Journal of materials chemistry. B最新文献

Correction for 'Acceptor-donor-acceptor-type molecules with large electrostatic potential difference for effective NIR photothermal therapy' by Kexin Fan et al., J. Mater. Chem. B, 2024, 12, 5140-5149, https://doi.org/10.1039/D4TB00187G.

Osteomyelitis is a serious inflammatory disease mostly caused by bacterial infections. It is necessary to simultaneously eradicate bacterial cells and inhibit inflammation in treating osteomyelitis. Herein, we design an innovative zinc ion (Zn²⁺)-based nano delivery system for the management of osteomyelitis. Taking advantage of the coordination self-assembly of Zn²⁺, quercetin (QU), and ε-poly-L-lysine (EPL), Zn²⁺-containing nanoparticles (denoted as ZQE NPs) are prepared. ZQE NPs are spherical nanoparticles with amorphous structures. They are stable in the physiological neutral environment but can be dissociated in an acidic microenvironment of infection sites. Since Zn²⁺ is encapsulated into ZQE NPs by coordination interaction, the deactivation of Zn²⁺ by proteins can be effectively avoided. Therefore, ZQE NPs can maintain excellent bactericidal activity in a protein-rich environment, while dissociative Zn²⁺ doesn't exhibit obvious bactericidal ability. Meanwhile, ZQE NPs are highly effective at scavenging intracellular reactive oxygen species (ROS) and inhibiting pro-inflammatory cytokines, due to the strong anti-inflammatory effects of QU and Zn²⁺. The in vivo therapeutic efficacy of ZQE NPs is assessed using a rat model of methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis. Results demonstrate that ZQE NPs effectively eradicate bacterial cells and reduce inflammation in vivo, thereby promoting osteogenesis and recovery of osteomyelitis.

Acoustic matching layers play an important role in ultrasonic transducers. However, the acoustic matching layer with both intrinsic flexibility and high acoustic impedance remains an unmet need to achieve high-performing flexible ultrasonic transducers. Herein, we present an epoxy/nano-zirconia composite with excellent flexibility and acoustic performance by the chemical coupling method. (3-Aminopropyl)triethoxysilane was used to effectively disperse nano-zirconia particles in epoxy resin, and endow the resultant composite with flexibility. After carefully adjusting the additions of nano-zirconia particles and (3-aminopropyl)triethoxysilane, the modulus of the epoxy/nano-zirconia composite was 4.5 MPa, combined with an elongation at break over 90%. The acoustic impedance of the epoxy/nano-zirconia composite (∼4.5 MRayl) exceeded that of other typical polymer counterparts. The flexible acoustic matching layer based on an epoxy/nano-zirconia composite could significantly improve the sensitivity and bandwidth of ultrasonic transducers. A fiber-shaped ultrasonic transducer with high sensitivity and wide bandwidth was fabricated, displaying promising application potential in wearable medical electronics.

Gold nanoparticles (AuNPs) play a key role in the field of nanomedicine due to their fascinating plasmonic properties as well as their great biocompatibility. An intriguing application is the use of plasmonic photothermal therapy (PPTT) mediated by anisotropic AuNPs irradiated with a near-infrared (NIR) laser for treating ocular diseases in ophthalmology. For this purpose, bipyramidal-shaped AuNPs (BipyAu), which were surface-functionalized with three different organic ligands (citrate, polystyrene sulphonate (PSS), and cetyltrimethylammonium bromide (CTAB)), were synthesized. The long-term storage stability was assured, in terms of minimal variation in aspect ratio and localized surface plasmon resonance. Better performance was achieved with BipyAu@citrate and BipyAu@PSS NPs. PPTT experiments mediated with the synthesized BipyAu NPs demonstrated that BipyAu@citrate provided the highest value of temperature increase (40 °C at 2.0 W cm^-2) after 15 min of 808 nm NIR laser irradiation. The potential future clinical application in ophthalmology was assessed by in vitro cytotoxicity analysis, confirming that BipyAu@citrate NPs were biocompatible for the three major corneal cell types. Furthermore, ex vivo analysis was performed by treating pig corneas with BipyAu@citrate NPs (0.18 μg Au) and subsequent NIR laser irradiation at 808 nm for 15 min, showing distortions in the collagen type I fibrils at the ultrastructural level and promoting the flattening of the corneal surface after treatment, without inducing cell cytotoxicity. This work suggests that a precise control of the fibril distortions can be provoked by PPTT mediated with BipyAu@citrate in the NIR region, paving the way for nanomedicine to correct common deficiencies in corneal diseases.

