Search Results (76)

In this study, a biodegradable Mg-Zn-Nd-Gd alloy was processed via multi-directional forging (MDF) to evaluate its microstructural evolution, mechanical performance, and corrosion behavior. Electron backscattered diffraction (EBSD) analysis was conducted to evaluate the influence of grain size and texture on mechanical strength and corrosion resistance. The average grain size decreased significantly from 118 ± 5 μm in the homogenized state to 30 ± 10 μm after six MDF passes, primarily driven by discontinuous dynamic recrystallization (DDRX). Remarkably, this magnesium (Mg) alloy exhibited a rare synergistic enhancement in both strength and ductility, with ultimate tensile strength (UTS) increasing by ~59%, yield strength (YS) by ~90%, while elongation improved by ~44% unlike conventional severe plastic deformation (SPD) techniques that often sacrifice ductility for strength. This improvement is attributed to grain refinement, dispersion strengthening from finely distributed Mg₁₂Nd and Mg₇Zn₃ precipitates, and texture weakening, which facilitated the activation of non-basal slip systems. Despite the mechanical improvements, electrochemical corrosion testing in Hank’s balanced salt solution (HBSS) at 37 °C revealed an increased corrosion rate from 0.1165 mm/yr in homogenized condition to 0.2499 mm/yr (after six passes of MDF. This was due to the higher fraction of low-angle grain boundaries (LAGBs), weak basal texture, and the presence of electrochemically active fine Mg₇Zn₃ particles. However, the corrosion rate remained within the acceptable range for bioresorbable implant applications, indicating a favorable trade-off between mechanical performance and degradation behavior. These findings demonstrate that MDF processing effectively enhances the strength–ductility synergy of Mg-rare earth alloys while maintaining a clinically acceptable degradation rate, thereby presenting a promising route for next-generation biomedical implants. Full article

This work deals with the preparation and characterization of TiAlV/ZnAlCu composite materials. The aim is to create a model for biomaterial with good biocompatibility and acceptable mechanical properties. Infiltrating zinc into the reinforcement made of the titanium alloy could significantly improve the osseointegration of the bioimplant made from this material. The investigated reinforcements of three different geometries made from Ti-6Al-4V prepared by the SLM method (selective laser melting) were infiltrated with molten zinc or the Zn-based alloy. Two infiltration approaches were used—suction of the melt using a vacuum pump and centrifugal casting. By these procedures, different infiltration rates were achieved. Furthermore, the mechanical properties of the prepared composite materials were characterized by compression tests. The results were compared with the mechanical properties of the Ti-6Al-4V alloy reinforcement. Full article

Poly(lactic acid) (PLA) and poly(ether-ether ketone) (PEEK) are widely recognized for their biocompatibility and processability in orthopaedic applications. However, PLA suffers from brittleness and limited thermal and mechanical stability, while PEEK, despite its better strength, does not fully replicate the mechanical and tribological performance of natural bone. This study explores the enhancement of structural and tribological properties in PLA- and PEEK-based composites reinforced with short glass fibres (S-GF) via additive manufacturing. Microstructural analysis confirms uniform GF dispersion within both polymer matrices, with no evidence of agglomeration, fibre pull-out, or interfacial debonding, suggesting strong fibre–matrix adhesion. The incorporation of GF significantly improved mechanical performance: microhardness increased by 38.3% in PLA and 36.3% in PEEK composites, while tensile strength increased by 25.1% and 13.4%, respectively, compared to plain polymers. These enhancements are attributed to effective stress transfer enabled by uniform fibre distribution and strong interfacial bonding. Tribological tests further demonstrate enhanced wear resistance, reduce damage propagation, and improved surface integrity under micro-scratching. These findings highlight the potential of GF-reinforced PLA and PEEK composites as high-performance materials for load-bearing biomedical applications, offering a balanced combination of mechanical strength and wear resistance aligned with the functional requirements of bioimplants. Full article

