The development of multifunctional surfaces on titanium implants is a critical strategy for mitigating post-operative infections and enhancing long-term clinical integration. This study investigates a dual-stage surface modification of the Ti6Al4V alloy, combining shifted Laser Surface Texturing (sLST) with functional ethanol-based silver coatings. The novelty of this research lies in the synergistic combination of advanced sLST surface engineering, which creates a hexagonal "reservoir" topography, and the stable functionalization of these complex structures with antimicrobial silver particles. Initially, the substrates were laser-processed to create a defined hexagonal surface morphology, followed by the deposition of silver-containing) and silver-free coatings via dip-coating and subsequent heat treatment. Comprehensive surface characterization confirmed a homogeneous distribution of silver particles within the porous laser-textured structure, with silver concentrations in the resulting extracts reaching several mg/l. Biological evaluation revealed that the silver-doped coatings achieved nearly 100% antibacterial efficacy against Escherichia coli after 24 hours, showing zero or only negligible colony growth compared to the silver-free and reference samples. Cytotoxicity testing with extracts using L929 fibroblasts demonstrated that all modified surfaces maintained relative metabolic activity above 70% threshold, thus qualifying as non-toxic according to ISO 10993-5 standards. Despite this high metabolic viability, microscopic analysis revealed localized impairments in cell morphology, suggesting a complex cellular response that may be influenced by preparation-related factors. The integration of sLST texturing with Ag-doped ethanol coatings represents a highly effective approach for producing antimicrobial titanium surfaces with maintained cytocompatibility, offering significant potential for advanced orthopaedic and dental applications.

A selection of extruded Mg-Li-Y alloys with varying amounts of the Li and Y alloying elements, considered for temporary orthopedic implant applications, was investigated in terms of their corrosion resistance in a simulated physiological environment and cytocompatibility. The achieved corrosion rates were found to be comparable to other magnesium alloy bioimplant candidate materials, with the best-performing LW24 alloy achieving a very competitive value of 0.77 mm/year. Its resistance to corrosion attack was linked to the high yttrium concentration in the corrosion layer, thereby enhancing its barrier effect. Furthermore, no increased vulnerability to corrosion attack was detected for the dual-phase matrix hcp + bcc LW81 alloy. Both the ISO-standardized test on extracts and direct contact tests verified the cytocompatibility of all the investigated Mg-Li-Y alloys, with the successful colonization of the sample surfaces by the hFOB 1.19 osteoblast cells confirmed by the fluorescence and scanning electron microscopy observations.

Zinc-based alloys are promising candidates for biodegradable implant applications; however, their rapid initial corrosion and limited cytocompatibility remain major challenges. In this study, a Zn-Ca-P layer in a form of parascholzite (CaZn2(PO4)2·2H2O) was prepared on a Zn-0.8Mg-0.2Sr alloy via anodic oxidation followed by short-time biomimetic calcium-phosphate deposition. The formation mechanism, corrosion behaviour, and preliminary biological response of the modified surface were systematically investigated. The Zn-Ca-P layer formed a compact and crystalline phosphate layer that significantly altered the corrosion response of the zinc substrate in Leibovitz L-15 medium containing foetal bovine serum. Electrochemical measurements revealed a pronounced improvement in corrosion resistance and a transition from rapid active dissolution to a controlled, ion-exchange-driven degradation mechanism. The moderate solubility of parascholzite enabled the gradual release of Zn2+ and Ca2+ ions while maintaining surface stability during immersion. Preliminary cell adhesion experiments demonstrated a clear enhancement of cytocompatibility for the Zn-Ca-P-layer-coated samples, where cells readily adhered and spread, in contrast to the bare alloy surface, which showed lower cell attachment. The improved biological response is attributed to the phosphate-rich surface chemistry, favourable surface morphology, and moderated corrosion behaviour. Overall, the parascholzite-like layer provides an effective strategy with which to regulate both corrosion and early cell-material interactions of zinc-based biodegradable alloys, highlighting its potential for temporary biomedical implant applications.

