Samples In Simulated Body Fluid Research Articles

Assessment of Physicochemical Characterization and Mineralization of Nanofibrous Scaffold Incorporated With Aspartic Acid for Dental Mineralization: An In Vitro Study.

Aim The aim of this study was to assess the physicochemical characterization and mineralization of nanofibrous scaffold incorporated with nanohydroxyapatite (nHA) and aspartic acid (Asp) for dental mineralization. Methodology Three nanofibrous scaffolds were prepared, namely polycaprolactone (PCL), PCL with nHA, and PCL with nHA and Asp. Each scaffold was prepared separately by electrospinning. The physicochemical characterization of the surface of the nanofibrous scaffold was imaged using a scanning electron microscope (SEM), energy dispersive X-ray Analysis (EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). In vitro mineralization studies were performed by immersing the sample in simulated body fluid (SBF) for 7, 14, and 21 days. The surface of the samples was observed under SEM with EDX. Results SEM analysis of PCL/nHA/Asp revealed that the nanofibers were bead-free, smooth, randomly oriented, and loaded with Asp. The EDX spectra of PCL/nHA/Asp composite nanofibrous scaffold revealed broad peaks and corresponded to the amorphous form, while the sharp peaks corresponded to the specific crystalline structure of nHA. FTIR analysis showed specific functional groups corresponding to PCL, nHA, and Asp. The scaffolds incorporated with Asp exhibited higher mineralization potential with an apatite-like crystal formation, which increased with an increase in the duration of immersion in SBF. Conclusion Physiochemical characterization demonstrated the incorporation of PCL/nHA/Asp in the electrospun nanofibrous scaffold. The mineralization analysis revealed that the presence of Asp enhanced the mineralization when compared with the PCL and PCL/nHA. PCL/nHA/Asp incorporated in scaffold can be a promising material for dental mineralization.

Investigating the Degradation Behavior of Grain Refined WE43 Magnesium Alloy Produced by Friction Stir Processing for Medical Implant Applications

Developing Magnesium (Mg) based degradable implants for orthopedic applications is an attractive research area for the past two decades in the biomedical engineering. Mg is well accepted by human system and does not cause any health abnormalities during its degradation in the physiological environment. However, in order to improve its life span by controlling the aggressive degradation, novel Mg alloys are developed and subjected to different treatments to enhance their performance to tailor as promising candidates for implant manufacturing. In this context, recently, a special attention is paid towards using rare earth containing Mg alloys due to their excellent mechanical and corrosion resistance properties. Hence, in the present work, WE43 Mg alloy has been selected and the microstructual modification was carried out by friction stir processing. The role of grain refinement on the degradation behavior of FSPed WE43 Mg alloy was assessed by immersing the samples in simulated body fluids. From the microstructural studies, grain size reduction from 46 ± 4.2 µm to 16.1 ± 5.4 µm was achieved after FSP. The larger intermetallic particles were also observed as dissolved into the solid solution grains and fewer intermetallic particles were remained in the stir zone of FSPed alloy. After immersion studies, the surface of the samples was deposited with mineral phases and were analyzed by X-ray diffraction analysis and scanning electron microscope and found that the grain refinement achieved by FSP has a significant effect on increasing the mineral depositions which helps to control the degradation rate of the samples.

Effect of systematic substitution of Na2O for SiO2 on devitrification and bioactivity of sol-gel derived 69.5SiO2-24.5CaO-6P2O5 ceramics

Addition of Na2O to SiO2–CaO–P2O5 glass-ceramics significantly impacts in-vivo dissolution and structural network modifications. However, achieving a vitreous state in sol-gel derived quaternary oxide powders, like the 45S5 bioglass containing high amounts of Na2O, is challenging. Synthesis of (69.5-x)SiO2-24..5CaO-6P2O5-xNa2O (x = 0, 2, 4, 8, 12, 16, 20, and 24.5 wt.%) ceramic powders has been carried out followed by heat-treatment between 500 °C and 700 °C. Structural characterization revealed that the vitreous state could be stabilized for Na2O content up-to 12wt.%. For higher Na2O content, the network transformed to a glass-ceramic state with the crystallization of combeite phase. In-vitro tests exhibited hydroxyapatite layer formation (Ca/P = 1.67) on all samples in simulated body fluid, regardless of structure. Samples were non-toxic to MG-63 osteoblast cells. The devitrification, bioactivity and associate properties of the quaternary system as a function of Na2O content is discussed with respect to envisaged biomedical applications.

