Search Results (583)

Early diagnosis of diseases would significantly increase the survival rate of cancer patients. However, current screening methods are complex and costly, making them unsuitable for rapid health diagnosis in daily life. Here, we develop a portable platform based on a planar-gate graphene field-effect transistor functionalized with polydopamine self-assembled film (PDA-GFET), capable of identifying colon cancer through the detection of EpCAM protein, which is expressed on colon cancer-derived exosomes, in clinical samples within 10 min. The PDA self-assembled film on the graphene and gate surface enhances the biosensor’s functionalization area while suppressing non-specific adsorption, thereby achieving detection limits as low as 112 particles/mL. In addition, the PDA-GFET-based detection platform was used to identify EpCAM protein in real clinical samples from healthy individuals and colon cancer patients within 10 min, and the two showed significant differences (p < 0.001). Results indicate that the proposed PDA-GFET-based detection platform is expected to be a potential tool for the early diagnosis of colon cancer. Full article

The practical application of flexible sensors in sound detection is significantly hindered by challenges such as information isolation, fragmentation, and low fidelity. To address these challenges, this work developed a composite hydrogel via a one-pot method, employing polyvinyl alcohol (PVA) as the first network, polyacrylic acid (PAA) as the second network, and two-dimensional nanomaterials—reduced graphene oxide (rGO)—generated through the redox reaction of polydopamine (PDA) and graphene oxide (GO) as conductive fillers. The uniformly distributed rGO within the hydrogel forms an efficient conductive network, endowing the material with high sensitivity (GF = 0.64), excellent conductivity (8.15 S m⁻¹), rapid response time (350 ms), and outstanding stability. The synergistic interaction between PDA and PAA modulates the hydrogel’s adhesion (0.89 kPa), enabling conformal attachment to skin surfaces. The designed rGO@PVA-PAA hydrogel-based flexible sensor effectively monitors vibrations across diverse frequencies originating from five vocal cavities (head, nasal, oral, laryngeal, and thoracic cavities) during singing. Integrated with multi-position synchronization and Bluetooth wireless sensing technologies, the system achieves coordinated and efficient monitoring of multiple vocal cavities. Furthermore, the hydrogel sensor demonstrates versatility in detecting physiological signals, including electrocardiograms, subtle vibrations, and multi-scale body movements, highlighting its broad applicability in biomedical and motion-sensing applications. Full article

Light exposure has relevant effects both on living organisms and artificial materials. In particular, ultraviolet radiation is known to kill living cells and damage human skin but also degrade important artificial materials like plastics. In nature, the main pigment responsible for photoprotection is melanin, which is able both to prevent penetration of light by absorption and scattering and to block the action of light-generated radicals thanks to its antioxidant properties. The combination of light extinction with antioxidant action is still the most diffused and effective approach to photoprotection. Nevertheless, up to now, these two mechanisms, light extinction and antioxidant activity, have been considered independent. Recent studies showed that exposing melanin to light leads to an increase in its radical content and possibly in its antioxidant activity. Do light extinction and antioxidant activity work in synergy for photoprotection in nature? In this paper, we discuss the steps still needed to answer this intriguing question. Full article

Wear resistance is the key factor that affects the long-term use of leather. Graphene has excellent wear resistance properties, but ensuring the effective dispersion of graphene in resin is crucial for determining the performance of the material. In this work, silica modified with polydopamine (SiO₂@PDA) was used as an exfoliation agent. Using the microfluidization process and water as the medium, silica-graphene hybrid nanoparticles (SiO₂@PDA-G) were prepared from expanded graphite. These nanoparticles were further compounded with waterborne polyurethane (WPU), and a superfine fiber-based fabric was used as the substrate to prepare composite coating. The results showed that the high shear force of the microfluidization process easily broke up the lamellar structure of graphite, resulting in few-layer graphene. Nano-silica was adsorbed on the surface of graphene, preventing re-aggregation between the graphene sheets. Compared to the WPU coating, the presence of SiO₂@PDA-G improved the wear resistance and mechanical properties of the coating. The wear rate and the average friction coefficient of the composite coating decreased by 48% and 69%, respectively, and the tensile strength increased by 83%. Therefore, this study provides a new strategy for improving the dispersion of graphene in polymer materials and enhancing the abrasion resistance of the coatings. Full article