Metal implants used for medical purposes must have physical, chemical and biological properties suitable for their intended use. In order to obtain metal biomaterials with optimised properties, their surfaces are modified. The experimental work consisted of the preparation, characterisation and description of titanium dioxide coatings on commercial titanium. Six types of coatings were synthesised with a sol-gel method, using a basic titania sol with different concentrations and combinations of AgNO3 dopants and bioglass. The sols were applied on a mechanically treated titanium substrate by dip-coating and the coated samples were fired. A basic in vitro bioactivity test was performed under static conditions in a simulated body fluid for 21 days to monitor the formation of bonelike hydroxyapatite. The results confirmed the presence of calcium-and phosphorus-containing precipitates for coatings containing higher concentrations of bioactive glass in combination with silver. The adhesion of the coatings to the substrate was measured by a tape test. The results confirmed the excellent adhesion of all types of the coatings to the substrate. Another measurement examined the antibacterial effects of the coatings against gram-negative Escherichia coli and gram-positive Staphylococcus epidermidis after 4 and 24 hours of interaction. The best results were obtained for coatings containing silver after 24 hours of interaction, which showed a 100 % antibacterial effect in case of both types of the bacteria. The use of both types of dopants may have affected the cytocompatibility of the coatings with the host organism and, therefore, also cytotoxicity tests were performed on the L929 and hFOB 1.19 cell lines. The results of the indirect tests with hFOB 1.19 suggested that neither of the coatings were toxic. In the contact tests with hFOB 1.19, cells were detected on the selected surfaces of the coatings.

The application of sol-gel coatings on titanium-based materials offers a promising approach for enhancing their bioactivity, antibacterial properties, and adhesion, particularly for biomedical applications. This study focuses, for the first time, on the preparation and characterization of sol-gel TiO2-based coatings containing hydroxyapatite and silver in 3D-printed porous gyroid and dodethick structures. TiO2-based coatings on the standard wrought Ti-Al-V alloy rods were used as a reference. The coatings were applied via the specific dip-coating process developed by the author team. The microstructural analysis revealed that the sol-gel coatings on the reference wrought rod samples were homogeneous and well-adhered. The coatings on the porous gyroid and dodethick structures exhibited some localized cracking due to the complex geometry of the porous structures. Bioactivity was evaluated through the standard in vitro simulated body fluid tests, confirming hydroxyapatite precipitation on HA-containing coatings. Antibacterial properties were assessed against Escherichia coli, demonstrating nearly 100 % bacterial inhibition for Ag-containing coatings. Cytotoxicity tests with L929 fibroblast cells indicated that coatings with lower Ag concentrations in sol were non-toxic, while higher Ag concentrations in sol resulted in reduced cell viability, particularly in gyroid structures.

This research focuses on the development of titania coatings containing calcium, phosphorus, and silver, prepared using the sol-gel method and applied via dip-coating technique for use in biomedical implants. These coatings were evaluated for their adhesion, bioactivity, antibacterial properties, and cytocompatibility. The titanium substrates underwent mechanical grinding or blasting with Al2O3 particles, or chemical etching with hydrofluoric acid before coating application. Adhesion was assessed using a tape test, revealing that all coatings adhered well to the substrates. Antibacterial activity against Escherichia coli was evaluated after 4 and 24 hours, demonstrating significant antibacterial effects. Bioactivity was tested in simulated body fluid (SBF) over 20 days, showing promising results. Cytotoxicity was assessed using L929, U-2 OS, and hFOB 1.19 cell lines, confirming the biocompatibility of the coatings. These findings suggest that sol-gel prepared coatings can significantly enhance the functional properties of titanium-based biomaterials for biomedical applications.

