains, and is about 250 miles (400 km) across. [upper right]: Color polar view of the north polar region, showing the location of the storm relative to the classical bright and dark features in this area. The color composite data (410, 502, and 673 nm) indicate that the storm is fairly dust-free and therefore likely composed mostly of water ice clouds. The bright surface region beneath the eye of the storm can be seen clearly. This map covers the region north of 45 degrees latitude, and is oriented with 0 degrees longitude at the bottom. [lower right]: Enhanced orthographic view of the storm centered on 65 deg. N latitude, 85 deg. W longitude. The image has been processed to bring out additional detail in the storm's spiral cloud structures. The pictures were taken on April 27, 1999, with the NASA Hubble Space Telescope's Wide Field and Planetary Camera 2. Credit: Jim Bell (Cornell U.), Steve Lee (U. Colorado), Mike Wolff (SSI), and NASA

  12. Experimental and Computational Investigation of the Effect of Hydrophobicity on Aggregation and Osteoinductive Potential of BMP-2-Derived Peptide in a Hydrogel Matrix

    PubMed Central

    Moeinzadeh, Seyedsina; Barati, Danial; Sarvestani, Samaneh K.; Karimi, Tahereh

    2015-01-01

    An attractive approach to reduce the undesired side effects of bone morphogenetic proteins (BMPs) in regenerative medicine is to use osteoinductive peptide sequences derived from BMPs. Although the structure and function of BMPs have been studied extensively, there is limited data on structure and activity of BMP-derived peptides immobilized in hydrogels. The objective of this work was to investigate the effect of concentration and hydrophobicity of the BMP-2 peptide, corresponding to residues 73–92 of the knuckle epitope of BMP-2 protein, on peptide aggregation and osteogenic differentiation of human mesenchymal stem cells encapsulated in a polyethylene glycol (PEG) hydrogel. The peptide hydrophobicity was varied by capping PEG chain ends with short lactide segments. The BMP-2 peptide with a positive index of hydrophobicity had a critical micelle concentration (CMC) and formed aggregates in aqueous solution. Based on simulation results, there was a slight increase in the concentration of free peptide in solution with 1000-fold increase in peptide concentration. The dose-osteogenic response curve of the BMP-2 peptide was in the 0.0005–0.005 mM range, and osteoinductive potential of the BMP-2 peptide was significantly less than that of BMP-2 protein even at 1000-fold higher concentrations, which was attributed to peptide aggregation. Further, the peptide or PEG-peptide aggregates had significantly higher interaction energy with the cell membrane compared with the free peptide, which led to a higher nonspecific interaction with the cell membrane and loss of osteoinductive potential. Conjugation of the BMP-2 peptide to PEG increased CMC and osteoinductive potential of the peptide whereas conjugation to lactide-capped PEG reduced CMC and osteoinductive potential of the peptide. Experimental and simulation results revealed that osteoinductive potential of the BMP-2 peptide is correlated with its CMC and the free peptide concentration in aqueous medium and not the

  13. BMP2-Induced Inflammation Can Be Suppressed by the Osteoinductive Growth Factor NELL-1

    PubMed Central

    Shen, Jia; James, Aaron W.; Zara, Janette N.; Asatrian, Greg; Khadarian, Kevork; Zhang, James B.; Ho, Stephanie; Kim, Hyun Ju

    2013-01-01

    Bone-morphogenetic protein 2 (BMP2) is currently the only Food and Drug Administration-approved osteoinductive growth factor used in clinical settings for bone regeneration and repair. However, the use of BMP2 is encumbered by numerous clinical complications, including postoperative inflammation and life-threatening cervical swelling. Thus, methods to prevent BMP2-induced inflammation would have far-reaching clinical implications toward improving current BMP2-based methods for bone regeneration. For the first time, we investigate the potential role of the growth factor Nel-like molecule-1 (NELL-1) in inhibiting BMP2-induced inflammation. Adult rats underwent a femoral bone onlay procedure, treated with either BMP2 protein (4 mg/mL), NELL-1 protein (4 mg/mL), or both proteins combined. Animals were evaluated at 3, 7, and 14 days postoperatively by histology, histomorphometry, immunohistochemistry, and real-time PCR for markers of inflammation (TNFα, IL6). The relative levels of TNFα and IL6 in serum were also detected by ELISA. The mechanism for NELL-1's anti-inflammatory effect was further assessed through examining inflammatory markers and generation of reactive oxygen species (ROS) in the mouse embryonic fibroblast NIH3T3 cells. BMP2 significantly induced local inflammation, including an early and pronounced polymorphonuclear cell infiltration accompanied by increased expression of TNFα and IL6. Treatment with NELL-1 alone elicited no significant inflammatory response. However, NELL-1 significantly attenuated BMP2-induced inflammation by all markers and at all timepoints. These local findings were also confirmed using systemic serum inflammatory biomarkers (TNFα, IL6). In each case, NELL-1 fully reversed BMP2-induced systemic inflammation. Lastly, our findings were recapitulated in vitro, where NELL-1 suppressed BMP2 induced expression of inflammatory markers, as well as NF-κB transcriptional activity and generation of ROS. BMP2-induced inflammation is a

  14. Evaluation of osteoinduction and proliferation on nano-Sr-HAP: a novel orthopedic biomaterial for bone tissue regeneration.

    PubMed

    Hao, Yongqiang; Yan, Huanqing; Wang, Xuepeng; Zhu, Bangshang; Ning, Congqin; Ge, Shengfang

    2012-01-01

    Hydroxyapatite (HAP), a CaP compound similar to the mineral phase present in bone, has excellent biocompatibility but little osseous inductivity. In this study, we evaluated the novel nano-Sr-HAP, in which the calcium of hydroxyapatite was substituted with strontium, which acts as a bone-forming agent. Its biocompatibility and osteoinduction were assayed using marrow mesenchymal stem cells (MSCs) and osteoblasts (OBs) in vitro. We were able to demonstrate that nano-Sr-HAP supported increased OB cell adhesion, proliferation and viability up to 4 days in culture when compared with nano-HAP. MSCs cultured with nano-Sr-HAP showed higher alkaline phosphatase (ALP) activity. More extracellular mineralized nodules were found with nano-Sr-HAP compared to nano-HAP, especially in images of ALP staining. We suggest that nano-Sr-HAP powders possess osteoconductive and osteoinductive properties and have the potential to be used in the repair of bone defects caused by osteoporotic fractures. PMID:22523967

  15. Potentiated Osteoinductivity via Cotransfection with BMP-2 and VEGF Genes in Microencapsulated C2C12 Cells

    PubMed Central

    Shen, Yang; Qiao, Han; Fan, Qiming; Zhang, Shuhong; Tang, Tingting

    2015-01-01

    Microcapsules with entrapped cells hold great promise for repairing bone defects. Unfortunately, the osteoinductivity of microcapsules has been restricted by many factors, among which the deficiency of functional proteins is a significant priority. We potentiated the osteoinductivity of microencapsulated cells via cotransfection with BMP-2 and VEGF genes. Various tissue-derived mesenchymal stem cells and cell lines were compared for BMP-2 and VEGF cotransfection. Ethidium bromide (EB)/Calcein AM staining revealed that all of the cell categories could survive for 4 weeks after microencapsulation. An ELISA assay indicated that all microencapsulated BMP-2 or VEGF transfected cells could secrete gene products constitutively for 1 month. Particularly, the recombinant microencapsulated C2C12 cells released the most desirable level of BMP-2 and VEGF. Further experiments demonstrated that microencapsulated BMP-2 and VEGF cotransfected C2C12 cells generated both BMP-2 and VEGF for 4 weeks. Additionally, the cotransfection of BMP-2 and VEGF in microencapsulated C2C12 cells showed a stronger osteogenic induction against BMSCs than individual BMP-2-transfected microencapsulated C2C12 cells. These results demonstrated that the cotransfection of BMP-2 and VEGF into microencapsulated C2C12 cells is of potent utility for the potentiation of bone regeneration, which would provide a promising clinical strategy for cellular therapy in bone defects. PMID:26451370

  16. The effect of pulsed electromagnetic fields and dehydroepiandrosterone on viability and osteo-induction of human mesenchymal stem cells.

    PubMed

    Kaivosoja, Emilia; Sariola, Veikko; Chen, Yan; Konttinen, Yrjö T

    2015-01-01

    The hypothesis of this work was that human bone marrow-derived mesenchymal stem cells (MSCs) are regulated by pulsed electromagnetic fields (PEMFs) and by intracrine conversion of an adrenal prohormone to dihydrotestosterone. The effect of PEMF and dehydroepiandrosterone (DHEA) on viability and osteogenic differentiation of human MSCs and on the viability of osteoblastic SaOS-2 cells was evaluated. It was found that PEMF promoted the viability rate of both cell types, whereas DHEA decreased the viability rate in a concentration-dependent manner. PEMF did not have major effects on osteo-induction at this low seeding density level (3000 cells/cm(2) ). Instead, DHEA, after MSC-mediated and 5α-reductase-dependent conversion to dihydrotestosterone, clearly promoted the osteo-induction of MSCs induced with β-glyserophosphate, ascorbate and dexamethasone. Alkaline phosphatase (ALP), SMAD1, RUNX2, osteopontin (OP) and osteocalcin (OC) RNA levels were increased and alizarin red S- and hydroxyapatite-specific OsteoImage(TM) stainings disclosed a promoted mineralization process. In addition, DHEA increased OP and OC mRNA levels of non-induced MSCs. A sequential use of mitogenic PEMF early during the fracture healing, followed by later administration of DHEA with osteogenic differentiating effect, might be worth subjecting to a randomized clinical trial. PMID:23038647

  17. Osteogenic Embryoid Body-Derived Material Induces Bone Formation In Vivo

    PubMed Central

    Sutha, Ken; Schwartz, Zvi; Wang, Yun; Hyzy, Sharon; Boyan, Barbara D.; McDevitt, Todd C.

    2015-01-01

    The progressive loss of endogenous regenerative capacity that accompanies mammalian aging has been attributed at least in part to alterations in the extracellular matrix (ECM) composition of adult tissues. Thus, creation of a more regenerative microenvironment, analogous to embryonic morphogenesis, may be achieved via pluripotent embryonic stem cell (ESC) differentiation and derivation of devitalized materials as an alternative to decellularized adult tissues, such as demineralized bone matrix (DBM). Transplantation of devitalized ESC materials represents a novel approach to promote functional tissue regeneration and reduce the inherent batch-to-batch variability of allograft-derived materials. In this study, the osteoinductivity of embryoid body-derived material (EBM) was compared to DBM in a standard in vivo ectopic osteoinduction assay in nude mice. EBM derived from EBs differentiated for 10 days with osteogenic media (+β-glycerophosphate) exhibited similar osteoinductivity to active DBM (osteoinduction score = 2.50 ± 0.27 vs. 2.75 ± 0.16) based on histological scoring, and exceeded inactive DBM (1.13 ± 0.13, p < 0.005). Moreover, EBM stimulated formation of new bone, ossicles, and marrow spaces, similar to active DBM. The potent osteoinductivity of EBM demonstrates that morphogenic factors expressed by ESCs undergoing osteogenic differentiation yield a novel devitalized material capable of stimulating de novo bone formation in vivo. PMID:25961152

  18. Osteoconductivity and osteoinductivity of porous hydroxyapatite coatings deposited by liquid precursor plasma spraying: in vivo biological response study.

    PubMed

    Huang, Yi; He, Jing; Gan, Lu; Liu, Xiaoguang; Wu, Yao; Wu, Fang; Gu, Zhong-wei

    2014-12-01

    The beneficial effect of a porous structure on the biological functions of calcium phosphate bulk ceramic or scaffold has been well documented. Nevertheless, the effect of a porous structure on the in vivo performance of hydroxyapatite (HA) coatings has been rarely reported, partly due to the difficulty in synthesizing porous HA coatings suitable for commercial applications. In this study, we have carried out a systematic in vivo study of porous HA-coated Ti implants (with and without surface modification) prepared by the liquid precursor plasma spraying process, in terms of its osteoconductivity and osteoinductivity. The results suggest the clear advantage of the porous structure over the dense structure, despite the pore structure (about 48% porosity and less than 100 μm average pore size) being far from the ideal pore structure reported for bulk ceramic. The porous HA-coated implant significantly promotes early bone ingrowth at the pre-generated defective region, and early fixation at the bone-implant interface, especially at early implantation time (one month), showing about 120% and 40% increases respectively over those of the dense HA-coated implants prepared by the conventional atmospheric plasma spraying process. Moreover, the porous structure can be readily used to incorporate collagen/rh-BMP2, which demonstrates clear ectopic bone formation. Overall, the results suggest the augmentation of bone ingrowth is significant for HA coatings with a porous structure, which is critical for the early fixation and long-term stability of medical implants. PMID:25384201

  19. Titanium dental implants surface-immobilized with gold nanoparticles as osteoinductive agents for rapid osseointegration.

    PubMed

    Heo, Dong Nyoung; Ko, Wan-Kyu; Lee, Hak Rae; Lee, Sang Jin; Lee, Donghyun; Um, Soong Ho; Lee, Jung Haeng; Woo, Yi-Hyung; Zhang, Lijie Grace; Lee, Deok-Won; Kwon, Il Keun

    2016-05-01

    Gold nanoparticles (GNPs) are quite attractive materials for use as osteogenic agents due to their potential effects on the stimulation of osteoblast differentiation. In this study, an osseo-integrated titanium (Ti) implant surface coated with GNPs was used for promotion of bone regeneration. We prepared a silanized Ti surface by chemical treatment of (3-Mercaptopropyl) trimethoxysilane (MPTMS) and immobilized the GNP layer (Ti-GNP) on their surfaces via Au-S bonding. The GNP layer is uniformly immobilized on the surface and the layer covers the titanium oxide surface well, as confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The Ti-GNP was used to investigate the effectiveness of this system both in vitro and in vivo. The in vitro results showed that the Ti-GNP significantly enhances the osteogenic differentiation with increased mRNA expression of osteogenic differentiation specific genes in human adipose-derived stem cells (ADSCs). Furthermore, the in vivo results showed that Ti-GNP had a significant influence on the osseous interface formation. Through these in vitro and vivo tests, we found that Ti-GNP can be useful as osseo-integration inducing dental implants for formation of an osseous interface and maintenance of nascent bone formation. PMID:26874978

  20. Clinical Assessment of Low-dose Osteoinductive Protein as a Stand-alone Regimen in Self-reported Osteoarthritis

    PubMed Central

    Spinks, Katherine; Walker, Matthew; Scaffidi, James

    2015-01-01

    Context Osteoarthritis, sometimes called degenerative joint disease, is the most common form of arthritis. It affects more than 20 million people in the United States, who mostly are older than age 45 y. No specific treatment exists to halt the progressive cartilage degeneration of osteoarthritis or to repair the damaged cartilage. Alternatives to pharmaceuticals include natural therapies and nutritional supplements. Objective The present study examined the clinical response to daily supplementation with bioactive protein complex containing a collagen type 2 network, with associated growth factors, and osteoinductive proteins, known as bone morphogenetic proteins (BMPs). Design The research team designed an open-label preliminary study. Setting Joint evaluations were self-administered by participants at their residences. Participants Participants were 44 individuals with self-reported osteoarthritis in the hip, knee, or ankle (ie, in weight-bearing joints). Intervention Participants self-administered orally a low-dose form of the ingredient (ie, 150 mg of Cyplexinol® Standard, once daily for 4 wk). Outcome Measures Four parameters—pain intensity, frequency of pain, activity level, and strength—were evaluated using a visual analog scale (VAS), both at baseline and at the end of the 4-wk period. Results Pain intensity decreased 45% on a 10-cm VAS from 2.85 cm (P = .0001; 95% CI, 2.54, 3.16) at baseline to 1.41 cm (P = .0001; 95% CI, 1.18, 1.64) at wk 4. Pain frequency decreased 55% from 3.16 cm (P = .0001; 95% CI, 2.88, 3.44) at baseline to 1.22 cm (P = .0001; 95% CI, 0.85, 1.59) at wk 4. Activity level increased from 1.58 cm (P = .0001; 95% CI, 1.34, 1.82) at baseline to 2.91 cm (P = .0001; 95% CI, 2.71, 3.11) at wk 4. Strength increased 80% from 1.24 cm (P = .0001; 95% CI, 0.91, 1.57) at baseline to 2.10 cm (P = .0001; 95% CI, 1.73, 2.47) at wk 4. Conclusions The 44 participants reported subjective improvements in pain frequency and intensity as well as in

  1. Osteoinduction of Umbilical Cord and Palate Periosteum-Derived Mesenchymal Stem Cells on Poly-Co-Glycolytic Acid Nano-Microfibers

    PubMed Central

    Caballero, Montserrat; Pappa, Andrew; Roden, Katherine; Krochmal, Daniel J.; van Aalst, John A.

    2014-01-01

    The need for tissue engineered bone to treat complex craniofacial bone defects secondary to congenital anomalies, trauma, and cancer extirpation is sizeable. Traditional strategies for treatment have focused on autologous bone in younger patients and bone substitutes in older patients. However, the capacity for merging new technologies, including the creation of nano and microfiber scaffolds with advances in natal sources of stem cells, is crucial to improving our treatment options. The advantages of using smaller diameter fibers for scaffolding are two-fold: the similar fiber diameters mimic the in vivo extracellular matrix construct;, and smaller fibers also provide a dramatically increased surface area for cell-scaffold interactions. In this study, we compare the capacity for a polymer with Federal Drug Administration (FDA) approval for use in humans, poly-co-glycolytic acid (PLGA) from Delta polymer, to support osteoinduction of mesenchymal stem cells (MSCs) harvested from the umbilical cord (UC) and palate periosteum (PP). Proliferation of both UC- and PP-derived MSCs was improved on PLGA scaffolds. PLGA scaffolds promoted UC MSC differentiation (indicated by earlier gene expression and higher calcium deposition), but not in PP-derived MSCs. UC-derived MSCs on PLGA nano-micro-fiber scaffolds have potential clinical utility in providing solutions for craniofacial bone defects, with the added benefit of earlier availability. PMID:24691324

  2. Vesicular Galectin-3 levels decrease with donor age and contribute to the reduced osteo-inductive potential of human plasma derived extracellular vesicles

    PubMed Central

    Weilner, Sylvia; Keider, Verena; Winter, Melanie; Harreither, Eva; Salzer, Benjamin; Weiss, Florian; Schraml, Elisabeth; Messner, Paul; Pietschmann, Peter; Hildner, Florian; Gabriel, Christian; Redl, Heinz; Grillari-Voglauer, Regina; Grillari, Johannes

    2016-01-01

    Aging results in a decline of physiological functions and in reduced repair capacities, in part due to impaired regenerative power of stem cells, influenced by the systemic environment. In particular osteogenic differentiation capacity (ODC) of mesenchymal stem cells (MSCs) has been shown to decrease with age, thereby contributing to reduced bone formation and an increased fracture risk. Searching for systemic factors that might contribute to this age related decline of regenerative capacity led us to investigate plasma-derived extracellular vesicles (EVs). EVs of the elderly were found to inhibit osteogenesis compared to those of young individuals. By analyzing the differences in the vesicular content Galectin-3 was shown to be reduced in elderly-derived vesicles. While overexpression of Galectin-3 resulted in an enhanced ODC of MSCs, siRNA against Galectin-3 reduced osteogenesis. Modulation of intravesicular Galectin-3 levels correlated with an altered osteo-inductive potential indicating that vesicular Galectin-3 contributes to the biological response of MSCs to EVs. By site-directed mutagenesis we identified a phosphorylation-site on Galectin-3 mediating this effect. Finally, we showed that cell penetrating peptides comprising this phosphorylation-site are sufficient to increase ODC in MSCs. Therefore, we suggest that decrease of Galectin-3 in the plasma of elderly contributes to the age-related loss of ODC. PMID:26752347

  3. Vesicular Galectin-3 levels decrease with donor age and contribute to the reduced osteo-inductive potential of human plasma derived extracellular vesicles.

