Papers by Keyword: Biocompatible Material

Abstract: The first polycaprolactone material experimental and clinical studies were published in 1960-1970, which proved its biocompatibility and determined the absence of toxic properties. At the same time it did not receive widespread use due to insufficient rigidity and strength compared to metal implants. For a long time, relatively solid materials were used to treat injuries to the musculoskeletal system segments. The progress in materials science, development of new sterilization methods has again changed the attitude towards biomaterial implants and has attracted the attention of clinicians. In this regard, the development of predictive modeling methods to determine effective mechanical properties and optimal geometric structure of porous biomedical materials is an important task. Modeling the internal architecture of porous materials and their properties by the finite element method using computed tomography data is as close as possible to the real picture, but it is quite laborious to apply directly to large-sized scaffolds. Properties of such materials largely depend on the technology of their manufacture and processing, the geometric dimensions and cell shape. In this regard, the development and improvement of analytical methods for assessing properties of cellular structures remains relevant. The aim of this study is determining polycaprolactone effective elastic modulus based on modified Gibson-Ashby open-cell model as an implant material and osteochondral defects treatment. A practical analytical method for estimating the elastic modulus of a cellular material regardless of the scaffold volume and shape is proposed. Calculations are performed for polycaprolactone produced using selective laser sintering technology. A comparative analysis of the obtained results with experimental studies of other authors is carried out. The results can be used for evaluation analysis and calculations of medical devices strength and stiffness made of porous polycaprolactone for the bone defects treatment.

Abstract: To improve the quality of human life, sometimes, surgical interventions are required to replace or retain damaged tissue during reparative regeneration. Titanium and titanium alloys are well-proven biocompatible materials. The methods of modeling the phase composition of the titanium alloy can be used to predict the chemical and physical-mechanical properties of implants and suture material. In this research, the features of the titanium drawing process are investigated, recommendations are given for thermo-mechanical processing and the choice of a lubricant. Modeling the structure and phase composition of alloys allows predicting their properties and choosing the optimal technological parameters for all drawing transitions. Drawing must be performed in a friction mode close to the hydrodynamic regime with intermediate annealing to control the phase composition of titanium, restore the plasticity resource, and heal crystal structure defects. The composition of atmospheric gases during annealing makes it possible to control the phase composition and properties of the alloy. The use of exfoliated graphite is proposed as a lubricant applied to the anodized titanium surface.

Abstract: Mg-Ca-Zn alloys are promising candidate metal cellular material for biocompatible and biodegradable implant. This is due to its corrosion behavior which enables well controlled degradation, as well as due to the fact that the corrosion product shows no cytotoxicity at all. In this present work, the characteristics of Mg-Ca-Zn alloy metallic foam prepared by the foaming of a powder compact based on Mg-2Zn-Ca and CaH₂ system were investigated. Mg-Zn-CaH₂ powders with various compositions of 67-96 wt.% Mg, 1.2-30 wt.% CaH₂, 9 wt.% Ca and 2 wt.% Zn constant were studied. The prepared powders were then pressed under a load of 26 MPa at room temperature. Sintering process of green compacts was conducted at 350 °C for 2 h continued to 520 °C for 1 h. The sintered green compacts were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis (EDS). The XRD results showed the sintering process affects the phase formation of Mg, Ca, Mg₂Ca, and MgCaZn. Mg₂Ca binary phase to be avoided because its leading to reduce mechanical properties of the final product.

Abstract: The purpose of this research is to study the manufacturing of biocompatible implant component by using rapid prototyping technology, in particular of 3D printing process. The biocompatible material consist of 80% cobalt-chromium-HAP were prepared by mechanically blended with 10% maltodextrin and 10% polyvinyl alcohol as binding mechanism for 3D printing process. Test specimens were fabricated using experimental 3D printing machine followed by sintering process. The characteristic of the composites were studied using various techniques including Scanning Electron Microscope (SEM and EDS), hardness test, flexural test, porosity and density measurement. The results show that the biocompatible cobalt implant composite can be fabricated successfully using 3D printing process. Further investigation can be carried out on the samples to study the toxicity, chemical reaction and cell reaction for implant application.

Abstract: Semi-solid processing of materials provides advantages of both forging and casting. Experiments with high-melting and biocompatible alloys aiming at a “near-net-shape” production technology recently have been conducted. Advanced trials showed, that processing of such materials by means of semi-solid forming deliver a huge potential for feasible workpiece shapes and drastically reduces machining time and subsequent surface treatment efforts. In contrast to semi-solid forming of aluminium alloys at relatively low temperature levels any processing of high-melting point alloys in the semi-solid state is much more challenging due to higher forming temperature. Commonly used tool materials provoke high wear rates due to wetting, bonding and melting processes which finally result in a very short tool life time. Thus, more apt materials and composites for forming tools and dies which can withstand corrosion, wear, tear and extreme changes in temperatures have to be found. The development of new design concepts for long-living close-to-production tools based on such new materials will be a future goal.