Journal of materials chemistry. B最新文献

Self-assembling phage-inspired carriers based on macrocyclic molecules have the potential to overcome antibiotic resistance and extend the antimicrobial effect of drugs. In this study, we have synthesized a new water-soluble pillar[5]arene containing thioglycoside fragments. This compound had an affinity for a model lipid membrane, underwent self-assembly, and associated with the fluoroquinolone antibiotic ciprofloxacin hydrochloride (Cipro) to form biocompatible supramolecular nanostructures. UV-vis and fluorescence spectroscopies were used to assess the ability of the pillar[5]arene/antibiotic system to form supramolecular complexes in a 1 : 2 stoichiometry (lg K_1 : 1 = 1.49 and lg K_1 : 2 = 4.22). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) studies confirmed the formation of stable pillararene/antibacterial complexes with particle sizes in the range of 250-300 nanometers. And the biological characteristics of the systems we obtained indicate their low toxicity to cancer (A549) and normal cells (LEK and HSF), with a twofold increase in the inhibitory effect of the combined pillar[5]arene/antibiotic system on the strain of K. pneumoniae with increased resistance to ciprofloxacin. The improved antibacterial properties of the antibiotic in combination with the pillar[5]arene may be due to the blocking of efflux pumps, which is confirmed by molecular docking.

Correction for 'Surface nanocrystallization enhances the biomedical performance of additively manufactured stainless steel' by Sumit Ghosh et al., J. Mater. Chem. B, 2023, 11, 9697-9711, https://doi.org/10.1039/D3TB01534C.

Waterborne bacterial contamination remains a pressing global health concern, demanding point-of-care (POC) devices for rapid and efficient on-site detection. High costs, long processing times and reliance on sophisticated equipment limit conventional methods. Thus, this study proposes the fabrication of a low-cost, disposable paper-based electrochemical biosensor for the effective and selective detection of Gram-negative bacteria. The developed biosensor was modified with a g-C₃N₄/amine-functionalised carbon dot composite to boost signal transduction and offer stable immobilisation of a TLR-4/MD-2 bioreceptor, which detects explicitly the lipopolysaccharide layer of Gram-negative bacterial samples. The developed paper-based biosensor showed excellent analytical performance with remarkable specificity and achieved a low theoretical limit of detection of 0.66 CFU mL^-1 and 0.88 CFU mL^-1 for E. coli and P. aeruginosa, respectively, across a wide dynamic range of 1.5 to 1.5 × 10⁵ CFU mL^-1. Furthermore, the biosensor demonstrated good stability, reproducibility and ability to attain a satisfactory low LOD in the spiked tap and pond water samples. Moreover, the simple disposability of the paper electrodes lowers the cross-contamination issues and ensures the safety of the environment. Collectively, this work introduces a sustainable, low-cost, and portable biosensing platform that effectively integrates a nanomaterial for enhanced transduction with receptor-based specificity, offering significant potential for early diagnosis of waterborne bacterial contamination and advancing public health protection through POC applications.

Photocleavable protective groups (PPGs) offer a straightforward method of temporarily masking the aggressive functions of organic compounds and inactivating biologically active or toxic substrates. The active species can then be released from their photoactivatable precursors in a controlled manner upon exposure to light. In this study, we present a series of photocages based on the novel fluorescent scaffold 2-aryl-2H-1,2,3-triazol-4-yl-thiazoles (ATTs), incorporating proteinogenic amino acids, the biologically active compound biotin, the anticancer agent melphalan, and model compounds such as aromatic acids. Studies of photodegradation under various conditions using mass spectrometry, spectral and kinetic analyses, and quantum mechanical calculations have shown that acid release from the photoconjugates (ATT-PCs) depends on fluorophore fragment structure, acid nature, and the presence of air, water or a phosphate buffer solution (pH of 7.4), as well as the light source power and λ_ir. The release of acid during photodissociation was confirmed through high-resolution mass spectrometry and biological experiments, including the MTT assay and the imaging of Vero cells incubated with ATT-PCs, utilising a confocal scanning microscope. The photorelease mechanism was explored using both experimental studies and quantum mechanical calculations, which revealed that the properties and reactivity of this photosystem are predominantly influenced by the transition to the triplet state. Additionally, the findings indicated that ATT-PCs effectively absorb light in the visible spectrum and exhibit intense fluorescence, even in a DMSO-PBS mixture at a 1 : 9 ratio. Furthermore, ATT-PCs can function as photosensitisers, capable of generating reactive oxygen species (ROS). Cell studies demonstrate the rapid intracellular uptake of ATT-PCs by Vero cells, with accumulation in the endoplasmic reticulum (ER) or lipid droplets within a 0.5-hour incubation period.