    PubMed

    Weilner, Sylvia; Keider, Verena; Winter, Melanie; Harreither, Eva; Salzer, Benjamin; Weiss, Florian; Schraml, Elisabeth; Messner, Paul; Pietschmann, Peter; Hildner, Florian; Gabriel, Christian; Redl, Heinz; Grillari-Voglauer, Regina; Grillari, Johannes

    2016-01-01

    Aging results in a decline of physiological functions and in reduced repair capacities, in part due to impaired regenerative power of stem cells, influenced by the systemic environment. In particular osteogenic differentiation capacity (ODC) of mesenchymal stem cells (MSCs) has been shown to decrease with age, thereby contributing to reduced bone formation and an increased fracture risk. Searching for systemic factors that might contribute to this age related decline of regenerative capacity led us to investigate plasma-derived extracellular vesicles (EVs). EVs of the elderly were found to inhibit osteogenesis compared to those of young individuals. By analyzing the differences in the vesicular content Galectin-3 was shown to be reduced in elderly-derived vesicles. While overexpression of Galectin-3 resulted in an enhanced ODC of MSCs, siRNA against Galectin-3 reduced osteogenesis. Modulation of intravesicular Galectin-3 levels correlated with an altered osteo-inductive potential indicating that vesicular Galectin-3 contributes to the biological response of MSCs to EVs. By site-directed mutagenesis we identified a phosphorylation-site on Galectin-3 mediating this effect. Finally, we showed that cell penetrating peptides comprising this phosphorylation-site are sufficient to increase ODC in MSCs. Therefore, we suggest that decrease of Galectin-3 in the plasma of elderly contributes to the age-related loss of ODC. PMID:26752347

  4. Bone-grafting materials in implant dentistry.

    PubMed

    Misch, C E; Dietsh, F

    1993-01-01

    There are three classes of bone-grafting materials based upon the mode of action. Autogenous bone is an organic material and forms bone by osteogenesis, osteoinduction, and osteoconduction. Allografts such as demineralized freeze-dried bone are osteoinductive and osteoconductive and may be cortical and/or trabecular in nature. Alloplasts such as hydroxyapatite and tricalcium phosphate may be synthetic or natural, vary in size, and are only osteoconductive. They can be divided into three types based upon the porosity of the product and include dense, macroporous, and microporous materials. In addition, alloplastic materials may be crystalline or amorphous. These materials have different properties and therefore indications. The use of the three classes of materials in diverse combinations depends upon the size and topography of the bony defect. Small defects or defects with four walls of host bone can be repaired with alloplasts alone or allografts in combination with alloplasts. The loss of three or more bony walls mandates the addition of autogenous bone to the graft or the use of a small pore membrane. The larger the defect, the more autogenous bone is required. The different indications of bone substitutes are discussed as to their specific applications in implant dentistry. PMID:8142935

  5. Fabrication of poly(ethylene glycol) hydrogel micropatterns with osteoinductive growth factors and evaluation of the effects on osteoblast activity and function

    NASA Astrophysics Data System (ADS)

    Subramani, K.; Birch, M. A.

    2006-09-01

    orthopaedic applications using osteoinductive PEG hydrogel micropatterns.

  6. Fabrication of electrospun silica-titania nanofibers with different silica content and evaluation of the morphology and osteoinductive properties.

    PubMed

    Wang, Xiaokun; Zhu, Jingxian; Yin, Ling; Liu, Shize; Zhang, Xin; Ao, Yingfang; Chen, Haifeng

    2012-12-01

    Ceramic-derived materials have shown enhanced osteogenic potential for bone tissue engineering applications. Silica is the major component of bioglass, and titania, the oxide complex of titanium, has been found to enhance osteoblast differentiation. In this study, three groups of sol-gel-derived silica-titania fibrous meshes with precursor ratios of Ti:Si = 7:3, 1:1, 3:7 were fabricated by electrospinning. The effects of silica content on the crystal phase and morphology of silica-titania hybrid nanofiber meshes were also analyzed by scanning electron microscopy, X-ray diffraction, and laser confocal microscopy. The osteogenic potential of the silica-titania meshes was evaluated by seeding mesenchymal stem cells (MSCs) on each mesh and determining cell number, osteodifferentiation markers, and osteopontin production over time. Our results show that cells proliferated throughout the mesh surfaces with similar morphology in all groups. Decreased cell proliferation was observed with the fiber meshes compared with glass controls, whereas cell differentiation toward osteoblast was enhanced on the mesh groups, especially on the Ti:Si = 7:3 group. These findings suggest that higher fiber diameter, degree of crystallization, and titania content of nanofibers can enhance osteodifferentiation of MSCs. PMID:22767362

  7. Three-dimensional CaP/gelatin lattice scaffolds with integrated osteoinductive surface topographies for bone tissue engineering.

    PubMed

    Nadeem, Danish; Smith, Carol-Anne; Dalby, Matthew J; Meek, R M Dominic; Lin, Sien; Li, Gang; Su, Bo

    2015-01-01

    Surface topography is known to influence stem cells and has been widely used as physical stimuli to modulate cellular behaviour including adhesion, proliferation and differentiation on 2D surfaces. Integration of well-defined surface topography into three-dimensional (3D) scaffolds for tissue engineering would be useful to direct the cell fate for intended applications. Technical challenges are remaining as how to fabricate such 3D scaffolds with controlled surface topography from a range of biodegradable and biocompatible materials. In this paper, a novel fabrication process using computer numerically controlled machining and lamination is reported to make 3D calcium phosphate/gelatin composite scaffolds with integrated surface micropatterns that are introduced by embossing prior to machining. Geometric analysis shows that this method is versatile and can be used to make a wide range of lattices with porosities that meet the basic requirements for bone tissue engineering. Both in vitro and in vivo studies show that micropatterned composite scaffolds with surfaces comprising 40 μm pits and 50 μm grooves were optimal for improved osteogenesis. The results have demonstrated the potential of a novel fabrication process for producing cell-instructive scaffolds with designed surface topographies to induce specific tissue regeneration. PMID:25562325

  8. Assessment of osteoinduction using a porous hydroxyapatite coating prepared by micro-arc oxidation on a new titanium alloy.

    PubMed

    Jing, Wensen; Zhang, Minghua; Jin, Lei; Zhao, Jian; Gao, Qing; Ren, Min; Fan, Qingyu

    2015-12-01

    Surface modification and material improvement is now an important way to improve the osseointegration between bone and uncemented prothesis. The purpose of this study was to investigate the bone ingrowth potential of porous hydroxyapatite (HA) coatings prepared by micro-arc oxidation (MAO) on Ti-3Zr-2Sn-3Mo-25Nb, a new titanium alloy. HA-coated specimens were implanted in the left proximal femoral medullary canal of beagles for 4, 12, and 24 weeks, and uncoated specimens were implanted in the right as a control. The surface morphology and phase composition were investigated with environmental scanning electron microscopy and X-ray diffractometry. The bone ingrowth was assessed by histomorphometry. A pull-out test was performed to assess the mechanical performance of the bone-implant interface. A porous coating was well prepared on the new titanium alloy by using the MAO method. The bone-to-implant contact was significantly higher for the HA-coated group compared to that in the uncoated group. Mechanical tests showed that the HA-coated group had significantly higher maximum force at the bone-implant interface compared to the uncoated specimens. MAO is a suitable coating approach for this new titanium alloy. The HA coating prepared by this approach can significantly promote bone ingrowth and the mechanical performance of the bone-implant interface. PMID:26306772

  9. Materialism.

    PubMed

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. PMID:26301463

  10. Preparation and application of highly porous aerogel-based bioactive materials in dentistry

    NASA Astrophysics Data System (ADS)

    Kuttor, Andrea; Szalóki, Melinda; Rente, Tünde; Kerényi, Farkas; Bakó, József; Fábián, István; Lázár, István; Jenei, Attila; Hegedüs, Csaba

    2014-03-01

    In this study, the possibility of preparation and application of highly porous silica aerogel-based bioactive materials are presented. The aerogel was combined with hydroxyapatite and β-tricalcium phosphate as bioactive and osteoinductive agents. The porosity of aerogels was in the mesoporous region with a maximum pore diameter of 7.4 and 12.7 nm for the composite materials. The newly developed bioactive materials were characterized by scanning electron microscopy. The in vitro biological effect of these modified surfaces was also tested on SAOS-2 osteogenic sarcoma cells by confocal laser scanning microscopy.

  11. Materials

    NASA Technical Reports Server (NTRS)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  12. Tuning cellular responses to BMP-2 with material surfaces

    PubMed Central

    Picart, Catherine; Cavalcanti-Adam, Elisabetta Ada

    2016-01-01

    Bone morphogenetic protein 2 (BMP-2) has been known for decades as a strong osteoinductive factor and for clinical applications is combined solely with collagen as carrier material. The growing concerns regarding side effects and the importance of BMP-2 in several developmental and physiological processes have raised the need to improve the design of materials by controlling BMP-2 presentation. Inspired by the natural cell environment, new material surfaces have been engineered and tailored to provide both physical and chemical cues that regulate BMP-2 activity. Here we describe surfaces designed to present BMP-2 to cells in a spatially and temporally controlled manner. This is achieved by trapping BMP-2 using physicochemical interactions, either covalently grafted or combined with other extracellular matrix components. In the near future, we anticipate that material science and biology will integrate and further develop tools for in vitro studies and potentially bring some of them toward in vivo applications. PMID:26704296

  13. Tuning cellular responses to BMP-2 with material surfaces.

    PubMed

    Migliorini, Elisa; Valat, Anne; Picart, Catherine; Cavalcanti-Adam, Elisabetta Ada

    2016-02-01

    Bone morphogenetic protein 2 (BMP-2) has been known for decades as a strong osteoinductive factor and for clinical applications is combined solely with collagen as carrier material. The growing concerns regarding side effects and the importance of BMP-2 in several developmental and physiological processes have raised the need to improve the design of materials by controlling BMP-2 presentation. Inspired by the natural cell environment, new material surfaces have been engineered and tailored to provide both physical and chemical cues that regulate BMP-2 activity. Here we describe surfaces designed to present BMP-2 to cells in a spatially and temporally controlled manner. This is achieved by trapping BMP-2 using physicochemical interactions, either covalently grafted or combined with other extracellular matrix components. In the near future, we anticipate that material science and biology will integrate and further develop tools for in vitro studies and potentially bring some of them toward in vivo applications. PMID:26704296

  14. Use of Carboxymethyl Cellulose and Collagen Carrier with Equine Bone Lyophilisate Suggests Late Onset Bone Regenerative Effect in a Humerus Drill Defect – A Pilot Study in Six Sheep

    PubMed Central

    Jensen, Jonas; Foldager, Casper Bindzus; Jakobsen, Thomas Vestergaard; Søballe, Kjeld; Bünger, Cody; Baas, Jorgen

    2010-01-01

    We assessed the use of a filler compound together with the osteoinductive demineralized bone matrix (DBM), Colloss E. The filler was comprised of carboxymethyl-cellulose and collagen type 1. The purpose of the study was to see if the filler compound would enhance the bone formation and distribute the osteoinductive stimulus throughout the bone defect. Six sheep underwent a bilateral humerus drill defect. The drill hole was filled with a compound consisting of 100 mg CMC, 100 mg collagen powder, and 1 ccm autologous full blood in one side, and a combination of this filler compound and 20 mg Colloss E in the other. The animals were divided into three groups of two animals and observed for 8, 12 and 16 weeks. Drill holes was evaluated using quantitative computed tomography (QCT), micro computed tomography (µCT) and histomorphometry. Mean total bone mineral density (BMD) of each implantation site was calculated with both QCT and µCT. Bone volume to total volume (BV/TV) was analyzed using µCT and histomorphometry. Although not statistically significant, results showed increased bone BMD after 16 weeks in µCT data and an increased BV/TV after 16 weeks in both µCT and histology. Correlation between QCT and µCT was R2 = 0.804. Correlation between histomorphometry and µCT BV/TV data was R2 = 0.8935 and with an average overrepresentation of 8.2% in histomorphometry. In conclusion the CMC-Collagen + Colloss E filler seems like a viable osteogenic bone filler mid- to long term. A correlation was found between the analytical methods used in this study. PMID:20582241

  15. Materials characteristics of uncoated/ceramic-coated implant materials.

    PubMed

    Lacefield, W R

    1999-06-01

    In this paper, the biocompatibility of dental implant materials is discussed in the context of both the mechanical characteristics of the materials and the type of surface presented to the surrounding tissues. The proper functioning of the implant depends on whether it possesses the strength necessary to withstand loading within the expected range, with other properties such as elongation being of importance in some instances. A suitable modulus of elasticity may be of major importance in situations when optimum load transmission from the implant into the surrounding bone is key to the successful functioning of the device. Dental implants present a wide range of surfaces to the surrounding tissues based on surface composition, texture, charge energy, and cleanliness (sterility). Metallic implants are characterized by protective oxide layers, but ion release is still common with these materials, and is a function of passivation state, composition, and corrosion potential. An effective surface treatment for titanium appears to be passivation or anodization in a suitable solution prior to implantation. Inert ceramic surfaces exhibit minimal ion release, but are similar to metals in that they do not form a high energy bond to the surrounding bone. Some of the newly developed dental implant alloys such as titanium alloys, which contain zirconium and niobium, and high-strength ceramics such as zirconia may offer some advantages (such as lower modulus of elasticity) over the conventional materials. Calcium phosphate ceramic coatings are commonly used to convert metallic surfaces into a more bioactive state and typically cause faster bone apposition. There is a wide range of ceramic coatings containing calcium and phosphorus, with the primary difference in many of these materials being in the rate of ion release. Although their long-term success rate is unknown, the calcium phosphate surfaces seem to have a higher potential for attachment of osteoinductive agents than do

  16. Tof-Sims Application for Evaluating the Atomic Structure of New Bone Substitute Material

    NASA Astrophysics Data System (ADS)

    Oteri, G.; Pisanom, M.; Cicciù, M.

    2016-05-01

    The aim of this experimental study is to evaluate, in vitro, the chemical composition and the micromorphological structure of a bone substitute material surface. This material is based on calcium triphosphate and hydroxyapatite microgranules. Some results of a preliminary surface study of the above mentioned bioceramic materials are reported. The study has been carried out by means of time-of-flight secondary ion mass spectrometry (TOF-SIMS), complemented by X-ray photoelectron spectrometry (XPS) measurements. Whereas XPS data supplies the average surface composition of the system, TOF-SIMS supplies laterally and depth resolved information on the sample. This preliminary study confirms the properties of osteoconduction and scaffold features of the material. Moreover, a possible osteoinductive capability could be due to the presence of surface micropores, which could help in the attraction of bone morphogenetic protein (BMP), thus promoting the osteogenesis.

  17. Synchrotron X-ray bio-imaging of natural and synthetic bone-graft materials in an aqueous environment

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Gun; Bark, Chung Wung

    2014-11-01

    Bone-graft materials in dentistry have osteoinductive and osteoconductive abilities, which depend on their microstructural characteristics, such as their porosity, particle size, micro channels, and absorption. These characteristics have been observed using various imaging techniques, such as optical microscopy and scanning electron microscopy (SEM). However, most techniques cannot provide images in water, even though graft materials in vivo are invariably in contact with different water-based fluids. Synchrotron X-ray imaging allows sample microenvironments to be controlled as X-ray beams easily penetrate air and water. In this report, we used the synchrotron X-ray imaging technique to provide in-situ images of various bone-graft materials in aqueous environments. We observed internal microstructural images of bone-graft materials in real-time in 0.9% saline solution and interactions between bone-graft materials and saline, that is, hydration patterns and bone-graft expansion.

  18. The materials used in bone tissue engineering

    SciTech Connect

    Tereshchenko, V. P. Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M.

    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.

  19. The materials used in bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Tereshchenko, V. P.; Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M.

    2015-11-01

    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.

  20. Is Graphene a Promising Nano-Material for Promoting Surface Modification of Implants or Scaffold Materials in Bone Tissue Engineering?

    PubMed Central

    Gu, Ming; Liu, Yunsong; Chen, Tong; Du, Feng; Zhao, Xianghui; Xiong, Chunyang

    2014-01-01

    Bone tissue engineering promises to restore bone defects that are caused by severe trauma, congenital malformations, tumors, and nonunion fractures. How to effectively promote the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) or seed cells has become a hot topic in this field. Many researchers are studying the ways of conferring a pro-osteodifferentiation or osteoinductive capability on implants or scaffold materials, where osteogenesis of seed cells is promoted. Graphene (G) provides a new kind of coating material that may confer the pro-osteodifferentiation capability on implants and scaffold materials by surface modification. Here, we review recent studies on the effects of graphene on surface modifications of implants or scaffold materials. The ability of graphene to improve the mechanical and biological properties of implants or scaffold materials, such as nitinol and carbon nanotubes, and its ability to promote the adhesion, proliferation, and osteogenic differentiation of MSCs or osteoblasts have been demonstrated in several studies. Most previous studies were performed in vitro, but further studies will explore the mechanisms of graphene's effects on bone regeneration, its in vivo biocompatibility, its ability to promote osteodifferentiation, and its potential applications in bone tissue engineering. PMID:24447041

  1. Is graphene a promising nano-material for promoting surface modification of implants or scaffold materials in bone tissue engineering?

    PubMed

    Gu, Ming; Liu, Yunsong; Chen, Tong; Du, Feng; Zhao, Xianghui; Xiong, Chunyang; Zhou, Yongsheng

    2014-10-01

    Bone tissue engineering promises to restore bone defects that are caused by severe trauma, congenital malformations, tumors, and nonunion fractures. How to effectively promote the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) or seed cells has become a hot topic in this field. Many researchers are studying the ways of conferring a pro-osteodifferentiation or osteoinductive capability on implants or scaffold materials, where osteogenesis of seed cells is promoted. Graphene (G) provides a new kind of coating material that may confer the pro-osteodifferentiation capability on implants and scaffold materials by surface modification. Here, we review recent studies on the effects of graphene on surface modifications of implants or scaffold materials. The ability of graphene to improve the mechanical and biological properties of implants or scaffold materials, such as nitinol and carbon nanotubes, and its ability to promote the adhesion, proliferation, and osteogenic differentiation of MSCs or osteoblasts have been demonstrated in several studies. Most previous studies were performed in vitro, but further studies will explore the mechanisms of graphene's effects on bone regeneration, its in vivo biocompatibility, its ability to promote osteodifferentiation, and its potential applications in bone tissue engineering. PMID:24447041

  2. Enhancement of the Regenerative Potential of Anorganic Bovine Bone Graft Utilizing a Polyglutamate-Modified BMP2 Peptide with Improved Binding to Calcium-Containing Materials.

