Bone Implants Research Articles

Dual-functional superhydrophobic coatings on biodegradable Mg alloys via nano-SiO2 particles assisted surface modification

In the exploration of next-generation biocompatible implant materials, magnesium (Mg) alloys have great potential due to their inherent biodegradability. The current study delineates the development of dual-functional coatings for Mg alloys, incorporating zinc (Zn) and calcium (Ca), characterized by both anti-bacterial and anti-corrosion attributes. These coatings were synthesized by integrating surface groups of magnesium hydroxide/magnesium oxide with surface atoms of nano‑silicon dioxide (nano-SiO2) particles, leading to the formation of magnesium silicate junctions. Subsequently, these interfacial surfaces were functionalized using organofluorosilanes. With the application of the coating, a notable enhancement in the static contact angle of water from 43.7° ± 1.1° to 158.4° ± 1.3° was observed. The anti-adhesive properties of the coating against bacteria were assessed through inoculation assays with Staphylococcus aureus, a predominant agent of implant-associated infections. No bacterial colonization on the Mg4Zn0.5Ca alloy surface was detected when the dual-functional coatings were applied. While a hydrogen evolution (HE) of 4.78 mL/cm2 was measured on uncoated surfaces, the HE reduced significantly to 0.35 mL/cm2 for coated alloy surfaces. Analysis using Nyquist plots unveiled a polarization resistance of coated surfaces that was an order of magnitude higher than uncoated surfaces. As a result, Mg alloys covered with a dual-functional nanocoating layer demonstrate favorable characteristics, such as diminished corrosion rates and enhanced resistance against bacterial adhesion. Such coatings negate the necessity for subsequent surgical removal of bone implants, consequently mitigating potential bacterial infections and the concomitant medical expenses.

Silk-Fabric Reinforced Silk for Artificial Bones.

Bone implants for different body parts require varying mechanical properties, dimensions, and biodegradability rates. Currently, it is still challenging to produce artificial bones with perfect compatibility with human bones. In this study, a silk-fabric reinforced silk material (SFS) composed of pure silk with exceptional biocompatibility, osteogenesis, and biodegradability is reported, and demonstrates its outstanding performance as a bone implant material. The SFS is fabricated using a simple hot-pressing technique, with degummed silk fabric as the reinforcement and silk fibroin as the matrix. The SFS as a self-reinforced composite, has exceptional mechanical properties due to the almost perfect interface between the matrix and reinforcement. More importantly, its mechanical properties, biodegradability rates, and density can be tailored by adjusting the reinforcement structure and the ratio of the reinforcement to the matrix to align with the requirements for bone implantation in different parts of the human body. Besides, the SFS can improve osteoblastic proliferation and increase osteogenic activity, which is not the case with clinically used titanium alloy artificial bone. Therefore, the SFS holds significant potential to replace conventional metal or ceramic implants in the field of medical fracture repair.

Experimental Study of the Corrosive and Biocompatible Properties of Bioresorbable Mg-Ca-Zn Alloy Implants

Introduction. Magnesium and its alloys are used as biodegradable bone implants due to their high biocompatibility, however, the problem of use is rapid biodegradation with loss of strength.The purpose of the study. Experimental evaluation of bioresorbable Mg-Ca-Zn alloy implants in vitro and in bone tissue in vivo, in order to determine the optimal rate of biodegradation, biocompatibility and reparative response of bone tissue.Materials and methods. Samples from the obtained Mg-Ca-Zn alloy were coated in a microarc oxidation bath (MDO), and to further determine the optimal phase composition and surface properties, the samples were kept in an electrolyte. The biodegradation of implants was assessed by the loss of mass of samples in vitro, and the release of gas into bone tissue in vivo, and the biocompatibility and reparative response of bone tissue density.Results. All Mg-Ca-Zn coated samples show reduced weight loss compared to the uncoated sample. Magnesium samples with a 20-minute exposure in electrolyte, in the context of its application in anatomically unloaded areas, showed the optimal rate of biodegradation, biocompatibility and reparative response of bone tissue.Discussion. In our study using the microarc oxidation for control the corrosion resistance samples of magnesium alloy shows good biocompatibility and low corrosion rate. We found 5-fold increase in corrosion resistance in coated implants, compared with uncoated samples.Сonclusion. The results of an experimental evaluation of bioresorbable Mg-Ca-Zn alloy implants in vitro and in bone tissue in vivo showed that Mg-Ca-Zn coated samples demonstrate low weight loss during biodegradation, with minimal gas release into the bone.

