1,721,096 research outputs found
Synthetic surgical meshes used in abdominal wall surgery: Part I-materials and structural conformation
No full textSurgical implants are commonly used in abdominal wall surgery for hernia repair. Many different prostheses are currently offered to surgeons, comprising permanent synthetic polymer meshes and biologic scaffolds. There is a wide range of synthetic meshes currently available on the market with differing chemical compositions, fiber conformations, and mesh textures. These chemical and structural characteristics determine a specific biochemical and mechanical behavior and play a crucial role in guaranteeing a successful post-operative outcome. Although an increasing number of studies report on the structural and mechanical properties of synthetic surgical meshes, nowadays there are no consistent guidelines for the evaluation of mechanical biocompatibility or common criteria for the selection of prostheses. The aim of this work is to review synthetic meshes by considering the extensive bibliography documentation of their use in abdominal wall surgery, taking into account their material and structural properties, in Part I, and their mechanical behavior, in Part II. The main materials available for the manufacture of polymeric meshes are described, including references to their chemical composition, fiber conformation, and textile structural properties. These characteristics are decisive for the evaluation of mesh-tissue interaction process, including foreign body response, mesh encapsulation, infection, and adhesion formation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2015
Numerical modeling of the abdominal wall biomechanics and experimental analysis for model validation
Get PDFThe evaluation of the biomechanics of the abdominal wall is particularly important to understand the onset of pathological conditions related to weakening and injury of the abdominal muscles. A better understanding of the biomechanics of the abdominal wall could be a breakthrough in the development of new therapeutic approaches. For this purpose, several studies in the literature propose finite element models of the human abdomen, based on the geometry of the abdominal wall from medical images and on constitutive formulations describing the mechanical behavior of fascial and muscular tissues. The biomechanics of the abdominal wall depends on the passive mechanical properties of fascial and muscle tissue, on the activation of abdominal muscles, and on the variable intra-abdominal pressure. To assess the quantitative contribution of these features to the development and validation of reliable numerical models, experimental data are fundamental. This work presents a review of the state of the art of numerical models developed to investigate abdominal wall biomechanics. Different experimental techniques, which can provide data for model validation, are also presented. These include electromyography, ultrasound imaging, intraabdominal pressure measurements, abdominal surface deformation, and stiffness/compliance measurements
Correlation between chemical and mechanical properties in renewable poly(ether-block-amide)s for biomedical applications
No full textEvaluation of the mechanical behaviour of Telemark ski boots: Part I - materials characterization in use conditions
No full textThis study reports the first part of the analysis for the evaluation of the mechanical behaviour of ski boots by means of an integrated approach that considers polymeric materials characterization, in Part I, and numerical structural analysis, in Part II. In the present Part I, different techniques are adopted to characterize the mechanical behaviour of the polymeric materials used for ski boots, to define the elastic, visco-elastic, temperature and weathering-dependent characteristics. Experimental data provide fundamental information on mechanical response, in particular taking into account the effect of the environmental conditions, due to temperature variation, ultraviolet radiation and water absorption, which are correlated to the definition of reliability and durability of the materials. In more detail, experimental results from tensile tests and dynamic mechanical analysis are reported, evaluating mechanical response and chemical conformation of the polymers. Materials properties are correlated with the specific use conditions and boot structure, to be able to evaluate and preserve overall performances and general safety requirements of ski boots. This activity represents a reference procedure for the evaluation of the material mechanical behaviour that must be considered within the structural analysis
Biomaterials and Their Biomedical Applications: From Replacement to Regeneration
Get PDFThe history of biomaterials dates back to the mists of time: human beings had always used exogenous materials to facilitate wound healing and try to restore damaged tissues and organs.
Nowadays, a wide variety of materials are commercially available and many others are under investigation to both maintain and restore bodily functions. Emerging clinical needs forced the development of new biomaterials, and lately discovered biomaterials allowed for the performing of new clinical applications. The definition of biomaterials as materials specifically conceived for biomedical uses was raised when it was acknowledged that they have to possess a fundamental feature: biocompatibility. At first, biocompatibility was mainly associated with biologically inert substances; around the 1970s, bioactivity was first discovered and the definition of biomaterials was consequently extended. At present, it also includes biologically derived materials and biological tissues. The present work aims at walking across the history of biomaterials, looking towards the scientific literature published on this matter. Finally, some current applications of biomaterials are briefly depicted and their future exploitation is hypothesized
Effect of steam on the structural and morphological stability of renewable poly(ether-block-amide)s
No full text- …
