Zwitterion-Based Hydrogen Sulfide Nanomotors Induce Multiple Acidosis in Tumor Cells by Destroying Tumor Metabolic Symbiosis

Dual responsive drug-loaded nanomotor based on zwitterionic materials for the treatment of peritoneal metastatic cancer

Innovative treatments for peritoneal metastatic cancer have attracted widespread attention from researchers. Here, we propose a drug-loaded nanomotor (PSBMA/l-Arg/DOX, PLD) based on zwitterionic materials for the treatment of peritoneal metastatic cancer through intraperitoneal injection. Zwitterionic polymer nanocarriers (PSBMA NPs) are obtained by radical polymerization with zwitterionic SBMA as the polymerization monomer and N,N'-Bis(acryloyl)cystamine (BAC) as the cross-linking agent. The zwitterionic substrate of this nanomotor has the ability to resist non-specific protein adsorption in ascites. The loaded l-arginine enables the nanomotor to have the ability to chemotaxis towards high concentrations of ROS/iNOS in tumors and be catalyzed to produce NO, achieving deep penetration into tumor tissue. Furthermore, the disulfide bond (SS) carried by the crosslinking agent used in the preparation of the nanomotor can respond to the high expression of reducing glutathione in the tumor microenvironment and undergo degradation, releasing a large amount of loaded drug DOX. Cell and animal disease model experiments confirme the good therapeutic effect of this drug-loaded nanomotor, providing new therapeutic concepts and strategies for the treatment of peritoneal metastatic cancer.

Enzymatic nanomotors with chemotaxis for product-based cancer therapy

The development of an intelligent nanomotor system holds great promise for enhancing the efficiency and effectiveness of antitumor therapy. Leveraging the overexpressed substances in the tumor microenvironment as propellants and chemotactic factors for enzyme-powered nanomotors represents a versatile and compelling approach. Herein, a plasma amine oxidase (PAO)-based chemotactic nanomotor system has been successfully developed, with the ability to enzymatically produce toxic acrolein and H2O2 from the upregulated polyamines (PAs) in the tumor microenvironment for active tumor therapy. Zwitterionic polymeric nanoparticles with superior biocompatibility are synthesized, followed by PAO modification via electrostatic interactions. As expected, the resulting nanomotor system exhibits positive chemotaxis toward PAs concentration gradient. Upon reaching the tumor region, our nanomotors, actuated by the tumor microenvironmental PAs, effectively enhance diffusion and enable deep penetration into the tumor site. This leads to the induction of tumor apoptosis and simultaneous inhibition of tumor invasion and migration by decomposing PAs into toxic products. By smartly utilizing the consumption of these local chemotactic factors and their enzymatic products, our nanomotor system provides a versatile and intelligent platform for active and enhanced tumor therapy.

Hydrogen sulfide-generating semiconducting polymer nanoparticles for amplified radiodynamic-ferroptosis therapy of orthotopic glioblastoma

A variety of therapeutic strategies are available to treat glioblastoma (GBM), but the tumor remains one of the deadliest due to its aggressive invasiveness, restrictive blood-brain barrier (BBB), and exceptional resistance to drugs. In this study, we present a hydrogen sulfide (H2S)-generating semiconducting polymer nanoparticle (PFeD@Ang) for amplified radiodynamic-ferroptosis therapy of orthotopic glioblastoma. Our results show that in an acidic tumor microenvironment (TME), H2S donors produce large amounts of H2S, which inhibits mitochondrial respiration and alleviates cellular hypoxia, thus enhancing the radiodynamic effect during X-ray irradiation; meanwhile, Fe3+ is reduced to Fe2+ by tannic acid in an acidic TME, which promotes an iron-dependent cell death process in tumors. H2S facilitates the ferroptosis process by increasing the local H2O2 concentration via inhibiting catalase activity. This kind of amplified radiodynamic-ferroptosis therapeutic strategy could remarkably inhibit glioma progression in an orthotopic GBM mouse model. Our study demonstrates the potential of PFeD@Ang for GBM treatment via targeted delivery and combinational therapeutic actions of RDT and ferroptosis therapy.

Bottle Nanomotors Amplify Tumor Oxidative Stress for Enhanced Calcium Overload/Chemodynamic Therapy

Developing multifunctional, stimuli-responsive nanomedicine is intriguing because it has the potential to effectively treat cancer. Yet, poor tumor penetration of nanodrugs results in limited antitumor efficacy. Herein, an oxygen-driven silicon-based nanomotor (Si-motor) loaded with MnO and CaO2 nanoparticles is developed, which can move in tumor microenvironment (TME) by the cascade reaction of CaO2 and MnO. Under acidic TME, CaO2 reacts with acid to release Ca2+ to induce mitochondrial damage and simultaneously produces O2 and H2O2, when the loaded MnO exerts Fenton-like activity to produce ·OH and O2 based on the produced H2O2. The generated O2 drives Si-motor forward, thus endowing active delivery capability of the formed motors in TME. Meanwhile, MnO with glutathione (GSH) depletion ability further prevents reactive oxygen species (ROS) from being destroyed. Such TME actuated Si-motor with enhanced cellular uptake and deep penetration provides amplification of synergistic oxidative stresscaused by intracellular Ca2 + overloading, GSH depletion induced by Mn2+, and Mn2+ mediated chemodynamic treatment (CDT), leading to excellent tumor cell death. The created nanomotor may offer an effective platform for active synergistic cancer treatment.

Polysaccharide Based Self-Driven Tubular Micro/Nanomotors as a Comprehensive Platform for Quercetin Loading and Anti-inflammatory Function

Quercetin (QR) is a natural flavonoid with strong anti-inflammatory properties, but it suffers from poor water solubility and bioavailability. Micro/nanomotors (NMs) are tiny devices that convert external energy or chemical fuels into an autonomous motion. They are characterized by their small size, rapid movement, and self-assembly capabilities, which can enhance the delivery of bioactive ingredients. The study synthesized natural polysaccharide-based nanotubes (NTs) using a layer-by-layer self-assembly method and combined with urease (Ure), glucose oxidase (GOx), and Fe3O4 to create three types of NMs. These NMs were well-dispersed and biocompatible. In vitro experiments showed that NMs-Fe3O4 has excellent photothermal conversion properties and potential for use in photothermal therapy. Cellular inflammation model results demonstrated that QR-loaded NMs were not only structurally stable but also improved bioavailability and effectively inhibited the release of inflammatory mediators such as IL-1β and IL-6, providing a safe and advanced carrier system for the effective use of bioactive components in food.

NO- and H2S- releasing nanomaterials: A crosstalk signaling pathway in cancer

The gasotransmitters nitric oxide (NO) and hydrogen sulfide (H2S) play important roles not only in maintaining physiological functions, but also in pathological conditions and events. Importantly, these molecules show a complex interplay in cancer biology, demonstrating both tumor-promoting and anti-tumor activities depending on their concentration, flux, and the environmental redox state. Additionally, various cell types respond differently to NO and H2S. These gasotransmitters can be synergistically combined with traditional anticancer treatments such as radiotherapy, immunotherapy, chemotherapy, and phototherapy. Notably, NO, and more recently H2S, have been shown to reverse multidrug resistance. Nanomaterials to deliver NO donors and, to a lesser extent, H2S donors, have emerged as a promising approach for targeted delivery of these gasotransmitters. Nanotechnology has advanced the delivery of anticancer drugs, enhancing efficiency and reducing side effects on non-cancerous cells. This review highlights recent progress in the design of NO and H2S-releasing nanomaterials for anticancer effects. It also explores the interactions between NO and H2S, which are crucial for developing combined therapies and nanomedicines with minimal side effects.

