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Sample records for bone repair materials

  1. Recent progress in injectable bone repair materials research

    NASA Astrophysics Data System (ADS)

    Chen, Zonggang; Zhang, Xiuli; Kang, Lingzhi; Xu, Fei; Wang, Zhaoling; Cui, Fu-Zhai; Guo, Zhongwu

    2015-12-01

    Minimally invasive injectable self-setting materials are useful for bone repairs and for bone tissue regeneration in situ. Due to the potential advantages of these materials, such as causing minimal tissue injury, nearly no influence on blood supply, easy operation and negligible postoperative pain, they have shown great promises and successes in clinical applications. It has been proposed that an ideal injectable bone repair material should have features similar to that of natural bones, in terms of both the microstructure and the composition, so that it not only provides adequate stimulus to facilitate cell adhesion, proliferation and differentiation but also offers a satisfactory biological environment for new bone to grow at the implantation site. This article reviews the properties and applications of injectable bone repair materials, including those that are based on natural and synthetic polymers, calcium phosphate, calcium phosphate/polymer composites and calcium sulfate, to orthopedics and bone tissue repairs, as well as the progress made in biomimetic fabrication of injectable bone repair materials.

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

    PubMed

    Almeida, J Carlos; Wacha, András; Gomes, Pedro S; Alves, Luís C; Fernandes, M Helena Vaz; Salvado, Isabel M Miranda; Fernandes, M Helena R

    2016-05-01

    The increasing interest in the effect of strontium in bone tissue repair has promoted the development of bioactive materials with strontium release capability. According to literature, hybrid materials based on the system PDMS-SiO2 have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS-SiO2-CaO-SrO, was prepared with the incorporation of 0.05 mol of titanium per mol of SiO2. Calcium and strontium were added using the respective acetates as sources, following a sol-gel technique previously developed by the present authors. The obtained samples were characterized by FT-IR, solid-state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studies were performed by immersion of the samples in Kokubo's SBF for different periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed samples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity. PMID:26952443

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

    PubMed

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

    2015-10-05

    We prepared a bone scaffold material comprising a PLGA/β-TCP core and a Type I collagen cladding, and recombined it with bone marrow stroma stem cells (BMSCs) to evaluate its potential for use in bone tissue engineering by in vivo and in vitro experiments. PLGA/β-TCP without a cladding was used for comparison. The adherence rate of the BMSCs to the scaffold was determined by cell counting. Cell proliferation rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The osteogenic capability was evaluated by alkaline phosphatase activity. The scaffold materials were recombined with the BMSCs and implanted into a large segmental rabbit radial defect model to evaluate defect repair. Osteogenesis was assessed in the scaffold materials by histological and double immunofluorescence labeling, etc. The adherence number, proliferation number, and alkaline phosphatase expression of the cells on the bone scaffold material with core-cladding structure were significantly higher than the corresponding values in the PLGA/β-TCP composite scaffold material (P < 0.05). An in vivo test indicated that the bone scaffold material with core-cladding structure completely degraded at the bone defect site and bone formation was completed. The rabbit large sentimental radial defect was successfully repaired. The degradation and osteogenesis rates matched well. The bone scaffold with core-cladding structure exhibited better osteogenic activity and capacity to repair a large segmental bone defect compared to the PLGA/β-TCP composite scaffold. The bone scaffold with core-cladding structure has excellent physical properties and biocompatibility. It is an ideal scaffold material for bone tissue engineering.

  4. Bone fracture repair - series (image)

    MedlinePlus

    The three main treatment options for bone fractures are: Casting Open reduction, and internal fixation- this involves a surgery to repair the fracture-frequently, metal rods, screws or plates are used to repair the ...

  5. Cell therapy for bone repair.

    PubMed

    Rosset, P; Deschaseaux, F; Layrolle, P

    2014-02-01

    When natural bone repair mechanisms fail, autologous bone grafting is the current standard of care. The osteogenic cells and bone matrix in the graft provide the osteo-inductive and osteo-conductive properties required for successful bone repair. Bone marrow (BM) mesenchymal stem cells (MSCs) can differentiate into osteogenic cells. MSC-based cell therapy holds promise for promoting bone repair. The amount of MSCs available from iliac-crest aspirates is too small to be clinically useful, and either concentration or culture must therefore be used to expand the MSC population. MSCs can be administered alone via percutaneous injection or implanted during open surgery with a biomaterial, usually biphasic hydroxyapatite/β-calcium-triphosphate granules. Encouraging preliminary results have been obtained in patients with delayed healing of long bone fractures or avascular necrosis of the femoral head. Bone tissue engineering involves in vitro MSC culturing on biomaterials to obtain colonisation of the biomaterial and differentiation of the cells. The biomaterial-cell construct is then implanted into the zone to be treated. Few published data are available on bone tissue engineering. Much work remains to be done before determining whether this method is suitable for the routine filling of bone tissue defects. Increasing cell survival and promoting implant vascularisation are major challenges. Improved expertise with culturing techniques, together with the incorporation of regulatory requirements, will open the way to high-quality clinical trials investigating the usefulness of cell therapy as a method for achieving bone repair. Cell therapy avoids the drawbacks of autologous bone grafting, preserving the bone stock and diminishing treatment invasiveness.

  6. Repair of tegmen defect using cranial particulate bone graft.

    PubMed

    Greene, Arin K; Poe, Dennis S

    2015-01-01

    Bone paté is used to repair cranial bone defects. This material contains bone-dust collected during the high-speed burring of the cranium. Clinical and experimental studies of bone dust, however, have shown that it does not have biological activity and is resorbed. We describe the use of bone paté using particulate bone graft. Particulate graft is harvested with a hand-driven brace and 16mm bit; it is not subjected to thermal injury and its large size resists resorption. Bone paté containing particulate graft is much more likely than bone dust to contain viable osteoblasts capable of producing new bone.

  7. Dental materials for cleft palate repair.

    PubMed

    Sharif, Faiza; Ur Rehman, Ihtesham; Muhammad, Nawshad; MacNeil, Sheila

    2016-04-01

    Numerous bone and soft tissue grafting techniques are followed to repair cleft of lip and palate (CLP) defects. In addition to the gold standard surgical interventions involving the use of autogenous grafts, various allogenic and xenogenic graft materials are available for bone regeneration. In an attempt to discover minimally invasive and cost effective treatments for cleft repair, an exceptional growth in synthetic biomedical graft materials have occurred. This study gives an overview of the use of dental materials to repair cleft of lip and palate (CLP). The eligibility criteria for this review were case studies, clinical trials and retrospective studies on the use of various types of dental materials in surgical repair of cleft palate defects. Any data available on the surgical interventions to repair alveolar or palatal cleft, with natural or synthetic graft materials was included in this review. Those datasets with long term clinical follow-up results were referred to as particularly relevant. The results provide encouraging evidence in favor of dental and other related biomedical materials to fill the gaps in clefts of lip and palate. The review presents the various bones and soft tissue replacement strategies currently used, tested or explored for the repair of cleft defects. There was little available data on the use of synthetic materials in cleft repair which was a limitation of this study. In conclusion although clinical trials on the use of synthetic materials are currently underway the uses of autologous implants are the preferred treatment methods to date.

  8. Osteoconductive carriers for integrated bone repair

    PubMed Central

    Ganey, Timothy; Hutton, William; Meisel, Hans Jörg

    2009-01-01

    Successful bone repair is judged in achieving restitution of space and mechanical integrity, and in regaining function. When the biology or anatomy are insufficient to attain a full repair, therapeutic use of graft material has been used to omit compliance features such as strain tolerance, reduced stiffness, and attenuated strength, and instead promote primary or membranous-type bone formation within the physical approximation of a graft material. The challenge of most conductive materials is that they emerge from a static platform and in placement force the living system to adapt to placement, dimension, different properties, and eventually are only successful in degradation and replacement, or in integration. The synergy and interdependency between adhesion, ECM, and proteolysis are important concepts that must be understood to engineer scaffolds capable of holding up to standards which are more than cell decoration. Moreover, the reactive specificity to loading, degradation, therapeutic delivery during absorption remains a key aim of both academic and industrial designs. Achieving conductivity comes with challenges of best fit integration, delivery, and in integrated modeling. The more liquid is the delivery, the more modular the components, and adaptive the matrix to meeting the intended application, the more likely that the conductivity will not be excluded by the morphology of the injury site. Considerations for osteoconductive materials for bone repair and replacement have developed conceptually and advanced parallel with a better understanding of not only bone biology but of materials science. First models of material replacements utilized a reductionist-constructionist logic; define the constituents of the material in terms of its morphology and chemical composition, and then engineer material with similar content and properties as a means of accommodating a replacement. Unfortunately for biologic systems, empiric formulation is insufficient to promote

  9. Effect of resorption rate and osteoconductivity of biodegradable calcium phosphate materials on the acquisition of natural bone strength in the repaired bone.

    PubMed

    Chiba, Shinpei; Anada, Takahisa; Suzuki, Kentaro; Saito, Keisuke; Shiwaku, Yukari; Miyatake, Naohisa; Baba, Kazuyoshi; Imaizumi, Hideki; Hosaka, Masami; Itoi, Eiji; Suzuki, Osamu

    2016-11-01

    The purpose of this study was to compare the biodegradation rate and quality of regenerated bone among four materials. A short time period of 8 weeks was chosen to examine early bone healing. The rod-shaped implants of commercially available two β-tricalcium phosphate (β-TCP) ceramics with porosity 60% and 71-80%, respectively, laboratory prepared octacalcium phosphate/gelatin composite (OCP/Gel), which has been proven to have a highly osteoconductive and biodegradable property in rat calvarial defect, and gelatin sponge (Gelatin) were implanted in rabbit tibia defect of 6 mm diameter and 7 mm depth for 2, 4 and 8 weeks. Analyses by μCT, histomorphometry and push-in test were carried out to evaluate the extent of the tissue regeneration and the material biodegradation in the long bone. OCP/Gel and Gelatin were completely resorbed but only OCP/Gel induced cortical bone bridge until 8 weeks that has strength compatible to that of the natural bone. β-TCP (71%-80%) and β-TCP (60%) were not completely resorbed and never induced the amount of new bone formation beyond that by OCP/Gel. The results indicate that the new bone having enough strength could be regenerated if the material shows not only higher biodegradation rate but also higher osteoconductivity. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2833-2842, 2016.

  10. The role of pleiotrophin in bone repair.

    PubMed

    Lamprou, Margarita; Kaspiris, Angelos; Panagiotopoulos, Elias; Giannoudis, Peter V; Papadimitriou, Evangelia

    2014-12-01

    Bone has an enormous capacity for growth, regeneration, and remodelling, largely due to induction of osteoblasts that are recruited to the site of bone formation. Although the pathways involved have not been fully elucidated, it is well accepted that the immediate environment of the cells is likely to play a role via cell–matrix interactions, mediated by several growth factors. Formation of new blood vessels is also significant and interdependent to bone formation, suggesting that enhancement of angiogenesis could be beneficial during the process of bone repair. Pleiotrophin (PTN), also called osteoblast-specific factor 1, is a heparin-binding angiogenic growth factor, with a well-defined and significant role in both physiological and pathological angiogenesis. In this review we summarise the existing evidence on the role of PTN in bone repair.

  11. Scaffold-based Anti-infection Strategies in Bone Repair

    PubMed Central

    Johnson, Christopher T.; García, Andrés J.

    2014-01-01

    Bone fractures and non-union defects often require surgical intervention where biomaterials are used to correct the defect, and approximately 10% of these procedures are compromised by bacterial infection. Currently, treatment options are limited to sustained, high doses of antibiotics and surgical debridement of affected tissue, leaving a significant, unmet need for the development of therapies to combat device-associated biofilm and infections. Engineering implants to prevent infection is a desirable material characteristic. Tissue engineered scaffolds for bone repair provide a means to both regenerate bone and serve as a base for adding antimicrobial agents. Incorporating anti-infection properties into regenerative medicine therapies could improve clinical outcomes and reduce the morbidity and mortality associated with biomaterial implant-associated infections. This review focuses on current animal models and technologies available to assess bone repair in the context of infection, antimicrobial agents to fight infection, the current state of antimicrobial scaffolds, and future directions in the field. PMID:25476163

  12. Scaffold-based anti-infection strategies in bone repair.

    PubMed

    Johnson, Christopher T; García, Andrés J

    2015-03-01

    Bone fractures and non-union defects often require surgical intervention where biomaterials are used to correct the defect, and approximately 10% of these procedures are compromised by bacterial infection. Currently, treatment options are limited to sustained, high doses of antibiotics and surgical debridement of affected tissue, leaving a significant, unmet need for the development of therapies to combat device-associated biofilm and infections. Engineering implants to prevent infection is a desirable material characteristic. Tissue engineered scaffolds for bone repair provide a means to both regenerate bone and serve as a base for adding antimicrobial agents. Incorporating anti-infection properties into regenerative medicine therapies could improve clinical outcomes and reduce the morbidity and mortality associated with biomaterial implant-associated infections. This review focuses on current animal models and technologies available to assess bone repair in the context of infection, antimicrobial agents to fight infection, the current state of antimicrobial scaffolds, and future directions in the field.

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

    PubMed

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

    1989-01-01

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

  14. Improved repair of bone defects with prevascularized tissue-engineered bones constructed in a perfusion bioreactor.

    PubMed

    Li, De-Qiang; Li, Ming; Liu, Pei-Lai; Zhang, Yuan-Kai; Lu, Jian-Xi; Li, Jian-Min

    2014-10-01

    Vascularization of tissue-engineered bones is critical to achieving satisfactory repair of bone defects. The authors investigated the use of prevascularized tissue-engineered bone for repairing bone defects. The new bone was greater in the prevascularized group than in the non-vascularized group, indicating that prevascularized tissue-engineered bone improves the repair of bone defects. [Orthopedics. 2014; 37(10):685-690.].

  15. Effect of collagen sponge and fibrin glue on bone repair

    PubMed Central

    SANTOS, Thiago de Santana; ABUNA, Rodrigo Paolo Flores; de ALMEIDA, Adriana Luisa Gonçalves; BELOTI, Marcio Mateus; ROSA, Adalberto Luiz

    2015-01-01

    ABSTRACT The ability of hemostatic agents to promote bone repair has been investigated using in vitro and in vivo models but, up to now, the results are inconclusive. Objective In this context, the aim of this study was to compare the potential of bone repair of collagen sponge with fibrin glue in a rat calvarial defect model. Material and Methods Defects of 5 mm in diameter were created in rat calvariae and treated with either collagen sponge or fibrin glue; untreated defects were used as control. At 4 and 8 weeks, histological analysis and micro-CT-based histomorphometry were carried out and data were compared by two-way ANOVA followed by Student-Newman-Keuls test when appropriated (p≤0.05). Results Three-dimensional reconstructions showed increased bone formation in defects treated with either collagen sponge or fibrin glue compared with untreated defects, which was confirmed by the histological analysis. Morphometric parameters indicated the progression of bone formation from 4 to 8 weeks. Additionally, fibrin glue displayed slightly higher bone formation rate when compared with collagen sponge. Conclusion Our results have shown the benefits of using collagen sponge and fibrin glue to promote new bone formation in rat calvarial bone defects, the latter being discreetly more advantageous. PMID:26814464

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

    PubMed

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

    2015-12-01

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

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

    PubMed

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

    2015-12-01

    Bone substitutes are used in wide range of orthopaedic application. An ideal bone substitute should exhibit superior osteoinductive and osteoconductive properties. Neither bio-derived materials nor synthetic materials can meet the needs of an ideal bone substitute. Preparation of composite materials is a promising way to improve properties of biomaterial. In this study, the porous poly lactic acid (PLA)/demineralized bone matrix (DBM) composite biomaterials prepared by supercritical CO2 technique were implanted to repair rabbit radius segmental bone defect. By comparing with PLA and bone autograft, the X-ray result and histological analysis showed the repair effect of PLA/DBM porous composite materials is significantly better than that of the PLA group and the blank control group, and is similar to autologous bone. The PLA/DBM can promote the healing of bone defects and can be used as a kind of ideal alternative materials to repair bone defects. PMID:25904497

  18. A novel porous gelatin composite containing naringin for bone repair.

    PubMed

    Chen, Kuo-Yu; Lin, Kuen-Cherng; Chen, Yueh-Sheng; Yao, Chun-Hsu

    2013-01-01

    As Gu-Sui-Bu (GSB) is a commonly used Chinese medical herb for therapeutic treatment of bone-related diseases, naringin is its main active component. This study elucidates how various concentrations of naringin solution affect the activities of bone cells, based on colorimetric, alkaline phosphatase activity, nodule formation, and tartrate-resistant acid phosphatase activity assays to determine the optimal concentration of naringin. GGT composite was obtained by combining genipin cross-linked gelatin and β-tricalcium phosphate. GGTN composite was prepared by mixing GGT composite with the predetermined concentration of naringin. Porous GGT and GGTN composites were then made using a salt-leaching procedure. The potential of the composites in repairing bone defects was evaluated and compared in vivo by using the biological response of rabbit calvarial bone to these composites. Consequently, the most effective concentration of naringin was 10 mg/mL, which significantly enhanced the proliferation of osteoblasts, osteoclast activity, and nodule formation without affecting the alkaline phosphatase activity of osteoblasts and mitochondrial activity of mixed-bone cells. Radiographic analysis revealed greater new bone ingrowth in the GGTN composite than in the GGT composite at the same implantation time. Therefore, the GGTN composite is highly promising for use as a bone graft material.

  19. The Challenge and the Promise of Bone Marrow Cells for Human Cartilage Repair

    PubMed Central

    2015-01-01

    The cartilage repair potential of bone marrow–derived stem cells has been well described. Harnessing this potential for human articular cartilage repair remains challenging. Accessing bone marrow repair cells through marrow stimulation techniques such as microfracture is readily achieved with generally good but inconsistent results. Animal and human studies show feasibility for ex vivo processing of bone marrow to isolate, concentrate, and culture mesenchymal stem cells. Nevertheless, it has been difficult to show consistent and clinically meaningful improvement using bone marrow cell preparations above what has been achieved with microfracture. Consequently, microfracture continues to be the simplest and most commonly used method to enhance repair of focal articular cartilage defects. Emerging preclinical work in the equine model suggests a role for enhancing marrow-stimulation techniques through the use of natural scaffolds such as autologous platelet enriched fibrin as well as optimization of joint biology through localized gene therapy to support cartilage repair. In contrast to joint replacement where inert materials of known mechanical properties are used, host biology determines the relative success, failure, and durability of cartilage repair. As such, development of personalized strategies to improve the quality and durability of bone marrow cell–based articular cartilage repair represent exciting new areas of inquiry. Continued advances in stem cell biology, scaffold technologies, and methods to delineate and enhance host biology, both systemically and within the joint, hold promise for harnessing the full power of bone marrow cells to facilitate cartilage repair and regeneration. PMID:27340515

  20. Biomaterial-mediated strategies targeting vascularization for bone repair.

    PubMed

    García, José R; García, Andrés J

    2016-04-01

    Repair of non-healing bone defects through tissue engineering strategies remains a challenging feat in the clinic due to the aversive microenvironment surrounding the injured tissue. The vascular damage that occurs following a bone injury causes extreme ischemia and a loss of circulating cells that contribute to regeneration. Tissue-engineered constructs aimed at regenerating the injured bone suffer from complications based on the slow progression of endogenous vascular repair and often fail at bridging the bone defect. To that end, various strategies have been explored to increase blood vessel regeneration within defects to facilitate both tissue-engineered and natural repair processes. Developments that induce robust vascularization will need to consolidate various parameters including optimization of embedded therapeutics, scaffold characteristics, and successful integration between the construct and the biological tissue. This review provides an overview of current strategies as well as new developments in engineering biomaterials to induce reparation of a functional vascular supply in the context of bone repair.

  1. Repairing Fractured Bones by Use of Bioabsorbable Composites

    NASA Technical Reports Server (NTRS)

    Farley, Gary L.

    2006-01-01

    A proposed method of surgical repair of fractured bones would incorporate recent and future advances in the art of composite materials. The composite materials used in this method would be biocompatible and at least partly bioabsorbable: that is, during the healing process following surgery, they would be wholly or at least partly absorbed into the bones and other tissues in which they were implanted. Relative to the traditional method, the proposed method would involve less surgery, pose less of a risk of infection, provide for better transfer of loads across fracture sites, and thereby promote better healing while reducing the need for immobilization by casts and other external devices. One requirement that both the traditional and proposed methods must satisfy is to fix the multiple segments of a broken bone in the correct relative positions. Mechanical fixing techniques used in the traditional method include the use of plates spanning the fracture site and secured to the bone by screws, serving of wire along the bone across the fracture site, insertion of metallic intramedullary rods through the hollow portion of the fractured bone, and/or inserting transverse rods through the bone, muscle, and skin to stabilize the fractured members. After the bone heals, a second surgical operation is needed to remove the mechanical fixture(s). In the proposed method, there would be no need for a second surgical operation. The proposed method is based partly on the observation that in the fabrication of a structural member, it is generally more efficient and reliable to use multiple small fasteners to transfer load across a joint than to use a single or smaller number of larger fasteners, provided that the stress fields of neighboring small fasteners do not overlap or interact. Also, multiple smaller fasteners are more reliable than are larger and fewer fasteners. However, there is a trade-off between structural efficiency and the cost of insertion time and materials. The

  2. Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction

    PubMed Central

    Shah, Nisarg J.; Hyder, Md. Nasim; Quadir, Mohiuddin A.; Dorval Courchesne, Noémie-Manuelle; Seeherman, Howard J.; Nevins, Myron; Spector, Myron; Hammond, Paula T.

    2014-01-01

    Traumatic wounds and congenital defects that require large-scale bone tissue repair have few successful clinical therapies, particularly for craniomaxillofacial defects. Although bioactive materials have demonstrated alternative approaches to tissue repair, an optimized materials system for reproducible, safe, and targeted repair remains elusive. We hypothesized that controlled, rapid bone formation in large, critical-size defects could be induced by simultaneously delivering multiple biological growth factors to the site of the wound. Here, we report an approach for bone repair using a polyelectrolye multilayer coating carrying as little as 200 ng of bone morphogenetic protein-2 and platelet-derived growth factor-BB that were eluted over readily adapted time scales to induce rapid bone repair. Based on electrostatic interactions between the polymer multilayers and growth factors alone, we sustained mitogenic and osteogenic signals with these growth factors in an easily tunable and controlled manner to direct endogenous cell function. To prove the role of this adaptive release system, we applied the polyelectrolyte coating on a well-studied biodegradable poly(lactic-co-glycolic acid) support membrane. The released growth factors directed cellular processes to induce bone repair in a critical-size rat calvaria model. The released growth factors promoted local bone formation that bridged a critical-size defect in the calvaria as early as 2 wk after implantation. Mature, mechanically competent bone regenerated the native calvaria form. Such an approach could be clinically useful and has significant benefits as a synthetic, off-the-shelf, cell-free option for bone tissue repair and restoration. PMID:25136093

  3. Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction.

    PubMed

    Shah, Nisarg J; Hyder, Md Nasim; Quadir, Mohiuddin A; Dorval Courchesne, Noémie-Manuelle; Seeherman, Howard J; Nevins, Myron; Spector, Myron; Hammond, Paula T

    2014-09-01

    Traumatic wounds and congenital defects that require large-scale bone tissue repair have few successful clinical therapies, particularly for craniomaxillofacial defects. Although bioactive materials have demonstrated alternative approaches to tissue repair, an optimized materials system for reproducible, safe, and targeted repair remains elusive. We hypothesized that controlled, rapid bone formation in large, critical-size defects could be induced by simultaneously delivering multiple biological growth factors to the site of the wound. Here, we report an approach for bone repair using a polyelectrolye multilayer coating carrying as little as 200 ng of bone morphogenetic protein-2 and platelet-derived growth factor-BB that were eluted over readily adapted time scales to induce rapid bone repair. Based on electrostatic interactions between the polymer multilayers and growth factors alone, we sustained mitogenic and osteogenic signals with these growth factors in an easily tunable and controlled manner to direct endogenous cell function. To prove the role of this adaptive release system, we applied the polyelectrolyte coating on a well-studied biodegradable poly(lactic-co-glycolic acid) support membrane. The released growth factors directed cellular processes to induce bone repair in a critical-size rat calvaria model. The released growth factors promoted local bone formation that bridged a critical-size defect in the calvaria as early as 2 wk after implantation. Mature, mechanically competent bone regenerated the native calvaria form. Such an approach could be clinically useful and has significant benefits as a synthetic, off-the-shelf, cell-free option for bone tissue repair and restoration.

  4. Skeletal Blood Flow in Bone Repair and Maintenance

    PubMed Central

    Tomlinson, Ryan E.; Silva, Matthew J.

    2013-01-01

    Bone is a highly vascularized tissue, although this aspect of bone is often overlooked. In this article, the importance of blood flow in bone repair and regeneration will be reviewed. First, the skeletal vascular anatomy, with an emphasis on long bones, the distinct mechanisms for vascularizing bone tissue, and methods for remodeling existing vasculature are discussed. Next, techniques for quantifying bone blood flow are briefly summarized. Finally, the body of experimental work that demonstrates the role of bone blood flow in fracture healing, distraction osteogenesis, osteoporosis, disuse osteopenia, and bone grafting is examined. These results illustrate that adequate bone blood flow is an important clinical consideration, particularly during bone regeneration and in at-risk patient groups. PMID:26273509

  5. Toll-Like Receptor 4 Mediates the Regenerative Effects of Bone Grafts for Calvarial Bone Repair

    PubMed Central

    Wang, Dan; Gilbert, James R.; Shaw, Melissa A.; Shakir, Sameer; Losee, Joseph E.; Billiar, Timothy R.

    2015-01-01

    Craniofacial trauma is difficult to repair and presents a significant burden to the healthcare system. The inflammatory response following bone trauma is critical to initiate healing, serving to recruit inflammatory and progenitor cells and to promote angiogenesis. A role for inflammation in graft-induced bone regeneration has been suggested, but is still not well understood. The current study assessed the impact of Toll-like receptor (TLR4) signaling on calvarial repair in the presence of morselized bone components. Calvarial defects in wild-type and global TLR4−/− knockout mouse strains were treated with fractionated bone components in the presence or absence of a TLR4 neutralizing peptide. Defect healing was subsequently evaluated over 28 days by microcomputed tomography and histology. The matrix-enriched fraction of morselized bone stimulated calvarial bone repair comparably with intact bone graft, although the capacity for grafts to induce calvarial bone repair was significantly diminished by inhibition or genetic ablation of TLR4. Overall, our findings suggest that the matrix component of bone graft stimulates calvarial bone repair in a TLR4-dependent manner. These results support the need to better understand the role of inflammation in the design and implementation of strategies to improve bone healing. PMID:25603990

  6. Toll-like receptor 4 mediates the regenerative effects of bone grafts for calvarial bone repair.

    PubMed

    Wang, Dan; Gilbert, James R; Shaw, Melissa A; Shakir, Sameer; Losee, Joseph E; Billiar, Timothy R; Cooper, Gregory M

    2015-04-01

    Craniofacial trauma is difficult to repair and presents a significant burden to the healthcare system. The inflammatory response following bone trauma is critical to initiate healing, serving to recruit inflammatory and progenitor cells and to promote angiogenesis. A role for inflammation in graft-induced bone regeneration has been suggested, but is still not well understood. The current study assessed the impact of Toll-like receptor (TLR4) signaling on calvarial repair in the presence of morselized bone components. Calvarial defects in wild-type and global TLR4(-/-) knockout mouse strains were treated with fractionated bone components in the presence or absence of a TLR4 neutralizing peptide. Defect healing was subsequently evaluated over 28 days by microcomputed tomography and histology. The matrix-enriched fraction of morselized bone stimulated calvarial bone repair comparably with intact bone graft, although the capacity for grafts to induce calvarial bone repair was significantly diminished by inhibition or genetic ablation of TLR4. Overall, our findings suggest that the matrix component of bone graft stimulates calvarial bone repair in a TLR4-dependent manner. These results support the need to better understand the role of inflammation in the design and implementation of strategies to improve bone healing.

  7. Repair material properties for effective structural application

    SciTech Connect

    Mangat, P.S.; Limbachiya, M.C.

    1997-04-01

    Strength and engineering properties of three generic repair materials which are likely to influence long-term performance of repaired concrete structures were studied. Measured properties include strength, stiffness, shrinkage and creep deformations, together with the complete compressive stress-strain characteristics including post-cracking behavior. The repair materials considered in this investigation are commercially available and widely used. These included a high performance non-shrinkable concrete, a mineral based cementitious material with no additives or coarse aggregate size particles, and a cementitious mortar containing styrene acrylic copolymer with fiber additives. Performance comparisons are also made between these materials and plain concrete mixes of similar strength and stiffness, suitable for repair applications. The results show that shrinkage of the repair materials was significantly greater than the shrinkage of normal concrete. Moreover, the shrinkage of those modified with a polymer admixture was found to be very sensitive to the relative humidity of the exposure compared to normal concrete. The post-peak strain capacity of the material modified with a polymer admixture was markedly improved leading to a more pronounced falling branch of stress-strain curve. The ultimate stress level (at a maximum load) of specially formulated repair materials varies significantly, the lowest ultimate stress being recorded for the porous mineral-based material. The inclusion of aggregates improves the mechanical properties and dimensional stability of repair materials.

  8. Is bone transplantation the gold standard for repair of alveolar bone defects?

    PubMed

    Raposo-Amaral, Cassio Eduardo; Bueno, Daniela Franco; Almeida, Ana Beatriz; Jorgetti, Vanda; Costa, Cristiane Cabral; Gouveia, Cecília Helena; Vulcano, Luiz Carlos; Fanganiello, Roberto D; Passos-Bueno, Maria Rita; Alonso, Nivaldo

    2014-01-01

    New strategies to fulfill craniofacial bone defects have gained attention in recent years due to the morbidity of autologous bone graft harvesting. We aimed to evaluate the in vivo efficacy of bone tissue engineering strategy using mesenchymal stem cells associated with two matrices (bovine bone mineral and α-tricalcium phosphate), compared to an autologous bone transfer. A total of 28 adult, male, non-immunosuppressed Wistar rats underwent a critical-sized osseous defect of 5 mm diameter in the alveolar region. Animals were divided into five groups. Group 1 (n = 7) defects were repaired with autogenous bone grafts; Group 2 (n = 5) defects were repaired with bovine bone mineral free of cells; Group 3 (n = 5) defects were repaired with bovine bone mineral loaded with mesenchymal stem cells; Group 4 (n = 5) defects were repaired with α-tricalcium phosphate free of cells; and Group 5 (n = 6) defects were repaired with α-tricalcium phosphate loaded with mesenchymal stem cells. Groups 2-5 were compared to Group 1, the reference group. Healing response was evaluated by histomorphometry and computerized tomography. Histomorphometrically, Group 1 showed 60.27% ± 16.13% of bone in the defect. Groups 2 and 3 showed 23.02% ± 8.6% (p = 0.01) and 38.35% ± 19.59% (p = 0.06) of bone in the defect, respectively. Groups 4 and 5 showed 51.48% ± 11.7% (p = 0.30) and 61.80% ± 2.14% (p = 0.88) of bone in the defect, respectively. Animals whose bone defects were repaired with α-tricalcium phosphate and mesenchymal stem cells presented the highest bone volume filling the defects; both were not statistically different from autogenous bone. PMID:24551445

  9. Is bone transplantation the gold standard for repair of alveolar bone defects?

    PubMed Central

    Raposo-Amaral, Cassio Eduardo; Bueno, Daniela Franco; Almeida, Ana Beatriz; Jorgetti, Vanda; Costa, Cristiane Cabral; Gouveia, Cecília Helena; Vulcano, Luiz Carlos; Fanganiello, Roberto D; Passos-Bueno, Maria Rita

    2014-01-01

    New strategies to fulfill craniofacial bone defects have gained attention in recent years due to the morbidity of autologous bone graft harvesting. We aimed to evaluate the in vivo efficacy of bone tissue engineering strategy using mesenchymal stem cells associated with two matrices (bovine bone mineral and α-tricalcium phosphate), compared to an autologous bone transfer. A total of 28 adult, male, non-immunosuppressed Wistar rats underwent a critical-sized osseous defect of 5 mm diameter in the alveolar region. Animals were divided into five groups. Group 1 (n = 7) defects were repaired with autogenous bone grafts; Group 2 (n = 5) defects were repaired with bovine bone mineral free of cells; Group 3 (n = 5) defects were repaired with bovine bone mineral loaded with mesenchymal stem cells; Group 4 (n = 5) defects were repaired with α-tricalcium phosphate free of cells; and Group 5 (n = 6) defects were repaired with α-tricalcium phosphate loaded with mesenchymal stem cells. Groups 2–5 were compared to Group 1, the reference group. Healing response was evaluated by histomorphometry and computerized tomography. Histomorphometrically, Group 1 showed 60.27% ± 16.13% of bone in the defect. Groups 2 and 3 showed 23.02% ± 8.6% (p = 0.01) and 38.35% ± 19.59% (p = 0.06) of bone in the defect, respectively. Groups 4 and 5 showed 51.48% ± 11.7% (p = 0.30) and 61.80% ± 2.14% (p = 0.88) of bone in the defect, respectively. Animals whose bone defects were repaired with α-tricalcium phosphate and mesenchymal stem cells presented the highest bone volume filling the defects; both were not statistically different from autogenous bone. PMID:24551445

  10. Is bone transplantation the gold standard for repair of alveolar bone defects?

    PubMed

    Raposo-Amaral, Cassio Eduardo; Bueno, Daniela Franco; Almeida, Ana Beatriz; Jorgetti, Vanda; Costa, Cristiane Cabral; Gouveia, Cecília Helena; Vulcano, Luiz Carlos; Fanganiello, Roberto D; Passos-Bueno, Maria Rita; Alonso, Nivaldo

    2014-01-01

    New strategies to fulfill craniofacial bone defects have gained attention in recent years due to the morbidity of autologous bone graft harvesting. We aimed to evaluate the in vivo efficacy of bone tissue engineering strategy using mesenchymal stem cells associated with two matrices (bovine bone mineral and α-tricalcium phosphate), compared to an autologous bone transfer. A total of 28 adult, male, non-immunosuppressed Wistar rats underwent a critical-sized osseous defect of 5 mm diameter in the alveolar region. Animals were divided into five groups. Group 1 (n = 7) defects were repaired with autogenous bone grafts; Group 2 (n = 5) defects were repaired with bovine bone mineral free of cells; Group 3 (n = 5) defects were repaired with bovine bone mineral loaded with mesenchymal stem cells; Group 4 (n = 5) defects were repaired with α-tricalcium phosphate free of cells; and Group 5 (n = 6) defects were repaired with α-tricalcium phosphate loaded with mesenchymal stem cells. Groups 2-5 were compared to Group 1, the reference group. Healing response was evaluated by histomorphometry and computerized tomography. Histomorphometrically, Group 1 showed 60.27% ± 16.13% of bone in the defect. Groups 2 and 3 showed 23.02% ± 8.6% (p = 0.01) and 38.35% ± 19.59% (p = 0.06) of bone in the defect, respectively. Groups 4 and 5 showed 51.48% ± 11.7% (p = 0.30) and 61.80% ± 2.14% (p = 0.88) of bone in the defect, respectively. Animals whose bone defects were repaired with α-tricalcium phosphate and mesenchymal stem cells presented the highest bone volume filling the defects; both were not statistically different from autogenous bone.

  11. Minimally invasive repair of meta-bones.

    PubMed

    Piras, Alessandro; Guerrero, Tomás G

    2012-09-01

    Metacarpal and metatarsal fractures are common injuries in small animals and, in most of the cases, can be treated by minimally invasive techniques. Bone plates applied through epi-periosteal tunnels can stabilize meta-bones. Meta-bones III and IV are stabilized by dorsally applied plates. Meta-bones II and V are stabilized using plates applied medially and laterally. The scarcity of soft tissue coverage and the simple anatomy of meta-bones make these fractures amenable to fixation by using minimally invasive techniques. This practice should reduce morbidity and enhance healing time.

  12. Hierarchical Structure and Repair of Bone: Deformation, Remodelling, Healing

    NASA Astrophysics Data System (ADS)

    Fratzl, Peter; Weinkamer, Richard

    The design of natural materials follows a radically different paradigm as compared to engineering materials: organs are growing rather than being fabricated. As a main consequence, adaptation to changing conditions remains possible during the whole lifetime of a biological material. As a typical example of such a biological material, bone is constantly laid down by bone forming cells, osteoblasts, and removed by bone resorbing cells, osteoclasts. With this remodelling cycle of bone resorption and formation, the skeleton is able to adapt to changing needs at all levels of structural hierarchy. The hierarchical structure of bone is summarized in the second part of this chapter.

  13. Biomimetic strategies for bone repair and regeneration.

    PubMed

    Raucci, Maria G; Guarino, Vincenzo; Ambrosio, Luigi

    2012-01-01

    The osseointegration rate of implants is related to their composition and surface roughness. Implant roughness favors both bone anchoring and biomechanical stability. Osteoconductive calcium phosphate (Ca-P) coatings promote bone healing and apposition, leading to the rapid biological fixation of implants. It has been clearly shown in many publications that Ca-P coating accelerates bone formation around the implant. This review discusses two main routes for the manufacturing of polymer-based osteoconductive scaffolds for tissue engineering, namely the incorporation of bioceramic particles in the scaffold and the coating of a scaffold with a thin layer of apatite through a biomimetic process.

  14. Biomimetic Strategies for Bone Repair and Regeneration

    PubMed Central

    Raucci, Maria G.; Guarino, Vincenzo; Ambrosio, Luigi

    2012-01-01

    The osseointegration rate of implants is related to their composition and surface roughness. Implant roughness favors both bone anchoring and biomechanical stability. Osteoconductive calcium phosphate (Ca-P) coatings promote bone healing and apposition, leading to the rapid biological fixation of implants. It has been clearly shown in many publications that Ca-P coating accelerates bone formation around the implant. This review discusses two main routes for the manufacturing of polymer-based osteoconductive scaffolds for tissue engineering, namely the incorporation of bioceramic particles in the scaffold and the coating of a scaffold with a thin layer of apatite through a biomimetic process. PMID:24955638

  15. Bone tissue engineering and repair by gene therapy.

    PubMed

    Betz, Volker M; Betz, Oliver B; Harris, Mitchel B; Vrahas, Mark S; Evans, Christopher H

    2008-01-01

    Many clinical conditions require the stimulation of bone growth. The use of recombinant bone morphogenetic proteins does not provide a satisfying solution to these conditions due to delivery problems and high cost. Gene therapy has emerged as a very promising approach for bone repair that overcomes limitations of protein-based therapy. Several preclinical studies have shown that gene transfer technology has the ability to deliver osteogenic molecules to precise anatomical locations at therapeutic levels for sustained periods of time. Both in-vivo and ex-vivo transduction of cells can induce bone formation at ectopic and orthotopic sites. Genetic engineering of adult stem cells from various sources with osteogenic genes has led to enhanced fracture repair, spinal fusion and rapid healing of bone defects in animal models. This review describes current viral and non-viral gene therapy strategies for bone tissue engineering and repair including recent work from the author's laboratory. In addition, the article discusses the potential of gene-enhanced tissue engineering to enter widespread clinical use.

  16. Biology and augmentation of tendon-bone insertion repair

    PubMed Central

    2010-01-01

    Surgical reattachment of tendon and bone such as in rotator cuff repair, patellar-patella tendon repair and anterior cruciate ligament (ACL) reconstruction often fails due to the failure of regeneration of the specialized tissue ("enthesis") which connects tendon to bone. Tendon-to-bone healing taking place between inhomogenous tissues is a slow process compared to healing within homogenous tissue, such as tendon to tendon or bone to bone healing. Therefore special attention must be paid to augment tendon to bone insertion (TBI) healing. Apart from surgical fixation, biological and biophysical interventions have been studied aiming at regeneration of TBI healing complex, especially the regeneration of interpositioned fibrocartilage and new bone at the healing junction. This paper described the biology and the factors influencing TBI healing using patella-patellar tendon (PPT) healing and tendon graft to bone tunnel healing in ACL reconstruction as examples. Recent development in the improvement of TBI healing and directions for future studies were also reviewed and discussed. PMID:20727196

  17. Method of tissue repair using a composite material

    DOEpatents

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

    2014-03-18

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

  18. Method of tissue repair using a composite material

    DOEpatents

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

    2016-03-01

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

  19. Cancellous bone repair using bovine trabecular bone matrix particulates.

    PubMed

    Mushipe, M T; Revell, P A; Shelton, J C

    2002-01-01

    At 5 and 15 weeks post-surgery, biomechanical and histological analyses of cancellous bone defects filled with the bovine trabecular bone matrix (BBM) and hydroxyapatite (Hap) particulates of dimensions 106-150 microm were investigated. It was observed that at 5 weeks post-surgery the stiffness properties of the BBM filled defects were significantly higher than those observed in the Hap filled defects (p < 0.01) but comparable to those recorded in intact cancellous bone from the same anatomical position. Histologically, no significant differences were observed in the percentage of new bone contact with the particles. The biomechanical properties of the Hap filled defects mirrored those in intact cancellous bone only at 15 weeks post-surgery. BBM particles thus appeared to accelerate the early healing of osteotomies. It is therefore suggested that particles of this bioceramic be the subject of intense research for more usage in both periodontal osseous defects and orthopaedic fractures.

  20. Stem cell-based therapies for bone repair.

    PubMed

    Milner, Peter I; Clegg, Peter D; Stewart, Matthew C

    2011-08-01

    This article provides an overview of the cellular and molecular events involved in bone repair and the current approaches to using stem cells as an adjunct to this process. The article emphasizes the key role of osteoprogenitor cells in the formation of bone and where the clinical applications of current research may lend themselves to large animal orthopaedics. The processes involved in osteogenic differentiation are presented and strategies for bone formation, including induction by osteogenic factors, bioscaffolds, and gene therapy, are reviewed. PMID:21872760

  1. A Review on Perforation Repair Materials

    PubMed Central

    Veeramachaneni, Chandrasekhar; Majeti, Chandrakanth; Tummala, Muralidhar; Khiyani, Laxmi

    2015-01-01

    Perforation is an artificial communication between the root canal system and supporting tissues of the teeth. Root perforation complicates the treatment and deprives the prognosis if not properly managed. A wide variety of materials to seal the perforations have been suggested in literature. There are many comparative studies showing the efficacy of one material over the other. Literature shows many reviews on diagnosis, treatment plan and factors affecting prognosis of perforation repair; but none of these articles elaborated upon various materials available to seal the perforation. The present article aims at describing all the materials used for perforation repair from the past till date; it also offers a literature review of all the articles published over last four decades referred to the treatment of perforation with various root repair materials. PMID:26501031

  2. Bone as a Structural Material.

    PubMed

    Zimmermann, Elizabeth A; Ritchie, Robert O

    2015-06-24

    As one of the most important natural materials, cortical bone is a composite material comprising assemblies of tropocollagen molecules and nanoscale hydroxyapatite mineral crystals, forming an extremely tough, yet lightweight, adaptive and multi-functional material. Bone has evolved to provide structural support to organisms, and therefore its mechanical properties are vital physiologically. Like many mineralized tissues, bone can resist deformation and fracture from the nature of its hierarchical structure, which spans molecular to macroscopic length-scales. In fact, bone derives its fracture resistance with a multitude of deformation and toughening mechanisms that are active at most of these dimensions. It is shown that bone's strength and ductility originate primarily at the scale of the nano to submicrometer structure of its mineralized collagen fibrils and fibers, whereas bone toughness is additionally generated at much larger, micro- to near-millimeter, scales from crack-tip shielding associated with interactions between the crack path and the microstructure. It is further shown how the effectiveness with which bone's structural features can resist fracture at small to large length-scales can become degraded by biological factors such as aging and disease, which affect such features as the collagen cross-linking environment, the homogeneity of mineralization, and the density of the osteonal structures.

  3. Electromagnetic fields in bone repair and adaptation

    NASA Astrophysics Data System (ADS)

    McLeod, Kenneth J.; Rubin, Clinton T.; Donahue, Henry J.

    1995-01-01

    The treatment of delayed union of bone fractures has served for the past 20 years as the principal testing ground for determining whether nonionizing electromagnetic fields can have any substantial, long-term effects in clinical medicine. Recent double-blinded clinical trials have confirmed the significance of the reported effects on bone healing and have led to the suggestion that electromagnetic fields may also be useful in the treatment of other orthopedic problems such as fresh fractures, stabilization of prosthetic implants, or even the prevention or treatment of osteoporosis. However, the design of appropriate treatment regimens for these new applications would be greatly facilitated if it were understood how the biological cells within bone tissue sense these low-frequency, and remarkably low level, electromagnetic fields. Here we address the engineering and physical science aspects of this problem. We review the characteristics of clinically used electromagnetic fields and discuss which components of these fields may actually be responsible for altering the activity of the bone cells. We then consider several physical mechanisms which have been proposed to explain how the cells within the bone or fracture tissue detect this field component.

  4. Chronic ethanol consumption results in deficient bone repair in rats.

    PubMed

    Chakkalakal, Dennis A; Novak, Jerzy R; Fritz, Edward D; Mollner, Teresa J; McVicker, Daniel L; Lybarger, Denise L; McGuire, Michael H; Donohue, Terrence M

    2002-01-01

    There is evidence that ethanol inhibits osteoblast function and that chronic ethanol consumption induces systemic bone loss and increases the risk of fracture in humans. The purpose of the present study was to determine whether chronic ethanol consumption also compromises the healing of injured bone. Male Sprague-Dawley rats, 8-10 weeks old, were placed into four feeding groups: group A received ethanol (36% of calories) as part of a liquid diet; group B was pair-fed to group A and received an isocaloric control diet containing maltodextrin; group C was fed the AIN-93M standard semi-purified liquid diet ad libitum; group D was fed the same ethanol diet as group A before bone injury, but after surgery (see below) these rats were given isocaloric control diet ad libitum. After 6 weeks on their respective diets, a bone repair model was surgically created at the midshaft in both fibulae of each rat. Seven weeks after injury the animals were euthanized and bone healing was evaluated by determining rigidity of the fibula by three-point bending, flexural modulus of the repair tissue and mineral content of the repair tissue. Rigidity of fibula in ethanol-fed rats and their pair-fed controls (groups A and B) were respectively 48 and 47% lower than in group C. Flexural modulus of the repair tissue in ethanol-fed rats had a 55% (P = 0.046) deficiency compared with their pair-fed controls. The mineral contents in groups A and B were respectively 16 and 13% lower than in group C. There were no significant differences in the results between groups C and D. Thus, the outcome of bone repair in ethanol-fed rats was deficient compared with rats receiving a standard maintenance diet. The repair tissue in ethanol-fed rats was mechanically inferior to that in pair-fed controls. This deficiency could not be attributed to the reduced food consumption of these animals. On the other hand, the restoration of normal bone healing in group D cannot be attributed solely to the cessation of

  5. Bone morphogenetic protein 2 stimulates endochondral ossification by regulating periosteal cell fate during bone repair

    PubMed Central

    Yu, Yan Yiu; Lieu, Shirley; Lu, Chuanyong; Colnot, Céline

    2010-01-01

    Bone repair depends on the coordinated action of numerous growth factors and cytokines to stimulate new skeletal tissue formation. Among all the growth factors involved in bone repair, Bone Morphogenetic Proteins (BMPs) are the only molecules now used therapeutically to enhance healing. Although BMPs are known as strong bone inducers, their role in initiating skeletal repair is not entirely elucidated. The aim of this study was to define the role of BMP2 during the early stages of bone regeneration and more specifically in regulating the fate of skeletal progenitors. During healing of non-stabilized fractures via endochondral ossification, exogenous BMP2 increased the deposition and resorption of cartilage and bone, which was correlated with a stimulation of osteoclastogenesis but not angiogenesis in the early phase of repair. During healing of stabilized fractures, which normally occurs via intramembranous ossification, exogenous BMP2 induced cartilage formation suggesting a role in regulating cell fate decisions. Specifically, the periosteum was found to be a target of exogenous BMP2 as shown by activation of the BMP pathway in this tissue. Using cell lineage analyses, we further show that BMP2 can direct cell differentiation towards the chondrogenic lineage within the periosteum but not the endosteum, indicating that skeletal progenitors within periosteum and endosteum respond differently to BMP signals. In conclusion, BMP2 plays an important role in the early stages of repair by recruiting local sources of skeletal progenitors within periosteum and endosteum and by determining their differentiation towards the chondrogenic and osteogenic lineages. PMID:20348041

  6. Hydrogel Delivery of Mesenchymal Stem Cell–Expressing Bone Morphogenetic Protein-2 Enhances Bone Defect Repair

    PubMed Central

    Hsiao, Hui-Yi; Yang, Shu-Rui; Brey, Eric M.; Chu, I-Ming

    2016-01-01

    Background: The application of bone tissue engineering for repairing bone defects has gradually shown some satisfactory progress. One of the concerns raising scientific attention is the poor supply of growth factors. A number of growth factor delivery approaches have been developed for promoting bone formation. However, there is no systematic comparison of those approaches on efficiency of neobone formation. In this study, the approaches using periosteum, direct supply of growth factors, or gene transfection of growth factors were evaluated to determine the osteogenic capacity on the repair of bone defect. Methods: In total, 42 male 21-week-old Sprague-Dawley rats weighing 250 to 400 g were used as the bone defect model to evaluate the bone repair efficiency. Various tissue engineered constructs of poly(ethylene glycol)-poly(l-lactic acid) (PEG-PLLA) copolymer hydrogel with periosteum, with external supply of bone morphogenetic protein-2 (BMP2), or with BMP2-transfected bone marrow–derived mesenchymal stem cells (BMMSCs) were filled in a 7-mm bone defect region. Animals were euthanized at 3 months, and the hydrogel constructs were harvested. The evaluation with histological staining and radiography analysis were performed for the volume of new bone formation. Results: The PEG-PLLA scaffold with BMMSCs promotes bone regeneration with the addition of periosteum. The group with BMP2-transfected BMMSCs demonstrated the largest volume of new bone among all the testing groups. Conclusions: Altogether, the results of this study provide the evidence that the combination of PEG-PLLA hydrogels with BMMSCs and sustained delivery of BMP2 resulted in the maximal bone regeneration.

  7. Hydrogel Delivery of Mesenchymal Stem Cell–Expressing Bone Morphogenetic Protein-2 Enhances Bone Defect Repair

    PubMed Central

    Hsiao, Hui-Yi; Yang, Shu-Rui; Brey, Eric M.; Chu, I-Ming

    2016-01-01

    Background: The application of bone tissue engineering for repairing bone defects has gradually shown some satisfactory progress. One of the concerns raising scientific attention is the poor supply of growth factors. A number of growth factor delivery approaches have been developed for promoting bone formation. However, there is no systematic comparison of those approaches on efficiency of neobone formation. In this study, the approaches using periosteum, direct supply of growth factors, or gene transfection of growth factors were evaluated to determine the osteogenic capacity on the repair of bone defect. Methods: In total, 42 male 21-week-old Sprague-Dawley rats weighing 250 to 400 g were used as the bone defect model to evaluate the bone repair efficiency. Various tissue engineered constructs of poly(ethylene glycol)-poly(l-lactic acid) (PEG-PLLA) copolymer hydrogel with periosteum, with external supply of bone morphogenetic protein-2 (BMP2), or with BMP2-transfected bone marrow–derived mesenchymal stem cells (BMMSCs) were filled in a 7-mm bone defect region. Animals were euthanized at 3 months, and the hydrogel constructs were harvested. The evaluation with histological staining and radiography analysis were performed for the volume of new bone formation. Results: The PEG-PLLA scaffold with BMMSCs promotes bone regeneration with the addition of periosteum. The group with BMP2-transfected BMMSCs demonstrated the largest volume of new bone among all the testing groups. Conclusions: Altogether, the results of this study provide the evidence that the combination of PEG-PLLA hydrogels with BMMSCs and sustained delivery of BMP2 resulted in the maximal bone regeneration. PMID:27622106

  8. Current Progress in Bioactive Ceramic Scaffolds for Bone Repair and Regeneration

    PubMed Central

    Gao, Chengde; Deng, Youwen; Feng, Pei; Mao, Zhongzheng; Li, Pengjian; Yang, Bo; Deng, Junjie; Cao, Yiyuan; Shuai, Cijun; Peng, Shuping

    2014-01-01

    Bioactive ceramics have received great attention in the past decades owing to their success in stimulating cell proliferation, differentiation and bone tissue regeneration. They can react and form chemical bonds with cells and tissues in human body. This paper provides a comprehensive review of the application of bioactive ceramics for bone repair and regeneration. The review systematically summarizes the types and characters of bioactive ceramics, the fabrication methods for nanostructure and hierarchically porous structure, typical toughness methods for ceramic scaffold and corresponding mechanisms such as fiber toughness, whisker toughness and particle toughness. Moreover, greater insights into the mechanisms of interaction between ceramics and cells are provided, as well as the development of ceramic-based composite materials. The development and challenges of bioactive ceramics are also discussed from the perspective of bone repair and regeneration. PMID:24646912

  9. Biosilicate® and low-level laser therapy improve bone repair in osteoporotic rats.

    PubMed

    Bossini, Paulo Sérgio; Rennó, Ana Claudia Muniz; Ribeiro, Daniel Araki; Fangel, Renan; Peitl, Oscar; Zanotto, Edgar Dutra; Parizotto, Nivaldo Antonio

    2011-03-01

    The aim of this study was to investigate the effects of a novel bioactive material (Biosilicate®) and low-level laser therapy (LLLT) on bone fracture consolidation in osteoporotic rats. Forty female Wistar rats were submitted to ovariectomy (OVX) to induce osteopenia. Eight weeks after surgery, the animals were randomly divided into four groups of 10 animals each: a bone defect control group (CG); a bone defect filled with Biosilicate group (BG); a bone defect filled with Biosilicate and irradiated with LLLT at 60 J/cm(2) group (BG60); and a bone defect filled with Biosilicate and irradiated with LLLT at 120 J/cm(2) group (BG120). Bone defects were surgically performed on both tibias. The size of particle used for Biosilicate was 180-212 µm. Histopathological analysis showed that bone defects were predominantly filled with the biomaterial in specimens treated with Biosilicate. LLLT with either 60 or 120 J/cm(2) was able to increase collagen, Cbfa-1, VGEF and COX-2 expression in the circumjacent cells of the biomaterial. A morphometric analysis revealed that the Biosilicate + laser groups showed a higher amount of newly formed bone. Our results indicate that laser therapy improves bone repair process in contact with Biosilicate as a result of increasing bone formation, as well as COX-2 and Cbfa-1 immunoexpression, angiogenesis and collagen deposition in osteoporotic rats. PMID:20925130

  10. Intramuscular injection of bone marrow mononuclear cells contributes to bone repair following midpalatal expansion in rats

    PubMed Central

    CHE, XIAOXIA; GUO, JIE; LI, XIANGDONG; WANG, LVE; WEI, SILONG

    2016-01-01

    Healing from injury requires the activation and proliferation of stem cells for tissue repair. Previous studies have demonstrated that bone marrow is a central pool of stem cells. The present study aimed to investigate the route undertaken by bone marrow mononuclear cells (BMMCs) following BMMC transplantation by masseter injection in a rat model of midpalatal expansion. The rats were divided into five groups according to the types of midpalatal expansion, incision and BMMC transplantation. Samples of midpalatal bone from the rats in each group were used for histological and immunohistochemical assessments to track and evaluate the differential potentials of the transplanted BMMCs in the masseter muscle and midpalatal bone. Bromodeoxyuridine was used as a BMMC tracing label, and M-cadherin was used to detect muscle satellite cells. The BMMCs injected into the masseter were observed, not only in the masseter, but also in the blood vessels and oral mucosa, and enveloped the midpalatal bone. A number of the BMMCs transformed into osteoblasts at the boundary of the neuromuscular bundle, and were embedded in the newly formed bone during midpalatal bone regeneration. The results of the present study suggested that BMMCs entered the circulation and migrated from muscle to the bone tissue, where they were involved in bone repair. Therefore, BMMCs may prove useful in the treatment of various types of cancer. PMID:26648442

  11. Repair of rat cranial bone defect by using bone morphogenetic protein-2-related peptide combined with microspheres composed of polylactic acid/polyglycolic acid copolymer and chitosan.

    PubMed

    Li, Jingfeng; Jin, Lin; Wang, Mingbo; Zhu, Shaobo; Xu, Shuyun

    2015-07-08

    The effects of the transplanted bone morphogenetic protein-2 (BMP2) -related peptide P24 and rhBMP2 combined with poly(lactic-co-glycolic acid) (PLGA)/chitosan (CS) microspheres were investigated in promoting the repair of rat cranial bone defect. Forty white rats were selected and equally divided into four groups (group A: 1 μg of rhBMP2/PLGA/CS composite; group B: 3 mg of P24/PLGA/CS composite; group C: 0.5 μg of rhBMP2 + 1.5 mg of P24/PLGA/CS composite; group D: blank PLGA/CS material), and rat cranial bone defect models with a diameter of 5 mm were established. The materials were transplanted to the cranial bone defects. The animals were sacrificed on weeks 6 and 12 post-operation. Radiographic examinations (x-ray imaging and 3D CT scanning) and histological evaluations were performed. The repaired areas of cranial bone defects were measured, and the osteogenetic abilities of various materials were compared. Cranial histology, imaging, and repaired area measurements showed that the osteogenetic effects at two time points (weeks 6 and 12) in group C were better than those in groups A and B. The effects in groups A and B were similar. Group D achieved the worst repair effect of cranial bone defects, where a large number of fibrous connective tissues were observed. The PLGA/CS composite microspheres loaded with rhBMP2 and P24 had optimal concrescence and could mutually increase their osteogenesis capability. rhBMP2 + P24/PLGA/CS composite is a novel material for bone defect repair with stable activity to induce bone formation.

  12. Repair of rat cranial bone defect by using bone morphogenetic protein-2-related peptide combined with microspheres composed of polylactic acid/polyglycolic acid copolymer and chitosan.

    PubMed

    Li, Jingfeng; Jin, Lin; Wang, Mingbo; Zhu, Shaobo; Xu, Shuyun

    2015-08-01

    The effects of the transplanted bone morphogenetic protein-2 (BMP2) -related peptide P24 and rhBMP2 combined with poly(lactic-co-glycolic acid) (PLGA)/chitosan (CS) microspheres were investigated in promoting the repair of rat cranial bone defect. Forty white rats were selected and equally divided into four groups (group A: 1 μg of rhBMP2/PLGA/CS composite; group B: 3 mg of P24/PLGA/CS composite; group C: 0.5 μg of rhBMP2 + 1.5 mg of P24/PLGA/CS composite; group D: blank PLGA/CS material), and rat cranial bone defect models with a diameter of 5 mm were established. The materials were transplanted to the cranial bone defects. The animals were sacrificed on weeks 6 and 12 post-operation. Radiographic examinations (x-ray imaging and 3D CT scanning) and histological evaluations were performed. The repaired areas of cranial bone defects were measured, and the osteogenetic abilities of various materials were compared. Cranial histology, imaging, and repaired area measurements showed that the osteogenetic effects at two time points (weeks 6 and 12) in group C were better than those in groups A and B. The effects in groups A and B were similar. Group D achieved the worst repair effect of cranial bone defects, where a large number of fibrous connective tissues were observed. The PLGA/CS composite microspheres loaded with rhBMP2 and P24 had optimal concrescence and could mutually increase their osteogenesis capability. rhBMP2 + P24/PLGA/CS composite is a novel material for bone defect repair with stable activity to induce bone formation. PMID:26154695

  13. Effect of a new bioactive fibrous glassy scaffold on bone repair.

    PubMed

    Gabbai-Armelin, P R; Souza, M T; Kido, H W; Tim, C R; Bossini, P S; Magri, A M P; Fernandes, K R; Pastor, F A C; Zanotto, E D; Parizotto, N A; Peitl, O; Renno, A C M

    2015-05-01

    Researchers have investigated several therapeutic approaches to treat non-union fractures. Among these, bioactive glasses and glass ceramics have been widely used as grafts. This class of biomaterial has the ability to integrate with living bone. Nevertheless, bioglass and bioactive materials have been used mainly as powder and blocks, compromising the filling of irregular bone defects. Considering this matter, our research group has developed a new bioactive glass composition that can originate malleable fibers, which can offer a more suitable material to be used as bone graft substitutes. Thus, the aim of this study was to assess the morphological structure (via scanning electron microscope) of these fibers upon incubation in phosphate buffered saline (PBS) after 1, 7 and 14 days and, also, evaluate the in vivo tissue response to the new biomaterial using implantation in rat tibial defects. The histopathological, immunohistochemistry and biomechanical analyzes after 15, 30 and 60 days of implantation were performed to investigate the effects of the material on bone repair. The PBS incubation indicated that the fibers of the glassy scaffold degraded over time. The histological analysis revealed a progressive degradation of the material with increasing implantation time and also its substitution by granulation tissue and woven bone. Histomorphometry showed a higher amount of newly formed bone area in the control group (CG) compared to the biomaterial group (BG) 15 days post-surgery. After 30 and 60 days, CG and BG showed a similar amount of newly formed bone. The novel biomaterial enhanced the expression of RUNX-2 and RANK-L, and also improved the mechanical properties of the tibial callus at day 15 after surgery. These results indicated a promising use of the new biomaterial for bone engineering. However, further long-term studies should be carried out to provide additional information concerning the material degradation in the later stages and the bone

  14. Effect of a new bioactive fibrous glassy scaffold on bone repair.

    PubMed

    Gabbai-Armelin, P R; Souza, M T; Kido, H W; Tim, C R; Bossini, P S; Magri, A M P; Fernandes, K R; Pastor, F A C; Zanotto, E D; Parizotto, N A; Peitl, O; Renno, A C M

    2015-05-01

    Researchers have investigated several therapeutic approaches to treat non-union fractures. Among these, bioactive glasses and glass ceramics have been widely used as grafts. This class of biomaterial has the ability to integrate with living bone. Nevertheless, bioglass and bioactive materials have been used mainly as powder and blocks, compromising the filling of irregular bone defects. Considering this matter, our research group has developed a new bioactive glass composition that can originate malleable fibers, which can offer a more suitable material to be used as bone graft substitutes. Thus, the aim of this study was to assess the morphological structure (via scanning electron microscope) of these fibers upon incubation in phosphate buffered saline (PBS) after 1, 7 and 14 days and, also, evaluate the in vivo tissue response to the new biomaterial using implantation in rat tibial defects. The histopathological, immunohistochemistry and biomechanical analyzes after 15, 30 and 60 days of implantation were performed to investigate the effects of the material on bone repair. The PBS incubation indicated that the fibers of the glassy scaffold degraded over time. The histological analysis revealed a progressive degradation of the material with increasing implantation time and also its substitution by granulation tissue and woven bone. Histomorphometry showed a higher amount of newly formed bone area in the control group (CG) compared to the biomaterial group (BG) 15 days post-surgery. After 30 and 60 days, CG and BG showed a similar amount of newly formed bone. The novel biomaterial enhanced the expression of RUNX-2 and RANK-L, and also improved the mechanical properties of the tibial callus at day 15 after surgery. These results indicated a promising use of the new biomaterial for bone engineering. However, further long-term studies should be carried out to provide additional information concerning the material degradation in the later stages and the bone

  15. Evaluating the effectiveness of gel formulation of irradiated seed lectin Cratylia mollis during bone repair in rats

    PubMed Central

    Santos-Oliveira, Ralph; Lima-Ribeiro, Maria Helena Madruga; Carneiro-Leão, Ana Maria dos Anjos; Cruz, Adriana Ferreira; de Santana, Mauricélia Firmino; Cavalcanti, Carmelita de Lima Bezerra; de Pontes Filho, Nicodemos Teles; Coelho, Luana Cassandra Breitenbach Barroso; dos Santos Correia, Maria Tereza

    2013-01-01

    Context: Regeneration corresponds to the replacement of damaged cells with ones that have the same morphology and function. For experimental evaluation of materials that may favor the process of bone healing, defects are created with dimensions that prevent spontaneous regeneration. For the development and use of new drugs, it is necessary to study its effects in vitro, which depends on the formulation, concentration, and rate of irradiation in vivo and the route and frequency of administration; thus, it is possible to characterize the physiological and molecular mechanisms involved in the response and cellular effects. Objective: The objective of this study was to assess the effect of Cramoll-1,4 on the process of bone repair. Materials and Methods: A formulation of biopharmaceutical lectin Cramoll-1,4 at a concentration of 300 mg/100 mL was applied in a single application via gamma radiation and its effect on the process of bone repair in rats was assessed. Results: Histologically, it was observed that the bone defect is coated by loose connective tissue rich in fibroblasts, providing a range similar to the thick bone original and competing with site of new bone formation. This prevented direct contact between the formulation and experimental bone tissue, as, despite its proven effectiveness in experiments on the repair of skin lesions, the formulation used did not promote bone stimulation that would have promoted the tissue repair process. Conclusion: Because of the direct interference of loose tissue repair that prevented direct contact of the implant with the bone interface, the formulation did not promote bone stimulation. PMID:24083142

  16. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is...

  17. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is...

  18. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is...

