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Sample records for bone tissues

  1. Distribution Principle of Bone Tissue

    CERN Document Server

    Fan, Yifang; Fan, Yubo; Xu, Zongxiang; Li, Zhiyu

    2009-01-01

    Using the analytic and experimental techniques we present an exploratory study of the mass distribution features of the high coincidence of centre of mass of heterogeneous bone tissue in vivo and its centroid of geometry position. A geometric concept of the average distribution radius of bone issue is proposed and functional relation of this geometric distribution feature between the partition density and its relative tissue average distribution radius is observed. Based upon the mass distribution feature, our results suggest a relative distance assessment index between the center of mass of cortical bone and the bone center of mass and establish a bone strength equation. Analysing the data of human foot in vivo, we notice that the mass and geometric distribution laws have expanded the connotation of Wolff's law, which implies a leap towards the quantitative description of bone strength. We finally conclude that this will not only make a positive contribution to help assess osteoporosis, but will also provide...

  2. Prevascularized bone tissue engineering

    NARCIS (Netherlands)

    Rouwkema, Jeroen

    2007-01-01

    Tissue engineering has been an active field of research for several decades now. However, the number of successful clinical applications in the field of tissue engineering are limited and can mainly be found in thin or avascular tissues like skin and cartilage. One of the current limitations of tiss

  3. Collagen for bone tissue regeneration.

    Science.gov (United States)

    Ferreira, Ana Marina; Gentile, Piergiorgio; Chiono, Valeria; Ciardelli, Gianluca

    2012-09-01

    In the last decades, increased knowledge about the organization, structure and properties of collagen (particularly concerning interactions between cells and collagen-based materials) has inspired scientists and engineers to design innovative collagen-based biomaterials and to develop novel tissue-engineering products. The design of resorbable collagen-based medical implants requires understanding the tissue/organ anatomy and biological function as well as the role of collagen's physicochemical properties and structure in tissue/organ regeneration. Bone is a complex tissue that plays a critical role in diverse metabolic processes mediated by calcium delivery as well as in hematopoiesis whilst maintaining skeleton strength. A wide variety of collagen-based scaffolds have been proposed for different tissue engineering applications. These scaffolds are designed to promote a biological response, such as cell interaction, and to work as artificial biomimetic extracellular matrices that guide tissue regeneration. This paper critically reviews the current understanding of the complex hierarchical structure and properties of native collagen molecules, and describes the scientific challenge of manufacturing collagen-based materials with suitable properties and shapes for specific biomedical applications, with special emphasis on bone tissue engineering. The analysis of the state of the art in the field reveals the presence of innovative techniques for scaffold and material manufacturing that are currently opening the way to the preparation of biomimetic substrates that modulate cell interaction for improved substitution, restoration, retention or enhancement of bone tissue function.

  4. Stem cells in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Jeong Min [Department of Preventive and Social Dentistry and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kim, Byung-Chul; Park, Jae-Hong; Kwon, Il Keun; Hwang, Yu-Shik [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Mantalaris, Anathathios, E-mail: yshwang@khu.ac.k [Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2010-12-15

    Bone tissue engineering has been one of the most promising areas of research, providing a potential clinical application to cure bone defects. Recently, various stem cells including embryonic stem cells (ESCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), adipose tissue-derived stem cells (ADSCs), muscle-derived stem cells (MDSCs) and dental pulp stem cells (DPSCs) have received extensive attention in the field of bone tissue engineering due to their distinct biological capability to differentiate into osteogenic lineages. The application of these stem cells to bone tissue engineering requires inducing in vitro differentiation of these cells into bone forming cells, osteoblasts. For this purpose, efficient in vitro differentiation towards osteogenic lineage requires the development of well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source for application to bone tissue engineering therapies. This review provides a critical examination of the various experimental strategies that could be used to direct the differentiation of ESC, BM-MSC, UCB-MSC, ADSC, MDSC and DPSC towards osteogenic lineages and their potential applications in tissue engineering, particularly in the regeneration of bone. (topical review)

  5. Towards improved scaffolds for bone tissue engineering

    NARCIS (Netherlands)

    Nandakumar, A.

    2012-01-01

    Tissue engineering aims to restore, maintain or improve tissue function of damaged tissues. In a classical set-up, a scaffold functions as a supporting structure and a carrier for growth factors and/or cells. Human mesenchymal stromal cells (hMSCs) have the ability to differentiate into bone, cartil

  6. The materials used in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-17

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

  7. Bone tissue engineering: from bench to bedside

    Directory of Open Access Journals (Sweden)

    Maria A. Woodruff

    2012-10-01

    Full Text Available The drive to develop bone grafts for the filling of major gaps in the skeletal structure has led to a major research thrust towards developing biomaterials for bone engineering. Unfortunately, from a clinical perspective, the promise of bone tissue engineering which was so vibrant a decade ago has so far failed to deliver the anticipated results of becoming a routine therapeutic application in reconstructive surgery. Here we describe our bench to bedside concept, the first clinical results and a detailed analysis of long-term bone regeneration studies in preclinical animal models, exploiting methods of micro- and nano analysis of biodegradable composite scaffolds.

  8. Orthopaedic tissue engineering and bone regeneration.

    Science.gov (United States)

    Dickson, Glenn; Buchanan, Fraser; Marsh, David; Harkin-Jones, Eileen; Little, Uel; McCaigue, Mervyn

    2007-01-01

    Orthopaedic tissue engineering combines the application of scaffold materials, cells and the release of growth factors. It has been described as the science of persuading the body to reconstitute or repair tissues that have failed to regenerate or heal spontaneously. In the case of bone regeneration 3-D scaffolds are used as a framework to guide tissue regeneration. Mesenchymal cells obtained from the patient via biopsy are grown on biomaterials in vitro and then implanted at a desired site in the patient's body. Medical implants that encourage natural tissue regeneration are generally considered more desirable than metallic implants that may need to be removed by subsequent intervention. Numerous polymeric materials, from natural and artificial sources, are under investigation as substitutes for skeletal elements such as cartilage and bone. For bone regeneration, cells (obtained mainly from bone marrow aspirate or as primary cell outgrowths from bone biopsies) can be combined with biodegradable polymeric materials and/or ceramics and absorbed growth factors so that osteoinduction is facilitated together with osteoconduction; through the creation of bioactive rather than bioinert scaffold constructs. Relatively rapid biodegradation enables advantageous filling with natural tissue while loss of polymer strength before mass is disadvantageous. Innovative solutions are required to address this and other issues such as the biocompatibility of material surfaces and the use of appropriate scaffold topography and porosity to influence bone cell gene expression.

  9. Nanostructured Biomaterials for Tissue Engineered Bone Tissue Reconstruction

    Directory of Open Access Journals (Sweden)

    Bressan Eriberto

    2012-01-01

    Full Text Available Bone tissue engineering strategies are emerging as attractive alternatives to autografts and allografts in bone tissue reconstruction, in particular thanks to their association with nanotechnologies. Nanostructured biomaterials, indeed, mimic the extracellular matrix (ECM of the natural bone, creating an artificial microenvironment that promotes cell adhesion, proliferation and differentiation. At the same time, the possibility to easily isolate mesenchymal stem cells (MSCs from different adult tissues together with their multi-lineage differentiation potential makes them an interesting tool in the field of bone tissue engineering. This review gives an overview of the most promising nanostructured biomaterials, used alone or in combination with MSCs, which could in future be employed as bone substitutes. Recent works indicate that composite scaffolds made of ceramics/metals or ceramics/polymers are undoubtedly more effective than the single counterparts in terms of osteoconductivity, osteogenicity and osteoinductivity. A better understanding of the interactions between MSCs and nanostructured biomaterials will surely contribute to the progress of bone tissue engineering.

  10. Microgravity Stress: Bone and Connective Tissue.

    Science.gov (United States)

    Bloomfield, Susan A; Martinez, Daniel A; Boudreaux, Ramon D; Mantri, Anita V

    2016-03-15

    The major alterations in bone and the dense connective tissues in humans and animals exposed to microgravity illustrate the dependency of these tissues' function on normal gravitational loading. Whether these alterations depend solely on the reduced mechanical loading of zero g or are compounded by fluid shifts, altered tissue blood flow, radiation exposure, and altered nutritional status is not yet well defined. Changes in the dense connective tissues and intervertebral disks are generally smaller in magnitude but occur more rapidly than those in mineralized bone with transitions to 0 g and during recovery once back to the loading provided by 1 g conditions. However, joint injuries are projected to occur much more often than the more catastrophic bone fracture during exploration class missions, so protecting the integrity of both tissues is important. This review focuses on the research performed over the last 20 years in humans and animals exposed to actual spaceflight, as well as on knowledge gained from pertinent ground-based models such as bed rest in humans and hindlimb unloading in rodents. Significant progress has been made in our understanding of the mechanisms for alterations in bone and connective tissues with exposure to microgravity, but intriguing questions remain to be solved, particularly with reference to biomedical risks associated with prolonged exploration missions.

  11. Bone tissue engineering using 3D printing

    Directory of Open Access Journals (Sweden)

    Susmita Bose

    2013-12-01

    Full Text Available With the advent of additive manufacturing technologies in the mid 1980s, many applications benefited from the faster processing of products without the need for specific tooling or dies. However, the application of such techniques in the area of biomedical devices has been slow due to the stringent performance criteria and concerns related to reproducibility and part quality, when new technologies are in their infancy. However, the use of additive manufacturing technologies in bone tissue engineering has been growing in recent years. Among the different technology options, three dimensional printing (3DP is becoming popular due to the ability to directly print porous scaffolds with designed shape, controlled chemistry and interconnected porosity. Some of these inorganic scaffolds are biodegradable and have proven ideal for bone tissue engineering, sometimes even with site specific growth factor/drug delivery abilities. This review article focuses on recent advances in 3D printed bone tissue engineering scaffolds along with current challenges and future directions.

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

    Science.gov (United States)

    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.].

  13. Composite Scaffolds for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Min Wang

    2006-01-01

    Full Text Available Biomaterial and scaffold development underpins the advancement of tissue engineering. Traditional scaffolds based on biodegradable polymers such as poly(lactic acid and poly(lactic acid-co-glycolic acid are weak and non-osteoconductive. For bone tissue engineering, polymer-based composite scaffolds containing bioceramics such as hydroxyapatite can be produced and used. The bioceramics can be either incorporated in the scaffolds as a dispersed secondary phase or form a thin coating on the pore surface of polymer scaffolds. This bioceramic phase renders the scaffolds bioactive and also strengthens the scaffolds. There are a number of methods that can be used to produce bioceramic-polymer composite scaffolds. This paper gives an overview of our efforts in developing composite scaffolds for bone tissue engineering.

  14. Bioresorbable and nonresorbable polymers for bone tissue engineering.

    Science.gov (United States)

    Girones Molera, Jordi; Mendez, José Alberto; San Roman, Julio

    2012-01-01

    In recent years, bone tissue engineering has emerged as one of the main research areas in the field of regenerative biomedicine. Frequency and relevance age-related diseases, such as healing and regeneration of bone tissues, are rising due to increasing life expectancy. Even though bone tissue has excellent self-regeneration ability, when bone defects exceed a critical size, impaired bone formation can occur and surgical intervention becomes mandatory. Bone tissue engineering represents an alternative approach to conventional bone transplants. The main aim of tissue engineering is to repair, regenerate or reconstruct damaged or degenerative tissue. This review presents an overview on the main materials, techniques and strategies in the field of bone tissue engineering. Whilst presenting some reviews recently published that deepen on each of the sections of the paper, this review article aims to present some of the most relevant advances, both in terms of new materials and strategies, currently being developed for bone repair and regeneration.

  15. Interactions between remodelling, architecture and tissue properties in cancellous bone

    OpenAIRE

    Linden, Jacqueline

    2003-01-01

    textabstractThe aim of the research projects described in this thesis was to gain more insight in the regulation of bone remodeling and in the interactions between bone remodeling, architecture and bone tissue properties. The most striking changes during aging and osteoporosis take place in cancellous bone. For this reason, the research presented in this thesis focussed on bone remodeling in cancellous bone. We used computer modeling, finite element calculations and in vivo labeled bone speci...

  16. Alginate based scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Valente, J.F.A.; Valente, T.A.M. [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Faculdade de Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal); Alves, P.; Ferreira, P. [CIEPQPF, Departamento de Engenharia Quimica, Universidade de Coimbra, Polo II, Pinhal de Marrocos, 3030-290 Coimbra (Portugal); Silva, A. [Centro de Ciencia e Tecnologia Aeroespaciais, Universidade da Beira Interior, Covilha (Portugal); Correia, I.J., E-mail: icorreia@ubi.pt [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Faculdade de Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal)

    2012-12-01

    The design and production of scaffolds for bone tissue regeneration is yet unable to completely reproduce the native bone properties. In the present study new alginate microparticle and microfiber aggregated scaffolds were produced to be applied in this area of regenerative medicine. The scaffolds' mechanical properties were characterized by thermo mechanical assays. Their morphological characteristics were evaluated by isothermal nitrogen adsorption and scanning electron microscopy. The density of both types of scaffolds was determined by helium pycnometry and mercury intrusion porosimetry. Furthermore, scaffolds' cytotoxic profiles were evaluated in vitro by seeding human osteoblast cells in their presence. The results obtained showed that scaffolds have good mechanical and morphological properties compatible with their application as bone substitutes. Moreover, scaffold's biocompatibility was confirmed by the observation of cell adhesion and proliferation after 5 days of being seeded in their presence and by non-radioactive assays. - Highlights: Black-Right-Pointing-Pointer Design and production of scaffolds for bone tissue regeneration. Black-Right-Pointing-Pointer Microparticle and microfiber alginate scaffolds were produced through a particle aggregation technique; Black-Right-Pointing-Pointer Scaffolds' mechanically and biologically properties were characterized through in vitro studies;.

  17. Nanostructured Mesoporous Silicas for Bone Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Isabel Izquierdo-Barba

    2008-01-01

    Full Text Available The research on the development of new biomaterials that promote bone tissue regeneration is receiving great interest by the biomedical scientific community. Recent advances in nanotechnology have allowed the design of materials with nanostructure similar to that of natural bone. These materials can promote new bone formation by inducing the formation of nanocrystalline apatites analogous to the mineral phase of natural bone onto their surfaces, i.e. they are bioactive. They also stimulate osteoblast proliferation and differentiation and, therefore, accelerate the healing processes. Silica-based ordered mesoporous materials are excellent candidates to be used as third generation bioceramics that enable the adsorption and local control release of biological active agents that promote bone regeneration. This local delivery capability together with the bioactive behavior of mesoporous silicas opens up promising expectations in the bioclinical field. In this review, the last advances in nanochemistry aimed at designing and tailoring the chemical and textural properties of mesoporous silicas for biomedical applications are described. The recent developed strategies to synthesize bioactive glasses with ordered mesopore arrangements are also summarized. Finally, a deep discussion about the influence of the textural parameters and organic modification of mesoporous silicas on molecules adsorption and controlled release is performed.

  18. Immunotherapy for Bone and Soft Tissue Sarcomas

    Directory of Open Access Journals (Sweden)

    Takenori Uehara

    2015-01-01

    Full Text Available Although multimodal therapies including surgery, chemotherapy, and radiotherapy have improved clinical outcomes of patients with bone and soft tissue sarcomas, the prognosis of patients has plateaued over these 20 years. Immunotherapies have shown the effectiveness for several types of advanced tumors. Immunotherapies, such as cytokine therapies, vaccinations, and adoptive cell transfers, have also been investigated for bone and soft tissue sarcomas. Cytokine therapies with interleukin-2 or interferons have limited efficacy because of their cytotoxicities. Liposomal muramyl tripeptide phosphatidylethanolamine (L-MTP-PE, an activator of the innate immune system, has been approved as adjuvant therapeutics in combination with conventional chemotherapy in Europe, which has improved the 5-year overall survival of patients. Vaccinations and transfer of T cells transduced to express chimeric antigen receptors have shown some efficacy for sarcomas. Ipilimumab and nivolumab are monoclonal antibodies designed to inhibit immune checkpoint mechanisms. These antibodies have recently been shown to be effective for patients with melanoma and also investigated for patients with sarcomas. In this review, we provide an overview of various trials of immunotherapies for bone and soft tissue sarcomas, and discuss their potential as adjuvant therapies in combination with conventional therapies.

  19. Pullulan microcarriers for bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Aydogdu, Hazal [Middle East Technical University, Department of Biomedical Engineering, Ankara 06800 (Turkey); Keskin, Dilek [Middle East Technical University, Department of Biomedical Engineering, Ankara 06800 (Turkey); Middle East Technical University, Department of Engineering Sciences, Ankara 06800 (Turkey); METU BIOMATEN Center of Excellence in Biomaterials and Tissue Engineering, Ankara 06800 (Turkey); Baran, Erkan Turker, E-mail: erkanturkerbaran@gmail.com [METU BIOMATEN Center of Excellence in Biomaterials and Tissue Engineering, Ankara 06800 (Turkey); Tezcaner, Aysen, E-mail: tezcaner@metu.edu.tr [Middle East Technical University, Department of Biomedical Engineering, Ankara 06800 (Turkey); Middle East Technical University, Department of Engineering Sciences, Ankara 06800 (Turkey); METU BIOMATEN Center of Excellence in Biomaterials and Tissue Engineering, Ankara 06800 (Turkey)

    2016-06-01

    Microcarrier systems offer a convenient way to repair bone defects as injectable cell carriers that can be applied with small incisions owing to their small size and spherical shape. In this study, pullulan (PULL) microspheres were fabricated and characterized as cell carriers for bone tissue engineering applications. PULL was cross-linked by trisodium trimetaphosphate (STMP) to enhance the stability of the microspheres. Improved cytocompatibility was achieved by silk fibroin (SF) coating and biomimetic mineralization on the surface by incubating in simulated body fluid (SBF). X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescent microscopy analysis confirmed biomimetic mineralization and SF coating on microspheres. The degradation analysis revealed that PULL microspheres had a slow degradation rate with 8% degradation in two weeks period indicating that the microspheres would support the formation of new bone tissue. Furthermore, the mechanical tests showed that the microspheres had a high mechanical stability that was significantly enhanced with the biomimetic mineralization. In vitro cell culture studies with SaOs-2 cells showed that cell viability was higher on SF and SBF coated microspheres on 7th day compared to PULL ones under dynamic conditions. Alkaline phosphatase activity was higher for SF coated microspheres in comparison to uncoated microspheres when dynamic culture condition was applied. The results suggest that both organic and inorganic surface modifications can be applied on PULL microspheres to prepare a biocompatible microcarrier system with suitable properties for bone tissue engineering. - Highlights: • Porous PULL microspheres were prepared as cell carrier for the first time. • Mineralization on the microspheres improved their mechanical properties. • Mineralization and SF coating enhanced cell proliferation on PULL microspheres.

  20. Mechanotransduction by bone cells in vitro: mechanobiology of bone tissue

    NARCIS (Netherlands)

    Mullender, M.; El Haj, A.J.; Yang, Y.; van Duin, M.A.; Burger, E.H.; Klein-Nulend, J.

    2004-01-01

    Mechanical force plays an important role in the regulation of bone remodelling in intact bone and bone repair. In vitro, bone cells demonstrate a high responsiveness to mechanical stimuli. Much debate exists regarding the critical components in the load profile and whether different components, such

  1. Powder-based 3D printing for bone tissue engineering.

    Science.gov (United States)

    Brunello, G; Sivolella, S; Meneghello, R; Ferroni, L; Gardin, C; Piattelli, A; Zavan, B; Bressan, E

    2016-01-01

    Bone tissue engineered 3-D constructs customized to patient-specific needs are emerging as attractive biomimetic scaffolds to enhance bone cell and tissue growth and differentiation. The article outlines the features of the most common additive manufacturing technologies (3D printing, stereolithography, fused deposition modeling, and selective laser sintering) used to fabricate bone tissue engineering scaffolds. It concentrates, in particular, on the current state of knowledge concerning powder-based 3D printing, including a description of the properties of powders and binder solutions, the critical phases of scaffold manufacturing, and its applications in bone tissue engineering. Clinical aspects and future applications are also discussed.

  2. Printing bone : the application of 3D fiber deposition for bone tissue engineering

    NARCIS (Netherlands)

    Fedorovich, N.E.

    2011-01-01

    Bone chips are used by orthopaedic surgeons for treating spinal trauma and to augment large bone defects. A potential alternative to autologous bone is regeneration of bone tissue in the lab by developing hybrid implants consisting of osteogenic (stem) cells seeded on supportive matrices. Applicatio

  3. Biology of Bone Tissue: Structure, Function, and Factors That Influence Bone Cells.

    Science.gov (United States)

    Florencio-Silva, Rinaldo; Sasso, Gisela Rodrigues da Silva; Sasso-Cerri, Estela; Simões, Manuel Jesus; Cerri, Paulo Sérgio

    2015-01-01

    Bone tissue is continuously remodeled through the concerted actions of bone cells, which include bone resorption by osteoclasts and bone formation by osteoblasts, whereas osteocytes act as mechanosensors and orchestrators of the bone remodeling process. This process is under the control of local (e.g., growth factors and cytokines) and systemic (e.g., calcitonin and estrogens) factors that all together contribute for bone homeostasis. An imbalance between bone resorption and formation can result in bone diseases including osteoporosis. Recently, it has been recognized that, during bone remodeling, there are an intricate communication among bone cells. For instance, the coupling from bone resorption to bone formation is achieved by interaction between osteoclasts and osteoblasts. Moreover, osteocytes produce factors that influence osteoblast and osteoclast activities, whereas osteocyte apoptosis is followed by osteoclastic bone resorption. The increasing knowledge about the structure and functions of bone cells contributed to a better understanding of bone biology. It has been suggested that there is a complex communication between bone cells and other organs, indicating the dynamic nature of bone tissue. In this review, we discuss the current data about the structure and functions of bone cells and the factors that influence bone remodeling.

  4. Natural Polymer-Cell Bioconstructs for Bone Tissue Engineering.

    Science.gov (United States)

    Titorencu, Irina; Albu, Madalina Georgiana; Nemecz, Miruna; Jinga, Victor V

    2017-01-01

    The major goal of bone tissue engineering is to develop bioconstructs which substitute the functionality of damaged natural bone structures as much as possible if critical-sized defects occur. Scaffolds that mimic the structure and composition of bone tissue and cells play a pivotal role in bone tissue engineering applications. First, composition, properties and in vivo synthesis of bone tissue are presented for the understanding of bone formation. Second, potential sources of osteoprogenitor cells have been investigated for their capacity to induce bone repair and regeneration. Third, taking into account that the main property to qualify one scaffold as a future bioconstruct for bone tissue engineering is the biocompatibility, the assessments which prove it are reviewed in this paper. Forth, various types of natural polymer- based scaffolds consisting in proteins, polysaccharides, minerals, growth factors etc, are discussed, and interaction between scaffolds and cells which proved bone tissue engineering concept are highlighted. Finally, the future perspectives of natural polymer-based scaffolds for bone tissue engineering are considered.

  5. Biodegradable Polymers in Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Leon E. Govaert

    2009-07-01

    Full Text Available The use ofdegradable polymers in medicine largely started around the mid 20th century with their initial use as in vivo resorbing sutures. Thorough knowledge on this topic as been gained since then and the potential applications for these polymers were, and still are, rapidly expanding. After improving the properties of lactic acid-based polymers, these were no longer studied only from a scientific point of view, but also for their use in bone surgery in the 1990s. Unfortunately, after implanting these polymers, different foreign body reactions ranging from the presence of white blood cells to sterile sinuses with resorption of the original tissue were observed. This led to the misconception that degradable polymers would, in all cases, lead to inflammation and/or osteolysis at the implantation site. Nowadays, we have accumulated substantial knowledge on the issue of biocompatibility of biodegradable polymers and are able to tailor these polymers for specific applications and thereby strongly reduce the occurrence of adverse tissue reactions. However, the major issue of biofunctionality, when mechanical adaptation is taken into account, has hitherto been largely unrecognized. A thorough understanding of how to improve the biofunctionality, comprising biomechanical stability, but also visualization and sterilization of the material, together with the avoidance of fibrotic tissue formation and foreign body reactions, may greatly enhance the applicability and safety of degradable polymers in a wide area of tissue engineering applications. This review will address our current understanding of these biofunctionality factors, and will subsequently discuss the pitfalls remaining and potential solutions to solve these problems.

  6. The Use of Adipose Tissue-Derived Progenitors in Bone Tissue Engineering - a Review

    Science.gov (United States)

    Bhattacharya, Indranil; Ghayor, Chafik; Weber, Franz E.

    2016-01-01

    2500 years ago, Hippocrates realized that bone can heal without scaring. The natural healing potential of bone is, however, restricted to small defects. Extended bone defects caused by trauma or during tumor resections still pose a huge problem in orthopedics and cranio-maxillofacial surgery. Bone tissue engineering strategies using stem cells, growth factors, and scaffolds could overcome the problems with the treatment of extended bone defects. In this review, we give a short overview on bone tissue engineering with emphasis on the use of adipose tissue-derived stem cells and small molecules.

  7. Non-viral gene therapy for bone tissue engineering

    NARCIS (Netherlands)

    Wegman, F.

    2013-01-01

    In bone tissue engineering bone morphogentic protein-2 (BMP-2) is one of the most commonly used growth factors. It induces stem cells to differentiate into the osteogenic lineage to form new bone. Clinically however, high dosages of protein are administered due to fast degradation, which is associat

  8. Tissue reaction and material characteristics of four bone substitutes

    DEFF Research Database (Denmark)

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

    1996-01-01

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

  9. Interactions between remodelling, architecture and tissue properties in cancellous bone

    NARCIS (Netherlands)

    J.C. van der Linden (Jacqueline)

    2003-01-01

    textabstractThe aim of the research projects described in this thesis was to gain more insight in the regulation of bone remodeling and in the interactions between bone remodeling, architecture and bone tissue properties. The most striking changes during aging and osteoporosis take place in cancello

  10. Residual stress in bone structure and tissue of rabbit's tibiofibula.

    Science.gov (United States)

    Tadano, Shigeru; Okoshi, Taro

    2006-01-01

    This paper presents an X-ray diffraction method of measuring the residual stress/strain in bone tissue of rabbit's tibia. To derive the residual stress, bone powder of the diameter less than 40 micrometers was used as a control specimen at non-stressed state. From the X-ray measurements, it was clear that the distribution of residual stress existed in the bone tissue. The tensile residual stress at bone axial direction occurred in the proximal-medial region of rabbit's tibia. The compressive stress occurred in the other regions. In addition, the mechanism to generate the residual stress was investigated by sequential cutting of the tibiofibula system from bone structure scale to bone tissue scale. The remodeling is a phenomenon that the bone structure adapts functionally to mechanical environment. The residual stress will become a mechanical trigger to induce the remodeling.

  11. A bioreactor system for clinically relevant bone tissue engineering

    NARCIS (Netherlands)

    Janssen, Franciscus Wilhelmus

    2010-01-01

    Tissue engineering of bone by combining mesenchymal stem cells (MSCs) with a suitable ceramic carrier provides a potential alternative for autologous bone grafts. However, for large scale-production, the current two dimensional (2D) multiplication process in tissue culture flasks has some serious dr

  12. Sinusoidal electromagnetic fields promote bone formation and inhibit bone resorption in rat femoral tissues in vitro.

    Science.gov (United States)

    Zhou, Jian; Ma, Xiao-Ni; Gao, Yu-Hai; Yan, Juan-Li; Shi, Wen-Gui; Xian, Cory J; Chen, Ke-Ming

    2016-01-01

    Effects of sinusoidal electromagnetic fields (SEMFs) on bone metabolism have not yet been well defined. The present study investigated SEMF effects on bone formation and resorption in rat femur bone tissues in vitro. Cultured femur diaphyseal (cortical bone) and metaphyseal (trabecular bone) tissues were treated with 50 Hz 1.8 mT SEMFs 1.5 h per day for up to 12 days and treatment effects on bone formation and resorption markers and associated gene expression were examined. Treatment with SEMFs caused a significant increase in alkaline phosphatase (ALP) activity and inhibited the tartrate-resistant acid phosphatase (TRACP) activity in the femoral diaphyseal or metaphyseal tissues. SEMFs also significantly increased levels of mRNA expression of osterix (OSX), insulin-like growth factor (IGF-1) and ALP in the bone tissues. SEMF treatment decreased glucose content and increased lactic acid contents in the culture conditioned medium. In addition, treatment with SEMFs decreased mRNA expression levels of bone resorption-related genes TRACP, macrophage colony stimulating factor (M-CSF) and cathepsin K (CTSK) in the cultured bone tissues. In conclusion, the current study demonstrated that treatment with 1.8 mT SEMFs at 1.5 h per day promoted bone formation, increased metabolism and inhibited resorption in both metaphyseal and diaphyseal bone tissues in vitro.

  13. A new biological approach to guided bone and tissue regeneration.

    Science.gov (United States)

    Montanari, Marco; Callea, Michele; Yavuz, Izzet; Maglione, Michele

    2013-04-09

    The purpose of this study was to determine the potential of platelet-rich fibrin (PRF) membranes used for guided bone and tissue regeneration. A patient with insufficient alveolar ridge width in aesthetic zone was enrolled. The patient's blood was centrifuged to obtain PRF membranes. Autogenous bone graft was mixed with bovine hydroxyapatite, PRF particles and applied to fill the defect. Five PRF membranes were placed over the bone mix. After 4 months a cone-beam CT was performed to evaluate bone regeneration. The use of PRF as cover membrane permitted a rapid epithelisation and represented an effective barrier versus epithelial cell penetration. After 4 months the site appeared precociously healed and the bone volume increased. This new approach represents a predictable method of augmenting deficient alveolar ridges. Guided bone regeneration with PRF showed limitation compared with guided bone regeneration using collagen membrane in terms of bone gain. The association of collagen membrane and PRF could be a good association.

  14. Nanomechanical mapping of bone tissue regenerated by magnetic scaffolds.

    Science.gov (United States)

    Bianchi, Michele; Boi, Marco; Sartori, Maria; Giavaresi, Gianluca; Lopomo, Nicola; Fini, Milena; Dediu, Alek; Tampieri, Anna; Marcacci, Maurilio; Russo, Alessandro

    2015-01-01

    Nanoindentation can provide new insights on the maturity stage of regenerating bone. The aim of the present study was the evaluation of the nanomechanical properties of newly-formed bone tissue at 4 weeks from the implantation of permanent magnets and magnetic scaffolds in the trabecular bone of rabbit femoral condyles. Three different groups have been investigated: MAG-A (NdFeB magnet + apatite/collagen scaffold with magnetic nanoparticles directly nucleated on the collagen fibers during scaffold synthesis); MAG-B (NdFeB magnet + apatite/collagen scaffold later infiltrated with magnetic nanoparticles) and MAG (NdFeB magnet). The mechanical properties of different-maturity bone tissues, i.e. newly-formed immature, newly-formed mature and native trabecular bone have been evaluated for the three groups. Contingent correlations between elastic modulus and hardness of immature, mature and native bone have been examined and discussed, as well as the efficacy of the adopted regeneration method in terms of "mechanical gap" between newly-formed and native bone tissue. The results showed that MAG-B group provided regenerated bone tissue with mechanical properties closer to that of native bone compared to MAG-A or MAG groups after 4 weeks from implantation. Further, whereas the mechanical properties of newly-formed immature and mature bone were found to be fairly good correlated, no correlation was detected between immature or mature bone and native bone. The reported results evidence the efficacy of nanoindentation tests for the investigation of the maturity of newly-formed bone not accessible through conventional analyses.

  15. Alginate composites for bone tissue engineering: a review.

    Science.gov (United States)

    Venkatesan, Jayachandran; Bhatnagar, Ira; Manivasagan, Panchanathan; Kang, Kyong-Hwa; Kim, Se-Kwon

    2015-01-01

    Bone is a complex and hierarchical tissue consisting of nano hydroxyapatite and collagen as major portion. Several attempts have been made to prepare the artificial bone so as to replace the autograft and allograft treatment. Tissue engineering is a promising approach to solve the several issues and is also useful in the construction of artificial bone with materials including polymer, ceramics, metals, cells and growth factors. Composites consisting of polymer-ceramics, best mimic the natural functions of bone. Alginate, an anionic polymer owing enormous biomedical applications, is gaining importance particularly in bone tissue engineering due to its biocompatibility and gel forming properties. Several composites such as alginate-polymer (PLGA, PEG and chitosan), alginate-protein (collagen and gelatin), alginate-ceramic, alginate-bioglass, alginate-biosilica, alginate-bone morphogenetic protein-2 and RGD peptides composite have been investigated till date. These alginate composites show enhanced biochemical significance in terms of porosity, mechanical strength, cell adhesion, biocompatibility, cell proliferation, alkaline phosphatase increase, excellent mineralization and osteogenic differentiation. Hence, alginate based composite biomaterials will be promising for bone tissue regeneration. This review will provide a broad overview of alginate preparation and its applications towards bone tissue engineering.

  16. Chitosan Composites for Bone Tissue Engineering—An Overview

    Directory of Open Access Journals (Sweden)

    Jayachandran Venkatesan

    2010-08-01

    Full Text Available Bone contains considerable amounts of minerals and proteins. Hydroxyapatite [Ca10(PO46(OH2] is one of the most stable forms of calcium phosphate and it occurs in bones as major component (60 to 65%, along with other materials including collagen, chondroitin sulfate, keratin sulfate and lipids. In recent years, significant progress has been made in organ transplantation, surgical reconstruction and the use of artificial protheses to treat the loss or failure of an organ or bone tissue. Chitosan has played a major role in bone tissue engineering over the last two decades, being a natural polymer obtained from chitin, which forms a major component of crustacean exoskeleton. In recent years, considerable attention has been given to chitosan composite materials and their applications in the field of bone tissue engineering due to its minimal foreign body reactions, an intrinsic antibacterial nature, biocompatibility, biodegradability, and the ability to be molded into various geometries and forms such as porous structures, suitable for cell ingrowth and osteoconduction. The composite of chitosan including hydroxyapatite is very popular because of the biodegradability and biocompatibility in nature. Recently, grafted chitosan natural polymer with carbon nanotubes has been incorporated to increase the mechanical strength of these composites. Chitosan composites are thus emerging as potential materials for artificial bone and bone regeneration in tissue engineering. Herein, the preparation, mechanical properties, chemical interactions and in vitro activity of chitosan composites for bone tissue engineering will be discussed.

  17. Polymeric composites containing carbon nanotubes for bone tissue engineering.

    Science.gov (United States)

    Sahithi, Kolli; Swetha, Maddela; Ramasamy, Kumarasamy; Srinivasan, Narasimhan; Selvamurugan, Nagarajan

    2010-04-01

    Several natural and synthetic polymers are now available for bone tissue engineering applications but they may lack mechanical integrity. In recent years, there are reports emphasizing the importance of carbon nanotubes (CNTs) in supporting bone growth. CNTs possess exceptional mechanical, thermal, and electrical properties, facilitating their use as reinforcements or additives in various materials to improve the properties of the materials. Biomaterials containing polymers often are placed adjacent to bone. The use of CNTs is anticipated in these biomaterials applied to bone mainly to improve their overall mechanical properties and expected to act as scaffolds to promote and guide bone tissue regeneration. This review paper provides a current state of knowledge available examining the use of the polymeric composites containing CNTs for promoting bone growth.

  18. Stem and progenitor cells: advancing bone tissue engineering.

    Science.gov (United States)

    Tevlin, R; Walmsley, G G; Marecic, O; Hu, Michael S; Wan, D C; Longaker, M T

    2016-04-01

    Unlike many other postnatal tissues, bone can regenerate and repair itself; nevertheless, this capacity can be overcome. Traditionally, surgical reconstructive strategies have implemented autologous, allogeneic, and prosthetic materials. Autologous bone--the best option--is limited in supply and also mandates an additional surgical procedure. In regenerative tissue engineering, there are myriad issues to consider in the creation of a functional, implantable replacement tissue. Importantly, there must exist an easily accessible, abundant cell source with the capacity to express the phenotype of the desired tissue, and a biocompatible scaffold to deliver the cells to the damaged region. A literature review was performed using PubMed; peer-reviewed publications were screened for relevance in order to identify key advances in stem and progenitor cell contribution to the field of bone tissue engineering. In this review, we briefly introduce various adult stem cells implemented in bone tissue engineering such as mesenchymal stem cells (including bone marrow- and adipose-derived stem cells), endothelial progenitor cells, and induced pluripotent stem cells. We then discuss numerous advances associated with their application and subsequently focus on technological advances in the field, before addressing key regenerative strategies currently used in clinical practice. Stem and progenitor cell implementation in bone tissue engineering strategies have the ability to make a major impact on regenerative medicine and reduce patient morbidity. As the field of regenerative medicine endeavors to harness the body's own cells for treatment, scientific innovation has led to great advances in stem cell-based therapies in the past decade.

  19. Pathologic bone tissues in a Turkey vulture and a nonavian dinosaur: implications for interpreting endosteal bone and radial fibrolamellar bone in fossil dinosaurs.

    Science.gov (United States)

    Chinsamy, Anusuya; Tumarkin-Deratzian, Allison

    2009-09-01

    We report on similar pathological bone microstructure in an extant turkey vulture (Cathartes aura) and a nonavian dinosaur from Transylvania. Both these individuals exhibit distinctive periosteal reactive bone deposition accompanied by endosteal bone deposits in the medullary cavity. Our findings have direct implications on the two novel bone tissues recently described among nonavian dinosaurs, radial fibrolamellar bone tissue and medullary bone tissue. On the basis of the observed morphology of the periosteal reactive bone in the turkey vulture and the Transylvanian dinosaur, we propose that the radial fibrolamellar bone tissues observed in mature dinosaurs may have had a pathological origin. Our analysis also shows that on the basis of origin, location, and morphology, pathologically derived endosteal bone tissue can be similar to medullary bone tissues described in nonavian dinosaurs. As such, we caution the interpretation of all endosteally derived bone tissue as homologous to avian medullary bone.

  20. Biomechanical researches on tissue engineering bone constructed by deproteinated bone

    Institute of Scientific and Technical Information of China (English)

    JIAN Yue-kui; TIAN Xiao-bin; LI Qi-hong; LI Bo; PENG Zhi; ZHAO Wei-feng; WANG Yuan-zheng; YANG Zhen

    2010-01-01

    Objective:To study biomechanical changes of newly formed bones 24 weeks after repairing large defects of long bones of goats using heterogeneous deproteinated bone(DPB)prepared by modified methods as an engineering scaffold.Methods:According to a fully randomized design,18 goats were evenly divided into three groups:normal bone control group(Group A),autologous bone group(Group B)and experimental group(Group C).Each goat in Groups B and C were subjected to the periosteum and bone defect at middle-lower part of the fight tibia(20% of the whole tibia in length),followed by autologous bone or DPB plus autologous MSCs + rhBMP2 implantation,respectively and semiring slot fixation;while goats in Group A did not perform osteotomy.At 24 weeks after surgery,biomechanical tests were carried out on the tibias.Results:At 24 weeks after surgery,the results of anticompression test on tibias in three groups were recorded by a functional recorder presented as linear pressure-deformation curve.The shapes of the curves and their change tendency were similar among three groups.The ultimate pressure values were 10.74 Mpa±1.23 Mpa,10.11 Mpa±1.35 Mpa and 10.22 Mpa±1.32 Mpa and fracture compression rates were 26.82%±0.87%,27.17%±0.75% and 28.22%±1.12% in Groups A,B and C,respectively.Comparisons of anti-compression ultimate pressures and fracture compression rates among three groups demonstrated no significant difference(P_(AB)=0.415,P_(BC)=0.494).Three-point antibend test on tibias was recorded as load-deformation curves,and the shapes of the curves and their change tendency were similar among three groups.The ultimate pressure values of the anti-bend test were 481.52 N±12.45 N,478.34 N±14.68 N and 475.62 N±13.41 N and the fracture bend rates were 2.62 mm±0.12 mm,2.61 mm±0.15 mm and 2.81 mm±0.13 mm in Groups A,B and C,respectively.There was no significant difference between groups(P_(AB)=0.7,P_(BC)=0.448).The ultirates were 29.51°±1.64°,28.88°±1.46° and 28.81°±1.33

  1. Biodegradable Polymer-Based Scaffolds for Bone Tissue Engineering

    CERN Document Server

    Sultana, Naznin

    2013-01-01

    This book addresses the principles, methods and applications of biodegradable polymer based scaffolds for bone tissue engineering. The general principle of bone tissue engineering is reviewed and the traditional and novel scaffolding materials, their properties and scaffold fabrication techniques are explored. By acting as temporary synthetic extracellular matrices for cell accommodation, proliferation, and differentiation, scaffolds play a pivotal role in tissue engineering. This book does not only provide the comprehensive summary of the current trends in scaffolding design but also presents the new trends and directions for scaffold development for the ever expanding tissue engineering applications.

  2. Melatonin Effects on Hard Tissues: Bone and Tooth

    Directory of Open Access Journals (Sweden)

    Hong-Wen He

    2013-05-01

    Full Text Available Melatonin is an endogenous hormone rhythmically produced in the pineal gland under the control of the suprachiasmatic nucleus (SCN and the light/dark cycle. This indole plays an important role in many physiological processes including circadian entrainment, blood pressure regulation, seasonal reproduction, ovarian physiology, immune function, etc. Recently, the investigation and applications of melatonin in the hard tissues bone and tooth have received great attention. Melatonin has been investigated relative to bone remolding, osteoporosis, osseointegration of dental implants and dentine formation. In the present review, we discuss the large body of published evidence and review data of melatonin effects on hard tissues, specifically, bone and tooth.

  3. Osteopontin: Relation between Adipose Tissue and Bone Homeostasis

    Science.gov (United States)

    Messina, Antonietta; Monda, Vincenzo; Viggiano, Emanuela; Valenzano, Anna; Esposito, Teresa; Cibelli, Giuseppe

    2017-01-01

    Osteopontin (OPN) is a multifunctional protein mainly associated with bone metabolism and remodeling. Besides its physiological functions, OPN is implicated in the pathogenesis of a variety of disease states, such as obesity and osteoporosis. Importantly, during the last decades obesity and osteoporosis have become among the main threats to health worldwide. Because OPN is a protein principally expressed in cells with multifaceted effects on bone morphogenesis and remodeling and because it seems to be one of the most overexpressed genes in the adipose tissue of the obese contributing to osteoporosis, this mini review will highlight recent insights about relation between adipose tissue and bone homeostasis.

  4. Effects of microgravity on rat bone, cartlage and connective tissues

    Science.gov (United States)

    Doty, S.

    1990-01-01

    The response to hypogravity by the skeletal system was originally thought to be the result of a reduction in weight bearing. Thus a reduced rate of new bone formation in the weight-bearing bones was accepted, when found, as an obvious result of hypogravity. However, data on non-weight-bearing tissues have begun to show that other physiological changes can be expected to occur to animals during spaceflight. This overview of the Cosmos 1887 data discusses these results as they pertain to individual bones or tissues because the response seems to depend on the architecture and metabolism of each tissue under study. Various effects were seen in different tissues from the rats flown on Cosmos 1887. The femur showed a reduced bone mineral content but only in the central region of the diaphysis. This same region in the tibia showed changes in the vascularity of bone as well as some osteocytic cell death. The humerus demonstrated reduced morphometric characteristics plus a decrease in mechanical stiffness. Bone mineral crystals did not mature normally as a result of flight, suggesting a defect in the matrix mineralization process. Note that these changes relate directly to the matrix portion of the bone or some function of bone which slowly responds to changes in the environment. However, most cellular functions of bone are rapid responders. The stimulation of osteoblast precursor cells, the osteoblast function in collagen synthesis, a change in the proliferation rate of cells in the epiphyseal growth plate, the synthesis and secretion of osteocalcin, and the movement of water into or out of tissues, are all processes which respond to environmental change. These rapidly responding events produced results from Cosmos 1887 which were frequently quite different from previous space flight data.

  5. Composites structures for bone tissue reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Neto, W.; Santos, João [Universidade Federal de São Carlos, Departament of Materials Engineering - Rd. Washington Luis, Km 235, 13565-905, São Carlos-SP (Brazil); Avérous, L.; Schlatter, G.; Bretas, Rosario, E-mail: bretas@ufscar.br [Université de Strasbourg, ECPM-LIPHT - 25 rue Becquerel, 67087, Strasbourg (France)

    2015-05-22

    The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth.

  6. Training human mesenchymal stromal cells for bone tissue engineering applications

    NARCIS (Netherlands)

    Doorn, J.

    2012-01-01

    Human mesenchymal stromal cells (hMSCs) are an interesting source for cell therapies and tissue engineering applications, because these cells are able to differentiate into various target tissues, such as bone, cartilage, fat and endothelial cells. In addition, they secrete a wide array of growth fa

  7. Silk fibroin membrane used for guided bone tissue regeneration.

    Science.gov (United States)

    Cai, Yurong; Guo, Junmao; Chen, Cen; Yao, Chenxue; Chung, Sung-Min; Yao, Juming; Lee, In-Seop; Kong, Xiangdong

    2017-01-01

    With the aim to develop a novel membrane with an appropriate mechanical property and degradation rate for guided bone tissue regeneration, lyophilized and densified silk fibroin membrane was fabricated and its mechanical behavior as well as biodegradation property were investigated. The osteoconductive potency of the silk fibroin membranes were evaluated in a defect rabbit calvarial model. Silk fibroin membrane showed the modulated biodegradable and mechanical properties via ethanol treatment with different concentration. The membrane could prevent soft tissue invasion from normal tissue healing, and the amounts of new bone and defect closure with silk fibroin membrane were similar to those of commercially available collagen membrane.

  8. Wide-field Raman imaging for bone detection in tissue

    OpenAIRE

    Papour, Asael; Kwak, Jin Hee; Taylor, Zach; Wu, Benjamin; Stafsudd, Oscar; Grundfest, Warren

    2015-01-01

    Inappropriate bone growth in soft tissue can occur after trauma to a limb and can cause a disruption to the healing process. This is known as Heterotopic Ossification (HO) in which regions in the tissue start to mineralize and form microscopic bone-like structures. These structures continue to calcify and develop into large, non-functional bony masses that cause pain, limit limb movement, and expose the tissue to reoccurring infections; in the case of open wounds this can lead to amputation a...

  9. A tissue regeneration approach to bone and cartilage repair

    CERN Document Server

    Dunstan, Colin; Rosen, Vicki

    2015-01-01

    Reviewing exhaustively the current state of the art of tissue engineering strategies for regenerating bones and joints through the use of biomaterials, growth factors and stem cells, along with an investigation of the interactions between biomaterials, bone cells, growth factors and added stem cells and how together skeletal tissues can be optimised, this book serves to highlight the importance of biomaterials composition, surface topography, architectural and mechanical properties in providing support for tissue regeneration. Maximizing reader insights into the importance of the interplay of these attributes with bone cells (osteoblasts, osteocytes and osteoclasts) and cartilage cells (chondrocytes), this book also provides a detailed reference as to how key signalling pathways are activated. The contribution of growth factors to drive tissue regeneration and stem cell recruitment is discussed along with a review the potential and challenges of adult or embryonic mesenchymal stem cells to further enhance the...

  10. Bone Tissue in Down Syndrome Patients Deteriorates Following Aging: A Study Based on Bone Ultrasound Analysis

    Directory of Open Access Journals (Sweden)

    Mirela Gavris

    2014-03-01

    Conclusion: This study showed that BUA is sufficiently sensitive to highlight the bone degradation that occurs at the end of adolescence and in adulthood in individuals with DS. In addition, BUA and stabilometric performances were able to distinguish DS patients from controls in the two older age groups, indicating that bone tissue and postural control of DS patients deteriorate with aging.

  11. Localized tissue mineralization regulated by bone remodelling: A computational approach

    Science.gov (United States)

    Decco, Oscar; Adams, George; Cook, Richard B.; García Aznar, José Manuel

    2017-01-01

    Bone is a living tissue whose main mechanical function is to provide stiffness, strength and protection to the body. Both stiffness and strength depend on the mineralization of the organic matrix, which is constantly being remodelled by the coordinated action of the bone multicellular units (BMUs). Due to the dynamics of both remodelling and mineralization, each sample of bone is composed of structural units (osteons in cortical and packets in cancellous bone) created at different times, therefore presenting different levels of mineral content. In this work, a computational model is used to understand the feedback between the remodelling and the mineralization processes under different load conditions and bone porosities. This model considers that osteoclasts primarily resorb those parts of bone closer to the surface, which are younger and less mineralized than older inner ones. Under equilibrium loads, results show that bone volumes with both the highest and the lowest levels of porosity (cancellous and cortical respectively) tend to develop higher levels of mineral content compared to volumes with intermediate porosity, thus presenting higher material densities. In good agreement with recent experimental measurements, a boomerang-like pattern emerges when plotting apparent density at the tissue level versus material density at the bone material level. Overload and disuse states are studied too, resulting in a translation of the apparent–material density curve. Numerical results are discussed pointing to potential clinical applications. PMID:28306746

  12. Whole Body Bone Tissue and Cardiovascular Risk in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Claudiu Popescu

    2014-01-01

    Full Text Available Introduction. Atherosclerosis and osteoporosis share an age-independent bidirectional correlation. Rheumatoid arthritis (RA represents a risk factor for both conditions. Objectives. The study aims to evaluate the connection between the estimated cardiovascular risk (CVR and the loss of bone tissue in RA patients. Methods. The study has a prospective cross-sectional design and it includes female in-patients with RA or without autoimmune diseases; bone tissue was measured using whole body dual X-ray absorptiometry (wbDXA; CVR was estimated using SCORE charts and PROCAM applications. Results. There were 75 RA women and 66 normal women of similar age. The wbDXA bone indices correlate significantly, negatively, and age-independently with the estimated CVR. The whole body bone percent (wbBP was a significant predictor of estimated CVR, explaining 26% of SCORE variation along with low density lipoprotein (P < 0.001 and 49.7% of PROCAM variation along with glycemia and menopause duration (P < 0.001. Although obese patients had less bone relative to body composition (wbBP, in terms of quantity their bone content was significantly higher than that of nonobese patients. Conclusions. Female patients with RA and female patients with cardiovascular morbidity have a lower whole body bone percent. Obese female individuals have higher whole body bone mass than nonobese patients.

  13. Building bone tissue: matrices and scaffolds in physiology and biotechnology

    Directory of Open Access Journals (Sweden)

    Riminucci M.

    2003-01-01

    Full Text Available Deposition of bone in physiology involves timed secretion, deposition and removal of a complex array of extracellular matrix proteins which appear in a defined temporal and spatial sequence. Mineralization itself plays a role in dictating and spatially orienting the deposition of matrix. Many aspects of the physiological process are recapitulated in systems of autologous or xenogeneic transplantation of osteogenic precursor cells developed for tissue engineering or modeling. For example, deposition of bone sialoprotein, a member of the small integrin-binding ligand, N-linked glycoprotein family, represents the first step of bone formation in ectopic transplantation systems in vivo. The use of mineralized scaffolds for guiding bone tissue engineering has revealed unexpected manners in which the scaffold and cells interact with each other, so that a complex interplay of integration and disintegration of the scaffold ultimately results in efficient and desirable, although unpredictable, effects. Likewise, the manner in which biomaterial scaffolds are "resorbed" by osteoclasts in vitro and in vivo highlights more complex scenarios than predicted from knowledge of physiological bone resorption per se. Investigation of novel biomaterials for bone engineering represents an essential area for the design of tissue engineering strategies.

  14. Cell Mechanisms of Bone Tissue Loss Under Space Flight Conditions

    Science.gov (United States)

    Rodionova, Natalia

    Investigations on the space biosatellites has shown that the bone skeleton is one of the most im-portant targets of the effect space flight factors on the organism. Bone tissue cells were studied by electron microscopy in biosamples of rats' long bones flown on the board american station "SLS-2" and in experiments with modelling of microgravity ("tail suspension" method) with using autoradiography. The analysis of data permits to suppose that the processes of remod-eling in bone tissue at microgravity include the following succession of cell-to-cell interactions. Osteocytes as mechanosensory cells are first who respond to a changing "mechanical field". The next stage is intensification of osteolytic processes in osteocytes, leading to a volume en-largement of the osteocytic lacunae and removal of the "excess bone". Then mechanical signals have been transmitted through a system of canals and processes of the osteocytic syncitium to certain superficial bone zones and are perceived by osteoblasts and bone-lining cells (superficial osteocytes), as well as by the bone-marrow stromal cells. The sensitivity of stromal cells, pre-osteoblasts and osteoblasts, under microgravity was shown in a number of works. As a response to microgravity, the system of stromal cells -preosteoblasts -osteoblasts displays retardation of proliferation, differentiation and specific functions of osteogenetic cells. This is supported by the 3H-thymidine studies of the dynamics of differentiation of osteogenetic cells in remodeling zones. But unloading is not adequate and in part of the osteocytes are apoptotic changes as shown by our electron microscopic investigations. An osteocytic apoptosis can play the role in attraction the osteoclasts and in regulation of bone remodeling. The apoptotic bodies with a liquid flow through a system of canals are transferred to the bone surface, where they fulfil the role of haemoattractants for monocytes come here and form osteoclasts. The osteoclasts destroy

  15. Multiscale patterned transplantable stem cell patches for bone tissue regeneration.

    Science.gov (United States)

    Kim, Jangho; Bae, Won-Gyu; Choung, Han-Wool; Lim, Ki Taek; Seonwoo, Hoon; Jeong, Hoon Eui; Suh, Khap-Yang; Jeon, Noo Li; Choung, Pill-Hoon; Chung, Jong Hoon

    2014-11-01

    Stem cell-based therapy has been proposed as an enabling alternative not only for the treatment of diseases but also for the regeneration of tissues beyond complex surgical treatments or tissue transplantation. In this study, we approached a conceptual platform that can integrate stem cells into a multiscale patterned substrate for bone regeneration. Inspired by human bone tissue, we developed hierarchically micro- and nanopatterned transplantable patches as synthetic extracellular matrices by employing capillary force lithography in combination with a surface micro-wrinkling method using a poly(lactic-co-glycolic acid) (PLGA) polymer. The multiscale patterned PLGA patches were highly flexible and showed higher tissue adhesion to the underlying tissue than did the single nanopatterned patches. In response to the anisotropically multiscale patterned topography, the adhesion and differentiation of human mesenchymal stem cells (hMSCs) were sensitively controlled. Furthermore, the stem cell patch composed of hMSCs and transplantable PLGA substrate promoted bone regeneration in vivo when both the micro- and nanotopography of the substrate surfaces were synergistically combined. Thus, our study concludes that multiscale patterned transplantable stem cell patches may have a great potential for bone regeneration as well as for various regenerative medicine approaches.

  16. Bone Marrow Adipose Tissue: To Be or Not To Be a Typical Adipose Tissue?

    Science.gov (United States)

    Hardouin, Pierre; Rharass, Tareck; Lucas, Stéphanie

    2016-01-01

    Bone marrow adipose tissue (BMAT) emerges as a distinct fat depot whose importance has been proved in the bone-fat interaction. Indeed, it is well recognized that adipokines and free fatty acids released by adipocytes can directly or indirectly interfere with cells of bone remodeling or hematopoiesis. In pathological states, such as osteoporosis, each of adipose tissues - subcutaneous white adipose tissue (WAT), visceral WAT, brown adipose tissue (BAT), and BMAT - is differently associated with bone mineral density (BMD) variations. However, compared with the other fat depots, BMAT displays striking features that makes it a substantial actor in bone alterations. BMAT quantity is well associated with BMD loss in aging, menopause, and other metabolic conditions, such as anorexia nervosa. Consequently, BMAT is sensed as a relevant marker of a compromised bone integrity. However, analyses of BMAT development in metabolic diseases (obesity and diabetes) are scarce and should be, thus, more systematically addressed to better apprehend the bone modifications in that pathophysiological contexts. Moreover, bone marrow (BM) adipogenesis occurs throughout the whole life at different rates. Following an ordered spatiotemporal expansion, BMAT has turned to be a heterogeneous fat depot whose adipocytes diverge in their phenotype and their response to stimuli according to their location in bone and BM. In vitro, in vivo, and clinical studies point to a detrimental role of BM adipocytes (BMAs) throughout the release of paracrine factors that modulate osteoblast and/or osteoclast formation and function. However, the anatomical dissemination and the difficulties to access BMAs still hamper our understanding of the relative contribution of BMAT secretions compared with those of peripheral adipose tissues. A further characterization of the phenotype and the functional regulation of BMAs are ever more required. Based on currently available data and comparison with other fat tissues

  17. Mechanochemical synthesis evaluation of nanocrystalline bone-derived bioceramic powder using for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Amirsalar Khandan

    2014-01-01

    Full Text Available Introduction: Bone tissue engineering proposes a suitable way to regenerate lost bones. Different materials have been considered for use in bone tissue engineering. Hydroxyapatite (HA is a significant success of bioceramics as a bone tissue repairing biomaterial. Among different bioceramic materials, recent interest has been risen on fluorinated hydroxyapatites, (FHA, Ca 10 (PO 4 6 F x (OH 2−x . Fluorine ions can promote apatite formation and improve the stability of HA in the biological environments. Therefore, they have been developed for bone tissue engineering. The aim of this study was to synthesize and characterize the FHA nanopowder via mechanochemical (MC methods. Materials and Methods: Natural hydroxyapatite (NHA 95.7 wt.% and calcium fluoride (CaF 2 powder 4.3 wt.% were used for synthesis of FHA. MC reaction was performed in the planetary milling balls using a porcelain cup and alumina balls. Ratio of balls to reactant materials was 15:1 at 400 rpm rotation speed. The structures of the powdered particles formed at different milling times were evaluated by X-ray diffraction (XRD, scanning electron microscopy (SEM and transmission electron microscopy (TEM. Results: Fabrication of FHA from natural sources like bovine bone achieved after 8 h ball milling with pure nanopowder. Conclusion: F− ion enhances the crystallization and mechanical properties of HA in formation of bone. The produced FHA was in nano-scale, and its crystal size was about 80-90 nm with sphere distribution in shape and size. FHA powder is a suitable biomaterial for bone tissue engineering.

  18. Evaluation of bone tissue reaction in laser beamed implants

    Energy Technology Data Exchange (ETDEWEB)

    Allegrini, Sergio, E-mail: sergiojr@usp.br [Graduate Program in Biodentistry, Ibirapuera University (UNIB), São Paulo, SP, 04661 100 (Brazil); Yoshimoto, Marcelo [Graduate Program in Biodentistry, Ibirapuera University (UNIB), São Paulo, SP, 04661 100 (Brazil); Salles, Marcos Barbosa [Department of Oral and Maxillofacial Surgery, Nove de Julho University (UNINOVE), São Paulo, SP, 02117 010 (Brazil); Allegrini, Marcia Rivellino Facci [São Paulo Fire Department (SPFD) of the Militar Police, Dentistry Section, São Paulo, SP, 01018 001 (Brazil); Pistarini, Luciana Crepaldi Yazawa; Braga, Francisco Jose Correa; Bressiani, Ana Helena de Almeida [Nuclear and Energy Research Institute – IPEN/USP, São Paulo, SP, 05508 900 (Brazil)

    2014-07-01

    The purpose of this study was to evaluate alterations and bone tissue response on laser treated implant surfaces (Nd:YAG – 100 W). Sixty grade II titanium (ASTM F67) mini-implants (1.5 mm × 4.0 mm) were installed in femurs of 30 Wistar rats. The animals were divided into two groups: thirty mini-implants were machined elements (Machined Group) and the other thirty had laser beamed surfaces (Laser Group). The animals were subdivided into three groups, according to bone healing periods of 15, 30 and 60 days. The samples were analyzed under light, scanning electron and confocal 3D microscopy as well as by EDS (energy dispersive spectroscopy) and Student's t test was used for statistical analyses. Light microscopy results showed new bone trabeculae formation toward laser-treated implants at 15 days’ bone repair as well as thin layers of osteoid matrix, indicating high biocompatibility. Similar features were observed in the Machined Group but only after 30 days. Bone/implant contact was better evidenced on laser-treated surfaces compared to that on simply machined implants. The only group that demonstrated change in level of significance was the laser-treated group at the 15-day-healing period (p < 0.05). Higher oxygen concentration possibly provides more efficient response of osteoblasts during new bone tissue deposition. Implant treated surfaces altered by laser beaming, their composition, surface topography and surface energy may be the future scene in implant dentistry.

  19. Biomechanical Models and Experi ments in Bone Tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    Christian; ODDOU; Julien; PIERRE; Karim; OUDINA; Hervé; PETITE

    2005-01-01

    1 IntroductionThe understanding of the interactions between convective and diffusive phenomena of fluid dynamics origin, on the one side, associate reactive effects of biochemical nature, on the other, is a fundamental challenge and key problem in the context of bone tissue engineering. From the mastering of the complex biological phenomena related to the substrate degradation and remodelling of the extra cellular matrix that take place during the in vitro tissue culturing processes using cell seeded implan...

  20. Quantitative polarized Raman spectroscopy in highly turbid bone tissue

    Science.gov (United States)

    Raghavan, Mekhala; Sahar, Nadder D.; Wilson, Robert H.; Mycek, Mary-Ann; Pleshko, Nancy; Kohn, David H.; Morris, Michael D.

    2010-05-01

    Polarized Raman spectroscopy allows measurement of molecular orientation and composition and is widely used in the study of polymer systems. Here, we extend the technique to the extraction of quantitative orientation information from bone tissue, which is optically thick and highly turbid. We discuss multiple scattering effects in tissue and show that repeated measurements using a series of objectives of differing numerical apertures can be employed to assess the contributions of sample turbidity and depth of field on polarized Raman measurements. A high numerical aperture objective minimizes the systematic errors introduced by multiple scattering. We test and validate the use of polarized Raman spectroscopy using wild-type and genetically modified (oim/oim model of osteogenesis imperfecta) murine bones. Mineral orientation distribution functions show that mineral crystallites are not as well aligned (p0.05). We provide evidence that simultaneous quantitative measurements of mineral and collagen orientations on intact bone specimens are possible using polarized Raman spectroscopy.

  1. Biomechanical study of the bone tissue with dental implants interaction

    Directory of Open Access Journals (Sweden)

    Navrátil P.

    2011-12-01

    Full Text Available The article deals with the stress-strain analysis of human mandible in the physiological state and after the dental implant application. The evaluation is focused on assessing of the cancellous bone tissue modeling-level. Three cancellous bone model-types are assessed: Non-trabecular model with homogenous isotropic material, nontrabecular model with inhomogeneous material obtained from computer tomography data using CT Data Analysis software, and trabecular model built from mandible section image. Computational modeling was chosen as the most suitable solution method and the solution on two-dimensional level was carried out. The results show that strain is more preferable value than stress in case of evaluation of mechanical response in cancellous bone. The non-trabecular model with CT-obtained material model is not acceptable for stress-strain analysis of the cancellous bone for singularities occurring on interfaces of regions with different values of modulus of elasticity.

  2. Effect of the "protein diet" and bone tissue

    Directory of Open Access Journals (Sweden)

    Zoraide Nascimento da Silva

    2014-01-01

    Full Text Available The aim of this study is to evaluate the effect of the hyperproteic diet consumption on bone tissue. Methods: The study was conducted during sixty days. Twenty eight Wistar albinus rats, adults, originated from Laboratory of Experimental Nutrition were divided in four groups: (n = 7; Control 1 (C1, Control 2 (C2, Hyperproteic 1 (HP1 e Hyperproteic 2 (HP2. The C2 and HP2 groups were submitted to 30% of food restriction. The hyperproteic diet was based on the Atkins diet and prepared to simulate the protein diet. At the end of the study the animals were anesthetized to performer bone densitometry analyses by DEXA and blood and tissue collection. Serum and bone minerals analyses were conducted by colorimetric methods in automated equipment. Results: The total bone mineral density (BMD of the pelvis and the spine of the food restriction groups (HP2 e C2 were lower (p < 0.05 than C1 e HP1 groups. While the femur BMD of the HP2 was lower (p < 0.05 related to others groups. It had been observed reduction (p < 0.05 in the medium point of the width of femur diaphysis and in bone calcium level in the hyperproteic groups (HP1 e HP2. It was observed similar effect on the osteocalcin level, that presented lower (p < 0.05 in the hyperproteic groups. The insulin level was lower only in HP2 and serum calcium of the HP1 and HP2 groups was lower than C1. Conclusion: The protein diet promotes significant bone change on femur and in the hormones levels related to bone synthesis and maintenance of this tissue.

  3. The effect of bone displacement operations on facial soft tissues.

    Science.gov (United States)

    Habib, Ali; Hisham, Ahmed

    2013-01-01

    A novel biomechanical model for face soft tissue (skin, mucosa, and muscles) is introduced to investigate the effect of mandible and chin bone displacement on the overall appearance of the patient's face. Nonlinear FE analysis is applied to the model and the results obtained are used to help surgeons to decide the amount of displacement required.

  4. Wide-field Raman imaging for bone detection in tissue.

    Science.gov (United States)

    Papour, Asael; Kwak, Jin Hee; Taylor, Zach; Wu, Benjamin; Stafsudd, Oscar; Grundfest, Warren

    2015-10-01

    Inappropriate bone growth in soft tissue can occur after trauma to a limb and can cause a disruption to the healing process. This is known as Heterotopic Ossification (HO) in which regions in the tissue start to mineralize and form microscopic bone-like structures. These structures continue to calcify and develop into large, non-functional bony masses that cause pain, limit limb movement, and expose the tissue to reoccurring infections; in the case of open wounds this can lead to amputation as a result of a failed wound. Both Magnetic Resonance Imaging (MRI) and X-ray imaging have poor sensitivity and specificity for the detection of HO, thus delaying therapy and leading to poor patient outcomes. We present a low-power, fast (1 frame per second) optical Raman imaging system with a large field of view (1 cm(2)) that can differentiate bone tissue from soft tissue without spectroscopy, this in contrast to conventional Raman microscopy systems. This capability may allow for the development of instrumentation which permits bedside diagnosis of HO.

  5. Efficient biomarkers for the characterization of bone tissue.

    Science.gov (United States)

    Gil, J E; Aranda, J P; Mérida-Casermeiro, E; Ujaldón, M

    2012-12-01

    This work describes an expert system aimed to an accurate classification of cell tissue on microscopic images coming from studies of bone tissue regeneration from stem cells. We analyze a wide number of phenotype and color issues to build effective vectors of features for the subsequent characterization of tissue into five different classes: bone, cartilage, muscle, fiber and spine. The features selection includes texture, shape and color descriptors, among which we consider color histograms, Zernike moments and circular parameters. Once a preliminary set of vectors candidates are selected, several trained and non-parametric classifiers based on neural networks, decision trees, Bayesian classifiers and association rules are analyzed, and later compared with unsupervised methods to determine those that fit more closely to our needs for distinguishing bone tissue. Because of the high resolution of our biomedical images, we effectively decompose them into smaller windows for a faster execution, with the impact of the window size being discussed in terms of speed and robustness. Our final study compares accuracy and computational time together with different stainings for revealing tissue properties: Picrosirius red, alcian blue and safranin blue. Overall, safranin blue reveals as the best staining and multilayer perceptron as the most effective classifier.