    PubMed

    Bain, Jennifer L; Bonvallet, Paul P; Abou-Arraj, Ramzi V; Schupbach, Peter; Reddy, Michael S; Bellis, Susan L

    2015-09-01

    Autogenous bone is the gold standard material for bone grafting in craniofacial and orthopedic regenerative medicine. However, due to complications associated with harvesting donor bone, clinicians often use commercial graft materials that may lose their osteoinductivity due to processing. This study was aimed to functionalize one of these materials, anorganic bovine bone (ABB), with osteoinductive peptides to enhance regenerative capacity. Two peptides known to induce osteoblastic differentiation of mesenchymal stem cells were evaluated: (1) DGEA, an amino acid motif within collagen I and (2) a biomimetic peptide derived from bone morphogenic protein 2 (BMP2pep). To achieve directed coupling of the peptides to the graft surface, the peptides were engineered with a heptaglutamate domain (E7), which confers specific binding to calcium moieties within bone mineral. Peptides with the E7 domain exhibited greater anchoring to ABB than unmodified peptides, and E7 peptides were retained on ABB for at least 8 weeks in vivo. To assess the osteoinductive potential of the peptide-conjugated ABB, ectopic bone formation was evaluated utilizing a rat subcutaneous pouch model. ABB conjugated with full-length recombinant BMP2 (rBMP2) was also implanted as a model for current clinical treatments utilizing rBMP2 passively adsorbed to carriers. These studies showed that E7BMP2pep/ABB samples induced more new bone formation than all other peptides, and an equivalent amount of new bone as compared with rBMP2/ABB. A mandibular defect model was also used to examine intrabony healing of peptide-conjugated ABB. Bone healing was monitored at varying time points by positron emission tomography imaging with (18)F-NaF, and it was found that the E7BMP2pep/ABB group had greater bone metabolic activity than all other groups, including rBMP2/ABB. Importantly, animals implanted with rBMP2/ABB exhibited complications, including inflammation and formation of cataract-like lesions in the eye, whereas

  3. New Coll-HA/BT composite materials for hard tissue engineering.

    PubMed

    Zanfir, Andrei Vlad; Voicu, Georgeta; Busuioc, Cristina; Jinga, Sorin Ion; Albu, Madalina Georgiana; Iordache, Florin

    2016-05-01

    The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen-hydroxyapatite/barium titanate (Coll-HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol-gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll-HA and Coll-HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll-HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT. PMID:26952486

  4. A scanning electron microscopic study of in vitro toxicity of ethylene-oxide-sterilized bone repair materials.

    PubMed

    Zislis, T; Martin, S A; Cerbas, E; Heath, J R; Mansfield, J L; Hollinger, J O

    1989-01-01

    Polylactic acid (PLA) and polyglycolic acid (PGA) have been under investigation for use in the management of hard- and soft-tissue wounds. Current research has included the incorporation of osteo-inductive substances into a PLA-PGA copolymer alloplastic implant material for enhancement of the healing of osseous defects. Conventional methods of sterilization--such as dry heat, steam heat, or 60Co--tend either to destroy or attenuate osteo-inductive activity and alter polymer biodegradation. Ethylene oxide (EO) gas sterilization is currently being tested as an alternate method. This study examined the relationship of EO-induced cytotoxicity to the length of time of polymer aeration following EO sterilization. Three groups of copolymer implant discs were studied: (1) 50:50 PLA-PGA copolymer, (2) PLA-PGA polymer with hydroxyapatite (HA), and (3) PLA-PGA with autolyzed, antigen-extracted (AA) bone particles. Polymer discs, as well as particulate HA and AA bone controls, were sterilized with EO for 12 hours. Following periods of two weeks, one week, one day, or no subsequent vacuum aeration, samples were placed into 24-well culture plates. A suspension of human fibroblasts was added to each well. Cell growth and attachment were permitted for 24 hours. Medium was then removed, and solutions for cell fixation, buffer washing, and dehydration were added to each well. SEM examination revealed changes in cell growth with increasing periods of aeration suggestive of increasing cell vitality. Cells growing on discs having no aeration were small, round, and lobulated, whereas those of seven to 14 days' aeration were more numerous, and flattened with many microvilli, pseudopodia, and dendritic processes, features consistent with normal cell morphology. These results suggest that EO-sterilized polymer implants should be aerated for least seven to 14 days prior to surgical use. PMID:2561372

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

    NASA Astrophysics Data System (ADS)

    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.

  6. The novel material: Organosilanes crosslinked gelatin its characteristics and potentials for tissue engineering applications

    NASA Astrophysics Data System (ADS)

    Kwon, Bosun

    A typical tissue engineering approach involves combining three elements: a tissue scaffold, living cells, and cell signaling molecules, to regenerate a damaged tissue or organ. Tissue scaffold is the emerging key technology for tissue engineering applications. In this study, silane (glycidoxypropyltrimethoxy silane, GPMS) containing an epoxide group has been employed to crosslink gelatin and improve its deficient properties. However, GPMS modified gelatin has lower elasticity and hydrophobic structure due to its dense structure. These drawbacks were solved with the use of fructose as a spacer and another silane containing amine groups (aminopropyltriethoxysilane, APES) for the formation of longer bridge between two silanes. Furthermore, an "optimum" 2D or 3D silane-crosslinked system showed more wettable IPN structure due to many organic functional groups on its surface which can support cell attachment, migration and proliferation and allow interactions with biomolecules such as growth factors, providing lower toxicity. When silane modified gelatin(GS) was introduced to hydroxyapatite(HA) as a coating material, it yielded greater compressive strength and optimized the release of growth factors and stimulated osteogenic differentiation in vivo and in vitro. Also, GS, working as a DBM carrier, significantly enhanced the characteristics of DBM with adjustable load resistance, while maintaining the innate osteogenic properties of DBM. GS revealed to be a good candidate for osteoconductive and osteoinductive bone grafts, when combined with biomimetic material.

  7. A glycosaminoglycan mimetic peptide nanofiber gel as an osteoinductive scaffold.

    PubMed

    Tansik, Gulistan; Kilic, Erden; Beter, Mustafa; Demiralp, Bahtiyar; Kiziltas Sendur, Gullu; Can, Nuray; Ozkan, Huseyin; Ergul, Elif; Guler, Mustafa O; Tekinay, Ayse B

    2016-08-16

    Biomineralization of the extracellular matrix (ECM) plays a crucial role in bone formation. Functional and structural biomimetic native bone ECM components can therefore be used to change the fate of stem cells and induce bone regeneration and mineralization. Glycosaminoglycan (GAG) mimetic peptide nanofibers can interact with several growth factors. These nanostructures are capable of enhancing the osteogenic activity and mineral deposition of osteoblastic cells, which is indicative of their potential application in bone tissue regeneration. In this study, we investigated the potential of GAG-mimetic peptide nanofibers to promote the osteogenic differentiation of rat mesenchymal stem cells (rMSCs) in vitro and enhance the bone regeneration and biomineralization process in vivo in a rabbit tibial bone defect model. Alkaline phosphatase (ALP) activity and Alizarin red staining results suggested that osteogenic differentiation is enhanced when rMSCs are cultured on GAG-mimetic peptide nanofibers. Moreover, osteogenic marker genes were shown to be upregulated in the presence of the peptide nanofiber system. Histological and micro-computed tomography (Micro-CT) observations of regenerated bone defects in rabbit tibia bone also suggested that the injection of a GAG-mimetic nanofiber gel supports cortical bone deposition by enhancing the secretion of an inorganic mineral matrix. The volume of the repaired cortical bone was higher in GAG-PA gel injected animals. The overall results indicate that GAG-mimetic peptide nanofibers can be utilized effectively as a new bioactive platform for bone regeneration. PMID:27447002

  8. Sustainable materials

    NASA Astrophysics Data System (ADS)

    Allwood, Julian M.

    2016-01-01

    Materials influence every aspect of the energy system; therefore, as well as developing new materials for energy generation, materials scientists should engage in public debate about the limitations of future innovations and the conservation of existing materials.

  9. Improvement of β-TCP/PLLA biodegradable material by surface modification with stearic acid.

    PubMed

    Ma, Fengcang; Chen, Sai; Liu, Ping; Geng, Fang; Li, Wei; Liu, Xinkuan; He, Daihua; Pan, Deng

    2016-05-01

    Poly-l-lactide (PLLA) is a biodegradable polymer and used widely. Incorporation of beta tricalcium phosphate (β-TCP) into PLLA can enhance its osteoinductive properties. But the interfacial layer between β-TCP particles with PLLA matrix is easy to be destroyed due to inferior interfacial compatibility of the organic/inorganic material. In this work, a method of β-TCP surface modification with stearic acid was investigated to improve the β-TCP/PLLA biomaterial. The effects of surface modification on the β-TCP were investigated by FTIR, XPS, TGA and CA. It was found that the stearic acid reacted with β-TCP and oxhydryl was formed during the surface modification. Hydrophilicity of untreated or modified β-TCP/PLLA composite was increased by the addition of 10wt.% β-TCP, but it decreased as the addition amount increased from 10wt.% to 20wt.%. Two models were suggested to describe the effect of β-TCP concentration on CA of the composites. Mechanical properties of β-TCP/PLLA composites were tested by bending and tensile tests. Fractures of the composites after mechanical test were observed by SEM. It was found that surface modification with stearic acid improved bending and tensile strengths of the β-TCP/PLLA composites obviously. The SEM results indicated that surface modification decreased the probability of interface debonding between fillers and matrix under load. PMID:26952440

  10. Examining porous bio-active glass as a potential osteo-odonto-keratoprosthetic skirt material.

    PubMed

    Huhtinen, Reeta; Sandeman, Susan; Rose, Susanna; Fok, Elsie; Howell, Carol; Fröberg, Linda; Moritz, Niko; Hupa, Leena; Lloyd, Andrew

    2013-05-01

    Bio-active glass has been developed for use as a bone substitute with strong osteo-inductive capacity and the ability to form strong bonds with soft and hard tissue. The ability of this material to enhance tissue in-growth suggests its potential use as a substitute for the dental laminate of an osteo-odonto-keratoprosthesis. A preliminary in vitro investigation of porous bio-active glass as an OOKP skirt material was carried out. Porous glass structures were manufactured from bio-active glasses 1-98 and 28-04 containing varying oxide formulation (1-98, 28-04) and particle size range (250-315 μm for 1-98 and 28-04a, 315-500 μm for 28-04b). Dissolution of the porous glass structure and its effect on pH was measured. Structural 2D and 3D analysis of porous structures were performed. Cell culture experiments were carried out to study keratocyte adhesion and the inflammatory response induced by the porous glass materials. The dissolution results suggested that the porous structure made out of 1-98 dissolves faster than the structures made from glass 28-04. pH experiments showed that the dissolution of the porous glass increased the pH of the surrounding solution. The cell culture results showed that keratocytes adhered onto the surface of each of the porous glass structures, but cell adhesion and spreading was greatest for the 98a bio-glass. Cytokine production by all porous glass samples was similar to that of the negative control indicating that the glasses do not induce a cytokine driven inflammatory response. Cell culture results support the potential use of synthetic porous bio-glass as an OOKP skirt material in terms of limited inflammatory potential and capacity to induce and support tissue ingrowth. PMID:23386212

  11. Understanding Materials

    ERIC Educational Resources Information Center

    Katsioloudis, Petros J.

    2010-01-01

    Almost everything people have ever done has involved materials. Historical evidence indicates that "engineered materials" have been available and utilized for the benefit of humankind since the Neolithic period, beginning about 10,000 BC. Some of these materials have been in existence for thousands of years. At first, materials consisted of wood,…

  12. The effect of plasma surface treatment on the bioactivity of titanium implant materials (in vitro)

    PubMed Central

    Abdelrahim, Ramy A.; Badr, Nadia A.; Baroudi, Kusai

    2016-01-01

    Background: The surface of an implantable biomaterial plays a very important role in determining the biocompatibility, osteoinduction, and osteointegration of implants because it is in intimate contact with the host bone and soft tissues. Objective: This study was aimed to assess the effect of plasma surface treatment on the bioactivity of titanium alloy (Ti–6Al–4V). Materials and Methods: Fifteen titanium alloy samples were used in this study. The samples were divided into three groups (with five samples in each group). Five samples were kept untreated and served as control (group A). Another five plasma samples were sprayed for nitrogen ion implantation on their surfaces (group B) and the last five samples were pre-etched with acid before plasma treatment (group C). All the investigated samples were immersed for 7 days in Hank's balanced salt solution (HBSS) which was used as a simulating body fluid (SBF) at pH 7.4 and 37°C. HBSS was renewed every 3 days. The different surfaces were characterized by X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDXA), and Fourier Transformation Infrared Spectroscopy (FTIR). Results: Nitriding of Ti-alloy samples via plasma nitrogen ion implantation increased the bioactivity of titanium. Moreover, the surface topography affected the chemical structure of the formed apatite. Increasing the surface roughness enhanced the bioactivity of the implant material. Conclusions: Nitridation can be exploited as an effective way to promote the formation of bone-like material on the implant surface. PMID:27011927

  13. Hazardous materials

    MedlinePlus

    ... people how to work with hazardous materials and waste. There are many different kinds of hazardous materials, including: Chemicals, like some that are used for cleaning Drugs, like chemotherapy to treat cancer Radioactive material that is used for x-rays or ...

  14. Study of bone-like hydroxyapatite/polyamino acid composite materials for their biological properties and effects on the reconstruction of long bone defects

    PubMed Central

    Yan, Ling; Jiang, Dian-ming

    2015-01-01

    Purpose The purpose of this study was to investigate the effect of bone-like hydroxyapatite/polyamino acid (BHA/PAA) in the osteogenesis and reconstruction of long segmental bone defects. Methods In vitro, MG63 cells were cultured with BHA/PAA. The osteoinductive activity of the BHA/PAA material was evaluated using inverted microscopy, scanning electron microscopy, MTT proliferation assay, and the determination of alkaline phosphatase activity and Ca2+ content. In vivo, the radial bone defect was made in 20 New Zealand White rabbits, and then these animal were randomly divided into two groups (n=10), the experimental group (with BHA/PAA) and the control group (without BHA/PAA). Postoperatively, the osteogenesis effect of BHA/PAA was evaluated through X-ray, hematoxylin–eosin staining, observation of the gross bone specimen, immunohistochemistry, and fluorescent confocal scanning microscopy. Results In vitro, BHA/PAA promoted the adhesion, growth, and calcium nodule formation of MG63 cells, and it had good osteogenesis activity. In vivo, with BHA/PAA material degradation and absorption, the new bone gradually formed, and the bone defect gradually recovered in the experimental group. In the control group, a limited bone formation was found at the bone broken ends, and the bone defect was obviously visible. Conclusion In vitro and in vivo, we confirmed that BHA/PAA was effective in inducing osteogenesis and reconstructing a long segmental bone defect. PMID:26719675

  15. Scintillator material

    DOEpatents

    Anderson, David F.; Kross, Brian J.

    1994-01-01

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

  16. Scintillator material

    DOEpatents

    Anderson, D.F.; Kross, B.J.

    1992-07-28

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

  17. Scintillator material

    DOEpatents

    Anderson, D.F.; Kross, B.J.

    1994-06-07

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

  18. Scintillator material

    DOEpatents

    Anderson, David F.; Kross, Brian J.

    1992-01-01

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

  19. Raw materials.

    PubMed

    Peters, Dietmar

    2007-01-01

    Industrial fermentations need raw materials that fulfill the requirements of the organism (suitable carbon and nitrogen source, minerals and specific nutrients) and that are available in a high quantity and quality. This contribution gives a comprehensive overview, including the new trends and progress of recent years. The use of feedstock based on several raw materials such as sugar, starch, inulin and lignocellulose is discussed. Biomass-based raw materials are by far the most applied feedstocks for fermentation. However, there are also raw materials for fermentations derived from the petrochemical industry. These substrates are especially hydrocarbons, alcohols and carboxylic acids. Some applications are given in this chapter. PMID:17408080

  20. Materials Repurposed

    ERIC Educational Resources Information Center

    White, Orvil L.; Townsend, J. Scott

    2008-01-01

    Few teachers find themselves with the support to purchase all of the materials they ideally need to supply their classrooms. Buying one or two simple, ready-made items can put a serious strain on anyone's budget. However, materials for science in the classroom need not be prefabricated or expensive. By looking at the function and purpose of any…

  1. Energy Materials.

    ERIC Educational Resources Information Center

    Iowa State Dept. of Public Instruction, Des Moines.

    These resource materials, developed for use by teachers in the elementary and secondary schools, are designed to provide the teacher with a bibliography, questions and answeres, and suggested classroom activities all relating to the energy problem. The materials are designed to develop a conservation ethic and greater understanding of our energy…

  2. Packaging Materials

    NASA Astrophysics Data System (ADS)

    Frear, Darrel

    This chapter is a high-level overview of the materials used in an electronic package including: metals used as conductors in the package, ceramics and glasses used as dielectrics or insulators and polymers used as insulators and, in a composite form, as conductors. There is a need for new materials to meet the ever-changing requirements for high-speed digital and radio-frequency (RF) applications. There are different requirements for digital and RF packages that translate into the need for unique materials for each application. The interconnect and dielectric (insulating) requirements are presented for each application and the relevant materials properties and characteristics are discussed. The fundamental materials characteristics are: dielectric constant, dielectric loss, thermal and electric conductivity, resistivity, moisture absorption, glass-transition temperature, strength, time-dependent deformation (creep), and fracture toughness. The materials characteristics and properties are dependant on how they are processed to form the electronic package so the fundamentals of electronic packaging processes are discussed including wirebonding, solder interconnects, flip-chip interconnects, underfill for flip chip and overmolding. The relevant materials properties are given along with requirements (including environmentally friendly Pb-free packages) that require new materials to be developed to meet future electronics needs for both digital and RF applications.

  3. Cermet materials

    DOEpatents

    Kong, Peter C.

    2008-12-23

    A self-cleaning porous cermet material, filter and system utilizing the same may be used in filtering particulate and gaseous pollutants from internal combustion engines having intermetallic and ceramic phases. The porous cermet filter may be made from a transition metal aluminide phase and an alumina phase. Filler materials may be added to increase the porosity or tailor the catalytic properties of the cermet material. Additionally, the cermet material may be reinforced with fibers or screens. The porous filter may also be electrically conductive so that a current may be passed therethrough to heat the filter during use. Further, a heating element may be incorporated into the porous cermet filter during manufacture. This heating element can be coated with a ceramic material to electrically insulate the heating element. An external heating element may also be provided to heat the cermet filter during use.

  4. Composite material

    DOEpatents

    Hutchens, Stacy A.; Woodward, Jonathan; Evans, Barbara R.; O'Neill, Hugh M.

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  5. Insulation Material

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Manufactured by Hitco Materials Division of Armco, Inc. a ceramic fiber insulation material known as Refrasil has been used extensively as a heat-absorbing ablative reinforcement for such space systems as rocket motor nozzles, combustion chambers, and re-entry shields. Refrasil fibers are highly porous and do not melt or vaporize until fibers exceed 3,100 degrees Fahrenheit. Due to these and other properties, Refrasil has found utility in a number of industrial high temperature applications where glass, asbestos and other materials fail. Hitco used this insulation to assist Richardson Co., Inc. in the manufacturing of hard rubber and plastic molded battery cases.