The extracellular matrix (ECM) is a dynamic network providing mechanical and biochemical cues that regulate cellular behavior. ECM stiffness critically influences fibroblasts, the primary ECM producers, particularly in inflammation and fibrosis. This review explores the role of ECM stiffness in fibroblast-driven inflammation and tissue remodeling, focusing on the physicochemical and biological mechanisms involved. Engineered materials, hydrogels, and polydimethylsiloxane (PDMS) are highlighted for replicating tissue-specific stiffness, enabling precise control over cell–matrix interactions. The surface functionalization of substrate materials, including collagen, polydopamine, and fibronectin, enhances bioactivity and fibroblast adhesion. Key mechanotransduction pathways, such as integrin signaling and YAP/TAZ activation, are related to regulating fibroblast behaviors and inflammatory responses. The role of fibroblasts in driving chronic inflammatory diseases emphasizes their therapeutic potentials. Advances in ECM-modifying strategies, including tunable biomaterials and hydrogel-based therapies, are explored for applications in tissue engineering, drug delivery, anti-inflammatory treatments, and diagnostic tools for the accurate diagnosis and prognosis of ECM stiffness-related inflammatory diseases. This review integrates mechanobiology with biomedical innovations, providing a comprehensive prognosis of fibroblast responses to ECM stiffness and outlining future directions for targeted therapies. Full article

Efficient and precise cancer therapy remains a challenge due to limitations in current treatment modalities. In this study, we developed a multifunctional hydrogel system that integrates photothermal therapy (PTT) and chemotherapy to achieve combined tumor treatment. The hydrogel, composed of γ-polyglutamic acid (γ-PGA), fifth-generation polyamide-amine dendrimers (G5), and polydopamine (PDA) nanoparticles, exhibits high photothermal conversion efficiency and temperature-responsive drug release properties. The hydrogel exhibited a high photothermal conversion efficiency of 45.6% under 808 nm near-infrared (NIR) irradiation. Drug release studies demonstrated a cumulative hydrophilic anticancer drug doxorubicin DOX release of 79.27% within 72 h under mild hyperthermia conditions (50 °C). In vivo experiments revealed a significant tumor inhibition rate of 82.3% with minimal systemic toxicity. Comprehensive in vitro and in vivo evaluations reveal that the hydrogel demonstrates excellent biocompatibility, photothermal stability, and biodegradability. Unlike conventional hydrogel systems, our γ-PGA-based hydrogel uniquely integrates a biocompatible and biodegradable polymer with polydopamine (PDA) nanoparticles, providing a smart and responsive platform for precise cancer therapy. This multifunctional hydrogel system represents a promising platform that combines PTT precision and chemotherapy efficacy, providing a robust strategy for advanced and safer cancer treatment. Full article

Developing sustainable and efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for advancing energy storage technologies. This study explored the dual role of phosphorus as a dopant in carbon matrices and a key component in nickel phosphides (Ni₂P and Ni₁₂P₅), synthesized using dopamine (PDA) and ammonium phosphate as eco-friendly precursors. The phase formation of nickel phosphides was found to be highly dependent on the P/PDA ratio (0.15, 0.3, 0.6, and 0.9), allowing for the selective synthesis of Ni₂P or Ni₁₂P₅. Operando Raman spectroscopy revealed that both phases undergo surface transformation into nickel (oxy)hydroxide species under OER conditions, yet Ni₂P-based catalysts demonstrated superior activity and long-term stability. This enhancement is attributed to efficient electron transfer at the dynamic Ni₂P/NiOOH interface. Additionally, hollow nanostructures formed at intermediate P/PDA ratios (≤0.3) via the Kirkendall effect and Ostwald ripening contributed to an increased specific surface area and micropore volume, further improving the catalytic performance. Electrochemical impedance spectroscopy confirmed reduced interfacial resistance and enhanced charge transport. These findings offer new insights into the rational design of high-performance electrocatalysts and propose a green, tunable synthesis approach for advanced energy conversion applications. Full article

In recent years, hydrogels have emerged as promising candidates for bone defect repair due to their excellent biocompatibility, high porosity, and water-retentive properties. However, conventional hydrogels face significant challenges in clinical translation, including brittleness, low mechanical strength, and poorly controlled drug degradation rates. To address these limitations, as a multifunctional polymer, polydopamine (PDA) has shown great potential in both bone regeneration and drug delivery systems. Its robust adhesive properties, biocompatibility, and responsiveness to photothermal stimulation make it an ideal candidate for enhancing hydrogel performance. Integrating PDA into conventional hydrogels not only improves their mechanical properties but also creates an environment conducive to cell adhesion, proliferation, and differentiation, thereby promoting bone defect repair. Moreover, PDA facilitates controlled drug release, offering a promising approach to optimizing treatment outcomes. This paper first explores the mechanisms through which PDA promotes bone regeneration, laying the foundation for its clinical translation. Additionally, it discusses the application of PDA-based nanocomposite hydrogels as advanced drug delivery systems for bone defect repair, providing valuable insights for both research and clinical translation. Full article

