Papers by Keyword: Biocompatibility

Abstract: Background: Knee joint replacement surgery is a widely used procedure for managing severe knee osteoarthritis, rheumatoid arthritis, and traumatic arthritis. The selection of implant materials plays a crucial role in the long-term success of the procedure, influencing biomechanical stability, biocompatibility, and wear resistance. Polyether ether ketone (PEEK), a high-performance thermoplastic polymer, has recently gained attention as a potential alternative to conventional metal and polymer implants due to its closer elastic modulus to human bone, excellent biocompatibility, and radiolucency. However, the intrinsic bio-inertness and wear resistance limitations of PEEK have raised concerns regarding its early osseointegration and long-term durability. Methods: To overcome these challenges, researchers have explored various modifications, including bioactive coatings, composite reinforcement, and porous structuring, to enhance it clinical performance. This review evaluates the current applications of PEEK in knee surgery, comparing its properties with commonly used materials such as ultra-high-molecular-weight polyethylene (UHMWPE), cobalt-chromium (CoCr), and titanium. Results: We analyze its role in procedures such as high tibial osteotomy (HTO) and anterior cruciate ligament reconstruction (ACLR). While PEEK demonstrates promising mechanical and biological advantages, further studies on long-term performance, wear behavior, and improved osseointegration techniques are essential to determine its suitability as a standard implant material in knee surgery. Conclusions: PEEK has the potential to serve as an alternative implant material for knee joint replacement due to its biomechanical compatibility and favorable biological properties. However, addressing its bio-inertness and wear resistance limitations through material modifications remains a key area for future research.

Abstract: PEEK is a thermoplastic polymer widely employed in the orthopedic field for the fabrication of prosthetic devices, owing to its Young’s modulus being comparable to that of cortical human bone. Surface functionalization through biomaterial micropatterning represents an effective strategy to enhance osteointegration. To this end, an innovative vibration-assisted surface embossing process was applied to PEEK samples. The surface patterning was performed using a square punch with a side length of 0.5 [mm], fabricated via CNC milling. The process is enabled by a linear actuator capable of generating controlled vibrations to induce localized sub-Tg heating of the polymer surface. After that, the application of a post-load is required for the embossing stage. This system allows frequency tuning in the range of 1–4 [kHz]. Finally, the patterned surfaces were sonicated through an ultrasound cleaner and characterized through contact angle measurements and white-light interferometry, confirming the feasibility of the process and demonstrating an increase in both the polar component of the surface free energy and the hydrophilicity compared with merely polished specimens. Enhancing the polar component of surface free energy is an effective strategy to improve biomaterial biocompatibility, confirming the relevance of the proposed surface modifications. Slightly hydrophilic surfaces promote preferential osteoblast adhesion and stable cytoskeletal organization, demonstrating the complementary roles of surface topography in shaping cellular responses.

Abstract: Incremental Sheet Forming (ISF) has been widely studied for metallic materials, demonstrating significant potential in flexible and low-cost sheet metal forming (aluminum, magnesium or titanium). Recently, attention has shifted toward polymeric materials due to their growing relevance in medical and customized applications (PCL, UHMWPE, PEEK). However, the availability of commercial sheets is limited to thicknesses, geometries, and material options. In this context, Fused Deposition Modeling (FDM) has emerged as a complementary technique to produce tailored polymeric sheets, enabling the integration of additive manufacturing with ISF processes to overcome limitations in available commercial sheets and expand design flexibility. Considering the success of this hybridization for forming PCL, this work investigates the feasibility of applying Single Point Incremental Forming (SPIF) to PEEK sheets produced via Fused Deposition Modeling (FDM). The study analyzes the influence of printing parameters, forming conditions, and thermal treatment on part quality, porosity, forces, temperature, defects, and fracture behaviour.

Abstract: Manganese is a key transition metal essential to metallurgy, particularly for strengthening steel. Alloys of manganese including iron-manganese (Fe-Mn), manganese-aluminum (Mn-Al), manganese-titanium (Mn-Ti), and other multi-element systems are increasingly critical in biomedical, aerospace, energy, and marine industries. This review consolidates current knowledge, highlights research gaps, and charts future directions by examining Mn’s chemical and metallurgical properties, major alloy systems, mechanical and corrosion performance, and modern processing methods. In-depth case studies in automotive (TWIP steels), biomedical (biodegradable stents), and aerospace (high-entropy alloys) applications are presented to illustrate real-world performance. A comparative analysis of advanced manufacturing techniques, including Laser Powder Bed Fusion (L-PBF) and Directed Energy Deposition (DED), reveals the profound impact of processing on microstructure and properties. Drawing on over seventy recent studies, this work assesses how microstructure, phase transformations, and alloying behavior influence performance across structural, biodegradable, and functional applications. Despite notable progress, challenges persist in predicting corrosion, ensuring long-term biocompatibility, overcoming low-temperature brittleness, and mitigating the environmental impacts of manganese processing. A critical evaluation of the manganese lifecycle, from mining impacts to recycling challenges, underscores the need for sustainable practices. To address these challenges, we recommend advanced manufacturing for precise microstructural control, surface treatments to improve corrosion resistance, and computational modeling to predict performance. Future research should prioritize corrosion-resistant, biocompatible alloys, refine additive manufacturing for complex designs, gather long-term biocompatibility data, and improve recycling methods. Collaborative efforts integrating simulations, experimental validation, and sustainable practices will ultimately shape manganese’s role in future innovations.

