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Metallic elements are one of the key components of human physiology, which are required for basic cellular and extracellular functions. Herein, we provide insight into the bioactive metallic dopants silver (Ag), zinc (Zn), copper (Cu), magnesium (Mg) and ceria (Ce), which provide resistance against human pathogenic bacteria, and summarise the pathways for their generated effects crucial for osteogenic activity in an antibacterial environment and bone regeneration. Although most of these elements interact with genetic material, resulting in denaturation to produce apoptosis of pathogenic cells, some create adverse effects in the cellular matrix, which interfere with normal cellular metabolism and inhibit cellular activity, reducing the further growth and formation of bacterial colonies. Furthermore, although remarkable antibacterial activity has been recorded, bacterial cells have developed pathways and transporter proteins that remove the excess of these antibacterial elements from the cellular matrix. Thus, a discussion of these reported pathways as limitations is presented to find more novel modes of administration of these elements since they show good biocompatibility and are non-cytotoxic at certain release concentrations. As a cofactor of several enzymes, it is worth noting that some of these elements not only help in the metabolism of bone, but also activate the genetic pathways that regulate the formation of and maintain the factors that support new bone. The choice of incorporating these materials in ionic or nanoparticle form depends on the target substrate since they exhibit different mechanisms of action and even produce selective effects depending on their physical properties.

Microalgae compose a highly diverse group of unicellular microorganisms that includes both prokaryotic and eukaryotic organisms. They are aquatic and perform photosynthesis, contributing considerably to the total biomass on the earth. The major biochemical constituents of microalgae are lipids, proteins and carbohydrates whereas other constituents include chlorophylls, carotenoids, fatty acids, proteins, phenolics, alkaloids, terpenoids and many more. Microalgae have been extensively studied for a number of bioactive compounds which have pharmaceutical and industrial uses. They are not only utilized to obtain commercially valuable compounds, but also offer immense potential for waste water treatment. This chapter showcases a comprehensive account of exploration of the microalgal biomass for obtaining high value compounds. Various extraction processes that are in use for yielding the microalgal secondary compounds are discussed. The chapter also elaborates upon the screening assays of bioactive compounds for antioxidant, antimicrobial, anti-inflammatory, immune-modulatory and some other activities. Further, the pharmaceutical and industrial uses of the bioactive compounds obtained from microalgae are discussed to uncover its potential for commercial applications.

Most high load-bearing implants are metallic alloys which contain toxic chemical components that might be released due to the corrosive environment of body fluids and load-bearing activity. Surface modification techniques do not guarantee biocompatibility. Hence, the bioactive surface of implants can be modified by coating the surface with a suitable material that addresses the needs of the patient. The choice and application process of the coatings should be determined based on the workability of the material and its physiochemical properties, such as the procedures involved and performance in avoiding removal of any desirable material properties that are helpful in the tissue regeneration process. Tailor-made coating materials prove very promising, as they might improve permanent implantations, make them more affordable and reduce the need for surgical revisions. The scope of the featured properties, such as addition of accelerated tissue regeneration, antibacterial properties and controlled release and removal of debris from the biological system to the metal implants makes coatings an ideal choice for surface modification of implants. This report reviews several options available for forming a biologically active layer over metallic surfaces that will interact with and produce desirable effects on host tissues.

The present study elaborates the bioactive and optical features of Yb3+/Tb3+ co-doped bio-active glass. Three different combinations with assorted elemental concentrations were investigated. The amorphous nature of bioglass devoid of crystalline phases until 700 °C has been confirmed through XRD analysis. The results from Raman and FT-IR accomplished the presence of Si–O–Si broad vibrational modes typical of amorphous glass and further the characteristic PO4 vibrations were also confirmed. The up-conversion luminescence studies revealed the typical Tb3+ emission excited at 976 nm. The mechanism that involved in the up-conversion and energy transfer emission phenomena were discussed. Morphological features of SBF immersed specimen affirm the formation of apatite layer by the spherical spongy agglomerates observed over the surface.