  6. Contrast Materials

    MedlinePlus

    ... or other reactions to contrast materials are rare, radiology departments are well-equipped to deal with them. ... is given. However, both the American College of Radiology (ACR) and the European Society of Urogenital Radiology ...

  7. Complex Materials

    SciTech Connect

    Cooper, Valentino

    2014-04-17

    Valentino Cooper uses some of the world's most powerful computing to understand how materials work at subatomic levels, studying breakthroughs such as piezoelectrics, which convert mechanical stress to electrical energy.

  8. Complex Materials

    ScienceCinema

    Cooper, Valentino

    2014-05-23

    Valentino Cooper uses some of the world's most powerful computing to understand how materials work at subatomic levels, studying breakthroughs such as piezoelectrics, which convert mechanical stress to electrical energy.

  9. Hazardous materials

    MedlinePlus

    ... should be in a room with good airflow Work Safely If you find a spill, treat it like ... Hazard communication; Material Safety Data Sheet; MSDS References Occupational Safety and Health Administration. Healthcare. Available at: www.osha. ...

  10. CURRICULUM MATERIALS.

    ERIC Educational Resources Information Center

    New Jersey State Dept. of Education, Trenton.

    MATERIALS ARE LISTED BY 36 TOPICS ARRANGED IN ALPHABETICAL ORDER. TOPICS INCLUDE APPRENTICE TRAINING, BAKING, DRAFTING, ENGLISH, GLASSBLOWING, HOME ECONOMICS, INDUSTRIAL CHEMISTRY, MACHINE SHOP, NEEDLE TRADES, REFRIGERATION, AND UPHOLSTERY. PRICES ARE GIVEN FOR EACH ITEM. (EL)

  11. Materials considerations

    NASA Technical Reports Server (NTRS)

    Gray, H. R.; Nelson, H. G.; Johnson, R. E.; Mcpherson, B.; Howard, F. S.; Swisher, J. H.

    1975-01-01

    Materials problems are examined that may be encountered within a hydrogen energy system. Emphasis is placed on hydrogen embrittlement, corrosion, oxidation, and erosion. Other factors discussed include: degradation of mechanical properties of structural alloys, system reliability, and maintenance costs.

  12. Propulsion materials

    SciTech Connect

    Wall, Edward J.; Sullivan, Rogelio A.; Gibbs, Jerry L.

    2008-01-01

    The Department of Energy’s (DOE’s) Office of Vehicle Technologies (OVT) is pleased to introduce the FY 2007 Annual Progress Report for the Propulsion Materials Research and Development Program. Together with DOE national laboratories and in partnership with private industry and universities across the United States, the program continues to engage in research and development (R&D) that provides enabling materials technology for fuel-efficient and environmentally friendly commercial and passenger vehicles.

  13. Parachute materials

    SciTech Connect

    Peterson, C.W.; Johnson, D.W.

    1987-06-01

    The purpose of this paper is to present guidelines for the use of Kevlar and nylon materials in modern parachute systems. Nylon has been used in parachutes for many years, so this discussion will place emphasis upon Kevlar material properties and their application to parachute design and construction. Kevlar-29 is an aramid fiber manufactured by DuPont and is being used on parachute systems requiring high strength-to-weight ratios or sustained strength at high temperatures. Tests of parachutes using Kevlar webbing, braided cords, ribbons, and thread have demonstrated that these Kevlar materials can be used successfully in ribbon parachutes with no detrimental effects on performance. A few changes must be made in the design of a ribbon parachute to accommodate Kevlar's high modulus. Examples of parachutes that use Kevlar suspension lines, radials, ribbons, reefing lines, bridles, and skirt bands are presented to show that they are much lighter and more resistant to aerodynamic heating than all-nylon parachutes. Nylon continues to be an important material for high-performance parachute systems, however. New nylon weaves have resulted in lighter weight, stronger ribbon materials with excellent sewability characteristics.

  14. Materials Overview

    NASA Technical Reports Server (NTRS)

    Draper, Robert

    2001-01-01

    The Materials and Structures for High Performance project has made excellent progress in the development of advanced high-temperature materials and computational materials science tools to enable high-performance, hgh-efficiency, and environmentally compatible propulsion systems. Ceramic matrix composite (CMC) systems with 2700 O F temperature capability are initially being developed for low NO, combustor liners and turbine vanes. The feasibility of pushing CMC technologies to 3000 O F through revolutionary concepts is also being pursued. Achieving fuel savings of 8 to 15 percent requires higher turbine inlet temperatures as well as reductions in engine weight. An advanced disk alloy has been evaluated for application in future engines. Advanced thermal barrier coatings (TBC s) will enable 3200 O F turbine rotor inlet temperature capability. Advanced alloy development and the development of computational tools for the design of these future alloys will further enable attainment of these goals. Innovative lightweight materials, and structural and nozzle aerodynamic concepts are also being developed to reduce the weight of engine static structures to contribute toward overall fuel savings. Rig tests will demonstrate long-term durability of CMC linersand vanes and advanced turbine airfoil alloy systems, as well as fabricability of components with the highest payoff potential using the lightweight materials and structures concepts being developed.

  15. Hardfacing material

    DOEpatents

    Branagan, Daniel J.

    2012-01-17

    A method of producing a hard metallic material by forming a mixture containing at least 55% iron and at least one of boron, carbon, silicon and phosphorus. The mixture is formed into an alloy and cooled to form a metallic material having a hardness of greater than about 9.2 GPa. The invention includes a method of forming a wire by combining a metal strip and a powder. The metal strip and the powder are rolled to form a wire containing at least 55% iron and from two to seven additional elements including at least one of C, Si and B. The invention also includes a method of forming a hardened surface on a substrate by processing a solid mass to form a powder, applying the powder to a surface to form a layer containing metallic glass, and converting the glass to a crystalline material having a nanocrystalline grain size.

  16. Layered materials

    NASA Astrophysics Data System (ADS)

    Johnson, David; Clarke, Simon; Wiley, John; Koumoto, Kunihito

    2014-06-01

    Layered compounds, materials with a large anisotropy to their bonding, electrical and/or magnetic properties, have been important in the development of solid state chemistry, physics and engineering applications. Layered materials were the initial test bed where chemists developed intercalation chemistry that evolved into the field of topochemical reactions where researchers are able to perform sequential steps to arrive at kinetically stable products that cannot be directly prepared by other approaches. Physicists have used layered compounds to discover and understand novel phenomena made more apparent through reduced dimensionality. The discovery of charge and spin density waves and more recently the remarkable discovery in condensed matter physics of the two-dimensional topological insulating state were discovered in two-dimensional materials. The understanding developed in two-dimensional materials enabled subsequent extension of these and other phenomena into three-dimensional materials. Layered compounds have also been used in many technologies as engineers and scientists used their unique properties to solve challenging technical problems (low temperature ion conduction for batteries, easy shear planes for lubrication in vacuum, edge decorated catalyst sites for catalytic removal of sulfur from oil, etc). The articles that are published in this issue provide an excellent overview of the spectrum of activities that are being pursued, as well as an introduction to some of the most established achievements in the field. Clusters of papers discussing thermoelectric properties, electronic structure and transport properties, growth of single two-dimensional layers, intercalation and more extensive topochemical reactions and the interleaving of two structures to form new materials highlight the breadth of current research in this area. These papers will hopefully serve as a useful guideline for the interested reader to different important aspects in this field and

  17. Squishy Materials

    NASA Astrophysics Data System (ADS)

    Habdas, Piotr; Weeks, Eric R.; Lynn, David G.

    2006-05-01

    Most people do not realize that many substances they use in the kitchen and the bathroom are not simple liquids or solids. Everyone is familiar with three states of matter: solids, liquids, and gases. However, creams, shampoo, toothpaste, and ketchup all have properties of both liquids and solids. This paper describes demonstrations and laboratory exercises1 that show intriguing properties of squishy substances, defined as materials that are not unambiguously solid, liquid, or gas. Unlike some areas of physics, the concepts behind squishy materials are understandable even by beginning students. Squishy physics can be used to show physics questions arising from everyday life and to convey the excitement of current research.

  18. Creating Materials.

    ERIC Educational Resources Information Center

    Yin, Mary

    1990-01-01

    Describes practical materials that relate to places within the English-as-a-Second-Language learner's own community, such as the supermarket, local fast food restaurants, pharmacy, and library. Each literacy booklet contains approximately 35 pages of activities that can be used as classroom handouts. (LB)

  19. Materials compatibility.

    SciTech Connect

    Somerday, Brian P.

    2010-04-01

    Objectives are to enable development and implementation of codes and standards for H{sub 2} containment components: (1) Evaluate data on mechanical properties of materials in H{sub 2} gas - Technical Reference on Hydrogen Compatibility of Materials; (2) Generate new benchmark data on high-priority materials - Pressure vessel steels, stainless steels; and (3) Establish procedures for reliable materials testing - Sustained-load cracking, fatigue crack propagation. Summary of this presentation are: (1) Completed measurement of cracking thresholds (K{sub TH}) for Ni-Cr-Mo pressure vessel steels in high-pressure H{sub 2} gas - K{sub TH} measurements required in ASME Article KD-10 (2) Crack arrest test methods appear to yield non-conservative results compared to crack initiation test methods - (a) Proposal to insert crack initiation test methods in Article KD-10 will be presented to ASME Project Team on Hydrogen Tanks, and (b) Crack initiation methods require test apparatus designed for dynamic loading of specimens in H{sub 2} gas; and (3) Demonstrated ability to measure fatigue crack growth of pressure vessel steels in high-pressure H{sub 2} gas - (a) Fatigue crack growth data in H{sub 2} required in ASME Article KD-10, and (b) Test apparatus is one of few in U.S. or abroad for measuring fatigue crack growth in >100 MPa H{sub 2} gas.

  20. Classification Materials.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Center for Law and Education.

    This packet contains complaints, memoranda, exhibits, orders, regulations, and stipulations in court cases dealing with expulsion or suspension of students from school or assignment of students to selected tracks. The report presents material from cases in which students were excluded from school or classes based on retardation, race, "medical…

  1. BIOBASED MATERIALS

    EPA Science Inventory

    Biobased materials refer to products that mainly consist of a substance (or substances) derived from living matter (biomass) and either occur naturally or are synthesized, or it may refer to products made by processes that use biomass. Following a strict definition, many common m...

  2. Materials Science

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Materials Science Program is structured so that NASA s headquarters is responsible for the program content and selection, through the Enterprise Scientist, and MSFC provides for implementation of ground and flight programs with a Discipline Scientist and Discipline Manager. The Discipline Working Group of eminent scientists from outside of NASA acts in an advisory capacity and writes the Discipline Document from which the NRA content is derived. The program is reviewed approximately every three years by groups such as the Committee on Microgravity Research, the National Materials Advisory Board, and the OBPR Maximization and Prioritization (ReMaP) Task Force. The flight program has had as many as twenty-six principal investigators (PIs) in flight or flight definition stage, with the numbers of PIs in the future dependent on the results of the ReMaP Task Force and internal reviews. Each project has a NASA-appointed Project Scientist, considered a half-time job, who assists the PI in understanding and preparing for internal reviews such as the Science Concept Review and Requirements Definition Review. The Project Scientist also insures that the PI gets the maximum science support from MSFC, represents the PI to the MSFC community, and collaborates with the Project Manager to insure the project is well-supported and remains vital. Currently available flight equipment includes the Materials Science Research Rack (MSRR-1) and Microgravity Science Glovebox. Ground based projects fall into one or more of several categories. Intellectual Underpinning of Flight Program projects include theoretical studies backed by modeling and computer simulations; bring to maturity new research, often by young researchers, and may include preliminary short duration low gravity experiments in the KC-135 aircraft or drop tube; enable characterization of data sets from previous flights; and provide thermophysical property determinations to aid PIs. Radiation Shielding and preliminary In

  3. Prosthesis Material

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In this photograph, Sandra Rossi user her NASA-developed prosthesis for the first time. Derived from foam insulation technology used to protect the Space Shuttle External Tank from excessive heat, FAB/CAD, a subsidiary of the Harshberger Prosthetic and Orthotic Center, utilized the technology to replace the heavy, fragile plaster they used to produce master molds for prosthetics. The new material was lighter, cheaper and easier to manufacture than plaster, resulting in lower costs to the customer.

  4. Prosthesis Material

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In this photograph, James Carden uses a NASA-developed prosthesis to moved planks around his home. Derived from foam insulation technology used to protect the Space Shuttle External Tank from excessive heat, FAB/CAD, a subsidiary of the Harshberger Prosthetic and Orthotic Center, utilized the technology to replace the heavy, fragile plaster they used to produce master molds for prosthetics. The new material was lighter, cheaper and easier to manufacture than plaster, resulting in lower costs to the customer.

  5. Prosthesis Material

    NASA Technical Reports Server (NTRS)

    2004-01-01

    In this photograph, Amputee Amie Bradly uses a NASA-developed prosthesis to paint her fingernails. Derived from foam insulation technology used to protect the Space Shuttle External Tank from excessive heat, FAB/CAD, a subsidiary of the Harshberger Prosthetic and Orthotic Center, utilized the technology to replace the heavy, fragile plaster they used to produce master molds for prosthetics. The new material was lighter, cheaper and easier to manufacture than plaster, resulting in lower costs to the customer.

  6. Fullerene materials

    SciTech Connect

    Malhotra, R.; Ruoff, R.S.; Lorents, D.C.

    1995-04-01

    Fullerenes are all-carbon cage molecules. The most celebrated fullerene is the soccer-ball shaped C{sub 60}, which is composed of twenty hexagons and twelve pentagons. Because its structure is reminiscent of the geodesic domes of architect R. Buckminster Fuller, C{sub 60} is called buckminsterfullerene, and all the materials in the family are designated fullerenes. Huffman and Kraetschmer`s discovery unleashed activity around the world as scientists explored production methods, properties, and potential uses of fullerenes. Within a short period, methods for their production in electric arcs, plasmas, and flames were discovered, and several companies began selling fullerenes to the research market. What is remarkable is that in all these methods, carbon atoms assemble themselves into cage structures. The capability for self-assembly points to some inherent stability of these structures that allows their formation. The unusual structure naturally leads to unusual properties. Among them are ready solubility in solvents and a relatively high vapor pressure for a pure carbon material. The young fullerene field has already produced a surprising array of structures for the development of carbon-base materials having completely new and different properties from any that were previously possible.

  7. FOREWORD: Materials metrology Materials metrology

    NASA Astrophysics Data System (ADS)

    Bennett, Seton; Valdés, Joaquin

    2010-04-01

    It seems that so much of modern life is defined by the materials we use. From aircraft to architecture, from cars to communications, from microelectronics to medicine, the development of new materials and the innovative application of existing ones have underpinned the technological advances that have transformed the way we live, work and play. Recognizing the need for a sound technical basis for drafting codes of practice and specifications for advanced materials, the governments of countries of the Economic Summit (G7) and the European Commission signed a Memorandum of Understanding in 1982 to establish the Versailles Project on Advanced Materials and Standards (VAMAS). This project supports international trade by enabling scientific collaboration as a precursor to the drafting of standards. The VAMAS participants recognized the importance of agreeing a reliable, universally accepted basis for the traceability of the measurements on which standards depend for their preparation and implementation. Seeing the need to involve the wider metrology community, VAMAS approached the Comité International des Poids et Mesures (CIPM). Following discussions with NMI Directors and a workshop at the BIPM in February 2005, the CIPM decided to establish an ad hoc Working Group on the metrology applicable to the measurement of material properties. The Working Group presented its conclusions to the CIPM in October 2007 and published its final report in 2008, leading to the signature of a Memorandum of Understanding between VAMAS and the BIPM. This MoU recognizes the work that is already going on in VAMAS as well as in the Consultative Committees of the CIPM and establishes a framework for an ongoing dialogue on issues of materials metrology. The question of what is meant by traceability in the metrology of the properties of materials is particularly vexed when the measurement results depend on a specified procedure. In these cases, confidence in results requires not only traceable

  8. Construction material

    DOEpatents

    Wagh, Arun S.; Antink, Allison L.

    2008-07-22

    A structural material of a polystyrene base and the reaction product of the polystyrene base and a solid phosphate ceramic is applied as a slurry which includes one or more of a metal oxide or a metal hydroxide with a source of phosphate to produce a phosphate ceramic and a poly (acrylic acid or acrylate) or combinations or salts thereof and polystyrene or MgO applied to the polystyrene base and allowed to cure so that the dried aqueous slurry chemically bonds to the polystyrene base. A method is also disclosed of applying the slurry to the polystyrene base.

  9. Casting materials

    DOEpatents

    Chaudhry, Anil R.; Dzugan, Robert; Harrington, Richard M.; Neece, Faurice D.; Singh, Nipendra P.

    2011-06-14

    A foam material comprises a liquid polymer and a liquid isocyanate which is mixed to make a solution that is poured, injected or otherwise deposited into a corresponding mold. A reaction from the mixture of the liquid polymer and liquid isocyanate inside the mold forms a thermally collapsible foam structure having a shape that corresponds to the inside surface configuration of the mold and a skin that is continuous and unbroken. Once the reaction is complete, the foam pattern is removed from the mold and may be used as a pattern in any number of conventional casting processes.

  10. Alloy materials

    DOEpatents

    Hans Thieme, Cornelis Leo; Thompson, Elliott D.; Fritzemeier, Leslie G.; Cameron, Robert D.; Siegal, Edward J.

    2002-01-01

    An alloy that contains at least two metals and can be used as a substrate for a superconductor is disclosed. The alloy can contain an oxide former. The alloy can have a biaxial or cube texture. The substrate can be used in a multilayer superconductor, which can further include one or more buffer layers disposed between the substrate and the superconductor material. The alloys can be made a by process that involves first rolling the alloy then annealing the alloy. A relatively large volume percentage of the alloy can be formed of grains having a biaxial or cube texture.

  11. Photovoltaic Materials

    SciTech Connect

    Duty, C.; Angelini, J.; Armstrong, B.; Bennett, C.; Evans, B.; Jellison, G. E.; Joshi, P.; List, F.; Paranthaman, P.; Parish, C.; Wereszczak, A.