In this study, the effect of laser treatment on the surface of 3D-printed TiAl6V4 alloy with triply periodic structures was examined. As-printed and chemically etched samples served as references to assess surface changes. Microscopic analysis confirmed that laser treatment caused remelting and wave-like structures, while rapid cooling led to cracks through the new layer. Chemical and phase analyses showed the presence of TixOy (x = 1–2; y = 1–3) compounds, with variations between untreated and treated samples. Both modification methods removed un-sintered powder, but laser treatment preserved strut thickness, benefiting mechanical properties. In particular, the aim of the surface modification was to eliminate sintered particles to minimize the risk of detachment in in vivo applications, thereby enhancing implant reliability. The best mechanical performance was in untreated samples, with laser-treated ones showing only minor reduction. For example, a diamond-structured sample had a yield strength of 93 ± 2 MPa before treatment and 89 ± 3 MPa after. Additionally, surface hardness increased by about 60

The development of bioabsorbable zinc-based alloys with tailored mechanical properties and biocompatibility holds great promise for advancing medical implant technology. In this study, Zn-Mg and Zn-Mg-Ag alloys were synthesized using mechanical alloying (MA) followed by extrusion to achieve a combination of enhanced strength, ductility, and corrosion resistance. MA for 4 h produced ultrafine-grained powders incorporating Mg2Zn11 intermetallic phases and oxide particles, which contributed to microstructure stabilization during subsequent processing. Extrusion consolidated these powders into dense materials with a uniform grain size of similar to 700 nm, exhibiting ultimate tensile strengths up to 435 MPa and elongation to fracture of similar to 12 %, representing a significant improvement over conventional processing methods. The addition of silver further enhanced the antibacterial properties, demonstrating notable efficacy against Staphylococcus epidermidis, while maintaining non-cytotoxic behavior in vitro. Corrosion rates remained low, with uniform surface degradation and the formation of protective corrosion layers. This work highlights the efficacy of combining powder metallurgy techniques to bioabsorbable zinc-based alloys with exceptional mechanical performance, corrosion behavior and in vitro cytocompatibility, providing a pathway for next-generation biodegradable medical devices.

In vitro testing is the first important step in the development of new biomaterials. The human fetal osteoblast cell line hFOB 1.19 is a very promising cell model; however, there are vast discrepancies in cultivation protocols, especially in the cultivation temperature and the presence of the selection reagent, geneticin (G418). We intended to use hFOB 1.19 for the testing of Zn-based degradable metallic materials. However, the sensitivity of hFOB 1.19 to zinc ions has not yet been studied. Therefore, we compared the toxicity of zinc towards hFOB 1.19 under different conditions and compared it with that of the L929 mouse fibroblast cell line. We also tested the cytotoxicity of three types of Zn-based biomaterials in two types of media. The presence of G418 used as a selection reagent decreased the sensitivity of hFOB 1.19 to Zn2+. hFOB 1.19 cell line was more sensitive to Zn2+ at elevated (restrictive) temperatures. hFOB 1.19 cell line was less sensitive to Zn2+ than L929 cell line (both as ZnCl2 and extracts of alloys). Therefore, the appropriate cultivation conditions of hFOB 1.19 during biomaterial testing should be chosen with caution.

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The objective of this study is to comprehensively investigate the formation mechanism of hopeite on a promising biodegradable Zn-0.8Mg-0.2Sr alloy during its self-corrosion process and its subsequent influence on the interaction of the material with cells and bacteria. Notably, the self-corrosion process of Zn-based alloys inherently generates Zn2+ ions, eliminating the necessity for additional zinc compounds in the treatment. The investigation focused on the chemical composition of the applied baths, exposure time, and temperature, in order to analyze the structure, quality, distribution, phase composition, thickness, and roughness of the resulting layers bringing range of key pros and cons for suggested materials. While the thin layers are considered more beneficial in a wide range of applications, the resulting thinnest layer was observed after exposure to the bath containing additives at 50 degrees C for 24 h, measuring approximately 192 +/- 21 pm in thickness. In addition, the layer possessed the most homogeneous distribution under these conditions. Generally, the layers formed in the bath without additives exhibited higher thickness and rougher surfaces compared to those in the bath containing additives. Such results had a direct impact on dissolution rate, cytotoxicity, and antibacterial properties. The highest dissolution rate (40.7 mg.cm(-2).day(-1)) indicating a limited lifetime of the layer was obtained for material processed under the following coating condition: 50 degrees C, 24 h, and bath without additives. The general presence of surface layers manifested in increased cell viability under direct cytotoxicity test, while smoother surface conditions also supported the antibacterial properties, both making suggested treatments as interesting variations for biodegradable zinc-based materials.