Enhanced Tumor Site Accumulation and Therapeutic Efficacy of Extracellular Matrix-Drug Conjugates Targeting Tumor Cells

The extracellular matrix (ECM) engages in regulatory interactions with cell surface receptors through its constituent proteins and polysaccharides. Therefore, nano-sized extracellular matrix conjugated with doxorubicin (DOX) is utilized to produce extracellular matrix-drug conjugates (ECM-DOX) tailored for targeted delivery to cancer cells. The ECM-DOX nanoparticles exhibit rod-like morphology, boasting a commendable drug loading capacity of 4.58%, coupled with acid-sensitive drug release characteristics. Notably, ECM-DOX nanoparticles enhance the uptake by tumor cells and possess the ability to penetrate endothelial cells and infiltrate tumor multicellular spheroids. Mechanistic insights reveal that the internalization of ECM-DOX nanoparticle is facilitated through clathrin-mediated endocytosis and macropinocytosis, intricately involving hyaluronic acid receptors and integrins. Pharmacokinetic assessments unveil a prolonged blood half-life of ECM-DOX nanoparticles at 3.65 h, a substantial improvement over the 1.09 h observed for free DOX. A sustained accumulation effect of ECM-DOX nanoparticles at tumor sites, with drug levels in tumor tissues surpassing those of free DOX by several-fold. The profound therapeutic impact of ECM-DOX nanoparticles is evident in their notable inhibition of tumor growth, extension of median survival time in animals, and significant reduction in DOX-induced cardiotoxicity. The ECM platform emerges as a promising carrier for avant-garde nanomedicines in the realm of cancer treatment.

Dual-enzyme inhibiting nanomedicines for enhanced cancer chemodynamic therapy by inducing intratumoral acidosis

Deficiency of endogenous hydrogen peroxide and insufficient intracellular acidity are usually two important factors limiting chemodynamic therapy (CDT). Here we report a glutathione-responsive nanomedicine that can provide a suitable environment for CDT by inhibiting dual-enzymes simultaneously. The nanomedicine is constructed by encapsulation of a novel hydrogen sulfide donor in nanomicelle assembled by glutathione-responsive amphiphilic polymer. In response to intracellular glutathione, the nanomedicine can efficiently release the active ingredients hydrogen sulfide, carbonic anhydrase inhibitor and ferrocene. The hydrogen sulfide can increase the concentrations of hydrogen peroxide and lactic acid by inhibiting catalase and enhancing glycolysis. The carbonic anhydrase inhibitor can further induce intratumoral acidosis by inhibiting the function of carbonic anhydrase IX. Therefore, the nanomedicine can provide more efficient reaction conditions for the ferrocene-mediated Fenton reaction to generate abundant toxic hydroxyl radicals. In vivo results show that the combination of enhanced CDT and acidosis can effectively inhibit tumor growth. This design of nanomedicine provides a promising dual-enzyme inhibiting strategy to enhance antitumor efficacy of CDT.

Tofacitinib Citrate Coordination-Based Dual-Responsive/Scavenge Nanoplatform Toward Regulate Colonic Inflammatory Microenvironment for Relieving Colitis

Ulcerative colitis is an inflammation of the colon characterized by immune dysregulation and intestinal inflammation. Developing safe oral nanomedicines that suppress intestinal inflammation, while modulating colonic inflammatory microenvironment by scavenging reactive oxygen species (ROS) and hydrogen sulfide (H2S) is crucial for the effective treatment of colitis. Here, the tofacitinib citrate and copper coordination-based nanoparticle (TF-Cu nanoparticle, T-C) to dual-scavenge ROS and H2S by coordination competition is synthesized. Moreover, the coordination of T-C using computer simulation is explored. To enhance the acid stability and inflammatory targeting of T-C, it is encapsulated with hyaluronic acid-modified chitosan, along with a calcium pectinate coating (T-C@HP). Owing to the dual pH/pectinase-responsive characteristics of T-C@HP, the nanoplatform can target inflamed colonic lesions, inhibiting phosphorylated Janus kinase 1. Furthermore, T-C@HP scavenges ROS and H2S, as well as increases NADPH levels, which is investigated by combining biosensor (HyPer7 and iNap1/c) and chemical probes. T-C@HP also alleviates colitis by regulating the colonic inflammatory microenvironment through multiple processes, including the modulation of apoptosis, macrophage polarization, tight junction, mucus layer, and intestinal flora. Complemented by satisfactory anti-inflammatory and biosafety results, this nanoplatform represents a promising, effective, and safe treatment option for colitis patients.

Sunlight-triggered prebiotic nanomotors for inhibition and elimination of pathogen and biofilm in aquatic environment

Pathogen contamination in drinking water sources causes waterborne infectious diseases, seriously threatening human health. Nowadays, stimuli-responsive self-propelled nanomotors are appealing therapeutic agents for antibacterial therapy in vivo. However, achieving water disinfection using these nanobots is still a great challenge. Herein, we report on prebiotic galactooligosaccharide-based nanomotors for sunlight-regulated water disinfection. The nanomotors can utilize galactooligosaccharide-based N-nitrosamines as sunlight-responsive fuels for the spontaneous production of antibacterial nitric oxide. Such a solar-to-chemical energy conversion would power the nanomotors for self-diffusiophoresis, which could promote the diffusion of the nanomotors in water and their penetration in the biofilm, significantly enhancing the inhibition and elimination of the pathogens and their biofilms in aquatic environments. After water treatments, the prebiotic-based residual disinfectants can be selectively utilized by beneficial bacteria to effectively relieve safety risks to the environment and human health. The low-energy-cost, green and potent antibacterial nanobots show promising potential in water disinfection.

Hydrogen Sulfide can Scavenge Free Radicals to Improve Spinal Cord Injury by Inhibiting the p38MAPK/mTOR/NF-κB Signaling Pathway

Spinal cord injury (SCI) causes irreversible cell loss and neurological dysfunctions. Presently, there is no an effective clinical treatment for SCI. It can be the only intervention measure by relieving the symptoms of patients such as pain and fever. Free radical-induced damage is one of the validated mechanisms in the complex secondary injury following primary SCI. Hydrogen sulfide (H2S) as an antioxidant can effectively scavenge free radicals, protect neurons, and improve SCI by inhibiting the p38MAPK/mTOR/NF-κB signaling pathway. In this report, we analyze the pathological mechanism of SCI, the role of free radical-mediated the p38MAPK/mTOR/NF-κB signaling pathway in SCI, and the role of H2S in scavenging free radicals and improving SCI.

Mito-Specific Nutri-Hijacker Synergizing Mitochondrial Metabolism and Glycolysis Intervention for Enhanced Antitumor Bioenergetic Therapy

Metabolic rewiring, a dynamic metabolic phenotype switch, confers that tumors exist and proliferate after fitness (or preadaptation) in harsh environmental conditions. Glycolysis deprivation was considered to be a tumor's metabolic Achilles heel. However, metabolic configuration can flexibly retune the mitochondrial metabolic ability when glycolysis is scared, potentially resulting in more aggressive clones. To address the challenge of mitochondrial reprogramming, an antiglycolytic nanoparticle (GRPP NP) containing a novel mitochondrial-targeted reactive oxygen species (ROS) generator (diIR780) was prepared to hijack glucose and regulate mitochondria, thus completely eliminating tumorigenic energy sources. In this process, GRPP NPs@diIR780 can catalyze endogenous glucose, leading to significantly suppressed glycolysis. Moreover, diIR780 can be released and selectively accumulated around mitochondria to generate toxic ROS. These combined effects, in turn, can hamper mitochondrial metabolism pathways, which are crucial for driving tumor progression. This synchronous intervention strategy enables utter devastation of metabolic rewiring, providing a promising regiment to eradicate tumor lesions without recurrence.

