Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Cell membrane-inspired phospholipid polymers for developing medical devices with excellent biointerfaces  [cached]
Yasuhiko Iwasaki,Kazuhiko Ishihara
Science and Technology of Advanced Materials , 2012,
Abstract: This review article describes fundamental aspects of cell membrane-inspired phospholipid polymers and their usefulness in the development of medical devices. Since the early 1990s, polymers composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) units have been considered in the preparation of biomaterials. MPC polymers can provide an artificial cell membrane structure at the surface and serve as excellent biointerfaces between artificial and biological systems. They have also been applied in the surface modification of some medical devices including long-term implantable artificial organs. An MPC polymer biointerface can suppress unfavorable biological reactions such as protein adsorption and cell adhesion – in other words, specific biomolecules immobilized on an MPC polymer surface retain their original functions. MPC polymers are also being increasingly used for creating biointerfaces with artificial cell membrane structures.
Bioinspired Sensor Systems  [PDF]
Manel del Valle
Sensors , 2011, DOI: 10.3390/s111110180
Abstract: This editorial summarizes and classifies the contributions presented by different authors to the special issue of the journal Sensors dedicated to Bioinspired Sensor Systems. From the coupling of sensor arrays or networks, plus computer processing abilities, new applications to mimic or to complement human senses are arising in the context of ambient intelligence. Principles used, and illustrative study cases have been presented permitting readers to grasp the current status of the field.
Salve Journal of Functional Biomaterials, ad maiòra!  [PDF]
Francesco Puoci
Journal of Functional Biomaterials , 2010, DOI: 10.3390/jfb1010001
Abstract: The biomaterials field is one of the largest and fastest growing research areas both in the scientific community and in the industrial one. Biomaterials are the result of collaborations between different disciplines: chemistry, medicine, pharmacology, engineering and biology. The objective of this collaboration is to lead to the implementation of new devices to restore form and human body functions. The research on biomaterials reflects the constant need to replace or supplement human tissues and organs that have been physiologically compromised due to disease or traumatic events. [...]
Natural Products: A Minefield of Biomaterials  [PDF]
Oladeji O. Ige,Lasisi E. Umoru,Sunday Aribo
ISRN Materials Science , 2012, DOI: 10.5402/2012/983062
Abstract: The development of natural biomaterials is not regarded as a new area of science, but has existed for centuries. The use of natural products as a biomaterial is currently undergoing a renaissance in the biomedical field. The major limitations of natural biomaterials are due to the immunogenic response that can occur following implantation and the lot-to-lot variability in molecular structure associated with animal sourcing. The chemical stability and biocompatibility of natural products in the body greatly accounts for their utilization in recent times. The paper succinctly defines biomaterials in terms of natural products and also that natural products as materials in biomedical fields are considerably versatile and promising. The various types of natural products and forms of biomaterials are highlighted. Three main areas of applications of natural products as materials in medicine are described, namely, wound management products, drug delivery systems, and tissue engineering. This paper presents a brief history of natural products as biomaterials, various types of natural biomaterials, properties, demand and economic importance, and the area of application of natural biomaterials in recent times. 1. Introduction A biomaterial is regarded as any nondrug material that can be used to treat, enhance or replace any tissue, organ, or function in an organism [1]. While the definition of biomaterial was reframed as a nondrug substance suitable for inclusion in systems which augment or replace the function of bodily tissues or organs [2]. This definition explicitly described biomaterial in relation to drugs and as such, there is a need to clarify the impression that natural products are synonymous with drugs. The definition implies that natural products can be applied as biomaterials by eliminating the ambiguity always associated with natural products as drugs. It must be emphasized that this definition is not regarded as one of the most popular and is not often cited as this one which defines biomaterial as a nonviable material that intends to interact with physiological environment [3]. However, in this study, the following definition will be adopted: biomaterial can be defined as any substance (other than a drug) or combination of substances synthetic or natural in origin, which can be used any time, as a whole or as a part of a system which treats, augments, or replaces any tissue, organ or function of the body [4]. It must be noted that in this study the substances are natural in origin. 1.1. Economy The field of biomaterials working under biological