The focus of our study was to observe the simultaneous effects of microbial transglutaminase (MTG) treatment and exopolysaccharides (EPS) on the rheological and microstructural properties of a yoghurt. Transglutaminase was applied to milk before fermentation and simultaneously with a yoghurt culture. Yoghurts were fermented in short-term (42 & DEG;C, 6-8 h) and long-term (30 & DEG;C, 16-18 h) fermentations with a EPS-producing culture that produces EPS and a non-EPS-producing that does not. Treatment with transglutaminase caused an increase in gel strength and viscosity, especially in the case of simultaneous application of MTG and culture. Furthermore, the presence of EPS enhanced these properties. New three-dimensional structures of proteins decreased the size of pores between protein chains, which led to improved water binding properties. Syneresis was further reduced by the presence of EPS. Treatment of yoghurts with MTG decreased the extensive ropiness of EPS yoghurts and contributed to a higher acceptability of the texture. & COPY; 2023 Elsevier Ltd. All rights reserved.

Lilial (also called lysmeral) is a fragrance ingredient presented in many everyday cosmetics and household products. The concentrations of lilial in the final products is rather low. Its maximum concentration in cosmetics was limited and recently, its use in cosmetics products was prohibited in the EU due to the classification as reproductive toxicant. Additionally, according to the European Chemicals Agency, it was under assessment as one of the potential endocrine disruptors, i.e. a substance that may alter the function of the endocrine system and, as a result, cause health problems. Its ability to act as an androgen receptor agonist and the estrogenic and androgenic activity of its metabolites, to the best of our knowledge, have not yet been tested. The aim of this work was to determine the intestinal absorption, cytotoxicity, nephrotoxicity, mutagenicity, activation of cellular stress-related signal pathways and, most importantly, to test the ability to disrupt the endocrine system of lilial and its Phase I metabolites. This was tested using set of in vitro assays including resazurin assay, the CHO/HPRT mutation assay, γH2AX biomarker-based genotoxicity assay, qPCR and in vitro reporter assays based on luminescence of luciferase for estrogen, androgen, NF-κB and NRF2 signalling pathway. It was determined that neither lilial nor its metabolites have a negative effect on cell viability in the concentration range from 1 nM to 100 µM. Using human cell lines HeLa9903 and MDA-kb2, it was verified that this substance did not have agonistic activity towards estrogen or androgen receptor, respectively. Lilial metabolites, generated by incubation with the rat liver S9 fraction, did not show the ability to bind to estrogen or androgen receptors. Neither lilial nor its metabolites showed a nephrotoxic effect on human renal tubular cells (RPTEC/TERT1 line) and at the same time they were unable to activate the NF-κB and NRF2 signalling pathway at a concentration of 50 µM (HEK 293/pGL4.32 or pGL4.37). Neither lilial nor its metabolites showed mutagenic activity in the HPRT gene mutation test in CHO-K1 cells, nor were they able to cause double-strand breaks in DNA (γH2AX biomarker) in CHO-K1 and HeLa cells. In our study, no negative effects of lilial or its in vitro metabolites were observed up to 100 µM using different in vitro tests.