    2012-10-15

    The goal of the current project was to help make the US solar industry a world leader in the manufacture of thin film photovoltaics. The overall approach was to leverage ORNL’s unique characterization and processing technologies to gain a better understanding of the fundamental challenges for solar cell processing and apply that knowledge to targeted projects with industry members. ORNL has the capabilities in place and the expertise required to understand how basic material properties including defects, impurities, and grain boundaries affect the solar cell performance. ORNL also has unique processing capabilities to optimize the manufacturing process for fabrication of high efficiency and low cost solar cells. ORNL recently established the Center for Advanced Thin-film Systems (CATS), which contains a suite of optical and electrical characterization equipment specifically focused on solar cell research. Under this project, ORNL made these facilities available to industrial partners who were interested in pursuing collaborative research toward the improvement of their product or manufacturing process. Four specific projects were pursued with industrial partners: Global Solar Energy is a solar industry leader in full scale production manufacturing highly-efficient Copper Indium Gallium diSelenide (CIGS) thin film solar material, cells and products. ORNL worked with GSE to develop a scalable, non-vacuum, solution technique to deposit amorphous or nanocrystalline conducting barrier layers on untextured stainless steel substrates for fabricating high efficiency flexible CIGS PV. Ferro Corporation’s Electronic, Color and Glass Materials (“ECGM”) business unit is currently the world’s largest supplier of metallic contact materials in the crystalline solar cell marketplace. Ferro’s ECGM business unit has been the world's leading supplier of thick film metal pastes to the crystalline silicon PV industry for more than 30 years, and has had operational cells and

  12. PREFACE: Superconducting materials Superconducting materials

    NASA Astrophysics Data System (ADS)

    Charfi Kaddour, Samia; Singleton, John; Haddad, Sonia

    2011-11-01

    The discovery of superconductivity in 1911 was a great milestone in condensed matter physics. This discovery has resulted in an enormous amount of research activity. Collaboration among chemists and physicists, as well as experimentalists and theoreticians has given rise to very rich physics with significant potential applications ranging from electric power transmission to quantum information. Several superconducting materials have been synthesized. Crucial progress was made in 1987 with the discovery of high temperature superconductivity in copper-based compounds (cuprates) which have revealed new fascinating properties. Innovative theoretical tools have been developed to understand the striking features of cuprates which have remained for three decades the 'blue-eyed boy' for researchers in superconductor physics. The history of superconducting materials has been notably marked by the discovery of other compounds, particularly organic superconductors which despite their low critical temperature continue to attract great interest regarding their exotic properties. Last but not least, the recent observation of superconductivity in iron-based materials (pnictides) has renewed hope in reaching room temperature superconductivity. However, despite intense worldwide studies, several features related to this phenomenon remain unveiled. One of the fundamental key questions is the mechanism by which superconductivity takes place. Superconductors continue to hide their 'secret garden'. The new trends in the physics of superconductivity have been one of the two basic topics of the International Conference on Conducting Materials (ICoCoM2010) held in Sousse,Tunisia on 3-7 November 2010 and organized by the Tunisian Physical Society. The conference was a nice opportunity to bring together participants from multidisciplinary domains in the physics of superconductivity. This special section contains papers submitted by participants who gave an oral contribution at ICoCoM2010

  13. Revolutionizing orthopaedic biomaterials: The potential of biodegradable and bioresorbable magnesium-based materials for functional tissue engineering

    PubMed Central

    Farraro, Kathryn F.; Kim, Kwang E.; Woo, Savio L-Y.; Flowers, Jonquil R.; McCullough, Matthew B.

    2014-01-01

    In recent years, there has been a surge of interest in magnesium (Mg) and its alloys as biomaterials for orthopaedic applications, as they possess desirable mechanical properties, good biocompatibility, and biodegradability. Also shown to be osteoinductive, Mg-based materials could be particularly advantageous in functional tissue engineering to improve healing and serve as scaffolds for delivery of drugs, cells, and cytokines. In this paper, we will present two examples of Mg-based orthopaedic devices: an interference screw to accelerate ACL graft healing and a ring to aid in the healing of an injured ACL. In vitro tests using a robotic/UFS testing system showed that both devices could restore function of the goat stifle joint. Under a 67-N anterior tibial load, both the ACL graft fixed with the Mg-based interference screw and the Mg-based ring-repaired ACL could restore anterior tibial translation (ATT) to within 2 mm and 5 mm, respectively, of the intact joint at 301, 601, and 901 of flexion. In-situ forces in the replacement graft and Mg-based ring-repaired ACL were also similar to those of the intact ACL. Further, early in vivo data using the Mg-based interference screw showed that after 12 weeks, it was non-toxic and the joint stability and graft function reached similar levels as published data. Following these positive results, we will move forward in incorporating bioactive molecules and ECM bioscaffolds to these Mg-based biomaterials to test their potential for functional tissue engineering of musculoskeletal and other tissues. PMID:24373510

  14. Superconducting materials

    SciTech Connect

    Ruvalds, J.

    1992-01-01

    Our research on high temperatures superconductors has produced novel insights for the normal state properties of copper oxides that have been discovered in the last few years. Advances in materials preparation have produced singly crystal samples, and sophisticated surface cleavage techniques have unveiled truly metallic behavior in many respects. Thus, the recent confirmation of a Fermi surface in several cuprate superconductors by photoemission spectroscopy has aroused interest in experimental features which heretofore were in apparent contrast to the expectations for a conventional Fermi Liquid. Our group has discovered that nested'' nearly parallel sections of the electron orbits yields an anomalous response which influences the electrical resistivity, optical reflectance, Raman spectrum, and neutron scattering cross section. Our analysis has provided an explanation for seemingly disparate experimental features of high temperature superconductors using consistent values for the electron-electron coupling and the plasma frequency. Our results include the following properties of high temperature superconductors: Nested Fermi Liquid Response in High Temperature Superconductors, Optical Reflectivity and Electron Energy Loss Data, Raman Spectra, Neutron Scattering Cross Section and Scaling, and Prospects for New Superconductors.

  15. Digestive Diseases Materials

    MedlinePlus

    ... NIDDK Health Information NIDDK Home NIDDK Image Library Digestive Disease, Nutrition, and Weight-control Materials Healthy eating, ... Materials Statistics Tip Sheets Catalog Home | Diabetes Materials | Digestive Diseases Materials | Kidney and Urologic Diseases Materials Online ...

  16. Critical Materials Institute

    SciTech Connect

    Alex King

    2013-01-09

    Ames Laboratory Director Alex King talks about the goals of the Critical Materials Institute in diversifying the supply of critical materials, developing substitute materials, developing tools and techniques for recycling critical materials, and forecasting materials needs to avoid future shortages.

  17. Critical Materials Institute

    ScienceCinema

    Alex King

    2013-06-05

    Ames Laboratory Director Alex King talks about the goals of the Critical Materials Institute in diversifying the supply of critical materials, developing substitute materials, developing tools and techniques for recycling critical materials, and forecasting materials needs to avoid future shortages.

  18. Gas storage materials, including hydrogen storage materials

    SciTech Connect

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2014-11-25

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material, such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  19. Gas storage materials, including hydrogen storage materials

    DOEpatents

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2013-02-19

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  20. Geopolymer resin materials, geopolymer materials, and materials produced thereby

    DOEpatents

    Seo, Dong-Kyun; Medpelli, Dinesh; Ladd, Danielle; Mesgar, Milad

    2016-03-29

    A product formed from a first material including a geopolymer resin material, a geopolymer resin, or a combination thereof by contacting the first material with a fluid and removing at least some of the fluid to yield a product. The first material may be formed by heating and/or aging an initial geopolymer resin material to yield the first material before contacting the first material with the fluid. In some cases, contacting the first material with the fluid breaks up or disintegrates the first material (e.g., in response to contact with the fluid and in the absence of external mechanical stress), thereby forming particles having an external dimension in a range between 1 nm and 2 cm.

  1. Materials Project: A Materials Genome Approach

    DOE Data Explorer

    Ceder, Gerbrand [MIT; Persson, Kristin [LBNL

    Technological innovation - faster computers, more efficient solar cells, more compact energy storage - is often enabled by materials advances. Yet, it takes an average of 18 years to move new materials discoveries from lab to market. This is largely because materials designers operate with very little information and must painstakingly tweak new materials in the lab. Computational materials science is now powerful enough that it can predict many properties of materials before those materials are ever synthesized in the lab. By scaling materials computations over supercomputing clusters, this project has computed some properties of over 80,000 materials and screened 25,000 of these for Li-ion batteries. The computations predicted several new battery materials which were made and tested in the lab and are now being patented. By computing properties of all known materials, the Materials Project aims to remove guesswork from materials design in a variety of applications. Experimental research can be targeted to the most promising compounds from computational data sets. Researchers will be able to data-mine scientific trends in materials properties. By providing materials researchers with the information they need to design better, the Materials Project aims to accelerate innovation in materials research.[copied from http://materialsproject.org/about] You will be asked to register to be granted free, full access.

  2. Nuclear materials in Japan

    NASA Astrophysics Data System (ADS)

    2015-03-01

    The incident at Fukushima Daiichi brought materials in the nuclear industry into the spotlight. Nature Materials talks to Tatsuo Shikama, Director of the International Research Centre for Nuclear Materials, Institute for Materials Research, Tohoku University, about the current situation.

  3. Transportation of hazardous materials

    SciTech Connect

    Not Available

    1986-07-01

    This report discusses the following: data and information systems for hazardous-materials; containers for hazardous-materials transportation; hazardous-materials transportation regulation; and training for hazardous-materials transportation enforcement and emergency response.

  4. Composite material dosimeters

    DOEpatents

    Miller, Steven D.

    1996-01-01

    The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

  5. Method for forming materials

    DOEpatents

    Tolle, Charles R.; Clark, Denis E.; Smartt, Herschel B.; Miller, Karen S.

    2009-10-06

    A material-forming tool and a method for forming a material are described including a shank portion; a shoulder portion that releasably engages the shank portion; a pin that releasably engages the shoulder portion, wherein the pin defines a passageway; and a source of a material coupled in material flowing relation relative to the pin and wherein the material-forming tool is utilized in methodology that includes providing a first material; providing a second material, and placing the second material into contact with the first material; and locally plastically deforming the first material with the material-forming tool so as mix the first material and second material together to form a resulting material having characteristics different from the respective first and second materials.

  6. Transporting particulate material

    DOEpatents

    Aldred, Derek Leslie; Rader, Jeffrey A.; Saunders, Timothy W.

    2011-08-30

    A material transporting system comprises a material transporting apparatus (100) including a material transporting apparatus hopper structure (200, 202), which comprises at least one rotary transporting apparatus; a stationary hub structure (900) constraining and assisting the at least one rotary transporting apparatus; an outlet duct configuration (700) configured to permit material to exit therefrom and comprising at least one diverging portion (702, 702'); an outlet abutment configuration (800) configured to direct material to the outlet duct configuration; an outlet valve assembly from the material transporting system venting the material transporting system; and a moving wall configuration in the material transporting apparatus capable of assisting the material transporting apparatus in transporting material in the material transporting system. Material can be moved from the material transporting apparatus hopper structure to the outlet duct configuration through the at least one rotary transporting apparatus, the outlet abutment configuration, and the outlet valve assembly.

  7. Nanocrystalline ceramic materials

    DOEpatents

    Siegel, Richard W.; Nieman, G. William; Weertman, Julia R.

    1994-01-01

    A method for preparing a treated nanocrystalline metallic material. The method of preparation includes providing a starting nanocrystalline metallic material with a grain size less than about 35 nm, compacting the starting nanocrystalline metallic material in an inert atmosphere and annealing the compacted metallic material at a temperature less than about one-half the melting point of the metallic material.

  8. Introductory Materials Laboratory.

    ERIC Educational Resources Information Center

    Ritter, John E., Jr.

    Described is an introductory materials science laboratory program which emphasizes crystal structure both on the atomistic and microscopic scale and the dependence of materials properties on structure. The content of this program is classified into four major areas: (1) materials science, (2) mechanical behavior of materials, (3) materials testing…

  9. Curriculum Materials 1973.

    ERIC Educational Resources Information Center

    Association for Supervision and Curriculum Development, Washington, DC.

    This publication catalogs the materials received by the Curriculum Materials Committee for the Association for Supervision and Curriculum Development's 1973 annual conference. The materials referenced offer a broad representation of current curriculum materials issued throughout the nation. Materials are referenced under general curriculum…

  10. Material efficiency: providing material services with less material production

    PubMed Central

    Allwood, Julian M.; Ashby, Michael F.; Gutowski, Timothy G.; Worrell, Ernst

    2013-01-01

    Material efficiency, as discussed in this Meeting Issue, entails the pursuit of the technical strategies, business models, consumer preferences and policy instruments that would lead to a substantial reduction in the production of high-volume energy-intensive materials required to deliver human well-being. This paper, which introduces a Discussion Meeting Issue on the topic of material efficiency, aims to give an overview of current thinking on the topic, spanning environmental, engineering, economics, sociology and policy issues. The motivations for material efficiency include reducing energy demand, reducing the emissions and other environmental impacts of industry, and increasing national resource security. There are many technical strategies that might bring it about, and these could mainly be implemented today if preferred by customers or producers. However, current economic structures favour the substitution of material for labour, and consumer preferences for material consumption appear to continue even beyond the point at which increased consumption provides any increase in well-being. Therefore, policy will be required to stimulate material efficiency. A theoretically ideal policy measure, such as a carbon price, would internalize the externality of emissions associated with material production, and thus motivate change directly. However, implementation of such a measure has proved elusive, and instead the adjustment of existing government purchasing policies or existing regulations— for instance to do with building design, planning or vehicle standards—is likely to have a more immediate effect. PMID:23359746

  11. Material efficiency: providing material services with less material production.

    PubMed

    Allwood, Julian M; Ashby, Michael F; Gutowski, Timothy G; Worrell, Ernst

    2013-03-13

    Material efficiency, as discussed in this Meeting Issue, entails the pursuit of the technical strategies, business models, consumer preferences and policy instruments that would lead to a substantial reduction in the production of high-volume energy-intensive materials required to deliver human well-being. This paper, which introduces a Discussion Meeting Issue on the topic of material efficiency, aims to give an overview of current thinking on the topic, spanning environmental, engineering, economics, sociology and policy issues. The motivations for material efficiency include reducing energy demand, reducing the emissions and other environmental impacts of industry, and increasing national resource security. There are many technical strategies that might bring it about, and these could mainly be implemented today if preferred by customers or producers. However, current economic structures favour the substitution of material for labour, and consumer preferences for material consumption appear to continue even beyond the point at which increased consumption provides any increase in well-being. Therefore, policy will be required to stimulate material efficiency. A theoretically ideal policy measure, such as a carbon price, would internalize the externality of emissions associated with material production, and thus motivate change directly. However, implementation of such a measure has proved elusive, and instead the adjustment of existing government purchasing policies or existing regulations-- for instance to do with building design, planning or vehicle standards--is likely to have a more immediate effect. PMID:23359746

  12. Structural materials and components

    NASA Technical Reports Server (NTRS)

    Gagliani, John (Inventor); Lee, Raymond (Inventor)

    1982-01-01

    High density structural (blocking) materials composed of a polyimide filled with glass microballoons and methods for making such materials. Structural components such as panels which have integral edgings and/or other parts made of the high density materials.

  13. Thermoelectric materials and devices

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon (Inventor); Choi, Sang H. (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor); Talcott, Noel A. (Inventor)

    2011-01-01

    New thermoelectric materials comprise highly [111]-oriented twinned group IV alloys on the basal plane of trigonal substrates, which exhibit a high thermoelectric figure of merit and good material performance, and devices made with these materials.

  14. Use of demineralized bone as an osteoinductive orbital enucleation implant in the rabbit.

    PubMed

    Sires, B S; Geggel, H S; Heffernan, J T; Crane, R D; Holds, J B

    1993-06-01

    Implanted allogeneic demineralized bone particles (DBP) may be transformed into endochondral bone by inductive or conductive new bone formation. Using a rabbit model, enucleation or evisceration was performed, and DBP was implanted into the socket. Histology confirmed endochondral bone formation in both groups. A morphologic difference existed between enucleation and evisceration: compact bone was produced following evisceration, and cancellous bony spheres were formed following enucleation. Serial quantitative computed tomography (qCT) was performed to monitor mineral density and proved to be an ideal technique to monitor bone mineralization noninvasively in the postoperative orbit. Bone mineral density (BMD, mg/ml) increased approximately 300% in DBP implanted orbits when compared to controls at 6 weeks. The ideal mass/volume ratio of DBP to socket volume was 400 mg/ml. The rapidly formed bone is well vascularized and creates a stable integrated orbital implant, following enucleation and evisceration surgery. DBP implantation into the central orbit results in inductive bone formation with interesting potential in socket and orbit reconstruction. PMID:8323902

  15. Osteoinductive activity of insulin-functionalized cell culture surfaces obtained using diazonium chemistry

    NASA Astrophysics Data System (ADS)

    Mikulska, Anna; Filipowska, Joanna; Osyczka, Anna; Nowakowska, Maria; Szczubiałka, Krzysztof

    2014-12-01

    Polymeric surfaces suitable for cell culture (DR/Pec) were constructed from diazoresin (DR) and pectin (Pec) in a form of ultrathin films using the layer-by-layer (LbL) technique. The surfaces were functionalized with insulin using diazonium chemistry. Such functionalized surfaces were used to culture human mesenchymal stem cells (hMSCs) to assess their suitability for bone tissue engineering and regeneration. The activity of insulin immobilized on the surfaces (DR/Pec/Ins) was compared to that of insulin dissolved in the culture medium. Human MSC grown on insulin-immobilized DR/Pec surfaces displayed increased proliferation and higher osteogenic activity. The latter was determined by means of alkaline phosphatase (ALP) activity, which increases at early stages of osteoblasts differentiation. Insulin dissolved in the culture medium did not stimulate cell proliferation and its osteogenic activity was significantly lower. Addition of recombinant human bone morphogenetic protein 2 (rhBMP-2) to the culture medium further increased ALP activity in hMSCs indicating additive osteogenic action of immobilized insulin and rhBMP-2

  16. Influence of irradiation on the osteoinductive potential of demineralized bone matrix.

    PubMed

    Wientroub, S; Reddi, A H

    1988-04-01

    Samples of demineralized bone matrix (DBM) were exposed to graduated doses of radiation (1-15 Megarad) (Mrad) utilizing a linear accelerator and then implanted into the thoracic region of Long-Evans rats. Subcutaneous implantation of DBM into allogenic rats induces endochondral bone. In response to matrix implantation, a cascade of events ensues; mesenchymal cell proliferation on day 3 postimplantation, chondrogenesis on day 7, calcification of the cartilagenous matrix and chondrolysis on day 9, and osteogenesis on day 11 resulting in formation of an ossicle containing active hemopoietic tissue. Bone formation was assessed by measuring alkaline phosphatase activity, the rate of mineralization was determined by measuring 45Ca incorporation to bone mineral, and 40Ca content measured the extent of mineralization; acid phosphatase activity was used as a parameter for bone resorption. The dose of radiation (2.5 Mrad) currently used by bone banks for sterilization of bone tissue did not destroy the bone induction properties of DBM. Furthermore, radiation of 3-5 Mrad even enhanced bone induction, insofar as it produced more bone at the same interval of time than was obtained from unirradiated control samples. None of the radiation doses used in these experiments abolished bone induction, although the response induced by matrix irradiated with doses higher than 5 Mrad was delayed. PMID:3135091

  17. Osteoinductive activity of insulin-functionalized cell culture surfaces obtained using diazonium chemistry

    PubMed Central

    Mikulska, Anna; Filipowska, Joanna; Osyczka, Anna M.; Nowakowska, Maria; Szczubiałka, Krzysztof

    2015-01-01

    Polymeric surfaces suitable for cell culture (DR/Pec) were constructed from diazoresin (DR) and pectin (Pec) in a form of ultrathin films using the layer-by-layer (LbL) technique. The surfaces were functionalized with insulin using diazonium chemistry. Such functionalized surfaces were used to culture human mesenchymal stem cells (hMSCs) to assess their suitability for bone tissue engineering and regeneration. The activity of insulin immobilized on the surfaces (DR/Pec/Ins) was compared to that of insulin dissolved in the culture medium. Human MSC grown on insulin-immobilized DR/Pec surfaces displayed increased proliferation and higher osteogenic activity. The latter was determined by means of alkaline phosphatase (ALP) activity, which increases at early stages of osteoblasts differentiation. Insulin dissolved in the culture medium did not stimulate cell proliferation and its osteogenic activity was significantly lower. Addition of recombinant human bone morphogenetic protein 2 (rhBMP-2) to the culture medium further increased ALP activity in hMSCs indicating additive osteogenic action of immobilized insulin and rhBMP-2. PMID:25629028

