Search Results (56)

In this study, 3D Mg scaffolds were obtained by the spark plasma sintering (SPS), and a calcium phosphate coating was then obtained on the samples by the plasma electrolytic oxidation. A hybrid coating with vancomycin, zoledronic acid, and menaquinone MK-7 was formed to improve biocompatibility. The mechanical properties of the formed specimens were studied. According to XRD, XRF, SEM, EDS, and OSP studies obtained scaffolds have developed morphology and contain hydroxyapatite as well as bioactive substances. Formation of coatings improves the wettability of samples (contact angle decreases from 123.8 ± 3.1° to 26.9 ± 4.1°) and increases the surface roughness by more than 3 times. This makes them promising for use as a new generation of implantation materials. The results are important for the development of personalized implants with improved functional characteristics. Full article

The growing antimicrobial resistance and the increasing environmental concerns associated with conventional antibacterial agents have prompted a search for more effective and sustainable alternatives. Biopolymer-based nanofibers are promising candidates to produce environment-friendly antibacterial coatings, owing to their high surface-to-volume ratio, structural adaptability, and tunable porosity. These features make them particularly well-suited for delivering antimicrobial agents in a controlled manner and for physically modifying the surface of medical devices. This review critically explores recent advances in the use of electrospun fibers enhanced with natural antimicrobial agents as eco-friendly surface coatings. The mechanisms of antibacterial action, key factors affecting their efficacy, and comparisons with conventional antibacterial agents are discussed herein. Emphasis is placed on the role of a “green electrospinning” process, which utilizes bio-based materials and nontoxic solvents, to enable coatings able to better combat antibiotic-resistant pathogens. Applications in various clinical settings, including implants, wound dressings, surgical textiles, and urinary devices, are explored. Finally, the environmental benefits and prospects for the scalability and sustainability of green coatings are discussed to underscore their relevance to next-generation, sustainable solutions in healthcare. Full article

Musculoskeletal tissue injuries of the bone, cartilage, ligaments, tendons, and skeletal muscles are among the most common injuries experienced in medicine and become increasingly problematic in cases of significant tissue damage, such as nonunion bone defects and volumetric muscle loss. Current gold standard treatment options for musculoskeletal injuries, although effective, have limited capability to fully restore native tissue structure and function. To overcome this challenge, three-dimensional (3D) printing techniques have emerged as promising therapeutic options for tissue regeneration. Melt electrowriting (MEW), a recently developed advanced 3D printing technique, has gained significant traction in the field of tissue regeneration because of its ability to fabricate complex customizable scaffolds via high-precision microfiber deposition. The tailorability at microscale levels offered by MEW allows for enhanced recapitulation of the tissue microenvironment. Here, we survey the recent contributions of MEW in advancing musculoskeletal tissue engineering. More specifically, we briefly discuss the principles and technical aspects of MEW, provide an overview of current printers on the market, review in-depth the latest biomedical applications in musculoskeletal tissue regeneration, and, lastly, examine the limitations of MEW and offer future perspectives. Full article

This study aimed to evaluate the effect of pixel offset adjustments in digital light processing (DLP) three-dimensional (3D) printing on the marginal and internal fit and surface trueness of zirconia crowns. Zirconia crowns were designed using dental computer-aided design software (Dentbird; Imagoworks) and fabricated with a vat photopolymerization DLP 3D printer (TD6+; 3D Controls) under three pixel offset conditions (−1, 0, and 1). Pixel offset refers to the controlled modification of the outermost pixels in the XY plane during printing to compensate for potential dimensional inaccuracies. The marginal and internal fit was assessed using a triple-scan protocol and quantified using root mean square (RMS) values. Surface trueness was evaluated by measuring RMS, positive and negative errors between the designed and fabricated crowns. Statistical analyses included one-way ANOVA and Pearson correlation analysis (α = 0.05). The Pixel offset had a significant effect on fit accuracy and surface trueness (p < 0.05). Higher pixel offsets increased marginal discrepancies (p = 0.004), with the marginal gap exceeding 120 µm at a pixel offset of 1 (114.5 ± 14.6 µm), while a pixel offset of −1 (85.5 ± 18.6 µm) remained within acceptable limits (p = 0.003). Surface trueness worsened with increasing pixel offset, showing greater positive errors (p < 0.001). Optimizing pixel offset in DLP 3D printing is crucial to ensuring clinically acceptable zirconia crowns. Improper settings may increase marginal discrepancies and surface errors, compromising restoration accuracy. Full article