Handbook of bioinspired algorithms and applications
Max E Valentinuzzi
BioMedical Engineering OnLine , 2006, DOI: 10.1186/1475-925x-5-47
Abstract: Many years ago, the term Bionics (now forgotten) was coined, meaning the inverse process, that is, application of knowledge taken from the Biological Sciences to solve or help in the solution of problems of Engineering practice at large, or simply to get ideas based in the former sciences. Traditional early examples frequently mentioned in the literature to illustrate the point were the snakes' infrared sensors and the ultrasound dolphin emissions used, respectively, to locate a prey and for orientation, as animal inspiration for their military similar counterparts.Well, this dense handbook falls within the latter concept, as anticipated in its title by the word "bioinspired". Thus, it is quite pertinent to directly quote from the Preface: "The Handbook seeks to provide an opportunity for researchers to explore the connection between biologically inspired techniques and the development of solutions to problems that arise in a variety of problem domains." Enrique Alba and Carlos Cotta, from Málaga, Spain, ask in Chapter 1, on "Evolutionary Algorithms", if we can learn, and use for our own profit, the lessons taught by Nature. They declare themselves strongly for the affirmative and define as evolutionary algorithms a collection of optimization techniques whose functioning is loosely based on metaphors of biological processes. Clearly, at the very outset, authors state what the potential reader might expect and whom the content is addressed to.Section I, devoted to Models and Paradigms, takes about one fourth of the book (175 pages out of a total of 663), while Section II deals with Applications and Domains, although the division is not really very much clear-cut as a certain degree of overlapping between the two is easily detected. Somewhat arbitrarily, I selected a few chapters to briefly comment about for they appeared to me as rather appealing. However, it does not mean that the others are not. Besides, a book of this size and scope supersedes a full detailed desc
Low cholesteryl ester transfer protein and phospholipid transfer protein activities are the factors making tree shrew and beijing duck resistant to atherosclerosis
Hui-rong Liu, Gang Wu, Bing Zhou, Bao-sheng Chen
Lipids in Health and Disease , 2010, DOI: 10.1186/1476-511x-9-114
Abstract: Blood samples were collected from healthy men and male animals. Plasma lipid profile and activities of cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) were measured, compared and analyzed in human, tree shrew, and Beijing duck.The results showed that there were species differences on plasma lipid profile and activities of CETP and PLTP in the three species. Compared with human, tree shrew and beijing duck had higher high density lipoprotein cholesterol (HDL-C)/total cholesterol (TC) and HDL-C/low density lipoprotein cholesterol (LDL-C) ratios, but lower CETP and PLTP activities. In the three species, CETP and PLTP activities were negatively related with the ratio of HDL-C/LDL-C.The present study suggested that low plasma CETP and PLTP activities may lead to a high HDL-C/LDL-C ratio and a high resistance to AS finally in tree shrew and beijing duck. Moreover, low PLTP activity may also make the animals resistant to AS by the relative high vitamin E content of apoB-containing lipoproteins and high anti-inflammatory and antioxidative properties of HDL particles. A detailed study in the future is recommended.Cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) are two important factors to transfer lipids in lipoprotein metabolism. CETP transfers cholesteryl ester from high density lipoprotein (HDL) to lipoproteins of lower density, partly in exchange for triglycerides. PLTP promotes the transfer of phospholipids and free cholesterol between lipoproteins [1,2]. It is reported that CETP and PLTP activities are closely related to atherosclerosis (AS) [1,2].Some vertebrate species can be defined as two distinct groups with low or high atherosclerosis susceptibility [3]. Cat, dog, mouse and rat belong to the 'resistant' group, while chicken, pig, rabbit and man belong to the 'susceptible' group. It is showed that plasma lipids transfer activities are significantly different between the two groups, which exert d
Bioinspired Poly(2-oxazoline)s  [PDF]
Richard Hoogenboom,Helmut Schlaad
Polymers , 2011, DOI: 10.3390/polym3010467
Abstract: Poly(2-oxazoline)s are regarded as pseudopeptides, thus bioinspired polymers, due to their structural relationship to polypeptides. Materials and solution properties can be tuned by varying the side-chain (hydrophilic-hydrophobic, chiral, bioorganic, etc.), opening the way to advanced stimulus-responsive materials and complex colloidal structures. The bioinspired “smart” solution and aggregation behavior of poly(2-oxazoline)s in aqueous environments are discussed in this review.
