WorldWideScience

Sample records for adhesion molecule-modified biomaterials

  1. Staphylococcus epidermidis adhesion on hydrophobic and hydrophilic textured biomaterial surfaces

    It is of great interest to use nano- or micro-structured surfaces to inhibit microbial adhesion and biofilm formation and thereby to prevent biomaterial-associated infection, without modification of the surface chemistry or bulk properties of the materials and without use of the drugs. Our previous study showed that a submicron textured polyurethane surface can inhibit staphylococcal bacterial adhesion and biofilm formation. To further understand the effect of the geometry of textures on bacterial adhesion as well as the underlying mechanism, in this study, submicron and micron textured polyurethane surfaces featuring ordered arrays of pillars were fabricated and modified to have different wettabilities. All the textured surfaces were originally hydrophobic and showed significant reductions in Staphylococcus epidermidis RP62A adhesion in phosphate buffered saline or 25% platelet poor plasma solutions under shear, as compared to smooth surfaces. After being subjected to an air glow discharge plasma treatment, all polyurethane surfaces were modified to hydrophilic, and reductions in bacterial adhesion on surfaces were subsequently found to be dependent on the size of the patterns. The submicron patterned surfaces reduced bacterial adhesion, while the micron patterned surfaces led to increased bacterial adhesion. The extracellular polymeric substances (EPS) from the S. epidermidis cell surfaces were extracted and purified, and were coated on a glass colloidal surface so that the adhesion force and separation energy in interactions of the EPS and the surface could be measured by colloidal probe atomic force microscopy. These results were consistent with the bacterial adhesion observations. Overall, the data suggest that the increased surface hydrophobicity and the decreased availability of the contact area contributes to a reduction in bacterial adhesion to the hydrophobic textured surfaces, while the availability of the contact area is the primary determinant factor

  2. Oral bacterial adhesion forces to biomaterial surfaces constituting the bracket-adhesive-enamel junction in orthodontic treatment

    Mei, Li; Busscher, Henk J; van der Mei, Henny C; Chen, Yangxi; de Vries, Joop; Ren, Yijin

    2009-01-01

    Bacterial adhesion to biomaterial surfaces constituting the bracket-adhesive-enamel junction represents a growing problem in orthodontics, because bacteria can adversely affect treatment by causing demineralization of the enamel surface around the brackets. It is important to know the forces with wh

  3. Biomaterials

    Van Mourik, P.; Van Dam, J.; Picken, S.J.; Ursem, B.

    2013-01-01

    The metabolic pathways of living organisms produce biomaterials. Hence, in principle biomaterials are fully sustainable. This does not mean that their processing and application have no impact on the environment, e.g. the recycling of natural rubber remains a problem. Biomaterials are applied in a w

  4. Biomaterials

    Migonney , Véronique

    2014-01-01

    Discovered in the 20th century, biomaterials have contributed to many of the incredible scientific and technological advancements made in recent decades. This book introduces and details the tenets of biomaterials, their relevance in a various fields, practical applications of their products, and potential advancements of the years to come. A comprehensive resource, the text covers the reasons that certain properties of biomaterials contribute to specific applications, and students and researchers will appreciate this exhaustive textbook.

  5. Biomaterials

    Van Mourik, P; van Dam, J; Picken, S.J.; Ursem, B.

    2013-01-01

    The metabolic pathways of living organisms produce biomaterials. Hence, in principle biomaterials are fully sustainable. This does not mean that their processing and application have no impact on the environment, e.g. the recycling of natural rubber remains a problem. Biomaterials are applied in a wide range of consumer products, varying from clothing via temporary packaging materials to car parts. Examples are the paper we print on, the wooden table we sit around and the jeans we wear. This ...

  6. Extracellular matrix-mimetic adhesive biomaterials for bone repair

    Shekaran, Asha; Andrés J. García

    2010-01-01

    Limited osseointegration of current orthopaedic biomaterials contributes to the failure of implants such as arthroplasties, bone screws and bone grafts, which present a large socioeconomic cost within the United States. These implant failures underscore the need for biomimetic approaches that modulate host cell-implant material responses to enhance implant osseointegration and bone formation. Bioinspired strategies have included functionalizing implants with ECM proteins or ECM-derived peptid...

  7. Biomaterial based novel polyurethane adhesives for wood to wood and metal to metal bonding

    Mitesh Ramanlal Patel

    2009-01-01

    Full Text Available Polyurethane adhesives made from synthetic chemicals are non-biodegradable, costly and difficult to find raw materials from local market. To avoid solid pollution problem, cost effectiveness and easy availability of raw materials, biomaterials based polyurethane adhesives are used in current industrial interest. Direct use of castor oil in polyurethane adhesive gives limited hardness. Modification on active sites of castor oil to utilize double bond of unsaturated fatty acid and carboxyl group yields new modified or activated polyols, which can be utilized for polyurethane adhesive formulation. In view of this, we have synthesized polyurethane adhesives from polyester polyols, castor oil based polyols and epoxy based polyols with Isocyanate adducts based on castor oil and trimethylolpropane. To study the effects of polyurethane adhesive strength (i.e. lap shear strength on wood-to-wood and metal-to-metal bonding through various types of polyols, cross-linking density, isocyanate adducts and also to compare adhesive strength between wood to wood and metal to metal surface. These polyols and polyurethanes were characterized through GPC, NMR and IR-spectroscopy, gel and surface drying time. Thermal stability of PU adhesives was determined under the effect of cross-linking density (NCO/OH ratio. The NCO/OH ratio (1.5 was optimized for adhesives as the higher NCO/OH ratio (2.0 increasing cross-linking density and decreases adhesion. Lower NCO/OH ratio (1.0 provideslow cross-linking density and low strength of adhesives.

  8. Concise review of mechanisms of bacterial adhesion to biomaterials and of techniques used in estimating bacteria-material interactions

    Katsikogianni M.

    2004-12-01

    Full Text Available This article reviews the mechanisms of bacterial adhesion to biomaterial surfaces, the factors affecting the adhesion, the techniques used in estimating bacteria-material interactions and the models that have been developed in order to predict adhesion. The process of bacterial adhesion includes an initial physicochemical interaction phase and a late molecular and cellular one. It is a complicated process influenced by many factors, including the bacterial properties, the material surface characteristics, the environmental factors, such as the presence of serum proteins and the associated flow conditions. Two categories of techniques used in estimating bacteria-material interactions are described: those that utilize fluid flowing against the adhered bacteria and counting the percentage of bacteria that detach, and those that manipulate single bacteria in various configurations which lend themselves to more specific force application and provide the basis for theoretical analysis of the receptor-ligand interactions. The theories that are reviewed are the Derjaguin-Landau-Verwey-Overbeek (DLVO theory, the thermodynamic approach and the extended DLVO theory. Over the years, significant work has been done to investigate the process of bacterial adhesion to biomaterial surfaces, however a lot of questions still remain unanswered.

  9. Insight on stem cell preconditioning and instructive biomaterials to enhance cell adhesion, retention, and engraftment for tissue repair.

    Shafiq, Muhammad; Jung, Youngmee; Kim, Soo Hyun

    2016-06-01

    Stem cells are a promising solution for the treatment of a variety of diseases. However, the limited survival and engraftment of transplanted cells due to a hostile ischemic environment is a bottleneck for effective utilization and commercialization. Within this environment, the majority of transplanted cells undergo apoptosis prior to participating in lineage differentiation and cellular integration. Therefore, in order to maximize the clinical utility of stem/progenitor cells, strategies must be employed to increase their adhesion, retention, and engraftment in vivo. Here, we reviewed key strategies that are being adopted to enhance the survival, retention, and engraftment of transplanted stem cells through the manipulation of both the stem cells and the surrounding environment. We describe how preconditioning of cells or cell manipulations strategies can enhance stem cell survival and engraftment after transplantation. We also discuss how biomaterials can enhance the function of stem cells for effective tissue regeneration. Biomaterials can incorporate or mimic extracellular function (ECM) function and enhance survival or differentiation of transplanted cells in vivo. Biomaterials can also promote angiogenesis, enhance engraftment and differentiation, and accelerate electromechanical integration of transplanted stem cells. Insight gained from this review may direct the development of future investigations and clinical trials. PMID:27016619

  10. UV- Killed Staphylococcus aureus Enhances Adhesion and Differentiation of Osteoblasts on Bone-associated Biomaterials

    Somayaji, Shankari N.; Huet, Yvette M.; Gruber, Helen E.; Hudson, Michael C

    2010-01-01

    Titanium alloys (Ti) are the preferred material for orthopaedic applications. However, very often, these metallic implants loosen over a long period and mandate revision surgery. For implant success, osteoblasts must adhere to the implant surface and deposit a mineralized extracellular matrix. Here, we utilized UV-killed Staphylococcus aureus as a novel osteoconductive coating for Ti surfaces. S. aureus expresses surface adhesins capable of binding to bone and biomaterials directly. Furthermo...

  11. Adhesion of resin composites to biomaterials in dentistry: an evaluation of surface conditioning methods

    Özcan, Mutlu

    2003-01-01

    Since previous investigations revealed that most clinical failures in adhesively luted ceramic restorations initiate from the cementation or internal surfaces, the study presented in Chapter II evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA based luting cement to glass ceramics, glass infiltrated alumina, glass infiltrated ZrO2 reinforced alumina. The three conditioning methods assesed were: (1) HF acid etching, (2) Air-borne particle ab...

  12. Adhesión bacteriana a biomateriales Bacterial adhesion to biomaterials

    C Ábalos

    2005-02-01

    Full Text Available En términos generales, para la adhesión bacteriana, influyen cuatro elementos: Material, Microorganismos, antimicrobianos y mecanismos de defensa. La influencia del material es más importante en los estadios iniciales de la adhesión, pudiendo influir el mismo material, su rugosidad o su energía superficial., si es que existe una influencia del material en la adhesión bacteriana, esta reside en las caracteristicas de la película adquirida y en la especificidad de las proteinas adsorbidas salivares (receptores, que puedan ser condicionadas por la composición del material o por las características de superficie de este.In general terms, there are four elements which influence on bacterial adhesion: the material, the micro organisms, antimicrobials and defence mechanisms. The influence of the material is more relevant at the initial states of adhesion where the proper material, its roughness or its superficial energy can have some influence. If there is some influence of the material in the bacterial adhesion, it relies on the features of the acquired film and on the specificity of the adsorved salivary proteins (receptors, which can be influenced by the composition of the material or the characteristics of its surface.

  13. Zirconia as a Dental Biomaterial

    Alvaro Della Bona; Pecho, Oscar E.; Rodrigo Alessandretti

    2015-01-01

    Ceramics are very important in the science of dental biomaterials. Among all dental ceramics, zirconia is in evidence as a dental biomaterial and it is the material of choice in contemporary restorative dentistry. Zirconia has been applied as structural material for dental bridges, crowns, inserts, and implants, mostly because of its biocompatibility, high fracture toughness, and radiopacity. However, the clinical success of restorative dentistry has to consider the adhesion to different subs...

  14. Supramolecular biomaterials

    Webber, Matthew J.; Appel, Eric A.; Meijer, E. W.; Langer, Robert

    2016-01-01

    Polymers, ceramics and metals have historically dominated the application of materials in medicine. Yet rationally designed materials that exploit specific, directional, tunable and reversible non-covalent interactions offer unprecedented advantages: they enable modular and generalizable platforms with tunable mechanical, chemical and biological properties. Indeed, the reversible nature of supramolecular interactions gives rise to biomaterials that can sense and respond to physiological cues, or that mimic the structural and functional aspects of biological signalling. In this Review, we discuss the properties of several supramolecular biomaterials, as well as their applications in drug delivery, tissue engineering, regenerative medicine and immunology. We envision that supramolecular biomaterials will contribute to the development of new therapies that combine highly functional materials with unmatched patient- and application-specific tailoring of both material and biological properties.

  15. Bacterial adhesion to titanium-oxy-nitride (TiNOX) coatings with different resistivities : a novel approach for the development of biomaterials

    Koerner, RJ; Butterworth, LA; Mayer, [No Value; Dasbach, R; Busscher, HJ

    2002-01-01

    In this study the quantitative adhesion of a strain of Staphylococcus epidermidis, Streptococcus mutans and Pseudomonas aeruginosa to and the ease of removal from different TiNOX coatings was investigated by means of a parallel plate flow chamber and in situ image analysis. Quality of adhesion was d

  16. Biological biomaterials

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  17. Current Strategies in Cardiovascular Biomaterial Functionalization

    Karla Lehle

    2010-01-01

    Full Text Available Prevention of the coagulation cascade and platelet activation is the foremost demand for biomaterials in contact with blood. In this review we describe the underlying mechanisms of these processes and offer the current state of antithrombotic strategies. We give an overview of methods to prevent protein and platelet adhesion, as well as techniques to immobilize biochemically active molecules on biomaterial surfaces. Finally, recent strategies in biofunctionalization by endothelial cell seeding as well as their possible clinical applications are discussed.

  18. Modulating macrophage response to biomaterials

    Zaveri, Toral

    Macrophages recruited to the site of biomaterial implantation are the primary mediators of the chronic foreign body response to implanted materials. Since foreign body response limits performance and functional life of numerous implanted biomaterials/medical devices, various approaches have been investigated to modulate macrophage interactions with biomaterial surfaces to mitigate this response. In this work we have explored two independent approaches to modulate the macrophage inflammatory response to biomaterials. The first approach targets surface integrins, cell surface receptors that mediate cell adhesion to biomaterials through adhesive proteins spontaneously adsorbed on biomaterial surfaces. The second approach involves surface modification of biomaterials using nanotopographic features since nanotopography has been reported to modulate cell adhesion and viability in a cell type-dependent manner. More specifically, Zinc Oxide (ZnO) nanorod surface was investigated for its role in modulating macrophage adhesion and survival in vitro and foreign body response in vivo. For the first approach, we have investigated the role of integrin Mac-1 and RGD-binding integrins in the in-vivo osteolysis response and macrophage inflammatory processes of phagocytosis as well as inflammatory cytokine secretion in response to particulate biomaterials. We have also investigated the in vivo foreign body response (FBR) to subcutaneously implanted biomaterials by evaluating the thickness of fibrous capsule formed around the implants after 2 weeks of implantation. The role of Mac-1 integrin was isolated using a Mac-1 KO mouse and comparing it to a WT control. The role of RGD binding integrins in FBR was investigated by coating the implanted biomaterial with ELVAX(TM) polymer loaded with Echistatin which contains the RGD sequence. For the in-vivo osteolysis study and to study the in-vitro macrophage response to particulate biomaterials, we used the RGD peptide encapsulated in ELVAX

  19. Studies on biodegradable and crosslinkable poly(castor oil fumarate)/poly(propylene fumarate) composite adhesive as a potential injectable biomaterial.

    Mitha, M K; Jayabalan, M

    2009-12-01

    Biodegradable hydroxyl terminated-poly(castor oil fumarate) (HT-PCF) and poly(propylene fumarate) (HT-PPF) resins were synthesized as an injectable and in situ-cross linkable polyester resins for orthopedic applications. An injectable adhesive formulation containing this resin blend, N-vinyl pyrrolidone (NVP), hydroxy apatite, free radical initiator and accelerator was developed. The Composite adhesives containing the ratio of resin blend and NVP, 2.1:1.5, 2.1:1.2 and 2.1:1.0 set fast with tolerable exothermic temperature as a three dimensionally cross linked toughened material. Crosslink density and mechanical properties of the crosslinked composite increase with increase of NVP. The present crosslinked composite has hydrophilic character and cytocompatibility with L929 fibroblast cells. PMID:18592346

  20. Electrical activity of ferroelectric biomaterials and its effects on the adhesion, growth and enzymatic activity of human osteoblast-like cells

    Vaněk, P.; Kolská, Z.; Luxbacher, T.; García, J. A. L.; Lehocký, M.; Vandrovcová, M.; Bačáková, L.; Petzelt, J.

    2016-05-01

    Ferroelectrics have been, among others, studied as electroactive implant materials. Previous investigations have indicated that such implants induce improved bone formation. If a ferroelectric is immersed in a liquid, an electric double layer and a diffusion layer are formed at the interface. This is decisive for protein adsorption and bioactive behaviour, particularly for the adhesion and growth of cells. The charge distribution can be characterized, in a simplified way, by the zeta potential. We measured the zeta potential in dependence on the surface polarity on poled ferroelectric single crystalline LiNbO3 plates. Both our results and recent results of colloidal probe microscopy indicate that the charge distribution at the surface can be influenced by the surface polarity of ferroelectrics under certain ‘ideal’ conditions (low ionic strength, non-contaminated surface, very low roughness). However, suggested ferroelectric coatings on the surface of implants are far from ideal: they are rough, polycrystalline, and the body fluid is complex and has high ionic strength. In real cases, it can therefore be expected that there is rather low influence of the sign of the surface polarity on the electric diffusion layer and thus on the specific adsorption of proteins. This is supported by our results from studies of the adhesion, growth and the activity of alkaline phosphatase of human osteoblast-like Saos-2 cells on ferroelectric LiNbO3 plates in vitro.

  1. Characterization of Bone Marrow Mononuclear Cells on Biomaterials for Bone Tissue Engineering In Vitro

    Dirk Henrich; René Verboket; Alexander Schaible; Kerstin Kontradowitz; Elsie Oppermann; Brune, Jan C; Christoph Nau; Simon Meier; Halvard Bonig; Ingo Marzi; Caroline Seebach

    2015-01-01

    Bone marrow mononuclear cells (BMCs) are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or ...

  2. Preparation of novel functional Mg/O/PCL/ZnO composite biomaterials and their corrosion resistance

    Highlights: • Novel functional Mg/O/PCL/ZnO composite biomaterials were prepared. • The biomaterials were prepared by anodization treatment and dip-coating technique. • The composite biomaterials were smooth and with low porosity. • The prepared biomaterials have good corrosion resistance in SBF. • The composite biomaterials can release zinc ion to promote bone formation. - Abstract: In this study, novel and functional Mg/O/PCL/ZnO (magnesium/anodic film/poly(ε-caprolactone)/zinc oxide) composite biomaterials for enhancing the bioactivity and biocompatibility of the implant was prepared by using anodization treatment and dip-coating technique. The surface morphology, microstructure, adhesion strength and corrosion resistance of the composite biomaterials were investigated using scanning electron microscopy (SEM), adhesion measurements, electrochemical tests and immersion tests respectively. In addition, the biocompatible properties of Mg (magnesium), Mg/PCL (magnesium/poly(ε-caprolactone)) and Mg/O/PCL (magnesium/anodic film/poly(ε-caprolactone)) samples were also investigated. The results show that the Mg/O/PCL/ZnO composite biomaterials were with low porosity and with the ZnO powders dispersed in PCL uniformly. The adhesion tests suggested that Mg/O/PCL/ZnO composite biomaterials had better adhesion strength than that of Mg/PCL composite biomaterials obviously. Besides, an in vitro test for corrosion demonstrated that the Mg/O/PCL/ZnO composite biomaterials had good corrosion resistance and zinc ion was released obviously in SBF

  3. Preparation of novel functional Mg/O/PCL/ZnO composite biomaterials and their corrosion resistance

    Xi, Zhongxian; Tan, Cui; Xu, Lan; Yang, Na; Li, Qing, E-mail: liqingdswu@163.com

    2015-10-01

    Highlights: • Novel functional Mg/O/PCL/ZnO composite biomaterials were prepared. • The biomaterials were prepared by anodization treatment and dip-coating technique. • The composite biomaterials were smooth and with low porosity. • The prepared biomaterials have good corrosion resistance in SBF. • The composite biomaterials can release zinc ion to promote bone formation. - Abstract: In this study, novel and functional Mg/O/PCL/ZnO (magnesium/anodic film/poly(ε-caprolactone)/zinc oxide) composite biomaterials for enhancing the bioactivity and biocompatibility of the implant was prepared by using anodization treatment and dip-coating technique. The surface morphology, microstructure, adhesion strength and corrosion resistance of the composite biomaterials were investigated using scanning electron microscopy (SEM), adhesion measurements, electrochemical tests and immersion tests respectively. In addition, the biocompatible properties of Mg (magnesium), Mg/PCL (magnesium/poly(ε-caprolactone)) and Mg/O/PCL (magnesium/anodic film/poly(ε-caprolactone)) samples were also investigated. The results show that the Mg/O/PCL/ZnO composite biomaterials were with low porosity and with the ZnO powders dispersed in PCL uniformly. The adhesion tests suggested that Mg/O/PCL/ZnO composite biomaterials had better adhesion strength than that of Mg/PCL composite biomaterials obviously. Besides, an in vitro test for corrosion demonstrated that the Mg/O/PCL/ZnO composite biomaterials had good corrosion resistance and zinc ion was released obviously in SBF.

  4. Antibacterial Efficiency of Hydroxyapatite Biomaterials with Biodegradable Polylactic Acid and Polycaprolactone Polymers Saturated with Antibiotics / Bionoārdāmu Polimēru Saturošu Un Ar Antibiotiskajām Vielām Piesūcinātu Biomateriālu Antibakteriālās Efektivitātes Noteikšana

    Kroiča Juta

    2016-08-01

    Full Text Available Infections continue to spread in all fields of medicine, and especially in the field of implant biomaterial surgery, and not only during the surgery, but also after surgery. Reducing the adhesion of bacteria could decrease the possibility of biomaterial-associated infections. Bacterial adhesion could be reduced by local antibiotic release from the biomaterial. In this in vitro study, hydroxyapatite biomaterials with antibiotics and biodegradable polymers were tested for their ability to reduce bacteria adhesion and biofilm development. This study examined the antibacterial efficiency of hydroxyapatite biomaterials with antibiotics and biodegradable polymers against Staphylococcus epidermidis and Pseudomonas aeruginosa. The study found that hydroxyapatite biomaterials with antibiotics and biodegradable polymers show longer antibacterial properties than hydroxyapatite biomaterials with antibiotics against both bacterial cultures. Therefore, the results of this study demonstrated that biomaterials that are coated with biodegradable polymers release antibiotics from biomaterial samples for a longer period of time and may be useful for reducing bacterial adhesion on orthopedic implants.

  5. Biomaterials for cardiac regeneration

    Ruel, Marc

    2015-01-01

    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  6. Voltammetry of Medical Biomaterials

    Gulaboski, Rubin; Markovski, Velo

    2015-01-01

    The use of biomaterials in the medicine, dentistry and pharmacy represents probably a major breakthrough in tackling many diseases or disabilities in the last 50 years. We refer to varios techniques that are used for the characterization of the structure and the composition of the biomaterials. Voltammetry is an electrochemical technique that helps mainly in understanding the redox properties of various biomaterials containing some suitable redox centers in their structure. We give in this le...

  7. Biofilm and Dental Biomaterials

    Marit Øilo; Vidar Bakken

    2015-01-01

    All treatment involving the use of biomaterials in the body can affect the host in positive or negative ways. The microbiological environment in the oral cavity is affected by the composition and shape of the biomaterials used for oral restorations. This may impair the patients’ oral health and sometimes their general health as well. Many factors determine the composition of the microbiota and the formation of biofilm in relation to biomaterials such as, surface roughness, surface energy and ...

  8. An introduction to biomaterials

    Hollinger, Jeffrey O

    2011-01-01

    Consensus Definitions, Fundamental Concepts, and a Standardized Approach to Applied Biomaterials Sciences, J.O. HollingerBiology, Biomechanics, Biomaterial Interactions: Wound Healing BiologyCutaneous Wound Pathobiology: Raison d'etre for Tissue Engineering, L.K. Macri and R.A.F. ClarkOsseous Wound Healing, A. Nawab, M. Wong, D. Kwak, L. Schutte, A. Sharma, and J.O. HollingerBiology, Biomechanics, Biomaterial Interactions: Cellular MechanicsCell and Tissue Mechanobiology, W. Guo, P. Alvarez, and Y. WangBiology, Biomechanics, Biomaterial Interactions: Materials-Host InteractionsCell-Material In

  9. Biomaterials for MEMS

    Chiao, Mu

    2011-01-01

    This book serves as a guide for practicing engineers, researchers, and students interested in MEMS devices that use biomaterials and biomedical applications. It is also suitable for engineers and researchers interested in MEMS and its applications but who do not have the necessary background in biomaterials.Biomaterials for MEMS highlights important features and issues of biomaterials that have been used in MEMS and biomedical areas. Hence this book is an essential guide for MEMS engineers or researchers who are trained in engineering institutes that do not provide the background or knowledge

  10. Grand challenge in Biomaterials-wound healing

    Salamone, Joseph C.; Salamone, Ann Beal; Swindle-Reilly, Katelyn; Leung, Kelly Xiaoyu-Chen; McMahon, Rebecca E.

    2016-01-01

    Providing improved health care for wound, burn and surgical patients is a major goal for enhancing patient well-being, in addition to reducing the high cost of current health care treatment. The introduction of new and novel biomaterials and biomedical devices is anticipated to have a profound effect on the future improvement of many deleterious health issues. This publication will discuss the development of novel non-stinging liquid adhesive bandages in healthcare applications developed by R...

  11. Introduction to biomaterials

    Donglu, Shi

    2005-01-01

    This book provides a comprehensive introduction to the fundamentals of biomaterials including ceramics, metals, and polymers.Researchers will benefit from the interdisciplinary perspectives of contributors in diverse areas such as orthopedics, biochemistry, biomedical engineering, materials science, tissue engineering and other related medical fields.Both graduate and undergraduate students will find it a valuable reference on tissue engineering related topics, including biostructures and phase diagrams of complex systems, hard tissue prosthetics, novel biomaterials processing methods, and new

  12. 几种高分子生物材料屏障作用预防肌腱粘连的系统评价%Barrier effects of various high polymer biomaterials on prevention of tendon adhesionA systemic evaluation

    胡金萍

    2009-01-01

    OBJECTIVE:To evaluate the safety of various high polymer biomaterials to prevent tendon adhesion,and analyze whether the improvement of injured degree,toxic and side effects,and slipping function of tendon can influence tendon healing.METHODS:A computer-based online search of CNKI was undertaken to identify randomized controlled articles about the effect of various high polymer biomaterials on tendon adhesion with the keywords of "tendon adhesion,biomaterials,and barrier" from 1990 to 2005.Retrieval data were then extracted and analyzed.RESULTS:Among 11 tests,there were 571 patients with tendon injury and 7 animal models with tendon injury,according to inclusion criteria.After surgery,high polymer biomaterials were used to prevent from adhesion and reduce exogenous adhesion incidence.Following-up results demonstrated that high polymer biomaterials which affected endogenous and exogenous healing of tendon might prevent from tendon adhesion,provide foundation for early controlling passive activity,reduce exogenous adhesion occurrence,improve moving function of tendon,and promote tendon healing.CONCLUSION:Barrier effect of high polymer biomaterials can well prevent from tendon adhesion in clinic,especially intrathecal injection or local injection of sodium hyaluronate has both trophic and lubricant actions in preventing from tendon adhesion.However,other effective indicators and safety need to be further studied due to less including tests and weak evidences.%目的:评价不同高分子生物材料预防肌腱粘连的安全性,分析不同高分子生物材料在预防肌腱粘连中对组织的损伤程度、毒副作用、对肌腱滑移功能的改善,是否影响肌腱愈合等方面的优缺点.方法:以计算机检索方法在检索中国期刊全文数据库中(CNKI:1990/2005)检索关于不同高分子材料预防肌腱粘连的临床研究与实验研究的随机对照实验,检索词为"肌腱粘连、生物材料、屏障".检索后对每项研究的资

  13. Effect of biomaterial properties on bone healing in a rabbit tooth extraction socket model

    Fisher, J.P.; Lalani, Z.; Bossano, C.M.; Brey, E.M.; Demian, N.; Johnston, C.M.; Dean, D.; Jansen, J.A.; Wong, M.E.; Mikos, A.G.

    2004-01-01

    In this work we sought to understand the effect of biomaterial properties upon healing bone tissue. We hypothesized that a hydrophilic polymer gel implanted into a bone tissue defect would impede the healing process owing to the biomaterial's prevention of protein adsorption and thus cell adhesion.

  14. Mechanistic investigation of a hemostatic keratin biomaterial

    Rahmany, Maria Bahawdory

    Traumatic injury leads to more productive years lost than heart disease, cancer and stroke combined. Trauma is often accompanied and complicated by uncontrolled bleeding. Human hair keratin biomaterials have demonstrated efficacy in controlling hemorrhage in both small and large animal models; however little is known about the mechanism by which these proteins aid in blood clotting. Inspection of the amino acid sequence of known keratins shows the presence of several cellular binding motifs, suggesting a possible mechanism and potentially eliminating the need to functionalize the material's surface for cellular interaction. In addition to small animal studies, the hemostatic activity of keratin hydrogels was explored through porcine hemorrhage models representing both a high flow and low flow bleed. In both studies, keratin hydrogels appeared to lead to a significant reduction in blood loss. The promising results from these in vivo studies provided the motivation for this project. The objective of this dissertation work was to assess the mechanism of action of a hemostatic keratin biomaterial, and more broadly assess the biomaterial-cellular interaction(s). It is our hypothesis that keratin biomaterials have the capacity to specifically interact with cells and lead to propagation of intracellular signaling pathway, specifically contributing to hemostasis. Through application of biochemical and molecular tools, we demonstrate here that keratin biomaterials contribute to hemostasis through two probable mechanisms; integrin mediated platelet adhesion and increased fibrin polymerization. Platelets are the major cell type involved in coagulation both by acting as a catalytic surface for the clotting cascade and adhering to extracellular matrix (ECM) proteins providing a soft platelet plug. Because keratin biomaterials have structural and biochemical characteristics similar to ECM proteins, we utilized several adhesion assays to investigate platelet adhesion to keratin

  15. Regenerative biomaterials: a review.

    Banyard, Derek A; Bourgeois, Jenna Martin; Widgerow, Alan D; Evans, Gregory R D

    2015-06-01

    The authors present a review of biomaterials, substances traditionally derived from human or animal tissue or, more recently, biodegradable synthetics modeled after naturally occurring resources. These constructs differ from purely synthetic materials in that they are degraded or incorporated into a host's tissue. These biomaterials include a diverse array of medical products, such as acellular dermal matrix, bone substitutes, and injectables. In this review, the authors examine various clinical applications, including burn reconstruction and wound healing, breast surgery, complex abdominal wall reconstruction, craniofacial repair, and cosmetic surgery. Biomaterials such as acellular dermal matrix have proven beneficial in difficult-to-treat applications; however, more prospective data are needed to determine their true efficacy and cost-effectiveness. PMID:26017603

  16. Advanced biomaterials and biodevices

    Tiwari, Ashutosh

    2014-01-01

    Biomaterials are the fastest-growing emerging field of  biodevices. Design and development of biomaterials play a significant role in the diagnosis, treatment, and prevention of diseases. Recently, a variety of scaffolds/carriers have been evaluated for tissue regeneration, drug delivery, sensing and imaging.  Liposomes and microspheres have been developed for sustained delivery. Several anti-cancer drugs have been successfully formulated using biomaterial. The targeting of drugs to certain physiological sites has emerged as a promising tool in the treatment with improved drug bioavailability and reduction of dosing frequency. Biodevices-based targeting of drugs may improve the therapeutic success by limiting the adverse drug effects and resulting in more patient compliance and attaining a higher adherence level. Advanced biodevices hold merit as a drug carrier with high carrier capacity, feasibility of incorporation of both hydrophilic and hydrophobic substances, high stability, as well as the feasibility...

  17. Biomaterials and magnetism

    D Bahadur; Jyotsnendu Giri

    2003-06-01

    Magnetism plays an important role in different applications of health care. Magnetite (Fe34) is biocompatible and therefore is one of the most extensively used biomaterials for different applications ranging from cell separation and drug delivery to hyperthermia. Other than this, a large number of magnetic materials in bulk as well as in the form of nano particles have been exploited for a variety of medical applications. In this review, we summarize the salient features of clinical applications, where magnetic biomaterials are used. Magnetic intracellular hyperthermia for cancer therapy is discussed in detail.

  18. Biomaterials and therapeutic applications

    Ferraro, Angelo

    2016-03-01

    A number of organic and inorganic, synthetic or natural derived materials have been classified as not harmful for the human body and are appropriate for medical applications. These materials are usually named biomaterials since they are suitable for introduction into living human tissues of prosthesis, as well as for drug delivery, diagnosis, therapies, tissue regeneration and many other clinical applications. Recently, nanomaterials and bioabsorbable polymers have greatly enlarged the fields of application of biomaterials attracting much more the attention of the biomedical community. In this review paper I am going to discuss the most recent advances in the use of magnetic nanoparticles and biodegradable materials as new biomedical tools.

  19. Characterizing biomaterial complexity

    L.A. Clifton

    2009-07-01

    Full Text Available Biomaterials research will always require a range of techniques to examine structure and function on a range of length scales and in a range of settings. Neutron scattering provides a unique way of disentangling the molecular and structural complexity of biomaterials through study of the constituent components. We examine how the technique has been used to study surface immobilized proteins and lipid films, floating lipid bilayers as mimics of in vitro planar membranes, and formation of fibres from solution by insects and spiders.

  20. Ethics in biomaterials research.

    Kashi, Ajay; Saha, Subrata

    2009-01-01

    There have been rapid advances in biomaterials research in the past few decades, which have influenced almost all areas of medicine and dentistry. Many ethical concerns related to the use of biomaterials fabricated from artificial substances including metals, polymers, and ceramics have been raised in the past. Most of these include safety and potential harmful effects on the human body. The development of biomaterials that incorporate biological materials such as cells with more traditional, non-biological materials will likely mean that new ethical questions will arise. With significant advances in molecular and cell biology and nanotechnology, the need for safe and effective therapies will also create unique ethical situations in the future. The use of animals in biomedical research has generated opposition from animal rights groups, which has created new challenges to scientists and researchers that warrant further actions. Responsible research by biomaterial scientists in the future will necessitate the incorporation of many new rules and regulations to the existing code of ethics. These will be necessary if new-age materials from emerging areas of science and technology are going to be morally and ethically acceptable to the scientific community and to society. PMID:20402627

  1. Nanoscale biomaterial interface modification for advanced tissue engineering applications

    Recently, various stem cells, including mesenchymal stem cells (MSCs), have been found to have considerable potential for application in tissue engineering and future advanced therapies due to their biological capability to differentiate into specific lineages. Modified surface properties, such as composition, nano-roughness and wettability, affect the most important processes at the biomaterial interface. The aim of the present is work is to study the stem cells' (MSCs) adhesive potential, morphology, phenotypical characteristics in in vitro tests, and to distinguish betwen the different factors influencing the cell/biomaterial interaction, such as nano-topography, surface chemistry and surface free energy.

  2. Biomaterials engineered for integration

    Lorenzo Moroni

    2008-05-01

    Full Text Available As tissue engineering and regenerative medicine are staged to enter the medical care setting, the integration of these newly formed tissues with themselves and the surrounding natural environment of the treated patients is of paramount importance. Although cells alone have undoubtedly obtained a certain success as therapies for a number of different diseases, it is still unclear whether they form new tissues or they stimulate the local cells to restore tissue continuity. In both cases, the resulting outcome is often poorly connected with the surrounding environment and functionality is impaired after few months. True integration can be achieved by designing smart templates made of biomaterials that not only act as scaffolds for cells to adhere and form new tissue, but also provide cues and signals to promote functional tissue connections. Criteria to engineer biomaterials for integration and methodologies used to assess effective connection with host tissues are reviewed.

  3. Biomaterials surface science

    Taubert, Andreas; Rodriguez-Cabello, José Carlos

    2013-01-01

    The book provides an overview of the highly interdisciplinary field of surface science in the context of biological and biomedical applications. The covered topics range from micro- and nanostructuring for imparting functionality in a top-down manner to the bottom-up fabrication of gradient surfaces by self-assembly, from interfaces between biomaterials and living matter to smart, stimuli-responsive surfaces, and from cell and surface mechanics to the elucidation of cell-chip interactions in biomedical devices.

  4. Biomaterials for tendon repair

    Rupal Mehta

    2008-01-01

    Electrospinning biomaterials for tendon repair A single bundle of electrospun submicron polycaprolactone fibres. The team at The University of Manchester believes the material could aid regeneration in tendons. Scientists at The University of Manchester, UK, are investigating the use of electrospun polycaprolactone nanofibres to regenerate damaged tendons. Because the bundle of fibres replicates the morphology of tendon tissue, researchers envisage that the synthetic structure will...

  5. Biomaterials for periodontal regeneration

    Shue, Li; Yufeng, Zhang; Mony, Ullas

    2012-01-01

    Periodontal disease is characterized by the destruction of periodontal tissues. Various methods of regenerative periodontal therapy, including the use of barrier membranes, bone replacement grafts, growth factors and the combination of these procedures have been investigated. The development of biomaterials for tissue engineering has considerably improved the available treatment options above. They fall into two broad classes: ceramics and polymers. The available ceramic-based materials inclu...

  6. Inorganic Biomaterials Characterization

    Kalaskar, D.; Seifalinan, A.; Salmasi, S.; Prinsloo, N.

    2014-01-01

    The biocompatibility of a material is crucial in branding it as a biomaterial. Building on the previous biocompatibility chapter, this chapter mainly focuses on the assessment of biocompatibility. The main aims of biocompatibility assessment are: 1) raw material characterisation; 2) in vitro; and 3) in vivo assessment of materials. Figure 3.1 shows a schematic representation of the components of biocompatibility assessment. This chapter will deal with each of these characterisa...

  7. Plasma-treated polystyrene surfaces : model surfaces for studying cell-biomaterial interactions

    van Kooten, TG; Spijker, HT; Busscher, HJ

    2004-01-01

    Biocompatibility of biomaterials relates, amongst others, to the absence of adverse cellular reactions and modulation of cell adhesion and subsequent responses. With respect to tissue-engineering applications, most materials need to evoke cell adhesion and spreading, while potentially displaying dif

  8. Biomaterials for craniofacial reconstruction

    Neumann, Andreas

    2009-01-01

    Full Text Available Biomaterials for reconstruction of bony defects of the skull comprise of osteosynthetic materials applied after osteotomies or traumatic fractures and materials to fill bony defects which result from malformation, trauma or tumor resections. Other applications concern functional augmentations for dental implants or aesthetic augmentations in the facial region.For ostheosynthesis, mini- and microplates made from titanium alloys provide major advantages concerning biocompatibility, stability and individual fitting to the implant bed. The necessity of removing asymptomatic plates and screws after fracture healing is still a controversial issue. Risks and costs of secondary surgery for removal face a low rate of complications (due to corrosion products when the material remains in situ. Resorbable osteosynthesis systems have similar mechanical stability and are especially useful in the growing skull.The huge variety of biomaterials for the reconstruction of bony defects makes it difficult to decide which material is adequate for which indication and for which site. The optimal biomaterial that meets every requirement (e.g. biocompatibility, stability, intraoperative fitting, product safety, low costs etc. does not exist. The different material types are (autogenic bone and many alloplastics such as metals (mainly titanium, ceramics, plastics and composites. Future developments aim to improve physical and biological properties, especially regarding surface interactions. To date, tissue engineered bone is far from routine clinical application.

  9. Biomaterials in tissue engineering.

    Hubbell, J A

    1995-06-01

    Biomaterials play a pivotal role in field of tissue engineering. Biomimetic synthetic polymers have been created to elicit specific cellular functions and to direct cell-cell interactions both in implants that are initially cell-free, which may serve as matrices to conduct tissue regeneration, and in implants to support cell transplantation. Biomimetic approaches have been based on polymers endowed with bioadhesive receptor-binding peptides and mono- and oligosaccharides. These materials have been patterned in two- and three-dimensions to generate model multicellular tissue architectures, and this approach may be useful in future efforts to generate complex organizations of multiple cell types. Natural polymers have also played an important role in these efforts, and recombinant polymers that combine the beneficial aspects of natural polymers with many of the desirable features of synthetic polymers have been designed and produced. Biomaterials have been employed to conduct and accelerate otherwise naturally occurring phenomena, such as tissue regeneration in wound healing in the otherwise healthy subject; to induce cellular responses that might not be normally present, such as healing in a diseased subject or the generation of a new vascular bed to receive a subsequent cell transplant; and to block natural phenomena, such as the immune rejection of cell transplants from other species or the transmission of growth factor signals that stimulate scar formation. This review introduces the biomaterials and describes their application in the engineering of new tissues and the manipulation of tissue responses. PMID:9634795

  10. Grand challenge in Biomaterials-wound healing.

    Salamone, Joseph C; Salamone, Ann Beal; Swindle-Reilly, Katelyn; Leung, Kelly Xiaoyu-Chen; McMahon, Rebecca E

    2016-06-01

    Providing improved health care for wound, burn and surgical patients is a major goal for enhancing patient well-being, in addition to reducing the high cost of current health care treatment. The introduction of new and novel biomaterials and biomedical devices is anticipated to have a profound effect on the future improvement of many deleterious health issues. This publication will discuss the development of novel non-stinging liquid adhesive bandages in healthcare applications developed by Rochal Industries. The scientists/engineers at Rochal have participated in commercializing products in the field of ophthalmology, including rigid gas permeable contact lenses, soft hydrogel contact lenses, silicone hydrogel contact lenses, contact lens care solutions and cleaners, intraocular lens materials, intraocular controlled drug delivery, topical/intraocular anesthesia, and in the field of wound care, as non-stinging, spray-on liquid bandages to protect skin from moisture and body fluids and medical adhesive-related skin injuries. Current areas of entrepreneurial activity at Rochal Industries pertain to the development of new classes of biomaterials for wound healing, primarily in regard to microbial infection, chronic wound care, burn injuries and surgical procedures, with emphasis on innovation in product creation, which include cell-compatible substrates/scaffolds for wound healing, antimicrobial materials for opportunistic pathogens and biofilm reduction, necrotic wound debridement, scar remediation, treatment of diabetic ulcers, amelioration of pressure ulcers, amelioration of neuropathic pain and adjuvants for skin tissue substitutes. PMID:27047680

  11. Sugared biomaterial binding lectins: achievements and perspectives.

    Bojarová, P; Křen, V

    2016-07-19

    Lectins, a distinct group of glycan-binding proteins, play a prominent role in the immune system ranging from pathogen recognition and tuning of inflammation to cell adhesion or cellular signalling. The possibilities of their detailed study expanded along with the rapid development of biomaterials in the last decade. The immense knowledge of all aspects of glycan-lectin interactions both in vitro and in vivo may be efficiently used in bioimaging, targeted drug delivery, diagnostic and analytic biological methods. Practically applicable examples comprise photoluminescence and optical biosensors, ingenious three-dimensional carbohydrate microarrays for high-throughput screening, matrices for magnetic resonance imaging, targeted hyperthermal treatment of cancer tissues, selective inhibitors of bacterial toxins and pathogen-recognising lectin receptors, and many others. This review aims to present an up-to-date systematic overview of glycan-decorated biomaterials promising for interactions with lectins, especially those applicable in biology, biotechnology or medicine. The lectins of interest include galectin-1, -3 and -7 participating in tumour progression, bacterial lectins from Pseudomonas aeruginosa (PA-IL), E. coli (Fim-H) and Clostridium botulinum (HA33) or DC-SIGN, receptors of macrophages and dendritic cells. The spectrum of lectin-binding biomaterials covered herein ranges from glycosylated organic structures, calixarene and fullerene cores over glycopeptides and glycoproteins, functionalised carbohydrate scaffolds of cyclodextrin or chitin to self-assembling glycopolymer clusters, gels, micelles and liposomes. Glyconanoparticles, glycan arrays, and other biomaterials with a solid core are described in detail, including inorganic matrices like hydroxyapatite or stainless steel for bioimplants. PMID:27075026

  12. Bacterial adhesion to orthopaedic implant materials and a novel oxygen plasma modified PEEK surface

    Rochford, E. T. J.; Poulsson, A. H. C.; Salavarrieta Varela, J.; Lezuo, P.; Richards, R. G.; Moriarty, T. F.

    2014-01-01

    Despite extensive use of polyetheretherketone (PEEK) in biomedical applications, information about bacterial adhesion to this biomaterial is limited. This study investigated Staphylococcus aureus and Staphylococcus epidermidis adhesion to injection moulded and machined PEEK OPTIMA (R) using a custom

  13. Integrated Biomaterials in Tissue Engineering

    Ramalingam, Murugan; Ramakrishna, Seeram; Kobayashi, Hisatoshi; Haikel, Youssef

    2012-01-01

    "Integrated Biomaterials in Tissue Engineering" features all aspects from fundamental principles to current technological advances in biomaterials at the macro/micro/nano/molecular scales suitable for tissue engineering and regenerative medicine. The book is unique as it provides all important aspects dealing with the basic science involved in structure and properties, techniques and technological innovations in material processing and characterizations, and applications of biomaterials in tissue engineering and regenerative medicine.

  14. In vitro evaluation of three different biomaterials as scaffolds for canine mesenchymal stem cells

    Oduvaldo Câmara Marques Pereira-Junior

    2013-05-01

    Full Text Available PURPOSE: To evaluate in vitro ability the of three different biomaterials - purified hydroxyapatite, demineralized bone matrix and castor oil-based polyurethane - as biocompatible 3D scaffolds for canine bone marrow mesenchymal stem cell (MSC intending bone tissue engineering. METHODS: MSCs were isolated from canine bone marrow, characterized and cultivated for seven days with the biomaterials. Cell proliferation and adhesion to the biomaterial surface were evaluated by scanning electron microscopy while differentiation into osteogenic lineage was evaluated by Alizarin Red staining and Sp7/Osterix surface antibody marker. RESULTS: The biomaterials allowed cellular growth, attachment and proliferation. Osteogenic differentiation occurred in the presence of hydroxyapatite, and matrix deposition commenced in the presence of the castor oil-based polyurethane. CONCLUSION: All the tested biomaterials may be used as mesenchymal stem cell scaffolds in cell-based orthopedic reconstructive therapy.

  15. Biomaterials. The Behavior of Stainless Steel as a Biomaterial

    Sanda VISAN

    2011-06-01

    Full Text Available The biomaterials belong to the broad range of biocompatible chemical substances (sometimes even an element, which can be used for a period of time to treat or replace a tissue, organ or function of the human body. These materials bring many advantages in the diagnosis, prevention and medical therapy, reducing downtime for patients, restoring their biological functions, improving hospital management. The market in Romania sells a wide range of biomaterials for dental, cardiovascular medicine, renal, etc. Scientific research contributes to the discovery of new biomaterials or testing known biomaterials, for finding new applications. The paper exemplifies this contribution by presenting the testing of passive stainless steel behaviour in albumin solution using technique of cyclic voltammetry. It was shown that passivation contribute to increased stability of stainless steel implants to corrosive body fluids.

  16. Calcium Phosphate Biomaterials: An Update

    2005-01-01

    Current calcium phosphate (CaP) biomaterials for bone repair, substitution, augmentation and regeneration include hydroxyapatite ( HA ) from synthetic or biologic origin, beta-tricalcium phosphate ( β-TCP ) , biphasic calcium phosphate (BCP), and are available as granules, porous blocks, components of composites (CaP/polymer) cements, and as coatings on orthopedic and dental implants. Experimental calcium phosphate biomaterials include CO3- and F-substituted apatites, Mg-and Zn-substituted β-TCP, calcium phosphate glasses. This paper is a brief review of the different types of CaP biomaterials and their properties such as bioactivity, osteoconductivity, osteoinductivity.

  17. Self-healing biomaterials(3)

    Brochu, Alice B. W.; Craig, Stephen L.; Reichert, William M.

    2010-01-01

    The goal of this review is to introduce the biomaterials community to the emerging field of self-healing materials, and also to suggest how one could utilize and modify self-healing approaches to develop new classes of biomaterials. A brief discussion of the in vivo mechanical loading and resultant failures experienced by biomedical implants is followed by presentation of the self-healing methods for combating mechanical failure. If conventional composite materials that retard failure may be ...

  18. Microgel mechanics in biomaterial design.

    Saxena, Shalini; Hansen, Caroline E; Lyon, L Andrew

    2014-08-19

    The field of polymeric biomaterials has received much attention in recent years due to its potential for enhancing the biocompatibility of systems and devices applied to drug delivery and tissue engineering. Such applications continually push the definition of biocompatibility from relatively straightforward issues such as cytotoxicity to significantly more complex processes such as reducing foreign body responses or even promoting/recapitulating natural body functions. Hydrogels and their colloidal analogues, microgels, have been and continue to be heavily investigated as viable materials for biological applications because they offer numerous, facile avenues in tailoring chemical and physical properties to approach biologically harmonious integration. Mechanical properties in particular are recently coming into focus as an important manner in which biological responses can be altered. In this Account, we trace how mechanical properties of microgels have moved into the spotlight of research efforts with the realization of their potential impact in biologically integrative systems. We discuss early experiments in our lab and in others focused on synthetic modulation of particle structure at a rudimentary level for fundamental drug delivery studies. These experiments elucidated that microgel mechanics are a consequence of polymer network distribution, which can be controlled by chemical composition or particle architecture. The degree of deformability designed into the microgel allows for a defined response to an imposed external force. We have studied deformation in packed colloidal phases and in translocation events through confined pores; in all circumstances, microgels exhibit impressive deformability in response to their environmental constraints. Microgels further translate their mechanical properties when assembled in films to the properties of the bulk material. In particular, microgel films have been a large focus in our lab as building blocks for self

  19. Host response to biomaterials the impact of host response on biomaterial selection

    Badylak, Stephen F

    2015-01-01

    Host Response to Biomaterials: The Impact of Host Response on Biomaterial Selection explains the various categories of biomaterials and their significance for clinical applications, focusing on the host response to each biomaterial. It is one of the first books to connect immunology and biomaterials with regard to host response. The text also explores the role of the immune system in host response, and covers the regulatory environment for biomaterials, along with the benefits of synthetic versus natural biomaterials, and the transition from simple to complex biomaterial solutions. Fiel

  20. Characterization of Bone Marrow Mononuclear Cells on Biomaterials for Bone Tissue Engineering In Vitro

    Dirk Henrich

    2015-01-01

    Full Text Available Bone marrow mononuclear cells (BMCs are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma, demineralized bone matrix (DBM, and bovine cancellous bone (BS were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo.

  1. Characterization of bone marrow mononuclear cells on biomaterials for bone tissue engineering in vitro.

    Henrich, Dirk; Verboket, René; Schaible, Alexander; Kontradowitz, Kerstin; Oppermann, Elsie; Brune, Jan C; Nau, Christoph; Meier, Simon; Bonig, Halvard; Marzi, Ingo; Seebach, Caroline

    2015-01-01

    Bone marrow mononuclear cells (BMCs) are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma), demineralized bone matrix (DBM), and bovine cancellous bone (BS) were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo. PMID:25802865

  2. Macrophages, Foreign Body Giant Cells and Their Response to Implantable Biomaterials

    Zeeshan Sheikh

    2015-08-01

    Full Text Available All biomaterials, when implanted in vivo, elicit cellular and tissue responses. These responses include the inflammatory and wound healing responses, foreign body reactions, and fibrous encapsulation of the implanted materials. Macrophages are myeloid immune cells that are tactically situated throughout the tissues, where they ingest and degrade dead cells and foreign materials in addition to orchestrating inflammatory processes. Macrophages and their fused morphologic variants, the multinucleated giant cells, which include the foreign body giant cells (FBGCs are the dominant early responders to biomaterial implantation and remain at biomaterial-tissue interfaces for the lifetime of the device. An essential aspect of macrophage function in the body is to mediate degradation of bio-resorbable materials including bone through extracellular degradation and phagocytosis. Biomaterial surface properties play a crucial role in modulating the foreign body reaction in the first couple of weeks following implantation. The foreign body reaction may impact biocompatibility of implantation devices and may considerably impact short- and long-term success in tissue engineering and regenerative medicine, necessitating a clear understanding of the foreign body reaction to different implantation materials. The focus of this review article is on the interactions of macrophages and foreign body giant cells with biomaterial surfaces, and the physical, chemical and morphological characteristics of biomaterial surfaces that play a role in regulating the foreign body response. Events in the foreign body response include protein adsorption, adhesion of monocytes/macrophages, fusion to form FBGCs, and the consequent modification of the biomaterial surface. The effect of physico-chemical cues on macrophages is not well known and there is a complex interplay between biomaterial properties and those that result from interactions with the local environment. By having a

  3. Abdominal Adhesions

    ... adhesions? Abdominal adhesions can cause intestinal obstruction and female infertility—the inability to become pregnant after a year of trying. Abdominal adhesions can lead to female infertility by preventing fertilized eggs from reaching the uterus, ...

  4. Radiation produced biomaterials

    Medical advances that have prolonged the average life span have generated increased need for new materials that can be used as tissue and organ replacements, drug delivery systems and/or components of devices related to therapy and diagnosis. The first man-made plastic used as surgical implant was celluloid, applied for cranial defect repair. However, the first users applied commercial materials with no regard for their purity, biostability and post-operative interaction with the organism. Thus, these materials evoked a strong tissue reaction and were unacceptable. The first polymer which gained acceptance for man-made plastic was poly(methyl methacrylate). But the first polymer of choice, precursor of the broad class of materials known today as hydrogels, was poly(hydroxyethyl methacrylate) synthesized in the fifties by Wichterle and Lim. HEMA and its various combinations with other, both hydrophilic and hydrophobic, polymers are till now the most often used hydrogels for medical purposes. In the early fifties, the pioneers of the radiation chemistry of polymers began some experiments with radiation crosslinking, also with hydrophilic polymers. However, hydrogels were analyzed mainly from the point of view of phenomena associated with mechanism of reactions, topology of network, and relations between radiation parameters of the processes. Fundamental monographs on radiation polymer physics and chemistry written by Charlesby (1960) and Chapiro (1962) proceed from this time. The noticeable interest in application of radiation to obtain hydrogels for biomedical purposes began in the late sixties as a result of the papers and patents published by Japanese and American scientists. Among others, the team of the Takasaki Radiation Chemistry Research Establishment headed by Kaetsu as well as Hoffman and his colleagues from the Center of Bioengineering, University of Washington have created the base for spreading interest in the field of biomaterials formed by means of

  5. Development of biomaterial scaffold for nerve tissue engineering: Biomaterial mediated neural regeneration

    Sethuraman Swaminathan

    2009-11-01

    Full Text Available Abstract Neural tissue repair and regeneration strategies have received a great deal of attention because it directly affects the quality of the patient's life. There are many scientific challenges to regenerate nerve while using conventional autologous nerve grafts and from the newly developed therapeutic strategies for the reconstruction of damaged nerves. Recent advancements in nerve regeneration have involved the application of tissue engineering principles and this has evolved a new perspective to neural therapy. The success of neural tissue engineering is mainly based on the regulation of cell behavior and tissue progression through the development of a synthetic scaffold that is analogous to the natural extracellular matrix and can support three-dimensional cell cultures. As the natural extracellular matrix provides an ideal environment for topographical, electrical and chemical cues to the adhesion and proliferation of neural cells, there exists a need to develop a synthetic scaffold that would be biocompatible, immunologically inert, conducting, biodegradable, and infection-resistant biomaterial to support neurite outgrowth. This review outlines the rationale for effective neural tissue engineering through the use of suitable biomaterials and scaffolding techniques for fabrication of a construct that would allow the neurons to adhere, proliferate and eventually form nerves.

  6. Chitin fulfilling a biomaterials promise

    Khor, Eugene

    2001-01-01

    The second edition of Chitin underscores the important factors for standardizing chitin processing and characterization. It captures the essential interplay between chitin's assets and limitations as a biomaterial, placing the past promises of chitin in perspective, addressing its present realities and offering insight into what is required to realize chitin's destiny (including its derivative, chitosan) as a biomaterial of the twenty-first century. This book is an ideal guide for both industrialists and researchers with a vested interest in commercializing chitin.An upd

  7. 3D Biomaterial Microarrays for Regenerative Medicine

    Gaharwar, Akhilesh K.; Arpanaei, Ayyoob; Andresen, Thomas Lars;

    2015-01-01

    Three dimensional (3D) biomaterial microarrays hold enormous promise for regenerative medicine because of their ability to accelerate the design and fabrication of biomimetic materials. Such tissue-like biomaterials can provide an appropriate microenvironment for stimulating and controlling stem...

  8. Integrated Biomaterials for Biomedical Technology

    Ramalingam, Murugan; Ramakrishna, Seeram; Kobayashi, Hisatoshi

    2012-01-01

    This cutting edge book provides all the important aspects dealing with the basic science involved in materials in biomedical technology, especially structure and properties, techniques and technological innovations in material processing and characterizations, as well as the applications. The volume consists of 12 chapters written by acknowledged experts of the biomaterials field and covers a wide range of topics and applications.

  9. Inorganic biomaterials structure, properties and applications

    Zhang, Xiang C

    2014-01-01

    This book provides a practical guide to the use and applications of inorganic biomaterials. It begins by introducing the concept of inorganic biomaterials, which includes bioceramics and bioglass. This concept is further extended to hybrid biomaterials consisting of inorganic and organic materials to mimic natural biomaterials. The book goes on to provide the reader with information on biocompatibility, bioactivity and bioresorbability. The concept of the latter is important because of the increasing role resorbable biomaterials are playing in implant applications. The book also introduces a n

  10. Adherence ability of Staphylococcus epidermidis on prosthetic biomaterials: an in vitro study

    Shida T

    2013-10-01

    Full Text Available Takayuki Shida,1 Hironobu Koseki,1 Itaru Yoda,1 Hidehiko Horiuchi,1 Hideyuki Sakoda,2 Makoto Osaki11Department of Orthopedic Surgery, Graduate School of Medicine, Nagasaki University, Nagasaki, Japan; 2Division of Medical Devices, National Institute of Health Sciences, Tokyo, JapanAbstract: Bacterial adhesion to the surface of biomaterials is an essential step in the pathogenesis of implant-related infections. In this in vitro research, we evaluated the ability of Staphylococcus epidermidis to adhere to the surface of solid biomaterials, including oxidized zirconium-niobium alloy (Oxinium, cobalt-chromium-molybdenum alloy, titanium alloy, commercially pure titanium, and stainless steel, and performed a biomaterial-to-biomaterial comparison. The test specimens were physically analyzed to quantitatively determine the viable adherent density of the S. epidermidis strain RP62A (American Type Culture Collection [ATCC] 35984. Field emission scanning electron microscope and laser microscope examination revealed a featureless, smooth surface in all specimens (average roughness <10 nm. The amounts of S. epidermidis that adhered to the biomaterial were significantly lower for Oxinium and the cobalt-chromium-molybdenum alloy than for commercially pure titanium. These results suggest that Oxinium and cobalt-chromium-molybdenum alloy are less susceptible to bacterial adherence and are less inclined to infection than other materials of a similar degree of smoothness.Keyword: bacterial adhesion, implant, infection, surface character

  11. Surface free energy predominates in cell adhesion to hydroxyapatite through wettability.

    Nakamura, Miho; Hori, Naoko; Ando, Hiroshi; Namba, Saki; Toyama, Takeshi; Nishimiya, Nobuyuki; Yamashita, Kimihiro

    2016-05-01

    The initial adhesion of cells to biomaterials is critical in the regulation of subsequent cell behaviors. The purpose of this study was to investigate a mechanism through which the surface wettability of biomaterials can be improved and determine the effects of biomaterial surface characteristics on cellular behaviors. We investigated the surface characteristics of various types of hydroxyapatite after sintering in different atmospheres and examined the effects of various surface characteristics on cell adhesion to study cell-biomaterial interactions. Sintering atmosphere affects the polarization capacity of hydroxyapatite by changing hydroxide ion content and grain size. Compared with hydroxyapatite sintered in air, hydroxyapatite sintered in saturated water vapor had a higher polarization capacity that increased surface free energy and improved wettability, which in turn accelerated cell adhesion. We determined the optimal conditions of hydroxyapatite polarization for the improvement of surface wettability and acceleration of cell adhesion. PMID:26952425

  12. Nanostructured Biomaterials for Tissue Engineered Bone Tissue Reconstruction

    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.