Targeted modulation of enzyme activity offers a promising strategy for both elucidating catalytic mechanisms and developing novel therapeutics. In this study Zn²⁺ ions were introduced as an effective competitive inhibitor of fumarase, a pivotal enzyme in the citric acid cycle. Zn²⁺ binding significantly alters the Michaelis constant (K_m) for both L-malate and fumarate, with a pronounced preference for inhibiting the reverse reaction (L-malate to fumarate), a direction relevant to redox homeostasis and anaplerotic flux. A major limitation of the clinical application of many metal-based inhibitors is their poor water solubility. To overcome this challenge and introduce a new class of enzyme inhibitors, zinc-modified carbon quantum dots (Zn-CQDs) were synthesized. Owing to their polar surface, Zn-CQDs interact more effectively with the enzyme, which increases the local concentration of Zn²⁺ ions at the active site. As a result, these nanomaterials exhibit enhanced water solubility and significantly greater inhibitory potency compared to free Zn²⁺ ions. Biophysical and kinetic analyses confirmed the competitive inhibition mechanism and demonstrated that Zn-CQDs interact with the enzyme without perturbing its secondary structure. Notably, both Zn²⁺ ions and Zn-CQDs preferentially inhibited the reverse reaction of fumarase, offering precise control over fumarase activity. Molecular docking and MD simulations elucidated the plausible binding site of Zn²⁺ within the active site. It was found that Zn²⁺ interacts with Glu340, a residue previously shown to be involved in binding fumarase inhibitors. These findings establish Zn-CQDs as a novel class of water-soluble fumarase inhibitors, distinguished by their facile synthesis, tunable solubility, and selective inhibition profile. This work highlights the potential of zinc-based nanomaterials in enzyme regulation, offering a powerful alternative to existing inhibitors and developing targeted redox-sensitive therapeutic strategies.

Heart disease has become a major threat to global health. In recent years, extracellular vesicles (EVs) have become a research hotspot in heart regeneration and repair due to their unique intercellular communication function and advantages in cell-free therapy. This paper systematically summarizes the sources, characteristics, engineering, and clinical applications of EVs in heart regeneration. Cardiac therapy-related EVs significantly reduce cardiac fibrosis, regulate inflammation and immunity, improve the myocardial microenvironment, and promote angiogenesis by delivering biologically active molecules such as proteins, lipids, and microRNAs. In addition, bioengineering techniques (such as targeted peptide modification and hydrogel delivery systems) have further improved the cardiac targeting and long-lasting efficacy of specific EVs. The above methods have shown high repair potential in disease models such as cardiac ischemia-reperfusion injury, myocardial infarction, heart failure, and structural heart diseases. However, the clinical application of EVs still faces some challenges that need to be urgently addressed. Future research needs to focus on standardized and scaled production processes, long-lasting storage capacity, and precise and specific mechanisms of action of EVs to facilitate the translation of EVs from basic research to the clinic.