  6. Immature muscular tissue differentiation into bone-like tissue by bone morphogenetic proteins in vitro, with ossification potential in vivo.

    Science.gov (United States)

    Hayashi, Tatsuhide; Kobayashi, Syuichiro; Asakura, Masaki; Kawase, Mayu; Ueno, Atsuko; Uematsu, Yasuaki; Kawai, Tatsushi

    2014-09-01

    The objective of this study was to induce bone formation from immature muscular tissue (IMT) in vitro, using bone morphogenetic proteins (BMPs) as a cytokine source and an expanded polytetrafluoroethylene (ePTFE) scaffold. In addition, cultured IMTs were implanted subcutaneously into Sprague-Dawley (SD) rats to determine their in vivo ossification potential. BMPs, extracted from bovine cortical bones, were applied to embryonic SD rat IMT cultures, before 2 weeks culture on ePTFE scaffolds. Osteoblast-like cells and osteoid tissues were partially identified by hematoxylin-eosin staining 2 weeks after culture. Collagen type I (Col-I), osteopontin (OP), and osteocalcin (OC) were detected in the osteoid tissues by immunohistochemical staining. OC gene expression remained low, but OP and Col-I were upregulated during the culture period. In vivo implanted IMTs showed slight radiopacity 1 week after implantation and strong radiopacity 2 and 3 weeks after implantation. One week after implantation, migration of numerous capillaries was observed and ossification was detected after 2 weeks by histological observation. These results suggest that IMTs are able to differentiate into bone-like tissue in vitro, with an ossification potential after implantation in vivo.

  7. Tissue engineering bone using autologous progenitor cells in the peritoneum.

    Directory of Open Access Journals (Sweden)

    Jinhui Shen

    Full Text Available Despite intensive research efforts, there remains a need for novel methods to improve the ossification of scaffolds for bone tissue engineering. Based on a common phenomenon and known pathological conditions of peritoneal membrane ossification following peritoneal dialysis, we have explored the possibility of regenerating ossified tissue in the peritoneum. Interestingly, in addition to inflammatory cells, we discovered a large number of multipotent mesenchymal stem cells (MSCs in the peritoneal lavage fluid from mice with peritoneal catheter implants. The osteogenic potential of these peritoneal progenitor cells was demonstrated by their ability to easily infiltrate decalcified bone implants, produce osteocalcin and form mineralized bone in 8 weeks. Additionally, when poly(l-lactic acid scaffolds loaded with bone morphogenetic protein-2 (a known osteogenic differentiation agent were implanted into the peritoneum, signs of osteogenesis were seen within 8 weeks of implantation. The results of this investigation support the concept that scaffolds containing BMP-2 can stimulate the formation of bone in the peritoneum via directed autologous stem and progenitor cell responses.

  8. Exercise and Regulation of Bone and Collagen Tissue Biology

    DEFF Research Database (Denmark)

    Kjaer, Michael; Jørgensen, Niklas Rye; Heinemeier, Katja

    2015-01-01

    The musculoskeletal system and its connective tissue include the intramuscular connective tissue, the myotendinous junction, the tendon, the joints with their cartilage and ligaments, and the bone; they all together play a crucial role in maintaining the architecture of the skeletal muscle......, ensuring force transmission, storing energy, protecting joint surface and stability, and ensuring the transfer of muscular forces into resulting limb movement. The musculoskeletal connective tissue structure is relatively stable, but mechanical loading and subsequent mechanotransduction and molecular...... anabolic signaling can result in some adaptation of the connective tissue, its size, its strength, and its mechanical properties, whereby it can improve its capacity by 5-20% with regular physical activity. For several of the mechanically loaded connective tissues, only limited information regarding...

  9. [Distribution of compact bone mesenchymal stem cells in lung tissue and bone marrow of mouse].

    Science.gov (United States)

    Wang, Rui-Ping; Wu, Ren-Na; Guo, Yu-Qing; Zhang, Bin; Chen, Hu

    2014-02-01

    This study was aimed to investigate the distribution of compact bone mesenchymal stem cells(MSC) marked with lentiviral plasmid pGC FU-RFP-LV in lung tissue and bone marrow of mouse. The MSC were infected by lentivirus with infection efficiency 78%, the infected MSC were injected into BALB/c mice via tail veins in concentration of 1×10(6) /mouse. The mice were randomly divided into 4 group according to 4 time points as 1, 2, 5 and 7 days. The lung tissue and bone marrow were taken and made of frozen sections and smears respectively in order to observed the distributions of MSC. The results indicated that the lentiviral infected MSC displayed phenotypes and biological characteristics which conformed to MSC by immunophenotyping analysis and induction differentiation detection. After the MSC were infected with optimal viral titer MOI = 50, the cell growth no significantly changed; the fluorescent microscopy revealed that the distributions of MSC in bone marrow on day 1, 2, 5 and 7 were 0.50 ± 0.20, 0.67 ± 0.23, 0.53 ± 0.14, 0.33 ± 0.16; those in lung tissue were 0.55 ± 0.15, 0.47 ± 0.13, 0.29 ± 0.13, 0.26 ± 0.08. It is concluded that the distribution of MSC in lung tissue reaches a peak on day 1, while distribution of MSC in bone marrow reaches a peak on day 2. The distribution of mouse MSC relates with RFP gene expression and implantation of MSC in lung tissue and bone marrow.

  10. Preparation of laponite bioceramics for potential bone tissue engineering applications.

    Directory of Open Access Journals (Sweden)

    Chuanshun Wang

    Full Text Available We report a facile approach to preparing laponite (LAP bioceramics via sintering LAP powder compacts for bone tissue engineering applications. The sintering behavior and mechanical properties of LAP compacts under different temperatures, heating rates, and soaking times were investigated. We show that LAP bioceramic with a smooth and porous surface can be formed at 800°C with a heating rate of 5°C/h for 6 h under air. The formed LAP bioceramic was systematically characterized via different methods. Our results reveal that the LAP bioceramic possesses an excellent surface hydrophilicity and serum absorption capacity, and good cytocompatibility and hemocompatibility as demonstrated by resazurin reduction assay of rat mesenchymal stem cells (rMSCs and hemolytic assay of pig red blood cells, respectively. The potential bone tissue engineering applicability of LAP bioceramic was explored by studying the surface mineralization behavior via soaking in simulated body fluid (SBF, as well as the surface cellular response of rMSCs. Our results suggest that LAP bioceramic is able to induce hydroxyapatite deposition on its surface when soaked in SBF and rMSCs can proliferate well on the LAP bioceramic surface. Most strikingly, alkaline phosphatase activity together with alizarin red staining results reveal that the produced LAP bioceramic is able to induce osteoblast differentiation of rMSCs in growth medium without any inducing factors. Finally, in vivo animal implantation, acute systemic toxicity test and hematoxylin and eosin (H&E-staining data demonstrate that the prepared LAP bioceramic displays an excellent biosafety and is able to heal the bone defect. Findings from this study suggest that the developed LAP bioceramic holds a great promise for treating bone defects in bone tissue engineering.

  11. Preparation of laponite bioceramics for potential bone tissue engineering applications.

    Science.gov (United States)

    Wang, Chuanshun; Wang, Shige; Li, Kai; Ju, Yaping; Li, Jipeng; Zhang, Yongxing; Li, Jinhua; Liu, Xuanyong; Shi, Xiangyang; Zhao, Qinghua

    2014-01-01

    We report a facile approach to preparing laponite (LAP) bioceramics via sintering LAP powder compacts for bone tissue engineering applications. The sintering behavior and mechanical properties of LAP compacts under different temperatures, heating rates, and soaking times were investigated. We show that LAP bioceramic with a smooth and porous surface can be formed at 800°C with a heating rate of 5°C/h for 6 h under air. The formed LAP bioceramic was systematically characterized via different methods. Our results reveal that the LAP bioceramic possesses an excellent surface hydrophilicity and serum absorption capacity, and good cytocompatibility and hemocompatibility as demonstrated by resazurin reduction assay of rat mesenchymal stem cells (rMSCs) and hemolytic assay of pig red blood cells, respectively. The potential bone tissue engineering applicability of LAP bioceramic was explored by studying the surface mineralization behavior via soaking in simulated body fluid (SBF), as well as the surface cellular response of rMSCs. Our results suggest that LAP bioceramic is able to induce hydroxyapatite deposition on its surface when soaked in SBF and rMSCs can proliferate well on the LAP bioceramic surface. Most strikingly, alkaline phosphatase activity together with alizarin red staining results reveal that the produced LAP bioceramic is able to induce osteoblast differentiation of rMSCs in growth medium without any inducing factors. Finally, in vivo animal implantation, acute systemic toxicity test and hematoxylin and eosin (H&E)-staining data demonstrate that the prepared LAP bioceramic displays an excellent biosafety and is able to heal the bone defect. Findings from this study suggest that the developed LAP bioceramic holds a great promise for treating bone defects in bone tissue engineering.

  12. Efficacy of Honeycomb TCP-induced Microenvironment on Bone Tissue Regeneration in Craniofacial Area.

    Science.gov (United States)

    Watanabe, Satoko; Takabatake, Kiyofumi; Tsujigiwa, Hidetsugu; Watanabe, Toshiyuki; Tokuyama, Eijiro; Ito, Satoshi; Nagatsuka, Hitoshi; Kimata, Yoshihiro

    2016-01-01

    Artificial bone materials that exhibit high biocompatibility have been developed and are being widely used for bone tissue regeneration. However, there are no biomaterials that are minimally invasive and safe. In a previous study, we succeeded in developing honeycomb β-tricalcium phosphate (β-TCP) which has through-and-through holes and is able to mimic the bone microenvironment for bone tissue regeneration. In the present study, we investigated how the difference in hole-diameter of honeycomb β-TCP (hole-diameter: 75, 300, 500, and 1600 μm) influences bone tissue regeneration histologically. Its osteoconductivity was also evaluated by implantation into zygomatic bone defects in rats. The results showed that the maximum bone formation was observed on the β-TCP with hole-diameter 300μm, included bone marrow-like tissue and the pattern of bone tissue formation similar to host bone. Therefore, the results indicated that we could control bone tissue formation by creating a bone microenvironment provided by β-TCP. Also, in zygomatic bone defect model with honeycomb β-TCP, the result showed there was osseous union and the continuity was reproduced between the both edges of resected bone and β-TCP, which indicated the zygomatic bone reproduction fully succeeded. It is thus thought that honeycomb β-TCP may serve as an excellent biomaterial for bone tissue regeneration in the head, neck and face regions, expected in clinical applications.

  13. Massive osteoradionecrosis of facial bones and soft tissues.

    Science.gov (United States)

    Benlier, E; Alicioglu, B; Kocak, Z; Yurdakul-Sikar, E; Top, H

    2009-01-01

    Osteoradionecrosis (ORN) is one of the most serious and uncommon complications in head and neck irradiation for cancer. It is defined as a combination of necrotic soft tissue and bone not being able to heal spontaneously, it demonstrates a general resistance to antibiotics and requires conservative surgical management. Even with modern radiation therapy, its incidence is highly unpredictable and varies between 4-30%. We report on a patient with a huge open cavitation in the cheek, communicating with the mouth and extending to contralateral periodontal gingival and temporal fossa. He had been treated with radiation therapy for nasopharyngeal cancer 5 years ago and presented with restriction of the opening of the mouth. Osteonecrosis complicated with osteomyelitis was evident in bilateral mandible and maxillary bones and the temporal bone. The ramus of the mandible and zygomatic arc were resected, subtotal maxillectomy was performed and the defect was repaired by a free double island flap from the scapular and parascapular osteocutaneous latissimus dorsi muscle flap supplied by subscapular artery. To our knowledge, this is the most extensive bone and soft tissue destruction due to radiation reported in the literature.

  14. Novel Scaffolds Fabricated Using Oleuropein for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Hui Fan

    2014-01-01

    Full Text Available We investigated the feasibility of oleuropein as a cross-linking agent for fabricating three-dimensional (3D porous composite scaffolds for bone tissue engineering. Human-like collagen (HLC and nanohydroxyapatite (n-HAp were used to fabricate the composite scaffold by way of cross-linking. The mechanical tests revealed superior properties for the cross-linked scaffolds compared to the uncross-linked scaffolds. The as-obtained composite scaffold had a 3D porous structure with pores ranging from 120 to 300 μm and a porosity of 73.6±2.3%. The cross-linked scaffolds were seeded with MC3T3-E1 Subclone 14 mouse osteoblasts. Fluorescence staining, the Cell Counting Kit-8 (CCK-8 assay, and scanning electron microscopy (SEM indicated that the scaffolds enhanced cell adhesion and proliferation. Our results indicate the potential of these scaffolds for bone tissue engineering.

  15. METABOLIC CHANGES OF CONNECTIVE TISSUE IN CHILDREN WITH BONE CYST

    Directory of Open Access Journals (Sweden)

    O. M. Magomedov

    2013-10-01

    Full Text Available The results of the study of diagnostically important metabolism parameters in patients with bone cysts in different stages of the disease are presented. It is shown that an increase activity of protein banding collagenase, alkaline phosphatase and also of hydroxyproline, glycosaminoglycans contents due to lower levels of calcium and inorganic phosphate levels increase in blood serum are expressed in a stage osteolysis than the step of separating. Decreasing the amount of glycosaminoglycans and collagen in bone indicates an intensification of catabolic processes in the connective tissue matrix. Diagnostically important indicators of the degree of disturbance of bone metabolism are the level of collagen, proteoglycans and activity of marker enzymes — collagenase and alkaline phosphatase. Based on the evaluation of sensitivity, specificity and diagnostic efficiency of the obtained results, we can recommend the threshold values of the investigated parameters of basic organic components and mineral metabolism of bone for the differential diagnosis of stages of bone cysts in children, which will serve as a basis for the development of appropriate diagnostic tests.

  16. Thallium-201 scintigraphy for bone and soft tissue tumors

    Energy Technology Data Exchange (ETDEWEB)

    Tokuumi, Yuji; Tsuchiya, Hiroyuki; Sunayama, Chiaki; Matsuda, Eizo; Asada, Naohiro; Taki, Junichi; Sumiya, Hisashi; Miyauchi, Tsutomu; Tomita, Katsuro [Kanazawa Univ. (Japan). School of Medicine

    1995-05-01

    This study was undertaken to assess the usefulness of thallium-201 scintigraphy in bone and soft tissue tumors. Pre-therapy scintigraphy was undertaken in a total of 136 patients with histologically confirmed diagnosis, consisting of 74 with malignant bone and soft tissue tumors, 39 with benign ones, 12 with diseases analogous to tumors, and 11 others. Thallium activity was graded on a scale of 0-4: 0=background activity, 1=equivocal activity, 2=definitive activity, but less than myocardium, 3=definite activity equal to myocardium, and 4=activity greater than myocardium. In the group of malignant tumors, thallium-201 uptake was found in 80%, although it was low for chondrosarcoma (2/8) and malignant Schwannoma (one/3). The group of benign tumors, however, showed it in only 41%, being restricted to those with giant cell tumors, chondroblastoma, fibromatosis, and osteoid osteoma. Thallium-201 uptake was also found in all 8 patients with metastatic tumors. In 23 patients undergoing thallium imaging before and after chemotherapy, scintigraphic findings revealed a high correlation with histopathological findings. Thus, thallium-201 scintigraphy may be potentially used to distinguish malignant from benign bone and soft tissue tumors, except for a few histopathological cases, as well as to determine loco-regional metastases and response to chemotherapy. (N.K.).

  17. Quality Indices Of Jaw Bone Tissue In Screening Diagnostics Of Parodontal Diseases

    Directory of Open Access Journals (Sweden)

    V.P. Konev

    2009-12-01

    Full Text Available The objective of the work is to develop and motivate screening methods of the estimation of paradontal tissues by digital X-ray study. The used methods are X-ray digital scene with estimation of bone tissue density in program Trophy 2000, clinically anatomical parallels of bone tissue density and their qualitative indices. Parallels between qualitative indices of bones of mandibular alveolar process and bone tissue density of these areas have been revealed. It is reasonable to carry out the estimation of bone tissue density indices for revealing early stages of parodontal pathology

  18. First cosmic-ray images of bone and soft tissue

    Science.gov (United States)

    Mrdja, Dusan; Bikit, Istvan; Bikit, Kristina; Slivka, Jaroslav; Hansman, Jan; Oláh, László; Varga, Dezső

    2016-11-01

    More than 120 years after Roentgen's first X-ray image, the first cosmic-ray muon images of bone and soft tissue are created. The pictures, shown in the present paper, represent the first radiographies of structures of organic origin ever recorded by cosmic rays. This result is achieved by a uniquely designed, simple and versatile cosmic-ray muon-imaging system, which consists of four plastic scintillation detectors and a muon tracker. This system does not use scattering or absorption of muons in order to deduct image information, but takes advantage of the production rate of secondaries in the target materials, detected in coincidence with muons. The 2D image slices of cow femur bone are obtained at several depths along the bone axis, together with the corresponding 3D image. Real organic soft tissue, polymethyl methacrylate and water, never seen before by any other muon imaging techniques, are also registered in the images. Thus, similar imaging systems, placed around structures of organic or inorganic origin, can be used for tomographic imaging using only the omnipresent cosmic radiation.

  19. 3D conductive nanocomposite scaffold for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Shahini A

    2013-12-01

    Full Text Available Aref Shahini,1 Mostafa Yazdimamaghani,2 Kenneth J Walker,2 Margaret A Eastman,3 Hamed Hatami-Marbini,4 Brenda J Smith,5 John L Ricci,6 Sundar V Madihally,2 Daryoosh Vashaee,1 Lobat Tayebi2,7 1School of Electrical and Computer Engineering, Helmerich Advanced Technology Research Center, 2School of Chemical Engineering, 3Department of Chemistry, 4School of Mechanical and Aerospace Engineering, 5Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, USA; 6Department of Biomaterials and Biomimetics, New York University, New York, NY; 7School of Material Science and Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, OK, USA Abstract: Bone healing can be significantly expedited by applying electrical stimuli in the injured region. Therefore, a three-dimensional (3D ceramic conductive tissue engineering scaffold for large bone defects that can locally deliver the electrical stimuli is highly desired. In the present study, 3D conductive scaffolds were prepared by employing a biocompatible conductive polymer, ie, poly(3,4-ethylenedioxythiophene poly(4-styrene sulfonate (PEDOT:PSS, in the optimized nanocomposite of gelatin and bioactive glass. For in vitro analysis, adult human mesenchymal stem cells were seeded in the scaffolds. Material characterizations using hydrogen-1 nuclear magnetic resonance, in vitro degradation, as well as thermal and mechanical analysis showed that incorporation of PEDOT:PSS increased the physiochemical stability of the composite, resulting in improved mechanical properties and biodegradation resistance. The outcomes indicate that PEDOT:PSS and polypeptide chains have close interaction, most likely by forming salt bridges between arginine side chains and sulfonate groups. The morphology of the scaffolds and cultured human mesenchymal stem cells were observed and analyzed via scanning electron microscope, micro-computed tomography, and confocal fluorescent

  20. Advances of mesenchymal stem cells derived from bone marrow and dental tissue in craniofacial tissue engineering.

    Science.gov (United States)

    Yang, Maobin; Zhang, Hongming; Gangolli, Riddhi

    2014-05-01

    Bone and dental tissues in craniofacial region work as an important aesthetic and functional unit. Reconstruction of craniofacial tissue defects is highly expected to ensure patients to maintain good quality of life. Tissue engineering and regenerative medicine have been developed in the last two decades, and been advanced with the stem cell technology. Bone marrow derived mesenchymal stem cells are one of the most extensively studied post-natal stem cell population, and are widely utilized in cell-based therapy. Dental tissue derived mesenchymal stem cells are a relatively new stem cell population that isolated from various dental tissues. These cells can undergo multilineage differentiation including osteogenic and odontogenic differentiation, thus provide an alternative source of mesenchymal stem cells for tissue engineering. In this review, we discuss the important issues in mesenchymal stem cell biology including the origin and functions of mesenchymal stem cells, compare the properties of these two types of mesenchymal cells, update recent basic research and clinic applications in this field, and address important future challenges.

  1. Fabrication of Bioceramic Bone Scaffolds for Tissue Engineering

    Science.gov (United States)

    Liu, Fwu-Hsing

    2014-10-01

    In this study, microhydroxyapatite and nanosilica sol were used as the raw materials for fabrication of bioceramic bone scaffold using selective laser sintering technology in a self-developed 3D Printing apparatus. When the fluidity of ceramic slurry is matched with suitable laser processing parameters, a controlled pore size of porous bone scaffold can be fabricated under a lower laser energy. Results shown that the fabricated scaffolds have a bending strength of 14.1 MPa, a compressive strength of 24 MPa, a surface roughness of 725 nm, a pore size of 750 μm, an apparent porosity of 32%, and a optical density of 1.8. Results indicate that the mechanical strength of the scaffold can be improved after heat treatment at 1200 °C for 2 h, while simultaneously increasing surface roughness conducive to osteoprogenitor cell adhesion. MTT method and SEM observations confirmed that bone scaffolds fabricated under the optimal manufacturing process possess suitable biocompatibility and mechanical properties, allowing smooth adhesion and proliferation of osteoblast-like cells. Therefore, they have great potential for development in the field of tissue engineering.

  2. Chitosan-Alginate Biocomposite Containing Fucoidan for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Jayachandran Venkatesan

    2014-01-01

    Full Text Available Over the last few years, significant research has been conducted in the construction of artificial bone scaffolds. In the present study, different types of polymer scaffolds, such as chitosan-alginate (Chi-Alg and chitosan-alginate with fucoidan (Chi-Alg-fucoidan, were developed by a freeze-drying method, and each was characterized as a bone graft substitute. The porosity, water uptake and retention ability of the prepared scaffolds showed similar efficacy. The pore size of the Chi-Alg and Chi-Alg-fucoidan scaffolds were measured from scanning electron microscopy and found to be 62–490 and 56–437 µm, respectively. In vitro studies using the MG-63 cell line revealed profound cytocompatibility, increased cell proliferation and enhanced alkaline phosphatase secretion in the Chi-Alg-fucoidan scaffold compared to the Chi-Alg scaffold. Further, protein adsorption and mineralization were about two times greater in the Chi-Alg-fucoidan scaffold than the Chi-Alg scaffold. Hence, we suggest that Chi-Alg-fucoidan will be a promising biomaterial for bone tissue regeneration.

  3. Osteocalcin/fibronectin-functionalized collagen matrices for bone tissue engineering.

    Science.gov (United States)

    Kim, S G; Lee, D S; Lee, S; Jang, J-H

    2015-06-01

    Collagen is the most abundant protein found in the extracellular matrix and is widely used to build scaffolds for biomedical applications which are the result of its biocompatibility and biodegradability. In the present study, we constructed a rhOCN/FNIII9-10 fusion protein and rhOCN/FNIII9-10-functionalized collagen matrices and investigated the potential value for bone tissue engineering. In vitro studies carried out with preosteoblastic MC3T3-E1 cells showed that rhOCN/FNIII9-10 fusion protein promoted cell adhesion and the mRNA levels of osteogenic markers including osteocalcin, runt-related transcription factor 2, alkaline phosphatase (ALP), and collagen type I. In addition, rhOCN/FNIII9-10-functionalized collagen matrices showed significant induction of the ALP activity more than rhFNIII9-10-functionalized collagen matrices or collagen matrices alone. These results suggested that rhOCN/FNIII9-10-functionalized collagen matrices have potential for bone tissue engineering.

  4. Organotypic culture of human bone marrow adipose tissue.

    Science.gov (United States)

    Uchihashi, Kazuyoshi; Aoki, Shigehisa; Shigematsu, Masamori; Kamochi, Noriyuki; Sonoda, Emiko; Soejima, Hidenobu; Fukudome, Kenji; Sugihara, Hajime; Hotokebuchi, Takao; Toda, Shuji

    2010-04-01

    The precise role of bone marrow adipose tissue (BMAT) in the marrow remains unknown. The purpose of the present study was therefore to describe a novel method for studying BMAT using 3-D collagen gel culture of BMAT fragments, immunohistochemistry, ELISA and real-time reverse transcription-polymerase chain reaction. Mature adipocytes and CD45+ leukocytes were retained for >3 weeks. Bone marrow stromal cells (BMSC) including a small number of lipid-laden preadipocytes and CD44+/CD105+ mesenchymal stem cell (MSC)-like cells, developed from BMAT. Dexamethasone (10 micromol/L), but not insulin (20 mU/mL), significantly increased the number of preadipocytes. Dexamethasone and insulin also promoted leptin production and gene expression in BMAT. Adiponectin production by BMAT was BMAT, in which adiponectin protein secretion is normally very low, and that BMAT may exhibit a different phenotype from that of the visceral and subcutaneous adipose tissues. BMAT-osteoblast interactions were also examined, and it was found that osteoblasts inhibited the development of BMSC and reduced leptin production, while BMAT inhibited the growth and differentiation of osteoblasts. The present novel method proved to be useful for the study of BMAT biology.

  5. Peculiarities of the bone tissue resorption under microgravity conditions

    Science.gov (United States)

    Rodionova, N.; Oganov, V.; Polkovenko, O.; Nitsevich, T.

    The actual problem - peculiarities of resorptive processes in the spongiose of thingbones - we studied with the use of tranmissive electron microscopy in experiments on rats (American space station SLS-2) and on monkeys Macaca mulatt? (BION-11). Animals were onboard during 2 weeks. There was established, that the resorption happen with osteoclasts participation. They can create groups of cells. In the osteoclasts population we indicated not typical for the control (ground experiment) "giant" cells, which have on ultrathin sections 5-6 nuclei, many lysosomes, well developed "light" zone and "brush-border". The destruction of minera lized matrix in bone lacunas also happens by the way of osteolytic activity of osteocytes. Lysosome ferments of osteocytes are secreted by the eczocytosis. The osteocytic osteolysis, as well as the osteoclastic one can be seen as a physiological, gormon-dependent mechanism of resorption. The presence of a considerable number of neutrophiles, which enter in some zones of resorption is also typical. When these neutrophiles destruct, they release lysosomic ferments that dissolve the bone matrix. In some zones of resorption we noted the presence of the row from collagen fibrils, which loosed crystals , on mineralized matrix borders. The cell detritus is noted in zones of surface dissolving among crystallic conglomerates. It certificates the processes of osteogenic cells destruction that happen here. So, under the microgravity conditions in zones of adaptive remodeling of the spongiose the processes of the bone tissue resorption happen by some ways, namely: by the functional activization of osteoclasts; by the osteocytic osteolysis increasing; as a result of hydrolytic activity of neutrophiles, entering in these zones, and also by the local demineralization and further destruction of bone matrix surface zones.

  6. Comparative study on seeding methods of human bone marrow stromal cells in bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    齐欣; 刘建国; 常颖; 徐莘香

    2004-01-01

    Background In general the traditional static seeding method has its limitation while the dynamic seeding method reveals its advantages over traditional static method. We compared static and dynamic seeding method for human bone marrow stromal cells (hBMSCs) in bone tissue engineering.Methods DNA assay was used for detecting the maximal initial seeding concentration for static seeding. Dynamic and static seeding methods were compared, when scaffolds were loaded with hBMSCs at this maximal initial cell seeding concentration. Histology and scanning electron microscope (SEM) were examined to evaluate the distribution of cells inside the constructs. Markers encoding osteogenic genes were measured by fluorescent RT-PCR. The protocol for dynamic seeding of hBMSCs was also investigated.Results DNA assay showed that the static maximal initial seeding concentration was lower than that in dynamic seeding. Histology and SEM showed even distribution and spread of cells in the dynamically seeded constructs, while their statically seeded counterparts showed cell aggregation.Fluorescent RT-PCR again showed stronger osteogenic potential of dynamically seeded constructs.Conclusion dynamic seeding of hBMSCs is a promising technique in bone tissue engineering.

  7. Calcium Phosphate Scaffolds Combined with Bone Morphogenetic Proteins or Mesenchymal Stem Cells in Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Han Sun

    2015-01-01

    Full Text Available Objective: The purpose of this study was to review the current status of calcium phosphate (CaP scaffolds combined with bone morphogenetic proteins (BMPs or mesenchymal stem cells (MSCs in the field of bone tissue engineering (BTE. Date Sources: Data cited in this review were obtained primarily from PubMed and Medline in publications from 1979 to 2014, with highly regarded older publications also included. The terms BTE, CaP, BMPs, and MSC were used for the literature search. Study Selection: Reviews focused on relevant aspects and original articles reporting in vitro and/or in vivo results concerning the efficiency of CaP/BMPs or CaP/MSCs composites were retrieved, reviewed, analyzed, and summarized. Results: An ideal BTE product contains three elements: Scaffold, growth factors, and stem cells. CaP-based scaffolds are popular because of their outstanding biocompatibility, bioactivity, and osteoconductivity. However, they lack stiffness and osteoinductivity. To solve this problem, composite scaffolds of CaP with BMPs have been developed. New bone formation by CaP/BMP composites can reach levels similar to those of autografts. CaP scaffolds are compatible with MSCs and CaP/MSC composites exhibit excellent osteogenesis and stiffness. In addition, a CaP/MSC/BMP scaffold can repair bone defects more effectively than an autograft. Conclusions: Novel BTE products possess remarkable osteoconduction and osteoinduction capacities, and exhibit balanced degradation with osteogenesis. Further work should yield safe, viable, and efficient materials for the repair of bone lesions.

  8. Calcium Phosphate Scaffolds Combined with Bone Morphogenetic Proteins or Mesenchymal Stem Cells in Bone Tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    Han Sun; Hui-Lin Yang

    2015-01-01

    Objective:The purpose of this study was to review the current status of calcium phosphate (CaP) scaffolds combined with bone morphogenetic proteins (BMPs) or mesenchymal stem cells (MSCs) in the field of bone tissue engineering (BTE).Date Sources:Data cited in this review were obtained primarily from PubMed and Medline in publications from 1979 to 2014,with highly regarded older publications also included.The terms BTE,CaP,BMPs,and MSC were used for the literature search.Study Selection:Reviews focused on relevant aspects and original articles reporting in vitro and/or in vivo results concerning the efficiency of CaP/BMPs or CaP/MSCs composites were retrieved,reviewed,analyzed,and summarized.Results:An ideal BTE product contains three elements:Scaffold,growth factors,and stem cells.CaP-based scaffolds are popular because of their outstanding biocompatibility,bioactivity,and osteoconductivity.However,they lack stiffness and osteoinductivity.To solve this problem,composite scaffolds of CaP with BMPs have been developed.New bone formation by CaP/BMP composites can reach levels similar to those of autografts.CaP scaffolds are compatible with MSCs and CaP/MSC composites exhibit excellent osteogenesis and stiffness.In addition,a CaP/MSC/BMP scaffold can repair bone defects more effectively than an autograft.Conclusions:Novel BTE products possess remarkable osteoconduction and osteoinduction capacities,and exhibit balanced degradation with osteogenesis.Further work should yield safe,viable,and efficient materials for the repair of bone lesions.

  9. Primary Hyperparathyroidism: The Influence of Bone Marrow Adipose Tissue on Bone Loss and of Osteocalcin on Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Maira L. Mendonça

    Full Text Available OBJECTIVES: Bone marrow adipose tissue has been associated with low bone mineral density. However, no data exist regarding marrow adipose tissue in primary hyperparathyroidism, a disorder associated with bone loss in conditions of high bone turnover. The objective of the present study was to investigate the relationship between marrow adipose tissue, bone mass and parathyroid hormone. The influence of osteocalcin on the homeostasis model assessment of insulin resistance was also evaluated. METHODS: This was a cross-sectional study conducted at a university hospital, involving 18 patients with primary hyperparathyroidism (PHPT and 21 controls (CG. Bone mass was assessed by dual-energy x-ray absorptiometry and marrow adipose tissue was assessed by 1H magnetic resonance spectroscopy. The biochemical evaluation included the determination of parathyroid hormone, osteocalcin, glucose and insulin levels. RESULTS: A negative association was found between the bone mass at the 1/3 radius and parathyroid hormone levels (r = -0.69; p<0.01. Marrow adipose tissue was not significantly increased in patients (CG = 32.8±11.2% vs PHPT = 38.6±12%. The serum levels of osteocalcin were higher in patients (CG = 8.6±3.6 ng/mL vs PHPT = 36.5±38.4 ng/mL; p<0.005, but no associations were observed between osteocalcin and insulin or between insulin and both marrow adipose tissue and bone mass. CONCLUSION: These results suggest that the increment of adipogenesis in the bone marrow microenvironment under conditions of high bone turnover due to primary hyperparathyroidism is limited. Despite the increased serum levels of osteocalcin due to primary hyperparathyroidism, these patients tend to have impaired insulin sensitivity.

  10. Rapid prototyping for tissue-engineered bone scaffold by 3D printing and biocompatibility study.

    Science.gov (United States)

    He, Hui-Yu; Zhang, Jia-Yu; Mi, Xue; Hu, Yang; Gu, Xiao-Yu

    2015-01-01

    The prototyping of tissue-engineered bone scaffold (calcined goat spongy bone-biphasic ceramic composite/PVA gel) by 3D printing was performed, and the biocompatibility of the fabricated bone scaffold was studied. Pre-designed STL file was imported into the GXYZ303010-XYLE 3D printing system, and the tissue-engineered bone scaffold was fabricated by 3D printing using gel extrusion. Rabbit bone marrow stromal cells (BMSCs) were cultured in vitro and then inoculated to the sterilized bone scaffold obtained by 3D printing. The growth of rabbit BMSCs on the bone scaffold was observed under the scanning electron microscope (SEM). The effect of the tissue-engineered bone scaffold on the proliferation and differentiation of rabbit BMSCs using MTT assay. Universal testing machine was adopted to test the tensile strength of the bone scaffold. The leachate of the bone scaffold was prepared and injected into the New Zealand rabbits. Cytotoxicity test, acute toxicity test, pyrogenic test and intracutaneous stimulation test were performed to assess the biocompatibility of the bone scaffold. Bone scaffold manufactured by 3D printing had uniform pore size with the porosity of about 68.3%. The pores were well interconnected, and the bone scaffold showed excellent mechanical property. Rabbit BMSCs grew and proliferated on the surface of the bone scaffold after adherence. MTT assay indicated that the proliferation and differentiation of rabbit BMSCs on the bone scaffold did not differ significantly from that of the cells in the control. In vivo experiments proved that the bone scaffold fabricated by 3D printing had no acute toxicity, pyrogenic reaction or stimulation. Bone scaffold manufactured by 3D printing allows the rabbit BMSCs to adhere, grow and proliferate and exhibits excellent biomechanical property and high biocompatibility. 3D printing has a good application prospect in the prototyping of tissue-engineered bone scaffold.

  11. Bone and soft tissue tumors of hip and pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Bloem, Johan L., E-mail: j.l.bloem@lumc.nl [Leiden University Medical Center, Department of Radiology, PO Box 9600, 2300 RC Leiden (Netherlands); Reidsma, Inge I., E-mail: i.i.reidsma@lumc.nl [Leiden University Medical Center, Department of Radiology, PO Box 9600, 2300 RC Leiden (Netherlands)

    2012-12-15

    Objective is to identify epidemiologic and radiologic criteria allowing specific diagnoses of tumors and tumor-like lesions in the hip region and pelvis, and to optimize pre-operative staging. Patients with pelvic tumors are usually older, and their tumors are larger relative to patients with tumors in extremities. The majority of tumors in the pelvis are malignant (metastases, myeloma, chondrosarcoma, Ewing-, osteo-, and MFH/fibrosarcoma), while those in the proximal femur are in majority benign (fibrous dysplasia, solitary bone cyst, and osteoid osteoma). Soft tissue masses in the thigh in the elderly are typically sarcomas without tumor specific signs. Common tumor-like lesions occurring in the hip and pelvis that can mimic neoplasm are: infections (including tuberculosis), insufficiency/avulsion fractures, cysts, fibrous dysplasia, aneurysmal bone cyst, Langerhans cell histiocytosis, and Paget's disease. Local MR staging is based on the compartmental anatomy. The psoas and gluteal muscles are easily invaded by sarcoma originating in the ileum. The pectineus muscle protects the neurovascular bundle at the level of the hip. The thigh is separated into three compartments, some structures (Sartorius muscle) cross borders between compartments. Immobile joints (SI-joints, osteoarthritic hip) are relatively easily crossed by sarcoma and giant cell tumor.

  12. Single walled carbon nanotube composites for bone tissue engineering.

    Science.gov (United States)

    Gupta, Ashim; Woods, Mia D; Illingworth, Kenneth David; Niemeier, Ryan; Schafer, Isaac; Cady, Craig; Filip, Peter; El-Amin, Saadiq F

    2013-09-01

    The purpose of this study was to develop single walled carbon nanotubes (SWCNT) and poly lactic-co-glycolic acid (PLAGA) composites for orthopedic applications and to evaluate the interaction of human stem cells (hBMSCs) and osteoblasts (MC3T3-E1 cells) via cell growth, proliferation, gene expression, extracellular matrix production and mineralization. PLAGA and SWCNT/PLAGA composites were fabricated with various amounts of SWCNT (5, 10, 20, 40, and 100 mg), characterized and degradation studies were performed. Cells were seeded and cell adhesion/morphology, growth/survival, proliferation and gene expression analysis were performed to evaluate biocompatibility. Imaging studies demonstrated uniform incorporation of SWCNT into the PLAGA matrix and addition of SWCNT did not affect the degradation rate. Imaging studies revealed that MC3T3-E1 and hBMSCs cells exhibited normal, non-stressed morphology on the composites and all were biocompatible. Composites with 10 mg SWCNT resulted in highest rate of cell proliferation (p composites. Gene expression of alkaline phosphatase, collagen I, osteocalcin, osteopontin, Runx-2, and Bone Sialoprotein was observed on all composites. In conclusion, SWCNT/PLAGA composites imparted beneficial cellular growth capabilities and gene expression, and mineralization abilities were well established. These results demonstrate the potential of SWCNT/PLAGA composites for musculoskeletal regeneration and bone tissue engineering (BTE) and are promising for orthopedic applications.

  13. Cobalt doped proangiogenic hydroxyapatite for bone tissue engineering application.

    Science.gov (United States)

    Kulanthaivel, Senthilguru; Roy, Bibhas; Agarwal, Tarun; Giri, Supratim; Pramanik, Krishna; Pal, Kunal; Ray, Sirsendu S; Maiti, Tapas K; Banerjee, Indranil

    2016-01-01

    The present study delineates the synthesis and characterization of cobalt doped proangiogenic-osteogenic hydroxyapatite. Hydroxyapatite samples, doped with varying concentrations of bivalent cobalt (Co(2+)) were prepared by the ammoniacal precipitation method and the extent of doping was measured by ICP-OES. The crystalline structure of the doped hydroxyapatite samples was confirmed by XRD and FTIR studies. Analysis pertaining to the effect of doped hydroxyapatite on cell cycle progression and proliferation of MG-63 cells revealed that the doping of cobalt supported the cell viability and proliferation up to a threshold limit. Furthermore, such level of doping also induced differentiation of the bone cells, which was evident from the higher expression of differentiation markers (Runx2 and Osterix) and better nodule formation (SEM study). Western blot analysis in conjugation with ELISA study confirmed that the doped HAp samples significantly increased the expression of HIF-1α and VEGF in MG-63 cells. The analysis described here confirms the proangiogenic-osteogenic properties of the cobalt doped hydroxyapatite and indicates its potential application in bone tissue engineering.

  14. Meshless methods in biomechanics bone tissue remodelling analysis

    CERN Document Server

    Belinha, Jorge

    2014-01-01

    This book presents the complete formulation of a new advanced discretization meshless technique: the Natural Neighbour Radial Point Interpolation Method (NNRPIM). In addition, two of the most popular meshless methods, the EFGM and the RPIM, are fully presented. Being a truly meshless method, the major advantages of the NNRPIM over the FEM, and other meshless methods, are the remeshing flexibility and the higher accuracy of the obtained variable field. Using the natural neighbour concept, the NNRPIM permits to determine organically the influence-domain, resembling the cellulae natural behaviour. This innovation permits the analysis of convex boundaries and extremely irregular meshes, which is an advantage in the biomechanical analysis, with no extra computational effort associated.   This volume shows how to extend the NNRPIM to the bone tissue remodelling analysis, expecting to contribute with new numerical tools and strategies in order to permit a more efficient numerical biomechanical analysis.

  15. Bisphosphonate-adsorbed ceramic nanoparticles increase bone formation in an injectable carrier for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Tegan L Cheng

    2015-10-01

    Full Text Available Sucrose acetate isobutyrate (SAIB is a sugar-based carrier. We have previously applied SAIB as a minimally invasive system for the co-delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2 and found synergy when co-delivering zoledronic acid (ZA and hydroxyapatite (HA nanoparticles. Alternative bioceramics were investigated in a murine SAIB/rhBMP-2 injection model. Neither beta-tricalcium phosphate (TCP nor Bioglass (BG 45S5 had a significant effect on bone volume (BV alone or in combination with the ZA. 14C-labelled ZA binding assays showed particle size and ceramic composition affected binding with nano-HA > micro-HA > TCP > BG. Micro-HA and nano-HA increased BV in a rat model of rhBMP-2/SAIB injection (+278% and +337%, and BV was further increased with ZA–adsorbed micro-HA and nano-HA (+530% and +889%. These data support the use of ZA–adsorbed nanoparticle-sized HA as an optimal additive for the SAIB/rhBMP-2 injectable system for bone tissue engineering.

  16. An update on the Application of Nanotechnology in Bone Tissue Engineering

    Science.gov (United States)

    Griffin, MF; Kalaskar, DM; Seifalian, A.; Butler, PE

    2016-01-01

    Background: Natural bone is a complex and hierarchical structure. Bone possesses an extracellular matrix that has a precise nano-sized environment to encourage osteoblasts to lay down bone by directing them through physical and chemical cues. For bone tissue regeneration, it is crucial for the scaffolds to mimic the native bone structure. Nanomaterials, with features on the nanoscale have shown the ability to provide the appropriate matrix environment to guide cell adhesion, migration and differentiation. Methods: This review summarises the new developments in bone tissue engineering using nanobiomaterials. The design and selection of fabrication methods and biomaterial types for bone tissue engineering will be reviewed. The interactions of cells with different nanostructured scaffolds will be discussed including nanocomposites, nanofibres and nanoparticles. Results: Several composite nanomaterials have been able to mimic the architecture of natural bone. Bioceramics biomaterials have shown to be very useful biomaterials for bone tissue engineering as they have osteoconductive and osteoinductive properties. Nanofibrous scaffolds have the ability to provide the appropriate matrix environment as they can mimic the extracellular matrix structure of bone. Nanoparticles have been used to deliver bioactive molecules and label and track stem cells. Conclusion: Future studies to improve the application of nanomaterials for bone tissue engineering are needed. PMID:28217209

  17. Routine bone scintigraphy in primary staging of soft tissue sarcoma - Is it worthwhile?

    NARCIS (Netherlands)

    Jager, PL; Hoekstra, HJ; Leeuw, JA; van der Graaf, WTA; de Vries, EGE; Piers, DA

    2000-01-01

    BACKGROUND. The incidence of bone metastases in soft tissue sarcoma (STS) patients seems to be low but has not been studied separately. In this study, the authors aimed to determine the value of routine radionuclide bone scanning in preoperative staging of STS patients. METHODS. Preoperative bone sc

  18. Graphene and its nanostructure derivatives for use in bone tissue engineering: Recent advances.

    Science.gov (United States)

    Shadjou, Nasrin; Hasanzadeh, Mohammad

    2016-05-01

    Tissue engineering and regenerative medicine represent areas of increasing interest because of the major progress in cell and organ transplantation, as well as advances in materials science and engineering. Tissue-engineered bone constructs have the potential to alleviate the demand arising from the shortage of suitable autograft and allograft materials for augmenting bone healing. Graphene and its derivatives have attracted much interest for applications in bone tissue engineering. For this purpose, this review focuses on more recent advances in tissue engineering based on graphene-biomaterials from 2013 to May 2015. The purpose of this article was to give a general description of studies of nanostructured graphene derivatives for bone tissue engineering. In this review, we highlight how graphene family nanomaterials are being exploited for bone tissue engineering. Firstly, the main requirements for bone tissue engineering were discussed. Then, the mechanism by which graphene based materials promote new bone formation was explained, following which the current research status of main types of nanostructured scaffolds for bone tissue engineering was reviewed and discussed. In addition, graphene-based bioactive glass, as a potential drug/growth factor carrier, was reviewed which includes the composition-structure-drug delivery relationship and the functional effect on the tissue-stimulation properties. Also, the effect of structural and textural properties of graphene based materials on development of new biomaterials for production of bone implants and bone cements were discussed. Finally, the present review intends to provide the reader an overview of the current state of the graphene based biomaterials in bone tissue engineering, its limitations and hopes as well as the future research trends for this exciting field of science.

  19. Computational model-informed design and bioprinting of cell-patterned constructs for bone tissue engineering.

    Science.gov (United States)

    Carlier, Aurélie; Skvortsov, Gözde Akdeniz; Hafezi, Forough; Ferraris, Eleonora; Patterson, Jennifer; Koç, Bahattin; Van Oosterwyck, Hans

    2016-05-17

    Three-dimensional (3D) bioprinting is a rapidly advancing tissue engineering technology that holds great promise for the regeneration of several tissues, including bone. However, to generate a successful 3D bone tissue engineering construct, additional complexities should be taken into account such as nutrient and oxygen delivery, which is often insufficient after implantation in large bone defects. We propose that a well-designed tissue engineering construct, that is, an implant with a specific spatial pattern of cells in a matrix, will improve the healing outcome. By using a computational model of bone regeneration we show that particular cell patterns in tissue engineering constructs are able to enhance bone regeneration compared to uniform ones. We successfully bioprinted one of the most promising cell-gradient patterns by using cell-laden hydrogels with varying cell densities and observed a high cell viability for three days following the bioprinting process. In summary, we present a novel strategy for the biofabrication of bone tissue engineering constructs by designing cell-gradient patterns based on a computational model of bone regeneration, and successfully bioprinting the chosen design. This integrated approach may increase the success rate of implanted tissue engineering constructs for critical size bone defects and also can find a wider application in the biofabrication of other types of tissue engineering constructs.

  20. Biomineralization of a Self-Assembled Extracellular Matrix for Bone Tissue Engineering

    OpenAIRE

    Meng, Yizhi; Qin, Yi-Xian; DiMasi, Elaine; Ba, Xiaolan; Rafailovich, Miriam; Pernodet, Nadine

    2008-01-01

    Understanding how biomineralization occurs in the extracellular matrix (ECM) of bone cells is crucial to the understanding of bone formation and the development of a successfully engineered bone tissue scaffold. It is still unclear how ECM mechanical properties affect protein-mineral interactions in early stages of bone mineralization. We investigated the longitudinal mineralization properties of MC3T3-E1 cells and the elastic modulus of their ECM using shear modulation force microscopy, sync...

  1. Electrospun Hydroxyapatite-Containing Chitosan Nanofibers Crosslinked with Genipin for Bone Tissue Engineering

    OpenAIRE

    Frohbergh, Michael E.; Katsman, Anna; Botta, Gregory P.; Lazarovici, Phillip; Schauer, Caroline L.; Wegst, Ulrike G.K.; Lelkes, Peter I

    2012-01-01

    Reconstruction of large bone defects remains problematic in orthopedic and craniofacial clinical practice. Autografts are limited in supply and are associated with donor site morbidity while other materials show poor integration with the host’s own bone. This lack of integration is often due to the absence of periosteum, the outer layer of bone that contains osteoprogenitor cells and is critical for the growth and remodeling of bone tissue. In this study we developed a one-step platform to el...

  2. Biomimetic coatings for bone tissue engineering of critical-sized defects

    OpenAIRE

    2010-01-01

    The repair of critical-sized bone defects is still challenging in the fields of implantology, maxillofacial surgery and orthopaedics. Current therapies such as autografts and allografts are associated with various limitations. Cytokine-based bone tissue engineering has been attracting increasing attention. Bone-inducing agents have been locally injected to stimulate the native bone-formation activity, but without much success. The reason is that these drugs must be delivered slowly and at a l...

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

    Science.gov (United States)

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

    2013-04-01

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

  4. 3D Tissue Scaffold Printing On Custom Artificial Bone Applications

    OpenAIRE

    Betül ALDEMİR; DİKİCİ, Serkan; ÖZTÜRK, Şükrü; KAHRAMAN, Ozan; Aylin ŞENDEMİR ÜRKMEZ; Oflaz, Hakan, 1980-

    2015-01-01

    Production of defect-matching scaffolds is the most critical step in custom artificial bone applications. Three dimensional printing (3DP) is one of the best techniques particularly for custom designs on artificial bone applications because of the high controllability and design independency. Our long-term aim is to implant an artificial custom bone that is cultured with patient's own mesenchymal stem cells after determining defect architecture on patient's bone by using CT-scan and printing ...

  5. Preparation and characterization of bionic bone structure chitosan/hydroxyapatite scaffold for bone tissue engineering.

    Science.gov (United States)

    Zhang, Jiazhen; Nie, Jingyi; Zhang, Qirong; Li, Youliang; Wang, Zhengke; Hu, Qiaoling

    2014-01-01

    Three-dimensional oriented chitosan (CS)/hydroxyapatite (HA) scaffolds were prepared via in situ precipitation method in this research. Scanning electron microscopy (SEM) images indicated that the scaffolds with acicular nano-HA had the spoke-like, multilayer and porous structure. The SEM of osteoblasts which were polygonal or spindle-shaped on the composite scaffolds after seven-day cell culture showed that the cells grew, adhered, and spread well. The results of X-ray powder diffractometer and Fourier transform infrared spectrometer showed that the mineral particles deposited in the scaffold had phase structure similar to natural bone and confirmed that particles were exactly HA. In vitro biocompatibility evaluation indicated the composite scaffolds showed a higher degree of proliferation of MC3T3-E1 cell compared with the pure CS scaffolds and the CS/HA10 scaffold was the highest one. The CS/HA scaffold also had a higher ratio of adhesion and alkaline phosphate activity value of osteoblasts compared with the pure CS scaffold, and the ratio increased with the increase of HA content. The ALP activity value of composite scaffolds was at least six times of the pure CS scaffolds. The results suggested that the composite scaffolds possessed good biocompatibility. The compressive strength of CS/HA15 increased by 33.07% compared with the pure CS scaffold. This novel porous scaffold with three-dimensional oriented structure might have a potential application in bone tissue engineering.

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

    OpenAIRE

    2014-01-01

    Tissue engineering–based bone grafts are emerging as a viable alternative treatment modality to repair and regenerate tissues damaged as a result of disease or injury. The choice of the biomaterial component is a critical determinant of the success of the graft or scaffold; essentially, it must induce and allow native tissue integration, and most importantly mimic the hierarchical structure of the native bone. Calcium ...

  7. Smart scaffolds in bone tissue engineering: A systematicreview of literature

    Institute of Scientific and Technical Information of China (English)

    Saeed Reza Motamedian; Sepanta Hosseinpour; Mitra Ghazizadeh Ahsaie; Arash Khojasteh

    2015-01-01

    AIM To improve osteogenic differentiation and attachmentof cells.METHODS: An electronic search was conducted inPubMed from January 2004 to December 2013. Studieswhich performed smart modifications on conventionalbone scaffold materials were included. Scaffoldswith controlled release or encapsulation of bioactivemolecules were not included. Experiments which did notinvestigate response of cells toward the scaffold (cellattachment, proliferation or osteoblastic differentiation)were excluded.RESULTS: Among 1458 studies, 38 met the inclusion andexclusion criteria. The main scaffold varied extensivelyamong the included studies. Smart modificationsincluded addition of growth factors (group Ⅰ-11 studies),extracellular matrix-like molecules (group Ⅱ-13 studies)and nanoparticles (nano-HA) (group Ⅲ-17 studies). In allgroups, surface coating was the most commonly appliedapproach for smart modification of scaffolds. In group I,bone morphogenetic proteins were mainly used as growthfactor stabilized on polycaprolactone (PCL). In groupⅡ, collagen 1 in combination with PCL, hydroxyapatite(HA) and tricalcium phosphate were the most frequentscaffolds used. In the third group, nano-HA with PCL andchitosan were used the most. As variable methods wereused, a thorough and comprehensible compare betweenthe results and approaches was unattainable.CONCLUSION: Regarding the variability in methodologyof these in vitro studies it was demonstrated that smartmodification of scaffolds can improve tissue properties.

  8. Ovalbumin-BasedPorous Scaffolds for Bone Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Gabrielle Farrar

    2010-01-01

    Full Text Available Cell differentiation on glutaraldehyde cross-linked ovalbumin scaffolds was the main focus of this research. Salt leaching and freeze drying were used to create a three-dimensional porous structure. Average pore size was 147.84±40.36 μm and 111.79±30.71 μm for surface and cross sectional area, respectively. Wet compressive strength and elastic modulus were 6.8±3.6 kPa. Average glass transition temperature was 320.1±1.4°C. Scaffolds were sterilized with ethylene oxide prior to seeding MC3T3-E1 cells. Cells were stained with DAPI and Texas red to determine morphology and proliferation. Average cell numbers increased between 4-hour- and 96-hour-cultured scaffolds. Alkaline phosphatase and osteocalcin levels were measured at 3, 7, 14, and 21 days. Differentiation studies showed an increase in osteocalcin at 21 days and alkaline phosphatase levels at 14 days, both indicating differentiation occurred. This work demonstrated the use of ovalbumin scaffolds for a bone tissue engineering application.

  9. Fabrication of polylactide nanocomposite scaffolds for bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Mkhabela, Vuyiswa J.; Ray, Suprakas Sinha [Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028 (South Africa); DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa)

    2015-05-22

    Highly porous three-dimensional polylactide (PLA) scaffolds were obtained from PLA incorporated with different amounts of chitosan-modified montmorillonite (CS-MMT), through solvent casting and particulate leaching method. The processed scaffolds were tested in vitro for their possible application in bone tissue engineering. Scaffolds were characterized by Focused Ion Beam Scanning Electron Microscopy (FIB SEM), Fourier Transform Infra-Red (FTIR), and X-Ray Diffraction (XRD) to study their structure and intermolecular interactions. Bioresorbability tests in simulated body fluid (pH 7.4) were conducted to assess the response of the scaffolds in a simulated physiological condition. The FIB SEM images of the scaffolds showed a porous architecture with gradual change in morphology with increasing CS-MMT concentration. FTIR analysis revealed the presence of both PLA and CS-MMT particles on the surface of the scaffolds. XRD showed that the crystalline unit cell type was the same for all the scaffolds, and crystallinity decreased with an increase in CS-MMT concentration. The scaffolds were found to be bioresorbable, with rapid bioresorbability on the scaffolds with a high CS-MMT concentration.

  10. Aligned and random nanofibrous nanocomposite scaffolds for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Amir Doustgani

    2013-01-01

    Full Text Available Abstract  Aligned and random nanocomposite nanofibrous scaffolds were electrospun from polycaprolactone (PCL, poly (vinyl alcohol (PVA and hydroxyapatite nanoparticles (nHA. The morphology and mechanical characteristics of the nanofibers were evaluated using scanning electron microscopy and tensile testing, respectively. Scanning electron microscopy revealed fibers with an average diameter of 123 ± 32 nm and 339 ± 107 nm for aligned and random nanofibers, respectively. The mechanical data indicated the higher tensile strength and elastic modulus of aligned nanofibers. The in vitro biocompatibility of aligned and random nanofibrous scaffolds was also assessed by growing mesenchymal stem cells (MSCs, and investigating the proliferation and alkaline phosphatase activity (ALP on different nanofibrous scaffolds. Our  findings  showed  that  the  alignment  orientation  of  nanofibers  enhanced  the osteogenic differentiation of stem cells. The in vitro results showed that the aligned biocomposite nanofibrous scaffolds of PCL/nHA/PVA could be a potential substrate for tissue engineering applications, especially in the field of artificial bone implant.

  11. Preparation of hybrid biomaterials for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Vilma Conceição Costa

    2007-03-01

    Full Text Available Tissue engineering has evolved from the use of biomaterials for bone substitution that fulfill the clinical demands of biocompatibility, biodegradability, non-immunogeneity, structural strength and porosity. Porous scaffolds have been developed in many forms and materials, but few reached the need of adequate physical, biological and mechanical properties. In the present paper we report the preparation of hybrid porous polyvinyl alcohol (PVA/bioactive glass through the sol-gel route, using partially and fully hydrolyzed polyvinyl alcohol, and perform structural characterization. Hybrids containing PVA and bioactive glass with composition 58SiO2-33CaO-9P2O5 were synthesized by foaming a mixture of polymer solution and bioactive glass sol-gel precursor solution. Sol-gel solution was prepared from mixing tetraethoxysilane (TEOS, triethylphosphate (TEP, and calcium chloride as chemical precursors. The hybrid composites obtained after aging and drying at low temperature were chemically and morphologically characterized through infrared spectroscopy and scanning electron microscopy. The degree of hydrolysis of PVA, concentration of PVA solution and different PVA-bioglass composition ratios affect the synthesis procedure. Synthesis parameters must be very well combined in order to allow foaming and gelation. The hybrid scaffolds obtained exhibited macroporous structure with pore size varying from 50 to 600 µm.

  12. Impact of dental implant insertion method on the peri-implant bone tissue: Experimental study

    Directory of Open Access Journals (Sweden)

    Stamatović Novak

    2013-01-01

    Full Text Available Background/Aim. The function of dental implants depends on their stability in bone tissue over extended period of time, i.e. on osseointegration. The process through which osseointegration is achieved depends on several factors, surgical insertion method being one of them. The aim of this study was to histopathologically compare the impact of the surgical method of implant insertion on the peri-implant bone tissue. Methods. The experiment was performed on 9 dogs. Eight weeks following the extraction of lower premolars implants were inserted using the one-stage method on the right mandibular side and two-stage method on the left side. Three months after implantation the animals were sacrificed. Three distinct regions of bone tissue were histopathologically analyzed, the results were scored and compared. Results. In the specimens of one-stage implants increased amount of collagen fibers was found in 5 specimens where tissue necrosis was also observed. Only moderate osteoblastic activity was found in 3 sections. The analysis of bone-to-implant contact region revealed statistically significantly better results regarding the amount of collagen tissue fibers for the implants inserted in the two-stage method (Wa = 59 105, α = 0.05. No necrosis and osteoblastic activity were observed. Conclusion. Better results were achieved by the two-stage method in bone-to-implant contact region regarding the amount of collagen tissue, while the results were identical regarding the osteoblastic activity and bone tissue necrosis. There was no difference between the methods in the bone-implant interface region. In the bone tissue adjacent to the implant the results were identical regarding the amount of collagen tissue, osteoblastic reaction and bone tissue necrosis, while better results were achieved by the two-stage method regarding the number of osteocytes.

  13. Unusual endosteally formed bone tissue in a patagonian basal sauropodomorph dinosaur.

    Science.gov (United States)

    Cerda, Ignacio A; Chinsamy, Anusuya; Pol, Diego

    2014-08-01

    Mussaurus patagonicus (Dinosauria: Sauropodomorpha) is a basal sauropodomorph from the Late Triassic of southern Argentina that is known from a large number of individuals, including juveniles, subadults, and adults. Here, we report on the occurrence of an unusual bone tissue in an individual of M. patagonicus. The rather atypical bone tissue is located within the femoral medullary cavity and also occurs within several erosion cavities of the midinner part of the cortex. This tissue is well vascularized and is composed of a matrix that consists of abundant and densely packed osteocyte lacunae. Although some features of this tissue resembles avian medullary bone, the histological features are distinctive and share more features with the pathological, reactive bone produced in extant birds in response to a retrovirus-induced disease (avian osteopetrosis). Here, we also discuss and provide histological features to effectively differentiate endosteally formed medullary bone from pathological avian osteopetrosis.

  14. From natural bone grafts to tissue engineering therapeutics: Brainstorming on pharmaceutical formulative requirements and challenges.

    Science.gov (United States)

    Baroli, Biancamaria

    2009-04-01

    Tissue engineering is an emerging multidisciplinary field of investigation focused on the regeneration of diseased or injured tissues through the delivery of appropriate molecular and mechanical signals. Therefore, bone tissue engineering covers all the attempts to reestablish a normal physiology or to speed up healing of bone in all musculoskeletal disorders and injuries that are lashing modern societies. This article attempts to give a pharmaceutical perspective on the production of engineered man-made bone grafts that are described as implantable tissue engineering therapeutics, and to highlight the importance of understanding bone composition and structure, as well as osteogenesis and bone healing processes, to improve the design and development of such implants. In addition, special emphasis is given to pharmaceutical aspects that are frequently minimized, but that, instead, may be useful for formulation developments and in vitro/in vivo correlations.

  15. Fabrication and characterization of electrospun osteon mimicking scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Andric, T. [Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Sampson, A.C. [Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Freeman, J.W., E-mail: jwfreeman@vt.edu [Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

    2011-01-01

    Skeletal loss and bone deficiencies are a major worldwide problem with over 600,000 procedures performed in the US alone annually, making bone one of the most transplanted tissues, second to blood only. Bone is a composite tissue composed of organic matrix, inorganic bone mineral, and water. Structurally bone is organized into two distinct types: trabecular (or cancellous) and cortical (or compact) bones. Trabecular bone is characterized by an extensive interconnected network of pores. Cortical bone is composed of tightly packed units, called osteons, oriented parallel along to the axis of the bone. While the majority of scaffolds attempt to replicate the structure of the trabecular bone, fewer attempts have been made to create scaffolds to mimic the structure of cortical bone. The aim of this study was to develop a technique to fabricate scaffolds that mimic the organization of an osteon, the structural unit of cortical bone. We successfully built a rotating stage for PGA fibers and utilized it for collecting electrospun nanofibers and creating scaffolds. Resulting scaffolds consisted of concentric layers of electrospun PLLA or gelatin/PLLA nanofibers wrapped around PGA microfiber core with diameters that ranged from 200 to 600 {mu}m. Scaffolds were mineralized by incubation in 10x simulated body fluid, and scaffolds composed of 10%gelatin/PLLA had significantly higher amounts of calcium phosphate. The electrospun scaffolds also supported cellular attachment and proliferation of MC3T3 cells over the period of 28 days.

  16. Biomimetic composite scaffolds containing bioceramics and collagen/gelatin for bone tissue engineering - A mini review.

    Science.gov (United States)

    Kuttappan, Shruthy; Mathew, Dennis; Nair, Manitha B

    2016-12-01

    Bone is a natural composite material consisting of an organic phase (collagen) and a mineral phase (calcium phosphate, especially hydroxyapatite). The strength of bone is attributed to the apatite, while the collagen fibrils are responsible for the toughness and visco-elasticity. The challenge in bone tissue engineering is to develop such biomimetic composite scaffolds, having a balance between biological and biomechanical properties. This review summarizes the current state of the field by outlining composite scaffolds made of gelatin/collagen in combination with bioactive ceramics for bone tissue engineering application.

  17. Microarchitectural adaptations in aging and osteoarthrotic subchondral bone tissues

    DEFF Research Database (Denmark)

    Ding, Ming

    2010-01-01

    The human skeleton optimizes its microarchitecture by elaborate adaptations to mechanical loading during development and growth. The mechanisms for adaptation involve a multistep process of cellular mechanotransduction stimulating bone modelling, and remodeling resulting in either bone formation...... into the age-related and OA-related subchondral bone adaptations.   Microarchitectural adaptation in human aging cancellous bone The precision of micro-CT measurement is excellent. Accurate 3-D micro-CT image datasets can be generated by applying an appropriate segmentation threshold. A fixed threshold may...... and the constant nature of connectivity suggest an important bone remodeling mechanism that normal aging tibia may adapt trabecular volume orientation. Namely, that the aging trabeculae align preferentially to the primary loading direction to compensate bone loss (III). Age-related changes in trabecular thickness...

  18. Instrumental and laboratory assessment of stressful remodelling processes in bone tissue at total hip replacement

    Directory of Open Access Journals (Sweden)

    E.V. Karjakina

    2010-06-01

    Full Text Available Research objective is to estimate stressful remodelling features of bone tissue according to the densitometry data and to the level of biochemical markers of bone resorption and formation in total hip replacement (THR. Bone tissue mineral density (BTMD, condition of calcium-phosphoric metabolism and biochemical markers of bone formation (osteocalcin and bone isoenzyme of alkaline phosphatase and resorption (С-terminal bodypeptide of the I type collagen have been determined in 52 patients with coxarthrosis of ll-lll stages with marked joint dysfunction before and after THR. The control group included 24 donors. The data were considered to be reliable when the probability index was р<0,05. The reliable (р<0,05 change of BTMD was determined only in 3-6 months after the operation, whereas the change of biochemical markers of remodeling had already been done after 1,5-3 months, allowing to define the group of patients with obvious negative bone balance: strong predominance of resorption processes without compensation of the subsequent adequate osteogenesis, that subsequently could lead to significant bone tissue deficiency in the area adjacent to the endoprosthesis. Changes of indices of calcium-phosphoric metabolism were not certain during the investigation term. ln conclusion it is to state that biochemical markers of remodeling in comparison with BTMD allow to estimate objectively features of adaptive bone tissue remodeling after THR in earlier periods and to define group of patients with sharp intensification of metabolism and obvious negative bone balance

  19. Recent progresses in gene delivery-based bone tissue engineering.

    Science.gov (United States)

    Lu, Chia-Hsin; Chang, Yu-Han; Lin, Shih-Yeh; Li, Kuei-Chang; Hu, Yu-Chen

    2013-12-01

    Gene therapy has converged with bone engineering over the past decade, by which a variety of therapeutic genes have been delivered to stimulate bone repair. These genes can be administered via in vivo or ex vivo approach using either viral or nonviral vectors. This article reviews the fundamental aspects and recent progresses in the gene therapy-based bone engineering, with emphasis on the new genes, viral vectors and gene delivery approaches.