  13. Physical approaches to biomaterial design

    Mitragotri, Samir; Lahann, Joerg

    2009-01-01

    The development of biomaterials for drug delivery, tissue engineering and medical diagnostics has traditionally been based on new chemistries. However, there is growing recognition that the physical as well as the chemical properties of materials can regulate biological responses. Here, we review this transition with regard to selected physical properties including size, shape, mechanical properties, surface texture and compartmentalization. In each case, we present examples demonstrating the...

  14. Hybrid laser technology for biomaterials

    Jelínek, Miroslav

    Cambridge : Woodhead Publishing Limited, 2013 - (Jelínková, H.), s. 704-724 ISBN 978-0-85709-237-3. - (Woodhead Publishing Series in Electronic and Optical Materials. 37) Institutional support: RVO:68378271 Keywords : laser * biomaterials * coating * hybrid technology * urology * implantology * textile vessel Subject RIV: BM - Solid Matter Physics ; Magnetism https://woodhead.metapress.com/content/h773r34h5x7q7482/resource-secured/?target=fulltext.pdf

  15. Macrophage response to staphylococcal biofilms on crosslinked poly(ethylene glycol polymer coatings and common biomaterials in vitro

    IC Saldarriaga Fernández

    2011-01-01

    Full Text Available Biomaterial-associated-infections (BAI are serious clinical complications that threaten the longevity of implanted devices and lead to high morbidity and mortality. Poly(ethyleneglycol (PEG coatings have been studied as a strategy to reduce the incidence of BAI by reducing protein deposition that promotes pathogen adhesion and growth on device surfaces. Despite their effectiveness to reduce protein adsorption and a hundred-fold reduction in bacterial adhesion, PEG-based coatings still facilitate weak bacterial adhesion that can form an initial basis for biofilms. Here, we describe a methodology enabling direct, quantitative and detailed qualitative in situ observation of macrophage morphology, migration and phagocytosis of bacteria. In vitro interaction of macrophages with Staphylococcus epidermidis 3399 adhering to commercial, crosslinked PEG-based coatings (OptiChem® was compared with fluorinated ethylene propylene, silicone rubber and glass. Adhesion, phagocytosis and migration were studied real-time in a parallel-plate-flow-chamber. Macrophages cultured on OptiChem® coatings showed enhanced migration and phagocytosis of bacteria compared to common biomaterials. Bacterial clearance per macrophage on both inert and reactive OptiChem® coatings were about three times higher than on the common biomaterials studied, corresponding with up to 70% reduction in bacterial numbers on OptiChem®, whereas on the biomaterials less than 40% bacterial reduction was obtained. These findings show that bacterial clearance from cross-linked PEG-based coatings by macrophages is more effective than from common biomaterials, possibly resulting from weak adhesion of bacteria on Optichem®. Moreover, macrophages exhibit higher mobility on Optichem® retaining an improved capability to clear bacteria from larger areas than from other common biomaterials, where they appear more immobilized.

  16. Adhesive Categories

    Lack, Stephen; Sobocinski, Pawel

    2003-01-01

    We introduce adhesive categories, which are categories with structure ensuring that pushouts along monomorphisms are well-behaved. Many types of graphical structures used in computer science are shown to be examples of adhesive categories. Double-pushout graph rewriting generalises well to...... rewriting on arbitrary adhesive categories....

  17. Adhesive Categories

    Lack, Stephen; Sobocinski, Pawel

    2004-01-01

    We introduce adhesive categories, which are categories with structure ensuring that pushouts along monomorphisms are well-behaved. Many types of graphical structures used in computer science are shown to be examples of adhesive categories. Double-pushout graph rewriting generalises well to...... rewriting on arbitrary adhesive categories....

  18. Dynamic biomaterials: toward engineering autonomous feedback.

    Morris, Eliza; Chavez, Michael; Tan, Cheemeng

    2016-06-01

    Dynamic biomaterials are biocompatible engineered systems capable of sensing and actively responding to their surrounding environment. They are of growing interest, both as models in basic research to understand complex cellular systems and in medical applications. Here, we review recent advances in nano-scale and micro-scale biomaterials, specifically artificial cells consisting of compartmentalized biochemical reactions and biologically compatible hydrogels. These dynamic biomaterials respond to stimuli through triggered reactions, reaction cascades, logic gates, and autonomous feedback loops. We outline the advances and remaining challenges in implementing such 'smart' biomaterials capable of autonomously responding to environmental stimuli. PMID:26974245

  19. Biomaterials & scaffolds for tissue engineering

    Fergal J. O'Brien

    2011-03-01

    Full Text Available Every day thousands of surgical procedures are performed to replace or repair tissue that has been damaged through disease or trauma. The developing field of tissue engineering (TE aims to regenerate damaged tissues by combining cells from the body with highly porous scaffold biomaterials, which act as templates for tissue regeneration, to guide the growth of new tissue. This article describes the functional requirements, and types, of materials used in developing state of the art of scaffolds for tissue engineering applications. Furthermore, it describes the challenges and where future research and direction is required in this rapidly advancing field.

  20. Permeability testing of biomaterial membranes

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail: schlosshauer@nmi.de

    2008-09-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

  1. Permeability testing of biomaterial membranes

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation

  2. Current requirements for polymeric biomaterials in otolaryngology

    Sternberg, Katrin

    2009-01-01

    Full Text Available In recent years otolaryngology was strongly influenced by newly developed implants which are based on both, innovative biomaterials and novel implant technologies. Since the biomaterials are integrated into biological systems they have to fulfill all technical requirements and accommodate biological interactions. Technical functionality relating to implant specific mechanical properties, a sufficiently high stability in terms of physiological conditions, and good biocompatibility are the demands with regard to suitability of biomaterials. The goal in applying biomaterials for implants is to maintain biofunctionality over extended periods of time. These general demands to biomaterials are equally valid for use in otolaryngology. Different classes of materials can be utilized as biomaterials. Metals belong to the oldest biomaterials. In addition, alloys, ceramics, inorganic glasses and composites have been tested successfully. Furthermore, natural and synthetic polymers are widely used materials, which will be in the focus of the current article with regard to their properties and usage as cochlear implants, osteosynthesis implants, stents, and matrices for tissue engineering. Due to their application as permanent or temporary implants materials are differentiated into biostable and biodegradable polymers. The here identified general and up to date requirements for biomaterials and the illustrated applications in otolaryngology emphasize ongoing research efforts in this area and at the same time demonstrate the high significance of interdisciplinary cooperation between natural sciences, engineering, and medical sciences.

  3. Adhesion and viability of two enterococcal strains on covalently grafted chitosan and chitosan/kappa-carrageenan multilayers

    Bratskaya, S.; Marinin, D.; Simon, F.; Synytska, A.; Zschoche, S.; Busscher, H. J.; Jager, D.; van der Mei, H. C.

    2007-01-01

    Chitosans are natural aminopolysaccharides, whose low cytotoxicity suggests their potential use for nonadhesive, antibacterial coatings on biomaterials implant surfaces. Here, the antiadhesive behavior and ability to kill bacteria upon adhesion ("contact killing") of chitosan coatings were evaluated

  4. Micropatterning cell adhesion on polyacrylamide hydrogels.

    Zhang, Jian; Guo, Wei-Hui; Rape, Andrew; Wang, Yu-Li

    2013-01-01

    Cell shape and substrate rigidity play critical roles in regulating cell behaviors and fate. Controlling cell shape on elastic adhesive materials holds great promise for creating a physiologically relevant culture environment for basic and translational research and clinical applications. However, it has been technically challenging to create high-quality adhesive patterns on compliant substrates. We have developed an efficient and economical method to create precise micron-scaled adhesive patterns on the surface of a hydrogel (Rape et al., Biomaterials 32:2043-2051, 2011). This method will facilitate the research on traction force generation, cellular mechanotransduction, and tissue engineering, where precise controls of both materials rigidity and adhesive patterns are important. PMID:23955741

  5. Surgical adhesives

    I. A. THOMAZINI-SANTOS

    2001-12-01

    Full Text Available The authors have performed a literature review of surgical adhesives, such as cyanoacrylate, collagen gelatin, and fibrin glue. They have included different types of commercial and non-commercial fibrin sealants and have reported on the different components in these adhesives, such as fibrinogen, cryoprecipitate, bovine thrombin, and thrombin-like fraction of snake venom.

  6. Biodegradable copolymers carrying cell-adhesion peptide sequences

    Proks, Vladimír; Machová, Luďka; Popelka, Štěpán; Rypáček, František

    Antalya : Ankara University, Tissue Engineering and Biomaterials Laboratory, 2002. s. P-35. [International Symposium on Biomedical Science and Technology BIOMED /9./. 19.09.2002-22.09.2002, Antalya ] R&D Projects: GA AV ČR IAA4050202; GA MŠk LN00A065 Keywords : amphiphilic block copolymers * cell adhesion * biodegradable Subject RIV: CD - Macromolecular Chemistry

  7. 3D porous biomimetically modified hydrogels supporting stem cells adhesion

    Studenovská, Hana; Vodička, Petr; Proks, Vladimír; Juhásová, Jana; Motlík, Jan; Rypáček, František

    Dublin : National University of Ireland , 2011. s. 119, psiii-630. [Annual Conference of the European Society for Biomaterials /24./. 04.09.2011-08.09.2011, Dublin] R&D Projects: GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50450515 Keywords : porous hydrogel * cell adhesion * polypeptide Subject RIV: FH - Neurology

  8. Interactions between bone cells and biomaterials: An update.

    Beauvais, Sabrina; Drevelle, Olivier; Jann, Jessica; Lauzon, Marc-Antoine; Foruzanmehr, Mohammadreza; Grenier, Guillaume; Roux, Sophie; Faucheux, Nathalie

    2016-01-01

     As the populations of the Western world become older, they will suffer more and more from bone defects related to osteoporosis (non-union fractures, vertebral damages), cancers (malignant osteolysis) and infections (osteomyelitis). Autografts are usually used to fill these defects, but they have several drawbacks such as morbidity at the donor site and the amount and quality of bone that can be harvested. Recent scientific milestones made in biomaterials development were shown to be promising to overcome these limitations. Cell interactions with biomaterials can be improved by adding at their surface functional groups such as adhesive peptides and/or growth factors. The development of such biomimetic materials able to control bone cell responses can only proceed if it is based on a sound understanding of bone cell behavior and regulation. This review focuses on bone physiology and the regulation of bone cell differentiation and function, and how the latest advances in biomimetic materials can be translated within promising clinical outcomes. PMID:27100704

  9. A Biodesigned Nanocomposite Biomaterial for Auricular Cartilage Reconstruction.

    Nayyer, Leila; Jell, Gavin; Esmaeili, Ali; Birchall, Martin; Seifalian, Alexander M

    2016-05-01

    Current biomaterials for auricular replacement are associated with high rates of infection and extrusion. The development of new auricular biomaterials that mimic the mechanical properties of native tissue and promote desirable cellular interactions may prevent implant failure. A porous 3D nanocomposite scaffold (NS) based on POSS-PCU (polyhedral oligomeric silsesquioxane nanocage into polycarbonate based urea-urethane) is developed with an elastic modulus similar to native ear. In vitro biological interactions on this NS reveal greater protein adsorption, increased fibroblast adhesion, proliferation, and collagen production compared with Medpor (the current synthetic auricular implant). In vivo, the POSS-PCU with larger pores (NS2; 150-250 μm) have greater tissue ingrowth (≈5.8× and ≈1.4 × increase) than the POSS-PCU with smaller pores (NS1; 100-50 μm) and when compared to Medpor (>100 μm). The NS2 with the larger pores demonstrates a reduced fibrotic encapsulation compared with NS1 and Medpor (≈4.1× and ≈1.6×, respectively; P NS1 (12 weeks postimplantation). The lack of chronic inflammatory response for all materials may indicate that the elastic modulus and pore size of the implant scaffold could be important design considerations for influencing fibrotic responses to auricular and other soft tissue implants. PMID:26992039

  10. Polymeric biomaterials structure and function, v.1

    Dumitriu, Severian

    2013-01-01

    Biomaterials have had a major impact on the practice of contemporary medicine and patient care. Growing into a major interdisciplinary effort involving chemists, biologists, engineers, and physicians, biomaterials development has enabled the creation of high-quality devices, implants, and drug carriers with greater biocompatibility and biofunctionality. The fast-paced research and increasing interest in finding new and improved biocompatible or biodegradable polymers has provided a wealth of new information, transforming this edition of Polymeric Biomaterials into a two-volume set. This volume

  11. Biomaterials and Stem Cells in Regenerative Medicine

    Ramalingam, Murugan; Best, Serena

    2012-01-01

    Work in the area of biomaterials and stem cell therapy has revealed great potential for many applications, from the treatment of localized defects and diseases to the repair and replacement of whole organs. Researchers have also begun to develop a better understanding of the cellular environment needed for optimal tissue repair and regeneration. Biomaterials and Stem Cells in Regenerative Medicine explores a range of applications for biomaterials and stem cell therapy and describes recent research on suitable cell scaffolds and substrates for tissue repair and reconstruction. Featuring contrib

  12. Biomaterials in the repair of sports injuries

    Ducheyne, Paul; Mauck, Robert L.; Smith, Douglas H.

    2012-08-01

    The optimal stimulation of tissue regeneration in bone, cartilage and spinal cord injuries involves a judicious selection of biomaterials with tailored chemical compositions, micro- and nanostructures, porosities and kinetic release properties for the delivery of relevant biologically active molecules.

  13. Interactions of Staphylococcus aureus with ultrasoft hydrogel biomaterials.

    Wang, Yi; Guan, Allan; Isayeva, Irada; Vorvolakos, Katherine; Das, Srilekha; Li, Zhenyu; Phillips, K Scott

    2016-07-01

    Ultrasoft biomaterials-polymers, gels, and human soft tissues with an elastic modulus less than ∼100 kPa-are increasingly used in medical devices. While bacterial interactions (adhesion and biofilm formation) have been extensively studied on stiffer materials, little is known about how bacteria colonize ultrasoft materials as a nidus for infection. The goal of this work was to determine how material properties of ultrasoft hydrogels used for dermal fillers might affect pathogenesis of associated infections. We first synthesized a range of polyacrylamide hydrogels (PAAm) with moduli similar to clinically used dermal fillers and characterized the rheological, morphological and porous properties. We then developed a novel microfabricated insert to contain the PAAm in a flow system for quantification of bacterial adhesion and biofilm formation. The rate of adhesion and numbers of adherent Staphylococcus aureus on the surface of PAAm both decreased as the modulus increased. Adhesion was reduced by 3 logs (from 93 × 10(4)/cm(2) to 0.083 × 10(4)/cm(2)) with increasing modulus (from 17 Pa to 654 Pa). However, the number of bacteria in the bulk was the highest within the stiffest gels. This trend was further amplified in subsequent biofilm studies, where interfacial coverage of biofilm decreased as the modulus increased, while the fraction of biofilm in the bulk was the highest within the stiffest gel. The results show significant differences in bacterial colonization of PAAm based on material properties, and reveal how the injection process may unexpectedly create discontinuities that provide a microenvironmental niche for bacterial colonization. PMID:27131630

  14. Engineering bio-adhesive functions in an antimicrobial polymer multilayer

    Functionalization of a biomaterial surface with adhesive ligands is an effective way to promote specific cell adhesion. Ideally, biomaterial for applications in biomedical implants should simultaneously promote host cell adhesion and inhibit bacterial adhesion. Currently, little attention has been paid to the design of antimicrobial biomaterial with selective adhesiveness towards only targeted cells or tissues. In this study, the role of two typical adhesive ligands on the bioadhesion functions of a model antimicrobial film was elucidated. First, an adhesive ligand including an RGD peptide or collagen (CL) was chemically coupled to an antimicrobial polymeric multilayer composed of dextran sulfate (DS) and chitosan (CS). It was demonstrated that the density of RGD and CL immobilized on the DS/CS multilayer ranges between 4 to 137 ng cm−2 and 100 to 1000 ng cm−2, respectively. Then the effect of immobilized RGD or CL on both bacterial and fibroblast adhesion was investigated. By determining the density and morphology of adherent fibroblast on a DS/CS multilayer with or without an adhesive ligand, it was shown that RGD or CL effectively promoted fibroblast adhesion and proliferation in a concentration-dependent manner. Interestingly, the type of adhesive ligands imposed distinct effects in bacterial adhesion. Immobilized RGD did not enhance Staphylococcus aureus and Escherichia coli adhesion on DS/CS multilayers under all concentrations. In contrast, CL triggered significant S. aureus adhesion on DS/CS multilayers even at low surface concentration and when fibroblast adhesion was absent. Moreover, the detachment forces of individual S. aureus on CL coated DS/CS multilayers probed by atomic force microscopy (AFM) was 3 times and 20 times higher than that on the control substrate and on unmodified DS/CS multilayers, respectively. Interestingly, the lowest detachment force of E. coli was found on the CL coated DS/CS multilayers. This study demonstrated the

  15. Medical applications for biomaterials in Bolivia

    Arias, Susan

    2015-01-01

    This book investigates the potential medical benefits natural biomaterials can offer in developing countries by analyzing the case of Bolivia. The book explores the medical and health related applications of Bolivian commodities: quinoa, barley, sugarcane, corn, sorghum and sunflower seeds. This book helps readers better understand some of the key health concerns facing countries like Bolivia and how naturally derived biomaterials and therapeutics could help substantially alleviate many of their problems.

  16. Biomaterials innovation bundling technologies and life

    Styhre, A

    2014-01-01

    Rapid advances in the life sciences means that there is now a far more detailed understanding of biological systems on the cellular, molecular and genetic levels. Sited at the intersection between the life sciences, the engineering sciences and the design sciences, innovations in the biomaterials industry are expected to garner increasing attention and play a key role in future development. This book examines the biomaterials innovations taking place in corporations and in academic research settings today.

  17. Recent advances of biomaterials in biotherapy.

    Li, Ling; He, Zhi-Yao; Wei, Xia-Wei; Wei, Yu-Quan

    2016-06-01

    Biotherapy mainly refers to the intervention and the treatment of major diseases with biotechnologies or bio-drugs, which include gene therapy, immunotherapy (vaccines and antibodies), bone marrow transplantation and stem-cell therapy. In recent years, numerous biomaterials have emerged and were utilized in the field of biotherapy due to their biocompatibility and biodegradability. Generally, biomaterials can be classified into natural or synthetic polymers according to their source, both of which have attracted much attention. Notably, biomaterials-based non-viral gene delivery vectors in gene therapy are undergoing rapid development with the emergence of surface-modified or functionalized materials. In immunotherapy, biomaterials appear to be attractive means for enhancing the delivery efficacy and the potency of vaccines. Additionally, hydrogels and scaffolds are ideal candidates in stem-cell therapy and tissue engineering. In this review, we present an introduction of biomaterials used in above biotherapy, including gene therapy, immunotherapy, stem-cell therapy and tissue engineering. We also highlighted the biomaterials which have already entered the clinical evaluation. PMID:27047675

  18. Adsorption behavior of heavy metals on biomaterials.

    Minamisawa, Mayumi; Minamisawa, Hiroaki; Yoshida, Shoichiro; Takai, Nobuharu

    2004-09-01

    We have investigated adsorption of Cd(II) and Pb(II) at pH 2-6.7 onto the biomaterials chitosan, coffee, green tea, tea, yuzu, aloe, and Japanese coarse tea, and onto the inorganic adsorbents, activated carbon and zeolite. High adsorptive capabilities were observed for all of the biomaterials at pH 4 and 6.7. In the adsorption of Cd(II), blend coffee, tea, green tea, and coarse tea have comparable loading capacities to activated carbon and zeolite. Although activated carbon, zeolite, and chitosan are utilized in a variety of fields such as wastewater treatment, chemical and metallurgical engineering, and analytical chemistry, these adsorbents are costly. On the other hand, processing of the test biomaterials was inexpensive, and all the biomaterials except for chitosan were able to adsorb large amounts of Pb(II) and Cd(II) ions after a convenient pretreatment of washing with water followed by drying. The high adsorption capability of the biomaterials prepared from plant materials is promising in the development of a novel, low-cost adsorbent. From these results, it is concluded that heavy metal removal using biomaterials would be an effective method for the economic treatment of wastewater. The proposed adsorption method was applied to the determination of amounts of Cd(II) and Pb(II) in water samples. PMID:15373400

  19. Sorption of paracetamol onto biomaterials.

    Ferchichi, Maroua; Dhaouadi, Hatem

    2016-01-01

    Pharmaceutical residues released into the environment are posing more and more public health problems. It is worthwhile to study the retention of pharmaceuticals residues by adsorption on solid supports. Batch sorption experiments are intended to identify the adsorption isotherms of the pharmaceutically active ingredient on the biomaterials. The results obtained in this study have shown that the retention possibilities of these compounds by bio-adsorbents (clay and sand) are not significant. The negligible sorption for these media is explained by the low hydrophobicity of paracetamol (Log K(ow) = 0.46). The retention of paracetamol on the dehydrated sewage sludge and on Posidonia oceanica showed a relatively significant adsorption with a maximal quantity of 0.956 mg g(-1) and 1.638 mg g(-1) for the dehydrate sludge and P. oceanica, respectively. On the other hand, the study of paracetamol retention on the powdered activated carbon showed a high adsorption capacity of about 515.27 mg g(-1). Isotherm data show a good fit with Langmuir's model. An infrared analysis is carried out. It shows identical bands before and after adsorption, with some modifications. PMID:27387007

  20. Engineering ECM signals into biomaterials

    Ryan J. Wade

    2012-10-01

    Full Text Available Historically, tissue engineering focused primarily on the delivery of soluble factors within relatively static scaffolds; yet, increasing evidence indicates that the native, dynamic three-dimensional microenvironment is important in guiding cellular behavior. Consequently, there has been a recent emphasis on increasing the biocomplexity of scaffolds to better mimic the natural extracellular matrix (ECM, including the incorporation of adhesion, degradation, and three-dimensional structures. This review aims to describe important features of the natural ECM and highlight how these features are now being incorporated into synthetic materials to control cellular behavior and tissue evolution towards the development of next generation tissue engineering strategies.

  1. Development of a hybrid scaffold with synthetic biomaterials and hydrogel using solid freeform fabrication technology

    Shim, Jin-Hyung; Park, Min; Park, Jaesung; Cho, Dong-Woo [Department of Mechanical Engineering, POSTECH (Korea, Republic of); Kim, Jong Young, E-mail: dwcho@postech.ac.kr [Department of Mechanical Engineering, Andong National University (Korea, Republic of)

    2011-09-15

    Natural biomaterials such as hyaluronic acid, gelatin and collagen provide excellent environments for tissue regeneration. Furthermore, gel-state natural biomaterials are advantageous for encapsulating cells and growth factors. In cell printing technology, hydrogel which contains cells was printed directly to form three-dimensional (3D) structures for tissue or organ regeneration using various types of printers. However, maintaining the 3D shape of the printed structure, which is made only of the hydrogel, is very difficult due to its weak mechanical properties. In this study, we developed a hybrid scaffold consisting of synthetic biomaterials and natural hydrogel using a multi-head deposition system, which is useful in solid freeform fabrication technology. The hydrogel was intentionally infused into the space between the lines of a synthetic biomaterial-based scaffold. The cellular efficacy of the hybrid scaffold was validated using rat primary hepatocytes and a mouse pre-osteoblast MC3T3-E1 cell line. In addition, the collagen hydrogel, which encapsulates cells, was dispensed and the viability of the cells observed. We demonstrated superior effects of the hybrid scaffold on cell adhesion and proliferation and showed the high viability of dispensed cells.

  2. Development of a hybrid scaffold with synthetic biomaterials and hydrogel using solid freeform fabrication technology

    Natural biomaterials such as hyaluronic acid, gelatin and collagen provide excellent environments for tissue regeneration. Furthermore, gel-state natural biomaterials are advantageous for encapsulating cells and growth factors. In cell printing technology, hydrogel which contains cells was printed directly to form three-dimensional (3D) structures for tissue or organ regeneration using various types of printers. However, maintaining the 3D shape of the printed structure, which is made only of the hydrogel, is very difficult due to its weak mechanical properties. In this study, we developed a hybrid scaffold consisting of synthetic biomaterials and natural hydrogel using a multi-head deposition system, which is useful in solid freeform fabrication technology. The hydrogel was intentionally infused into the space between the lines of a synthetic biomaterial-based scaffold. The cellular efficacy of the hybrid scaffold was validated using rat primary hepatocytes and a mouse pre-osteoblast MC3T3-E1 cell line. In addition, the collagen hydrogel, which encapsulates cells, was dispensed and the viability of the cells observed. We demonstrated superior effects of the hybrid scaffold on cell adhesion and proliferation and showed the high viability of dispensed cells.

  3. Marine Structural Biomaterials in Medical Biomimicry.

    Green, David W; Lee, Jong-Min; Jung, Han-Sung

    2015-10-01

    Marine biomaterials display properties, behaviors, and functions that have not been artificially matched in relation to their hierarchical construction, crack-stopping properties, growth adaptation, and energy efficiency. The discovery and understanding of such features that are characteristic of natural biomaterials can be used to manufacture more energy-efficient and lightweight materials. However, a more detailed understanding of the design of natural biomaterials with good performance and the mechanism of their design is required. Far-reaching biomolecular characterization of biomaterials and biostructures from the ocean world is possible with sophisticated analytical methods, such as whole-genome RNA-seq, and de novo transcriptome sequencing and mass spectrophotometry-based sequencing. In combination with detailed material characterization, the elements in newly discovered biomaterials and their properties can be reconstituted into biomimetic or bio-inspired materials. A major aim of harnessing marine biomaterials is their translation into biomimetic counterparts. To achieve full translation, the genome, proteome, and hierarchical material characteristics, and their profiles in space and time, have to be associated to allow for smooth biomimetic translation. In this article, we highlight the novel science of marine biomimicry from a materials perspective. We focus on areas of material design and fabrication that have excelled in marine biological models, such as embedded interfaces, chiral organization, and the use of specialized composite material-on-material designs. Our emphasis is primarily on key materials with high value in healthcare in which we evaluate their future prospects. Marine biomaterials are among the most exquisite and powerful aspects in materials science today. PMID:25905922

  4. Biomaterials and medical devices a perspective from an emerging country

    Hermawan, Hendra

    2016-01-01

    This book presents an introduction to biomaterials with the focus on the current development and future direction of biomaterials and medical devices research and development in Indonesia. It is the first biomaterials book written by selected academic and clinical experts experts on biomaterials and medical devices from various institutions and industries in Indonesia. It serves as a reference source for researchers starting new projects, for companies developing and marketing products and for governments setting new policies. Chapter one covers the fundamentals of biomaterials, types of biomaterials, their structures and properties and the relationship between them. Chapter two discusses unconventional processing of biomaterials including nano-hybrid organic-inorganic biomaterials. Chapter three addresses biocompatibility issues including in vitro cytotoxicity, genotoxicity, in vitro cell models, biocompatibility data and its related failure. Chapter four describes degradable biomaterial for medical implants...

  5. Heterogeneity of Scaffold Biomaterials in Tissue Engineering

    Lauren Edgar

    2016-05-01

    Full Text Available Tissue engineering (TE offers a potential solution for the shortage of transplantable organs and the need for novel methods of tissue repair. Methods of TE have advanced significantly in recent years, but there are challenges to using engineered tissues and organs including but not limited to: biocompatibility, immunogenicity, biodegradation, and toxicity. Analysis of biomaterials used as scaffolds may, however, elucidate how TE can be enhanced. Ideally, biomaterials should closely mimic the characteristics of desired organ, their function and their in vivo environments. A review of biomaterials used in TE highlighted natural polymers, synthetic polymers, and decellularized organs as sources of scaffolding. Studies of discarded organs supported that decellularization offers a remedy to reducing waste of donor organs, but does not yet provide an effective solution to organ demand because it has shown varied success in vivo depending on organ complexity and physiological requirements. Review of polymer-based scaffolds revealed that a composite scaffold formed by copolymerization is more effective than single polymer scaffolds because it allows copolymers to offset disadvantages a single polymer may possess. Selection of biomaterials for use in TE is essential for transplant success. There is not, however, a singular biomaterial that is universally optimal.

  6. Bacterial Adhesion & Blocking Bacterial Adhesion

    Vejborg, Rebecca Munk

    2008-01-01

    parameters, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion is...... the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental...

  7. Biomaterials-Based Organic Electronic Devices

    Bettinger, Christopher J.; Bao, Zhenan

    2010-01-01

    Organic electronic devices have demonstrated tremendous versatility in a wide range of applications including consumer electronics, photovoltaics, and biotechnology. The traditional interface of organic electronics with biology, biotechnology, and medicine occurs in the general field of sensing biological phenomena. For example, the fabrication of hybrid electronic structures using both organic semiconductors and bioactive molecules has led to enhancements in sensitivity and specificity within biosensing platforms, which in turn has a potentially wide range of clinical applications. However, the interface of biomolecules and organic semiconductors has also recently explored the potential use of natural and synthetic biomaterials as structural components of electronic devices. The fabrication of electronically active systems using biomaterials-based components has the potential to realize a large set of unique devices including environmentally biodegradable systems and bioresorbable temporary medical devices. This article reviews recent advances in the implementation of biomaterials as structural components in organic electronic devices with a focus on potential applications in biotechnology and medicine. PMID:20607127

  8. Regulatory affairs for biomaterials and medical devices

    Amato, Stephen F; Amato, B

    2014-01-01

    All biomaterials and medical devices are subject to a long list of regulatory practises and policies which must be adhered to in order to receive clearance. This book provides readers with information on the systems in place in the USA and the rest of the world. Chapters focus on a series of procedures and policies including topics such as commercialization, clinical development, general good practise manufacturing and post market surveillance.Addresses global regulations and regulatory issues surrounding biomaterials and medical devicesEspecially useful for smaller co

  9. Facile design of biomaterials by 'click' chemistry

    Hvilsted, Søren

    2012-01-01

    chemistry is elaborated. The present state of creating functional and biologically active surfaces by click chemistry is presented. Finally, conducting surfaces based on an azide‐functionalized polymer with prospective biological sensor potential are introduced. Copyright © 2012 Society of Chemical Industry......The advent of the so‐called ‘click chemistry’ a decade ago has significantly improved the chemical toolbox for producing novel biomaterials. This review focuses primarily on the application of Cu(I)‐catalysed azide–alkyne 1,3‐cycloadditon in the preparation of numerous, diverse biomaterials and...

  10. Sustainable Biomaterials: Current Trends, Challenges and Applications.

    Kumar Gupta, Girish; De, Sudipta; Franco, Ana; Balu, Alina Mariana; Luque, Rafael

    2015-01-01

    Biomaterials and sustainable resources are two complementary terms supporting the development of new sustainable emerging processes. In this context, many interdisciplinary approaches including biomass waste valorization and proper usage of green technologies, etc., were brought forward to tackle future challenges pertaining to declining fossil resources, energy conservation, and related environmental issues. The implementation of these approaches impels its potential effect on the economy of particular countries and also reduces unnecessary overburden on the environment. This contribution aims to provide an overview of some of the most recent trends, challenges, and applications in the field of biomaterials derived from sustainable resources. PMID:26729083

  11. Sustainable Biomaterials: Current Trends, Challenges and Applications

    Girish Kumar Gupta

    2015-12-01

    Full Text Available Biomaterials and sustainable resources are two complementary terms supporting the development of new sustainable emerging processes. In this context, many interdisciplinary approaches including biomass waste valorization and proper usage of green technologies, etc., were brought forward to tackle future challenges pertaining to declining fossil resources, energy conservation, and related environmental issues. The implementation of these approaches impels its potential effect on the economy of particular countries and also reduces unnecessary overburden on the environment. This contribution aims to provide an overview of some of the most recent trends, challenges, and applications in the field of biomaterials derived from sustainable resources.

  12. Radiation processing for the preparation of biomaterials and polymer electrolytes

    It is known that a radiation processing of polymeric materials has some unique advantages over other chemical and physical processing. For example, the use of toxic chemicals and strict temperature/moisture controls may not be needed during a radiation processing. Furthermore, the shape distortion of a product can be minimized during a radiation curing process. Since sterilization can also be incorporated in the process, a radiation processing could be efficient to manufacture bio material and medical products. In this presentation, our recent research outcomes in the fields of a radiation processing for biomaterials and polymer electrolytes carried out at the Korea Atomic Energy Research Institute (KAERI) are presented. In the field of a bio material production, two radiation sources, Co-60 gamma ray and electron beam are generally utilized to induce a crosslinking of natural or biocompatible synthetic polymers for the preparation of biomaterials, more specifically hydrogels. In this process, an extra process such as a removal process of toxic chemicals and a sterilization process are not necessary. Hydrogels for a wound treatment, ato pic dermatitis treatment, tissue scaffolds, and post-surgical anti-adhesion barriers have been developed or being developed by our research institute. The preparation of polymer electrolytes such as fuel cell membranes and lithium battery separators are also very attractive research fields using a radiation processing. Commercial polymer membranes such as fluoropolymer and polyethylene can be modified by a radiation induced grafting and/or crosslinking process to introduce desired functionalities onto the membranes for a specific purpose. In our research institute, these radiation-treated membranes for a specific purpose. In our research institute, these radiation-treated membranes have been successfully utilized to prepare fuel cell membranes and lithium battery separators with higher ion conductivities and desired mechanical

  13. Surface modification and endothelialization of biomaterials as potential scaffolds for vascular tissue engineering applications.

    Ren, Xiangkui; Feng, Yakai; Guo, Jintang; Wang, Haixia; Li, Qian; Yang, Jing; Hao, Xuefang; Lv, Juan; Ma, Nan; Li, Wenzhong

    2015-08-01

    Surface modification and endothelialization of vascular biomaterials are common approaches that are used to both resist the nonspecific adhesion of proteins and improve the hemocompatibility and long-term patency of artificial vascular grafts. Surface modification of vascular grafts using hydrophilic poly(ethylene glycol), zwitterionic polymers, heparin or other bioactive molecules can efficiently enhance hemocompatibility, and consequently prevent thrombosis on artificial vascular grafts. However, these modified surfaces may be excessively hydrophilic, which limits initial vascular endothelial cell adhesion and formation of a confluent endothelial lining. Therefore, the improvement of endothelialization on these grafts by chemical modification with specific peptides and genes is now arousing more and more interest. Several active peptides, such as RGD, CAG, REDV and YIGSR, can be specifically recognized by endothelial cells. Consequently, graft surfaces that are modified by these peptides can exhibit targeting selectivity for the adhesion of endothelial cells, and genes can be delivered by targeting carriers to specific tissues to enhance the promotion and regeneration of blood vessels. These methods could effectively accelerate selective endothelial cell recruitment and functional endothelialization. In this review, recent developments in the surface modification and endothelialization of biomaterials in vascular tissue engineering are summarized. Both gene engineering and targeting ligand immobilization are promising methods to improve the clinical outcome of artificial vascular grafts. PMID:26023741

  14. Amine-functionalized polypyrrole: Inherently cell adhesive conducting polymer.

    Lee, Jae Y; Schmidt, Christine E

    2015-06-01

    Electrically conducting polymers (CPs) have been recognized as novel biomaterials that can electrically communicate with biological systems. For their tissue engineering applications, CPs have been modified to promote cell adhesion for improved interactions between biomaterials and cells/tissues. Conventional approaches to improve cell adhesion involve the surface modification of CPs with biomolecules, such as physical adsorption of cell adhesive proteins and polycationic polymers, or their chemical immobilization; however, these approaches require additional multiple modification steps with expensive biomolecules. In this study, as a simple and effective alternative to such additional biomolecule treatment, we synthesized amine-functionalized polypyrrole (APPy) that inherently presents cell adhesion-supporting positive charges under physiological conditions. The synthesized APPy provides electrical activity in a moderate range and a hydrophilic surface compared to regular polypyrrole (PPy) homopolymers. Under both serum and serum-free conditions, APPy exhibited superior attachment of human dermal fibroblasts and Schwann cells compared to PPy homopolymer controls. Moreover, Schwann cell adhesion onto the APPy copolymer was at least similar to that on poly-l-lysine treated PPy controls. Our results indicate that amine-functionalized CP substrates will be useful to achieve good cell adhesion and potentially electrically stimulate various cells. In addition, amine functionality present on CPs can further serve as a novel and flexible platform to chemically tether various bioactive molecules, such as growth factors, antibodies, and chemical drugs. PMID:25294089

  15. ICTAS announces thrust on nano-biomaterials

    Nystrom, Lynn A.

    2007-01-01

    Four innovative interdisciplinary programs connecting nanotechnology and health care are receiving initial seed funding from Virginia Tech's Institute for Critical Technology and Applied Science (ICTAS). The four areas will come under one of the designated primary research thrusts within ICTAS, "Nano-Biomaterials for the Delivery of Therapeutic and Diagnostic Agents."

  16. Application of mushroom chitosans in medical biomaterials

    Beran, M.; Urban, M.; Adámek, L.; Jandušík, L.; Spěváček, Jiří

    Snowbird, Utah : Keystone Symposia, 2007. s. 49. [Keystone Symposia: Tissue Engineering and Development Biology. 12.04.2007-17.04.2007, Snowbird] R&D Projects: GA MŠk 2B06173 Institutional research plan: CEZ:AV0Z40500505 Keywords : mushrooms * chitosan * biomaterials Subject RIV: EI - Biotechnology ; Bionics

  17. Biomaterials for the Treatment of Alzheimer's Disease.

    Hadavi, Darya; Poot, André A

    2016-01-01

    Alzheimer's disease (AD) as a progressive and fatal neurodegenerative disease represents a huge unmet need for treatment. The low efficacy of current treatment methods is not only due to low drug potency but also due to the presence of various obstacles in the delivery routes. One of the main barriers is the blood-brain barrier. The increasing prevalence of AD and the low efficacy of current therapies have increased the amount of research on unraveling of disease pathways and development of treatment strategies. One of the interesting areas for the latter subject is biomaterials and their applications. This interest originates from the fact that biomaterials are very useful for the delivery of therapeutic agents, such as drugs, proteins, and/or cells, in order to treat diseases and regenerate tissues. Recently, manufacturing of nano-sized delivery systems has increased the efficacy and delivery potential of biomaterials. In this article, we review the latest developments with regard to the use of biomaterials for the treatment of AD, including nanoparticles and liposomes for delivery of therapeutic compounds and scaffolds for cell delivery strategies. PMID:27379232

  18. Silk film biomaterials for ocular surface repair

    Lawrence, Brian David

    Current biomaterial approaches for repairing the cornea's ocular surface upon injury are partially effective due to inherent material limitations. As a result there is a need to expand the biomaterial options available for use in the eye, which in turn will help to expand new clinical innovations and technology development. The studies illustrated here are a collection of work to further characterize silk film biomaterials for use on the ocular surface. Silk films were produced from regenerated fibroin protein solution derived from the Bombyx mori silkworm cocoon. Methods of silk film processing and production were developed to produce consistent biomaterials for in vitro and in vivo evaluation. A wide range of experiments was undertaken that spanned from in vitro silk film material characterization to in vivo evaluation. It was found that a variety of silk film properties could be controlled through a water-annealing process. Silk films were then generated that could be use in vitro to produce stratified corneal epithelial cell sheets comparable to tissue grown on the clinical standard substrate of amniotic membrane. This understanding was translated to produce a silk film design that enhanced corneal healing in vivo on a rabbit injury model. Further work produced silk films with varying surface topographies that were used as a simplified analog to the corneal basement membrane surface in vitro. These studies demonstrated that silk film surface topography is capable of directing corneal epithelial cell attachment, growth, and migration response. Most notably epithelial tissue development was controllably directed by the presence of the silk surface topography through increasing cell sheet migration efficiency at the individual cellular level. Taken together, the presented findings represent a comprehensive characterization of silk film biomaterials for use in ocular surface reconstruction, and indicate their utility as a potential material choice in the

  19. Adhesion and Cohesion

    J. Anthony von Fraunhofer

    2012-01-01

    Full Text Available The phenomena of adhesion and cohesion are reviewed and discussed with particular reference to dentistry. This review considers the forces involved in cohesion and adhesion together with the mechanisms of adhesion and the underlying molecular processes involved in bonding of dissimilar materials. The forces involved in surface tension, surface wetting, chemical adhesion, dispersive adhesion, diffusive adhesion, and mechanical adhesion are reviewed in detail and examples relevant to adhesive dentistry and bonding are given. Substrate surface chemistry and its influence on adhesion, together with the properties of adhesive materials, are evaluated. The underlying mechanisms involved in adhesion failure are covered. The relevance of the adhesion zone and its importance with regard to adhesive dentistry and bonding to enamel and dentin is discussed.

  20. Effect of biomaterial properties on bone healing in a rabbit tooth extraction socket model.

    Fisher, John P; Lalani, Zahid; Bossano, Carla M; Brey, Eric M; Demian, Nagi; Johnston, Carol M; Dean, David; Jansen, John A; Wong, Mark E K; Mikos, Antonios G

    2004-03-01

    In this work we sought to understand the effect of biomaterial properties upon healing bone tissue. We hypothesized that a hydrophilic polymer gel implanted into a bone tissue defect would impede the healing process owing to the biomaterial's prevention of protein adsorption and thus cell adhesion. To test this hypothesis, healing bone was investigated within a rabbit incisor extraction socket, a subcritical size bone defect that resists significant soft tissue invasion by virtue of its conformity. After removal of the incisor teeth, one tooth socket was left as an empty control, one was filled with crosslinked polymer networks formed from the hydrophobic polymer poly(propylene fumarate) (PPF), and one was filled with a hydrogel formed from the hydrophilic oligomer oligo(poly(ethylene glycol) fumarate) (OPF). At five different times (4 days as well as 1, 2, 4, and 8 weeks), jaw bone specimens containing the tooth sockets were removed. We analyzed bone healing by histomorphometrical analysis of hematoxylin and eosin stained sections as well as immunohistochemically stained sections. The proposed hypothesis, that a hydrophilic material would hinder bone healing, was supported by the histomorphometrical results. In addition, the immunohistochemical results reflect molecular signaling indicative of the early invasion of platelets, the vascularization of wound-healing tissue, the differentiation of migrating progenitor cells, and the formation and remodeling of bone tissue. Finally, the results emphasize the need to consider biomaterial properties and their differing effects upon endogenous growth factors, and thus bone healing, during the development of tissue engineering devices. PMID:14762922

  1. A Tubular Biomaterial Construct Exhibiting a Negative Poisson's Ratio.

    Jin Woo Lee

    Full Text Available Developing functional small-diameter vascular grafts is an important objective in tissue engineering research. In this study, we address the problem of compliance mismatch by designing and developing a 3D tubular construct that has a negative Poisson's ratio νxy (NPR. NPR constructs have the unique ability to expand transversely when pulled axially, thereby resulting in a highly-compliant tubular construct. In this work, we used projection stereolithography to 3D-print a planar NPR sheet composed of photosensitive poly(ethylene glycol diacrylate biomaterial. We used a step-lithography exposure and a stitch process to scale up the projection printing process, and used the cut-missing rib unit design to develop a centimeter-scale NPR sheet, which was rolled up to form a tubular construct. The constructs had Poisson's ratios of -0.6 ≤ νxy ≤ -0.1. The NPR construct also supports higher cellular adhesion than does the construct that has positive νxy. Our NPR design offers a significant advance in the development of highly-compliant vascular grafts.

  2. A Tubular Biomaterial Construct Exhibiting a Negative Poisson's Ratio.

    Lee, Jin Woo; Soman, Pranav; Park, Jeong Hun; Chen, Shaochen; Cho, Dong-Woo

    2016-01-01

    Developing functional small-diameter vascular grafts is an important objective in tissue engineering research. In this study, we address the problem of compliance mismatch by designing and developing a 3D tubular construct that has a negative Poisson's ratio νxy (NPR). NPR constructs have the unique ability to expand transversely when pulled axially, thereby resulting in a highly-compliant tubular construct. In this work, we used projection stereolithography to 3D-print a planar NPR sheet composed of photosensitive poly(ethylene) glycol diacrylate biomaterial. We used a step-lithography exposure and a stitch process to scale up the projection printing process, and used the cut-missing rib unit design to develop a centimeter-scale NPR sheet, which was rolled up to form a tubular construct. The constructs had Poisson's ratios of -0.6 ≤ νxy ≤ -0.1. The NPR construct also supports higher cellular adhesion than does the construct that has positive νxy. Our NPR design offers a significant advance in the development of highly-compliant vascular grafts. PMID:27232181

  3. Synthesis and morphological characterization of block copolymers for improved biomaterials

    Biocompatible polymers are known to act as scaffolds for the regeneration and growth of bone. Block copolymers are of interest as scaffold materials because a number of the blocks are biocompatible, and their nanostructure is easily tunable with synthetic techniques. In this paper, we report the synthesis of a novel class of biomaterials from block copolymers containing a hydrophobic block of methyl methacrylate and a hydrophilic block of either acrylic acid, dimethyl acrylamide, or 2-hydroxyethyl methacrylate. The block copolymers were synthesized using a combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and click chemistry. Since the surface morphology is critical for successful cell growth, atomic force microscopy (AFM) studies were conducted for selected block copolymers. The topography, phase angle and friction maps were obtained in dry and physiological buffer environments to study the morphology. Results of AFM imaging identified the presence of polymer domains corresponding to the copolymer components. The distribution of nanoscale features in these block copolymers is comparable to those found on other surfaces that exhibit favorable cell adhesion and growth. In physiological buffer medium, the hydrophilic component of the block copolymer (acrylic acid or hydroxyethyl methacrylate) appears to be present in greater amounts on the surface as a consequence of water absorption and swelling.

  4. Synthesis and morphological characterization of block copolymers for improved biomaterials

    Schricker, Scott, E-mail: Schricker.1@osu.edu [Restorative and Prosthetic Dentistry Section, College of Dentistry, The Ohio State University, Columbus, OH 43210 (United States); Palacio, Manuel [Nanoprobe Laboratory for Bio- and Nanotechnology and Biomimetics, The Ohio State University, Columbus, OH 43210 (United States); Thirumamagal, B.T.S. [Restorative and Prosthetic Dentistry Section, College of Dentistry, The Ohio State University, Columbus, OH 43210 (United States); Bhushan, Bharat [Nanoprobe Laboratory for Bio- and Nanotechnology and Biomimetics, The Ohio State University, Columbus, OH 43210 (United States)

    2010-05-15

    Biocompatible polymers are known to act as scaffolds for the regeneration and growth of bone. Block copolymers are of interest as scaffold materials because a number of the blocks are biocompatible, and their nanostructure is easily tunable with synthetic techniques. In this paper, we report the synthesis of a novel class of biomaterials from block copolymers containing a hydrophobic block of methyl methacrylate and a hydrophilic block of either acrylic acid, dimethyl acrylamide, or 2-hydroxyethyl methacrylate. The block copolymers were synthesized using a combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and click chemistry. Since the surface morphology is critical for successful cell growth, atomic force microscopy (AFM) studies were conducted for selected block copolymers. The topography, phase angle and friction maps were obtained in dry and physiological buffer environments to study the morphology. Results of AFM imaging identified the presence of polymer domains corresponding to the copolymer components. The distribution of nanoscale features in these block copolymers is comparable to those found on other surfaces that exhibit favorable cell adhesion and growth. In physiological buffer medium, the hydrophilic component of the block copolymer (acrylic acid or hydroxyethyl methacrylate) appears to be present in greater amounts on the surface as a consequence of water absorption and swelling.

  5. Atmospheric Microplasma Application for Surface Modification of Biomaterials

    Shimizu, Kazuo; Fukunaga, Hodaka; Tatematsu, Shigeki; Blajan, Marius

    2012-11-01

    Atmospheric microplasma has been intensively studied for applications in various fields, since in this technology the generated field is only 1 kV (approx) under atmospheric pressure and a dielectric barrier discharge gap of 10 to 100 µm. A low discharge voltage atmospheric plasma process is an economical and effective solution for various applications such as indoor air control including sterilization, odor removal, and surface treatment, and would be suitable for medical applications in the field of plasma life sciences. In this paper, we present the application of microplasma for the surface treatment of materials used in medical fields. Moreover, a biomaterial composed of L-lactic acid is used in experiments, which can be biodecomposed in the human body after medical operations. The surface modification process was carried out with active species generated between the microplasma electrodes, which were observed by emission spectrometry. Microplasma treatment of a polymer sheet using Ar as the process gas decreased the contact angle of a water droplet at the surface of the polymer from 78.3 to 45.6° in 10 s, indicating improved surface adhesive characteristics.

  6. Improving biocompatibility by controlling protein adsorption: Modification and design of biomaterials using poly(ethylene glycol) microgels and microspheres

    Scott, Evan Alexander

    2009-12-01

    Guided by the clinical needs of patients and developments in biology and materials science, the primary focus of the biomaterials field remains at the solid/liquid interface between biomaterial surfaces and biological fluids. For blood-contacting devices, biological responses are initially elicited and directed by proteins that adsorb from this multicomponent solution to form thin films on their surfaces. The identity, conformation, and quantity of adsorbed proteins are related to the properties of a material's surface. For example, hydrophobic surfaces tend to be thrombotic via interactions between platelets and adsorbed fibrinogen, while surface-activation of specific enzymes initiates the coagulation cascade on hydrophilic surfaces. The objective of this thesis is to improve the design of biomaterials through the analysis and control of adsorbing protein layers. This goal is approached through three separate strategies. First, a proteomics-based methodology is presented for the assessment of protein conformation at the residue level after adsorption to biomaterial surfaces. A quantitative mass spectrometric technique is additionally suggested for the identification and quantification of proteins within adsorbed protein layers. Second, a method is described for the covalent attachment of poly(ethylene glycol) (PEG)-based hydrogel coatings onto biomaterials surfaces for the minimization of protein adsorption. The coatings are applied using partially crosslinked PEG solutions containing polymer and protein oligomers and microgels that can be designed to control cell adhesion. Finally, a modular strategy is proposed for the assembly of bioactive PEG-based hydrogel scaffolds. This was accomplished using novel PEG microspheres with diverse characteristics that individually contribute to the ability of the scaffold to direct cellular infiltration. The methodologies proposed by this thesis contribute to the recent shift in biomaterials and tissue engineering strategies

  7. New nanostructured biomaterials for regenerative medicine

    A. Sgambato

    2016-01-01

    Innovative approaches in tissue engineering and regenerative medicine based on decellularized extracellular matrix (ECM) scaffolds and tissues are quickly growing. ECM proteins are particularly adequate toward tissue regeneration applications, since they are natural biomaterials that can be bio-activated with signalling molecules able to influence cell fate, driving cell responses and tissue regeneration. Indeed, it is well recognized that cells perceive and respond to their microenvironment;...

  8. Biomaterials in Maxillofacial Surgery: Membranes and Grafts

    Rodella, Luigi F.; Favero, Gaia; Labanca, Mauro

    2011-01-01

    Today, significant differences in the use of biomaterials (membranes and grafts) of animal or synthetic origin have yet to be reported. Nevertheless, some evidences suggest that synthetic materials have a lower risk of disease transmission. This review aims to assess the available informations on regenerative bone technique using reasorbable membranes and bone grafts. In particular, biocompatibility, immunological response, tissue reaction, reabsorption time and histological features of mater...

  9. [The future of biomaterials in urology].

    Grise, Philippe

    2002-12-01

    The fields of application of implanted biomaterials will continue to grow, ranging from the use of catheters and slings for the genitourinary tract, to the production of tissues and organs. The scale of research has changed over recent years, passing from a macroscopic view to a microscopic view, resulting in a change from mechanical devices, such as prostheses, catheters and slings to the cellular unit and more particularly in vitro cell cultures. New techniques, such as gene therapy and cell reconstruction have been recently introduced into the field of urology. Prospective biocompatibility studies must be conducted to establish appropriate biocompatibility standards adapted to new materials. The development of these new materials required a multidisciplinary approach involving engineers, biologists and physicists. It must be conducted in specialized centres skilled in biocompatibility research and in close collaboration with a basic bioscience and clinical practice. In the future, synthetic biomaterials will have an almost unlimited range of mechanical properties allowing much more specific applications. Another improvement of materials will concern a reduction of the risk of infection, erosion, mineral deposits, migration of particles, secondary reactions, and finally improved durability. However, the long-term properties of synthetic materials will probably not be as good as those of natural or almost natural biomaterials derived from biotechnology by tissue engineering. PMID:12545647

  10. Reconstituted Keratin Biomaterial with Enhanced Ductility

    Halleh Atri

    2015-11-01

    Full Text Available Nowadays the waste from protein fibres represents an important renewable source for a new generation of biomaterials and promising competitors for carbohydrate based biomaterials. Regenerated keratin biomaterials are biodegradable in vivo and in vitro, biocompatible, and support cell attachment and proliferation; however, their major drawback has been their weak mechanical properties such as ductility. The following study was conducted in an attempt to improve the ductility of reconstituted keratin films obtained from Australian merino wool fibres. Keratin was extracted from wool fibres according to an established protocol proposed by Yamauchi, and then dialyzed and desalted by multiple diafiltration wash cycles. The resulting keratin film was transparent, biodegradable, and, opposite to its predecessors, mechanically durable, possessing a Young modulus about 12.5 MPa with 35% extensibility. The polypeptide chains were found to rearrange themselves in the β-sheet state in this keratin film, which was shown to be semi-crystalline. This film, unlike its predecessors, did not support human cell proliferation. These properties of the diafiltered keratin film have led us to think that diafiltration resulted in producing a totally new keratin film, which is envisaged to find applications in various areas.

  11. Bacterial adhesion forces with substratum surfaces and the susceptibility of biofilms to antibiotics

    Muszanska, L.H.; Nejadnik, M.R.; Chen, Y.; Heuvel, van den E.R.; Busscher, H.J.; Mei, van der H.C.; Norde, W.

    2012-01-01

    Biofilms causing biomaterial-associated infection resist antibiotic treatment and usually necessitate the replacement of infected implants. Here we relate bacterial adhesion forces and the antibiotic susceptibility of biofilms on uncoated and polymer brush-coated silicone rubber. Nine strains of Sta

  12. Advanced adhesives in electronics

    Bailey, C

    2011-01-01

    Adhesives are widely used in the manufacture of electronic devices to act as passive and active components. Recently there has been considerable interest in the use of conductive adhesives. This book reviews key types of conductive adhesives, processing methods, properties and the way they can be modelled as well as potential applications.$bAdhesives for electronic applications serve important functional and structural purposes in electronic components and packaging, and have developed significantly over the last few decades. Advanced adhesives in electronics reviews recent developments in adhesive joining technology, processing and properties. The book opens with an introduction to adhesive joining technology for electronics. Part one goes on to cover different types of adhesive used in electronic systems, including thermally conductive adhesives, isotropic and anisotropic conductive adhesives and underfill adhesives for flip-chip applications. Part two focuses on the properties and processing of electronic ...

  13. Biomimetic oligosaccharide and peptide surfactant polymers designed for cardiovascular biomaterials

    Ruegsegger, Mark Andrew

    A common problem associated with cardiovascular devices is surface induced thrombosis initiated by the rapid, non-specific adsorption of plasma proteins onto the biomaterial surface. Control of the initial protein adsorption is crucial to achieve the desired longevity of the implanted biomaterial. The cell membrane glycocalyx acts as a non-thrombogenic interface through passive (dense oligosaccharide structures) and active (ligand/receptor interactions) mechanisms. This thesis is designed to investigate biomimicry of the cell glycocalyx to minimize non-specific protein adsorption and promote specific ligand/receptor interactions. Biomimetic macromolecules were designed through the molecular-scale engineering of polymer surfactants, utilizing a poly(vinyl amine) (PVAm) backbone to which hydrophilic (dextran, maltose, peptide) and hydrophobic alkyl (hexanoyl or hexanal) chains are simultaneously attached. The structure was controlled through the molar feed ratio of hydrophobic-to-hydrophilic groups, which also provided control of the solution and surface-active properties. To mimic passive properties, a series of oligomaltose surfactants were synthesized with increasing saccharide length (n = 2, 7, 15 where n is number of glucose units) to investigate the effect of coating height on protein adsorption. The surfactants were characterized by infra red (IR) and nuclear magnetic resonance (NMR) spectroscopies for structural properties and atomic force microscopy (AFM) and contact angle goniometry for surface activity. Protein adsorption under dynamic flow (5 dyn/cm2) was reduced by 85%--95% over the bare hydrophobic substrate; platelet adhesion dropped by ˜80% compared to glass. Peptide ligands were incorporated into the oligosaccharide surfactant to promote functional activity of the passive coating. The surfactants were synthesized to contain 0%, 25%, 50%, 75%, and 100% peptide ligand density and were stable on hydrophobic surfaces. The peptide surface density was

  14. Analysis of the strengthening and toughening of a biomaterial interface

    SONG; Fan

    2001-01-01

    [1]Currey, J. D., Mechanical properties of mother of pearl in tension, Proc. R. Soc. Lond. B, 1977, 196: 443—463.[2]Jackson, A. P., Vincent, J. F. V., Turner, R. M., The mechanical design of nacre, Proc. R. Soc. Lond. B., 1988, 234: 415—440.[3]Wang, R. Z., Wen, H. B., Cui, F. Z. et al., Observations of damage morphologies in nacre during deformation and fracture, J. Mater. Sci., 1995, 30: 2299—2304.[4]Smith, B. L., Schaffer, T. E., Viani, M. et al., Molecular mechanistic origin of the toughness of natural adhesives, fibres and composites, Nature, 1999, 399: 761—763.[5]Addadi, L., Weiner, S., A pavement of pearl, Nature, 1997, 389: 912—915.[6]Schaffer,T. E., Ionescu-Zantti, C., Fritz, M. et al., Does abalone nacre form by heteroepiaxial nucleation or by growth through mineral bridges? Chem. Mater., 1997, 9: 1731—1740.[7]Vincent, J. F. V., Structural Biomaterials, New York; The Macmillan Press Ltd, 1982.[8]Song, F., Bai, Y. L., Effects of mineral bridges on the mechanical properties of nacre, Acta Mechanica Solida Sinica (in Chinese), 2000, 21(Special Issue): 171—176.[9]Szuromi, P., Microstructural engineering of materials, Science, 1997, 277: 1183—1183.[10]Heuer, A. H., Fink, D. J., Laraia, J. L. et al., Innovative materials processing strategies: a biomimetic approach, Science, 1992, 255: 1098—1105.[11]Stupp, S. I., Braun, P. V., Molecular manipulation of microstructure: biomaterials, ceramics, and semiconductors, Science, 1997, 277: 1242—1248.[12]Watabe, N., Crystal growth of calcium carbonate in the invertebrates, Prog. Crystal Growth Charact., 1981, 4: 99—147.[13]Clegg, W. J., Kendall, K., Alford, N. M. et al., A simple way to make tough ceramics, Nature, 1990, 347: 455—457.[14]Jackson, A. P., Vincent, J. F. V., Briggs, D. et al., Application of surface analytical techniques to the study fracture surface of mother-of pearl, J. Mater. Science Letters, 1986, 5: 975—980.[15

  15. Adhesion in microelectronics

    Mittal, K L

    2014-01-01

    This comprehensive book will provide both fundamental and applied aspects of adhesion pertaining to microelectronics in a single and easily accessible source. Among the topics to be covered include; Various theories or mechanisms of adhesionSurface (physical or chemical) characterization of materials as it pertains to adhesionSurface cleaning as it pertains to adhesionWays to improve adhesionUnraveling of interfacial interactions using an array of pertinent techniquesCharacterization of interfaces / interphasesPolymer-polymer adhesionMetal-polymer adhesion  (metallized polymers)Polymer adhesi

  16. The case study of biomaterials and biominerals

    Del Hoyo Martínez, Carmen

    2013-04-01

    The teaching of biomaterials as case study by on-line platform , susceptible to develop both individually and in groups, got different objectives proposed by the European Higher Education System, among which include: participate actively in the teaching-learning process by students, interpreting situations, adapt processes and solutions. It also improves oral and written communication, analytical skills and synthesis and also the ability to think critically. Biomaterials have their origin in biominerals. These are solid inorganic compounds of defined structure, consisting of molecular control mechanisms that operate in biological systems. Its main functions are: structural support, a reservoir of essential elements, sensors, mechanical protection and storage of toxic elements. Following the demand of materials compatible with certain functional systems of our body, developed biomaterials. Always meet the condition of biocompatibility. Should be tolerated by the body and do not provoke rejection. This involves a comprehensive study of physiological conditions and the anatomy of the body where a biomaterial has to be implemented. The possibility of generating new materials from biominerals has a major impact in medicine and other fields could reach as geology, construction, crystallography, etc. While the study of these issues is in its infancy today, can be viewed as an impact on the art and future technology. Planning case study that students would prepare its report for discussion in subgroups. Occurs then the pooling of individual analysis, joint case discussion and adoption by the subgroup of a consensual solution to the problem. The teacher as facilitator and coordinator of the final case analysis, sharing leads to group-wide class and said the unanimous decision reached by the students and gives his opinion on the resolution of the case. REFERENCES D.P. Ausubel. Psicología Educativa. Un punto de vista cognoscitivo. Trillas. Ed. 1983. E.W. Eisner. Procesos

  17. Biomaterials and tissue engineering in reconstructive surgery

    D F Williams

    2003-06-01

    This paper provides an account of the rationale for the development of implantable medical devices over the last half-century and explains the criteria that have controlled the selection of biomaterials for these critical applications. In spite of some good successes and excellent materials, there are still serious limitations to the performance of implants today, and the paper explains these limitations and develops this theme in order to describe the recent innovations in tissue engineering, which involves a different approach to reconstruction of the body.