  19. Use of NASA Bioreactor in Engineering Tissue for Bone Repair

    NASA Technical Reports Server (NTRS)

    Duke, Pauline

    1998-01-01

    This study was proposed in search for a new alternative for bone replacement or repair. Because the systems commonly used in repair of bony defects form bone by going through a cartilaginous phase, implantation of a piece of cartilage could enhance the healing process by having a more advanced starting point. However, cartilage has seldom been used to replace bone due, in part, to the limitations in conventional culture systems that did not allow production of enough tissue for implants. The NASA-developed bioreactors known as STLV (Slow Turning Lateral Vessel) provide homogeneous distribution of cells, nutrients, and waste products, with less damaging turbulence and shear forces than conventional systems. Cultures under these conditions have higher growth rates, viability, and longevity, allowing larger "tissue-like" aggregates to form, thus opening the possibilities of producing enough tissue for implantation, along with the inherent advantages of in vitro manipulations. To assure large numbers of cells and to eliminate the use of timed embryos, we proposed to use an immortalized mouse limb bud cell line as the source of cells.

  20. Electrospun Fibers as a Scaffolding Platform for Bone Tissue Repair

    PubMed Central

    Lyu, Seungyoun; Huang, Chunlan; Yang, Hong; Zhang, Xinping

    2014-01-01

    The purpose of the study is to investigate the effects of electrospun fiber diameter and orientation on differentiation and ECM organization of bone marrow stromal cells (BMSCs), in attempt to provide rationale for fabrication of a periosteum mimetic for bone defect repair. Cellular growth, differentiation, and ECM organization were analyzed on PLGA-based random and aligned fibers using fluorescent microscopy, gene analyses, electron scanning microscopy (SEM), and multiphoton laser scanning microscopy (MPLSM). BMSCs on aligned fibers had a reduced number of ALP+ colony at day 10 as compared to the random fibers of the same size. However, the ALP+ area in the aligned fibers increased to a similar level as the random fibers at day 21 following stimulation with osteogenic media. Compared with the random fibers, BMSCs on the aligned fibers showed a higher expression of OSX and RUNX2. Analyses of ECM on decellularized spun fibers showed highly organized ECM arranged according to the orientation of the spun fibers, with a broad size distribution of collagen fibers in a range of 40nm to 2.4µm. Taken together, our data support the use of submicron-sized electrospun fibers for engineering of oriented fibrous tissue mimetic, such as periosteum, for guided bone repair and reconstruction. PMID:23580466

  1. Articular cartilage repair with autologous bone marrow mesenchymal cells.

    PubMed

    Matsumoto, Tomiya; Okabe, Takahiro; Ikawa, Tesshu; Iida, Takahiro; Yasuda, Hiroyuki; Nakamura, Hiroaki; Wakitani, Shigeyuki

    2010-11-01

    Articular cartilage defects that do not repair spontaneously induce osteoarthritic changes in joints over a long period of observation. In this study, we examined the usefulness of transplanting culture-expanded bone marrow mesenchymal cells into osteochondral defects of joints with cartilage defects. First, we performed experiments on rabbits and up on obtaining good results proceeded to perform the experiments on humans. Macroscopic and histological repair with this method was good, and good clinical results were obtained although there was no significant difference with the control group. Recent reports have indicated that this procedure is comparable to autologous chondrocyte implantation, and concluded that it was a good procedure because it required one step less than that required by surgery, reduced costs for patients, and minimized donor site morbidity. Although some reports have previously shown that progenitor cells formed a tumor when implanted into immune-deficient mice after long term in vitro culture, the safety of the cell transplantation was confirmed by our clinical experience. Thus, this procedure is useful, effective, and safe, but the repaired tissues were not always hyaline cartilage. To obtain better repair with this procedure, treatment approaches using some growth factors during in vitro culture or gene transfection are being explored.

  2. Anatomic and Biomechanical Comparison of Traditional Bankart Repair With Bone Tunnels and Bankart Repair Utilizing Suture Anchors

    PubMed Central

    Judson, Christopher H.; Charette, Ryan; Cavanaugh, Zachary; Shea, Kevin P.

    2016-01-01

    Background: Traditional Bankart repair using bone tunnels has a reported failure rate between 0% and 5% in long-term studies. Arthroscopic Bankart repair using suture anchors has become more popular; however, reported failure rates have been cited between 4% and 18%. There have been no satisfactory explanations for the differences in these outcomes. Hypothesis: Bone tunnels will provide increased coverage of the native labral footprint and demonstrate greater load to failure and stiffness and decreased cyclic displacement in biomechanical testing. Study Design: Controlled laboratory study. Methods: Twenty-two fresh-frozen cadaveric shoulders were used. For footprint analysis, the labral footprint area was marked and measured using a Microscribe technique in 6 specimens. A 3-suture anchor repair was performed, and the area of the uncovered footprint was measured. This was repeated with traditional bone tunnel repair. For the biomechanical analysis, 8 paired specimens were randomly assigned to bone tunnel or suture anchor repair with the contralateral specimen assigned to the other technique. Each specimen underwent cyclic loading (5-25 N, 1 Hz, 100 cycles) and load to failure (15 mm/min). Displacement was measured using a digitized video recording system. Results: Bankart repair with bone tunnels provided significantly more coverage of the native labral footprint than repair with suture anchors (100% vs 27%, P < .001). Repair with bone tunnels (21.9 ± 8.7 N/mm) showed significantly greater stiffness than suture anchor repair (17.1 ± 3.5 N/mm, P = .032). Mean load to failure and gap formation after cyclic loading were not statistically different between bone tunnel (259 ± 76.8 N, 0.209 ± 0.064 mm) and suture anchor repairs (221.5 ± 59.0 N [P = .071], 0.161 ± 0.51 mm [P = .100]). Conclusion: Bankart repair with bone tunnels completely covered the footprint anatomy while suture anchor repair covered less than 30% of the native footprint. Repair using bone tunnels

  3. Imaging characteristics of bone graft materials.

    PubMed

    Beaman, Francesca D; Bancroft, Laura W; Peterson, Jeffrey J; Kransdorf, Mark J; Menke, David M; DeOrio, James K

    2006-01-01

    Bone graft materials are widely used in reconstructive orthopedic procedures to promote new bone formation and bone healing, provide a substrate and scaffolding for development of bone structure, and function as a means for direct antibiotic delivery. Bone graft materials include autografts, allografts, and synthetic substitutes. An autograft (from the patient's own bone) supplies both bone volume and osteogenic cells capable of new bone formation. The imaging appearance of an autograft depends on its type, composition, and age. Autografts often appear as osseous fragments at radiography. At computed tomography (CT), autografts appear similar to the adjacent cortical bone. At magnetic resonance (MR) imaging, however, autografts have a variable appearance as a consequence of the viable marrow inside them, a feature not present in other graft materials. An allograft (from cadaveric bone) has an appearance similar to that of cortical bone on radiographs and CT images. An allograft in the form of bone chips or morsels does not show those features on radiographs and CT images, but instead appears as a conglomerate with medium to high opacity and attenuation within the bone defect. In the immediate postoperative period, allografts appear hypointense on both T1- and T2-weighted MR images. Hematopoietic tissue replaces the normal fatty marrow in the later phases of graft incorporation. Synthetic bone substitutes are much more variable in imaging appearance. As the use of bone allografts and synthetic substitutes increases, familiarity with postoperative imaging features is essential for differentiation between grafts and residual or recurrent disease.

  4. Process for Self-Repair of Insulation Material

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2007-01-01

    A self-healing system for an insulation material initiates a self-repair process by rupturing a plurality of microcapsules disposed on the insulation material. When the plurality of microcapsules are ruptured reactants witlun the plurality of microcapsules react to form a replacement polymer in a break of the insulation material. This self-healing system has the ability to repair multiple breaks in a length of insulation material without exhausting the repair properties of the material.

  5. Process for self-repair of insulation material

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2007-01-01

    A self-healing system for an insulation material initiates a self-repair process by rupturing a plurality of microcapsules disposed on the insulation material. When the plurality of microcapsules are ruptured reactants within the plurality of microcapsules react to form a replacement polymer in a break of the insulation material. This self-healing system has the ability to repair multiple breaks in a length of insulation material without exhausting the repair properties of the material.

  6. 3D artificial bones for bone repair prepared by computed tomography-guided fused deposition modeling for bone repair.

    PubMed

    Xu, Ning; Ye, Xiaojian; Wei, Daixu; Zhong, Jian; Chen, Yuyun; Xu, Guohua; He, Dannong

    2014-09-10

    The medical community has expressed significant interest in the development of new types of artificial bones that mimic natural bones. In this study, computed tomography (CT)-guided fused deposition modeling (FDM) was employed to fabricate polycaprolactone (PCL)/hydroxyapatite (HA) and PCL 3D artificial bones to mimic natural goat femurs. The in vitro mechanical properties, in vitro cell biocompatibility, and in vivo performance of the artificial bones in a long load-bearing goat femur bone segmental defect model were studied. All of the results indicate that CT-guided FDM is a simple, convenient, relatively low-cost method that is suitable for fabricating natural bonelike artificial bones. Moreover, PCL/HA 3D artificial bones prepared by CT-guided FDM have more close mechanics to natural bone, good in vitro cell biocompatibility, biodegradation ability, and appropriate in vivo new bone formation ability. Therefore, PCL/HA 3D artificial bones could be potentially be of use in the treatment of patients with clinical bone defects.

  7. High-strength silk protein scaffolds for bone repair

    PubMed Central

    Mandal, Biman B.; Grinberg, Ariela; Seok Gil, Eun; Panilaitis, Bruce; Kaplan, David L.

    2012-01-01

    Biomaterials for bone tissue regeneration represent a major focus of orthopedic research. However, only a handful of polymeric biomaterials are utilized today because of their failure to address critical issues like compressive strength for load-bearing bone grafts. In this study development of a high compressive strength (~13 MPa hydrated state) polymeric bone composite materials is reported, based on silk protein-protein interfacial bonding. Micron-sized silk fibers (10–600 µm) obtained utilizing alkali hydrolysis were used as reinforcement in a compact fiber composite with tunable compressive strength, surface roughness, and porosity based on the fiber length included. A combination of surface roughness, porosity, and scaffold stiffness favored human bone marrow-derived mesenchymal stem cell differentiation toward bone-like tissue in vitro based on biochemical and gene expression for bone markers. Further, minimal in vivo immunomodulatory responses suggested compatibility of the fabricated silk-fiber-reinforced composite matrices for bone engineering applications. PMID:22552231

  8. Bone Marrow Mesenchymal Stem Cell and Vein Conduit on Sciatic Nerve Repair in Rats

    PubMed Central

    Seyed Foroutan, Kamal; Khodarahmi, Ali; Alavi, Hootan; Pedram, Sepehr; Baghaban Eslaminejad, Mohamad Reza; Bordbar, Sima

    2015-01-01

    Background: Peripheral nerve repair with sufficient functional recovery is an important issue in reconstructive surgery. Stem cells have attracted extensive research interest in recent years. Objectives: The purpose of this study was to compare the vein conduit technique, with and without the addition of mesenchymal stem cells in gap-less nerve injury repair in rats. Materials and Methods: In this study, 36 Wistar rats were randomly allocated to three groups: In the first group, nerve repair was performed with simple neurorrhaphy (control group), in the second group, nerve repair was done with vein conduit over site (vein conduit group) and in the third group, bone marrow stem cells were instilled into the vein conduit (stem cell group) after nerve repair with vein conduit over site. Six weeks after the intervention, the sciatic function index, electrophysiological study and histological examination were performed. Results: All animals tolerated the surgical procedures and survived well. The sciatic function index and latency were significantly improved in the vein conduit (P = 0.04 and 0.03, respectively) and stem cell group (P = 0.02 and 0.03, respectively) compared with the control group. No significant difference was observed in sciatic function and latency between the vein conduit and stem-cell groups. Moreover, histological analysis showed no significant difference in regenerative density between these two groups. Conclusions: The results of this study showed that the meticulous microsurgical nerve repair, which was performed using the vein tubulization induced significantly better sciatic nerve regeneration. However, the addition of bone marrow mesenchymal stem cell to vein conduit failed to promote any significant changes in regeneration outcome. PMID:25825699

  9. Vascularization of repaired limb bone defects using chitosan-β-tricalcium phosphate composite as a tissue engineering bone scaffold.

    PubMed

    Yang, Le; Wang, Qinghua; Peng, Lihua; Yue, Hong; Zhang, Zhendong

    2015-08-01

    Ensuring histocompatibility in the tissue engineering of bones is a complex issue. The aim of this study was to observe the feasibility of chitosan-β-tricalcium phosphate composite in repairing limb bone defects, and to evaluate the therapeutic effects on osteogenesis. Beagle mesenchymal stem cells (MSCs) were divided into an experimental group that was cultured with an injectable form of chitosan-β-tricalcium phosphate composite and a control group. The effect of the composite on bone tissue growth was evaluated by MTT assay. In addition, 12-month-old beagles were subjected to 15-mm femur defects and subsequently implanted with scaffolds to observe the effects on osteogenesis and vascularization. The dogs were subdivided into two groups of five animals: Group A, which was implanted with scaffold-MSC compounds, and Group B, which was implanted with scaffolds alone. The dogs were observed on the 2nd, 4th, 8th and 12th weeks post-implantation. Scanning electron microscopy analysis revealed that the composite was compatible with MSCs, with similar outcomes in the control and experimental groups. MTT analysis additionally showed that the MSCs in the experimental group grew in a similar manner to those in the control group. The composite did not significantly affect the MSC growth or proliferation. In combination with MSCs, the scaffold materials were effective in the promotion of osteogenesis and vascularization. In conclusion, the chitosan-β-tricalcium phosphate composite was compatible with the MSCs and did not affect cellular growth or proliferation, therefore proving to be an effective injectable composite for tissue engineered bone. Simultaneous implantation of stem cells with a carrier composite proved to function effectively in the repair of bone defects.

  10. Strategies to Stimulate Mobilization and Homing of Endogenous Stem and Progenitor Cells for Bone Tissue Repair

    PubMed Central

    Herrmann, Marietta; Verrier, Sophie; Alini, Mauro

    2015-01-01

    The gold standard for the treatment of critical-size bone defects is autologous or allogenic bone graft. This has several limitations including donor site morbidity and the restricted supply of graft material. Cell-based tissue engineering strategies represent an alternative approach. Mesenchymal stem cells (MSCs) have been considered as a source of osteoprogenitor cells. More recently, focus has been placed on the use of endothelial progenitor cells (EPCs), since vascularization is a critical step in bone healing. Although many of these approaches have demonstrated effectiveness for bone regeneration, cell-based therapies require time consuming and cost-expensive in vitro cell expansion procedures. Accordingly, research is becoming increasingly focused on the homing and stimulation of native cells. The stromal cell-derived factor-1 (SDF-1) – CXCR4 axis has been shown to be critical for the recruitment of MSCs and EPCs. Vascular endothelial growth factor (VEGF) is a key factor in angiogenesis and has been targeted in many studies. Here, we present an overview of the different approaches for delivering homing factors to the defect site by absorption or incorporation to biomaterials, gene therapy, or via genetically manipulated cells. We further review strategies focusing on the stimulation of endogenous cells to support bone repair. Finally, we discuss the major challenges in the treatment of critical-size bone defects and fracture non-unions. PMID:26082926

  11. Bone-repair properties of biodegradable hydroxyapatite nano-rod superstructures.

    PubMed

    D'Elía, Noelia L; Mathieu, Colleen; Hoemann, Caroline D; Laiuppa, Juan A; Santillán, Graciela E; Messina, Paula V

    2015-11-28

    Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions of bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblasts and rabbit mesenchymal stem cells. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiated, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (α-SMA) protein. These results highlight the influence of material's surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants. PMID:26505580

  12. Bone-repair properties of biodegradable hydroxyapatite nano-rod superstructures.

    PubMed

    D'Elía, Noelia L; Mathieu, Colleen; Hoemann, Caroline D; Laiuppa, Juan A; Santillán, Graciela E; Messina, Paula V

    2015-11-28

    Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions of bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblasts and rabbit mesenchymal stem cells. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiated, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (α-SMA) protein. These results highlight the influence of material's surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants.

  13. Self-repair of cracks in brittle material systems

    NASA Astrophysics Data System (ADS)

    Dry, Carolyn M.

    2016-04-01

    One of the most effective uses for self repair is in material systems that crack because the cracks can allow the repair chemical to flow into the crack damage sites in all three dimensions. In order for the repair chemical to stay in the damage site and flow along to all the crack and repair there must be enough chemical to fill the entire crack. The repair chemical must be designed appropriately for the particular crack size and total volume of cracks. In each of the three examples of self repair in crackable brittle systems, the viscosity and chemical makeup and volume of the repair chemicals used is different for each system. Further the chemical delivery system has to be designed for each application also. Test results from self repair of three brittle systems are discussed. In "Self Repair of Concrete Bridges and Infrastructure" two chemicals were used due to different placements in bridges to repair different types of cracks- surface shrinkage and shear cracks, In "Airplane Wings and Fuselage, in Graphite" the composite has very different properties than the concrete bridges. In the graphite for airplane components the chemical also had to survive the high processing temperatures. In this composite the cracks were so definite and deep and thin that the repair chemical could flow easily and repair in all layers of the composite. In "Ceramic/Composite Demonstrating Self Repair" the self repair system not only repaired the broken ceramic but also rebounded the composite to the ceramic layer

  14. Skeletal repair by in situ formation of the mineral phase of bone

    SciTech Connect

    Constantz, B.R.; Ison, I.C.; Fulmer, M.T.; Poser, R.D.; Smith, S.T.; VanWagoner, M.; Ross, J.; Goldstein, S.A.; Jupiter, J.B.; Rosenthal, D.I.

    1995-03-24

    A process has been developed for the in situ formation of the mineral phase of bone. Inorganic calcium and phosphate sources are combined to form a paste that is surgically implanted by injection. Under physiological conditions, the material hardens in minutes concurrent with the formation of dahllite. After 12 hours, dahllite formation was nearly complete, and an ultimate compressive strength of 55 megapascals was achieved. The composition and crystal morphology of the dahllite formed are similar to those of bone. Animal studies provide evidence that the material is remodeled in vivo. A novel approach to skeletal repair is being tested in human trials for various applications; in one of the trials the new biomaterial is being percutaneously placed into acute fractures. After hardening, it serves as internal fixation to maintain proper alignment while healing occurs. 33 refs., 6 figs., 1 tab.

  15. Stromal cell-derived factor-1 mediates changes of bone marrow stem cells during the bone repair process.

    PubMed

    Okada, Kiyotaka; Kawao, Naoyuki; Yano, Masato; Tamura, Yukinori; Kurashimo, Shinzi; Okumoto, Katsumi; Kojima, Kotarou; Kaji, Hiroshi

    2016-01-01

    Osteoblasts, osteoclasts, chondrocytes, and macrophages that participate in the bone repair process are derived from hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). However, the roles of these stem cells during the repair of injured bone tissue are still unclear. In the present study, we examined the effects of bone defect on HSCs and MSCs in bone marrow and spleen in 75 mice and its mechanism. We analyzed the HSC and MSC populations in these tissues of a mouse with femoral bone damage by using flow cytometry. The number of HSCs in the bone marrow of mice with damaged femurs was significantly lower than the number of these cells in the bone marrow of the contralateral intact femurs on day 2 after injury. Meanwhile, the number of MSCs in the bone marrow of mice with damaged femurs was significantly higher than that of the contralateral femurs. Both intraperitoneal administration of AMD3100, a C-X-C chemokine receptor 4 (CXCR4) antagonist, and local treatment with an anti-stromal cell-derived factor-1 (SDF-1) antibody blunted the observed decrease in HSC and increase in MSC populations within the bone marrow of injured femurs. In conclusion, the present study revealed that there is a concurrent decrease and increase in the numbers of HSCs and MSCs, respectively, in the bone marrow during repair of mouse femoral bone damage. Furthermore, the SDF-1/CXCR4 system was implicated as contributing to the changes in these stem cell populations upon bone injury.

  16. Cartilage Repair With Autologous Bone Marrow Mesenchymal Stem Cell Transplantation

    PubMed Central

    Yamasaki, Shinya; Mera, Hisashi; Itokazu, Maki; Hashimoto, Yusuke

    2014-01-01

    Clinical trials of various procedures, including bone marrow stimulation, mosaicplasty, and autologous chondrocyte implantation, have been explored to treat articular cartilage defects. However, all of them have some demerits. We focused on autologous culture-expanded bone marrow mesenchymal stem cells (BMSC), which can proliferate without losing their capacity for differentiation. First, we transplanted BMSC into the defective articular cartilage of rabbit and succeeded in regenerating osteochondral tissue. We then applied this transplantation in humans. Our previous reports showed that treatment with BMSC relieves the clinical symptoms of chondral defects in the knee and elbow joint. We investigated the efficacy of BMSC for osteoarthritic knee treated with high tibial osteotomy, by comparing 12 BMSC-transplanted patients with 12 cell-free patients. At 16-month follow-up, although the difference in clinical improvement between both groups was not significant, the arthroscopic and histological grading score was better in the cell-transplanted group. At the over 10-year follow-up, Hospital for Special Surgery knee scores improved to 76 and 73 in the BMSC-transplanted and cell-free groups, respectively, which were better than preoperative scores. Additionally, neither tumors nor infections were observed in all patients, and in the clinical study, we have never observed hypertrophy of repaired tissue, thereby guaranteeing the clinical safety of this therapy. Although we have never observed calcification above the tidemark in rabbit model and human histologically, the repair cartilage was not completely hyaline cartilage. To elucidate the optimum conditions for cell therapy, other stem cells, culture conditions, growth factors, and gene transfection methods should be explored. PMID:26069698

  17. Bone critical defect repair with poloxamine-cyclodextrin supramolecular gels.

    PubMed

    del Rosario, C; Rodríguez-Évora, M; Reyes, R; Simões, S; Concheiro, A; Évora, C; Alvarez-Lorenzo, C; Delgado, A

    2015-11-10

    The aim of this study was to evaluate the osteoinductive capacity of a poloxamine (Tetronic(®) 908, T) and α-cyclodextrin (αCD) supramolecular gel (T-CD) as scaffold in a critical size defect in rat calvaria. The T-CD gel was evaluated solely and after being loaded with simvastatin (SV) and bone morphogenetic protein (BMP-2) separately and in combinations in order to reduce the doses of the active substances. Three doses of SV (7.5, 75, 750 μg) and two doses of BMP-2 (3 and 6 μg) were tested. The histology and histomorphometrical analysis showed improved bone repair with T-CD compared to T, probably due to better release control of both SV and BMP-2. In addition, as T-CD eroded more slowly than poloxamine alone, it remained longer in the defect site. Although synergism was not obtained with BMP-2 and SV, according to the observed regeneration of the defect, the dose of BMP-2 and SV can be reduced to 3 μg and 7.5 μg, respectively. PMID:26362078

  18. Laser therapy in bone repair in rats: analysis of bone optical density

    PubMed Central

    Barbosa, Danillo; Villaverde, Antonio Guillermo Jose Balbin; LoschiavoArisawa, Emilia Ângela; de Souza, Renato Aparecido

    2014-01-01

    OBJECTIVE: To investigate, by digital radiology, the bone regeneration process in rats submitted to femoral osteotomy and treated with low power laser therapy. METHODS: Forty-five Wistar rats were subjected to transverse osteotomy of the right femur and divided randomly into three experimental groups (n = 15): animals not treated with laser therapy G (C), animals that received laser therapy with λ: 660nm G (660nm) and animals that received laser therapy with λ: 830nm G (830nm). Animals were sacrificed after 7, 14 and 21 days. The bone calluses were evaluated by digital X-ray at 65 kVp, 7mA and 0.032 s exposures. RESULTS: The values obtained were submitted to variance analysis (ANOVA) followed by the Tukey-Kramer test. The significance level adopted was 5%. The groups G (C), G (660nm), and G (830nm) at the 7th day showed a significant bone development, with p <0.0116; the groups G (C), G (660nm), and G (830nm) at the 14th day showed values of p <0.0001; at the 21st day,a higher degree of bone repair were observed in group G (830nm), and G (660nm), with p <0.0169. CONCLUSION: Based on the radiographic findings, G (830nm) showed more complete bone regeneration, as shown in the gray shades of the images. Level of Evidence II, Individual Study With Experimental Design. PMID:24868182

  19. Impact of micronutrients supplementation on bone repair around implants: microCT and counter-torque analysis in rats

    PubMed Central

    Pimentel, Suzana Peres; Casarin, Renato Correa; Ribeiro, Fernanda Vieira; Cirano, Fabiano Ribeiro; Rovaris, Karla; Haiter, Francisco; Casati, Marcio Zaffalon

    2016-01-01

    ABSTRACT The use of natural substances and micronutritional approaches has been suggested as a therapeutic alternative to benefit the bone healing associated with no side effects. Nevertheless, the influence of micronutritional interventions with therapeutic proprieties on the bone repair has yet to be intensely evaluated, and no evidence is available exploring the impact of micronutrient supplementation on the peri-implant bone healing. Objective This study investigated the effect of micronutrients supplementation on the bone repair around implants. Material and Methods One screw-shaped titanium implant was inserted in each tibia of each rat, which were assigned to: daily administration, for 30 d, of the placebo solution (Placebo group-n:18) or micronutrients supplementation (Micronutrients group-n:18), based on calcium, magnesium, zinc, and vitamin D3 intake. After, the animals were sacrificed. One of the implants was removed by applying a counter-torque force to evaluate the force to rupture the bone-implant interface. The other implant was evaluated by microcomputed tomography (CT) examination to determine the bone-to-implant contact (BIC) and the bone volume (BV/TV). Results No statistically significant differences were observed between the groups for both counter-torque values and microCT parameters (p>0.05). Conclusion Within the limits of this study, micronutrients supplementation did not provide additional benefits to the bone healing around dental implants. PMID:27008256

  20. Premixed rapid-setting calcium phosphate composites for bone repair.

    PubMed

    Carey, Lisa E; Xu, Hockin H K; Simon, Carl G; Takagi, Shozo; Chow, Laurence C

    2005-08-01

    Although calcium phosphate cement (CPC) is promising for bone repair, its clinical use requires on site powder-liquid mixing. To shorten surgical time and improve graft properties, it is desirable to develop premixed CPC in which the paste remains stable during storage and hardens only after placement into the defect. The objective of this study was to develop premixed CPC with rapid setting when immersed in a physiological solution. Premixed CPCs were formulated using the following approach: Premixed CPC = CPC powder + nonaqueous liquid + gelling agent + hardening accelerator. Three premixed CPCs were developed: CPC-monocalcium phosphate monohydrate (MCPM), CPC-chitosan, and CPC-tartaric. Setting time for these new premixed CPCs ranged from 5.3 to 7.9 min, significantly faster than 61.7 min for a premixed control CPC reported previously (p < 0.05). SEM revealed the formation of nano-sized needle-like hydroxyapatite crystals after 1 d immersion and crystal growth after 7 d. Diametral tensile strength for premixed CPCs at 7 d ranged from 2.8 to 6.4 MPa, comparable to reported strengths for cancellous bone and sintered porous hydroxyapatite implants. Osteoblast cells attained a normal polygonal morphology on CPC-MCPM and CPC-chitosan with cytoplasmic extensions adhering to the nano-hydroxyapatite crystals. In summary, fast-setting premixed CPCs were developed to avoid the powder-liquid mixing in surgery. The pastes hardened rapidly once immersed in physiological solution and formed hydroxyapatite. The cements had strengths matching those of cancellous bone and sintered porous hydroxyapatite and non-cytotoxicity similar to conventional non-premixed CPC.

  1. CXCR2 modulates bone marrow vascular repair and haematopoietic recovery post-transplant.

    PubMed

    Hale, Sarah J M; Hale, Ashley B H; Zhang, Youyi; Sweeney, Dominic; Fisher, Nita; van der Garde, Mark; Grabowska, Rita; Pepperell, Emma; Channon, Keith; Martin-Rendon, Enca; Watt, Suzanne M

    2015-05-01

    Murine models of bone marrow transplantation show that pre-conditioning regimens affect the integrity of the bone marrow endothelium and that the repair of this vascular niche is an essential pre-requisite for successful haematopoietic stem and progenitor cell engraftment. Little is known about the angiogenic pathways that play a role in the repair of the human bone marrow vascular niche. We therefore established an in vitro humanized model, composed of bone marrow stromal and endothelial cells and have identified several pro-angiogenic factors, VEGFA, ANGPT1, CXCL8 and CXCL16, produced by the stromal component of this niche. We demonstrate for the first time that addition of CXCL8 or inhibition of its receptor, CXCR2, modulates blood vessel formation in our bone marrow endothelial niche model. Compared to wild type, Cxcr2(-/-) mice displayed a reduction in bone marrow cellularity and delayed platelet and leucocyte recovery following myeloablation and bone marrow transplantation. The delay in bone marrow recovery correlated with impaired bone marrow vascular repair. Taken together, our data demonstrate that CXCR2 regulates bone marrow blood vessel repair/regeneration and haematopoietic recovery, and clinically may be a therapeutic target for improving bone marrow transplantation.

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

    PubMed

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

    2012-12-01

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

  3. Pullulan/dextran/nHA macroporous composite beads for bone repair in a femoral condyle defect in rats.

    PubMed

    Schlaubitz, Silke; Derkaoui, Sidi Mohammed; Marosa, Lydia; Miraux, Sylvain; Renard, Martine; Catros, Sylvain; Le Visage, Catherine; Letourneur, Didier; Amédée, Joëlle; Fricain, Jean-Christophe

    2014-01-01

    The repair of bone defects is of particular interest for orthopedic, oral, maxillofacial, and dental surgery. Bone loss requiring reconstruction is conventionally addressed through bone grafting. Depending on the size and the location of the defect, this method has limits and risks. Biomaterials can offer an alternative and have features supporting bone repair. Here, we propose to evaluate the cellular penetration and bone formation of new macroporous beads based on pullulan/dextran that has been supplemented with nanocrystalline hydroxyapatite in a rat model. Cross-linked beads of 300-500 µm diameters were used in a lateral femoral condyle defect and analyzed by magnetic resonance imaging, micro-computed tomography, and histology in comparison to the empty defects 15, 30, and 70 days after implantation. Inflammation was absent for both conditions. For empty defects, cellularisation and mineralization started from the periphery of the defect. For the defects containing beads, cellular structures filling out the spaces between the scaffolds with increasing interconnectivity and trabecular-like organization were observed over time. The analysis of calcified sections showed increased mineralization over time for both conditions, but was more pronounced for the samples containing beads. Bone Mineral Density and Bone Mineral Content were both significantly higher at day 70 for the beads in comparison to empty defects as well as compared with earlier time points. Analysis of newly formed tissue around the beads showed an increase of osteoid tissue, measured as percentage of the defect surface. This study suggests that the use of beads for the repair of small size defects in bone may be expanded on to meet the clinical need for a ready-to-use fill-up material that can favor bone formation and mineralization, as well as promote vessel ingrowth into the defect site.

  4. Pullulan/dextran/nHA Macroporous Composite Beads for Bone Repair in a Femoral Condyle Defect in Rats

    PubMed Central

    Schlaubitz, Silke; Derkaoui, Sidi Mohammed; Marosa, Lydia; Miraux, Sylvain; Renard, Martine; Catros, Sylvain; Le Visage, Catherine; Letourneur, Didier; Amédée, Joëlle; Fricain, Jean-Christophe

    2014-01-01

    The repair of bone defects is of particular interest for orthopedic, oral, maxillofacial, and dental surgery. Bone loss requiring reconstruction is conventionally addressed through bone grafting. Depending on the size and the location of the defect, this method has limits and risks. Biomaterials can offer an alternative and have features supporting bone repair. Here, we propose to evaluate the cellular penetration and bone formation of new macroporous beads based on pullulan/dextran that has been supplemented with nanocrystalline hydroxyapatite in a rat model. Cross-linked beads of 300–500 µm diameters were used in a lateral femoral condyle defect and analyzed by magnetic resonance imaging, micro-computed tomography, and histology in comparison to the empty defects 15, 30, and 70 days after implantation. Inflammation was absent for both conditions. For empty defects, cellularisation and mineralization started from the periphery of the defect. For the defects containing beads, cellular structures filling out the spaces between the scaffolds with increasing interconnectivity and trabecular-like organization were observed over time. The analysis of calcified sections showed increased mineralization over time for both conditions, but was more pronounced for the samples containing beads. Bone Mineral Density and Bone Mineral Content were both significantly higher at day 70 for the beads in comparison to empty defects as well as compared with earlier time points. Analysis of newly formed tissue around the beads showed an increase of osteoid tissue, measured as percentage of the defect surface. This study suggests that the use of beads for the repair of small size defects in bone may be expanded on to meet the clinical need for a ready-to-use fill-up material that can favor bone formation and mineralization, as well as promote vessel ingrowth into the defect site. PMID:25330002

  5. Resveratrol improves bone repair by modulation of bone morphogenetic proteins and osteopontin gene expression in rats.

    PubMed

    Casarin, R C; Casati, M Z; Pimentel, S P; Cirano, F R; Algayer, M; Pires, P R; Ghiraldini, B; Duarte, P M; Ribeiro, F V

    2014-07-01

    This study investigated the effect of resveratrol on bone healing and its influence on the gene expression of osteogenic markers. Two calvarial defects were created and one screw-shaped titanium implant was inserted in the tibia of rats that were assigned to daily administration of placebo (control group, n=15) or 10mg/kg of resveratrol (RESV group, n=15) for 30 days. The animals were then sacrificed. One of the calvarial defects was processed for histomorphometric analysis and the tissue relative to the other was collected for mRNA quantification of bone morphogenetic protein (BMP)-2, BMP-7, osteopontin (OPN), bone sialoprotein (BSP), osteoprotegrin (OPG), and receptor activator of NF-κB ligand (RANKL). Implants were removed by applying a counter-torque force. Histomorphometric analysis revealed higher remaining defect in the calvarial defects of the control group than the RESV group (P=0.026). Resveratrol increased the counter-torque values of implant removal when compared to control therapy (P=0.031). Gene expression analysis showed a higher expression of BMP-2 (P=0.011), BMP-7 (P=0.049), and OPN (P=0.002) genes in the RESV group than in the control group. In conclusion, resveratrol improved the repair of critical-sized bone defects and the biomechanical retention of implants. Indeed, this natural agent may up-regulate the gene expression of important osteogenic markers. PMID:24530035

  6. The application of porous tantalum cylinder to the repair of comminuted bone defects: a study of rabbit firearm injuries

    PubMed Central

    Ren, Bo; Zhai, Zhenbo; Guo, Kai; Liu, Yanpu; Hou, Weihuan; Zhu, Qingsheng; Zhu, Jinyu

    2015-01-01

    The aim of this study is to investigate the effect of porous tantalum material in repair tibial defects caused by firearm injuries in a rabbit model. A multifunctional biological impact machine was used to establish a rabbit tibial defect model of firearm injury. Porous tantalum rods were processed into a hollow cylinder. Kirschner wires were used for intramedullary fixation. We compared the differences of the bone ingrowth of the porous tantalum material by gross observations, X-rays and histological evaluations. The radiographic observations revealed that fibrous tissue covered the material surface after 4 weeks, and periosteal reactions and new bone callus extending materials appeared after 8 weeks. After 16 weeks, the calluses of the firearm injury group were completely wrapped around a porous tantalum material. The group with the highest Lane-Sandhu X-rays cores was the firearm injury and tantalum implant group, and the blank control group exhibited the lowest scores. The histological evaluations revealed that the presence of new bone around the biomaterial had grown into the porous tantalum. By the 16th week, the areas of bone tissue of the firearm injury group was significant higher than that of non-firearm injury group (P<0.05). The comminuted fractures treated with tantalum cylinders exhibited greater bone ingrowth in the firearm injury group. In conditions of firearm injuries, the porous tantalum biomaterial exhibited bone ingrowth that was beneficial to the treatment of bone defects. PMID:26131078

  7. The application of porous tantalum cylinder to the repair of comminuted bone defects: a study of rabbit firearm injuries.

    PubMed

    Ren, Bo; Zhai, Zhenbo; Guo, Kai; Liu, Yanpu; Hou, Weihuan; Zhu, Qingsheng; Zhu, Jinyu

    2015-01-01

    The aim of this study is to investigate the effect of porous tantalum material in repair tibial defects caused by firearm injuries in a rabbit model. A multifunctional biological impact machine was used to establish a rabbit tibial defect model of firearm injury. Porous tantalum rods were processed into a hollow cylinder. Kirschner wires were used for intramedullary fixation. We compared the differences of the bone ingrowth of the porous tantalum material by gross observations, X-rays and histological evaluations. The radiographic observations revealed that fibrous tissue covered the material surface after 4 weeks, and periosteal reactions and new bone callus extending materials appeared after 8 weeks. After 16 weeks, the calluses of the firearm injury group were completely wrapped around a porous tantalum material. The group with the highest Lane-Sandhu X-rays cores was the firearm injury and tantalum implant group, and the blank control group exhibited the lowest scores. The histological evaluations revealed that the presence of new bone around the biomaterial had grown into the porous tantalum. By the 16th week, the areas of bone tissue of the firearm injury group was significant higher than that of non-firearm injury group (P<0.05). The comminuted fractures treated with tantalum cylinders exhibited greater bone ingrowth in the firearm injury group. In conditions of firearm injuries, the porous tantalum biomaterial exhibited bone ingrowth that was beneficial to the treatment of bone defects.

  8. Development of nanohydroxyapatite/polycarbonate composite for bone repair.

    PubMed

    Liao Jianguo; Zhang Li; Zuo Yi; Wang Huanan; Li Jidong; Zou Qin; Li Yubao

    2009-07-01

    In this study, nano-hydroxyapatite (n-HA) combined polycarbonate was synthesized by a novel method. The physical and chemical property of the composite was tested. The results indicated the n-HA a crystal has the similar grain size, phase composition and crystal structure as. TEM photos results show the n-HA crystals were uniformly distributed in the polymer matrix. Then, the chemical bond between inorganic n-HA and polycarbonate was investigated and discussed. Proliferation of MSCs/composite cultured for up to 11 days the adhesion were tested by MTT and SEM. The in vitro test confirmed that the n-HA/PC composite was biocompatible and no negative effect on MSCs has found. The composite is proved to be osteoconductive, and can stimulate the growth of new bone. These results indicated that the composite meet the basic requirement of bone substitute material, and be potentially applied for clinic.

  9. Enhanced Bone Repair by Guided Osteoblast Recruitment Using Topographically Defined Implant.

    PubMed

    Yoon, Jeong-Kee; Kim, Hong Nam; Bhang, Suk Ho; Shin, Jung-Youn; Han, Jin; La, Wan-Geun; Jeong, Gun-Jae; Kang, Seokyung; Lee, Ju-Ro; Oh, Jaesur; Kim, Min Sung; Jeon, Noo Li; Kim, Byung-Soo

    2016-04-01

    The rapid recruitment of osteoblasts in bone defects is an essential prerequisite for efficient bone repair. Conventionally, osteoblast recruitment to bone defects and subsequent bone repair has been achieved using growth factors. Here, we present a methodology that can guide the recruitment of osteoblasts to bone defects with topographically defined implants (TIs) for efficient in vivo bone repair. We compared circular TIs that had microgrooves in parallel or radial arrangements with nonpatterned implants for osteoblast migration and in vivo bone formation. In vitro, the microgrooves in the TIs enhanced both the migration and proliferation of osteoblasts. Especially, the microgrooves with radial arrangement demonstrated a much higher efficiency of osteoblast recruitment to the implants than did the other types of implants, which may be due to the efficient guidance of cell migration toward the cell-free area of the implants. The expression of the intracellular signaling molecules responsible for the cell migration was also upregulated in osteoblasts on the microgrooved TIs. In vivo, the TI with radially defined topography demonstrated much greater bone repair in mouse calvarial defect models than in the other types of implants. Taken together, these results indicate that implants with physical guidance can enhance tissue repair by rapid cell recruitment.

  10. Combination of platelet-rich plasma with degradable bioactive borate glass for segmental bone defect repair.

    PubMed

    Zhang, Ya-Dong; Wang, Gang; Sun, Yan; Zhang, Chang-Qing

    2011-02-01

    Porous scaffold biomaterials may offer a clinical alternative to bone grafts; however, scaffolds alone are typically insufficient to heal large bone defects. Numerous studies have demonstrated that osteoinductive growth factor significantly improves bone repair. In this study, a strategy combining degradable bioactive borate glass (BG) scaffolds with platelet-rich plasma (PRP) was tested. The bone defect was filled with BG alone, BG combined with autologous PRP or left empty. Bone formation was analyzed at 4, 8 and 12 weeks using both histology and radiology. The PRP treated group yielded better bone formation than the pure BG scaffold as determined by both histology and microcomputer tomography after 12 weeks. In conclusion, PRP improved bone healing in a diaphyseal rabbit model on BG. The combination of PRP and BG may be an effective approach to repair critical defects.

  11. Shear Bond Strength of Repaired Composites Using Surface Treatments and Repair Materials: An In vitro Study

    PubMed Central

    Hemadri, M; Saritha, G; Rajasekhar, V; Pachlag, K Amit; Purushotham, R; Reddy, Veera Kishore Kumar

    2014-01-01

    Background: Enhancement of bond strength between new and old composite usually requires increased surface roughness of old composite to promote mechanical interlocking and subsequent coating with bonding agents to improve surface wetting and chemical bonding. So this study was carried out to evaluate and compare the effects of different surface treatments and repair materials on the shear bond strength (SBS) of composite repairs The mode of failure of repaired composites whether cohesive or adhesive was also evaluated. Materials and Methods: The substrates for 60 composite specimens were fabricated and aged with water treatment and subjected to various surface treatments. The surface treatment regimens used in the study were: No surface treatment, abraded with diamond bur, air abraded (sandblasted) with 50 µ aluminum oxide particles. Specimens were then repaired with fresh composite using either Clearfil™ repair or all-bond two adhesive systems. Specimens were water stored, thermocycled and tested for SBS using universal testing machine. Fractured specimens were then examined under stereomicroscope to determine the mode of failure. Results: It was clearly showed that surface roughening of the aged composite substrate with air abrasion, followed by the application of Clearfil™ repair adhesive system (Group IIIa) yielded the highest repair bond strength (32.3 ± 2.2 MPa). Conclusion: Surface treatment with air abrasion followed by bonding with Clearfil™ repair adhesive system can be attempted clinically for the repair of composite restorations. PMID:25628478

  12. Bone-repair properties of biodegradable hydroxyapatite nano-rod superstructures

    NASA Astrophysics Data System (ADS)

    D'Elía, Noelia L.; Mathieu, Colleen; Hoemann, Caroline D.; Laiuppa, Juan A.; Santillán, Graciela E.; Messina, Paula V.

    2015-11-01

    Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions of bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblasts and rabbit mesenchymal stem cells. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiated, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (α-SMA) protein. These results highlight the influence of material's surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants.Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures

  13. Spatiotemporal Analyses of Osteogenesis and Angiogenesis via Intravital Imaging in Cranial Bone Defect Repair

    PubMed Central

    Huang, Chunlan; Ness, Vincent P.; Yang, Xiaochuan; Chen, Hongli; Luo, Jiebo; Brown, Edward B; Zhang, Xinping

    2015-01-01

    Osteogenesis and angiogenesis are two integrated components in bone repair and regeneration. A deeper understanding of osteogenesis and angiogenesis has been hampered by technical difficulties of analyzing bone and neovasculature simultaneously in spatiotemporal scales and in three-dimensional formats. To overcome these barriers, a cranial defect window chamber model was established that enabled high-resolution, longitudinal, and real-time tracking of angiogenesis and bone defect healing via Multiphoton Laser Scanning Microscopy (MPLSM). By simultaneously probing new bone matrix via second harmonic generation (SHG), neovascular networks via intravenous perfusion of fluorophore, and osteoblast differentiation via 2.3kb collagen type I promoter driven GFP (Col2.3GFP), we examined the morphogenetic sequence of cranial bone defect healing and further established the spatiotemporal analyses of osteogenesis and angiogenesis coupling in repair and regeneration. We demonstrated that bone defect closure was initiated in the residual bone around the edge of the defect. The expansion and migration of osteoprogenitors into the bone defect occurred during the first 3 weeks of healing, coupled with vigorous microvessel angiogenesis at the leading edge of the defect. Subsequent bone repair was marked by matrix deposition and active vascular network remodeling within new bone. Implantation of bone marrow stromal cells (BMSCs) isolated from Col2.3GFP mice further showed that donor-dependent bone formation occurred rapidly within the first 3 weeks of implantation, in concert with early angiogenesis. The subsequent bone wound closure was largely host-dependent, associated with localized modest induction of angiogenesis. The establishment of a live imaging platform via cranial window provides a unique tool to understand osteogenesis and angiogenesis in repair and regeneration, enabling further elucidation of the spatiotemporal regulatory mechanisms of osteoprogenitor cell interactions

  14. Effects of implantation of three-dimensional engineered bone tissue with a vascular-like structure on repair of bone defects

    NASA Astrophysics Data System (ADS)

    Nishi, Masanori; Matsumoto, Rena; Dong, Jian; Uemura, Toshimasa

    2012-12-01

    Previously, to create an implantable bone tissue associated with blood vessels, we co-cultured rabbit bone marrow mesenchymal stem cells (MSCs) with MSC-derived endothelial cells (ECs) within a porous polylactic acid-based scaffold utilizing a rotating wall vessel (RWV) bioreactor. Here, this engineered tissue was orthotopically implanted into defects made in femurs of immunodeficient rats, and histological analysis were carried out to examine the repair of the damage and the formation of bone around the implant. The bone defects were better repaired in the implanted group than control group after 3 weeks. The results indicate that the engineered bone could repair bone defects.

  15. Use of bone morphogenetic proteins in mesenchymal stem cell stimulation of cartilage and bone repair

    PubMed Central

    Scarfì, Sonia

    2016-01-01

    The extracellular matrix-associated bone morphogenetic proteins (BMPs) govern a plethora of biological processes. The BMPs are members of the transforming growth factor-β protein superfamily, and they actively participate to kidney development, digit and limb formation, angiogenesis, tissue fibrosis and tumor development. Since their discovery, they have attracted attention for their fascinating perspectives in the regenerative medicine and tissue engineering fields. BMPs have been employed in many preclinical and clinical studies exploring their chondrogenic or osteoinductive potential in several animal model defects and in human diseases. During years of research in particular two BMPs, BMP2 and BMP7 have gained the podium for their use in the treatment of various cartilage and bone defects. In particular they have been recently approved for employment in non-union fractures as adjunct therapies. On the other hand, thanks to their potentialities in biomedical applications, there is a growing interest in studying the biology of mesenchymal stem cell (MSC), the rules underneath their differentiation abilities, and to test their true abilities in tissue engineering. In fact, the specific differentiation of MSCs into targeted cell-type lineages for transplantation is a primary goal of the regenerative medicine. This review provides an overview on the current knowledge of BMP roles and signaling in MSC biology and differentiation capacities. In particular the article focuses on the potential clinical use of BMPs and MSCs concomitantly, in cartilage and bone tissue repair. PMID:26839636

  16. Combination of platelet-rich plasma with polycaprolactone-tricalcium phosphate scaffolds for segmental bone defect repair.

    PubMed

    Rai, Bina; Oest, Megan E; Dupont, Ken M; Ho, Kee H; Teoh, Swee H; Guldberg, Robert E

    2007-06-15

    Porous scaffold biomaterials may offer a clinical alternative to bone grafts; however, scaffolds alone are typically insufficient to heal large bone defects. Numerous studies have demonstrated that osteoinductive growth factor or gene delivery significantly improves bone repair. However, given the important role of vascularization during bone regeneration, it may also be beneficial to incorporate factors that promote vascular ingrowth into constructs. In this study, a strategy combining structural polycaprolactone-20% tricalcium phosphate (PCL-TCP) composite scaffolds with platelet-rich plasma (PRP) was tested. Following bilateral implantation of constructs into 8 mm rat nonunion femoral defects, 3D vascular and bone ingrowth were quantified at 3 and 12 weeks using contrast-enhanced microcomputed tomography (micro-CT) imaging. At week 3, PRP-treated femurs displayed 70.3% higher vascular volume fraction than control femurs. Interestingly, bone volume fraction (BVF) was significantly higher for the empty scaffold group at the early time point. At 12 weeks, BVF measurements between the two groups were statistically equivalent. However, a greater proportion of PRP-treated femurs (83%) achieved bone union as compared to empty scaffold controls (33%). Consistent with this observation, biomechanical evaluation of functional integration also revealed a significantly higher torsional stiffness observed for PRP-treated defects compared to empty scaffolds. Ultimate torque at failure was not improved, however, perhaps due to the slow resorption profile of the scaffold material. Histological evaluation illustrated infiltration of vascularized connective tissue and bone in both groups. Given that bone ingrowth into untreated defects in this model is minimal, PCL-TCP scaffolds were clearly able to promote bone ingrowth but failed to consistently bridge the defect. The addition of PRP to PCL-TCP scaffolds accelerated early vascular ingrowth and improved longer-term functional

  17. Cell and protein compatible 3D bioprinting of mechanically strong constructs for bone repair.

    PubMed

    Sawkins, M J; Mistry, P; Brown, B N; Shakesheff, K M; Bonassar, L J; Yang, J

    2015-09-01

    Rapid prototyping of bone tissue engineering constructs often utilizes elevated temperatures, organic solvents and/or UV light for materials processing. These harsh conditions may prevent the incorporation of cells and therapeutic proteins in the fabrication processes. Here we developed a method for using bioprinting to produce constructs from a thermoresponsive microparticulate material based on poly(lactic-co-glycolic acid) at ambient conditions. These constructs could be engineered with yield stresses of up to 1.22 MPa and Young's moduli of up to 57.3 MPa which are within the range of properties of human cancellous bone. Further study showed that protein-releasing microspheres could be incorporated into the bioprinted constructs. The release of the model protein lysozyme from bioprinted constructs was sustainted for a period of 15 days and a high degree of protein activity could be measured up to day 9. This work suggests that bioprinting is a viable route to the production of mechanically strong constructs for bone repair under mild conditions which allow the inclusion of viable cells and active proteins. PMID:26133398

  18. Cell and protein compatible 3D bioprinting of mechanically strong constructs for bone repair.

    PubMed

    Sawkins, M J; Mistry, P; Brown, B N; Shakesheff, K M; Bonassar, L J; Yang, J

    2015-07-02

    Rapid prototyping of bone tissue engineering constructs often utilizes elevated temperatures, organic solvents and/or UV light for materials processing. These harsh conditions may prevent the incorporation of cells and therapeutic proteins in the fabrication processes. Here we developed a method for using bioprinting to produce constructs from a thermoresponsive microparticulate material based on poly(lactic-co-glycolic acid) at ambient conditions. These constructs could be engineered with yield stresses of up to 1.22 MPa and Young's moduli of up to 57.3 MPa which are within the range of properties of human cancellous bone. Further study showed that protein-releasing microspheres could be incorporated into the bioprinted constructs. The release of the model protein lysozyme from bioprinted constructs was sustainted for a period of 15 days and a high degree of protein activity could be measured up to day 9. This work suggests that bioprinting is a viable route to the production of mechanically strong constructs for bone repair under mild conditions which allow the inclusion of viable cells and active proteins.

  19. The Application of Fiber-Reinforced Materials in Disc Repair

    PubMed Central

    Pei, Bao-Qing; Li, Hui; Zhu, Gang; Li, De-Yu; Fan, Yu-Bo; Wu, Shu-Qin

    2013-01-01

    The intervertebral disc degeneration and injury are the most common spinal diseases with tremendous financial and social implications. Regenerative therapies for disc repair are promising treatments. Fiber-reinforced materials (FRMs) are a kind of composites by embedding the fibers into the matrix materials. FRMs can maintain the original properties of the matrix and enhance the mechanical properties. By now, there are still some problems for disc repair such as the unsatisfied static strength and dynamic properties for disc implants. The application of FRMs may resolve these problems to some extent. In this review, six parts such as background of FRMs in tissue repair, the comparison of mechanical properties between natural disc and some typical FRMs, the repair standard and FRMs applications in disc repair, and the possible research directions for FRMs' in the future are stated. PMID:24383057

  20. New Materials for the Repair of Polyimide Electrical Wire Insulation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Two viable polyimide backbone materials have been identified that will allow the repair of polyimide electrical wire insulation found on the Space Shuttle and other aging aircraft. This identification is the outcome of ongoing efforts to assess the viability of using such polyimides and polyimide precursors (polyamic acids [PAAs]) as repair materials for aging polyimide electrical wire insulation. These repair materials were selected because they match the chemical makeup of the underlying wire insulation as closely as possible. This similarity allows for maximum compatibility, coupled with the outstanding physical properties of polyimides. The two polyimide backbone materials allow the polymer to be extremely flexible and to melt at low temperatures. A polymer chain end capping group that allows the polymer to crosslink into a nonflowable repair upon curing at around 200 C was also identified.

  1. Lightweight Material Patches Allow for Quick Repairs

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Cornerstone Research Group Inc., of Dayton, Ohio, has been the recipient of 16 Small Business Innovation Research (SBIR) contracts with NASA with a variety of different focuses, including projects like creating inflatable structures for radio frequency antennas and, most recently, healable polymer matrix composites for future space vehicles. One of its earlier SBIR contracts, with Kennedy Space Center, led to the development of a new type of structural patch for a variety of consumer uses: Rubbn Repair, for automotive uses; and Rec Repair for the outdoors and adventure market. Both are flexible, heat-activated structural patches.

  2. Effect of low-level laser therapy on repair of the bone compromised by radiotherapy.

    PubMed

    Batista, Jonas D; Zanetta-Barbosa, Darceny; Cardoso, Sérgio V; Dechichi, Paula; Rocha, Flaviana S; Pagnoncelli, Rogério M

    2014-11-01

    Radiotherapy (RDT) is commonly used for cancer treatment, but high doses of ionizing radiation can directly affect healthy tissues. Positive biological effects of low-level laser therapy (LLLT) on bone repair have been demonstrated; however, this effect on surgical defects of bone previously compromised by radiotherapy has not been evaluated. The aim of this study was to investigate the influence of LLLT (λ = 830 nm) in femur repair after ionizing radiation. Twenty Wistar rats were divided into four groups: control group (GC, n = 5) creation of bone defects (BDs) only; laser group (GL), with BD and LLLT (n = 5); radiotherapy group (GR), submitted to RDT and BD (n = 5); and radiotherapy and laser group (GRL), submitted to RDT, BD, and LLLT (n = 5). GL and GRL received punctual laser application (DE = 210 J/cm(2), P = 50 mW, t = 120 s, and beam diameter of 0.04 cm(2)) immediately after surgery, with 48-h interval during 7 days. Animals were euthanized at 7 days after surgery, and bone sections were evaluated morphometrically with conventional microscopy. Bone repair was only observed in nonirradiated bone, with significant improvement in GL in comparison to GC. GR and GRL did not present any bone neoformation. The result demonstrated a positive local biostimulative effect of LLLT in normal bone. However, LLLT was not able to revert the bone metabolic damage due to ionizing radiation.

  3. Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair

    PubMed Central

    CALASANS-MAIA, Mônica Diuana; de MELO, Bruno Raposo; ALVES, Adriana Terezinha Neves Novellino; RESENDE, Rodrigo Figueiredo de Brito; LOURO, Rafael Seabra; SARTORETTO, Suelen Cristina; GRANJEIRO, José Mauro; ALVES, Gutemberg Gomes

    2015-01-01

    ABSTRACT Objective The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA). Material and Methods The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. Results The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day. Conclusion CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption. PMID:26814461

  4. Tooth-derived bone graft material

    PubMed Central

    Kim, Young-Kyun; Lee, Junho; Kim, Kyung-Wook; Murata, Masaru; Akazawa, Toshiyuki; Mitsugi, Masaharu

    2013-01-01

    With successful extraction of growth factors and bone morphogenic proteins (BMPs) from mammalian teeth, many researchers have supported development of a bone substitute using tooth-derived substances. Some studies have also expanded the potential use of teeth as a carrier for growth factors and stem cells. A broad overview of the published findings with regard to tooth-derived regenerative tissue engineering technique is outlined. Considering more than 100 published papers, our team has developed the protocols and techniques for processing of bone graft material using extracted teeth. Based on current studies and studies that will be needed in the future, we can anticipate development of scaffolds, homogenous and xenogenous tooth bone grafts, and dental restorative materials using extracted teeth. PMID:24471027

  5. Histomorphometric analysis of the repair process of autogenous bone grafts fixed at rat calvaria with cyanoacrylate

    PubMed Central

    ESTEVES, Jônatas Caldeira; BORRASCA, Albanir Gabriel; ARANEGA, Alessandra Marcondes; GARCIA JUNIOR, Idelmo Rangel; MAGRO FILHO, Osvaldo

    2011-01-01

    Objective The purpose of this study was to perform histological and histometric analyses of the repair process of autogenous bone grafts fixed at rat calvaria with ethyl-cyanoacrylate adhesive. Material and Methods Thirty-two rats were divided into two groups (n=16), Group I - Control and Group II - Adhesive. Osteotomies were made at the right parietal bone for graft obtainment using a 4-mm-diameter trephine drill. Then, the bone segments were fixed with the adhesive in the parietal region of the opposite side to the donor site. After 10 and 30 days, 8 animals of each group were euthanized and the calvarias were laboratorially processed for obtaining hematoxylin and eosin-stained slides for histological and histometric analyses. Results An intense inflammatory reaction was observed at the 10-day period. At 30 days, this reaction was less intense, despite the presence of adhesive at the recipient-site/graft interface. Graft incorporation to the recipient site was observed only at the control group, which maintained the highest graft size at 10 and 30 days. Conclusions Although the fragment was stable, the presence of adhesive in Group II did not allow graft incorporation to the recipient site, determining a localized, discrete and persistent inflammatory reaction. PMID:21986659

  6. Multifunctional materials for bone cancer treatment

    PubMed Central

    Marques, Catarina; Ferreira, José MF; Andronescu, Ecaterina; Ficai, Denisa; Sonmez, Maria; Ficai, Anton

    2014-01-01

    The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen–hydroxyapatite composites used for skin and bone cancer treatments. The multi-functionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative), cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin), silver nanoparticles, antibiotics (anthracyclines, geldanamycin), and/or analgesics (ibuprofen, fentanyl). The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management) in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies. PMID:24920907

  7. In-situ hardening hydroxyapatite-based scaffold for bone repair.

    PubMed

    Zhang, Yu; Xu, Hockin H K; Takagi, Shozo; Chow, Laurence C

    2006-05-01

    Musculoskeletal conditions are becoming a major health concern because of an aging population and sports- and traffic-related injuries. While sintered hydroxyapatite implants require machining, calcium phosphate cement (CPC) bone repair material is moldable, self-hardens in situ, and has excellent osteoconductivity. In the present work, new approaches for developing strong and macroporous scaffolds of CPC were tested. Relationships were determined between scaffold porosity and strength, elastic modulus and fracture toughness. A biocompatible and biodegradable polymer (chitosan) and a water-soluble porogen (mannitol) were incorporated into CPC: Chitosan to make the material stronger, fast-setting and anti-washout; and mannitol to create macropores. Flexural strength, elastic modulus, and fracture toughness were measured as functions of mannitol mass fraction in CPC from 0% to 75%. After mannitol dissolution in a physiological solution, macropores were formed in CPC in the shapes of the original entrapped mannitol crystals, with diameters of 50 microm to 200 microm for cell infiltration and bone ingrowth. The resulting porosity in CPC ranged from 34.4% to 83.3% volume fraction. At 70.2% porosity, the hydroxyapatite scaffold possessed flexural strength (mean +/- sd; n = 6) of (2.5 +/- 0.2) MPa and elastic modulus of (0.71 +/- 0.10) GPa. These values were within the range for sintered porous hydroxyapatite and cancellous bone. Predictive equations were established by regression power-law fitting to the measured data (R(2) > 0.98) that described the relationships between scaffold porosity and strength, elastic modulus and fracture toughness. In conclusion, a new graft composition was developed that could be delivered during surgery in the form of a paste to harden in situ in the bone site to form macroporous hydroxyapatite. Compared to conventional CPC without macropores, the increased macroporosity of the new apatite scaffold may help facilitate implant fixation and

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

    PubMed

    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. PMID:27567780

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

    PubMed

    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.

  10. Propofol promotes spinal cord injury repair by bone marrow mesenchymal stem cell transplantation

    PubMed Central

    Zhou, Ya-jing; Liu, Jian-min; Wei, Shu-ming; Zhang, Yun-hao; Qu, Zhen-hua; Chen, Shu-bo

    2015-01-01

    Propofol is a neuroprotective anesthetic. Whether propofol can promote spinal cord injury repair by bone marrow mesenchymal stem cells remains poorly understood. We used rats to investigate spinal cord injury repair using bone marrow mesenchymal stem cell transplantation combined with propofol administration via the tail vein. Rat spinal cord injury was clearly alleviated; a large number of newborn non-myelinated and myelinated nerve fibers appeared in the spinal cord, the numbers of CM-Dil-labeled bone marrow mesenchymal stem cells and fluorogold-labeled nerve fibers were increased and hindlimb motor function of spinal cord-injured rats was markedly improved. These improvements were more prominent in rats subjected to bone marrow mesenchymal cell transplantation combined with propofol administration than in rats receiving monotherapy. These results indicate that propofol can enhance the therapeutic effects of bone marrow mesenchymal stem cell transplantation on spinal cord injury in rats. PMID:26487860

  11. The reaction of the dura to bone morphogenetic protein (BMP) in repair of skull defects.

    PubMed Central

    Takagi, K; Urist, M R

    1982-01-01

    Trephine defects in the adult rat skull 0.8 cm in diameter, which do not spontaneously heal, were filled with a bovine bone morphogenetic protein (BMP) fraction. The defects healed not only by bony ingrowth from the trephine rim, but also by proliferation of pervascular mesenchymal-type cells (pericytes) of the dura mater. Under the influence of BMP, dural pericytes differentiated into chondroid and woven bone. Between three and four weeks postimplantation, sinusoids formed and the woven bone remodelled into lamellar bone. Concurrently, blood-borne bone marrow cells colonized the bone deposits, and the diploe were restored. Demonstrating that it is soluble in interstitial fluid, and diffusible across a nucleopore membrane (which isolated the bony margins of the skull), BMP induced new bone formation in the underlying dura and complete repair of the defect. The response of the dura to the BMP fraction produced more new bone than the response to allogeneic bone matrix. The BMP-induced repair was dose dependent; the quantity of new bone was proportional to the dose of the implanted BMP. Images Fig. 1a. Fig. 1b. Fig. 1c. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 8. Fig. 9. PMID:7092346

  12. Low-level laser therapy on bone repair: is there any effect outside the irradiated field?

    PubMed

    Batista, Jonas Dantas; Sargenti-Neto, Sérgio; Dechichi, Paula; Rocha, Flaviana Soares; Pagnoncelli, Rogério Miranda

    2015-07-01

    The biological effects of local therapy with laser on bone repair have been well demonstrated; however, this possible effect on bone repair outside the irradiated field has not been evaluated. The aim of this study was to investigate the effect of low-level laser therapy (LLLT) (λ = 830 nm) on repair of surgical bone defects outside the irradiated field, in rats. Sixty Wistar rats were submitted to osteotomy on the left femur and randomly separated into four groups (n = 15): group I, control, bone defect only; group II, laser applied on the right femur (distant dose); group III, laser applied locally on the bone defect and also on the right femur (local and distant doses); and group IV, laser applied locally on the left femur (local dose). Laser groups received applications within a 48-h interval in one point per session of density energy (DE) = 210 J/cm(2), P = 50 mW, t = 120 s, and beam diameter of 0.028 cm. Five animals of each group were euthanized 7, 15, and 21 days after surgery. Histologic analysis in all groups showed new bone formation in the region of interest (ROI) at 7 days. After 15 days, bone remodeling with a decrease of bone neoformation in the marrow area was observed in all groups. After 21 days, advanced bone remodeling with new bone mostly located in the cortical area was observed. The histomorphometric analysis showed at 7 days a significant increase of bone formation in groups III and IV compared to groups I and II. At days 15 and 21, histomorphometric analysis showed no significant differences between them. Laser therapy presented a positive local biostimulative effect in the early stage of bone healing, but the LLLT effect was not observed a long distance from the evaluated area.

  13. The materials used in bone tissue engineering

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  14. The materials used in bone tissue engineering

    SciTech Connect

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

    2015-11-17

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

  15. Yap1 Regulates Multiple Steps of Chondrocyte Differentiation during Skeletal Development and Bone Repair.

    PubMed

    Deng, Yujie; Wu, Ailing; Li, Pikshan; Li, Gang; Qin, Ling; Song, Hai; Mak, Kinglun Kingston

    2016-03-01

    Hippo signaling controls organ size and tissue regeneration in many organs, but its roles in chondrocyte differentiation and bone repair remain elusive. Here, we demonstrate that Yap1, an effector of Hippo pathway inhibits skeletal development, postnatal growth, and bone repair. We show that Yap1 regulates chondrocyte differentiation at multiple steps in which it promotes early chondrocyte proliferation but inhibits subsequent chondrocyte maturation both in vitro and in vivo. Mechanistically, we find that Yap1 requires Teads binding for direct regulation of Sox6 expression to promote chondrocyte proliferation. In contrast, Yap1 inhibits chondrocyte maturation by suppression of Col10a1 expression through interaction with Runx2. In addition, Yap1 also governs the initiation of fracture repair by inhibition of cartilaginous callus tissue formation. Taken together, our work provides insights into the mechanism by which Yap1 regulates endochondral ossification, which may help the development of therapeutic treatment for bone regeneration.

