Folin-Ciocalteu Assay Inspired Polyoxometalate Nanoclusters as a Renal Clearable Agent for Non-Inflammatory Photothermal Cancer Therapy

From hemostasis to proliferation: Accelerating the infected wound healing through a comprehensive repair strategy based on GA/OKGM hydrogel loaded with MXene@TiO2 nanosheets

The treatment of infected wounds poses a formidable challenge in clinical practice due to the detrimental effects of uncontrolled bacterial infection and excessive oxidative stress, resulting in prolonged inflammation and impaired wound healing. In this study, we presented a MXene@TiO2 (MT) nanosheets loaded composite hydrogel named as GA/OKGM/MT hydrogel, which was formed based on the Schiff base reaction between adipic dihydrazide modified gelatin (GA)and Oxidized Konjac Glucomannan (OKGM), as the wound dressing. During the hemostasis phase, the GA/OKGM/MT hydrogel demonstrated effective adherence to the skin, facilitating rapid hemostasis. In the subsequent inflammation phase, the GA/OKGM/MT hydrogel effectively eradicated bacteria through MXene@TiO2-induced photothermal therapy (PTT) and eliminated excessive reactive oxygen species (ROS), thereby facilitating the transition from the inflammation phase to the proliferation phase. During the proliferation phase, the combined application of GA/OKGM/MT hydrogel with electrical stimulation (ES) promoted fibroblast proliferation and migration, leading to accelerated collagen deposition and angiogenesis at the wound site. Overall, the comprehensive repair strategy based on the GA/OKGM/MT hydrogel demonstrated both safety and reliability. It expedited the progression through the hemostasis, inflammation, and proliferation phases of wound healing, showcasing significant potential for the treatment of infected wounds.

Multifunctional Two-Dimensional Bi2Se3 nanodisks as a Non-Inflammatory photothermal agent for glioma treatment

Photothermal therapy (PTT) has gained widespread attention due to its significant advantages, such as noninvasiveness and ability to perform laser localization. However, PTT usually reaches temperatures exceeding 50 °C, which causes tumor coagulation necrosis and unfavorable inflammatory reactions, ultimately decreasing its efficacy. In this study, multifunctional two-dimensional Bi2Se3 nanodisks were synthesized as noninflammatory photothermal agents for glioma therapy. The Bi2Se3 nanodisks showed high photothermal stability and biocompatibility and no apparent toxicology. In addition, in vitro and in vivo studies revealed that the Bi2Se3 nanodisks effectively ablated gliomas at relatively low concentrations and inhibited tumor proliferation and migration. Moreover, the multienzymatic activity of the Bi2Se3 nanodisks inhibited the PTT-induced inflammatory response through their high ability to scavenge reactive oxygen species. Finally, the Bi2Se3 nanodisks demonstrated computed tomography capabilities for integrating diagnosis and treatment. These findings suggest that multifunctional Bi2Se3 nanodisk nanozymes can enable more effective cancer therapy and noninflammatory PTT.

Tungsten-based polyoxometalate nanoclusters with remarkable reactive oxygen species-scavenging activity efficiently quenched luminol-based electrochemiluminescence for sensitive detection of Her-2

This study aimed to develop a quenching-type electrochemiluminescence (ECL) immunosensor for human epidermal growth factor receptor (Her-2) detection. Firstly, Pd/NiFeOx nanoflowers decorated by in situ formation of gold nanoparticles (Au NPs) and 2D Ti3C2 MXene nanosheets were synthesized (AuPd/NiFeOx/Ti3C2) as carriers to load luminol and primary antibodies. Impressively, AuPd/NiFeOx/Ti3C2 with excellent peroxidase-like activity could accelerate the decomposition of the coreactant H2O2 generating more reactive oxygen species (ROSs) under the working potential from 0 to 0.8 V, resulting in highly efficient ECL emission at 435-nm wavelengths. The introduction of tungsten-based polyoxometalate nanoclusters (W-POM NCs) which exhibit remarkable ROSs-scavenging activity as secondary antibody labels could improve the sensitivity of immunosensors. The ZnO nanoflowers were employed to encapsulate minute-sized W-POM NCs, and polydopamine was self-polymerized on the surface of Zn(W-POM)O to anchor secondary antibodies. The mechanism of the quenching strategy was explored and it was found that W-POM NCs could consume ROSs by the redox reaction of W5+ resulting in W6+. The proposed ECL immunosensor displayed a wide linear response range of 0.1 pg·mL-1 to 50 ng·mL-1, and a low detection limit of 0.036 pg mL-1 (S/N = 3). The recoveries ranged from 93.9 to 99.4%, and the relative standard deviation (RSD) was lower than 10%. This finding is promising for the design of detecting new protein biomarkers.

Hafnium carbide nanoparticles for noninflammatory photothermal cancer therapy

Photothermal therapy (PTT) effectively suppresses tumor growth with high selectivity. Nevertheless, PTT may cause an inflammatory response that leads to tumor recurrence and treatment resistance, which are the main disadvantages of PTT. Herein, monodisperse hafnium carbide nanoparticles (HfC NPs) were successfully prepared for noninflammatory PTT of cancer. HfC NPs possessed satisfactory near-infrared (NIR) absorption, good photothermal conversion efficiency (PTCE, 36.8 %) and photothermal stability. Furthermore, holding large surface areas and intrinsic redox-active sites, HfC NPs exhibited excellent anti-inflammatory properties due to their antioxidant and superoxide dismutase (SOD) enzymatic activities. In vitro and in vivo experiments confirmed that HfC NPs converted light energy into heat energy upon NIR laser irradiation to kill cancer cells through PTT and achieved a better therapeutic effect by anti-inflammatory effects after PTT. This work highlights that multifunctional HfC NPs can be applied in noninflammatory PTT with outstanding safety and efficacy.