Nanoparticles capable of dynamically reporting their structural integrity in real-time are a powerful tool to guide the design of drug delivery technologies. Lipid nanoparticles (LNPs) offer multiple important advantages for drug delivery, including stability, protection of active substances, and sustained release capabilities. However, tracking their structural integrity and dynamic behaviour in complex biological environments remains challenging. Here, we report the development of a Förster resonance energy transfer (FRET)-enabled LNP platform that achieves unprecedented sensitivity and precision in monitoring nanoparticle disintegration. The FRET-based LNPs were prepared using nanoprecipitation, encapsulating high levels of 3,3'-dioctadecyloxacarbocyanine perchlorate (DiO) and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) fluorophores as the donor and acceptors, respectively. The resulting LNPs had a mean diameter of 114 ± 19 nm with a distinct FRET signal. An optimal energy transfer efficiency of 0.98 and an emission quantum yield of 0.13 were achieved at 11.1% fluorophore loading in the LNPs, balancing efficient energy transfer and minimal aggregation-induced quenching. Using the FRET reporting, three dissociation stages of FRET LNPs were observed: solvation, indicated by an increased emission intensity; swelling and partial dissolution, evidenced by changes in emission maxima and mean size; and complete dissociation, confirmed by emission solely from DiO and the absence of particles. Testing the nanoparticles in live cells (telomerase-immortalised human corneal epithelial cells, hTCEpi cells) revealed a direct link to the disappearance of the FRET signal with the dissociation of FRET NPs. The nanoparticles initially exhibited a strong extracellular FRET signal, which diminished after cellular internalisation. This suggests that the LNPs disintegrate after entering the cells. These findings establish FRET-based LNPs as a robust tool for real-time nanoparticle tracking, offering insights into their integrity and release mechanisms, with potential applications in advanced drug delivery and diagnostics.

The increasing prevalence of antimicrobial resistance and adverse effects of systemic treatments calls for urgent reevaluation of current methods that rely on excessive, uncontrolled drug administration. In recent years triggerable systems have emerged as promising alternatives, enabling time-controlled and localized drug release, which are only activated if necessary. Light is an obvious candidate as an external trigger, since it allows for localized activation, is non-invasive and its wavelength and intensity can be tailored to fit the demands of the drug release system. Such localized and triggered systems minimize off-target effects and undesired exposure, making it a promising tool for combating health threats such as antimicrobial resistance. However, the limited tissue penetration of visible light significantly limits the applicability of this concept in vivo. Here, we introduce an innovative triggerable drug release system, based on mono-, bi-, and tri-functionalized mesoporous organosilica particles (MOPs). The limited tissue penetration is addressed by an advanced trigger system featuring two-photon absorption. Two-photon absorption enables utilization of near-infrared (NIR) light as a trigger, which is known to exhibit an enhanced penetration depth. The particles are designed to release reactive oxygen species (ROS) upon NIR irradiation and undergo Förster resonance energy transfer (FRET) to a ROS producing dye. Moreover, by oxidative cleavage, an additional therapeutic agent is released in a cascade reaction, enhancing the system's effectiveness. The ROS release is microscopically demonstrated in situ and, for the first time, release of a fluorescent compound (therapeutic agent) in a cascade reaction is observed in real-time, providing valuable insights into the behavior and performance of our particles. This novel sequential dual-release platform for light-triggered therapeutic delivery has great potential for advanced therapeutic applications in both superficial and deep tissue treatments.

