Surface-engineered vanadium nitride nanosheets for an imaging-guided photothermal/photodynamic platform of cancer treatment

Polymeric functionalization of mesoporous silica nanoparticles: Biomedical insights

Mesoporous silica nanoparticles (MSNs) endowed with polymer coatings present a versatile platform, offering notable advantages such as targeted, pH-controlled, and stimuli-responsive drug delivery. Surface functionalization, particularly through amine and carboxyl modification, enhances their suitability for polymerization, thereby augmenting their versatility and applicability. This review delves into the diverse therapeutic realms benefiting from polymer-coated MSNs, including photodynamic therapy (PDT), photothermal therapy (PTT), chemotherapy, RNA delivery, wound healing, tissue engineering, food packaging, and neurodegenerative disorder treatment. The multifaceted potential of polymer-coated MSNs underscores their significance as a focal point for future research endeavors and clinical applications. A comprehensive analysis of various polymers and biopolymers, such as polydopamine, chitosan, polyethylene glycol, polycaprolactone, alginate, gelatin, albumin, and others, is conducted to elucidate their advantages, benefits, and utilization across biomedical disciplines. Furthermore, this review extends its scope beyond polymerization and biomedical applications to encompass topics such as surface functionalization, chemical modification of MSNs, recent patents in the MSN domain, and the toxicity associated with MSN polymerization. Additionally, a brief discourse on green polymers is also included in review, highlighting their potential for fostering a sustainable future.

Architecture of Vanadium-Based MXene Dysregulating Tumor Redox Homeostasis for Amplified Nanozyme Catalytic/Photothermal Therapy

Taking the significance of the special microenvironment for tumor cell survival into account, disrupting tumor redox homeostasis is highly prospective for improving therapeutic efficacy. Herein, a multifunctional 2D vanadium-based MXene nanoplatform, V4 C3 /atovaquone@bovine albumin (V4 C3 /ATO@BSA, abbreviated as VAB) has been elaborately constructed for ATO-enhanced nanozyme catalytic/photothermal therapy. The redox homeostasis within the tumor cells is eventually disrupted, showing a remarkable anti-tumor effect. The VAB nanoplatform with mixed vanadium valence states can induce a cascade of catalyzed reactions in the tumor microenvironment, generating plenty of reactive oxygen species (ROS) with effective glutathione consumption to amplify oxidative stress. Meanwhile, the stable and strong photothermal effect of VAB under near-infrared irradiation not only causes the necrosis of tumor cells, but also improves its peroxidase-like activity. In addition, the release of ATO can effectively alleviate endogenous oxygen consumption to limit triphosadenine formation and inhibit mitochondrial respiration. As a result, the expression of heat shock proteins is effectively suppressed to overcome thermoresistance and the production of ROS can be further promoted due to mitochondrial injury. Moreover, VAB also presents high photoacoustic and photothermal imaging performances. In brief, the multifunctional nanoplatform can provide ATO-enhanced nanozyme catalytic/photothermal therapy with broadening the biomedical applications of vanadium-based MXene.

Self-Assembled MoS2 Cladding for Corrosion Resistant and Frequency-Modulated Electromagnetic Wave Absorption Materials from X-Band to Ku-Band

Reasonable composition design and controllable structure are effective strategies for harmonic electromagnetic wave (EMW) adsorption of multi-component composites. On this basis, the hybrid MoS2 /CoS2 /VN multilayer structure with the triple heterogeneous interface is prepared by simple stirring hydrothermal, which can satisfy the synergistic interaction between different components and obtain excellent EMW absorption performance. Due to the presence of multiple heterogeneous interfaces, MoS2 /CoS2 /VN composites will produce strong interfacial polarization, while the defects in the sample will become the center of polarization, resulting in dipole polarization. Due to the excellent structural design of MoS2 /CoS2 /VN composite material, MoS2 /CoS2 /VN composite material not only has good conductive loss and polarization loss, but also can maintain excellent stability in simulated seawater, and enhance corrosion resistance. The MoS2 /CoS2 /VN composite with dual functions of corrosion resistant and microwave absorption achieves a minimum reflection loss (RL) of -50.48 dB and an effective absorption bandwidth of up to 5.76 GHz, covering both the X-band and Ku-band. Finally, this study provides a strong reference for the development of EMW absorption materials based on transition metal nitrides.