Abstract: This study focuses on the development of magnesium-zinc (Mg-Zn) matrix alloys enriched with rare earth elements (RE), aiming to evaluate both their structural characteristics and in vitro biological responses. The designed alloys incorporated varying amounts of Zn, Nd, Ce, Gd, Zr, and Ca. Two specific EZ43 alloy compositions were synthesized using an induction-heated furnace under a protective gas atmosphere, differing in their Nd-to-Ce weight ratios (1:2 and 2:1). Following casting, the alloys were homogenized at 400 °C for 24 hours to eliminate dendritic structures and minimize elemental segregation. X-ray fluorescence (XRF) was employed to assess the chemical compositions, while scanning electron microscopy (SEM) provided detailed insight into microstructural features and potential intermetallic phases. Biocompatibility was evaluated through cytotoxicity and genotoxicity tests, conducted in accordance with internationally recognized standards to ensure reliability. Results indicated no genotoxic effects and demonstrated high cell viability up to 142% particularly in Nd-enriched samples. Statistical analysis revealed significant differences in biological behavior between the Nd-rich and Ce-rich alloys, with Nd contributing positively to cellular responses. These findings emphasize the importance of RE composition in influencing biocompatibility and suggest that Nd-enriched Mg-Zn alloys hold strong promise for biomedical applications requiring both structural integrity and favorable biological interaction.

Abstract: Development of drug eluting biodegradable cardiovascular stent materials offers a promising alternative to conventional bare metallic stents due to their excellent biocompatibility and ability to eliminate long-term complications associated with permanent implants. The study presents a novel drug-eluting bilayer coating comprising inner calcium phosphate (CaP), titanium dioxide (TiO₂) and outer DEX-loaded chitosan for magnesium alloy stents. The coating is engineered to enhance corrosion resistance, promote biocompatibility and provide controlled drug release to mitigate restenosis and inflammation. The synergistic properties of CaP-TiO₂ improve the structural stability of the coating, while the chitosan matrix ensures effective drug delivery. In-vitro corrosion measurements and drug release kinetics demonstrate the coating’s potential for dual-functionality as a biodegradable barrier and a therapeutic agent carrier respectively. The innovative approach highlights a significant step towards the development of biodegradable drug-eluting stents tailored for cardiovascular applications.

Abstract: Ultra-high molecular weight polyethylene (UHMWPE) has been used as a bearing material in total joint replacements due to its excellent mechanical properties and biocompatibility. The acetabular cup in total hip replacement and the tibial component in total knee replacement is widely fabricated from UHMWPE. The use of UHMWPE in total joint replacements is well established, and the goal is to improve its mechanical properties, wear resistance, and oxidation resistance. The quality and life span of the artificial joints can be further increased by enhancing the relevant mechanical properties of UHMWPE. The addition of filler material to UHMWPE is an effective way to enhance its relevant properties. In this study, relevant properties of UHMWPE were enhanced by incorporating an appropriate filler. Reduced Graphene Oxide (rGO) was selected as a filler material as it improves mechanical properties, wear resistance, toughness, and thermal stability. Graphene oxide (GO) was synthesized by Modified Hummer’s Method (MHM), and it was thermally reduced to obtain rGO. The synthesized GO was characterized by Fourier Transform Infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD) which confirmed the accurate synthesis. The reduction of GO was validated by the disappearance of (OH) broad peak in the FTIR analysis. The rGO/UHMWPE nanocomposite was prepared by adding 0.7 wt.% of rGO employing the solvent mixing method. The morphology of the composite was validated by Scanning Electron Microscopy (SEM). Tensile and Izod Impact tests were performed on the samples which showed an increase in tensile strength of 33.2% and the impact strength increased by 140.5%. The rGO/UHMWPE nanocomposite with greater tensile and impact strength is an excellent candidate to produce orthopedic implants with superior properties.