(1) Background: The detection of DNA double-strand breaks in vitro using the phosphorylated histone biomarker (γH2AX) is an increasingly popular method of measuring in vitro genotoxicity, as it is sensitive, specific and suitable for high-throughput analysis. The γH2AX response is either detected by flow cytometry or microscopy, the latter being more accessible. However, authors sparsely publish details, data, and workflows from overall fluorescence intensity quantification, which hinders the reproducibility. (2) Methods: We used valinomycin as a model genotoxin, two cell lines (HeLa and CHO-K1) and a commercial kit for γH2AX immunofluorescence detection. Bioimage analysis was performed using the open-source software ImageJ. Mean fluorescent values were measured using segmented nuclei from the DAPI channel and the results were expressed as the area-scaled relative fold change in γH2AX fluorescence over the control. Cytotoxicity is expressed as the relative area of the nuclei. We present the workflows, data, and scripts on GitHub. (3) Results: The outputs obtained by an introduced method are in accordance with expected results, i.e., valinomycin was genotoxic and cytotoxic to both cell lines used after 24 h of incubation. (4) Conclusions: The overall fluorescence intensity of γH2AX obtained from bioimage analysis appears to be a promising alternative to flow cytometry. Workflow, data, and script sharing are crucial for further improvement of the bioimage analysis methods.

In the field of magnesium-based degradable implantable devices, the Mg-Y-RE-Zr alloying system (WE-type) has gained popularity due to its satisfying degradation rate together with mechanical strength. However, utilization of RE and Zr in the WE-type alloys was originally driven to improve Mg-based alloys for high-temperature applications in the industry, while for medical purposes, there is a question of whether the amount of alloying elements may be further optimized. For this reason, our paper presents the Mg-3Y (W3) magnesium alloy as an alternative to the WE43 alloy. This study shows that the omission of RE and Zr elements did not compromise the corrosion resistance and the degradation rate of the W3 alloy when compared with the WE43 alloy; appropriate biocompatibility was preserved as well. It was shown that the decrease in the mechanical strength caused by the omission of RE and Zr from the WE43 alloy could be compensated for by severe plastic deformation, as achieved in this study, by equal channel angular pressing. Ultrafine-grained W3 alloy exhibited compression yield strength of 362 ± 6 MPa and plastic deformation at maximum stress of 18 ± 1%. Overall, the early results of this study put forward the motion of avoiding RE elements and Zr in magnesium alloy as a suitable material for biodegradable applications and showed that solo alloying of yttrium is sufficient for maintaining desirable properties of the material at once.

In this work, selective laser melting (SLM) technology was used to prepare Mg-4Y-3Nd-Zr (WE43) alloy. This alloy and production method are promising for the design of biodegradable implants. The aim of this study was to investigate the chemical composition, microstructure, mechanical properties, corrosion behavior in simulated body fluid (SBF), and cytotoxicity of the alloy produced by SLM method and to compare it with conventionally gravity cast reference alloy. Analysis of the surface of the revealed an oxygen content of 7 wt.%. Undesirable unmelted and only partially adhered spherical particles of the starting powder were also found. The microstructure of the material was very fine and consisted of α-Mg dendritic matrix, β-Mg41(Nd, Y)5 intermetallic phase, Y2O3 inclusions, and 0.6 vol.% of residual porosity. The Vickers hardness, compressive yield strength, compressive strength, and maximum compressive strain were 88 HV0.1, 201 MPa, 394 MPa, and 14%, respectively, which are close to the reference values in as-cast. The in vitro corrosion rates determined by immersion and potentiodynamic tests were 2.6 mm/year and 1.3 mm/year, respectively. Cytotoxicity tests indicated good biocompatibility of the 3D-printed alloy.

The recent intensive development of the magnesium-based degradation implantable devices showed that the Mg-Y-RE-Zr alloying system (WE-type) provides a satisfying degradation rate together with mechanical strength. However, utilization of both RE and Zr as the alloying elements in the WE-type alloys was originally driven by the industrial demand for magnesium alloys suitable for high-temperature applications. In this study, binary Mg-3Y (W3) and ternary Mg-4Li-4Y (LW44) alloys were investigated as novel biodegradable magnesium alloys. The results showed that omitting RE and Zr did not compromise the degradation rate of W3 alloy when compared to the WE43 alloy and appropriate biocompatibility was preserved as well. Li addition was found to be biocompatible; however, its addition into Mg-Y alloy resulted in pronounced precipitation of Mg24Y5 secondary phase and, consequently, to increased degradation rate. It was shown that the decrease in the mechanical strength caused by omitting RE and Zr from the WE43 alloy can be compensated by severe plastic deformation, in this study by equal channel angular pressing. Ultrafine-grained W3 alloy exhibited compression yield strength of 362(6) MPa and plastic deformation to fracture of 18(1)%. On the other hand, lower mechanical properties were observed in LW44: compression yield strength of 135(9) MPa and plastic deformation to fracture of 16(2)%. Overall, the results of this work unambiguously showed that utilization of RE and Zr is not necessary for the biodegradable applications of magnesium alloys and can be easily avoided, while the desirable properties of the material can be maintained.