  16. Bone Repair on Fractures Treated with Osteosynthesis, ir Laser, Bone Graft and Guided Bone Regeneration: Histomorfometric Study

    NASA Astrophysics Data System (ADS)

    dos Santos Aciole, Jouber Mateus; dos Santos Aciole, Gilberth Tadeu; Soares, Luiz Guilherme Pinheiro; Barbosa, Artur Felipe Santos; Santos, Jean Nunes; Pinheiro, Antonio Luiz Barbosa

    2011-08-01

    The aim of this study was to evaluate, through the analysis of histomorfometric, the repair of complete tibial fracture in rabbits fixed with osteosynthesis, treated or not with infrared laser light (λ780 nm, 50 mW, CW) associated or not to the use of hydroxyapatite and guided bone regeneration (GBR). Surgical fractures were created, under general anesthesia (Ketamina 0,4 ml/Kg IP and Xilazina 0,2 ml/Kg IP), on the dorsum of 15 Oryctolagus rabbits that were divided into 5 groups and maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet and had water ad libidum. On groups II, III, IV and V the fracture was fixed with wire osteosynthesis. Animals of groups III and V were grafted with hydroxyapatite and GBR technique used. Animals of groups IV and V were irradiated at every other day during two weeks (16 J/cm2, 4×4 J/cm2). Observation time was that of 30 days. After animal death (overdose of general anesthetics) the specimes were routinely processed to wax and underwent histological analysis by light microscopy. The histomorfometric analysis showed an increased bone neoformation, increased collagen deposition, less reabsorption and inflammation when laser was associated to the HATCP. It is concluded that IR laser light was able to accelerate fracture healing and the association with HATCP and GBR resulted on increased deposition of CHA.

  17. Augmenting endothelial repair in diabetes: role of bone marrow-derived cells.

    PubMed

    Gilbert, Richard E

    2013-10-01

    Endothelial loss, a consequence of both higher rates of apoptosis and diminished repair, is a major factor in the pathogenesis of diabetes complications. Although the repair process previously was viewed to arise primarily from the proliferation and migration of neighbouring endothelial cells, it now has become evident that certain bone marrow-derived cells contribute substantially to this process. Unfortunately, both the number and function of such cells are reduced in diabetes. Here, we first review the effects of current therapies on angiogenic bone marrow-derived cells and then explore future strategies to augment their number and function, aiming to reduce both the microvascular and macrovascular complications of diabetes.

  18. Porous alumina, zirconia and alumina/zirconia for bone repair: fabrication, mechanical and in vitro biological response.

    PubMed

    Hadjicharalambous, Chrystalleni; Buyakov, Ales; Buyakova, Svetlana; Kulkov, Sergey; Chatzinikolaidou, Maria

    2015-04-23

    Zirconia (ZrO2) and alumina (Al2O3) based ceramics are widely used for load-bearing applications in bone repair due to their excellent mechanical properties and biocompatibility. They are often regarded as bioinert since no direct bone-material interface is created unless a porous structure intercedes, leading to better bone bonding. In this regard, investigating interactions between cells and porous ceramics is of great interest. In the present study, we report on the successful fabrication of sintered alumina A-61, zirconia Z-50 and zirconia/alumina composite ZA-60 ceramics with medium porosities of 61, 50 and 60%, respectively, indicating a bimodal pore size distribution and good interconnectivity. They exhibit elastic moduli of 3-10 GPa and compressive strength values of 60-240 MPa, similar to those of human cortical bone.We performed in vitro cell-material investigations comparing the adhesion, proliferation and differentiation of mouse pre-osteoblasts MC3T3-E1 on the three porous materials. While all three ceramics demonstrate a strong cell attachment, better cell spreading is observed on zirconia-containing substrates. Significantly higher cell growth was quantified on the latter ceramics, revealing an increased alkaline phosphatase activity, higher collagen production and increased calcium biomineralization compared to A-61. Hence, these porous zirconia-containing ceramics elicit superior biological responses over porous alumina of similar porosity, promoting enhanced biological interaction, with potential use as non-degradable bone grafts or as implant coatings.

  19. Direct Ink Writing of Highly Porous and Strong Glass Scaffolds for Load-bearing Bone Defects Repair and Regeneration

    PubMed Central

    Fu, Qiang; Saiz, Eduardo; Tomsia, Antoni P.

    2011-01-01

    The quest for synthetic materials to repair load-bearing bone lost because of trauma, cancer, or congenital bone defects requires development of porous and high-performance scaffolds with exceptional mechanical strength. However, the low mechanical strength of porous bioactive ceramic and glass scaffolds, compared with that of human cortical bone, has limited their use for these applications. In the present work, bioactive 6P53B glass scaffolds with superior mechanical strength were fabricated using a direct ink writing technique. The rheological properties of Pluronic® F-127 (referred to hereafter simply as F-127) hydrogel-based inkswere optimized for the printing of features as fine as 30 μm and of the three-dimensional scaffolds. The mechanical strength and in vitro degradation of the scaffolds were assessed in a simulated body fluid (SBF). The sintered glass scaffolds show a compressive strength (136 ± 22 MPa) comparable to that of human cortical bone (100-150 MPa), while the porosity (60%) is in the range of that of trabecular bone (50-90%).The strength is ~100 times that of polymer scaffolds and 4–5 times that of ceramic and glass scaffolds with comparable porosities. Despite the strength decrease resulting from weight loss during immersion in an SBF, the value (77 MPa) is still far above that of trabecular bone after three weeks. The ability to create both porous and strong structures opens a new avenue for fabricating scaffolds for load-bearing bone defect repair and regeneration. PMID:21745606

  20. Amifostine Prophylaxis on Bone Densitometry, Biomechanical Strength and Union in Mandibular Pathologic Fracture Repair

    PubMed Central

    Tchanque-Fossuo, Catherine N.; Donneys, Alexis; Sarhaddi, Deniz; Poushanchi, Behdod; Deshpande, Sagar S.; Weiss, Daniela M.

    2013-01-01

    Background Pathologic fractures (Fx) of the mandibles are severely debilitating consequences of radiation (XRT) in the treatment of craniofacial malignancy. We have previously demonstrated Amifostine’s effect (AMF) in the remediation of radiation-induced cellular damage. We posit that AMF prophylaxis will preserve bone strength and drastically reverse radiotherapy-induced non-union in a murine mandibular model of pathologic fracture repair. Materials and Methods Twenty-nine rats were randomized into 3 groups: Fx, XRT/Fx, and AMF/XRT/Fx. A fractionated human equivalent dose of radiation was delivered to the left hemimandibles of XRT/Fx and AMF/XRT/Fx. AMF/XRT/Fx was pre-treated with AMF. All groups underwent left mandibular osteotomy with external fixation and setting of a 2.1mm fracture gap post-operatively. Utilizing micro-computed tomography and biomechanical testing, the healed fracture was evaluated for strength. Results All radiomorphometrics and biomechanical properties were significantly diminished in XRT/Fx compared to both Fx and AMF/XRT/Fx. No difference was demonstrated between Fx and AMF/XRT/Fx in both outcomes. Conclusion Our investigation establishes the significant and substantial capability of AMF prophylaxis to preserve and enhance bone union, quality and strength in the setting of human equivalent radiotherapy. Such novel discoveries establish the true potential to utilize pharmacotherapy to prevent and improve the treatment outcomes of radiation-induced late pathologic fractures. PMID:23860272

  1. Vascularized rotational temporal bone flap for repair of anterior skull base defects: a novel operative technique.

    PubMed

    Zeiler, Frederick A; Kaufmann, Anthony M

    2015-11-01

    Repair of anterior skull base defects with vascularized grafts poses a significant challenge, given the location and small number of adequately sized vessels for free-flap anastomosis. This is particularly the case in the setting of redo surgery or in patients with preexisting soft-tissue trauma. Even more difficult is achieving a vascularized bone flap closure of such bony defects. The authors report a novel technique involving a rotational temporal bone flap with a temporalis muscle vascularized pedicle, which was used to repair an anterior fossa bony and soft-tissue defect created by recurrent malignancy. A 55-year-old man with history of scalp avulsion during a motor vehicle accident, anterior fossa/nasopharyngeal malignant neuroendocrine carcinoma postresection, and bone flap infection presented with a recurrence of his skull base malignancy. The tumor was located in the anterior fossa, extending interhemispherically and down through the cribriform plate, ethmoid air cells, and extending into the nasopharyngeal cavity. Resection of the recurrent tumor was performed. The bony defect in the anterior skull base was repaired with a novel vascularized rotational temporal bone flap, with acceptable separation of the nasopharynx from the intracranial cavity. The vascularized rotational temporal bone flap, in which a temporalis muscle pedicle is used, provides a novel and easily accessible means of vascularized bone closure of anterior skull base defects without the need for microsurgical free-flap grafting.

  2. Transplanted Bone Marrow Cells Repair Heart Tissue and Reduce Myocarditis in Chronic Chagasic Mice

    PubMed Central

    Soares, Milena B. P.; Lima, Ricardo S.; Rocha, Leonardo L.; Takyia, Christina M.; Pontes-de-Carvalho, Lain; Campos de Carvalho, Antonio C.; Ribeiro-dos-Santos, Ricardo

    2004-01-01

    A progressive destruction of the myocardium occurs in ∼30% of Trypanosoma cruzi-infected individuals, causing chronic chagasic cardiomyopathy, a disease so far without effective treatment. Syngeneic bone marrow cell transplantation has been shown to cause repair and improvement of heart function in a number of studies in patients and animal models of ischemic cardiopathy. The effects of bone marrow transplant in a mouse model of chronic chagasic cardiomyopathy, in the presence of the disease causal agent, ie, the T. cruzi, are described herein. Bone marrow cells injected intravenously into chronic chagasic mice migrated to the heart and caused a significant reduction in the inflammatory infiltrates and in the interstitial fibrosis characteristics of chronic chagasic cardiomyopathy. The beneficial effects were observed up to 6 months after bone marrow cell transplantation. A massive apoptosis of myocardial inflammatory cells was observed after the therapy with bone marrow cells. Transplanted bone marrow cells obtained from chagasic mice and from normal mice had similar effects in terms of mediating chagasic heart repair. These results show that bone marrow cell transplantation is effective for treatment of chronic chagasic myocarditis and indicate that autologous bone marrow transplant may be used as an efficient therapy for patients with chronic chagasic cardiomyopathy. PMID:14742250

  3. Helium-neon laser improves bone repair in rabbits: comparison at two anatomic sites.

    PubMed

    Peccin, Maria Stella; de Oliveira, Flavia; Muniz Renno, Ana Claudia; Pacheco de Jesus, Gustavo Protasio; Pozzi, Renan; Gomes de Moura, Carolina Foot; Giusti, Paulo Ricardo; Ribeiro, Daniel Araki

    2013-07-01

    The purpose of this study was to evaluate the influence of helium-neon laser on bone repair of femur and tibia in rabbits. For this purpose, 15 New Zealand rabbits underwent bilateral bone damage (tibia and femur) using a spherical bur. Helium-neon laser light, at a fluency of 6 J∕cm(2) and wavelength of 632.8 nm was applied on the left legs (laser group). The right tibia or femur lesions (control group) served as negative control. All sections were histopathologically analyzed using HE sections and the morphometric data from bone tissue and hyaline cartilage were achieved. Histopathological analysis showed regular bone trabeculae covered by osteoblastic cells after 1 week in the group exposed to laser therapy from femur and tibia indistinctly. After 3 weeks, the laser group showed new bone formation coming from the bony walls in the femur and tibia as well. On the 5th week, well-defined trabecula undergoing remodeling process was detected for the most intense pattern in tibia only. Morphometric analysis revealed significant statistical differences (p < 0.05) in the bone tissue for the laser-exposed group on 1st and 3rd weeks. After 5th week, bone formation was increased to tibia only. Taken together, such findings suggest that helium-neon laser is able to improve bone repair in rabbits being the most pronounced effect in tibia. PMID:23053246

  4. Helium-neon laser improves bone repair in rabbits: comparison at two anatomic sites.

    PubMed

    Peccin, Maria Stella; de Oliveira, Flavia; Muniz Renno, Ana Claudia; Pacheco de Jesus, Gustavo Protasio; Pozzi, Renan; Gomes de Moura, Carolina Foot; Giusti, Paulo Ricardo; Ribeiro, Daniel Araki

    2013-07-01

    The purpose of this study was to evaluate the influence of helium-neon laser on bone repair of femur and tibia in rabbits. For this purpose, 15 New Zealand rabbits underwent bilateral bone damage (tibia and femur) using a spherical bur. Helium-neon laser light, at a fluency of 6 J∕cm(2) and wavelength of 632.8 nm was applied on the left legs (laser group). The right tibia or femur lesions (control group) served as negative control. All sections were histopathologically analyzed using HE sections and the morphometric data from bone tissue and hyaline cartilage were achieved. Histopathological analysis showed regular bone trabeculae covered by osteoblastic cells after 1 week in the group exposed to laser therapy from femur and tibia indistinctly. After 3 weeks, the laser group showed new bone formation coming from the bony walls in the femur and tibia as well. On the 5th week, well-defined trabecula undergoing remodeling process was detected for the most intense pattern in tibia only. Morphometric analysis revealed significant statistical differences (p < 0.05) in the bone tissue for the laser-exposed group on 1st and 3rd weeks. After 5th week, bone formation was increased to tibia only. Taken together, such findings suggest that helium-neon laser is able to improve bone repair in rabbits being the most pronounced effect in tibia.

  5. Comparison of autogenic and allogenic bone marrow derived mesenchymal stem cells for repair of segmental bone defects in rabbits.

    PubMed

    Udehiya, Rahul Kumar; Amarpal; Aithal, H P; Kinjavdekar, P; Pawde, A M; Singh, Rajendra; Taru Sharma, G

    2013-06-01

    Autogenic and allogenic bone marrow derived mesenchymal stem cells (BM-MSCs) were compared for repair of bone gap defect in rabbits. BM-MSCs were isolated from bone marrow aspirates and cultured in vitro for allogenic and autogenic transplantation. A 5mm segmental defect was created in mid-diaphysis of the radius bone. The defect was filled with hydroxyapatite alone, hydroxyapatite with autogeneic BM-MSCs and hydroxyapatite with allogenic BM-MSCs in groups A, B and C, respectively. On an average 3.45×10(6) cells were implanted at each defect site. Complete bridging of bone gap with newly formed bone was faster in both treatment groups as compared to control group. Histologically, increased osteogenesis, early and better reorganization of cancellous bone and more bone marrow formation were discernible in treatment groups as compared to control group. It was concluded that in vitro culture expanded allogenic and autogenic BM-MSCs induce similar, but faster and better healing as compared to control.

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

    PubMed Central

    Ohtsuki, Chikara; Kamitakahara, Masanobu; Miyazaki, Toshiki

    2009-01-01

    Bioactive ceramics have been used clinically to repair bone defects owing to their biological affinity to living bone; i.e. the capability of direct bonding to living bone, their so-called bioactivity. However, currently available bioactive ceramics do not satisfy every clinical application. Therefore, the development of novel design of bioactive materials is necessary. Bioactive ceramics show osteoconduction by formation of biologically active bone-like apatite through chemical reaction of the ceramic surface with surrounding body fluid. Hence, the control of their chemical reactivity in body fluid is essential to developing novel bioactive materials as well as biodegradable materials. This paper reviews novel bioactive materials designed based on chemical reactivity in body fluid. PMID:19158015

  7. Diode λ830nm laser associated with hydroxyapatite and biological membranes: bone repair in rats

    NASA Astrophysics Data System (ADS)

    Carneiro, Vanda S. M.; Limeira, Francisco d. A.; Gerbi, Marleny E. M.; Menezes, Rebeca F. d.; Santos-Neto, Alexandrino P. d.; Araújo, Natália C.

    2016-02-01

    The aim of the present study was to histologically assess the effect of laser therapy (AsGaAl, 830nm, 40mW, CW, φ ~0,6mm, 16J/cm2 per session, four points of 4J/cm2) on the repair of surgical defects created in the femur of Wistar rats. Background data: Several techniques have been proposed for the correction of bone defects, including the use of grafts and membranes. Despite the increase in the use of laser therapy for the biomodulation of bone repair, very few studies have assessed the associations between laser light and biomaterials. Method: The defects were filled with synthetic micro granular hydroxyapatite (HA) Gen-phos® implants and associated with bovine bone membranes (Gen-derm®). Surgical bone defects were created in 48 rats and divided into four groups: Group IA (control, n=12); Group IB (laser, n=12); Group IIA (HA + membrane, n=12); Group IIB (HA + membrane + laser, n=12). The irradiated groups received the first irradiation immediately after surgery. This radiation was then repeated seven times every 48h. The animals were sacrificed after 15, 21, and 30 days. Results: When comparing the groups irradiated with implants and membranes, it was found that the repair of the defects submitted to laser therapy occurred more quickly, starting 15 and 21 days after surgery. By the 30th day, the level of repair of the defects was similar in the irradiated and the non-irradiated groups. New bone formation was confirmed inside the cavity by the implant's osteoconduction. In the irradiated groups, there was an increment of this new bone formation. Conclusions: In conclusion, the use of laser therapy, particularly when associated with hydroxyapatite and biological membranes, produced a positive biomodulation effect on the healing process of bone defects on the femurs of rats.

  8. A novel technique of lumbar hernia repair using bone anchor fixation.

    PubMed

    Carbonell, A M; Kercher, K W; Sigmon, L; Matthews, B D; Sing, R F; Kneisl, J S; Heniford, B T

    2005-03-01

    Lumbar hernias are difficult to repair due to their proximity to bone and inadequate surrounding tissue to buttress the repair. We analyzed the outcome of patients undergoing a novel retromuscular lumbar hernia repair technique. The repair was performed in ten patients using a polypropylene or polytetrafluoroethylene mesh placed in an extraperitoneal, retromuscular position with at least 5 cm overlap of the hernia defect. The mesh was fixed with circumferential, transfascial, permanent sutures and inferiorly fixed to the iliac crest by suture bone anchors. Five hernias were recurrent, and five were incarcerated; seven were incisional hernias, and three were posttraumatic. Back and abdominal pain was the most common presenting symptom. Mean hernia size was 227 cm(2) (60-504) with a mesh size of 620 cm(2) (224-936). Mean operative time was 181 min (120-269), with a mean blood loss of 128 ml (50-200). Mean length of stay was 5.2 days (2-10), and morphine equivalent requirement was 200 mg (47-460). There were no postoperative complications or deaths. After a mean follow-up of 40 months (3-99) there have been no recurrences. Our sublay repair of lumbar hernias with permanent suture fixation is safe and to date has resulted in no recurrences. Suture bone anchors ensure secure fixation of the mesh to the iliac crest and may eliminate a common area of recurrence.

  9. Editorial Commentary: Save the Subchondral Bone in Rotator Cuff Repair Greater Tuberosity Preparation.

    PubMed

    Brand, Jefferson C

    2016-04-01

    Results from a recent investigation into the practice of greater tuberosity decortication before rotator cuff repair showed that decortication significantly reduced the ultimate failure load. Although the potential of greater tuberosity treatment for solving the rotator cuff healing quandary still exists, the biomechanics are clear, one should not decorticate the greater tuberosity to cancellous bone. PMID:27039677

  10. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pacemaker repair or replacement material. 870.3710 Section 870.3710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710...

  11. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker repair or replacement material. 870.3710 Section 870.3710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710...

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

    PubMed Central

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

    2014-01-01

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

  13. Histomorphometric and ultrastructural analysis of the tendon-bone interface after rotator cuff repair in a rat model.

    PubMed

    Kanazawa, Tomonoshin; Gotoh, Masafumi; Ohta, Keisuke; Honda, Hirokazu; Ohzono, Hiroki; Shimokobe, Hisao; Shiba, Naoto; Nakamura, Kei-Ichiro

    2016-01-01

    Successful rotator cuff repair requires biological anchoring of the repaired tendon to the bone. However, the histological structure of the repaired tendon-bone interface differs from that of a normal tendon insertion. We analysed differences between the normal tendon insertion and the repaired tendon-bone interface after surgery in the mechanical properties, histomorphometric analysis, and 3-dimensional ultrastructure of the cells using a rat rotator cuff repair model. Twenty-four adult Sprague-Dawley (SD) rats underwent complete cuff tear and subsequent repair of the supraspinatus tendon. The repaired tendon-bone interface was evaluated at 4, 8, and 12 weeks after surgery. At each time point, shoulders underwent micro-computed tomography scanning and biomechanical testing (N = 6), conventional histology and histomorphometric analysis (N = 6), and ultrastructural analysis with focused ion beam/scanning electron microscope (FIB/SEM) tomography (N = 4). We demonstrated that the cellular distribution between the repaired tendon and bone at 12 weeks after surgery bore similarities to the normal tendon insertion. However, the ultrastructure of the cells at any time point had a different morphology than those of the normal tendon insertion. These morphological differences affect the healing process, partly contributing to re-tearing at the repair site. These results may facilitate future studies of the regeneration of a normal tendon insertion. PMID:27647121

  14. Histomorphometric and ultrastructural analysis of the tendon-bone interface after rotator cuff repair in a rat model

    PubMed Central

    Kanazawa, Tomonoshin; Gotoh, Masafumi; Ohta, Keisuke; Honda, Hirokazu; Ohzono, Hiroki; Shimokobe, Hisao; Shiba, Naoto; Nakamura, Kei-ichiro

    2016-01-01

    Successful rotator cuff repair requires biological anchoring of the repaired tendon to the bone. However, the histological structure of the repaired tendon-bone interface differs from that of a normal tendon insertion. We analysed differences between the normal tendon insertion and the repaired tendon-bone interface after surgery in the mechanical properties, histomorphometric analysis, and 3-dimensional ultrastructure of the cells using a rat rotator cuff repair model. Twenty-four adult Sprague-Dawley (SD) rats underwent complete cuff tear and subsequent repair of the supraspinatus tendon. The repaired tendon-bone interface was evaluated at 4, 8, and 12 weeks after surgery. At each time point, shoulders underwent micro-computed tomography scanning and biomechanical testing (N = 6), conventional histology and histomorphometric analysis (N = 6), and ultrastructural analysis with focused ion beam/scanning electron microscope (FIB/SEM) tomography (N = 4). We demonstrated that the cellular distribution between the repaired tendon and bone at 12 weeks after surgery bore similarities to the normal tendon insertion. However, the ultrastructure of the cells at any time point had a different morphology than those of the normal tendon insertion. These morphological differences affect the healing process, partly contributing to re-tearing at the repair site. These results may facilitate future studies of the regeneration of a normal tendon insertion. PMID:27647121

  15. Roles of the kidney in the formation, remodeling and repair of bone.

    PubMed

    Wei, Kai; Yin, Zhiwei; Xie, Yuansheng

    2016-06-01

    The relationship between the kidney and bone is highly complex, and the kidney plays an important role in the regulation of bone development and metabolism. The kidney is the major organ involved in the regulation of calcium and phosphate homeostasis, which is essential for bone mineralization and development. Many substances synthesized by the kidney, such as 1,25(OH)2D3, Klotho, bone morphogenetic protein-7, and erythropoietin, are involved in different stages of bone formation, remodeling and repair. In addition, some cytokines which can be affected by the kidney, such as osteoprotegerin, sclerostin, fibroblast growth factor -23 and parathyroid hormone, also play important roles in bone metabolism. In this paper, we summarize the possible effects of these kidney-related cytokines on bone and their possible mechanisms. Most of these cytokines can interact with one another, constituting an intricate network between the kidney and bone. Therefore, kidney diseases should be considered among patients presenting with osteodystrophy and disturbances in bone and mineral metabolism, and treatment for renal dysfunction may accelerate their recovery. PMID:26943181

  16. Long-term safety of antiresorptive treatment: bone material, matrix and mineralization aspects

    PubMed Central

    Misof, Barbara M; Fratzl-Zelman, Nadja; Paschalis, Eleftherios P; Roschger, Paul; Klaushofer, Klaus

    2015-01-01

    It is well established that long-term antiresorptive use is effective in the reduction of fracture risk in high bone turnover osteoporosis. Nevertheless, during recent years, concerns emerged that longer bone turnover reduction might favor the occurrence of fatigue fractures. However, the underlying mechanisms for both beneficial and suspected adverse effects are not fully understood yet. There is some evidence that their effects on the bone material characteristics have an important role. In principle, the composition and nanostructure of bone material, for example, collagen cross-links and mineral content and crystallinity, is highly dependent on tissue age. Bone turnover determines the age distribution of the bone structural units (BSUs) present in bone, which in turn is decisive for its intrinsic material properties. It is noteworthy that the effects of bone turnover reduction on bone material were observed to be dependent on the duration of the antiresorptive therapy. During the first 2–3 years, significant decreases in the heterogeneity of material properties such as mineralization of the BSUs have been observed. In the long term (5–10 years), the mineralization pattern reverts towards normal heterogeneity and degree of mineralization, with no signs of hypermineralization in the bone matrix. Nevertheless, it has been hypothesized that the occurrence of fatigue fractures (such as atypical femoral fractures) might be linked to a reduced ability of microdamage repair under antiresorptive therapy. The present article examines results from clinical studies after antiresorptive, in particular long-term, therapy with the aforementioned potentially positive or negative effects on bone material. PMID:25709811

  17. Amorphous calcium phosphate nanospheres/polylactide composite coated tantalum scaffold: facile preparation, fast biomineralization and subchondral bone defect repair application.

    PubMed

    Zhou, Rong; Xu, Wei; Chen, Feng; Qi, Chao; Lu, Bing-Qiang; Zhang, Hao; Wu, Jin; Qian, Qi-Rong; Zhu, Ying-Jie

    2014-11-01

    Calcium phosphate (CaP) materials are widely used in various biomedical areas such as drug/gene delivery and bone repair/tissue engineering. In this study, amorphous CaP nanospheres synthesized by a simple co-precipitation method are used to prepare the CaP-polylactide (CaP-PLA) composite. Then, the as-prepared CaP-PLA composite is used to coat tantalum (Ta) plates and porous scaffolds. Compared with bare Ta plate, CaP-PLA coated Ta plates show a high performance of surface biomineralization in simulated body fluid (SBF). In addition, the hydrophilicity of the CaP-PLA coated Ta plates is significantly improved. CaP-PLA coated Ta plates with bovine serum albumin (BSA) are prepared and used for the investigation of BSA release in vitro. The experimental results indicate a sustained BSA release property and simultaneous biomineralization of the as-prepared BSA-containing CaP-PLA coated Ta plates. Furthermore, CaP-PLA coated Ta scaffolds are favorable for the human osteoblast-like MG63 cells adhesion and spreading. The vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-containing CaP-PLA coated porous Ta scaffolds are used for the study of rabbit subchondral bone defect repair, covering with autogeneic periosteums. The as-prepared CaP-PLA composite coated Ta scaffolds are useful to guide the bone regeneration in vivo.

  18. Amorphous calcium phosphate nanospheres/polylactide composite coated tantalum scaffold: facile preparation, fast biomineralization and subchondral bone defect repair application.

    PubMed

    Zhou, Rong; Xu, Wei; Chen, Feng; Qi, Chao; Lu, Bing-Qiang; Zhang, Hao; Wu, Jin; Qian, Qi-Rong; Zhu, Ying-Jie

    2014-11-01

    Calcium phosphate (CaP) materials are widely used in various biomedical areas such as drug/gene delivery and bone repair/tissue engineering. In this study, amorphous CaP nanospheres synthesized by a simple co-precipitation method are used to prepare the CaP-polylactide (CaP-PLA) composite. Then, the as-prepared CaP-PLA composite is used to coat tantalum (Ta) plates and porous scaffolds. Compared with bare Ta plate, CaP-PLA coated Ta plates show a high performance of surface biomineralization in simulated body fluid (SBF). In addition, the hydrophilicity of the CaP-PLA coated Ta plates is significantly improved. CaP-PLA coated Ta plates with bovine serum albumin (BSA) are prepared and used for the investigation of BSA release in vitro. The experimental results indicate a sustained BSA release property and simultaneous biomineralization of the as-prepared BSA-containing CaP-PLA coated Ta plates. Furthermore, CaP-PLA coated Ta scaffolds are favorable for the human osteoblast-like MG63 cells adhesion and spreading. The vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-containing CaP-PLA coated porous Ta scaffolds are used for the study of rabbit subchondral bone defect repair, covering with autogeneic periosteums. The as-prepared CaP-PLA composite coated Ta scaffolds are useful to guide the bone regeneration in vivo. PMID:25293870

  19. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen, that is intended to fill, augment, or reconstruct periodontal or bony...

  20. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen, that is intended to fill, augment, or reconstruct periodontal or bony...

  1. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen, that is intended to fill, augment, or reconstruct periodontal or bony...

  2. The role of bone marrow-derived cells in bone fracture repair in a green fluorescent protein chimeric mouse model

    SciTech Connect

    Taguchi, Kazuhiro . E-mail: s3061@nms.ac.jp; Ogawa, Rei; Migita, Makoto; Hanawa, Hideki; Ito, Hiromoto; Orimo, Hideo

    2005-05-27

    We investigated the role of bone marrow cells in bone fracture repair using green fluorescent protein (GFP) chimeric model mice. First, the chimeric model mice were created: bone marrow cells from GFP-transgenic C57BL/6 mice were injected into the tail veins of recipient wild-type C57BL/6 mice that had been irradiated with a lethal dose of 10 Gy from a cesium source. Next, bone fracture models were created from these mice: closed transverse fractures of the left femur were produced using a specially designed device. One, three, and five weeks later, fracture lesions were extirpated for histological and immunohistochemical analyses. In the specimens collected 3 and 5 weeks after operation, we confirmed calluses showing intramembranous ossification peripheral to the fracture site. The calluses consisted of GFP- and osteocalcin-positive cells at the same site, although the femur consisted of only osteocalcin-positive cells. We suggest that bone marrow cells migrated outside of the bone marrow and differentiated into osteoblasts to make up the calluses.

  3. A nonsense mutation in the DNA repair factor Hebo causes mild bone marrow failure and microcephaly.

    PubMed

    Zhang, Shu; Pondarre, Corinne; Pennarun, Gaelle; Labussiere-Wallet, Helene; Vera, Gabriella; France, Benoit; Chansel, Marie; Rouvet, Isabelle; Revy, Patrick; Lopez, Bernard; Soulier, Jean; Bertrand, Pascale; Callebaut, Isabelle; de Villartay, Jean-Pierre

    2016-05-30

    Inherited bone marrow failure syndromes are human conditions in which one or several cell lineages of the hemopoietic system are affected. They are present at birth or may develop progressively. They are sometimes accompanied by other developmental anomalies. Three main molecular causes have been recognized to result in bone marrow failure syndromes: (1) defects in the Fanconi anemia (FA)/BRCA DNA repair pathway, (2) defects in telomere maintenance, and (3) abnormal ribosome biogenesis. We analyzed a patient with mild bone marrow failure and microcephaly who did not present with the typical FA phenotype. Cells from this patient showed increased sensitivity to ionizing radiations and phleomycin, attesting to a probable DNA double strand break (dsb) repair defect. Linkage analysis and whole exome sequencing revealed a homozygous nonsense mutation in the ERCC6L2 gene. We identified a new ERCC6L2 alternative transcript encoding the DNA repair factor Hebo, which is critical for complementation of the patient's DNAdsb repair defect. Sequence analysis revealed three structured regions within Hebo: a TUDOR domain, an adenosine triphosphatase domain, and a new domain, HEBO, specifically present in Hebo direct orthologues. Hebo is ubiquitously expressed, localized in the nucleus, and rapidly recruited to DNAdsb's in an NBS1-dependent manner.

  4. Angiogenic activity mediates bone repair from human pluripotent stem cell-derived osteogenic cells

    PubMed Central

    Zou, Li; Chen, Qingshan; Quanbeck, Zachary; Bechtold, Joan E.; Kaufman, Dan S.

    2016-01-01

    Human pluripotent stem cells provide a standardized resource for bone repair. However, criteria to determine which exogenous cells best heal orthopedic injuries remain poorly defined. We evaluated osteogenic progenitor cells derived from both human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs). Phenotypic and genotypic analyses demonstrated that these hESCs/hiPSCs are similar in their osteogenic differentiation efficiency and they generate osteogenic cells comparable to osteogenic cells derived from mesenchymal stromal cells (BM-MSCs). However, expression of angiogenic factors, such as vascular endothelial growth factor and basic fibroblast growth factor in these osteogenic progenitor cells are markedly different, suggesting distinct pro-angiogenic potential of these stem cell derivatives. Studies to repair a femur non-union fracture demonstrate only osteogenic progenitor cells with higher pro-angiogenic potential significantly enhance bone repair in vivo. Together, these studies highlight a key role of pro-angiogenic potential of transplanted osteogenic cells for effective cell-mediated bone repair. PMID:26980556

  5. A Novel Single Pulsed Electromagnetic Field Stimulates Osteogenesis of Bone Marrow Mesenchymal Stem Cells and Bone Repair

    PubMed Central

    Chang, Je-Ken; Chen, Chung-Hwan; Tai, I-Chun; Wang, Gwo-Jaw; Ho, Mei-Ling

    2014-01-01

    Pulsed electromagnetic field (PEMF) has been successfully applied to accelerate fracture repair since 1979. Recent studies suggest that PEMF might be used as a nonoperative treatment for the early stages of osteonecrosis. However, PEMF treatment requires a minimum of ten hours per day for the duration of the treatment. In this study, we modified the protocol of the single-pulsed electromagnetic field (SPEMF) that only requires a 3-minute daily treatment. In the in vitro study, cell proliferation and osteogenic differentiation was evaluated in the hBMSCs. In the in vivo study, new bone formation and revascularization were evaluated in the necrotic bone graft. Results from the in vitro study showed no significant cytotoxic effects on the hBMSCs after 5 days of SPEMF treatment (1 Tesla, 30 pulses per day). hBMSC proliferation was enhanced in the SPEMF-treated groups after 2 and 4 days of treatment. The osteogenic differentiation of hBMSCs was significantly increased in the SPEMF-treated groups after 3–7 days of treatment. Mineralization also increased after 10, 15, 20, and 25 days of treatment in SPEMF-treated groups compared to the control group. The 7-day short-course treatment achieved similar effects on proliferation and osteogenesis as the 25-day treatment. Results from the in vivo study also demonstrated that both the 7-day and 25-day treatments of SPEMF increased callus formation around the necrotic bone and also increased new vessel formation and osteocyte numbers in the grafted necrotic bone at the 2nd and 4th weeks after surgery. In conclusion, the newly developed SPEMF accelerates osteogenic differentiation of cultured hBMSCs and enhances bone repair, neo-vascularization, and cell growth in necrotic bone in mice. The potential clinical advantage of the SPEMF is the short daily application and the shorter treatment course. We suggest that SPEMF may be used to treat fractures and the early stages of osteonecrosis. PMID:24632682

  6. Bringing new life to damaged bone: the importance of angiogenesis in bone repair and regeneration.

    PubMed

    Stegen, Steve; van Gastel, Nick; Carmeliet, Geert

    2015-01-01

    Bone has the unique capacity to heal without the formation of a fibrous scar, likely because several of the cellular and molecular processes governing bone healing recapitulate the events during skeletal development. A critical component in bone healing is the timely appearance of blood vessels in the fracture callus. Angiogenesis, the formation of new blood vessels from pre-existing ones, is stimulated after fracture by the local production of numerous angiogenic growth factors. The fracture vasculature not only supplies oxygen and nutrients, but also stem cells able to differentiate into osteoblasts and in a later phase also the ions necessary for mineralization. This review provides a concise report of the regulation of angiogenesis by bone cells, its importance during bone healing and its possible therapeutic applications in bone tissue engineering. This article is part of a Special Issue entitled "Stem Cells and Bone".

  7. Bringing new life to damaged bone: the importance of angiogenesis in bone repair and regeneration.

    PubMed

    Stegen, Steve; van Gastel, Nick; Carmeliet, Geert

    2015-01-01

    Bone has the unique capacity to heal without the formation of a fibrous scar, likely because several of the cellular and molecular processes governing bone healing recapitulate the events during skeletal development. A critical component in bone healing is the timely appearance of blood vessels in the fracture callus. Angiogenesis, the formation of new blood vessels from pre-existing ones, is stimulated after fracture by the local production of numerous angiogenic growth factors. The fracture vasculature not only supplies oxygen and nutrients, but also stem cells able to differentiate into osteoblasts and in a later phase also the ions necessary for mineralization. This review provides a concise report of the regulation of angiogenesis by bone cells, its importance during bone healing and its possible therapeutic applications in bone tissue engineering. This article is part of a Special Issue entitled "Stem Cells and Bone". PMID:25263520

  8. Bone repair following bone grafting hydroxyapatite guided bone regeneration and infra-red laser photobiomodulation: a histological study in a rodent model.

    PubMed

    Pinheiro, Antonio Luiz B; Martinez Gerbi, Marleny E; de Assis Limeira, Francisco; Carneiro Ponzi, Elizabeth Arruda; Marques, Aparecida M C; Carvalho, Carolina Montagn; de Carneiro Santos, Rafael; Oliveira, Priscila Chagas; Nóia, Manuela; Ramalho, Luciana Maria Pedreira

    2009-03-01

    The aim of the investigation was to assess histologically the effect of laser photobiomodulation (LPBM) on a repair of defects surgically created in the femurs of rats. Forty-five Wistar rats were divided into four groups: group I (control); group II (LPBM); group III (hydroxyapatite guided bone regeneration; HA GBR); group IV (HA GBR LPBM). The animals in the irradiated groups were subjected to the first irradiation immediately after surgery, and it was repeated every day for 2 weeks. The animals were killed 15 days, 21 days and 30 days after surgery. When the groups irradiated with implant and membrane were compared, it was observed that the repair of the defects submitted to LPBM was also processed faster, starting from the 15th day. At the 30th day, the level of repair of the defects was similar in the irradiated groups and those not irradiated. New bone formation was seen inside the cavity, probably by the osteoconduction of the implant, and, in the irradiated groups, this new bone formation was incremental. The present preliminary data seem to suggest that LPMB therapy might have a positive effect upon early wound healing of bone defects treated with a combination of HA and GBR.

  9. Composite scaffolds of mesoporous bioactive glass and polyamide for bone repair

    PubMed Central

    Su, Jiacan; Cao, Liehu; Yu, Baoqing; Song, Shaojun; Liu, Xinwei; Wang, Zhiwei; Li, Ming

    2012-01-01

    A bone-implanted porous scaffold of mesoporous bioglass/polyamide composite (m-BPC) was fabricated, and its biological properties were investigated. The results indicate that the m-BPC scaffold contained open and interconnected macropores ranging 400–500 μm, and exhibited a porosity of 76%. The attachment ratio of MG-63 cells on m-BPC was higher than polyamide scaffolds at 4 hours, and the cells with normal phenotype extended well when cultured with m-BPC and polyamide scaffolds. When the m-BPC scaffolds were implanted into bone defects of rabbit thighbone, histological evaluation confirmed that the m-BPC scaffolds exhibited excellent biocompatibility and osteoconductivity, and more effective osteogenesis than the polyamide scaffolds in vivo. The results indicate that the m-BPC scaffolds improved the efficiency of new bone regeneration and, thus, have clinical potential for bone repair. PMID:22679367

  10. Composite scaffolds of mesoporous bioactive glass and polyamide for bone repair.

    PubMed

    Su, Jiacan; Cao, Liehu; Yu, Baoqing; Song, Shaojun; Liu, Xinwei; Wang, Zhiwei; Li, Ming

    2012-01-01

    A bone-implanted porous scaffold of mesoporous bioglass/polyamide composite (m-BPC) was fabricated, and its biological properties were investigated. The results indicate that the m-BPC scaffold contained open and interconnected macropores ranging 400-500 μm, and exhibited a porosity of 76%. The attachment ratio of MG-63 cells on m-BPC was higher than polyamide scaffolds at 4 hours, and the cells with normal phenotype extended well when cultured with m-BPC and polyamide scaffolds. When the m-BPC scaffolds were implanted into bone defects of rabbit thighbone, histological evaluation confirmed that the m-BPC scaffolds exhibited excellent biocompatibility and osteoconductivity, and more effective osteogenesis than the polyamide scaffolds in vivo. The results indicate that the m-BPC scaffolds improved the efficiency of new bone regeneration and, thus, have clinical potential for bone repair. PMID:22679367

  11. The role of graft materials in suture augmentation for tendon repairs and reattachment.

    PubMed

    Kummer, Frederick J; Iesaka, Kazuho

    2005-08-01

    Various biomaterials have been used to augment sutures for the repair and reattachment of tendons. This study examined four different graft materials in a simple and reproducible model using chicken Achilles tendons to determine the strength and mechanism of suture reinforcement of tendon repairs. The graft materials tested were Gore-Tex(R) Soft Tissue Patch, Graftjacket, bovine pericardium, and an experimental graft material from Xylos Corporation. Testing was performed in shear to simulate forces on a torn tendon repair and pull-off to simulate those on a tendon reattachment to bone. Compared to unaugmented suture, grafts increased suture fixation strength from 10% to 60% in shear and from 0% to 36% in pull-off with the bovine pericardium graft, providing significant improvement in both tests. In no cases (even unaugmented) did the suture pull directly through the tendon, but instead sliced along it, demonstrating that the interface between the suture and the tendon determines fixation strength. Grafts function by increasing the area, friction, and nature of this interface, not by acting as a barrier for suture pull-through. PMID:15981174

  12. Mechanical properties of bioactive glass (13-93) scaffolds fabricated by robotic deposition for structural bone repair.

    PubMed

    Liu, Xin; Rahaman, Mohamed N; Hilmas, Gregory E; Bal, B Sonny

    2013-06-01

    There is a need to develop synthetic scaffolds to repair large defects in load-bearing bones. Bioactive glasses have attractive properties as a scaffold material for bone repair, but data on their mechanical properties are limited. The objective of the present study was to comprehensively evaluate the mechanical properties of strong porous scaffolds of silicate 13-93 bioactive glass fabricated by robocasting. As-fabricated scaffolds with a grid-like microstructure (porosity 47%, filament diameter 330μm, pore width 300μm) were tested in compressive and flexural loading to determine their strength, elastic modulus, Weibull modulus, fatigue resistance, and fracture toughness. Scaffolds were also tested in compression after they were immersed in simulated body fluid (SBF) in vitro or implanted in a rat subcutaneous model in vivo. As fabricated, the scaffolds had a strength of 86±9MPa, elastic modulus of 13±2GPa, and a Weibull modulus of 12 when tested in compression. In flexural loading the strength, elastic modulus, and Weibull modulus were 11±3MPa, 13±2GPa, and 6, respectively. In compression, the as-fabricated scaffolds had a mean fatigue life of ∼10(6) cycles when tested in air at room temperature or in phosphate-buffered saline at 37°C under cyclic stresses of 1-10 or 2-20MPa. The compressive strength of the scaffolds decreased markedly during the first 2weeks of immersion in SBF or implantation in vivo, but more slowly thereafter. The brittle mechanical response of the scaffolds in vitro changed to an elasto-plastic response after implantation for longer than 2-4weeks in vivo. In addition to providing critically needed data for designing bioactive glass scaffolds, the results are promising for the application of these strong porous scaffolds in loaded bone repair.

  13. Mechanical properties of bioactive glass (13-93) scaffolds fabricated by robotic deposition for structural bone repair

    PubMed Central

    Liu, Xin; Rahaman, Mohamed N.; Hilmas, Gregory E.; Bal, B. Sonny

    2013-01-01

    There is a need to develop synthetic scaffolds for repairing large defects in load-bearing bones. Bioactive glasses have attractive properties as a scaffold material for bone repair, but data on their mechanical properties are limited. The objective of the present study was to comprehensively evaluate the mechanical properties of strong porous scaffolds of silicate 13-93 bioactive glass fabricated by robocasting. As-fabricated scaffolds with a grid-like microstructure (porosity = 47%; filament diameter = 330 μm; pore width = 300) were tested in compressive and flexural loading to determine their strength, elastic modulus, Weibull modulus, fatigue resistance, and fracture toughness. Scaffolds were also tested in compression after they were immersed in simulated body fluid (SBF) in vitro or implanted in a rat subcutaneous model in vivo. As fabricated, the scaffolds had a strength = 86 ± 9 MPa, elastic modulus = 13 ± 2 GPa, and a Weibull modulus = 12 when tested in compression. In flexural loading, the strength, elastic modulus, and Weibull modulus were 11 ± 3 MPa, 13 ± 2 GPa, and 6, respectively. In compression, the as-fabricated scaffolds had a mean fatigue life of ~106 cycles when tested in air at room temperature or in phosphate-buffered saline at 37 °C under cyclic stresses of 1–10 MPa or 2–20 MPa. The compressive strength of the scaffolds decreased markedly during the first 2 weeks of immersion in SBF or implantation in vivo, but more slowly thereafter. The brittle mechanical response of the scaffolds in vitro changed to an elasto-plastic response after implantation for longer than 2–4 weeks in vivo. In addition to providing critically needed data for designing bioactive glass scaffolds, the results are promising for the application of these strong porous scaffolds in loaded bone repair. PMID:23438862

  14. In situ strategy for bone repair by facilitated endogenous tissue engineering.

    PubMed

    Chen, Jingdi; Zhang, Yujue; Pan, Panpan; Fan, Tiantang; Chen, Mingmao; Zhang, Qiqing

    2015-11-01

    Traditional tissue engineering procedures are expensive and time consuming. Facilitated endogenous tissue engineering (FETE) provides a solution that can avoid the ex vivo culture of autologous cells and initiate in situ reparative endogenous repair processes in vivo. This method involves fabricating a porous scaffold that mimics the environment present during the bone formation process, consisting of components that provide biomimetic interfacial interactions to cells. After the scaffold is implanted, progenitor cells provided by autologous bone marrow and surrounding tissues then differentiate to bone cells under the direction of the in situ scaffold. This paper reports a biomimetic method to prepare a hierarchically structured hybrid scaffold. Bone-like nano hydroxyapatite (HA) was crystallized from a collagen and chitosan (CC) matrix to form a porous scaffold. The in vivo study demonstrates that this nanohybrid scaffold supports excellent bone repair. This means that the FETE approach, in which the cell culture portion of traditional tissue engineering takes place in vivo, can promote the intrinsic regenerative potential of endogenous tissues.

  15. Effect on the contour of bone and soft tissue one year after harvesting chin bone for alveolar cleft repair.

    PubMed

    Dik, E A; de Ruiter, A P; van der Bilt, A; Koole, R

    2010-10-01

    In this study the authors evaluate and quantify the residual bony defect in the mandibular symphysis and its effect on the soft tissue contour a minimum of 1 year after harvesting chin bone. 59 ASA I cleft lip and palate patients, aged 8-19 years were included. In all patients an autologous bone graft from the mandibular symphysis was harvested for transplantation to the alveolar cleft. Lateral cephalograms were used to measure the donor site defects, and the effects on the soft tissue contour. An evident residual defect was measured at the donor site 1 year after harvesting chin bone. A significant relation was seen between age at time of surgery and size of the defect 1 year postoperatively. In older patients a larger defect remained. Using the current surgical technique of harvesting chin bone, complete bony repair of the defect was not achieved. This study shows postoperatively persisting defects that comprise on average 14% of the original peroperative defects. A significant increase in soft tissue thickness was seen at the mandibular symphysis at a minimum of 1 year postoperatively. These changes in the soft tissue chin contour 1 year after harvesting bone are similar to normal growth changes.

  16. Advancement of the Subchondral Bone Plate in Translational Models of Osteochondral Repair: Implications for Tissue Engineering Approaches.

    PubMed

    Orth, Patrick; Madry, Henning

    2015-12-01

    Subchondral bone plate advancement is of increasing relevance for translational models of osteochondral repair in tissue engineering (TE). Especially for therapeutic TE approaches, a basic scientific knowledge of its chronological sequence, possible etiopathogenesis, and clinical implications are indispensable. This review summarizes the knowledge on this topic gained from a total of 31 translational investigations, including 1009 small and large animals. Experimental data indicate that the advancement of the subchondral bone plate frequently occurs during the spontaneous repair of osteochondral defects and following established articular cartilage repair approaches for chondral lesions such as marrow stimulation and TE-based strategies such as autologous chondrocyte implantation. Importantly, this subchondral bone reaction proceeds in a defined chronological and spatial pattern, reflecting both endochondral ossification and intramembranous bone formation. Subchondral bone plate advancement arises earlier in small animals and defects, but is more pronounced at the long term in large animals. Possible etiopathologies comprise a disturbed subchondral bone/articular cartilage crosstalk and altered biomechanical conditions or neovascularization. Of note, no significant correlation was found so far between subchondral bone plate advancement and articular cartilage repair. This evidence from translational animal models adverts to an increasing awareness of this previously underestimated pathology. Future research will shed more light on the advancement of the subchondral bone plate in TE models of cartilage repair. PMID:26066580

  17. Advancement of the Subchondral Bone Plate in Translational Models of Osteochondral Repair: Implications for Tissue Engineering Approaches.

    PubMed

    Orth, Patrick; Madry, Henning

    2015-12-01

    Subchondral bone plate advancement is of increasing relevance for translational models of osteochondral repair in tissue engineering (TE). Especially for therapeutic TE approaches, a basic scientific knowledge of its chronological sequence, possible etiopathogenesis, and clinical implications are indispensable. This review summarizes the knowledge on this topic gained from a total of 31 translational investigations, including 1009 small and large animals. Experimental data indicate that the advancement of the subchondral bone plate frequently occurs during the spontaneous repair of osteochondral defects and following established articular cartilage repair approaches for chondral lesions such as marrow stimulation and TE-based strategies such as autologous chondrocyte implantation. Importantly, this subchondral bone reaction proceeds in a defined chronological and spatial pattern, reflecting both endochondral ossification and intramembranous bone formation. Subchondral bone plate advancement arises earlier in small animals and defects, but is more pronounced at the long term in large animals. Possible etiopathologies comprise a disturbed subchondral bone/articular cartilage crosstalk and altered biomechanical conditions or neovascularization. Of note, no significant correlation was found so far between subchondral bone plate advancement and articular cartilage repair. This evidence from translational animal models adverts to an increasing awareness of this previously underestimated pathology. Future research will shed more light on the advancement of the subchondral bone plate in TE models of cartilage repair.

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

    PubMed Central

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

    2016-01-01

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

  19. Angiogenic and Osteogenic Potential of Bone Repair Cells for Craniofacial Regeneration

    PubMed Central

    Pagni, Giorgio; Park, Chan-Ho; Tarle, Susan A.; Bartel, Ronnda L.; Giannobile, William V.

    2010-01-01

    There has been increased interest in the therapeutic potential of bone marrow derived cells for tissue engineering applications. Bone repair cells (BRCs) represent a unique cell population generated via an ex vivo, closed-system, automated cell expansion process, to drive the propagation of highly osteogenic and angiogenic cells for bone engineering applications. The aims of this study were (1) to evaluate the in vitro osteogenic and angiogenic potential of BRCs, and (2) to evaluate the bone and vascular regenerative potential of BRCs in a craniofacial clinical application. BRCs were produced from bone marrow aspirates and their phenotypes and multipotent potential characterized. Flow cytometry demonstrated that BRCs were enriched for mesenchymal and vascular phenotypes. Alkaline phosphatase and von Kossa staining were performed to assess osteogenic differentiation, and reverse transcriptase–polymerase chain reaction was used to determine the expression levels of bone specific factors. Angiogenic differentiation was determined through in vitro formation of tube-like structures and fluorescent labeling of endothelial cells. Finally, 6 weeks after BRC transplantation into a human jawbone defect, a biopsy of the regenerated site revealed highly vascularized, mineralized bone tissue formation. Taken together, these data provide evidence for the multilineage and clinical potential of BRCs for craniofacial regeneration. PMID:20412009

  20. Epidemiology and imaging of the subchondral bone in articular cartilage repair.

    PubMed

    Menetrey, Jacques; Unno-Veith, Florence; Madry, Henning; Van Breuseghem, Iwan

    2010-04-01

    Articular cartilage and the subchondral bone act as a functional unit. Following trauma, osteochondritis dissecans, osteonecrosis or osteoarthritis, this intimate connection may become disrupted. Osteochondral defects-the type of defects that extend into the subchondral bone-account for about 5% of all articular cartilage lesions. They are very often caused by trauma, in about one-third of the cases by osteoarthritis and rarely by osteochondritis dissecans. Osteochondral defects are predominantly located on the medial femoral condyle and also on the patella. Frequently, they are associated with lesions of the menisci or the anterior cruciate ligament. Because of the close relationship between the articular cartilage and the subchondral bone, imaging of cartilage defects or cartilage repair should also focus on the subchondral bone. Magnetic resonance imaging is currently considered to be the key modality for the evaluation of cartilage and underlying subchondral bone. However, the choice of imaging technique also depends on the nature of the disease that caused the subchondral bone lesion. For example, radiography is still the golden standard for imaging features of osteoarthritis. Bone scintigraphy is one of the most valuable techniques for early diagnosis of spontaneous osteonecrosis about the knee. A CT scan is a useful technique to rule out a possible depression of the subchondral bone plate, whereas a CT arthrography is highly accurate to evaluate the stability of the osteochondral fragment in osteochondritis dissecans. Particularly for the problem of subchondral bone lesions, image evaluation methods need to be refined for adequate and reproducible analysis. This article highlights recent studies on the epidemiology and imaging of the subchondral bone, with an emphasis on magnetic resonance imaging.

  1. An Alginate-based Hybrid System for Growth Factor Delivery in the Functional Repair of Large Bone Defects

    PubMed Central

    Kolambkar, Yash M.; Dupont, Kenneth M.; Boerckel, Joel D.; Huebsch, Nathaniel; Mooney, David J.; Hutmacher, Dietmar W.

    2010-01-01

    The treatment of challenging fractures and large osseous defects presents a formidable problem for orthopaedic surgeons. Tissue engineering/regenerative medicine approaches seek to solve this problem by delivering osteogenic signals within scaffolding biomaterials. In this study, we introduce a hybrid growth factor delivery system that consists of an electrospun nanofiber mesh tube for guiding bone regeneration combined with peptide-modified alginate hydrogel injected inside the tube for sustained growth factor release. We tested the ability of this system to deliver recombinant bone morphogenetic protein-2 (rhBMP-2) for the repair of critically-sized segmental bone defects in a rat model. Longitudinal μ-CT analysis and torsional testing provided quantitative assessment of bone regeneration. Our results indicate that the hybrid delivery system resulted in consistent bony bridging of the challenging bone defects. However, in the absence of rhBMP-2, the use of nanofiber mesh tube and alginate did not result in substantial bone formation. Perforations in the nanofiber mesh accelerated the rhBMP-2 mediated bone repair, and resulted in functional restoration of the regenerated bone. μ-CT based angiography indicated that perforations did not significantly affect the revascularization of defects, suggesting that some other interaction with the tissue surrounding the defect such as improved infiltration of osteoprogenitor cells contributed to the observed differences in repair. Overall, our results indicate that the hybrid alginate/nanofiber mesh system is a promising growth factor delivery strategy for the repair of challenging bone injuries. PMID:20864165

  2. Effects of low-level laser therapy (LLLT) on bone repair in rats: optical densitometry analysis.

    PubMed

    Barbosa, Danillo; de Souza, Renato Aparecido; Xavier, Murilo; da Silva, Fabiano Fernandes; Arisawa, Emilia Angela Loschiavo; Villaverde, Antonio Guillermo Jose Balbin

    2013-02-01

    The aim of this study was to evaluate the process of bone repair in rats submitted to low-level laser therapy using optical densitometry. A total of 45 rats which underwent femoral osteotomy were randomly distributed into three groups: control (group I) and laser-treated groups using wavelengths in the red (λ, 660-690 nm) and in the infrared (λ, 790-830 nm) spectra (group II and group III, respectively). The animals (five per group) were killed after 7, 14, and 21 days and the femurs were removed for optical densitometry analysis. Optical density showed a significant increase in the degree of mineralization (gray level) in both groups treated with the laser after 7 days. After 14 days, only the group treated with laser therapy in the infrared spectrum showed higher bone density. No differences were observed between groups after 21 days. Such results suggest the positive effect of low-level laser therapy in bone repair is time- and wavelength-dependent. In addition, our results have confirmed that optical densitometry technique can measure bone mineralization status.

  3. A bispecific antibody targeting sclerostin and DKK-1 promotes bone mass accrual and fracture repair

    PubMed Central

    Florio, Monica; Gunasekaran, Kannan; Stolina, Marina; Li, Xiaodong; Liu, Ling; Tipton, Barbara; Salimi-Moosavi, Hossein; Asuncion, Franklin J.; Li, Chaoyang; Sun, Banghua; Tan, Hong Lin; Zhang, Li; Han, Chun-Ya; Case, Ryan; Duguay, Amy N.; Grisanti, Mario; Stevens, Jennitte; Pretorius, James K.; Pacheco, Efrain; Jones, Heidi; Chen, Qing; Soriano, Brian D.; Wen, Jie; Heron, Brenda; Jacobsen, Frederick W.; Brisan, Emil; Richards, William G.; Ke, Hua Zhu; Ominsky, Michael S.

    2016-01-01

    Inhibition of the Wnt antagonist sclerostin increases bone mass in patients with osteoporosis and in preclinical animal models. Here we show increased levels of the Wnt antagonist Dickkopf-1 (DKK-1) in animals treated with sclerostin antibody, suggesting a negative feedback mechanism that limits Wnt-driven bone formation. To test our hypothesis that co-inhibition of both factors further increases bone mass, we engineer a first-in-class bispecific antibody with single residue pair mutations in the Fab region to promote efficient and stable cognate light–heavy chain pairing. We demonstrate that dual inhibition of sclerostin and DKK-1 leads to synergistic bone formation in rodents and non-human primates. Furthermore, by targeting distinct facets of fracture healing, the bispecific antibody shows superior bone repair activity compared with monotherapies. This work supports the potential of this agent both for treatment and prevention of fractures and offers a promising therapeutic approach to reduce the burden of low bone mass disorders. PMID:27230681

  4. A bispecific antibody targeting sclerostin and DKK-1 promotes bone mass accrual and fracture repair.

    PubMed

    Florio, Monica; Gunasekaran, Kannan; Stolina, Marina; Li, Xiaodong; Liu, Ling; Tipton, Barbara; Salimi-Moosavi, Hossein; Asuncion, Franklin J; Li, Chaoyang; Sun, Banghua; Tan, Hong Lin; Zhang, Li; Han, Chun-Ya; Case, Ryan; Duguay, Amy N; Grisanti, Mario; Stevens, Jennitte; Pretorius, James K; Pacheco, Efrain; Jones, Heidi; Chen, Qing; Soriano, Brian D; Wen, Jie; Heron, Brenda; Jacobsen, Frederick W; Brisan, Emil; Richards, William G; Ke, Hua Zhu; Ominsky, Michael S

    2016-01-01

    Inhibition of the Wnt antagonist sclerostin increases bone mass in patients with osteoporosis and in preclinical animal models. Here we show increased levels of the Wnt antagonist Dickkopf-1 (DKK-1) in animals treated with sclerostin antibody, suggesting a negative feedback mechanism that limits Wnt-driven bone formation. To test our hypothesis that co-inhibition of both factors further increases bone mass, we engineer a first-in-class bispecific antibody with single residue pair mutations in the Fab region to promote efficient and stable cognate light-heavy chain pairing. We demonstrate that dual inhibition of sclerostin and DKK-1 leads to synergistic bone formation in rodents and non-human primates. Furthermore, by targeting distinct facets of fracture healing, the bispecific antibody shows superior bone repair activity compared with monotherapies. This work supports the potential of this agent both for treatment and prevention of fractures and offers a promising therapeutic approach to reduce the burden of low bone mass disorders. PMID:27230681

  5. Hybrid composites of calcium phosphate granules, fibrin glue, and bone marrow for skeletal repair.

    PubMed

    Le Nihouannen, Damien; Goyenvalle, Eric; Aguado, Eric; Pilet, Paul; Bilban, Melitta; Daculsi, Guy; Layrolle, Pierre

    2007-05-01

    Synthetic bone substitutes, such as calcium phosphate ceramics, give good results in clinical applications. In order to adapt to surgical sites, bioceramics come in the form of blocks or granules, and are either dense or porous. Combining these bioceramics with fibrin glue provides a mouldable and self-hardening composite biomaterial with the biochemical properties of each component. Critical-sized defects in the femoral condyle of rabbits were filled with TricOs/fibrin glue/bone marrow hybrid/composite material. The TricOs granules (1-2 mm) were composed of hydroxyapatite and beta tricalcium phosphate (60/40 in weight). The fibrin glue was composed of fibrinogen, thrombin and other biological factors and mixed with MBCP granules either simultaneously or sequentially. Bone marrow was also added to the MBCP/fibrin composite prior to filling the defects. After 3, 6, 12, and 24 weeks of implantation, the newly-formed bone was analysed with histology, histomorphometry and mechanical tests. The newly-formed bone had grown centripetally. Simultaneous application of fibrin glue showed better results for mechanical properties than sequential application after 6 weeks. Around 40% of bone had formed after 24 weeks in the three groups. Although the addition of bone marrow did not improve bone formation, the MBCP/fibrin material could be used in clinical bone filling applications. PMID:17117470

  6. Repair of segmental bone defects with bone marrow and BMP-2 adenovirus in the rabbit radius

    NASA Astrophysics Data System (ADS)

    Cheng, Lijia; Lu, Xiaofeng; Shi, Yujun; Li, Li; Xue, Jing; Zhang, Li; Xia, Jie; Wang, Yujia; Zhang, Xingdong; Bu, Hong

    2012-12-01

    Bone tissue engineering (BTE) is approached via implantation of autogenous mesenchymal stem cells (MSCs), marrow cells, or platelet-rich plasma, etc. To the contrary, gene therapy combining with the bone marrow (BM) has not been often reported. This study was performed to investigate whether a modified BTE method, that is, the BM and a recombinant human bone morphogenetic protein-2 adenovirus (Ad.hBMP-2) gene administering in hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ceramics could accelerate the healing of segmental defects in the rabbit radius. In our study, ceramics were immersed in the adenovirus overnight, and half an hour before surgery, autologous BM aspirates were thoroughly mixed with the ceramics; at the same time, a 15-mm radius defect was introduced in the bilateral forelimbs of all animals, after that, this defect was filled with the following: (1) Ad.hBMP-2 + HA/β-TCP + autologous BM (group 1); (2) HA/β-TCP + Ad.hBMP-2 (group 2); (3) HA/β-TCP alone (group 3); (4) an empty defect as a control (group 4). Histological observation and μ-CT analyses were performed on the specimens at weeks 2, 4, 8, and 12, respectively. In group 1, new bone was observed at week 4 and BM appeared at week 12, in groups 2 and 3, new bone was observed at week 8 and it was more mature at week 12, in contrast, the defect was not bridged in group 4 at week 12. The new bone area percentage in group 1 was significantly higher than that in groups 2 and 3. Our study indicated that BM combined with hBMP-2 adenovirus and porous ceramics could significantly increase the amount of newly formed bone. And this modified BTE method thus might have potentials in future clinical application.

  7. Use of frozen cranial vault bone allografts in the repair of extensive cranial bone defects.

    PubMed

    Vanaclocha, V; Bazan, A; Saiz-Sapena, N; Paloma, V; Idoate, M

    1997-01-01

    In cranioplasty complexity is proportional to the size of the detect, particularly if greater than 50 cm2. If the patient's own bone flap is not available, allogenic frozen bone graft can be used instead. Between June 1990 and June 1995 twenty cranioplasties with allogenic frozen bone grafts were performed. Age of patients ranged between 23 and 63 years (average 38.4 years). Male/female ratio was 2:1.7. Size of craniectomy ranged between 65 and 150 cm2 (average 83.3 cm2). Follow-up ranged between 10 and 58 months (average 41 months). Donors were tested to rule out transmissible diseases, infections, sepsis and/or cancer. Bone grafts were removed under aseptic conditions, microbiological cultures were taken, wrapped in a gauze soaked with Gentamicin sulphate and Bacitracin, sealed in three sterilised vinyl plastic bags, and stored in a deep freezer for a minimum of 30 days (range 36-93 days, average 67 days), at a temperature of -80 degrees C. Grafts were placed in the defect after a step was carved on its borders to facilitate the contact between host and graft. Vancomycin 1 g. IV/12 hours and Ceftriaxone 1 g. IV/12 hours were administered for five days. Grafts were covered by means of scalp flaps. Only one required a musculocutaneous free flap. None was exposed, extruded or had to be removed. Plain skull X-ray studies showed progressive remodelling of the grafts. Partial resorption was observed in two (2/20, 10%) and loss of thickness in another 3/20 (15%), but with no changes in the contour. Biopsies were taken in 3/20 (15%) cases at a second surgical procedure. Areas of osteoclastic resorptive activity mixed with others of osteoblastic bone apposition, showed replacement with new bone. We conclude that cranial vault frozen allografts are a good alternative to autologous bone when the latter is absent or not present in sufficient amount. PMID:9265959

  8. Epigenetically Modified Bone Marrow Stromal Cells in Silk Scaffolds Promote Craniofacial Bone Repair and Wound Healing.

