•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.
Osteoregeneration and bacterial infection remains a major challenge in current clinical practice despite, many advanced strategies significantly developed so far. The combination of bioactive ...molecules and nano topology design can favour osteoinducivity that holds a greater potential as a bone substitute and minimize implant failure due to burst antibacterial effect. Here, we have reported a novel design of sandwich-like layered silver doped mesoporous silica nanofibers stuffed with an antibiotic drug combined with silk fibroin to boost the synergistic effect. We have investigated the physiochemical property of CEM incorporated sandwiched scaffolds by in vitro biomineralization, tensile strength, antibacterial efficacy against Escherichia coli and Staphylococcus aureus bacterial strains, in vitro degradation, osteogenic effects (MTT assay using MG63 cell line and ARS staining). In conclusion, the faster degradation of monolayered nanofibrous scaffold by incorporating the sandwich technique was minimized. The combination of CEM/SF embedded Ag@mesoporous silica sandwich layered nanofibers showed a synergistic antibacterial effect due to the sustained release of drug from the middle layer with no burst release. The development of sandwich technique for the nanofibrous scaffolds could be a viable candidate for bone regeneration and defect repair.
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•A novel strategy of gradual elution of antibiotic from sandwiched nanofibers by varying the antibiotic drug concentration.•Drug with SF in the middle layer showed prolonged antibacterial resistance, minimized burst release, more osteogenic effects.•The electrostatic interactions of drug/SF and its synergistic action with Ag enhanced the biological/mechanical properties.•Sandwich model nanofiber resulted in sustained biodegradation with more hydrophilicity to favour cell adhesion/proliferation.
Physical exercise can improve outcomes for people with first-episode psychosis (FEP). Co-designing physical exercise interventions with end users has the potential to enhance their acceptability, ...feasibility, and long-term viability. This study’s objective was to use experience-based co-design (EBCD) methodology to develop a physical exercise intervention for FEP, and pilot test it.
The study was conducted at the Schizophrenia Research Foundation’s FEP program in Chennai, India. Participants(N=36) were individuals with FEP and their caregivers, mental health professionals (MHPs, and physical training experts. EBCD methodology included one-to-one interviews, focus group discussions, joint conferences, and co-design workshops. Two instructional videos were developed. Twelve FEP patients engaged in physical exercise with help of the videos over three months. They were followed up through weekly phone calls and in-person interviews to capture data on regularity, frequency, location of exercise, and comfort levels.
Several touch points emerged from the interviews, focus groups, and joint meetings including lack of motivation, knowledge about physical exercise; differing perspectives about physical exercise; limited resource, and time constraints. Two instructional videos demonstrating activities for participants incorporated strategies that addressed these touch points. Pilot data indicated that participants engaged with the physical exercise intervention over 3 months.
This was the first study to use co-design methodology to design a physical exercise intervention for first-episode psychosis. The intervention may have therefore been responsive to stakeholder needs and preferences. Results of this study highlight the potential of co-design in designing and adapting interventions. There is need for rigorous testing with larger samples.
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•Gadolinium with more than 6% molar concentration have shown secondary phase with parent material.•The in-situ availability of Gd with its T1 and T2 weighted contrast capabilities ...might reduce the substantial risk of administration of contrast agents.•X-ray CT scans and Cellular biocompatibility of the optimized sample (3x) showed favourable results compared with other compositions.•Gadolinium substitution doesnot in any form interfere with bone regenerative biochemistry as seen with in-vitro SBF treatment studies.
The ability to acquire in situ magnetic resonance properties in biological apatites to facilitate real time MRI was investigated by substituting a series of hierarchically increasing Gadolinium over Strontium in the study. Samples were synthesized using an aqueous sol–gel pathway to ensure maximum reactivity and favour Silica-based species. Structural features were investigated using diffraction and IR spectra followed by VSM to calculate magnetization as a function of the field revealing the paramagnetic behaviour of the samples when doped. Morphological features visualized through FE-SEM showed sustained structural integrity of parent material characteristic of the P63/M space group and the EDAX spectra confirmed the hypothesised substitution when sintered as well. When immersed with SBF a loss of secondary phases and formation of amorphous calcium phosphate flakes were confirmed by diffraction and morphological studies. Biocompatibility was evaluated against first contact cells i.e. RBC via haemolytic study and L929 cells wherein Alamar assay show the samples least toxic at 25 μg/ml beyond which cell viability decreases providing enough evidence of applicability of Strontium phosphosilicate as a bioactive ceramic.
Titanium alloys, especially Ti–6Al–4V, were reported as a promising biomaterial featuring excellent corrosion resistance and good biocompatibility, but it lacks anti-infection capacity and ...osseointegration. In this work, we aimed to improve the bio-functions and corrosion resistance of AT-Ti-6Al–4V by applying cerium incorporated hydroxyapatite using a spin coater. The triple layer of Ce-HAP coatings was systematically accumulated using different speeds such as 2000, 3000 and 4000 RPM, which were sintered for 2 h at 500 °C. XRD and SEM-EDS characterize the developed Ce-HAP coatings to confirm the phase formation and surface morphology. The Colony Forming Unit confirms that Ce-HAP coatings exhibited significant inhibition efficiency towards the pathogens. In vitro bioactivity study evaluated in SBF indicates excellent apatite layer formation on Ce-HAP coatings. The cell viability studies using MG-63 cells showed good cell proliferation and attachments on a coated implant. The electrochemical properties of coatings were analysed by EIS and the result displayed pronounced anti-corrosion property. This study suggests that the cerium incorporated HAP promotes bioactivity with rapid osteointegration and presented higher corrosion resistance that makes it essential for the desired biomedical applications.
