Search results for "YAP"

Enhancing Biocompatibility and Antibacterial Activity of Ti6Al4V by Entrapping Ag and Hydroxyapatite Inside Alginate Filled Pores of TiO 2 Layer Grow…

2022

A three-step electrochemical process is developed to grow a coating on Ti6Al4V alloy for biomedical applications aimed to enhance its bioactivity. The coating is composed by a porous titanium oxide filled with Ag, alginic acid, and hydroxyapatite to provide antibacterial properties and, at the same time, osteointegration capability. Anodized and treated with the electrochemical process samples are characterized by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction, and Raman Spectroscopy to have information about morphology and composition soon after the fabrication and after immersion in Hanks' solution. Bioactivity of the samples is also prov…

Biological characterization of Poly-L-lactic acid (PLLA)/Hydroxyapatite (HA)/Bioglass (BG) composite scaffolds made by Thermally Induced Phase Separa…

In the last few years, Tissue Engineering has focused on the favourable effects that composite scaffolds have on cell adhesion, growth and differentiation. In fact, composite scaffolds, usually composed of a synthetic polymer supplemented with naturally occurring components, display superior mechanical properties and bioconductivity than scaffolds consisting of a single component. Hydroxyapatite (HA) is the major inorganic component of bones. Bioglass (BG) is known to exert stimulatory effects on cells by ion release and hence, could be also advantageous for Bone Tissue Engineering. Poly-L-lactic acid (PLLA) is a versatile synthetic polymer combinable with HA and BG. The aim of this work wa…

Hydroxyapatite/Chitosan/Collagen coatings through galvanic coupling

In this work, the attention was focused on Hydroxyapatite/ Chitosan/Collagen composite as biocoatings for application in orthopaedic devices. Hydroxyapatite was selected for its osteoconductivity due to its chemical structure similar to bones. Collagen has the same function since 90-95% of bone matrix is constituted of collagen fibers. Furthermore, chitosan are largely used yet in medical field (e.g. antibacterial agent or drug deliver) and in this work were used to create a synergic interaction with hydroxyapatite and collagen to increase the strength and bioactivity of coating. Coatings were fabricated by galvanic deposition process that has different advantages an it does not require ext…

Deposition and characterization of Hydroxyapatite-Chitosan coatings on 304 SS for biomedical devices

2019

During the last years biomaterials have been largely investigated in order to perform and improve biomedical devices. As regards orthopedic field, the most common equipment used (such as implants, bone grafts or screws) are constituted by metallic materials (steel and titanium alloys), characterized by low/medium resistance to corrosion and low osteointegration ability. Furthermore, these factors could produce local inflammations of the tissues surrounding the implants, increasing kinetics of corrosion phenomena. Scientific community has focused the attention on biocoatings interposed between metal and aggressive environment in order to inhibit corrosion. Furthermore, these coatings are abl…

Galvanic Deposition of Calcium Phosphate/Bioglass Composite Coating on AISI 316L

2023

Calcium phosphate/Bioglass composite coatings on AISI 316L were investigated with regard to their potential role as a beneficial coating for orthopedic implants. These coatings were realized by the galvanic co-deposition of calcium phosphate compounds and Bioglass particles. A different amount of Bioglass 45S5 was used to study its effect on the performance of the composite coatings. The morphology and chemical composition of the coatings were investigated before and after their aging in simulated body fluid. The coatings uniformly covered the AISI 316L substrate and consisted of a brushite and hydroxyapatite mixture. Both phases were detected using X-ray diffraction and Raman spectroscopy.…

Stability analysis of type-2 fuzzy logic controllers

2009

The application of the direct Lyapunov method to the stability analysis of systems controlled by type-2 fuzzy logic controllers (FLC) is presented. The method is an extension of a method proposed for type-1 fuzzy systems. It is usually applied to systems described by state equations and controlled by fuzzy controllers using state variables as inputs but has been extended to controllers that have the error and the integral of error of the controlled variable as inputs. The proposed method allows to modify the controller rule base so that the controlled system is stable in the operating range defined by the manipulative variable constraints. The method is applied to the stability analysis of …

Comparison of adsorption equilibrium models and error functions for the study of sulfate removal by calcium hydroxyapatite microfibrillated cellulose…

2017

In the present study, the adsorption of sulfates of sodium sulfate (Na2SO4) and sodium lauryl sulfate (SLS) by calcium hydroxyapatite-modified microfibrillated cellulose was studied in the aqueous solution. The adsorbent was characterized using elemental analysis, Fourier transform infrared, scanning electron microscope and elemental analysis in order to gain the information on its structure and physico-chemical properties. The adsorption studies were conducted in batch mode. The effects of solution pH, contact time, the initial concentration of sulfate and the effect of competing anions were studied on the performance of synthesized adsorbent for sulfate removal. Adsorption kinetics indica…

Different Type Clay Amendments for Lead Immobilization in Contaminated Soils

2014

Contamination with lead in soil is a crucial problem in industrial and military sites. Immobilization of lead by natural and modified clay as soil amendment can be an effective solution to this problem. Quaternary and Devonian clays were chosen for modification with NaCl, CaCl2, FeOOH and Ca10(PO4)6(OH)2 in different proportions of Ca/P equimolar ratio to test and compare immobilization efficiency of lead (II) on raw and modified clays by using a batch leaching test. The aim of the study is to compare different types of raw and modified clays as soil amendments by lead immobilization properties.

In vitro corrosion and biocompatibility of brushite/hydroxyapatite coatings obtained by galvanic deposition on 316LSS

2018

Corrosion behavior and cytotoxicity was reported for mixed brushite (BS)/hydroxyapatite (HA) coatings deposited on 316LSS substrate through a displacement reaction. Corrosion tests, carried out in a simulated body fluid, showed that in comparison with bare 316L, coating shifts Ecorrto anodic values and reduces icorreven if oscillations were observed, which were explained in terms of the chemical interactions at the solid/liquid interface. Cell biocompatibility of the coating was investigated through osteoblastic cell line MC3T3-E1, evidencing the absence of any cytotoxicity Taken together, the results show that galvanic deposition is a simple and cost-effective method for producing bioactiv…

Molecular mechanisms of sorafenib action in liver cancer cells.

2012

Sorafenib, a multikinase inhibitor, recently received FDA approval for the treatment of advanced hepatocellular carcinoma (HCC). However, as the clinical application of sorafenib evolves, there is increasing interest in defining the mechanisms underlying its anti-tumor activity. Considering that this specific inhibitor could target unexpected molecules depending on the biologic context, a precise understanding of its mechanism of action could be critical to maximize its treatment efficacy, while minimizing adverse effects. Two human HCC cell lines (HepG2 and Huh7), carrying different biological and genetic characteristics, were used in this study to examine the intracellular events leading …