Human bone is composed of nano-sized organic and mineral phases. Hydroxyapatite (HAP) is the main mineral component of bone (70% of bone composition) and it is effectively used in all biomedical ...applications. This component has been extensively studied as a material for bone implantation, and its excellent bioactivity and osteoconductivity has been clearly established. A key component in tissue engineering for bone regeneration is the scaffold that acts as a template for cell interactions and the formation of bone-extracellular matrix that provides mechanical support to the newly formed tissue. In the present investigation, hydroxyapatite has been prepared by wet chemical method and the polymers such as PVA, PVP are to be used to prepare the scaffolds. The genipin used as cross linker to control the pore size which can enhance the cell proliferation for tissue engineering. The formations of synthetic scaffolds are characterized by FT-IR, XRD, and SEM-EDAX analysis. Invitro study of the scaffolds are analysed by SBF immersion, Hemolytic assay, biodegradation study, MTT Assay. From the study we inferred that the polymer based cross linked scaffolds demonstrated stimulatory effects to control the pore and also showing good hemolysis, control biodegradation and enhancing the cell proliferation for bone tissue engineering application.
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/Fe
3
O
4
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 aureu
s 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/Fe
3
O
4
materials the adhesion and proliferation of cells. The heating capacity of the Ce-HAP/Fe
3
O
4
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.
Dual-doped hydroxyapatite (Ce4+/Si4+ doped HAP) coating with admirable bacterial resistance and enriched bioactivity was fabricated via spin-coating technique. In this study, Ce/Si co-doped ...hydroxyapatite was coated on Ti-6Al-4 V substrates as a triple layer with extreme centrifugal force (2000 RPM, 3000 RPM and 4000 RPM) to improve the biological performance of the coating in terms of enhanced bone apposition. Further, the coated substrate was characterized by XRD, FTIR and SEM-EDS techniques. The contact angle of the coating was measured through the sessile drop method and in vitro biomineralization was carried out in SBF solution to predict the apatite formation on the surface of the coated implant. Pathogen restriction behaviour of the coating was studied using gram-negative and gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa respectively. Among these, gram-negative bacteria, Escherichia coli revealed greater inhibition than other bacteria. In vitro cell viability assay using MG-63 osteoblast cell was performed for the optimised coating acquired at 4000 RPM and the result showed excellent biocompatibility towards the cell line. Corrosion resistance behaviour of the coating using Polarization and EIS study exhibited excellent corrosion resistance. Therefore, based on the in vitro studies, the designed multifunctional coating can act as a potential biomaterial in the field of biomedical engineering.
Graphical abstract for the sol-gel synthesis of cerium and silicon co-doped HAP and its various characterisation techniques. Display omitted
•Dual-doped (Ce/Si) hydroxyapatite coatings were fabricated on Ti-6Al-4 V by spin coating technique.•Highly microporous structure attained to improve the bone-bonding ability and biocompatibility.•Ce/Si coatings expanded the mechanical interlocking between the living bone and coated implant.•The Potentiodynamic polarization investigations proved to improve the corrosion resistance in SBF.
Nanosized hydroxyapatite (HAP) particles were prepared by sol–gel method from the water-based solution of calcium and phosphorus precursor. In this study, two calcium precursors such as calcium ...nitrate tetrahydrate and calcium acetate were chosen as calcium precursors. The influence of aging period, pH, viscosity and sintering temperature on crystallinity and morphology of the HAP particles were investigated for the two calcium precursors with triethyl phosphate precursor. The morphology of nano-HAP towards phosphorous precursor was dependent on the type of calcium precursor used. The HAP prepared from calcium nitrate and triethyl phosphate was spherically shaped whereas the one from calcium acetate was found to be fibrous in structure. Both HAPs were stable up to 1200
°C and their crystallinity increased with respect to the sintering temperature. The obtained sample was characterized through X-ray diffraction (XRD), P
31 nuclear magnetic resonance (NMR), scanning electronic microscopy (SEM) and TEM analysis. The sol derived from the optimized aging period for the two different calcium precursors was coated on 316L stainless-steel (SS) implant and its corrosion resistivity during long-term implantation was studied by cyclic polarization in Ringer's solution. Both HAPs have their own desirable qualities and were found to be corrosion resistive.
