Surface properties and processes of the biomaterial-tissue interface (original) (raw)

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Modern biomaterials: a review—bulk properties and implications of surface modifications

Journal of Materials Science: Materials in Medicine, 2007

This review concerns the importance of length and time on physicochemical interactions between living tissue and biomaterials that occur on implantation. The review provides information on material host interactions, materials for medical applications and cell surface interactions, and then details the extent of knowledge concerning the role(s) that surface chemistry and topography play during the first stage of implant integration, namely protein adsorption. The key points are illustrated by data from model in vitro studies. Host implant interactions begin nanoseconds after first contact and from then on are in a state of flux due to protein adsorption, cell adhesion and physical and chemical alteration of the implanted material. The many questions concerning the conformational form and control of bound proteins and how this may impact on cell adhesion in the first instance and later on cell signalling and implant integration can be answered by systematic investigations using model materials. Only then we will be in a more informed position to design new materials for use in the body.

Surface Characterization in Biomaterials Applications

2008

Applications biomaterials are illustrated as examples of functionalized surfaces in the growing field of synthetic materials for medical applications. After a brief introduction into the main surface analytical tools such as X-ray photoelectron spectroscopy (XPS), Time-of-flight secondary ion mass spectrometry (TofSIMS) and contact angle measurements two examples, endotracheal tubes for with anti-bacterial characteristics and the preparation of neural biochips are chosen to illustrate recent achievements.

Surface modification and chemical surface analysis of biomaterials

Current Opinion in Chemical Biology, 2011

The chemical composition of the surface layers of synthetic biomaterials used for human medical devices and in biotechnology plays a key role in determining interfacial interactions between biological media (such as protein solutions, cells, tissue) and the synthetic material. Accordingly, considerable research efforts focus on improving the 'biocompatibility' of biomaterials by applying various surface modification and thin film coating approaches. Here we focus on the patterning of surface chemistries, often designed to exercise spatial control over events such as cell attachment and spreading. Secondly, we review recent developments in chemical characterisation of biomaterials surfaces, which is essential both for verifying the success of intended surface modification strategies and for reliable interpretation of observed biological responses. Biomaterials surface analysis by imaging ToF-SIMS and XPS and compositional depth profiling are discussed, as is the emerging complementary technique of Metastable Induced Electron Spectroscopy.

In vitro testing of surface-modified biomaterials

Journal of Materials Science: Materials in Medicine, 1998

The influence of surface modification treatments such as ion implantation and sputter coating on an in vitro rat bone-marrow cell culture was studied by scanning electron microscopy and X-ray microanalysis. 316 L stainless steel, Ti-6Al-4V and Ti-5Al-2.5Fe were nitrogen ion-implanted with three fluences: 10 15 , 10 16 and 10 17 ion cm !2 with an energy beam of 40 keV. Both nitrogen and carbon sputter-coated 316 L stainless steel samples were also studied. Polished 316 L stainless steel, Ti-6Al-4V, Ti-5Al-2.5Fe and Thermanox TM were also studied, in order to give comparative information. The materials were inoculated with a droplet of cell suspension and were maintained for 3 wk. A mineralized extracellular matrix was formed on all materials except on nitrogen sputter-coated 316 L stainless steel. The morphology of the cell cultures obtained on nitrogen-ion implanted materials was similar to those obtained on the untreated materials and Thermanox TM . The observation of the interface between the cell layer and the substrata showed the presence of calcium-and phosphorus-rich globular deposits associated with collagen fibres. A higher density of these globular deposits was observed on the ion-implanted materials.

Surface Chemistry Influence Implant Biocompatibility

2008

Implantable medical devices are increasingly important in the practice of modern medicine. Unfortunately, almost all medical devices suffer to a different extent from adverse reactions, including inflammation, fibrosis, thrombosis and infection. To improve the safety and function of many types of medical implants, a major need exists for development of materials that evoked desired tissue responses. Because implant-associated protein adsorption and conformational changes thereafter have been shown to promote immune reactions, rigorous research efforts have been emphasized on the engineering of surface property (physical and chemical characteristics) to reduce protein adsorption and cell interactions and subsequently improve implant biocompatibility. This brief review is aimed to summarize the past efforts and our recent knowledge about the influence of surface functionality on protein:cell:biomaterial interactions. It is our belief that detailed understandings of bioactivity of surface functionality provide an easy, economic, and specific approach for the future rational design of implantable medical devices with desired tissue reactivity and, hopefully, wound healing capability.