  18. Osteoinductive effect of bone bank allografts on human osteoblasts in culture.

    PubMed

    de la Piedra, Concepción; Vicario, Carlos; de Acuña, Lucrecia Rodríguez; García-Moreno, Carmen; Traba, Maria Luisa; Arlandis, Santiago; Marco, Fernando; López-Durán, Luis

    2008-02-01

    Incorporation of a human bone allograft requires osteoclast activity and growth of recipient osteoblasts. The aim of this work was to study the effects produced by autoclavated and -80 degrees C frozen bone allografts on osteoblast proliferation and synthesis of interleukin 6 (IL6), activator of bone resorption, aminoterminal propeptide of procollagen I (PINP), marker of bone matrix formation, and osteoprotegerin (OPG), inhibitor of osteoclast activity and differentiation. Allografts were obtained from human femoral heads. Human osteoblasts were cultured in the presence (problem group) or in the absence (control group) of allografts during 15 days. Allografts produced a decrease in osteoblast proliferation in the first week of the experiment, and an increase in IL6 mRNA, both at 3 h and 2 days, and an increase in the IL6 released to the culture medium the second day of the experiment. We found a decrease in OPG released to the culture on the 2nd and fourth days. These results suggest an increase in bone resorption and a decrease in bone formation in the first week of the experiment. In the second week, allografts produced an increase in osteoblast proliferation and PINP release to the culture medium, indicating an increase in bone formation; an increase in OPG released to the culture medium, which would indicate a decrease in bone resorption; and a decrease in IL6, indicating a decrease in bone resorption stimulation. These results demonstrate that autoclavated and -80 degrees C frozen bone allografts produce in bone environment changes that regulate their own incorporation to the recipient bone. PMID:17853479

  19. Blue-Violet Laser Modification of Titania Treated Titanium: Antibacterial and Osteo-Inductive Effects

    PubMed Central

    Kawano, Takanori; Prananingrum, Widyasri; Ishida, Yuichi; Goto, Takaharu; Naito, Yoshihito; Watanabe, Megumi; Tomotake, Yoritoki; Ichikawa, Tetsuo

    2013-01-01

    Background Many studies on surface modifications of titanium have been performed in an attempt to accelerate osseointegration. Recently, anatase titanium dioxide has been found to act as a photocatalyst that expresses antibiotic properties and exhibits hydrophilicity after ultraviolet exposure. A blue-violet semiconductor laser (BV-LD) has been developed as near-ultraviolet light. The purpose of this study was to investigate the effects of exposure to this BV-LD on surface modifications of titanium with the goal of enhancing osteoconductive and antibacterial properties. Methods The surfaces of pure commercial titanium were polished with #800 waterproof polishing papers and were treated with anatase titania solution. Specimens were exposed using BV-LD (λ = 405 nm) or an ultraviolet light-emitting diode (UV-LED, λ = 365 nm) at 6 mW/cm2 for 3 h. The surface modification was evaluated physically and biologically using the following parameters or tests: surface roughness, surface temperature during exposure, X-ray diffraction (XRD) analysis, contact angle, methylene blue degradation tests, adherence of Porphyromonas gingivalis, osteoblast and fibroblast proliferation, and histological examination after implantation in rats. Results No significant changes were found in the surface roughness or XRD profiles after exposure. BV-LD exposure did not raise the surface temperature of titanium. The contact angle was significantly decreased, and methylene blue was significantly degraded. The number of attached P. gingivalis organisms was significantly reduced after BV-LD exposure compared to that in the no exposure group. New bone was observed around exposed specimens in the histological evaluation, and both the bone-to-specimen contact ratio and the new bone area increased significantly in exposed groups. Conclusions This study suggested that exposure of titanium to BV-LD can enhance the osteoconductivity of the titanium surface and induce antibacterial properties, similar to the properties observed following exposure to UV-LED. PMID:24358355

  20. Ectopic Bone Matrix Mineralization: Unveiling the Osteoinductive Nature of Crab Cuticle

    NASA Astrophysics Data System (ADS)

    Omokanwaye, Tiffany Suella

    Engineered nanomaterials are increasingly used in a variety of industrial processes and consumer products. Numerous studies have reported toxicity of different NPs during the last years. Thus, there are growing concerns about the potential impacts to the health and environment of engineered nanoparticles (NPs). However, some methodological problems complicate the interpretation of nanotoxicity studies. On the one hand, some NPs have shown to interfere with classical toxicity assays based on colorimetric or fluorescent measurements. On the other hand, most NPs tend to aggregate in media used in toxicity tests, which complicates the interpretation of the toxicity results. The first objective of this dissertation was to evaluate a novel impedance-based and label-free real time cell analyzer (RTCA) as a high throughput method for screening the cytotoxicity of nanoparticles and to validate the RTCA results using a conventional cytotoxicity test (MTT). Several inorganic NPs were tested for potential cytotoxicity to human bronchial epithelial cells (16HBE14o-). In general, there was a good correlation in cytotoxicity measurements between the two methods. Moreover, none of the NPs tested showed interference with the impedance measurements performed by the RTCA system. The results demonstrate the potential and validity of the impedance-based RTCA technique to rapidly screen for NP toxicity. The second objective of this dissertation was to assess the toxicity of different inorganic NPs to the eukaryotic cell model Saccharomyces cerevisiae, and to test the influence of NP aggregation state in their toxicity. Nanotoxicity was assessed by monitoring oxygen consumption in batch cultures and by analysis of cell membrane integrity. Mn2O3 NPs showed the highest inhibition of O2 consumption and cell membrane damage, while the other NPs caused low or no toxicity to the yeast. Most NPs showed high tendency to aggregate in the assay medium, so a non-toxic dispersant was used to improve NP stability. In contrast to aggregated CeO2 NPs, dispersed CeO 2 NPs showed toxicity to the yeast. However, dispersant supplementation decreased the inhibition caused by Mn2O3 NPs at low concentrations, which could indicate that dispersant association with the particles may have an impact on the interaction between the NPs and the cells. The proven toxicity of some NPs raises concerns about their environmental fate. Municipal and industrial wastewaters are considered primary sources of NPs to the environment. However, information on the behavior and impact of NPs on wastewater treatment processes is very limited. A third objective of this dissertation was to evaluate the fate and long-term effect of ZnO and CuO NPs during wastewater treatment in high-rate anaerobic bioreactors. Laboratory-scale upflow anaerobic sludge blanket (UASB) reactors were fed with synthetic wastewater containing NPs for extended periods of time (> 90 d). Extensive removal (62-82%) of ZnO and CuO NPs was observed during wastewater treatment in the UASB reactors. Scanning electron microscopy and chemical analysis confirmed that NPs were associated with the anaerobic sludge. While short-term exposure to low levels of ZnO and CuO NPs only caused minor inhibition to methanogenesis, extended exposure to NPs accumulated in the sludge bed led to a gradual and partial inhibitory response in the reactors. The inhibitory effect was also evident in the decline in the acetoclastic methanogenic activity of the biomass.

  1. Nonmetallic materials handbook. Volume 1: Epoxy materials

    NASA Technical Reports Server (NTRS)

    Podlaseck, S. E.

    1979-01-01

    Thermochemical and other properties data is presented for the following types of epoxy materials: adhesives, coatings finishes, inks, electrical insulation, encapsulants, sealants, composite laminates, tapes, and thermal insulators.

  2. Preparation and physical characterization of calcium sulfate cement/silica-based mesoporous material composites for controlled release of BMP-2

    PubMed Central

    Tan, Honglue; Yang, Shengbing; Dai, Pengyi; Li, Wuyin; Yue, Bing

    2015-01-01

    As a commonly used implant material, calcium sulfate cement (CSC), has some shortcomings, including low compressive strength, weak osteoinduction capability, and rapid degradation. In this study, silica-based mesoporous materials such as SBA-15 were synthesized and combined with CSC to prepare CSC/SBA-15 composites. The properties of SBA-15 were characterized by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption–desorption isotherms. SBA-15 was blended into CSC at 0, 5, 10, and 20 wt%, referred to as CSC, CSC-5S (5% mass ratio), CSC-10S (10% mass ratio), and CSC-20S (20% mass ratio), respectively. Fourier-transform infrared spectroscopy and compression tests were used to determine the structure and mechanical properties of the composites, respectively. The formation of hydroxyapatite on composite surfaces was analyzed using scanning electron microscopy and X-ray diffraction after soaking in simulated body fluid. BMP-2 was loaded into the composites by vacuum freeze-drying, and its release characteristics were detected by Bradford protein assay. The in vitro degradation of the CSC/SBA-15 composite was investigated by measuring weight loss. The results showed that the orderly, nanostructured, mesoporous SBA-15 possessed regular pore size and structure. The compressive strength of CSC/SBA-15 increased with the increase in SBA-15 mass ratio, and CSC-20S demonstrated the maximum strength. Compared to CSC, hydroxyapatite that formed on the surfaces of CSC/SBA-15 was uniform and compact. The degradation rate of CSC/SBA-15 decreased with increasing mass ratio of SBA-15. The adsorption of BMP-2 increased and released at a relatively slow rate; the release rate of BMP-2 in CSC-20S was the slowest, and presented characteristics of low doses of release. In vitro experiments demonstrated that the physical properties of pure CSC incorporated with SBA-15 could be improved significantly, which made the CSC/SBA-15 composite more suitable for bone repair

  3. Preparation and physical characterization of calcium sulfate cement/silica-based mesoporous material composites for controlled release of BMP-2.

    PubMed

    Tan, Honglue; Yang, Shengbing; Dai, Pengyi; Li, Wuyin; Yue, Bing

    2015-01-01

    As a commonly used implant material, calcium sulfate cement (CSC), has some shortcomings, including low compressive strength, weak osteoinduction capability, and rapid degradation. In this study, silica-based mesoporous materials such as SBA-15 were synthesized and combined with CSC to prepare CSC/SBA-15 composites. The properties of SBA-15 were characterized by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. SBA-15 was blended into CSC at 0, 5, 10, and 20 wt%, referred to as CSC, CSC-5S (5% mass ratio), CSC-10S (10% mass ratio), and CSC-20S (20% mass ratio), respectively. Fourier-transform infrared spectroscopy and compression tests were used to determine the structure and mechanical properties of the composites, respectively. The formation of hydroxyapatite on composite surfaces was analyzed using scanning electron microscopy and X-ray diffraction after soaking in simulated body fluid. BMP-2 was loaded into the composites by vacuum freeze-drying, and its release characteristics were detected by Bradford protein assay. The in vitro degradation of the CSC/SBA-15 composite was investigated by measuring weight loss. The results showed that the orderly, nanostructured, mesoporous SBA-15 possessed regular pore size and structure. The compressive strength of CSC/SBA-15 increased with the increase in SBA-15 mass ratio, and CSC-20S demonstrated the maximum strength. Compared to CSC, hydroxyapatite that formed on the surfaces of CSC/SBA-15 was uniform and compact. The degradation rate of CSC/SBA-15 decreased with increasing mass ratio of SBA-15. The adsorption of BMP-2 increased and released at a relatively slow rate; the release rate of BMP-2 in CSC-20S was the slowest, and presented characteristics of low doses of release. In vitro experiments demonstrated that the physical properties of pure CSC incorporated with SBA-15 could be improved significantly, which made the CSC/SBA-15 composite more suitable for bone repair

  4. Coated ceramic breeder materials

    DOEpatents

    Tam, Shiu-Wing; Johnson, Carl E.

    1987-04-07

    A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

  5. Biological materials by design.

    PubMed

    Qin, Zhao; Dimas, Leon; Adler, David; Bratzel, Graham; Buehler, Markus J

    2014-02-19

    In this topical review we discuss recent advances in the use of physical insight into the way biological materials function, to design novel engineered materials 'from scratch', or from the level of fundamental building blocks upwards and by using computational multiscale methods that link chemistry to material function. We present studies that connect advances in multiscale hierarchical material structuring with material synthesis and testing, review case studies of wood and other biological materials, and illustrate how engineered fiber composites and bulk materials are designed, modeled, and then synthesized and tested experimentally. The integration of experiment and simulation in multiscale design opens new avenues to explore the physics of materials from a fundamental perspective, and using complementary strengths from models and empirical techniques. Recent developments in this field illustrate a new paradigm by which complex material functionality is achieved through hierarchical structuring in spite of simple material constituents. PMID:24451343

  6. Materials Analysis and Modeling of Underfill Materials.

    SciTech Connect

    Wyatt, Nicholas B; Chambers, Robert S.

    2015-08-01

    The thermal-mechanical properties of three potential underfill candidate materials for PBGA applications are characterized and reported. Two of the materials are a formulations developed at Sandia for underfill applications while the third is a commercial product that utilizes a snap-cure chemistry to drastically reduce cure time. Viscoelastic models were calibrated and fit using the property data collected for one of the Sandia formulated materials. Along with the thermal-mechanical analyses performed, a series of simple bi-material strip tests were conducted to comparatively analyze the relative effects of cure and thermal shrinkage amongst the materials under consideration. Finally, current knowledge gaps as well as questions arising from the present study are identified and a path forward presented.

  7. Puncture detecting barrier materials

    DOEpatents

    Hermes, R.E.; Ramsey, D.R.; Stampfer, J.F.; Macdonald, J.M.

    1998-03-31

    A method and apparatus for continuous real-time monitoring of the integrity of protective barrier materials, particularly protective barriers against toxic, radioactive and biologically hazardous materials has been developed. Conductivity, resistivity or capacitance between conductive layers in the multilayer protective materials is measured by using leads connected to electrically conductive layers in the protective barrier material. The measured conductivity, resistivity or capacitance significantly changes upon a physical breach of the protective barrier material. 4 figs.

  8. Materials technology for SIRTF

    NASA Technical Reports Server (NTRS)

    Coulter, D.; Dolgin, B.; Rainen, R.; O'Donnell, T.

    1991-01-01

    A number of studies on materials technologies for the Space Infrared Telescope Facility (SIRTF) intended to enhance SIRTF mission performance are reviewed. Particular attention is given to dewar support straps, dewar structural materials, infrared black coatings, optical mirror materials, cryogenic properties data base, contamination control, and thermal control materials/coatings. It is noted that the alternative to baseline materials offer potential for substantial improvements in reliability, weight, and lifetime.

  9. Nanocrystalline ceramic materials

    DOEpatents

    Siegel, R.W.; Nieman, G.W.; Weertman, J.R.

    1994-06-14

    A method is disclosed for preparing a treated nanocrystalline metallic material. The method of preparation includes providing a starting nanocrystalline metallic material with a grain size less than about 35 nm, compacting the starting nanocrystalline metallic material in an inert atmosphere and annealing the compacted metallic material at a temperature less than about one-half the melting point of the metallic material. 19 figs.

  10. Puncture detecting barrier materials

    DOEpatents

    Hermes, Robert E.; Ramsey, David R.; Stampfer, Joseph F.; Macdonald, John M.

    1998-01-01

    A method and apparatus for continuous real-time monitoring of the integrity of protective barrier materials, particularly protective barriers against toxic, radioactive and biologically hazardous materials has been developed. Conductivity, resistivity or capacitance between conductive layers in the multilayer protective materials is measured by using leads connected to electrically conductive layers in the protective barrier material. The measured conductivity, resistivity or capacitance significantly changes upon a physical breach of the protective barrier material.

  11. Enhanced magnetocaloric effect material

    DOEpatents

    Lewis, Laura J. H.

    2006-07-18

    A magnetocaloric effect heterostructure having a core layer of a magnetostructural material with a giant magnetocaloric effect having a magnetic transition temperature equal to or greater than 150 K, and a constricting material layer coated on at least one surface of the magnetocaloric material core layer. The constricting material layer may enhance the magnetocaloric effect by restriction of volume changes of the core layer during application of a magnetic field to the heterostructure. A magnetocaloric effect heterostructure powder comprising a plurality of core particles of a magnetostructural material with a giant magnetocaloric effect having a magnetic transition temperature equal to or greater than 150 K, wherein each of the core particles is encapsulated within a coating of a constricting material is also disclosed. A method for enhancing the magnetocaloric effect within a giant magnetocaloric material including the step of coating a surface of the magnetocaloric material with a constricting material is disclosed.

  12. Joining of dissimilar materials

    DOEpatents

    Tucker, Michael C; Lau, Grace Y; Jacobson, Craig P

    2012-10-16

    A method of joining dissimilar materials having different ductility, involves two principal steps: Decoration of the more ductile material's surface with particles of a less ductile material to produce a composite; and, sinter-bonding the composite produced to a joining member of a less ductile material. The joining method is suitable for joining dissimilar materials that are chemically inert towards each other (e.g., metal and ceramic), while resulting in a strong bond with a sharp interface between the two materials. The joining materials may differ greatly in form or particle size. The method is applicable to various types of materials including ceramic, metal, glass, glass-ceramic, polymer, cermet, semiconductor, etc., and the materials can be in various geometrical forms, such as powders, fibers, or bulk bodies (foil, wire, plate, etc.). Composites and devices with a decorated/sintered interface are also provided.

  13. Martian surface materials

    NASA Technical Reports Server (NTRS)

    Moore, H. J.

    1991-01-01

    A semiquantitative appreciation for the physical properties of the Mars surface materials and their global variations can be gained from the Viking Lander and remote sensing observations. Analyses of Lander data yields estimates of the mechanical properties of the soil-like surface materials and best guess estimates can be made for the remote sensing signatures of the soil-like materials at the landing sites. Results show that significant thickness of powderlike surface materials with physical properties similar to drift material are present on Mars and probably pervasive in the Tharsis region. It also appears likely that soil-like materials similar to crusty to cloddy material are typical for Mars, and that soil-like material similar to blocky material are common on Mars.

  14. Orbital foamed material extruder

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S. (Inventor)

    2009-01-01

    This invention is a process for producing foamed material in space comprising the steps of: rotating the material to simulate the force of gravity; heating the rotating material until it is molten; extruding the rotating, molten material; injecting gas into the extruded, rotating, molten material to produce molten foamed material; allowing the molten foamed material to cool to below melting temperature to produce the foamed material. The surface of the extruded foam may be heated to above melting temperature and allowed to cool to below melting temperature. The extruded foam may also be cut to predetermined length. The starting material may be metal or glass. Heating may be accomplished by electrical heating elements or by solar heating.

  15. Materials Test Branch

    NASA Technical Reports Server (NTRS)

    Gordon, Gail

    2012-01-01

    The Materials Test Branch resides at Marshall Space Flight Center's Materials and Processing laboratory and has a long history of supporting NASA programs from Mercury to the recently retired Space Shuttle. The Materials Test Branch supports its customers by supplying materials testing expertise in a wide range of applications. The Materials Test Branch is divided into three Teams, The Chemistry Team, The Tribology Team and the Mechanical Test Team. Our mission and goal is to provide world-class engineering excellence in materials testing with a special emphasis on customer service.