Particulate matter (PM) and water pollution have posed serious hazards to human health. Nanofiber membranes (NFMs) have emerged as promising candidates for the elimination of PMs and the separation of oil–water mixtures. In this study, a polyvinylidene difluoride (PVDF)-based nanofiber membrane with an average diameter of approximately 150 nm was prepared via a double-nozzle electrospinning technology, demonstrating high-efficiency PM filtration and oil–water separation. The finer fiber diameter not only enhances PM filtration efficiency but also reduces air resistance. The high-voltage electric field and mechanical stretching during electrospinning promote high crystallization of β-phase PVDF. Additionally, the electrostatic charges generated on the surface of β-phase PVDF facilitate the adsorption of PM from the atmosphere. The introduction of polydopamine (PDA) in PVDF produces abundant adsorption sites, enabling outstanding filtration performance. PVDF-PVDF/PDA NFMs can achieve remarkable PM_0.3 filtration efficiency (99.967%) while maintaining a low pressure drop (144 Pa). PVDF-PVDF/PDA NFMs are hydrophobic, and its water contact angle (WCA) is 125.9°. It also shows excellent resistance to both acidic and alkaline environments, along with notable flame retardancy, as it can self-extinguish within 3 s. This nanofiber membrane holds significant promise for applications in personal protection, indoor air filtration, oily wastewater treatment, and environmental protection. Full article

Efficient dye sieving and salt separation can facilitate the recycling of valuable resources in textile wastewater treatment. This study focuses on developing a high-performance nanofiltration membrane (NF) by co-depositing activated polydopamine (O-PDA), oxidized with KMnO₄, and polyethyleneimine (PEI) onto a polysulfone support membrane (PSF), thereby enabling effective dye sieving and salt separation. Due to the high hydrophilicity of PDA and the formation of high molecular polymers after oxidation, it was anticipated that O-PDA would crosslink the PEI layer, providing rapid permeating channels. Filtration experiments demonstrated that the formation of O-PDA significantly enhanced the salt retention rate of nanofiltration membranes, achieving a nearly threefold increase in NaCl retention from 15% to 45.7%. It was observed that the retention performance of O-PDA could be adjusted by controlling its loading or oxidation level. Furthermore, despite a notable reduction in permeability, the dye removal efficiency of the O-PDA/PEI membrane increased substantially to 99.5%. Long-term filtration experiments also confirmed both the stability and anti-fouling properties of this membrane design. Clearly, owing to its excellent operational stability and anti-fouling characteristics, the O-PDA/PEI membrane exhibits great potential for applications in dye sieving and salt separation. Full article

Prosthetics, a rapidly advancing field in dentistry, aims to improve patient comfort and aesthetics by addressing the challenge of replacing missing teeth. A critical obstacle in dental implantation is the condition of the jawbone, which often necessitates reconstruction prior to implant placement. Guided bone regeneration (GBR) and guided tissue regeneration (GTR) techniques utilize membranes that act as scaffolds for bone and tissue growth while serving as barriers against rapidly proliferating cells and pathogens. Commonly used membranes, such as poly(tetrafluoroethylene) (PTFE) and collagen, have significant limitations—PTFE is non-bioresorbable and requires secondary removal, while collagen lacks adequate mechanical strength and exhibits unpredictable degradation rates. To overcome these challenges, nanofiber membranes produced via electrospinning using polylactic acid (PLA) were developed. The novel composites were functionalized with bioactive additives, including periclase (MgO) nanoparticles and polydopamine (PDA), to enhance osteoblast adhesion, antibacterial properties, and tissue regeneration. This study comprehensively evaluated the biological, mechanical, and physicochemical properties of the prepared nanofibrous scaffolds. Experimental results revealed controlled degradation rates and improved hydrophilicity due to surface modifications with PDA and MgO. Moreover, the nanofibers exhibited enhanced swelling behavior, which promoted nutrient exchange while maintaining structural integrity over prolonged periods. The incorporation of bioactive additives contributed to superior osteoblast proliferation, antibacterial activity, and growth factor immobilization, supporting bone tissue regeneration. These findings suggest that the developed nanofibrous composites are a promising candidate for GBR and GTR applications, offering a balanced combination of biological activity, mechanical performance, and degradation behavior tailored for clinical use. Full article

