Intratumoral synthesis of nano-metalchelate for tumor catalytic therapy by ligand field-enhanced coordination

Nano-photosensitizers with gallic acid-involved Fe-O-Cu "electronic storage station" bridging ligand-to-metal charge transfer for efficient catalytic theranostics

NH2-MIL-88B (Fe) (MOF) is a promising photocatalytic material for antitumor therapy because of its distinctive electronic structure. However, inadequate separation of photo-generated electrons and slow reaction rate in low/high-valence iron (Fe) cycles limit their clinical application. In the present study, "electronic storage station" as a ligand-to-metal charge transfer bridge bond was constructed to inhibit recombination of electron/hole under 650 nm laser irradiation. Cupric (Cu) ions and gallic acid (GA) were self-assembled into a MOF (denoted as CGMOF) to create an FeO(GA)Cu bridge bond. GA, characterized by robust electron delocalization and abundant electron-donating groups, significantly enhances electron transfer efficiency for photodynamic therapy (PDT). CGMOF can respond to endogenous glutathione and release cuprous ions, accelerating the iron ion/ferrous ion cycles for chemodynamic therapy (CDT). The released Fe species can serve as T2-weighted magnetic resonance imaging contrast. Extended X-ray absorption fine structure spectra confirmed the presence of GA-containing FeOCu bonds in CGMOF. Furthermore, a series of photo-electrochemical tests confirmed that the formation of FeO(GA)Cu bond prominently elevated the redox capacity and increased the carrier density of CGMOF by 2.74-fold compared to that of MOF. In addition, cinnamaldehyde was grafted onto CGMOF for tumor-responsive hydrogen peroxide self-supply. Concurrently, hyaluronic acid was surface-modified to achieve the targeted delivery of nano-photosensitizers. In summary, this study presents an innovative approach for engineering Fe-based metal-organic frameworks for synergetic PDT/CDT applications.

In situ hydrogel based on Cu-Fe3O4 nanoclusters exploits oxidative stress and the ferroptosis/cuproptosis pathway for chemodynamic therapy

Chemodynamic therapy (CDT) involving the use of metal nanozymes presents new opportunities for the treatment of deep-seated tumors. However, the lower ROS catalytic rate and dependence on high H2O2 concentrations affect therapeutic efficacy. To address this issue, a hydrogel was constructed for the treatment of osteosarcoma by combining Cu-Fe3O4 nanozymes (NCs) and artemisinin (AS) coencapsulated in situ with sodium alginate (ALG) and calcium ions. This hydrogel can release nanoparticles and AS within tumor tissue for an extended period of time, utilizing the multienzyme activity of NCs to achieve ROS accumulation. The carbon radicals (•C) generated from the interaction of Fe2+/Cu2+ with AS amplify oxidative stress, leading to tumor cell damage. Simultaneously, the NCs activate ferroptosis via the GPX4 pathway by depleting GSH and activate cuproptosis via the DLAT pathway by causing intracellular copper overload, enhancing therapeutic efficacy. In vitro experiments confirmed that the NCs-AS-ALG hydrogel has an excellent tumor cell killing effect, while in vivo experimental results demonstrated that it can effectively eliminate tumors with excellent biocompatibility, providing a new approach for osteosarcoma treatment.

Tailored Metal-Based Catalysts: A New Platform for Targeted Anticancer Therapies

Innovative strategies for targeted anticancer therapies have gained significant momentum, with metal complexes emerging as tunable catalysts for more effective and safer treatments. Rational design and engineering of metal complexes enable the development of tailored molecular structures optimized for precision oncology. The strategic incorporation of metal complex catalysts within combinatorial therapies amplifies their anticancer properties. This perspective highlights the advancements in synthetic strategies and rational design since 2019, showing how tailored metal catalysts are optimized by designing structures to release or in situ synthesize active drugs, leveraging the target-specific characteristics to develop more precise cancer therapies. This review explores metal-based catalysts, including those conjugated with biomolecules, nanostructures, and metal-organic frameworks (MOFs), highlighting their catalytic activity in biological environments and their in vitro/in vivo performance. To sum up, the potential of metal complexes as catalysts to reshape the landscape of anticancer therapies and foster novel avenues for therapeutic advancement is emphasized.

A glutathione-activated bismuth-gallic acid metal-organic framework nano-prodrug for enhanced sonodynamic therapy of breast tumor

Sonodynamic therapy is a promising, noninvasive, and precise tumor treatment that leverages sonosensitizers to generate cytotoxic reactive oxygen species during ultrasound stimulation. Gallic acid (GA), a natural polyphenol, possesses certain anti-tumor properties, but exhibits significant toxicity toward normal cells, limiting its application in cancer treatment. To overcome this issue, we synthesized a bismuth-gallic acid (BGA), coordinated metal-organic framework (MOF) nano-prodrug. Upon encountering glutathione (GSH), BGA gradually dissociated and depleted GSH, releasing GA, which had anti-tumor effects. As an MOF with semiconductor properties, BGA primarily produced superoxide anion radical upon ultrasound excitation. After the release of GA, GA generated superoxide anion radical and further produced high toxic singlet oxygen under ultrasound stimulation, while further oxidizing and consuming GSH, enhancing sonocatalytic performance. Additionally, the released GA induced cell cycle arrest, ultimately leading to apoptosis. Our results revealed that BGA, as a GSH-activated, metal-polyphenol MOF nano-prodrug, showed potential for use in breast tumor sonodynamic therapy, providing a novel strategy for precise tumor treatment.