Oral squamous cell carcinoma (OSCC) remains a challenging malignancy with high recurrence and metastasis rates, often limited by insufficient immunogenicity and a suppressive tumor microenvironment. Immunogenic cell death (ICD) offers a promising approach to convert cell death into antitumor immunity; yet, its efficacy depends on precise modulation of autophagy and endoplasmic reticulum stress (ERS). Here, we report that combining the BET inhibitor JQ1 with the autophagy inhibitor chloroquine (CQ) synergistically amplifies ERS, leading to enhanced ICD in OSCC models. This combination promotes robust damage-associated molecular pattern (DAMP) release, dendritic cell activation, and antigen-specific CD8⁺ T-cell responses. To enable localized and efficient delivery, we engineered self-assembled JQ1/CQ nanoparticles stabilized through π-π stacking and integrated them into dissolvable cryomicroneedles. This minimally invasive platform ensures sustained drug release, improves tumor accumulation, and minimizes systemic exposure. Our study not only elucidates a druggable autophagy-ERS-ICD axis but also provides a versatile transdermal delivery strategy with potential applicability to a range of solid tumors.

Enamel, the hardest and most mineralised tissue of the human body, serves as the outer barrier of teeth and protects them from mechanical and chemical damage. Its structural integrity relies on a delicate balance between demineralisation and remineralisation. Disruption of this equilibrium leads to dental caries, one of the most prevalent oral diseases worldwide. Remineralisation strategies, therefore, aim to restore mineral content and reinforce enamel resistance. Reliable characterisation of remineralisation is essential to assess treatment efficacy and guide the design of innovative biomaterials. This review provides a comprehensive overview of the methodologies available to evaluate enamel repair, encompassing surface morphology, mechanical performance, chemical composition and mineral density and crystallinity. For each category, the principles, advantages and limitations of the main techniques are critically discussed, with emphasis on their relevance to translational and clinical applications. By integrating insights from these complementary approaches, this work proposes a framework to select appropriate characterisation methods and highlights the importance of combining them to achieve a robust evaluation of enamel remineralisation. Such knowledge is key to advancing the development of novel materials and strategies for durable enamel restoration.

Photodynamic therapy (PDT) stands out as a promising alternative for cancer treatment due to its low invasiveness and low side effects. Additionally, photosensitizers often exhibit photoluminescent properties, which provide valuable diagnostic guidance for preoperative planning and drug delivery. However, current assessment of therapeutic efficacy largely relies on auxiliary imaging techniques to track tumor volume changes, which fail to provide real-time feedback on treatment outcomes. In this study, a DNA-specific dual-emissive photosensitizer, TPBT, was identified for photodynamic theranostics with red fluorescence serving for preoperative guidance and green fluorescence enabling real-time therapeutic evaluation. Notably, TPBT can behave as a cell-membrane permeable dye to stain the nuclei of early apoptosis cells. Moreover, TPBT exhibits a unique "light-induced emission enhancement" phenomenon, where its green fluorescence intensity is amplified by approximately three-fold under light exposure, enabling more accurate signal reporting and reducing photobleaching. The dual-emissive TPBT integrates diagnostic imaging, personalized treatment, and real-time therapeutic monitoring into a single molecule, offering an innovative strategy for developing efficient and precise theranostic systems.

Functional 1,8-naphthalimide derivatives are rapidly developing in the field of anticancer research. However, the unpredictable side effects of 1,8-naphthalimide derivatives limit their transition from clinical trials to clinical drugs. To decrease the overall cytotoxicity of 1,8-naphthalimide derivatives after coordination with metals, we have synthesized and characterized three new rare earth naphthalene dicarboxylate complexes with the general molecular formula of [Ln(TTA)₃NI-Phen], where Ln = Er, Nd, and Yb, TTA = thenoyltrifluoroacetone, and NI-Phen = 2-(1,10-phenanthrolin-5-yl)-1H-benzo[de]isoquinoline-1,3(2H)-dione. In vitro antitumor screening revealed that all three complexes exhibit better inhibitory activities against A549 and H1299 cancer cell lines compared with the commercial anticancer drug cisplatin. Especially, Er(TTA)₃NI-Phen exhibited specific cytotoxicity to H1299 cancer cells in micromole magnitude and lower toxicity to normal human cells, Beas-2b. Interestingly, Er(TTA)₃NI-Phen triggers lung cancer cell apoptosis via a mitochondrial dysfunction pathway, which is caused by dysfunction of mitochondria and cell cycle arrest. Most importantly, Er(TTA)₃NI-Phen demonstrates an inhibition rate of up to 84% against H1299 tumors.