  18. Atomic layer deposition of nanoporous biomaterials

    Roger J Narayan

    2010-03-01

    Full Text Available Due to its chemical stability, uniform pore size, and high pore density, nanoporous alumina is being investigated for use in biosensing, drug delivery, hemodialysis, and other medical applications. In recent work, we have examined the use of atomic layer deposition for coating the surfaces of nanoporous alumina membranes. Zinc oxide coatings were deposited on nanoporous alumina membranes using atomic layer deposition. The zinc oxide-coated nanoporous alumina membranes demonstrated antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. These results suggest that atomic layer deposition is an attractive technique for modifying the surfaces of nanoporous alumina membranes and other nanostructured biomaterials.

  19. Thermal Characterization of Adhesive

    Spomer, Ken A.

    1999-01-01

    The current Space Shuttle Reusable Solid Rocket Motor (RSRM) nozzle adhesive bond system is being replaced due to obsolescence. Down-selection and performance testing of the structural adhesives resulted in the selection of two candidate replacement adhesives, Resin Technology Group's Tiga 321 and 3M's EC2615XLW. This paper describes rocket motor testing of these two adhesives. Four forty-pound charge motors were fabricated in configurations that would allow side by side comparison testing of the candidate replacement adhesives and the current RSRM adhesives. The motors provided an environment where the thermal performance of adhesives in flame surface bondlines was compared. Results of the FPC testing show that: 1) The phenolic char depths on radial bond lines is approximately the same and vary depending on the position in the blast tube regardless of which adhesive was used; 2) The adhesive char depth of the candidate replacement adhesives is less than the char depth of the current adhesives; 3) The heat-affected depth of the candidate replacement adhesives is less than the heat-affected depth of the current adhesives; and 4) The ablation rates for both replacement adhesives are slower than that of the current adhesives.

  20. Biomaterials for integration with 3-D bioprinting.

    Skardal, Aleksander; Atala, Anthony

    2015-03-01

    Bioprinting has emerged in recent years as an attractive method for creating 3-D tissues and organs in the laboratory, and therefore is a promising technology in a number of regenerative medicine applications. It has the potential to (i) create fully functional replacements for damaged tissues in patients, and (ii) rapidly fabricate small-sized human-based tissue models, or organoids, for diagnostics, pathology modeling, and drug development. A number of bioprinting modalities have been explored, including cellular inkjet printing, extrusion-based technologies, soft lithography, and laser-induced forward transfer. Despite the innovation of each of these technologies, successful implementation of bioprinting relies heavily on integration with compatible biomaterials that are responsible for supporting the cellular components during and after biofabrication, and that are compatible with the bioprinting device requirements. In this review, we will evaluate a variety of biomaterials, such as curable synthetic polymers, synthetic gels, and naturally derived hydrogels. Specifically we will describe how they are integrated with the bioprinting technologies above to generate bioprinted constructs with practical application in medicine. PMID:25476164

  1. Biomaterials and Magnetic fields for Cancer Therapy

    Ramachandran, Narayanan; Mazuruk, Konstanty

    2003-01-01

    The field of biomaterials has emerged as an important topic in the purview of NASA s new vision of research activities in the Microgravity Research Division. Although this area has an extensive track record in the medical field as borne out by the routine use of polymeric sutures, implant devices, and prosthetics, novel applications such as tissue engineering, artificial heart valves and controlled drug delivery are beginning to be developed. Besides the medical field, biomaterials and bio-inspired technologies are finding use in a host of emerging interdisciplinary fields such as self-healing and self-assembling structures, biosensors, fuel systems etc. The field of magnetic fluid technology has several potential applications in medicine. One of the emerging fields is the area of controlled drug delivery, which has seen its evolution from the basic oral delivery system to pulmonary to transdermal to direct inoculations. In cancer treatment by chemotherapy for example, targeted and controlled drug delivery has received vast scrutiny and substantial research and development effort, due to the high potency of the drugs involved and the resulting requirement to keep the exposure of the drugs to surrounding healthy tissue to a minimum. The use of magnetic particles in conjunction with a static magnetic field allows smart targeting and retention of the particles at a desired site within the body with the material transport provided by blood perfusion. Once so located, the therapeutical aspect (radiation, chemotherapy, hyperthermia, etc.) of the treatment, now highly localized, can be implemented.

  2. Surface characterization of collagen/elastin based biomaterials for tissue regeneration

    Skopinska-Wisniewska, J.; Sionkowska, A.; Kaminska, A.; Kaznica, A.; Jachimiak, R.; Drewa, T.

    2009-07-01

    Collagen and elastin are the main proteins of extracellular matrix. Collagen plays a crucial role in tensile strength of tissues, whereas elastin provides resilience to many organs. Both biopolymers are readily available and biocompatible. These properties point out that collagen and elastin are good components of materials for many potential medical applications. The surface properties of biomaterials play an important role in biomedicine as the majority of biological reactions occur on the surface of implanted materials. One of the methods of surface modification is UV-irradiation. The exposition of the biomaterial on ultraviolet light can alterate surface properties of the materials, their chemical stability, swelling properties and mechanical properties as well. The aim of our work was to study the surface properties and biocompatibility of new collagen/elastin based biomaterials and consideration of the influence of ultraviolet light on these properties. The surface properties of collagen/elastin based biomaterials modified by UV-irradiation were studied using the technique of atomic force microscopy (AFM) and contact angle measurements. On the basis of the results the surface free energy and its polar component was calculated using Owens-Wendt method. To assess the biological performance of films based on collagen, elastin and their blends, the response of 3T3 cell was investigated. It was found that the surface of collagen/elastin film is enriched in less polar component - collagen. Exposition on UV light increases polarity of collagen/elastin based films, due to photooxidation process. The AFM images have shown that topography and roughness of the materials had been also affected by UV-irradiation. The changes in surface properties influence on interaction between the material's surface and cells. The investigation of 3T3 cells grown on films based on collagen, elastin and their blends, leads to the conclusion that higher content of elastin in biomaterial

  3. Surface characterization of collagen/elastin based biomaterials for tissue regeneration

    Collagen and elastin are the main proteins of extracellular matrix. Collagen plays a crucial role in tensile strength of tissues, whereas elastin provides resilience to many organs. Both biopolymers are readily available and biocompatible. These properties point out that collagen and elastin are good components of materials for many potential medical applications. The surface properties of biomaterials play an important role in biomedicine as the majority of biological reactions occur on the surface of implanted materials. One of the methods of surface modification is UV-irradiation. The exposition of the biomaterial on ultraviolet light can alterate surface properties of the materials, their chemical stability, swelling properties and mechanical properties as well. The aim of our work was to study the surface properties and biocompatibility of new collagen/elastin based biomaterials and consideration of the influence of ultraviolet light on these properties. The surface properties of collagen/elastin based biomaterials modified by UV-irradiation were studied using the technique of atomic force microscopy (AFM) and contact angle measurements. On the basis of the results the surface free energy and its polar component was calculated using Owens-Wendt method. To assess the biological performance of films based on collagen, elastin and their blends, the response of 3T3 cell was investigated. It was found that the surface of collagen/elastin film is enriched in less polar component - collagen. Exposition on UV light increases polarity of collagen/elastin based films, due to photooxidation process. The AFM images have shown that topography and roughness of the materials had been also affected by UV-irradiation. The changes in surface properties influence on interaction between the material's surface and cells. The investigation of 3T3 cells grown on films based on collagen, elastin and their blends, leads to the conclusion that higher content of elastin in biomaterial

  4. Innate Immunity and Biomaterials at the Nexus: Friends or Foes

    Susan N. Christo

    2015-01-01

    Full Text Available Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical “antigen.” In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a “combined” immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

  5. Repairing Femoral Fractures: A Model Lesson in Biomaterial Science

    Sakakeeny, Jarred

    2006-01-01

    Biomaterial science is a rapidly growing field that has scientists and doctors searching for new ways to repair the body. A merger between medicine and engineering, biomaterials can be complex subject matter, and it can certainly capture the minds of middle school students. In the lesson described in this article, seventh graders generally learn…

  6. Novel nanostructured biomaterials: implications for coronary stent thrombosis

    Karagkiozaki V

    2012-12-01

    Full Text Available Varvara Karagkiozaki,1,2 Panagiotis G Karagiannidis,1 Nikolaos Kalfagiannis,1 Paraskevi Kavatzikidou,1 Panagiotis Patsalas,3 Despoina Georgiou,1 Stergios Logothetidis11Lab for Thin Films – Nanosystems and Nanometrology (LTFN, Physics Department, Aristotle University of Thessaloniki, Thessaloniki, 2AHEPA Hospital, Aristotle University of Thessaloniki, Thessaloniki, 3Department of Materials Science and Engineering, University of Ioannina, Ioannina, Epirus, GreeceBackground: Nanomedicine has the potential to revolutionize medicine and help clinicians to treat cardiovascular disease through the improvement of stents. Advanced nanomaterials and tools for monitoring cell–material interactions will aid in inhibiting stent thrombosis. Although titanium boron nitride (TiBN, titanium diboride, and carbon nanotube (CNT thin films are emerging materials in the biomaterial field, the effect of their surface properties on platelet adhesion is relatively unexplored.Objective and methods: In this study, novel nanomaterials made of amorphous carbon, CNTs, titanium diboride, and TiBN were grown by vacuum deposition techniques to assess their role as potential stent coatings. Platelet response towards the nanostructured surfaces of the samples was analyzed in line with their physicochemical properties. As the stent skeleton is formed mainly of stainless steel, this material was used as reference material. Platelet adhesion studies were carried out by atomic force microscopy and scanning electron microscopy observations. A cell viability study was performed to assess the cytocompatibility of all thin film groups for 24 hours with a standard immortalized cell line.Results: The nanotopographic features of material surface, stoichiometry, and wetting properties were found to be significant factors in dictating platelet behavior and cell viability. The TiBN films with higher nitrogen contents were less thrombogenic compared with the biased carbon films and control

  7. Platelet responses to dynamic biomaterial surfaces with different poly(ethylene glycol) and polyrotaxane molecular architectures constructed on gold substrates.

    Kakinoki, Sachiro; Yui, Nobuhiko; Yamaoka, Tetsuji

    2013-11-01

    Four different dynamic biomaterial surfaces with different molecular architectures were prepared using two hydrophilic polymers: poly(ethylene glycol) and polyrotaxanes containing α-cyclodextrin. Either one or both terminals of the poly(ethylene glycol) or polyrotaxanes were immobilized onto a gold substrate via Au-S bonds, resulting in poly(ethylene glycol)-graft, polyrotaxanes-graft, poly(ethylene glycol)-loop, and polyrotaxanes-loop structures. Human platelet adhesion was suppressed more effectively on the graft surfaces than on the loop surfaces for both poly(ethylene glycol) and polyrotaxanes due to the high mobility of graft polymer chains with a free terminal. Moreover, the platelets adhered to the polyrotaxane surfaces much less than the poly(ethylene glycol) surfaces, possibly because of the mobile nature of the α-cyclodextrin molecules that were threaded on the poly(ethylene glycol) chain. Actin filament assembly in adherent platelets was also greatly prevented on the poly(ethylene glycol)/polyrotaxanes-graft surfaces in comparison with the corresponding loop surfaces. A clear correlation between the numbers and areas of adherent platelets on these surfaces suggests that platelet adhesion and activation were dominated by the platelet GPIIb/IIIa-adsorbed fibrinogen interaction. These results indicate that both of the different modes of dynamic features, sliding/rotation of α-cyclodextrin and polymer chain mobility, effectively suppressed platelet adhesion in spite of the similar hydrophilicity. This research affords a novel chemical strategy for designing hemocompatible biomaterial surfaces. PMID:23048065

  8. Understanding Marine Mussel Adhesion

    H. G. Silverman; F. F. Roberto

    2007-12-01

    In addition to identifying the proteins that have a role in underwater adhesion by marine mussels, research efforts have focused on identifying the genes responsible for the adhesive proteins, environmental factors that may influence protein production, and strategies for producing natural adhesives similar to the native mussel adhesive proteins. The production-scale availability of recombinant mussel adhesive proteins will enable researchers to formulate adhesives that are waterimpervious and ecologically safe and can bind materials ranging from glass, plastics, metals, and wood to materials, such as bone or teeth, biological organisms, and other chemicals or molecules. Unfortunately, as of yet scientists have been unable to duplicate the processes that marine mussels use to create adhesive structures. This study provides a background on adhesive proteins identified in the blue mussel, Mytilus edulis, and introduces our research interests and discusses the future for continued research related to mussel adhesion.

  9. Understanding marine mussel adhesion.

    Silverman, Heather G; Roberto, Francisco F

    2007-01-01

    In addition to identifying the proteins that have a role in underwater adhesion by marine mussels, research efforts have focused on identifying the genes responsible for the adhesive proteins, environmental factors that may influence protein production, and strategies for producing natural adhesives similar to the native mussel adhesive proteins. The production-scale availability of recombinant mussel adhesive proteins will enable researchers to formulate adhesives that are water-impervious and ecologically safe and can bind materials ranging from glass, plastics, metals, and wood to materials, such as bone or teeth, biological organisms, and other chemicals or molecules. Unfortunately, as of yet scientists have been unable to duplicate the processes that marine mussels use to create adhesive structures. This study provides a background on adhesive proteins identified in the blue mussel, Mytilus edulis, and introduces our research interests and discusses the future for continued research related to mussel adhesion. PMID:17990038

  10. A Review of Cell Adhesion Studies for Biomedical and Biological Applications

    Ahmad Khalili, Amelia; Ahmad, Mohd Ridzuan

    2015-01-01

    Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events. PMID:26251901

  11. A hydrophobic perfluoropolyether elastomer as a patternable biomaterial for cell culture and tissue engineering.

    Schulte, Vera A; Hu, Yibing; Diez, Mar; Bünger, Daniel; Möller, Martin; Lensen, Marga C

    2010-11-01

    We present a systematic study of a perfluoropolyether (PFPE)-based elastomer as a new biomaterial. Besides its excellent long-term stability and inertness, PFPE can be decorated with topographical surface structures by replica molding. Micrometer-sized pillar structures led to considerably different cell morphology of fibroblasts. Although PFPE is a very hydrophobic material we could show that PFPE substrates allow cell adhesion and spreading of primary human fibroblasts (HDF) very similar to that observed on standard cell culture substrates. Less advanced cell spreading was observed for L929 (murine fibroblast cell line) cells during the first 5 h in culture which was accompanied by retarded recruitment of α(v)β(3)-integrin into focal adhesions (FAs). After 24 h distinct FAs were evident also in L929 cells on PFPE. Furthermore, organization of soluble FN into a fibrillar ECM network was shown for hdF and L929 cells. Based on these results PFPE is believed to be a suitable substrate for several biological applications. On the one hand it is an ideal cell culture substrate for fundamental research of substrate-independent adhesion signaling due to its different characteristics (e.g. wettability, elasticity) compared to glass or TCPS. On the other hand it could be a promising implant material, especially due to its straightforward patternability, which is a tool to direct cell growth and differentiation. PMID:20708794

  12. Advanced biomaterials development from "natural products".

    Baier, R E

    1988-04-01

    Natural substances and structures can serve increasingly well as biomedical products, given recent advances in understanding of requirements for biocompatibility and of methods for their preservation and surface tailoring. A successful example is the derivation of limb salvaging vessels, used in arterial reconstructive surgery, from human umbilical cords. There are numerous opportunities for additional product development from the umbilical cords' main ingredient, Wharton's gel, ranging from biolubricants to wound-healing aids. Major problems yet to be overcome with natural starting materials are their propensity for calcification and eventual biodeterioration. Surface modification of biomaterials to exhibit desired degrees of interaction with contacting viable tissues promises the greatest beneficial results. General principles of bioadhesion have broad applicability, predicting material behavior in environments as diverse as blood, saliva, and seawater. PMID:3058928

  13. Chitosan dan Aplikasi Klinisnya Sebagai Biomaterial

    Bambang Irawan

    2015-10-01

    Full Text Available The development of new materials with both organic and inorganic structures is of great interest to obtain special material properties. Chitosan [2-amino-2-deoxy-D-glucan] can be obtained by N-deacetylation of chitin. Chitin is the second most abundant biopolymer in nature and the supporting material of crustaceans, insects, fungi etc. Chitosan is unique polysaccharide and has been widely used in various biomedical application due to its biocompatibility, low toxicity, biodegradability, non-immunogenic and non-carcinogenic character. In the past few years, chitosan and some of its modifications have been reported for use in biomedical applications such as artificial skin, wound dressing, anticoagulant, suture, drug delivery, vaccine carrier and dietary fibers. Recently, the use of chitosan and its derivatives has received much attention as temporary scaffolding to promotie mineralization or stimulate endochodral ossification. This article aims to give a broad overview of chitosan and its clinical applications as biomaterial.

  14. Laser surface modification of metallic biomaterials

    Bandyopadhyay, Amit; Balla, Vamsi Krishna; Roy, Mangal; Bose, Susmita

    2011-06-01

    Load-bearing metal implants often fail prematurely due to inadequate biocompatibility, mechanical/tribological properties, and poor osseointegration. It is well known that biomaterials' surface plays a vital role in the response to these metal implants in the biological environment. The biological effectiveness of artificial implants is determined mainly by their surface characteristics such as surface morphology, microstructure, composition, mechanical properties, wettabilility, and surface free energy. Hence, there is significant interest toward surface modification and effective design of load-bearing metal implants so as to improve their surface properties and thereby elicit a specific, desired, and timely response from the surrounding cells and tissues. In this article, we provide an insight into laser surface modification of Ti/Ti6Al4V alloy with or without functional gradation in composition and their microstructural, in vitro wear and biological properties for various loadbearing orthopedic applications.

  15. What future for zirconia as a biomaterial?

    Chevalier, Jérôme

    2006-02-01

    The failure events of Prozyr femoral heads in 2001-2002 have opened a strong, controversial issue on the future of zirconia as a biomaterial. The aim of this paper is to review and analyze the current knowledge on ageing process and on its effect on the long term performance of implants in order to distinguish between scientific facts and speculation. Current state of the art shows the strong variability of zirconia to in vivo degradation, as a consequence of the strong influence of processing on ageing process. As different zirconia from different vendors have different process related microstructure, there is a need to assess their ageing sensitivity with advanced and accurate techniques, and ISO standards should be modified, especially to gain confidence from clinicians. There is a trend today to develop alumina-zirconia composites as an alternative to monolithic alumina and zirconia: the issue of ageing is also discussed for these composites. PMID:16143387

  16. Patterned macroarray plates in comparison of bacterial adhesion inhibition of tantalum, titanium, and chromium compared with diamond-like carbon.

    Levon, Jaakko; Myllymaa, Katja; Kouri, Vesa-Petteri; Rautemaa, Riina; Kinnari, Teemu; Myllymaa, Sami; Konttinen, Yrjö T; Lappalainen, Reijo

    2010-03-15

    Staphylococcus aureus device-related infection is a common complication in implantology. Bacterial adhesion on implant surfaces is the initial step in the infective process. The aim was to develop a method suitable for quantitative bacterial adherence studies and to test a new diamond-like carbon (DLC) coating against commonly used metallic biomaterials with regards to Staphylococcus aureus adhesion. Patterned silicon chips with spots of tantalum, titanium, chromium, and DLC were produced using ultraviolet lithography and physical vapor deposition. These patterned chips were used as such or glued to array plates, pretreated with serum and exposed to S. aureus (S-15981) for 90 min, followed by acridine orange staining and fluorescence microscopy. An adhesion index showed that the ranking order of the biomaterials was titanium, tantalum, chromium, and DLC, with the DLC being clearly most resistant against colonization with S. aureus. Micropatterned surfaces are useful for quantitative comparison of bacterial adherence on different biomaterials. In the presence of serum, DLC is superior in its ability to resist adhesion and colonization by S. aureus compared with the commonly used biomaterial metals tantalum, titanium, and chromium. PMID:19437436

  17. PH dependent adhesive peptides

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  18. Review for carrageenan-based pharmaceutical biomaterials: favourable physical features versus adverse biological effects.

    Liu, Jingjing; Zhan, Xiudan; Wan, Jianbo; Wang, Yitao; Wang, Chunming

    2015-05-01

    Carrageenan (CRG) is a family of natural polysaccharides derived from seaweeds and has widely been used as food additives. In the past decade, owing to its attractive physicochemical properties, CRG has been developed into versatile biomaterials vehicles for drug delivery. Nevertheless, studies also emerged to reveal its adverse effects on the biological system. In this review, we critically appraise the latest literature (two thirds since 2008) on the development of CRG-based pharmaceutical vehicles and the perspective of using CRG for broader biomedical applications. We focus on how current strategies exploit the unique gelling mechanisms, strong water absorption and abundant functional groups of the three major CRG varieties. Notably, CRG-based matrices are demonstrated to increase drug loading and drug solubility, enabling release of orally administrated drugs in zero-order or in a significantly prolonged period. Other amazing features, such as pH-sensitivity and adhesive property, of CRG-based formulations are also introduced. Finally, we discuss the adverse influence of CRG on the human body and then suggest some future directions for the development of CRG-based biomaterials for broader applications in biomedicine. PMID:25659668

  19. Quantification of Staphylococcus aureus adhesion forces on various dental restorative materials using atomic force microscopy

    Merghni, Abderrahmen; Kammoun, Dorra; Hentati, Hajer; Janel, Sébastien; Popoff, Michka; Lafont, Frank; Aouni, Mahjoub; Mastouri, Maha

    2016-08-01

    In the oral cavity dental restorative biomaterials can act as a reservoir for infection with opportunistic Staphylococcus aureus pathogen, which can lead to the occurrence of secondary caries and treatment failures. Our aim was to evaluate the adhesion forces by S. aureus on four dental restorative biomaterials and to correlate this finding to differences in specific surface characteristics. Additionally, the influence of salivary conditioning films in exerted adhesion forces was investigated. The substrate hydrophobicity was measured by goniometer and the surface free energy was calculated using the equilibrium advancing contact angle values of water, formamide, and diiodomethane on the tested surfaces. The surface roughness was determined using atomic force microscope (AFM). Additionally, cell force spectroscopy was achieved to quantify the forces that drive cell-substrate interactions. S. aureus bacterium exerted a considerable adhesion forces on various dental restorative materials, which decreased in the presence of saliva conditioning film. The influence of the surface roughness and free energy in initial adhesion appears to be more important than the effect of hydrophobicity, either in presence or absence of saliva coating. Hence, control of surface properties of dental restorative biomaterials is of crucial importance in preventing the attachment and subsequent the biofilm formation.

  20. Particle adhesion and removal

    Mittal, K L

    2015-01-01

    The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal.  The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments.  Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand  particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and  n

  1. Combinational Effect of Cell Adhesion Biomolecules and Their Immobilized Polymer Property to Enhance Cell-Selective Adhesion

    Rio Kurimoto

    2016-01-01

    Full Text Available Although surface immobilization of medical devices with bioactive molecules is one of the most widely used strategies to improve biocompatibility, the physicochemical properties of the biomaterials significantly impact the activity of the immobilized molecules. Herein we investigate the combinational effects of cell-selective biomolecules and the hydrophobicity/hydrophilicity of the polymeric substrate on selective adhesion of endothelial cells (ECs, fibroblasts (FBs, and smooth muscle cells (SMCs. To control the polymeric substrate, biomolecules are immobilized on thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide (poly(NIPAAm-co-CIPAAm-grafted glass surfaces. By switching the molecular conformation of the biomolecule-immobilized polymers, the cell-selective adhesion performances are evaluated. In case of RGDS (Arg-Gly-Asp-Ser peptide-immobilized surfaces, all cell types adhere well regardless of the surface hydrophobicity. On the other hand, a tri-Arg-immobilized surface exhibits FB-selectivity when the surface is hydrophilic. Additionally, a tri-Ile-immobilized surface exhibits EC-selective cell adhesion when the surface is hydrophobic. We believe that the proposed concept, which is used to investigate the biomolecule-immobilized surface combination, is important to produce new biomaterials, which are highly demanded for medical implants and tissue engineering.

  2. XPS - an essential tool in biomaterial research

    Full text: Increased life expectancy has markedly enhanced the need for biomedical devices to combat life-threatening conditions (e.g., pacemakers, artificial blood vessels) or improve the quality of life (e.g., intraocular lenses, artificial ligaments, contact lenses). While the biomedical device industry has delivered remarkable benefits, many existing and emerging needs and applications are not adequately met with existing synthetic materials. Depending on the application, a biomaterial needs to meet a number of requirements to be 'biocompatible', such as appropriate mechanical properties, transparency, resistance to enzymatic degradation, and appropriate biological responses by the host environment. Surface science and surface analysis plays a key role in understanding and optimizing the molecular interfacial interactions between synthetic materials surfaces and biological media which lead to biological responses to implants. Many biological molecules such as proteins and lipids have surfactant activity and respond to interfaces on contact. Thus, an important part of achieving 'biocompatibility' is to produce an appropriate surface chemical composition that avoids undesirable biological consequences triggered by biological molecules recognizing a 'foreign' material interface. XPS surface analysis has proved uniquely suitable for studying several aspects of biomaterials. In order to interpret biological responses in terms of surface chemistry, it is essential that the surface be well characterized. However, for polymers this can be quite a challenge due to the inherent mobility of polymer chains. For instance, polyurethanes present a surface chemistry that differs from the 'bulk' chemistry. It is often desirable to utilize a bulk material with desirable bulk properties and improve its biocompatibility by the application of a surface modification or a thin coating. XPS has been used to verify the intended coating chemistry and the uniformity of thin coatings. On

  3. Engineering Immunomodulatory Biomaterials To Tune the Inflammatory Response.

    Vishwakarma, Ajaykumar; Bhise, Nupura S; Evangelista, Marta B; Rouwkema, Jeroen; Dokmeci, Mehmet R; Ghaemmaghami, Amir M; Vrana, Nihal Engin; Khademhosseini, Ali

    2016-06-01

    Current state-of-the-art biomedical implants and tissue engineering methods promise technologies to improve or even restore the function of diseased organs. However, one of the biggest challenges to clinical success is the lack of functional integration. A series of cellular and molecular events following biomaterial implantation poses an important bottleneck for developing breakthrough solutions. With inflammation increasingly recognized as a crucial component influencing regeneration, immunomodulation or immuno-engineering has emerged as a potential solution to overcome this key challenge in regenerative medicine. We postulate possibilities to utilize biomaterial physicochemical modifications to modulate the host inflammatory response and develop strategies for effective biomaterial integration. Biomaterial-based immunomodulation strategies can significantly ameliorate the outcomes of medical implants and tissue engineering therapies. PMID:27138899

  4. Brillouin microspectroscopy of nanostructured biomaterials: photonics assisted tailoring mechanical properties

    Meng, Zhaokai; Jaiswal, Manish K.; Chitrakar, Chandani; Thakur, Teena; Gaharwar, Akhilesh K.; Yakovlev, Vladislav V.

    2016-03-01

    Developing new biomaterials is essential for the next-generation of materials for bioenergy, bioelectronics, basic biology, medical diagnostics, cancer research, and regenerative medicine. Specifically, recent progress in nanotechnology has stimulated the development of multifunctional biomaterials for tissue engineering applications. The physical properties of nanocomposite biomaterials, including elasticity and viscosity, play key roles in controlling cell fate, which underlines therapeutic success. Conventional mechanical tests, including uniaxial compression and tension, dynamic mechanical analysis and shear rheology, require mechanical forces to be directly exerted onto the sample and therefore may not be suitable for in situ measurements or continuous monitoring of mechanical stiffness. In this study, we employ spontaneous Brillouin spectroscopy as a viscoelasticity-specific probing technique. We utilized a Brillouin spectrometer to characterize biomaterial's microscopic elasticity and correlated those with conventional mechanical tests (e.g., rheology).

  5. Design of polymer-biopolymer-hydroxyapatite biomaterials for bone tissue engineering: Through molecular control of interfaces

    Verma, Devendra

    -containing scaffolds. Hydroxyapatite-containing chitosan/PgA scaffolds maintained their structural integrity under wet conditions. These scaffolds showed extremely porous (97.4%) and interconnected architecture. These scaffolds also promoted cell adhesion, proliferation and differentiation, Osteoblast cells formed nodular structure on thin films and scaffold. Mineralization of these nodules was confirmed by alizarin red S staining. Even after 20 days of seeding, all the cells were found alive. Our results indicated that chitosan-PgA-hydroxyapatite composite scaffolds have high potential for bone tissue engineering. This dissertation represents a comprehensive study on design of novel bone biomaterials through tailoring of interfaces in nanocomposites of polymers, biopolymer and hydroxyapatite.

  6. Characterization of Biomaterials by Soft X-Ray Spectromicroscopy

    Hitchcock, Adam P.; Leung, Bonnie O.; Brash, John L.

    2010-01-01

    Synchrotron-based soft X-ray spectromicroscopy techniques are emerging as useful tools to characterize potentially biocompatible materials and to probe protein interactions with model biomaterial surfaces. Simultaneous quantitative chemical analysis of the near surface region of the candidate biomaterial, and adsorbed proteins, peptides or other biological species can be obtained at high spatial resolution via scanning transmission X-ray microscopy (STXM) and X-ray photoemission electron micr...

  7. Numerical Simulation of thePorous Structure of Biomaterials

    WANGHui-min; YANYu-hua; LIShi-pu

    2004-01-01

    Porous biomaterials are widely used as bone replacement materials because of thers high biocompatibility and osteoconductivity property. Understanding of their porous structure (i. e. geometrical and topological characteristic) and studying how to the body fluid flow through them are essential to investigate thed egradation behaviour at the surface-liquid interface. This research develops a numerical model to simulate the porous structure of biomaterials based on the stochastic approach in pore size distribution and interconnectivity.

  8. A Multidisciplined Teaching Reform of Biomaterials Course for Undergraduate Students

    Li, Xiaoming; Zhao, Feng; Pu, Fang; Liu, Haifeng; Niu, Xufeng; Zhou, Gang; Li, Deyu; Fan, Yubo; Feng, Qingling; Cui, Fu-zhai; Watari, Fumio

    2015-12-01

    The biomaterials science has advanced in a high speed with global science and technology development during the recent decades, which experts predict to be more obvious in the near future with a more significant position for medicine and health care. Although the three traditional subjects, such as medical science, materials science and biology that act as a scaffold to support the structure of biomaterials science, are still essential for the research and education of biomaterials, other subjects, such as mechanical engineering, mechanics, computer science, automatic science, nanotechnology, and Bio-MEMS, are playing more and more important roles in the modern biomaterials science development. Thus, the research and education of modern biomaterials science should require a logical integration of the interdisciplinary science and technology, which not only concerns medical science, materials science and biology, but also includes other subjects that have been stated above. This article focuses on multidisciplinary nature of biomaterials, the awareness of which is currently lacking in the education at undergraduate stage. In order to meet this educational challenge, we presented a multidisciplinary course that referred to not only traditional sciences, but also frontier sciences and lasted for a whole academic year for senior biomaterials undergraduate students with principles of a better understanding of the modern biomaterials science and meeting the requirements of the future development in this area. The course has been shown to gain the recognition of the participants by questionaries and specific "before and after" comments and has also gained high recognition and persistent supports from our university. The idea of this course might be also fit for the education and construction of some other disciplines.

  9. Advancing the field of 3D biomaterial printing.

    Jakus, Adam E; Rutz, Alexandra L; Shah, Ramille N

    2016-02-01

    3D biomaterial printing has emerged as a potentially revolutionary technology, promising to transform both research and medical therapeutics. Although there has been recent progress in the field, on-demand fabrication of functional and transplantable tissues and organs is still a distant reality. To advance to this point, there are two major technical challenges that must be overcome. The first is expanding upon the limited variety of available 3D printable biomaterials (biomaterial inks), which currently do not adequately represent the physical, chemical, and biological complexity and diversity of tissues and organs within the human body. Newly developed biomaterial inks and the resulting 3D printed constructs must meet numerous interdependent requirements, including those that lead to optimal printing, structural, and biological outcomes. The second challenge is developing and implementing comprehensive biomaterial ink and printed structure characterization combined with in vitro and in vivo tissue- and organ-specific evaluation. This perspective outlines considerations for addressing these technical hurdles that, once overcome, will facilitate rapid advancement of 3D biomaterial printing as an indispensable tool for both investigating complex tissue and organ morphogenesis and for developing functional devices for a variety of diagnostic and regenerative medicine applications. PMID:26752507

  10. Biomaterial Applications in Cell-Based Therapy in Experimental Stroke

    Boisserand, Ligia S. B.; Kodama, Tomonobu; Papassin, Jérémie; Auzely, Rachel; Moisan, Anaïck; Rome, Claire; Detante, Olivier

    2016-01-01

    Stroke is an important health issue corresponding to the second cause of mortality and first cause of severe disability with no effective treatments after the first hours of onset. Regenerative approaches such as cell therapy provide an increase in endogenous brain structural plasticity but they are not enough to promote a complete recovery. Tissue engineering has recently aroused a major interesting development of biomaterials for use into the central nervous system. Many biomaterials have been engineered based on natural compounds, synthetic compounds, or a mix of both with the aim of providing polymers with specific properties. The mechanical properties of biomaterials can be exquisitely regulated forming polymers with different stiffness, modifiable physical state that polymerizes in situ, or small particles encapsulating cells or growth factors. The choice of biomaterial compounds should be adapted for the different applications, structure target, and delay of administration. Biocompatibilities with embedded cells and with the host tissue and biodegradation rate must be considerate. In this paper, we review the different applications of biomaterials combined with cell therapy in ischemic stroke and we explore specific features such as choice of biomaterial compounds and physical and mechanical properties concerning the recent studies in experimental stroke.

  11. Atomic layer deposition of nanoporous biomaterials.

    Narayan, R. J.; Adiga, S. P.; Pellin, M. J.; Curtiss, L. A.; Stafslien, S.; Chisholm, B.; Monteiro-Riviere, N. A.; Brigmon, R. L.; Elam, J. W.; Univ. of North Carolina; North Carolina State Univ.; Eastman Kodak Co.; North Dakota State Univ.; SRL

    2010-03-01

    Due to its chemical stability, uniform pore size, and high pore density, nanoporous alumina is being investigated for use in biosensing, drug delivery, hemodialysis, and other medical applications. In recent work, we have examined the use of atomic layer deposition for coating the surfaces of nanoporous alumina membranes. Zinc oxide coatings were deposited on nanoporous alumina membranes using atomic layer deposition. The zinc oxide-coated nanoporous alumina membranes demonstrated antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. These results suggest that atomic layer deposition is an attractive technique for modifying the surfaces of nanoporous alumina membranes and other nanostructured biomaterials. Nanoporous alumina, also known as anodic aluminum oxide (AAO), is a nanomaterial that exhibits several unusual properties, including high pore densities, straight pores, small pore sizes, and uniform pore sizes. In 1953, Keller et al. showed that anodizing aluminum in acid electrolytes results in a thick layer of nearly cylindrical pores, which are arranged in a close-packed hexagonal cell structure. More recently, Matsuda & Fukuda demonstrated preparation of highly ordered platinum and gold nanohole arrays using a replication process. In this study, a negative structure of nanoporous alumina was initially fabricated and a positive structure of a nanoporous metal was subsequently fabricated. Over the past fifteen years, nanoporous alumina membranes have been used as templates for growth of a variety of nanostructured materials, including nanotubes, nanowires, nanorods, and nanoporous membranes.

  12. Biomaterials for mRNA Delivery

    Islam, Mohammad Ariful; Reesor, Emma K. G.; Xu, Yingjie; Zope, Harshal R.; Zetter, Bruce R.; Shi, Jinjun

    2015-01-01

    Messenger RNA (mRNA) has recently emerged with remarkable potential as an effective alternative to DNA-based therapies because of several unique advantages. mRNA does not require nuclear entry for transfection activity and has a negligible chance of integrating into the host genome which excludes the possibility of potentially detrimental genomic alternations. Chemical modification of mRNA has further enhanced its stability and decreased its activation of innate immune responses. Additionally, mRNA has been found to have rapid expression and predictable kinetics. Nevertheless, the ubiquitous application of mRNA remains challenging given its unfavorable attributes, such as large size, negative charge and susceptibility to enzymatic degradation. Further refinement of mRNA delivery modalities is therefore essential for its development as a therapeutic tool. This review provides an exclusive overview of current state-of-the-art biomaterials and nanotechnology platforms for mRNA delivery, and discusses future prospects to bring these exciting technologies into clinical practice. PMID:26280625

  13. Useful surface parameters for biomaterial discrimination.

    Etxeberria, Marina; Escuin, Tomas; Vinas, Miquel; Ascaso, Carlos

    2015-01-01

    Topographical features of biomaterials' surfaces are determinant when addressing their application site. Unfortunately up to date there has not been an agreement regarding which surface parameters are more representative in discriminating between materials. Discs (n = 16) of different currently used materials for implant prostheses fabrication, such as cast cobalt-chrome, direct laser metal soldered (DLMS) cobalt-chrome, titanium grade V, zirconia (Y-TZP), E-glass fiber-reinforced composite and polyetheretherketone (PEEK) were manufactured. Nanoscale topographical surface roughness parameters generated by atomic force microscopy (AFM), microscale surface roughness parameters obtained by white light interferometry (WLI) and water angle values obtained by the sessile-water-drop method were analyzed in order to assess which parameter provides the best optimum surface characterization method. Correlations between nanoroughness, microroughness, and hydrophobicity data were performed to achieve the best parameters giving the highest discriminatory power. A subset of six parameters for surface characterization were proposed. AFM and WLI techniques gave complementary information. Wettability did not correlate with any of the nanoroughness parameters while it however showed a weak correlation with microroughness parameters. PMID:26148576

  14. Radiation-curable adhesives

    Radiation-curable adhesives may be classified into two broad categories. In the first category, adhesive bonding occurs as a direct result of irradiation. The second category includes pressure-sensitive and hot-melt adhesives, which are composed of linear or lightly cross-linked polymers prepared by a radiation-induced polymerization reaction. This chapter is mainly concerned with radiation-curable adhesives of the first category. The various adhesive types are discussed and adhesive performance is examined, particularly in relation to the chemistry and chemical technology which underlies the individual materials. A description of a limited number of representative applications is included as is an outline of recent developments of curing and dispensing equipment. 268 refs., 14 figs., 13 tabs

  15. Inhibition of postsurgical adhesions by methylene blue-loaded nanofibers versus cast film matrices.

    El-Sayed, Nesma; Galal, Sally; El-Gowelli, Hanan; El-Khordagui, Labiba

    2016-07-01

    In the quest for barrier membranes for the prevention of post-surgical tissue adhesions, polymer matrices may provide a platform of biomaterials with versatile properties. However, the relationship between the anti-adhesion effects of different polymer matrices and their physicochemical and structural properties is not yet adequately understood. In a preclinical study using a rat cecum model, we directly compared the anti-adhesion potential of polyhydroxybutyrate (PHB) electrospun nanofibrous versus cast film matrices loaded with methylene blue (MB) as antioxidant adhesion inhibitor. PHB retained MB presumably forming MB-bioactivated matrices. In the preclinical study, quantitative morphologic assessment in addition to histopathologic and SEM examinations 14 days post-surgery indicated that plain PHB NFs and MB-PHB NFs, moderately enhanced cecal wall healing and inhibited adhesion formation. In contrast, reshaping PHB as cast films, significantly enhanced healing, reduced adhesion bands and prevented inter-visceral adhesions. Cast films also inhibited tissue attachment to the matrix recovered 14 days post-surgery. Both PHB matrix types reduced tissue inflammation. Despite tissue anti-adhesion potential of individual matrix components, modulation of the micro-architectural properties generated polymer barriers with varying tissue anti-adhesion and healing potentials, the MB-loaded cast film achieving the best outcome. PMID:27093975

  16. Prevention of bacterial adhesion

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will...

  17. Preparing polymeric biomaterials using "click" chemistry techniques

    Lin, Fei

    Significant efforts have been focused on preparing degradable polymeric biomaterials with controllable properties, which have the potential to stimulate specific cellular responses at the molecular level. Click reactions provide a universal tool box to achieve that goal through molecular level design and modification. This dissertation demonstrates multiple methodologies and techniques to develop advanced biomaterials through combining degradable polymers and click chemistry. In my initial work, a novel class of amino acid-based poly(ester urea)s (PEU) materials was designed and prepared for potential applications in bone defect treatment. PEUs were synthesized via interfacial polycondensation, and showed degradability in vivo and possessed mechanical strength superior to conventionally used polyesters. Further mechanical enhancement was achieved after covalent crosslinking with a short peptide crosslinker derived from osteogenic growth peptide (OGP). The in vitro and in an in vivo subcutaneous rat model demonstrated that the OGP-based crosslinkers promoted proliferative activity of cells and accelerated degradation properties of PEUs. As a continuous study, extra efforts were focused on the development of PEUs with functional pendant groups, including alkyne, azide, alkene, tyrosine phenol, and ketone groups. PEUs with Mw exceeding to 100K Da were obtained via interfacial polycondensation, and the concentration of pendent groups was varied using a copolymerization strategy. Electrospinning was used to fabricate PEU nanofiber matrices with mechanical strengths suitable for tissue engineering. A series of biomolecules were conjugated to nanofiber surface following electrospinning using click reactions in aqueous media. The ability to derivatize PEUs with biological motifs using high efficient chemical reactions will significantly expand their use in vitro and in vivo. Based on similar principles, a series of mono- and multifunctionalized polycaprolactone (PCL

  18. Proteins at the Biomaterial Electrolyte Interface

    Tengvall, Pentti

    2005-03-01

    Proteins adsorb rapidly onto solid and polymeric surfaces because the association process is in the vast majority of cases energetically favourable, i.e. exothermic. The most common exceptions to this rule are hydrophilic interfaces with low net charge and high mobility, e.g. immobilized PEGs. Current research in the research area tries to understand and control unwanted and wanted adsorption by studying the adsorption kinetics, protein surface binding specificity, protein exchange at interfaces, and surface protein repulsion mechanisms. In blood plasma model systems humoral cascade reactions such as surface mediated coagulation and immune complement raise considerable interest due to the immediate association to blood compatibility, and in tissue applications the binding between surfaces and membrane receptors in cells and tissues. Thus, the understanding of interfacial events at the protein level is of large importance in applications such as blood and tissue contacting biomaterials, in vitro medical and biological diagnostics, food industry and in marine anti-fouling technology. Well described consequences of adsorption are a lowered system energy, increased system entropy, irreversible binding, conformational changes, specific surface/protein interactions, and in biomedical materials applications surface opsonization followed by cell-surface interactions and a host tissue response. This lecture will deal with some mechanisms known to be of importance for the adsorption processes, such as the influence of surface chemistry and surface energy, the composition of the protein solution, the Vroman effect, and residence time. Examples will be shown from ellipsometric experiments using different model surfaces in single/few protein solutions, and specific attention be given to blood serum and plasma experiments on coagulation and immune complement at interfaces.

  19. 3'-Hydroxy-4-methoxychalcone as a potential antibacterial coating on polymeric biomaterials

    Antimicrobial property of chalcone coated high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP) and polyurethane (PU) against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is reported here. The presence of chalcone on the surface was confirmed from fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Bacterial adhesion decreased considerably on all the coated surfaces. Bacterial adhesion was highest on PU surface (most hydrophobic) and lowest on HDPE (most hydrophilic) surface. Chalcone seems to damage the membrane of the bacteria as well as exhibit slimicidal activity. Reasonably good correlation was observed between the CFU (Colony Forming Units) ratio (it is defined as the ratio of CFU on coated surface to the chalcone uncoated surface) at the 24th hour against both hydrophobicity of the microorganism and roughness of the coated polymeric surfaces. Increasing roughness of the polymer and hydrophobicity of the microorganisms were positively and negatively correlated respectively with CFU ratio. Hence, the chalcone coated polymers can be used in the development of newer biomaterials.

  20. Antibacterial Efficacy of Iron-Oxide Nanoparticles against Biofilms on Different Biomaterial Surfaces

    Monica Thukkaram

    2014-01-01

    Full Text Available Biofilm growth on the implant surface is the number one cause of the failure of the implants. Biofilms on implant surfaces are hard to eliminate by antibiotics due to the protection offered by the exopolymeric substances that embed the organisms in a matrix, impenetrable for most antibiotics and immune cells. Application of metals in nanoscale is considered to resolve biofilm formation. Here we studied the effect of iron-oxide nanoparticles over biofilm formation on different biomaterial surfaces and pluronic coated surfaces. Bacterial adhesion for 30 min showed significant reduction in bacterial adhesion on pluronic coated surfaces compared to other surfaces. Subsequently, bacteria were allowed to grow for 24 h in the presence of different concentrations of iron-oxide nanoparticles. A significant reduction in biofilm growth was observed in the presence of the highest concentration of iron-oxide nanoparticles on pluronic coated surfaces compared to other surfaces. Therefore, combination of polymer brush coating and iron-oxide nanoparticles could show a significant reduction in biofilm formation.

  1. 3'-Hydroxy-4-methoxychalcone as a potential antibacterial coating on polymeric biomaterials

    Sivakumar, P.M., E-mail: sivamedchem@gmail.com [Department of Biotechnology, Indian Institute of Technology Madras, Adyar, Chennai 600036 (India); Iyer, Geetha, E-mail: geethu.v.iyer@gmail.com [Department of Biotechnology, Indian Institute of Technology Madras, Adyar, Chennai 600036 (India); Natesan, Lavanya [Department of Biotechnology, Indian Institute of Technology Madras, Adyar, Chennai 600036 (India); Doble, Mukesh, E-mail: mukeshd@iitm.ac.in [Department of Biotechnology, Indian Institute of Technology Madras, Adyar, Chennai 600036 (India)

    2010-08-01

    Antimicrobial property of chalcone coated high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP) and polyurethane (PU) against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is reported here. The presence of chalcone on the surface was confirmed from fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Bacterial adhesion decreased considerably on all the coated surfaces. Bacterial adhesion was highest on PU surface (most hydrophobic) and lowest on HDPE (most hydrophilic) surface. Chalcone seems to damage the membrane of the bacteria as well as exhibit slimicidal activity. Reasonably good correlation was observed between the CFU (Colony Forming Units) ratio (it is defined as the ratio of CFU on coated surface to the chalcone uncoated surface) at the 24th hour against both hydrophobicity of the microorganism and roughness of the coated polymeric surfaces. Increasing roughness of the polymer and hydrophobicity of the microorganisms were positively and negatively correlated respectively with CFU ratio. Hence, the chalcone coated polymers can be used in the development of newer biomaterials.

  2. 3‧-Hydroxy-4-methoxychalcone as a potential antibacterial coating on polymeric biomaterials

    Sivakumar, P. M.; Iyer, Geetha; Natesan, Lavanya; Doble, Mukesh

    2010-08-01

    Antimicrobial property of chalcone coated high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP) and polyurethane (PU) against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is reported here. The presence of chalcone on the surface was confirmed from fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Bacterial adhesion decreased considerably on all the coated surfaces. Bacterial adhesion was highest on PU surface (most hydrophobic) and lowest on HDPE (most hydrophilic) surface. Chalcone seems to damage the membrane of the bacteria as well as exhibit slimicidal activity. Reasonably good correlation was observed between the CFU (Colony Forming Units) ratio (it is defined as the ratio of CFU on coated surface to the chalcone uncoated surface) at the 24th hour against both hydrophobicity of the microorganism and roughness of the coated polymeric surfaces. Increasing roughness of the polymer and hydrophobicity of the microorganisms were positively and negatively correlated respectively with CFU ratio. Hence, the chalcone coated polymers can be used in the development of newer biomaterials.

  3. Nanofibers and nanoparticles from the insect-capturing adhesive of the Sundew (Drosera) for cell attachment

    Zhang Mingjun; Lenaghan Scott C; Xia Lijin; Dong Lixin; He Wei; Henson William R; Fan Xudong

    2010-01-01

    Abstract Background The search for naturally occurring nanocomposites with diverse properties for tissue engineering has been a major interest for biomaterial research. In this study, we investigated a nanofiber and nanoparticle based nanocomposite secreted from an insect-capturing plant, the Sundew, for cell attachment. The adhesive nanocomposite has demonstrated high biocompatibility and is ready to be used with minimal preparation. Results Atomic force microscopy (AFM) conducted on the adh...

  4. Substrate effect modulates adhesion and proliferation of fibroblast on graphene layer.

    Lin, Feng; Du, Feng; Huang, Jianyong; Chau, Alicia; Zhou, Yongsheng; Duan, Huiling; Wang, Jianxiang; Xiong, Chunyang

    2016-10-01

    Graphene is an emerging candidate for biomedical applications, including biosensor, drug delivery and scaffold biomaterials. Cellular functions and behaviors on different graphene-coated substrates, however, still remain elusive to a great extent. This paper explored the functional responses of cells such as adhesion and proliferation, to different kinds of substrates including coverslips, silicone, polydimethylsiloxane (PDMS) with different curing ratios, PDMS treated with oxygen plasma, and their counterparts coated with single layer graphene (SLG). Specifically, adherent cell number, spreading area and cytoskeleton configuration were exploited to characterize cell-substrate adhesion ability, while MTT assay was employed to test the proliferation capability of fibroblasts. Experimental outcome demonstrated graphene coating had excellent cytocompatibility, which could lead to an increase in early adhesion, spreading, proliferation, and remodeling of cytoskeletons of fibroblast cells. Notably, it was found that the underlying substrate effect, e.g., stiffness of substrate materials, could essentially regulate the adhesion and proliferation of cells cultured on graphene. The stiffer the substrates were, the stronger the abilities of adhesion and proliferation of fibroblasts were. This study not only deepens our understanding of substrate-modulated interfacial interactions between live cells and graphene, but also provides a valuable guidance for the design and application of graphene-based biomaterials in biomedical engineering. PMID:27451366

  5. Characterization of Biomaterials by Soft X-Ray Spectromicroscopy

    Adam P. Hitchcock

    2010-07-01

    Full Text Available Synchrotron-based soft X-ray spectromicroscopy techniques are emerging as useful tools to characterize potentially biocompatible materials and to probe protein interactions with model biomaterial surfaces. Simultaneous quantitative chemical analysis of the near surface region of the candidate biomaterial, and adsorbed proteins, peptides or other biological species can be obtained at high spatial resolution via scanning transmission X-ray microscopy (STXM and X-ray photoemission electron microscopy (X-PEEM. Both techniques use near-edge X-ray absorption fine structure (NEXAFS spectral contrast for chemical identification and quantitation. The capabilities of STXM and X-PEEM for the analysis of biomaterials are reviewed and illustrated by three recent studies: (1 characterization of hydrophobic surfaces, including adsorption of fibrinogen (Fg or human serum albumin (HSA to hydrophobic polymeric thin films, (2 studies of HSA adsorption to biodegradable or potentially biocompatible polymers, and (3 studies of biomaterials under fully hydrated conditions. Other recent applications of STXM and X-PEEM to biomaterials are also reviewed.

  6. Injectable biomaterials for minimally invasive orthopedic treatments.

    Jayabalan, M; Shalumon, K T; Mitha, M K

    2009-06-01

    Biodegradable and injectable hydroxy terminated-poly propylene fumarate (HT-PPF) bone cement was developed. The injectable formulation consisting HT-PPF and comonomer, n-vinyl pyrrolidone, calcium phosphate filler, free radical catalyst, accelerator and radiopaque agent sets rapidly to hard mass with low exothermic temperature. The candidate bone cement attains mechanical strength more than the required compressive strength of 5 MPa and compressive modulus 50 MPa. The candidate bone cement resin elicits cell adhesion and cytoplasmic spreading of osteoblast cells. The cured bone cement does not induce intracutaneous irritation and skin sensitization. The candidate bone cement is tissue compatible without eliciting any adverse tissue reactions. The candidate bone cement is osteoconductive and inductive and allow osteointegration and bone remodeling. HT-PPF bone cement is candidate bone cement for minimally invasive radiological procedures for the treatment of bone diseases and spinal compression fractures. PMID:19160023

  7. Tissue adhesives in otorhinolaryngology

    Schneider, Gerlind

    2009-01-01

    Full Text Available The development of medical tissue adhesives has a long history without finding an all-purpose tissue adhesive for clinical daily routine. This is caused by the specific demands which are made on a tissue adhesive, and the different areas of application. In otorhinolaryngology, on the one hand, this is the mucosal environment as well as the application on bones, cartilage and periphery nerves. On the other hand, there are stressed regions (skin, oral cavity, pharynx, oesophagus, trachea and unstressed regions (middle ear, nose and paranasal sinuses, cranial bones. But due to the facts that adhesives can have considerable advantages in assuring surgery results, prevention of complications and so reduction of medical costs/treatment expenses, the search for new adhesives for use in otorhinolaryngology will be continued intensively. In parallel, appropriate application systems have to be developed for microscopic and endoscopic use.

  8. Biomaterial systems for orthopedic tissue engineering

    Spoerke, Erik David

    2003-06-01

    The World Health Organization has estimated that one out of seven Americans suffers from a musculoskeletal impairment, annually incurring 28.6 million musculoskeletal injuries---more than half of all injuries. Bone tissue engineering has evolved rapidly to address this continued health concern. In the last decade, the focus of orthopedic biomaterials design has shifted from the use of common engineering metals and plastics to smart materials designed to mimic nature and elicit favorable bioresponse. Working within this new paradigm, this thesis explores unique chemical and materials systems for orthopedic tissue engineering. Improving on current titanium implant technologies, porous titanium scaffolds were utilized to better approximate the mechanical and structural properties of natural bone. These foam scaffolds were enhanced with bioactive coatings, designed to enhance osteoblastic implant colonization. The biopolymer poly(L-lysine) was incorporated into both hydroxypatite and octacalcium phosphate mineral phases to create modified organoapatite and pLys-CP coatings respectively. These coatings were synthesized and characterized on titanium surfaces, including porous structures such as titanium mesh and titanium foam. In addition, in vitro osteoblastic cell culture experiments probed the biological influences of these coatings. Organoapatite (OA) accelerated preosteoblastic colonization of titanium mesh and improved cellular ingrowth into titanium foam. Alternatively, the thin, uniform pLys-CP coating demonstrated significant potential as a substrate for chemically binding biological molecules and supramolecular assemblies. Biologically, pLys-CP demonstrated enhanced cellular attachment over titanium and inorganic calcium phosphate controls. Supramolecular self-assembled nanofiber assemblies were also explored both as stand-alone tissue engineering gels and as titanium coatings. Self-supporting nanofiber gels induced accelerated, biomimetic mineralization

  9. Biomaterial based cardiac tissue engineering and its applications.

    Huyer, Locke Davenport; Montgomery, Miles; Zhao, Yimu; Xiao, Yun; Conant, Genevieve; Korolj, Anastasia; Radisic, Milica

    2015-06-01

    Cardiovascular disease is a leading cause of death worldwide, necessitating the development of effective treatment strategies. A myocardial infarction involves the blockage of a coronary artery leading to depletion of nutrient and oxygen supply to cardiomyocytes and massive cell death in a region of the myocardium. Cardiac tissue engineering is the growth of functional cardiac tissue in vitro on biomaterial scaffolds for regenerative medicine application. This strategy relies on the optimization of the complex relationship between cell networks and biomaterial properties. In this review, we discuss important biomaterial properties for cardiac tissue engineering applications, such as elasticity, degradation, and induced host response, and their relationship to engineered cardiac cell environments. With these properties in mind, we also emphasize in vitro use of cardiac tissues for high-throughput drug screening and disease modelling. PMID:25989939

  10. Biomaterials mediated microRNA delivery for bone tissue engineering.

    Sriram, M; Sainitya, R; Kalyanaraman, V; Dhivya, S; Selvamurugan, N

    2015-03-01

    Bone tissue engineering is an alternative strategy to overcome the problems associated with traditional treatments for bone defects. A number of bioactive materials along with new techniques like porous scaffold implantation, gene delivery, 3D organ printing are now-a-days emerging for traditional bone grafts and metal implants. Studying the molecular mechanisms through which these biomaterials induce osteogenesis is an equally hot field. Biomaterials could determine the fate of a cell via microRNAs (miRNAs). miRNAs are short non-coding RNAs that act as post-transcriptional regulators of gene expression and play an essential role for regulation of cell specific lineages including osteogenesis. Thus, this review focuses the recent trends on establishing a link of biomaterials with miRNAs and their delivery for bone tissue engineering applications. PMID:25543062

  11. Solvent-free functionalization of silicone rubber and efficacy of PAAm brushes grafted from an amino-PPX layer against bacterial adhesion

    Fundeanu, Irina; Klee, Doris; Schouten, Arend J.; Busscher, Henk J.; van der Mei, Henny C.

    2010-01-01

    Silicone rubber is a frequently employed biomaterial that is prone to bacterial adhesion and biofilm formation. In this study, the surface of silicone rubber was solvent-free functionalized by chemical vapor deposition (CVD) of poly(o-amino-p-xylylene-co-p-xylylene (amino-PPX). Subsequently, the ami

  12. Nanofibers and nanoparticles from the insect-capturing adhesive of the Sundew (Drosera for cell attachment

    Zhang Mingjun

    2010-08-01

    Full Text Available Abstract Background The search for naturally occurring nanocomposites with diverse properties for tissue engineering has been a major interest for biomaterial research. In this study, we investigated a nanofiber and nanoparticle based nanocomposite secreted from an insect-capturing plant, the Sundew, for cell attachment. The adhesive nanocomposite has demonstrated high biocompatibility and is ready to be used with minimal preparation. Results Atomic force microscopy (AFM conducted on the adhesive from three species of Sundew found that a network of nanofibers and nanoparticles with various sizes existed independent of the coated surface. AFM and light microscopy confirmed that the pattern of nanofibers corresponded to Alcian Blue staining for polysaccharide. Transmission electron microscopy identified a low abundance of nanoparticles in different pattern form AFM observations. In addition, energy-dispersive X-ray spectroscopy revealed the presence of Ca, Mg, and Cl, common components of biological salts. Study of the material properties of the adhesive yielded high viscoelasticity from the liquid adhesive, with reduced elasticity observed in the dried adhesive. The ability of PC12 neuron-like cells to attach and grow on the network of nanofibers created from the dried adhesive demonstrated the potential of this network to be used in tissue engineering, and other biomedical applications. Conclusions This discovery demonstrates how a naturally occurring nanofiber and nanoparticle based nanocomposite from the adhesive of Sundew can be used for tissue engineering, and opens the possibility for further examination of natural plant adhesives for biomedical applications.