Metal ion interference therapy: metal-based nanomaterial-mediated mechanisms and strategies to boost intracellular "ion overload" for cancer treatment

Metal ion interference therapy (MIIT) has emerged as a promising approach in the field of nanomedicine for combatting cancer. With advancements in nanotechnology and tumor targeting-related strategies, sophisticated nanoplatforms have emerged to facilitate efficient MIIT in xenografted mouse models. However, the diverse range of metal ions and the intricacies of cellular metabolism have presented challenges in fully understanding this therapeutic approach, thereby impeding its progress. Thus, to address these issues, various amplification strategies focusing on ionic homeostasis and cancer cell metabolism have been devised to enhance MIIT efficacy. In this review, the remarkable progress in Fe, Cu, Ca, and Zn ion interference nanomedicines and understanding their intrinsic mechanism is summarized with particular emphasis on the types of amplification strategies employed to strengthen MIIT. The aim is to inspire an in-depth understanding of MIIT and provide guidance and ideas for the construction of more powerful nanoplatforms. Finally, the related challenges and prospects of this emerging treatment are discussed to pave the way for the next generation of cancer treatments and achieve the desired efficacy in patients.

Dual Oxygen-Supply Immunosuppression-Inhibiting Nanomedicine to Avoid the Intratumoral Recruitment of Myeloid-Derived Suppressor Cells

Myeloid-derived suppressor cells (MDSCs) are reported to be responsible for the negative prognosis of colorectal cancer (CRC) patients due to the mediated immunosuppressive tumor microenvironment (TME). The selective and chronic circumvention of tumor-infiltrated MDSCs has potential clinical significance for CRC treatment, which unluckily remains a technical challenge. Because tumor hypoxia makes a significant contribution to the recruitment of MDSCs in tumor sites, a dual oxygen-supplied immunosuppression-inhibiting nanomedicine (DOIN) is demonstrated for overcoming tumor hypoxia, which achieves selective and long-term inhibition of intratumoral recruitment of MDSCs. The DOIN is constructed by the encasement of perfluorooctyl bromide (PFOB) and 4-methylumbelliferone (4-MU) into a TME-responsive amphiphilic polymer. This nanoplatform directly carries oxygen to the tumor region and simultaneously loosens the condensed tumor extracellular matrix for the normalization of tumor vasculature, which selectively remodels the TME toward one adverse to the intratumoral recruitment of MDSCs. Importantly, this nanoplatform offers a long-acting alleviation of the hypoxic TME, chronically avoiding the comeback of tumor-infiltrated MDSCs. Consequently, the immunosuppressive TME is relieved, and T cells are successfully proliferated and activated into cytotoxic T lymphocytes, which boosts a systemic immune response and contributes to lasting inhibition of tumor growth with a prolonged survival span of xenograft.

Carrier-Free Nanodrugs: From Bench to Bedside

Carrier-free nanodrugs with extraordinary active pharmaceutical ingredient (API) loading (even 100%), avoidable carrier-induced toxicity, and simple synthetic procedures are considered as one of the most promising candidates for disease theranostics. Substantial studies and the commercial success of "carrier-free" nanocrystals have demonstrated their strong clinical potential. However, their practical translations remain challenging and are impeded by unpredictable assembly processes, insufficient delivery efficiency, and an unclear in vivo fate. In this Perspective, we systematically outline the contemporary and emerging carrier-free nanodrugs based on diverse APIs, as well as highlight their opportunities and challenges in clinical translation. Looking ahead, further improvements in design and preparation, drug delivery, in vivo efficacy, and safety of carrier-free nanomedicines are essential to facilitate their translation from the bench to bedside.

PAFerroptosis Combined with Metabolic Disturbance of Mito by p52-ZER6 for Enhanced Cancer Immunotherapy induced by Nano-Bacilliform-Enzyme

The confused gene expressions and molecular mechanisms for mitochondrial dysfunction of traditional nanoenzymes is a challenge for tumor therapy. Herein, a nano-bacilliform-enzyme obtains the ability to inhibit p52-ZER6 signal pathway, regulate the genes related to mitochondrial metabolism, and possess the GOx/CAT/POD-like property. NBE acquires catalytic activity from the electronic energy transition. The tannin of NBE as a mitochondrial (Mito)-targeting guide overloads MitoROS, and then metabolic disorder and lipid peroxidation of Mito membrane occurs, thus leading to a novel death pathway called PAFerroptosis (pyroptosis, apoptosis, and Ferroptosis). Simultaneously, in order to refrain from mitophagy, hydroxychloroquine is mixed with NBE to form a combo with strength pyroptosis. As a result, NBE/combo improves the PAFerroptosis obviously by activation of CD8+T cells and inactivation of MDSC cells, up-regulating expression of caspase-3 signal pathway, intercepting DHODH pathway to arrive excellent antitumor effect (93%). Therefore, this study establishes a rational nanoenzyme for mitochondrial dysfunction without mitophagy for effective antitumor therapy.

Nanozyme-Incorporated Microneedles for the Treatment of Chronic Wounds

Acute wounds are converted to chronic wounds due to advanced age and diabetic complications. Nanozymes catalyze ROS production to kill bacteria without causing drug resistance, while microneedles (MNs) can break through the skin barrier to deliver drugs effectively. Nanozymes can be intergrateded into MNs delivery systems to improve painless drug delivery. It can also reduce the effective dose of drug sterilization while increasing delivery efficiency and effectively killing wounded bacteria while preventing drug resistance. This paper describes various types of metal nanozymes from previous studies and compares their mutual enhancement with nanozymes. The pooled results show that the MNs, through material innovation, are able to both penetrate the scab and deliver nanozymes and exert additional anti-inflammatory and bactericidal effects. The catalytic effect of some of the nanozymes can also accelerate the lysis of the MNs or create a cascade reaction against inflammation and infection. However, the issue of increased toxicity associated with skin penetration and clinical translation remains a challenge. This study reviews the latest published results and corresponding challenges associated with the use of MNs combined with nanozymes for the treatment of wounds, providing further information for future research.