Bioactive Fe Foam for Degradable Bone Graft Cages

Fe foams when combined with a proper surface coating can be effectively used as a biodegradable metal with improved biocompatibility and bioactivity. Herein, Fe foams prepared via powder metallurgy route coated with two different bioactive coatings namely polyvinyl alcohol (PVA)/bioglass (BG) and polylactic acid (PLA)/BG are investigated. The effect of hydrophilic PVA and hydrophobic PLA, in conjunction with BG, has been examined. The study of biomineralization, degradation, and weight loss of the composite‐coated material over a period of 28 days is compared with that of the uncoated Fe foam samples in simulated body fluid. The composite coatings on the Fe foam effectively tailor the degradation with enhanced biomineralization. The composite‐coated material exhibits viability toward the L929 fibroblast cell line. The work reveals the great potential of Fe foams to be used as a biodegradable metallic material for temporary implant applications such as bone graft cages.

Design, fabrication, evaluation, and in vitro study of green biomaterial and antibacterial polymeric biofilms of polyvinyl alcohol/tannic acid/CuO/ SiO2

In this study, a three-component biofilm for rapid wound dressing consisting of polyvinyl alcohol (PVA)/tannic acid (TA)/with CuO/SiO2 with different percentages (0, 5, 10, and 15 wt% NPs) is evaluated. In addition to controlling bleeding and absorption of blood and wound secretions, it protects the damaged tissue from the attack of microbes. It protects against viruses and thus reduces the treatment time. Analysis of biofilms morphology is performed by Field emission scanning electron microscopy (FE-SEM), phases in biofilms were analyzed by X-ray diffraction (XRD) analysis, chemical bonds, and functional groups are analyzed by Fourier transform infrared (FTIR) spectroscopy, and mechanical tests are performed to evaluate the strength of the samples. The thermogravimetric analysis (TGA) is applied to estimate the thermal stability of the biopolymer films with various percentages of CuO/SiO2 nanoparticles. Also, antibacterial test, bioactivity of the biofilms, the percentage of swelling ratio, and porosity of the samples were examined by immersing the samples in simulated body fluid (SBF) and Phosphate-buffered saline (PBS) for 14 days in vitro. The composite makeup of the TA/PVA sample, comprising 15 wt % CuO/SiO2 and containing 15 wt% of nanoparticles, exhibited superior heat resistance compared to other samples by an increase of 50 °C. This improvement can be attributed to the nanoparticles reaching their saturation point. The swelling ratio was assessed in both SBF and PBS, and in both instances, the sample increased by up to 10 wt% before decreasing, indicating the saturation of the nanoparticles.

Investigating wettability and corrosion resistance of the titanium alloy surface engineered by the WEDM process

Ti-6Al-4V or the grade 5 titanium alloy, is widely used as a biomedical implant material because of its high specific strength and corrosion resistance. The formation of oxide layer over the Ti-6Al-4V alloy produced by electrical discharge machining (EDM) process was reported to act as a corrosion barrier and promote biocompatibility. In this study, surface engineering was conducted by machining micro-channels and micro-pillars over Ti-6Al-4V surface using wire-EDM (WEDM) process to investigate surface topography, corrosion resistance and wettability for improved biocompatibility. Four different samples were produced using varied micro features and varied surface topography generated by WEDM. Two of the samples were prepared by multi-pass surface finishing before fabricating micro-patterns on the surface, whereas the other two samples containing micro-patterns were first machined by single pass WEDM process. The corrosion testing was carried out on fabricated samples in simulated body fluid. Surface wettability of the engineered Ti-6Al-4V samples were carried out by measuring water contact angles of the surfaces. Surfaces with micro-channels and micro-pillars with multi-pass surface finishing provided better results in terms of corrosion resistance compared to the samples prepared by conventional WEDM process. The machined surface with micro-channels that underwent multi-pass finishing exhibited the highest corrosion resistance as well as the highest water contact angle among the four samples.

