Search Results (5,528)

Collagen hydrogels serve as biomimetic scaffolds that closely resemble the natural extracellular matrix, thus providing an ideal 3D biocompatible environment for cells. However, based on our previous experience, not all collagen isolates are capable of gelling, which appears to depend on the type, origin, species, age and sex of the source animal and the collagen isolation method applied. We therefore decided to evaluate porcine collagen-rich materials isolated from two different porcine genotypes applying two different specific isolation methods, and to analyse other main components, i.e., lipids and glycosaminoglycans, as well as amino acid composition and structural and morphological properties. While all the collagen isolates obtained were subjected to the gelling process, only one of them successfully gelled. In addition, the gelling ability of this isolate was confirmed repeatedly on collagens that were isolated from other pigs of the same porcine genotype. The results revealed that the gelling process proceeds via cooperation between the composition and the structure of the collagen isolate. With respect to the composition, one of the most important factors in terms of the success of the gelation process of collagen isolates concerns elevated glycosaminoglycan contents. The structural factors that characterise collagen isolates, i.e., cross-links (immature and mature) and their mutual ratio, as well as the presence of telopeptides, strongly impact the progress of the gelling process and the resulting character of the hydrogel structure. All these factors are influenced by the isolation procedure. Full article

Lubricating oils are utilised in equipment and machinery to reduce friction and enhance material utilisation. The utilisation of oil leads to an increase in its thickness and density over time. Current methods for assessing oil life are slow, expensive, and complex, and often only applicable in laboratory settings and unsuitable for real-time or field use. This leads to unexpected equipment failures, unnecessary oil changes, and economic and environmental losses. A comprehensive review of the extant literature revealed no studies and no national or international patents on neural network algorithm-based oil life modelling and classification using green sensors. In order to address this research gap, this study, for the first time in the literature, provides a green conductivity sensor with high-accuracy prediction of oil life by integrating real-time field measurements and artificial neural networks. This design is based on analysing resistance change using a relatively low-cost, three-dimensional, eco-friendly sensor. The sensor is characterised by its simplicity, speed, precision, instantaneous measurement capability, and user-friendliness. The MLP and LVQ algorithms took as input the resistance values measured in two different oil types (diesel, bench oil) after 5–30 h of use. Depending on their degradation levels, they classified the oils as ‘diesel’ or ‘bench oil’ with 99.77% and 100% accuracy. This study encompasses a sensing system with a sensitivity of 50 µS/cm, demonstrating the proposed methodologies’ efficacy. A next-generation decision support system that will perform oil life determination in real time and with excellent efficiency has been introduced into the literature. The components of the sensor structure under scrutiny in this study are conducive to the creation of zero waste, in addition to being environmentally friendly and biocompatible. The developed three-dimensional green sensor simultaneously detects physical (resistance change) and chemical (oxidation-induced polar group formation) degradation by measuring oil conductivity and resistance changes. Measurements were conducted on simulated contaminated samples in a laboratory environment and on real diesel, gasoline, and industrial oil samples. Thanks to its simplicity, rapid applicability, and low cost, the proposed method enables real-time data collection and decision-making in industrial maintenance processes, contributing to the development of predictive maintenance strategies. It also supports environmental sustainability by preventing unnecessary oil changes and reducing waste. Full article

Objective: This study aimed to evaluate the color stability and microhardness of two resin composites, a BPA-based composite (Luna) and a BPA-free composite (Luna 2), after immersion in chlorhexidine (CHX), using two different polishing protocols. Methods: Disks (7 mm diameter × 2 mm thickness) were prepared and divided into three groups per material: unpolished, Sof-Lex, and FlexiDisc polished (n = 20 per group). The specimens were immersed daily in either 0.12% CHX or distilled water for 21 days. Color change (ΔE) was measured at 7, 14, and 21 days using a spectrophotometer. Microhardness was evaluated at each time point using a Vickers hardness tester (200 g load, 10 s dwell time). Results: Luna 2 exhibited significant discoloration from day 14, while Luna showed significant color change on day 21 (p < 0.05). After 21 days of CHX immersion, unpolished Luna reached a ΔE value of 6.27 ± 1.69, exceeding the clinically acceptable threshold. At 14 days, Sof-Lex polishing significantly improved color stability compared to unpolished controls for both materials (p < 0.05). No significant differences were observed between the two polishing systems over time (p > 0.05). Luna 2 demonstrated significantly higher microhardness at all evaluated time points (p < 0.001). Both composites exhibited slight reductions in microhardness over time, which were more pronounced in Luna (p < 0.001). Conclusions: Polishing enhanced the color stability of both composites. Luna 2 exhibited superior microhardness compared to Luna, and polishing had no significant effect on this property. Given the increasing clinical shift toward BPA-free materials due to biocompatibility concerns, these findings offer relevant guidance for optimizing the long-term esthetic and mechanical performance of modern resin-based restorations. Full article