A H₂S-Evolving Alternately-Catalytic Enzyme Bio-Heterojunction with Antibacterial and Macrophage-Reprogramming Activity for All-Stage Infectious Wound Regeneration

The disorder of the macrophage phenotype and the hostile by-product of lactate evoked by pathogenic infection in hypoxic deep wound inevitably lead to the stagnant skin regeneration. In this study, hydrogen sulfide (H2S)-evolving alternately catalytic bio-heterojunction enzyme (AC-BioHJzyme) consisting of CuFe2S3 and lactate oxidase (LOD) named as CuFe2S3@LOD is developed. AC-BioHJzyme exhibits circular enzyme-mimetic antibacterial (EMA) activity and macrophage re-rousing capability, which can be activated by near-infrared-II (NIR-II) light. In this system, LOD exhausts lactate derived from bacterial anaerobic respiration and generated hydrogen peroxide (H2O2), which provides an abundant stock for the peroxidase-mimetic activity to convert the produced H2O2 into germicidal •OH. The GPx-mimetic activity endows AC-BioHJzyme with a glutathione consumption property to block the antioxidant systems in bacterial metabolism, while the O2 provided by the CAT-mimetic activity can generate 1O2 under the NIR-II irradiation. Synchronously, the H2S gas liberated from CuFe2S3@LOD under the infectious micromilieu allows the reduction of Fe(III)/Cu(II) to Fe(II)/Cu(І), resulting in sustained circular EMA activity. In vitro and in vivo assays indicate that the CuFe2S3@LOD AC-BioHJzyme significantly facilitates the infectious cutaneous regeneration by killing bacteria, facilitating epithelialization/collagen deposition, promoting angiogenesis, and reprogramming macrophages. This study provides a countermeasure for deep infectious wound healing via circular enzyme-mimetic antibiosis and macrophage re-rousing.

A "Ferroptosis-Amplifier" Hydrogel for Eliminating Refractory Cancer Stem Cells Post-lumpectomy

The unique "Iron Addiction" feature of cancer stem cells (CSCs) with tumorigenicity and plasticity generally contributes to the tumor recurrence and metastasis after a lumpectomy. Herein, a novel "Ferroptosis Amplification" strategy is developed based on integrating gallic acid-modified FeOOH (GFP) and gallocyanine into Pluronic F-127 (F127) and carboxylated chitosan (CC)-based hydrogel for CSCs eradication. This "Ferroptosis Amplifier" hydrogel is thermally sensitive and achieves rapid gelation at the postsurgical wound in a breast tumor model. Specifically, gallocyanine, as the Dickkopf-1 (DKK1) inhibitor, can decrease the expression of SLC7A11 and GPX4 and synergistically induce ferroptosis of CSCs with GFP. Encouragingly, it is found that this combination suppresses the migratory and invasive capability of cancer cells via the downregulation of matrix metalloproteinase 7 (MMP7). The in vivo results further confirm that this "Ferroptosis Amplification" strategy is efficient in preventing tumor relapse and lung metastasis, manifesting an effective and promising postsurgical treatment for breast cancer.

Nanogalvanic Cells Release Highly Reactive Electrons in Tumors to Effectively Eliminate Tumors

External stimuli triggering chemical reactions in cancer cells to generate highly reactive chemical species are very appealing for cancer therapy, in which external irradiation activating sensitizers to transfer energy or electrons to surrounding oxygen or other molecules is critical for generating cytotoxic reactive species. However, poor light penetration into tissue, low activity of sensitizers, and reliance on oxygen supply restrict the generation of cytotoxic chemical species in hypoxic tumors, which lowers the therapeutic efficacy. Here, this work presents galvanic cell nanomaterials that can directly release highly reactive electrons in tumors without external irradiation or photosensitizers. The released reactive electrons directly react with surrounding biomolecules such as proteins and DNA within tumors to destroy them or react with other surrounding (bio)molecules to yield cytotoxic chemical species to eliminate tumors independent of oxygen. Administering these nanogalvanic cells to mice results in almost complete remission of subcutaneous solid tumors and deep metastatic tumors. The results demonstrate that this strategy can further arouse an immune response even in a hypoxic environment. This method offers a promising approach to effectively eliminate tumors, similar to photodynamic therapy, but does not require oxygen or irradiation to activate photosensitizers.

Critical learning from industrial catalysis for nanocatalytic medicine

Systematical and critical learning from industrial catalysis will bring inspiration for emerging nanocatalytic medicine, but the relevant knowledge is quite limited so far. In this review, we briefly summarize representative catalytic reactions and corresponding catalysts in industry, and then distinguish the similarities and differences in catalytic reactions between industrial and medical applications in support of critical learning, deep understanding, and rational designing of appropriate catalysts and catalytic reactions for various medical applications. Finally, we summarize/outlook the present and potential translation from industrial catalysis to nanocatalytic medicine. This review is expected to display a clear picture of nanocatalytic medicine evolution.