The effect of addition of K2ZrF6 on the structures and properties of AZ31 magnesium alloy MAO coating

It is a challenge to improve the corrosion rate and blood compatibility of biomedical magnesium alloy implants in human body. Scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD) were used to study the Properties of K2ZrF6 modified AZ31 magnesium alloy composite coating. The corrosion behavior of the sample in simulated body fluid (SBF) was evaluated by hydrogen evolution corrosion, potentiodynamic polarization cur ve and electrochemical impedance spectroscopy. The results show that the corrosion resistance of magnesium alloy is significantly improved by composite coating. The wettability test shows that K2ZrF6 greatly improves the biocompatibility of MAO coating on magnesium alloy. The hemolysis test shows that the composite coating makes magnesium alloy have low hemolysis rate. The increase of PH value and magnesium ion concentration in solution caused by corrosion of magnesium alloy can be adjusted by adding K2ZrF6. The corrosion resistance mechanism of MAO coating on K2ZrF6 modified magnesium alloy was discussed. In this experiment, the optimum amount of K2ZrF6 is 4 g/L.

Analysis of amorphous structure with polycaprolactone-hydroxyapatite nanoparticles fabricated by 3D bioprinter technique for bone tissue engineering

New ceramic scaffolds have the ability to be designed to replace the hip bone with different shapes. In this research, the aim is to fabricate a porous scaffold by fused deposition modeling (FDM) with three geometric shapes of circle, multi-circle and square for bone replacement applications. Biological tests included immersing the samples in simulated body fluid (SBF) to monitor the apatite formation and phosphate buffer saline (PBS) to check weight loss and ion concentration changes. Morphological examination was evaluated by examining the surface of the sample before and after immersion in the SBF using scanning electron microscope (SEM) analysis. The obtained mechanical results such as elastic modulus and compressive strength were used in the finite element analysis (FEA). The mechanical results showed that the sample with a multi-circle structure have a higher elastic modulus under the compressive strength about 32 MPa. Also, the porosity percentage showed that the highest porosity belongs to the second sample. The stress-strain results show that the second sample has a compressive strength of about 2.6 MPa. The FEA of the samples show that the sample with square structure has the highest stress compared to the other sample. The apatite growth in all three samples had similar trend. The mechanical and morphological analysis shows the fracture surface of the bone scaffold under compressive loading for the third sample has porosity of about 42% and the lowest compressive strength of about 1.85 ± 0.8 MPa. In order to reduce the amount of remain stress, the first and second samples should be used for the pelvic bone repair.

High performance nano hydroxyapatite coating on zinc for biomedical applications

Zinc and its alloys have been given promising consideration as a new biodegradable implant for use in the human body. Compact and uniform nano hydroxyapatite coatings containing chitosan were successfully deposited onto zinc substrate in an aqueous solution utilizing microwave-assisted process in about 10 min. The quick composite coatings are derived by microwave heating compared with the coatings derived by electrodeposition. The as-deposited coatings formed by electrodeposition synthesis were known as brushite, which was converted to hydroxyapatite after 1 h of immersion (post treated) in 1 M aqueous sodium hydroxide solutions at 100 °C. The incorporation of chitosan (from 0.01–0.05 g/l) into the coating composition results in a smooth and uniform coating structure. SEM, EDS, and an X-ray diffractometer were utilized to analyze coated samples' surfaces to evaluate their surface morphology, chemical composition, and crystalline structures. The in vitro degradation behavior of the composite-coated samples in simulated body fluid at pH 7.4 and 37 °C was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization. The outcomes showed that microwave-derived coatings provided superior corrosion resistance for zinc implants as compared to electrodeposited coatings. Furthermore, the use of chitosan in hydroxyapatite coatings increased electrochemical corrosion performance. Low chitosan concentrations (0.01–0.03 g/l) exhibit superior anti-corrosion properties than higher concentrations (0.05 g/l). Against Staphylococcus aureus, the coatings demonstrated strong antibacterial efficacy. These corrosion outcomes and the fruitful deposition of a hydroxyapatite/chitosan composite coating on zinc substrate indicate that the coating is efficient for the creation of new composite coatings for either functional implants or regenerative medicine. The resultant coating may be an excellent option for bone implants.