  13. Designed biomaterials to mimic the mechanical properties of muscles.

    Lv, Shanshan; Dudek, Daniel M; Cao, Yi; Balamurali, M M; Gosline, John; Li, Hongbin

    2010-05-01

    The passive elasticity of muscle is largely governed by the I-band part of the giant muscle protein titin, a complex molecular spring composed of a series of individually folded immunoglobulin-like domains as well as largely unstructured unique sequences. These mechanical elements have distinct mechanical properties, and when combined, they provide the desired passive elastic properties of muscle, which are a unique combination of strength, extensibility and resilience. Single-molecule atomic force microscopy (AFM) studies demonstrated that the macroscopic behaviour of titin in intact myofibrils can be reconstituted by combining the mechanical properties of these mechanical elements measured at the single-molecule level. Here we report artificial elastomeric proteins that mimic the molecular architecture of titin through the combination of well-characterized protein domains GB1 and resilin. We show that these artificial elastomeric proteins can be photochemically crosslinked and cast into solid biomaterials. These biomaterials behave as rubber-like materials showing high resilience at low strain and as shock-absorber-like materials at high strain by effectively dissipating energy. These properties are comparable to the passive elastic properties of muscles within the physiological range of sarcomere length and so these materials represent a new muscle-mimetic biomaterial. The mechanical properties of these biomaterials can be fine-tuned by adjusting the composition of the elastomeric proteins, providing the opportunity to develop biomaterials that are mimetic of different types of muscles. We anticipate that these biomaterials will find applications in tissue engineering as scaffold and matrix for artificial muscles. PMID:20445626

  14. Biosorption of heavy metals from aqueous solutions using keratin biomaterials

    Zhang, Helan

    2014-01-01

    La biosorció és una tècnica eficaç per a l'eliminació de metalls pesants de les aigües residuals resultants de l'activitat humana, principalment de les activitats industrials actuals. Els biomaterials provinents de residus es consideren alternatives ideals com a nous biosorbentes donada la baixa relació del seu cost amb la seva eficàcia i alta capacitat d'adsorció per a metalls pesants. Una àmplia gamma de biomaterials de baix cost provinents de residus, alguns dels quals provenen de process...

  15. Development of Nano-biomaterials for Bone Repair

    2005-01-01

    A new kind of nano-biomaterials of nano apatite ( NA ) and polyamide8063 ( PA ) composite was prepared by direct using NA slurry. The experimental results showed that the NA content in the composite was similar to that of natural bone. Interface chemical bonding was formed between NA and PA. The NA keeps the original morphological structure with a crystal size of 10- 30 nm in width by 50- 90 nm in length with a ratio of~ 2.5 and distributed uniformly in the polymer. The synthetic nano-biomaterials could be one of the best bioactive materials for load-bearing bone repair or substitution materials.

  16. BIOMATERIAL IMPLANTS IN BONE FRACTURES PRODUCED IN RATS FIBULAS

    Shirane, Henrique Yassuhiro; Oda, Diogo Yochizumi; Pinheiro, Thiago Cerizza; Cunha, Marcelo Rodrigues da

    2015-01-01

    To evaluate the importance of collagen and hydroxyapatite in the regeneration of fractures experimentally induced in the fibulas of rats. Method: 15 rats were used. These were subjected to surgery to remove a fragment from the fibula. This site then received a graft consisting of a silicone tubes filled with hydroxyapatite and collagen. Results: Little bone neoformation occurred inside the tubes filled with the biomaterials. There was more neoformation in the tubes with collagen. Conclusion: The biomaterials used demonstrated biocompatibility and osteoconductive capacity that was capable of stimulating osteogenesis, even in bones with secondary mechanical and morphological functions such as the fibula of rats. PMID:27047813

  17. Teeth and bones: applications of surface science to dental materials and related biomaterials

    Jones, F. H.

    2001-05-01

    Recent years have seen a considerable upsurge in publications concerning the surface structure and chemistry of materials with biological or biomedical applications. Within the body, gas-solid interactions become relatively less significant and solid-liquid or solid-solid interfaces dominate, providing new challenges for the surface scientist. The current paper aims to provide a timely review of the use of surface analysis and modification techniques within the biomaterials field. A broad overview of applications in a number of related areas is given with particular attention focusing on those materials commonly encountered in dentistry and oral or maxillofacial implantology. Several specific issues of current interest are discussed. The interaction between synthetic and natural solids, both in the oral environment and elsewhere in the body is important in terms of adhesion, related stresses and strains and ultimately the longevity of a dental restoration, biomedical implant, or indeed the surrounding tissue. Exposure to body fluids, of course, can also affect stability, leading to the degradation or corrosion of materials within the body. Whilst this could potentially be harmful, e.g., if cytotoxic elements are released, it may alternatively provide a route to the preferential release of beneficial substances. Furthermore, in some cases, the controlled disintegration of a biomaterial is desirable, allowing the removal of an implant, e.g., without the need for further surgery. The presence of cells in the immediate bioenvironment additionally complicates the situation. A considerable amount of current research activity is targeted at the development of coatings or surface treatments to encourage tissue growth. If this is to be achieved by stimulating enhanced cell productivity, determination of the relationship between cell function and surface composition is essential.

  18. Handbook of adhesion

    Packham, D E

    2006-01-01

    This second edition of the successful Handbook of Adhesion provides concise and authoritative articles covering many aspects of the science and technology associated with adhesion and adhesives. It is intended to fill a gap between the necessarily simplified treatment of the student textbook and the full and thorough treatment of the research monograph and review article. The articles are structured in such a way, with internal cross-referencing and external literature references, that the reader can build up a broader and deeper understanding, as their needs require.This second edition includ

  19. Lactobacillus Adhesion to Mucus

    Maxwell L. Van Tassell

    2011-05-01

    Full Text Available Mucus provides protective functions in the gastrointestinal tract and plays an important role in the adhesion of microorganisms to host surfaces. Mucin glycoproteins polymerize, forming a framework to which certain microbial populations can adhere, including probiotic Lactobacillus species. Numerous mechanisms for adhesion to mucus have been discovered in lactobacilli, including partially characterized mucus binding proteins. These mechanisms vary in importance with the in vitro models studied, which could significantly affect the perceived probiotic potential of the organisms. Understanding the nature of mucus-microbe interactions could be the key to elucidating the mechanisms of probiotic adhesion within the host.

  20. Sustainable polysaccharide-based biomaterial recovered from waste aerobic granular sludge as a surface coating material

    Lin, Y.M.; Nierop, K.G.J.; Girbal-Neuhauser, E.; Adriaanse, M.; Van Loosdrecht, M.C.M.

    2015-01-01

    To evaluate the possibility of utilizing polysaccharide-based biomaterial recovered from aerobic granular sludge as a coating material, the morphology, molecular weight distribution and chemical composition of the recovered biomaterial were investigated by atomic force microscopy, size exclusion chr

  1. Biocompatibility of Bacterial Cellulose Based Biomaterials

    Omar P. Troncoso

    2012-12-01

    Full Text Available Some bacteria can synthesize cellulose when they are cultivated under adequate conditions. These bacteria produce a mat of cellulose on the top of the culture medium, which is formed by a three-dimensional coherent network of pure cellulose nanofibers. Bacterial cellulose (BC has been widely used in different fields, such as the paper industry, electronics and tissue engineering due to its remarkable mechanical properties, conformability and porosity. Nanocomposites based on BC have received much attention, because of the possibility of combining the good properties of BC with other materials for specific applications. BC nanocomposites can be processed either in a static or an agitated medium. The fabrication of BC nanocomposites in static media can be carried out while keeping the original mat structure obtained after the synthesis to form the final nanocomposite or by altering the culture media with other components. The present article reviews the issue of biocompatibility of BC and BC nanocomposites. Biomedical aspects, such as surface modification for improving cell adhesion, in vitro and in vivo studies are given along with details concerning the physics of network formation and the changes that occur in the cellulose networks due to the presence of a second phase. The relevance of biocompatibility studies for the development of BC-based materials in bone, skin and cardiovascular tissue engineering is also discussed.

  2. Surface modification of blood-contacting biomaterials by plasma-polymerized superhydrophobic films using hexamethyldisiloxane and tetrafluoromethane as precursors

    Highlights: • Biomaterials modified by nanoparticle-containing plasma polymerized films. • A superhydrophoic film was obtained, and the properties of the coating were examined. • In vitro blood compatibility tests revealed neither platelet adhesion nor fibrinogen adsorption. • Surface modification technology of medical devices: non-cytotoxic and no blood clot formation. - Abstract: This paper proposes a plasma polymerization system that can be used to modify the surface of the widely used biomaterial, polyurethane (PU), by employing low-cost hexamethyldisiloxane (HMDSO) and tetrafluoromethane (CF4) as precursors; this system features a pulsed-dc power supply. Plasma-polymerized HMDSO/CF4 (pp-HC) with coexisting micro- and nanoscale morphology was obtained as a superhydrophobic coating material by controlling the HMDSO/CF4 (fH) monomer flow ratio. The developed surface modification technology can be applied to medical devices, because it is non-cytotoxic and has favorable hemocompatibility, and no blood clots form when the device surface direct contacts. Experimental results reveal that the obtained pp-HC films contained SiOx nanoparticles randomly dispersed on the micron-scale three-dimensional network film surface. The −CF functional group, −CF2 bonding, and SiOx were detected on the film surface. The maximal water contact angle of the pp-HC coating was 161.2°, apparently attributable to the synergistic effect of the coexisting micro- and nanoscale surface morphology featuring a low surface-energy layer. The superhydrophobic and antifouling characteristics of the coating were retained even after it was rubbed 20 times with a steel wool tester. Results of in vitro cytotoxicity, fibrinogen adsorption, and platelet adhesion tests revealed favorable myoblast cell proliferation and the virtual absence of fibrinogen adsorption and platelet adhesion on the pp-HC coated specimens. These quantitative findings imply that the pp-HC coating can potentially

  3. Surface modification of blood-contacting biomaterials by plasma-polymerized superhydrophobic films using hexamethyldisiloxane and tetrafluoromethane as precursors

    Hsiao, Chaio-Ru [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China); Lin, Cheng-Wei [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); Chou, Chia-Man, E-mail: cmchou@vghtc.gov.tw [Department of Surgery, Taichung Veterans General Hospital, No. 1650, Sec. 4, Taiwan Boulevard, Seatwen District, Taichung City 40705, Taiwan (China); Department of Medicine, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Beitou District, Taipei City 11221, Taiwan (China); Chung, Chi-Jen, E-mail: cjchung@seed.net.tw [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); He, Ju-Liang [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China)

    2015-08-15

    Highlights: • Biomaterials modified by nanoparticle-containing plasma polymerized films. • A superhydrophoic film was obtained, and the properties of the coating were examined. • In vitro blood compatibility tests revealed neither platelet adhesion nor fibrinogen adsorption. • Surface modification technology of medical devices: non-cytotoxic and no blood clot formation. - Abstract: This paper proposes a plasma polymerization system that can be used to modify the surface of the widely used biomaterial, polyurethane (PU), by employing low-cost hexamethyldisiloxane (HMDSO) and tetrafluoromethane (CF{sub 4}) as precursors; this system features a pulsed-dc power supply. Plasma-polymerized HMDSO/CF{sub 4} (pp-HC) with coexisting micro- and nanoscale morphology was obtained as a superhydrophobic coating material by controlling the HMDSO/CF{sub 4} (f{sub H}) monomer flow ratio. The developed surface modification technology can be applied to medical devices, because it is non-cytotoxic and has favorable hemocompatibility, and no blood clots form when the device surface direct contacts. Experimental results reveal that the obtained pp-HC films contained SiO{sub x} nanoparticles randomly dispersed on the micron-scale three-dimensional network film surface. The −CF functional group, −CF{sub 2} bonding, and SiO{sub x} were detected on the film surface. The maximal water contact angle of the pp-HC coating was 161.2°, apparently attributable to the synergistic effect of the coexisting micro- and nanoscale surface morphology featuring a low surface-energy layer. The superhydrophobic and antifouling characteristics of the coating were retained even after it was rubbed 20 times with a steel wool tester. Results of in vitro cytotoxicity, fibrinogen adsorption, and platelet adhesion tests revealed favorable myoblast cell proliferation and the virtual absence of fibrinogen adsorption and platelet adhesion on the pp-HC coated specimens. These quantitative findings imply

  4. Adhesion of Lunar Dust

    Walton, Otis R.

    2007-04-01

    This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and/or tribo-electric charging) are likely to be the major contributors to the transport of dust particles. If fine regolith particles are deposited on a surface, then surface energy-related (e.g., van der Walls) adhesion forces and static-electric-image forces are likely to be the strongest contributors to adhesion. Some measurement techniques are offered to quantify the strength of adhesion forces. And finally some dust removal techniques are discussed.

  5. Leukocyte Adhesion Deficiency (LAD)

    ... Content Marketing Share this: Main Content Area Leukocyte Adhesion Deficiency (LAD) LAD is an immune deficiency in ... are slow to heal also may have LAD. Treatment and Research Doctors prescribe antibiotics to prevent and ...

  6. Difficulties in the Translation of Functionalized Biomaterials into Regenerative Medicine Clinical Products

    Ratcliffe, Anthony

    2011-01-01

    There are many ways to influence cell activities, and biomaterials with functional groups attached is an attractive method that clearly has the ability to modulate cell behavior. The evidence is clear that biomaterials, with or without growth factors and cells, have resulted in numerous products for the regenerative medicine field. In contrast the functionalized biomaterial products remain in the development phase.

  7. Management of adhesive capsulitis

    Neviaser, Andrew

    2015-01-01

    Kristen L Stupay,1 Andrew S Neviaser2 1Tulane University School of Medicine, New Orleans, LA, USA; 2George Washington University Medical Faculty Associates, Washington, DC, USA Abstract: Adhesive capsulitis of the shoulder is a condition of capsular contracture that reduces both active and passive glenohumeral motion. The cause of adhesive capsulitis is not known but it is strongly associated with endocrine abnormalities such as diabetes. Diverse terminology and the absence of definitive cri...

  8. Fundamental monomeric biomaterial diagnostics by radio frequency signal analysis.

    Ji, Jae-Hoon; Shin, Kyeong-Sik; Kang, Shinill; Lee, Soo Hyun; Kang, Ji Yoon; Kim, Sinyoung; Jun, Seong Chan

    2016-08-15

    We present a new diagnostic technique of fundamental monomeric biomaterials that do not rely on any enzyme or chemical reaction. Instead, it only uses radio frequency (RF) signal analysis. The detection and classification of basic biomaterials, such as glucose and albumin, were demonstrated. The device was designed to generate a strong resonance response with glucose solution and fabricated by simple photolithography with PDMS (Polydimethylsiloxane) well. It even was used to detect the level of glucose in mixtures of glucose and albumin and in human serum, and it operated properly and identified the glucose concentration precisely. It has a detection limit about 100μM (1.8mg/dl), and a sensitivity about 58MHz per 1mM of glucose and exhibited a good linearity in human blood glucose level. In addition, the intrinsic electrical properties of biomaterials can be investigated by a de-embedding technique and an equivalent circuit analysis. The capacitance of glucose containing samples exhibited bell-shaped Gaussian dispersion spectra around 2.4GHz. The Albumin solution did not represent a clear dispersion spectra compared to glucose, and the magnitude of resistance and inductance of albumin was higher than that of other samples. Other parameters also represented distinguishable patterns to classify those biomaterials. It leads us to expect future usage of our technique as a pattern-recognizing biosensor. PMID:27111728

  9. Cell Physiology and Interactions of Biomaterials and Matrices

    Hunkeler, D.; Vaňková, Radomíra

    2003-01-01

    Roč. 28, č. 6 (2003), s. 193-197. ISSN 0032-3918 R&D Projects: GA MŠk OC 840.20 Institutional research plan: CEZ:AV0Z5038910 Keywords : Biomaterials * Cell physiology * Encapsulation Subject RIV: CE - Biochemistry

  10. Assessing immunological properties of biomaterials for bone regeneration applications

    Šírová, Milada

    Cambridge : ELSEVIER - WoodHead Publishing, 2014 - (Dubruel, P.; Van Vlierberghe, S.), s. 324-348 ISBN 978-0-85709-804-7 Institutional support: RVO:61388971 Keywords : immunocompatibility of biomaterials * acute and chronic inflammation * maturation of dendritic cells Subject RIV: EC - Immunology

  11. In vitro biocompatibility testing of biomaterials and medical devices.

    Müller, U

    2008-01-01

    Biomaterials used for medical devices must be thoroughly tested according to ISO 10993 before their introduction so that any negative effects on the body are known about and prevented. By using in vitro laboratory tests, dangers for patients and unnecessary animal experiments can be avoided. Here, in vitro tests for cell compatibility (cytotoxicity) and blood compatibility (haemocompatibility) are described. PMID:18605289

  12. A Multidisciplined Teaching Reform of Biomaterials Course for Undergraduate Students

    Li, Xiaoming; Zhao, Feng; Pu, Fang; Liu, Haifeng; Niu, Xufeng; Zhou, Gang; Li, Deyu; Fan, Yubo; Feng, Qingling; Cui, Fu-zhai; Watari, Fumio

    2015-01-01

    The biomaterials science has advanced in a high speed with global science and technology development during the recent decades, which experts predict to be more obvious in the near future with a more significant position for medicine and health care. Although the three traditional subjects, such as medical science, materials science and biology…

  13. Current and future biocompatibility aspects of biomaterials for hip prosthesis

    Amit Aherwar

    2015-12-01

    Full Text Available The field of biomaterials has turn into an electrifying area because these materials improve the quality and longevity of human life. The first and foremost necessity for the selection of the biomaterial is the acceptability by human body. However, the materials used in hip implants are designed to sustain the load bearing function of human bones for the start of the patient’s life. The most common classes of biomaterials used are metals, polymers, ceramics, composites and apatite. These five classes are used individually or in combination with other materials to form most of the implantation devices in recent years. Numerous current and promising new biomaterials i.e. metallic, ceramic, polymeric and composite are discussed to highlight their merits and their frailties in terms of mechanical and metallurgical properties in this review. It is concluded that current materials have their confines and there is a need for more refined multi-functional materials to be developed in order to match the biocompatibility, metallurgical and mechanical complexity of the hip prosthesis.

  14. Immunological aspects related to the biomaterials used in bone additions

    Papakoca, Kiro; Neamtu, Raluca; Drafta, Sergiu; Dimitriu, Bogdan; Mihai, Augustin; Durbaca, Ioana

    2010-01-01

    In the last two decades, biomaterials have become of great importance for medical practice. thus, biomatrials used for bone addition or bone augmentation are used not only in orthopedics or traumatology, but also in dental medicine, especially in oral implantology to repair some bone defects small or vast in scope.

  15. All-biomaterial supercapacitor derived from bacterial cellulose.

    Wang, Xiangjun; Kong, Debin; Zhang, Yunbo; Wang, Bin; Li, Xianglong; Qiu, Tengfei; Song, Qi; Ning, Jing; Song, Yan; Zhi, Linjie

    2016-04-28

    An all-biomaterial originated film supercapacitor has been successfully fabricated for the first time based on a unique three-dimensional bacterial cellulose (BC) derived electrode and a novel BC-based gel electrolyte. The obtained supercapacitor displays an excellent specific capacitance of 289 mF cm(-2) and an improved solution resistance of 7 Ω. PMID:27093428

  16. Biomaterials for the Treatment of Alzheimer’s Disease

    Hadavi, Darya; Poot, André A.

    2016-01-01

    Alzheimer’s disease (AD) as a progressive and fatal neurodegenerative disease represents a huge unmet need for treatment. The low efficacy of current treatment methods is not only due to low drug potency but also due to the presence of various obstacles in the delivery routes. One of the main barriers is the blood–brain barrier. The increasing prevalence of AD and the low efficacy of current therapies have increased the amount of research on unraveling of disease pathways and development of treatment strategies. One of the interesting areas for the latter subject is biomaterials and their applications. This interest originates from the fact that biomaterials are very useful for the delivery of therapeutic agents, such as drugs, proteins, and/or cells, in order to treat diseases and regenerate tissues. Recently, manufacturing of nano-sized delivery systems has increased the efficacy and delivery potential of biomaterials. In this article, we review the latest developments with regard to the use of biomaterials for the treatment of AD, including nanoparticles and liposomes for delivery of therapeutic compounds and scaffolds for cell delivery strategies. PMID:27379232

  17. Towards 4th generation biomaterials: a covalent hybrid polymer-ormoglass architecture

    Sachot, N.; Mateos-Timoneda, M. A.; Planell, J. A.; Velders, A. H.; Lewandowska, M.; Engel, E.; Castaño, O.

    2015-09-01

    Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed on its surface mimicking the structure of the ECM of bone. Here, polylactic acid electrospun fibers have been successfully and reproducibly coated with a bioactive organically modified glass (ormoglass, Si-Ca-P2 system) covalently. In comparison with the pure polymeric mats, the fibers obtained showed improved hydrophilicity and mechanical properties, bioactive ion release, exhibited a nanoroughness and enabled good cell adhesion and spreading after just one day of culture (rMSCs and rEPCs). The fibers were coated with different ormoglass compositions to tailor their surface properties (roughness, stiffness, and morphology) by modifying the experimental parameters. Knowing that cells modulate their behavior according to the exposed physical and chemical signals, the development of this instructive material is a valuable advance in the design of functional regenerative biomaterials.Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed

  18. Biomaterials for orthopaedic implants and bone regeneration

    Sargeant, Timothy David

    For bone regeneration, there is need for biodegradable, synthetic scaffolds that direct the formation of de novo mineralized tissue. Orthopaedic implants additionally require mechanical function. The work described herein attempts to address both of these needs. The general strategy involves integrating molecularly designed tissue engineering scaffolds with porous metallic foams to create hybrid materials to direct cellular behavior. Peptide amphiphiles (PAs) that self-assemble into nanofibers were designed to template hydroxyapatite mineral under biological conditions. The molecular design incorporated either serine (S) or phosphoserine S(P) and was mixed with RGDS-bearing PA to evaluate of the key parameters for mineral formation. This led to the discovery of nanoscale hydroxyapatite spheres templated on both S- and S(P)-bearing PA nanofibers. Stem cells were encapsulated in these gels and RT-PCR showed osteoblastic differentiation in all samples. Osteoblast maturation was increased in S-bearing PA compared to S(P)-bearing PA, although the reason is not yet understood. A method to create robust PA nanofiber coatings on NiTi was developed by optimizing the NiTi oxide surface chemistry, optimizing silane vapor deposition, and covalently attaching the PAs to the silanized substrate. The surfaces were characterized by XPS, SIMS, AFM, and fluorimetry. In vitro experiments demonstrated the importance of covalent attachment for cellular adhesion and proved the materials were not cytotoxic. Orthopaedic hybrid materials were created by triggering PA self-assembly within the interconnected pores of Ti foams developed by the Dunand research group. In vitro experiments demonstrate that pre-osteoblasts adhere to, proliferate on, and migrate into PA-Ti hybrids made with S(P)- and RGDS-bearing PA mixtures. The cells differentiate into mature osteoblasts and remain viable up to 28 days. In vivo studies using a rat model demonstrate osteointegration and boney ingrowth into bare

  19. Surface modification of blood-contacting biomaterials by plasma-polymerized superhydrophobic films using hexamethyldisiloxane and tetrafluoromethane as precursors

    Hsiao, Chaio-Ru; Lin, Cheng-Wei; Chou, Chia-Man; Chung, Chi-Jen; He, Ju-Liang

    2015-08-01

    This paper proposes a plasma polymerization system that can be used to modify the surface of the widely used biomaterial, polyurethane (PU), by employing low-cost hexamethyldisiloxane (HMDSO) and tetrafluoromethane (CF4) as precursors; this system features a pulsed-dc power supply. Plasma-polymerized HMDSO/CF4 (pp-HC) with coexisting micro- and nanoscale morphology was obtained as a superhydrophobic coating material by controlling the HMDSO/CF4 (fH) monomer flow ratio. The developed surface modification technology can be applied to medical devices, because it is non-cytotoxic and has favorable hemocompatibility, and no blood clots form when the device surface direct contacts. Experimental results reveal that the obtained pp-HC films contained SiOx nanoparticles randomly dispersed on the micron-scale three-dimensional network film surface. The sbnd CF functional group, sbnd CF2 bonding, and SiOx were detected on the film surface. The maximal water contact angle of the pp-HC coating was 161.2°, apparently attributable to the synergistic effect of the coexisting micro- and nanoscale surface morphology featuring a low surface-energy layer. The superhydrophobic and antifouling characteristics of the coating were retained even after it was rubbed 20 times with a steel wool tester. Results of in vitro cytotoxicity, fibrinogen adsorption, and platelet adhesion tests revealed favorable myoblast cell proliferation and the virtual absence of fibrinogen adsorption and platelet adhesion on the pp-HC coated specimens. These quantitative findings imply that the pp-HC coating can potentially prevent the formation of thrombi and provide an alternative means of modifying the surfaces of blood-contacting biomaterials.

  20. Adhesion of human gingival fibroblasts/Streptococcus mitis co-culture on the nanocomposite system Chitlac-nAg

    Cataldi, Amelia; Gallorini, Marialucia; Di Giulio, Mara; Guarnieri, Simone; Mariggiò, Maria Addolorata; Traini, Tonino; Di Pietro, Roberta; Cellini, Luigina; Marsich, Eleonora; SANCILIO, SILVIA

    2016-01-01

    Composite materials are increasingly used as dental restoration. In the field of biomaterials, infections remain the main reason of dental devices failure. Silver, in the form of nanoparticles (AgNPs), ions and salt, well known for its antimicrobial properties, is used in several medical applications in order to avoid bacterial infection. To reduce both bacterial adhesion to dental devices and cytotoxicity against eukaryotic cells, we coated BisGMA/TEGDMA methacrylic thermosets with a new mat...

  1. Electrically Conductive Epoxy Adhesives

    Lan Bai

    2011-02-01

    Full Text Available Conductive adhesives are widely used in electronic packaging applications such as die attachment and solderless interconnections, component repair, display interconnections, and heat dissipation. The effects of film thickness as functions of filler volume fraction, conductive filler size, shape, as well as uncured adhesive matrix viscosity on the electrical conduction behavior of epoxy-based adhesives are presented in this work. For this purpose, epoxy-based adhesives were prepared using conductive fillers of different size, shape, and types, including Ni powder, flakes, and filaments, Ag powder, and Cu powder. The filaments were 20 μm in diameter, and 160 or 260 μm in length. HCl and H3PO4 acid solutions were used to etch and remove the surface oxide layers from the fillers. The plane resistance of filled adhesive films was measured using the four-point method. In all cases of conductive filler addition, the planar resistivity levels for the composite adhesive films increased when the film thickness was reduced. The shape of resistivity-thickness curves was negative exponential decaying type and was modeled using a mathematical relation. The relationships between the conductive film resistivities and the filler volume fractions were also derived mathematically based on the experimental data. Thus, the effects of surface treatment of filler particles, the type, size, shape of fillers, and the uncured epoxy viscosity could be included empirically by using these mathematical relations based on the experimental data. By utilizing the relations we proposed to model thickness-dependent and volume fraction-dependent conduction behaviors separately, we were able to describe the combined and coupled volume fraction-film thickness relationship mathematically based on our experimental data.

  2. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  3. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

    Premnath, Priyatha, E-mail: priyatha.premnath@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Tavangar, Amirhossein, E-mail: atavanga@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Tan, Bo, E-mail: tanbo@ryerson.ca [Nanocharacterization Laboratory, Department of Aerospace Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada); Venkatakrishnan, Krishnan, E-mail: venkat@ryerson.ca [Micro/Nanofabrication Laboratory, Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3 (Canada)

    2015-09-10

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  4. A Tubular Biomaterial Construct Exhibiting a Negative Poisson’s Ratio

    Lee, Jin Woo; Soman, Pranav; Park, Jeong Hun; Chen, Shaochen; Cho, Dong-Woo

    2016-01-01

    Developing functional small-diameter vascular grafts is an important objective in tissue engineering research. In this study, we address the problem of compliance mismatch by designing and developing a 3D tubular construct that has a negative Poisson’s ratio νxy (NPR). NPR constructs have the unique ability to expand transversely when pulled axially, thereby resulting in a highly-compliant tubular construct. In this work, we used projection stereolithography to 3D-print a planar NPR sheet composed of photosensitive poly(ethylene) glycol diacrylate biomaterial. We used a step-lithography exposure and a stitch process to scale up the projection printing process, and used the cut-missing rib unit design to develop a centimeter-scale NPR sheet, which was rolled up to form a tubular construct. The constructs had Poisson’s ratios of -0.6 ≤ νxy ≤ -0.1. The NPR construct also supports higher cellular adhesion than does the construct that has positive νxy. Our NPR design offers a significant advance in the development of highly-compliant vascular grafts. PMID:27232181

  5. Effect of carbodiimide-derivatized hyaluronic acid gelatin on preventing postsurgical intra-abdominal adhesion formation and promoting healing in a rat model.

    Yuan, Fang; Lin, Long-Xiang; Zhang, Hui-Hui; Huang, Dan; Sun, Yu-Long

    2016-05-01

    Adhesions often occur after abdominal surgery. It could cause chronic pelvic pain, intestinal obstruction, and infertility. A hydrogel biomaterial, carbodiimide-derivatized hyaluronic acid gelatin (cd-HA gelatin), has been successfully used to reduce adhesion formation after flexor tendon grafting. This study investigated the efficacy of cd-HA gelatin in preventing postsurgical peritoneal adhesions in a rat model. The surgical traumas were created on the underlying muscle of the abdominal wall and the serosal layer of the cecum. The wounds were covered with or without cd-HA gelatin. Animals were euthanized at day 14 after surgery. Adhesion formation was assessed with adhesion degree and adhesion breaking strength. The healing of abdominal wall was evaluated with biomechanical testing and histological analysis. The adhesions occurred in all rats (n = 12) without cd-HA gelatin treatment. The application of cd-HA gelatin significantly reduced the adhesion rate from 100% to 58%. The decrease of adhesion breaking strength also manifested that cd-HA gelatin could reduce postsurgical intra-abdominal adhesion formation. Moreover, it was found that cd-HA gelatin was a safe material and could promote tissue healing. The cd-HA gelatin hydrogel could reduce the formation of intra-abdominal adhesions without adversely effects on wound healing. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1175-1181, 2016. PMID:26749008

  6. Adhesive B-doped DLC films on biomedical alloys used for bone fixation

    A A Ahmad; A M Alsaad

    2007-08-01

    The long-term failure of the total hip and knee prostheses is attributed to the production of wear particles at the articulating interface between the metals, ceramics and polymers used for surgical implants and bone-fixtures. Therefore, finding an adhesive and inert coating material that has low frictional coefficient should dramatically reduce the production of wear particles and hence, prolong the life time of the surgical implants. The novel properties of the non-toxic diamond-like carbon (DLC) coatings have proven to be excellent candidates for biomedical applications. However, they have poor adhesion strength to the alloys and biomaterials. The addition of a thin interfacial layer such as Si, Ti, TiN, Mo and Cu/Cr and/or adding additives such as Si, F, N, O, W, V, Co, Mo, Ti or their combinations to the DLC films has been found to increase the adhesion strength substantially. In our study, grade 316L stainless steel and grade 5 titanium alloy (Ti–6Al–4V) were used as biomaterial substrates. They were coated with DLC films containing boron additives at various levels using various Si interfacial layer thicknesses. The best film adhesion was achieved at 8% and 20% on DLC coated Ti–6Al–4V and grade 316L substrates, respectively. It has been demonstrated that doping the DLC with boron increases their adhesion strength to both substrates even without silicon interfacial layer and increases it substantially with optimum silicon layer thickness. The adhesion strength is also correlated with the hydrogen contents in the B-DLC films. It is found to reach its maximum value of 700 kg/cm2 and 390 kg/cm2 at 2/7 and 3/6 for CH4/Ar partial pressures (in mTorr ratio) for Ti–6Al–4V and 316L substrates, respectively.

  7. Validation of the Osteopenia Sheep Model for Orthopaedic Biomaterial Research

    Ding, Ming; Danielsen, C.C.; Cheng, L.;

    2009-01-01

    resemble osteoporosis in humans. This study aimed to validate glucocorticoid-induced osteopenia sheep model for orthopaedic implant and biomaterial research. We hypothesized that a 7-month GC treatment together with restricted diet but without OVX would induce osteopenia. Materials and Methods: Eighteen......Validation of the Osteopenia Sheep Model for Orthopaedic Biomaterial Research +1Ding, M; 2Danielsen, CC; 1Cheng, L; 3Bollen, P; 4Schwarz, P; 1Overgaard, S +1Dept of Orthopaedics O, Odense University Hospital, Denmark, 2Dept of Connective Tissue Biology, University of Aarhus, Denmark, 3Biomedicine...... patients do not have a normal bone quality that in many cases are due to osteoporosis (OP) even in osteoarthritic joints. Although a variety of ovariectomized (OVX) animals has been used to study osteoporosis, there is a great need for suitable large animal models with adequate bone size that closely...

  8. Fabrication of PEGylated fibrinogen: a versatile injectable hydrogel biomaterial.

    Mironi-Harpaz, Iris; Berdichevski, Alexandra; Seliktar, Dror

    2014-01-01

    Hydrogels are one of the most versatile biomaterials in use for tissue engineering and regenerative medicine. They are assembled from either natural or synthetic polymers, and their high water content gives these materials practical advantages in numerous biomedical applications. Semisynthetic hydrogels, such as those that combine synthetic and biological building blocks, have the added advantage of controlled bioactivity and material properties. In myocardial regeneration, injectable hydrogels premised on a semisynthetic design are advantageous both as bioactive bulking agents and as a delivery vehicle for controlled release of bioactive factors and/or cardiomyocytes. A new semisynthetic hydrogel based on PEGylated fibrinogen has been developed to address the many requirements of an injectable biomaterial in cardiac restoration. This chapter highlights the fundamental aspects of making this biomimetic hydrogel matrix for cardiac applications. PMID:25070327

  9. Nanoindentation Studies of TNZ and Ti2448 Biomaterials After Magnetoelectropolishing

    Hryniewicz T.

    2014-10-01

    Full Text Available This work presents the nanoindentation results of two newly developed titanium alloy biomaterials, TNZ and Ti2448, after different surface treatments. The investigations were performed on the samples, AR – as received, MP – after abrasive polishing, EP – after a standard electropolshing, and MEP – after magnetoelectropolishing. The electropolishing processes, both EP and MEP, were conducted in the same proprietary electrolyte based on concentrated sulfuric acid. The mechanical properties of the titanium alloys biomaterials demonstrated an evident dependence on the surface treatment method, with MEP samples revealing extremely different behaviour and mechanical properties. Such a different mechanical behaviour may mean completely different composition and thickness of the surface film formed on the studied samples after MEP

  10. APPLICATIONS OF BIOTECHNOLOGY IN DEVELOPMENT OF BIOMATERIALS: NANOTECHNOLOGY AND BIOFILMS

    Brigmon, R.; Berry, T.; Narayan, R.

    2010-11-29

    Biotechnology is the application of biological techniques to develop new tools and products for medicine and industry. Due to various properties including chemical stability, biocompatibility, and specific activity, e.g. antimicrobial properties, many new and novel materials are being investigated for use in biosensing, drug delivery, hemodialysis, and other medical applications. Many of these materials are less than 100 nanometers in size. Nanotechnology is the engineering discipline encompassing designing, producing, testing, and using structures and devices less than 100 nanometers. One of the challenges associated with biomaterials is microbial contamination that can lead to infections. In recent work we have examined the functionalization of nanoporous biomaterials and antimicrobial activities of nanocrystalline diamond materials. In vitro testing has revealed little antimicrobial activity against Pseudomonas fluorescens bacteria and associated biofilm formation that enhances recalcitrance to antimicrobial agents including disinfectants and antibiotics. Laser scanning confocal microscopy studies further demonstrated properties and characteristics of the material with regard to biofilm formation.

  11. Modelling the regenerative niche: a major challenge in biomaterials research.

    Kirkpatrick, C James

    2015-12-01

    By definition, biomaterials are developed for clinical application. In the field of regenerative medicine their principal function is to play a significant, and, if possible, an instructive role in tissue healing. In the last analysis the latter involves targeting the 'regenerative niche'. The present paper will address the problem of simulating this niche in the laboratory and adopts a life science approach involving the harnessing of heterotypic cellular communication to achieve this, that is, the ability of cells of different types to mutually influence cellular functions. Thus, co-culture systems using human cells are the methodological focus and will concern four exemplary fields of regeneration, namely, bone, soft tissue, lower respiratory tract and airway regeneration. The working hypothesis underlying this approach is that in vitro models of higher complexity will be more clinically relevant than simple monolayer cultures of transformed cell lines in testing innovative strategies with biomaterials for regeneration. PMID:26816650

  12. Bioinspired phospholipid polymer biomaterials for making high performance artificial organs

    K Ishihara

    2000-01-01

    Full Text Available Novel polymer biomaterials, which can be used in contact with blood, are prepared with strong inspiration from the surface structure of biomembrane. That is, the polymers with a phospholipid polar group in the side chain, 2-methacrylooyloxyethyl phosphorylcholine (MPC polymers were synthesized. The MPC polymers can inhibit surface-induced clot formation effectively, when they are in contact with blood even in the absence of an anticoagulant. This phenomenon was due to the reduction of plasma protein and suppression of denaturation of adsorbed proteins, that is the MPC polymers interact with blood components very mildly. As the molecular structure of the MPC polymer was easily designed by changing the monomer units and their composition, it could be applied to surface modification of artificial organs and biomedical devices for improving blood and tissue compatibility. Thus, the MPC polymers are useful polymer biomaterials for manufacturing high performance artificial organs and biomedical devices to provide safe medical treatments.

  13. Global gene expression analysis for evaluation and design of biomaterials

    Nobutaka Hanagata, Taro Takemura and Takashi Minowa

    2010-01-01

    Full Text Available Comprehensive gene expression analysis using DNA microarrays has become a widespread technique in molecular biological research. In the biomaterials field, it is used to evaluate the biocompatibility or cellular toxicity of metals, polymers and ceramics. Studies in this field have extracted differentially expressed genes in the context of differences in cellular responses among multiple materials. Based on these genes, the effects of materials on cells at the molecular level have been examined. Expression data ranging from several to tens of thousands of genes can be obtained from DNA microarrays. For this reason, several tens or hundreds of differentially expressed genes are often present in different materials. In this review, we outline the principles of DNA microarrays, and provide an introduction to methods of extracting information which is useful for evaluating and designing biomaterials from comprehensive gene expression data.

  14. All-biomaterial supercapacitor derived from bacterial cellulose

    Wang, Xiangjun; Kong, Debin; Zhang, Yunbo; Wang, Bin; Li, Xianglong; Qiu, Tengfei; Song, Qi; Ning, Jing; Song, Yan; Zhi, Linjie

    2016-04-01

    An all-biomaterial originated film supercapacitor has been successfully fabricated for the first time based on a unique three-dimensional bacterial cellulose (BC) derived electrode and a novel BC-based gel electrolyte. The obtained supercapacitor displays an excellent specific capacitance of 289 mF cm-2 and an improved solution resistance of 7 Ω.An all-biomaterial originated film supercapacitor has been successfully fabricated for the first time based on a unique three-dimensional bacterial cellulose (BC) derived electrode and a novel BC-based gel electrolyte. The obtained supercapacitor displays an excellent specific capacitance of 289 mF cm-2 and an improved solution resistance of 7 Ω. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01485b

  15. Simplified process for preparation of schizophyllan solutions for biomaterial applications.

    Sutivisedsak, Nongnuch; Leathers, Timothy D; Biresaw, Girma; Nunnally, Melinda S; Bischoff, Kenneth M

    2016-04-01

    Schizophyllan is a biopolymer commercially produced for pharmaceutical and cosmetics uses. However, schizophyllan also has potential biomaterial applications. Schizophyllan is conventionally produced from glucose and recovered by diafiltration and ultrafiltration to produce a highly purified product. Here we demonstrate a simplified process for preparation of schizophyllan solutions for biomaterial applications. Schizophyllan was produced in 1.5-L bioreactors from distiller's dried grains with solubles (DDGS), an abundant coproduct of dry grind fuel ethanol production. Downstream processing eliminated filtration and concentration steps, providing solutions containing 4.2 ± 0.3 g schizophyllan/L. Solutions contained high-molecular-weight schizophyllan and exhibited viscosity properties similar to those of commercial schizophyllan. Schizophyllan solutions showed promise as a component of biolubricants in friction and wear tests and by dynamic surface and interfacial tension measurements. PMID:25830418

  16. Adhesive strength of bioactive oxide layers fabricated on TNTZ alloy by three different alkali-solution treatments.

    Takematsu, E; Cho, K; Hieda, J; Nakai, M; Katsumata, K; Okada, K; Niinomi, M; Matsushita, N

    2016-08-01

    Bioactive oxide layers were fabricated on Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) by three different alkali solution treatments: hydrothermal (H), electrochemical (E), and hydrothermal-electrochemical (HE). The adhesive strength of the oxide layer to the TNTZ substrate was measured to determine whether this process achieves sufficient adhesive strength for implant materials. Samples subjected to the HE process, in which a current of 15mA/cm(2) was applied at 90°C for 1h (HE90-1h), exhibited a comparatively higher adhesive strength of approximately 18MPa while still maintaining a sufficiently high bioactivity. Based on these results, an oxide layer fabricated on TNTZ by HE90-1h is considered appropriate for practical biomaterial application, though thicker oxide layers with many cracks can lead to a reduced adhesive strength. PMID:26866453

  17. Nano-spectroscopy and chemical nanoscopy of biomaterials

    Bründermann, E.; Schmidt, D. A.; Kopf, I.; Havenith, M.

    2010-02-01

    A scanning near-field infrared microscopy experimental station will be integrated into the ANKA-IR2 beamline to combine broadband synchrotron radiation with near-field microscopy. Other microscopy techniques also available in the station will be compared. We have performed nano-spectroscopy investigating biomaterials like self-assembled monolayers and nanoscale lipid membranes. Coherent synchrotron radiation (CSR) at ANKA has been measured to determine power and beam profile for coupling terahertz radiation to the nanoscope.

  18. Advantages of RGD peptides for directing cell association with biomaterials

    Bellis, Susan L.

    2011-01-01

    Despite many years of in vitro research confirming the effectiveness of RGD in promoting cell attachment to a wide variety of biomaterials, animal studies evaluating tissue responses to implanted RGD-functionalized substrates have yielded more variable results The goals of this report are to present some of the reasons why cell culture studies may not always reliably predict in vivo responses, and more importantly, to highlight potential applications that may benefit from the use of RGD pepti...

  19. Polysaccharide-based biomaterials with antimicrobial and antioxidant properties

    Véronique Coma

    2013-01-01

    Active packaging is one of the responses to the recent food-borne microbial outbreaks and to the consumer’s demand for high quality food and for packaging that is more advanced and creative than what is currently offered. Moreover, with the recent increase in ecological awareness associated with the dramatic decrease in fossil resources, research has turned towards the elaboration of more natural materials. This paper provides a short review of biomaterials exhibiting antimicrobial and antiox...

  20. Structural changes in sheep tibia bone undergoing biomaterial scaffold implant

    Maxwell, Craig, 1984-

    2012-01-01

    Bone fracture is a common occurrence with most people having, or knowing someone who has experienced it. This thesis displays quantitative results on the growth and strength of new material formed in a fracture gap by analysing the density and volume of the implanted biomaterial scaffold and the new material formed alongside gait and Finite Element Analysis (FEA) of external factors which can have an effect on the remodeling process. The main goal of this thesis is to present methods to provi...

  1. APPLICATION OF CHITOSAN-BASED BIOMATERIALS IN BIOARTIFICIAL LIVE

    BAO Zhiming; PAN Jilun; LI Li; YU Yaoting

    2006-01-01

    Bioartificial liver support system (BALS) has the potential to provide temporary support for patients with fulminant hepatic failure and consist of viable hepatocytes and scaffolding materials for hepatocytes attachment. Various scaffolding materials are used in BALS, including chitosan,which is easily obtained by deacetylation of chitin and widely applied in biomedical applications. In this paper, we introduce and discuses chitosan-based biomaterials for BALS application.

  2. Musculoskeletal Regenerative Engineering: Biomaterials, Structures, and Small Molecules

    Roshan James; Laurencin, Cato T.

    2014-01-01

    Musculoskeletal tissues are critical to the normal functioning of an individual and following damage or degeneration they show extremely limited endogenous regenerative capacity. The future of regenerative medicine is the combination of advanced biomaterials, structures, and cues to re-engineer/guide stem cells to yield the desired organ cells and tissues. Tissue engineering strategies were ideally suited to repair damaged tissues; however, the substitution and regeneration of large tissue vo...

  3. Synthesis and Morphological Characterization of Block Copolymers for Improved Biomaterials

    Schricker, Scott; Palacio, Manuel; Thirumamagal, B.T.S.; Bhushan, Bharat

    2010-01-01

    Biocompatible polymers are known to act as scaffolds for the regeneration and growth of bone. Block copolymers are of interest as scaffold materials because a number of the blocks are biocompatible, and their nanostructure is easily tunable with synthetic techniques. In this paper, we report the synthesis of a novel class of biomaterials from block copolymers containing a hydrophobic block of methyl methacrylate and a hydrophilic block of either acrylic acid, dimethyl acrylamide, or 2-hydroxy...

  4. Bioactive Titania Layer Fabricated on Metallic Biomaterials by Electrodeposition

    Miyazaki, T.; Otsuyama, T.; Ishida, E.

    2009-01-01

    Improvement of bone integration ability of metallic biomaterials is needed for long-term stable fIxation to bone tissues. Essential prerequisite for materials to show bone-integrating bioactivity is formation of apatite layer on their surfaces in body environments. Several functional groups have potential to trigger the apatite nucleation. In the present study, we attempted fabrication of bioactive titania layer which provides Ti-OH groups effective for the apatite formation on bioinert metal...

  5. Bone formation following implantation of bone biomaterials into extraction sites

    Molly, Liene; Vandromme, Heleen; Quirynen, Marc; Schepers, Evert; Adams, Jessica L; van Steenberghe, Daniel

    2008-01-01

    Background: Adequate bone volume is imperative for the osseointegration of endosseous implants, but post-extraction resorption and remodeling may challenge implant placement. The use of bone biomaterials has been advocated to fill extraction sites and to enhance primary implant stability during osseointegration. The objective of the case series was to evaluate bone formation histologically and biomechanically in extraction sites following implantation of three commercially available bone biom...

  6. Scanning Probe Microscopy as a Tool for Investigation of Biomaterials

    Veronika Novotna; Alexandr Knapek; Pavel Tomanek; Sarka Safarova

    2012-01-01

    Super-microscopic techniques like scanning tunnelling microscopy, atomic force microscopy or scanning near-field optical microscopy allows investigate micro- and/or nano-scale surfaces and structures. In this paper, both Environmental scanning electron microscope (ESEM) and Scanning near field optical microscope (SNOM) have been applied to more closely study of biomaterials. The results of visualization of human osteo-sarcoma cell line (U2OS) are compared. SNOM and ESEM yield different, howev...

  7. Platelet adhesion studies on dipyridamole coated polyurethane surfaces

    Aldenhoff Y. B.J.

    2003-06-01

    Full Text Available Surface modification of polyurethanes (PUs by covalent attachment of dipyridamole (Persantinregistered is known to reduce adherence of blood platelets upon exposure to human platelet rich plasma (PRP. This effect was investigated in further detail. First platelet adhesion under static conditions was studied with four different biomaterial surfaces: untreated PU, PU immobilised with conjugate molecule 1, PU immobilised with conjugate molecule 2, and PU immobilised with conjugate molecule 3. In PU immobilised with 1 dipyridamole is directly linked to the surface, in PU immobilised with 2 there is a short hydrophilic spacer chain in between the surface and the dipyridamole, while conjugate molecule 3 is merely the spacer chain. Scanning electron microscopy (SEM was used to characterise platelet adhesion from human PRP under static conditions, and fluorescence imaging microscopy was used to study platelet adhesion from whole blood under flow. SEM experiments encompassed both density measurements and analysis of the morphology of adherent platelets. In the static experiments the surface immobilised with 2 showed the lowest platelet adherence. No difference between the three modified surfaces emerged from the flow experiments. The surfaces were also incubated with washed blood platelets and labeled with Oregon-Green Annexin V. No capture of Oregon-Green Annexin V was seen, implying that the adhered platelets did not expose any phosphatidyl serine at their exteriour surface.

  8. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-11-01

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects. PMID:26457864

  9. Novel biomaterials: plasma-enabled nanostructures and functions

    Levchenko, Igor; Keidar, Michael; Cvelbar, Uroš; Mariotti, Davide; Mai-Prochnow, Anne; Fang, Jinghua; (Ken Ostrikov, Kostya

    2016-07-01

    Material processing techniques utilizing low-temperature plasmas as the main process tool feature many unique capabilities for the fabrication of various nanostructured materials. As compared with the neutral-gas based techniques and methods, the plasma-based approaches offer higher levels of energy and flux controllability, often leading to higher quality of the fabricated nanomaterials and sometimes to the synthesis of the hierarchical materials with interesting properties. Among others, nanoscale biomaterials attract significant attention due to their special properties towards the biological materials (proteins, enzymes), living cells and tissues. This review briefly examines various approaches based on the use of low-temperature plasma environments to fabricate nanoscale biomaterials exhibiting high biological activity, biological inertness for drug delivery system, and other features of the biomaterials make them highly attractive. In particular, we briefly discuss the plasma-assisted fabrication of gold and silicon nanoparticles for bio-applications; carbon nanoparticles for bioimaging and cancer therapy; carbon nanotube-based platforms for enzyme production and bacteria growth control, and other applications of low-temperature plasmas in the production of biologically-active materials.

  10. Biomaterials in Cardiovascular Research: Applications and Clinical Implications

    Saravana Kumar Jaganathan

    2014-01-01

    Full Text Available Cardiovascular biomaterials (CB dominate the category of biomaterials based on the demand and investments in this field. This review article classifies the CB into three major classes, namely, metals, polymers, and biological materials and collates the information about the CB. Blood compatibility is one of the major criteria which limit the use of biomaterials for cardiovascular application. Several key players are associated with blood compatibility and they are discussed in this paper. To enhance the compatibility of the CB, several surface modification strategies were in use currently. Some recent applications of surface modification technology on the materials for cardiovascular devices were also discussed for better understanding. Finally, the current trend of the CB, endothelization of the cardiac implants and utilization of induced human pluripotent stem cells (ihPSCs, is also presented in this review. The field of CB is growing constantly and many new investigators and researchers are developing interest in this domain. This review will serve as a one stop arrangement to quickly grasp the basic research in the field of CB.

  11. Engineering Biomaterial Properties for Central Nervous System Applications

    Rivet, Christopher John

    Biomaterials offer unique properties that are intrinsic to the chemistry of the material itself or occur as a result of the fabrication process; iron oxide nanoparticles are superparamagnetic, which enables controlled heating in the presence of an alternating magnetic field, and a hydrogel and electrospun fiber hybrid material provides minimally invasive placement of a fibrous, artificial extracellular matrix for tissue regeneration. Utilization of these unique properties towards central nervous system disease and dysfunction requires a thorough definition of the properties in concert with full biological assessment. This enables development of material-specific features to elicit unique cellular responses. Iron oxide nanoparticles are first investigated for material-dependent, cortical neuron cytotoxicity in vitro and subsequently evaluated for alternating magnetic field stimulation induced hyperthermia, emulating the clinical application for enhanced chemotherapy efficacy in glioblastoma treatment. A hydrogel and electrospun fiber hybrid material is first applied to a rat brain to evaluate biomaterial interface astrocyte accumulation as a function of hybrid material composition. The hybrid material is then utilized towards increasing functional engraftment of dopaminergic progenitor neural stem cells in a mouse model of Parkinson's disease. Taken together, these two scenarios display the role of material property characterization in development of biomaterial strategies for central nervous system repair and regeneration.

  12. [Quality of biomaterials in liquid- and tissue-biobanking].

    Herpel, Esther; Schmitt, Sabrina; Kiehntopf, Michael

    2016-03-01

    During the last years, many biobanks that collect and provide biomaterials as well as associated phenotypical data have been established on national and international levels. However, due to the heterogeneity in structure and process landscape between biobanks, quality issues arise, which might affect equivalence of sample quality and thus usability of biomaterials for scientific research projects as well as interoperability of biobanks.Here, we will give an overview on the influence of biobanking procedures on sample quality and on potential quality control measures for research biobanks, mainly focusing on tissue and liquid biomaterials. General infrastructural requirements as well as the influence of preanalytical variables affecting sample quality and usability are described and opportunities and drawbacks of different quality assurance procedures are discussed. As there is increasing consensus on national and international levels that evidence-based standardization and harmonization of biobank structures and workflows are urgently needed for quality-assured biobanking, recent activities in the development and implementation of an ISO Standard for biobanks will be illustrated in the last section of this article. PMID:26753866

  13. Scattering Anisotropy Measurements in Dental Tissues and Biomaterials

    Fernandez-Oliveras, A.; Rubiño, M.; Perez, M. M.

    2012-05-01

    Understanding the behaviour of light propagation in biological materials is essential for biomedical engineering and applications, and even more so when dealing with incoming biomaterials. Many methods for determining optical parameters from biological media assume that scattered light is isotropically distributed over all angles. However, an angular dependence of light scattering may exist and affect the optical behaviour of biological media. The present work seeks to experimentally analyze the scattering anisotropy in different dental tissues (enamel and dentine) and their potential substitute biomaterials (hybrid dental-resin, nano-filled composite, and zirconia ceramic) and comparatively study them. Goniometric measurements were made for four wavelengths in the visible range, allowing a spectral characterization of the materials studied. Previously, for each material, measurements were made with two different sample thicknesses at the same wavelength, checking the behaviour of the angular scattering profile. The asymmetry of experimental phase functions was considered in the recovery of the scattering anisotropy factor. The results demonstrate that the thicker sample yielded a less forward-directed scattering profile than did the thinner sample. The biomaterials analysed show angular scattering comparable to those of the tissues that they may replace. Comparisons can be made by virtue of the low uncertainties found.

  14. Deformation analysis in biomaterials using digital speckle interferometry

    Salvador, R.; González-Peña, R.; Cibrián, R.; Buend­ía, M.; Mínguez, F.; Micó, V.; Carrión, J. A.; Esteve-Taboada, J. J.; Molina-Jiménez, T.; Simón, S.; Pérez, E.

    2007-06-01

    One of the most interesting points when evaluating the response of an implanted prosthesis is the knowledge of how biomaterials behave under a certain deforming stress. Obviously, the greater the stress on a particular moment, the higher possibility of the failure implant. But in many cases, the most important fact regarding the implant failure is due to a lesser stress that is continuously applied. Therefore it is helpful to know how biomaterials respond to this lesser stress. Digital speckle interferometry (DSPI) is suitable for this type of determination because of it is a highly sensitive and non-invasive optical technique. The aim of the presented work is determining the elasticity of biomaterials such as osseous structures and implants used to replace bones and to fix fractures between them. In particular, preliminary results were obtained applied to macerated human radius and a titanium screw used to treat the fractures of this bone. The analysis shows high correlation ratios in determining Young's modulus via DSPI technique in comparison with than that obtained by creation of the bone computer aided design (CAD) model using finite element method (FEM) in ANSYS software. The high degree of concordance between the results of both methods makes it possible to continue studying osseous samples with a fixed implant, and also other implants made of different alloys.

  15. Bio-functional nano-coatings on metallic biomaterials.

    Mahapatro, Anil

    2015-10-01

    Metals and their alloys have been widely used in all aspects of science, engineering and medicine. Metals in biomedical devices are used due to their inertness and structural functions. They are generally preferred over polymers or ceramics and are especially desirable in applications where the implants are subjected to static, dynamic or cyclic loads that require a combination of strength and ductility. In biomedicine, the choice of a specific biomaterial is governed by many factors that include biocompatibility, corrosion resistance, controlled degradability, modulus of elasticity, fatigue strength and many other application specific criterions. Nanotechnology is driving newer demands and requirements for better performance of existing materials and presents an opportunity for surface modification of metals in response to demands on the surface of metals for their biomedical applications. Self-assembled monolayers (SAMs) are nanosized coatings that present a flexible method of carrying out surface modification of biomaterials to tailor its surface properties for specific end applications. These nanocoatings can serve primary functions such as surface coverage, etch protection and anti-corrosion along with a host of other secondary chemical functions such as drug delivery and biocompatibility. We present a brief introduction to surface modification of biomaterials and their alloys followed by a detailed description of organic nanocoatings based on self-assembled monolayers and their biomedical applications including patterning techniques and biological applications of patterned SAMs. PMID:26117759

  16. Osteoinduction of calcium phosphate biomaterials in small animals

    Although osteoinduction mechanism of calcium phosphate (CP) ceramics is still unclear, several essential properties have been reported, such as chemical composition, pore size and porosity, etc. In this study, calcium phosphate powder (Ca3(PO4)2, CaP, group 1), biphasic calcium phosphate ceramic powder (BCP, group 2), and intact BCP rods (group 3) were implanted into leg muscles of mice and dorsal muscles of rabbits. One month and three months after implantation, samples were harvested for biological and histological analysis. New bone tissues were observed in 10/10 samples in group 1, 3/10 samples in group 2, and 9/10 samples in group 3 at 3rd month in mice, but not in rabbits. In vitro, human mesenchymal stem cells (hMSCs) were cultured with trace CaP and BCP powder, and osteogenic differentiation was observed at day 7. Our results suggested that chemical composition is the prerequisite in osteoinduction, and pore structure would contribute to more bone formation. - Highlights: ► Intrinsic osteoinduction of calcium phosphate biomaterials was observed implanted in muscles of mice. ► Biomaterials powder also has osteoinduction property. ► Osteogenic genes and protein could be detected by RT-PCR and Western blot in implanted biomaterials. ► Osteogenic phenomenon could be observed by electron microscopy. ► The chemical composition is the prerequisite in osteoinduction, and pore structure would contribute to more bone formation

  17. Wood Composite Adhesives

    Gomez-Bueso, Jose; Haupt, Robert

    The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

  18. Biomaterial based modulation of macrophage polarization: a review and suggested design principles

    Rukmani Sridharan

    2015-07-01

    Full Text Available Macrophages have long been known for their phagocytic capabilities and immune defence; however, their role in healing is being increasingly recognized in recent years due to their ability to polarize into pro-inflammatory and anti-inflammatory phenotypes. Historically, biomaterials were designed to be inert to minimize the host response. More recently, the emergence of tissue engineering and regenerative medicine has led to the design of biomaterials that interact with the host through tailored mechanical, chemical and temporal characteristics. Due to such advances in biomaterial functionality and an improved understanding of macrophage responses to implanted materials, it is now possible to identify biomaterial design characteristics that dictate the host response and contribute to successful tissue integration. Herein, we begin by briefly reviewing macrophage cell origin and the key cytokine/chemokine markers of macrophage polarization and then describe which responses are favorable for both replacement and regenerative biomaterials. The body of the review focuses on macrophage polarization in response to inherent cues directly provided by biomaterials and the consequent cues that result from events related to biomaterial implantation. To conclude, a section on potential design principles for both replacement and regenerative biomaterials is presented. An in depth understanding of biomaterial cues to selectively polarize macrophages may prove beneficial in the design of a new generation of ‘immuno-informed’ biomaterials that can positively interact with the immune system to dictate a favorable macrophage response following implantation.