Direct metal laser sintering (DMLS) is an additive manufacturing technique that enables the production of customized and complex shaped stainless steel products. Application of DMLS parts to critical sectors requires enhanced surface properties. Although extensive research has been undertaken by many investigators on γ-alumina coating on conventionally processed SS 316L, there has been no significant exploration of the properties of SS 316 L processed through DMLS process with and without coating. In this study, an attempt has been made to coat γ-alumina ceramics over 316L SS substrate and report its effects. γ-alumina synthesised using sol-gel technique was examined through Fourier-Transform Infrared Spectroscopy and X- Ray Diffractometer. The coating were 28–36.77 μm thick and had amorphous structures. Characterization on coated substrate displayed a 33.87% increases in hardness and 81.91% increase in roughness. The water contact angle of the coated substrate exceeded bare substrate measurements by over 340. Icorr value of 0.0967 for coated substrate confirmed the anti-corrosive behaviour, which was found to be very much an essential requirements for this study. Compared with conventional processed SS 316L, the performance of DMLS SS 316L, the performance of DMLS SS 316L bare substrate and coated substrate are mainly governed by properties such as porosity, laser scanning effect, in build residual stress and surface finish. The development of uniform and adherent coating of γ-alumina acts as a mechanical barrier for enhancement of the surface properties which will enlighten the research and applications in the fields of biomedical, aerospace and automobile industries.

Licoisoflavone B, licochalcone A, and liquirtigenin are important flavonoids found in the medicinal plant Glycyrrhiza glabra and are known for their preventive and therapeutic potential against cancer. Extraction of these flavonoids in commercially viable quantities is a challenging task. Therefore, an attempt has been made to elicit the production of these flavonoids in tissue cultures of G. glabra. We investigated the effect of the biotic elicitor yeast extract (YE) on the production of three flavonoids in G. glabra callus cultures grown in a previously standardized nutrient medium consisting of Murashige and Skoog’s medium components supplemented with naphthalene acetic acid and benzyl amino purine. The YE elicitor was tested in the concentration range of 25–175 mg/l. At each elicitor concentration, a time-course analysis was also performed to determine the effect of the duration of YE treatment on flavonoid production. The effect of YE on the key enzyme of the phenylpropanoid pathway, phenylalanine ammonia lyase (PAL), antioxidant enzymes, polyphenoloxidase (PPO), and peroxidase (POD) was also observed. The results revealed that 75 mg/l concentration of YE was most suitable for elicitation of biosynthesis of flavonoids in G. glabra cultures and more than a 2-fold increase in the production of all the three flavonoids was obtained. The activities of the enzymes, PAL, PPO, and POD, also increased significantly, suggesting that the stress response was elicited by YE. These results provide evidence of activation of phenylpropanoid metabolism and regulation of its key enzymes by YE, eventually leading to enhanced production of anti-cancerous flavonoids licoisoflavone B, licochalcone A, and liquirtigenin.

Graphene oxide incorporated hydroxyapatite hybrid films were coated on 316L stainless steel substrate with the aid of electrochemical studies at the voltage of −1.5 V for 30 min using three electrode arrangements. Purity and crystallinity of the formed HAP/GO composite coatings were examined using X-ray diffraction and Fourier transform infrared spectroscopic studies. Phase of the hydroxyapatite was not affected with incorporation of graphene oxide into its matrix. Well-ordered and compact coating morphology was observed for the electrochemically deposited HAP/GO on 316L substrate using the scanning electron microscopy. High-resolution transmission electron microscopic studies reveal the tight bonding and growth of HAP particles on to the sidewalls of GO sheets. Electrochemical studies for the HAP/GO composite coating against the physiological solution showed improved corrosion efficiency. Addition of GO into HAP enhances the apatite precipitation and bone-bonding ability. These results concluded that the electrochemical deposition of bioceramic coatings on implant may be treated as an effective method for orthopedic repair and replacements.

Structural features of apatites make them one of the most promising candidates for bone tissue regenerative applications. The unique structure and availability of mobile Metal ion as well as other components help interaction with biological fluids and can promote as well as stimulate bone regeneration with correct components. The present study focusses on Strontium phosphosilicate, an apatite analogue to Calcium phosphate-based HAP only loaded with better composition replacing Calcium with stimulatory Strontium and co-existent Silicate alongside phosphate both known to stimulate osteogenesis. Bulk particles were synthesized as powders with Acidic medium as well as the Basic medium of reaction mixture via Sol-Gel and Co-precipitation techniques respectively and phase formation was studied with respect to temperature further detailed by TGA-DSC studies. Secondary phases were also indexed based on which Acidic medium samples sintered at 800°C were comparatively better from the Basic medium on account of the presence of silicate phase forming agglomerated Strontium phosphosilicate. Hemolysis assay and MG-63 based cytotoxicity assay were carried out to study biocompatibility and antibacterial properties were also elucidated in Gram-positive and Gram-negative bacteria. Apatite seeding and bone mineralization studies were carried out with Simulated body fluid and characterized structurally and morphologically.