Gallic acid-loaded HFZIF-8 for tumor-targeted delivery and thermal-catalytic therapy

"Transition" metal-coordinated plant polyphenols are a type of promising antitumor nanodrugs owing to their high biosafety and catalytic therapy potency; however, the major obstacle restricting their clinical application is their poor tumor accumulation. Herein, Fe-doped ZIF-8 was tailored using tannic acid (TA) into a hollow mesoporous nanocarrier for gallic acid (GA) loading. After hyaluronic acid (HA) modification, the developed nanosystem of HFZIF-8/GA@HA was used for the targeted delivery of Fe ions and GA, thereby intratumorally achieving the synthesis of an Fe-GA coordinated complex. The TA-etching strategy facilitated the development of a cavitary structure and abundant coordination sites of ZIF-8, thus ensuring an ideal loading efficacy of GA (23.4 wt%). When HFZIF-8/GA@HA accumulates in the tumor microenvironment (TME), the framework is broken due to the competitive protonation ability of overexpressed protons in the TME. Interestingly, the intratumoral degradation of HFZIF-8/GA@HA provides the opportunity for the in situ "meeting" of GA and Fe ions, and through the coordination of polyhydroxyls assisted by conjugated electrons on the benzene ring, highly stable Fe-GA nanochelates are formed. Significantly, owing to the electron delocalization effect of GA, intratumorally coordinated Fe-GA could efficiently absorb second near-infrared (NIR-II, 1064 nm) laser irradiation and transfer it into thermal energy with a conversion efficiency of 36.7%. The photothermal performance could speed up the Fenton reaction rate of Fe-GA with endogenous H2O2 for generating more hydroxyl radicals, thus realizing thermally enhanced chemodynamic therapy. Overall, our research findings demonstrate that HFZIF-8/GA@HA has potential as a safe and efficient anticancer nanodrug.

Nanomaterials-Induced Redox Imbalance: Challenged and Opportunities for Nanomaterials in Cancer Therapy

Cancer cells typically display redox imbalance compared with normal cells due to increased metabolic rate, accumulated mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This redox imbalance may regulate gene expression, alter protein stability, and modulate existing cellular programs, resulting in inefficient treatment modalities. Therapeutic strategies targeting intra- or extracellular redox states of cancer cells at varying state of progression may trigger programmed cell death if exceeded a certain threshold, enabling therapeutic selectivity and overcoming cancer resistance to radiotherapy and chemotherapy. Nanotechnology provides new opportunities for modulating redox state in cancer cells due to their excellent designability and high reactivity. Various nanomaterials are widely researched to enhance highly reactive substances (free radicals) production, disrupt the endogenous antioxidant defense systems, or both. Here, the physiological features of redox imbalance in cancer cells are described and the challenges in modulating redox state in cancer cells are illustrated. Then, nanomaterials that regulate redox imbalance are classified and elaborated upon based on their ability to target redox regulations. Finally, the future perspectives in this field are proposed. It is hoped this review provides guidance for the design of nanomaterials-based approaches involving modulating intra- or extracellular redox states for cancer therapy, especially for cancers resistant to radiotherapy or chemotherapy, etc.

NADPH Oxidase-Like Nanozyme for High-Efficiency Tumor Therapy Through Increasing Glutathione Consumption and Blocking Glutathione Regeneration

To counteract the high level of reactive oxygen species (ROS) caused by rapid growth, tumor cells resist oxidative stress by accelerating the production and regeneration of intracellular glutathione (GSH). Numerous studies focus on the consumption of GSH, but the regeneration of GSH will enhance the reduction level of tumor cells to resist oxidative stress. Therefore, inhibiting the regeneration of GSH; while, consuming GSH is of great significance for breaking the redox balance of tumor cells. Herein, a simple termed MnOx-coated Au (AMO) nanoflower, as a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) nanoenzyme, is reported for efficient tumor therapy. Au nanoparticles exhibit the capability to catalyze the oxidation of NADPH, hindering GSH regeneration; while, concurrently functioning as a photothermal agent. During the process of eliminating intracellular GSH, MnOx releases Mn2+ that subsequently engages in Fenton-like reactions, ultimately facilitating the implementation of chemodynamic therapy (CDT). Overall, this NOX enzyme-based nanoplatform enhances ROS generation and disrupts the state of reduction equilibrium, inducing apoptosis and ferroptosis by blocking GSH regeneration and increasing GSH consumption, thereby achieving collaborative treatments involving photothermal therapy (PTT), CDT, and catalytic therapy. This research contributes to NADPH and GSH targeted tumor therapy and showcases the potential of nanozymes.

Mitochondrial-Targeted Metal-Phenolic Nanoparticles to Attenuate Intervertebral Disc Degeneration: Alleviating Oxidative Stress and Mitochondrial Dysfunction

As intervertebral disc degeneration (IVDD) proceeds, the dysfunctional mitochondria disrupt the viability of nucleus pulposus cells, initiating the degradation of the extracellular matrix. To date, there is a lack of effective therapies targeting the mitochondria of nucleus pulposus cells. Here, we synthesized polygallic acid-manganese (PGA-Mn) nanoparticles via self-assembly polymerization of gallic acid in an aqueous medium and introduced a mitochondrial targeting peptide (TP04) onto the nanoparticles using a Schiff base linkage, resulting in PGA-Mn-TP04 nanoparticles. With a size smaller than 50 nm, PGA-Mn-TP04 possesses pH-buffering capacity, avoiding lysosomal confinement and selectively accumulating within mitochondria through electrostatic interactions. The rapid electron exchange between manganese ions and gallic acid enhances the redox capability of PGA-Mn-TP04, effectively reducing mitochondrial damage caused by mitochondrial reactive oxygen species. Moreover, PGA-Mn-TP04 restores mitochondrial function by facilitating the fusion of mitochondria and minimizing their fission, thereby sustaining the vitality of nucleus pulposus cells. In the rat IVDD model, PGA-Mn-TP04 maintained intervertebral disc height and nucleus pulposus tissue hydration. It offers a nonoperative treatment approach for IVDD and other skeletal muscle diseases resulting from mitochondrial dysfunction, presenting an alternative to traditional surgical interventions.