H2S-Powered Nanomotors for Active Therapy of Tumors by Inducing Ferroptosis and Lactate-Pyruvate Axis Disorders

Disruption of the symbiosis of extra/intratumoral metabolism is a good strategy for treating tumors that shuttle resources from the tumor microenvironment. Here, we report a precision treatment strategy for enhancing pyruvic acid and intratumoral acidosis to destroy tumoral metabolic symbiosis to eliminate tumors; this approach is based on PEGylated gold and lactate oxidase-modified aminated dendritic mesoporous silica with lonidamine and ferrous sulfide loading (PEG-Au@DMSNs/FeS/LND@LOX). In the tumor microenvironment, LOX oxidizes lactic acid to produce pyruvate, which represses tumor cell proliferation by inhibiting histone gene expression and induces ferroptosis by partial histone monoubiquitination. In acidic tumor conditions, the nanoparticles release H2S gas and Fe2+ ions, which can inhibit catalase activity to promote the Fenton reaction of Fe2+, resulting in massive ·OH production and ferroptosis via Fe3+. More interestingly, the combination of H2S and LND (a monocarboxylic acid transporter inhibitor) can cause intracellular acidosis by lactate, and protons overaccumulate in cells. Multiple intracellular acidosis is caused by lactate-pyruvate axis disorders. Moreover, H2S provides motive power to intensify the shuttling of nanoparticles in the tumor region. The findings confirm that this nanomedicine system can enable precise antitumor effects by disrupting extra/intratumoral metabolic symbiosis and inducing ferroptosis and represents a promising active drug delivery system candidate for tumor treatment.

Urease-powered nanobots for radionuclide bladder cancer therapy

Bladder cancer treatment via intravesical drug administration achieves reasonable survival rates but suffers from low therapeutic efficacy. To address the latter, self-propelled nanoparticles or nanobots have been proposed, taking advantage of their enhanced diffusion and mixing capabilities in urine when compared with conventional drugs or passive nanoparticles. However, the translational capabilities of nanobots in treating bladder cancer are underexplored. Here, we tested radiolabelled mesoporous silica-based urease-powered nanobots in an orthotopic mouse model of bladder cancer. In vivo and ex vivo results demonstrated enhanced nanobot accumulation at the tumour site, with an eightfold increase revealed by positron emission tomography in vivo. Label-free optical contrast based on polarization-dependent scattered light-sheet microscopy of cleared bladders confirmed tumour penetration by nanobots ex vivo. Treating tumour-bearing mice with intravesically administered radio-iodinated nanobots for radionuclide therapy resulted in a tumour size reduction of about 90%, positioning nanobots as efficient delivery nanosystems for bladder cancer therapy.

Autonomous Nanorobots as Miniaturized Surgeons for Intracellular Applications

Artificial nanorobots have emerged as promising tools for a wide range of biomedical applications, including biosensing, detoxification, and drug delivery. Their unique ability to navigate confined spaces with precise control extends their operational scope to the cellular or subcellular level. By combining tailored surface functionality and propulsion mechanisms, nanorobots demonstrate rapid penetration of cell membranes and efficient internalization, enhancing intracellular delivery capabilities. Moreover, their robust motion within cells enables targeted interactions with intracellular components, such as proteins, molecules, and organelles, leading to superior performance in intracellular biosensing and organelle-targeted cargo delivery. Consequently, nanorobots hold significant potential as miniaturized surgeons capable of directly modulating cellular dynamics and combating metastasis, thereby maximizing therapeutic outcomes for precision therapy. In this review, we provide an overview of the propulsion modes of nanorobots and discuss essential factors to harness propulsive energy from the local environment or external power sources, including structure, material, and engine selection. We then discuss key advancements in nanorobot technology for various intracellular applications. Finally, we address important considerations for future nanorobot design to facilitate their translation into clinical practice and unlock their full potential in biomedical research and healthcare.

Design and Fabrication of Environmentally Responsive Nanoparticles for the Diagnosis and Treatment of Atherosclerosis

Cardiovascular disease poses a significant threat to human health in today's society. A major contributor to cardiovascular disease is atherosclerosis (AS). The development of plaque in the affected areas involves a complex pathological environment, and the disease progresses rapidly. Nanotechnology, combined with emerging diagnostic and treatment methods, offers the potential for the management of this condition. This paper presents the latest advancements in environment-intelligent responsive controlled-release nanoparticles designed specifically for the pathological environment of AS, which includes characteristics such as low pH, high reactive oxygen species levels, high shear stress, and multienzymes. Additionally, the paper summarizes the applications and features of nanotechnology in interventional therapy for AS, including percutaneous transluminal coronary angioplasty and drug-eluting stents. Furthermore, the application of nanotechnology in the diagnosis of AS shows promising real-time, accurate, and continuous effects. Lastly, the paper explores the future prospects of nanotechnology, highlighting the tremendous potential in the diagnosis and treatment of atherosclerotic diseases, especially with the ongoing development in nano gas, quantum dots, and Metal-Organic Frameworks materials.

A H2 S-Generated Supramolecular Photosensitizer for Enhanced Photodynamic Antibacterial Infection and Relieving Inflammation

Photodynamic therapy (PDT) is a promising treatment against bacteria-caused infections. By producing large amounts of reactive oxygen species (ROS), PDT can effectively eliminate pathogenic bacteria, without causing drug resistance. However, excessive ROS may also impose an oxidative stress on surrounding tissues, resulting in local inflammation. To avoid this major drawback and limit pro-inflammation during PDT, this work prepared a supramolecular photosensitizer (TPP-CN/CP5) based on host-guest interactions between a cysteine-responsive cyano-tetraphenylporphyrin (TPP-CN) and a water-soluble carboxylatopillar[5]arene (CP5). TPP-CN/CP5 not only possesses excellent photodynamic antibacterial properties, but also shows good anti-inflammatory and cell protection capabilities. Under 660 nm light irradiation, TPP-CN/CP5 could rapidly produce abundant ROS for sterilization. After the PDT process, the addition of cysteine (Cys) triggers the release of H2 S from TPP-CN. H2 S then stops the induced inflammation by inhibiting the production of related inflammatory factors. Both in vitro and in vivo experiments show the excellent antibacterial effects and anti-inflammatory abilities of TPP-CN/CP5. These results will certainly promote the clinical application of PDT in the treatment of bacterial infectious diseases.