The global increase in osteomuscular diseases, particularly bone defects and fractures, has driven the growing demand for metallic implants. Additive manufacturing (AM) has emerged as a transformative technology for producing high-precision metallic biomaterials with customized properties, offering significant advantages over traditional manufacturing methods. The integration of machine learning (ML) with AM has shown great promise in optimizing the fabrication process, enhancing material performance, and predicting long-term behavior, particularly in the development of orthopedic implants and vascular stents. This review explores the application of ML in AM of metallic biomaterials, focusing on four key areas: (1) component design, where ML guides the optimization of multi-component alloys for improved mechanical and biological properties; (2) structural design, enabling the creation of intricate porous architectures tailored to specific functional requirements; (3) process control, facilitating real-time monitoring and adjustment of manufacturing parameters; and (4) parameter optimization, which reduces costs and enhances production efficiency. This review offers a comprehensive overview of four key aspects, presenting relevant research and providing an in-depth analysis of the current state of ML-guided AM techniques for metallic biomaterials. It enables readers to gain a thorough understanding of the latest advancements in this field. Additionally, the this review addresses the challenges in predicting in vivo performance, particularly degradation behavior, and how ML models can assist in bridging the gap between in vitro tests and clinical outcomes. The integration of ML in AM holds great potential to accelerate the design and production of advanced metallic biomaterials. Full article

Hydrogel network structures play a crucial role in determining mechanical properties and have broad applications in biomedical and industrial fields. Therefore, their rational design is essential. Herein, we developed a Schiff base-crosslinked hydrogel through the reaction of Tetra-armed polyethylene glycol with aldehyde end groups (Tetra-PEG-CHO) and bovine serum albumin (BSA) under alkaline conditions. In addition, the Tetra-PEG-BSA hydrogel showed a rapid gelation time of around 11 s, much faster than that of the GLU-BSA, HT-BSA, and GDL-BSA hydrogels. It had high optical transmittance (92.92% at 600 nm) and swelling ratios superior to the other gels in different solutions, maintaining structural integrity even in denaturing environments such as guanidine hydrochloride and SDS. Mechanical tests showed superior strain at break (84.12 ± 0.76%), rupture stress (28.64 ± 1.21 kPa), and energy dissipation ability (468.0 ± 34.9 kJ·m⁻³), surpassing all control group hydrogels. MTT cytotoxicity assays indicated that cell viability remained >80% at lower concentrations, confirming excellent biocompatibility. These findings suggest that Tetra-PEG-BSA hydrogels may serve as effective materials for drug delivery, tissue engineering, and 3D printing. Full article

Three-dimensional (3D)-printing technology is revolutionizing orthopedic oncology by providing precise, customized solutions for complex bone defects following tumor resection. Traditional modular endoprostheses are prone to complications such as fretting corrosion and implant failure, underscoring the need for innovative approaches. This case series reports on three patients treated with 3D-printed, patient-specific prostheses and cutting guides. Preoperative CT and MRI data were used to design implants tailored to each patient’s anatomy, manufactured using electron beam melting technology with a titanium–aluminum–vanadium alloy. Functional outcomes showed significant improvements: in Case I, AOFAS improved from 71 to 96, and VAS decreased from 6 to 1; in Case II, AOFAS increased from 65 to 79, and VAS decreased from 5 to 3. Radiographic evaluations demonstrated stable prosthesis placement and early evidence of bone integration in Cases I and II, while in Case III, localized disease control was achieved before systemic progression. This case series highlights the transformative potential of 3D-printed prostheses in addressing the challenges of reconstructing anatomically complex defects. By enabling precise tumor resection and improving functional outcomes, this approach can advance current practices in orthopedic oncology. Further research should explore larger cohorts and use cost-effectiveness analyses to validate these findings and facilitate broader clinical adoption. Full article

This study compares the mechanical properties of 5-mol% yttria partially stabilized zirconia (5Y-PSZ) materials, designed for 3D printing or milling. Three 5Y-PSZ materials were investigated: printed zirconia (PZ) and two milled zirconia materials, VITA-YZ-XT (MZ-1) and Cercon xt (MZ-2). PZ samples were made from a novel ceramic suspension via digital light processing and divided into three subgroups: PZ-HN-ZD (horizontal nesting, printed with Zipro-D Dental), PZ-VN-Z (vertical nesting, printed with Zipro-D Dental) and PZ-VN-Z (vertical nesting, printed with Zipro Dental). Key outcomes included biaxial flexural strength (ISO 6872) and Vickers hardness (n ≥ 23 samples/subgroup). Microstructure and grain size were analyzed using light and scanning electron microscopy. Printed specimens exhibited biaxial flexural strengths of 1059 ± 178 MPa (PZ-HN-ZD), 797 ± 135 MPa (PZ-VN-ZD), and 793 ± 75 MPa (PZ-VN-Z). Milled samples showed strengths of 745 ± 96 MPa (MZ-1) and 928 ± 87 MPa (MZ-2). Significant differences (α = 0.05) were observed, except between vertically printed groups and MZ-1. Vickers hardness was highest for PZ-VN-Z (HV0.5 = 1590 ± 24), followed by MZ-1 (HV0.5 = 1577 ± 9) and MZ-2 (HV0.5 = 1524 ± 4), with significant differences, except between PZ and MZ-1. PZ samples had the smallest grain size (0.744 ± 0.024 µm) compared to MZ-1 (0.820 ± 0.042 µm) and MZ-2 (1.023 ± 0.081 µm). All materials met ISO 6872 standards for crowns and three-unit prostheses in posterior regions. Full article