Porous Molybdenum Nitride Nanosphere as Carrier-Free and Efficient Nitric Oxide Donor for Synergistic Nitric Oxide and Chemo/Sonodynamic Therapy

Given its abundant physiological functions, nitric oxide (NO) has attracted much attention as a cancer therapy. The sensitive release and great supply capacity are significant indicators of NO donors and their performance. Here, a transition metal nitride (TMN) MoN@PEG is adopted as an efficient NO donor. The release process starts with H+-triggered denitrogen owing to the high electronegativity of the N atom and weak Mo-N bond. Then, these active NHx are oxidized by O2 and other reactive oxygen species (ROS) to form NO, endowing specific release to the tumor microenvironment (TME). With a porous nanosphere structure (80 nm), MoN@PEG does not require an extra carrier for NO delivery, contributing to ultrahigh atomic utilization for outstanding release ability (94.1 ± 5.6 μM). In addition, it can also serve as a peroxidase and sonosensitizer for anticancer treatment. To further improve the charge separation, MoN-Pt@PEG was prepared to enhance the sonodynamic therapy (SDT) effect. Accordingly, ultrasound (US) further promotes NO generation due to more ROS generation, facilitating in situ peroxynitrite (·ONOO-) generation with great cytotoxicity. At the same time, the nanostructure also degrades gradually, leading to high elimination (94.6%) via feces and urine within 14-day. The synergistic NO and chemo-/sono-dynamic therapy brings prominent antitumor efficiency and further activates the immune response to inhibit metastasis and recurrence. This work develops a family of NO donors that would further widen the application of NO therapy in other fields.

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.

Liquid exfoliation of V8C7 nanodots as peroxidase-like nanozymes for photothermal-catalytic synergistic antibacterial treatment

Nanozymes are effective antibiotics that use reactive oxygen species (ROS) produced by Fenton/Fenton-like reactions to kill bacteria. However, its activity is still not satisfactory and requires large amounts of hydrogen peroxide (H₂O₂) with side effects on normal tissues. Herein, ultrasmall V₈C₇ nanodots (NDs) are successfully constructed by the liquid-phase exfoliation method for photothermal-catalytic synergistic antibacterial treatment. The prepared V₈C₇ NDs are horseradish peroxidase (HRP)-like nanozymes that can efficiently catalyze H₂O₂ to produce a large amount of ROS. Unlike traditional HRP-like nanozymes, V₈C₇ NDs can have a good catalytic effect under slightly acidic conditions (pH=5.5). Moreover, V₈C₇ NDs have good near-infrared (NIR) absorption and high photothermal conversion efficiency (PTCE, 50.39%), which can be used for photothermal treatment (PTT) of bacteria. In addition, the mild photothermal effect can further enhance the HRP-like catalytic activity of V₈C₇ NDs, thereby further enhancing the antibacterial performance of V₈C₇ NDs. In vitro results show that V₈C₇ NDs can effectively eradicate Escherichia coli (E. coli, gram-negative) and methicillin-resistant Staphylococcus aureus (MRSA, gram-positive) under laser irradiation and the presence of H₂O₂, possessing spectral antibacterial properties. More importantly, V₈C₇ NDs display satisfactory therapeutic effects on wounds infected by MRSA in vivo, and their toxicity is negligible, suggesting that they may have great potential for application as powerful and safe antibacterial agents. This work presents a practical antibacterial strategy by combining PTT and catalytic therapy to achieve efficient treatment of bacteria-infected wounds. STATEMENT OF SIGNIFICANCE: (1) Ultrasmall V₈C₇ NDs were prepared by the liquid-phase exfoliation method. (2) V₈C₇ NDs showed good photothermal, catalytic properties. (3) V₈C₇ NDs achieved satisfactory photothermal-catalytic synergistic antibacterial treatment.