Synthesis of Pure phase and a series of Zinc substituted Strontium phosphosilicate was attempted in the present study and assessed structurally and biologically. The Sol-Gel technique ensured proper reactivity and apatite formation upon sintering. The acidic medium was more applicable for synthesis on account of the isoelectric point of silica and formation of secondary Sr2SiO4 phase, important and applicable in bioactivity apart from Sr2P2O7 as another secondary phase. Sintering formed agglomerated stable crystalline phases evident from diffraction further confirmed by infrared spectroscopy. The morphology showed minimal differences from the parent material increasing agglomeration upon the increment of dopant. Biological evaluations showed the successful formation of amorphous Calcium phosphate with two days of SBF immersion and proliferation of MG-63 Cells upon Zinc incorporation. The antibacterial properties were enhanced upon the incorporation of Zinc while Strontium phosphosilicate in the pure phase failed to produce favourable antibacterial activity.

In the present investigation, the natural cellulose was extracted from Luffa cylindrica vegetable sponge by chemical modification. Both chemically modified and unmodified Luffa was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy. The chemically modified cellulose was used for the preparation of a nanofibrous scaffold using the electrospinning method. In order to achieve the uniform and bead free fibers with desired fiber diameter the parameters such as applied voltage, tip to collector distance, solution concentration were optimized. Different ratio of hydroxyapatite (HAP): polylactic acid (PLA) such as 40:60, 50:50, 60:40, and 70:30 have been selected for the current evaluation and was compared with HAP-treated cellulose (TC)-PLA. With the increase in the concentration of HAP in the polymeric network, the diameter of the fiber was found to be thin with the high electric field. The functional group, phase formation and dielectric and mechanical properties of the developed nanofiber have been characterized by FTIR, XRD, mechanical property measurements, and SEM. From the results, we observed that the polymer composite developed with the ratio of 70:30 produces a bead free product with enhanced mechanical and bioactivity property by the formation of hydroxy carbonated apatite layer on the surface. All the nanofibrous scaffold fabricated with and without modification have shown good Cyto compatibility on MG-63 Osteoblast cell lines at 48 hr. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 610-620, 2019.

Coatings using functionalized multi-walled carbon nanotubes (f-MWCNTs)/hydroxyapatite (HAP) on 316 L Stainless Steel by electrodeposition at the parameter of “-1.5 V” for 30 min. with three electrode set-up configuration and optimization of various concentrations of f-MWCNTs from 1 to 5% were done to improve the coating characteristics for future biomedical applications. The obtained coatings were characterized by Fourier Transformed-Infra Red spectroscopy (FT-IR) and X-ray diffractometer (XRD) to reveal the phase formation in the composites. With various additions of f-MWCNTs, the HAP phase was found to be retained. The growth of HAP on f-MWCNTs was analyzed by High-resolution Transmission Electron Microscope (HR-TEM) and the morphology of composite was found to be of the needle and flower-like particles. To understand the corrosion resistance effect of the developed HAP/f-MWCNTs composite in SBF, electrochemical investigations were carried out using Impedance and Tafel polarization analysis. From the results, it was observed that the coatings have enhanced corrosion resistance behavior and bioactivity. In addition, the Vickers Hardness study proved that the prepared HAP/fMWCNTs composite coating was found to have improved hardness value of (Hv) 390.2 ± 8.0. Thus, the electrodeposited composite coating on 316 L SS substrate can be effectively deployed for biomedical applications.

Multi-ion, co-substituted bioactive glass ceramics play a significant role in the stimulation of physical and biological properties for outstanding effects in biomedical application. The following work attempts to develop HAP as a parent material doped with a combination of cerium (Ce4+ @1.25 wt%) and silicon (Si4+ @1, 3 and 5 wt%) by refluxing based sol-gel technique. The anti-bacterial tests exhibit E. coli showing higher inhibition efficiency, in vitro hemolytic test exhibit good compatible nature of dual doped HAP with erythrocytes (

Cancellous bone region of the human native bone has the potential to bear significant mechanical loads. However, due to the following parameters such as low trabecular volume, more porosity, less thickness and more interconnectivity, cancellous bone is accessible to damage in accidents or when aging. This research led to the effective fabrication and engineering of cancellous region of the bone for its application in reconstruction or filling of bone voids after resection of large tumor mass. Scaffolds containing hydroxyapatite (HAp), polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) (5% polymer and HAp concentrations) at different HAp: polymer composite ratios (50:50, 70:30 and 80:20), were fabricated by freeze-drying method using only water as solvent and ribose as crosslinker for the scaffolds. The fabricated scaffolds were characterized for its mechanical (compressive) strength, chemical properties using FT-IR and XRD analyses, swelling and degradation studies, confirmation of mineralization process by immersion in simulated body fluid (SBF) for 7, 15 and 30 days, morphological analysis using scanning electron microscopy (SEM), and biocompatibility properties by performing MTT analysis. From the combined interpretation of the above mentioned tests, it was proven that 80:20 ratio of HAp to polymers was found to be the most suitable scaffold in terms of its optimal properties for its use as bone graft material for trabecular bone. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3267-3274, 2018.

