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Sample records for bone collagen stable

  1. Stable nitrogen isotope ratios of bone collagen reflect marine and terrestrial components of prehistoric human diet

    International Nuclear Information System (INIS)

    Schoeninger, M.J.; DeNiro, M.J.; Tauber, H.

    1983-01-01

    delta 15 N values of bone collagen from Eskimos and from Northwst Coast Indians dependent on salmon fishing are about 10 per mil more positive than those from agriculturalists in historic times. Among prehistoric humans, two groups dependent on marine food sources show bone collagen delta 15 N values that are 4 to 6 per mil more positive than those from two agricultural groups. The nitrogen isotope ratios of bone collagen from prehistoric inhabitants of Bahamas are anomalously low for reasons that relate to the biogeochemical cycle of nitrogen in coral reefs

  2. Bone collagen stable carbon and nitrogen isotope variability in modern South Australian mammals: A baseline for palaeoecological inferences.

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    Pate, F.D.; Anson, T.J.; Noble, A.H. [Flinders Univ. of South Australia, Bedford Park, SA (Australia). Department of Archaeology; Schoeninger, M.J. [Wisconsin Univ., Madison, WI (United States). Department of Anthropology

    1997-12-31

    Cortical bone samples were collected from a range of modern mammals at four field sites along a 1225 km north-south transect from temperate coastal to arid interior South Australia in order to address variability in stable carbon and nitrogen isotope composition. Collection sites were located along the eastern border of the state and included Mount Gambier, Karte, Plumbago and Innamincka. Mean annual rainfall along the transect ranges from 700-800 mm at Mount Gambier to 150-200 mm at Innamincka. Bone collagen carbon and nitrogen isotope values become more positive toward the arid north in relation to increasing quantities of C-4 plants and decreasing amounts of rainfall. respectively. In addition, carnivores and herbivores can be differentiated by stable nitrogen isotope values. On average, carnivore bone collagen is approximately 6 per mil more positive than that of rabbits at Mount Gambier but only 2.6 - 3.4 per mil more positive at the three arid collection sites. In general, the large eutherian herbivores have mean bone collagen {delta}15N values that are 1.4 - 2.3 per mil more positive than those of the marsupial herbivores. Eutherian and marsupial bone collagen {delta}15N differences only disappear at the most arid collection site, Innamincka.

  3. Investigating adult diet during Industrialization in Copenhagen based on stable isotope analysis of bone collagen and hair keratin

    DEFF Research Database (Denmark)

    Jørkov, M L S; Gröcke, Darren R

    2017-01-01

    This study investigated human diets during the nineteenth and twentieth century in Copenhagen through stable isotope analysis of carbon and nitrogen according to sex, age, socio-economic status, and period (of death). Stable isotope analysis was conducted on bone collagen (n = 114) and hair keratin...... in elevating baseline δ15N values was not detected. Overall isotopic results indicate a diet rich in protein from brackish fish and terrestrial C3-based animal products with a larger dietary diversity among males during the twentieth century. Male diet may have been more affected by economical means than...

  4. Carbon and nitrogen stable isotopes of well-preserved Middle Pleistocene bone collagen from Schöningen (Germany) and their paleoecological implications.

    Science.gov (United States)

    Kuitems, Margot; van der Plicht, Johannes; Drucker, Dorothée G; Van Kolfschoten, Thijs; Palstra, Sanne W L; Bocherens, Hervé

    2015-12-01

    Carbon and nitrogen stable isotopes in bone collagen can provide valuable information about the diet and habitat of mammal species. However, bone collagen degrades in normal circumstances very rapidly, and isotope analyses are therefore usually restricted to fossil material with a Late Pleistocene or Holocene age. The Middle Pleistocene site of Schöningen, dated to around 300,000 years ago, yielded bones and teeth with an exceptionally good state of collagen preservation. This allowed us to measure reliable biogenic carbon and nitrogen stable isotope ratios for different herbivorous taxa from the families Elephantidae, Rhinocerotidae, Equidae, Cervidae, and Bovidae. The results provide insights regarding the paleoenvironmental setting in which Middle Pleistocene hominins operated. The vegetation consumed by the herbivores from the famous spear horizon originates from open environments. During the climatic Reinsdorf Interglacial optimum, the landscape seems to have been relatively open as well, but certainly included parts that were forested. The results also indicate some niche partitioning; different herbivore species used different plant resources. For instance, the horses seem to have been predominantly browsers, while the straight-tusked elephants were feeding chiefly on grass. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Stable carbon isotope variability of bone collagen and hair within a modern population of red kangaroos (Macropus rufus) in south western Queensland: some implications for palaeoecological research

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    Witt, G.B. [Queensland Univ., St. Lucia, QLD (Australia)

    1997-12-31

    Full text: Before any palaeo-reconstruction work can be attempted using stable isotope analysis of macropod remains it will be necessary to determine the nature of natural variability within contemporary populations. This research indicates that {delta}{sup 13}C of bone collagen is strongly related to age. Furthermore, bone collagen {delta}{sup 13}C not at equilibrium with dietary {delta}{sup 13}C, as indicated by analysis of hair, until animals are several years old. These preliminary data suggest that in younger macropods most carbon in bone collagen has been derived via the mother`s milk which may have undergone fractionation. These findings have significant implications for any palaeoecological research using bone or tooth. Teeth of macropods erupt from the rear of the jaw and move forward in molar progression. Since the rate of eruption is variable, and many of the forward molars are well formed while the joey is still at the pouch, teeth formed early in the life of a macropod may be isotopically distinct from those that develop later. This hypothesis is currently under investigation.

  6. Approach to the human diet of the punic population of Can Marines (Ibiza. C an N stable isotope analysis on bone collagen

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    Domingo Carlos Salazar García

    2012-09-01

    Full Text Available We report here on the results of carbon and nitrogen stable isotope analysis on bone collagen of humans from the Punic site of Can Marines (V-IVth BC from the island of Ibiza (Spain. To date, there are few isotopic studies for this period from the Mediterranean. This article reports new isotopic data from a Western Mediterranean Punic rural settlement. The results show a terrestrial based diet with no isotopic evidence of marine or freshwater protein input, and suggest the presence of C4 resources in it.

  7. Analyses of stable isotopes in camelids collagen bones from Tulan Ravine, Atacama Puna, early formative period (CA 3,1000-2,400BP)

    International Nuclear Information System (INIS)

    Lopez, Patricio; Cartajena, Isabel; Nunez, Lautaro

    2013-01-01

    This paper presents the results of isotope analysis (δ 13 C y δ 15 N) conducted on bone collagen found in Lama guanicoe and Lama glama remains from Tulan-85 and Tulan-54 archaeological sites. Both sites have been dated to the Early Formative Period (ca. 3,100-2,400 ap) and are located southeast of the Atacama Puna basin. Faunal samples were selected using anatomical and morphometric criteria. The results indicate divergences in the diets of both species, reflecting vegetation variation in the Tulan Quebrada caused by altitude differences and linked to hunting and herding areas [es

  8. Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry

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    Takashi Matsuura

    2014-01-01

    Full Text Available Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

  9. High-strength mineralized collagen artificial bone

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    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  10. Second-harmonic generation imaging of collagen in ancient bone.

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    Thomas, B; McIntosh, D; Fildes, T; Smith, L; Hargrave, F; Islam, M; Thompson, T; Layfield, R; Scott, D; Shaw, B; Burrell, C L; Gonzalez, S; Taylor, S

    2017-12-01

    Second-harmonic generation imaging (SHG) captures triple helical collagen molecules near tissue surfaces. Biomedical research routinely utilizes various imaging software packages to quantify SHG signals for collagen content and distribution estimates in modern tissue samples including bone. For the first time using SHG, samples of modern, medieval, and ice age bones were imaged to test the applicability of SHG to ancient bone from a variety of ages, settings, and taxa. Four independent techniques including Raman spectroscopy, FTIR spectroscopy, radiocarbon dating protocols, and mass spectrometry-based protein sequencing, confirm the presence of protein, consistent with the hypothesis that SHG imaging detects ancient bone collagen. These results suggest that future studies have the potential to use SHG imaging to provide new insights into the composition of ancient bone, to characterize ancient bone disorders, to investigate collagen preservation within and between various taxa, and to monitor collagen decay regimes in different depositional environments.

  11. Second-harmonic generation imaging of collagen in ancient bone

    Directory of Open Access Journals (Sweden)

    B. Thomas

    2017-12-01

    Full Text Available Second-harmonic generation imaging (SHG captures triple helical collagen molecules near tissue surfaces. Biomedical research routinely utilizes various imaging software packages to quantify SHG signals for collagen content and distribution estimates in modern tissue samples including bone. For the first time using SHG, samples of modern, medieval, and ice age bones were imaged to test the applicability of SHG to ancient bone from a variety of ages, settings, and taxa. Four independent techniques including Raman spectroscopy, FTIR spectroscopy, radiocarbon dating protocols, and mass spectrometry-based protein sequencing, confirm the presence of protein, consistent with the hypothesis that SHG imaging detects ancient bone collagen. These results suggest that future studies have the potential to use SHG imaging to provide new insights into the composition of ancient bone, to characterize ancient bone disorders, to investigate collagen preservation within and between various taxa, and to monitor collagen decay regimes in different depositional environments.

  12. Changes in tissue morphology and collagen composition during the repair of cortical bone in the adult chicken.

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    Glimcher, M J; Shapiro, F; Ellis, R D; Eyre, D R

    1980-09-01

    An animal model was developed to study the histology and collagen chemistry of healing cortical bone. A hole was cut through the cortex of the mid-shaft of the humerus of the adult chicken, which allowed for repair at a mechanically stable site. After one to two weeks the collagen of the repair tissue, which consisted principally of woven bone, contained almost three times as much hydroxylysine as the collagen of normal adult bone and thus resembled the collagen of embryonic long bones. By eight weeks, when lamellar one predominated, the hydroxylysine content had fallen to normal levels. Type I was the major genetic type of collagen present throughout. No type-II collagen, characteristic of cartilage, was detected; this was consistent with the histological findings. The results established that hydroxylysine-rich type-I collagen can be made by osteoblasts of adult animals as well as by those of embryos and early postnates. In order to understand the biological characteristics of fracture healing, it is vital to study not only the macroscopic organization of the repair tissue but also the chemical properties of its molecular components. The strength of healing fractured bone, and indeed of normal bone, depends largely on the properties of the structural protein collagen. To date, it is not known whether the collagen in healing fractures is the same as that in normal bone, or whether it has distinct chemical features that may suit it for bone repair.

  13. Degradation pattern of a porcine collagen membrane in an in vivo model of guided bone regeneration.

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    Calciolari, E; Ravanetti, F; Strange, A; Mardas, N; Bozec, L; Cacchioli, A; Kostomitsopoulos, N; Donos, N

    2018-02-15

    Although collagen membranes have been clinically applied for guided tissue/bone regeneration for more than 30 years, their in vivo degradation pattern has never been fully clarified. A better understanding of the different stages of in vivo degradation of collagen membranes is extremely important, considering that the biology of bone regeneration requires the presence of a stable and cell/tissue-occlusive barrier during the healing stages in order to ensure a predictable result. Therefore, the aim of this study was to investigate the degradation pattern of a porcine non-cross-linked collagen membrane in an in vivo model of guided bone regeneration (GBR). Decalcified and paraffin-embedded specimens from calvarial defects of 18, 10-month-old Wistar rats were used. The defects were treated with a double layer of collagen membrane and a deproteinized bovine bone mineral particulate graft. At 7, 14 and 30 days of healing, qualitative evaluation with scanning electron microscopy and atomic force microscopy, and histomorphometric measurements were performed. Markers of collagenase activity and bone formation were investigated using an immunofluorescence technique. A significant reduction of membrane thickness was observed from 7 to 30 days of healing, which was associated with progressive loss of collagen alignment, increased collagen remodeling and progressive invasion of woven bone inside the membranes. A limited inflammatory infiltrate was observed at all time points of healing. The collagen membrane investigated was biocompatible and able to promote bone regeneration. However, pronounced signs of degradation were observed starting from day 30. Since successful regeneration is obtained only when cell occlusion and space maintenance exist for the healing time needed by the bone progenitor cells to repopulate the defect, the suitability of collagen membranes in cases where long-lasting barriers are needed needs to be further reviewed. © 2018 John Wiley & Sons A

  14. Nitrogen and carbon isotopic composition of bone collagen from marine and terrestrial animals

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    Schoeninger, Margaret J.; DeNiro, Michael J.

    1984-04-01

    The stable nitrogen and carbon isotope ratios of bone collagen prepared from more than 100 animals representing 66 species of birds, fish, and mammals are presented. The δ15N values of bone collagen from animals that fed exclusively in the marine environment are, on average, 9%. more positive than those from animals that fed exclusively in the terrestrial environment; ranges for the two groups overlap by less than 1%. Bone collagen δ15N values also serve to separate marine fish from the small number of freshwater fish we analyzed. The bone collagen δ15N values of birds and fish that spent part of their life cycles feeding in the marine environment and part in the freshwater environment are intermediate between those of animals that fed exclusively in one or the other system. Further, animals that fed at successive trophic levels in the marine and terrestrial environment are separated, on average, by a 3%. difference in the δ15N values of their bone collagen. Specifically, carnivorous and herbivorous terrestrial animals have mean δ15N values for bone collagen of + 8.0 and + 5.3%., respectively. Among marine animals, those that fed on fish have a mean δ15N value for bone collagen of + 16.5%., whereas those that fed on invertebrates have a mean δ15N value of + 13.3%. These results support previous suggestions of a 3%. enrichment in δ15N values at each successively higher trophic level. In contrast to the results for δ15N values, the ranges of bone collagen δ13C values from marine and terrestrial feeders overlap to a great extent. Additionally, bone collagen δ13C values do not reflect the trophic levels at which the animals fed. These results indicate that bone collagen δ15N values will be useful in determining relative dependence on marine and terrestrial food sources and in investigating trophic level relationships among different animal species within an ecosystem. This approach should be applicable to animals represented by prehistoric or fossilized

  15. Collagen XII: Protecting bone and muscle integrity by organizing collagen fibrils.

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    Chiquet, Matthias; Birk, David E; Bönnemann, Carsten G; Koch, Manuel

    2014-08-01

    Collagen XII, largest member of the fibril-associated collagens with interrupted triple helix (FACIT) family, assembles from three identical α-chains encoded by the COL12A1 gene. The molecule consists of three threadlike N-terminal noncollagenous NC3 domains, joined by disulfide bonds and a short interrupted collagen triple helix toward the C-terminus. Splice variants differ considerably in size and properties: "small" collagen XIIB (220 kDa subunit) is similar to collagen XIV, whereas collagen XIIA (350 kDa) has a much larger NC3 domain carrying glycosaminoglycan chains. Collagen XII binds to collagen I-containing fibrils via its collagenous domain, whereas its large noncollagenous arms interact with other matrix proteins such as tenascin-X. In dense connective tissues and bone, collagen XII is thought to regulate organization and mechanical properties of collagen fibril bundles. Accordingly, recent findings show that collagen XII mutations cause Ehlers-Danlos/myopathy overlap syndrome associated with skeletal abnormalities and muscle weakness in mice and humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Biological effect of hydrolyzed collagen on bone metabolism.

    Science.gov (United States)

    Daneault, Audrey; Prawitt, Janne; Fabien Soulé, Véronique; Coxam, Véronique; Wittrant, Yohann

    2017-06-13

    Osteoporosis is a chronic and asymptomatic disease characterized by low bone mass and skeletal microarchitectural deterioration, increased risk of fracture, and associated comorbidities most prevalent in the elderly. Due to an increasingly aging population, osteoporosis has become a major health issue requiring innovative disease management. Proteins are important for bone by providing building blocks and by exerting specific regulatory function. This is why adequate protein intake plays a considerable role in both bone development and bone maintenance. More specifically, since an increase in the overall metabolism of collagen can lead to severe dysfunctions and a more fragile bone matrix and because orally administered collagen can be digested in the gut, cross the intestinal barrier, enter the circulation, and become available for metabolic processes in the target tissues, one may speculate that a collagen-enriched diet provides benefits for the skeleton. Collagen-derived products such as gelatin or hydrolyzed collagen (HC) are well acknowledged for their safety from a nutritional point of view; however, what is their impact on bone biology? In this manuscript, we critically review the evidence from literature for an effect of HC on bone tissues in order to determine whether HC may represent a relevant alternative in the design of future nutritional approaches to manage osteoporosis prevention.

  17. Nitrogen and carbon isotopic composition of bone collagen from marine and terrestrial animals

    International Nuclear Information System (INIS)

    Schoeninger, M.J.; DeNiro, M.J.

    1984-01-01

    The stable nitrogen and carbon isotope ratios of bone collagen prepared from more than 100 animals representing 66 species of birds, fish, and mammals are presented. The delta 15 N values of bone collagen from animals that fed exclusively in the marine environment are, on average, 9 per mille more positive than those from animals that fed exclusively in the terrestrial environment: ranges for the two groups overlap by less than 1 per mille. Bone collagen delta 15 N values also serve to separate marine fish from the small number of freshwater fish we analyzed. The bone collagen delta 15 N values of birds and fish that spent part of their life cycles feeding in the marine environment and part in the freshwater environment are intermediate between those of animals that fed exclusively in one or the other system. Further, animals that fed at successive trophic levels in the marine and terrestrial environment are separated, on average, by a 3 per mille difference in the delta 15 N values of their bone collagen. Results are given and discussed. (author)

  18. Effect of collagen denaturation on the toughness of bone

    NARCIS (Netherlands)

    Wang, X.; Bank, R.A.; TeKoppele, J.M.; Hubbard, G.B.; Athanasiou, K.A.; Agrawal, C.M.

    2000-01-01

    The purpose of this study was to explore the relationship between the integrity of collagen and biomechanical properties of bone. In this study, age (range, 5-26 years old) and gender related changes in cortical bone samples from 33 baboon femurs (15 males and 18 females) were examined. The

  19. Collagen-derived markers of bone metabolism in osteogenesis imperfecta

    DEFF Research Database (Denmark)

    Lund, A M; Hansen, M; Kollerup, Gina Birgitte

    1998-01-01

    )] were measured in 78 osteogenesis imperfecta (OI) patients to investigate bone metabolism in vivo and relate marker concentrations to phenotype and in vitro collagen I defects, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). PICP and PINP were generally low....... The in vivo findings correlated with in vitro results of collagen I SDS-PAGE. Bone turnover is reduced in OI children and mildly affected OI adults, whereas bone resorption is elevated in severely affected adults. These findings may prove helpful for diagnosis and decision-making regarding therapy in OI....

  20. Octacalcium phosphate collagen composite facilitates bone regeneration of large mandibular bone defect in humans.

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    Kawai, Tadashi; Suzuki, Osamu; Matsui, Keiko; Tanuma, Yuji; Takahashi, Tetsu; Kamakura, Shinji

    2017-05-01

    Recently it was reported that the implantation of octacalcium phosphate (OCP) and collagen composite (OCP-collagen) was effective at promoting bone healing in small bone defects after cystectomy in humans. In addition, OCP-collagen promoted bone regeneration in a critical-sized bone defect of a rodent or canine model. In this study, OCP-collagen was implanted into a human mandibular bone defect with a longer axis of approximately 40 mm, which was diagnosed as a residual cyst with apical periodontitis. The amount of OCP-collagen implanted was about five times greater than the amounts implanted in previous clinical cases. Postoperative wound healing was satisfactory and no infection or allergic reactions occurred. The OCP-collagen-treated lesion was gradually filled with radio-opaque figures, and the alveolar region occupied the whole of the bone defect 12 months after implantation. This study suggests that OCP-collagen could be a useful bone substitute material for repairing large bone defects in humans that might not heal spontaneously. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Collagen-derived markers of bone metabolism in osteogenesis imperfecta

    DEFF Research Database (Denmark)

    Lund, A M; Hansen, M; Kollerup, Gina Birgitte

    1998-01-01

    )] were measured in 78 osteogenesis imperfecta (OI) patients to investigate bone metabolism in vivo and relate marker concentrations to phenotype and in vitro collagen I defects, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). PICP and PINP were generally low...

  2. A biocomposite of collagen nanofibers and nanohydroxyapatite for bone regeneration

    NARCIS (Netherlands)

    Ribeiro, N.; Sousa, S.R.; van Blitterswijk, Clemens; Moroni, Lorenzo; Monteiro, F.J.

    2014-01-01

    This work aims to design a synthetic construct that mimics the natural bone extracellular matrix through innovative approaches based on simultaneous type I collagen electrospinning and nanophased hydroxyapatite (nanoHA) electrospraying using non-denaturating conditions and non-toxic reagents. The

  3. Effect of water on piezoelectricity in bone and collagen.

    Science.gov (United States)

    Netto, T G; Zimmerman, R L

    1975-01-01

    Interferometric measurements of bovine bone and tendon show that the values of the piezoelectric strain constant d14 decrease with hydration from the dry values of 0.2 X 10(-14) and 2.0 X 10(-14) m/V, respectively. The decrease of piezoelectricity in tendon is exponential with a characteristic hydration of 7% by weight from which an upper limit of the average molecular weight of the responsible electric dipole moments is deduced. The piezoelectricity in bone decreases relatively slowly with hydration indicating that the electric dipoles in bone collagen are subject to a different cancelling mechanism. PMID:1148359

  4. The Structure and Function of Non-Collagenous Bone Proteins

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    Hook, Magnus; McQuillan, David J.

    1997-01-01

    The research done under the cooperative research agreement for the project titled 'The structure and function of non-collagenous bone proteins' represented the first phase of an ongoing program to define the structural and functional relationships of the principal noncollagenous proteins in bone. An ultimate goal of this research is to enable design and execution of useful pharmacological compounds that will have a beneficial effect in treatment of osteoporosis, both land-based and induced by long-duration space travel. The goals of the now complete first phase were as follows: 1. Establish and/or develop powerful recombinant protein expression systems; 2. Develop and refine isolation and purification of recombinant proteins; 3. Express wild-type non-collagenous bone proteins; 4. Express site-specific mutant proteins and domains of wild-type proteins to enhance likelihood of crystal formation for subsequent solution of structure.

  5. Amino acid δ13C analysis of hair proteins and bone collagen using liquid chromatography/isotope ratio mass spectrometry

    DEFF Research Database (Denmark)

    Raghavan, Maanasa; McCullagh, James S. O.; Lynnerup, Niels

    2010-01-01

    We report a novel method for the chromatographic separation and measurement of stable carbon isotope ratios (delta(13)C) of individual amino acids in hair proteins and bone collagen using the LC-IsoLink system, which interfaces liquid chromatography (LC) with isotope ratio mass spectrometry (IRMS......). This paper provides baseline separation of 15 and 13 of the 18 amino acids in bone collagen and hair proteins, respectively. We also describe an approach to analysing small hair samples for compound-specific analysis of segmental hair sections. The LC/IRMS method is applied in a historical context...... by the delta(13)C analysis of hair proteins and bone collagen recovered from six individuals from Uummannaq in Greenland. The analysis of hair and bone amino acids from the same individual, compared for the first time in this study, is of importance in palaeodietary reconstruction. If hair proteins can be used...

  6. Isotopic signatures in ancient bone collagen; Signatures isotopiques dans le collagene des os anciens

    Energy Technology Data Exchange (ETDEWEB)

    Bocherens, H. [Universite Pierre et Marie Curie, CNRS-INRA-UPMC, 75 - Paris (France). Laboratoire de Biogeochimie Isotopique

    1997-07-01

    Collagen can be preserved during tens of thousands of years in bones and teeth under favorable conditions. Natural isotopic abundances in carbon ({sup 13}C/{sup 12}C) and in nitrogen ({sup 15}N/{sup 14}N) of ancients bone and tooth collagen correspond to those recorded during the biogenic synthesis and have not been significantly altered during fossilization. These isotopic abundances are linked to those of the proteic fraction of animal and human diets, and to physiological conditions. Three kinds of applications are made possible through these natural isotopic signatures: determination of subsistence strategies in ancient human populations, determination of the diet of extinct species and the analysis of past environmental changes. (author)

  7. Compositional and in Vitro Evaluation of Nonwoven Type I Collagen/Poly-dl-lactic Acid Scaffolds for Bone Regeneration.

    Science.gov (United States)

    Qiao, Xiangchen; Russell, Stephen J; Yang, Xuebin; Tronci, Giuseppe; Wood, David J

    2015-08-05

    Poly-dl-lactic acid (PDLLA) was blended with type I collagen to attempt to overcome the instantaneous gelation of electrospun collagen scaffolds in biological environments. Scaffolds based on blends of type I collagen and PDLLA were investigated for material stability in cell culture conditions (37 °C; 5% CO2) in which post-electrospinning glutaraldehyde crosslinking was also applied. The resulting wet-stable webs were cultured with bone marrow stromal cells (HBMSC) for five weeks. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), Fourier transform infra-red spectroscopy (FTIR) and biochemical assays were used to characterise the scaffolds and the consequent cell-scaffold constructs. To investigate any electrospinning-induced denaturation of collagen, identical PDLLA/collagen and PDLLA/gelatine blends were electrospun and their potential to promote osteogenic differentiation investigated. PDLLA/collagen blends with w/w ratios of 40/60, 60/40 and 80/20 resulted in satisfactory wet stabilities in a humid environment, although chemical crosslinking was essential to ensure long term material cell culture. Scaffolds of PDLLA/collagen at a 60:40 weight ratio provided the greatest stability over a five-week culture period. The PDLLA/collagen scaffolds promoted greater cell proliferation and osteogenic differentiation compared to HMBSCs seeded on the corresponding PDLLA/gelatine scaffolds, suggesting that any electrospinning-induced collagen denaturation did not affect material biofunctionality within 5 weeks in vitro.

  8. Compositional and in Vitro Evaluation of Nonwoven Type I Collagen/Poly-dl-lactic Acid Scaffolds for Bone Regeneration

    Science.gov (United States)

    Qiao, Xiangchen; Russell, Stephen J.; Yang, Xuebin; Tronci, Giuseppe; Wood, David J.

    2015-01-01

    Poly-dl-lactic acid (PDLLA) was blended with type I collagen to attempt to overcome the instantaneous gelation of electrospun collagen scaffolds in biological environments. Scaffolds based on blends of type I collagen and PDLLA were investigated for material stability in cell culture conditions (37 °C; 5% CO2) in which post-electrospinning glutaraldehyde crosslinking was also applied. The resulting wet-stable webs were cultured with bone marrow stromal cells (HBMSC) for five weeks. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), Fourier transform infra-red spectroscopy (FTIR) and biochemical assays were used to characterise the scaffolds and the consequent cell-scaffold constructs. To investigate any electrospinning-induced denaturation of collagen, identical PDLLA/collagen and PDLLA/gelatine blends were electrospun and their potential to promote osteogenic differentiation investigated. PDLLA/collagen blends with w/w ratios of 40/60, 60/40 and 80/20 resulted in satisfactory wet stabilities in a humid environment, although chemical crosslinking was essential to ensure long term material cell culture. Scaffolds of PDLLA/collagen at a 60:40 weight ratio provided the greatest stability over a five-week culture period. The PDLLA/collagen scaffolds promoted greater cell proliferation and osteogenic differentiation compared to HMBSCs seeded on the corresponding PDLLA/gelatine scaffolds, suggesting that any electrospinning-induced collagen denaturation did not affect material biofunctionality within 5 weeks in vitro. PMID:26251924

  9. Compositional and in Vitro Evaluation of Nonwoven Type I Collagen/Poly-dl-lactic Acid Scaffolds for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Xiangchen Qiao

    2015-08-01

    Full Text Available Poly-dl-lactic acid (PDLLA was blended with type I collagen to attempt to overcome the instantaneous gelation of electrospun collagen scaffolds in biological environments. Scaffolds based on blends of type I collagen and PDLLA were investigated for material stability in cell culture conditions (37 °C; 5% CO2 in which post-electrospinning glutaraldehyde crosslinking was also applied. The resulting wet-stable webs were cultured with bone marrow stromal cells (HBMSC for five weeks. Scanning electron microscopy (SEM, confocal laser scanning microscopy (CLSM, Fourier transform infra-red spectroscopy (FTIR and biochemical assays were used to characterise the scaffolds and the consequent cell-scaffold constructs. To investigate any electrospinning-induced denaturation of collagen, identical PDLLA/collagen and PDLLA/gelatine blends were electrospun and their potential to promote osteogenic differentiation investigated. PDLLA/collagen blends with w/w ratios of 40/60, 60/40 and 80/20 resulted in satisfactory wet stabilities in a humid environment, although chemical crosslinking was essential to ensure long term material cell culture. Scaffolds of PDLLA/collagen at a 60:40 weight ratio provided the greatest stability over a five-week culture period. The PDLLA/collagen scaffolds promoted greater cell proliferation and osteogenic differentiation compared to HMBSCs seeded on the corresponding PDLLA/gelatine scaffolds, suggesting that any electrospinning-induced collagen denaturation did not affect material biofunctionality within 5 weeks in vitro.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    Osteoblast recruitment during bone remodeling is obligatory to re-construct the bone resorbed by the osteoclast. This recruitment is believed to be triggered by osteoclast products and is therefore likely to start early during the remodeling cycle. Several osteoclast products with osteoblast...... recruitment potential are already known. Here we draw the attention on the osteoblast recruitment potential of the collagen that is freshly demineralized by the osteoclast. Our evidence is based on observations on adult human cancellous bone, combined with in vitro assays. First, freshly eroded surfaces where...... and cell migration in various cell types, and whose inactivation is reported to lead to lack of bone formation and skeletal deformities. In the present study, an antibody directed against this receptor inhibits collagen internalization in osteoblast lineage cells and decreases to some extent...

  11. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Directory of Open Access Journals (Sweden)

    Chou YC

    2016-08-01

    Full Text Available Ying-Chao Chou,1,2 Wen-Lin Yeh,2 Chien-Lin Chao,1 Yung-Heng Hsu,1,2 Yi-Hsun Yu,1,2 Jan-Kan Chen,3 Shih-Jung Liu1,2 1Department of Mechanical Engineering, Chang Gung University, 2Department of Orthopedic Surgery, Chang Gung Memorial Hospital, 3Department of Physiology and Pharmacology, Chang Gung University, Taoyuan, Taiwan Abstract: A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA bolt as the bone anchor and a poly(D,L-lactide-co-glycolide (PLGA nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. Keywords: polylactide–polyglycolide nanofibers, PLGA, collagen, 3D printing, polylactide, PLA, bone-anchoring bolts, tendon healing

  12. Alveolar socket preservation with demineralised bovine bone mineral and a collagen matrix.

    Science.gov (United States)

    Maiorana, Carlo; Poli, Pier Paolo; Deflorian, Matteo; Testori, Tiziano; Mandelli, Federico; Nagursky, Heiner; Vinci, Raffaele

    2017-08-01

    The aim of the present study was to evaluate the healing of post-extraction sockets following alveolar ridge preservation clinically, radiologically, and histologically. Overall, 7 extraction sockets in 7 patients were grafted with demineralised bovine bone mineral and covered with a porcine-derived non-crosslinked collagen matrix (CM). Soft tissue healing was clinically evaluated on the basis of a specific healing index. Horizontal and vertical ridge dimensional changes were assessed clinically and radiographically at baseline and 6 months after implant placement. For histological and histomorphometric analysis, bone biopsies were harvested from the augmented sites during implant surgery 6 months after the socket preservation procedure. Clinically, healing proceeded uneventfully in all the sockets. A trend towards reduced horizontal and vertical socket dimensions was observed from baseline to the final examination. The mean width and height of resorption were 1.21 mm ( P =0.005) and 0.46 mm ( P =0.004), respectively. Histologically, residual xenograft particles (31.97%±3.52%) were surrounded by either newly formed bone (16.02%±7.06%) or connective tissue (50.67%±8.42%) without fibrous encapsulation. The CM underwent a physiological substitution process in favour of well-vascularised collagen-rich connective tissue. Socket preservation using demineralised bovine bone mineral in combination with CM provided stable dimensional changes of the alveolar ridge associated with good re-epithelialisation of the soft tissues during a 6-month healing period.

  13. Phagocytosis of bone collagen by osteoclasts in two cases of pycnodysostosis

    NARCIS (Netherlands)

    Everts, V.; Aronson, D. C.; Beertsen, W.

    1985-01-01

    Electron microscopic examination of bone biopsies obtained from two patients suffering from pycnodysostosis revealed that osteoclasts contained (sometimes large) cytoplasmic vacuoles filled with bone collagen fibrils. These vacuoles stained positive for acid phosphatase activity, thereby suggesting

  14. Differential actions of the endocytic collagen receptor uPARAP/Endo180 and the collagenase MMP-2 in bone homeostasis

    DEFF Research Database (Denmark)

    Madsen, Daniel H; Jürgensen, Henrik J; Ingvarsen, Signe

    2013-01-01

    A well-coordinated remodeling of uncalcified collagen matrices is a pre-requisite for bone development and homeostasis. Collagen turnover proceeds through different pathways, either involving extracellular reactions exclusively, or being dependent on endocytic processes. Extracellular collagen...

  15. Clinical observation of biomimetic mineralized collagen artificial bone putty for bone reconstruction of calcaneus fracture

    Science.gov (United States)

    Pan, Yong-Xiong; Yang, Guang-Gang; Li, Zhong-Wan; Shi, Zhong-Min; Sun, Zhan-Dong

    2018-01-01

    Abstract This study investigated clinical outcomes of biomimetic mineralized collagen artificial bone putty for bone reconstruction in the treatment of calcaneus fracture. Sixty cases of calcaneal fractures surgically treated with open reduction and internal fixation in our hospital from June 2014–2015 were chosen and randomly divided into two groups, including 30 cases treated with biomimetic mineralized collagen artificial bone putty as treatment group, and 30 cases treated with autogenous ilia as control group. The average follow-up time was 17.2 ± 3.0 months. The results showed that the surgery duration and postoperative drainage volume of treatment group were significantly lower than control group; there were no statistically significant differences in the fracture healing time, American Orthopaedic Foot and Ankle Society scores at 3 and 12 months after surgery, Böhler’s angle, Gissane’s angle and height of calcaneus between the two groups. There were no significant differences in wound complication and reject reaction between the two groups, while significant difference in donor site complication. As a conclusion, the implantation of biomimetic mineralized collagen artificial bone putty in the open reduction of calcaneal fracture resulted in reliable effect and less complications, which is suitable for clinical applications in the treatment of bone defect in calcaneal fractures.

  16. Abnormal bone collagen morphology and decreased bone strength in growth hormone-deficient rats

    DEFF Research Database (Denmark)

    Lange, Martin; Qvortrup, Klaus; Svendsen, Ole Lander

    2004-01-01

    Patients with growth hormone deficiency (GHD) have an increased risk of bone fractures. In these patients, the well-described decrease in bone mineral density (BMD) and content (BMC) may, however, not alone explain the increase in fracture rate. Accordingly, the aim of this study was to evaluate......% and growth rate to approximately 40-50% when compared to normal control rats. Five male Dw-4 rats were examined at age 12 weeks and five healthy Lewis rats served as age-matched controls. The animals were examined for (1) bone mineral status by dual energy X-ray absorptometry (DXA) and ash weight/bone volume......, (2) biomechanical properties, (3) serum insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3), and (4) collagen morphology of cortical bone from the right femurs was examined by scanning and transmission electron microscopy. A significant decrease was found in serum IGF-I, IGFBP-3...

  17. Treatment with eldecalcitol positively affects mineralization, microdamage, and collagen crosslinks in primate bone.

    Science.gov (United States)

    Saito, Mitsuru; Grynpas, Marc D; Burr, David B; Allen, Matthew R; Smith, Susan Y; Doyle, Nancy; Amizuka, Norio; Hasegawa, Tomoka; Kida, Yoshikuni; Marumo, Keishi; Saito, Hitoshi

    2015-04-01

    Eldecalcitol (ELD), an active form of vitamin D analog approved for the treatment of osteoporosis in Japan, increases lumbar spine bone mineral density (BMD), suppresses bone turnover markers, and reduces fracture risk in patients with osteoporosis. We have previously reported that treatment with ELD for 6 months improved the mechanical properties of the lumbar spine in ovariectomized (OVX) cynomolgus monkeys. ELD treatment increased lumbar BMD, suppressed bone turnover markers, and reduced histomorphometric parameters of both bone formation and resorption in vertebral trabecular bone. In this study, we elucidated the effects of ELD on bone quality (namely, mineralization, microarchitecture, microdamage, and bone collagen crosslinks) in OVX cynomolgus monkeys in comparison with OVX-vehicle control monkeys. Density fractionation of bone powder prepared from lumbar vertebrae revealed that ELD treatment shifted the distribution profile of bone mineralization to a higher density, and backscattered electron microscopic imaging showed improved trabecular bone connectivity in the ELD-treated groups. Higher doses of ELD more significantly reduced the amount of microdamage compared to OVX-vehicle controls. The fractionated bone powder samples were divided according to their density, and analyzed for collagen crosslinks. Enzymatic crosslinks were higher in both the high-density (≥2.0 mg/mL) and low-density (mineralization, but prevented non-enzymatic reaction of collagen crosslinks and accumulation of bone microdamage. Bone anti-resorptive agents such as bisphosphonates slow down bone remodeling so that bone mineralization, bone microdamage, and non-enzymatic collagen crosslinks all increase. Bone anabolic agents such as parathyroid hormone decrease bone mineralization and bone microdamage by stimulating bone remodeling. ELD did not fit into either category. Histological analysis indicated that the ELD treatment strongly suppressed bone resorption by reducing the number of

  18. The effect of bone marrow aspirate, bone graft and collagen composites on fixation of bone implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2007-01-01

     Introduction: Replacement of extensive local bone loss especially in revision joint arthroplasties is a significant clinical challenge. Autogenous and allogenic cancellous bone grafts have been the gold standard in reconstructive orthopaedic surgery, but it is well known that there is morbidity...... to be sought. Hydroxyapatite and collagen composites have the potential in mimicking and replacing skeletal bones. Aim: This study attempted to determine the effect of hydroxyapatite/collagen composites in the fixation of bone implants. The composites used in this study is produced by Institute of Science...... part of the implant. Specimens are preserving now at - 20°C and wait for the push-out test which is destructive and will be performed on an 858 Bionex MTS hydraulic material testing machine (MTS system cooperation, Minneapolis, Minnesota, USA). The specimens for histological analysis were taken from...

  19. Age-related changes in collagen properties and mineralization in cancellous and cortical bone in the porcine mandibular condyle

    NARCIS (Netherlands)

    Willems, N.M.B.K.; Langenbach, G.E.J.; Everts, V.; Mulder, L.; Grünheid, T.; Bank, R.A.; Zentner, A.; Eijden, T.M.G.J. van

    2010-01-01

    Collagen is an important constituent of bone, and it has been suggested that changes in collagen and mineral properties of bone are interrelated during growth. The aim of this study was to quantify age-related changes in collagen properties and the degree of mineralization of bone (DMB). The DMB in

  20. Testing sequential extraction methods for the analysis of multiple stable isotope systems from a bone sample

    Science.gov (United States)

    Sahlstedt, Elina; Arppe, Laura

    2017-04-01

    Stable isotope composition of bones, analysed either from the mineral phase (hydroxyapatite) or from the organic phase (mainly collagen) carry important climatological and ecological information and are therefore widely used in paleontological and archaeological research. For the analysis of the stable isotope compositions, both of the phases, hydroxyapatite and collagen, have their more or less well established separation and analytical techniques. Recent development in IRMS and wet chemical extraction methods have facilitated the analysis of very small bone fractions (500 μg or less starting material) for PO43-O isotope composition. However, the uniqueness and (pre-) historical value of each archaeological and paleontological finding lead to preciously little material available for stable isotope analyses, encouraging further development of microanalytical methods for the use of stable isotope analyses. Here we present the first results in developing extraction methods for combining collagen C- and N-isotope analyses to PO43-O-isotope analyses from a single bone sample fraction. We tested sequential extraction starting with dilute acid demineralization and collection of both collagen and PO43-fractions, followed by further purification step by H2O2 (PO43-fraction). First results show that bone sample separates as small as 2 mg may be analysed for their δ15N, δ13C and δ18OPO4 values. The method may be incorporated in detailed investigation of sequentially developing skeletal material such as teeth, potentially allowing for the investigation of interannual variability in climatological/environmental signals or investigation of the early life history of an individual.

  1. Nonenzymatic cross-linking pentosidine increase in bone collagen and are associated with disorders of bone mineralization in dialysis patients.

    Science.gov (United States)

    Mitome, Jun; Yamamoto, Hiroyasu; Saito, Mitsuru; Yokoyama, Keitaro; Marumo, Keishi; Hosoya, Tatsuo

    2011-06-01

    Disorders of bone and mineral metabolism are common complications in chronic kidney disease (CKD) patients and lead to significantly increased fracture risk, morbidity, and mortality of cardiovascular disease due to ectopic calcifications, contributing to a worsening prognosis. Bone strength is determined by not only bone mineral density but also bone quality, which is dependent on bone collagen cross-links. Collagen cross-links are classified into enzymatic immature and mature types and nonenzymatic advanced glycation end products (AGEs). Pentosidine is well established as one of the AGEs that accumulates markedly in CKD patients. The chemistry, function, and clinical relevance of cross-links have been revealed, whereas bone quality and the relationship with bone mineralization in CKD patients are not clear. We performed transiliac bone biopsies on 22 dialysis patients (mean age 56 ± 9 years) with severe secondary hyperparathyroidism and measured cross-links by evaluating bone histomorphometry. Cross-links data were compared with age-matched non-CKD subjects (mean age 58 ± 8 years, n = 17). Enzymatic collagen cross-links were formed to a similar extent compared with non-CKD subjects and showed a positive correlation with plasma intact parathyroid hormone. Pentosidine was remarkably increased in dialysis patients and inversely correlated with bone-formation rate/bone volume and mineral apposition rate. This study suggests that AGE collagen cross-links strongly associate with disorders of bone metabolism in dialysis patients.

  2. Bone Collagen: New Clues to its Mineralization Mechanism From Recessive Osteogenesis Imperfecta

    Science.gov (United States)

    Eyre, David R.; Ann Weis, Mary

    2013-01-01

    Until 2006 the only mutations known to cause osteogenesis imperfecta (OI) were in the two genes coding for type I collagen chains. These dominant mutations affecting the expression or primary sequence of collagen α1(I) and α2(I) chains account for over 90% of OI cases. Since then a growing list of mutant genes causing the 5–10% of recessive cases has rapidly emerged. They include CRTAP, LEPRE1 and PPIB, which encode three proteins forming the prolyl 3-hydroxylase complex; PLOD2 and FKBP10, which encode respectively lysyl hydroxylase 2 and a foldase required for its activity in forming mature cross-links in bone collagen; SERPIN H1, which encodes the collagen chaperone HSP47; SERPIN F1, which encodes pigment epithelium-derived factor required for osteoid mineralization; and BMP1, which encodes the type I procollagen C-propeptidase. All cause fragile bone in infancy, which can include over-mineralization or under-mineralization defects as well as abnormal collagen post-translational modifications. Consistently both dominant and recessive variants lead to abnormal cross-linking chemistry in bone collagen. These recent discoveries strengthen the potential for a common pathogenic mechanism of misassembled collagen fibrils. Of the new genes identified, eight encode proteins required for collagen post-translational modification, chaperoning of newly synthesized collagen chains into native molecules or transport through the endoplasmic reticulum and Golgi for polymerization, cross-linking and mineralization. In reviewing these findings, we conclude that a common theme is emerging in the pathogenesis of brittle bone disease of mishandled collagen assembly with important insights on post-translational features of bone collagen that have evolved to optimize it as a biomineral template. PMID:23508630

  3. The bone tissue responses to prehydrated and collagenated cortico-cancellous porcine bone grafts: a study in rabbit maxillary defects.

    Science.gov (United States)

    Nannmark, Ulf; Sennerby, Lars

    2008-12-01

    Bone substitutes should have osteoconductive properties and be completely replaced with new bone with time. Adding collagen gel to prehydrated and collagenated porcine bone (PCPB) particles results in a sticky and moldable material which facilitates clinical handling. However, the possible influence of the gel on the bone tissue response is not known. The objective of the study was to evaluate the bone tissue responses to PCPB graft with or without collagen gel and to evaluate the resorption/degradation properties of the biomaterials. Fourteen rabbits were used in the study. Bilateral bone defects, 5 x 8 x 3 mm, were created in the maxilla and filled with PCPB + collagen gel (test) or with PCPB only (control) and covered with a collagen membrane. Animals were killed after 2 (n = 3), 4 (n = 3), and 8 weeks (n = 8) for histological and morphometrical evaluations. There were no differences between test and control defects. Both materials showed bone formation directly on the particles by typical osteoblastic seams. The bone area increased with time (2-8 weeks) for both sides, from 16.2% (control) and 19.2% (test) to 42.7 and 43.8%, respectively. The PCPB, whether mixed with collagen gel or not, was resorbed by osteoclasts as well as part of remodeling with the formation of osteons within the particles. Morphometry showed a decrease of PCPB area from 19.4% (control) and 23.8% (test) after 2 weeks to 3.7 and 9.3% after 8 weeks, respectively. Mixing collagen gel and PCPB to facilitate the clinical handling does not influence the bone tissue responses to the material, which exhibited osteoconductive properties and was resorbed with time.

  4. Use of a collagen membrane loaded with recombinant human bone morphogenetic protein-2 with collagen-binding domain for vertical guided bone regeneration.

    Science.gov (United States)

    Lai, Chun-Hua; Zhou, Lei; Wang, Zhong-Lei; Lu, Hai-Bin; Gao, Yan

    2013-07-01

    Vertical bone regeneration of severe atrophic alveolar ridges remains a challenging procedure in implant dentistry. The aim of this study, accordingly, is to use a rabbit vertical guided bone regeneration model to evaluate whether using a collagen membrane (CM) loaded with small doses of recombinant human bone morphogenetic protein-2 with collagen-binding domain (rhBMP-2/CBD) would enhance two-way vertical bone regeneration. In each of eight rabbits, four titanium cylinders were screwed in perforated slits made into the external cortical bones of the calvaria. The following four treatment modalities were randomly allocated: 1) cylinders filled with mineralized bone matrix and covered with CM/rhBMP-2/CBD; 2) cylinders filled with mineralized bone matrix and covered with CM/rhBMP-2; 3) cylinders filled with mineralized bone matrix and covered with CM alone; or 4) cylinders filled with mineralized bone matrix without a membrane cover. After 6 weeks, the new bones were examined by histologic analysis. Slender new bone trabeculae were observed in the superficial layer of the titanium cylinders covered with CM/rhBMP-2/CBD, and higher degrees of bone were observed in this group compared with the other three groups. The average area fraction of newly formed bone was significantly more in the CM/rhBMP-2/CBD group compared with the CM/rhBMP-2, CM, or the no membrane control groups (all P bone formation not only from the surface of the native bone, but also from the superficial structures. The augmented new bone, therefore, is improved in both quantity and quality.

  5. Organization and quantification of the collagen fibers in bone formation during orthodontic tooth movement.

    Science.gov (United States)

    Retamoso, Luciana Borges; da Cunha, Taís De Morais Alves; Knop, Luégya Amorin Henriques; Shintcovsk, Ricardo Lima; Tanaka, Orlando Motohiro

    2009-12-01

    The organic matrix of alveolar bone is composed fundamentally of type I collagen. Polarized light microscopy provides unique information about the structure, composition and polymerization degree of a variety of organic and inorganic tissues that is not available with other techniques. The aim of this research was to compare two methodologies of polarized light analysis for collagen organization in bone formation during orthodontic tooth movement and determined maturity of collagen over the time. Thirty Wistar rats were euthanized 3, 7 and 14 days after the NiTi unilateral closed-coil spring was stretched between the upper right first molar and the incisors. The control consisted by contra-lateral site. The first molar area was fixed, decalcified and histologically processed using picrosirius pigment. The collagen birefringence of bone turnover was analyzed by color percentage and phase retardation. We observed an increase in collagen fiber organization over time with two methodologies. The Pearson coefficient correlation indicated a strong relationship (0.76) among the two polarized light analyses. In summary, there is collagen maturation over 3, 7 and 14 days. We successfully evaluated the molecular organization, arrangement, degree of polymerization and maturation process of collagen fibers in bone turnover through color percentages and phase retardation.

  6. Preparation and structure characterization of soluble bone collagen ...

    African Journals Online (AJOL)

    In this study, G-25 gel chromatography, X-diffraction, scanning electron microscopy (SEM), UV and Fourier transform infrared spectroscopy (FTIR) were used to analyze soluble collagen peptides chelating calcium. Collagen peptide hydrolysis can be divided into four components using G-25 gel chromatography.

  7. The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

      The effect of Hydroxyapatite/collagen I composites, bone marrow aspirate and bone graft on fixation of bone implants IN SHEEP   Ph.D. Student, Hassan Babiker; Associate Professor, Ph.D. Ming Ding; Professor, dr.med., Soren Overgaard. Department of Orthopaedic Surgery, Odense University Hospital......, Odense, Denmark   Background: Hydroxyapatite and collagen composites (HA/coll) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effect of newly developed HA/coll-composites with and without bone marrow aspirate (BMA) in order to enhance the fixation...

  8. In Vitro and In Vivo Study of a Novel Porcine Collagen Membrane for Guided Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Eisner Salamanca

    2016-11-01

    Full Text Available For years, in order to improve bone regeneration and prevent the need of a second stage surgery to remove non-resorbable membranes, biological absorbable membranes have gradually been developed and applied in guided tissue regeneration (GTR. The present study’s main objective was to achieve space maintenance and bone regeneration using a new freeze-dried developed porcine collagen membrane, and compare it with an already commercial collagen membrane, when both were used with a bovine xenograft in prepared alveolar ridge bone defects. Prior to surgery, the membrane’s vitality analysis showed statistically significant higher cell proliferation in the test membrane over the commercial one. In six beagle dogs, commercial bone xenograft was packed in lateral ridge bone defects prepared in the left and right side and then covered with test porcine collagen membrane or commercial collagen membrane. Alveolar height changes were measured. Histomorphometric results, in vitro and in vivo properties indicated that the new porcine collagen membrane is biocompatible, enhances bone xenograft osteoconduction, and reduces the alveolar ridge height reabsorption rate.

  9. Optimizing Collagen Scaffolds for Bone Engineering: Effects of Cross-linking and Mineral Content on Structural Contraction and Osteogenesis.

    Science.gov (United States)

    Lee, Justine C; Pereira, Clifford T; Ren, Xiaoyan; Huang, Weibiao; Bischoff, David; Weisgerber, Daniel W; Yamaguchi, Dean T; Harley, Brendan A; Miller, Timothy A

    2015-09-01

    Osseous defects of the craniofacial skeleton occur frequently in congenital, posttraumatic, and postoncologic deformities. The field of scaffold-based bone engineering emerged to address the limitations of using autologous bone for reconstruction of such circumstances. In this work, the authors evaluate 2 modifications of three-dimensional collagen-glycosaminoglycan scaffolds in an effort to optimize structural integrity and osteogenic induction. Human mesenchymal stem cells (hMSCs) were cultured in osteogenic media on nonmineralized collagen-glycosaminoglycan (C-GAG) and nanoparticulate mineralized collagen-glycosaminoglycan (MC-GAG) type I scaffolds, in the absence and presence of cross-linking. At 1, 7, and 14 days, mRNA expression was analyzed using quantitative real-time -reverse-transcriptase polymerase chain reaction for osteocalcin (OCN) and bone sialoprotein (BSP). Structural contraction was measured by the ability of the scaffolds to maintain their original dimensions. Mineralization was detected by microcomputed tomographic (micro-CT) imaging at 8 weeks. Statistical analyses were performed with Student t-test. Nanoparticulate mineralization of collagen-glycosaminoglycan scaffolds increased expression of both OCN and BSP. Cross-linking of both C-GAG and MC-GAG resulted in decreased osteogenic gene expression; however, structural contraction was significantly decreased after cross-linking. Human mesenchymal stem cells-directed mineralization, detected by micro-CT, was increased in nanoparticulate mineralized scaffolds, although the density of mineralization was decreased in the presence of cross-linking. Optimization of scaffold material is an essential component of moving toward clinically translatable engineered bone. Our current study demonstrates that the combination of nanoparticulate mineralization and chemical cross-linking of C-GAG scaffolds generates a highly osteogenic and structurally stable scaffold.

  10. Development of a nanofiltration method for bone collagen {sup 14}C AMS dating

    Energy Technology Data Exchange (ETDEWEB)

    Boudin, Mathieu, E-mail: mathieu.boudin@ugent.be [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium); Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Boeckx, Pascal [Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Buekenhoudt, Anita [Flemish Institute for Technological Research, Separation and Conversion Technology, Boeretang 200, B-2400 Mol (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Van Strydonck, Mark [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium)

    2013-01-15

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased {sup 14}C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) {approx}100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. {sup 14}C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant

  11. Analysis of collagen preservation in bones recovered in archaeological contexts using NIR Hyperspectral Imaging.

    Science.gov (United States)

    Vincke, Damien; Miller, Rebecca; Stassart, Édith; Otte, Marcel; Dardenne, Pierre; Collins, Matthew; Wilkinson, Keith; Stewart, John; Baeten, Vincent; Fernández Pierna, Juan Antonio

    2014-07-01

    The scope of this article is to propose an innovative method based on Near Infrared Hyperspectral Chemical Imaging (NIR-HCI) to rapidly and non-destructively evaluate the relative degree of collagen preservation in bones recovered from archaeological contexts. This preliminary study has allowed the evaluation of the potential of the method using bone samples from the Early Upper Palaeolithic, Mesolithic and Neolithic periods at the site of Trou Al'Wesse in Belgium. NIR-HCI, combined with chemometric tools, has identified specific spectral bands characteristic of collagen. A chemometric model has been built using Partial Least Squares Discriminant Analysis (PLS-DA) to identify bones with and without collagen. This enables the evaluation of the degree of collagen preservation and homogeneity in bones within and between different strata, which has direct implications for archaeological applications (e.g., taphonomic analyses, assemblage integrity) and sample selection for subsequent analyses requiring collagen. Two archaeological applications are presented: comparison between sub-layers in an Early Upper Palaeolithic unit, and evaluation of the range of variability in collagen preservation within a single Holocene stratum. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Fabrication of polycaprolactone collagen hydrogel constructs seeded with mesenchymal stem cells for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, J C; Berner, A [Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane (Australia); Heymer, A; Eulert, J; Noeth, U, E-mail: johannes.reichert@qut.edu.a [Orthopaedic Institute, Division of Tissue Engineering, Koenig-Ludwig-Haus, Julius-Maximilians-University, Wuerzburg (Germany)

    2009-12-15

    The osteogenic differentiation of bone marrow-derived human mesenchymal stem cells (MSCs) in a collagen I hydrogel was investigated. Collagen hydrogels with 7.5 x 10{sup 5} MSCs ml{sup -1} were fabricated and cultured for 6 weeks in a defined, osteogenic differentiation medium. Histochemistry revealed morphologically distinct, chondrocyte-like cells, surrounded by a sulfated proteoglycan-rich extracellular matrix in the group treated with bone morphogenetic protein 2 (BMP-2), while cells cultured with dexamethasone, ascorbate-2-phosphate, and beta-glycerophosphate displayed a spindle-shaped morphology and deposited a mineralized matrix. Real-time polymerase chain reaction (RT-PCR) analyses revealed a specific chondrogenic differentiation with the expression of cartilage-specific markers in the BMP-2-treated group and a distinct expression pattern of the osteogenic markers alkaline phosphatase (ALP), type I collagen, osteocalcin (OC), and cbfa-1 in the group treated with an osteogenic standard medium. The collagen gels were used to engineer a cell laden medical grade epsilon-polycaprolactone (PCL)-hydrogel construct for segmental bone repair showing good bonding at the scaffold hydrogel interface and even cell distribution. The results show that MSCs cultured in a collagen I hydrogel are able to undergo a distinct osteogenic differentiation pathway when stimulated with specific differentiation factors and suggest that collagen I hydrogels are a suitable means to facilitate cell seeding of scaffolds for bone tissue engineering applications.

  13. Accelerated craniofacial bone regeneration through dense collagen gel scaffolds seeded with dental pulp stem cells

    Science.gov (United States)

    Chamieh, Frédéric; Collignon, Anne-Margaux; Coyac, Benjamin R.; Lesieur, Julie; Ribes, Sandy; Sadoine, Jérémy; Llorens, Annie; Nicoletti, Antonino; Letourneur, Didier; Colombier, Marie-Laure; Nazhat, Showan N.; Bouchard, Philippe; Chaussain, Catherine; Rochefort, Gael Y.

    2016-12-01

    Therapies using mesenchymal stem cell (MSC) seeded scaffolds may be applicable to various fields of regenerative medicine, including craniomaxillofacial surgery. Plastic compression of collagen scaffolds seeded with MSC has been shown to enhance the osteogenic differentiation of MSC as it increases the collagen fibrillary density. The aim of the present study was to evaluate the osteogenic effects of dense collagen gel scaffolds seeded with mesenchymal dental pulp stem cells (DPSC) on bone regeneration in a rat critical-size calvarial defect model. Two symmetrical full-thickness defects were created (5 mm diameter) and filled with either a rat DPSC-containing dense collagen gel scaffold (n = 15), or an acellular scaffold (n = 15). Animals were imaged in vivo by microcomputer tomography (Micro-CT) once a week during 5 weeks, whereas some animals were sacrificed each week for histology and histomorphometry analysis. Bone mineral density and bone micro-architectural parameters were significantly increased when DPSC-seeded scaffolds were used. Histological and histomorphometrical data also revealed significant increases in fibrous connective and mineralized tissue volume when DPSC-seeded scaffolds were used, associated with expression of type I collagen, osteoblast-associated alkaline phosphatase and osteoclastic-related tartrate-resistant acid phosphatase. Results demonstrate the potential of DPSC-loaded-dense collagen gel scaffolds to benefit of bone healing process.

  14. Collagen barrier membranes adsorb growth factors liberated from autogenous bone chips.

    Science.gov (United States)

    Caballé-Serrano, Jordi; Sawada, Kosaku; Miron, Richard J; Bosshardt, Dieter D; Buser, Daniel; Gruber, Reinhard

    2017-02-01

    Collagen membranes serve as barriers to separate bone grafts from soft tissues. Bone grafts harvested with a bone scraper release growth factors activating transforming growth factor-β (TGF-β) signaling in mesenchymal cells. The aim of the present pilot study was to determine whether collagen membranes adsorb molecules from bone-conditioned medium (BCM) with the capacity to provoke the expression of TGF-β target genes in vitro. Collagen membranes were soaked in aqueous extracts from fresh and demineralized bone chips placed in cell culture medium. Recombinant human TGF-β1 served as control. Gingival fibroblasts were seeded onto the washed collagen membranes and evaluated for the expression of adrenomedullin, pentraxin 3, interleukin 11, and proteoglycan 4. Cell viability and morphology with phalloidin staining were also determined. Incubation of collagen membranes with BCM for at least one minute caused fibroblasts to decrease the expression of adrenomedullin and pentraxin 3, and to increase the expression of interleukin 11 and proteoglycan 4. Four different membrane treatments - incubated with recombinant TGF-β1, pre-wetted with saline solution, exposed to UV light, and dry out and stored one week at room temperature - also provoked significant changes in gene expression. Likewise, conditioned medium from demineralized bone chips caused gene expression changes. BCM did not alter the viability or morphology of gingival fibroblasts. These findings demonstrate that collagen membranes rapidly adsorb the TGF-β activity released from bone chips, a molecular process that might contribute to guided bone regeneration. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl C; Overgaard, Søren

    2010-01-01

    The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone – Validation of large animal model for tissue engineering and biomaterial research Ming Ding,1* Carl Christian Danielsen,2 Søren Overgaard1 1Orthopaedic Research Laboratory...... by glucocorticoid treatment and the changes in properties of cancellous bone were comparable with those observed in humans after long-term glucocorticoid treatment. However, the influence on cortical bone has not been thoroughly elucidated. This study aimed to investigate the influence of glucocorticoid on sheep...... cortical bone after long-term treatment. Specifically, we quantify the microarchitecture, mechanical properties, collagen and mineral quality of sheep cortical bone. We hypothesized that glucocorticoid treatment also had significant influences on cortical bone that might increase risk of fracture...

  16. Techniques to assess bone ultrastructure organization: orientation and arrangement of mineralized collagen fibrils

    Science.gov (United States)

    Georgiadis, Marios; Müller, Ralph; Schneider, Philipp

    2016-01-01

    Bone's remarkable mechanical properties are a result of its hierarchical structure. The mineralized collagen fibrils, made up of collagen fibrils and crystal platelets, are bone's building blocks at an ultrastructural level. The organization of bone's ultrastructure with respect to the orientation and arrangement of mineralized collagen fibrils has been the matter of numerous studies based on a variety of imaging techniques in the past decades. These techniques either exploit physical principles, such as polarization, diffraction or scattering to examine bone ultrastructure orientation and arrangement, or directly image the fibrils at the sub-micrometre scale. They make use of diverse probes such as visible light, X-rays and electrons at different scales, from centimetres down to nanometres. They allow imaging of bone sections or surfaces in two dimensions or investigating bone tissue truly in three dimensions, in vivo or ex vivo, and sometimes in combination with in situ mechanical experiments. The purpose of this review is to summarize and discuss this broad range of imaging techniques and the different modalities of their use, in order to discuss their advantages and limitations for the assessment of bone ultrastructure organization with respect to the orientation and arrangement of mineralized collagen fibrils. PMID:27335222

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-01

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

  18. Pitfalls in comparing modern hair and fossil bone collagen C and N isotopic data to reconstruct ancient diets: a case study with cave bears (Ursus spelaeus).

    Science.gov (United States)

    Bocherens, Hervé; Grandal-d'Anglade, Aurora; Hobson, Keith A

    2014-01-01

    Stable isotope analyses provide one of the few means to evaluate diet of extinct taxa. However, interpreting isotope data from bone collagen of extinct animals based on isotopic patterns in different tissues of modern animal proxies is precarious. For example, three corrections are needed before making comparisons of recent hair and ancient bone collagen: calibration of carbon-13 variations in atmospheric CO2, different isotopic discrimination between diet-hair keratin and diet-bone collagen, and time averaging of bone collagen versus short-term record in hair keratin. Recently, Robu et al. [Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus). Can J Zool. 2013;91:227-234] published an article comparing extant carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopic data of European cave bear bone collagen with those of Yellowstone Park grizzly bear hair in order to test the prevailing assumption of a largely vegetarian diet among cave bears. The authors concluded that cave bears were carnivores. This work is unfortunately unfounded as the authors failed to consider the necessary corrections listed above. When these corrections are applied to the Romanian cave bears, these individuals can be then interpreted without involving consumption of high trophic-level food, and environmental changes are probably the reason for the unusual isotopic composition of these cave bears in comparison with other European cave bears, rather than a change of diet. We caution researchers to pay careful attention to these factors when interpreting feeding ecology of extinct fauna using stable isotope techniques.

  19. Immunohistochemical detection of interstitial collagens in bone and cartilage tissue remnants in an infant Peruvian mummy.

    Science.gov (United States)

    Nerlich, A G; Parsche, F; Kirsch, T; Wiest, I; von der Mark, K

    1993-07-01

    We investigated the immunohistochemical presence of various collagen types in bone and cartilage tissue from an infant Peruvian mummy dating between 500 and 1000 A.D. which had been excavated at the necropolis of Las Trancas in the Nazca region in Peru. Following careful rehydration and decalcification of the tissue, the mummy tissue showed morphologically good preservation of the matrix, which could be shown to be composed of various collagen types in a typical pattern. Bone consisted of a collagen I matrix with a small rim of collagen III and V at the endosteal lining and a pericellular collagen V staining around osteocytic holes. In the hypertrophic cartilage of the epiphyseal growth plate, a typical pattern of collagen types II and X could be found. These observations provide evidence that in well-preserved mummy tissue the antigenic determinants of major matrix components are still adequately preserved for an immunohistochemical analysis. This technique may thus be a very helpful tool for the analysis of pathologic processes of historic bone tissue. It may also allow in certain circumstances a distinction between pseudopathologic tissue destruction and pathologic tissue alteration.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  1. Kinetics of gene expression and bone remodelling in the clinical phase of collagen induced arthritis

    DEFF Research Database (Denmark)

    Denninger, Katja Caroline Marie; Litman, Thomas; Marstrand, Troels

    2015-01-01

    Introduction: Pathological bone changes differ considerably between inflammatory arthritic diseases and most studies have focused on bone erosion. Collagen-induced arthritis (CIA) is a model for rheumatoid arthritis, which, in addition to bone erosion, demonstrates bone formation at the time...... of clinical manifestations. The objective of this study was to use this model to characterise the histological and molecular changes in bone remodelling, and relate these to the clinical disease development. Methods: A histological and gene expression profiling time-course study on bone remodelling in CIA......), and secreted phosphoprotein 1 (Spp1). Pregnancy-associated protein A (Pappa) and periostin (Postn), differentially expressed in the early disease phase, are proposed to participate in bone formation, and we suggest that they play a role in early bone formation in the CIA model. Comparison to human genome...

  2. Guided Bone Regeneration Using Collagen Scaffolds, Growth Factors, and Periodontal Ligament Stem Cells for Treatment of Peri-Implant Bone Defects In Vivo

    Directory of Open Access Journals (Sweden)

    Peer W. Kämmerer

    2017-01-01

    Full Text Available Introduction. The aim of the study was an evaluation of different approaches for guided bone regeneration (GBR of peri-implant defects in an in vivo animal model. Materials and Methods. In minipigs (n=15, peri-implant defects around calcium phosphate- (CaP-; n=46 coated implants were created and randomly filled with (1 blank, (2 collagen/hydroxylapatite/β-tricalcium phosphate scaffold (CHT, (3 CHT + growth factor cocktail (GFC, (4 jellyfish collagen matrix, (5 jellyfish collagen matrix + GFC, (6 collagen powder, and (7 collagen powder + periodontal ligament stem cells (PDLSC. Additional collagen membranes were used for coverage of the defects. After 120 days of healing, bone growth was evaluated histologically (bone to implant contact (BIC;%, vertical bone apposition (VBA; mm, and new bone height (NBH; %. Results. In all groups, new bone formation was seen. Though, when compared to the blank group, no significant differences were detected for all parameters. BIC and NBH in the group with collagen matrix as well as the group with the collagen matrix + GFC were significantly less when compared to the collagen powder group (all: p<0.003. Conclusion. GBR procedures, in combination with CaP-coated implants, will lead to an enhancement of peri-implant bone growth. There was no additional significant enhancement of osseous regeneration when using GFC or PDLSC.

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

    Science.gov (United States)

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

    2004-09-01

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

  4. Novel Vanadium-Loaded Ordered Collagen Scaffold Promotes Osteochondral Differentiation of Bone Marrow Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Ana M. Cortizo

    2016-01-01

    Full Text Available Bone and cartilage regeneration can be improved by designing a functionalized biomaterial that includes bioactive drugs in a biocompatible and biodegradable scaffold. Based on our previous studies, we designed a vanadium-loaded collagen scaffold for osteochondral tissue engineering. Collagen-vanadium loaded scaffolds were characterized by SEM, FTIR, and permeability studies. Rat bone marrow progenitor cells were plated on collagen or vanadium-loaded membranes to evaluate differences in cell attachment, growth and osteogenic or chondrocytic differentiation. The potential cytotoxicity of the scaffolds was assessed by the MTT assay and by evaluation of morphological changes in cultured RAW 264.7 macrophages. Our results show that loading of VOAsc did not alter the grooved ordered structure of the collagen membrane although it increased membrane permeability, suggesting a more open structure. The VOAsc was released to the media, suggesting diffusion-controlled drug release. Vanadium-loaded membranes proved to be a better substratum than C0 for all evaluated aspects of BMPC biocompatibility (adhesion, growth, and osteoblastic and chondrocytic differentiation. In addition, there was no detectable effect of collagen or vanadium-loaded scaffolds on macrophage viability or cytotoxicity. Based on these findings, we have developed a new ordered collagen scaffold loaded with VOAsc that shows potential for osteochondral tissue engineering.