Optimized silicate nanozymes with atomically incorporated iron and manganese for intratumoral coordination-enhanced once-for-all catalytic therapy

Although plant-derived cancer therapeutic products possess great promise in clinical translations, they still suffer from quick degradation and low targeting rates. Herein, based on the oxygen vacancy (OV)-immobilization strategy, an OV-enriched biodegradable silicate nanoplatform with atomically dispersed Fe/Mn active species and polyethylene glycol modification was innovated for loading gallic acid (GA) (noted as FMMPG) for intratumoral coordination-enhanced multicatalytic cancer therapy. The OV-enriched FMMPG nanozymes with a narrow band gap (1.74 eV) can be excited by a 650 nm laser to generate reactive oxygen species. Benefiting from the Mn-O bond in response to the tumor microenvironment (TME), the silicate skeleton in FMMPG collapses and completely degrades after 24 h. The degraded metal M (M = Fe, Mn) ions and released GA can in situ produce a stable M-GA nanocomplex at tumor sites. Importantly, the formed M-GA with strong reductive ability can transform H2O2 into the fatal hydroxyl radical, causing serious oxidative damage to the tumor. The released Fe3+ and Mn2+ can serve as enhanced contrast agents for magnetic resonance imaging, which can track the chemodynamic and photodynamic therapy processes. The work offers a reasonable strategy for a TME-responsive degradation and intratumoral coordination-enhanced multicatalytic therapy founded on bimetallic silicate nanozymes to achieve desirable tumor theranostic outcomes.

Smart responsive Fe/Mn nanovaccine triggers liver cancer immunotherapy via pyroptosis and pyroptosis-boosted cGAS-STING activation

BACKGROUND

The prognosis for hepatocellular carcinoma (HCC) remains suboptimal, characterized by high recurrence and metastasis rates. Although metalloimmunotherapy has shown potential in combating tumor proliferation, recurrence and metastasis, current apoptosis-based metalloimmunotherapy fails to elicit sufficient immune response for HCC.

RESULTS

A smart responsive bimetallic nanovaccine was constructed to induce immunogenic cell death (ICD) through pyroptosis and enhance the efficacy of the cGAS-STING pathway. The nanovaccine was composed of manganese-doped mesoporous silica as a carrier, loaded with sorafenib (SOR) and modified with MIL-100 (Fe), where Fe3+, SOR, and Mn2+ were synchronized and released into the tumor with the help of the tumor microenvironment (TME). Afterward, Fe3+ worked synergistically with SOR-induced immunogenic pyroptosis (via both the classical and nonclassical signaling pathways), causing the outflow of abundant immunogenic factors, which contributes to dendritic cell (DC) maturation, and the exposure of double-stranded DNA (dsDNA). Subsequently, the exposed dsDNA and Mn2+ jointly activated the cGAS-STING pathway and induced the release of type I interferons, which further led to DC maturation. Moreover, Mn2+-related T1 magnetic resonance imaging (MRI) was used to visually evaluate the smart response functionality of the nanovaccine.

CONCLUSION

The utilization of metallic nanovaccines to induce pyroptosis-mediated immune activation provides a promising paradigm for HCC treatment.

Defect-Engineering-Mediated Long-Lived Charge-Transfer Excited-State in Fe-Gallate Complex Improves Iron Cycle and Enables Sustainable Fenton-Like Reaction

Fenton reactions are inefficient because the Fe(II) catalyst cannot be recycled in time due to the lack of a rapid electron transport pathway. This results in huge H2 O2 wastage in industrial applications. Here, it is shown that a sustainable heterogeneous Fenton system is attainable by enhancing the ligand-to-metal charge-transfer (LMCT) excited-state lifetime in Fe-gallate complex. By engineering oxygen defects in the complex, the lifetime is improved from 10-90 ps. The lengthened lifetime ensures sufficient concentrations of excited-states for an efficient Fe cycle, realizing previously unattainable H2 O2 activation kinetics and hydroxyl radical (• OH) productivity. Spectroscopic and electrochemical studies show the cyclic reaction mechanism involves in situ Fe(II) regeneration and synchronous supply of oxygen atoms from water to recover dissociated Fe─O bonds. Trace amounts of this catalyst effectively destroy two drug-resistant bacteria even after eight reaction cycles. This work reveals the link among LMCT excited-state lifetime, Fe cycle, and catalytic activity and stability, with implications for de novo design of efficient and sustainable Fenton-like processes.

Targeted Delivery of Active Sites by Oxygen Vacancy-Engineered Bimetal Silicate Nanozymes for Intratumoral Aggregation-Potentiated Catalytic Therapy

Biodegradable silicate nanoconstructs have aroused tremendous interest in cancer therapeutics due to their variable framework composition and versatile functions. Nevertheless, low intratumoral retention still limits their practical application. In this study, oxygen vacancy (OV)-enriched bimetallic silicate nanozymes with Fe-Ca dual active sites via modification of oxidized sodium alginate and gallic acid (GA) loading (OFeCaSA-V@GA) were developed for targeted aggregation-potentiated therapy. The band gap of silica markedly decreased from 2.76 to 1.81 eV by codoping of Fe3+ and Ca2+, enabling its excitation by a 650 nm laser to generate reactive oxygen species. The OV that occurred in the hydrothermal synthetic stage of OFeCaSA-V@GA can anchor the metal ions to form an atomic phase, offering a massive fabrication method of single-atom nanozymes. Density functional theory results reveal that the Ca sites can promote the adsorption of H2O2, and Fe sites can accelerate the dissociation of H2O2, thereby realizing a synergetic catalytic effect. More importantly, the targeted delivery of metal ions can induce a morphological transformation at tumor sites, leading to high retention (the highest retention rate is 36.3%) of theranostic components in tumor cells. Thus, this finding may offer an ingenious protocol for designing and engineering highly efficient and long-retention nanodrugs.