In vitro bioactivity and biocompatibility of magnesium implants coated with poly(methyl methacrylate) - bioactive glass composite

Magnesium (Mg) and its alloys have proved promising as biodegradable candidates for the repair of bone tissue. Despite the encouraging bio-related properties of Mg, its high corrosion rate in contact with body fluids still presents a major challenge. An efficient approach to address this issue is to provide a protective coating on Mg. The present research evaluates, for the first time, in vitro bioactivity and biocompatibility of a novel multifunctional composite coating based on poly(methyl methacrylate) (PMMA) biopolymer and bioactive glass (BG) particles on Mg-based implant. Electrophoretic deposition (EPD) was utilized to obtain this coating from a bi-component suspension. Coatings’ morphological analyses by scanning electron microscopy established that EPD provides a facile route for simultaneous deposition of the biopolymeric matrix and BG in the form of a dense and homogeneous coating on the surface of Mg. Chemical characterizations of the coatings performed by energy-dispersive spectroscopy and FT-IR spectroscopy confirmed the presence of both PMMA and BG components in the composite film. In vitro acellular bioactivity test in simulated body fluid (SBF) verified bone-like apatite formation on coatings due to the presence of BG particles. Additionally, in vitro cellular cytotoxicity using MTT assay demonstrated cellular viability in contact with the composite coatings. Moreover, the corrosion behavior of the pure Mg vs coated Mg samples in SBF was assessed electrochemically using linear polarization and impedance spectroscopy techniques. A significant increase in the polarization resistance from 65.89 Ω.cm 2 for uncoated Mg to 1365.1 Ω.cm 2 for Mg coated with a composite film (obtained from 45 g/L PMMA and 3.5 g/L BG suspension) was observed. This indicated a reduction of 95.17% in the corrosion rate of Mg substrate by application of a composite coating. The dramatic reduction in Mg substrate corrosion rate accompanied by in vitro bioactivity and cytocompatibility of the developed composite, reflect the high potential of the present strategy in the modification of Mg-based implants for successful bone tissue engineering applications. • Novel bioactive and corrosion-resistant composite coating on Mg biomedical implant • PMMA facilitates bioactive glass deposition via a facile electrophoretic method • Composite coatings were bioactive due to apatite formation in simulated body fluid • 95.17% reduction in corrosion rate in composite-coated Mg vs bare Mg • Coatings supported the growth of MG63 cells and were non-cytotoxic

Insights of Microstructural Features and Their Effect on Degradation and the In Vitro Bioactivity Response of as-Cast Mg-Sn Alloys for Orthopedic Implant Applications.

