Noble Metal Nanoparticle-Based Photothermal Therapy: Development and Application in Effective Cancer Therapy.

Photothermal therapy (PTT) is a promising cancer therapy modality with significant advantages such as precise targeting, convenient drug delivery, better efficacy, and minimal adverse effects. Photothermal therapy effectively absorbs the photothermal transducers in the near-infrared region (NIR), which induces the photothermal effect to work. Although PTT has a better role in tumor therapy, it also suffers from low photothermal conversion efficiency, biosafety, and incomplete tumor elimination. Therefore, the use of nanomaterials themselves as photosensitizers, the targeted modification of nanomaterials to improve targeting efficiency, or the combined use of nanomaterials with other therapies can improve the therapeutic effects and reduce side effects. Notably, noble metal nanomaterials have attracted much attention in PTT because they have strong surface plasmon resonance and an effective absorbance light at specific near-infrared wavelengths. Therefore, they can be used as excellent photosensitizers to mediate photothermal conversion and improve its efficiency. This paper provides a comprehensive review of the key role played by noble metal nanomaterials in tumor photothermal therapy. It also describes the major challenges encountered during the implementation of photothermal therapy.

Oleoylethanolamide ameliorates motor dysfunction through PPARα-mediates oligodendrocyte differentiation and white matter integrity after ischemic stroke.

BACKGROUND AND AIM: Our previous study has revealed that OEA promotes motor function recovery in the chronic stage of ischemic stroke. However, the neuroprotective mechanism of OEA on motor function recovery after stroke still is unexplored. Therefore, the aim of this study was to explore the effects of OEA treatment on angiogenesis, neurogenesis, and white matter repair in the peri-infarct region after cerebral ischemia. EXPERIMENTAL PROCEDURE: The adult male rats were subjected to 2 h of middle cerebral artery occlusion. The rats were treated with 10 and 30 mg/kg OEA or vehicle daily starting from day 2 after ischemia induction until they were sacrificed. KEY RESULTS AND CONCLUSIONS: The results revealed that OEA increased cortical angiogenesis, neural progenitor cells (NPCs) proliferation, migration, and differentiation. OEA treatment enhanced the survival of newborn neurons and oligodendrogenesis, which eventually repaired the cortical neuronal injury and improved motor function after ischemic stroke. Meanwhile, OEA treatment promoted the differentiation of oligodendrocyte progenitor cells (OPCs) and oligodendrogenesis by activating the PPARα signaling pathway. Our results showed that OEA restores motor function by facilitating cortical angiogenesis, neurogenesis, and white matter repair in rats after ischemic stroke. Therefore, we demonstrate that OEA facilitates functional recovery after ischemic stroke and propose the hypothesis that the long-term application of OEA mitigates the disability after stroke.

Multifunctional Nanoplatform for NIR-II Imaging-Guided Synergistic Oncotherapy.

Tumors are a major public health issue of concern to humans, seriously threatening the safety of people's lives and property. With the increasing demand for early and accurate diagnosis and efficient treatment of tumors, noninvasive optical imaging (including fluorescence imaging and photoacoustic imaging) and tumor synergistic therapies (phototherapy synergistic with chemotherapy, phototherapy synergistic with immunotherapy, etc.) have received increasing attention. In particular, light in the near-infrared second region (NIR-II) has triggered great research interest due to its penetration depth, minimal tissue autofluorescence, and reduced tissue absorption and scattering. Nanomaterials with many advantages, such as high brightness, great photostability, tunable photophysical properties, and excellent biosafety offer unlimited possibilities and are being investigated for NIR-II tumor imaging-guided synergistic oncotherapy. In recent years, many researchers have tried various approaches to investigate nanomaterials, including gold nanomaterials, two-dimensional materials, metal sulfide oxides, polymers, carbon nanomaterials, NIR-II dyes, and other nanomaterials for tumor diagnostic and therapeutic integrated nanoplatform construction. In this paper, the application of multifunctional nanomaterials in tumor NIR-II imaging and collaborative therapy in the past three years is briefly reviewed, and the current research status is summarized and prospected, with a view to contributing to future tumor therapy.

Novel, Self-Distinguished, Dual Stimulus-Responsive Therapeutic Nanoplatform for Intracellular On-Demand Drug Release.