    PubMed

    Han, Qianqian; Yang, Pishan; Wu, Yuwei; Meng, Shu; Sui, Lei; Zhang, Lan; Yu, Liming; Tang, Yin; Jiang, Hua; Xuan, Dongying; Kaplan, David L; Kim, Sung Hoon; Tu, Qisheng; Chen, Jake

    2015-08-01

    Epigenetic regulation of gene expression is a central mechanism that governs cell stemness, determination, commitment, and differentiation. It has been recently found that PHF8, a major H4K20/H3K9 demethylase, plays a critical role in craniofacial and bone development. In this study, we hypothesize that PHF8 promotes osteoblastogenesis by epigenetically regulating the expression of a nuclear matrix protein, special AT-rich sequence-binding protein 2 (SATB2) that plays pivotal roles in skeletal patterning and osteoblast differentiation. Our results showed that expression levels of PHF8 and SATB2 in preosteoblasts and bone marrow stromal cells (BMSCs) increased simultaneously during osteogenic induction. Overexpressing PHF8 in these cells upregulated the expression of SATB2, Runx2, osterix, and bone matrix proteins. Conversely, knockdown of PHF8 reduced the expression of these genes. Furthermore, ChIP assays confirmed that PHF8 specifically bound to the transcription start site (TSS) of the SATB2 promoter, and the expression of H3K9me1 at the TSS region of SATB2 decreased in PHF8 overexpressed group. Implantation of the BMSCs overexpressing PHF8 with silk protein scaffolds promoted bone regeneration in critical-sized defects in mouse calvaria. Taken together, our results demonstrated that PHF8 epigenetically modulates SATB2 activity, triggering BMSCs osteogenic differentiation and facilitating bone formation and regeneration in biodegradable silk scaffolds.

  9. Ricinus communis-based biopolymer and epidermal growth factor regulations on bone defect repair: A rat tibia model

    NASA Astrophysics Data System (ADS)

    Mendoza-Barrera, C.; Meléndez-Lira, M.; Altuzar, V.; Tomás, S. A.

    2003-01-01

    We report the effect of the addition of an epidermal growth factor to a Ricinus communis-based biopolymer in the healing of a rat tibia model. Bone repair and osteointegration after a period of three weeks were evaluated employing photoacoustic spectroscopy and x-ray diffraction. A parallel study was performed at 1, 2, 3, 4, 5, 6, 7, and 8 weeks with energy dispersive x-ray spectroscopy. We conclude that the use of an epidermal growth factor (group EGF) in vivo accelerates the process of bony repair in comparison with other groups, and that the employment of the Ricinus communis-based biopolymer as a bone substitute decreases bone production.

  10. Bone grafting: history, rationale, and selection of materials and techniques.

    PubMed

    Horowitz, Robert A; Leventis, Minas D; Rohrer, Michael D; Prasad, Hari S

    2014-01-01

    In the 100-year history of bone replacement in the human body for different purposes, a wide variety of surgical approaches and materials have been used. The techniques and materials selected significantly affect the outcome of bone replacement procedures in terms of bone formation volume and the quality and amount of vital bone. The choices facing the dental surgeon at the time of extraction, ridge augmentation, or sinus graft are wide-ranging. When choosing a bone graft material the surgeon should consider its ultimate effect on healing patterns in and around the alveolar bone at the endpoint of the procedure. As this article concludes, a better understanding of the materials and the results that can be predictably achieved with them can be valuable to the appropriately trained surgeon when preparing for these procedures. PMID:25455148

  11. Silk-Hydroxyapatite Nanoscale Scaffolds with Programmable Growth Factor Delivery for Bone Repair.

    PubMed

    Ding, Zhaozhao; Fan, Zhihai; Huang, Xiaowei; Lu, Qiang; Xu, Weian; Kaplan, David L

    2016-09-21

    Osteoinductive biomaterials are attractive for repairing a variety of bone defects, and biomimetic strategies are useful toward developing bone scaffolds with such capacity. Here, a multiple biomimetic design was developed to improve the osteogenesis capacity of composite scaffolds consisting of hydroxyapatite nanoparticles (HA) and silk fibroin (SF). SF nanofibers and water-dispersible HA nanoparticles were blended to prepare the nanoscaled composite scaffolds with a uniform distribution of HA with a high HA content (40%), imitating the extracellular matrix (ECM) of bone. Bone morphogenetic protein-2 (BMP-2) was loaded in the SF scaffolds and HA to tune BMP-2 release. In vitro studies showed the preservation of BMP-2 bioactivity in the composite scaffolds, and programmable sustained release was achieved through adjusting the ratio of BMP-2 loaded on SF and HA. In vitro and in vivo osteogenesis studies demonstrated that the composite scaffolds showed improved osteogenesis capacity under suitable BMP-2 release conditions, significantly better than that of BMP-2 loaded SF-HA composite scaffolds reported previously. Therefore, these biomimetic SF-HA nanoscaled scaffolds with tunable BMP-2 delivery provide preferable microenvironments for bone regeneration. PMID:27579921

  12. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone grafting material. 872.3930 Section 872.3930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3930 Bone grafting material. (a)...

  13. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone grafting material. 872.3930 Section 872.3930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3930 Bone grafting material. (a)...

  14. Multipotent adult progenitor cells on an allograft scaffold facilitate the bone repair process

    PubMed Central

    LoGuidice, Amanda; Houlihan, Alison; Deans, Robert

    2016-01-01

    Multipotent adult progenitor cells are a recently described population of stem cells derived from the bone marrow stroma. Research has demonstrated the potential of multipotent adult progenitor cells for treating ischemic injury and cardiovascular repair; however, understanding of multipotent adult progenitor cells in orthopedic applications remains limited. In this study, we evaluate the osteogenic and angiogenic capacity of multipotent adult progenitor cells, both in vitro and loaded onto demineralized bone matrix in vivo, with comparison to mesenchymal stem cells, as the current standard. When compared to mesenchymal stem cells, multipotent adult progenitor cells exhibited a more robust angiogenic protein release profile in vitro and developed more extensive vasculature within 2 weeks in vivo. The establishment of this vascular network is critical to the ossification process, as it allows nutrient exchange and provides an influx of osteoprogenitor cells to the wound site. In vitro assays confirmed the multipotency of multipotent adult progenitor cells along mesodermal lineages and demonstrated the enhanced expression of alkaline phosphatase and production of calcium-containing mineral deposits by multipotent adult progenitor cells, necessary precursors for osteogenesis. In combination with a demineralized bone matrix scaffold, multipotent adult progenitor cells demonstrated enhanced revascularization and new bone formation in vivo in an orthotopic defect model when compared to mesenchymal stem cells on demineralized bone matrix or demineralized bone matrix–only control groups. The potent combination of angiogenic and osteogenic properties provided by multipotent adult progenitor cells appears to create a synergistic amplification of the bone healing process. Our results indicate that multipotent adult progenitor cells have the potential to better promote tissue regeneration and healing and to be a functional cell source for use in orthopedic applications

  15. Multipotent adult progenitor cells on an allograft scaffold facilitate the bone repair process.

    PubMed

    LoGuidice, Amanda; Houlihan, Alison; Deans, Robert

    2016-01-01

    Multipotent adult progenitor cells are a recently described population of stem cells derived from the bone marrow stroma. Research has demonstrated the potential of multipotent adult progenitor cells for treating ischemic injury and cardiovascular repair; however, understanding of multipotent adult progenitor cells in orthopedic applications remains limited. In this study, we evaluate the osteogenic and angiogenic capacity of multipotent adult progenitor cells, both in vitro and loaded onto demineralized bone matrix in vivo, with comparison to mesenchymal stem cells, as the current standard. When compared to mesenchymal stem cells, multipotent adult progenitor cells exhibited a more robust angiogenic protein release profile in vitro and developed more extensive vasculature within 2 weeks in vivo. The establishment of this vascular network is critical to the ossification process, as it allows nutrient exchange and provides an influx of osteoprogenitor cells to the wound site. In vitro assays confirmed the multipotency of multipotent adult progenitor cells along mesodermal lineages and demonstrated the enhanced expression of alkaline phosphatase and production of calcium-containing mineral deposits by multipotent adult progenitor cells, necessary precursors for osteogenesis. In combination with a demineralized bone matrix scaffold, multipotent adult progenitor cells demonstrated enhanced revascularization and new bone formation in vivo in an orthotopic defect model when compared to mesenchymal stem cells on demineralized bone matrix or demineralized bone matrix-only control groups. The potent combination of angiogenic and osteogenic properties provided by multipotent adult progenitor cells appears to create a synergistic amplification of the bone healing process. Our results indicate that multipotent adult progenitor cells have the potential to better promote tissue regeneration and healing and to be a functional cell source for use in orthopedic applications. PMID

  16. In vitro simulation of pathological bone conditions to predict clinical outcome of bone tissue engineered materials

    NASA Astrophysics Data System (ADS)

    Nguyen, Duong Thuy Thi

    According to the Centers for Disease Control, the geriatric population of ≥65 years of age will increase to 51.5 million in 2020; 40% of white women and 13% of white men will be at risk for fragility fractures or fractures sustained under normal stress and loading conditions due to bone disease, leading to hospitalization and surgical treatment. Fracture management strategies can be divided into pharmaceutical therapy, surgical intervention, and tissue regeneration for fracture prevention, fracture stabilization, and fracture site regeneration, respectively. However, these strategies fail to accommodate the pathological nature of fragility fractures, leading to unwanted side effects, implant failures, and non-unions. Compromised innate bone healing reactions of patients with bone diseases are exacerbated with protective bone therapy. Once these patients sustain a fracture, bone healing is a challenge, especially when fracture stabilization is unsuccessful. Traditional stabilizing screw and plate systems were designed with emphasis on bone mechanics rather than biology. Bone grafts are often used with fixation devices to provide skeletal continuity at the fracture gap. Current bone grafts include autologous bone tissue and donor bone tissue; however, the quality and quantity demanded by fragility fractures sustained by high-risk geriatric patients and patients with bone diseases are not met. Consequently, bone tissue engineering strategies are advancing towards functionalized bone substitutes to provide fracture reconstruction while effectively mediating bone healing in normal and diseased fracture environments. In order to target fragility fractures, fracture management strategies should be tailored to allow bone regeneration and fracture stabilization with bioactive bone substitutes designed for the pathological environment. The clinical outcome of these materials must be predictable within various disease environments. Initial development of a targeted

  17. Development of a cyclosporin-A-induced immune tolerant rat model to test marrow allograft cell type effects on bone repair.

    PubMed

    Espitalier, Florent; Durand, Nicolas; Rémy, Séverine; Corre, Pierre; Sourice, Sophie; Pilet, Paul; Weiss, Pierre; Guicheux, Jérôme; Malard, Olivier

    2015-05-01

    Bone repair is an important concept in tissue engineering, and the ability to repair bone in hypotrophic conditions such as that of irradiated bone, represents a challenge for this field. Previous studies have shown that a combination of bone marrow and (BCP) was effective to repair irradiated bone. However, the origin and role played by each cell type in bone healing still remains unclear. In order to track the grafted cells, the development of an animal model that is immunotolerant to an allograft of bone marrow would be useful. Furthermore, because the immune system interacts with bone turnover, it is of critical importance to demonstrate that immunosuppressive drugs do not interfere with bone repair. After a preliminary study of immunotolerance, cyclosporin-A was chosen to be used in immunosuppressive therapy. Ten rats were included to observe qualitative and quantitative bone repair 8 days and 6 weeks after the creation of bone defects. The defects were filled with an allograft of bone marrow alone or in association with BCP under immunosuppressive treatment (cyclosporin-A). The results showed that there was no significant interaction of cyclosporin-A with osseous regeneration. The use of this new immunotolerant rat model of bone marrow allograft in future studies will provide insight on how the cells within the bone marrow graft contribute to bone healing, especially in irradiated conditions.

  18. Decalcified allograft in repair of lytic lesions of bone: A study to evolve bone bank in developing countries

    PubMed Central

    Gupta, Anil Kumar; Keshav, Kumar; Kumar, Praganesh

    2016-01-01

    Background: The quest for ideal bone graft substitutes still haunts orthopedic researchers. The impetus for this search of newer bone substitutes is provided by mismatch between the demand and supply of autogenous bone grafts. Bone banking facilities such as deep frozen and freeze-dried allografts are not so widely available in most of the developing countries. To overcome the problem, we have used partially decalcified, ethanol preserved, and domestic refrigerator stored allografts which are economical and needs simple technology for procurement, preparation, and preservation. The aim of the study was to assess the radiological and functional outcome of the partially decalcified allograft (by weak hydrochloric acid) in patients of benign lytic lesions of bone. Through this study, we have also tried to evolve, establish, and disseminate the concept of the bone bank. Materials and Methods: 42 cases of lytic lesions of bone who were treated by decalcified (by weak hydrochloric acid), ethanol preserved, allografts were included in this prospective study. The allograft was obtained from freshly amputated limbs or excised femoral heads during hip arthroplasties under strict aseptic conditions. The causes of lytic lesions were unicameral bone cyst (n = 3), aneurysmal bone cyst (n = 3), giant cell tumor (n = 9), fibrous dysplasia (n = 12), chondromyxoid fibroma, chondroma, nonossifying fibroma (n = 1 each), tubercular osteomyelitis (n = 7), and chronic pyogenic osteomyelitis (n = 5). The cavity of the lesion was thoroughly curetted and compactly filled with matchstick sized allografts. Results: Quantitative assessment based on the criteria of Sethi et al. (1993) was done. There was complete assimilation in 27 cases, partial healing in 12 cases, and failure in 3 cases. Functional assessment was also done according to which there were 29 excellent results, 6 good, and 7 cases of failure (infection, recurrence, and nonunion of pathological fracture). We observed that after

  19. Vascular endothelial growth factor/bone morphogenetic protein-2 bone marrow combined modification of the mesenchymal stem cells to repair the avascular necrosis of the femoral head.

    PubMed

    Ma, Xiao-Wei; Cui, Da-Ping; Zhao, De-Wei

    2015-01-01

    Vascular endothelial cell growth factor (VEGF) combined with bone morphogenetic protein (BMP) was used to repair avascular necrosis of the femoral head, which can maintain the osteogenic phenotype of seed cells, and effectively secrete VEGF and BMP-2, and effectively promote blood vessel regeneration and contribute to formation and revascularization of tissue engineered bone tissues. To observe the therapeutic effect on the treatment of avascular necrosis of the femoral head by using bone marrow mesenchymal stem cells (BMSCs) modified by VEGF-165 and BMP-2 in vitro. The models were avascular necrosis of femoral head of rabbits on right leg. There groups were single core decompression group, core decompression + BMSCs group, core decompression + VEGF-165/BMP-2 transfect BMSCs group. Necrotic bone was cleared out under arthroscope. Arthroscopic observation demonstrated that necrotic bone was cleared out in each group, and fresh blood flowed out. Histomorphology determination showed that blood vessel number and new bone area in the repair region were significantly greater at various time points following transplantation in the core decompression + VEGF-165/BMP-2 transfect BMSCs group compared with single core decompression group and core decompression + BMSCs group (P < 0.05). These suggested that VEGF-165/BMP-2 gene transfection strengthened osteogenic effects of BMSCs, elevated number and quality of new bones and accelerated the repair of osteonecrosis of the femoral head.

  20. Vascular endothelial growth factor/bone morphogenetic protein-2 bone marrow combined modification of the mesenchymal stem cells to repair the avascular necrosis of the femoral head

    PubMed Central

    Ma, Xiao-Wei; Cui, Da-Ping; Zhao, De-Wei

    2015-01-01

    Vascular endothelial cell growth factor (VEGF) combined with bone morphogenetic protein (BMP) was used to repair avascular necrosis of the femoral head, which can maintain the osteogenic phenotype of seed cells, and effectively secrete VEGF and BMP-2, and effectively promote blood vessel regeneration and contribute to formation and revascularization of tissue engineered bone tissues. To observe the therapeutic effect on the treatment of avascular necrosis of the femoral head by using bone marrow mesenchymal stem cells (BMSCs) modified by VEGF-165 and BMP-2 in vitro. The models were avascular necrosis of femoral head of rabbits on right leg. There groups were single core decompression group, core decompression + BMSCs group, core decompression + VEGF-165/BMP-2 transfect BMSCs group. Necrotic bone was cleared out under arthroscope. Arthroscopic observation demonstrated that necrotic bone was cleared out in each group, and fresh blood flowed out. Histomorphology determination showed that blood vessel number and new bone area in the repair region were significantly greater at various time points following transplantation in the core decompression + VEGF-165/BMP-2 transfect BMSCs group compared with single core decompression group and core decompression + BMSCs group (P < 0.05). These suggested that VEGF-165/BMP-2 gene transfection strengthened osteogenic effects of BMSCs, elevated number and quality of new bones and accelerated the repair of osteonecrosis of the femoral head. PMID:26629044

  1. The Effect of Local Delivery Doxycycline and Alendronate on Bone Repair.

    PubMed

    Limirio, Pedro Henrique Justino Oliveira; Rocha, Flaviana Soares; Batista, Jonas Dantas; Guimarães-Henriques, João César; de Melo, Geraldo Batista; Dechichi, Paula

    2016-08-01

    The aim of the present study was to investigate the local effect of 10% doxycycline and 1% alendronate combined with poly(lactic-co-glycolic acid) (PLGA) on bone repair. Thirty rats were divided into three groups, as follows: control group (CG), drug group (DG), and vehicle-PLGA group (VG). Bone defect was created in the right femur and filled with the following: blood clot (CG); PLGA gel, 10% doxycycline and 1% alendronate (DG); or vehicle-PLGA (VG). The animals were euthanized 7 or 15 days after surgery. Bone density, bone matrix and number of osteoclasts were quantified. At 7 days, the findings showed increased density in DG (177.75 ± 76.5) compared with CG (80.37 ± 27.4), but no difference compared with VG (147.1 ± 41.5); no statistical difference in bone neoformation CG (25.6 ± 4.8), VG (27.8 ± 4), and DG (18.9 ± 7.8); and decrease osteoclasts in DG (4.6 ± 1.9) compared with CG (26.7 ± 7.4) and VG (17.3 ± 2.7). At 15 days, DG (405.1 ± 63.1) presented higher density than CG (213.2 ± 60.9) and VG (283.4 ± 85.8); there was a significant increase in percentage of bone neoformation in DG (31.5 ± 4.2) compared with CG (23 ± 4), but no difference compared with VG (25.1 ± 2.9). There was a decreased number of osteoclasts in DG (20.7 ± 4.7) and VG (29.5 ± 5.4) compared with CG (40 ± 9.4). The results suggest that the association of 10% doxycycline and 1% alendronate with PLGA-accelerated bone repair.

  2. Inorganic-organic shape memory polymers and foams for bone defect repairs

    NASA Astrophysics Data System (ADS)

    Zhang, Dawei

    The ultimate goal of this research was to develop a "self-fitting" shape memory polymer (SMP) scaffold for the repair of craniomaxillofacial (CMF) bone defects. CMF defects may be caused by trauma, tumor removal or congenital abnormalities and represent a major class of bone defects. Their repair with autografts is limited by availability, donor site morbidity and complex surgical procedures. In addition, shaping and positioning of these rigid grafts into irregular defects is difficult. Herein, we have developed SMP scaffolds which soften at T > ˜56 °C, allowing them to conformally fit into a bone defect. Upon cooling to body temperature, the scaffold becomes rigid and mechanically locks in place. This research was comprised of four major studies. In the first study, photocrosslinkable acrylated (AcO) SMP macromers containing a poly(epsilon-caprolactone) (PCL) segment and polydimethylsiloxane (PDMS) segments were synthesized with the general formula: AcO-PCL40-block-PDMS m-block-PCL40-OAc. By varying the PDMS segment length (m), solid SMPs with highly tunable mechanical properties and excellent shape memory abilities were prepared. In the second study, porous SMP scaffolds were fabricated based on AcO-PCL 40-block-PDMS37-block-PCL 40-OAc via a revised solvent casting particulate leaching (SCPL) method. By tailoring scaffold parameters including salt fusion, macromer concentration and salt size, scaffold properties (e.g. pore features, compressive modulus and shape memory behavior) were tuned. In the third study, porous SMP scaffolds were produced from macromers with variable PDMS segment lengths (m = 0 -- 130) via an optimized SCPL method. The impact on pore features, thermal, mechanical, and shape memory properties as well as degradation rates were investigated. In the final study, a bioactive polydopamine coating was applied onto pore surfaces of the SMP scaffold prepared from PCL diacrylate. The thin coating did not affect intrinsic bulk properties of the

  3. Effect of laser phototherapy on human alveolar bone repair: micro tomographic and histomorphometrical analysis

    NASA Astrophysics Data System (ADS)

    Romão, Marcia M. A.; Marques, Márcia M.; Cortes, Arthur R. G.; Horliana, Anna C. R. T.; Moreira, Maria S.; Lascala, Cesar A.

    2015-06-01

    The immediate dental implant placement in the molars region is critical, because of the high amount of bone loss and the discrepancy between the alveolar crest thickness and the dental implant platform. Laser phototherapy (LPT) improves bone repair thus could accelerate the implant placement. Twenty patients were selected for the study. Ten patients were submitted to LPT with GaAlAs diode laser (808nm) during molar extraction, immediately after, 24h, 48h, 72h, 96h and 7 days. The irradiations were applied in contact and punctual mode (100mW, 0.04cm2, 0.75J/cm2, 30s per point, 3J per point). The control group (n=10) received the same treatment; however with the power of the laser off. Forty days later samples of the tissue formed inside the sockets were obtained for further microtomography (microCTs) and histomorphometry analyses. Data were compared by the Student t test, whereas those from the different microCT parameters were compared by the Pearson correlation test (p<0.05). The relative bone volume, as well as area was significantly higher (p<0.001) in the lased than the control group. In the control group there were negative correlations between number and thickness, and between number and separation of trabecula (p<0.01). Between thickness and separation of trabecula the correlation was positive (p<0.01). The laser group showed significant negative correlation between the number and the thickness of trabecula (p<0.01). LPT accelerated bone repair. By the Pearson correlation test it was possible to infer that the lased group presented a more homogeneous trabecular configuration, which would allow earlier dental implant placement.

  4. Adverse Biological Effect of TiO2 and Hydroxyapatite Nanoparticles Used in Bone Repair and Replacement

    PubMed Central

    Wang, Jiangxue; Wang, Liting; Fan, Yubo

    2016-01-01

    The adverse biological effect of nanoparticles is an unavoidable scientific problem because of their small size and high surface activity. In this review, we focus on nano-hydroxyapatite and TiO2 nanoparticles (NPs) to clarify the potential systemic toxicological effect and cytotoxic response of wear nanoparticles because they are attractive materials for bone implants and are widely investigated to promote the repair and reconstruction of bone. The wear nanoparticles would be prone to binding with proteins to form protein-particle complexes, to interacting with visible components in the blood including erythrocytes, leukocytes, and platelets, and to being phagocytosed by macrophages or fibroblasts to deposit in the local tissue, leading to the formation of fibrous local pseudocapsules. These particles would also be translocated to and disseminated into the main organs such as the lung, liver and spleen via blood circulation. The inflammatory response, oxidative stress, and signaling pathway are elaborated to analyze the potential toxicological mechanism. Inhibition of the oxidative stress response and signaling transduction may be a new therapeutic strategy for wear debris–mediated osteolysis. Developing biomimetic materials with better biocompatibility is our goal for orthopedic implants. PMID:27231896

  5. From isolation to implantation: a concise review of mesenchymal stem cell therapy in bone fracture repair

    PubMed Central

    2014-01-01

    Compromised bone-regenerating capability following a long bone fracture is often the result of reduced host bone marrow (BM) progenitor cell numbers and efficacy. Without surgical intervention, these malunions result in mobility restrictions, deformities, and disability. The clinical application of BM-derived mesenchymal stem cells (MSCs) is a feasible, minimally invasive therapeutic option to treat non-union fractures. This review focuses on novel, newly identified cell surface markers in both the mouse and human enabling the isolation and purification of osteogenic progenitor cells as well as their direct and indirect contributions to fracture repair upon administration. Furthermore, clinical success to date is summarized with commentary on autologous versus allogeneic cell sources and the methodology of cell administration. Given our clinical success to date in combination with recent advances in the identification, isolation, and mechanism of action of MSCs, there is a significant opportunity to develop improved technologies for defining therapeutic MSCs and potential to critically inform future clinical strategies for MSC-based bone regeneration. PMID:25099622

  6. Calcium phosphate-based composites as injectable bone substitute materials.

    PubMed

    Low, Kah Ling; Tan, Soon Huat; Zein, Sharif Hussein Sharif; Roether, Judith A; Mouriño, Viviana; Boccaccini, Aldo R

    2010-07-01

    A major weakness of current orthopedic implant materials, for instance sintered hydroxyapatite (HA), is that they exist as a hardened form, requiring the surgeon to fit the surgical site around an implant to the desired shape. This can cause an increase in bone loss, trauma to the surrounding tissue, and longer surgical time. A convenient alternative to harden bone filling materials are injectable bone substitutes (IBS). In this article, recent progress in the development and application of calcium phosphate (CP)-based composites use as IBS is reviewed. CP materials have been used widely for bone replacement because of their similarity to the mineral component of bone. The main limitation of bulk CP materials is their brittle nature and poor mechanical properties. There is significant effort to reinforce or improve the mechanical properties and injectability of calcium phosphate cement (CPC) and this review resumes different alternatives presented in this specialized literature. PMID:20336722

  7. The combined use of mesenchymal stromal cells and scaffolds for bone repair.

    PubMed

    Ciapetti, Gabriela; Granchi, Donatella; Baldini, Nicola

    2012-01-01

    A general principle of stem cell therapy is to exploit the natural ability of the human body to heal through the process of regeneration. Here, we review the current status of cell therapy based on adult mesenchymal stem cells (MSC) with emphasis on therapeutic application in bone-related diseases. The main issues for an effective bone engineering strategy include: - A sufficient number of bone-forming cells, where cell yield, separation, expansion, commitment, as well as patient age, are all variables to be considered; - An ECM-like scaffold conductive for and informative to cells, where structural/physico-chemical/mechanical parameters, administration form (injectable or free-form), and degradation rate have to be tuned according to the clinical application; - Biochemical signals, such as growth factors/cytokines to induce osteogenic differentiation, where the choice between autogenous or exogenous sourcing, dose, timing, etc. are critical; - An adequate blood supply, provided by angiogenetic factors, pre-vascularization, pre-implant co-culture of vessel and bone progenitors. We also discuss the safety and efficacy of different approaches, as well as bottlenecks hampering rapid translation of adult MSC therapy from the laboratories to the clinics. A central paradigm for the effective regeneration of bone tissue is the re-creation at the site of injury of a microenvironment as close as possible to the natural MSC repository in the body. This would allow adult MSC to serve as cellular factories, i.e. to express paracrine activity in situ by secretion of inflammatory and reparative cytokines and to cooperate with other cells. The results from a wide array of in vitro and in vivo studies, as well as from some clinical trials, are expanding the range of clinical protocols for bone repair, that is the ultimate goal of orthopaedics.

  8. Bone marrow-derived cells homing for self-repair of periodontal tissues: a histological characterization and expression analysis.

    PubMed

    Wang, Yan; Zhou, Lili; Li, Chen; Xie, Han; Lu, Yuwang; Wu, Ying; Liu, Hongwei

    2015-01-01

    Periodontitis, a disease leads to the formation of periodontal defect, can result in tooth loss if left untreated. The therapies to repair/regenerate periodontal tissues have attracted lots of attention these years. Bone marrow-derived cells (BMDCs), a group of cells containing heterogeneous stem/progenitor cells, are capable of homing to injured tissues and participating in tissue repair/regeneration. The amplification of autologous BMDCs' potential in homing for self-repair/regeneration, therefore, might be considered as an alternative therapy except for traditional cell transplantation. However, the knowledge of the BMDCs' homing and participation in periodontal repair/regeneration is still known little. For the purpose of directly observing BMDCs' involvement in periodontal repair, chimeric mouse models were established to make their bone marrow cells reconstituted with cells expressing green enhanced fluorescence protein (EGFP) in this study. One month after bone marrow transplantation, periodontal defects were made on the mesial side of bilateral maxillary first molars in chimeric mice. The green fluorescence protein-positive (GFP+) BMDCS in periodontal defect regions were examined by bioluminescent imaging and immunofluorescence staining. GFP+ BMDCs were found to aggregate in the periodontal defect regions and emerge in newly-formed bones or fibers. Some of them also co-expressed markers of fibroblasts, osteoblasts or vascular endothelial cells. These results indicated that BMDCs might contribute to the formation of new fibers, bones and blood vessels during periodontal repair. In conclusion, we speculated that autologous BMDCs were capable of negotiating into the surgical sites created by periodontal operation and participating in tissue repair.

  9. Bone marrow-derived cells homing for self-repair of periodontal tissues: a histological characterization and expression analysis

    PubMed Central

    Wang, Yan; Zhou, Lili; Li, Chen; Xie, Han; Lu, Yuwang; Wu, Ying; Liu, Hongwei

    2015-01-01

    Periodontitis, a disease leads to the formation of periodontal defect, can result in tooth loss if left untreated. The therapies to repair/regenerate periodontal tissues have attracted lots of attention these years. Bone marrow-derived cells (BMDCs), a group of cells containing heterogeneous stem/progenitor cells, are capable of homing to injured tissues and participating in tissue repair/regeneration. The amplification of autologous BMDCs’ potential in homing for self-repair/regeneration, therefore, might be considered as an alternative therapy except for traditional cell transplantation. However, the knowledge of the BMDCs’ homing and participation in periodontal repair/regeneration is still known little. For the purpose of directly observing BMDCs’ involvement in periodontal repair, chimeric mouse models were established to make their bone marrow cells reconstituted with cells expressing green enhanced fluorescence protein (EGFP) in this study. One month after bone marrow transplantation, periodontal defects were made on the mesial side of bilateral maxillary first molars in chimeric mice. The green fluorescence protein-positive (GFP+) BMDCS in periodontal defect regions were examined by bioluminescent imaging and immunofluorescence staining. GFP+ BMDCs were found to aggregate in the periodontal defect regions and emerge in newly-formed bones or fibers. Some of them also co-expressed markers of fibroblasts, osteoblasts or vascular endothelial cells. These results indicated that BMDCs might contribute to the formation of new fibers, bones and blood vessels during periodontal repair. In conclusion, we speculated that autologous BMDCs were capable of negotiating into the surgical sites created by periodontal operation and participating in tissue repair. PMID:26722424

  10. Bone substitute material on the basis of natural components

    NASA Astrophysics Data System (ADS)

    Melnikova, S.; Zelichenko, E.; Zenin, B.; Guzeev, V.; Gurova, O.

    2014-10-01

    The creation of regenerative materials remains a problem for rehabilitation medicine, but the obtaining of initial substances that can cause bone tissue regeneration, possessing biological activity and creation on their basis of composite materials with specified physical and mechanical characteristics is an important scientific problem. This paper presents the investigation of physical-chemical and biological properties of bioresorbable composite material that can restore their own bone tissue of the body.

  11. Effect of repair surface design, repair material, and processing method on the transverse strength of repaired acrylic denture resin.

    PubMed

    Ward, J E; Moon, P C; Levine, R A; Behrendt, C L

    1992-06-01

    The transverse strengths of blocks of denture base acrylic resin repaired with autopolymerizing monomer and polymer and autopolymerizing monomer and heat-cured polymer were measured with a three-point bending test. Three repair joints were studied: butt, round, and 45-degree bevel. Three processing methods were used: bench cure, hydroflask with hot water for 10 minutes, and hydroflask with hot water for 30 minutes. The strengths of repairs made with round and 45-degree bevel joint designs were similar and significantly greater than those with a butt joint design. The strengths of repairs processed in a hydroflask for 10 minutes and 30 minutes were similar and significantly greater than those cured on the bench top. There was no difference in the strength of repairs made with autopolymerizing monomer and polymer and autopolymerizing monomer and heat-cured polymer.

  12. Templated repair of long bone defects in rats with bioactive spiral-wrapped electrospun amphiphilic polymer/hydroxyapatite scaffolds.

    PubMed

    Kutikov, Artem B; Skelly, Jordan D; Ayers, David C; Song, Jie

    2015-03-01

    Effective repair of critical-size long bone defects presents a significant clinical challenge. Electrospun scaffolds can be exploited to deliver protein therapeutics and progenitor cells, but their standalone application for long bone repair has not been explored. We have previously shown that electrospun composites of amphiphilic poly(d,l-lactic acid)-co-poly(ethylene glycol)-co-poly(d,l-lactic acid) (PELA) and hydroxyapatite (HA) guide the osteogenic differentiation of bone marrow stromal cells (MSCs), making these scaffolds uniquely suited for evaluating cell-based bone regeneration approaches. Here we examine whether the in vitro bioactivity of these electrospun scaffolds can be exploited for long bone defect repair, either through the participation of exogenous MSCs or through the activation of endogenous cells by a low dose of recombinant human bone morphogenetic protein-2 (rhBMP-2). In critical-size rat femoral segmental defects, spiral-wrapped electrospun HA-PELA with preseeded MSCs resulted in laminated endochondral ossification templated by the scaffold across the longitudinal span of the defect. Using GFP labeling, we confirmed that the exogenous MSCs adhered to HA-PELA survived at least 7 days postimplantation, suggesting direct participation of these exogenous cells in templated bone formation. When loaded with 500 ng of rhBMP-2, HA-PELA spirals led to more robust but less clearly templated bone formation than MSC-bearing scaffolds. Both treatment groups resulted in new bone bridging over the majority of the defect by 12 weeks. This study is the first demonstration of a standalone bioactive electrospun scaffold for templated bone formation in critical-size long bone defects.

  13. EFFECT OF LOW-LEVEL LASER (GAAS, 904HM) FOR BONE REPAIR ON FRACTURES IN RATS

    PubMed Central

    Léo, Jorge Alfredo; Cunha, Alessanda da; de Oliveira, Elias Félix; Prado, Reuder Pereira

    2015-01-01

    Objective: To analyze the effects of low-level laser therapy (GaAs, 904 nm) for bone repair on tibial fractures in rats. Methods: Forty rats were divided into four groups of 10 animals: control group without fracture (CG); fracture group without treatment (EG II); fracture group treated with laser at 10 J/cm2 (EG III); and fracture group treated with laser at 15 J/cm2 (EG IV). The fracture was produced surgically and the treatment lasted 45 days, done on alternate days. After treatment completion, the rats were sacrificed. The tibias were radiographed and subjected to mechanical three-point flexion tests in order to evaluate the maximum force (N) required to break them. Results: The observed maximum force values (N) were: control group (CG) of 51.5 N ± 7.9 N; EG II 17.2 N ± 7.8 N; EG III 16.6 N ± 12.1 N; and EG IV 30.3 N ± 7.8 N. There were statistically significant differences between the control group and the experimental groups and also between experimental group IV and the other experimental groups (II and III). Radiographs showed callus formation in all the fractured groups, thus indicating that they had undergone the normal tissue repair process. Conclusion: EG IV, which underwent laser therapy with a dosage of 15 J/cm2, showed the highest maximum force value (N) among the experimental groups, thus demonstrating the influence of higher laser dosage on bone repair. PMID:27042627

  14. Transcutaneous Raman spectroscopy for assessing progress of bone-graft incorporation in bone reconstruction and repair

    NASA Astrophysics Data System (ADS)

    Okagbare, Paul I.; Esmonde-White, Francis W. L.; Goldstein, Steven A.; Morris, Michael D.

    2011-03-01

    Allografts and other bone-grafts are frequently used for a variety of reconstructive approaches in orthopaedic surgery. However, successful allograft incorporation remains uncertain. Consequently, there is significant need for methods to monitor the fate of these constructs. Only few noninvasive methods can fully assess the progress of graft incorporation and to provide information on the metabolic status of the graft, such as the mineral and matrix composition of the regenerated-tissue that may provide early indications of graft success or failure. For example, Computed-tomography and MRI provide information on the morphology of the graft/host interface. Limited information is also available from DXA. To address this challenge, we present here the implementation of a noninvasive Raman spectroscopy technique for in-vivo assessment of allograft incorporation in animal-model. In an animal use committee approved osseointegration experiment, a 3mm defect is created in rat's tibia. The defect is reconstructed using auto or allograft and Raman spectra are collected at several time-points during healing using an array of optical-fibers in contact with the skin of the rat over the tibia while the rat is anaesthetized. The array allows excitation and collection of Raman spectra through the skin at various positions around the tibia. Raman parameters such as mineral/matrix, carbonate/phosphate and cross-linking are recovered and monitored. The system is calibrated against locally-constructed phantoms that mimic the morphology, optics and spectroscopy of the rat. This new technology provides a non-invasive method for in-vivo assessment of bone-graft incorporation in animal-models and can be adapted for similar study in human subjects.

  15. Creation of bioactive glass (13-93) scaffolds for structural bone repair using a combined finite element modeling and rapid prototyping approach.

    PubMed

    Xiao, Wei; Zaeem, Mohsen Asle; Bal, B Sonny; Rahaman, Mohamed N

    2016-11-01

    There is a clinical need for synthetic bioactive materials that can reliably repair intercalary skeletal tissue loss in load-bearing bones. Bioactive glasses have been investigated as one such material but their mechanical response has been a concern. Previously, we created bioactive silicate glass (13-93) scaffolds with a uniform grid-like microstructure which showed a compressive strength comparable to human cortical bone but a much lower flexural strength. In the present study, finite element modeling (FEM) was used to re-design the scaffold microstructure to improve its flexural strength without significantly lowering its compressive strength and ability to support bone infiltration in vivo. Then scaffolds with the requisite microstructures were created by a robotic deposition method and tested in four-point bending and compression to validate the FEM simulations. In general, the data validated the predictions of the FEM simulations. Scaffolds with a porosity gradient, composed of a less porous outer region and a more porous inner region, showed a flexural strength (34±5MPa) that was more than twice the value for the uniform grid-like microstructure (15±5MPa) and a higher compressive strength (88±20MPa) than the grid-like microstructure (72±10MPa). Upon implantation of the scaffolds for 12weeks in rat calvarial defects in vivo, the amount of new bone that infiltrated the pore space of the scaffolds with the porosity gradient (37±16%) was similar to that for the grid-like scaffolds (35±6%). These scaffolds with a porosity gradient that better mimics the microstructure of human long bone could provide more reliable implants for structural bone repair. PMID:27524065

  16. Creation of bioactive glass (13-93) scaffolds for structural bone repair using a combined finite element modeling and rapid prototyping approach.

    PubMed

    Xiao, Wei; Zaeem, Mohsen Asle; Bal, B Sonny; Rahaman, Mohamed N

    2016-11-01

    There is a clinical need for synthetic bioactive materials that can reliably repair intercalary skeletal tissue loss in load-bearing bones. Bioactive glasses have been investigated as one such material but their mechanical response has been a concern. Previously, we created bioactive silicate glass (13-93) scaffolds with a uniform grid-like microstructure which showed a compressive strength comparable to human cortical bone but a much lower flexural strength. In the present study, finite element modeling (FEM) was used to re-design the scaffold microstructure to improve its flexural strength without significantly lowering its compressive strength and ability to support bone infiltration in vivo. Then scaffolds with the requisite microstructures were created by a robotic deposition method and tested in four-point bending and compression to validate the FEM simulations. In general, the data validated the predictions of the FEM simulations. Scaffolds with a porosity gradient, composed of a less porous outer region and a more porous inner region, showed a flexural strength (34±5MPa) that was more than twice the value for the uniform grid-like microstructure (15±5MPa) and a higher compressive strength (88±20MPa) than the grid-like microstructure (72±10MPa). Upon implantation of the scaffolds for 12weeks in rat calvarial defects in vivo, the amount of new bone that infiltrated the pore space of the scaffolds with the porosity gradient (37±16%) was similar to that for the grid-like scaffolds (35±6%). These scaffolds with a porosity gradient that better mimics the microstructure of human long bone could provide more reliable implants for structural bone repair.

  17. Bone regeneration and infiltration of an anisotropic composite scaffold: an experimental study of rabbit cranial defect repair.

    PubMed

    Li, Jidong; You, Fu; Li, Yubao; Zuo, Yi; Li, Limei; Jiang, Jiaxing; Qu, Yili; Lu, Minpeng; Man, Yi; Zou, Qin

    2016-01-01

    Tissue formation on scaffold outer edges after implantation may restrict cell infiltration and mass transfer to/from the scaffold center due to insufficient interconnectivity, leading to incidence of a necrotic core. Herein, a nano-hydroxyapatite/polyamide66 (n-HA/PA66) anisotropic scaffold with axially aligned channels was prepared with the aim to enhance pore interconnectivity. Bone tissue regeneration and infiltration inside of scaffold were assessed by rabbit cranial defect repair experiments. The amount of newly formed bone inside of anisotropic scaffold was much higher than isotropic scaffold, e.g., after 12 weeks, the new bone volume in the inner pores was greater in the anisotropic scaffolds (>50%) than the isotropic scaffolds (<30%). The results suggested that anisotropic scaffolds could accelerate the inducement of bone ingrowth into the inner pores in the non-load-bearing bone defects compared to isotropic scaffolds. Thus, anisotropic scaffolds hold promise for the application in bone tissue engineering. PMID:26775692

  18. Bone regeneration and infiltration of an anisotropic composite scaffold: an experimental study of rabbit cranial defect repair.

    PubMed

    Li, Jidong; You, Fu; Li, Yubao; Zuo, Yi; Li, Limei; Jiang, Jiaxing; Qu, Yili; Lu, Minpeng; Man, Yi; Zou, Qin

    2016-01-01

    Tissue formation on scaffold outer edges after implantation may restrict cell infiltration and mass transfer to/from the scaffold center due to insufficient interconnectivity, leading to incidence of a necrotic core. Herein, a nano-hydroxyapatite/polyamide66 (n-HA/PA66) anisotropic scaffold with axially aligned channels was prepared with the aim to enhance pore interconnectivity. Bone tissue regeneration and infiltration inside of scaffold were assessed by rabbit cranial defect repair experiments. The amount of newly formed bone inside of anisotropic scaffold was much higher than isotropic scaffold, e.g., after 12 weeks, the new bone volume in the inner pores was greater in the anisotropic scaffolds (>50%) than the isotropic scaffolds (<30%). The results suggested that anisotropic scaffolds could accelerate the inducement of bone ingrowth into the inner pores in the non-load-bearing bone defects compared to isotropic scaffolds. Thus, anisotropic scaffolds hold promise for the application in bone tissue engineering.

  19. Transmission of acoustic emission in bones, implants and dental materials.

    PubMed

    Ossi, Zannar; Abdou, Wael; Reuben, Robert L; Ibbetson, Richard J

    2013-11-01

    There is considerable interest in using acoustic emission (AE) and ultrasound to assess the quality of implant-bone interfaces and to monitor for micro-damage leading to loosening. However, remarkably little work has been done on the transmission of ultrasonic waves though the physical and biological structures involved. The aim of this in vitro study is to assess any differences in transmission between various dental materials and bovine rib bones with various degrees of hydration. Two types of tests have been carried out using pencil lead breaks as a standard AE source. The first set of tests was configured to assess the surface propagation of AE on various synthetic materials compared with fresh bovine rib bone. The second is a set of transmission tests on fresh, dried and hydrated bones each fitted with dental implants with various degrees of fixity, which includes components due to bone and interface transmission. The results indicate that transmission through glass ionomer cement is closest to the bone. This would suggest that complete osseointegration could potentially be simulated using such cement. The transmission of AE energy through bone was found to be dependent on its degree of hydration. It was also found that perfusing samples of fresh bone with water led to an increase in transmitted energy, but this appeared to affect transmission across the interface more than transmission through the bone. These findings have implications not only for implant interface inspection but also for passive AE monitoring of implants.

  20. Chondroitinase ABC plus bone marrow mesenchymal stem cells for repair of spinal cord injury.

    PubMed

    Zhang, Chun; He, Xijing; Li, Haopeng; Wang, Guoyu

    2013-04-15

    As chondroitinase ABC can improve the hostile microenvironment and cell transplantation is proven to be effective after spinal cord injury, we hypothesized that their combination would be a more effective treatment option. At 5 days after T8 spinal cord crush injury, rats were injected with bone marrow mesenchymal stem cell suspension or chondroitinase ABC 1 mm from the edge of spinal cord damage zone. Chondroitinase ABC was first injected, and bone marrow mesenchymal stem cell suspension was injected on the next day in the combination group. At 14 days, the mean Basso, Beattie and Bresnahan score of the rats in the combination group was higher than other groups. Hematoxylin-eosin staining showed that the necrotic area was significantly reduced in the combination group compared with other groups. Glial fibrillary acidic protein-chondroitin sulfate proteoglycan double staining showed that the damage zone of astrocytic scars was significantly reduced without the cavity in the combination group. Glial fibrillary acidic protein/growth associated protein-43 double immunostaining revealed that positive fibers traversed the damage zone in the combination group. These results suggest that the combination of chondroitinase ABC and bone marrow mesenchymal stem cell transplantation contributes to the repair of spinal cord injury.

  1. Enhanced Individual Trabecular Repair and Its Mechanical Implications in Parathyroid Hormone and Alendronate Treated Rat Tibial Bone

    PubMed Central

    Altman, Allison R.; de Bakker, Chantal M. J.; Tseng, Wei-Ju; Chandra, Abhishek; Qin, Ling; Sherry Liu, X.

    2015-01-01

    Combined parathyroid hormone (PTH) and bisphosphonate (alendronate—ALN) therapy has recently been shown to increase bone volume fraction and plate-like trabecular structure beyond either monotherapy. To identify the mechanism through which plate-like structure was enhanced, we used in vivo microcomputed tomography (μCT) of the proximal tibia metaphysis and individual trabecular dynamics (ITD) analysis to quantify connectivity repair (incidences of rod connection and plate perforation filling) and deterioration (incidences of rod disconnection and plate perforation). Three-month-old female, intact rats were scanned before and after a 12 day treatment period of vehicle (Veh, n = 5), ALN (n = 6), PTH (n = 6), and combined (PTH+ALN, n = 6) therapy. Additionally, we used computational simulation and finite element (FE) analysis to delineate the contributions of connectivity repair or trabecular thickening to trabecular bone stiffness. Our results showed that the combined therapy group had greater connectivity repair (5.8 ± 0.5% connected rods and 2.0 ± 0.3% filled plates) beyond that of the Veh group, resulting in the greatest net gain in connectivity. For all treatment groups, increases in bone volume due to thickening (5–31%) were far greater than those due to connectivity repair (2–3%). Newly formed bone contributing only to trabecular thickening caused a 10%, 41%, and 69% increase in stiffness in the ALN, PTH, and PTH+ALN groups, respectively. Moreover, newly formed bone that led to connectivity repair resulted in an additional improvement in stiffness, with the highest in PTH+ALN (by an additional 12%), which was significantly greater than either PTH (5.6%) or ALN (4.5%). An efficiency ratio was calculated as the mean percent increase in stiffness divided by mean percent increase in BV for either thickening or connectivity repair in each treatment. For all treatments, the efficiency ratio of connectivity repair (ALN: 2.9; PTH: 3

  2. Bioactive borate glass promotes the repair of radius segmental bone defects by enhancing the osteogenic differentiation of BMSCs.

    PubMed

    Zhang, Jieyuan; Guan, Junjie; Zhang, Changqing; Wang, Hui; Huang, Wenhai; Guo, Shangchun; Niu, Xin; Xie, Zongping; Wang, Yang

    2015-12-01

    Bioactive borate glass (BG) has emerged as a promising alternative for bone regeneration due to its high osteoinductivity, osteoconductivity, compressive strength, and biocompatibility. However, the role of BG in large segmental bone repair is unclear and little is known about the underlying mechanism of BG's osteoinductivity. In this study, we demonstrated that BG possessed pro-osteogenic effects in an experimental model of critical-sized radius defects. Transplanting BG to radius defects resulted in better repair of bone defects as compared to widely used β-TCP. Histological and morphological analysis indicated that BG significantly enhanced new bone formation. Furthermore, the degradation rate of the BG was faster than that of β-TCP, which matched the higher bone regeneration rate. In addition, ions from BG enhanced cell viability, ALP activity, and osteogenic-related genes expression. Mechanistically, the critical genes Smad1/5 and Dlx5 in the BMP pathway and p-Smad1/5 proteins were significantly elevated after BG transplantation, and these effects could be blocked by the BMP/Smad specific inhibitor. Taken together, our findings suggest that BG could repair large segmental bone defects through activating the BMP/Smad pathway and osteogenic differentiation in BMSCs. PMID:26586668

  3. Bone Grafts

    MedlinePlus

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, ... fractures or cancers. Once your body accepts the bone graft, it provides a framework for growth of new, ...

  4. In Vivo Evaluation of Adipose-Derived Stromal Cells Delivered with a Nanofiber Scaffold for Tendon-to-Bone Repair.

    PubMed

    Lipner, Justin; Shen, Hua; Cavinatto, Leonardo; Liu, Wenying; Havlioglu, Necat; Xia, Younan; Galatz, Leesa M; Thomopoulos, Stavros

    2015-11-01

    Rotator cuff tears are common and cause a great deal of lost productivity, pain, and disability. Tears are typically repaired by suturing the tendon back to its bony attachment. Unfortunately, the structural (e.g., aligned collagen) and compositional (e.g., a gradient in mineral) elements that produce a robust attachment in the healthy tissue are not regenerated during healing, and the repair is prone to failure. Two features of the failed healing response are deposition of poorly aligned scar tissue and loss of bone at the repair site. Therefore, the objective of the current study was to improve tendon-to-bone healing by promoting aligned collagen deposition and increased bone formation using a biomimetic scaffold seeded with pluripotent cells. An aligned nanofibrous poly(lactic-co-glycolic acid) scaffold with a gradient in mineral content was seeded with adipose-derived stromal cells (ASCs) and implanted at the repair site of a rat rotator cuff model. In one group, cells were transduced with the osteogenic factor bone morphogenetic protein 2 (BMP2). The healing response was examined in four groups (suture only, acellular scaffold, cellular scaffold, and cellular BMP2 scaffold) using histologic, bone morphology, and biomechanical outcomes at 14, 28, and 56 days. Histologically, the healing interface was dominated by a fibrovascular scar response in all groups. The acellular scaffold group showed a delayed healing response compared to the other groups. When examining bone morphology parameters, bone loss was evident in the cellular BMP2 group compared to other groups at 28 days. When examining repair-site mechanical properties, strength and modulus were decreased in the cellular BMP2 groups compared to other groups at 28 and 56 days. These results indicated that tendon-to-bone healing in this animal model was dominated by scar formation, preventing any positive effects of the implanted biomimetic scaffold. Furthermore, cells transduced with the osteogenic factor

  5. Strong and bioactive composites containing nano-silica-fused whiskers for bone repair.

    PubMed

    Xu, Hockin H K; Smith, Douglas T; Simon, Carl G

    2004-08-01

    Self-hardening calcium phosphate cement (CPC) sets to form hydroxyapatite with high osteoconductivity, but its brittleness and low strength limit its use to only non-stress bearing locations. Previous studies developed bioactive composites containing hydroxyapatite fillers in Bis-GMA-based composites for bone repair applications, and they possessed higher strength values. However, these strengths were still lower than the strength of cortical bone. The aim of this study was to develop strong and bioactive composites by combining CPC fillers with nano-silica-fused whiskers in a resin matrix, and to characterize the mechanical properties and cell response. Silica particles were fused to silicon carbide whiskers to roughen the whisker surfaces for enhanced retention in the matrix. Mass ratios of whisker:CPC of 1:2, 1:1 and 2:1 were incorporated into a Bis-GMA-based resin and hardened by two-part chemical curing. Composite with only CPC fillers without whiskers served as a control. The specimens were tested using three-point flexure and nano-indentation. Composites with whisker:CPC ratios of 2:1 and 1:1 had flexural strengths (mean+/-SD; n=9) of (164+/-14) MPa and (139+/-22) MPa, respectively, nearly 3 times higher than (54+/-5) MPa of the control containing only CPC fillers (p<0.05). The strength of the new whisker-CPC composites was 3 times higher than the strength achieved in previous studies for conventional bioactive composites containing hydroxyapatite particles in Bis-GMA-based resins. The mechanical properties of the CPC-whisker composites nearly matched those of cortical bone and trabecular bone. Osteoblast-like cell adhesion, proliferation and viability were equivalent on the non-whisker control containing only CPC fillers, on the whisker composite at whisker:CPC of 1:1, and on the tissue culture polystyrene control, suggesting that the new CPC-whisker composite was non-cytotoxic.

  6. Two Stage Repair of Composite Craniofacial Defects with Antibiotic Releasing Porous Poly(methyl methacrylate) Space Maintainers and Bone Regeneration

    NASA Astrophysics Data System (ADS)

    Spicer, Patrick

    Craniofacial defects resulting from trauma and resection present many challenges to reconstruction due to the complex structure, combinations of tissues, and environment, with exposure to the oral, skin and nasal mucosal pathogens. Tissue engineering seeks to regenerate the tissues lost in these defects; however, the composite nature and proximity to colonizing bacteria remain difficult to overcome. Additionally, many tissue engineering approaches have further hurdles to overcome in the regulatory process to clinical translation. As such these studies investigated a two stage strategy employing an antibiotic-releasing porous polymethylmethacrylate space maintainer fabricated with materials currently part of products approved or cleared by the United States Food and Drug Administration, expediting the translation to the clinic. This porous space maintainer holds the bone defect open allowing soft tissue to heal around the defect. The space maintainer can then be removed and one regenerated in the defect. These studies investigated the individual components of this strategy. The porous space maintainer showed similar soft tissue healing and response to non-porous space maintainers in a rabbit composite tissue defect. The antibiotic-releasing space maintainers showed release of antibiotics from 1-5 weeks, which could be controlled by loading and fabrication parameters. In vivo, space maintainers releasing a high dose of antibiotics for an extended period of time increased soft tissue healing over burst release space maintainers in an infected composite tissue defect model in a rabbit mandible. Finally, stabilization of bone defects and regeneration could be improved through scaffold structures and delivery of a bone forming growth factor. These studies illustrate the possibility of the two stage strategy for repair of composite tissue defects of the craniofacial complex.

  7. Stem cells of the suture mesenchyme in craniofacial bone development, repair and regeneration

    PubMed Central

    Maruyama, Takamitsu; Jeong, Jaeim; Sheu, Tzong-Jen; Hsu, Wei

    2016-01-01

    The suture mesenchyme serves as a growth centre for calvarial morphogenesis and has been postulated to act as the niche for skeletal stem cells. Aberrant gene regulation causes suture dysmorphogenesis resulting in craniosynostosis, one of the most common craniofacial deformities. Owing to various limitations, especially the lack of suture stem cell isolation, reconstruction of large craniofacial bone defects remains highly challenging. Here we provide the first evidence for an Axin2-expressing stem cell population with long-term self-renewing, clonal expanding and differentiating abilities during calvarial development and homeostastic maintenance. These cells, which reside in the suture midline, contribute directly to injury repair and skeletal regeneration in a cell autonomous fashion. Our findings demonstrate their true identity as skeletal stem cells with innate capacities to replace the damaged skeleton in cell-based therapy, and permit further elucidation of the stem cell-mediated craniofacial skeletogenesis, leading to revealing the complex nature of congenital disease and regenerative medicine. PMID:26830436

  8. Comparative Study on Functional Effects of Allotransplantation of Bone Marrow Stromal Cells and Adipose Derived Stromal Vascular Fraction on Tendon Repair: A Biomechanical Study in Rabbits

    PubMed Central

    Behfar, Mehdi; Javanmardi, Sara; Sarrafzadeh-Rezaei, Farshid

    2014-01-01

    Objective Tendon never returns to its complete biological and mechanical properties after repair. Bone marrow and, recently, adipose tissue have been used as sources of mesenchymal stem cells which have been proven to enhance tendon healing. In the present study, we compared the effects of allotransplantation of bone marrow derived mesenchymal stromal cells (BMSCs) and adipose derived stromal vascular fraction (SVF) on tendon mechanical properties after experimentally induced flexor tendon transection. Materials and Methods In this experimental study, we used 48 adult male New Zealand white rabbits. Twelve of rabbits were used as donors of bone marrow and adipose tissue, the rest were divided into control and treatment groups. The injury model was a unilateral complete transection of the deep digital flexor tendon. Immediately after suture repair, 4×106cells of either fresh SVF from enzymatic digestion of adipose tissue or cultured BMSCs were intratendinously injected into tendon stumps in the treatment groups. Controls received phosphate-buffered saline (PBS). Immobilization with a cast was continued for two weeks after surgery. Animals were sacrificed three and eight weeks after surgery and tendons underwent mechanical evaluations. The differences among the groups were analyzed using the analysis of variance (ANOVA) test followed by Tukey’s multiple comparisons test. Results Stromal cell transplantation resulted in a significant increase in ultimate and yield loads, energy absorption, and stress of repairs compared to the controls. However, there were no statistically significant changes detected in terms of stiffness. In comparison, we observed no significant differences at the third week between SVF and BMSCs treated tendons in terms of all load related properties. However, at the eighth week SVF transplantation resulted in significantly increased energy absorption, stress and stiffness compared to BMSCs. Conclusion The enhanced biomechanical properties of

  9. The mechanics of PLGA nanofiber scaffolds with biomimetic gradients in mineral for tendon-to-bone repair.

    PubMed

    Lipner, J; Liu, W; Liu, Y; Boyle, J; Genin, G M; Xia, Y; Thomopoulos, S

    2014-12-01

    Attachment of dissimilar materials is prone to failure due to stress concentrations that can arise their interface. A compositionally or structurally graded transition can dissipate these stress concentrations and thereby toughen an attachment. The interface between compliant tendon and stiff bone utilizes a monotonic change in hydroxylapatite mineral ("mineral") content to produce a gradient in mechanical properties and mitigate stress concentrations. Previous efforts to mimic the natural tendon-to-bone attachment have included electrospun nanofibrous polymer scaffolds with gradients in mineral. Mineralization of the nanofiber scaffolds has typically been achieved using simulated body fluid (SBF). Depending on the specific formulation of SBF, mineral morphologies ranged from densely packed small crystals to platelike crystal florets. Although this mineralization of scaffolds produced increases in modulus, the peak modulus achieved remained significantly below that of bone. Missing from these prior empirical approaches was insight into the effect of mineral morphology on scaffold mechanics and on the potential for the approach to ultimately achieve moduli approaching that of bone. Here, we applied two mineralization methods to generate scaffolds with spatial gradations in mineral content, and developed methods to quantify the stiffening effects and evaluate them in the context of theoretical bounds. We asked whether either of the mineralization methods we developed holds potential to achieve adequate stiffening of the scaffold, and tested the hypothesis that the smoother, denser mineral coating could attain more potent stiffening effects. Testing this hypothesis required development of and comparison to homogenization bounds, and development of techniques to estimate mineral volume fractions and spatial gradations in modulus. For both mineralization strategies, energy dispersive X-ray analysis demonstrated the formation of linear gradients in mineral concentration

  10. The effect of acoustic radiation force on osteoblasts in cell/hydrogel constructs for bone repair

    PubMed Central

    Veronick, James; Assanah, Fayekah; Nair, Lakshmi S; Vyas, Varun; Huey, Bryan

    2016-01-01

    Ultrasound, or the application of acoustic energy, is a minimally invasive technique that has been used in diagnostic, surgical, imaging, and therapeutic applications. Low-intensity pulsed ultrasound (LIPUS) has been used to accelerate bone fracture repair and to heal non-union defects. While shown to be effective the precise mechanism behind its utility is still poorly understood. In this study, we considered the possibility that LIPUS may be providing a physical stimulus to cells within bony defects. We have also evaluated ultrasound as a means of producing a transdermal physical force that could stimulate osteoblasts that had been encapsulated within collagen hydrogels and delivered to bony defects. Here we show that ultrasound does indeed produce a measurable physical force and when applied to hydrogels causes their deformation, more so as ultrasound intensity was increased or hydrogel stiffness decreased. MC3T3 mouse osteoblast cells were then encapsulated within hydrogels to measure the response to this force. Statistically significant elevated gene expression for alkaline phosphatase and osteocalcin, both well-established markers of osteoblast differentiation, was noted in encapsulated osteoblasts (p < 0.05), suggesting that the physical force provided by ultrasound may induce bone formation in part through physically stimulating cells. We have also shown that this osteoblastic response is dependent in part on the stiffness of the encapsulating hydrogel, as stiffer hydrogels resulted in reducing or reversing this response. Taken together this approach, encapsulating cells for implantation into a bony defect that can potentially be transdermally loaded using ultrasound presents a novel regenerative engineering approach to enhanced fracture repair. PMID:27229906

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

    PubMed

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

    2010-01-01

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

  12. Cellular and morphological aspects of fibrodysplasia ossificans progressiva. Lessons of formation, repair, and bone bioengineering.

    PubMed

    Martelli, Anderson; Santos, Arnaldo Rodrigues

    2014-01-01

    Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disease that causes bone formation within the muscles, tendons, ligaments and connective tissues. There is no cure for this disorder and only treatment of the symptoms is available. The purpose of this study was to review the literature and describe the clinical, cellular and molecular aspects of FOP. The material used for the study was obtained by reviewing scientific articles published in various literature-indexed databases. In view of its rarity and of the lack of insightful information and the unpredictability of its course, FOP is a challenging disorder for professionals who are confronted by it. However, this rare disease raises a great deal of interest because understanding the mechanism of mature bone formation can encourage research lines related to bone regeneration and the prevention of heterotopic ossification.

  13. Transplantation of bone marrow derived cells promotes pancreatic islet repair in diabetic mice

    SciTech Connect

    Gao Xiaodong; Song Lujun; Shen Kuntang; Wang Hongshan; Niu Weixin Qin Xinyu

    2008-06-20

    The transplantation of bone marrow (BM) derived cells to initiate pancreatic regeneration is an attractive but as-yet unrealized strategy. Presently, BM derived cells from green fluorescent protein transgenic mice were transplanted into diabetic mice. Repair of diabetic islets was evidenced by reduction of hyperglycemia, increase in number of islets, and altered pancreatic histology. Cells in the pancreata of recipient mice co-expressed BrdU and insulin. Double staining revealed {beta} cells were in the process of proliferation. BrdU{sup +} insulin{sup -} PDX-1{sup +} cells, Ngn3{sup +} cells and insulin{sup +} glucagon{sup +} cells, which showed stem cells, were also found during {beta}-cell regeneration. The majority of transplanted cells were mobilized to the islet and ductal regions. In recipient pancreas, transplanted cells simultaneously expressed CD34 but did not express insulin, PDX-1, Ngn3, Nkx2.2, Nkx6.1, Pax4, Pax6, and CD45. It is concluded that BM derived cells especially CD34{sup +} cells can promote repair of pancreatic islets. Moreover, both proliferation of {beta} cells and differentiation of pancreatic stem cells contribute to the regeneration of {beta} cells.

  14. Adult stem cells for cardiac repair: a choice between skeletal myoblasts and bone marrow stem cells.

    PubMed

    Ye, Lei; Haider, Husnain Kh; Sim, Eugene K W

    2006-01-01

    The real promise of a stem cell-based approach for cardiac regeneration and repair lies in the promotion of myogenesis and angiogenesis at the site of the cell graft to achieve both structural and functional benefits. Despite all of the progress and promise in this field, many unanswered questions remain; the answers to these questions will provide the much-needed breakthrough to harness the real benefits of cell therapy for the heart in the clinical perspective. One of the major issues is the choice of donor cell type for transplantation. Multiple cell types with varying potentials have been assessed for their ability to repopulate the infarcted myocardium; however, only the adult stem cells, that is, skeletal myoblasts (SkM) and bone marrow-derived stem cells (BMC), have been translated from the laboratory bench to clinical use. Which of these two cell types will provide the best option for clinical application in heart cell therapy remains arguable. With results pouring in from the long-term follow-ups of previously conducted phase I clinical studies, and with the onset of phase II clinical trials involving larger population of patients, transplantation of stem cells as a sole therapy without an adjunct conventional revascularization procedure will provide a deeper insight into the effectiveness of this approach. The present article discusses the pros and cons of using SkM and BMC individually or in combination for cardiac repair, and critically analyzes the progress made with each cell type.

  15. Micro-computed tomography and histomorphometric analysis of human alveolar bone repair induced by laser phototherapy: a pilot study.

    PubMed

    Romão, M M A; Marques, M M; Cortes, A R G; Horliana, A C R T; Moreira, M S; Lascala, C A

    2015-12-01

    Immediate dental implant placement in the molar region is critical, because of the high amount of bone loss and the discrepancy between alveolar crest thickness and the implant platform. Laser phototherapy (LPT) improves bone repair. The aim of this study was to evaluate the human alveolar bone repair 40 days after molar extraction in patients submitted to LPT. Twenty patients were selected for this randomized controlled clinical trial; 10 underwent LPT (laser group) with a GaAlAs diode laser (808 nm, 100 mW, 0.04 cm(2), 75 J/cm(2), 30s per point, 3 J per point, at five points). The control group patients (n=10) were not irradiated. Forty days later, the tissue formed inside the sockets was analyzed by micro-computed tomography and histomorphometry. Data from the two groups were compared with Student's t-test and Pearson's correlation test. The relative bone volume was significantly higher in the laser group (P<0.0001). The control group showed negative correlations (P<0.01) between number and thickness, and between number and separation of trabeculae, and a positive correlation between thickness and separation of trabeculae. The laser group showed a significant negative correlation between the number and thickness of trabeculae (P<0.01). The results suggest that LPT is able to accelerate alveolar bone repair after molar extraction, leading to a more homogeneous trabecular configuration represented by thin and close trabeculae.