The present work focuses on a deep understanding of microstructural evolution and phase formation in a binary Mg-Sn alloy system. Mg-xSn (x = 1, 5, 10 wt.%) alloys were cast using a squeeze casting technique. Phase identification and microstructural analysis were done using XRD (X-ray Diffraction) and FESEM with EDS (Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy), respectively. The mechanical behavior of the alloys under study was evaluated by conducting a compression test. The corrosion behavior of all the alloys were intricately studied using electrochemical corrosion tests and an immersion test in the simulated body fluid (SBF) environment for different immersion periods. The bioactivity response of Mg-Sn alloys systems under this study was investigated by immersing the samples in SBF for 14 days. From the analysis of the results, it was understood that the amount of Sn addition has a large influence on the metallurgical, corrosion, and bioactivity properties. Interesting facts about the intermetallic phase formation and segregation of Sn were observed when the wt.% of Sn was varied in the alloy and the evolution of the microstructure was described clearly. Mechanical properties of Mg-Sn alloys were improved, as the Sn content increased up to 5 wt.% and declined in the case of a 10 wt.% Sn addition. A similar trend was observed even in the case of corrosion resistance and bioactivity properties. Among the alloy compositions studied, Mg with a 5 wt.% addition has proved to be a promising candidate material for orthopedic implant applications with an acceptable elastic modulus, higher corrosion resistance, and an excellent bioactive response.

Influence of Si3N4 and CuO Nanoparticles on the Microstructure and Properties of Multiphase Graphite Oxide/Hydroxyapatite/Sodium Alginate Coatings Obtained By Electrophoretic Deposition on Titanium Alloy

In this work, we report an electrophoretic deposition path for efficient fabrication of advanced multiphase coatings, consisting of Ca cross-linked sodium alginate with graphite oxide n-GtO flakes mixed into bioactive hydroxyapatite and CuO or Si3N4 antibacterial nanoparticles. Anionic sodium alginate molecules ensured electrosteric stabilisation of the suspension. The effects of the chemical composition of the suspension and deposition parameters on coating morphology were investigated. Hydroxyapatite and antibacterial agents formed agglomerates fairly well spread within the alginate matrix. The coatings with Si3N4 incorporation presented outstanding adhesion to the Ti-13Nb-13Zr alloy substrates. All coatings revealed hydrophilic surfaces and showed a high ability to protect the alloy substrates from corrosion in Ringer’s solution. A hydroxyapatite layer was formed as a result of soaking the coated samples in simulated body fluid for 3 weeks. CuO-containing samples showed significantly improved antibacterial properties against E. coli. The incorporation of n-GtO alone did not induce any cytotoxic effects of the coatings against MG-63 cells but its combination with CuO and Si3N4 reduced the cell viability. However, this behaviour was much more pronounced for the CuO-containing coatings. This work demonstrates the outstanding development potential of electrophoretically deposited multifunctional coatings with potential application in long-term titanium bone implants.

Impact of silver on fluorophosphate glasses to improve in vitro bioactivity and antibacterial efficacy

This article discusses the effect of silver oxide (Ag2O) on structural changes, apatite-forming ability, and bioactivity during addition onto the fluorophosphate glass (FPG) network. The foremost objective of silver incorporation on to fluorophosphate glass is to enhance the antibacterial efficacy of glass material which can be widely used as implants to minimize the post-surgical infections. Silver-added fluorophosphate glasses (AFPGs) with composition of 48P2O5–29CaO−(20−x)Na2O–3CaF2−xAg2O (x = 0, 0.3, 0.6, 0.9, and 1.2 mol%) were prepared using conventional glass-melting method followed by rapid quenching technique. The in vitro apatite-forming ability of AFPG was evaluated by immersing the samples in simulated body fluid (SBF) for 21 days. The pH variations of the SBF solution were noted throughout the in vitro study and plotted to estimate dissolution mechanism. The structural properties and compositional estimation of AFPG samples before and after in vitro study were analyzed using X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Cytotoxicity of the prepared AFPG samples was evaluated using MTT assay. The bacteriostatic effect of AFPG samples were studied using different strains of bacteria such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus, S. epidermidis, and S. mutans. The obtained peaks from XRD analysis at 28.12°, 31.73°, 46.71°, 29.11°, 32.25°, 51.59°, and 67.49° confirm crystalline nature and apatite formation on the glass surface. The attained characteristic FTIR peaks at 560 and 600 cm −1 shows the presence of apatite groups of vibration. The SEM image infers the spherical structure on the glass surface representing the presence of apatite layer and the EDAX graph shows the elemental composition of the prepared glass surface. From the present study, it was noted that glass sample containing 0.9 mol % of Ag2O enhanced apatite formation, was less cytotoxic and showed better antibacterial activity. Thus it can be inferred that AFPG0.9 sample can play a significant role in biomedical applications.