On-demand drug release nanoplatforms are promising alternative strategies for enhancing the therapeutic effect of cancer chemotherapy. However, these nanoplatforms still have many drawbacks including rapid blood clearance, nontargeted specificity, and a lack of immune escape function. Even worse, they are also hindered via the dosage-limiting toxicity of traditional chemotherapeutic drugs. Herein, both dual-functional mannose (enhances the antitumor activity of chemotherapeutic drugs and exhibits an innate affinity against the lectin receptor) and amphiphilic d-α-tocopheryl polyethylene glycol 1000 succinate were selected to be covalently linked via a redox-responsive monothioether linkage. The synthesized self-distinguished polymer (TSM), as a structural motif, can be self-assembled into nanoparticles (TSM NPs) in an aqueous solution, in which doxorubicin (DOX) is loaded by weak interactions (TSM-DOX NPs). These TSM-DOX NPs can provide targeted, on-demand drug release under dual stimuli from lysosomal acidity and glutathione (GSH). In addition, TSM-DOX NPs can be self-distinguished via tumor cells in vitro and specifically self-distinguished from the tumor site in vivo. Further in vitro and in vivo research consistently demonstrated that TSM-DOX NPs display highly synergistic chemotherapeutic effects. Taken together, the data show that the self-distinguished GSH-responsive polymer TSM has the potential to load various therapeutic agents.

Redox-Responsive and Dual-Targeting Hyaluronic Acid-Methotrexate Prodrug Self-Assembling Nanoparticles for Enhancing Intracellular Drug Self-Delivery.

The clinical translation of methotrexate (MTX) is limited because of low aqueous solubility, poor bioavailability, low uptake efficiency, and toxicity concerns. Herein, dual-acting MTX (not only targeting folate receptors but also killing cells via inhibition of intracellular folate metabolism) and hyaluronic acid (HA, targeting CD44 receptors) were selected to be covalently linked by the redox-responsive disulfide bond. The synthesized prodrug (HA-SS-MTX) as a molecular structural motif could self-assemble into simple yet multifunctional nanoparticles (HA-SS-MTX NPs) in aqueous solution. The HA-SS-MTX NPs displayed an average diameter of ∼110 nm with a uniformly spherical shape and maintained stability in different physiological media. Moreover, the HA-SS-MTX NPs could exhibit a sharp redox-dependent response for rapid structure disassembly and sequential MTX release compared to the redox-irresponsive group (HA-ADH-MTX NPs). Furthermore, the results of confocal microscopy and flow cytometry verified that the nanosystems were selectively uptaken by cancer cells via folate and CD44 receptor-mediated internalization through the dual-active targeting mechanism. In addition, HA-SS-MTX NPs could accumulate within tumor sites for a longer period. Notably, in vitro and in vivo antitumor results demonstrated that HA-SS-MTX NPs significantly promoted the death of cancer cells and enhanced the inhibition of tumor growth while reducing the toxicity as compared to MTX and HA-ADH-MTX NPs. Therefore, the smart HA-SS-MTX NPs as the simple and efficient platform have great potential in tumor-targeting drug delivery and therapy.

Multifunctional Nanosystem Based on Graphene Oxide for Synergistic Multistage Tumor-Targeting and Combined Chemo-Photothermal Therapy.

Locating nanomedicines at the active sites plays a pivotal role in the nanoparticle-based cancer therapy field. Herein, a multifunctional nanotherapeutic is designed by using graphene oxide (GO) nanosheets with rich carboxyl groups as the supporter for hyaluronic acid (HA)-methotrexate (MTX) prodrug modification via an adipicdihydrazide cross-linker, achieving synergistic multistage tumor-targeting and combined chemo-photothermal therapy. As a tumor-targeting biomaterial, HA can increase affinity of the nanocarrier toward CD44 receptor for enhanced cellular uptake. MTX, a chemotherapeutic agent, can also serve as a tumor-targeting enhancer toward folate receptor based on its similar structure with folic acid. The prepared nanosystems possess a sheet shape with a dynamic size of approximately 200 nm and pH-responsive drug release. Unexpectedly, the physiological stability of HA-MTX prodrug-decorated GO nanosystems in PBS, serum, and even plasma is more excellent than that of HA-decorated GO nanosystems, while both of them exhibit an enhanced photothermal effect than GO nanosheets. More importantly, because of good blood compatibility as well as reduced undesired interactions with blood components, HA-MTX prodrug-decorated GO nanosystems exhibited remarkably superior accumulation at the tumor sites by passive and active targeting mechanisms, achieving highly effective synergistic chemo-photothermal therapeutic effect upon near-infrared laser irradiation, efficient ablation of tumors, and negligible systemic toxicity. Hence, the HA-MTX prodrug-decorated hybrid nanosystems have a promising potential for synergistic multistage tumor-targeting therapy.