  16. Material Properties of the Mandibular Trabecular Bone

    PubMed Central

    Lakatos, Éva; Magyar, Lóránt; Bojtár, Imre

    2014-01-01

    The present paper introduces a numerical simulation aided, experimental method for the measurement of Young's modulus of the trabecular substance in the human mandible. Compression tests were performed on fresh cadaveric samples containing trabecular bone covered with cortical layer, thus avoiding the destruction caused by the sterilization, preservation, and storage and the underestimation of the stiffness resulting from the individual failure of the trabeculae cut on the surfaces. The elastic modulus of the spongiosa was determined by the numerical simulation of each compression test using a specimen specific finite element model of each sample. The received mandibular trabecular bone Young's modulus values ranged from 6.9 to 199.5 MPa. PMID:27006933

  17. Role of donor and host cells in muscle-derived stem cell-mediated bone repair: differentiation vs. paracrine effects

    PubMed Central

    Gao, Xueqin; Usas, Arvydas; Proto, Jonathan D.; Lu, Aiping; Cummins, James H.; Proctor, Alexander; Chen, Chien-Wen; Huard, Johnny

    2014-01-01

    Murine muscle-derived stem cells (MDSCs) have been shown capable of regenerating bone in a critical size calvarial defect model when transduced with BMP 2 or 4; however, the contribution of the donor cells and their interactions with the host cells during the bone healing process have not been fully elucidated. To address this question, C57/BL/6J mice were divided into MDSC/BMP4/GFP, MDSC/GFP, and scaffold groups. After transplanting MDSCs into the critical-size calvarial defects created in normal mice, we found that mice transplanted with BMP4GFP-transduced MDSCs healed the bone defect in 4 wk, while the control groups (MDSC-GFP and scaffold) demonstrated no bone healing. The newly formed trabecular bone displayed similar biomechanical properties as the native bone, and the donor cells directly participated in endochondral bone formation via their differentiation into chondrocytes, osteoblasts, and osteocytes via the BMP4-pSMAD5 and COX-2-PGE2 signaling pathways. In contrast to the scaffold group, the MDSC groups attracted more inflammatory cells initially and incurred faster inflammation resolution, enhanced angiogenesis, and suppressed initial immune responses in the host mice. MDSCs were shown to attract macrophages via the secretion of monocyte chemotactic protein 1 and promote endothelial cell proliferation by secreting multiple growth factors. Our findings indicated that BMP4GFP-transduced MDSCs not only regenerated bone by direct differentiation, but also positively influenced the host cells to coordinate and promote bone tissue repair through paracrine effects.—Gao, X., Usas, A., Proto, J. D., Lu, A., Cummins, J. H., Proctor, A., Chen, C.-W., Huard, J. Role of donor and host cells in muscle-derived stem cell-mediated bone repair: differentiation vs. paracrine effects. PMID:24843069

  18. Cell based advanced therapeutic medicinal products for bone repair: Keep it simple?

    PubMed

    Leijten, J; Chai, Y C; Papantoniou, I; Geris, L; Schrooten, J; Luyten, F P

    2015-04-01

    The development of cell based advanced therapeutic medicinal products (ATMPs) for bone repair has been expected to revolutionize the health care system for the clinical treatment of bone defects. Despite this great promise, the clinical outcomes of the few cell based ATMPs that have been translated into clinical treatments have been far from impressive. In part, the clinical outcomes have been hampered because of the simplicity of the first wave of products. In response the field has set-out and amassed a plethora of complexities to alleviate the simplicity induced limitations. Many of these potential second wave products have remained "stuck" in the development pipeline. This is due to a number of reasons including the lack of a regulatory framework that has been evolving in the last years and the shortage of enabling technologies for industrial manufacturing to deal with these novel complexities. In this review, we reflect on the current ATMPs and give special attention to novel approaches that are able to provide complexity to ATMPs in a straightforward manner. Moreover, we discuss the potential tools able to produce or predict 'goldilocks' ATMPs, which are neither too simple nor too complex.

  19. Cell based advanced therapeutic medicinal products for bone repair: Keep it simple?

    PubMed

    Leijten, J; Chai, Y C; Papantoniou, I; Geris, L; Schrooten, J; Luyten, F P

    2015-04-01

    The development of cell based advanced therapeutic medicinal products (ATMPs) for bone repair has been expected to revolutionize the health care system for the clinical treatment of bone defects. Despite this great promise, the clinical outcomes of the few cell based ATMPs that have been translated into clinical treatments have been far from impressive. In part, the clinical outcomes have been hampered because of the simplicity of the first wave of products. In response the field has set-out and amassed a plethora of complexities to alleviate the simplicity induced limitations. Many of these potential second wave products have remained "stuck" in the development pipeline. This is due to a number of reasons including the lack of a regulatory framework that has been evolving in the last years and the shortage of enabling technologies for industrial manufacturing to deal with these novel complexities. In this review, we reflect on the current ATMPs and give special attention to novel approaches that are able to provide complexity to ATMPs in a straightforward manner. Moreover, we discuss the potential tools able to produce or predict 'goldilocks' ATMPs, which are neither too simple nor too complex. PMID:25451134

  20. Osteoconductivity of modified fluorcanasite glass-ceramics for bone tissue augmentation and repair.

    PubMed

    Bandyopadhyay-Ghosh, S; Faria, P E P; Johnson, A; Felipucci, D N B; Reaney, I M; Salata, L A; Brook, I M; Hatton, P V

    2010-09-01

    Modified fluorcanasite glasses were fabricated by either altering the molar ratios of Na(2)O and CaO or by adding P(2)O(5) to the parent stoichiometric glass compositions. Glasses were converted to glass-ceramics by a controlled two-stage heat treatment process. Rods (2 mm x 4 mm) were produced using the conventional lost-wax casting technique. Osteoconductive 45S5 bioglass was used as a reference material. Biocompatibility and osteoconductivity were investigated by implantation into healing defects (2 mm) in the midshaft of rabbit femora. Tissue response was investigated using conventional histology and scanning electron microscopy. Histological and histomorphometric evaluation of specimens after 12 weeks implantation showed significantly more bone contact with the surface of 45S5 bioglass implants when compared with other test materials. When the bone contact for each material was compared between experimental time points, the Glass-Ceramic 2 (CaO rich) group showed significant difference (p = 0.027) at 4 weeks, but no direct contact at 12 weeks. Histology and backscattered electron photomicrographs showed that modified fluorcanasite glass-ceramic implants had greater osteoconductivity than the parent stoichiometric composition. Of the new materials, fluorcanasite glass-ceramic implants modified by the addition of P(2)O(5) showed the greatest stimulation of new mineralized bone tissue formation adjacent to the implants after 4 and 12 weeks implantation.

  1. Stimulation of Rotator Cuff Repair by Sustained Release of Bone Morphogenetic Protein-7 Using a Gelatin Hydrogel Sheet

    PubMed Central

    Kabuto, Yukichi; Morihara, Toru; Sukenari, Tsuyoshi; Kida, Yoshikazu; Oda, Ryo; Arai, Yuji; Sawada, Koshiro; Matsuda, Ken-Ichi; Kawata, Mitsuhiro; Tabata, Yasuhiko; Kubo, Toshikazu

    2015-01-01

    Bone morphogenetic protein-7 (BMP-7) promotes not only osteogenesis but also matrix production in chondrocytes and tenocytes. However, because of its short half-life, maintaining local concentrations of BMP-7 is difficult. We examined the use of a gelatin hydrogel sheet (GHS) for the sustained release of BMP-7 in stimulating rotator cuff repair at the tendon-to-bone insertion. Twelve-week-old male Sprague-Dawley rats were used. Radiolabeled BMP-7 (125I-BMP-7) was injected into the subacromial bursa in the 125I-BMP-7 group, whereas a GHS impregnated with 125I-BMP-7 was implanted on the tendon attached to the tendon-to-bone insertion in the 125I-BMP-7+GHS group. Levels of 125I-BMP-7 in the tendon-to-bone insertion were assessed at 1, 3, 7, 14, and 21 postoperative days. The BMP-7 concentrations were significantly higher in the 125I-BMP-7+GHS group than in the 125I-BMP-7 group. Next, the bilateral supraspinatus tendons were resected and sutured to the greater tuberosity of the humerus using the Mason-Allen technique. Treatment groups were created as follows: either phosphate-buffered saline (PBS) or BMP-7 was injected into the subacromial bursa in the PBS and BMP-7 groups, whereas a GHS impregnated with either PBS or BMP-7 was implanted on the repaired tendon attached to the tendon-to-bone insertion in the PBS+GHS and BMP-7+GHS groups. The resected specimens were stained at 2, 4, and 8 postoperative weeks with hematoxylin and eosin as well as Safranin O, and tissue repair was evaluated histologically by using the tendon-to-bone maturing score. Tissue repair was assessed biomechanically at 4 and 8 postoperative weeks. The BMP-7+GHS group at 8 postoperative weeks demonstrated a favorable cartilage matrix production and tendon orientation; moreover, the tendon-to-bone maturing score and the ultimate force-to-failure were the highest in this group. The ability of GHS to provide controlled release of various growth factors has been previously reported. We confirmed that

  2. Designer Dual Therapy Nanolayered Implant Coatings Eradicate Biofilms and Accelerate Bone Tissue Repair.

    PubMed

    Min, Jouha; Choi, Ki Young; Dreaden, Erik C; Padera, Robert F; Braatz, Richard D; Spector, Myron; Hammond, Paula T

    2016-04-26

    Infections associated with orthopedic implants cause increased morbidity and significant healthcare cost. A prolonged and expensive two-stage procedure requiring two surgical steps and a 6-8 week period of joint immobilization exists as today's gold standard for the revision arthroplasty of an infected prosthesis. Because infection is much more common in implant replacement surgeries, these issues greatly impact long-term patient care for a continually growing part of the population. Here, we demonstrate that a single-stage revision using prostheses coated with self-assembled, hydrolytically degradable multilayers that sequentially deliver the antibiotic (gentamicin) and the osteoinductive growth factor (BMP-2) in a time-staggered manner enables both eradication of established biofilms and complete and rapid bone tissue repair around the implant in rats with induced osteomyelitis. The nanolayered construct allows precise independent control of release kinetics and loading for each therapeutic agent in an infected implant environment. Antibiotics contained in top layers can be tuned to provide a rapid release at early times sufficient to eliminate infection, followed by sustained release for several weeks, and the underlying BMP-2 component enables a long-term sustained release of BMP-2, which induced more significant and mechanically competent bone formation than a short-term burst release. The successful growth factor-mediated osteointegration of the multilayered implants with the host tissue improved bone-implant interfacial strength 15-fold when compared with the uncoated one. These findings demonstrate the potential of this layered release strategy to introduce a durable next-generation implant solution, ultimately an important step forward to future large animal models toward the clinic.

  3. Improving bone repair of femoral and radial defects in rabbit by incorporating PRP into PLGA/CPC composite scaffold with unidirectional pore structure.

    PubMed

    He, Fupo; Chen, Yan; Li, Jiyan; Lin, Bomiao; Ouyang, Yi; Yu, Bo; Xia, Yuanyou; Yu, Bo; Ye, Jiandong

    2015-04-01

    In this study, a platelet-rich plasma poly(lactic-co-glycolic acid) (PRP-PLGA)/calcium phosphate cement (CPC) composite scaffold was prepared by incorporating PRP into PLGA/CPC scaffold with unidirectional pore structure, which was fabricated by the unidirectional freeze casting of CPC slurry and the following infiltration of PLGA. The results from in vitro cell experiments and in vivo implantation in femoral defects manifested that incorporation of PRP into PLGA/CPC scaffold improved in vitro cell response (cell attachment, proliferation, and differentiation), and markedly boosted bone formation, angiogenesis and material degradation. The incorporation of PRP into scaffold showed more outstanding improvement in osteogenesis as the scaffolds were used to repair the segmental radial defects, especially at the early stage. The new bone tissues grew along the unidirectional lamellar pores of scaffold. At 12 weeks postimplantation, the segmental radial defects treated with PRP-PLGA/CPC scaffold had almost recuperated, whereas treated with the scaffold without PRP was far from healed. Taken together, the PRP-PLGA/CPC scaffold with unidirectional pore structure is a promising candidate to repair bone defects at various sites.

  4. Decreases in bone blood flow and bone material properties in aging Fischer-344 rats

    NASA Technical Reports Server (NTRS)

    Bloomfield, Susan A.; Hogan, Harry A.; Delp, Michael D.

    2002-01-01

    The purpose of this study was to quantify precisely aging-induced changes in skeletal perfusion and bone mechanical properties in a small rodent model. Blood flow was measured in conscious juvenile (2 months old), adult (6 months old), and aged (24 months old) male Fischer-344 rats using radiolabeled microspheres. There were no significant differences in bone perfusion rate or vascular resistance between juvenile and adult rats. However, blood flow was lower in aged versus adult rats in the forelimb bones, scapulas, and femurs. To test for functional effects of this decline in blood flow, bone mineral density and mechanical properties were measured in rats from these two age groups. Bone mineral density and cross-sectional moment of inertia in femoral and tibial shafts and the femoral neck were significantly larger in the aged versus adult rats, resulting in increased (+14%-53%) breaking strength and stiffness. However, intrinsic material properties at midshaft of the long bones were 12% to 25% lower in the aged rats. Although these data are consistent with a potential link between decreased perfusion and focal alterations in bone remodeling activity related to clinically relevant bone loss, additional studies are required to establish the mechanisms for this putative relationship.

  5. Bone material properties in premenopausal women with idiopathic osteoporosis

    PubMed Central

    Misof, BM; Gamsjaeger, S; Cohen, A; Hofstetter, B; Roschger, P; Stein, E; Nickolas, TL; Rogers, HF; Dempster, D; Zhou, H; Recker, R; Lappe, J; McMahon, D; Paschalis, EP; Fratzl, P; Shane, E; Klaushofer, K

    2012-01-01

    Idiopathic osteoporosis (IOP) in premenopausal women is characterized by fragility fractures at low or normal bone mineral density (BMD) in otherwise healthy women with normal gonadal function. Histomorphometric analysis of transiliac bone biopsy samples has revealed microarchitectural deterioration of cancellous bone and thinner cortices. To examine bone material quality, we measured the bone mineralization density distribution (BMDD) in biopsy samples by quantitative backscattered electron imaging (qBEI), and mineral/matrix ratio, mineral crystallinity/maturity, relative proteoglycan content and collagen cross-link ratio at actively bone forming trabecular surfaces by Raman and Fourier Transform Infrared (FTIRM) microspectroscopic techniques. The study groups included: premenopausal women with idiopathic fractures (IOP, n=45), or idiopathic low BMD (Z-score ≤-2.0 at spine and/or hip) but no fractures (ILBMD, n=19), and healthy controls (CONTROL, n=38). BMDD of cancellous bone showed slightly lower mineral content in IOP (both Cn.CaMean and Cn.CaPeak are 1.4% lower) and in ILBMD (both are 1.6% lower, p<0.05) versus CONTROL, but no difference between IOP and ILBMD. Similar differences were found when affected groups were combined versus CONTROL. The differences remained significant after adjustment for mineralizing surface (MS/BS), suggesting that the reduced mineralization of bone matrix cannot be completely accounted for by differences in bone turnover. Raman and FTIRM analysis at forming bone surfaces showed no differences between combined IOP/ILBMD groups versus CONTROL, with the exceptions of increased proteoglycan content per mineral content and increased collagen cross-link ratio. When the two affected subgroups were considered individually, mineral/matrix ratio and collagen cross-link ratio were higher in IOP than ILBMD. In conclusion, our findings suggest that bone material properties differ between premenopausal women with IOP/ILBMD and normal controls

  6. Automotive Engine Maintenance and Repair, 8-1. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Marine Corps, Washington, DC.

    These military-developed curriculum materials consist of six individualized lessons dealing with automotive engine maintenance and repair. Covered in the individual volumes are basic engine construction and operation, engine and engine components design, engine malfunction diagnosis and remedy, engine disassembly, engine repair, and engine repair…

  7. [Integration properties of bone substitute materials. Experimental studies on animals].

    PubMed

    Günther, K P; Scharf, H P; Pesch, H J; Puhl, W

    1998-02-01

    In order to avoid the potential risks of disease transmission in allograft surgery, numerous substitute materials have been described. As the biological response to implant materials is different, we undertook the following study to assess type and amount of bone ingrowth in CaP-ceramics. 105 cylindrical bone defects with a diameter of 5.4 mm were created surgically in the femoral condyles of 53 skeletal mature NZW rabbits. The defects were filled with crushed coralline hydroxyapatite (HA) implants (n = 21), synthetically produced hydroxyapatite (n = 21) and surface-modified alpha-Tricalciumphosphate (TCP) grains (n = 21). 21 defects were left empty and other drill holes were filled with rabbit cancellous bone cylinders (n = 21) after 3 months of cryopreservation at -78 degrees C without sterilization. Following observation periods of 2, 4, 6, 8, 12, 26 and 52 weeks the femoral condyles were harvested for histological evaluation and quantitative analysis of bone ingrowth. Woven bone formation at implant periphery can be observed in all substances as early as 2 weeks postoperatively. At 4-week-intervals cryopreserved allografts show new bone apposition on surfaces of necrotic trabeculae and graft-host junctions by a predominantly osteoblastic reaction at the periphery of all cylinders, while in HA- and TCP-grains early bone formation in the center of drill holes is detectable as well. There is a direct contact between HA-/TCP-particles and newly formed bone without fibrous tissue formation at the implant surfaces. Central new bone formation in rabbit allografts can be observed after 6 to 8 weeks together with a secondary osteoclastic resorption of necrotic transplant trabeculae. The result of this remodeling process is a complete degradation of transplant cylinders with reorganization of vital trabeculae oriented in a mature pattern after 12 to 26 weeks. In contrast the HA- and TCP-implants did not show any signs of resorption. PMID:9530667

  8. Spontaneous Bone Healing after Cysts Enucleation without Bone Grafting Materials: A Randomized Clinical Study

    PubMed Central

    Rubio, Eduardo Daniel; Mombrú, Carlos Mariano

    2014-01-01

    The aim of this study was to evaluate spontaneous bone regeneration after cysts enucleation of the jaws without the use of bone grafting materials. We included 18 patients at random (11 men and 7 women) with a mean age of 31.8 years, with jaw cysts treated by enucleation, without the use of grafting materials. A method of measurements to assess the percentage of reduction of the bone cavities was used to objectify the results. The patients were evaluated before and at least 6 months after surgery, with radiographic scans based on linear measures with a computerized method using Nemoceph program (Nemotec, NemoCeph Software, Madrid, España). The analysis of the sample shows an average of 85.59% decrease in horizontal measures, 89.53% in the vertical, and 88.98 and 89.81% in the diagonal left and right, respectively. The total average reduction was 88.47%. It showed a greater decrease in vertical and diagonal measurements with respect to horizontal. Regeneration in 12 patients was 100% and in 6 patients was higher at 50.4%. Bone density increased in the postoperative radiographs. The results suggest that in some cases, spontaneous bone regeneration can be achieved by cysts enucleation without bone grafting materials. PMID:25709749

  9. Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model.

    PubMed

    Barrientos-Durán, Antonio; Carpenter, Ellen M; Zur Nieden, Nicole I; Malinin, Theodore I; Rodríguez-Manzaneque, Juan Carlos; Zanello, Laura P

    2014-01-01

    The clinical management of bone defects caused by trauma or nonunion fractures remains a challenge in orthopedic practice due to the poor integration and biocompatibility properties of the scaffold or implant material. In the current work, the osteogenic properties of carboxyl-modified single-walled carbon nanotubes (COOH-SWCNTs) were investigated in vivo and in vitro. When human preosteoblasts and murine embryonic stem cells were cultured on coverslips sprayed with COOH-SWCNTs, accelerated osteogenic differentiation was manifested by increased expression of classical bone marker genes and an increase in the secretion of osteocalcin, in addition to prior mineralization of the extracellular matrix. These results predicated COOH-SWCNTs' use to further promote osteogenic differentiation in vivo. In contrast, both cell lines had difficulties adhering to multi-walled carbon nanotube-based scaffolds, as shown by scanning electron microscopy. While a suspension of SWCNTs caused cytotoxicity in both cell lines at levels >20 μg/mL, these levels were never achieved by release from sprayed SWCNTs, warranting the approach taken. In vivo, human allografts formed by the combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone

  10. Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model

    PubMed Central

    Barrientos-Durán, Antonio; Carpenter, Ellen M; zur Nieden, Nicole I; Malinin, Theodore I; Rodríguez-Manzaneque, Juan Carlos; Zanello, Laura P

    2014-01-01

    The clinical management of bone defects caused by trauma or nonunion fractures remains a challenge in orthopedic practice due to the poor integration and biocompatibility properties of the scaffold or implant material. In the current work, the osteogenic properties of carboxyl-modified single-walled carbon nanotubes (COOH–SWCNTs) were investigated in vivo and in vitro. When human preosteoblasts and murine embryonic stem cells were cultured on coverslips sprayed with COOH–SWCNTs, accelerated osteogenic differentiation was manifested by increased expression of classical bone marker genes and an increase in the secretion of osteocalcin, in addition to prior mineralization of the extracellular matrix. These results predicated COOH–SWCNTs’ use to further promote osteogenic differentiation in vivo. In contrast, both cell lines had difficulties adhering to multi-walled carbon nanotube-based scaffolds, as shown by scanning electron microscopy. While a suspension of SWCNTs caused cytotoxicity in both cell lines at levels >20 μg/mL, these levels were never achieved by release from sprayed SWCNTs, warranting the approach taken. In vivo, human allografts formed by the combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone

  11. Bone cysts after osteochondral allograft repair of cartilage defects in goats suggest abnormal interaction between subchondral bone and overlying synovial joint tissues.

    PubMed

    Pallante-Kichura, Andrea L; Cory, Esther; Bugbee, William D; Sah, Robert L

    2013-11-01

    The efficacy of osteochondral allografts (OCAs) may be affected by osseous support of the articular cartilage, and thus affected by bone healing and remodeling in the OCA and surrounding host. Bone cysts, and their communication pathways, may be present in various locations after OCA insertion and reflect distinct pathogenic mechanisms. Previously, we analyzed the effect of OCA storage (FRESH, 4°C/14d, 4°C/28d, FROZEN) on cartilage quality in fifteen adult goats after 12months in vivo. The objectives of this study were to further analyze OCAs and contralateral non-operated (Non-Op) CONTROLS from the medial femoral condyle to (1) determine the effect of OCA storage on local subchondral bone (ScB) and trabecular bone (TB) structure, (2) characterize the location and structure of bone cysts and channels, and (3) assess the relationship between cartilage and bone properties. (1) Overall bone structure after OCAs was altered compared to Non-Op, with OCA samples displaying bone cysts, ScB channels, and ScB roughening. ScB BV/TV in FROZEN OCAs was lower than Non-Op and other OCAs. TB BV/TV in FRESH, 4°C/14d, and 4°C/28d OCAs did not vary compared to Non-Op, but BS/TV was lower. (2) OCAs contained "basal" cysts, localized to deeper regions, some "subchondral" cysts, localized near the bone-cartilage interface, and some ScB channels. TB surrounding basal cysts exhibited higher BV/TV than Non-Op. (3) Basal cysts occurred (a) in isolation, (b) with subchondral cysts and ScB channels, (c) with ScB channels, or (d) with subchondral cysts, ScB channels, and ScB erosion. Deterioration of cartilage gross morphology was strongly associated with abnormal μCT bone structure. Evidence of cartilage-bone communication following OCA repair may favor fluid intrusion as a mechanism for subchondral cyst formation, while bone resorption at the graft-host interface without affecting overall bone and cartilage structure may favor bony contusion mechanism for basal cyst formation. These

  12. Cartilage Repair and Subchondral Bone Migration Using 3D Printing Osteochondral Composites: A One-Year-Period Study in Rabbit Trochlea

    PubMed Central

    Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; He, Jiankang; Jin, Zhongmin

    2014-01-01

    Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a “flow like” manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a “flow like” manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application. PMID:25177697

  13. Cartilage repair and subchondral bone migration using 3D printing osteochondral composites: a one-year-period study in rabbit trochlea.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; He, Jiankang; Jin, Zhongmin

    2014-01-01

    Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a "flow like" manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a "flow like" manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application. PMID:25177697

  14. Cartilage repair and subchondral bone migration using 3D printing osteochondral composites: a one-year-period study in rabbit trochlea.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; He, Jiankang; Jin, Zhongmin

    2014-01-01

    Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a "flow like" manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a "flow like" manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application.

  15. Bone Repair with Differentiated Osteoblasts from Adipose-derived Stem Cells in Hydroxyapatite/Tricalcium Phosphate In vivo

    PubMed Central

    Hashemibeni, Batool; Dehghani, Leila; Sadeghi, Farzaneh; Esfandiari, Ebrahim; Gorbani, Masood; Akhavan, Ali; Tahani, Soheil T.; Bahramian, Hamid; Goharian, Vahid

    2016-01-01

    Background: Recently, tissue engineering has developed approaches for repair and restoration of damaged skeletal system based on different scaffolds and cells. This study evaluated the ability of differentiated osteoblasts from adipose-derived stem cells (ADSCs) seeded into hydroxyapatite/tricalcium phosphate (HA-TCP) to repair bone. Methods: In this study, ADSCs of 6 canines were seeded in HA-TCP and differentiated into osteoblasts in osteogenic medium in vitro and bone markers evaluated by reverse transcription polymerase chain reaction (RT-PCR). Scanning electron microscopy (SEM) was applied for detection of cells in the pores of scaffold. HA-TCP with differentiated cells as the test group and without cells as the cell-free group were implanted in separate defected sites of canine's tibia. After 8 weeks, specimens were evaluated by histological, immunohistochemical methods, and densitometry test. The data were analyzed using the SPSS 18 version software. Results: The expression of Type I collagen and osteocalcin genes in differentiated cells were indicated by RT-PCR. SEM results revealed the adhesion of cells in scaffold pores. Formation of trabecular bone confirmed by histological sections that revealed the thickness of bone trabecular was more in the test group. Production of osteopontin in extracellular matrix was indicated in both groups. Densitometry method indicated that strength in the test group was similar to cell-free group and natural bone (P > 0.05). Conclusions: This research suggests that ADSCs-derived osteoblasts in HA-TCP could be used for bone tissue engineering and repairing. PMID:27141281

  16. Overexpression of PLAP-1 in bone marrow stromal cells inhibits the rat critical-size skull defect repair.

    PubMed

    Yu, Xijiao; Sun, Jing; Hu, Ying; Gao, Yan; Xiao, Changjie; Liu, Shuang; Li, Shu

    2015-06-01

    Periodontal ligament-associated protein-1 (PLAP-1) is an osteogenisis negative regulatory gene that inhibits the differentiation of rat bone marrow stromal cells (rBMSCs) into osteoblasts in vitro. The aim of this study was to verify whether PLAP-1 acted as an inhibitory factor of rBMSCs in rat critical-size skull defect repair in vivo. Six-week old male Wistar rats treated with a drill-hole injury were randomly assigned into five groups PLAP-1-transfected rBMSC group, empty vector-transfected rBMSC group, normal rBMSC group, collagen group and blank control group according to the treatment factors. Skull specimens were obtained at 8 weeks after surgery. X-ray examination, histological observation of hard tissue slices (HE, Masson staining and von Kossa staining), immunohistochemical staining were applied to evaluate the repair effects. X-ray examination showed that repair effect of the PLAP-1-transfected rBMSC group was significantly worse than that of the empty vector-transfected rBMSC group and normal rBMSC group. In HE staining, regenerated bone could only be observed in the partial defect area of the PLAP-1-transfected rBMSC group. However, new bone filled nearly the entire defects in the empty vector-transfected rBMSC group and normal rBMSC group. Mineralization of new bone in the two groups was significantly higher than that of the PLAP-1-transfected rBMSC group, according to Masson and von Kossa staining. Meanwhile, the transfected PLAP-1 gene worked well in vivo. Positive expression of PLAP-1 protein was only distributed in the newly formed bone of the PLAP-1-transfected rBMSC group, no positive staining was observed in the other four groups. Overexpression of PLAP-1 in rBMSCs inhibits new bone formation and mineralization in rat critical-size skull defects in vivo.

  17. Preparation, characterization, in vitro bioactivity, and cellular responses to a polyetheretherketone bioactive composite containing nanocalcium silicate for bone repair.

    PubMed

    Ma, Rui; Tang, Songchao; Tan, Honglue; Qian, Jun; Lin, Wentao; Wang, Yugang; Liu, Changsheng; Wei, Jie; Tang, Tingting

    2014-08-13

    In this study, a nanocalcium silicate (n-CS)/polyetheretherketone (PEEK) bioactive composite was prepared using a process of compounding and injection-molding. The mechanical properties, hydrophilicity, and in vitro bioactivity of the composite, as well as the cellular responses of MC3T3-E1 cells (attachment, proliferation, spreading, and differentiation) to the composite, were investigated. The results showed that the mechanical properties and hydrophilicity of the composites were significantly improved by the addition of n-CS to PEEK. In addition, an apatite-layer formed on the composite surface after immersion in simulated body fluid (SBF) for 7 days. In cell culture tests, the results revealed that the n-CS/PEEK composite significantly promoted cell attachment, proliferation, and spreading compared with PEEK or ultrahigh molecular weight polyethylene (UHMWPE). Moreover, cells grown on the composite exhibited higher alkaline phosphatase (ALP) activity, more calcium nodule-formation, and higher expression levels of osteogenic differentiation-related genes than cells grown on PEEK or UHMWPE. These results indicated that the incorporation of n-CS to PEEK could greatly improve the bioactivity and biocompatibility of the composite. Thus, the n-CS/PEEK composite may be a promising bone repair material for use in orthopedic clinics.

  18. Preparation, characterization, in vitro bioactivity, and cellular responses to a polyetheretherketone bioactive composite containing nanocalcium silicate for bone repair.

    PubMed

    Ma, Rui; Tang, Songchao; Tan, Honglue; Qian, Jun; Lin, Wentao; Wang, Yugang; Liu, Changsheng; Wei, Jie; Tang, Tingting

    2014-08-13

    In this study, a nanocalcium silicate (n-CS)/polyetheretherketone (PEEK) bioactive composite was prepared using a process of compounding and injection-molding. The mechanical properties, hydrophilicity, and in vitro bioactivity of the composite, as well as the cellular responses of MC3T3-E1 cells (attachment, proliferation, spreading, and differentiation) to the composite, were investigated. The results showed that the mechanical properties and hydrophilicity of the composites were significantly improved by the addition of n-CS to PEEK. In addition, an apatite-layer formed on the composite surface after immersion in simulated body fluid (SBF) for 7 days. In cell culture tests, the results revealed that the n-CS/PEEK composite significantly promoted cell attachment, proliferation, and spreading compared with PEEK or ultrahigh molecular weight polyethylene (UHMWPE). Moreover, cells grown on the composite exhibited higher alkaline phosphatase (ALP) activity, more calcium nodule-formation, and higher expression levels of osteogenic differentiation-related genes than cells grown on PEEK or UHMWPE. These results indicated that the incorporation of n-CS to PEEK could greatly improve the bioactivity and biocompatibility of the composite. Thus, the n-CS/PEEK composite may be a promising bone repair material for use in orthopedic clinics. PMID:25013988

  19. RESTORING A DAMAGED 16-YEAR -OLD INSULATING POLYMER CONCRETE DIKE OVERLAY: REPAIR MATERIALS AND TECHNOLOGIES.

    SciTech Connect

    SUGAMA,T.

    2007-01-01

    The objective of this program was to design and formulate organic polymer-based material systems suitable for repairing and restoring the overlay panels of insulating lightweight polymer concrete (ILPC) from the concrete floor and slope wall of a dike at KeySpan liquefied natural gas (LNG) facility in Greenpoint, Brooklyn, NY, just over sixteen years ago. It also included undertaking a small-scale field demonstration to ensure that the commercial repairing technologies were applicable to the designed and formulated materials.

  20. Bone Cysts After Osteochondral Allograft Repair of Cartilage Defects in Goats Suggest Abnormal Interaction Between Subchondral Bone and Overlying Synovial Joint Tissues

    PubMed Central

    Pallante-Kichura, Andrea L.; Cory, Esther; Bugbee, William D.; Sah, Robert L.

    2013-01-01

    The efficacy of osteochondral allografts (OCA) may be affected by osseous support of the articular cartilage, and thus affected by bone healing and remodeling in the OCA and surrounding host. Bone cysts, and their communication pathways, may be present in various locations after OCA insertion and reflect distinct pathogenic mechanisms. Previously, we analyzed the effect of OCA storage (FRESH, 4°C/14d, 4°C/28d, FROZEN) on cartilage quality in fifteen adult goats after 12 months in vivo. The objectives of this study were to further analyze OCA and contralateral non-operated (Non-Op) CONTROLS from the medial femoral condyle to (1) determine the effect of OCA storage on local subchondral (ScB) and trabecular (TB) bone structure, (2) characterize the location and structure of bone cysts and channels, and (3) assess the relationship between cartilage and bone properties. (1) Overall bone structure after OCA was altered compared to Non-Op, with OCA samples displaying bone cysts, ScB channels, and ScB roughening. ScB BV/TV in FROZEN OCA was lower than Non-Op and other OCA. TB BV/TV in FRESH, 4°C/14d, and 4°C/28d OCA did not vary compared to Non-Op, but BS/TV was lower. (2) OCA contained “basal” cysts, localized to deeper regions, some “subchondral” cysts, localized near the bone-cartilage interface, and some ScB channels. TB surrounding basal cysts exhibited higher BV/TV than Non-Op. (3) Basal cysts occurred (a) in isolation, (b) with subchondral cysts and ScB channels, (c) with ScB channels, or (d) with subchondral cysts, ScB channels, and ScB erosion. Deterioration of cartilage gross morphology was strongly associated with abnormal μCT bone structure. Evidence of cartilage-bone communication following OCA repair may favor fluid intrusion as a mechanism for subchondral cyst formation, while bone resorption at the graft-host interface without affecting overall bone and cartilage structure may favor bony contusion mechanism for basal cyst formation. These

  1. Auto Body Repair--Student Material. Competency Based Education Curriculum.

    ERIC Educational Resources Information Center

    Radio Corp. of America, Palo Alto, CA. Education Systems.

    This student manual is part of the competency based education curriculum for students training in auto body repair. The manual contains learning modules in eight areas; (1) occupational information, (2) trim and accessories, (3) glass, (4) painting and refinishing, (5) metal work, (6) body alignment, (7) frame work, and (8) estimating. Within each…

  2. Bone marrow cells for cardiac regeneration and repair: current status and issues.

    PubMed

    Haider, Husnain Kh

    2006-07-01

    Extensive studies in experimental animal heart models and patients have shown the promise of bone marrow cell (BMC) transplantation as an alternative strategy to the conventional treatment modalities for cardiac repair. 'Stemness' of BMC to adopt cardiac phenotype, their potential as carriers of exogenous therapeutic genes and an inherent ability to express growth factors and cytokines to exert paracrine effects have been especially focused until recently. These findings suggest that locally delivered BMCs are capable of regenerating de novo myocardium. Others have shown that extensive neovascularization due to paracrine effects of the engrafted cells resulted in improved regional blood flow and reduced infarct size. Despite initial success, there are multiple fundamental issues that remain contentious. Indeed, resolving these issues will optimize future heart cell therapy protocols to achieve better prognosis in the clinical settings. This review is a concise, in-depth and critical appreciation of the role of BMCs in heart cell therapy and builds a conceptual framework to elaborate their significance as a possible source of donor cells. Moreover, it discusses the current status of BMC transplantation as a clinical modality and the relevant issues confronting this approach in light of the published data with clinical relevance.

  3. A prospective study on the effectiveness of newly developed autogenous tooth bone graft material for sinus bone graft procedure

    PubMed Central

    Jun, Sang-Ho; Ahn, Jin-Soo; Lee, Jae-Il; Ahn, Kyo-Jin; Yun, Pil-Young

    2014-01-01

    PURPOSE The purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure. MATERIALS AND METHODS The patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site. RESULTS In CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness (0.07 µm in Bio-Oss group Vs. 0.08 µm in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness (8.35 µm in Bio-Oss group Vs. 13.12 µm in AutoBT group) (P=.025). CONCLUSION AutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure. PMID:25551014

  4. The effect of deferoxamine on angiogenesis and bone repair in steroid-induced osteonecrosis of rabbit femoral heads

    PubMed Central

    Li, Jia; Fan, Lihong; Yu, Zefeng; Dang, Xiaoqian

    2015-01-01

    In this study, we examined whether local deferoxamine (DFO) administration can promote angiogenesis and bone repair in steroid-induced osteonecrosis of the femoral head (ONFH). Steroid-induced ONFH was induced in 65 mature male New Zealand white rabbits by methylprednisolone in combination with lipopolysaccharide. Six weeks later, the rabbits received no treatment (model group, N = 15), bilateral core decompression (CD group, N = 20) or CD in combination with local DFO administration (DFO group, N = 20). Six weeks after the surgery, vascularization in the femoral head was evaluated by ink artery infusion angiography and immunohistochemical staining for von Willebrand Factor (vWF). Bone repair was assessed by histologic analysis and micro-computed tomography (micro-CT). Immunohistochemical staining was performed to analyze the expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1α (HIF-1α), bone morphogenetic protein-2 (BMP-2), and osteocalcin (OCN). Ink artery infusion angiography and microvessel analysis by immuohistochemical staining for vWF showed more blood vessels in the DFO group than other groups. The expression of HIF-1α, VEGF, BMP-2, and OCN, indicated by immunohistochemical staining, was higher in the DFO group compared with other groups. Micro-CT scanning results indicated that the DFO group had larger volume of newly formed bone than the CD group. This work indicated that local DFO administration improved angiogenesis and bone repair of early stage ONFH in rabbit model, and it may offer an efficient, economic, and simple therapy for early stage ONFH. PMID:25294892

  5. Adaptable Holders for Arc-Jet Screening Candidate Thermal Protection System Repair Materials

    NASA Technical Reports Server (NTRS)

    Riccio, Joe; Milhoan, Jim D.

    2010-01-01

    Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

  6. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    PubMed

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum.

  7. Dental repair material: a resin-modified glass-ionomer bioactive ionic resin-based composite.

    PubMed

    Croll, Theodore P; Berg, Joel H; Donly, Kevin J

    2015-01-01

    This report documents treatment and repair of three carious teeth that were restored with a new dental repair material that features the characteristics of both resin-modified glass-ionomer restorative cement (RMGI) and resin-based composite (RBC). The restorative products presented are reported by the manufacturer to be the first bioactive dental materials with an ionic resin matrix, a shock-absorbing resin component, and bioactive fillers that mimic the physical and chemical properties of natural teeth. The restorative material and base/liner, which feature three hardening mechanisms, could prove to be a notable advancement in the adhesive dentistry restorative materials continuum. PMID:25822408

  8. Engineered cell-free scaffold with two-stage delivery of miRNA-26a for bone repair

    PubMed Central

    Paquet, Joseph; Moya, Adrien; Bensidhoum, Morad

    2016-01-01

    The treatment of non-unions and bone defects is a major challenge. In these situations, autologous bone is the preferred treatment but has several serious limitations. Treatment alternatives including the use of calcium-based scaffolds alone or associated with either growth factors or stem cells have therefore been developed, or are under development, to overcome these shortcomings. Each of these are, however, associated with their own drawbacks, such as the lack of sustained/controlled delivery system for growth factors and poor cell survival and engraftment for stem cells. MicroRNAs (miRNAs), a class of small noncoding RNAs fine-tune the expression of as much as 30% of all mammalian protein-encoding genes. For instance, miRNA26a is able to promote the repair of critical-size calvarial bone defects. Yet, the clinical application of these fascinating molecules has been hampered by a lack of appropriate delivery systems. In an elegant report entitled cell-free 3D scaffold with two-stage delivery of miRNA-26a to regenerate critical-sized bone defects, Zhang et al. 2016, developped a non-viral vector with high affinity to miR-26a that ensured its efficient delivery in bone defects. Engineered scaffolds were able to induce the regeneration of calvarial bone defects in healthy and osteoporotic mice. Taken together, these data pave the way for the development of advanced bone substitutes that at least will match, and preferably supersede, the clinical efficiency of autologous bone grafts. However, the transfer from the bench to the bedside of such scaffolds requires further investigations including (I) a better understanding of the underlying biological mechanisms involved in bone formation via miRNA26a; (II) evidences of polymer scaffold biocompatibility upon its complete degradation; and (III) demonstration of the engineered scaffold functionality in defects of clinically relevant volume. PMID:27294100

  9. Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone.

    PubMed

    Rivera, César; Monsalve, Francisco; Salas, Juan; Morán, Andrea; Suazo, Iván

    2013-12-01

    Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H2O (n=3), distilled water without the drug and alveolar bone damage; BD/H2O/PRP (n=3), BD and PRP; BD/H2O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects.

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

    PubMed Central

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

    2016-01-01

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

  11. The use of SHP-2 gene transduced bone marrow mesenchymal stem cells to promote osteogenic differentiation and bone defect repair in rat.

    PubMed

    Fan, Dapeng; Liu, Shen; Jiang, Shichao; Li, Zhiwei; Mo, Xiumei; Ruan, Hongjiang; Zou, Gang-Ming; Fan, Cunyi

    2016-08-01

    Bone tissue engineering is a promising approach for bone regeneration, in which growth factors play an important role. The tyrosine phosphatase Src-homology region 2-containing protein tyrosine phosphatase 2 (SHP2), encoded by the PTPN11 gene, is essential for the differentiation, proliferation and metabolism of osteoblasts. However, SHP-2 has never been systematically studied for its effect in osteogenesis. We predicted that overexpression of SHP-2 could promote bone marrow-derived mesenchymal stem cell (BMSC)osteogenic differentiation and SHP-2 transduced BMSCs could enhance new bone formation, determined using the following study groups: (1) BMSCs transduced with SHP-2 and induced with osteoblast-inducing liquid (BMSCs/SHP-2/OL); (2) BMSCs transduced with SHP-2 (BMSCs/-SHP-2); (3) BMSCs induced with osteoblast-inducing liquid (BMSCs/OL) and (4) pure BMSCs. Cells were assessed for osteogenic differentiation by quantitative real-time polymerase chain reaction analysis, western blot analysis, alkaline phosphatase activity and alizarin red S staining. For in vivo assessment, cells were combined with beta-tricalcium phosphate scaffolds and transplanted into rat calvarial defects for 8 weeks. Following euthanasia, skull samples were explanted for osteogenic evaluation, including micro-computed tomography measurement, histology and immunohistochemistry staining. SHP-2 and upregulation of its gene promoted BMSC osteogenic differentiation and therefore represents a potential new therapeutic approach to bone repair. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1871-1881, 2016.

  12. A novel hyperthermia treatment for bone metastases using magnetic materials.

    PubMed

    Matsumine, Akihiko; Takegami, Kenji; Asanuma, Kunihiro; Matsubara, Takao; Nakamura, Tomoki; Uchida, Atsumasa; Sudo, Akihiro

    2011-04-01

    Patients with bone metastases in the extremities sometimes require surgical intervention to prevent deterioration of quality of life due to a pathological fracture. The use of localized radiotherapy combined with surgical reinforcement has been a gold standard for the treatment of bone metastases. However, radiotherapy sometimes induces soft tissue damage, including muscle induration and joint contracture. Moreover, cancer cells are not always radiosensitive. Hyperthermia has been studied since the 1940s using an experimental animal model to treat various types of advanced cancer, and studies have now reached the stage of clinical application, especially in conjunction with radiotherapy or chemotherapy. Nevertheless, bone metastases have several special properties which discourage oncologists from developing hyperthermic therapeutic strategies. First, the bone is located deep in the body, and has low thermal conductivity due to the thickness of cortical bone and the highly vascularized medulla. To address these issues, we developed new hyperthermic strategies which generate heat using magnetic materials under an alternating electromagnetic field, and started clinical application of this treatment modality. The purpose of this review is to summarize the latest studies on hyperthermic treatment in the field of musculoskeletal tumors, and to introduce the treatment strategy employing our novel hyperthermia approach.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

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

    PubMed

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

    2010-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2006-08-01

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

  16. Effects of coffee intake and intraperitoneal caffeine on bone repair process--a histologic and histometric study.

    PubMed

    Macedo, Rander Moreira; Brentegani, Luiz Guilherme; Lacerda, Suzie Aparecida de

    2015-01-01

    Studies have suggested that caffeine acts on bone promoting an increase of calcium excretion, inhibition of osteoblast proliferation and delay in tissue repair process, raising the risk of fractures, osteoporosis, periodontal disease and affecting the success of bone reconstructive procedures. The aim of this study was to analyze histomorphometrically the process of alveolar bone healing after tooth extraction in rats subjected to daily intake of boiled coffee or intraperitoneal administration of caffeine. Forty-five male rats were divided according to the treatment in Control group (C); Coffee group (CO) - treated with coffee since birth; and Caffeine (CAF) - intraperitoneal injection of aqueous solution of caffeine 1.5% (0.2 mL/100g body weight) for 30 days. When weighing between 250-300 g they were anesthetized, subjected to extraction of the maxillary right incisor, and euthanized 7, 21 and 42 days after surgery for histological assessments of bone volume and the quality of formed bone in the dental socket. The qualitative results demonstrated larger amounts of blood clot and immature bone in animals under treatment of pure caffeine compared to coffee and control. Histometric analysis revealed that coffee treatment led to a 40% drop in bone formation, and caffeine a 60% drop in comparison to control animals (ANOVA p≤0.01). It was concluded that both the daily ingestion of coffee and the intraperitoneal administration of caffeine in rats delayed the alveolar bone reparative process after tooth extraction, and this effect was more aggressive when pure caffeine was used. PMID:25831110

  17. Rapid adhesive bonding and field repair of aerospace materials

    NASA Technical Reports Server (NTRS)

    Stein, B. A.

    1985-01-01

    Adhesive bonding in the aerospace industry typically utilizes autoclaves or presses which have considerable thermal mass. As a consequence, the rates of heatup and cooldown of the bonded parts are limited and the total time and cost of the bonding process are often relatively high. Many of the adhesives themselves do not inherently require long processing times. Bonding could be performed rapidly if the heat was concentrated in the bond lines or at least in the adherends. Rapid Adhesive Bonding concepts are developed to utilize induction heating techniques to provide heat directly to the bond line and/or adherends without heating the entire structure, supports, and fixtures of a bonding assembly. Bonding times for specimens can be cut by a factor of 10 to 100 compared to standard press or autoclave bonding. The development of Rapid Adhesive Bonding for lap shear specimens (per ASTM D1002 and D3163), for aerospace panel or component bonding, and for field repair needs of metallic and advanced fiber reinforced polymeric-matrix composite structures is reviewed. Equipment and procedures are described for bonding and repairing thin sheets, simple geometries, and honeycomb core panels.

  18. Use of a biological reactor and platelet-rich plasma for the construction of tissue-engineered bone to repair articular cartilage defects

    PubMed Central

    Li, Huibo; Sun, Shui; Liu, Haili; Chen, Hua; Rong, Xin; Lou, Jigang; Yang, Yunbei; Yang, Yi; Liu, Hao

    2016-01-01

    Articular cartilage defects are a major clinical burden worldwide. Current methods to repair bone defects include bone autografts, allografts and external fixation. In recent years, the repair of bone defects by tissue engineering has emerged as a promising approach. The present study aimed to assess a novel method using a biological reactor with platelet-rich plasma to construct tissue-engineered bone. Beagle bone marrow mesenchymal stem cells (BMSCs) were isolated and differentiated into osteoblasts and chondroblasts using platelet-rich plasma and tricalcium phosphate scaffolds cultured in a bioreactor for 3 weeks. The cell scaffold composites were examined by scanning electron microscopy (SEM) and implanted into beagles with articular cartilage defects. The expression of osteogenic markers, alkaline phosphatase and bone γ-carboxyglutamate protein (BGLAP) were assessed using polymerase chain reaction after 3 months. Articular cartilage specimens were observed histologically. Adhesion and distribution of BMSCs on the β-tricalcium phosphate (β-TCP) scaffold were confirmed by SEM. Histological examination revealed that in vivo bone defects were largely repaired 12 weeks following implantation. The expression levels of alkaline phosphatase (ALP) and BGLAP in the experimental groups were significantly elevated compared with the negative controls. BMSCs may be optimum seed cells for tissue engineering in bone repair. Platelet-rich plasma (PRP) provides a rich source of cytokines to promote BMSC function. The β-TCP scaffold is advantageous for tissue engineering due to its biocompatibility and 3D structure that promotes cell adhesion, growth and differentiation. The tissue-engineered bone was constructed in a bioreactor using BMSCs, β-TCP scaffolds and PRP and displayed appropriate morphology and biological function. The present study provides an efficient method for the generation of tissue-engineered bone for cartilage repair, compared with previously used

  19. Bone marrow cell transcripts from Fanconi anaemia patients reveal in vivo alterations in mitochondrial, redox and DNA repair pathways.

    PubMed

    Pagano, Giovanni; Talamanca, Annarita Aiello; Castello, Giuseppe; d'Ischia, Marco; Pallardó, Federico V; Petrović, Sandra; Porto, Beatriz; Tiano, Luca; Zatterale, Adriana

    2013-08-01

    Fanconi anaemia (FA) is a genetic cancer predisposition disorder associated with cytogenetic instability, bone marrow failure and a pleiotropic cellular phenotype, including low thresholds of responses to oxidative stress, cross-linking agents and selected cytokines. This study was aimed at defining the scope of abnormalities in gene expression using the publicly available FA Transcriptome Consortium (FTC) database (Gene Expression Omnibus, 2009 and publicly available as GSE16334). We evaluated the data set that included transcriptomal analyses on RNA obtained from low-density bone marrow cells (BMC) from 20 patients with FA and 11 healthy volunteers, by seeking to identify changes in expression of over 22,000 genes, including a set of genes involved in: (i) bioenergetic pathways; (ii) antioxidant activities; (iii) response to stress and metal-chelating proteins; (iv) inflammation-related cytokines and (v) DNA repair. Ontological analysis of genes expressed at magnitudes of 1.5-fold or greater demonstrated significant suppression of genes in the categories of (i) energy metabolism; (ii) antioxidant activities; and (iii) stress and chelating proteins. Enhanced expression was found for 16 of 26 genes encoding inflammatory cytokines. A set of 20 of 21 transcripts for DNA repair activities were down-regulated; four of these transcripts related to type II topoisomerase. The data provide evidence for alterations in gene regulation of bioenergetic activities, redox-related activities, stress and metal-chelating proteins, and of some selected DNA repair activities in patients with FA.

  20. In vitro comparison of two different materials for the repair of urethan dimethacrylate denture bases

    PubMed Central

    Cilingir, Altug; Bilhan, Hakan; Sulun, Tonguc; Bozdag, Ergun; Sunbuloglu, Emin

    2013-01-01

    PURPOSE The purpose of this in vitro study was to investigate the flexural properties of a recently introduced urethane dimethacrylate denture base material (Eclipse) after being repaired with two different materials. MATERIALS AND METHODS Two repair groups and a control group consisting of 10 specimens each were generated. The ES group was repaired with auto-polymerizing polymer. The EE group was repaired with the Eclipse. The E group was left intact as a control group. A 3-point bending test device which was set to travel at a crosshead speed of 5 mm/min was used. Specimens were loaded until fracture occurred and the mean displacement, maximum load, flexural modulus and flexural strength values and standard deviations were calculated for each group and the data were statistically analyzed. The results were assessed at a significance level of P<.05. RESULTS The mean "displacement", "maximum load before fracture", "flexural strength" and "flexural modulus" rates of Group E were statistically significant higher than those of Groups ES and EE, but no significant difference (P>.05) was found between the mean values of Group ES and EE. There was a statistically significant positive relation (P<.01) between the displacement and maximum load of Group ES (99.5%), Group EE (94.3%) and Group E (84.4%). CONCLUSION The more economic and commonly used self-curing acrylic resin can be recommended as an alternative repair material for Eclipse denture bases. PMID:24353876

  1. Repair bond strength of dual-cured resin composite core buildup materials.

    PubMed

    El-Deeb, Heba A; Ghalab, Radwa M; Elsayed Akah, Mai M; Mobarak, Enas H

    2016-03-01

    The reparability of dual-cured resin composite core buildup materials using a light-cured one following one week or three months storage, prior to repair was evaluated. Two different dual-cured resin composites; Cosmecore™ DC automix and Clearfil™ DC automix core buildup materials and a light-cured nanofilled resin composite; Filtek™ Z350 XT were used. Substrate specimens were prepared (n = 12/each substrate material) and stored in artificial saliva at 37 °C either for one week or three months. Afterward, all specimens were ground flat, etched using Scotchbond™ phosphoric acid etchant and received Single Bond Universal adhesive system according to the manufacturers' instructions. The light-cured nanofilled resin composite (Filtek™ Z350 XT) was used as a repair material buildup. To determine the cohesive strength of each solid substrate material, additional specimens from each core material (n = 12) were prepared and stored for the same periods. Five sticks (0.8 ± 0.01 mm(2)) were obtained from each specimen (30 sticks/group) for microtensile bond strength (μTBS) testing. Modes of failure were also determined. Two-way ANOVA revealed a significant effect for the core materials but not for the storage periods or their interaction. After one week, dual-cured resin composite core buildup materials (Cosmecore™ DC and Clearfil™ DC) achieved significantly higher repair μTBS than the light-cured nanofilled resin composite (Filtek™ Z350 XT). However, Clearfil™ DC revealed the highest value, then Cosmecore™ DC and Filtek™ Z350 XT, following storage for 3-month. Repair strength values recovered 64-86% of the cohesive strengths of solid substrate materials. The predominant mode of failure was the mixed type. Dual-cured resin composite core buildup materials revealed acceptable repair bond strength values even after 3-month storage. PMID:26966567

  2. Repair bond strength of dual-cured resin composite core buildup materials.

    PubMed

    El-Deeb, Heba A; Ghalab, Radwa M; Elsayed Akah, Mai M; Mobarak, Enas H

    2016-03-01

    The reparability of dual-cured resin composite core buildup materials using a light-cured one following one week or three months storage, prior to repair was evaluated. Two different dual-cured resin composites; Cosmecore™ DC automix and Clearfil™ DC automix core buildup materials and a light-cured nanofilled resin composite; Filtek™ Z350 XT were used. Substrate specimens were prepared (n = 12/each substrate material) and stored in artificial saliva at 37 °C either for one week or three months. Afterward, all specimens were ground flat, etched using Scotchbond™ phosphoric acid etchant and received Single Bond Universal adhesive system according to the manufacturers' instructions. The light-cured nanofilled resin composite (Filtek™ Z350 XT) was used as a repair material buildup. To determine the cohesive strength of each solid substrate material, additional specimens from each core material (n = 12) were prepared and stored for the same periods. Five sticks (0.8 ± 0.01 mm(2)) were obtained from each specimen (30 sticks/group) for microtensile bond strength (μTBS) testing. Modes of failure were also determined. Two-way ANOVA revealed a significant effect for the core materials but not for the storage periods or their interaction. After one week, dual-cured resin composite core buildup materials (Cosmecore™ DC and Clearfil™ DC) achieved significantly higher repair μTBS than the light-cured nanofilled resin composite (Filtek™ Z350 XT). However, Clearfil™ DC revealed the highest value, then Cosmecore™ DC and Filtek™ Z350 XT, following storage for 3-month. Repair strength values recovered 64-86% of the cohesive strengths of solid substrate materials. The predominant mode of failure was the mixed type. Dual-cured resin composite core buildup materials revealed acceptable repair bond strength values even after 3-month storage.

  3. Osteodifferentiated mesenchymal stem cells from bone marrow and adipose tissue express HLA-G and display immunomodulatory properties in HLA-mismatched settings: implications in bone repair therapy.

    PubMed

    Montespan, Florent; Deschaseaux, Frédéric; Sensébé, Luc; Carosella, Edgardo D; Rouas-Freiss, Nathalie

    2014-01-01

    Mesenchymal stem cells (MSCs) are multipotent cells that can be obtained from several sources such as bone marrow and adipose tissue. Depending on the culture conditions, they can differentiate into osteoblasts, chondroblasts, adipocytes, or neurons. In this regard, they constitute promising candidates for cell-based therapy aimed at repairing damaged tissues. In addition, MSCs display immunomodulatory properties through the expression of soluble factors including HLA-G. We here analyse both immunogenicity and immunosuppressive capacity of MSCs derived from bone marrow and adipose tissue before and after osteodifferentiation. Results show that HLA-G expression is maintained after osteodifferentiation and can be boosted in inflammatory conditions mimicked by the addition of IFN-γ and TNF-α. Both MSCs and osteodifferentiated MSCs are hypoimmunogenic and exert immunomodulatory properties in HLA-mismatched settings as they suppress T cell alloproliferation in mixed lymphocyte reactions. Finally, addition of biomaterials that stimulate bone tissue formation did not modify MSC immune properties. As MSCs combine both abilities of osteoregeneration and immunomodulation, they may be considered as allogenic sources for the treatment of bone defects.

  4. Novel hybrid materials for preparation of bone tissue engineering scaffolds.

    PubMed

    Lewandowska-Łańcucka, Joanna; Fiejdasz, Sylwia; Rodzik, Łucja; Łatkiewicz, Anna; Nowakowska, Maria

    2015-09-01

    The organic-inorganic hybrid systems based on biopolymer hydrogels with dispersed silica nanoparticles were obtained and characterized in terms of their physicochemical properties, cytocompatibility and bioactivity. The hybrid materials were prepared in a form of collagen and collagen-chitosan sols to which the silica nanoparticles of two different sizes were incorporated. The ability of these materials to undergo in situ gelation under physiological temperature was assessed by microviscosity and gelation time determination based on steady-state fluorescence anisotropy measurements. The effect of silica nanoparticles addition on the physicochemical properties (surface wettability, swellability) of hybrid materials was analyzed and compared with those characteristic for pristine collagen and collagen-chitosan hydrogels. Biological studies indicate that surface wettability determined in terms of contact angle for all of the hybrids prepared is optimal and thus can provide satisfactory adhesion of fibroblasts. Cytotoxicity test results showed high metabolic activity of mouse as well as human fibroblast cell lines cultured on hybrid materials. The composition of hybrids was optimized in terms of concentration of silica nanoparticles. The effect of silica on the formation of bone-like mineral structures on exposition to simulated body fluid was determined. SEM images revealed mineral phase formation not only at the surfaces but also in the whole volumes of all hybrid materials developed suggesting their usefulness for bone tissue engineering. EDS and FTIR analyses indicated that these mineral phases consist of apatite-like structures.

  5. Properties of carbon nanotube-dispersed Sr-hydroxyapatite injectable material for bone defects.

    PubMed

    Raucci, M G; Alvarez-Perez, M; Giugliano, D; Zeppetelli, S; Ambrosio, L

    2016-03-01

    This study concerns the synthesis of gel materials based on carbon nanotubes dispersed strontium-modified hydroxyapatite (Sr-HA) at different compositions obtained by sol-gel technology and their influence on human-bone-marrow-derived mesenchymal stem cells. Furthermore, an evaluation of the influence of nanotubes and Strontium on physico-chemical, morphological, rheological and biological properties of hydroxyapatite gel was also performed. Morphological analysis (scanning electron microscopy) shows a homogeneous distribution of modified nanotubes in the ceramic matrix improving the bioactive properties of materials. The biological investigations proved that Sr-HA/carbon nanotube gel containing 0-20 mol (%) of Sr showed no toxic effect and promote the expression of early and late markers of osteogenic differentiation in cell culture performed in basal medium without osteogenic factors. Finally, the SrHA/carbon nanotube gels could have a good potential application as filler in bone repair and regeneration and may be used in the osteoporotic disease treatment. PMID:26816652

  6. Properties of carbon nanotube-dispersed Sr-hydroxyapatite injectable material for bone defects

    PubMed Central

    Raucci, M. G.; Alvarez-Perez, M.; Giugliano, D.; Zeppetelli, S.; Ambrosio, L.

    2016-01-01

    This study concerns the synthesis of gel materials based on carbon nanotubes dispersed strontium-modified hydroxyapatite (Sr-HA) at different compositions obtained by sol–gel technology and their influence on human-bone-marrow-derived mesenchymal stem cells. Furthermore, an evaluation of the influence of nanotubes and Strontium on physico-chemical, morphological, rheological and biological properties of hydroxyapatite gel was also performed. Morphological analysis (scanning electron microscopy) shows a homogeneous distribution of modified nanotubes in the ceramic matrix improving the bioactive properties of materials. The biological investigations proved that Sr-HA/carbon nanotube gel containing 0–20 mol (%) of Sr showed no toxic effect and promote the expression of early and late markers of osteogenic differentiation in cell culture performed in basal medium without osteogenic factors. Finally, the SrHA/carbon nanotube gels could have a good potential application as filler in bone repair and regeneration and may be used in the osteoporotic disease treatment. PMID:26816652

  7. Nanostructured material formulated acrylic bone cements with enhanced drug release.

    PubMed

    Shen, Shou-Cang; Ng, Wai Kiong; Dong, Yuan-Cai; Ng, Junwei; Tan, Reginald Beng Hee

    2016-01-01

    To improve antibiotic properties, poly(methyl methacrylate) (PMMA)-based bone cements are formulated with antibiotic and nanostructured materials, such as hydroxyapatite (HAP) nanorods, carbon nanotubes (CNT) and mesoporous silica nanoparticles (MSN) as drug carriers. For nonporous HAP nanorods, the release of gentamicin (GTMC) is not obviously improved when the content of HAP is below 10%; while the high content of HAP shows detrimental to mechanical properties although the release of GTMC can be substantially increased. As a comparison, low content of hollow nanostructured CNT and MSN can enhance drug delivery efficiency. The presence of 5.3% of CNT in formulation can facilitate the release of more than 75% of GTMC in 80 days, however, its mechanical strength is seriously impaired. Among nanostructured drug carriers, antibiotic/MSN formulation can effectively improve drug delivery and exhibit well preserved mechanical properties. The hollow nanostructured materials are believed to build up nano-networks for antibiotic to diffuse from the bone cement matrix to surface and achieve sustained drug release. Based on MSN drug carrier in formulated bone cement, a binary delivery system is also investigated to release GTMC together with other antibiotics.

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

    PubMed

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

    2012-01-01

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

  9. Bacterial biosynthesis of a calcium phosphate bone-substitute material.

    PubMed

    Thackray, Aniac C; Sammons, Rachel L; Macaskie, Lynne E; Yong, Ping; Lugg, Harriet; Marquis, Peter M

    2004-04-01

    A species of Serratia bacteria produces nano-crystalline hydroxyapatite (HA) crystals by use of a cell-bound phosphatase enzyme, located both periplasmically and within extracellular polymeric materials. The enzyme functions in resting cells by cleaving glycerol-2-phosphate (G-2-P) to liberate free phosphate ions which combine with calcium in solution to produce a cell-bound calcium phosphate material. Bacteria grown as a biofilm on polyurethane reticulated foam cubes were challenged with calcium and G-2-P in a bioreactor to produce a 3-D porous bone-substitute material. The scaffold has 1 mm macropores and 1 microm micropores. XRD showed the crystallites to be 25-28 nm in size, resembling HA before sintering and beta-tricalcium phosphate (beta-TCP, whitlockite) after. When biofilm was grown on titanium discs and challenged with calcium and G-2-P, a calcium phosphate layer formed on the discs. Biomineralisation is therefore a potential route to production of precursor nanophase HA, which has the potential to improve strength. The scaffold material produced by this method could be used as a bone-filler or as an alternative method for coating implants with a layer of HA.

  10. Transplantation of allogenic chondrocytes with chitosan hydrogel-demineralized bone matrix hybrid scaffold to repair rabbit cartilage injury.

    PubMed

    Man, Zhentao; Hu, Xiaoqing; Liu, Zhenlong; Huang, Hongjie; Meng, Qingyang; Zhang, Xin; Dai, Linghui; Zhang, Jiying; Fu, Xin; Duan, Xiaoning; Zhou, Chunyan; Ao, Yingfang

    2016-11-01

    Cartilage tissue engineering is the hotspot of cartilage repair. The allogenic chondrocytes appear to be a promising source of seed cells in cartilage tissue engineering. In this study, we aimed to transplant allogenic chondrocytes with chitosan hydrogel (CS)-demineralized bone matrix (DBM) hybrid scaffold (CS/DBM) to repair rabbit cartilage injury with one-step operation. After the CS/DBM scaffold was successfully fabricated, it showed that the porous CS filled the large pores of DBM, which improved the distribution of seed cells in the CS/DBM scaffold. The allogenic chondrocytes at second passage were transplanted with different scaffolds to repair rabbit cartilage injury. Twenty-four weeks after surgery, the cartilage defect in the CS/DBM group was successfully filled as shown by MRI. Moreover, the histological score of CS/DBM group was significantly higher than that of the other groups. On the aspect of biomechanical property, the regenerated cartilage in the CS/DBM group were superior to those in the other groups as determined by nanoindentation. Meanwhile, no obvious inflammatory response was observed after the transplantation of allogenic chondrocytes at 24 weeks post-surgery. Furtherly, gene expression profile for cells within the repair tissue was compared with the allogenic chondrocytes before transplantation using Agilent microarray and RT-qPCR. The results showed that some genes beneficial to cartilage regeneration, such as BMP-7, HGF, and IGF-1, were upregulated one month after transplantation. Consequently, our study demonstrated that the transplantation of allogenic chondrocytes with CS/DBM scaffold successfully repaired rabbit cartilage injury with only one-step operation, thereby providing new insights into cartilage tissue engineering. PMID:27636153

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

    PubMed

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

    2011-12-01

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

  12. Suturing property of tough double network hydrogels for bio-repair materials

    NASA Astrophysics Data System (ADS)

    Na, Yang Ho; Oh, Hwa Yeon; Ahn, Young Ju; Han, Youngbae

    2015-02-01

    Cartilage and meniscal lesions have limited potential for spontaneous repair. Consequently, much effort has been made to develop methods for repairing such lesions. Double-network (DN) gels are new candidate-materials for repairing such lesions. They exhibit exceptional mechanical strength and toughness in spite of their high water content. In this study, we prepared highly tough DN hydrogels and investigated the mechanical properties related to clinical implant use. The mechanical properties such as Young's modulus and suture tear-out strength were measured for the artificial replacement. The results suggest that the suture property of DN hydrogels can be adjusted by controlling the crosslinking density and monomer concentration. Finite element method was also applied to these DN hydrogels in order to check whether the fracture strength of the material is enough to meet a medical purpose.

