Journal of Materials Chemistry B最新文献

Dense biological tissues present formidable transport barriers that limit therapeutic penetration. Ultrasound-mediated propulsion can help to cross these barriers, but the presence of viscoelastic media can dampen ultrasonic cavitation and particle movement. The effect of gelatin (2–8% w/v) hydrogel mechanical properties (G′ ∼100–2100 Pa) on cavitation-mediated nanoparticle transport was tested using phospholipid-coated, hydrophobically modified mesoporous silica nanoparticles (DBPC HMSNs) and high-intensity focused ultrasound (HIFU). The minimum duty cycle required for effective penetration increased with hydrogel stiffness: 0.5% for 2% gelatin, 1.0% for 4% gelatin, and 3.6% for 8% gelatin. Soft hydrogels (2–4%) developed localized microchannels and release of gelatin from the gels only when treated with DBPC HMSNs under HIFU, but maintained their bulk mechanical properties. Stiff 8% gelatin exhibited organized honeycomb structures with 20–40% modulus reduction and amine release even in non-cavitating controls, indicating bulk weakening across all treatment groups. Non-cavitating control particles (unmodified MSNs) showed minimal penetration across all conditions, confirming cavitation as the primary driver of particle transport. SEM revealed treatment-dependent morphological changes across all HIFU-treated gels, including the formation of micropores and organized structures. These findings reveal that soft hydrogels (100–450 Pa) allow localized cavitation-mediated transport while preserving bulk integrity, whereas stiffer (>1000 Pa) hydrogels require higher acoustic intensities that inevitably cause bulk mechanical weakening. This stiffness-dependent response suggests that effective translation to biological barriers will require matching ultrasound parameters to target tissue mechanics.

In this work, we have developed hierarchically porous phosphate-based glasses (PPGs) as novel materials capable of promoting wound closure and simultaneously delivering antibacterial effects at the glass-biological tissue interface. PPGs are characterised by extended porosity, which enhances the controlled release of therapeutic ions, whilst facilitating cell infiltration and tissue growth. Two series of PPGs in the systems P₂O₅–CaO–Na₂O–CuO and P₂O₅–CaO–Na₂O–Ga₂O₃ with (CuO and Ga₂O₃ 0, 1, 5 and 10 mol%) were manufactured using a supramolecular sol–gel synthesis strategy. Significant wound healing promotion (up to 97%) was demonstrated using a human ex vivo wound model. A statistically significant reduction of the bacterial strains Staphylococcus aureus and Escherichia coli was observed in both series of PPGs, particularly those containing copper. All PPGs exhibited good cytocompatibility on keratinocytes (HaCaTs), and analysis of PPG dissolution products over a 7-day period demonstrated controlled release of phosphate anions and Ca, Na, Cu, and Ga cations. These findings indicate that Cu- and Ga-loaded PPGs are promising materials for applications in soft tissue regeneration given their antibacterial capabilities, in vitro biocompatibility with keratinocytes and ex vivo wound healing properties at the biomaterial-human tissue interface.

The damages caused by ultraviolet (UV) radiation to the skin have become a global public health concern. Long-term exposure to UV radiation can lead to serious consequences, such as sunburn, tanning, photoaging, and even skin cancer. As a key product for resisting UV damage, sunscreen has attracted much attention for its effectiveness and safety. Avobenzone is an important chemical sunscreen agent that is widely used in sunscreen products due to its excellent protective effect against long-wave UVA radiation. However, avobenzone has drawbacks such as poor photostability. Therefore, we linked avobenzone, ferulic acid, and ergothioneine together through intermolecular forces to form dual supramolecular avobenzone–ferulic acid–ergothioneine (AVB–FA–EGT). The dual supramolecular AVB–FA–EGT exhibited enhanced broad-spectrum UV resistance, photostability (up to 8 h), and sun-protection effect (sun protection factor increased by 15.93 times). In addition, the dual supramolecular AVB–FA–EGT exhibited strong antioxidant properties and biocompatibility, negligible permeability, and outstanding safety performance. Supramolecular avobenzone provides a new approach for the development of high-performance, bio-based, photoprotective sunscreens.

With the growing prevalence of early childhood caries (ECC), there is an urgent need to develop effective strategies for caries prevention. Investigation of oral metabolomic microenvironments among caries-free children could provide valuable insights. Therefore, this study aims to identify a “dominant metabolite” from plaque biofilms in children with varying levels of dental caries and to assess the biological attributes of this metabolite. A case-control study, combined with untargeted metabolomics, was conducted among three groups: caries-free (CF), low ECC (LECC), and high ECC (HECC). Then, the biological properties of this “dominant metabolite” were evaluated by biocompatibility analysis, bacterial growth and acid production assessment, biofilm targeting and remineralization test. This “dominant metabolite” was conjugated with a known antibacterial peptide Arg-Trp-Trp-Arg-Trp-Trp (RWWRWW), and the caries preventive effect of this compound was evaluated in vitro and in vivo. This study included 102 children aged 36 months. Metabolomic analysis revealed that Ala-Val-His-Ser (AVHS) was the most abundant metabolite in the CF group (P < 0.05), with moderate predictive performance (AUC = 0.675). AVHS has good biocompatibility; it can slow down the growth and acid production of Streptococcus mutans and effectively target plaque biofilm. The AVHS@RWWRWW conjugate exhibited superior antibiofilm effects in vitro and significantly reduced caries in rats than in the control group (P < 0.05). In conclusion, AVHS not only exhibits modest predictive performance for healthy children in clinical research but also demonstrates multiple biological functions. AVHS@RWWRWW shows better antibiofilm effect and can promote caries prevention, making it a promising candidate for development as a preventive agent.