A Multifunctional Metal-Phenolic Nanocoating on Bone Implants for Enhanced Osseointegration via Early Immunomodulation.

Surface modification is an important approach to improve osseointegration of the endosseous implants, however it is still desirable to develop a facile yet efficient coating strategy. Herein, a metal-phenolic network (MPN) is proposed as a multifunctional nanocoating on titanium (Ti) implants for enhanced osseointegration through early immunomodulation. With tannic acid (TA) and Sr2+ self-assembled on Ti substrates, the MPN coatings provided a bioactive interface, which can facilitate the initial adhesion and recruitment of bone marrow mesenchymal stem cells (BMSCs) and polarize macrophage toward M2 phenotype. Furthermore, the TA-Sr coatings accelerated the osteogenic differentiation of BMSCs. In vivo evaluations further confirmed the enhanced osseointegration of TA-Sr modified implants via generating a favorable osteoimmune microenvironment. In general, these results suggest that TA-Sr MPN nanocoating is a promising strategy for achieving better and faster osseointegration of bone implants, which can be easily utilized in future clinical applications.

Electrical Impedance Spectroscopy as a Potential Tool for Detecting Bone Porosity

Electrical measurements of bovine trabecular bone samples revealed a perfect correlation between the electrical and mechanical properties. Electrical parameters have surpassed Broadband Ultrasound Attenuation measurements to predict the mechanical properties of bovine bones. There is a linear relationship between dielectric permittivity and bone mineral density. Studies utilizing electrical impedance spectroscopy to evaluate bone include the characterization and monitoring of titanium bone implants, the characterization of bone tissue, and the monitoring of bone fracture healing progress after osteosynthesis. These studies demonstrate that impedance spectroscopy has outstanding potential for assessing bone quality. This study proposes electrical impedance as a method for characterizing bone porosity. Using the DAQ Analog Discovery as an EIS, two electrodes were utilized to determine bone porosity. The procedures include the EIS scanning process and the analysis of its electrical components using the CPE(RC) circuit model. Five bovine samples were used to demonstrate that the EIS spectrum method can be used to determine bone porosity with a reasonable correlation between the parameters R (R2=0.987, F(1,3)=68.067, p<0.004). and C (R2=0.994, F(1,3)=94.041, p<0.002). While the parameter Q (R2=0.922, F(1,3)=22.568, p<0.018) of CPE can indicate the condition of the bovine cancellous bone scaffold surface.

Effects of selective laser melting process parameters on 3D-printing of Ti6Al4V/ST316L composite material and their optimization using response surface methodology

The mechanical properties of Ti6Al4V and ST316L bone implants make them superior to natural bone, which results in fewer contact points with the bone. Different manufacturing processes, such as selective laser melting (SLM), may result in different mechanical properties between Ti-6Al-4V and ST316L implants. Sustainable development for the composite implants was optimized (SLM) in this study to minimize their compressive strength and Young's modulus. A three-dimensional printing process using SLM was optimized based on laser power, hatch distance, laser velocity, and ST316L weight percentage. Composite implants made from titanium alloys and steel alloys were evaluated using response surface methodology (RSM). ST316L composition has been found to influence the mechanical properties of composites in a significant manner, based on the results of parameter optimization. Using Ti6Al4V/ST316L as a biomaterial in knee joint prostheses is possible.

Enhanced osteogenic response by collagen type I coating on surface-modified titanium bone implants

Surface modifications of titanium (Ti) bone implants can activate an osteogenic response and accelerate osseointegration after implantation. In this study, in vitro tests were performed to evaluate different titanium dioxide TiO2 modified surfaces, sandblasted, large grit, acid-etched implant surfaces and surfaces featuring nanotubular structures (nanopore diameters of 20 and 100 nm) produced through potentiostatic anodization before and after subjecting them to covalent treatment for functionalization and subsequent coating with collagen type I (Col I). The physicochemical and morphological properties were evaluated using spectroscopy and microscopy, which confirmed the structural and biochemical modifications of the surfaces after coating with Col I. Studies with pre-osteoblastic MC3T3-E1 cells indicate improved cell adhesion and proliferation on surfaces coated with Col I, whereas cell viability remained similar for all evaluated surfaces. The results of alkaline phosphatase expression and activity, as well as a mineralization assay, demonstrated that surfaces coated with Col I acted positively on the osteogenic differentiation of the cells in comparison with the non-coated surfaces. Our findings suggest that, regardless of the previous modification of the TiO2 surface, the addition of a Col I coating presents a promising modification for bone implant applications.