Enhanced ROS-Boosted Phototherapy against Pancreatic Cancer via Nrf2-Mediated Stress-Defense Pathway Suppression and Ferroptosis Induction

In situ oxygen generation is the most common strategy to boost reactive oxygen species (ROS) for enhancing the efficacy of phototherapy in cancer, including photodynamic therapy (PDT) and photothermal therapy (PTT). However, hyperoxidation or hyperthermia often triggers stress-defense pathways and promotes tumor cell survival, thus severely limiting the therapeutic efficacy. To overcome the tumor hypoxia and thermal resistance existing in phototherapy, we constructed a self-synergistic nanoplatform for tumors by incorporating brusatol, a nuclear factor erythroid 2-related factor (Nrf2) inhibitor, into the silica nanonetwork. It was then sequentially decorated with MnO₂ and the photosensitizer chlorin e6 (Ce6) and then coated with poly(ethylene glycol)-folate (PEG-FA)-functionalized polydopamine (PDA) (designated as brusatol/silica@MnO₂/Ce6@PDA-PEG-FA). As an oxygen generator, MnO₂ can promote ROS production, which not only directly enhances Ce6-mediated PDT but also strengthens PDA-mediated PTT by attacking heat shock proteins (HSPs). Particularly, brusatol could efficiently inhibit the activation of Nrf2 defense pathway under hyperoxidation and hyperthermia and cause glutathione peroxidase 4 (GPX4) and ferritin heavy chain (FTH) inactivation, thereby inducing ferroptosis and ultimately enhancing the phototherapeutic effects. By exploiting these features, brusatol/silica@MnO₂/Ce6@PDA-PEG-FA exhibited excellent antitumor efficacy with enhanced PDT and PTT both in in vitro and in vivo studies. Overall, our work highlights a promising strategy against hypoxia- and hyperthermia-associated resistance in phototherapy via suppressing stress-defense system and inducing ferroptosis.

Constructing virus-like SiOx/CeO2/VOx nanozymes for 1064 nm light-triggered mild-temperature photothermal therapy and nanozyme catalytic therapy

The construction of nanoplatforms with combined photothermal properties and cascading enzymatic activities has become an active area of anticancer research. However, the overheating of photothermal therapy (PTT) and the specific properties of tumor microenvironment (TME) greatly impaired the therapeutic efficiency. Herein, we rationally fabricated a virus-like SiO_x/CeO₂/VO_x (SCV) nanoplatform for 1064 nm near-infrared (NIR) triggered mild-temperature PTT and nanozyme catalytic therapy. Firstly, the virus-like shape of SiO_x/CeO₂/VO_x made it favorable for cell adhesion and improved its phagocytosis in cells, and the SCV generated an effective PTT effect upon 1064 nm laser irradiation. Particularly, the produced VO²⁺ in TME could be used as a heat shock protein inhibitor to inhibit the expression of heat shock protein 60 (HSP60) to enhance the PTT efficiency. Moreover, the SCV nanozyme exhibited obvious peroxidase-mimic (POD) catalytic activity, which could generate highly toxic free radical ions (˙OH) under acidic conditions. The mild-temperature heat and ˙OH produced by enzymatic catalysis effectively blocked the tumor growth, as verified firmly by in vitro and in vivo tests. Our designed virus-like SCV nanozyme with POD mimic enzyme activity and a mild photothermal effect may provide a new way of thinking about the combination therapy model.

Ternary Copper Complex of L-Glutamine and Phenanthroline as Counterions of Cyclo-Tetravanadate Anion: Experimental–Theoretical Characterization and Potential Antineoplastic Activity