  13. Rapid bone repair in a patient with lung cancer metastases to the spine using a novel herbal medicine: A case report

    PubMed Central

    Pu, Rong; Zhao, Qianhong; Li, Zhimei; Zhang, Lingyan; Luo, Xiaolu; Zeren, Yangji; Yu, Cui; Li, Xianyong

    2016-01-01

    The prognosis of lung carcinoma with metastasis to the bone, particularly to the spine, is poor. Chemotherapy and radiotherapy are established treatments for metastatic bone disease, but their effectiveness is unsatisfactory and bone repair following their use is slow and difficult. Medicine prepared from herbal extracts may be an alternative treatment option. The present study discusses the case of a 59-year-old patient diagnosed with squamous cell lung cancer (T2N3M1) in which first-line chemotherapy using docetaxel plus cisplatin failed. Heavy multiple bone metastases were detected in the T9 vertebra and sixth left rib, resulting in a high risk of pathological fracture. Eastern Cooperative Oncology Group (ECOG) and numerical rating scale (NRS) scores of pain were 2 and 4, respectively. A second-line treatment was chosen consisting of biological intracontrol treatment (BICT) plus bisphosphonates administered over 40 days. BICT is a therapy involving the use of herbal extracts (including ginseng, herba agrimoniae, hairyvein agrimonia herb, white flower patrinia herb and arginine) and palliative care. A partial positive response was reached following use of this regimen, particularly with regard to bone repair. A computed tomography scan revealed a 90% reduction in the broken area of the rib cage and T9 vertebra. The bone repair was rapid and almost complete. In addition, growth of the primary tumor in the right pulmonary hilar and metastasis in the mediastinal lymph nodes were stabilized following treatment. ECOG and NRS scores were decreased to 1 and 0, respectively, leading to an improved quality of life. Based on these results, the present study suggests that this herbal medicine-based regimen promotes bone repair and inhibits tumor growth, with low toxicity. However, the mechanism by which herbal medicine promotes rapid bone repair is unclear. Further studies are required to determine whether cells in the tumor microenvironment are stimulated to undergo re

  14. Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone

    PubMed Central

    RIVERA, CÉSAR; MONSALVE, FRANCISCO; SALAS, JUAN; MORÁN, ANDREA; SUAZO, IVÁN

    2013-01-01

    Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H2O (n=3), distilled water without the drug and alveolar bone damage; BD/H2O/PRP (n=3), BD and PRP; BD/H2O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects. PMID:24250728

  15. Establishment of a preclinical ovine model for tibial segmental bone defect repair by applying bone tissue engineering strategies.

    PubMed

    Reichert, Johannes C; Epari, Devakara R; Wullschleger, Martin E; Saifzadeh, Siamak; Steck, Roland; Lienau, Jasmin; Sommerville, Scott; Dickinson, Ian C; Schütz, Michael A; Duda, Georg N; Hutmacher, Dietmar W

    2010-02-01

    Currently, well-established clinical therapeutic approaches for bone reconstruction are restricted to the transplantation of autografts and allografts, and the implantation of metal devices or ceramic-based implants to assist bone regeneration. Bone grafts possess osteoconductive and osteoinductive properties; however, they are limited in access and availability and associated with donor-site morbidity, hemorrhage, risk of infection, insufficient transplant integration, graft devitalization, and subsequent resorption resulting in decreased mechanical stability. As a result, recent research focuses on the development of alternative therapeutic concepts. The field of tissue engineering has emerged as an important approach to bone regeneration. However, bench-to-bedside translations are still infrequent as the process toward approval by regulatory bodies is protracted and costly, requiring both comprehensive in vitro and in vivo studies. The subsequent gap between research and clinical translation, hence, commercialization, is referred to as the "Valley of Death" and describes a large number of projects and/or ventures that are ceased due to a lack of funding during the transition from product/technology development to regulatory approval and subsequently commercialization. One of the greatest difficulties in bridging the Valley of Death is to develop good manufacturing processes and scalable designs and to apply these in preclinical studies. In this article, we describe part of the rationale and road map of how our multidisciplinary research team has approached the first steps to translate orthopedic bone engineering from bench to bedside by establishing a preclinical ovine critical-sized tibial segmental bone defect model, and we discuss our preliminary data relating to this decisive step.

  16. Injectable calcium phosphate with hydrogel fibers encapsulating induced pluripotent, dental pulp and bone marrow stem cells for bone repair.

    PubMed

    Wang, Lin; Zhang, Chi; Li, Chunyan; Weir, Michael D; Wang, Ping; Reynolds, Mark A; Zhao, Liang; Xu, Hockin H K

    2016-12-01

    Human induced pluripotent stem cell-derived mesenchymal stem cells (hiPSC-MSCs), dental pulp stem cells (hDPSCs) and bone marrow MSCs (hBMSCs) are exciting cell sources in regenerative medicine. However, there has been no report comparing hDPSCs, hBMSCs and hiPSC-MSCs for bone engineering in an injectable calcium phosphate cement (CPC) scaffold. The objectives of this study were to: (1) develop a novel injectable CPC containing hydrogel fibers encapsulating stem cells for bone engineering, and (2) compare cell viability, proliferation and osteogenic differentiation of hDPSCs, hiPSC-MSCs from bone marrow (BM-hiPSC-MSCs) and from foreskin (FS-hiPSC-MSCs), and hBMSCs in CPC for the first time. The results showed that the injection did not harm cell viability. The porosity of injectable CPC was 62%. All four types of cells proliferated and differentiated down the osteogenic lineage inside hydrogel fibers in CPC. hDPSCs, BM-hiPSC-MSCs, and hBMSCs exhibited high alkaline phosphatase, runt-related transcription factor, collagen I, and osteocalcin gene expressions. Cell-synthesized minerals increased with time (p<0.05), with no significant difference among hDPSCs, BM-hiPSC-MSCs and hBMSCs (p>0.1). Mineralization by hDPSCs, BM-hiPSC-MSCs, and hBMSCs inside CPC at 14d was 14-fold that at 1d. FS-hiPSC-MSCs were inferior in osteogenic differentiation compared to the other cells. In conclusion, hDPSCs, BM-hiPSC-MSCs and hBMSCs are similarly and highly promising for bone tissue engineering; however, FS-hiPSC-MSCs were relatively inferior in osteogenesis. The novel injectable CPC with cell-encapsulating hydrogel fibers may enhance bone regeneration in dental, craniofacial and orthopedic applications. PMID:27612810

  17. Establishment of a preclinical ovine model for tibial segmental bone defect repair by applying bone tissue engineering strategies.

    PubMed

    Reichert, Johannes C; Epari, Devakara R; Wullschleger, Martin E; Saifzadeh, Siamak; Steck, Roland; Lienau, Jasmin; Sommerville, Scott; Dickinson, Ian C; Schütz, Michael A; Duda, Georg N; Hutmacher, Dietmar W

    2010-02-01

    Currently, well-established clinical therapeutic approaches for bone reconstruction are restricted to the transplantation of autografts and allografts, and the implantation of metal devices or ceramic-based implants to assist bone regeneration. Bone grafts possess osteoconductive and osteoinductive properties; however, they are limited in access and availability and associated with donor-site morbidity, hemorrhage, risk of infection, insufficient transplant integration, graft devitalization, and subsequent resorption resulting in decreased mechanical stability. As a result, recent research focuses on the development of alternative therapeutic concepts. The field of tissue engineering has emerged as an important approach to bone regeneration. However, bench-to-bedside translations are still infrequent as the process toward approval by regulatory bodies is protracted and costly, requiring both comprehensive in vitro and in vivo studies. The subsequent gap between research and clinical translation, hence, commercialization, is referred to as the "Valley of Death" and describes a large number of projects and/or ventures that are ceased due to a lack of funding during the transition from product/technology development to regulatory approval and subsequently commercialization. One of the greatest difficulties in bridging the Valley of Death is to develop good manufacturing processes and scalable designs and to apply these in preclinical studies. In this article, we describe part of the rationale and road map of how our multidisciplinary research team has approached the first steps to translate orthopedic bone engineering from bench to bedside by establishing a preclinical ovine critical-sized tibial segmental bone defect model, and we discuss our preliminary data relating to this decisive step. PMID:19795978

  18. Injectable calcium phosphate with hydrogel fibers encapsulating induced pluripotent, dental pulp and bone marrow stem cells for bone repair.

    PubMed

    Wang, Lin; Zhang, Chi; Li, Chunyan; Weir, Michael D; Wang, Ping; Reynolds, Mark A; Zhao, Liang; Xu, Hockin H K

    2016-12-01

    Human induced pluripotent stem cell-derived mesenchymal stem cells (hiPSC-MSCs), dental pulp stem cells (hDPSCs) and bone marrow MSCs (hBMSCs) are exciting cell sources in regenerative medicine. However, there has been no report comparing hDPSCs, hBMSCs and hiPSC-MSCs for bone engineering in an injectable calcium phosphate cement (CPC) scaffold. The objectives of this study were to: (1) develop a novel injectable CPC containing hydrogel fibers encapsulating stem cells for bone engineering, and (2) compare cell viability, proliferation and osteogenic differentiation of hDPSCs, hiPSC-MSCs from bone marrow (BM-hiPSC-MSCs) and from foreskin (FS-hiPSC-MSCs), and hBMSCs in CPC for the first time. The results showed that the injection did not harm cell viability. The porosity of injectable CPC was 62%. All four types of cells proliferated and differentiated down the osteogenic lineage inside hydrogel fibers in CPC. hDPSCs, BM-hiPSC-MSCs, and hBMSCs exhibited high alkaline phosphatase, runt-related transcription factor, collagen I, and osteocalcin gene expressions. Cell-synthesized minerals increased with time (p<0.05), with no significant difference among hDPSCs, BM-hiPSC-MSCs and hBMSCs (p>0.1). Mineralization by hDPSCs, BM-hiPSC-MSCs, and hBMSCs inside CPC at 14d was 14-fold that at 1d. FS-hiPSC-MSCs were inferior in osteogenic differentiation compared to the other cells. In conclusion, hDPSCs, BM-hiPSC-MSCs and hBMSCs are similarly and highly promising for bone tissue engineering; however, FS-hiPSC-MSCs were relatively inferior in osteogenesis. The novel injectable CPC with cell-encapsulating hydrogel fibers may enhance bone regeneration in dental, craniofacial and orthopedic applications.

  19. Transplantation of human placenta-derived mesenchymal stem cells in a silk fibroin/hydroxyapatite scaffold improves bone repair in rabbits.

    PubMed

    Jin, Jun; Wang, Jun; Huang, Jian; Huang, Fang; Fu, Jianhong; Yang, Xinjing; Miao, Zongning

    2014-11-01

    The main requirements for successful tissue engineering of the bone are non-immunogenic cells with osteogenic potential and a porous biodegradable scaffold. The purpose of this study is to evaluate the potential of a silk fibroin/hydroxyapatite (SF/HA) porous material as a delivery vehicle for human placenta-derived mesenchymal stem cells (PMSCs) in a rabbit radius defect model. In this study, we randomly assigned 16 healthy adult New Zealand rabbits into two groups, subjected to transplantation with either SF/HA and PMSCs (experimental group) or SF/HA alone (control group). To evaluate fracture healing, we assessed the extent of graft absorption, the quantity of newly formed bone, and re-canalization of the cavitas medullaris using radiographic and histological tools. We performed flow cytometric analysis to characterize PMSCs, and found that while they express CD90, CD105 and CD73, they stain negative for HLA-DR and the hematopoietic cell surface markers CD34 and CD45. When PMSCs were exposed to osteogenic induction medium, they secreted calcium crystals that were identified by von Kossa staining. Furthermore, when seeded on the surface of SF/HA scaffold, they actively secreted extracellular matrix components. Here, we show, through radiographic and histological analyses, that fracture healing in the experimental group is significantly improved over the control group. This strongly suggests that transplantation of human PMSCs grown in an SF/HA scaffold into injured radius segmental bone in rabbits, can markedly enhance tissue repair. Our finding provides evidence supporting the utility of human placenta as a potential source of stem cells for bone tissue engineering.

  20. Acellular allogeneic nerve grafting combined with bone marrow mesenchymal stem cell transplantation for the repair of long-segment sciatic nerve defects: biomechanics and validation of mathematical models

    PubMed Central

    Li, Ya-jun; Zhao, Bao-lin; Lv, Hao-ze; Qin, Zhi-gang; Luo, Min

    2016-01-01

    We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects. To test this, we established rabbit models of 30 mm sciatic nerve defects, and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells. We compared the tensile properties, electrophysiological function and morphology of the damaged nerve in each group. Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell transplantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone, and produced similar results to those observed with the autograft. These findings confirm that a chemically extracted acellular allogeneic nerve graft combined with transplantation of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects. PMID:27651781

  1. Acellular allogeneic nerve grafting combined with bone marrow mesenchymal stem cell transplantation for the repair of long-segment sciatic nerve defects: biomechanics and validation of mathematical models

    PubMed Central

    Li, Ya-jun; Zhao, Bao-lin; Lv, Hao-ze; Qin, Zhi-gang; Luo, Min

    2016-01-01

    We hypothesized that a chemically extracted acellular allogeneic nerve graft used in combination with bone marrow mesenchymal stem cell transplantation would be an effective treatment for long-segment sciatic nerve defects. To test this, we established rabbit models of 30 mm sciatic nerve defects, and treated them using either an autograft or a chemically decellularized allogeneic nerve graft with or without simultaneous transplantation of bone marrow mesenchymal stem cells. We compared the tensile properties, electrophysiological function and morphology of the damaged nerve in each group. Sciatic nerves repaired by the allogeneic nerve graft combined with stem cell transplantation showed better recovery than those repaired by the acellular allogeneic nerve graft alone, and produced similar results to those observed with the autograft. These findings confirm that a chemically extracted acellular allogeneic nerve graft combined with transplantation of bone marrow mesenchymal stem cells is an effective method of repairing long-segment sciatic nerve defects.

  2. Hard tissue regeneration using bone substitutes: an update on innovations in materials.

    PubMed

    Sarkar, Swapan Kumar; Lee, Byong Taek

    2015-05-01

    Bone is a unique organ composed of mineralized hard tissue, unlike any other body part. The unique manner in which bone can constantly undergo self-remodeling has created interesting clinical approaches to the healing of damaged bone. Healing of large bone defects is achieved using implant materials that gradually integrate with the body after healing is completed. Such strategies require a multidisciplinary approach by material scientists, biological scientists, and clinicians. Development of materials for bone healing and exploration of the interactions thereof with the body are active research areas. In this review, we explore ongoing developments in the creation of materials for regenerating hard tissues. PMID:25995658

  3. Hard tissue regeneration using bone substitutes: an update on innovations in materials.

    PubMed

    Sarkar, Swapan Kumar; Lee, Byong Taek

    2015-05-01

    Bone is a unique organ composed of mineralized hard tissue, unlike any other body part. The unique manner in which bone can constantly undergo self-remodeling has created interesting clinical approaches to the healing of damaged bone. Healing of large bone defects is achieved using implant materials that gradually integrate with the body after healing is completed. Such strategies require a multidisciplinary approach by material scientists, biological scientists, and clinicians. Development of materials for bone healing and exploration of the interactions thereof with the body are active research areas. In this review, we explore ongoing developments in the creation of materials for regenerating hard tissues.

  4. Hard tissue regeneration using bone substitutes: an update on innovations in materials

    PubMed Central

    Sarkar, Swapan Kumar

    2015-01-01

    Bone is a unique organ composed of mineralized hard tissue, unlike any other body part. The unique manner in which bone can constantly undergo self-remodeling has created interesting clinical approaches to the healing of damaged bone. Healing of large bone defects is achieved using implant materials that gradually integrate with the body after healing is completed. Such strategies require a multidisciplinary approach by material scientists, biological scientists, and clinicians. Development of materials for bone healing and exploration of the interactions thereof with the body are active research areas. In this review, we explore ongoing developments in the creation of materials for regenerating hard tissues. PMID:25995658

  5. Airframe Repair Specialist, 2-3. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    These military-developed curriculum materials consist of five volumes of individualized, self-paced training manuals for use by those studying to be airframe repair technicians. Covered in the individual volumes are the following topics: fundamentals of organization and management (ground safety, aircraft ground safety, and aerospace and power…

  6. Introduction to Metal Bonded Repair, 13-4. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Air Training Command, Randolph AFB, TX.

    These instructor materials and student study guide for a secondary/postsecondary level course in metal-bonded repair comprise one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. The purpose stated for the course is to train students in the…

  7. Geomechanical Modeling to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Gomez, S. P.; Sobolik, S. R.; Matteo, E. N.; Dewers, T. A.; Taha, M. R.; Stormont, J. C.

    2013-12-01

    A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. For the DOE-NETL project 'Wellbore Seal Repair Using Nanocomposite Materials,' we are especially interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Building on existing thermo-hydro-mechanical (THM) finite element modeling of wellbore casings subject to significant tensile and shear loads, we advance a conceptual and numerical methodology to assess responses of annulus cement and casing. Bench-scale models complement bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. Field scale models use the stratigraphy from a pilot CO2 injection operation to estimate the necessary mechanical properties needed for a successful repair material. We report on approaches used for adapting existing wellbore models and share preliminary results of field scale models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: 2013-6241A.

  8. [Determinants of bone quality and strength independent of bone remodeling].

    PubMed

    Saito, Mitsuru; Marumo, Keishi

    2016-01-01

    Bone mineral density(BMD)and bone microstructure are regulated mainly by bone remodeling. In contrast, bone collagen enzymatic immature and mature cross-links and advanced glycation end products such as pentosidine and carboxyl methyl lysine are affected by various factors. Aging bone tissue is repaired in the process of bone remodeling. However, deterioration of bone material properties markedly advances due to increases in oxidative stress, glycation stress, reactive oxygen species, carbonyl stress associated with aging and reduced sex hormone levels, and glucocorticoid use. To improve bone material properties in osteoporosis, we should use different drug (Saito M, Calcif Tissue Int, REVIEW, 97;242-261, 2015). In this review, we summarized determinants of bone quality and strength independent of bone remodeling. PMID:26728528

  9. Adenovirus-mediated bone morphogenetic protein-2 gene transfection of bone marrow mesenchymal stem cells combined with nano-hydroxyapatite to construct bone graft material in vitro.

    PubMed

    Li, W C; Wang, D P; Li, L J; Zhu, W M; Zeng, Y J

    2013-04-01

    To study the adhesion, proliferation and expression of bone marrow mesenchymal stem cells (BMSCs) on nano-hydroxyapatite (Nano-HA) bone graft material after transfection of adenovirus-mediated human bone morphogenetic protein-2 expression vector (Ad-BMP-2). BMSCs were transfected using Ad-BMP-2. Immunohistochemistry and Western blot were used to detect BMP-2 expression in transfected cells. After transfection, BMP-2 protein was highly expressed in BMSCs; MTT test assay showed that the Nano-HA bone graft material could not inhibit in vitro proliferation of BMSCs. Ad-BMP-2-transfected BMSCs are well biocompatible with Nano-HA bone graft material, the transfected cells in material can secrete BMP-2 stably for a long time.

  10. Chitosan-poly(butylene succinate) scaffolds and human bone marrow stromal cells induce bone repair in a mouse calvaria model.

    PubMed

    Costa-Pinto, A R; Correlo, V M; Sol, P C; Bhattacharya, M; Srouji, S; Livne, E; Reis, R L; Neves, N M

    2012-01-01

    Tissue engineering sustains the need of a three-dimensional (3D) scaffold to promote the regeneration of tissues in volume. Usually, scaffolds are seeded with an adequate cell population, allowing their growth and maturation upon implantation in vivo. Previous studies obtained by our group evidenced significant growth patterns and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) when seeded and cultured on melt-based porous chitosan fibre mesh scaffolds (cell constructs). Therefore, it is crucial to test the in vivo performance of these in vitro 3D cell constructs. In this study, chitosan-based scaffolds were seeded and cultured in vitro with hBMSCs for 3 weeks under osteogenic stimulation conditions and analysed for cell adhesion, proliferation and differentiation. Implantation of 2 weeks precultured cell constructs in osteogenic culture conditions was performed into critical cranial size defects in nude mice. The objective of this study was to verify the scaffold integration and new bone formation. At 8 weeks of implantation, scaffolds were harvested and prepared for micro-computed tomography (µCT) analysis. Retrieved implants showed good integration with the surrounding tissue and significant bone formation, more evident for the scaffolds cultured and implanted with human cells. The results of this work demonstrated that chitosan-based scaffolds, besides supporting in vitro proliferation and osteogenic differentiation of hBMSCs, induced bone formation in vivo. Thus, their osteogenic potential in orthotopic location in immunodeficient mice was validated, evidencing good prospects for their use in bone tissue-engineering therapies.

  11. Guided bone regeneration using an allograft material: review and case presentations.

    PubMed

    Bhola, Monish; Kinaia, Bassam M; Chahine, Katy

    2008-10-01

    Post extraction sites may have residual ridge deformities with insufficient bone present for future implant placement. This presents a challenge to the clinician attempting to obtain optimum results. To predictably augment these areas and obtain aesthetically pleasing results, bone grafting may be required. Guided bone regeneration with an allograft material is a predictable means by which to solve this challenge. This article describes three case presentations utilizing on allograft material for bone regeneration prior to implant placement.

  12. Histologic Evaluation of Bone Healing Capacity Following Application of Inorganic Bovine Bone and a New Allograft Material in Rabbit Calvaria

    PubMed Central

    Paknejad, Mojgan; Rokn, AmirReza; Rouzmeh, Nina; Heidari, Mohadeseh; Titidej, Azadehzeinab; Kharazifard, Mohammad Javad; Mehrfard, Ali

    2015-01-01

    Objectives: Considering the importance of bone augmentation prior to implant placement in order to obtain adequate bone quality and quantity, many studies have been conducted to evaluate different techniques and materials regarding new bone formation. In this study, we investigated the bone healing capacity of two different materials deproteinized bovine bone mineral (DBBM with the trade name of Bio-Oss) and demineralized freeze-dried bone allograft (DFDBA with the trade name of DynaGraft). Materials and Methods: This randomized blinded prospective study was conducted on twelve New Zealand white rabbits. Three cranial defects with an equal diameter were created on their calvarium. Subsequently, they were distributed into three groups: 1. The control group without any treatment; 2. The Bio-Oss group; 3. The DynaGraft group. After 30 days, the animals were sacrificed for histologic and histomorphometric analysis. Results: Substantial new bone formation was observed in both groups. DynaGraft: 56/1 % ± 15/1 and Bio-Oss: 53/55 % ± 13/5 compared to the control group: 28/6 % ± 11/2. All groups showed slight inflammation and a small amount of residual biomaterial was observed. Conclusion: Considerable new bone formation was demonstrated in both DynaGraft and Bio-Oss groups in comparison with the control group. Both materials are considered biocompatible regarding the negligible foreign body reaction. PMID:26005452

  13. Differential effect of amelogenin peptides on osteogenic differentiation in vitro: identification of possible new drugs for bone repair and regeneration.

    PubMed

    Amin, Harsh D; Olsen, Irwin; Knowles, Jonathan C; Donos, Nikolaos

    2012-06-01

    Enamel matrix proteins (EMP) have been shown to promote regeneration of periodontal ligament and root cementum, and sometimes to enhance the differentiation of bone-forming cells in vitro and new bone growth in vivo. However, the inconsistent and unpredictable effects of EMP that have been reported for bone regeneration may be due to the highly variable composition of this heterogeneous material, which is comprised mainly of amelogenin and amelogenin-derived peptides. The present study has therefore examined the effects of naturally occurring low-molecular-weight (LMW) and high-molecular-weight (HMW) fractions of Emdogain(®) (EMD; Institut Straumann, Basel, Switzerland), a commercially available form of EMP, on osteogenic differentiation of bone precursor cells in vitro. In addition, the effects of chemically synthesized specific components of LMW and HMW-namely, the tyrosine-rich amelogenin peptide (TRAP), a specific amelogenin isoform derived by proteolytic clipping, and a leucine-rich amelogenin peptide (LRAP), an isoform derived by alternative splicing-on bone-forming cell activity were also investigated. Our findings demonstrate that while TRAP suppressed the formation of bone-like mineralized nodules, LRAP upregulated osteogenic differentiation. Furthermore, synthetically produced TRAP and its unique C-terminal 12 amino acid sequence (TCT) also suppressed bone-forming cells, whereas LRAP and its unique C-terminal 23 amino acid sequence (LCT) markedly enhanced terminal differentiation of bone-forming cells. These findings suggest that the differential effects of amelogenin-derived peptide sequences present in EMP could be of potential clinical value, with the novel bioactive TCT peptide as a useful tool for limiting pathological bone cell growth and the unique LCT sequence having therapeutic benefits in the treatment of periodontal and orthopedic diseases. PMID:22320389

  14. Preparation and bioactive properties of novel bone-repair bionanocomposites based on hydroxyapatite and bioactive glass nanoparticles.

    PubMed

    Valenzuela, Francisco; Covarrubias, Cristian; Martínez, Constanza; Smith, Patricio; Díaz-Dosque, Mario; Yazdani-Pedram, Mehrdad

    2012-08-01

    Bionanocomposites based on ceramic nanoparticles and a biodegradable porous matrix represent a promising strategy for bone repair applications. The preparation and bioactive properties of bionanocomposites based on hydroxyapatite (nHA) and bioactive glass (nBG) nanoparticles were presented. nHA and nBG were synthesized with nanometric particle size using sol-gel/precipitation methods. Composite scaffolds were prepared by incorporating nHA and nBG into a porous alginate (ALG) matrix at different particle loads. The ability of the bionanocomposites to induce the crystallization of the apatite phase from simulated body fluid (SBF) was systematically evaluated using X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray analysis, and Fourier transform infrared spectroscopy. Both nHA/ALG and nBG/ALG composites were shown to notably accelerate the process of crystallization and growth of the apatite phase on the scaffold surfaces. For short immersion times in SBF, nBG (25%)-based nanocomposites induced a higher degree of apatite crystallization than nHA (25%)-based nanocomposites, probably due to the more reactive nature of the BG particles. Through a reinforcement effect, the nanoparticles also improve the mechanical properties and stability in SBF of the polymer scaffold matrix. In addition, in vitro biocompatibility tests demonstrated that osteoblast cells are viable and adhere well on the surface of the bionanocomposites. These results indicate that nHA- and nBG-based bionanocomposites present potential properties for bone repair applications, particularly oriented to accelerate the bone mineralization process.

  15. Organoapatites: materials for artificial bone. I. Synthesis and microstructure.

    PubMed

    Stupp, S I; Ciegler, G W

    1992-02-01

    We have synthesized a new family of materials we termed organoapatites which may be useful in the formulation of artificial bone. These materials are synthesized by nucleation and growth of apatite crystals in media containing poly(amino acids) or synthetic organic polyelectrolytes using strict atmospheric, temperature, and pH control. The macromolecules used to synthesize the organoapatites include poly(L-lysine), poly(L-glutamic acid), and poly(sodium acrylate). The products were characterized by x-ray diffraction, scanning electron microscopy, surface area measurements, elemental analysis, and spectroscopic techniques. Organoapatites were found to contain large surface area morphologies with small crystallites which mature slowly based on analysis of Ca/P ratios. The organic macromolecules are thought to induce nucleation of crystals but also to quench their growth, thus becoming intimately dispersed in a mineral network. The organomineral particles harvested from the reaction medium contain polymer-netted microcrystals, and for this reason the synthetic approach can be used to modulate crystal maturation and biological response. It is likely that the preparative approach mimics some aspects of natural bone matrix synthesis and could be specially useful in the preparation of mineral implants containing intimate dispersions of small amounts of biomolecules such as growth factors, special drugs, or bioadhesives.

  16. Geopolymers as potential repair material in tiles conservation

    NASA Astrophysics Data System (ADS)

    Geraldes, Catarina F. M.; Lima, Augusta M.; Delgado-Rodrigues, José; Mimoso, João Manuel; Pereira, Sílvia R. M.

    2016-03-01

    The restoration materials currently used to fill gaps in historical architectural tiles (e.g. lime or organic resin pastes) usually show serious drawbacks in terms of compatibility, effectiveness or durability. The existing solutions do not fully protect Portuguese faïence tiles ( azulejos) in outdoor conditions and frequently result in further deterioration. Geopolymers can be a potential solution for tile lacunae infill, given the chemical-mineralogical similitude to the ceramic body, and also the durability and versatile range of physical properties that can be obtained through the manipulation of their formulation and curing conditions. This work presents and discusses the viability of the use of geopolymeric pastes to fill lacunae in tiles or to act as "cold" cast ceramic tile surrogates reproducing missing tile fragments. The formulation of geopolymers, namely the type of activators, the alumino-silicate source, the quantity of water required for adequate workability and curing conditions, was studied. The need for post-curing desalination was also considered envisaging their application in the restoration of outdoor historical architectural tiles frequently exposed to adverse environmental conditions. The possible advantages and disadvantages of the use of geopolymers in the conservation of tiles are also discussed. The results obtained reveal that geopolymers pastes are a promising material for the restoration of tiles, when compared to other solutions currently in use.

  17. Surveying the repair of ancient DNA from bones via high-throughput sequencing.

    PubMed

    Mouttham, Nathalie; Klunk, Jennifer; Kuch, Melanie; Fourney, Ron; Poinar, Hendrik

    2015-07-01

    DNA damage in the form of abasic sites, chemically altered nucleotides, and strand fragmentation is the foremost limitation in obtaining genetic information from many ancient samples. Upon cell death, DNA continues to endure various chemical attacks such as hydrolysis and oxidation, but repair pathways found in vivo no longer operate. By incubating degraded DNA with specific enzyme combinations adopted from these pathways, it is possible to reverse some of the post-mortem nucleic acid damage prior to downstream analyses such as library preparation, targeted enrichment, and high-throughput sequencing. Here, we evaluate the performance of two available repair protocols on previously characterized DNA extracts from four mammoths. Both methods use endonucleases and glycosylases along with a DNA polymerase-ligase combination. PreCR Repair Mix increases the number of molecules converted to sequencing libraries, leading to an increase in endogenous content and a decrease in cytosine-to-thymine transitions due to cytosine deamination. However, the effects of Nelson Repair Mix on repair of DNA damage remain inconclusive. PMID:26156780

  18. Effects of lubricant and autologous bone marrow stromal cell augmentation on immobilized flexor tendon repairs.

    PubMed

    Zhao, Chunfeng; Ozasa, Yasuhiro; Shimura, Haruhiko; Reisdorf, Ramona L; Thoreson, Andrew R; Jay, Gregory; Moran, Steven L; An, Kai-Nan; Amadio, Peter C

    2016-01-01

    The purpose of the study was to test a novel treatment that carbodiimide-derivatized-hyaluronic acid-lubricin (cd-HA-lubricin) combined cell-based therapy in an immobilized flexor tendon repair in a canine model. Seventy-eight flexor tendons from 39 dogs were transected. One tendon was treated with cd-HA-lubricin plus an interpositional graft of 8 × 10(5) BMSCs and GDF-5. The other tendon was repaired without treatment. After 21 day of immobilization, 19 dogs were sacrificed; the remaining 20 dogs underwent a 21-day rehabilitation protocol before euthanasia. The work of flexion, tendon gliding resistance, and adhesion score in treated tendons were significantly less than the untreated tendons (p < 0.05). The failure strength of the untreated tendons was higher than the treated tendons at 21 and 42 days (p < 0.05). However, there is no significant difference in stiffness between two groups at day 42. Histologic analysis of treated tendons showed a smooth surface and viable transplanted cells 42 days after the repair, whereas untreated tendons showed severe adhesion formation around the repair site. The combination of lubricant and cell treatment resulted in significantly improved digit function, reduced adhesion formation. This novel treatment can address the unmet needs of patients who are unable to commence an early mobilization protocol after flexor tendon repair. PMID:26177854

  19. Surveying the repair of ancient DNA from bones via high-throughput sequencing.

    PubMed

    Mouttham, Nathalie; Klunk, Jennifer; Kuch, Melanie; Fourney, Ron; Poinar, Hendrik

    2015-07-01

    DNA damage in the form of abasic sites, chemically altered nucleotides, and strand fragmentation is the foremost limitation in obtaining genetic information from many ancient samples. Upon cell death, DNA continues to endure various chemical attacks such as hydrolysis and oxidation, but repair pathways found in vivo no longer operate. By incubating degraded DNA with specific enzyme combinations adopted from these pathways, it is possible to reverse some of the post-mortem nucleic acid damage prior to downstream analyses such as library preparation, targeted enrichment, and high-throughput sequencing. Here, we evaluate the performance of two available repair protocols on previously characterized DNA extracts from four mammoths. Both methods use endonucleases and glycosylases along with a DNA polymerase-ligase combination. PreCR Repair Mix increases the number of molecules converted to sequencing libraries, leading to an increase in endogenous content and a decrease in cytosine-to-thymine transitions due to cytosine deamination. However, the effects of Nelson Repair Mix on repair of DNA damage remain inconclusive.

  20. Strontium administration in young chickens improves bone volume and architecture but does not enhance bone structural and material strength.

    PubMed

    Shahnazari, M; Lang, D H; Fosmire, G J; Sharkey, N A; Mitchell, A D; Leach, R M

    2007-03-01

    Genetic selection for rapid body growth in broiler chickens has resulted in adverse effects on the skeletal system exemplified by a higher rate of cortical fractures in leg bones. Strontium (Sr) has been reported to have beneficial effects on bone formation and strength. We supplemented the diet of 300-day-old chicks with increasing dosages of Sr (0%, 0.12%, or 0.24%) to study the capacity of the element to improve bone quality and mechanical integrity. Treatment with Sr increased cortical bone volume and reduced bone porosity as measured by micro-computed tomography. The higher level of Sr significantly reduced bone Ca content (34.7%) relative to controls (37.2%), suggesting that Sr replaced some of the Ca in bone. Material properties determined by the three-point bending test showed that bone in the Sr-treated groups withstood greater deformation prior to fracture. Load to failure and ultimate stress were similar across groups. Our results indicate that Sr treatment in rapidly growing chickens induced positive effects on bone volume but did not improve the breaking strength of long bones. PMID:17340224

  1. BMP6-Engineered MSCs Induce Vertebral Bone Repair in a Pig Model: A Pilot Study

    PubMed Central

    Pelled, Gadi; Sheyn, Dmitriy; Tawackoli, Wafa; Jun, Deuk Soo; Koh, Youngdo; Su, Susan; Cohn Yakubovich, Doron; Kallai, Ilan; Antebi, Ben; Da, Xiaoyu; Gazit, Zulma; Bae, Hyun; Gazit, Dan

    2016-01-01

    Osteoporotic patients, incapacitated due to vertebral compression fractures (VCF), suffer grave financial and clinical burden. Current clinical treatments focus on symptoms' management but do not combat the issue at the source. In this pilot study, allogeneic, porcine mesenchymal stem cells, overexpressing the BMP6 gene (MSC-BMP6), were suspended in fibrin gel and implanted into a vertebral defect to investigate their effect on bone regeneration in a clinically relevant, large animal pig model. To check the effect of the BMP6-modified cells on bone regeneration, a fibrin gel only construct was used for comparison. Bone healing was evaluated in vivo at 6 and 12 weeks and ex vivo at 6 months. In vivo CT showed bone regeneration within 6 weeks of implantation in the MSC-BMP6 group while only minor bone formation was seen in the defect site of the control group. After 6 months, ex vivo analysis demonstrated enhanced bone regeneration in the BMP6-MSC group, as compared to control. This preclinical study presents an innovative, potentially minimally invasive, technique that can be used to induce bone regeneration using allogeneic gene modified MSCs and therefore revolutionize current treatment of challenging conditions, such as osteoporosis-related VCFs. PMID:26770211

  2. Physical and mechanical characterization of a porous cement for metaphyseal bone repair

    PubMed Central

    Cimatti, Bruno; Engel, Edgard Eduard; Nogueira-Barbosa, Marcello Henrique; Frighetto, Paulo Donato; Volpon, José Batista

    2015-01-01

    OBJECTIVE: Macroporous cement with mechanical properties similar to cancellous bone may improve the treatment of large bone defects in relation to solid acrylic cement. The aim of this study was to compare physical and mechanical characteristics of a polymethyl methacrylate (PMMA) based porous cement with cancellous bone. METHODS: Compressive strength and pore size, interconnectivity, and distribution of cylindrical porous PMMA cement samples containing 10% (G1), 20% (G2) or 30% (G3) effervescent components were analyzed. Results were compared to bovine cancellous bone (G4) and solid PMMA (G5) samples. RESULTS: Scanning electron microscopy (SEM) of all experimental samples (G1 - G3) revealed a random distribution and a wide size variation of pores ranging from 50 µm to 3 mm. Micro-CT showed that G2 have high porosity and lower interconnectivity of pores. No significant differences in yield strength and Young's modulus were observed among G1, G2 and G3. G4 samples were slightly stronger and less elastic than the other groups. Solid PMMA is extremely strong and inelastic. CONCLUSIONS: PMMA based porous cement met the expected characteristics. High porosity with large and interconnected pores may allow for bone ingrowth. Strength and elasticity similar to cancellous bone may enhance mechanical stimuli to bone remodeling. Observational Descriptive Study. PMID:26327801

  3. Nonpulsed sinusoidal electromagnetic fields as a noninvasive strategy in bone repair: the effect on human mesenchymal stem cell osteogenic differentiation.

    PubMed

    Ledda, Mario; D'Emilia, Enrico; Giuliani, Livio; Marchese, Rodolfo; Foletti, Alberto; Grimaldi, Settimio; Lisi, Antonella

    2015-02-01

    In vivo control of osteoblast differentiation is an important process needed to maintain the continuous supply of mature osteoblast cells for growth, repair, and remodeling of bones. The regulation of this process has also an important and significant impact on the clinical strategies and future applications of cell therapy. In this article, we studied the effect of nonpulsed sinusoidal electromagnetic field radiation tuned at calcium-ion cyclotron frequency of 50 Hz exposure treatment for bone differentiation of human mesenchymal stem cells (hMSCs) alone or in synergy with dexamethasone, their canonical chemical differentiation agent. Five days of continuous exposure to calcium-ion cyclotron resonance affect hMSC proliferation, morphology, and cytoskeletal actin reorganization. By quantitative real-time polymerase chain reaction, we also observed an increase of osteoblast differentiation marker expression such as Runx2, alkaline phosphatase (ALP), osteocalcin (OC), and osteopontin (OPN) together with the osteoprotegerin mRNA modulation. Moreover, in these cells, the increase of the protein expression of OPN and ALP was also demonstrated. These results demonstrate bone commitment of hMSCs through a noninvasive and biocompatible differentiating physical agent treatment and highlight possible applications in new regenerative medicine protocols. PMID:25087470

  4. Experimental repair of segmental bone defects in rabbits by angiopoietin-1 gene transfected MSCs seeded on porous β-TCP scaffolds.

    PubMed

    Cao, Le; Liu, Xudong; Liu, Shen; Jiang, Yao; Zhang, Xianlong; Zhang, Changqing; Zeng, Bingfang

    2012-07-01

    Segmental bone defect repair remains a clinical and experimental challenge in tissue engineering with increasing focus on angiogenesis in the bone substitutes. The objective of this study was to investigate the osteogenic effects of angiopoietin-1 (Ang-1) gene transfected bone marrow-derived mesenchymal stem cells (MSCs) seeded on porous β-TCP scaffolds. This bone substitute (experimental group) and MSCs/β-TCP compounds (control group) were implanted into 15 mm segmental bone defects of the radii of 30 New Zealand white rabbits, with platelet-rich plasma injected at the same time. Bone regeneration and angiogenesis were assessed by Scanning electron microscope (SEM), X-ray, histology, immunohistology, and biomechanical outcome measurements made on the 2nd, 4th, 8th, and 12th week after the operation. In vitro, the amount of proliferation and differentiation of Ang-1 gene transfected MSCs was found to be gross increased than that of the control groups. In vivo, a significantly increased amount of new bone formation accompanied by active capillary vasculature regeneration was observed in the pores of the scaffolds which had been seeded with Ang-1 gene transfected MSCs, as compared with the control groups. The biomechanical test confirmed the failure load of new born bone was close to normal bone. These results suggest that transfer of gene encoding Ang-1 to MSCs increases their osteogenic properties by enhancing capillary regeneration, thus providing a rich blood supply for new bone formation in segmental bone defects.

  5. The effects of multiple-strand suture techniques on the tensile properties of repair of the flexor digitorum profundus tendon to bone.

    PubMed

    Silva, M J; Hollstien, S B; Fayazi, A H; Adler, P; Gelberman, R H; Boyer, M I

    1998-10-01

    We examined the effects of multiple-strand suture techniques on the tensile properties of flexor digitorum profundus tendon-to-bone repairs in a human cadaver finger model. Forty-four fingers were obtained from the cadavera of fifteen donors who had been an average of seventy-four years old (range, fifty-four to eighty-nine years old) at the time of death. Four or eight-strand proximal grasping sutures were secured to the distal phalanx of each finger with use of either a suture anchor or a dorsally placed button. There were four subgroups of eleven fingers each. We found that repairs performed with use of a dorsally placed button had greater yield force, ultimate force, and rigidity than those performed with use of an anchor and that repairs performed with eight strands had greater ultimate force than those performed with four strands. These differences were significant (p < 0.05). We could detect no differences among the four types of repairs with regard to the amount of relative tendon-bone elongation at twenty newtons of force. The repairs performed with eight strands and a dorsally placed button had an average yield force (and 95 per cent confidence interval) of 50.0 +/- 14.1 newtons, an average ultimate force of 68.5 +/- 14.6 newtons, an average rigidity of 744 +/- 327 newton/(millimeter/millimeter), and an average tendon-bone elongation of 3.4 +/- 0.7 millimeters at twenty newtons of force. Multiple-comparison testing showed that the eight-strand repairs performed with a dorsally placed button had greater ultimate force than the other three types of repairs as well as greater yield force and rigidity than the four and eight-strand repairs performed with a suture anchor.

  6. Bone repair: new developments in growth factor delivery systems and their mathematical modeling.

    PubMed

    Lauzon, Marc-Antoine; Bergeron, Eric; Marcos, Bernard; Faucheux, Nathalie

    2012-09-28

    More and more of our aging populations will suffer from large bone defects in the next few years. But the growth factor (GF) delivery systems (DSs) currently under investigation will help overcome the limitations of the bone grafts presently used. Some GFDSs accredited by the Food and Drug Administration (FDA) are commercially available, but they have mechanical, structural and GF retention weaknesses. New studies focus on polymers and the composition of GFs in order to mimic as closely as possible the physiological environment of healing bone. This review first summarizes the process of endochondral bone healing and the major cytokines involved. We then review the latest GFDSs, with their combinations of organic, inorganic, natural and synthetic biomaterials, the kinetics of GF release and their biological effects. We will explore new research avenues such as the use of peptides derived from bone morphogenetic proteins, including our own results, and the sequential release of bone-inducing GFs. We then review the latest mathematical models of drug delivery systems (DDSs) for several transport phenomena that may be encountered when using GFDS. The final section discusses new improvements for GFDS modeling.

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

    PubMed

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

    1993-03-01

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

  8. Allogeneic Versus Autologous Derived Cell Sources for Use in Engineered Bone-Ligament-Bone Grafts in Sheep Anterior Cruciate Ligament Repair

    PubMed Central

    Mahalingam, Vasudevan D.; Behbahani-Nejad, Nilofar; Horine, Storm V.; Olsen, Tyler J.; Smietana, Michael J.; Wojtys, Edward M.; Wellik, Deneen M.; Arruda, Ellen M.

    2015-01-01

    The use of autografts versus allografts for anterior cruciate ligament (ACL) reconstruction is controversial. The current popular options for ACL reconstruction are patellar tendon or hamstring autografts, yet advances in allograft technologies have made allogeneic grafts a favorable option for repair tissue. Despite this, the mismatched biomechanical properties and risk of osteoarthritis resulting from the current graft technologies have prompted the investigation of new tissue sources for ACL reconstruction. Previous work by our lab has demonstrated that tissue-engineered bone-ligament-bone (BLB) constructs generated from an allogeneic cell source develop structural and functional properties similar to those of native ACL and vascular and neural structures that exceed those of autologous patellar tendon grafts. In this study, we investigated the effectiveness of our tissue-engineered ligament constructs fabricated from autologous versus allogeneic cell sources. Our preliminary results demonstrate that 6 months postimplantation, our tissue-engineered auto- and allogeneic BLB grafts show similar histological and mechanical outcomes indicating that the autologous grafts are a viable option for ACL reconstruction. These data indicate that our tissue-engineered autologous ligament graft could be used in clinical situations where immune rejection and disease transmission may preclude allograft use. PMID:25397361

  9. Allogeneic versus autologous derived cell sources for use in engineered bone-ligament-bone grafts in sheep anterior cruciate ligament repair.

    PubMed

    Mahalingam, Vasudevan D; Behbahani-Nejad, Nilofar; Horine, Storm V; Olsen, Tyler J; Smietana, Michael J; Wojtys, Edward M; Wellik, Deneen M; Arruda, Ellen M; Larkin, Lisa M

    2015-03-01

    The use of autografts versus allografts for anterior cruciate ligament (ACL) reconstruction is controversial. The current popular options for ACL reconstruction are patellar tendon or hamstring autografts, yet advances in allograft technologies have made allogeneic grafts a favorable option for repair tissue. Despite this, the mismatched biomechanical properties and risk of osteoarthritis resulting from the current graft technologies have prompted the investigation of new tissue sources for ACL reconstruction. Previous work by our lab has demonstrated that tissue-engineered bone-ligament-bone (BLB) constructs generated from an allogeneic cell source develop structural and functional properties similar to those of native ACL and vascular and neural structures that exceed those of autologous patellar tendon grafts. In this study, we investigated the effectiveness of our tissue-engineered ligament constructs fabricated from autologous versus allogeneic cell sources. Our preliminary results demonstrate that 6 months postimplantation, our tissue-engineered auto- and allogeneic BLB grafts show similar histological and mechanical outcomes indicating that the autologous grafts are a viable option for ACL reconstruction. These data indicate that our tissue-engineered autologous ligament graft could be used in clinical situations where immune rejection and disease transmission may preclude allograft use.

  10. Mesenchymal Stem Cells Ageing: Targeting the "Purinome" to Promote Osteogenic Differentiation and Bone Repair.

    PubMed

    Noronha-Matos, J B; Correia-de-Sá, P

    2016-09-01

    Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into bone forming cells. Such ability is compromised in elderly individuals resulting in bone disorders such as osteoporosis, also limiting their clinical usage for cell transplantation and bone tissue engineering strategies. In bone marrow niches, adenine and uracil nucleotides are important local regulators of osteogenic differentiation of MSCs. Nucleotides can be released to the extracellular milieu under both physiological and pathological conditions via (1) membrane cell damage, (2) vesicle exocytosis, (3) ATP-binding cassette transporters, and/or (4) facilitated diffusion through maxi-anion channels, hemichannels or ligand-gated receptor pores. Nucleotides and their derivatives act via adenosine P1 (A1 , A2A , A2B , and A3 ) and nucleotide-sensitive P2 purinoceptors comprising ionotropic P2X and G-protein-coupled P2Y receptors. Purinoceptors activation is terminated by membrane-bound ecto-nucleotidases and other ecto-phosphatases, which rapidly hydrolyse extracellular nucleotides to their respective nucleoside 5'-di- and mono-phosphates, nucleosides and free phosphates, or pyrophosphates. Current knowledge suggests that different players of the "purinome" cascade, namely nucleotide release sites, ecto-nucleotidases and purinoceptors, orchestrate to fine-tuning regulate the activity of MSCs in the bone microenvironment. Increasing studies, using osteoprogenitor cell lines, animal models and, more recently, non-modified MSCs from postmenopausal women, raised the possibility to target chief components of the purinergic signaling pathway to regenerate the ability of aged MSCs to differentiate into functional osteoblasts. This review summarizes the main findings of those studies, prompting for novel therapeutic strategies to control ageing disorders where bone destruction exceeds bone formation, like osteoporosis, rheumatoid arthritis, and fracture mal-union. J. Cell. Physiol. 231: 1852

  11. Mesenchymal Stem Cell Therapy Regenerates the Native Bone-Tendon Junction after Surgical Repair in a Degenerative Rat Model

    PubMed Central

    Nourissat, Geoffroy; Diop, Amadou; Maurel, Nathalie; Salvat, Colette; Dumont, Sylvie; Pigenet, Audrey; Gosset, Marjolaine; Houard, Xavier; Berenbaum, Francis

    2010-01-01

    Background The enthesis, which attaches the tendon to the bone, naturally disappears with aging, thus limiting joint mobility. Surgery is frequently needed but the clinical outcome is often poor due to the decreased natural healing capacity of the elderly. This study explored the benefits of a treatment based on injecting chondrocyte and mesenchymal stem cells (MSC) in a new rat model of degenerative enthesis repair. Methodology The Achilles' tendon was cut and the enthesis destroyed. The damage was repaired by classical surgery without cell injection (group G1, n = 52) and with chondrocyte (group G2, n = 51) or MSC injection (group G3, n = 39). The healing rate was determined macroscopically 15, 30 and 45 days later. The production and organization of a new enthesis was assessed by histological scoring of collagen II immunostaining, glycoaminoglycan production and the presence of columnar chondrocytes. The biomechanical load required to rupture the bone-tendon junction was determined. Principal Findings The spontaneous healing rate in the G1 control group was 40%, close to those observed in humans. Cell injection significantly improved healing (69%, p = 0.0028 for G2 and p = 0.006 for G3) and the load-to-failure after 45 days (p<0.05) over controls. A new enthesis was clearly produced in cell-injected G2 and G3 rats, but not in the controls. Only the MSC-injected G3 rats had an organized enthesis with columnar chondrocytes as in a native enthesis 45 days after surgery. Conclusions Cell therapy is an efficient procedure for reconstructing degenerative entheses. MSC treatment produced better organ regeneration than chondrocyte treatment. The morphological and biomechanical properties were similar to those of a native enthesis. PMID:20805884

  12. Repair of bone defect by nano-modified white mineral trioxide aggregates in rabbit: A histopathological study

    PubMed Central

    Saghiri, Mohammad-Ali; Tanideh, Nader; Asatourian, Armen; Janghorban, Kamal; Garcia-Godoy, Franklin; Sheibani, Nader

    2015-01-01

    Background Many researchers have tried to enhance materials functions in different aspects of science using nano-modification method, and in many cases the results have been encouraging. To evaluate the histopathological responses of the micro-/nano-size cement-type biomaterials derived from calcium silicate-based composition with addition of nano tricalcium aluminate (3CaO.Al2O3) on bone healing response. Material and Methods Ninety mature male rabbits were anesthetized and a bone defect was created in the right mandible. The rabbits were divided into three groups, which were in turn subdivided into five subgroups with six animals each based on the defect filled by: white mineral trioxide aggregate (WMTA), Nano-WMTA, WMTA without 3CaO.Al2O3, Nano-WMTA with 2% Nano-3CaO.Al2O3, and empty as control. Twenty, forty and sixty days postoperatively the animals were sacrificed and the right mandibles were removed for histopathological evaluations. Kruskal-Wallis test with post-hoc comparisons based on the LSMeans procedure was used for data analysis. Results All the experimental materials provoked a moderate to severe inflammatory reaction, which significantly differed from the control group (p< 0.05). Statistical analysis of bone formation and bone regeneration data showed significant differences between groups at 40- and 60- day intervals in all groups. Absence of 3CaO.Al2O3 leads to more inflammation and foreign body reaction than other groups in all time intervals. Conclusions Both powder nano-modification and addition of 2% Nano-3CaO.Al2O3 to calcium silicate-based cement enhanced the favorable tissue response and osteogenesis properties of WMTA based materials. Key words:Bone regeneration, cement, endodontics, histopathology, nano-wmta, tricalcium aluminate. PMID:26034924

  13. Effect of microwave irradiation on the flexural strength and residual monomer levels of an acrylic resin repair material.

    PubMed

    Yunus, N; Harrison, A; Huggett, R

    1994-11-01

    The degree of polymerization of an acrylic resin repair material, as established by residual monomer estimation, was compared using three different polymerization methods, i.e. bench-cure, hydroflask-cure and microwave irradiation cure. The repair strength of a conventional heat-polymerized resin was then assessed following repairs using each of these three methods. The lowest level of residual monomer was achieved with the microwave irradiation cure. It was also demonstrated that of the three methods, polymerization using microwave energy resulted in the strongest repair.

  14. Comparison of Human Embryonic Stem Cell-Derived Cardiomyocytes, Cardiovascular Progenitors, and Bone Marrow Mononuclear Cells for Cardiac Repair

    PubMed Central

    Fernandes, Sarah; Chong, James J.H.; Paige, Sharon L.; Iwata, Mineo; Torok-Storb, Beverly; Keller, Gordon; Reinecke, Hans; Murry, Charles E.

    2015-01-01

    Summary Cardiomyocytes derived from human embryonic stem cells (hESC-CMs) can improve the contractility of injured hearts. We hypothesized that mesodermal cardiovascular progenitors (hESC-CVPs), capable of generating vascular cells in addition to cardiomyocytes, would provide superior repair by contributing to multiple components of myocardium. We performed a head-to-head comparison of hESC-CMs and hESC-CVPs and compared these with the most commonly used clinical cell type, human bone marrow mononuclear cells (hBM-MNCs). In a nude rat model of myocardial infarction, hESC-CMs and hESC-CVPs generated comparable grafts. Both similarly improved systolic function and ventricular dilation. Furthermore, only rare human vessels formed from hESC-CVPs. hBM-MNCs attenuated ventricular dilation and enhanced host vascularization without engrafting long-term or improving contractility. Thus, hESC-CMs and CVPs show similar efficacy for cardiac repair, and both are more efficient than hBM-MNCs. However, hESC-CVPs do not form larger grafts or more significant numbers of human vessels in the infarcted heart. PMID:26607951

  15. Low-level laser therapy enhances the expression of osteogenic factors during bone repair in rats.

    PubMed

    Tim, Carla Roberta; Pinto, Karina Nogueira Zambone; Rossi, Bruno Rafael Orsini; Fernandes, Kelly; Matsumoto, Mariza Akemi; Parizotto, Nivaldo Antonio; Rennó, Ana Claudia Muniz

    2014-01-01

    The aim of this study was to evaluate the effects of low-level laser therapy (LLLT) on bone formation, immunoexpression of osteogenic factors, and biomechanical properties in a tibial bone defect model in rats. Sixty male Wistar rats were distributed into bone defect control group (CG) and laser irradiated group (LG). Animals were euthanized on days 15, 30, and 45 post-injury. The histological and morphometric analysis showed that the treated animals presented no inflammatory infiltrate and a better tissue organization at 15 and 30 days postsurgery. Also, a higher amount of newly formed bone was observed at 15 days postsurgery. No statistically significant difference was observed in cyclooxygenase-2 immunoexpression among the groups at 15, 30, and 45 days in the immunohistochemical analysis. Considering RUNX-2, the immunoexpression was statistically higher in the LG compared to the CG at 45 days. BMP-9 immunoexpression was significantly higher in the LG in comparison to CG at day 30. However, there was no expressivity for this immunomarker, both in the CG and LG, at the day 45 postsurgery. No statistically significant difference was observed in the receptor activator of nuclear factor kappa-B ligand immunoexpression among the groups in all periods evaluated. No statistically significant difference among the groups was observed in the maximal load in any period of time. Our findings indicate that laser therapy improved bone healing by accelerating the development of newly formed bone and activating the osteogenic factors on tibial defects, but the biomechanical properties in LG were not improved. PMID:23515631

  16. Repair of segmental load-bearing bone defect by autologous mesenchymal stem cells and plasma-derived fibrin impregnated ceramic block results in early recovery of limb function.

    PubMed

    Ng, Min Hwei; Duski, Suryasmi; Tan, Kok Keong; Yusof, Mohd Reusmaazran; Low, Kiat Cheong; Rose, Isa Mohamed; Mohamed, Zahiah; Bin Saim, Aminuddin; Idrus, Ruszymah Bt Hj

    2014-01-01

    Calcium phosphate-based bone substitutes have not been used to repair load-bearing bone defects due to their weak mechanical property. In this study, we reevaluated the functional outcomes of combining ceramic block with osteogenic-induced mesenchymal stem cells and platelet-rich plasma (TEB) to repair critical-sized segmental tibial defect. Comparisons were made with fresh marrow-impregnated ceramic block (MIC) and partially demineralized allogeneic bone block (ALLO). Six New Zealand White female rabbits were used in each study group and three rabbits with no implants were used as negative controls. By Day 90, 4/6 rabbits in TEB group and 2/6 in ALLO and MIC groups resumed normal gait pattern. Union was achieved significantly faster in TEB group with a radiological score of 4.50 ± 0.78 versus ALLO (1.06 ± 0.32), MIC (1.28 ± 0.24), and negative controls (0). Histologically, TEB group scored the highest percentage of new bone (82% ± 5.1%) compared to ALLO (5% ± 2.5%) and MIC (26% ± 5.2%). Biomechanically, TEB-treated tibiae achieved the highest compressive strength (43.50 ± 12.72 MPa) compared to those treated with ALLO (15.15 ± 3.57 MPa) and MIC (23.28 ± 6.14 MPa). In conclusion, TEB can repair critical-sized segmental load-bearing bone defects and restore limb function.

  17. Is repetitive wounding and bone marrow-derived stem cell mediated-repair an etiology of lung cancer development and dissemination?

    PubMed

    Haura, Eric B

    2006-01-01

    The prevailing view of lung cancer is multi-step progression of normal cells into cancer cells through gain of function oncogenes coupled with loss of tumor suppressor genes. This progression of genetic damage ultimately results in the hallmarks of cancer. This theory has strong support from studies finding genetic damage in early stage preneoplastic lesions in lung epithelial cells from current or former smokers. This paper discusses an alternate theory that lung cancer is a bone marrow stem cell derived disease. Chronic cigarette smoking results in lung inflammation and epithelial damage that activates a chronic wound repair program. Recent studies have demonstrated that ability of bone marrow derived stem cells to respond to epithelial wounding and contribute to epithelial repair. The identification of cancer stem cells that are distinct from the bulk tumor cells through their ability of self-renewal may suggest that such cells are important in the development of lung cancer. The evidence supporting the hypothesis along with its implications are discussed. Confirmation of the hypothesis would suggest that the transition time from a normal cell to overt cancer cell may be much shorter than that based on the multi-step cancer progression model. Additionally, if wounding in other organs is a beacon that attracts bone marrow derived tumor cells, efforts to ameliorate areas of epithelial injury and compensatory wounding may block bone marrow derived tumor cell homing, aberrant repair, and metastasis. Finally, a bone marrow derived lung cancer stem cell would require stem cell poisons for cure.

  18. LENS repair and modification of metal NW components:materials and applications guide.

    SciTech Connect

    Smugeresky, John E. (Sandia National Laboratories, Livermore, CA); Gill, David Dennis; Oberhaus, Jason (BWXT Y-12); Adams, Thad; VanCamp, Chad

    2006-11-01

    Laser Engineered Net Shaping{trademark} (LENS{reg_sign}) is a unique, layer additive, metal manufacturing technique that offers the ability to create fully dense metal features and components directly from a computer solid model. LENS offers opportunities to repair and modify components by adding features to existing geometry, refilling holes, repairing weld lips, and many other potential applications. The material deposited has good mechanical properties with strengths typically slightly higher that wrought material due to grain refinement from a quickly cooling weld pool. The result is a material with properties similar to cold worked material, but without the loss in ductility traditionally seen with such treatments. Furthermore, 304L LENS material exhibits good corrosion resistance and hydrogen compatibility. This report gives a background of the LENS process including materials analysis addressing the requirements of a number of different applications. Suggestions are given to aid both the product engineer and the process engineer in the successful utilization of LENS for their applications. The results of testing on interface strength, machinability, weldability, corrosion resistance, geometric effects, heat treatment, and repair strategy testing are all included. Finally, the qualification of the LENS process is briefly discussed to give the user confidence in selecting LENS as the process of choice for high rigor applications. The testing showed LENS components to have capability in repair/modification applications requiring complex castings (W80-3 D-Bottle bracket), thin wall parts requiring metal to be rebuilt onto the part (W87 Firing Set Housing and Y-12 Test Rings), the filling of counterbores for use in reservoir reclamation welding (SRNL hydrogen compatibility study) and the repair of surface defects on pressure vessels (SRNL gas bottle repair). The material is machinable, as testing has shown that LENS deposited material machines similar to that of

  19. Bone Marrow Stromal Cells Generate Muscle Cells and Repair Muscle Degeneration

    NASA Astrophysics Data System (ADS)

    Dezawa, Mari; Ishikawa, Hiroto; Itokazu, Yutaka; Yoshihara, Tomoyuki; Hoshino, Mikio; Takeda, Shin-ichi; Ide, Chizuka; Nabeshima, Yo-ichi

    2005-07-01

    Bone marrow stromal cells (MSCs) have great potential as therapeutic agents. We report a method for inducing skeletal muscle lineage cells from human and rat general adherent MSCs with an efficiency of 89%. Induced cells differentiated into muscle fibers upon transplantation into degenerated muscles of rats and mdx-nude mice. The induced population contained Pax7-positive cells that contributed to subsequent regeneration of muscle upon repetitive damage without additional transplantation of cells. These MSCs represent a more ready supply of myogenic cells than do the rare myogenic stem cells normally found in muscle and bone marrow.

  20. Resinous perforation-repair materials inhibit the growth, attachment, and proliferation of human gingival fibroblasts.

    PubMed

    Huang, Fu-Mei; Tai, Kuo-Wei; Chou, Ming-Yung; Chang, Yu-Chao

    2002-04-01

    The choice of repair material is one of the important factors in the prognosis of the endodontically treated tooth with a perforation defect. The cytotoxicity of perforation-repair materials must be investigated to ensure a safe biological response. The aim of this in vitro study was to evaluate the effect of resin-modified, glass-ionomer cement, compomer, and resin on human-gingival fibroblasts. Human gingival fibroblasts from crown lengthening surgery were cultured by using an explant technique with the consent of the patient. Cytotoxicity was judged by using an assay of tetrazolium bromide reduction. The results showed that resin-modified, glass-ionomer cement Fuji II LC, compomer Compoglass, and resin SpectrumTPH (TPH) were cytotoxic to primary human gingival fibroblast cultures by inhibiting cell growth and proliferation. TPH alone had an effect on cell attachment. It was found that TPH was the most cytotoxic repair material among those tested in all cultures. The toxicity decreased in the order of TPH>FLC>CG.

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

    NASA Astrophysics Data System (ADS)

    Deng, Meng

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

  2. Comparative study of the application of microcurrent and AsGa 904 nm laser radiation in the process of repair after calvaria bone excision in rats

    NASA Astrophysics Data System (ADS)

    Mendonça, J. S.; Neves, L. M. G.; Esquisatto, M. A. M.; Mendonça, F. A. S.; Santos, G. M. T.

    2013-03-01

    This study evaluated the effects of microcurrent stimulation (10 μA/5 min) and 904 nm GaAs laser irradiation (3 J cm-2 for 69 s/day) on excisional lesions created in the calvaria bone of Wistar rats. The results showed significant responses in the reduction of inflammatory cells and an increase in the number of new blood vessels, number of fibroblasts and deposition of birefringent collagen fibers when these data were compared with those of samples of the untreated lesions. Both applications, microcurrent and laser at 904 nm, favored tissue repair in the region of bone excisions during the study period and these techniques can be used as coadjuvantes in the repair of bone tissue.

  3. Defective bone repair in mast cell deficient mice with c-Kit loss of function.

    PubMed

    Behrends, D A; Cheng, L; Sullivan, M B; Wang, M H; Roby, G B; Zayed, N; Gao, C; Henderson, J E; Martineau, P A

    2014-01-01

    KitW-sh mice carry an inactivating mutation in the gene encoding the receptor for stem cell factor, which is expressed at high levels on the surface of haematopoietic precursor cells. The mutation results in mast cell deficiency, a variety of defects in innate immunity and poorly defined abnormalities in bone. The present study was designed to characterise healing of a cortical window defect in skeletally mature KitW-sh mice using high-resolution micro computed tomographic imaging and histological analyses. The cortical bone defect healed completely in all wild type mice but failed to heal in about half of the KitW-sh mice by 12 weeks post-operative. Defective healing was associated with premature and excessive expression of TRAP positive cells embedded in fibrous marrow but with little change in ALP activity. Immuno-histochemical analyses revealed reduced CD34 positive vascular endothelial cells and F4/80 positive macrophages at 1 and 2 weeks post-operative. Impaired bone healing in the KitW-sh mice was therefore attributed to altered catabolic activity, impaired re-vascularisation and compromised replacement of woven with compact bone. PMID:25284141

  4. Adhesion and growth of human bone marrow mesenchymal stem cells on precise-geometry 3D organic-inorganic composite scaffolds for bone repair.