  20. Thermostability of bone tissue after immobilization induced osteopenia in a rat model.

    Directory of Open Access Journals (Sweden)

    Krzysztof Wójtowicz

    2008-12-01

    Full Text Available Immobilization of load-bearing bones results in imbalance of bone turnover followed by bone loss and impairment of its mechanical function. The question is whether immobilization induced bone loss is accompanied by deterioration of properties of the bone tissue components. Thermally induced transformations of collagen reflect the overall condition of the structure and cross-links in collagen network. The aim of the present study was to investigate whether immobilization induced osteopenia effects stability of collagen in bone tissue. Bone loss was developed by unilateral hindlimb immobilization in adult rats. Effects of unloading on cortical tissue from tibiae were studied after three weeks of unloading (I3R0 and four weeks after remobilization and free convalescence (I3R4 in both tibiae. Thermodynamic parameters of collagen degradation in bone were determined from differential scanning calorimetry (DSC analysis of partially dehydrated cortical bone samples from tibiae in the range of temperatures from 60 degrees C up to 300 degrees C. All bone samples were thermally very stable showing first clear endothermal process with a peak temperature within a range from 150 degrees C to 169 degrees C, for different samples. The next endotherm, wider and flatter, was observed between 245-298 degrees C with a peak at 255 degrees C - 260 degrees C. There were significant side-to-side (right to left differences for both endothermal processes in tibiae samples from experimental groups: I3R0 and I3R4. Immobilization of load-bearing bones influences stability of collagen in bone tissue. Free remobilization was not sufficient for recovery of thermal parameters of bone.

  1. A TETRACYCLINE LABELING STUDY OF SUBCHONDRAL BONE TISSUES IN OSTEOARTHRITIC HIP JOINT

    Institute of Scientific and Technical Information of China (English)

    徐荣辉; 柴本甫

    1992-01-01

    Seven female patients (mean age of 56 years) with advanced hip joint osteoarthritis underwent total hip replacement. Four days before operation they were given oral tetracycline for two days. During operation specimens were taken from the white articular cartilage, the yellowish articular cartilage and the ivory bone together with their subchondral bone tissues. The undecalcified specimens were cut into 10 μm sections and observed under the fluorescence microscope. In all the specimens the following findings could be observed. 1. The osteoarthritic articular cartilage became thinner, with uneven surface and fissures. 2. The superficial and deep surfaces and the central part of the subchondral bone plate showed bright golden yellow fluorescence. It reflected extensive new bone formation. 3. The subchondral bone trabeculae also revealed bright golden yellow fluorescence on their peripheral borders, so trabeculae turned thicker obviously. 4. The marrow tissues between the bone trabeculae exhibited particulate or spherical bright golden yellow fluorescence, reflecting new bone formation in the marrow. The particulate and spherical bright golden yellow fluorescent materials might aggregate, enlarge and merge into large piece of new bone and they also fused with the neighbouring bone trabeculae. The aforementioned changes in the structure of the subchondral bone tissues increased greatly the mass in the osteoarthritic femoral head.

  2. Quantitative plutonium microdistribution in bone tissue of vertebra from a Mayak worker.

    Science.gov (United States)

    Lyovkina, Yekaterina V; Miller, Scott C; Romanov, Sergey A; Krahenbuhl, Melinda P; Belosokhov, Maxim V

    2010-10-01

    The purpose of this study was to obtain quantitative data on plutonium microdistribution in different structural elements of human bone tissue for local dose assessment and dosimetric models validation. A sample of the thoracic vertebra was obtained from a former Mayak worker with a rather high plutonium burden. Additional information was obtained on occupational and exposure history, medical history, and measured plutonium content in organs. Plutonium was detected in bone sections from its fission tracks in polycarbonate film using neutron-induced autoradiography. Quantitative analysis of randomly selected microscopic fields on one of the autoradiographs was performed. Data included fission fragment tracks in different bone tissue and surface areas. Quantitative information on plutonium microdistribution in human bone tissue was obtained for the first time. From these data, the quantitative relationships of plutonium decays in bone volume to decays on bone surface in cortical and trabecular fractions were defined as 2.0 and 0.4, correspondingly. The measured quantitative relationship of decays in bone volume to decays on bone surface does not coincide with recommended models for the cortical bone fraction by the International Commission on Radiological Protection. Biokinetic model parameters of extrapulmonary compartments might need to be adjusted after expansion of the data set on quantitative plutonium microdistribution in other bone types in humans as well as other cases with different exposure patterns and types of plutonium.

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

    Directory of Open Access Journals (Sweden)

    Carlo Maiorana

    2016-01-01

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

  4. Imaging regenerating bone tissue based on neural networks applied to micro-diffraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Campi, G.; Pezzotti, G. [Institute of Crystallography, CNR, via Salaria Km 29.300, I-00015, Monterotondo Roma (Italy); Fratini, M. [Centro Fermi -Museo Storico della Fisica e Centro Studi e Ricerche ' Enrico Fermi' , Roma (Italy); Ricci, A. [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg (Germany); Burghammer, M. [European Synchrotron Radiation Facility, B. P. 220, F-38043 Grenoble Cedex (France); Cancedda, R.; Mastrogiacomo, M. [Istituto Nazionale per la Ricerca sul Cancro, and Dipartimento di Medicina Sperimentale dell' Università di Genova and AUO San Martino Istituto Nazionale per la Ricerca sul Cancro, Largo R. Benzi 10, 16132, Genova (Italy); Bukreeva, I.; Cedola, A. [Institute for Chemical and Physical Process, CNR, c/o Physics Dep. at Sapienza University, P-le A. Moro 5, 00185, Roma (Italy)

    2013-12-16

    We monitored bone regeneration in a tissue engineering approach. To visualize and understand the structural evolution, the samples have been measured by X-ray micro-diffraction. We find that bone tissue regeneration proceeds through a multi-step mechanism, each step providing a specific diffraction signal. The large amount of data have been classified according to their structure and associated to the process they came from combining Neural Networks algorithms with least square pattern analysis. In this way, we obtain spatial maps of the different components of the tissues visualizing the complex kinetic at the base of the bone regeneration.

  5. Breast Cancer Cell Colonization of the Human Bone Marrow Adipose Tissue Niche

    Directory of Open Access Journals (Sweden)

    Zach S. Templeton

    2015-12-01

    Full Text Available BACKGROUND/OBJECTIVES: Bone is a preferred site of breast cancer metastasis, suggesting the presence of tissue-specific features that attract and promote the outgrowth of breast cancer cells. We sought to identify parameters of human bone tissue associated with breast cancer cell osteotropism and colonization in the metastatic niche. METHODS: Migration and colonization patterns of MDA-MB-231-fLuc-EGFP (luciferase-enhanced green fluorescence protein and MCF-7-fLuc-EGFP breast cancer cells were studied in co-culture with cancellous bone tissue fragments isolated from 14 hip arthroplasties. Breast cancer cell migration into tissues and toward tissue-conditioned medium was measured in Transwell migration chambers using bioluminescence imaging and analyzed as a function of secreted factors measured by multiplex immunoassay. Patterns of breast cancer cell colonization were evaluated with fluorescence microscopy and immunohistochemistry. RESULTS: Enhanced MDA-MB-231-fLuc-EGFP breast cancer cell migration to bone-conditioned versus control medium was observed in 12/14 specimens (P = .0014 and correlated significantly with increasing levels of the adipokines/cytokines leptin (P = .006 and IL-1β (P = .001 in univariate and multivariate regression analyses. Fluorescence microscopy and immunohistochemistry of fragments underscored the extreme adiposity of adult human bone tissues and revealed extensive breast cancer cell colonization within the marrow adipose tissue compartment. CONCLUSIONS: Our results show that breast cancer cells migrate to human bone tissue-conditioned medium in association with increasing levels of leptin and IL-1β, and colonize the bone marrow adipose tissue compartment of cultured fragments. Bone marrow adipose tissue and its molecular signals may be important but understudied components of the breast cancer metastatic niche.

  6. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    DEFF Research Database (Denmark)

    Wittig, Nina; Bach-Gansmo, Fiona Linnea; Birkbak, Mie Elholm;

    2016-01-01

    of bone on the organ and tissue level, whereas features on the nano- and micrometer scale are much less explored. We investigated the age-related development of organ and tissue level bone properties such as bone volume, bone mineral density, and load to fracture and correlated these with osteocyte...... orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties...

  7. Bone And Soft Tissue Changes In Patients With Spinal Cord Injury And Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Dionyssiotis Yannis

    2014-12-01

    Full Text Available In patients with spinal cord injury and multiple sclerosis, deterioration of body composition (changes in bone, fat and muscle mass is associated with increased risk for diseases such as coronary artery heart disease, non-insulin dependent diabetes mellitus, lipid metabolism abnormalities, and osteoporotic fractures in these patients. Immobility leads to a changing pattern of loading in the paralyzed areas, and secondary alteration in structure. However, bone and soft tissue changes in these patients are usually neglected. The purpose of this article is to update on the pathophysiological mechanisms leading to bone and soft tissue changes, and to increase the awareness of the treating physicians with respect to bone, muscle and fat loss and their consequences aiming to obtain measures to prevent bone and soft tissue loss in these patients.

  8. Bioactive Glass and Glass-Ceramic Scaffolds for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Aldo R. Boccaccini

    2010-07-01

    Full Text Available Traditionally, bioactive glasses have been used to fill and restore bone defects. More recently, this category of biomaterials has become an emerging research field for bone tissue engineering applications. Here, we review and discuss current knowledge on porous bone tissue engineering scaffolds on the basis of melt-derived bioactive silicate glass compositions and relevant composite structures. Starting with an excerpt on the history of bioactive glasses, as well as on fundamental requirements for bone tissue engineering scaffolds, a detailed overview on recent developments of bioactive glass and glass-ceramic scaffolds will be given, including a summary of common fabrication methods and a discussion on the microstructural-mechanical properties of scaffolds in relation to human bone (structure-property and structure-function relationship. In addition, ion release effects of bioactive glasses concerning osteogenic and angiogenic responses are addressed. Finally, areas of future research are highlighted in this review.

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

    Science.gov (United States)

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

    2014-10-01

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

  10. Human dental pulp stem cell is a promising autologous seed cell for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    LI Jing-hui; LIU Da-yong; ZHANG Fang-ming; WANG Fan; ZHANG Wen-kui; ZHANG Zhen-ting

    2011-01-01

    Background The seed cell is a core problem in bone tissue engineering research.Recent research indicates that human dental pulp stem cells (hDPSCs) can differentiate into osteoblasts in vitro,which suggests that they may become a new kind of seed cells for bone tissue engineering.The aim of this study was to evaluate the osteogenic differentiation of hDPSCs in vitro and bone-like tissue formation when transplanted with three-dimensional gelatin scaffolds in vivo,and hDPSCs may become appropriate seed cells for bone tissue engineering.Methods We have utilized enzymatic digestion to obtain hDPSCs from dental pulp tissue extracted during orthodontic treatment.After culturing and expansion to three passages,the cells were seeded in 6-well plates or on three-dimensional gelatin scaffolds and cultured in osteogenic medium.After 14 days in culture,the three-dimensional gelatin scaffolds were implanted subcutaneously in nude mice for 4 weeks.In 6-well plate culture,osteogenesis was assessed by alkaline phosphatase staining,Von Kossa staining,and reverse transcription-polymerase chain reaction (RT-PCR) analysis of the osteogenesis-specific genes type I collagen (COL l),bone sialoprotein (BSP),osteocalcin (OCN),RUNX2,and osterix (OSX).In three-dimensional gelatin scaffold culture,X-rays,hematoxylin/eosin staining,and immunohistochemical staining were used to examine bone formation.Results In vitro studies revealed that hDPSCs do possess osteogenic differentiation potential.In vivo studies revealed that hDPSCs seeded on gelatin scaffolds can form bone structures in heterotopic sites of nude mice.Conclusions These findings suggested that hDPSCs may be valuable as seed cells for bone tissue engineering.As a special stem cell source,hDPSCs may blaze a new path for bone tissue engineering.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  12. Lamellar bone is an incremental tissue reconciling enamel rhythms, body size, and organismal life history.

    Science.gov (United States)

    Bromage, Timothy G; Lacruz, Rodrigo S; Hogg, Russell; Goldman, Haviva M; McFarlin, Shannon C; Warshaw, Johanna; Dirks, Wendy; Perez-Ochoa, Alejandro; Smolyar, Igor; Enlow, Donald H; Boyde, Alan

    2009-05-01

    Mammalian enamel formation is periodic, including fluctuations attributable to the daily biological clock as well as longer-period oscillations that enigmatically correlate with body mass. Because the scaling of bone mass to body mass is an axiom of vertebrate hard tissue biology, we consider that long-period enamel formation rhythms may reflect corresponding and heretofore unrecognized rhythms in bone growth. The principal aim of this study is to seek a rhythm in bone growth demonstrably related to enamel oscillatory development. Our analytical approach is based in morphology, using a variety of hard tissue microscopy techniques. We first ascertain the relationship among long-period enamel rhythms, the striae of Retzius, and body mass using a large sample of mammalian taxa. In addition, we test whether osteocyte lacuna density (a surrogate for rates of cell proliferation) in bone is correlated with mammalian body mass. Finally, using fluorescently labeled developing bone tissues, we investigate whether the bone lamella, a fundamental microanatomical unit of bone, relates to rhythmic enamel growth increments. Our results confirm a positive correlation between long-period enamel rhythms and body mass and a negative correlation between osteocyte density and body mass. We also confirm that lamellar bone is an incremental tissue, one lamella formed in the species-specific time dependency of striae of Retzius formation. We conclude by contextualizing our morphological research with a current understanding of autonomic regulatory control of the skeleton and body mass, suggesting a central contribution to the coordination of organismal life history and body mass.

  13. Open forward and inverse problems in theoretical modeling of bone tissue adaptation.

    Science.gov (United States)

    Zadpoor, Amir Abbas

    2013-11-01

    Theoretical modeling of bone tissue adaptation started several decades ago. Many important problems have been addressed in this area of research during the last decades. However, many important questions remain unanswered. In this paper, an overview of open problems in theoretical modeling of bone tissue adaptation is presented. First, the principal elements of bone tissue adaptation models are defined and briefly reviewed. Based on these principal elements, four categories of open problems are identified. Two of these categories primarily include forward problems, while two others include inverse problems. In every one of the identified categories, important open problems are highlighted and their importance is discussed. It is shown that most of previous studies on the theoretical modeling of bone tissue adaptation have been focused on the problems of the first category and not much is done in three other categories. The paper tries to highlight these potentially important problems that have been so far largely overlooked and to inspire new avenues of research.

  14. Bioceramic-collagen scaffolds loaded with human adipose-tissue derived stem cells for bone tissue engineering.

    Science.gov (United States)

    Daei-Farshbaf, Neda; Ardeshirylajimi, Abdolreza; Seyedjafari, Ehsan; Piryaei, Abbas; Fadaei Fathabady, Fatemeh; Hedayati, Mehdi; Salehi, Mohammad; Soleimani, Masoud; Nazarian, Hamid; Moradi, Sadegh-Lotfalah; Norouzian, Mohsen

    2014-02-01

    The combination of bioceramics and stem cells has attracted the interest of research community for bone tissue engineering applications. In the present study, a combination of Bio-Oss(®) and type 1 collagen gel as scaffold were loaded with human adipose-tissue derived mesenchymal stem cells (AT-MSCs) after isolation and characterization, and the capacity of them for bone regeneration was investigated in rat critical size defects using digital mammography, multi-slice spiral computed tomography imaging and histological analysis. 8 weeks after implantation, no mortality or sign of inflammation was observed in the site of defect. According to the results of imaging analysis, a higher level of bone regeneration was observed in the rats receiving Bio-Oss(®)-Gel compared to untreated group. In addition, MSC-seeded Bio-Oss-Gel induced the highest bone reconstruction among all groups. Histological staining confirmed these findings and impressive osseointegration was observed in MSC-seeded Bio-Oss-Gel compared with Bio-Oss-Gel. On the whole, it was demonstrated that combination of AT-MSCs, Bio-Oss and Gel synergistically enhanced bone regeneration and reconstruction and also could serve as an appropriate structure to bone regenerative medicine and tissue engineering application.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-01

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

  16. Microhardness of Bone Tissue After Different Alloy Implantation

    Directory of Open Access Journals (Sweden)

    Nataliia Zaitseva

    2015-09-01

    Full Text Available Integral indicator of bone quality is microhardness, which depends both on the condition of the inorganic component and the quality of the extracellular organic matrix. There are a lot of researches indicated microhardness changes around the metal implants, but it is not clear how it change distant from injured place. The aim of our research was to determine the microhardness of the femoral bone at different terms after the implantation of metal alloys with different composition. 65 rabbits were random in 5 groups – intact, control (bone defect and 3 experimental. We used TiVT6 alloy with high elasticity module and β- (Ti-Zr alloy with low Young module for the experimental groups. All alloys were implanted in distal epiphysis of femur. Bone microhardness was detected in periimplanted zone as well as in middle of diaphysis and proximal epiphysis. Injury of bone leads to a decrease in the hardness in the zone of the defec as well as in distal zones, followed by recovery up to 6 month. Use the classic high-modulus alloy TiVT6 leads to a significant decrease in the microhardness of all sections of bone in the early and late postoperative period. Implantation of low modulus alloy β (Ti-Zr leads to a reduction of hardness just after 1 and 3 months after the injury, and the use of hydroxyapatite coating significantly reduces the loss of bone quality at all times after implantation.

  17. Bone tissue response to plasma-nitrided titanium implant surfaces

    Directory of Open Access Journals (Sweden)

    Emanuela Prado FERRAZ

    2015-02-01

    Full Text Available A current goal of dental implant research is the development of titanium (Ti surfaces to improve osseointegration. Plasma nitriding treatments generate surfaces that favor osteoblast differentiation, a key event to the process of osteogenesis. Based on this, it is possible to hypothesize that plasma-nitrided Ti implants may positively impact osseointegration. Objective The aim of this study was to evaluate the in vivo bone response to Ti surfaces modified by plasma-nitriding treatments. Material and Methods Surface treatments consisted of 20% N2 and 80% H2, 450°C and 1.5 mbar during 1 h for planar and 3 h for hollow cathode. Untreated surface was used as control. Ten implants of each surface were placed into rabbit tibiae and 6 weeks post-implantation they were harvested for histological and histomorphometric analyses. Results Bone formation was observed in contact with all implants without statistically significant differences among the evaluated surfaces in terms of bone-to-implant contact, bone area between threads, and bone area within the mirror area. Conclusion Our results indicate that plasma nitriding treatments generate Ti implants that induce similar bone response to the untreated ones. Thus, as these treatments improve the physico-chemical properties of Ti without affecting its biocompatibility, they could be combined with modifications that favor bone formation in order to develop new implant surfaces.

  18. Bone Regeneration Based on Tissue Engineering Conceptions-A 21st Century Perspective

    Institute of Scientific and Technical Information of China (English)

    Jan Henkel; Maria A. Woodruff; Devakara R. Epari; Roland Steck; Vaida Glatt; Ian C. Dickinson; Peter FM Choong; Michael A. Schuetz; Dietmar W. Hutmacher

    2013-01-01

    The role of Bone Tissue Engineering in the field of Regenerative Medicine has been the topic of substantial research over the past two decades. Technological advances have improved orthopaedic implants and surgical techniques for bone reconstruction. However, improvements in surgical techniques to reconstruct bone have been limited by the paucity of autologous materials available and donor site morbidity. Recent advances in the development of biomaterials have provided attractive alternatives to bone grafting expanding the surgical options for restoring the form and function of injured bone. Specifically, novel bioactive (second generation) biomaterials have been developed that are characterised by controlled action and reaction to the host tissue environment, whilst exhibiting controlled chemical breakdown and resorption with an ultimate replacement by regenerating tissue. Future generations of biomaterials (third generation) are designed to be not only osteo-conductive but also osteoinductive, i.e. to stimulate regeneration of host tissues by combining tissue engineer-ing and in situ tissue regeneration methods with a focus on novel applications. These techniques will lead to novel possibilities for tissue regeneration and repair. At present, tissue engineered constructs that may find future use as bone grafts for complex skeletal defects, whether from post-traumatic, degenerative, neoplastic or congenital/developmental“origin”require osseous reconstruction to ensure structural and functional integrity. Engineering functional bone using combinations of cells, scaffolds and bioactive factors is a promising strategy and a particular feature for future development in the area of hybrid materials which are able to exhibit suitable biomimetic and mechanical properties. This review will discuss the state of the art in this field and what we can expect from future generations of bone regeneration concepts.

  19. Human bone hardness seems to depend on tissue type but not on anatomical site in the long bones of an old subject.

    Science.gov (United States)

    Ohman, Caroline; Zwierzak, Iwona; Baleani, Massimiliano; Viceconti, Marco

    2013-02-01

    It has been hypothesised that among different human subjects, the bone tissue quality varies as a function of the bone segment morphology. The aim of this study was to assess and compare the quality, evaluated in terms of hardness of packages of lamellae, of cortical and trabecular bones, at different anatomical sites within the human skeleton. The contralateral six long bones of an old human subject were indented at different levels along the diaphysis and at both epiphyses of each bone. Hardness value, which is correlated to the degree of mineralisation, of both cortical and trabecular bone tissues was calculated for each indentation location. It was found that the cortical bone tissue was harder (+18%) than the trabecular one. In general, the bone hardness was found to be locally highly heterogeneous. In fact, considering one single slice obtained for a bone segment, the coefficient of variation of the hardness values was up to 12% for cortical bone and up to 17% for trabecular bone. However, the tissue hardness was on average quite homogeneous within and among the long bones of the studied donor, although differences up to 9% among levels and up to 7% among bone segments were found. These findings seem not to support the mentioned hypothesis, at least not for the long bones of an old subject.

  20. Mechanical Stimulus Inhibits the Growth of a Bone Tissue Model Cultured In Vitro

    Institute of Scientific and Technical Information of China (English)

    Zong-ming Wan; Lu Liu; Jian-yu Li; Rui-xin Li; Yong Guo; Hao Li; Jian-ming Zhang; Xi-zheng Zhang

    2013-01-01

    Objectives To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vitro. Methods Cancellous bone were extracted from rabbit femoral head and cut into 1-mm-thick and 8-mm-diameter slices under sterile conditions. HE staining and scanning electron microscopy were employed to identify the histomorphology of the model after being cultured with a new dynamic load and circulating perfusion bioreactor system for 0, 3, 5, and 7 days, respectively. We built a three-dimensional model using microCT and analyzed the loading effects using finite element analysis. The model was subjected to mechanical load of 1000, 2000, 3000, and 4000μεrespectively for 30 minutes per day. After 5 days of continuous stimuli, the activities of alkaline phosphatase (AKP) and tartrate-resistant acid phosphatase (TRAP) were detected. Apoptosis was analyzed by DNA ladder detection and caspase-3/8/9 activity detection. Results After being cultured for 3, 5, and 7 days, the bone explant model grew well. HE staining showed the apparent nucleus in cells at the each indicated time, and electron microscope revealed the living cells in the bone tissue. The activities of AKP and TRAP in the bone explant model under mechanical load of 3000 and 4000μεwere significantly lower than those in the unstressed bone tissues (all P Conclusions The cancellous bone explant model extracted from the rabbit femoral head could be alive at least for 7 days in the dynamic load and circulating perfusion bioreactor system, however, pathological mechanical load could affect the bone tissue growth by apoptosis in vitro. The differentiation of osteoblasts and osteoclasts might be inhibited after the model is stimulated by mechanical load of 3000 and 4000με.

  1. Troglitazone treatment increases bone marrow adipose tissue volume but does not affect trabecular bone volume in mice

    DEFF Research Database (Denmark)

    Erikstrup, Lise Tornvig; Mosekilde, Leif; Justesen, J;

    2001-01-01

    proliferator activated receptor-gamma (PPARgamma). Histomorphometric analysis of proximal tibia was performed in order to quantitate the amount of trabecular bone volume per total volume (BV/TV %), adipose tissue volume per total volume (AV/TV %), and hematopoietic marrow volume per total volume (HV...

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

    Science.gov (United States)

    Kulakov, A A; Grigor'ian, A S

    2014-01-01

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

  3. Guided tissue regeneration using a collagen barrier and bone swaging technique in noncontained infrabony defects.

    Science.gov (United States)

    Kodama, Toshiro; Minabe, Masato; Sugiyama, Takashi; Mitarai, Eiko; Fushimi, Hajime; Kitsugi, Daisuke; Tsutsumi, Kouji; Katsuki, Makiko

    2013-01-01

    This clinical study evaluated the effectiveness of guided tissue regeneration using a resorbable collagen membrane and bone swaging in noncontained infrabony defects by assessing changes in probing pocket depth, probing attachment level, and radiographic bone level after 6 months, 1 year, and 2 years. Postsurgical clinical and radiographic measurements were statistically significantly different from presurgical measurements. The rate of bone fill was positively associated with the baseline depth of the bone defect but not associated with the width. The noncontained infrabony defects treated with this combined regenerative method improved clinically and radiographically.

  4. Biodegradable hybrid tissue engineering scaffolds for reconstruction of large bone defects

    Science.gov (United States)

    Barati, Danial

    Complex skeletal injuries and large bone fractures are still a significant clinical problem in US. Approximately 1.5 million Americans (veterans, their families, and civilians) every year suffer from bone loss due to traumatic skeletal injuries, infection, and resection of primary tumors that require extensive grafting to bridge the gap. The US bone graft market is over $2.2 billion a year. Due to insufficient mechanical stability, lack of vascularity, and inadequate resorption of the graft, patients with traumatic large skeletal injuries undergo multiple costly operations followed by extensive recovery steps to maintain proper bone alignment and length. Current strategies for repairing damaged or diseased bones include autologous or allograft bone transplantations. However, limited availability of autografts and risk of disease transmission associated with allografts have necessitated the search for the development of new bone graft options and strategies. The overall goal of this project is to develop a much-needed bone-mimetic engineered graft as a substitute for current strategies providing required bone grafts for reconstruction of large bone defects. This project will use the structure of natural cortical bone as a guide to produce an engineered bone graft with balanced strength, osteogenesis, vascularization, and resorption. The outcome of this project will be a biodegradable hybrid scaffold system (similar to natural cortical bone) including a mechanically strong scaffold allowing for mechanical stability of the load-bearing defect site and a soft and highly porous structure such as a hydrogel phase which will allow for efficient cell and growth factor delivery into the defect implantation site, cell niche establishment and promotion of mineralization. Successful completion of this project will transform bone graft technology for regeneration of complex bone defects from a frozen or freeze-dried allograft to a safe, infection-free, mechanically

  5. Engraftment of Prevascularized, Tissue Engineered Constructs in a Novel Rabbit Segmental Bone Defect Model

    Directory of Open Access Journals (Sweden)

    Alexandre Kaempfen

    2015-06-01

    Full Text Available The gold standard treatment of large segmental bone defects is autologous bone transfer, which suffers from low availability and additional morbidity. Tissue engineered bone able to engraft orthotopically and a suitable animal model for pre-clinical testing are direly needed. This study aimed to evaluate engraftment of tissue-engineered bone with different prevascularization strategies in a novel segmental defect model in the rabbit humerus. Decellularized bone matrix (Tutobone seeded with bone marrow mesenchymal stromal cells was used directly orthotopically or combined with a vessel and inserted immediately (1-step or only after six weeks of subcutaneous “incubation” (2-step. After 12 weeks, histological and radiological assessment was performed. Variable callus formation was observed. No bone formation or remodeling of the graft through TRAP positive osteoclasts could be detected. Instead, a variable amount of necrotic tissue formed. Although necrotic area correlated significantly with amount of vessels and the 2-step strategy had significantly more vessels than the 1-step strategy, no significant reduction of necrotic area was found. In conclusion, the animal model developed here represents a highly challenging situation, for which a suitable engineered bone graft with better prevascularization, better resorbability and higher osteogenicity has yet to be developed.

  6. The effect of osteoporosis treatments on fatigue properties of cortical bone tissue

    Directory of Open Access Journals (Sweden)

    Garry R. Brock

    2015-06-01

    Full Text Available Bisphosphonates are commonly prescribed for treatment of osteoporosis. Long-term use of bisphosphonates has been correlated to atypical femoral fractures (AFFs. AFFs arise from fatigue damage to bone tissue that cannot be repaired due to pharmacologic treatments. Despite fatigue being the primary damage mechanism of AFFs, the effects of osteoporosis treatments on fatigue properties of cortical bone are unknown. To examine if fatigue-life differences occur in bone tissue after different pharmacologic treatments for osteoporosis, we tested bone tissue from the femurs of sheep given a metabolic acidosis diet to induce osteoporosis, followed by treatment with a selective estrogen reception modulator (raloxifene, a bisphosphonate (alendronate or zoledronate, or parathyroid hormone (teriparatide, PTH. Beams of cortical bone tissue were created and tested in four-point bending fatigue to failure. Tissue treated with alendronate had reduced fatigue life and less modulus loss at failure compared with other treatments, while tissue treated with PTH had a prolonged fatigue life. No loss of fatigue life occurred with zoledronate treatment despite its greater binding affinity and potency compared with alendronate. Tissue mineralization measured by microCT did not explain the differences seen in fatigue behavior. Increased fatigue life with PTH suggests that current treatment methods for AFF could have beneficial effects for restoring fatigue life. These results indicate that fatigue life differs with each type of osteoporosis treatment.

  7. Gene Expression Changes in Femoral Head Necrosis of Human Bone Tissue

    Directory of Open Access Journals (Sweden)

    Bernadett Balla

    2011-01-01

    Full Text Available Osteonecrosis of the femoral head (ONFH is the result of an interruption of the local circulation and the injury of vascular supply of bone. Multiple factors have been implicated in the development of the disease. However the mechanism of ischemia and necrosis in non-traumatic ONFH is not clear. The aim of our investigation was to identify genes that are differently expressed in ONFH vs. non-ONFH human bone and to describe the relationships between these genes using multivariate data analysis. Six bone tissue samples from ONFH male patients and 8 bone tissue samples from non-ONFH men were examined. The expression differences of selected 117 genes were analyzed by TaqMan probe-based quantitative real-time RT-PCR system. The significance test indicated marked differences in the expression of nine genes between ONFH and non-ONFH individuals. These altered genes code for collagen molecules, an extracellular matrix digesting metalloproteinase, a transcription factor, an adhesion molecule, and a growth factor. Canonical variates analysis demonstrated that ONFH and non-ONFH bone tissues can be distinguished by the multiple expression profile analysis of numerous genes controlled via canonical TGFB pathway as well as genes coding for extracellular matrix composing collagen type molecules. The markedly altered gene expression profile observed in the ONFH of human bone tissue may provide further insight into the pathogenetic process of osteonecrotic degeneration of bone.

  8. Bone tissue density modification in treatment of shin pseudoarthrosis by transosseous compressive osteosynthesis

    Directory of Open Access Journals (Sweden)

    Tishkov N.V.

    2011-12-01

    Full Text Available Objective is to detect bone mineral density along the shin according to «Esperanto» levels by Hounsfield's scale. Materials and methods. The analysis of density modification in 25 patients with pseudoarthrosis of tibia with predominant localization in a lower one-third of bone has been carried out. Results. By means of computed tomography it has been revealed that the bone tissue density of the tibia in the process of false joint union when using the compressive variant of combined transosseous osteosynthesis has changed according to the regularity reproducing phase character of the accumulation of mineral substances in the bone. Conclution. The growth of mineral density of the bone tissue during treatment spreads in the directions from proximal and distal metaepiphyses to the zone of pseudoarthrosis knitting

  9. A comparative study of diazepam levels in bone marrow versus serum, saliva and brain tissue.

    Science.gov (United States)

    Takatori, T; Tomii, S; Terazawa, K; Nagao, M; Kanamori, M; Tomaru, Y

    1991-01-01

    The distribution of diazepam in biological fluids and tissues of rats was examined 1, 2, 4 and 8 h after intraperitoneal administration by using a radioimmunoassay with specific anti-diazepam antibody. The diazepam levels in serum, saliva, brain and bone marrow decreased over a period of 2 h and levelled off 4 h after administration. The diazepam concentration in bone marrow was much higher than in serum, saliva and brain, suggesting an accumulation of diazepam in this tissue. This indicates that bone marrow could be a very useful material for the detection of diazepam in skeletonized remains. The diazepam concentrations in bone marrow, serum, saliva and brain showed a linear relationship (r = 0.860-0.997), indicating that a valid estimate of diazepam concentration in blood can be made from bone marrow samples.

  10. Feasibility of endoscopic laser speckle imaging modality in the evaluation of auditory disorder: study in bone-tissue phantom

    Science.gov (United States)

    Yu, Sungkon; Jang, Seulki; Lee, Sangyeob; Park, Jihoon; Ha, Myungjin; Radfar, Edalat; Jung, Byungjo

    2016-03-01

    This study investigates the feasibility of an endoscopic laser speckle imaging modality (ELSIM) in the measurement of perfusion of flowing fluid in optical bone tissue phantom(OBTP). Many studies suggested that the change of cochlear blood flow was correlated with auditory disorder. Cochlear microcirculation occurs under the 200μm thickness bone which is the part of the internal structure of the temporal bone. Concern has been raised regarding of getting correct optical signal from hard tissue. In order to determine the possibility of the measurement of cochlear blood flow under bone tissue using the ELSIM, optical tissue phantom (OTP) mimicking optical properties of temporal bone was applied.

  11. Determination of the relationship between collagen cross-links and the bone-tissue stiffness in the porcine mandibular condyle

    NARCIS (Netherlands)

    Willems, N.M.B.K.; Mulder, L.; Bank, R.A.; Grünheid, T.; Toonder, J.M.J. den; Zentner, A.; Langenbach, G.E.J.

    2011-01-01

    Although bone-tissue stiffness is closely related to the degree to which bone has been mineralized, other determinants are yet to be identified. We, therefore, examined the extent to which the mineralization degree, collagen, and its cross-links are related to bone-tissue stiffness. A total of 50 ca

  12. Tannerella forsythia infection-induced calvarial bone and soft tissue transcriptional profiles.

    Science.gov (United States)

    Bakthavatchalu, V; Meka, A; Sathishkumar, S; Lopez, M C; Bhattacharyya, I; Boyce, B F; Mans, J J; Lamont, R J; Baker, H V; Ebersole, J L; Kesavalu, L

    2010-10-01

    Tannerella forsythia is associated with subgingival biofilms in adult periodontitis, although the molecular mechanisms contributing to chronic inflammation and loss of periodontal bone remain unclear. We examined changes in the host transcriptional profiles during a T. forsythia infection using a murine calvarial model of inflammation and bone resorption. Tannerella forsythia was injected into the subcutaneous soft tissue over calvariae of BALB/c mice for 3 days, after which the soft tissues and calvarial bones were excised. RNA was isolated and Murine GeneChip (Affymetrix, Santa Clara, CA) array analysis of transcript profiles showed that 3226 genes were differentially expressed in the infected soft tissues (P < 0.05) and 2586 genes were differentially transcribed in calvarial bones after infection. Quantitative real-time reverse transcription-polymerase chain reaction analysis of transcription levels of selected genes corresponded well with the microarray results. Biological pathways significantly impacted by T. forsythia infection in calvarial bone and soft tissue included leukocyte transendothelial migration, cell adhesion molecules (immune system), extracellular matrix-receptor interaction, adherens junction, and antigen processing and presentation. Histologic examination revealed intense inflammation and increased osteoclasts in calvariae compared with controls. In conclusion, localized T. forsythia infection differentially induces transcription of a broad array of host genes, and the profiles differ between inflamed soft tissues and calvarial bone.

  13. Non-viral gene therapy for bone tissue engineering.

    Science.gov (United States)

    Wegman, Fiona; Oner, F Cumhur; Dhert, Wouter J A; Alblas, Jacqueline

    2013-01-01

    The possibilities of using gene therapy for bone regeneration have been extensively investigated. Improvements in the design of new transfection agents, combining vectors and delivery/release systems to diminish cytotoxicity and increase transfection efficiencies have led to several successful in vitro, ex vivo and in vivo strategies. These include growth factor or short interfering ribonucleic acid (siRNA) delivery, or even enzyme replacement therapies, and have led to increased osteogenic differentiation and bone formation in vivo. These results provide optimism to consider use in humans with some of these gene-delivery strategies in the near future.

  14. [Bone tissue engineering. Reconstruction of critical sized segmental bone defects in the ovine tibia].

    Science.gov (United States)

    Reichert, J C; Epari, D R; Wullschleger, M E; Berner, A; Saifzadeh, S; Nöth, U; Dickinson, I C; Schuetz, M A; Hutmacher, D W

    2012-04-01

    Well-established therapies for bone defects are restricted to bone grafts which face significant disadvantages (limited availability, donor site morbidity, insufficient integration). Therefore, the objective was to develop an alternative approach investigating the regenerative potential of medical grade polycaprolactone-tricalcium phosphate (mPCL-TCP) and silk-hydroxyapatite (silk-HA) scaffolds.Critical sized ovine tibial defects were created and stabilized. Defects were left untreated, reconstructed with autologous bone grafts (ABG) and mPCL-TCP or silk-HA scaffolds. Animals were observed for 12 weeks. X-ray analysis, torsion testing and quantitative computed tomography (CT) analyses were performed. Radiological analysis confirmed the critical nature of the defects. Full defect bridging occurred in the autograft and partial bridging in the mPCL-TCP group. Only little bone formation was observed with silk-HA scaffolds. Biomechanical testing revealed a higher torsional moment/stiffness (p CT analysis a significantly higher amount of bone formation for the ABG group when compared to the silk-HA group. No significant difference was determined between the ABG and mPCL-TCP groups. The results of this study suggest that mPCL-TCP scaffolds combined can serve as an alternative to autologous bone grafting in long bone defect regeneration. The combination of mPCL-TCP with osteogenic cells or growth factors represents an attractive means to further enhance bone formation.

  15. Bone tissue phantoms for optical flowmeters at large interoptode spacing generated by 3D-stereolithography.

    Science.gov (United States)

    Binzoni, Tiziano; Torricelli, Alessandro; Giust, Remo; Sanguinetti, Bruno; Bernhard, Paul; Spinelli, Lorenzo

    2014-08-01

    A bone tissue phantom prototype allowing to test, in general, optical flowmeters at large interoptode spacings, such as laser-Doppler flowmetry or diffuse correlation spectroscopy, has been developed by 3D-stereolithography technique. It has been demonstrated that complex tissue vascular systems of any geometrical shape can be conceived. Absorption coefficient, reduced scattering coefficient and refractive index of the optical phantom have been measured to ensure that the optical parameters reasonably reproduce real human bone tissue in vivo. An experimental demonstration of a possible use of the optical phantom, utilizing a laser-Doppler flowmeter, is also presented.

  16. Bilateral maxillary sinus floor augmentation with tissue-engineered autologous osteoblasts and demineralized freeze-dried bone

    Directory of Open Access Journals (Sweden)

    Aashish Deshmukh

    2015-01-01

    Full Text Available The pneumatization of the maxillary sinus often results in a lack of sufficient alveolar bone for implant placement. In the last decades, maxillary sinus lift has become a very popular procedure with predictable results. Sinus floor augmentation procedures are generally carried out using autologous bone grafts, bone substitutes, or composites of bone and bone substitutes. However, the inherent limitations associated with each of these, have directed the attention of investigators to new technologies like bone tissue engineering. Bone marrow stromal cells have been regarded as multi-potent cells residing in bone marrow. These cells can be harvested from a person, multiplied outside his body using bioengineering principles and technologies and later introduced into a tissue defect. We present a case where tissue-engineered autologous osteoblasts were used along with demineralized freeze-dried bone for sinus floor augmentation.

  17. Effect of micromorphology of cortical bone tissue on crack propagation under dynamic loading

    Directory of Open Access Journals (Sweden)

    Wang Mayao

    2015-01-01

    Full Text Available Structural integrity of bone tissue plays an important role in daily activities of humans. However, traumatic incidents such as sports injuries, collisions and falls can cause bone fracture, servere pain and mobility loss. In addition, ageing and degenerative bone diseases such as osteoporosis can increase the risk of fracture [1]. As a composite-like material, a cortical bone tissue is capable of tolerating moderate fracture/cracks without complete failure. The key to this is its heterogeneously distributed microstructural constituents providing both intrinsic and extrinsic toughening mechanisms. At micro-scale level, cortical bone can be considered as a four-phase composite material consisting of osteons, Haversian canals, cement lines and interstitial matrix. These microstructural constituents can directly affect local distributions of stresses and strains, and, hence, crack initiation and propagation. Therefore, understanding the effect of micromorphology of cortical bone on crack initiation and propagation, especially under dynamic loading regimes is of great importance for fracture risk evaluation. In this study, random microstructures of a cortical bone tissue were modelled with finite elements for four groups: healthy (control, young age, osteoporosis and bisphosphonate-treated, based on osteonal morphometric parameters measured from microscopic images for these groups. The developed models were loaded under the same dynamic loading conditions, representing a direct impact incident, resulting in progressive crack propagation. An extended finite-element method (X-FEM was implemented to realize solution-dependent crack propagation within the microstructured cortical bone tissues. The obtained simulation results demonstrate significant differences due to micromorphology of cortical bone, in terms of crack propagation characteristics for different groups, with the young group showing highest fracture resistance and the senior group the

  18. Boron containing poly-(lactide-co-glycolide) (PLGA) scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Doğan, Ayşegül; Demirci, Selami [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University 34755 Istanbul (Turkey); Bayir, Yasin [Department of Biochemistry, Faculty of Pharmacy, Ataturk University, 25240, Erzurum (Turkey); Halici, Zekai [Department of Pharmacology, Faculty of Medicine, Ataturk University, 25240, Erzurum (Turkey); Karakus, Emre [Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Ataturk University, 25240, Erzurum (Turkey); Aydin, Ali [Department of Orthopedics and Traumatology, Faculty of Medicine, Ataturk University, 25240, Erzurum (Turkey); Cadirci, Elif [Department of Pharmacology, Faculty of Pharmacy, Ataturk University, 25240, Erzurum (Turkey); Albayrak, Abdulmecit [Department of Pharmacology, Faculty of Medicine, Ataturk University, 25240, Erzurum (Turkey); Demirci, Elif [Department of Pathology, Faculty of Medicine, Ataturk University, 25240, Erzurum (Turkey); Karaman, Adem [Department of Radiology, Faculty of Medicine, Ataturk University, 25240, Erzurum (Turkey); Ayan, Arif Kursat [Department of Nuclear Medicine, Faculty of Medicine, Ataturk University, 25240, Erzurum (Turkey); Gundogdu, Cemal [Department of Pathology, Faculty of Medicine, Ataturk University, 25240, Erzurum (Turkey); Şahin, Fikrettin, E-mail: fsahin@yeditepe.edu.tr [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University 34755 Istanbul (Turkey)

    2014-11-01

    Scaffold-based bone defect reconstructions still face many challenges due to their inadequate osteoinductive and osteoconductive properties. Various biocompatible and biodegradable scaffolds, combined with proper cell type and biochemical signal molecules, have attracted significant interest in hard tissue engineering approaches. In the present study, we have evaluated the effects of boron incorporation into poly-(lactide-co-glycolide-acid) (PLGA) scaffolds, with or without rat adipose-derived stem cells (rADSCs), on bone healing in vitro and in vivo. The results revealed that boron containing scaffolds increased in vitro proliferation, attachment and calcium mineralization of rADSCs. In addition, boron containing scaffold application resulted in increased bone regeneration by enhancing osteocalcin, VEGF and collagen type I protein levels in a femur defect model. Bone mineralization density (BMD) and computed tomography (CT) analysis proved that boron incorporated scaffold administration increased the healing rate of bone defects. Transplanting stem cells into boron containing scaffolds was found to further improve bone-related outcomes compared to control groups. Additional studies are highly warranted for the investigation of the mechanical properties of these scaffolds in order to address their potential use in clinics. The study proposes that boron serves as a promising innovative approach in manufacturing scaffold systems for functional bone tissue engineering. - Highlights: • Boron containing PLGA scaffolds were developed for bone tissue engineering. • Boron incorporation increased cell viability and mineralization of stem cells. • Boron containing scaffolds increased bone-related protein expression in vivo. • Implantation of stem cells on boron containing scaffolds improved bone healing.

  19. Enhancement of albumin expression in bone tissues with healing rat fractures.

    Science.gov (United States)

    Yamaguchi, Masayoshi; Igarashi, Aki; Misawa, Hiroyuki; Tsurusaki, Yoshinori

    2003-05-15

    The characterization of 66 kDa protein molecule, a major protein component which is produced from femoral-diaphyseal tissues with fracture healing (Igarashi and Yamaguchi [2002] Int. J. Mol. Med. 9:503-508), was investigated. Weaning rats were killed at 7 and 14 days after femoral fracture. When the femoral-diaphyseal tissues with fracture healing were cultured for 48 h in a serum-free medium, many proteins in the bone tissues were released into the medium. Analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that a protein molecule of approximately 66 kDa was markedly increased in culture medium from bone tissues with fracture healing. N-terminal sequencing of 66 kDa protein indicated that its N-terminus was identical to that of rat albumin. Western blot analysis of medium 66 kDa protein showed expression of albumin. This expression was significantly enhanced by fracture healing. The expression of albumin was seen in the diaphyseal (cortical bone) and metaphyseal (trabecular bone) tissues of rat femur. When the femoral-diaphyseal tissues obtained at 7 days after femoral fracture were cultured in a serum-free medium containing either vehicle, parathyroid hormone (1-34) (10(-7) M), insulin-like growth factor-I (10(-8) M) or zinc acexamate (10(-4) M), medium albumin was significantly increased in the presence of those bone-stimulating factors. The addition of albumin (0.5 or 1.0 mg/ml of medium) caused a significant increase in calcium and deoxyribonucleic acid contents in the femoral-diaphyseal and -metaphyseal tissues obtained from normal rats in vitro. The present study demonstrates that fracture healing induces a remarkable production of albumin which is a major protein component produced from femoral-diaphyseal tissues of rats, and that albumin has an anabolic effect on bone components.

  20. Mineralization of human bone tissue under hypokinesia and physical exercise with calcium supplements

    Science.gov (United States)

    Zorbas, Yan G.; Verentsov, Grigori E.; Abratov, Nikolai I.

    It has been suggested that physical exercise and calcium supplements may be used to prevent demineralization of bone tissue under hypokinesia (diminished muscular activity). Thus, the aim of this study was to determine mineral content of bones of 12 physically healthy men aged 19-24 years under 90 days of hypokinesia and intensive physical exercise (PE) with calcium lactate (C) supplements. They were divided into experimental and control groups with 6 men in each. The experimental group of men were subjected to hypokinesia (HK) and intensive PE and took 650 mg C 6 times per day; the control group was placed under pure HK, i.e. without the use of any preventive measures. The mineral content of different bone tissues was measured with a densitometric X-ray method in milligrams of calcium per 1 mm 3 before and after exposure to HK. The level of bone density of the examined bone tissues decreased by 7-9% and 5-7% for the control and experimental groups of men, respectively. A statistical analysis revealed that the reduction of bone mineralization was significant with P human organisms, since the entire animal kingdom had been formed in an environment of high motor activity which left its imprint on the evolution, structure, function and behaviour of animals and men. The impossibility of the body tissues to retain optimum amounts of fluid and electrolytes is the dominant hypokinetic effect.

  1. Low-intensity pulsed ultrasound prompts tissue-engineered bone formation after implantation surgery

    Institute of Scientific and Technical Information of China (English)

    Wang Juyong; Wang Juqiang; Asou Yoshinori; Paul Fu; Shen Huiliang; Chen Jiani; Sotome Shinichi

    2014-01-01

    Background A practical problem impeding clinical translation is the limited bone formation seen in artificial bone grafts.Low-pressure/vacuum seeding and dynamic culturing in bioreactors have led to a greater penetration into the scaffolds,enhanced production of bone marrow cells,and improved tissue-engineered bone formation.The goal of this study was to promote more extensive bone formation in the composites of porous ceramics and bone marrow stromal cells (BMSCs).Methods BMSCs/β-tricalcium phosphate (β-TCP) composites were subcultured for 2 weeks and then subcutaneously implanted into syngeneic rats that were split into a low-intensity pulsed ultrasound (LIPUS) treatment group and a control group.These implants were harvested at 5,10,25,and 50 days after implantation.The samples were then biomechanically tested and analyzed for alkaline phosphate (ALP) activity and osteocalcin (OCN) content and were also observed by light microscopy.Results The levels of ALP activity and OCN content in the composites were significantly higher in the LIPUS group than in the control group.Histomorphometric analysis revealed a greater degree of soft tissue repair,increased blood flow,better angiogenesis,and more extensive bone formation in the LIPUS groups than in the controls.No significant difference in the compressive strength was found between the two groups.Conclusion LIPUS treatment appears to enhance bone formation and angiogenesis in the BMSCs/β3-TCP composites.

  2. Biphasic calcium phosphate–casein bone graft fortified with Cassia occidentalis for bone tissue engineering and regeneration

    Indian Academy of Sciences (India)

    B Santhosh Kumar; T Hemalatha; R Deepachitra; R Narasimha Raghavan; P Prabu; T P Sastry

    2015-02-01

    Research on traditional herbs is gaining momentum owing to their potent medical properties, among which Cassia occidentalis (CO) is a promising herb, with osteogenic potential. The study investigates the efficacy of CO extract incorporated biphasic calcium phosphate as an osteoinductive material. Prepared bone implants were characterized physico-chemically using FT-IR, TGA, XRD, SEM and EDX. The implants were analysed further for mechanical and biological properties. The results revealed that CO extract-incorporated bone implants possessed better compression strength and it was able to induce proliferation and enhance alkaline phosphatase activity in SaOS-2 cells. The implant proves to be promising for bone tissue engineering, and hence it demands further in vivo evaluation.

  3. Monte Carlo modeling of photon transport in buried bone tissue layer for quantitative Raman spectroscopy

    Science.gov (United States)

    Wilson, Robert H.; Dooley, Kathryn A.; Morris, Michael D.; Mycek, Mary-Ann

    2009-02-01

    Light-scattering spectroscopy has the potential to provide information about bone composition via a fiber-optic probe placed on the skin. In order to design efficient probes, one must understand the effect of all tissue layers on photon transport. To quantitatively understand the effect of overlying tissue layers on the detected bone Raman signal, a layered Monte Carlo model was modified for Raman scattering. The model incorporated the absorption and scattering properties of three overlying tissue layers (dermis, subdermis, muscle), as well as the underlying bone tissue. The attenuation of the collected bone Raman signal, predominantly due to elastic light scattering in the overlying tissue layers, affected the carbonate/phosphate (C/P) ratio by increasing the standard deviation of the computational result. Furthermore, the mean C/P ratio varied when the relative thicknesses of the layers were varied and the elastic scattering coefficient at the Raman scattering wavelength of carbonate was modeled to be different from that at the Raman scattering wavelength of phosphate. These results represent the first portion of a computational study designed to predict optimal probe geometry and help to analyze detected signal for Raman scattering experiments involving bone.

  4. Optical detection of carotenoid antioxidants in human bone and surrounding tissue.

    Science.gov (United States)

    Ermakov, Igor V; Ermakova, Maia R; Rosenberg, Thomas D; Gellermann, Werner

    2013-11-01

    Carotenoids are known to play an important role in health and disease state of living human tissue based on their antioxidant and optical filtering functions. In this study, we show that carotenoids exist in human bone and surrounding fatty tissue both in significant and individually variable concentrations. Measurements of biopsied tissue samples with molecule-specific Raman spectroscopy and high-performance liquid chromatography reveal that all carotenoids that are known to exist in human skin are also present in human bone. This includes all carotenes, lycopene, β-cryptoxanthin, lutein, and zeaxanthin. We propose quantitative reflection imaging as a noncontact optical method suitable for the measurement of composite carotenoid levels in bone and surrounding tissue exposed during open surgeries such as total knee arthroplasty, and as a proof of concept, demonstrate carotenoid measurements in biopsied bone samples. This will allow one to establish potential correlations between internal tissue carotenoid levels and levels in skin and to potentially use already existing optical skin carotenoid tests as surrogate marker for bone carotenoid status.

  5. Determination of the relationship between collagen cross-links and the bone-tissue stiffness in the porcine mandibular condyle.

    Science.gov (United States)

    Willems, Nop M B K; Mulder, Lars; Bank, Ruud A; Grünheid, Thorsten; den Toonder, Jaap M J; Zentner, Andrej; Langenbach, Geerling E J

    2011-04-07

    Although bone-tissue stiffness is closely related to the degree to which bone has been mineralized, other determinants are yet to be identified. We, therefore, examined the extent to which the mineralization degree, collagen, and its cross-links are related to bone-tissue stiffness. A total of 50 cancellous and cortical bone samples were derived from the right mandibular condyles of five young and five adult female pigs. The degree of mineralization of bone (DMB) was assessed using micro-computed tomography. Using high-performance liquid chromatography, we quantified the collagen content and the number of cross-links per collagen molecule of two enzymatic cross-links: hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), and one non-enzymatic cross-link: pentosidine (Pen). Nanoindentation was used to assess bone-tissue stiffness in three directions, and multiple linear regressions were used to calculate the correlation between collagen properties and bone-tissue stiffness, with the DMB as first predictor. Whereas the bone-tissue stiffness of cancellous bone did not differ between the three directions of nanoindentation, or between the two age groups, cortical bone-tissue stiffness was higher in the adult tissue. After correction for DMB, the cross-links studied did not increase the explained variance. In the young group, however, LP significantly improved the explained variance in bone-tissue stiffness. Approximately half of the variation in bone-tissue stiffness in cancellous and cortical bone was explained by the DMB and the LP cross-links and thus they cannot be considered the sole determinants of the bone-tissue stiffness.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

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

  7. Ready to Use Tissue Construct for Military Bone & Cartilage Trauma

    Science.gov (United States)

    2014-10-01

    supplied cell- permeable green fluorescent dye (Ex/Em = 488/518 nm) and propidium iodide (PI), a cell non- permeable red fluorescent dye (Ex/Em = 488/615...fixation is commonly used for forearm bone fractures. For femur and tibia, intramedullary nailing is a common choice of internal fixation. For the...humerus, both plate and screws and intramedullary nailing are used. However, for skeletal defects following resection of malignant tumors, intramedullary

  8. Correlation Between Bone and Soft Tissue Thickness in Maxillary Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Nasrin Esfahanizadeh

    2016-12-01

    Full Text Available Objectives: The purpose of this study was to determine buccal bone and soft tissue thicknesses and their correlation in the maxillary anterior region using cone beam computed tomography (CBCT.Materials and Methods: In this cross sectional study, 330 sound maxillary incisors in 60 patients with a mean age of 37.5 years were assessed by CBCT scans. For better visualization of soft tissue, patients were asked to use plastic retractors in order to retract their lips and cheeks away from the gingival tissue before taking the scans. Measurements were made in three different positions: at the crest and at 2 and 5mm apical to the crest. The cementoenamel junction‒crest distance was measured. for data analyses, the Pearson’s correlation coefficient, ANOVA and intraclass correlation coefficient were used.Results: There were mildly significant linear associations between labial soft tissue and bone thickness in the canines and incisors (r<0.40, P<0.05, but no association was found for the lateral incisors. The mean thickness of buccal bone differed significantly in the maxillary anterior teeth, being greater for the lateral incisors (P<0.05. For soft tissue thickness, the results were the same, and the least thickness was recorded for the canines. There was a mild association between labial soft tissue and bone thickness in canines and incisors (r=0.2, P=0.3, but no such linear association was seen for the lateral incisors.Conclusions: The mean thickness of buccal bone and soft tissue in the anterior maxilla was <1mm and there was a mild linear correlation between them.Keywords: Facial Bones; Cone-Beam Computed Tomography; Maxilla; Esthetics, Dental

  9. Central and peripheral mechanisms of the NPY system in the regulation of bone and adipose tissue.

    Science.gov (United States)

    Shi, Yan-Chuan; Baldock, Paul A

    2012-02-01

    Skeletal research is currently undergoing a period of marked expansion. The boundaries of "bone" research are being re-evaluated and with this, a growing recognition of a more complex and interconnected biology than previously considered. One aspect that has become the focus of particular attention is the relationship between bone and fat homeostasis. Evidence from a number of avenues indicates that bone and adipose regulation are both related and interdependent. This review examines the neuropeptide Y (NPY) system, known to exert powerful control over both bone and fat tissue. The actions of this system are characterized by signaling both within specific nuclei of the hypothalamus and also the target tissues, mediated predominantly through two G-protein coupled receptors (Y1 and Y2). In bone tissue, elevated NPY levels act consistently to repress osteoblast activity. Moreover, both central Y2 receptor and osteoblastic Y1 receptor signaling act similarly to repress bone formation. Conversely, loss of NPY expression or receptor signaling induces increased osteoblast activity and bone mass in both cortical and cancellous envelopes. In fat tissue, NPY action is more complex. Energy homeostasis is powerfully altered by elevations in hypothalamic NPY, resulting in increases in fat accretion and body-wide energy conservation, through the action of locally expressed Y1 receptors, while local Y2 receptors act to inhibit NPY-ergic tone. Loss of central NPY expression has a markedly reduced effect, consistent with a physiological drive to promote fat accretion. In fat tissue, NPY and Y1 receptors act to promote lipogenesis, consistent with their roles in the brain. Y2 receptors expressed in adipocytes also act in this manner, showing an opposing action to their role in the hypothalamus. While direct investigation of these processes has yet to be completed, these responses appear to be interrelated to some degree. The starvation-based signal of elevated central NPY inducing

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

    Science.gov (United States)

    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.

  11. Augmentation of the rat jaw with autogeneic cortico-cancellous bone grafts and guided tissue regeneration.

    Science.gov (United States)

    Donos, Nikolaos; Kostopoulos, Lambros; Karring, Thorkild

    2002-04-01

    The aim of the present study was to evaluate the effect of augmenting the maxillary alveolar ridge and the lateral aspect of the mandible with onlay autogeneic cortico-cancellous bone grafts that were covered with e-PTFE membranes. The experiment was carried out in 51 rats. In 15 rats, the edentulous maxillary jaw between the incisor and the first molar was augmented by means of an autogeneic ischiac bone graft that was fixed with a gold-coated microimplant. In one side, the graft was covered with an e-PTFE membrane, while the other side, which served as control, was treated without a membrane. In the other 36 rats, the lateral aspect of the mandible was augmented in both sides by means of an autogeneic ischiac bone graft that was fixed with a gold-coated or a titanium microimplant. In one side, the augmented area was covered with an e-PTFE membrane, while the contralateral side was treated without a membrane. Histological analysis at 60, 120 and 180 days after augmentation of the maxilla showed that, in the case of the test sites (where most of the membranes were either exposed or lost), the bone grafts presented extensive resorption and there was a lack of bone continuity between the graft and the recipient site. Similar findings were made at the non-membrane-treated control sides. In the case of augmentation of the mandible with membranes, the bone grafts were not resorbed, but were integrated into newly formed bone at the recipient site. In the control sides, the grafts presented varying degrees of resorption and integration into the recipient bone. It is concluded that, in comparison to bone grafting alone, onlay ischiac bone grafting combined with guided tissue regeneration eliminates the risk of bone graft resorption and ensures integration of the graft into newly formed bone at the recipient site, provided that closure of the operated area can be maintained during healing.

  12. Immobilization and Application of Electrospun Nanofiber Scaffold-based Growth Factor in Bone Tissue Engineering.

    Science.gov (United States)

    Chen, Guobao; Lv, Yonggang

    2015-01-01

    Electrospun nanofibers have been extensively used in growth factor delivery and regenerative medicine due to many advantages including large surface area to volume ratio, high porosity, excellent loading capacity, ease of access and cost effectiveness. Their relatively large surface area is helpful for cell adhesion and growth factor loading, while storage and release of growth factor are essential to guide cellular behaviors and tissue formation and organization. In bone tissue engineering, growth factors are expected to transmit signals that stimulate cellular proliferation, migration, differentiation, metabolism, apoptosis and extracellular matrix (ECM) deposition. Bolus administration is not always an effective method for the delivery of growth factors because of their rapid diffusion from the target site and quick deactivation. Therefore, the integration of controlled release strategy within electrospun nanofibers can provide protection for growth factors against in vivo degradation, and can manipulate desired signal at an effective level with extended duration in local microenvironment to support tissue regeneration and repair which normally takes a much longer time. In this review, we provide an overview of growth factor delivery using biomimetic electrospun nanofiber scaffolds in bone tissue engineering. It begins with a brief introduction of different kinds of polymers that were used in electrospinning and their applications in bone tissue engineering. The review further focuses on the nanofiber-based growth factor delivery and summarizes the strategies of growth factors loading on the nanofiber scaffolds for bone tissue engineering applications. The perspectives on future challenges in this area are also pointed out.

  13. Experimental and numerical analysis of Izod impact test of cortical bone tissue

    Science.gov (United States)

    Abdel-Wahab, A. A.; Silberschmidt, V. V.

    2012-05-01

    Bones can only sustain loads until a certain limit, beyond which they fail. Usually, the reasons for bone fracture are traumatic falls, sports injuries, and engagement in transport or industrial accidents. A proper treatment of bones and prevention of their fracture can be supported by in-depth understanding of deformation and fracture behavior of this tissue in such dynamic events. In this paper, a combination of experimental and numerical analysis was carried out in order to comprehend the fracture behavior of cortical bone tissue. Experimental tests were performed to study the transient dynamic behavior of cortical bone tissue under impact bending loading. The variability of absorbed energy for different cortex positions and notch depths was studied using Izod impact tests. Also, Extended Finite-Element Method implemented into the commercial finite-element software Abaqus was used to simulate the crack initiation and growth processes in a cantilever beam of cortical bone exposed to impact loading using the Izod loading scheme. The simulation results show a good agreement with the experimental data.

  14. Fabrication of nanocrystalline hydroxyapatite doped degradable composite hollow fiber for guided and biomimetic bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ning [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Nichols, Heather L. [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Tylor, Shila [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Wen Xuejun [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States)]. E-mail: xjwen@clemson.edu

    2007-04-15

    Natural bone tissue possesses a nanocomposite structure interwoven in a three-dimensional (3-D) matrix, which plays critical roles in conferring appropriate physical and biological properties to the bone tissue. Single type of material may not be sufficient to mimic the composition, structure and properties of native bone, therefore, composite materials consisting of both polymers, bioceramics, and other inorganic materials have to be designed. Among a variety of candidate materials, polymer-nanoparticle composites appear most promising for bone tissue engineering applications because of superior mechanical properties, improved durability, and surface bioactivity when compared with conventional polymers or composites. The long term objective of this project is to use highly aligned, bioactive, biodegradable scaffold mimicking natural histological structure of human long bone, and to engineer and regenerate human long bone both in vitro and in vivo. In this study, bioactive, degradable, and highly permeable composite hollow fiber membranes (HFMs) were fabricated using a wet phase phase-inversion approach. The structure of the hollow fiber membranes was examined using scanning electron microscopy (SEM); degradation behavior was examined using weigh loss assay, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC); and bioactivity was evaluated with the amount of calcium deposition from the culture media onto HFM surface. Doping PLGA HFMs with nanoHA results in a more bioactive and slower degrading HFM than pure PLGA HFMs.

  15. Systemic drug delivery systems for bone tissue regeneration- a mini review.

    Science.gov (United States)

    Xinluan, Wang; Yuxiao, Lai; Helena, Ng HueiLeng; Zhijun, Yang; Ling, Qin

    2015-01-01

    Musculoskeletal metabolic diseases such as osteoporosis have become the major public health problems worldwide in our aging society. Pharmaceutical therapy is one of the approaches to prevent and treat related medical conditions. Most of the clinically used anti-osteoporotic drugs are administered systemically and have demonstrated some side effects in non-skeletal tissues. One of the innovative approaches to prevent potential adverse effects is the development of bone-targeting drug delivery technologies that not only minimizes the systemic toxicity but also improves the pharmacokinetic profile and therapeutic efficacy of chemical drugs. This paper reviews the currently available bone targeting drug delivery systems with emphasis as bone-targeting moieties, including the bonesurface- site-specific (bone formation dominant or bone resorption dominant) and cell-specific moieties. In addition, the connections of drug-bone-targeting moieties-carrier are also summarized, and the newly developed liposomes and nanoparticles are discussed for their potential use and main challenges in delivering therapeutic agents to bone tissue. As a rapid-developing biotechnology, systemic bonetargeting delivery system is promising but still in its infancy where challenges are ahead of us, including the stability and the toxicity issues, especially to fulfill the regulatory requirement to realize bench-to-bedside translation. Newly developed biomaterials and technologies with potential for safer and more effective drug delivery require multidisciplinary collaborations with preclinical and clinical scientists that are essential to facilitate their clinical applications.

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

    Science.gov (United States)

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

    2017-03-27

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

  17. Boron containing poly-(lactide-co-glycolide) (PLGA) scaffolds for bone tissue engineering.

    Science.gov (United States)

    Doğan, Ayşegül; Demirci, Selami; Bayir, Yasin; Halici, Zekai; Karakus, Emre; Aydin, Ali; Cadirci, Elif; Albayrak, Abdulmecit; Demirci, Elif; Karaman, Adem; Ayan, Arif Kursat; Gundogdu, Cemal; Sahin, Fikrettin

    2014-11-01

    Scaffold-based bone defect reconstructions still face many challenges due to their inadequate osteoinductive and osteoconductive properties. Various biocompatible and biodegradable scaffolds, combined with proper cell type and biochemical signal molecules, have attracted significant interest in hard tissue engineering approaches. In the present study, we have evaluated the effects of boron incorporation into poly-(lactide-co-glycolide-acid) (PLGA) scaffolds, with or without rat adipose-derived stem cells (rADSCs), on bone healing in vitro and in vivo. The results revealed that boron containing scaffolds increased in vitro proliferation, attachment and calcium mineralization of rADSCs. In addition, boron containing scaffold application resulted in increased bone regeneration by enhancing osteocalcin, VEGF and collagen type I protein levels in a femur defect model. Bone mineralization density (BMD) and computed tomography (CT) analysis proved that boron incorporated scaffold administration increased the healing rate of bone defects. Transplanting stem cells into boron containing scaffolds was found to further improve bone-related outcomes compared to control groups. Additional studies are highly warranted for the investigation of the mechanical properties of these scaffolds in order to address their potential use in clinics. The study proposes that boron serves as a promising innovative approach in manufacturing scaffold systems for functional bone tissue engineering.