  16. Databases for materials selection

    SciTech Connect

    1996-06-01

    The Cambridge Materials Selector (CMS2.0) materials database was developed by the Engineering Dept. at Cambridge University in the United Kingdom. This database makes it possible to select a material for a specific application from essentially all classes of materials. Genera, Predict, and Socrates software programs from CLI International, Houston, Texas, automate materials selection and corrosion problem-solving tasks. They are said to significantly reduce the time necessary to select a suitable material and/or to assess a corrosion problem and reach cost-effective solutions. This article describes both databases and tells how to use them.

  17. Comprehensive Nuclear Materials

    SciTech Connect

    Konings, Dr. Rudy J. M.; Allen, Todd R.; Stoller, Roger E; Yamanaka, Prof. Shinsuke

    2012-01-01

    This book encompasses a rich seam of current information on the vast and multidisciplinary field of nuclear materials employed in fission and prototype fusion systems. Discussion includes both historical and contemporary international research in nuclear materials, from Actinides to Zirconium alloys, from the worlds leading scientists and engineers. Synthesizes pertinent current science to support the selection, assessment, validation and engineering of materials in extreme nuclear environments. The work discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels, cladding, moderator and control materials, structural, functional, and waste materials.

  18. Nondestructive material characterization

    DOEpatents

    Deason, Vance A.; Johnson, John A.; Telschow, Kenneth L.

    1991-01-01

    A method and apparatus for nondestructive material characterization, such as identification of material flaws or defects, material thickness or uniformity and material properties such as acoustic velocity. The apparatus comprises a pulsed laser used to excite a piezoelectric (PZ) transducer, which sends acoustic waves through an acoustic coupling medium to the test material. The acoustic wave is absorbed and thereafter reflected by the test material, whereupon it impinges on the PZ transducer. The PZ transducer converts the acoustic wave to electrical impulses, which are conveyed to a monitor.

  19. Materials science and engineering

    SciTech Connect

    Lesuer, D.R.

    1997-02-01

    During FY-96, work within the Materials Science and Engineering Thrust Area was focused on material modeling. Our motivation for this work is to develop the capability to study the structural response of materials as well as material processing. These capabilities have been applied to a broad range of problems, in support of many programs at Lawrence Livermore National Laboratory. These studies are described in (1) Strength and Fracture Toughness of Material Interfaces; (2) Damage Evolution in Fiber Composite Materials; (3) Flashlamp Envelope Optical Properties and Failure Analysis; (4) Synthesis and Processing of Nanocrystalline Hydroxyapatite; and (5) Room Temperature Creep Compliance of Bulk Kel-E.

  20. [Elastomeric impression materials].

    PubMed

    Anagnostopoulos, T; Tsokas, K

    1990-01-01

    A review of the literature on elastomeric impression materials, is presented in this paper. The article mentions the composition and the most important properties of the elastomeric impression materials used in dental practice. The clinical significance of these materials, physical and mechanical properties are also emphasized. In addition some new elastomeric impression materials with improved properties and a new (experimental) light-cured impression material, are mentioned. Another part of this article is the biocompatibility of these materials. In the end the great significance of handling is outlined. PMID:2130039

  1. Materials for breeding blankets

    SciTech Connect

    Mattas, R.F.; Billone, M.C.

    1995-09-01

    There are several candidate concepts for tritium breeding blankets that make use of a number of special materials. These materials can be classified as Primary Blanket Materials, which have the greatest influence in determining the overall design and performance, and Secondary Blanket Materials, which have key functions in the operation of the blanket but are less important in establishing the overall design and performance. The issues associated with the blanket materials are specified and several examples of materials performance are given. Critical data needs are identified.

  2. Materials All Around Us

    NASA Technical Reports Server (NTRS)

    Jacobs, James A.

    1996-01-01

    The purpose of this journal exercise is to determine the properties of the materials in the environment around us, and to relate these properties to the materials systems for which they are used. Students will develop a strong rationale for gaining knowledge of engineering materials. The journal entries will serve as a starting point classroom discussion. Along with the journal, students are required to bring samples to class of 'found' materials and products composed of materials systems. Students are encouraged to be materials observers.

  3. Insulated waterproof drainage material

    SciTech Connect

    Tarko, P.L.

    1988-03-15

    An insulative waterproof drainage material is described comprising: a sheet of rigid material having hills and valleys therein to define a core having opposed surfaces; permeable fabric material attached to one of the opposed surfaces; and a layer of thermally insulative material on the other of the opposed surfaces. The insulative material has first surface covering the hills and valleys and a second surface oppositely disposed from the first surface defining an outer surface. The outer surface is spaced a preselected distance D from the hills of the core. The pre-selected distance D define an insulative material thickness corresponding to a pre-selected thermal value.

  4. Materials science and engineering

    SciTech Connect

    Lesuer, D R

    1998-01-01

    During FY-97, work within the Materials Science and Engineering thrust area was focused on material modeling. Their motivation for this work is to develop the capability to study the structural response of materials as well as materials processing. These capabilities have been applied to a broad range of problems, which support many programs at Lawrence Livermore National Laboratory. Recent examples of structural response problems studied include material fracture (such as interface failure), damage in laser optics, the response of weapons components (such as high explosives) and the failure of composite materials. For materials processing, typical problems studied include metal forming, laser processing, casting, and heat treating. To improve our ability to model material behavior, much of the work involves developing new material models and failure models, as well as applying the codes to new problems. Most investigations involve experimental studies to gather basic information on material response and to validate codes or material models. Projects are inherently multi-disciplinary, involving several investigators with expertise in materials and mechanics. The thrust area studies for FY-97 are described in the following three articles: (1) Evolution of Anisotropic Yield Behavior; (2) Modeling of She Localization in Materials; and (3) Modeling of Casting Microstructures and Defects.

  5. EC Transmission Line Materials

    SciTech Connect

    Bigelow, Tim S

    2012-05-01

    The purpose of this document is to identify materials acceptable for use in the US ITER Project Office (USIPO)-supplied components for the ITER Electron cyclotron Heating and Current Drive (ECH&CD) transmission lines (TL), PBS-52. The source of material property information for design analysis shall be either the applicable structural code or the ITER Material Properties Handbook. In the case of conflict, the ITER Material Properties Handbook shall take precedence. Materials selection, and use, shall follow the guidelines established in the Materials Assessment Report (MAR). Materials exposed to vacuum shall conform to the ITER Vacuum Handbook. [Ref. 2] Commercial materials shall conform to the applicable standard (e.g., ASTM, JIS, DIN) for the definition of their grade, physical, chemical and electrical properties and related testing. All materials for which a suitable certification from the supplier is not available shall be tested to determine the relevant properties, as part of the procurement. A complete traceability of all the materials including welding materials shall be provided. Halogenated materials (example: insulating materials) shall be forbidden in areas served by the detritiation systems. Exceptions must be approved by the Tritium System and Safety Section Responsible Officers.

  6. Ultrasonic material property determinations

    NASA Technical Reports Server (NTRS)

    Serabian, S.

    1986-01-01

    The use and potential offered by ultrasonic velocity and attenuation measurements to determine and/or monitor material properties is explored. The basis for such unique measurements along with examples of materials from a variety of industries are presented.

  7. Structural materials and components

    NASA Technical Reports Server (NTRS)

    Gagliani, John (Inventor); Lee, Raymond (Inventor)

    1982-01-01

    High density structural (blocking) materials composed of a polyimide filled with glass microballoons. Structural components such as panels which have integral edgings and/or other parts made of the high density materials.

  8. Improvisation: Teaching Materials.

    ERIC Educational Resources Information Center

    Kuzmich, John A., Jr.

    1980-01-01

    The past, present and future of music improvisation is discussed. Resources for piano, guitar, elementary general music materials, and electronic music materials are included, along with addresses of publishers. The emphasis is on jazz. (KC)

  9. Bibliography of AV Materials.

    ERIC Educational Resources Information Center

    Friedstein, Harriet, Ed.

    1981-01-01

    Lists commercially available audiovisual materials by subject area. Includes title, producer (addresses given), catalog number, format (film, filmstrip, cassette, slides), and prices. Subject areas include: elements; equilibrium; gases; laboratory techniques and experiments; general chemistry; introductory materials (including mathematics); and…

  10. Bridged graphite oxide materials

    NASA Technical Reports Server (NTRS)

    Herrera-Alonso, Margarita (Inventor); McAllister, Michael J. (Inventor); Aksay, Ilhan A. (Inventor); Prud'homme, Robert K. (Inventor)

    2010-01-01

    Bridged graphite oxide material comprising graphite sheets bridged by at least one diamine bridging group. The bridged graphite oxide material may be incorporated in polymer composites or used in adsorption media.

  11. Silicone azide fireproof material

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Finely powdered titanium oxide was added to silicone azide as the sintering agent to produce a nonflammable material. Mixing proportions, physical properties, and chemical composition of the fireproofing material are included.

  12. Materials processing in space

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The feasibility and possible advantages of processing materials in a nongravitational field are considered. Areas of investigation include biomedical applications, the processing of inorganic materials, and flight programs and funding.

  13. Renewable smart materials

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Chan; Mun, Seongcheol; Ko, Hyun-U.; Zhai, Lindong; Kafy, Abdullahil; Kim, Jaehwan

    2016-07-01

    The use of renewable materials is essential in future technologies to harmonize with our living environment. Renewable materials can maintain our resources from the environment so as to overcome degradation of natural environmental services and diminished productivity. This paper reviews recent advancement of renewable materials for smart material applications, including wood, cellulose, chitin, lignin, and their sensors, actuators and energy storage applications. To further improve functionality of renewable materials, hybrid composites of inorganic functional materials are introduced by incorporating carbon nanotubes, titanium dioxide and tin oxide conducting polymers and ionic liquids. Since renewable materials have many advantages of biocompatible, sustainable, biodegradable, high mechanical strength and versatile modification behaviors, more research efforts need to be focused on the development of renewable smart materials.

  14. Materials modelling in London

    NASA Astrophysics Data System (ADS)

    Ciudad, David

    2016-04-01

    Angelos Michaelides, Professor in Theoretical Chemistry at University College London (UCL) and co-director of the Thomas Young Centre (TYC), explains to Nature Materials the challenges in materials modelling and the objectives of the TYC.

  15. Supplements to Textbook Materials.

    ERIC Educational Resources Information Center

    Holmes, Ken

    1994-01-01

    Describes the many kinds of materials that English teachers can draw upon to enrich and expand students' experiences with literature. Outlines ancillary materials used to supplement the study of William Shakespeare's "Julius Caesar." (HB)

  16. Cutter for Woven Materials

    NASA Technical Reports Server (NTRS)

    Hammons, J. M.; Keir, A. R.

    1983-01-01

    Simple tool makes accurate square cuts through strips of woven or felted materials, such as high temperature aramid fabric. Pressing handle on Guillotine Cutter forces razor blade through strip of material in slot, cutting strip off squarely.

  17. Impact tolerant material

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S. (Inventor)

    1990-01-01

    A material is protected from acoustic shock waves generated by impacting projectiles by means of a backing. The backing has an acoustic impedance that efficiently couples the acoustic energy out of the material.

  18. Materials Curriculum Development.

    ERIC Educational Resources Information Center

    Petty, Evan R.

    1987-01-01

    Presents perspectives on the aims and content of materials science courses and materials engineering courses. Outlines a proposed curriculum for a four-year degree course in engineering and identifies technical and social skills necessary for engineers. (ML)

  19. Structural materials and components

    NASA Technical Reports Server (NTRS)

    Gagliani, John (Inventor); Lee, Raymond (Inventor)

    1983-01-01

    High density structural (blocking) materials composed of a polyimide filled with glass microballoons. Structural components such as panels which have integral edgings and/or other parts made of the high density materials.

  20. Lightweight Materials & Structures

    NASA Video Gallery

    The Lightweight Materials and Structures (LMS) project will mature high-payoff structures and materials technologies that have direct application to NASA’s future space exploration needs.One of the...

  1. Nanostructured composite reinforced material

    DOEpatents

    Seals, Roland D.; Ripley, Edward B.; Ludtka, Gerard M.

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  2. Materials and structures

    NASA Technical Reports Server (NTRS)

    Venneri, Samuel L.

    1988-01-01

    Information on materials and structures for use in space is given in viewgraph form. Information is given on the Materials and Structures Division of NASA's Office of Aeronautics and Space Technology. The Division's space research and development budget is given. Further information is given on space materials and structures, space environmental effects, radiation effects, high temperature materials research, metal matrix composites, SiC fiber reinforced titanium alloys, structural dynamics, and control of flexible structures.

  3. Smart materials and structures

    NASA Technical Reports Server (NTRS)

    Rogowski, Robert S.; Heyman, Joseph S.

    1993-01-01

    Embedded optical fibers allow not only the cure-monitoring and in-service lifetime measurements of composite materials, but the NDE of material damage and degradation with aging. The capabilities of such damage-detection systems have been extended to allow the quantitative determination of 2D strain in materials by several different methods, including the interferometric and the numerical. It remains to be seen, what effect the embedded fibers have on the strength of the 'smart' materials created through their incorporation.

  4. Materials Genome Initiative Element

    NASA Technical Reports Server (NTRS)

    Vickers, John

    2015-01-01

    NASA is committed to developing new materials and manufacturing methods that can enable new missions with ever increasing mission demands. Typically, the development and certification of new materials and manufacturing methods in the aerospace industry has required more than 20 years of development time with a costly testing and certification program. To reduce the cost and time to mature these emerging technologies, NASA is developing computational materials tools to improve understanding of the material and guide the certification process.

  5. Electronics materials research

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The electronic materials and is aimed at the establishment of quantitative relationships underlying crystal growth parameters, materials properties, electronic characteristics and device applications. The overall program evolves about the following main thrust areas: (1) crystal growth novel approaches to engineering of semiconductor materials; (2) investigation of materials properties and electronic characteristics on a macro and microscale; (3) surface properties and surface interactions with the bulk and ambients; (4) electronic properties controlling device applications and device performance.

  6. Advanced Materials Technology

    NASA Technical Reports Server (NTRS)

    Blankenship, C. P. (Compiler); Teichman, L. A. (Compiler)

    1982-01-01

    Composites, polymer science, metallic materials (aluminum, titanium, and superalloys), materials processing technology, materials durability in the aerospace environment, ceramics, fatigue and fracture mechanics, tribology, and nondestructive evaluation (NDE) are discussed. Research and development activities are introduced to the nonaerospace industry. In order to provide a convenient means to help transfer aerospace technology to the commercial mainstream in a systematic manner.

  7. Fusion reactor materials

    SciTech Connect

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  8. Materials for Space Exploration

    NASA Technical Reports Server (NTRS)

    Robertson, Luke B.; Williams, Martha

    2010-01-01

    Topics include a lab overview, testing and processing equipment, hemochromic hydrogen sensors, antimicrobial materials, wire system materials, CNT ink formulations, CNT ink dust screens, CNT ink printed circuitry, cryogenic materials development, fire and polymers, the importance of lighting, electric lighting systems, LED for plant growth, and carbon nanotube fiber filaments.

  9. Advanced neutron absorber materials

    DOEpatents

    Branagan, Daniel J.; Smolik, Galen R.

    2000-01-01

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  10. Paramagnetic and Diamagnetic Materials

    ERIC Educational Resources Information Center

    Thompson, Frank

    2011-01-01

    Paramagnetic and diamagnetic materials are now generally known as the "Cinderella" materials of the magnetic world. However, susceptibility measurements made on these materials in the past have revealed many details about the molecular bonding and the atomic structure of the so-called "transition" elements. Indeed, the magnetic moment of neodymium…

  11. Curriculum Materials Examination System.

    ERIC Educational Resources Information Center

    Bond, David J.

    This document is a guideline for selection and evaluation of social studies curriculum materials developed by the Marin Social Studies Project. Questions are presented which will help in the examination of materials so that specific strengths and weaknesses in the materials can be determined. Consideration is given to the objectives and rationale…

  12. Creating Quality Media Materials.

    ERIC Educational Resources Information Center

    Hortin, John A.; Bailey, Gerald D.

    1982-01-01

    Innovation, imagination, and student creativity are key ingredients in creating quality media materials for the small school. Student-produced media materials, slides without a camera, personalized slide programs and copy work, self-made task cards, self-made overhead transparencies, graphic materials, and utilization of the mass media are some of…

  13. Nulcear materials production: Primer

    SciTech Connect

    Not Available

    1988-09-01

    The US Department of Energy's (DOE's) Office of Nuclear Materials Production (NMP) is responsible for managing the production and recovery of nuclear materials for national defense. NMP oversees the production of radioactive materials for government, commercial, industrial, and medical applications. This Primer is a general introduction to NMP's major activities.

  14. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-01-01

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young's modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  15. Hierarchical cellular materials

    SciTech Connect

    Gibson, L.J.

    1991-12-31

    In this paper a method for estimating the contributions of both the composite and the cellular microstructures to the overall material properties and the mechanical efficiency of natural cellular solids will be described. The method will be demonstrated by focusing on the Young`s modulus; similar techniques can be used for other material properties. The results suggest efficient microstructures for engineered cellular materials.

  16. Evaluating Multiethnic Materials.

    ERIC Educational Resources Information Center

    Garcia, Jesus

    The problem of identifying good ethnic studies materials is a result of the large amount of materials produced in the 1960s and of the currently renewed interest in ethnic studies. Four types of materials are available to elementary classroom teachers: ethnic information, single-ethnic approaches, minority or European-ethnic approaches, and…

  17. Survival Learning Materials.

    ERIC Educational Resources Information Center

    Wilson, Robert M.; Barnes, Marcia M.

    This booklet is designed to provide some starter ideas for teachers to use in developing their own packet of learning materials. The procedures suggested and the examples included are literally starters. "Introduction to Survival Learning Materials" presents some procedures to help teachers get started in developing materials. "Following…

  18. Energy Education Materials Bibliography.

    ERIC Educational Resources Information Center

    Minnesota State Energy Agency, St. Paul.

    This is an annotated bibliography of selected energy education materials. The materials included in this document are indexed according to grade level and according to whether they are background materials or classroom activities. Each of the 100 items listed were evaluated and included into either the "A" list or the "B" list. The "A" list…

  19. Bibliography of Citizenship Materials

    ERIC Educational Resources Information Center

    CASAS - Comprehensive Adult Student Assessment Systems (NJ1), 2008

    2008-01-01

    The 2008 CASAS "Bibliography of Citizenship Materials" lists available instructional resources for citizenship education. It focuses on materials appropriate for preparing people for the naturalization process and the standardized citizenship examination. Resources include textbooks, audio materials, software and Videos/DVDs. The bibliography also…

  20. [Refugee Materials Center Bibliography].

    ERIC Educational Resources Information Center

    Department of Education, Kansas City, MO. Regional Office 7.

