Selenium Vacancy Engineering Using Bi2Se3 Nanodots for Boosting Highly Efficient Photonic Hyperthermia

The Role of Inorganic Nanomaterials in Overcoming Challenges in Colorectal Cancer Diagnosis and Therapy

Colorectal cancer poses a significant threat to human health due to its high aggressiveness and poor prognosis. Key factors impacting patient outcomes include post-surgical recurrence, chemotherapeutic drug resistance, and insensitivity to immunotherapy. Consequently, early diagnosis and the development of effective targeted therapies are essential for improving prevention and treatment strategies. Inorganic nanomaterials have gained prominence in the diagnosis and treatment of colorectal cancer owing to their unique size, advantageous properties, and high modifiability. Various types of inorganic nanomaterials-such as metal-based, metal oxide, quantum dots, magnetic nanoparticles, carbon-based, and rare-earth nanomaterials-have demonstrated significant potential in enhancing multimodal imaging, drug delivery, and synergistic therapies. These advancements underscore their critical role in improving therapeutic outcomes. This review highlights the properties and development of inorganic nanomaterials, summarizes their recent applications and progress in colorectal cancer diagnosis and treatment, and discusses the challenges in translating these materials into clinical use. It aims to provide valuable insights for future research and the clinical application of inorganic nanomaterials in colorectal cancer management.

Engineering H2O2 Self-Supplying Platform for Xdynamic Therapies via Ru-Cu Peroxide Nanocarrier: Tumor Microenvironment-Mediated Synergistic Therapy

Of the most common, hypoxia, overexpressed glutathione (GSH), and insufficient H2O2 concentration in the tumor microenvironment (TME) are the main barriers to the advancment of reactive oxygen species (ROS) mediated Xdynamic therapies (X = photo, chemodynamic, chemo). Maximizing Fenton catalytic efficiency is crucial in chemodynamic therapy (CDT), yet endogenous H2O2 levels are not sufficient to attain better anticancer efficacy. Specifically, there is a need to amplify Fenton reactivity within tumors, leveraging the unique attributes of the TME. Herein, for the first time, we design RuxCu1-xO2-Ce6/CPT (RCpCCPT) anticancer nanoagent for TME-mediated synergistic therapy based on heterogeneous Ru-Cu peroxide nanodots (RuxCu1-xO2 NDs) and chlorine e6 (Ce6), loaded with ROS-responsive thioketal (TK) linked-camptothecin (CPT). The Ru-Cu peroxide NDs (RCp NDs, x = 0.50) possess the highest oxygen vacancy (OV) density, which grants them the potential to form massive Lewis's acid sites for peroxide adsorption, while the dispersibility and targetability of the NDs were improved via surface modification using hyaluronic acid (HA). In TME, RCpCCPT degrades, releasing H2O2, Ru2+/3+, and Cu+/2+ ions, which cooperatively facilitate hydroxyl radical (•OH) formation and deactivate antioxidant GSH enzymes through a cocatalytic loop, resulting in excellent tumor therapeutic efficacy. Furthermore, when combined with laser treatment, RCpCCPT produces singlet oxygen (1O2) for PDT, which induces cell apoptosis at tumor sites. Following ROS generation, the TK linkage is disrupted, releasing up to 92% of the CPT within 48 h. In vitro investigations showed that laser-treated RCpCCPT caused 81.5% cell death from PDT/CDT and chemotherapy (CT). RCpCCPT in cancer cells produces red-blue emission in images of cells taking them in, which allows for fluorescence image-guided Xdynamic treatment. The overall results show that RCp NDs and RCpCCPT are more biocompatible and have excellent Xdynamic therapeutic effectiveness in vitro and in vivo.

Multifunctional two-dimensional Bi2Se3 nanodiscs for anti-inflammatory therapy of inflammatory bowel diseases

The overexpression of reactive oxygen and nitrogen species (RONS) in the colonic mucosa destroys the mucosa and its barrier, accelerating the occurrence of inflammatory bowel disease (IBD). The elimination of RONS from the inflammatory colon has proven effective in alleviating IBD. Although many nanoantioxidants have been developed, preparing robust and efficient nano-antioxidants remains challenging. Herein, by modifying bismuth selenide (Bi₂Se₃) nanodiscs with polyvinylpyrrolidone (PVP), a multifunctional nanozyme based on 2D nanomaterials was developed for the treatment of IBD. By eliminating multiple RONS, such as hydroxyl radicals (•OH), superoxide anions (O₂^-•), nitric oxide (NO), and Bi₂Se₃ nanodiscs enhanced cellular survival after H₂O₂ stimulation. As evidenced by colonic injury, reduced body weight, spleen index, and proinflammatory cytokine levels in mice, RONS clearance alleviated intestinal inflammation in a prevention and delay model of acute colitis. 16S rDNA amplicon sequencing reveals that Bi₂Se₃ nanodiscs had the potential to regulate intestinal flora, increase the proportion of Firmicutes to Bacteroidetes, inhibit Proteobacteria bacteria, and restore intestinal homeostasis. This study highlights the use of Bi₂Se₃ nanodiscs with excellent biocompatibility, multienzyme functionality, and RONS scavenging ability as treatments for IBD without apparent adverse effects. STATEMENT OF SIGNIFICANCE: RONS were efficiently scavenged by Bi₂Se₃ nanodiscs. Bi₂Se₃ nanodiscs could be as a promising and potentially safe theraeputic agent for IBD. The gut microbiota could be modulated by Bi₂Se₃ nanodiscs.