Present paper deals with the development of hybrid nanocomposites which combination of Ag doped Hydroxyapatite (Ag:HAP)-Magnetite nanoparticles (Fe3O4NPs) and Chitosan. In this present investigation, we have employed sol–gel method to synthesize Ag:HAP using 5% of Ag concentrations. Furthermore, co-precipitation technique was employed to prepare Fe3O4 NPs and Ag doped HAP was mixed with it to develop hybrid composites. The planetary ball milling technique was used to incorporate the fabricated Ag:HAP-Fe3O4 composite material into the biopolymer chitosan at wt% of 50:25:25 respectively. In Vitro biocompatibility of Ag:HAP-Fe3O4 CS hybrid composites were evaluated by MTT assay using MG-63 cell lines for 24–48 h at 200–1000 μg/ml concentrations. Further, these hybrid composites were characterized by using ATR-FTIR, XRD and SEM techniques. The fabricated hybrid composite was found to be biologically compatible with MG-63 osteoblast cell lines to use in biomedical applications.

Quinazolines are unique class of compounds possessing exceptional antibacterial activity. Quinazolines class obtains its typical antibacterial activity due to its toxicity from‘hetero’ ring. Known to be the last line of protection against deadly TB bacteria, there are about twenty different quinazoline compounds used in pharma industry. One of the widely used precursors for synthesis of these drugs is 4-chloro-2-phenylquinazoline. In the present research, aminobenzamide and benzoyl chloride are reacted to obtain the cyclized intermediate, 2-phenylquinazoline, which on subsequent treatment with POCl3 forms in 4-cholro-2-phenyl quinazoline. This reaction takes about four days to finish with maximum yield of around 60%. A modification was done using silica coated magnetic nanoparticles (Fe3O4@SiO2) as solid support to further improve the yields attaining about 80% and reduction of reaction time to half. Based on the results obtained, it was concluded that the solid support facilitates the adsorption of acid chloride and also provides the catalytic surface for condensation reaction, due to the acidic nature of the silica gel. The POCl3 reaction uses the nanosilica surface to produce 4-chloro phenyl-2-qinazoline in 80% overall yield. The reason for improved yield could be increase in acidic surface area which could speed up the quinazoline cyclization. Though material chemistry supports are known to improve reaction yields, use of silica coated magnetic nanomaterials towards the quinazoline synthesis is reported for the first time. The characterization data of Fe3O4@SiO2 particles has shown that batch to batch consistency exists in synthesis and it can be used in the pharma industry.

1-Butanol is a well-known biofuel for blending with both gasoline and diesel. It is also reported to act as fuel additive and convert straight vegetable oil (SVO) into a diesel blend. The direct use of SVO and 1-butanol in diesel blends has important implications for the elimination of transesterification of triglycerides. The mechanism of SVO stabilization in diesel in the presence of 1-butanol remains unknown. The present work describes the physicochemical properties and mechanism of stability of biofuel blends with 1-butanol as a fuel additive. The presence of 1-butanol as an additive results in a clear homogeneous fuel composition. The mechanisms of triglyceride stability in fuel blends with 1-butanol were studied with fluorescence techniques using the charge transfer probes Nile Red and PRODAN. We found that the micro-environment of biodiesel blends with 1-butanol results in the stabilization of triglycerides by formation of reverse micelles. The charge transfer probes displayed fluorescence emission peaks representative of the region in which they are present. We observed that the four regions present in AOT reverse micelles are also present in this 1-butanol/SVO/diesel ternary mixture. The physicochemical analysis including friccohesity has suggested that the formed reverse micelle is stable. This study is the first attempt to understand the mechanism behind stabilization of SVO as diesel blend in presence of 1-butanol.

The current work focused on the development of hydroxyapatite (HAP) coating on laser textured metallic implants using electrophoretic deposition. HAP was synthesized by sol-gel technique and its phase purity and surface morphology were confirmed by FT-IR, XRD and SEM analysis. 316 L SS and Ti-6Al-4V metal implants were polished and the surface was modified using Nd-YAG laser operating at a pulse interval of 10 ns at various overlapping rate of 0%, 25% and 50%. The laser treated surface was characterized for its surface roughness using surface profilometry and surface morphology. The surface roughness of the metallic implants was increased by increase in the overlapping rate. The prepared HAP powder was electrophoretically deposited on bare and laser textured Ti-6Al-4V and 316 L stainless steel followed by vacuum sintering at 300 °C for 2 h. Scratch analysis results showed an improvement in adhesion strength for the HAP coatings on laser treated specimens than untreated metal. Corrosion efficiency of the coated samples was studied in SBF solution using EIS and potentiodynamic polarization studies. The result from the corrosion experiments proved increased corrosion resistance property of laser textured coated samples when compared to bare alloy due to higher adhesion of HAP coating on the metal surface.