  19. Functional assay, expression of growth factors and proteins modulating bone-arrangement in human osteoblasts seeded on an anorganic bovine bone biomaterial

    O Trubiani

    2010-07-01

    Full Text Available The basic aspects of bone tissue engineering include chemical composition and geometry of the scaffold design, because it is very important to improve not only cell attachment and growth but especially osteodifferentiation, bone tissue formation, and vascularization. Geistlich Bio-Oss® (GBO is a xenograft consisting of deproteinized, sterilized bovine bone, chemically and physically identical to the mineral phase of human bone.In this study, we investigated the growth behaviour and the ability to form focal adhesions on the substrate, using vinculin, a cytoskeletal protein, as a marker. Moreover, the expression of bone specific proteins and growth factors such as type I collagen, osteopontin, bone sialoprotein, bone morphogenetic protein-2 (BMP-2, BMP-7 and de novo synthesis of osteocalcin in normal human osteoblasts (NHOst seeded on xenogenic GBO were evaluated. Our observations suggest that after four weeks of culture in differentiation medium, the NHOst showed a high affinity for the three dimensional biomaterial; in fact, cellular proliferation, migration and colonization were clearly evident. The osteogenic differentiation process, as demonstrated by morphological, histochemical, energy dispersive X-ray microanalysis and biochemical analysis was mostly obvious in the NHOst grown on three-dimensional inorganic bovine bone biomaterial. Functional studies displayed a clear and significant response to calcitonin when the cells were differentiated. In addition, the presence of the biomaterial improved the response, suggesting that it could drive the differentiation of these cells towards a more differentiated osteogenic phenotype. These results encourage us to consider GBO an adequate biocompatible three-dimensional biomaterial, indicating its potential use for the development of tissue-engineering techniques.

  20. Coating Reduces Ice Adhesion

    Smith, Trent; Prince, Michael; DwWeese, Charles; Curtis, Leslie

    2008-01-01

    The Shuttle Ice Liberation Coating (SILC) has been developed to reduce the adhesion of ice to surfaces on the space shuttle. SILC, when coated on a surface (foam, metal, epoxy primer, polymer surfaces), will reduce the adhesion of ice by as much as 90 percent as compared to the corresponding uncoated surface. This innovation is a durable coating that can withstand several cycles of ice growth and removal without loss of anti-adhesion properties. SILC is made of a binder composed of varying weight percents of siloxane(s), ethyl alcohol, ethyl sulfate, isopropyl alcohol, and of fine-particle polytetrafluoroethylene (PTFE). The combination of these components produces a coating with significantly improved weathering characteristics over the siloxane system alone. In some cases, the coating will delay ice formation and can reduce the amount of ice formed. SILC is not an ice prevention coating, but the very high water contact angle (greater than 140 ) causes water to readily run off the surface. This coating was designed for use at temperatures near -170 F (-112 C). Ice adhesion tests performed at temperatures from -170 to 20 F (-112 to -7 C) show that SILC is a very effective ice release coating. SILC can be left as applied (opaque) or buffed off until the surface appears clear. Energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) data show that the coating is still present after buffing to transparency. This means SILC can be used to prevent ice adhesion even when coating windows or other objects, or items that require transmission of optical light. Car windshields are kept cleaner and SILC effectively mitigates rain and snow under driving conditions.

  1. Polyurethane/polylactide-based biomaterials combined with rat olfactory bulb-derived glial cells and adipose-derived mesenchymal stromal cells for neural regenerative medicine applications

    Research concerning the elaboration and application of biomaterial which may support the nerve tissue regeneration is currently one of the most promising directions. Biocompatible polymer devices are noteworthy group among the numerous types of potentially attractive biomaterials for regenerative medicine application. Polylactides and polyurethanes may be utilized for developing devices for supporting the nerve regeneration, like nerve guide conduits or bridges connecting the endings of broken nerve tracts. Moreover, the combination of these biomaterial devices with regenerative cell populations, like stem or precursor cells should significantly improve the final therapeutic effect. Therefore, the composition and structure of final device should support the proper adhesion and growth of cells destined for clinical application. In current research, the three polymer mats elaborated for connecting the broken nerve tracts, made from polylactide, polyurethane and their blend were evaluated both for physical properties and in vitro, using the olfactory-bulb glial cells and mesenchymal stem cells. The evaluation of Young's modulus, wettability and roughness of obtained materials showed the differences between analyzed samples. The analysis of cell adhesion, proliferation and morphology showed that the polyurethane–polylactide blend was the most neutral for cells in culture, while in the pure polymer samples there were significant alterations observed. Our results indicated that polyurethane–polylactide blend is an optimal composition for culturing and delivery of glial and mesenchymal stem cells. - Highlights: • Polyurethane–polylactide blends exhibit different characteristics from pure polymers. • Pure PU and PLA negatively influence on morphology of glial and mesenchymal cells. • PU/PLA blend was neutral for glial and mesenchymal cell proliferation and morphology

  2. Polyurethane/polylactide-based biomaterials combined with rat olfactory bulb-derived glial cells and adipose-derived mesenchymal stromal cells for neural regenerative medicine applications

    Grzesiak, Jakub, E-mail: grzesiak.kuba@gmail.com [Electron Microscopy Laboratory, University of Environmental and Life Sciences, Kozuchowska 5b, 51-631 Wroclaw (Poland); Marycz, Krzysztof [Electron Microscopy Laboratory, University of Environmental and Life Sciences, Kozuchowska 5b, 51-631 Wroclaw (Poland); Szarek, Dariusz [Department of Neurosurgery, Lower Silesia Specialist Hospital of T. Marciniak, Emergency Medicine Center, Traugutta 116, 50-420 Wroclaw (Poland); Bednarz, Paulina [State Higher Vocational School in Tarnów, Mickiewicza 8, 33-100 Tarnów (Poland); Laska, Jadwiga [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza 30, 30-059 Kraków (Poland)

    2015-07-01

    Research concerning the elaboration and application of biomaterial which may support the nerve tissue regeneration is currently one of the most promising directions. Biocompatible polymer devices are noteworthy group among the numerous types of potentially attractive biomaterials for regenerative medicine application. Polylactides and polyurethanes may be utilized for developing devices for supporting the nerve regeneration, like nerve guide conduits or bridges connecting the endings of broken nerve tracts. Moreover, the combination of these biomaterial devices with regenerative cell populations, like stem or precursor cells should significantly improve the final therapeutic effect. Therefore, the composition and structure of final device should support the proper adhesion and growth of cells destined for clinical application. In current research, the three polymer mats elaborated for connecting the broken nerve tracts, made from polylactide, polyurethane and their blend were evaluated both for physical properties and in vitro, using the olfactory-bulb glial cells and mesenchymal stem cells. The evaluation of Young's modulus, wettability and roughness of obtained materials showed the differences between analyzed samples. The analysis of cell adhesion, proliferation and morphology showed that the polyurethane–polylactide blend was the most neutral for cells in culture, while in the pure polymer samples there were significant alterations observed. Our results indicated that polyurethane–polylactide blend is an optimal composition for culturing and delivery of glial and mesenchymal stem cells. - Highlights: • Polyurethane–polylactide blends exhibit different characteristics from pure polymers. • Pure PU and PLA negatively influence on morphology of glial and mesenchymal cells. • PU/PLA blend was neutral for glial and mesenchymal cell proliferation and morphology.

  3. Enhancing the mechanical and biological performance of a metallic biomaterial for orthopedic applications through changes in the surface oxide layer by nanocrystalline surface modification.

    Bahl, Sumit; Shreyas, P; Trishul, M A; Suwas, Satyam; Chatterjee, Kaushik

    2015-05-01

    Nanostructured metals are a promising class of biomaterials for application in orthopedics to improve the mechanical performance and biological response for increasing the life of biomedical implants. Surface mechanical attrition treatment (SMAT) is an efficient way of engineering nanocrystalline surfaces on metal substrates. In this work, 316L stainless steel (SS), a widely used orthopedic biomaterial, was subjected to SMAT to generate a nanocrystalline surface. Surface nanocrystallization modified the nature of the oxide layer present on the surface. It increased the corrosion-fatigue strength in saline by 50%. This increase in strength is attributed to a thicker oxide layer, residual compressive stresses, high strength of the surface layer, and lower propensity for intergranular corrosion in the nanocrystalline layer. Nanocrystallization also enhanced osteoblast attachment and proliferation. Intriguingly, wettability and surface roughness, the key parameters widely acknowledged for controlling the cellular response remained unchanged after nanocrystallization. The observed cellular behavior is explained in terms of the changes in electronic properties of the semiconducting passive oxide film present on the surface of 316L SS. Nanocrystallization increased the charge carrier density of the n-type oxide film likely preventing denaturation of the adsorbed cell-adhesive proteins such as fibronectin. In addition, a net positive charge developed on the otherwise neutral oxide layer, which is known to facilitate cellular adhesion. The role of changes in the electronic properties of the oxide films on metal substrates is thus highlighted in this work. This study demonstrates the advantages of nanocrystalline surface modification by SMAT for processing metallic biomaterials used in orthopedic implants. PMID:25833718

  4. Sundew-Inspired Adhesive Hydrogels Combined with Adipose-Derived Stem Cells for Wound Healing.

    Sun, Leming; Huang, Yujian; Bian, Zehua; Petrosino, Jennifer; Fan, Zhen; Wang, Yongzhong; Park, Ki Ho; Yue, Tao; Schmidt, Michael; Galster, Scott; Ma, Jianjie; Zhu, Hua; Zhang, Mingjun

    2016-01-27

    The potential to harness the unique physical, chemical, and biological properties of the sundew (Drosera) plant's adhesive hydrogels has long intrigued researchers searching for novel wound-healing applications. However, the ability to collect sufficient quantities of the sundew plant's adhesive hydrogels is problematic and has eclipsed their therapeutic promise. Inspired by these natural hydrogels, we asked if sundew-inspired adhesive hydrogels could overcome the drawbacks associated with natural sundew hydrogels and be used in combination with stem-cell-based therapy to enhance wound-healing therapeutics. Using a bioinspired approach, we synthesized adhesive hydrogels comprised of sodium alginate, gum arabic, and calcium ions to mimic the properties of the natural sundew-derived adhesive hydrogels. We then characterized and showed that these sundew-inspired hydrogels promote wound healing through their superior adhesive strength, nanostructure, and resistance to shearing when compared to other hydrogels in vitro. In vivo, sundew-inspired hydrogels promoted a "suturing" effect to wound sites, which was demonstrated by enhanced wound closure following topical application of the hydrogels. In combination with mouse adipose-derived stem cells (ADSCs) and compared to other therapeutic biomaterials, the sundew-inspired hydrogels demonstrated superior wound-healing capabilities. Collectively, our studies show that sundew-inspired hydrogels contain ideal properties that promote wound healing and suggest that sundew-inspired-ADSCs combination therapy is an efficacious approach for treating wounds without eliciting noticeable toxicity or inflammation. PMID:26731614

  5. Tuning the material-cytoskeleton crosstalk via nanoconfinement of focal adhesions.

    Natale, Carlo F; Ventre, Maurizio; Netti, Paolo A

    2014-03-01

    Material features proved to exert a potent influence on cell behaviour in terms of adhesion, migration and differentiation. In particular, biophysical and biochemical signals on material surfaces are able to affect focal adhesion distribution and cytoskeletal assemblies, which are known to regulate signalling pathways that ultimately influence cell fate and functions. However, a general, unifying model that correlates cytoskeletal-generated forces with genetic events has yet to be developed. Therefore, it is crucial to gain a better insight into the material-cytoskeleton crosstalk in order to design and fabricate biomaterials able to govern cell fate more accurately. In this work, we demonstrate that confining focal adhesion distribution and growth dramatically alters the cytoskeleton's structures and dynamics, which in turn dictate cellular and nuclear shape and polarization. MC3T3 preosteoblasts were cultivated on nanograted polydimethylsiloxane substrates and a thorough quantification - in static and dynamic modes - of the morphological and structural features of focal adhesions and cytoskeleton was performed. Nanoengineered surfaces provided well-defined zones for focal adhesions to form and grow. Unique cytoskeletal structures spontaneously assembled when focal adhesions were confined and, in fact, they proved to be very effective in deforming the nuclei. The results here presented provide elements to engineer surfaces apt to guide and control cell behaviour through the material-cytoskeleton-nucleus axis. PMID:24388800

  6. Tuning cell adhesion on polymeric and nanocomposite surfaces: Role of topography versus superhydrophobicity.

    Zangi, Sepideh; Hejazi, Iman; Seyfi, Javad; Hejazi, Ehsan; Khonakdar, Hossein Ali; Davachi, Seyed Mohammad

    2016-06-01

    Development of surface modification procedures which allow tuning the cell adhesion on the surface of biomaterials and devices is of great importance. In this study, the effects of different topographies and wettabilities on cell adhesion behavior of polymeric surfaces are investigated. To this end, an improved phase separation method was proposed to impart various wettabilities (hydrophobic and superhydrophobic) on polypropylene surfaces. Surface morphologies and compositions were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Cell culture was conducted to evaluate the adhesion of 4T1 mouse mammary tumor cells. It was found that processing conditions such as drying temperature is highly influential in cell adhesion behavior due to the formation of an utterly different surface topography. It was concluded that surface topography plays a more significant role in cell adhesion behavior rather than superhydrophobicity since the nano-scale topography highly inhibited the cell adhesion as compared to the micro-scale topography. Such cell repellent behavior could be very useful in many biomedical devices such as those in drug delivery and blood contacting applications as well as biosensors. PMID:27040256

  7. Freezing-induced deformation of biomaterials in cryomedicine

    Ozcelikkale, Altug

    Cryomedicine utilizes low temperature treatments of biological proteins, cells and tissues for cryopreservation, materials processing and cryotherapy. Lack of proper understanding of cryodamage that occurs during these applications remains to be the primary bottleneck for development of successful tissue cryopreservation and cryosurgery procedures. An engineering approach based on a view of biological systems as functional biomaterials can help identify, predict and control the primary cryodamage mechanisms by developing an understanding of underlying freezing-induced biophysical processes. In particular, freezing constitutes the main structural/mechanical origin of cryodamage and results in significant deformation of biomaterials at multiple length scales. Understanding of these freezing-induced deformation processes and their effects on post-thaw biomaterial functionality is currently lacking but will be critical to engineer improved cryomedicine procedures. This dissertation addresses this problem by presenting three separate but related studies of freezing-induced deformation at multiple length scales including nanometer-scale protein fibrils, single cells and whole tissues. A combination of rigorous experimentation and computational modeling is used to characterize post-thaw biomaterial structure and properties, predict biomaterial behavior and assess its post-thaw biological functionality. Firstly, freezing-induced damage on hierarchical extracellular matrix structure of collagen is investigated at molecular, fibril and matrix levels. Results indicate to a specific kind of fibril damage due to freezing-induced expansion of intrafibrillar fluid. This is followed by a study of freezing-induced cell and tissue deformation coupled to osmotically driven cellular water transport. Computational and semi empirical modeling of these processes indicate that intracellular deformation of the cell during freezing is heterogeneous and can interfere with cellular water

  8. Interactions between biomaterials and the sclera: Implications on myopia progression

    Su, James

    Myopia prevalence has steadily climbed worldwide in recent decades with the most dramatic impact in East Asian countries. Treatments such as eyeglasses, contact lenses, and laser surgery for the refractive error are widely available, but none cures the underlying cause. In progressive high myopia, invasive surgical procedures using a scleral buckle for mechanical support are performed since the patient is at risk of becoming blind. The treatment outcome is highly dependent on the surgeon's skills and the patient's myopia progression rate, with limited choices in buckling materials. This dissertation, in four main studies, represents efforts made to control high myopia progression through the exploration and development of biomaterials that influence scleral growth. First, mRNA expression levels of the chick scleral matrix metalloproteinases, tissue-inhibitor of matrix metalloproteinases, and transforming growth factor-beta 2 were assessed for temporal and defocus power effects. The first study elucidated the roles that these factors play in scleral growth regulation and suggested potential motifs that can be incorporated in future biomaterials design. Second, poly(vinyl-pyrrolidone) as injectable gels and poly(2-hydroxyethyl methacrylate) as solid strips were implanted in chicks to demonstrate the concept of posterior pole scleral reinforcements. This second study found that placing appropriate biomaterials at the posterior pole of the eye could directly influence scleral remodeling by interacting with the host cells. Both studies advanced the idea that scleral tissue remodeling could be potentially controlled by well-designed biomaterials. These findings led to the exploration of biomimetic hydrogels comprising enzymatically-degradable semi-interpenetrating polymer networks (edsIPNs) to determine their biocompatibility and effects on the chick posterior eye wall. This third study demonstrated the feasibility of stimulating scleral growth by applying biomimetic

  9. The role of biomaterial properties in peri-implant neovascularization

    Raines, Andrew Lawrence

    An understanding of the interactions between orthopaedic and dental implant surfaces with the surrounding host tissue is critical in the design of next generation implants to improve osseointegration and clinical success rates. Critical to the process of osseointegration is the rapid establishment of a patent neovasculature in the peri-implant space to allow for the delivery of oxygen, nutrients, and progenitor cells. The central aim of this thesis is to understand how biomaterials regulate cellular and host tissue response to elicit a pro-angiogenic microenvironment at the implant/tissue interface. To address this question, the studies performed in this thesis aim to (1) determine whether biomaterial surface properties can modulate the production and secretion of pro-angiogenic growth factors by cells, (2) determine the role of integrin and VEGF-A signaling in the angiogenic response of cells to implant surface features, and (3) to determine whether neovascularization in response to an implanted biomaterial can be modulated in vivo. The results demonstrate that biomaterial surface microtopography and surface energy can increase the production of pro-angiogenic growth factors by osteoblasts and that these growth factors stimulate the differentiation of endothelial cells in a paracrine manner and the results suggest that signaling through specific integrin receptors affects the production of angiogenic growth factors by osteoblast-like cells. Further, using a novel in vivo model, the results demonstrate that a combination of a rough surface microtopography and high surface energy can improve bone-to-implant contact and neovascularization. The results of these studies also suggest that VEGF-A produced by osteoblast-like cells has both an autocrine and paracrine effect. VEGF-A silenced cells exhibited reduced production of both pro-angiogenic and osteogenic growth factors in response to surface microtopgraphy and surface energy, and conditioned media from VEGF

  10. The physical properties of two biomaterials and their effects in repairing abdominal wall defects in rat

    Guan-yu WANG

    2011-05-01

    Full Text Available Objective To compare the physical properties of porcine small intestinal submucosa(P-SIS and porcine pericardium(P-PC and their effects in repairing abdominal wall defects in rat,in order to look for a more suitable biomaterial for repairing abdominal wall defect.Methods P-SIS and P-PC were harvested from 5 BA-MA Mini-Pigs(around 50kg within 4h of sacrifice.P-SIS was prepared with Abraham’s method,and P-PC was prepared with Trypsin+Triton X-100 method.The strength against butting force,strength against expansion force,water vapor permeability,thickness and tensile strength were then respectively tested.48 male SD rats weighed from 290g to 310g were randomly divided into 2 groups(24 each.Abdominal wall defects(3cm×2cm were created by surgery and repaired with P-SIS or P-PC respectively.Animals were sacrificed at the 2nd,4th,6th and 8th week after operation.The tensile strength and expansion rate of implanted materials and the development of adhesions were measured and observed.Results The thickness of P-PC(0.17±0.01mm was about 3 times that of P-SIS(0.05±0.01mm;The strength against expansion force of P-PC(52.10±6.50 Psi was about 8 times that of P-SIS(6.70±0.45 Psi;The strength against butting force of P-PC(166.86±16.15N was about 6 times of P-SIS(25.94±2.92N;The tensile strength of P-PC(31.80±6.16MPa was about 3 times that of P-SIS(11.81±2.50MPa.The water vapor permeability of P-SIS [4772.82±279.64 g/(m2·d] was about 1.5 times that of P-PC [3108.28±233.69g/(m2·d].The tensile strength of both materials declined significantly after implantation,recovered slowly from the 4th week on,and returned to normal after 6 weeks.The area of P-SIS implant gradually shrank after implantation;the implanted area of P-PC was 5.05±0.27cm2 at the 2nd week,9.99±0.89cm2 at the 4th week,6.83±0.19cm2 at the 6th week,and 10.63±0.91cm2 at the 8th week.The implanted area of P-PC was larger than that of P-SIS 4 weeks after implantation(P < 0.05.The

  11. Pathogenesis of postoperative adhesion formation

    Hellebrekers, B.W.J.; Kooistra, T.

    2011-01-01

    Background: Current views on the pathogenesis of adhesion formation are based on the "classical concept of adhesion formation", namely that a reduction in peritoneal fibrinolytic activity following peritoneal trauma is of key importance in adhesion development. Methods: A non-systematic literature s

  12. In situ forming, metal-adhesive heparin hydrogel surfaces for blood-compatible coating.

    Joung, Yoon Ki; You, Seung Soo; Park, Kyung Min; Go, Dong Hyun; Park, Ki Dong

    2012-11-01

    Durable and blood-compatible coating of metallic biomaterials remains a major issue in biomedical fields despite its long history of development. In this study, in situ forming, metal-adhesive heparin hydrogels were developed to coat metallic substrates to enhance blood compatibility. The hydrogels are composed of metal-adhesive and enzyme-reactive amphiphilic block copolymer (Tetronic-tyramine/dopamine; TTD) and enzyme-reactive heparin derivatives (heparin-tyramine or heparin-polyethylene glycol-tyramine), which are cross-linkable in situ via an enzyme reaction. The combinations of heparin and Tetronic formed hydrogels with relatively high mechanical strengths of 300-5000 Pa within several tens of seconds; this was also confirmed by observing a dried porous structure as coated on a metal surface. The introduction of dopamine to the hydrogel network enhanced the durability of the hydrogel layers coated on metal, such that more than 60% heparin remained for 7 days. Compared to bare metal surfaces, hydrogel-coated metal surfaces exhibited significantly enhanced blood compatibility. Reduced fibrinogen adsorption and platelet adhesion showed that blood compatibility was 3-5-fold-enhanced on coated hydrogel layers than on the bare metal surface. In conclusion, hydrogels containing heparin and dopamine prepared by enzyme reaction have the potential to be an alternative coating method for enhancing blood compatibility of metallic biomaterials. PMID:22100384

  13. Initial Bacterial Adhesion on Different Yttria-Stabilized Tetragonal Zirconia Implant Surfaces in Vitro

    Lamprini Karygianni

    2013-12-01

    Full Text Available Bacterial adhesion to implant biomaterials constitutes a virulence factor leading to biofilm formation, infection and treatment failure. The aim of this study was to examine the initial bacterial adhesion on different implant materials in vitro. Four implant biomaterials were incubated with Enterococcus faecalis, Staphylococcus aureus and Candida albicans for 2 h: 3 mol % yttria-stabilized tetragonal zirconia polycrystal surface (B1a, B1a with zirconium oxide (ZrO2 coating (B2a, B1a with zirconia-based composite coating (B1b and B1a with zirconia-based composite and ZrO2 coatings (B2b. Bovine enamel slabs (BES served as control. The adherent microorganisms were quantified and visualized using scanning electron microscopy (SEM; DAPI and live/dead staining. The lowest bacterial count of E. faecalis was detected on BES and the highest on B1a. The fewest vital C. albicans strains (42.22% were detected on B2a surfaces, while most E. faecalis and S. aureus strains (approximately 80% were vital overall. Compared to BES; coated and uncoated zirconia substrata exhibited no anti-adhesive properties. Further improvement of the material surface characteristics is essential.

  14. Design and validation of a dynamic flow model simulating encrustation of biomaterials in the urinary tract.

    Gorman, Sean P; Garvin, Clare P; Quigley, Fergus; Jones, David S

    2003-04-01

    A number of models exist for assessing encrustation on biomaterials employed as devices in the urinary tract. However, static urine models are suitable only for assessment of biomaterials residing in the bladder and the dynamic models available suffer from a number of disadvantages, notably their complexity and limitation to short-term assessment. The dynamic model described herein is a relatively simple design incorporating the ability to assess a large number of biomaterials in replicate fashion and over long periods of time. The biomaterials tested in the dynamic model conform to the urethral catheter and ureteral stent devices that experience urine flow within the urinary tract. The model was initially validated using Percuflex as a test biomaterial. The mass of calcium and magnesium, representing hydroxyapatite and struvite encrustation, respectively, on Percuflex was detected by atomic absorption spectrometry. No significant differences in encrustation levels were detected either between vessels or between biomaterial positions on any mandrel within the vessels, indicating the suitability of the dynamic model for reproducible determination of biomaterial encrustation. The dynamic model was then used to compare the encrustation of biomaterials commonly employed in urinary-tract devices, namely polyurethane, Percuflex and silicone. Calcium and magnesium levels on polyurethane and Percuflex were shown to be statistically similar, whereas silicone exhibited significantly reduced encrustation. When, subsequently, comparisons were made of biomaterial encrustation between the dynamic model and a static model, calcium and magnesium levels arising from the latter model were significantly higher on each of the biomaterials. However, the same rank order of encrustation resistance was observed for the biomaterials in both models, with silicone performing better than polyurethane or Percuflex. The prediction of in-vivo performance based on in-vitro models of encrustation

  15. Can cells and biomaterials in therapeutic medicine be shielded off from innate immune recognition?

    Nilsson, Bo; Korsgren, Olle; Lambris, John D.; Ekdahl, Kristina Nilsson

    2010-01-01

    Biomaterials (e.g. polymers, metals, or ceramics), cell, and cell cluster (e.g. pancreatic islets) transplantation are beginning to offer novel treatment modalities for some otherwise intractable diseases. The innate immune system is involved in incompatibility reactions that occur when biomaterials or cells are introduced into the blood circulation. In particular the complement, coagulation, and contact systems are involved in the recognition of biomaterials and cells, eliciting activation o...

  16. The challenge to improve the response of biomaterials to the physiological environment

    Peppas, Nicholas A.; Clegg, John R.

    2016-01-01

    New applications of biomaterials often require advanced structures containing synthetic and natural components that are tuned to provide properties unique to a specific application. We discuss how structural characteristics of biomaterials, especially hydrophilic ones, can be used in conjunction with non-ideal thermodynamics to develop advanced medical systems. We show a number of examples of biocompatible, intelligent biomaterials that can be used for organ replacement, biosensors, precise d...

  17. Frontiers in biomaterials the design, synthetic strategies and biocompatibility of polymer scaffolds for biomedical application

    Cao, Shunsheng

    2014-01-01

    Frontiers in Biomaterials: The Design, Synthetic Strategies and Biocompatibility of Polymer Scaffolds for Biomedical Application, Volume 1" highlights the importance of biomaterials and their interaction with biological system. The need for the development of biomaterials as scaffold for tissue regeneration is driven by the increasing demands for materials that mimic functions of extracellular matrices of body tissues.This ebook covers the latest challenges on the biocompatibility of scaffold overtime after implantation and discusses the requirement of innovative technologies and strategies f

  18. Management of adhesive capsulitis

    Stupay KL

    2015-08-01

    Full Text Available Kristen L Stupay,1 Andrew S Neviaser2 1Tulane University School of Medicine, New Orleans, LA, USA; 2George Washington University Medical Faculty Associates, Washington, DC, USA Abstract: Adhesive capsulitis of the shoulder is a condition of capsular contracture that reduces both active and passive glenohumeral motion. The cause of adhesive capsulitis is not known but it is strongly associated with endocrine abnormalities such as diabetes. Diverse terminology and the absence of definitive criteria for diagnosis make evaluating treatment modalities difficult. Many treatment methods have been reported, most with some success, but few have been proved to alter the natural course of this disease. Most afflicted patients will achieve acceptable shoulder function without surgery. Those who remain debilitated after 8–12 months are reasonable candidates for invasive treatments. Here, the various treatment methods and the data to support their use are reviewed. Keywords: frozen shoulder, stiff shoulder, periarthritis, painful shoulder 

  19. Syndecans and cell adhesion

    Couchman, J R; Chen, L; Woods, A

    2001-01-01

    Now that transmembrane signaling through primary cell-matrix receptors, integrins, is being elucidated, attention is turning to how integrin-ligand interactions can be modulated. Syndecans are transmembrane proteoglycans implicated as coreceptors in a variety of physiological processes, including...... cell adhesion, migration, response to growth factors, development, and tumorigenesis. This review will describe this family of proteoglycans in terms of their structures and functions and their signaling in conjunction with integrins, and indicate areas for future research....

  20. Ceramic microstructure and adhesion

    Buckley, D. H.

    1985-01-01

    When a ceramic is brought into contact with a ceramic, a polymer, or a metal, strong bond forces can develop between the materials. The bonding forces will depend upon the state of the surfaces, cleanliness and the fundamental properties of the two solids, both surface and bulk. Adhesion between a ceramic and another solid are discussed from a theoretical consideration of the nature of the surfaces and experimentally by relating bond forces to interface resulting from solid state contact. Surface properties of ceramics correlated with adhesion include, orientation, reconstruction and diffusion as well as the chemistry of the surface specie. Where a ceramic is in contact with a metal their interactive chemistry and bond strength is considered. Bulk properties examined include elastic and plastic behavior in the surficial regions, cohesive binding energies, crystal structures and crystallographic orientation. Materials examined with respect to interfacial adhesive interactions include silicon carbide, nickel zinc ferrite, manganese zinc ferrite, and aluminum oxide. The surfaces of the contacting solids are studied both in the atomic or molecularly clean state and in the presence of selected surface contaminants.

  1. Designing a binding interface for control of cancer cell adhesion via 3D topography and metabolic oligosaccharide engineering.

    Du, Jian; Che, Pao-Lin; Wang, Zhi-Yun; Aich, Udayanath; Yarema, Kevin J

    2011-08-01

    This study combines metabolic oligosaccharide engineering (MOE), a technology where the glycocalyx of living cells is endowed with chemical features not normally found in sugars, with custom-designed three-dimensional biomaterial substrates to enhance the adhesion of cancer cells and control their morphology and gene expression. Specifically, Ac(5)ManNTGc, a thiol-bearing analog of N-acetyl-d-mannosamine (ManNAc) was used to introduce thiolated sialic acids into the glycocalyx of human Jurkat T-lymphoma derived cells. In parallel 2D films and 3D electrospun nanofibrous scaffolds were prepared from polyethersulfone (PES) and (as controls) left unmodified or aminated. Alternately, the materials were malemided or gold-coated to provide bio-orthogonal binding partners for the thiol groups newly expressed on the cell surface. Cell attachment was modulated by both the topography of the substrate surface and by the chemical compatibility of the binding interface between the cell and the substrate; a substantial increase in binding for normally non-adhesive Jurkat line for 3D scaffold compared to 2D surfaces with an added degree of adhesion resulting from chemoselective binding to malemidede-derivatived or gold-coated surfaces. In addition, the morphology of the cells attached to the 3D scaffolds via MOE-mediated adhesion was dramatically altered and the expression of genes involved in cell adhesion changed in a time-dependent manner. This study showed that cell adhesion could be enhanced, gene expression modulated, and cell fate controlled by introducing the 3D topograhical cues into the growth substrate and by creating a glycoengineered binding interface where the chemistry of both the cell surface and biomaterials scaffold was controlled to facilitate a new mode of carbohydrate-mediated adhesion. PMID:21549424

  2. Characterization of different biomaterials for biomonitoring the atmospheric pollution

    Instrumental Neutron Activation Analysis coupled with the Inductively Coupled Argon Plasma-Atomic Emission Spectroscopy, has been used to evaluate non destructively 25 minor and trace elements in different vegetal materials to be considered as biomaterials useful for atmospheric aerosol sampling. For quantitative evaluations, some reference materials prepared by an Inter-Institutes Committee (CII) and analyzed in an intercomparison campaign have been used. Strong attention has been devoted to the quantification of uncommon elements, important to establish the sensitivity of the employed method and the homogeneity of the sampling. (author)

  3. Novel biomaterials decontamination of toxic metals from wastewater

    Srivastava, Shalini

    2010-01-01

    Current research revolves around trends to bring technology into harmony with the natural environment and in order to protect the ecosystem. Bioremediation involves processes which reduce the overall treatment costs by using agricultural residues. Regeneration of the biosorbent further increases the cost effectiveness of the process, thus warranting its future success in solving water quality problems. Special emphasis is paid to chemical modifications resulting in tailored novel biomaterials which improve its sorption efficiency and environmental stability. In this way it can be used commerci

  4. USE OF ATOMIC LAYER DEPOSITION OF FUNCTIONALIZATION OF NANOPOROUS BIOMATERIALS

    Brigmon, R.; Narayan, R.; Adiga, S.; Pellin, M.; Curtiss, L.; Stafslien, S.; Chisholm, B.; Monteiro-Riviere, N.; Elam, J.

    2010-02-08

    Due to its chemical stability, uniform pore size, and high pore density, nanoporous alumina is being investigated for use in biosensing, drug delivery, hemodialysis, and other medical applications. In recent work, we have examined the use of atomic layer deposition for coating the surfaces of nanoporous alumina membranes. Zinc oxide coatings were deposited on nanoporous alumina membranes using atomic layer deposition. The zinc oxide-coated nanoporous alumina membranes demonstrated antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. These results suggest that atomic layer deposition is an attractive technique for modifying the surfaces of nanoporous alumina membranes and other nanostructured biomaterials.

  5. Dosimetry by stimulated exoelectronic emission of apatites and dental biomaterials

    This work is a contribution to the study of stimulated exoelectronic emission, the goal of which is the development of a dosimetry available in case of accidental irradiation. The first part is devoted to a review of the various theoretical models suggested by several authors on the exoemission phenomenon, and to the description of the experimental set up: counter and detector electronic circuits. The second part gives the experimental results obtained with the different products studied: fluorapatite, hydroxyapatite (considered to be the major constituent of bones and teeth), tricalcic phosphate and dental biomaterials: porcelain and some canal obturation substances

  6. Bacterial Adhesion Forces with Substratum Surfaces and the Susceptibility of Biofilms to Antibiotics

    Muszanska, Agnieszka K.; Nejadnik, M. Reza; Chen, Yun; van den Heuvel, Edwin R; Busscher, Henk J.; van der Mei, Henny C; Norde, Willem

    2012-01-01

    Biofilms causing biomaterial-associated infection resist antibiotic treatment and usually necessitate the replacement of infected implants. Here we relate bacterial adhesion forces and the antibiotic susceptibility of biofilms on uncoated and polymer brush-coated silicone rubber. Nine strains of Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa adhered more weakly to brush-coated silicone rubber (−0.05 ± 0.03 to −0.51 ± 0.62 nN) than to uncoated silicone rubber (−1...

  7. Characterization of adhesively bonded joints using bulk adhesive properties

    Kon, Haruhiko

    1991-01-01

    Though using bulk adhesive properties to predict adhesively bonded joint response has yet to be proven infallible, based upon the success of previous works, this effort attempts to shed some light on the stresses present in a typical automotive bonded joint. Adhesive material properties obtained in previous works were used in a finite element analysis of a simulated automotive joint to predict the stresses in that joint. The automotive joint analyzed was a simplified repr...

  8. Studying the glial cell response to biomaterials and surface topography for improving the neural electrode interface

    Ereifej, Evon S.

    Neural electrode devices hold great promise to help people with the restoration of lost functions, however, research is lacking in the biomaterial design of a stable, long-term device. Current devices lack long term functionality, most have been found unable to record neural activity within weeks after implantation due to the development of glial scar tissue (Polikov et al., 2006; Zhong and Bellamkonda, 2008). The long-term effect of chronically implanted electrodes is the formation of a glial scar made up of reactive astrocytes and the matrix proteins they generate (Polikov et al., 2005; Seil and Webster, 2008). Scarring is initiated when a device is inserted into brain tissue and is associated with an inflammatory response. Activated astrocytes are hypertrophic, hyperplastic, have an upregulation of intermediate filaments GFAP and vimentin expression, and filament formation (Buffo et al., 2010; Gervasi et al., 2008). Current approaches towards inhibiting the initiation of glial scarring range from altering the geometry, roughness, size, shape and materials of the device (Grill et al., 2009; Kotov et al., 2009; Kotzar et al., 2002; Szarowski et al., 2003). Literature has shown that surface topography modifications can alter cell alignment, adhesion, proliferation, migration, and gene expression (Agnew et al., 1983; Cogan et al., 2005; Cogan et al., 2006; Merrill et al., 2005). Thus, the goals of the presented work are to study the cellular response to biomaterials used in neural electrode fabrication and assess surface topography effects on minimizing astrogliosis. Initially, to examine astrocyte response to various materials used in neural electrode fabrication, astrocytes were cultured on platinum, silicon, PMMA, and SU-8 surfaces, with polystyrene as the control surface. Cell proliferation, viability, morphology and gene expression was measured for seven days in vitro. Results determined the cellular characteristics, reactions and growth rates of astrocytes

  9. The effect of terminal sterilization on structural and biophysical properties of a decellularized collagen-based scaffold; implications for stem cell adhesion.

    Matuska, Andrea M; McFetridge, Peter S

    2015-02-01

    Terminal sterilization induces physical and chemical changes in the extracellular matrix (ECM) of ex vivo-derived biomaterials due to their aggressive mechanism of action. Prior studies have focused on how sterilization affects the mechanical integrity of tissue-based biomaterials but have rarely characterized effects on early cellular interaction, which is indicative of the biological response. Using a model fibrocartilage disc scaffold, these investigations compare the effect of three common sterilization methods [peracetic acid (PAA), gamma irradiation (GI), and ethylene oxide (EtO)] on a range of material properties and characterized early cellular interactions. GI and EtO produced unfavorable structural damage that contributed to inferior cell adhesion. Conversely, exposure to PAA resulted in limited structural alterations while inducing chemical modifications that favored cell attachment. Results suggest that the sterilization approach can be selected to modulate biomaterial properties to favor cellular adhesion and has relevance in tissue engineering and regenerative medicine applications. Furthermore, the study of cellular interactions with modified biomaterials in vitro provides information of how materials may react in subsequent clinical applications. PMID:24895116

  10. Synthesis and characterization of zirconium-doped calcium phosphate biomaterial

    A new synthesis route for the production of calcium phosphate biomaterial was developed by using organic di-(2-ethylhexyl) phosphoric acid (DEHPA) mixed with calcium hydroxide slurry. Unlike the conventional involving chemical precipitation process this new method involves a sol-gel process. Another advantage of this method is the starting material DEHPA can form strong bonding with many elements including zirconium and rare earths. This makes it suitable to be used as drug delivery material especially those involving bone related disease. It also improves the biomaterial strength with the presence of zirconium oxide phase. From XRD analysis, the result shows the present of HA, α-TCP and β-TCP. The addition of different rare elements on to the calcium phosphate will varies the amount of these three phases. SEM analysis was also performed to study the morphology of the calcium phosphate material. The presence of the rare earths on to the calcium phosphate was established by using the EDS technique. (Author)

  11. PIXE study of the kinetics of biomaterials ossification

    Weber, G.; Robaye, G.; Braye, F.; Oudadesse, H.; Irigaray, J. L.

    1994-05-01

    Biomaterials are frequently implanted in bones. This implantation is followed by a phenomenon of ossification. The purpose of this work was to study the time evolution of the gradient of characteristic atomic element's concentrations in the bone, the implant and the bone-implant interface. We have studied two types of neutral biomaterials: pure synthetic hydroxyapatite and porite's asteroid coral. The animal implantations have been made on sheep of the same age and sex having received the same basic diet. The implantations have been made in the cortical femur. On both sides of the implant, at the same distance, two screws were placed to allow further determination of the position of the implant. The PIXE method is particularly suitable here because of the possibility to analyze directly the samples without any preparation and to choose easily the dimensions of beam used for the gradient study. The X-rays have been detected with an ultra LEGe instead of the usual Si(Li) device to avoid the Si escape peak associated with the K α X-ray of calcium, the major constituent of bone. This peak is particularly disturbing here because its energy corresponds to the K α line of phosphorus, an important constituent of bone. The results of these determinations are presented and discussed.

  12. Scattering and Absorption Properties of Biomaterials for Dental Restorative Applications

    Fernandez-Oliveras, A.; Rubiño, M.; Pérez, M. M.

    2013-08-01

    The physical understanding of the optical properties of dental biomaterials is mandatory for their final success in restorative applications.Light propagation in biological media is characterized by the absorption coefficient, the scattering coefficient, the scattering phase function,the refractive index, and the surface conditions (roughness). We have employed the inverse adding-doubling (IAD) method to combine transmittance and reflectance measurements performed using an integrating-sphere setup with the results of the previous scattering-anisotropygoniometric measurements. This has led to the determination of the absorption and the scattering coefficients. The aim was to optically characterize two different dental-resin composites (nanocomposite and hybrid) and one type of zirconia ceramic, and comparatively study them. The experimental procedure was conducted under repeatability conditions of measurement in order to determine the uncertainty associated to the optical properties of the biomaterials. Spectral variations of the refraction index and the scattering anisotropy factor were also considered. The whole experimental procedure fulfilled all the necessary requirements to provide optical-property values with lower associated uncertainties. The effective transport coefficient presented a similar spectral behavior for the two composites but completely different for the zirconia ceramic. The results demonstrated that the scattering anisotropy exerted a clearly distinct impact on the optical properties of the zirconia ceramic compared with those of the dental-resin composites.

  13. Silk as an innovative biomaterial for cancer therapy.

    Jastrzebska, Katarzyna; Kucharczyk, Kamil; Florczak, Anna; Dondajewska, Ewelina; Mackiewicz, Andrzej; Dams-Kozlowska, Hanna

    2015-01-01

    Silk has been used for centuries in the textile industry and as surgical sutures. In addition to its unique mechanical properties, silk possesses other properties, such as biocompatibility, biodegradability and ability to self-assemble, which make it an interesting material for biomedical applications. Although silk forms only fibers in nature, synthetic techniques can be used to control the processing of silk into different morphologies, such as scaffolds, films, hydrogels, microcapsules, and micro- and nanospheres. Moreover, the biotechnological production of silk proteins broadens the potential applications of silk. Synthetic silk genes have been designed. Genetic engineering enables modification of silk properties or the construction of a hybrid silk. Bioengineered hybrid silks consist of a silk sequence that self-assembles into the desired morphological structure and the sequence of a polypeptide that confers a function to the silk biomaterial. The functional domains can comprise binding sites for receptors, enzymes, drugs, metals or sugars, among others. Here, we review the current status of potential applications of silk biomaterials in the field of oncology with a focus on the generation of implantable, injectable and targeted drug delivery systems and the three-dimensional cancer models based on silk scaffolds for cancer research. However, the systems described could be applied in many biomedical fields. PMID:25859397

  14. Cleaning of biomaterial surfaces: protein removal by different solvents.

    Kratz, Fabian; Grass, Simone; Umanskaya, Natalia; Scheibe, Christian; Müller-Renno, Christine; Davoudi, Neda; Hannig, Matthias; Ziegler, Christiane

    2015-04-01

    The removal of biofilms or protein films from biomaterials is still a challenging task. In particular, for research investigations on real (applied) surfaces the reuse of samples is of high importance, because reuse allows the comparison of the same sample in different experiments. The aim of the present study was to evaluate the cleaning efficiency of different solvents (SDS, water, acetone, isopropanol, RIPA-buffer and Tween-20) on five different biomaterials (titanium, gold, PMMA (no acetone used), ceramic, and PTFE) with different wettability which were covered by layers of two different adsorbed proteins (BSA and lysozyme). The presence of a protein film after adsorption was confirmed by transmission electron microscopy (TEM). After treatment of the surfaces with the different solvents, the residual proteins on the surface were determined by BCA-assay (bicinchoninic acid assay). Data of the present study indicate that SDS is an effective solvent, but for several protein-substrate combinations it does not show the cleaning efficiency often mentioned in literature. RIPA-buffer and Tween-20 were more effective. They showed very low residual protein amounts after cleaning on all examined material surfaces and for both proteins, however, with small differences for the respective substrate-protein combinations. RIPA-buffer in combination with ultrasonication completely removed the protein layer as confirmed by TEM. PMID:25725311

  15. Insights into the Alteration of Osteoblast Mechanical Properties upon Adhesion on Chitosan

    Antonia G. Moutzouri

    2014-01-01

    Full Text Available Cell adhesion on substrates is accompanied by significant changes in shape and cytoskeleton organization, which affect subsequent cellular and tissue responses, determining the long-term success of an implant. Alterations in osteoblast stiffness upon adhesion on orthopaedic implants with different surface chemical composition and topography are, thus, of central interest in the field of bone implant research. This work aimed to study the mechanical response of osteoblasts upon adhesion on chitosan-coated glass surfaces and to investigate possible correlations with the level of adhesion, spreading, and cytoskeleton reorganization. Using the micropipette aspiration technique, the osteoblast elastic modulus was found higher on chitosan-coated than on uncoated control substrates, and it was found to increase in the course of spreading for both substrates. The cell-surface contact area was measured throughout several time points of adhesion to quantify cell spreading kinetics. Significant differences were found between chitosan and control surfaces regarding the response of cell spreading, while both groups displayed a sigmoidal kinetical behavior with an initially elevated spreading rate which stabilizes in the second hour of attachment. Actin filament structural changes were confirmed after observation with confocal microscope. Biomaterial surface modification can enhance osteoblast mechanical response and induce favorable structural organization for the implant integration.

  16. Adhesive tape exfoliation

    Bohr, Jakob

    2015-01-01

    Single-crystal graphite can be cleaved by the use of an adhesive tape. This was also the initial route for obtaining graphene, a one-layer thick graphite slab. In this letter a few simple and fun considerations are presented in an attempt to shed some light on why this procedure is successful. In...... particular on the nature of the surprisingly small number of repetitive steps that are needed in order to obtain a single-layer slab. Two frameworks for exfoliation are investigated: parallel exfoliation involving repetitive simultaneous cleaving, the other, serial exfoliation, which involves the repetitive...

  17. Polyurethane adhesive ingestion.

    Fitzgerald, Kevin T; Bronstein, Alvin C

    2013-02-01

    Polyurethane adhesives are found in a large number of household products in the United States and are used for a variety of purposes. Several brands of these expanding wood glues (those containing diphenylmethane diisocyanate [MDI]) have the potential to form gastrointestinal (GI) foreign bodies if ingested. The ingested adhesive forms an expanding ball of glue in the esophagus and gastric lumen. This expansion is caused by a polymerization reaction using the heat, water, and gastric acids of the stomach. A firm mass is created that can be 4-8 times its original volume. As little as 2 oz of glue have been reported to develop gastric foreign bodies. The obstructive mass is reported to form within minutes of ingestion of the adhesive. The foreign body can lead to esophageal impaction and obstruction, airway obstruction, gastric outflow obstruction, mucosal hemorrhage, ulceration, laceration, perforation of the esophageal and gastric linings, and death. Clinical signs following ingestion include anorexia, lethargy, vomiting, tachypnea, and abdominal distention and pain, and typically develop within 12 hours. Clinical signs may depend upon the size of the mass. If left untreated, perforation and rupture of the esophagus or stomach can occur. The glue mass does not stick to the GI mucosa and is not always detectable on abdominal palpation. Radiographs are recommended to confirm the presence of the "glue-ball" foreign body, and radiographic evidence of the obstruction may be seen as early as 4-6 hours following ingestion. Emesis is contraindicated owing to the risk of aspiration of the glue into the respiratory tree or the subsequent lodging of the expanding glue mass in the esophagus. Likewise, efforts to dilute the glue and prevent the formation of the foreign body through administration of liquids, activated charcoal, or bulk-forming products to push the foreign body through the GI tract have proven ineffective. Even endoscopy performed to remove the foreign body has

  18. Syndecan proteoglycans and cell adhesion

    Woods, A; Oh, E S; Couchman, J R

    1998-01-01

    It is now becoming clear that a family of transmembrane proteoglycans, the syndecans, have important roles in cell adhesion. They participate through binding of matrix ligand to their glycosaminoglycan chains, clustering, and the induction of signaling cascades to modify the internal microfilament...... organization. Syndecans can modulate the type of adhesive responses induced by other matrix ligand-receptor interactions, such as those involving the integrins, and so contribute to the control of cell morphology, adhesion and migration....

  19. Development of Fe-based bulk metallic glasses as potential biomaterials.

    Li, Shidan; Wei, Qin; Li, Qiang; Jiang, Bingliang; Chen, You; Sun, Yanfei

    2015-01-01

    A new series of Fe80-x-yCrxMoyP13C7 (x = 10, y = 10; x = 20, y = 5; x = 2 0, y = 10, all in at.%) bulk metallic glasses (BMGs) with the maximum diameter of 6mm have been developed for biomedical implant application by the combination method of fluxing treatment and J-quenching technique. The corrosion performance of the present Fe-based BMGs is investigated in both Hank's solution (pH = 7.4) and artificial saliva solution (pH = 6.3) at 37 °C by electrochemical measurements. The result indicates that the corrosion resistance of the present Fe-based BMGs in the above two simulated body solutions is much better than that of biomedical 316 L stainless steel (316 L SS), and approaching that of Ti6Al4V biomedical alloy (TC4). The concentrations of Fe, Ni and Cr ions released into the Hank's solution and artificial saliva solution from the present Fe-based BMGs after potentiodynamic polarization are significant lower than that released from 316 L SS. The biocompatibility of the present Fe-based BMGs is evaluated through the in vitro test of NIH3T3 cells culture in the present Fe-based BMG extraction media for 1, 3 and 5 days. The result indicates that the present Fe-based BMGs exhibit no cytotoxicity to NIH3T3 cells. And the test result of the cell adhesion and growth on the surface of the samples indicates that the present Fe-based BMGs exhibit the better cell viability compared with 316 L SS and TC4 biomedical alloys. The present Fe-based BMGs, especially Fe55Cr20Mo5P13C7 BMG, exhibit good glass formation ability, the high corrosion resistance and excellent biocompatibility, suggesting their promising potential as biomaterials. PMID:25953563

  20. Preparation of biomaterials on the basis of a water-soluble cellulose acetate

    Akmalova, G. Yu.; Gulyamova, N. S.; Zainutdinov, U. N.; Rakhmanberdiev, G. R.; Negmatova, K. S.; Negmatova, M. I.

    2012-07-01

    Biomaterials were obtained on the basis of water-soluble cellulose acetate and diterpenoids group of plants Lagohulusa intoxicating having hemostatic properties. It is established that these biomaterials on the basis of water-soluble cellulose acetate and lagohilina (or lagohirzina) had increased hemostatic activity and reduce parenchymal hemorrhage 5-6 times compared to control.

  1. Integrin binding specificity regulates biomaterial surface chemistry effects on cell differentiation

    Keselowsky, Benjamin G.; Collard, David M.; Andrés J. García

    2005-01-01

    Biomaterial surface chemistry has profound consequences on cellular and host responses, but the underlying molecular mechanisms remain poorly understood. Using self-assembled monolayers as model biomaterial surfaces presenting well defined chemistries, we demonstrate that surface chemistry modulates osteoblastic differentiation and matrix mineralization independently from alterations in cell proliferation. Surfaces were precoated with equal densities of fibronectin (FN), and surface chemistry...

  2. Tissue response to a new type of biomaterial implanted subcutaneously in rats

    Boennelycke, Marie; Christensen, Lise; Nielsen, Lene Feldskov;

    2011-01-01

    A new type of resorbable biomaterial intended for pelvic reconstruction was tested with respect to tissue regeneration and biocompatibility in rats. The biomaterial consisted of methoxypolyethyleneglycol-poly (lactic-co-glycolic acid) (MPEG-PLGA). Implants were pure, enriched with extra...

  3. Arthroplasty implant biomaterial particle associated macrophages differentiate into lacunar bone resorbing cells.

    Pandey, R.; Quinn, J.; Joyner, C.; Murray, D W; Triffitt, J T; N. A. Athanasou

    1996-01-01

    OBJECTIVE: To study the pathogenesis of aseptic loosening: in particular, to determine whether macrophages responding to particles of biomaterials commonly used in arthroplasty surgery for arthritis are capable of differentiating into osteoclastic bone resorbing cells, and the cellular and hormonal conditions required for this to occur. METHODS: Biomaterial particles (polymethylmethacrylate, high density polyethylene, titanium, chromium-cobalt, stainless steel) were implanted subcutaneously i...

  4. The neural cell adhesion molecule

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  5. Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

    Jeong, Hoon Eui

    2010-02-16

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

  6. Improved Adhesion and Compliancy of Hierarchical Fibrillar Adhesives.

    Li, Yasong; Gates, Byron D; Menon, Carlo

    2015-08-01

    The gecko relies on van der Waals forces to cling onto surfaces with a variety of topography and composition. The hierarchical fibrillar structures on their climbing feet, ranging from mesoscale to nanoscale, are hypothesized to be key elements for the animal to conquer both smooth and rough surfaces. An epoxy-based artificial hierarchical fibrillar adhesive was prepared to study the influence of the hierarchical structures on the properties of a dry adhesive. The presented experiments highlight the advantages of a hierarchical structure despite a reduction of overall density and aspect ratio of nanofibrils. In contrast to an adhesive containing only nanometer-size fibrils, the hierarchical fibrillar adhesives exhibited a higher adhesion force and better compliancy when tested on an identical substrate. PMID:26167951

  7. Effect of adhesive thickness on adhesively bonded T-joint

    The aim of this work is to analyze the effect of adhesive thickness on tensile strength of adhesively bonded stainless steel T-joint. Specimens were made from SUS 304 Stainless Steel plate and SUS 304 Stainless Steel perforated plate. Four T-joint specimens with different adhesive thicknesses (0.5, 1.0, 1.5 and 2.0 mm) were made. Experiment result shows T-joint specimen with adhesive thickness of 1.0 mm yield highest maximum load. Identical T-joint specimen jointed by spot welding was also tested. Tensile test shows welded T-Joint had eight times higher tensile load than adhesively bonded T-joint. However, in low pressure application such as urea granulator chamber, high tensile strength is not mandatory. This work is useful for designer in fertilizer industry and others who are searching for alternative to spot welding

  8. Antimicrobial Biomaterials based on Single-Walled Carbon Nanotubes

    Aslan, Seyma

    Biomaterials that inactivate bacteria are needed to eliminate medical device infections. We investigate the antimicrobial nature of single-walled carbon nanotubes (SWNT) incorporated within biomedical polymers. In the first part, we focus on SWNT dispersed in the common biomedical polymer poly(lactic-co-glycolic acid) (PLGA) as a potential antimicrobial biomaterial. We find Escherichia coli and Staphylococcus epidermidis viability and metabolic activity to be significantly diminished in the presence of SWNT-PLGA, and to correlate with SWNT length and concentration. Up to 98 % of bacteria die within one hour of SWNT-PLGA versus 15-20% on pure PLGA. Shorter SWNT are found to be more toxic, possibly due to an increased density of open tube ends. In the second part, we investigate the antimicrobial activity of SWNT layer-by-layer (LbL) assembled with the polyelectrolytes poly(L-lysine) (PLL) and poly(L-glutamic acid) (PGA). The dispersibility of SWNT in aqueous solution is significantly improved via the biocompatible nonionic surfactant polyoxyethylene(20)sorbitan monolaurate (Tween 20) and the amphiphilic polymer phospholipid-poly(ethylene glycol) (PL-PEG). Absorbance spectroscopy and transmission electron microscopy (TEM) show SWNT with either Tween 20 or PL-PEG in aqueous solution to be well dispersed. Quartz crystal microgravimetry with dissipation (QCMD) measurements show both SWNT-Tween and SWNT-PL-PEG to LbL assemble with PLL and PGA into multilayer films, with the PL-PEG system yielding the greater final SWNT content. Bacterial inactivation rates are significantly higher (up to 90%) upon 24 hour incubation with SWNT containing films, compared to control films (ca. 20%). In the third part, we study the influence of bundling on the LbL assembly of SWNT with charged polymers, and on the antimicrobial properties of the assembled film. QCMD measurements show the bundled SWNT system to adsorb in an unusually strong fashion—to an extent three times greater than that

  9. Soy Protein Scaffold Biomaterials for Tissue Engineering and Regenerative Medicine

    Chien, Karen B.

    Developing functional biomaterials using highly processable materials with tailorable physical and bioactive properties is an ongoing challenge in tissue engineering. Soy protein is an abundant, natural resource with potential use for regenerative medicine applications. Preliminary studies show that soy protein can be physically modified and fabricated into various biocompatible constructs. However, optimized soy protein structures for tissue regeneration (i.e. 3D porous scaffolds) have not yet been designed. Furthermore, little work has established the in vivo biocompatibility of implanted soy protein and the benefit of using soy over other proteins including FDA-approved bovine collagen. In this work, freeze-drying and 3D printing fabrication processes were developed using commercially available soy protein to create porous scaffolds that improve cell growth and infiltration compared to other soy biomaterials previously reported. Characterization of scaffold structure, porosity, and mechanical/degradation properties was performed. In addition, the behavior of human mesenchymal stem cells seeded on various designed soy scaffolds was analyzed. Biological characterization of the cell-seeded scaffolds was performed to assess feasibility for use in liver tissue regeneration. The acute and humoral response of soy scaffolds implanted in an in vivo mouse subcutaneous model was also investigated. All fabricated soy scaffolds were modified using thermal, chemical, and enzymatic crosslinking to change properties and cell growth behavior. 3D printing allowed for control of scaffold pore size and geometry. Scaffold structure, porosity, and degradation rate significantly altered the in vivo response. Freeze-dried soy scaffolds had similar biocompatibility as freeze-dried collagen scaffolds of the same protein content. However, the soy scaffolds degraded at a much faster rate, minimizing immunogenicity. Interestingly, subcutaneously implanted soy scaffolds affected blood

  10. Syndecans, signaling, and cell adhesion

    Couchman, J R; Woods, A

    1996-01-01

    structures within the heparan sulfate chains, leaving the roles of chondroitin sulfate chains and extracellular portion of the core proteins to be elucidated. Evidence that syndecans are a class of receptor involved in cell adhesion is mounting, and their small cytoplasmic domains may link with the...... transmembrane signaling from matrix to cytoskeleton, as proposed for other classes of adhesion receptors....

  11. Cell adhesion on cellulose nanofibrils

    Liljeström, Anna

    2016-01-01

    Cellulose nanofibrils (CNF) is an emerging biomaterial suitable for medical research. CNF hydrogel has been used as a three dimensional platforms for cell culture. This thesis aims to understand how human liver carcinoma (HepG2) cells interact with CNF. Measurements were performed with Quartz crystal microbalance with dissipation in order to quantify cell adsorption on CNF. Furthermore, the effect of the cell medium on the viscoelastic properties of CNF and on cell-CNF interactions were ...

  12. Hyaluronan-mediated cellular adhesion

    Curtis, Jennifer

    2005-03-01

    Many cells surround themselves with a cushioning halo of polysaccharides that is further strengthened and organized by proteins. In fibroblasts and chrondrocytes, the primary component of this pericellular matrix is hyaluronan, a large linear polyanion. Hyaluronan production is linked to a variety of disease, developmental, and physiological processes. Cells manipulate the concentration of hyaluronan and hyaluronan receptors for numerous activities including modulation of cell adhesion, cell motility, and differentiation. Recent investigations by identify hyaluronan's role in mediating early-stage cell adhesion. An open question is how the cell removes the 0.5-10 micron thick pericellular matrix to allow for further mature adhesion events requiring nanometer scale separations. In this investigation, holographic optical tweezers are used to study the adhesion and viscoelastic properties of chondrocytes' pericellular matrix. Ultimately, we aim to shed further light on the spatial and temporal details of the dramatic transition from micron to nanometer gaps between the cell and its adhesive substrate.

  13. [Retention of adhesive bridges].