Photothermal-Enhanced Dual Inhibition of Lactate/Kynurenine Metabolism for Promoting Tumor Immunotherapy

Traditionally referred to as "metabolic junk", lactate has now been recognized as essential "energy currency" and crucial "messenger" that contributes to tumor evolution, immunosuppression, etc., thus presenting a promising strategy for antitumor interventions. Similarly, kynurenine (Kyn) also exerts an immunosuppressive function, thereby significantly compromising the effectiveness of immunotherapy. This study proposes and validates a strategy for enhancing immunotherapy through photothermal-assisted depletion of lactate sustained by cycle-like O2 supply, with blocking the tryptophan (Trp)/Kyn metabolic pathway. In brief, a nanozyme therapeutic agent (PNDPL) is constructed, which mainly consists of PtBi nanozymes, lactate oxidase (LOX) and the indoleamine 2,3-dioxygenase (IDO) inhibitor NLG919. The PtBi nanozymes, which exhibit a catalase (CAT)-like activity, form a positive feedback loop with LOX to consume lactate while self-supplying O2 . Moreover, PtBi nanozymes retain enzyme-like performance even in a slightly acidic tumor microenvironment. Under 1064 nm irradiation, photothermal therapy (PTT) not only induces tumor cell death but also accelerates lactate exhaustion. Therefore, the combination of lactate depletion-induced starvation therapy and PTT, along with the blocking of IDO-mediated immune escape, effectively inhibits tumor growth and reverses immunosuppressive microenvironment, thus preventing tumor metastasis. This study represents the first investigation into the synergistic antitumor effects by lactate metabolism regulation and IDO-related immunotherapy.

Recent advances in nanomedicine for metabolism-targeted cancer therapy

Metabolism denotes the sum of biochemical reactions that maintain cellular function. Different from most normal differentiated cells, cancer cells adopt altered metabolic pathways to support malignant properties. Typically, almost all cancer cells need a large number of proteins, lipids, nucleotides, and energy in the form of ATP to support rapid division. Therefore, targeting tumour metabolism has been suggested as a generic and effective therapy strategy. With the rapid development of nanotechnology, nanomedicine promises to have a revolutionary impact on clinical cancer therapy due to many merits such as targeting, improved bioavailability, controllable drug release, and potentially personalized treatment compared to conventional drugs. This review comprehensively elucidates recent advances of nanomedicine in targeting important metabolites such as glucose, glutamine, lactate, cholesterol, and nucleotide for effective cancer therapy. Furthermore, the challenges and future development in this area are also discussed.

Organic nanomotors: emerging versatile nanobots

Artificial nanomotors are self-propelled nanometer-scaled machines that are capable of converting external energy into mechanical motion. A significant progress on artificial nanomotors over the last decades has unlocked the potential of carrying out manipulatable transport and cargo delivery missions with enhanced efficiencies owing to their stimulus-responsive autonomous movement in various complex environments, allowing for future advances in a large range of applications. Emergent kinetic systems with programmable energy-converting mechanisms that are capable of powering the nanomotors are attracting increasing attention. This review highlights the most-recent representative examples of synthetic organic nanomotors having self-propelled motion exclusively powered by organic molecule- or their aggregate-based kinetic systems. The stimulus-responsive propulsion mechanism, motion behaviors, and performance in antitumor therapy of organic nanomotors developed so far are illustrated. A future perspective on the development of organic nanomotors is also proposed. With continuous innovation, it is believed that the scope and possible achievements in practical applications of organic nanomotors with diversified organic kinetic systems will expand.

Polyoxometalate-Nanozyme-Integrated Nanomotors (POMotors) for Self-Propulsion-Promoted Synergistic Photothermal-Catalytic Tumor Therapy

Enzyme-powered nanomotors have demonstrated promising potential in biomedical applications, especially for catalytic tumor therapy, owing to their ability of self-propulsion and bio-catalysis. However, the fragility of natural enzymes limits their environmental adaptability and also therapeutic efficacy in catalysis-enabled tumor therapy. Herein, polyoxometalate-nanozyme-based light-driven nanomotors were designed and synthesized for targeted synergistic photothermal-catalytic tumor therapy. In this construct, the peroxidase-like activity of the P2 W18 Fe4 polyoxometalates-based nanomotors can provide self-propulsion and facilitate their production of reactive oxygen species thus killing tumor cells, even in the weakly acidic tumor microenvironment. Conjugated polydopamine endows the nanomotors with the capability of light-driven self-propulsion behavior. After 10 min of NIR (808 nm) irradiation, along with the help of epidermal growth factor receptor antibody, the targeted accumulation and penetration of nanomotors in the tumor enabled highly efficient synergistic photothermal-catalytic therapy. This approach overcomes the disadvantages of the intrinsically fragile nature of enzyme-powered nanomotors in physiological environments and, more importantly, provides a motility-behavior promoted synergistic anti-tumor strategy.

Dual-Fuel Propelled Nanomotors with Two-Stage Permeation for Deep Bacterial Infection in the Treatment of Pulpitis

Bacterial infection-induced inflammatory response could cause irreversible death of pulp tissue in the absence of timely and effective therapy. Given that, the narrow structure of root canal limits the therapeutic effects of passive diffusion-drugs, considerable attention has been drawn to the development of nanomotors, which have high tissue penetration abilities but generally face the problem of insufficient fuel concentration. To address this drawback, dual-fuel propelled nanomotors (DPNMs) by encapsulating L-arginine (L-Arg), calcium peroxide (CaO2 ) in metal-organic framework is developed. Under pathological environment, L-Arg could release nitric oxide (NO) by reacting with reactive oxygen species (ROS) to provide the driving force for movement. Remarkably, the depleted ROS could be supplemented through the reaction between CaO2 with acids abundant in the inflammatory microenvironment. Owing to high diffusivity, NO achieves further tissue penetration based on the first-stage propulsion of nanomotors, thereby removing deep-seated bacterial infection. Results indicate that the nanomotors effectively eliminate bacterial infection based on antibacterial activity of NO, thereby blocking inflammatory response and oxidative damage, forming reparative dentine layer to avoid further exposure and infection. Thus, this work provides a propagable strategy to overcome fuel shortage and facilitates the therapy of deep lesions.

Chemotactic Micro/Nanomotors for Biomedical Applications

In nature, many organisms respond chemotactically to external chemical stimuli in order to extract nutrients or avoid danger. Inspired by this natural chemotaxis, micro/nanomotors with chemotactic properties have been developed and applied to study a variety of disease models. This chemotactic strategy has shown promising results and has attracted the attention of an increasing number of researchers. This paper mainly reviews the construction methods of different types of chemotactic micro/nanomotors, the mechanism of chemotaxis, and the potential applications in biomedicine. First, based on the classification of materials, the construction methods and therapeutic effects of chemotactic micro/nanomotors based on natural cells and synthetic materials in cellular and animal experiments will be elaborated in detail. Second, the mechanism of chemotaxis of micro/nanomotors is elaborated in detail: chemical reaction induced chemotaxis and physical process driven chemotaxis. In particular, the main differences and significant advantages between chemotactic micro/nanomotors and magnetic, electrical and optical micro/nanomotors are described. The applications of chemotactic micro/nanomotors in the biomedical fields in recent years are then summarized, focusing on the mechanism of action and therapeutic effects in cancer and cardiovascular disease. Finally, the authors are looking forward to the future development of chemotactic micro/nanomotors in the biomedical fields.

H2O2-stimulated Janus-shaped self-propelled nanomotors as an active treatment for acute renal injury

As emerging nanosystems, nanomotors have been applied in the active treatment of many diseases. In this paper, Pt@chitosan-loaded melatonin asymmetrical nanomaterials embedded with L-serine (S, kidney injury molecule 1-targeting agent) were constructed to alleviate acute kidney injury (AKI). The Janus nanocarriers arrived at the renal injury site via the bloodstream and exhibited high permeability. Because of melatonin distribution in the kidneys combined with H2O2-stimulated O2 release, the administration of the Janus nanosystem resulted in active treatment through the motion of nanomotors by asymmetrical O2 release.