•The sol-gel derived Ce-HAP coating was Fabricated on Ti–6Al–4V alloy using spin-coating techniques.•Ce-HAP coating supports the bioactivity with enhanced ball like apatite crystals.•Polarization and EIS studies of Ce-HAP coating revealed improved corrosion resistance in SBF.•Novel approach of Ce-releasing antibacterial coatings to reduce the infection in orthopaedic implants has been studied.•Biocompatibility study proved excellent MG-63 cells proliferation with good cell adhesion on the coating surface.
Sol-gel derived silica glasses have many promising features, including low-temperature preparation as well as chemical and physical stability. Two silica glasses with Si
100
and Si
80
composition ...were prepared to understand the factors contributing to the rate of bioactivity. The effects of pH, solution aging temperature, and molar ratio of H
2
O/tetraethyl orthosilicate (TEOS) were studied, and the obtained powder sample was characterized by Fourier transform infrared spectroscopy, X-ray diffraction studies, and scanning electron microscopy. The synthesized silica glasses were deposited on 316L SS by the spin coating method at the optimized speed of 2000 revolutions per minute. The corrosion resistance behavior of the coatings was determined by (1) open-circuit potential
vs
time of exposure, (2) electrochemical impedance spectroscopy, and (3) cyclic polarization in Ringer’s solution. A higher breakdown potential (
E
b
) and repassivation potential (
E
p
) value with lower current density was obtained from cyclic polarization. Similar results were observed from impedance analysis with higher charge transfer resistance (
R
ct
) and lower double layer capacitance (
C
dl
) indicating the corrosion resistance behavior of the coatings compared with the uncoated 316L stainless steel. From the results, it was observed that both Si
100
and Si
80
glass coatings had a positive effect on the corrosion resistance behavior. An adhesive strength of 46 MPa and 45 MPa was obtained for the Si
100
and Si
80
coatings, respectively. An accelerated leach out study was carried out by impressing the potential at their breakdown potential to determine the effect of glass coating for long-term contact between the implant and a normal biological medium.
Sodium polyacrylate (SPA) is a popular super absorbent commonly used in children diapers, sanitary pads, adult diapers etc. The use of SPA is in force from past 30 years and the newer applications ...like as food preservant are evolving. SPA is recently discovered by our group for improvement of sensitivity of colorimetric agents. Though the discovery of improvement in sensitivity is phenomenal, the mechanism still remains a puzzle. A typical assay reagent contains colorimetric/fluorescent reagents, buffers, salts, stabilizers etc. These chemicals are known to influence the water absorptivity of SPA. If we were to perform chemical/biochemical assays on SPA absorbed reagents effect of salts and other excipients on colorimetric/fluorescence compounds absorbed on SPA is very important. The hofmeister series are standard for studying effect of salts on permeability, stability, aggregation, fluorescence quenching etc. We recently studied affect of urea, sodium chloride, ammonium sulfate, guanidine thiocayanate on fluorescence characteristics of fluorescence compounds and noted that except urea all other reagents have resulted in fluorescence quenching and urea had an opposite effect and increased the fluorescence intensity. This result was attributed to the different water structure around fluorescent in urea solution versus other chaotropic agents.
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/cm
2
), 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/cm
2
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.
Silk fibroin (SF) based biomaterials have received more attention due to SF's superior biocompatibility, biodegradability, and special properties such as a minimal inflammatory reaction and low ...immunogenicity especially for the development of bioactive scaffolds in bone regeneration applications. To date, Silk fibroins are blended with a variety of biocompatible polymers and inorganic materials, to enhance their in vitro and in vivo properties. This study includes the detailed protocol of extracting silk fibroin from Bombyx mori silk cocoons followed by the degumming process using aqueous Na2CO3. Hydroxyapatite was synthesized by co-precipitation method using NH4H2PO4 and Ca(NO3)2. 4H2O, later it was blended with extracted silk fibroin and Polyvinyl alcohol (PVA) solution to fabricate desire nanofibers/scaffolds. The viscosity of the blended solution was tuned at an appropriate concentration for the preparation of nanofibrous scaffold by electrospinning and freeze-dried method. The obtained scaffolds were further characterized by FT-IR, XRD, and SEM to confirm the functional groups, phase formation, porosity, and surface morphology. Cell viability was evaluated using MG-63 cell lines and in -vitro bioactivity was further evaluated by immersing in simulated body fluid (SBF) solution. Drug loading and releasing profile of scaffolds were examined using Cephalexin Monohydrate (CEM) in PBS medium. The results inferred that the prepared PVA/HAP/SF based scaffolds showed better osteogenic cell proliferation with prolonged drug release, Hence, this optimized nanofiber may act as an effective material for bone tissue engineering applications.
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•Silk fibroin from Bombyx mori cocoons was extracted in an alkaline solution to remove glue-like sericin via dialysis.•The influence of silk in different nanofibers/scaffolds were compared by In-vitro drug loading and releasing efficiency.•The compression strength of freeze dried and tensile strength of electrospun showed excellent result due to β sheet of SF.•Comparatively, electrospun nanofibrous scaffolds have shown excellent outcomes due to the presence of a porous network.
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