With an aging population, the number of joint replacement surgeries is on the rise. One of the most common implant materials is cobalt–chromium–molybdenum (CoCrMo) alloy. Hence, the surface properties of this alloy have attracted increasing attention. In this study, nanosecond and femtosecond laser processing, followed by annealing, was employed to modify the CoCrMo surface. The effects of the treatment conditions on the surface morphology, structure, composition, hardness, roughness, contact angle, wear properties, and corrosion current were studied. Femtosecond laser processing with an energy density of 1273 mJ/cm², followed by heat treatment at 160 °C for 2 h, produced laser-induced periodic surface structures (LIPSS) without altering the chemical composition of the alloy and rendered the surface superhydrophobic. In contrast, nanosecond laser treatment at higher laser energy densities promoted the formation of an oxide layer, which improved the hardness and corrosion resistance of the substrate. Overall, the CoCrMo samples processed using the femtosecond laser system exhibited superior corrosion and wear resistance, with a protection efficiency of approximately 92%. Full article

Background and Clinical Significance: Breast reconstruction following mastectomy is a critical aspect of treatment for many patients, offering both physical and psychological benefits. Traditional methods include autologous tissue flaps and implants, with implant-based techniques being the most prevalent in the Western world. However, complications such as capsular contracture remain a concern. Acellular dermal matrices (ADM) have emerged as a valuable alternative, improving outcomes by reducing capsular contracture rates and enhancing tissue integration. Case Presentation: This case report presents the first use of a novel ADM, biocade^® (biotrics bioimplants AG, Berlin, Germany) in breast reconstruction following a mastectomy. A 55-year-old female patient underwent a left-sided nipple-sparing mastectomy, followed by prepectoral direct-to-implant reconstruction using an ADM-wrapped implant. The patient tolerated the procedure well, with no immediate complications observed. Postoperative monitoring focused on wound healing and assessing for signs of complications related to the implant. The use of the ADM resulted into satisfactory aesthetic and functional outcomes. Conclusions: The successful outcome of this case highlights the potential benefits of using collagen matrices in breast reconstruction, particularly in preserving mastectomy scenarios. The immediate results and improved aesthetics offered by prepectoral direct-to-implant reconstruction with ADM align well with patient expectations for a more natural appearance and faster recovery. However, this case report also highlights the need for ongoing research to fully explore the potential of these biomaterials and address associated challenges. Full article

In this work, we present an innovative, crosslinker-free method for preparing chitosan-based hydrogel precursors, fully aligned with green chemistry principles and composed of only five non-toxic, readily available reagents. The key novelty lies in the use of glycerin, which, during thermal annealing, evaporates and triggers a surface or bulk chemical transformation of chitosan, depending on its concentration. This process significantly enhances the material’s mechanical properties after swelling—with up to a 35% increase in tensile strength and a notable reduction in water uptake compared to systems containing AMPS-based crosslinkers. FTIR analysis indicates a partial re-acetylation of chitosan, shifting its structure toward that of chitin, which correlates with improved hydrophobicity (as shown by increased contact angles up to 92°) and greater structural integrity. These improvements are particularly pronounced at glycerin concentrations of 10–20%, whereas higher concentrations (50%) result in brittle, non-moldable films. Importantly, preliminary biological tests confirm that the resulting hydrogels are effectively colonized by mammalian cells, making them promising candidates for bioimplant or tissue engineering applications. Surface morphology and compatibility were further assessed via SEM, AFM, and contact angle measurements. Full article

Zinc has attracted significant attention as a versatile material with potential applications in various fields, particularly in biomedical engineering. Despite its desirable characteristics, such as biodegradability and biocompatibility, the inherently low mechanical strength of zinc has been a major limitation for its broader use in clinical applications. To address this issue and enhance its mechanical performance without compromising its biocompatibility, a novel composite material was developed by mixing zinc oxide (ZnO) with zinc (Zn). ZnO is widely recognized for its high chemical stability, non-toxicity, and antimicrobial properties, making it an excellent additive for biomedical materials. In this study, Zn-ZnO nanocomposites were fabricated by uniformly dispersing ZnO nanoparticles into molten zinc using an ultrasonic processor. The uniform distribution of ZnO nanoparticles within the zinc matrix was confirmed, and the resulting nanocomposites demonstrated remarkable improvements in mechanical properties. Specifically, the hardness and tensile strength of the Zn-ZnO nanocomposites were increased by approximately 90% and 160%, respectively, compared to pure zinc. To evaluate the biodegradation behavior of the materials, both pure zinc and Zn-ZnO nanocomposite samples were immersed in phosphate-buffered saline (PBS) at 37 °C, simulating physiological conditions. The degradation rate was assessed by measuring the weight loss of the material over time. The biodegradation rate of the Zn-ZnO nanocomposites was found to be nearly identical to that of pure zinc under identical conditions, indicating that the addition of ZnO did not adversely affect the degradability of the material. These findings suggest that Zn-ZnO nanocomposites offer a promising solution for biomedical applications by combining improved mechanical properties with maintained biodegradability and biocompatibility. Full article