This study presents a molecular-weight-engineered strategy for room-temperature 3D printing of osteogenic PLA/PCL/n-HA scaffolds, where PLA's molecular weight (M_w) governs printability and structural fidelity. We demonstrate that low-M_w PLA (LPLA, ∼9.0 × 10⁴ g mol⁻¹) leads to mechanical instability with filament collapse and nozzle clogging due to insufficient chain entanglement (5.9 × 10³ mol mm⁻³), while medium- (MPLA, 4.7 × 10⁵ g mol⁻¹) and high-M_w PLA (HPLA, 5.9 × 10⁵ g mol⁻¹) achieve stable extrusion and complex architectures (overhangs/grids) through enhanced entanglement densities (7.16 × 10³ and 12.1 × 10³ mol mm⁻³, respectively). Dynamic mechanical analysis reveals HPLA's superior performance, maintaining a storage modulus (E′) of 8.1 MPa at 100 °C versus LPLA's 2.8 MPa, with residual E′ post-glass transition following LPH < MPH < HPH, directly correlating with entanglement density. This molecular design enables precise control over extrusion dynamics and filament strength, eliminating the need for high-temperature processing. The optimized HPH composite ink (HPLA/PCL/n-HA) exhibits shear-thinning behavior, rapid solidification, and self-supporting porosity (>65%), while n-HA incorporation ensures bone-mimetic mechanics (Young's modulus ∼9 MPa) and osteoconductivity (∼20% new bone volume in vivo at 12 weeks). By establishing PLA M_w as a critical parameter for balancing extrudability and mechanical stability, this work advances solvent-based composite inks for room-temperature fabrication of patient-specific scaffolds, with broad implications for precision tissue engineering.

Pancreatic carcinoma ranks among the most aggressive malignancies. Although chemotherapeutic agents constitute the cornerstone of treatment regimens, drug resistance and dose-limiting toxicities significantly compromise therapeutic efficacy, necessitating innovative antitumor agents. In this study, two transition metal complexes, Co-MGC and Ni-MGC, were synthesized using 4-((4-(pyridin-3-yl)pyrimidin-2-ylamino)methyl)benzoic acid (MGC) as the ligand via solvothermal synthesis. Molecular docking simulations revealed their capacity to bind DNA base pairs through hydrogen bonding and intercalate into the duplex, thereby disrupting DNA structural integrity. Subsequently, the mechanism was verified by FS-DNA using agarose gel electrophoresis, UV-Vis spectroscopy, and fluorescence spectroscopy. FITC labeling confirmed cellular uptake, while DCFH-DA and JC-1 probes demonstrated intracellular ROS generation and reduction in the high mitochondrial membrane potential (ΔΨ_m) cell population to 65.53% (Co-MGC) and 71.9% (Ni-MGC), respectively. Cytotoxicity analysis revealed that Co-MGC and Ni-MGC exhibited half-maximal inhibitory concentrations (IC₅₀) of 8.28 µM and 10.23 µM, respectively, against BxPC-3 cells. Both of the complexes induced apoptosis over 35% at lower dose.

Bloodstream infections caused by Candida spp. are among the leading hospital-acquired infections, but their diagnosis remains slow and challenging with conventional culture-based methods, which often require days to deliver results. This study aimed to develop a rapid and sensitive diagnostic strategy for the detection and quantification of Candida spp. directly from blood samples. We designed a workflow combining antibody-modified magnetic beads for pathogen isolation, magnetic SERS (surface-enhanced Raman scattering)-encoded tags for multiplexed detection, and fluorescence microscopy for rapid prescreening. Data analysis was automated using machine learning, including convolutional neural networks for image classification and self-organizing maps for spectral analysis. This method enabled the detection and quantification of seven clinically relevant Candida species (C. albicans, C. glabrata, C. tropicalis, C. auris, C. haemulonii, C. dubliniensis, and C. parapsilosis) in 7.5 mL of whole blood at septicemia-relevant concentrations as low as 2 CFU mL⁻¹, with the results obtained in 4–5 hours. High specificity was demonstrated, with minimal cross-reactivity against bacterial controls. This integrated approach represents a rapid, sensitive, and multiplex alternative to current diagnostics, with the potential to improve the early detection and targeted treatment of candidemia, thereby enhancing the clinical outcomes and reducing the healthcare burden.