Recent Advances in Polyoxometalate Based Nanoplatforms Mediated Reactive Oxygen Species Cancer Therapy

The potential of reactive oxygen species (ROS) cancer therapy in tumor treatment has been greatly enhanced by the introduction of catalytically superior polyoxometalate (POM)-based nanoplatforms, mainly composed of atomic clusters consisting of pre-transition metals and oxygen. These nanoplatforms have unique advantages, such as Fenton activity at neutral pH, induction of cellular ferroptosis instead of just apoptosis, and sensitivity to external field stimulation. However, there are also inevitable challenges such as neutralization of ROS by the antioxidant system of the tumor microenvironment (TME), hypoxia, and limited hydrogen peroxide concentrations. This review article aims to provide an overview of recent research advancements in POM-based nanoplatforms for ROS therapy from the perspective of chemical reactions and biological processes, addressing endogenous and exogenous factors that affect the antitumor efficacy. Endogenous factors include the mechanism of ROS generation by POM, the impact of pH and antioxidant systems on POM, and the various manners of tumor cell death. Exogenous stimuli mainly include light, heat, X-rays, and electricity. The article analyzes the specific mechanisms of action of each influencing factor in the first two sections, concluding with the limitations of the present study and some possible directions for future research.

Natural Targeting Potent ROS-Eliminating Tungsten-Based Polyoxometalate Nanodots for Efficient Treatment of Pulmonary Hypertension

Pulmonary hypertension (PH) is a disease of pulmonary artery stenosis and blockage caused by abnormal pulmonary artery smooth muscle cells (PASMCs), with high morbidity and mortality. High levels of reactive oxygen species (ROS) in pulmonary arteries play a crucial role in inducing phenotypic switch and abnormal proliferation of PASMCs. However, antioxidants are rarely approved for the treatment of PH because of a lack of targeting and low bioavailability. In this study, the presence of an enhanced permeability and retention effect (EPR)-like effect in the pulmonary arteries of PH is revealed by tissue transmission electron microscopy (TEM). Subsequently, for the first time, tungsten-based polyoxometalate nanodots (WNDs) are developed with potent elimination of multiple ROS for efficient treatment of PH thanks to the high proportion of reduced W5+ . WNDs are effectively enriched in the pulmonary artery by intravenous injection because of the EPR-like effect of PH, and significantly prevent the abnormal proliferation of PASMCs, greatly improve the remodeling of pulmonary arteries, and ultimately improve right heart function. In conclusion, this work provides a novel and effective solution to the dilemma of targeting ROS for the treatment of PH.

pH-Activated Ce-Doped Molybdenum Oxide Nanoclusters for Tumor Microenvironment Responsive Photothermal and Chemodynamic Therapy

Molybdenum-based nanomaterials have shown promise for anticancer treatment due to their strong photothermal and redox-activated capabilities. Herein, we have fabricated cerium-doped MoO_x (Ce-MoO_v) with tunable Mo/Ce molar ratios by a one-pot method and investigated their effect on chemodynamic therapy (CDT) and photothermal therapy (PTT). It is found that Ce-MoO_v can self-assemble into nanoclusters in acidic conditions and the increasing Ce amount will generate oxygen vacancy defects and induce the valence change of Mo⁶⁺/Mo⁵⁺ and Ce⁴⁺/Ce³⁺, which leads to strong near-infrared absorption with high photothermal conversion efficiency of 71.31 and 49.86% for 808 and 1064 nm. Other than photothermal conversion, the materials demonstrate pH-/glutathione (GSH)-activated photoacoustic (PA) imaging capability in vitro. In addition, Ce-MoO_v acts as a CDT reagent capable of converting endogenous H₂O₂ to two types of reactive oxygen species (^•OH, ¹O₂) while depleting GSH. Ce-MoO_v demonstrates an excellent therapeutic effect against HCT116 cells and effectively reduces the intracellular GSH level and significantly increases the number of reactive radicals under 1064 nm laser irradiation as compared with the no-laser group in vitro. This work provides a new paradigm using lanthanide-doped polymetallic oxides for pH-/GSH-responsive photothermal/chemodynamic therapy with PA imaging ability.

Anti-inflammatory strategies for photothermal therapy of cancer

High temperature generated by photothermal therapy (PTT) can trigger an inflammatory response at the tumor site, which not only limits the efficacy of PTT but also increases the risk of tumor metastasis and recurrence. In light of the current limitations posed by inflammation in PTT, several studies have revealed that inhibiting PTT-induced inflammation can significantly improve the efficacy of cancer treatment. In this review, we summarize the research progress made in combining anti-inflammatory strategies to enhance the effectiveness of PTT. The goal is to offer valuable insights for developing better-designed photothermal agents in clinical cancer therapy.

NIR-responsive molybdenum (Mo)-based nanoclusters enhance ROS scavenging for osteoarthritis therapy

Osteoarthritis (OA) is one of the most prevalent musculoskeletal disorders globally, and treating OA remains a significant challenge. Currently, pharmacological treatments primarily aim to alleviate the OA symptoms associated with inflammation and pain, and no disease-modifying therapies are available to delay OA development and progression. Reactive oxygen species (ROS) play an essential role in OA development and progression, which are a promising target for curing OA. In this study, it was found that photothermal properties of near-infrared (NIR) irradiation enhanced the ROS scavenging activity of molybdenum-based polyoxometalate (POM) nanoclusters. Because of enhanced ROS scavenging, NIR-responsive POM nanoclusters were developed as novel excellent nano-antioxidants for OA protection. The results demonstrated that NIR-responsive POM exhibited outstanding antioxidant activity and superexcellent anti-inflammatory effects, which could effectively alleviate the clinical symptoms of OA mice, diminish inflammatory cytokines, reduce catabolic proteases, and mitigate the progression of OA. Meanwhile, the local treatment had no side effects on normal tissues. Thus, this study pioneered the application of POM for alleviating OA with expected safety and efficiency.