  5. In vitro deposition of hydroxyapatite on cortical bone collagen stimulated by deformation-induced piezoelectricity.

    Science.gov (United States)

    Noris-Suárez, Karem; Lira-Olivares, Joaquin; Ferreira, Ana Marina; Feijoo, José Luis; Suárez, Nery; Hernández, Maria C; Barrios, Esteban

    2007-03-01

    In the present work, we have studied the effect of the piezoelectricity of elastically deformed cortical bone collagen on surface using a biomimetic approach. The mineralization process induced as a consequence of the piezoelectricity effect was evaluated using scanning electron microscopy (SEM), thermally stimulated depolarization current (TSDC), and differential scanning calorimetry (DSC). SEM micrographs showed that mineralization occurred predominantly over the compressed side of bone collagen, due to the effect of piezoelectricity, when the sample was immersed in the simulated body fluid (SBF) in a cell-free system. The TSDC method was used to examine the complex collagen dielectric response. The dielectric spectra of deformed and undeformed collagen samples with different hydration levels were compared and correlated with the mineralization process followed by SEM. The dielectric measurements showed that the mineralization induced significant changes in the dielectric spectra of the deformed sample. DSC and TSDC results demonstrated a reduction of the collagen glass transition as the mineralization process advanced. The combined use of SEM, TSDC, and DSC showed that, even without osteoblasts present, the piezoelectric dipoles produced by deformed collagen can produce the precipitation of hydroxyapatite by electrochemical means, without a catalytic converter as occurs in classical biomimetic deposition.

  6. A new procedure for extraction of collagen from modern and archaeological bones for 14C dating.

    Science.gov (United States)

    Maspero, F; Sala, S; Fedi, M E; Martini, M; Papagni, A

    2011-10-01

    Bones are potentially the best age indicators in a stratigraphic study, because they are closely related to the layer in which they are found. Collagen is the most suitable fraction and is the material normally used in radiocarbon dating. Bone contaminants can strongly alter the carbon isotopic fraction values of the samples, so chemical pretreatment for (14)C dating by accelerator mass spectrometry (AMS) is essential. The most widespread method for collagen extraction is based on the Longin procedure, which consists in HCl demineralization to dissolve the inorganic phase of the samples, followed by dissolution of collagen in a weak acid solution. In this work the possible side effects of this procedure on a modern bone are presented; the extracted collagen was analyzed by ATR-IR spectroscopy. An alternative procedure, based on use of HF instead of HCl, to minimize unwanted degradation of the organic fraction, is also given. A study by ATR-IR spectroscopic analysis of collagen collected after different demineralization times and with different acid volumes, and a study of an archaeological sample, are also presented.

  7. Effect of Orally Administered Collagen Peptides from Bovine Bone on Skin Aging in Chronologically Aged Mice

    Directory of Open Access Journals (Sweden)

    Hongdong Song

    2017-11-01

    Full Text Available Collagen peptides (CPs have demonstrated to exert beneficial effects on skin photoaging. However, little has been done to evaluate their effects on chronologically aged skin. Here, the effects of CPs from bovine bone on skin aging were investigated in chronologically aged mice. 13-month-old female Kunming mice were administered with CPs from bovine bone (200, 400 and 800 mg/kg body weight/day or proline (400 mg/kg body weight/day for 8 weeks. Mice body weight, spleen index (SI and thymus index (TI, degree of skin laxity (DSL, skin components, skin histology and antioxidant indicators were analyzed. Ingestion of CPs or proline had no effect on mice skin moisture and hyaluronic acid content, but it significantly improved the skin laxity, repaired collagen fibers, increased collagen content and normalized the ratio of type I to type III collagen in chronologically aged skin. CPs prepared by Alcalase performed better than CPs prepared by collagenase. Furthermore, CPs intake also significantly improved the antioxidative enzyme activities in skin. These results indicate that oral administration of CPs from bovine bone or proline can improve the laxity of chronologically aged skin by changing skin collagen quantitatively and qualitatively, and highlight their potential application as functional foods to combat skin aging in chronologically aged process.

  8. 3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration.

    Science.gov (United States)

    Inzana, Jason A; Olvera, Diana; Fuller, Seth M; Kelly, James P; Graeve, Olivia A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2014-04-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1-2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone.

    Directory of Open Access Journals (Sweden)

    Virginia L Harvey

    Full Text Available Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N and ratio of carbon to nitrogen (C:N. Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands, chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six (14C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae, recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP. All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated (14C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 1(4C analysis.

  10. Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone.

    Science.gov (United States)

    Harvey, Virginia L; Egerton, Victoria M; Chamberlain, Andrew T; Manning, Phillip L; Buckley, Michael

    2016-01-01

    Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N) and ratio of carbon to nitrogen (C:N). Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification) as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands), chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six (14)C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae), recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP). All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated (14)C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 1(4)C analysis.

  11. Thermal and electron stimulated luminescence of natural bones, commercial hydroxyapatite and collagen.

    Science.gov (United States)

    Roman-Lopez, J; Correcher, V; Garcia-Guinea, J; Rivera, T; Lozano, I B

    2014-01-01

    The luminescence (cathodoluminescence and thermoluminescence) properties of natural bones (Siberian mammoth and adult elephant), commercial hydroxyapatite and collagen were analyzed. Chemical analyses of the natural bones were determined using by Electron Probe Micro-Analysis (EMPA). Structural, molecular and thermal characteristics were determined by X-ray Diffraction (XRD), Raman spectroscopy and Differential Thermal and Thermogravimetric analysis (DTA-TG). Cathodoluminescence (CL) spectra of natural bones and collagen showed similar intense broad bands at 440 and 490 nm related to luminescence of the tetrahedral anion [Formula: see text] or structural defects. A weaker luminescence exhibited at 310 nm could be attributed to small amount of rare earth elements (REEs). Four luminescent bands at 378, 424, 468 and 576 nm were observed in the commercial hydroxyapatite (HAP). Both natural bones and collagen samples exhibited natural thermoluminescence (NTL) with well-defined glow curves whereas that the induced thermoluminescence (ITL) only appears in the samples of commercial hydroxyapatite and collagen. Additional explanations for the TL anomalous fading of apatite, as a crucial difficulty performing dosimetry and dating, are also considered. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Bioinspired nanocomposite structures for bone tissue regeneration based on collagen, gelatin, polyamide and hydroxyapatite

    Czech Academy of Sciences Publication Activity Database

    Suchý, Tomáš; Balík, Karel; Šupová, Monika; Hrušková, Daniela; Sucharda, Zbyněk; Černý, Martin; Sedláček, R.

    2009-01-01

    Roč. 12, 89-91 (2009), s. 13-15 ISSN 1429-7248 R&D Projects: GA ČR GA106/09/1000 Institutional research plan: CEZ:AV0Z30460519 Keywords : nanocomposite * bone regeneration * collagen Subject RIV: JI - Composite Materials

  13. Collagen immobilization of multi-layered BCP-ZrO2 bone substitutes to enhance bone formation

    Science.gov (United States)

    Linh, Nguyen Thuy Ba; Jang, Dong-Woo; Lee, Byong-Taek

    2015-08-01

    A porous microstructure of multi-layered BCP-ZrO2 bone substitutes was fabricated using the sponge replica method in which the highly interconnected structure was immobilized with collagen via ethyl(dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide crosslinking. Their struts are combined with a three-layered BCP/BCP-ZrO2/ZrO2 microstructure. Collagen fibers were firmly attached to the strut surface of the BCP-ZrO2 scaffolds. With control of the three-layered microstructure and collagen immobilization, the compressive strength of the scaffolds increased significantly to 6.8 MPa compared to that of the monolithic BCP scaffolds (1.3 MPa). An in vitro study using MTT, confocal observation, and real-time polymer chain reaction analysis demonstrated that the proliferation and differentiation of the pre-osteoblast-like MC3T3-E1 cells was improved due to the collagen incorporation. Remarkable enhancement of bone regeneration was observed without any immunological reaction in the femurs of rabbits during 1 and 5 months of implantation. Furthermore, the interfaces between new bone and the scaffold struts bonded directly without any gaps.

  14. A Novel HA/β-TCP-Collagen Composite Enhanced New Bone Formation for Dental Extraction Socket Preservation in Beagle Dogs

    Directory of Open Access Journals (Sweden)

    Ko-Ning Ho

    2016-03-01

    Full Text Available Past studies in humans have demonstrated horizontal and vertical bone loss after six months following tooth extraction. Many biomaterials have been developed to preserve bone volume after tooth extraction. Type I collagen serves as an excellent delivery system for growth factors and promotes angiogenesis. Calcium phosphate ceramics have also been investigated because their mineral chemistry resembles human bone. The aim of this study was to compare the performance of a novel bioresorbable purified fibrillar collagen and hydroxyapatite/β-tricalcium phosphate (HA/β-TCP ceramic composite versus collagen alone and a bovine xenograft-collagen composite in beagles. Collagen plugs, bovine graft-collagen composite and HA/β-TCP-collagen composite were implanted into the left and right first, second and third mandibular premolars, and the fourth molar was left empty for natural healing. In total, 20 male beagle dogs were used, and quantitative and histological analyses of the extraction ridge was done. The smallest width reduction was 19.09% ± 8.81% with the HA/β-TCP-collagen composite at Week 8, accompanied by new bone formation at Weeks 4 and 8. The HA/β-TCP-collagen composite performed well, as a new osteoconductive and biomimetic composite biomaterial, for socket bone preservation after tooth extraction.

  15. Preparation of collagen/hydroxyapatite/alendronate hybrid hydrogels as potential scaffolds for bone regeneration.

    Science.gov (United States)

    Ma, Xin; He, Zhiwei; Han, Fengxuan; Zhong, Zhiyuan; Chen, Liang; Li, Bin

    2016-07-01

    Development of biomimetic scaffolds represents a promising direction in bone tissue engineering. In this study, we designed a two-step process to prepare a type of biomimetic hybrid hydrogels that were composed of collagen, hydroxyapatite (HAP) and alendronate (ALN), an anti-osteoporosis drug. First, water-soluble ALN-conjugated HAP (HAP-ALN) containing 4.0wt.% of ALN was synthesized by treating HAP particles with ALN. Hydrogels were then formed from HAP-ALN conjugate and collagen under physiological conditions using genipin (GNP) as the crosslinker. Depending on the ALN/collagen molar ratio and GNP concentration, the gelation time of hydrogels ranged from 5 to 37min. Notably, these hybrid hydrogels exhibited markedly improved mechanical property (storage modulus G'=38-187kPa), higher gel contents, and lower swelling ratios compared to the hydrogels prepared from collagen alone under similar conditions. Moreover, they showed tunable degradation behaviors against collagenase. The collagen/HAP-ALN hybrid hydrogels supported the adhesion and growth of murine MC3T3-E1 osteoblastic cells well. Such tough yet enzymatically degradable hybrid hydrogels hold potential as scaffolds for bone tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Research of Bovine Bone Collagen/cellulose Nanofibers-nanohydroxyapatite Biological Composite

    Directory of Open Access Journals (Sweden)

    Jin Shenglang

    2016-01-01

    Full Text Available Different biomaterials have been used as scaffolds for bone tissue engineering. The purpose of the study was to analyze the effect of bovine bone collagen to the porosity, water retention, degradation rate and biomechanical characteristics of composite scaffolds. Methods: Bovine bone collagen solution was mixed with cellulose nanofibers solution, and then the mixture was added a certain quality of hydroxyapatite. We divided the mixture into two groups according to the different bovine bone collagen solution mass fraction: No.1 (0 % bovine bone collagen, No.2 (50 % bovine bone collagen. The surface structure and the pore size was observed under the Scanning electron microscopic. Then we calculated the porosity, degradation rate, water content and biomechanical properties. Results: Two groups of scaffold materials showed a multi-pore structure. The average pore size were 133.4 ±13.5 μm and 221.7 ± 16.8μm. The porosity was (91.65 ±1.75 % and (85.42 ±1.48 %. Statistical analysis showed that two groups of material porosity difference were statistically significant (P<0.05. The degradation rates of two groups of scaffold materials at six weeks were (60.25±1.81 % and (23.16±1.027 %. Statistical analysis showed that the degradation rate of the material differences between the two groups were statistically significant (P<0.05. Water content of two groups of scaffold materials was (97.44±0.98 % and (91.36±0.77 %. Statistical analysis showed that the water content of the material differences between the two groups were statistically significant (P<0.05. Biomechanical properties of the second group increased significantly. Conclusion: It could be seen from the experimental data that bovine bone collagen could increase the pore size, improved stability to degradation and the biomechanical strength of materials. Therefore, the biocomposite studied has several characteristics considered as ideal for its use as a scaffold for osteoconduction and

  17. Development and Characterization of a Bioinspired Bone Matrix with Aligned Nanocrystalline Hydroxyapatite on Collagen Nanofibers

    Directory of Open Access Journals (Sweden)

    Hsi-Chin Wu

    2016-03-01

    Full Text Available Various kinds of three-dimensional (3D scaffolds have been designed to mimic the biological spontaneous bone formation characteristics by providing a suitable microenvironment for osteogenesis. In view of this, a natural bone-liked composite scaffold, which was combined with inorganic (hydroxyapatite, Hap and organic (type I collagen, Col phases, has been developed through a self-assembly process. This 3D porous scaffold consisting of a c-axis of Hap nanocrystals (nHap aligning along Col fibrils arrangement is similar to natural bone architecture. A significant increase in mechanical strength and elastic modulus of nHap/Col scaffold is achieved through biomimetic mineralization process when compared with simple mixture of collagen and hydroxyapatite method. It is suggested that the self-organization of Hap and Col produced in vivo could also be achieved in vitro. The oriented nHap/Col composite not only possesses bone-like microstructure and adequate mechanical properties but also enhances the regeneration and reorganization abilities of bone tissue. These results demonstrated that biomimetic nHap/Col can be successfully reconstructed as a bone graft substitute in bone tissue engineering.

  18. Skin, bone and muscle collagen extraction from the trash fish, leather jacket (Odonus niger) and their characterization.

    Science.gov (United States)

    Muralidharan, Nagarajan; Jeya Shakila, Robinson; Sukumar, Durairaj; Jeyasekaran, G

    2013-12-01

    Acid soluble (ASC) and pepsin soluble (PSC) collagens were extracted from the skin, bone and muscle of a trash fish, leather jacket (Odonus niger) by three different extraction methods. Method I gave 46-50% yield for ASC, Method II gave 49-58% yield for both ASC and PSC and Method III gave 64-71% yield for PSC. The addition of pepsin had increased the yield by 30-45%. The yields of collagen from skin and bone were higher than muscle. SDS-PAGE pattern revealed that skin and bone collagen as Type I collagen with a typical (α1)2α2 chains and muscle collagen as Type V collagen with a typical α1α3α2 chains. Td values of bone and muscle collagen were high (30-32 °C) compared to skin collagen (27-28 °C). The higher imino acids (190 residues/1,000 residues) were found responsible for the higher Td values. The trash fish, leather jacket can therefore be exploited effectively for collagen as it has got good thermal properties for pharmaceutical and biomedical applications.

  19. Exercise and Regulation of Bone and Collagen Tissue Biology

    DEFF Research Database (Denmark)

    Kjær, Michael; Jørgensen, Niklas Rye; Heinemeier, Katja Maria

    2015-01-01

    The musculoskeletal system and its connective tissue include the intramuscular connective tissue, the myotendinous junction, the tendon, the joints with their cartilage and ligaments, and the bone; they all together play a crucial role in maintaining the architecture of the skeletal muscle...

  20. Collagen mutation causes changes of the microdamage morphology in bone of an OI mouse model.

    Science.gov (United States)

    Dong, X Neil; Zoghi, Mahyar; Ran, Qitao; Wang, Xiaodu

    2010-12-01

    Previous studies have postulated that ultrastructural changes may alter the pattern and capacity of microdamage accumulation in bone. Using an osteogenesis imperfecta (OI) mouse model, this study was performed to investigate the correlation of collagen mutation with the microdamage morphology and the associated brittleness of bone. In this study, femurs from mild OI and wild type mice were fatigued under four-point bending to create microdamage in the specimens. Then, the microdamage morphology of these specimens was examined using the bulk-staining technique with basic fuchsin. Similar with the results of previous studies, it was observed that linear microcracks were formed more easily in compression, whereas diffuse damage was induced more readily in tension for both wild-type and mild-type mice. However, less diffuse damage was found in the tensile side of mild OI mouse femurs (collagen mutation) compared with those of wild type mice, showing that the microdamage morphology is correlated to the brittleness of bone. The results of this study provide direct evidence that supports the prediction made by the previous numerical simulation studies, suggesting that microdamage morphology in bone is significantly correlated with the integrity of the collagen phase. Copyright © 2010 Elsevier Inc. All rights reserved.

  1. Piperine inhibit inflammation, alveolar bone loss and collagen fibers breakdown in a rat periodontitis model.

    Science.gov (United States)

    Dong, Y; Huihui, Z; Li, C

    2015-12-01

    Piperine exhibits anti-inflammatory activity, and has a long history of medicinal use. The objective of this study was to investigate the protective effects of piperine on inflammation, alveolar bone and collagen fibers in experimental periodontitis. We evaluated the related expression of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, matrix metalloproteinase (MMP)-8 and MMP-13 to enhance insight into these effects. Thirty-two Wistar rats were divided into four groups of eight animals each: control group, periodontitis group, periodontitis plus 50 mg/kg piperine group and periodontitis plus 100 mg/kg piperine group. Histopathologic changes were detected by hematoxylin and eosin staining. Alveolar bone loss and trabecula microstructures were evaluated by micro-computed tomography. Changes in collagen fibers were assessed by picrosirius red staining. Western blot analysis was conducted to determine the levels of IL-1β, TNF-α, MMP-8 and MMP-13. Piperine clearly inhibited alveolar bone loss and reformed trabecula microstructures in a dose-dependent manner. Histological staining showed that piperine significantly reduced the infiltration of inflammation in soft tissues. Both doses of piperine limited the fractions of degraded areas in collagen fibers. Piperine (100 mg/kg) significantly downregulated the expressions of IL-1β, MMP-8 and MMP-13 in periodontitis, but not that of TNF-α. Piperine displays significantly protective effects on inflammation, alveolar bone loss, bone microstructures and collagen fiber degradation in experimental periodontitis. The effects may be ascribed to its inhibitory activity on the expressions of IL-1β, MMP-8 and MMP-13. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Fabrication and in vitro evaluation of stable collagen/hyaluronic acid biomimetic multilayer on titanium coatings

    Science.gov (United States)

    Ao, Haiyong; Xie, Youtao; Tan, Honglue; Yang, Shengbing; Li, Kai; Wu, Xiaodong; Zheng, Xuebin; Tang, Tingting

    2013-01-01

    Layer-by-layer (LBL) self-assembly technique has been proved to be a highly effective method to immobilize the main components of the extracellular matrix such as collagen and hyaluronic acid on titanium-based implants and form a polyelectrolyte multilayer (PEM) film by electrostatic interaction. However, the formed PEM film is unstable in the physiological environment and affects the long-time effectiveness of PEM film. In this study, a modified LBL technology has been developed to fabricate a stable collagen/hyaluronic acid (Col/HA) PEM film on titanium coating (TC) by introducing covalent immobilization. Scanning electron microscopy, diffuse reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the PEM film. Results of Sirius red staining demonstrated that the chemical stability of PEM film was greatly improved by covalent cross-linking. Cell culture assays further illustrated that the functions of human mesenchymal stem cells, such as attachment, spreading, proliferation and differentiation, were obviously enhanced by the covalently immobilized Col/HA PEM on TCs compared with the absorbed Col/HA PEM. The improved stability and biological properties of the Col/HA PEM covalently immobilized TC may be beneficial to the early osseointegration of the implants. PMID:23635490

  3. LOX-related collagen crosslink changes act as an initiator of bone fragility in a ZDF rats model.

    Science.gov (United States)

    Xiao, Xun; Ren, Jie; Chen, Jun; Liu, Zhaohui; Tian, Ye; Nabar, Neel R; Wang, Min; Hao, Liang

    2018-01-01

    Diabetes mellitus type 2 (DM2) results in bone abnormalities that manifest as increased bone fragility. Bone consists of two phases, the mineral phase and the matrix phase, and disorders in both are seen in DM2. However, the phase in which DM2 mediated bone fragility is initiated is still unknown. In this study, a male Zucker diabetic fatty (fa/fa) (ZDF) rat model was used to investigate the underlying mechanism initiating DM2 mediated bone fragility. The fracture surface morphology, pre- and post-yield bone mechanical behavior, insoluble collagen volume, lysyl oxidase family (LOX) enzyme levels and correlation analysis was performed to determine the relationship between insoluble collagen and post-yield behavior. Four weeks after the induction of diabetes, insoluble collagen was decreased in only the matrix phase in diabetic rats. Consistently, mechanical testing of the bone showed changes only in post-yield behavior. Diabetic rats also had decreased levels of enzymes involved in insoluble collagen formation (LOX and LOXL1 families). Correlation analysis demonstrated that insoluble collagen was a positive regressor of post-yield displacement (R = 0.894, P < 0.001) and post-yield energy (R = 0.918, P < 0.001). Together, these findings suggest that bone fragility in DM2 is initiated in the matrix phase and that the LOX family may play a critical part in the pathogenesis of DM2 mediated bone fragility. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The potential of chitosan combined with chicken shank collagen as scaffold on bone defect regeneration process in Rattus norvegicus

    Directory of Open Access Journals (Sweden)

    Fitria Rahmitasari

    2016-12-01

    Full Text Available Background: In the field of dentistry, alveolar bone damage can be caused by periodontal disease, traumatic injury due to tooth extraction, cyst enucleation, and tumor surgery. One of the ways to regenerate the bone defect is using graft scaffold. Thus, combination of chitosan and collagen can stimulate osteogenesis. Purpose: The aim of this study was to examine the potential of chitosan combined with chicken shank collagen on bone defect regeneration process. Method: Twelve Rattus norvegicus were prepared as animal models in this research. A bone defect was intentionally created at both of the right and left femoral bones of the models. Next, 24 samples were divided into four groups, namely Group 1 using chitosan – collagen scaffold (50:50, Group 2 using chitosan collagen-scaffold (80:20, Group 3 using chitosan scaffold only, and Control Group using 3% CMC-Na. On 14th day, those animals were sacrificed, and histopathological anatomy examination was conducted to observe osteoclast cells. In addition, immunohistochemistry examination was also performed to observe RANKL expressions. Result: There was a significant difference in RANKL expressions among the groups, except between Group 3 using chitosan scaffold only and control group (p value > 0.05. The highest expression of RANKL was found in Group 1 with chitosan – collagen scaffold (50:50, followed by Group 2 with chitosan-collagen scaffold (80:20. Moreover, there was also a significant difference in osteoclast generation, except between Group 1 using chitosan – collagen scaffold (50:50 and Group 2 using chitosan-collagen scaffold (80:20, p value 0.05. Less osteoclast was found in the groups using chitosan – collagen scaffold (Group 1 and Group 2. Conclusion: Combination of chitosan and chicken shank collagen scaffold can improve regeneration process of bone defect in Rattus novergicus animals through increasing of RANKL expressions, and decreasing of osteoclast.

  5. Effect of nicotinamide on amino acids content in bone collagen depending on biological availability of vitamins in diabetic rats.

    Science.gov (United States)

    Guzyk, M M; Sergiichuk, Iu T; Dyakun, K O; Yanitska, L V; Kuchmerovska, T M

    2014-01-01

    Connective tissue is highly susceptible to imbalances induced by diabetes. Diabetes-related osteopenia, decreased bone strength etc. may be associated with altered metabolism of various collagens: Although it is assumed that alterations in collagen amino acids (AA) may strongly affect protein properties andphysiological functions, however, very limited evidences are present at the moment regarding AA composition of bone type I collagen and its relevance to abnormal availability of vitamins which are necessary for collagen synthesis in diabetes. We have tested whether nicotinamide (NAm) can influence type Icollagen formation and AA composition as well as vitamins availability in diabetes. After 4 weeks of STZ-induced diabetes (60 mg/ kg) male Wistar rats were injected for 2 weeks with/without NAm (200 mg/kg b. w). Acid extraction of type I collagen from the bones was performed with following stepwise salting out. The content of type I collagen after its acid extraction from the bones was estimated by the amounts of hydroxyproline. Amino acids were assayed by cation exchange chromatography Diabetes-associated changes in AA composition of type I collagen mainly affect those amino acids which are known to be involved in helix formation and cross-linking of the molecules. Diabetes was found to significantly reduce bone collagen contents of o-Pro, Gly, Ala, o-Lys and Pro, whereas Lys, His, Arg, Glu, Thr, Leu, Phe contents were elevated (P vitamin C and B3 contents were shown to be significantly lowered, whereas a-tocopherol was slightly increased compared with control (P vitamin C and B3 was observed. The data demonstrate the close relationship between the diabetes-associated decrease in type I collagen deposition, altered amino acids metabolism and impaired availability of vitamins, which are necessary for collagen synthesis. Thus, NAm might be a useful agent for treatment of bone failures related to diabetes.

  6. Uncovering nanoscale electromechanical heterogeneity in the subfibrillar structure of collagen fibrils responsible for the piezoelectricity of bone.

    Science.gov (United States)

    Minary-Jolandan, Majid; Yu, Min-Feng

    2009-07-28

    Understanding piezoelectricity, the linear electromechanical transduction, in bone and tendon and its potential role in mechanoelectric transduction leading to their growth and remodeling remains a challenging subject. With high-resolution piezoresponse force microscopy, we probed piezoelectric behavior in relevant biological samples at different scale levels: from the subfibrillar structures of single isolated collagen fibrils to bone. We revealed that, beyond the general understanding of collagen fibril being a piezoelectric material, there existed an intrinsic piezoelectric heterogeneity within a collagen fibril coinciding with the periodic variation of its gap and overlap regions. This piezoelectric heterogeneity persisted even for the collagen fibrils embedded in bone, bringing about new implications for its possible roles in structural formation and remodeling of bone.

  7. Chemical structure, biosynthesis and synthesis of free and glycosylated pyridinolines formed by cross-link of bone and synovium collagen.

    Science.gov (United States)

    Anastasia, Luigi; Rota, Paola; Anastasia, Mario; Allevi, Pietro

    2013-09-21

    This review focuses on the chemical structure, biosynthesis and synthesis of free and glycosylated pyridinolines (Pyds), fluorescent collagen cross-links, with a pyridinium salt structure. Pyds derive from the degradation of bone collagen and have attracted attention for their use as biochemical markers of bone resorption and to assess fracture risk prediction in persons suffering from osteoporosis, bone cancer and other bone or collagen diseases. We consider and critically discuss all reported syntheses of free and glycosylated Pyds evidencing an unrevised chemistry, original and of general utility, analysis of which allows us to also support a previously suggested non-enzymatic formation of Pyds in collagen better rationalizing and justifying the chemical events.

  8. Guided bone regeneration with asymmetric collagen-chitosan membranes containing aspirin-loaded chitosan nanoparticles.

    Science.gov (United States)

    Zhang, Jiayu; Ma, Shiqing; Liu, Zihao; Geng, Hongjuan; Lu, Xin; Zhang, Xi; Li, Hongjie; Gao, Chenyuan; Zhang, Xu; Gao, Ping

    2017-01-01

    Membranes allowing the sustained release of drugs that can achieve cell adhesion are very promising for guided bone regeneration. Previous studies have suggested that aspirin has the potential to promote bone regeneration. The purpose of this study was to prepare a local drug delivery system with aspirin-loaded chitosan nanoparticles (ACS) contained in an asymmetric collagen-chitosan membrane (CCM). In this study, the ACS were fabricated using different concentrations of aspirin (5 mg, 25 mg, 50 mg, and 75 mg). The drug release behavior of ACS was studied. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to examine the micromorphology of ACS and aspirin-loaded chitosan nanoparticles contained in chitosan-collagen membranes (ACS-CCM). In vitro bone mesenchymal stem cells (BMSCs) were cultured and critical-sized cranial defects on Sprague-Dawley rats were made to evaluate the effect of the ACS-CCM on bone regeneration. Drug release behavior results of ACS showed that the nanoparticles fabricated in this study could successfully sustain the release of the drug. TEM showed the morphology of the nanoparticles. SEM images indicated that the asymmetric membrane comprised a loose collagen layer and a dense chitosan layer. In vitro studies showed that ACS-CCM could promote the proliferation of BMSCs, and that the degree of differentiated BMSCs seeded on CCMs containing 50 mg of ACS was higher than that of other membranes. Micro-computed tomography showed that 50 mg of ACS-CCM resulted in enhanced bone regeneration compared with the control group. This study shows that the ACS-CCM would allow the sustained release of aspirin and have further osteogenic potential. This membrane is a promising therapeutic approach to guiding bone regeneration.

  9. Comparative Efficacies of Collagen-Based 3D Printed PCL/PLGA/β-TCP Composite Block Bone Grafts and Biphasic Calcium Phosphate Bone Substitute for Bone Regeneration.

    Science.gov (United States)

    Hwang, Kyoung-Sub; Choi, Jae-Won; Kim, Jae-Hun; Chung, Ho Yun; Jin, Songwan; Shim, Jin-Hyung; Yun, Won-Soo; Jeong, Chang-Mo; Huh, Jung-Bo

    2017-04-17

    The purpose of this study was to compare bone regeneration and space maintaining ability of three-dimensional (3D) printed bone grafts with conventional biphasic calcium phosphate (BCP). After mixing polycaprolactone (PCL), poly (lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) in a 4:4:2 ratio, PCL/PLGA/β-TCP particulate bone grafts were fabricated using 3D printing technology. Fabricated particulate bone grafts were mixed with atelocollagen to produce collagen-based PCL/PLGA/β-TCP composite block bone grafts. After formation of calvarial defects 8 mm in diameter, PCL/PLGA/β-TCP composite block bone grafts and BCP were implanted into bone defects of 32 rats. Although PCL/PLGA/β-TCP composite block bone grafts were not superior in bone regeneration ability compared to BCP, the results showed relatively similar performance. Furthermore, PCL/PLGA/β-TCP composite block bone grafts showed better ability to maintain bone defects and to support barrier membranes than BCP. Therefore, within the limitations of this study, PCL/PLGA/β-TCP composite block bone grafts could be considered as an alternative to synthetic bone grafts available for clinical use.

  10. Assessment of tricalcium phosphate/collagen (TCP/collagene)nanocomposite scaffold compared with hydroxyapatite (HA) on healing of segmental femur bone defect in rabbits.

    Science.gov (United States)

    Mohseni, Mahmoud; Jahandideh, Alireza; Abedi, Gholamreza; Akbarzadeh, Abolfazl; Hesaraki, Saeed

    2018-03-01

    Bone regeneration is an important objective in clinical practice and has been used for different applications. The aim of this study was to evaluate the effectiveness of nanocomposite tricalcium phosphate (TCP)/collagen scaffolds combined with hydroxyapatite scaffold for bone healing in surgery of femoral defects in rabbits. In this study, 45 mature male New Zealand white rabbits between 6 and 8 months old and weighting between 3 and 3.5 kg were examined. Rabbits were divided into three groups. Surgical procedures were performed after intramuscular injection of Ketamine 10% (ketamine hydrochloride, 50 mg/kg) and Rompun 5% (xylazine, 5 mg/kg). Then an approximately 6 mm diameter-5 mm cylinder bone defect was created in the femur of one of the hind limbs. After inducing the surgical wound, all rabbits were coloured and randomly divided into three experimental groups of 15 animals each. Group 1 received pure medical nanocomposite TCP/collagen granules, group 2 received hydroxyapatite, and third group was a control group which received no treatment. Histopathological evaluation was performed on days 15, 30, and 45 after surgery. On days 15, 30, and 45 after surgery, the quantity and the velocity of stages of bone formation at the healing site in nanocomposite TCP/collagen group were better than HA and control groups and the quantity of newly formed lamellar bone at the healing site in nanocomposite TCP/collagen group were better than onward compared with HA and control groups. In conclusion, it seems that TCP/collagen nanocomposite has a significant role in the reconstruction of bone defects and can be used as scaffold in bone fractures.

  11. Normal Collagen and Bone Production by Gene-targeted Human Osteogenesis Imperfecta iPSCs

    Science.gov (United States)

    Deyle, David R; Khan, Iram F; Ren, Gaoying; Wang, Pei-Rong; Kho, Jordan; Schwarze, Ulrike; Russell, David W

    2012-01-01

    Osteogenesis imperfecta (OI) is caused by dominant mutations in the type I collagen genes. In principle, the skeletal abnormalities of OI could be treated by transplantation of patient-specific, bone-forming cells that no longer express the mutant gene. Here, we develop this approach by isolating mesenchymal cells from OI patients, inactivating their mutant collagen genes by adeno-associated virus (AAV)-mediated gene targeting, and deriving induced pluripotent stem cells (iPSCs) that were expanded and differentiated into mesenchymal stem cells (iMSCs). Gene-targeted iMSCs produced normal collagen and formed bone in vivo, but were less senescent and proliferated more than bone-derived MSCs. To generate iPSCs that would be more appropriate for clinical use, the reprogramming and selectable marker transgenes were removed by Cre recombinase. These results demonstrate that the combination of gene targeting and iPSC derivation can be used to produce potentially therapeutic cells from patients with genetic disease. PMID:22031238

  12. Collagen/Beta-Tricalcium Phosphate Based Synthetic Bone Grafts via Dehydrothermal Processing

    Directory of Open Access Journals (Sweden)

    Burcu Sarikaya

    2015-01-01

    Full Text Available Millions of patients worldwide remain inadequately treated for bone defects related to factors such as disease or trauma. The drawbacks of metallic implant and autograft/allograft use have steered therapeutic approaches towards tissue engineering solutions involving tissue regeneration scaffolds. This study proposes a composite scaffold with properties tailored to address the macro- and microenvironmental conditions deemed necessary for successful regeneration of bone in defect areas. The biodegradable scaffold composed of porous beta-tricalcium phosphate particles and collagen type I fibers is prepared from a mixture of collagen type-I and β-tricalcium phosphate (β-TCP particles via lyophilization, followed by dehydrothermal (DHT processing. The effects of both sterilization via gamma radiation and the use of DHT processing to achieve cross-linking were investigated. The impact of the chosen fabrication methods on scaffold microstructure and β-TCP particle-collagen fiber combinations were analyzed using X-ray diffractometry (XRD, scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, differential scanning calorimetry (DSC, and microcomputerized tomography (µ-CT. Electron spinning resonance (ESR analysis was used to investigate free radicals formation following sterilization. Results revealed that the highly porous (65% porosity at an average of 100 µm pore size, mechanically adequate, and biocompatible scaffolds can be utilized for bone defect repairs.

  13. Collagen/Beta-Tricalcium Phosphate Based Synthetic Bone Grafts via Dehydrothermal Processing.

    Science.gov (United States)

    Sarikaya, Burcu; Aydin, Halil Murat

    2015-01-01

    Millions of patients worldwide remain inadequately treated for bone defects related to factors such as disease or trauma. The drawbacks of metallic implant and autograft/allograft use have steered therapeutic approaches towards tissue engineering solutions involving tissue regeneration scaffolds. This study proposes a composite scaffold with properties tailored to address the macro- and microenvironmental conditions deemed necessary for successful regeneration of bone in defect areas. The biodegradable scaffold composed of porous beta-tricalcium phosphate particles and collagen type I fibers is prepared from a mixture of collagen type-I and β-tricalcium phosphate (β-TCP) particles via lyophilization, followed by dehydrothermal (DHT) processing. The effects of both sterilization via gamma radiation and the use of DHT processing to achieve cross-linking were investigated. The impact of the chosen fabrication methods on scaffold microstructure and β-TCP particle-collagen fiber combinations were analyzed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and microcomputerized tomography (µ-CT). Electron spinning resonance (ESR) analysis was used to investigate free radicals formation following sterilization. Results revealed that the highly porous (65% porosity at an average of 100 µm pore size), mechanically adequate, and biocompatible scaffolds can be utilized for bone defect repairs.

  14. Preparation of flexible bone tissue scaffold utilizing sea urchin test and collagen.

    Science.gov (United States)

    Manchinasetty, Naga Vijaya Lakshmi; Oshima, Sho; Kikuchi, Masanori

    2017-10-13

    Gonads of sea urchin are consumed in Japan and some countries as food and most parts including its tests are discarded as marine wastes. Therefore, utilization of them as functional materials would reduce the waste as well as encourage Japanese fishery. In this study, magnesium containing calcite granules collected from sea urchin tests were hydrothermally phosphatized and the obtained granules were identified as approximately 82% in mass of magnesium containing β-tricalcium phosphate and 18% in mass of nonstoichiometric hydroxyapatite, i.e., a biphasic calcium phosphate, maintaining the original porous network. Shape-controlled scaffolds were fabricated with the obtained biphasic calcium phosphate granules and collagen. The scaffolds showed good open porosity (83.84%) and adequate mechanical properties for handling during cell culture and subsequent operations. The MG-63 cells showed higher proliferation and osteogenic differentiation in comparison to a control material, the collagen sponge with the same size. Furthermore, cell viability assay proved that the scaffolds were not cytotoxic. These results suggest that scaffold prepared using sea urchin test derived calcium phosphate and collagen could be a potential candidate of bone void fillers for non-load bearing defects in bone reconstruction as well as scaffolds for bone tissue engineering.

  15. Collagen type I from bovine bone. Effect of animal age, bone anatomy and drying methodology on extraction yield, self-assembly, thermal behaviour and electrokinetic potential

    OpenAIRE

    Ferraro, Vincenza; Gaillard-Martinie, Brigitte; Sayd, Thierry; Chambon, Christophe; Anton, Marc; Sante-Lhoutellier, Veronique

    2017-01-01

    Natural collagen is easily available from animal tissues such as bones. Main limitations reported in the use of natural collagen are heterogeneity and loss of integrity during recovery. However, its natural complexity, functionality and bioactivity still remain to be achieved through synthetic and recombinant ways. Variability of physicochemical prope...

  16. Alveolar ridge preservation with deproteinized bovine bone graft and collagen membrane and delayed implants.

    Science.gov (United States)

    Pang, Chaoyuan; Ding, Yuxiang; Zhou, Hongzhi; Qin, Ruifeng; Hou, Rui; Zhang, Guoliang; Hu, Kaijin

    2014-09-01

    To evaluate clinically and radiographically an alveolar ridge, preservation technique with deproteinized bovine bone graft and absorbable collagen membrane and then restoration with delayed implants were done. The study included 30 patients. The trial group's sockets were filled with deproteinized bovine bone graft (Bio-Oss) and covered with absorbable collagen membrane (Bio-Gide). The control group's sockets healed without any treatment. Panoramic radiograph and computed tomography were taken immediately after graft and 3 and 6 months later to evaluate the height, width, and volume change of the alveolar ridge bone. Dental implants were inserted in all sockets at 6 months, and osseointegration condition was evaluated in the following 12 months. All sockets healed uneventfully. In the trial group, the mean (SD) height reduction of the alveolar ridge bone was 1.05 (0.24) mm at 3 months and 1.54 (0.25) mm at 6 months. The width reduction was 1.11 (0.13) mm at 3 months and 1.84 (0.35) mm at 6 months. Bone volume reduction was 193.79 (21.47) mm at 3 months and 262.06 (33.08) mm at 6 months. At the same trend, in the control group, the bone height reduction was 2.12 (0.15) mm at 3 months and 3.26 (0.29) mm at 6 months. The width reduction was 2.72 (0.19) mm at 3 months and 3.56 (0.28) mm at 6 months. Bone volume reduction was 252.19 (37.21) mm at 3 months and 342.32 (36.41) mm at 6 months. There was a significant difference in alveolar ridge bone height, width, and volume reduction in the 2 groups. The osseointegration condition had no significant difference between the 2 groups. This study suggested that the deproteinized bovine bone graft and absorbable collagen membrane were beneficial to preserve the alveolar ridge bone and had no influence on the osseointegration of delayed implant.

  17. Effects of the bilayer nano-hydroxyapatite/mineralized collagen-guided bone regeneration membrane on site preservation in dogs.

    Science.gov (United States)

    Sun, Yi; Wang, Chengyue; Chen, Qixin; Liu, Hai; Deng, Chao; Ling, Peixue; Cui, Fu-Zhai

    2017-08-01

    This study was aimed at assessing the effects of the porous mineralized collagen plug with or without the bilayer mineralized collagen-guided bone regeneration membrane on alveolar ridge preservation in dogs. The third premolars in the bilateral maxilla of mongrel dogs ( N = 12) were extracted. Twenty-four alveolar sockets were thus randomly divided into three groups: membrane + collagen plug (MP, n = 8), nonmembrane + collagen plug (NP, n = 8) and blank group without any implantation (BG, n = 8). Radiographic assessment was carried out immediately and in the 2nd, 6th, and 12th week after surgery. The bone-repairing effects of the two grafts were respectively evaluated by clinical observation, X-ray micro-computed tomography examination, and histological analysis in the 8th and 12th week after surgery. Three groups presented excellent osseointegration without any inflammation or dehiscence. X-ray micro-computed tomography and histological assessment indicated that the ratios of new bone formation of MP group were significantly higher than those of NP group and BG group in the 8th and 12th week after surgery ( P guided bone regeneration membrane could reduce the absorption of alveolar ridge compared to BG group, and the combined use of porous mineralized collagen plug and bilayer mineralized collagen-guided bone regeneration could further improve the activity of bone regeneration.

  18. Rapid biomimetic mineralization of collagen fibrils and combining with human umbilical cord mesenchymal stem cells for bone defects healing

    International Nuclear Information System (INIS)

    Ye, Bihua; Luo, Xueshi; Li, Zhiwen; Zhuang, Caiping; Li, Lihua; Lu, Lu; Ding, Shan; Tian, Jinhuan; Zhou, Changren

    2016-01-01

    Collagen biomineralization is regulated by complicated interactions between the collagen matrix and non-collagenous extracellular proteins. Here, the use of sodium tripolyphosphate to simulate the templating functional motif of the C-terminal fragment of non-collagenous proteins is reported, and a low molecular weight polyacrylic acid served as a sequestration agent to stabilize amorphous calcium phosphate into nanoprecursors. Self-assembled collagen fibrils served as a fixed template for achieving rapid biomimetic mineralization in vitro. Results demonstrated that, during the mineralization process, intrafibrillar and extrafibrillar hydroxyapatite mineral with collagen fibrils formed and did so via bottom-up nanoparticle assembly based on the non-classical crystallization approach in the presence of these dual biomimetic functional analogues. In vitro human umbilical cord mesenchymal stem cell (hUCMSC) culture found that the mineralized scaffolds have a better cytocompatibility in terms of cell viability, adhesion, proliferation, and differentiation into osteoblasts. A rabbit femoral condyle defect model was established to confirm the ability of the n-HA/collagen scaffolds to facilitate bone regeneration and repair. The images of gross anatomy, MRI, CT and histomorphology taken 6 and 12 weeks after surgery showed that the biomimetic mineralized collagen scaffolds with hUCMSCs can promote the healing speed of bone defects in vivo, and both of the scaffolds groups performing better than the bone defect control group. As new bone tissue formed, the scaffolds degraded and were gradually absorbed. All these results demonstrated that both of the scaffolds and cells have better histocompatibility. - Highlights: • A rapid and facile biomimetic mineralization approach is proposed. • Intrafibrillar and extrafibrillar mineralization of collagen fibrils was achieved. • HA/COL scaffolds promote hUCMSCs adhesion, proliferation, and differentiation. • Feasibility of h

  19. In Vitro Mineralization of an Osteoid-Like Dense Collagen Construct for Bone Tissue Engineering

    Science.gov (United States)

    Marelli, Benedetto

    The aim of this doctoral research was to design and evaluate strategies to rapidly achieve an acellular mineralization of an osteoid-like dense collagen gel for potential applications in bone regeneration. It was hypothesized that the collagen fibrillar density (CFD) affects the microenvironment and the physical properties of the framework of collagen gels. To test this hypothesis, and as a first objective, the mineralization of collagen gel sheets, rolls and strips with increasing CFDs was investigated in vitro in simulated body fluid (SBF). Collagen gels with physiologically relevant CFDs (14.1 wt%) led to greater extent of mineralization (12 dry wt% at day 14 in SBF), when compared to highly hydrated gels. Chemical characterization confirmed this mineral phase to be CHA, which significantly increased the gel apparent modulus and ultimate tensile strength (UTS). Surprisingly, CFD also affected the electrostatic properties of collagen gel, as investigated by quantifying the extent of anionic and cationic dyes bound to collagen gels with different CFDs. It was therefore proposed that the increase in gel CFD led to a more physiological microenvironment, resulting in a higher number of fibril-to-fibril contact points and an increase in charge concentration, which facilitated the mineral formation and validated the proposed osteoid model. As a second objective, the mineralization of dense collagen (DC) gels with physiologically relevant CFD (14.1 wt%) was enhanced and accelerated by mimicking the role of anionic non collagenous proteins (NCPs) in the native osteoid, which act as CHA nucleators. Two strategies were implemented: first, the influence of collagen fibrillization pH on the extent of DC gel mineralization was investigated. Since the collagen molecule is slightly positively charged at physiological pH (isoelectric point at pH 7.8), it was hypothesized that it would be more negatively charged if formed in an alkaline environment, i.e., above its isoelectric

  20. One-stage horizontal guided bone regeneration with autologous bone, anorganic bovine bone and collagen membranes: Follow-up of a prospective study 30 months after loading.

    Science.gov (United States)

    Meloni, Silvio Mario; Jovanovic, Sascha Alexander; Pisano, Milena; De Riu, Giacomo; Baldoni, Edoardo; Tallarico, Marco

    2018-01-01

    To present the medium-term results of one-stage guided bone regeneration (GBR) using autologous bone and anorganic bovine bone, placed in layers, in association with resorbable collagen membranes, for the reconstruction of horizontal bony defects. This study was designed as an uncontrolled prospective study. Partially edentulous patients, having less than 6.0 mm and more than 4.0 mm of residual horizontal bone width were selected and consecutively treated with simultaneously implant installation and bone regeneration by using 2.0 mm of autologous bone and 2.0 mm of anorganic bovine bone that was placed in layers and then covered with a resorbable collagen membrane. Outcome measures were: implant and prosthesis failures, any complications, peri-implant marginal bone level changes, probing pocket depth (PPD) and bleeding on probing (BOP). In total, 45 consecutive patients (20 male, 25 female) with a mean age of 52.1 years each received at least one GBR procedure, with contemporary placement of 63 implants. At the 3-year follow-up examination, no patient had dropped out and no deviation from the original protocol had occurred. No implant or prosthesis failed. In six patients (13.3%) the collagen membrane was slightly exposed 1 to 2 weeks after bone reconstruction. Four of these patients were moderate smokers. Post-hoc analysis using Fisher's exact test found significant association (P = 0.0139) between a smoking habit and early membrane exposure. Mean marginal bone loss experienced between initial loading and 30 months afterwards was 0.60 ± 0.20 mm (95% CI 0.54 - 0.66). The mean BOP values measured at the definitive restoration delivery were 1.23 ± 0.93, while 2 years later they were 1.17 ± 0.78. The difference was not statistically significant (-0.06 ± 0.76; P = 0.569). The mean PPD values measured at the definitive restoration delivery were 2.62 ± 0.59 mm, while 2 years later they were 2.60 ± 0.54 mm. The difference was not statistically significant (-0.03

  1. Astronaut Bones: Stable Calcium Isotopes in Urine as a Biomarker of Bone Mineral Balance

    Science.gov (United States)

    Skulan, J.; Gordon, G. W.; Romaniello, S. J.; Anbar, A. D.; Smith, S. M.; Zwart, S.

    2016-12-01

    Bone loss is a common health concern, in conditions ranging from osteoporosis to cancer. Bone loss due to unloading is also an important health issue for astronauts. We demonstrate stable calcium isotopes, a tool developed in geochemistry, are capable of detecting real-time quantitative changes in net bone mineral balance (BMB) using serum and urine [1]. We validated this technique by comparing with DEXA and biomarker data in subjects during bed rest, a ground-based analog of space flight effects [2-4]. We now apply this tool to assess changes in astronauts' BMB before, during and after 4-6 month space missions. There is stable isotope fractionation asymmetry between bone formation and resorption. During bone formation there is a mass-dependent preference for "lighter" calcium isotopes to be removed from serum and incorporated into bone mineral. During bone resorption, there is no measurable isotopic discrimination between serum and bone. Hence, when bone formation rates exceed that of resorption, serum and urine become isotopically "heavy" due to the sequestration of "light" calcium in bone. Conversely, when bone resorption exceeds bone formation, serum and urine become isotopically "light" due to the release of the sequestered light calcium from bone. We measured Ca isotopes in urine of thirty International Space Station astronauts. Average Ca isotope values in astronauts' urine shift isotopically lighter during microgravity, consistent with negative net BMB. Within a month of return to Earth, astronauts returned to within error of their δ44Ca value prior to departure. Urine samples from astronauts testing bone loss countermeasures showed bisphosphonates provide a viable pharmacological countermeasure. Some, but not all, individuals appear able to resist bone loss through diet and intensive resistive exercise alone. This is a promising new technique for monitoring BMB in astronauts, and hopefully someday on the way to/from Mars, this also has important clinical

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-01

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

  3. Greener synthesis of electrospun collagen/hydroxyapatite composite fibers with an excellent microstructure for bone tissue engineering

    Science.gov (United States)

    Zhou, Yuanyuan; Yao, Hongchang; Wang, Jianshe; Wang, Dalu; Liu, Qian; Li, Zhongjun

    2015-01-01

    In bone tissue engineering, collagen/hydroxyapatite (HAP) fibrous composite obtained via electrospinning method has been demonstrated to support the cells’ adhesion and bone regeneration. However, electrospinning of natural collagen often requires the use of cytotoxic organic solvents, and the HAP crystals were usually aggregated and randomly distributed within a fibrous matrix of collagen, limiting their clinical potential. Here, an effective and greener method for the preparation of collagen/HAP composite fibers was developed for the first time, and this green product not only had 40 times higher mechanical properties than that previously reported, but also had an excellent microstructure similar to that of natural bone. By dissolving type I collagen in environmentally friendly phosphate buffered saline/ethanol solution instead of the frequently-used cytotoxic organic solvents, followed with the key step of desalination, co-electrospinning the collagen solution with the HAP sol, generates a collagen/HAP composite with a uniform and continuous fibrous morphology. Interestingly, the nano-HAP needles were found to preferentially orient along the longitudinal direction of the collagen fibers, which mimicked the nanostructure of natural bones. Based on the characterization of the related products, the formation mechanism for this novel phenomenon was proposed. After cross-linking with 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride/N-hydroxysuccinimide, the obtained composite exhibited a significant enhancement in mechanical properties. In addition, the biocompatibility of the obtained composite fibers was evaluated by in vitro culture of the human myeloma cells (U2-OS). Taken together, the process outlined herein provides an effective, non-toxic approach for the fabrication of collagen/HAP composite nanofibers that could be good candidates for bone tissue engineering. PMID:25995630

  4. Greener synthesis of electrospun collagen/hydroxyapatite composite fibers with an excellent microstructure for bone tissue engineering.

    Science.gov (United States)

    Zhou, Yuanyuan; Yao, Hongchang; Wang, Jianshe; Wang, Dalu; Liu, Qian; Li, Zhongjun

    2015-01-01

    In bone tissue engineering, collagen/hydroxyapatite (HAP) fibrous composite obtained via electrospinning method has been demonstrated to support the cells' adhesion and bone regeneration. However, electrospinning of natural collagen often requires the use of cytotoxic organic solvents, and the HAP crystals were usually aggregated and randomly distributed within a fibrous matrix of collagen, limiting their clinical potential. Here, an effective and greener method for the preparation of collagen/HAP composite fibers was developed for the first time, and this green product not only had 40 times higher mechanical properties than that previously reported, but also had an excellent microstructure similar to that of natural bone. By dissolving type I collagen in environmentally friendly phosphate buffered saline/ethanol solution instead of the frequently-used cytotoxic organic solvents, followed with the key step of desalination, co-electrospinning the collagen solution with the HAP sol, generates a collagen/HAP composite with a uniform and continuous fibrous morphology. Interestingly, the nano-HAP needles were found to preferentially orient along the longitudinal direction of the collagen fibers, which mimicked the nanostructure of natural bones. Based on the characterization of the related products, the formation mechanism for this novel phenomenon was proposed. After cross-linking with 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride/N-hydroxysuccinimide, the obtained composite exhibited a significant enhancement in mechanical properties. In addition, the biocompatibility of the obtained composite fibers was evaluated by in vitro culture of the human myeloma cells (U2-OS). Taken together, the process outlined herein provides an effective, non-toxic approach for the fabrication of collagen/HAP composite nanofibers that could be good candidates for bone tissue engineering.

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

    Directory of Open Access Journals (Sweden)

    Wilairat Leeanansaksiri

    2013-01-01

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

  6. Osteogenesis imperfecta due to mutations in non-collagenous genes: lessons in the biology of bone formation.

    Science.gov (United States)

    Marini, Joan C; Reich, Adi; Smith, Simone M

    2014-08-01

    Osteogenesis imperfecta or 'brittle bone disease' has mainly been considered a bone disorder caused by collagen mutations. Within the last decade, however, a surge of genetic discoveries has created a new paradigm for osteogenesis imperfecta as a collagen-related disorder, where most cases are due to autosomal dominant type I collagen defects, while rare, mostly recessive, forms are due to defects in genes whose protein products interact with collagen protein. This review is both timely and relevant in outlining the genesis, development, and future of this paradigm shift in the understanding of osteogenesis imperfecta. Bone-restricted interferon-induced transmembrane (IFITM)-like protein (BRIL) and pigment epithelium-derived factor (PEDF) defects cause types V and VI osteogenesis imperfecta via defective bone mineralization, while defects in cartilage-associated protein (CRTAP), prolyl 3-hydroxylase 1 (P3H1), and cyclophilin B (CYPB) cause types VII-IX osteogenesis imperfecta via defective collagen post-translational modification. Heat shock protein 47 (HSP47) and FK506-binding protein-65 (FKBP65) defects cause types X and XI osteogenesis imperfecta via aberrant collagen crosslinking, folding, and chaperoning, while defects in SP7 transcription factor, wingless-type MMTV integration site family member 1 (WNT1), trimeric intracellular cation channel type b (TRIC-B), and old astrocyte specifically induced substance (OASIS) disrupt osteoblast development. Finally, absence of the type I collagen C-propeptidase bone morphogenetic protein 1 (BMP1) causes type XII osteogenesis imperfecta due to altered collagen maturation/processing. Identification of these multiple causative defects has provided crucial information for accurate genetic counseling, inspired a recently proposed functional grouping of osteogenesis imperfecta types by shared mechanism to simplify current nosology, and has prodded investigations into common pathways in osteogenesis imperfecta. Such

  7. Adipose-Derived Mesenchymal Stem Cells Prevent Systemic Bone Loss in Collagen-Induced Arthritis.

    Science.gov (United States)

    Garimella, Manasa G; Kour, Supinder; Piprode, Vikrant; Mittal, Monika; Kumar, Anil; Rani, Lekha; Pote, Satish T; Mishra, Gyan C; Chattopadhyay, Naibedya; Wani, Mohan R

    2015-12-01

    Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammatory synovitis leading to joint destruction and systemic bone loss. The inflammation-induced bone loss is mediated by increased osteoclast formation and function. Current antirheumatic therapies primarily target suppression of inflammatory cascade with limited or no success in controlling progression of bone destruction. Mesenchymal stem cells (MSCs) by virtue of their tissue repair and immunomodulatory properties have shown promising results in various autoimmune and degenerative diseases. However, the role of MSCs in prevention of bone destruction in RA is not yet understood. In this study, we investigated the effect of adipose-derived MSCs (ASCs) on in vitro formation of bone-resorbing osteoclasts and pathological bone loss in the mouse collagen-induced arthritis (CIA) model of RA. We observed that ASCs significantly inhibited receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis in both a contact-dependent and -independent manner. Additionally, ASCs inhibited RANKL-induced osteoclastogenesis in the presence of proinflammatory cytokines such as TNF-α, IL-17, and IL-1β. Furthermore, treatment with ASCs at the onset of CIA significantly reduced clinical symptoms and joint pathology. Interestingly, ASCs protected periarticular and systemic bone loss in CIA mice by maintaining trabecular bone structure. We further observed that treatment with ASCs reduced osteoclast precursors in bone marrow, resulting in decreased osteoclastogenesis. Moreover, ASCs suppressed autoimmune T cell responses and increased the percentages of peripheral regulatory T and B cells. Thus, we provide strong evidence that ASCs ameliorate inflammation-induced systemic bone loss in CIA mice by reducing osteoclast precursors and promoting immune tolerance. Copyright © 2015 by The American Association of Immunologists, Inc.

  8. Onlay bone augmentation on mouse calvarial bone using a hydroxyapatite/collagen composite material with total blood or platelet-rich plasma.

    Science.gov (United States)

    Ohba, Seigo; Sumita, Yoshinori; Umebayashi, Mayumi; Yoshimura, Hitoshi; Yoshida, Hisato; Matsuda, Shinpei; Kimura, Hideki; Asahina, Izumi; Sano, Kazuo

    2016-01-01

    The aim of this study was to assess newly formed onlay bone on mouse calvarial bone using a new artificial bone material, a hydroxyapatite/collagen composite, with total blood or platelet-rich plasma. The hydroxyapatite/collagen composite material with normal saline, total blood or platelet-rich plasma was transplanted on mouse calvarial bone. The mice were sacrificed and the specimens were harvested four weeks after surgery. The newly formed bone area was measured on hematoxylin and eosin stained specimens using Image J software. The hydroxyapatite/collagen composite materials with total blood or platelet-rich plasma induced a significantly greater amount of newly formed bone than that with normal saline. Moreover, bone marrow was observed four weeks after surgery in the transplanted materials with total blood or platelet-rich plasma but not with normal saline. However, there were no significant differences in the amount of newly formed bone between materials used with total blood versus platelet-rich plasma. The hydroxyapatite/collagen composite material was valid for onlay bone augmentation and this material should be soaked in total blood or platelet-rich plasma prior to transplantation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Effect of Simvastatin collagen graft on wound healing of defective bone

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jun Ho; Kim, Gyu Tae [Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of); Choi, Yong Suk; Lee, Hyeon Woo; Hwang, Eui Hwan [Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    2008-09-15

    To observe and evaluate the effects of Simvastatin-induced osteogenesis on the wound healing of defective bone. 64 defective bones were created in the parietal bone of 32 New Zealand White rabbits. The defects were grafted with collagen matrix carriers mixed with Simvastatin solution in the experimental group of 16 rabbits and with collagen matrix carriers mixed with water in the controlled group. The rabbits were terminated at an interval of 3, 5, 7, and 9 days, 2, 4, 6, and 8 weeks after the formation of defective bone. The wound healing was evaluated by soft X-ray radiography. The tissues within defective bones were evaluated through the analysis of flow cytometry for the manifestation of Runx2 and Osteocalcin, and observed histopathologically by using H-E stain and Masson's trichrome stain. Results : 1. In the experimental group, flow cytometry revealed more manifestation of Runx2 at 5, 7, and 9 days and Osteocalcin at 2 weeks than in the controlled groups, but there was few difference in comparison with the controlled group. 2. In the experimental group, flow cytometry revealed considerably more cells and erythrocytes at 5, 7, and 9 days in comparison with the controlled group. 3. In the experimental group, soft x-ray radiography revealed the extended formation of trabeculation at 2, 4, 6, and 8 weeks. 4. Histopathological features of the experimental group showed more fibroblasts and newly formed vessels at 5 and 7 days, and the formation of osteoid tissues at 9 days, and the newly formed trabeculations at 4 and 6 weeks. As the induced osteogenesis by Simvastatin, there was few contrast of the manifestation between Runx2 and Osteocalcin based on the differentiation of osteoblasts. But it was considered that the more formation of cells and erythrocytes depending on newly formed vessels in the experimental group obviously had an effect on the bone regeneration.

  10. Collagen osteoid-like model allows kinetic gene expression studies of non-collagenous proteins in relation with mineral development to understand bone biomineralization.

    Directory of Open Access Journals (Sweden)

    Jérémie Silvent

    Full Text Available Among persisting questions on bone calcification, a major one is the link between protein expression and mineral deposition. A cell culture system is here proposed opening new integrative studies on biomineralization, improving our knowledge on the role played by non-collagenous proteins in bone. This experimental in vitro model consisted in human primary osteoblasts cultured for 60 days at the surface of a 3D collagen scaffold mimicking an osteoid matrix. Various techniques were used to analyze the results at the cellular and molecular level (adhesion and viability tests, histology and electron microscopy, RT- and qPCR and to characterize the mineral phase (histological staining, EDX, ATG, SAED and RMN. On long term cultures human bone cells seeded on the osteoid-like matrix displayed a clear osteoblast phenotype as revealed by the osteoblast-like morphology, expression of specific protein such as alkaline phosphatase and expression of eight genes classically considered as osteoblast markers, including BGLAP, COL1A1, and BMP2. Von Kossa and alizarine red allowed us to identify divalent calcium ions at the surface of the matrix, EDX revealed the correct Ca/P ratio, and SAED showed the apatite crystal diffraction pattern. In addition RMN led to the conclusion that contaminant phases were absent and that the hydration state of the mineral was similar to fresh bone. A temporal correlation was established between quantified gene expression of DMP1 and IBSP, and the presence of hydroxyapatite, confirming the contribution of these proteins to the mineralization process. In parallel a difference was observed in the expression pattern of SPP1 and BGLAP, which questioned their attributed role in the literature. The present model opens new experimental possibilities to study spatio-temporal relations between bone cells, dense collagen scaffolds, NCPs and hydroxyapatite mineral deposition. It also emphasizes the importance of high collagen density

  11. Aragonite crystals grown on bones by reaction of CO2 with nanostructured Ca(OH)2 in the presence of collagen. Implications in archaeology and paleontology.

    Science.gov (United States)

    Natali, Irene; Tempesti, Paolo; Carretti, Emiliano; Potenza, Mariangela; Sansoni, Stefania; Baglioni, Piero; Dei, Luigi

    2014-01-21

    The loss of mechanical properties affecting archeological or paleontological bones is often caused by demineralization processes that are similar to those driving the mechanisms leading to osteoporosis. One simple way to harden and to strengthen demineralized bone remains could be the in situ growth of CaCO3 crystals in the aragonite polymorph - metastable at atmospheric pressure -which is known to have very strong mechanical strength in comparison with the stable calcite. In the present study the controlled growth of aragonite crystals was achieved by reaction between atmospheric CO2 and calcium hydroxide nanoparticles in the presence of collagen within the deteriorated bones. In a few days the carbonation of Ca(OH)2 particles led to a mixture of calcite and aragonite, increasing the strength of the mineral network of the bone. Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier transform infrared (FT-IR) spectrometry showed that aragonite crystallization was achieved. The effect of the aragonite crystal formation on the mechanical properties of the deteriorated bones was investigated by means of X-rays microtomography, helium porosimetry, atomic force microscopy (AFM), and Vickers microhardness techniques. All these data enabled to conclude that the strength of the bones increased of a factor of 50-70% with respect to the untreated bone. These results could have immediate impact for preserving archeological and paleontological bone remains.

  12. 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

    DEFF Research Database (Denmark)

    Jensen, Jonas; Foldager, Casper Bindzus; Jakobsen, Thomas Vestergaard

    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...

  13. Effect of local hemostatics on bone induction in rats: a comparative study of bone wax, fibrin-collagen paste, and bioerodible polyorthoester with and without gentamicin

    DEFF Research Database (Denmark)

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

    1992-01-01

    evaluated by light microscopy and 85Sr uptake analyses. Non-absorbable bone wax of 88% beeswax and absorbable bovine fibrin-collagen paste both significantly inhibited osteoinduction, whereas a bioerodible polyorthoester drug delivery system with or without 4% gentamicin did not. Bone wax was not absorbed...

  14. Defective collagen crosslinking in bone, but not in ligament or cartilage, in bruck syndrome: Indications for a bone-specific telopeptide lysyl hydroxylase on chromosome 17

    NARCIS (Netherlands)

    Bank, R.A.; Robins, S.P.; Wijmenga, C.; Breslau-Siderius, L.J.; Bardoel, A.F.J.; Sluijs, H.A. van der; Pruijs, H.E.H.; Tekoppele, J.M.

    1999-01-01

    Bruck syndrome is characterized by the presence of osteoporosis, joint contractures, fragile bones, and short stature. We report that lysine residues within the telopeptides of collagen type I in bone are underhydroxylated, leading to aberrant crosslinking, but that the lysine residues in the triple

  15. Vertical Bone Augmentation Using Deproteinized Bovine Bone Mineral, Absorbable Collagen Sponge, and Recombinant Human Bone Morphogenetic Protein-2: An In Vivo Study in Rabbits.

    Science.gov (United States)

    Kim, Yeon Jung; de Molon, Rafael Rafael; Horiguti, Fausto Rioiti; Contador, Guilherme Piragine; Coelho, Marco Antonio; Mascarenhas, Vinicius Ibiapina; de Souza Faloni, Ana Paula; Cirelli, Joni Augusto; Sendyk, Wilson Roberto

    2018-03-15

    The objective of this investigation was to assess vertical bone augmentation using deproteinized bovine bone mineral (DBBM) infused or not with recombinant human bone morphogenetic protein (rhBMP-2) in rabbit tibiae. A total of 18 female rabbits (New Zealand) received two blocks of DBBM in each tibia. The DBBM blocks were randomly assigned into four experimental groups: DBBM (only the bone graft); DBBM associated with absorbable collagen sponge (ACS); DBBM plus rhBMP-2 (1.5 mg/mL); and DBBM infused with rhBMP-2 (1.5 mg/mL) in an ACS carrier. Animals were sacrificed after 12 weeks, and the tibiae containing the DBBM blocks were dissected and analyzed radiographically (microcomputed tomography [micro-CT]), histologically, and immunohistochemically. Micro-CT analysis showed a considerable increase in bone volume (BV) and BV/tissue volume in the rhBMP-2/ACS group compared with all the others. Trabeculae thickness also increased in the rhBMP-2/ACS group compared with the DBBM/ACS group. Trabecular number, separation, and bone mineral density were not different among groups. Histomorphometric evaluation showed increased newly formed bone in the rhBMP-2/ACS group compared with the DBBM and DBBM/ACS groups. The amount of residual bone graft was statistically higher in the rhBMP-2 groups compared with the DBBM/ACS group. Immunohistochemical analysis showed that the vascular endothelial growth factor (VEGF) expression was more intense in the rhBMP-2/ACS group compared with the DBBM/ACS group. The immunopositivity for type 1 collagen tended to be higher in the two groups with rhBMP-2. Collectively, the results of this study suggest that the addition of rhBMP-2 in an ACS carrier placed on top of the DBBM graft enhanced bone formation in this animal model.

  16. The effects of bone marrow aspirate, bone graft, and collagen composites on fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Sandri, Monica

    2012-01-01

    Replacement of extensive local bone loss especially in revision joint arthroplasty and spine fusion is a significant clinical challenge. Allograft and autograft have been considered as gold standards for bone replacement. However, there are several disadvantages such as donor site pain, bacterial...... on the early fixation of bone implants in this sheep model. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012....

  17. Collagen type I from bovine bone. Effect of animal age, bone anatomy and drying methodology on extraction yield, self-assembly, thermal behaviour and electrokinetic potential.