Strategies to engineer various nanocarrier-based hybrid catalysts for enhanced chemodynamic cancer therapy

Chemodynamic therapy (CDT) is a newly developed cancer-therapeutic modality that kills cancer cells by the highly toxic hydroxyl radical (˙OH) generated from the in situ triggered Fenton/Fenton-like reactions in an acidic and H2O2-overproduced tumor microenvironment (TME). By taking the advantage of the TME-activated catalytic reaction, CDT enables a highly specific and minimally-invasive cancer treatment without external energy input, whose efficiency mainly depends on the reactant concentrations of both the catalytic ions and H2O2, and the reaction conditions (including pH, temperature, and amount of glutathione). Unfortunately, it suffers from unsatisfactory therapy efficiency for clinical application because of the limited activators (i.e., mild acid pH and insufficient H2O2 content) and overexpressed reducing substance in TME. Currently, various synergistic strategies have been elaborately developed to increase the CDT efficiency by regulating the TME, enhancing the catalytic efficiency of catalysts, or combining with other therapeutic modalities. To realize these strategies, the construction of diverse nanocarriers to deliver Fenton catalysts and cooperatively therapeutic agents to tumors is the key prerequisite, which is now being studied but has not been thoroughly summarized. In particular, nanocarriers that can not only serve as carriers but are also active themselves for therapy are recently attracting increasing attention because of their less risk of toxicity and metabolic burden compared to nanocarriers without therapeutic capabilities. These therapy-active nanocarriers well meet the requirements of an ideal therapy system with maximum multifunctionality but minimal components. From this new perspective, in this review, we comprehensively summarize the very recent research progress on nanocarrier-based systems for enhanced CDT and the strategies of how to integrate various Fenton agents into the nanocarriers, with particular focus on the studies of therapy-active nanocarriers for the construction of CDT catalysts, aiming to guide the design of nanosystems with less components and more functionalities for enhanced CDT. Finally, the challenges and prospects of such a burgeoning cancer-theranostic modality are outlooked to provide inspirations for the further development and clinical translation of CDT.

Nanomedicine-based co-delivery of a calcium channel inhibitor and a small molecule targeting CD47 for lung cancer immunotherapy

Pro-tumoral macrophages in lung tumors present a significant challenge in immunotherapy. Here, we introduce a pH-responsive nanomedicine approach for activating anti-tumoral macrophages and dendritic cells. Using a layered double hydroxide nanosheet carrier, we co-deliver a T-type calcium channel inhibitor (TTA-Q6) and a CD47 inhibitor (RRX-001) into lung tumors. In the tumor acidic environment, TTA-Q6 is released, disrupting cancer cell calcium uptake, causing endoplasmic reticulum stress and inducing calreticulin transfer to the cell surface. Surface calreticulin activates macrophages and triggers dendritic cell maturation, promoting effective antigen presentation and therefore activating antitumor T cells. Simultaneously, RRX-001 reduces CD47 protein levels, aiding in preventing immune escape by calreticulin-rich cancer cells. In lung tumor models in male mice, this combined approach shows anti-tumor effects and immunity against tumor re-exposure, highlighting its potential for lung cancer immunotherapy.

Nebulized Therapy of Early Orthotopic Lung Cancer by Iron-Based Nanoparticles: Macrophage-Regulated Ferroptosis of Cancer Stem Cells

Cancer stem cells (CSCs) within protumorigenic microlesions are a critical driver in the initiation and progression of early stage lung cancer, where immune cells provide an immunosuppressive niche to strengthen the CSC stemness. As the mutual interactions between CSCs and immune cells are increasingly recognized, regulating the immune cells to identify and effectively eliminate CSCs has recently become one of the most attractive therapeutic options, especially for abundant tumor-associated macrophages (TAMs). Herein, we developed a nebulized nanocatalytic medicine strategy in which iron-based nanoparticle-regulated TAMs effectively target CSC niches and trigger CSC ferroptosis in the early stage of lung cancer. Briefly, the iron-based nanoparticles can effectively accumulate in lung cancer microlesions (minimum 122 μm in diameter) through dextran-mediated TAM targeting by nebulization administration, and as a result, nanoparticle-internalized TAMs can play a predominant role of the iron factory in elevating the iron level surrounding CSC niches and destroying redox equilibrium through downregulating glucose-6-phosphate metabolite following their lysosomal degradation and iron metabolism. The altered microenvironment results in the enhanced sensitivity of CSCs to ferroptosis due to their high expression of the CD44 receptor mediating iron endocytosis. In an orthotopic mouse model of lung cancer, the initiation and progression of early lung cancer are significantly suppressed through ferroptosis-induced stemness reduction of CSCs by nebulization administration. This work presents a nebulized therapeutic strategy for early lung cancer through modulation of communications between TAMs and CSCs, which is expected to be a general approach for regulating primary microlesions and micrometastatic niches of lung cancer.

Amplified Ferroptosis and Apoptosis Facilitated by Differentiation Therapy Efficiently Suppress the Progression of Osteosarcoma

Osteosarcoma (OS) is the most frequent osseous neoplasm among young people aged 10-20. Currently, the leading treatment for osteosarcoma is a combination of surgery and chemotherapy. However, the mortality remains high due to chemoresistance, metastasis, and recurrence, attributing to the existence of cancer stem cells (CSCs) as reported. To target CSCs, differentiation therapy attracts increasing attention, inducing CSCs to bulk tumor cells with elevated reactive oxygen species (ROS) levels and less chemoresistance. Moreover, increasing studies have implied that ferroptosis is a promising approach to eliminating cancer cells through eliciting oxidative damage and subsequent apoptosis, effectively bypassing chemoresistance. Here, a cancer-cell-membrane-decorated biocompatible formulation (GA-Fe@CMRALi liposome) is constructed to combat OS efficiently by combining distinct differentiation and ferroptosis therapies through magnified ROS-triggered ferroptosis and apoptosis with homologous target capability to tumor sites. The combinational approach exhibited favorable therapeutic efficacy against OS in vitro and in vivo. Impressively, the potential mechanisms are revealed by mRNA sequencing. This study provides a tactical design and typical paradigm of the synergized differentiation and ferroptosis therapies to combat heterogeneous OS.