Introduction: The autoimmune/inflammatory syndrome induced by adjuvants (ASIA) is a rare condition caused by an immune response associated with over-reactivity of the immune system, triggered by adjuvants. The most common adjuvants are aluminium salts but can also be bioimplants or infectious agents. It may lead to the development of various autoimmunologic diseases. Case Report: In the following article, we present the case of a 26-year-old woman who developed SLE likely induced by ASIA syndrome after the aesthetic medicine procedures. The patient was admitted because of arthralgia and fever. She also presented with a butterfly-shaped erythema on her face and erythematous and infiltrative skin lesions on the posterior surface of the thighs and buttocks. We performed numerous diagnostic tests, including laboratory tests, immunological tests, imaging diagnostics such as chest X-ray and USG of the abdomen and joints, and the biopsy of the skin lesion on the left thigh. The results of the diagnostic process led us to diagnose SLE. The patient fulfilled the ACR/EULAR 2019 classification criteria of the SLE. Laboratory results also led to the diagnosis of autoimmune haemolytic anaemia. Due to exposure to numerous adjuvants like tattoo ink, hyaluronic acid, and piercing and the development of the delayed inflammatory reaction (DIR) to hyaluronic acid (HAF), the patient also fulfilled the criteria of ASIA. In the treatment process we applied antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), steroids, hydroxychloroquine, and cyclosporine. The treatment resulted in an improvement in the general condition, resolution of swelling and joint pain, and improvement in skin lesions. Conclusions: ASIA syndrome after bioimplantation is still underdiagnosed, probably due to ignorance or diagnostic difficulties, as symptoms are uncharacteristic and there is no immunological marker for this syndrome. In addition, as in the presented case, it can develop several years after the procedure, and it is difficult for both patient and physician to become aware of the connection. Early diagnosis requires a multidisciplinary approach and may require immunosuppressive treatment in specific cases. Full article

Mandibular bone defect reconstruction remains a significant challenge for surgeons worldwide. Among multiple biodegradable biopolymers, allogeneic bone scaffolds derived from human sources have been used as an alternative to autologous bone grafts, providing optimal conditions for cell recruitment, adhesion, and proliferation and demonstrating significant osteogenic properties. This study aims to investigate the bone microstructure of the human scapula as a source for allogeneic bone scaffold fabrication for mandibular tissue engineering purposes. We created color-coded anatomical maps of the scapula and the mandible, reflecting the best anatomical and geometrical match. In this pilot study, we hypothesized a microstructural similarity of these bone structures and evaluated the human scapula’s bone tissue engineering potential for mandibular bone tissue engineering by focusing on the microstructural characteristics. Lyophilized human scapular and mandibular bioimplants were manufactured and sterilized. Experimental bone samples from the scapula’s acromion, coracoid, and lateral border from the mandibular condyle, mandibular angle, and mental protuberance were harvested and analyzed using micro-CT and quantitative morphometric analysis. This pilot study demonstrates significant microstructural qualitative and quantitative intra-group differences in the scapular and mandibular experimental bone samples harvested from the various anatomical regions. The revealed microstructural similarity of the human scapular and mandibular bone samples, to a certain extent, supports the stated hypothesis and, thus, allows us to suggest the human scapula as an alternative off-the-shelf allogeneic scaffold for mandibular reconstruction and bone tissue engineering applications. Full article

