Medical titanium alloy Ti-6Al-4V (TC4) is an ideal surgical implant material for human tissue repair and replacement. TC4 implantation will be in close contact with human soft tissue and has mechanical compatibility problems. In order to solve this problem, the hydrogel was formed on the surface of TC4 by utilizing the adhesion of dopamine, and the storage modulus of the formed hydrogel matched that of human soft tissue. In this paper, the surface of TC4 was first modified with dopamine (DA) and 2-bromoisobutyryl bromide (BIBB). 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA), oligo (ethylene oxide) methacrylate (OEGMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) are used as monomers, and methylenebisacrylamide (MBA) is used as cross-linking agent. Thermosensitive hydrogels were formed on the surface of modified TC4 by the ATRP technique. The successful synthesis of initiator and hydrogels on TC4 was demonstrated by Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS). The morphology of the hydrogel was observed by the scanning electron microscope (SEM), and the water absorption and temperature sensitivity were investigated by the swelling property. The thermal and mechanical properties of these gels were measured using thermal analysis system (TAS) and dynamic mechanical analyzer (DMA). The results show that the hydrogel on TC4 has good thermal stability and storage modulus that matches human soft tissue.

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Synthesis and Properties of Hydrogels on Medical Titanium Alloy Surface by Modified Dopamine Adhesion

This study aims to characterize a new Ti-25Ta-25Nb-5Sn alloy for biomedical application. Microstructure, phase formation, mechanical and corrosion properties, along with the cell culture study of the Ti-25Ta-25Nb alloy with Sn content 5 mass% are presented in this article. The experimental alloy was processed in an arc melting furnace, cold worked, and heat treated. For characterization, optical microscopy, X-ray diffraction, microhardness, and Young’s modulus measurements were employed. Corrosion behavior was also evaluated using open-circuit potential (OCP) and potentiodynamic polarization. In vitro studies with human ADSCs were performed to investigate cell viability, adhesion, proliferation, and differentiation. Comparison among the mechanical properties observed in other metal alloy systems, including CP Ti, Ti-25Ta-25Nb, and Ti-25Ta-25-Nb-3Sn showed an increase in microhardness and a decrease in the Young’s modulus when compared to CP Ti. The potentiodynamic polarization tests indicated that the corrosion resistance of the Ti-25Ta-25Nb-5Sn alloy was similar to CP Ti and the experiments in vitro demonstrated great interactions between the alloy surface and cells in terms of adhesion, proliferation, and differentiation. Therefore, this alloy presents potential for biomedical applications with properties required for good performance.

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Mechanical Properties, Corrosion Behavior, and In Vitro Cell Studies of the New Ti-25Ta-25Nb-5Sn Alloy

Ti6Al4V substrates were electrochemically deposited with nano-crystalline hydroxyapatite (HA) from aqueous electrolytes. Cathodic HA coatings were obtained when the electrolyte was stirred using ultrasonic vibration. Two current densities of 20 mA/cm2 and 50 mA/cm2 were employed. Polarization and electrochemical impedance spectroscopy (EIS) were the techniques used to estimate the corrosion of coatings in simulated body fluid (SBF). The results indicate good corrosion resistance for the coating obtained at 50 mA/cm2 from ultrasonic stirring of the electrolyte.

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Corrosion of Stirred Electrochemical Nano-Crystalline Hydroxyapatite (HA) Coatings on Ti6Al4V

Highlight Research

Autoclaving for 3x3 hours followed by alkaline hydrolysis (3x3AH) may lower nano-calcium particle size into 47.47 nm
3x3AH sample contain 30.73% calcium and 18.37% phosphorus
3x3AH sample created the best calcium solubility (26.14 %) in comparison to synthesized CaCO3 (14.34 %)
Grouper nano-calcium powder includes trace quantities of organic content, such as protein and fat, which enhance calcium's solubility.