    Science.gov (United States)

    Ferraro, Vincenza; Gaillard-Martinie, Brigitte; Sayd, Thierry; Chambon, Christophe; Anton, Marc; Santé-Lhoutellier, Véronique

    2017-04-01

    Natural collagen is easily available from animal tissues such as bones. Main limitations reported in the use of natural collagen are heterogeneity and loss of integrity during recovery. However, its natural complexity, functionality and bioactivity still remain to be achieved through synthetic and recombinant ways. Variability of physicochemical properties of collagen extracted from bovine bone by acetic acid was then investigated taking into account endogenous and exogenous factors. Endogenous: bovine's bones age (4 and 7 years) and anatomy (femur and tibia); exogenous: thermal treatments (spray-drying and lyophilisation). Scanning electron microscopy, spectroscopy (EDS, FTIR, UV/Vis and CD), differential scanning calorimetry (DSC), centesimal composition, mass spectrometry, amino acids and zeta-potential analysis were used for the purpose. Age correlated negatively with yield of recovery and positively with minerals and proteoglycans content. Comparing the anatomy, higher yields were found for tibias, and higher stability of tibias collagen in solution was noticed. Whatever the age and the anatomy, collagens were able to renature and to self-assemble into tri-dimensional structures. Nonetheless thermal stability and kinetics of renaturation were different. Variability of natural collagen with bone age and anatomy, and drying methodology, may be a crucial advantage to conceive tailor-made applications in either the biological or technical sector. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Cleft palate reconstruction using collagen and nanofiber scaffold incorporating bone morphogenetic protein in rats.

    Science.gov (United States)

    Mostafa, Nesrine Z; Talwar, Reena; Shahin, Mostafa; Unsworth, Larry D; Major, Paul W; Doschak, Michael R

    2015-01-01

    Absorbable collagen sponge (ACS) loaded with bone morphogenetic protein-2 (BMP-2) is approved for selected clinical applications; however, burst release limits its widespread use. Therefore, nanofiber (NF)-based scaffold with ACS backbone was developed to sustain release of loaded BMP-2 to improve the outcomes of bone grafting in a rodent model of cleft palate. BMP-2 was loaded on ACS scaffold and then NF hydrogel with different densities (1-2%) was added to sustain the BMP-2 release. The release profiles of BMP-2 from constructs with different NF densities were evaluated in vitro to explore the optimum NF density that could recapitulate physiological bone healing process. Subsequently, scaffold with the appropriate NF density was implanted into a rodent model of cleft palate. Wistar rats, with surgically induced maxillary cleft defects, were then assigned to one of the following groups (n=6/group): no scaffold (control), ACS, ACS+BMP-2, NF+ACS, and NF+ACS+BMP-2. Micro-computed tomography (μCT) was utilized to evaluate percent bone filling (%BF) at defect site as well as changes in anteroposterior and transverse dimensions of the maxilla at weeks 0, 4, and 8. Histological assessment of bone healing was performed at week 8. In vitro release experiments showed that scaffolds containing 2% NF exhibited a release profile conducive to the natural stages of bone healing and, hence, it was utilized for subsequent in vivo studies. Bone healing occurred at the defect margins leaving a central bone void in the control, ACS, and NF+ACS groups over the 8-week study period. BMP-2-treated groups demonstrated higher %BF as compared with other groups at week 8 (pscaffold when compared with the ACS+BMP-2 group. NF+ACS+BMP-2 constructs exhibited osteoinductive properties together with preparation simplicity, which makes it a novel approach for BMP-2 delivery for cleft palate reconstruction.

  19. Preparation of dexamethasone-loaded biphasic calcium phosphate nanoparticles/collagen porous composite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Chen, Ying; Kawazoe, Naoki; Chen, Guoping

    2018-02-01

    Although bone is regenerative, its regeneration capacity is limited. For bone defects beyond a critical size, further intervention is required. As an attractive strategy, bone tissue engineering (bone TE) has been widely investigated to repair bone defects. However, the rapid and effective bone regeneration of large non-healing defects is still a great challenge. Multifunctional scaffolds having osteoinductivity and osteoconductivity are desirable to fasten functional bone tissue regeneration. In the present study, biomimetic composite scaffolds of collagen and biphasic calcium phosphate nanoparticles (BCP NPs) with a controlled release of dexamethasone (DEX) and the controlled pore structures were prepared for bone TE. DEX was introduced in the BCP NPs during preparation of the BCP NPs and hybridized with collagen scaffolds, which pore structures were controlled by using pre-prepared ice particulates as a porogen material. The composite scaffolds had well controlled and interconnected pore structures, high mechanical strength and a sustained release of DEX. The composite scaffolds showed good biocompatibility and promoted osteogenic differentiation of hMSCs when used for three-dimensional culture of human bone marrow-derived mesenchymal stem cells. Subcutaneous implantation of the composite scaffolds at the dorsa of athymic nude mice demonstrated that they facilitated the ectopic bone tissue regeneration. The results indicated the DEX-loaded BCP NPs/collagen composite scaffolds had high potential for bone TE. Scaffolds play a crucial role for regeneration of large bone defects. Biomimetic scaffolds having the same composition of natural bone and a controlled release of osteoinductive factors are desirable for promotion of bone regeneration. In this study, composite scaffolds of collagen and biphasic CaP nanoparticles (BCP NPs) with a controlled release nature of dexamethasone (DEX) were prepared and their porous structures were controlled by using ice particulates

  20. Guided Bone Regeneration in Long-Bone Defects with a Structural Hydroxyapatite Graft and Collagen Membrane

    Science.gov (United States)

    2013-01-01

    collagen type I. The fibrous tissue area infiltration to total area was measured based on color mapping in BioquantOsteo to select the area of...to the differences in distribution of pulverized autograft across the defect space between different animals in the group. The wrap group showed...1885 suitable mechanical environment.23 In this study, we evalu- ate a strategy to improve the regenerative capacity of struc- tural osteoconductive

  1. Enhanced bone regeneration using an insulin-loaded nano-hydroxyapatite/collagen/PLGA composite scaffold.

    Science.gov (United States)

    Wang, Xing; Zhang, Guilan; Qi, Feng; Cheng, Yongfeng; Lu, Xuguang; Wang, Lu; Zhao, Jing; Zhao, Bin

    2018-01-01

    Insulin is widely considered as a classical hormone and drug in maintaining energy and glucose homeostasis. Recently, insulin has been increasingly recognized as an indispensable factor for osteogenesis and bone turnover, but its applications in bone regeneration have been restricted because of the short periods of activity and uncontrolled release. In this study, we incorporated insulin-loaded poly lactic-co-glycolic-acid (PLGA) nanospheres into nano-hydroxyapatite/collagen (nHAC) scaffolds and investigated the bioactivity of the composite scaffolds in vitro and in vivo. Bioactive insulin was successfully released from the nanospheres within the scaffold, and the release kinetics of insulin could be efficiently controlled by uniform-sized nanospheres. The physical characterizations of the composite scaffolds demonstrated that incorporation of nanospheres in nHAC scaffolds using this method did not significantly change the porosity, pore diameters, and compressive strengths of nHAC. In vitro, the insulin-loaded nHAC/PLGA composite scaffolds possessed favorable biological function for bone marrow mesenchymal stem cells adhesion and proliferation, as well as the differentiation into osteoblasts. In vivo, the optimized bone regenerative capability of this composite scaffold was confirmed in rabbit mandible critical size defects. These results demonstrated successful development of a functional insulin-PLGA-nHAC composite scaffold that enhances the bone regeneration capability of nHAC.

  2. Osteogenesis Imperfecta due to Mutations in Non-Collagenous Genes-Lessons in the Biology of Bone Formation

    Science.gov (United States)

    Marini, Joan C.; Reich, Adi; Smith, Simone M.

    2014-01-01

    Purpose of Review Osteogenesis imperfecta (OI), or “brittle bone disease”, has mainly been considered a bone disorder caused by collagen mutations. Within the last decade, however, a surge of genetic discoveries has created a new paradigm for OI as a collagen-related disorder, where autosomal dominant type I collagen defects cause most cases, while rare, mostly recessive forms are due to defects in genes whose protein products interact with collagen protein. This review is both timely and relevant in outlining the genesis, development and future of this paradigm shift in the understanding of OI. Recent Findings BRIL and PEDF defects cause types V and VI OI via defective bone mineralization, while defects in CRTAP, P3H1 and CyPB cause types VII-IX via defective collagen post-translational modification. Hsp47 and FKBP65 defects cause types X and XI OI via aberrant collagen crosslinking, folding and chaperoning, while defects in SP7, WNT1, TRIC-B and OASIS disrupt osteoblast development. Finally, absence of the type I collagen C-propeptidase BMP1 causes type XII OI due to altered collagen maturation/processing. Summary Identification of these multiple causative defects has provided crucial information for accurate genetic counseling, inspired a recently proposed functional grouping of OI types by shared mechanism to simplify current nosology, and should prod investigations into common pathways in OI. Such investigations could yield critical information on cellular and bone tissue mechanisms and translate to new mechanistic insight into clinical therapies for patients. PMID:25007323

  3. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl Christian; Overgaard, Søren

    2012-01-01

    of 3 months without treatment. Group 3 was left untreated and served as controls. All sheep received a restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of each sheep were harvested, micro-CT scanned and subjected to three-point bending....... Collagen content was significantly increased in the glucocorticoid-2 compared with the glucocorticoid-1 and control groups. Bone mineral content did not differ between the groups. Neither the three-point bending mechanical properties nor the tensile mechanical properties differed significantly between...... the groups, while there was a trend towards decreasing bending mechanical properties in the glucocorticoid-2 group. In conclusion, 7 months of glucocorticoid treatment with malnutrition had a significant impact on the cortical microarchitecture of the sheep femur midshaft. These observed changes occurred 3...

  4. Puerarin decreases bone loss and collagen destruction in rats with ligature-induced periodontitis.

    Science.gov (United States)

    Yang, X; Zhang, H; Wang, J; Zhang, Z; Li, C

    2015-12-01

    Puerarin, the most abundant isoflavonoid in kudzu root, shows various bioactivities, including bone-sparing, anti-inflammatory and antiproteinase properties. This study aimed to evaluate the effects of puerarin in a rat model of ligature-induced periodontitis. Rat models of periodontitis were developed by bilaterally placing ligatures around the first mandibular molars. Puerarin was administrated daily by gavage at doses of 100, 200 and 400 mg/kg, starting a day before the placement of ligatures. Rats were humanely killed 7 d after the induction of periodontitis. Micro-computed tomography and sirius red staining were used to evaluate alveolar bone loss and collagen destruction, respectively. Histomorphometrical analysis was used to assess the inflammatory cell infiltration. Immunohistochemistry and tartrate-resistant acid phosphatase were used to detect receptor activator of nuclear factor kappa B ligand and osteoprotegerin expressions, and osteoclast activity in the gingiva and alveolar bone. The activation of nuclear factor-kappa B, production of tumor necrosis factor (TNF)-α and interleukin (IL)-1β, glycosylation of extracellular matrix metalloproteinase inducer, and production of matrix metalloproteinase (MMP)-2 and MMP-9 in the gingiva were assessed by Western blot. Puerarin at doses of 200 and 400 mg/kg significantly reduced the alveolar bone loss compared with the vehicle group. Collagen destruction and inflammatory cell infiltration were significantly less in the puerarin-treated group (200 mg/kg) compared with that of the vehicle group. Puerarin (200 mg/kg) also reduced the ratio of receptor activator of nuclear factor kappa B ligand/osteoprotegerin and osteoclast activity. Western blot analysis showed that puerarin (200 mg/kg) inhibited the activation of nuclear factor-kappa B p65, which is associated with lower IL-1β and TNF-α production, and reduced the glycosylation of extracellular matrix metalloproteinase inducer, which is associated with lower

  5. The density of collagen fiber in alveolus mandibular bone of rabbit after augmentation with powder demineralized bone matrix post incisivus extraction

    Directory of Open Access Journals (Sweden)

    Regina TC. Tandelilin

    2006-06-01

    Full Text Available The bone defect due to tooth extraction contributes the most cases reported in the aspects of oral surgery. The defect can be preventively managed by adding powder bone matrix intended for augmentation which eventually induces the formation of new bones. This hard tissue wound healing is preceded by the presence of collagen fibers. The aim of this study was to determine the density of collagen fiber in the alveolus mandibular bone of rabbit which was augmented using powder demineralized bone matrix (DBM post incisivus extraction. Twenty four male rabbits aged 2.5–3 months weighed 900–1,100 grams were randomly divided into two groups. The treated rabbits were augmented with DBM after the incisivus extraction on mandible. The mucosa was then sutured. On the other hand, the controlled rabbits received similar treatments with those of the treated rabbits except there was no augmentation of DBM. Decapitation of treated and controlled rabbits was made on day 5, 7, 10, and 14 days post surgery, each with three rabbits. Mandibles were cut, decalcified, and imbedded in paraffin block. The staining was done using Mallory. Significant differences in the density of collagen were noted on day 10 and 14 post surgery, indicating that powder demineralized bone matrix successfully induced the stimulation of collagen.

  6. Guided Bone Regeneration With or Without a Collagen Membrane in Rats with Induced Diabetes Mellitus: Histomorphometric and Immunolocalization Analysis of Angiogenesis and Bone Turnover Markers.

    Science.gov (United States)

    Jardini, Maria Aparecida; Tera, Tábata Mello; Meyer, Augusto Andrade; Moretto, Camilla Magnoni; Prado, Renata Falchete; Santamaria, Mauro Pedrine

    2016-01-01

    Diabetes mellitus (DM) affects the processes of repair, wound healing, and bone remodeling. This study was conducted to evaluate autologous bone graft integration, either with or without guided bone regeneration, through analyzing the expression of bone reabsorption markers and neovascularization in rats suffering from DM. Thirty adult Wistar rats were divided into two groups: The DM group received an injection of alloxan monohydrate (150 mg/kg), and the control group received an injection of sterile saline. Fifteen days afterward, an autologous bone grafting was performed in each of their arches, with the insertion of a membrane into the left arch. Euthanasia occurred in 7, 21, or 60 days after the surgery. Bone samples were processed for histomorphometric and immunohistochemical analyses. After a statistical analysis of the data, the presence of DM did not interfere negatively in the bone autograft repair. The collagen membrane favored the graft integration into the recipient bed and the bone neoformation around the graft. Greater vascularization was observed between 21 and 60 days after the surgery, which increased bone formation and resulted in the graft integration. Only the RANK marker showed a significant difference in the glycemic groups. Transglutaminase 2 was significant for the membrane presence and experimental time. It is hence concluded that diabetes mellitus does not interfere with bone reabsorption via the RANK/RANKL/OPG. The graft integration was similar between the groups; however, the results of hyperglycemia with the collagen membrane indicate greater bone growth after graft placement.

  7. Synergistic intrafibrillar/extrafibrillar mineralization of collagen scaffolds based on a biomimetic strategy to promote the regeneration of bone defects

    Directory of Open Access Journals (Sweden)

    Wang Y

    2016-05-01

    Full Text Available Yao Wang,1 Ngo Van Manh,1,2 Haorong Wang,1 Xue Zhong,1 Xu Zhang,1 Changyi Li1 1School of Dentistry, Hospital of Stomatology, Tianjin Medical University, Tianjin, People’s Republic of China; 2Thaibinh University of Medicine and Pharmacy, Thaibinh, Vietnam Abstract: The mineralization of collagen scaffolds can improve their mechanical properties and biocompatibility, thereby providing an appropriate microenvironment for bone regeneration. The primary purpose of the present study is to fabricate a synergistically intra- and extrafibrillar mineralized collagen scaffold, which has many advantages in terms of biocompatibility, biomechanical properties, and further osteogenic potential. In this study, mineralized collagen scaffolds were fabricated using a traditional mineralization method (ie, immersed in simulated body fluid as a control group and using a biomimetic method based on the polymer-induced liquid precursor process as an experimental group. In the polymer-induced liquid precursor process, a negatively charged polymer, carboxymethyl chitosan (CMC, was used to stabilize amorphous calcium phosphate (ACP to form nanocomplexes of CMC/ACP. Collagen scaffolds mineralized based on the polymer-induced liquid precursor process were in gel form such that nanocomplexes of CMC/ACP can easily be drawn into the interstices of the collagen fibrils. Scanning electron microscopy and transmission electron microscopy were used to examine the porous micromorphology and synergistic mineralization pattern of the collagen scaffolds. Compared with simulated body fluid, nanocomplexes of CMC/ACP significantly increased the modulus of the collagen scaffolds. The results of in vitro experiments showed that the cell count and differentiated degrees in the experimental group were higher than those in the control group. Histological staining and micro-computed tomography showed that the amount of new bone regenerated in the experimental group was larger than that in the

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    Host tissue response and heterotopic osteoinduction by composites of demineralized bone matrix and three different substances used as bioresorbable carriers implanted in the abdominal muscles were evaluated by strontium 85 uptake and histology 4 weeks postoperatively in 60 male Wistar rats. Both...... fibrin-collagen paste and fibrin sealant inhibited bone induction and produced a chronic inflammation; part of the fibrin-collagen paste was still present at 4 weeks. Polyorthoester with gentamicin was almost completely absorbed, induced minimal tissue reaction, and did not inhibit osteoinduction....

  9. Nanofibrous yet injectable polycaprolactone-collagen bone tissue scaffold with osteoprogenitor cells and controlled release of bone morphogenetic protein-2

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Gayathri; Bialorucki, Callan [Department of Bioengineering, College of Engineering, University of Toledo, Toledo, OH 43606 (United States); Yildirim-Ayan, Eda, E-mail: eda.yildirimayan@utoledo.edu [Department of Bioengineering, College of Engineering, University of Toledo, Toledo, OH 43606 (United States); Department of Orthopaedic Surgery, University of Toledo Medical Center, Toledo, OH 43614 (United States)

    2015-06-01

    In this work, we developed a nanofibrous, yet injectable orthobiologic tissue scaffold that is capable of hosting osteoprogenitor cells and controlling kinetic release profile of the encapsulated pro-osteogenic factor without diminishing its bioactivity over 21 days. This innovative injectable scaffold was synthesized by incorporating electrospun and subsequently O{sub 2} plasma-functionalized polycaprolactone (PCL) nanofibers within the collagen type-I solution along with MC3T3-E1 cells (pre-osteoblasts) and bone morphogenetic protein-2 (BMP2). Through changing the PCL nanofiber concentration within the injectable scaffolds, we were able to tailor the mechanical strength, protein retention capacity, bioactivity preservation, and osteoinductive potential of the scaffolds. The nanofibrous internal structure of the scaffold allowed us to use a low dose of BMP2 (200 ng/ml) to achieve osteoblastic differentiation in in vitro culture. The osteogenesis capacity of the injectable scaffolds were evaluated though measuring MC3T3-E1 cell proliferation, ALP activity, matrix mineralization, and early- and late-osteoblast specific gene expression profiles over 21 days. The results demonstrated that the nanofibrous injectable scaffold provides not only an osteoinductive environment for osteoprogenitor cells to differentiate, but also a suitable biomechanical and biochemical environment to act as a reservoir for osteogenic factors with controlled release profile. - Highlights: • Injectable nanofibrous scaffold with osteoprogenitor cells and BMP2 was synthesized. • PCL nanofiber concentration within collagen scaffold affected the BMP2 retention and bioactivity. • Optimal PCL concentration was identified for mechanical stability, injectability, and osteogenic activity. • Scaffolds exhibited long-term osteoinductive capacity for bone repair and regeneration.

  10. Zebrafish Collagen Type I: Molecular and Biochemical Characterization of the Major Structural Protein in Bone and Skin

    Science.gov (United States)

    Gistelinck, C.; Gioia, R.; Gagliardi, A.; Tonelli, F.; Marchese, L.; Bianchi, L.; Landi, C.; Bini, L.; Huysseune, A.; Witten, P. E.; Staes, A.; Gevaert, K.; De Rocker, N.; Menten, B.; Malfait, F.; Leikin, S.; Carra, S.; Tenni, R.; Rossi, A.; De Paepe, A.; Coucke, P.; Willaert, A.; Forlino, A.

    2016-01-01

    Over the last years the zebrafish imposed itself as a powerful model to study skeletal diseases, but a limit to its use is the poor characterization of collagen type I, the most abundant protein in bone and skin. In tetrapods collagen type I is a trimer mainly composed of two α1 chains and one α2 chain, encoded by COL1A1 and COL1A2 genes, respectively. In contrast, in zebrafish three type I collagen genes exist, col1a1a, col1a1b and col1a2 coding for α1(I), α3(I) and α2(I) chains. During embryonic and larval development the three collagen type I genes showed a similar spatio-temporal expression pattern, indicating their co-regulation and interdependence at these stages. In both embryonic and adult tissues, the presence of the three α(I) chains was demonstrated, although in embryos α1(I) was present in two distinct glycosylated states, suggesting a developmental-specific collagen composition. Even though in adult bone, skin and scales equal amounts of α1(I), α3(I) and α2(I) chains are present, the presented data suggest a tissue-specific stoichiometry and/or post-translational modification status for collagen type I. In conclusion, this data will be useful to properly interpret results and insights gained from zebrafish models of skeletal diseases. PMID:26876635

  11. Sika Deer Antler Collagen Type I-Accelerated Osteogenesis in Bone Marrow Mesenchymal Stem Cells via the Smad Pathway

    Directory of Open Access Journals (Sweden)

    Na Li

    2016-01-01

    Full Text Available Deer antler preparations have been used to strengthen bones for centuries. It is particularly rich in collagen type I. This study aimed to unravel part of the purported bioremedial effect of Sika deer antler collagen type I (SDA-Col I on bone marrow mesenchymal stem cells. The results suggest that SDA-Col I might be used to promote and regulate osteoblast proliferation and differentiation. SDA-Col I might potentially provide the basis for novel therapeutic strategies in the treatment of bone injury and/or in scaffolds for bone replacement strategies. Finally, isolation of SDA-Col I from deer antler represents a renewable, green, and uncomplicated way to obtain a biomedically valuable therapeutic.

  12. Identification of a new hominin bone from Denisova Cave, Siberia using collagen fingerprinting and mitochondrial DNA analysis

    Science.gov (United States)

    Brown, Samantha; Higham, Thomas; Slon, Viviane; Pääbo, Svante; Meyer, Matthias; Douka, Katerina; Brock, Fiona; Comeskey, Daniel; Procopio, Noemi; Shunkov, Michael; Derevianko, Anatoly; Buckley, Michael

    2016-03-01

    DNA sequencing has revolutionised our understanding of archaic humans during the Middle and Upper Palaeolithic. Unfortunately, while many Palaeolithic sites contain large numbers of bones, the majority of these lack the diagnostic features necessary for traditional morphological identification. As a result the recovery of Pleistocene-age human remains is extremely rare. To circumvent this problem we have applied a method of collagen fingerprinting to more than 2000 fragmented bones from the site of Denisova Cave, Russia, in order to facilitate the discovery of human remains. As a result of our analysis a single hominin bone (Denisova 11) was identified, supported through in-depth peptide sequencing analysis, and found to carry mitochondrial DNA of the Neandertal type. Subsequent radiocarbon dating revealed the bone to be >50,000 years old. Here we demonstrate the huge potential collagen fingerprinting has for identifying hominin remains in highly fragmentary archaeological assemblages, improving the resources available for wider studies into human evolution.

  13. New biochemical markers of bone resorption derived from collagen breakdown in the study of postmenopausal osteoporosis.

    Science.gov (United States)

    Guerrero, R; Diaz Martin, M A; Diaz Diego, E M; Disla, T; Rapado, A; de la Piedra, C

    1996-01-01

    The aim of this work was to perform a comparative study between three recently developed biochemical markers of bone resorption derived from collagen metabolism--(1) total urinary free pyridinolines (Pyr), (2) serum pyridinoline cross-linked carboxy-terminal telopeptides of type I collagen (ICTP) and (3) a urinary-specific sequence for a part of the C-telopeptide of the alpha 1 chain of type I collagen (CTX)--in the diagnosis and follow-up of postmenopausal osteoporosis. Results were also evaluated relative to the classical biochemical marker urinary hydroxyproline (Hyp). The study included 20 untreated osteoporotic postmenopausal women (OSP), age 60 +/- 6 years, range 46-69 years; 27 osteoporotic postmenopausal women treated (OSP-T) by cyclic therapy with disodium etidronate, 25-hydroxyvitamin D and calcium for a period between 3 months and 4 years (25 +/- 15 months), age 59 +/- 7 years, range 41-67 years; 17 osteopenic postmenopausal women, age 57 +/- 6 years, range 46 +/- 68 years; and 29 healthy control postmenopausal women, age 56 +/- 7 years, range 41-70 years. The diagnostic criterion for postmenopausal osteoporosis was a bone mineral density (BMD) (Hologic QDR-1000) in lumbar spine and/or femoral neck more than 2 SD below the mean value corresponding to an age- and sex-matched healthy control group. For inclusion in the osteopenic group BMD values had to be between 1 and 2 SD below the mean BMD value corresponding to the control group. We found a significant increase (p < 0.01) in the levels of Pyr/Cr and CTX/Cr (Cr = creatinine) in OSP patients with respect to the control group and we did not observe any significant difference between control and OSP-T or osteopenic women. It is interesting to note that there was a mean increase in CTX/Cr in OSP patients of 101% of the control values, while the mean increase found in Pyr/Cr concentration was only 33%. However, we did not find significant differences in the concentrations of ICTP and Hyp/Cr between groups

  14. Piezoelectric Collagen Hydrogels

    Indian Academy of Sciences (India)

    ... Collagen Hydrogels. Stress-induced potential in bone is produced by shear piezoelectricity in collagen fibers and streaming potential in canaliculae. The growth of bone is regulated to best resist external force. Piezo electrical property of collagen has come to be gainfully manipulated in collagen based biomaterial devices.

  15. Calcium phosphate fibers coated with collagen: In vivo evaluation of the effects on bone repair.

    Science.gov (United States)

    Ueno, Fabio Roberto; Kido, Hueliton Wilian; Granito, Renata Neves; Gabbai-Armelin, Paulo Roberto; Magri, Angela Maria Paiva; Fernandes, Kelly Rosseti; da Silva, Antonio Carlos; Braga, Francisco José Correa; Renno, Ana Claudia Muniz

    2016-08-12

    The aim of this study was to assess the characteristics of the CaP/Col composites, in powder and fiber form, via scanning electron microscopy (SEM), pH and calcium release evaluation after immersion in SBF and to evaluate the performance of these materials on the bone repair process in a tibial bone defect model. For this, four different formulations (CaP powder - CaPp, CaP powder with collagen - CaPp/Col, CaP fibers - CaPf and CaP fibers with collagen - CaPf/Col) were developed. SEM images indicated that both material forms were successfully coated with collagen and that CaPp and CaPf presented HCA precursor crystals on their surface. Although presenting different forms, FTIR analysis indicated that CaPp and CaPf maintained the characteristic peaks for this class of material. Additionally, the calcium assay study demonstrated a higher Ca uptake for CaPp compared to CaPf for up to 5 days. Furthermore, pH measurements revealed that the collagen coating prevented the acidification of the medium, leading to higher pH values for CaPp/Col and CaPf/Col. The histological analysis showed that CaPf/Col demonstrated a higher amount of newly formed bone in the region of the defect and a reduced presence of material. In summary, the results indicated that the fibrous CaP enriched with the organic part (collagen) glassy scaffold presented good degradability and bone-forming properties and also supported Runx2 and RANKL expression. These results show that the present CaP/Col fibrous composite may be used as a bone graft for inducing bone repair.

  16. Human mandible bone defect repair by the grafting of dental pulp stem/progenitor cells and collagen sponge biocomplexes

    OpenAIRE

    R d’Aquino; A De Rosa; V Lanza; V Tirino; L Laino; A Graziano; V Desiderio; G Laino; G Papaccio

    2009-01-01

    In this study we used a biocomplex constructed from dental pulp stem/progenitor cells (DPCs) and a collagen sponge scaffold for oro-maxillo-facial (OMF) bone tissue repair in patients requiring extraction of their third molars. The experiments were carried out according to our Internal Ethical Committee Guidelines and written informed consent was obtained from the patients. The patients presented with bilateral bone reabsorption of the alveolar ridge distal to the second molar secondary to im...

  17. Ribose mediated crosslinking of collagen-hydroxyapatite hybrid scaffolds for bone tissue regeneration using biomimetic strategies.

    Science.gov (United States)

    Krishnakumar, Gopal Shankar; Gostynska, Natalia; Campodoni, Elisabetta; Dapporto, Massimiliano; Montesi, Monica; Panseri, Silvia; Tampieri, Anna; Kon, Elizaveta; Marcacci, Maurilio; Sprio, Simone; Sandri, Monica

    2017-08-01

    This study explores for the first time the application of ribose as a highly biocompatible agent for the crosslinking of hybrid mineralized constructs, obtained by bio-inspired mineralization of self-assembling Type I collagen matrix with magnesium-doped-hydroxyapatite nanophase, towards a biomimetic mineralized 3D scaffolds (MgHA/Coll) with excellent compositional and structural mimicry of bone tissue. To this aim, two different crosslinking mechanisms in terms of pre-ribose glycation (before freeze drying) and post-ribose glycation (after freeze drying) were investigated. The obtained results explicate that with controlled freeze-drying, highly anisotropic porous structures with opportune macro-micro porosity are obtained. The physical-chemical features of the scaffolds characterized by XRD, FTIR, ICP and TGA demonstrated structural mimicry analogous to the native bone. The influence of ribose greatly assisted in decreasing solubility and increased enzymatic resistivity of the scaffolds. In addition, enhanced mechanical behaviour in response to compressive forces was achieved. Preliminary cell culture experiments reported good cytocompatibility with extensive cell adhesion, proliferation and colonization. Overall, scaffolds developed by pre-ribose glycation process are preferred, as the related crosslinking technique is more facile and robust to obtain functional scaffolds. As a proof of concept, we have demonstrated that ribose crosslinking is cost-effective, safe and functionally effective. This study also offers new insights and opportunities in developing promising scaffolds for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

    Energy Technology Data Exchange (ETDEWEB)

    Beck, L., E-mail: lucile.beck@cea.fr [C2RMF - UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); CEA, DEN, Service de Recherches de Metallurgie Physique, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Cuif, J.-P. [UMR IDES 8148, Universite Paris XI-Orsay, 91405 Orsay cedex (France); Pichon, L. [C2RMF - UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Vaubaillon, S. [CEA, INSTN, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Dambricourt Malasse, A. [Departement de Prehistoire, Museum national d' Histoire naturelle, UMR 7194 - CNRS, Institut de Paleontologie Humaine, 1, rue Rene Panhard, 75013 Paris (France); Abel, R.L. [The Natural History Museum, London (United Kingdom)

    2012-02-15

    The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by {sup 14}C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon-Hydrogen-Nitrogen analyzer for measuring C and N before {sup 14}C dating.

  19. Functionalization of a Collagen-Hydroxyapatite Scaffold with Osteostatin to Facilitate Enhanced Bone Regeneration.

    Science.gov (United States)

    Quinlan, Elaine; Thompson, Emmet M; Matsiko, Amos; O'Brien, Fergal J; López-Noriega, Adolfo

    2015-12-09

    Defects within bones caused by trauma and other pathological complications may often require the use of a range of therapeutics to facilitate tissue regeneration. A number of approaches have been widely utilized for the delivery of such therapeutics via physical encapsulation or chemical immobilization suggesting significant promise in the healing of bone defects. The study focuses on the chemical immobilization of osteostatin, a pentapeptide of the parathyroid hormone (PTHrP107-111), within a collagen-hydroxyapatite scaffold. The chemical attachment method via crosslinking supports as little as 4% release of the peptide from the scaffolds after 21 d whereas non-crosslinking leads to 100% of the peptide being released by as early as 4 d. In vitro characterization demonstrates that this cross-linking method of immobilization supports a pro-osteogenic effect on osteoblasts. Most importantly, when implanted in a critical-sized calvarial defect within a rat, these scaffolds promote significantly greater new bone volume and area compared to nonfunctionalized scaffolds (**p < 0.01) and an empty defect control (***p < 0.001). Collectively, this study suggests that such an approach of chemical immobilization offers greater spatiotemporal control over growth factors and can significantly modulate tissue regeneration. Such a system may be adopted for a range of different proteins and thus offers the potential for the treatment of various complex pathologies that require localized mediation of drug delivery. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

    International Nuclear Information System (INIS)

    Beck, L.; Cuif, J.-P.; Pichon, L.; Vaubaillon, S.; Dambricourt Malassé, A.; Abel, R.L.

    2012-01-01

    The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by 14 C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon–Hydrogen–Nitrogen analyzer for measuring C and N before 14 C dating.

  1. Guided Bone Regeneration with Collagen Membranes and Particulate Graft Materials: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Wessing, Bastian; Lettner, Stefan; Zechner, Werner

    The aim of this meta-analysis was to evaluate different methods for guided bone regeneration using collagen membranes and particulate grafting materials in implant dentistry. An electronic database search and hand search were performed for all relevant articles dealing with guided bone regeneration in implant dentistry published between 1980 and 2014. Only randomized clinical trials and prospective controlled studies were included. The primary outcomes of interest were survival rates, membrane exposure rates, bone gain/defect reduction, and vertical bone loss at follow-up. A meta-analysis was performed to determine the effects of presence of membrane cross-linking, timing of implant placement, membrane fixation, and decortication. Twenty studies met the inclusion criteria. Implant survival rates were similar between simultaneous and subsequent implant placement. The membrane exposure rate of cross-linked membranes was approximately 30% higher than that of non-cross-linked membranes. The use of anorganic bovine bone mineral led to sufficient newly regenerated bone and high implant survival rates. Membrane fixation was weakly associated with increased vertical bone gain, and decortication led to higher horizontal bone gain (defect depth). Guided bone regeneration with particulate graft materials and resorbable collagen membranes is an effective technique for lateral alveolar ridge augmentation. Because implant survival rates for simultaneous and subsequent implant placement were similar, simultaneous implant placement is recommended when possible. Additional techniques like membrane fixation and decortication may represent beneficial implications for the practice.

  2. Preparation and evaluation of collagen-silk fibroin/hydroxyapatite nanocomposites for bone tissue engineering.

    Science.gov (United States)

    Chen, Li; Hu, Jingxiao; Ran, Jiabing; Shen, Xinyu; Tong, Hua

    2014-04-01

    A new in situ precipitation technique was developed to synthesize collagen-silk fibroin/hydroxyapatite nanocomposites. The componential properties and morphological of nanocomposites were investigated. It was revealed that the inorganic phase in the nanocomposite was carbonate-substituted hydroxyapatite with low crystallinity. Morphology studies showed that hydroxyapatite particles with size ranging from 30 to 100 nm were distributed uniformly in the polymer matrix. According to the TEM micrographs, inorganic particles were composed of more fine sub-particles whose diameters were between 2 and 5 nm in size without regular crystallographic orientation. The mechanical properties of the composites were evaluated by measuring their elastic modulus. The data indicated that the elastic modulus of nanocomposites was improved by the addition of silk fibroin. Finally, the cell biocompatibility of the composites was tested in vitro, which showed that they have good biocompatibility. These results suggest that the collagen-silk fibroin/hydroxyapatite nanocomposites are promising biomaterials for bone tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2011-01-01

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

  4. A collagen-hydroxyapatite scaffold allows for binding and co-delivery of recombinant bone morphogenetic proteins and bisphosphonates.

    Science.gov (United States)

    Murphy, Ciara M; Schindeler, Aaron; Gleeson, John P; Yu, Nicole Y C; Cantrill, Laurence C; Mikulec, Kathy; Peacock, Lauren; O'Brien, Fergal J; Little, David G

    2014-05-01

    An emerging paradigm in orthopedics is that a bone-healing outcome is the product of the anabolic (bone-forming) and catabolic (bone-resorbing) outcomes. Recently, surgical and tissue engineering strategies have emerged that combine recombinant human bone morphogenetic proteins (rhBMPs) and bisphosphonates (BPs) in order to maximize anabolism and minimize catabolism. Collagen-based scaffolds that are the current surgical standard can bind rhBMPs, but not BPs. We hypothesized that a biomimetic collagen-hydroxyapatite (CHA) scaffold would bind both agents and produce superior in vivo outcomes. Consistent with this concept, in vitro elution studies utilizing rhBMP-2 ELISA assays and scintillation counting of (14)C-radiolabeled zoledronic acid (ZA) confirmed delayed release of both agents from the CHA scaffold. Next, scaffolds were tested for their capacity to form ectopic bone after surgical implantation into the rat hind limb. Using CHA, a significant 6-fold increase in bone volume was seen in rhBMP-2/ZA groups compared to rhBMP-2 alone, confirming the ability of ZA to enhance rhBMP-2 bone formation. CHA scaffolds were found to be capable of generating mineralized tissue in the absence of rhBMP-2. This study has implications for future clinical treatments of critical bone defects. It demonstrates the relative advantages of co-delivering anabolic and anti-catabolic agents using a multicomponent scaffold system. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  5. Bioinspired synthesis of hydroxyapatite nanocrystals in the presence of collagen and l-arginine: Candidates for bone regeneration.

    Science.gov (United States)

    Brasinika, Despoina; Tsigkou, Olga; Tsetsekou, Athena; Missirlis, Yiannis F

    2016-04-01

    This work aims at the bioinspired synthesis of hydroxyapatite (HAp) crystals in the presence of both collagen and l-arginine, in an effort to obtain a homogeneous hybrid material, having a bone-like nanostructure. Collagen (Col) is the most commonly utilized protein in most species of life, while L-arginine (Arg) encourages cell attachment, proliferation, and differentiation on HAp surfaces. Transmission electron microscopy, X-ray diffraction and Fourier transform-infrared spectroscopy were used to analyze surface morphology and structure of nanocrystals obtained under different synthesis conditions. It was shown that collagen and arginine content affect HAp crystallization. Collagen has an inhibition effect since HAp crystal size is reduced with the increase of collagen content. The presence of arginine is crucial as a critical content exists (Ca(2+):Arg = 1:1) under which HAp nanocrystals coexist with brushite. Under the optimum synthesis conditions (HAp/Col weight ratio 70/30 and Ca(2+):Arg molar ratio 1:1) HAp nanoplates of a uniform size (around 10 × 10 nm) were obtained. The biocompatibility of this hybrid powder was assessed using human bone marrow derived mesenchymal stem cells (MSCs). Cell response in terms of MSC attachment (scanning electron microscopy) and viability/proliferation (Alamar Blue) demonstrated a noncytotoxic effect of the new material. © 2015 Wiley Periodicals, Inc.

  6. Resolving the bulk δ 15N values of ancient human and animal bone collagen via compound-specific nitrogen isotope analysis of constituent amino acids

    Science.gov (United States)

    Styring, Amy K.; Sealy, Judith C.; Evershed, Richard P.

    2010-01-01

    Stable nitrogen isotope analysis is a fundamental tool in assessing dietary preferences and trophic positions within contemporary and ancient ecosystems. In order to assess more fully the dietary contributions to human tissue isotope values, a greater understanding of the complex biochemical and physiological factors which underpin bulk collagen δ 15N values is necessary. Determinations of δ 15N values of the individual amino acids which constitute bone collagen are necessary to unravel these relationships, since different amino acids display different δ 15N values according to their biosynthetic origins. A range of collagen isolates from archaeological faunal and human bone ( n = 12 and 11, respectively), representing a spectrum of terrestrial and marine protein origins and diets, were selected from coastal and near-coastal sites at the south-western tip of Africa. The collagens were hydrolysed and δ 15N values of their constituent amino acids determined as N-acetylmethyl esters (NACME) via gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The analytical approach employed accounts for 56% of bone collagen nitrogen. Reconstruction of bulk bone collagen δ 15N values reveals a 2‰ offset from bulk collagen δ 15N values which is attributable to the δ 15N value of the amino acids which cannot currently be determined by GC-C-IRMS, notably arginine which comprises 53% of the nitrogen unaccounted for (23% of the total nitrogen). The δ 15N values of individual amino acids provide insights into both the contributions of various amino acids to the bulk δ 15N value of collagen and the factors influencing trophic position and the nitrogen source at the base of the food web. The similarity in the δ 15N values of alanine, glutamate, proline and hydroxyproline reflects the common origin of their amino groups from glutamate. The depletion in the δ 15N value of threonine with increasing trophic level indicates a fundamental difference between

  7. Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro.

    Science.gov (United States)

    Tamaddon, M; Burrows, M; Ferreira, S A; Dazzi, F; Apperley, J F; Bradshaw, A; Brand, D D; Czernuszka, J; Gentleman, E

    2017-03-03

    Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS - which was released from scaffolds quickly - significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA.

  8. Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro

    Science.gov (United States)

    Tamaddon, M.; Burrows, M.; Ferreira, S. A.; Dazzi, F.; Apperley, J. F.; Bradshaw, A.; Brand, D. D.; Czernuszka, J.; Gentleman, E.

    2017-03-01

    Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS - which was released from scaffolds quickly - significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA.

  9. The effects of Paraloid B-72 and Butvar B-98 treatment and organic solvent removal on δ(13)C, δ(15)N, and δ(18)O values of collagen and hydroxyapatite in a modern bone.

    Science.gov (United States)

    France, Christine A M; Giaccai, Jennifer A; Doney, Charlotte R

    2015-06-01

    Stable isotopes in bones are a powerful tool for diet, provenance, climate, and physiological reconstructions, but necessarily require well-preserved specimens unaltered by postmortem diagenesis or conservation practices. This study examines the effects of Paraloid B-72 and Butvar B-98, two common consolidants used in field and museum conservation, on δ(13)C, δ(15)N, and δ(18)O values from bone collagen and hydroxyapatite. The effects of solvent removal (100% acetone, 100% ethanol, 9:1 acetone:xylenes, 9:1 ethanol:xylenes) and drying methods (ambient air, vacuum, oven drying at 80°C) were also examined to determine if bones treated with these consolidants can successfully be cleaned and used for stable isotope analyses. Results show that introduction of Paraloid B-72 or Butvar B-98 in 100% acetone or 100% ethanol, respectively, with subsequent removal by the same solvents and drying at 80°C facilitates the most successful removal of consolidants and solvents. The δ(13)C values in collagen, δ(15)N in collagen, δ(18)O in hydroxyapatite phosphate, and δ(13)C in hydroxyapatite structural carbonate were unaltered by treatments with Paraloid or Butvar and subsequent solvent removal. The δ(18)O in hydroxyapatite structural carbonate showed nonsystematic variability when bones were treated with Paraloid and Butvar, which is hypothesized to be a result of hydroxyl exchange when bones are exposed to consolidants in solution. It is therefore recommended that δ(18)O in hydroxyapatite structural carbonate should not be used in stable isotope studies if bones have been treated with Paraloid or Butvar. © 2015 Wiley Periodicals, Inc.

  10. Bone fracture toughness and strength correlate with collagen cross-link maturity in a dose-controlled lathyrism mouse model.

    Science.gov (United States)

    McNerny, Erin M B; Gong, Bo; Morris, Michael D; Kohn, David H

    2015-03-01

    Collagen cross-linking is altered in many diseases of bone, and enzymatic collagen cross-links are important to bone quality, as evidenced by losses of strength after lysyl oxidase inhibition (lathyrism). We hypothesized that cross-links also contribute directly to bone fracture toughness. A mouse model of lathyrism using subcutaneous injection of up to 500 mg/kg β-aminopropionitrile (BAPN) was developed and characterized (60 animals across 4 dosage groups). Three weeks of 150 or 350 mg/kg BAPN treatment in young, growing mice significantly reduced cortical bone fracture toughness, strength, and pyridinoline cross-link content. Ratios reflecting relative cross-link maturity were positive regressors of fracture toughness (HP/[DHLNL + HLNL] r(2)  = 0.208, p toughness and strength. Thus, cross-link profile perturbations associated with bone disease may provide insight into bone mechanical quality and fracture risk. © 2014 American Society for Bone and Mineral Research.

  11. Orientation of mineral crystals by collagen fibers during in vivo bone engineering: An X-ray diffraction imaging study

    International Nuclear Information System (INIS)

    Cedola, A.; Mastrogiacomo, M.; Lagomarsino, S.; Cancedda, R.; Giannini, C.; Guagliardi, A.; Ladisa, M.; Burghammer, M.; Rustichelli, F.; Komlev, V.

    2007-01-01

    The mechanism of mineralized bone matrix deposition was investigated taking advantage of a tissue engineering approach in which bone tissue is formed when porous ceramic scaffold is loaded with bone marrow stromal cells and implanted in vivo. The aim of our study is to point out the interaction between the newly formed mineral crystals and the scaffold imposing the three-dimensional desired architecture to the growing bone. High spatial resolution Small Angle X-ray Scattering measurements obtained using synchrotron radiation and X-ray waveguide as optical element allowed a local structural study at the bone-scaffold interface. Using an original methodology for data analysis, we obtained a two-dimensional microscopic map of the mineralization degree, the collagen presence and the mineral orientation degree around the scaffold pore

  12. Effects of rhBMP-2 Loaded Titanium Reinforced Collagen Membranes on Horizontal Bone Augmentation in Dogs

    Directory of Open Access Journals (Sweden)

    Ki-Sun Lee

    2017-01-01

    Full Text Available The aim of this study was to evaluate the efficacy of growth factor loaded collagen membranes on new bone formation during horizontal bone augmentation. Mandibular defects (4 × 4 × 4 mm were surgically prepared in six male beagle dogs, which were then protected with one of three types of membranes: (1 titanium mesh, (2 titanium reinforced collagen, or (3 rhBMP-2 loaded titanium reinforced collagen. Animals were euthanized 8 and 16 weeks after surgery, and nondecalcified specimens were prepared and histomorphologically investigated to determine the degree of osteogenesis. Data were analyzed with Friedman test. With respect to the degree of osteogenesis at earlier stage (8 weeks after surgery, there was significantly higher new bone ratio in rhBMP-2 loaded membrane group (p>0.05. However, with respect to the long-term results (16 weeks after surgery, there were no significant differences among the three membranes (p>0.05. Based on histomorphometric analysis, there were no significant differences in horizontal bone gaining ratio (p>0.05.

  13. Human mandible bone defect repair by the grafting of dental pulp stem/progenitor cells and collagen sponge biocomplexes

    Directory of Open Access Journals (Sweden)

    R d’Aquino

    2009-11-01

    Full Text Available In this study we used a biocomplex constructed from dental pulp stem/progenitor cells (DPCs and a collagen sponge scaffold for oro-maxillo-facial (OMF bone tissue repair in patients requiring extraction of their third molars. The experiments were carried out according to our Internal Ethical Committee Guidelines and written informed consent was obtained from the patients. The patients presented with bilateral bone reabsorption of the alveolar ridge distal to the second molar secondary to impaction of the third molar on the cortical alveolar lamina, producing a defect without walls, of at least 1.5 cm in height. This clinical condition does not permit spontaneous bone repair after extraction of the third molar, and eventually leads to loss also of the adjacent second molar. Maxillary third molars were extracted first for DPC isolation and expansion. The cells were then seeded onto a collagen sponge scaffold and the obtained biocomplex was used to fill in the injury site left by extraction of the mandibular third molars. Three months after autologous DPC grafting, alveolar bone of patients had optimal vertical repair and complete restoration of periodontal tissue back to the second molars, as assessed by clinical probing and X-rays. Histological observations clearly demonstrated the complete regeneration of bone at the injury site. Optimal bone regeneration was evident one year after grafting. This clinical study demonstrates that a DPC/collagen sponge biocomplex can completely restore human mandible bone defects and indicates that this cell population could be used for the repair and/or regeneration of tissues and organs.

  14. Structural and mechanical differences between collagen homo- and heterotrimers: relevance for the molecular origin of brittle bone disease.

    Science.gov (United States)

    Chang, Shu-Wei; Shefelbine, Sandra J; Buehler, Markus J

    2012-02-08

    Collagen constitutes one-third of the human proteome, providing mechanical stability, elasticity, and strength to organisms. Normal type I collagen is a heterotrimer triple-helical molecule consisting of two α-1 chains and one α-2 chain. The homotrimeric isoform of type I collagen, which consists of three α-1 chains, is only found in fetal tissues, fibrosis, and cancer in humans. A mouse model of the genetic brittle bone disease, osteogenesis imperfect, oim, is characterized by a replacement of the α-2 chain by an α-1 chain, resulting also in a homotrimer collagen molecule. Experimental studies of oim mice tendon and bone have shown reduced mechanical strength compared to normal mice. The relationship between the molecular content and the decrease in strength is, however, still unknown. Here, fully atomistic simulations of a section of mouse type I heterotrimer and homotrimer collagen molecules are developed to explore the effect of the substitution of the α-2 chain. We calculate the persistence length and carry out a detailed analysis of the structure to determine differences in structural and mechanical behavior between hetero- and homotrimers. The results show that homotrimer persistence length is half of that of the heterotrimer (96 Å vs. 215 Å), indicating it is more flexible and confirmed by direct mechanical testing. Our structural analyses reveal that in contrast to the heterotrimer, the homotrimer easily forms kinks and freely rotates with angles much larger than heterotrimer. These local kinks may explain the larger lateral distance between collagen molecules seen in the fibrils of oim mice tendon and could have implications for reducing the intermolecular cross-linking, which is known to reduce the mechanical strength. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  15. Toward guided tissue and bone regeneration: morphology, attachment, proliferation, and migration of cells cultured on collagen barrier membranes. A systematic review.

    NARCIS (Netherlands)

    Behring, J.; Junker, R.; Walboomers, X.F.; Chessnut, B.; Jansen, J.A.

    2008-01-01

    Collagen barrier membranes are frequently used in both guided tissue regeneration (GTR) and guided bone regeneration (GBR). Collagen used for these devices is available from different species and is often processed to alter the properties of the final product. This is necessary because unprocessed

  16. Bone morphogenetic protein (BMP)-2 enhances the expression of type II collagen and aggrecan in chondrocytes embedded in alginate beads.

    Science.gov (United States)

    Gründer, Tatiana; Gaissmaier, Christoph; Fritz, Jürgen; Stoop, Reinout; Hortschansky, Peter; Mollenhauer, Jürgen; Aicher, Wilhelm K

    2004-07-01

    For autologous chondrocyte transplantation (ACT) chondrocytes are expanded in vitro. During expansion these cells may dedifferentiate. This change in phenotype is characterized by a raised expression of type I collagen and a decrease in type II collagen expression. Since high expression of type II collagen is of central importance for the properties of hyaline cartilage, we investigated if the growth factor bone morphogenetic protein-2 (BMP-2) may modulate the chondrogenic phenotype in monolayer cell cultures and in three-dimensional culture systems. Chondrocytes from articular knee cartilage of 11 individuals (average age: 39.8 years) with no history of joint disease were isolated and seeded either in monolayer cultures or embedded in alginate beads in presence or absence of human recombinant BMP-2 (hr-BMP-2). Then, cells were harvested and analysis of the chondrogenic phenotype was performed using quantitative RT-PCR, immunocytochemistry and ELISA. Addition of BMP-2 to chondrocytes expanded in two-dimensional (2D) cultures during the first subculture (P1) had no effect on mRNA amounts encoding type II collagen and interleukin-1beta (IL-1beta). In contrast, seeding chondrocytes in three-dimensional (3D) alginate cultures raised type II collagen expression significantly and addition of BMP-2 enhanced this effect. We conclude that chondrocytes during expansion for ACT may benefit from BMP-2 activation only when seeded in an appropriate 3D culture system. Copyright 2004 OsteoArthritis Research Society International

  17. [Development of a novel absorbable nanofiber chitosan-collagen membrane by electrospinning and the preliminary study on guided bone regeneration].

    Science.gov (United States)

    Gao, B; Li, X J; Lin, M; Li, Y Y; Dong, Y

    2018-02-09

    Objective: To evaluate the application effect of nanofiber chitosan-collagen membrane (NCM) on guided bone regeneration (GBR). Methods: The mixture of collagen, chitosan, polyethylene oxide was used to make up the NCM by electrospinning, then the NCM was crosslinked by glutaraldehyde vapor. The physical property of the NCM was measured by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). MC3T3-E1 osteoblasts were cultured on NCM to characterize the biocompatibility. The effectiveness of four groups [contrast group, Bio-gide membrane (BGM), compressed chitosan-collagen menbrane (CCM), NCM/CCM] on bone regeneration were evaluated in critical-sized defects (diameter = 5 mm) in SD rats. Results: When the mixed solution consists of 4.0% collagen, 1.0% chitosan and 3.5% polyethylene oxide, the NCM could be validly fabricated by electrospinning. After cross-linking by glutaraldehyde vapor, the tensile strength and the stability of NCM in damp was enhanced. No cytotoxicity of the NCM was detected on MC3T3-E1 osteoblasts. In vivo study showed that the new bone regeneration ratio of NCM/CCM group was [(43.10±1.49)%], and this was similar to that of the group of BGM [(41.36±2.60)%] ( P> 0.05), but higher than that of the CCM group [(33.10±1.41)%] and the contrast group [(7.22±2.46)%] ( P< 0.05). Conclusions: The NCM can promote new bone regeneration effectively in GBR procedure.

  18. Variations in glutamine deamidation for a Châtelperronian bone assemblage as measured by peptide mass fingerprinting of collagen

    DEFF Research Database (Denmark)

    Welker, Frido; Soressi, Marie A.; Roussel, Morgan

    2017-01-01

    AbstractPeptide mass fingerprinting of bone collagen (ZooMS) has previously been proposed as a method to calculate the extent of the non-enzymatic degradation of glutamine into glutamic acid (deamidation). Temporal and spatial variation of glutamine deamidation at a single site, however, has...... not been investigated. Here we apply ZooMS screening of Châtelperronian and Early Holocene bone specimens from Quinçay, France, to explore temporal and spatial variation in glutamine deamidation. Our results indicate that chronological resolution is low, while spatial variation is high. Nevertheless, our...

  19. Modified silk fibroin scaffolds with collagen/decellularized pulp for bone tissue engineering in cleft palate: Morphological structures and biofunctionalities

    Energy Technology Data Exchange (ETDEWEB)

    Sangkert, Supaporn [Biological Materials for Medicine Research Unit, Faculty of Medicine, Institute of Biomedical Engineering, Prince of Songkla University, Hat Yai, Songkhla90110 (Thailand); Meesane, Jirut, E-mail: jirutmeesane999@yahoo.co.uk [Biological Materials for Medicine Research Unit, Faculty of Medicine, Institute of Biomedical Engineering, Prince of Songkla University, Hat Yai, Songkhla90110 (Thailand); Kamonmattayakul, Suttatip [Faculty of Dentistry, Department of Preventive Dentistry, Prince of Songkla University, Hat Yai, Songkhla90110 (Thailand); Chai, Wen Lin [Faculty of Dentistry, Department of General Dental Practice and Oral and Maxillofacial Imaging, University of Malaya, Kuala Lumpur (Malaysia)

    2016-01-01

    Cleft palate is a congenital malformation that generates a maxillofacial bone defect around the mouth area. The creation of performance scaffolds for bone tissue engineering in cleft palate is an issue that was proposed in this research. Because of its good biocompatibility, high stability, and non-toxicity, silk fibroin was selected as the scaffold of choice in this research. Silk fibroin scaffolds were prepared by freeze-drying before immerging in a solution of collagen, decellularized pulp, and collagen/decellularized pulp. Then, the immersed scaffolds were freeze-dried. Structural organization in solution was observed by Atomic Force Microscope (AFM). The molecular organization of the solutions and crystal structure of the scaffolds were characterized by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD), respectively. The weight increase of the modified scaffolds and the pore size were determined. The morphology was observed by a scanning electron microscope (SEM). Mechanical properties were tested. Biofunctionalities were considered by seeding osteoblasts in silk fibroin scaffolds before analysis of the cell proliferation, viability, total protein assay, and histological analysis. The results demonstrated that dendrite structure of the fibrils occurred in those solutions. Molecular organization of the components in solution arranged themselves into an irregular structure. The fibrils were deposited in the pores of the modified silk fibroin scaffolds. The modified scaffolds showed a beta-sheet structure. The morphological structure affected the mechanical properties of the silk fibroin scaffolds with and without modification. Following assessment of the biofunctionalities, the modified silk fibroin scaffolds could induce cell proliferation, viability, and total protein particularly in modified silk fibroin with collagen/decellularized pulp. Furthermore, the histological analysis indicated that the cells could adhere in modified silk fibroin

  20. Enhanced bone formation in the vicinity of porous β-TCP scaffolds exhibiting slow release of collagen-derived tripeptides.

    Science.gov (United States)

    Kamikura, Keita; Minatoya, Tsutomu; Terada-Nakaishi, Michiko; Yamamoto, Shoko; Sakai, Yasuo; Furusawa, Toshitake; Matsushima, Yuta; Unuma, Hidero

    2017-09-01

    It has been experimentally proven that orally ingested collagen-derived tripeptides (Ctp) are quickly absorbed in the body and effectively promote the regeneration of connective tissues including bone and skin. Ctp are capable to activate osteoblasts and fibroblasts, which eventually promotes tissue regeneration. Based on these findings, a hypothesis was formulated in this study that direct delivery of Ctp to bone defect would also facilitate tissue regeneration as well as oral administration. To test the hypothesis, we prepared a bone augmentation material with the ability to slowly release Ctp, and investigated its in vivo bone regeneration efficacy. The implant material was porous β-tricalcium phosphate (β-TCP) scaffold which was coated with a co-precipitated layer of bone-like hydroxyapatite and Ctp. The β-TCP was impregnated with approximately 0.8%(w/w) Ctp. Then, the Ctp-modified β-TCP was implanted into bone defects of Wistar rats to evaluate in vivo efficacy of Ctp directly delivered from the material to the bone defects. The control was pristine porous β-TCP. In vitro tests showed that Ctp were steadily released from the co-precipitated layer for approximately two weeks. The Ctp-modified scaffolds significantly promoted new bone formation in vivo in their vicinity as compared with pristine β-TCP scaffolds; 6 weeks after the implantation, Ctp-modified scaffolds promoted twice as much bone formation as the control implants. Consequently, we achieved the slow and steady release of Ctp, and found that direct delivery of Ctp from implant materials was effective for bone regeneration as well as oral administration. A β-TCP scaffold capable of slowly releasing bone-enhancing substances significantly promoted bone formation.

  1. Effect of Concentration of Collagen Gel on Functional Activity of Bone Marrow Mesenchymal Stromal Cells.

    Science.gov (United States)

    Nashchekina, Yu A; Yudintceva, N M; Nikonov, P O; Ivanova, E A; Smagina, L V; Voronkina, I V

    2017-05-01

    Collagen I gels with protein concentrations of 1, 2, and 3.5 mg/ml were prepared and embedded in a porous polylactide scaffold to reduce their contraction. Concentration of the gel did not affect its degradation. Collagen gels promoted the formation of cell networks. The cells in the collagen gel with a concentration of 1 mg/ml embedded in polylactide scaffold had elongated spindle-like shape, in contrast to flattened cells in collagen gel of the same concentration not embedded in the scaffold. Stabilization of the collagen gel in the polylactide scaffold promoted active synthesis of laminin and fibronectin by cells as soon as on day 5 of culturing in comparison with that in free collagen substrate.

  2. New approaches and recent results concerning human-tissue collagen synthesis.

    Science.gov (United States)

    Smith, Ken; Rennie, Michael J

    2007-09-01

    Knowledge of the physiological regulation of human-tissue collagen metabolism in vivo is poor, due to the lack of appropriately robust methods. Recent application of stable isotope tracer techniques to measure human collagen synthesis has provided some insights into the role of nutrition and exercise on collagen turnover in the extracellular matrix of the musculoskeletal system. Collagen turnover in the musculoskeletal system is faster than previously thought. Bone collagen synthesis is increased by feeding, whereas both muscle collagen and tendon are unresponsive. Exercise stimulates collagen synthesis in both muscle and tendon in an apparently coordinated manner. There are also sex differences and normal aging is associated with increased muscle collagen synthesis and reductions in bone collagen synthesis, particularly in mature bone collagen. Collagen turnover appears to be faster than previously thought and is regulated by feeding and exercise, in a tissue-specific manner. Further application of these approaches, coupled with measures of gene and protein expression, to measure the acute regulation of collagen, will lead to a better understanding of the physiology and pathophysiology of human collagen turnover. This is particularly important for developing new therapies to improve bone health and minimize tissue fibrosis.

  3. Enhanced bone healing using collagen-hydroxyapatite scaffold implantation in the treatment of a large multiloculated mandibular aneurysmal bone cyst in a thoroughbred filly.

    Science.gov (United States)

    David, Florent; Levingstone, Tanya J; Schneeweiss, Wilfried; de Swarte, Marie; Jahns, Hanne; Gleeson, John P; O'Brien, Fergal J

    2015-10-01

    An unmet need remains for a bone graft substitute material that is biocompatible, biodegradable and capable of promoting osteogenesis safely in vivo. The aim of this study was to investigate the use of a novel collagen-hydroxyapatite (CHA) bone graft substitute in the clinical treatment of a mandibular bone cyst in a young horse and to assess its potential to enhance repair of the affected bone. A 2 year-old thoroughbred filly, presenting with a multilobulated aneurysmal bone cyst, was treated using the CHA scaffold. Post-operative clinical follow-up was carried out at 2 weeks and 3, 6 and 14 months. Cortical thickening in the affected area was observed from computed tomography (CT) examination as early as 3 months post-surgery. At 14 months, reduced enlargement of the operated mandible was observed, with no fluid-filled area. The expansile cavity was occupied by moderately dense mineralized tissue and fat and the compact bone was remodelled, with a clearer definition between cortex and medulla observed. This report demonstrates the promotion of enhanced bone repair following application of the CHA scaffold material in this craniomaxillofacial indication, and thus the potential of this material for translation to human applications. Copyright © 2015 John Wiley & Sons, Ltd.

  4. The Stable Isotopes of Carbon and Nitrogen in the Bones of Domestic Animals from three Cities of the European Part of Russia: First Results and Interpretations

    Directory of Open Access Journals (Sweden)

    Yavorskaya Liliya Vyacheslavovna

    2015-03-01

    Full Text Available The paper outlines the results of first purposeful research on isotopic composition (carbon 13С and nitrogen 15N in the bones collagen of domestic and wild animals from medieval towns at the European part of Russia. The published information about δ 13С и δ 15N was obtained from 61 samples of osteological collections of Yaroslavl, Rostov and Bolgar. The average values of carbon isotope in cattle bones are almost the same in all three cities. By contrast, these values for horses and pigs from Rostov and Bolgar are higher than for Yaroslavl animals. Unusual similarity for δ13С in the bones of sheep, camels and dogs among themselves from the Bolgar collection were fixed. The comparative analysis of the values δ13С in bones of domestic and wild animals allowed us to propose the hypothesis that sheep, camels and dogs appeared in Bolgar from the southern arid areas. The data on δ15N showed the inexplicably high accumulation of the nitrogen stable isotope in sheep and camel bones from the collection of Bolgar and in beaver bones from Rostov samples. This is probably due to the peculiarities of the diet of these dogs, enriched by the entrails of domestic ungulates or fish. The minimum values of δ15N in the bones of dogs from Bolgar reflect the specific diet of herding dogs with a minimal volume of meat. Simultaneously the data of 15N in sheep and camel bones from Bolgar collection and in beaver bones from Rostov samples howed the inexplicably high level of nitrogen stable isotope accumulation.

  5. Applicability of equine hydroxyapatite collagen (eHAC) bone blocks for lateral augmentation of the alveolar crest. A histological and histomorphometric analysis in rats

    NARCIS (Netherlands)

    Zecha, P. J.; Schortinghuis, J.; van der Wal, J. E.; Nagursky, H.; van den Broek, K. C.; Sauerbier, S.; Vissink, A.; Raghoebar, G. M.

    This study assessed the mechanical characteristics, biocompatibility and osteoconductive properties of an equine hydroxyapatite collagen (eHAC) bone block when applied as a bone substitute for lateral augmentation of rat mandible. 96 rats underwent lateral augmentation of the mandible, using two

  6. Extraction Socket Preservation Using Porcine-Derived Collagen Membrane Alone or Associated with Porcine-Derived Bone. Clinical Results of Randomized Controlled Study

    Directory of Open Access Journals (Sweden)

    Renzo Guarnieri

    2017-03-01

    Full Text Available Objectives: The aim of present randomized controlled clinical trial was to clinically evaluate hard tissue changes after extraction socket preservation procedures compared to natural spontaneous healing. Material and Methods: Thirty patients were enrolled in the present study and underwent single-tooth extraction in the premolar/molar areas. Ten sites were grafted with porcine-derived bone covered by collagen membrane, 10 covered by porcine-derived collagen membrane alone, and 10 underwent natural spontaneous healing. Vertical and horizontal bone changes after 3-month were evaluated at implant placement. Results: The vertical and horizontal bone changes at the extraction sockets treated with collagen membrane alone (vertical: -0.55 [SD 0.11] mm, and horizontal: -1.21 [SD 0.69] mm and collagen membrane plus porcine-derived bone (vertical: -0.37 [SD 0.7] mm, and horizontal: -0.91 [SD 0.53] mm were found significantly lower (P < 0.001, when compared to non-grafted sockets (vertical: -2.09 [SD 0.19] mm, and horizontal: -3.96 [SD 0.87] mm. In type 1 extraction sockets, in premolar sites, and in presence of vestibular bone thicknesses ≥ 1.5 mm, the use of collagen membrane alone revealed similar outcomes to those with additional graft material. Conclusions: At the re-entry surgery, extraction sockets grafted with porcine-derived bone and covered by collagen membrane, and extraction sockets covered by porcine-derived collagen membrane alone, showed significantly lower vertical and horizontal bone changes, compared to extraction sockets sites underwent natural spontaneous healing. However, a complete prevention of remodelling is not achievable, irrespective of the technique used.

  7. Proliferation and mineralization of bone marrow cells cultured on macroporous hydroxyapatite scaffolds functionalized with collagen type I for bone tissue regeneration.

    Science.gov (United States)

    Teixeira, S; Fernandes, M H; Ferraz, M P; Monteiro, F J

    2010-10-01

    This study concerns the preparation and in vitro characterization of functionalized hydroxyapatite (HA) porous scaffolds, which are intended to be used as drug-delivery systems and bone-regeneration matrices. Hydroxyapatite scaffolds were prepared using the polymer replication method, and, after being submitted to a specific sintering cycle, collagen Type I was incorporated on the surface. After the coating procedure, collagen was crosslinked using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) conjugation method. In this study, hydroxyapatite scaffolds with uncrosslinked and crosslinked Type I collagen were evaluated. Cell morphology and deposition of extracellular matrix were assessed by scanning electron microscopy, whereas cell distribution was visualized by means of methylene blue staining. MTS and total DNA quantification assays were used to evaluate the viability and proliferation of human bone marrow cells cultured on all the materials for 28 days. Results showed that the cells were able to adhere, proliferate, and form a mineralized matrix on the surface of all the materials. Furthermore, the cells were able to spread from one pore to another and form cell clusters. The results show that these scaffolds are good candidates to serve as drug delivery vehicles and for tissue engineering purposes. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

  8. Human Bone Derived Collagen for the Development of an Artificial Corneal Endothelial Graft. In Vivo Results in a Rabbit Model.