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.

Bioceramic composite coatings were deposited on surgical grade 316L stainless steel substrate via in-situ electrolytic method by supplying the voltage of −1.5 V for 30 mins using three electrode arrangements. Formations of pure HAP/GO and HAP/f-MWCNTs composite films were developed and the structure of hydroxyapatite was retained even with incorporation of secondary materials into its matrix. Homogeneously dispersed dense coating was observed for the electrochemically derived HAP composite films on 316L SS. The attachment of GO and f-MWCNTs with hydroxyapatite particles were observed using high resolution transmission electron microscopic (HR-TEM). In-vitro corrosion studies of the fabricated bioceramic composite coatings showed better corrosion protection against the simulated body fluid. Apatite mineralization formed at faster rate for the prepared bioceramic composite films; further which it enhance their bone bonding ability. These results concluded that the electrochemical deposition of bioceramic coatings on implant may be treated as an effective method for orthopedic repair and replacements.

Synthesized composite powders (ZrO 2 /TiO 2 , SiO 2 /TiO 2 , and SiO 2 /ZrO 2 ) 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, ZrO 2 /TiO 2 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.

For the first time, in the present investigation, we have attempted the refluxing based sol-gel technique to synthesize cerium (Ce4+) doped hydroxyapatite (Ce-HAP) with different concentrations such as 0.5, 0.75, 1 and 1.25%. The Ce-HAP powders were evaluated for in vitro biological studies such as hemocompatibility, antibacterial activity and biocompatibility. These in vitro studies have demonstrated the prominent results such as compatible nature with human blood (

In this study, for the first time we have developed the composite coatings using sol-gel derived hydroxyapatite [HAP: (Ca) 10 (PO 4 ) 6 (OH) 2 ] and magnetite (Fe 3 O 4 ) on alkali treated Ti-6Al-4V alloy using various concentrations of Fe 3 O 4 nanoparticles such as 1, 3 and 5 wt% respectively. The fabricated composite coatings were characterized by XRD, SEM-EDAX and contact angle measurements. In vitro bioactivity study confirmed that the composite coated Ti-6Al-4V was highly bioactive and induces bone like apatite formation in the presence of Fe 3 O 4 NPs which involves the nucleus formation by developing Fe-OH groups on the surface of coatings. The corrosion resistance study proved that 1 wt% of Fe 3 O 4 with HAP composite coatings exhibit good anticorrosion behaviour than the 3, 5 wt% of composites due to lower Fe-OH groups and uniform with adherent layer which restricts the leaching of ions. Hence, this finding suggested that HAP/Fe 3 O 4 composites coated implants can be used for biomedical applications.

In this study, Inconel 625 superalloy was laser peened without protective coating to advance its electrochemical characteristics. For this purpose, a water penetrable laser source (wavelength ~ 532 nm) was operated at two power densities (6 and 9 GW cm− 2). Substantial residual compressive stresses developed at 9 GW cm− 2 whilst they were preponderantly tensile and anisotropic at 6 GW cm− 2. Hardness was unchanged after peening due to higher strength of the alloy. Peening increased the roughness but it is merely ≤ 1 μm. Corrosion rate exceedingly lowered about ~ 104 times at 6 GW cm− 2 compared to other conditions with a belittled current density fluctuation over certain applied potential range due to increased roughness. No pitting resulted in untreated and peened specimens. Threefold increase in charge transfer resistance noticed at 6 GW cm− 2 owing to enhanced defect density (measured with X-ray peak broadening).

Novel bioceramics have an intriguing role in implants and prostheses as surface protecting agents. These bioceramics have promising features such as biocompatible, bioactive, and corrosion-resistant natures. Among bioceramics, silica glass and its composite unravel its better desirability against corrosion and wear with interfacial bone bonding capability in physiological systems by nucleating calcium phosphates over the surface, thereby enhancing the osteoinductive property. In the current study, SiO2 and ZnO were obtained by processing silica and zinc oxide precursors at low temperature using low thermal volatilization sol-gel method. SiO2, ZnO, and its composite powders were characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), and scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX). Electrophoretic deposition (EPD) was used for coating on Ti-6Al-4V for improved coating characteristics. In addition, the effect of additives such as iodine and Polyvinylpyrrolidone (PVP) on coating limits was also optimized. Thin-film XRD, Optical Microscopy, SEM-EDAX, Raman spectroscopy, and the scratch resistance test characterized the coating. Tafel polarization and electrochemical impedance spectroscopy (EIS) studies were also carried out to assess corrosion resistance behaviour of the coating. The results showed that the composite coating has greater corrosion resistance than uncoated Ti-6Al-4V. Furthermore, improved mechanical property with better scratch resistance was also observed. These observations showed that composite coating could be useful in biomedical applications.