Liposome-coated nanoparticle triggers prostate cancer ferroptosis through synergetic chemodynamic-gas therapy

Ferroptosis has attracted much attention for tumor treatment. It has been recently identified that castration-resistant prostate cancer (CRPC) is vulnerable to ferroptosis inducers. Notably, chemodynamic therapy (CDT), triggered by metal ions, could easily induce ferroptosis via a Fenton/Fenton-like reaction, but its efficiency was highly dependent on the intracellular H2O2 concentration, posing significant changes for its clinical translation. Herein, we attached glucose oxidase (GOx) onto the surface of manganese sulfide (MnS) and developed therapeutic nanocomposites (Lpo@MnS-GOx) after encapsulating with liposome. Upon internalization by cancer cells, the released GOx could transform glucose into gluconic acid (GA) and H2O2. Notably, the generated GA stimulates the degradation of MnS, followed by the promotion of the release of H2S and Mn2+, whereas the produced H2O2 can amplify the Fenton-like response initiated by Mn2+. The enhanced CDT combined with the gas therapy effect could simultaneously promote the accumulation of reactive oxygen species and finally induce ferroptosis and exhibit an excellent anti-tumor effect. Consequently, these Lpo@MnS-GOx NPs with enhanced ferroptosis-induced effect will find great potential for CRPC cancer treatment.

Current Advances on Nanomaterials Interfering with Lactate Metabolism for Tumor Therapy

Increasing numbers of studies have shown that tumor cells prefer fermentative glycolysis over oxidative phosphorylation to provide a vast amount of energy for fast proliferation even under oxygen-sufficient conditions. This metabolic alteration not only favors tumor cell progression and metastasis but also increases lactate accumulation in solid tumors. In addition to serving as a byproduct of glycolytic tumor cells, lactate also plays a central role in the construction of acidic and immunosuppressive tumor microenvironment, resulting in therapeutic tolerance. Recently, targeted drug delivery and inherent therapeutic properties of nanomaterials have attracted great attention, and research on modulating lactate metabolism based on nanomaterials to enhance antitumor therapy has exploded. In this review, the advanced tumor therapy strategies based on nanomaterials that interfere with lactate metabolism are discussed, including inhibiting lactate anabolism, promoting lactate catabolism, and disrupting the "lactate shuttle". Furthermore, recent advances in combining lactate metabolism modulation with other therapies, including chemotherapy, immunotherapy, photothermal therapy, and reactive oxygen species-related therapies, etc., which have achieved cooperatively enhanced therapeutic outcomes, are summarized. Finally, foreseeable challenges and prospective developments are also reviewed for the future development of this field.

Extracellular vesicles and their engineering strategies, delivery systems, and biomedical applications

Extracellular vesicles are nanoscale vesicles that can be secreted by all cell types, are intracellular in origin and have the same composition as their parent cells, play a key role in intercellular communication in organismal health and disease, and are now often used as biomarkers of disease and therapeutic agents in biomedical research. When injected locally or systemically, they have the ability to provide a variety of therapeutic effects, for example, regeneration of skin damage or restoration of cardiac function. However, direct injection of extracellular vesicles may result in their rapid clearance from the injection site.In order to maintain the biological activity of extracellular vesicles and to control the release of effective concentrations for better therapeutic efficacy during long-term disease treatment, the design of an optimized drug delivery system is necessary and different systems for the continuous delivery of extracellular vesicles have been developed. This paper first provides an overview of the biogenesis, composition and physiological function of extracellular vesicles, followed by a review of different strategies for extracellular vesicle isolation and methods for engineering extracellular vesicles. In addition, this paper reviews the latest extracellular vesicle delivery platforms such as micro-nanoparticles, injectable hydrogels, microneedles and scaffold patches. At the same time, the research progress and key cases of extracellular vesicle delivery systems in the field of biomedical therapeutics are described. Finally, the challenges and future trends of extracellular vesicle delivery are discussed.

Progress in the Treatment of Peritoneal Metastatic Cancer and the Application of Therapeutic Nanoagents

Peritoneal metastatic cancer is a cancer caused by the direct growth of cancer cells from the primary site through the bloodstream, lymph, or peritoneum, which is a difficult part of current clinical treatment. In the abdominal cavity of patients with metastatic peritoneal cancer, there are usually nodules of various sizes and malignant ascites. Among them, nodules of different sizes can obstruct intestinal movement and form intestinal obstruction, while malignant ascites can cause abdominal distension and discomfort, and even cause patients to have difficulty in breathing. The pathology and physiology of peritoneal metastatic cancer are complex and not fully understood. The main hypothesis is "seed" and "soil"; i.e., cells from the primary tumor are shed and implanted in the peritoneal cavity (peritoneal metastasis). In the last two decades, the main treatment modalities used clinically are cytoreductive surgery (CRS), systemic chemotherapy, intraperitoneal chemotherapy, and combined treatment, all of which help to improve patient survival and quality of life (QOL). However, the small-molecule chemotherapeutic drugs used clinically still have problems such as rapid drug metabolism and systemic toxicity. With the rapid development of nanotechnology in recent years, therapeutic nanoagents for the treatment of peritoneal metastatic cancer have been gradually developed, which has improved the therapeutic effect and reduced the systemic toxicity of small-molecule chemotherapeutic drugs to a certain extent. In addition, nanomaterials have been developed not only as therapeutic agents but also as imaging agents to guide peritoneal tumor CRS. In this review, we describe the etiology and pathological features of peritoneal metastatic cancer, discuss in detail the clinical treatments that have been used for peritoneal metastatic cancer, and analyze the advantages and disadvantages of the different clinical treatments and the QOL of the treated patients, followed by a discussion focusing on the progress, obstacles, and challenges in the use of therapeutic nanoagents in peritoneal metastatic cancer. Finally, therapeutic nanoagents and therapeutic tools that may be used in the future for the treatment of peritoneal metastatic cancer are prospected.

Advances in Cancer Vaccine Research

The use of cancer vaccines is considered a promising therapeutic strategy in clinical oncology, which is achieved by stimulating antitumor immunity with tumor antigens delivered in the form of cells, peptides, viruses, and nucleic acids. The ideal cancer vaccine has many advantages, including low toxicity, specificity, and induction of persistent immune memory to overcome tumor heterogeneity and reverse the immunosuppressive microenvironment. Many therapeutic vaccines have entered clinical trials for a variety of cancers, including melanoma, breast cancer, lung cancer, and others. However, many challenges, including single antigen targeting, weak immunogenicity, off-target effects, and impaired immune response, have hindered their broad clinical translation. In this review, we introduce the principle of action, components (including antigens and adjuvants), and classification (according to applicable objects and preparation methods) of cancer vaccines, summarize the delivery methods of cancer vaccines, and review the clinical and theoretical research progress of cancer vaccines. We also present new insights into cancer vaccine technologies, platforms, and applications as well as an understanding of potential next-generation preventive and therapeutic vaccine technologies, providing a broader perspective for future vaccine design.