Over the last decade, therapeutic metallodrugs have become substantially effective in the treatment of cancer. Thus, developing new effective anticancer drugs is a significant research area against the continuing increase in cancers worldwide. In the search for heterobimetallic prodrugs containing V/Cu, a new cyclo-tetravanadate was synthesized and characterized by UV-visible and FTIR spectroscopies and single-crystal X-ray diffraction. L-Glutamine and 1,10-phenanthroline allow the crystallization of [Cu(L-Gln)(phen)(H2O)]4[V4O12]∙8(H2O) (1), in which the cyclo-tetravanadate acts as a free anion. Density functional theory (DFT) calculations were carried out to characterize the frontier molecular orbitals and molecular electrostatic potential. Global reactivity indexes were calculated and analyzed to give insight into the cyclo-tetravanadate anion and complex counterions interactions. Also, using Bader’s theory of atoms in molecules (AIM), non-covalent interactions were analyzed. Docking analysis with the Casiopeina-like complex resulting from the hydrolysis of compound 1 provided insights into these complex potential anticancer activities by interacting with DNA/tRNA via H-bonds and hydrophobic interactions. The release of both components could act together or separately, acting as prodrugs with potential dual antineoplastic activities.

Vanadyl nanocomplexes enhance photothermia-induced cancer immunotherapy to inhibit tumor metastasis and recurrence

Conventional photothermal therapy (PTT) is insufficient to induce a strong and potent anti-tumor immune response. Herein, we present a vanadyl nanocomplex, which simultaneously serves as a photothermal agent (PTA) and an immunogenic cell death (ICD) inducer to enhance the anti-tumor immunity of PTT. The vanadyl nanocomplex (STVN) is constructed via facile one-step coordination assembly under ambient conditions. STVN not only has a strong and stable photothermal effect under near-infrared (NIR) irradiation, but also can cause severe endoplasmic reticulum (ER) stress by itself, leading to ICD and activating the systemic immune responses. In the absence of any adjuvants, NIR-irradiated STVN almost completely ablates primary tumors and simultaneously inhibits distant tumors in mice bearing bilateral melanoma. Meanwhile, the intratumorally injected STVN combined with NIR effectively suppressed melanoma lung metastasis as well as tumor recurrence, displaying that local STVN-mediated PTT could trigger a systemic anti-tumor immunity. Therefore, STVN, as a novel immunogenicity-enhanced PTA, affords a "one stone two birds" strategy for improved photothermia-induced cancer immunotherapy.

Recent Progress of Lung Cancer Diagnosis Using Nanomaterials

Lung cancer is one of the serious malignant tumors with high morbidity and mortality due to the poor diagnosis and early metastasis. The developing nanotechnology provides novel concepts and research strategies for the lung cancer diagnosis by employing nanomaterials as diagnostic reagents to enhance diagnostic efficiency. This commentary introduces recent progress using nanoparticles for lung cancer diagnosis from two aspects of in vivo and in vitro detection. The challenges and future research perspectives are proposed at the end of the paper.

Vanadium-based nanomaterials for cancer diagnosis and treatment

In the past few decades, various vanadium compounds have displayed potential in cancer treatment. However, fast clearness in the body and possible toxicity of vanadium compounds has hindered their further development. Vanadium-based nanomaterials not only overcome these limitations, but take advantage of the internal properties of vanadium in photics and magnetics, which enable them as a multimodal platform for cancer diagnosis and treatment. In this paper, we first introduced the basic biological and pharmacological functions of vanadium compounds in treating cancer. Then, the synthesis routes of three vanadium-based nanomaterials were discussed, including vanadium oxides, 2D vanadium sulfides, carbides and nitrides: V_mX_n (X = S, C, N) and water-insoluble vanadium salts. Finally, we highlighted the applications of these vanadium-based nanomaterials as tumor therapeutic and diagnostic agents.

Performance evaluation of a low-cost, novel vanadium nitride xerogel (VNXG) as a platinum-free electrocatalyst for dye-sensitized solar cells