Metal selenide nanomaterials for biomedical applications

Metal selenide nanomaterials have received enormous attention as they possess diverse compositions, microstructures, and properties. The combination of selenium with various metallic elements gives the metal selenide nanomaterials distinctive optoelectronic and magnetic properties, such as strong near-infrared absorption, excellent imaging properties, good stability, and long in vivo circulation. This makes metal selenide nanomaterials advantageous and promising for biomedical applications. This paper summarizes the research progress in the last five years in the controlled synthesis of metal selenide nanomaterials in different dimensions and with different compositions and structures. Then we discuss how surface modification and functionalization strategies are well-suited for biomedical fields, including tumor therapy, biosensing, and antibacterial biological applications. The future trends and issues of metal selenide nanomaterials in the biomedical field are also discussed.

Advances in Single-component inorganic nanostructures for photoacoustic imaging guided photothermal therapy

Phototheranostic based on photothermal therapy (PTT) and photoacoustic imaging (PAI), as one of avant-garde medical techniques, have sparked growing attention because it allows noninvasive, deeply penetrative, and highly selective and effective therapy. Among a variety of phototheranostic nanoagents, single-component inorganic nanostructures are found to be novel and attractive PAI and PTT combined nanotheranostic agents and received tremendous attention, which not only exhibit structural controllability, high tunability in physiochemical properties, size-dependent optical properties, high reproducibility, simple composition, easy functionalization, and simple synthesis process, but also can be endowed with multiple therapeutic and imaging functions, realizing the superior therapy result along with bringing less foreign materials into body, reducing systemic side effects and improving the bioavailability. In this review, according to their synthetic components, conventional single-component inorganic nanostructures are divided into metallic nanostructures, metal dichalcogenides, metal oxides, carbon based nanostructures, upconversion nanoparticles (UCNPs), metal organic frameworks (MOFs), MXenes, graphdiyne and other nanostructures. On the basis of this category, their detailed applications in PAI guide PTT of tumor treatment are systematically reviewed, including synthesis strategies, corresponding performances, and cancer diagnosis and therapeutic efficacy. Before these, the factors to influence on photothermal effect and the principle of in vivo PAI are briefly presented. Finally, we also comprehensively and thoroughly discussed the limitation, potential barriers, future perspectives for research and clinical translation of this single-component inorganic nanoagent in biomedical therapeutics.

Vacancy defect-promoted nanomaterials for efficient phototherapy and phototherapy-based multimodal Synergistic Therapy

Phototherapy and multimodal synergistic phototherapy (including synergistic photothermal and photodynamic therapy as well as combined phototherapy and other therapies) are promising to achieve accurate diagnosis and efficient treatment for tumor, providing a novel opportunity to overcome cancer. Notably, various nanomaterials have made significant contributions to phototherapy through both improving therapeutic efficiency and reducing side effects. The most key factor affecting the performance of phototherapeutic nanomaterials is their microstructure which in principle determines their physicochemical properties and the resulting phototherapeutic efficiency. Vacancy defects ubiquitously existing in phototherapeutic nanomaterials have a great influence on their microstructure, and constructing and regulating vacancy defect in phototherapeutic nanomaterials is an essential and effective strategy for modulating their microstructure and improving their phototherapeutic efficacy. Thus, this inspires growing research interest in vacancy engineering strategies and vacancy-engineered nanomaterials for phototherapy. In this review, we summarize the understanding, construction, and application of vacancy defects in phototherapeutic nanomaterials. Starting from the perspective of defect chemistry and engineering, we also review the types, structural features, and properties of vacancy defects in phototherapeutic nanomaterials. Finally, we focus on the representative vacancy defective nanomaterials recently developed through vacancy engineering for phototherapy, and discuss the significant influence and role of vacancy defects on phototherapy and multimodal synergistic phototherapy. Therefore, we sincerely hope that this review can provide a profound understanding and inspiration for the design of advanced phototherapeutic nanomaterials, and significantly promote the development of the efficient therapies against tumor.