Hydrogel films are a promising class of materials due to their peculiar property of retaining water as well as responding to external stimuli. In contrast with conventional hydrogels, films provide enhanced responsiveness along with greater compliance to be integrated into devices as well as on surfaces. This review is designed to comprehensively explore the many aspects of hydrogel films. It covers the principles of gelation; preparation methods, such as solvent casting, spin coating, and photolithography; and characterization. This review also presents the most common polymers (both natural and synthetic) utilized for the preparation of the hydrogel, the systems, such as nanoparticles, liposomes and hybrid metal–organic structure, that can be used as additives and the aspects related to the biocompatibility of hydrogels. In the second part, this review discusses the potential applications of hydrogel films and the challenges that still need to be overcome. Particular attention is given to biomedical applications, such as drug delivery, wound healing, and tissue engineering, but environmental and agricultural uses are also explored. Finally, this review presents recent examples of real-world applications of hydrogel films and explores the possibility they have for a wide variety of needs. Full article

The research of biomaterials is an area of significant interest in the biomedical field, and the present study investigates how the strontium (Sr) concentration influences the microstructure, corrosion resistance, and both in vitro and in vivo behavior of alloys in the ternary Mg-Ca-Sr system. Using an induction furnace with a controlled atmosphere (argon as the shielding gas), Mg-0.5Ca-xSr alloys (x = 0.5; 1; 1.5; 2; 3 at.%) were synthesized. Microstructural analyses, performed using optical microscopy and scanning electron microscopy (SEM), revealed a uniform and refined structure. Corrosion behavior assessments, carried out using linear and cyclic potentiometry, demonstrated favorable corrosion resistance for all samples. However, for the system containing 0.5% Sr, the corrosion rate values were lower compared to the other systems, and this alloy also exhibited the lowest corrosion current density. Cytocompatibility assay indicated the cytocompatible behavior of all the studied alloys, with favorable influence on cell viability and a stimulatory effect on the osteoblastic cell proliferation. In vivo biocompatibility assessments of the alloys showed that, for alloys containing 0.5% and 1% Sr, a more rapid degradation occurred in comparison with the other alloys (1.5, 2 and 3% Sr), which still persisted at the tissue level even after 12 weeks post-implantation. In all the batches examined, the inflammatory reaction was directly proportional and persistent in relation to the presence of the material in the tissue. In regions where the material was resorbed/degraded, the local inflammatory response was reduced or absent, and the fibrous tissue was denser and better organized. The field of biomaterials is in continuous development, and this study highlighted the applicability of these five alloy systems for dental and maxillofacial applications such as implants, plates, and related devices. Full article

Laser-induced forward transfer (LIFT) bioprinting enables precise deposition of biological materials for advanced biomedical applications. This study presents a parametric analysis of the donor–receiver distances (1.0, 1.5, 2.0, 2.5, and 3.0 mm) in LIFT bioprinting, investigated through high-speed video and image analysis of 4 × 4 spot arrays. Droplet velocity was quantified and jet trajectory characterized, revealing that increased distances reduced spatial resolution, with significant shape deterioration observed beyond 2.0 mm. Thus, a maximum 2.0 mm donor–receiver gap was determined as optimal for acceptable printing resolution. As an application, a microfluidic device was fabricated using LCD 3D printing with a biocompatible resin and glass-bottomed configuration. The chamber height was matched to the validated 2.0 mm distance, ensuring compatibility with LIFT printing. Computational fluid dynamics simulations were conducted to model fluid flow conditions within the device. Subsequently, LLC cells were successfully printed inside the microfluidic chamber, cultured under continuous flow for 24 h, and demonstrated normal proliferation. This work highlights LIFT bioprinting’s viability and precision for integrating cells within microfluidic platforms, presenting promising potential for organ-on-chip applications and future biomedical advancements. Full article

In recent years, research into the synthesis of innovative biomaterials for prosthetic applications has been increasingly growing. In particular, there is a demand for biomaterials with an excellent biocompatibility that can interact with biological fluids. This study involved the development of new silica (SiO₂)-based composite materials using the sol–gel technique and functionalization with ferulic acid (FA), a natural phenolic compound renowned for its biological properties. The synthesis involved controlling the hydrolysis and condensation of tetraethyl orthosilicate (TEOS) in acidic and alcoholic environments to incorporate ferulic acid into the sol phase matrix at different weight compositions (5, 10, 15, and 20 wt%). Fourier transform infrared spectroscopy analyses (FTIR) confirmed the successful incorporation of the bioactive compound, and in vitro tests revealed a good cytocompatibility and controlled ferulic acid release over time. These results demonstrate that the developed material shows promise as a bioactive coating for orthopedic prostheses, improving bone integration and reducing undesirable post-operative phenomena. Full article