Zirconia ceramics are used in a wide range of applications, including dental restorations, bioimplants, and fuel cells, due to their accessibility, biocompatibility, chemical resistance, and favorable mechanical properties. Following the development of 3D printing technologies, it is possible to rapidly print zirconia-based objects with high precision using stereolithography (SLA) and digital light processing (DLP) techniques. The advantages of these techniques include the ability to print multiple objects simultaneously on the printing platform. To align with the quality standards, it is necessary to focus on optimizing processing factors such as the viscosity of the suspension and particle size, as well as the prevention of particle agglomeration and sedimentation during printing, comprising the choice of a suitable debinding and sintering mode. The presented review provides a detailed overview of the recent trends in preparing routes for zirconium oxide bodies; from preparing the suspension through printing and sintering to characterizing mechanical properties. Additionally, the review offers insight into applications of zirconium-based ceramics. Full article

The optimization of the process of polymer film orientational drawing using the local heater was investigated. One of the problems with this technology is that the strength of the resulting fibers differs significantly from the theoretical estimates. It is assumed that one of the reasons is related to the peculiarity of this technology, when at the point of drawing the film is heated only on one side, which creates a temperature difference between the sides of the film in contact with the heater and the non-contact sides of the film in the air. Estimates show that even a small temperature difference of just 1 °C between these surfaces leads to a significant difference in the rate of plastic deformation of the corresponding near-surface layers. As a consequence, during hardening, in the stretching region, tensile stress is concentrated on the “cold” side of the film, and this effect can presumably lead to the generation of more defects overthere. It has been suggested that defects arising during first stage of hardening, namely, neck formation, can serve as a trigger for the formation of defects such as kink bands on the “cold” side with further orientational strengthening due to plastic deformation of the resulting fibrillar structure, at the boundaries of which microcracks are formed, leading to rupture of the oriented sample. The numerical calculation of heat propagation due to heat conduction in the film from the local surface of the heater is carried out and the temperature distribution along the thickness and width of the film during drawing is found. The temperature difference in the heated layer of the film between the contact and non-contact sides with the heater was calculated depending on the thickness of the film and the speed of its movement along the heater. It was found that the most homogeneous temperature distribution over the film thickness, which is required, by default, for the synchronous transformation of the unoriented initial folded lamellar structure into a fibrillar structure, is observed only for films with a thickness of less than 50 μm. The calculation allows us to scientifically justify the choice of orientation drawing speed and optimal thickness of the oriented polymer film, which is extremely important, for example, for obtaining super-strong and high-modulus UHMWPE filaments used in products for various purposes: from body armor to sports equipment and bioimplants, Full article

The current paper highlights the active development of tissue engineering in the field of the biofabrication of living tissue analogues through 3D-bioprinting technology. The implementation of the latter is impossible without important products such as bioinks and their basic components, namely, hydrogels. In this regard, tissue engineers are searching for biomaterials to produce hydrogels with specified properties both in terms of their physical, mechanical and chemical properties and in terms of local biological effects following implantation into an organism. One of such effects is the provision of the optimal conditions for physiological reparative regeneration by the structural components that form the basis of the biomaterial. Therefore, qualitative assessment of the composition of the protein component of a biomaterial is a significant task in tissue engineering and bioprinting. It is important for predicting the behaviour of printed constructs in terms of their gradual resorption followed by tissue regeneration due to the formation of a new extracellular matrix. One of the most promising natural biomaterials with significant potential in the production of hydrogels and the bioinks based on them is the polymer collagen of allogeneic origin, which plays an important role in maintaining the structural and biological integrity of the extracellular matrix, as well as in the morphogenesis and cellular metabolism of tissues, giving them the required mechanical and biochemical properties. In tissue engineering, collagen is widely used as a basic biomaterial because of its availability, biocompatibility and facile combination with other materials. This manuscript presents the main results of a mass spectrometry analysis (proteomic assay) of the lyophilized hydrogel produced from the registered Lyoplast^® bioimplant (allogeneic human bone tissue), which is promising in the field of biotechnology. Proteomic assays of the investigated lyophilized hydrogel sample showed the presence of structural proteins (six major collagen fibers of types I, II, IV, IX, XXVII, XXVIII were identified), extracellular matrix proteins, and mRNA-stabilizing proteins, which participate in the regulation of transcription, as well as inducer proteins that mediate the activation of regeneration, including the level of circadian rhythm. The research results offer a new perspective and indicate the significant potential of the lyophilized hydrogels as an effective alternative to synthetic and xenogeneic materials in regenerative medicine, particularly in the field of biotechnology, acting as a matrix and cell-containing component of bioinks for 3D bioprinting. Full article