Ultrasmall Self-Cascade AuNP@FeS Nanozyme for H2S-Amplified Ferroptosis Therapy

Recently, nanozymes with peroxidase (POD)-like activity have shown great promise for ferroptosis-based tumor therapy, which are capable of transforming hydrogen peroxide (H2O2) to highly toxic hydroxyl radicals (•OH). However, the unsatisfactory therapeutic performance of nanozymes due to insufficient endogenous H2O2 and acidity at tumor sites has always been a conundrum. Herein, an ultrasmall gold (Au) @ ferrous sulfide (FeS) cascade nanozyme (AuNP@FeS) with H2S-releasing ability constructed with an Au nanoparticle (AuNP) and an FeS nanoparticle (FeSNP) is designed to increase the H2O2 level and acidity in tumor cells via the collaboration between cascade reactions of AuNP@FeS and the biological effects of released H2S, achieving enhanced •OH generation as well as effective ferroptosis for tumor therapy. The cascade reaction in tumor cells is activated by the glucose oxidase (GOD)-like activity of AuNP in AuNP@FeS to catalyze intratumoral glucose into H2O2 and gluconic acid; meanwhile, the released H2S from AuNP@FeS reduces H2O2 consumption by inhibiting intracellular catalase (CAT) activity and promotes lactic acid accumulation. The two pathways synergistically boost H2O2 and acidity in tumor cells, thus inducing a cascade to generate abundant •OH by catalyzing H2O2 through the POD-like activity of FeS in AuNP@FeS and ultimately causing amplified ferroptosis. In vitro and in vivo experiments demonstrated that AuNP@FeS presents a superior tumor therapeutic effect compared to that of AuNP or FeS alone. This strategy represents a simple but powerful method to amplify ferroptosis with H2S-releasing cascade nanozymes and will pave a new way for the development of tumor therapy.

Positive Chemotaxis of CREKA-Modified Ceria@Polydopamine Biomimetic Nanoswimmers for Enhanced Penetration and Chemo-photothermal Tumor Therapy

Tumor interstitial pressure represents the greatest barrier against drug diffusion into the depth of the tumor. Biometric nanomotors highlight the possibility of enhanced deep penetration and improve cellular uptake. However, control of their directionality remains difficult to achieve. Herein, we report cysteine-arginine-glutamic acid-lysine-alanine (CREKA)-modified ceria@polydopamine nanobowls as tumor microenvironment-fueled nanoscale motors for positive chemotaxis into the tumor depth or toward tumor cells. Upon laser irradiation, this nanoswimmer rapidly depletes the tumor microenvironment-specific hydrogen peroxide (H2O2) in the nanobowl, contributing to a self-generated gradient and subsequently propulsion (9.5 μm/s at 46 °C). Moreover, the asymmetrical modification of CREKA on nanobowls could automatically reconfigure the motion direction toward tumor depth or tumor cells in response to receptor-ligand interaction, leading to a deep penetration (70 μm in multicellular spheroids) and enhanced antitumor effects over conventional nanomedicine-induced chemo-photothermal therapy (tumor growth inhibition rate: 84.2% versus 56.9%). Thus, controlling the direction of nanomotors holds considerable potential for improved antitumor responses, especially in solid tumors with high tumor interstitial pressure.

Biodegradable CuMoO4 Nanodots with Multienzyme Activities for Multimodal Treatment of Tumor

Due to their complexity and variability, tumors need to be treated with multimodal combined therapy, which requires the development of therapeutic agents that can provide multimodal therapeutic effects. Herein, CuMoO4 nanodots smaller than 10 nm that can be prepared by simple hydrothermal method are reported. These nanodots can be well dispersed in water and have good biosafety and biodegradability. Further studies show that these nanodots also present multienzyme activities, such as catalase, peroxidase and glutathione peroxidase. In addition, CuMoO4 nanodots exhibit high photothermal conversion efficiency (41%) under 1064 nm near-infrared laser irradiation. In vitro and in vivo experimental results indicate that CuMoO4 nanodots can effectively inhibit the instinctive regulation of tumor cells to oxidative stress, provide sustained treatment to achieve photothermal synergistic ferroptosis, and trigger immune responses to immunogenic cell death. It is worth mentioning that the CuMoO4 nanodots also cause cuproptosis of tumor cells. This study provides a promising nanoplatform for multimodal combined therapy of cancer.

Sulfate-reducing bacteria loaded in hydrogel as a long-lasting H2S factory for tumor therapy

The continuous supply of hydrogen sulfide (H2S) gas at high concentrations to tumors is considered a promising and safe strategy for tumor therapy. However, the absence of a durable and cost-effective H2S-producing donor hampers its extensive application. Sulfate-reducing bacteria (SRB) can serve as an excellent H2S factory due to their ability to metabolize sulfate into H2S. Herein, a novel injectable chondroitin sulfate (ChS) hydrogel loaded with SRB (SRB@ChS Gel) is proposed to sustainably produce H2S in tumor tissues to overcome the limitations of current H2S gas therapy. In vitro, the ChS Gel not only supports the growth of encapsulated SRB, but also supplies a sulfate source to the SRB to produce high concentrations of H2S for at least 7 days, resulting in mitochondrial damage and immunogenic cell death. Once injected into tumor tissue, the SRB@ChS Gel can constantly produce H2S for >5 days, significantly inhibiting tumor growth. Furthermore, such treatment activates systemic anti-tumor immune responses, suppresses the growth of distant and recurrent tumors, as well as lung metastases, meanwhile with negligible side effects. Therefore, the injectable SRB@ChS Gel, as a safe and long-term, self-sustained H2S-generating factory, provides a promising strategy for anti-tumor therapy.

Self-Propelled Enzymatic Nanomotors from Prodrug-Skeletal Zeolitic Imidazolate Frameworks for Boosting Multimodel Cancer Therapy Efficiency

Self-propelled nanomotors, which can autonomous propelled by harnessing others type of energy, have shown tremendous potential as drug delivery systems for cancer therapy. However, it remains challenging for nanomotors in tumor theranostics because of their structural complexity and deficient therapeutic model. Herein, glucose-fueled enzymatic nanomotors (GC6@cPt ZIFs) are developed through encapsulation of glucose oxidase (GOx), catalase (CAT), and chlorin e6 (Ce6) using cisplatin-skeletal zeolitic imidazolate frameworks (cPt ZIFs) for synergetic photochemotherapy. The GC6@cPt ZIFs nanomotors can produce O₂ through enzymatic cascade reactions for propelling the self-propulsion. Trans-well chamber and multicellular tumor spheroids experiments demonstrate the deep penetration and high accumulation of GC6@cPt nanomotors. Importantly, the glucose-fueled nanomotor can release the chemotherapeutic cPt and generate reactive oxygen species under laser irradiation, and simultaneously consume intratumoral over-expressed glutathione. Mechanistically, such processes can inhibit cancer cell energy and destroy intratumoral redox balance to synergistically damage DNA and induce tumor cell apoptosis. Collectively, this work demonstrates that the self-propelled prodrug-skeleton nanomotors with oxidative stress activation can highlight a robust therapeutic capability of oxidants amplification and glutathione depletion to boost the synergetic cancer therapy efficiency.

Chemical tunability of advanced materials used in the fabrication of micro/nanobots

Micro and nanobots (MNBs) are unprecedented in their ability to be chemically tuned for autonomous tasks with enhanced targeting and functionality while maintaining their mobility. A myriad of chemical modifications involving a large variety of advanced materials have been demonstrated to be effective in the design of MNBs. Furthermore, they can be controlled for their autonomous motion, and their ability to carry chemical or biological payloads. In addition, MNBs can be modified to achieve targetability with specificity for biological implications. MNBs by virtue of their chemical compositions may be limited by their biocompatibility, tissue accumulation, poor biodegradability and toxicity. This review presents a note on artificial intelligence materials (AIMs), their importance, and the dimensional scales at which intrinsic autonomy can be achieved for diverse utility. We briefly discuss the evolution of such systems with a focus on their advancements in nanomedicine. We highlight MNBs covering their contemporary traits and the emergence of a few start-ups in specific areas. Furthermore, we showcase various examples, demonstrating that chemical tunability is an attractive primary approach for designing MNBs with immense capabilities both in biology and chemistry. Finally, we cover biosafety and ethical considerations in designing MNBs in the era of artificial intelligence for varied applications.