  18. Ionic Colloidal Molding as a Biomimetic Scaffolding Strategy for Uniform Bone Tissue Regeneration.

    Science.gov (United States)

    Zhang, Jian; Jia, Jinpeng; Kim, Jimin P; Shen, Hong; Yang, Fei; Zhang, Qiang; Xu, Meng; Bi, Wenzhi; Wang, Xing; Yang, Jian; Wu, Decheng

    2017-02-21

    Inspired by the highly ordered nanostructure of bone, nanodopant composite biomaterials are gaining special attention for their ability to guide bone tissue regeneration through structural and biological cues. However, bone malformation in orthopedic surgery is a lingering issue, partly due to the high surface energy of traditional nanoparticles contributing to aggregation and inhomogeneity. Recently, carboxyl-functionalized synthetic polymers have been shown to mimic the carboxyl-rich surface motifs of non-collagenous proteins in stabilizing hydroxyapatite and directing intrafibrillar mineralization in-vitro. Based on this biomimetic approach, it is herein demonstrated that carboxyl functionalization of poly(lactic-co-glycolic acid) can achieve great material homogeneity in nanocomposites. This ionic colloidal molding method stabilizes hydroxyapatite precursors to confer even nanodopant packing, improving therapeutic outcomes in bone repair by remarkably improving mechanical properties of nanocomposites and optimizing controlled drug release, resulting in better cell in-growth and osteogenic differentiation. Lastly, better controlled biomaterial degradation significantly improved osteointegration, translating to highly regular bone formation with minimal fibrous tissue and increased bone density in rabbit radial defect models. Ionic colloidal molding is a simple yet effective approach of achieving materials homogeneity and modulating crystal nucleation, serving as an excellent biomimetic scaffolding strategy to rebuild natural bone integrity.

  19. 3D bone tissue growth in hollow fibre membrane bioreactor: implications of various process parameters on tissue nutrition.

    Science.gov (United States)

    Abdullah, N S; Das, D B; Ye, H; Cui, Z F

    2006-09-01

    New experimental evidence shows that hollow fibre membrane bioreactor (HFMB) may be applied to grow bulky bone tissues which may then be implanted into patients to repair skeletal defects. To design effective bone tissue engineering protocols, it is necessary to determine the quantitative relationships between the cell environment and tissue behaviour in HFMBs and their relationship with nutrient supply. It is also necessary to determine under what conditions nutritional limitations may occur and, hence, may cause cell death. These require that the appropriate bioreactor conditions for generating neotissues, and the nutrient transfer behaviour and chemical reaction during cell growth and extracellular matrix formation are studied thoroughly. In this paper, we aim to use an existing mathematical framework to analyse the influence of various relevant parameters on nutrient supply for bone tissue growth in HFMB. We adopt the well-known Krogh cylinder approximation of the HFMB. The model parameters (e.g., cell metabolic rates) and operating conditions for the mathematical model have been obtained from, or correspond to, in-house experiments with the exception of a few variables which have been taken from the literature. The framework is then used to study oxygen and glucose transport behaviour in the HFMB. Influence of a number of important process parameters, e.g., reaction kinetics, cell density, inlet concentration of nutrients, etc, on the nutrient distributions have been systematically analysed. The work presented in this paper provides insights on unfavourable system designs and specifications which may be avoided to prevent mass transfer limitations for growing bone tissues in HFMB.

  20. Reduced tissue hardness of trabecular bone is associated with severe osteoarthritis.

    Science.gov (United States)

    Dall'Ara, Enrico; Ohman, Caroline; Baleani, Massimiliano; Viceconti, Marco

    2011-05-17

    This study investigated whether changes in hardness of human trabecular bone are associated with osteoarthritis. Twenty femoral heads extracted from subjects without musculoskeletal diseases (subject age: 49-83 years) and twenty femoral heads extracted from osteoarthritic subjects (subject age: 42-85 years) were tested. Sixty indentations were performed along the main trabecular direction of each sample at a fixed relative distance. Two microstructures were found on the indenting locations: packs of parallel-lamellae (PL) and secondary osteons (SO). A 25gf load was applied for 15s and the Vickers Hardness (HV) was assessed. Trabecular tissue extracted from osteoarthritic subjects was found to be about 13% less hard compared to tissue extracted from non-pathologic subjects. However, tissue hardness was not significantly affected by gender or age. The SO was 10% less hard than the PL for both pathologic and non-pathologic tissues. A hardness of 34.1HV for PL and 30.8HV for SO was found for the non-pathologic tissue. For osteoarthritic tissue, the hardness was 30.2HV for PL and 27.1HV for SO. In the bone tissue extracted from osteoarthritic subjects the occurrence of indenting a SO (28%) was higher than that observed in the non-pathological tissue (15%). Osteoarthritis is associated with reduced tissue hardness and alterations in microstructure of the trabecular bone tissue. Gender does not significantly affect trabecular bone hardness either in non-pathological or osteoarthritic subjects. A similar conclusion can be drawn for age, although a larger donor sample size would be necessary to definitively exclude the existence of a slight effect.

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

    Science.gov (United States)

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

    2011-12-01

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

  2. Mechanical unloading of bone in microgravity reduces mesenchymal and hematopoietic stem cell-mediated tissue regeneration

    Directory of Open Access Journals (Sweden)

    E.A. Blaber

    2014-09-01

    Full Text Available Mechanical loading of mammalian tissues is a potent promoter of tissue growth and regeneration, whilst unloading in microgravity can cause reduced tissue regeneration, possibly through effects on stem cell tissue progenitors. To test the specific hypothesis that mechanical unloading alters differentiation of bone marrow mesenchymal and hematopoietic stem cell lineages, we studied cellular and molecular aspects of how bone marrow in the mouse proximal femur responds to unloading in microgravity. Trabecular and cortical endosteal bone surfaces in the femoral head underwent significant bone resorption in microgravity, enlarging the marrow cavity. Cells isolated from the femoral head marrow compartment showed significant down-regulation of gene expression markers for early mesenchymal and hematopoietic differentiation, including FUT1(−6.72, CSF2(−3.30, CD90(−3.33, PTPRC(−2.79, and GDF15(−2.45, but not stem cell markers, such as SOX2. At the cellular level, in situ histological analysis revealed decreased megakaryocyte numbers whilst erythrocytes were increased 2.33 fold. Furthermore, erythrocytes displayed elevated fucosylation and clustering adjacent to sinuses forming the marrow–blood barrier, possibly providing a mechanistic basis for explaining spaceflight anemia. Culture of isolated bone marrow cells immediately after microgravity exposure increased the marrow progenitor's potential for mesenchymal differentiation into in-vitro mineralized bone nodules, and hematopoietic differentiation into osteoclasts, suggesting an accumulation of undifferentiated progenitors during exposure to microgravity. These results support the idea that mechanical unloading of mammalian tissues in microgravity is a strong inhibitor of tissue growth and regeneration mechanisms, acting at the level of early mesenchymal and hematopoietic stem cell differentiation.

  3. Scaffolds for Growth Factor Delivery as Applied to Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Keith A. Blackwood

    2012-01-01

    Full Text Available There remains a substantial shortfall in the treatment of severe skeletal injuries. The current gold standard of autologous bone grafting from the same patient has many undesirable side effects associated such as donor site morbidity. Tissue engineering seeks to offer a solution to this problem. The primary requirements for tissue-engineered scaffolds have already been well established, and many materials, such as polyesters, present themselves as potential candidates for bone defects; they have comparable structural features, but they often lack the required osteoconductivity to promote adequate bone regeneration. By combining these materials with biological growth factors, which promote the infiltration of cells into the scaffold as well as the differentiation into the specific cell and tissue type, it is possible to increase the formation of new bone. However due to the cost and potential complications associated with growth factors, controlling the rate of release is an important design consideration when developing new bone tissue engineering strategies. This paper will cover recent research in the area of encapsulation and release of growth factors within a variety of different polymeric scaffolds.

  4. Paper-based bioactive scaffolds for stem cell-mediated bone tissue engineering.

    Science.gov (United States)

    Park, Hyun-Ji; Yu, Seung Jung; Yang, Kisuk; Jin, Yoonhee; Cho, Ann-Na; Kim, Jin; Lee, Bora; Yang, Hee Seok; Im, Sung Gap; Cho, Seung-Woo

    2014-12-01

    Bioactive, functional scaffolds are required to improve the regenerative potential of stem cells for tissue reconstruction and functional recovery of damaged tissues. Here, we report a paper-based bioactive scaffold platform for stem cell culture and transplantation for bone reconstruction. The paper scaffolds are surface-engineered by an initiated chemical vapor deposition process for serial coating of a water-repellent and cell-adhesive polymer film, which ensures the long-term stability in cell culture medium and induces efficient cell attachment. The prepared paper scaffolds are compatible with general stem cell culture and manipulation techniques. An optimal paper type is found to provide structural, physical, and mechanical cues to enhance the osteogenic differentiation of human adipose-derived stem cells (hADSCs). A bioactive paper scaffold significantly enhances in vivo bone regeneration of hADSCs in a critical-sized calvarial bone defect. Stacking the paper scaffolds with osteogenically differentiated hADSCs and human endothelial cells resulted in vascularized bone formation in vivo. Our study suggests that paper possesses great potential as a bioactive, functional, and cost-effective scaffold platform for stem cell-mediated bone tissue engineering. To the best of our knowledge, this is the first study reporting the feasibility of a paper material for stem cell application to repair tissue defects.

  5. 3D Tissue Scaffold Printing On Custom Artificial Bone Applications

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    Betül ALDEMİR

    2015-01-01

    Full Text Available Production of defect-matching scaffolds is the most critical step in custom artificial bone applications. Three dimensional printing (3DP is one of the best techniques particularly for custom designs on artificial bone applications because of the high controllability and design independency. Our long-term aim is to implant an artificial custom bone that is cultured with patient's own mesenchymal stem cells after determining defect architecture on patient's bone by using CT-scan and printing that defect-matching 3D scaffold with appropriate nontoxic materials. In this study, preliminary results of strength and cytotoxicity measurements of 3D printed scaffolds with modified calcium sulfate compositepowder (MCSCP were presented. CAD designs were created and MCSCP were printed by a 3D printer (3DS, Visijet, PXL Core. Some samples were covered with salt solution in order to harden the samples. MCSCP and salt coated MCSCP were the two experimental groups in this study. Cytotoxicity and mechanical experiments were performed after surface examination withscanning electron microscope (SEM and light microscope. Tension tests were performed for MCSCP and salt coated MCSCP samples. The 3D scaffolds were sterilized with ethylene oxide gas sterilizer, ventilated and conditioned with DMEM (10% FBS. L929 mouse fibroblast cells were cultured on scaffolds (3 repetitive and cell viability was determined using MTT analysis. According to the mechanical results, the MCSCP group stands until average 71,305 N, while salt coated MCSCP group stands until 21,328N. Although the strength difference between two groups is statistically significant (p=0.001, Mann-Whitney U, elastic modulus is not (MCSCP=1,186Pa, salt coated MCSCP=1,169Pa, p=0.445. Cell viability (MTT analysis results on day 1, 3, and 5 demonstrated thatscaffolds hadno toxic effect to the L929 mouse fibroblast cells. Consequently, 3D printed samples with MCSCP could potentially be a strong alternative

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

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    John G. Hardy

    2016-07-01

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

  7. Baculovirus as a gene delivery vector for cartilage and bone tissue engineering.

    Science.gov (United States)

    Lin, Chin-Yu; Lu, Chia-Hsin; Luo, Wen-Yi; Chang, Yu-Han; Sung, Li-Yu; Chiu, Hsin-Yi; Hu, Yu-Chen

    2010-06-01

    Baculovirus is an effective vector for gene delivery into various mammalian cells, including chondrocytes and mesenchymal stem cells, and has been employed for diverse applications. By gene delivery and expression of the growth factor, recombinant baculovirus has been shown to modulate the differentiation state of the cells and stimulates the production of extracellular matrix and tissue formation, hence repairing the damaged cartilage and bone in vivo. This article reviews the studies pertaining to the applications of baculovirus-mediated gene delivery in cartilage and bone tissue engineering and discusses recent progress, future applications and potential hurdles.

  8. In vivo cyclic loading as a potent stimulatory signal for bone formation inside tissue engineering scaffold

    Directory of Open Access Journals (Sweden)

    A Roshan-Ghias

    2010-02-01

    Full Text Available In clinical situations, bone defects are often located at load bearing sites. Tissue engineering scaffolds are future bone substitutes and hence they will be subjected to mechanical stimulation. The goal of this study was to test if cyclic loading can be used as stimulatory signal for bone formation in a bone scaffold. Poly(L-lactic acid (PLA/ 5% beta-tricalcium phosphate (beta-TCP scaffolds were implanted in both distal femoral epiphyses of eight rats. Right knees were stimulated (10N, 4Hz, 5 min five times, every two days, starting from the third day after surgery while left knees served as control. Finite element study of the in vivo model showed that the strain applied to the scaffold is similar to physiological strains. Using micro-computed tomography (CT, all knees were scanned five times after the surgery and the related bone parameters of the newly formed bone were quantified. Statistical modeling was used to estimate the evolution of these parameters as a function of time and loading. The results showed that mechanical stimulation had two effects on bone volume (BV: an initial decrease in BV at week 2, and a long-term increase in the rate of bone formation by 28%. At week 13, the BV was then significantly higher in the loaded scaffolds.

  9. Nanohydroxyapatite Effect on the Degradation, Osteoconduction and Mechanical Properties of Polymeric Bone Tissue Engineered Scaffolds

    Science.gov (United States)

    Salmasi, Shima; Nayyer, Leila; Seifalian, Alexander M.; Blunn, Gordon W.

    2016-01-01

    BACKGROUND Statistical reports show that every year around the world approximately 15 million bone fractures occur; of which up to 10% fail to heal completely and hence lead to complications of non-union healing. In the past, autografts or allografts were used as the “gold standard” of treating such defects. However, due to various limitations and risks associated with these sources of bone grafts, other avenues have been extensively investigated through which bone tissue engineering; in particular engineering of synthetic bone graft substitutes, has been recognised as a promising alternative to the traditional methods. METHODS A selective literature search was performed. RESULTS Bone tissue engineering offers unlimited supply, eliminated risk of disease transmission and relatively low cost. It could also lead to patient specific design and manufacture of implants, prosthesis and bone related devices. A potentially promising building block for a suitable scaffold is synthetic nanohydroxyapatite incorporated into synthetic polymers. Incorporation of nanohydroxyapatite into synthetic polymers has shown promising bioactivity, osteoconductivity, mechanical properties and degradation profile compared to other techniques previously considered. CONCLUSION Scientific research, through extensive physiochemical characterisation, in vitro and in vivo assessment has brought together the optimum characteristics of nanohydroxyapatite and various types of synthetic polymers in order to develop nanocomposites of suitable nature for bone tissue engineering. The aim of the present article is to review and update various aspects involved in incorporation of synthetic nanohydroxyapatite into synthetic polymers, in terms of their potentials to promote bone growth and regeneration in vitro, in vivo and consequently in clinical applications. PMID:28217213

  10. Prefabrication of axial vascularized tissue engineering coral bone by an arteriovenous loop: A better model

    Energy Technology Data Exchange (ETDEWEB)

    Dong Qingshan [Department of Oral and Maxillofacial Surgery, Wuhan General Hospital of Guangzhou Military Command, Wuhan 430070 (China); Shang Hongtao; Wu Wei [Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi' an 710032 (China); Chen Fulin [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, Xi' an 710069 (China); Zhang Junrui [Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi' an 710032 (China); Guo Jiaping [Department of Oral and Maxillofacial Surgery, Wuhan General Hospital of Guangzhou Military Command, Wuhan 430070 (China); Mao Tianqiu, E-mail: tianqiumao@126.com [Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi' an 710032 (China)

    2012-08-01

    The most important problem for the survival of thick 3-dimensional tissues is the lack of vascularization in the context of bone tissue engineering. In this study, a modified arteriovenous loop (AVL) was developed to prefabricate an axial vascularized tissue engineering coral bone in rabbit, with comparison of the arteriovenous bundle (AVB) model. An arteriovenous fistula between rabbit femoral artery and vein was anastomosed to form an AVL. It was placed in a circular side groove of the coral block. The complex was wrapped with an expanded-polytetrafluoroethylene membrane and implanted beneath inguinal skin. After 2, 4, 6 and 8 weeks, the degree of vascularization was evaluated by India ink perfusion, histological examination, vascular casts, and scanning electron microscopy images of vascular endangium. Newly formed fibrous tissues and vasculature extended over the surfaces and invaded the interspaces of entire coral block. The new blood vessels robustly sprouted from the AVL. Those invaginated cavities in the vascular endangium from scanning electron microscopy indicated vessel's sprouted pores. Above indexes in AVL model are all superior to that in AVB model, indicating that the modified AVL model could more effectively develop vascularization in larger tissue engineering bone. - Highlights: Black-Right-Pointing-Pointer A modified arteriovenous loop (AVL) model in rabbit was developed in this study. Black-Right-Pointing-Pointer Axial prevascularization was induced in a larger coral block by using the AVL. Black-Right-Pointing-Pointer The prefabrication of axial vascularized coral bone is superior as vascular carrier.

  11. Can Bone Tissue Engineering Contribute to Therapy Concepts after Resection of Musculoskeletal Sarcoma?

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    Boris Michael Holzapfel

    2013-01-01

    Full Text Available Resection of musculoskeletal sarcoma can result in large bone defects where regeneration is needed in a quantity far beyond the normal potential of self-healing. In many cases, these defects exhibit a limited intrinsic regenerative potential due to an adjuvant therapeutic regimen, seroma, or infection. Therefore, reconstruction of these defects is still one of the most demanding procedures in orthopaedic surgery. The constraints of common treatment strategies have triggered a need for new therapeutic concepts to design and engineer unparalleled structural and functioning bone grafts. To satisfy the need for long-term repair and good clinical outcome, a paradigm shift is needed from methods to replace tissues with inert medical devices to more biological approaches that focus on the repair and reconstruction of tissue structure and function. It is within this context that the field of bone tissue engineering can offer solutions to be implemented into surgical therapy concepts after resection of bone and soft tissue sarcoma. In this paper we will discuss the implementation of tissue engineering concepts into the clinical field of orthopaedic oncology.

  12. Repair of segmental bone defect using Totally Vitalized tissue engineered bone graft by a combined perfusion seeding and culture system.

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    Lin Wang

    Full Text Available BACKGROUND: The basic strategy to construct tissue engineered bone graft (TEBG is to combine osteoblastic cells with three dimensional (3D scaffold. Based on this strategy, we proposed the "Totally Vitalized TEBG" (TV-TEBG which was characterized by abundant and homogenously distributed cells with enhanced cell proliferation and differentiation and further investigated its biological performance in repairing segmental bone defect. METHODS: In this study, we constructed the TV-TEBG with the combination of customized flow perfusion seeding/culture system and β-tricalcium phosphate (β-TCP scaffold fabricated by Rapid Prototyping (RP technique. We systemically compared three kinds of TEBG constructed by perfusion seeding and perfusion culture (PSPC method, static seeding and perfusion culture (SSPC method, and static seeding and static culture (SSSC method for their in vitro performance and bone defect healing efficacy with a rabbit model. RESULTS: Our study has demonstrated that TEBG constructed by PSPC method exhibited better biological properties with higher daily D-glucose consumption, increased cell proliferation and differentiation, and better cell distribution, indicating the successful construction of TV-TEBG. After implanted into rabbit radius defects for 12 weeks, PSPC group exerted higher X-ray score close to autograft, much greater mechanical property evidenced by the biomechanical testing and significantly higher new bone formation as shown by histological analysis compared with the other two groups, and eventually obtained favorable healing efficacy of the segmental bone defect that was the closest to autograft transplantation. CONCLUSION: This study demonstrated the feasibility of TV-TEBG construction with combination of perfusion seeding, perfusion culture and RP technique which exerted excellent biological properties. The application of TV-TEBG may become a preferred candidate for segmental bone defect repair in orthopedic and

  13. Effect of coating Straumann Bone Ceramic with Emdogain on mesenchymal stromal cell hard tissue formation.

    Science.gov (United States)

    Mrozik, Krzysztof Marek; Gronthos, Stan; Menicanin, Danijela; Marino, Victor; Bartold, P Mark

    2012-06-01

    Periodontal tissue engineering requires a suitable biocompatible scaffold, cells with regenerative capacity, and instructional molecules. In this study, we investigated the capacity of Straumann Bone Ceramic coated with Straumann Emdogain, a clinical preparation of enamel matrix protein (EMP), to aid in hard tissue formation by post-natal mesenchymal stromal cells (MSCs) including bone marrow stromal cells (BMSCs) and periodontal ligament fibroblasts (PDLFs). MSCs were isolated and ex vivo-expanded from human bone marrow and periodontal ligament and, in culture, allowed to attach to Bone Ceramic in the presence or absence of Emdogain. Gene expression of bone-related proteins was investigated by real time RT-PCR for 72 h, and ectopic bone formation was assessed histologically in subcutaneous implants of Bone Ceramic containing MSCs with or without Emdogain in NOD/SCID mice. Alkaline phosphatase activity was also assessed in vitro, in the presence or absence of Emdogain. Collagen-I mRNA was up-regulated in both MSC populations over the 72-h time course with Emdogain. Expression of BMP-2 and the osteogenic transcription factor Cbfa-1 showed early stimulation in both MSC types after 24 h. In contrast, expression of BMP-4 was consistently down-regulated in both MSC types with Emdogain. Up-regulation of osteopontin and periostin mRNA was restricted to BMSCs, while higher levels of bone sialoprotein-II were observed in PDLFs with Emdogain. Furthermore, alkaline phosphatase activity levels were reduced in both BMSCs and PDLFs in the presence of Emdogain. Very little evidence was found for ectopic bone formation following subcutaneous implantation of MSCs with Emdogain-coated or -uncoated Bone Ceramic in NOD/SCID mice. The early up-regulation of several important bone-related genes suggests that Emdogain may have a significant stimulatory effect in the commitment of mesenchymal cells to osteogenic differentiation in vitro. While Emdogain inhibited AP activity and appeared

  14. Effect of Combined Calcium Hydroxide and Accelerated Portland Cement on Bone Formation and Soft Tissue Healing in Dog Bone Lesions

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    Khorshidi H

    2015-09-01

    Full Text Available Statement of Problem: Recent literatures show that accelerated Portland cement (APC and calcium hydroxide Ca (OH2 may have the potential to promote the bone regeneration. However, certain clinical studies reveal consistency of Ca (OH2, as one of the practical drawbacks of the material when used alone. To overcome such inconvenience, the combination of the Ca (OH2 with a bone replacement material could offer a convenient solution. Objectives: To evaluate the soft tissue healing and bone regeneration in the periodontal intrabony osseous defects using accelerated Portland cement (APC in combination with calcium hydroxide Ca (OH2, as a filling material. Materials and Methods: Five healthy adult mongrel dogs aged 2-3 years old (approximately 20 kg in weight with intact dentition and healthy periodontium were selected for this study. Two one-wall defects in both mesial and distal aspects of the 3rd premolars of both sides of the mandible were created. Therefore, four defects were prepared in each dog. Three defects in each dog were randomly filled with one of the following materials: APC alone, APC mixed with Ca (OH2, and Ca (OH2 alone. The fourth defect was left empty (control. Upon clinical examination of the sutured sites, the amount of dehiscence from the adjacent tooth was measured after two and eight weeks, using a periodontal probe mesiodistally. For histometric analysis, the degree of new bone formation was estimated at the end of the eighth postoperative week, by a differential point-counting method. The percentage of the defect volume occupied by new osteoid or trabecular bone was recorded. Results: Measurement of wound dehiscence during the second week revealed that all five APCs had an exposure of 1-2 mm and at the end of the study all samples showed 3-4 mm exposure across the surface of the graft material, whereas the Ca (OH2, control, and APC + Ca (OH2 groups did not show any exposure at the end of the eighth week of the study. The most

  15. Interactions between inorganic and organic phases in bone tissue as a source of inspiration for design of novel nanocomposites

    NARCIS (Netherlands)

    Farbod, K.; Nejadnik, M.R.; Jansen, J.A.; Leeuwenburgh, S.C.G.

    2014-01-01

    Mimicking the nanostructure of bone and understanding the interactions between the nanoscale inorganic and organic components of the extracellular bone matrix are crucial for the design of biomaterials with structural properties and a functionality similar to the natural bone tissue. Generally, thes

  16. Assessment of bone tissue during treatment dentoalveolar anomalies in children with scoliosis

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    Samoilenko A.V.

    2012-01-01

    Full Text Available The purpose of the study was to develop a rational method of treatment dentoalveolar anomalies aimed at reducing relapses dentoalveolar anomalies, duration of treatment, depending on bone density in patients with scoliosis. Scoliosis is often associated with osteopenia and impaired metabolism of connective tissue that manifested reduced bone mineral density and changes in metabolic status, impaired synthesis of the major structural components of connective tissue, resulting integral reaction to a combination of two abnormal situations - osteopenia and scoliotic deformity. Prevalence dentoalveolar anomalies abnormalities among patients with scoliosis reaches 81.6%, in most cases accompanied by gingivitis. Therefore, the need for orthodontic treatment in these patients is quite high. When scoliosis orthodontic treatment has an impact on pathologically changed bone, so the retention period of orthodontic treatment need prescriptions that enhance the adaptive capacity of the body and promote reparative bone formation and development of pathogenetically substantiated complex preventive measures aimed at improving the effectiveness of treatment and prevention of dentoalveolar anomalies recurrence. A biometric study of control and diagnostic models of the jaws, biochemical oral fluid, determining bone density by ultrasonic osteography, the timing of orthodontic treatment in patients, with jaw abnormalities suffering from scoliosis and various sites of varying severity. We have developed medical centers showed high efficiency, which showed an increase density and improve bone metabolism.

  17. Long bone defect models for tissue engineering applications: criteria for choice.

    Science.gov (United States)

    Horner, Elizabeth A; Kirkham, Jennifer; Wood, David; Curran, Stephen; Smith, Mark; Thomson, Brian; Yang, Xuebin B

    2010-04-01

    The replacement and repair of bone lost due to trauma, cancer, or congenital defects is a major clinical challenge. Skeletal tissue engineering is a potentially powerful strategy in modern regenerative medicine, and research in this field has increased greatly in recent years. Tissue engineering strategies seek to translate research findings in the fields of materials science, stem cell biology, and biomineralization into clinical applications, demanding the use of appropriate in vivo models to investigate bone regeneration of the long bone. However, identification of the optimal in vivo segmental bone defect model from the literature is difficult due to the use of different animal species (large and small mammals), different bones (weight-bearing and nonweight bearing), and multiple protocols, including the use of various scaffolds, cells, and bioactives. The aim of this review is to summarize the available animal models for evaluating long bone regeneration in vivo. We highlight the differences not only in species and sites but also in defect size, means of defect creation, duration of study, and fixation method. A critical evaluation of the most clinically relevant models is addressed to guide the researcher in his/her choice of the most appropriate model to use in future hypothesis-driven investigations.

  18. A mathematical model for bone tissue regeneration inside a specific type of scaffold.

    Science.gov (United States)

    Sanz-Herrera, J A; Garcia-Aznar, J M; Doblare, M

    2008-10-01

    Bone tissue regeneration using scaffolds is receiving an increasing interest in orthopedic surgery and tissue engineering applications. In this study, we present the geometrical characterization of a specific family of scaffolds based on a face cubic centered (FCC) arrangement of empty pores leading to analytical formulae of porosity and specific surface. The effective behavior of those scaffolds, in terms of mechanical properties and permeability, is evaluated through the asymptotic homogenization theory applied to a representative volume element identified with the unit cell FCC. Bone growth into the scaffold is estimated by means of a phenomenological model that considers a macroscopic effective stress as the mechanical stimulus that regulates bone formation. Cell migration within the scaffold is modeled as a diffusion process based on Fick's law which allows us to estimate the cell invasion into the scaffold microstructure. The proposed model considers that bone growth velocity is proportional to the concentration of cells and regulated by the mechanical stimulus. This model allows us to explore what happens within the scaffold, the surrounding bone and their interaction. The mathematical model has been numerically implemented and qualitatively compared with previous experimental results found in the literature for a scaffold implanted in the femoral condyle of a rabbit. Specifically, the model predicts around 19 and 23% of bone regeneration for non-grafted and grafted scaffolds, respectively, both with an initial porosity of 76%.

  19. Microfibril orientation dominates the microelastic properties of human bone tissue at the lamellar length scale.

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    Mathilde Granke

    Full Text Available The elastic properties of bone tissue determine the biomechanical behavior of bone at the organ level. It is now widely accepted that the nanoscale structure of bone plays an important role to determine the elastic properties at the tissue level. Hence, in addition to the mineral density, the structure and organization of the mineral nanoparticles and of the collagen microfibrils appear as potential key factors governing the elasticity. Many studies exist on the role of the organization of collagen microfibril and mineral nanocrystals in strongly remodeled bone. However, there is no direct experimental proof to support the theoretical calculations. Here, we provide such evidence through a novel approach combining several high resolution imaging techniques: scanning acoustic microscopy, quantitative scanning small-Angle X-ray scattering imaging and synchrotron radiation computed microtomography. We find that the periodic modulations of elasticity across osteonal bone are essentially determined by the orientation of the mineral nanoparticles and to a lesser extent only by the particle size and density. Based on the strong correlation between the orientation of the mineral nanoparticles and the collagen molecules, we conclude that the microfibril orientation is the main determinant of the observed undulations of microelastic properties in regions of constant mineralization in osteonal lamellar bone. This multimodal approach could be applied to a much broader range of fibrous biological materials for the purpose of biomimetic technologies.

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

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    Wilairat Leeanansaksiri

    2013-01-01

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

  1. Comparison of the relationship between bone marrow adipose tissue and volumetric bone mineral density in children and adults.

    Science.gov (United States)

    Shen, Wei; Velasquez, Gilbert; Chen, Jun; Jin, Ye; Heymsfield, Steven B; Gallagher, Dympna; Pi-Sunyer, F Xavier

    2014-01-01

    Several large-scale studies have reported the presence of an inverse relationship between bone mineral density (BMD) and bone marrow adipose tissue (BMAT) in adults. We aim to determine if there is an inverse relationship between pelvic volumetric BMD (vBMD) and pelvic BMAT in children and to compare this relationship in children and adults. Pelvic BMAT and bone volume (BV) was evaluated in 181 healthy children (5-17yr) and 495 healthy adults (≥18yr) with whole-body magnetic resonance imaging (MRI). Pelvic vBMD was calculated using whole-body dual-energy X-ray absorptiometry to measure pelvic bone mineral content and MRI-measured BV. An inverse correlation was found between pelvic BMAT and pelvic vBMD in both children (r=-0.374, pBMAT as the independent variable, being a child or adult neither significantly contribute to the pelvic BMD (p=0.995) nor did its interaction with pelvic BMAT (p=0.415). The inverse relationship observed between pelvic vBMD and pelvic BMAT in children extends previous findings that found the inverse relationship to exist in adults and provides further support for a reciprocal relationship between adipocytes and osteoblasts.

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

    Directory of Open Access Journals (Sweden)

    Roberto Carretta

    2015-01-01

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

  3. Development of bioactive porous α-TCP/HAp beads for bone tissue engineering.

    Science.gov (United States)

    Asaoka, Teruo; Ohtake, Shoji; Furukawa, Katsuko S; Tamura, Akito; Ushida, Takashi

    2013-11-01

    Porous beads of bioactive ceramics such as hydroxyapatite (HAp) and tribasic calcium phosphate (TCP) are considered a promising scaffold for cultivating bone cells. To realize this, α-TCP/HAp functionally graded porous beads are fabricated with two main purposes: to maintain the function of the scaffold with sufficient strength up to the growth of new bone, and is absorbed completely after the growth. HAp is a bioactive material that has both high strength and strong tissue-adhesive properties, but is not readily absorbed by the human body. On the contrary, α-TCP is highly bioabsorbable, resulting in a scaffold that is absorbed before it is completely replaced by bone. In this study, we produced porous, bead-shaped carriers as scaffolds for osteoblast culture. To control the solubility in vivo, the fabricated beads contained α-TCP at the center and HAp at the surface. Cell adaptability of these beads for bone tissue engineering was confirmed in vitro. It was found that α-TCP/HAp bead carriers exhibit low toxicity in the initial stages of cell seeding and cell adhesion. The presence of HAp in the composite bead form effectively increased ALP activity. In conclusion, it is suggested that these newly developed α-TCP/HAp beads are a promising tool for bone tissue engineering.

  4. Prevalence, extension and characteristics of fluid-fluid levels in bone and soft tissue tumors

    Energy Technology Data Exchange (ETDEWEB)

    Dyck, P. van; Venstermans, C.; Gielen, J.; Parizel, P.M. [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); Vanhoenacker, F.M. [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); AZ St-Maarten, Department of Radiology, Duffel/Mechelen (Belgium); Vogel, J. [Leiden University Medical Centre, Department of Orthopedics, Leiden (Netherlands); Kroon, H.M.; Bloem, J.L. [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Schepper, A.M.A. de [University Hospital Antwerp, Department of Radiology, Edegem (Belgium); Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands)

    2006-12-15

    The purpose of this study was to determine the prevalence, extension and signal characteristics of fluid-fluid levels in a large series of 700 bone and 700 soft tissue tumors. Out of a multi-institutional database, MRI of 700 consecutive patients with a bone tumor and MRI of 700 consecutive patients with a soft tissue neoplasm were retrospectively reviewed for the presence of fluid-fluid levels. Extension (single, multiple and proportion of the lesion occupied by fluid-fluid levels) and signal characteristics on magnetic resonance imaging of fluid-fluid levels were determined. In all patients, pathologic correlation was available. Of 700 patients with a bone tumor, 19 (10 male and 9 female; mean age, 29 years) presented with a fluid-fluid level (prevalence 2.7%). Multiple fluid-fluid levels occupying at least one half of the total volume of the lesion were found in the majority of patients. Diagnoses included aneurysmal bone cyst (ten cases), fibrous dysplasia (two cases), osteoblastoma (one case), simple bone cyst (one case), telangiectatic osteosarcoma (one case), ''brown tumor'' (one case), chondroblastoma (one case) and giant cell tumor (two cases). Of 700 patients with a soft tissue tumor, 20 (9 males and 11 females; mean age, 34 years) presented with a fluid-fluid level (prevalence 2.9%). Multiple fluid-fluid levels occupying at least one half of the total volume of the lesion were found in the majority of patients. Diagnoses included cavernous hemangioma (12 cases), synovial sarcoma (3 cases), angiosarcoma (1 case), aneurysmal bone cyst of soft tissue (1 case), myxofibrosarcoma (1 case) and high-grade sarcoma ''not otherwise specified'' (2 cases). In our series, the largest reported in the literature to the best of our knowledge, the presence of fluid-fluid levels is a rare finding with a prevalence of 2.7 and 2.9% in bone and soft tissue tumors, respectively. Fluid-fluid levels remain a non-specific finding and can

  5. Production and characterization of chitosan/gelatin/β-TCP scaffolds for improved bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Serra, I.R.; Fradique, R.; Vallejo, M.C.S.; Correia, T.R.; Miguel, S.P.; Correia, I.J., E-mail: icorreia@ubi.pt

    2015-10-01

    Recently, bone tissue engineering emerged as a viable therapeutic alternative, comprising bone implants and new personalized scaffolds to be used in bone replacement and regeneration. In this study, biocompatible scaffolds were produced by freeze-drying, using different formulations (chitosan, chitosan/gelatin, chitosan/β-TCP and chitosan/gelatin/β-TCP) to be used as temporary templates during bone tissue regeneration. Sample characterization was performed through attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Mechanical characterization and porosity analysis were performed through uniaxial compression test and liquid displacement method, respectively. In vitro studies were also done to evaluate the biomineralization activity and the cytotoxic profile of the scaffolds. Scanning electron and confocal microscopy analysis were used to study cell adhesion and proliferation at the scaffold surface and within their structure. Moreover, the antibacterial activity of the scaffolds was also evaluated through the agar diffusion method. Overall, the results obtained revealed that the produced scaffolds are bioactive and biocompatible, allow cell internalization and show antimicrobial activity against Staphylococcus aureus. Such, make these 3D structures as potential candidates for being used on the bone tissue regeneration, since they promote cell adhesion and proliferation and also prevent biofilm development at their surfaces, which is usually the main cause of implant failure. - Highlights: • Production of 3D scaffolds composed by chitosan/gelatin/β-TCP by freeze-drying for bone regeneration • Physicochemical characterization of the bone substitutes by SEM, FTIR, XRD and EDS • Evaluation of the cytotoxic profile and antibacterial activity of the 3D structures through in vitro assays.

  6. Combining technologies to create bioactive hybrid scaffolds for bone tissue engineering

    NARCIS (Netherlands)

    Nandakumar, A.; Barradas, A.M.C.; Boer, de J.; Moroni, L.; Blitterswijk, van C.A.; Habibovic, P.

    2013-01-01

    Combining technologies to engineer scaffolds that can offer physical and chemical cues to cells is an attractive approach in tissue engineering and regenerative medicine. In this study, we have fabricated polymer-ceramic hybrid scaffolds for bone regeneration by combining rapid prototyping (RP), ele

  7. Raloxifene microsphere-embedded collagen/chitosan/β-tricalcium phosphate scaffold for effective bone tissue engineering.

    Science.gov (United States)

    Zhang, Ming-Lei; Cheng, Ji; Xiao, Ye-Chen; Yin, Ruo-Feng; Feng, Xu

    2017-02-25

    Engineering novel scaffolds that can mimic the functional extracellular matrix (ECM) would be a great achievement in bone tissue engineering. This paper reports the fabrication of novel collagen/chitosan/β-tricalcium phosphate (CCTP) based tissue engineering scaffold. In order to improve the regeneration ability of scaffold, we have embedded raloxifene (RLX)-loaded PLGA microsphere in the CCTP scaffold. The average pore of scaffold was in the range of 150-200μm with ideal mechanical strength and swelling/degradation characteristics. The release rate of RLX from the microsphere (MS) embedded scaffold was gradual and controlled. Also a significantly enhanced cell proliferation was observed in RLX-MS exposed cell group suggesting that microsphere/scaffold could be an ideal biomaterial for bone tissue engineering. Specifically, RLX-MS showed a significantly higher Alizarin red staining indicating the higher mineralization capacity of this group. Furthermore, a high alkaline phosphatase (ALP) activity for RLX-MS exposed group after 15days incubation indicates the bone regeneration capacity of MC3T3-E1 cells. Overall, present study showed that RLX-loaded microsphere embedded scaffold has the promising potential for bone tissue engineering applications.

  8. [Use of mesenchymal stem cells for reparative processes activation in bone jaw tissue in experimental conditions].

    Science.gov (United States)

    Volozhin, A I; Vasil'ev, A Iu; Malyginov, N N; Bulanova, I M; Grigor''ian, A S; Kiseleva, E V; Cherniaev, S E; Tarasenko, I V

    2010-01-01

    In experiment on 12 Chinchilla rabbits dynamics of reparative regeneration was studied at the terms 2 and 4 months. Bone defect in mandible corner was closed by osteoplastic material Gapkol which was covered from inside by allogenic or autologic stem cells received from rabbit adipose tissue. The results of the ray tracing methods of study were verified by SEM and histological methods.

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

    Science.gov (United States)

    Idowu, Bernadine; Cama, Giuseppe; Deb, Sanjukta; Di Silvio, Lucy

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Bernadine Idowu

    2014-05-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  12. Radioisotopic methods for the study of bone sarcoma and soft tissue neoplasms

    Energy Technology Data Exchange (ETDEWEB)

    Gongora, R.

    1988-01-01

    Radioisotopic methods are widely applied to investigations of bone sarcoma and soft tissue neoplasms. We have at our disposal molecules with osseous, tumoral or vascular tropism. Their use, as single agents or combination, is helpful in positive and differential diagnosis and provides nosological informations. They are also useful in treatment monitoring and in long-term follow-up.

  13. Biological evaluation of porous aliphatic polyurethane/hydroxyapatite composite scaffolds for bone tissue engineering.

    NARCIS (Netherlands)

    Yang, W; Both, S.K.; Zuo, Y.; Birgani, Z.T.; Habibovic, P.; Li, Y.; Jansen, J.A.; Yang, F.

    2015-01-01

    Biomaterial scaffolds meant to function as supporting structures to osteogenic cells play a pivotal role in bone tissue engineering. Recently, we synthesized an aliphatic polyurethane (PU) scaffold via a foaming method using non-toxic components. Through this procedure a uniform interconnected porou

  14. Adipose mesenchymal stem cells in the field of bone tissue engineering.

    Science.gov (United States)

    Romagnoli, Cecilia; Brandi, Maria Luisa

    2014-04-26

    Bone tissue engineering represents one of the most challenging emergent fields for scientists and clinicians. Current failures of autografts and allografts in many pathological conditions have prompted researchers to find new biomaterials able to promote bone repair or regeneration with specific characteristics of biocompatibility, biodegradability and osteoinductivity. Recent advancements for tissue regeneration in bone defects have occurred by following the diamond concept and combining the use of growth factors and mesenchymal stem cells (MSCs). In particular, a more abundant and easily accessible source of MSCs was recently discovered in adipose tissue. These adipose stem cells (ASCs) can be obtained in large quantities with little donor site morbidity or patient discomfort, in contrast to the invasive and painful isolation of bone marrow MSCs. The osteogenic potential of ASCs on scaffolds has been examined in cell cultures and animal models, with only a few cases reporting the use of ASCs for successful reconstruction or accelerated healing of defects of the skull and jaw in patients. Although these reports extend our limited knowledge concerning the use of ASCs for osseous tissue repair and regeneration, the lack of standardization in applied techniques makes the comparison between studies difficult. Additional clinical trials are needed to assess ASC therapy and address potential ethical and safety concerns, which must be resolved to permit application in regenerative medicine.

  15. Concise review: cell-based strategies in bone tissue engineering and regenerative medicine

    NARCIS (Netherlands)

    Ma, J.; Both, S.K.; Yang, F.; Cui, F.Z.; Pan, J.; Meijer, G.J.; Jansen, J.A.; Beucken, J.J.J.P van den

    2014-01-01

    Cellular strategies play an important role in bone tissue engineering and regenerative medicine (BTE/RM). Variability in cell culture procedures (e.g., cell types, cell isolation and expansion, cell seeding methods, and preculture conditions before in vivo implantation) may influence experimental ou

  16. Porous crosslinked poly(e-caprolactone fumarate)/nanohydroxyapatite composites for bone tissue engineering

    NARCIS (Netherlands)

    Farokhi, M.; Sharifi, S.; Shafieyan, Y.; Bagher, Z.; Mottaghitalab, F.; Hatampoor, A.; Imani, M.; Shokrgozar, M. A.

    2012-01-01

    Porous nanocomposites based on poly(e-caprolactone fumarate) (PCLF) resin matrix; N-vinyl pyrrolidone (NVP) as a reactive diluents and nanohydroxyapatite (nHA) filler were developed for bone tissue engineering applications. Nanocomposite scaffolds with three different contents of nHA [5, 10, and 20

  17. Tissue-engineered mandibular bone reconstruction for continuity defects: a systematic approach to the literature

    NARCIS (Netherlands)

    Chanchareonsook, N.; Junker, R.; Jongpaiboonkit, L.; Jansen, J.A.

    2014-01-01

    Background: Despite significant surgical advances over the last decades, segmental mandibular bone repair remains a challenge. In light of this, tissue engineering might offer a next step in the evolution of mandibular reconstruction. Purpose: The purpose of the present report was to (1) systematica

  18. Bioactive polymeric–ceramic hybrid 3D scaffold for application in bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Torres, A.L.; Gaspar, V.M.; Serra, I.R.; Diogo, G.S.; Fradique, R. [CICS-UBI — Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã (Portugal); Silva, A.P. [CAST-UBI — Centre for Aerospace Science and Technologies, University of Beira Interior, Calçada Fonte do Lameiro, 6201-001 Covilhã (Portugal); Correia, I.J., E-mail: icorreia@ubi.pt [CICS-UBI — Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã (Portugal)

    2013-10-01

    The regeneration of large bone defects remains a challenging scenario from a therapeutic point of view. In fact, the currently available bone substitutes are often limited by poor tissue integration and severe host inflammatory responses, which eventually lead to surgical removal. In an attempt to address these issues, herein we evaluated the importance of alginate incorporation in the production of improved and tunable β-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) three-dimensional (3D) porous scaffolds to be used as temporary templates for bone regeneration. Different bioceramic combinations were tested in order to investigate optimal scaffold architectures. Additionally, 3D β-TCP/HA vacuum-coated with alginate, presented improved compressive strength, fracture toughness and Young's modulus, to values similar to those of native bone. The hybrid 3D polymeric–bioceramic scaffolds also supported osteoblast adhesion, maturation and proliferation, as demonstrated by fluorescence microscopy. To the best of our knowledge this is the first time that a 3D scaffold produced with this combination of biomaterials is described. Altogether, our results emphasize that this hybrid scaffold presents promising characteristics for its future application in bone regeneration. - Graphical abstract: B-TCP:HA–alginate hybrid 3D porous scaffolds for application in bone regeneration. - Highlights: • The produced hybrid 3D scaffolds are prone to be applied in bone tissue engineering. • Alginate coated 3D scaffolds present high mechanical and biological properties. • In vitro assays for evaluation of human osteoblast cell attachment in the presence of the scaffolds • The hybrid 3D scaffolds present suitable mechanical and biological properties for use in bone regenerative medicine.

  19. Effect of allogenic freeze-dried demineralized bone matrix on guided tissue regeneration in dogs.

    Science.gov (United States)

    Caplanis, N; Lee, M B; Zimmerman, G J; Selvig, K A; Wikesjö, U M

    1998-08-01

    This randomized, split-mouth study was designed to evaluate the adjunctive effect of allogenic, freeze-dried, demineralized bone matrix (DBM) to guided tissue regeneration (GTR). Contralateral fenestration defects (6 x 4 mm) were created 6 mm apical to the buccal alveolar crest on maxillary canine teeth in 6 beagle dogs. DBM was implanted into one randomly selected fenestration defect. Expanded polytetrafluoroethylene (ePTFE) membranes were used to provide bilateral GTR. Tissue blocks including defects with overlying membranes and soft tissues were harvested following a four-week healing interval and prepared for histometric analysis. Differences between GTR+DBM and GTR defects were evaluated using a paired t-test (N = 6). DBM was discernible in all GTR+DBM defects with limited, if any, evidence of bone metabolic activity. Rather, the DBM particles appeared solidified within a dense connective tissue matrix, often in close contact to the instrumented root. There were no statistically significant differences between the GTR+DBM versus the GTR condition for any histometric parameter examined. Fenestration defect height averaged 3.7+/-0.3 and 3.9+/-0.3 mm, total bone regeneration 0.8+/-0.6 and 1.5+/-0.8 mm, and total cementum regeneration 2.0+/-1.3 and 1.6+/-1.7 mm for GTR+DBM and GTR defects, respectively. The histologic and histometric observations, in concert, suggest that allogenic freeze-dried DBM has no adjunctive effect to GTR in periodontal fenestration defects over a four-week healing interval. The critical findings were 1) the DBM particles remained, embedded in dense connective tissue without evidence of bone metabolic activity; and 2) limited and similar amounts of bone and cementum regeneration were observed for both the GTR+DBM and GTR defects.

  20. The relationship between the mechanical anisotropy of human cortical bone tissue and its microstructure

    Science.gov (United States)

    Espinoza Orias, Alejandro A.

    Orthopedics research has made significant advances in the areas of biomechanics, bone implants and bone substitute materials. However, to date there is no definitive model to explain the structure-property relationships in bone as a material to enable better implant designs or to develop a true biomechanical analog of bone. The objective of this investigation was to establish a relationship between the elastic anisotropy of cortical bone tissue and its microstructure. Ultrasonic wave propagation was used to measure stiffness coefficients for specimens sectioned along the length of a human femur. The elastic constants were orthotropic and varied with anatomical location. Stiffness coefficients were generally largest at the midshaft and stiffness anisotropy ratios were largest at the distal and proximal ends. These tests were run on four additional human femurs to assess the influence of phenotypic variation, and in most cases, it was found that phenotypes do not exert a significant effect. Stiffness coefficients were shown to be correlated as a power law relation to apparent density, but anisotropy ratios were not. Texture analysis was performed on selected samples to measure the orientation distribution of the bone mineral crystals. Inverse pole figures showed that bone mineral crystals had a preferred crystallographic orientation, coincident with the long axis of the femur, which is its principal loading direction. The degree of preferred orientation was represented in Multiples of a Random Distribution (MRD), and correlated to the anisotropy ratios. Variation in elastic anisotropy was shown to be primarily due to the bone mineral orientation. The results found in this work can be used to incorporate anisotropy into structural analysis for bone as a material.

  1. Value and limits of μ-CT for nondemineralized bone tissue processing.

    Science.gov (United States)

    Draenert, Miriam Esther; Draenert, Alice Irène; Forriol, Francisco; Cerler, Michael; Kunzelmann, Karl-Heinz; Hickel, Reinhard; Draenert, Klaus

    2012-04-01

    An experimental approach was performed on 20 giant rabbits to establish the possibilities and limitations of μ-CT for routine processing of nondemineralized bone tissue. Hydroxyapatite (HA) or β-tricalciumphosphate (β-TCP) bead implants or a melange of both, microchambered and solid, were implanted into a standardized and precise defect in the patellar groove. The bone-healing phase was chosen for the histology considering 1 or 2 days, and 2, 3, and 6 weeks. Normal X-ray and μ-CT were applied on all specimens; five specimens in the 6-week stage were additionally processed according to the full range of conventional nondemineralized bone processing methods. μ-CT increased the possibilities of nondemineralized histology with respect to bone morphometry and a complete sequence of sections, thus providing a complete analysis of the bone response. μ-CT was limited in differentiating bone quality, cell analyses, and mineralization stages. The investigation based on normal X-rays is limited to defining integration and excluding the fibrous and bony encapsulation of loose implants. μ-CT allows a 3D evaluation of newly formed bone which is clearly marked against the ceramic implant. It does not allow, however, for the differentiation between woven and lamellar bone, the presentation of the canalicular lacunar system, or on the cell level, revealing canaliculi or details of the mineralization process which can be documented by high-resolution microradiography. Titer dynamics of bone formation remains the domain of polychromatic sequential labeling. The complete sequence of μ-CT slices enhances the possibilities for routine histology, tremendously allowing to the focus on detail histology to topographically well-defined cuts, thus providing more precise conclusions which take into consideration the whole implant.

  2. Perkembangan Terkini Membran Guided Tissue Regeneration/Guided Bone Regeneration sebagai Terapi Regenerasi Jaringan Periodontal

    Directory of Open Access Journals (Sweden)

    Cindy Cahaya

    2015-06-01

    kombinasi prosedur-prosedur di atas, termasuk prosedur bedah restoratif yang berhubungan dengan rehabilitasi oral dengan penempatan dental implan. Pada tingkat selular, regenerasi periodontal adalah proses kompleks yang membutuhkan proliferasi yang terorganisasi, differensiasi dan pengembangan berbagai tipe sel untuk membentuk perlekatan periodontal. Rasionalisasi penggunaan guided tissue regeneration sebagai membran pembatas adalah menahan epitel dan gingiva jaringan pendukung, sebagai barrier membrane mempertahankan ruang dan gigi serta menstabilkan bekuan darah. Pada makalah ini akan dibahas sekilas mengenai 1. Proses penyembuhan terapi periodontal meliputi regenerasi, repair ataupun pembentukan perlekatan baru. 2. Periodontal spesific tissue engineering. 3. Berbagai jenis membran/guided tissue regeneration yang beredar di pasaran dengan keuntungan dan kerugian sekaligus karakteristik masing-masing membran. 4. Perkembangan membran terbaru sebagai terapi regenerasi penyakit periodontal. Tujuan penulisan untuk memberi gambaran masa depan mengenai terapi regenerasi yang menjanjikan sebagai perkembangan terapi penyakit periodontal.   Latest Development of Guided Tissue Regeneration and Guided Bone Regeneration Membrane as Regenerative Therapy on Periodontal Tissue. Periodontitis is a patological state which influences the integrity of periodontal system that could lead to the destruction of the periodontal tissue and end up with tooth loss. Currently, there are so many researches and efforts to regenerate periodontal tissue, not only to stop the process of the disease but also to reconstruct the periodontal tissue. Periodontal regenerative therapy aims at directing the growth of new bone, cementum and periodontal ligament on the affected teeth. Regenerative procedures consist of soft tissue graft, bone graft, roots biomodification, guided tissue regeneration and combination of the procedures, including restorative surgical procedure that is

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

    Science.gov (United States)

    Shimko, Daniel Andrew

    2004-12-01

    In 2000, 3.1 million surgical procedures on the musculoskeletal system were reported in the United States. For many of these cases, bone grafting was essential for successful fracture stabilization. Current techniques use intact bone obtained either from the patient (autograft) or a cadaver (allograft) to repair large defects, however, neither source is optimal. Allografts suffer integration problems, and for autografts, the tissue supply is limited. Because of these shortcomings, and the high demand for graft tissues, alternatives are being explored. To successfully engineer a bone graft replacement, one must employ a three pronged research approach, addressing (1) the cells that will inhabit the new tissue, (2) the culture environment that these cells will be exposed to, and (3) the scaffold in which these cells will reside. The work herein examines each of these three aspects in great detail. Both adult and embryonic stem cells (ESCs) were considered for the tissue-engineered bone graft. Both exhibited desirable qualities, however, neither were optimal in all categories examined. In the end, the possibility of teratoma formation and ethical issues surrounding ESCs, made the use of adult marrow-derived stem cells in the remaining experiments obligatory. In subsequent experiments, the adult stem cells' ability to form bone was optimized. Basic fibroblast growth factor, fetal bovine serum, and extracellular calcium supplementation studies were all performed. Ultimately, adult stem cells cultured in alpha-MEM supplemented with 10% fetal bovine serum, 10mM beta-glycerophosphate, 10nM dexamethasone, 50mug/ml ascorbic acid, 1%(v/v) antibiotic/antimycotic, and 10.4mM CaCl2 performed the best, producing nearly four times more mineral than any other medium formulation. Several scaffolds were then investigated including those fabricated from poly(alpha-hydroxy esters), tantalum, and poly-methylmethacrylate. In the final study, the most appealing cell type, medium

  4. Poly(dopamine) coating to biodegradable polymers for bone tissue engineering.

    Science.gov (United States)

    Tsai, Wei-Bor; Chen, Wen-Tung; Chien, Hsiu-Wen; Kuo, Wei-Hsuan; Wang, Meng-Jiy

    2014-02-01

    In this study, a technique based on poly(dopamine) deposition to promote cell adhesion was investigated for the application in bone tissue engineering. The adhesion and proliferation of rat osteoblasts were evaluated on poly(dopamine)-coated biodegradable polymer films, such as polycaprolactone, poly(l-lactide) and poly(lactic-co-glycolic acid), which are commonly used biodegradable polymers in tissue engineering. Cell adhesion was significantly increased to a plateau by merely 15 s of dopamine incubation, 2.2-4.0-folds of increase compared to the corresponding untreated substrates. Cell proliferation was also greatly enhanced by poly(dopamine) deposition, indicated by shortened cell doubling time. Mineralization was also increased on the poly(dopamine)-deposited surfaces. The potential of poly(dopamine) deposition in bone tissue engineering is demonstrated in this study.

  5. A proteomic study of protein variation between osteopenic and age-matched control bone tissue.

    Science.gov (United States)

    Chaput, Christopher D; Dangott, Lawrence J; Rahm, Mark D; Hitt, Kirby D; Stewart, Donald S; Wayne Sampson, H

    2012-05-01

    The focus of this study was to identify changes in protein expression within the bone tissue environment between osteopenic and control bone tissue of human femoral neck patients with osteoarthritis. Femoral necks were compared from osteopenic patients and age-matched controls. A new method of bone protein extraction was developed to provide a swift, clear view of the bone proteome. Relative changes in protein expression between control and osteopenic samples were quantified using difference gel electrophoresis (DIGE) technology after affinity chromatographic depletion of albumin and IgG. The proteins that were determined to be differentially expressed were identified using standard liquid chromatography mass spectrometry (LC/MS/MS) and database searching techniques. In order to rule out blood contamination, blood from age-matched osteoporotic, osteopenic and controls were analyzed in a similar manner. Image analysis of the DIGE gels indicated that 145 spots in the osteopenic bone samples changed at least ± 1.5-fold from the control samples (P proteins were identified by LC/MS/MS. Of the proteins that increased in the osteopenic femurs, two were especially significant: carbonic anhydrase I and phosphoglycerate kinase 1. Apolipoprotein A-I was the most prominent protein that significantly decreased in the osteopenic femurs. The blood samples revealed no significant differences between groups for any of these proteins. In conclusion, carbonic anhydrase I, phosphoglycerate kinase 1 and apolipoprotein A-I appeared to be the most significant variations of proteins in patients with osteopenia and osteoarthritis.

  6. The evolution of simulation techniques for dynamic bone tissue engineering in bioreactors.

    Science.gov (United States)

    Vetsch, Jolanda Rita; Müller, Ralph; Hofmann, Sandra

    2015-08-01

    Bone tissue engineering aims to overcome the drawbacks of current bone regeneration techniques in orthopaedics. Bioreactors are widely used in the field of bone tissue engineering, as they help support efficient nutrition of cultured cells with the possible combination of applying mechanical stimuli. Beneficial influencing parameters of in vitro cultures are difficult to find and are mostly determined by trial and error, which is associated with significant time and money spent. Mathematical simulations can support the finding of optimal parameters. Simulations have evolved over the last 20 years from simple analytical models to complex and detailed computational models. They allow researchers to simulate the mechanical as well as the biological environment experienced by cells seeded on scaffolds in a bioreactor. Based on the simulation results, it is possible to give recommendations about specific parameters for bone bioreactor cultures, such as scaffold geometries, scaffold mechanical properties, the level of applied mechanical loading or nutrient concentrations. This article reviews the evolution in simulating various aspects of dynamic bone culture in bioreactors and reveals future research directions.

  7. Donor exclusion in the National Blood Service Tissue Services living bone donor programme.

    Science.gov (United States)

    Pink, F; Warwick, R M; Purkis, J; Pearson, J

    2006-01-01

    National Blood Service (NBS) Tissue Services (TS) operates living donor and deceased donor tissue banking programmes. The living bone donor programme operates in collaboration with 91 orthopaedic departments across the country and collects bone donations, in the form of surgically removed femoral heads (FHs), from over 5,000 patients per annum undergoing total hip replacement. Bone donated via the living programme constitutes approximately 55% of the total bone donated to NBS. Non-NBS tissue banks, primarily in hospital orthopaedic departments, also bank donated bone for the UK. A survey of information received from 16 collaborating orthopaedic centres, between April 2003 and August 2004, identified 709 excluded donors. The total number of donations banked from these sites was 1,538. Donations can be excluded before collection if there are contraindications noted in a potential donor's medical history before their operation. Donors may also be excluded after collection of the FH, for instance because of reactive microbiology tests for blood borne viruses, or if the donation storage conditions or related documentation have not met stringent quality requirements. In this survey, bone or joint conditions were the major reasons for excluding potential donors before donation (154 of 709 exclusions, 22%), followed by a current or a past history of malignancy (139 of 709 exclusions, 20%). Local staffing and operational difficulties sometimes resulted in potential donors being missed, or specific reasons for exclusion not being reported (117 exclusions). These out numbered exclusions due to patient refusal (80 exclusions). A small number (quality. Training to ensure that standards are complied with and a firm evidence base for exclusion criteria, applied uniformly, will help focus donor identification efforts on individuals meeting rational criteria so that fewer potential donations are lost.

  8. Biodegradation, biocompatibility, and osteoconduction evaluation of collagen-nanohydroxyapatite cryogels for bone tissue regeneration.

    Science.gov (United States)

    Salgado, Christiane Laranjo; Grenho, Liliana; Fernandes, Maria Helena; Colaço, Bruno Jorge; Monteiro, Fernando Jorge

    2016-01-01

    Designing biomimetic biomaterials inspired by the natural complex structure of bone and other hard tissues is still a challenge nowadays. The control of the biomineralization process onto biomaterials should be evaluated before clinical application. Aiming at bone regeneration applications, this work evaluated the in vitro biodegradation and interaction between human bone marrow stromal cells (HBMSC) cultured on different collagen/nanohydroxyapatite cryogels. Cell proliferation, differentiation, morphology, and metabolic activity were assessed through different protocols. All the biocomposite materials allowed physiologic apatite deposition after incubation in simulated body fluid and the cryogel with the highest nanoHA content showed to have the highest mechanical strength (DMA). The study clearly showed that the highest concentration of nanoHA granules on the cryogels were able to support cell type's survival, proliferation, and individual functionality in a monoculture system, for 21 days. In fact, the biocomposites were also able to differentiate HBMSCs into osteoblastic phenotype. The composites behavior was also assessed in vivo through subcutaneous and bone implantation in rats to evaluate its tissue-forming ability and degradation rate. The cryogels Coll/nanoHA (30 : 70) promoted tissue regeneration and adverse reactions were not observed on subcutaneous and bone implants. The results achieved suggest that scaffolds of Coll/nanoHA (30 : 70) should be considered promising implants for bone defects that present a grotto like appearance with a relatively small access but a wider hollow inside. This material could adjust to small dimensions and when entering into the defect, it could expand inside and remain in close contact with the defect walls, thus ensuring adequate osteoconductivity.

  9. Bones - joints - soft tissues II. 7. rev. ed. Knochen - Gelenke - Weichteile II

    Energy Technology Data Exchange (ETDEWEB)

    Dihlmann, W. (Roentgeninstitut, Allgemeines Krankenhaus Barmbek, Hamburg (Germany)); Frommhold, W. (Radiologische Klinik, Tuebingen Univ. (Germany)) (eds.)

    1991-01-01

    With the publication of the 2nd part to Volume VI, 'Bones - joints - soft tissues', the 7th edition of 'Diagnostic radiology in the hospital and medical practice' is complete. The advances made particularly during the past decade in the field of diagnostic radiology have made it neccesary for all the individual sections to be completely revised. Recently developed methods of imaging like sonography, computed tomography and magnetic resonance tomography are increasingly used as a replacement for or, at least, an adjunct to conventional X-ray procedures. Owing to the development and continuous refinement of related methods of intervention the gap between mere diagnostic applications and therapeutic uses of radiology could eventually be closed. The issues mainly discussed in this volume are bone fractures and healing, bone transplantation, osteopathy and osteoarthropathy, fibrous dyplasia or Albright's disease, Pagetoid osteitis, genetically transmitted constitutional disorders of the skeleton and soft tissue changes. While in the key sections on bone fractures and healing, osteopathy and osteoarthropathy as well as constitutional genetic disorders X-ray techniques are still described as the prevailing method of diagnosis, diseases of soft tissues now are much more commonly diagnosed using magnetic resonance imaging. (orig./MG) With 2248 figs., 59 tabs.

  10. From stem cells to bone: phenotype acquisition, stabilization, and tissue engineering in animal models.

    Science.gov (United States)

    Gordeladze, Jan O; Reseland, Janne E; Duroux-Richard, Isabelle; Apparailly, Florence; Jorgensen, Christian

    2009-01-01

    The regeneration of bone tissue depends on the concerted actions of a plethora of signals that recruit mesenchymal stem cells for lineage-specific differentiation, with cellular phenotypes serving various functions throughout their life span. The signals are conveyed in hormones, growth factors, and mechanical forces, all of which ensure proper modeling and remodeling. Both processes are secured by indigenous and programmed metabolism in osteoblasts/osteocytes as well as in other stem cell (SC)-derived cell types (e.g., osteoclasts, bone lining cells) involved in the remodeling of the subject tissue. The focus of this review is the concerted action of these signals as well as the regulatory and/or stabilizing control circuits exhibited by a class of small RNAs, designated microRNAs. We discuss an in vitro approach for ensuring proper phenotype acquisition as well as the choice of scaffolds and animal models for in vivo tissue repair. This approach includes selection of SC niches to optimize bone formation in vivo, transcription factors important for osteoblastogenesis, the Wnt and Notch pathways of signaling, selection of delivery systems for gene therapy, use of appropriate matrices and scaffolds, in vivo mechanostimulation, choice of lesions to be repaired, and type of animal to use. We also discuss Wnt-related and SC-based treatment of osteoporosis. Throughout, we offer considerations for the selection of model systems and parameters to assess the entire procedure from initial SC selection to final bone repair, and conclude with a table summarizing our recommendations.

  11. Osteogenic Differentiation Capacity of In Vitro Cultured Human Skeletal Muscle for Expedited Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Chunlei Miao

    2017-01-01

    Full Text Available Expedited bone tissue engineering employs the biological stimuli to harness the intrinsic regenerative potential of skeletal muscle to trigger the reparative process in situ to improve or replace biological functions. When genetically modified with adenovirus mediated BMP2 gene transfer, muscle biopsies from animals have demonstrated success in regenerating bone within rat bony defects. However, it is uncertain whether the human adult skeletal muscle displays an osteogenic potential in vitro when a suitable biological trigger is applied. In present study, human skeletal muscle cultured in a standard osteogenic medium supplemented with dexamethasone demonstrated significant increase in alkaline phosphatase activity approximately 24-fold over control at 2-week time point. More interestingly, measurement of mRNA levels revealed the dramatic results for osteoblast transcripts of alkaline phosphatase, bone sialoproteins, transcription factor CBFA1, collagen type I, and osteocalcin. Calcified mineral deposits were demonstrated on superficial layers of muscle discs after an extended 8-week osteogenic induction. Taken together, these are the first data supporting human skeletal muscle tissue as a promising potential target for expedited bone regeneration, which of the technologies is a valuable method for tissue repair, being not only effective but also inexpensive and clinically expeditious.