A Nanomedicine-Enabled Ion-Exchange Strategy for Enhancing Curcumin-Based Rheumatoid Arthritis Therapy

Curcumin (Cur) has been clinically used for rheumatoid arthritis treatment by the means of reactive oxygen species (ROS) scavenging and immune microenvironment regulation. However, this compound has a poor water solubility and moderate antioxidative activity, favoring no further broadened application. Metal complexes of curcumin such as zinc-curcumin (Zn-Cur) features enhanced water solubilities, while copper-curcumin (Cu-Cur) shows a higher antioxidant activity but lower solubility than Zn-Cur. Based on their inherent biological properties, this work proposes a nanomedicine-based ion-exchange strategy to enhance the efficacy of Cur for rheumatoid arthritis treatment. Copper silicate nanoparticles with hollow mesoporous structure were prepared to load water-soluble Zn-Cur for constructing a composite nanomedicine, which can degrade in acidic microenvironment of arthritic region, releasing Cu2+ and Zn-Cur. Cu2+ then substitute for Zn2+ in Zn-Cur to form Cu-Cur with a significantly enhanced antioxidative effect, capable of efficiently scavenging ROS in M1 macrophages, promoting their transition to an anti-inflammatory M2 phenotype. In addition, the silicate released after nanocarrier degradation and the Zn2+ released after ion exchange reaction synergistically promote the biomineralization of osteoblasts. This work provides a new approach for enhancing the antiarthritic effect of Cur via an ion-exchange strategy.

Cascade strategy for glucose oxidase-based synergistic cancer therapy using nanomaterials

Nanomaterial-based cancer therapy faces significant limitations due to the complex nature of the tumor microenvironment (TME). Starvation therapy is an emerging therapeutic approach that targets tumor cell metabolism using glucose oxidase (GOx). Importantly, it can provide a material or environmental foundation for other diverse therapeutic methods by manipulating the properties of the TME, such as acidity, hydrogen peroxide (H2O2) levels, and hypoxia degree. In recent years, this cascade strategy has been extensively applied in nanoplatforms for ongoing synergetic therapy and still holds undeniable potential. However, only a few review articles comprehensively elucidate the rational designs of nanoplatforms for synergetic therapeutic regimens revolving around the conception of the cascade strategy. Therefore, this review focuses on innovative cascade strategies for GOx-based synergetic therapy from representative paradigms to state-of-the-art reports to provide an instructive, comprehensive, and insightful reference for readers. Thereafter, we discuss the remaining challenges and offer a critical perspective on the further advancement of GOx-facilitated cancer treatment toward clinical translation.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

Defect Engineering in Biomedical Sciences

With the promotion of nanochemistry research, large numbers of nanomaterials have been applied in vivo to produce desirable cytotoxic substances in response to endogenous or exogenous stimuli for achieving disease-specific therapy. However, the performance of nanomaterials is a critical issue that is difficult to improve and optimize under biological conditions. Defect-engineered nanoparticles have become the most researched hot materials in biomedical applications recently due to their excellent physicochemical properties, such as optical properties and redox reaction capabilities. Importantly, the properties of nanomaterials can be easily adjusted by regulating the type and concentration of defects in the nanoparticles without requiring other complex designs. Therefore, this tutorial review focuses on biomedical defect engineering and briefly discusses defect classification, introduction strategies, and characterization techniques. Several representative defective nanomaterials are especially discussed in order to reveal the relationship between defects and properties. A series of disease treatment strategies based on defective engineered nanomaterials are summarized. By summarizing the design and application of defective engineered nanomaterials, a simple but effective methodology is provided for researchers to design and improve the therapeutic effects of nanomaterial-based therapeutic platforms from a materials science perspective.

Injectable thermo-sensitive hydrogel loaded hollow copper sulfide nanoparticles for ROS burst in TME and effective tumor treatment

Introduction: Lung cancer the most prevalent cause of cancer-related deaths, and current therapies lack sufficient specificity and efficacy. This study developed an injectable thermosensitive hydrogel harboring hollow copper sulfide nanoparticles and β-lapachone (Lap) (CLH) for lung tumor treatment. Methods: The hydrogel-encapsulated CLH system can remotely control the release of copper ions (Cu2+) and drugs using photothermal effects for non-invasive controlled-release drug delivery in tumor therapy. The released Cu2+ consumes the overexpressed GSH in TME and the generated Cu+ further exploits the TME characteristics to initiate nanocatalytic reactions for generating highly toxic hydroxyl radicals. In addition, in cancer cells overexpressing Nicotinamide adenine dinucleotide (phosphate): quinone oxidoreductase 1 (NQO1), Lap can catalyze the generation of hydrogen peroxide (H2O2) through futile redox cycles. H2O2 is further converted into highly toxic hydroxyl radicals via the Fenton-like reaction, leading to a burst of reactive oxygen species in TME, which further enhances the therapeutic effect of chemokines. Results: Analysis of the antitumor efficacy in a subcutaneous A549 lung tumor model mice showed a significant delay in tumor growth and no systemic toxicity was detected. Discussion: In conclusion, we have established a CLH nanodrug platform that enables efficient lung tumor therapy through combined photothermal/chemodynamic therapy (CDT) treatment and self-supplying H2O2 to achieve cascade catalysis, leading to explosive amplification of oxidative stress.