    Directory of Open Access Journals (Sweden)

    Natalia Vázquez

    Full Text Available Corneal keratoplasty (penetrating or lamellar using cadaveric human tissue, is nowadays the main treatment for corneal endotelial dysfunctions. However, there is a worldwide shortage of donor corneas available for transplantation and about 53% of the world's population have no access to corneal transplantation. Generating a complete cornea by tissue engineering is still a tough goal, but an endothelial lamellar graft might be an easier task. In this study, we developed a tissue engineered corneal endothelium by culturing human corneal endothelial cells on a human purified type I collagen membrane. Human corneal endothelial cells were cultured from corneal rims after corneal penetrating keratoplasty and type I collagen was isolated from remnant cancellous bone chips. Isolated type I collagen was analyzed by western blot, liquid chromatography -mass spectrometry and quantified using the exponentially modified protein abundance index. Later on, collagen solution was casted at room temperature obtaining an optically transparent and mechanically manageable membrane that supports the growth of human and rabbit corneal endothelial cells which expressed characteristic markers of corneal endothelium: zonula ocluddens-1 and Na+/K+ ATPase. To evaluate the therapeutic efficiency of our artificial endothelial grafts, human purified type I collagen membranes cultured with rabbit corneal endothelial cells were transplanted in New Zealand white rabbits that were kept under a minimal immunosuppression regimen. Transplanted corneas maintained transparency for as long as 6 weeks without obvious edema or immune rejection and maintaining the same endothelial markers that in a healthy cornea. In conclusion, it is possible to develop an artificial human corneal endothelial graft using remnant tissues that are not employed in transplant procedures. This artificial endothelial graft can restore the integrality of corneal endothelium in an experimental model of

  9. Induction of bone loss in DBA/1J mice immunized with citrullinated autologous mouse type II collagen in the absence of adjuvant.

    Science.gov (United States)

    Dusad, Anand; Duryee, Michael J; Shaw, Anita T; Klassen, Lynell W; Anderson, Daniel R; Wang, Dong; Ren, Ke; Gravallese, Ellen M; O'Dell, James R; Mikuls, Ted R; Thiele, Geoffrey M

    2014-01-01

    Joint damage in rheumatoid arthritis (RA) is characterized by cartilage and bone loss resulting in pain, deformity, and loss of joint function. Anti-citrullinated protein antibody (ACPA) has been implicated in RA pathogenesis and predicts radiographical joint damage and clinical severity. Therefore, the purpose of this study was to assess bone loss by micro-CT, histological joint damage, and ACPA levels using a mouse model of RA. Arthritis was induced by immunizing DBA/1 mice with autologous citrullinated type II mouse collagen (CIT-CII) weekly for 4 weeks. Mice immunized with autologous CII served as controls. At week 5, mice were killed, ACPA levels determined, and micro-CT performed to quantitatively analyze bone damage. Micro-CT analysis revealed significant loss of bone density, volume, and surface (p bone peripheral to the inflamed joints of CIT-CII animals compared to CII controls. Histological staining demonstrated cartilage, proteoglycan, joint collagen, and bone collagen loss in the CIT-CII group compared to CII. Serum ACPA levels were increased (p = 0.03) in the CIT-CII group compared to CII, and these levels were inversely correlated with bone quantity and quality. In this study, we demonstrate that immunization with autologous CIT-CII initiates significant systemic bone and articular cartilage loss in the absence of adjuvant. Significant inverse correlations of circulating ACPA and bone quality/quantity were present. ACPA levels predict the adverse bone morphological changes in this model of early RA.

  10. Preparation of a biomimetic composite scaffold from gelatin/collagen and bioactive glass fibers for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Sharifi, Esmaeel; Azami, Mahmoud [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Kajbafzadeh, Abdol-Mohammad [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Pediatric Urology, Children' s Hospital Medical Center, Tehran, Iran (IRI) (Iran, Islamic Republic of); Moztarzadeh, Fatollah [Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Faridi-Majidi, Reza [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shamousi, Atefeh; Karimi, Roya [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ai, Jafar, E-mail: jafar_ai@tums.ac.ir [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Brain and Spinal Injury Research Center (BASIR), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-02-01

    Bone tissue is a composite material made of organic and inorganic components. Bone tissue engineering requires scaffolds that mimic bone nature in chemical and mechanical properties. This study proposes a novel method for preparing composite scaffolds that uses sub-micron bioglass fibers as the organic phase and gelatin/collagen as the inorganic phase. The scaffolds were constructed by using freeze drying and electro spinning methods and their mechanical properties were enhanced by using genipin crosslinking agent. Electron microscopy micrographs showed that the structure of composite scaffolds were porous with pore diameters of approximately 70–200 μm, this was again confirmed by mercury porosimetery. These pores are suitable for osteoblast growth. The diameters of the fibers were approximately 150–450 nm. Structural analysis confirmed the formation of desirable phases of sub-micron bioglass fibers. Cellular biocompatibility tests illustrated that scaffolds containing copper ion in the bioglass structure had more cell growth and osteoblast attachment in comparison to copper-free scaffolds. - Highlights: • Fabrication of 45S5 sub-micron bioglass fiber using electrospinning method. • Production of copper doped submicron bioglass fibers on 45S5 bioglass base by electrospinning sol gel route method. • Incorporation of bioglass/Cu-bioglass sub-micron fibers into gelatin/collagen matrix to form biomimetic composite scaffold which were non-cytotoxic according to MTT assay. • Discovering that copper can decrease the glass transition temperatures and enhance osteoblast cell adhesion and viability.

  11. Differentiation of Murine Bone Marrow-Derived Smooth Muscle Progenitor Cells Is Regulated by PDGF-BB and Collagen.

    Directory of Open Access Journals (Sweden)

    Clifford Lin

    Full Text Available Smooth muscle cells (SMCs are key regulators of vascular disease and circulating smooth muscle progenitor cells may play important roles in vascular repair or remodelling. We developed enhanced protocols to derive smooth muscle progenitors from murine bone marrow and tested whether factors that are increased in atherosclerotic plaques, namely platelet-derived growth factor-BB (PDGF-BB and monomeric collagen, can influence the smooth muscle specific differentiation, proliferation, and survival of mouse bone marrow-derived progenitor cells. During a 21 day period of culture, bone marrow cells underwent a marked increase in expression of the SMC markers α-SMA (1.93 ± 0.15 vs. 0.0008 ± 0.0003 (ng/ng GAPDH at 0 d, SM22-α (1.50 ± 0.27 vs. 0.005 ± 0.001 (ng/ng GAPDH at 0 d and SM-MHC (0.017 ± 0.004 vs. 0.001 ± 0.001 (ng/ng GAPDH at 0 d. Bromodeoxyuridine (BrdU incorporation experiments showed that in early culture, the smooth muscle progenitor subpopulation could be identified by high proliferative rates prior to the expression of smooth muscle specific markers. Culture of fresh bone marrow or smooth muscle progenitor cells with PDGF-BB suppressed the expression of α-SMA and SM22-α, in a rapidly reversible manner requiring PDGF receptor kinase activity. Progenitors cultured on polymerized collagen gels demonstrated expression of SMC markers, rates of proliferation and apoptosis similar to that of cells on tissue culture plastic; in contrast, cells grown on monomeric collagen gels displayed lower SMC marker expression, lower growth rates (319 ± 36 vs. 635 ± 97 cells/mm2, and increased apoptosis (5.3 ± 1.6% vs. 1.0 ± 0.5% (Annexin 5 staining. Our data shows that the differentiation and survival of smooth muscle progenitors are critically affected by PDGF-BB and as well as the substrate collagen structure.

  12. Reconstruction of alveolar bone defects using bone morphogenetic protein 2 mediated rabbit dental pulp stem cells seeded on nano-hydroxyapatite/collagen/poly(L-lactide).

    Science.gov (United States)

    Liu, Hong-Chen; E, Ling-Ling; Wang, Dong-Sheng; Su, Fang; Wu, Xia; Shi, Zhan-Ping; Lv, Yan; Wang, Jia-Zhu

    2011-10-01

    The objective of the present study was to evaluate the capacity of a tissue-engineered bone complex of recombinant human bone morphogenetic protein 2 (rhBMP-2)-mediated dental pulp stem cells (DPSCs) and nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA) to reconstruct critical-size alveolar bone defects in New Zealand rabbit. Autologous DPSCs were isolated from rabbit dental pulp tissue and expanded ex vivo to enrich DPSCs numbers, and then their attachment and differentiation capability were evaluated when cultured on the culture plate or nHAC/PLA. The alveolar bone defects were treated with nHAC/PLA, nHAC/PLA+rhBMP-2, nHAC/PLA+DPSCs, nHAC/PLA+DPSCs+rhBMP-2, and autogenous bone (AB) obtained from iliac bone or were left untreated as a control. X-ray and a polychrome sequential fluorescent labeling were performed postoperatively and the animals were sacrificed 12 weeks after operation for histological observation and histomorphometric analysis. Our results showed that DPSCs expressed STRO-1 and vementin, and favored osteogenesis and adipogenesis in conditioned media. DPSCs attached and spread well, and retained their osteogenic phenotypes on nHAC/PLA. The rhBMP-2 could significantly increase protein content, alkaline phosphatase activity/protein, osteocalcin content, and mineral formation of DPSCs cultured on nHAC/PLA. The X-ray graph, the fluorescent, histological observation, and histomorphometric analysis showed that the nHAC/PLA+DPSCs+rhBMP-2 tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than nHAC/PLA, nHAC/PLA+rhBMP-2, and nHAC/PLA+DPSCs, or even autologous bone. Implanted DPSCs' contribution to new bone was detected through transfected eGFP genes. Our findings indicated that stem cells existed in adult rabbit dental pulp tissue. The rhBMP-2 promoted osteogenic capability of DPSCs as a potential cell source for periodontal bone regeneration. The nHAC/PLA could serve as a good scaffold for

  13. Raman spectral markers of collagen denaturation and hydration in human cortical bone tissue are affected by radiation sterilization and high cycle fatigue damage.

    Science.gov (United States)

    Flanagan, Christopher D; Unal, Mustafa; Akkus, Ozan; Rimnac, Clare M

    2017-11-01

    Thermal denaturation and monotonic mechanical damage alter the organic and water-related compartments of cortical bone. These changes can be detected using Raman spectroscopy. However, less is known regarding Raman sensitivity to detect the effects of cyclic fatigue damage and allograft sterilization doses of gamma radiation. To determine if Raman spectroscopic biomarkers of collagen denaturation and hydration are sensitive to the effects of (a) high cycle fatigue damage and (b) 25kGy irradiation. Unirradiated and gamma-radiation sterilized human cortical bone specimens previously tested in vitro under high-cycle (> 100,000 cycles) fatigue conditions at 15MPa, 25MPa, 35MPa, 45MPa, and 55MPa cyclic stress levels were studied. Cortical bone Raman spectral profiles from wavenumber ranges of 800-1750cm -1 and 2700-3800cm -1 were obtained and compared from: a) non-fatigue vs fatigue fracture sites and b) radiated vs. unirradiated states. Raman biomarker ratios 1670/1640 and 3220/2949, which reflect collagen denaturation and organic matrix (mainly collagen)-bound water, respectively, were assessed. One- and two-way ANOVA analyses were utilized to identify differences between groups along with interaction effects between cyclic fatigue and radiation-induced damage. Cyclic fatigue damage resulted in increases in collagen denaturation (1670/1640: 1.517 ± 0.043 vs 1.579 ± 0.021, p collagen denaturation (r = 0.514, p collagen)-bound water. A Raman measure of collagen denaturation was sensitive to cyclic fatigue damage but not 25kGy irradiation. Collagen denaturation was correlated with organic matrix-bound water, suggesting that denaturation of collagen to gelatinous form may expose more binding sites to water by unwinding the triple alpha chains. This research may eventually be useful to help identify allograft quality and more appropriately match donors to recipients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Evaluation of rhBMP-2/collagen/TCP-HA bone graft with and without bone marrow cells in the canine femoral multi defect model.

    Science.gov (United States)

    Luangphakdy, V; Shinohara, K; Pan, H; Boehm, C; Samaranska, A; Muschler, G F

    2015-01-12

    Recombinant human bone morphogenetic protein-2, when applied to an absorbable type 1 bovine collagen sponge (rhBMP-2/ACS) is an effective therapy in many bone grafting settings. Bone marrow aspirate (BMA) has also been used as a source of transplantable osteogenic connective tissue progenitors. This study was designed to characterize the performance of a scaffold comprising rhBMP-2/ACS in which the sponge wraps around tri-calcium phosphate hydroxyapatite granules (rhBMP-2/ACS/TCP-HA) and to test the hypothesis that addition of BMA will improve the performance of this construct in the Canine Femoral Multi Defect Model. In each subject, two sites were grafted with rhBMP-2/ACS/TCP-HA scaffold loaded with BMA clot and two other sites with rhBMP-2/ACS/TCP-HA scaffold loaded with wound blood (WB). After correction for unresorbed TCP-HA granules, sites grafted with rhBMP-2/ACS/TCP-HA+BMA and rhBMP-2/ACS/TCP-HA+WB were similar, with mean percent bone volumes of 10.9 %±1.2 and 11.2 %±1.2, respectively. No differences were seen in quantitative histomorphometry. While bone formation using both constructs was robust, this study did not support the hypothesis that the addition of unprocessed bone marrow aspirate clot improved bone regeneration in a site engrafted with rhBMP-2/ACS/TCP-HA+BMA. In contrast to prior studies using this model, new bone formation was greater at the center of the defect where TCP-HA was distributed. This finding suggests a potential synergy between rhBMP-2 and the centrally placed ceramic and cellular components of the graft construct. Further optimization may also require more uniform distribution of TCP-HA, alternative cell delivery strategies, and a more rigorous large animal segmental defect model.

  15. Evaluation of 3D printed PCL/PLGA/β-TCP versus collagen membranes for guided bone regeneration in a beagle implant model.

    Science.gov (United States)

    Won, J-Y; Park, C-Y; Bae, J-H; Ahn, G; Kim, C; Lim, D-H; Cho, D-W; Yun, W-S; Shim, J-H; Huh, J-B

    2016-10-07

    Here, we compared 3D-printed polycaprolactone/poly(lactic-co-glycolic acid)/β-tricalcium phosphate (PCL/PLGA/β-TCP) membranes with the widely used collagen membranes for guided bone regeneration (GBR) in beagle implant models. For mechanical property comparison in dry and wet conditions and cytocompatibility determination, we analyzed the rate and pattern of cell proliferation of seeded fibroblasts and preosteoblasts using the cell counting kit-8 assay and scanning electron microscopy. Osteogenic differentiation was verified using alizarin red S staining. At 8 weeks following implantation in vivo using beagle dogs, computed tomography and histological analyses were performed after sacrifice. Cell proliferation rates in vitro indicated that early cell attachment was higher in collagen than in PCL/PLGA/β-TCP membranes; however, the difference subsided by day 7. Similar outcomes were found for osteogenic differentiation, with approximately 2.5 times greater staining in collagen than PCL/PLGA/β-TCP, but without significant difference by day 14. In vivo, bone regeneration in the defect area, represented by new bone formation and bone-to-implant contact, paralleled those associated with collagen membranes. However, tensile testing revealed that whereas the PCL/PLGA/β-TCP membrane mechanical properties were conserved in both wet and dry states, the tensile property of collagen was reduced by 99% under wet conditions. Our results demonstrate in vitro and in vivo that PCL/PLGA/β-TCP membranes have similar levels of biocompatibility and bone regeneration as collagen membranes. In particular, considering that GBR is always applied to a wet environment (e.g. blood, saliva), we demonstrated that PCL/PLGA/β-TCP membranes maintained their form more reliably than collagen membranes in a wet setting, confirming their appropriateness as a GBR membrane.

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

    Directory of Open Access Journals (Sweden)

    WY Lai

    2013-10-01

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

  17. Prospective Clinical and Radiographic Study of Alveolar Ridge Preservation Combining Freeze-Dried Bone Allograft With Two Xenogeneic Collagen Matrices.

    Science.gov (United States)

    Parashis, Andreas O; Hawley, Charles E; Stark, Paul C; Ganguly, Rumpa; Hanley, James B; Steffensen, Bjorn

    2016-04-01

    Tooth extractions are followed by significant dimensional changes in the alveolar crest that may preclude implant placement. This randomized, controlled, prospective compares the preservation of soft and hard tissue dimensional changes after alveolar ridge preservation (ARP) using two membranes consisting of collagen matrix (CM) or extracellular matrix (ECM) as barriers over freeze-dried bone allograft (FDBA). Standardized clinical and radiographic measurements of soft and hard tissues were recorded by means of a stent before and 4 months after ARP. The surgery entailed sulcular incisions with minimal flap elevation and repositioning without advancement. Of 11 patients in the CM group and 12 in the ECM group who completed the study, gingival thickness (GT) increased from 0.1 to 0.2 mm for both groups along with a 0.5-mm decrease in the width of keratinized tissue after healing. Reductions in ridge width were most pronounced on the coronal aspect, 1.8 mm for CM and 2.0 mm for ECM, whereas vertical reduction was most pronounced on the buccal aspect, 0.7 to 1.0 mm. Differences between groups were not statistically significant. However, significant correlation for changes in GT (P = 0.001) and crestal bone width (P = 0.002) with preoperative buccal plate thickness (BPT) was observed. Both xenogeneic collagen matrices combined with FDBA were effective in maintaining soft tissues and minimizing ridge resorption in all dimensions after ARP. BPT was an important determinant for amount of change in crestal GT and ridge width.

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

    Directory of Open Access Journals (Sweden)

    Max M Villa

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

  19. Antioxidative Peptides Derived from Enzyme Hydrolysis of Bone Collagen after Microwave Assisted Acid Pre-Treatment and Nitrogen Protection

    Directory of Open Access Journals (Sweden)

    Jin Sun

    2010-11-01

    Full Text Available This study focused on the preparation method of antioxidant peptides by enzymatic hydrolysis of bone collagen after microwave assisted acid pre-treatment and nitrogen protection. Phosphoric acid showed the highest ability of hydrolysis among the four other acids tested (hydrochloric acid, sulfuric acid and/or citric acid. The highest degree of hydrolysis (DH was 9.5% using 4 mol/L phosphoric acid with a ratio of 1:6 under a microwave intensity of 510 W for 240 s. Neutral proteinase gave higher DH among the four protease tested (Acid protease, neutral protease, Alcalase and papain, with an optimum condition of: (1 ratio of enzyme and substrate, 4760 U/g; (2 concentration of substrate, 4%; (3 reaction temperature, 55 °C and (4 pH 7.0. At 4 h, DH increased significantly (P < 0.01 under nitrogen protection compared with normal microwave assisted acid pre-treatment hydrolysis conditions. The antioxidant ability of the hydrolysate increased and reached its maximum value at 3 h; however DH decreased dramatically after 3 h. Microwave assisted acid pre-treatment and nitrogen protection could be a quick preparatory method for hydrolyzing bone collagen.

  20. The effect of fresh bone marrow cells on reconstruction of mouse calvarial defect combined with calvarial osteoprogenitor cells and collagen-apatite scaffold.

    Science.gov (United States)

    Yu, Xiaohua; Wang, Liping; Peng, Fei; Jiang, Xi; Xia, Zengmin; Huang, Jianping; Rowe, David; Wei, Mei

    2013-12-01

    Fresh bone marrow cells have already exhibited its advantages as osteogenic donor cells, but the combination between fresh bone marrow cells and other donor cells utilized for bone healing has not been fully explored. To highlight the impact of fresh bone marrow cells on scaffold-based bone regeneration, single or a combination of calvarial osteoprogenitor cells (OPCs) and bone marrow cells (BMCs) were used as donor cells combined with collagen-apatite scaffold for calvarial defect healing. The host and donor contributions to bone formation were assessed using histological and GFP imaging analysis. Although the amount of new bone formed by different cell sources did not show significant differences, the origin of the bone formation in the defects mainly depended on the types of donor cells employed: when only calvarial OPCs were used as donor cells, a donor-derived bone healing instead of host-derived bone ingrowth was observed; when only fresh BMCs were loaded, the host bone could grow into the defect along the lamellar structure of the scaffolds, but the amount of new bone formed was significantly lower than the defect loaded with calvarial OPCs only. The combination of calvarial OPCs and fresh BMCs had similar amount of new bone formation as the group loaded with calvarial osteoprogenitors alone, but did not induce any host-derived bone formation. These results provide compelling evidence of the importance of fresh BMCs to induce host-implant integration in bone tissue engineering. Copyright © 2012 John Wiley & Sons, Ltd.

  1. Determination of osteogenic or adipogenic lineages in muscle-derived stem cells (MDSCs) by a collagen-binding peptide (CBP) derived from bone sialoprotein (BSP)

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yoon Jung [Dental Regenerative Biotechnology Major, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Lee, Jue Yeon [Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Lee, Seung Jin [Department of Industrial Pharmacy, College of Pharmacy, Ewha Womans University, Seoul (Korea, Republic of); Chung, Chong-Pyoung, E-mail: ccpperio@snu.ac.kr [Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Department of Periodontology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Park, Yoon Jeong, E-mail: parkyj@snu.ac.kr [Dental Regenerative Biotechnology Major, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer CBP sequence is identified from BSP and has collagen binding activity. Black-Right-Pointing-Pointer CBP directly activates the MAPK signaling, especially ERK1/2. Black-Right-Pointing-Pointer CBP increase osteoblastic differentiation by the activation of Runx2. Black-Right-Pointing-Pointer CBP decrease adipogenic differentiation by the inhibition of PPAR{gamma}. -- Abstract: Bone sialoprotein (BSP) is a mineralized, tissue-specific, non-collagenous protein that is normally expressed only in mineralized tissues such as bone, dentin, cementum, and calcified cartilage, and at sites of new mineral formation. The binding of BSP to collagen is thought to be important for initiating bone mineralization and bone cell adhesion to the mineralized matrix. Several recent studies have isolated stem cells from muscle tissue, but their functional properties are still unclear. In this study, we examined the effects of a synthetic collagen-binding peptide (CBP) on the differentiation efficiency of muscle-derived stem cells (MDSCs). The CBP sequence (NGVFKYRPRYYLYKHAYFYPHLKRFPVQ) corresponds to residues 35-62 of bone sialoprotein (BSP), which are located within the collagen-binding domain in BSP. Interestingly, this synthetic CBP inhibited adipogenic differentiation but increased osteogenic differentiation in MDSCs. The CBP also induced expression of osteoblastic marker proteins, including alkaline phosphatase (ALP), type I collagen, Runt-related transcription factor 2 (Runx2), and osteocalcin; prevented adipogenic differentiation in MDSCs; and down-regulated adipose-specific mRNAs, such as adipocyte protein 2 (aP2) and peroxisome proliferator-activated receptor {gamma}. The CBP increased Extracellular signal-regulated kinases (ERK) 1/2 protein phosphorylation, which is important in lineage determination. These observations suggest that this CBP determines the osteogenic or adipogenic lineage in MDSCs by activating ERK1/2. Taken together, a

  2. Effects of Ulmus davidiana planch on mineralization, bone morphogenetic protein-2, alkaline phosphatase, type I collagen, and collagenase-1 in bone cells.

    Science.gov (United States)

    Kang, Sung-Koo; Kim, Kap-Sung; Byun, Yu-Seok; Suh, Seok-Jong; Jim, Un-Ho; Kim, Kyung-Ho; Lee, In-Seon; Kim, Cheorl-Ho

    2006-01-01

    Ulmus davidiana Planch (Ulmaceae) (UD) long has been known to have anti-inflammatory and protective effects on damaged tissue, inflammation, and bone among other functions. The herbal medicine also is being used in Oriental medicine to treat osteoporosis. In a preliminary study, treatment of osteoclasts containing long bone cells with the water extract of UD bark prevented the intracellular maturation of cathepsin K (cat K), and thus, it was considered that UD is a pro-drug of a potent bone-resorption inhibitor. To further clarify the role of UD in ossification, we investigated the effects of UD on the proliferation and differentiation of osteoblastic cell lines in vitro. In this study, we assessed the effects of UD on osteoblastic differentiation in nontransformed osteoblastic cells (MC3T3-E1) and rat bone marrow cells. UD enhanced alkaline phosphatase (ALP) activity and mineralization in a dose- and time-dependent fashion. This stimulatory effect of the UD was observed at relatively low doses (significant at 5-50 microg/ml and maximal at 50 microg/ml). Northern blot analysis showed that UD (100 microg/ml) increases in bone morphogenic protein-2 as well as ALP mRNA concentrations in MC3T3-E1 cells. UD slightly increased in type I collagen mRNA abundance throughout the culture period, whereas it markedly inhibited the gene expression of collagenase-1 between days 15 and 20 of culture. These results indicate that UD has anabolic effects on bone through the promotion of osteoblastic differentiation, suggesting that it could be used for the treatment of common metabolic bone diseases such as osteoporosis.

  3. Biomimetic fabrication of a three-level hierarchical calcium phosphate/collagen/hydroxyapatite scaffold for bone tissue engineering

    International Nuclear Information System (INIS)

    Zhou, Changchun; Ye, Xingjiang; Fan, Yujiang; Tan, Yanfei; Qing, Fangzu; Zhang, Xingdong; Ma, Liang

    2014-01-01

    A three-level hierarchical calcium phosphate/collagen/hydroxyapatite (CaP/Col/HAp) scaffold for bone tissue engineering was developed using biomimetic synthesis. Porous CaP ceramics were first prepared as substrate materials to mimic the porous bone structure. A second-level Col network was then composited into porous CaP ceramics by vacuum infusion. Finally, a third-level HAp layer was achieved by biomimetic mineralization. The three-level hierarchical biomimetic scaffold was characterized using scanning electron microscopy, energy-dispersive x-ray spectra, x-ray diffraction and Fourier transform infrared spectroscopy, and the mechanical properties of the scaffold were evaluated using dynamic mechanical analysis. The results show that this scaffold exhibits a similar structure and composition to natural bone tissues. Furthermore, this three-level hierarchical biomimetic scaffold showed enhanced mechanical strength compared with pure porous CaP scaffolds. The biocompatibility and osteoinductivity of the biomimetic scaffolds were evaluated using in vitro and in vivo tests. Cell culture results indicated the good biocompatibility of this biomimetic scaffold. Faster and increased bone formation was observed in these scaffolds following a six-month implantation in the dorsal muscles of rabbits, indicating that this biomimetic scaffold exhibits better osteoinductivity than common CaP scaffolds. (papers)

  4. Hybrid Membranes of PLLA/Collagen for Bone Tissue Engineering: A Comparative Study of Scaffold Production Techniques for Optimal Mechanical Properties and Osteoinduction Ability

    Directory of Open Access Journals (Sweden)

    Flávia Gonçalves

    2015-01-01

    Full Text Available Synthetic and natural polymer association is a promising tool in tissue engineering. The aim of this study was to compare five methodologies for producing hybrid scaffolds for cell culture using poly-l-lactide (PLLA and collagen: functionalization of PLLA electrospun by (1 dialkylamine and collagen immobilization with glutaraldehyde and by (2 hydrolysis and collagen immobilization with carbodiimide chemistry; (3 co-electrospinning of PLLA/chloroform and collagen/hexafluoropropanol (HFP solutions; (4 co-electrospinning of PLLA/chloroform and collagen/acetic acid solutions and (5 electrospinning of a co-solution of PLLA and collagen using HFP. These materials were evaluated based on their morphology, mechanical properties, ability to induce cell proliferation and alkaline phosphatase activity upon submission of mesenchymal stem cells to basal or osteoblastic differentiation medium (ODM. Methods (1 and (2 resulted in a decrease in mechanical properties, whereas methods (3, (4 and (5 resulted in materials of higher tensile strength and osteogenic differentiation. Materials yielded by methods (2, (3 and (5 promoted osteoinduction even in the absence of ODM. The results indicate that the scaffold based on the PLLA/collagen blend exhibited optimal mechanical properties and the highest capacity for osteodifferentiation and was the best choice for collagen incorporation into PLLA in bone repair applications.

  5. Evaluation of osteocalcin and pyridinium crosslinks of bone collagen as markers of bone turnover in gingival crevicular fluid during different stages of orthodontic treatment.

    Science.gov (United States)

    Griffiths, G S; Moulson, A M; Petrie, A; James, I T

    1998-06-01

    Osteocalcin (Oc) and the collagen cross-links pyridinoline (Pyr) and deoxypyridinoline (dPyr) are used as markers of bone turnover in metabolic bone diseases. The aims of this study were: 1) to establish if Oc, Pyr and dPyr can be detected in GCF and 2) using the orthodontic tooth movement model of alveolar bone resorption to evaluate GCF levels of osteocalcin and these collagen cross-links as markers of bone breakdown. Plaque, colour and bleeding indices, probing measurements and GCF samples were collected at two sites in each of 20 adolescents, during 4 stages of fixed appliance therapy: (1) prior to appliance fit, (2) post appliance fit, (3) during active retraction of the maxillary canines, (4) during retention. GCF was collected onto filter paper strips and the volume determined by weighing. An ELISA kit was used for the detection of osteocalcin, whereas Pyr and dPyr were assayed using high performance liquid chromotography (HPLC). Wilcoxon signed ranks test and Bonferroni correction revealed statistically significant increases in plaque (p= 0.012), GCF volume (p=0.024) and osteocalcin concentration (p=0.012), between stages 1 and 2. There were no statistically significant differences between the other variables at this stage or between any of the variables at stages 2 and 3, or between stages 3 and 4. All but 3 of the GCF samples yielded detectable osteocalcin, with large site and subject variation. The median values of osteocalcin and osteocalcin concentration of all the samples were 87.5 pg and 66 pg/microl, with a range of 0-1,248 pg, 0-1,572 pg/microl. The detection of osteocalcin in GCF during every stage, the wide variation between subjects, and the lack of a consistent pattern related to stages of orthodontic treatment, suggests that osteocalcin may merely be a constituent of GCF associated with the developing dentition, which would reduce its potential as a marker of bone turnover in this group. None of the 16 GCF samples analysed for Pyr and d

  6. Prdm5 Regulates Collagen Gene Transcription by Association with RNA Polymerase II in Developing Bone

    DEFF Research Database (Denmark)

    Galli, Giorgio Giacomo; Honnens de Lichtenberg, Kristian; Carrara, Matteo

    2012-01-01

    and fibrillogenesis by binding inside the Col1a1 gene body and maintaining RNA polymerase II occupancy. In vivo, Prdm5 loss results in delayed ossification involving a pronounced impairment in the assembly of fibrillar collagens. Collectively, our results define a novel role for Prdm5 in sustaining...

  7. Micro/Nano Multilayered Scaffolds of PLGA and Collagen by Alternately Electrospinning for Bone Tissue Engineering

    Science.gov (United States)

    Kwak, Sanghwa; Haider, Adnan; Gupta, Kailash Chandra; Kim, Sukyoung; Kang, Inn-Kyu

    2016-07-01

    The dual extrusion electrospinning technique was used to fabricate multilayered 3D scaffolds by stacking microfibrous meshes of poly(lactic acid-co-glycolic acid) (PLGA) in alternate fashion to micro/nano mixed fibrous meshes of PLGA and collagen. To fabricate the multilayered scaffold, 35 wt% solution of PLGA in THF-DMF binary solvent (3:1) and 5 wt% solution of collagen in hexafluoroisopropanol (HFIP) with and without hydroxyapatite nanorods (nHA) were used. The dual and individual electrospinning of PLGA and collagen were carried out at flow rates of 1.0 and 0.5 mL/h, respectively, at an applied voltage of 20 kV. The density of collagen fibers in multilayered scaffolds has controlled the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. The homogeneous dispersion of glutamic acid-modified hydroxyapatite nanorods (nHA-GA) in collagen solution has improved the osteogenic properties of fabricated multilayered scaffolds. The fabricated multilayered scaffolds were characterized using FT-IR, X-ray photoelectron spectroscopy, and transmission electron microscopy (TEM). The scanning electron microscopy (FE-SEM) was used to evaluate the adhesion and spreads of MC3T3-E1 cells on multilayered scaffolds. The activity of MC3T3-E1 cells on the multilayered scaffolds was evaluated by applying MTT, alkaline phosphatase, Alizarin Red, von Kossa, and cytoskeleton F-actin assaying protocols. The micro/nano fibrous PLGA-Col-HA scaffolds were found to be highly bioactive in comparison to pristine microfibrous PLGA and micro/nano mixed fibrous PLGA and Col scaffolds.

  8. A preliminary carbon and nitrogen isotopic investigation of bone collagen from skeletal remains recovered from a Pre-Columbian burial site, Matanzas Province, Cuba

    International Nuclear Information System (INIS)

    Buhay, W.M.; Chinique de Armas, Y.; Rodriguez Suárez, R.; Arredondo, C.; Smith, D.G.; Armstrong, S.D.; Roksandic, M.

    2013-01-01

    Highlights: ► Collagen isotope (carbon and nitrogen) based reconstruction of paleodiets. ► Human remains recovered from Canimar Abajo, Matanzas Province, Cuba. ► Individuals consumed marine resource diets supplemented with terrestrial plants. ► Trophic level and isotope shifts for breastfed and weaned infant/juveniles (I/J). ► I/J evidence of weaning through distinct δ 15 N enrichments and δ 13 C depletions. - Abstract: This preliminary study investigates the diet of a population of humans (n = 28) recovered from a shell-matrix site of Canimar Abajo on the Canimar River, Matanzas Province, Cuba. The site is characterized by two cemetery levels separated by a layer of occupation/ritual/midden activity that lasted 1.5 ka. Stable C (δ 13 C) and N (δ 15 N) isotope analysis of human bone collagen samples obtained from individuals (7 infant/juveniles, and 21 adults) from both cemetery levels was conducted in order to reconstruct the diet of these two populations, investigate the relative importance of marine vs. terrestrial resources, and reveal any sex- and age-related distinctions in their food sources. Initial indications suggest that individuals from both cemetery levels consumed diets that were marine resource intensive but also supplemented with varied additions of terrestrial (mostly plant) resources. This supplementation is particularly evident in the later cemetery population. Though there are no significant differences in diet according to sex, there is a trophic level and terrestrial-based shift for breastfed and weaning infant/juveniles. The infant/juveniles showed evidence of being weaned through distinct δ 15 N enrichments and δ 13 C depletions over adult females

  9. Osteoinduction and proliferation of bone-marrow stromal cells in three-dimensional poly (ε-caprolactone)/ hydroxyapatite/collagen scaffolds.

    Science.gov (United States)

    Wang, Ting; Yang, Xiaoyan; Qi, Xin; Jiang, Chaoyin

    2015-05-08

    Osteoinduction and proliferation of bone-marrow stromal cells (BMSCs) in three-dimensional (3D) poly(ε-caprolactone) (PCL) scaffolds have not been studied throughly and are technically challenging. This study aimed to optimize nanocomposites of 3D PCL scaffolds to provide superior adhesion, proliferation and differentiation environment for BMSCs in this scenario. BMSCs were isolated and cultured in a novel 3D tissue culture poly(ε-caprolactone) (PCL) scaffold coated with poly-lysine, hydroxyapatite (HAp), collagen and HAp/collagen. Cell morphology was observed and BMSC biomarkers for osteogenesis, osteoblast differentiation and activation were analyzed. Scanning Electron Microscope (SEM) micrographs showed that coating materials were uniformly deposited on the surface of PCL scaffolds and BMSCs grew and aggregated to form clusters during 3D culture. Both mRNA and protein levels of the key players of osteogenesis and osteoblast differentiation and activation, including runt-related transcription factor 2 (Runx2), alkaline phosphates (ALP), osterix, osteocalcin, and RANKL, were significantly higher in BMSCs seeded in PCL scaffolds coated with HAp or HAp/collagen than those seeded in uncoated PCL scaffolds, whereas the expression levels were not significantly different in collagen or poly-lysine coated PCL scaffolds. In addition, poly-lysine, collagen, HAp/collagen, and HAp coated PCL scaffolds had significantly more viable cells than uncoated PCL scaffolds, especially scaffolds with HAp/collagen and collagen-alone coatings. That BMSCs in HAp or HAp/collagen PCL scaffolds had remarkably higher ALP activities than those in collagen-coated alone or uncoated PCL scaffolds indicating higher osteogenic differentiation levels of BMSCs in HAp or HAp/collagen PCL scaffolds. Moreover, morphological changes of BMSCs after four-week of 3D culture confirmed that BMSCs successfully differentiated into osteoblast with spread-out phenotype in HAp/collagen coated PCL scaffolds

  10. Single-dose local administration of parathyroid hormone (1-34, PTH) with β-tricalcium phosphate/collagen (β-TCP/COL) enhances bone defect healing in ovariectomized rats.

    Science.gov (United States)

    Tao, Zhou-Shan; Zhou, Wan-Shu; Wu, Xin-Jing; Wang, Lin; Yang, Min; Xie, Jia-Bing; Xu, Zhu-Jun; Ding, Guo-Zheng

    2018-02-01

    Parathyroid hormone (1-34, PTH) combined β-tricalcium phosphate (β-TCP) achieves stable bone regeneration without cell transplantation in previous studies. Recently, with the development of tissue engineering slow release technology, PTH used locally to promote bone defect healing become possible. This study by virtue of collagen with a combination of drugs and has a slow release properties, and investigated bone regeneration by β-TCP/collagen (β-TCP/COL) with the single local administration of PTH. After the creation of a rodent critical-sized femoral metaphyseal bone defect, β-TCP/COL was prepared by mixing sieved granules of β-TCP and atelocollagen for medical use, then β-TCP/COL with dripped PTH solution (1.0 µg) was implanted into the defect of OVX rats until death at 4 and 8 weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, and biomechanics. The results of our study show that single-dose local administration of PTH combined local usage of β-TCP/COL can increase the healing of defects in OVX rats. Furthermore, treatments with single-dose local administration of PTH and β-TCP/COL showed a stronger effect on accelerating the local bone formation than β-TCP/COL used alone. The results from our study demonstrate that combination of single-dose local administration of PTH and β-TCP/COL had an additive effect on local bone formation in osteoporosis rats.

  11. In situ observation of fluoride-ion-induced hydroxyapatite-collagen detachment on bone fracture surfaces by atomic force microscopy

    International Nuclear Information System (INIS)

    Kindt, J H; Thurner, P J; Lauer, M E; Bosma, B L; Schitter, G; Fantner, G E; Izumi, M; Weaver, J C; Morse, D E; Hansma, P K

    2007-01-01

    The topography of freshly fractured bovine and human bone surfaces was determined by the use of atomic force microscopy (AFM). Fracture surfaces from both kinds of samples exhibited complex landscapes formed by hydroxyapatite mineral platelets with lateral dimensions ranging from ∼90 nm x 60 nm to ∼20 nm x 20 nm. Novel AFM techniques were used to study these fracture surfaces during various chemical treatments. Significant topographical changes were observed following exposure to aqueous solutions of ethylenediaminetetraacetic acid (EDTA) or highly concentrated sodium fluoride (NaF). Both treatments resulted in the apparent loss of the hydroxyapatite mineral platelets on a timescale of a few seconds. Collagen fibrils situated beneath the overlying mineral platelets were clearly exposed and could be resolved with high spatial resolution in the acquired AFM images. Time-dependent mass loss experiments revealed that the applied agents (NaF or EDTA) had very different resulting effects. Despite the fact that the two treatments exhibited nearly identical results following examination by AFM, bulk bone samples treated with EDTA exhibited a ∼70% mass loss after 72 h, whereas for the NaF-treated samples, the mass loss was only of the order of ∼10%. These results support those obtained from previous mechanical testing experiments, suggesting that enhanced formation of superficial fluoroapatite dramatically weakens the protein-hydroxyapatite interfaces. Additionally, we discovered that treatment with aqueous solutions of NaF resulted in the effective extraction of noncollagenous proteins from bone powder

  12. Bone-Forming Capabilities of a Newly Developed NanoHA Composite Alloplast Infused with Collagen: A Pilot Study in the Sheep Mandible

    Directory of Open Access Journals (Sweden)

    Charles Marin

    2013-01-01

    Full Text Available Lateral or vertical bone augmentation has always been a challenge, since the site is exposed to constant pressure from the soft tissue, and blood supply only exists from the donor site. Although, for such clinical cases, onlay grafting with autogenous bone is commonly selected, the invasiveness of the secondary surgical site and the relatively fast resorption rate have been reported as a drawback, which motivated the investigation of alternative approaches. This study evaluated the bone-forming capability of a novel nanoHA alloplast infused with collagen graft material made from biodegradable polylactic acid/polyglycolic acid versus a control graft material with the same synthesized alloplast without the nanoHA component and collagen infiltration. The status of newly formed bone and the resorption of the graft material were evaluated at 6 weeks in vivo histologically and three dimensionally by means of 3D microcomputed tomography. The histologic observation showed that newly formed bone ingrowth and internal resorption of the block were observed for the experimental blocks, whereas for the control blocks less bone ingrowth occurred along with lower resorption rate of the block material. The three-dimensional observation indicated that the experimental block maintained the external geometry, but at the same time successfully altered the graft material into bone. It is suggested that the combination of numerous factors contributed to the bone ingrowth and the novel development could be an alternative bone grafting choice.

  13. Aquatic Habits of Cetacean Ancestors: Integrating Bone Microanatomy and Stable Isotopes.

    Science.gov (United States)

    Cooper, Lisa Noelle; Clementz, Mark T; Usip, Sharon; Bajpai, Sunil; Hussain, S Taseer; Hieronymus, Tobin L

    2016-12-01

    The earliest cetaceans were interpreted as semi-aquatic based on the presence of thickened bones and stable oxygen isotopes in tooth enamel. However, the origin of aquatic behaviors in cetacean relatives (e.g., raoellids, anthracotheres) remains unclear. This study reconstructs the origins of aquatic behaviors based on long bone microanatomy and stable oxygen isotopes of tooth enamel in modern and extinct cetartiodactylans. Our findings are congruent with published accounts that microanatomy can be a reliable indicator of aquatic behaviors in taxa that are obligatorily aquatic, and also highlight that some "semi-aquatic" behaviors (fleeing into the water to escape predation) may have a stronger relationship to bone microanatomy than others (herbivory in near-shore aquatic settings). Bone microanatomy is best considered with other lines of information in the land-to-sea transition of cetaceans, such as stable isotopes. This study extends our understanding of the progression of skeletal phenotypes associated with habitat shifts in the relatives of cetaceans. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  14. IL-17 promotes bone erosion in murine collagen-induced arthritis through loss of the receptor activator of NF-kappa B ligand/osteoprotegerin balance.

    NARCIS (Netherlands)

    Lubberts, G.J.H.; Bersselaar, L.A.M. van den; Oppers-Walgreen, B.; Schwarzenberger, P.; Coonen-de Roo, C.J.; Kolls, J.; Joosten, L.A.B.; Berg, W.B. van den

    2003-01-01

    IL-17 is a T cell-derived proinflammatory cytokine in experimental arthritis and is a stimulator of osteoclastogenesis in vitro. In this study, we report the effects of IL-17 overexpression (AdIL-17) in the knee joint of type II collagen-immunized mice on bone erosion and synovial receptor activator

  15. Collagen/hydroxyapatite scaffold enriched with polycaprolactone nanofibers, thrombocyte-rich solution and mesenchymal stem cells promotes regeneration in large bone defect in vivo

    Czech Academy of Sciences Publication Activity Database

    Prosecká, Eva; Rampichová, Michala; Litvinec, Andrej; Tonar, Z.; Králíčková, M.; Vojtová, L.; Kochová, P.; Plencner, Martin; Buzgo, Matej; Míčková, Andrea; Jančář, J.; Amler, Evžen

    2015-01-01

    Roč. 103, č. 2 (2015), s. 671-682 ISSN 1549-3296 Institutional support: RVO:68378041 Keywords : bone regeneration * mesenchymal stem cells * collagen/hydroxyapatite scaffold Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.263, year: 2015

  16. [Comparative analysis and clinical experience with osteoplastic materials materials based on non-demineralized bone collagen and artificial hydroxylapatite at the close of bone defects in ambulatory surgical dentistry].

    Science.gov (United States)

    Dunaev, M V; Kitaev, V A; Matavkina, M V; Druzhinin, A E; Bubnov, A S

    2014-01-01

    In the presence of bone defects during surgery is not always performed osteoptastic material replenishment defect that leads to a lengthening of the timing healing, bone regeneration, and treatment outcome. Application of osteoplastic materials allows for faster treatment outcomes, accelerate the regeneration of bone tissue in the area of the defect. To examine the effectiveness of materials based on non-demineralized bone collagen and artificial hydroxylapatite when filling bone defects in outpatient surgical practice dentistry. 22 patients with bone defects of various localization using osteoplastic materials were examined and treated. In our study, two groups were allocated on the etiology of bone loss: radicular cysts and chronic generalized periodontitis. Basic methods of diagnosis and monitoring of treatment in the work presented with the cone-beam computed tomography and digital orthopantomography. Application of the testing osteoplastic materials resulted in faster recovery times with a combination of bone defects using resorbable membranes or gel enriched fibrin. In all 22 patients both tested materials were well tolerated, allergic reactions were not identified. However, five patients with a history of endocrinological history, during which treatment material is applied on the basis non-demineralized bone collagen, the degree of osseointegration has been reduced by 25% compared to the somatic healthy patients. In 3 patients with a history of hematological history, during which the treatment was applied material on the basis of artificial hydroxyapatite, the regeneration of the bone defect was reduced by 20%, which suggests the influence of somatic condition of the patient on the regeneration of bone tissue. Currently, all patients are on dynamic monitoring, recurrence has been detected. Materials based on non-demineralized bone collagen and hydroxyapatite artificial equally successful during the replacement of the bone defect during surgery. However, the

  17. Conservative treatment of bone tissue metabolic disorders among patients with vitamin D-dependent rickets type II with genetic abnormality of type I collagen formation

    Directory of Open Access Journals (Sweden)

    S.M. Martsyniak

    2017-08-01

    Full Text Available Background. The purpose of the article is to determine the effect of conservative therapy on genetically caused disorders of bone tissue metabolism in patients with vitamin D-dependent rickets type II and genetic abnormality of type I collagen formation (VDDR(COL1. Materials and methods. At the premises of consulting and outpatient department of SI “Institute of Traumatology and Orthopaedics of the NAMS of Ukraine”, 13 patients having VDDR type II and genetic damage of type I collagen formation were examined and treated. The medical treatment was conducted in four stages. The first stage included full examination of patients (calcium and phosphorus levels in the blood serum and their urinary excretion, as well as determination of calcidiol and calcitriol serum levels, indicators of parathyroid hormone and osteocalcin, and a marker of bone formation P1NP and osteoresorption b-CTx. At this stage, children were obligated to undergo a genetic test to detect changes (polymorphism in alleles of receptors to vitamin D and type I collagen. Besides genetic tests, examinations at the other stages were conducted in full. Results. The study has shown the following. The genetically caused abnormality of reception to vitamin D results into substantial accumulation of vitamin D active metabolite in the blood serum. When combined with gene­tic abnormality of type I collagen formation, it significantly affected bone formation and destruction processes that causes development of osteomalacia (parathormone — vitamin D — osteocalcin system. The comprehensive study of vitamin D metabolism and biochemical vitals of bone tissue in patients having VDDR (COL1 brought us to understanding of some issues related to pathogenesis and nature of osteomalacia and, in future, osteoporotic changes on different levels, ensured us to express these changes by corresponding indices in the biochemical research and, finally, to develop appropriate schemes for the treatment of

  18. A New Bone Substitute Developed from 3D-Prints of Polylactide (PLA Loaded with Collagen I: An In Vitro Study

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    Ulrike Ritz

    2017-11-01

    Full Text Available Although a lot of research has been performed, large segmental bone defects caused by trauma, infection, bone tumors or revision surgeries still represent big challenges for trauma surgeons. New and innovative bone substitutes are needed. Three-dimensional (3D printing is a novel procedure to create 3D porous scaffolds that can be used for bone tissue engineering. In the present study, solid discs as well as porous cage-like 3D prints made of polylactide (PLA are coated or filled with collagen, respectively, and tested for biocompatibility and endotoxin contamination. Microscopic analyses as well as proliferation assays were performed using various cell types on PLA discs. Stromal-derived factor (SDF-1 release from cages filled with collagen was analyzed and the effect on endothelial cells tested. This study confirms the biocompatibility of PLA and demonstrates an endotoxin contamination clearly below the FDA (Food and Drug Administration limit. Cells of various cell types (osteoblasts, osteoblast-like cells, fibroblasts and endothelial cells grow, spread and proliferate on PLA-printed discs. PLA cages loaded with SDF-1 collagen display a steady SDF-1 release, support cell growth of endothelial cells and induce neo-vessel formation. These results demonstrate the potential for PLA scaffolds printed with an inexpensive desktop printer in medical applications, for example, in bone tissue engineering.

  19. A New Bone Substitute Developed from 3D-Prints of Polylactide (PLA) Loaded with Collagen I: An In Vitro Study.

    Science.gov (United States)

    Ritz, Ulrike; Gerke, Rebekka; Götz, Hermann; Stein, Stefan; Rommens, Pol Maria

    2017-11-29

    Although a lot of research has been performed, large segmental bone defects caused by trauma, infection, bone tumors or revision surgeries still represent big challenges for trauma surgeons. New and innovative bone substitutes are needed. Three-dimensional (3D) printing is a novel procedure to create 3D porous scaffolds that can be used for bone tissue engineering. In the present study, solid discs as well as porous cage-like 3D prints made of polylactide (PLA) are coated or filled with collagen, respectively, and tested for biocompatibility and endotoxin contamination. Microscopic analyses as well as proliferation assays were performed using various cell types on PLA discs. Stromal-derived factor (SDF-1) release from cages filled with collagen was analyzed and the effect on endothelial cells tested. This study confirms the biocompatibility of PLA and demonstrates an endotoxin contamination clearly below the FDA (Food and Drug Administration) limit. Cells of various cell types (osteoblasts, osteoblast-like cells, fibroblasts and endothelial cells) grow, spread and proliferate on PLA-printed discs. PLA cages loaded with SDF-1 collagen display a steady SDF-1 release, support cell growth of endothelial cells and induce neo-vessel formation. These results demonstrate the potential for PLA scaffolds printed with an inexpensive desktop printer in medical applications, for example, in bone tissue engineering.

  20. Assessing the extent of bone degradation using glutamine deamidation in collagen.

    Science.gov (United States)

    Wilson, Julie; van Doorn, Nienke L; Collins, Matthew J

    2012-11-06

    Collagen peptides are analyzed using a low-cost, high-throughput method for assessing deamidation using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). For each chosen peptide, the theoretical distribution is calculated and the measured distribution for each sample compared with this to determine the extent of glutamine deamidation. The deamidation of glutamine (Q) to glutamic acid (E) results in a mass shift of +0.984 Da. Thus, from the resolution of our data, the second peak in the isotope distribution for a peptide containing one glutamine residue coincides with the first peak of the isotope distribution for the peptide in which the residue is deamidated. A genetic algorithm is used to determine the extent of deamidation that gives the best fit to the measured distribution. The method can be extended to peptides containing more than one glutamine residue. The extent of protein degradation assessed in this way could be used, for example, to assess the damage of collagen, and screen samples for radiocarbon dating and DNA analysis.

  1. Modelling collagen diseases: STRUCTURAL BIOLOGY

    OpenAIRE

    Brodsky, Barbara; Baum, Jean

    2008-01-01

    Mutations in collagen lead to hereditary disorders such as brittle-bone disease. Peptide models for aberrant collagens are beginning to clarify how these amino-acid replacements lead to clinical problems.

  2. Low-level laser therapy induces an upregulation of collagen gene expression during the initial process of bone healing: a microarray analysis

    Science.gov (United States)

    Tim, Carla Roberta; Bossini, Paulo Sérgio; Kido, Hueliton Wilian; Malavazi, Iran; von Zeska Kress, Marcia Regina; Carazzolle, Marcelo Falsarella; Rennó, Ana Cláudia; Parizotto, Nivaldo Antonio

    2016-08-01

    This study investigates the histological modifications produced by low level laser therapy (LLLT) on the first day of bone repair, as well as evaluates the LLLT effects on collagen expression on the site of a fracture. Twenty Wistar rats were distributed into a control group (CG) and a laser group (LG). Laser irradiation of Ga-Al-As laser 830 nm, 30 mW, 94 s, 2.8 J was performed in five sessions. Animals were euthanized on day 5 postsurgery. Histopathological analysis showed that LLLT was able to increase deposition of granulation tissue and newly formed bone at the site of the injury. In addition, picrosirius analysis showed that collagen fiber organization in the LG was enhanced compared to CG. Microarray analysis demonstrated that LLLT produced an upregulation type I collagen (COL-I). Immunohistochemical analysis revealed that the subjects that were treated presented a higher immunoexpression of COL-I. Our findings indicated that LLLT improves bone healing by producing a significant increase in the expression of collagen genes.

  3. Assessment of collagen quality associated with non-enzymatic cross-links in human bone using Fourier-transform infrared imaging.

    Science.gov (United States)

    Schmidt, F N; Zimmermann, E A; Campbell, G M; Sroga, G E; Püschel, K; Amling, M; Tang, S Y; Vashishth, D; Busse, B

    2017-04-01

    Aging and many disease conditions, most notably diabetes, are associated with the accumulation of non-enzymatic cross-links in the bone matrix. The non-enzymatic cross-links, also known as advanced glycation end products (AGEs), occur at the collagen tissue level, where they are associated with reduced plasticity and increased fracture risk. In this study, Fourier-transform infrared (FTIR) imaging was used to detect spectroscopic changes associated with the formation of non-enzymatic cross-links in human bone collagen. Here, the non-enzymatic cross-link profile was investigated in one cohort with an in vitro ribose treatment as well as another cohort with an in vivo bisphosphonate treatment. With FTIR imaging, the two-dimensional (2D) spatial distribution of collagen quality associated with non-enzymatic cross-links was measured through the area ratio of the 1678/1692cm -1 subbands within the amide I peak, termed the non-enzymatic crosslink-ratio (NE-xLR). The NE-xLR increased by 35% in the ribation treatment group in comparison to controls (p<0.005), with interstitial bone tissue being more susceptible to the formation of non-enzymatic cross-links. Ultra high-performance liquid chromatography, fluorescence microscopy, and fluorometric assay confirm a correlation between the non-enzymatic cross-link content and the NE-xLR ratio in the control and ribated groups. High resolution FTIR imaging of the 2D bone microstructure revealed enhanced accumulation of non-enzymatic cross-links in bone regions with higher tissue age (i.e., interstitial bone). This non-enzymatic cross-link ratio (NE-xLR) enables researchers to study not only the overall content of AGEs in the bone but also its spatial distribution, which varies with skeletal aging and diabetes mellitus and provides an additional measure of bone's propensity to fracture. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Fe and Cu stable isotopes in archeological human bones and their relationship to sex.

    Science.gov (United States)

    Jaouen, Klervia; Balter, Vincent; Herrscher, Estelle; Lamboux, Aline; Telouk, Philippe; Albarède, Francis

    2012-07-01

    Accurate sex assignment of ancient human remains usually relies on the availability of coxal bones or well-preserved DNA. Iron (Fe) and copper (Cu) stable isotope compositions ((56)Fe/(54)Fe and (65)Cu/(63)Cu, respectively) were recently measured in modern human blood, and an unexpected result was the discovery of a (56)Fe-depletion and a (65)Cu-enrichment in men's blood compared to women's blood. Bones, being pervasively irrigated by blood, are expected to retain the (56)Fe/(54)Fe and (65)Cu/(63)Cu signature of blood, which in turn is useful for determining the sex of ancient bones. Here, we report the (56)Fe/(54)Fe, (65)Cu/(63)Cu, and (66)Zn/(64)Zn ratios from a suite of well-preserved phalanxes (n = 43) belonging to individuals buried in the 17th and 18th centuries at the necropolis of Saint-Laurent de Grenoble, France, and for which the sex was independently estimated from pelvic bone morphology. The metals were purified from the bone matrix by liquid chromatography on ion exchange resin and the isotope compositions were measured by multiple-collector inductively coupled plasma mass spectrometry. The results show that, as expected from literature data on blood, male bone iron is depleted in (56)Fe and enriched in (65)Cu relative to female. No sex difference is found in the (66)Zn/(64)Zn ratios of bone. The concentration and isotopic data show no evidence of soil contamination. Four samples of five (77%) can be assigned their correct sex, a result comparable to sex assignment using Fe and Cu isotopes in blood (81%). Isotopic analysis of metals may therefore represent a valid method of sex assignment applicable to incomplete human remains. Copyright © 2012 Wiley Periodicals, Inc.

  5. Fabrication of micro/nanoporous collagen/dECM/silk-fibroin biocomposite scaffolds using a low temperature 3D printing process for bone tissue regeneration.

    Science.gov (United States)

    Lee, Hyeongjin; Yang, Gi Hoon; Kim, Minseong; Lee, JaeYoon; Huh, JunTae; Kim, GeunHyung

    2018-03-01

    Biomaterials must be biocompatible, biodegradable, and mechanically stable to be used for tissue engineering applications. Among various biomaterials, a natural-based biopolymer, collagen, has been widely applied in tissue engineering because of its outstanding biocompatibility. However, due to its low mechanical properties, collagen has been a challenge to build a desired/complex 3D porous structure with appropriate mechanical strength. To overcome this problem, in this study, we used a low temperature printing process to create a 3D porous scaffold consisting of collagen, decellularized extracellular matrix (dECM) to induce high cellular activities, and silk-fibroin (SF) to attain the proper mechanical strength. To show the feasibility of the scaffold, pre-osteoblast (MC3T3-E1) cells were grown on the fabricated scaffold. Various in vitro cellular activities (cell-viability, MTT assay, and osteogenic activity) for pure collagen, collagen/dECM, and collagen/SF/dECM scaffolds were compared. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. In vitro osteogenic potential of collagen/chitosan-based hydrogels-silica particles hybrids in human bone marrow-derived mesenchymal stromal cell cultures.

    Science.gov (United States)

    Filipowska, Joanna; Lewandowska-Łańcucka, Joanna; Gilarska, Adriana; Niedźwiedzki, Łukasz; Nowakowska, Maria

    2018-03-08

    The aim of this study was to assess osteogenic potential of three groups of biopolymeric hydrogel-based surfaces made of plain collagen, chitosan or collagen/chitosan, crosslinked with genipin or all three biopolymers modified with silica particles of two sizes (S1=240nm and S2=450nm). Biocompatibility and osteoinductive properties of the resulting composites were analyzed in the human bone marrow-derived mesenchymal stromal cells (hBMSCs) in vitro cultures. It was revealed that all tested materials are biocompatible and significantly enhance ALP activity in hBMSCs which was particularly pronounced for collagen/chitosan based hybrids. Gene expression (RUNX-2, COL-I, OC and VEGF mRNA) analyses performed in hBMSCs cultured at collagen/chitosan materials showed that ColChS1 hybrid the most effectively promotes osteogenic differentiation of hBMSCs. SEM and EDS analyses of materials carried out after 20days of hBMSCs culturing on ColCh-based hydrogels revealed that the hybrid materials enhanced hBMSCs-mediated mineralization of ECM. Our studies revealed that collagen/chitosan hydrogels modified with silica particles of smaller sizes (ColChS1) exhibit high pro-osteogenic properties without the need of applying any additional osteogenic inducers. That suggests that ColChS1 having the intrinsic osteoinductive activity holds great potential as material of choice for bone regeneration procedures, especially in regeneration of small bone losses. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Controlled release of vascular endothelial growth factor from spray-dried alginate microparticles in collagen-hydroxyapatite scaffolds for promoting vascularization and bone repair.

    Science.gov (United States)

    Quinlan, Elaine; López-Noriega, Adolfo; Thompson, Emmet M; Hibbitts, Alan; Cryan, Sally Ann; O'Brien, Fergal J

    2017-04-01

    A major limitation with current tissue-engineering approaches is creating functionally vascularized constructs that can successfully integrate with the host; this often leads to implant failure, due to avascular necrosis. In order to overcome this, the objective of the present work was to develop a method to incorporate growth factor-eluting alginate microparticles (MPs) into freeze-dried, collagen-based scaffolds. A collagen-hydroxyapatite (CHA) scaffold, previously optimized for bone regeneration, was functionalized for the sustained delivery of an angiogenic growth factor, vascular endothelial growth factor (VEGF), with the aim of facilitating angiogenesis and enhancing bone regeneration. VEGF was initially encapsulated in alginate MPs by spray-drying, producing particles of functionalized scaffold, composed entirely of natural-based materials, may offer an ideal platform to promote angiogenesis and tissue regeneration. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Statistical model of the habit and arrangement of mineral crystals in the collagen of bone

    Science.gov (United States)

    Fratzl, Peter

    1994-10-01

    Randomly colored space tesselations are considered as models for the mineral/organic structure of bone. First, it is shown that the structure function for such models is always proportional to the average form factor of the individual tiles and hence independent of the mineral density in the sample. Then the structure function is calculated for three such models: for model I, based on a hexagonal, and model 2, on a Poisson-Voronoi tesselation of the plane and for model 3, based on a random tesselation of the line. These results are compared to experimental structure functions measured by small-angle scattering and excellent agreement is obtained between model 2 and the bone from mice and rats, as well as between model 3 and calcified turkey leg tendon. Divergent conclusions following recent experiments by small-angle x-ray scattering and by electron microscopy are discussed in the light of these structural models and an explanation is proposed which might remove the discrepancy.

  9. Transdifferentiation of autologous bone marrow cells on a collagen-poly(ε-caprolactone) scaffold for tissue engineering in complete lack of native urothelium.

    Science.gov (United States)

    Zhao, J; Zeiai, S; Ekblad, A; Nordenskjöld, A; Hilborn, J; Götherström, C; Fossum, M

    2014-07-06

    Urological reconstructive surgery is sometimes hampered by a lack of tissue. In some cases, autologous urothelial cells (UCs) are not available for cell expansion and ordinary tissue engineering. In these cases, we wanted to explore whether autologous mesenchymal stem cells (MSCs) from bone marrow could be used to create urological transplants. MSCs from human bone marrow were cultured in vitro with medium conditioned by normal human UCs or by indirect co-culturing in culture well inserts. Changes in gene expression, protein expression and cell morphology were studied after two weeks using western blot, RT-PCR and immune staining. Cells cultured in standard epithelial growth medium served as controls. Bone marrow MSCs changed their phenotype with respect to growth characteristics and cell morphology, as well as gene and protein expression, to a UC lineage in both culture methods, but not in controls. Urothelial differentiation was also accomplished in human bone marrow MSCs seeded on a three-dimensional poly(ε-caprolactone) (PCL)-collagen construct. Human MSCs could easily be harvested by bone marrow aspiration and expanded and differentiated into urothelium. Differentiation could take place on a three-dimensional hybrid PCL-reinforced collagen-based scaffold for creation of a tissue-engineered autologous transplant for urological reconstructive surgery.

  10. Association of Sp1 Collagen Type Iα1 Gene Polymorphisms with Bone Mineral Density in Bulgarian Women Referred for Bone Densitometry

    Directory of Open Access Journals (Sweden)

    Andon K. Toshev

    2011-09-01

    Full Text Available Objectives: To investigate the association between bone mineral density (BMD and collagen type Iα1 (COLIA1 gene polymorphisms in a case-control study.Materials and Methods: 400 unrelated postmenopausal Bulgarian women participated - 180 with normal BMD and 220 with low BMD. BMD was measured at the forearm, lumbar spine and femoral neck by X-ray absorptiometry. A PCR product of 261 bp was digested and electrophoresed. The prevalence of S and s alleles as well as the different genotypes was determined. All analyses were tested for statistical significance (c2-test.Results: 408 s and 392 S alleles were found. Of the 220 women with low BMD, 20 had the SS genotype, 94 – the Ss genotype, and 106 – the ss genotype. Among the 180 controls with normal BMD, 93 had the SS genotype, 76 - the Ss, and 11 – the ss genotype. The SS genotype was associated with higher BMD and the ss – with lower BMD at all sites. The odds ratio for low BMD in the presence of the ss genotype was 10.69.Conclusion: In our study sample, the COLIA1 polymorphism was associated with low BMD. This particular genetic polymorphism may become a useful genetic screening tool for osteoporosis. Türk Jem 2011; 15: 66-70

  11. Evaluation of RNA from human trabecular bone and identification of stable reference genes.

    Science.gov (United States)

    Cepollaro, Simona; Della Bella, Elena; de Biase, Dario; Visani, Michela; Fini, Milena

    2018-06-01

    The isolation of good quality RNA from tissues is an essential prerequisite for gene expression analysis to study pathophysiological processes. This study evaluated the RNA isolated from human trabecular bone and defined a set of stable reference genes. After pulverization, RNA was extracted with a phenol/chloroform method and then purified using silica columns. The A260/280 ratio, A260/230 ratio, RIN, and ribosomal ratio were measured to evaluate RNA quality and integrity. Moreover, the expression of six candidates was analyzed by qPCR and different algorithms were applied to assess reference gene stability. A good purity and quality of RNA was achieved according to A260/280 and A260/230 ratios, and RIN values. TBP, YWHAZ, and PGK1 were the most stable reference genes that should be used for gene expression analysis. In summary, the method proposed is suitable for gene expression evaluation in human bone and a set of reliable reference genes has been identified. © 2017 Wiley Periodicals, Inc.

  12. Characterization of serological neo-epitope biomarkers reflecting collagen remodeling in clinically stable chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Sand, Jannie M B; Martinez, Gerd; Midjord, Anne-Kirsten

    2016-01-01

    OBJECTIVES: Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation that leads to excessive remodeling of the lung extracellular matrix (ECM), resulting in release of protein fragments (neo-epitopes) to the blood. Serological markers assessing this have previously been...... of COPD, blood oxygen saturation, shuttle walk test distance, GOLD grades, or CAT scores. CONCLUSIONS: Serological biomarkers of collagen remodeling were elevated in subjects with COPD as compared with healthy individuals. Biomarker levels were significantly correlated with measures of dyspnea, indicating...... a relationship with degree of symptoms, while only C6M showed a weak but significant association with lung function. Biomarker levels were not related to GOLD grades, which was in line with previous studies indicating that ECM remodeling may be related to disease activity rather than severity....

  13. The petrous bone

    DEFF Research Database (Denmark)

    Jørkov, Marie Louise Schjellerup; Heinemeier, Jan; Lynnerup, Niels

    2009-01-01

    Intraskeletal variation in the composition of carbon (delta(13)C) and nitrogen (delta(15)N) stable isotopes measured in collagen is tested from various human bones and dentine. Samples were taken from the femur, rib, and petrous part of the temporal bone from well-preserved skeletons of both adul...... of this study it is believed the petrous bone may be a new useful bone element and a supplement or a proxy for teeth in the analysis of early dietary patterns as it may reflect diet in fetal stages and early years of life....