In this study, nanocomposite powder consisting of zirconia and titania (Zr–Ti) have been synthesised by sol–gel method, with the aim of protecting Ti‐6Al‐4V surface. A simple and low cost electrophoretic deposition (EPD) technique has been employed for coating the nanocomposite material on Ti‐6Al‐4V. The prepared nanocomposite powder was characterised for its functional groups, phase purity, surface topography by Fourier transform infrared spectroscopy, powder X‐ray diffraction and scanning electron microscopy. Further, the biocompatibility nature of the composite powder was studied by [3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide] colorimetric assay and fluorescence analysis with MG63 osteoblast cell lines. The electrochemical behaviour of composite coating was investigated by potentiodynamic polarization and electrochemical impedance method. The results obtained from the electrochemical techniques indicate more corrosion resistance behaviour with increase of R (ct) value with the corresponding decrease in R (dl) values. From the above findings, the composite coating acts as a barrier layer against corrosion by preventing the leaching of metal ions from a dense and defect free coating. A scratch test analyser was used to assess the integrity of the coating; the lower traction force value of composite coating with increase in load has confirmed the presence of thick adherent layer on the substrate.

The objective of this study is to evaluate the biocompatibility of composite powder consisting of silica and titania (SiO2–TiO2) for biomedical applications. The advancement of nanoscience and nanotechnology encourages researchers to actively participate in reinvention of existing materials with improved physical, chemical and biological properties. Hence, a composite/hybrid material has given birth of new materials with intriguing properties. In the present investigation, SiO2–TiO2 composite powder was synthesised by sol-gel method and the prepared nanocomposite was characterised for its phase purity, functional groups, surface topography by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy. Furthermore, to understand the adverse effects of composite, biocompatibility test was analysed by cell culture method using MG63 osteoblast cell lines as a basic screening method. From the results, it was observed that typical Si–O–Ti peaks in FT-IR confirms the formation of composite and the crystallinity of the composite powder was analysed by XRD analysis. Further in vitro biocompatibility and acridine orange results have indicated better biocompatibility at different concentrations on osteoblast cell lines. On the basis of these observations, we envision that the prepared silica–titania nanocomposite is an intriguing biomaterial for better biomedical applications.

The present study has been carried out to analyse the effect of the laser shock peening (LSP) with the absence of a coating on titanium alloy (Grade 5—Ti6Al4V) and to establish the best set of LSP parameters for enhanced surface characteristics. Ti6Al4V which has excellent mechanical properties is penned using Nd:YAG pulsed laser with 2D XY translation with water as confinement medium. Power density (3, 6, 9 GW/cm2), wavelength (532, 1064 nm) and overlap (60%, 70%) are the three process parameters considered to perform laser shock peening without coating (LSPwC). Surface roughness is increased with raise in wavelength and as well as other parameters too. Even though hardness is increased in both wavelengths, enhanced hardness is caused with 1064 nm wavelength. An adequate amount of compressive stress is induced with 3 GW/cm2 at 50 μm depth. The rate of corrosion is dropped in samples LSPwC with 532 nm compared with 1064 nm wavelength due to its low surface roughness and surface oxide layer which holds the fluctuation of current density with respect to potential. SEM observation showed pits on the surface of samples peened with a 1064 nm wavelength. And this surface pitting is correlated with the fall of charge transfer resistance in such samples.

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.

