APTES-mediated Cu2(OH)3(NO3) nanomaterials on the surface of silicone catheters for abscess.

Metal-based nanomaterials have remarkable bactericidal effects; however, their toxicity cannot be disregarded. To address this concern, we developed a simple synthesis route for antibacterial catheters using metal-based nanomaterials to reduce toxicity while harnessing their excellent bactericidal properties. The grafting agent (3-aminopropyl)triethoxysilane (APTES) forms -NH2 groups on the catheter surface, onto which copper ions form a nanomaterial complex known as Cu2(OH)3(NO3) (defined as SA-Cu). The synthesized SA-Cu exhibited outstanding contact antibacterial effects, as observed through scanning electron microscopy (SEM), which revealed cell membrane crumbing and bacterial rupture on the catheter surface. Furthermore, SA-Cu exhibited excellent biosafety characteristics, as evidenced by the cell counting kit-8 (CCK-8) assay, which showed no significant cytotoxicity. SA-Cu demonstrated sustained antimicrobial capacity, with in vivo experiments demonstrating over 99% bactericidal efficacy against methicillin-resistant Staphylococcus aureus (MRSA) for two weeks. The transcriptome sequencing results suggested that SA-Cu may exert its bactericidal effects by interfering with histidine and purine metabolism in MRSA. This study presents a straightforward method for synthesizing antimicrobial silicone catheters containing copper nanomaterials using copper ions.

Recent advances on nanomaterials for antibacterial treatment of oral diseases.

An imbalance of bacteria in oral environment can lead to a variety of oral diseases, such as periodontal disease, dental caries, and peri-implant inflammation. In the long term, in view of the increasing bacterial resistance, finding suitable alternatives to traditional antibacterial methods is an important research today. With the development of nanotechnology, antibacterial agents based on nanomaterials have attracted much attention in dental field due to their low cost, stable structures, excellent antibacterial properties and broad antibacterial spectrum. Multifunctional nanomaterials can break through the limitations of single therapy and have the functions of remineralization and osteogenesis on the basis of antibacterial, which has made significant progress in the long-term prevention and treatment of oral diseases. In this review, we have summarized the applications of metal and their oxides, organic and composite nanomaterials in oral field in recent five years. These nanomaterials can not only inactivate oral bacteria, but also achieve more efficient treatment and prevention of oral diseases by improving the properties of the materials themselves, enhancing the precision of targeted delivery of drugs and imparting richer functions. Finally, future challenges and untapped potential are elaborated to demonstrate the future prospects of antibacterial nanomaterials in oral field.

Phototherapy Using a Fluoroquinolone Antibiotic Drug to Suppress Tumor Migration and Proliferation and to Enhance Apoptosis.

In this work, a fluoroquinolone antibiotic drug (sparfloxacin (SP)) was selected as a chemotherapy drug and photosensitizer for combined therapy. A facile chemical process was developed to incorporate SP and upconversion nanoparticles (UCNPs) into the thermally sensitive amphiphilic polymer polyethylene glycol-poly(2-hexoxy-2-oxo-1,3,2-dioxaphospholane). In vitro and in vivo experiments showed that 60% of the SP molecules can be released from the micelles of thermal-sensitive polymers using a 1 W cm-2 980 nm laser, and this successfully inhibits cell migration and metastasis by inhibiting type II topoisomerases in nuclei. Additionally, intracellular metal ions were chelated by SP to induce cancer cell apoptosis by decreasing the activity of superoxide dismutase and catalase. In particular, the fluoroquinolone molecules produced singlet oxygen (1O2) to kill cancer cells, and this was triggered by UCNPs when irradiation was performed with a 980 nm laser. Overall, SP retained a weak chemotherapeutic effect, achieved enhanced photosensitizer-like effects, and was able to repurpose old drugs to elevate the therapeutic efficacy against cancer, increase the specificity for suppressing tumor migration and proliferation, and enhance apoptosis.

Immunogenic Cell Death Augmented by Manganese Zinc Sulfide Nanoparticles for Metastatic Melanoma Immunotherapy.

Both T-cell deprivation and insufficient tumor immunogenicity seriously hinder the efficacy of immune-mediated tumor destruction in melanoma. In this work, an amphiphilic polyethylene glycol-poly(2-hexoxy-2-oxo-1,3,2-dioxaphospholane) copolymer with a thermally sensitive flowable core (mPEG-b-PHEP) was chosen to incorporate IR780 dye and manganese zinc sulfide nanoparticles (ZMS) to form polymer micelles (denoted PPIR780-ZMS), which precisely controlled the release of ZMS after being triggered by near-infrared light (NIR). Mn2+-mediated chemodynamic therapy (CDT) by photothermal trigger boosted the generation of reactive oxygen species (ROS), making the PPIR780-ZMS smart bomblets in vivo. It was demonstrated that PPIR780-ZMS could maximize immunogenic cell death (ICD) in cancer, which is characterized by abundant damage-associated molecular pattern (DAMP) exposure. As a result, the cytotoxic T cells (CD8+) and helper T cells (CD4+) expanded and infiltrated the neoplastic foci, which further reprogrammed the suppressive tumor microenvironment (TME) against the primary tumor and pulmonary metastases with safe systemic cytokine expression. In addition, Mn2+-mediated cGAS-STING signaling pathway activation enhanced the antitumor immunity of this nanocomposite, providing a practical strategy for expanding the use of Mn-based nanostructures.