    Raes, F; De Boever, J

    1994-04-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rests, interocclusal clearance and cingulum stops is equally important. Including more teeth in the design does not necessarily lead to an improved retention. Besides the material and technical aspects, the whole clinical procedure needs much attention. The retention does not depend on one single factor, but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 80% can be obtained. PMID:11830965

  14. Soft X-ray emission studies of biomaterials

    Soft X-ray fluorescence measurements are used to characterize three groups of biomaterials: Vitamin B12 and derivatives, antioxidants (aspirin and paracetamol), and human teeth. We show that the chemical bonding in Vitamin B12 is characterized by the strong Co-C bond and the relatively weak Co-N bond. The Co-C bond in cyanocobalamin is found to be stronger than that of methylcobalamin leading to their different biological activity. The chemical bonding of paracetamol and aspirin is characterized by the formation of oxygen lone-pair π-orbitals, which can neutralize free radicals and therefore be related to antioxidant activity of these compounds. Carbon Kα emission spectra of a caries lesion suggest that the CaCO3 like phase exists in sound enamel and that a selective loss of carbonate occurs during the early stages of a caries attack

  15. Advances in Porous Biomaterials for Dental and Orthopaedic Applications

    Arndt F. Schilling

    2010-04-01

    Full Text Available The connective hard tissues bone and teeth are highly porous on a micrometer scale, but show high values of compression strength at a relatively low weight. The fabrication of porous materials has been actively researched and different processes have been developed that vary in preparation complexity and also in the type of porous material that they produce. Methodologies are available for determination of pore properties. The purpose of the paper is to give an overview of these methods, the role of porosity in natural porous materials and the effect of pore properties on the living tissues. The minimum pore size required to allow the ingrowth of mineralized tissue seems to be in the order of 50 µm: larger pore sizes seem to improve speed and depth of penetration of mineralized tissues into the biomaterial, but on the other hand impair the mechanical properties. The optimal pore size is therefore dependent on the application and the used material.

  16. Patterning biomaterials for the spatiotemporal delivery of bioactive molecules

    Silvia eMinardi

    2016-06-01

    Full Text Available The aim of tissue engineering is to promote the repair of functional tissues. For decades, the combined use of biomaterials, growth factors, and stem cells has been at the base of several regeneration strategies. Among these, biomimicry emerged as a robust strategy to efficiently address this clinical challenge. Biomimetic materials, able to recapitulate the composition and architecture of the extracellular matrix, are the materials of choice, for their biocompatibility and higher rate of efficacy. In addition, it has become increasingly clear that restoring the complex biochemical environment of the target tissue is crucial for its regeneration. Towards this aim, the combination of scaffolds and growth factors is required. The advent of nanotechnology significantly impacted the field of tissue engineering by providing new ways to reproduce the complex spatial and temporal biochemical patterns of tissues. This review will present the most recent approaches to finely control the spatiotemporal release of bioactive molecules for various tissue engineering applications.

  17. Patterning Biomaterials for the Spatiotemporal Delivery of Bioactive Molecules.

    Minardi, Silvia; Taraballi, Francesca; Pandolfi, Laura; Tasciotti, Ennio

    2016-01-01

    The aim of tissue engineering is to promote the repair of functional tissues. For decades, the combined use of biomaterials, growth factors (GFs), and stem cells has been the base of several regeneration strategies. Among these, biomimicry emerged as a robust strategy to efficiently address this clinical challenge. Biomimetic materials, able to recapitulate the composition and architecture of the extracellular matrix, are the materials of choice, for their biocompatibility and higher rate of efficacy. In addition, it has become increasingly clear that restoring the complex biochemical environment of the target tissue is crucial for its regeneration. Toward this aim, the combination of scaffolds and GFs is required. The advent of nanotechnology significantly impacted the field of tissue engineering by providing new ways to reproduce the complex spatial and temporal biochemical patterns of tissues. This review will present the most recent approaches to finely control the spatiotemporal release of bioactive molecules for various tissue engineering applications. PMID:27313997

  18. Contributions of human paleohistology to the study of biomaterials

    The deep study of archaeological human bone could provide relevant information to biomaterials science, as it could tell how the implant process of bio glasses and bioresorbable ceramics is. In this paper, we propose to study, by means of different microscopic, spectroscopic, and X-ray diffraction techniques, the histological and mineral bone variability throughout ontogeny. Extrapolating this data, we could have a better knowledge of biodegradable materials implant. In different ages, we could notice different tissues in cortical bone: fibrolamellar bone is characteristic of early stages of life while secondary or harvesian bone is in adult individuals. Raman and infrared spectroscopy suggest an increase of critallinity in the inorganic matrix during live. Finally, the X-ray diffraction study of bone tissue shows β-calcium phosphate and hydroxyapatite as the main mineral bone components. (Author) 31 refs.

  19. Patterning Biomaterials for the Spatiotemporal Delivery of Bioactive Molecules

    Minardi, Silvia; Taraballi, Francesca; Pandolfi, Laura; Tasciotti, Ennio

    2016-01-01

    The aim of tissue engineering is to promote the repair of functional tissues. For decades, the combined use of biomaterials, growth factors (GFs), and stem cells has been the base of several regeneration strategies. Among these, biomimicry emerged as a robust strategy to efficiently address this clinical challenge. Biomimetic materials, able to recapitulate the composition and architecture of the extracellular matrix, are the materials of choice, for their biocompatibility and higher rate of efficacy. In addition, it has become increasingly clear that restoring the complex biochemical environment of the target tissue is crucial for its regeneration. Toward this aim, the combination of scaffolds and GFs is required. The advent of nanotechnology significantly impacted the field of tissue engineering by providing new ways to reproduce the complex spatial and temporal biochemical patterns of tissues. This review will present the most recent approaches to finely control the spatiotemporal release of bioactive molecules for various tissue engineering applications. PMID:27313997

  20. Biomaterials and Implants in Cardiac and Vascular Surgery - Review

    Stanisławska A.

    2014-10-01

    Full Text Available Currently, on prosthesis in cardiac blood vessels and heart valves are used materials of animal or synthetic origin. For animal materials include, among others pericardial sac in which is the heart. Materials such as this (natural are characterized by a remarkable biocompatibility within the human body, but their main disadvantage is the relatively low durability. In turn, synthetic materials, which include the austenitic chromium-nickel-molybdenum steels, alloys with a shape memory (nickel-titanium, or polymeric materials, such as lactic acid, are characterized by high stability in an environment of bodily fluids, wherein the insufficiently high biocompatibility with the organism human requires from patients using after implantation, anticoagulants which prevent anti-platelet deposition on the surface of the prosthesis. The present work is a review of biomaterials using in implantology and implants using in cardiac and vascular surgery.

  1. Polysaccharide-based biomaterials with antimicrobial and antioxidant properties

    Véronique Coma

    2013-01-01

    Full Text Available Active packaging is one of the responses to the recent food-borne microbial outbreaks and to the consumer’s demand for high quality food and for packaging that is more advanced and creative than what is currently offered. Moreover, with the recent increase in ecological awareness associated with the dramatic decrease in fossil resources, research has turned towards the elaboration of more natural materials. This paper provides a short review of biomaterials exhibiting antimicrobial and antioxidant properties for applications in food preservation. The two main concepts of active biopackaging materials are briefly introduced. The different polysaccharides potentially used in packaging materials are then presented associated with a brief overview of research works related to biopackaging, exhibiting notably antimicrobial or antioxidant properties. Finally, future trends such as the release-on-demand of bioactive agents are discussed.

  2. Double site-bond percolation model for biomaterial implants

    Mely, H

    2011-01-01

    We present a double site-bond percolation model to account, on the one hand, for the vascularization and/or resorption of biomaterial implant in bones and, on the other hand, for its mechanical continuity. The transformation of the implant into osseous material, and the dynamical formation/destruction of this osseous material is accounted for by creation and destruction of links and sites in two, entangled, networks. We identify the relevant parameters to describe the implant and its evolution, and separate their biological or chemical origin from their physical one. We classify the various phenomena in the two regimes, percolating or non-percolating, of the networks. We present first numerical results in two dimensions.

  3. Neural engineering from advanced biomaterials to 3D fabrication techniques

    Kaplan, David

    2016-01-01

    This book covers the principles of advanced 3D fabrication techniques, stem cells and biomaterials for neural engineering. Renowned contributors cover topics such as neural tissue regeneration, peripheral and central nervous system repair, brain-machine interfaces and in vitro nervous system modeling. Within these areas, focus remains on exciting and emerging technologies such as highly developed neuroprostheses and the communication channels between the brain and prostheses, enabling technologies that are beneficial for development of therapeutic interventions, advanced fabrication techniques such as 3D bioprinting, photolithography, microfluidics, and subtractive fabrication, and the engineering of implantable neural grafts. There is a strong focus on stem cells and 3D bioprinting technologies throughout the book, including working with embryonic, fetal, neonatal, and adult stem cells and a variety of sophisticated 3D bioprinting methods for neural engineering applications. There is also a strong focus on b...

  4. Soft X-ray emission studies of biomaterials

    Kurmaev, E.Z. E-mail: kurmaev@ifmlrs.uran.ru; Werner, J.P.; Moewes, A.; Chiuzbaian, S.; Bach, M.; Ching, W.-Y.; Motozaki, W.; Otsuka, T.; Matsuya, S.; Endo, K.; Neumann, M

    2004-07-01

    Soft X-ray fluorescence measurements are used to characterize three groups of biomaterials: Vitamin B{sub 12} and derivatives, antioxidants (aspirin and paracetamol), and human teeth. We show that the chemical bonding in Vitamin B{sub 12} is characterized by the strong Co-C bond and the relatively weak Co-N bond. The Co-C bond in cyanocobalamin is found to be stronger than that of methylcobalamin leading to their different biological activity. The chemical bonding of paracetamol and aspirin is characterized by the formation of oxygen lone-pair {pi}-orbitals, which can neutralize free radicals and therefore be related to antioxidant activity of these compounds. Carbon K{alpha} emission spectra of a caries lesion suggest that the CaCO{sub 3} like phase exists in sound enamel and that a selective loss of carbonate occurs during the early stages of a caries attack.

  5. Gold nanoparticle-coated biomaterial as SERS micro-probes

    G V Pavan Kumar

    2011-06-01

    We report for the first time, on the utility of plant-based biomaterial as enhanced-Raman scattering probes. The bio-substrate used in this study are commonly found in plant extracts, and are cost-effective, mechanically robust, flexible and easily transportable. The probe was fabricated by coating the plant extract with gold nanoparticles and characterized. By employing a ‘single-touch contact’ method, we reveal the ability of these probes to detect routinely used Raman markers such as 2-napthalenethiol and rhodamine B, at nano-molar concentrations, in dry and liquid forms, respectively. Reproducibility of the signals with variation <5%, and the ability to detect biomolecules are demonstrated herein. We envision these bio-probes as potential candidates for enhanced Raman sensing in chemical, environmental, and archaeological applications. By further engineering the shape, morphology, and surface chemistry of these micro-probes, we foresee their utility as miniaturized, natural SERS substrates.

  6. Clinical study on orofacial photonic hydration using phototherapy and biomaterials

    Lizarelli, Rosane F. Z.; Grandi, Natália D. P.; Florez, Fernando L. E.; Grecco, Clovis; Lopes, Luciana A.

    2015-06-01

    Skin hydration is important to prevent aging and dysfunction of orofacial system. Nowadays, it is known that cutaneous system is linked to muscle system, then every dentist need to treat healthy facial skin, as lips, keeping orofacial functions healthy. Thirty-two patients were treated using laser and led therapy single or associated to biomaterials (dermo-cosmetics) searching for the best protocol to promote skin hydration. Using a peace of equipment to measure electric impedance, percentage of water and oil from skin, before and after different treatments were analyzed. Statistic tests using 5% and 0.1% of significance were applied and results showed that light could improve hydration of epidermis layer of facial skin. Considering just light effect, using infrared laser followed by blue led system is more effective to hydration than just blue led system application. Considering dermo-cosmetic and light, the association between both presented the best result.

  7. Design of biomaterials for intracellular delivery of carbon monoxide.

    Inaba, Hiroshi; Fujita, Kenta; Ueno, Takafumi

    2015-11-01

    Carbon monoxide (CO) is recognized as one of the most important gas signaling molecules involved in governing various therapeutic responses. Intracellular generation of CO is spatiotemporally controlled by catalytic reactions of heme oxygenases (HOs). Thus, the ability to control intracellular CO delivery with modulation of the CO-release rate in specific amounts and locations is expected to improve our fundamental understanding of the functions of CO and the development of clinical applications. For this purpose, CO-releasing molecules (CORMs) have been developed and investigated in vitro and in vivo. Most CORMs are based on transition metal carbonyl complexes. Recently, various biomaterials consisting of metal carbonyls with biomacromolecular scaffolds have been reported to improve the properties of bare metal carbonyls. In this mini-review, current progress in CO delivery, recent strategies for the development of CORMs, and future directions in this field are discussed. PMID:26252321

  8. Bone Regeneration Using Bone Morphogenetic Proteins and Various Biomaterial Carriers

    Zeeshan Sheikh

    2015-04-01

    Full Text Available Trauma and disease frequently result in fractures or critical sized bone defects and their management at times necessitates bone grafting. The process of bone healing or regeneration involves intricate network of molecules including bone morphogenetic proteins (BMPs. BMPs belong to a larger superfamily of proteins and are very promising and intensively studied for in the enhancement of bone healing. More than 20 types of BMPs have been identified but only a subset of BMPs can induce de novo bone formation. Many research groups have shown that BMPs can induce differentiation of mesenchymal stem cells and stem cells into osteogenic cells which are capable of producing bone. This review introduces BMPs and discusses current advances in preclinical and clinical application of utilizing various biomaterial carriers for local delivery of BMPs to enhance bone regeneration.

  9. Effect of fibril shape on adhesive properties

    Soto, Daniel; Hill, Ginel; Parness, Aaron; Esparza, Noé; Cutkosky, Mark; Kenny, Tom

    2010-08-01

    Research into the gecko's adhesive system revealed a unique architecture for adhesives using tiny hairs. By using a stiff material (β-keratin) to create a highly structured adhesive, the gecko's system demonstrates properties not seen in traditional pressure-sensitive adhesives which use a soft, unstructured planar layer. In contrast to pressure sensitive adhesives, the gecko adhesive displays frictional adhesion, in which increased shear force allows it to withstand higher normal loads. Synthetic fibrillar adhesives have been fabricated but not all demonstrate this frictional adhesion property. Here we report the dual-axis force testing of single silicone rubber pillars from synthetic adhesive arrays. We find that the shape of the adhesive pillar dictates whether frictional adhesion or pressure-sensitive behavior is observed. This work suggests that both types of behavior can be achieved with structures much larger than gecko terminal structures. It also indicates that subtle differences in the shape of these pillars can significantly influence their properties.

  10. Gloss measurements and rugometric inspection in dental biomaterials

    Fernández-Oliveras, Alicia; Costa, Manuel F. M.; Yebra, Ana; Rubiño, Manuel; Pérez, María. M.

    2013-11-01

    In dental applications, optimizing appearance is desirable and increasingly demanded by patients. The specular gloss is among the major appearance properties of dental biomaterials, and its relationship with surface roughness has been reported. Roughness and gloss are key surface aspects that complement each other. We have experimentally analyzed the specular gloss and surface roughness of two different types of dental-resin composites and pre-sintered and sintered zirconia ceramics. We have studied two shades of both composite types and two sintered zirconia ceramics: colored and uncolored. Moreover, a surface treatment was applied to one specimen of each dental resin. Gloss measurements were performed with a standardized reflectometer and the corresponding gloss percentages were calculated. All the samples were submitted to rugometric non-invasive inspection with the MICROTOP.06.MFC laser microtopographer in order to determine meaningful statistical parameters such as the average roughness (Ra) and the root-mean-square deviation (Rq). For a comparison of the different biomaterials, the uncertainties associated to the measure of the surface gloss and roughness were also determined. The differences between the two shades of both kinds of composites proved significant in the case of the roughness parameters but not for the specular gloss. The surface treatment applied to the dental-resin composites increased the average roughness but the changes in the specular gloss were significant only for the A2 enamel nano-composite. For the zirconia ceramic the sintered process resulted in an increase in the surface roughness with a decrease of the specular gloss, corroborating that the relationship between the gloss and the roughness shows the expected behavior.

  11. Fiber from ramie plant (Boehmeria nivea): A novel suture biomaterial.

    Kandimalla, Raghuram; Kalita, Sanjeeb; Choudhury, Bhaswati; Devi, Dipali; Kalita, Dhaneswar; Kalita, Kasturi; Dash, Suvakanta; Kotoky, Jibon

    2016-05-01

    The quest for developing an ideal suture material prompted our interest to develop a novel suture with advantageous characters to market available ones. From natural origin only silk, cotton and linen fibers are presently available in market as non-absorbable suture biomaterials. In this study, we have developed a novel, cost-effective, and biocompatible suture biomaterial from ramie plant, Boehmeria nivea fiber. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and thermo gravimetric analysis (TGA) results revealed the physicochemical properties of raw and degummed ramie fiber, where the former one showed desirable characteristics for suture preparation. The braided multifilament ramie suture prepared from degummed fiber exhibited excellent tensile strength. The suture found to be biocompatible towards human erythrocytes and nontoxic to mammalian cells. The fabricated ramie suture exhibited significant antibacterial activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus; which can be attributed to the inherent bacteriostatic ability of ramie plant fiber. In vivo wound closure efficacy was evaluated in adult male wister rats by suturing the superficial wound incisions. Within seven days of surgery the wound got completely healed leaving no rash and scar. The role of the ramie suture in complete wound healing was supported by the reduced levels of serum inflammatory mediators. Histopathology studies confirmed the wound healing ability of ramie suture, as rapid synthesis of collagen, connective tissue and other skin adnexal structures were observed within seven days of surgery. Tensile properties, biocompatibility and wound closure efficacy of the ramie suture were comparable with market available BMSF suture. The outcome of this study can drive tremendous possibility for the utilization of ramie plant fiber for

  12. Fatigue behavior of porous biomaterials manufactured using selective laser melting.

    Yavari, S Amin; Wauthle, R; van der Stok, J; Riemslag, A C; Janssen, M; Mulier, M; Kruth, J P; Schrooten, J; Weinans, H; Zadpoor, A A

    2013-12-01

    Porous titanium alloys are considered promising bone-mimicking biomaterials. Additive manufacturing techniques such as selective laser melting allow for manufacturing of porous titanium structures with a precise design of micro-architecture. The mechanical properties of selective laser melted porous titanium alloys with different designs of micro-architecture have been already studied and are shown to be in the range of mechanical properties of bone. However, the fatigue behavior of this biomaterial is not yet well understood. We studied the fatigue behavior of porous structures made of Ti6Al4V ELI powder using selective laser melting. Four different porous structures were manufactured with porosities between 68 and 84% and the fatigue S-N curves of these four porous structures were determined. The three-stage mechanism of fatigue failure of these porous structures is described and studied in detail. It was found that the absolute S-N curves of these four porous structures are very different. In general, given the same absolute stress level, the fatigue life is much shorter for more porous structures. However, the normalized fatigue S-N curves of these four structures were found to be very similar. A power law was fitted to all data points of the normalized S-N curves. It is shown that the measured data points conform to the fitted power law very well, R(2)=0.94. This power law may therefore help in estimating the fatigue life of porous structures for which no fatigue test data is available. It is also observed that the normalized endurance limit of all tested porous structures (<0.2) is lower than that of corresponding solid material (c.a. 0.4). PMID:24094196

  13. Tuneable nanoparticle-nanofiber composite substrate for improved cellular adhesion.

    Nicolini, Ariana M; Toth, Tyler D; Yoon, Jeong-Yeol

    2016-09-01

    This work presents a novel technique using a reverse potential electrospinning mode for fabricating nanoparticle-embedded composites that can be tailored to represent various fiber diameters, surface morphologies, and functional groups necessary for improved cellular adhesion. Polycaprolactone (PCL) nanofibers were electrospun in both traditional positive (PP) and reverse potential (RP) electrical fields. The fibers were incorporated with 300nm polystyrene (PS) fluorescent particles, which contained carboxyl, amine groups, and surfactants. In the unconventional RP, the charged colloidal particles and surfactants were shown to have an exaggerated effect on Taylor cone morphology and fiber diameter caused by the changes in charge density and surface tension of the bulk solution. The RP mode was shown to lead to a decrease in fiber diameter from 1200±100nm (diameter±SE) for the nanofibers made with PCL alone to 440±80nm with the incorporation of colloidal particles, compared to the PP mode ranging from 530±90nm to 350±50nm, respectively. The nanoparticle-nanofiber composite substrates were cultured with human umbilical vein endothelial cells (HUVECs) and evaluated for cellular viability and adhesion for up to 5 days. Adhesion to the nanofibrous substrates was improved by 180±10% with the addition of carboxylated particles and by 480±60% with the functionalization of an RGD ligand compared to the PCL nanofibers. The novel approach of electrospinning in the RP mode with the addition of colloids in order to alter charge density and surface tension could be utilized towards many applications, one being implantable biomaterials and tissue engineered scaffolds as demonstrated in this work. PMID:27315331

  14. Impact of oils and coatings on adhesion of structural adhesives

    Hagström, Marcus

    2015-01-01

    This is a master thesis project conducted for Scania CV AB in collaboration with Swerea Kimab. The purpose is to examine how oils and coatings on the surface affect the adhesion of adhesives. Earlier work done by Scania indicate that the amount of oil applied may have an impact on the adhesion. Substrates tested are hot dipped galvanised steel, electro galvanised. AlSi and ZnMg. Oils used are Anticorit RP 3802 that is an anti-corrosive oil and Renoform 3802 that is a drawing oil. The two adhes...

  15. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Neil J Shirtcliffe

    Full Text Available Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted, texture (smooth, rough or granular or wetting property (hydrophilic or hydrophobic via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  16. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    Shirtcliffe, Neil J.; McHale, Glen; Newton, Michael I.

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces. PMID:22693563

  17. Marine Bioinspired Underwater Contact Adhesion.

    Clancy, Sean K; Sodano, Antonio; Cunningham, Dylan J; Huang, Sharon S; Zalicki, Piotr J; Shin, Seunghan; Ahn, B Kollbe

    2016-05-01

    Marine mussels and barnacles are sessile biofouling organisms that adhere to a number of surfaces in wet environments and maintain remarkably strong bonds. Previous synthetic approaches to mimic biological wet adhesive properties have focused mainly on the catechol moiety, present in mussel foot proteins (mfps), and especially rich in the interfacial mfps, for example, mfp-3 and -5, found at the interface between the mussel plaque and substrate. Barnacles, however, do not use Dopa for their wet adhesion, but are instead rich in noncatecholic aromatic residues. Due to this anomaly, we were intrigued to study the initial contact adhesion properties of copolymerized acrylate films containing the key functionalities of barnacle cement proteins and interfacial mfps, for example, aromatic (catecholic or noncatecholic), cationic, anionic, and nonpolar residues. The initial wet contact adhesion of the copolymers was measured using a probe tack testing apparatus with a flat-punch contact geometry. The wet contact adhesion of an optimized, bioinspired copolymer film was ∼15.0 N/cm(2) in deionized water and ∼9.0 N/cm(2) in artificial seawater, up to 150 times greater than commercial pressure-sensitive adhesive (PSA) tapes (∼0.1 N/cm(2)). Furthermore, maximum wet contact adhesion was obtained at ∼pH 7, suggesting viability for biomedical applications. PMID:27046671

  18. Adhesion and multi-materials

    Adhesion is a multidisciplinary science relevant to many practical fields. The main application of adhesion is bonding by adhesives. This technique is widely used in the industrial world and more specifically in the advanced technical domains. Adhesion is also involved in multi-component materials such as coatings, multilayer materials, polymer blends, composite materials... The multidisciplinary aspect of adhesion is well demonstrated by considering the wide variety of concepts, models and theories proposed for its description. An example of the adhesion between a fiber and a matrix in a composite material will lead to a general model relating the molecular properties of the interface to its capacity of stress transfer and hence to the macroscopic mechanical properties of the composite. This relationship is valid whatever the fiber (glass, carbon, polymeric) or the polymer matrix (thermoplastics, thermosetting). Any deviation from this model can be attributed to the existence of an interfacial zone or interphase exhibiting properties, mainly mechanical properties, different from the bulk matrix. Two examples are examined: the first one deals with the creation of a trans crystalline interphase in a semi-crystalline thermoplastic matrix and the second one is concerned with the formation of a pseudo glassy interphase in an elastomer matrix. These examples stress the need for complementary approaches in the understanding of adhesion phenomena at different levels of knowledge, from molecular to macroscopic. They also show how important it is to understand the mechanisms of formation of inter phases in order to be able to master the performance of multicomponent materials. (Author)

  19. Developing a pro-regenerative biomaterial scaffold microenvironment requires T helper 2 cells.

    Sadtler, Kaitlyn; Estrellas, Kenneth; Allen, Brian W; Wolf, Matthew T; Fan, Hongni; Tam, Ada J; Patel, Chirag H; Luber, Brandon S; Wang, Hao; Wagner, Kathryn R; Powell, Jonathan D; Housseau, Franck; Pardoll, Drew M; Elisseeff, Jennifer H

    2016-04-15

    Immune-mediated tissue regeneration driven by a biomaterial scaffold is emerging as an innovative regenerative strategy to repair damaged tissues. We investigated how biomaterial scaffolds shape the immune microenvironment in traumatic muscle wounds to improve tissue regeneration. The scaffolds induced a pro-regenerative response, characterized by an mTOR/Rictor-dependent T helper 2 pathway that guides interleukin-4-dependent macrophage polarization, which is critical for functional muscle recovery. Manipulating the adaptive immune system using biomaterials engineering may support the development of therapies that promote both systemic and local pro-regenerative immune responses, ultimately stimulating tissue repair. PMID:27081073

  20. Focal Adhesion Kinases in Adhesion Structures and Disease

    Pierre P. Eleniste

    2012-01-01

    Full Text Available Cell adhesion to the extracellular matrix (ECM is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases.

  1. Focal adhesion kinases in adhesion structures and disease.

    Eleniste, Pierre P; Bruzzaniti, Angela

    2012-01-01

    Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases. PMID:22888421

  2. Photovoltaic module with adhesion promoter

    Xavier, Grace

    2013-10-08

    Photovoltaic modules with adhesion promoters and methods for fabricating photovoltaic modules with adhesion promoters are described. A photovoltaic module includes a solar cell including a first surface and a second surface, the second surface including a plurality of interspaced back-side contacts. A first glass layer is coupled to the first surface by a first encapsulating layer. A second glass layer is coupled to the second surface by a second encapsulating layer. At least a portion of the second encapsulating layer is bonded directly to the plurality of interspaced back-side contacts by an adhesion promoter.

  3. Adhesives from modified soy protein

    Sun, Susan; Wang, Donghai; Zhong, Zhikai; Yang, Guang

    2008-08-26

    The, present invention provides useful adhesive compositions having similar adhesive properties to conventional UF and PPF resins. The compositions generally include a protein portion and modifying ingredient portion selected from the group consisting of carboxyl-containing compounds, aldehyde-containing compounds, epoxy group-containing compounds, and mixtures thereof. The composition is preferably prepared at a pH level at or near the isoelectric point of the protein. In other preferred forms, the adhesive composition includes a protein portion and a carboxyl-containing group portion.

  4. Focal Adhesion Kinases in Adhesion Structures and Disease

    Pierre P. Eleniste; Angela Bruzzaniti

    2012-01-01

    Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organiza...

  5. In vitro adhesion of staphylococci to diamond-like carbon polymer hybrids under dynamic flow conditions.

    Soininen, Antti; Levon, Jaakko; Katsikogianni, Maria; Myllymaa, Katja; Lappalainen, Reijo; Konttinen, Yrjö T; Kinnari, Teemu J; Tiainen, Veli-Matti; Missirlis, Yannis

    2011-03-01

    This study compares the ability of selected materials to inhibit adhesion of two bacterial strains commonly implicated in implant-related infections. These two strains are Staphylococcus aureus (S-15981) and Staphylococcus epidermidis (ATCC 35984). In experiments we tested six different materials, three conventional implant metals: titanium, tantalum and chromium, and three diamond-like carbon (DLC) coatings: DLC, DLC-polydimethylsiloxane hybrid (DLC-PDMS-h) and DLC-polytetrafluoroethylene hybrid (DLC-PTFE-h) coatings. DLC coating represents extremely hard material whereas DLC hybrids represent novel nanocomposite coatings. The two DLC polymer hybrid films were chosen for testing due to their hardness, corrosion resistance and extremely good non-stick (hydrophobic and oleophobic) properties. Bacterial adhesion assay tests were performed under dynamic flow conditions by using parallel plate flow chambers (PPFC). The results show that adhesion of S. aureus to DLC-PTFE-h and to tantalum was significantly (P coating showed as low susceptibility to S. aureus adhesion as all the tested conventional implant metals. The adherence of S. epidermidis to biomaterials was not significantly (P coating without increasing the risk of implant-related infections. PMID:21243516

  6. A High-Adhesive Lysine-Cyclic RGD Peptide Designed for Selective Cell Retention Technology.

    Luo, Keyu; Mei, Tieniu; Li, Zhiqiang; Deng, Moyuan; Zhang, Zehua; Hou, Tianyong; Dong, Shiwu; Xie, Zhao; Xu, Jianzhong; Luo, Fei

    2016-06-01

    Cell adhesion is an important property of biomaterials used in selective cell retention (SCR) technology, which fabricates bone grafts rapidly in clinical settings. This could be improved by physical and biologic manipulations. To facilitate retention of the cells on the scaffold, especially osteoprogenitors from bone marrow in the convenient SCR procedure, a lysine-cyclic RGD (LcRGD) peptide was here designed to coordinate positively charged amino acids and the RGD sequence to enhance the adhesion performance of the scaffold. Demineralized bone matrix (DBM) is an important therapeutic resource, but its cell adhesion ability and osteoinductive capacity are low because of its processing. These capabilities can be increased to enhance the performance of DBM when used in SCR technology. Here, LcRGD peptide was used to modify DBM and produce a DBM/LcRGD composite. This composite exhibited enhanced adhesion performance on cultured human bone marrow-derived mesenchymal stem cells and retained more osteoprogenitors from bone marrow than other materials did. The DBM/LcRGD composite displayed a preferable osteoinduction in vitro and osteogenic capacity in vivo. Thus, LcRGD peptide as a commendable modifier of DBM applied in SCR technology can improve bone transplantation. PMID:27154386

  7. Hyaluronic acid biomaterials for perspective peripheral nerve regeneration

    Ouasti, Sihem

    2012-01-01

    This project focused on the design of a cellular scaffold applicable for the promotion of peripheral nerve regeneration. Firstly, we established a correlation between the organization of HA/PEG co-polymeric networks to their mechanical and degradability properties; cell adhesion was conferred to all gels by the incorporation of RGD peptides. Three families of hydrogels were produced using different procedures to permit an increasing physical incorporation of HA into a PEGDA-based network. Fro...

  8. Denture Adhesives - A Literature Review

    Sudhanshu Shekhar

    2016-06-01

    Full Text Available Successful complete denture treatment combines exemplary technique, effective patient rapport and education and familiarity with all possible management options to provide the highest degree of patient satisfaction. Dentists need to know about denture adhesives to be able to identify those patients who actually need them and to be able to educate them about the advantages, disadvantages and correct use of these products. Denture adhesives are commercially available nontoxic, soluble materials that when applied to the tissue surface of dentures enhance their retention, stability and performance. They were introduced in dentistry in the late 18th century. The first patent related to adhesives was issued in 1913, followed in the 1920’s and 1930’s. The purpose of the use of denture adhesives can be described as to subjectively benefit denture-wearers with improved stability, retention and comfort of their dentures, and with improved incisal force, masticatory ability, and confidence.

  9. Comparative evaluation of the three different surface treatments - conventional, laser and Nano technology methods in enhancing the surface characteristics of commercially pure titanium discs and their effects on cell adhesion: An in vitro study

    Vignesh

    2015-01-01

    Full Text Available The surface area of the titanium dental implant materials can be increased by surface treatments without altering their shape and form, thereby increasing the biologic properties of the biomaterial. A good biomaterial helps in early cell adhesion and cell signaling. In this study, the commercially pure titanium surfaces were prepared to enable machined surfaces to form a control material and to be compared with sandblasted and acid-etched surfaces, laser treated surfaces and titanium dioxide (20 nm Nano-particle coated surfaces. The surface elements were characterized. The biocompatibility was evaluated by cell culture in vitro using L929 fibroblasts. The results suggested that the titanium dioxide Nano-particle coated surfaces had good osteoconductivity and can be used as a potential method for coating the biomaterial.

  10. Comparative evaluation of the three different surface treatments – conventional, laser and Nano technology methods in enhancing the surface characteristics of commercially pure titanium discs and their effects on cell adhesion: An in vitro study

    Vignesh; Nayar, Sanjna; Bhuminathan; Mahadevan; Santhosh, S.

    2015-01-01

    The surface area of the titanium dental implant materials can be increased by surface treatments without altering their shape and form, thereby increasing the biologic properties of the biomaterial. A good biomaterial helps in early cell adhesion and cell signaling. In this study, the commercially pure titanium surfaces were prepared to enable machined surfaces to form a control material and to be compared with sandblasted and acid-etched surfaces, laser treated surfaces and titanium dioxide (20 nm) Nano-particle coated surfaces. The surface elements were characterized. The biocompatibility was evaluated by cell culture in vitro using L929 fibroblasts. The results suggested that the titanium dioxide Nano-particle coated surfaces had good osteoconductivity and can be used as a potential method for coating the biomaterial. PMID:26015762

  11. Biomaterials for Pelvic Floor Reconstructive Surgery: How Can We Do Better?

    Giulia Gigliobianco

    2015-01-01

    Full Text Available Stress urinary incontinence (SUI and pelvic organ prolapse (POP are major health issues that detrimentally impact the quality of life of millions of women worldwide. Surgical repair is an effective and durable treatment for both conditions. Over the past two decades there has been a trend to enforce or reinforce repairs with synthetic and biological materials. The determinants of surgical outcome are many, encompassing the physical and mechanical properties of the material used, and individual immune responses, as well surgical and constitutional factors. Of the current biomaterials in use none represents an ideal. Biomaterials that induce limited inflammatory response followed by constructive remodelling appear to have more long term success than biomaterials that induce chronic inflammation, fibrosis and encapsulation. In this review we draw upon published animal and human studies to characterize the changes biomaterials undergo after implantation and the typical host responses, placing these in the context of clinical outcomes.

  12. The Role of Biomaterials on Cancer Stem Cell Enrichment and Behavior

    Ordikhani, Faride; Kim, Yonghyun; Zustiak, Silviya P.

    2015-11-01

    The theory of cancer stem cells (CSCs) and their role in cancer metastasis, tumorigenicity and resistance to therapy is slowly shifting the emphasis on the search for cancer cure: more evidence is surfacing that a successful therapy should be geared against this rare cancer cell population. Unfortunately, CSCs are difficult to culture in vitro which severely limits the progress of CSC research. This review gives a brief overview of CSCs and their microenvironment, with particular focus on studies that used in vitro biomaterial-based models and biomaterial/CSC interfaces for the enrichment of CSCs. Biomaterial properties relevant to CSC behaviors are also addressed. While the discussed research field is still in its infancy, it appears that in vitro cancer models that include a biomaterial can support CSC enrichment and this has proved indispensable to the study of their biology as well as the development of novel cancer therapies.

  13. The usage of three-dimensional nanostructurized biomaterials in experimental and clinical oncology

    Sergeeva; N.; S.; Reshetov; I.; V.; Sviridova; I.; K.; Kirsanova; V.; A.; Achmedova; S.; A.; Barinov; S.; M.; Komlev; V.; S.; Samoylovich; M.; I.; Belyanin; A.; F.; Kleshcheva; S.; M.; Elinson; V.; M.

    2005-01-01

    The usage of biotransplants for substitution of tissue defects (in particular in reconstructive surgery in oncology) require both he suitable cell cultures and different biomaterials with definite and regulate properties.……

  14. The usage of three-dimensional nanostructurized biomaterials in experimental and clinical oncology

    2005-01-01

    @@ The usage of biotransplants for substitution of tissue defects (in particular in reconstructive surgery in oncology) require both he suitable cell cultures and different biomaterials with definite and regulate properties.

  15. Design, clinical translation and immunological response of biomaterials in regenerative medicine

    Sadtler, Kaitlyn; Singh, Anirudha; Wolf, Matthew T.; Wang, Xiaokun; Pardoll, Drew M.; Elisseeff, Jennifer H.

    2016-07-01

    The field of regenerative medicine aims to replace tissues lost as a consequence of disease, trauma or congenital abnormalities. Biomaterials serve as scaffolds for regenerative medicine to deliver cells, provide biological signals and physical support, and mobilize endogenous cells to repair tissues. Sophisticated chemistries are used to synthesize materials that mimic and modulate native tissue microenvironments, to replace form and to elucidate structure–function relationships of cell–material interactions. The therapeutic relevance of these biomaterial properties can only be studied after clinical translation, whereby key parameters for efficacy can be defined and then used for future design. In this Review, we present the development and translation of biomaterials for two tissue engineering targets, cartilage and cornea, both of which lack the ability to self-repair. Finally, looking to the future, we discuss the role of the immune system in regeneration and the potential for biomaterial scaffolds to modulate immune signalling to create a pro-regenerative environment.

  16. Laser surface modification and adhesion

    Mittal, K L

    2014-01-01

    The book provides a unique overview on laser techniques and applications for the purpose of improving adhesion by altering surface chemistry and topography/morphology of the substrate. It details laser surface modification techniques for a wide range of industrially relevant materials (plastics, metals, ceramics, composites) with the aim to improve and enhance their adhesion to other materials. The joining of different materials is of critical importance in the fabrication of many and varied products.

  17. Notch-Mediated Cell Adhesion

    Akihiko Murata; Shin-Ichi Hayashi

    2016-01-01

    Notch family members are generally recognized as signaling molecules that control various cellular responses in metazoan organisms. Early fly studies and our mammalian studies demonstrated that Notch family members are also cell adhesion molecules; however, information on the physiological roles of this function and its origin is limited. In this review, we discuss the potential present and ancestral roles of Notch-mediated cell adhesion in order to explore its origin and the initial roles of...

  18. Adhesive capsulitis: a case report

    Kazemi, Mohsen

    2000-01-01

    Adhesive capsulitis or frozen shoulder is an uncommon entity in athletes. However, it is a common cause of shoulder pain and disability in the general population. Although it is a self limiting ailment, its rather long, restrictive and painful course forces the affected person to seek treatment. Conservative management remains the mainstay treatment of adhesive capsulitis. This includes chiropractic manipulation of the shoulder, therapeutic modalities, mobilization, exercise, soft tissue ther...

  19. Effects of sterilization treatments on bulk and surface properties of nanocomposite biomaterials

    Ahmed, Maqsood; Punshon, Geoffrey; Darbyshire, Arnold; Seifalian, Alexander M

    2013-01-01

    With the continuous and expanding use of implantable biomaterials in a clinical setting, this study aims to elucidate the influence of sterilization techniques on the material surface and bulk properties of two polyurethane nanocomposite biomaterials. Both solid samples and porous membranes of nondegradable polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) and a biodegradable poly(caprolactone-urea) urethane (POSS-PCL) were examined. Sterilization techniques includ...

  20. Building Bridges: Leveraging Interdisciplinary Collaborations in the Development of Biomaterials to Meet Clinical Needs

    Fong, Eliza L. S.; Watson, Brendan M.; Kasper, F. Kurtis; Mikos, Antonios G.

    2012-01-01

    Our laboratory at Rice University has forged numerous collaborations with clinicians and basic scientists over the years to advance the development of novel biomaterials and modification of existing materials to meet clinical needs. This review highlights collaborative advances in biomaterials research from our laboratory in the areas of scaffold development, drug delivery and gene therapy, especially as related to applications in bone and cartilage tissue engineering.

  1. Biomaterials as carrier, barrier and reactor for cell-based regenerative medicine

    Qi, Chunxiao; Yan, Xiaojun; Huang, Chenyu; Melerzanov, Alexander; Du, Yanan

    2015-01-01

    Cell therapy has achieved tremendous success in regenerative medicine in the past several decades. However, challenges such as cell loss, death and immune-rejection after transplantation still persist. Biomaterials have been designed as carriers to deliver cells to desirable region for local tissue regeneration; as barriers to protect transplanted cells from host immune attack; or as reactors to stimulate host cell recruitment, homing and differentiation. With the assistance of biomaterials, ...

  2. The Influence of Maggot Excretions on PAO1 Biofilm Formation on Different Biomaterials

    Cazander, Gwendolyn; van Veen, Kiril E. B.; Bouwman, Lee H.; Bernards, Alexandra T.; Jukema, Gerrolt N.

    2008-01-01

    Biofilm formation in wounds and on biomaterials is increasingly recognized as a problem. It therefore is important to focus on new strategies for eradicating severe biofilm-associated infections. The beneficial effects of maggots (Lucilia sericata) in wounds have been known for centuries. We hypothesized sterile maggot excretions and secretions (ES) could prevent, inhibit, and break down biofilms of Pseudomonas aeruginosa (PAO1) on different biomaterials. Therefore, we investigated biofilm fo...

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

    Ye Li; Shu-Kui Chen; Long Li; Ling Qin; Xin-Luan Wang; Yu-Xiao Lai

    2015-01-01

    Large bone defects are serious complications that are most commonly caused by extensive trauma, tumour, infection, or congenital musculoskeletal disorders. If nonunion occurs, implantation for repairing bone defects with biomaterials developed as a defect filler, which can promote bone regeneration, is essential. In order to evaluate biomaterials to be developed as bone substitutes for bone defect repair, it is essential to establish clinically relevant in vitro and in vivo testing models for...

  4. Advanced biomaterials for repairing the nervous system: what can hydrogels do for the brain?

    Khaing, Zin Z.; Richelle C. Thomas; Geissler, Sydney A.; Schmidt, Christine E.

    2014-01-01

    Newly developed hydrogels are likely to play significant roles in future therapeutic strategies for the nervous system. In this review, unique features of the central nervous system (i.e., the brain and spinal cord) that are important to consider in developing engineered biomaterials for therapeutic applications are discussed. This review focuses on recent findings in hydrogels as biomaterials for use as (1) drug delivery devices, specifically focusing on how the material can change the deliv...

  5. Effect of Processing on Silk-Based Biomaterials: Reproducibility and Biocompatibility

    Wray, Lindsay S.; Hu, Xiao; Gallego, Jabier; Georgakoudi, Irene; Omenetto, Fiorenzo G.; Schmidt, Daniel; Kaplan, David L.

    2011-01-01

    Silk fibroin has been successfully used as a biomaterial for tissue regeneration. In order to prepare silk fibroin biomaterials for human implantation a series of processing steps are required to purify the protein. Degumming to remove inflammatory sericin is a crucial step related to biocompatibility and variability in the material. Detailed characterization of silk fibroin degumming is reported. The degumming conditions significantly affected cell viability on the silk fibroin material and ...

  6. The influence of substrate topography and biomaterial substance on skin wound healing

    Ghanavati, Zeinab; Neisi, Niloofar; Bayati, Vahid; Makvandi, Manoochehr

    2015-01-01

    Tissue engineering is a new field of which the main purpose is to regenerate and repair the damaged tissues. Scaffolds serve as three dimensional matrices for neo-organogenesis and their substance can be biologic or synthetic. Natural polymers have good interactions with the cells and synthetic biomaterials are also highly useful in biomedical application because of their biocompatible properties. In addition to scaffold substance, surface properties of biomaterials have an important role in ...

  7. Opportunities and challenges for the development of polymer-based biomaterials and medical devices

    Yin, Jinghua

    2016-01-01

    Biomaterials and medical devices are broadly used in the diagnosis, treatment, repair, replacement or enhancing functions of human tissues or organs. Although the living conditions of human beings have been steadily improved in most parts of the world, the incidence of major human’s diseases is still rapidly growing mainly because of the growth and aging of population. The compound annual growth rate of biomaterials and medical devices is projected to maintain around 10% in the next 10 years; and the global market sale of biomaterials and medical devices is estimated to reach $400 billion in 2020. In particular, the annual consumption of polymeric biomaterials is tremendous, more than 8000 kilotons. The compound annual growth rate of polymeric biomaterials and medical devices will be up to 15–30%. As a result, it is critical to address some widespread concerns that are associated with the biosafety of the polymer-based biomaterials and medical devices. Our group has been actively worked in this direction for the past two decades. In this review, some key research results will be highlighted. PMID:27047681

  8. The dorsal skinfold chamber: window into the dynamic interaction of biomaterials with their surrounding host tissue

    MW Laschke

    2011-09-01

    Full Text Available The implantation of biomaterials into the human body has become an indispensable part of almost all fields of modern medicine. Accordingly, there is an increasing need for appropriate approaches, which can be used to evaluate the suitability of different biomaterials for distinct clinical indications. The dorsal skinfold chamber is a sophisticated experimental model, which has been proven to be extremely valuable for the systematic in vivo analysis of the dynamic interaction of small biomaterial implants with the surrounding host tissue in rats, hamsters and mice. By means of intravital fluorescence microscopy, this chronic model allows for repeated analyses of various cellular, molecular and microvascular mechanisms, which are involved in the early inflammatory and angiogenic host tissue response to biomaterials during the initial 2-3 weeks after implantation. Therefore, the dorsal skinfold chamber has been broadly used during the last two decades to assess the in vivo performance of prosthetic vascular grafts, metallic implants, surgical meshes, bone substitutes, scaffolds for tissue engineering, as well as for locally or systemically applied drug delivery systems. These studies have contributed to identify basic material properties determining the biocompatibility of the implants and vascular ingrowth into their surface or internal structures. Thus, the dorsal skinfold chamber model does not only provide deep insights into the complex interactions of biomaterials with the surrounding soft tissues of the host but also represents an important tool for the future development of novel biomaterials aiming at an optimisation of their biofunctionality in clinical practice.

  9. Assessment of urinary tract biomaterial encrustation using a modified Robbins device continuous flow model.

    Tunney, M M; Keane, P F; Gorman, S P

    1997-01-01

    Encrustation of biomaterials employed in the urinary tract remains a major problem resulting in obstruction or blockage of catheters and stents. Therefore, resistance to encrustation is a desirable feature of biomaterials employed in such devices. The novel assessment of biomaterial encrustation employing a continuous flow model based on a modified Robbins device is described. Artificial urine was used in conjunction with 5% CO2 to simulate the physiological environment within the upper urinary tract. The widely used urinary device biomaterials, silicone and polyurethane, were investigated in the model for hydroxyapatite and struvite encrustation. Scanning electron microscopy, energy dispersive X-ray analysis, and atomic absorption spectroscopy all showed that silicone was less prone to encrustation than polyurethane and that hydroxyapatite deposition was predominant on both surfaces. The model has the advantage that a large number of biomaterials may be investigated simultaneously because several Robbins devices may be placed in parallel. The model is recommended for comparative evaluation of biomaterial candidates for use in urinary tract devices. PMID:9178735

  10. Anelastic spectroscopy in a Ti alloy used as biomaterial

    Ti and its alloys have been used thoroughly in the production of prostheses and dental implants due to their properties, such as high corrosion resistance, low elasticity modulus and high mechanical strength/density relation. Among the Ti-based alloys, the Ti-35Nb-7Zr-5Ta (TNZT) is one that presents the smallest elasticity modulus, making it an excellent alternative to be used as a biomaterial. In this paper, mechanical spectroscopy measurements were made in TNZT alloys containing several quantities of oxygen and nitrogen in solid solution. Mechanical spectroscopy measurements were made by using a torsion pendulum, operating at an oscillation frequency in the interval 4-30 Hz, temperature in the range 100-700 K, heating rate of about 1 K/min and vacuum lower than 10-5 Torr. Complex relaxation structures and a reduction in the elasticity modulus were observed for the heat-treated and doped samples. The observed peaks were associated with the interactions of interstitial atoms and the alloy elements.

  11. Biomaterial imaging with MeV-energy heavy ion beams

    The spatial distribution of several chemical compounds in biological tissues and cells can be obtained with mass spectrometry imaging (MSI). In conventional secondary ion mass spectrometry (SIMS) with keV-energy ion beams, elastic collisions occur between projectiles and atoms of constituent molecules. The collisions produce fragments, making the acquisition of molecular information difficult. In contrast, ion beams with MeV-energy excite near-surface electrons and enhance the ionization of high-mass molecules; hence, SIMS spectra of fragment-suppressed ionized molecules can be obtained with MeV-SIMS. To compare between MeV and conventional SIMS, we used the two methods based on MeV and Bi3-keV ions, respectively, to obtain molecular images of rat cerebellum. Conventional SIMS images of m/z 184 were clearly observed, but with the Bi3 ion, the distribution of the molecule with m/z 772.5 could be observed with much difficulty. This effect was attributed to the low secondary ion yields and we could not get many signal counts with keV-energy beam. On the other hand, intact molecular ion distributions of lipids were clearly observed with MeV-SIMS, although the mass of all lipid molecules was higher than 500 Da. The peaks of intact molecular ions in MeV-SIMS spectra allowed us to assign the mass. The high secondary ion sensitivity with MeV-energy heavy ions is very useful in biomaterial analysis

  12. Coaxial additive manufacture of biomaterial composite scaffolds for tissue engineering

    An inherent difficulty associated with the application of suitable bioscaffolds for tissue engineering is the incorporation of adequate mechanical characteristics into the materials which recapitulate that of the native tissue, whilst maintaining cell proliferation and nutrient transfer qualities. Biomaterial composites fabricated using rapid prototyping techniques can potentially improve the functionality and patient-specific processing of tissue engineering scaffolds. In this work, a technique for the coaxial melt extrusion printing of core-shell scaffold structures was designed, implemented and assessed with respect to the repeatability, cell efficacy and scaffold porosity obtainable. Encapsulated alginate hydrogel/thermoplastic polycaprolactone (Alg-PCL) cofibre scaffolds were fabricated. Selective laser melting was used to produce a high resolution stainless steel 316 L coaxial extrusion nozzle, exhibiting diameters of 300 μm/900 μm for the inner and outer nozzles respectively. We present coaxial melt extrusion printed scaffolds of Alg-PCL cofibres with ∼0.4 volume fraction alginate, with total fibre diameter as low as 600 μm and core material offset as low as 10% of the total diameter. Furthermore the tuneability of scaffold porosity, pore size and interconnectivity, as well as the preliminary inclusion, compatibility and survival of an L-929 mouse fibroblast cell-line within the scaffolds were explored. This preliminary cell work highlighted the need for optimal material selection and further design reiteration in future research. (paper)

  13. Preparation of hybrid biomaterials for bone tissue engineering

    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.

  14. Review: photopolymerizable and degradable biomaterials for tissue engineering applications.

    Ifkovits, Jamie L; Burdick, Jason A

    2007-10-01

    Photopolymerizable and degradable biomaterials are finding widespread application in the field of tissue engineering for the engineering of tissues such as bone, cartilage, and liver. The spatial and temporal control afforded by photoinitiated polymerizations has allowed for the development of injectable materials that can deliver cells and growth factors, as well as for the fabrication of scaffolding with complex structures. The materials developed for these applications range from entirely synthetic polymers (e.g., poly(ethylene glycol)) to purely natural polymers (e.g., hyaluronic acid) that are modified with photoreactive groups, with degradation based on the hydrolytic or enzymatic degradation of bonds in the polymer backbone or crosslinks. The degradation behavior also ranges from purely bulk to entirely surface degrading, based on the nature of the backbone chemistry and type of degradable units. The mechanical properties of these polymers are primarily based on factors such as the network crosslinking density and polymer concentration. As we better understand biological features necessary to control cellular behavior, smarter materials are being developed that can incorporate and mimic many of these factors. PMID:17658993

  15. New biomaterial as a promising alternative to silicone breast implants.

    Teck Lim, Goy; Valente, Stephanie A; Hart-Spicer, Cherie R; Evancho-Chapman, Mary M; Puskas, Judit E; Horne, Walter I; Schmidt, Steven P

    2013-05-01

    One in eight American women develops breast cancer. Of the many patients requiring mastectomy yearly as a consequence, most elect some form of breast reconstruction. Since 2006, only silicone breast implants have been approved by the FDA for the public use. Unfortunately, over one-third of women with these implants experience complications as a result of tissue-material biocompatibility issues, which may include capsular contracture, calcification, hematoma, necrosis and implant rupture. Our group has been working on developing alternatives to silicone. Linear triblock poly(styrene-b-isobutylene-b-styrene) (SIBS) polymers are self-assembling nanostructured thermoplastic rubbers, already in clinical practice as drug eluting stent coatings. New generations with a branched (arborescent or dendritic) polyisobutylene core show promising potential as a biomaterial alternative to silicone rubber. The purpose of this pre-clinical research was to evaluate the material-tissue interactions of a new arborescent block copolymer (TPE1) in a rabbit implantation model compared to a linear SIBS (SIBSTAR 103T) and silicone rubber. This study is the first to compare the molecular weight and molecular weight distribution, tensile properties and histological evaluation of arborescent SIBS-type materials with silicone rubber before implantation and after explantation. PMID:23466517

  16. Coaxial additive manufacture of biomaterial composite scaffolds for tissue engineering.

    Cornock, R; Beirne, S; Thompson, B; Wallace, G G

    2014-06-01

    An inherent difficulty associated with the application of suitable bioscaffolds for tissue engineering is the incorporation of adequate mechanical characteristics into the materials which recapitulate that of the native tissue, whilst maintaining cell proliferation and nutrient transfer qualities. Biomaterial composites fabricated using rapid prototyping techniques can potentially improve the functionality and patient-specific processing of tissue engineering scaffolds. In this work, a technique for the coaxial melt extrusion printing of core-shell scaffold structures was designed, implemented and assessed with respect to the repeatability, cell efficacy and scaffold porosity obtainable. Encapsulated alginate hydrogel/thermoplastic polycaprolactone (Alg-PCL) cofibre scaffolds were fabricated. Selective laser melting was used to produce a high resolution stainless steel 316 L coaxial extrusion nozzle, exhibiting diameters of 300 μm/900 μm for the inner and outer nozzles respectively. We present coaxial melt extrusion printed scaffolds of Alg-PCL cofibres with ~0.4 volume fraction alginate, with total fibre diameter as low as 600 μm and core material offset as low as 10% of the total diameter. Furthermore the tuneability of scaffold porosity, pore size and interconnectivity, as well as the preliminary inclusion, compatibility and survival of an L-929 mouse fibroblast cell-line within the scaffolds were explored. This preliminary cell work highlighted the need for optimal material selection and further design reiteration in future research. PMID:24658021

  17. Wear and/or corrosion study for biomaterials

    The lifetime extension of prosthetic device, dental materials and orthodontic devices is of major interest for medical international community. In the frame of an interdisciplinary national project, our institute has started to experiment some alternative procedures to evaluate wear/corrosion phenomena of biomaterials by using ion beam based techniques. In the case of metallic components from hip and knee prostheses and dental alloys we present the optimum nuclear reactions according with the main parameters of our U-120 Cyclotron (p, d, Emax = 13 MeV and α particle, Emax = 26 MeV). In the case of polymers, occurring in the joint parts of the prosthetic devices, direct activation causes severe changes in its surface morphology and its structure (formation of defects and free radicals). We have developed an indirect activation method using the principle of recoil ion implantation applied to 56 Co radioactive ions generated by proton particle beams on a Fe target (thickness ≅10μm). The radioactive ions are implanted into the near surface (a few hundred of nanometers). Wear/corrosion rate of the component is observed using tribological testers via the variation of the activity caused by the loss of material. In order to obtain supplementary data concerning radiation influence on polyethylene (PE) samples doses up to 100 kGy were used. Irradiation gamma facility was of an industrial type (SVST-IRASM) authorized for radiation sterilization. (authors)

  18. Binding Quantum Dots to Silk Biomaterials for Optical Sensing

    Disi Lu

    2015-01-01

    Full Text Available Quantum dots (QDs, have great potential for fabricating optical sensing devices and imaging biomaterial degradation in vivo. In the present study, 2-mercaptoethylamine- (MEA- and mercaptopropionic acid- (MPA- capped CdTe-QDs were physically incorporated in silk films that contained a high content (>30% of crystalline beta-sheet structure. The beta-sheets were induced by the addition of glycerol, water annealing, glycerol/annealing, or treatment with methanol. Incorporation of QDs did not influence the formation of beta-sheets. When the films were extracted with water, most QDs remained associated with the silk, based on the retention of photoluminescence in the silk films and negligible photoluminescence in the extracts. Compared to the solution state, photoluminescence intensity significantly decreased for MEA-QDs but not for MPA-QDs in the silk films, while the emission maximum blue shifted (≈4 nm slightly for both. Further film digestion using protease XIV, alpha-chymotrypsin, and the combination of the two proteases suggested that QDs may be bound to the silk beta-sheet regions but not the amorphous regions. QDs photoluminescence in silk films was quenched when the concentration of hydrogen peroxide (H2O2 was above 0.2-0.3 mM, indicating the QDs-incorporated silk films can be used to report oxidation potential in solution.

  19. A Novel Approach for Introducing Bio-Materials Into Cells

    A novel approach was developed to introduce biological materials into cells for gene transfection and gene therapy applications. The method is based on the technique of electrospraying bio-materials into cells. A prototype apparatus was constructed for a feasibility study. The features of the gene transfector include: (1) A dual-capillary assembly to spray suspensions of biological materials. The outer capillary provided sheathing liquid that controlled the charge level on individual particles without altering the properties of suspensions. (2) An air-CO2 gas mixture was used for suppressing possible corona discharge and kept the same gas composition as those in incubators. (3) The designed chamber enabled the spray to operate at reduced pressure for increasing sprayed particle velocity. In the feasibility study, both suspensions of plasmid and plasmid-coated gold particles were used. The plasmid used was the commercially available Enhanced Green Fluorescent Protein gene. COS-1 cells were used as the target and the liquid media was evacuated immediately prior to the spraying process. Electrospraying was conducted at ambient pressure and the duration was no more than 2 min. After the spray transfection, the media was immediately replaced and the cell samples were returned to the incubator for 36 h. Transgene expression was detected by cellular fluorescence. This technology promises to have great potential for gene transfection and therapy studies

  20. Stem cells in skin regeneration: biomaterials and computational models

    Daniele eTartarini

    2016-01-01

    Full Text Available The increased incidence of diabetes and tumors, associated with global demographic issues (aging and life styles, has pointed out the importance to develop new strategies for the effective management of skin wounds. Individuals affected by these diseases are in fact highly exposed to the risk of delayed healing of the injured tissue that typically leads to a pathological inflammatory state and consequently to chronic wounds. Therapies based on stem cells have been proposed for the treatment of these wounds, thanks to the ability of stem cells to self-renew and specifically differentiate in response to the target bimolecular environment. Here we discuss how advanced biomedical devices can be developed by combining stem cells with properly engineered biomaterials and computational models. Examples include composite skin substitutes and bioactive dressings with controlled porosity and surface topography for controlling the infiltration and differentiation of the cells. In this scenario, mathematical frameworks for the simulation of cell population growth can provide support for the design of bio-constructs, reducing the need of expensive, time-consuming and ethically controversial animal experimentation.

  1. Combustion synthesis and photoluminescence study of silicate biomaterials

    V B Bhatkar; N V Bhatkar

    2011-10-01

    Silicate based bioceramics are promising candidates as biomaterials for tissue engineering. The combustion synthesis method provides control on the morphology and particle size of the synthesized material. This paper discusses the combustion synthesis of akermanite (Ca2MgSi2O7 and Sr2MgSi2O7), which has been shown to have good in vitro and in vivo bioactivities by earlier studies. Both Ca2MgSi2O7 and Sr2MgSi2O7 have akermanite structure. Ca2MgSi2O7 and Sr2MgSi2O7 were prepared using urea and ammonium nitrate. The combustion synthesis using urea and ammonium nitrate was found to be cost effective and efficient method of synthesis. The photoluminescence study of Ca2MgSi2O7 : Eu2+ and Sr2MgSi2O7 :Eu2+ shows host specific intense emission of Eu2+.