Hepatitis C virus (HCV) is a major public health concern, and the development of an effective HCV vaccine plays an important role in the effort to prevent new infections. Supramolecular co-assembly and co-presentation of the HCV envelope E1E2 heterodimer complex and core protein presents an attractive vaccine design strategy for achieving effective humoral and cellular immunity. With this objective, the two antigens were non-covalently assembled with an immunostimulant (TLR 7/8 agonist) into virus-mimicking polymer nanocomplexes (VMPNs) using a biodegradable synthetic polyphosphazene delivery vehicle. The resulting assemblies were characterized using dynamic light scattering and asymmetric flow field-flow fractionation methods and directly visualized in their vitrified state by cryogenic electron microscopy. The in vivo superiority of VMPNs over the individual components and an Alum-formulated vaccine manifests in higher neutralizing antibody titers, the promotion of a balanced IgG response, and the induction of a cellular immunity—CD4+ T cell responses to core proteins. The aqueous-based spontaneous co-assembly of antigens and immunopotentiating molecules enabled by a synthetic biodegradable carrier offers a simple and effective pathway to the development of polymer-based supramolecular nanovaccine systems. Full article

Magnesium alloys are promising biomaterials to be used as temporary implants due to their biocompatibility and biodegradability. The main limitation in the use of these alloys is their rapid biodegradation. Moreover, the risk of microbial infections, often following the implant surgery and hard to eradicate, is another challenge. Thus, with the aim of reducing biodegradability and conferring antibiofilm activity, sheets of the magnesium alloy AZ31 were properly modified with the introduction of hydroxy (polyethyleneoxy)propyl silane (PEG) and quaternary ammonium silane chains (QAS). The derivatized sheets were characterized by ATR-FTIR spectroscopy and their performances as concerns their stability, Mg²⁺ in vitro release, and in vitro bioactivity were evaluated as well. The results showed an increased stability with a reduction in corrosion, a slower Mg²⁺ ion release, and the formation of hydroxyapatite in the sheets’ surface. In addition, cytotoxicity evaluations were carried out on human gingival fibroblasts showing that the AZ31 and AZ31-PEG plates had good cytocompatibility. Finally, the antibiofilm activity on Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa was carried out by evaluating the capacity of inhibition of biofilm adhesion and formation. The results demonstrated a significant reduction in biofilm formation by Staphylococcus epidermidis on AZ31-QAS. Full article

Polymeric materials made from renewable sources that can biodegrade in the environment are attracting considerable attention as substitutes for petroleum-based polymers in many fields, including additive manufacturing and, in particular, Fused Deposition Modelling (FDM). Among the others, poly(hydroxyalkanoates) (PHAs) hold significant potential as candidates for FDM since they meet the sustainability and biodegradability standards mentioned above. However, the most utilised PHA, consisting of the poly(hydroxybutyrate) (PHB) homopolymer, has a high degree of crystallinity and low thermal stability near the melting point. As a result, its application in FDM has not yet attained mainstream adoption. Introducing a monomer with higher excluded volume, such as hydroxyvalerate, in the PHB primary structure, as in poly(hydroxybutyrate-co-valerate) (PHBV) copolymers, reduces the degree of crystallinity and the melting temperature, hence improving the PHA printability. Blending amorphous poly(lactic acid) (PLA) with PHBV enhances further PHA printability via FDM. In this work, we investigated the printability of two blends characterised by different PLA and PHBV weight ratios (25:75 and 50:50), revealing the close connection between blend microstructures, melt rheology and 3D printability. For instance, the relaxation time associated with die swelling upon extrusion determines the diameter of the extruded filament, while the viscoelastic properties the range of extrusion speed available. Through thoroughly screening printing parameters such as deposition speed, nozzle diameter, flow percentage and deposition platform temperature, we determined the optimal printing conditions for the two PLA/PHBV blends. It turned out that the blend with a 50:50 weight ratio could be printed faster and with higher accuracy. Such a conclusion was validated by replicating with remarkable fidelity high-complexity objects, such as a patient’s cancer-affected iliac crest model. Full article