Copper Single-Atom Jellyfish-like Nanomotors for Enhanced Tumor Penetration and Nanocatalytic Therapy

Single-atom catalysts with extraordinary catalytic activity have been receiving great attention in tumor therapy. However, most single-atom catalysts lack self-propulsion properties, restricting them from actively approaching cancer cells or penetrating the interior of tumors. Herein, we design N-doped jellyfish-like mesoporous carbon nanomotors coordinated with single-atom copper (Cu-JMCNs). It is a combination of single-atom nanocatalytic medicine and nanomotor self-propulsion for cancer therapy. The Cu single atom can catalyze H₂O₂ into toxic hydroxyl radical (^•OH) for chemodynamic therapy (CDT). Near-infrared light triggers Cu-JMCNs to achieve self-thermophoretic motion because of the jellyfish-like asymmetric structure and photothermal property of carbon, which significantly improves the cellular uptake and the penetration of three-dimensional tumors. In vivo experiments indicate that the combination of single-atom Cu for CDT and near-infrared light propulsion can achieve over 85% tumor inhibition rate. This work sheds light on the development of advanced nanomotors with single-atom catalysts for biomedical applications.

pH/ROS-responsive propelled nanomotors for the active treatment of renal injury

Effective drugs that can be quickly delivered to and retained for a long time in the renal tubule are necessary for acute kidney injury (AKI) treatment. In this study, a gold nanoparticle-modified mesoporous silica (Au@MSN-NH₂)-camouflaged (methoxyphenyl)(morpholino)phosphinodithioic acid (GYY4137) asymmetrical nanosystem decorated with L-serine (S; an AKI-targeting agent) and D-Arg-dimethylTyr-Lys-Phe-NH₂ (TK-SS31; a reactive oxygen species (ROS)-sensitive thioketal linker/mitochondria-targeted antioxidant) was constructed for the treatment of renal tubule and mitochondrial injury as well as the synergistic and active treatment of AKI. Due to the enhanced permeability and retention (EPR) of nanomotors, they could progressively accumulate in renal sites. The asymmetrical nanosystem achieved effective drug distribution in the kidney as well as pH-responsive hydrogen sulfide (H₂S) release and ROS-responsive SS31 release, resulting in an active therapeutic effect mediated by nanomotor motion resulting from asymmetrical H₂S release.

Highly Penetrable Drug-Loaded Nanomotors for Photothermal-Enhanced Ferroptosis Treatment of Tumor

A kind of drug-loaded nanomotors with deep penetration was developed to improve the therapeutic effect of ferroptosis on tumor. The nanomotors were constructed by co-loading hemin and ferrocene (Fc) on the surface of bowl-shaped polydopamine (PDA) nanoparticles. The near-infrared response of PDA makes the nanomotor have high tumor penetration capability. In vitro experiments show that the nanomotors can exhibit good biocompatibility, high light to heat conversion efficiency, and deep tumor permeability. It is worth noting that under the catalysis of H2O2 overexpressed in the tumor microenvironment, the Fenton-like reagents hemin and Fc loaded on the nanomotors can increase the concentration of toxic •OH. Furthermore, hemin can consume glutathione in tumor cells and trigger the up-regulation of heme oxygenase-1, which can efficiently decompose hemin to Fe2+, thus producing the Fenton reaction and causing a ferroptosis effect. Notably, thanks to the photothermal effect of PDA, it can enhance the generation of reactive oxygen species and thus intervene in the Fenton reaction process, thereby enhancing the ferroptosis effect photothermally. In vivo antitumor results show that the drug-loaded nanomotors with high penetrability showed an effective antitumor therapeutic effect.

An enzyme-instructed self-assembly system induces tumor acidosis via sequential-dual effect for cancer selective therapy

The acidosis anti-tumor therapy, based on the altered energy metabolism pathway of tumor cells, has been proposed as an attractive method for cancer selective treatment. However, the strategy of inducing tumor acidosis by using a single drug to simultaneously inhibit both lactate efflux and consumption has not been reported yet. Herein, an in situ enzyme-instructed self-assembly (EISA) system was rationally fabricated to induce tumor acidosis apoptosis for cancer selective therapy. Depending on the sequential effect of the in situ EISA system, the targeted drug was successively distributed on the membrane and intracellular, inhibiting MCT4 mediated lactate efflux and mitochondrial tricarboxylic acid (TCA) cycle mediated lactate consumption, respectively. Through the dual obstruction of lactate metabolism to trigger tumor acidosis, the in situ EISA nanomedicine showed selective growth and migration inhibition against cancer cells. In addition, the nanomedicine also displayed a radio-sensitization effect in vitro due to causing the mitochondrial dysfunction, and exhibited a prominent synergistic chemo-radiotherapy anti-tumor performance in vivo. Accordingly, this work demonstrated that the in situ EISA system could endow the LND with sequential-dual effects to induce tumor acidosis, which may provide an enlightening strategy for anticancer drug delivery and cancer selective therapy. STATEMENT OF SIGNIFICANCE: With the help of the sequential effect of in situ EISA, the serial attack of LND against different targets was effectively realized to induce tumor acidosis and combined chemo-radiotherapy, implying the importance of the relationship between structure and function, which could offer a distinctive inspiration for future drug delivery system design and anti-tumor application.

Polydopamine nanomotors loaded indocyanine green and ferric ion for photothermal and photodynamic synergistic therapy of tumor

The limited penetration depth of nanodrugs in the tumor and the severe hypoxia inside the tumor significantly reduce the efficacy of photothermal-photodynamic synergistic therapy (PTT-PDT). Here, we synthesized a methoxypolyethylene glycol amine (mPEG-NH₂)-modified walnut-shaped polydopamine nanomotor (PDA-PEG) driven by near-infrared light (NIR). At the same time, it also loaded the photosensitizer indocyanine green (ICG) via electrostatic/hydrophobicinteractions and chelated with ferric ion (Fe³⁺). Under the irradiation of NIR, the asymmetry of PDA-PEG morphology led to the asymmetry of local photothermal effects and the formation of thermal gradient, which can make the nanomotor move autonomously. This ability of autonomous movement was proved to be used to improve the permeability of the nanomotor in three-dimensional (3D) tumor sphere. Fe³⁺ can catalyze endogenous hydrogen peroxide to produce oxygen, so as to overcome the hypoxia of tumor microenvironment and thereby generate more singlet oxygen to kill tumor cells. Animal experiments in vivo confirmed that the nanomotors had a good PTT-PDT synergistic treatment effect. The introduction of nanomotor technology has brought new ideas for cancer optical therapy.