Electrospinning is one of the promising techniques to fabricate the nanofiber based scaffold for bone regeneration applications. In this study, firstly sol–gel method was employed to synthesize 5 % of Ag doped hydroxyapatite and also 10 wt% of polyvinyl alcohol solution was prepared for the electrospun process. For the first time, we have successfully fabricated the composite nanofibers in the combination of various concentration of Ag doped hydroxyapatite such as 1, 2, 3, and 5 wt% with polyvinyl alcohol solution. The developed Ag doped hydroxyapatite-polyvinyl alcohol composites were further characterized by Fourier transform infrared spectroscopy and powder-X-ray diffraction analysis to examine the characteristic functional groups and phase composition of Ag doped hydroxyapatite embedded into polyvinyl alcohol matrix. The uniform distribution of Ag doped hydroxyapatite in polyvinyl alcohol polymer with nanofiber diameter of 188–242 nm range was confirmed by high resolution transmission electron microscope and dynamic light scattering analysis, also the chemical/elemental composition was observed by scanning electron microscopy-energy dispersive spectroscopy analysis. The antibacterial activity was evaluated for the fabricated Ag doped hydroxyapatite polyvinyl alcohol composite nanofibers by using Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) pathogens and the results demonstrated that E. coli exhibits excellent zone of inhibition than S. aureus due to its lesser cell wall thickness. The hemocompatibility study proves that the developed composite nanofibers are blood compatible and showed the hemolytic ratio of less than 5 %. In addition to this, in vitro bioactivity assessment was carried out for 7 days by immersing in simulated body fluid solution to generate the dense apatite layer on their surfaces which was further examined by X-ray diffraction and scanning electron microscopy-energy dispersive spectroscopy analysis. Hence, these electrospun fabricated Ag doped hydroxyapatite-polyvinyl alcohol composite nanofibers will acts as a potential scaffold material for tissue engineering applications. Graphical abstract of electrospun fabrication of Ag@HAP-PVA composite nanofibers and its in vitro biological evaluations.

M Chellappa,1 U Anjaneyulu,1 Geetha Manivasagam,2 U Vijayalakshmi1 1School of Advanced Sciences, Materials Chemistry Division, 2Centre for Biomaterials Science andTechnology, School of Mechanical and Building Sciences, VIT University, Vellore, Tamil Nadu, India Abstract: The purpose of this study is to prepare and evaluate the effect of synthesized titanium dioxide (TiO2) nanoparticles for their biocompatibility on physiological body fluids and the effect of cell toxicity to produce osteointegration when used as implantable materials. For the past few decades, the number of researches done to understand the importance of the biocompatibility of bioceramics, metals, and polymers and their effect on clinical settings of biomedical devices has increased. Hence, the total concept of biocompatibility encourages researchers to actively engage in the investigation of the most compatible materials in living systems by analyzing them using suitable physical, chemical, and biological (bioassay) methods. The ceramic material nano TiO2 was prepared by sol-gel method and analyzed for its functional group and phase formation by Fourier transform infrared spectroscopy and powder X-ray diffraction. Furthermore, the particle size, shape, surface topography, and morphological behavior were analyzed by dynamic light scattering, zeta potential, scanning electron microscopy–energy dispersive X-ray analysis, and transmission electron microscopy analysis. In addition to this, the cytotoxicity and cytocompatibility were determined on MG63 cell lines with varying doses of concentrations such as 1µg/mL, 10µg/mL, 25µg/mL, 50µg/mL, and 100µg/mL with different time periods such as 24hours and 48hours. The results have not shown any toxicity, whereas, it improved the cell viability/proliferation at various concentrations. Hence, these findings indicate that the nano TiO2 material acts as a good implantable material when used in the biomedical field as a prime surface-modifying agent. Keywords: biomaterial, implant, biocompatible, MTT assay, osteointegration, MG63 cell lines

The purpose of this study is to synthesize and characterize nanosized titania (TiO2), zinc oxide (ZnO), and its composite coating on Ti–6Al–4V to enhance its corrosion protection behavior in Ringer's solution. Nanosized powders of TiO2 and ZnO was characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy - energy dispersive atomic spectroscopy (SEM-EDAX) analysis. As a result of antibacterial activity, both ZnO and TiO2/ZnO have produce remarkable inhibition zone on Escherichia coli. The antibacterial activity of composites are due to the combined effect of ZnO on TiO2. The adherence and surface uniformity of TiO2/ZnO composite film on titanium implant was examined by optical microscopy and Vickers microhardness test. Corrosion resistant behavior of the coating on titanium implant was investigated by tafel polarization and impedance analysis. The composite coatings on Ti–6Al–4V have produced improved corrosion resistance with a pronou...

Hydroxyapatite [HAP] and tricalcium phosphate [s-TCP] are a class of calcium phosphate related ceramic materials that are widely used in tissue regeneration and biomedical applications owing to their excellent bioactivity and biocompatibility. In this investigation, nanocrystalline pure HAP was prepared via sol–gel method by incorporating snail shell as calcium precursor with different phosphorus sources such as triethyl phosphate/phosphite (without using any additives like pH maintaining solutions or gelling agents). Nanocrystalline HAP and biphasic calcium phosphate (HAP + s TCP) were prepared from triethyl phosphate and triethyl phosphite precursors, respectively. The prepared material was further characterized by powder XRD, IR, Raman spectroscopy, and thermo-gravimetrical analysis to confirm the phase purity, functional groups, and thermal stability. SEM coupled with EDAX was also used to examine the size, shape of particles, and elemental composition of Ca to P ratio in the material. Different phosp...

