Antibacterial metal-phenolic nanosheets as smart carriers for the controlled release of epirubicin hydrochloride

Elongated Magnetic Nanorobots with Multi-Enzymatic Cascades for Active In Vivo Tumor Targeting and Enhanced Chemodynamic Therapy

Targeted delivery of therapeutic agents to malignant tissues is crucial for enhancing clinical outcomes and reducing side effects. Magnetic nanorobots (MNRs) present a promising strategy for controlled delivery, leveraging external magnetic fields to achieve precise in vivo targeting. This work develops elongated MNRs comprising linearly arranged magnetic nanoparticles linked by metal-polyphenol complexes (MPCs) for magnetic-field-directed active tumor targeting and synergistic tumor therapy. The MNRs are created by assembling 30 nm Fe3O4 nanoparticles, tannic acid, and ferrous ions (Fe2+) under a uniform magnetic field, resulting in elongated chain-like structures fixed by MPCs, which also promotes peroxidase-like activity. These structures show a greater magnetic response than individual nanoparticles, offering flexibility in magnetic manipulation. The MPCs coating allows tailored surface modifications with glucose oxidase, copper ions (Cu2+), and human serum albumin (HSA), producing colloidally stable MNRs with a built-in multienzymatic cascade (MNRs@GOx/Cu/HSA) that consumes glucose, generates •OH, and depletes the antioxidant glutathione (GSH). Collectively, surface-engineered multifunctional MNRs demonstrate improved in vivo tumor targeting driven by external magnetic fields, leading to efficient localized chemodynamic therapy. The tailored structural and functional properties of the developed MNRs render them suitable for targeted cargo delivery, minimally invasive surgery, and localized treatments in disease sites.

Recent advances of copper-based metal phenolic networks in biomedical applications

Metal-phenolic Networks (MPNs) are a novel class of nanomaterial developed gradually in recent years which are self-assembled by metal ions and polyphenolic ligands. Due to their environmental protection, good adhesion, and biocompatibility with green phenolic ligands, MPNs can be used as a new type of nanomaterial. They show excellent properties such as anti-inflammatory, antioxidant, antibacterial, and anticancer, and have been widely studied in the biomedical field. As one of the most common subclasses of the MPNs family, copper-based MPNs have been widely studied for drug delivery, Photodynamic Therapy (PDT), Chemo dynamic Therapy (CDT), antibacterial and anti-inflammatory, bone tissue regeneration, skin regeneration wound repair, and metal ion imaging. In this paper, the preparation strategies of different types of copper-based MPNs are reviewed. Then, the application status of copper-based MPNs in the biomedical field under different polyphenol ligands is introduced in detail. Finally, the existing problems and challenges of copper-based MPNs are discussed, as well as their future application prospects in the biomedical field.

Intratumoral Microbiota as a Target for Advanced Cancer Therapeutics

In recent years, advancements in microbial sequencing technology have sparked an increasing interest in the bacteria residing within solid tumors and its distribution and functions in various tumors. Intratumoral bacteria critically modulate tumor oncogenesis and development through DNA damage induction, chronic inflammation, epigenetic alterations, and metabolic and immune regulation, while also influencing cancer treatment efficacy by affecting drug metabolism. In response to these discoveries, a variety of anti-cancer therapies targeting these microorganisms have emerged. These approaches encompass oncolytic therapy utilizing tumor-associated bacteria, the design of biomaterials based on intratumoral bacteria, the use of intratumoral bacterial components for drug delivery systems, and comprehensive strategies aimed at the eradication of tumor-promoting bacteria. Herein, this review article summarizes the distribution patterns of bacteria in different solid tumors, examines their impact on tumors, and evaluates current therapeutic strategies centered on tumor-associated bacteria. Furthermore, the challenges and prospects for developing drugs that target these bacterial communities are also explored, promising new directions for cancer treatment.

Green and shape-tunable synthesis of ellagic acid crystalline particles by tannic acid for neuroprotection against oxidative stress

Oxidative stress (OS) plays an important role in the emergence and prevention of neurodegenerative diseases, such as Alzheimer's disease (AD). Excess reactive oxygen species (ROS) accumulated in a neuronal cell can lead to OS, producing cell injury and death. Seeking nanoantioxidants against AD-related oxidative stress has attracted a lot of attention, especially those potential antioxidant agents derived from natural polyphenols. However, the transformation of abundant plant polyphenols to antioxidative biomaterials against OS is still challenging. In this work, we report a new method to transform amorphous tannic acid (TA) into tailorable shaped ellagic acid (EA) crystalline particles without using an organic solvent. EA crystalline particles were generated from TA, which underwent a chemical transformation, in situ metal phenolic coordination and acid-induced assembly process, and the size and shape could be controlled by varying the amount of acid. As-prepared EA crystalline particles showed excellent stability in water and lysosomal mimicking fluid and possess unique fluorescence properties and a strong response in mass spectrometry, which is beneficial for their imaging analysis in cells and tissues. More importantly, EA particles have shown significant H2O2-related ROS scavenging ability, a high cellular uptake capacity, an excellent neuroprotective effect in PC12 cells, a high drug loading capacity and BBB permeability to enter the brain. Our study suggested that the EA crystalline particles show great potential for OS-mediated AD treatment.