Renal Clearable Mo-Based Polyoxometalate Nanoclusters: A Promising Radioprotectant against Ionizing Irradiation

In response to diffused ionizing radiation damage throughout the body caused by nuclear leaks and inaccurate radiotherapy, radioprotectants with considerable free radical scavenging capacities, along with negligible adverse effects, are highly regarded. Herein, unlike being performed as toxic chemotherapeutic drug candidates, molybdenum-based polyoxometalate nanoclusters (Mo-POM NCs) were developed as a non-toxic potent radioprotectant with impressive free radical scavenging capacities for ionizing radiation protection. In comparison to the clinically used radioprotectant drug amifostine (AM), the as-prepared Mo-POM NCs exhibited effective shielding capacity by virtue of their antioxidant properties resulting from a valence shift of molybdenum ions, alleviating not only ionizing radiation-induced DNA damage but also disruption of the radiation-sensitive hematopoietic system. More encouragingly, without trouble with long-term retention in the body, ultra-small sized Mo-POM NCs prepared by the mimetic Folin-Ciocalteu assay can be removed from the body through the renal-urinary pathway and the hepato-enteral excretory system after completing the mission of radiation protection. This work broadened the biological applications of metal-based POM chemotherapeutic drugs to act as a neozoic radioprotectant.

Optimizing an Enzymatic Extraction Method for the Flavonoids in Moringa (Moringa oleifera Lam.) Leaves Based on Experimental Designs Methodologies

Moringa oleifera Lam. is known to have significant antioxidant properties. Because of this, the development of an optimal extraction method is crucial to obtain pharmacological products based on the bioactive compounds produced by this tree. Through a Plackett-Burman and a Box-Behnken design, enzymatic extraction conditions (temperature, agitation, solvent pH and composition, sample-to-solvent ratio, enzyme-to-sample ratio and extraction time) have been optimized using normalized areas (UA/g) as response variable and relative mass (mg/g) as quantification variable. Extractions were performed in an incubator, where all the extraction conditions could be digitally controlled. Thus, 58.9 °C, 50 rpm, 4.0 pH, 32.5% EtOH, 0.2 g sample in 15 mL solvent and 106 U/g were established as the optimal extraction conditions for the extraction with a mix of pectinases coming from Aspergillus niger. Under these optimal conditions, two-minute extractions were performed and evaluated through a single factor design. The enzymatic extraction method demonstrated its suitability to produce extracts with good antioxidant power (antioxidant activity 4.664 ± 0.059 mg trolox equivalent/g sample and total phenolic compounds 6.245 ± 0.101 mg gallic acid equivalent/g sample). The method was also confirmed to have good repeatability (1.39%) and intermediate precision (2.37%) levels.

Liquid exfoliation of ultrasmall zirconium carbide nanodots as a noninflammatory photothermal agent in the treatment of glioma

Photothermal therapy (PTT), like other clinical translational tumor ablation techniques, requires a temperature increase above 50 °C to cause necrosis and death of tumor cells. Although the tumor can be eliminated rapidly by PTT, the inflammatory response is triggered by the large amounts of released reactive oxygen species (ROS). Therefore, liquid exfoliation was used to create ultrasmall zirconium carbide nanodots (NDs) with an average diameter of approximately 4.5 nm as noninflammatory/anti-inflammatory photosensitizers for PTT of glioma. Ultrasmall ZrC NDs showed excellent photothermal stability and biocompatibility but no obvious toxicity. Moreover, the ultrasmall ZrC NDs effectively ablated glioma at relatively low concentrations and inhibited tumor migration and proliferation in vitro and in vivo. Furthermore, the excellent ROS-scavenging ability of ultrasmall ZrC NDs suppressed the inflammatory response to PTT. Intriguingly, we found that ZrC had the capability of performing CT imaging. We demonstrated that the ultrasmall ZrC NDs created in this study could effectively and safely treat glioma without inflammation.

Targeted CuFe2O4 hybrid nanoradiosensitizers for synchronous chemoradiotherapy

Multifunctional nanoplatforms based on novel bimetallic nanoparticles have emerged as effective radiosensitizers owing to their potential capability in cancer cells radiosensitization. Implementation of chemotherapy along with radiotherapy, known as synchronous chemoradiotherapy, can augment the treatment efficacy. Herein, a tumor targeted nanoradiosensitizer with synchronous chemoradiotion properties, termed as CuFe₂O₄@BSA-FA-CUR, loaded with curcumin (CUR) and modified by bovine serum albumin (BSA) and folic acid (FA) was developed to enhance tumor accumulation and promote the anti-cancer activity while attenuating adverse effects. Both copper (Cu) and iron (Fe) were utilized in the construction of these submicron scale entities, therefore strong radiosensitization effect is anticipated by implementation of these two metals. The structure-function relationships between constituents of nanomaterials and their function led to the development of nanoscale materials with great radiosensitizing capacity and biosafety. BSA was used to anchor Fe and Cu ions but also to improve colloidal stability, blood circulation time, biocompatibility, and further functionalization. Moreover, to specifically target tumor sites and enhance cellular uptake, FA was conjugated onto the surface of hybrid bimetallic nanoparticles. Finally, CUR as a natural chemotherapeutic agent was encapsulated into the developed bimetallic nanoparticles. With incorporation of all abovementioned stages into one multifunctional nanoplatform, CuFe₂O₄@BSA-FA-CUR is produced for synergistic chemoradiotherapy with positive outcomes. In vitro investigation revealed that these nanoplatforms bear excellent biosafety, great tumor cell killing ability and radiosensitizing capacity. In addition, high cancer-suppression efficiency was observed through in vivo studies. It is worth mentioning that co-use of CuFe₂O₄@BSA-FA-CUR nanoplatforms and X-ray radiation led to complete tumor ablation in almost all of the treated mice. No mortality or radiation-induced normal tissue toxicity were observed following administration of CuFe₂O₄@BSA-FA-CUR nanoparticles which highlights the biosafety of these submicron scale entities. These results offer powerful evidence for the potential capability of CuFe₂O₄@BSA-FA-CUR in radiosensitization of malignant tumors and opens up a new avenue of research in this area.