Zirconia ceramics are extensively used in high load bearing applications because of their high mechanical strength, fracture toughness, and high chemical resistance. It is used in many industrial ...applications such as sensors, batteries, corrosion resistance, and thermal barrier coatings. Zirconia is a bio-inert ceramic with excellent biocompatible material with tribological properties used for clinical applications. In this present investigation, zirconia ceramic has been synthesized in pure form through co-precipitation process. Calcination of ZrO.sub.2 was done at different temperatures ranging from 700-1000degreesC. The temperature's role was crucial in the phase formation of the pure ZrO.sub.2 and other variables, including reaction mixture and pH. The powder obtained was further characterized by FT-IR, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM-EDS). XRD reveals the phase transformation from the raw powder to monoclinic (m) and tetragonal (t) zirconia nanoparticles. Microhardness and fracture toughness were performed using the Vickers Micro-indentation test. In vitro cytotoxicity study using MG-63 Cell lines showed reliable results. The outcome of these studies overlays the mode of zirconia for biomedical applications.
Corrosion inhibition behavior of orange peel waste extracts in 1 M hydrochloric acid medium on mild steel surface was studied using weight loss studies, electrochemical impedance spectroscopy (EIS), ...potentiodynamic polarization and surface phenomena using scanning electron microscopy (SEM) analysis. Better inhibition efficiency for orange extracts was achieved by weight loss measurements. The maximum inhibition efficiency of 99.19% was achieved for 0.25% of waste extract at room temperature. EIS analysis revealed that increase in concentration of orange peel extract (OPE) increases the charge transfer resistance with the continuous decrease in capacitance which confirms the development of dense protective layer on the metal surface at the electrolyte interface. Both the electrochemical investigation such as potentiodynamic polarization and impedance analysis confirmed the improved inhibitory efficiency of OPE by following Langmuir isotherm model. SEM analysis confirms that the corrosion inhibition of OPEs was proceeded by forming an organic protective layer over the mild steel surface by means of the adsorption process by physical contact. These results confirm that the ethanolic extract of orange waste can be used as a potential corrosion inhibitor in industrial applications.
Introduction: There are very few studies from Western countries and almost none from India, that have tried to understand the factors influencing students’ motivation to volunteer for community ...service and much less on medical student’s motivation to volunteer for community service. Aim: To identify the factors that influence motivation of medical students to volunteer for community service. Materials and Methods: This was a descriptive study was done over a period of two weeks in November 2017. The study participants were medical students of a private medical college from Southern India. Semi-structured interviews were conducted using an interview guide based on a standardised motivation to volunteer inventory. Data was collected till data saturation was reached, which was 20 students. The interviews were conducted in privacy. Verbatim notes were taken and the interview was also recorded after taking consent from the participants. The data was transcribed and triangulation done. The data was analysed using the thematic analysis approach. Results: The main motives were enhancement and career motives. Value was not the main motive. Two other motives emerged, that were curiosity and relief from boredom. Conclusion: The study shows that the main motives behind volunteerism were enhancement and career. This was the first such study from India to the best of our knowledge which has enquired into the motives behind volunteerism in medical students.
•ZrO2/TiO2, SiO2/TiO2, and SiO2/ZrO2 composite coatings were deposited on Ti–6Al–4V by cost-effective EPD.•ZrO2/TiO2 composite coatings have shown higher order of corrosion resistance behavior than ...other composites.•Well adherent and strong coating estimated by traction force analysis indicates the pronounced effect of ZrO2/TiO2 composite.
Synthesized composite powders (ZrO2/TiO2, SiO2/TiO2, and SiO2/ZrO2) were successfully deposited on Ti–6Al–4V by electrophoretic deposition method (EPD) to improve its electrochemical characteristics for better biomedical applications. In the present investigation, the three composite powders were prepared by sol–gel synthesis and its phase purity was analyzed by Powder X-ray diffraction (XRD) method. Further, the performance of the deposited coatings was assessed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX), scratch resistance test. The electrochemical properties of the composite coatings were analyzed by Potentiodynamic (Tafel) polarization and electrochemical impedance spectroscopy (EIS) studies. From the results, we observed that the corrosion resistance behavior of the different composite coated metallic substrate exhibited divergent corrosion resistance nature than blank Ti–6Al–4V. Of all these coatings on Ti–6Al–4V, the composite made up of, ZrO2/TiO2 has pronounced corrosion resistance behavior in Ringer’s solution when compared to others. This behavior is due to the presence of strong adherent coating owing to the existence of uniform deposition on Ti–6Al–4V.
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