    PubMed

    Chatzinikolaidou, Maria; Rekstyte, Sima; Danilevicius, Paulius; Pontikoglou, Charalampos; Papadaki, Helen; Farsari, Maria; Vamvakaki, Maria

    2015-03-01

    Engineering biomaterial scaffolds that promote attachment and growth of mesenchymal stem cells in three dimensions is a crucial parameter for successful bone tissue engineering. Towards this direction, a lot of research effort has focused recently into the development of three-dimensional porous scaffolds, aiming to elicit positive cellular behavior. However, the fabrication of three-dimensional tissue scaffolds with a precise geometry and complex micro- and nano-features, supporting cell in-growth remains a challenge. In this study we report on a positive cellular response of human bone marrow-derived (BM) mesenchymal stem cells (MSCs) onto hybrid material scaffolds consisting of methacryloxypropyl trimethoxysilane, zirconium propoxide, and 2-(dimethylamino)ethyl methacrylate (DMAEMA). First, we use Direct fs Laser Writing, a 3D scaffolding technology to fabricate the complex structures. Subsequently, we investigate the morphology, viability and proliferation of BM-MSCs onto the hybrid scaffolds and examine the cellular response from different donors. Finally, we explore the effect of the materials' chemical composition on cell proliferation, employing three different material surfaces: (i) a hybrid consisting of methacryloxypropyl trimethoxysilane, zirconium propoxide and 50mol% DMAEMA, (ii) a hybrid material comprising methacryloxypropyl trimethoxysilane and zirconium propoxide, and (iii) a purely organic polyDMAEMA. Our results show a strong adhesion of BM-MSCs onto the hybrid material containing 50% DMAEMA from the first 2h after seeding, and up to several days, and a proliferation increase after 14 and 21days, similar to the polystyrene control, independent of cell donor. These findings support the potential use of our proposed cell-material combination in bone tissue engineering.

  5. Mycobacterium tuberculosis Contaminant Risk on Bone Marrow Aspiration Material from Iliac Bone Patients with Active Tuberculous Spondylitis

    PubMed Central

    Rahyussalim, Ahmad Jabir; Kurniawati, Tri; Rukmana, Andriansjah

    2016-01-01

    There was a concern on Mycobacterium tuberculosis spreading to the bone marrow, when it was applied on tuberculous spine infection. This research aimed to study the probability of using autologous bone marrow as a source of mesenchymal stem cell for patients with tuberculous spondylitis. As many as nine patients with tuberculous spondylitis were used as samples. During the procedure, the vertebral lesion material and iliac bone marrow aspirates were obtained for acid fast staining, bacteria culture, and PCR (polymerase chain reaction) tests for Mycobacterium tuberculosis at the Clinical Microbiology Laboratory of Faculty of Medicine Universitas Indonesia. This research showed that there was a relationship between diagnostic confirmation of tuberculous spondylitis based on the PCR test and bacterial culture on the solid vertebral lesion material with the PCR test and bacterial culture from the bone marrow aspirates. If the diagnostic confirmation concluded positive results, then there was a higher probability that there would be a positive result for the bone marrow aspirates, so that it was not recommended to use autologous bone marrow as a source of mesenchymal stem cell for patients with tuberculous spondylitis unless the PCR and culture examination of the bone marrow showed a negative result. PMID:27294117

  6. Monoclinic Hydroxyapatite Nanoplates Hybrid Composite with Improved Compressive Strength, and Porosity for Bone Defect Repair: Biomimetic Synthesis and Characterization.

    PubMed

    Xue, Bo; Farghaly, Ahmed A; Guo, Zhenzhao; Zhao, Pengg; Li, Hong; Zhou, Changren; Li, Lihua

    2016-03-01

    Calcium phosphate cement (CPC) has been used for bone restoration despite its intrinsic fragile property. In order to enhance the CPC mechanical properties, biopolymers were introduced as filler to prepare CPC based cements. Chitosan/tetracalcium phosphate (TTCP)/dicalcium phosphate anhydrous (DCPA) based cement for bone repair has been prepared in the study. Solidification of the prepared cement was carried out in a simulate body fluid at 37 degrees C. The introduction of chitosan improved the mechanical performance of the as-prepared CPC hybrid nanocomposite. FTIR, SEM, TEM, HRTEM, XRD, and SAED were used to characterize the CPC nanocomposite. Data simulations have been performed to assist in determining the crystalline phase/s in the CPC hybrid nanocomposite. Based on the SAED, HRTEM measurements and data simulations, a monoclinic phase of hydroxyapatite (HAP) with a plate-like structure was obtained in the CPC system, which is believed to be responsible for the observed enhancement in CPC mechanical properties. The obtained composite has a biocompatibility comparable to that of commercial sample. PMID:27455626

  7. Are the High Hip Fracture Rates Among Norwegian Women Explained by Impaired Bone Material Properties?

    PubMed

    Duarte Sosa, Daysi; Vilaplana, Laila; Güerri, Roberto; Nogués, Xavier; Wang-Fagerland, Morten; Diez-Perez, Adolfo; F Eriksen, Erik

    2015-10-01

    Hip fracture rates in Norway rank among the highest in the world, more than double that of Spanish women. Previous studies were unable to demonstrate significant differences between the two populations with respect to bone mass or calcium metabolism. In order to test whether the difference in fracture propensity between both populations could be explained by differences in bone material quality we assessed bone material strength using microindentation in 42 Norwegian and 46 Spanish women with normal BMD values, without clinical or morphometric vertebral fractures, no clinical or laboratory signs of secondary osteoporosis, and without use of drugs with known influence on bone metabolism. Bone material properties were assessed by microindentation of the thick cortex of the mid tibia following local anesthesia of the area using the Osteoprobe device (Active Life Scientific, Santa Barbara, CA, USA). Indentation distance was standardized against a calibration phantom of methylmethacrylate and results, as percentage of this reference value, expressed as bone material strength index units (BMSi). We found that the bone material properties reflected in the BMSi value of Norwegian women was significantly inferior when compared to Spanish women (77 ± 7.1 versus 80.7 ± 7.8, p < 0.001). Total hip BMD was significantly higher in Norwegian women (1.218 g/cm(2) versus 0.938 g/cm(2) , p < 0.001) but regression analysis revealed that indentation values did not vary with BMD r(2)  = 0.03 or age r(2)  = 0.04. In conclusion Norwegian women show impaired bone material properties, higher bone mass, and were taller than Spanish women. The increased height will increase the impact on bone after falls, and impaired bone material properties may further enhance the risk fracture after such falls. These ethnic differences in bone material properties may partly explain the higher propensity for fracture in Norwegian women.

  8. Multiscale Homogenization Theory: An Analysis Tool for Revealing Mechanical Design Principles in Bone and Bone Replacement Materials

    NASA Astrophysics Data System (ADS)

    Hellmich, Christian; Fritsch, Andreas; Dormieux, Luc

    Biomimetics deals with the application of nature-made "design solutions" to the realm of engineering. In the quest to understand mechanical implications of structural hierarchies found in biological materials, multiscale mechanics may hold the key to understand "building plans" inherent to entire material classes, here bone and bone replacement materials. Analyzing a multitude of biophysical hierarchical and biomechanical experiments through homogenization theories for upscaling stiffness and strength properties reveals the following design principles: The elementary component "collagen" induces, right at the nanolevel, the mechanical anisotropy of bone materials, which is amplified by fibrillar collagen-based structures at the 100-nm scale, and by pores in the micrometer-to-millimeter regime. Hydroxyapatite minerals are poorly organized, and provide stiffness and strength in a quasi-brittle manner. Water layers between hydroxyapatite crystals govern the inelastic behavior of the nanocomposite, unless the "collagen reinforcement" breaks. Bone replacement materials should mimic these "microstructural mechanics" features as closely as possible if an imitation of the natural form of bone is desired (Gebeshuber et al., Adv Mater Res 74:265-268, 2009).

  9. Myocardial injection of apelin-overexpressing bone marrow cells improves cardiac repair via upregulation of Sirt3 after myocardial infarction.

    PubMed

    Li, Lanfang; Zeng, Heng; Hou, Xuwei; He, Xiaochen; Chen, Jian-Xiong

    2013-01-01

    Our previous study shows that treatment with apelin increases bone marrow cells (BMCs) recruitment and promotes cardiac repair after myocardial infarction (MI). The objective of this study was to investigate whether overexpression of apelin in BMCs improved cell therapy and accelerated cardiac repair and functional recovery in post-MI mice. Mouse myocardial infarction was achieved by coronary artery ligation and BMCs overexpressing apelin (apelin-BMCs) or GFP (GFP-BMCs) were injected into ischemic area immediately after surgery. In vitro, exposure of cultured BMCs to apelin led to a gradual increase in SDF-1á and CXCR4 expression. Intramyocardial delivery of apelin-BMCs in post-MI mice resulted in a significant increase number of APJ⁺/c-kit⁺/Sca1⁺ cells in the injected area compared to GFP-BMCs treated post-MI mice. Treatment with apelin-BMCs increased expression of VEGF, Ang-1 and Tie-2 in post-MI mice. Apelin-BMCs treatment also significantly increased angiogenesis and attenuated cardiac fibrosis formation in post-MI mice. Most importantly, treatment with apelin-BMCs significantly improved left ventricular (LV) systolic function in post-MI mice. Mechanistically, Apelin-BMCs treatment led to a significant increase in Sirtuin3 (Sirt3) expression and reduction of reactive oxygen species (ROS) formation. Treatment of cultured BMCs with apelin also increased Notch3 expression and Akt phosphorylation. Apelin treatment further attenuated stress-induced apoptosis whereas knockout of Sirt3 abolished anti-apoptotic effect of apelin in cultured BMCs. Moreover, knockout of Sirt3 significantly attenuated apelin-BMCs-induced VEGF expression and angiogenesis in post-MI mice. Knockout of Sirt3 further blunted apelin-BMCs-mediated improvement of cardiac repair and systolic functional recovery in post-MI mice. These data suggest that apelin improves BMCs therapy on cardiac repair and systolic function in post-MI mice. Upregulation of Sirt3 may contribute to the protective

  10. Bone repair with skeletal stem cells: rationale, progress to date and clinical application

    PubMed Central

    Jones, Elena A.; Giannoudis, Peter V.; Kouroupis, Dimitrios

    2016-01-01

    Bone marrow (BM) contains stem cells for both hematopoietic and nonhematopoietic lineages. Hematopoietic stem cells enable hematopoiesis to occur in a controlled manner in order to accurately compensate for the loss of short- as well as long-lived mature blood cells. The physiological role of nonhematopoietic BM stem cells, often referred to as multipotential stromal cells or skeletal stem cells (SSCs), is less understood. According to an authoritative current opinion, the main function of SSCs is to give rise to cartilage, bone, marrow fat and hematopoiesis-supportive stroma, in a specific sequence during embryonic and postnatal development. This review outlines recent advances in the understanding of origins and homeostatic functions of SSCs in vivo and highlights current and future SSC-based treatments for skeletal and joint disorders. PMID:27247633

  11. Repair of defects and osteosynthesis of long bones in children with osteoclastoma

    NASA Astrophysics Data System (ADS)

    Ryzhikov, D. V.; Gubina, E. V.; Podorozhnaya, V. T.; Senchenko, E. V.; Sadovoy, M. A.

    2016-08-01

    The paper is aimed at reporting a retrospective analysis covering the period from 2007 to 2015. The study involved 22 patients with benign osteoclastoma (OC), 14 male and 8 female children aged 9 to 19. All patients had monostotic lesions with the following location of pathological foci: humerus—11 patients, femoral bone—7, shin bone— 1, fibular bone—1, and ulnar bone—1. All 22 patients underwent surgery. Surgical treatment included resection of tumor focus within intact tissues (in cases of eccentric foci, bony bridge was preserved in the area of minimum damage, which was treated by electrocoagulation together with the cavity) together with bone grafting and intramedullary reinforcement of the affected bone (which provides stable osteosynthesis, early mobilization, and prevention of functional deficits in most patients). Consolidation was achieved in 100% of the operated patients.

  12. Bone repair with skeletal stem cells: rationale, progress to date and clinical application.

    PubMed

    Jones, Elena A; Giannoudis, Peter V; Kouroupis, Dimitrios

    2016-06-01

    Bone marrow (BM) contains stem cells for both hematopoietic and nonhematopoietic lineages. Hematopoietic stem cells enable hematopoiesis to occur in a controlled manner in order to accurately compensate for the loss of short- as well as long-lived mature blood cells. The physiological role of nonhematopoietic BM stem cells, often referred to as multipotential stromal cells or skeletal stem cells (SSCs), is less understood. According to an authoritative current opinion, the main function of SSCs is to give rise to cartilage, bone, marrow fat and hematopoiesis-supportive stroma, in a specific sequence during embryonic and postnatal development. This review outlines recent advances in the understanding of origins and homeostatic functions of SSCs in vivo and highlights current and future SSC-based treatments for skeletal and joint disorders.

  13. Comparing Gray and White Mineral Trioxide Aggregate as a Repair Material for Furcation Perforation: An in Vitro Dye Extraction Study

    PubMed Central

    Patel, Kiran; Baba, Suheel Manzoor; Jaiswal, Shikha; Venkataraghavan, Karthik; Jani, Mehul

    2014-01-01

    Introduction: Furcation perforation can have a negative impact on the prognosis of the affected tooth by compromising the attached apparatus. Hence these perforations require immediate repair. A variety of materials have been suggested for repair, of that MTA is the most promising material. The purpose of this study was to compare the ability of Gray and White MTA to seal furcation perforations using a dye extraction method under spectrophotometer. Materials and Methods: A total of 60 permanent mandibular molars were randomly divided into four experimental groups of 15 samples each as follows: Group A: Perforation repaired with White MTA. Group B: Perforation repaired with Gray MTA. Group C: Perforation left unsealed (positive). Group D: without perforation (negative). Dye extraction was performed using full concentration nitric acid. Dye absorbance was measured at 550 nm using spectrophotometer. The data analyzed using one-way-Anova Ratio and Unpaired t-test showing statistically significance difference among the groups. Result: It was seen that Group D samples without perforation showed least absorbance followed by Group A (perforation repaired with White MTA) and Group B (perforation repaired with Gray MTA). Group C (perforation left unsealed) showed highest absorbance. Conclusion: The White and Gray Mineral Trioxide Aggregate performed similarly as a furcation perforation repair material. There was no significant difference between the Gray MTA and White MTA. PMID:25478452

  14. Dynamic tensile material properties of human pelvic cortical bone.

    PubMed

    Kemper, Andrew R; McNally, Craig; Duma, Stefan M

    2008-01-01

    IIn order for finite element models of the human body to predict pelvic injuries accurately, the appropriate material properties must be applied. Therefore, the purpose of this study was to quantify the dynamic material properties of human pelvic cortical bone in tension. In order to accomplish this, a total of 20 tension coupon specimens were obtained from four regions of four human cadaver pelves: anterior ilium wing, posterior ilium wing, superior pubic ramus, and ischium body. For the anterior and posterior regions of the ilium wing, samples were taken in two orientations to investigate any direction dependence. A high-rate servo-hydraulic Material Testing System (MTS) with a custom slack adaptor was used to apply tension loads to failure at a constant loading rate of 0.5 strains/s. The horizontally oriented anterior ilium specimens were found to have a significantly larger ultimate stress (p=0.02), ultimate strain (p>0.01), and modulus (p=0.02) than the vertically oriented anterior ilium specimens. There were no significant differences in ultimate stress (p=0.27), ultimate strain (p=0.85), or modulus (p=0.87) found between horizontally oriented and vertically oriented posterior ilium specimens. However, additional testing should be conducted at specimen orientation 45 degree from the orientations used in the current study to further investigate the effect of specimen orientation on the posterior portion of the ilium wing. There were no significant differences in ultimate stress (p=0.79), ultimate strain (p=0.31), or modulus (p=0.15) found between the superior pubic ramus and ischium body specimens. However, the statistical comparison between superior pubic ramus and ischium body specimens was considered weak due to the limited samples and large variation between subjects. PMID:19141951

  15. Turbine repair process, repaired coating, and repaired turbine component

    SciTech Connect

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-09-01

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

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

    PubMed

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

    2015-09-01

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

  19. A platelet-rich plasma-based membrane as a periosteal substitute with enhanced osteogenic and angiogenic properties: a new concept for bone repair.

    PubMed

    El Backly, Rania M; Zaky, Samer H; Muraglia, Anita; Tonachini, Laura; Brun, Francesco; Canciani, Barbara; Chiapale, Danilo; Santolini, Federico; Cancedda, Ranieri; Mastrogiacomo, Maddalena

    2013-01-01

    The periosteum plays a pivotal role during bone development and repair contributing to bone vascularization and osteoprogenitor cells source. We propose a periosteal substitute engineered using a platelet-rich plasma (PRP) membrane incorporating autologous bone marrow-derived mesenchymal stem cells (PRP/BMSC gel membrane) to be wrapped around an osteoconductive scaffold for regeneration of compromised bone defects. The PRP/BMSC gel membrane was optimized using different compositions for optimal release of vascular endothelial growth factor (VEGF) and platelet derived growth factor-BB (PDGF-BB). Survival and proliferation of cells in the PRP gel membrane with time were confirmed in addition to their osteogenic capacity. Furthermore, to evaluate the possible effects of the PRP/BMSC gel membrane on surrounding progenitor cells in the injury area, we found that the PRP gel membrane products could significantly induce the migration of human endothelial cells in vitro, and increased the expression of bone morphogenetic protein 2 in cultured BMSC. These cells also secreted significant amounts of soluble proangiogenic factors, such as PDGF-BB, VEGF, and interleukin-8 (IL-8). Finally, the functionality of the PRP/BMSC gel membrane periosteal substitute for bone regeneration was tested in vivo both in an ectopic mouse model as well as in a rabbit segmental bone defect model providing evidence of its capacity to biomimic a periosteal response enhancing bone regeneration.

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

    PubMed

    Kulakov, A A; Grigor'ian, A S

    2014-01-01

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

  1. Molecular imaging to monitor repair of myocardial infarction using genetically engineered bone marrow-derived mesenchymal stem cells.

    PubMed

    Shi, Shuo; Zhang, Min; Guo, Rui; Miao, Ying; Zhang, Xiangming; Li, Biao

    2015-01-01

    Heart tissue has a diminished ability to repair after myocardial infarction (MI). Bone marrow- derived mesenchymal stem cells (BMSCs) have been used effectively to heal damaged tissue after MI. Hypoxia-inducible factor-1α (HIF-1α) can induce transcription of numerous pro-angiogenic genes and enhance stem cell survival. Here, we investigated whether HIF-1α-transduced BMSCs could enhance tissue repair after MI, and compared the value of micro-PET/CT and echocardiography for evaluation of therapeutic effects. Rat BMSCs were transduced with a lentivirus expressing HIF-1α and NIS (Lenti-HIF-1α-NIS). Sodium iodide symporter (NIS) functioned as effective reporter gene, allowing monitoring of BMSCs transplanted into the rat heart for up to 2 weeks using micro-SPECT/CT imaging. In a rat MI model, after transplantation of HIF-1α-NIS-transduced BMSCs to the MI zone, more expression of HIF-1α,VEGF and Ang-4, more improvement of metabolism, less fibrotic tissue and cardiomyocyte apoptosis were detected in the MI zone. Moreover, we found that most of the transplanted HIF-1α-NIS-transduced BMSCs differentiated into endothelial cells, and engineered new blood vessels in MI zone. Metabolic activity significantly increased at an early time point (2 weeks after transplantation) and lead to a sustained increase (4 weeks), as indicated by (18)F-FDG uptake in micro-PET/CT imaging. Echocardiography indicated no improvement in cardiac function at 2 weeks and small improvement at 4 weeks. This study indicated that (18)F-FDG micro-PET/CT was more useful for evaluating early therapeutic effects than echocardiography. PMID:25892408

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

    PubMed

    Babiker, Hassan

    2013-07-01

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

  3. Xenopus laevis as a novel model to study long bone critical-size defect repair by growth factor-mediated regeneration.

    PubMed

    Feng, Liang; Milner, Derek J; Xia, Chunguang; Nye, Holly L D; Redwood, Patrick; Cameron, Jo Ann; Stocum, David L; Fang, Nick; Jasiuk, Iwona

    2011-03-01

    We used the tarsus of an adult Xenopus laevis frog as an in vivo load-bearing model to study the regeneration of critical-size defects (CSD) in long bones. We found the CSD for this bone to be about 35% of the tarsus length. To promote regeneration, we implanted biocompatible 1,6 hexanediol diacrylate scaffolds soaked with bone morphogenetic proteins-4 and vascular endothelial growth factors. In contrast to studies that use scaffolds as templates for bone formation, we used scaffolds as a growth factor delivery vehicle to promote cartilage-to-bone regeneration. Defects in control frogs were filled with scaffolds lacking growth factors. The limbs were harvested at a series of time points ranging from 3 weeks to 6 months after implantation and evaluated using micro-computed tomography and histology. In frogs treated with growth factor-loaded scaffolds, we observed a cartilage-to-bone regeneration in the skeletal defect. Five out of eight defects were completely filled with cartilage by 6 weeks. Blood vessels had invaded the cartilage, and bone was beginning to form in ossifying centers. By 3 months, these processes were well advanced, and extensive ossification was observed in 6-month samples. In contrast, the defects in control frogs showed only formation of fibrous scar tissue. This study demonstrates the utility of a Xenopus model system for tissue engineering research and that the normal in vivo mechanism of endochondral bone development and fracture repair can be mimicked in the repair of CSD with scaffolds used as growth factor delivery mechanisms.

  4. Participation of MicroRNA-34a and RANKL on bone repair induced by poly(vinylidene-trifluoroethylene)/barium titanate membrane.

    PubMed

    Lopes, Helena B; Ferraz, Emanuela P; Almeida, Adriana L G; Florio, Pedro; Gimenes, Rossano; Rosa, Adalberto L; Beloti, Marcio M

    2016-09-01

    The poly(vinylidene-trifluoroethylene)/barium titanate (PVDF) membrane enhances in vitro osteoblast differentiation and in vivo bone repair. Here, we hypothesized that this higher bone repair could be also due to bone resorption inhibition mediated by a microRNA (miR)/RANKL circuit. To test our hypothesis, the large-scale miR expression of bone tissue grown on PVDF and polytetrafluoroethylene (PTFE) membranes was evaluated to identify potential RANKL-targeted miRs modulated by PVDF. The animal model used was rat calvarial defects implanted with either PVDF or PTFE. At 4 and 8 weeks, the bone tissue grown on membranes was submitted to a large-scale analysis of miRs by microarray. The expression of miR-34a and some of its targets, including RANKL, were evaluated by real-time polimerase chain reaction and osteoclast activity was detected by tartrate-resistant acid phosphatase (TRAP) staining. Among more than 250 miRs, twelve, including miR-34a, were simultaneously higher expressed (≥2 fold) at 4 and 8 weeks on PVDF. The higher expression of miR-34a was concomitant with a reduced expression of all its evaluated targets, including RANKL. Additionally, more TRAP-positive cells were observed in bone tissue grown on PTFE compared with PVDF in both time points. In conclusion, our results suggest that the higher bone formation induced by PVDF could be, at least in part, triggered by a miR-34a increase and RANKL decrease, which may inhibit osteoclast differentiation and activity, and bone resorption. PMID:27312544

  5. Extracorporeal shockwave enhanced regeneration of fibrocartilage in a delayed tendon-bone insertion repair model.

    PubMed

    Chow, Dick Ho Kiu; Suen, Pui Kit; Huang, Le; Cheung, Wing-Hoi; Leung, Kwok-Sui; Ng, Chun; Shi, San Qiang; Wong, Margaret Wan Nar; Qin, Ling

    2014-04-01

    Fibrous tissue is often formed in delayed healing of tendon bone insertion (TBI) instead of fibrocartilage. Extracorporeal shockwave (ESW) provides mechanical cues and upregulates expression of fibrocartilage-related makers and cytokines. We hypothesized that ESW would accelerate fibrocartilage regeneration at the healing interface in a delayed TBI healing model. Partial patellectomy with shielding at the TBI interface was performed on 32 female New Zealand White Rabbits for establishing this delayed TBI healing model. The rabbits were separated into the control and ESW group for evaluations at postoperative week 8 and 12. Shielding was removed at week 4 and a single ESW treatment was applied at week 6. Fibrocartilage regeneration was evaluated histomorphologically and immunohistochemically. Vickers hardness of the TBI matrix was measured by micro-indentation. ESW group showed higher fibrocartilage area, thickness, and proteoglycan deposition than the control in week 8 and 12. ESW increased expression of SOX9 and collagen II significantly in week 8 and 12, respectively. ESW group showed a gradual transition of hardness from bone to fibrocartilage to tendon, and had a higher Vickers hardness than the control group at week 12. In conclusion, ESW enhanced fibrocartilage regeneration at the healing interface in a delayed TBI healing model.

  6. Fabrication and characterization of novel biomimetic PLLA/cellulose/hydroxyapatite nanocomposite for bone repair applications.

    PubMed

    Eftekhari, Samin; El Sawi, Ihab; Bagheri, Zahra Shaghayegh; Turcotte, Ginette; Bougherara, Habiba

    2014-06-01

    The purpose of this research is to develop and characterize a novel biomimetic nanocomposite that closely mimics the properties of real bone such as morphology, composition and mechanical characteristics. This novel porous nanocomposite is composed of cotton-sourced cellulose microcrystals, hydroxyapatite nanoparticles and poly l-lactide acid. A unique combination of commonly used fabrication procedures has been developed including pre-treatment of particles using a coupling agent. The effect of various weight ratios of the reinforcing agents was evaluated to assess their influence on the chemical, thermal, and mechanical properties of the nanocomposites. The prepared nanocomposites were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and compression testing. Our results indicated the presence of molecular interactions between all components leading to an increase of the crystallinity of the polymer from 50% to 80%. Compression test results revealed that increasing the weight ratio of microcrystalline cellulose/poly l-lactide acid and hydroxyapatite/poly l-lactide acid from 0.1 to 0.5 enhanced the compressive yield stress from 0.127 to 2.2MPa and The Young's modulus from 6.6 to 38MPa, respectively. It was found that the fabricated nanocomposites are comparable with the trabecular bone from compositional, structural, and mechanical point of view. PMID:24863207

  7. Ultrasound-induced hyperthermia for the spatio-temporal control of gene expression in bone repair

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher; Padilla, Frédéric; Zhang, Man; Vilaboa, Nuria; Kripfgans, Oliver; Fowlkes, Brian; Franceschi, Renny

    2012-10-01

    Spatial and temporal control over the expression of growth/differentiation factors is of great interest for regeneration of bone, but technologies capable of providing tight and active control over gene expression remain elusive. We propose the use of focused ultrasound for the targeted activation of heat shock-sensitive expression systems in engineered bone. We report in vitro results with cells that express firefly luciferase (fLuc) under the control of a heat shock protein promoter. Cells were embedded in fibrin scaffolds and exposed to focused ultrasound, using a custom 3.3MHz transducer (focal length 4", f-number 1.33", focal dimension 1.2mm lateral FWHM) in CW mode for 2-20 minutes at intensities ISPTA=120-440 W/cm2. The kinetics of ultrasound-mediated activation of the cells was compared with that of strictly thermal activation. Bioluminescence imaging revealed fLuc expression in an area ≥2.5mm in diameter at the position of the ultrasound focus, and the diameter and intensity of the signal increased with the amplitude of the acoustic energy. We also found that ultrasound activated fLuc expression with substantially shorter exposures than thermal activation. Our results demonstrate the potential for focused ultrasound to selectively activate the expression of a gene of interest in an engineered tissue and suggest that focused ultrasound activates the heat shock pathway by a combination of thermal and non-thermal mechanisms.

  8. Enhancement of mechanical strength of TiO{sub 2}/high-density polyethylene composites for bone repair with silane-coupling treatment

    SciTech Connect

    Hashimoto, Masami . E-mail: masami@jfcc.or.jp; Takadama, Hiroaki . E-mail: takadama@jfcc.or.jp; Mizuno, Mineo . E-mail: mizuno@jfcc.or.jp; Kokubo, Tadashi . E-mail: kokubo@isc.chubu.ac.jp

    2006-03-09

    Mechanical properties of composites made up of high-density polyethylene (HDPE) and silanated TiO{sub 2} particles for use as a bone-repairing material were investigated in comparison with those of the composites of HDPE with unsilanized TiO{sub 2} particles. The interfacial morphology and interaction between silanated TiO{sub 2} and HDPE were analyzed by means of Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The absorption in spectral bands related to the carboxyl bond in the silane-coupling agent, the vinyl group in the HDPE, and the formation of the ether bond was studied in order to assess the influence of the silane-coupling agent. The SEM micrograph showed that the 'bridging effect' between HDPE and TiO{sub 2} was brought about by the silane-coupling agent. The use of the silane-coupling agent and the increase of the hot-pressing pressure for shaping the composites facilitated the penetration of polymer into cavities between individual TiO{sub 2} particles, which increased the density of the composite. Therefore, mechanical properties such as bending yield strength and Young's modulus increased from 49 MPa and 7.5 GPa to 65 MPa and 10 GPa, respectively, after the silane-coupling treatment and increase in the hot-pressing pressure.

  9. Three-Dimensional Changes of Maxilla after Secondary Alveolar Cleft Repair: Differences Between rhBMP-2 and Autologous Iliac Crest Bone Grafting

    PubMed Central

    Raposo-Amaral, Cassio Eduardo; Denadai, Rafael

    2015-01-01

    Background: Recombinant human bone morphogenetic protein (rhBMP)-2 has been used as an alternative to autologous bone transferring, a standard method of treatment. However, its potential adverse effect on anterior maxillary arch is unknown. Thus, the purpose of this study was to quantify sagittal and transversal changes of anterior maxilla after secondary alveolar cleft repair using traditional iliac crest bone grafting versus rhBMP-2. Methods: Twelve unilateral complete cleft lip and palate patients were randomly divided into 2 groups. In group 1, patients underwent traditional iliac crest bone grafting transferring (n = 4), and in group 2, patients underwent alveolar cleft reconstruction using collagen matrix with lyophilized rhBMP-2 (n = 8). Computed tomography (CT) imaging was performed preoperatively and at 1 year postoperatively, using a previously standardized protocol. A three-dimensional (3D) CT cephalometric analysis of the linear and angular measurements of the sagittal and transverse maxilla planes was performed to assess intra- and intergroup maxillary changes. Results: Intra- and intergroup comparisons of the pre- and postoperative 3D CT cephalometric linear and angular measurements of the sagittal and transverse maxilla planes showed no significant (all P > 0.05) differences among all studied variables. Conclusions: There were no significant anterior maxilla changes after maxillary cleft repair either using iliac crest bone grafting or rhBMP-2. PMID:26301140

  10. Short-term behaviour of two similar active glasses used as granules in the repair of bone defects.

    PubMed

    Gatti, A M; Zaffe, D

    1991-07-01

    The bioactivity of two similar vitreous materials used in the form of granules of 'critical' size was investigated in bone defects in jaws of two sheep. The granules consisted of Hench's Bioglass and another glass with the same chemical composition made in Italy. Two months after implantation, the sheep were killed and elemental analyses carried out on sections of the embedded jaws. The microanalyses for both the glasses showed a diffusion from the granules towards the surrounding tissue of silicon and sodium, and an inverse diffusion (from the surrounding tissue towards the granules) of calcium and phosphorus. The degradation for the Italian glass was slower than for the Bioglass. No significant osteoinduction was seen after that time at the interface of the glass granules or in the bone pocket. PMID:1892986

  11. Tensile behavior of cortical bone: dependence of organic matrix material properties on bone mineral content.

    PubMed

    Kotha, S P; Guzelsu, N

    2007-01-01

    A porous composite model is developed to analyze the tensile mechanical properties of cortical bone. The effects of microporosity (volksman's canals, osteocyte lacunae) on the mechanical properties of bone tissue are taken into account. A simple shear lag theory, wherein tensile loads are transferred between overlapped mineral platelets by shearing of the organic matrix, is used to model the reinforcement provided by mineral platelets. It is assumed that the organic matrix is elastic in tension and elastic-perfectly plastic in shear until it fails. When organic matrix shear stresses at the ends of mineral platelets reach their yield values, the stress-strain curve of bone tissue starts to deviate from linear behavior. This is referred as the microscopic yield point. At the point where the stress-strain behavior of bone shows a sharp curvature, the organic phase reaches its shear yield stress value over the entire platelet. This is referred as the macroscopic yield point. It is assumed that after macroscopic yield, mineral platelets cannot contribute to the load bearing capacity of bone and that the mechanical behavior of cortical bone tissue is determined by the organic phase only. Bone fails when the principal stress of the organic matrix is reached. By assuming that mechanical properties of the organic matrix are dependent on bone mineral content below the macroscopic yield point, the model is used to predict the entire tensile mechanical behavior of cortical bone for different mineral contents. It is found that decreased shear yield stresses and organic matrix elastic moduli are required to explain the mechanical behavior of bones with lowered mineral contents. Under these conditions, the predicted values (elastic modulus, 0.002 yield stress and strain, and ultimate stress and strain) are within 15% of experimental data.

  12. Tensile behavior of cortical bone: dependence of organic matrix material properties on bone mineral content.

    PubMed

    Kotha, S P; Guzelsu, N

    2007-01-01

    A porous composite model is developed to analyze the tensile mechanical properties of cortical bone. The effects of microporosity (volksman's canals, osteocyte lacunae) on the mechanical properties of bone tissue are taken into account. A simple shear lag theory, wherein tensile loads are transferred between overlapped mineral platelets by shearing of the organic matrix, is used to model the reinforcement provided by mineral platelets. It is assumed that the organic matrix is elastic in tension and elastic-perfectly plastic in shear until it fails. When organic matrix shear stresses at the ends of mineral platelets reach their yield values, the stress-strain curve of bone tissue starts to deviate from linear behavior. This is referred as the microscopic yield point. At the point where the stress-strain behavior of bone shows a sharp curvature, the organic phase reaches its shear yield stress value over the entire platelet. This is referred as the macroscopic yield point. It is assumed that after macroscopic yield, mineral platelets cannot contribute to the load bearing capacity of bone and that the mechanical behavior of cortical bone tissue is determined by the organic phase only. Bone fails when the principal stress of the organic matrix is reached. By assuming that mechanical properties of the organic matrix are dependent on bone mineral content below the macroscopic yield point, the model is used to predict the entire tensile mechanical behavior of cortical bone for different mineral contents. It is found that decreased shear yield stresses and organic matrix elastic moduli are required to explain the mechanical behavior of bones with lowered mineral contents. Under these conditions, the predicted values (elastic modulus, 0.002 yield stress and strain, and ultimate stress and strain) are within 15% of experimental data. PMID:16434048

  13. Hypoxia-mimicking bioactive glass/collagen glycosaminoglycan composite scaffolds to enhance angiogenesis and bone repair.

    PubMed

    Quinlan, Elaine; Partap, Sonia; Azevedo, Maria M; Jell, Gavin; Stevens, Molly M; O'Brien, Fergal J

    2015-06-01

    One of the biggest challenges in regenerative medicine is promoting sufficient vascularisation of tissue-engineered constructs. One approach to overcome this challenge is to target the cellular hypoxia inducible factor (HIF-1α) pathway, which responds to low oxygen concentration (hypoxia) and results in the activation of numerous pro-angiogenic genes including vascular endothelial growth factor (VEGF). Cobalt ions are known to mimic hypoxia by artificially stabilising the HIF-1α transcription factor. Here, resorbable bioactive glass particles (38 μm and 100 μm) with cobalt ions incorporated into the glass network were used to create bioactive glass/collagen-glycosaminoglycan scaffolds optimised for bone tissue engineering. Inclusion of the bioactive glass improved the compressive modulus of the resulting composite scaffolds while maintaining high degrees of porosity (>97%). Moreover, in vitro analysis demonstrated that the incorporation of cobalt bioactive glass with a mean particle size of 100 μm significantly enhanced the production and expression of VEGF in endothelial cells, and cobalt bioactive glass/collagen-glycosaminoglycan scaffold conditioned media also promoted enhanced tubule formation. Furthermore, our results prove the ability of these scaffolds to support osteoblast cell proliferation and osteogenesis in all bioactive glass/collagen-glycosaminoglycan scaffolds irrespective of the particle size. In summary, we have developed a hypoxia-mimicking tissue-engineered scaffold with pro-angiogenic and pro-osteogenic capabilities that may encourage bone tissue regeneration and overcome the problem of inadequate vascularisation of grafts commonly seen in the field of tissue engineering.

  14. Immunohistochemistry staining for mismatch repair proteins: the endoscopic biopsy material provides useful and coherent results.

    PubMed

    Vilkin, Alex; Leibovici-Weissman, Ya'ara; Halpern, Marisa; Morgenstern, Sara; Brazovski, Eli; Gingold-Belfer, Rachel; Wasserberg, Nir; Brenner, Baruch; Niv, Yaron; Sneh-Arbib, Orly; Levi, Zohar

    2015-11-01

    Immunohistochemistry (IHC) testing for mismatch repair proteins (MMRP) in patients with colorectal cancer can be performed on endoscopic biopsy material or the surgical resection material. Data are continuing to accumulate regarding the deleterious effect of neoadjuvant chemoradiation on MMRP expression. However, despite continuing rise in the use of endoscopic biopsies for IHC, most pathology departments still use mainly the surgical materials for IHC testing. In this study we compared the quality of stains among 96 colon cancer subjects with paired endoscopic and surgical material available for MLH1, MSH2, MSH6, and PMS2 stains (96 × 4, yielding 384 paired stains). Each slide received both a quantitative score (immunoreactivity [0-3] × percent positivity [0-4]) and a qualitative score (absent; weak and focal; strong). The quantitative scores of all MMRP were significantly higher among the endoscopic material (P<.001 for all). In 358 pairs (93.2%), both the endoscopic and operative material stained either strong (322, 83.9%) or absent (36, 9.4%). In 26 pairs (6.8%), the endoscopic material stained strong, whereas the operative material stained focal and weak. No endoscopic biopsy materials stained focal and weak. Our findings indicate that the biopsy material may provide more coherent results. Although these results may indicate that biopsy material provides coherent and useful results, it is yet to be determined if the demonstrated differences pose a real clinical problem in interpreting final results of IHC staining of such kind. Hence, we suggest that when available, the endoscopic material rather than the operative one should serve as the primary substrate for IHC staining.

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

    SciTech Connect

    Herlin, Maria; Finnilä, Mikko A.J.; Zioupos, Peter; Aula, Antti; Risteli, Juha; Miettinen, Hanna M.; Jämsä, Timo; Tuukkanen, Juha; Korkalainen, Merja; Håkansson, Helen; Viluksela, Matti

    2013-11-15

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

  16. Comprehensive analysis of repair/reinforcement materials for polymethyl methacrylate denture bases: mechanical and dimensional stability characteristics.

    PubMed

    Venkat, R; Gopichander, N; Vasantakumar, M

    2013-12-01

    Fracture of complete denture is a common problem as acrylic resins hold inherent limitations. This necessitates affirmation of a selection criterion by evaluating the critical requirements of repair materials. The study intended to evaluate mechanical properties and dimensional stability of common denture base repair and reinforcement materials under standard experimental protocol. Seven types of denture reinforcement materials were chosen. Forty cuboidal samples were made in accordance with ISO 178 for three point bending test and divided to eight groups of five samples each. One group acted as control and samples of seven groups were sectioned and repaired with chosen materials. Five mechanical properties-fracture load, deflection, flexural strength, fracture toughness and elastic modulus were evaluated for all groups. Forty mandibular complete denture specimens were utilized for evaluating fracture load and deflection under loading. Dimensional stability after repair with seven different repair materials was analyzed in two planes (Linear and curvilinear) utilizing separate set of denture samples. Heat cure polymethyl methacrylate with polyethylene fiber was affirmed as material of choice based on this study as it accomplishes the most critical norms of requirement.

  17. MicroRNA-26a-modified adipose-derived stem cells incorporated with a porous hydroxyapatite scaffold improve the repair of bone defects

    PubMed Central

    WANG, ZHENLIN; ZHANG, DAWEI; HU, ZHIQIANG; CHENG, JIWEI; ZHUO, CHUANMENG; FANG, XIANCONG; XING, YONGMING

    2015-01-01

    Tissue-engineered bone substitutes are frequently used to repair bone defects. Adipose-derived stem cells (ASCs) are a promising source of cells for repairing bone tissue, however, insufficient osteogenic potency remains the main obstacle for their application. The present study aimed to enhance the osteogenic potency of ASCs by transfection of microRNA (miR)-26a, a novel osteogenic and angiogenic promoting miRNA. An inverted fluorescence microscope was used to observe transfection efficiency, while a scanning electron microscope was used to detect morphological alterations. Cell proliferation was monitored continuously for 7 days using a Cell Counting kit-8 assay. Osteogenic differentiation was determined by reverse transcription quantitative polymerase chain reaction, alkaline phosphatase (ALP) staining, collagen secretion and extracellular matrix (ECM) mineralization. ASCs were incorporated with a porous hydroxyapatite (HA) scaffold to create a novel tissue-engineered bone substitute and inserted into the critical tibia defect of rats. New bone formation was evaluated by hematoxylin and eosin and Masson's trichrome staining. The results demonstrated that miR-26a was successfully delivered into the cytoplasm, while the morphology and proliferation of ASCs were not significantly altered. Osteogenic-associated genes were markedly upregulated and ALP production, collagen secretion and ECM mineralization were all increased following transfection of miR-26a. Histological evaluation demonstrated that the modified cells accompanied with a porous HA scaffold markedly promoted new bone formation within the defective area. In conclusion, miR-26a transfection significantly improved the osteogenic potency of ASCs suggesting that modified ASCs incorporated with a HA scaffold may be used as a potential bone substitute. PMID:25997460

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

    PubMed

    Beutel, Bryan G; Danna, Natalie R; Gangolli, Riddhi; Granato, Rodrigo; Manne, Lakshmiprada; Tovar, Nick; Coelho, Paulo G

    2014-12-01

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

  19. Repair of Segmental Load-Bearing Bone Defect by Autologous Mesenchymal Stem Cells and Plasma-Derived Fibrin Impregnated Ceramic Block Results in Early Recovery of Limb Function

    PubMed Central

    Ng, Min Hwei; Duski, Suryasmi; Tan, Kok Keong; Yusof, Mohd Reusmaazran; Low, Kiat Cheong; Mohamed Rose, Isa; Mohamed, Zahiah; Bin Saim, Aminuddin; Idrus, Ruszymah Bt Hj

    2014-01-01

    Calcium phosphate-based bone substitutes have not been used to repair load-bearing bone defects due to their weak mechanical property. In this study, we reevaluated the functional outcomes of combining ceramic block with osteogenic-induced mesenchymal stem cells and platelet-rich plasma (TEB) to repair critical-sized segmental tibial defect. Comparisons were made with fresh marrow-impregnated ceramic block (MIC) and partially demineralized allogeneic bone block (ALLO). Six New Zealand White female rabbits were used in each study group and three rabbits with no implants were used as negative controls. By Day 90, 4/6 rabbits in TEB group and 2/6 in ALLO and MIC groups resumed normal gait pattern. Union was achieved significantly faster in TEB group with a radiological score of 4.50 ± 0.78 versus ALLO (1.06 ± 0.32), MIC (1.28 ± 0.24), and negative controls (0). Histologically, TEB group scored the highest percentage of new bone (82% ± 5.1%) compared to ALLO (5% ± 2.5%) and MIC (26% ± 5.2%). Biomechanically, TEB-treated tibiae achieved the highest compressive strength (43.50 ± 12.72 MPa) compared to those treated with ALLO (15.15 ± 3.57 MPa) and MIC (23.28 ± 6.14 MPa). In conclusion, TEB can repair critical-sized segmental load-bearing bone defects and restore limb function. PMID:25165699

  20. Design Requirements for Annulus Fibrosus Repair: Review of Forces, Displacements, and Material Properties of the Intervertebral Disk and a Summary of Candidate Hydrogels for Repair.

    PubMed

    Long, Rose G; Torre, Olivia M; Hom, Warren W; Assael, Dylan J; Iatridis, James C

    2016-02-01

    There is currently a lack of clinically available solutions to restore functionality to the intervertebral disk (IVD) following herniation injury to the annulus fibrosus (AF). Microdiscectomy is a commonly performed surgical procedure to alleviate pain caused by herniation; however, AF defects remain and can lead to accelerated degeneration and painful conditions. Currently available AF closure techniques do not restore mechanical functionality or promote tissue regeneration, and have risk of reherniation. This review determined quantitative design requirements for AF repair materials and summarized currently available hydrogels capable of meeting these design requirements by using a series of systematic PubMed database searches to yield 1500+ papers that were screened and analyzed for relevance to human lumbar in vivo measurements, motion segment behaviors, and tissue level properties. We propose a testing paradigm involving screening tests as well as more involved in situ and in vivo validation tests to efficiently identify promising biomaterials for AF repair. We suggest that successful materials must have high adhesion strength (∼0.2 MPa), match as many AF material properties as possible (e.g., approximately 1 MPa, 0. 3 MPa, and 30 MPa for compressive, shear, and tensile moduli, respectively), and have high tensile failure strain (∼65%) to advance to in situ and in vivo validation tests. While many biomaterials exist for AF repair, few undergo extensive mechanical characterization. A few hydrogels show promise for AF repair since they can match at least one material property of the AF while also adhering to AF tissue and are capable of easy implantation during surgical procedures to warrant additional optimization and validation.

  1. Arc Jet Screening Tests Of Phase 1 Orbiter Tile Repair Materials and Uncoated RSI High Temperature Emittance Measurements

    NASA Technical Reports Server (NTRS)

    DelPapa, Steven V.

    2005-01-01

    Arc jet tests of candidate tile repair materials and baseline Orbiter uncoated reusable surface insulation (RSI) were performed in the Johnson Space Center's (JSC) Atmospheric Reentry Materials and Structures Evaluation Facility (ARMSEF) from June 23, 2003, through August 19, 2003. These tests were performed to screen candidate tile repair materials by verifying the high temperature performance and determining the thermal stability. In addition, tests to determine the surface emissivity at high temperatures and the geometric shrinkage of bare RSI were performed. In addition, tests were performed to determine the surface emissivity at high temperatures and the geometric shrinkage of uncoated RSI.

  2. Frontal sinus and skull bone defect obliteration with three synthetic bioactive materials. A comparative study.

    PubMed

    Peltola, Matti J; Aitasalo, Kalle M J; Suonpää, Jouko T K; Yli-Urpo, Antti; Laippala, Pekka J; Forsback, Ari-Pekka

    2003-07-15

    Three synthetic bioactive materials were studied in an experimental model to compare their usability in a frontal sinus and a skull bone defect obliteration. Bioactive glass number 9 (BAG(1)), bioactive glass number 13 (BAG(2)), and hydroxyapatite (HA) granules were investigated. BAG(1) and HA granules have been previously tested clinically. The clinical usefulness of BAG(2) granules has not been tested. Upper bony walls of 45 Elco rabbits' frontal sinuses were drilled open from four separate holes with the use of a standard method. The skull bone defects and the sinuses in frontal bone were filled with BAG(1) or BAG(2) on one side, and with HA on the other side. Two parallel posterior defects were covered with a pedicled periosteum flap, and two anterior defects with a free flap. The resorption of materials, new bone, and fibrous-tissue formation were observed with a histomorphometric method at 1, 3, and 6 months postoperatively. Scanning-electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were done at 6 months. In histomorphometry, the new bone formation increased with all the investigated materials throughout the study (p < 0.001), but the results showed higher new bone formation in the defects filled with BAG(1) than in corresponding BAG(2)- or HA- filled defects. New bone formation and resorption of materials were faster in defects covered by pedicled than by free periosteum flaps (p < 0.001). Intimate contact between the used materials and new bone was confirmed by SEM. FTIR analysis of bone produced by BAG(1) and BAG(2) was of the same type as natural frontal bone. BAG(2) can be manufactured in various shapes, and thus, could possibly be used in clinical conditions requiring a special anatomical implant shape. However, more research is needed regarding this property of BAG(2).

  3. Insulin-like growth factor-1 suspended in hyaluronan improves cartilage and subchondral cancellous bone repair in osteoarthritis of temporomandibular joint.

    PubMed

    Liu, X-W; Hu, J; Man, C; Zhang, B; Ma, Y-Q; Zhu, S-S

    2011-02-01

    This study sought to evaluate the effects of intra-articular injection of insulin-like growth factor-1 (IGF-1) suspended in hyaluronan (HA) on the cartilage and subchondral cancellous bone repair in osteoarthritis (OA) of the temporomandibular joint (TMJ). Disc perforation was performed bilaterally in rabbit TMJs to induce OA. Four groups of animals (n=12) received OA induction only, and either intra-articular HA injection alone, intra-articular IGF-1 injection alone, or a combination of HA and IGF-1 injection. All therapy was begun 4 weeks after OA induction. The animals were killed 12 or 24 weeks after the first injection, for histology and micro-CT examinations. Two additional animals were used as normal controls. Typical cartilage and subchondral cancellous bone lesions were observed in the OA group. No protective effect on cartilage and subchondral cancellous bone was found in the HA or IGF-1 alone groups. Better histological repair and nearly normal micro-architectural properties of the subchondral cancellous bone were observed in the HA+IGF-1 group compared with the HA or IGF-1 alone groups. HA may be used as an effective carrier for intra-articular injection of IGF-1 and the combination of HA/IGF-1 shows promise as a new rational approach to therapy of TMJ OA. PMID:21055904

  4. Development of Flexible Capacitive Ultrasound Transducers and the Use of Ultrasound for Bone Repair

    NASA Astrophysics Data System (ADS)

    Wentzell, Scott A.

    devices have the potential to mediate both bone resorption and deposition, and also provide a new functional system for generating ultrasound on the irregular surfaces encountered in clinical settings.

  5. Systemic treatment with strontium ranelate accelerates the filling of a bone defect and improves the material level properties of the healing bone.

    PubMed

    Zacchetti, Giovanna; Dayer, Romain; Rizzoli, René; Ammann, Patrick

    2014-01-01

    Rapid bone defect filling with normal bone is a challenge in orthopaedics and dentistry. Strontium ranelate (SrRan) has been shown to in vitro decrease bone resorption and increase bone formation, and represents a potential agent with the capacity to accelerate bone defect filling. In this study, bone tibial defects of 2.5 mm in diameter were created in 6-month-old female rats orally fed SrRan (625 mg/kg/d; 5/7 days) or vehicle for 4, 8, or 12 weeks (10 rats per group per time point) from the time of surgery. Tibias were removed. Micro-architecture was determined by micro-computed tomography (µCT) and material level properties by nanoindentation analysis. µCT analysis showed that SrRan administration significantly improved microarchitecture of trabecular bone growing into the defect after 8 and 12 weeks of treatment compared to vehicle. SrRan treatment also accelerated the growth of cortical bone over the defect, but with different kinetics compared to trabecular bone, as the effects were already significant after 4 weeks. Nanoindentation analysis demonstrated that SrRan treatment significantly increased material level properties of both trabecular bone and cortical bone filling the defect compared to vehicle. SrRan accelerates the filling of bone defect by improving cortical and trabecular bone microarchitecture both quantitatively and qualitatively. PMID:25243150

  6. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone spectral imaging.

    PubMed

    Huh, Sun; Lee, Heon

    2014-01-01

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition.

  7. Effects of a buried magnetic field on cranial bone reconstruction in rats

    PubMed Central

    de ABREU, Maíra Cavallet; PONZONI, Deise; LANGIE, Renan; ARTUZI, Felipe Ernesto; PURICELLI, Edela

    2016-01-01

    ABSTRACT The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts. PMID:27119765

  8. Bone

    NASA Astrophysics Data System (ADS)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

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

  9. Culture human mesenchymal stem cells with calcium phosphate cement scaffolds for bone repair.

    PubMed

    Weir, Michael D; Xu, Hockin H K

    2010-04-01

    Because of its moldability and excellent osteoconductivity, calcium phosphate cement (CPC) is highly promising for craniofacial and orthopedic applications. The objectives of this study were to investigate the response of human mesenchymal stem cells (hMSCs) to a high-strength CPC-chitosan scaffold and to examine cell proliferation and osteogenic differentiation. hMSCs were seeded onto CPC-chitosan composite, CPC control, and tissue culture polystyrene (TCPS). Alkaline phosphatase activity (ALP) and mineralization of hMSCs were measured. CPC-chitosan had a flexural strength (mean + or - SD; n = 5) of (19.5 + or - 1.4) MPa, higher than (8.0 + or - 1.4) MPa of CPC control (p < 0.05). The percentage of live hMSCs on CPC-chitosan was (90.5 + or - 1.3)% at 8 days, matching (90.7 + or - 3.8)% of CPC control (p > 0.1). The CPC-chitosan surface area covered by the attached hMSCs increased from (51 + or - 11)% at 1 day to (90 + or - 4)% at 8 days (p < 0.05), matching those of CPC control (p > 0.1). Hence, the CPC strength was significantly increased via chitosan without compromising the hMSC response. At 8 days, there was a significant increase in ALP of cells in osteogenic media (10.99 + or - 0.93) [(mM pNpp/min)/(microg DNA)] versus control media (3.62 + or - 0.40) (p < 0.05). hMSCs in osteogenic media exhibited greater mineralization area of (47.5 + or - 19.7)% compared with (6.1 + or - 2.3)% in control medium on TCPS (p < 0.05). In conclusion, hMSCs showed excellent attachment and viability on the strong and tough CPC-chitosan scaffold, matching the hMSC response on CPC control. hMSCs were successfully differentiated down the osteogenic lineage. Hence, the strong, in situ hardening CPC-chitosan scaffold may be useful as a moderate load-bearing vehicle to deliver hMSCs for maxillofacial and orthopedic bone tissue engineering. PMID:20091907

  10. Development of candidate reference materials for the measurement of lead in bone

    PubMed Central

    Hetter, Katherine M.; Bellis, David J.; Geraghty, Ciaran; Todd, Andrew C.; Parsons, Patrick J.

    2010-01-01

    The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of 2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis. PMID:18421443

  11. Improved quality of cartilage repair by bone marrow mesenchymal stem cells for treatment of an osteochondral defect in a cynomolgus macaque model

    PubMed Central

    Araki, Susumu; Imai, Shinji; Ishigaki, Hirohito; Mimura, Tomohiro; Nishizawa, Kazuya; Ueba, Hiroaki; Kumagai, Kousuke; Kubo, Mitsuhiko; Mori, Kanji; Ogasawara, Kazumasa; Matsusue, Yoshitaka

    2015-01-01

    Background and purpose Integration of repaired cartilage with surrounding native cartilage is a major challenge for successful tissue-engineering strategies of cartilage repair. We investigated whether incorporation of mesenchymal stem cells (MSCs) into the collagen scaffold improves integration and repair of cartilage defects in a cynomolgus macaque model. Methods Cynomolgus macaque bone marrow-derived MSCs were isolated and incorporated into type-I collagen gel. Full-thickness osteochondral defects (3 mm in diameter, 5 mm in depth) were created in the patellar groove of 36 knees of 18 macaques and were either left untreated (null group, n = 12), had collagen gel alone inserted (gel group, n = 12), or had collagen gel incorporating MSCs inserted (MSC group, n = 12). After 6, 12, and 24 weeks, the cartilage integration and tissue response were evaluated macroscopically and histologically (4 null, 4 gel, and 4 MSC knees at each time point). Results The gel group showed most cartilage-rich reparative tissue covering the defect, owing to formation of excessive cartilage extruding though the insufficient subchondral bone. Despite the fact that a lower amount of new cartilage was produced, the MSC group had better-quality cartilage with regular surface, seamless integration with neighboring naïve cartilage, and reconstruction of trabecular subchondral bone. Interpretation Even with intensive investigation, MSC-based cell therapy has not yet been established in experimental cartilage repair. Our model using cynomolgus macaques had optimized conditions, and the method using MSCs is superior to other experimental settings, allowing the possibility that the procedure might be introduced to future clinical practice. PMID:25175660

  12. Combination of calcium sulfate and simvastatin-controlled release microspheres enhances bone repair in critical-sized rat calvarial bone defects.

    PubMed

    Fu, Yin-Chih; Wang, Yan-Hsiung; Chen, Chung-Hwan; Wang, Chih-Kuang; Wang, Gwo-Jaw; Ho, Mei-Ling

    2015-01-01

    Most allogenic bone graft substitutes have only osteoconductive properties. Developing new strategies to improve the osteoinductive activity of bone graft substitutes is both critical and practical for clinical application. Previously, we developed novel simvastatin-encapsulating poly(lactic-co-glycolic acid) microspheres (SIM/PLGA) that slowly release simvastatin and enhance fracture healing. In this study, we combined SIM/PLGA with a rapidly absorbable calcium sulfate (CS) bone substitute and studied the effect on bone healing in critical-sized calvarial bone defects in a rat model. The cytotoxicity and cytocompatibility of this combination was tested in vitro using lactate dehydrogenase leakage and a cell attachment assay, respectively. Combination treatment with SIM/PLGA and the CS bone substitute had no cytotoxic effect on bone marrow stem cells. Compared with the control, cell adhesion was substantially enhanced following combination treatment with SIM/PLGA and the CS bone substitute. In vivo, implantation of the combination bone substitute promoted healing of critical-sized calvarial bone defects in rats; furthermore, production of bone morphogenetic protein-2 and neovascularization were enhanced in the area of the defect. In summary, the combination of SIM/PLGA and a CS bone substitute has osteoconductive and osteoinductive properties, indicating that it could be used for regeneration of bone in the clinical setting. PMID:26664114

  13. Combination of calcium sulfate and simvastatin-controlled release microspheres enhances bone repair in critical-sized rat calvarial bone defects

    PubMed Central

    Fu, Yin-Chih; Wang, Yan-Hsiung; Chen, Chung-Hwan; Wang, Chih-Kuang; Wang, Gwo-Jaw; Ho, Mei-Ling

    2015-01-01

    Most allogenic bone graft substitutes have only osteoconductive properties. Developing new strategies to improve the osteoinductive activity of bone graft substitutes is both critical and practical for clinical application. Previously, we developed novel simvastatin-encapsulating poly(lactic-co-glycolic acid) microspheres (SIM/PLGA) that slowly release simvastatin and enhance fracture healing. In this study, we combined SIM/PLGA with a rapidly absorbable calcium sulfate (CS) bone substitute and studied the effect on bone healing in critical-sized calvarial bone defects in a rat model. The cytotoxicity and cytocompatibility of this combination was tested in vitro using lactate dehydrogenase leakage and a cell attachment assay, respectively. Combination treatment with SIM/PLGA and the CS bone substitute had no cytotoxic effect on bone marrow stem cells. Compared with the control, cell adhesion was substantially enhanced following combination treatment with SIM/PLGA and the CS bone substitute. In vivo, implantation of the combination bone substitute promoted healing of critical-sized calvarial bone defects in rats; furthermore, production of bone morphogenetic protein-2 and neovascularization were enhanced in the area of the defect. In summary, the combination of SIM/PLGA and a CS bone substitute has osteoconductive and osteoinductive properties, indicating that it could be used for regeneration of bone in the clinical setting. PMID:26664114

  14. Cartilage Repair and Subchondral Bone Remodeling in Response to Focal Lesions in a Mini-Pig Model: Implications for Tissue Engineering

    PubMed Central

    Fisher, Matthew B.; Belkin, Nicole S.; Milby, Andrew H.; Henning, Elizabeth A.; Bostrom, Marc; Kim, Minwook; Pfeifer, Christian; Meloni, Gregory; Dodge, George R.; Burdick, Jason A.; Schaer, Thomas P.; Steinberg, David R.

    2015-01-01

    Objective: Preclinical large animal models are essential for evaluating new tissue engineering (TE) technologies and refining surgical approaches for cartilage repair. Some preclinical animal studies, including the commonly used minipig model, have noted marked remodeling of the subchondral bone. However, the mechanisms underlying this response have not been well characterized. Thus, our objective was to compare in-vivo outcomes of chondral defects with varied injury depths and treatments. Design: Trochlear chondral defects were created in 11 Yucatan minipigs (6 months old). Groups included an untreated partial-thickness defect (PTD), an untreated full-thickness defect (FTD), and FTDs treated with microfracture, autologous cartilage transfer (FTD-ACT), or an acellular hyaluronic acid hydrogel. Six weeks after surgery, micro-computed tomography (μCT) was used to quantitatively assess defect fill and subchondral bone remodeling. The quality of cartilage repair was assessed using the ICRS-II histological scoring system and immunohistochemistry for type II collagen. A finite element model (FEM) was developed to assess load transmission. Results: Using μCT, substantial bone remodeling was observed for all FTDs, but not for the PTD group. The best overall histological scores and greatest type II collagen staining was found for the FTD-ACT and PTD groups. The FEM confirmed that only the FTD-ACT group could initially restore appropriate transfer of compressive loads to the underlying bone. Conclusions: The bony remodeling observed in this model system appears to be a biological phenomena and not a result of altered mechanical loading, with the depth of the focal chondral defect (partial vs. full thickness) dictating the bony remodeling response. The type of cartilage injury should be carefully controlled in studies utilizing this model to evaluate TE approaches for cartilage repair. PMID:25318414

  15. Mineralized polymer composites as biogenic bone substitute material

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  16. Stimulation of bone repair with ultrasound: a review of the possible mechanic effects.

    PubMed

    Padilla, Frédéric; Puts, Regina; Vico, Laurence; Raum, Kay

    2014-07-01

    dish walls and the formation of standing waves will greatly affect the local type and amplitude of the stimulus exerted on the cells. A future engineering challenge is therefore the design of dedicated experimental set-ups, in which the different mechanical phenomena induced by ultrasound can be controlled. This is a prerequisite to evaluate the biological effects of the different phenomena with respect to particular parameters, like intensity, frequency, or duty cycle. By relating the variations of these parameters to the induced physical effects and to the biological responses, it will become possible to derive an 'acoustic dose' and propose a quantification and cross-calibration of the different experimental systems. Improvements in bone healing management will probably also come from a combination of ultrasound with a 'biologic' components, e.g. growth factors, scaffolds, gene therapies, or drug delivery vehicles, the effects of which being potentiated by the ultrasound.

  17. Ceramic and non-ceramic hydroxyapatite as a bone graft material: a brief review.

    PubMed

    Dutta, S R; Passi, D; Singh, P; Bhuibhar, A

    2015-03-01

    Treatment of dental, craniofacial and orthopedic defects with bone graft substitutes has shown promising result achieving almost complete bone regeneration depending on product resorption similar to human bone's physicochemical and crystallographic characteristics. Among these, non-ceramic and ceramic hydroxyapatite being the main inorganic salt of bone is the most studied calcium phosphate material in clinical practices ever since 1970s and non-ceramic since 1985. Its "chemical similarity" with the mineralized phase of biologic bone makes it unique. Hydroxyapatite as an excellent carrier of osteoinductive growth factors and osteogenic cell populations is also useful as drug delivery vehicle regardless of its density. Porous ceramic and non-ceramic hydroxyapatite is osteoconductive, biocompatible and very inert. The need for bone graft material keeps on increasing with increased age of the population and the increased conditions of trauma. Recent advances in genetic engineering and doping techniques have made it possible to use non-ceramic hydroxyapatite in larger non-ceramic crystals and cluster forms as a successful bone graft substitute to treat various types of bone defects. In this paper we have mentioned some recently studied properties of hydroxyapatite and its various uses through a brief review of the literatures available to date. PMID:25428698

  18. Retrospective dosimetry using OSL of tooth enamel and dental repair materials irradiated under wet and dry conditions.

    PubMed

    Geber-Bergstrand, Therése; Bernhardsson, Christian; Mattsson, Sören; Rääf, Christopher L

    2012-11-01

    Following a radiological or nuclear emergency event, there is a need for quick and reliable dose estimations of potentially exposed people. In situations where dosimeters are not readily available, the dose estimations must be carried out using alternative methods. In the present study, the optically stimulated luminescence (OSL) properties of tooth enamel and different dental repair materials have been examined. Specimens of the materials were exposed to gamma and beta radiation in different types of liquid environments to mimic the actual irradiation situation in the mouth. Measurements were taken using a Risø TL/OSL reader, and irradiations were made using a (90)Sr/(90)Y source and a linear accelerator (6 MV photons). Results show that the OSL signal from tooth enamel decreases substantially when the enamel is kept in a wet environment. Thus, tooth enamel is not reliable for retrospective dose assessment without further studies of the phenomenon. Dental repair materials, on the other hand, do not exhibit the same effect when exposed to liquids. In addition, dose-response and fading measurements of the dental repair materials show promising results, making these materials highly interesting for retrospective dosimetry. The minimum detectable dose for the dental repair materials has been estimated to be 20-185 mGy. PMID:22972601

  19. Use of buccal fat pad to repair post-extraction peri-implant bone defects in the posterior maxilla. A preliminary prospective study

    PubMed Central

    Peñarrocha-Diago, María; Alonso-González, Rocío; Aloy-Prósper, Amparo; Peñarrocha-Oltra, David; Camacho, Fabio; Peñarrocha-Diago, Miguel

    2015-01-01

    Background Extensive literature exists about the use of the BFP in the treatment of oral defects but, to our knowledge, no article refers to the use of the BFP as a substitute of the membrane barriers for treatment of peri-implant bone defects. The aim was to evaluate the use of the buccal fat pad as a coating material for bone grafting in the peri-implant bone defect regeneration of immediate implants placed in the posterior maxilla. Material and Methods A preliminary prospective study of patients involving immediate implants in which the buccal fat pad was used as a coating material to peri-implant bone defects was carried out. The outcome measures assessed were: postoperative pain and swelling, complications related to buccal fat pad surgery, implant survival and success rates and peri-implant marginal bone loss at 12 months of prosthetic loading. Results Twenty-seven patients (17 women and 10 men) with a mean age of 55.3 ± 8.9 years, and a total of 43 implants were included. Two-thirds of the patients reported either no pain or only mild intensity pain and moderate inflammation, two days after surgery. Post-operative period was well tolerated by the patients and no serious complications occurred. None wound dehiscence occurred. Implant survival and success rates were 97.6% and the average marginal bone loss 1 year after loading was 0.58 ± 0.27 mm. Conclusions Within the limits of this preliminary study, the use of the buccal fat pad as a coating material for bone grafting in peri-implant bone defects placed in the upper posterior maxilla was a well-tolerated technique by patients; high implant success rate was achieved with a minimal peri-implant marginal bone loss at 12 months of prosthetic loading. Key words:Buccal fat pad, immediate implant, peri-implant bone defect. PMID:26241450

  20. Low-Magnitude High-Frequency Mechanical Signals Accelerate and Augment Endochondral Bone Repair: Preliminary Evidence of Efficacy

    PubMed Central

    Goodship, Allen E.; Lawes, Timothy J.; Rubin, Clinton T.