Photobiomodulation (PBM) harnesses near-infrared (NIR) light to stimulate cellular processes, offering non-invasive treatment options for a range of conditions, including chronic wounds, inflammation, and neurological disorders. NIR light-emitting diodes (LEDs) are emerging as safer and more scalable alternatives to conventional lasers, but optimizing their performance for clinical use remains a challenge. This perspective explores the latest advances in NIR-emitting materials, spanning Group III–V, IV, and II–VI semiconductors, organic small molecules, polymers, and perovskites, with an emphasis on their applicability to PBM. Particular attention is given to the promise of perovskite LEDs, including lead-free and lanthanide-doped variants, for delivering narrowband, tunable NIR emission. Furthermore, we examine photonic and plasmonic engineering strategies that enhance light extraction, spectral precision, and device efficiency. By integrating advances in materials science and nanophotonics, it is increasingly feasible to develop flexible, biocompatible, and high-performance NIR LEDs tailored for next-generation therapeutic applications. Full article

Cardiovascular disease is a leading cause of global mortality. Percutaneous coronary intervention, which involves the placement of stents to restore blood flow in narrowed arteries, is a widely used treatment. However, traditional stents, such as bare metal stents and drug-eluting stents, can lead to long-term complications such as restenosis, inflammation, and thrombosis. Biodegradable metallic vascular stents, with their superior mechanical properties, excellent biocompatibility, and gradual degradation in vivo, hold significant potential for the treatment of coronary artery disease. This review provides a comprehensive overview of the current research status and challenges. Firstly, it outlines the design principles and performance evaluation methods for biodegradable stents, which focus on mechanical properties, chemical characteristics, corrosion behavior, and biocompatibility. Furthermore, it summarizes the material features, degradation mechanisms, and metabolic behavior of three primary biodegradable metals—magnesium alloys, iron alloys, and zinc alloys—and discusses critical issues such as the degradation rate of different alloys and the development of zinc alloys. Finally, based on the current achievements and challenges of studies on biodegradable metal-based stents, this article proposes some optimization strategies and research prospects. Full article

Liquid metal (LM), which possesses unique material properties such as excellent flexibility, high thermal and electrical conductivities, and biocompatibility, has demonstrated broad application potential in the fields of intelligent manufacturing, flexible electronics, and biomedical engineering. This paper presents a systematic review of recent advances in multifunctional LM materials for biomimetic applications, with a focus on 3D printing, catalysis, sensing, and biomedical technologies. Through advanced 3D printing techniques—including direct writing, embedded printing, and extrusion/infiltration—LM has been effectively utilized in the fabrication of high-precision electronic components. In catalysis, LM-based catalysts exhibit superior performance in energy conversion and environmental remediation due to their high catalytic activity and selectivity. Moreover, LM has made notable progress in the development of high-performance sensors and biomedical devices, contributing significantly to the advancement of health monitoring and intelligent diagnostic and therapeutic technologies. This review aims to provide theoretical insights and technical references for further research and engineering applications of liquid metals. Full article

The aim of this study was to evaluate the haemostatic potential and biocompatibility of a newly developed composite material for its use in blood-contacting applications. Based on promising reports on polylactide (PLA), sodium alginate (ALG), and bioactive additives such as hardystonite (HT) and zinc sulphide (ZnS), a melt-blown PLA nonwoven was modified via dip-coating using an ALG solution as a matrix for incorporating HT and ZnS particles, resulting in the PLA-ALG-ZnS-HT composite. The material was characterised in terms of surface morphology, specific surface area, pore volume, average pore size, and zeta potential (pH~7.4). Haemostatic activity was assessed by measuring blood coagulation parameters, while biocompatibility was evaluated through the viability of human peripheral blood mononuclear (PBM) cells and human foreskin fibroblasts (Hs68). Genotoxicity was analysed using the comet assay and plasmid relaxation test. Results confirmed a uniform alginate coating with dispersed HT and ZnS particles on PLA fibres. The modification increased the surface area and pore volume and caused a shift toward less negative zeta potential. Haemostatic testing showed prolonged activated partial thromboplastin time (aPTT), likely due to Zn²⁺ interactions with clotting factors. Biocompatibility tests showed high cell viability and no genotoxic effects. Our findings suggest that the PLA-ALG-ZnS-HT composite is safe for blood and skin cells and may serve as an anticoagulant material. Full article