Improving the tribocorrosion performance of plasma electrolytic oxidized coatings on AZ31B magnesium alloy using pullulan as an electrolyte additive

This study aimed to investigate the enhancement of the corrosion and tribocorrosion performance of AZ31B magnesium (Mg) alloys after plasma electrolytic oxidization (PEO) treatment using pullulan as an electrolyte additive. The effects of different concentrations of pullulan in the electrolyte solutions on the mechanical and corrosion-resistance properties of the PEO coatings were investigated. The microstructures and chemical compositions of the coatings were investigated via scanning electron microscopy, energy dispersive spectrum, and X-ray diffraction. The corrosion resistance of the samples in simulated body fluid was evaluated via potentiodynamic polarization and electrochemical impedance spectroscopy. The tribocorrosion performance was determined by simultaneously recording the change in the friction coefficient and the open circuit potential over time during sliding experiments. The results indicated that the addition of pullulan to the silicate-based electrolyte solutions resulted in an increase in the unit-area adsorptive capacity of the negative ions at the anode/electrolyte interface, which enhanced the compactness of the PEO coating. The PEO coating produced in electrolyte solution containing 1.0 g/L pullulan exhibited the greatest thickness (50 μm), the lowest surface roughness (1.25 μm), the highest corrosion resistance, and the best anti-tribocorrosion performance, all of which corroborated the potential application of PEO-coated Mg alloys as biological implants.

Investigation the mechanical properties of a novel multicomponent scaffold coated with a new bio-nanocomposite for bone tissue engineering: Fabrication, simulation and characterization

Due to the vital functions of bone tissue in the body, any change in its structure affects the balance of the body. Following a lesion, the body may be unable to repair it, and bone scaffolds may be implanted to stimulate bone cells and thus repair lost bone. This article aims to develop a scaffold with ideal properties that can be used to treat fractures and injuries. The technique used in this study is a hybrid of 3D printing and freeze-drying. Alginate (ALG), polyvinyl alcohol (PVA), and bioceramic-titanium nanoparticles were used to coat electroconductive polylactic acid (EC-PLA) using the freeze-drying method. The prepared samples were analyzed using a scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) for morphology functional group and phase characterizations. After coating the scaffolds with the freeze-drying method, the pore size was examined and correlated with the compressive strength values. For biological studies, a bioactivity test involving immersion of the samples in simulated body fluids (SBF) was performed for a specified period. The samples were then evaluated for water absorption, weight loss, and pH changes. Cell behavioral and antibacterial tests were performed to evaluate the growth of scaffolds in the body. Additionally, the compressive strength test results are incorporated into simulation and modeling analyses under static loading and micromechanical models. Finally, the circle-shaped scaffold containing titanium sample was chosen as a suitable scaffold due to its 78% porosity, 27% apatite formation, 75° wetting angle, 15% weight loss after 7 days, and 99% biocompatibility. Finally, the bio-nanocomposite scaffold can attach to the cell and then gradually degrade, preserving the implant's mechanical properties for the regeneration process.

3D Printing of Macro Porous Sol-Gel Derived Bioactive Glass Scaffolds and Assessment of Biological Response.