Accurate and sensitive detection of tumor biomarkers is critical for early cancer diagnosis and prognosis. In this study, a NiMoO₄@C₃N₅ hybrid nanostructure-modified glassy carbon electrode was developed for the amperometric detection of vanillylmandelic acid (VMA), a key biomarker for neuroblastoma and pheochromocytoma. The NiMoO₄ nanorods were synthesized using a sonochemical method, while C₃N₅ nanosheets were prepared by thermal polymerization, and their integration into a hybrid composite was achieved through ultrasonic-assisted dispersion. The hybrid composite was prepared through ultrasonic-assisted dispersion, combining the high conductivity of NiMoO₄ with the large surface area of C₃N₅ to enhance charge transfer. The structural and morphological characteristics of the synthesized materials were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Electrochemical characterization using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed the superior charge transfer properties of the NiMoO₄–C₃N₅ hybrid, attributed to the synergistic effect of the high conductivity of NiMoO₄ nanorods and the large surface area of C₃N₅ nanosheets. The sensor exhibited an excellent amperometric (i–t) response towards VMA oxidation using the electrolyte, 0.1M of PBS (pH 3.0) at an applied potential of 0.95 V, with a wide linear detection range of 0.0125 to 183.66 μM and an ultra-low limit of detection of 1.5 nM. The high sensitivity, excellent anti-interference capability, and long-term stability of the modified electrode were demonstrated through selective detection studies in the presence of common interfering biomolecules. Real sample analysis performed with spiked human urine and blood samples showed high recovery rates, confirming the sensor's applicability in clinical diagnostics. The synergistic combination of NiMoO₄ nanorods and C₃N₅ nanosheets represents a novel approach that improves sensitivity and stability compared to existing sensors, making it suitable for point-of-care tumor biomarker detection.

Reactive oxygen species (ROS)-mediated tumor therapy modalities, such as sonodynamic and chemodynamic therapy (SDT/CDT), hold great potential for the treatment of gallbladder cancer owing to their non-invasiveness, specificity, and high penetration depth. However, sonosensitizers and nanozymes often suffer from low ROS production efficiency and poor TME susceptibility. Herein, we report for the first time the ROS production amplification strategy through ion doping and vacancy engineering, which can not only improve the sonodynamic activity of sonosensitizers but also enhance the chemodynamic properties of nanozymes. The synergistic modifications enhance the SDT and CDT performances of pristine Co₉S₈ sonozymes through the following aspects: (1) S vacancies narrow the bandgap of Co₉S₈ sonozymes (1.41 eV vs. 1.91 eV) for enhanced SDT; (2) Cu doping improves the Co²⁺/Co³⁺ (0.98 vs. 0.66) of Co₉S₈ sonozymes for augmented CDT; and (3) Cu-doped Co₉S_8−x (Cu–Co₉S_8−x) retains GSH depletion ability for the cascade amplification of ROS production. Overall, significant antitumor effects have been observed to eliminate tumors through Cu–Co₉S_8−x-mediated SDT and CDT. This study provides promising insights into the development of enhanced sonozyme nanoplatforms through ion doping and vacancy engineering.

This study explores the design and synthesis of an innovative thermoresponsive nanocomposite for applications in drug delivery and controlled release. The nanocomposite core consists of carbon dots (CDs), covered by functionalized agarose units tethered to poly(N-isopropylacrylamide) (PNM), a thermoresponsive polymer with a lower critical solution temperature (LCST) of approximately 32 °C. Upon irradiation at 405 nm, localized heating within the CD core is efficiently transferred to the PNM shell through agarose linkages, resulting in modulation of the LCST toward physiologically relevant temperatures, optimal for biomedical applications. The structural integrity and composition of the CDs–agar–PNM nanocomposite were confirmed through ATR-FTIR spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and scanning electron microscopy (SEM). Transmission electron microscopy (TEM) revealed the hierarchical structure of the material, showing ∼7 nm primary carbon domains aggregated into compact spherical nanostructures (∼200 nm) after PNM functionalization. Dynamic light scattering (DLS) analyses revealed that the coil-to-globule transition of PNM occurs at temperatures exceeding 34 °C. UV-Vis spectroscopy demonstrated effective loading of curcumin and its temperature-dependent release, with drug release triggered above the LCST threshold. Molecular dynamics (MD) simulations supported the experimental findings and provided additional mechanistic insight into the influence of the PNM chain length. The simulations revealed that longer polymer chains exhibit stronger adsorption onto agarose surfaces, mediated by increased hydrogen bonding, a higher number of intermolecular contacts, and more favorable interaction energies, ultimately resulting in an elevated LCST. The CDs–agar–PNM nanostructures composed of a C-sp² inner core and an agarose–PNM outer shell showed good photothermal conversion properties (η = 38.8 ± 2.8%), blue-green photoluminescence yield and low cytotoxicity. Photophysical properties were demonstrated by the photogeneration of Au nanostructures upon 300 nm light exposure, according to the calculated semiconductor band-gap value of 2.45 eV. In summary, the synthesized nanocomposite exhibits enhanced thermal responsiveness, robust photothermal properties, and high structural stability, making it a promising platform for targeted cancer therapy and precision drug delivery applications.