Ecofriendly dual-function cotton fabric with antibacterial and anti-adhesion properties based on modified natural materials

Ecofriendly fabrics with antibacterial and anti-adhesion properties have been attracted an increasing attention in recent years. Herein, natural menthol modified polyacrylate (PMCA) antibacterial adhesion agent was synthesized by esterification and polymerisation while natural pterostilbene-grafted-chitosan (PGC) antibacterial agent was prepared through Mannich reaction. The antibacterial and anti-adhesion cotton fabric was fabricated through durable PMCA dip finishing and then layer-by-layer self-assembly of PGC. The results showed that the antibacterial adhesion rates and antibacterial rates of the dual-function cotton fabric against Staphylococcus aureus and Escherichia coli reached up to 99.9 %. Its antibacterial adhesion rates improved by 36.1 % and 40.1 % in comparison with those of cotton fabric treated by menthol alone. Meanwhile against S. aureus, the dual-function cotton fabrics improved the antibacterial rates by 56.7 % and 36.4 %, respectively, from those of chitosan- and pterostilbene-treated fabrics. Against E. coli, the improvements were 89.4 % and 24.8 %, respectively. After 20 household washings, the dual-function cotton fabric maintained >80 % of its original anti-adhesion and antibacterial rates against both species. The dual-function cotton fabric also possessed safe and excellent wearability.

Bi-functional quercetin/copper nanoparticles integrating bactericidal and anti-quorum sensing properties for preventing the formation of biofilms

Biofilms formed by pathogenic bacteria present a persistent risk to human health. While the eradication of matured biofilms remains a formidable challenge, delaying or preventing their formation, which is coordinately regulated by quorum sensing (QS), presents a simpler and more advantageous strategy. Quercetin, a naturally occurring compound with anti-QS properties, has the potential to act as an antibiofilm agent. However, it is plagued by certain inherent drawbacks, including poor water solubility and limited bioavailability. Furthermore, solely blocking QS is not enough to prevent biofilm formation because it lacks bactericidal properties. To address these difficulties, we fabricated bi-functional nanoparticles through the co-assembly of quercetin and copper ions in a facile manner. The resulting quercetin/copper nanoparticles (QC NPs) demonstrated minimal cytotoxicity and hemolysis in vitro. In response to the low pH of microenvironments that were populated by bacterial colonies, the QC NPs underwent disassembly to release copper ions and quercetin. The former exterminated bacteria by disrupting the integrity of the cell membrane, while the latter disrupted the processes involved in QS that are responsible for the biofilm by downregulating the expression of specific genes, effectively preventing the formation of biofilms by both Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. In addition, the QC NPs were integrated into a bacterial cellulose membrane. The composite membrane proved to be highly effective at inhibiting biofilm formation in vitro and demonstrated the ability to reduce inflammatory responses and accelerate the healing of bacteria-infected wounds in vivo. Overall, the bi-functional QC NPs hold great potential for use in addressing the challenges associated with the management of bacterial biofilms.

Drug delivery systems for enhanced tumour treatment by eliminating intra-tumoral bacteria

Cancer remains one of the serious threats to human health. The relationship between bacteria and various tumours has been widely reported in recent years, and studies on intra-tumoral bacteria have become important as intra-tumoral bacteria directly affect the tumorigenesis, progression, immunity and metastatic processes. Therefore, eliminating these commensal intra-tumoral bacteria while treating tumour is expected to be a potential strategy to further enhance the clinical outcome of tumour therapy. Drug delivery systems (DDSs) are widely used to deliver antibiotics and chemotherapeutic drugs for antibacterial and anticancer applications, respectively. Thus, this review firstly provides a comprehensive summary of the association between intra-tumoral bacteria and a host of tumours, followed by a description of advanced DDSs for improving the therapeutic efficacy of cancer treatment through the elimination of intra-tumoral bacteria. It is hoped that this review will provide guidelines for the therapeutic and "synergistic antimicrobial and antitumour" drug delivery strategy.

Biological mechanism of ZnO nanomaterials

Modern nanotechnology has made zinc oxide nanomaterials (ZnO NMts) multifunctional, stable, and low cost, enabling them to be widely used in commercial and biomedical fields. With its wide application, the risk of human direct contact and their release into the environment also increases. This review aims to summarize the toxicity studies of ZnO NMts in vivo, including neurotoxicity, inhalation toxicity, and reproductive toxicity. The antibacterial and antiviral mechanisms of ZnO NMts in vitro and the toxicity to eukaryotic cells were summarized. The summary found that it was mainly related to reactive oxygen species (ROS) produced by oxidative stress. It also discusses the potential harm to body and the favorable prospects of the widespread use of antibacterial and antiviral in the future medical field. The review also emphasizes that the dosage and use method of ZnO NMts will be the focus of future biomedical research.

Stimuli-responsive ultra-small vanadate prodrug nanoparticles with NIR photothermal properties to precisely inhibit Na/K-ATPase for enhanced cancer therapy

Inhibition of Na/K-ATPase is a promising cancer treatment owing to the essential role of Na/K-ATPase in maintaining various cellular functions. The potent Na/K-ATPase inhibitor, vanadate(V) (termed as V(V)), has exhibited efficient anticancer effects. However, nonspecific inhibition using V(V) results in serious side effects, which hinder its clinical application. Here, bovine serum albumin (BSA)-modified ultra-small vanadate prodrug nanoparticles (V(IV) NPs) were synthesized via a combined reduction-coordination strategy with a natural polyphenol tannic acid (TA). A lower systemic toxicity of V(IV) NPs is achieved by strong metal-polyphenol coordination interactions. An efficient V(V) activation is realized by reactive oxygen species (ROS) at the tumor site. Furthermore, V(IV) NPs show excellent photothermal properties in the near-infrared (NIR) region. By NIR irradiation at the tumor site for mild hyperthermia, selective enhancement of the interactions between V(V) and Na/K-ATPase achieves stronger inhibition of Na/K-ATPase for robust cell killing effect. Altogether, V(IV) NPs specifically inhibit Na/K-ATPase in cancer cells with negligible toxicity to normal tissues, thus making them a promising candidate for clinical applications of Na/K-ATPase inhibition.