  14. Improvement of the Chondrocyte-Specific Phenotype upon Equine Bone Marrow Mesenchymal Stem Cell Differentiation: Influence of Culture Time, Transforming Growth Factors and Type I Collagen siRNAs on the Differentiation Index

    Directory of Open Access Journals (Sweden)

    Thomas Branly

    2018-02-01

    Full Text Available Articular cartilage is a tissue characterized by its poor intrinsic capacity for self-repair. This tissue is frequently altered upon trauma or in osteoarthritis (OA, a degenerative disease that is currently incurable. Similar musculoskeletal disorders also affect horses and OA incurs considerable economic loss for the equine sector. In the view to develop new therapies for humans and horses, significant progress in tissue engineering has led to the emergence of new generations of cartilage therapy. Matrix-associated autologous chondrocyte implantation is an advanced 3D cell-based therapy that holds promise for cartilage repair. This study aims to improve the autologous chondrocyte implantation technique by using equine mesenchymal stem cells (MSCs from bone marrow differentiated into chondrocytes that can be implanted in the chondral lesion. The optimized protocol relies on culture under hypoxia within type I/III collagen sponges. Here, we explored three parameters that influence MSC differentiation: culture times, growth factors and RNA interference strategies. Our results suggest first that an increase in culture time from 14 to 28 or 42 days lead to a sharp increase in the expression of chondrocyte markers, notably type II collagen (especially the IIB isoform, along with a concomitant decrease in HtrA1 expression. Nevertheless, the expression of type I collagen also increased with longer culture times. Second, regarding the growth factor cocktail, TGF-β3 alone showed promising result but the previously tested association of BMP-2 and TGF-β1 better limits the expression of type I collagen. Third, RNA interference targeting Col1a2 as well as Col1a1 mRNA led to a more significant knockdown, compared with a conventional strategy targeting Col1a1 alone. This chondrogenic differentiation strategy showed a strong increase in the Col2a1:Col1a1 mRNA ratio in the chondrocytes derived from equine bone marrow MSCs, this ratio being considered as an

  15. Stable subcutaneous cartilage regeneration of bone marrow stromal cells directed by chondrocyte sheet.

    Science.gov (United States)

    Li, Dan; Zhu, Lian; Liu, Yu; Yin, Zongqi; Liu, Yi; Liu, Fangjun; He, Aijuan; Feng, Shaoqing; Zhang, Yixin; Zhang, Zhiyong; Zhang, Wenjie; Liu, Wei; Cao, Yilin; Zhou, Guangdong

    2017-05-01

    In vivo niche plays an important role in regulating differentiation fate of stem cells. Due to lack of proper chondrogenic niche, stable cartilage regeneration of bone marrow stromal cells (BMSCs) in subcutaneous environments is always a great challenge. This study explored the feasibility that chondrocyte sheet created chondrogenic niche retained chondrogenic phenotype of BMSC engineered cartilage (BEC) in subcutaneous environments. Porcine BMSCs were seeded into biodegradable scaffolds followed by 4weeks of chondrogenic induction in vitro to form BEC, which were wrapped with chondrocyte sheets (Sheet group), acellular small intestinal submucosa (SIS, SIS group), or nothing (Blank group) respectively and then implanted subcutaneously into nude mice to trace the maintenance of chondrogenic phenotype. The results showed that all the constructs in Sheet group displayed typical cartilaginous features with abundant lacunae and cartilage specific matrices deposition. These samples became more mature with prolonged in vivo implantation, and few signs of ossification were observed at all time points except for one sample that had not been wrapped completely. Cell labeling results in Sheet group further revealed that the implanted BEC directly participated in cartilage formation. Samples in both SIS and Blank groups mainly showed ossified tissue at all time points with partial fibrogenesis in a few samples. These results suggested that chondrocyte sheet could create a chondrogenic niche for retaining chondrogenic phenotype of BEC in subcutaneous environment and thus provide a novel research model for stable ectopic cartilage regeneration based on stem cells. In vivo niche plays an important role in directing differentiation fate of stem cells. Due to lack of proper chondrogenic niche, stable cartilage regeneration of bone marrow stromal cells (BMSCs) in subcutaneous environments is always a great challenge. The current study demonstrated that chondrocyte sheet generated by

  16. Complications of Elastic Stable Intramedullary Nailing for treating paediatric long bone fractures

    Science.gov (United States)

    Nisar, Aamer; Bhosale, Abhijit; Madan, Sanjeev S.; Flowers, Mark J.; Fernandes, James A.; Jones, Stanley

    2013-01-01

    This study reports the complications observed in children with long bone fractures treated using Elastic Stable Intramedullary Nailing (ESIN). One hundred and sixty-four (n = 164) fractures in 160 patients under the age of 16 years formed the basis of our review. This included 108 boys and 52 girls with the median age of 11 years and median follow up of 7.5 months. The analysis included fractures of the radius/ulna, humerus, femur and tibia. All pathological fractures were excluded. In this series 54 patients (34%) had complications however majority of these were minor complications with irritation due to prominent nail ends being the commonest complication. No long-term sequelae were encountered in our patients. PMID:24403743

  17. Fabrication of human hair keratin/jellyfish collagen/eggshell-derived hydroxyapatite osteoinductive biocomposite scaffolds for bone tissue engineering: From waste to regenerative medicine products.

    Science.gov (United States)

    Arslan, Yavuz Emre; Sezgin Arslan, Tugba; Derkus, Burak; Emregul, Emel; Emregul, Kaan C

    2017-06-01

    In the present study, we aimed at fabricating an osteoinductive biocomposite scaffold using keratin obtained from human hair, jellyfish collagen and eggshell-derived nano-sized spherical hydroxyapatite (nHA) for bone tissue engineering applications. Keratin, collagen and nHA were characterized with the modified Lowry method, free-sulfhydryl groups and hydroxyproline content analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR) and thermal gravimetric analysis (TGA) which confirmed the success of the extraction and/or isolation processes. Human adipose mesenchymal stem cells (hAMSCs) were isolated and the cell surface markers were characterized via flow cytometry analysis in addition to multilineage differentiation capacity. The undifferentiated hAMSCs were highly positive for CD29, CD44, CD73, CD90 and CD105, but were not seen to express hematopoietic cell surface markers such as CD14, CD34 and CD45. The cells were successfully directed towards osteogenic, chondrogenic and adipogenic lineages in vitro. The microarchitecture of the scaffolds and cell attachment were evaluated using scanning electron microscopy (SEM). The cell viability on the scaffolds was assessed by the MTT assay which revealed no evidence of cytotoxicity. The osteogenic differentiation of hAMSCs on the scaffolds was determined histologically using alizarin red S, osteopontin and osteonectin stainings. Early osteogenic differentiation markers of hAMSCs were significantly expressed on the collagen-keratin-nHA scaffolds. In conclusion, it is believed that collagen-keratin-nHA osteoinductive biocomposite scaffolds have the potential of being used in bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Why collagens best survived in fossils? Clues from amino acid thermal stability.

    Science.gov (United States)

    Wang, Shuang-Yin; Cappellini, Enrico; Zhang, Hong-Yu

    2012-05-25

    Explaining why type I collagens are preferentially preserved in the geological time scale remains a challenge. Several pieces of evidence indicate that its rich content in the bone and its unique, stable structure played key roles in its preservation. By considering the distinct thermal stability of amino acids, we reveal that the elevated abundance of thermostable amino acid residues in type I collagens also contribute to its survival. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Quaternary chronostratigraphy and stable isotope paleoecology of Big Bone Lick, Kentucky, USA

    Science.gov (United States)

    Tankersley, Kenneth Barnett; Murari, Madhav Krishna; Crowley, Brooke E.; Owen, Lewis A.; Storrs, Glenn W.; Mortensen, Litsa

    2015-05-01

    Big Bone Lick (BBL) in northern Kentucky, USA has been a critical geologic site in the historical development of North American Quaternary vertebrate paleontology since the 1700s. Sedimentology, geoarcheology, paleontology, accelerator mass spectrometry radiocarbon and optically stimulated luminescence dating, and stable carbon and nitrogen isotope analyses were undertaken to develop a chronostratigraphy and history of erosion and deposition for the site to provide a foundation for understanding taphonomy, and species extinction and adaptation to periods of climatic and environmental change. Three geomorphic surfaces are recognized at BBL representing significant periods of floodplain aggradation since the last glacial maximum (26.5-19 ka) dating to the Oldest Dryas (Tazewell, 25-19 ka), the Older Dryas (Cary, 14-12 ka), and late Holocene (5 ka to the present). Unconformities suggest significant periods of degradation during the transitions from cold and dry to warm and moist climates from the Oldest Dryas (Tazewell) to Bølling Oscillation, from the Older Dryas (Cary) to the Allerød, and from the Younger Dryas (Valders) to the Holocene Climatic Optimum. Increased anthropogenic activities since 5 ka may have increased soil upland erosion and floodplain aggradation. Stable isotopes demonstrate that the landscape has been dominated by C3 vegetation since the last glacial maximum.

  20. Retrospective Study of Anterior Interbody Fusion Rates and Patient Outcomes of Using Mineralized Collagen and Bone Marrow Aspirate in Multilevel Adult Spinal Deformity Surgery.

    Science.gov (United States)

    Hostin, Richard; O'Brien, Michael; McCarthy, Ian; Bess, Shay; Gupta, Munish; Klineberg, Eric

    2016-10-01

    Retrospective, single-center analysis of multilevel anterior fusion rates and health-related quality-of-life outcomes of mineralized collagen and bone marrow aspirate (BMA) in anterior interbody fusion cages for spine fusion surgery. To determine the ability and effectiveness of mineralized collagen and BMA to achieve multilevel anterior spinal fusion in adult spinal deformity patients when placed in carbon fiber reinforced polymer cages. High rates of postoperative pain and nonunion can result from spine fusion procedures. Factors that affect the success of fusion include patient comorbidities, position of implant, and mechanical and biological deficiencies, as well as the choice of bone graft replacement. Analysis of radiographic images and health-related quality-of-life outcomes was performed for a consecutive series of 22 prospectively enrolled adult spinal deformity patients with 104 total anterior fusion levels. Fusions were graded by 3 blinded surgeons not involved in the operative procedure; each fusion was graded on a 1-4 scale based on fusion mass appearance. Levels with an average fusion grade of 1-2.4 were classified as fused; levels with an average grade >2.5 were classified as not fused. The mean patient age was 51.5 years (range, 38-61) with 21 females. A total of 95% of anterior operative levels were graded as fused based on flexion/extension and full-length biplane radiographs at 1 year. Computed tomography grading showed a reduced fusion rate at 87% overall. There was a statistically significant improvement in the Oswestry Disability Index and Scoliosis Research Society 22-item questionnaire scores at 1 and 2 years after index surgery. Fusion rates in multilevel anterior spinal fusion using mineralized collagen and BMA are relatively low compared with fusion rates of 95% or more reported in the existing literature on long fusions with bone morphogenetic protein.

  1. Periodontal Regenerative Therapy of Intrabony Defects Using Deproteinized Bovine Bone Mineral in Combination with Collagen Barrier Membrane: A Multicenter Prospective Case-Series Study.

    Science.gov (United States)

    Irokawa, Daisuke; Okubo, Nobuki; Nikaido, Masahiko; Shimizu, Hiroyasu; Konobu, Hiroyuki; Matsui, Tokuo; Fujita, Takahisa; Goto, Hiroaki; Takeuchi, Takahiro; Ishii, Yoshihito; Saito, Atsushi

    This multicenter prospective case series study aimed to evaluate the outcome of periodontal regenerative therapy using a deproteinized bovine bone mineral (DBBM) in combination with a collagen barrier (CB) in the treatment of intrabony defects. A total of 36 nonsmoking patients with chronic periodontitis were recruited in five centers in Japan. All patients had at least one intrabony defect of ≥ 3 mm. The surgical procedures included access for debridement using a papilla preservation technique. Defects were filled with DBBM and covered with CB. Clinical evidence after 6 months supported the effectiveness of the combination therapy in the treatment of intrabony defects.

  2. Collagen/hydroxyapatite scaffold enriched with polycaprolactone nanofibers, thrombocyte-rich solution and mesenchymal stem cells promotes regeneration in large bone defect in vivo.

    Science.gov (United States)

    Prosecká, E; Rampichová, M; Litvinec, A; Tonar, Z; Králíčková, M; Vojtová, L; Kochová, P; Plencner, M; Buzgo, M; Míčková, A; Jančář, J; Amler, E

    2015-02-01

    A three-dimensional scaffold of type I collagen and hydroxyapatite enriched with polycaprolactone nanofibers (Coll/HA/PCL), autologous mesenchymal stem cells (MSCs) in osteogenic media, and thrombocyte-rich solution (TRS) was an optimal implant for bone regeneration in vivo in white rabbits. Nanofibers optimized the viscoelastic properties of the Coll/HA scaffold for bone regeneration. MSCs and TRS in the composite scaffold improved bone regeneration. Three types of Coll/HA/PCL scaffold were prepared: an MSC-enriched scaffold, a TRS-enriched scaffold, and a scaffold enriched with both MSCs and TRS. These scaffolds were implanted into femoral condyle defects 6 mm in diameter and 10-mm deep. Untreated defects were used as a control. Macroscopic and histological analyses of the regenerated tissue from all groups were performed 12 weeks after implantation. The highest volume and most uniform distribution of newly formed bone occurred in defects treated with scaffolds enriched with both MSCs and TRS compared with that in defects treated with scaffolds enriched by either component alone. The modulus of elasticity in compressive testing was significantly higher in the Coll/HA/PCL scaffold than those without nanofibers. The composite Coll scaffold functionalized with PCL nanofibers and enriched with MSCs and TRS appears to be a novel treatment for bone defects. © 2014 Wiley Periodicals, Inc.

  3. Evaluation of autogenous PRGF+β-TCP with or without a collagen membrane on bone formation and implant osseointegration in large size bone defects. A preclinical in vivo study.

    Science.gov (United States)

    Batas, Leonidas; Stavropoulos, Andreas; Papadimitriou, Serafim; Nyengaard, Jens R; Konstantinidis, Antonios

    2016-08-01

    The aim of this study was to evaluate whether the adjunctive use of a collagen membrane enhances bone formation and implant osseointegration in non-contained defects grafted with chair-side prepared autologous platelet-rich growth factor (PRGF) adsorbed on a β-TCP particulate carrier. Large box-type defects (10 × 6 mm; W × D) were prepared in the edentulated and completely healed mandibles of six Beagles dogs. An implant with moderately rough surface was placed in the center of each defect leaving the coronal 6 mm of the implant not covered with bone. The remaining defect space was then filled out with chair-side prepared autologous PRGF adsorbed on β-TCP particles and either covered with a collagen membrane (PRGF/β-TCP+CM) (6 defects) or left without a membrane (PRGF/β-TCP) (5 defects). Histology 4 months post-op showed new lamellar and woven bone formation encompassing almost entirely the defect and limited residual β-TCP particles. Extent of osseointegration of the previously exposed portion of the implants varied, but in general was limited. Within the defect, new mineralized bone (%) averaged 43.2 ± 9.86 vs. 39.9 ± 13.7 in the PRGF/β-TCP+CM and PRGF/β-TCP group (P = 0.22) and relative mineralized bone-to-implant contact (%) averaged 26.2 ± 16.45 vs. 35.91 ± 24.45, respectively (P = 0.5). First, bone-to-implant contact from the implant top was 4.1 ± 1.5 and 3.2 ± 2.3 (P = 0.9), in the PRGF/β-TCP+CM and PRGF/β-TCP group, respectively. Implantation of chair-side prepared autologous PRGF adsorbed on a β-TCP carrier in non-contained peri-implant defects resulted in large amounts of bone regeneration, but osseointegration was limited. Provisions for GBR with a collagen membrane did not significantly enhance bone regeneration or implant osseointegration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. The carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen in serum as a marker of bone resorption

    DEFF Research Database (Denmark)

    Hassager, C; Jensen, L T; Pødenphant, J

    1994-01-01

    Carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP) in serum has recently been proposed as a new biochemical marker of bone resorption. In the present study we compared serum ICTP with radiopharmaceutical and histomorphometric measurements of bone turnover...... in postmenopausal women with mild osteoporosis, and assessed the effect of hormone replacement therapy (HRT) (2 mg 17 beta-estradiol plus 1 mg norethisterone daily) and anabolic steroid therapy (50 mg nandrolone decanoate (ND) i.m. every 3 weeks) on serum ICTP in two double-blind placebo-controlled studies with 55...... to 75-year-old women. Serum ICTP measured by radioimmunoassay (RIA) correlated significantly with the 24-hour whole body retention of 99m-technetium diphosphonate (Rho = 0.47, P

  5. Collagen hydrolysate based collagen/hydroxyapatite composite materials

    Science.gov (United States)

    Ficai, Anton; Albu, Madalina Georgiana; Birsan, Mihaela; Sonmez, Maria; Ficai, Denisa; Trandafir, Viorica; Andronescu, Ecaterina

    2013-04-01

    The aim of this study was to study the influence of collagen hydrolysate (HAS) on the formation of ternary collagen-hydrolysate/hydroxyapatite composite materials (COLL-HAS/HA). During the precipitation process of HA, a large amount of brushite is resulted at pH = 7 but, practically pure HA is obtained at pH ⩾ 8. The FTIR data reveal the duplication of the most important collagen absorption bands due to the presence of the collagen hydrolysate. The presence of collagen hydrolysate is beneficial for the management of bone and joint disorders such as osteoarthritis and osteoporosis.

  6. Incorporation of polymeric microparticles into collagen-hydroxyapatite scaffolds for the delivery of a pro-osteogenic peptide for bone tissue engineering

    Science.gov (United States)

    López-Noriega, Adolfo; Quinlan, Elaine; Celikkin, Nehar; O'Brien, Fergal J.

    2015-01-01

    Collagen-hydroxyapatite scaffolds are outstanding materials for bone tissue engineering as they are biocompatible, bioresorbable, osteoconductive, and osteoinductive. The objective of the present work was to assess the potential of increasing their regenerative capacity by functionalising the scaffolds for therapeutic delivery. This was achieved by the utilization of polymeric drug carriers. With this purpose, alginate, chitosan, gelatine, and poly(lactic-co-glycolic acid) (PLGA) microparticles eluting PTHrP 107-111, an osteogenic pentapeptide, were fabricated and tested by incorporating them into the scaffolds. Among them, PLGA microparticles show the most promising characteristics for use as drug delivery devices. Following the incorporation of the microparticles, the scaffolds maintained their interconnected porous structure and the mechanical properties of the materials were not adversely affected. In addition, the microparticles released all their PTHrP 107-111 cargo. Most importantly, the delivered peptide proved to be bioactive and promoted enhanced osteogenesis as assessed by alkaline phosphatase production and osteocalcin and osteopontin gene expression when pre-osteoblastic cells were seeded on the scaffolds. While the focus was on bone repair, the release system described in this study can be used for the delivery of therapeutics for healing and regeneration of a variety of tissue types depending on the type of collagen scaffold chosen.

  7. A new composite hydrogel combining the biological properties of collagen with the mechanical properties of a supramolecular scaffold for bone tissue engineering.

    Science.gov (United States)

    Maisani, Mathieu; Ziane, Sophia; Ehret, Camille; Levesque, Lucie; Siadous, Robin; Le Meins, Jean-François; Chevallier, Pascale; Barthélémy, Philippe; De Oliveira, Hugo; Amédée, Joëlle; Mantovani, Diego; Chassande, Olivier

    2018-03-01

    Tissue engineering is a promising alternative to autografts, allografts, or biomaterials to address the treatment of severe and large bone lesions. Classically, tissue engineering products associate a scaffold and cells and are implanted or injected into the lesion. These cells must be embedded in an appropriate biocompatible scaffold, which offers a favourable environment for their survival and differentiation. Here, we designed a composite hydrogel composed of collagen I, an extracellular matrix protein widely used in several therapeutic applications, which we associated with a physical hydrogel generated from a synthetic small amphiphilic molecule. This composite showed improved mechanical and biological characteristics as compared with gels obtained from each separate compound. Incorporation of the physical hydrogel prevented shrinkage of collagen and cell diffusion out of the gel and yielded a gel with a higher elastic modulus than those of gels obtained with each component alone. The composite hydrogel allowed cell adhesion and proliferation in vitro and long-term cell survival in vivo. Moreover, it promoted the differentiation of human adipose-derived stem cells in the absence of any osteogenic factors. In vivo, cells embedded in the composite gel and injected subcutaneously in immunodeficient mice produced lamellar osteoid tissue and differentiated into osteoblasts. This study points this new composite hydrogel as a promising scaffold for bone tissue engineering applications. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Evaluation of bone marrow stem cell response to PLA scaffolds manufactured by 3D printing and coated with polydopamine and type I collagen.

    Science.gov (United States)

    Teixeira, Bruna Nunes; Aprile, Paola; Mendonça, Roberta H; Kelly, Daniel J; Thiré, Rossana Mara da Silva Moreira

    2018-02-26

    The majority of synthetic polymers used in 3 D printing are not designed to promote specific cellular interactions and hence possess limited bioactivity. Most of the strategies proposed to overcome this limitation demand multiple and expensive processing steps. This study aimed to evaluate the surface modification of 3D-printed poly(lactic acid) (PLA) scaffolds with polydopamine (PDA) coating as an alternative strategy to enhance their bioactivity and to facilitate the immobilization of type I collagen (COL I) onto the implant surface. Physical and chemical properties of PLA scaffolds coated with PDA, COL I or both were evaluated. The response of porcine bone marrow stem cells (MSCs) to the coatings was also investigated. The PDA layer improved COL immobilization onto the surface of the PLA scaffolds by 92%. The combination of PDA and COL functionalizations provided the best conditions for early-stage (PLA and PDA plus COL-coated scaffolds by day 21, cells seeded onto PDA plus COL scaffolds produced substantially higher amounts of alkaline phosphatase. These results indicate that the osteoinductivity of 3D-printed PLA scaffolds can be enhanced by PDA and type I collagen coatings. This surface modification of polymeric scaffolds represents a promising strategy for bone tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

  9. Protective effect of Withania somnifera root powder in relation to lipid peroxidation, antioxidant status, glycoproteins and bone collagen on adjuvant-induced arthritis in rats.

    Science.gov (United States)

    Rasool, M; Varalakshmi, P

    2007-04-01

    The present investigation was carried out to evaluate the protective effect of Withania somnifera Linn. Dunal (family-Solanaceae), commonly known as Ashwagandha, on adjuvant-induced arthritic rats. Results were compared with those for Indomethacin, a nonsteroidal anti-inflammatory drug. Arthritis was induced by intradermal injection of complete Freund's adjuvant (0.1 mL) into the right hind paw of Wistar albino rats. Withania somnifera root powder (1000 mg/kg/day) and Indomethacin (3 mg/kg/day) were orally administered for 8 days (from 11th to 18th day) after adjuvant injection. The anti-arthritic effect of W. somnifera root powder was assessed by measuring changes in lipid peroxidation, antioxidant status, and glycoprotein levels in plasma and spleen of arthritic animals. In addition, cartilage degradation was also assessed by estimating bone collagen, and urinary constituents in arthritic animals. Results of the present investigation showed significant increase in the level of lipid peroxides, glycoproteins, and urinary constituents with the depletion of antioxidant status and bone collagen in arthritic animals. These biochemical alterations observed were ameliorated significantly by oral administration of W. somnifera root powder (1000 mg/kg body weight) in arthritic animals. The results of this study clearly indicate that W. somnifera root powder is capable of rectifying the above biochemical changes in adjuvant arthritis.

  10. Clinical comparison of guided tissue regeneration, with collagen membrane and bone graft, versus connective tissue graft in the treatment of gingival recessions

    Directory of Open Access Journals (Sweden)

    Haghighati F

    2006-06-01

    Full Text Available Background and Aim: Increasing patient demands for esthetic, put the root coverage procedures in particular attention. Periodontal regeneration with GTR based root coverage methods is the most common treatment used. The purpose of this study was to compare guided tissue regeneration (GTR with collagen membrane and a bone graft, with sub-epithelial connective tissue graft (SCTG, in treatment of gingival recession. Materials and Methods: In this randomized clinical trial study, eleven healthy patients with no systemic diseases who had miller’s class I or II recession defects (gingival recession  2mm were treated with SCTG or GTR using a collagen membrane and a bone graft. Clinical measurements were obtained at baseline and 6 months after surgery. These clinical measurements included recession depth (RD, recession width (RW, probing depth (PD, and clinical attachment level (CAL. Data were analyzed using independent t test with p<0.05 as the limit of significance. Results: Both treatment methods resulted in a statistically significant reduction of recession depth (SCTG=2.3mm, GTR=2.1mm; P<0.0001. CAL gain after 6 months was also improved in both groups (SCG= 2.5mm, GTR=2.1mm, compared to baseline (P<0.0001. No statistical differences were observed in RD, RW, CAL between test and control groups. Root coverage was similar in both methods (SCTG= 74.2%, GTR= 62.6%, P=0.87. Conclusion: Based on the results of this study, the two techniques are clinically comparable. Therefore the use of collagen membrane and a bovine derived xenograft may alleviate the need for connective tissue graft.

  11. Preparation of hydroxyapatite/collagen injectable bone paste with an anti-washout property utilizing sodium alginate. Part 1: influences of excess supplementation of calcium compounds.

    Science.gov (United States)

    Sato, Taira; Kikuchi, Masanori; Aizawa, Mamoru

    2017-03-01

    The anti-washout property, viscosity, and cytocompatibility to an osteoblastic cell line, MG-63, of anti-washout pastes were investigated. Mixing a hydroxyapatite/collagen bone-like nanocomposite (HAp/Col), an aqueous solution of sodium alginate (Na-Alg), which is a paste hardening and lubricant agent, and supplementation of calcium carbonate or calcium citrate (Ca-Cit) as a calcium resource for the hardening reaction realized an injectable bone paste. Adding Ca-Cit at a concentration greater than eight times the Ca 2+ ion concentration to Na-Alg improved the anti-washout property. Although the viscosity test indicated a gradual increase in the paste viscosity as the calcium compounds increased, pastes with excess supplementation of calcium compounds exhibited injectability through a syringe with a 1.8 mm inner diameter, realizing an injectable bone filler. Furthermore, the anti-washout pastes with Ca-Cit had almost the same cell proliferation rate as that of the HAp/Col dense body. Therefore, HAp/Col injectable anti-washout pastes composed of the HAp/Col, Na-Alg, and Ca-Cit are potential candidates for bioresorbable bone filler pastes.

  12. Collagenous Gastritis

    OpenAIRE

    Freeman, Hugh J.; Piercy, James R.A.; Raine, Robert J.

    1989-01-01

    A 54-year-old woman presented with nausea, vomiting and weight loss associated with impaired gastric emptying necessitating institution of parenteral nutrition. Subsequent studies revealed an unusual gastric mucosa! inflammatory process characterized by unique subepithelial collagenous deposits. Collagenous gastritis appears to be a distinct, possibly immune-mediated, chronic disorder, pathologically reminiscent of collagenous sprue and collagenous colitis.

  13. Rapidly Assessing Changes in Bone Mineral Balance Using Natural Stable Calcium Isotopes

    Science.gov (United States)

    Morgan, J. L. L.; Gordon, G. W.; Romaniello, S. J.; Skulan, J. L.; Smith, S. M.; Anbar, A. D.

    2011-01-01

    We demonstrate that variations in the Ca isotope ratios in urine rapidly and quantitatively reflect changes in bone mineral balance. This variation occurs because bone formation depletes soft tissue of light Ca isotopes, while bone resorption releases that isotopically light Ca back into soft tissue. In a study of 12 individuals confined to bed rest, a condition known to induce bone resorption, we show that Ca isotope ratios shift in a direction consistent with net bone loss after just 7 days, long before detectible changes in bone density occur. Consistent with this interpretation, the Ca isotope variations track changes observed in N-teleopeptide, a bone resorption biomarker, while bone-specific alkaline phosphatase, a bone formation biomarker, is unchanged. Ca isotopes can in principle be used to quantify net changes in bone mass. Ca isotopes indicate an average loss of 0.62 +/- 0.16 % in bone mass over the course of this 30-day study. The Ca isotope technique should accelerate the pace of discovery of new treatments for bone disease and provide novel insights into the dynamics of bone metabolism.

  14. Why collagens best survived in fossils? Clues from amino acid thermal stability

    DEFF Research Database (Denmark)

    Wang, Shuang-Yin; Cappellini, Enrico; Zhang, Hong-Yu

    2012-01-01

    Explaining why type I collagens are preferentially preserved in the geological time scale remains a challenge. Several pieces of evidence indicate that its rich content in the bone and its unique, stable structure played key roles in its preservation. By considering the distinct thermal stability...

  15. Collagen degradation as a possibility to determine the post-mortem interval (PMI) of animal bones: a validation study referring to an original study of Boaks et al. (2014).

    Science.gov (United States)

    Jellinghaus, Katharina; Hachmann, Carolin; Hoeland, Katharina; Bohnert, Michael; Wittwer-Backofen, Ursula

    2018-05-01

    Estimation of the post-mortem interval (PMI) of unknown skeletal remains is a common forensic task. Boaks and colleagues demonstrated a new method for PMI estimation in showing a reduction of the collagen to non-collagen content (Co/NCo ratio) in porcine bones after a PMI of 12 months using the Sirius Red/Fast Green Collagen Staining Kit from Chondrex in 2014 (Boaks et al. Forensic Sci Int 240: 104-110, 2014). The aim of our study was to reproduce this method and to investigate if the method could be used for forensic issues. Sixteen fresh porcine bones were placed in prepared boxes where they were treated regularly with distilled water or with water from hay infusions. For determining the Co/NCo ratio, we used the Sirius Red/Fast Green Collagen Staining Kit from Chondrex, which stains collagenous (Co) proteins red and non-collagenous (NCo) proteins green Chondrex Inc. (2008). After a PMI of 1-3 months, an analysis of porcine bone thin sections was performed on the one hand with spectrophotometry, on the other hand with stereomicroscopy. Using spectrophotometry, we go low and partially negative Co/NCo ratios which were up to 100-fold lower than the results we expected to get. The data we got by stereomicroscopy and calculating the Co/NCo ratio from extracting the red and green content with the software MATLAB and so calculating the Co/NCo ratio showed a correlation between PMI and the Co/NCo ratio in the porcine bone samples. Regular addition of distilled water or water from a hay infusion did not produce any significant differences so that an increased presence of microorganisms had obviously no influence on collagen degradation.

  16. Transcoronary sinus administration of autologous bone marrow in patients with chronic refractory stable angina

    International Nuclear Information System (INIS)

    Vicario, J.; Campos, C.; Piva, J.; Faccio, F.; Gerardo, L.; Becker, C.; Ortega, H.H.; Pierini, A.; Lofeudo, C.; Novero, R.; Licheri, A.; Milesi, R.; Perez Balino, N.; Monti, A.; Amin, A.; Pfeiffer, H.; De Giovanni, E.; Fendrich, I.

    2004-01-01

    Purpose: Based on our preclinic studies with autologous unfractionated bone marrow (AUBM) via coronary sinus with transitory occlusion, a clinic study in patients with chronic stable angina was designed. The objectives were to evaluate safety, tolerance and feasibility. Methods and materials: A multicenter prospective study with inclusion and exclusion criteria defined by an Independent Clinical Committee was carried out. Fourteen patients underwent transcoronary sinus administration of freshly aspirated and filtered AUBM (60-120 ml). Safety and tolerance were evaluated. Feasibility was evaluated with Seattle Angina Questionnaire (SAQ), Canadian Cardiovascular Society (CCS) angina classification (baseline-Day 180), myocardial perfusion (baseline-Day 90) with independent core laboratory and coronary angiography (baseline and Day 30). Results: There were no changes in the safety and tolerance parameters. Preliminary clinical efficacy at Day 180 disclosed a significant improvement of 38%, evaluated by the SAQ. The CCS angina classification shows that the mean angina class was 3.0±0.55 at baseline and improved to 2.0±0.00 at Day 180 (P<.001). Semiquantitative radionuclide perfusion imaging (core lab) showed a significant improvement at Day 90 in 13/14 patients, with a mean improvement of 24% at rest (P<.01) and 33% at stress (P<.05). Coronary angiography showed more collateral vessels in 9/14 patients. Conclusions: We can conclude that AUBM via coronary sinus with transitory occlusion is tolerable and safe. Significant improvement in the myocardial perfusion at Day 90 and in the quality of life at Day 180 was observed

  17. A prospective controlled trial comparing xenograft/autogenous bone and collagen-stabilized xenograft for maxillary sinus augmentation-Complications, patient-reported outcomes and volumetric analysis.

    Science.gov (United States)

    Alayan, Jamil; Ivanovski, Saso

    2018-02-01

    Compare maxillary sinus augmentation (MSA) using two different materials-anorganic bovine bone mineral (ABBM) + autogenous bone (AB) (control group) vs. collagen-stabilized ABBM (test group) in terms of complications, patient-reported outcome measures (PROMs) and volumetric analysis. Sixty patients underwent sinus augmentation (30 control + 30 test group). Intra- and postoperative complications were recorded. PROMs measured the impact of grafting on daily activities, pain and morbidity. CT scans were used to measure graft volume, ridge height, material selection and degree of contact of graft-to-surrounding sinus walls. Dental implant placement parameters were also recorded. All complications were minor and did not prevent completion of the augmentation or subsequent implant placement. Schneiderian membrane perforation was the most frequently encountered complication. Both treatment groups reported moderate limitation in the 1st 48 hr post-surgery but little or none by day 3 or 4. Jaw opening, chewing and bruising were significantly higher in the control group. The impact on work and social life was moderate initially but reduced to little or none by the 2nd day. Mild to moderate pain and interference to daily activities were reported for the first 3 days requiring the use of NSAIDs only. A mean graft volume of 1.46 cm 3 (±0.77) was calculated in the control group and 1.27 cm 3 (±0.65) in the test group. Extent of contact between graft and surrounding sinus walls had a significant impact on bone volume. Shorter (8 mm) implants were utilized more frequently in the test group, which was also more likely to require additional vertical augmentation, but this was not statistically significant. MSA using a lateral wall approach is safe and associated with mild to moderate pain and restrictions to daily activities for 48-72 hr. Patients' reports of morbidity were greater with autogenous bone harvesting. Collagen-stabilized ABBM provides comparable bone volume to

  18. Rapidly assessing changes in bone mineral balance using natural stable calcium isotopes

    Science.gov (United States)

    Morgan, Jennifer L. L.; Skulan, Joseph L.; Gordon, Gwyneth W.; Romaniello, Stephen J.; Smith, Scott M.; Anbar, Ariel D.

    2012-01-01

    The ability to rapidly detect changes in bone mineral balance (BMB) would be of great value in the early diagnosis and evaluation of therapies for metabolic bone diseases such as osteoporosis and some cancers. However, measurements of BMB are hampered by difficulties with using biochemical markers to quantify the relative rates of bone resorption and formation and the need to wait months to years for altered BMB to produce changes in bone mineral density large enough to resolve by X-ray densitometry. We show here that, in humans, the natural abundances of Ca isotopes in urine change rapidly in response to changes in BMB. In a bed rest experiment, use of high-precision isotope ratio MS allowed the onset of bone loss to be detected in Ca isotope data after about 1 wk, long before bone mineral density has changed enough to be detectable with densitometry. The physiological basis of the relationship between Ca isotopes and BMB is sufficiently understood to allow quantitative translation of changes in Ca isotope abundances to changes in bone mineral density using a simple model. The rate of change of bone mineral density inferred from Ca isotopes is consistent with the rate observed by densitometry in long-term bed rest studies. Ca isotopic analysis provides a powerful way to monitor bone loss, potentially making it possible to diagnose metabolic bone disease and track the impact of treatments more effectively than is currently possible. PMID:22652567

  19. Plectranthus amboinicus attenuates inflammatory bone erosion in mice with collagen-induced arthritis by downregulation of RANKL-induced NFATc1 expression.

    Science.gov (United States)

    Hsu, Yu-Chieh; Cheng, Chia-Pi; Chang, Deh-Ming

    2011-09-01

    Plectranthus amboinicus has been known to treat inflammatory diseases or swelling symptoms. We investigated whether P. amboinicus exhibited an inhibitory effect on osteoclastogenesis in vitro and inflammatory bone erosion in collagen-induced arthritis (CIA) mice, an animal model of rheumatoid arthritis. We attempted to identify the active component of P. amboinicus involved in regulation of osteoclastogenesis. We treated M-CSF- and RANKL-stimulated murine bone marrow-derived macrophages (BMM) and RANKL-induced RAW264.7 cells with different concentrations of P. amboinicus or rosmarinic acid, a phytopolyphenol purified from P. amboinicus, to monitor osteoclast formation by TRAP staining. The mechanism of the inhibition was studied by biochemical analysis such as RT-PCR and immunoblotting. CIA mice were administered gavages of P. amboinicus (375 mg/kg) or placebo. Then clinical, histological, and biochemical measures were assessed to determine the effects of P. amboinicus on synovial inflammation and bone erosion by H&E staining of the inflamed joints and ELISA. Rosmarinic acid strongly inhibited RANKL-induced NF-κB activation and nuclear factor of activated T cells c1 (NFATc1) nuclear translocation in BMM, and also inhibited RANKL-induced formation of TRAP-positive multinucleated cells. A pit formation assay and the CIA animal model showed that P. amboinicus significantly inhibited the bone-resorbing activity of mature osteoclasts. We postulated that rosmarinic acid conferred the inhibitory activity on P. amboinicus for inhibition of osteoclastogenesis via downregulation of RANKL-induced NFATc1 expression. Our results indicated the possibility of P. amboinicus as a new remedy against inflammatory bone destruction.

  20. Restoration of a Critical Mandibular Bone Defect Using Human Alveolar Bone-Derived Stem Cells and Porous Nano-HA/Collagen/PLA Scaffold

    Directory of Open Access Journals (Sweden)

    Xing Wang

    2016-01-01

    Full Text Available Periodontal bone defects occur in a wide variety of clinical situations. Adult stem cell- and biomaterial-based bone tissue regeneration are a promising alternative to natural bone grafts. Recent evidence has demonstrated that two populations of adult bone marrow mesenchymal stromal cells (BMSCs can be distinguished based on their embryonic origins. These BMSCs are not interchangeable, as bones preferentially heal using cells that share the same embryonic origin. However, the feasibility of tissue engineering using human craniofacial BMSCs was unclear. The goal of this study was to explore human craniofacial BMSC-based therapy for the treatment of localized mandibular defects using a standardized, minimally invasive procedure. The BMSCs’ identity was confirmed. Scanning electron microscopy, a cell proliferation assay, and supernatant detection indicated that the nHAC/PLA provided a suitable environment for aBMSCs. Real-time PCR and electrochemiluminescence immunoassays demonstrated that osteogenic markers were upregulated by osteogenic preinduction. Moreover, in a rabbit critical-size mandibular bone defect model, total bone formation in the nHAC/PLA + aBMSCs group was significantly higher than in the nHAC/PLA group but significantly lower than in the nHAC/PLA + preinduced aBMSCs. These findings demonstrate that this engineered bone is a valid alternative for the correction of mandibular bone defects.

  1. Restoration of a Critical Mandibular Bone Defect Using Human Alveolar Bone-Derived Stem Cells and Porous Nano-HA/Collagen/PLA Scaffold

    Science.gov (United States)

    Wang, Xing; Xing, Helin; Zhang, Guilan; Wu, Xia; Zou, Xuan; Feng, Lin; Wang, Dongsheng; Li, Meng; Zhao, Jing; Du, Jianwei; Lv, Yan; E, Lingling; Liu, Hongchen

    2016-01-01

    Periodontal bone defects occur in a wide variety of clinical situations. Adult stem cell- and biomaterial-based bone tissue regeneration are a promising alternative to natural bone grafts. Recent evidence has demonstrated that two populations of adult bone marrow mesenchymal stromal cells (BMSCs) can be distinguished based on their embryonic origins. These BMSCs are not interchangeable, as bones preferentially heal using cells that share the same embryonic origin. However, the feasibility of tissue engineering using human craniofacial BMSCs was unclear. The goal of this study was to explore human craniofacial BMSC-based therapy for the treatment of localized mandibular defects using a standardized, minimally invasive procedure. The BMSCs' identity was confirmed. Scanning electron microscopy, a cell proliferation assay, and supernatant detection indicated that the nHAC/PLA provided a suitable environment for aBMSCs. Real-time PCR and electrochemiluminescence immunoassays demonstrated that osteogenic markers were upregulated by osteogenic preinduction. Moreover, in a rabbit critical-size mandibular bone defect model, total bone formation in the nHAC/PLA + aBMSCs group was significantly higher than in the nHAC/PLA group but significantly lower than in the nHAC/PLA + preinduced aBMSCs. These findings demonstrate that this engineered bone is a valid alternative for the correction of mandibular bone defects. PMID:27118977

  2. Recombinant human type II collagen hydrogel provides a xeno-free 3D micro-environment for chondrogenesis of human bone marrow-derived mesenchymal stromal cells.

    Science.gov (United States)

    Muhonen, Virpi; Narcisi, Roberto; Nystedt, Johanna; Korhonen, Matti; van Osch, Gerjo J V M; Kiviranta, Ilkka

    2017-03-01

    Recombinant human type II collagen (rhCII) hydrogel was tested as a xeno-free micro-environment for the chondrogenesis of human bone marrow-derived mesenchymal stromal cells (BM-MSCs). The rhCII hydrogels were seeded with BM-MSCs and cultured in a xeno-free chondro-inductive medium for 14, 28 and 84 days. High-density pellet cultures served as controls. The samples were subjected to biochemical, histological and gene expression analyses. Although the cells deposited glycosaminoglycans into the extracellular space significantly more slowly in the rhCII hydrogels compared to the high-density pellets, a similar potential of matrix deposition was reached by the end of the 84-day culture. At day 28 of culture, the gene expression level for cartilage marker genes (i.e. genes encoding for Sox9 transcription factor, Collagen type II and Aggrecan) were considerably lower in the rhCII hydrogels than in the high-density pellets, but at the end of the 84-day culture period, all the cartilage marker genes analysed were expressed at a similar level. Interestingly, the expression of the matrix metallopeptidases (MMP)-13, MMP-14 and MMP-8, i.e. extracellular collagen network-degrading enzymes, were transiently upregulated in the rhCII hydrogel, indicating active matrix reorganization. This study demonstrated that the rhCII hydrogel functions as a xeno-free platform for BM-MSC chondrogenesis, although the process is delayed. The reversible catabolic reaction evoked by the rhCII hydrogel might be beneficial in graft integration in vivo and pinpoints the need to further explore the use of hydrogels containing recombinant extracellular matrix (ECM) proteins to induce the chondrogenesis of MSCs. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Dating of cremated bones

    NARCIS (Netherlands)

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process.

  4. Long-term stable vertical bone regeneration after sinus floor elevation and simultaneous implant placement with and without grafting.

    Science.gov (United States)

    Verdugo, Fernando; Uribarri, Agurne; Laksmana, Theresia; D'addona, Antonio

    2017-12-01

    Less invasive surgical approaches to regenerate bone intra-sinus and allow long-term functional implant stability are needed. To evaluate long-term vertical bone regeneration after sinus floor elevation and simultaneous implant placement with and without bone grafting. Vertical bone gains (VBG) post-sinus elevation, with and without grafting, were evaluated in thirty individuals presenting an average residual bone height (RBH) of 4.2 mm using a standardized digital technique. Measurements were taken preoperatively, and at an average of 64.6 months follow-up. Clinically, peri-implant tissues were assessed for pocket formation and presence of inflammation to evaluate established success criteria. Overall, RBH averaged 4.2 ± 1.1 mm (range: 1.8-5.8) and VBG 7.7 ± 1.6 mm (range: 6.0-12.9). Mean difference of 7.6 mm between vertical bone heights (VBH) at augmented implants sites and initial RBH, 11.8 versus 4.2 mm, (P implant site. Long-term follow-ups average 64.6 months (range: 36-144) and all implants met the success criteria. VBG ≥ 7 mm were 7.3 times more likely to develop on grafted sites (OR = 7.3, P = 0.02, CI95%: 1.2-46.2). None to negligible amounts of grafting material are required to regenerate substantial amounts of autogenous bone into atrophic sinus cavities after simultaneous implant placement. The regenerated VBH seems stable for functional implant stability long-term. Implant success rates were 100% at an average of 64.6 months. © 2017 Wiley Periodicals, Inc.

  5. Estrogen enhances the bone regeneration potential of periodontal ligament stem cells derived from osteoporotic rats and seeded on nano-hydroxyapatite/collagen/poly(L-lactide).

    Science.gov (United States)

    E, Ling-Ling; Xu, Wen-Huan; Feng, Lin; Liu, Yi; Cai, Dong-Qing; Wen, Ning; Zheng, Wen-Jie

    2016-06-01

    This study investigated the effects of estrogen on the bone regeneration potential of periodontal ligament stem cells (PDLSCs) derived from osteoporotic rats and seeded on a collagen-based composite scaffold [nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA)]. For this purpose, 48 healthy 3‑month-old Sprague-Dawley female rats were divided into 2 groups as follows: the bilaterally ovariectomized (OVX) rats and sham‑operated rats. The PDLSCs were isolated at 3 months after surgery (by which time postmenopausal osteoporosis had developed). The effects of estrogen on the characteristics of these cells seeded in a culture plate and of the cells seeded on nHAC/PLA were then investigated. The PDLSC + nHAC/PLA constructs were implanted subcutaneously into the backs of severe combined immunodeficient (SCID) mice for 12 weeks in order to examine the role of estrogen in the bone formation ability of PDLSCs derived from osteoporotic rats. The results from methyl thiazolyl tetrazolium (MTT) assay revealed that the proliferation of the cells derived from the rats in the OVX group was significantly higher than that of the cells derived from the rats in the sham-operated group at the stage of logarithmic growth. The staining intensity of alkaline phosphatase (ALP) and the mineralization of the cells derived from the rats in the OVX group was significantly weaker than that of the cells from the rats in the sham-operated group. When the PDLSCs were seeded on nHAC/PLA, ALP activity, osteocalcin (OCN) secretion, mineral formation and the mRNA expression levels of ALP, OCN, estrogen receptor (ER)α and ERβ in the cells derived from the rats in the OVX group were markedly decreased. Treatment with 17β-estradiol (E2) significantly weakened the proliferative ability of the cells derived from the OVX group rats, and enhanced their osteogenic differentiation ability and the mRNA expression levels of ALP, OCN, ERα and ERβ. When the constructs were implanted

  6. Medial support by fibula bone graft in angular stable plate fixation of proximal humeral fractures: an in vitro study with synthetic bone.

    Science.gov (United States)

    Osterhoff, Georg; Baumgartner, Daniel; Favre, Philippe; Wanner, Guido A; Gerber, Hans; Simmen, Hans-Peter; Werner, Clément M L

    2011-07-01

    Failure to achieve stable fixation with medial support in proximal humeral fractures can result in varus malalignment and cut-through of the proximal screws. The purpose of this study was to investigate the influence of an intramedullary fibula bone graft on the biomechanical properties of proximal humeral fractures stabilized by angular stable plate fixation in a bone model under cyclic loading. Two fixation techniques were tested in 20 composite analog humeri models. In group F- (n = 10), fractures were fixed by an anatomically formed locking plate system. In group F+ (n = 10), the same fixation system was used with an additional fibular graft model with a length of 6 cm inserted in an intramedullary manner. Active abduction was simulated for 400 cycles by use of a recently established testing setup. Fragment gap distance was measured, and thereby, intercyclic motion, fragment migration, and residual plastic deformation were determined. The addition of a fibular graft to the fixation plate led to 5 times lower intercyclic motion, 2 times lower fragment migration, and 2 times less residual plastic deformation. Neither screw pullout, cut-through, nor implant failure was observed. Medial support with an intramedullary fibular graft in an angular stable fixation of the proximal humerus in vitro increases overall stiffness of the bone-implant construct and reduces migration of the humeral head fragment. This technique might provide a useful tool in the treatment of displaced proximal humeral fractures, especially when there is medial comminution. Copyright © 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  7. [Elastic stable intramedullary nailing (ESIN) in the treatment of both-bone forearm fractures in the child: about 87 cases].

    Science.gov (United States)

    Andaloussi, Saad; Amine Oukhouya, Mohamed; Alaoui, Othmane; Atarraf, Karima; Chater, Lamiae; Afifi, My Abderrahmane

    2017-01-01

    This study aims to describe the complications of elastic stable intramedullary nailing (ESIN) in the treatment of both-bone forearm diaphyseal fractures in the child. Between January 2009 and December 2013, 87 children with both-bone forearm diaphyseal fractures were treated by elastic stable intramedullary nailing with Métaizeau nails. 76 boys and 11 girls, with an average age of 12 years, were enrolled in the study. Nailing was promptly performed in 50 cases and after secondary displacement during plaster-cast treatment in the other cases. Both bones were nailed in all cases. All patients underwent systematic plaster immobilization for a period of about one month. On average, nails were removed after about 6 months. Functional outcomes were studied over a mean follow-up period of 10 months. Complications were marked by 14 superficial infections (14 cases), osteitis associated with material (2 cases), refracture (3 cases), pseudarthrosis (3 cases), delayed fracture consolidation (2 cases) and proximal radioulnar synostosis (1 case). Although intramedullary nailing ideally is an osteosynthesis technique suitable for the treatment of fractures in children, it is more invasive than orthopaedic treatment.Indications for treatment should remain within well-established limits.

  8. Stable Calcium Isotopes in Urine as a Biomarker of Bone Mineral Balance in Spaceflight

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary goal of this project was to demonstrate whether the relationship between bone mineral balance (BMB) and changes in the natural isotope composition of...

  9. Indirect MR-arthrography in osteochondral autograft and crushed bone graft with a collagen membrane-Correlation with histology

    Energy Technology Data Exchange (ETDEWEB)

    Streitparth, F. [Klinik fuer Strahlenheilkunde, Charite, Campus Virchow-Klinikum, Humboldt-University, Berlin (Germany)], E-mail: florian.streitparth@charite.de; Schoettle, P.; Schell, H. [Center for Musculoskeletal Surgery, Charite, Campus Virchow-Klinikum, Humboldt-University, Berlin (Germany); Lehmkuhl, L.; Madej, T.; Wieners, G. [Klinik fuer Strahlenheilkunde, Charite, Campus Virchow-Klinikum, Humboldt-University, Berlin (Germany); Duda, G.N. [Center for Musculoskeletal Surgery, Charite, Campus Virchow-Klinikum, Humboldt-University, Berlin (Germany); Schroeder, R.J. [Klinik fuer Strahlenheilkunde, Charite, Campus Virchow-Klinikum, Humboldt-University, Berlin (Germany)

    2009-04-15

    Objective: To analyze the spectrum of findings in indirect MR-arthrography following osteochondral autograft transfer system (OATS) and crushed bone graft using a magnetic resonance imaging (MRI) scoring and grading system in relation to histology as the standard of reference. Materials and methods: Iatrogenic lesions were set at ovine condylar facets (n = 6/group), treated with OATS or crushed bone graft. 1.5 T MRI was performed 6 months after surgery using PD-weighted (w fat saturated (fs) fast spin echo (FSE), T1-w 2D, and 3D fs gradient echo (GE) sequences 30 min. after i.v. Gd-DTPA administration and passive joint exercise. The repair tissue was evaluated by two independent radiologists. The MR findings were compared to histology. Results: In all cases, MRI and histologic grading correlated well and showed significant superior repair in OATS at 6 months (p < 0.05), reproducing the original articular contour and a good subchondral restoration. FsT1-w3DGE proved most appropriate identifying characteristic post-operative findings: the OATS group demonstrated bone marrow edema at the donor site and the graft/host interface showed significant enhancement in indirect MR-arthrography, indicating fibrocartilage. After crushed bone graft, we found an irregular structure and significant contrast uptake, consistent with remnants of bone grafts surrounded by inflammatory tissue. Conclusion: Indirect MR-arthrography is an accurate, non-invasive monitoring tool following OATS and crushed bone graft as the MRI scoring and grading system allows a reliable evaluation of normal and pathological osteochondral repair with a high histologic correlation.

  10. Original Article. Toxic effect of sodium fluoride on hydroxyproline level and expression of collagen-1 gene in rat bone and its amelioration by Tamrindus indica L. fruit pulp extract

    Directory of Open Access Journals (Sweden)

    Gupta Amit Raj

    2016-03-01

    Full Text Available Excessive fluoride intoxication plays an important role in the development of dental, skeletal and non-skeletal fluorosis. The aim of this study was to ascertain the toxic effect of excessive fluoride ingestion on the level of hydroxyproline and expression of type 1 collagen gene in rat bone and its amelioration by supplementation with Tamarindus indica fruit pulp extract. Forty albino rats were randomly assigned to four groups. The first group served as control and received only tap water. The second group received sodium fluoride (200 ppm through drinking water. The third group received T. indica fruit pulp extract (200 mg/kg body weight alone and the fourth group received the T. indica fruit pulp extract (200 mg/kg body weight along with fluorinated drinking water (200 ppm daily by gavage for a period of 90 days. The level of hydroxyproline and expression of type 1 collagen gene using quantitative real time PCR in the tibia bone decreased significantly with continuous exposure to sodium fluoride. Co-administration of T. indica fruit pulp extract during exposure to fluoride through drinking water restored the level of calcium, phosphorus and alkaline phosphatase in serum and the concentration of hydroxyproline in urine. It increased the level of hydroxyproline and expression of type 1 collagen gene in the tibia as compared to untreated fluoride-exposed rats. It is concluded that T. indica fruit pulp extract has an ameliorative potential to protect the bone from fluoride induced collagen damage.

  11. Oriented Collagen Scaffolds for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Shohta Kodama

    2012-03-01

    Full Text Available Oriented collagen scaffolds were developed in the form of sheet, mesh and tube by arraying flow-oriented collagen string gels and dehydrating the arrayed gels. The developed collagen scaffolds can be any practical size with any direction of orientation for tissue engineering applications. The birefringence of the collagen scaffolds was quantitatively analyzed by parallel Nicols method. Since native collagen in the human body has orientations such as bone, cartilage, tendon and cornea, and the orientation has a special role for the function of human organs, the developed various types of three-dimensional oriented collagen scaffolds are expected to be useful biomaterials for tissue engineering and regenerative medicines.

  12. The effect of SDF-1α on low dose BMP-2 mediated bone regeneration by release from heparinized mineralized collagen type I matrix scaffolds in a murine critical size bone defect model.

    Science.gov (United States)

    Zwingenberger, Stefan; Langanke, Robert; Vater, Corina; Lee, Geoffrey; Niederlohmann, Eik; Sensenschmidt, Markus; Jacobi, Angela; Bernhardt, Ricardo; Muders, Michael; Rammelt, Stefan; Knaack, Sven; Gelinsky, Michael; Günther, Klaus-Peter; Goodman, Stuart B; Stiehler, Maik

    2016-09-01

    The treatment of critical size bone defects represents a challenge. The growth factor bone morphogenetic protein 2 (BMP-2) is clinically established but has potentially adverse effects when used at high doses. The aim of this study was to evaluate if stromal derived factor-1 alpha (SDF-1α) and BMP-2 released from heparinized mineralized collagen type I matrix (MCM) scaffolds have a cumulative effect on bone regeneration. MCM scaffolds were functionalized with heparin, loaded with BMP-2 and/or SDF-1α and implanted into a murine critical size femoral bone defect (control group, low dose BMP-2 group, low dose BMP-2 + SDF-1α group, and high dose BMP-2 group). After 6 weeks, both the low dose BMP-2 + SDF-1α group (5.8 ± 0.6 mm³, p = 0.0479) and the high dose BMP-2 group (6.5 ± 0.7 mm³, p = 0.008) had a significantly increased regenerated bone volume compared to the control group (4.2 ± 0.5 mm³). There was a higher healing score in the low dose BMP-2 + SDF-1α group (median grade 8; Q1-Q3 7-9; p = 0.0357) than in the low dose BMP-2 group (7; Q1-Q3 5-9) histologically. This study showed that release of BMP-2 and SDF-1α from heparinized MCM scaffolds allows for the reduction of the applied BMP-2 concentration since SDF-1α seems to enhance the osteoinductive potential of BMP-2. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2126-2134, 2016. © 2016 Wiley Periodicals, Inc.

  13. A single injection of the anabolic bone agent, parathyroid hormone-collagen binding domain (PTH-CBD), results in sustained increases in bone mineral density for up to 12 months in normal female mice.

    Science.gov (United States)

    Ponnapakkam, Tulasi; Katikaneni, Ranjitha; Suda, Hirofumi; Miyata, Shigeru; Matsushita, Osamu; Sakon, Joshua; Gensure, Robert C

    2012-09-01

    Parathyroid hormone (PTH) is the most effective osteoporosis treatment, but it is only effective if administered by daily injections. We fused PTH(1-33) to a collagen binding domain (PTH-CBD) to extend its activity, and have shown an anabolic bone effect with monthly dosing. We tested the duration of action of this compound with different routes of administration. Normal young C57BL/6J mice received a single intraperitoneal injection of PTH-CBD (320 μg/kg). PTH-CBD treated mice showed a 22.2 % increase in bone mineral density (BMD) at 6 months and 12.8 % increase at 12 months. When administered by subcutaneous injection, PTH-CBD again caused increases in BMD, 15.2 % at 6 months and 14.3 % at 12 months. Radiolabeled PTH-CBD was concentrated in bone and skin after either route of administration. We further investigated skin effects of PTH-CBD, and histological analysis revealed an apparent increase in anagen VI hair follicles. A single dose of PTH-CBD caused sustained increases in BMD by >10 % for 1 year in normal mice, regardless of the route of administration, thus showing promise as a potential osteoporosis therapy.

  14. Collagen Homeostasis and Metabolism

    DEFF Research Database (Denmark)

    Magnusson, S Peter; Heinemeier, Katja M; Kjaer, Michael

    2016-01-01

    The musculoskeletal system and its collagen rich tissue is important for ensuring architecture of skeletal muscle, energy storage in tendon and ligaments, joint surface protection, and for ensuring the transfer of muscular forces into resulting limb movement. Structure of tendon is stable and the...

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    Host tissue response and heterotopic osteoinduction by composites of demineralized bone matrix and three different substances used as bioresorbable carriers implanted in the abdominal muscles were evaluated by strontium 85 uptake and histology 4 weeks postoperatively in 60 male Wistar rats. Both ...

  16. Healing of Large Segmental Bone Defect after Implantation of Autogenous Cancellous Bone Graft in Comparison to Hydroxyapatite and 0.5% Collagen Scaffold Combined with Mesenchymal Stem Cells

    Czech Academy of Sciences Publication Activity Database

    Nečas, A.; Proks, P.; Urbanová, L.; Srnec, R.; Stehlík, L.; Crha, M.; Raušer, P.; Plánka, L.; Janovec, J.; Dvořák, M.; Amler, Evžen; Vojtová, L.; Jančář, J.

    2010-01-01

    Roč. 79, č. 4 (2010), s. 607-612 ISSN 0001-7213 R&D Projects: GA MŠk 2B06130 Institutional support: RVO:68378041 Keywords : fracture fixation * bone healing * comminuted fracture Subject RIV: FI - Traumatology, Orthopedics Impact factor: 0.534, year: 2010

  17. Increased chemotaxis and activity of circulatory myeloid progenitor cells may contribute to enhanced osteoclastogenesis and bone loss in the C57BL/6 mouse model of collagen-induced arthritis.

    Science.gov (United States)

    Ikić Matijašević, M; Flegar, D; Kovačić, N; Katavić, V; Kelava, T; Šućur, A; Ivčević, S; Cvija, H; Lazić Mosler, E; Kalajzić, I; Marušić, A; Grčević, D

    2016-12-01

    Our study aimed to determine the functional activity of different osteoclast progenitor (OCP) subpopulations and signals important for their migration to bone lesions, causing local and systemic bone resorption during the course of collagen-induced arthritis in C57BL/6 mice. Arthritis was induced with chicken type II collagen (CII), and assessed by clinical scoring and detection of anti-CII antibodies. We observed decreased trabecular bone volume of axial and appendicular skeleton by histomorphometry and micro-computed tomography as well as decreased bone formation and increased bone resorption rate in arthritic mice in vivo. In the affected joints, bone loss was accompanied with severe osteitis and bone marrow hypercellularity, coinciding with the areas of active osteoclasts and bone erosions. Flow cytometry analysis showed increased frequency of putative OCP cells (CD3 - B220 - NK1.1 - CD11b -/lo CD117 + CD115 + for bone marrow and CD3 - B220 - NK1.1 - CD11b + CD115 + Gr-1 + for peripheral haematopoietic tissues), which exhibited enhanced differentiation potential in vitro. Moreover, the total CD11b + population was expanded in arthritic mice as well as CD11b + F4/80 + macrophage, CD11b + NK1.1 + natural killer cell and CD11b + CD11c + myeloid dendritic cell populations in both bone marrow and peripheral blood. In addition, arthritic mice had increased expression of tumour necrosis factor-α, interleukin-6, CC chemokine ligand-2 (Ccl2) and Ccl5, with increased migration and differentiation of circulatory OCPs in response to CCL2 and, particularly, CCL5 signals. Our study characterized the frequency and functional properties of OCPs under inflammatory conditions associated with arthritis, which may help to clarify crucial molecular signals provided by immune cells to mediate systemically enhanced osteoresorption. © 2016 British Society for Immunology.

  18. A multicenter randomized controlled clinical trial using a new resorbable non-cross-linked collagen membrane for guided bone regeneration at dehisced single implant sites: interim results of a bone augmentation procedure.

    Science.gov (United States)

    Wessing, Bastian; Urban, Istvan; Montero, Eduardo; Zechner, Werner; Hof, Markus; Alández Chamorro, Javier; Alández Martin, Nuria; Polizzi, Giovanni; Meloni, Silvio; Sanz, Mariano

    2017-11-01

    To compare clinical performance of a new resorbable non-cross-linked collagen membrane, creos xenoprotect (CXP), with a reference membrane (BG) for guided bone regeneration at dehisced implant sites. This randomized controlled clinical trial enrolled patients with expected dehiscence defects following implant placement to restore single teeth in the maxillary and mandibular esthetic zone and premolar area. Implants were placed using a two-stage surgical protocol with delayed loading. Bone augmentation material placed at the implant surface was immobilized with CXP or BG membrane. Soft tissue health was followed during the healing period, and the defect size was measured at reentry and 6 months after implant placement. Of the 49 included patients, 24 were treated with CXP and 25 with BG. Patient characteristics did not differ between the two arms. In the CXP arm, the defect height at implant insertion was (mean ± SD) 5.1 ± 2.1 mm (n = 24) and reduced at reentry by 81% to 1.0 ± 1.3 mm (n = 23). In the BG arm, the defect height at implant insertion was 4.9 ± 1.9 mm (n = 25) and reduced at reentry by 62% to 1.7 ± 2.1 mm (n = 24). Assuming a margin of non-inferiority of 1 mm, CXP was non-inferior to BG. Membrane exposure rate was highest at week 3 in both arms, reaching 16.7% for BG and 8.7% for CXP. The new resorbable non-cross-linked collagen membrane facilitates bone gain to support implant placement in expected dehiscence defects. The observed trend toward higher mean bone gain and lower exposure rate with CXP compared to BG should be further investigated. © 2016 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.

  19. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

    International Nuclear Information System (INIS)

    Pon-On, Weeraphat; Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I-Ming

    2014-01-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

  20. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Pon-On, Weeraphat, E-mail: fsciwpp@ku.ac.th [Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University (Thailand); Department of Physiology, Faculty of Science, Mahidol University (Thailand); Tang, I-Ming [ThEP Center, Commission of Higher Education, 328 Si Ayutthaya Rd. (Thailand); Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand)

    2014-05-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

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

    Science.gov (United States)

    Wang, Yaohui; Ural, Ani

    2018-03-11

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

  2. Bone Marrow Stromal Cells Combined With a Honeycomb Collagen Sponge Facilitate Neurite Elongation In Vitro and Neural Restoration in the Hemisected Rat Spinal Cord.

    Science.gov (United States)

    Onuma-Ukegawa, Madoka; Bhatt, Kush; Hirai, Takashi; Kaburagi, Hidetoshi; Sotome, Shinichi; Wakabayashi, Yoshiaki; Ichinose, Shizuko; Shinomiya, Kenichi; Okawa, Atsushi; Enomoto, Mitsuhiro

    2015-01-01

    In the last decade, researchers and clinicians have reported that transplantation of bone marrow stromal cells (BMSCs) promotes functional recovery after brain or spinal cord injury (SCI). However, an appropriate scaffold designed for the injured spinal cord is needed to enhance the survival of transplanted BMSCs and to promote nerve regeneration. We previously tested a honeycomb collagen sponge (HC), which when applied to the transected spinal cord allowed bridging of the gap with nerve fibers. In this study, we examined whether the HC implant combined with rat BMSCs increases nerve regeneration in vitro and enhances functional recovery in vivo. We first evaluated the neurite outgrowth of rat dorsal root ganglion (DRG) explants cultured on HC with or without BMSCs in vitro. Regeneration of neurites from the DRGs was increased by BMSCs combined with HC scaffolds. In the in vivo study, 3-mm-long HC scaffolds with or without BMSCs were implanted into the hemisected rat thoracic spinal cord. Four weeks after the procedure, rats implanted with HC scaffolds containing BMSCs displayed better motor and sensory recovery than those implanted with HC scaffolds only. Histologically, more CGRP-positive sensory fibers at the implanted site and 5-HT-positive serotonergic fibers contralateral to the implanted site were observed in spinal cords receiving BMSCs. Furthermore, more rubrospinal neurons projected distally to the HC implant containing BMSCs. Our study indicates that the application of BMSCs in a HC scaffold in the injured spinal cord directly promoted sensory nerve and rubrospinal tract regeneration, thus resulting in functional recovery.

  3. Dating of cremated bones

    OpenAIRE

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a r...

  4. Collagenous sprue

    DEFF Research Database (Denmark)

    Soendergaard, Christoffer; Riis, Lene Buhl; Nielsen, Ole Haagen

    2014-01-01

    disease and together with frequent histological findings like mucosal thinning and intraepithelial lymphocytosis the diagnosis may be hard to reach without awareness of this condition. While coeliac disease is treated using gluten restriction, collagenous sprue is, however, not improved...... by this intervention. In cases of diet-refractory 'coeliac disease' it is therefore essential to consider collagenous sprue to initiate treatment at an early stage to prevent the fibrotic progression. Here, we report a case of a 78-year-old man with collagenous sprue and present the clinical and histological...

  5. [Collagen nephritis].

    Science.gov (United States)

    Lago, N R; Bulos, M J; Monserrat, A J

    1997-01-01

    Fibrillar collagen in the glomeruli is considered specific of the nail-patella syndrome. A new nephropathy with diffuse intraglomerular deposition of type III collagen without nail and skeletal abnormalities has been described. We report the case of a 26-year-old woman who presented persistent proteinuria, hematuria, deafness without nail and skeletal abnormalities. The renal biopsy showed focal and segmental glomerulosclerosis by light microscopy. The electron microscopy revealed the presence of massive fibrillar collagen within the mesangial matriz and the basement membrane. This is the first patient reported in our country. We emphasize the usefulness of electron microscopy in the study of glomerular diseases.

  6. Collagen fibril surface displays a constellation of sites capable of promoting fibril assembly, stability, and hemostasis

    Energy Technology Data Exchange (ETDEWEB)

    Orgel, J.P.; Antipova, O.; Sagi, I.; Bitler, A.; Qiu, D.; Wang, R.; Xu, Y.; San Antonio, J.D. (IIT)

    2011-12-14

    Fibrillar collagens form the structural basis of organs and tissues including the vasculature, bone, and tendon. They are also dynamic, organizational scaffolds that present binding and recognition sites for ligands, cells, and platelets. We interpret recently published X-ray diffraction findings and use atomic force microscopy data to illustrate the significance of new insights into the functional organization of the collagen fibril. These data indicate that collagen's most crucial functional domains localize primarily to the overlap region, comprising a constellation of sites we call the 'master control region.' Moreover, the collagen's most exposed aspect contains its most stable part - the C-terminal region that controls collagen assembly, cross-linking, and blood clotting. Hidden beneath the fibril surface exists a constellation of 'cryptic' sequences poised to promote hemostasis and cell - collagen interactions in tissue injury and regeneration. These findings begin to address several important, and previously unresolved, questions: How functional domains are organized in the fibril, which domains are accessible, and which require proteolysis or structural trauma to become exposed? Here we speculate as to how collagen fibrillar organization impacts molecular processes relating to tissue growth, development, and repair.

  7. Clinical outcome of periodontal regenerative therapy using collagen membrane and deproteinized bovine bone mineral: a 2.5-year follow-up study.