A Polyoxometalate-Encapsulated Metal-Organic Framework Nanoplatform for Synergistic Photothermal-Chemotherapy and Anti-Inflammation of Ovarian Cancer

Photothermal therapy (PTT), as a noninvasive and local treatment, has emerged as a promising anti-tumor strategy with minimal damage to normal tissue under spatiotemporally controllable irradiation. However, the necrosis of cancer cells during PTT will induce an inflammatory reaction, which may motivate tumor regeneration and resistance to therapy. In this study, polyoxometalates and a chloroquine diphosphate (CQ) co-loaded metal-organic framework nanoplatform with hyaluronic acid coating was constructed for efficient ovarian cancer therapy and anti-inflammation. Our results demonstrated that this nanoplatform not only displayed considerable photothermal therapeutic capacity under 808 nm near-infrared laser, but also had an impressive anti-inflammatory capacity by scavenging reactive oxygen species in the tumor microenvironment. CQ with pH dependence was used for the deacidification of lysosomes and the inhibition of autophagy, cutting off a self-protection pathway induced by cell necrosis-autophagy, and achieving the synergistic treatment of tumors. Therefore, we combined the excellent properties of these materials to synthesize a nanoplatform and explored its therapeutic effects in various aspects. This work provides a promising novel prospect for PTT/anti-inflammation/anti-autophagy combinations for efficient ovarian cancer treatment through the fine tuning of material design.

Manganese-Based Nanozymes: Preparation, Catalytic Mechanisms, and Biomedical Applications

Manganese (Mn) has attracted widespread attention due to its low-cost, nontoxicity, and valence-rich transition. Various Mn-based nanomaterials have sprung up and are employed in diverse fields, particularly Mn-based nanozymes, which combine the physicochemical properties of Mn-based nanomaterials with the catalytic activity of natural enzymes, and are attracting a surge of research, especially in the field of biomedical research. In this review, the typical preparation strategies, catalytic mechanisms, advances and perspectives of Mn-based nanozymes for biomedical applications are systematically summarized. The application of Mn-based nanozymes in tumor therapy and sensing detection, together with an overview of their mechanism of action is highlighted. Finally, the prospective directions of Mn-based nanozymes from five perspectives: innovation, activity enhancement, selectivity, biocompatibility, and application broadening are discussed.

Surface Engineering Promoted Insulin-Sensitizing Activities of Sub-Nanoscale Vanadate Clusters through Regulated Pharmacokinetics and Bioavailability

The therapeutic application of vanadium compounds is plagued by their poor bioavailability and potential adverse effects. Herein, 1 nm polyoxovanadate (POV) clusters are functionalized with alkyl chains of various lengths and studied for the effect of surface engineering on their preclinical pharmacokinetics and typical insulin-sensitizing activity. The concentrations of surface engineered POVs in plasma, urine, and feces are monitored after a single administration to rats. The POVs exhibit a two-compartment profile of in vivo kinetics, and the surface engineering effect plays an important role in renal clearance of the POVs comparable to small molecules. POVs functionalized with long alkyl chains show much shorter elimination half time t_1/2β and higher elimination fractions (50%) within 48 h than pristine POVs, suggesting favorable elimination kinetics to mitigate the possible side effects of vanadium. Meanwhile, long alkyl chain modification leads to a 76% increment of oral bioavailability in contrast to unmodified POVs. As suggested by glucose tolerance tests and sub-chronic toxicity tests, the above two factors contribute to the enhanced therapeutic efficacy of POVs while mitigating their adverse effects. The surface engineering protocol provides a feasible approach to the optimization of the bioavailability and pharmacokinetic properties of POVs for promoted insulin-sensitizing activities.

Industrialization’s eye view on theranostic nanomedicine

The emergence of nanomedicines (NMs) in the healthcare industry will bring about groundbreaking improvements to the current therapeutic and diagnostic scenario. However, only a few NMs have been developed into clinical applications due to a lack of regulatory experience with them. In this article, we introduce the types of NM that have the potential for clinical translation, including theranostics, multistep NMs, multitherapy NMs, and nanoclusters. We then present the clinical translational challenges associated with NM from the pharmaceutical industry’s perspective, such as NMs’ intrinsic physiochemical properties, safety, scale-up, lack of regulatory experience and standard characterization methods, and cost-effectiveness compared with their traditional counterparts. Overall, NMs face a difficult task to overcome these challenges for their transition from bench to clinical use.

Promising application of polyoxometalates in the treatment of cancer, infectious diseases and Alzheimer's disease

As shown in studies conducted in recent decades, polyoxometalates (POMs), as inorganic metal oxides, have promising biological activities, including antitumor, anti-infectious and anti-Alzheimer’s activities, due to their special structures and properties. However, some side effects impede their clinical applications to a certain extent. Compared with unmodified POMs, POM-based inorganic–organic hybrids and POM-based nanocomposite structures show significantly enhanced bioactivity and reduced side effects. In this review, we introduce the biological activities of POMs and their derivatives and highlight the side effects of POMs on normal cells and organisms and their possible mechanisms of action. We then propose a development direction for overcoming their side effects. POMs are expected to constitute a new generation of inorganic metal drugs for the treatment of cancer, infectious diseases, and Alzheimer's disease.

Graphical abstract

Polyoxometalate-based materials in extraction, and electrochemical and optical detection methods: A review

Polyoxometalates (POMs) as metal-oxide anions have exceptional properties like high negative charges, remarkable redox abilities, unique ligand properties and availability of organic grafting. Moreover, the amenability of POMs to modification with different materials makes them suitable as precursors to further obtain new composites. Due to their unique attributes, POMs and their composites have been utilized as adsorbents, electrodes and catalysts in extraction, and electrochemical and optical detection methods, respectively. A survey of the recent progress and developments of POM-based materials in these methods is therefore desirable, and should be of great interest. In this review article, POM-based materials, their properties as well as their identification methods, and analytical applications as adsorbents, electrodes and catalysts, and corresponding mechanisms of action, where relevant, are reviewed. Some current issues of the utilization of these materials and their future prospects in analytical chemistry are discussed.