A short review on the effect of mechanical vibration in the evaluation and replacement of bone cement-anchored implants in human bone

Mechanical vibration can be defined as the regular or irregular repetitive movement that makes the body leave its resting state. Mechanical vibrations have an important role in keeping the bones and joints healthy. This review study aimed to investigate the effect of mechanical vibration in the evaluation and replacement of bone cement-anchored implants in human bone. The empirical studies related to mechanical vibrations and bone cement-anchored implants were reviewed. The combinations used to search for studies related to the topic included mechanical vibrations, evaluation, replacement, bone, cement-anchored implants, and human bone. The reviewed studies show that mechanical vibration, either local or whole-body, promotes bone growth in and around the implant. The stimulation of bone growth is important for the strength and durability of cement-anchored bone implants. Through the reviewed studies, it was concluded that local or whole-body mechanical vibration improves the stability and durability of bone and bone implants. Mechanical vibration achieves this effect by increasing bone formation in and around the implants and by improving the contact between the implant and the bone.

Material Selection for Artificial Femur Bone Using PROMETHEE-GAIA Method

Abstract When replacing bones and implants, choosing the right materials for the artificial bone and orthopedic implants is crucial to the procedure’s success. In this work, a thorough assessment of the literature was followed by a thorough and rigorous evaluation of prospective materials for prosthetic femurs using a multicriteria decision-making process known as PROMETHEE-GAIA (Preference Ranking Organization METHod for Enrichment Evaluation and Geometric Analysis for Interactive Assistance). The proposed approach was validated using a total of 12 assessment parameters, including density, tensile strength, and ultimate tensile strength, and 17 candidate materials. The significance of the chosen criteria is well described. These 17 candidate implant materials and the 12 assessment criteria were used to develop a choice matrix. Rankings over the prepared matrix were produced using the PROMETHEE-GAIA program. Ti-6Al-7Nb, Ti-6Al-4V, and ASTM F1537, Standard Specification for Wrought Cobalt-28Chromium-6Molybdenum Alloys for Surgical Implants (UNS R31537, UNS R31538, and UNS R31539), Co-Cr-W emerged as the top contenders and were demonstrated as possible materials for effective artificial femur materials because of the assessment. With a large number of pertinent criteria and a wide range of materials, this study offers a framework for the selection of implant materials. It also emphasizes how choosing materials carefully may increase the durability and efficiency of orthopedic implants.

PMMA bone cement with L-arginine/nano fish bone nanocomplex for apatite formation.

Bone cement is one of the materials used in orthopaedics that serves various functions, such as binding bone implants, replacing damaged bones and filling spaces within bones. Various materials have been used to synthesize bone cement, and one promising material for further research is fish bone waste-based bone cement. This study investigates the potential of fish bone waste-based bone cement by incorporating nano fish bone (NFB) and L-arginine (L-Arg) protein into polymethyl methacrylate (PMMA) to examine apatite growth. NFB derived from the Salmo salar fish positively influences osteoblast cell proliferation and differentiation, while L-Arg enhances biocompatibility and antibiotic properties. The NFB/L-Arg combination holds promise in accelerating new bone formation and cell growth, both of which are crucial for fracture healing and bone remodelling. Tensile strength tests reveal the superior performance of BC-PMMA-1-NFB/L-Arg (36.11 MPa) compared with commercial PMMA (32 MPa). Immersion tests with simulated body fluid (SBF) solution for 7 days reveal accelerated apatite layer formation, emphasizing the potential benefits of NFB/L-Arg in bone cement applications.

Parametric Design of Porous Structure and Optimal Porosity Gradient Distribution Based on Root-Shaped Implants.

Porous structures can reduce the elastic modulus of implants, decrease stress shielding, and avoid bone loss in the alveolar bone and aseptic loosening of implants; however, there is a mismatch between yield strength and elastic modulus as well as biocompatibility problems. This study aimed to investigate the parametric design method of porous root-shaped implants to reduce the stress-shielding effect and improve the biocompatibility and long-term stability and effectiveness of the implants. Firstly, the porous structure part was parametrically designed, and the control of porosity gradient distribution was achieved by using the fitting relationship between porosity and bias and the position function of bias. In addition, the optimal distribution law of the porous structure was explored through mechanical and hydrodynamic analyses of the porous structure. Finally, the biomechanical properties were verified using simulated implant-bone tissue interface micromotion values. The results showed that the effects of marginal and central porosity on yield strength were linear, with the elastic modulus decreasing from 18.9 to 10.1 GPa in the range of 20-35% for marginal porosity, with a maximum decrease of 46.6%; the changes in the central porosity had a more consistent effect on the elastic modulus, ranging from 18.9 to 15.3 GPa in the range of 50-90%, with a maximum downward shift of 19%. The central porosity had a more significant effect on permeability, ranging from 1.9 × 10-7 m2 to 4.9 × 10-7 m2 with a maximum enhancement of 61.2%. The analysis showed that the edge structure had a more substantial impact on the mechanical properties. The central structure could increase the permeability more effectively. Hence, the porous structure with reasonable gradient distribution had a better match between mechanical properties and flow properties. The simulated implantation results showed that the porous implant with proper porosity gradient distribution had better biomechanical properties.