A vanadium nitride xerogel (VNXG) was synthesised by a simple and effective method of ammonialising a vanadium pentoxide xerogel at a higher temperature. Xerogel-structured materials possess salient features such as high surface area, tunable porosity and pore size that result in enhancing the catalytic activity by a fast electron-transport pathway and increase electrolyte diffusion channels. Metal nitrides are reported as promising alternate low-cost counter electrodes to replace the conventional and expensive platinum (Pt) counter electrode. Though few studies are reported on aerogel-based CEs for DSSCs, the present work is the first attempt to synthesize and evaluate the performance of xerogel-structured metal nitrides as counter electrode materials for dye-sensitized solar cells. The synthesized material was well characterized for its structural and morphological characteristics and chemical constituents by photoelectron spectroscopy. Finally, the VNXG was tested for its electrocatalytic performance as a choice of counter electrodes for dye-sensitized solar cells (DSSCs). The photo-current studies were performed under standard 1 SUN, class AAA-simulated illumination with AM1.5G. The consolidated results revealed that the vanadium nitride xerogel exhibited good photocatalytic activity and low charge transfer resistance. This identified it as a promising low-cost counter electrode (CE) material for dye-sensitized solar cells. The photo-current conversion efficiency of the vanadium nitride xerogel CE-based DSSC reached 5.94% comparable to that of the conventional thermal decomposed Pt CE-based DSSC, 7.38% with the same iodide/triiodide electrolyte system. Moreover, the 28 days stability study of VNXG CE DSSCs provided an appreciably stable performance with 37% decrement in the PCE under the same test condition.

Chitosan derived glycolipid nanoparticles for magnetic resonance imaging guided photodynamic therapy of cancer

Currently, the development of polysaccharide, especially chitosan (CS), based drug delivery system to afford magnetic resonance imaging (MRI) guided theranostic cancer therapy remains largely unexplored. Herein, we successfully developed a CS derived polymer (Gd-CS-OA) through chemical conjugation of CS, octadecanoic acid (OA) and gadopentetic acid (GA). After self-assemble into glycolipid nanoparticles to loaded chlorin e6 (Ce6), the resulted Gd-CS-OA/Ce6 was able to realize MRI guided photodynamic therapy (PDT) of cancer. Our results revealed that Gd-CS-OA was able to increase the MRI sensitivity as compared to Gd-DTPA with decent residence time and preferable excretion behavior in vivo. Moreover, the Gd-CS-OA/Ce6 showed negligible hemolysis, satisfactory ROS generation and stability in physiological environments with preferable cellular uptake and enhanced in vitro cytotoxicity (through elevated ROS generation) on 4T1 cells. Most importantly, Gd-CS-OA/Ce6 demonstrated promising in vivo tumor targetability (enhanced penetration and retention effect) and powerful MRI guided tumor ablation through PDT on in situ 4T1 tumor model.

Co2.67S4-Based Photothermal Membrane with High Mechanical Properties for Efficient Solar Water Evaporation and Photothermal Antibacterial Applications

The lack of freshwater resources, or the freshwater crisis, is an important issue in the resource field. One potential green and sustainable method to solve this problem is to implement solar energy-driven water evaporation to collect freshwater. Capitalizing on the low cost, high production yield, and simplified fabrication process properties of nonstoichiometric Co_2.67S₄ nanoparticles, we strategically designed and synthesized a Co_2.67S₄-deposited Teflon (PTFE) membrane for realizing efficient solar water evaporation and photothermal antibacterial properties under light irradiation. Compared with previously reported cellulose acetate and poly(vinylidene fluoride) membranes, the PTFE membrane displayed significantly enhanced mechanical properties. Additionally, a Co_2.67S₄-deposited PTFE membrane with a hydrophobic treatment (termed as the Final-PTFE membrane) exhibited excellent durability. The light-to-heat conversion efficiency (η) of water evaporation reached a value of 82% for our as-prepared Final-PTFE membrane under two sun irradiation conditions. Moreover, the antibacterial mechanism observed by scanning electron microscopy was attributed to the thermal effect, which damaged the cell wall of bacteria. Our work highlights the great potentials of the Final-PTFE membrane as a versatile system for implementing solar energy-driven photothermal water evaporation and water purification.

The controllable growth of ultrathin MnO2 on polydopamine nanospheres as a single nanoplatform for the MRI-guided synergistic therapy of tumors

The integration of two-dimensional (2D) nanosheets with biocompatible photothermal nanoparticles may produce effective multifunctional nanotheranostic agents.