    Science.gov (United States)

    Irokawa, Daisuke; Takeuchi, Takahiro; Noda, Katsuya; Goto, Hiroaki; Egawa, Masahiro; Tomita, Sachiyo; Sugito, Hiroki; Nikaido, Masahiko; Saito, Atsushi

    2017-02-17

    This study aimed to evaluate, longitudinally, the outcome of periodontal regenerative therapy using a deproteinized bovine bone mineral (DBBM) in combination with a collagen barrier (CB) for the treatment of intrabony defects. Patients with chronic periodontitis who have completed initial periodontal therapy participated in this study. They had at least one 2- or 3-wall intrabony periodontal defect of ≥3 mm in depth. During surgery, defects were filled with DBBM and covered with CB. Ten patients completed 2.5-year reevaluation. At baseline, mean clinical attachment level (CAL) of the treated site was 8.0 mm and mean probing depth (PD) was 7.5 mm. Mean depth of intrabony component was 4.6 mm. Mean gains in CAL at 6 months and 2.5 years were 2.8 ± 1.0 and 1.4 ± 1.5 mm, respectively, both showing a significant improvement from baseline. CAL gains at 1 and 2.5 years were significantly reduced from that at 6 months. A significant improvement in PD was also noted: mean reductions in PD at 6 months and 2.5 years were 4.0 ± 0.8 and 3.2 ± 0.8 mm, respectively. The combination therapy using DBBM and CB yielded statistically significant effects such as CAL gain and PD reduction, up to 2.5 years in the treatment of intrabony defects. However, the trend for decrease in CAL gain over time calls for the need for careful maintenance care.

  8. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)-bioglass/chitosan-collagen composite scaffolds: a bone tissue engineering applications.

    Science.gov (United States)

    Pon-On, Weeraphat; Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I-Ming

    2014-05-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze-thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Biomimetic properties of an injectable chitosan/nano-hydroxyapatite/collagen composite

    International Nuclear Information System (INIS)

    Huang Zhi; Feng Qingling; Yu Bo; Li Songjian

    2011-01-01

    To meet the challenges of designing an injectable scaffold and regenerating bone with complex three-dimensional (3D) structures, a biomimetic and injectable hydrogel scaffold based on nano-hydroxyapatite (HA), collagen (Col) and chitosan (Chi) is synthesized. The chitosan/nano-hydroxyapatite/collagen (Chi/HA/Col) solution rapidly forms a stable gel at body temperature. It shows some features of natural bone both in main composition and microstructure. The Chi/HA/Col system can be expected as a candidate for workable systemic minimally invasive scaffolds with surface properties similar to physiological bone based on scanning electron microscopic (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) results.

  10. Using Natural Stable Calcium Isotopes to Rapidly Assess Changes in Bone Mineral Balance Using a Bed Rest Model to Induce Bone Loss

    Science.gov (United States)

    Morgan, J. L. L.; Skulan, J. L.; Gordon, G. E.; Smith, Scott M.; Romaniello, S. J.; Anbar, A. D.

    2012-01-01

    Metabolic bone diseases like osteoporosis result from the disruption of normal bone mineral balance (BMB) resulting in bone loss. During spaceflight astronauts lose substantial bone. Bed rest provides an analog to simulate some of the effects of spaceflight; including bone and calcium loss and provides the opportunity to evaluate new methods to monitor BMB in healthy individuals undergoing environmentally induced-bone loss. Previous research showed that natural variations in the Ca isotope ratio occur because bone formation depletes soft tissue of light Ca isotopes while bone resorption releases that isotopically light Ca back into soft tissue (Skulan et al, 2007). Using a bed rest model, we demonstrate that the Ca isotope ratio of urine shifts in a direction consistent with bone loss after just 7 days of bed rest, long before detectable changes in bone mineral density (BMD) occur. The Ca isotope variations tracks changes observed in urinary N-teleopeptide, a bone resorption biomarker. Bone specific alkaline phosphatase, a bone formation biomarker, is unchanged. The established relationship between Ca isotopes and BMB can be used to quantitatively translate the changes in the Ca isotope ratio to changes in BMD using a simple mathematical model. This model predicts that subjects lost 0.25 0.07% ( SD) of their bone mass from day 7 to day 30 of bed rest. Given the rapid signal observed using Ca isotope measurements and the potential to quantitatively assess bone loss; this technique is well suited to study the short-term dynamics of bone metabolism.

  11. Guided bone regeneration in standardized calvarial defects using beta-tricalcium phosphate and collagen membrane: a real-time in vivo micro-computed tomographic experiment in rats.

    Science.gov (United States)

    Ramalingam, Sundar; Al-Rasheed, Abdulaziz; ArRejaie, Aws; Nooh, Nasser; Al-Kindi, Mohammed; Al-Hezaimi, Khalid

    2016-05-01

    Guided bone regeneration (GBR) procedures using graft materials have been used for reconstruction of osseous defects. The aim of the present in vivo micro-computed tomographic (µCT) and histologic study was to assess in real time the bone regeneration at GBR sites in standardized experimental calvarial defects (diameter 3.3 mm) using β-tricalcium phosphate (β-TCP) with and without collagen membrane (CM). A single full-thickness calvarial defect was created on the left parietal bone in young female Wistar albino rats (n = 30) weighing approximately 300 g and aged about 6 weeks. The animals were randomly divided into three groups for treatment, based on calvarial defect filling material: (1) control group (n = 10); (2) β-TCP + CM group (n = 10); (3) β-TCP group (n = 10). Real-time in vivo µCT analyses were performed immediately after surgery and at 2, 4, 6 and 10 weeks to determine the volume and mineral density of the newly formed bone (BVNFB, MDNFB) and remaining β-TCP particles (VRBP, MDRBP). The animals were killed at 10 weeks and calvarial specimens were evaluated histologically. In the control group, MDNFB increased significantly at 6 weeks (0.32 ± 0.002 g/mm(3), P < 0.01) compared to that at baseline. In β-TCP + CM group, BVNFB (1.10 ± 0.12 mm(3), P < 0.01) and MDNFB (0.13 ± 0.02 g/mm(3), P < 0.01) significantly increased at the 4th week than baseline. In the β-TCP group, BVNFB (1.13 ± 0.12 mm(3), P < 0.01) and MDNFB (0.14 ± 0.01 g/mm(3), P < 0.01) significantly increased at 6 weeks compared to that at baseline. Significant reduction in VRBP was neither seen in the β-TCP + CM group nor in the β-TCP group. While in the β-TCP + CM group MDRBP was reduced significantly at 6 weeks (0.44 ± 0.9 g/mm(3), P < 0.01) from baseline (0.98 ± 0.03 g/mm(3)), similar significant reduction in MDRBP from baseline (0.92 ± 0.07 g/mm(3)) was seen only at 10 weeks (0.45 ± 0.06 g/mm(3), P < 0.05) in the β-TCP group. Histologic findings at 10 weeks revealed

  12. Stable isotope discrimination factors and between-tissue isotope comparisons for bone and skin from captive and wild green sea turtles (Chelonia mydas).

    Science.gov (United States)

    Turner Tomaszewicz, Calandra N; Seminoff, Jeffrey A; Price, Mike; Kurle, Carolyn M

    2017-11-30

    The ecological application of stable isotope analysis (SIA) relies on taxa- and tissue-specific stable carbon (Δ 13 C) and nitrogen (Δ 15 N) isotope discrimination factors, determined with captive animals reared on known diets for sufficient time to reflect dietary isotope ratios. However, captive studies often prohibit lethal sampling, are difficult with endangered species, and reflect conditions not experienced in the wild. We overcame these constraints and determined the Δ 13 C and Δ 15 N values for skin and cortical bone from green sea turtles (Chelonia mydas) that died in captivity and evaluated the utility of a mathematical approach to predict discrimination factors. Using stable carbon (δ 13 C values) and nitrogen (δ 15 N values) isotope ratios from captive and wild turtles, we established relationships between bone stable isotope (SI) ratios and those from skin, a non-lethally sampled tissue, to facilitate comparisons of SI ratios among studies using multiple tissues. The mean (±SD) Δ 13 C and Δ 15 N values (‰) between skin and bone from captive turtles and their diet (non-lipid-extracted) were 2.3 ± 0.3 and 4.1 ± 0.4 and 2.1 ± 0.6 and 5.1 ± 1.1, respectively. The mathematically predicted Δ 13 C and Δ 15 N values were similar (to within 1‰) to the experimentally derived values. The mean δ 15 N values from bone were higher than those from skin for captive (+1.0 ± 0.9‰) and wild (+0.8 ± 1.0‰) turtles; the mean δ 13 C values from bone were lower than those from skin for wild turtles (-0.6 ± 0.9‰), but the same as for captive turtles. We used linear regression equations to describe bone vs skin relationships and create bone-to-skin isotope conversion equations. For sea turtles, we provide the first (a) bone-diet SI discrimination factors, (b) comparison of SI ratios from individual-specific bone and skin, and (c) evaluation of the application of a mathematical approach to predict stable isotope discrimination factors. Our approach

  13. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  14. Collagenous gastritis.

    Science.gov (United States)

    Jin, Xiaoyi; Koike, Tomoyuki; Chiba, Takashi; Kondo, Yutaka; Ara, Nobuyuki; Uno, Kaname; Asano, Naoki; Iijima, Katsunori; Imatani, Akira; Watanabe, Mika; Shirane, Akio; Shimosegawa, Tooru

    2013-09-01

    In the present paper, we report a case of rare collagenous gastritis. The patient was a 25-year-old man who had experienced nausea, abdominal distention and epigastralgia since 2005. Esophagogastroduodenoscopy (EGD) carried out at initial examination by the patient's local doctor revealed an extensively discolored depression from the upper gastric body to the lower gastric body, mainly including the greater curvature, accompanied by residual mucosa with multiple islands and nodularity with a cobblestone appearance. Initial biopsies sampled from the nodules and accompanying atrophic mucosa were diagnosed as chronic gastritis. In August, 2011, the patient was referred to Tohoku University Hospital for observation and treatment. EGD at our hospital showed the same findings as those by the patient's local doctor. Pathological findings included a membranous collagen band in the superficial layer area of the gastric mucosa, which led to a diagnosis of collagenous gastritis. Collagenous gastritis is an extremely rare disease, but it is important to recognize its characteristic endoscopic findings to make a diagnosis. © 2012 The Authors. Digestive Endoscopy © 2012 Japan Gastroenterological Endoscopy Society.

  15. [The gene expression of some cytokines and collagen proteins in rat bone tissue is related to estradiol (E2) and age].

    Science.gov (United States)

    Huang, H N; Tu, Z C; Liao, S; Zhao, S Y; Li, C B; Huang, S Z; Tang, T T; Dai, K R

    1999-12-01

    30 female SD rats (3 months old) are equally divided into three groups: ovariectomy (OVX) rats, sham-operated (SHO) rats and 17 beta estradiol (E2) treated OVX rats. For each group, mRNA was isolated from long bone at one month and three months after surgery, respectively. mRNA was reverse transcribed into single strand cDNA and then used as a probe hybridizing to the DNA fragments of col I alpha(1), col I alpha(2), col III, col V, fibronectin, IL-1, IL-6, TGF-beta, LIF, TNF-alpha, TNF-beta by reverse northern and dot blot hybrization. The housekeeping gene, gapdh, was used as an internal control. The results show that in bone of rat, the stable expression of col I alpha (1), col I alpha(2) and col III are related to age not ovariectomy, while supplement with E2 can inhibit the expression of col III and col I alpha(2) completely. The expression of col V, IL-1, IL-6 can be inhibited by estrogen and recovered by removal of estrogen by OVX, then addition of E2 decreased it to the normal level. The expression of TGF-beta is also inhibited by estrogen. It increased during one month after overiectomy, and partially decreased in E2 complemented rat. Three months after surgery, the level of increasing and decreasing is less evident as two months ago. It seems that in young SD rat, the expression of TGF-beta is related to both estrogen and age.

  16. The combined use of rhBMP-2/ACS, autogenous bone graft, a bovine bone mineral biomaterial, platelet-rich plasma, and guided bone regeneration at nonsubmerged implant placement for supracrestal bone augmentation. A case report.

    Science.gov (United States)

    Sclar, Anthony G; Best, Steven P

    2013-01-01

    This case report presents the clinical application and outcomes of the use of a combined approach to treat a patient with a severe alveolar defect. Recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier, along with autogenous bone graft, bovine bone mineral, platelet-rich plasma, and guided bone regeneration, were used simultaneous with nonsubmerged implant placement. At 1 year postsurgery, healthy peri-implant soft tissues and radiographically stable peri-implant crestal bone levels were observed along with locally increased radiographic bone density. In addition, a cone beam computed tomography (CBCT) scan demonstrated apparent supracrestal peri-implant bone augmentation with the appearance of normal alveolar ridge contours, including the facial bone wall.

  17. Clinical evaluation of porous hydroxyapatite bone graft (Periobone G with and without collagen membrane (Periocol in the treatment of bilateral grade II furcation defects in mandibular first permanent molars

    Directory of Open Access Journals (Sweden)

    Sruthy Prathap

    2013-01-01

    Full Text Available Background: Furcation invasions represent one of the most demanding therapeutic challenges in periodontics. This investigation assessed and compared the clinical efficacy of hydroxyapatite bone graft material when used alone and with collagen membrane in the treatment of grade II furcation defects. Materials and Methods: Ten patients with comparable bilateral furcation defects in relation to mandibular first molars were selected and treated in a split-mouth design. After the hygiene phase of therapy was completed, the groups were selected randomly either for treatment with hydroxyapatite bone graft (Periobone G alone or with a combination of bone graft and guided tissue regeneration (GTR membrane (Periocol. Clinical parameters like plaque index, gingival index, vertical probing depth, horizontal probing depth, clinical attachment level, position of marginal gingiva, and the amount of bone fill were used at baseline and at 3 and 6 months postoperatively. Results: At 6 months, both surgical procedures resulted in statistically significant reduction in vertical and horizontal probing depths and gain in the clinical attachment level. Conclusion: The use of combination technique yielded superior results compared to sites treated with bone graft alone. However, the difference was not statistically significant.

  18. Enhanced physicochemical properties of collagen by using EDC ...

    Indian Academy of Sciences (India)

    The necessity of bone substitutes for wound healing has promoted development of the biomimetic bone ... of collagen which facilitates wound-healing processes are stimulation of cell migration and infiltration and .... On the other hand, in the process of crosslinking, carboxyl and amino groups that exist within collagen would ...

  19. Understanding the Structure of Bones

    Science.gov (United States)

    ... structure of bone is very similar to reinforced concrete that is used to make a building or ... a defective blueprint is produced that tells the cell to produce deformed collagen, resulting in bad collagen ...

  20. Microwave sintering and in vitro study of defect-free stable porous multilayered HAp-ZrO2 artificial bone scaffold

    Science.gov (United States)

    Jang, Dong-Woo; Nguyen, Thi-Hiep; Sarkar, Swapan Kumar; Lee, Byong-Taek

    2012-06-01

    Continuously porous hydroxyapatite (HAp)/t-ZrO2 composites containing concentric laminated frames and microchanneled bodies were fabricated by an extrusion process. To investigate the mechanical properties of HAp/t-ZrO2 composites, the porous composites were sintered at different temperatures using a microwave furnace. The microstructure was designed to imitate that of natural bone, particularly small bone, with both cortical and spongy bone sections. Each microchannel was separated by alternating lamina of HAp, HAp-(t-ZrO2) and t-ZrO2. HAp and ZrO2 phases existed on the surface of the microchannel and the core zone to increase the biocompatibility and mechanical properties of the HAp-ZrO2 artificial bone. The sintering behavior was evaluated and the optimum sintering temperature was found to be 1400 °C, which produced a stable scaffold. The material characteristics, such as the microstructure, crystal structure and compressive strength, were evaluated in detail for different sintering temperatures. A detailed in vitro study was carried out using MTT assay, western blot analysis, gene expression by polymerase chain reaction and laser confocal image analysis of cell proliferation. The results confirmed that HAp-ZrO2 performs as an artificial bone, showing excellent cell growth, attachment and proliferation behavior using osteoblast-like MG63 cells.

  1. Microwave sintering and in vitro study of defect-free stable porous multilayered HAp–ZrO2 artificial bone scaffold

    Directory of Open Access Journals (Sweden)

    Dong-Woo Jang, Thi-Hiep Nguyen, Swapan Kumar Sarkar and Byong-Taek Lee

    2012-01-01

    Full Text Available Continuously porous hydroxyapatite (HAp/t-ZrO2 composites containing concentric laminated frames and microchanneled bodies were fabricated by an extrusion process. To investigate the mechanical properties of HAp/t-ZrO2 composites, the porous composites were sintered at different temperatures using a microwave furnace. The microstructure was designed to imitate that of natural bone, particularly small bone, with both cortical and spongy bone sections. Each microchannel was separated by alternating lamina of HAp, HAp–(t-ZrO2 and t-ZrO2. HAp and ZrO2 phases existed on the surface of the microchannel and the core zone to increase the biocompatibility and mechanical properties of the HAp-ZrO2 artificial bone. The sintering behavior was evaluated and the optimum sintering temperature was found to be 1400 °C, which produced a stable scaffold. The material characteristics, such as the microstructure, crystal structure and compressive strength, were evaluated in detail for different sintering temperatures. A detailed in vitro study was carried out using MTT assay, western blot analysis, gene expression by polymerase chain reaction and laser confocal image analysis of cell proliferation. The results confirmed that HAp-ZrO2 performs as an artificial bone, showing excellent cell growth, attachment and proliferation behavior using osteoblast-like MG63 cells.

  2. Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo micro-computed tomographic and histologic experiment in rats

    Science.gov (United States)

    Al-Hezaimi, Khalid; Ramalingam, Sundar; Al-Askar, Mansour; ArRejaie, Aws S; Nooh, Nasser; Jawad, Fawad; Aldahmash, Abdullah; Atteya, Muhammad; Wang, Cun-Yu

    2016-01-01

    The aim of the present real time in vivo micro-computed tomography (µCT) and histologic experiment was to assess the efficacy of guided bone regeneration (GBR) around standardized calvarial critical size defects (CSD) using bone marrow-derived mesenchymal stem cells (BMSCs), and collagen membrane (CM) with and without tricalcium phosphate (TCP) graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD (diameter 4.6 mm) were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. All defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone (NFB) and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo µCT. At the 10th week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness of NFB was similar to that of the native bone in groups 1 and 2 as compared to the NFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical “lock” between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adjunct BMSC therapy. PMID:27025260

  3. Effect of Allogeneic Bone Marrow-mesenchymal Stem Cells (BM-MSCs) to Accelerate Burn Healing of Rat on the Expression of Collagen Type I and Integrin α2β1.

    Science.gov (United States)

    Revilla, Gusti; Darwin, Eryati; Yanwirasti; Rantam, Fedik A

    Burn is a public health problem, it causes physical disability even death. Treatment of burn wound has been conducted in various ways, but the satisfactory healing has not been provided. Bone marrow-derived mesenchymal stem cells (BM-MSCs) treatment is one of attempt to burn recovery, accelerate wound healing and angiogenesis. This study aimed to investigate the effect of allogeneic BM-MSC treatment on the expression of collagen type I and integrin α2β1 in burn skin tissue of rat observed on day 14. Twelve Wistar rats divided into two groups, control group (injected with phospate buffer solution) and treatment group (injected with BM-MSC). Rat was anaesthetized with xylazine and ketamine (ratio 1:1), fur of rat's back was shaved and full thickness burn was made by boiling plate in hot water for 30 min and patched on the back for 20 min. The burns were covered by tegaderm film and elastomult haft. Antalgin as an analgetic was injected to rats during observation process. Burns of rat was observed on day 14. In this study one-way analysis of variance test and Tukey as a further test were analyzed. The results showed that the healing time of allogeneic BM-MSC treatment on burn skin tissue rats was faster, the thickness of collagen type I in burn skin tissue of rats was thicker (0.977 μm) than controls (0.475 μm) and statistically demonstrated significant differences (p = 0.000). The average percentage of integrin α2β1 expression was higher (2.94%) than control group (2.34%), but the differences were not statistically significant (p = 0.176). The study concluded that BM-MSC treatment was able to accelerate the healing process of burns by increasing the thickness of the collagen and the percentage of integrin α2β1, thus accelerated the cell migration involved during wound healing.

  4. Chitosan: collagen sponges. In vitro mineralization

    International Nuclear Information System (INIS)

    Martins, Virginia da C.A.; Silva, Gustavo M.; Plepis, Ana Maria G.

    2011-01-01

    The regeneration of bone tissue is a problem that affects many people and scaffolds for bone tissue growth has been widely studied. The aim of this study was the in vitro mineralization of chitosan, chitosan:native collagen and chitosan:anionic collagen sponges. The sponges were obtained by lyophilization and mineralization was made by soaking the sponges in alternating solutions containing Ca 2+ and PO 4 3- . The mineralization was confirmed by infrared spectroscopy, energy dispersive X-ray and X-ray diffraction observing the formation of phosphate salts, possibly a carbonated hydroxyapatite since Ca/P=1.80. The degree of mineralization was obtained by thermogravimetry calculating the amount of residue at 750 deg C. The chitosan:anionic collagen sponge showed the highest degree of mineralization probably due to the fact that anionic collagen provides additional sites for interaction with the inorganic phase. (author)

  5. Autotransplantation of mesenchymal stromal cells from bone-marrow to heart in patients with severe stable coronary artery disease and refractory angina — Final 3-year follow-up

    DEFF Research Database (Denmark)

    Mathiasen, Anders Bruun; Haack-Sørensen, Mandana; Jørgensen, Erik

    2013-01-01

    The study assessed long-term safety and efficacy of intramyocardial injection of autologous bone-marrow derived mesenchymal stromal cells (BMMSCs) in patients with severe stable coronary artery disease (CAD) and refractory angina.......The study assessed long-term safety and efficacy of intramyocardial injection of autologous bone-marrow derived mesenchymal stromal cells (BMMSCs) in patients with severe stable coronary artery disease (CAD) and refractory angina....

  6. Monte Carlo simulation of an anthropometric phantom used for calibrating in vivo K-XRF spectroscopy measurements of stable lead in bone.

    Science.gov (United States)

    Lodwick, Camille J; Spitz, Henry B

    2008-12-01

    An anthropometric surrogate (phantom) of the human leg was defined in the constructs of the Monte Carlo N Particle (MCNP) code to predict the response when used in calibrating K x-ray fluorescence (K-XRF) spectrometry measurements of stable lead in bone. The predicted response compared favorably with measurements using the anthropometric phantom containing a tibia with increasing stable lead content. These benchmark measurements confirmed the validity of a modified MCNP code to accurately simulate K-XRF spectrometry measurements of stable lead in bone. A second, cylindrical leg phantom was simulated to determine whether the shape of the calibration phantom is a significant factor in evaluating K-XRF performance. Simulations of the cylindrical and anthropometric calibration phantoms suggest that a cylindrical calibration standard overestimates lead content of a human leg up to 4%. A two-way analysis of variance determined that phantom shape is a statistically significant factor in predicting the K-XRF response. These results suggest that an anthropometric phantom provides a more accurate calibration standard compared to the conventional cylindrical shape, and that a cylindrical shape introduces a 4% positive bias in measured lead values.

  7. Treatment of long bone osteomyelitis with a mechanically stable intramedullar antibiotic dispenser: nineteen consecutive cases with a minimum of 12 months follow-up.

    Science.gov (United States)

    Sancineto, Carlos Federico; Barla, Jorge Daniel

    2008-12-01

    Antibiotic cement beads are the most common system of local antibiotic delivery. Unfortunately, bead strings do not give mechanical support to the fracture site, stability being fundamental in osteomyelitis treatment. Local treatment associated with bone stability should improve the results in posttraumatic osteomyelitis. The objective of this article is to present our experience in the treatment of long bone osteomyelitis using an intramedullary, mechanically stable antibiotic dispenser. We present a retrospective review of a consecutive series of patients with a long bone osteomyelitis treated using an intramedullary, mechanically stable antibiotic dispenser. The dispenser used with a T-95 chest tube filled with poly(methyl methacrylate) + antibiotic (vancomycin, gentamycin, or both, tobramycin or imipenem; depending on culture results) and with a metal center (Ender nail). Fifteen patients were men and three were women, with an average age of 37 years (range, 18-52 years). In four cases, treatment involved the femur and in 15 the tibia. Positive cultures were obtained from each patient. Methicillin-resistant Staphylococcus aureus was isolated in 17 cases. The intramedullary dispenser was removed between 6 and 76 weeks after surgery. Success was defined as negative cultures after dispenser removal. Follow-up period was between 10 and 54 months. Negative cultures were obtained from intramedullary reaming after dispenser removal in all but one patient who could not finish treatment because of local intolerance to antibiotic treatment. None of the 17 patients presented an infection recurrence. The combination of local antibiotic treatment with bone segment stability showed acceptable results in our short series of patients. Further investigation on locked intramedullary antibiotic dispensers providing improved stability will help us learn about this difficult clinical scenario.

  8. Carbon-centered radicals in γ-irradiated bone substituting biomaterials based on hydroxyapatite.

    Science.gov (United States)

    Sadlo, Jaroslaw; Strzelczak, Grazyna; Lewandowska-Szumiel, Malgorzata; Sterniczuk, Marcin; Pajchel, Lukasz; Michalik, Jacek

    2012-09-01

    Gamma irradiated synthetic hydroxyapatite, bone substituting materials NanoBone(®) and HA Biocer were examined using EPR spectroscopy and compared with powdered human compact bone. In every case, radiation-induced carbon centered radicals were recorded, but their molecular structures and concentrations differed. In compact bone and synthetic hydroxyapatite the main signal assigned to the CO(2) (-) anion radical was stable, whereas the signal due to the CO(3) (3-) radical dominated in NanoBone(®) and HA Biocer just after irradiation. However, after a few days of storage of these samples, also a CO(2) (-) signal was recorded. The EPR study of irradiated compact bone and the synthetic graft materials suggest that their microscopic structures are different. In FT-IR spectra of NanoBone(®), HA Biocer and synthetic hydroxyapatite the HPO(4) (2-) and CO(3) (2-) in B-site groups are detected, whereas in compact bone signals due to collagen dominate.

  9. Live Imaging of Type I Collagen Assembly Dynamics in Osteoblasts Stably Expressing GFP and mCherry-Tagged Collagen Constructs.

    Science.gov (United States)

    Lu, Yongbo; Kamel-El Sayed, Suzan A; Wang, Kun; Tiede-Lewis, LeAnn M; Grillo, Michael A; Veno, Patricia A; Dusevich, Vladimir; Phillips, Charlotte L; Bonewald, Lynda F; Dallas, Sarah L

    2018-02-20

    Type I collagen is the most abundant extracellular matrix protein in bone and other connective tissues and plays key roles in normal and pathological bone formation as well as in connective tissue disorders and fibrosis. Although much is known about the collagen biosynthetic pathway and its regulatory steps, the mechanisms by which it is assembled extracellularly are less clear. We have generated GFPtpz and mCherry-tagged collagen fusion constructs for live imaging of type I collagen assembly by replacing the α2(I)-procollagen N-terminal propeptide with GFPtpz or mCherry. These novel imaging probes were stably transfected into MLO-A5 osteoblast-like cells and fibronectin-null mouse embryonic fibroblasts (FN-null-MEFs) and used for imaging type I collagen assembly dynamics and its dependence on fibronectin. Both fusion proteins co-precipitated with α1(I)-collagen and remained intracellular without ascorbate but were assembled into α1(I) collagen-containing extracellular fibrils in the presence of ascorbate. Immunogold-EM confirmed their ultrastuctural localization in banded collagen fibrils. Live cell imaging in stably transfected MLO-A5 cells revealed the highly dynamic nature of collagen assembly and showed that during assembly the fibril networks are continually stretched and contracted due to the underlying cell motion. We also observed that cell-generated forces can physically reshape the collagen fibrils. Using co-cultures of mCherry- and GFPtpz-collagen expressing cells, we show that multiple cells contribute collagen to form collagen fiber bundles. Immuno-EM further showed that individual collagen fibrils can receive contributions of collagen from more than one cell. Live cell imaging in FN-null-MEFs expressing GFPtpz-collagen showed that collagen assembly was both dependent upon and dynamically integrated with fibronectin assembly. These GFP-collagen fusion constructs provide a powerful tool for imaging collagen in living cells and have revealed novel

  10. Periodontal regeneration with stem cells-seeded collagen-hydroxyapatite scaffold.

    Science.gov (United States)

    Liu, Zeping; Yin, Xing; Ye, Qingsong; He, Wulin; Ge, Mengke; Zhou, Xiaofu; Hu, Jing; Zou, Shujuan

    2016-07-01

    Re-establishing compromised periodontium to its original structure, properties and function is demanding, but also challenging, for successful orthodontic treatment. In this study, the periodontal regeneration capability of collagen-hydroxyapatite scaffolds, seeded with bone marrow stem cells, was investigated in a canine labial alveolar bone defect model. Bone marrow stem cells were isolated, expanded and characterized. Porous collagen-hydroxyapatite scaffold and cross-linked collagen-hydroxyapatite scaffold were prepared. Attachment, migration, proliferation and morphology of bone marrow stem cells, co-cultured with porous collagen-hydroxyapatite or cross-linked collagen-hydroxyapatite, were evaluated in vitro. The periodontal regeneration capability of collagen-hydroxyapatite scaffold with or without bone marrow stem cells was tested in six beagle dogs, with each dog carrying one sham-operated site as healthy control, and three labial alveolar bone defects untreated to allow natural healing, treated with bone marrow stem cells - collagen-hydroxyapatite scaffold implant or collagen-hydroxyapatite scaffold implant, respectively. Animals were euthanized at 3 and 6 months (3 animals per group) after implantation and the resected maxillary and mandibular segments were examined using micro-computed tomography scan, H&E staining, Masson's staining and histometric evaluation. Bone marrow stem cells were successfully isolated and demonstrated self-renewal and multi-potency in vitro. The porous collagen-hydroxyapatite and cross-linked collagen-hydroxyapatite had average pore sizes of 415 ± 20 µm and 203 ± 18 µm and porosity of 69 ± 0.5% and 50 ± 0.2%, respectively. The attachment, proliferation and migration of bone marrow stem cells were satisfactory on both porous collagen-hydroxyapatite and cross-linked collagen-hydroxyapatite scaffolds. Implantation of bone marrow stem cells - collagen-hydroxyapatite or collagen-hydroxyapatite scaffold in

  11. Regulation of COL1A1 expression in type I collagen producing tissues: identification of a 49 base pair region which is required for transgene expression in bone of transgenic mice

    Science.gov (United States)

    Bedalov, A.; Salvatori, R.; Dodig, M.; Kronenberg, M. S.; Kapural, B.; Bogdanovic, Z.; Kream, B. E.; Woody, C. O.; Clark, S. H.; Mack, K.; hide

    1995-01-01

    Previous deletion studies using a series of COL1A1-CAT fusion genes have indicated that the 625 bp region of the COL1A1 upstream promoter between -2295 and -1670 bp is required for high levels of expression in bone, tendon, and skin of transgenic mice. To further define the important sequences within this region, a new series of deletion constructs extending to -1997, -1794, -1763, and -1719 bp has been analyzed in transgenic mice. Transgene activity, determined by measuring CAT activity in tissue extracts of 6- to 8-day-old transgenic mouse calvariae, remains high for all the new deletion constructs and drops to undetectable levels in calvariae containing the -1670 bp construct. These results indicate that the 49 bp region of the COL1A1 promoter between -1719 and -1670 bp is required for high COL1A1 expression in bone. Although deletion of the same region caused a substantial reduction of promoter activity in tail tendon, the construct extending to -1670 bp is still expressed in this tissue. However, further deletion of the promoter to -944 bp abolished activity in tendon. Gel mobility shift studies identified a protein in calvarial nuclear extracts that is not found in tendon nuclear extracts, which binds within this 49 bp region. Our study has delineated sequences in the COL1A1 promoter required for expression of the COL1A1 gene in high type I collagen-producing tissues, and suggests that different cis elements control expression of the COL1A1 gene in bone and tendon.

  12. The Collagen Family

    Science.gov (United States)

    Ricard-Blum, Sylvie

    2011-01-01

    Collagens are the most abundant proteins in mammals. The collagen family comprises 28 members that contain at least one triple-helical domain. Collagens are deposited in the extracellular matrix where most of them form supramolecular assemblies. Four collagens are type II membrane proteins that also exist in a soluble form released from the cell surface by shedding. Collagens play structural roles and contribute to mechanical properties, organization, and shape of tissues. They interact with cells via several receptor families and regulate their proliferation, migration, and differentiation. Some collagens have a restricted tissue distribution and hence specific biological functions. PMID:21421911

  13. The collagen microfibril model, a tool for biomaterials scientists

    Science.gov (United States)

    Animal hides, a major byproduct of the meat industry, are a rich source of collagen, a structural protein of the extracellular matrix that gives strength and form to the skin, tendons and bones of mammals. The structure of fibrous collagen, a long triple helix that self-associates in a staggered arr...

  14. Collagen a natural scaffold for biology and engineering

    Science.gov (United States)

    Collagen, the most abundant protein in mammals, constitutes a quarter of the animal's total weight. The unique structure of fibrous collagens, a long triple helix that further associates into fibers, provides an insoluble scaffold that gives strength and form to the skin, tendons, bones, cornea and...

  15. Collagen Structure of Tendon Relates to Function

    Directory of Open Access Journals (Sweden)

    Marco Franchi

    2007-01-01

    Full Text Available A tendon is a tough band of fibrous connective tissue that connects muscle to bone, designed to transmit forces and withstand tension during muscle contraction. Tendon may be surrounded by different structures: 1 fibrous sheaths or retinaculae; 2 reflection pulleys; 3 synovial sheaths; 4 peritendon sheaths; 5 tendon bursae. Tendons contain a few cells, mostly represented by tenoblasts along with endothelial cells and some chondrocytes; b proteoglycans (PGs, mainly decorin and hyaluronan, and c collagen, mostly type I. Tendon is a good example of a high ordered extracellular matrix in which collagen molecules assemble into filamentous collagen fibrils (formed by microfibrils which aggregate to form collagen fibers, the main structural components. It represents a multihierarchical structure as it contains collagen molecules arranged in fibrils then grouped in fibril bundles, fascicles and fiber bundles that are almost parallel to the long axis of the tendon, named as primary, secondary and tertiary bundles. Collagen fibrils in tendons show prevalently large diameter, a D-period of about 67 nm and appear built of collagen molecules lying at a slight angle (< 5°. Under polarized light microscopy the collagen fiber bundles appear crimped with alternative dark and light transverse bands. In recent studies tendon crimps observed via SEM and TEM show that the single collagen fibrils suddenly changing their direction contain knots. These knots of collagen fibrils inside each tendon crimp have been termed “fibrillar crimps”, and even if they show different aspects they all may fulfil the same functional role. As integral component of musculoskeletal system, the tendon acts to transmit muscle forces to the skeletal system. There is no complete understanding of the mechanisms in transmitting/absorbing tensional forces within the tendon; however it seems likely that a flattening of tendon crimps may occur at a first stage of tendon stretching

  16. A new anthropometric phantom of the human leg for calibrating in vivo measurements of stable lead in bone using x-ray fluorescence

    International Nuclear Information System (INIS)

    Spitz, Henry; Jenkins, Mark; Lodwick, Jeffrey

    1997-01-01

    Full text. A new anthropometric phantom of the human leg has been developed for calibrating in vivo measurements of stable lead in the bone using x-ray fluorescence. The phantom reproduces the shape and radiological characteristics of the midshaft of the human leg and includes tissue substitutes for cortical bone, bone marrow, and muscle which have been formulated using polyurethanes and calcium carbonate to provide the desired characteristics of density x-ray attenuation, and calcium content. The phantom includes a set of simulated tibia bones, each containing a precisely known concentration of stable lead, that can be easily inserted into the leg. Formerly, of a set of plexiglas cylinders filled with plaster of-paris, each containing a known lead content, was the consensus standard calibration phantom. Tissue substitute materials used in the new anthropometric calibration phantom are much more uniform in density and composition than the plaster-of-paris phantoms and its realistic appearance provides a practical means of evaluating the variability in measurements results due to the changes in subject-detector positioning. Use of the new anthropometric calibration phantom results in a energy spectrum that closely resembles the spectrum observed when measuring a human subject. The energy spectrum produced by the plaster-of-paris phantom lacks the substantial Compton Scattering component produced by the leg muscle mass which leads to unrealistic estimates of in vivo measurement sensitivity. The minimum detection limit (MDL) for in vivo measurement of stable lead in bone, using an efficiency derived from the new anthropometric phantom, ranges from 18,6 parts per million (ppm) to 26,3 ppm using the K β1,3 /Elastic ratio or the K 1 /Elastic ratio, respectively. These values are significantly greater than the MDL cited in the literature obtained using a efficiency derived the conventional cylindrical plaster-of-paris phantom. Likewise, the realistic shape of the new

  17. Stable isotopes in Lithuanian bioarcheological material

    Science.gov (United States)

    Skipityte, Raminta; Jankauskas, Rimantas; Remeikis, Vidmantas

    2015-04-01

    Investigation of bioarcheological material of ancient human populations allows us to understand the subsistence behavior associated with various adaptations to the environment. Feeding habits are essential to the survival and growth of ancient populations. Stable isotope analysis is accepted tool in paleodiet (Schutkowski et al, 1999) and paleoenvironmental (Zernitskaya et al, 2014) studies. However, stable isotopes can be useful not only in investigating human feeding habits but also in describing social and cultural structure of the past populations (Le Huray and Schutkowski, 2005). Only few stable isotope investigations have been performed before in Lithuanian region suggesting a quite uniform diet between males and females and protein intake from freshwater fish and animal protein. Previously, stable isotope analysis has only been used to study a Stone Age population however, more recently studies have been conducted on Iron Age and Late medieval samples (Jacobs et al, 2009). Anyway, there was a need for more precise examination. Stable isotope analysis were performed on human bone collagen and apatite samples in this study. Data represented various ages (from 5-7th cent. to 18th cent.). Stable carbon and nitrogen isotope analysis on medieval populations indicated that individuals in studied sites in Lithuania were almost exclusively consuming C3 plants, C3 fed terrestrial animals, and some freshwater resources. Current investigation demonstrated social differences between elites and country people and is promising in paleodietary and daily life reconstruction. Acknowledgement I thank prof. dr. G. Grupe, Director of the Anthropological and Palaeoanatomical State Collection in Munich for providing the opportunity to work in her laboratory. The part of this work was funded by DAAD. Antanaitis-Jacobs, Indre, et al. "Diet in early Lithuanian prehistory and the new stable isotope evidence." Archaeologia Baltica 12 (2009): 12-30. Le Huray, Jonathan D., and Holger

  18. Comparison of recombinant human bone morphogenetic protein-2-infused absorbable collagen sponge, recombinant human bone morphogenetic protein-2-coated tricalcium phosphate, and platelet-rich fibrin-mixed tricalcium phosphate for sinus augmentation in rabbits

    Directory of Open Access Journals (Sweden)

    Chul-Hun Kim

    2017-09-01

    Conclusion: Our histological evaluation demonstrates that Type I ACS can be used as a carrier of rhBMP-2, and rhBMP-2+ACS showed rapid bone formation, remodeling, and calcification at Week 2 in rabbit.

  19. Radiostrontium, radiocesium and stable mineral composition of bones of domestic reindeer from Vågå, Norway

    Directory of Open Access Journals (Sweden)

    Hans Staaland

    1991-10-01

    Full Text Available Radiostrontium, radiocesium and macromineral concentrations were measured in metatarsal or metacarpal bones from 78 reindeer (59 calves and 19 adults in the Vågå reindeer herding district in Southern Norway. Samples were collected in the period August 1988 to May 1989. Radiocesium concentrations increased from August through the winter. Radiostrontium varied slightly around an average value 1810 Bq/kg DM. Mg concentrations decreased through the winter, the concentrations of other minerals and bone density showed only small variations. No signs of mineral deficiencies were observed. It is concluded that radiostrontium mainly originated from the Chernobyl nuclear accident.Radiostrontium, radiocesium og stabile mineraler in reinknokler fra Vågå, NorgeAbstract in Norwegian / Sammendrag: Innhold av radiostrontium, radiocesium og makromineraler ble målt i reinsdyrknokler (metatarsus og metacarpus innsamlet fra 78 dyr (59 kalver og 19 voksne tilhørende Vågå tamreinlag. Prøvene ble samlet i perioden august 1988 til mai 1989. Innholdet av radiocesium økte fra august og gjennom vinteren, mens innholdet av radiostrontium var temmelig konstant (1810 Bq/ kg tørrstoff. Magnesium innholdet avtok gjennom vinteren, mens innholdet av andre mineraler samt knoklenes tetthet varierte lite. Det ble ikke observert noen tegn på mineralmangel. Mesteparten av det radioaktive strontium kom fra atomkraftulykken i Tsjernobyl.

  20. Collagen vascular disease

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001223.htm Collagen vascular disease To use the sharing features on ... were previously said to have "connective tissue" or "collagen vascular" disease. We now have names for many ...

  1. Evaluation of nanohydroxyapaptite (nano-HA) coated epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes.

    Science.gov (United States)

    Chu, Chenyu; Deng, Jia; Man, Yi; Qu, Yili

    2017-09-01

    Collagen is the main component of extracellular matrix (ECM) with desirable biological activities and low antigenicity. Collagen materials have been widely utilized in guided bone regeneration (GBR) surgery due to its abilities to maintain space for hard tissue growth. However, pure collagen lacks optimal mechanical properties. In our previous study, epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes, with better biological activities and enhanced mechanical properties, may promote osteoblast proliferation, but their effect on osteoblast differentiation is not very significant. Nanohydroxyapatite (nano-HA) is the main component of mineral bone, which possesses exceptional bioactivity properties including good biocompatibility, high osteoconductivity and osteoinductivity, non-immunogenicity and non-inflammatory behavior. Herein, by analyzing the physical and chemical properties as well as the effects on promoting bone regeneration, we have attempted to present a novel EGCG-modified collagen membrane with nano-HA coating, and have found evidence that the novel collagen membrane may promote bone regeneration with a better surface morphology, without destroying collagen backbone. To evaluate the surface morphologies, chemical and mechanical properties of pure collagen membranes, epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes, nano-HA coated collagen membranes, nano-HA coated EGCG-collagen membranes, (ii) to evaluate the bone regeneration promoted by theses membranes. In the present study, collagen membranes were divided into 4 groups: (1) untreated collagen membranes (2) EGCG cross-linked collagen membranes (3) nano-HA modified collagen membranes (4) nano-HA modified EGCG-collagen membranes. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to evaluate surface morphologies and chemical properties, respectively. Mechanical properties were determined by differential scanning calorimeter (DSC

  2. Sugar cane consumption on Rapanui (Easter Island) and the indicence of caries : evidence from stable isotope values of human bone

    International Nuclear Information System (INIS)

    Leach, B.F.; Quinn, C.J.; Seelenfreund, A.

    2017-01-01

    Pre-European people on Rapanui are known to have had a high rate of dental caries. One proposed explanation for this is that the people consumed a considerable amount of sugar cane, as a thirst quencher, since fresh water is scarce on the island. Human bone samples were analysed by isotope analysis to see if this explanation could be sustained. Results for three isotopes δ 13 C, δ 15 N and δ 34 S were then used in a stochastic model to estimate the proportions of five main food types in the diet of these people. This indicated that daily consumption of dry raw sugar cane was only about 32 to 42 g per day. This is very low and sugar cane consumption is therefore unlikely to be the only cause of the high rate of dental caries. (author).

  3. Endocytic collagen degradation

    DEFF Research Database (Denmark)

    Madsen, Daniel H.; Jürgensen, Henrik J.; Ingvarsen, Signe Ziir

    2012-01-01

    Fibrosis of the liver and its end-stage, cirrhosis, represent major health problems worldwide. In these fibrotic conditions, activated fibroblasts and hepatic stellate cells display a net deposition of collagen. This collagen deposition is a major factor leading to liver dysfunction, thus making...... it crucially important to understand both the collagen synthesis and turnover mechanisms in this condition. Here we show that the endocytic collagen receptor, uPARAP/Endo180, is a major determinant in governing the balance between collagen deposition and degradation. Cirrhotic human livers displayed a marked...... importance of this collagen receptor in vivo, liver fibrosis was induced in uPARAP/Endo180-deficient mice and littermate wild-type mice by chronic CCl(4) administration. A strong up-regulation of uPARAP/Endo180 was observed in wild-type mice, and a quantitative comparison of collagen deposits in the two...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-04-15

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

  5. Assessment of low amounts of meat and bone meal in the diet of laying hens by using stable isotopes

    Directory of Open Access Journals (Sweden)

    Luciene Aparecida Madeira

    2015-04-01

    Full Text Available The aim of this study was to assess whether the inclusion of low amounts of ingredients such as wheat bran, corn gluten and yeast in the diet of laying hens can interfere with the traceability of meat and bone meal (MBM in eggs and its fractions (albumen and yolk. We used 256 laying hens distributed across eight treatment groups, which consisted of a diet based on corn-soybean-wheat (CSW bran meal and other diets that had additions comprising gluten and/or (MBM and/or yeast. To analyse the isotopic ratios (13C:12C and 15N:14N, on the 28th and 56th days, 16 eggs were randomly taken for each treatment (four for each repetition, where eight eggs (two for each repetition were used to harvest yolk and albumen samples and the remaining eight (two for each repetition were used to analyse the whole egg. We concluded that detection of 2.0% MBM in the egg and its fractions is possible; however, the results for treatments containing gluten and yeast were not different from those containing MBM. Therefore, the inclusion of 3.0% gluten and/or yeast does not result in different ?13C and ?15N isotopic values in the egg and its fractions compared to the values obtained with the addition of 2.0% MBM in the diet.

  6. [Study on the acid hydrolysis, fiber remodeling and bionics mineralization of rat tail tendon collagen type Ⅰ].

    Science.gov (United States)

    Zhang, Zhan; Zhang, Chun; Guo, Qiaofeng

    2016-05-25

    Objective: To produce bionic bone material that is consistent with human bone in chemical composition and molecular structure using rat tail tendon collagen type Ⅰ. Methods: The type Ⅰcollagen derived from rat tail was extracted by acetic acid to form collagen fibers. The reconstructed collagen fibers were placed in the mineralized solution to mimic bone mineralization for 2-6 days. Bone mineralization was observed by transmission electron microscopy and electron diffraction. Results: Collagen fibers with characteristic D-Band structure were reconstructed by using rat tail tendon collagen type Ⅰ extracted with acid hydrolysis method. Transmission electron microscopy and electron diffraction showed that calcium hydroxyapatite precursor infiltrated into the collagen fibers, and the collagen fibers were partially mineralized after 2 days of mineralization; the collagen fibers were completely mineralized and bionic bone material of typeⅠ collagen/calcium hydroxyapatite was formed after 6 days of mineralization. Conclusion: The collagen type Ⅰ can be extracted from rat tail tendon by acid hydrolysis method, and can be reformed and mineralized to form the bionic bone material which mimics human bone in chemical composition and the molecular structure.

  7. Mineralized Collagen: Rationale, Current Status, and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Zhi-Ye Qiu

    2015-07-01

    Full Text Available This paper presents a review of the rationale for the in vitro mineralization process, preparation methods, and clinical applications of mineralized collagen. The rationale for natural mineralized collagen and the related mineralization process has been investigated for decades. Based on the understanding of natural mineralized collagen and its formation process, many attempts have been made to prepare biomimetic materials that resemble natural mineralized collagen in both composition and structure. To date, a number of bone substitute materials have been developed based on the principles of mineralized collagen, and some of them have been commercialized and approved by regulatory agencies. The clinical outcomes of mineralized collagen are of significance to advance the evaluation and improvement of related medical device products. Some representative clinical cases have been reported, and there are more clinical applications and long-term follow-ups that currently being performed by many research groups.

  8. Animal Management at the Ancient Metropolis of Teotihuacan, Mexico: Stable Isotope Analysis of Leporid (Cottontail and Jackrabbit) Bone Mineral.

    Science.gov (United States)

    Somerville, Andrew D; Sugiyama, Nawa; Manzanilla, Linda R; Schoeninger, Margaret J

    2016-01-01

    Human-animal interactions have played crucial roles in the development of complex societies across the globe. This study examines the human-leporid (cottontail and jackrabbit) relationship at the pre-Hispanic (AD 1-550) city of Teotihuacan in the Basin of Mexico and tests the hypothesis that leporids were managed or bred for food and secondary products within the urban core. We use stable isotope analysis (δ13Capatite and δ18Oapatite) of 134 leporid specimens from five archaeological contexts within the city and 13 modern specimens from across central Mexico to quantify aspects of leporid diet and ecology. The results demonstrate that leporids from Oztoyahualco, a residential complex associated with a unique rabbit sculpture and archaeological traces of animal butchering, exhibit the highest δ13Capatite values of the sample. These results imply greater consumption of human-cultivated foods, such as maize (Zea mays), by cottontails and jackrabbits at this complex and suggest practices of human provisioning. A lack of significant differences in δ18Oapatite values between ancient and modern leporids and between Oztoyahualco and other locations within Teotihuacan indicates generally similar relative humidity from sampled contexts. Results of this study support the notion that residents provisioned, managed, or bred leporids during the height of the city, and provide new evidence for mammalian animal husbandry in the ancient New World.

  9. Animal Management at the Ancient Metropolis of Teotihuacan, Mexico: Stable Isotope Analysis of Leporid (Cottontail and Jackrabbit Bone Mineral.

    Directory of Open Access Journals (Sweden)

    Andrew D Somerville

    Full Text Available Human-animal interactions have played crucial roles in the development of complex societies across the globe. This study examines the human-leporid (cottontail and jackrabbit relationship at the pre-Hispanic (AD 1-550 city of Teotihuacan in the Basin of Mexico and tests the hypothesis that leporids were managed or bred for food and secondary products within the urban core. We use stable isotope analysis (δ13Capatite and δ18Oapatite of 134 leporid specimens from five archaeological contexts within the city and 13 modern specimens from across central Mexico to quantify aspects of leporid diet and ecology. The results demonstrate that leporids from Oztoyahualco, a residential complex associated with a unique rabbit sculpture and archaeological traces of animal butchering, exhibit the highest δ13Capatite values of the sample. These results imply greater consumption of human-cultivated foods, such as maize (Zea mays, by cottontails and jackrabbits at this complex and suggest practices of human provisioning. A lack of significant differences in δ18Oapatite values between ancient and modern leporids and between Oztoyahualco and other locations within Teotihuacan indicates generally similar relative humidity from sampled contexts. Results of this study support the notion that residents provisioned, managed, or bred leporids during the height of the city, and provide new evidence for mammalian animal husbandry in the ancient New World.

  10. Combining histology, stable isotope analysis and ZooMS collagen fingerprinting to investigate the taphonomic history and dietary behaviour of extinct giant tortoises from the Mare aux Songes deposit on Mauritius

    NARCIS (Netherlands)

    van der Sluis, L.G.; Hollund, H.I.; Buckley, M.; de Louw, P.G.B.; Rijsdijk, K.F.; Kars, H.

    2014-01-01

    Taphonomic research of bones can provide additional insight into a site's formation and development, the burial environment and ongoing post-mortem processes. A total of 30 tortoise (Cylindraspis) femur bone samples from the Mare aux Songes site (Mauritius) were studied histologically, assessing

  11. Collagen synthesis in human musculoskeletal tissues and skin

    DEFF Research Database (Denmark)

    Babraj, J A; Cuthbertson, D J R; Smith, K

    2005-01-01

    . In postabsorptive, healthy young men (28 +/- 6 yr) synthetic rates for tendon, ligament, muscle, and skin collagen were 0.046 +/- 0.005, 0.040 +/- 0.006, 0.016 +/- 0.002, and 0.037 +/- 0.003%/h, respectively (means +/- SD). In postabsorptive, healthy elderly men (70 +/- 6 yr) the rate of skeletal muscle collagen......We have developed a direct method for the measurement of human musculoskeletal collagen synthesis on the basis of the incorporation of stable isotope-labeled proline or leucine into protein and have used it to measure the rate of synthesis of collagen in tendon, ligament, muscle, and skin...

  12. Proximal collagenous gastroenteritides:

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Riis, Lene Buhl; Danese, Silvio

    2014-01-01

    AIM: While collagenous colitis represents the most common form of the collagenous gastroenteritides, the collagenous entities affecting the proximal part of the gastrointestinal tract are much less recognized and possibly overlooked. The aim was to summarize the latest information through...... a systematic review of collagenous gastritis, collagenous sprue, and a combination thereof. METHOD: The search yielded 117 studies which were suitable for inclusion in the systematic review. Excluding repeated cases, 89 case reports and 28 case series were reported, whereas no prospective studies...... with or without control groups were identified. Further, no randomized, controlled trials were identified. The total number of patients with proximal collagenous gastroenteritides reported was 330. RESULTS: An overview of clinical presentations, prognosis, pathophysiology and histopathology, as well as management...

  13. Mimicking the Nanostructure of Bone: Comparison of Polymeric Process-Directing Agents

    Directory of Open Access Journals (Sweden)

    Laurie B. Gower

    2010-12-01

    Full Text Available The nanostructure of bone has been replicated using a polymer-induced liquid-precursor (PILP mineralization process. This polymer-mediated crystallization process yields intrafibrillar mineralization of collagen with uniaxially-oriented hydroxyapatite crystals. The process-directing agent, an anionic polymer which we propose mimics the acidic non-collagenous proteins associated with bone formation, sequesters calcium and phosphate ions to form amorphous precursor droplets that can infiltrate the interstices of collagen fibrils. In search of a polymeric agent that produces the highest mineral content in the shortest time, we have studied the influence of various acidic polymers on the in vitro mineralization of collagen scaffolds via the PILP process. Among the polymers investigated were poly-L-aspartic acid (PASP, poly-L-glutamic acid (PGLU, polyvinylphosphonic acid (PVPA, and polyacrylic acid (PAA. Our data indicate that PASP and the combination of PGLU/PASP formed stable mineralization solutions, and yielded nano-structured composites with the highest mineral content. Such studies contribute to our goal of preparing biomimetic bone graft substitutes with composition and structure that mimic bone.

  14. Regulators of Collagen Fibrillogenesis during Molar Development in the Mouse

    Directory of Open Access Journals (Sweden)

    Ivana Zvackova

    2017-08-01

    Full Text Available Development of mammalian teeth and surrounding tissues includes time–space changes in the extracellular matrix composition and organization. This requires complex control mechanisms to regulate its synthesis and remodeling. Fibril-associated collagens with interrupted triple helices (FACITs and a group of small leucine-rich proteoglycans (SLRPs are involved in the regulation of collagen fibrillogenesis. Recently, collagen type XII and collagen type XIV, members of the FACITs family, were found in the peridental mesenchyme contributing to alveolar bone formation. This study was designed to follow temporospatial expression of collagen types XIIa and XIVa in mouse first molar and adjacent tissues from embryonic day 13, when the alveolar bone becomes morphologically apparent around the molar tooth bud, until postnatal day 22, as the posteruption stage. The patterns of decorin, biglycan, and fibromodulin, all members of the SLRPs family and interacting with collagens XIIa and XIVa, were investigated simultaneously. The situation in the tooth was related to what happens in the alveolar bone, and both were compared to the periodontal ligament. The investigation provided a complex localization of the five antigens in soft tissues, the dental pulp, and periodontal ligaments; in the mineralized tissues, predentin/dentin and alveolar bone; and junction between soft and hard tissues. The results illustrated developmentally regulated and tissue-specific changes in the balance of the two FACITs and three SLRPs.

  15. A stable analogue of thromboxane A2, 9,11-epithio-11,12-methanothromboxane A2, stimulates bone resorption in vitro and osteoclast-like cell formation in mouse marrow culture.

    Science.gov (United States)

    Saito, S; Yamasaki, K; Yamada, S; Matsumoto, A; Akatsu, T; Takahashi, N; Shibasaki, Y; Suda, T; Fukuhara, T

    1991-01-01

    Thromboxane A2 (TXA2) is a powerful promoter of platelet aggregation and smooth muscle contraction. However, this compound is highly unstable and is rapidly hydrated to a more stable metabolite, thromboxane B2 (TXB2). TXA2 has been considered to be involved in bone resorption, in particular bone loss caused by inflammatory diseases and by orthodontic treatment. However precise mechanisms of bone resorption caused by TXA2 have not yet been proved because of its highly unstable nature. Recently, a chemically stable analogue of TXA2, 9,11-epithio-11,12-methanothromboxane A2 (STA2), was successfully synthesized. Using this synthetic compound, we examined its in vitro bone resorbing activity and induction of osteoclast-like cells in a mouse marrow culture system in comparison with related compounds with bone resorbing activity. Like prostaglandin E2 (PGE2), a well-known bone resorbing agent, STA2 time- and dose-dependently stimulated the release of 45Ca from prelabelled mouse calvariae. Both STA2 and PGE2 induced the accumulation of cAMP in mouse calvariae. The TXA2 antagonist, ONO-3708, inhibited STA2-induced release of 45Ca. TXB2 induced neither bone resorption nor cAMP accumulation. When mouse marrow cells were cultured with STA2 for 8 days, osteoclast-like multinucleated cells appeared in parallel with the increase of the amount of STA2 added. Again TXB2 showed no effect on osteoclast-like cell formation. These results indicate a role for TXA2 in some form of bone resorption.

  16. BIOCHEMICAL MARKERS OF BONE RESORPTION AND HORMONAL REGULATION OF BONE METABOLISM FOLLOWING LIVER TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    V. P. Buzulina

    2013-01-01

    Full Text Available Aim. Comparative evaluation of two biochemical markers of bone resorption and hormonal regulation of bone metabolism in liver recipients. Methods and results. Bоne densitometry of L2–L4 and neck of femur, serum level of some hormones (PTH, vitamin D3, estradiol, testosterone regulating osteoclastogenesis as well as com- parative analyses of two bone resorption markers β-crosslaps and tartrate-resistant acid phosphatase type 5b (TRAP-5b were fulfilled in patients after orthotopic liver transplantation (OLT. In 1 month after OLT bone density reduction of L2–L4 and neck of femur; decrease of vitamin D3, estradiol in women, testosterone in men and increase levels of bone resorption markers were observed. In 1 and 2 years after OLT the rise of bone density, increased levels of PTH, estradiol, testosterone and decreased β-crosslaps levels were revealed, while vitamin D3 and TRAP-5b levels remained stable. Conclusion. TRAP-5b was found to be a more speciffic marker of bone resorption, independent from collagen metabolism in liver. Osteoporosis defined in long-term period after OLT was associated with higher TRAP-5b and revialed in women with low estradiol level. 

  17. One-stage reconstruction of soft tissue defects with the sandwich technique: Collagen-elastin dermal template and skin grafts

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

    Full Text Available Background : A full-thickness soft tissue defect closure often needs complex procedures. The use of dermal templates can be helpful in improving the outcome. Objective : The objective was to evaluate a sandwich technique combining the dermal collagen-elastin matrix with skin grafts in a one-stage procedure. Materials and Methods : Twenty-three patients with 27 wounds were enrolled in this prospective single-centre observational study. The mean age was 74.8 ± 17.2 years. Included were full-thickness defects with exposed bone, cartilage and/ or tendons. The dermal collagen-elastin matrix was applied onto the wound bed accomplished by skin transplants, i.e. ′sandwich′ transplantation. In six wounds, the transplants were treated with intermittent negative pressure therapy. Results : The size of defects was ≤875 cm 2 . The use of the dermal template resulted in a complete and stable granulation in 100% of wounds. Seventeen defects showed a complete closure and 19 achieved a complete granulation with an incomplete closure. There was a marked pain relief. No adverse events were noted due to the dermal template usage. Conclusions : Sandwich transplantation with the collagen-elastin matrix is a useful tool when dealing with full-thickness soft tissue defects with exposed bone, cartilage or tendons.

  18. Collagen type XV and the ?osteogenic status?

    OpenAIRE

    Lisignoli, Gina; Lambertini, Elisabetta; Manferdini, Cristina; Gabusi, Elena; Penolazzi, Letizia; Paolella, Francesca; Angelozzi, Marco; Casagranda, Veronica; Piva, Roberta

    2017-01-01

    Abstract We have previously demonstrated that collagen type XV (ColXV) is a novel bone extracellular matrix (ECM) protein. It is well known that the complex mixture of multiple components present in ECM can help both to maintain stemness or to promote differentiation of stromal cells following change in qualitative characteristics or concentrations. We investigated the possible correlation between ColXV expression and mineral matrix deposition by human mesenchymal stromal cells (hMSCs) with d...

  19. Do oxygen isotope values in collagen reflect the ecology and physiology of neotropical mammals?

    Directory of Open Access Journals (Sweden)

    Brooke eCrowley

    2015-11-01

    Full Text Available Stable isotope data provide insight into the foraging ecology of animals. Traditionally, carbon and nitrogen isotope values have been used to infer dietary and habitat preferences. Oxygen isotopes are used less frequently but may complement the ecological information provided by carbon and nitrogen, particularly in densely forested or arid environments. Additionally, because oxygen is preserved in both bioapatite and collagen, it is useful for paleoecological studies. To investigate the suitability of oxygen isotopes for complementing and building on ecological applications of carbon and nitrogen isotopes, we analyze all three isotopes in bone collagen for nearly identical assemblages of Costa Rican mammals in two ecologically distinct habitats - a evergreen rainforest and a seasonal dry forest. We assess the degree to which differences in habitat, activity pattern, diet, arboreality, and thermoregulation are revealed by each of the isotope systems. Our results highlight the potential of oxygen isotopes in modern and paleoecological contexts. In addition to reflecting habitat type, oxygen isotope values in collagen distinguish species on the basis of vertical habitat stratification and drinking behavior. Within a locality, individuals with low oxygen isotope values likely track meteoric water, whereas those with elevated values most likely consume evaporatively-enriched plant tissues, such as canopy leaves. These patterns will be useful in reconstructing paleoenvironments and interpreting ecological differences among taxa both extant and extinct.

  20. Comparison of thermal properties of fish collagen and bovine collagen in the temperature range 298-670K.

    Science.gov (United States)

    Gauza-Włodarczyk, Marlena; Kubisz, Leszek; Mielcarek, Sławomir; Włodarczyk, Dariusz

    2017-11-01

    The increased interest in fish collagen is a consequence of the risk of exposure to Creutzfeld-Jacob disease (CJD) and the bovine spongiform encephalopathy (BSE), whose occurrence is associated with prions carried by bovine collagen. Collagen is the main biopolymer in living organisms and the main component of the skin and bones. Until the discovery of the BSE, bovine collagen had been widely used. The BSE epidemic increased the interest in new sources of collagen such as fish skin collagen (FSC) and its properties. Although the thermal properties of collagen originating from mammals have been well described, less attention has been paid to the thermal properties of FSC. Denaturation temperature is a particularly important parameter, depending on the collagen origin and hydration level. In the reported experiment, the free water and bound water release processes along with thermal denaturation process were studied by means of the differential scanning calorimetry (DSC). Measurements were carried out using a DSC 7 instrument (Elmer-Perkin), in the temperature range 298-670K. The study material was FSC derived by acidic hydration method. The bovine Achilles tendon (BAT) collagen type I was used as the control material. The thermograms recorded revealed both, exothermic and endothermic peaks. For both materials, the peaks in the temperature range of 330-360K were assigned to the release of free water and bound water. The denaturation temperatures of FSC and BAT collagen were determined as 420K and 493K, respectively. Thermal decomposition process was observed at about 500K for FSC and at about 510K for BAT collagen. These results show that FSC is less resistant to high temperature than BAT collagen. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Collagen derived serum markers in carcinoma of the prostate

    DEFF Research Database (Denmark)

    Rudnicki, M; Jensen, L T; Iversen, P

    1995-01-01

    Three new collagen markers deriving from the collagenous matrix, e.g. carboxyterminal propeptide of type I procollagen (PICP), carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP), and aminoterminal propeptide of type III procollagen (PIIINP) were used for the diagnose...... of prostatic bone metastases. Blood samples were obtained prior to biopsy or TURP. Serum PICP, PIIINP and ICTP were measured with commercial available RIAs and PSA by IRMA. Serum PSA was increased in patients with local prostatic cancer compared with patients with hyperplasia (p

  2. A collagen-targeted biomimetic RGD peptide to promote osteogenesis.

    Science.gov (United States)

    Visser, Rick; Arrabal, Pilar M; Santos-Ruiz, Leonor; Fernandez-Barranco, Raul; Becerra, Jose; Cifuentes, Manuel

    2014-01-01

    Osteogenesis is a complex, multifactorial process in which many different signals interact. The bone morphogenetic proteins (BMPs) are the most potent inducers of osteoblastic differentiation, although very high doses of BMPs in combination with collagen type I formulations have to be used for clinical applications. Although integrin-binding arginine-glycine-aspartic acid (RGD) biomimetic peptides have shown some promising abilities to promote the attachment of cells to biomaterials and to direct their differentiation, the linking of these peptides to collagen sponges usually implies chemical manipulation steps. In this study, we describe the design and characterization of a synthetic collagen-targeted RGD biomimetic (CBD-RGD) peptide formed from a collagen-binding domain derived from the von Willebrand factor and the integrin-binding RGD sequence. This peptide was demonstrated to bind to absorbable collagen type I sponges (ACSs) without performing any chemical linking, and to induce the differentiation of MC3T3-E1 mouse preosteoblasts and rat bone marrow-derived mesenchymal stem cells. Furthermore, in vivo experiments showed that ACSs functionalized with CBD-RGD and loaded with a subfunctional dose of BMP-2-formed ectopic bone in rats, while nonfunctionalized sponges loaded with the same amount of BMP-2 did not. These results indicate that the combination of this biomimetic peptide with the currently used collagen+BMP system might be a promising approach to improve osteogenesis and to reduce the doses of BMPs needed in clinical orthopedics.

  3. Molecular crowding of collagen: a pathway to produce highly-organized collagenous structures.

    Science.gov (United States)

    Saeidi, Nima; Karmelek, Kathryn P; Paten, Jeffrey A; Zareian, Ramin; DiMasi, Elaine; Ruberti, Jeffrey W

    2012-10-01

    Collagen in vertebrate animals is often arranged in alternating lamellae or in bundles of aligned fibrils which are designed to withstand in vivo mechanical loads. The formation of these organized structures is thought to result from a complex, large-area integration of individual cell motion and locally-controlled synthesis of fibrillar arrays via cell-surface fibripositors (direct matrix printing). The difficulty of reproducing such a process in vitro has prevented tissue engineers from constructing clinically useful load-bearing connective tissue directly from collagen. However, we and others have taken the view that long-range organizational information is potentially encoded into the structure of the collagen molecule itself, allowing the control of fibril organization to extend far from cell (or bounding) surfaces. We here demonstrate a simple, fast, cell-free method capable of producing highly-organized, anistropic collagen fibrillar lamellae de novo which persist over relatively long-distances (tens to hundreds of microns). Our approach to nanoscale organizational control takes advantage of the intrinsic physiochemical properties of collagen molecules by inducing collagen association through molecular crowding and geometric confinement. To mimic biological tissues which comprise planar, aligned collagen lamellae (e.g. cornea, lamellar bone or annulus fibrosus), type I collagen was confined to a thin, planar geometry, concentrated through molecular crowding and polymerized. The resulting fibrillar lamellae show a striking resemblance to native load-bearing lamellae in that the fibrils are small, generally aligned in the plane of the confining space and change direction en masse throughout the thickness of the construct. The process of organizational control is consistent with embryonic development where the bounded planar cell sheets produced by fibroblasts suggest a similar confinement/concentration strategy. Such a simple approach to nanoscale

  4. Chitosan Composites for Bone Tissue Engineering—An Overview

    Directory of Open Access Journals (Sweden)

    Jayachandran Venkatesan

    2010-08-01

    Full Text Available Bone contains considerable amounts of minerals and proteins. Hydroxyapatite [Ca10(PO46(OH2] is one of the most stable forms of calcium phosphate and it occurs in bones as major component (60 to 65%, along with other materials including collagen, chondroitin sulfate, keratin sulfate and lipids. In recent years, significant progress has been made in organ transplantation, surgical reconstruction and the use of artificial protheses to treat the loss or failure of an organ or bone tissue. Chitosan has played a major role in bone tissue engineering over the last two decades, being a natural polymer obtained from chitin, which forms a major component of crustacean exoskeleton. In recent years, considerable attention has been given to chitosan composite materials and their applications in the field of bone tissue engineering due to its minimal foreign body reactions, an intrinsic antibacterial nature, biocompatibility, biodegradability, and the ability to be molded into various geometries and forms such as porous structures, suitable for cell ingrowth and osteoconduction. The composite of chitosan including hydroxyapatite is very popular because of the biodegradability and biocompatibility in nature. Recently, grafted chitosan natural polymer with carbon nanotubes has been incorporated to increase the mechanical strength of these composites. Chitosan composites are thus emerging as potential materials for artificial bone and bone regeneration in tissue engineering. Herein, the preparation, mechanical properties, chemical interactions and in vitro activity of chitosan composites for bone tissue engineering will be discussed.