The major interest of the paper deals with the extraction of silica from four natural sources such as rice husk, bamboo leaves, sugarcane bagasse and groundnut shell. These waste materials in large quantities can create a serious environmental problem. Hence, there is a need to adopt proper strategy to reduce the waste. In the present investigation, all the waste materials are subjected to moisture removal in a hot plate and sintered at 900°C for 7 h. The sintered powder was treated with 1 M NaOH to form sodium silicate and then with 6M H2SO4 to precipitate silica. The prepared silica powders were characterized by FT-IR, XRD and SEM-EDAX analysis. The silica recovered from different sources was found to vary between 52% and 78%. Magnesium substituted silica was formed from the groundnut waste and further treatment is required to precipitate silica.

Drug treatment adherence is one of the biggest issues in tuberculosis (TB) treatment. Including DOTS (Directly Observed Treatment, Short-course) program, many programs for TB cases have yielded marginal success and the new drug resistance varieties of TB persist. During the 1960s, researchers have projected naphthoquinone–mercuric chloride (N-M) test as the single most way to objectively track the presence of isoniazid (INH) in urine and hence treatment adherence. INH is metabolised by cytochrome P450s and usually cleared from body within 8 h. Hence, the typical INH levels in biological fluids are within 1–5 μg/ml. The N-M test practically works at 10–50 μg/ml and the authors developed the sodium polyacrylate (SPA) as a solid surface to improve detection limit of INH by 6–10 fold. The modification involves absorbing the reagents of N-M test on the SPA surface and lyophilised material is directly used for diagnosis. The dry beads can detect 1–2 μg/ml of INH in saliva. The test performed with spiked as well as clinical samples and the results have good correlation. This new test has a realistic chance of tracking the TB treatment adherence remotely and in that direction a system was projected for implementation.

The objective of this study is to evaluate the biocompatibility of composite powder consisting of silica and titania (SiO(2) –TiO(2)) for biomedical applications. The advancement of nanoscience and nanotechnology encourages researchers to actively participate in reinvention of existing materials with improved physical, chemical and biological properties. Hence, a composite/hybrid material has given birth of new materials with intriguing properties. In the present investigation, SiO(2) –TiO(2) composite powder was synthesised by sol‐gel method and the prepared nanocomposite was characterised for its phase purity, functional groups, surface topography by powder X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR) and scanning electron microscopy. Furthermore, to understand the adverse effects of composite, biocompatibility test was analysed by cell culture method using MG63 osteoblast cell lines as a basic screening method. From the results, it was observed that typical Si–O–Ti peaks in FT‐IR confirms the formation of composite and the crystallinity of the composite powder was analysed by XRD analysis. Further in vitro biocompatibility and acridine orange results have indicated better biocompatibility at different concentrations on osteoblast cell lines. On the basis of these observations, we envision that the prepared silica–titania nanocomposite is an intriguing biomaterial for better biomedical applications.

Pesticide residue in fruits & vegetables is one of the key issues affecting the export of rural products in India. Pesticide exposure or intake causes major nervous system problems in children. The solutions to quantitate them in field are rare and the pesticide residue detection in the parts per billion (ppb) ranges is challenging. Except ELISA, none of the existing methods can detect pesticide residues in ppb range in the field. We employed a new approach of concentrating field samples and used sodium polyacrylate (SPA) as water absorbing material. The SPA beads concentrate the field samples and obtained a sub ppb range detection using an existing FPIA system and could improve overall sensitivity by 10-100 fold. The developed assay can be done in few seconds. We have used three pesticides 2,4-D, atrazine and methyl parathion with 0.1, 0.5 and 3 ppb detection limit respectively. We developed a simple field ready FPIA device and used sodium poly acrylate (SPA) in this biochemical FPIA to enhance sensitivity. Our tests with spiked field samples offers a possibility of using SPA concentration assisted FPIA in field. This study will have far reaching applications of both qualitative & quantitative analysis chemical analytes in field samples.

This work describes the nitric acid catalysed synthesis of wollastonite (CaSiO3) nanoparticles (NP) from tetra ethyl ortho silicate and calcium nitrate tetra hydrate. The formed calcium silicate nanoparticles were characterized by Fourier transforms infra-red spectroscopy (FT-IR), Powder X-ray Diffraction (PXRD) and scanning electron microscopy (SEM) equipped with X-ray micro analysis. The CaSiO3 NPs showed an excellent yield (93%) towards the synthesis of quinolines via Friedlander reaction. The synthesised compound 3-dimethyl-7-nitro-9-phenyl-3,4-dihydroacridin-1(2H)-one was characterized by various spectroscopic techniques.