Research Progress of Polysaccharide-Gold Nanocomplexes in Drug Delivery.

Clinical drug administration aims to deliver drugs efficiently and safely to target tissues, organs, and cells, with the objective of enabling their therapeutic effects. Currently, the main approach to enhance a drug's effectiveness is ensuring its efficient delivery to the intended site. Due to the fact that there are still various drawbacks of traditional drug delivery methods, such as high toxicity and side effects, insufficient drug specificity, poor targeting, and poor pharmacokinetic performance, nanocarriers have emerged as a promising alternative. Nanocarriers possess significant advantages in drug delivery due to their size tunability and surface modifiability. Moreover, nano-drug delivery systems have demonstrated strong potential in terms of prolonging drug circulation time, improving bioavailability, increasing drug retention at the tumor site, decreasing drug resistance, as well as reducing the undesirable side effects of anticancer drugs. Numerous studies have focused on utilizing polysaccharides as nanodelivery carriers, developing delivery systems based on polysaccharides, or exploiting polysaccharides as tumor-targeting ligands to enhance the precision of nanoparticle delivery. These types of investigations have become commonplace in the academic literature. This review aims to elucidate the preparation methods and principles of polysaccharide gold nanocarriers. It also provides an overview of the factors that affect the loading of polysaccharide gold nanocarriers with different kinds of drugs. Additionally, it outlines the strategies employed by polysaccharide gold nanocarriers to improve the delivery efficiency of various drugs. The objective is to provide a reference for further development of research on polysaccharide gold nanodelivery systems.

Endogenous Fe2+-triggered self-targeting nanomicelles for self-amplifying intracellular oxidative stress.

BACKGROUND: Artesunate (ASA) acts as an •O2- source through the breakdown of endoperoxide bridges catalyzed by Fe2+, yet its efficacy in ASA-based nanodrugs is limited by poor intracellular delivery. METHODS: ASA-hyaluronic acid (HA) conjugates were formed from hydrophobic ASA and hydrophilic HA by an esterification reaction first, and then self-targeting nanomicelles (NM) were developed using the fact that the amphiphilic conjugates of ASA and HA are capable of self-assembling in aqueous environments. RESULTS: These ASA-HA NMs utilize CD44 receptor-mediated transcytosis to greatly enhance uptake by breast cancer cells. Subsequently, endogenous Fe2+ from the tumor catalyzes the released ASA to produce highly toxic •O2- radicals to kill tumor cells, although sustained tumor growth inhibition can be achieved via in vivo experiments. CONCLUSIONS: Self-targeting NMs represent a promising strategy for enhancing ASA-based treatments, leveraging clinically approved drugs to expedite drug development and clinical research in oncology.

Efficient Host Materials for Lithium-Sulfur Batteries: Ultrafine CoP Nanoparticles in Black Phosphorus-Carbon Composite.

The pursuit of efficient host materials to address the sluggish redox kinetics of sulfur species has been a longstanding challenge in advancing the practical application of lithium-sulfur batteries. In this study, amorphous carbon layer loaded with ultrafine CoP nanoparticles prepared by a one-step in situ carbonization/phosphating method to enhance the inhibition of 2D black phosphorus (BP) on LiPSs shuttle. The carbon coating layer facilitates accelerated electron/ion transport, enabling the active involvement of BP in the conversion of soluble lithium polysulfides (LiPSs). Concurrently, the ultra-fine CoP nanoparticles enhance the chemical anchoring ability and introduce additional catalytic sites. As a result, S@BP@C-CoP electrodes demonstrate exemplary cycling stability (with a minimal capacity decay of 0.054 % over 500 cycles at 1 C) and superior rate performance (607.1 mAh g-1 at 5 C). Moreover, at a sulfur loading of 5.5 mg cm-2, the electrode maintains an impressive reversible areal capacity of 5.45 mAh cm-2 after 50 cycles at 0.1 C. This research establishes a promising approach, leveraging black phosphorus-based materials, for developing high-efficiency Li-S batteries.