  12. Osteogenic Differentiation Capacity of In Vitro Cultured Human Skeletal Muscle for Expedited Bone Tissue Engineering

    Science.gov (United States)

    Miao, Chunlei; Zhou, Lulu; Tian, Lufeng; Zhang, Yingjie; Zhang, Wei; Yang, Fanghong; Liu, Tianyi

    2017-01-01

    Expedited bone tissue engineering employs the biological stimuli to harness the intrinsic regenerative potential of skeletal muscle to trigger the reparative process in situ to improve or replace biological functions. When genetically modified with adenovirus mediated BMP2 gene transfer, muscle biopsies from animals have demonstrated success in regenerating bone within rat bony defects. However, it is uncertain whether the human adult skeletal muscle displays an osteogenic potential in vitro when a suitable biological trigger is applied. In present study, human skeletal muscle cultured in a standard osteogenic medium supplemented with dexamethasone demonstrated significant increase in alkaline phosphatase activity approximately 24-fold over control at 2-week time point. More interestingly, measurement of mRNA levels revealed the dramatic results for osteoblast transcripts of alkaline phosphatase, bone sialoproteins, transcription factor CBFA1, collagen type I, and osteocalcin. Calcified mineral deposits were demonstrated on superficial layers of muscle discs after an extended 8-week osteogenic induction. Taken together, these are the first data supporting human skeletal muscle tissue as a promising potential target for expedited bone regeneration, which of the technologies is a valuable method for tissue repair, being not only effective but also inexpensive and clinically expeditious. PMID:28210626

  13. Boon and Bane of Inflammation in Bone Tissue Regeneration and Its Link with Angiogenesis.

    Science.gov (United States)

    Schmidt-Bleek, Katharina; Kwee, Brian J; Mooney, David J; Duda, Georg N

    2015-08-01

    Delayed healing or nonhealing of bone is an important clinical concern. Although bone, one of the two tissues with scar-free healing capacity, heals in most cases, healing is delayed in more than 10% of clinical cases. Treatment of such delayed healing condition is often painful, risky, time consuming, and expensive. Tissue healing is a multistage regenerative process involving complex and well-orchestrated steps, which are initiated in response to injury. At best, these steps lead to scar-free tissue formation. At the onset of healing, during the inflammatory phase, stationary and attracted macrophages and other immune cells at the fracture site release cytokines in response to injury. This initial reaction to injury is followed by the recruitment, proliferation, and differentiation of mesenchymal stromal cells, synthesis of extracellular matrix proteins, angiogenesis, and finally tissue remodeling. Failure to heal is often associated with poor revascularization. Since blood vessels mediate the transport of circulating cells, oxygen, nutrients, and waste products, they appear essential for successful healing. The strategy of endogenous regeneration in a tissue such as bone is interesting to analyze since it may represent a blueprint of successful tissue formation. This review highlights the interdependency of the time cascades of inflammation, angiogenesis, and tissue regeneration. A better understanding of these inter-relations is mandatory to early identify patients at risk as well as to overcome critical clinical conditions that limit healing. Instead of purely tolerating the inflammatory phase, modulations of inflammation (immunomodulation) might represent a valid therapeutic strategy to enhance angiogenesis and foster later phases of tissue regeneration.

  14. Tracking calcification in tissue-engineered bone using synchrotron micro-FTIR and SEM.

    Science.gov (United States)

    Deegan, Anthony J; Cinque, Gianfelice; Wehbe, Katia; Konduru, Sandeep; Yang, Ying

    2015-02-01

    One novel tissue engineering approach to mimic in vivo bone formation is the use of aggregate or micromass cultures. Various qualitative and quantitative techniques, such as histochemical staining, protein assay kits and RT-PCR, have been used previously on cellular aggregate studies to investigate how these intricate arrangements lead to mature bone tissue. However, these techniques struggle to reveal spatial and temporal distribution of proliferation and mineralization simultaneously. Synchrotron-based Fourier transform infrared microspectroscopy (micro-FTIR) offers a unique insight at the molecular scale by coupling high IR sensitivity to organic matter with the high spatial resolution allowed by diffraction limited SR microbeam. This study is set to investigate the effects of culture duration and aggregate size on the dynamics and spatial distribution of calcification in engineered bone aggregates by a combination of micro-FTIR and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX). A murine bone cell line has been used, and small/large bone aggregates have been induced using different chemically treated culture substrates. Our findings suggest that bone cell aggregate culturing can greatly increase levels of mineralization over short culture periods. The size of the aggregates influences mineralisation rates with larger aggregates mineralizing at a faster rate than their smaller counterparts. The micro-FTIR mapping has demonstrated that mineralization in the larger aggregates initiated from the periphery and spread to the centre, whilst the smaller aggregates have more minerals in the centre at the early stage and deposited more in the periphery after further culturing, implying that aggregate size influences calcification distribution and development over time. SEM/EDX data correlates well with the micro-FTIR results for the total mineral content. Thus, synchrotron-based micro-FTIR can accurately track mineralization process

  15. Strategies to stimulate mobilization and homing of endogenous stem and progenitor cells for bone tissue repair

    Directory of Open Access Journals (Sweden)

    Marietta eHerrmann

    2015-06-01

    Full Text Available The gold standard for the treatment of critical sized 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.

  16. Magnesium intake mediates the association between bone mineral density and lean soft tissue in elite swimmers.

    Science.gov (United States)

    Matias, Catarina N; Santos, Diana A; Monteiro, Cristina P; Vasco, Ana M; Baptista, Fátima; Sardinha, Luís B; Laires, Maria J; Silva, Analiza M

    2012-01-01

    Magnesium (Mg) deficiency has been associated with bone disorders. Physical activity is also crucial for bone mineralization. Bone mass loss has been observed to be accelerated in subjects with low Mg intake. We aim to understand if Mg intake mediates the association between bone mineral density (BMD) and lean soft tissue (LST) in elite swimmers. Seventeen elite swimmers (eight males; nine females) were evaluated. Bone mineral content, BMD, LST, and fat mass were assessed using dual energy X-ray absorptiometry. Energy and nutrient intake were assessed during a seven-day period and analyzed with Food Processor SQL. Males presented lower values than the normative data for BMD. Mg, phosphorus (P) and vitamin D intake were significantly lower than the recommended daily allowance. A linear regression model demonstrated a significant association between LST and BMD. When Mg intake was included, we observed that this was a significant, independent predictor of BMD, with a significant increase of 24% in the R(2) of the initial predictive model. When adjusted for energy, vitamin D, calcium, and P intake, Mg remained a significant predictor of BMD. In conclusion, young athletes engaged in low impact sports, should pay special attention to Mg intake, given its potential role in bone mineral mass acquisition during growth.

  17. Human Bone Marrow Stromal Cells: A Reliable, Challenging Tool for In Vitro Osteogenesis and Bone Tissue Engineering Approaches

    Directory of Open Access Journals (Sweden)

    Ute Hempel

    2016-01-01

    Full Text Available Adult human bone marrow stromal cells (hBMSC are important for many scientific purposes because of their multipotency, availability, and relatively easy handling. They are frequently used to study osteogenesis in vitro. Most commonly, hBMSC are isolated from bone marrow aspirates collected in clinical routine and cultured under the “aspect plastic adherence” without any further selection. Owing to the random donor population, they show a broad heterogeneity. Here, the osteogenic differentiation potential of 531 hBMSC was analyzed. The data were supplied to correlation analysis involving donor age, gender, and body mass index. hBMSC preparations were characterized as follows: (a how many passages the osteogenic characteristics are stable in and (b the influence of supplements and culture duration on osteogenic parameters (tissue nonspecific alkaline phosphatase (TNAP, octamer binding transcription factor 4, core-binding factor alpha-1, parathyroid hormone receptor, bone gla protein, and peroxisome proliferator-activated protein γ. The results show that no strong prediction could be made from donor data to the osteogenic differentiation potential; only the ratio of induced TNAP to endogenous TNAP could be a reliable criterion. The results give evidence that hBMSC cultures are stable until passage 7 without substantial loss of differentiation potential and that established differentiation protocols lead to osteoblast-like cells but not to fully authentic osteoblasts.

  18. Three-dimensional chitosan-nanohydroxyapatite composite scaffolds for bone tissue engineering

    Science.gov (United States)

    Thein-Han, W. W.; Misra, R. D. K.

    2009-09-01

    We describe the structure of biodegradable chitosan-nanohydroxyapatite (nHA) composites scaffolds and their interaction with pre-osteoblasts for bone tissue engineering. The scaffolds were fabricated via freezing and lyophilization. The nanocomposite scaffolds were characterized by a highly porous structure and pore size of ˜50-125 μm, irrespective of nHA content. The observed significant enhancement in the biological response of pre-osteoblast on nanocomposite scaffolds expressed in terms of cell attachment, proliferation, and widespread morphology in relation to pure chitosan points toward their potential use as scaffold material for bone regeneration.

  19. Wound healing after irradiation of bone tissues by Er:YAG laser

    Science.gov (United States)

    Watanabe, Hisashi; Yoshino, Toshiaki; Aoki, Akira; Ishikawa, Isao

    1997-05-01

    Clinical applications of Er:YAG laser are now developing in periodontics and restorative dentistry. To date, there have been few studies indicating safety criteria for intraoral usage of the Er:YAG laser. The present study examined the effects of the Er:YAG laser on bone tissues, supposing mis- irradiation in the oral cavity during dental application, especially periodontal surgery. The experiments were performed using the newly-developed Er:YAG laser apparatus equipped with a contact probe. In experiment 1, 10 pulses of laser irradiation were administered to the parietal bone of a rat at 50, 150 and 300 mJ/pulse with and without water irrigation, changing the irradiation distance to 0, 5, 10 and 20 mm, respectively. As a control, electric knife was employed. Macroscopic and SEM observations of the wound surface were performed. In experiment 2, laser irradiation in a straight line was performed at 150 mJ/pulse, 1- pps and 0,5, 10 mm irradiation distance without water irrigation. Wound healing was observed histologically at 0, 3, 7, 14 and 28 days after laser irradiation and compared with that of the control. Non-contact irradiation by Er:YAG laser did not cause severe damage to the parietal bone tissue under water irrigation. Contact irradiation induced a limited wound, however, new bone formation was observed 28 days after laser irradiation, while osseous defect with thermal degenerative tissue remained at the control site. In conclusion, irradiation with an Er:YAG laser would not cause severe damage to surrounding bone tissues in the oral cavity when used within the usual power settings for dental treatment. Furthermore, this laser may be applicable for osseous surgery because of its high ablation efficiency and good wound healing after irradiation.

  20. Tautomerizable β-ketonitrile copolymers for bone tissue engineering: Studies of biocompatibility and cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Lastra, M. Laura [Laboratorio de Investigaciones en Osteopatías y Metabolismo Mineral (LIOMM), Facultad de Ciencias Exactas, UNLP (1900), 47 y 115, 1900 La Plata (Argentina); Molinuevo, M. Silvina, E-mail: silvinamolinuevo@yahoo.com.ar [Laboratorio de Investigaciones en Osteopatías y Metabolismo Mineral (LIOMM), Facultad de Ciencias Exactas, UNLP (1900), 47 y 115, 1900 La Plata (Argentina); Giussi, Juan M. [Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata, CC16 suc. 4, 1900 La Plata (Argentina); Laboratorio de Estudio de Compuestos Orgánicos (LADECOR), Facultad de Ciencias Exactas, UNLP, 47 y 115, 1900 La Plata (Argentina); Allegretti, Patricia E. [Laboratorio de Estudio de Compuestos Orgánicos (LADECOR), Facultad de Ciencias Exactas, UNLP, 47 y 115, 1900 La Plata (Argentina); Blaszczyk-Lezak, Iwona; Mijangos, Carmen [Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan de la Cierva 3, 28006 Madrid (Spain); Cortizo, M. Susana, E-mail: gcortizo@infta.unlp.edu.ar [Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata, CC16 suc. 4, 1900 La Plata (Argentina)

    2015-06-01

    β-Ketonitrile tautomeric copolymers have demonstrated tunable hydrophilicity/hydrophobicity properties according to surrounding environment, and mechanical properties similar to those of human bone tissue. Both characteristic properties make them promising candidates as biomaterials for bone tissue engineering. Based on this knowledge we have designed two scaffolds based on β-ketonitrile tautomeric copolymers which differ in chemical composition and surface morphology. Two of them were nanostructured, using an anodized aluminum oxide (AAO) template, and the other two obtained by solvent casting methodology. They were used to evaluate the effect of the composition and their structural modifications on the biocompatibility, cytotoxicity and degradation properties. Our results showed that the nanostructured scaffolds exhibited higher degradation rate by macrophages than casted scaffolds (6 and 2.5% of degradation for nanostructured and casted scaffolds, respectively), a degradation rate compatible with bone regeneration times. We also demonstrated that the β-ketonitrile tautomeric based scaffolds supported osteoblastic cell proliferation and differentiation without cytotoxic effects, suggesting that these biomaterials could be useful in the bone tissue engineering field. - Graphical abstract: β-Ketonitrile tautomeric copolymers were nanostructured in nanorods using anodized aluminum oxide (AAO) template. These nanorods had good biocompatibility properties supporting osteoblastic growth and differentiation without cytotoxic effects, making them promising for bone tissue engineering. - Highlights: • Tautomeric β-ketonitrile copolymer based scaffold was obtained with different compositions. • Scaffolds exhibited tunable hydrophilicity/hydrophobicity properties and good mechanical properties. • Nanostructured scaffolds exhibited higher degradation rate than casted scaffolds by macrophages. • Scaffolds support osteoblastic cell proliferation and

  1. Guided bone regeneration in pig calvarial bone defects using autologous mesenchymal stem/progenitor cells - a comparison of different tissue sources.

    Science.gov (United States)

    Stockmann, Philipp; Park, Jung; von Wilmowsky, Cornelius; Nkenke, Emeka; Felszeghy, Endre; Dehner, Jan-Friedrich; Schmitt, Christian; Tudor, Christian; Schlegel, Karl Andreas

    2012-06-01

    Due to donor side morbidity and the absence of osteogenic properties in bone substitutes, there is a growing need for an alternative to traditional bone grafting within the scope of tissue engineering. This animal study was conducted to compare the in vivo osteogenic potential of adipose-derived (AD), periosteum-derived (PD) and bone marrow-derived (BM) mesenchymal stem/progenitor cells (MSC). Autologous mesenchymal stem/progenitor cells of named tissue origin were induced into osteogenic differentiation following in vitro cell expansion. Ex vivo cultivated cells were seeded on a collagen scaffold and subsequently added to freshly created monocortical calvarial bone defects in 21 domestic pigs. Pure collagen scaffold served as a control defect. The animals were sacrificed at specific time points and de novo bone formation was quantitatively analyzed by histomorphometry. Bone volume/total defect volume (BV/TV) and the mineralization rate of newly formed bone were compared among the groups. In the early stages of wound healing, up to 30 days, the test defects did not show better bone regeneration than those in the control defect, but the bone healing process in the test defects was accelerated in the later stage compared to those in the control defect. All the test defects showed complete osseous healing after 90 days compared to those in the control defect. During the observation period, no significant differences in BV/TV and mineralization of newly formed bone among the test defects were observed. Irrespective of the tissue sources of MSC, the speed and pattern of osseous healing after cell transplantations into monocortical bone defects were comparable. Our results indicate that the efficiency of autologous AD-MSC, PD-MSC and BM-MSC transplantation following ex vivo cell expansion is not significantly different for the guided regeneration of bone defects.

  2. Effect of hemiplegia on bone mass and soft tissue body composition

    Energy Technology Data Exchange (ETDEWEB)

    Iversen, E.; Hassager, C.; Christiansen, C.

    1989-01-01

    The content of bone mineral (BMC), lean tissue, and fat tissue were measured by single and dual photon absorptiometry in both the paretic and the nonparetic limbs of 15 patients, hemiplegic due to cerebrovascular accident 23-38 weeks earlier. Compared with the non-paretic arm, the paretic arm had approximately 10% lower (P < 0.01) BMC. This difference was largest at the measuring site with the highest ratio of trabecular to compact bone. The paretic leg had a 4% (P < 0.001) lower BMC than the non-paretic leg. For both the arms and the legs, the lean content was lower (P < 0.05) and the fat content higher (P < 0.01) in the paretic than in the non-paretic. This was relatively more pronounced in the arms than in the legs. We conclude that partial immobilization, owing to parasis after a cerebrovascular accident, results in characteristic changes in the affected limbs, with a marked decrease in the content of bone and lean tissue and a pronounced increase in fatty tissue.

  3. Preparation and mechanical property of a novel 3D porous magnesium scaffold for bone tissue engineering.

    Science.gov (United States)

    Zhang, Xue; Li, Xiao-Wu; Li, Ji-Guang; Sun, Xu-Dong

    2014-09-01

    Porous magnesium has been recently recognized as a biodegradable metal for bone substitute applications. A novel porous Mg scaffold with three-dimensional (3D) interconnected pores and with a porosity of 33-54% was produced by the fiber deposition hot pressing (FDHP) technology. The microstructure and morphologies of the porous Mg scaffold were characterized by scanning electron microscopy (SEM), and the effects of porosities on the microstructure and mechanical properties of the porous Mg were investigated. Experimental results indicate that the measured Young's modulus and compressive strength of the Mg scaffold are ranged in 0.10-0.37 GPa, and 11.1-30.3 MPa, respectively, which are fairly comparable to those of cancellous bone. Such a porous Mg scaffold having a 3D interconnected network structure has the potential to be used in bone tissue engineering.

  4. Metals in Bone Tissue of Antillean Manatees from the Gulf of Mexico and Chetumal Bay, Mexico.

    Science.gov (United States)

    Romero-Calderón, Ana G; Morales-Vela, Benjamin; Rosíles-Martínez, René; Olivera-Gómez, León D; Delgado-Estrella, Alberto

    2016-01-01

    Concentrations of seven metals (As, Cd, Cr, Cu, Pb, Ni, and Zn) were analyzed in 33 bone tissue samples of Antillean manatees (Trichechus manatus manatus) found dead in lagoons and rivers of Tabasco and Campeche in the Gulf of Mexico and Chetumal Bay in the Caribbean region. The concentrations of Cr, Cu, Pb, and Zn were significantly different between regions, with greater levels found in the Gulf of Mexico group than in the Mexican Caribbean group (p < 0.05). Pb concentrations differed significantly between adults and calves. No differences were observed between sexes. Metal concentrations detected in the manatee bones were higher than most of those reported for bones in other marine mammals around the world. Future studies are necessary to establish whether the metal concentrations represent a risk to the health of the species.

  5. The use of total human bone marrow fraction in a direct three-dimensional expansion approach for bone tissue engineering applications: focus on angiogenesis and osteogenesis.

    Science.gov (United States)

    Guerrero, Julien; Oliveira, Hugo; Catros, Sylvain; Siadous, Robin; Derkaoui, Sidi-Mohammed; Bareille, Reine; Letourneur, Didier; Amédée, Joëlle

    2015-03-01

    Current approaches in bone tissue engineering have shown limited success, mostly owing to insufficient vascularization of the construct. A common approach consists of co-culture of endothelial cells and osteoblastic cells. This strategy uses cells from different sources and differentiation states, thus increasing the complexity upstream of a clinical application. The source of reparative cells is paramount for the success of bone tissue engineering applications. In this context, stem cells obtained from human bone marrow hold much promise. Here, we analyzed the potential of human whole bone marrow cells directly expanded in a three-dimensional (3D) polymer matrix and focused on the further characterization of this heterogeneous population and on their ability to promote angiogenesis and osteogenesis, both in vitro and in vivo, in a subcutaneous model. Cellular aggregates were formed within 24 h and over the 12-day culture period expressed endothelial and bone-specific markers and a specific junctional protein. Ectopic implantation of the tissue-engineered constructs revealed osteoid tissue and vessel formation both at the periphery and within the implant. This work sheds light on the potential clinical use of human whole bone marrow for bone regeneration strategies, focusing on a simplified approach to develop a direct 3D culture without two-dimensional isolation or expansion.

  6. Fabrication of 3D porous SF/β-TCP hybrid scaffolds for bone tissue reconstruction.

    Science.gov (United States)

    Park, Hyun Jung; Min, Kyung Dan; Lee, Min Chae; Kim, Soo Hyeon; Lee, Ok Joo; Ju, Hyung Woo; Moon, Bo Mi; Lee, Jung Min; Park, Ye Ri; Kim, Dong Wook; Jeong, Ju Yeon; Park, Chan Hum

    2016-07-01

    Bio-ceramic is a biomaterial actively studied in the field of bone tissue engineering. But, only certain ceramic materials can resolve the corrosion problem and possess the biological affinity of conventional metal biomaterials. Therefore, the recent development of composites of hybrid composites and polymers has been widely studied. In this study, we aimed to select the best scaffold of silk fibroin and β-TCP hybrid for bone tissue engineering. We fabricated three groups of scaffold such as SF (silk fibroin scaffold), GS (silk fibroin/small granule size of β-TCP scaffold) and GM (silk fibroin/medium granule size of β-TCP scaffold), and we compared the characteristics of each group. During characterization of the scaffold, we used scanning electron microscopy (SEM) and a Fourier transform infrared spectroscopy (FTIR) for structural analysis. We compared the physiological properties of the scaffold regarding the swelling ratio, water uptake and porosity. To evaluate the mechanical properties, we examined the compressive strength of the scaffold. During in vitro testing, we evaluated cell attachment and cell proliferation (CCK-8). Finally, we confirmed in vivo new bone regeneration from the implanted scaffolds using histological staining and micro-CT. From these evaluations, the fabricated scaffold demonstrated high porosity with good inter-pore connectivity, showed good biocompatibility and high compressive strength and modulus. In particular, the present study indicates that the GM scaffold using β-TCP accelerates new bone regeneration of implanted scaffolds. Accordingly, our scaffold is expected to act a useful application in the field of bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1779-1787, 2016.

  7. An audit of MRI for bone and soft-tissue tumours performed at referral centres

    Energy Technology Data Exchange (ETDEWEB)

    Saifuddin, A.; Twinn, P.; Emanuel, R.; Cannon, S.R

    2000-07-01

    AIM: Magnetic resonance imaging (MRI) is essential in the pre-operative staging of suspected primary bone and soft-tissue sarcomas. Such lesions are ideally managed in specialist centres but it is becoming increasingly common for patients to undergo MRI before referral. The aim of this study was to assess the adequacy of such studies. MATERIALS AND METHODS: Fifty patients (30 men, 20 women; mean age 39 years, range 9-89 years) were included over a 1-year period. Tumours included 31 suspected primary bone tumours and 19 soft-tissue tumours. RESULTS: The total number of sequences used was 225 (mean 4, range 2-8). Enhancement was used in 19 cases. The commonest mistake was the failure to image the whole bone for 'skip' metastases in 50% of appropriate cases (high-grade malignant lesions of bone). Reports were available in 40 cases. Specific information regarding precise intraosseous and extraosseous extent of tumour and relationship to the neurovascular bundle and adjacent joint was commonly not included. CONCLUSIONS: This audit indicates that a greater awareness is needed amongst general radiologists of the MR imaging and reporting requirements for musculoskeletal tumours. In particular, all important axial imaging is sometimes omitted. Saifuddin, A. (2000)

  8. Structure and functionalization of mesoporous bioceramics for bone tissue regeneration and local drug delivery.

    Science.gov (United States)

    Vallet-Regí, María; Izquierdo-Barba, Isabel; Colilla, Montserrat

    2012-03-28

    This review article describes the importance of structure and functionalization in the performance of mesoporous silica bioceramics for bone tissue regeneration and local drug delivery purposes. Herein, we summarize the pivotal features of mesoporous bioactive glasses, also known as 'templated glasses' (TGs), which present chemical compositions similar to those of conventional bioactive sol-gel glasses and the added value of an ordered mesopore arrangement. An in-depth study concerning the possibility of tailoring the structural and textural characteristics of TGs at the nanometric scale and their influence on bioactive behaviour is discussed. The highly ordered mesoporous arrangement of cavities allows these materials to confine drugs to be subsequently released, acting as drug delivery devices. The functionalization of mesoporous silica walls has been revealed as the cornerstone in the performance of these materials as controlled release systems. The synergy between the improved bioactive behaviour and local sustained drug release capability of mesostructured materials makes them suitable to manufacture three-dimensional macroporous scaffolds for bone tissue engineering. Finally, this review tackles the possibility of covalently grafting different osteoinductive agents to the scaffold surface that act as attracting signals for bone cells to promote the bone regeneration process.

  9. Mechanical and mineral properties of osteogenesis imperfecta human bones at the tissue level.

    Science.gov (United States)

    Imbert, Laurianne; Aurégan, Jean-Charles; Pernelle, Kélig; Hoc, Thierry

    2014-08-01

    Osteogenesis imperfecta (OI) is a genetic disorder characterized by an increase in bone fragility on the macroscopic scale, but few data are available to describe the mechanisms involved on the tissue scale and the possible correlations between these scales. To better understand the effects of OI on the properties of human bone, we studied the mechanical and chemical properties of eight bone samples from children suffering from OI and compared them to the properties of three controls. High-resolution computed tomography, nanoindentation and Raman microspectroscopy were used to assess those properties. A higher tissue mineral density was found for OI bone (1.131 gHA/cm3 vs. 1.032 gHA/cm3, p=0.032), along with a lower Young's modulus (17.6 GPa vs. 20.5 GPa, p=0.024). Obviously, the mutation-induced collagen defects alter the collagen matrix, thereby affecting the mineralization. Raman spectroscopy showed that the mineral-to-matrix ratio was higher in the OI samples, while the crystallinity was lower, suggesting that the mineral crystals were smaller but more abundant in the case of OI. This change in crystal size, distribution and composition contributes to the observed decrease in mechanical strength.

  10. FAT EMBOLISM SYNDROME WITHOUT OBJECTIVE EVIDENCE OF BONE OR SOFT TISSUE INJURY

    Directory of Open Access Journals (Sweden)

    Amitabh Das

    2014-10-01

    Full Text Available Fat embolism syndrome (FES, without evidence of bone or soft tissue injury is uncommon, and in absence of validated diagnostic criteria, its diagnosis is mainly dependent on treating clinician, who should have high index of suspicion. Treatment is predominantly supportive, and apart from some mortality, recovery is generally seen. Present article is a case report of a boy who suffered blunt injury due to fall from height, had no objective evidence of bone or soft tissue injury, but diagnosed as a case of fat embolism syndrome, using Gurd-Wilson and Schonfeld’s criteria, treated by pulmonary support and aggressive resuscitation, but he died after 4 days of admission to hospital.

  11. Lipidomic Profiling of Mastoid Bone and Tissue from Patients with Chronic Otomastoiditis

    Directory of Open Access Journals (Sweden)

    Fazlollahi, Farbod

    2015-01-01

    Full Text Available Introduction Chronic otomastoiditis causes pain, otorrhea, and hearing loss resulting from the growth of tissue within the normally hollow mastoid cavity. Objectives In this report, we used a lipidomics approach to profile major mastoid bone and tissue lipids from patients with and without otomastoiditis. Methods The bone dust created during mastoidectomy, as well as the mastoid tissue, was analyzed from seven patients. Bone dust was also collected and analyzed in an additional four otologic cases (parotidectomy requiring mastoidectomy. Samples were subjected to a modified Bligh/Dyer lipid extraction, then high-performance thin-layer chromatography (HPTLC, combined gas chromatography/electron impact-mass spectrometry (GC/EI-MS, and flow-injection/electrospray ionization-tandem mass spectrometry (FI/ESI-MSMS. Data were analyzed for identification and profiling of major lipid components. Results HPTLC revealed the presence of various lipid classes, including phosphatidylcholines, cholesterol, and triacylglycerols. GC/EI-MS analysis revealed the presence of cholesterol and several fatty acids. FI/ESI-MSMS analysis revealed a host of phosphatidylcholines, phosphatidylethanolamines, and cholesteryl esters. Conclusion We used a lipidomics approach to develop an efficient (both in time and tissue amount methodology for analysis of these tissues, identify the most abundant and common lipid species, and create a base of knowledge from which more focused endeavors in biomarker discovery can emerge. In an effort toward improved patient categorization and individualized intervention, the ultimate goal of this work is to correlate these lipid molecules to disease state and progression. This is the first reported study of its kind on these tissues.

  12. On ultrasound waves guided by bones with coupled soft tissues: a mechanism study and in vitro calibration.

    Science.gov (United States)

    Chen, Jiangang; Su, Zhongqing

    2014-07-01

    The influence of soft tissues coupled with cortical bones on precision of quantitative ultrasound (QUS) has been an issue in the clinical bone assessment in conjunction with the use of ultrasound. In this study, the effect arising from soft tissues on propagation characteristics of guided ultrasound waves in bones was investigated using tubular Sawbones phantoms covered with a layer of mimicked soft tissue of different thicknesses and elastic moduli, and an in vitro porcine femur in terms of the axial transmission measurement. Results revealed that presence of soft tissues can exert significant influence on the propagation of ultrasound waves in bones, leading to reduced propagation velocities and attenuated wave magnitudes compared with the counterparts in a free bone in the absence of soft tissues. However such an effect is not phenomenally dependent on the variations in thickness and elastic modulus of the coupled soft tissues, making it possible to compensate for the coupling effect regardless of the difference in properties of the soft tissues. Based on an in vitro calibration, this study proposed quantitative compensation for the effect of soft tissues on ultrasound waves in bones, facilitating development of high-precision QUS.

  13. Injectable in situ-forming pH/thermo-sensitive hydrogel for bone tissue engineering.

    Science.gov (United States)

    Kim, Hea Kyung; Shim, Woo Sun; Kim, Sung Eun; Lee, Kweon-Haeng; Kang, Eunah; Kim, Jong-Ho; Kim, Kwangmeyung; Kwon, Ick Chan; Lee, Doo Sung

    2009-04-01

    We developed a novel pH- and thermo-sensitive hydrogel as a scaffold for autologous bone tissue engineering. We synthesized this polymer by adding pH-sensitive sulfamethazine oligomers (SMOs) to both ends of a thermo-sensitive poly(epsilon-caprolactone-co-lactide)-poly(ethylene glycol)-poly(epsilon-caprolactone-co-lactide) (PCLA-PEG-PCLA) block copolymer, yielding a pH/thermo-sensitive SMO-PCLA-PEG-PCLA-SMO block copolymer. The synthesized block copolymer solution rapidly formed a stable gel under physiological conditions (pH 7.4 and 37 degrees C), whereas it formed a sol at pH 8.0 and 37 degrees C, making it injectable. This pH/thermo-sensitive hydrogel exhibited high biocompatibility in a Dulbecco's modified Eagle's medium extract test. Under physiological conditions, the hydrogel easily encapsulated human mesenchymal stem cells (hMSCs) and recombinant human bone morphogenetic protein-2 (rhBMP-2), with encapsulating efficiencies of about 90% and 85%, respectively. To assay for ectopic bone formation in vivo, we subcutaneously injected a polymer solution containing hMSCs and rhBMP-2 into the back of mice, after which we could observe hMSC differentiation for up to 7 weeks. Histological studies revealed mineralized tissue formation and high levels of alkaline phosphatase activity in the mineralized tissue. Therefore, this pH/thermo-sensitive SMO-PCLA-PEG-PCLA-SMO block copolymer demonstrated potential as an injectable scaffold for bone tissue engineering, with in situ formation capabilities.

  14. Using absorbable collagen membranes for guided tissue regeneration, guided bone regeneration, and to treat gingival recession.

    Science.gov (United States)

    Wang, H L; Carroll, W J

    2000-05-01

    This article reviews the role of barrier membranes in guided tissue regeneration (GTR) and guided bone regeneration (GBR), including the advantages of using absorbable barrier membranes in GTR and GBR and the unique properties of collagen membranes. The indications and contraindications for using collagen membranes for these procedures are examined, and successful cases are presented. Finally, the role of collagen membranes in the future of regenerative therapy is considered.

  15. Biomineralization of a Self-Assembled Extracellular Matrix for Bone Tissue Engineering

    Science.gov (United States)

    Meng, Yizhi; DiMasi, Elaine; Ba, Xiaolan; Rafailovich, Miriam; Pernodet, Nadine

    2009-01-01

    Understanding how biomineralization occurs in the extracellular matrix (ECM) of bone cells is crucial to the understanding of bone formation and the development of a successfully engineered bone tissue scaffold. It is still unclear how ECM mechanical properties affect protein-mineral interactions in early stages of bone mineralization. We investigated the longitudinal mineralization properties of MC3T3-E1 cells and the elastic modulus of their ECM using shear modulation force microscopy, synchrotron grazing incidence X-ray diffraction (GIXD), scanning electron microscopy, energy dispersive X-ray spectroscopy, and confocal laser scanning microscopy (CLSM). The elastic modulus of the ECM fibers underwent significant changes for the mineralizing cells, which were not observed in the nonmineralizing cells. On substrates conducive to ECM network production, the elastic modulus of mineralizing cells increased at time points corresponding to mineral production, whereas that of the nonmineralizing cells did not vary over time. The presence of hydroxyapatite in mineralizing cells and the absence thereof in the nonmineralizing ones were confirmed by GIXD, and CLSM showed that a restructuring of actin occurred only for mineral-producing cells. These results show that the correct and complete development of the ECM network is required for osteoblasts to mineralize. This in turn requires a suitably prepared synthetic substrate for bone development to succeed in vitro. PMID:18759666

  16. Biomineralization of a Self-Assembled Extracellular Matrix for Bone Tissue Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Yizhi, M.; Yi-Xian, Q; DiMasi, E; Xiaolan, B; Rafailovich, M; Pernodet, N

    2009-01-01

    Understanding how biomineralization occurs in the extracellular matrix (ECM) of bone cells is crucial to the understanding of bone formation and the development of a successfully engineered bone tissue scaffold. It is still unclear how ECM mechanical properties affect protein-mineral interactions in early stages of bone mineralization. We investigated the longitudinal mineralization properties of MC3T3-E1 cells and the elastic modulus of their ECM using shear modulation force microscopy, synchrotron grazing incidence X-ray diffraction (GIXD), scanning electron microscopy, energy dispersive X-ray spectroscopy, and confocal laser scanning microscopy (CLSM). The elastic modulus of the ECM fibers underwent significant changes for the mineralizing cells, which were not observed in the nonmineralizing cells. On substrates conducive to ECM network production, the elastic modulus of mineralizing cells increased at time points corresponding to mineral production, whereas that of the nonmineralizing cells did not vary over time. The presence of hydroxyapatite in mineralizing cells and the absence thereof in the nonmineralizing ones were confirmed by GIXD, and CLSM showed that a restructuring of actin occurred only for mineral-producing cells. These results show that the correct and complete development of the ECM network is required for osteoblasts to mineralize. This in turn requires a suitably prepared synthetic substrate for bone development to succeed in vitro.

  17. Biodegradable nanofibers-reinforced microfibrous composite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Martins, Albino; Pinho, Elisabete D; Correlo, Vítor M; Faria, Susana; Marques, Alexandra P; Reis, Rui L; Neves, Nuno M

    2010-12-01

    Native bone extracellular matrix (ECM) is a complex hierarchical fibrous composite structure, resulting from the assembling of collagen fibrils at several length scales, ranging from the macro to the nanoscale. The combination of nanofibers within microfibers after conventional reinforcement methodologies seems to be a feasible solution to the rational design of highly functional synthetic ECM substitutes. The present work aims at the development of bone ECM inspired structures, conjugating electrospun chitosan (Cht) nanofibers within biodegradable polymeric microfibers [poly(butylene succinate)-PBS and PBS/Cht], assembled in a fiber mesh structure. The nanofibers-reinforced composite fiber mesh scaffolds were seeded with human bone marrow mesenchymal stem cells (hBMSCs) and cultured under osteogenic differentiation conditions. These nanofibers-reinforced composite scaffolds sustained ECM deposition and mineralization, mainly in the PBS/Cht-based fiber meshes, as depicted by the increased amount of calcium phosphates produced by the osteogenic differentiated hBMSCs. The osteogenic genotype of the cultured hBMSCs was confirmed by the expression of osteoblastic genes, namely Alkaline Phosphatase, Osteopontin, Bone Sialoprotein and Osteocalcin, and the transcription factors Runx2 and Osterix, all involved in different stages of the osteogenesis. These data represent the first report on the biological functionality of nanofibers-reinforced composite scaffolds, envisaging the applicability of the developed structures for bone tissue engineering.

  18. Detection of benzodiazepines in different tissues, including bone, using a quantitative ELISA assay.

    Science.gov (United States)

    Gorczynski, L Y; Melbye, F J

    2001-07-01

    Benzodiazepines were analyzed in different tissue samples, including hone, by ELISA. The sensitivity of detection for different benzodiazepines was consistent with the manufacturer's reports of the cross reactivities of the antibodies used, with the greatest sensitivity for midazolam and the least for diazepam; in addition the pharmacokinetics was consistent with the known duration of action of the different benzodiazepines, with midazolam cleared rapidly, and diazepam slowly. Following intramuscular injection of 300 microg of midazolam at 16 h intervals for ten days, the drug was detectable in bone tissue samples obtained from skeletonized remains buried in soil at room temperature for three weeks.

  19. Natural-based nanocomposites for bone tissue engineering and regenerative medicine: a review.

    Science.gov (United States)

    Pina, Sandra; Oliveira, Joaquim M; Reis, Rui L

    2015-02-18

    Tissue engineering and regenerative medicine has been providing exciting technologies for the development of functional substitutes aimed to repair and regenerate damaged tissues and organs. Inspired by the hierarchical nature of bone, nanostructured biomaterials are gaining a singular attention for tissue engineering, owing their ability to promote cell adhesion and proliferation, and hence new bone growth, compared with conventional microsized materials. Of particular interest are nanocomposites involving biopolymeric matrices and bioactive nanosized fillers. Biodegradability, high mechanical strength, and osteointegration and formation of ligamentous tissue are properties required for such materials. Biopolymers are advantageous due to their similarities with extracellular matrices, specific degradation rates, and good biological performance. By its turn, calcium phosphates possess favorable osteoconductivity, resorbability, and biocompatibility. Herein, an overview on the available natural polymer/calcium phosphate nanocomposite materials, their design, and properties is presented. Scaffolds, hydrogels, and fibers as biomimetic strategies for tissue engineering, and processing methodologies are described. The specific biological properties of the nanocomposites, as well as their interaction with cells, including the use of bioactive molecules, are highlighted. Nanocomposites in vivo studies using animal models are also reviewed and discussed.

  20. Changes in the population of perivascular cells in the bone tissue remodeling zones under microgravity

    Science.gov (United States)

    Katkova, Olena; Rodionova, Natalia; Shevel, Ivan

    2016-07-01

    cells reveal signs of destruction. Thus it was found that number of the alkaline phosphatase containing cells (i.e. osteogenic cells) declines in perivascular cells population. It is one of the mechanisms of the osteogenic process decrease of intensity in bones because of lessening support loading on the bone skeleton. In the adaptive remodeling zones of bone tissue (near the vascular canals) in experiments fibroblasts and fibrosis zones were found - areas filled with non-mineralized collagen fibrils on the bones surfaces. Hence it should be considered that decrease (removal) of support loading slows down osteogenic differentiation of the part of perivascular cells and stimulates differentiation of the fibroblast cells. Obtained data is considered as one of the cellular mechanisms of the adaptive reactions development in spongy bone under microgravity which could lead to the bone mass loss.

  1. Three-dimensional fiber deposition of cell-laden, viable, patterned constructs for bone tissue printing.

    Science.gov (United States)

    Fedorovich, Natalja E; De Wijn, Joost R; Verbout, Abraham J; Alblas, Jacqueline; Dhert, Wouter J A

    2008-01-01

    Organ or tissue printing, a novel approach in tissue engineering, creates layered, cell-laden hydrogel scaffolds with a defined three-dimensional (3D) structure and organized cell placement. In applying the concept of tissue printing for the development of vascularized bone grafts, the primary focus lies on combining endothelial progenitors and bone marrow stromal cells (BMSCs). Here we characterize the applicability of 3D fiber deposition with a plotting device, Bioplotter, for the fabrication of spatially organized, cell-laden hydrogel constructs. The viability of printed BMSCs was studied in time, in several hydrogels, and extruded from different needle diameters. Our findings indicate that cells survive the extrusion and that their subsequent viability was not different from that of unprinted cells. The applied extrusion conditions did not affect cell survival, and BMSCs could subsequently differentiate along the osteoblast lineage. Furthermore, we were able to combine two distinct cell populations within a single scaffold by exchanging the printing syringe during deposition, indicating that this 3D fiber deposition system is suited for the development of bone grafts containing multiple cell types.

  2. Small intestine submucosa sponge for in vivo support of tissue-engineered bone formation in the presence of rat bone marrow stem cells.

    Science.gov (United States)

    Kim, Kyung Sook; Lee, Ju Young; Kang, Yun Mi; Kim, E Sle; Kim, Gyeong Hae; Rhee, Sang Dal; Cheon, Hyae Gyeong; Kim, Jae Ho; Min, Byoung-Hyun; Lee, Hai Bang; Kim, Moon Suk

    2010-02-01

    The aim of the current study was to visualize new bone formed in vivo on a small intestine submucosa (SIS) sponge used as a tissue-engineered scaffold for the repair of damaged bone. The SIS sponge provided a three-dimensional pore structure, and supported good attachment and viability of rat bone marrow stem cells (rBMSCs). To examine bone regeneration, we prepared full-thickness bilateral bone defects in the rat crania, and then treated the defects with an implanted SIS sponge or PGA mesh without or with rBMSCs, or left the defects untreated. Bone defects were evaluated by micro-CT and histologically after 2 and 4 weeks. Micro-CT demonstrated a trend toward a decrease in bone void in both the SIS sponge and SIS sponge/rBMSCs groups compared to the control and PGA mesh groups. At 4 weeks, bone formation in defects containing SIS sponge/rBMSCs was significantly greater than in all other groups. A histological analysis after 2 and 4 weeks of implantation showed localized collagen and osteocalcin deposition on SIS sponges and SIS sponges with rBMSCs. These in vivo results indicate that the SIS sponge, implanted at bone-removal defects, facilitated bone regeneration.

  3. Altered distributions of bone tissue mineral and collagen properties in women with fragility fractures.

    Science.gov (United States)

    Wang, Zhen Xiang; Lloyd, Ashley A; Burket, Jayme C; Gourion-Arsiquaud, Samuel; Donnelly, Eve

    2016-03-01

    Heterogeneity of bone tissue properties is emerging as a potential indicator of altered bone quality in pathologic tissue. The objective of this study was to compare the distributions of tissue properties in women with and without histories of fragility fractures using Fourier transform infrared (FTIR) imaging. We extended a prior study that examined the relationship of the mean FTIR properties to fracture risk by analyzing in detail the widths and the tails of the distributions of FTIR properties in biopsies from fracture and non-fracture cohorts. The mineral and matrix properties of cortical and trabecular iliac crest tissue were compared in biopsies from women with a history of fragility fracture (+Fx; n=21, age: mean 54±SD 15y) and with no history of fragility fracture (-Fx; n=12, age: 57±5y). A subset of the patients included in the -Fx group were taking estrogen-plus-progestin hormone replacement therapy (HRT) (-Fx+HRT n=8, age: 58±5y) and were analyzed separately from patients with no history of HRT (-Fx-HRT n=4, age: 56±7y). When the FTIR parameter mean values were examined by treatment group, the trabecular tissue of -Fx-HRT patients had a lower mineral:matrix ratio (M:M) and collagen maturity (XLR) than that of -Fx+HRT patients (-22% M:M, -18% XLR) and +Fx patients (-17% M:M, -18% XLR). Across multiple FTIR parameters, tissue from the -Fx-HRT group had smaller low-tail (5th percentile) values than that from the -Fx+HRT or +Fx groups. In trabecular collagen maturity and crystallinity (XST), the -Fx-HRT group had smaller low-tail values than those in the -Fx+HRT group (-16% XLR, -5% XST) and the +Fx group (-17% XLR, -7% XST). The relatively low values of trabecular mineral:matrix ratio and collagen maturity and smaller low-tail values of collagen maturity and crystallinity observed in the -Fx-HRT group are characteristic of younger tissue. Taken together, our data suggest that the presence of newly formed tissue that includes small/imperfect crystals

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

    Science.gov (United States)

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

    2013-01-01

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

  5. Influence of bone and soft-tissue operations on serum concentrations of growth hormone, somatomedin C and alkaline phosphatase.

    Science.gov (United States)

    Casser, H R; Zilkens, K W; Forst, R; Brüggemann, A

    1990-01-01

    After animal experiments suggested there was an interaction between growth hormone and bone healing, our aim in this paper was to ascertain whether there were any changes or possible interaction between the serum level of growth hormone, somatomedin C and alkaline phosphatase while a fractured bone was healing. To this end, the serum concentrations of growth hormone, somatomedin C, alkaline phosphatase and calcium were ascertained both pre- and post-operatively in two groups of patients--one with bone operations, the other with soft-tissue operations--and the results were compared. Comparing the groups, we found that after bone operations there was no increase in the serum level of growth hormone, nor of somatomedin C. An increase would have implied that these two hormones are directly involved in bone regeneration. There was no change in the serum level of alkaline phosphatase or calcium after either bone or soft-tissue operations.

  6. [State of the microscopic and crystalline structures, the microhardness and mineral saturation of human bone tissue after prolonged space flight].

    Science.gov (United States)

    Gazenko, O G; Prokhonchukov, A A; Panikarovskiĭ, V V; Tigranian, R A; Kolesnik, A G

    1977-01-01

    The bone tissue removed by autopsy from the crewmembers of the orbital station Salyut-1 after their 23-day space flight was investigated histologically, crystallographically, biophysically and biochemically. The comprehensive studies showed good correlation of the parameters studied. The microscopic and crystalline structures of bone tissue of every skeletal bone tested (ox calcis, frmoral epiphysis and diaphysis, vertebrae, ribs, sternum) did not differ from the normal. The data were in agreement with the parameters of bone microhardness and mineralization which also remained within the normal limits. No pathological changes in the above parameters were noted. Greater packing of the crystal lattice, increased microhardness and mineralization of bone tissue can be attributed to the effect of exercises.

  7. The relationships among total body fat, bone mineral content and bone marrow adipose tissue in early-pubertal girls.

    Science.gov (United States)

    L Newton, Anna; J Hanks, Lynae; Davis, Michelle; Casazza, Krista

    2013-01-01

    Investigation of the physiologic relevance of bone marrow adipose tissue (BMAT) during growth may promote understanding of the bone-fat axis and confluence with metabolic factors. The objective of this pilot investigation was two-fold: (1) to evaluate the relationships among total body fat, bone mineral content (BMC) and femoral BMAT during childhood and underlying metabolic determinants and (2) to determine if the relationships differ by race. Participants included white and non-Hispanic black girls (n=59) ages 4-10 years. Femoral BMAT volume was measured by magnetic resonance imaging, BMC and body fat by dual-energy X-ray absorptiometry. Metabolic parameters were assessed in the fasted state. Total fat and BMC were positively associated with BMAT; however, simultaneous inclusion of BMC and body fat in the statistical model attenuated the association between BMC and BMAT. Differences in BMAT volume were observed, non-Hispanic black girls exhibiting marginally greater BMAT at age eight (P=0.05) and white girls exhibiting greater BMAT at age ten (PBMAT and leptin (P=0.02) and adiponectin (P=0.002) in white girls while BMAT and insulin were inversely related in non-Hispanic black girls (P=0.008). Our findings revealed a positive relationship between BMAT, body fat and BMC, although body fat, respective to leptin, contributed partly to the relationship between BMAT and BMC. Despite large differences in total fat between non-Hispanic black and white, the relationship between BMAT and BMC was similar to white girls. However, this relationship appeared to be impacted through different mechanisms according to race.

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

    Directory of Open Access Journals (Sweden)

    Marek Tomaszewski

    2012-10-01

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

  9. Characterization of an ovine bilateral critical sized bone defect iliac wing model to examine treatment modalities based on bone tissue engineering.

    Science.gov (United States)

    Lansdowne, Jennifer L; Devine, Declan; Eberli, Ursula; Emans, Pieter; Welting, Tim J M; Odekerken, Jim C E; Schiuma, Damiano; Thalhauser, Martin; Bouré, Ludovic; Zeiter, Stephan

    2014-01-01

    Critical sized bone defect (CSBD) animal models are used to evaluate and confirm efficacy and potency of new treatment modalities based on bone tissue engineering before the latter can be applied in clinical practice. In this study, a bilateral CSBD model in the iliac wings of sheep is described in detail. To demonstrate that this is a large animal CSBD model in sheep, bone healing within the defect left empty (negative control) or filled with autologous corticocancellous bone graft (clinical gold standard, positive control) was assessed using micro-CT, histology, histomorphometric, and fluorochrome analysis. After three months, new bone into the defect site was formed across the whole defect in the positive controls but limited to the edge of the defects in the negative controls. Bone volume in the positive controls was statistically higher than in the negative controls, with the latter having less than 10% new bone growth. There were no intraoperative or postoperative complications. The model described here represents a reliable and reproducible bilateral CSBD in sheep with low morbidity that can be used for in vivo evaluation of new treatment modalities based on bone tissue engineering.

  10. Characterization of an Ovine Bilateral Critical Sized Bone Defect Iliac Wing Model to Examine Treatment Modalities Based on Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Jennifer L. Lansdowne

    2014-01-01

    Full Text Available Critical sized bone defect (CSBD animal models are used to evaluate and confirm efficacy and potency of new treatment modalities based on bone tissue engineering before the latter can be applied in clinical practice. In this study, a bilateral CSBD model in the iliac wings of sheep is described in detail. To demonstrate that this is a large animal CSBD model in sheep, bone healing within the defect left empty (negative control or filled with autologous corticocancellous bone graft (clinical gold standard, positive control was assessed using micro-CT, histology, histomorphometric, and fluorochrome analysis. After three months, new bone into the defect site was formed across the whole defect in the positive controls but limited to the edge of the defects in the negative controls. Bone volume in the positive controls was statistically higher than in the negative controls, with the latter having less than 10% new bone growth. There were no intraoperative or postoperative complications. The model described here represents a reliable and reproducible bilateral CSBD in sheep with low morbidity that can be used for in vivo evaluation of new treatment modalities based on bone tissue engineering.

  11. Biodegradable poly(epsilon-caprolactone) nanowires for bone tissue engineering applications.

    Science.gov (United States)

    Porter, Joshua R; Henson, Andrew; Popat, Ketul C

    2009-02-01

    Critical-sized defects in bone, whether caused by cancer tumor resection, trauma, or selective surgery have in many cases presented insurmountable challenges to the current gold-standard treatment for bone repair. The primary purpose of a tissue-engineered scaffold is to incite and promote the natural healing process of bone, which does not occur in critical-sized defects. In this work, a solvent-free template synthesis technique was utilized to fabricate uniform arrays of substrate-bound poly(epsilon-caprolactone) (PCL) nanowires. Biodegradation of PCL nanowire surfaces was characterized using scanning electron microscopy (SEM) and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. Rat bone marrow-derived mesenchymal stem cells (MSCs) were employed to assess short-term biocompatibility and long-term bioactivity of nanowire surfaces. Short-term cell studies indicated that PCL nanowire surfaces supported enhanced cell adhesion and viability compared with control surfaces. MSCs seeded on nanowire surfaces also displayed increased levels of alkaline phosphatase (ALP) after 1, 2, and 3 weeks in culture. Calcium-phosphate mineralization was substantially accelerated on nanowire surfaces compared to control surfaces as indicated through calcium staining, von Kossa staining, SEM, and electron dispersive spectroscopy (EDS). Increased levels of inter- and extracellular levels of osteocalcin and osteopontin were observed on nanowire surfaces using immunofluorescence techniques after 3 weeks of culture. Considering the simplicity of the presented fabrication technique, capacity for solvent-free encapsulation of bioactive molecules or particles, and enhanced MSC performance on nanowire surfaces, this work presents an excellent foundation for the development of 3-D scaffolds for bone tissue regeneration.

  12. Effective combination of aligned nanocomposite nanofibers and human unrestricted somatic stem cells for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    Behnaz BAKHSHANDEH; Masoud SOLEIMANI; Nasser GHAEMI; Iman SHABANI

    2011-01-01

    Aim: Bioartificial bone tissue engineering is an increasingly popular technique to solve bone defect challenges. This study aimed to investigate the interactions between matrix composition and appropriate cell type, focusing on hydroxyapatite (HA), to achieve a more effective combination for bone regeneration.Methods: Human unrestricted somatic stem cells (USSCs) were isolated from placental cord blood. The cellular and molecular events during the osteo-induction of USSCs were evaluated for 21 d under the following conditions: (1) in basal culture, (2) supplemented with hydroxyapatite nanoparticle (nHA) suspension, and (3) seeded on electrospun aligned nanoflbrous poly-ε-caprolactone/poly-L-lactic acid/nHA (PCL/PLLA/nHA) scaffolds. The scaffolds were characterized using scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and tensile test.Results: Maintenance of USSCs for 21 d in basal or osteogenic culture resulted in significant increase in osteoblast differentiation. With nHA suspension, even soluble osteo-inductive additives were ineffective, probably due to induced apoptosis of the cells. In con-trast to the hindrance of proliferation by nHA suspension, the scaffolds improved cell growth. The scaffolds mimic the nanostructure of natural bone matrix with the combination of PLLA/PCL (organic phase) and HA (inorganic phase) offering a favorable surface topogra-phy, which was demonstrated to possess suitable properties for supporting USSCs. Quantitative measurement of osteogenic markers, enzymatic activity and mineralization indicated that the scaffolds did not disturb, but enhanced the osteogenic potential of USSCs.Moreover, the alignment of the fibers led to cell orientation during cell growth.Conclusion: The results demonstrated the synergism of PCL/PLLA/nHA nanoflbrous scaffolds and USSCs in the augmentation of osteo-genic differentiation. Thus, nHA grafted into PCI./PLLA scaffolds can be a suitable choice for bone tissue

  13. Geometry Design Optimization of Functionally Graded Scaffolds for Bone Tissue Engineering: A Mechanobiological Approach.

    Directory of Open Access Journals (Sweden)

    Antonio Boccaccio

    Full Text Available Functionally Graded Scaffolds (FGSs are porous biomaterials where porosity changes in space with a specific gradient. In spite of their wide use in bone tissue engineering, possible models that relate the scaffold gradient to the mechanical and biological requirements for the regeneration of the bony tissue are currently missing. In this study we attempt to bridge the gap by developing a mechanobiology-based optimization algorithm aimed to determine the optimal graded porosity distribution in FGSs. The algorithm combines the parametric finite element model of a FGS, a computational mechano-regulation model and a numerical optimization routine. For assigned boundary and loading conditions, the algorithm builds iteratively different scaffold geometry configurations with different porosity distributions until the best microstructure geometry is reached, i.e. the geometry that allows the amount of bone formation to be maximized. We tested different porosity distribution laws, loading conditions and scaffold Young's modulus values. For each combination of these variables, the explicit equation of the porosity distribution law-i.e the law that describes the pore dimensions in function of the spatial coordinates-was determined that allows the highest amounts of bone to be generated. The results show that the loading conditions affect significantly the optimal porosity distribution. For a pure compression loading, it was found that the pore dimensions are almost constant throughout the entire scaffold and using a FGS allows the formation of amounts of bone slightly larger than those obtainable with a homogeneous porosity scaffold. For a pure shear loading, instead, FGSs allow to significantly increase the bone formation compared to a homogeneous porosity scaffolds. Although experimental data is still necessary to properly relate the mechanical/biological environment to the scaffold microstructure, this model represents an important step towards

  14. Cortical bone tissue resists fatigue fracture by deceleration and arrest of microcrack growth.

    Science.gov (United States)

    Akkus, O; Rimnac, C M

    2001-06-01

    Knowledge of kinetics of fatigue crack growth of microcracks is important so as to understand the dynamics of bone adaptation, remodeling, and the etiology of fatigue-based failures of cortical bone tissue. In this respect, theoretical models (Taylor, J. Biomech., 31 (1998) 587-592; Taylor and Prendergast, Proc. Instn. Mech. Engrs. Part H 211 (1997) 369-375) of microcrack growth in cortical bone have predicted a decreasing microcrack growth rate with increasing microcrack length. However, these predictions have not been observed directly. This study investigated microcrack growth and arrest through observations of surface microcracks during cyclic loading (R=0.1, 50-80MPa) of human femoral cortical bone (male, n=4, age range: 37-40yr) utilizing a video microscopy system. The change in crack length and orientation of eight surface microcracks were measured with the number of fatigue cycles from four specimens. At the applied cyclic stresses, the microcracks propagated and arrested in generally less than 10,000 cycles. The fatigue crack growth rate of all microcracks decreased with increasing crack length following initial identification, consistent with theoretical predictions. The growth rate of the microcracks was observed to be in the range of 5x10(-5) to 5x10(-7)mmcycle(-1). In addition, many of the microcracks were observed not to grow beyond 150 microm and a cyclic stress intensity factor of 0.5MNm(-3/2). The results of this study suggest that cortical bone tissue may resist fracture at the microscale by deceleration of fatigue crack growth and arrest of microcracks.

  15. Sequential Fluorescent Labeling Observation of Maxillary Sinus Augmentation by a Tissue-engineered Bone Complex in Canine Model

    Institute of Scientific and Technical Information of China (English)

    Xin-quan Jiang; Shao-yi Wang; Jun Zhao; Xiu-li Zhang; Zhi-yuan Zhang

    2009-01-01

    Aim To evaluate the effects of maxillary sinus floor elevation by a tissue-engineered bone complex of β-tricalcium phosphate (β-TCP) and autologous osteoblasts in dogs. Methodology Autologous osteoblasts from adult Beagle dogs were cultured in vitro. They were further combined with β-TCP to construct the tissue-engineered bone complex. 12 cases of maxillary sinus floor elevation surgery were made bilaterally in 6 animals and randomly repaired with the following 3 groups of materials: Group A (osteoblasts/β-TCP); Group B (β-TCP); Group C (autogenous bone) (n-4 per group). A polychrome sequential fluorescent labeling was performed post-operatively and the animals were sacrificed 24 weeks after operation for histological observation.Results Our results showed that autologous osteoblasts were successfully expanded and the osteoblastic phenoltypes were confirmed by ALP and Alizarin red staining. The cells could attach and proliferate well on the surface of the β-TCP scaffold. The fluorescent and histological observation showed that the tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than β-TCP along or even autologous bone. It had also maximally maintained the elevated sinus height than both control groups. Conclusion Porous β-TCP has served as a good scaffold for autologous osteoblasts seeding. The tissue-engineered bone complex with β-TCP and autologous osteoblasts might be a better alternative to autologous bone for the clinical edentulous maxillary sinus augmentation.

  16. Towards injectable cell-based tissue-engineered bone : The effect of different calcium phosphate microparticles and pre-culturing

    NARCIS (Netherlands)

    Persson, C; Johansson, G; Dhert, WJA; Kruyt, Moyo C.; de Bruijn, Joost D.

    2006-01-01

    Bone tissue engineering by combining bone marrow stromal cells (BMSCs) with a porous scaffold is a promising technology. Current major challenges are to upscale the technique for clinical application and to improve the handling characteristics. With respect to minimal invasive surgery, moldable and/

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-01

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

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

    Science.gov (United States)

    Ogunsalu, C

    2005-09-01

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

  19. A Review of Injectable Polymeric Hydrogel Systems for Application in Bone Tissue Engineering.

    Science.gov (United States)

    Kondiah, Pariksha J; Choonara, Yahya E; Kondiah, Pierre P D; Marimuthu, Thashree; Kumar, Pradeep; du Toit, Lisa C; Pillay, Viness

    2016-11-21

    Biodegradable, stimuli-responsive polymers are essential platforms in the field of drug delivery and injectable biomaterials for application of bone tissue engineering. Various thermo-responsive hydrogels display water-based homogenous properties to encapsulate, manipulate and transfer its contents to the surrounding tissue, in the least invasive manner. The success of bioengineered injectable tissue modified delivery systems depends significantly on their chemical, physical and biological properties. Irrespective of shape and defect geometry, injectable therapy has an unparalleled advantage in which intricate therapy sites can be effortlessly targeted with minimally invasive procedures. Using material testing, it was found that properties of stimuli-responsive hydrogel systems enhance cellular responses and cell distribution at any site prior to the transitional phase leading to gelation. The substantially hydrated nature allows significant simulation of the extracellular matrix (ECM), due to its similar structural properties. Significant current research strategies have been identified and reported to date by various institutions, with particular attention to thermo-responsive hydrogel delivery systems, and their pertinent focus for bone tissue engineering. Research on future perspective studies which have been proposed for evaluation, have also been reported in this review, directing considerable attention to the modification of delivering natural and synthetic polymers, to improve their biocompatibility and mechanical properties.

  20. Kartogenin induces cartilage-like tissue formation in tendon-bone junction

    Institute of Scientific and Technical Information of China (English)

    Jianying Zhang; James H-C Wang

    2014-01-01

    Tendon-bone junctions (TBJs) are frequently injured, especially in athletic settings. Healing of TBJ injuries is slow and is often repaired with scar tissue formation that compromises normal function. This study explored the feasibility of using kartogenin (KGN), a biocompound, to enhance the healing of injured TBJs. We first determined the effects of KGN on the proliferation and chondrogenic differentiation of rabbit bone marrow stromal cells (BMSCs) and patellar tendon stem/progenitor cells (PTSCs) in vitro. KGN enhanced cell proliferation in both cell types in a concentration-dependent manner and induced chondrogenic differentiation of stem cells, as demonstrated by high expression levels of chondrogenic markers aggrecan, collagen II and Sox-9. Besides, KGN induced the formation of cartilage-like tissues in cell cultures, as observed through the staining of abundant proteoglycans, collagen II and osteocalcin. When injected into intact rat patellar tendons in vivo, KGN induced cartilage-like tissue formation in the injected area. Similarly, when KGN was injected into experimentally injured rat Achilles TBJs, wound healing in the TBJs was enhanced, as evidenced by the formation of extensive cartilage-like tissues. These results suggest that KGN may be used as an effective cell-free clinical therapy to enhance the healing of injured TBJs.

  1. Preparation of poly(ethylene glycol/polylactide hybrid fibrous scaffolds for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Ni P

    2011-11-01

    Full Text Available PeiYan Ni, ShaoZhi Fu, Min Fan, Gang Guo, Shuai Shi, JinRong Peng, Feng Luo, ZhiYong QianState Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of ChinaAbstract: Polylactide (PLA electrospun fibers have been reported as a scaffold for bone tissue engineering application, however, the great hydrophobicity limits its broad application. In this study, the hybrid amphiphilic poly(ethylene glycol (PEG/hydrophobic PLA fibrous scaffolds exhibited improved morphology with regular and continuous fibers compared to corresponding blank PLA fiber mats. The prepared PEG/PLA fibrous scaffolds favored mesenchymal stem cell (MSC attachment and proliferation by providing an interconnected porous extracellular environment. Meanwhile, MSCs can penetrate into the fibrous scaffold through the interstitial pores and integrate well with the surrounding fibers, which is very important for favorable application in tissue engineering. More importantly, the electrospun hybrid PEG/PLA fibrous scaffolds can enhance MSCs to differentiate into bone-associated cells by comprehensively evaluating the representative markers of the osteogenic procedure with messenger ribonucleic acid quantitation and protein analysis. MSCs on the PEG/PLA fibrous scaffolds presented better differentiation potential with higher messenger ribonucleic acid expression of the earliest osteogenic marker Cbfa-1 and mid-stage osteogenic marker Col I. The significantly higher alkaline phosphatase activity of the PEG/PLA fibrous scaffolds indicated that these can enhance the differentiation of MSCs into osteoblast-like cells. Furthermore, the higher messenger ribonucleic acid level of the late osteogenic differentiation markers OCN (osteocalcin and OPN (osteopontin, accompanied by the positive Alizarin red S staining, showed better maturation of osteogenic induction on the PEG/PLA fibrous scaffolds at the

  2. Design and development of mesoporous glass-based biomaterials for bone tissue engineering and drug release systems

    OpenAIRE

    Philippart, Anahí

    2016-01-01

    In order to overcome clinical challenges for bone tissue regeneration, current tissue engineering research focuses on developing highly performant biomaterials in terms of multifunctionality, i.e. materials that are capable of stimulating bone regeneration and exhibit drug delivery capabilities as well as sufficient mechanical stability. In the framework of this research topic, the work here presented focuses on the development of multifunctional mesoporous bioactive glasses (mBGs) and on the...

  3. Linezolid concentrations in infected soft tissue and bone following repetitive doses in diabetic patients with bacterial foot infections1

    OpenAIRE

    Traunmüller, Friederike; Schintler, Michael V.; Spendel, Stephan; Popovic, Martin; Mauric, Oliver; Scharnagl, Erwin; Joukhadar, Christian

    2010-01-01

    Abstract The present study aimed at assessing unbound extracellular concentrations of linezolid in inflamed soft tissue and bone of diabetic patients suffering from severe bacterial foot infections. Linezolid was administered intravenously twice daily at a dosage of 600mg. At steady-state conditions, the microdialysis technique was utilised to sample serially interstitial space fluid from inflamed subcutaneous adipose tissue and metatarsal bone from 0?8h post dose in three represen...

  4. The role of MRI in image-guided needle biopsy of focal bone and soft tissue neoplasms.

    Science.gov (United States)

    Khoo, M M Y; Saifuddin, A

    2013-07-01

    Magnetic resonance imaging (MRI) plays a critical role in the management pathway of both soft tissue and bone neoplasms, from diagnosis through to post-treatment follow-up. There are a wide range of surgical, oncological, and combined treatment regimes but these rely on accurate histopathological diagnosis. This article reviews the role of MRI in the planning of image-guided needle biopsy for suspected soft tissue and bone tumors.

  5. Autologously generated tissue-engineered bone flaps for reconstruction of large mandibular defects in an ovine model.

    Science.gov (United States)

    Tatara, Alexander M; Kretlow, James D; Spicer, Patrick P; Lu, Steven; Lam, Johnny; Liu, Wei; Cao, Yilin; Liu, Guangpeng; Jackson, John D; Yoo, James J; Atala, Anthony; van den Beucken, Jeroen J J P; Jansen, John A; Kasper, F Kurtis; Ho, Tang; Demian, Nagi; Miller, Michael John; Wong, Mark E; Mikos, Antonios G

    2015-05-01

    The reconstruction of large craniofacial defects remains a significant clinical challenge. The complex geometry of facial bone and the lack of suitable donor tissue often hinders successful repair. One strategy to address both of these difficulties is the development of an in vivo bioreactor, where a tissue flap of suitable geometry can be orthotopically grown within the same patient requiring reconstruction. Our group has previously designed such an approach using tissue chambers filled with morcellized bone autograft as a scaffold to autologously generate tissue with a predefined geometry. However, this approach still required donor tissue for filling the tissue chamber. With the recent advances in biodegradable synthetic bone graft materials, it may be possible to minimize this donor tissue by replacing it with synthetic ceramic particles. In addition, these flaps have not previously been transferred to a mandibular defect. In this study, we demonstrate the feasibility of transferring an autologously generated tissue-engineered vascularized bone flap to a mandibular defect in an ovine model, using either morcellized autograft or synthetic bone graft as scaffold material.

  6. Pilot Study: Unique Response of Bone Tissue During an Investigation of Radio-Adaptive Effects in Mice

    Science.gov (United States)

    Sibonga, J. D.; Iwaniec, U.; Wu, H.