  5. Design and synthesis of collagen mimetic peptide derivatives for studying triple helix assembly and collagen mimetic peptide-collagen binding interaction

    Science.gov (United States)

    Mo, Xiao

    2008-10-01

    Collagen is the principal tensile clement of the extra-cellular matrix in mammals and is the basic scaffold for cells and tissues. Collagen molecules are comprised of homo-trimeric helices (e.g. collagen type II and type III), ABB type hetero-trimeric helices (e.g. collagen type I, type IV, and type V), or ABC type hetero-trimeric helices (e.g. type V). Mimicry of collagen structures can help elucidate collagen triple helical conformation and provide insights into making novel collagen-like biomaterials. Our group previously reported a new physical collagen modification method, which was based on non-covalent interaction between collagen mimetic peptide (CMP: -(Pro-Hyp-Gly) x-) and natural collagen. We hypothesized that CMP binds to collagen through a process involving both strand invasion and triple helix assembly. The aim of this dissertation is to study structural formation and stability of collagen triple helix, and to investigate CMP-collagen binding interactions using two types of CMP derivatives: covalently templated CMP trimer and CMP-nanoparticle conjugates. We demonstrated that covalently templated ABB type CMP hetero-trimers could be prepared by a versatile synthetic strategy involving both solid phase and solution peptide coupling. Our thermal melting studies showed that the templated CMP hetero-trimers formed collagen-like triple helices and their folding kinetics correlated with the amino acid compositions of the individual CMP strands. We also studied the thermal melting behavior and folding kinetics of a templated hetero-trimer complex comprised of CMP and a peptide derived from collagen. This synthetic strategy can be readily extended to synthesize other ABB type hetero-trimers to investigate their local melting behavior and biological activity. We also prepared colloidally stable CMP functionalized gold nanoparticles (Au-CMPs) as a TEM marker for investigating the CMP-collagen interaction. Au-CMP showed preferential binding to collagen fiber's gap

  6. Collagen: A review on its sources and potential cosmetic applications.

    Science.gov (United States)

    Avila Rodríguez, María Isabela; Rodríguez Barroso, Laura G; Sánchez, Mirna Lorena

    2018-02-01

    Collagen is a fibrillar protein that conforms the conjunctive and connective tissues in the human body, essentially skin, joints, and bones. This molecule is one of the most abundant in many of the living organisms due to its connective role in biological structures. Due to its abundance, strength and its directly proportional relation with skin aging, collagen has gained great interest in the cosmetic industry. It has been established that the collagen fibers are damaged with the pass of time, losing thickness and strength which has been strongly related with skin aging phenomena [Colágeno para todo. 60 y más. 2016. http://www.revista60ymas.es/InterPresent1/groups/revistas/documents/binario/ses330informe.pdf.]. As a solution, the cosmetic industry incorporated collagen as an ingredient of different treatments to enhance the user youth and well-being, and some common presentations are creams, nutritional supplement for bone and cartilage regeneration, vascular and cardiac reconstruction, skin replacement, and augmentation of soft skin among others [J App Pharm Sci. 2015;5:123-127]. Nowadays, the biomolecule can be obtained by extraction from natural sources such as plants and animals or by recombinant protein production systems including yeast, bacteria, mammalian cells, insects or plants, or artificial fibrils that mimic collagen characteristics like the artificial polymer commercially named as KOD. Because of its increased use, its market size is valued over USD 6.63 billion by 2025 [Collagen Market By Source (Bovine, Porcine, Poultry, Marine), Product (Gelatin, Hydrolyzed Collagen), Application (Food & Beverages, Healthcare, Cosmetics), By Region, And Segment Forecasts, 2014 - 2025. Grand View Research. http://www.grandviewresearch.com/industry-analysis/collagen-market. Published 2017.]. Nevertheless, there has been little effort on identifying which collagen types are the most suitable for cosmetic purposes, for which the present review will try to enlighten

  7. The adsorption of 117Snm(IV)-EDTMP on collagen

    International Nuclear Information System (INIS)

    Yang Yuqing; Luo Shunzhong; Pu Manfei; Bing Wenzeng; He Jiaheng; Wang Guanquan

    2002-01-01

    The adsorption and desorption characteristics of 117 Sn m (IV)-EDTMP on collage are studied, and compared with that on HA. The results show that the effects of pH and temperature on adsorption of 117 Sn m (IV)-EDTMP on collagen are similar to those on HA, and that the adsorption equilibrium and adsorption model of 117 Sn m (IV)-EDTMP on collagen are completely different from those on HA; 117 Sm m -EDTMP absorbed on collagen are extremely stable and almost could not be desorbed with normal saline or EDTMP

  8. Current understanding of osteoconduction in bone regeneration.

    Science.gov (United States)

    Cornell, C N; Lane, J M

    1998-10-01

    Bone tissue is osteoconductive. In particular, cancellous bone with its porous and highly interconnected trabecular architecture allows easy ingrowth of surrounding tissues. When placed in an osseous environment, living tissue for the host bed migrates into the cancellous structure, which results in new bone formation and incorporation of that structure. This is the process of osteoconduction. The mineral and collagenous components of bone are osteoconductive. Osteoconduction also is observed in fabricated materials that have porosity similar to that of bone structure. Corallin ceramics, hydroxyapatite beads, and combinations of hydroxyapatite and collagen all have osteoconductive properties, and porous metals and biodegradable polymers. Osteoconduction appears to be optimized in devices that mimic not only bone structure, but also bone chemistry. The incorporation of calcium salts and collagen by osteoconductive matrices leads to more complete ingrowth with new bone formation.

  9. Bone marrow stroma in idiopathic myelofibrosis and other haematological diseases. An immunohistochemical study

    DEFF Research Database (Denmark)

    Lisse, I; Hasselbalch, H; Junker, P

    1991-01-01

    Bone marrow stroma was investigated immunohistochemically in 31 patients with haematological diseases, mainly idiopathic myelofibrosis (n = 8) and related chronic myeloproliferative disorders (n = 14). The bone marrow from patients with idiopathic myelofibrosis and some CML patients showed marked...... staining reactions with antibodies against type III procollagen (pN collagen), type IV collagen, fragment P1 of laminin and factor VIII. Patients with osteomyelosclerosis had particularly increased collagen content, including both newly deposited type III collagen (pN collagen) and mature collagen fibres....... As in normal bone marrow, argyrophilic fibres and type III collagen displayed a close co-distribution, which was also demonstrated for type IV collagen and laminin. While normal bone marrow sinusoids had discontinuous basement membranes, fibrosing bone marrow was characterized by endothelial cell proliferation...

  10. Complementary roles of intracellular and pericellular collagen degradation pathways in vivo

    DEFF Research Database (Denmark)

    Wagenaar-Miller, Rebecca A; Engelholm, Lars H; Gavard, Julie

    2007-01-01

    Collagen degradation is essential for cell migration, proliferation, and differentiation. Two key turnover pathways have been described for collagen: intracellular cathepsin-mediated degradation and pericellular collagenase-mediated degradation. However, the functional relationship between these ...... failure and poor survival of cartilage- and bone-forming cells within their collagen-rich microenvironment. These findings have important implications for the use of pharmacological inhibitors of collagenase activity to prevent connective tissue destruction in a variety of diseases....

  11. Biological Safety of Fish (Tilapia Collagen

    Directory of Open Access Journals (Sweden)

    Kohei Yamamoto

    2014-01-01

    Full Text Available Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the http://dx.doi.org/10.13039/501100003478 Ministry of Health, Labour and Welfare. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine.

  12. Biological safety of fish (tilapia) collagen.

    Science.gov (United States)

    Yamamoto, Kohei; Igawa, Kazunari; Sugimoto, Kouji; Yoshizawa, Yuu; Yanagiguchi, Kajiro; Ikeda, Takeshi; Yamada, Shizuka; Hayashi, Yoshihiko

    2014-01-01

    Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia) atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin) yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the Ministry of Health, Labour and Welfare of Japan. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine.

  13. Pyridinium cross-links in heritable disorders of collagen

    Energy Technology Data Exchange (ETDEWEB)

    Pasquali, M.; Still, M.J.; Dembure, P.P. [Emory Univ., Atlanta, GA (United States)] [and others

    1995-12-01

    Ehlers-Danlos syndrome (EDS) is a heterogeneous group of inherited disorders of collagen that is characterized by skin fragility, skin hyperextensibility, and joint hypermobility. EDS type VI is caused by impaired collagen lysyl hydroxylase (procollagen-lysine, 2-oxoglutarate 5-dioxygenase; E.C.1.14.11.4), the ascorbate-dependent enzyme that hydroxylates lysyl residues on collagen neopeptides. Different alterations in the gene for collagen lysyl hydroxylase have been reported in families with EDS type VI. In EDS type VI, impairment of collagen lysyl hydroxylase results in a low hydroxylysine content in mature collagen. Hydroxylysine is a precursor of the stable, covalent, intermolecular cross-links of collagen, pyridinoline (Pyr), and deoxypyridinoline (Dpyr). Elsewhere we reported in preliminary form that patients with EDS type VI had a distinctive alteration in the urinary excretion of Pyr and Dpyr. In the present study, we confirm that the increased Dpyr/Pyr ratio is specific for EDS type VI and is not observed in other inherited or acquired collagen disorders. In addition, we find that skin from patients with EDS type VI has reduced Pyr and increased Dpyr, which could account for the organ pathology. 19 refs., 1 tab.

  14. Mistura de proteínas morfogenéticas ósseas, hidroxiapatita, osso inorgânico e colágeno envolta por membrana de pericárdio no preenchimento de defeito ósseo segmentar em coelhos Mixture of bone morphogenetic protein, hydroxyapatite, inorganic bone and collagen interposed by pericardium barrier membrane in the filling of the segmental bone defect in rabbits

    Directory of Open Access Journals (Sweden)

    R.B. Ciani

    2006-02-01

    Full Text Available Avaliou-se o uso de biomaterial de origem bovina na regeneração de defeitos ósseos segmentares empregando-se 12 coelhos, fêmeas, da raça Norfolk, com idade de seis meses e pesos entre 3 e 4,5kg. Realizou-se falha segmentar bilateral de um centímetro de comprimento na diáfise do rádio, com inclusão do periósteo. No membro direito, o defeito foi delimitado por membrana de pericárdio liofilizada, contendo em seu interior mistura de proteínas morfogenéticas ósseas adsorvidas a hidroxiapatita, colágeno liofilizado e osso inorgânico. No membro esquerdo, o defeito não recebeu tratamento. Radiografias foram obtidas ao término do procedimento cirúrgico e aos sete, 30, 60, 90, 120 e 150 dias de pós-operatório. Após eutanásia de seis coelhos aos 60 dias e seis aos 150 dias de pós-cirúrgico, os resultados radiográficos e histológicos mostraram que a regeneração óssea foi inibida nos defeitos segmentares tratados com o biomaterial.Biomaterials of bovine origin in regenerating segmental bone defects were evaluated. Twelve six-month old Norfolk rabbits, weighting 3 to 4.5kg were used. A 1cm long segmental defect was created in the radial diaphysis, including the periosteum, of both forelimbs. In the right forelimb, the defect was filled using a mixture of bone morphogenic proteins adsorbed to hydroxyapatite, agglutinant of lyophilized collagen in granules and anorganic cortical bone in granules delimited by a pericardial membrane. In the left forelimb, the defect did not receive treatment and served as a control. Radiographies were taken immediately after surgery and at seven, 30, 60, 90, 120 and 150 days post-operatively. Six rabbits were euthanized at 60 days and the other six at 150 days post-surgery for histological evaluation. Radiographic and histological results revealed that bone regeneration was inhibited in the segmental defects receiving biomaterials.

  15. Osteoinductive PolyHIPE Foams as Injectable Bone Grafts.

    Science.gov (United States)

    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.

  16. Comparative evaluation of a biomimic collagen/hydroxyapatite/β-tricaleium phosphate scaffold in alveolar ridge preservation with Bio-Oss Collagen

    Science.gov (United States)

    Wang, Tong; Li, Qing; Zhang, Gui-feng; Zhou, Gang; Yu, Xin; Zhang, Jing; Wang, Xiu-mei; Tang, Zhi-hui

    2016-06-01

    Bone scaffolds are critical in current implant and periodontal regeneration approaches. In this study, we prepared a novel composite type-I collagen and hydroxyapatite (HA)/β-tricaleium phosphate (TCP) scaffold (CHTS) by incorporating type-I collagen and bovine calcined bone granules, prepared as a mixture of 50% HA and 50% TCP, by freeze drying. We then characterized the CHTS and determined its cytotoxic effects. Additionally, ridge preservation experiments were carried out to evaluate the clinical effects of the CHTS. The results demonstrated that the composite scaffolds had good surface morphology and no cytotoxicity. Additionally, an in vivo experiment in an animal model showed that the CHTS performed equally as well as Bio-Oss Collagen, a widely used bone graft in ridge preservation. These findings revealed that the CHTS, which contained natural constituents of bone, could be used as a scaffold for bone regeneration and clinical use.

  17. Complex Determinants in Specific Members of the Mannose Receptor Family Govern Collagen Endocytosis

    DEFF Research Database (Denmark)

    Jürgensen, Henrik J; Johansson, Kristina; Madsen, Daniel H

    2014-01-01

    Members of the well-conserved mannose receptor (MR) protein family have been functionally implicated in diverse biological and pathological processes. Importantly, a proposed common function is the internalization of collagen for intracellular degradation occurring during bone development, cancer...... invasion, and fibrosis protection. This functional relationship is suggested by a common endocytic capability and a candidate collagen-binding domain. Here we conducted a comparative investigation of each member's ability to facilitate intracellular collagen degradation. As expected, the family members u......PARAP/Endo180 and MR bound collagens in a purified system and internalized collagens for degradation in cellular settings. In contrast, the remaining family members, PLA2R and DEC-205, showed no collagen binding activity and were unable to mediate collagen internalization. To pinpoint the structural elements...

  18. The digestion of phagocytosed collagen is inhibited by the proteinase inhibitors leupeptin and E-64

    NARCIS (Netherlands)

    Everts, V.; Beertsen, W.; Tigchelaar-Gutter, W.

    1985-01-01

    Using morphometric methods the effects of the thiol-proteinase inhibitors leupeptin and E-64 on the digestion of intracytoplasmic collagen fibrils were studied in cultured mouse bone explants. Both drugs caused a dose-dependent increase of lysosomal structures containing cross-banded collagen

  19. Iron nanoparticles from blood coated with collagen as a matrix for ...

    Indian Academy of Sciences (India)

    Keywords. Collagen; iron nanoparticle; nanohydroxyapatite; MTT assay; wet precipitation method. 1. Introduction. Bone is a type of connective tissue mainly composed of an organic component, collagen and an inorganic component, nanocrystalline carbonate hydroxyapatite. This type of bio- logical hybrid material finds ...

  20. Collagen metabolism in obesity

    DEFF Research Database (Denmark)

    Rasmussen, M H; Jensen, L T; Andersen, T

    1995-01-01

    OBJECTIVE: To investigate the impact of obesity, fat distribution and weight loss on collagen turnover using serum concentrations of the carboxyterminal propeptide of type I procollagen (S-PICP) and the aminoterminal propeptide of type III pro-collagen (S-PIIINP) as markers for collagen turnover...... (r = 0.37; P = 0.004), height (r = 0.27; P = 0.04), waist circumference (r = 0.35; P = 0.007), as well as with WHR (r = 0.33; P = 0.01) and was inversely correlated to age (r = -0.40; P = 0.002). Compared with randomly selected controls from a large pool of healthy volunteers, the obese patients had...... restriction (P obesity and associated with body fat distribution, suggesting...

  1. Clinical evaluation of the Serum CrossLaps One Step ELISA, a new assay measuring the serum concentration of bone-derived degradation products of type I collagen C-telopeptides

    DEFF Research Database (Denmark)

    Christgau, S; Rosenquist, C; Alexandersen, P

    1998-01-01

    The Serum CrossLaps One Step ELISA is a sandwich assay using two monoclonal antibodies specific for a beta-aspartate form of the epitope EKAHDGGR derived from the carboxy-terminal telopeptide region of type I collagen alpha1-chain. Our objective was to assess the clinical value of the Serum Cross...

  2. Osmotic pressure induced tensile forces in tendon collagen

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J.; Fratzl, Peter

    2015-01-01

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  3. Collagenous Tissues upon Lithium Treatment: A Quantitative Ultrastructural Study

    Directory of Open Access Journals (Sweden)

    Margaret Tzaphlidou

    2004-01-01

    Full Text Available In this review, the influence of lithium treatment in mouse, rat, and rabbit skin, liver, bone, and aorta, as well as arachnoid and dura mater collagen fibrils, is examined using electron microscopy and image processing. Structural changes (fibril architecture and diameter are detected at the ultrastructural level in specimens from all lithium-treated tissues. The overall collagen fibril architecture is disturbed as compared with specimens from normal species. The mean diameter values of treated collagen fibrils are significantly smaller than those from controls in all tissues examined. The banding patterns of fibrils are normal in all cases. Measurements by a computerized method of measuring axial periodicity of fibrils indicate no effect of lithium on this parameter. Computer analysis shows no differences in charged amino acid composition between lithium-treated and -untreated samples. Under the present experimental conditions, lithium can induce permanent structural collagen alterations.

  4. Osmotic pressure induced tensile forces in tendon collagen.

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J; Fratzl, Peter

    2015-01-22

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  5. Non-linearity of the collagen triple helix in solution and implications for collagen function.

    Science.gov (United States)

    Walker, Kenneth T; Nan, Ruodan; Wright, David W; Gor, Jayesh; Bishop, Anthony C; Makhatadze, George I; Brodsky, Barbara; Perkins, Stephen J

    2017-06-16

    Collagen adopts a characteristic supercoiled triple helical conformation which requires a repeating (Xaa-Yaa-Gly) n sequence. Despite the abundance of collagen, a combined experimental and atomistic modelling approach has not so far quantitated the degree of flexibility seen experimentally in the solution structures of collagen triple helices. To address this question, we report an experimental study on the flexibility of varying lengths of collagen triple helical peptides, composed of six, eight, ten and twelve repeats of the most stable Pro-Hyp-Gly (POG) units. In addition, one unblocked peptide, (POG) 10unblocked , was compared with the blocked (POG) 10 as a control for the significance of end effects. Complementary analytical ultracentrifugation and synchrotron small angle X-ray scattering data showed that the conformations of the longer triple helical peptides were not well explained by a linear structure derived from crystallography. To interpret these data, molecular dynamics simulations were used to generate 50 000 physically realistic collagen structures for each of the helices. These structures were fitted against their respective scattering data to reveal the best fitting structures from this large ensemble of possible helix structures. This curve fitting confirmed a small degree of non-linearity to exist in these best fit triple helices, with the degree of bending approximated as 4-17° from linearity. Our results open the way for further studies of other collagen triple helices with different sequences and stabilities in order to clarify the role of molecular rigidity and flexibility in collagen extracellular and immune function and disease. © 2017 The Author(s).

  6. Bone Activity Biomarkers and Bone Mineral Density in Children with ...

    African Journals Online (AJOL)

    Participants were subjected to biochemical assessment that included osteocalcin (OC), total and bone-specific alkaline phosphatase (tALP and bALP), isomerized beta form of type I collagen cross-linked telopeptide (β-Crosslaps) and intact parathyroid hormone (iPTH) levels. Patients with CKD also had their bone mineral ...

  7. Cancer risk in collagenous colitis

    NARCIS (Netherlands)

    Chan, J. L.; Tersmette, A. C.; Offerhaus, G. J.; Gruber, S. B.; Bayless, T. M.; Giardiello, F. M.

    1999-01-01

    Collagenous colitis is a recently described form of chronic inflammatory bowel disease. Other inflammatory bowel disorders are associated with increased risk of colorectal and extracolonic malignancies, but this has not been evaluated in collagenous colitis. Colorectal and extracolonic malignancies

  8. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...... after 2 weeks in the diaphyseal fractures and after 6 weeks in the condylar fractures. The degradation of type I collagen increased after 4 days and reached a maximum at 2 weeks in both groups. The interindividual variation was wide. On a group basis, the turnover of types I and III collagen had...

  9. Innovative biodegradable poly(L-lactide/collagen/hydroxyapatite composite fibrous scaffolds promote osteoblastic proliferation and differentiation

    Directory of Open Access Journals (Sweden)

    Zhou GQ

    2017-10-01

    Full Text Available Guoqiang Zhou,1–3 Sudan Liu,1 Yanyan Ma,1 Wenshi Xu,1 Wei Meng,1 Xue Lin,1 Wenying Wang,1,3 Shuxiang Wang,1–3 Jinchao Zhang1–3 1College of Chemistry and Environmental Science, 2Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of Ministry of Education, 3Key Laboratory of Chemical Biology of Hebei Province, Hebei University, Baoding, Hebei, People’s Republic of China Abstract: The development of an artificial bone graft which can promote the regeneration of fractures or diseased bones is currently the most challenging aspect in bone tissue engineering. To achieve the purpose of promoting bone proliferation and differentiation, the artificial graft needs have a similar structure and composition of extracellular matrix. One-step electrospinning method of biocomposite nanofibers containing hydroxyapatite (HA nanoparticles and collagen (Coll were developed for potential application in bone tissue engineering. Nanocomposite scaffolds of poly(L-lactide (PLLA, PLLA/HA, PLLA/Coll, and PLLA/Coll/HA were fabricated by electrospinning. The morphology, diameter, elements, hydrophilicity, and biodegradability of the composite scaffolds have been investigated. The biocompatibility of different nanocomposite scaffolds was assessed using mouse osteoblasts MC3T3-E1 in vitro, and the proliferation, differentiation, and mineralization of cells on different nanofibrous scaffolds were investigated. The results showed that PLLA/Coll/HA nanofiber scaffolds enhanced cell adhesion, spreading, proliferation, differentiation, mineralization, and gene expression of osteogenic markers compared to other scaffolds. In addition, the nanofibrous scaffolds maintained a stable composition at the beginning of the degradation period and morphology wastage and weight loss were observed when incubated for up to 80 days in physiological simulated conditions. The PLLA/Coll/HA composite nanofibrous scaffolds could be a potential material for guided bone regeneration

  10. Quantifying inter-laboratory variability in stable isotope analysis of ancient skeletal remains.

    Science.gov (United States)

    Pestle, William J; Crowley, Brooke E; Weirauch, Matthew T

    2014-01-01

    Over the past forty years, stable isotope analysis of bone (and tooth) collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond), the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a) sample preparation, and b) analysis (instrumentation, working standards, and data calibration). Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration). These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite isotope values

  11. Quantifying inter-laboratory variability in stable isotope analysis of ancient skeletal remains.

    Directory of Open Access Journals (Sweden)

    William J Pestle

    Full Text Available Over the past forty years, stable isotope analysis of bone (and tooth collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond, the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a sample preparation, and b analysis (instrumentation, working standards, and data calibration. Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration. These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite

  12. The collagen microfibil model as a tool for leather scientists

    Science.gov (United States)

    Collagen, a structural protein of the extracellular matrix, gives strength and form to the skin, tendons, bones, cornea and teeth of mammals. The discovery by early humans that the skin of an animal, slaughtered for meat, could be preserved by exposing it to smoke or rubbing with fat, led to the pr...

  13. Collagen-lactoferrin fibrillar coatings enhance osteoblast proliferation and differentiation

    Czech Academy of Sciences Publication Activity Database

    Vandrovcová, Marta; Douglas, T.E.L.; Heinemann, S.; Scharnweber, D.; Dubruel, P.; Bačáková, Lucie

    2015-01-01

    Roč. 103, č. 2 (2015), s. 525-533 ISSN 1549-3296 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : lactoferin * collagen * bone cells Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.263, year: 2015

  14. Cell-instructive starPEG-heparin-collagen composite matrices.

    Science.gov (United States)

    Binner, Marcus; Bray, Laura J; Friedrichs, Jens; Freudenberg, Uwe; Tsurkan, Mikhail V; Werner, Carsten

    2017-04-15

    Polymer hydrogels can be readily modulated with regard to their physical properties and functionalized to recapitulate molecular cues of the extracellular matrix (ECM). However, they remain structurally different from the hierarchical supramolecular assemblies of natural ECM. Accordingly, we herein report a set of hydrogel composite materials made from starPEG-peptide conjugates, maleimide-functionalized heparin and collagen type I that combine semisynthetic and ECM-derived components. Collagen fibrillogenesis was controlled by temperature and collagen concentration to form collagen microstructures which were then homogeneously distributed within the 3D composite matrix during hydrogel formation. The collagen-laden hydrogel materials showed a heterogeneous local variation of the stiffness and adhesion ligand density. Composite gels functionalized with growth factors and cell adhesive peptides (RGDSP) supported the growth of embedded human umbilical cord vein endothelial cells (HUVECs) and induced the alignment of embedded bone marrow-derived human mesenchymal stem cells (MSCs) to the collagen microstructures in vitro. The introduced composite hydrogel material is concluded to faithfully mimic cell-instructive features of the ECM. Cell-instructive materials play an important role in the generation of both regenerative therapies and advanced tissue and disease models. For that purpose, biofunctional polymer hydrogels recapitulating molecular cues of the extracellular matrix (ECM) were successfully applied in various different studies. However, hydrogels generally lack the hierarchical supramolecular structure of natural ECM. We have therefore developed a hydrogel composite material made from starPEG-peptide conjugates, maleimide-functionalized heparin and collagen type I fibrils. The collagen-laden scaffolds showed a heterogeneous local variation in the stiffness of the material. The composite gels were successfully tested in culture experiments with human umbilical

  15. Genetic disorders of collagen.

    OpenAIRE

    Tsipouras, P; Ramirez, F

    1987-01-01

    Osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan syndrome form a group of genetic disorders of connective tissue. These disorders exhibit remarkable clinical heterogeneity which reflects their underlying biochemical and molecular differences. Defects in collagen types I and III have been found in all three syndromes.

  16. Rheology of Heterotypic Collagen Networks

    NARCIS (Netherlands)

    Piechocka, I.K.; van Oosten, A.S.G.; Breuls, R.G.M.; Koenderink, G.H.

    2011-01-01

    Collagen fibrils are the main structural element of connective tissues. In many tissues, these fibrils contain two fibrillar collagens (types I and V) in a ratio that changes during tissue development, regeneration, and various diseases. Here we investigate the influence of collagen composition on

  17. Establishment of an osteogenic cell line derived from adult mouse bone marrow stroma by use of a recombinant retrovirus.

    Science.gov (United States)

    Mathieu, E; Schoeters, G; vander Plaetse, F; Merregaert, J

    1992-04-01

    In order to characterize fibroblastic colony-forming units (CFU-F) from murine bone marrow in relation to osteogenesis, adherent cells of 7-day-old BALB/c mouse bone marrow cultures were infected with a recombinant retrovirus (N2/ delta fosB) containing the bacterial neomycin resistance gene. One of the G418-resistant clones, MN7, was selected for further analysis on the basis of its high expression of the bone-specific alkaline phosphatase. The cells have now been in culture for more than 1 year and maintain a stable phenotype. The osteogenic nature of the immortalized clone MN7 was demonstrated as follows: (1) Mineralization was detected by 85Sr uptake and with the Von Kossa staining method only after in vitro cultivation on a collagen type I matrix. (2) Osteoblastic phenotype markers, including the synthesis of type I collagen, osteonectin, and the bone-specific isoenzyme of alkaline phosphatase were expressed in vitro. (3) MN7 cells responded to bone effectors such as parathyroid hormone and 1,25-dihydroxyvitamin D3. (4) Intraperitoneal injection of MN7 cells into 1-day-old BALB/c mice produced typical osteosarcomas in all animals. We conclude that MN7, derived entirely in vitro from a stromal CFU-F colony, represents a stable murine osteosarcoma cell line expressing the osteoblastic phenotype and provides the first direct evidence needed to establish adult mouse marrow-derived, nonhematopoietic stromal cells as osteoprogenitors.

  18. Saos-2 cell-mediated mineralization on collagen gels: Effect of densification and bioglass incorporation.

    Science.gov (United States)

    Liu, Gengbo; Pastakia, Meet; Fenn, Michael B; Kishore, Vipuil

    2016-05-01

    Plastic compression is a collagen densification process that has been widely used for the development of mechanically robust collagen-based materials. Incorporation of bioglass within plastically compressed collagen gels has been shown to mimic the microstructural properties of native bone and enhance in vitro cell-mediated mineralization. The current study seeks to decouple the effects of collagen densification and bioglass incorporation to understand the interplay between collagen packing density and presence of bioglass on cell-mediated mineralization. Saos-2 cell-mediated mineralization was assessed as a measure of the osteoconductivity of four different collagen gels: (1) uncompressed collagen gel (UC), (2) bioglass incorporated uncompressed collagen gel (UC + BG), (3) plastically compressed collagen gel (PC), and (4) bioglass incorporated plastically compressed collagen gel (PC + BG). The results indicated that collagen densification enhanced mineralization as shown by SEM, increased alkaline phosphatase activity and produced significantly higher amounts of mineralized nodules on PC gels compared to UC gels. Further, the amount of nodule formation on PC gels was significantly higher compared to UC + BG gels indicating that increase in matrix stiffness due to collagen densification had a greater effect on cell-mediated mineralization compared to bioglass incorporation into loosely packed UC gels. Incorporation of bioglass into PC gels further enhanced mineralization as evidenced by significantly larger nodule size and higher amount of mineralization on PC + BG gels compared to PC gels. In conclusion, collagen densification via plastic compression improves the osteoconductivity of collagen gels. Further, incorporation of bioglass within PC gels has an additive effect and further enhances the osteoconductivity of collagen gels. © 2016 Wiley Periodicals, Inc.

  19. Biphasic Scaffolds from Marine Collagens for Regeneration of Osteochondral Defects

    Directory of Open Access Journals (Sweden)

    Anne Bernhardt

    2018-03-01

    Full Text Available Background: Collagens of marine origin are applied increasingly as alternatives to mammalian collagens in tissue engineering. The aim of the present study was to develop a biphasic scaffold from exclusively marine collagens supporting both osteogenic and chondrogenic differentiation and to find a suitable setup for in vitro chondrogenic and osteogenic differentiation of human mesenchymal stroma cells (hMSC. Methods: Biphasic scaffolds from biomimetically mineralized salmon collagen and fibrillized jellyfish collagen were fabricated by joint freeze-drying and crosslinking. Different experiments were performed to analyze the influence of cell density and TGF-β on osteogenic differentiation of the cells in the scaffolds. Gene expression analysis and analysis of cartilage extracellular matrix components were performed and activity of alkaline phosphatase was determined. Furthermore, histological sections of differentiated cells in the biphasic scaffolds were analyzed. Results: Stable biphasic scaffolds from two different marine collagens were prepared. An in vitro setup for osteochondral differentiation was developed involving (1 different seeding densities in the phases; (2 additional application of alginate hydrogel in the chondral part; (3 pre-differentiation and sequential seeding of the scaffolds and (4 osteochondral medium. Spatially separated osteogenic and chondrogenic differentiation of hMSC was achieved in this setup, while osteochondral medium in combination with the biphasic scaffolds alone was not sufficient to reach this ambition. Conclusions: Biphasic, but monolithic scaffolds from exclusively marine collagens are suitable for the development of osteochondral constructs.

  20. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture....... The markers were the carboxy-terminal extension peptide of type I procollagen (PICP), the amino-terminal extension peptide of type III procollagen (PIIINP), and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP). The latter is a new serum marker of degradation of type I...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...

  1. Biomimetics of Bone Implants: The Regenerative Road

    Directory of Open Access Journals (Sweden)

    Elizabeth Brett

    2017-01-01

    Full Text Available The current strategies for healing bone defects are numerous and varied. At the core of each bone healing therapy is a biomimetic mechanism, which works to enhance bone growth. These range from porous scaffolds, bone mineral usage, collagen, and glycosaminoglycan substitutes to transplanted cell populations. Bone defects face a range of difficulty in their healing, given the composite of dense outer compact bone and blood-rich inner trabecular bone. As such, the tissue possesses a number of inherent characteristics, which may be clinically harnessed as promoters of bone healing. These include mechanical characteristics, mineral composition, native collagen content, and cellular fraction of bone. This review charts multiple biomimetic strategies to help heal bony defects in large and small osseous injury sites, with a special focus on cell transplantation.

  2. Development and optimization of a high-throughput micro-computed tomography imaging method incorporating a novel analysis technique to evaluate bone mineral density of arthritic joints in a rodent model of collagen induced arthritis.

    Science.gov (United States)

    Sevilla, Raquel S; Cruz, Francisco; Chiu, Chi-Sung; Xue, Dahai; Bettano, Kimberly A; Zhu, Joe; Chakravarthy, Kalyan; Faltus, Robert; Wang, Shubing; Vanko, Amy; Robinson, Gain; Zielstorff, Mark; Miao, John; Leccese, Erica; Conway, Donald; Moy, Lily Y; Dogdas, Belma; Cicmil, Milenko; Zhang, Weisheng

    2015-04-01

    Rheumatoid arthritis (RA) is a chronic autoimmune disease resulting in joint inflammation, pain, and eventual bone loss. Bone loss and remodeling caused by symmetric polyarthritis, the hallmark of RA, is readily detectable by bone mineral density (BMD) measurement using micro-CT. Abnormalities in these measurements over time reflect the underlying pathophysiology of the bone. To evaluate the efficacy of anti-rheumatic agents in animal models of arthritis, we developed a high throughput knee and ankle joint imaging assay to measure BMD as a translational biomarker. A bone sample holder was custom designed for micro-CT scanning, which significantly increased assay throughput. Batch processing 3-dimensional image reconstruction, followed by automated image cropping, significantly reduced image processing time. In addition, we developed a novel, automated image analysis method to measure BMD and bone volume of knee and ankle joints. These improvements significantly increased the throughput of ex vivo bone sample analysis, reducing data turnaround from 5 days to 24 hours for a study with 200 rat hind limbs. Taken together, our data demonstrate that BMD, as quantified by micro-CT, is a robust efficacy biomarker with a high degree of sensitivity. Our innovative approach toward evaluation of BMD using optimized image acquisition and novel image processing techniques in preclinical models of RA enables high throughput assessment of anti-rheumatic agents offering a powerful tool for drug discovery. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Changes in Structural-Mechanical Properties and Degradability of Collagen during Aging-associated Modifications.

    Science.gov (United States)

    Panwar, Preety; Lamour, Guillaume; Mackenzie, Neil C W; Yang, Heejae; Ko, Frank; Li, Hongbin; Brömme, Dieter

    2015-09-18

    During aging, changes occur in the collagen network that contribute to various pathological phenotypes in the skeletal, vascular, and pulmonary systems. The aim of this study was to investigate the consequences of age-related modifications on the mechanical stability and in vitro proteolytic degradation of type I collagen. Analyzing mouse tail and bovine bone collagen, we found that collagen at both fibril and fiber levels varies in rigidity and Young's modulus due to different physiological changes, which correlate with changes in cathepsin K (CatK)-mediated degradation. A decreased susceptibility to CatK-mediated hydrolysis of fibrillar collagen was observed following mineralization and advanced glycation end product-associated modification. However, aging of bone increased CatK-mediated osteoclastic resorption by ∼27%, and negligible resorption was observed when osteoclasts were cultured on mineral-deficient bone. We observed significant differences in the excavations generated by osteoclasts and C-terminal telopeptide release during bone resorption under distinct conditions. Our data indicate that modification of collagen compromises its biomechanical integrity and affects CatK-mediated degradation both in bone and tissue, thus contributing to our understanding of extracellular matrix aging. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Collagen-like proteins in pathogenic E. coli strains.

    Directory of Open Access Journals (Sweden)

    Neelanjana Ghosh

    Full Text Available The genome sequences of enterohaemorrhagic E. coli O157:H7 strains show multiple open-reading frames with collagen-like sequences that are absent from the common laboratory strain K-12. These putative collagens are included in prophages embedded in O157:H7 genomes. These prophages carry numerous genes related to strain virulence and have been shown to be inducible and capable of disseminating virulence factors by horizontal gene transfer. We have cloned two collagen-like proteins from E. coli O157:H7 into a laboratory strain and analysed the structure and conformation of the recombinant proteins and several of their constituting domains by a variety of spectroscopic, biophysical, and electron microscopy techniques. We show that these molecules exhibit many of the characteristics of vertebrate collagens, including trimer formation and the presence of a collagen triple helical domain. They also contain a C-terminal trimerization domain, and a trimeric α-helical coiled-coil domain with an unusual amino acid sequence almost completely lacking leucine, valine or isoleucine residues. Intriguingly, these molecules show high thermal stability, with the collagen domain being more stable than those of vertebrate fibrillar collagens, which are much longer and post-translationally modified. Under the electron microscope, collagen-like proteins from E. coli O157:H7 show a dumbbell shape, with two globular domains joined by a hinged stalk. This morphology is consistent with their likely role as trimeric phage side-tail proteins that participate in the attachment of phage particles to E. coli target cells, either directly or through assembly with other phage tail proteins. Thus, collagen-like proteins in enterohaemorrhagic E. coli genomes may have a direct role in the dissemination of virulence-related genes through infection of harmless strains by induced bacteriophages.

  5. Bone mineral and other bone components in vertebrae evaluated by QCT and MRI

    International Nuclear Information System (INIS)

    Ito, Masako; Hayashi, Kuniaki; Uetani, Masataka; Kawahara, Yasuhiro; Ohki, Masafumi; Yamada, Miho; Kitamori, Hideki; Noguchi, Masaru; Ito, Masahiro

    1993-01-01

    To evaluate the usefulness of assessing bone components using magnetic resonance imaging (MRI), the contributions of bone components, including mineral, fat and collagen, to bone mineral density (BMD) and T1 relaxation time (T1) were studied using phantoms. Excised human vertebrae were also evaluated by quantitative computed tomography (QCT) and MRI. T1 was shortened with increasing quantities of fat and collagen. In water, T1 was significantly affected by bone density, while in oil, T1 became slightly longer as bone density increased . The presence of fat and collagen caused under-and overestimations of BMD, respectively. There was good correlation between T1 and BMD in osteoporotic vertebrae and the vertebrae with long T1 showed an increased content of hematopoietic marrow and/or abnormally increased bone mineral. It was concluded that the experimental data showed that MRI can contribute to the assessment of bone quality. (orig.)

  6. Bone Remodelling Markers in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Patrice Fardellone

    2014-01-01

    Full Text Available Bone loss in rheumatoid arthritis (RA patients results from chronic inflammation and can lead to osteoporosis and fractures. A few bone remodeling markers have been studied in RA witnessing bone formation (osteocalcin, serum aminoterminal propeptide of type I collagen (PINP, serum carboxyterminal propeptide of type I collagen (ICTP, bone alkaline phosphatase (BAP, osteocalcin (OC, and bone resorption: C-terminal telopeptide of type 1 collagen (I-CTX, N-terminal telopeptide of type 1 collagen (I-NTX, pyridinolines (DPD and PYD, and tartrate-resistant acid phosphatase (TRAP. Bone resorption can be seen either in periarticular bone (demineralization and erosion or in the total skeleton (osteoporosis. Whatever the location, bone resorption results from activation of osteoclasts when the ratio between osteoprotegerin and receptor activator of nuclear factor kappa-B ligand (OPG/RANKL is decreased under influence of various proinflammatory cytokines. Bone remodeling markers also allow physicians to evaluate the effect of drugs used in RA like biologic agents, which reduce inflammation and exert a protecting effect on bone. We will discuss in this review changes in bone markers remodeling in patients with RA treated with biologics.

  7. The Pd (0) nanoparticles stabilized by collagen fibres as a ...

    Indian Academy of Sciences (India)

    The stabilized palladium(0) nanoparticles by collagen fibres was a highly active, air-stable and recyclable heterogeneous catalyst that could be used for the Stille coupling reactions between aryl iodides and organostannanes under aerobic conditions. This method offered the several advantages: high yield under facile ...

  8. [Bone Cell Biology Assessed by Microscopic Approach. The effects of active vitamin D3 such as alfacalcidol and eldecalcitol on bone quality].

    Science.gov (United States)

    Saito, Mitsuru; Marumo, Keishi

    2015-10-01

    Active vitamin D3 is used for the treatment for osteoporosis in Japan. Recently, data have accumulated that collagen cross-link formation in bone affect bone strength. In fact, impaired enzymatic cross-linking, over-hydroxylation of crosslinks, and an increase in non-enzymatic crosslinking advanced glycation end products (AGEs) such as pentosidine, in bone collagen have been proposed as a major cause of bone fragility in osteoporosis. We reported that alfacalcidol and eldecalcitol improves bone material properties such as collagen cross-link formation, microarchitecture, and microcrack resulting in the increase of bone strength (Saito M, Bone 2010;46:1170-1179, Calcif Tissue Int 2011;88:314-324, Bone, 2015;73:8-15). In this review, we described how active vitamin D3 improve bone collagen cross-link formation and mineral qualities.

  9. Collagen Type I as a Ligand for Receptor-Mediated Signaling

    Directory of Open Access Journals (Sweden)

    Iris Boraschi-Diaz

    2017-05-01

    Full Text Available Collagens form the fibrous component of the extracellular matrix in all multi-cellular animals. Collagen type I is the most abundant collagen present in skin, tendons, vasculature, as well as the organic portion of the calcified tissue of bone and teeth. This review focuses on numerous receptors for which collagen acts as a ligand, including integrins, discoidin domain receptors DDR1 and 2, OSCAR, GPVI, G6b-B, and LAIR-1 of the leukocyte receptor complex (LRC and mannose family receptor uPARAP/Endo180. We explore the process of collagen production and self-assembly, as well as its degradation by collagenases and gelatinases in order to predict potential temporal and spatial sites of action of different collagen receptors. While the interactions of the mature collagen matrix with integrins and DDR are well-appreciated, potential signals from immature matrix as well as collagen degradation products are possible but not yet described. The role of multiple collagen receptors in physiological processes and their contribution to pathophysiology of diseases affecting collagen homeostasis require further studies.

  10. Collagen type I as a ligand for receptor-mediated signaling

    Science.gov (United States)

    Boraschi-Diaz, Iris; Wang, Jennifer; Mort, John S.; Komarova, Svetlana V.

    2017-05-01

    Collagens form the fibrous component of the extracellular matrix in all multi-cellular animals. Collagen type I is the most abundant collagen present in skin, tendons, vasculature, as well as the organic portion of the calcified tissue of bone and teeth. This review focuses on numerous receptors for which collagen acts as a ligand, including integrins, discoidin domain receptors DDR1 and 2, OSCAR, GPVI, G6b-B and Lair-1 of the leukocyte receptor complex and mannose family receptor uPARAP/Endo 180. We explore the process of collagen production and self-assembly, as well as its degradation by collagenases and gelatinases in order to predict potential temporal and spatial sites of action of different collagen receptors. While the interactions of the mature collagen matrix with integrins and DDR are well-appreciated, potential signals from immature matrix as well as collagen degradation products are possible but not yet described. The role of multiple collagen receptors in physiological processes and their contribution to pathophysiology of diseases affecting collagen homeostasis require further studies.

  11. Collagen macromolecular drug delivery systems

    International Nuclear Information System (INIS)

    Gilbert, D.L.

    1988-01-01

    The objective of this study was to examine collagen for use as a macromolecular drug delivery system by determining the mechanism of release through a matrix. Collagen membranes varying in porosity, crosslinking density, structure and crosslinker were fabricated. Collagen characterized by infrared spectroscopy and solution viscosity was determined to be pure and native. The collagen membranes were determined to possess native vs. non-native quaternary structure and porous vs. dense aggregate membranes by electron microscopy. Collagen monolithic devices containing a model macromolecule (inulin) were fabricated. In vitro release rates were found to be linear with respect to t 1/2 and were affected by crosslinking density, crosslinker and structure. The biodegradation of the collagen matrix was also examined. In vivo biocompatibility, degradation and 14 C-inulin release rates were evaluated subcutaneously in rats

  12. Bioactivity And Bone Formation In Silicon-Substituted Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Ulvan Ozad

    2012-06-01

    Full Text Available Bioactivity and successful bone formation in silicon-substituted hydroxyapatite bone grafts were investigated by using scanning electron microscopy and electron dispersive x-ray spectroscopy. Areas of bone formation have been detected in scanning electron microscopy; and, arranged lamellar collagen has been observed. 20.8% average carbon content rise has been detected between bone graft and the produced bone; and, this has been confirmed to be a gradual increase throughout the interphase. Obvious bone formation and maturation were observed in the samples. Carbon content gradually increased from bone graft to the bone formed, confirming formation of new bone and dissociation of silicon-substituted bone graft.

  13. Chemical Stabilisation of Collagen as a Biomimetic

    Directory of Open Access Journals (Sweden)

    R. Gordon Paul

    2003-01-01

    Full Text Available Collagen is the most abundant protein in animals and because of its high mechanical strength and good resistance to degradation has been utilized in a wide range of products in industry whilst its low antigenicity has resulted in its widespread use in medicine. Collagen products can be purified from fibres, molecules reconstituted as fibres or from specific recombinant polypeptides with preferred properties. A common feature of all these biomaterials is the need for stable chemical cross-linking to control the mechanical properties and the residence time in the body, and to some extent the immunogenicity of the device. This can be achieved by a number of different cross-linking agents that react with specific amino acid residues on the collagen molecule imparting individual biochemical, thermal and mechanical characteristics to the biomaterial. In this review we have summarised the major techniques for testing these characteristics and the mechanisms involved in the variety of cross-linking reactions to achieve particular properties..

  14. Reevaluation of the role of the polar groups of collagen in the platelet-collagen interaction.

    OpenAIRE

    Chesney, C. M.; Pifer, D. D.; Crofford, L. J.; Huch, K. M.

    1983-01-01

    Chemical modification of collagen is a tool for exploring the platelet-collagen interaction. Since collagen must polymerize prior to the initiation of platelet aggregation and secretion, modification must be shown to affect platelet-collagen interaction and not collagen-collagen interaction. To address this point, the authors carried out the following chemical modifications on soluble monomeric collagen and preformed fibrillar collagen in parallel: 1) N-and O-acetylation, 2) esterification of...

  15. Exploration of collagen recovered from animal by-products as a precursor of bioactive peptides: Successes and challenges.

    Science.gov (United States)

    Fu, Yu; Therkildsen, Margrethe; Aluko, Rotimi E; Lametsch, René

    2018-02-02

    A large amount of food-grade animal by-products is annually produced during industrial processing and they are normally utilized as animal feed or other low-value purposes. These by-products are good sources of valuable proteins, including collagen or gelatin. The revalorization of collagen may lead to development of a high benefit-to-cost ratio. In this review, the major approaches for generation of collagen peptides with a wide variety of bioactivities were summarized, including antihypertensive, antioxidant and antidiabetic activities, and beneficial effects on bone, joint and skin health. The biological potentials of collagen peptides and their bioavailability were reviewed. Moreover, the unique advantages of collagen peptides over other therapeutic peptides were highlighted. In addition, the current challenges for development of collagen peptides as functional food ingredients were also discussed. This article discusses the opportunity to utilize collagen peptides as high value-added bio-functional ingredients in the food industry.

  16. The role of type X collagen in facilitating and regulating endochondral ossification of articular cartilage.

    Science.gov (United States)

    Shen, G

    2005-02-01

    AUTHOR: Shen G Objective -This review was compiled to explore the role of type X collagen in growth, development and remodeling of articular cartilage by elucidating the linkage between the synthesis of this protein and the phenotypic changes in chondrogenesis and the onset of endochondral ossification. The current studies closely dedicated to elucidating the role of type X collagen incorporating into chondrogenesis and endochondral ossification of articular cartilage were assessed and analyzed to allow for obtaining the mainstream consensus on the bio-molecular mechanism with which type X collagen functions in articular cartilage. There are spatial and temporal correlations between synthesis of type X collagen and occurrence of endochondral ossification. The expression of type X collagen is confined within hypertrophic condrocytes and precedes the embark of endochondral bone formation. Type X collagen facilitates endochondral ossification by regulating matrix mineralization and compartmentalizing matrix components. Type X collagen is a reliable marker for new bone formation in articular cartilage. The future clinical application of this collagen in inducing or mediating endochondral ossification is perceived, e.g. the fracture healing of synovial joints and adaptive remodeling of madibular condyle.

  17. [The influence of type I collagen on the cell behavior of human embryonic periosteous osteoblasts].

    Science.gov (United States)

    Yang, Z; Yu, X; Huang, F; Xie, H

    2001-03-01

    To study the influence of type I collagen (COL I) on the cell behavior of human periosteous osteoblasts (OB) and the application of type I collagen in constructing bioactive artifical bone. OB were cultured on dishes coated with bovine type I collagen in different final concentrations. The cell adhesion was examined by the methods of cell count, the proliferation of OB was studied by 3H-TdR, and the osteoblastic ability was assessed by the synthesis of collagen, osteocalcin and alkaline phosphatase (ALP). OB cultured on type I collagen layer had the following characteristics: 1. The amounts of adhesive cells were maximal top in 25 micrograms/ml final concentration; 2. The proliferation of OB was decreased above 12.5 micrograms/ml final concentration (P bone tissue engineering are coated with type I collagen, the osteogenesis of OB is enhanced to accelerate the transformation course from artificial bone to biological bone, the best final concentration is 25 micrograms/ml.

  18. The osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces in rats.

    Science.gov (United States)

    Kung, S; Devlin, H; Fu, E; Ho, K-Y; Liang, S-Y; Hsieh, Y-D

    2011-02-01

    The enhancing effects of chitosan on activation of platelets and differentiation of osteoprogenitor cells have been demonstrated in vitro. The purpose of this study was to evaluate the in vivo osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces. Chitosan-collagen composites containing chitosan of different molecular weights (450 and 750 kDa) were wrapped onto titanium implants and embedded into the subcutaneous area on the back of 15 Sprague-Dawley rats. The control consisted of implants wrapped with plain collagen type I membranes. Implants and surrounding tissues were retrieved 6 wks after surgery and identified by Alizarin red and Alcian blue whole mount staining. The newly formed structures in the test groups were further analyzed by Toluidine blue and Masson-Goldner trichrome staining, and immunohistochemical staining with osteopontin and alkaline phosphotase. The bone formation parameters of the new bone in the two test groups were measured and compared. New bone formed ectopically in both chitosan-collagen groups, whereas no bone induction occurred in the negative control group. These newly formed bone-like structures were further confirmed by immunohistochemical staining. Comparison of bone parameters of the newly induced bone revealed no statistically significant differences between the 450 and 750 kDa chitosan-collagen groups. Our results demonstrated that chitosan-collagen composites might induce in vivo new bone formation around pure titanium implant surfaces. Different molecular weights of chitosan did not show significantly different effects on the osteoinductive potential of the test materials. © 2010 John Wiley & Sons A/S.

  19. Clinical evaluation of the Serum CrossLaps One Step ELISA, a new assay measuring the serum concentration of bone-derived degradation products of type I collagen C-telopeptides

    DEFF Research Database (Denmark)

    Christgau, S; Rosenquist, C; Alexandersen, P

    1998-01-01

    The Serum CrossLaps One Step ELISA is a sandwich assay using two monoclonal antibodies specific for a beta-aspartate form of the epitope EKAHDGGR derived from the carboxy-terminal telopeptide region of type I collagen alpha1-chain. Our objective was to assess the clinical value of the Serum Cross......Laps assay for monitoring antiresorptive therapy in osteoporosis treatment. Samples obtained from postmenopausal women treated with different doses of cyclic or continuous hormone replacement therapy (HRT) with an estrogen analog (tibolone) or with a bisphosphonate (ibandronate) were measured in the Serum...... CrossLaps One Step ELISA at baseline and at various time points during therapy. The corresponding urine samples were measured in the urine CrossLaps ELISA and corrected for creatinine excretion. The serum CrossLaps measurements and corresponding urinary CrossLaps measurements were highly correlated (r...

  20. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  1. Human ciliary neurotrophic factor-overexpressing stable bone marrow stromal cells in the treatment of a rat model of traumatic spinal cord injury.

    Science.gov (United States)

    Abbaszadeh, Hojjat-Allah; Tiraihi, Taki; Noori-Zadeh, Ali; Delshad, Ali Reza; Sadeghizade, Majid; Taheri, Taher

    2015-07-01

    Traumatic injury to the central nervous system (CNS) often causes motor dysfunctions. However, because of the CNS complexity and variability in the clinical presentations, efforts to repair damaged CNS tissue and restoring its functions are particularly demanding. On the other hand, recent progress in the regenerative therapy field have led to novel approaches for the treatment of traumatic CNS injury and renewed hopes to overcome the obstacles. It appears that the balance between neurite re-growth-inhibiting and neurite re-growth-inducing molecules determines the axonal re-growth fate. Neurotrophic factors can tilt this balance and indeed promote cell survival and axonal re-growth over neurodegeneration. One of the promising neurotrophic factors in this field is ciliary neurotrophic factor (CNTF). We transfected rat bone marrow stromal cells with a mammalian expression vector-inserted human CNTF gene through the use of a non-viral method to prepare human CNTF-overexpressing stem cells under ex vivo conditions. We transplanted these modified cells to the rat model of spinal cord traumatic injury to explore functional recovery after contusion induction. Our data from immunocytochemistry and behavioral tests showed that such cells can act as a powerful potential approach to treat traumatic CNS injuries because these modified cells improved the behavioral test scores in the rat model of spinal cord injury. CNTF-overexpressing bone marrow stromal cells can ameliorate spinal cord traumatic injury and can be used in the treatment of traumatic CNS injuries in the near future. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  2. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  3. Collagen Conduit Versus Microsurgical Neurorrhaphy

    DEFF Research Database (Denmark)

    Boeckstyns, Michel; Sørensen, Allan Ibsen; Viñeta, Joaquin Fores

    2013-01-01

    To compare repair of acute lacerations of mixed sensory-motor nerves in humans using a collagen tube versus conventional repair.......To compare repair of acute lacerations of mixed sensory-motor nerves in humans using a collagen tube versus conventional repair....

  4. Combination of Root Surface Modification with BMP-2 and Collagen Hydrogel Scaffold Implantation for Periodontal Healing in Beagle Dogs

    OpenAIRE

    Kato, Akihito; Miyaji, Hirofumi; Ishizuka, Ryosuke; Tokunaga, Keisuke; Inoue, Kana; Kosen, Yuta; Yokoyama, Hiroyuki; Sugaya, Tsutomu; Tanaka, Saori; Sakagami, Ryuji; Kawanami, Masamitsu

    2015-01-01

    Objective : Biomodification of the root surface plays a major role in periodontal wound healing. Root surface modification with bone morphogenetic protein (BMP) stimulates bone and cementum-like tissue formation; however, severe ankylosis is simultaneously observed. Bio-safe collagen hydrogel scaffolds may therefore be useful for supplying periodontal ligament cells and preventing ankylosis. We examined the effects of BMP modification in conjunction with collagen hydrogel scaffold implantatio...

  5. Modelling the mechanics of partially mineralized collagen fibrils, fibres and tissue

    Science.gov (United States)

    Liu, Yanxin; Thomopoulos, Stavros; Chen, Changqing; Birman, Victor; Buehler, Markus J.; Genin, Guy M.

    2014-01-01

    Progressive stiffening of collagen tissue by bioapatite mineral is important physiologically, but the details of this stiffening are uncertain. Unresolved questions about the details of the accommodation of bioapatite within and upon collagen's hierarchical structure have posed a central hurdle, but recent microscopy data resolve several major questions. These data suggest how collagen accommodates bioapatite at the lowest relevant hierarchical level (collagen fibrils), and suggest several possibilities for the progressive accommodation of bioapatite at higher hierarchical length scales (fibres and tissue). We developed approximations for the stiffening of collagen across spatial hierarchies based upon these data, and connected models across hierarchies levels to estimate mineralization-dependent tissue-level mechanics. In the five possible sequences of mineralization studied, percolation of the bioapatite phase proved to be an important determinant of the degree of stiffening by bioapatite. The models were applied to study one important instance of partially mineralized tissue, which occurs at the attachment of tendon to bone. All sequences of mineralization considered reproduced experimental observations of a region of tissue between tendon and bone that is more compliant than either tendon or bone, but the size and nature of this region depended strongly upon the sequence of mineralization. These models and observations have implications for engineered tissue scaffolds at the attachment of tendon to bone, bone development and graded biomimetic attachment of dissimilar hierarchical materials in general. PMID:24352669

  6. Changes in Bone Alkaline Phosphatase and Procollagen Type-1 C-Peptide after Static and Dynamic Exercises

    Science.gov (United States)

    Kubo, Keitaro; Yuki, Kazuhito; Ikebukuro, Toshihiro

    2012-01-01

    We investigated the effects of two types of nonweight-bearing exercise on changes in bone-specific alkaline phosphatase (BAP) and pro-collagen type 1 C-peptide (P1P). BAP is a specific marker of bone synthesis, whereas P1P reflects synthesis of type 1 collagen in other organs as well as bone. Eight participants performed static and dynamic…

  7. Chitosan: collagen sponges. In vitro mineralization; Mineralizacao in vitro de esponjas de quitosana: colageno

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Virginia da C.A.; Silva, Gustavo M.; Plepis, Ana Maria G., E-mail: virginia@iqsc.usp.br [Instituto de Quimica de Sao Carlos- IQSC, Universidade de Sao Paulo, Sao Carlos, SP (Brazil)

    2011-07-01

    The regeneration of bone tissue is a problem that affects many people and scaffolds for bone tissue growth has been widely studied. The aim of this study was the in vitro mineralization of chitosan, chitosan:native collagen and chitosan:anionic collagen sponges. The sponges were obtained by lyophilization and mineralization was made by soaking the sponges in alternating solutions containing Ca{sup 2+} and PO{sub 4}{sup 3-}. The mineralization was confirmed by infrared spectroscopy, energy dispersive X-ray and X-ray diffraction observing the formation of phosphate salts, possibly a carbonated hydroxyapatite since Ca/P=1.80. The degree of mineralization was obtained by thermogravimetry calculating the amount of residue at 750 deg C. The chitosan:anionic collagen sponge showed the highest degree of mineralization probably due to the fact that anionic collagen provides additional sites for interaction with the inorganic phase. (author)

  8. Polymerized-Type I Collagen Induces Upregulation of Foxp3-Expressing CD4 Regulatory T Cells and Downregulation of IL-17-Producing CD4+ T Cells (Th17 Cells in Collagen-Induced Arthritis

    Directory of Open Access Journals (Sweden)

    Janette Furuzawa-Carballeda

    2012-01-01

    Full Text Available Previous studies showed that polymerized-type I collagen (polymerized collagen exhibits potent immunoregulatory properties. This work evaluated the effect of intramuscular administration of polymerized collagen in early and established collagen-induced arthritis (CIA in mice and analyzed changes in Th subsets following therapy. Incidence of CIA was of 100% in mice challenged with type II collagen. Clinimorphometric analysis showed a downregulation of inflammation after administration of all treatments (P<0.05. Histological analysis showed that the CIA-mice group had extensive bone erosion, pannus and severe focal inflammatory infiltrates. In contrast, there was a remarkable reduction in the severity of arthritis in mice under polymerized collagen, methotrexate or methotrexate/polymerized collagen treatment. Polymerized Collagen but not methotrexate induced tissue joint regeneration. Polymerized Collagen and methotrexate/polymerized collagen but not methotrexate alone induces downregulation of CD4+/IL17A+ T cells and upregulation of Tregs and CD4+/IFN-γ+ T cells. Thus, Polymerized Collagen could be an effective therapeutic agent in early and established rheumatoid arthritis by exerting downregulation of autoimmune inflammation.

  9. A Simple and Efficient Method to Improve Mechanical Properties of Collagen Scaffolds by UV Irradiation

    Directory of Open Access Journals (Sweden)

    F. Khayyatan

    2010-12-01

    Full Text Available Collagen is the major protein component of cartilage, bone, skin and connective tissue and constitutes the major part of the extracellular matrix. Collagen type I has complex structural hierarchy, which consists of treepolypeptide α-chains wound together in a rod-like helical structure. Collagen is an important biomaterial, finding many applications in the field of tissue engineering. It has been processed into various shapes, such as, gel, film, sponge and fiber. It is commonly used as the scaffolding material for tissue engineering due to its many superior properties including low antigenicity and high growth promotion. Unfortunately, poor mechanical properties and rapid degradation rates of collagen scaffolds can cause instability and difficulty in handling. By crosslinking, the structural stability of the collagen and its rate of resorption can be adapted with respect to its demanding requirements. The strength, resorption rate, and biocompatibility of collagenous biomaterials are profoundly influenced by the method and extent of crosslinking. In thisstudy, the effect of UV irradiation on collagen scaffolds has been carried out.Collagen scaffolds were fabricated using freeze drying method with freezing temperature of -80oC, then exposed to UV irradiation. Mean pore size of the scaffolds was obtained as 98.52±14.51 μm using scanning electron microscopy. Collagen scaffolds exposed to UV Irradiation (254 nm for 15 min showed the highest tensile strain (17.37±0.98 %, modulus (1.67±0.15 MPa and maximum load (24.47±2.38 cN values. As partial loss of the native collagen structure may influence attachment, migration, and proliferation of cells on collagen scaffolds, we detected no intact α-chains after SDS-Page chromatography. We demonstrate that UV irradiation is a rapid and easily controlled means of increasing the mechanical strength of collagen scaffolds without any molecular fracture.

  10. The roles of TGF-beta1 gene transfer on collagen formation during Achilles tendon healing.

    Science.gov (United States)

    Hou, Yu; Mao, ZeBing; Wei, XueLei; Lin, Lin; Chen, LianXu; Wang, HaiJun; Fu, Xin; Zhang, JiYing; Yu, ChangLong

    2009-05-29

    Collagen content and cross-linking are believed to be major determinants of tendon structural integrity and function. The current study aimed to investigate the effects of transforming growth factor (TGF)-beta1 on the collagen content and cross-linking of Achilles tendons, and on the histological and biomechanical changes occurring during Achilles tendon healing in rabbits. Bone marrow-derived mesenchymal stem cells (BMSCs) transfected with the TGF-beta1 gene were surgically implanted into experimentally injured Achilles tendons. Collagen proteins were identified by immunohistochemical staining and fiber bundle accumulation was revealed by Sirius red staining. Achilles tendons treated with TGF-beta1-transfected BMSCs showed higher concentrations of collagen I protein, more rapid matrix remodeling, and larger fiber bundles. Thus TGF-beta1 can promote mechanical strength in healing Achilles tendons by regulating collagen synthesis, cross-link formation, and matrix remodeling.

  11. Evaluation of epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes and concerns on osteoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Chenyu; Deng, Jia [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Xiang, Lin; Wu, Yingying [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Wei, Xiawei [State Key Laboratory of Biotherapy and Laboratory for Aging Research, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041 (China); Qu, Yili [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Man, Yi, E-mail: manyi780203@126.com [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China)

    2016-10-01

    Collagen membranes have ideal biological and mechanical properties for supporting infiltration and proliferation of osteoblasts and play a vital role in guided bone regeneration (GBR). However, pure collagen can lead to inflammation, resulting in progressive bone resorption. Therefore, a method for regulating the level of inflammatory cytokines at surgical sites is paramount for the healing process. Epigallocatechin-3-gallate (EGCG) is a component extracted from green tea with numerous biological activities including an anti-inflammatory effect. Herein, we present a novel cross-linked collagen membrane containing different concentrations of EGCG (0.0064%, 0.064%, and 0.64%) to regulate the level of inflammatory factors secreted by pre-osteoblast cells; improve cell proliferation; and increase the tensile strength, wettability, and thermal stability of collagen membranes. Scanning electron microscope images show that the surfaces of collagen membranes became smoother and the collagen fiber diameters became larger with EGCG treatment. Measurement of the water contact angle demonstrated that introducing EGCG improved membrane wettability. Fourier transform infrared spectroscopy analyses indicated that the backbone of collagen was intact, and the thermal stability was significant improved in differential scanning calorimetry. The mechanical properties of 0.064% and 0.64% EGCG-treated collagen membranes were 1.5-fold greater than those of the control. The extent of cross-linking was significantly increased, as determined by a 2,4,6-trinitrobenzenesulfonic acid solution assay. The Cell Counting Kit-8 (CCK-8) and live/dead assays revealed that collagen membrane cross-linked by 0.0064% EGCG induced greater cell proliferation than pure collagen membranes. Additionally, real-time polymerase chain reaction and enzyme-linked immunosorbent assay results showed that EGCG significantly affected the production of inflammatory factors secreted by MC3T3-E1 cells. Taken together, our

  12. Bone morphogenetic protein-7 promotes chondrogenesis in human amniotic epithelial cells.

    Science.gov (United States)

    Zhou, Junjie; Yu, Guangrong; Cao, Chengfu; Pang, Jinhui; Chen, Xianqi

    2011-06-01

    Bone morphogenetic proteins (BMPs) play important roles at multiple stages of chondrogenesis. This study was undertaken to investigate the potential role of bone morphogenetic protein-7 (BMP-7) in the differentiation of chondrocytes using tissue engineering techniques. The impact of BMP-7 on human amniotic epithelial cells (hAECs) was tested. The hAECs were treated either with recombinant human BMP-7 cDNA or with transforming growth factor beta 1 (TGF-β1) as a positive control for three weeks in vitro. Cartilaginous differentiation and proliferation were assayed by quantitative RT-PCR, histology, and in situ hybridization. Our results were such that hAECs treated with either BMP-7 or TGF-β1 expressed cartilage markers (aggrecan, Sox9, CEP-68, and type II and X collagens) within three weeks. Compared with a control vector, BMP-7 induced a decrease in type I collagen expression, while the transcription of the cartilage-specific type II collagen remained stable. In induction experiments, BMP-7 transgenic hAECs exhibited the largest amount of matrix synthesis. In conclusion, these data indicate that BMP-7 plays an important role in inducing the production of cartilage by hAECs in vitro. Cartilage differentiation and matrix maturation can be promoted by BMPs in a cartilage engineering paradigm. These properties make BMPs promising tools in the engineering of cartilaginous joint bio-prostheses and as candidate biological agents or genes for cartilage stabilisation.

  13. Relevance of collagen piezoelectricity to "Wolff's Law": a critical review.

    Science.gov (United States)

    Ahn, Andrew C; Grodzinsky, Alan J

    2009-09-01

    According to "Wolff's Law", bone is deposited and reinforced at areas of greatest stress. From a clinical perspective, this "law" is supported by the strong association between bone density and physical activity. From a mechanistic standpoint, however, the law presents a challenge to scientists seeking to understand how osteocytes and osteoblasts sense the mechanical load. In the 1960s, collagen piezoelectricity was invoked as a potential mechanism by which osteocytes could detect areas of greater stress but piezoelectricity diminished in importance as more compelling mechanisms, such as streaming potential, were identified. In addition, accumulating evidence for the role of fluid-related shear stress in osteocyte's mechanosensory function has made piezoelectricity seemingly more obsolete in bone physiology. This review critically evaluates the role of collagen piezoelectricity (if any) in Wolff's Law--specifically, the evidence regarding its involvement in strain-generated potentials, existing alternate mechanisms, the present understanding of bone mechanosensation, and whether piezoelectricity serves an influential role within the context of this newly proposed mechanism. In addition to reviewing the literature, this review generates several hypotheses and proposes future research to fully address the relevance of piezoelectricity in bone physiology.