A Porous Fluoride-Substituted Bovine-Derived Hydroxyapatite Scaffold Constructed for Applications in Bone Tissue Regeneration.

Hydroxyapatite is widely used in bone implantation because of its similar mineral composition to natural bone, allowing it to serve as a biocompatible osteoconductive support. A bovine-derived hydroxyapatite (BHA) scaffold was developed through an array of defatting and deproteinization procedures. The BHA scaffold was substituted with fluoride ions using a modified sol-gel method to produce a bovine-derived fluorapatite (BFA) scaffold. Fourier-transform infrared spectroscopy and X-ray diffraction analysis showed that fluoride ions were successfully substituted into the BHA lattice. According to energy dispersive X-ray analysis, the main inorganic phases contained calcium and phosphorus with a fluoride ratio of ~1-2 wt%. Scanning electron microscopy presented a natural microporous architecture for the BFA scaffold with pore sizes ranging from ~200-600 μm. The BHA scaffold was chemically stable and showed sustained degradation in simulated-body fluid. Young's modulus and yield strength were superior in the BFA scaffold to BHA. In vitro cell culture studies showed that the BFA was biocompatible, supporting the proliferative growth of Saos-2 osteoblast cells and exhibiting osteoinductive features. This unique technique of producing hydroxyapatite from bovine bone with the intent of producing high performance biomedically targeted materials could be used to improve bone repair.

Spatial Growth Factor Delivery for 3D Bioprinting of Vascularized Bone with Adipose-Derived Stem/Stromal Cells as a Single Cell Source.

Encapsulating multiple growth factors within a scaffold enhances the regenerative capacity of engineered bone grafts through their localization and controls the spatiotemporal release profile. In this study, we bioprinted hybrid bone grafts with an inherent built-in controlled growth factor delivery system, which would contribute to vascularized bone formation using a single stem cell source, human adipose-derived stem/stromal cells (ASCs) in vitro. The strategy was to provide precise control over the ASC-derived osteogenesis and angiogenesis at certain regions of the graft through the activity of spatially positioned microencapsulated BMP-2 and VEGF within the osteogenic and angiogenic bioink during bioprinting. The 3D-bioprinted vascularized bone grafts were cultured in a perfusion bioreactor. Results proved localized expression of osteopontin and CD31 by the ASCs, which was made possible through the localized delivery activity of the built-in delivery system. In conclusion, this approach provided a methodology for generating off-the-shelf constructs for vascularized bone regeneration and has the potential to enable single-step, in situ bioprinting procedures for creating vascularized bone implants when applied to bone defects.

On‐Demand Magnetically‐Activated Drug Delivery from Additively Manufactured Porous Bone Implants to Tackle Antibiotic‐Resistant Infections

AbstractThis study proposes a new concept for an on‐demand drug releasing device intended for integration into additively manufactured (i.e., 3D printed) orthopedic implants. The system comprises a surface with conduits connected to a subsurface reservoir used for storage and on‐demand release of antimicrobial agents, covered with a cap that prevents the antibacterial agents from being released until alternating magnetic field (AMF) raises the temperature of the cap, thus, releasing the stored drug. To demonstrate this concept, Ti6Al4V specimens are directly 3D printed using selective laser melting and their surface, reservoirs, and drug releasing properties are characterized. A new synthetic antimicrobial peptide, SAAP‐148, is thereafter tested for its cytotoxic, osteogenic, and immunomodulatory effects at concentrations relevant for its minimal bactericidal concentration (MBC) and is compared with its natural analogue, LL‐37. The results showed that AMF successfully activated the release from the 3D printed loaded samples. Both peptides demonstrated to be non‐cytotoxic within the MBC levels for macrophages and preosteoblasts and did not influence their osteoimmunomodulatory behavior. The findings of this study indicate that the proposed concept is technically feasible and has the potential to be used for the development of bone implants with on‐demand delivery systems to fight IAI without systemic or continuous local release of antibiotics.