    2011-01-01

    PURPOSE: We obtained bone tissue to evaluate the collateral effects of experiments designed to investigate molecular mechanisms of radio-adaptation in a mouse model. Radio-adaptation describes a process by which the prior exposure to low dose radiation can protect against the toxic effect of a subsequent high dose exposure. In the radio-adaptation experiments, C57Bl/6 mice were exposed to either a Sham or a priming Low Dose (5 cGy) of Cs-137 gamma rays before being exposed to either a Sham or High Dose (6 Gy) 24 hours later. ANALYSIS: Bone tissue were obtained from two experiments where mice were sacrificed at 3 days (n=3/group, 12 total) and at 14 days (n=6/group, 24 total) following high dose exposure. Tissues were analyzed to 1) evaluate a radio-adaptive response in bone tissue and 2) describe cellular and microstructural effects for two skeletal sites with different rates of bone turnover. One tibia and one lumbar vertebrae (LV2), collected at the 3-day time-point, were analyzed by bone histomorphometry and micro-CT to evaluate the cellular response and any evidence of microarchitectural impact. Likewise, tibia and LV2, collected at the 14-day time-point, were analyzed by micro-CT alone to evaluate resulting changes to bone structure and microarchitecture. The data were analyzed by 2-way ANOVA to evaluate the effects of the priming low dose radiation, of the high dose radiation, and of any interaction between the priming low and high doses of radiation. Bone histomorphometry was performed in the cancellous bone (aka trabecular bone) compartments of the proximal tibial metaphysis and of LV2. RESULTS: Cellular Response @ 3 Days The priming Low Dose radiation decreased osteoblast-covered bone perimeter in the proximal tibia and the total cell density in the bone marrow in the LV2. High Dose radiation, regardless of prior exposure to priming dose, dramatically reduced total cell density in bone marrow of both the long bone and vertebra. However, in the proximal

  7. Use of magnetic particles to apply mechanical forces for bone tissue engineering purposes

    Energy Technology Data Exchange (ETDEWEB)

    Cartmell, S H; Keramane, A; Kirkham, G R; Verschueren, S B; Magnay, J L; El Haj, A J; Dobson, J [Institute of Science and Technology in Medicine, University of Keele, Thornburrow Drive, Hartshill, Stoke-on-Trent, Staffordshire ST4 7QB (United Kingdom)

    2005-01-01

    It is possible to influence osteoblast activity by the application of mechanical forces. There is potential in using these forces for tissue engineering applications in that cell matrix production may be upregulated, resulting in a functional tissue engineered construct created in a shorter culture time. We have been developing a novel technique for applying mechanical forces directly to the cell with the use of magnetic particles. Particles attached to the cell membrane can be manipulated using an external magnetic field thus applying forces in the piconewton range. We have previously demonstrated that primary human osteoblasts respond to this type of stimulus by upregulating bone related gene expression and producing mineralized matrix at early time points. In this paper we discuss the optimization of this technique by presenting data on the effects of this type of force on osteoblast proliferation, phagocytosis and also the potential use of this technique in developing 3D tissue engineered constructs.

  8. Preparation of poly(γ-glutamic acid)/hydroxyapatite monolith via biomineralization for bone tissue engineering.

    Science.gov (United States)

    Park, Sung-Bin; Hasegawa, Urara; van der Vlies, André J; Sung, Moon-Hee; Uyama, Hiroshi

    2014-01-01

    A hybrid monolith of poly(γ-glutamic acid) and hydroxyapatite (PGA/HAp monolith) was prepared via biomineralization and used as a macroporous cell scaffold in bone tissue engineering. The PGA monolith having a bimodal pore size distribution was used as a substrate to induce biomineralization. The PGA/HAp monolith was obtained by immersing the PGA monolith in simulated body fluid. Pretreatment with CaCl2 enhanced the apatite-forming ability of the PGA monolith. Murine osteoblastic MC3T3-E1 cells efficiently attached and proliferated on the PGA/HAp monolith. MTT assay showed that both the PGA and PGA/HAp monolith did not have apparent cytotoxicity. Moreover, the PGA and PGA/HAp monoliths adsorbed bone morphogenetic protein-2 (BMP-2) by electrostatic interaction which was slowly released in the medium during cell culture. The PGA/HAp monolith enhanced BMP-2 induced alkaline phosphatase activity compared to the PGA monolith and a polystyrene culture plate. Thus, these PGA/HAp monoliths may have potential in bone tissue engineering.

  9. Inter-dependent tissue growth and Turing patterning in a model for long bone development

    Science.gov (United States)

    Tanaka, Simon; Iber, Dagmar

    2013-10-01

    The development of long bones requires a sophisticated spatial organization of cellular signalling, proliferation, and differentiation programs. How such spatial organization emerges on the growing long bone domain is still unresolved. Based on the reported biochemical interactions we developed a regulatory model for the core signalling factors IHH, PTCH1, and PTHrP and included two cell types, proliferating/resting chondrocytes and (pre-)hypertrophic chondrocytes. We show that the reported IHH-PTCH1 interaction gives rise to a Schnakenberg-type Turing kinetics, and that inclusion of PTHrP is important to achieve robust patterning when coupling patterning and tissue dynamics. The model reproduces relevant spatiotemporal gene expression patterns, as well as a number of relevant mutant phenotypes. In summary, we propose that a ligand-receptor based Turing mechanism may control the emergence of patterns during long bone development, with PTHrP as an important mediator to confer patterning robustness when the sensitive Turing system is coupled to the dynamics of a growing and differentiating tissue. We have previously shown that ligand-receptor based Turing mechanisms can also result from BMP-receptor, SHH-receptor, and GDNF-receptor interactions, and that these reproduce the wildtype and mutant patterns during digit formation in limbs and branching morphogenesis in lung and kidneys. Receptor-ligand interactions may thus constitute a general mechanism to generate Turing patterns in nature.

  10. Preparation and characterization of chitosan-natural nano hydroxyapatite-fucoidan nanocomposites for bone tissue engineering.

    Science.gov (United States)

    Lowe, Baboucarr; Venkatesan, Jayachandran; Anil, Sukumaran; Shim, Min Suk; Kim, Se-Kwon

    2016-12-01

    Solid three dimensional (3D) composite scaffolds for bone tissue engineering were prepared using the freeze-drying method. The scaffolds were composed of chitosan, natural nano-hydroxyapatite (nHA) and fucoidan in the following combinations: chitosan, chitosan-fucoidan, chitosan-nHA, and chitosan-nHA-fucoidan. Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and optical microscopy (OM) were used to determine the physiochemical constituents and the morphology of the scaffolds. The addition of nHA into the chitosan-fucoidan composite scaffold reduced the water uptake and water retention. FT-IR analysis confirmed the presence of a phosphate group in the chitosan-nHA-fucoidan scaffold. This group is present because of the presence of nHA (isolated via alkaline hydrolysis from salmon fish bones). Microscopic results indicated that the dispersion of nHA and fucoidan in the chitosan matrix was uniform with a pore size of 10-400μm. The composite demonstrated a suitable micro architecture for cell growth and nutrient supplementation. This compatibility was further elucidated in vitro using periosteum-derived mesenchymal stem cells (PMSCs). The cells demonstrated high biocompatibility and excellent mineralization for the chitosan-nHA-fucoidan scaffold. We believe that a chitosan-nHA-fucoidan composite is a promising biomaterial for the scaffold that can be used for bone tissue regeneration.

  11. Hydrothermal fabrication of hydroxyapatite/chitosan/carbon porous scaffolds for bone tissue engineering.

    Science.gov (United States)

    Long, Teng; Liu, Yu-Tai; Tang, Sha; Sun, Jin-Liang; Guo, Ya-Ping; Zhu, Zhen-An

    2014-11-01

    Porous carbon fiber felts (PCFFs) have great applications in orthopedic surgery because of the strong mechanical strength, low density, high stability, and porous structure, but they are biologically inert. To improve their biological properties, we developed, for the first time, the hydroxyapatite (HA)/chitosan/carbon porous scaffolds (HCCPs). HA/chitosan nanohybrid coatings have been fabricated on PCFFs according to the following stages: (i) deposition of chitosan/calcium phosphate precursors on PCFFs; and (ii) hydrothermal transformation of the calcium phosphate precursors in chitosan matrix into HA nanocrystals. The scanning electron microscopy images indicate that PCFFs are uniformly covered with elongated HA nanoplates and chitosan, and the macropores in PCFFs still remain. Interestingly, the calcium-deficient HA crystals exist as plate-like shapes with thickness of 10-18 nm, width of 30-40 nm, and length of 80-120 nm, which are similar to the biological apatite. The HA in HCCPs is similar to the mineral of natural bone in chemical composition, crystallinity, and morphology. As compared with PCFFs, HCCPs exhibit higher in vitro bioactivity and biocompatibility because of the presence of the HA/chitosan nanohybrid coatings. HCCPs not only promote the formation of bone-like apatite in simulated body fluid, but also improve the adhesion, spreading, and proliferation of human bone marrow stromal cells. Hence, HCCPs have great potentials as scaffold materials for bone tissue engineering and implantation.

  12. Preparation and mechanical property of a novel 3D porous magnesium scaffold for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xue [Institute of Materials Physics and Chemistry, College of Sciences, Northeastern University, Shenyang 110819 (China); Key Laboratory for Anisotropy and Texture Engineering of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Li, Xiao-Wu, E-mail: xwli@mail.neu.edu.cn [Institute of Materials Physics and Chemistry, College of Sciences, Northeastern University, Shenyang 110819 (China); Key Laboratory for Anisotropy and Texture Engineering of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Li, Ji-Guang; Sun, Xu-Dong [Key Laboratory for Anisotropy and Texture Engineering of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China)

    2014-09-01

    Porous magnesium has been recently recognized as a biodegradable metal for bone substitute applications. A novel porous Mg scaffold with three-dimensional (3D) interconnected pores and with a porosity of 33–54% was produced by the fiber deposition hot pressing (FDHP) technology. The microstructure and morphologies of the porous Mg scaffold were characterized by scanning electron microscopy (SEM), and the effects of porosities on the microstructure and mechanical properties of the porous Mg were investigated. Experimental results indicate that the measured Young's modulus and compressive strength of the Mg scaffold are ranged in 0.10–0.37 GPa, and 11.1–30.3 MPa, respectively, which are fairly comparable to those of cancellous bone. Such a porous Mg scaffold having a 3D interconnected network structure has the potential to be used in bone tissue engineering. - Highlights: • A novel porous Mg was produced by a fiber deposition hot pressing technology. • The porous Mg has a 3D interconnected network structure with a porosity of 33-54%. • Mechanical properties of the porous Mg are comparable to those of cancellous bone.

  13. Multilayer Nanoscale Encapsulation of Biofunctional Peptides to Enhance Bone Tissue Regeneration In Vivo.

    Science.gov (United States)

    Gentile, Piergiorgio; Ferreira, Ana Marina; Callaghan, Jill T; Miller, Cheryl A; Atkinson, Joss; Freeman, Christine; Hatton, Paul V

    2017-02-07

    Bone tissue healing is a dynamic process that is initiated by the recruitment of osteoprogenitor cells followed by their migration, proliferation, differentiation, and development of a mineralizing extracellular matrix. The work aims to manufacture a functionalized porous membrane that stimulates early events in bone healing for initiating a regenerative cascade. Layer-by-layer (LbL) assembly is proposed to modify the surface of osteoconductive electrospun meshes, based on poly(lactic-co-glycolic acid) and nanohydroxyapatite, by using poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) as polyelectrolytes. Molecular cues are incorporated by grafting peptide fragments into the discrete nanolayers. KRSR (lysine-arginine-serine-arginine) sequence is grafted to enhance cell adhesion and proliferation, NSPVNSKIPKACCVPTELSAI to guide bone marrow mesenchymal stem cells differentiation in osteoblasts, and FHRRIKA (phenylalanine-histidine-arginine-arginine-isoleucine-lysine-alanine) to improve mineralization matrix formation. Scanning electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy demonstrate the successful surface functionalization. Furthermore, the peptide incorporation enhances cellular processes, with good viability and significant increase of alkaline phosphatase activity, osteopontin, and osteocalcin. The functionalized membrane induces a favorable in vivo response after implantation for four weeks in nonhealing rat calvarial defect model. It is concluded that the multilayer nanoencapsulation of biofunctional peptides using LbL approach has significant potential as innovative manufacturing technique to improve bone regeneration in orthopedic and craniofacial medical devices.

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

    Science.gov (United States)

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

    2015-09-01

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

  15. Chitosan-poly(lactide-co-glycolide) microsphere-based scaffolds for bone tissue engineering: in vitro degradation and in vivo bone regeneration studies.

    Science.gov (United States)

    Jiang, Tao; Nukavarapu, Syam P; Deng, Meng; Jabbarzadeh, Ehsan; Kofron, Michelle D; Doty, Stephen B; Abdel-Fattah, Wafa I; Laurencin, Cato T

    2010-09-01

    Natural polymer chitosan and synthetic polymer poly(lactide-co-glycolide) (PLAGA) have been investigated for a variety of tissue engineering applications. We have previously reported the fabrication and in vitro evaluation of a novel chitosan/PLAGA sintered microsphere scaffold for load-bearing bone tissue engineering applications. In this study, the in vitro degradation characteristics of the chitosan/PLAGA scaffold and the in vivo bone formation capacity of the chitosan/PLAGA-based scaffolds in a rabbit ulnar critical-sized-defect model were investigated. The chitosan/PLAGA scaffold showed slower degradation than the PLAGA scaffold in vitro. Although chitosan/PLAGA scaffold showed a gradual decrease in compressive properties during the 12-week degradation period, the compressive strength and compressive modulus remained in the range of human trabecular bone. Chitosan/PLAGA-based scaffolds were able to guide bone formation in a rabbit ulnar critical-sized-defect model. Microcomputed tomography analysis demonstrated that successful bridging of the critical-sized defect on the sides both adjacent to and away from the radius occurred using chitosan/PLAGA-based scaffolds. Immobilization of heparin and recombinant human bone morphogenetic protein-2 on the chitosan/PLAGA scaffold surface promoted early bone formation as evidenced by complete bridging of the defect along the radius and significantly enhanced mechanical properties when compared to the chitosan/PLAGA scaffold. Furthermore, histological analysis suggested that chitosan/PLAGA-based scaffolds supported normal bone formation via intramembranous formation.

  16. [Capabilities of digital microfocal x-ray study in the evaluation of reparative regeneration of bone tissue in an experiment].

    Science.gov (United States)

    Vasil'ev, A Iu; Bulanova, I M; Mal'ginov, N N; Kiseleva, E V; Cherniaev, S E; Nikulina, O M; Tarasenko, I V; Volozhin, A I

    2008-01-01

    Digital microfocal x-ray study was experimentally studied in animals to examine the time course of changes in their bone regeneration. Sixteen Chinchila rabbits whose bone defect in the angle of the mandibular ramus had been closed with the osteoplastic material Gapcol with the applied allogeneic, autologous stem cells isolated from rabbit adipose tissue and human plasma enriched with thrombocytic growth factors were examined. The capabilities of digital microfocal x-ray study versus x-ray computed tomography were compared in the evaluation of reparative regeneration of bone tissue. The results of radiation studies were verified with the data of scanning electron microscopy.

  17. Synthesis and Characterization of Nano Hydroxyapatite with Poly Vinyl Pyrrolidone Nano Composite for Bone Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    A. Ragu

    2014-07-01

    Full Text Available Hydroxyapatite (Ca10 (PO46(OH2 , the main mineral component of bone and teeth, is native to the human body. Hydroxyapatite (HAp is a desirable implant material due to its biocompatibility and osteoconductivity properties. In this study, nano hydroxyapatite (nHAp with poly vinyl pyrrolidone (PVP was synthesized at room temperature condition. The synthetic nano hydroxyapatite (nHAp prepared by wet chemical precipitation method was investigated. Hydroxyapatite is biocompatible with the human organism and is capable of integrating biologically into bone tissue. The synthesized sample were characterized by Fourier transformed infrared spectroscopy (FTIR, X-ray diffraction (XRD, Transmission electron microscope (TEM, Energy dispersive analysis of x-rays techniques (EDAX and Micro hardness test.

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  19. Unusual intraosseous fossilized soft tissues from the Middle Triassic Nothosaurus bone

    Science.gov (United States)

    Surmik, Dawid; Rothschild, Bruce M.; Pawlicki, Roman

    2017-04-01

    Fossilized soft tissues, occasionally found together with skeletal remains, provide insights to the physiology and functional morphology of extinct organisms. Herein, we present unusual fossilized structures from the cortical region of bone identified in isolated skeletal remains of Middle Triassic nothosaurs from Upper Silesia, Poland. The ribbed or annuli-shaped structures have been found in a sample of partially demineralized coracoid and are interpreted as either giant red blood cells or as blood vessel walls. The most probable function is reinforcing the blood vessels from changes of nitrogen pressure in air-breathing diving reptiles. These structures seem to have been built of extensible muscle layers which prevent the vessel damage during rapid ascent. Such suspected function presented here is parsimonious with results of previous studies, which indicate rarity of the pathological modification of bones associated with decompression syndrome in Middle Triassic nothosaurs.

  20. Priming the Surface of Orthopedic Implants for Osteoblast Attachment in Bone Tissue Engineering.

    Science.gov (United States)

    Chan, Kiat Hwa; Zhuo, Shuangmu; Ni, Ming

    2015-01-01

    The development of better orthopedic implants is incessant. While current implants can function reliably in the human body for a long period of time, there are still a significant number of cases for which the implants can fail prematurely due to poor osseointegration of the implant with native bone. Increasingly, it is recognized that it is extremely important to facilitate the attachment of osteoblasts on the implant so that a proper foundation of extracellular matrix (ECM) can be laid down for the growth of new bone tissue. In order to facilitate the osseointegration of the implant, both the physical nanotopography and chemical functionalization of the implant surface have to be optimized. In this short review, however, we explore how simple chemistry procedures can be used to functionalize the surfaces of three major classes of orthopedic implants, i.e. ceramics, metals, and polymers, so that the attachment of osteoblasts on implants can be facilitated in order to promote implant osseointegration.

  1. Precision extruding deposition (PED) fabrication of polycaprolactone (PCL) scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shor, Lauren; Gueceri, Selcuk; Chang, Robert; Sun Wei [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA (United States); Gordon, Jennifer; Kang Qian; Hartsock, Langdon; An Yuehuei [Department of Orthopedic Surgery, Medical University of South Carolina, Charleston, SC (United States)], E-mail: st963bya@drexel.edu, E-mail: guceri@drexel.edu, E-mail: rcc34@drexel.edu, E-mail: sunwei@drexel.edu, E-mail: kangqk@musc.edu, E-mail: hartsock@musc.edu, E-mail: any@musc.edu

    2009-03-01

    Bone tissue engineering is an emerging field providing viable substitutes for bone regeneration. Recent advances have allowed scientists and engineers to develop scaffolds for guided bone growth. However, success requires scaffolds to have specific macroscopic geometries and internal architectures conducive to biological and biophysical functions. Freeform fabrication provides an effective process tool to manufacture three-dimensional porous scaffolds with complex shapes and designed properties. A novel precision extruding deposition (PED) technique was developed to fabricate polycaprolactone (PCL) scaffolds. It was possible to manufacture scaffolds with a controlled pore size of 350 {mu}m with designed structural orientations using this method. The scaffold morphology, internal micro-architecture and mechanical properties were evaluated using scanning electron microscopy (SEM), micro-computed tomography (micro-CT) and mechanical testing, respectively. An in vitro cell-scaffold interaction study was carried out using primary fetal bovine osteoblasts. Specifically, the cell proliferation and differentiation was evaluated by Alamar Blue assay for cell metabolic activity, alkaline phosphatase activity and osteoblast production of calcium. An in vivo study was performed on nude mice to determine the capability of osteoblast-seeded PCL to induce osteogenesis. Each scaffold was implanted subcutaneously in nude mice and, following sacrifice, was explanted at one of a series of time intervals. The explants were then evaluated histologically for possible areas of osseointegration. Microscopy and radiological examination showed multiple areas of osseous ingrowth suggesting that the osteoblast-seeded PCL scaffolds evoke osteogenesis in vivo. These studies demonstrated the viability of the PED process to fabricate PCL scaffolds having the necessary mechanical properties, structural integrity, and controlled pore size and interconnectivity desired for bone tissue engineering.

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

    Science.gov (United States)

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

    2010-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-01

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

  4. Ultrasonic tissue characterization for monitoring nanostructured TiO{sub 2}-induced bone growth

    Energy Technology Data Exchange (ETDEWEB)

    Rus, G [Department of Structural Mechanics, University of Granada, Politecnico de Fuentenueva, 18071 Granada (Spain); Garcia-MartInez, J [Department of Inorganic Chemistry, University of Alicante, E-03690 Alicante (Spain)

    2007-07-21

    The use of bioactive nanostructured TiO{sub 2} has recently been proposed for improving orthopaedic implant adhesion due to its improved biocompatibility with bone, since it induces: (i) osteoblast function, (ii) apatite nucleation and (iii) protein adsorption. The present work focuses on a non-ionizing radiation emitting technique for quantifying in real time the improvement in terms of mechanical properties of the surrounding bone due to the presence of the nanostructured TiO{sub 2} prepared by controlled precipitation and acid ageing. The mechanical strength is the ultimate goal of a bone implant and is directly related to the elastic moduli. Ultrasonics are high frequency mechanical waves and are therefore suited for characterizing elastic moduli. As opposed to echographic techniques, which are not correlated to elastic properties and are not able to penetrate bone, a low frequency ultrasonic transmission test is proposed, in which a P-wave is transmitted through the specimen and recorded. The problem is posed as an inverse problem, in which the unknown is a set of parameters that describe the mechanical constants of the sequence of layers. A finite element numerical model that depends on these parameters is used to predict the transformation of the waveform and compare to the measurement. The parameters that best describe the real tissue are obtained by minimizing the discrepancy between the real and numerically predicted waveforms. A sensitivity study to the uncertainties of the model is performed for establishing the feasibility of using this technique to investigate the macroscopic effect on bone growth of nanostructured TiO{sub 2} and its beneficial effect on implant adhesion.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-01

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

  6. Application of new optical coherence elastography to monitor the mineralization processing in bone tissue engineering constructs

    Science.gov (United States)

    Guan, Guangying; Song, Shaozhen; Huang, Zhihong; Yang, Ying

    2015-03-01

    Generation of functional tissue in vitro through tissue engineering technique is a promising direction to repair and replace malfunctioned organ and tissue in the modern medicine for various diseases which could not been treated well by conventional therapy. Similar to the embryo development, the generation of tissue in vitro is a highly dynamic processing. Obtaining the feedback of the processing real time is highly demanded. In this study, a new methodology has been explored aiming to monitor the morphological and mechanical property alteration of bone tissue engineering constructs simultaneously. Optical coherence elastography (OCE) equipped with a LDS V201 permanent magnet shaker and a modulated acoustic radiation force (ARF) to provide a vibration signal, has been used for the real time and non-destructive monitoring. A phantom construct system has been used to optimize the measurement conditions in which agar hydrogel with concentration from 0, 0.75 to 2% with/without hydroxyappatite particles have been injected to 3D porous poly (lactic acid) scaffolds to simulate the collagenous extracellular matrix (ECM) and mineralized ECM. The structural and elastography images of the constructs have clearly demonstrated the linear relation with the increased mechanical property versus the increase of agar concentration within the pores of the scaffolds. The MG63 bone cells seeded in the scaffolds and cultured for 4 weeks have been monitored by the established protocol exhibiting the increased mechanical strength in the pore wall where the ECM or mineralized ECM was assumed to be formed in comparison to empty pores. This study confirms that OCE-ARF could become a valuable tool in regenerative medicine to assess the biological events during in vitro culture and conditioning.

  7. Signaling Interplay between Bone Marrow Adipose Tissue and Multiple Myeloma cells.

    Science.gov (United States)

    Falank, Carolyne; Fairfield, Heather; Reagan, Michaela R

    2016-01-01

    In the year 2000, Hanahan and Weinberg (1) defined the six Hallmarks of Cancer as: self-sufficiency in growth signals, evasion of apoptosis, insensitivity to antigrowth mechanisms, tissue invasion and metastasis, limitless replicative potential, and sustained angiogenesis. Eleven years later, two new Hallmarks were added to the list (avoiding immune destruction and reprograming energy metabolism) and two new tumor characteristics (tumor-promoting inflammation and genome instability and mutation) (2). In multiple myeloma (MM), a destructive cancer of the plasma cell that grows predominantly in the bone marrow (BM), it is clear that all these hallmarks and characteristics are in play, contributing to tumor initiation, drug resistance, disease progression, and relapse. Bone marrow adipose tissue (BMAT) is a newly recognized contributor to MM oncogenesis and disease progression, potentially affecting MM cell metabolism, immune action, inflammation, and influences on angiogenesis. In this review, we discuss the confirmed and hypothetical contributions of BMAT to MM development and disease progression. BMAT has been understudied due to technical challenges and a previous lack of appreciation for the endocrine function of this tissue. In this review, we define the dynamic, responsive, metabolically active BM adipocyte. We then describe how BMAT influences MM in terms of: lipids/metabolism, hypoxia/angiogenesis, paracrine or endocrine signaling, and bone disease. We then discuss the connection between BMAT and systemic inflammation and potential treatments to inhibit the feedback loops between BM adipocytes and MM cells that support MM progression. We aim for researchers to use this review to guide and help prioritize their experiments to develop better treatments or a cure for cancers, such as MM, that associate with and may depend on BMAT.

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

    Directory of Open Access Journals (Sweden)

    Everest Akaraonye

    2016-01-01

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

  9. Evaluation of soft tissue coverage over porous polymethylmethacrylate space maintainers within nonhealing alveolar bone defects.

    Science.gov (United States)

    Kretlow, James D; Shi, Meng; Young, Simon; Spicer, Patrick P; Demian, Nagi; Jansen, John A; Wong, Mark E; Kasper, F Kurtis; Mikos, Antonios G

    2010-12-01

    Current treatment of traumatic craniofacial injuries often involves early free tissue transfer, even if the recipient site is contaminated or lacks soft tissue coverage. There are no current tissue engineering strategies to definitively regenerate tissues in such an environment at an early time point. For a tissue engineering approach to be employed in the treatment of such injuries, a two-stage approach could potentially be used. The present study describes methods for fabrication, characterization, and processing of porous polymethylmethacrylate (PMMA) space maintainers for temporary retention of space in bony craniofacial defects. Carboxymethylcellulose hydrogels were used as a porogen. Implants with controlled porosity and pore interconnectivity were fabricated by varying the ratio of hydrogel:polymer and the amount of carboxymethylcellulose within the hydrogel. The in vivo tissue response to the implants was observed by implanting solid, low-porosity, and high-porosity implants (n = 6) within a nonhealing rabbit mandibular defect that included an oral mucosal defect to allow open communication between the oral cavity and the mandibular defect. Oral mucosal wound healing was observed after 12 weeks and was complete in 3/6 defects filled with solid PMMA implants and 5/6 defects filled with either a low- or high-porosity PMMA implant. The tissue response around and within the pores of the two formulations of porous implants tested in vivo was characterized, with the low-porosity implants surrounded by a minimal but well-formed fibrous capsule in contrast to the high-porosity implants, which were surrounded and invaded by almost exclusively inflammatory tissue. On the basis of these results, PMMA implants with limited porosity hold promise for temporary implantation and space maintenance within clean/contaminated bone defects.

  10. Higher number of pentosidine cross-links induced by ribose does not alter tissue stiffness of cancellous bone

    Energy Technology Data Exchange (ETDEWEB)

    Willems, Nop M.B.K., E-mail: n.willems@acta.nl [Dept. of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Langenbach, Geerling E.J. [Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Stoop, Reinout [Dept. of Metabolic Health Research, TNO, P.O. Box 2215, 2301 CE Leiden (Netherlands); Toonder, Jaap M.J. den [Dept. of Mechanical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Mulder, Lars [Dept. of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Zentner, Andrej [Dept. of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Everts, Vincent [Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands)

    2014-09-01

    The role of mature collagen cross-links, pentosidine (Pen) cross-links in particular, in the micromechanical properties of cancellous bone is unknown. The aim of this study was to examine nonenzymatic glycation effects on tissue stiffness of demineralized and non-demineralized cancellous bone. A total of 60 bone samples were derived from mandibular condyles of six pigs, and assigned to either control or experimental groups. Experimental handling included incubation in phosphate buffered saline alone or with 0.2 M ribose at 37 °C for 15 days and, in some of the samples, subsequent complete demineralization of the sample surface using 8% EDTA. Before and after experimental handling, bone microarchitecture and tissue mineral density were examined by means of microcomputed tomography. After experimental handling, the collagen content and the number of Pen, hydroxylysylpyridinoline (HP), and lysylpyridinoline (LP) cross-links were estimated using HPLC, and tissue stiffness was assessed by means of nanoindentation. Ribose treatment caused an up to 300-fold increase in the number of Pen cross-links compared to nonribose-incubated controls, but did not affect the number of HP and LP cross-links. This increase in the number of Pen cross-links had no influence on tissue stiffness of both demineralized and nondemineralized bone samples. These findings suggest that Pen cross-links do not play a significant role in bone tissue stiffness. - Highlights: • The assessment of effects of glycation in bone using HPLC, microCT, and nanoindentation • Ribose incubation: 300‐fold increase in the number of pentosidine cross-links • 300‐fold increase in the number of pentosidine cross-links: no changes in bone tissue stiffness.

  11. Determining the modulus of intact bovine vertebral cancellous bone tissue: Development and validation of a protocol

    Science.gov (United States)

    Engbretson, Andrew Craig

    Cancellous, or spongy, bone accounts for nearly 80% of the human skeleton's internal surface area, despite comprising only 20% of its mass. It is made up of a network of struts and plates that provide lightweight internal support to mammalian bones. In addition, it often serves as the main interface between the skeletal system and implanted devices such as artificial hips, knees, and fracture fixation devices. However, hip arthroplasties can succumb to loosening of the implant due to bone resorption, which is thought to be caused by a mismatch in both apparent and real stiffness between the device and the surrounding bone. Many studies have attempted to determine the Young's modulus of cancellous bone tissue, but the results are far from being in agreement. Reported values range from less than 1 to nearly 20 GPa. In addition, the small size of trabeculae has made dissection and testing a challenge. In this thesis, whole individual trabeculae from a bovine lumbar spine were tested in three-point bending to determine their Young's modulus using custom-made equipment to fit a miniature single-axis testing device. The device itself was validated by testing materials with moduli ranging from 1 to 200 GPa. The structure of the cancellous bone and the morphology of the individual struts were determined using micro x-ray computed tomography (muXCT). Individual struts were manually isolated from slices made using a low-speed saw under constant lubrication and measured under a stereomicroscope. Samples exhibiting no machined surfaces (and thus deemed to be whole, or "uncut" were compared to struts that had been cut by the saw during sectioning. Validation showed that the system was capable of determining the modulus of materials that were approximately five times stiffer than the expected cancellous modulus (copper, at 115 GPa) to within 10% of published values. This gave confidence in the results for bone. The modulus of the "uncut" specimens was found to be 15.28 2.26 GPa

  12. Tissue-engineered bone repairs sheep alveolar bone defects%组织工程化骨修复羊牙槽骨缺损***

    Institute of Scientific and Technical Information of China (English)

    张琴; 杨川博; 何惠宇; 崔杰; 杨楠; 马文渊

    2013-01-01

    BACKGROUND:Fol owing physicochemical treatment and high-temperature calcinations, heterogeneous biological bone becomes a ceramic-like heterologous bone forming a similar structure to the human bone that is a natural network pore structure, which is conducive to seed cel adhesion and proliferation. OBJECTIVE:To observe the feasibility of constructing tissue-engineered bone through combination of sintered bone and bone marrow mesenchymal stem cel s to repair alveolar defects. METHODS:Sheep bone marrow mesenchymal stem cel s as seed cel s were combined with the high temperature sintered bone as scaffold materials to construct tissue-engineered bone. Under general anesthesia, sheep bilateral mandibular first premolars were removed in batches, the alveolar ridge space between the distal root and mesial root of the second premolar to form a bone defect area of 5 mm×5 mm×5 mm. Twelve experimental sheep were equal y randomized into tissue-engineered bone group and sintered bone group, which were implanted with tissue-engineered bone and sintered bone, respectively, at the left surgical area of the mandible. The right surgical area was considered as blank control group. RESULTS AND CONCLUSION:After high-temperature calcinations, the sintered bone was chalk in color, exhibiting a porous structure as the natural cancel ous bone. The porosity was (66.10±1.32)%, and the pore size was between 137.44μm and 538.72μm. After 24 hours of bone marrow mesenchymal stem cel s inoculated to the sintered bone, a large number of cel s are visible adherent to the scaffold;up to day 7, extracel ular matrix was secreted and there was no clear boundary between the cel s and the matrix. X-ray films showed that the tissue-engineered bone and pure sintered bone implants were embedded in the surgical area, and there was a low-density shadow at the edge of the sintered bone. Hematoxylin-eosin staining showed bone trabecular formation at the experimental side, but no obvious bone formation at

  13. In vivo bone biocompatibility and degradation of porous fumarate-based polymer/alumoxane nanocomposites for bone tissue engineering.

    NARCIS (Netherlands)

    Mistry, A.S.; Pham, Q.P.; Schouten, C.; Yeh, T.; Christenson, E.M.; Mikos, A.G.; Jansen, J.A.

    2010-01-01

    The objective of this study was to determine how the incorporation of surface-modified alumoxane nanoparticles into a biodegradable fumarate-based polymer affects in vivo bone biocompatibility (characterized by direct bone contact and bone ingrowth) and in vivo degradability. Porous scaffolds were f

  14. Relative binding affinity of carboxylate-, phosphonate-, and bisphosphonate-functionalized gold nanoparticles targeted to damaged bone tissue

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Ryan D. [Rush University Medical Center, Department of Anatomy and Cell Biology (United States); Cole, Lisa E.; Roeder, Ryan K., E-mail: rroeder@nd.edu [University of Notre Dame, Department of Aerospace and Mechanical Engineering Bioengineering Graduate Program (United States)

    2012-10-15

    Functionalized Au NPs have received considerable recent interest for targeting and labeling cells and tissues. Damaged bone tissue can be targeted by functionalizing Au NPs with molecules exhibiting affinity for calcium. Therefore, the relative binding affinity of Au NPs surface functionalized with either carboxylate (l-glutamic acid), phosphonate (2-aminoethylphosphonic acid), or bisphosphonate (alendronate) was investigated for targeted labeling of damaged bone tissue in vitro. Targeted labeling of damaged bone tissue was qualitatively verified by visual observation and backscattered electron microscopy, and quantitatively measured by the surface density of Au NPs using field-emission scanning electron microscopy. The surface density of functionalized Au NPs was significantly greater within damaged tissue compared to undamaged tissue for each functional group. Bisphosphonate-functionalized Au NPs exhibited a greater surface density labeling damaged tissue compared to glutamic acid- and phosphonic acid-functionalized Au NPs, which was consistent with the results of previous work comparing the binding affinity of the same functionalized Au NPs to synthetic hydroxyapatite crystals. Targeted labeling was enabled not only by the functional groups but also by the colloidal stability in solution. Functionalized Au NPs were stabilized by the presence of the functional groups, and were shown to remain well dispersed in ionic (phosphate buffered saline) and serum (fetal bovine serum) solutions for up to 1 week. Therefore, the results of this study suggest that bisphosphonate-functionalized Au NPs have potential for targeted delivery to damaged bone tissue in vitro and provide motivation for in vivo investigation.

  15. [Maxillary alveolar process bone plasty with the use of directional tissue regeneration and maxillary sinus bottom lifting operation].

    Science.gov (United States)

    Losev, V F

    2009-01-01

    There were shown technique and clinical examples of the use of directional tissue regeneration in cases of bone tissue deficit in distal parts maxilla. Clinical cases were described of maxillary sinus bottom lifting with simultaneous alveolar process widening and single stage implant installation.

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

    Institute of Scientific and Technical Information of China (English)

    陈海霞; 谢志刚

    2014-01-01

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

  17. The enzyme profiles in the connective tissue attaching pin bones to the surrounding tissue is specific in farmed salmon (Salmo salar) and cod (Gadus morhua L.).

    Science.gov (United States)

    Vuong, Tram T; Rønning, Sissel B; Kolset, Svein O; Pedersen, Mona E

    2017-02-01

    Post mortem storage is a necessary process for removal of pin bones without destruction of fillets, thereby avoiding volume and economic loss. However, the enzymes involved in loosening pin bones during storage have not been studied to a great extent. In this study, the activities and localization of MMPs in the connective tissue (CT) of pin bones dissected from fillet of salmon and cod were investigated. Interestingly, the enzyme activity profile in these two species was different during post mortem storage of fish fillets. Adding MMP inhibitor (GM6001) and serine protease inhibitor (Pefabloc) revealed different effects in the two species, suggesting different regulations in salmon and cod. In situ zymography with the same inhibitors verified MMP and serine protease activity in CT close to pin bone at early post mortem (6 h) in salmon. However, MMP inhibition was not evident in cod in this area at that time point. Immunohistochemistry further revealed MMP9 and MMP13 were located more to the outer rim of CT, facing the pin bone and adipose tissue, while MMP7 was more randomly distributed within CT in salmon. In contrast, all these three MMPs were randomly distributed in CT in cod. In summary, our study reveals different MMP enzyme profiles in salmon and cod in the pin bone area, influenced by serine proteases, and suggests that MMPs and serine proteases must be taken in consideration when studying the conditions for early pin bone removal.

  18. Microscale Material Properties of Bone and the Mineralized Tissues of the Intervertebral Disc-Vertebral Body Interface

    Science.gov (United States)

    Paietta, Rachel C.

    The objective of this dissertation is to understand the influences of material structure on the properties, function and failure of biological connective tissues. Biological interfaces are becoming an increasingly studied system within mechanics and tissue engineering as a model for attaching dissimilar materials. The elastic modulus of bone (≈ 20 GPa) and cartilage (≈ 0.1-1 MPa) differ over orders of magnitude, which should intuitively create high stress concentrations and failure at the interface. Yet, these natural interface systems rarely fail in vivo, and the mechanism by which loads are transferred between tissues has not yet been established. Tissue quality is one major contributor to the mechanical behavior of bone and cartilage, and is defined by properties such as collagen orientation, mineral volume fraction, porosity and tissue geometry. These properties have yet to be established at the bone-cartilage interface in the spine, and the lack of quantitative data on material microstructure and behavior limits treatments and tissue engineering construct design. In this dissertation, second harmonic generation imaging, quantitative backscattered scanning electron imaging and nanoindentation are combined to characterize micrometer scale tissue quality and modulus in both bone and calcified cartilage. These techniques are utilized to: 1) determine the hierarchical micrometer to millimeter scale properties of lamellar bone, 2) quantify changes throughout development and aging at the human intervertebral disc-vertebral body junction, and 3) explore compressive fractures at this interface. This work is the first to provide quantitative data on the mineral volume fraction, collagen orientation and modulus from the same, undecalcified sections of tissue to corroborate tissue structure and mineralization and describe quantitative parameters of the interface. The principal findings from this work indicate that the underlying matrix, or collagen, organization in

  19. Simultaneous implant placement and bone regeneration around dental implants using tissue-engineered bone with fibrin glue, mesenchymal stem cells and platelet-rich plasma.

    Science.gov (United States)

    Ito, Kenji; Yamada, Yoichi; Naiki, Takahito; Ueda, Minoru

    2006-10-01

    This study was undertaken to evaluate the use of tissue-engineered bone as grafting material for alveolar augmentation with simultaneous implant placement. Twelve adult hybrid dogs were used in this study. One month after the extraction of teeth in the mandible region, bone defects on both sides of the mandible were induced using a trephine bar with a diameter of 10 mm. Dog mesenchymal stem cells (dMSCs) were obtained via iliac bone biopsy and cultured for 4 weeks before implantation. After installing the dental implants, the defects were simultaneously implanted with the following graft materials: (i) fibrin, (ii) dMSCs and fibrin (dMSCs/fibrin), (iii) dMSCs, platelet-rich plasma (PRP) and fibrin (dMSCs/PRP/fibrin) and (iv) control (defect only). The implants were assessed by histological and histomorphometric analysis, 2, 4 and 8 weeks after implantation. The implants exhibited varying degrees of bone-implant contact (BIC). The BIC was 17%, 19% and 29% (control), 20%, 22% and 25% (fibrin), 22%, 32% and 42% (dMSCs/fibrin) and 25%, 49% and 53% (dMSCs/PRP/fibrin) after 2, 4 and 8 weeks, respectively. This study suggests that tissue-engineered bone may be of sufficient quality for predictable enhancement of bone regeneration around dental implants when used simultaneous by with implant placement.

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

    Directory of Open Access Journals (Sweden)

    Silvia Panseri

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

  1. Radiation synthesis of gelatin/CM-chitosan/{beta}-tricalcium phosphate composite scaffold for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Ying [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Xu Ling, E-mail: lingxu@pku.edu.cn [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Xiangmei; Zhao Yinghui [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Zhai Maolin [Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2012-05-01

    A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and {beta}-tricalcium phosphate ({beta}-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of {beta}-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of {beta}-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that {beta}-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of {beta}-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/{beta}-TCP composite scaffolds as candidate of bone tissue engineering material. - Highlights: Black-Right-Pointing-Pointer Radiation induced a crosslinked scaffold with interconnected porous structure. Black-Right-Pointing-Pointer Ultrasonic time of 20 min led to homogenerously distribution of {beta}-TCP. Black-Right-Pointing-Pointer Increasing amount of {beta}-TCP would restrict the swelling properties. Black-Right-Pointing-Pointer Proper fraction of {beta}-TCP will promote the mechanical properties of the scaffolds. Black-Right-Pointing-Pointer Hybrid of {beta}-TCP promoted the bone regeneration of the mandibles of beagle dogs.

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

    Science.gov (United States)

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

    2017-02-15

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

  3. Hydroxyapatite-magnetite-MWCNT nanocomposite as a biocompatible multifunctional drug delivery system for bone tissue engineering

    Science.gov (United States)

    Pistone, Alessandro; Iannazzo, Daniela; Panseri, Silvia; Montesi, Monica; Tampieri, Anna; Galvagno, Signorino

    2014-10-01

    New magnetic hydroxyapatite-based nanomaterials as bone-specific systems for controlled drug delivery have been synthesized. The synthesized hydroxyapatite, HA, decorated with magnetite nanoparticles by a deposition method (HA/Fe3O4) and the nanocomposite system obtained using magnetic multi-walled carbon nanotubes (HA/MWCNT/Fe3O4) as a filler for HA have been characterized by chemical and morphological analyses, and their biological behavior was investigated. The systems have also been doped with clodronate in order to combine the effect of bone biomineralization induced by hydroxyapatite-based composites with the decrease of osteoclast formation induced by the drug. An analysis of the preosteoclastic RAW264.7 cell proliferation by MTT assay confirmed the high biocompatibility of the three systems. TRAP staining of RAW 264.7 conditioned with sRAKL to induce osteoclastogenesis, cultured in the presence of the systems doped and undoped with clodronate, showed the inhibitory effect of clodronate after we counted the MNC TRAP+cells but only in the osteoclast formation; in particular, the system HA/Fe3O4-Clo exerted a high inhibitory effect compared to the drug alone. These results demonstrate that the synthesized nanocomposites are a biocompatible magnetic drug delivery system and can represent a useful multimodal platform for applications in bone tissue engineering.

  4. Fabrication of Porous α-TCP/Gellan Gum Scaffold for Bone Tissue Engineering.

    Science.gov (United States)

    Wen, Jian; Kim, Ill Yong; Kikuta, Koichi; Ohtsuki, Chikara

    2016-03-01

    α-tricalcium phosphate (α-TCP, α-Ca3(PO4)2) receives great attention for bone repairing due to its biodegradability and capability of transformation to human bone's main inorganic components, hydroxyapatite (HAp). α-TCP porous scaffold is easily procurable by sintering of the low-temperature polymorph of TCP, β-TCR Still, porous body of α-TCP is too brittle to being handled and shaped, limiting its clinical application as implant materials. To improve mechanical properties of α-TCP porous scaffold, the present study focused on coating of a type of polysaccharides on α-TCP scaffolds. Gellan gum was chosen as the polysaccharide for coating because of its biodegradability as well as the potential acting as substrate for HAp deposition during hydration of α-TCP after exposure to body fluid. After coating of gellan gum on α-TCP scaffolds with porosity of 75 vol%, the compressive strength increased from 0.45 MPa to around 2.00 MPa. Among the coated scaffold, the maximum compressive strength, 3.97 MPa, was obtained on the scaffold with porosity of 63 vol%. Improvement of mechanical properties of α-TCP/gellan gum composites was achieved to show easy handling performance for a bone substitute for tissue repairing. The dissolving rate of the coated scaffolds was also controlled by adjusting the concentration of GG solutions.

  5. 3D Printing of Calcium Phosphate Ceramics for Bone Tissue Engineering and Drug Delivery.

    Science.gov (United States)

    Trombetta, Ryan; Inzana, Jason A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2017-01-01

    Additive manufacturing, also known as 3D printing, has emerged over the past 3 decades as a disruptive technology for rapid prototyping and manufacturing. Vat polymerization, powder bed fusion, material extrusion, and binder jetting are distinct technologies of additive manufacturing, which have been used in a wide variety of fields, including biomedical research and tissue engineering. The ability to print biocompatible, patient-specific geometries with controlled macro- and micro-pores, and to incorporate cells, drugs and proteins has made 3D-printing ideal for orthopaedic applications, such as bone grafting. Herein, we performed a systematic review examining the fabrication of calcium phosphate (CaP) ceramics by 3D printing, their biocompatibility in vitro, and their bone regenerative potential in vivo, as well as their use in localized delivery of bioactive molecules or cells. Understanding the advantages and limitations of the different 3D printing approaches, CaP materials, and bioactive additives through critical evaluation of in vitro and in vivo evidence of efficacy is essential for developing new classes of bone graft substitutes that can perform as well as autografts and allografts or even surpass the performance of these clinical standards.

  6. Enrichment of thermosensitive chitosan hydrogels with glycerol and alkaline phosphatase for bone tissue engineering applications.

    Science.gov (United States)

    Douglas, Timothy E L; Krok-Borkowicz, Małgorzata; Macuda, Aleksandra; Pietryga, Krzysztof; Pamuła, Elżbieta

    2016-01-01

    Thermosensitive injectable chitosan hydrogels can be formed by neutralization of acidic chitosan solutions with sodium betaglycerophosphate (Na-β-GP) coupled with increasing temperature to body temperature. Such hydrogels have been considered for applications in bone regeneration. In this study, chitosan hydrogels were enriched with glycerol and the enzyme alkaline phosphatase (ALP) with a view to improving their suitability as materials for bone tissue engineering. Mineral formation was confirmed by infrared spectroscopy (FTIR) and increases in the mass fraction of the hydrogel not consisting of water. Incorporation of ALP in hydrogels followed by incubation in a solution containing calcium ions and glycerophosphate, a substrate for ALP, led to formation of calcium phosphate within the hydrogel. MG-63 osteoblast-like cells were cultivated in eluates from hydrogels containing ALP and without ALP at different dilutions and directly on the hydrogel samples. Hydrogels containing ALP exhibited superior cytocompatibility to ALP-free hydrogels. These results pave the way for the use of glycerol- and ALP-enriched hydrogels in bone regeneration.

  7. Cytokine-induced killer cells eradicate bone and soft-tissue sarcomas.

    Science.gov (United States)

    Sangiolo, Dario; Mesiano, Giulia; Gammaitoni, Loretta; Leuci, Valeria; Todorovic, Maja; Giraudo, Lidia; Cammarata, Cristina; Dell'Aglio, Carmine; D'Ambrosio, Lorenzo; Pisacane, Alberto; Sarotto, Ivana; Miano, Sara; Ferrero, Ivana; Carnevale-Schianca, Fabrizio; Pignochino, Ymera; Sassi, Francesco; Bertotti, Andrea; Piacibello, Wanda; Fagioli, Franca; Aglietta, Massimo; Grignani, Giovanni

    2014-01-01

    Unresectable metastatic bone sarcoma and soft-tissue sarcomas (STS) are incurable due to the inability to eradicate chemoresistant cancer stem-like cells (sCSC) that are likely responsible for relapses and drug resistance. In this study, we investigated the preclinical activity of patient-derived cytokine-induced killer (CIK) cells against autologous bone sarcoma and STS, including against putative sCSCs. Tumor killing was evaluated both in vitro and within an immunodeficient mouse model of autologous sarcoma. To identify putative sCSCs, autologous bone sarcoma and STS cells were engineered with a CSC detector vector encoding eGFP under the control of the human promoter for OCT4, a stem cell gene activated in putative sCSCs. Using CIK cells expanded from 21 patients, we found that CIK cells efficiently killed allogeneic and autologous sarcoma cells in vitro. Intravenous infusion of CIK cells delayed autologous tumor growth in immunodeficient mice. Further in vivo analyses established that CIK cells could infiltrate tumors and that tumor growth inhibition occurred without an enrichment of sCSCs relative to control-treated animals. These results provide preclinical proof-of-concept for an effective strategy to attack autologous sarcomas, including putative sCSCs, supporting the clinical development of CIK cells as a novel class of immunotherapy for use in settings of untreatable metastatic disease.

  8. The biocompatibility of carbon hydroxyapatite/β-glucan composite for bone tissue engineering studied with Raman and FTIR spectroscopic imaging.

    Science.gov (United States)

    Sroka-Bartnicka, Anna; Kimber, James A; Borkowski, Leszek; Pawlowska, Marta; Polkowska, Izabela; Kalisz, Grzegorz; Belcarz, Anna; Jozwiak, Krzysztof; Ginalska, Grazyna; Kazarian, Sergei G

    2015-10-01

    The spectroscopic approaches of FTIR imaging and Raman mapping were applied to the characterisation of a new carbon hydroxyapatite/β-glucan composite developed for bone tissue engineering. The composite is an artificial bone material with an apatite-forming ability for the bone repair process. Rabbit bone samples were tested with an implanted bioactive material for a period of several months. Using spectroscopic and chemometric methods, we were able to determine the presence of amides and phosphates and the distribution of lipid-rich domains in the bone tissue, providing an assessment of the composite's bioactivity. Samples were also imaged in transmission using an infrared microscope combined with a focal plane array detector. CaF2 lenses were also used on the infrared microscope to improve spectral quality by reducing scattering artefacts, improving chemometric analysis. The presence of collagen and lipids at the bone/composite interface confirmed biocompatibility and demonstrate the suitability of FTIR microscopic imaging with lenses in studying these samples. It confirmed that the composite is a very good background for collagen growth and increases collagen maturity with the time of the bone growth process. The results indicate the bioactive and biocompatible properties of this composite and demonstrate how Raman and FTIR spectroscopic imaging have been used as an effective tool for tissue characterisation.

  9. Cell-seeded scaffolds based on poly(ethylene oxide) and poly(butylene terephthalate) block copolymers for bone tissue engineering

    OpenAIRE

    Claase, Menno Bernard

    2004-01-01

    This thesis describes the development of polymeric scaffolds containing bone marrow stromal cells (BMSCs) that are cultured in an osteogenic medium and can be used for the formation of functional bone tissue upon implantation

  10. Ectopic osteogenesis and scaffold biodegradation of tissue engineering bone composed of chitosan and osteo-induced bone marrow mesenchymal stem cells in vivo

    Institute of Scientific and Technical Information of China (English)

    He Yiqun; Dong Youhai; Chen Xujun; Lin Rongqiang

    2014-01-01

    Background Chitosan (CS) scaffolds combined with osteogenically induced bone marrow mesenchymal stem cells (BMSCs) have been proved to be promising substitutes for repairing bone defects.Nevertheless,the bone-forming and scaffold-biodegrading processes are seldom studied.This study aimed to determine the osteogenic ability of CS/osteoinduced BMSC composites by observing the bone-forming process and explore the relationship between bone formation and scaffold biodegradation.Methods The CS/osteo-induced BMSC composites (CS+cells group) and the CS scaffolds (CS group) were,respectively,implanted into SD rat thigh muscles.At 2,4,6,8,and 12 weeks postoperatively,the rat femurs were scanned by CT,and the CT values of the implants were measured and comparatively analyzed.Subsequently,the implants were harvested and stained with hematoxylin and eosin and Masson trichrome,and the percentages of bone area,scaffold area,and collagen area were calculated and compared between the two groups.Results The imaging results showed that the densities of implants of the two groups gradually increased along with time,but the CT values of implants in the CS+cells group were much higher than in the CS group at the same time point (P <0.05).The histological results showed that the de novo bone and collagen formed in the pores of the scaffolds and gradually increased since 2 weeks postoperation in both groups,and the scaffold gradually degraded along with the boneforming process.However,the comparative analysis results showed that the CS+cells group gained more de novo bone and collagen formation and had less scaffold than the CS group at the same time point (P <0.05).Conclusion The CS/osteo-induced BMSC composites are excellent bone tissue engineering substitutes,and the scaffold biodegradation is accordant with the bone formation.

  11. A magnetic resonance imaging study on changes in rat mandibular bone marrow and pulp tissue after high-dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wan; Lee, Byung Do [Dept. of Oral and Maxillofacial Radiology and Wonkwang Dental Research Institute, College of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Lee, Kang Kyoo [Dept. of Radiation Oncology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju (Korea, Republic of)

    2014-03-15

    This study was designed to evaluate whether magnetic resonance imaging (MRI) is appropriate for detecting early changes in the mandibular bone marrow and pulp tissue of rats after high-dose irradiation. The right mandibles of Sprague-Dawley rats were irradiated with 10 Gy (Group 1, n=5) and 20 Gy (Group 2, n=5). Five non-irradiated animals were used as controls. The MR images of rat mandibles were obtained before irradiation and once a week until week 4 after irradiation. From the MR images, the signal intensity (SI) of the mandibular bone marrow and pulp tissue of the incisor was interpreted. The MR images were compared with the histopathologic findings. The SI of the mandibular bone marrow had decreased on T2-weighted MR images. There was little difference between Groups 1 and 2. The SI of the irradiated groups appeared to be lower than that of the control group. The histopathologic findings showed that the trabecular bone in the irradiated group had increased. The SI of the irradiated pulp tissue had decreased on T2-weighted MR images. However, the SI of the MR images in Group 2 was high in the atrophic pulp of the incisor apex at week 2 after irradiation. These patterns seen on MRI in rat bone marrow and pulp tissue were consistent with histopathologic findings. They may be useful to assess radiogenic sclerotic changes in rat mandibular bone marrow.

  12. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering.

    Science.gov (United States)

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A; Janeczek, Agnieszka A; Kontouli, Nasia; Kanczler, Janos M; Evans, Nicholas D; Oreffo, Richard Oc

    2016-08-31

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p < 0.01). This human-avian system offers a simple refinement model for animal research and a step towards a humanized in vivo model for tissue engineering.

  13. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering

    Science.gov (United States)

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A.; Janeczek, Agnieszka A.; Kontouli, Nasia; Kanczler, Janos M.; Evans, Nicholas D.; Oreffo, Richard Oc

    2016-08-01

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p animal research and a step towards a humanized in vivo model for tissue engineering.

  14. Changes in functional activity of bone tissue cells under space flight conditions.

    Science.gov (United States)

    Rodionova, Natalia; Nesterenko, Olga; Kabitskaya, Olga

    The space flight conditions affect considerably the state of bone tissue, leading to the development of osteoporosis and osteopenia. Many aspects of reactions of bone tissue cells still remain unclear until now. With the use of electron microscopy we studied the samples gathered from the femoral bonеs metaphyses of rats flown on board the space laboratory (Spacelab - 2) during 2 weeks and samples from tibial bones of mice C57 Black ( Bion М-1). It was established, that under microgravity conditions there occur remodelling processes in a spongy bone related with a deficit of support load. In this work the main attention is focused on studying the ultrastructure of osteogenetic cells and osteoclasts. The degree of differentiation and functional state are evaluated according to the degree of development of organelles for specific biosynthesis: rough endoplasmic reticulum (RER), Golgy complex (GC), as well as the state of mitochondria and cell nucleus. As compared with a synchronous control, the population of osteogenetic cells from zones of bone reconstruction shows a decrease in the number of functionally active forms. We can judge of this from the reduction of a specific volume of RER, GC, mitochondria in osteoblasts. RER loses architectonics typical for osteoblasts and, as against the control, is represented by short narrow canaliculi distributed throughout the cytoplasm; some canals disintegrate. GC is slightly pronounced, mitochondria become smaller in size and acquire an optically dark matrix. These phenomena are supposed to be associated with the desorganization of microtubules and microfilaments in the cells under microgravity conditions. The population of osteogenetic cells shows a decrease in the number of differentiating osteoblasts and an increase in the number of little-differentiated stromal cells. In the population of osteoblasts, degrading and apoptotic cells are sometimes encountered. Such zones show a numerical increase of monocytic cells and

  15. Carpal Tunnel Cross-Sectional Area Affected by Soft Tissues Abutting the Carpal Bones.

    Science.gov (United States)

    Gabra, Joseph N; Li, Zong-Ming

    2013-02-01

    The carpal tunnel accommodates free movement of its contents, and the tunnel's cross-sectional area is a useful morphological parameter for the evaluation of the space available for the carpal tunnel contents and of potential nerve compression in the tunnel. The osseous boundary of the carpal bones as the dorsal border of the carpal tunnel is commonly used to determine the tunnel area, but this boundary contains soft tissues such as numerous intercarpal ligaments and the flexor carpi radialis tendon. The aims of this study were to quantify the thickness of the soft tissues abutting the carpal bones and to investigate how this soft tissue influences the calculation of the carpal tunnel area. Magnetic resonance images were analyzed for eight cadaveric specimens. A medical balloon with a physiological pressure was inserted into an evacuated tunnel to identify the carpal tunnel boundary. The balloon-based (i.e. true carpal tunnel) and osseous-based carpal tunnel boundaries were extracted and divided into regions corresponding to the hamate, capitate, trapezoid, trapezium, and transverse carpal ligament (TCL). From the two boundaries, the overall and regional soft tissue thicknesses and areas were calculated. The soft tissue thickness was significantly greater for the trapezoid (3.1±1.2mm) and trapezium (3.4±1.0mm) regions than for the hamate (0.7±0.3mm) and capitate (1.2±0.5mm) regions. The carpal tunnel area using the osseous boundary (243.0±40.4mm(2)) was significantly larger than the balloon-based area (183.9±29.7mm(2)) with a ratio of 1.32. In other words, the carpal tunnel area can be estimated as 76% (= 1/1.32) of the osseous-based area. The abundance of soft tissue in the trapezoid and trapezium regions can be attributed mainly to the capitate-trapezium ligament and the flexor carpi radialis tendon. Inclusion of such soft tissue leads to overestimations of the carpal tunnel area. Correct quantification of the carpal tunnel area aids in examining carpal

  16. Perovskite ceramic nanoparticles in polymer composites for augmenting bone tissue regeneration

    Science.gov (United States)

    Bagchi, Amrit; Rama Krishna Meka, Sai; Narayana Rao, Badari; Chatterjee, Kaushik

    2014-12-01

    There is increasing interest in the use of nanoparticles as fillers in polymer matrices to develop biomaterials which mimic the mechanical, chemical and electrical properties of bone tissue for orthopaedic applications. The objective of this study was to prepare poly(ɛ-caprolactone) (PCL) nanocomposites incorporating three different perovskite ceramic nanoparticles, namely, calcium titanate (CT), strontium titanate (ST) and barium titanate (BT). The tensile strength and modulus of the composites increased with the addition of nanoparticles. Scanning electron microscopy indicated that dispersion of the nanoparticles scaled with the density of the ceramics, which in turn played an important role in determining the enhancement in mechanical properties of the composite. Dielectric spectroscopy revealed improved permittivity and reduced losses in the composites when compared to neat PCL. Nanofibrous scaffolds were fabricated via electrospinning. Induction coupled plasma-optical emission spectroscopy indicated the release of small quantities of Ca+2, Sr+2, Ba+2 ions from the scaffolds. Piezo-force microscopy revealed that BT nanoparticles imparted piezoelectric properties to the scaffolds. In vitro studies revealed that all composites support osteoblast proliferation. Expression of osteogenic genes was enhanced on the nanocomposites in the following order: PCL/CT > PCL/ST > PCL/BT > PCL. This study demonstrates that the use of perovskite nanoparticles could be a promising technique to engineer better polymeric scaffolds for bone tissue engineering.

  17. Bone Tissue Engineering by Using Calcium Phosphate Glass Scaffolds and the Avidin-Biotin Binding System.

    Science.gov (United States)

    Kim, Min-Chul; Hong, Min-Ho; Lee, Byung-Hyun; Choi, Heon-Jin; Ko, Yeong-Mu; Lee, Yong-Keun

    2015-12-01

    Highly porous and interconnected scaffolds were fabricated using calcium phosphate glass (CPG) for bone tissue engineering. An avidin-biotin binding system was used to improve osteoblast-like cell adhesion to the scaffold. The scaffolds had open macro- and micro-scale pores, and continuous struts without cracks or defects. Scaffolds prepared using a mixture (amorphous and crystalline CPG) were stronger than amorphous group and crystalline group. Cell adhesion assays showed that more cells adhered, with increasing cell seeding efficiency to the avidin-adsorbed scaffolds, and that cell attachment to the highly porous scaffolds significantly differed between avidin-adsorbed scaffolds and other scaffolds. Proliferation was also significantly higher for avidin-adsorbed scaffolds. Osteoblastic differentiation of MG-63 cells was observed at 3 days, and MG-63 cells in direct contact with avidin-adsorbed scaffolds were positive for type I collagen, osteopontin, and alkaline phosphatase gene expression. Osteocalcin expression was observed in the avidin-adsorbed scaffolds at 7 days, indicating that cell differentiation in avidin-adsorbed scaffolds occurred faster than the other scaffolds. Thus, these CPG scaffolds have excellent biological properties suitable for use in bone tissue engineering.

  18. High-density polytetrafluoroethylene membranes in guided bone and tissue regeneration procedures: a literature review.

    Science.gov (United States)

    Carbonell, J M; Martín, I Sanz; Santos, A; Pujol, A; Sanz-Moliner, J D; Nart, J

    2014-01-01

    Expanded polytetrafluoroethylene (e-PTFE) has been used successfully as a membrane barrier for regeneration procedures. However, when exposed to the oral cavity, its high porosity increases the risk of early infection, which can affect surgical outcomes. An alternative to e-PTFE is non-expanded and dense polytetrafluoroethylene (n-PFTE), which results in lower levels of early infection following surgical procedures. The aim of this literature review was to analyze and describe the available literature on n-PFTE, report the indications for use, advantages, disadvantages, surgical protocols, and complications. The medical databases Medline-PubMed and Cochrane Library were searched and supplemented with a hand search for reports published between 1980 and May 2012 on n-PTFE membranes. The search strategy was limited to animal, human, and in vitro studies in dental journals published in English. Twenty-four articles that analyzed the use of n-PTFE as a barrier membrane for guided tissue regeneration and guided bone regeneration around teeth and implants were identified: two in vitro studies, seven experimental studies, and 15 clinical studies. There is limited clinical and histological evidence for the use of n-PTFE membranes at present, with some indications in guided tissue regeneration and guided bone regeneration in immediate implants and fresh extraction sockets.

  19. Carboxymethyl cellulose enables silk fibroin nanofibrous scaffold with enhanced biomimetic potential for bone tissue engineering application.

    Science.gov (United States)

    Singh, B N; Panda, N N; Mund, R; Pramanik, K

    2016-10-20

    Novel silk fibroin (SF) and carboxymethyl cellulose (CMC) composite nanofibrous scaffold (SFC) were developed to investigate their ability to nucleate bioactive nanosized calcium phosphate (Ca/P) by biomineralization for bone tissue engineering application. The composite nanofibrous scaffold was prepared by free liquid surface electrospinning method. The developed composite nanofibrous scaffold was observed to control the size of Ca/P particle (≤100nm) as well as uniform nucleation of Ca/P over the surface. The obtained nanofibrous scaffolds were fully characterized for their functional, structural and mechanical property. The XRD and EDX analysis depicted the development of apatite like crystals over SFC scaffolds of nanospherical in morphology and distributed uniformly throughout the surface of scaffold. Additionally, hydrophilicity as a measure of contact angle and water uptake capacity is higher than pure SF scaffold representing the superior cell supporting property of the SF/CMC scaffold. The effect of biomimetic Ca/P on osteogenic differentiation of umbilical cord blood derived human mesenchymal stem cells (hMSCs) studied in early and late stage of differentiation shows the improved osteoblastic differentiation capability as compared to pure silk fibroin. The obtained result confirms the positive correlation of alkaline phosphatase activity, alizarin staining and expression of runt-related transcription factor 2, osteocalcin and type1 collagen representing the biomimetic property of the scaffolds. Thus, the developed composite has been demonstrated to be a potential scaffold for bone tissue engineering application.

  20. A comparison of bioreactors for culture of fetal mesenchymal stem cells for bone tissue engineering.

    Science.gov (United States)

    Zhang, Zhi-Yong; Teoh, Swee Hin; Teo, Erin Yiling; Khoon Chong, Mark Seow; Shin, Chong Woon; Tien, Foo Toon; Choolani, Mahesh A; Chan, Jerry K Y

    2010-11-01

    Bioreactors provide a dynamic culture system for efficient exchange of nutrients and mechanical stimulus necessary for the generation of effective tissue engineered bone grafts (TEBG). We have shown that biaxial rotating (BXR) bioreactor-matured human fetal mesenchymal stem cell (hfMSC) mediated-TEBG can heal a rat critical sized femoral defect. However, it is not known whether optimal bioreactors exist for bone TE (BTE) applications. We systematically compared this BXR bioreactor with three most commonly used systems: Spinner Flask (SF), Perfusion and Rotating Wall Vessel (RWV) bioreactors, for their application in BTE. The BXR bioreactor achieved higher levels of cellularity and confluence (1.4-2.5x, p bioreactors operating in optimal settings. BXR bioreactor-treated scaffolds experienced earlier and more robust osteogenic differentiation on von Kossa staining, ALP induction (1.2-1.6×, p bioreactor-treated grafts, but not with the other three. BXR bioreactor enabled superior cellular proliferation, spatial distribution and osteogenic induction of hfMSC over other commonly used bioreactors. In addition, we developed and validated a non-invasive quantitative micro CT-based technique for analyzing neo-tissue formation and its spatial distribution within scaffolds.