    The citations in this bibliography include textbooks, other instructional materials, and resource materials that can be used in teaching refugees in the United States. The title entries are grouped in series consisting of: (1) textbooks, workbooks, and other instuctional materials on teaching English to non-English speakers; (2) curricular and…

  1. Safer Aviation Materials Tested

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    2001-01-01

    A series of thermally stable polymer samples were tested. These materials are called low heat release materials and are designed for aircraft interior decorative materials. The materials are designed to give off a minimum amount of noxious gases when heated, which increases the possibility that people can escape from a burning aircraft. New cabin materials have suitably low heat release so that fire does not spread, toxic chemicals are not given off, and the fire-emergency escape time for crew and passengers is lengthened. These low heat-release materials have a variety of advantages and applications: interiors for ground-based facilities, interiors of space vehicles, and many commercial fire-protection environments. A microscale combustion calorimeter at the Federal Aviation Administration's (FAA) Technical Center tested NASA Langley Research Center materials samples. The calorimeter is shown. A sharp, quantitative, and reproducible heat-release-rate peak is obtained in the microscale heat-release-rate test. The newly tested NASA materials significantly reduced the heat release capacity and total heat release. The thermal stability and flammability behavior of the samples was very good. The new materials demonstrated a factor of 4 reduction in total heat release over ULTEM (a currently used material). This information is provided in the following barchart. In other tests, the materials showed greater than a factor 9 reduction in heat-release capacity over ULTEM. The newly tested materials were developed for low dielectric constant, low color, and good solubility. A scale up of the material samples is needed to determine the repeatability of the performance in larger samples. Larger panels composed of the best candidate materials will be tested in a larger scale FAA Technical Center fire facility. The NASA Glenn Research Center, Langley (Jeff Hinkley), and the FAA Technical Center (Richard Lyon) cooperatively tested these materials for the Accident Mitigation

  2. Advances in dental materials.

    PubMed

    Vaderhobli, Ram M

    2011-07-01

    The use of materials to rehabilitate tooth structures is constantly changing. Over the past decade, newer material processing techniques and technologies have significantly improved the dependability and predictability of dental material for clinicians. The greatest obstacle, however, is in choosing the right combination for continued success. Finding predictable approaches for successful restorative procedures has been the goal of clinical and material scientists. This article provides a broad perspective on the advances made in various classes of dental restorative materials in terms of their functionality with respect to pit and fissure sealants, glass ionomers, and dental composites. PMID:21726695

  3. Self-healing materials.

    PubMed

    Hager, Martin D; Greil, Peter; Leyens, Christoph; van der Zwaag, Sybrand; Schubert, Ulrich S

    2010-12-14

    Self-healing materials are able to partially or completely heal damage inflicted on them, e.g., crack formation; it is anticipated that the original functionality can be restored. This article covers the design and generic principles of self-healing materials through a wide range of different material classes including metals, ceramics, concrete, and polymers. Recent key developments and future challenges in the field of self-healing materials are summarised, and generic, fundamental material-independent principles and mechanism are discussed and evaluated. PMID:20839257

  4. Thermal Protection Materials Development

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna; Cox, Michael

    1998-01-01

    The main portion of this contract year was spent on the development of materials for high temperature applications. In particular, thermal protection materials were constantly tested and evaluated for thermal shock resistance, high-temperature dimensional stability, and tolerance to hostile environmental effects. The analytical laboratory at the Thermal Protection Materials Branch (TPMB), NASA-Ames played an integral part in the process of materials development of high temperature aerospace applications. The materials development focused mainly on the determination of physical and chemical characteristics of specimens from the various research programs.

  5. Tailored Porous Materials

    SciTech Connect

    BARTON,THOMAS J.; BULL,LUCY M.; KLEMPERER,WALTER G.; LOY,DOUGLAS A.; MCENANEY,BRIAN; MISONO,MAKOTO; MONSON,PETER A.; PEZ,GUIDO; SCHERER,GEORGE W.; VARTULI,JAMES C.; YAGHI,OMAR M.

    1999-11-09

    Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol-gel derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

  6. Femtosecond Laser Materials Processing

    SciTech Connect

    Banks, P.S.; Stuart, B.C.; Komashko, A.M.; Feit, M.D.; Rubenchik, A.M.; Perry, M.D.

    2000-03-06

    The use of femtosecond lasers allows materials processing of practically any material with extremely high precision and minimal collateral damage. Advantages over conventional laser machining (using pulses longer than a few tens of picoseconds) are realized by depositing the laser energy into the electrons of the material on a time scale short compared to the transfer time of this energy to the bulk of the material, resulting in increased ablation efficiency and negligible shock or thermal stress. The improvement in the morphology by using femtosecond pulses rather than nanosecond pulses has been studied in numerous materials from biologic materials to dielectrics to metals. During the drilling process, we have observed the onset of small channels which drill faster than the surrounding material.

  7. Materials processing in space

    NASA Technical Reports Server (NTRS)

    Waldron, R. D.; Criswell, D. R.

    1982-01-01

    Processing-refining of raw materials from extraterrestrial sources is detailed for a space materials handling facility. The discussion is constrained to those steps necessary to separate desired components from raw or altered input ores, semi-purified feedstocks, or process scrap and convert the material into elements, alloys, and consumables. The materials are regarded as originating from dead satellites and boosters, lunar materials, and asteroids. Strong attention will be given to recycling reagent substances to avoid the necessity of transporting replacements. It is assumed that since no aqueous processes exist on the moon, the distribution of minerals will be homogeneous. The processing-refining scenario will include hydrochemical, pyrochemical, electrochemical, and physical techniques selected for the output mass rate/unit plant mass ratio. Flow charts of the various materials processing operations which could be performed with lunar materials are provided, noting the necessity of delivering several alloying elements from the earth due to scarcities on the moon.

  8. Dealloying and Dealloyed Materials

    NASA Astrophysics Data System (ADS)

    McCue, Ian; Benn, Ellen; Gaskey, Bernard; Erlebacher, Jonah

    2016-07-01

    A successful working model for nanoporosity evolution during dealloying was introduced 15 years ago. Since that time, the field has rapidly expanded, with research groups from across the world studying dealloying and dealloyed materials. Dealloying has grown into a rich field, with some groups focusing on fundamentals and mechanisms of dealloying, other groups creating new porous metals and alloys, and even more groups studying their properties. Dealloying was originally considered only in the context of corrosion, but now it is considered a facile self-organization technique to fabricate high-surface-area, bicontinuous nanoporous materials. Owing to their high interfacial area and the versatility of metallic materials, nanoporous metals have found application in catalysis, sensing, actuation, electrolytic and ultracapacitor materials, high-temperature templates/scaffolds, battery anodes, and radiation damage–tolerant materials. In this review, we discuss the fundamental materials principles underlying the formation of dealloyed materials and then look at two major applications: catalysis and nanomechanics.

  9. Engineering living functional materials.

    PubMed

    Chen, Allen Y; Zhong, Chao; Lu, Timothy K

    2015-01-16

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered 'living functional materials' and 'living materials synthesis platforms' that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater. 13, 515-523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis-materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID:25592034

  10. Uranium reference materials

    SciTech Connect

    Donivan, S.; Chessmore, R.

    1987-07-01

    The Technical Measurements Center has prepared uranium mill tailings reference materials for use by remedial action contractors and cognizant federal and state agencies. Four materials were prepared with varying concentrations of radionuclides, using three tailings materials and a river-bottom soil diluent. All materials were ground, dried, and blended thoroughly to ensure homogeneity. The analyses on which the recommended values for nuclides in the reference materials are based were performed, using independent methods, by the UNC Geotech (UNC) Chemistry Laboratory, Grand Junction, Colorado, and by C.W. Sill (Sill), Idaho National Engineering Laboratory, Idaho Falls, Idaho. Several statistical tests were performed on the analytical data to characterize the reference materials. Results of these tests reveal that the four reference materials are homogeneous and that no large systematic bias exists between the analytical methods used by Sill and those used by TMC. The average values for radionuclides of the two data sets, representing an unbiased estimate, were used as the recommended values for concentrations of nuclides in the reference materials. The recommended concentrations of radionuclides in the four reference materials are provided. Use of these reference materials will aid in providing uniform standardization among measurements made by remedial action contractors. 11 refs., 9 tabs.

  11. Materials and structures

    NASA Technical Reports Server (NTRS)

    Saito, Theodore T.; Langenbeck, Sharon L.; Al-Jamily, Ghanim; Arnold, Joe; Barbee, Troy; Coulter, Dan; Dolgin, Ben; Fichter, Buck; George, Patricia; Gorenstein, Paul

    1992-01-01

    Materials and structures technology covers a wide range of technical areas. Some of the most pertinent issues for the Astrotech 21 missions include dimensionally stable structural materials, advanced composites, dielectric coatings, optical metallic coatings for low scattered light applications, low scattered light surfaces, deployable and inflatable structures (including optical), support structures in 0-g and 1-g environments, cryogenic optics, optical blacks, contamination hardened surfaces, radiation hardened glasses and crystals, mono-metallic telescopes and instruments, and materials characterization. Some specific examples include low coefficients of thermal expansion (CTE) structures (0.01 ppm/K), lightweight thermally stable mirror materials, thermally stable optical assemblies, high reliability/accuracy (1 micron) deployable structures, and characterization of nanometer level behavior of materials/structures for interferometry concepts. Large filled-aperture concepts will require materials with CTE's of 10(exp 9) at 80 K, anti-contamination coatings, deployable and erectable structures, composite materials with CTE's less than 0.01 ppm/K and thermal hysteresis, 0.001 ppm/K. Gravitational detection systems such as LAGOS will require rigid/deployable structures, dimensionally stable components, lightweight materials with low conductivity, and high stability optics. The Materials and Structures panel addressed these issues and the relevance of the Astrotech 21 mission requirements by dividing materials and structures technology into five categories. These categories, the necessary development, and applicable mission/program development phasing are summarized. For each of these areas, technology assessments were made and development plans were defined.

  12. Materials research for fusion

    NASA Astrophysics Data System (ADS)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to <2 MeV on average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  13. Engineering Living Functional Materials

    PubMed Central

    2016-01-01

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered ‘living functional materials’ and ‘living materials synthesis platforms’ that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater.13, 515–523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis–materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID

  14. NUCLEAR FUEL MATERIAL

    DOEpatents

    Goeddel, W.V.

    1962-06-26

    An improved method is given for making the carbides of nuclear fuel material. The metal of the fuel material, which may be a fissile and/or fertile material, is transformed into a silicide, after which the silicide is comminuted to the desired particle size. This silicide is then carburized at an elevated temperature, either above or below the melting point of the silicide, to produce an intimate mixture of the carbide of the fuel material and the carbide of silicon. This mixture of the fuel material carbide and the silicon carbide is relatively stable in the presence of moisture and does not exhibit the highly reactive surface condition which is observed with fuel material carbides made by most other known methods. (AEC)

  15. Ultrasonic nondestructive materials characterization

    NASA Technical Reports Server (NTRS)

    Green, R. E., Jr.

    1986-01-01

    A brief review of ultrasonic wave propagation in solid materials is presented with consideration of the altered behavior in anisotropic and nonlinear elastic materials in comparison with isotropic and linear elastic materials. Some experimental results are described in which ultrasonic velocity and attenuation measurements give insight into materials microstructure and associated mechanical properties. Recent developments with laser beam non-contact generation and detection of ultrasound are presented. The results of several years of experimental measurements using high-power ultrasound are discussed, which provide substantial evidence of the inability of presently accepted theories to fully explain the interaction of ultrasound with solid materials. Finally, a special synchrotron X-ray topographic system is described which affords the possibility of observing direct interaction of ultrasonic waves with the microstructural features of real crystalline solid materials for the first time.

  16. Femtosecond laser materials processing

    SciTech Connect

    Stuart, B. C., LLNL

    1998-06-02

    Femtosecond lasers enable materials processing of most any material with extremely high precision and negligible shock or thermal loading to the surrounding area Applications ranging from drilling teeth to cutting explosives to making high-aspect ratio cuts in metals with no heat-affected zone are made possible by this technology For material removal at reasonable rates, we developed a fully computer-controlled 15-Watt average power, 100-fs laser machining system.

  17. Material for Fast Cutting

    NASA Technical Reports Server (NTRS)

    Perez, A.

    1986-01-01

    New material for cutting tools increases productivity of machining processes. Material, called Iscanite (or equivalent), based on silicon nitride contains more than 90 percent silicon. Combines impact resistance close to that of coated carbides with heat and wear resistance close to those of aluminum oxide ceramics. Material used for cutting on old or new machine tools and makes it possible to exploit fully power and speed of machine.

  18. Emerging smart materials systems

    SciTech Connect

    Strock, H.B.

    1996-04-01

    Smart materials systems are nonliving systems that integrate the functions of sensing, actuation, logic and control to respond adaptively to changes in their condition or the environment to which they are exposed, in a useful and usually repetitive manner. Smart materials possess both sensing and actuation capability. They can adaptively respond to changing stimuli, e.g., the variable darkening of photochromic glass or plastic on exposure to sunlight. Such passively smart materials behavior has relatively limited, although marketable, functionality.

  19. Infrared fiber optic materials

    NASA Technical Reports Server (NTRS)

    Feigelson, Robert S.

    1987-01-01

    The development of IR fiber optics for use in astronomical and other space applications is summarized. Candidate materials were sought for use in the 1 to 200 micron and the 200 to 1000 micron wavelength range. Synthesis and optical characterization were carried out on several of these materials in bulk form. And the fabrication of a few materials in single crystal fiber optic form were studied.

  20. Research In Thermoelectric Materials

    NASA Technical Reports Server (NTRS)

    Wood, Charles

    1989-01-01

    Report reviews current research in thermoelectric materials with view towards development of materials of greater energy-conversion efficiency. Emphasis on effort to understand and manipulate microstructure to increase thermoelectric figure of merit, Z. Thermoelectric properties of three broad categories of materials discussed. First category includes alloys of group IV elements like silicon and germanium. Second category is rare-earth chalcogenides. Third category includes narrow-band semiconductors, especially boron carbides.

  1. ANS materials databook

    SciTech Connect

    Marchbanks, M.F.

    1995-08-01

    Technical development in the Advanced Neutron Source (ANS) project is dynamic, and a continuously updated information source is necessary to provide readily usable materials data to the designer, analyst, and materials engineer. The Advanced Neutron Source Materials Databook (AMBK) is being developed as a part of the Advanced Neutron Source Materials Information System (AMIS). Its purpose is to provide urgently needed data on a quick-turnaround support basis for those design applications whose schedules demand immediate estimates of material properties. In addition to the need for quick materials information, there is a need for consistent application of data throughout the ANS Program, especially where only limited data exist. The AMBK is being developed to fill this need as well. It is the forerunner to the Advanced Neutron Source Materials Handbook (AMHB). The AMHB, as reviewed and approved by the ANS review process, will serve as a common authoritative source of materials data in support of the ANS Project. It will furnish documented evidence of the materials data used in the design and construction of the ANS system and will serve as a quality record during any review process whose objective is to establish the safety level of the ANS complex. The information in the AMBK and AMHB is also provided in electronic form in a dial-up computer database known as the ANS Materials Database (AMDB). A single consensus source of materials information prepared and used by all national program participants has several advantages. Overlapping requirements and data needs of various sub-projects and subcontractors can be met by a single document which is continuously revised. Preliminary and final safety analysis reports, stress analysis reports, equipment specifications, materials service reports, and many other project-related documents can be substantially reduced in size and scope by appropriate reference to a single data source.

  2. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  3. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  4. Multilayer Insulation Material Guidelines

    NASA Technical Reports Server (NTRS)

    Finckenor, M. M.; Dooling, D.

    1999-01-01

    Multilayer Insulation Material Guidelines provides data on multilayer insulation materials used by previous spacecraft such as Spacelab and the Long-Duration Exposure Facility and outlines other concerns. The data presented in the document are presented for information only. They can be used as guidelines for multilayer insulation design for future spacecraft provided the thermal requirements of each new design and the environmental effects on these materials are taken into account.

  5. Flexible Material Systems Testing

    NASA Technical Reports Server (NTRS)

    Lin, John K.; Shook, Lauren S.; Ware, Joanne S.; Welch, Joseph V.

    2010-01-01

    An experimental program has been undertaken to better characterize the stress-strain characteristics of flexible material systems to support a NASA ground test program for inflatable decelerator material technology. A goal of the current study is to investigate experimental methods for the characterization of coated woven material stiffness. This type of experimental mechanics data would eventually be used to define the material inputs of fluid-structure interaction simulation models. The test methodologies chosen for this stress-strain characterization are presented along with the experimental results.

  6. Materials for Slack Diaphragms

    NASA Technical Reports Server (NTRS)

    Puschmann, Traute

    1940-01-01

    This report deals with systematic experiments carried out on five diaphragm materials with different pretreatment, for the purpose of ascertaining the suitability of such materials for slack diaphragms. The relationship of deflection and load, temperature and moisture, was recorded. Of the explored materials, synthetic leather, balloon cloth, goldbeaters skin, Igelit and Buna, synthetic leather treated with castor oil is the most suitable material for the small pressure range required. Balloon cloth is nearly as good, while goldbeaters skin, Igelit and Buna were found to be below the required standards.

  7. Thermoelectric materials having porosity

    SciTech Connect

    Heremans, Joseph P.; Jaworski, Christopher M.; Jovovic, Vladimir; Harris, Fred

    2014-08-05

    A thermoelectric material and a method of making a thermoelectric material are provided. In certain embodiments, the thermoelectric material comprises at least 10 volume percent porosity. In some embodiments, the thermoelectric material has a zT greater than about 1.2 at a temperature of about 375 K. In some embodiments, the thermoelectric material comprises a topological thermoelectric material. In some embodiments, the thermoelectric material comprises a general composition of (Bi.sub.1-xSb.sub.x).sub.u(Te.sub.1-ySe.sub.y).sub.w, wherein 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 1.8.ltoreq.u.ltoreq.2.2, 2.8.ltoreq.w.ltoreq.3.2. In further embodiments, the thermoelectric material includes a compound having at least one group IV element and at least one group VI element. In certain embodiments, the method includes providing a powder comprising a thermoelectric composition, pressing the powder, and sintering the powder to form the thermoelectric material.

  8. Fluorinated elastomeric materials

    DOEpatents

    Lagow, Richard J.; Dumitru, Earl T.

    1986-11-04

    This invention relates to a method of making perfluorinated elastomeric materials, and to materials made by such methods. In the full synthetic scheme, a partially fluorinated polymeric compound, with moieties to prevent crystallization, is created. It is then crosslinked to a desired degree, then perfluorinated. Various intermediate materials, such as partially fluorinated crosslinked polymers, have useful properties, and are or may become commercially available. One embodiment of this invention therefore relates to perfluorination of a selected partially fluorinated, crosslinked material, which is one step of the full synthetic scheme.

  9. Fluorinated elastomeric materials

    DOEpatents

    Lagow, Richard J.; Dumitru, Earl T.

    1990-02-13

    This invention relates to a method of making perfluorinated elastomeric materials, and to materials made by such methods. In the full synthetic scheme, a partially fluorinated polymeric compound, with moieties to prevent crystallization, is created. It is then crosslinked to a desired degree, then perfluorinated. Various intermediate materials, such as partially fluorinated crosslinked polymers, have useful properties, and are or may become commercially available. One embodiment of this invention therefore relates to perfluorination of a selected partially fluorinated, crosslinked material, which is one step of the full synthetic scheme.

  10. Material for radioactive protection

    DOEpatents

    Taylor, R.S.; Boyer, N.W.

    A boron containing burn resistant, low-level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source is described. The material is basically composed of borax in the range of 25 to 50%, coal tar in the range of 25 to 37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.