Mechanism of Self-Oxidative Copolymerization and its Application with Polydopamine-pyrrole Nano-copolymers.

Currently, the copolymer of dopamine (DA) and pyrrole (PY) via chemical and electrochemical oxidation usually requires additional oxidants, and lacks flexibility in regulating the size and morphology, thereby limiting the broad applications of DA-PY copolymer in biomedicine. Herein, the semiquinone radicals produced by the self-oxidation of DA is ingeniously utilized as the oxidant to initiate the following copolymerization with PY, and a series of quinone-rich polydopamine-pyrrole copolymers (PDAm -nPY) with significantly enhanced absorption in near-infrared (NIR) region without any additional oxidant assistance is obtained. Moreover, the morphology and size of PDAm -nPY can be regulated by changing the concentration of DA and PY, thereby optimizing nanoscale PDA0.05 -0.15PY particles (≈ 150 nm) with excellent NIR absorption and surface modification activity are successfully synthesized. Such PDA0.05 -0.15PY particles show effective photoacoustic (PA) imaging and photothermal therapy (PTT) against 4T1 tumors in vivo. Furthermore, other catechol derivatives can also copolymerize with PY under the same conditions. This work by fully utilizing the semiquinone radical active intermediates produced through the self-oxidation of DA reduces the dependence on external oxidants in the synthesis of composite materials and predigests the preparation procedure, which provides a novel, simple, and green strategy for the synthesis of other newly catechol-based functional copolymers.

Application of Nanomaterial-Based Sonodynamic Therapy in Tumor Therapy.

Sonodynamic therapy (SDT) has attracted significant attention in recent years as it is an innovative approach to tumor treatment. It involves the utilization of sound waves or ultrasound (US) to activate acoustic sensitizers, enabling targeted drug release for precise tumor treatment. This review aims to provide a comprehensive overview of SDT, encompassing its underlying principles and therapeutic mechanisms, the applications of nanomaterials, and potential synergies with combination therapies. The review begins by introducing the fundamental principle of SDT and delving into the intricate mechanisms through which it facilitates tumor treatment. A detailed analysis is presented, outlining how SDT effectively destroys tumor cells by modulating drug release mechanisms. Subsequently, this review explores the diverse range of nanomaterials utilized in SDT applications and highlights their specific contributions to enhancing treatment outcomes. Furthermore, the potential to combine SDT with other therapeutic modalities such as photothermal therapy (PTT) and chemotherapy is discussed. These combined approaches aim to synergistically improve therapeutic efficacy while mitigating side effects. In conclusion, SDT emerges as a promising frontier in tumor treatment that offers personalized and effective treatment options with the potential to revolutionize patient care. As research progresses, SDT is poised to play a pivotal role in shaping the future landscape of oncology by providing patients with a broader spectrum of efficacious and tailored treatment options.

Neuroprotective effects of anti-TRAIL-ICG nanoagent and its multimodal imaging evaluation in cerebral ischemia-reperfusion injury.

Cerebral ischemia-reperfusion injury (CIRI) is a major challenge to neuronal survival in acute ischemic stroke (AIS). However, effective neuroprotective agents remain to be developed for the treatment of CIRI. In this work, we have developed an Anti-TRAIL protein-modified and indocyanine green (ICG)-responsive nanoagent (Anti-TRAIL-ICG) to target ischemic areas and then reduce CIRI and rescue the ischemic penumbra. In vitro and in vivo experiments have demonstrated that the carrier-free nanoagent can enhance drug transport across the blood-brain barrier (BBB) in stroke mice, exhibiting high targeting ability and good biocompatibility. Anti-TRAIL-ICG nanoagent played a better neuroprotective role by reducing apoptosis and ferroptosis, and significantly improved ischemia-reperfusion injury. Moreover, the multimodal imaging platform enables the dynamic in vivo examination of multiple morphofunctional information, so that the dynamic molecular events of nanoagent can be detected continuously and in real time for early treatment in transient middle cerebral artery occlusion (tMCAO) models. Furthermore, it has been found that Anti-TRAIL-ICG has great potential in the functional reconstruction of neurovascular networks through optical coherence tomography angiography (OCTA). Taken together, our work effectively alleviates CIRI after stoke by blocking multiple cell death pathways, which offers an innovative strategy for harnessing the apoptosis and ferroptosis against CIRI.