  1. In vitro Evaluation of Natural Marine Sponge Collagen as a Scaffold for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Zhen Lin, Kellie L. Solomon, Xiaoling Zhang, Nathan J. Pavlos, Tamara Abel, Craig Willers, Kerong Dai, Jiake Xu, Qiujian Zheng, Minghao Zheng

    2011-01-01

    Full Text Available The selection of a suitable scaffold matrix is critical for cell-based bone tissue engineering. This study aimed to identify and characterize natural marine sponges as potential bioscaffolds for osteogenesis. Callyspongiidae marine sponge samples were collected from the Fremantle coast of Western Australia. The sponge structure was assessed using scanning electron microscopy (SEM and Hematoxylin and eosin. Mouse primary osteoblasts were seeded onto the sponge scaffold and immunostained with F-actin to assess cell attachment and aggregation. Alkaline phosphatase expression, von Kossa staining and real-time PCR were performed to examine the osteogenic potential of sponge samples. SEM revealed that the sponge skeleton possessed a collagenous fibrous network consisting of interconnecting channels and a porous structure that support cellular adhesion, aggregation and growth. The average pore size of the sponge skeleton was measured 100 to 300 μm in diameter. F-actin staining demonstrated that osteoblasts were able to anchor onto the surface of collagen fibres. Alkaline phosphatase expression, a marker of early osteoblast differentiation, was evident at 7 days although expression decreased steadily with long term culture. Using von Kossa staining, mineralisation nodules were evident after 21 days. Gene expression of osteoblast markers, osteocalcin and osteopontin, was also observed at 7, 14 and 21 days of culture. Together, these results suggest that the natural marine sponge is promising as a new scaffold for use in bone tissue engineering.

  2. Brain Metastasis in Bone and Soft Tissue Cancers: A Review of Incidence, Interventions, and Outcomes

    Directory of Open Access Journals (Sweden)

    Faris Shweikeh

    2014-01-01

    Full Text Available Bone and soft tissue malignancies account for a small portion of brain metastases. In this review, we characterize their incidence, treatments, and prognosis. Most of the data in the literature is based on case reports and small case series. Less than 5% of brain metastases are from bone and soft tissue sarcomas, occurring most commonly in Ewing’s sarcoma, malignant fibrous tumors, and osteosarcoma. Mean interval from initial cancer diagnosis to brain metastasis is in the range of 20–30 months, with most being detected before 24 months (osteosarcoma, Ewing sarcoma, chordoma, angiosarcoma, and rhabdomyosarcoma, some at 24–36 months (malignant fibrous tumors, malignant peripheral nerve sheath tumors, and alveolar soft part sarcoma, and a few after 36 months (chondrosarcoma and liposarcoma. Overall mean survival ranges between 7 and 16 months, with the majority surviving < 12 months (Ewing’s sarcoma, liposarcoma, malignant fibrous tumors, malignant peripheral nerve sheath tumors, angiosarcoma and chordomas. Management is heterogeneous involving surgery, radiosurgery, radiotherapy, and chemotherapy. While a survival advantage may exist for those given aggressive treatment involving surgical resection, such patients tended to have a favorable preoperative performance status and minimal systemic disease.

  3. Tuning polycaprolactone-carbon nanotube composites for bone tissue engineering scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Mattioli-Belmonte, Monica [Department of Clinical and Molecular Sciences, Faculty of Medicine, Marche Polytechnic University, Via Tronto 10/a, 60126 Ancona (Italy); Vozzi, Giovanni, E-mail: g.vozzi@ing.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Materials Science, University of Pisa, Via Diotisalvi 2, 56126 Pisa (Italy); Interdepartmental Research ' E. Piaggio' , University of Pisa, Via Diotisalvi 2, 56126 Pisa (Italy); Whulanza, Yudan [Interdepartmental Research ' E. Piaggio' , University of Pisa, Via Diotisalvi 2, 56126 Pisa (Italy); Seggiani, Maurizia [Department of Chemical Engineering, Industrial Chemistry and Materials Science, University of Pisa, Via Diotisalvi 2, 56126 Pisa (Italy); Fantauzzi, Valentina [Interdepartmental Research ' E. Piaggio' , University of Pisa, Via Diotisalvi 2, 56126 Pisa (Italy); Orsini, Giovanna [Department of Clinic Specialised and Odontostomatological Sciences, Marche Polytechnic University, Via Tronto 10/A, 60020 Ancona (Italy); Ahluwalia, Arti [Interdepartmental Research ' E. Piaggio' , University of Pisa, Via Diotisalvi 2, 56126 Pisa (Italy)

    2012-02-01

    This report describes the mechanical, thermal and biological characterisation of a solid free form microfabricated carbon nanotube-polycaprolactone composite, in which both the quantity of nanotubes in the matrix as well as the scaffold design were varied in order to tune the mechanical properties of the material. The creep and stress relaxation behaviour of the composite material was analysed to identify an optimal composition for bone tissue engineering. Moreover, the morphology and viability of osteoblast-like cells (MG63) on composite scaffolds were analysed using scanning electron microscopy and MTT assays. Our data demonstrate that by changing the ratio of CNT to PCL, the elastic modulus of the nanocomposite can be varied between 10 and 75 MPa. In this range, the geometry of the scaffold can be used to finely tune its stiffness. However our PCL-CNT nanocomposites were able to sustain osteoblast proliferation and modulate cell morphology. Thus we show the potential of custom designed CNT nanocomposites for bone tissue engineering. - Highlights: Black-Right-Pointing-Pointer Microfabricated carbon nanotube-polycaprolactone composite scaffold was realised. Black-Right-Pointing-Pointer Mechanical, thermal and biological characterisation were performed. Black-Right-Pointing-Pointer PCL-CNT nanocomposite scaffolds were able to sustain osteoblast proliferation. Black-Right-Pointing-Pointer Composite scaffolds were able to modulate cell morphology.

  4. Nanoparticulate bioactive-glass-reinforced gellan-gum hydrogels for bone-tissue engineering.

    Science.gov (United States)

    Gantar, Ana; da Silva, Lucilia P; Oliveira, Joaquim M; Marques, Alexandra P; Correlo, Vitor M; Novak, Saša; Reis, Rui L

    2014-10-01

    This work presents bioactive-glass-reinforced gellan-gum spongy-like hydrogels (GG-BAG) as novel hydrophilic materials for use as the scaffolding in bone-tissue engineering. The reinforcement with bioactive-glass particles resulted in an improvement to the microstructure and to the mechanical properties of the material. These mechanical properties were found to be dependent on the composition and improved with the amount of bioactive glass; however, values necessary to accommodate biomechanical loading were not achieved in this study. Nevertheless, by incorporating the bioactive-glass particles, the composite material acquired the ability to form an apatite layer when soaked in simulated body fluid. Furthermore, human-adipose-derived stem cells were able to adhere and spread within the gellan-gum, spongy-like hydrogels reinforced with the bioactive glass, and remain viable, which is an important result when considering their use in bone-tissue engineering. Thus, hydrogels based on gellan gum and bioactive glass are promising biomaterials for use either alone or with cells, and with the potential for use in osteogenic differentiation.

  5. Relation of Visceral and Subcutaneous Adipose Tissue to Bone Mineral Density in Chinese Women

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2013-01-01

    Full Text Available The relationship between adipose and bone tissues is still being debated. The purpose of our study was to evaluate whether the distribution and volume of abdomen adipose tissue are correlated to trabecular bone mineral density in the lumbar spine. In this cross-sectional study, 320 Chinese women, being divided into two groups according to age ≥55 years and <55 years, were evaluated with quantitative computed tomography (QCT of the spine to simultaneously evaluate the average trabecular BMD of L2–L4, VAT, and SAT. Possible covariates of height, weight, age, and comorbidities were considered. In the <55-year-old sample, multiple linear regression analyses indicated that VAT volume was negatively correlated to trabecular BMD (P value = 0.0003 and SAT volume had no correlation to trabecular BMD. In contrast, there was no significant correlation between VAT or SAT and BMD in the ≥55-year-old sample. Our results indicate that high VAT volume is associated with low BMD in Chinese women aged <55 years and SAT has no relation with BMD.

  6. Fabrication of PLLA/β-TCP nanocomposite scaffolds with hierarchical porosity for bone tissue engineering.

    Science.gov (United States)

    Lou, Tao; Wang, Xuejun; Song, Guojun; Gu, Zheng; Yang, Zhen

    2014-08-01

    Polymer and ceramic composite scaffolds play a crucial role in bone tissue engineering. In an attempt to mimic the architecture of natural extracellular matrix (ECM), poly(l-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) nanocomposite scaffolds with a hierarchical pore structure were fabricated by combining thermal induced phase separation and salt leaching techniques. The nanocomposite scaffold consisted of a nanofibrous PLLA matrix with a highly interconnected, high porosity (>93%) hierarchical pore structure with pore diameters ranging from 500nm to 300μm and a homogeneously distributed β-TCP nanoparticle phase. The nanofibrous PLLA matrix had a fiber diameter of 70-300nm. The nanocomposite scaffolds possess three levels of hierarchical structure: (1) porosity; (2) nanofibrous PLLA struts comprising the pore walls; and (3) β-TCP nanoparticle phase. The β-TCP nanoparticle phase improved the mechanical properties and bioactivity of the PLLA matrix. The nanocomposite scaffolds supported MG-63 osteoblast proliferation, penetration, and ECM deposition, indicating the potential of PLLA/β-TCP nanocomposite scaffolds with hierarchical porosity for bone tissue engineering applications.

  7. Fabrication of highly porous biodegradable biomimetic nanocomposite as advanced bone tissue scaffold

    Directory of Open Access Journals (Sweden)

    Abdalla Abdal-hay

    2017-02-01

    Full Text Available Development of bioinspired or biomimetic materials is currently a challenge in the field of tissue regeneration. In-situ 3D biomimetic microporous nanocomposite scaffold has been developed using a simple lyophilization post hydrothermal reaction for bone healing applications. The fabricated 3D porous scaffold possesses advantages of good bonelike apatite particles distribution, thermal properties and high porous interconnected network structure. High dispersion bonelike apatite nanoparticles (NPs rapidly nucleated and deposited from surrounding biological minerals within chitosan (CTS matrices using hydrothermal technique. After that, freeze-drying method was applied on the composite solution to form the desired porous 3D architecture. Interestingly, the porosity and pore size of composite scaffold were not significantly affected by the particles size and particles content within the CTS matrix. Our results demonstrated that the compression modulus of porous composite scaffold is twice higher than that of plain CTS scaffold, indicating a maximization of the chemical interaction between polymer matrix and apatite NPs. Cytocompatibility test for MC3T3-E1 pre-osteoblasts cell line using MTT-indirect assay test showed that the fabricated 3D microporous nanocomposite scaffold possesses higher cell proliferation and growth than that of pure CTS scaffold. Collectively, our results suggest that the newly developed highly porous apatite/CTS nanocomposite scaffold as an alternative of hydroxyapatite/CTS scaffold may serve as an excellent porous 3D platform for bone tissue regeneration.

  8. Electrospun hydroxyapatite-containing chitosan nanofibers crosslinked with genipin for bone tissue engineering.

    Science.gov (United States)

    Frohbergh, Michael E; Katsman, Anna; Botta, Gregory P; Lazarovici, Phillip; Schauer, Caroline L; Wegst, Ulrike G K; Lelkes, Peter I

    2012-12-01

    Reconstruction of large bone defects remains problematic in orthopedic and craniofacial clinical practice. Autografts are limited in supply and are associated with donor site morbidity while other materials show poor integration with the host's own bone. This lack of integration is often due to the absence of periosteum, the outer layer of bone that contains osteoprogenitor cells and is critical for the growth and remodeling of bone tissue. In this study we developed a one-step platform to electrospin nanofibrous scaffolds from chitosan, which also contain hydroxyapatite nanoparticles and are crosslinked with genipin. We hypothesized that the resulting composite scaffolds represent a microenvironment that emulates the physical, mineralized structure and mechanical properties of non-weight bearing bone extracellular matrix while promoting osteoblast differentiation and maturation similar to the periosteum. The ultrastructure and physicochemical properties of the scaffolds were studied using scanning electron microscopy and spectroscopic techniques. The average fiber diameters of the electrospun scaffolds were 227 ± 154 nm as spun, and increased to 335 ± 119 nm after crosslinking with genipin. Analysis by X-ray diffraction, Fourier transformed infrared spectroscopy and energy dispersive spectroscopy confirmed the presence of characteristic features of hydroxyapatite in the composite chitosan fibers. The Young's modulus of the composite fibrous scaffolds was 142 ± 13 MPa, which is similar to that of the natural periosteum. Both pure chitosan scaffolds and composite hydroxyapatite-containing chitosan scaffolds supported adhesion, proliferation and osteogenic differentiation of mouse 7F2 osteoblast-like cells. Expression and enzymatic activity of alkaline phosphatase, an early osteogenic marker, were higher in cells cultured on the composite scaffolds as compared to pure chitosan scaffolds, reaching a significant, 2.4 fold, difference by day 14 (p < 0

  9. Osteogenic potential of porous {beta}-tricalcium phosphate ({beta}-TCP) combined with cultured bone. Tissue engineered bone using a biodegradable material as a scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Fu, S.; Yamada, Y.; Honda, M.; Ueda, M. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Yoshikawa, T. [Nara Medical Univ. (Japan). First Dept. of Pathology; Hibino, Y.; Hata, K. [Nagoya Univ. (Japan). Dept. of Tissue Engineering; Niimi, A. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Chunichi Hospital (Japan). Dept. of Oral and Maxillofacial Surgery; Okazaki, Y. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Nagoya Univ. (Japan). Dept. of Tissue Engineering

    2001-07-01

    Recently, the tissue engineering approach has widespread attention for regeneration. The present study was undertaken to evaluate whether biodegradable porous {beta}-tricalcium phosphate ({beta}-TCP) can be used as a scaffold for cultured bone marrow cells or not. Marrow cells were obtained from bone shaft of rat femur and cultured in a standard medium for 10 days, then trypsinized to combine cells with ceramics. An additional subculture was done for cells/ceramics composite in a standard medium with the addition of {beta}-glycerophosphate, ascorbic acid and dexamethason. The 20 day subcultured composites were implanted into subcutaneous sites of syngeneic rats. These implants were harvested at 4 and 8 weeks postimplantation, and prepared for the histological analysis. In the histological analysis of composites at 4 weeks postimplantation, active bone formation could be found in the composites. The bone formation was evidenced by active osteoblast lining on the surfaces of bone. At 8 weeks, more extensive bone formation was observed in the composites. These results suggested that beta-TCP could play a role as scaffold of tissueengineered bone derived from marrow cells. (orig.)

  10. Hybrid scaffold bearing polymer-siloxane Schiff base linkage for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Bindu P., E-mail: bindumelekkuttu@gmail.com; Gangadharan, Dhanya; Mohan, Neethu; Sumathi, Babitha; Nair, Prabha D., E-mail: pdnair49@gmail.com

    2015-07-01

    Scaffolds that can provide the requisite biological cues for the fast regeneration of bone are highly relevant to the advances in tissue engineering and regenerative medicine. In the present article, we report the fabrication of a chitosan–gelatin–siloxane scaffold bearing interpolymer-siloxane Schiff base linkage, through a single-step dialdehyde cross-linking and freeze-drying method using 3-aminopropyltriethoxysilane as the siloxane precursor. Swelling of the scaffolds in phosphate buffered saline indicates enhancement with increase in siloxane concentration, whereas compressive moduli of the wet scaffolds reveal inverse dependence, owing to the presence of siloxane, rich in silanol groups. It is suggested that through the strategy of dialdehyde cross-linking, a limiting siloxane loading of 20 wt.% into a chitosan-gelatin matrix should be considered ideal for bone tissue engineering, because the scaffold made with 30 wt.% siloxane loading degrades by 48 wt.%, in 21 days. The hybrid scaffolds bearing Schiff base linkage between the polymer and siloxane, unlike the stable linkages in earlier reports, are expected to give a faster release of siloxanes and enhancement in osteogenesis. This is verified by the in vitro evaluation of the hybrid scaffolds using rabbit adipose mesenchymal stem cells, which revealed osteogenic cell-clusters on a polymer-siloxane scaffold, enhanced alkaline phosphatase activity and the expression of bone-specific genes, whereas the control scaffold without siloxane supported more of cell-proliferation than differentiation. A siloxane concentration dependent enhancement in osteogenic differentiation is also observed. - Highlights: • A hybrid scaffold bearing interpolymer-siloxane Schiff base linkage • A limiting siloxane loading of 20 wt.% into chitosan–gelatin matrix • A siloxane concentration dependent enhancement in osteogenic differentiation.

  11. TU-B-210-01: MRg HIFU - Bone and Soft Tissue Tumor Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Ghanouni, P. [Stanford University (United States)

    2015-06-15

    MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advanced techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips.

  12. Laser Sintered Magnesium-Calcium Silicate/Poly-ε-Caprolactone Scaffold for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Kuo-Yang Tsai

    2017-01-01

    Full Text Available In this study, we manufacture and analyze bioactive magnesium–calcium silicate/poly-ε-caprolactone (Mg–CS/PCL 3D scaffolds for bone tissue engineering. Mg–CS powder was incorporated into PCL, and we fabricated the 3D scaffolds using laser sintering technology. These scaffolds had high porosity and interconnected-design macropores and structures. As compared to pure PCL scaffolds without an Mg–CS powder, the hydrophilic properties and degradation rate are also improved. For scaffolds with more than 20% Mg–CS content, the specimens become completely covered by a dense bone-like apatite layer after soaking in simulated body fluid for 1 day. In vitro analyses were directed using human mesenchymal stem cells (hMSCs on all scaffolds that were shown to be biocompatible and supported cell adhesion and proliferation. Increased focal adhesion kinase and promoted cell adhesion behavior were observed after an increase in Mg–CS content. In addition, the results indicate that the Mg–CS quantity in the composite is higher than 10%, and the quantity of cells and osteogenesis-related protein of hMSCs is stimulated by the Si ions released from the Mg–CS/PCL scaffolds when compared to PCL scaffolds. Our results proved that 3D Mg–CS/PCL scaffolds with such a specific ionic release and good degradability possessed the ability to promote osteogenetic differentiation of hMSCs, indicating that they might be promising biomaterials with potential for next-generation bone tissue engineering scaffolds.

  13. Complementary Physical and Mechanical Techniques to Characterise Tooth: A Bone-like Tissue

    Institute of Scientific and Technical Information of China (English)

    Peter Zioupos; Keith D. Rogers

    2006-01-01

    Bone like tissues are biocomposites comprising an organic matrix (mostly collagen) and a reinforcement phase in the form of mineral crystals (poorly stoichiometric apatite). The composite properties are a result of the material characteristics of the two phases, their interaction, the relative composition, the orientation and the micro-architecture of the structure. The inherent spatial heterogeneity of these tissues (a result of evolutionary and functional requirements) and their exposure to various environmental and mechanical influences result in highly variable properties on the microscale, which can only be characterised by modern microanalytical methods. We present here results obtained by the complementary use of the modern nanoindentation and micro-X-ray diffraction techniques, which were used to probe the properties and structure of human dentine and enamel of primary molar teeth. The results show that both the addition and the higher organization of mineral within the organic matrix produce stiffer and harder tissue and that the examination of properties within small tissue volumes can be reliably achieved by use of these two methods in parallel. This opens new avenues in the study of biomaterial in general, and for the local characterisation of regions of teeth that suffered bacterial attack, mechanical wear, fluoridisation, chemical bleaching, or dental treatment such as laser ablation or drilling.

  14. Dose equivalent near the bone-soft tissue interface from nuclear fragments produced by high-energy protons

    Science.gov (United States)

    Shavers, M. R.; Poston, J. W.; Cucinotta, F. A.; Wilson, J. W.

    1996-01-01

    During manned space missions, high-energy nucleons of cosmic and solar origin collide with atomic nuclei of the human body and produce a broad linear energy transfer spectrum of secondary particles, called target fragments. These nuclear fragments are often more biologically harmful than the direct ionization of the incident nucleon. That these secondary particles increase tissue absorbed dose in regions adjacent to the bone-soft tissue interface was demonstrated in a previous publication. To assess radiological risks to tissue near the bone-soft tissue interface, a computer transport model for nuclear fragments produced by high energy nucleons was used in this study to calculate integral linear energy transfer spectra and dose equivalents resulting from nuclear collisions of 1-GeV protons transversing bone and red bone marrow. In terms of dose equivalent averaged over trabecular bone marrow, target fragments emitted from interactions in both tissues are predicted to be at least as important as the direct ionization of the primary protons-twice as important, if recently recommended radiation weighting factors and "worst-case" geometry are used. The use of conventional dosimetry (absorbed dose weighted by aa linear energy transfer-dependent quality factor) as an appropriate framework for predicting risk from low fluences of high-linear energy transfer target fragments is discussed.

  15. Testing the Hypothesis of Biofilm as a Source for Soft Tissue and Cell-Like Structures Preserved in Dinosaur Bone.

    Science.gov (United States)

    Schweitzer, Mary Higby; Moyer, Alison E; Zheng, Wenxia

    2016-01-01

    Recovery of still-soft tissue structures, including blood vessels and osteocytes, from dinosaur bone after demineralization was reported in 2005 and in subsequent publications. Despite multiple lines of evidence supporting an endogenous source, it was proposed that these structures arose from contamination from biofilm-forming organisms. To test the hypothesis that soft tissue structures result from microbial invasion of the fossil bone, we used two different biofilm-forming microorganisms to inoculate modern bone fragments from which organic components had been removed. We show fundamental morphological, chemical and textural differences between the resultant biofilm structures and those derived from dinosaur bone. The data do not support the hypothesis that biofilm-forming microorganisms are the source of these structures.

  16. Mechanical and biological properties of the micro-/nano-grain functionally graded hydroxyapatite bioceramics for bone tissue engineering.

    Science.gov (United States)

    Zhou, Changchun; Deng, Congying; Chen, Xuening; Zhao, Xiufen; Chen, Ying; Fan, Yujiang; Zhang, Xingdong

    2015-08-01

    Functionally graded materials (FGM) open the promising approach for bone tissue repair. In this study, a novel functionally graded hydroxyapatite (HA) bioceramic with micrograin and nanograin structure was fabricated. Its mechanical properties were tailored by composition of micrograin and nanograin. The dynamic mechanical analysis (DMA) indicated that the graded HA ceramics had similar mechanical property compared to natural bones. Their cytocompatibility was evaluated via fluorescent microscopy and MTT colorimetric assay. The viability and proliferation of rabbit bone marrow mesenchymal stem cells (BMSCs) on ceramics indicated that this functionally graded HA ceramic had better cytocompatibility than conventional HA ceramic. This study demonstrated that functionally graded HA ceramics create suitable structures to satisfy both the mechanical and biological requirements of bone tissues.

  17. Testing the Hypothesis of Biofilm as a Source for Soft Tissue and Cell-Like Structures Preserved in Dinosaur Bone.

    Directory of Open Access Journals (Sweden)

    Mary Higby Schweitzer

    Full Text Available Recovery of still-soft tissue structures, including blood vessels and osteocytes, from dinosaur bone after demineralization was reported in 2005 and in subsequent publications. Despite multiple lines of evidence supporting an endogenous source, it was proposed that these structures arose from contamination from biofilm-forming organisms. To test the hypothesis that soft tissue structures result from microbial invasion of the fossil bone, we used two different biofilm-forming microorganisms to inoculate modern bone fragments from which organic components had been removed. We show fundamental morphological, chemical and textural differences between the resultant biofilm structures and those derived from dinosaur bone. The data do not support the hypothesis that biofilm-forming microorganisms are the source of these structures.

  18. Bone

    Science.gov (United States)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

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

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

    OpenAIRE

    Haghighati F; Akbari S

    2006-01-01

    Background and Aim: Increasing patient demands for esthetic, put the root coverage procedures in particular attention. Periodontal regeneration with GTR based root coverage methods is the most common treatment used. The purpose of this study was to compare guided tissue regeneration (GTR) with collagen membrane and a bone graft, with sub-epithelial connective tissue graft (SCTG), in treatment of gingival recession. Materials and Methods: In this randomized clinical trial study, eleven healthy...

  20. Energy deposition at the bone-tissue interface from nuclear fragments produced by high-energy nucleons

    Science.gov (United States)

    Cucinotta, Francis A.; Hajnal, Ferenc; Wilson, John W.

    1990-01-01

    The transport of nuclear fragmentation recoils produced by high-energy nucleons in the region of the bone-tissue interface is considered. Results for the different flux and absorbed dose for recoils produced by 1 GeV protons are presented in a bidirectional transport model. The energy deposition in marrow cavities is seen to be enhanced by recoils produced in bone. Approximate analytic formulae for absorbed dose near the interface region are also presented for a simplified range-energy model.

  1. The application of bone morphogenetic proteins to periodontal and peri-implant tissue regeneration: A literature review

    OpenAIRE

    Karuppanan P Sasikumar; Sugumari Elavarasu; Jayaprakash S Gadagi

    2012-01-01

    Progress in understanding the role of bone morphogenetic proteins (BMPs) in craniofacial and tooth development and the demonstration of stem cells in periodontal ligament have set the stage for periodontal regenerative therapy and tissue engineering. Furthermore, recent approval by the Food and Drug Administration of recombinant human BMPs for accelerating bone fusion in slow-healing fractures indicates that this protein family may prove useful in designing regenerative treatments in periodon...

  2. Integrin expression in stem cells from bone marrow and adipose tissue during chondrogenic differentiation.

    Science.gov (United States)

    Goessler, Ulrich Reinhart; Bugert, Peter; Bieback, Karen; Stern-Straeter, Jens; Bran, Gregor; Hörmann, Karl; Riedel, Frank

    2008-03-01

    The use of adult mesenchymal stem cells (MSC) in cartilage tissue engineering offers new perspectives in the generation of transplants for reconstructive surgery. The extracelular matrix (ECM) plays a key role in modulating the function and phenotype of the embedded cells and contains the integrins as adhesion receptors mediating cell-cell and cell-matrix interactions. In our study, characteristic changes in integrin expression during the course of chondrogenic differentiation of MSC from bone marrow and adipose tissue were compared. MSC were isolated from bone marrow biopsies and adipose tissue. During cell culture, chondrogenic differentiation was performed. The expression of integrins and their signaling components were analysed with microarray and immunohistochemistry in freshly isolated MSC and after chondrogenic differentiation. The fibronectin receptor (integrin alpha5beta1) was expressed by undifferentiated MSC, and expression rose during chondrogenic differentiation in both types of MSC. The components of the vitronectin/osteopontin receptors (alphavbeta5) were not expressed by freshly isolated MSC, and expression rose with ongoing differentiation. Receptors for the collagens (alpha1beta1, alpha2beta1, alpha3beta1) were weakly expressed by undifferentiated MSC and were activated during differentiation. Intracellular signaling components integrin-linked kinase (ILK) and CD47 showed increased expression with ongoing differentiation. For all integrins, no significant differences were be found in the 2 types of MSC. Integrin-mediated signaling appeared to play an important role in the generation and maintenance of the chondrocytic phenotype during chondrogenic differentiation. Particularly, the receptors for fibronectin, vitronectin, osteopontin and the collagens may be involved in the generation of the ECM. Intracellularly, their signals might be transduced by ILK and CD47. To fully harness the potential of these cells, future studies should be directed to

  3. Human Dental Pulp-Derived Cells Produce Bone-Like Tissue and Exhibit Bone Cell-Like Responsiveness to Mechanical Loading

    DEFF Research Database (Denmark)

    Kraft, David Christian Evar; Melsen, Birte; Bindslev, Dorthe Arenholt

    2010-01-01

    Recent studies have shown that dental pulp cells possess stem cell like potential and thus may be potential candidates for tissue engineering purposes particularly in the oro-facial region. Successful tissue engineering ideally requires that newly formed bone adapts its mass, shape, and trabecular...... and characterize cell lines from human 3rd molar dental pulp tissue to determine whether human dental pulp-derived cells (DPCs) are osteogenic and responsive to mechanical loading by pulsating fluid flow (PFF) in vitro. Methods: Human DPCs used for this study were characterized by measuring proliferation...

  4. Platelet-derived growth factor and spatiotemporal cues induce development of vascularized bone tissue by adipose-derived stem cells.

    Science.gov (United States)

    Hutton, Daphne L; Moore, Erika M; Gimble, Jeffrey M; Grayson, Warren L

    2013-09-01

    Vasculature is essential to the functional integration of a tissue-engineered bone graft to enable sufficient nutrient delivery and viability after implantation. Native bone and vasculature develop through intimately coupled, tightly regulated spatiotemporal cell-cell signaling. The complexity of these developmental processes has been a challenge for tissue engineers to recapitulate, resulting in poor codevelopment of both bone and vasculature within a unified graft. To address this, we cultured adipose-derived stromal/stem cells (ASCs), a clinically relevant, single cell source that has been previously investigated for its ability to give rise to vascularized bone grafts, and studied the effects of initial spatial organization of cells, the temporal addition of growth factors, and the presence of exogenous platelet-derived growth factor-BB (PDGF-BB) on the codevelopment of bone and vascular tissue structures. Human ASCs were aggregated into multicellular spheroids via the hanging drop method before encapsulation and subsequent outgrowth in fibrin gels. Cellular aggregation substantially increased vascular network density, interconnectivity, and pericyte coverage compared to monodispersed cultures. To form robust vessel networks, it was essential to culture ASCs in a purely vasculogenic medium for at least 8 days before the addition of osteogenic cues. Physiologically relevant concentrations of exogenous PDGF-BB (20 ng/mL) substantially enhanced both vascular network stability and osteogenic differentiation. Comparisons with the bone morphogenetic protein-2, another pro-osteogenic and proangiogenic growth factor, indicated that this potential to couple the formation of both lineages might be unique to PDGF-BB. Furthermore, the resulting tissue structure demonstrated the close association of mineral deposits with pre-existing vascular structures that have been described for developing tissues. This combination of a single cell source with a potent induction factor

  5. 骨组织工程支架的研究进展%Research Progress of Bone Tissue Engineering Scaffolds

    Institute of Scientific and Technical Information of China (English)

    袁景(综述); 甄平(审校)

    2015-01-01

    骨组织工程支架最初用于骨组织的结构性修复,现在负载生物活性物质用于骨诱导和血管形成,促进骨组织生长、修复骨缺损,并呈递生物活性物质。骨组织工程支架负载生物分子或药物等促进成骨和血管生成特性逐渐成为现在研究的热点。在对骨组织工程支架的构建方面,3 D打印技术以设计方便,构建不需要模具,可以轻易制备结构复杂、孔隙均匀、几何形态各异的骨组织工程支架,被业内广泛认可。%Bone tissue engineering scaffolds are originally used for structural restoration for bone tissue , and now with the load of biologically active substances they are used for bone induction and angiogenesis to promote bone tissue growth.The bone tissue engineering scaffolds loaded with biological molecules or drugs to promote bone formation and angiogenesis properties has become the research focus in the field.3D printing technology is widely accepted in the bone tissue engineering field due to the advantages of easy design ,easy making of various scaffolds of complex structure,uniform pores and different geometric shapes without molds.

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

    Science.gov (United States)

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

    2017-03-13

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

  7. Wrapped omentum with periosteum concurrent with adipose derived adult stem cells for bone tissue engineering in dog model.

    Science.gov (United States)

    Sadegh, Amin Bigham; Basiri, Ehsan; Oryan, Ahmad; Mirshokraei, Pezhman

    2014-03-01

    Adipose derived adult stem cells (ASCs) are multipotent cells that are able to differentiate into osteoblasts in presence of certain factors. The histological characteristics of periosteum makes it a specific tissue with a unique capacity to be engineered. Higher flexibility of the greater omentum is useful for reconstructive surgery. These criteria make it suitable for tissue engineering. The present study was designed to evaluate bone tissue engineering with periosteal free graft concurrent with ASCs and pedicle omentum in dog model. Twelve young female indigenous dogs were used in this experiment. In omental group (n = 4), end of omentum was wrapped by periosteum of the radial bone in abdomen of each dog. In omental-autogenously ASCs group (n = 4), 1 ml of ASCs was injected into the wrapped omentum with periosteum while in omental-allogenously ASCs group (n = 4), 1 ml of allogenous ASCs was injected. Lateral view radiographs were taken from the abdominal cavity postoperatively at the 2nd, 4th, 6th and 8th weeks post-surgery. Eight weeks after operation the dogs were re-anesthetized and the wrapped omenum by periosteum in all groups was found and removed for histopathological evaluation. Our results showed that omentum-periosteum, omental-periosteum-autogenous ASCs and omental-periosteum-allogenous ASCs groups demonstrated bone tissue formation in the abdominal cavity in dog model. The radiological, macroscopical and histological findings of the present study by the end of 8 weeks post-surgery indicate bone tissue engineering in all three groups in an equal level. The present study has shown that the wrapped omentum with periosteum concurrent with ASCs (autogenous or allogenous ASCs) lead to a favorable bone tissue formation. We suggested that it may be useful when pedicle graft omentum used concurrent with periosteum in the bone defect reconstruction, and this phenomenon should be studied in future.

  8. Collecting and Storing Tissue, Blood, and Bone Marrow Samples From Patients With Rhabdomyosarcoma or Other Soft Tissue Sarcoma

    Science.gov (United States)

    2016-09-23

    Adult Rhabdomyosarcoma; Childhood Desmoplastic Small Round Cell Tumor; Chordoma; Desmoid Tumor; Metastatic Childhood Soft Tissue Sarcoma; Nonmetastatic Childhood Soft Tissue Sarcoma; Previously Treated Childhood Rhabdomyosarcoma; Previously Untreated Childhood Rhabdomyosarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Stage I Adult Soft Tissue Sarcoma; Stage II Adult Soft Tissue Sarcoma; Stage III Adult Soft Tissue Sarcoma; Stage IV Adult Soft Tissue Sarcoma

  9. The ectopic study of tissue-engineered bone with hBMP-4 gene modified bone marrow stromal cells in rabbits

    Institute of Scientific and Technical Information of China (English)

    JIANG Xin-quan; CHEN Jian-guo; Sébastien Gittens; CHEN Chuan-jun; ZHANG Xiu-li; ZHANG Zhi-yuan

    2005-01-01

    Background Tissue-engineering techniques combined with gene therapy have been recently reported to improve osteogenesis. In this study, tissue-engineered bone constructed by human Bone Morphogenetic Protein 4 (hBMP-4) gene-modified bone marrow stromal cells (bMSCs) was explored in an ectopic bone formation model in rabbits.Methods A pEGFP-hBMP-4 mammalian plasmid (EGFP: Enhanced Green Fluorescent Protein) was constructed by subcloning techniques. bMSCs obtained from rabbits were cultured and transfected with either pEGFP-hBMP-4, pEGFP or left uninfected in vitro. Transfer efficiency was detected through the expression of EGFP. Transcription of the target gene was detected by RT-PCR. Alkaline phosphatase (ALP) and Von Kossa tests were also conducted to explore the phenotypes of osteoblasts. The autologous bMSCs of the 3 groups were then combined with Natural Non-organic Bone (NNB), a porous hydroxyapatite implant with a dimension of 6 mm×6 mm×3 mm, at a concentration of 5×107 cells/ml. They were subsequently implanted into 6 rabbits subcutaneously using NNB alone as a blank control (6 implants per group). Four weeks after surgery, the implants were evaluated with histological staining and computerized analysis of new bone formation.Results pEGFP-hBMP-4 expression plasmid was constructed. Under optimal conditions, gene transfer efficiency reached more than 30%. Target gene transfer could strengthen the transcription of BMP-4, and increase the expression of ALP as well as the number of calcium nodules. In the ectopic animal model, NNB alone could not induce new bone formation. The new bone area formed in the bMSCs group was (17.2±7.1)%, and pEGFP group was (14.7±6.1)%, while pEGFP-hBMP-4 group was (29.5±8.2)%, which was the highest among the groups (F=7.295, P<0.01). Conclusions The mammalian hBMP-4 expression plasmid was successfully constructed and a comparatively high transfer efficiency was achieved. The gene transfer technique enhanced the expression of BMP

  10. Adipose, bone and muscle tissues as new endocrine organs: role of reciprocal regulation for osteoporosis and obesity development.

    Science.gov (United States)

    Migliaccio, Silvia; Greco, Emanuela A; Wannenes, Francesca; Donini, Lorenzo M; Lenzi, Andrea

    2014-01-01

    The belief that obesity is protective against osteoporosis has recently been revised. In fact, the latest epidemiologic and clinical studies show that a high level of fat mass, but also reduced muscle mass, might be a risk factor for osteoporosis and fragility fractures. Furthermore, increasing evidence seems to indicate that different components such as myokines, adipokines and growth factors, released by both fat and muscle tissues, could play a key role in the regulation of skeletal health and in low bone mineral density and, thus, in osteoporosis development. This review considers old and recent data in the literature to further evaluate the relationship between fat, bone and muscle tissue.

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

    DEFF Research Database (Denmark)

    Kirkeby, S

    1981-01-01

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

  12. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  13. An ectopic study of tissue-engineered bone with Nell-1 gene modified rat bone marrow stromal cells in nude mice

    Institute of Scientific and Technical Information of China (English)

    HU Jing-zhou; ZHANG Zhi-yuan; ZHAO Jun; ZHANG Xiu-li; LIU Gen-tao; JIANG Xin-quan

    2009-01-01

    Background Tissue engineering techniques combined with gene therapy have been recently used to improve osteogenesis. NEL-like molecule-1 (Nell-1), a novel growth factor, has been reported to have specificity for osteochondral lineage. The study assessed the osteogenic differentiation of rat bone marrow stromal cells (bMSCs) after Nell-1 gene modification and examined its ectopic bone formation ability in a nude mice model with tissue engineering technique.Methods bMSCs obtained from Fischer 344 rats were transduced with either AdNell-1 (Nell-1 group) or Ad-β-galactosidase (AdLacZ, LacZ group) or left untransduced (untransduced group). The expression of Nell-1 protein was determined by Western blotting and transfer efficiency was assessed, mRNA expressions of osteopontin (OP), bone sialoprotein (BSP) and osteocalcin (OC) were assessed by real-time PCR 0, 3, 7, 14, and 21 days after gene transfer. Alkaline phosphatase (ALP) activity was measured and von Kossa test was also conducted. Finally, with a tissue engineering technique, gene transduced bMSCs, combining with β-tricalcium phosphate (β-TCP) at a concentration of 2×107 cells/ml, were implanted at subcutaneous sites on the back of nude mice. Four weeks after surgery, the implants were evaluated with histological staining and computerized analysis of new bone formation.Results Under current transduction conditions, gene transfer efficiency reached (57.9±6.8)%. Nell-1 protein was detected in Nell-1 group but not in untransduced group and LacZ group. Induced by Nell-1, BSPand OPexpression were increased at intermediate stage and OC expression was increased at later stage. ALP activity and the number of calcium nodules were highest in Nell-1 group. Four weeks after implanted into nude mice subcutaneously, the percentage of new bone area in Nell-1 group was (18.1±5.0)%, significantly higher than those of untransduced group (11.3±3.2)% and LacZ group (12.3±3.1)% (P<0.05).Conclusions This study has demonstrated

  14. Long-term stability of peri-implant tissues after bone or soft tissue augmentation. Effect of zirconia or titanium abutments on peri-implant soft tissues. Summary and consensus statements. The 4th EAO Consensus Conference 2015

    NARCIS (Netherlands)

    Sicilia, Alberto; Quirynen, Marc; Fontolliet, Alain; Francisco, Helena; Friedman, Anton; Linkevicius, Tomas; Lutz, Rainer; Meijer, Henny J.; Rompen, Eric; Rotundo, Roberto; Schwarz, Frank; Simion, Massimo; Teughels, Wim; Wennerberg, Ann; Zuhr, Otto

    2015-01-01

    Introduction: Several surgical techniques and prosthetic devices have been developed in the last decades, aiming to improve aesthetic, hygienic and functional outcomes that may affect the peri-implant tissues, such as procedures of bone and soft tissue augmentation and the use of custom-made abutmen

  15. Enhanced Bone Tissue Regeneration by Porous Gelatin Composites Loaded with the Chinese Herbal Decoction Danggui Buxue Tang.

    Directory of Open Access Journals (Sweden)

    Wen-Ling Wang

    Full Text Available Danggui Buxue Tang (DBT is a traditional Chinese herbal decoction containing Radix Astragali and Radix Angelicae sinensis. Pharmacological results indicate that DBT can stimulate bone cell proliferation and differentiation. The aim of the study was to investigate the efficacy of adding DBT to bone substitutes on bone regeneration following bone injury. DBT was incorporated into porous composites (GGT made from genipin-crosslinked gelatin and β-triclacium phosphates as bone substitutes (GGTDBT. The biological response of mouse calvarial bone to these composites was evaluated by in vivo imaging systems (IVIS, micro-computed tomography (micro-CT, and histology analysis. IVIS images revealed a stronger fluorescent signal in GGTDBT-treated defect than in GGT-treated defect at 8 weeks after implantation. Micro-CT analysis demonstrated that the level of repair from week 4 to 8 increased from 42.1% to 71.2% at the sites treated with GGTDBT, while that increased from 33.2% to 54.1% at GGT-treated sites. These findings suggest that the GGTDBT stimulates the innate regenerative capacity of bone, supporting their use in bone tissue regeneration.

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

    Science.gov (United States)

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

    2015-01-01

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

  17. Engineered polycaprolactone-magnesium hybrid biodegradable porous scaffold for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    Hoi Man Wong; Paul K. Chu; Frankie K.L. Leung; Kenneth M.C. Cheung; Keith D.K. Luk; Kelvin W.K. Yeung

    2014-01-01

    In this paper, we describe the fabrication of a new biodegradable porous scaffold composed of polycaprolactone (PCL) and magnesium (Mg) micro-particles. The compressive modulus of PCL porous scaffold was increased to at least 150%by incorporating 29%Mg particles with the porosity of 74%using Micro-CT analysis. Surprisingly, the compressive modulus of this scaffold was further increased to at least 236%when the silane-coupled Mg particles were added. In terms of cell viability, the scaffold modified with Mg particles significantly convinced the attachment and growth of osteoblasts as compared with the pure PCL scaffold. In addition, the hybrid scaffold was able to attract the formation of apatite layer over its surface after 7 days of immersion in normal culture medium, whereas it was not observed on the pure PCL scaffold. This in vitro result indicated the enhanced bioactivity of the modified scaffold. Moreover, enhanced bone forming ability was also observed in the rat model after 3 months of implantation. Though bony in-growth was found in all the implanted scaffolds. High volume of new bone formation could be found in the Mg/PCL hybrid scaffolds when compared to the pure PCL scaffold. Both pure PCL and Mg/PCL hybrid scaffolds were degraded after 3 months. However, no tissue inflammation was observed. In conclusion, these promising results suggested that the incorporation of Mg micro-particles into PCL porous scaffold could significantly enhance its mechanical and biological properties. This modified porous bio-scaffold may potentially apply in the surgical management of large bone defect fixation.

  18. Bone tissue incorporates in vitro gallium with a local structure similar to gallium-doped brushite.

    Science.gov (United States)

    Korbas, M; Rokita, E; Meyer-Klaucke, W; Ryczek, J

    2004-01-01

    During mineral growth in rat bone-marrow stromal cell cultures, gallium follows calcium pathways. The dominant phase of the cell culture mineral constitutes the poorly crystalline hydroxyapatite (HAP). This model system mimics bone mineralization in vivo. The structural characterization of the Ga environment was performed by X-ray absorption spectroscopy at the Ga K-edge. These data were compared with Ga-doped synthetic compounds (poorly crystalline hydroxyapatite, amorphous calcium phosphate and brushite) and with strontium-treated bone tissue, obtained from the same culture model. It was found that Sr(2+) substitutes for Ca(2+) in the HAP crystal lattice. In contrast, the replacement by Ga(3+) yielded a much more disordered local environment of the probe atom in all investigated cell culture samples. The coordination of Ga ions in the cell culture minerals was similar to that of Ga(3+), substituted for Ca(2+), in the Ga-doped synthetic brushite (Ga-DCPD). The Ga atoms in the Ga-DCPD were coordinated by four oxygen atoms (1.90 A) of the four phosphate groups and two oxygen atoms at 2.02 A. Interestingly, the local environment of Ga in the cell culture minerals was not dependent on the onset of Ga treatment, the Ga concentration in the medium or the age of the mineral. Thus, it was concluded that Ga ions were incorporated into the precursor phase to the HAP mineral. Substitution for Ca(2+ )with Ga(3+) distorted locally this brushite-like environment, which prevented the transformation of the initially deposited phase into the poorly crystalline HAP.

  19. Three-dimensional printing of porous ceramic scaffolds for bone tissue engineering.

    Science.gov (United States)

    Seitz, Hermann; Rieder, Wolfgang; Irsen, Stephan; Leukers, Barbara; Tille, Carsten

    2005-08-01

    This article reports a new process chain for custom-made three-dimensional (3D) porous ceramic scaffolds for bone replacement with fully interconnected channel network for the repair of osseous defects from trauma or disease. Rapid prototyping and especially 3D printing is well suited to generate complex-shaped porous ceramic matrices directly from powder materials. Anatomical information obtained from a patient can be used to design the implant for a target defect. In the 3D printing technique, a box filled with ceramic powder is printed with a polymer-based binder solution layer by layer. Powder is bonded in wetted regions. Unglued powder can be removed and a ceramic green body remains. We use a modified hydroxyapatite (HA) powder for the fabrication of 3D printed scaffolds due to the safety of HA as biocompatible implantable material and efficacy for bone regeneration. The printed ceramic green bodies are consolidated at a temperature of 1250 degrees C in a high temperature furnace in ambient air. The polymeric binder is pyrolysed during sintering. The resulting scaffolds can be used in tissue engineering of bone implants using patient-derived cells that are seeded onto the scaffolds. This article describes the process chain, beginning from data preparation to 3D printing tests and finally sintering of the scaffold. Prototypes were successfully manufactured and characterized. It was demonstrated that it is possible to manufacture parts with inner channels with a dimension down to 450 microm and wall structures with a thickness down to 330 microm. The mechanical strength of dense test parts is up to 22 MPa.

  20. Exposure to pastures fertilised with sewage sludge disrupts bone tissue homeostasis in sheep

    Energy Technology Data Exchange (ETDEWEB)

    Lind, P. Monica [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden)], E-mail: Monica.Lind@ki.se; Gustafsson, Magnus [Department of Environmental Toxicology, Uppsala University, Uppsala (Sweden); Hermsen, Sanne A.B. [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Larsson, Sune [Department of Orthopaedics, University of Uppsala, Uppsala (Sweden); Kyle, Carol E. [Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom); Orberg, Jan [Department of Environmental Toxicology, Uppsala University, Uppsala (Sweden); Rhind, Stewart M. [Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom)

    2009-03-15

    The femurs of male and female sheep (Ovis aries), aged 18 months, bred on pastures fertilized twice annually with sewage sludge (2.25 tonnes dry matter/ha; Treated; T)) or on pastures treated with inorganic fertilizer (Control; C) were studied, using peripheral Quantitative Computed Tomography (pQCT) and the three-point bending test. Males were maintained on the respective treatments from conception to weaning and then maintained on control pastures while the females were maintained on the respective treatments until slaughter. T rams exhibited increased total bone mineral density (BMD) at the metaphyseal part of femur (+ 10.5%, p < 0.01) compared with C rams but had a reduced total cross sectional area (CSA, - 11.5%, p < 0.001), trabecular CSA (- 17.1%, p < 0.01) and periosteal circumference (- 5.7%, p < 0.001). In the mid-diaphyseal part, T rams had an increased total BMD (+ 13.8%, p < 0.0001) and stiffness (+ 6.4%, p < 0.01) but reduced total CSA (- 12.1%, p < 0.0001) and marrow cavity (- 25.8%, p < 0.0001), relative to C rams. In ewes although pQCT analysis of neither the metaphyseal nor the mid-diaphyseal part of the female femur bones showed any significant differences with treatment, the biomechanical method revealed a reduction in load at failure (- 17.3%, p < 0.01) and stiffness (- 10.7%, p < 0.05) amongst T ewes. It is concluded that exposure to pollutants present in sewage sludge can perturb bone tissue homeostasis in sheep, but particularly in males.

  1. Engineered polycaprolactone–magnesium hybrid biodegradable porous scaffold for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Hoi Man Wong

    2014-10-01

    Full Text Available In this paper, we describe the fabrication of a new biodegradable porous scaffold composed of polycaprolactone (PCL and magnesium (Mg micro-particles. The compressive modulus of PCL porous scaffold was increased to at least 150% by incorporating 29% Mg particles with the porosity of 74% using Micro-CT analysis. Surprisingly, the compressive modulus of this scaffold was further increased to at least 236% when the silane-coupled Mg particles were added. In terms of cell viability, the scaffold modified with Mg particles significantly convinced the attachment and growth of osteoblasts as compared with the pure PCL scaffold. In addition, the hybrid scaffold was able to attract the formation of apatite layer over its surface after 7 days of immersion in normal culture medium, whereas it was not observed on the pure PCL scaffold. This in vitro result indicated the enhanced bioactivity of the modified scaffold. Moreover, enhanced bone forming ability was also observed in the rat model after 3 months of implantation. Though bony in-growth was found in all the implanted scaffolds. High volume of new bone formation could be found in the Mg/PCL hybrid scaffolds when compared to the pure PCL scaffold. Both pure PCL and Mg/PCL hybrid scaffolds were degraded after 3 months. However, no tissue inflammation was observed. In conclusion, these promising results suggested that the incorporation of Mg micro-particles into PCL porous scaffold could significantly enhance its mechanical and biological properties. This modified porous bio-scaffold may potentially apply in the surgical management of large bone defect fixation.

  2. Evaluating differential nuclear DNA yield rates and osteocyte numbers among human bone tissue types: A synchrotron radiation micro-CT approach.

    Science.gov (United States)

    Andronowski, Janna M; Mundorff, Amy Z; Pratt, Isaac V; Davoren, Jon M; Cooper, David M L

    2017-05-01

    Molecular human identification has conventionally focused on DNA sampling from dense, weight-bearing cortical bone tissue, typically from femora or tibiae. A comparison of skeletal elements from three contemporary individuals demonstrated that elements with high quantities of cancellous bone yielded nuclear DNA at the highest rates, suggesting that preferentially sampling cortical bone may be suboptimal (Mundorff & Davoren, 2014). Despite these findings, the reason for the differential DNA yields between cortical and cancellous bone tissues remains unknown. The primary goal of this work is to ascertain whether differences in bone microstructure can be used to explain differential nuclear DNA yield among bone tissue types observed by Mundorff and Davoren (2014), with a focus on osteocytes and the three-dimensional (3D) quantification of their associated lacunae. Osteocytes and other bone cells are recognized to house DNA in bone tissue, thus examining the density of their lacunae may explain why nuclear DNA yield rates differ among bone tissue types. Lacunae were visualized and quantified using synchrotron radiation-based micro-Computed Tomographic imaging (SR micro-CT). Volumes of interest (VOIs) from cortical and cancellous bone tissues (n=129) were comparatively analyzed from the three skeletons sampled for Mundorff and Davoren's (2014) study. Analyses tested the primary hypothesis that the abundance and density of osteocytes (inferred from their lacunar spaces) vary between cortical and cancellous bone tissue types. Results demonstrated that osteocyte lacunar abundance and density vary between cortical and cancellous bone tissue types, with cortical bone VOIs containing a higher lacunar abundance and density. We found that the osteocyte lacunar density values are independent of nuclear DNA yield, suggesting an alternative explanation for the higher nuclear DNA yields from bones with greater quantities of cancellous bone tissue. The use of SR micro-CT allowed for

  3. Levamisole-induced necrosis of skin, soft tissue, and bone: case report and review of literature.

    Science.gov (United States)

    Ching, Jessica A; Smith, David J

    2012-01-01

    This represents the largest case of skin necrosis related to levamisole, a common cocaine contaminant, requiring closure with skin grafts, and is the only case resulting in nasal amputation, central upper lip excision, extremity bone necrosis, and above knee amputation. The case report is followed by a review of the literature. Unique considerations for the full-thickness necrosis induced by levamisole vasculitis are highlighted, including antibody level monitoring, need for multiple excisions, timing of skin grafting, and potential for soft tissue and bone necrosis as well. A 54-year-old man presented to an outside facility with fever, generalized weakness, and agranulocytosis, with a history of cocaine use 3 weeks before. After admission, he developed generalized violaceous lesions and an elevated p-antineutrophilic cytoplasmic antibody and was diagnosed with disseminated vasculitis and agranulocytosis secondary to levamisole-contaminated cocaine exposure. On transfer to the authors' facility, 52% TBSA was involved with violaceous, nonblanching lesions, which progressed to full-thickness necrosis. Local wound care continued until necrotic areas fully demarcated and progressive necrosis stabilized, and skin grafting for closure was not performed until antibody levels normalized. Current treatment of levamisole-induced skin rash or necrosis focuses on discontinuation of levamisole. As demonstrated by this case, extensive necrosis secondary to levamisole-induced vasculitis can be successfully treated with multiple excisions until necrosis stabilizes, and then, split-thickness autografts may be applied. In areas with poor vascular supply or areas with poor functional prognosis, amputation may ultimately be required.

  4. Preparation and Evaluation of Gelatin-Chitosan-Nanobioglass 3D Porous Scaffold for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Kanchan Maji

    2016-01-01

    Full Text Available The aim of the present study was to prepare and characterize bioglass-natural biopolymer based composite scaffold and evaluate its bone regeneration ability. Bioactive glass nanoparticles (58S in the size range of 20–30 nm were synthesized using sol-gel method. Porous scaffolds with varying bioglass composition from 10 to 30 wt% in chitosan, gelatin matrix were fabricated using the method of freeze drying of its slurry at 40 wt% solids loading. Samples were cross-linked with glutaraldehyde to obtain interconnected porous 3D microstructure with improved mechanical strength. The prepared scaffolds exhibited >80% porosity with a mean pore size range between 100 and 300 microns. Scaffold containing 30 wt% bioglass (GCB 30 showed a maximum compressive strength of 2.2±0.1 MPa. Swelling and degradation studies showed that the scaffold had excellent properties of hydrophilicity and biodegradability. GCB 30 scaffold was shown to be noncytotoxic and supported mesenchymal stem cell attachment, proliferation, and differentiation as indicated by MTT assay and RUNX-2 expression. Higher cellular activity was observed in GCB 30 scaffold as compared to GCB 0 scaffold suggesting the fact that 58S bioglass nanoparticles addition into the scaffold promoted better cell adhesion, proliferation, and differentiation. Thus, the study showed that the developed composite scaffolds are potential candidates for regenerating damaged bone tissue.

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

  6. Fabrication of Negative Charged Poly (Ethylene glycol)-diacrylate Hydrogel as a Bone Tissue Engineering scaffold

    Institute of Scientific and Technical Information of China (English)

    WANG Ya-qi; LIU Jie; TAN Fei; XIE Wei

    2016-01-01

    Objective To improve the cell attachment of PEGDA hydrogel, the SMAS small molecule was used to modify the PEGDA hydrogel. The charged hydrogel would show improved cell attachment and enhanced protein adsorption caused by enhancement of electrostatic adsorption.Method In this study, a series of charged hydrogels were produced by adding different concentrations of charged small molecule monomer into the PEGDA solution. Then, we investigate the physicochemical and biological characteristics of charged hydrogels, including FTIR, swelling ratio, contact angle, cell attachment.Result The results indicate that the charged monomer had been successfully incorporated into PEGDA hydrogel. Meanwhile, the protein adsorption of the hydrogel increased with increasing concentration of charge modification. Moreover, compared to PEGDA hydrogel, the cell attachment significantly improved on the charged hydrogel.Conclusion The charged hydrogel would be a promising scaffold candidate for bone tissue engineering.

  7. Indian data on bone and soft tissue sarcomas: A summary of published study results

    Directory of Open Access Journals (Sweden)

    Anant Ramaswamy

    2016-01-01

    Full Text Available Bone sarcomas are rare tumors, approximating 0.2% of all cancers, with osteosarcoma (OGS, chondrosarcoma, and Ewing sarcoma being the most common cancers in this subset. The formation of disease management groups/clinics focused on sarcomas has resulted in better understanding and management of these uncommon tumors. Multiple large-scale retrospective data from Tata Memorial Hospital (TMH and All India Institute of Medical Sciences have reported outcomes comparable to Western data in the field of OGS and Ewing sarcoma, with interesting prognostic factors identified for further evaluation. Soft tissue sarcomas are a rare heterogeneous group of tumors, more than 50 different tumor entities. The common subtypes identified in India include Ewing sarcoma and synovial sarcoma. Valuable work regarding brachytherapy has been done by radiation oncologists from the TMH, especially in pediatric patients.

  8. Hybrid scaffolds based on PLGA and silk for bone tissue engineering.

    Science.gov (United States)

    Sheikh, Faheem A; Ju, Hyung Woo; Moon, Bo Mi; Lee, Ok Joo; Kim, Jung-Ho; Park, Hyun Jung; Kim, Dong Wook; Kim, Dong-Kyu; Jang, Ji Eun; Khang, Gilson; Park, Chan Hum

    2016-03-01

    Porous silk scaffolds, which are considered to be natural polymers, cannot be used alone because they have a long degradation rate, which makes it difficult for them to be replaced by the surrounding tissue. Scaffolds composed of synthetic polymers, such as PLGA, have a short degradation rate, lack hydrophilicity and their release of toxic by-products makes them difficult to use. The present investigations aimed to study hybrid scaffolds fabricated from PLGA, silk and hydroxyapatite nanoparticles (Hap NPs) for optimized bone tissue engineering. The results from variable-pressure field emission scanning electron microscopy (VP-FE-SEM), equipped with EDS, confirmed that the fabricated scaffolds had a porous architecture, and the location of each component present in the scaffolds was examined. Contact angle measurements confirmed that the introduction of silk and HAp NPs helped to change the hydrophobic nature of PLGA to hydrophilic, which is the main constraint for PLGA used as a biomaterial. Thermo-gravimetric analysis (TGA) and FT-IR spectroscopy confirmed thermal decomposition and different vibrations caused in functional groups of compounds used to fabricate the scaffolds, which reflected improvement in their mechanical properties. After culturing osteoblasts for 1, 7 and 14 days in the presence of scaffolds, their viability was checked by MTT assay. The fluorescent microscopy results revealed that the introduction of silk and HAp NPs had a favourable impact on the infiltration of osteoblasts. In vivo experiments were conducted by implanting scaffolds in rat calvariae for 4 weeks. Histological examinations and micro-CT scans from these experiments revealed beneficial attributes offered by silk fibroin and HAp NPs to PLGA-based scaffolds for bone induction.

  9. Biological performance of titania containing phosphate-based glasses for bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Abou Neel, Ensanya Ali, E-mail: eabouneel@kau.edu.sa [Division of Biomaterials, Conservative Dental Sciences Department, King Abdulaziz University, Jeddah (Saudi Arabia); Biomaterials Department, Faculty of Dentistry, Tanta University, Tanta (Egypt); Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray' s Inn Road, London WC1X 8LD (United Kingdom); Chrzanowski, Wojciech [The University of Sydney, Faculty of Pharmacy, Pharmacy and Bank Building, NSW2006 (Australia); Department of Nanobiomedical Science and BK21 Plus NBM Global Reserch Center for Regenerative Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); Knowles, Jonathan Campbell, E-mail: j.knowles@ucl.ac.uk [Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray' s Inn Road, London WC1X 8LD (United Kingdom); Department of Nanobiomedical Science and BK21 Plus NBM Global Reserch Center for Regenerative Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of)

    2014-02-01

    The interplay between glass chemistry, structure, degradation kinetics, and biological activity provides flexibility for the development of scaffolds with highly specific cellular response. The aim of this study was therefore to investigate the role of titania inclusion into the phosphate-based glass on its ability to stimulate osteoblast-like human osteosarcoma (HOS) cells to adhere, proliferate and differentiate. In depth morphological and biochemical characterisation was performed on HOS cells cultured on the surface of glass discs. Cell proliferation was also studied in the presence of the glass extract. Cell differentiation, through osteoblast phenotype genes, alkaline phosphatase (ALP) activity and osteocalcin production, was carried out using normal or osteogenic media. Both Thermanox® and titania free glass were used as controls. The data demonstrated that titania inclusion provides desired cytocompatible surface that supported initial cell attachment, sustained viability, and increased cell proliferation similar or significantly higher than Thermanox®. The modified glasses regulated osteoblastic cell differentiation as detected by osteoblast phenotype gene transcription and upregulated ALP and osteocalcin expression. Using osteogenic media had no significant effect on ALP activity and osteocalcin expression. Therefore, titania modified phosphate glasses may have future use as bone tissue engineering scaffolds. - Highlights: • This study investigated the role of titania on the biological response of phosphate glasses. • Incorporation of titania improved HOS cell attachment, viability and proliferation. • Titania modified glasses regulated osteoblastic cell differentiation. • Using osteogenic media had no significant effect on cell differentiation. • Titania modified glasses may have future use as bone tissue engineering scaffolds.

  10. Hybrid use of combined and sequential delivery of growth factors and ultrasound stimulation in porous multilayer composite scaffolds to promote both vascularization and bone formation in bone tissue engineering.

    Science.gov (United States)

    Yan, Haoran; Liu, Xia; Zhu, Minghua; Luo, Guilin; Sun, Tao; Peng, Qiang; Zeng, Yi; Chen, Taijun; Wang, Yingying; Liu, Keliang; Feng, Bo; Weng, Jie; Wang, Jianxin

    2016-01-01

    In this study, a multilayer coating technology would be adopted to prepare a porous composite scaffold and the growth factor release and ultrasound techniques were introduced into bone tissue engineering to finally solve the problems of vascularization and bone formation in the scaffold whilst the designed multilayer composite with gradient degradation characteristics in the space was used to match the new bone growth process better. The results of animal experiments showed that the use of low intensity pulsed ultrasound (LIPUS) combined with growth factors demonstrated excellent capabilities and advantages in both vascularization and new bone formation in bone tissue engineering. The degradation of the used scaffold materials could match new bone formation very well. The results also showed that only RGD-promoted cell adhesion was insufficient to satisfy the needs of new bone formation while growth factors and LIPUS stimulation were the key factors in new bone formation.

  11. Cartilage tissue engineering of nasal septal chondrocyte-macroaggregates in human demineralized bone matrix.

    Science.gov (United States)

    Liese, Juliane; Marzahn, Ulrike; El Sayed, Karym; Pruss, Axel; Haisch, Andreas; Stoelzel, Katharina

    2013-06-01

    Tissue Engineering is an important method for generating cartilage tissue with isolated autologous cells and the support of biomaterials. In contrast to various gel-like biomaterials, human demineralized bone matrix (DBM) guarantees some biomechanical stability for an application in biomechanically loaded regions. The present study combined for the first time the method of seeding chondrocyte-macroaggregates in DBM for the purpose of cartilage tissue engineering. After isolating human nasal chondrocytes and creating a three-dimensional macroaggregate arrangement, the DBM was cultivated in vitro with the macroaggregates. The interaction of the cells within the DBM was analyzed with respect to cell differentiation and the inhibitory effects of chondrocyte proliferation. In contrast to chondrocyte-macroaggregates in the cell-DBM constructs, morphologically modified cells expressing type I collagen dominated. The redifferentiation of chondrocytes, characterized by the expression of type II collagen, was only found in low amounts in the cell-DBM constructs. Furthermore, caspase 3, a marker for apoptosis, was detected in the chondrocyte-DBM constructs. In another experimental setting, the vitality of chondrocytes as related to culture time and the amount of DBM was analyzed with the BrdU assay. Higher amounts of DBM tended to result in significantly higher proliferation rates of the cells within the first 48 h. After 96 h, the vitality decreased in a dose-dependent fashion. In conclusion, this study provides the proof of concept of chondrocyte-macroaggregates with DBM as an interesting method for the tissue engineering of cartilage. The as-yet insufficient redifferentiation of the chondrocytes and the sporadic initiation of apoptosis will require further investigations.

  12. Efficient decellularization for tissue engineering of the tendon-bone interface with preservation of biomechanics

    Science.gov (United States)

    Foehr, Peter; Kuempel, Katharina; Wagner, Alexandra; Tuebel, Jutta; Deimling, Constantin V.; Burgkart, Rainer H.

    2017-01-01

    Interfaces between tendon/ligament and bone (“entheses”) are highly specialized tissues that allow for stress transfer between mechanically dissimilar materials. Entheses show very low regenerative capacity resulting in high incidences of failure after surgical repair. Tissue engineering is a promising approach to recover functionality of entheses. Here, we established a protocol to decellularize porcine entheses as scaffolds for enthesis tissue engineering. Chemical detergents as well as physical treatments were investigated with regard to their efficiency to decellularize 2 mm thick porcine Achilles tendon entheses. A two-phase approach was employed: study 1 investigated the effect of various concentrations of sodium dodecyl sulfate (SDS) and t-octylphenoxypolyethoxy-ethanol (Triton X-100) as decellularization agents. The most efficient combination of SDS and Triton was then carried forward into study 2, where different physical methods, including freeze-thaw cycles, ultrasound, perfusion, and hydrostatic washing were used to enhance the decellularization effect. Cell counts, DNA quantification, and histology showed that washing with 0.5% SDS + 1% Triton X-100 for 72 h at room temperature could remove ~ 98% cells from the interface. Further investigation of physical methods proved that washing under 200 mmHg hydrostatic pressure shortened the detergent exposing time from 72 h to 48 h. Biomechanical tensile testing showed that the biomechanical features of treated samples were preserved. Washing under 200 mmHg hydrostatic pressure with 0.5% SDS + 1% Triton X-100 for 48 h efficiently decellularized entheses with preservation of matrix structure and biomechanical features. This protocol can be used to efficiently decellularize entheses as scaffolds for tissue engineering. PMID:28170430

  13. Human bone marrow and adipose tissue mesenchymal stem cells: a user's guide.

    Science.gov (United States)

    Mosna, Federico; Sensebé, Luc; Krampera, Mauro

    2010-10-01

    Mesenchymal stem cells (MSCs) are adult stem cells that hold great promise in the field of regenerative medicine. They can be isolated from almost any tissue of the body and display, after expansion, very similar properties and minor differences, probably due to their microenvironment of origin. Expansion in vitro can be obtained in cytokine-free, serum-enriched media, as well as in serum-free, basic fibroblast growth factor-enriched media. A detailed immunophenotypic analysis is required to test the purity of the preparation, but no unique distinguishing marker has been described as yet. Functional assays, that is, differentiation studies in vitro, are needed to prove multilineage differentiation of expanded cells, and demonstration of pluripotency is necessary to identify most immature precursors. MSCs show powerful immunomodulative properties toward most of the cells of the immune system: this strengthens the theoretical rationale for their use also in an allogeneic setting across the major histocompatibility complex (MHC) immunological barriers. Systemic intravenous injection and local use have been tried: after systemic injection, MSCs show a high degree of chemotaxis based on pro-inflammatory cytokines, and localize at inflamed and neoplastic tissues; local regeneration has been improved using synthetic, as well as organic scaffolds. On the other hand, inadequate heterotopic in vivo differentiation and neoplastic transformation are potential risks of this form of cell therapy, even if evidence of this sort has been collected only from studies in mice, and generally after prolonged in vitro expansion. This review tries to provide a detailed technical overview of the methods used for human bone-marrow (BM)-derived and adipose-tissue (AT)-derived MSC isolation, in vitro expansion, and characterization for tissue repair. We chose to use BM-MSCs as a model to describe techniques that have been used for MSC isolation and expansion from very different sources, and

  14. Stereomicroscopic evaluation of the joint cartilage and bone tissue in osteoporosis

    Science.gov (United States)

    Vasile, Liliana; Torok, Rodica; Deleanu, Bogdan; Marchese, Cristian; Valeanu, Adina; Bodea, Rodica

    2012-06-01

    Aim of the study. Assessment by stereomicroscopy of the severity of lesions in osteoporotic bone at both sexes and to correlate micro-and macro-bone fracture due to low bone density values with the disease evolution. Material and method: The study material consists of fragments of bone from the femoral head, vertebral bone, costal and iliac crest biopsy obtained from patients aged over 70 years, female and male, treated in the County Hospital of Timisoara, Department of Orthopedics. For the purpose of studying the samples in stereomicroscopy and trough polarized light it has been used the Olympus Microscope SZ ×7 and an Olympus camera with 2,5 × digital zoom and a 3× optical zoom in the Vest Politechnic Univesity. Results and discussions: Subchondral bone presents osteolysis associated with a osteoporotic bone transformation. Pseudocystic chondrolisis was noted in the osteoarticular cartilage, in addition with areas of hemorrhagic postfractural necrosis. The osteoporotic bone exhibits ischemic necrosis and focal hemorrhagic necrosis adjacent fracture. Microporosity pattern of the bone observed by stereomicroscopy correspond to the spongy bone osteoporosis images. Morphometry of the bone spiculi reveals length of 154.88 and 498.32 μ. In men we found a greater thickness of bone trabeculi compared with bone texture porosity in women. The subchondral bone supports and fulfills an important role in transmitting forces from the overlying articular cartilage inducing the bone resorbtion. The femoral head fracture may be the final event of many accumulated bone microcracks. Conclusions: Bone fragility depends not only of the spongy bone but also of the cortical bone properties. Osteolysis produced by loss of balance in the process of remodeling in favor of bone resorption leads to the thinning of the subchondral bone at both sexes.