  2. Fine structure analysis of biocompatible ceramic materials based hydroxyapatite and metallic biomaterials 316L

    The aim of this paper was to obtain and characterize (surface morphology and fine structure) two types of materials: Ca10(PO4)6(OH)2 hydroxyapatite powder (HAp) as biocompatible ceramic materials and AISI 316L austenitic stainless steels as metallic biomaterials, which are the components of the metal–ceramic composites used for medical implants in reconstructive surgery and prosthetic treatment. The HAp was synthesized by coprecipitation method, heat treated at 200 °C, 800 °C and 1200 °C for 4 h, analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The stainless steel 316L type was made by casting, annealing and machined with a low speed (100 mm/s) in order to obtain a smooth surface and after that has been studied from residual stresses point of view in three polishing regimes conditions: at low speed polishing (150 rpm), at high speed polishing (1500 rpm) and high speed-vibration contact polishing (1500 rpm) using wide angle X-ray diffractions (WAXD). The chemical compositions of AISI 316 steel samples were measured using a Foundry Master Spectrometer equipped with CCD detector for spectral lines and the sparking spots of AISI 316L samples were analyzed using SEM. By XRD the phases of HAp powders have been identified and also the degree of crystallinity and average size of crystallites, and with SEM, we studied the morphology of the HAp. It has been found from XRD analysis that we obtained HAp with a high degree of crystallinity at 800 °C and 1200 °C, no presence of impurity and from SEM analysis we noticed the influence of heat treatment on the ceramic particles morphology. From the study of residual stress profiles of 316L samples were observed that it differs substantially for different machining regimes and from the SEM analysis of sparking spots we revealed the rough surfaces of stainless steel rods necessary for a better adhesion of HAp on it.

  3. Engineering the Biomaterial Interface of Prosthetic Vascular Grafts for Improving Thromboresistance and Biocompatibility

    Hoshi, Ryan Akihiro

    The purpose of this dissertation is to develop novel biomaterials as therapies for treating cardiovascular disease. The first and second aims describe the creation of a new and facile approach for grafting bioactive heparin to the surface of expanded polytetrafluoroethylene (ePTFE) vascular grafts using a thermally cross-linked poly(1,8 octanediol-co-citric acid) (POC) elastomer. The POC immobilized heparin (POC-Heparin) demonstrated excellent long term stability under physiological conditions for up to one month and significantly reduced platelet adhesion and maintained bioactive inhibition of whole blood clotting kinetics. POC-Heparin supported endothelial cell viability, proliferation, nitric oxide production and expression of endothelial cell specific markers von Willebrand factor and vascular endothelial-cadherin. This material was also capable of affecting vascular smooth muscle cell phenotype via increased expression of alpha-actin and decreased cell growth. The POC-Heparin coating is capable of significantly improving vascular graft thromboresistance, supporting endothelialization and inhibiting vascular smooth muscle cell growth. This coating technology can be easily adapted to modify other blood contacting devices for simultaneously reducing thrombogenicity and improving endothelialization. Lastly, the third aim details the initial steps for developing materials which are capable of providing sustained release of bioactive signaling molecules such as stromal derived factor-1alpha (SDF-1) to promote recruitment of stem/progenitor cells. A copolymer based on citric acid, polyethylene glycol and N-isopropylacrylamide (CPN) was synthesized with enhanced electronegative charge and gelation properties for controlling SDF-1 protein encapsulation and delivery. Upon CPN gelation at 37°C, SDF-1 protein can be encapsulated with near 100% efficiency and deliver protein for up to 3 weeks. Using isolated blood outgrowth endothelial cells (BOECs) from human peripheral

  4. Siliceous mesostructured cellular foams/ poly(3-hydroxybutyrate-co-3-hydroxyhexanoate composite biomaterials for bone regeneration

    Yang S

    2014-10-01

    Full Text Available Shengbing Yang,1,* Shuogui Xu,2,* Panyu Zhou,2,* Jing Wang,3 Honglue Tan,4 Yang Liu,5 TingTing Tang,4 ChangSheng Liu1,3,5 1The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, People’s Republic of China; 2Changhai Hospital, Department of Orthopedics, the Second Military Medical University, Shanghai, People’s Republic of China; 3Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People’s Republic of China; 4Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine China, Shanghai, People’s Republic of China; 5Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People’s Republic of China *These authors contributed equally to this workAbstract: Osteoinductive and biodegradable composite biomaterials for bone regeneration were prepared by combining poly(3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBHHx with siliceous mesostructured cellular foams (SMC, using the porogen leaching method. Surface hydrophilicity, morphology, and recombinant human bone morphogenetic protein 2 adsorption/release behavior of the SMC/PHBHHx scaffolds were analyzed. Results of scanning electron microscopy indicated that the SMC was uniformly dispersed in the PHBHHx scaffolds, and SMC modification scaffolds have an interconnected porous architecture with pore sizes ranging from 200 to 400 µm. The measurements of the water contact angles suggested that the incorporation of SMC into PHBHHx improves the hydrophilicity of the composite. In vitro studies with simulated body fluid show great improvements to bioactivity and biodegradability versus pure PHBHHx scaffolds. Cell adhesion and cell proliferation on the scaffolds was also evaluated, and the new

  5. Plasma polymerization for cell adhesive/anti-adhesive implant coating

    Meichsner, Juergen; Testrich, Holger; Rebl, Henrike; Nebe, Barbara

    2015-09-01

    Plasma polymerization of ethylenediamine (C2H8N2, EDA) and perfluoropropane (C3F8, PFP) with admixture of argon and hydrogen, respectively, was studied using an asymmetric 13.56 MHz CCP. The analysis of the plasma chemical gas phase processes for stable molecules revealed consecutive reactions: C2H8N2 consumption, intermediate product NH3, and main final product HCN. In C3F8- H2 plasma the precursor molecule C3F8 and molecular hydrogen are consumed and HF as well as CF4 and C2F6 are found as main gaseous reaction products. The deposited plasma polymer films on the powered electrode are strongly cross-linked due to ion bombardment. The stable plasma polymerized films from EDA are characterized by high content of nitrogen with N/C ratio of about 0.35. The plasma polymerized fluorocarbon film exhibit a reduced F/C ratio of about 1.2. Adhesion tests with human osteoblast cell line MG-63 on coated Ti6Al4V samples (polished) compared with uncoated reference sample yielded both, the enhanced cell adhesion for plasma polymerized EDA and significantly reduced cell adhesion for fluorocarbon coating, respectively. Aging of the plasma polymerized EDA film, in particular due to the reactions with oxygen from air, showed no significant change in the cell adhesion. The fluorocarbon coating with low cell adhesion is of interest for temporary implants. Funded by the Campus PlasmaMed.

  6. Innovative Electrostatic Adhesion Technologies

    Bryan, Tom; Macleod, Todd; Gagliano, Larry; Williams, Scott; McCoy, Brian

    2015-01-01

    Developing specialized Electro-Static grippers (commercially used in Semiconductor Manufacturing and in package handling) will allow gentle and secure Capture, Soft Docking, and Handling of a wide variety of materials and shapes (such as upper-stages, satellites, arrays, and possibly asteroids) without requiring physical features or cavities for a pincher or probe or using harpoons or nets. Combined with new rigid boom mechanisms or small agile chaser vehicles, flexible, high speed Electro-Static Grippers can enable compliant capture of spinning objects starting from a safe stand-off distance. Electroadhesion (EA) can enable lightweight, ultra-low-power, compliant attachment in space by using an electrostatic force to adhere similar and dissimilar surfaces. A typical EA enabled device is composed of compliant space-rated materials, such as copper-clad polyimide encapsulated by polymers. Attachment is induced by strong electrostatic forces between any substrate material, such as an exterior satellite panel and a compliant EA gripper pad surface. When alternate positive and negative charges are induced in adjacent planar electrodes in an EA surface, the electric fields set up opposite charges on the substrate and cause an electrostatic adhesion between the electrodes and the induced charges on the substrate. Since the electrodes and the polymer are compliant and can conform to uneven or rough surfaces, the electrodes can remain intimately close to the entire surface, enabling high clamping pressures. Clamping pressures of more than 3 N/cm2 in shear can be achieved on a variety of substrates with ultra-low holding power consumption (measured values are less than 20 microW/Newton weight held). A single EA surface geometry can be used to clamp both dielectric and conductive substrates, with slightly different physical mechanisms. Furthermore EA clamping requires no normal force be placed on the substrate, as conventional docking requires. Internally funded research and

  7. STUDY ON HYDROXYAPATITE COATING ON BIOMATERIALS BY PLASMA SPRAY METHOD

    Dr. Hanumantharaju H. G

    2012-09-01

    Full Text Available In plasma spray coating process the hydroxyapatite powder particles are melted in a high temperature plasma flame and propelled towards the substrate material thus forming a coating. The thin hydroxyapatitecoatings have shown better adhesion to substrates and are more stable in the biological environment because they have more uniform structure and composition. Samples are tested for Scanning Electron Microscopy analysis, to find the uniform coating and bonding strength. From the XRD analysis it was confirmed that the phase purity of HAP is maintained even after the coating.

  8. Effect of Plasma Pretreatments on the Bio-adhesive Functionalized by Biomimetic Catechol Groups to Human Dentin

    Lee, Sangbae; Kim, Kwangmahn; Kim, Kyoungnam

    2012-10-01

    Plasma pretreatments have been introduced for modifying the surface chemistry of biomaterials. In an effort to improve the strength of the human dentin/bio-adhesive joint, oxygen plasma pretreatments to the bio-adhesive were investigated. Plasma treatments were carried out using custom-built and low pressure. Dentin were treated with plasma and used to prepare lap shear tests. Bio-adhesives were prepared synthesizing dopamine methacrylamide (DMA) monomer. DMA were copolymerized with 2-methoxyethylacrylate (MEA) by free radical polymerization. Proton nuclear magnetic resonance (^1H-NMR) and Gel permeation chromatography (GPC) analysis on samples of synthesized p(DMA-co-MEA) was performed to confirm that the resulting materials had the desired chemical structure. The effects of plasma pretreatments on surface chemistry were studied using Fourier transform infrared analysis (FTIR), and contact angle measurements. Oxygen plasma pretreatments enhanced adhesive strength by oxidizing of the catechol residue and creating a cross-linking as compared with control group. Furthermore plasma pretreatments lead to increase hydrophilicity of copolymers. Prospectively, the great potential of advanced technology in creation of the ``Plasma pretreatment to the DOPA adhesives'' would lead to the development of versatile method for coating to medial devices as well as dentin bonding.

  9. Elastocapilllarity in insect adhesion: the case of beetle adhesive hair

    Gernay, Sophie; Gilet, Tristan; Lambert, Pierre; Federle, Walter

    2014-11-01

    The feet of many insects are covered with dense arrays of hair-like structures called setae. Liquid capillary bridges at the tip of these micrometric structures are responsible for the controlled adhesion of the insect on a large variety of substrates. The resulting adhesion force can exceed several times the body weight of the insect. The high aspect-ratio of setae suggests that flexibility is a key ingredient in this capillary-based adhesion mechanism. There is indeed a strong coupling between their elastic deformation and the shape of the liquid meniscus. In this experimental work, we observe and quantify the local deflection of dock beetle seta tips under perpendicular loading using interference microscopy. Our results are then interpreted in the light of an analytic model of elastocapillarity. This research has been funded by the FRIA/FNRS and the Interuniversity Attraction Poles Programme (IAP 7/38 MicroMAST) initiated by the Belgian Science Policy Office.

  10. Biological and mechanical implications of PEGylating proteins into hydrogel biomaterials.

    Gonen-Wadmany, Maya; Goldshmid, Revital; Seliktar, Dror

    2011-09-01

    Protein PEGylation has been successfully applied in pharmaceuticals and more recently in biomaterials development for making bioactive and structurally versatile hydrogels. Despite many advantages in this regard, PEGylation of proteins is also known to alter biological activity and modify biophysical characteristics in ways that may be detrimental to cells. The aim of this study was to evaluate the relative loss of biological compatibility associated with PEGylating a fibrinogen precursor into a hydrogel scaffold, in comparison to thrombin cross-linked fibrin hydrogels. Specifically, we investigated the consequences of conjugating fibrinogen with linear polyethtylene glycol (PEG) polymer chains (10 kDa) on the ability to cultivate neonatal human foreskin fibroblasts (HFFs) in 3-D. For this purpose, thrombin cross-linked fibrin (TCL-Fib) and PEGylated fibrinogen (PEG-Fib) gels were prepared with HFFs and cultured for up to seven days. The benchmark biological compatibility test was based on a combined assessment of cellular morphology, proliferation, actin expression, and matrix metalloproteinase (MMP) expression in the 3-D culture systems. The results showed correlations between modulus and proteolytic biodegradation in both materials, but no correlation between the mechanical properties and the ability of HFFs to remodel the microenvironment. A slight reduction of actin, MMPs, and spindled morphology of the cells in the PEG-Fib hydrogels indicated that the PEGylation process altered the biological compatibility of the fibrin. Nevertheless, the overall benchmark performance of the two materials demonstrated that PEGylated fibrinogen hydrogels still retains much to the inherent biofunctionality of the fibrin precursor when used as a scaffold for 3-D cell cultivation. PMID:21669457

  11. Measurements of optical polarization properties in dental tissues and biomaterials

    Fernández-Oliveras, Alicia; Pecho, Oscar E.; Rubiño, Manuel; Pérez, María M.

    2011-05-01

    Since biological tissues can have the intrinsic property of altering the polarization of incident light, optical polarization studies are important for a complete characterization. We have measured the polarized light scattered off of different dental tissues and biomaterials for a comparative study of their optical polarization property. The experimental setup was composed by a He-Ne laser, two linear polarizers and a detection system based on a photodiode. The laser beam was passed through one linear polarizer placed in front of the sample, beyond which the second linear polarizer (analyzer) and the photodiode detector were placed. First, the maximum laser-light intensity (reference condition) was attained without the sample in the laser path. Then, the sample was placed between the two polarizers and the polarization shift of the scattered laser light was determined by rotating the analyzer until the reference condition was reached. Two dental-resin composites (nanocomposite and hybrid) and two human dental tissues (enamel and dentine) were analyzed under repeatability conditions at three different locations on the sample: 20 measurements of the shift were taken and the average value and the uncertainty associated were calculated. For the human dentine the average value of the polarization shift found was 7 degrees, with an associated uncertainty of 2 degrees. For the human enamel and both dental-resin composites the average shift values were found to be similar to their corresponding uncertainties (2 degrees). The results suggest that although human dentine has notable polarization properties, dental-resin composites and human enamel do not show significant polarization shifts.

  12. A novel blood incubation system for the in-vitro assessment of interactions between platelets and biomaterial surfaces under dynamic flow conditions: The Hemocoater.

    Boudot, Cécile; Boccoz, Ana; Düregger, Katharina; Kuhnla, Ariane

    2016-10-01

    Hemocompatibility evaluation of biomaterials necessitates the use of blood incubation systems which simulate physiological flow conditions. However, most of the current systems have various limitations, especially restricted material variability, poor access to the test surface or damage of blood cells due to the use of a pump. In this paper, we combined the advantages of existent setups and developed a new planar shaped incubation test bench to lift those restrictions and mimic the pulsatile in-vivo situation. The adjustable flow conditions at the tested material surface were defined and corresponded to those in blood vessels. Platelet/material-interaction, as major aspect of hemocompatibility, was investigated for four common polymeric materials (polyoxymethylene, polypropylene, polyethylene and silicone elastomer) with platelet deprivation and platelet adhesion tests. Highly significant differences in the adhesion of platelets onto the tested material surfaces were measured. The number of adhered platelets on the most hydrophobic sample (silicone elastomer) was four-times higher than on the most hydrophilic sample (polyoxymethylene). These findings were confirmed with a scanning microscopic analysis and demonstrated the suitability of the testing device for the evaluation of platelet/material interactions. Moreover, hemolysis measurements demonstrated that the system did not provoke blood damage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2430-2440, 2016. PMID:27213915

  13. Assessment of angiogenic properties of biomaterials using the chicken embryo chorioallantoic membrane assay

    The angiogenic potential of a biomaterial is a critical factor for successful graft intake in tissue engineering. We developed a modified, rapid and reproducible chicken embryo chorioallantoic membrane (CAM) assay to evaluate the ability of biomaterials in inducing blood vessel density. Five biomaterials including one-layer porcine small intestinal submucosa (SIS), two-layer SIS, four-layer vacuum pressed (VP) SIS, polyglycolic acid (PGA) and PGA modified with poly(lactic-co-glycolic acid) (PLGA) were analyzed. A circular section (1.2 mm diameter) of each biomaterial was placed near a group of blood vessels in the CAM. Blood vessels around the biomaterials were captured with black and white images at 96 h post implantation; and the images were subjected to densitometry evaluation. One-layer SIS induced a significant increase in blood vessel density as compared to the cellulose nitrate negative control, and had the greatest increase in blood vessel density as compared to four-layer VP SIS, PGA, or PLGA modified PGA. Although two-layer SIS has enhanced physical structure for surgical manipulation, its induction in blood vessel density was significantly lower than the one-layer SIS. Stripping the SIS proteins or incubating one-layer SIS with neutralizing antibodies against basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) resulted in decreased angiogenesis. Consistent with results obtained from bladder augmentation animal models, these results confirmed that angiogenic growth factors were present in SIS and affected the angiogenic potential of biomaterials. These data also demonstrated that the CAM assay can be used to ascertain methodically the angiogenic potential of biomaterials

  14. Lignin-Furfural Based Adhesives

    Prajakta Dongre

    2015-07-01

    Full Text Available Lignin recovered from the hot-water extract of sugar maple (Acer saccharum is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC. The effect of pH (0.3, 0.65 and 1, ex situ furfural, and curing conditions on the tensile properties of adhesive reinforced glass fibers is determined and compared to the reinforcement level of commercially available PF resin. The adhesive blend prepared at pH = 0.65 with no added furfural exhibits the highest tensile properties and meets 90% of the PF tensile strength.

  15. Advanced biomaterials and their potential applications in the treatment of periodontal disease.

    Chen, Xi; Wu, Guofeng; Feng, Zhihong; Dong, Yan; Zhou, Wei; Li, Bei; Bai, Shizhu; Zhao, Yimin

    2016-08-01

    Periodontal disease is considered as a widespread infectious disease and the most common cause of tooth loss in adults. Attempts for developing periodontal disease treatment strategies, including drug delivery and regeneration approaches, provide a useful experimental model for the evaluation of future periodontal therapies. Recently, emerging advanced biomaterials including hydrogels, films, micro/nanofibers and particles, hold great potential to be utilized as cell/drug carriers for local drug delivery and biomimetic scaffolds for future regeneration therapies. In this review, first, we describe the pathogenesis of periodontal disease, including plaque formation, immune response and inflammatory reactions caused by bacteria. Second, periodontal therapy and an overview of current biomaterials in periodontal regenerative medicine have been discussed. Third, the roles of state-of-the-art biomaterials, including hydrogels, films, micro/nanofibers and micro/nanoparticles, developed for periodontal disease treatment and periodontal tissue regeneration, and their fabrication methods, have been presented. Finally, biological properties, including biocompatibility, biodegradability and immunogenicity of the biomaterials, together with their current applications strategies are given. Conclusive remarks and future perspectives for such advanced biomaterials are discussed. PMID:26004052

  16. Engineered Biomaterials to Enhance Stem Cell-Based Cardiac Tissue Engineering and Therapy.

    Hasan, Anwarul; Waters, Renae; Roula, Boustany; Dana, Rahbani; Yara, Seif; Alexandre, Toubia; Paul, Arghya

    2016-07-01

    Cardiovascular disease is a leading cause of death worldwide. Since adult cardiac cells are limited in their proliferation, cardiac tissue with dead or damaged cardiac cells downstream of the occluded vessel does not regenerate after myocardial infarction. The cardiac tissue is then replaced with nonfunctional fibrotic scar tissue rather than new cardiac cells, which leaves the heart weak. The limited proliferation ability of host cardiac cells has motivated investigators to research the potential cardiac regenerative ability of stem cells. Considerable progress has been made in this endeavor. However, the optimum type of stem cells along with the most suitable matrix-material and cellular microenvironmental cues are yet to be identified or agreed upon. This review presents an overview of various types of biofunctional materials and biomaterial matrices, which in combination with stem cells, have shown promises for cardiac tissue replacement and reinforcement. Engineered biomaterials also have applications in cardiac tissue engineering, in which tissue constructs are developed in vitro by combining stem cells and biomaterial scaffolds for drug screening or eventual implantation. This review highlights the benefits of using biomaterials in conjunction with stem cells to repair damaged myocardium and give a brief description of the properties of these biomaterials that make them such valuable tools to the field. PMID:26953627

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

    Ye Li

    2015-07-01

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

  18. Elasticity, biodegradability and cell adhesive properties of chitosan/hyaluronan multilayer films

    Schneider, Aurore; Richert, Ludovic; Francius, Gregory; Voegel, Jean-Claude; Picart, Catherine [Present address: Universite de Montpellier II, CNRS-UMR 5539, cc107, Place Eugene Bataillon, 34 095 Montpellier Cedex 5 (France)

    2007-03-01

    In the bioengineering field, a recent and promising approach to modifying biomaterial surfaces is the layer-by-layer (LbL) technique used to build thin polyelectrolyte multilayer films. In this work, we focused on polyelectrolyte multilayer films made of two polysaccharides, chitosan (CHI) and hyaluronan (HA), and on the control of their physico-chemical and cell adhesive properties by chemical cross-linking. CHI/HA films were cross-linked using a water soluble carbodiimide and observed by confocal laser scanning microscopy (CLSM) with a fluorescently labeled CHI. Film thicknesses were similar for native and cross-linked films. The film nanometer roughness was measured by atomic force microscopy and was found to be higher for cross-linked films. Cross-linking the films also leads to a drastic change in film stiffness. The elastic modulus of the films (Young's modulus) as measured by AFM nano-indentation was about tenfold increased for cross-linked films as compared to native ones. From a biological point of view, cross-liked films are more resistant to enzymatic degradation by hyaluronidase. Furthermore, the increase in film stiffness has a favorable effect on the adhesion and spreading of chondrosarcoma cells. Thus, the CHI/HA cross-linked films could be used for various applications due to their adhesive properties and to their mechanical properties (including stability in enzymatic media)

  19. Elasticity, biodegradability and cell adhesive properties of chitosan/hyaluronan multilayer films

    Schneider, Aurore; Richert, Ludovic; Francius, Gregory; Voegel, Jean-Claude; Picart, Catherine

    2007-03-01

    In the bioengineering field, a recent and promising approach to modifying biomaterial surfaces is the layer-by-layer (LbL) technique used to build thin polyelectrolyte multilayer films. In this work, we focused on polyelectrolyte multilayer films made of two polysaccharides, chitosan (CHI) and hyaluronan (HA), and on the control of their physico-chemical and cell adhesive properties by chemical cross-linking. CHI/HA films were cross-linked using a water soluble carbodiimide and observed by confocal laser scanning microscopy (CLSM) with a fluorescently labeled CHI. Film thicknesses were similar for native and cross-linked films. The film nanometer roughness was measured by atomic force microscopy and was found to be higher for cross-linked films. Cross-linking the films also leads to a drastic change in film stiffness. The elastic modulus of the films (Young's modulus) as measured by AFM nano-indentation was about tenfold increased for cross-linked films as compared to native ones. From a biological point of view, cross-liked films are more resistant to enzymatic degradation by hyaluronidase. Furthermore, the increase in film stiffness has a favorable effect on the adhesion and spreading of chondrosarcoma cells. Thus, the CHI/HA cross-linked films could be used for various applications due to their adhesive properties and to their mechanical properties (including stability in enzymatic media).

  20. Tailoring Novel PTFE Surface Properties: Promoting Cell Adhesion and Antifouling Properties via a Wet Chemical Approach.

    Gabriel, Matthias; Niederer, Kerstin; Becker, Marc; Raynaud, Christophe Michel; Vahl, Christian-Friedrich; Frey, Holger

    2016-05-18

    Many biomaterials used for tissue engineering applications lack cell-adhesiveness and, in addition, are prone to nonspecific adsorption of proteins. This is especially important for blood-contacting devices such as vascular grafts and valves where appropriate surface properties should inhibit the initial attachment of platelets and promote endothelial cell colonization. As a consequence, the long-term outcome of the implants would be improved and the need for anticoagulation therapy could be reduced or even abolished. Polytetrafluoroethylene (PTFE), a frequently used polymer for various medical applications, was wet-chemically activated and subsequently modified by grafting the endothelial cell (EC) specific peptide arginine-glutamic acid-aspartic acid-valine (REDV) using a bifunctional polyethylene glycol (PEG)-spacer (known to reduce platelet and nonspecific protein adhesion). Modified and control surfaces were both evaluated in terms of EC adhesion, colonization, and the attachment of platelets. In addition, samples underwent bacterial challenges. The results strongly suggested that PEG-mediated peptide immobilization renders PTFE an excellent substrate for cellular growth while simultaneously endowing the material with antifouling properties. PMID:27041509

  1. Wet Chemistry and Peptide Immobilization on Polytetrafluoroethylene for Improved Cell-adhesion.

    Gabriel, Matthias; Niederer, Kerstin; Frey, Holger

    2016-01-01

    Endowing materials surface with cell-adhesive properties is a common strategy in biomaterial research and tissue engineering. This is particularly interesting for already approved polymers that have a long standing use in medicine because these materials are well characterized and legal issues associated with the introduction of newly synthesized polymers may be avoided. Polytetrafluoroethylene (PTFE) is one of the most frequently employed materials for the manufacturing of vascular grafts but the polymer lacks cell adhesion promoting features. Endothelialization, i.e., complete coverage of the grafts inner surface with a confluent layer of endothelial cells is regarded key to optimal performance, mainly by reducing thrombogenicity of the artificial interface. This study investigates the growth of endothelial cells on peptide-modified PTFE and compares these results to those obtained on unmodified substrate. Coupling with the endothelial cell adhesive peptide Arg-Glu-Asp-Val (REDV) is performed via activation of the fluorin-containing polymer using the reagent sodium naphthalenide, followed by subsequent conjugation steps. Cell culture is accomplished using Human Umbilical Vein Endothelial Cells (HUVECs) and excellent cellular growth on peptide-immobilized material is demonstrated over a two-week period. PMID:27584937

  2. Computational Chemistry of Adhesive Bonds

    Phillips, Donald H.

    1999-01-01

    This investigation is intended to determine the electrical mechanical, and chemical properties of adhesive bonds at the molecular level. The initial determinations will be followed by investigations of the effects of environmental effects on the chemistry and properties of the bond layer.

  3. Adhesion of biocompatible and biodegradable micropatterned surfaces

    Kaiser, J.S.; Kamperman, M.M.G.; Souza, E.J.; Schick, B.; Arzt, E.

    2011-01-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PL

  4. Polymer biomaterial constructs for regenerative medicine and functional biological systems

    Meng, Linghui

    The use of collagen as a biomaterial is currently undergoing a renaissance in the tissue engineering field. The excellent biocompatibility and safety due to its biological characteristics, such as biodegradability and weak antigenicity, make collagen a primary material resource in medical applications. Described herein is work towards the development of novel collagen-based matrices, with additional multi-functionality imparted through a novel in-situ crosslinking approach. The process of electrospinning has become a widely used technique for the creation of fibrous scaffolds for tissue engineering applications due to its ability to rapidly create structures composed of nano-scale polymer fibers closely resembling the architecture of the extracellular matrix (ECM). Collagen-PCL sheath-core bicomponent fibrous scaffolds were fabricated using a novel variation on traditional electrospinning, known as co-axial electrospinning. The results showed that the addition of a synthetic polymer core into collagen nanofibers remarkably increased the mechanical strength of collagen matrices spun from the benign solvent system. A novel single-step, in-situ collagen crosslink approach was developed in order to solve the problems dominating traditional collagen crosslinking methods, such as dimensional shrinking and loss of porous morphology, and to simplify the crosslinking procedure for electrospun collagen scaffolds. The excess amount of NHS present in the crosslinking mixture was found to delay the EDC/collagen coupling reaction in a controlled fashion. Fundamental investigations into the development and characterization of in-situ crosslinked collagen matrices such as fibrous scaffolds, gels and sponges, as well as their biomedical applications including cell culture substrates, wound dressings, drug delivery matrices and bone regeneration substitutes, were performed. The preliminary mice studies indicated that the in-situ crosslinked collagen matrices could be good candidates

  5. Second harmonic generation (SHG) and two-photon fluorescence (TPF) contrast imaging in biomaterial analysis

    Lang, Xuye; Lyubovitsky, Julia

    2015-07-01

    Collagen hydrogels are natural biomaterials that comprise 3D networks of high water content and have viscoelastic properties and biocompatibility similar to native tissues. Consequently, these materials play an important role in tissue engineering and regenerative medicine for quite some time. Second harmonic generation (SHG) and two-photon fluorescence (TPF) contrasts transpire as valuable label-free spectroscopic probes for analysis of these biomaterials and this presentation will report the structural, mechanical and physicochemical parameters leading to the observed optical SHG and TPF effects in synthesized 3D collagen hydrogels. We will present results regarding understanding the dependency of collagen fiber formation on ion types, new results regarding strengthening of these biomaterials with a nontoxic chemical cross-linker genipin and polarization selection of collagen fibers' orientations.

  6. Micro- and Nanoengineering Approaches to Control Stem Cell-Biomaterial Interactions

    Ali Khademhosseini

    2011-06-01

    Full Text Available As our population ages, there is a greater need for a suitable supply of engineered tissues to address a range of debilitating ailments. Stem cell based therapies are envisioned to meet this emerging need. Despite significant progress in controlling stem cell differentiation, it is still difficult to engineer human tissue constructs for transplantation. Recent advances in micro- and nanofabrication techniques have enabled the design of more biomimetic biomaterials that may be used to direct the fate of stem cells. These biomaterials could have a significant impact on the next generation of stem cell based therapies. Here, we highlight the recent progress made by micro- and nanoengineering techniques in the biomaterials field in the context of directing stem cell differentiation. Particular attention is given to the effect of surface topography, chemistry, mechanics and micro- and nanopatterns on the differentiation of embryonic, mesenchymal and neural stem cells.

  7. Models for the histologic study of the skin interface with percutaneous biomaterials

    Percutaneous devices are critical for health care. Access to tissue, vessels and internal organs afforded by these devices provides the means to treat and monitor many diseases. Unfortunately, such access is not restricted, and infection may compromise the usefulness of the device and even the life of the patient. New biomaterials offer the possibility of maintaining internal access while limiting microbial access, but understanding of the cutaneous/biomaterial interface and models to study this area are limited. This paper focuses on models useful for studying the morphology and biology of the intersection of skin and percutaneous biomaterials. An organ culture and a mouse model are described that offer promising possibilities for improved understanding of this critical interface

  8. Advanced biomaterials for repairing the nervous system: what can hydrogels do for the brain?

    Zin Z. Khaing

    2014-09-01

    Full Text Available Newly developed hydrogels are likely to play significant roles in future therapeutic strategies for the nervous system. In this review, unique features of the central nervous system (i.e., the brain and spinal cord that are important to consider in developing engineered biomaterials for therapeutic applications are discussed. This review focuses on recent findings in hydrogels as biomaterials for use as (1 drug delivery devices, specifically focusing on how the material can change the delivery rate of small molecules, (2 scaffolds that can modify the post-injury environment, including preformed and injectable scaffolds, (3 cell delivery vehicles, discussing cellular response to natural and synthetic polymers as well as structured and amorphous materials, and (4 scaffolds for tissue regeneration, describing micro- and macro-architectural constructs that have been designed for neural applications. In addition, key features in each category that are likely to contribute to the translational success of these biomaterials are highlighted.

  9. Innovative Biomaterials Based on Collagen-Hydroxyapatite and Doxycycline for Bone Regeneration

    Narcisa Mederle

    2016-01-01

    Full Text Available Bone regeneration is a serious challenge in orthopedic applications because of bone infections increase, tumor developing, and bone loss due to trauma. In this context, the aim of our study was to develop innovative biomaterials based on collagen and hydroxyapatite (25, 50, and 75% which mimic bone composition and prevent or treat infections due to doxycycline content. The biomaterials were obtained by freeze-drying in spongious forms and were characterized by water uptake capacity and microscopy. The in vitro release of doxycycline was also determined and established by non-Fickian drug transport mechanism. Among the studied biomaterials, the most suitable one to easily deliver the drug and mimic bone structure, having compact structure and lower capacity to uptake water, was the one with 75% hydroxyapatite and being cross-linked.

  10. Film adhesion in amorphous silicon solar cells

    A R M Yusoff; M N Syahrul; K Henkel

    2007-08-01

    A major issue encountered during fabrication of triple junction -Si solar cells on polyimide substrates is the adhesion of the solar cell thin films to the substrates. Here, we present our study of film adhesion in amorphous silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and Gouldflex), and the effect of tie coats on film adhesion.

  11. Nonwoven glass fiber mat reinforces polyurethane adhesive

    Roseland, L. M.

    1967-01-01

    Nonwoven glass fiber mat reinforces the adhesive properties of a polyurethane adhesive that fastens hardware to exterior surfaces of aluminum tanks. The mat is embedded in the uncured adhesive. It ensures good control of the bond line and increases the peel strength.

  12. Desenvolvimento de biomaterial a partior de matriz amniótica humana

    Francisco, Júlio César

    2013-01-01

    Resumo: A membrana amniótica tem sido estudada como possível biomaterial na Medicina Regenerativa, sobretudo de uso externo. Os protocolos são controversos entre os métodos descelularização e manutenção da integridade de seus componentes. Objetivo: desenvolver um biomaterial a partir de matriz amniótica humana. Material e Métodos: Realizado protocolo modificado de placenta humana a base detergentes iônicos para remoção de todos os componentes celulares da membrana amniótica. Placentas obtidas...

  13. Application of the INAA technique for elemental analysis of metallic biomaterials used in dentistry

    Cincu, Em [' Horia Hulubei' National Institute for Research and Development in Physics and Nuclear Engineering (IFIN-HH), Bucharest-Magurele, 407 Atomistilor Street, P. O. Box MG-6, Bucharest 077125 (Romania)], E-mail: cincue@nipne.ro; Craciun, L.; Manea-Grigore, Ioana; Cazan, I.L.; Manu, V. [' Horia Hulubei' National Institute for Research and Development in Physics and Nuclear Engineering (IFIN-HH), Bucharest-Magurele, 407 Atomistilor Street, P. O. Box MG-6, Bucharest 077125 (Romania); Barbos, D. [Institute for Nuclear Research (INR) Mioveni, 1Campului Street, P. O. Box 78, Bucharest 115400 (Romania); Cocis, A. [Dental Surgery Clinic PANA-DANIELA, Bucharest, 6 Intrarea Buzesti Street (Romania)

    2009-12-15

    The sensitive nuclear analytical technique Instrumental Neutron Activation Analysis (INAA) has been applied on several types of metallic biomaterials (Heraenium CE, Ventura Nibon, Wiron 99 and Ducinox which are currently used for restoration in the dental clinics) to study its performance in elemental analysis and identify eventual limitations. The investigation has been performed by two NAA Laboratories and aimed at getting an answer to the question on how the biomaterials compositions influence the patients' health over the course of time, taking into account the EC Directive 94/27/EC recommendations concerning Ni toxicity.

  14. Preparation and Properties of Collagen-Chitosan/ Glycosaminoglycans as Candidate Tissue Engineering Biomaterials

    LIQin-Hua; HUANGYao-xiong; CHENGJian-su

    2004-01-01

    A novel biomaterial scaffold was created from collagen-chitosan/GAG. Its tensile strength was 8.6MPa(wet state)and degree of swelling water was 60%~75% with higer ultimate elongation 300%. Rabbit corneas of collagen-chitosan/GAG implantation samples in vivo for biodegradation showed that the inplantion samples was complets biodegrable and digested afere 120 day. There was enought time to maintain cell growth,immigrating and proliferation. This biomaterials scaffold can be used for cell culture and in various tissue engineering fields.

  15. Mechanical strength of adhesive-bonding

    In order to meet the prospective application of a GFRP dewar for energy storage system using a large superconducting magnet, the dewar with a complex structure together with a large size are desired to be made. It is difficult to manufacture such a type of the dewars in one united body. These dewars can be manufactured by the adhesive-bonding method. In the present study, the mechanical strength of adhesive-bonding is studied from this point of view. The mechanical strength of the adhesive-bonding has been investigated by the static tensile method and the impact loading method using small test samples. From the static tensile tests, the following results have been obtained. For the sample adhesive-bonded with insertion structure, the mechanical strength of the adhesive-bonding is found to depend on the adhesives used and on the difference of the thermal contraction between the materials which are adhesive-bonded each other. Using a soft adhesive as Araldite 106, the mechanical strength of the adhesive-bonding is small at room temperature, but it remarkably increases at cryogenic temperatures. For a hard adhesive as Araldite 103 and Stycast 2850 FT, it is large at room temperature, and it further increases at cryogenic temperatures. The dewar has to be strong enough not only at cryogenic temperatures but also at room temperature. A soft adhesive is not suitable for constructing the dewar. For the sample adhesive-bonded with screwing structure, the mechanical strength of the adhesive-bonding depends on the shear strength of GFRP itself. The mechanical strength of the adhesive-bonded part increases with the decreasing temperature. Therefore, this screwing method is advantageous for the construction of the dewar. According to the impact loading tests, it is found that the adhesive-bonding of screwing structure is not brittle at cryogenic temperature. This is due to inherent property of GFRP. (J.P.N.)

  16. DMPD: The interrelated role of fibronectin and interleukin-1 in biomaterial-modulatedmacrophage function. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 16978691 The interrelated role of fibronectin and interleukin-1 in biomaterial-modu...(.svg) (.html) (.csml) Show The interrelated role of fibronectin and interleukin-1 in biomaterial-modulatedm...acrophage function. PubmedID 16978691 Title The interrelated role of fibronectin

  17. Injectable biomaterials for the treatment of stress urinary incontinence: their potential and pitfalls as urethral bulking agents.

    Davis, Niall F

    2013-06-01

    Injectable urethral bulking agents composed of synthetic and biological biomaterials are minimally invasive treatment options for stress urinary incontinence (SUI). The development of an ideal urethral bulking agent remains challenging because of clinical concerns over biocompatibility and durability. Herein, the mechanical and biological features of injectable urethral biomaterials are investigated, with particular emphasis on their future potential as primary and secondary treatment options for SUI. A literature search for English language publications using the two online databases was performed. Keywords included "stress urinary incontinence", "urethral bulking agent" and "injectable biomaterial". A total of 98 articles were analysed, of which 45 were suitable for review based on clinical relevance and importance of content. Injectable biomaterials are associated with a lower cure rate and fewer postoperative complications than open surgery for SUI. They are frequently reserved as secondary treatment options for patients unwilling or medically unfit to undergo surgery. Glutaraldehyde cross-linked bovine collagen remains the most commonly injected biomaterial and has a cure rate of up to 53 %. Important clinical features of an injectable biomaterial are durability, biocompatibility and ease of administration, but achieving these requirements is challenging. In carefully selected patients, injectable biomaterials are feasible alternatives to open surgical procedures as primary and secondary treatment options for SUI. In future, higher cure rates may be feasible as researchers investigate alternative biomaterials and more targeted injection techniques for treating SUI.

  18. Patterned neuronal networks using nanodiamonds and the effect of varying nanodiamond properties on neuronal adhesion and outgrowth

    Edgington, R. J.; Thalhammer, A.; Welch, J. O.; Bongrain, A.; Bergonzo, P.; Scorsone, E.; Jackman, R. B.; Schoepfer, R.

    2013-10-01

    Objective. Detonation nanodiamond monolayer coatings are exceptionally biocompatible substrates for in vitro cell culture. However, the ability of nanodiamond coatings of different origin, size, surface chemistry and morphology to promote neuronal adhesion, and the ability to pattern neurons with nanodiamonds have yet to be investigated. Approach. Various nanodiamond coatings of different type are investigated for their ability to promote neuronal adhesion with respect to surface coating parameters and neurite extension. Nanodiamond tracks are patterned using photolithography and reactive ion etching. Main results. Universal promotion of neuronal adhesion is observed on all coatings tested and analysis shows surface roughness to not be a sufficient metric to describe biocompatibility, but instead nanoparticle size and curvature shows a significant correlation with neurite extension. Furthermore, neuronal patterning is achieved with high contrast using patterned nanodiamond coatings down to at least 10 µm. Significance. The results of nanoparticle size and curvature being influential upon neuronal adhesion has great implications towards biomaterial design, and the ability to pattern neurons using nanodiamond tracks shows great promise for applications both in vitro and in vivo.

  19. Steric Interference of Adhesion Supports In-Vitro Chondrogenesis of Mesenchymal Stem Cells on Hydrogels for Cartilage Repair

    Goldshmid, Revital; Cohen, Shlomit; Shachaf, Yonatan; Kupershmit, Ilana; Sarig-Nadir, Offra; Seliktar, Dror; Wechsler, Roni

    2015-01-01

    Recent studies suggest the presence of cell adhesion motifs found in structural proteins can inhibit chondrogenesis. In this context, the current study aims to determine if a polyethylene glycol (PEG)-modified fibrinogen matrix could support better chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSC) based on steric interference of adhesion, when compared to a natural fibrin matrix. Hydrogels used as substrates for two-dimensional (2D) BM-MSC cultures under chondrogenic conditions were made from cross-linked PEG-fibrinogen (PF) and compared to thrombin-activated fibrin. Cell morphology, protein expression, DNA and sulfated proteoglycan (GAG) content were correlated to substrate properties such as stiffness and adhesiveness. Cell aggregation and chondrogenic markers, including collagen II and aggrecan, were observed on all PF substrates but not on fibrin. Shielding fibrinogen’s adhesion domains and increasing stiffness of the material are likely contributing factors that cause the BM-MSCs to display a more chondrogenic phenotype. One composition of PF corresponding to GelrinC™—a product cleared in the EU for cartilage repair—was found to be optimal for supporting chondrogenic differentiation of BM-MSC while minimizing hypertrophy (collagen X). These findings suggest that semi-synthetic biomaterials based on ECM proteins can be designed to favourably affect BM-MSC towards repair processes involving chondrogenesis. PMID:26411496

  20. Hydrophilic surface modification of acrylate-based biomaterials.

    Arnal-Pastor, M; Comín-Cebrián, S; Martínez-Ramos, C; Monleón Pradas, M; Vallés-Lluch, A

    2016-04-01

    Acrylic polymers have proved to be excellent with regard to cell adhesion, colonization and survival, in vitro and in vivo. Highly ordered and regular pore structures thereof can be produced with the help of polyamide templates, which are removed with nitric acid. This treatment converts a fraction of the ethyl acrylate side groups into acrylic acid, turning poly(ethyl acrylate) scaffolds into a more hydrophilic and pH-sensitive substrate, while its good biological performance remains intact. To quantify the extent of such a modification, and be able to characterize the degree of hydrophilicity of poly(ethyl acrylate), poly(ethyl acrylate) was treated with acid for different times (four, nine and 17 days), and compared with poly(acrylic acid) and a 90/10%wt. EA/AAc copolymer (P(EA-co-AAc)). The biological performance was also assessed for samples immersed in acid up to four days and the copolymer, and it was found that the incorporation of acidic units on the material surface was not prejudicial for cells. This surface modification of 3D porous hydrophobic scaffolds makes easier the wetting with culture medium and aqueous solutions in general, and thus represents an advantage in the manageability of the scaffolds. PMID:26767395

  1. Biomaterials for orthopedics: a roughness analysis by atomic force microscopy.

    Covani, Ugo; Giacomelli, Luca; Krajewski, Adriano; Ravaglioli, Antonio; Spotorno, Lorenza; Loria, Patrizia; Das, Saradindu; Nicolini, Claudio

    2007-09-01

    We conducted an AFM analysis of roughness on 7 materials widely used in bone reconstruction. Roughness was evaluated by measuring Root Mean Square (RMS) values and RMS/average height (AH) ratio, in different dimensional ranges, varying from 100 microns square to a few hundreds of nanometers. The results showed that Titanium presented a lower roughness than the other materials analyzed, frequently reaching statistical significance. On the contrary, bioactive materials, such as hydroxyapatite (HA) and bioactive glasses, demonstrated an overall higher roughness. In particular, this study focuses attention on AP40 and especially RKKP, which proved to have a significant higher roughness at low dimensional ranges. This determines a large increase in surface area, which is strongly connected with osteoblast adhesion and growth and to protein absorption. Therefore, the biointegration properties of bioactive glasses can also be given as answer in terms of surface structures in which chemical composition can influence directly the biological system (e.g. with chemical exchanges and development of specific surface electrical charge) and indirectly, via the properties induced on tribological behavior that expresses itself during the smoothing of the surfaces. We also test two new bioactive glasses, RBP1 and RBP2, with a chemical composition similar to AP40, but with some significant small additions and substitutions of components, in order to make preliminary considerations on their potential role in orthopedics. PMID:17326227

  2. Gecko adhesion pad: a smart surface?

    Pesika, Noshir S.; Zeng, Hongbo; Kristiansen, Kai; Zhao, Boxin; Tian, Yu; Autumn, Kellar; Israelachvili, Jacob

    2009-11-01

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  3. Gecko adhesion pad: a smart surface?

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  4. Gecko adhesion pad: a smart surface?

    Pesika, Noshir S [Chemical and Biomolecular Engineering Department, Tulane University, New Orleans, LA 70118 (United States); Zeng Hongbo [Chemical and Materials Engineering Department, University of Alberta, Edmonton, AB, T6G 2V4 (Canada); Kristiansen, Kai; Israelachvili, Jacob [Chemical Engineering Department, University of California, Santa Barbara, CA 93117 (United States); Zhao, Boxin [Chemical Engineering Department and Waterloo Institute of Nanotechnology, University of Waterloo, Ontario, N2L 3G1 (Canada); Tian Yu [State Key Laboratory of Tribology, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Autumn, Kellar, E-mail: npesika@tulane.ed [Department of Biology, Lewis and Clark College, Portland, OR 97219 (United States)

    2009-11-18

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  5. Adhesive mechanisms in cephalopods: a review.

    von Byern, Janek; Klepal, Waltraud

    2006-01-01

    Several genera of cephalopods (Nautilus, Sepia, Euprymna and Idiosepius) produce adhesive secretions, which are used for attachment to the substratum, for mating and to capture prey. These adhesive structures are located in different parts of the body, viz. in the digital tentacles (Nautilus), in the ventral surface of the mantle and fourth arm pair (Sepia), in the dorsal epidermis (Euprymna), or in the dorsal mantle side and partly on the fins (Idiosepius). Adhesion in Sepia is induced by suction of dermal structures on the mantle, while for Nautilus, Euprymna and Idiosepius adhesion is probably achieved by chemical substances. Histochemical studies indicate that in Nautilus and Idiosepius secretory cells that appear to be involved in adhesion stain for carbohydrates and protein, whilst in Euprymna only carbohydrates are detectable. De-adhesion is either achieved by muscle contraction of the tentacles and mantle (Nautilus and Sepia) or by secretion of substances (Euprymna). The de-adhesive mechanism used by Idiosepius remains unknown. PMID:17110356

  6. Bacterial adhesion and biofilms on surfaces

    Trevor Roger Garrett; Manmohan Bhakoo; Zhibing Zhang

    2008-01-01

    Bacterial adhesion has become a significant problem in industry and in the domicile,and much research has been done for deeper understanding of the processes involved.A generic biological model of bacterial adhesion and population growth called the bacterial biofilm growth cycle,has been described and modified many times.The biofilm growth cycle encompasses bacterial adhesion at all levels,starting with the initial physical attraction of bacteria to a substrate,and ending with the eventual liberation of cell dusters from the biofilm matrix.When describing bacterial adhesion one is simply describing one or more stages of biofilm development,neglecting the fact that the population may not reach maturity.This article provides an overview of bacterial adhesion.cites examples of how bac-terial adhesion affects industry and summarises methods and instrumentation used to improve our understanding of the adhesive prop-erties of bacteria.

  7. Host Selection of Microbiota via Differential Adhesion.

    McLoughlin, Kirstie; Schluter, Jonas; Rakoff-Nahoum, Seth; Smith, Adrian L; Foster, Kevin R

    2016-04-13

    The host epithelium is the critical interface with microbial communities, but the mechanisms by which the host regulates these communities are poorly understood. Here we develop the hypothesis that hosts use differential adhesion to select for and against particular members of their microbiota. We use an established computational, individual-based model to study the impact of host factors that regulate adhesion at the epithelial surface. Our simulations predict that host-mediated adhesion can increase the competitive advantage of microbes and create ecological refugia for slow-growing species. We show how positive selection via adhesion can be transformed into negative selection if the host secretes large quantities of a matrix such as mucus. Our work predicts that adhesion is a powerful mechanism for both positive and negative selection within the microbiota. We discuss molecules-mucus glycans and IgA-that affect microbe adhesion and identify testable predictions of the adhesion-as-selection model. PMID:27053168

  8. Electrochemical Corrosion of Adhesive Joints

    Vondrák, Jiří

    Vol. 2. Brno: Akademické nakladatelství CERM, 2000 - (Vondrák, J.; Sedlaříková, M.), s. 10.1-10.2 ISBN 80-214-1615-7. [Advanced Batteries and Accumulators /1./. Brno (CZ), 28.08.2000-01.09.2000] Institutional research plan: CEZ:AV0Z4032918 Keywords : adhesive * joints * corrosion Subject RIV: CG - Electrochemistry

  9. Underwater adhesion: The barnacle way

    Khandeparker, L.; Anil, A.C.

    surrounded by calcium carbonate (calcite). It has been suggested that the anionic groups on the matric proteins may serve as sites for nucleation during calcification [47]. The disruption in such interactions can thus bring about hindrance during... of bones, nerves and blood vessels in an aqueous environment and dental filling without the need for drilling [83]. It has been suggested that with the advances in biomimetics, future dentin adhesive monomers may contain domains derived from...

  10. Culinary Medicine-Jalebi Adhesions.

    Kapoor, Vinay K

    2016-02-01

    Culinary terms have been used to describe anatomy (bean-shaped kidneys), pathology (strawberry gall bladder), clinical signs (café-au-lait spots), radiological images (sausage-shaped pancreas), etc. While Indian cuisine is popular all over the world, no Indian dish finds mention in medical terminology. In intra-abdominal adhesions, sometimes, the intestinal loops are so densely adherent that it is difficult to make out proximal from distal and it is impossible to separate them without injuring the bowel resulting in spill of contents-resection is the only option (Fig. 1). Jalebi, an Indian dessert, has a single long tubular strip of fried batter filled with sugary syrup so intertwined that it is impossible to discern its ends; if broken, the syrup spills out-the best way to relish it is to chew the whole piece (Fig. 2). Because of these similarities between them, I propose to name dense intra-abdominal adhesions as 'jalebi adhesions.' PMID:27186047

  11. [Adhesion to the antiretroviral treatment].

    Carballo, M

    2004-12-01

    The objective of the therapy antiretroviral is to improve the quality of life and the survival of the persons affected by the VIH through the suppression of the viral replication. Nevertheless one of the present problems is the resistant apparition of stumps to the new medicines caused by an incorrect management of the therapeutic plan; by an incorrect adhesion of the personal processing. Since the therapeutic success will depend, among others factors, and of important form of the degree of implication and commitment of the person affected, is a matter of identifying prematurely the possible situations concomitants (personal factors and of addiction, psycho-social, related to the processing and its possible secondary effects, associated factors to the own illness or even to the relation professional-patient) that can interfere in a correct adhesion. For it is necessary of the interaction multidisciplinary of the welfare team, and fundamental the work of nursing at the moment of to detect the possible determinant factors and the intervention definition of strategies arrived at by consensus with the own person, that they promote it or it improve. The quantification of the degree of adhesion (measure in %) values through various direct and indirect methods and should keep in mind in it takes of therapeutic decisions being able to come to be advised the suspension of the processing until obtaining to conscience to the person affected of the importance of a correct therapeutic compliance. PMID:15672996

  12. Decrease of Staphylococcal adhesion on surgical stainless steel after Si ion implantation

    Highlights: • Si ion implantation of AISI 316LVM medical grade alloy might reduce bacterial adhesion and colonization. • Si ion implantation does not impair the attachment, viability and matrix maturation of human mesenchymal stem cells. • Nano-topography and surface chemistry changes account for the Si ion implantation induced effects. - Abstract: 316LVM austenitic stainless steel is often the material of choice on temporal musculoskeletal implants and surgical tools as it combines good mechanical properties and acceptable corrosion resistance to the physiologic media, being additionally relatively inexpensive. This study has aimed at improving the resistance to bacterial colonization of this surgical stainless steel, without compromising its biocompatibility and resistance. To achieve this aim, the effect of Si ion implantation on 316LVM has been studied. First, the effect of the ion implantation parameters (50 keV; fluence: 2.5–5 × 1016 ions/cm2; angle of incidence: 45–90°) has been assessed in terms of depth profiling of chemical composition by XPS and nano-topography evaluation by AFM. The in vitro biocompatibility of the alloy has been evaluated with human mesenchymal stem cells. Finally, bacterial adhesion of Staphylococcus epidermidis and Staphylococcus aureus on these surfaces has been assessed. Reduction of bacterial adhesion on Si implanted 316LVM is dependent on the implantation conditions as well as the features of the bacterial strains, offering a promising implantable biomaterial in terms of biocompatibility, mechanical properties and resistance to bacterial colonization. The effects of surface composition and nano-topography on bacterial adhesion, directly related to ion implantation conditions, are also discussed

  13. Decrease of Staphylococcal adhesion on surgical stainless steel after Si ion implantation

    Braceras, Iñigo, E-mail: inigo.braceras@tecnalia.com [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Pacha-Olivenza, Miguel A. [CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Universidad de Extremadura, Departamento de Física Aplicada, Facultad de Ciencias, Av. Elvas s/n, 06006 Badajoz (Spain); Calzado-Martín, Alicia [Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Multigner, Marta [Centro Nacional de Investigaciones Metalúrgicas, CENIM-CSIC, Avda Gregorio del Amo 8, 28040 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Vera, Carolina [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Broncano, Luis Labajos-; Gallardo-Moreno, Amparo M. [Universidad de Extremadura, Departamento de Física Aplicada, Facultad de Ciencias, Av. Elvas s/n, 06006 Badajoz (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); González-Carrasco, José Luis [Centro Nacional de Investigaciones Metalúrgicas, CENIM-CSIC, Avda Gregorio del Amo 8, 28040 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Vilaboa, Nuria [Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); and others

    2014-08-15

    Highlights: • Si ion implantation of AISI 316LVM medical grade alloy might reduce bacterial adhesion and colonization. • Si ion implantation does not impair the attachment, viability and matrix maturation of human mesenchymal stem cells. • Nano-topography and surface chemistry changes account for the Si ion implantation induced effects. - Abstract: 316LVM austenitic stainless steel is often the material of choice on temporal musculoskeletal implants and surgical tools as it combines good mechanical properties and acceptable corrosion resistance to the physiologic media, being additionally relatively inexpensive. This study has aimed at improving the resistance to bacterial colonization of this surgical stainless steel, without compromising its biocompatibility and resistance. To achieve this aim, the effect of Si ion implantation on 316LVM has been studied. First, the effect of the ion implantation parameters (50 keV; fluence: 2.5–5 × 10{sup 16} ions/cm{sup 2}; angle of incidence: 45–90°) has been assessed in terms of depth profiling of chemical composition by XPS and nano-topography evaluation by AFM. The in vitro biocompatibility of the alloy has been evaluated with human mesenchymal stem cells. Finally, bacterial adhesion of Staphylococcus epidermidis and Staphylococcus aureus on these surfaces has been assessed. Reduction of bacterial adhesion on Si implanted 316LVM is dependent on the implantation conditions as well as the features of the bacterial strains, offering a promising implantable biomaterial in terms of biocompatibility, mechanical properties and resistance to bacterial colonization. The effects of surface composition and nano-topography on bacterial adhesion, directly related to ion implantation conditions, are also discussed.

  14. In vivo modification of tyrosine residues in recombinant mussel adhesive protein by tyrosinase co-expression in Escherichia coli

    Choi Yoo

    2012-10-01

    Full Text Available Abstract Background In nature, mussel adhesive proteins (MAPs show remarkable adhesive properties, biocompatibility, and biodegradability. Thus, they have been considered promising adhesive biomaterials for various biomedical and industrial applications. However, limited production of natural MAPs has hampered their practical applications. Recombinant production in bacterial cells could be one alternative to obtain useable amounts of MAPs, although additional post-translational modification of tyrosine residues into 3,4-dihydroxyphenyl-alanine (Dopa and Dopaquinone is required. The superior properties of MAPs are mainly attributed to the introduction of quinone-derived intermolecular cross-links. To solve this problem, we utilized a co-expression strategy of recombinant MAP and tyrosinase in Escherichia coli to successfully modify tyrosine residues in vivo. Results A recombinant hybrid MAP, fp-151, was used as a target for in vivo modification, and a dual vector system of pET and pACYC-Duet provided co-expression of fp-151 and tyrosinase. As a result, fp-151 was over-expressed and mainly obtained from the soluble fraction in the co-expression system. Without tyrosinase co-expression, fp-151 was over-expressed in an insoluble form in inclusion bodies. The modification of tyrosine residues in the soluble-expressed fp-151 was clearly observed from nitroblue tetrazolium staining and liquid-chromatography-mass/mass spectrometry analyses. The purified, in vivo modified, fp-151 from the co-expression system showed approximately 4-fold higher bulk-scale adhesive strength compared to in vitro tyrosinase-treated fp-151. Conclusion Here, we reported a co-expression system to obtain in vivo modified MAP; additional in vitro tyrosinase modification was not needed to obtain adhesive properties and the in vivo modified MAP showed superior adhesive strength compared to in vitro modified protein. It is expected that this co-expression strategy will accelerate

  15. A chemometric method for correcting FTIR spectra of biomaterials for interference from water in KBr discs

    FTIR analysis of solid biomaterials by the familiar KBr disc technique is very often frustrated by water interference in the important protein (amide I) and carbohydrate (hydroxyl) regions of their spectra. A method was therefore devised that overcomes the difficulty and measures FTIR spectra of so...

  16. Antimicrobial biomaterials based on carbon nanotubes dispersed in poly(lactic-co-glycolic acid)

    Aslan, Seyma; Loebick, Codruta Zoican; Kang, Seoktae; Elimelech, Menachem; Pfefferle, Lisa D.; van Tassel, Paul R.

    2010-09-01

    Biomaterials that inactivate microbes are needed to eliminate medical device infections. We investigate here the antimicrobial nature of single-walled carbon nanotubes (SWNTs) incorporated within the biomedical polymer poly(lactic-co-glycolic acid) (PLGA). We find Escherichia coli and Staphylococcus epidermidis viability and metabolic activity to be significantly diminished in the presence of SWNT-PLGA, and to correlate with SWNT length and concentration (bacteria die within one hour on SWNT-PLGA versus 15-20% on pure PLGA. Shorter SWNTs are more toxic, possibly due to increased density of open tube ends. This study demonstrates the potential usefulness of SWNT-PLGA as an antimicrobial biomaterial.Biomaterials that inactivate microbes are needed to eliminate medical device infections. We investigate here the antimicrobial nature of single-walled carbon nanotubes (SWNTs) incorporated within the biomedical polymer poly(lactic-co-glycolic acid) (PLGA). We find Escherichia coli and Staphylococcus epidermidis viability and metabolic activity to be significantly diminished in the presence of SWNT-PLGA, and to correlate with SWNT length and concentration (bacteria die within one hour on SWNT-PLGA versus 15-20% on pure PLGA. Shorter SWNTs are more toxic, possibly due to increased density of open tube ends. This study demonstrates the potential usefulness of SWNT-PLGA as an antimicrobial biomaterial. Electronic supplementary information (ESI) available: Raman spectra before and after SWNT cutting via cyclodextrins, and sample images from viability and metabolic activity assays are included. See DOI: 10.1039/c0nr00329h

  17. Inhibition of the tissue reaction to a biodegradable biomaterial by monoclonal antibodies to IFN-gamma

    Khouw, IMSL; van Wachem, PB; de Leij, LFMH; van Luyn, MJA

    1998-01-01

    Biomaterials are increasingly used for clinical applications. However, loss of function may occur owing to tissue reactions, which are mainly caused by a variety of inflammatory reactions. Recently, we demonstrated that macrophages (MO) and T cells play key roles in these reactions. Since immunologi

  18. Biomaterial-associated infection of gentamicin-loaded PMMA beads in orthopaedic revision surgery

    Neut, D; van de Belt, H; Stokroos, [No Value; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    2001-01-01

    In two-stage orthopaedic revision surgery, high local levels of antibiotics are achieved after removal of an infected prosthesis through temporary implantation of gentamicin-loaded beads. However, despite their antibiotic release, these beads act as a biomaterial surface to which bacteria preferenti

  19. Determination of optical properties in dental restorative biomaterials using the inverse-adding-doubling method

    Fernández-Oliveras, Alicia; Rubiño, Manuel; Pérez, María. M.