Bioengineered nanogenerator with sustainable reactive oxygen species storm for self-reinforcing sono-chemodynamic oncotherapy.

Oxidative stress-based antitumor modalities derived from reactive oxygen species (ROS) storms have attracted increasing attention. Nevertheless, low delivery efficiency, poor selectivity, hypoxia and overexpressed glutathione (GSH) have severely restricted the sustainable generation of the ROS storm in tumor cells. Herein, we design a bioengineered nanogenerator by coordination-driven co-assembly of sonosensitizer indocyanine green (ICG), Fenton-like agent copper ion (CuⅡ) and mitochondrial respiratory inhibitor metformin (MET), which is then camouflaged by a cancer cytomembrane to induce a sustainable intracellular ROS storm for on-demand self-reinforcing sono-chemodynamic oncotherapy. Such a nanogenerator with a core-shell structure, suitable diameter and outstanding stability can efficiently accumulate in tumor regions and then internalize into tumor cells through the camouflaging and homologous targeting strategy of the cancer cytomembrane. The nanogenerator shows an exceptional instability under the triple stimulations of acidic lysosomes, overexpressed GSH and ultrasound (US) radiation, thereby resulting in the rapid disassembly and burst drug release. Interestingly, the released MET significantly enhances the sonodynamic therapy (SDT) efficacy of the released ICG by inhibiting mitochondrial respiration and meanwhile the released CuⅡ obviously reduces ROS elimination by downregulating overexpressed GSH for self-amplifying and self-protecting the intracellular ROS storm. Moreover, such a nanogenerator almost completely achieves the tumor ablation in vivo in a single therapy cycle. Taken together, our bioengineered nanogenerator with a sustainable ROS storm can provide a promising strategy for ROS storm-based oncotherapy.

Recent Advances in Targeted Drug Delivery Strategy for Enhancing Oncotherapy.

Targeted drug delivery is a precise and effective strategy in oncotherapy that can accurately deliver drugs to tumor cells or tissues to enhance their therapeutic effect and, meanwhile, weaken their undesirable side effects on normal cells or tissues. In this research field, a large number of researchers have achieved significant breakthroughs and advances in oncotherapy. Typically, nanocarriers as a promising drug delivery strategy can effectively deliver drugs to the tumor site through enhanced permeability and retention (EPR) effect-mediated passive targeting and various types of receptor-mediated active targeting, respectively. Herein, we review recent targeted drug delivery strategies and technologies for enhancing oncotherapy. In addition, we also review two mainstream drug delivery strategies, passive and active targeting, based on various nanocarriers for enhancing tumor therapy. Meanwhile, a comparison and combination of passive and active targeting are also carried out. Furthermore, we discuss the associated challenges of passive and active targeted drug delivery strategies and the prospects for further study.

Pyrrole-Doped Polydopamine-Pyrrole (PDA-nPY) Nanoparticles with Tunable Size and Improved NIR Absorption for Photothermal Therapy.

Polydopamine (PDA) as a melanin-like biomimetic material with excellent biocompatibility, full spectrum light absorption capacity and antioxidation property has been extensively applied in the biomedical field. Based on the high reactivity of dopamine (DA), exploiting new strategies to fabricate novel PDA-based nano-biomaterials with controllable size and improved performance is valuable and desirable. Herein, we reported a facile way to synthesize pyrrole-doped polydopamine-pyrrole nanoparticles (PDA-nPY NPs) with tunable size and enhanced near-infrared (NIR) absorption capacity through self-oxidative polymerization of DA with PY in an alkaline ethanol/H2O/NH4OH solution. The PDA-nPY NPs maintain excellent biocompatibility and surface reactivity as PDA. By regulating the volume of added PY, PDA-150PY NPs with a smaller size (<100 nm) and four-fold higher absorption intensity at 808 nm than that of PDA can be successfully fabricated. In vitro and in vivo experiments effectively further demonstrate that PDA-150PY NPs can effectively inhibit tumor growth and completely thermally ablate a tumor. It is believed that these PY doped PDA-nPY NPs can be a potential photothermal (PT) agent in biomedical application.

Antiovarian cancer mechanism of esculetin: inducing G0/G1 arrest and apoptosis via JAK2/STAT3 signalling pathway.