 
Abstract
Fish bone nano-calcium production may solve two challenges, providing calcium for lactose-intolerant people and recycling bone waste. Fish bone autoclaving prior to extraction reduces fat, denatures collagen, and softens bones but only few researches have compared autoclaving duration with nano-calcium product quality, particle size, and its solubility in in vitro testing. This study studied the influence of autoclaving duration followed by alkaline hydrolysis on nano-calcium characteristics to enhance calcium solubility in in vitro gastrointestinal simulation experiments. The dried grouper (Epinephelus sp.) bone was divided into four groups: 0A (no autoclaving), 3A (3 h autoclaving), 2x3A (double cycle for 3 h autoclaving), and 3x3A (triple cycle for 3 h autoclaving). Each group was followed by alkaline hydrolysis, designated as 0AH, 3AH, 2x3AH, and 3x3AH. The results showed that autoclaving for 3x3 hours followed by alkaline hydrolysis resulted in lowest nano-calcium particle size of 47.47 nm consisting of 30.73% calcium and 18.37% phosphorous. 3x3AH sample created the best calcium solubility (26.14%) in comparison to synthesized CaCO3 (14.34%). In contrast to synthetic CaCO3, grouper nano-calcium powder includes trace quantities of organic contents, such as protein and fat, which enhance calcium solubility. In vivo research should be established to study the bioavailability and influence of grouper nano-calcium powder on bone density.

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Autoclaving and Alkaline Hydrolysis Effects on the Particle Size and Solubility of Grouper (Epinephelus sp.) Nano-calcium Powder in In Vitro Gastrointestinal Tract Simulation

As the population ages, so does the demand for bone loss treatments. The main components of these medicines must be able to endure longer and perform more effectively. Bone cement made of poly (methyl methacrylate) (PMMA), which is often used in damaged bone replacement surgery, is a vital biological material. As a result, the impact of additional nanoparticles such as zirconium dioxide (Zr02) and magnesium oxide (MgO) on polymer binary blends (Acrylic bone cement: 15% PMMA) for a bone scaffold was studied in this research. ZrO2 and MgO nanoparticles were introduced in various weights present to the polymer mix matrix 0, 0.5, 1, 1.5, 2). Hand lay-up molding using two different types of PMMA material was utilized to create the polymer. The reinforcement materials were mixed individually with a binary polymer blend material according to the reinforcement material selection ratio, and then heat-treated at 55°C for 3 hours to complete polymerization and remove any residual stress. Mechanical characteristics such as tensile strength and Young's modulus were evaluated for all of the prepared samples. The chemical bonding of nanoparticles and synthetic binary polymeric mix composites was evaluated using Fourier transform infrared spectroscopy (FTIR). The tensile strength and Young's modulus of a binary polymeric blend reinforced with (1.5wt% ZrO2, and 1wt% MgO) both dramatically increased. A scanning electron microscope (SEM) was used to examine the surface morphology of the fracture surface of tensile specimens. SEM images demonstrated that nanoparticles (ZrO2 and MgO) were distributed uniformly throughout the polymeric mix matrix.

Polymer Blends and Nanocomposite Materials Based on Polymethyl Methacrylate (PMMA) for Bone Regeneration and Repair

The main methods for preventing fires are physical, chemical, or a combination of the two. One of the main thermophysical characteristics that connect the chemical structure is thermal diffusivity. The relationship between heat transport as well as heat resistance has been thoroughly established in the literature. Heat transmission can also be connected to various fire-retardant characteristics, like maximal heat release or time to ignite, which rank among the most crucial factors in defining the potential fire danger of a specific material. The thermal stability, as well as fire-retardant qualities of polymers, are enhanced by metal oxides. In the present investigation, simulations of molecular dynamics constructed using the single atom approach was used to examine the consequence of Al2O3nanoparticles on thermal transfer of isotactic polymethyl methacrylate. Capacity, density, and thermal transfer were studied in the 300-700 K range to examine the heat transfer rate of poly (methyl methacrylate) besides poly (methyl methacrylate)/Al2O3nanocomposite. It is possible to calculate heat capacity using fluctuating characteristics. Conductivity was calculated through a non-equilibrium modeling simulation using Fourier's law. The thermal diffusivity of the poly (methyl methacrylate) with the thermal conductivity is increased by over ten times by the alumina nanoparticles, which also enhances the Tg by around 10 K The results show that the Al2O3nanoparticles increase a transition temperature of glass; conductivity, in addition diffusivity of the poly (methyl methacrylate) while decreasing the heat capacity.