Three birds with one stone: co-encapsulation of diclofenac and DL-menthol for realizing enhanced energy deposition, glycolysis inhibition and anti-inflammation in HIFU surgery

Despite attracting increasing attention in clinic, non-invasive high-intensity focused ultrasound (HIFU) surgery still commonly suffers from tumor recurrence and even matastasis due to the generation of thermo-resistance in non-apoptotic tumor cells and adverse therapy-induced inflammation with enhanced secretion of growth factors in irradiated region. In this work, inspired by the intrinsic property that the expression of thermo-resistant heat shock proteins (HSPs) is highly dependent with adenosine triphosphate (ATP), dual-functionalized diclofenac (DC) with anti-inflammation and glycolysis-inhibition abilities was successfully co-encapsulated with phase-change dl-menthol (DLM) in poly(lactic-co-glycolic acid) nanoparticles (DC/DLM@PLGA NPs) to realize improved HIFU surgery without causing adverse inflammation. Both in vitro and in vivo studies demonstrated the great potential of DC/DLM@PLGA NPs for serving as an efficient synergistic agent for HIFU surgery, which can not only amplify HIFU ablation efficacy through DLM vaporization-induced energy deposition but also simultaneously sensitize tumor cells to hyperthermia by glycolysis inhibition as well as diminished inflammation. Thus, our study provides an efficient strategy for simultaneously improving the curative efficiency and diminishing the harmful inflammatory responses of clinical HIFU surgery.

Combination of Photothermal Therapy with Anti-Inflammation Therapy Attenuates the Inflammation Tumor Microenvironment and Weakens Immunosuppression for Enhancement Antitumor Treatment

Photothermal therapy has gained widespread attention in cancer treatment, although its efficacy is suppressed due to the inflammatory response and immunosuppression, resulting in a discounted therapeutic effect. In this contribution, a high-performance NIR absorption organic small chromophore is developed, which is encapsulated into Pluronic F-127 to fabricate NIR absorption organic nanoparticles (TTM NPs) with excellent photothermal conversion efficiency (51.49%) for photothermal therapy. TTM NPs based photothermal therapy are combined with Aspisol, a kind of nonsteroidal anti-inflammatory drug, to weaken the inflammation and immunosuppression tumor microenvironment and enhance the antitumor effect. The results prove that the combination therapy realizes effective thermal elimination of primary tumors, inhibition of distant tumors, and suppression of tumor metastasis. The data show that combination therapy can suppress the expression of inflammatory factors, enhance dendritic cell activation and maturation, reverse the immunosuppression, facilitate T cell infiltration, and restore antitumor cytotoxic T lymphocyte activity. This study provides a paradigm to extend the development of photothermal therapy.

Injectable hydrogel platform with biodegradable Dawson-type polyoxometalate and R848 for combinational photothermal-immunotherapy of cancer

Photothermal therapy (PTT) is a powerful strategy for cancer treatment with minimal invasiveness but still limited by lack of long-term efficacy against tumor recurrence and toxicity concerns about the slow biodegradability of the PTT agents. Herein, an injectable hydrogel platform (R848/POM@GG) of gellan gum co-loaded with Dawson-type {P₂Mo₁₈} polyoxometalate (POM) and Toll-like receptors agonist resiquimod (R848) is developed for combinational photothermal-immunotherapy of cancer. The POM-based gellan gum hydrogel (POM@GG) exhibits high photothermal conversion efficiency (63.1%) at a safe power density of 0.3 W cm^-2 and good photostability during five cycles. By further incorporation of R848, the obtained R848/POM@GG exerts synergetic photothermal-immunotherapy on solid tumors, giving a high tumor inhibition rate of 99.3% and negligible lung metastases in the breast cancer mice models. A strong antitumor immune system with significantly elevated TNF-α, IL-2, and IL-6 levels is activated by R848. Additionally, the POM clusters gradually degrade to nontoxic molybdate in the physiological environment. Overall, the injectable hydrogel platform of R848/POM@GG has great translational potential for localized antitumor treatments.

A molybdenum oxide-based degradable nanosheet for combined chemo-photothermal therapy to improve tumor immunosuppression and suppress distant tumors and lung metastases

Molybdenum oxide (MoOx) nanosheets have drawn increasing attention for minimally invasive cancer treatments but still face great challenges, including complex modifications and the lack of efficient accumulation in tumor. In this work, a novel multifunctional degradable FA-BSA-PEG/MoOx nanosheet was fabricated (LA-PEG and FA-BSA dual modified MoOx): the synergistic effect of PEG and BSA endows the nanosheet with excellent stability and compatibility; the FA, a targeting ligand, facilitates the accumulation of nanosheets in the tumor. In addition, DTX, a model drug for breast cancer treatment, was loaded (76.49%, 1.5 times the carrier weight) in the nanosheets for in vitro and in vivo antitumor evaluation. The results revealed that the FA-BSA-PEG/MoOx@DTX nanosheets combined photothermal and chemotherapy could not only inhibit the primary tumor growth but also suppress the distant tumor growth (inhibition rate: 51.7%) and lung metastasis (inhibition rate: 93.6%), which is far more effective compared to the commercial Taxotere®. Exploration of the molecular mechanism showed that in vivo immune response induced an increase in positive immune responders, suppressed negative immune suppressors, and established an inflammatory tumor immune environment, which co-contributes towards effective suppression of tumor and lung metastasis. Our experiments demonstrated that this novel multifunctional nanosheet is a promising platform for combined chemo-photothermal therapy.