Material-Tissue Interfaces: The Role of Surface Properties and Processes

Environmental Health Perspectives, 1994

The introduction of a foreign material into living tissue-intentionally as in biomedical applications (implants, protheses, drugs) or unintentionally as when minerals or fibers are inhaled-results in the creation of interfaces between the rpaterial and the surrounding tissue. This article identifies and discusses the possible role of material surface properties and molecular processes occurring at such interfaces. For kinetic and thermodynamic reasons, surfaces are different from the corresponding bulk of the material, and contain reactive (unsaturated) bonds, which in turn lead to the formation of surface reactive layers (e.g., surface oxides on metals) and adsorbed contamination layers. The encounter with the biological environment leads to further surface reactions modifying the surface, and to the adsorption of water, ions, and biomolecules, which are continuously exchanged. The exact nature of the dynamic, adsorbed water, ions, and biomolecule coating in turn influences the behavior of cells approaching the material surface, and hence the tissue response. -Environ Health Perspect 102(Suppl 5): 41-45 (1994)

Surface Chemistry Influences Implant Biocompatibility

Current Topics in Medicinal Chemistry, 2008

Implantable medical devices are increasingly important in the practice of modern medicine. Unfortunately, almost all medical devices suffer to a different extent from adverse reactions, including inflammation, fibrosis, thrombosis and infection. To improve the safety and function of many types of medical implants, a major need exists for development of materials that evoked desired tissue responses. Because implant-associated protein adsorption and conformational changes thereafter have been shown to promote immune reactions, rigorous research efforts have been emphasized on the engineering of surface property (physical and chemical characteristics) to reduce protein adsorption and cell interactions and subsequently improve implant biocompatibility. This brief review is aimed to summarize the past efforts and our recent knowledge about the influence of surface functionality on protein:cell:biomaterial interactions. It is our belief that detailed understandings of bioactivity of surface functionality provide an easy, economic, and specific approach for the future rational design of implantable medical devices with desired tissue reactivity and, hopefully, wound healing capability.

Ion Beam Surface Treatment of Biomatenals

orthopedics and dentistry. The selection is limited to some Systems: Ti, Ti alloys, stainless steels, Co alloys, alumina, zirconia, carbon and ultrahigh molecular weight polyethylene [l], for reasons of compromising various requirements. The selection criteria are dictated by two global aspects of biofunctionaliy and biocompatibility 121. Ability for load bearing, fracture resistance, modulus of elasticity or fatigue resistance are e.g. some elements of the required biofunctionality, which are reasonably pertinent volume properties of the material. But the interactions that occur when foreign biomaterials come into contact with the biological environment, are of superficial and interfacial nature, and the surface and subsurface properties of the material are the factors that determine such events. A vast majority of complications and failures in clinical use of biomaterials is related to this phenomenon of biocompatibility.

Surface chemistry influences implant‐mediated host tissue responses

Journal of Biomedical Materials Research Part A, 2008

Implant-mediated fibrotic reactions are detrimental to the performance of encapsulated cells, implanted drug release devices and sensors. To improve the implant function and longevity, research has emphasized altering cellular responses. Although material surface functional groups have been shown to be potent in affecting cellular activity in vitro and short term in vivo responses, these groups appear to have little influence on long-term in vivo fibrotic reactions, possibly as a result of insufficient interactions between recruited host cells and functional groups on the implants. To maximize the influence of functionality on cells, and to mimic drug release microspheres, functionalized micron-sized particles were created and tested for their ability in modulating tissue responses to biomaterial implants. In this work, the surfaces of polypropylene particles were controllably coated with four different functional groups, specifically -OH, -NH 2 , -CF x and -COOH, using a radio frequency glow discharge plasma polymerization technique. The effect of these surface functionalities on host tissue responses were then evaluated using a mice subcutaneous implantation model. Major differences were observed in contrasting tissue response to the different chemistries. Surfaces with -OH and -NH 2 surface groups induced the thickest fibrous capsule accompanied with the greatest cellular infiltration into the implants. In contrast, surfaces with -CF x and -COOH exhibited the least inflammatory/fibrotic responses and cellular infiltrations. The present results clearly demonstrate that, by increasing the available functionalized surface area and spatial distribution, the effect of surface chemistry on tissue reactivity can be substantially enhanced.

Biomaterials: Role of surface modifications

Bulletin of Materials Science, 1994

The fundamental concepts related to biomaterials and blood/tissue-material interactions at the interface have been reviewed. The relevance of surface modification to enhance blood and/or tissue compatibility of materials has been discussed and its role in selected prosthetic applications described.