The demand for antimicrobial and biocompatible materials in biomedical applications continues to grow, particularly in the context of wound care and textiles. This study explores the development of multifunctional coatings by applying magnesium (Mg) nanoparticles onto medical-grade cotton textiles using magnetron sputtering—a solvent-free and environmentally sustainable technique. A comprehensive material characterization confirmed the formation of Mg, MgO and Mg(OH)₂/MgH₂ phases, along with generally consistent particle coverage and increased fiber surface roughness. The antibacterial testing revealed the effective inhibition of both Gram-positive and Gram-negative bacteria—except Enterococcus faecalis. Additionally, the growth of the fungus Candida albicans and the microalgae Prototheca spp. was reduced by over 80%. Importantly, a cytocompatibility evaluation using human umbilical vein endothelial cells (HUVECs) demonstrated not only non-toxicity but a significant increase in cell viability after 72 h, particularly in samples treated for 20 and 60 min, indicating a potential cytoprotective and proliferative effect. These findings highlight the dual functionality of plasma-sputtered Mg nanoparticle coatings, offering a promising strategy for the development of eco-friendly, antimicrobial and cell-supportive medical textiles. Full article

Micellar or mycelial membranes from medicinal mushrooms are self-growing fibrous polymeric biocomposites that are biocompatible, biodegradable, cost-effective, and environmentally friendly. In this study, the cultivation process for the medicinal mushrooms Ganoderma lucidum and Pleurotus ostreatus has been optimized via submerged cultivation to maximize growth and promote the formation of micellar membranes with high water-absorption capacity. Optimal growth conditions were achieved at an alkaline pH in a medium containing malt extract for G. lucidum, while for P. ostreatus, these were in a glucose-enriched medium. The hydrophilic underside of the micellar membranes led to a high-water uptake capacity. These membranes exhibited a broad spectrum of functional groups, thermal stability with decomposition temperatures above 260 °C, and a fibrous and porous structure. The micellar membranes from both mushrooms were additionally functionalized with mango peel extract (MPE), resulting in a uniform and gradual release profile, which is an important novelty. They also showed successful antimicrobial activity against Escherichia coli and Staphylococcus aureus growth. MPE-functionalized micellar membranes are, therefore, innovative biocomposites suitable for various biomedical applications. As they mimic the extracellular matrix of the skin, they are a promising material for tissue engineering, wound healing, and advanced skin materials applications. Full article

Graphene quantum dots (QGDs), as nascent carbon-based materials, demonstrate remarkable promise in many different applications. Thanks to excellent electrical and thermal properties, great biocompatibility, feasibility of surface functionalization and low cytotoxicity, QGDs can be any material and have many applications, from elastic PV panels to drug delivery. This paper concentrates on relating the structure of the QGD (which is the result of the synthesis method used and consequently the variable degree of defect, the possible presence of functional groups especially in the defect region, etc.) to the resulting physicochemical properties. Therefore, the aim of this study is to theoretically relate and determine the effect of defect amount and type on the value of the HOMO–LUMO gap with respect to possible QGD luminescence colors. Finally, it presents a direction in new graphene-based materials synthesis, where every single defect has a huge impact on its properties. Full article

Natural polymers, such as gelatin, offer a sustainable, green, and versatile alternative for developing proton exchange membranes in low-temperature fuel cell applications. They provide a balance of biocompatibility, flexibility, and ionic conductivity. In this work, gelatin-based composite membranes are reported. The membranes were fabricated and modified with various additives, including ionic liquids (ILs), polyethylene glycol (PEG), and glycerol, to enhance their electrochemical and mechanical properties. The proton conductivity of the pure gelatin membrane was relatively low at 1.0368 × 10⁻⁴ Scm⁻¹; however, the incorporation of IL ([DEMA][OMs]) significantly improved it, with the gelatin/0.2 g IL membrane achieving the highest conductivity of 4.181 × 10⁻⁴ Scm⁻¹. The introduction of PEG and glycerol also contributed to enhanced conductivity and flexibility. The water uptake analysis revealed that IL-containing membranes exhibited superior hydration properties, with the highest water uptake recorded for the gelatin/0.2 g glycerol/0.2 g IL membrane, which was found to be very high (906.55%). The results showed that the combination of IL and PEG provided enhanced proton transport and mechanical stability (as examined visually), making these membranes promising candidates for fuel cell applications. Therefore, this study underscores the importance of bio-based materials by utilizing gelatin as a sustainable, biodegradable polymer, supporting the transition toward greener energy materials. The findings demonstrate that modifying gelatin with conductivity-enhancing and plasticizing agents can significantly improve its performance, paving the way for bio-based proton exchange membranes with improved efficiency and durability. Full article