Fe Foam-Supported FeS2-MoS2 Electrocatalyst for N2 Reduction under Ambient Conditions

Highly efficient catalysts with enough selectivity and stability are essential for electrochemical nitrogen reduction reaction (e-NRR) that has been considered as a green and sustainable route for synthesis of NH₃. In this work, a series of three-dimensional (3D) porous iron foam (abbreviated as IF) self-supported FeS₂-MoS₂ bimetallic hybrid materials, denoted as FeS₂-MoS₂@IF_x, x = 100, 200, 300, and 400, were designed and synthesized and then directly used as the electrode for the NRR. Interestingly, the IF serving as a slow-releasing iron source together with polyoxomolybdates (NH₄)₆Mo₇O₂₄·4H₂O as a Mo source were sulfurized in the presence of thiourea to form self-supported FeS₂-MoS₂ on IF (abbreviated as FeS₂-MoS₂@IF₂₀₀) as an efficient electrocatalyst. Further material characterizations of FeS₂-MoS₂@IF₂₀₀ show that flower cluster-like FeS₂-MoS₂ grows on the 3D skeleton of IF, consisting of interconnected and staggered nanosheets with mesoporous structures. The unique 3D porous structure of FeS₂-MoS₂@IF together with synergy and interface interactions of bimetallic sulfides would make FeS₂-MoS₂@IF possess favorable electron transfer tunnels and expose abundant intrinsic active sites in the e-NRR. It is confirmed that synthesized FeS₂-MoS₂@IF₂₀₀ shows a remarkable NH₃ production rate of 7.1 ×10^-10 mol s^-1 cm^-2 at -0.5 V versus the reversible hydrogen electrode (vs RHE) and an optimal faradaic efficiency of 4.6% at -0.3 V (vs RHE) with outstanding electrochemical and structural stability.

Enzyme-Responsive Materials as Carriers for Improving Photodynamic Therapy

Photodynamic therapy (PDT) is a mini-invasive therapy on malignancies via reactive oxygen species (ROS) induced by photosenitizer (PS) upon light irradiation. However, poor target of PS to tumor limits the clinical application of PDT. Compared with normal tissues, tumor tissues have a unique enzymatic environment. The unique enzymatic environment in tumor tissues has been widely used as a target for developing smart materials to improve the targetability of drugs to tumor. Enzyme-responsive materials (ERM) as a smart material can respond to the enzymes in tumor tissues to specifically deliver drugs. In PDT, ERM was designed to react with the enzymes highly expressed in tumor tissues to deliver PS in the target site to prevent therapeutic effects and avoid its side-effects. In the present paper, we will review the application of ERM in PDT and discuss the challenges of ERM as carriers to deliver PS for further boosting the development of PDT in the management of malignancies.

Near-infrared light-controllable MXene hydrogel for tunable on-demand release of therapeutic proteins

Precise delivery of therapeutic protein drugs that specifically modulate desired cellular responses is critical in clinical practice. However, the spatiotemporal regulation of protein drugs release to manipulate the target cell population in vivo remains a huge challenge. Herein, we have rationally developed an injectable and Near-infrared (NIR) light-responsive MXene-hydrogel composed of Ti₃C₂, agarose, and protein that enables flexibly and precisely control the release profile of protein drugs to modulate cellular behaviors with high spatiotemporal precision remotely. As a proof-of-concept study, we preloaded hepatic growth factor (HGF) into the MXene@hydrogel (MXene@agarose/HGF) to activate the c-Met-mediated signaling by NIR light. We demonstrated NIR light-instructed cell diffusion, migration, and proliferation at the user-defined localization, further promoting angiogenesis and wound healing in vivo. Our approach's versatility was validated by preloading tumor necrotic factor-α (TNF-α) into the composite hydrogel (MXene@agarose/TNF-α) to promote the pro-apoptotic signaling pathway, achieving the NIR light-induced programmed cell deaths (PCD) of tumor spheroids. Taking advantage of the deep-tissue penetrative NIR light, we could eradicate the deep-seated tumors in a xenograft model exogenously. Therefore, the proposed MXene-hydrogel provides the impetus for developing therapeutic synthetic materials for light-controlled drug release under thick tissue, which will find promising applications in regenerative medicine and tumor therapy. STATEMENT OF SIGNIFICANCE: Current stimuli-responsive hydrogels for therapeutic proteins delivery mainly depend on self-degradation, passive diffusion, or the responsiveness to cues relevant to diseases. However, it remains challenging to spatiotemporally deliver protein-based drugs to manipulate the target cell population in vivo in an "on-demand" manner. Therefore, we have rationally constructed an injectable and Near-infrared (NIR) light-responsive composite hydrogel by embedding Ti₃C₂ MXene and protein drugs within an agarose hydrogel to enable the remote control of protein drugs delivery with high spatiotemporal precision. The NIR light-controlled release of the growth factor or cytokine has been carried out to regulate receptor-mediated cellular behaviors under deep tissue for skin wound healing or cancer therapy. This system will provide the potential for precision medicine through the development of intelligent drug delivery systems.

Self-Assembled Polyoxometalate Nanodots as Bidirectional Cluster Catalysts for Polysulfide/Sulfide Redox Conversion in Lithium-Sulfur Batteries

Polyoxometalates (POMs) are a class of discrete molecular inorganic metal-oxide clusters with reversible multielectron redox capability. Taking advantage of their redox properties, POMs are thus expected to be directly involved in the lithium-sulfur batteries (Li-S, LSBs) system as a bidirectional molecular catalyst. Herein, we design a three-dimensional porous structure of reduced graphene-carbon nanotube skeleton supported POM catalyst as a high-conductive and high-stability host material. Based on various spectroscopic techniques and in situ electrochemical studies together with computational methods, the catalytic mechanism of POM clusters in Li-S battery was systematically clarified at the molecular level. The constructed POM-based sulfur cathode delivers a reversible capacity 1110 mAh g^-1 at 1.0 C and cycling stability up to 1000 cycles at 3.0 C. Furthermore, Li-S pouch/beaker batteries with a POM-based cathode were successfully demonstrated. This work provides essential inputs to promote molecular catalyst design and its application in LSBs.