Tuning of Graphene oxide - Hydroxyapatite (GO-HAp) composite for enhanced fluorescence and anti-oxidant properties-green approach

Many researchers are working on doping and co-doping of HAp with metal ions and rare earth elements to improve the applicability of HAp, but all these studies question the biocompatibility of HAp. Further, there are no reports on the fluorescence and anti-oxidant aspects. Graphene oxide being a non-toxic material, with excellent physiochemical properties can enhance and induce new properties in HAp. The present study explored the transformation of sea wastes into valuable products such as HAp reduces the negative impact on the environment. GO (from cellulose) and HAp (from Anadara granosa, Crassostrea virginica, synthetic CaCO3). The prepared composite material from two different methods (Post-modification and In situ) of three different precursors are compared and contrasted. From the PXRD results, P-GO-HAp has retained both GO and HAp phases with high crystallinity. The hydrophilicity and higher calcium ratio in P-GO-HApS, the presence of β – TCP phase after composite formation in P-GO-HApC & P-GO-HApO has improved its utility in bone implants. Also, the intense bluish-green emission of P-GO-HApC & P-GO-HApO paves the way for biocompatible imaging. The interplay of calcium, improved hydrophilicity, and stable radical sites of the conjugated π system of GO paved the way for antioxidant property in P-GO-HApS with a radical scavenging potential of 32.88%. With the increase in antioxidant properties, the composite has enhanced inhibition on the most common dental infection caused by Streptococcus mutans.

Simultaneous Evaluation of Bone Cut and Implant Placement Accuracy in Robotic-Assisted Total Knee Arthroplasty.

Background: This study aimed to evaluate the accuracy of bone cuts and implant placements, simultaneously, for total knee arthroplasty (TKA) performed using a system with an active robotic arm. Methods: Two experienced orthopaedic surgeons performed TKA on ten cadaveric legs. Computed tomography scans were performed to compare the bone cuts and implant placements with the preoperative planning. The differences between the planned and actual bone cuts and implant placements were assessed using positional and angular errors in the three anatomical planes. Additionally, the cut-implant deviations were calculated. Statistical analysis was performed to detect systematic errors in the bone cuts and implant placements and to quantify the correlations between these errors. Results: The root-mean-square (RMS) errors of the bone cuts (with respect to the planning) were between 0.7-1.5 mm and 0.6-1.7°. The RMS implant placement errors (with respect to the planning) varied between 0.6-1.6 mm and 0.4-1.5°, except for the femur and tibia in the sagittal plane (2.9°). Systematic errors in the bone cuts and implant placements were observed, respectively, in three and two degrees of freedom. For cut-implant deviations, the RMS values ranged between 0.3-2.0 mm and 0.6-1.9°. The bone cut and implant placement errors were significantly correlated in eight degrees-of-freedom (ρ ≥ 0.67, p < 0.05). Conclusions: With most of the errors below 2 mm or 2°, this study supported the value of active robotic TKA in achieving accurate bone cuts and implant placements. The findings also highlighted the need for both accurate bone cuts and proper implantation technique to achieve accurate implant placements.

Porous Ti3SiC2 ceramics with improved osteogenic functions via biomineralization as load-bearing bone implants

Ti3SiC2 ceramics exhibit excellent mechanical properties and good biocompatibility, rendering them promising bone substitutes for load-bearing conditions. However, the bone integration and osteogenic ability of Ti3SiC2 ceramics remain unclear. Herein, porous Ti3SiC2 ceramics were prepared and systematically investigated as bone scaffolds. The Ti3SiC2 scaffolds with a porosity of 62.9 % ± 2.5 % showed high compressive strength ∼68.12 ± 4.33 MPa. Silicon hydroxyl groups formed on the surface of Ti3SiC2 after soaking in simulated body fluid, which played a critical role in the apatite mineralization of the scaffolds. Biomineralization of Ti3SiC2 scaffolds was found when implanted subcutaneously in the rat dorsum for 2 weeks, demonstrating good osteogenesis ability. The apatite mineralization of the Ti3SiC2 scaffold facilitated the polarization of RAW264.7 cells from M1 to M2 phenotype, which also promoted the differentiation of MC3T3-E1 cells. The porous Ti3SiC2 scaffolds improved osteointegration and bone regeneration after implantation in rabbit femoral defects. Impressively, the number of the newly formed trabeculae in the Ti3SiC2 group was three times of the control group after implantation for 8 weeks, showing excellent bone defect repair. This work demonstrates that Ti3SiC2 implants with improved biological functions likely via in-situ biomineralization are promising candidates for bone regeneration.