Since the discovery that exosomes can exchange genes, their potential use as tools for tissue regeneration, disease diagnosis, and therapeutic applications has drawn significant attention. Emerging three-dimensional (3D) printing technologies, such as bioprinting, which allows the printing of cells, proteins, DNA, and other biological materials, have demonstrated the potential to create complex body tissues or personalized 3D models. The use of 3D spheroids in bioprinting facilitates volumetric tissue reconstruction and accelerates tissue regeneration via exosome secretion. In this review, we discussed a convergence approach between two promising technologies for bioprinting and exosomes in regenerative medicine. Among the various 3D cell culture methods used for exosome production, we focused on spheroids, which are suitable for mass production by bioprinting. We then summarized the research results on cases of bioprinting applications using the spheroids and exosomes produced. If a large number of spheroids can be supplied through bioprinting, the spheroid-exosome-based bioprinting technology will provide new possibilities for application in tissue regeneration, disease diagnosis, and treatment. Full article

Combined 3D cell culture in vitro assays with microenvironment-mimicking systems are effective for cell-based screening tests of drug and chemical toxicity. Filamentous bacteriophages have diverse applications in material science, drug delivery, tissue engineering, energy, and biosensor development. Specifically, genetically modified bacteriophages have the potential to deliver therapeutic molecules or genes to targeted tumor tissues. The engineered bacteriophages in this study significantly enhanced endothelial cell migration and tube formation within the extracellular matrix (ECM). Compared to TGF-β1 alone and non-modified phages, the presence of TGF-β1 on the bacteriophages demonstrated superior performance as a continuous stimulant in the microenvironment, effectively promoting these angiogenic processes. Assays, including RT-qPCR, ELISA, and fluorescence microscopy, confirmed the expression of angiogenic markers such as CD31, validating the formation of 3D angiogenic structures. Our findings indicate that the TGF-β1 displayed by bacteriophages likely acted as a chemotactic factor, promoting the migration, proliferation, and tube formation of endothelial cells (ECs) within the ECM. Although direct contact between ECs and bacteriophages was not explicitly confirmed, the observed effects strongly suggest that TGF-β1-RGD bacteriophages contributed to the stimulation of angiogenic processes. The formation of angiogenic structures by ECs in the ECM was confirmed as three-dimensional and regulated by the surface treatment of microfluidic channels. These results suggest that biocompatible TGF-β1-displaying bacteriophages could continuously stimulate the microenvironment in vitro for angiogenesis models. Furthermore, we demonstrated that these functionalized bacteriophages have the potential to be utilized as versatile biomaterials in the field of biomedical engineering. Similar strategies could be applied to develop angiogenic matrices for tissue engineering in in vitro assays. Full article

In trauma and surgery, efficient hemorrhage control is crucial to avert fatal blood loss and increase the likelihood of survival. There is a significant demand for novel biomaterials capable of promptly and effectively managing bleeding. This study aimed to develop flexible biocomposite fibrous scaffolds with an electrospinning technique using silk fibroin (SF) and indocyanine green (ICG). The FDA-approved ICG dye has unique photothermal properties. The water permeability, degradability, and biocompatibility of Bombyx mori cocoon-derived SF make it promising for biomedical applications. While as-spun SF-ICG fibers were dissolvable in water, ethanol vapor treatment (EVT) effectively induced secondary structural changes to promote β-sheet formation. This resulted in significantly improved aqueous stability and mechanical strength of the fibers, thereby increasing their fluid uptake capability. The enhanced SF-ICG interaction effectively prevented ICG leaching from the composite fibers, enabling them to generate heat under NIR irradiation due to ICG’s photothermal properties. Our results showed that an SF-ICG 0.4% fibrous matrix can uptake 473% water. When water was replaced by bovine blood, a 25 s NIR irradiation induced complete blood coagulation. However, pure silk did not have the same effect. Additionally, NIR irradiation of the SF-ICG fibers successfully stopped the flow of blood in an in vitro model that mimicked a damaged blood vessel. This novel breakthrough offers a biotextile platform poised to enhance patient outcomes across various medical scenarios, representing a significant milestone in functional biomaterials. Full article

To functionalize the NiTi alloy, multifunctional innovative nanocoatings of Ag-TiO₂ and Ag-TiO₂ doped with hydroxyapatite were engineered on its surface. The coatings were thoroughly characterized, focusing on surface topography and key functional properties, including adhesion, surface wettability, biocompatibility, antibacterial activity, and corrosion resistance. The electrochemical corrosion kinetics in a simulated body fluid and the mechanisms were analyzed. The coatings exhibited hydrophilic properties and were biocompatible with fibroblast and osteoblast cells while also demonstrating antibacterial activity against E. coli and S. epidermidis. The coatings adhered strongly to the NiTi substrate, with superior adhesion observed in the hydroxyapatite-doped layers. Conversely, the Ag-TiO₂ layers showed enhanced corrosion resistance. Full article