A versatile nanoagent for multimodal imaging-guided photothermal and anti-inflammatory combination cancer therapy

Photothermal therapy (PTT) has drawn great attention in cancer treatment because of its minimal invasiveness and high spatiotemporal selectivity, but it still encounters severe obstacles like heat-resistance, metastasis and recurrence. A key reason for the treatment failure is the highly inflammatory tumor microenvironment caused by hyperthermia. A simultaneous anti-inflammatory therapy alongside the PTT has great potential for overcoming the drawbacks of PTT; however, it has been less reported and further study is urgently needed. In addition, as many inorganic photothermal agents have no inherent imaging capability, diagnostic strategies should be introduced to help identify cancerous lesions and find the best treatment time period for PTT. Herein, we developed a versatile theranostic nanoagent (named T-lipos-CPAuNCs) for synergistic multimodal imaging-guided photothermal/anti-inflammatory cancer therapy. Perfluorohexane (PFH) loaded AuNCs and the anti-inflammatory drug celecoxib were encapsulated into the tumor-targeting cyclic Arg-Gly-Asp (cRGD) peptide modified liposomes to form T-lipos-CPAuNCs. The T-lipos-CPAuNCs accumulated in the tumor tissue and selectively targeted the cancer cells, and converted photo to thermal energy under near-infrared (NIR) laser irradiation to kill the cancer cells by PTT. The high temperature further accelerated the release of celecoxib to exert an anti-inflammatory effect, while on the other hand led to liquid to gas phase transition of PFH to facilitate ultrasound (US) imaging. The T-lipos-CPAuNCs also exhibited photoacoustic (PA) imaging capability. In vitro and in vivo experiments established that under the guidance of multimodal imaging, T-lipos-CPAuNCs significantly suppressed the tumor growth by PTT and prevented tumor metastasis with non-apparent tumor inflammation. The developed theranostic nanosystem (T-lipos-CPAuNCs) shows great potential for PA/US multimodal imaging guided photothermal/anti-inflammatory combination cancer therapy.

An integrated giant polyoxometalate complex for photothermally enhanced catalytic oxidation

A strategy integrating near infrared (NIR) photothermal and catalytic effects within one active center beyond ultraviolet and visible light is proposed without the combination of separated photothermal transformation components. A giant polyoxomolybdate, which has high NIR photothermal conversion efficiency, is selected as the model catalyst, while a cationic β-cyclodextrin is used to cover its negatively charged surface electrostatically. Under NIR light radiation, the designed catalyst increases catalytic activity of cyclohexene oxidation under O2 atmosphere in water. The conversion reaches about pentaploid of the reaction without NIR radiation. By excluding heating effect from the external heater at the same temperature, about twice as much enhancement, which can be attributed to the sole photothermal action, is still observed. While the catalytic center is shielded by the organic porous layer, the surface cavity allows the integrated catalyst to conduct a selective catalysis by screening the molecules in size over the surface channel.

Inorganic nanomaterials with rapid clearance for biomedical applications

Inorganic nanomaterials that have inherently exceptional physicochemical properties (e.g., catalytic, optical, thermal, electrical, or magnetic performance) that can provide desirable functionality (e.g., drug delivery, diagnostics, imaging, or therapy) have considerable potential for application in the field of biomedicine. However, toxicity can be caused by the long-term, non-specific accumulation of these inorganic nanomaterials in healthy tissues, preventing their large-scale clinical utilization. Over the past several decades, the emergence of biodegradable and clearable inorganic nanomaterials has offered the potential to prevent such long-term toxicity. In addition, a comprehensive understanding of the design of such nanomaterials and their metabolic pathways within the body is essential for enabling the expansion of theranostic applications for various diseases and advancing clinical trials. Thus, it is of critical importance to develop biodegradable and clearable inorganic nanomaterials for biomedical applications. This review systematically summarizes the recent progress of biodegradable and clearable inorganic nanomaterials, particularly for application in cancer theranostics and other disease therapies. The future prospects and opportunities in this rapidly growing biomedical field are also discussed. We believe that this timely and comprehensive review will stimulate and guide additional in-depth studies in the area of inorganic nanomedicine, as rapid in vivo clearance and degradation is likely to be a prerequisite for the future clinical translation of inorganic nanomaterials with unique properties and functionality.

NIR responsive tumor vaccine in situ for photothermal ablation and chemotherapy to trigger robust antitumor immune responses

Background

Therapeutic tumor vaccine (TTV) that induces tumor-specific immunity has enormous potentials in tumor treatment, but high heterogeneity and poor immunogenicity of tumor seriously impair its clinical efficacy. Herein, a novel NIR responsive tumor vaccine in situ (HA-PDA@IQ/DOX HG) was prepared by integrating hyaluronic acid functionalized polydopamine nanoparticles (HA-PDA NPs) with immune adjuvants (Imiquimod, IQ) and doxorubicin (DOX) into thermal-sensitive hydrogel.

Results

HA-PDA@IQ NPs with high photothermal conversion efficiency (41.2%) and T₁-relaxation efficiency were using HA as stabilizer by the one-pot oxidative polymerization. Then, HA-PDA@IQ loaded DOX via π-π stacking and mixed with thermal-sensitive hydrogel to form the HA-PDA@IQ/DOX HG. The hydrogel-confined delivery mode endowed HA-PDA@IQ/DOX NPs with multiple photothermal ablation performance once injection upon NIR irradiation due to the prolonged retention in tumor site. More importantly, this mode enabled HA-PDA@IQ/DOX NPs to promote the DC maturation, memory T cells in lymphatic node as well as cytotoxic T lymphocytes in spleen.

Conclusion

Taken together, the HA-PDA@IQ/DOX HG could be served as a theranostic tumor vaccine for complete photothermal ablation to trigger robust antitumor immune responses.

An orthobiologics-free strategy for synergistic photocatalytic antibacterial and osseointegration

Tissue damage caused by hyperthermia during photothermal therapy (PTT) has largely limited its clinical applications for implant infection. However, rescue of tissue regeneration by conjugating orthobiologics with PTT has been problematic as they can easily deactivate biologics while eradicating bacteria. Herein, we report an orthobiologics-free strategy to synergistically couple photocatalytic antibacterial with pro-osteogenic capacity via self-assembly of copper sulphide nanoparticle (CuS NP) and reduced graphene oxide (rGO) on implant surface. This strategy not only offers enhanced photothermal effects for bacterial eradiation via near-infrared light (NIR), but also promotes vascularized osseointegration via cooperation of copper ion with rGO. In vitro and in vivo data showed that coupling CuS and rGO synergistically increased antibacterial efficacy of implants by 40 times and successfully destroyed bacterial biofilm upon NIR. Moreover, CuS/rGO decorated surface substantially improved bone marrow stromal cell adhesion, proliferation, as well as subsequent differentiation toward osteoblast. We also revealed that enhanced peri-implant vascularization may be attributed to the sustained release of copper ion from CuS NPs, which further collaborated with rGO to promote vascularized osseointegration. Altogether, this novel orthobiologics-free approach offers a practical alternative to circumvent the intrinsic drawbacks of PTT and endows powerful antibacterial and pro-osteogenic capacities for implant associated infections.