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Analyzing the Heat Transfer Rate of Nanostructures of Poly (Methyl Methacrylate) / Al2O3 Utilizing Molecular Dynamics Simulations

A CO2 laser produces infrared photons that are largely absorbed by the skin and cause morphological alterations. Twenty-four (Wistar) rats weighing 290-380 g and ranging in age from 8 months to a year were chosen at random and divided into sixteen rats for histological examination and eight rats for tensile testing to determine the extent of injury caused by photothermal damage induced by multiple doses of a CO2 laser. Anesthesia was achieved with intramuscular doses of 10 mg/kg ketamine and 60 mg/kg Xylazine. Two equal 0.5 cm surgical incisions of rat dorsal skin were performed on the left and right sides. One was utilized as a control while the other was subjected to a 10600 nm CO2 laser at various power levels (12.5, 14.1, 15.6, and 17.2) W/cm2. According to the histological analysis, the non-irradiated skin appeared to be flawless, and normal skin layers were observed. The amount of radiation in the irradiated skin samples was closely related to tissue damage. Higher dosages of irradiation resulted in the most severe cellular mutilation. Tissue injury manifested as epidermal obliteration, coagulation, homogeneous hyalinization, and hair loss. The effects of CO2 laser interaction with the skin were explored in-depth in this study. Exposure to the CO2 laser resulted in severe burns and coagulation.
 

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The Effects of Multiple Power Densities of Carbon Dioxide Laser on Photothermal Damage in Rat Skin Tissue

The{Poly4-Nicotinamido-4-Oxo-2-Butenoic Acid's}, which serves as an anti-corrosion layer, was produced by electropolymerized the {4-Nicotinamido-4-Oxo-2-Butenoic Acid's} monomer onto 316-grade steel material. The produced polymer's structure and characteristics were evaluated using SEM, cyclic voltammetry, and other techniques. The corrosion resistance of stainless steel, both uncoated and coated in a corrosive medium of 0.2M HCl solution was examined using an electrochemical polarisation technique at temperatures ranging from (293-323) K. Nanomaterials such as nano zinc oxide and graphene were introduced to monomer solutions at various concentrations to increase the corrosion resistance of stainless-steel surfaces. According to the findings, adding nano components to a polymeric coating increased its protective effectiveness. Thermodynamic and kinetic activation properties were also investigated. The percentage of protection efficiencies and polarisation resistance values of the covering polymer decreased as the temperature rose. As the temperature climbed, the corrosion current density increased, although the corrosion potential decreased. In SEM and AFM experiments, the development of a protective coating on the surface of 316-grade stainless steel was demonstrated to protect it.

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Zeina J. Tammemi

Papers

Polymer Blends and Nanocomposite Materials Based on Polymethyl Methacrylate (PMMA) for Bone Regeneration and Repair

Analyzing the Heat Transfer Rate of Nanostructures of Poly (Methyl Methacrylate) / Al2O3 Utilizing Molecular Dynamics Simulations

The Effects of Multiple Power Densities of Carbon Dioxide Laser on Photothermal Damage in Rat Skin Tissue

Analysis of the {4-Nicotinamido-4-Oxo-2-Butenoic Acid's} Electrochemical Polymerization as an Anti-Corrosion Layer on Stainless-Steel Alloys