Background/Objective: Many novel solutions for a range of dental problems are emerging as a result of the quick development of nanotechnology and nanocomplex synthetic techniques. The effectiveness, quality, and negative consequences of these advancements are occasionally debatable, though. This systematic review sought to better summarize the existing additions of nanoparticles to dental adhesive systems in order to improve their performance and properties, evaluate their quality, and examine the results that have been published. Materials and methods: The present systematic review was carried out according to PRISMA guidelines. The search was carried out on PubMed central, Cochrane collaboration, Science direct and Scopus scientific engines. Selected MeSH keywords (nanoparticles, adhesive resin, enamel demineralization) were used for data extraction. A total of 13 full-text original articles were included in the final analysis, and these articles were based on adding nanoparticles to the adhesive resin to evaluate their effects on enamel demineralization. Results: The literature search resulted in a total of 13 original studies/articles up until November 2024. The text articles comprised in vitro studies with robust inclusion and exclusion criteria. The review included various types of adhesives and nanoparticles, with amorphous calcium phosphate (ACP) being the most common. Other nanoparticles included polydopamine–Ag, bioactive glass, and silver. Most studies assessed the effects of nanoparticles on adhesive shear bond strength (SBS), microbial growth, and microhardness. Only three studies investigated the effects of nanoparticles on microhardness using Vickers tests. Conclusions: The review found that adding nanoparticles to orthodontic dental adhesives enhances their antibacterial and anticariogenic properties without affecting the shear bond strength. This could prevent enamel demineralization during orthodontic therapy. Future research could benefit from these positive properties, necessitating an interdisciplinary approach. Full article

Boosting the accuracy and speed of cancer detection is highly desirous in tumor detection, and sensors capable of detecting carcinoembryonic antigen (CEA) have great application prospects in this field. A highly sensitive sensor is constructed based on the fluorescence resonance energy transfer (FRET) with heavily rare-earth-doped upconversion nanoparticles (UCNPs) as energy donors and polydopamine nanoparticles (PDA NPs) as energy acceptors. This sensor detects the fluctuations in CEA molecules via luminescence quenching and recovery resulting from a competitive binding assay between CEA and PDA NPs. The high-level-doped design of UCNPs (i.e., NaYF₄@NaYbF₄:1%Tm@NaYF₄) is beneficial, providing upconversion luminescence intensity that is more than 10 times higher than that of the conventional low-level-doped UCNPs (i.e., NaYF₄@NaYF₄:20%Yb, 0.2%Tm@NaYF₄). The sensor exhibits impressive sensitivity. Specifically, in diluted fetal bovine serum, the detection limit reaches 0.013 ng/mL in the range of 0–1.5 ng/mL (S/N = 3), while the detection limit is 1.38 ng/mL in the range of 1.5–250 ng/mL (S/N = 3). This method has great potential for future applications in the rapid and early diagnosis and treatment of cancer. Full article

MXenes, a family of 2D transition metal carbides, nitrides, and carbonitrides, have attracted significant attention due to their exceptional physicochemical properties and electrochemical performance, making them highly promising for diverse applications, particularly in energy storage. Despite notable advancements, MXene synthesis remains a critical challenge, as conventional methods often rely on hazardous hydrofluoric acid-based processes, posing substantial environmental and safety risks. In this study, we present an eco-friendly synthesis approach for MXenes using molten salt processes, which offer a safer, sustainable alternative while enabling scalable production. Additionally, we explore the development of high-performance battery anodes by fabricating nanocomposites of nano-silicon and MXene, followed by a bio-inspired polydopamine coating and carbonization process. This innovative strategy not only enhances the structural stability and electrochemical performance of the anodes but also aligns with environmentally conscious design principles. Our findings demonstrate the potential of eco-friendly MXene synthesis and nanocomposite materials in advancing sustainable energy storage technologies. Full article

The development of effective photocatalysts for environmental applications is still a critical aspect of green chemistry. This study explores copper oxide (Cu_xO) catalysts supported on titanium dioxide (TiO₂) and zinc oxide (ZnO) for the photocatalytic reduction of maleic acid to succinic acid under ultraviolet (UV) light in water. The main goal was to evaluate the performance of CuO/ZnO compared to CuO/TiO₂ in photoreduction. In order to improve the efficiency of the first catalyst, an environmentally friendly synthesis, assisted by polydopamine (PDA), was tested, obtaining the Cu₂O/ZnO-PDA catalyst. The results showed that CuO/TiO₂ exhibited the highest activity for maleic acid reduction, obtaining a succinic acid yield and a selectivity of 32% after 24 h of reaction time, but comparable results could be reached even with Cu₂O/ZnO-PDA increasing the reaction time. Furthermore, the addition of sodium ascorbate as a co-catalyst in the reaction mixture allowed us to overtake the previous results, leading to a succinic acid yield of 61% and a selectivity of 67%. These findings suggest that the PDA shell can be a solution for Cu_xO photodegradation, making Cu₂O/ZnO-PDA an alternative to the toxic CuO/TiO₂. Full article