Correction for 'Synthesis and photophysical properties of a new push-pull pyrene dye with green-to-far-red emission and its application to human cellular and skin tissue imaging' by Kazuki Inoue et al., J. Mater. Chem. B, 2022, 10, 1641-1649, https://doi.org/10.1039/D1TB02728J.

Targeting the unique characteristics of the tumor microenvironment (TME) has emerged as a highly promising strategy for cancer therapy. Chemodynamic therapy (CDT), which leverages the TME's intrinsic properties to convert H₂O₂ into cytotoxic hydroxyl radicals (˙OH), has attracted significant attention. However, the effectiveness of CDT is often limited by the catalytic efficiency of the materials used. Although Molybdenum disulfide (MoS₂) exhibits remarkable chemodynamic and photothermal properties, its limited efficiency in catalyzing the conversion of endogenous H₂O₂ into ˙OH radicals remains a significant challenge. To overcome this, we developed a nanocomposite of MoS₂ and ruthenium (MoS₂-Ru), by incorporating Ru into MoS₂ nanosheets. The MoS₂-Ru nanocomposite demonstrated significantly enhanced catalytic activity at a low concentration (500 ng mL^-1), whereas the same effect was achieved only with 20 μg mL^-1 of MoS₂. The low Michaelis-Menten constant (K_m) of 4.69 mM further confirmed the superior catalytic activity of the nanocomposite, indicative of the enhanced enzyme-like activity. Additionally, the integration of Ru in MoS₂ reduced the bandgap to 1.18 eV, facilitating near-infrared (NIR) absorption with a high conversion efficiency of 41%. Electron paramagnetic resonance (EPR) analysis confirmed robust ˙OH radical generation driven by the combined chemodynamic and photothermal effects. In vitro studies using triple-negative breast cancer (TNBC) cells validated the synergistic activity of CDT and PTT, demonstrating significant ˙OH radical production under TME conditions, leading to effective cancer cell death. This study underscores the potential of MoS₂-Ru nanocomposites as a versatile and powerful platform for multimodal cancer therapy, seamlessly integrating CDT and PTT to achieve synergistic, precise, and highly effective treatment outcomes.

MXenes are a class of 2D transition metal carbides and nitrides (M_n+1X_nT) that have attracted significant interest owing to their remarkable potential in various fields. The unique combination of their excellent electromagnetic, optical, mechanical, and physical properties have extended their applications to the biological realm as well. In particular, their ultra-thin layered structure holds specific promise for diverse biomedical applications. This comprehensive review explores the synthesis methods of MXene composites, alongside the biological and medical design strategies that have been employed for their surface engineering. This review delves into the interplay between these strategies and the resulting properties, biological activities, and unique effects at the nano-bio-interface. Furthermore, the latest advancements in MXene-based biomaterials and medicine are systematically summarized. Further discussion on MXene composites designed for various applications, including biosensors, antimicrobial agents, bioimaging, tissue engineering, and regenerative medicine, are also provided. Finally, with a focus on translating research results into real-world applications, this review addresses the current challenges and exciting future prospects of MXene composite-based biomaterials.

Platelet-derived microvesicles (PMVs) and their encapsulated microRNAs (miRNAs) hold immense potential as biomarkers for early non-small cell lung cancer (NSCLC) diagnosis. This study presents a pioneering liposome-based approach for enhanced miRNA detection within PMVs, employing a lambda exonuclease (λ EXO)-based amplification system encapsulated in immunoliposomes. The platform exploits the novel catalytic functionality of λ EXO, demonstrating its unprecedented capability to catalyze RNA-DNA hybrid substrates. The λ EXO-based amplification system exhibited high sensitivity and specificity in detecting miRNA-21, a key miRNA associated with NSCLC, demonstrating a limit of detection (LOD) of 33.11 fg mL^-1. The system was successfully encapsulated within liposomes, which were then functionalized with CD41 antibody to facilitate targeted delivery and fusion with PMVs. The results reveal a significant difference in miRNA-21 levels between PMVs from NSCLC patients and healthy individuals, with a 2.06-fold higher abundance observed in NSCLC patients. This research presents a significant technological advancement in miRNA detection, paving the way for improved early diagnosis and personalized medicine approaches.