3D printing emerged as a potential game-changer in the field of biomedical engineering. Robocasting in particular has shown excellent capability to produce custom-sized porous scaffolds from pastes with suitable viscoelastic properties. The materials and respective processing methods developed so far still need further improvements in order to obtain completely satisfactory scaffolds capable of providing both the biological and mechanical properties required for successful and comprehensive bone tissue regeneration. This work reports on the sol-gel synthesis of an alkali-free bioactive glass and on its characterization and processing ability towards the fabrication of porous scaffolds by robocasting. A two-fold increase in milling efficiency was achieved by suitably adjusting the milling procedures. The heat treatment temperature exerted a profound effect on the surface area of mesoporous powders. Robocasting inks containing 35 vol.% solids were prepared, and their flow properties were characterized by rheological tests. A script capable of preparing customizable CAD scaffold geometries was developed. The printing process was adjusted to increase the technique’s resolution. The mechanical properties of the scaffolds were assessed through compressive strength tests. The biomineralization ability and the biological performance were assessed by immersing the samples in simulated body fluid (SBF) and through MTT assays, respectively. The overall results demonstrated that scaffolds with macro porous features suitable for bone ingrowth (pore sizes of ~340 μm after sintering, and a porosity fraction of ~70%) in non-load-bearing applications could be successfully fabricated by 3D printing from the bioactive glass inks. Moreover, the scaffolds exhibited good biomineralization activity and good biocompatibility with human keratinocytes, suggesting they are safe and thus suited for the intended biomedical applications.

Natural Drug-Loaded Bimetal-Substituted Hydroxyapatite-Polymeric Composite for Osteosarcoma-Affected Bone Repair.

Repairing segmental bone deformities after resection of dangerous bone tumors is a long-standing clinical issue. The study’s main objective is to synthesize a natural bioactive compound-loaded bimetal-substituted hydroxyapatite (BM-HA)-based composite for bone regeneration. The bimetal (copper and cadmium)-substituted HAs were prepared by the sol-gel method and reinforced with biocompatible polyacrylamide (BM-HA/PAA). Umbelliferone (UMB) drug was added to the BM-HA/PAA composite to enhance anticancer activity further. The composite’s formation was confirmed by various physicochemical investigations, such as FT-IR, XRD, SEM, EDAX, and HR-TEM techniques. The bioactivity was assessed by immersing the sample in simulated body fluid for 1, 3, and 7 days. The zeta potential values of BM-HA/PAA and BM-HA/PAA/UMB are −36.4 mV and −49.4 mV, respectively. The in vitro viability of the prepared composites was examined in mesenchymal stem cells (MSCs). It shows the ability of the composite to produce osteogenic bone regeneration without any adverse effects. From the gene expression and PCR results, the final UMB-loaded composite induced osteogenic markers, such as Runx, OCN, and VEFG. The prepared bimetal substituted polyacrylamide reinforced HA composite loaded with UMB drug has the ability for bone repair/regenerations.

PREPARATION AND BIOLOGICAL EVALUATION OF PLD-BASED FORSTERITE–HYDROXYAPATITE NANOCOMPOSITE COATING ON STAINLESS STEEL 316L

The present work deals with the fabrication of forsterite–hydroxyapatite (FS–HA) hybrid coatings on stainless-steel 316L using the pulsed laser deposition (PLD) technique. The stainless steel (SS 316L) as a metallic implant is widely used in hard tissue applications. The XRD studies have confirmed the crystalline behavior of synthesized FS powder with an average crystallite size of 54[Formula: see text]nm. The synthesized FS powder was mixed in different compositions (10, 20, 30[Formula: see text]wt.%) into HA for preparing PLD targets (pellets). The XRD of the prepared pellets by UTM has confirmed both phases of FS and HA. The Scanning Electron Microscopy (SEM) of the coated samples depicted the successful deposition of composite powders on the substrates (SS 316[Formula: see text]L). The Ellipsometer was used to investigate the thickness of different substrates and it was found as 243, 251, 255, and 257[Formula: see text]nm for CP1, CP2, CP3, and CP4, respectively. The bioactivity of the coated substrates with different compositions (pure HA, 10%, 20%, 30%, and pure FS) was investigated by immersing the samples in simulated body fluid (SBF) for 14[Formula: see text]days. The same samples were then characterized by SEM which confirms the apatite layer formation that reflects the bioactivity. The addition of FS powder into HA will stimulate the apatite formation which enhances the bioactivity. The Raman Spectroscopy of coated samples reveals the successful deposition of different compositions of FS–HA nanocomposite. The peaks of Raman spectroscopy were corresponding to the XRD results of the pellets (different compositions of FS–HA). The antimicrobial activity of different compositions of FS–HA against Escherichia coli (E. coli) bacteria also showed a significant zone of inhibition. The bioactivity and antimicrobial behavior of FS–HA along with successful deposition by PLD have shown better potential applications for biomedical implant coating.