OBJECTIVES: Esculetin is a coumarin derivative, which is extracted from the dried barks of fraxinus chinensis Roxb. Although it is reported esculetin possesses multiple pharmacological activities, its associated regulatory mechanism on ovarian cancer isn't well investigated. METHODS: Cytotoxicity is evaluated by MTT, clonogenic and living/dead cells staining assays. Migration and invasion effects are investigated by wound healing, and transwell assays. The effect of cell cycle and apoptosis are analyzed by flow cytometry and western blotting. Mitochondrial membrane potential and intracellular reactive oxygen species (ROS) is assessed by fluorescence microscope. Analysis of animal experiments are carried out by various pathological section assays. KEY FINDINGS: Esculetin exerts an anti- ovarian cancer effect. It is found that apoptosis induction is promoted by the accumulation of excessive ROS and inhibition of JAK2/STAT3 signalling pathway. In addition, exposure to esculetin leads to the cell viability reduction, migration and invasion capability decrease and G0/G1 phase cell cycle arrest induced by down-regulating downstream targets of STAT3. In vivo experimental results also indicate esculetin can inhibit tumour growth of mice. CONCLUSIONS: Our study provides some strong evidences to support esculetin as a potential anti-cancer agent in ovarian cancer.

Platinum-Coordinated Engineered Nanoreactors with O2 Self-Amplificationand On-Demand Cascade Chemo-Drug Synthesis for Self-Reinforcing Hypoxic Oncotherapy.

How to efficiently synthesize toxic chemo-drugs in the hypoxia tumor microenvironment still faces a huge challenge. Herein, we have tailored engineered vehicle-free nanoreactors by coordination-driven co-assembly of photosensitizer indocyanine green (ICG), transition metal platinum (Pt), and nontoxic 1,5-dihydroxynaphthalene (DHN) to self-amplify O2 and cascade chemo-drug synthesis in tumor cells for self-reinforcing hypoxic oncotherapy. Once vehicle-free nanoreactors are internalized into tumor cells, they show a serious instability that results in rapid disassembly and on-demand drug release under the stimuli of acidic lysosome and laser radiation. Notably, the released Pt can efficiently decompose the endogenous hydrogen peroxide (H2O2) into O2 to alleviate tumor hypoxia, which is conducive to enhancing the photodynamic therapy (PDT) efficiency of the released ICG. Complementarily, a large amount of the 1O2 generated by PDT can efficiently oxidize the released nontoxic DHN into the highly toxic chemo-drug juglone. Therefore, such vehicle-free nanoreactors can achieve intracellular on-demand cascade chemo-drug synthesis and self-reinforce photo-chemotherapeutic efficacy on the hypoxic tumor. On the whole, such a simple, flexible, efficient, and nontoxic therapeutic strategy will broaden the study of on-demand chemo-drug synthesis and hypoxic oncotherapy.

TME-triggered copper-coordinated engineered programmable nanogenerators for on-demand cascade-amplifying oxidative stress.

Although oxidative stress-based antitumor modality derived from reactive oxygen species (ROS) storm has attracted considerable attention in copper-based nanomaterials, its efficiency is still weakened by the insufficient hydrogen peroxide (H2O2) and overexpressed glutathione (GSH) in a tumor microenvironment (TME). In view of this, we designed an engineered programmable spike-like nanogenerator via the coordination-driven co-assembly of Evans Blue (EB), copper ions (CuII), and 5-hydroxy-p-naphthoquinone (HND). For programmable nanogenerators, the introduction of EB as a stabilizer-like component can not only adjust its morphology but also achieve its visual tracking. Interestingly, such programmable nanogenerators can be efficiently enriched in tumor regions and then internalized into tumor cells due to ECH with spike-like morphology. Notably, once the nanogenerator is disintegrated and burst to release the drug upon acidic lysosome and endogenous GSH triggering, the released HND can not only efficiently amplify endogenous H2O2 by intracellular oxidoreductases but also down-regulate the peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin 1) activity. In addition, the released CuII ions can efficiently catalyze the degradation of the endogenous H2O2 to amplify hydroxyl radicals (˙OH) and down-regulate the overexpressed GSH to reduce ˙OH elimination for on-demand cascade-amplifying oxidative stress. Importantly, such programmable nanogenerators show an excellent antitumor effect via down-regulating the Pin 1 activity and cascade-amplifying oxidative stress. In this study, we propose a spatiotemporally programmable cascade nanogenerator for oxidative stress-based antitumor therapy.