Graded/Gradient Porous Biomaterials  [PDF]
Xigeng Miao,Dan Sun
Materials , 2010, DOI: 10.3390/ma3010026
Abstract: Biomaterials include bioceramics, biometals, biopolymers and biocomposites and they play important roles in the replacement and regeneration of human tissues. However, dense bioceramics and dense biometals pose the problem of stress shielding due to their high Young’s moduli compared to those of bones. On the other hand, porous biomaterials exhibit the potential of bone ingrowth, which will depend on porous parameters such as pore size, pore interconnectivity, and porosity. Unfortunately, a highly porous biomaterial results in poor mechanical properties. To optimise the mechanical and the biological properties, porous biomaterials with graded/gradient porosity, pores size, and/or composition have been developed. Graded/gradient porous biomaterials have many advantages over graded/gradient dense biomaterials and uniform or homogenous porous biomaterials. The internal pore surfaces of graded/gradient porous biomaterials can be modified with organic, inorganic, or biological coatings and the internal pores themselves can also be filled with biocompatible and biodegradable materials or living cells. However, graded/gradient porous biomaterials are generally more difficult to fabricate than uniform or homogenous porous biomaterials. With the development of cost-effective processing techniques, graded/gradient porous biomaterials can find wide applications in bone defect filling, implant fixation, bone replacement, drug delivery, and tissue engineering.
Classification of Biomaterials used in Medicine  [cached]
Patitapabana Parida,Ajit Behera,Subash Chandra Mishra
International Journal of Advances in Applied Sciences , 2012, DOI: 10.11591/ijaas.v1i3.882
Abstract: In this decade many researches are potentially going forward by using biomaterials in the medical field. Biomaterials can used in living creature body, taking in account of there biocompatibility. This paper describes about classification of different biomaterials which are used in medical industries. Advances in surgical technique and instruments have permitted materials to be used in ways that were not possible previously. Bio-material can partially/totally replaces one or more part of the body. Before using biomaterials, it should in mind that, which categories they are belongs and main focuses are on biocompatibility, bioinert, bioactive/surface reactive, biodegradable, sterilizability, adequate mechanical and physical properties, manufacturability, low weight, reasonable cost etc. It is necessary to classify biomaterials for there suitable use in medical industries.
Musculoskeletal Regenerative Engineering: Biomaterials, Structures, and Small Molecules  [PDF]
Roshan James,Cato T. Laurencin
Advances in Biomaterials , 2014, DOI: 10.1155/2014/123070
Abstract: 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 volumes and multi-level tissues such as complex organ systems integrated into a single phase require more than optimal combinations of biomaterials and biologics. We highlight bioinspired advancements leading to novel regenerative scaffolds especially for musculoskeletal tissue repair and regeneration. Tissue and organ regeneration relies on the spatial and temporal control of biophysical and biochemical cues, including soluble molecules, cell-cell contacts, cell-extracellular matrix contacts, and physical forces. Strategies that recapitulate the complexity of the local microenvironment of the tissue and the stem cell niche play a crucial role in regulating cell self-renewal and differentiation. Biomaterials and scaffolds based on biomimicry of the native tissue will enable convergence of the advances in materials science, the advances in stem cell science, and our understanding of developmental biology. 1. Introduction Incidents of tissue loss or organ failure due to accidents, injuries, and disease are debilitating and have led to increased health care costs the world over [1]. Current standard of care includes organ and tissue transplantation, allografts, biofactors, and replacements composed of metals, polymers, and ceramics. However, each strategy suffers from a number of?limitations. For example, autografts and allografts are often associated with limited availability and risks of immunogenicity, respectively. Tissue engineering was developed as an alternative strategy to repair and regenerate living tissues and to provide a viable tissue substitute. Bioengineer Fung first proposed the term “tissue engineering” at a 1987 meeting of the National Science Foundation [2], where it was defined as the use of isolated cells or cell substitutes, tissue-inducing substances, and cells placed on or in matrices to repair and regenerate tissue [3, 4]. Early medical devices were physician-driven and made using off-the-shelf materials such as Teflon, high-density polyethylene, poly(methyl methacrylate), stainless steel, polyurethane, titanium, and silicone elastomers. Over the
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.