Anodizing/Anaphoretic Electrodeposition of Nano-Calcium Phosphate/Chitosan Lactate Multifunctional Coatings on Titanium with Advanced Corrosion Resistance, Bioactivity, and Antibacterial Properties

The aim of this work was to investigate corrosion resistivity, bioactivity, and antibacterial activity of novel nano-amorphous calcium phosphate (ACP) potentially multifunctional composite coatings with and without chitosan oligosaccharide lactate (ChOL), ACP + ChOL/TiO2 and ACP/TiO2 ACP + ChOL/TiO2, respectively, on the titanium substrate. The coatings were obtained by new single-step in situ anodization of the substrate to generate TiO2 and the anaphoretic electrodeposition process of ACP and ChOL. The obtained coatings were around 300 ± 15 μm thick and consisted of two phases, namely, TiO2 and hybrid composite phases. Both ACP/TiO2 and ACP + ChOL/TiO2 have improved corrosion stability, whereas the ACP + ChOL/TiO2 coating showed better corrosion stability. It was shown that at the very start of the deposition process, the formation of the ChOL/TiO2 layer takes place predominantly, which is followed by the inclusion of ChOL into ACP with simultaneous growth of TiO2. This deposition mechanism resulted in the formation of strongly bonded uniform stable coating with high corrosion resistance. In vitro bioactivity was investigated by immersion of the samples in simulated body fluid (SBF). There is in-bone-like apatite formation on both ACP/TiO2 and ACP + ChOL/TiO2 surfaces upon immersion into SBF, which was proven by X-ray diffraction and Fourier transform infrared spectroscopy. While ACP/TiO2 shows no antibacterial activity, ACP + ChOL/TiO2 samples exhibited three- to fourfold decreases in the number of Staphylococcus aureus and Pseudomonas aeruginosa, respectively, after 420 min. The probable mechanism is binding ChOL with the bacterial cell wall, inhibiting its growth, altering the permeability of the cell membrane, and leading to bacterial death.

Investigation of In-Vitro Properties of NiTi Alloy After Micro Arc Oxidation

Malzeme biliminin diğer alanlarda olduğu gibi tıp bilimine entegre olmasıyla biyomalzemelerin de çeşitliliği, gelişimi ve kullanım alanları artmaktadır. Bu çeşitlilik içerisinde yer bulan biyomalzemelerden biride NiTi alaşımlarıdır. Bu çalışma; şekil hafızalı NiTi alaşımının yüzey ve mekanik özelliklerinin iyileştirilmesi amacı ile Mikro Ark Oksidasyon (MAO) yöntemi kullanılarak TiO2 kaplamasının büyütülmesi üzerine odaklanmıştır. Büyütülen kaplamaların yapısal özellikleri SEM ve XRD cihazları kullanılarak analiz edilmiştir. Biyoaktivite özellikleri yapay vücut sıvısı (SBF) içerisinde bekletme testi analizi ile tespit edilmiştir. SBF içerisinde bekletme testleri sonrasında kaplanmış ve kaplanmamış şekil hafızalı NiTi altlıkların, bulundukları ortama Ni+2 salınımı kontrolü ise ICP-MS cihazı ile tespit edilmiştir. Büyütülen oksit tabakasıyla NiTi alaşımlarının kullanımını sınırlayan özellikleri önemli derece giderildiği gözlenmiştir. MAO yöntemiyle TiO2 kaplanmış NiTi altlıkların biyoaktif özelliklerinin arttığı ve 72. saatin sonunda hücre canlılığında NiTi altlığına kıyasla istatistik olarak herhangi bir sitotoksisiteye sahip olmadığı tespit edilmiştir.