Trojan-Horse Diameter-Reducible Nanotheranostics for Macroscopic/Microscopic Imaging-Monitored Chemo-Antiangiogenic Therapy.

Although nanotheranostics have displayed striking potential toward precise nanomedicine, their targeting delivery and tumor penetration capacities are still impeded by several biological barriers. Besides, the current antitumor strategies mainly focus on killing tumor cells rather than antiangiogenesis. Enlightened by the fact that the smart transformable self-targeting nanotheranostics can enhance their targeting efficiency, tumor penetration, and cellular uptake, we herein report carrier-free Trojan-horse diameter-reducible metal-organic nanotheranostics by the coordination-driven supramolecular sequential co-assembly of the chemo-drug pemetrexed (PEM), transition-metal ions (FeIII), and antiangiogenesis pseudolaric acid B. Such nanotheranostics with both a high dual-drug payload efficiency and outstanding physiological stability are responsively decomposed into numerous ultra-small-diameter nanotheranostics under stimuli of the moderate acidic tumor microenvironment and then internalized into tumor cells through tumor-receptor-mediated self-targeting, synergistically enhancing tumor penetration and cellular uptake. Besides, such nanotheranostics enable visualization of self-targeting capacity under the macroscopic monitor of computed tomography/magnetic resonance imaging, thereby realizing efficient oncotherapy. Moreover, tumor microvessels are precisely monitored by optical coherence tomography angiography/laser speckle imaging during chemo-antiangiogenic therapy in vivo, visually verifying that such nanotheranostics possess an excellent antiangiogenic effect. Our work will provide a promising strategy for further tumor diagnosis and targeted therapy.

Copper-based theranostic nanocatalysts for synergetic photothermal-chemodynamic therapy.

Chemodynamic therapy (CDT) has aroused extensive attention as a potent therapeutic modality. However, its practical application is severely restricted by the strong acidity requirement for Fenton reaction and upregulated antioxidant defense within metastatic breast cancer. Herein, a copper-based single-site nanocatalyst functionalized with carbonic anhydrase inhibitor (CAI) was constructed for magnetic resonance/photoacoustic imaging (MRI/PA)-guided synergetic photothermal therapy (PTT) and CDT. Once reaching tumor sites, the nanocatalyst can be recognized by tumor cell membranes-overexpressed carbonic anhydrase IX (CA IX). Subsequently, the single-site CuII can be reduced to CuI by the tumor-overexpressed glutathione (GSH), which simultaneously impaired the tumor antioxidant defense system and triggered CAI release for inducing intracellular H+ accumulation. Further, the decreased intracellular pH can accelerate the nanocatalyst biodegradation to release more CuII and CAI to participate in next-cycle GSH-depletion and cytoplasm acidification, respectively, thereby continuously supplying CuI and H+ for self-cyclically amplified CDT. Upon laser irradiation, the nanocatalyst can generate local heat, which not only permits PTT but also enhances the nanocatalyst-mediated CDT. Moreover, the suppression of CA IX can hinder the tumor extracellular matrix degradation to prevent tumor metastasis. Overall, this work highlighted the great application prospect in enhancing CDT via tumor acidic/redox microenvironment remodeling, and provides an insightful paradigm for inhibiting breast cancer metastasis. STATEMENT OF SIGNIFICANCE: The practical application of chemodynamic therapy (CDT) is severely restricted by the strong acidity requirement for Fenton reaction and upregulated antioxidant defense within cancer. Herein, we developed a carbonic anhydrase inhibitor (CAI)-functionalized Cu-based nanocatalyst. Once reaching tumor sites, the CuII can be reduced to CuI by the tumor-overexpressed glutathione (GSH), which simultaneously impaired the tumor antioxidant system and triggered CAI release for inducing intracellular H+ accumulation. Further, the decreased intracellular pH can accelerate the nanocatalyst biodegradation to release more CuII and CAI to participate in next-cycle GSH-depletion and cytoplasm acidification, respectively, thus continuously supplying CuI and H+ for self-cyclically amplified CDT. Upon laser irradiation, the nanocatalyst not only permits PTT but also enhances the CDT.