Preparation and characterization of sol-gel hydroxyapatite and its electrochemical evaluation for biomedical applications

In situ fabrication of cerium-incorporated hydroxyapatite/magnetite nanocomposite coatings with bone regeneration and osteosarcoma potential

With the ultimate goal of providing a novel platform able to inhibit bacterial adhesion, biofilm formation, and anticancer properties, cerium-doped hydroxyapatite films enhanced with magnetite were developed via spin-coating. The unique aspect of the current study is the potential for creating cerium-doped hydroxyapatite/Fe3O4 coatings on a titanium support to enhance the functionality of bone implants. To assure an increase in the bioactivity of the titanium surface, alkali pretreatment was done before deposition of the apatite layer. Scanning electron microscopy (SEM) in conjunction with energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) analysis, and Fourier transform-infrared (FTIR) spectroscopy were used to evaluate coatings. Coatings demonstrated good efficacy against Staphylococcus aureus and Escherichia coli, with the latter showing the highest efficacy. In vitro bioactivity in simulated body fluid solution showed this material to be proficient for bone-like apatite formation on the implant surface. Electrochemical impedance spectroscopy was undertaken on intact coatings to examine the barrier properties of composites. We found that spin-coating at 4000 rpm could greatly increase the total resistance. After seeding with osteoblastic populations, Ce-HAP/Fe3O4 materials the adhesion and proliferation of cells. The heating capacity of the Ce-HAP/Fe3O4 film was optimal at 45 °C at 15 s at a frequency of 318 kHz. Osseointegration depends on many more parameters than hydroxyapatite production, so these coatings have significant potential for use in bone healing and bone-cancer therapy.

Hydroxyapatite-chitosan biocomposites synthesized in the simulated body fluid and their drug loading studies

Hydroxyapatite (HAp) is a bioceramic applied in the biomedical areas, such as matrices for drug release control. Chitosan (CTS), a natural polymer, is another material has been widely investigated for its potential use in the drug delivery systems. In this study, the composites of HAp-CTS are produced in order to investigate their drug loading and release studies. First of all, HAp-CTS composites are produced in the presence of simulated body fluid (SBF). Analysis confirmed the structure of HAp-CTS composites. Secondly, composites are encapsulated with 5-Fluorouracil (5-FU). The weight ratio of CTS is varied to realize its effect on drug loading of 5-Fluorouracil, a cancer drug, for the ratios of 1:1, 1:2 and 1:4 of HAp-CTS. The weight ratio giving the greatest drug load efficiency is selected for the last step of the study. Crosslinking agent, glutaraldehyde, are changed from 0 to 5% on the selected sample, then, drug loading is examined again in various environment owing different pH. Furthermore, drug release studies are conducted. To understand the structure and morphology of the samples, XRD, FTIR, SEM and Uv-Spectrum are applied. It is observed that weight ratio of polymer and crosslinking agent can be manipulated to adjust drug loading. Release kinetics are shown the Fickian diffusion. This new produced material can be applicable for drug delivery.

Synthesis of Spherical Nano-Hydroxyapatite by Hydrothermal Method with L-Lysine Template

In this paper, spherical nanohydroxyapatite was synthesized by hydrothermal method. During the synthesizing process, different amount of L-lysine template was added with the hydrothermal temperature 185 °C and the time 25 h. The products were characterized by using FTIR, XRD and TEM. Results showed that the rod-like nanohydroxyapatite changed its granule morphology into spherical obviously after adding L-lysine. Spherical nanohydroxyapatite was synthesized with mean particle size about 25 nm.

Comparison study of biomimetic strontium-doped calcium phosphate coatings by electrochemical deposition and air plasma spray: morphology, composition and bioactive performance

In this study, strontium-doped calcium phosphate coatings were deposited by electrochemical deposition and plasma spray under different process parameters to achieve various coating morphologies. The coating composition was investigated by energy dispersive X-ray spectroscopy and X-ray diffraction. The surface morphologies of the coatings were studied through scanning electron microscopy while the cytocompatibility and bioactivity of the strontium-doped calcium phosphate coatings were evaluated using bone cell culture using MC3T3-E1 osteoblast-like cells. The addition of strontium leads to enhanced proliferation suggesting the possible benefits of strontium incorporation in calcium phosphate coatings. The morphology and composition of deposited coatings showed a strong influence on the growth of cells.

Comparative assessment of structural and biological properties of biomimetically coated hydroxyapatite on alumina (alpha-Al2O3) and titanium (Ti-6Al-4V) alloy substrates

Previous reports have shown the use of hydroxyapatite (HAp) and related calcium phosphate coatings on metal and nonmetal substrates for preparing tissue-engineering scaffolds, especially for osteogenic differentiation. These studies have revealed that the structural properties of coated substrates are dependent significantly on the method and conditions used for coating and also whether the substrates had been modified prior to the coating. In this article, we have done a comparative evaluation of the structural features of the HAp coatings, prepared by using simulated body fluid (SBF) at 25 degrees C for various time periods, on a nonporous metal substrate titanium-aluminium-vanadium (Ti-6Al-4V) alloy and a bioinert ceramic substrate alpha-alumina (alpha-Al(2)O(3)), with and without their prior treatment with the globular protein bovine serum albumin (BSA). Our analysis of these substrates by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectrometry showed significant and consistent differences in the quantitative and qualitative properties of the coatings. Interestingly, the bioactivity of these substrates in terms of supporting in vitro cell adhesion and spreading, and in vivo effects of implanted substrates, showed a predictable pattern, thus indicating that some coated substrates prepared under our conditions could be more suitable for biological/biomedical applications.