Bacterial hyperpolarization modulated by polyoxometalates for solutions of antibiotic resistance

Developing strategies against the antibiotic resistance is a major global challenge for public health. Here, we report the synergy of the combination of Preyssler-type polyoxometalates (POMs) ([NaP₅W₃₀O₁₁₀]^14- or [AgP₅W₃₀O₁₁₀]^14-) and ribosome-targeting antibiotics for high antibacterial efficiency with low risk of antibiotic resistance. Due to their ultra-small sizes and active surface ligands, POM anions show strong affinity to bacterial cell membrane and impose hyperpolarization of the bacterial cells as well as the decrease of Mg²⁺ influx by blocking Mg²⁺ transporters, which finally lead to the structural perturbations of ribosomes and instability of bacterial structures. The bacterial growth can, therefore, be regulated by the presence of POMs: a fraction of Bacillus subtilis shifted to a 'dormant', slow-growing cellular state (an extended lag phase) upon the application of subinhibitory concentration of POMs. An approach to combat antibiotic resistant bacteria by applying POMs at their early growth phase followed by antibiotic exposure is validated, and its high efficiency for bacterial control is confirmed.

Platinum-Doped Prussian Blue Nanozymes for Multiwavelength Bioimaging Guided Photothermal Therapy of Tumor and Anti-Inflammation

Developing appropriate photothermal agents to meet complex clinical demands is an urgent challenge for photothermal therapy of tumors. Here, platinum-doped Prussian blue (PtPB) nanozymes with tunable spectral absorption, high photothermal conversion efficiency, and good antioxidative catalytic activity are developed by one-step reduction. By controlling the doping ratio, PtPB nanozymes exhibit tunable localized surface plasmon resonance (LSPR) frequency with significantly enhanced photothermal conversion efficiency and allow multiwavelength photoacoustic/infrared thermal imaging guided photothermal therapy. Experimental band gap and density functional theory calculations further reveal that the decrement of free carrier concentrations and increase in circuit paths of electron transitions co-contribute to the enhanced photothermal conversion efficiency of PtPB with tunable LSPR frequency. Benefiting from antioxidative catalytic activity, PtPB can simultaneously relieve inflammation caused by hyperthermia. Moreover, PtPB nanozymes exhibited good biosafety after intravenous injection. Our findings provide a paradigm for designing safe and efficient photothermal agents to treat complex tumor diseases.

Polyoxometalate-Based Nanomaterials Toward Efficient Cancer Diagnosis and Therapy

As an emerging class of inorganic metal oxides, organically functionalized polyoxometalates (POMs) or POM-based nanohybrids have been demonstrated promising potential for the inhibition of various cancer types by the virtue of their diversity in structures and significantly reduced toxicity. This contribution summarizes the latest achievement of POM-based nanomaterials in cancer diagnosis and various therapeutics to put forward our fundamental viewpoints on the design principles of modified POMs based on their application. In addition, major challenges and perspectives in this field are also discussed. We expect that this review will provide a valuable and systematic reference for the further development of POM-based nanomaterials.

Light: A Magical Tool for Controlled Drug Delivery

Light is a particularly appealing tool for on-demand drug delivery due to its noninvasive nature, ease of application and exquisite temporal and spatial control. Great progress has been achieved in the development of novel light-driven drug delivery strategies with both breadth and depth. Light-controlled drug delivery platforms can be generally categorized into three groups: photochemical, photothermal, and photoisomerization-mediated therapies. Various advanced materials, such as metal nanoparticles, metal sulfides and oxides, metal-organic frameworks, carbon nanomaterials, upconversion nanoparticles, semiconductor nanoparticles, stimuli-responsive micelles, polymer- and liposome-based nanoparticles have been applied for light-stimulated drug delivery. In view of the increasing interest in on-demand targeted drug delivery, we review the development of light-responsive systems with a focus on recent advances, key limitations, and future directions.

Interface cisplatin-crosslinked doxorubicin-loaded triblock copolymer micelles for synergistic cancer therapy

Combination chemotherapy is an effective way to improve the therapeutic efficiency in anticancer treatment. Herein, we synthesized a novel amphiphilic triblock copolymer via a two-step ring-opening polymerization (ROP) followed by post-modification. Doxorubicin (DOX) was encapsulated into the copolymeric micelles through hydrophobic interactions, cisplatin (CDDP) was employed to in situ crosslink the interface of DOX-loaded micelles through Pt-carboxyl coordination interaction. The CDDP-mediated crosslinking improved the stability of the micelles and also reduced the release of DOX at physiological pH. After being taken up into the endosome/lysosome, the low environmental pH weakened the Pt-carboxyl coordination interactions, resulting in the destruction of the micelles and the release of CDDP and DOX. Moreover, these micelles loaded with dual drugs enabled a synergistic anticancer effect, showing promise as a potential drug delivery platform for cancer therapy.

Novel phthalocyanine-based micelles/PNIPAM composite hydrogels: spatially/temporally controlled drug release triggered by NIR laser irradiation

Near-infrared (NIR) light-responsive hydrogels hold significant potential for biomedical application, especially in the remote-controlled release of anticancer drugs.

Recent advances of polyoxometalates in multi-functional imaging and photothermal therapy

The recent advances of polyoxometalate clusters in terms of near infrared photothermal properties for targeted tumor therapy have been summarized while the combined applications with various bio-imaging techniques and chemotherapies are reviewed.