A nitric-oxide driven chemotactic nanomotor for enhanced immunotherapy of glioblastoma

The major challenges of immunotherapy for glioblastoma are that drugs cannot target tumor sites accurately and properly activate complex immune responses. Herein, we design and prepare a kind of chemotactic nanomotor loaded with brain endothelial cell targeting agent angiopep-2 and anti-tumor drug (Lonidamine modified with mitochondrial targeting agent triphenylphosphine, TLND). Reactive oxygen species and inducible nitric oxide synthase (ROS/iNOS), which are specifically highly expressed in glioblastoma microenvironment, are used as chemoattractants to induce the chemotactic behavior of the nanomotors. We propose a precise targeting strategy of brain endothelial cells-tumor cells-mitochondria. Results verified that the released NO and TLND can regulate the immune circulation through multiple steps to enhance the effect of immunotherapy, including triggering the immunogenic cell death of tumor, inducing dendritic cells to mature, promoting cytotoxic T cells infiltration, and regulating tumor microenvironment. Moreover, this treatment strategy can form an effective immune memory effect to prevent tumor metastasis and recurrence.

Engineering lactate-modulating nanomedicines for cancer therapy

Lactate in tumors has long been considered "metabolic junk" derived from the glycolysis of cancer cells and utilized only as a biomarker of malignancy, but is presently believed to be a pivotal regulator of tumor development, maintenance and metastasis. Indeed, tumor lactate can be a "fuel" for energy supply and functions as a signaling molecule, which actively contributes to tumor progression, angiogenesis, immunosuppression, therapeutic resistance, etc., thus providing promising opportunities for cancer treatment. However, the current approaches for regulating lactate homeostasis with available agents are still challenging, which is mainly due to the short half-life, low bioavailability and poor specificity of these agents and their unsatisfactory therapeutic outcomes. In recent years, lactate modulation nanomedicines have emerged as a charming and efficient strategy for fighting cancer, which play important roles in optimizing the delivery of lactate-modulating agents for more precise and effective modulation and treatment. Integrating specific lactate-modulating functions in diverse therapeutic nanomedicines may overcome the intrinsic restrictions of different therapeutic modalities by remodeling the pathological microenvironment for achieving enhanced cancer therapy. In this review, the most recent advances in the engineering of functional nanomedicines that can modulate tumor lactate for cancer therapy are summarized and discussed, and the fundamental mechanisms by which lactate modulation benefits various therapeutics are elucidated. Finally, the challenges and perspectives of this emerging strategy in the anti-tumor field are highlighted.

Medical micro- and nanomotors in the body

Attributed to the miniaturized body size and active mobility, micro- and nanomotors (MNMs) have demonstrated tremendous potential for medical applications. However, from bench to bedside, massive efforts are needed to address critical issues, such as cost-effective fabrication, on-demand integration of multiple functions, biocompatibility, biodegradability, controlled propulsion and in vivo navigation. Herein, we summarize the advances of biomedical MNMs reported in the past two decades, with particular emphasis on the design, fabrication, propulsion, navigation, and the abilities of biological barriers penetration, biosensing, diagnosis, minimally invasive surgery and targeted cargo delivery. Future perspectives and challenges are discussed as well. This review can lay the foundation for the future direction of medical MNMs, pushing one step forward on the road to achieving practical theranostics using MNMs.

NIR-II Light Powered Asymmetric Hydrogel Nanomotors for Enhanced Immunochemotherapy

Nanomotors are appealing drug carriers, and the strength of the propelling force is important for their motion capability. Though high motion efficiency has been achieved with 808 nm light driven Janus-structured noble metal nanomotors, the NIR-I light penetration depth and material biocompatibility limit their broad application. Herein, we develop a 1064 nm NIR-II light driven asymmetric hydrogel nanomotor (AHNM) with high motion capability and load it with doxorubicin for enhanced immunochemotherapy. Magnetic field assisted photopolymerization generates an asymmetric distribution of Fe₃ O₄ @Cu₉ S₈ nanoparticles in the AHNM, producing self-thermophoresis as driving force under NIR-II irradiation. The AHNM is also functionalized with dopamine for the capture and retention of tumor-associated antigens to boost immune activation. The as-obtained NIR-II light driven AHNM has a high tumor tissue penetration capability and enhances immunochemotherapy, providing a promising strategy for cancer therapy.

Intelligent polymeric hydrogen sulfide delivery systems for therapeutic applications

Hydrogen sulfide (H₂S) plays an important role in regulating various pathological processes such as protecting mammalian cell from harmful injuries, promoting tissue regeneration, and regulating the process of various diseases caused by physiological disorders. Studies have revealed that the physiological effects of H₂S are highly associated with its concentrations. At relatively low concentration, H₂S shows beneficial functions. However, long-time and high-dose donation of H₂S would inhibit regular biological process, resulting in cell dysfunction and apoptosis. To regulate the dosage of H₂S delivery for precision medicine, H₂S delivery systems with intelligent characteristics were developed and a variety of biocompatibility polymers have been utilized to establish intelligent polymeric H₂S delivery systems, with the abilities to specifically target the lesions, smartly respond to pathological microenvironments, as well as real-timely monitor H₂S delivery and lesion conditions by incorporating imaging-capable moieties. In this review, we focus on the design, preparation, and therapeutic applications of intelligent polymeric H₂S delivery systems in cardiovascular therapy, inflammatory therapy, tissue regenerative therapy, cancer therapy and bacteria-associated therapy. Strategies for precise H₂S therapies especially imaging-guided H₂S theranostics are highlighted. Since H₂S donors with stimuli-responsive characters are vital components for establishing intelligent H₂S delivery systems, the development of H₂S donors is also briefly introduced.

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H₂S is an endogenous gasotransmitter that plays important role in regulating various physiological and pathological pathways.

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Controlled H₂S delivery is vital since the therapeutic effects of H₂S are highly associated with its concentrations.

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Intelligent polymeric H₂S delivery systems possess specific targeting, stimuli responsive and imaging guided capabilities, representing a strategic option for next generation of therapies.

Recent Advances in One-Dimensional Micro/Nanomotors: Fabrication, Propulsion and Application

Due to their tiny size, autonomous motion and functionalize modifications, micro/nanomotors have shown great potential for environmental remediation, biomedicine and micro/nano-engineering. One-dimensional (1D) micro/nanomotors combine the characteristics of anisotropy and large aspect ratio of 1D materials with the advantages of functionalization and autonomous motion of micro/nanomotors for revolutionary applications. In this review, we discuss current research progress on 1D micro/nanomotors, including the fabrication methods, driving mechanisms, and recent advances in environmental remediation and biomedical applications, as well as discuss current challenges and possible solutions. With continuous attention and innovation, the advancement of 1D micro/nanomotors will pave the way for the continued development of the micro/nanomotor field.

A Universal Chemotactic Targeted Delivery Strategy for Inflammatory Diseases

Above 50% of deaths can be attributed to chronic inflammatory diseases; thus, the construction of drug delivery systems based on effective interaction of inflammatory factors with chemotactic nanoparticles is meaningful. Herein, a zwitterion-based artificial chemotactic nanomotor is proposed for universal precise targeting strategy in vivo, where the high level of reactive oxygen species (ROS) and inducible nitric oxide synthase (iNOS) in inflammatory sites are used as a chemoattractant. Multidimensional static models, dynamic models, and in vivo models are established to evaluate chemotactic performance. The results show that the upregulated ROS and iNOS can induce the chemotaxis of nanomotors to diseased tissues in inflammation-related disease models. Further, mesoscale hydrodynamics simulations are performed to explain the chemotactic behavior of the nanomotors. Such a chemotactic delivery strategy is expected to improve delivery efficiency and may be applicable to a variety of inflammatory diseases.