  14. Oral health- related quality of life in patients with rare inherited diseases affecting bone and teeth

    DEFF Research Database (Denmark)

    Gjørup, Hans; Haubek, Dorte

    Background X-linked hypophosphatemia (XLH) is a rare hereditary disease characterized by insufficient bone mineralization. Osteogenesis imperfecta (OI) is another rare inherited disease characterized by fragile bones because of defective collagen synthesis. Both diseases may have impact on teeth...

  15. Osteoconductive properties of two different bioactive glass forms (powder and fiber) combined with collagen

    Science.gov (United States)

    Magri, Angela Maria Paiva; Fernandes, Kelly Rossetti; Ueno, Fabio Roberto; Kido, Hueliton Wilian; da Silva, Antonio Carlos; Braga, Francisco José Correa; Granito, Renata Neves; Gabbai-Armelin, Paulo Roberto; Rennó, Ana Claudia Muniz

    2017-11-01

    Bioactive Glasses (BG) is a group of synthetic silica-based materials with the unique ability to bond to living bone and can be used in bone repair. Although the osteogenic potential of BG, this material may have not present sufficient osteoconductive and osteoinductive properties to allow bone regeneration, especially in compromised situations. In order to overcome this limitation, it was proposed the combination the BG in two forms (powder and fiber) combined with collagen type I (COL-1). The aim of this study was to evaluate the BG/COL-based materials in terms of morphological characteristics, physicochemical features and mineralization. Additionally, the second objective was to investigate and compare the osteoconductive properties of two different bioactive glass forms (powder and fiber) enriched or not with collagen using a tibial bone defect model in rats. For this, four different formulations (BG powder - BGp, BG powder enriched with collagen - BGp/Col, BG fibers - BGf and BGp fibers enriched with collagen - BGf/Col) were developed. The physicochemical and morphological modifications were analyzed by SEM, FTIR, calcium assay and pH measurement. For in vivo evaluations, histopathology, morphometrical and immunohistochemistry were performed in a tibial defect in rats. The FTIR analysis indicated that BGp and BGf maintained the characteristic peaks for this class of material. Furthermore, the calcium assay showed an increased Ca uptake in the BG fibers. The pH measurements revealed that BGp (with or without collagen) presented higher pH values compared to BGf. In addition, the histological analysis demonstrated no inflammation for all groups at the site of the injury, besides a faster material degradation and higher bone ingrowth for groups with collagen. The immunohistochemistry analysis demonstrated Runx-2 and Rank-L expression for all the groups. Those findings support that BGp with collagen can be a promising alternative for treating fracture of difficult

  16. Differential effects of collagen prolyl 3-hydroxylation on skeletal tissues.

    Directory of Open Access Journals (Sweden)

    Erica P Homan

    2014-01-01

    Full Text Available Mutations in the genes encoding cartilage associated protein (CRTAP and prolyl 3-hydroxylase 1 (P3H1 encoded by LEPRE1 were the first identified causes of recessive Osteogenesis Imperfecta (OI. These proteins, together with cyclophilin B (encoded by PPIB, form a complex that 3-hydroxylates a single proline residue on the α1(I chain (Pro986 and has cis/trans isomerase (PPIase activity essential for proper collagen folding. Recent data suggest that prolyl 3-hydroxylation of Pro986 is not required for the structural stability of collagen; however, the absence of this post-translational modification may disrupt protein-protein interactions integral for proper collagen folding and lead to collagen over-modification. P3H1 and CRTAP stabilize each other and absence of one results in degradation of the other. Hence, hypomorphic or loss of function mutations of either gene cause loss of the whole complex and its associated functions. The relative contribution of losing this complex's 3-hydroxylation versus PPIase and collagen chaperone activities to the phenotype of recessive OI is unknown. To distinguish between these functions, we generated knock-in mice carrying a single amino acid substitution in the catalytic site of P3h1 (Lepre1(H662A . This substitution abolished P3h1 activity but retained ability to form a complex with Crtap and thus the collagen chaperone function. Knock-in mice showed absence of prolyl 3-hydroxylation at Pro986 of the α1(I and α1(II collagen chains but no significant over-modification at other collagen residues. They were normal in appearance, had no growth defects and normal cartilage growth plate histology but showed decreased trabecular bone mass. This new mouse model recapitulates elements of the bone phenotype of OI but not the cartilage and growth phenotypes caused by loss of the prolyl 3-hydroxylation complex. Our observations suggest differential tissue consequences due to selective inactivation of P3H1 hydroxylase

  17. Identification of Pyridinoline Trivalent Collagen Cross-Links by Raman Microspectroscopy.

    Science.gov (United States)

    Gamsjaeger, Sonja; Robins, Simon P; Tatakis, Dimitris N; Klaushofer, Klaus; Paschalis, Eleftherios P

    2017-06-01

    Intermolecular cross-linking of bone collagen is intimately related to the way collagen molecules are arranged in a fibril, imparts certain mechanical properties to the fibril, and may be involved in the initiation of mineralization. Raman microspectroscopy allows the analysis of minimally processed bone blocks and provides simultaneous information on both the mineral and organic matrix (mainly type I collagen) components, with a spatial resolution of ~1 μm. The aim of the present study was to validate Raman spectroscopic parameters describing one of the major mineralizing type I trivalent cross-links, namely pyridinoline (PYD). To achieve this, a series of collagen cross-linked peptides with known PYD content (as determined by HPLC analysis), human bone, porcine skin, predentin and dentin animal model tissues were analyzed by Raman microspectroscopy. The results of the present study confirm that it is feasible to monitor PYD trivalent collagen cross-links by Raman spectroscopic analysis in mineralized tissues, exclusively through a Raman band ~1660 wavenumbers. This allows determination of the relative PYD content in undecalcified bone tissues with a spatial resolution of ~1 μm, thus enabling correlations with histologic and histomorphometric parameters.

  18. Tiludronate: bone pharmacology and safety.

    Science.gov (United States)

    Bonjour, J P; Ammann, P; Barbier, A; Caverzasio, J; Rizzoli, R

    1995-11-01

    The pharmacological properties of tiludronate (4-chlorophenyl)thiomethylene bisphosphonate), a sulfured bisphosphonate, have been characterized in a series of preclinical in vivo and in vitro studies. In vivo, tiludronate exerts a dose-dependent inhibitory activity on bone resorption. This property was demonstrated in several animal models, including rats, ewes, and dogs, when bone resorption was induced by administration of retinoid acid or parathyroid hormone, or by immobilization, ovariectomy or orchidectomy. By uncoupling bone resorption from bone formation, tiludronate can induce a positive calcium and phosphate balance. When administered either continuously or intermittently to ovariectomized osteoporotic rats, tiludronate promotes a significant increase in bone mass. This positive effect is associated with an increase in mechanical resistance. Bone tolerance studies indicate that tiludronate is a safe compound with an appreciable therapeutic margin since it can effectively inhibit bone resorption without reducing bone mineralization and strength. In vitro, tiludronate added to bone tissue culture inhibits calcium release, lysosomal enzyme secretion and collagen matrix degradation when induced by various stimulators of bone resorption. At the cellular level, tiludronate does not appear to exert its inhibitory effect on bone resorption by impairing either the recruitment, the migration or the fusion of osteoclast precursors. Tiludronate could act on mature osteoclasts by reducing their capacity to secrete proton into the resorption space and also by favoring their detachment from the bone matrix. The available preclinical data indicate that tiludronate should be an efficacious bisphosphonate in the management of clinical conditions characterized by excessive bone resorption.

  19. Mathematical model for bone mineralization

    OpenAIRE

    Komarova, Svetlana V.; Safranek, Lee; Gopalakrishnan, Jay; Ou, Miao-jung Yvonne; McKee, Marc D.; Murshed, Monzur; Rauch, Frank; Zuhr, Erica

    2015-01-01

    Defective bone mineralization has serious clinical manifestations, including deformities and fractures, but the regulation of this extracellular process is not fully understood. We have developed a mathematical model consisting of ordinary differential equations that describe collagen maturation, production and degradation of inhibitors, and mineral nucleation and growth. We examined the roles of individual processes in generating normal and abnormal mineralization patterns characterized usin...

  20. Multi-protein delivery by nanodiamonds promotes bone formation.

    Science.gov (United States)

    Moore, L; Gatica, M; Kim, H; Osawa, E; Ho, D

    2013-11-01

    Bone morphogenetic proteins (BMPs) are well-studied regulators of cartilage and bone development that have been Food and Drug Administration (FDA)-approved for the promotion of bone formation in certain procedures. BMPs are seeing more use in oral and maxillofacial surgeries because of recent FDA approval of InFUSE(®) for sinus augmentation and localized alveolar ridge augmentation. However, the utility of BMPs in medical and dental applications is limited by the delivery method. Currently, BMPs are delivered to the surgical site by the implantation of bulky collagen sponges. Here we evaluate the potential of detonation nanodiamonds (NDs) as a delivery vehicle for BMP-2 and basic fibroblast growth factor (bFGF). Nanodiamonds are biocompatible, 4- to 5-nm carbon nanoparticles that have previously been used to deliver a wide variety of molecules, including proteins and peptides. We find that both BMP-2 and bFGF are readily loaded onto NDs by physisorption, forming a stable colloidal solution, and are triggered to release in slightly acidic conditions. Simultaneous delivery of BMP-2 and bFGF by ND induces differentiation and proliferation in osteoblast progenitor cells. Overall, we find that NDs provide an effective injectable alternative for the delivery of BMP-2 and bFGF to promote bone formation.

  1. Expression characterization and functional implication of the collagen-modifying Leprecan proteins in mouse gonadal tissue and mature sperm

    Directory of Open Access Journals (Sweden)

    Sarah M. Zimmerman

    2018-02-01

    Full Text Available The Leprecan protein family which includes the prolyl 3-hydroxylase enzymes (P3H1, P3H2, and P3H3, the closely related cartilage-associated protein (CRTAP, and SC65 (Synaptonemal complex 65, aka P3H4, LEPREL4, is involved in the post-translational modification of fibrillar collagens. Mutations in CRTAP, P3H1 and P3H2 cause human genetic diseases. We recently showed that SC65 forms a stable complex in the endoplasmic reticulum with P3H3 and lysyl hydroxylase 1 and that loss of this complex leads to defective collagen lysyl hydroxylation and causes low bone mass and skin fragility. Interestingly, SC65 was initially described as a synaptonemal complex-associated protein, suggesting a potential additional role in germline cells. In the present study, we describe the expression of SC65, CRTAP and other Leprecan proteins in postnatal mouse reproductive organs. We detect SC65 expression in peritubular cells of testis up to 4 weeks of age but not in cells within seminiferous tubules, while its expression is maintained in ovarian follicles until adulthood. Similar to bone and skin, SC65 and P3H3 are also tightly co-expressed in testis and ovary. Moreover, we show that CRTAP, a protein normally involved in collagen prolyl 3-hydroxylation, is highly expressed in follicles and stroma of the ovary and in testes interstitial cells at 4 weeks of age, germline cells and mature sperm. Importantly, CrtapKO mice have a mild but significant increase in morphologically abnormal mature sperm (17% increase compared to WT. These data suggest a role for the Leprecans in the post-translational modification of collagens expressed in the stroma of the reproductive organs. While we could not confirm that SC65 is part of the synaptonemal complex, the expression of CRTAP in the seminiferous tubules and in mature sperm suggest a role in the testis germ cell lineage and sperm morphogenesis.

  2. Collagen based polyurethanes—A review of recent advances and perspective.

    Science.gov (United States)

    Zuber, Mohammad; Zia, Fatima; Zia, Khalid Mahmood; Tabasum, Shazia; Salman, Mahwish; Sultan, Neelam

    2015-09-01

    Collagen is mostly found in fibrous tissues such as tendons, ligaments and skin. Collagen makes up approximately 30% of the proteins within the body. These are tough and strong structures found all over the body: in bones, tendons and ligaments. Collagen being the most abundant protein provides tensile strength via cell matrix interactions to tissue architecture. Biomimetic materials of collagen origin gained wide spread acceptance in clinical applications. Vitamin C deficiency causes scurvy a serious and painful disease in which defective collagen prevents the formation of strong connective tissue, gums deteriorate and bleed, with loss of teeth; skin discolors, and wounds do not heal. Effective collagens prevent the manifestation of such disorders. Polyurethanes on the other hand are frequently used for various applications as they offered in wide-ranging of compositions, properties and complex structures. Collagen/PU bio-composites have potential array for biomedical applications. Considering versatile properties of the elongated fibrils and wide industrial and biomedical applications including biocompatibility of polyurethane, this review shed a light on collagen based polyurethane materials with their potential applications especially focusing the bio-medical field. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Transformation of amorphous calcium carbonate to rod-like single crystal calcite via "copying" collagen template.

    Science.gov (United States)

    Xue, Zhonghui; Hu, Binbin; Dai, Shuxi; Du, Zuliang

    2015-10-01

    Collagen Langmuir films were prepared by spreading the solution of collagen over deionized water, CaCl2 solution and Ca(HCO3)2 solution. Resultant collagen Langmuir monolayers were then compressed to a lateral pressure of 10 mN/m and held there for different duration, allowing the crystallization of CaCO3. The effect of crystallization time on the phase composition and microstructure of CaCO3 was investigated. It was found that amorphous calcium carbonate (ACC) was obtained at a crystallization time of 6 h. The amorphous CaCO3 was transformed to rod-like single crystal calcite crystals at an extended crystallization time of 12 h and 24 h, via "copying" the symmetry and dimensionalities of collagen fibers. Resultant calcite crystallites were well oriented along the longitudinal axis of collagen fibers. The ordered surface structure of collagen fibers and electrostatic interactions played key roles in tuning the oriented nucleation and growth of the calcite crystallites. The mineralized collagen possessing both desired mechanical properties of collagen fiber and good biocompatibility of calcium carbonate may be assembled into an ideal biomaterial for bone implants. Copyright © 2015. Published by Elsevier B.V.

  4. Chondrogenic differentiation of mesenchymal stem cells in a leakproof collagen sponge

    International Nuclear Information System (INIS)

    Chen Guoping; Akahane, Daisuke; Kawazoe, Naoki; Yamamoto, Katsuyuki; Tateishi, Tetsuya

    2008-01-01

    A three-dimensional culture of mesenchymal stem cells (MSCs) in a porous scaffold has been developed as a promising strategy for cartilage tissue engineering. The chondrogenic differentiation of MSCs derived from human bone marrow was studied by culturing the cells in a novel scaffold constructed of leakproof collagen sponge. All the surfaces of the collagen sponge except the top were wrapped with a membrane that has pores smaller than the cells to protect against cell leakage during cell seeding. The cells adhered to the collagen, distributed evenly, and proliferated to fill the spaces in the sponge. Cell seeding efficiency was greater than 95%. The MSCs cultured in the collagen sponge in the presence of TGF-β3 and BMP6 expressed a high level of genes encoding type II and type X collagen, sox9, and aggrecan. Histological examination by HE staining indicated that the differentiated cells showed a round morphology. The extracellular matrices were positively stained by safranin O and toluidine blue. Immunostaining with anti-type II collagen and anti-cartilage proteoglycan showed that type II collagen and cartilage proteoglycan were detected around the cells. These results suggest the chondrogenic differentiation of MSCs when cultured in the collagen sponge in the presence of TGF-β3 and BMP6

  5. Application of Collagen Scaffold in Tissue Engineering: Recent Advances and New Perspectives

    Directory of Open Access Journals (Sweden)

    Chanjuan Dong

    2016-02-01

    Full Text Available Collagen is the main structural protein of most hard and soft tissues in animals and the human body, which plays an important role in maintaining the biological and structural integrity of the extracellular matrix (ECM and provides physical support to tissues. Collagen can be extracted and purified from a variety of sources and offers low immunogenicity, a porous structure, good permeability, biocompatibility and biodegradability. Collagen scaffolds have been widely used in tissue engineering due to these excellent properties. However, the poor mechanical property of collagen scaffolds limits their applications to some extent. To overcome this shortcoming, collagen scaffolds can be cross-linked by chemical or physical methods or modified with natural/synthetic polymers or inorganic materials. Biochemical factors can also be introduced to the scaffold to further improve its biological activity. This review will summarize the structure and biological characteristics of collagen and introduce the preparation methods and modification strategies of collagen scaffolds. The typical application of a collagen scaffold in tissue engineering (including nerve, bone, cartilage, tendon, ligament, blood vessel and skin will be further provided. The prospects and challenges about their future research and application will also be pointed out.

  6. Flexoelectricity in Bones.

    Science.gov (United States)

    Vasquez-Sancho, Fabian; Abdollahi, Amir; Damjanovic, Dragan; Catalan, Gustau

    2018-03-01

    Bones generate electricity under pressure, and this electromechanical behavior is thought to be essential for bone's self-repair and remodeling properties. The origin of this response is attributed to the piezoelectricity of collagen, which is the main structural protein of bones. In theory, however, any material can also generate voltages in response to strain gradients, thanks to the property known as flexoelectricity. In this work, the flexoelectricity of bone and pure bone mineral (hydroxyapatite) are measured and found to be of the same order of magnitude; the quantitative similarity suggests that hydroxyapatite flexoelectricity is the main source of bending-induced polarization in cortical bone. In addition, the measured flexoelectric coefficients are used to calculate the (flexo)electric fields generated by cracks in bone mineral. The results indicate that crack-generated flexoelectricity is theoretically large enough to induce osteocyte apoptosis and thus initiate the crack-healing process, suggesting a central role of flexoelectricity in bone repair and remodeling. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Collagen type 1 (COL1A1) Sp1 binding site polymorphism is associated with osteoporotic fractures but not with bone density in post-menopausal women from the Canary Islands: a preliminary study.

    Science.gov (United States)

    Navarro, Mary C; Sosa, Manuel; del Pino-Montes, Javier; Torres, Armando; Salido, Eduardo; Saavedra, Pedro; Corral-Gudino, Luis; Montilla, Carlos A

    2007-02-01

    An association between the polymorphism for transcription factor Sp1 in the gene COL1A1 and low bone density (BMD) and osteoporotic fractures has been described but not confirmed for all races and ages. The aim of this preliminary work was to ascertain whether this association is present in women from the Canary Islands. Polymerase chain reaction RFLP was used to determine COL1A1 polymorphism Sp1 in 199 consecutive outpatient post-menopausal Caucasian women from the Canary Islands, aged 50-70 years. BMD was measured at lumbar spine and hip by DXA and at third lumbar vertebrae by QCT. Prevalent vertebral fractures were recorded on standard lateral X-ray film. Non-vertebral osteoporotic fractures were registered by medical record and self-reported history. Biochemical markers (serum osteocalcin, tartrate-resistant acid phosphatase), blood calcium and phosphate were also assessed. Distribution genotypes were 113 (50.8%) GG homozygotes, 73 (36.7%) Ss heterozygotes and 7 (3.5%) TT homozygotes. All patients with osteoporotic fractures carried the GG allele more frequently than TT homozygotic women. The odds ratio was 3.01 (95% CI 1.6-5.7) for prevalent vertebral fractures (n=62) and 2.33 (95% CI 1.2-4.4) for all osteoporotic fractures (n=65) for the T-carrying allele vs TT homozygotic women. There was no difference in BMD measured by DXA or QCT, nor in bone markers, blood calcium or phosphate. This preliminary study confirmed that the presence of at least one copy of the T allele is associated with osteoporotic fractures, but not with low BMD, in women from the Canary Islands.

  8. Toxicokinetics of bone lead.

    Science.gov (United States)

    Rabinowitz, M B

    1991-02-01

    This article discusses bone as a source of lead to the rest of the body and as a record of past lead exposure. Bone lead levels generally increase with age at rates dependent on the skeletal site and lead exposure. After occupational exposure, the slow decline in blood lead, a 5- to 19-year half-life, reflects the long skeletal half-life. Repeated measurements of bone lead demonstrate the slow elimination of lead from bone. Stable isotope ratios have revealed many details of skeletal uptake and subsequent release. The bulk turnover rates for compact bone are about 2% per year and 8% for spine. Turnover activity varies with age and health. Even though lead approximates calcium, radium, strontium, barium, fluorine, and other bone seekers, the rates for each are different. A simple, two-pool (bone and blood) kinetic model is presented with proposed numerical values for the changes in blood lead levels that occur with changes in turnover rates. Two approaches are offered to further quantify lead turnover. One involves a study of subjects with known past exposure. Changes in the ratio of blood lead to bone lead with time would reflect the course of bone lead availability. Also, stable isotopes and subjects who move from one geographical area to another offer opportunities. Sequential isotope measurements would indicate how much of the lead in blood is from current exposure or bone stores, distinct from changes in absorption or excretion.

  9. Reconstituted collagen fibrils. Fibrillar and molecular stability of the collagen upon maturation in vitro.

    OpenAIRE

    Danielsen, C C

    1984-01-01

    During the maturation in vitro of reconstituted collagen fibrils prepared from rat skin, the mechanical and thermal stability of collagen increased and the pepsin-solubility decreased. At the same time a larger fraction of the pepsin-soluble collagen attained a lower molecular thermal stability that resulted in a biphasic thermal transition of the soluble collagen. Type-I collagen, with a similar biphasic thermal transition, was isolated from acid-insoluble rat skin collagen.

  10. Technical Note: Calcium and carbon stable isotope ratios as paleodietary indicators.

    Science.gov (United States)

    Melin, Amanda D; Crowley, Brooke E; Brown, Shaun T; Wheatley, Patrick V; Moritz, Gillian L; Yit Yu, Fred Tuh; Bernard, Henry; DePaolo, Donald J; Jacobson, Andrew D; Dominy, Nathaniel J

    2014-08-01

    Calcium stable isotope ratios are hypothesized to vary as a function of trophic level. This premise raises the possibility of using calcium stable isotope ratios to study the dietary behaviors of fossil taxa and to test competing hypotheses on the adaptive origins of euprimates. To explore this concept, we measured the stable isotope composition of contemporary mammals in northern Borneo and northwestern Costa Rica, two communities with functional or phylogenetic relevance to primate origins. We found that bone collagen δ(13) C and δ(15) N values could differentiate trophic levels in each assemblage, a result that justifies the use of these systems to test the predicted inverse relationship between bioapatite δ(13) C and δ(44) Ca values. As expected, taxonomic carnivores (felids) showed a combination of high δ(13) C and low δ(44) Ca values; however, the δ(44) Ca values of other faunivores were indistinguishable from those of primary consumers. We suggest that the trophic insensitivity of most bioapatite δ(44) Ca values is attributable to the negligible calcium content of arthropod prey. Although the present results are inconclusive, the tandem analysis of δ(44) Ca and δ(13) C values in fossils continues to hold promise for informing paleodietary studies and we highlight this potential by drawing attention to the stable isotope composition of the Early Eocene primate Cantius. © 2014 Wiley Periodicals, Inc.

  11. Life history of the individuals buried in the St. Benedict Cemetery (Prague, 15th-18th centuries): insights from (14)C dating and stable isotope (δ(13)C, δ(15)N, δ(18)O) analysis.

    Science.gov (United States)

    Salesse, Kevin; Dufour, Élise; Castex, Dominique; Velemínský, Petr; Santos, Frédéric; Kuchařová, Hedvika; Jun, Libor; Brůžek, Jaroslav

    2013-06-01

    Funerary practices and bioarchaeological (sex and age) data suggest that a mortality crisis linked to an epidemic episode occurred during the fifth phase of the St. Benedict cemetery in Prague (Czech Republic). To identify this mass mortality episode, we reconstructed individual life histories (dietary and mobility factors), assessed the population's biological homogeneity, and proposed a new chronology through stable isotope analysis (δ(13)C, δ(18)O and δ(15)N) and direct radiocarbon dating. Stable isotope analysis was conducted on the bone and tooth enamel (collagen and carbonate) of 19 individuals from three multiple graves (MG) and 12 individuals from individual graves (IG). The δ(15)N values of collagen and the difference between the δ(13)C values of collagen and bone carbonate could indicate that the IG individuals had a richer protein diet than the MG individuals or different food resources. The human bone and enamel carbonate and δ(18)O values suggest that the majority of individuals from MG and all individuals from IG spent most of their lives outside of the Bohemian region. Variations in δ(18)O values also indicate that all individuals experienced residential mobility during their lives. The stable isotope results, biological (age and sex) data and eight (14)C dates clearly differentiate the MG and IG groups. The present work provides evidence for the reuse of the St. Benedict cemetery to bury soldiers despite the funeral protest ban (1635 AD). The Siege of Prague (1742 AD) by French-Bavarian-Saxon armies is identified as the cause of the St. Benedict mass mortality event. Copyright © 2013 Wiley Periodicals, Inc.

  12. A paradigm shift for bone quality in dentistry: A literature review.

    Science.gov (United States)

    Kuroshima, Shinichiro; Kaku, Masaru; Ishimoto, Takuya; Sasaki, Muneteru; Nakano, Takayoshi; Sawase, Takashi

    2017-10-01

    The aim of this study was to present the current concept of bone quality based on the proposal by the National Institutes of Health (NIH) and some of the cellular and molecular factors that affect bone quality. This is a literature review which focuses on collagen, biological apatite (BAp), and bone cells such as osteoblasts and osteocytes. In dentistry, the term "bone quality" has long been considered to be synonymous with bone mineral density (BMD) based on radiographic and sensible evaluations. In 2000, the NIH proposed the concept of bone quality as "the sum of all characteristics of bone that influence the bone's resistance to fracture," which is completely independent of BMD. The NIH defines bone quality as comprising bone architecture, bone turnover, bone mineralization, and micro-damage accumulation. Moreover, our investigations have demonstrated that BAp, collagen, and bone cells such as osteoblasts and osteocytes play essential roles in controlling the current concept of bone quality in bone around hip and dental implants. The current concept of bone quality is crucial for understanding bone mechanical functions. BAp, collagen and osteocytes are the main factors affecting bone quality. Moreover, mechanical loading dynamically adapts bone quality. Understanding the current concept of bone quality is required in dentistry. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  13. Finite Element Analysis of the Hierarchical Structure of Human Bone

    National Research Council Canada - National Science Library

    Dolloff, Katherine

    2003-01-01

    .... Finally, the effective stiffness of the bone was estimated. In order to determine the stiffness of the collagen fiber, a three-dimensional finite element model was developed and a simple analytical model was derived...

  14. Biocompatibility of calcium phosphate bone cement with optimised mechanical properties: an in vivo study.

    Science.gov (United States)

    Palmer, Iwan; Nelson, John; Schatton, Wolfgang; Dunne, Nicholas J; Buchanan, Fraser; Clarke, Susan A

    2016-12-01

    This work establishes the in vivo performance of modified calcium phosphate bone cements for vertebroplasty of spinal fractures using a lapine model. A non-modified calcium phosphate bone cement and collagen-calcium phosphate bone cements composites with enhanced mechanical properties, utilising either bovine collagen or collagen from a marine sponge, were compared to a commercial poly(methyl methacrylate) cement. Conical cement samples (8 mm height × 4 mm base diameter) were press-fit into distal femoral condyle defects in New Zealand White rabbits and assessed after 5 and 10 weeks. Bone apposition and tartrate-resistant acid phosphatase activity around cements were assessed. All implants were well tolerated, but bone apposition was higher on calcium phosphate bone cements than on poly(methyl methacrylate) cement. Incorporation of collagen showed no evidence of inflammatory or immune reactions. Presence of positive tartrate-resistant acid phosphatase staining within cracks formed in calcium phosphate bone cements suggested active osteoclasts were present within the implants and were actively remodelling within the cements. Bone growth was also observed within these cracks. These findings confirm the biological advantages of calcium phosphate bone cements over poly(methyl methacrylate) and, coupled with previous work on enhancement of mechanical properties through collagen incorporation, suggest collagen-calcium phosphate bone cement composite may offer an alternative to calcium phosphate bone cements in applications where low setting times and higher mechanical stability are important.

  15. Dynamic culture of a thermosensitive collagen hydrogel as an extracellular matrix improves the construction of tissue-engineered peripheral nerve.

    Science.gov (United States)

    Huang, Lanfeng; Li, Rui; Liu, Wanguo; Dai, Jin; Du, Zhenwu; Wang, Xiaonan; Ma, Jianchao; Zhao, Jinsong

    2014-07-15

    Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, but cell loss between seeding and adhesion to the scaffold remains inevitable. A thermosensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve composites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesenchymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to fill in the pores, and seeded cells adhered onto the poly-L-lactic acid fibers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive collagen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermosensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhesion stage. Moreover, seeded cells were distributed throughout the material.

  16. Toxicokinetics of bone lead.

    OpenAIRE

    Rabinowitz, M B

    1991-01-01

    This article discusses bone as a source of lead to the rest of the body and as a record of past lead exposure. Bone lead levels generally increase with age at rates dependent on the skeletal site and lead exposure. After occupational exposure, the slow decline in blood lead, a 5- to 19-year half-life, reflects the long skeletal half-life. Repeated measurements of bone lead demonstrate the slow elimination of lead from bone. Stable isotope ratios have revealed many details of skeletal uptake a...

  17. Bone Diseases

    Science.gov (United States)

    ... avoid smoking and drinking too much alcohol. Bone diseases can make bones easy to break. Different kinds ... break Osteogenesis imperfecta makes your bones brittle Paget's disease of bone makes them weak Bones can also ...

  18. Use of cis-[18F]fluoro-proline for assessment of exercise-related collagen synthesis in musculoskeletal connective tissue.

    Directory of Open Access Journals (Sweden)

    Dorthe Skovgaard

    Full Text Available Protein turnover in collagen rich tissue is influenced by exercise, but can only with difficulty be studied in vivo due to use of invasive procedure. The present study was done to investigate the possibility of applying the PET-tracer, cis-[(18F]fluoro-proline (cis-Fpro, for non-invasive assessment of collagen synthesis in rat musculoskeletal tissues at rest and following short-term (3 days treadmill running. Musculoskeletal collagen synthesis was studied in rats at rest and 24 h post-exercise. At each session, rats were PET scanned at two time points following injection of cis-FPro: (60 and 240 min p.i. SUV were calculated for Achilles tendon, calf muscle and tibial bone. The PET-derived results were compared to mRNA expression of collagen type I and III. Tibial bone had the highest SUV that increased significantly (p<0.001 from the early (60 min to the late (240 min PET scan, while SUV in tendon and muscle decreased (p<0.001. Exercise had no influence on SUV, which was contradicted by an increased gene expression of collagen type I and III in muscle and tendon. The clearly, visible uptake of cis-Fpro in the collagen-rich musculoskeletal tissues is promising for multi-tissue studies in vivo. The tissue-specific differences with the highest basal uptake in bone are in accordance with earlier studies relying on tissue incorporation of isotopic-labelled proline. A possible explanation of the failure to demonstrate enhanced collagen synthesis following exercise, despite augmented collagen type I and III transcription, is that SUV calculations are not sensitive enough to detect minor changes in collagen synthesis. Further studies including kinetic compartment modeling must be performed to establish whether cis-Fpro can be used for non-invasive in-vivo assessment of exercise-induced changes in musculoskeletal collagen synthesis.

  19. Canine investigation of rhBMP-2, autogenous bone graft, and rhBMP-2 with autogenous bone graft for the healing of a large segmental tibial defect.

    Science.gov (United States)

    Boyce, Andrew S; Reveal, Greg; Scheid, D Kevin; Kaehr, David M; Maar, Dean; Watts, Melanie; Stone, Marcus B

    2009-01-01

    The purpose of this study was to compare the effects of bone morphogenetic protein, bone morphogenetic protein with autogenous bone graft (ABG), and ABG alone on the healing of a large bone defect in the canine tibia. Fifteen 45- to 55-lb canines were randomly assigned to 1 of 5 treatment groups, 3 per group. The groups included (1) recombinant human bone morphogenetic protein (rhBMP-2, 0.43 mg/mL)/absorbable collagen sponge (ACS) + collagen/ceramic matrix (CCM), (2) rhBMP-2 (0.22 mg/mL) ACS + CCM, (3) rhBMP-2 (0.43 mg/mL) ACS + ABG, (4) rhBMP-2 (0.22 mg/mL) ACS + ABG, and (5) ABG alone. A 5-mL defect was created in the right tibia and fixed with a 4.5 mm locking plate and 1 of the grafts described above implanted. X-rays were taken biweekly for 12 weeks and evaluated for radiographic union. Representative histology was also examined. All defects treated with rhBMP-2 (any combination) healed at 6.0 +/- 0.9 weeks. None of the ABG alone-treated defects were healed at 12 weeks. Dogs receiving rhBMP-2/ACS + CCM healed at 5.7 +/- 0.8 weeks, whereas rhBMP-2/ACS + ABG defects healed at 6.3 +/- 0.8 weeks. Histology showed healing consistent with 12-week radiologic results. Large segmental defects in canine tibiae can be effectively healed with stable fixation and rhBMP-2/ACS + ABG or CCM. These conclusions may offer insight into the clinical treatment of segmental defect nonunions in the human.

  20. Laser-Modified Surface Enhances Osseointegration and Biomechanical Anchorage of Commercially Pure Titanium Implants for Bone-Anchored Hearing Systems

    Science.gov (United States)

    Omar, Omar; Simonsson, Hanna; Palmquist, Anders; Thomsen, Peter

    2016-01-01

    Osseointegrated implants inserted in the temporal bone are a vital component of bone-anchored hearing systems (BAHS). Despite low implant failure levels, early loading protocols and simplified procedures necessitate the application of implants which promote bone formation, bone bonding and biomechanical stability. Here, screw-shaped, commercially pure titanium implants were selectively laser ablated within the thread valley using an Nd:YAG laser to produce a microtopography with a superimposed nanotexture and a thickened surface oxide layer. State-of-the-art machined implants served as controls. After eight weeks’ implantation in rabbit tibiae, resonance frequency analysis (RFA) values increased from insertion to retrieval for both implant types, while removal torque (RTQ) measurements showed 153% higher biomechanical anchorage of the laser-modified implants. Comparably high bone area (BA) and bone-implant contact (BIC) were recorded for both implant types but with distinctly different failure patterns following biomechanical testing. Fracture lines appeared within the bone ~30–50 μm from the laser-modified surface, while separation occurred at the bone-implant interface for the machined surface. Strong correlations were found between RTQ and BIC and between RFA at retrieval and BA. In the endosteal threads, where all the bone had formed de novo, the extracellular matrix composition, the mineralised bone area and osteocyte densities were comparable for the two types of implant. Using resin cast etching, osteocyte canaliculi were observed directly approaching the laser-modified implant surface. Transmission electron microscopy showed canaliculi in close proximity to the laser-modified surface, in addition to a highly ordered arrangement of collagen fibrils aligned parallel to the implant surface contour. It is concluded that the physico-chemical surface properties of laser-modified surfaces (thicker oxide, micro- and nanoscale texture) promote bone bonding

  1. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1994-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets, with a few more additions - with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers - exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the foree of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc. (orig.)

  2. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  3. SILICON AND BONE HEALTH

    Science.gov (United States)

    JUGDAOHSINGH, R.

    2009-01-01

    Low bone mass (osteoporosis) is a silent epidemic of the 21st century, which presently in the UK results in over 200,000 fractures annually at a cost of over one billion pounds. Figures are set to increase worldwide. Understanding the factors which affect bone metabolism is thus of primary importance in order to establish preventative measures or treatments for this condition. Nutrition is an important determinant of bone health, but the effects of the individual nutrients and minerals, other than calcium, is little understood. Accumulating evidence over the last 30 years strongly suggest that dietary silicon is beneficial to bone and connective tissue health and we recently reported strong positive associations between dietary Si intake and bone mineral density in US and UK cohorts. The exact biological role(s) of silicon in bone health is still not clear, although a number of possible mechanisms have been suggested, including the synthesis of collagen and/or its stabilization, and matrix mineralization. This review gives an overview of this naturally occurring dietary element, its metabolism and the evidence of its potential role in bone health. PMID:17435952

  4. RELEVANCE OF COLLAGEN PIEZOELECTRICITY TO “WOLFF’S LAW”: A CRITICAL REVIEW

    OpenAIRE

    Ahn, Andrew C.; Grodzinsky, Alan J.

    2009-01-01

    According to “Wolff’s Law”, bone is deposited and reinforced at areas of greatest stress. From a clinical perspective, this “law” is supported by the strong association between bone density and physical activity. From a mechanistic standpoint, however, the law presents a challenge to scientists seeking to understand how osteocytes and osteoblasts sense the mechanical load. In the 1960’s, collagen piezoelectricity was invoked as a potential mechanism by which osteocytes could detect areas of g...

  5. Microspectroscopic evidence of cretaceous bone proteins.

    Directory of Open Access Journals (Sweden)

    Johan Lindgren

    Full Text Available Low concentrations of the structural protein collagen have recently been reported in dinosaur fossils based primarily on mass spectrometric analyses of whole bone extracts. However, direct spectroscopic characterization of isolated fibrous bone tissues, a crucial test of hypotheses of biomolecular preservation over deep time, has not been performed. Here, we demonstrate that endogenous proteinaceous molecules are retained in a humerus from a Late Cretaceous mosasaur (an extinct giant marine lizard. In situ immunofluorescence of demineralized bone extracts shows reactivity to antibodies raised against type I collagen, and amino acid analyses of soluble proteins extracted from the bone exhibit a composition indicative of structural proteins or their breakdown products. These data are corroborated by synchrotron radiation-based infrared microspectroscopic studies demonstrating that amino acid containing matter is located in bone matrix fibrils that express imprints of the characteristic 67 nm D-periodicity typical of collagen. Moreover, the fibrils differ significantly in spectral signature from those of potential modern bacterial contaminants, such as biofilms and collagen-like proteins. Thus, the preservation of primary soft tissues and biomolecules is not limited to large-sized bones buried in fluvial sandstone environments, but also occurs in relatively small-sized skeletal elements deposited in marine sediments.

  6. Characterization of the bone matrix and its contribution to tooth loss in human cadaveric mandibles.

    Science.gov (United States)

    Matsuura, Takashi; Sasaki, Michiko; Katafuchi, Michitsuna; Tokutomi, Kentaro; Mizumachi, Emiri; Makino, Michiko; Naito, Toru; Sato, Hironobu

    2014-11-01

    It is uncertain as to what extent the major bone matrix constituents, mineral and collagen, show inter-individual variation and dependence on age and sex in jawbones. The purpose of this study was to clarify this uncertainty using cadaveric mandibles and investigate the association of bone matrix with the number of existing teeth. Cortical bone samples (1 × 1 cm) collected from the mental of 48 cadaveric mandibles (27 men and 21 women; age range = 56-93 years and 63-103 years, respectively) were used to quantify three bone matrix indices: mineral content, collagen content and extent of lysine hydroxylation of collagen. Associations with age and comparisons by sex were evaluated based on bone matrix indices and the numbers of existing teeth. The numbers of existing teeth were compared between the groups showing low and high bone matrix index values. A great amount of inter-individual variation was seen in all bone matrix indices. No bone matrix indices were associated with age, while the number of existing teeth was negatively associated with age. The bone matrix indices and number of existing teeth did not differ by sex. The number of existing teeth was nearly twice as high in the group showing high collagen content as in the low collagen group; however, an analysis of covariance showed a significant inter-group difference not from bone matrix indices, but rather from age. Interestingly, in comparison to femoral collagen, mandibular collagen showed lower lysine hydroxylation, which can represent an aspect of bone quality. Mandibular bone matrix shows great inter-individual variation and is independent of age and sex, but did not show as strong a relationship with tooth loss as age. Even so, mandibular collagen may represent a unique characteristic of bone matrix and deserves to be further investigated.

  7. Homozygosity for a Missense Mutation in SERPINH1, which Encodes the Collagen Chaperone Protein HSP47, Results in Severe Recessive Osteogenesis Imperfecta

    OpenAIRE

    Christiansen, Helena E.; Schwarze, Ulrike; Pyott, Shawna M.; AlSwaid, Abdulrahman; Al Balwi, Mohammed; Alrasheed, Shatha; Pepin, Melanie G.; Weis, Mary Ann; Eyre, David R.; Byers, Peter H.

    2010-01-01

    Osteogenesis imperfecta (OI) is characterized by bone fragility and fractures that may be accompanied by bone deformity, dentinogenesis imperfecta, short stature, and shortened life span. About 90% of individuals with OI have dominant mutations in the type I collagen genes COL1A1 and COL1A2. Recessive forms of OI resulting from mutations in collagen-modifying enzymes and chaperones CRTAP, LEPRE1, PPIB, and FKBP10 have recently been identified. We have identified an autosomal-recessive missens...

  8. Degradable Chitosan-Collagen Composites Seeded with Cells as Tissue Engineered Heart Valves.

    Science.gov (United States)

    Fu, Jian-Hua; Zhao, Man; Lin, Yan-Rong; Tian, Xu-Dong; Wang, Ya-Dong; Wang, Zhen-Xing; Wang, Le-Xin

    2017-01-01

    Degradable collagen-chitosan composite materials have been used to fabricate tissue engineered heart valves. The aims of this study were to demonstrate that the collagen-chitosan composite scaffolds are cytocompatible, and endothelial cells can be differentiated from bone marrow mesenchymal stem cells (BMSCs) when seeded onto the scaffolds. The adhesion and biological activities of the seeded cells were also investigated. Collagen-chitosan composite material was used as the cell matrix, and smooth muscle cells, fibroblasts and BMSCs were used as seed cells. After four weeks of in vitro culture, the smooth muscle cells, fibroblasts, and BMSCs were sequentially seeded into the collagen-chitosan composite material. After four weeks in culture, the cellular density and activity were assessed on segments of the tissue engineered heart valve scaffolds to determine the cell viability and proliferation in the collagen-chitosan composite material. The tissue engineered heart valves stained positively for both smooth muscle actin and endothelial cell factor VIII, suggesting that the seeded cells were in fact smooth muscle cells, fibroblasts, and endothelial cells. The 6-ketone prostaglandin content, as measured by radioimmunoassay, of the collagen-chitosan cell culture fluid was higher than that of the serum-free medium (P biological activity after being cultured in vitro and seeded into the collagen-chitosan composite material. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  9. Nanoscale characterization of isolated individual type I collagen fibrils: polarization and piezoelectricity.

    Science.gov (United States)

    Minary-Jolandan, Majid; Yu, Min-Feng

    2009-02-25

    Piezoresponse force microscopy was applied to directly study individual type I collagen fibrils with diameters of approximately 100 nm isolated from bovine Achilles tendon. It was revealed that single collagen fibrils behave predominantly as shear piezoelectric materials with a piezoelectric coefficient on the order of 1 pm V(-1), and have unipolar axial polarization throughout their entire length. It was estimated that, under reasonable shear load conditions, the fibrils were capable of generating an electric potential up to tens of millivolts. The result substantiates the nanoscale origin of piezoelectricity in bone and tendons, and implies also the potential importance of the shear load-transfer mechanism, which has been the principle basis of the nanoscale mechanics model of collagen, in mechanoelectric transduction in bone.

  10. A Mineralized Collagen-Polycaprolactone Composite Promotes Healing of a Porcine Mandibular Defect.

    Science.gov (United States)

    Weisgerber, Daniel W; Milner, Derek J; Lopez-Lake, Heather; Rubessa, Marcello; Lotti, Sammi; Polkoff, Kathryn; Hortensius, Rebecca A; Flanagan, Colleen L; Hollister, Scott J; Wheeler, Matthew B; Harley, Brendan A C

    2018-02-01

    A tissue engineering approach to address craniofacial defects requires a biomaterial that balances macro-scale mechanical stiffness and strength with the micron-scale features that promote cell expansion and tissue biosynthesis. Such criteria are often in opposition, leading to suboptimal mechanical competence or bioactivity. We report the use of a multiscale composite biomaterial that integrates a polycaprolactone (PCL) reinforcement structure with a mineralized collagen-glycosaminoglycan scaffold to circumvent conventional tradeoffs between mechanics and bioactivity. The composite promotes activation of the canonical bone morphogenetic protein 2 (BMP-2) pathway and subsequent mineralization of adipose-derived stem cells in the absence of supplemental BMP-2 or osteogenic media. We subsequently examined new bone infill in the acellular composite, scaffold alone, or PCL support in 10 mm dia. ramus mandibular defects in Yorkshire pigs. We report an analytical approach to quantify radial, angular, and depth bone infill from micro-computed tomography data. The collagen-PCL composite showed improved overall infill, and significantly increased radial and angular bone infill versus the PCL cage alone. Bone infill was further enhanced in the composite for defects that penetrated the medullary cavity, suggesting recruitment of marrow-derived cells. These results indicate a multiscale mineralized collagen-PCL composite offers strategic advantages for regenerative repair of craniofacial bone defects.

  11. Bone organic matter and radiocarbon dating

    International Nuclear Information System (INIS)

    Vance Haynes, C.

    1967-01-01

    Unsatisfactory results with the carbon-14 dating of bone organic matter have caused bone radiocarbon dates to be considered unreliable. Even the so-called collagen dates are commonly erroneous for samples more than a few thousand years old. Current efforts at the University of Arizona are directed towards understanding why bone yields erroneous results, what is the nature of the contaminants, and what can be done to obtain accurate dates from bone organic matter. Bone from extinct Pleistocene animals from stratified sites with adequate geochronological control was selected for analysis. From each sample four organic fractions (humic acids, fulvic acids, soluble bone organic matter, and insoluble bone organic matter) were chemically separated and analysed for carbon-14. The results were then compared to radiocarbon dates on associated wood or charcoal or age estimates based upon other data. Results suggest that collagen, free of humic acids, yields reliable results and is the only reliable organic fraction for dating fossil bone. Humic acids that are not removed by standard pre-treatment are a prime suspect in the contamination of 'collagen' and can lead to dates that are too old as well as too young. (author)

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

    Science.gov (United States)

    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. Copyright © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  13. Micromechanical bending of single collagen fibrils using atomic force microscopy

    NARCIS (Netherlands)

    Yang, Lanti; van der Werf, Kees O; Koopman, Bart F J M; Subramaniam, Vinod; Bennink, Martin L; Dijkstra, Pieter J; Feijen, Jan

    A new micromechanical technique was developed to study the mechanical properties of single collagen fibrils. Single collagen fibrils, the basic components of the collagen fiber, have a characteristic highly organized structure. Fibrils were isolated from collagenous materials and their mechanical

  14. A BMP responsive transcriptional region in the chicken type X collagen gene.

    Science.gov (United States)

    Volk, S W; Luvalle, P; Leask, T; Leboy, P S

    1998-10-01

    Bone morphogenetic proteins (BMPs) were originally identified by their ability to induce ectopic bone formation and have been shown to promote both chondrogenesis and chondrocyte hypertrophy. BMPs have recently been found to activate a membrane serine/threonine kinase signaling mechanism in a variety of cell types, but the downstream effectors of BMP signaling in chondrocyte differentiation remain unidentified. We have previously reported that BMP-2 markedly stimulates type X collagen expression in prehypertrophic chick sternal chondrocytes, and that type X collagen mRNA levels in chondrocytes cultured under serum-free (SF) conditions are elevated 3- to 5-fold within 24 h. To better define the molecular mechanisms of induction of chondrocyte hypertrophy by BMPs, we examined the effect of BMPs on type X collagen production by 15-day chick embryo sternal chondrocytes cultured under SF conditions in the presence or absence of 30 ng/ml BMP-2, BMP-4, or BMP-7. Two populations of chondrocytes were used: one representing resting cartilage isolated from the caudal third of the sterna and the second representing prehypertrophic cartilage from the cephalic third of the sterna. BMP-2, BMP-4, and BMP-7 all effectively promoted chondrocyte maturation of cephalic sternal chondrocytes as measured by high levels of alkaline phosphatase, diminished levels of type II collagen, and induction of the hypertrophic chondrocyte-specific marker, type X collagen. To test whether BMP control of type X collagen expression occurs at the transcriptional level, we utilized plasmid constructs containing the chicken collagen X promoter and 5' flanking regions fused to a reporter gene. Constructs were transiently transfected into sternal chondrocytes cultured under SF conditions in the presence or absence of 30 ng/ml BMP-2, BMP-4, or BMP-7. A 533 bp region located 2.4-2.9 kb upstream from the type X collagen transcriptional start site was both necessary and sufficient for strong BMP responsiveness

  15. Biology, chemistry and pathology of collagen

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmajer, R.; Olsen, B.R.; Kuhn, K.

    1985-01-01

    This book consists of five parts and a section of poster papers. Some of the articles are: Structure of the Type II Collagen Gene; Structural and Functional Analysis of the Genes for ..cap alpha..2(1) and ..cap alpha..1(III) collagens; Structure and Expression of the Collagen Genes of C. Elegans; Molecular Basis of Clinical Heterogeneity in the Ehlers-Danlos Syndrome; and Normal and Mutant Human Collagen Genes.

  16. Bone quality: the determinants of bone strength and fragility.

    Science.gov (United States)

    Fonseca, Hélder; Moreira-Gonçalves, Daniel; Coriolano, Hans-Joachim Appell; Duarte, José Alberto

    2014-01-01

    Bone fragility is a major health concern, as the increased risk of bone fractures has devastating outcomes in terms of mortality, decreased autonomy, and healthcare costs. Efforts made to address this problem have considerably increased our knowledge about the mechanisms that regulate bone formation and resorption. In particular, we now have a much better understanding of the cellular events that are triggered when bones are mechanically stimulated and how these events can lead to improvements in bone mass. Despite these findings at the molecular level, most exercise intervention studies reveal either no effects or only minor benefits of exercise programs in improving bone mineral density (BMD) in osteoporotic patients. Nevertheless, and despite that BMD is the gold standard for diagnosing osteoporosis, this measure is only able to provide insights regarding the quantity of bone tissue. In this article, we review the complex structure of bone tissue and highlight the concept that its mechanical strength stems from the interaction of several different features. We revisited the available data showing that bone mineralization degree, hydroxyapatite crystal size and heterogeneity, collagen properties, osteocyte density, trabecular and cortical microarchitecture, as well as whole bone geometry, are determinants of bone strength and that each one of these properties may independently contribute to the increased or decreased risk of fracture, even without meaningful changes in aBMD. Based on these findings, we emphasize that while osteoporosis (almost) always causes bone fragility, bone fragility is not always caused just by osteoporosis, as other important variables also play a major role in this etiology. Furthermore, the results of several studies showing compelling data that physical exercise has the potential to improve bone quality and to decrease fracture risk by influencing each one of these determinants are also reviewed. These findings have meaningful clinical

  17. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  18. Incorporation of a Decorin Biomimetic Enhances the Mechanical Properties of Electrochemically Aligned Collagen Threads

    Science.gov (United States)

    Kishore, Vipuil; Paderi, John E.; Akkus, Anna; Smith, Katie M.; Balachandran, Dave; Beaudoin, Stephen; Panitch, Alyssa; Akkus, Ozan

    2011-01-01

    Orientational anisotropy of collagen molecules is integral for the mechanical strength of collagen-rich tissues. We have previously reported a novel methodology to synthesize highly oriented electrochemically aligned collagen (ELAC) threads with mechanical properties converging upon those of native tendon. Decorin, a small leucine rich proteoglycan (SLRP), binds to fibrillar collagen and has been suggested to enhance the mechanical properties of tendon. Based on the structure of natural decorin, we have previously designed and synthesized a peptidoglycan (DS-SILY) that mimics decorin both structurally and functionally. In this study, we investigated the effect of the incorporation of DS-SILY on the mechanical properties and structural organization of ELAC threads. The results indicated that the addition of DS-SILY at a molar ratio of 30:1 (Collagen:DS-SILY) significantly enhanced the ultimate stress and ultimate strain of the ELAC threads. Furthermore, differential scanning calorimetry revealed that the addition of DS-SILY at a molar ratio of 30:1 resulted in a more thermally stable collagen structure. However, addition of DS-SILY at a higher concentration (10:1 Collagen:DS-SILY) yielded weaker threads with mechanical properties comparable to collagen control threads. Transmission emission microscopy revealed that the addition of DS-SILY at a higher concentration (10:1) resulted in pronounced aggregation of collagen fibrils. More importantly, these aggregates were not aligned along the long axis of the ELAC thereby compromising on the overall tensile properties of the material. We conclude that incorporation of an optimal amount of DS-SILY is a promising approach to synthesize mechanically competent collagen based biomaterials for tendon tissue engineering applications. PMID:21356334

  19. Oral histories: a simple method of assigning chronological age to isotopic values from human dentine collagen.

    Science.gov (United States)

    Beaumont, Julia; Montgomery, Janet

    2015-01-01

    Stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in bone and dentine collagen have been used for over 30 years to estimate palaeodiet, subsistence strategy, breastfeeding duration and migration within burial populations. Recent developments in dentine microsampling allow improved temporal resolution for dietary patterns. A simple method is proposed which could be applied to human teeth to estimate chronological age represented by dentine microsamples in the direction of tooth growth, allowing comparison of dietary patterns between individuals and populations. The method is tested using profiles from permanent and deciduous teeth of two individuals. Using a diagrammatic representation of dentine development by approximate age for each human tooth (based on the Queen Mary University of London Atlas), this study estimated the age represented by each dentine section. Two case studies are shown: comparison of M1 and M2 from a 19th century individual from London, England, and identification of an unknown tooth from an Iron Age female adult from Scotland. The isotopic profiles demonstrate that variations in consecutively-forming teeth can be aligned using this method to extend the dietary history of an individual or identify an unknown tooth by matching the profiles.

  20. Building blocks of Collagen based biomaterial devices

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Building blocks of Collagen based biomaterial devices. Collagen as a protein. Collagen in tissues and organs. Stabilizing and cross linking agents. Immunogenicity. Hosts (drugs). Controlled release mechanisms of hosts. Biodegradability, workability into devices ...

  1. BIOMATERIAL IMPLANTS IN BONE FRACTURES PRODUCED IN RATS FIBULAS

    Science.gov (United States)

    Shirane, Henrique Yassuhiro; Oda, Diogo Yochizumi; Pinheiro, Thiago Cerizza; Cunha, Marcelo Rodrigues da

    2015-01-01

    To evaluate the importance of collagen and hydroxyapatite in the regeneration of fractures experimentally induced in the fibulas of rats. Method: 15 rats were used. These were subjected to surgery to remove a fragment from the fibula. This site then received a graft consisting of a silicone tubes filled with hydroxyapatite and collagen. Results: Little bone neoformation occurred inside the tubes filled with the biomaterials. There was more neoformation in the tubes with collagen. Conclusion: The biomaterials used demonstrated biocompatibility and osteoconductive capacity that was capable of stimulating osteogenesis, even in bones with secondary mechanical and morphological functions such as the fibula of rats. PMID:27047813

  2. Age variations in the properties of human tibial trabecular bone

    DEFF Research Database (Denmark)

    Ding, Ming; Dalstra, M; Danielsen, CC

    1997-01-01

    We tested in compression specimens of human proximal tibial trabecular bone from 31 normal donors aged from 16 to 83 years and determined the mechanical properties, density and mineral and collagen content. Young's modulus and ultimate stress were highest between 40 and 50 years, whereas ultimate...... amount of collagen) varied with failure energy. Collagen concentration was maximal at younger ages but varied little with age. Our results suggest that the decrease in mechanical properties of trabecular bone such as Young's modulus and ultimate stress is mainly a consequence of the loss of trabecular...

  3. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth.The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests.The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect.Our findings suggested a new bioactive

  4. B vitamins, homocysteine and bone health.

    Science.gov (United States)

    Fratoni, Valentina; Brandi, Maria Luisa

    2015-03-30

    Nutrition is one of the most important modifiable factors involved in the development and maintenance of good bone health. Calcium and Vitamin D have confirmed and established roles in the maintenance of proper bone health. However, other nutritional factors could also be implicated. This review will explore the emerging evidence of the supporting role of certain B Vitamins as modifiable factors associated with bone health. Individuals with high levels of homocysteine (hcy) exhibit reduced bone mineral density (BMD), alteration in microarchitecture and increased bone fragility. The pathophysiology caused by high serum homocysteine is not completely clear regarding fractures, but it may involve factors, such as bone mineral density, bone turnover, bone blood flow and collagen cross-linking. It is uncertain whether supplementation with B Vitamins, such as folate, Vitamin B1, and Vitamin B6, could decrease hip fracture incidence, but the results of further clinical trials should be awaited before a conclusion is drawn.

  5. Application of collagen hydrogel/sponge scaffold facilitates periodontal wound healing in class II furcation defects in beagle dogs.

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    Kosen, Y; Miyaji, H; Kato, A; Sugaya, T; Kawanami, M

    2012-10-01

    A three-dimensional scaffold may play an important role in periodontal tissue engineering. We prepared bio-safe collagen hydrogel, which exhibits properties similar to those of native extracellular matrix. The aim of this study was to examine the effect of implantation of collagen hydrogel/sponge scaffold on periodontal wound healing in class II furcation defects in dogs. The collagen hydrogel/sponge scaffold was prepared by injecting collagen hydrogel, cross-linked to the ascorbate-copper ion system, into a collagen sponge. Class II furcation defects (of 5 mm depth and 3 mm width) were surgically created in beagle dogs. The exposed root surface was planed and demineralized with EDTA. In the experimental group, the defect was filled with collagen hydrogel/sponge scaffold. In the control group, no implantation was performed. Histometric parameters were evaluated 2 and 4 wk after surgery. At 2 wk, the collagen hydrogel/sponge scaffold displayed high biocompatibility and biodegradability with numerous cells infiltrating the scaffold. In the experimental group, reconstruction of alveolar bone and cementum was frequently observed 4 wk after surgery. Periodontal ligament tissue was also re-established between alveolar bone and cementum. Volumes of new bone, new cementum and new periodontal ligament were significantly greater in the experimental group than in the control group. In addition, epithelial down-growth was suppressed by application of collagen hydrogel. The collagen hydrogel/sponge scaffold possessed high tissue compatibility and degradability. Implantation of the scaffold facilitated periodontal wound healing in class II furcation defects in beagle dogs. © 2012 John Wiley & Sons A/S.

  6. Collagen breakdown products and lung collagen metabolism: an in vitro study on fibroblast cultures.

    OpenAIRE

    Gardi, C.; Calzoni, P.; Marcolongo, P.; Cavarra, E.; Vanni, L.; Lungarella, G.

    1994-01-01

    BACKGROUND--In fibrotic diseases such as pulmonary fibrosis there is evidence suggesting enhanced synthesis and degradation of lung connective tissue components, including collagen. It has therefore been hypothesised that products of collagen degradation may have a role in the promotion of collagen deposition. In support of this hypothesis, it has recently been shown that intravenous injection of lung collagen degradation products in experimental animals stimulated collagen synthesis leading ...

  7. Abnormal Type I Collagen Post-translational Modification and Crosslinking in a Cyclophilin B KO Mouse Model of Recessive Osteogenesis Imperfecta

    Science.gov (United States)

    Cabral, Wayne A.; Perdivara, Irina; Weis, MaryAnn; Terajima, Masahiko; Blissett, Angela R.; Chang, Weizhong; Perosky, Joseph E.; Makareeva, Elena N.; Mertz, Edward L.; Leikin, Sergey; Tomer, Kenneth B.; Kozloff, Kenneth M.; Eyre, David R.; Yamauchi, Mitsuo; Marini, Joan C.

    2014-01-01

    Cyclophilin B (CyPB), encoded by PPIB, is an ER-resident peptidyl-prolyl cis-trans isomerase (PPIase) that functions independently and as a component of the collagen prolyl 3-hydroxylation complex. CyPB is proposed to be the major PPIase catalyzing the rate-limiting step in collagen folding. Mutations in PPIB cause recessively inherited osteogenesis imperfecta type IX, a moderately severe to lethal bone dysplasia. To investigate the role of CyPB in collagen folding and post-translational modifications, we generated Ppib−/− mice that recapitulate the OI phenotype. Knock-out (KO) mice are small, with reduced femoral areal bone mineral density (aBMD), bone volume per total volume (BV/TV) and mechanical properties, as well as increased femoral brittleness. Ppib transcripts are absent in skin, fibroblasts, femora and calvarial osteoblasts, and CyPB is absent from KO osteoblasts and fibroblasts on western blots. Only residual (2–11%) collagen prolyl 3-hydroxylation is detectable in KO cells and tissues. Collagen folds more slowly in the absence of CyPB, supporting its rate-limiting role in folding. However, treatment of KO cells with cyclosporine A causes further delay in folding, indicating the potential existence of another collagen PPIase. We confirmed and extended the reported role of CyPB in supporting collagen lysyl hydroxylase (LH1) activity. Ppib−/− fibroblast and osteoblast collagen has normal total lysyl hydroxylation, while increased collagen diglycosylation is observed. Liquid chromatography/mass spectrometry (LC/MS) analysis of bone and osteoblast type I collagen revealed site-specific alterations of helical lysine hydroxylation, in particular, significantly reduced hydroxylation of helical crosslinking residue K87. Consequently, underhydroxylated forms of di- and trivalent crosslinks are strikingly increased in KO bone, leading to increased total crosslinks and decreased helical hydroxylysine- to lysine-derived crosslink ratios. The altered

  8. Stabilization of collagen by cross-linking with oxazolidine E-resorcinol.

    Science.gov (United States)

    Chen, Hui; Shana, Zhi-hua

    2010-06-01

    Cross-linking agents play an important part in the physical properties of collagen based biomaterials. This paper describes the stabilization of type I collagen using an oxazolidine E-resorcinol compound. It is shown by NMR and elemental analysis techniques that oxazolidine E undergoes ring opening to form an N-methylol intermediate form and then reacts with the hydrogen bonds of resorcinol. Oxazolidine E-resorcinol compound treated collagen fibers are shown by DSC analysis to be more thermally stable than simple oxazolidine E-resorcinol treated collagen. Treated collagen fibers showed shrinkage temperature around 98 degrees C implying that the oxazolidine E-resorcinol compounds impart thermal stability. Circular dichroism revealed that there is no major alteration in the structure of collagen after treatment with the compound. The study demonstrates that the involvement of hydrogen bonding and hydrophobic interaction as the principal mechanisms for stabilization of collagen by oxazolidine E-resorcinol compounds. Copyright 2010 Elsevier B.V. All rights reserved.

  9. [Bone Cell Biology Assessed by Microscopic Approach. Assessment of bone quality using Raman and infrared spectroscopy].

    Science.gov (United States)

    Suda, Hiromi Kimura

    2015-10-01

    Bone quality, which was defined as "the sum total of characteristics of the bone that influence the bone's resistance to fracture" at the National Institute of Health (NIH) conference in 2001, contributes to bone strength in combination with bone mass. Bone mass is often measured as bone mineral density (BMD) and, consequently, can be quantified easily. On the other hand, bone quality is composed of several factors such as bone structure, bone matrix, calcification degree, microdamage, and bone turnover, and it is not easy to obtain data for the various factors. Therefore, it is difficult to quantify bone quality. We are eager to develop new measurement methods for bone quality that make it possible to determine several factors associated with bone quality at the same time. Analytic methods based on Raman and FTIR spectroscopy have attracted a good deal of attention as they can provide a good deal of chemical information about hydroxyapatite and collagen, which are the main components of bone. A lot of studies on bone quality using Raman and FTIR imaging have been reported following the development of the two imaging systems. Thus, both Raman and FTIR imaging appear to be promising new bone morphometric techniques.

  10. Collagenase-resistant collagen promotes mouse aging and vascular cell senescence.

    Science.gov (United States)

    Vafaie, Faran; Yin, Hao; O'Neil, Caroline; Nong, Zengxuan; Watson, Alanna; Arpino, John-Michael; Chu, Michael W A; Wayne Holdsworth, David; Gros, Robert; Pickering, J Geoffrey

    2014-02-01

    Collagen fibrils become resistant to cleavage over time. We hypothesized that resistance to type I collagen proteolysis not only marks biological aging but also drives it. To test this, we followed mice with a targeted mutation (Col1a1(r/r) ) that yields collagenase-resistant type I collagen. Compared with wild-type littermates, Col1a1(r/r) mice had a shortened lifespan and developed features of premature aging including kyphosis, weight loss, decreased bone mineral density, and hypertension. We also found that vascular smooth muscle cells (SMCs) in the aortic wall of Col1a1(r/r) mice were susceptible to stress-induced senescence, displaying senescence-associated ß-galactosidase (SA-ßGal) activity and upregulated p16(INK4A) in response to angiotensin II infusion. To elucidate the basis of this pro-aging effect, vascular SMCs from twelve patients undergoing coronary artery bypass surgery were cultured on collagen derived from Col1a1(r/r) or wild-type mice. This revealed that mutant collagen directly reduced replicative lifespan and increased stress-induced SA-ßGal activity, p16(INK4A) expression, and p21(CIP1) expression. The pro-senescence effect of mutant collagen was blocked by vitronectin, a ligand for αvß3 integrin that is presented by denatured but not native collagen. Moreover, inhibition of αvß3 with echistatin or with αvß3-blocking antibody increased senescence of SMCs on wild-type collagen. These findings reveal a novel aging cascade whereby resistance to collagen cleavage accelerates cellular aging. This interplay between extracellular and cellular compartments could hasten mammalian aging and the progression of aging-related diseases. © 2013 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  11. Collagen type XV and the 'osteogenic status'.

    Science.gov (United States)

    Lisignoli, Gina; Lambertini, Elisabetta; Manferdini, Cristina; Gabusi, Elena; Penolazzi, Letizia; Paolella, Francesca; Angelozzi, Marco; Casagranda, Veronica; Piva, Roberta

    2017-09-01

    We have previously demonstrated that collagen type XV (ColXV) is a novel bone extracellular matrix (ECM) protein. It is well known that the complex mixture of multiple components present in ECM can help both to maintain stemness or to promote differentiation of stromal cells following change in qualitative characteristics or concentrations. We investigated the possible correlation between ColXV expression and mineral matrix deposition by human mesenchymal stromal cells (hMSCs) with different osteogenic potential and by osteoblasts (hOBs) that are able to grow in culture medium with or without calcium. Analysing the osteogenic process, we have shown that ColXV basal levels are lower in cells less prone to osteo-induction such as hMSCs from Wharton Jelly (hWJMSCs), compared to hMSCs that are prone to osteo-induction such as those from the bone marrow (hBMMSCs). In the group of samples identified as 'mineralized MSCs', during successful osteogenic induction, ColXV protein continued to be detected at substantial levels until early stage of differentiation, but it significantly decreased and then disappeared at the end of culture when the matrix formed was completely calcified. The possibility to grow hOBs in culture medium without calcium corroborated the results obtained with hMSCs demonstrating that calcium deposits organized in a calcified matrix, and not calcium 'per se', negatively affected ColXV expression. As a whole, our data suggest that ColXV may participate in ECM organization in the early-phases of the osteogenic process and that this is a prerequisite to promote the subsequent deposition of mineral matrix. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  12. Collagen-Coated Poly(lactide-co-glycolide/Hydroxyapatite Scaffold Incorporated with DGEA Peptide for Synergistic Repair of Skull Defect

    Directory of Open Access Journals (Sweden)

    Ming Bi

    2018-01-01

    Full Text Available The treatment of large-area bone defects remains a challenge; however, various strategies have been developed to improve the performances of scaffolds in bone tissue engineering. In this study, poly(lactide-co-glycolide/hydroxyapatite (PLGA/HA scaffold was coated with Asp-Gly-Glu-Ala (DGEA-incorporated collagen for the repair of rat skull defect. Our results indicated that the mechanical strength and hydrophilicity of the PLGA/HA scaffold were clearly improved and conducive to cell adhesion and proliferation. The collagen-coated scaffold with DGEA significantly promoted the repair of skull defect. These findings indicated that a combination of collagen coating and DGEA improved scaffold properties for bone regeneration, thereby providing a new potential strategy for scaffold design.

  13. Are there any positive effects of TNF-alpha blockers on bone metabolism?