The properties of existing biocompatible titanium implants can be improved by controlling the porosity of the substrate or surface modification, e.g., by coating. Two types of titanium substrates were used, made by pressing and the subsequent sintering of titanium powder with and without the pore-forming agent NH4HCO3, and they were compared with a commercial titanium metal sheet. Furthermore, the substrates were coated with a titanium sol enriched with calcium and phosphates using the dip-coating technology. The adhesion and cytotoxic properties were measured on the coatings with standard methods. The adhesion of the coatings to all types of substrates was measured with a tape test and evaluated as very good (5B). The contact and non-contact cytotoxicity tests confirmed that all the substrates with the coatings and without them were non-toxic to a mice fibroblast cell line (L929).

This research work is focused on the investigation of newly developed titania sol-gel coatings containing silver, calcium and phosphate with appropriate abilities to be implanted into the human body. These abilities include adhesion, bioactivity, antibacterial property and cytocompatibility of prepared coatings. Four types of coatings were applied on a titanium substrate by dip-coating technique under different conditions (TCP1, TCP2, TCPA1 and TCPA2). Surfaces of coatings after the firing without silver featured different distribution of circular areas containing Ca. The coatings TCPA1 and TCPA2 were made up of unhomogeneously situated silver. Adhesion of the coatings to the substrates was measured by a tape test. All types of the coatings demonstrated very good adhesion. Isolated cracks that appeared during the firing did not have a negative influence on the adhesion properties. Bioactivity of the coatings was tested in vitro using a simulated body fluid. Three of the four types demonstrated bioactive properties (TCP1, TCP2 and TCPA2), that is, precipitation of crystalline hydroxyapatite as was confirmed by X-ray diffraction. The antibacterial effect (against Escherichia coli and Staphylococcus epidermidis) and cytotoxicity (toward L929 and U-2 OS cell lines, direct and indirect test) were then tested. All the coatings demonstrated very good antibacterial effect against both bacteria after 4- and 24-hr interaction. All the coating types were evaluated as cytocompatible in the indirect test. Cells were able to grow even directly on the coatings.

Nowadays, implants are predominantly made of metallic materials that have two main problems. The first resides in the modulus of elasticity being higher than the one of the human bone (10-20 GPa), resulting in stress shielding and subsequent implant failure. The second problem is the toxicity of some constitution elements of implant materials, which can lead to inflammation of the surrounding tissue due to the release of cytotoxic ions during the corrosion process and, therefore, biodegradability of the implant is not advisable. Hence, recent investigation has focused on the development of metallic materials that are at once biodegradable and biocompatible with the elasticity near human bone. The rate of degradation by corrosion of biocompatible alloys can be controlled by surface improvement or thermal and mechanical treatment. The aim of this work was to prepare the new biodegradable alloy on the base of Mg-Ca-Zn-Mn and study the influence of thermomechanical treatment on the alloy microstructure, phase composition, microhardness and corrosion properties. Homogenization annealing was performed at 480 degrees C for 24 h followed by water quenching. The material was subjected to one pass of equal channel angular pressing (ECAP) at 290 degrees C. The microstructure study was performed for as-cast, heat-treated and ECAPed conditions and was accomplished by microhardness measurement. The chemical and phase composition was observed using of a scanning electron microscope and EDX analysis. To determine the corrosion properties of the alloy, an immersion test was performed together with the measurement of the potentiodynamic polarization.