Reducing the impact of some biological fluids on bioimplants involves the control of surface characteristics by modeling the interface architecture and assembling ecofriendly thin films to retard corrosion. Therefore, a mixture of hydrolyzed keratin peptides (HKER) was investigated as a corrosion inhibitor for 304L stainless steel (SS) in physiological serum (PS), using electrochemical measurements associated with optical microscopy and atomic force microscopy (AFM). The tests, performed for various concentrations of the inhibitor at different temperatures, showed that the inhibition efficiency (IE) decreased with a rise in temperature and proportionally increased with the HKER concentration, reaching its maximum level, around 88%, at 25 °C, with a concentration of 40 g L⁻¹ HKER in physiological serum. The experimental data best fitted the El-Awady adsorption model. The activation parameters (E_a, ${∆H}_a$ and ${∆S}_a$) and the adsorption ones (${∆G}_{ads}^0$, ${∆H}_{ads},$ ${∆S}_{ads}$) have highlighted a mixed action mechanism of HKER, revealing that physisorption prevails over chemisorption. AFM parameters, such as the average roughness (R_a), root-mean-square roughness (R_q) and maximum peak-to-valley height (R_p−v), confirmed HKER adsorption, indicating that a smoother surface of the 304L stainless steel was obtained when immersed in a PS-containing inhibitor, compared to the surface designed in blank solution, due to the development of a protective layer on the alloy surface. Full article

Titanium-rich metastable medium-entropy alloys, designed for low elastic moduli, sacrifice strength. However, enhancing their mechanical strength is crucial for bio-implant applications. This study aims to enhance the mechanical properties and corrosion resistance of a metastable Ti₈₀–Nb₁₀–Mo₅–Sn₅ medium-entropy alloy using various treatments, including cold rolling (at 50% and 75% reduction) and precipitation hardening (at room temperature, 150 °C, 350 °C, 550 °C, and 750 °C). The results showed that the alloy underwent a stress-induced martensitic transformation during the rolling process. Notably, the α phase was precipitated in the β grain boundaries after 30 days of precipitation hardening at room temperature. The yield strengths of the alloy increased by 51% and 281.9% after room-temperature precipitation and 75% cold rolling, respectively. In potentiodynamic corrosion tests conducted in phosphate-buffered saline solution, the pitting potentials of the alloy treated using various conditions were higher than 1.8 V, and no pitting holes were observed on the surface of the alloys. The surface oxide layer of the alloy was primarily composed of TiO₂, Nb₂O₅, MoO₃, and SnO₂, contributing to the alloy’s exceptional corrosion and pitting resistance. The 75% rolled Ti₈₀–Nb₁₀–Mo₅–Sn₅ demonstrates exceptional mechanical properties and high corrosion resistance, positioning it as a promising bio-implant candidate. Full article

Pure titanium is gaining increasing interest due to its potential use in dental and orthopedic applications. Due to its relatively weak mechanical parameters, a limited number of components manufactured from pure titanium are available on the market. In order to improve the mechanical parameters of pure titanium, manufacturers use alloys containing cytotoxic vanadium and aluminum. This paper presents unique explosive hardening technology that can be used to strengthen pure titanium parameters. The analysis confirms that explosive induced α-ω martensitic transformation and crystallographic anisotropy occurred due to the explosive pressure. The mechanical properties related to residual stresses are very nonuniform. The corrosion properties of the explosive hardened pure titanium test do not change significantly compared to nonhardened titanium. The biocompatibility of all the analyzed samples was confirmed in several tests. The morphology of bone cells does not depend on the titanium surface phase composition and crystallographic orientation. Full article