  15. In vitro study on the degradation of lithium-doped hydroxyapatite for bone tissue engineering scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yaping; Yang, Xu; Gu, Zhipeng; Qin, Huanhuan [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Li, Li [Department of Oncology, The 452 Hospital of Chinese PLA, Chengdu, Sichuan Province 610021 (China); Liu, Jingwang [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Yu, Xixun, E-mail: yuxixun@163.com [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China)

    2016-09-01

    Li-doped hydroxyapatite (LiHA) which is prepared through introducing low dose of Li into hydroxyapatite (HA) has been increasingly studied as a bone tissue-engineered scaffold. The degradation properties play a crucial role in the success of long-term implantation of a bone tissue-engineered construct. Herein, the in vitro degradation behaviors of LiHA scaffolds via two approaches were investigated in this study: solution-mediated degradation and osteoblast-mediated degradation. In solution-mediated degradation, after being immersed in simulated body fluid (SBF) for some time, some characteristics of these scaffolds (such as release of ionized lithium and phosphate, pH change, mechanical properties, cytocompatibility and SEM surface characterization) were systematically tested. A similar procedure was also employed to research the degradation behaviors of LiHA scaffolds in osteoblast-mediated degradation. The results suggested that the degradation in SBF and degradation in culture medium with cell existed distinguishing mechanisms. LiHA scaffolds were degraded via a hydrolytic mechanism when they were soaked in SBF. Upon degradation, an apatite precipitation (layer) was formed on the surfaces of scaffolds. While a biological mechanism was presented for the degradation of scaffolds in cell-mediated degradation. Compared with pure HA, LiHA scaffolds had a better effect on the growth of osteoblast cells, meanwhile, the release amount of PO{sub 4}{sup 3−} in a degradation medium indicated that osteoblasts could accelerate the degradation of LiHA due to the more physiological activities of osteoblast. According to the results from compressive strength test, doping Li into HA could enhance the strength of HA. Moreover, the results from MTT assay and SEM observation showed that the degradation products of LiHA scaffolds were beneficial to the proliferation of osteoblasts. The results of this research can provide the theoretical basis for the clinical application of Li

  16. Wollastonite nanofiber–doped self-setting calcium phosphate bioactive cement for bone tissue regeneration

    Directory of Open Access Journals (Sweden)

    Guo H

    2012-07-01

    incorporation of WNFs into CPC improved the biological properties for wnf-CPC. Following the implantation of wnf-CPC into bone defects of rabbits, histological evaluation showed that wnf-CPC enhanced the efficiency of new bone formation in comparison with CPC, indicating excellent biocompatibility and osteogenesis of wnf-CPC. In conclusion, wnf-CPC exhibited promising prospects in bone regeneration.Keywords: calcium phosphate cement, degradability, cell and tissue responses, biocompatibility

  17. Bioactive ceramic coating on orthopedic implants for enhanced bone tissue integration

    Science.gov (United States)

    Aniket

    Tissue integration between bone and orthopedic implant is essential for implant fixation and longevity. An immunological response leads to fibrous encapsulation of metallic implants leading to implant instability and failure. Bioactive ceramics have the ability to directly bond to bone; however, they have limited mechanical strength for load bearing applications. Coating bioactive ceramics on metallic implant offers the exciting opportunity to enhance bone formation without compromising the mechanical strength of the implant. In the present study, we have developed a novel bioactive silica-calcium phosphate nanocomposite (SCPC) coating on medical grade Ti-6Al-4V orthopedic implant using electrophoretic deposition (EPD) and evaluated bone tissue response to the coated implant at the cellular level. The effect of SCPC composition and suspending medium pH on the zeta potential of three different SCPC formulations; SCPC25, SCPC50 and SCPC75 were analyzed. The average zeta potential of SCPC50 in pure ethanol was more negative than that of SCPC25 or SCPC75; however the difference was not statistically significant. Ti-6Al-4V discs were passivated, coated with SCPC50 (200 nm - 10 mum) and thermally treated at 600 - 800 ºC to produce a coating thickness in the range of 43.1 +/- 5.7 to 30.1 +/- 4.6 μm. After treatment at 600, 700 and 800 ºC, the adhesion strength at the SCPC50/Ti-6Al-4V interface was 42.6 +/- 3.6, 44.7 +/- 8.7 and 47.2 +/- 4.3 MPa, respectively. XRD analyses of SCPC50 before and after EPD coating indicated no change in the crystallinity of the material. Fracture surface analyses showed that failure occurred within the ceramic layer or at the ceramic/polymer interface; however, the ceramic/metal interface was intact in all samples. The adhesion strength of SCPC50-coated substrates after immersion in PBS for 2 days (11.7 +/- 3.9 MPa) was higher than that measured on commercially available hydroxyapatite (HA) coated substrates (5.5 +/- 2.7 MPa), although the

  18. Low intensity pulsed ultrasound increases the mechanical properties of the healing tissues at bone-tendon junction.

    Science.gov (United States)

    Lu, Min-Hua; Zheng, Yong-Ping; Huang, Qing-Hua; Lu, Hong-Bin; Qin, Ling

    2009-01-01

    The re-establishment of bone-tendon junction (BTJ) tissues is involved in many trauma and reconstructive surgeries. A direct BTJ repair requires a long period of immobilization which may be associated with a postoperative weak knee. In this study, we investigated if low-intensity pulsed ultrasound treatment increases the material properties of healing tissues at bone-tendon junction (BTJ) after partial patellectomy using rabbit models. Standard partial patellectomy was conducted on one knee of twenty four rabbits which were randomly divided into an ultrasound group and a control group. The bony changes of BTJ complexes around the BTJ healing interface were measured by anteroposterior x-ray radiographs; then the volumetric bone-mineral density (BMD) of the new bone was assessed using a peripheral computed tomography scanner (pQCT). The stiffness of patellar cartilage, fibrocartilage at the healing interface and the tendon were measured in situ using a novel noncontact ultrasound water jet indentation system. Not only significantly more newly formed bone at the BTJ healing interface but also increased stiffness of the junction tissues were found in the ultrasound group compared with the controls at week 18. In addition, the ultrasound group also showed significantly 44% higher BMD at week 6 than controls.

  19. Nanocomposite scaffolds with tunable mechanical and degradation capabilities: co-delivery of bioactive agents for bone tissue engineering.

    Science.gov (United States)

    Cattalini, Juan P; Roether, Judith; Hoppe, Alexander; Pishbin, Fatemeh; Haro Durand, Luis; Gorustovich, Alejandro; Boccaccini, Aldo R; Lucangioli, Silvia; Mouriño, Viviana

    2016-10-21

    Novel multifunctional nanocomposite scaffolds made of nanobioactive glass and alginate crosslinked with therapeutic ions such as calcium and copper were developed for delivering therapeutic agents, in a highly controlled and sustainable manner, for bone tissue engineering. Alendronate, a well-known antiresorptive agent, was formulated into microspheres under optimized conditions and effectively loaded within the novel multifunctional scaffolds with a high encapsulation percentage. The size of the cation used for the alginate crosslinking impacted directly on porosity and viscoelastic properties, and thus, on the degradation rate and the release profile of copper, calcium and alendronate. According to this, even though highly porous structures were created with suitable pore sizes for cell ingrowth and vascularization in both cases, copper-crosslinked scaffolds showed higher values of porosity, elastic modulus, degradation rate and the amount of copper and alendronate released, when compared with calcium-crosslinked scaffolds. In addition, in all cases, the scaffolds showed bioactivity and mechanical properties close to the endogenous trabecular bone tissue in terms of viscoelasticity. Furthermore, the scaffolds showed osteogenic and angiogenic properties on bone and endothelial cells, respectively, and the extracts of the biomaterials used promoted the formation of blood vessels in an ex vivo model. These new bioactive nanocomposite scaffolds represent an exciting new class of therapeutic cell delivery carrier with tunable mechanical and degradation properties; potentially useful in the controlled and sustainable delivery of therapeutic agents with active roles in bone formation and angiogenesis, as well as in the support of cell proliferation and osteogenesis for bone tissue engineering.

  20. The Design and Use of Animal Models for Translational Research in Bone Tissue Engineering and Regenerative Medicine

    Science.gov (United States)

    2010-01-07

    repair,40,41 evaluation of the differential effects of marrow-derived and periosteal - derived cell populations,42 and in screening for the effects of cell...defect or gap in bone (caused by either tissue loss or distraction maintained by internal or external fixation), local tissue loss (particularly periosteal ...as an excel- lent resource. Critical defects are defined as ‘‘a defect that will not heal without intervention.’’ The femur and tibial diaphysis tend

  1. Potent effect of zinc acexamate on bone components in the femoral-metaphyseal tissues of elderly female rats.

    Science.gov (United States)

    Yamaguchi, M; Gao, Y H

    1998-03-01

    1. The effect of zinc compounds on bone components in the femoral-metaphyseal tissues from elderly female rats (50 weeks old) was investigated in vitro. Bone tissues were cultured for 24 hr in Dulbecco's modified Eagle medium containing either vehicle or zinc compounds (10[-7] to 10[-5] M). 2. Zinc content, alkaline phosphatase activity, deoxyribonucleic acid (DNA) and calcium contents in the metaphyseal tissues were significantly increased by the presence of zinc sulfate (10[-6] and 10[-5] M), beta-alanyl-L-histidinato zinc (AHZ; 10[-6] and 10[-5] M) and zinc acexamate (10[-7] to 10[-5] M). At 10[-5] M, the effect of zinc acexamate on the increase of bone components was more potent than that of zinc sulfate or AHZ. 3. The effect of zinc acexamate (10[-5] M) on the increase of alkaline phosphatase activity in the metaphyseal tissues was remarkable as compared with that of insulin (10[-8] M), estrogen (10[-9] M), insulin-like growth factor-I (10[-8] M), transforming growth factor-beta (10[-10] M), sodium fluoride (10[-3] M), dexamethasone (10[-7] M) and vitamin K2 (menaquinone-4; 10[-5] M) with an effective concentration. 4. The stimulatory effect of zinc acexamate (10[-5] M) on alkaline phosphatase activity and calcium content in the metaphyseal tissues was completely blocked by the presence of dipicolinate (10[-3] M), a chelator of zinc ion, and of cycloheximide (10[-6] M), an inhibitor of protein synthesis. 5. The present study demonstrates that zinc acexamate has a potent anabolic effect on bone components in the femoral-metaphyseal tissues from female elderly rats in vitro. The effect of zinc acexamate may be based in part on protein synthesis related to zinc ion in bone cells.

  2. Bone marrow–derived circulating progenitor cells fail to transdifferentiate into adipocytes in adult adipose tissues in mice

    Science.gov (United States)

    Koh, Young Jun; Kang, Shinae; Lee, Hyuek Jong; Choi, Tae-Saeng; Lee, Ho Sub; Cho, Chung-Hyun; Koh, Gou Young

    2007-01-01

    Little is known about whether bone marrow–derived circulating progenitor cells (BMDCPCs) can transdifferentiate into adipocytes in adipose tissues or play a role in expanding adipocyte number during adipose tissue growth. Using a mouse bone marrow transplantation model, we addressed whether BMDCPCs can transdifferentiate into adipocytes under standard conditions as well as in the settings of diet-induced obesity, rosiglitazone treatment, and exposure to G-CSF. We also addressed the possibility of transdifferentiation to adipocytes in a murine parabiosis model. In each of these settings, our findings indicated that BMDCPCs did not transdifferentiate into either unilocular or multilocular adipocytes in adipose tissues. Most BMDCPCs became resident and phagocytic macrophages in adipose tissues — which resembled transdifferentiated multilocular adipocytes by appearance, but displayed cell surface markers characteristic for macrophages — in the absence of adipocyte marker expression. When exposed to adipogenic medium in vitro, bone marrow cells differentiated into multilocular, but not unilocular, adipocytes, but transdifferentiation was not observed in vivo, even in the contexts of adipose tissue regrowth or dermal wound healing. Our results suggest that BMDCPCs do not transdifferentiate into adipocytes in vivo and play little, if any, role in expanding the number of adipocytes during the growth of adipose tissues. PMID:18060029

  3. Functionally graded PCL/ β-TCP biocomposites in a multilayered structure for bone tissue regeneration

    Science.gov (United States)

    Kim, Yong Bok; Kim, GeunHyung

    2012-09-01

    Functionally graded (FG) composites consisting of polycaprolactone (PCL) and beta-tricalcium phosphate ( β-TCP) particles were fabricated with a multilayered structure using a melt plotter with a two-heating-barrel system. Using this process, the concentration of β-TCP particles varied in each layered strut. Scanning electron microscopy (SEM) and energy dispersive spectroscopy mapping of calcium on the fabricated scaffolds indicated that the β-TCP particles were well distributed in each PCL strut, according to conceptual design. By incorporating β-TCP, the FG-PCL/ β-TCP scaffolds had meaningful increases in water absorption (30 % increase) and showed good mechanical properties, although the mechanical properties are slightly low compared to pure PCL/ β-TCP composite. We performed biological assessments to evaluate the capability of these FG scaffolds to act as a biomaterial for bone tissue regeneration with osteoblast-like cells (MG63). SEM images of cell-seeded FG scaffolds showed that the concentrated β-TCP struts were affected as good cell attachment/proliferation sites. Additionally, calcium deposition on the FG scaffolds was higher than that of normal scaffolds after 14 days. In particular, we observed high levels of mineralization in the highly concentrated β-TCP struts in the FG scaffolds. Based on these results, we believe that the FG scaffolds having various spatially designed structures with graded properties will be widely applicable for hard tissue engineering applications.

  4. Polycaprolactone scaffolds fabricated with an advanced electrohydrodynamic direct-printing method for bone tissue regeneration.

    Science.gov (United States)

    Ahn, Seung Hyun; Lee, Hyeong Jin; Kim, Geun Hyung

    2011-12-12

    Electrohydrodynamic (EHD) direct writing has been used in diverse microelectromechanical systems and various supplemental methods for biotechnology and electronics. In this work, we expanded the use of EHD-induced direct writing to fabricate 3D biomedical scaffolds designed as porous structures for bone tissue engineering. To prepare the scaffolds, we modified a grounded target used in conventional EHD direct printing using a poly(ethylene oxide) solution bath, elastically cushioning the plotted struts to prevent crumbling. The fabricated scaffolds were assessed for not only physical properties including surface roughness and water uptake ability but also biological capabilities by culturing osteoblast-like cells (MG63) for the EHD-plotted polycaprolactone (PCL) scaffold. The EHD-scaffolds showed significantly roughened surface and enhanced water-absorption ability (400% increase) compared with the pure rapid-prototyped PCL. The results of cell viability, alkaline phosphatase activity, and mineralization analyses showed significantly enhanced biological properties of the scaffold (20 times the cell viability and 6 times the mineralization) compared with the scaffolds fabricated using RP technology. Because of the results, the modified EHD direct-writing process can be a promising method for fabricating 3D biomedical scaffolds in tissue engineering.

  5. Combining collagen and bioactive glasses for bone tissue engineering: a review.

    Science.gov (United States)

    Sarker, Bapi; Hum, Jasmin; Nazhat, Showan N; Boccaccini, Aldo R

    2015-01-28

    Collagen (COL), the most abundant protein in mammals, offers a wide range of attractive properties for biomedical applications which are the result of its biocompatibility and high affinity to water. However, due to the relative low mechanical properties of COL its applications are still limited. To tackle this disadvantage of COL, especially in the field of bone tissue engineering, COL can be combined with bioactive inorganic materials in a variety of composite systems. One of such systems is the collagen-bioactive glass (COL-BG) composite family, which is the theme of this Review. BG fillers can increase compressive strength and stiffness of COL-based structures. This article reviews the relevant literature published in the last 15 years discussing the fabrication of a variety of COL-BG composites. In vitro cell studies have demonstrated the osteogenic, odontogenic, and angiogenic potential of these composite systems, which has been confirmed by stimulating specific biochemical indicators of relevant cells. Bony integration and connective tissue vessel formation have also been studied by implantation of the composites in vivo. Areas of future research in the field of COL-BG systems, based on current challenges, and gaps in knowledge are highlighted.

  6. Space simulations of thermal fields generated in bone tissue for application to nanophotohyperthermia and nanophotothermolysis

    Science.gov (United States)

    Letfullin, Renat R.; Rice, Colin E. W.; George, Thomas F.

    2011-03-01

    The use of nanoparticles in medical applications has been gaining momentum as antibody-conjugated nanoparticles are becoming more and more feasible as a means of targeted delivery of various therapies. Irradiating nanoparticles with light of strongly-absorbed wavelengths allows them to act as heat generation sites. Two therapies utilize these nanoparticle heat sources to kill the target cells: nanophotohyperthermia, which heats the particles just enough to disrupt cell function and trigger cell death; and nanophotothermolysis, which heats the particles to such extremes as to destroy the cell membrane. The use of optical wavelengths in the range of 750-1100 nm has been to capitalize on the "optical transparency window" of biotissues between the absorption peaks of hemoglobin in the visible end and water in the near-IR. However, further research has shown that a plasmon resonance can greatly affect the absorption characteristics of nanoparticles at the plasmon resonant frequency, allowing for increased absorption characteristics at desirable wavelengths. Thus, other transparency windows may find use in a similar manner, such as nanoparticle heating by RF waves. This paper presents the modeling of 3D thermal fields around nanoparticle absorbers in bone tissue for various frequencies. A comparison of the heating effectiveness across multiple wavelengths is discussed for application to nanophotothermolysis and nanophotohyperthermia treatments in or near biological hard tissue.

  7. Poly (lactide-co-glycolide nanofibers coated with collagen and nano-hydroxyapatite for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Reza Tavakoli-Darestani

    2013-05-01

    Full Text Available Please cite this article as: Tavakoli-Darestani R, Kazemian GH, Emami M, Kamrani-Rad A. Poly (lactide-co-glycolide nanofibers coated with collagen and nano-hydroxyapatite for bone tissue engineering. Novel Biomed 2013;1:8-15.Background: A combination of polymeric nanofibrous scaffold and bioactive materials is potentially useful in bone regeneration applications.Materials and Methods: In the present study, Poly (lactide-co-glycolide (PLGA nanofibrous scaffolds, fabricated via electrospinning, were initially coated with Type I collagen and then with nano-hydroxyapatite. The prepared scaffolds were then characterized using SEM and their ability for bone regeneration was investigated in a rat critical size bone defect using digital mammography, multislice spiral-computed tomography (MSCT imaging, and histological analysis.Results: Electrospun scaffolds had nanofibrous structure with homogenous distribution of n-HA on collagen-grafted PLGA. After 8 weeks of implantation, no sign of inflammation or complication was observed at the site of surgery. According to digital mammography and MSCT, PLGA nanofibers coated simultaneously with collagen and HA showed the highest regeneration in rat calvarium. In addition, no significant difference was observed in bone repair in the group which received PLGA and the untreated control. This amount was lower than that observed in the group implanted with collagen-coated PLGA. Histological studies confirmed these data and showed osteointegration to the surrounding tissue.Conclusion: Taking all together, it was demonstrated that nanofibrous structures can be used as appropriate support for tissue-engineered scaffolds, and coating them with bioactive materials will provide ideal synthetic grafts. Fabricated PLGA coated with Type I collagen and HA can be used as new bone graft substitutes in orthopaedic surgery and is capable of enhancing bone regeneration via characteristics such as osteoconductivity and

  8. CNS Metastases from Bone and Soft Tissue Sarcomas in Children, Adolescents, and Young Adults: Are They Really So Rare?

    Directory of Open Access Journals (Sweden)

    Monika Bekiesinska-Figatowska

    2017-01-01

    Full Text Available Purpose. To check whether primary involvement of brain/spinal cord by bone/soft tissue sarcomas’ metastases in children is as rare as described and to present various morphological forms of bone/soft tissue sarcomas’ CNS metastases. Methods. Patients with first diagnosis in 1999–2014 treated at single center were included with whole course of disease evaluation. Brain/spinal canal magnetic resonance imaging (MRI/computed tomography were performed in cases suspicious for CNS metastases. Extension from skull/vertebral column metastases was excluded. Results. 550 patients were included. MRI revealed CNS metastases in 19 patients (incidence 3.45%, 14 boys, aged 5–22 years. There were 12/250 osteosarcoma cases, 2/200 Ewing’s sarcoma, 1/50 chondrosarcoma, 3/49 rhabdomyosarcoma (RMS, and 1/1 malignant mesenchymoma. There were 10 single metastases and 7 cases of multiple ones; in 2 RMS cases only leptomeningeal spread in brain and spinal cord was found. Calcified metastases were found in 3 patients and hemorrhagic in 4. In one RMS patient there were numerous solid, cystic, hemorrhagic lesions and leptomeningeal spread. Conclusions. CNS metastases are rare and late in children with bone/soft tissue sarcomas, although in our material more frequent (3.45% than in other reports (0.7%. Hematogenous spread to brain and hemorrhagic and calcified lesions dominated in osteosarcoma. Ewing sarcoma tended to metastasize to skull bones. Soft tissue sarcomas presented various morphological forms.

  9. CNS Metastases from Bone and Soft Tissue Sarcomas in Children, Adolescents, and Young Adults: Are They Really So Rare?

    Science.gov (United States)

    Duczkowska, Agnieszka; Duczkowski, Marek; Bragoszewska, Hanna; Romaniuk-Doroszewska, Anna; Iwanowska, Beata; Szkudlinska-Pawlak, Sylwia; Madzik, Jaroslaw; Bilska, Katarzyna; Raciborska, Anna

    2017-01-01

    Purpose. To check whether primary involvement of brain/spinal cord by bone/soft tissue sarcomas' metastases in children is as rare as described and to present various morphological forms of bone/soft tissue sarcomas' CNS metastases. Methods. Patients with first diagnosis in 1999–2014 treated at single center were included with whole course of disease evaluation. Brain/spinal canal magnetic resonance imaging (MRI)/computed tomography were performed in cases suspicious for CNS metastases. Extension from skull/vertebral column metastases was excluded. Results. 550 patients were included. MRI revealed CNS metastases in 19 patients (incidence 3.45%), 14 boys, aged 5–22 years. There were 12/250 osteosarcoma cases, 2/200 Ewing's sarcoma, 1/50 chondrosarcoma, 3/49 rhabdomyosarcoma (RMS), and 1/1 malignant mesenchymoma. There were 10 single metastases and 7 cases of multiple ones; in 2 RMS cases only leptomeningeal spread in brain and spinal cord was found. Calcified metastases were found in 3 patients and hemorrhagic in 4. In one RMS patient there were numerous solid, cystic, hemorrhagic lesions and leptomeningeal spread. Conclusions. CNS metastases are rare and late in children with bone/soft tissue sarcomas, although in our material more frequent (3.45%) than in other reports (0.7%). Hematogenous spread to brain and hemorrhagic and calcified lesions dominated in osteosarcoma. Ewing sarcoma tended to metastasize to skull bones. Soft tissue sarcomas presented various morphological forms.

  10. Prolonged bone marrow T1-relaxation in acute leukaemia. In vivo tissue characterization by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Thomsen, C; Sørensen, P G; Karle, H;

    1987-01-01

    osseous tissue. Nine patients with acute leukaemia, one patient with myelodysplastic syndrome, and ten normal volunteers were included in the study. The T1- and T2-relaxation processes were measured in the lumbar spine bone marrow using a wholebody superconductive MR-scanner operating at 1.5 Tesla...

  11. Autologously generated tissue-engineered bone flaps for reconstruction of large mandibular defects in an ovine model.

    NARCIS (Netherlands)

    Tatara, A.M.; Kretlow, J.D.; Spicer, P.P.; Lu, S.; Lam, J.; Liu, W.; Cao, Y.; Liu, G.; Jackson, J.D.; Yoo, J.J.; Atala, A.; Beucken, J.J.J.P van den; Jansen, J.A.; Kasper, F.K.; Ho, T.; Demian, N.; Miller, M.J.; Wong, M.E.; Mikos, A.G.

    2015-01-01

    The reconstruction of large craniofacial defects remains a significant clinical challenge. The complex geometry of facial bone and the lack of suitable donor tissue often hinders successful repair. One strategy to address both of these difficulties is the development of an in vivo bioreactor, where

  12. Mineral density and biomechanical properties of bone tissue from male Arctic foxes (Vulpes lagopus) exposed to organochlorine contaminants and emaciation

    DEFF Research Database (Denmark)

    Sonne, Christian; Wolkers, Hans; Rigét, Frank F;

    2008-01-01

    We investigated the impact from dietary OC (organochlorine) exposure and restricted feeding (emaciation) on bone mineral density (BMD; g hydroxy-apatite cm(-2)) in femoral, vertebrate, skull and baculum osteoid tissue from farmed Arctic blue foxes (Vulpes lagopus). For femur, also biomechanical...

  13. The tent pole splint: a bone-supported stereolithographic surgical splint for the soft tissue matrix expansion graft procedure.

    Science.gov (United States)

    Cillo, Joseph E; Theodotou, Nicholas; Samuels, Marc; Krajekian, Joseph

    2010-06-01

    This report details the use of computer-aided planning and intraoperative stereolithographic direct-bone-contact surgical splints for the accurate extraoral placement of dental implants in the soft tissue matrix expansion (tent pole) graft of the severely resorbed mandible.

  14. EFFECT OF OXIDATIVE STRESS ON HISTOARCHITECTONICS AND ELEMENTAL COMPOSITION OF BONE TISSUE OF THE VERTEBRAL BODY RATS

    Directory of Open Access Journals (Sweden)

    S. N. Lukanina

    2015-01-01

    Full Text Available This paper is concerned with study an influence of the oxidative stress on morphofunctional characteris-tics and elemental composition of bone tissue of the vertebral body rats.Material and methods. The research carried out on male rats of the Wistar line with weight 250–300 g. All rats were categorized into 4 groups with 10 ones in each: 1 – intact group; 2 and 3 – experimental groups; 4 – control group. Rats from groups 2–4 were under the development of oxidized stress which caused by daily stomach-pump injection (during fortnight with aqua suspension of synthetic glucocorticoid “Prednisolone” in dose 50 mg/kg. Through three hours after “Prednisolone” the antioxidant “Tiophan” was injected by stomach-pump (dose 100 mg/kg, which was dissolved in 0.2 ml of vegetation oil to laboratory animals from the group 2. Rats from control group got only solvent (vegetative oil 0.2 ml according the same scheme. Three hours after “Prednisolone” to rats from group 3 were injected of 0.2 ml aquaFontana. It was made for purity the experiment and standartization of manipulations, which are connected with injections into rats’ organisms. The peculiarities of structure of bone tissue of vertebra have been studied by methods of morphohystochemical analysis. The elemental composition of bone tissue was defined by atom-emission analysis method with inductive coupled plasma (spectrometer OPTIMA, code of methodics KHA: MUK.4.1.1482-03.Results. A development of glucocorticoid-induced oxidative stress results to infraction the histoarchitectonics of bone tissue of vertebra and decreasing the content of cations, which are included to the composition of active centres of pherments of antioxidant protection and prosthetic groups of proteins with an antioxidant activity. Using the antioxidant “Tiophan” proved an existence of its expressed osteoprotective properties. This can be seen from decreasing a level of resorbtion of bone tissue of

  15. Decreased bone tissue mineralization can partly explain subchondral sclerosis observed in osteoarthritis.

    Science.gov (United States)

    Cox, L G E; van Donkelaar, C C; van Rietbergen, B; Emans, P J; Ito, K

    2012-05-01

    For many years, pharmaceutical therapies for osteoarthritis (OA) were focused on cartilage. However, it has been theorized that bone changes such as increased bone volume fraction and decreased bone matrix mineralization may play an important role in the initiation and pathogenesis of OA as well. The mechanisms behind the bone changes are subject of debate, and a better understanding may help in the development of bone-targeting OA therapies. In the literature, the increase in bone volume fraction has been hypothesized to result from mechanoregulated bone adaptation in response to decreased mineralization. Furthermore, both changes in bone volume fraction and mineralization have been reported to be highest close to the cartilage, and bone volume fraction has been reported to be correlated with cartilage degeneration. These data indicate that cartilage degeneration, bone volume fraction, and bone matrix mineralization may be related in OA. In the current study, we aimed to investigate the relationships between cartilage degeneration, bone matrix mineralization and bone volume fraction at a local level. With microCT, we determined bone matrix mineralization and bone volume fraction as a function of distance from the cartilage in osteochondral plugs from human OA tibia plateaus with varying degrees of cartilage degeneration. In addition, we evaluated whether mechanoregulated bone adaptation in response to decreased bone matrix mineralization may be responsible for the increase in bone volume fraction observed in OA. For this purpose, we used the experimentally obtained mineralization data as input for bone adaptation simulations. We simulated the effect of mechanoregulated bone adaptation in response to different degrees of mineralization, and compared the simulation results to the experimental data. We found that local changes in subchondral bone mineralization and bone volume fraction only occurred underneath severely degenerated cartilage, indicating that bone

  16. Assessment of image quality in soft tissue and bone visualization tasks for a dedicated extremity cone-beam CT system

    Energy Technology Data Exchange (ETDEWEB)

    Demehri, S. [Johns Hopkins University, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Johns Hopkins Outpatient Center, JHOC 5168, Musculoskeletal Radiology, Baltimore, MD (United States); Muhit, A.; Zbijewski, W.; Stayman, J.W. [Johns Hopkins University, Department of Biomedical Engineering, Baltimore, MD (United States); Yorkston, J.; Packard, N.; Senn, R.; Yang, D.; Foos, D. [Carestream Health, Rochester, NY (United States); Thawait, G.K.; Fayad, L.M.; Chhabra, A.; Carrino, J.A. [Johns Hopkins University, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Siewerdsen, J.H. [Johns Hopkins University, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Johns Hopkins University, Department of Biomedical Engineering, Baltimore, MD (United States)

    2015-06-01

    To assess visualization tasks using cone-beam CT (CBCT) compared to multi-detector CT (MDCT) for musculoskeletal extremity imaging. Ten cadaveric hands and ten knees were examined using a dedicated CBCT prototype and a clinical multi-detector CT using nominal protocols (80kVp-108mAs for CBCT; 120kVp- 300mAs for MDCT). Soft tissue and bone visualization tasks were assessed by four radiologists using five-point satisfaction (for CBCT and MDCT individually) and five-point preference (side-by-side CBCT versus MDCT image quality comparison) rating tests. Ratings were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests, and observer agreement was assessed using the Kappa-statistic. Knee CBCT images were rated ''excellent'' or ''good'' (median scores 5 and 4) for ''bone'' and ''soft tissue'' visualization tasks. Hand CBCT images were rated ''excellent'' or ''adequate'' (median scores 5 and 3) for ''bone'' and ''soft tissue'' visualization tasks. Preference tests rated CBCT equivalent or superior to MDCT for bone visualization and favoured the MDCT for soft tissue visualization tasks. Intraobserver agreement for CBCT satisfaction tests was fair to almost perfect (κ ∝ 0.26-0.92), and interobserver agreement was fair to moderate (κ ∝ 0.27-0.54). CBCT provided excellent image quality for bone visualization and adequate image quality for soft tissue visualization tasks. (orig.)

  17. Unique local bone tissue characteristics in iliac crest bone biopsy from adolescent idiopathic scoliosis with severe spinal deformity

    Science.gov (United States)

    Wang, Zhiwei; Chen, Huanxiong; Yu, Y. Eric; Zhang, Jiajun; Cheuk, Ka-Yee; Ng, Bobby K. W.; Qiu, Yong; Guo, X. Edward; Cheng, Jack C. Y.; Lee, Wayne Y. W.

    2017-01-01

    Adolescent idiopathic scoliosis is a complex disease with unclear etiopathogenesis. Systemic and persistent low bone mineral density is an independent prognostic factor for curve progression. The fundamental question of how bone quality is affected in AIS remains controversy because there is lack of site-matched control for detailed analysis on bone-related parameters. In this case-control study, trabecular bone biopsies from iliac crest were collected intra-operatively from 28 severe AIS patients and 10 matched controls with similar skeletal and sexual maturity, anthropometry and femoral neck BMD Z-score to control confounding effects. In addition to static histomorphometry, micro-computed tomography (μCT) and real time-PCR (qPCR) analyses, individual trabecula segmentation (ITS)-based analysis, finite element analysis (FEA), energy dispersive X-ray spectroscopy (EDX) were conducted to provide advanced analysis of structural, mechanical and mineralization features. μCT and histomorphometry showed consistently reduced trabecular number and connectivity. ITS revealed predominant change in trabecular rods, and EDX confirmed less mineralization. The structural and mineralization abnormality led to slight reduction in apparent modulus, which could be attributed to differential down-regulation of Runx2, and up-regulation of Spp1 and TRAP. In conclusion, this is the first comprehensive study providing direct evidence of undefined unique pathological changes at different bone hierarchical levels in AIS. PMID:28054655

  18. A novel squid pen chitosan/hydroxyapatite/β-tricalcium phosphate composite for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shavandi, Amin, E-mail: amin.shavandi@postgrad.otago.ac.nz [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Department of Applied Sciences, University of Otago, Dunedin (New Zealand); Bekhit, Alaa El-Din A. [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Sun, Zhifa; Ali, Azam [Department of Physics, University of Otago, Dunedin (New Zealand); Gould, Maree [Department of Anatomy, University of Otago, Dunedin (New Zealand)

    2015-10-01

    Squid pen chitosan was used in the fabrication of biocomposite scaffolds for bone tissue engineering. Hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) obtained from waste mussel shells were used as the calcium phosphate source. The composite was prepared using 2.5% tripolyphosphate (TPP) and 1% glycerol as a cross-linker and plasticizer, respectively. The weight percent (wt.%) ratios of the ceramic components in the composite were 20/10/70, 30/20/50 and 40/30/30 (HA/β-TCP/Chi). The biodegradation rate and structural properties of the scaffolds were investigated. Scanning electron microscopy (SEM) and microCT(μCT) results indicated that the composites have a well defined lamellar structure with an average pore size of 200 μm. The porosity of the composites decreased from 88 to 56% by increasing the ratio of HA/β-TCP from 30 to 70%. After 28 days of incubation in a physiological solution, the scaffolds were degraded by approximately 30%. In vitro investigations showed that the composites were cytocompatible and supported the growth of L929 and Saos-2 cells. The obtained data suggests that the squid pen chitosan composites are potential candidates for bone regeneration. - Highlights: • Biocomposite scaffolds were made from mussel shells HA and β-TCP, and squid pin chitosan. • The porosity of the composites decreased with an increase in HA/β-TCP ratio. • Composites were cytocompatible and supported the growth of L929 and Saos-2 cells. • Composite containing 50% HA and β-TCP had the best mechanical properties.

  19. Fabrication of individual alginate-TCP scaffolds for bone tissue engineering by means of powder printing.

    Science.gov (United States)

    Castilho, Miguel; Rodrigues, Jorge; Pires, Inês; Gouveia, Barbara; Pereira, Manuel; Moseke, Claus; Groll, Jürgen; Ewald, Andrea; Vorndran, Elke

    2015-01-06

    The development of polymer-calcium phosphate composite scaffolds with tailored architectures and properties has great potential for bone regeneration. Herein, we aimed to improve the functional performance of brittle ceramic scaffolds by developing a promising biopolymer-ceramic network. For this purpose, two strategies, namely, direct printing of a powder composition consisting of a 60:40 mixture of α/β-tricalcium phosphate (TCP) powder and alginate powder or vacuum infiltration of printed TCP scaffolds with an alginate solution, were tracked. Results of structural characterization revealed that the scaffolds printed with 2.5 wt% alginate-modified TCP powders presented a uniformly distributed and interfusing alginate TCP network. Mechanical results indicated a significant increase in strength, energy to failure and reliability of powder-modified scaffolds with an alginate content in the educts of 2.5 wt% when compared to pure TCP, as well as to TCP scaffolds containing 5 wt% or 7.5 wt% in the educts, in both dry and wet states. Culture of human osteoblast cells on these scaffolds also demonstrated a great improvement of cell proliferation and cell viability. While in the case of powder-mixed alginate TCP scaffolds, isolated alginate gels were formed between the calcium phosphate crystals, the vacuum-infiltration strategy resulted in the covering of the surface and internal pores of the TCP scaffold with a thin alginate film. Furthermore, the prediction of the scaffolds' critical fracture conditions under more complex stress states by the applied Mohr fracture criterion confirmed the potential of the powder-modified scaffolds with 2.5 wt% alginate in the educts as structural biomaterial for bone tissue engineering.

  20. Calcium silicate ceramic scaffolds toughened with hydroxyapatite whiskers for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Pei [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Wei, Pingpin [Cancer Research Institute, Central South University, Changsha 410078 (China); Li, Pengjian; Gao, Chengde [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Shuai, Cijun, E-mail: shuai@csu.edu.cn [State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, PR China, (China); Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425 (United States); Peng, Shuping, E-mail: shuping@csu.edu.cn [Cancer Research Institute, Central South University, Changsha 410078 (China)

    2014-11-15

    Calcium silicate possessed excellent biocompatibility, bioactivity and degradability, while the high brittleness limited its application in load-bearing sites. Hydroxyapatite whiskers ranging from 0 to 30 wt.% were incorporated into the calcium silicate matrix to improve the strength and fracture resistance. Porous scaffolds were fabricated by selective laser sintering. The effects of hydroxyapatite whiskers on the mechanical properties and toughening mechanisms were investigated. The results showed that the scaffolds had a uniform and continuous inner network with the pore size ranging between 0.5 mm and 0.8 mm. The mechanical properties were enhanced with increasing hydroxyapatite whiskers, reached a maximum at 20 wt.% (compressive strength: 27.28 MPa, compressive Young's modulus: 156.2 MPa, flexural strength: 15.64 MPa and fracture toughness: 1.43 MPa·m{sup 1/2}) and then decreased by addition of more hydroxyapatite whiskers. The improvement of mechanical properties was due to whisker pull-out, crack deflection and crack bridging. Moreover, the degradation rate decreased with the increase of hydroxyapatite whisker content. A layer of bone-like apatite was formed on the scaffold surfaces after being soaked in simulated body fluid. Human osteoblast-like MG-63 cells spread well on the scaffolds and proliferated with increasing culture time. These findings suggested that the calcium silicate scaffolds reinforced with hydroxyapatite whiskers showed great potential for bone regeneration and tissue engineering applications. - Highlights: • HA whiskers were incorporated into CS to improve the properties. • The scaffolds were successfully fabricated by SLS. • Toughening mechanisms was whisker pull-out, crack deflection and bridging. • The scaffolds showed excellent apatite forming ability.

  1. Rapid maxillary expansion in alveolar cleft repaired with a tissue-engineered bone in a canine model.

    Science.gov (United States)

    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.

  2. Polymer-ceramic spiral structured scaffolds for bone tissue engineering: effect of hydroxyapatite composition on human fetal osteoblasts.

    Science.gov (United States)

    Zhang, Xiaojun; Chang, Wei; Lee, Paul; Wang, Yuhao; Yang, Min; Li, Jun; Kumbar, Sangamesh G; Yu, Xiaojun

    2014-01-01

    For successful bone tissue engineering, a scaffold needs to be osteoconductive, porous, and biodegradable, thus able to support attachment and proliferation of bone cells and guide bone formation. Recently, hydroxyapatites (HA), a major inorganic component of natural bone, and biodegrade polymers have drawn much attention as bone scaffolds. The present study was designed to investigate whether the bone regenerative properties of nano-HA/polycaprolactone (PCL) spiral scaffolds are augmented in an HA dose dependent manner, thereby establishing a suitable composition as a bone formation material. Nano-HA/PCL spiral scaffolds were prepared with different weight ratios of HA and PCL, while porosity was introduced by a modified salt leaching technique. Human fetal osteoblasts (hFOBs) were cultured on the nano-HA/PCL spiral scaffolds up to 14 days. Cellular responses in terms of cell adhesion, viability, proliferation, differentiation, and the expression of bone-related genes were investigated. These scaffolds supported hFOBs adhesion, viability and proliferation. Cell proliferation trend was quite similar on polymer-ceramic and neat polymer spiral scaffolds on days 1, 7, and 14. However, the significantly increased amount of alkaline phosphatase (ALP) activity and mineralized matrix synthesis was evident on the nano-HA/PCL spiral scaffolds. The HA composition in the scaffolds showed a significant effect on ALP and mineralization. Bone phenotypic markers such as bone sialoprotein (BSP), osteonectin (ON), osteocalcin (OC), and type I collagen (Col-1) were semi-quantitatively estimated by reverse transcriptase polymerase chain reaction analysis. All of these results suggested the osteoconductive characteristics of HA/PCL nanocomposite and cell maturation were HA dose dependent. For instance, HA∶PCL = 1∶4 group showed significantly higher ALP mineralization and elevated levels of BSP, ON, OC and Col-I expression as compared other lower or higher ceramic ratios

  3. Polymer-ceramic spiral structured scaffolds for bone tissue engineering: effect of hydroxyapatite composition on human fetal osteoblasts.

    Directory of Open Access Journals (Sweden)

    Xiaojun Zhang

    Full Text Available For successful bone tissue engineering, a scaffold needs to be osteoconductive, porous, and biodegradable, thus able to support attachment and proliferation of bone cells and guide bone formation. Recently, hydroxyapatites (HA, a major inorganic component of natural bone, and biodegrade polymers have drawn much attention as bone scaffolds. The present study was designed to investigate whether the bone regenerative properties of nano-HA/polycaprolactone (PCL spiral scaffolds are augmented in an HA dose dependent manner, thereby establishing a suitable composition as a bone formation material. Nano-HA/PCL spiral scaffolds were prepared with different weight ratios of HA and PCL, while porosity was introduced by a modified salt leaching technique. Human fetal osteoblasts (hFOBs were cultured on the nano-HA/PCL spiral scaffolds up to 14 days. Cellular responses in terms of cell adhesion, viability, proliferation, differentiation, and the expression of bone-related genes were investigated. These scaffolds supported hFOBs adhesion, viability and proliferation. Cell proliferation trend was quite similar on polymer-ceramic and neat polymer spiral scaffolds on days 1, 7, and 14. However, the significantly increased amount of alkaline phosphatase (ALP activity and mineralized matrix synthesis was evident on the nano-HA/PCL spiral scaffolds. The HA composition in the scaffolds showed a significant effect on ALP and mineralization. Bone phenotypic markers such as bone sialoprotein (BSP, osteonectin (ON, osteocalcin (OC, and type I collagen (Col-1 were semi-quantitatively estimated by reverse transcriptase polymerase chain reaction analysis. All of these results suggested the osteoconductive characteristics of HA/PCL nanocomposite and cell maturation were HA dose dependent. For instance, HA∶PCL = 1∶4 group showed significantly higher ALP mineralization and elevated levels of BSP, ON, OC and Col-I expression as compared other lower or higher ceramic

  4. Validation of scaffold design optimization in bone tissue engineering: finite element modeling versus designed experiments.

    Science.gov (United States)

    Uth, Nicholas; Mueller, Jens; Smucker, Byran; Yousefi, Azizeh-Mitra

    2017-02-21

    This study reports the development of biological/synthetic scaffolds for bone tissue engineering (TE) via 3D bioplotting. These scaffolds were composed of poly(L-lactic-co-glycolic acid) (PLGA), type I collagen, and nano-hydroxyapatite (nHA) in an attempt to mimic the extracellular matrix of bone. The solvent used for processing the scaffolds was 1,1,1,3,3,3-hexafluoro-2-propanol. The produced scaffolds were characterized by scanning electron microscopy, microcomputed tomography, thermogravimetric analysis, and unconfined compression test. This study also sought to validate the use of finite-element optimization in COMSOL Multiphysics for scaffold design. Scaffold topology was simplified to three factors: nHA content, strand diameter, and strand spacing. These factors affect the ability of the scaffold to bear mechanical loads and how porous the structure can be. Twenty four scaffolds were constructed according to an I-optimal, split-plot designed experiment (DE) in order to generate experimental models of the factor-response relationships. Within the design region, the DE and COMSOL models agreed in their recommended optimal nHA (30%) and strand diameter (460 μm). However, the two methods disagreed by more than 30% in strand spacing (908 μm for DE; 601 μm for COMSOL). Seven scaffolds were 3D-bioplotted to validate the predictions of DE and COMSOL models (4.5-9.9 MPa measured moduli). The predictions for these scaffolds showed relative agreement for scaffold porosity (mean absolute percentage error of 4% for DE and 13% for COMSOL), but were substantially poorer for scaffold modulus (51% for DE; 21% for COMSOL), partly due to some simplifying assumptions made by the models. Expanding the design region in future experiments (e.g., higher nHA content and strand diameter), developing an efficient solvent evaporation method, and exerting a greater control over layer overlap could allow developing PLGA-nHA-collagen scaffolds to meet the mechanical requirements for

  5. Presence of interleukin-4-producing cells for human bone regeneration after application of guided tissue regeneration membranes.

    Science.gov (United States)

    Kabashima, H; Nagata, K

    2001-07-01

    To study the process of bone regeneration we examined three samples of periapical regenerative tissue obtained from two patients under a guided tissue regeneration treatment in endodontic surgery by the immunohistochemical and enzyme histochemical methods. The regenerative tissue consisted of a large number of fibroblast-like cells and a small number of mononuclear cells. Fibroblast-like cells stained positively for alkaline phosphatase and osteopontin, whereas mononuclear cells stained positively for CD4. Interleukin-4-producing cells could be detected in adjacent sections. However, interferon-y-producing cells could not be detected. These findings suggest that interleukin-4-producing cells may be one of the elements associated with success in the human bone regeneration process in vivo.

  6. Fabrication of 13-93 bioactive glass scaffolds for bone tissue engineering using indirect selective laser sintering

    Energy Technology Data Exchange (ETDEWEB)

    Kolan, Krishna C R; Leu, Ming C [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO (United States); Hilmas, Gregory E [Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO (United States); Brown, Roger F [Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO (United States); Velez, Mariano, E-mail: kkd7b@mail.mst.edu, E-mail: mleu@mst.edu [Mo-Sci Corporation, Rolla, MO (United States)

    2011-06-15

    Bioactive glasses are promising materials for bone scaffolds due to their ability to assist in tissue regeneration. When implanted in vivo, bioactive glasses can convert into hydroxyapatite, the main mineral constituent of human bone, and form a strong bond with the surrounding tissues, thus providing an advantage over polymer scaffold materials. Bone scaffold fabrication using additive manufacturing techniques can provide control over pore interconnectivity during fabrication of the scaffold, which helps in mimicking human trabecular bone. 13-93 glass, a third-generation bioactive material designed to accelerate the body's natural ability to heal itself, was used in the research described herein to fabricate bone scaffolds using the selective laser sintering (SLS) process. 13-93 glass mixed with stearic acid (as the polymer binder) by ball milling was used as the powder feedstock for the SLS machine. The fabricated green scaffolds underwent binder burnout to remove the stearic acid binder and were then sintered at temperatures between 675 deg. C and 695 deg. C. The sintered scaffolds had pore sizes ranging from 300 to 800 {mu}m with 50% apparent porosity and an average compressive strength of 20.4 MPa, which is excellent for non-load bearing applications and among the highest reported for an interconnected porous scaffold fabricated with bioactive glasses using the SLS process. The MTT labeling experiment and measurements of MTT formazan formation are evidence that the rough surface of SLS scaffolds provides a cell-friendly surface capable of supporting robust cell growth.

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

    OpenAIRE

    Ohtsuki, Chikara; Kamitakahara, Masanobu; Miyazaki, Toshiki

    2009-01-01

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

  8. Association between traumatic bone marrow abnormalities of the knee, the trauma mechanism and associated soft-tissue knee injuries

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Nicole [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Department of Forensic Medicine and Radiology, Institute of Forensic Medicine, Zurich (Switzerland); Andreisek, Gustav; Karer, Anissja T.; Manoliu, Andrei; Ulbrich, Erika J. [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Bouaicha, Samy [University Hospital Zurich, Department of Trauma Surgery, Zurich (Switzerland); Naraghi, Ali [University of Toronto, Department of Medical Imaging, Mount Sinai Hospital and the University Health Network, Toronto, ON (Canada); Seifert, Burkhardt [University of Zurich, Epidemiology, Biostatistics and Prevention Institute, Department of Biostatistics, Zurich (Switzerland)

    2017-01-15

    To determine the association between traumatic bone marrow abnormalities, the knee injury mechanism, and associated soft tissue injuries in a larger cohort than those in the published literature. Retrospective study including 220 patients with traumatic knee injuries. Knee MRIs were evaluated for trauma mechanism, soft tissue injury, and the location of bone marrow abnormalities. The locations of the abnormalities were correlated with trauma mechanisms and soft tissue injuries using the chi-square test with Bonferroni correction. One hundred and forty-four valgus injuries, 39 pivot shift injuries, 25 lateral patellar dislocations, 8 hyperextensions, and 4 dashboard injuries were included. Valgus and pivot shift injuries showed traumatic bone marrow abnormalities in the posterolateral regions of the tibia. Abnormalities after patellar dislocation were found in the anterolateral and centrolateral femur and patella. Hyperextension injuries were associated with abnormalities in almost all regions, and dashboard injuries were associated with changes in the anterior regions of the tibia and femur. Our study provides evidence of associations between traumatic bone marrow abnormality patterns and different trauma mechanisms in acute knee injury, and reveals some overlap, especially of the two most common trauma mechanisms (valgus and pivot shift), in a large patient cohort. (orig.)

  9. Development of a new carbon nanotube–alginate–hydroxyapatite tricomponent composite scaffold for application in bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Rajesh R

    2015-10-01

    Full Text Available Rajendiran Rajesh, Y Dominic Ravichandran Organic Chemistry Division, School of Advanced Sciences, VIT University, Vellore, India Abstract: In recent times, tricomponent scaffolds prepared from naturally occurring polysaccharides, hydroxyapatite, and reinforcing materials have been gaining increased attention in the field of bone tissue engineering. In the current work, a tricomponent scaffold with an oxidized multiwalled carbon nanotube (fMWCNT–alginate–hydroxyapatite with the required porosity was prepared for the first time by a freeze-drying method and characterized using analytical techniques. The hydroxyapatite for the scaffold was isolated from chicken bones by thermal calcination at 800°C. The Fourier transform infrared spectra and X-ray diffraction data confirmed ionic interactions and formation of the fMWCNT–alginate–hydroxyapatite scaffold. Interconnected porosity with a pore size of 130–170 µm was evident from field emission scanning electron microscopy. The total porosity calculated using the liquid displacement method was found to be 93.85%. In vitro biocompatibility and cell proliferation on the scaffold was checked using an MG-63 cell line by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay and cell attachment by Hoechst stain assay. In vitro studies showed better cell proliferation, cell differentiation, and cell attachment on the prepared scaffold. These results indicate that this scaffold could be a promising candidate for bone tissue engineering. Keywords: chicken bone, hydroxyapatite, alginate, tissue engineering

  10. Neutron activation analysis in the central nervous system tissues and bones of rats maintained on minerally unbalanced diets

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Masayuki; Ota, Kiichiro [Wakayama Medical Coll. (Japan); Sasajima, Kazuhisa

    1994-07-01

    It is presumed that by the shortage of Mg, Zn and Ca, functional or organic diseases may occur. When Al deposits to central nervous tissues and bones, various diseases are induced. As the degeneracy of central nervous system, in which minerals are presumed to take part, amyotrophic lateral sclerosis, Parkinsonism dementia, Alzheimer disease and Parkinson`s disease are enumerated. Four groups of Winstar rats were bred for 90 days with standard diet, low Ca diet, low Ca and Mg diet and low Ca and Mg, high Al diet, and the contents of Mg, Ca and Zn in the tissues of various parts were analyzed by plasma luminescence analysis, and the content of Al was analyzed by activation analysis. The results for blood serum, bones, soft tissues and the correlation of respective minerals in thighbones and lumbars are reported. It was presumed that the adjustment of the mineralization of bones was disturbed by low Ca and Mg diet, and consequently, also the adjustment of Al, Mn, Zn and other elements caused failure in living bodies. It is considered that as the adjustment of the mineralization of bones was disturbed, the deposit of Al in living bodies was increased. The possibility of preventing Al deposit can be expected by the rational adjustment of mineral metabolism. (K.I.).

  11. Comparison of molecular profiles of human mesenchymal stem cells derived from bone marrow, umbilical cord blood, placenta and adipose tissue.

    Science.gov (United States)

    Heo, June Seok; Choi, Youjeong; Kim, Han-Soo; Kim, Hyun Ok

    2016-01-01

    Mesenchymal stem cells (MSCs) are clinically useful due to their capacity for self-renewal, their immunomodulatory properties and tissue regenerative potential. These cells can be isolated from various tissues and exhibit different potential for clinical applications according to their origin, and thus comparative studies on MSCs from different tissues are essential. In this study, we investigated the immunophenotype, proliferative potential, multilineage differentiation and immunomodulatory capacity of MSCs derived from different tissue sources, namely bone marrow, adipose tissue, the placenta and umbilical cord blood. The gene expression profiles of stemness-related genes [octamer-binding transcription factor 4 (OCT4), sex determining region Y-box (SOX)2, MYC, Krüppel-like factor 4 (KLF4), NANOG, LIN28 and REX1] and lineage‑related and differentiation stage-related genes [B4GALNT1 (GM2/GS2 synthase), inhibin, beta A (INHBA), distal-less homeobox 5 (DLX5), runt-related transcription factor 2 (RUNX2), proliferator‑activated receptor gamma (PPARG), CCAAT/enhancer-binding protein alpha (C/EBPA), bone morphogenetic protein 7 (BMP7) and SOX9] were compared using RT-PCR. No significant differences in growth rate, colony-forming efficiency and immunophenotype were observed. Our results demonstrated that MSCs derived from bone marrow and adipose tissue shared not only in vitro tri-lineage differentiation potential, but also gene expression profiles. While there was considerable inter-donor variation in DLX5 expression between MSCs derived from different tissues, its expression appears to be associated with the osteogenic potential of MSCs. Bone marrow-derived MSCs (BM-MSCs) significantly inhibited allogeneic T cell proliferation possibly via the high levels of the immunosuppressive cytokines, IL10 and TGFB1. Although MSCs derived from different tissues and fibroblasts share many characteristics, some of the marker genes, such as B4GALNT1 and DLX5 may be useful for

  12. Bone Response to Surface-Modified Titanium Implants: Studies on the Early Tissue Response to Implants with Different Surface Characteristics

    Directory of Open Access Journals (Sweden)

    C. Larsson Wexell

    2013-01-01

    Full Text Available In a series of experimental studies, the bone formation around systematically modified titanium implants is analyzed. In the present study, three different surface modifications were prepared and evaluated. Glow-discharge cleaning and oxidizing resulted in a highly stoichiometric TiO2 surface, while a glow-discharge treatment in nitrogen gas resulted in implants with essentially a surface of titanium nitride, covered with a very thin titanium oxide. Finally, hydrogen peroxide treatment of implants resulted in an almost stoichiometric TiO2, rich in hydroxyl groups on the surface. Machined commercially pure titanium implants served as controls. Scanning Auger Electron Spectroscopy, Scanning Electron Microscopy, and Atomic Force Microscopy revealed no significant differences in oxide thickness or surface roughness parameters, but differences in the surface chemical composition and apparent topography were observed. After surface preparation, the implants were inserted in cortical bone of rabbits and evaluated after 1, 3, and 6 weeks. Light microscopic evaluation of the tissue response showed that all implants were in contact with bone and had a large proportion of newly formed bone within the threads after 6 weeks. There were no morphological differences between the four groups. Our study shows that a high degree of bone contact and bone formation can be achieved with titanium implants of different surface composition and topography.

  13. Analysis on Application Bottleneck of Repairing Bone Defects with Tissue Engineered Bone%组织工程骨修复骨缺损的应用瓶颈分析

    Institute of Scientific and Technical Information of China (English)

    李凯

    2012-01-01

    Bone defects caused by bone cancer treatment are common in clinical, however the only way to repair the defects is bone graft. According to sources, the bone graft material can be divided into autogenous bone, allograft bone ,xenograft bone and artificial bone substitute materials. The rise of bone tissue engineering brings new options for the treatment of bone defects. The use of artificial bone tissue engineering training not only fixes the large area of bone defect, but also can be prepared and shaped in large quantity according to need,which makes it an ideal bone repair material. Here is to make a review' on the application status of tissue engineered bone in the treatment of bone defects.%骨肿瘤的治疗导致骨缺损很常见,修复缺损的方法是采取骨移植.骨移植材料根据来源大致可分为自体骨、同种异体骨、异种骨和人工骨替代材料.骨组织工程的兴起为骨缺损的治疗带来新的选择.利用骨组织工程培养的人工骨不仅可以修复大面积骨缺损,而且可以按需塑形并大量制备,是一种理想的骨修复材料.现就组织工程骨在治疗骨缺损中的应用现状进行综述.

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

    DEFF Research Database (Denmark)

    Kirkeby, S; Vilmann, H

    1981-01-01

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

  15. The application of bone morphogenetic proteins to periodontal and peri-implant tissue regeneration: A literature review

    Directory of Open Access Journals (Sweden)

    Karuppanan P Sasikumar

    2012-01-01

    Full Text Available Progress in understanding the role of bone morphogenetic proteins (BMPs in craniofacial and tooth development and the demonstration of stem cells in periodontal ligament have set the stage for periodontal regenerative therapy and tissue engineering. Furthermore, recent approval by the Food and Drug Administration of recombinant human BMPs for accelerating bone fusion in slow-healing fractures indicates that this protein family may prove useful in designing regenerative treatments in periodontics. In the near term, these advances are likely to be applied to periodontal surgery; ultimately, they may facilitate approaches to regenerating whole lost periodontal structures.

  16. Final Report for completed IPP Project:"Development of Plasma Ablation for Soft Tissue and Bone Surgery"

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Ian

    2009-09-01

    ArthroCare is a medical device company that develops, manufactures, and markets an advanced surgical tool, a plasma electro-surgical system for cutting and removing tissue. The hand-held electrical discharge device produces plasma in a biocompatible conductive fluid and tissue to which it is applied during surgery. Its products allow surgeons to operate with increased precision and accuracy, limiting damage to surrounding tissue thereby reducing pain and speeding recovery for the patient. In the past, the design of ArthfoCare's plasma wands has been an empirical undertaking. One goal of this R&D program was to put the phenomena involved on a sound scientific footing, allowing optimization of existing plasma based electro-surgery system technology, and the design and manufacture of new and improved kinds of scalpels, in particular for the surgical cutting of bone. Another important related goal of the program was to develop, through an experimental approach, new plasma wand approaches to the cutting ('shaving') of hard bone tissue. The goals of the CRADA were accomplished - computer models were used to predict important parameters of the plasma discharge and the bone environment, and several different approaches to bone-shaving were developed and demonstrated. The primary goal of the project was to develop and demonstrate an atmospheric-pressure plasma tool that is suitable for surgical use for shaving bone in humans. This goal was accomplished, in fact with several different alternative plasma approaches. High bone ablation speeds were measured. The use of probes ('plasma wand' - the surgical tool) with moving active electrodes was also explored, and there are advantages to this method. Another important feature is that the newly-exposed bone surface have only a very thin necrosis layer; this feature was demonstrated. This CRADA has greatly advanced our understanding of bone removal by atmospheric pressure plasmas in liquid, and puts Arthro

  17. Maxillary sinus floor elevation using a tissue-engineered bone with calcium-magnesium phosphate cement and bone marrow stromal cells in rabbits.

    Science.gov (United States)

    Zeng, Deliang; Xia, Lunguo; Zhang, Wenjie; Huang, Hui; Wei, Bin; Huang, Qingfeng; Wei, Jie; Liu, Changsheng; Jiang, Xinquan

    2012-04-01

    The objective of this study was to assess the effects of maxillary sinus floor elevation with a tissue-engineered bone constructed with bone marrow stromal cells (bMSCs) and calcium-magnesium phosphate cement (CMPC) material. The calcium (Ca), magnesium (Mg), and phosphorus (P) ions released from calcium phosphate cement (CPC), magnesium phosphate cement (MPC), and CMPC were detected by inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the proliferation and osteogenic differentiation of bMSCs seeded on CPC, MPC, and CMPC or cultured in CPC, MPC, and CMPC extracts were measured by MTT analysis, alkaline phosphatase (ALP) activity assay, alizarin red mineralization assay, and real-time PCR analysis of the osteogenic genes ALP and osteocalcin (OCN). Finally, bMSCs were combined with CPC, MPC, and CMPC and used for maxillary sinus floor elevation in rabbits, while CPC, MPC, or CMPC without cells served as control groups. The new bone formation in each group was detected by histological finding and fluorochrome labeling at weeks 2 and 8 after surgical operation. It was observed that the Ca ion concentrations of the CMPC and CPC scaffolds was significantly higher than that of the MPC scaffold, while the Mg ions concentration of CMPC and MPC was significantly higher than that of CPC. The bMSCs seeded on CMPC and MPC or cultured in their extracts proliferated more quickly than the cells seeded on CPC or cultured in its extract, respectively. The osteogenic differentiation of bMSCs seeded on CMPC and CPC or cultured in the corresponding extracts was significantly enhanced compared to that of bMSCs seeded on MPC or cultured in its extract; however, there was no significant difference between CMPC and CPC. As for maxillary sinus floor elevation in vivo, CMPC could promote more new bone formation and mineralization compared to CPC and MPC, while the addition of bMSCs could further enhance its new bone formation ability significantly. Our data suggest that

  18. Synthesis and characterization of a novel chitosan/montmorillonite/hydroxyapatite nanocomposite for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Katti, Kalpana S; Katti, Dinesh R; Dash, Rajalaxmi [Department of Civil Engineering, North Dakota State University, Fargo, ND 58105 (United States)], E-mail: Kalpana.katti@ndsu.edu

    2008-09-01

    Recently, biopolymer-based nanocomposites have been replacing synthetic polymer composites for various biomedical applications. This is often because of the biocompatible and biodegradable behavior of natural polymers. Several studies have been reported pertaining to the synthesis and characterization of chitosan(chi)/montmorillonite(MMT) and chitosan (chi)/hydroxyapatite (HAP) for tissue engineering applications. In the present work, a biopolymer-based novel nanocomposite chitosan/montmorillonite (MMT)/hydroxyapatite (HAP) was developed for biomedical applications. The composite was prepared from chitosan, unmodified MMT and HAP precipitate in aqueous media. The properties of the composites were investigated using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). Nanomechanical properties were measured using nanoindentation. Cell culture experiments were also conducted in order to ascertain the biocompatibility of the composite. The XRD results indicate that an intercalated structure was formed with an increase in d-spacing of montmorillonite. FTIR studies provide the evidence of molecular interaction among the three different constituents of the composite. AFM images show well-distributed nanoparticles in the chitosan matrix. The composites also exhibit a significant enhancement in nanomechanical property as compared to pure chitosan as well as the chi/HAP and chi/MMT composites. The TGA results indicate that an intercalated nanocomposite was formed with improved thermal properties even compared to chi/MMT composites. The results of cell culture experiments show that the composite is biocompatible and has a better cell proliferation rate compared to chi/HAP composites. This work represents the design of a novel clay-chitosan-hydroxyapatite composite with improved mechanical properties that has potential applications in bone tissue engineering.

  19. Correlation of fat embolism severity and subcutaneous fatty tissue crushing and bone fractures.

    Science.gov (United States)

    Bolliger, Stephan Andreas; Muehlematter, Karin; Thali, Michael Josef; Ampanozi, Garyfalia

    2011-05-01

    Pulmonary fat embolism (PFE) is frequently encountered in blunt trauma. The clinical manifestation ranges from no impairment in light cases to death due to right-sided heart failure or hypoxaemia in severe cases. Occasionally, pulmonary fat embolism can give rise to a fat embolism syndrome (FES), which is marked by multiorgan failure, respiratory disorders, petechiae and often death. It is well known that fractures of long bones can lead to PFE. Several authors have argued that PFE can arise due to mere soft tissue injury in the absence of fractures, a claim other authors disagree upon. In this study, we retrospectively examined 50 victims of blunt trauma with regard to grade and extent of fractures and crushing of subcutaneous fatty tissue and presence and severity of PFE. Our results indicate that PFE can arise due to mere crushing of subcutaneous fat and that the fracture grade correlated well with PFE severity (p = 0.011). The correlation between PFE and the fracture severity (body regions affected by fractures and fracture grade) showed a lesser significant correlation (p = 0.170). The survival time (p = 0.567), the amount of body regions affected by fat crushing (p = 0.336) and the fat crush grade (p = 0.485) did not correlate with the PFE grade, nor did the amount of body regions affected by fractures. These results may have clinical implications for the assessment of a possible FES development, as, if the risk of a PFE is known, preventive steps can be taken.

  20. Multilayer bioactive glass/zirconium titanate thin films in bone tissue engineering and regenerative dentistry

    D