Vitamin D3 Release from MgO Doped 3D Printed TCP Scaffolds for Bone Regeneration.

Regenerating bone tissue in critical-sized craniofacial bone defects remains challenging and requires the implementation of innovative bone implants with early stage osteogenesis and blood vessel formation. Vitamin D3 is incorporated into MgO-doped 3D-printed scaffolds for defect-specific and patient-specific implants in low load-bearing areas. This novel bone implant also promotes early stage osteogenesis and blood vessel development. Our results show that vitamin D3-loaded MgO-doped 3D-printed scaffolds enhance osteoblast cell proliferation 1.3-fold after being cultured for 7 days. Coculture studies on osteoblasts derived from human mesenchymal stem cells (hMSCs) and osteoclasts derived from monocytes show the upregulation of genes related to osteoblastogenesis and the downregulation of RANK-L, which is essential for osteoclastogenesis. Release of vitamin D3 also inhibits osteoclast differentiation by 1.9-fold after a 21-day culture. After 6 weeks, vitamin D3 release from MgO-doped 3D-printed scaffolds enhances the new bone formation, mineralization, and angiogenic potential. The multifunctional 3D-printed scaffolds can improve early stage osteogenesis and blood vessel formation in craniofacial bone defects.

Biodegradation-affected fatigue behavior of extrusion-based additively manufactured porous iron–manganese scaffolds

Additively manufactured (AM) biodegradable porous iron-manganese (FeMn) alloys have recently been developed as promising bone-substituting biomaterials. However, their corrosion fatigue behavior has not yet been studied. Here, we present the first study on the corrosion fatigue behavior of an extrusion-based AM porous Fe35Mn alloy under cyclic loading in air and in the revised simulated body fluid (r-SBF), including the fatigue crack morphology and distribution in the porous structure. We hypothesized that the fatigue behavior of the architected AM Fe35Mn alloy would be strongly affected by the simultaneous biodegradation process. We defined the endurance limit as the maximum stress at which the scaffolds could undergo 3 million loading cycles without failure. The endurance limit of the scaffolds was determined to be 90 % of their yield strength in air, but only 60 % in r-SBF. No notable crack formation in the specimens tested in air was observed even after loading up to 90 % of their yield strength. As for the specimens tested in r-SBF, however, cracks formed in the specimens subjected to loads exceeding 60 % of their yield strength appeared to initiate on the periphery and propagate toward the internal struts. Altogether, the results show that the extrusion-based AM porous Fe35Mn alloy is capable of tolerating up to 60 % of its yield strength for up to 3 million cycles, which corresponds to 1.5 years of use of load-bearing implants subjected to repetitive gait cycles. The fatigue performance of the alloy thus further enhances its potential for trabecular bone substitution subjected to cyclic compressive loading. Statement of significanceFatigue behavior of extrusion-based AM porous Fe35Mn alloy scaffolds in air and revised simulated body fluid was studied. The Fe35Mn alloy scaffolds endured 90 % of their yield strength for up to 3 × 106 loading cycles in air. Moreover, the scaffolds tolerated 3 × 106 loading cycles at 60 % of their yield strength in revised simulated body fluid. The Fe35Mn alloy scaffolds exhibited a capacity of withstanding 1.5-year physiological loading when used as bone implants.

Study of Antimicrobial Activity of ZnO Nanoparticles Dopped Natural Hydroxyapatites

Bone replacements and repairs often encounter infections from diverse microbes, necessitating costly and painful secondary surgeries and treatments. Developing antimicrobial bone implants is crucial to mitigate these complications and enhance regeneration. Moreover, the biological synthesis of hydroxyapatite (Ca10(PO₄)6(OH)2, a primary component of human bone, presents advantages over chemically synthesized alternatives due to lower impurity and cost. This study focuses on synthesizing hydroxyapatite powders from buffalo and goat femoral bones, with the incorporation of ZnO nanoparticles. Analyzed via XRD and FTIR, the prepared powder exhibited potent antimicrobial properties against various bacterial strains. Specifically, the hydroxyapatite powder doped with ZnO nanoparticles displayed superior antimicrobial activity. Consequently, this synthesized material holds significant promise for applications in bone tissue engineering and related fields.