Abstract: Polyetheretherketone (PEEK) as alternate biomaterial to traditional metallic implant materials has become greater important. At the same time have greater chemical resistance, mechanical properties, biocompatibility and radiolucency, making it convenient for use as dental and orthopedic implants. In the present study the biological behavior was evaluated of polymer composites based polyetheretherketone combined with various nano hydroxyapatite and nano titanium dioxide blending up to (1.5 wt%). The bioactivity of the specimens was evaluated by investigation apatite formation after immersion for 7 days and 14 days in simulated body fluid (SBF). XRD and SEM were used to approve the bioactivity of the specimens. Cell viability, proliferation, and the cell attachment activity of L929 mouse fibroblast cells was evaluated after (1, 3 & 5) days by MTT assay. Antibacterial property of the specimens versus S. aureus was observed with optical density methods. The results detected that the apatite-like layer formation was clearly observed on specimens after immersion for different period in simulated body fluid (SBF). Moreover, Results of MTT assay recorded the PEEK specimens excited the activity of fibroblasts and therefore a high cytocompatibility was noticed and specimens showed antibacterial properties against S. aureus.

Abstract: Microbial Fuel Cells (MFCs) are electrochemical devices that exploit microbes for wastewater treatment with simultaneous power production. Concerning reactor design, electrode materials and operation modes, great achievements have been reported with an emphasis on developing anode materials to improve overall MFC performance. Anode materials (carbon cloth, carbon veil, carbon sponges) and their properties such as biocompatibility, electrical conductivity, surface area and efficient transport of waste play a very important role in power generation in MFCs. Despite their low cost, they present structural-based disadvantages eg. Fragility, and low conductivity issues. Additive manufacturing of Fused Deposition Modelling (FDM) due to its tailoring properties, has employed various polymer-based materials such as Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) for manufacturing applications. In addition, carbon-based composites and hybrid materials eg. electrically conductive PLA and ABS have already been fabricated and are commercially available to exploit good electrical conductivity and structural rigidness. In this research, FDM was used to fabricate custom-sized electrodes made of a laboratory-produced electrically conductive ABS filament. A parametric study of conductivity and biocompatibility properties of these electrodes in correlation to 3D printer parameters was investigated and reported. Furthermore, treatment with a combination of thermal, mechanical, and chemical procedures was performed to improve the crucial parameters of anodes for MFCs.

Abstract: Magnesium alloys are suitable biological material because of its favourable mechanical qualities, high biocompatibility, and biodegradability. However, it has poor corrosion resistance and has rapid dissolution in the corrosive environment which will weakens its mechanical characteristics. The surface characteristics of magnesium alloy must thus be changed using a suitable surface modification technology, such as micro arc oxidation (MAO). This article examines recent developments and advancements in biodegradable surface coatings applied to magnesium alloys. It was observed there are four steps of MAO process, the formation of a thinner and denser barrier, commencement of oxides in bare Ca-Mg matrix following the presence of sparks; the horizontal expansion of the oxide layer, and finally thickening of MAO coating. It was observed that characteristics of MAO coating can changed by varying electrical parameters like duty cycle, current density, type of power output, frequency, and processing time. It was noticed that when all other factors are held constant, duty cycle, processing time, and frequency primarily effect the coating's porosity, number of cracks and thickness, which in turn influences how well the coating performs. DC, AC, pulsed bipolar, and pulsed unipolar, are the four categories into which the current regimes are classified. It was found that, unipolar current mode MAO coatings found to be rough, highly porous, and vulnerable to microcracks due to stronger spark discharge. MAO coating produced in a bipolar current type of mode have larger pores but are more uniform in thickness and compact. It was noticed that the in-vitro cell assays showed cells L929 on the Ca-P coated Mg alloy to have considerably good adhesion, a high growth rate, and strong proliferation (p 0.05). In other words, the cytocompatibility was greatly enhanced by the Ca-P coating. It was discovered that the Ca-P coated Mg alloy improved cell responsiveness and encouraged early bone formation at the implant/bone interface by both conventional pathological examination and immunohistochemistry investigation. The Ca-P coating was found to be an effective method for raising the surface bioactivity of Mg alloy. It was also observed that the calcium phosphate coating deposited by MAO process improve surface biomineralization which is the main mechanism behind bioactivity. Functional groups that are present on surface engage electrostatically through calcium and phosphate ions from solutions to start the biomineralization process. Calcium phosphates have excellent biocompatibility and are quite comparable to the mineral makeup of bone. The current study aims to investigate the bioactivity of calcium phosphate coatings and the characteristics of magnesium and its alloys.