    2013-11-01

    Light propagation in biological media is characterized by the absorption coefficient, the scattering coefficient, the scattering phase function, the refractive index, and the surface conditions (roughness). By means of the inverse-adding-doubling (IAD) method, transmittance and reflectance measurements lead to the determination of the absorption coefficient and the reduced scattering coefficient. The additional measurement of the phase function performed by goniometry allows the separation of the reduced scattering coefficient into the scattering coefficient and the scattering anisotropy factor. The majority of techniques, such as the one utilized in this work, involve the use of integrating spheres to measure total transmission and reflection. We have employed an integrating sphere setup to measure the total transmittance and reflectance of dental biomaterials used in restorative dentistry. Dental biomaterials are meant to replace dental tissues, such as enamel and dentine, in irreversibly diseased teeth. In previous works we performed goniometric measurements in order to evaluate the scattering anisotropy factor for these kinds of materials. In the present work we have used the IAD method to combine the measurements performed using the integrating sphere setup with the results of the previous goniometric measurements. The aim was to optically characterize the dental biomaterials analyzed, since whole studies to assess the appropriate material properties are required in medical applications. In this context, complete optical characterizations play an important role in achieving the fulfillment of optimal quality and the final success of dental biomaterials used in restorative dentistry.

  20. Generation and Assessment of Functional Biomaterial Scaffolds for Applications in Cardiovascular Tissue Engineering and Regenerative Medicine.

    Hinderer, Svenja; Brauchle, Eva; Schenke-Layland, Katja

    2015-11-18

    Current clinically applicable tissue and organ replacement therapies are limited in the field of cardiovascular regenerative medicine. The available options do not regenerate damaged tissues and organs, and, in the majority of the cases, show insufficient restoration of tissue function. To date, anticoagulant drug-free heart valve replacements or growing valves for pediatric patients, hemocompatible and thrombus-free vascular substitutes that are smaller than 6 mm, and stem cell-recruiting delivery systems that induce myocardial regeneration are still only visions of researchers and medical professionals worldwide and far from being the standard of clinical treatment. The design of functional off-the-shelf biomaterials as well as automatable and up-scalable biomaterial processing methods are the focus of current research endeavors and of great interest for fields of tissue engineering and regenerative medicine. Here, various approaches that aim to overcome the current limitations are reviewed, focusing on biomaterials design and generation methods for myocardium, heart valves, and blood vessels. Furthermore, novel contact- and marker-free biomaterial and extracellular matrix assessment methods are highlighted. PMID:25778713

  1. Synthetic poly(amino acid)-based biomaterials for tissue regeneration

    Rypáček, František; Studenovská, Hana; Proks, Vladimír; Machová, Luďka; Vodička, Petr; Hlučilová, Jana; Motlík, Jan

    Toronto: Department of Aerospace & Mechanical Engineering, Ryerson University, 2006. s. 155. [International Conference on Processing & Manufacturing of Advanced Materials. 04.07.2006-08.07.2006, Vancouver] R&D Projects: GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505 Keywords : biomaterials * poly(amino acids) * tissue regeneration Subject RIV: CD - Macromolecular Chemistry

  2. METHYLCELLULOSE CELL-CULTURE AS A NEW CYTOTOXICITY TEST SYSTEM FOR BIOMATERIALS

    VANLUYN, MJA; VANWACHEM, PB; NIEUWENHUIS, P; DAMINK, LO; TENHOOPEN, H; FEIJEN, J

    1991-01-01

    The cytotoxicity of biomaterials can be tested in vitro using various culture systems. Liquid culture systems may detect cytotoxicity of a material either by culture of cells with extracts or with the material itself. In the latter instance, renewing the medium will remove possible released cytotoxi

  3. Biomaterial porosity determined by fractal dimensions, succolarity and lacunarity on microcomputed tomographic images

    N' Diaye, Mambaye [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France); Degeratu, Cristinel [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France); University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Department of Bioresources and Polymer Science, Calea Victoriei 149, 010072, Sector 1, Bucharest (Romania); Bouler, Jean-Michel [Inserm UMR 791, LIOAD, University of Nantes, 44000 Nantes (France); Chappard, Daniel, E-mail: daniel.chappard@univ-angers.fr [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France)

    2013-05-01

    Porous structures are becoming more and more important in biology and material science because they help in reducing the density of the grafted material. For biomaterials, porosity also increases the accessibility of cells and vessels inside the grafted area. However, descriptors of porosity are scanty. We have used a series of biomaterials with different types of porosity (created by various porogens: fibers, beads …). Blocks were studied by microcomputed tomography for the measurement of 3D porosity. 2D sections were re-sliced to analyze the microarchitecture of the pores and were transferred to image analysis programs: star volumes, interconnectivity index, Minkowski–Bouligand and Kolmogorov fractal dimensions were determined. Lacunarity and succolarity, two recently described fractal dimensions, were also computed. These parameters provided a precise description of porosity and pores' characteristics. Non-linear relationships were found between several descriptors e.g. succolarity and star volume of the material. A linear correlation was found between lacunarity and succolarity. These techniques appear suitable in the study of biomaterials usable as bone substitutes. Highlights: ► Interconnected porosity is important in the development of bone substitutes. ► Porosity was evaluated by 2D and 3D morphometry on microCT images. ► Euclidean and fractal descriptors measure interconnectivity on 2D microCT images. ► Lacunarity and succolarity were evaluated on a series of porous biomaterials.

  4. Ica-expression and gentamicin susceptibility of Staphylococcus epidermidis biofilm on orthopedic implant biomaterials

    Nuryastuti, Titik; Krom, Bastiaan P.; Aman, Abu T.; Busscher, Henk J.; van der Mei, Henny C.

    2011-01-01

    Ica-expression by Staphylococcus epidermidis and slime production depends on environmental conditions such as implant material and presence of antibiotics. Here, we evaluate biofilm formation and ica-expression of S. epidermidis strains on biomaterials involved in total hip-and knee arthroplasty [po

  5. Micro/nano-scale strategies for engineering in vitro the celular microenvironment using biodegradable biomaterials

    Coutinho, Daniela F.

    2011-01-01

    Programa doutoral em Bioengenharia Biological tissues result of a specific spatial organization of cells, extracellular matrix (ECM) molecules, and soluble factors. These micro and nanoscaled biological entities organize into regional tissue architectures, creating highly complex and heterogeneous cellular microenvironments. To generate functional tissue equivalents in vitro, engineered biomaterials should mimic the structural, chemical and cellular complexity by recapitulating...

  6. New method of synthesis and in vitro studies of a porous biomaterial.

    Wers, E; Lefeuvre, B; Pellen-Mussi, P; Novella, A; Oudadesse, H

    2016-04-01

    Biomaterials for bone reconstruction represent a widely studied area. In this paper, a new method of synthesis of a porous glass-ceramic obtained by thermal treatment is presented. The prepared biomaterial was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and induced couple plasma-optical emission spectroscopy (ICP-OES), mercury porosimetry and by the Archimedes method. In vitro evaluations in a simulated body fluid (SBF) and in contact with SaOS2 human osteoblasts were also carried out. The porous glass-ceramic is composed of a total porous network of 60% suitable for body fluid and cell infiltration, with pore sizes varying from 60 nm to 143 μm. The presence of two crystalline phases decreases the kinetic of bioactivity compared to an amorphous biomaterial (bioactive glass). A hydroxyapatite layer appears from 15 days of immersion on the surface and inside the pores, showing a biodegradation and a bioactivity in four steps. Cytotoxicity assessments present an increase of the cellular viability after 72 h proving the non-cytotoxic effect of the glass-ceramic. Thus, the results of these different studies indicate that the porous biomaterial may have a potential application for the bone regeneration. This paper also presents the novelty of this method. It is a rapid synthesis which combines simplicity and low cost. This represents an advantage for an eventual industrialization. PMID:26838833

  7. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    Shirtcliffe, Neil; McHale, Glen; Newton, Michael

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and th...

  8. In vivo biocompatibility of new nano-calcium-deficient hydroxyapatite/poly-amino acid complex biomaterials

    Dai ZY

    2015-10-01

    Full Text Available Zhenyu Dai,1,2,* Yue Li,3,* Weizhong Lu,2,* Dianming Jiang,4 Hong Li,1 Yonggang Yan,1 Guoyu Lv,1 Aiping Yang1 1College of Physical Science and Technology, Sichuan University, Chengdu, 2Department of Orthopedics, Chongqing Hospital of Traditional Chinese Medicine, 3Department of Clinical Laboratory, the Second Affiliated Hospital, 4Department of Orthopedics, the First Affiliated Hospital, Chongqing Medical University, Chongqing, People’s Republic of China *These authors contributed equally to this work Objective: To evaluate the compatibility of novel nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA complex biomaterials with muscle and bone tissue in an in vivo model.Methods: Thirty-two New Zealand white rabbits were used in this study. Biomaterials were surgically implanted into each rabbit in the back erector spinae and in tibia with induced defect. Polyethylene was implanted into rabbits in the control group and n-CDHA/PAA into those of the experimental group. Animals were examined at four different points in time: 2 weeks, 4 weeks, 12 weeks, and 24 weeks after surgery. They were euthanized after embolization. Back erector spinae muscles with the surgical implants were examined after hematoxylin and eosin (HE staining at these points in time. Tibia bones with the surgical implants were examined by X-ray and scanning electron microscopy (SEM at these points in time to evaluate the interface of the bone with the implanted biomaterials. Bone tissues were sectioned and subjected to HE, Masson, and toluidine blue staining.Results: HE staining of back erector spinae muscles at 4 weeks, 12 weeks, and 24 weeks after implantation of either n-CDHA/PAA or polyethylene showed disappearance of inflammation and normal arrangement in the peripheral tissue of implant biomaterials; no abnormal staining was observed. At 2 weeks after implantation, X-ray imaging of bone tissue samples in both experimental and control groups showed that

  9. Development of a bovine decellularized extracellular matrix-biomaterial for nucleus pulposus regeneration.

    Illien-Jünger, Svenja; Sedaghatpour, Dillon D; Laudier, Damien M; Hecht, Andrew C; Qureshi, Sheeraz A; Iatridis, James C

    2016-05-01

    Painful intervertebral disc (IVD) degeneration is a common cause for spinal surgery. There is a clinical need to develop injectable biomaterials capable of promoting IVD regeneration, yet many available biomaterials do not mimic the native extracellular matrix (ECM) or promote matrix production. This study aimed to develop a decellularized injectable bovine ECM material that maintains structural and compositional features of native tissue and promotes nucleus pulposus (NP) cell (NPC) and mesenchymal stem cell (MSC) adaption. Injectable decellularized ECM constructs were created using 3 NP tissue decellularization methods (con.A: sodium deoxycholate, con.B: sodium deoxycholate & sodium dodecyl sulfate, con.C: sodium deoxycholate, sodium dodecyl sulfate & TritonX-100) and evaluated for protein, microstructure, and for cell adaptation in 21 day human NPC and MSC culture experiments. Con.A was most efficient at DNA depletion, preserved best collagen microstructure and content, and maintained the highest glycosaminoglycan (GAG) content. NPCs in decellularized constructs of con.A&B demonstrated newly synthesized GAG production, which was apparent from "halos" of GAG staining surrounding seeded NPCs. Con.A also promoted MSC adaption with high cell viability and ECM production. The injectable decellularized NP biomaterial that used sodium deoxycholate without additional decellularization steps maintained native NP tissue structure and composition closest to natural ECM and promoted cellular adaptation of NP cells and MSCs. This natural decellularized biomaterial warrants further investigation for its potential as an injectable cell seeded supplement to augment NP replacement biomaterials and deliver NPCs or MSCs. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:876-888, 2016. PMID:26509556

  10. Polymer films with surfaces unmodified and modified by non-thermal plasma as new substrates for cell adhesion

    Borges, A.M.G.; Benetoli, L.O. [Department of Chemistry, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil); Licínio, M.A. [Department of Clinical Analysis, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil); Zoldan, V.C. [Department of Physical, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil); Santos-Silva, M.C. [Department of Clinical Analysis, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil); Assreuy, J. [Department of Pharmacology, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil); Pasa, A.A. [Department of Physical, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil); Debacher, N.A. [Department of Chemistry, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil); Soldi, V., E-mail: vsoldi@pq.cnpq.br [Department of Chemistry, Federal University of Santa Catarina, 88040-900 Florianopolis (Brazil)

    2013-04-01

    The surface properties of biomaterials, such as wettability, polar group distribution, and topography, play important roles in the behavior of cell adhesion and proliferation. Gaseous plasma discharges are among the most common means to modify the surface of a polymer without affecting its properties. Herein, we describe the surface modification of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) films using atmospheric pressure plasma processing through exposure to a dielectric barrier discharge (DBD). After treatment the film surface showed significant changes from hydrophobic to hydrophilic as the water contact angle decreasing from 95° to 37°. All plasma-treated films developed more hydrophilic surfaces compared to untreated films, although the reasons for the change in the surface properties of PS and PMMA differed, that is, the PS showed chemical changes and in the case of PMMA they were topographical. Excellent adhesion and cell proliferation were observed in all films. In vitro studies employing flow cytometry showed that the proliferation of L929 cells was higher in the film formed by a 1:1 mixture of PS/PMMA, which is consistent with the results of a previous study. These findings suggest better adhesion of L929 onto the 1:1 PS/PMMA modified film, indicating that this system is a new candidate biomaterial for tissue engineering. Highlights: ► The PS/PMMA films showed hydrophilic surface after DBD-treatment. ► The 1:1 PS/PMMA modified film is a new substrate for L929 cell proliferation. ► The 1:1 PS/PMMA blend film showed additional 170 × 10{sup 3} cells after treatment. ► The proliferation of cells in the blend film triplicated when compared to control. ► Synergistic effect improves cell proliferation in the blend film.

  11. Physical vapor deposited titanium thin films for biomedical applications: Reproducibility of nanoscale surface roughness and microbial adhesion properties

    Lüdecke, Claudia [Chair of Materials Science (CMS), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, D-07743, Jena (Germany); Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Bio Pilot Plant, Beutenbergstraße 11a, D-07745, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany); Bossert, Jörg [Chair of Materials Science (CMS), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, D-07743, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany); Roth, Martin [Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Bio Pilot Plant, Beutenbergstraße 11a, D-07745, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany); Jandt, Klaus D., E-mail: k.jandt@uni-jena.de [Chair of Materials Science (CMS), Faculty of Physics and Astronomy, Friedrich Schiller University Jena, Löbdergraben 32, D-07743, Jena (Germany); Jena Center for Soft Mater, Friedrich Schiller University Jena, Jena (Germany); Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Jena (Germany)

    2013-09-01

    The surface topography is of great importance for the biological performance of titanium based implants since it may influence the initial adsorption of proteins, cell response, as well as microbial adhesion. A recently described technique for the preparation of titanium thin films with an adjustable surface roughness on the nanometer scale is the physical vapor deposition (PVD). The aims of this study were to statistically evaluate the reproducibility of nanorough titanium thin films prepared by PVD using an atomic force microscopy (AFM) based approach, to test the microbial adhesion in dependence of the nanoscale surface roughness and to critically discuss the parameters used for the characterization of the titanium surfaces with respect to AFM microscope settings. No statistically significant differences were found between the surface nanoroughnesses of the PVD prepared titanium thin films. With increasing surface nanoroughness, the coverage by Escherichia coli decreased and the microbial cells were increasingly patchy distributed. The calculated roughness values significantly increased with increasing AFM scan size, while image resolution and pixel density had no influence on this effect. Our study shows that PVD is a suitable tool to reproducibly prepare titanium thin films with a well-defined surface topography on the nanometer scale. These surfaces are, thus, a suitable 2D model system for studies addressing the interaction between surface nanoroughness and the biological system. First results show that surface roughness even on the very low nanometer scale has an influence on bacterial adhesion behavior. These findings give new momentum to biomaterials research and will support the development of biomaterials surfaces with anti-infectious surface properties.

  12. Polymer films with surfaces unmodified and modified by non-thermal plasma as new substrates for cell adhesion

    The surface properties of biomaterials, such as wettability, polar group distribution, and topography, play important roles in the behavior of cell adhesion and proliferation. Gaseous plasma discharges are among the most common means to modify the surface of a polymer without affecting its properties. Herein, we describe the surface modification of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) films using atmospheric pressure plasma processing through exposure to a dielectric barrier discharge (DBD). After treatment the film surface showed significant changes from hydrophobic to hydrophilic as the water contact angle decreasing from 95° to 37°. All plasma-treated films developed more hydrophilic surfaces compared to untreated films, although the reasons for the change in the surface properties of PS and PMMA differed, that is, the PS showed chemical changes and in the case of PMMA they were topographical. Excellent adhesion and cell proliferation were observed in all films. In vitro studies employing flow cytometry showed that the proliferation of L929 cells was higher in the film formed by a 1:1 mixture of PS/PMMA, which is consistent with the results of a previous study. These findings suggest better adhesion of L929 onto the 1:1 PS/PMMA modified film, indicating that this system is a new candidate biomaterial for tissue engineering. Highlights: ► The PS/PMMA films showed hydrophilic surface after DBD-treatment. ► The 1:1 PS/PMMA modified film is a new substrate for L929 cell proliferation. ► The 1:1 PS/PMMA blend film showed additional 170 × 103 cells after treatment. ► The proliferation of cells in the blend film triplicated when compared to control. ► Synergistic effect improves cell proliferation in the blend film

  13. Experimental Investigation of Optimal Adhesion of Mushroomlike Elastomer Microfibrillar Adhesives.

    Marvi, Hamidreza; Song, Sukho; Sitti, Metin

    2015-09-22

    Optimal fiber designs for the maximal pull-off force have been indispensable for increasing the attachment performance of recently introduced gecko-inspired reversible micro/nanofibrillar adhesives. There are several theoretical studies on such optimal designs; however, due to the lack of three-dimensional (3D) fabrication techniques that can fabricate such optimal designs in 3D, there have not been many experimental investigations on this challenge. In this study, we benefitted from recent advances in two-photon lithography techniques to fabricate mushroomlike polyurethane elastomer fibers with different aspect ratios of tip to stalk diameter (β) and tip wedge angles (θ) to investigate the effect of these two parameters on the pull-off force. We found similar trends to those predicted theoretically. We found that β has an impact on the slope of the force-displacement curve while both β and θ play a role in the stress distribution and crack propagation. We found that these effects are coupled and the optimal set of parameters also depends on the fiber material. This is the first experimental verification of such optimal designs proposed for mushroomlike microfibers. This experimental approach could be used to evaluate a wide range of complex microstructured adhesive designs suggested in the literature and optimize them. PMID:26322396

  14. Synaptic Cell Adhesion Molecules in Alzheimer's Disease

    Leshchyns'ka, Iryna

    2016-01-01

    Alzheimer's disease (AD) is a neurodegenerative brain disorder associated with the loss of synapses between neurons in the brain. Synaptic cell adhesion molecules are cell surface glycoproteins which are expressed at the synaptic plasma membranes of neurons. These proteins play key roles in formation and maintenance of synapses and regulation of synaptic plasticity. Genetic studies and biochemical analysis of the human brain tissue, cerebrospinal fluid, and sera from AD patients indicate that levels and function of synaptic cell adhesion molecules are affected in AD. Synaptic cell adhesion molecules interact with Aβ, a peptide accumulating in AD brains, which affects their expression and synaptic localization. Synaptic cell adhesion molecules also regulate the production of Aβ via interaction with the key enzymes involved in Aβ formation. Aβ-dependent changes in synaptic adhesion affect the function and integrity of synapses suggesting that alterations in synaptic adhesion play key roles in the disruption of neuronal networks in AD. PMID:27242933

  15. The Rheological Property of Potato Starch Adhesives

    Junjun Liu

    2014-02-01

    Full Text Available The main goal of this study was to use potato starch in the production of environmentally sound adhesives. ‘Three-formaldehyde glue’ pollutes the environment and harms to human health strongly, which widely used for wood-based panels preparation. Environment-friendly potato starch adhesives were prepared using method of oxidation-gelatinization, insteading of the three formaldehyde glue. The effects of the quality ratio of starch and water, temperature and shear rate on the apparent viscosity of the adhesive were studied. The rheological eigenvalue of apparent viscosity was studied through nonlinear regression. The results showed that the apparent viscosity of potato starch adhesives decreased with the increasing of temperature; the apparent viscosity decreased slowly with the increasing of rotor speed; the phenomenon of shear thinning appeared within potato starch adhesives which was pseudo-plastic fluids. Potato starch adhesives with characteristics of non-toxic, no smell and pollution could be applied in interior and upscale packaging.

  16. Study of the adhesive properties versus stability/aging of hernia repair meshes after deposition of RF activated plasma polymerized acrylic acid coating.

    Rivolo, Paola; Nisticò, Roberto; Barone, Fabrizio; Faga, Maria Giulia; Duraccio, Donatella; Martorana, Selanna; Ricciardi, Serena; Magnacca, Giuliana

    2016-08-01

    In order to confer adhesive properties to commercial polypropylene (PP) meshes, a surface plasma-induced deposition of poly-(acrylic acid) (PPAA) is performed. Once biomaterials were functionalized, different post-deposition treatments (i.e. water washing and/or thermal treatments) were investigated with the aim of monitoring the coating degradation (and therefore the loss of adhesion) after 3months of aging in both humid/oxidant (air) and inert (nitrogen) atmospheres. A wide physicochemical characterization was carried out in order to evaluate the functionalization effectiveness and the adhesive coating homogeneity by means of static water drop shape analysis and several spectroscopies (namely, FTIR, UV-Visible and X-ray Photoemission Spectroscopy). The modification of the adhesion properties after post-deposition treatments as well as aging under different storage atmospheres were investigated by means of Atomic Force Microscopy (AFM) used in Force/Distance (F/D) mode. This technique confirms itself as a powerful tool for unveiling the surface adhesion capacity as well as the homogeneity of the functional coatings along the fibers. Results obtained evidenced that post-deposition treatments are mandatory in order to remove all oligomers produced during the plasma-treatment, whereas aging tests evidenced that these devices can be simply stored in presence of air for at least three months without a meaningful degradation of the original properties. PMID:27157754

  17. Lignin-Furfural Based Adhesives

    Prajakta Dongre; Mark Driscoll; Thomas Amidon; Biljana Bujanovic

    2015-01-01

    Lignin recovered from the hot-water extract of sugar maple (Acer saccharum) is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF) resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR) analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC). The effect of pH (0.3, 0.65 and 1), ex situ furfural, and curing conditions on the tensile properties of a...

  18. Lignin-Furfural Based Adhesives

    Prajakta Dongre; Mark Driscoll; Thomas Amidon; Biljana Bujanovic

    2015-01-01

    Lignin recovered from the hot-water extract of sugar maple ( Acer saccharum ) is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF) resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR) analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC). The effect of pH (0.3, 0.65 and 1), ex situ furfural, and curing conditions on the tensile properties of...

  19. Advances in the targeting molecules modified chitosan-based nanoformulations.

    Du, Hongliang; Cai, Xiaoqing; Zhai, Guangxi

    2013-08-01

    Chitosan, a cationic polysaccharide, has prompted the continuous impetus for the development of safe and effective drug delivery systems due to its unique properties such as mucoadhesive feature, absorption enhancement and active functional groups for chemical modifications. By using chitosan-based nanoformulations, many studies have attempted to improve the dispersion of loaded hydrophobic drugs in aqueous environment, protect the encapsulated proteins and genes against enzymatic degradation, and increase their absorption by target tissues. It's noteworthy that the derivatization of chitosan-based carriers with a ligand leads to the selective targeting of the nanoformulations to selected cells, thereby facilitating far more sensitive internalization and localization of nanoformulations for diseases' diagnosis and treatment. As such, this review focuses on some of the most poignant reports of the utility of targeting molecules such as carbohydrates, antibodies, peptides and some small molecules in chitosan-based nanoformulations for targeted delivery. Additionally, the affinity mechanism of different targeting molecules and the pros and cons of their conjugation strategies will be illustrated summarily. PMID:23469876

  20. Physical properties of organic and biomaterials: Fundamentals and applications

    Steven, Eden

    magnetic field independent conductivity at low temperatures. This allows their use as micro-wires and flexible electrodes for transport measurements of small organic samples. I also found that neat spider silk fiber can be used as the mask for lithographic processes, providing a simple route of fabricating adhesive stamp electrodes for measuring transport properties of supra-micron samples in the lateral range of 15 mum--100 mum and thickness > 1 mum at low temperatures and high magnetic fields. The current-voltage characteristic of the insulating channel in tape adhesive electrodes revealed Fowler-Nordheim tunneling mechanism. For electronic sensing and actuating device applications, I have developed a simple method for silk functionalization with carbon nanotubes (CNT) facilitated by polar attraction and supercontraction, a phenomenon where silk is softened when exposed to water. Uniform CNT coating and CNT penetration into the silk fiber surface are evident from the SEM and cross-sectional TEM studies. The conductivity of the carbon nanotube functionalized silk fiber (CNT-SS) follows variable range hopping behavior with activation energy similar to that observed in buckpaper. In addition to being electrically conducting, the CNT-SS is custom-shapeable, flexible, and sensitive to humidity, allowing its use as a heart-pulse and humidity resistive sensors, as well as for current-driven actuators. Finally, I present the investigation of the processed Bombyx mori silk thin film. The silk thin film exhibits actuating and self-healing properties similar to those of a biological muscle. Proof-of-concept silk-based bio-mimetic muscle and water-based memory device are demonstrated. The silk thin film is also used as the dielectric layer of a diF-TESADT organic field effect transistor (FET) where I observed a lower operating voltage and an enhancement in the mobility of the device compared with the FET using SiO 2 dielectric layer, accompanied with an anomalous source

  1. Syndecan-4 and focal adhesion function

    Woods, A; Couchman, J R

    2001-01-01

    Two groups have now reported the viability of mice that lack syndecan-4. These mice have wound healing/angiogenesis problems, and fibroblasts from these animals differ in adhesion and migration from normal. This is consistent with recent in vitro data indicating a need for signaling via syndecan-4...... for focal adhesion formation, and reports that overexpression of proteins that bind syndecan-4 can modify cell adhesion and migration....

  2. Tuning the kinetics of cadherin adhesion

    Sivasankar, Sanjeevi

    2013-01-01

    Cadherins are Ca2+ dependent cell-cell adhesion proteins that maintain the structural integrity of the epidermis; their principle function is to resist mechanical force. This review summarizes the biophysical mechanisms by which classical cadherins tune adhesion and withstand mechanical stress. We first relate the structure of classical cadherins to their equilibrium binding properties. We then review the role of mechanical perturbations in tuning the kinetics of cadherin adhesion. In particu...

  3. Factors influencing bacterial adhesion to contact lenses

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The ...

  4. Biodegradable copolymers carrying cell-adhesion peptide sequences.

    Proks, Vladimír; Machová, Lud'ka; Popelka, Stepán; Rypácek, Frantisek

    2003-01-01

    Amphiphilic block copolymers are used to create bioactive surfaces on biodegradable polymer scaffolds for tissue engineering. Cell-selective biomaterials can be prepared using copolymers containing peptide sequences derived from extracellular-matrix proteins (ECM). Here we discuss alternative ways for preparation of amphiphilic block copolymers composed of hydrophobic polylactide (PLA) and hydrophilic poly(ethylene oxide) (PEO) blocks with cell-adhesion peptide sequences. Copolymers PLA-b-PEO were prepared by a living polymerisation of lactide in dioxane with tin(II)2-ethylhexanoate as a catalyst. The following approaches for incorporation of peptides into copolymers were elaborated. (a) First, a side-chain protected Gly-Arg-Gly-Asp-Ser-Gly (GRGDSG) peptide was prepared by solid-phase peptide synthesis (SPPS) and then coupled with delta-hydroxy-Z-amino-PEO in solution. In the second step, the PLA block was grafted to it via a controlled polymerisation of lactide initiated by the hydroxy end-groups of PEO in the side-chain-protected GRGDSG-PEO. Deprotection of the peptide yielded a GRGDSG-b-PEO-b-PLA copolymer, with the peptide attached through its C-end. (b) A protected GRGDSG peptide was built up on a polymer resin and coupled with Z-carboxy-PEO using a solid-phase approach. After cleavage of the delta-hydroxy-PEO-GRGDSG copolymer from the resin, polymerisation of lactide followed by deprotection of the peptide yielded a PLA-b-PEO-b-GRGDSG block copolymer, in which the peptide is linked through its N-terminus. PMID:12903721

  5. Improving controllable adhesion on both rough and smooth surfaces with a hybrid electrostatic/gecko-like adhesive

    Ruffatto, Donald; Parness, Aaron; Spenko, Matthew

    2014-01-01

    This paper describes a novel, controllable adhesive that combines the benefits of electrostatic adhesives with gecko-like directional dry adhesives. When working in combination, the two technologies create a positive feedback cycle whose adhesion, depending on the surface type, is often greater than the sum of its parts. The directional dry adhesive brings the electrostatic adhesive closer to the surface, increasing its effect. Similarly, the electrostatic adhesion helps engage more of the di...

  6. Studies by nuclear and physico-chemical methods of tissue's metallic contamination located around biomaterials. Toxicity measurements of several biomaterials residual radioactivity

    Implants used as biomaterials fulfill conditions of functionality, compatibility and occasionally bio-activity. There are four main families of biomaterials: metals and metal alloys, polymers, bio-ceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. These debris develop different problems: toxicity, inflammatory reactions, prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters which have an influence on tissue response. We characterize metallic contamination coming from knee prosthesis into surrounding capsular tissue by depth migration, in vivo behaviours, content, size and nature of debris. The PIXE-RBS and STEM-EDXS methods, that we used, are complementary, especially about characterization scale. Debris contamination distributed in the whole articulation is very heterogeneous. Debris migrate on several thousands μm in tissue. Solid metallic particles, μm, are found in the most polluted samples, for both kinds of alloys TA6V and CrCoMo. In the mean volume analysed by PIXE, the in vivo mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TA6V debris and chemical evolution of CrCoMo debris. Complementary measures of TA6V grains, on a nano-metric scale by STEM-EDXS, show a dissolution of coarse grain (μm) in smaller grains (nm). Locally, TA6V grains of a phase are detected and could indicate a preferential dissolution of β phase (grain boundaries) with dropping of Al and V, both toxic and carcinogenic elements. A thin target protocol development correlates PIXE and histological analysis on the same zone. This protocol allows to locate other pathologies in relationship with weaker metal contamination, μg/g, thanks to the great sensitivity of PIXE method. Harmlessness with respect to the residual radioactivity of several natural or synthetic biomaterials is established, using ultra low background noise γ detection system. (author)

  7. Nucleation and growth of cadherin adhesions

    Cell-cell contact formation relies on the recruitment of cadherin molecules and their anchoring to actin. However, the precise chronology of events from initial cadherin trans-interactions to adhesion strengthening is unclear, in part due to the lack of access to the distribution of cadherins within adhesion zones. Using N-cadherin expressing cells interacting with N-cadherin coated surfaces, we characterized the formation of cadherin adhesions at the ventral cell surface. TIRF and RIC microscopies revealed streak-like accumulations of cadherin along actin fibers. FRAP analysis indicated that engaged cadherins display a slow turnover at equilibrium, compatible with a continuous addition and removal of cadherin molecules within the adhesive contact. Association of cadherin cytoplasmic tail to actin as well as actin cables and myosin II activity are required for the formation and maintenance of cadherin adhesions. Using time lapse microscopy we deciphered how cadherin adhesions form and grow. As lamellipodia protrude, cadherin foci stochastically formed a few microns away from the cell margin. Neo-formed foci coalesced aligned and coalesced with preformed foci either by rearward sliding or gap filling to form cadherin adhesions. Foci experienced collapse at the rear of cadherin adhesions. Based on these results, we present a model for the nucleation, directional growth and shrinkage of cadherin adhesions

  8. Polyampholyte- and nanosilicate-based soft bionanocomposites with tailorable mechanical and cell adhesion properties.

    Jain, Minkle; Matsumura, Kazuaki

    2016-06-01

    Engineered tissues are excellent substitutes for treating organ failure associated with disease, injury, and degeneration. Designing new biomaterials with controlled release profiles, good mechanical properties, and cell adhesion characteristics can be useful for the formation of specific functional tissues. Here, we report the formulation of nanocomposite hydrogels based on carboxylated poly-l-lysine and synthetic clay laponite XLG in which four-arm polyethylene glycol with N-hydroxy succinimide ester (PEG-NHS) was used as the chemical crosslinker. Interestingly, the degradation of this gel could be adjusted from a few days to a few months. Incorporation of laponite XLG resulted in the formation of mechanically tough hydrogels and conferred cytocompatibility. The mechanical properties of the nanocomposite could be modulated by changing the crosslinking density and laponite concentration. The feasibility of using this system for cellular therapies was investigated by evaluating cell adhesion on the nanocomposite surface. Thus, these nanocomposites can serve as scaffolds with tunable mechanical and degradation properties that also provide structural integrity to tissue constructs. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1379-1386, 2016. PMID:26833827

  9. Biofilm formation, bacterial adhesion and host response on polymeric implants-issues and prevention

    Several polymeric materials find application in biomedical implants and devices due to their superior physicochemical properties. The main requirement for these polymers is that they should be biocompatible, which means they prevent bacterial adhesion and are blood compatible. Many parameters contribute to the degree of biocompatibility. This paper discusses the mechanism of the formation of biofilms and lists the factors that influence the bacterial adhesion and haemocompatibility. Polymer surfaces are also modified to enhance adsorption of host cells. The physical, chemical and biological techniques are meant to modify the surface of the biomaterial but at the same time retain the key properties. The various polymer treatment processes have advantages and disadvantages and a few techniques have been proved to be both highly effective at treatment and found suitable for various in vivo environments. The current research focus pertaining to smart materials, biodegradable polymers, combinatorial chemistry, computational modelling and newer analytical techniques to understand polymer-cell interaction holds promise in designing better, cost effective and biocompatible polymers

  10. Washing-resistant surfactant coated surface is able to inhibit pathogenic bacteria adhesion

    Treter, Janine; Bonatto, Fernando; Krug, Cristiano; Soares, Gabriel Vieira; Baumvol, Israel Jacob Rabin; Macedo, Alexandre José

    2014-06-01

    Surface-active substances, which are able to organize themselves spontaneously on surfaces, triggering changes in the nature of the solid-liquid interface, are likely to influence microorganism adhesion and biofilm formation. Therefore, this study aimed to evaluate chemical non-ionic surfactants activity against pathogenic microbial biofilms and to cover biomaterial surfaces in order to obtain an anti-infective surface. After testing 11 different surfactants, Pluronic F127 was selected for further studies due to its non-biocidal properties and capability to inhibit up to 90% of biofilm formation of Gram-positive pathogen and its clinical isolates. The coating technique using direct impregnation on the surface showed important antibiofilm formation characteristics, even after extensive washes. Surface roughness and bacterial surface polarity does not influence the adhesion of Staphylococcus epidermidis, however, the material coated surface became extremely hydrophilic. The phenotype of S. epidermidis does not seem to have been affected by the contact with surfactant, reinforcing the evidence that a physical phenomenon is responsible for the activity. This paper presents a simple method of surface coating employing a synthetic surfactant to prevent S. epidermidis biofilm formation.

  11. Design and fabrication of polymer based dry adhesives inspired by the gecko adhesive system

    Jin, Kejia

    There has been significant interest in developing dry adhesives mimicking the gecko adhesive system, which offers several advantages compared to conventional pressure sensitive adhesives. Specifically, gecko adhesive pads have anisotropic adhesion properties: the adhesive pads (spatulae) stick strongly when sheared in one direction but are non-adherent when sheared in the opposite direction. This anisotropy property is attributed to the complex topography of the array of fine tilted and curved columnar structures (setae) that bear the spatulae. In this thesis, easy, scalable methods, relying on conventional and unconventional techniques are presented to incorporate tilt in the fabrication of synthetic polymer-based dry adhesives mimicking the gecko adhesive system, which provide anisotropic adhesion properties. In the first part of the study, the anisotropic adhesion and friction properties of samples with various tilt angles to test the validity of a nanoscale tape-peeling model of spatular function are measured. Consistent with the Peel Zone model, samples with lower tilt angles yielded larger adhesion forces. Contact mechanics of the synthetic array were highly anisotropic, consistent with the frictional adhesion model and gecko-like. Based on the original design, a new design of gecko-like dry adhesives was developed which showed superior tribological properties and furthermore showed anisotropic adhesive properties without the need for tilt in the structures. These adhesives can be used to reversibly suspend weights from vertical surfaces (e.g., walls) and, for the first time to our knowledge, horizontal surfaces (e.g., ceilings) by simultaneously and judiciously activating anisotropic friction and adhesion forces. Furthermore, adhesion properties between artificial gecko-inspired dry adhesives and rough substrates with varying roughness are studied. The results suggest that both adhesion and friction forces on a rough substrate depends significantly on the

  12. Biological issues in materials science and engineering: Interdisciplinarity and the bio-materials paradigm

    Murr, L. E.

    2006-07-01

    Biological systems and processes have had, and continue to have, important implications and applications in materials extraction, processing, and performance. This paper illustrates some interdisciplinary, biological issues in materials science and engineering. These include metal extraction involving bacterial catalysis, galvanic couples, bacterial-assisted corrosion and degradation of materials, biosorption and bioremediation of toxic and other heavy metals, metal and material implants and prostheses and related dental and medical biomaterials developments and applications, nanomaterials health benefits and toxicity issue, and biomimetics and biologically inspired materials developments. These and other examples provide compelling evidence and arguments for emphasizing biological sicences in materials science and engineering curricula and the implementation of a bio-materials paradigm to facilitate the emergence of innovative interdisciplinarity involving the biological sciences and materials sciences and engineering.

  13. Corrosion behavior of Ti-13Nb-13Zr alloy used as a biomaterial

    Titanium alloys were developed as an alternative to stainless steels and have been extensively used as biomaterials ever since. One of these alloys is Ti-13Nb-13Zr (TNZ), a near-beta phase alloy containing elements with excellent biocompatibility. The main advantage of the TNZ alloy, compared to other titanium alloys, such as Ti-6Al-4V and Ti-6Al-7Nb, widely used as biomaterials, is its low elasticity modulus, closer to that of bone, and the absence of aluminum and vanadium, which have been reported to cause long-term adverse effects. In this paper, the corrosion and electrochemical behavior of TNZ alloy (as cast and after oxygen charge) was studied in a PBS solution. The results showed that, with the oxygen load, there is a significant reduction of the anodic current in almost the whole potential spam explored in this work, meaning that the corrosion rate decreases when the doping is performed.

  14. Subchondral Bone Regenerative Effect of Two Different Biomaterials in the Same Patient

    Marco Cavallo

    2013-01-01

    Full Text Available This case report aims at highlighting the different effects on subchondral bone regeneration of two different biomaterials in the same patient, in addition to bone marrow derived cell transplantation (BMDCT in ankle. A 15-year-old boy underwent a first BMDCT on a hyaluronate membrane to treat a deep osteochondral lesion (8 mm. The procedure failed: subchondral bone was still present at MRI. Two years after the first operation, the same procedure was performed on a collagen membrane with DBM filling the defect. After one year, AOFAS score was 100 points, and MRI showed a complete filling of the defect. The T2 mapping MRI after one year showed chondral tissue with values in the range of hyaline cartilage. In this case, DBM and the collagen membrane were demonstrated to be good biomaterials to restore subchondral bone: this is a critical step towards the regeneration of a healthy hyaline cartilage.

  15. Supracolloidal Assemblies as Sacrificial Templates for Porous Silk-Based Biomaterials

    John G. Hardy

    2015-08-01

    Full Text Available Tissues in the body are hierarchically structured composite materials with tissue-specific properties. Urea self-assembles via hydrogen bonding interactions into crystalline supracolloidal assemblies that can be used to impart macroscopic pores to polymer-based tissue scaffolds. In this communication, we explain the solvent interactions governing the solubility of urea and thereby the scope of compatible polymers. We also highlight the role of solvent interactions on the morphology of the resulting supracolloidal crystals. We elucidate the role of polymer-urea interactions on the morphology of the pores in the resulting biomaterials. Finally, we demonstrate that it is possible to use our urea templating methodology to prepare Bombyx mori silk protein-based biomaterials with pores that human dermal fibroblasts respond to by aligning with the long axis of the pores. This methodology has potential for application in a variety of different tissue engineering niches in which cell alignment is observed, including skin, bone, muscle and nerve.

  16. Biological Evaluation of ChuangYuLing Dressing-A Multifunctional Medicine Carrying Biomaterial

    PENG Rui; ZHENG Qixin; HAO Jie; ZOU Yang; CHENG Jie

    2005-01-01

    The safety of Chuangyuling (CYL) dressing-a multifunctional medicine carrying biomaterial was evaluated in order to provide foundation for the application of CYL as material used in the wound healing. The traditional Chinese medicine (TCM) extract solution was compounded with scaffolds (gelatin and Bletilla hyacinthine gum), and then frozen and dried to form spongy and porous material CYL. According to the standard of biological evaluation of medical devices that was instituted by the ministry of health of China[1] , the biological evaluation of CYL dressing was conducted. The results showed that all the contents of biological evaluation test consisting of acute toxicity, skin irritation, sensitization and cytotoxicity met the requirement of standards. It was concluded that the biomaterial carrying TCM (CYL dressing) is safe for application of wound healing.

  17. Nano-hydroxyapatite composite biomaterials for bone tissue engineering--a review.

    Venkatesan, Jayachandran; Kim, Se-Kwon

    2014-10-01

    In recent years, significant development has been achieved in the construction of artificial bone with ceramics, polymers and metals. Nano-hydroxyapatite (nHA) is widely used bioceramic material for bone graft substitute owing to its biocompatibility and osteoconductive properties. nHA with chitin, chitosan, collagen, gelatin, fibrin, polylactic acid, polycaprolactone, poly(lactic-co-glycolic) acid, polyamide, polyvinyl alcohol, polyurethane and polyhydroxybutyrate based composite scaffolds have been explored in the present review for bone graft substitute. This article further reviews the preparative methods, chemical interaction, biocompatibiity, biodegradation, alkaline phosphatase activity, mineralization effect, mechanical properties and delivery of nHA-based nanocomposites for bone tissue regeneration. The nHA based composite biomaterials proved to be promising biomaterials for bone tissue engineering. PMID:25992432

  18. Focal adhesions and cell-matrix interactions

    Woods, A; Couchman, J R

    1988-01-01

    Focal adhesions are areas of cell surfaces where specializations of cytoskeletal, membrane and extracellular components combine to produce stable cell-matrix interactions. The morphology of these adhesions and the components identified in them are discussed together with possible mechanisms of...

  19. Synthesis of melamine-glucose resin adhesive

    CHEN; Shuanhu; ZHANG; Lei

    2005-01-01

    The synthesis of a novel melamine-glucose adhesive that is similar to urea-formaldehyde adhesive is reported in this paper. The conditions of synthesis, such as the initial pH, the quantity of catalyst, the temperature of reaction, the percentage of each reactant and the time of reaction, were optimized by using the orthogonal experimental method.

  20. Adhesion force studies of nanofibers and nanoparticles.

    Xing, Malcolm; Zhong, Wen; Xu, Xiuling; Thomson, Douglas

    2010-07-20

    Surface adhesion between nanofibers and nanoparticles has attracted attention for potential biomedical applications, but the measurement has not been reported. Adhesion forces were measured using a polystyrene (PS) nanoparticle attached to an atomic force microscopy (AFM) tip/probe. Electrospun PS nanofibers of different diameters were tapped with the probe to study the effect of fiber diameters on adhesion force. Both AFM experiments and numerical models suggest that the adhesion force increases with increased fiber diameters. Numerical models further demonstrated that local deformation of the fiber surface, including the flattening of surface asperities and the nanofiber wrapping around the particle during contact, may have a significant impact on the adhesion force. The adhesion forces are in the order of 100 nN, much smaller than the adhesion forces of the gecko foot hair, but much larger than that of the receptor-ligand pair, antibody-antigen pair, and single-stranded DNA from a substrate. Adhesion forces of nanofibers with roughness were predicted by numerical analysis. This study is expected to provide approaches and information useful in the design of nanomedicine and scaffold based on nanofibers for tissue engineering and regenerative medicine. PMID:20552953

  1. Adhesion Between Poly(dimethylsiloxane) Layers

    Yu, Liyun; Daugaard, Anders Egede; Skov, Anne Ladegaard

    Different adhesion methods of poly(dimethylsiloxane) (PDMS) layers were studied with respect to adhesional force and the resulting rheology of the two-layered PDMS films were investigated. The role of adhesion between PDMS layers on the performances of two-layer structures was studied with peel...

  2. Mechanisms of temporary adhesion in benthic animals

    Dodou, D.; Breedveld, P.; Winter, J.C.F.; Dankelman, J.; Leeuwen, van J.L.

    2011-01-01

    Adhesive systems are ubiquitous in benthic animals and play a key role in diverse functions such as locomotion, food capture, mating, burrow building, and defence. For benthic animals that release adhesives, surface and material properties and external morphology have received little attention compa

  3. Evaluation of progestogens for postoperative adhesion prevention.

    Beauchamp, P J; Quigley, M M; Held, B

    1984-10-01

    Progesterone (P) has been shown to have potent antiinflammatory and immunosuppressive properties. Previous reports have suggested that the use of P decreases postoperative adhesion formation. To further evaluate the role of pharmacologic doses of progestogens in adhesion prevention, 42 mature New Zealand White rabbits underwent standardized injuries to the uterine horns, fimbriae, and pelvic peritoneum and received one of six treatments. Group S had intraperitoneal placement of normal saline (0.9%); group H received intraperitoneal placement of 32% dextran 70; group IM-P received intramuscular P-in-oil 10 days before and after laparotomy in addition to intraperitoneal saline; group IP-P had intraperitoneal placement of an aqueous P suspension; group DP received medroxyprogesterone acetate intraperitoneally; and group C received no intramuscular or intraperitoneal adhesion-prevention agents. The animals were sacrificed 6 weeks after laparotomy, and the adhesions were scored. Intraperitoneal saline (group S) significantly reduced the amount of adhesions when compared with the control group (C) (P less than 0.05). No significant difference was observed when group S was compared with group H. Intramuscular P added to saline (group IM-P) did not cause further reduction in adhesions when compared with group S. Both group IP-P and group DP had more adhesions than did group S (P less than 0.01). These data fail to support previous claims regarding adhesion prevention by the use of locally or parenterally administered progestogens. PMID:6237937

  4. Recurrent spinal adhesive arachnoiditis: a case report

    James Pitágoras de Mattos

    1988-03-01

    Full Text Available Spinal adhesive arachnoiditis is not an uncommon disease, usually having a monophasic course. We studied an atypical patient with recurrent spinal adhesive arachnoiditis nine years after intrathecal anesthesia and the first attack of the disease. Also noteworthy was the favorable evolution after surgery.

  5. Syndecans: synergistic activators of cell adhesion

    Woods, A; Couchman, J R

    1998-01-01

    Cell-surface proteoglycans participate in cell adhesion, growth-factor signalling, lipase activity and anticoagulation. Until recently, only the roles of the glycosaminoglycan chains were investigated. Now, with molecular characterization of several core proteins, the roles of each individual...... molecules modulating integrin-based adhesion....

  6. Adhesion mechanism of a gecko-inspired oblique structure with an adhesive tip for asymmetric detachment

    Sekiguchi, Yu; Takahashi, Kunio; Sato, Chiaki

    2015-12-01

    An adhesion model of an oblique structure with an adhesive tip is proposed by considering a limiting stress for adhesion to describe the detachment mechanism of gecko foot hairs. When a force is applied to the root of the oblique structure, normal and shear stresses are generated at contact and the adhesive tip is detached from the surface when reaching the limiting stress. An adhesion criterion that considers both the normal and shear stresses is introduced, and the asymmetric detachment of the oblique structure is theoretically investigated. In addition, oblique beam array structures are manufactured, and an inclination effect of the structure on the asymmetric detachment is experimentally verified.

  7. Effect of Hyaluronic Acid Incorporation Method on the Stability and Biological Properties of Polyurethane-Hyaluronic Acid Biomaterials

    Ruiz, Amaliris; Rathnam, Kashmila R.; Masters, Kristyn S.

    2013-01-01

    The high failure rate of small diameter vascular grafts continues to drive the development of new materials and modification strategies that address this clinical problem, with biomolecule incorporation typically achieved via surface-based modification of various biomaterials. In this work, we examined whether the method of biomolecule incorporation (i.e., bulk vs. surface modification) into a polyurethane (PU) polymer impacted biomaterial performance in the context of vascular applications. ...

  8. Bone tissue regeneration indento-alveolar surgery : clinical and experimental studies on biomaterials and bone graft substitutes

    Sahlin-Platt, Annika

    2011-01-01

    Pathological processes in the alveolar and facial bones can lead to bone loss that may not heal with complete regeneration. Biomaterials can be used to facilitate the healing process and/or as a bone substitute, but the mechanisms are not fully understood. Persistent leakage of bacteria/bacterial toxins, after root canal treatment, may lead to a residual bone defect. The healing is dependent on a placed dental biomaterial providing a tight seal. The composition of the filling material may als...

  9. Nanomechanics based investigation into interface -thermomechanics of collagen and chitin based biomaterials

    Qu, Tao; Tomar, Vikas

    2014-01-01

    From the biological/chemical perspective, interface concepts related to cell surface/synthetic biomaterial interface and extracellular matrix/biomolecule interface have wide applications in medical and biological technology. Some findings regarding interfaces controlling biological reactions are like surfaces provide high accessibility for reaction, high surface area geometries that can be created to enhance reaction turnover rates, unique organic microenvironments that can enhance specific a...

  10. Opportunities for biomaterials : economic, environmental and policy aspects along their life cycle

    Hermann, B.G.

    2010-01-01

    Little was known at the start of these studies regarding the environmental impacts of bulk chemicals production from biomass and whether they could be produced economically. We have therefore analysed the entire life cycle of biomaterials: the production of bio-based chemicals, the application of bio-based polymers in packaging and finally the waste treatment of biodegradable materials. Numerous bio-based chemicals offer economic opportunities, the extent of which depends on the prices of the...

  11. Micro- and Nanoengineering Approaches to Control Stem Cell-Biomaterial Interactions

    Dolatshahi-Pirouz, Alireza; Nikkhah, Mehdi; Kolind, Kristian; Dokmeci, Mehmet R.; Khademhosseini, Ali

    2011-01-01

    As our population ages, there is a greater need for a suitable supply of engineered tissues to address a range of debilitating ailments. Stem cell based therapies are envisioned to meet this emerging need. Despite significant progress in controlling stem cell differentiation, it is still difficult to engineer human tissue constructs for transplantation. Recent advances in micro- and nanofabrication techniques have enabled the design of more biomimetic biomaterials that may be used to direct t...

  12. Harnessing Biomaterials to Engineer the Lymph Node Microenvironment for Immunity or Tolerance

    Andorko, James I.; Hess, Krystina L.; Jewell, Christopher M.

    2014-01-01

    Nanoparticles, microparticles, and other biomaterials are advantageous in vaccination because these materials provide opportunities to modulate specific characteristics of immune responses. This idea of “tuning” immune responses has recently been used to combat infectious diseases and cancer, and to induce tolerance during organ transplants or autoimmune disease. Lymph nodes and other secondary lymphoid organs such as the spleen play crucial roles in determining if and how these responses dev...

  13. Molecular interactions in biomineralized hydroxyapatite amino acid modified nanoclay: In silico design of bone biomaterials

    A simulations driven approach to design of a novel biomaterial nanocomposite system is described in this study. Nanoclays modified with amino acids (OMMT) were used to mineralize hydroxyapatite (HAP), mimicking biomineralization. Representative models of organically modified montmorillonite clay (OMMT) and OMMT-hydroxyapatite (OMMT-HAP) were constructed using molecular dynamics and validated using X-ray Diffraction (XRD), Fourier Transforms Infrared (FTIR) spectroscopy and Transmission Electron Microscopy (TEM). Attractive interactions exist between Ca atoms of HAP and C=O group of aminovaleric acid, indicating chelate formation in OMMT-HAP. Interaction energy maps describe molecular interactions among different constituents and their quantitative contributions in the OMMT and OMMT-HAP systems at both parallel and perpendicular orientations. High attractive and high repulsive interactions were found between PO43− and MMT clay as well as aminovaleric molecules in OMMT-HAP perpendicular and parallel models. Large non-bonded interactions in OMMT-HAP indicate influence of neighboring environment on PO43− in in situ HAPclay. Extensive hydrogen bonds were observed between functional hydrogen atoms of modifier and MMT clay in OMMT-HAP as compared to OMMT. Thus, HAP interacts with clay through the aminovaleric acid. This computational study provides a framework for materials design and selection for biomaterials used in tissue engineering and other areas of regenerative medicine. - Highlights: • Representative models of a hybrid nanoclay-hydroxyapatite biomaterial are built. • Interaction energy maps are constructed using a molecular dynamics. • Quantitative interactions between the three components of the biomaterial are found. • The modeling and experimental approach provides insight into the complex nanomaterial

  14. Thermal analysis of used and radiation treated polycarbonate (L-MW) biomaterial

    γ-radiation treatment of radiation sterilized polycarbonate biomaterials has been carried out to ensure efficient disposal by incineration. Low molecular weight polycarbonate sterilized with 2.5 Mrad dose of γ-radiation was further treated with different doses of γ-radiation. The radiation-treated samples were subjected to thermogravimetry. The sterilized sample and the 7.5 Mrad-treated sample showed similar properties. These samples do not leave any residue during thermal decomposition. (author). 5 refs., 3 tables

  15. Biomaterial aspects: A key factor in the longevity of implant overdenture attachment systems

    Daou, Elie E.

    2015-01-01

    Background: New attachment systems are released for mandibular two-implant overdentures often without evidence-based support. Biomaterial aspects are now the parameters considered when choosing the appropriate attachment. Studies regarding their properties remain scarce. Purpose: The purpose of this review was to help the clinician in selrcting the most adapted stud attachments according evidence-based dentistry. Materials and Methods: An electronic search was conducted using specific databas...

  16. ¬Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell Behaviour

    Hilary Jane Anderson; Matthew John Dalby; Jugal eSahoo; Rein eUljin

    2016-01-01

    Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell BehaviourHilary J Anderson1, Jugal Kishore Sahoo2, Rein V Ulijn2,3, Matthew J Dalby1*1 Centre for Cell Engineering, University of Glasgow, Glasgow, UK.2 Technology and Innovation centre, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK. 3 Advanced Science Research Centre (ASRC) and Hunter College, City University of New York, NY 10031, NY, USA. Correspondence:*Hilary Andersonh.anderson...

  17. Solvent Composition is Critical for Carbodiimide Cross-Linking of Hyaluronic Acid as an Ophthalmic Biomaterial

    Jui-Yang Lai

    2012-01-01

    Hyaluronic acid (HA) is one of the most important ophthalmic biomaterials, while also being used for tissue engineering and drug delivery. Although chemical cross-linking is an effective way to improve the material performance, it may as a consequence be detrimental to the living cells/tissues. Given that the cross-linking efficiency is mediated by the solvent composition during the chemical modification, this study aims to explore the stability and biocompatibility of carbodiimide cross-link...

  18. Scanning electrochemical microscopy of metallic biomaterials: reaction rate and ion release imaging modes.

    Gilbert, J L; Smith, S M; Lautenschlager, E P

    1993-11-01

    The Scanning Electrochemical Microscope (SECM) is a nonoptical scanning microscopic instrument capable of imaging highly localized electrical currents associated with charge transfer reactions on metallic biomaterials surfaces. The SECM operates as an aqueous electrochemical cell under bipotentiostatic control with a microelectrode and sample independently biased as working electrodes. Microelectrode current and position is recorded as it is scanned very near a metallurgically polished planar sample surface. To date, the SECM has imaged metallic biomaterials surfaces in oxygen reaction rate imaging (ORRI) and ion release and deposition imaging (IRDI) modes. In ORRI, sample and microelectrode are biased at sufficiently negative potentials to reduce absorbed oxygen. As the microelectrode scans areas of active oxygen reduction, localized diffusion fields with decreased oxygen solution concentrations are encountered and resultant decrements in microelectrode current are observed. In IRDI mode the sample is positively biased and the microelectrode is negatively biased. The microelectrode detects anodic dissolution products with highest currents being observed over the most active areas. Performance of the SECM has been evaluated on Ni minigrids, gamma-1 Hg-Ag dental amalgam crystals, and sintered beads of Co-Cr-Mo alloy which represent significantly different geometries and corrosion processes to help demonstrate the potential of this instrument. The SECM is a valuable tool for imaging microelectrochemical processes on the surfaces of metallurgically polished metallic biomaterials samples and a wide variety of other surfaces of biological interest where charge transfer reactions occur. The SECM allows selective biasing of metallic biomaterials surfaces and Faradaic reactions can be selectively imaged while the surface is in the active, passive, or transpassive state. PMID:8262998

  19. Biomaterial design for specific cellular interactions: Role of surface functionalization and geometric features

    Kolhar, Poornima

    The areas of drug delivery and tissue engineering have experienced extraordinary growth in recent years with the application of engineering principles and their potential to support and improve the field of medicine. The tremendous progress in nanotechnology and biotechnology has lead to this explosion of research and development in biomedical applications. Biomaterials can now be engineered at a nanoscale and their specific interactions with the biological tissues can be modulated. Various design parameters are being established and researched for design of drug-delivery carriers and scaffolds to be implanted into humans. Nanoparticles made from versatile biomaterial can deliver both small-molecule drugs and various classes of bio-macromolecules, such as proteins and oligonucleotides. Similarly in the field of tissue engineering, current approaches emphasize nanoscale control of cell behavior by mimicking the natural extracellular matrix (ECM) unlike, traditional scaffolds. Drug delivery and tissue engineering are closely connected fields and both of these applications require materials with exceptional physical, chemical, biological, and biomechanical properties to provide superior therapy. In the current study the surface functionalization and the geometric features of the biomaterials has been explored. In particular, a synthetic surface for culture of human embryonic stem cells has been developed, demonstrating the importance of surface functionalization in maintaining the pluripotency of hESCs. In the second study, the geometric features of the drug delivery carriers are investigated and the polymeric nanoneedles mediated cellular permeabilization and direct cytoplasmic delivery is reported. In the third study, the combined effect of surface functionalization and geometric modification of carriers for vascular targeting is enunciated. These studies illustrate how the biomaterials can be designed to achieve various cellular behaviors and control the

  20. Zirconia as a biomaterial for odontological applications : effects of composition and manufacturing processes on fracture resistance

    Sundh, Anders

    2010-01-01

    Background: Ceramics have long been amongst the most biocompatible materials known but their mechanical properties have limited their use. During the past few decades zirconia has aroused particular interest as a biomaterial because of its greater flexural strength, fracture resistance and toughness compared to other bioceramics. Technological inventions and developments have made the processing of zirconia-based ceramics possible and thus also the successful processing of dental restorations...