    2010-01-01

    Fracture healing can be enhanced by load bearing, but the specific components of the mechanical environment which can augment or accelerate the process remain unknown. The ability of low-magnitude, high-frequency mechanical signals, anabolic in bone tissue, are evaluated here for their ability to influence fracture healing. The potential for short duration (17 min), extremely low-magnitude (25 μm), high-frequency (30 Hz) interfragmentary displacements to enhance fracture healing was evaluated in a mid-diaphyseal, 3-mm osteotomy of the sheep tibia. In a pilot study of proof of concept and clinical relevance, healing in osteotomies stabilized with rigid external fixation (Control: n = 4), were compared to the healing status of osteotomies with the same stiffness of fixation, but supplemented with daily mechanical loading (Experimental: n = 4). These 25-μm displacements, induced by a ferroactive shape-memory alloy (“smart” material) incorporated into the body of the external fixator, were less than 1% of the 3-mm fracture gap, and less than 6% of the 0.45-mm displacement measured at the site during ambulation (p <0.001). At 10-weeks post-op, the callus in the Experimental group was 3.6-fold stiffer (p <0.03), 2.5-fold stronger (p =0.05), and 29% larger (p <0.01) than Controls. Bone mineral content was 52% greater in the Experimental group (p <0.02), with a 2.6-fold increase in bone mineral content (BMC) in the region of the periosteum (p <0.001). These data reinforce the critical role of mechanical factors in the enhancement of fracture healing, and emphasize that the signals need not be large to be influential and potentially clinically advantageous to the restoration of function. PMID:19117066

  1. Bacterial Leakage of Mineral Trioxide Aggregate, Calcium-Enriched Mixture and Biodentine as Furcation Perforation Repair Materials in Primary Molars

    PubMed Central

    Ramazani, Nahid; Sadeghi, Parisa

    2016-01-01

    Introduction: Adequate seal of iatrogenically perforated area within the root canal system can improve the long term treatment prognosis. This in vitro study evaluated the sealing ability of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement and Biodentine in repair of furcation perforation in primary molars. Methods and Materials: A total of 61 freshly extracted primary mandibular second molars were randomly divided into three groups (n=17) and 10 teeth were put in negative (without perforation, n=5) and positive (perforated without repair, n=5) control groups. Turbidity was used as the criteria of bacterial leakage, when detected in the model of dual-chamber leakage. Data were analyzed using the Chi-Square and Kaplan-Meier survival analysis in SPSS software. The level of significance was set at 0.05. Results: All positive samples showed turbidity, whereas none of the negative samples allowed bacterial leakage. There was no significant difference between the number of turbidity samples in repaired teeth with all test materials (P=0.13). No significant difference was also detected in the mean survival time (P>0.05). Conclusion: CEM cement and Biodentine showed promising results as perforation repair materials and can be recommended as suitable alternatives of MTA for repair of furcation perforation of primary molars. PMID:27471534

  2. Mechanical Properties of Mesh Materials Used for Hernia Repair and Soft Tissue Augmentation

    PubMed Central

    Pott, Peter P.; Schwarz, Markus L. R.; Gundling, Ralf; Nowak, Kai; Hohenberger, Peter; Roessner, Eric D.

    2012-01-01

    Background Hernia repair is the most common surgical procedure in the world. Augmentation with synthetic meshes has gained importance in recent decades. Most of the published work about hernia meshes focuses on the surgical technique, outcome in terms of mortality and morbidity and the recurrence rate. Appropriate biomechanical and engineering terminology is frequently absent. Meshes are under continuous development but there is little knowledge in the public domain about their mechanical properties. In the presented experimental study we investigated the mechanical properties of several widely available meshes according to German Industrial Standards (DIN ISO). Methodology/Principal Findings Six different meshes were assessed considering longitudinal and transverse direction in a uni-axial tensile test. Based on the force/displacement curve, the maximum force, breaking strain, and stiffness were computed. According to the maximum force the values were assigned to the groups weak and strong to determine a base for comparison. We discovered differences in the maximum force (11.1±6.4 to 100.9±9.4 N/cm), stiffness (0.3±0.1 to 4.6±0.5 N/mm), and breaking strain (150±6% to 340±20%) considering the direction of tension. Conclusions/Significance The measured stiffness and breaking strength vary widely among available mesh materials for hernia repair, and most of the materials show significant anisotropy in their mechanical behavior. Considering the forces present in the abdominal wall, our results suggest that some meshes should be implanted in an appropriate orientation, and that information regarding the directionality of their mechanical properties should be provided by the manufacturers. PMID:23071685

  3. [A review of research on the application of small intestinal submucosa in repairing osteoarticular injury].

    PubMed

    Guo, Qi; Li, Chun-bao; Shen, Xue-zhen; Qu, Feng; Lu, Xi; Liu, Yu-jie

    2016-05-01

    The ideal treatment and recovery of osteoarticular injury remain to be resolved. Small intestinal submucosa (SIS), a naturally-occurring decellularized extracellular matrix, has been recognized as an ideal scaffold for tissue engineering and widely used in repairing various tissues and organs. Nowadays its application has also been gradually increased in the field of orthopedics. We reviewed laboratorial studies and clinical trails about the application of SIS in bone and joint repair, aiming to evaluate its effects on the repair of bone, cartilage, meniscus, ligament and tendon. SIS has showed promising results in repairing bone, meniscus, ligament or tendon. However, additional studies will be required to further evaluate its effects on articular cartilage and tendon-bone healing. How to optimize SIS material,is also a focused problem concerned with making SIS a potential therapeutic option with high value for orthopedic tissue repair. PMID:27505971

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

    PubMed

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

    2013-01-01

    The purpose of this study was to investigate the processes of regeneration of bone tissue after the introduction of new implant systems. In the experiment, performed on 10 male pigs of Landras breed aged 50-55 days and weighing 17-18.5 kg, the time course of histological changes was studied in the area of mandibular regeneration after the formation of tissue defect and the introduction of the implant of a proposed construction. Morphological analysis of the experimental results 90, 180 and 270 days after the operation demonstrated the process of reparative regeneration of damaged bone along implant-bone block boundaries. Bone repair proceeded through the stage of formation of the woven bone with its progressive substitution by the lamellar bone, with the maintenance of the shape, size and symmetry of the damaged organ. PMID:23805619

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

    PubMed

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

    2013-01-01

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

  6. Comparison of the radiopacities of different root-end filling and repair materials.

    PubMed

    Tanalp, Jale; Karapınar-Kazandağ, Meriç; Dölekoğlu, Semanur; Kayahan, Mehmet Baybora

    2013-01-01

    This study evaluated the radiopacity of 3 repair materials, Biodentine, MM-MTA, and MTA Angelus. Standardized cylindrical rings were prepared. Samples of Biodentine MM-MTA and MTA Angelus were prepared (n = 10 in each group), filled into the rings, and preserved at 37°C until setting. A 1 mm thick dentin slice was used as control. All set specimens were removed and radiographed along with the dentine slice and a graduated aluminium step wedge. Digital images were transferred to the computer using a software. The radiographic densities of the specimens were determined, and the values were converted into millimetres of aluminium (mm Al). One-way ANOVA was used for intergroup comparison, whereas Tukey HSD test was used for detecting the group with the difference. The mean radiopacities of Biodentine, MTA Angelus, and MM-MTA were 2.8 ± 0.48, 4.72 ± 0.45, and 5.18 ± 0.51 mm Al, respectively. The radiopacity of Biodentine was significantly lower compared to other materials (P = 0.001), whereas no significant difference was noted between MTA Angelus and MM-MTA (P = 0.109). All materials had significantly higher radiopacities compared to dentine. The relatively lower radiopacity of Biodentine can be improved to achieve more reliable results in procedures such as retrograde fillings.

  7. Comparison of the Radiopacities of Different Root-End Filling and Repair Materials

    PubMed Central

    Tanalp, Jale; Karapınar-Kazandağ, Meriç; Kayahan, Mehmet Baybora

    2013-01-01

    This study evaluated the radiopacity of 3 repair materials, Biodentine, MM-MTA, and MTA Angelus. Standardized cylindrical rings were prepared. Samples of Biodentine MM-MTA and MTA Angelus were prepared (n = 10 in each group), filled into the rings, and preserved at 37°C until setting. A 1 mm thick dentin slice was used as control. All set specimens were removed and radiographed along with the dentine slice and a graduated aluminium step wedge. Digital images were transferred to the computer using a software. The radiographic densities of the specimens were determined, and the values were converted into millimetres of aluminium (mm Al). One-way ANOVA was used for intergroup comparison, whereas Tukey HSD test was used for detecting the group with the difference. The mean radiopacities of Biodentine, MTA Angelus, and MM-MTA were 2.8 ± 0.48, 4.72 ± 0.45, and 5.18 ± 0.51 mm Al, respectively. The radiopacity of Biodentine was significantly lower compared to other materials (P = 0.001), whereas no significant difference was noted between MTA Angelus and MM-MTA (P = 0.109). All materials had significantly higher radiopacities compared to dentine. The relatively lower radiopacity of Biodentine can be improved to achieve more reliable results in procedures such as retrograde fillings. PMID:24260018

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

    PubMed

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

    2014-02-01

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

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

    PubMed

    Blob, Richard W; Snelgrove, Jason M

    2006-09-01

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

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

    PubMed

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

    2016-10-01

    The G171V mutation in the low-density lipoprotein receptor-related protein 5 (LRP5) leads to a high bone mass (HBM) phenotype. Studies using HBM transgenic mouse models have consistently found increased bone mass and whole-bone strength, but little attention has been paid to the composition of the bone matrix. The current study sought to determine if the cortical bone matrix composition differs in HBM and wild-type mice and to determine how much of the variance in bone material properties is explained by variance in matrix composition. Consistent with previous studies, HBM mice had greater cortical area, moment of inertia, ultimate force, bending stiffness, and energy to failure than wild-type animals. The increased energy to failure was primarily caused by a large increase in post-yield behavior, with no difference in pre-yield behavior. The HBM mice had increased mineral-to-matrix and collagen cross-link ratios, and decreased crystallinity, carbonate, and acid phosphate substitution as measured by Fourier transform infrared microspectroscopy, but no differences in crystal length, intra-fibular strains, and mineral spacing compared to wild-type controls, as measured by X-ray scattering. The largest between genotype difference in material properties was a twofold increase in the modulus of toughness in HBM mice. Step-wise regression analyses showed that the specific matrix compositional parameters most closely associated with material properties varied between the wild-type and HBM genotypes. Although the mechanisms controlling the paradoxical combination of more mineralized yet tougher bone in HBM mice remain to be fully explained, the findings suggest that LRP5 represents a target to not only build bone mass but also to improve bone quality. PMID:27230741

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

    PubMed

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

    2016-10-01

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

  12. Biocompatibility and bone-repairing effects: comparison between porous poly-lactic-co-glycolic acid and nano-hydroxyapatite/poly(lactic acid) scaffolds.

    PubMed

    Zong, Chen; Qian, Xiaodan; Tang, Zihua; Hu, Qinghong; Chen, Jiarong; Gao, Changyou; Tang, Ruikang; Tong, Xiangmin; Wang, Jinfu

    2014-06-01

    Copolymer composite scaffolds and bioceramic/polymer composite scaffolds are two representative forms of composite scaffolds used for bone tissue engineering. Studies to compare biocompatibility and bone-repairing effects between these two scaffolds are significant for selecting or improving the scaffold for clinical application. We prepared two porous scaffolds comprising poly-lactic-acid/poly-glycolic-acid (PLGA) and poly-lactic-acid/nano-hydroxyapatite (nHAP/PLA) respectively, and examined their biocompatibility with human bone marrow-derived mesenchymal stem cells (hMSCs) through evaluating adhesion, proliferation and osteogenic differentiation potentials of hMSCs in the scaffold. Then, the PLGA scaffold with hMSCs (PM construct) and the nHAP/PLA scaffold with hMSCs (HPM construct) were transplanted into the rat calvarial defect areas to compare their effects on the bone reconstruction. The results showed that the nHAP/PLA scaffold was in favor of adhesion, matrix deposition and osteogenic differentiation of hMSCs. For in vivo transplantation, both HPM and PM constructs led to mineralization and osteogenesis in the defect area of rat. However, the area grafted with PM construct showed a better formation of mature bone than that with HPM construct. In addition, the evaluation of in vitro and in vivo degradation indicated that the degradation rate of nHAP/PLA scaffold was much lower than that of PLGA scaffold. It is inferred that the lower degradation of nHAP/PLA scaffold should result in its inferior bone reconstruction in rat calvaria. Therefore, the preparation of an ideal composite scaffold for bone tissue engineering should be taken into account of the balance between its biocompatibility, degradation rate, osteoconductivity and mechanical property.

  13. [Use of bioactive glass ceramic material Biociyal-11 - experimental substantiation for jaw bone defects replacement].

    PubMed

    Bezzubik, S D; Grechukha, A M

    2009-01-01

    Pequliarities of morphologic osseous reparation of jaw bone defects in 15 non-bred dogs after implantation of different forms of glass crystal material Biocital-11 and blood clot on 7, 14, 21, 30 and 180th day after operation were shown. High biocompatibility of the material Biocital-11 with expressed osseous conductive function was disclosed.

  14. Bone regeneration and stem cells

    PubMed Central

    Arvidson, K; Abdallah, B M; Applegate, L A; Baldini, N; Cenni, E; Gomez-Barrena, E; Granchi, D; Kassem, M; Konttinen, Y T; Mustafa, K; Pioletti, D P; Sillat, T; Finne-Wistrand, A

    2011-01-01

    Abstract This invited review covers research areas of central importance for orthopaedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and foetal stem cells, effects of sex steroids on mesenchymal stem cells, use of platelet-rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed. PMID:21129153

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-10-01

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

  17. Suture materials affect peri-implant bone healing and implant osseointegration.

    PubMed

    Villa, Oscar; Lyngstadaas, Staale P; Monjo, Marta; Satué, Maria; Rønold, Hans J; Petzold, Christiane; Wohlfahrt, Johan C

    2015-09-01

    The aim of this study was to evaluate the effects of the remnants of two suture materials on osseointegration of titanium implants in a rabbit tibial model. Calibrated defects were prepared in the tibia of five Chinchilla rabbits. Filaments of nonresorbable (NR) nylon or resorbable (R) chitosan were placed at the bone to implant interface, whereas control sites had no suture material. After a healing period of 4 weeks, a pull-out test procedure was performed followed by enzymatic analyses of the wound fluid and relative quantification of mRNA levels for bone-related and cytokine markers from the peri-implant bone. A trend toward a reduced pull-out force was observed in the NR group (NR: 23.0 ± 12.8 N; R: 33.9 ± 11.3 N; control: 33.6 ± 24.0 N). Similarly, the bone resorption marker vacuolar type H+-ATPase was increased in the NR group compared with that in the control group (P = 0.041). The R group showed trends for lower alkaline phosphatase activity and osteocalcin expression and higher total protein content and RNA compared with the control group. In this submerged healing model, peri-implant bone healing was marginally affected by the two suture materials tested. However, there was a tendency toward better osseointegration and lower expression of bone resorption markers in the R group compared with the control group.

  18. Suture materials affect peri-implant bone healing and implant osseointegration.

    PubMed

    Villa, Oscar; Lyngstadaas, Staale P; Monjo, Marta; Satué, Maria; Rønold, Hans J; Petzold, Christiane; Wohlfahrt, Johan C

    2015-09-01

    The aim of this study was to evaluate the effects of the remnants of two suture materials on osseointegration of titanium implants in a rabbit tibial model. Calibrated defects were prepared in the tibia of five Chinchilla rabbits. Filaments of nonresorbable (NR) nylon or resorbable (R) chitosan were placed at the bone to implant interface, whereas control sites had no suture material. After a healing period of 4 weeks, a pull-out test procedure was performed followed by enzymatic analyses of the wound fluid and relative quantification of mRNA levels for bone-related and cytokine markers from the peri-implant bone. A trend toward a reduced pull-out force was observed in the NR group (NR: 23.0 ± 12.8 N; R: 33.9 ± 11.3 N; control: 33.6 ± 24.0 N). Similarly, the bone resorption marker vacuolar type H+-ATPase was increased in the NR group compared with that in the control group (P = 0.041). The R group showed trends for lower alkaline phosphatase activity and osteocalcin expression and higher total protein content and RNA compared with the control group. In this submerged healing model, peri-implant bone healing was marginally affected by the two suture materials tested. However, there was a tendency toward better osseointegration and lower expression of bone resorption markers in the R group compared with the control group. PMID:26369486

  19. Evaluation of bone repair in the femur of rats submitted to laser therapy in different wavelengths: An image segmentation method of analysis

    NASA Astrophysics Data System (ADS)

    Queiroga, A. S.; Sousa, F. B.; Araújo, J. M. S.; Santos, S. D.; Sousa, C. D'f. S.; Quintans, T. C.; Almeida, T. P.; Nonaka, C. F. W.; Batista, L. V.; Limeira Junior, F. A.

    2008-09-01

    The aim of this study was to histologically assess the effect of laser therapy (LILT, 660 and 780 nm) on the repair of standardized bone defects on the femur of Wistar albinus rats. The sample was composed of 12 Wistar albinus young adult rats of both genders. Three randomized groups were studied: group I (control, n = 4), group II (LILT, 660 nm, n = 4), and group III (LILT, 780 nm, n = 4). Samples were prepared using a bone defect on the left-side femur surface of the animals, with a total dimension of approximately 3 mm3. Groups II and III were irradiated every 48 h from the second application, where the first dose was given immediately after surgery and the second application came 24 h after surgery. The irradiations were applied transcutaneously at four points around the wound for 14 days. At each point, a dose of 50 J/cm2 (2 J) was given ( s ˜ 0.04 cm2, 40 mW) and the total dose per session was 200 J/cm2 (8 J). The sacrifices were made 15 days after surgery and the specimens were routinely processed to wax, serially cut, stained with an H&E stain, and analyzed under light microscopy. The images were submitted to morphometric analysis using the image segmentation method using the K-means algorithm. The data obtained through the morphometric analysis were submitted to statistical analysis using the Tukey test. The results showed that the group treated with laser therapy in the infrared spectrum resulted in an increase in the repair of bone defects when compared with the group treated with the laser in the red spectrum and control group, which, in turn, had a very similar pattern of repair. A statistical significance ( p < 0.01) was observed when comparing the results of group III and the results of Groups I and II. We concluded that the LILT in the infrared spectrum produced a positive biomodulation effect on the repair of bone defects in the femur of rats.

  20. Strength and Density of Geopolymer Mortar Cured at Ambient Temperature for Use as Repair Material

    NASA Astrophysics Data System (ADS)

    Warid Wazien, A. Z.; Bakri Abdullah, Mohd Mustafa Al; Abd. Razak, Rafiza; Mohd Remy Rozainy, M. A. Z.; Faheem Mohd Tahir, Muhammad

    2016-06-01

    Geopolymers produced by synthesizing aluminosilicate source materials with an alkaline activator solution promised an excellent properties akin to the existing construction material. This study focused on the effect of various binder to sand ratio on geopolymer mortar properties. Mix design of geopolymer mortar was produced using NaOH concentration of 12 molars, ratio of fly ash/alkaline activator and ratio Na2SiO3/NaOH of 2.0 and 2.5 respectively. Samples subsequently ware cured at ambient temperature. The properties of geopolymer mortar were analysed in term of compressive strength and density at different period which are on the 3rd and 7th day of curing. Experimental results revealed that the addition of sand slightly increase the compressive strength of geopolymer. The optimum compressive strength obtained was up to 31.39 MPa on the 7th day. The density of geopolymer mortar was in the range between 2.0 g/cm3 to 2.23 g/cm3. Based on this findings, the special properties promoted by geopolymer mortar display high potential to be implemented in the field of concrete patch repair.

  1. Structural performance of notch damaged steel beams repaired with composite materials

    NASA Astrophysics Data System (ADS)

    El-Taly, Boshra

    2016-06-01

    An experimental program and an analytical model using ANSYS program were employed to estimate the structural performance of repaired damaged steel beams using fiber reinforced polymer (FRP) composite materials. The beams were artificially notched in the tension flanges at mid-spans and retrofitted by FRP flexible sheets on the tension flanges and the sheets were extended to cover parts of the beams webs with different heights. Eleven box steel beams, including one intact beam, one notch damaged beam and nine notches damaged beam and retrofitted with composite materials, were tested in two-point loading up to failure. The parameters considered were the FRP type (GFRP and CFRP) and number of layers. The results indicated that bonding CFRP sheets to both of the tension steel flange and part of the webs, instead of the tension flange only, enhances the ultimate load of the retrofitted beams, avoids the occurrence of the debonding and increases the beam ductility. Also the numerical models give acceptable results in comparison with the experimental results.

  2. High-strength mineralized collagen artificial bone

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    Yan, Ling; Jiang, Dian-ming

    2015-01-01

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

  4. Evaluation of OSSIFI® as Alloplastic Bone Graft Material in Treatment of Periodontal Infrabony Defects

    PubMed Central

    Kaushal, Sumit; Kapoor, Anoop; Singh, Preetinder; Kochhar, Gulsheen; Khuller, Nitin

    2014-01-01

    Introduction: The shift in therapeutic concepts from resection to regeneration has significantly impacted the practice of periodontology. Human studies have revealed that hydroxyapatite bone cement holds great promise as a grafting alloplastic material. Aims and Objectives: To evaluate the efficacy of OSSIFI® (combined beta tricalcium phosphate plus hydroxyapatite) in the treatment of periodontal infrabony defects. Materials and Methods: Ten study subjects were selected and divided into two groups. Group I (PD>7mm) and Group II (PD≤ 7mm). Both Groups I and II were treated by regenerative periodontal surgery using OSSIFI® as graft material. Plaque index, gingival index, pocket depth, clinical attachment levels were recorded clinically and bone fill, radiographically, at baseline, three months and six months. Results and Conclusion: Statistically significant reduction in pocket depth, plaque index, gingival index was seen after six months. There was significant bone fill seen from 3-6months with significant gain in clinical attachment levels. PMID:25478450

  5. Pulsed electromagnetic fields promote osteogenesis and osseointegration of porous titanium implants in bone defect repair through a Wnt/β-catenin signaling-associated mechanism.

    PubMed

    Jing, Da; Zhai, Mingming; Tong, Shichao; Xu, Fei; Cai, Jing; Shen, Guanghao; Wu, Yan; Li, Xiaokang; Xie, Kangning; Liu, Juan; Xu, Qiaoling; Luo, Erping

    2016-01-01

    Treatment of osseous defects remains a formidable clinical challenge. Porous titanium alloys (pTi) have been emerging as ideal endosseous implants due to the excellent biocompatibility and structural properties, whereas inadequate osseointegration poses risks for unreliable long-term implant stability. Substantial evidence indicates that pulsed electromagnetic fields (PEMF), as a safe noninvasive method, inhibit osteopenia/osteoporosis experimentally and clinically. We herein investigated the efficiency and potential mechanisms of PEMF on osteogenesis and osseointegration of pTi in vitro and in vivo. We demonstrate that PEMF enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton for in vitro osteoblasts seeded in pTi. PEMF promoted gene expressions in Runx2, OSX, COL-1 and Wnt/β-catenin signaling. PEMF-stimulated group exhibited higher Runx2, Wnt1, Lrp6 and β-catenin protein expressions. In vivo results via μCT and histomorphometry show that 6-week and 12-week PEMF promoted osteogenesis, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defect. PEMF promoted femoral gene expressions of Runx2, BMP2, OCN and Wnt/β-catenin signaling. Together, we demonstrate that PEMF improve osteogenesis and osseointegration of pTi by promoting skeletal anabolic activities through a Wnt/β-catenin signaling-associated mechanism. PEMF might become a promising biophysical modality for enhancing the repair efficiency and quality of pTi in bone defect. PMID:27555216

  6. Pulsed electromagnetic fields promote osteogenesis and osseointegration of porous titanium implants in bone defect repair through a Wnt/β-catenin signaling-associated mechanism

    PubMed Central

    Jing, Da; Zhai, Mingming; Tong, Shichao; Xu, Fei; Cai, Jing; Shen, Guanghao; Wu, Yan; Li, Xiaokang; Xie, Kangning; Liu, Juan; Xu, Qiaoling; Luo, Erping

    2016-01-01

    Treatment of osseous defects remains a formidable clinical challenge. Porous titanium alloys (pTi) have been emerging as ideal endosseous implants due to the excellent biocompatibility and structural properties, whereas inadequate osseointegration poses risks for unreliable long-term implant stability. Substantial evidence indicates that pulsed electromagnetic fields (PEMF), as a safe noninvasive method, inhibit osteopenia/osteoporosis experimentally and clinically. We herein investigated the efficiency and potential mechanisms of PEMF on osteogenesis and osseointegration of pTi in vitro and in vivo. We demonstrate that PEMF enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton for in vitro osteoblasts seeded in pTi. PEMF promoted gene expressions in Runx2, OSX, COL-1 and Wnt/β-catenin signaling. PEMF-stimulated group exhibited higher Runx2, Wnt1, Lrp6 and β-catenin protein expressions. In vivo results via μCT and histomorphometry show that 6-week and 12-week PEMF promoted osteogenesis, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defect. PEMF promoted femoral gene expressions of Runx2, BMP2, OCN and Wnt/β-catenin signaling. Together, we demonstrate that PEMF improve osteogenesis and osseointegration of pTi by promoting skeletal anabolic activities through a Wnt/β-catenin signaling-associated mechanism. PEMF might become a promising biophysical modality for enhancing the repair efficiency and quality of pTi in bone defect. PMID:27555216

  7. Effect of low-level mechanical vibration on osteogenesis and osseointegration of porous titanium implants in the repair of long bone defects

    NASA Astrophysics Data System (ADS)

    Jing, Da; Tong, Shichao; Zhai, Mingming; Li, Xiaokang; Cai, Jing; Wu, Yan; Shen, Guanghao; Zhang, Xuhui; Xu, Qiaoling; Guo, Zheng; Luo, Erping

    2015-11-01

    Emerging evidence substantiates the potential of porous titanium alloy (pTi) as an ideal bone-graft substitute because of its excellent biocompatibility and structural properties. However, it remains a major clinical concern for promoting high-efficiency and high-quality osseointegration of pTi, which is beneficial for securing long-term implant stability. Accumulating evidence demonstrates the capacity of low-amplitude whole-body vibration (WBV) in preventing osteopenia, whereas the effects and mechanisms of WBV on osteogenesis and osseointegration of pTi remain unclear. Our present study shows that WBV enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton of primary osteoblasts in pTi. WBV upregulated osteogenesis-associated gene and protein expression in primary osteoblasts, including OCN, Runx2, Wnt3a, Lrp6 and β-catenin. In vivo findings demonstrate that 6-week and 12-week WBV stimulated osseointegration, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defects via μCT, histological and histomorphometric analyses. WBV induced higher ALP, OCN, Runx2, BMP2, Wnt3a, Lrp6 and β-catenin, and lower Sost and RANKL/OPG gene expression in rabbit femora. Our findings demonstrate that WBV promotes osteogenesis and osseointegration of pTi via its anabolic effect and potential anti-catabolic activity, and imply the promising potential of WBV for enhancing the repair efficiency and quality of pTi in osseous defects.

  8. Effect of low-level mechanical vibration on osteogenesis and osseointegration of porous titanium implants in the repair of long bone defects.

    PubMed

    Jing, Da; Tong, Shichao; Zhai, Mingming; Li, Xiaokang; Cai, Jing; Wu, Yan; Shen, Guanghao; Zhang, Xuhui; Xu, Qiaoling; Guo, Zheng; Luo, Erping

    2015-11-25

    Emerging evidence substantiates the potential of porous titanium alloy (pTi) as an ideal bone-graft substitute because of its excellent biocompatibility and structural properties. However, it remains a major clinical concern for promoting high-efficiency and high-quality osseointegration of pTi, which is beneficial for securing long-term implant stability. Accumulating evidence demonstrates the capacity of low-amplitude whole-body vibration (WBV) in preventing osteopenia, whereas the effects and mechanisms of WBV on osteogenesis and osseointegration of pTi remain unclear. Our present study shows that WBV enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton of primary osteoblasts in pTi. WBV upregulated osteogenesis-associated gene and protein expression in primary osteoblasts, including OCN, Runx2, Wnt3a, Lrp6 and β-catenin. In vivo findings demonstrate that 6-week and 12-week WBV stimulated osseointegration, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defects via μCT, histological and histomorphometric analyses. WBV induced higher ALP, OCN, Runx2, BMP2, Wnt3a, Lrp6 and β-catenin, and lower Sost and RANKL/OPG gene expression in rabbit femora. Our findings demonstrate that WBV promotes osteogenesis and osseointegration of pTi via its anabolic effect and potential anti-catabolic activity, and imply the promising potential of WBV for enhancing the repair efficiency and quality of pTi in osseous defects.

  9. Effect of low-level mechanical vibration on osteogenesis and osseointegration of porous titanium implants in the repair of long bone defects

    PubMed Central

    Jing, Da; Tong, Shichao; Zhai, Mingming; Li, Xiaokang; Cai, Jing; Wu, Yan; Shen, Guanghao; Zhang, Xuhui; Xu, Qiaoling; Guo, Zheng; Luo, Erping

    2015-01-01

    Emerging evidence substantiates the potential of porous titanium alloy (pTi) as an ideal bone-graft substitute because of its excellent biocompatibility and structural properties. However, it remains a major clinical concern for promoting high-efficiency and high-quality osseointegration of pTi, which is beneficial for securing long-term implant stability. Accumulating evidence demonstrates the capacity of low-amplitude whole-body vibration (WBV) in preventing osteopenia, whereas the effects and mechanisms of WBV on osteogenesis and osseointegration of pTi remain unclear. Our present study shows that WBV enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton of primary osteoblasts in pTi. WBV upregulated osteogenesis-associated gene and protein expression in primary osteoblasts, including OCN, Runx2, Wnt3a, Lrp6 and β-catenin. In vivo findings demonstrate that 6-week and 12-week WBV stimulated osseointegration, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defects via μCT, histological and histomorphometric analyses. WBV induced higher ALP, OCN, Runx2, BMP2, Wnt3a, Lrp6 and β-catenin, and lower Sost and RANKL/OPG gene expression in rabbit femora. Our findings demonstrate that WBV promotes osteogenesis and osseointegration of pTi via its anabolic effect and potential anti-catabolic activity, and imply the promising potential of WBV for enhancing the repair efficiency and quality of pTi in osseous defects. PMID:26601709

  10. Pulsed electromagnetic fields promote osteogenesis and osseointegration of porous titanium implants in bone defect repair through a Wnt/β-catenin signaling-associated mechanism.

    PubMed

    Jing, Da; Zhai, Mingming; Tong, Shichao; Xu, Fei; Cai, Jing; Shen, Guanghao; Wu, Yan; Li, Xiaokang; Xie, Kangning; Liu, Juan; Xu, Qiaoling; Luo, Erping

    2016-08-24

    Treatment of osseous defects remains a formidable clinical challenge. Porous titanium alloys (pTi) have been emerging as ideal endosseous implants due to the excellent biocompatibility and structural properties, whereas inadequate osseointegration poses risks for unreliable long-term implant stability. Substantial evidence indicates that pulsed electromagnetic fields (PEMF), as a safe noninvasive method, inhibit osteopenia/osteoporosis experimentally and clinically. We herein investigated the efficiency and potential mechanisms of PEMF on osteogenesis and osseointegration of pTi in vitro and in vivo. We demonstrate that PEMF enhanced cellular attachment and proliferation, and induced well-organized cytoskeleton for in vitro osteoblasts seeded in pTi. PEMF promoted gene expressions in Runx2, OSX, COL-1 and Wnt/β-catenin signaling. PEMF-stimulated group exhibited higher Runx2, Wnt1, Lrp6 and β-catenin protein expressions. In vivo results via μCT and histomorphometry show that 6-week and 12-week PEMF promoted osteogenesis, bone ingrowth and bone formation rate of pTi in rabbit femoral bone defect. PEMF promoted femoral gene expressions of Runx2, BMP2, OCN and Wnt/β-catenin signaling. Together, we demonstrate that PEMF improve osteogenesis and osseointegration of pTi by promoting skeletal anabolic activities through a Wnt/β-catenin signaling-associated mechanism. PEMF might become a promising biophysical modality for enhancing the repair efficiency and quality of pTi in bone defect.

  11. Release of gentamicin from bone regenerative materials: an in vitro study.

    PubMed

    Teller, M; Gopp, U; Neumann, H-G; Kühn, K-D

    2007-04-01

    Antibiotic loading of bone regenerative materials is a promising way to protect augmentation procedures from infection during the resorption phase of bone substitutes. Especially in the early stage of implantation, it should protect the grafted site against microbiological pathogens. The present study reports the release kinetics of gentamicin after loading from two synthetic bone filling materials. The first, BONITmatrix, is a biphasic calcium phosphate silica composite obtained by the sol-gel route consisting of 13% silicon dioxide (w/w) and calcium phosphates (hydroxyapatite/beta-tricalcium phosphate 60/40 w/w). The second, Synthacer, is a sintered hydroxyapatite ceramic. Gentamicin was loaded by dipping and by vacuum coating. Release kinetics of the loaded Gentamicin was investigated by fluorescence polarization immunoassay and by staphylococcus aureus assay. By dipping, loading failed for Synthacer, and it was 12.7 mg gentamicin per gram bone substitute for BONITmatrix. By vacuum coating, loading was 11.3 mg gentamicin per gram bone substitute for Synthacer and 7.4 mg gentamicin per gram bone substitute for BONITmatrix. Distinct release kinetics were measured. For Synthacer, a high initial release was followed by a lower protracted release level up to 28 days. For BONITmatrix release was continuous over the investigated 70-day period. The present data suggest that the porosity properties at the nano- and microscopic levels, or the composition are responsible for antibiotic loading and subsequent release.

  12. Development of the NIST bone ash standard reference material for environmental radioactivity measurement.

    PubMed

    Lin, Z; Inn, K G; Altzitzoglou, T; Arnold, D; Cavadore, D; Ham, G J; Korun, M; Wershofen, H; Takata, Y; Young, A

    1998-01-01

    The bone ash standard reference material (SRM), a blend of 4% contaminated human bone and 96% diluent bovine bone, has been developed for radiochemical method validation and quality control for radio-bone analysis. The massic activities of 90Sr, 226Ra, 230Th, 232Th, 234U, 235U, 238U, 238Pu, (239 + 240)Pu and (243 + 244)Cm were certified using a variety of radiochemical procedures and detection methods. Measurements confirmed undetectable radionuclide heterogeneity down to a sample size of 5 g. thereby implying adequate blending of particulate materials with dilution factors of up to 17,900. The results among most of the intercomparison laboratories and their methods were consistent. Disequilibrium was observed for decay chains: 234U(0.67 mBq/g)-230Th(0.47 mBq/g)-226Ra(15.1 mBq/g)-210Pb(23 mBq/g)-210Po(13 mBq/g) and 232Th(0.99 mBq/g)-228 Ra(6.1 mBq/g)-228Th(7.1 mBq/g). The disequilibria were the results of mixing occupationally contaminated human bone with natural bovine bone and the fractionation during internal biological processes. The massic activity of 210Pb, 228Th and 241Am were not certified because of insufficient 228Ra and 241Pu data and lack of knowledge in how 222Rn and its daughters will be fractionated in the SRM bottle over time.

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

    PubMed Central

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

    2015-01-01

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

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

    SciTech Connect

    Gibbons, M.J.; Butler, D.L.; Grood, E.S.; Bylski-Austrow, D.I.; Levy, M.S.; Noyes, F.R. )

    1991-03-01

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

  15. Histometric analysis of bone repair in bone-implant interface using a polylactic/polyglycolic acid copolymer associated with implants in rabbit tibia.

    PubMed

    Freire, Alexandre Rodrigues; Rossi, Ana Cláudia; Queiroz, Thallita Pereira; Gulinelli, Jéssica Lemos; Souza, Francisley Ávila; Margonar, Rogério; Garcia-Júnior, Idelmo Rangel; Hochuli-Vieira, Eduardo; Okamoto, Roberta

    2012-09-01

    The purpose of this study was to evaluate the association of the combination of polylactic/polyglycolic acid around implants installed with and without primary stability through the histometric analysis of bone-implant interface. We used male rabbits, each of which received 2 titanium implants in each tibial metaphysis. The animals were divided into 4 groups: control with primary stability (CPS), control without primary stability (C), polymer with primary stability (PPS), and polymer without primary stability (P). Euthanasia was performed at postoperative days 40 and 90. The pieces were embedded in resin, sectioned, scraped, and stained with alizarin red and Stevenel blue. Histometric analysis evaluated the linear extension of contact between the bone and implant surface on the implant collar (CIC) and contact between the bone and implant surface on the first thread (CFT). Also evaluated was the area of newly formed bone (ANB) in the first thread. The results showed that there was new bone formation in all groups and during all periods. At 40 days, the ANB was higher in the PPS group than in the P group (P < .001); the CFT was statistically higher in the CPS group than the PPS group (P < .001) and was higher in the CPS group than the C group (P < .001). At 40 and 90 days, the CIC was higher in the P group than in the C group (P < .001). In conclusion, the copolymer had biocompatibility, enhanced bone healing, and presented osteoconductive properties, thus raising the contact between bone and implant, even without primary stability.

  16. Energy-dissipating and self-repairing SMA-ECC composite material system

    NASA Astrophysics Data System (ADS)

    Li, Xiaopeng; Li, Mo; Song, Gangbing

    2015-02-01

    Structural component ductility and energy dissipation capacity are crucial factors for achieving reinforced concrete structures more resistant to dynamic loading such as earthquakes. Furthermore, limiting post-event residual damage and deformation allows for immediate re-operation or minimal repairs. These desirable characteristics for structural ‘resilience’, however, present significant challenges due to the brittle nature of concrete, its deformation incompatibility with ductile steel, and the plastic yielding of steel reinforcement. Here, we developed a new composite material system that integrates the unique ductile feature of engineered cementitious composites (ECC) with superelastic shape memory alloy (SMA). In contrast to steel reinforced concrete (RC) and SMA reinforced concrete (SMA-RC), the SMA-ECC beams studied in this research exhibited extraordinary energy dissipation capacity, minimal residual deformation, and full self-recovery of damage under cyclic flexural loading. We found that the tensile strain capacity of ECC, tailored up to 5.5% in this study, allows it to work compatibly with superelastic SMA. Furthermore, the distributed microcracking damage mechanism in ECC is critical for sufficient and reliable recovery of damage upon unloading. This research demonstrates the potential of SMA-ECC for improving resilience of concrete structures under extreme hazard events.

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

    NASA Astrophysics Data System (ADS)

    Fântânariu, Mircea; Trincă, Lucia Carmen; Solcan, Carmen; Trofin, Alina; Strungaru, Ştefan; Şindilar, Eusebiu Viorel; Plăvan, Gabriel; Stanciu, Sergiu

    2015-10-01

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

  18. Bone remodeling adjacent to total hip replacements: A naturally occurring material design problem

    NASA Astrophysics Data System (ADS)

    Harrigan, Timothy P.; Hamilton, James J.

    1993-10-01

    The reaction of bone to orthopedic implants is an example of a self-adjusting material which changes from a ‘normal state’ to an altered state, based on the mechanical features of the implant and the loads applied to it. The changes in bone around cemented and uncemented femoral total hip components are well documented, and many numerical characterizations of the material reaction to stress have attempted to mimic the natural remodeling process. In this study we review the development of a simple material remodeling rule which yields a stable structure which is optimal and which allows a unique solution. We then use this algorithm to assess the effect of prosthesis stiffness and the presence of a compliant layer on bone remodeling around these implants. An axisymmetric model for axial loading is used to model changes in bone density through the thickness of the cancellous bone around the implants. With cortical remodeling left out of the simulation, the simulations showed density distributions that agreed in general with the results in the literature, and showed a marked difference in response if a compliant layer was added to the prosthesis.

  19. Material heterogeneity in cancellous bone promotes deformation recovery after mechanical failure

    PubMed Central

    Torres, Ashley M.; Matheny, Jonathan B.; Keaveny, Tony M.; Taylor, David; Rimnac, Clare M.; Hernandez, Christopher J.

    2016-01-01

    Many natural structures use a foam core and solid outer shell to achieve high strength and stiffness with relatively small amounts of mass. Biological foams, however, must also resist crack growth. The process of crack propagation within the struts of a foam is not well understood and is complicated by the foam microstructure. We demonstrate that in cancellous bone, the foam-like component of whole bones, damage propagation during cyclic loading is dictated not by local tissue stresses but by heterogeneity of material properties associated with increased ductility of strut surfaces. The increase in surface ductility is unexpected because it is the opposite pattern generated by surface treatments to increase fatigue life in man-made materials, which often result in reduced surface ductility. We show that the more ductile surfaces of cancellous bone are a result of reduced accumulation of advanced glycation end products compared with the strut interior. Damage is therefore likely to accumulate in strut centers making cancellous bone more tolerant of stress concentrations at strut surfaces. Hence, the structure is able to recover more deformation after failure and return to a closer approximation of its original shape. Increased recovery of deformation is a passive mechanism seen in biology for setting a broken bone that allows for a better approximation of initial shape during healing processes and is likely the most important mechanical function. Our findings suggest a previously unidentified biomimetic design strategy in which tissue level material heterogeneity in foams can be used to improve deformation recovery after failure. PMID:26929343

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

    PubMed

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

    2013-04-01

    This work is part of an ongoing program to develop a new carbon fiber/flax/epoxy (CF/flax/epoxy) hybrid composite material for use as an orthopaedic long bone fracture plate, instead of a metal plate. The purpose of this study was to evaluate the mechanical properties of this new novel composite material. The composite material had a "sandwich structure", in which two thin sheets of CF/epoxy were attached to each outer surface of the flax/epoxy core, which resulted in a unique structure compared to other composite plates for bone plate applications. Mechanical properties were determined using tension, three-point bending, and Rockwell hardness tests. Also, scanning electron microscopy (SEM) was used to characterize the failure mechanism of specimens in tension and three-point bending tests. The results of mechanical tests revealed a considerably high ultimate strength in both tension (399.8MPa) and flexural loading (510.6MPa), with a higher elastic modulus in bending tests (57.4GPa) compared to tension tests (41.7GPa). The composite material experienced brittle catastrophic failure in both tension and bending tests. The SEM images, consistent with brittle failure, showed mostly fiber breakage and fiber pull-out at the fractured surfaces with perfect bonding at carbon fibers and flax plies. Compared to clinically-used orthopaedic metal plates, current CF/flax/epoxy results were closer to human cortical bone, making the material a potential candidate for use in long bone fracture fixation. PMID:23499250

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

    PubMed

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

    2013-04-01

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

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

    PubMed

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

    2012-03-01

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

  3. A new heterologous fibrin sealant as scaffold to recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins for the repair of tibial bone defects.

    PubMed

    Machado, Eduardo Gomes; Issa, João Paulo Mardegan; Figueiredo, Fellipe Augusto Tocchini de; Santos, Geovane Ribeiro Dos; Galdeano, Ewerton Alexandre; Alves, Mariana Carla; Chacon, Erivelto Luis; Ferreira Junior, Rui Seabra; Barraviera, Benedito; Cunha, Marcelo Rodrigues da

    2015-04-01

    Tissue engineering has special interest in bone tissue aiming at future medical applications Studies have focused on recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins due to the osteogenic properties of rhBMP-2 and the angiogenic characteristic of fraction 1 protein (P-1) extracted from the rubber tree Hevea brasiliensis. Furthermore, heterologous fibrin sealant (FS) has been shown as a promising alternative in regenerative therapies. The aim of this study was to evaluate these substances for the repair of bone defects in rats. A bone defect measuring 3mm in diameter was created in the proximal metaphysis of the left tibia of 60 rats and was implanted with rhBMP-2 or P-1 in combination with a new heterologous FS derived from snake venom. The animals were divided into six groups: control (unfilled bone defect), rhBMP-2 (defect filled with 5μg rhBMP-2), P-1 (defect filled with 5μg P-1), FS (defect filled with 8μg FS), FS/rhBMP-2 (defect filled with 8μg FS and 5μg rhBMP-2), FS/P-1 (defect filled with 8μg FS and 5μg P-1). The animals were sacrificed 2 and 6 weeks after surgery. The newly formed bone projected from the margins of the original bone and exhibited trabecular morphology and a disorganized arrangement of osteocyte lacunae. Immunohistochemical analysis showed intense expression of osteocalcin in all groups. Histometric analysis revealed a significant difference in all groups after 2 weeks (p<0.05), except for the rhBMP-2 and FS/rhBMP-2 groups (p>0.05). A statistically significant difference (p<0.05) was observed in all groups after 6 weeks in relation to the volume of newly formed bone in the surgical area. In conclusion, the new heterologous fibrin sealant was found to be biocompatible and the combination with rhBMP-2 showed the highest osteogenic and osteoconductive capacity for bone healing. These findings suggest a promising application of this combination in the regeneration surgery. PMID:25825118

  4. Treatment of intraosseous ganglia and bone cysts of the carpal bones with injectable calcium phosphate bone cement.

    PubMed

    Yajima, Hiroshi; Murata, Keiichi; Kawamura, Kenji; Kawate, Kenji; Takakura, Yoshinori

    2008-01-01

    This article documents the outcome of treatment of intraosseous ganglia and simple bone cysts of the carpal bones by curettage and injectable calcium phosphate bone cement (CPC) grafting. The patients consisted of five men and three women. One had a cystic lesion in the scaphoid, one in the hamate, and five in the lunate. Curettage of the lesions was performed, and CPC was injected into the cavity. Five patients were diagnosed with a ganglion and three with a simple bone cyst. Among the five patients with wrist pain, the pain disappeared completely in four. Radiographs showed apparent partial absorption of CPC in four patients and no absorption in other four. There were no recurrence of tumours and no other complications were encountered. We conclude that calcium phosphate bone cement is a useful material for repairing bone defect after curettage of an intraosseous ganglion or bone cyst of a carpal bone.

  5. Bone Regeneration of Rat Tibial Defect by Zinc-Tricalcium Phosphate (Zn-TCP) Synthesized from Porous Foraminifera Carbonate Macrospheres

    PubMed Central

    Chou, Joshua; Hao, Jia; Kuroda, Shinji; Bishop, David; Ben-Nissan, Besim; Milthorpe, Bruce; Otsuka, Makoto

    2013-01-01

    Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP) as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair. PMID:24351911

  6. Reactions and Surface Transformations of a Bone-Bioactive Material in a Simulated Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Radin, S.; Ducheyne, P.; Ayyaswamy, P. S.

    1999-01-01

    A comprehensive program to investigate the expeditious in vitro formation of three-dimensional bone-like tissue is currently underway at the University of Pennsylvania. The study reported here forms a part of that program. Three-dimensional bone-like tissue structures may be grown under the simulated microgravity conditions of NASA designed Rotating Wall Bioreactor Vessels (RWV's). Such tissue growth will have wide clinical applications. In addition, an understanding of the fundamental changes that occur to bone cells under simulated microgravity would yield important information that will help in preventing or minimizing astronaut bone loss, a major health issue with travel or stay in space over long periods of time. The growth of three-dimensional bone-like tissue structures in RWV's is facilitated by the use of microcarriers which provide structural support. If the microcarrier material additionally promotes bone cell growth, then it is particularly advantageous to employ such microcarriers. We have found that reactive, bone-bioactive glass (BBG) is an attractive candidate for use as microcarrier material. Specifically, it has been found that BBG containing Ca- and P- oxides upregulates osteoprogenitor cells to osteoblasts. This effect on cells is preceded by BBG reactions in solution which result in the formation of a Ca-P surface layer. This surface further transforms to a bone-like mineral (i.e., carbonated crystalline hydroxyapatite (c-HA)). At normal gravity, time-dependent, immersion-induced BBG reactions and transformations are greatly affected both by variations in the composition of the milieu in which the glass is immersed and on the immersion conditions. However, the nature of BBG reactions and phase transformations under the simulated microgravity conditions of RWV's are unknown, and must be understood in order to successfully use BBG as microcarrier material in RWV'S. In this paper, we report some of our recent findings in this regard using

  7. Tensile material properties of human tibia cortical bone effects of orientation and loading rate.

    PubMed

    Kemper, Andrew R; McNally, Craig; Manoogian, Sarah J; Duma, Stefan M

    2008-01-01

    The purpose of this study was to quantify effects of both specimen orientation and loading rate on the tensile material properties for human tibia cortical bone in a controlled study. This study presents 25 human tibia cortical bone coupon tests obtained from the mid-diaphysis of two fresh frozen male human cadavers: 11 axial and 14 lateral. The primary component for the tension coupon testing was a high rate servo-hydraulic Material Testing System (MTS) with a custom slack adaptor. The specimen were loaded at a constant strain rate of approximately 0.05 strains/s, 0.5 strains/s, or 5.0 strains/s. Axial specimens were found to have a significantly larger ultimate stress and ultimate strain compared to lateral specimens for all loading rates, and a significantly larger modulus for low and high loading rates. This finding illustrates the anisentropic behavior of bone over a range of strain rates, which is attributed to the microstructure of the bone and the osteon orientation along the long axis of the bone. With respect to loading rate, both axial and lateral specimens showed significant increases in the modulus and significant decreases in ultimate strain with increased loading rate. Although not significant, axial specimens showed another traditional viscoelastic trend, with ultimate stress increasing with increased loading rate. PMID:19141952

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  9. Repair of a segmental long bone defect in human by implantation of a novel multiple disc graft.

    PubMed

    Hesse, Eric; Kluge, Gerald; Atfi, Azeddine; Correa, Diego; Haasper, Carl; Berding, Georg; Shin, Hoen-oh; Viering, Jörg; Länger, Florian; Vogt, Peter M; Krettek, Christian; Jagodzinski, Michael

    2010-05-01

    Large segmental defects of the weight bearing long bones are very difficult to reconstruct. Current treatment options are afflicted with several limitations and disadvantages. We describe a novel approach to regenerate a segmental long bone defect in a patient using a multiple disc graft. Decellularized bovine trabecular bone discs were seeded with autologous bone marrow cells and cultured in a perfusion chamber for three weeks. Multiple cell-seeded discs were implanted to close a 72 mm defect of the distal tibia in a 58-year-old woman, and fixed by an intramedullary nail. Bone formation was assessed non-invasively by plain radiographs and 18F-labeled sodium fluoride-based co-registration of positron emission- and computed tomography (PET/CT). Bone was actively formed around the grafted defect as early as six weeks after surgery. Because the tibia was sufficiently stabilized, the patient was able to freely walk with full weight bearing 6 weeks after surgery. The uneventful two-year follow-up and the satisfaction of the patient demonstrated the success of the procedure. Therefore the use of multiple cell-seeded disc grafts can be considered as a treatment alternative for patients with segmental long bone defects. PMID:20153850

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

    PubMed Central

    Gedrange, Tomasz

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

    Gedrange, Tomasz

    2016-01-01

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

  14. Nano-modified cement composites and its applicability as concrete repair material

    NASA Astrophysics Data System (ADS)

    Manzur, Tanvir

    optimum mix proportion to produce CNT reinforced cement composites. In this study, an extensive parametric study has been conducted using different types of treated and untreated multi walled nanotubes (MWNT) as reinforcement of cementitious composites having different mix proportions. It is found that mixing of nanotubes within cement matrix is the key to develop composites having desirable properties. A mixing technique has been proposed to address the issues related to dispersion of nanotubes within cement matrix. Polycarboxylate based super plasticizer has been proposed to use as surfactant. It is evident that there exists an optimum concentration of MWNT and mix proportion to achieve proper reinforcement behavior and strength properties. The affect of size of MWNT on strengths (both compressive and flexure) of composites has also been investigated. Based on the parametric study and statistical analysis, a tentative optimum mix proportion has been proposed. Composites made by the proposed mixing technique and design mix obtained 26, 27 and 16% higher compressive strength as compared to control samples at the age of 3, 7 and 28 day, respectively. Flexural strengths of those composites at 3, 7 and 28 day were about 24, 24.5 and 20% higher than that of control samples, respectively. It has also been suggested that application of MWNT reinforced cement mortar as concrete repair material has excellent potential since composites exhibited desirable behavior in setting time, bleeding and slant shear.

  15. Rapid maxillary expansion in alveolar cleft repaired with a tissue-engineered bone in a canine model.

    PubMed

    Huang, Jialiang; Tian, Bo; Chu, Fengting; Yang, Chenjie; Zhao, Jun; Jiang, Xinquan; Qian, Yufen

    2015-08-01

    This study aims to investigate the effects of orthodontic expansion on graft area of a tissue-engineered bone (TEB) BMSCs/β-TCP, and to find an alternative strategy for the therapy of alveolar cleft. A unilateral alveolar cleft canine model was established and then treated with BMSCs/β-TCP under rapid maxillary expansion (RME). Sequential fluorescent labeling, radiography and helical computed tomography were used to evaluate new bone formation and mineralization in the graft area. Hematoxylin-eosin staining and Van Gieson׳s picro fuchsin staining were performed for histological and histomorphometric observation. ALP activity, mineralization and the expression of osteogenic differentiation related genes of BMSCs that grew on the β-TCP scaffold were promoted by their cultivation in osteogenic medium. Based on fact, TEB was constructed. After 8 weeks of treatment with BMSCs/β-TCP followed by RME, new bone formation and mineralization of the dogs were markedly accelerated, and bone resorption was significantly reduced, compared with the untreated dogs, or those only treated with autogenous iliac bone. The treatment with both TEB and RME evidently made the bone trabecula more abundant and the area of bone formation larger. What is more, there were no significant differences between BMSCs/β-TCP group and the group treated with autogenous bone and RME. This study further revealed that TEB was not only a feasible clinical approach for patients with alveolar cleft, but also a potential substituent of autogenous bone, and its combination with RME might be an alternative strategy for the therapy of alveolar cleft.

  16. Biomaterials for Bone Regenerative Engineering.

    PubMed

    Yu, Xiaohua; Tang, Xiaoyan; Gohil, Shalini V; Laurencin, Cato T

    2015-06-24

    Strategies for bone tissue regeneration have been continuously evolving for the last 25 years since the introduction of the "tissue engineering" concept. The convergence of the life, physical, and engineering sciences has brought in several advanced technologies available to tissue engineers and scientists. This resulted in the creation of a new multidisciplinary field termed as "regenerative engineering". In this article, the role of biomaterials in bone regenerative engineering is systematically reviewed to elucidate the new design criteria for the next generation of biomaterials for bone regenerative engineering. The exemplary design of biomaterials harnessing various materials characteristics towards successful bone defect repair and regeneration is highlighted. Particular attention is given to the attempts of incorporating advanced materials science, stem cell technologies, and developmental biology into biomaterials design to engineer and develop the next generation bone grafts.

  17. Gelatin-apatite bone mimetic co-precipitates incorporated within biopolymer matrix to improve mechanical and biological properties useful for hard tissue repair

    PubMed Central

    Won, Jong-Eun; El-Fiqi, Ahmed; Jegal, Seung-Hwan; Han, Cheol-Min; Lee, Eun-Jung; Knowles, Jonathan C

    2014-01-01

    Synthetic biopolymers are commonly used for the repair and regeneration of damaged tissues. Specifically targeting bone, the composite approach of utilizing inorganic components is considered promising in terms of improving mechanical and biological properties. We developed gelatin-apatite co-precipitates which mimic the native bone matrix composition within poly(lactide-co-caprolactone) (PLCL). Ionic reaction of calcium and phosphate with gelatin molecules enabled the co-precipitate formation of gelatin-apatite nanocrystals at varying ratios. The gelatin-apatite precipitates formed were carbonated apatite in nature, and were homogeneously distributed within the gelatin matrix. The incorporation of gelatin-apatite significantly improved the mechanical properties, including tensile strength, elastic modulus and elongation at break, and the improvement was more pronounced as the apatite content increased. Of note, the tensile strength increased to as high as 45 MPa (a four-fold increase vs. PLCL), the elastic modulus was increased up to 1500 MPa (a five-fold increase vs. PLCL), and the elongation rate was ∼240% (twice vs. PLCL). These results support the strengthening role of the gelatin-apatite precipitates within PLCL. The gelatin-apatite addition considerably enhanced the water affinity and the acellular mineral-forming ability in vitro in simulated body fluid; moreover, it stimulated cell proliferation and osteogenic differentiation. Taken together, the GAp-PLCL nanocomposite composition is considered to have excellent mechanical and biological properties, which hold great potential for use as bone regenerative matrices. PMID:23985536

  18. A MATERIAL COST-MINIMIZATION ANALYSIS FOR HERNIA REPAIRS AND MINOR PROCEDURES DURING A SURGICAL MISSION IN THE DOMINICAN REPUBLIC

    PubMed Central

    Cavallo, Jaime A.; Ousley, Jenny; Barrett, Christopher D.; Baalman, Sara; Ward, Kyle; Borchardt, Malgorzata; Thomas, J. Ross; Perotti, Gary; Frisella, Margaret M.; Matthews, Brent D.

    2013-01-01

    INTRODUCTION Expenditures on material supplies and medications constitute the greatest per capita costs for surgical missions. We hypothesized that supply acquisition at nonprofit organization (NPO) costs would lead to significant cost-savings compared to supply acquisition at US academic institution costs from the provider perspective for hernia repairs and minor procedures during a surgical mission in the Dominican Republic (DR). METHODS Items acquired for a surgical mission were uniquely QR-coded for accurate consumption accounting. Both NPO and US academic institution unit costs were associated with each item in an electronic inventory system. Medication doses were recorded and QR-codes for consumed items were scanned into a record for each sampled procedure. Mean material costs and cost savings ± SDs were calculated in US dollars for each procedure type. Cost-minimization analyses between the NPO and the US academic institution platforms for each procedure type ensued using a two-tailed Wilcoxon matched-pairs test with α=0.05. Item utilization analyses generated lists of most frequently used materials by procedure type. RESULTS The mean cost savings of supply acquisition at NPO costs for each procedure type were as follows: $482.86 ± $683.79 for unilateral inguinal hernia repair (IHR, n=13); $332.46 ± $184.09 for bilateral inguinal hernia repair (BIHR, n=3); $127.26 ± $13.18 for hydrocelectomy (HC, n=9); $232.92 ± $56.49 for femoral hernia repair (FHR, n=3); $120.90 ± $30.51 for umbilical hernia repair (UHR, n=8); $36.59 ± $17.76 for minor procedures (MP, n=26); and $120.66 ± $14.61 for pediatric inguinal hernia repair (PIHR, n=7). CONCLUSION Supply acquisition at NPO costs leads to significant cost-savings compared to supply acquisition at US academic institution costs from the provider perspective for IHR, HC, UHR, MP, and PIHR during a surgical mission to DR. Item utilization analysis can generate minimum-necessary material lists for each procedure

  19. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    PubMed Central

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100–150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1–10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications. PMID:26782020

  20. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects.

    PubMed

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  1. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    NASA Astrophysics Data System (ADS)

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

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

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Gun; Bark, Chung Wung

    2014-11-01

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

  3. Assessment of the effects of laser photobiomodulation on peri-implant bone repair through energy dispersive x-ray fluorescence: A study of dogs

    NASA Astrophysics Data System (ADS)

    Menezes, R. F.; Araújo, N. C.; Carneiro, V. S. M.; Moreno, L. M.; Guerra, L. A. P.; Santos Neto, A. P.; Gerbi, M. E. M.

    2016-03-01

    Bone neoformation is essential in the osteointegration of implants and has been correlated with the repair capacity of tissues, the blood supply and the function of the cells involved. Laser therapy accelerates the mechanical imbrication of peri-implant tissue by increasing osteoblastic activity and inducing ATP, osteopontin and the expression of sialoproteins. Objective: The aim of the present study was to assess peri-implant bone repair using the tibia of dogs that received dental implants and laser irradiation (AsGaAl 830nm - 40mW, CW, f~0.3mm) through Energy Dispersive X-ray Fluorescence (EDXRF). Methodology: Two groups were established: G1 (Control, n=20; two dental implants were made in the tibia of each animal; 10 animals); G2 (Experimental, n=20, two dental implants were made in the tibia each animal + Laser therapy; 10 animals). G2 was irradiated every 48 hours for two weeks, with a total of seven sessions. The first irradiation was conducted during the surgery, at which time a point in the surgical alveolus was irradiated prior to the placement of the implant and four new spatial positions were created to the North, South, East and West (NSEW) of the implant. The subsequent sessions involved irradiation at these four points and at one infra-implant point (in the direction of the implant apex). Each point received 4J/cm2 and a total dose of 20J/cm2 per session (treatment dose=140J/cm2). The specimens were removed 15 and 30 days after the operation for the EDXRF test. The Mann- Whitney statistical test was used to assess the results. Results: The increase in the calcium concentration in the periimplant region of the irradiated specimens (G2) was statistically significant (p < 0.05), when compared with the control group (G1). Conclusion: The results of the present study show that irradiation with the AsGaAl laser promoted an acceleration in bone repair in the peri-implant region.

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

    PubMed

    Wydra, A; Maev, R Gr

    2013-11-21

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

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

    NASA Astrophysics Data System (ADS)

    Wydra, A.; Maev, R. Gr

    2013-11-01

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

  6. Freeze-Dried Rat Bone Marrow Mesenchymal Stem Cell Paracrine Factors: A Simplified Novel Material for Skin Wound Therapy

    PubMed Central

    Peng, Yan; Xuan, Min; Zou, Jiping; Liu, Hongwei; Zhuo, Ziyuan; Wan, Yu

    2015-01-01

    The mesenchymal stem cell (MSC) supernatant is well known as a rich source of autologous cytokines and universally used for tissue regeneration in current clinical medicine. However, the limitation of conditioned medium used in open-wound repair compels the need to find a more sophisticated way to take advantage of the trophic factors of MSCs. We have now fabricated a three-dimensional membrane from freeze-dried bone marrow mesenchymal stem cells-conditioned medium (FBMSC-CM) using a simple freeze-dried protocol. Scanning electron microscopy images showed the microstructure of the FBMSC-CM membrane (FBMSC-CMM) resembling a mesh containing growth factors. ELISA was used to test the paracrine factors retained in the FBMSC-CMM, and the results indicated that FBMSC-CMM withheld over 80% of the paracrine factors. Live/dead assays were adopted to test the toxicity of the FBMSC-CMM on cultured rat dermal fibroblasts, and the results confirmed its biological safety with low toxicity. Moreover, the FBMSC-CMM could significantly accelerate wound healing and enhance the neovascularization as well as epithelialization through strengthening the trophic factors in the wound bed as determined by immunohistochemical staining. Thus, the ability to maintain paracrine factors and enhance the effectiveness of these growth factors in the wound as well as the simple procedure and economical materials required for production qualifies the FBMSC-CMM to be a candidate biomaterial for open-wound regeneration. PMID:25343727

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

    PubMed Central

    Sánchez-Torres, Alba; Sánchez-Garcés, Maria Á

    2014-01-01

    Objectives: Analyse the effectiveness of different materials and techniques used in guided tissue regeneration (GTR) applied in periapical surgery, comparing the success rate obtained in 4-wall defects and in through-and-through bone lesions as well as to establish prognostic factors. Material and Methods: A Cochrane, PubMed-MEDLINE and Scopus database search (October 2012 to March 2013) was conducted with the search terms “periapical surgery”, “surgical endodontic treatment”, “guided tissue regeneration”, “bone regeneration”, “bone grafts”, “barrier membranes” and “periapical lesions” individually and next, using the Boolean operator “AND”. The inclusion criteria were the use of GTR (bone graft and/or membrane barrier), clinical studies including at least 10 patients, 10 years aged articles published in English or French. The exclusion criteria were case reports and nonhuman studies. Results: 34 publications were selected from a total of 483. 9 of the 34 were excluded. Finally, the systematic review included 25 articles: 2 metaanalysis, 8 reviews, 13 prospective studies and 2 retrospective studies. They were stratified according to their level of scientific evidence using the SORT criteria. The 4-wall periapical