Gastric Acid-Responsive ROS Nanogenerators for Effective Treatment of Helicobacter pylori Infection without Disrupting Homeostasis of Intestinal Flora

Helicobacter pylori (H. pylori) has infected more than half of the world's population, and is the major cause of gastric cancer. The efficacy of standard antibiotic-based triple therapy is declining due to drug resistance development. Herein, a pH-responsive reactive oxygen species (ROS) nanogenerator (Fe-HMME@DHA@MPN) composed of acid-responsive metal polyphenol network (MPN) shell and mesoporous metal-organic nanostructure core [Fe-HMME (hematoporphyrin monomethyl ether, sonosensitizer)] loaded with dihydroartemisinin (DHA) is reported. These nanoparticles generate more ROS singlet oxygen than sonosensitizer HMME under ultrasonication, and this sonodynamic process is fueled by oxygen generated through Fenton/Fenton-like reactions of the degraded product in gastric acid Fe (II) and hydrogen peroxide (H₂ O₂ ) in the infection microenvironment. The encapsulated DHA, as a hydroperoxide source, is found to enhance the peroxidase-like activity of the Fe-HMME@DHA@MPN to generate ROS hydroxyl radical, beneficial for the microenvironment without sufficient H₂ O₂ . In vitro experiments demonstrate that the ROS nanogenerators are capable of killing multidrug-resistant H. pylori and removing biofilm, and ROS nanogenerators show high therapeutic efficacy in a H. pylori infection mouse model. Unlike the triple therapy, the nanogenerators display negligible side effects toward the normal gut microbiota. Taken together, these self-enhanced ROS nanogenerators have a great potential for treatment of H. pylori infection.

In Situ Separable Nanovaccines with Stealthy Bioadhesive Capability for Durable Cancer Immunotherapy

Because of tumor heterogeneity and the immunosuppressive tumor microenvironment, most cancer vaccines typically do not elicit robust antitumor immunological responses in clinical trials. In this paper, we report findings about a bioadhesive nanoparticle (BNP)-based separable cancer vaccine, FeSHK@B-ovalbumin (OVA), to target multi-epitope antigens and exert effective cancer immunotherapy. After the FeSHK@B-OVA "nanorocket" initiates the "satellite-rocket separation" procedure in the acidic tumor microenvironment, the FeSHK@B "launch vehicle" can amplify intracellular oxidative stress persistently. This procedure allows for bioadhesiveness-mediated prolonged drug retention within the tumor tissue and triggers the immunogenic death of tumor cells that transforms the primary tumors into antigen depots, which acts synergistically with the OVA "satellite" to trigger robust antigen-specific antitumor immunity. The cooperation of these two immunostimulants not only efficiently inhibits the primary tumor growth and provokes durable antigen-specific immune activation in vivo but also activates a long-term and robust immune memory effect to resist tumor rechallenge and metastasis. These results highlight the enormous potential of FeSHK@B-OVA to serve as an excellent therapeutic and prophylactic cancer nanovaccine. By leveraging the antigen depots in situ and the synergistic effect among multi-epitope antigens, such a nanovaccine strategy with stealthy bioadhesion may offer a straightforward and efficient approach to developing various cancer vaccines for different types of tumors.

MnOOH-Catalyzed Autoxidation of Glutathione for Reactive Oxygen Species Production and Nanocatalytic Tumor Innate Immunotherapy

The antioxidant system, signed with reduced glutathione (GSH) overexpression, is the key weapon for tumor to resist the attack by reactive oxygen species (ROS). Counteracting the ROS depletion by GSH is an effective strategy to guarantee the antitumor efficacy of nanocatalytic therapy. However, simply reducing the concentration of GSH does not sufficiently improve tumor response to nanocatalytic therapy intervention. Herein, a well-dispersed MnOOH nanocatalyst is developed to catalyze GSH autoxidation and peroxidase-like reaction concurrently and respectively to promote GSH depletion and H₂O₂ decomposition to produce abundant ROS such as hydroxyl radical (·OH), thereby generating a highly effective superadditive catalytic therapeutic efficacy. Such a therapeutic strategy that transforms endogenous "antioxidant" into "oxidant" may open a new avenue for the development of antitumor nanocatalytic medicine. Moreover, the released Mn²⁺ can activate and sensitize the cGAS-STING pathway to the damaged intratumoral DNA double-strands induced by the produced ROS to further promote macrophage maturation and M1-polarization, which will boost the innate immunotherapeutic efficacy. Resultantly, the developed simple MnOOH nanocatalytic medicine capable of simultaneously catalyzing GSH depletion and ROS generation, and mediating innate immune activation, holds great potential in the treatment of malignant tumors.

In-Tumor Biosynthetic Construction of Upconversion Nanomachines for Precise Near-Infrared Phototherapy

Targeted construction of therapeutic nanoplatforms in tumor cells with specific activation remains appealing but challenging. Here, we design a cancer-motivated upconversion nanomachine (UCNM) based on porous upconversion nanoparticles (p-UCNPs) for precise phototherapy. The nanosystem is equipped with a telomerase substrate (TS) primer and simultaneously encapsulates 5-aminolevulinic acid (5-ALA) and d-arginine (d-Arg). After coating with hyaluronic acid (HA), it can readily get into tumor cells, where 5-ALA induces efficient accumulation of protoporphyrin IX (PpIX) via the inherent biosynthetic pathway, and the overexpressed telomerase prolonged the TS to form G-quadruplexes (G4) for binding the resulting PpIX as a nanomachine. This nanomachine can respond to near-infrared (NIR) light and promote the active singlet oxygen (¹O₂) production due to the efficiency of Förster resonance energy transfer (FRET) between p-UCNPs and PpIX. Intriguingly, such oxidative stress can oxidize d-Arg into nitric oxide (NO), which relieves the tumor hypoxia and in turn improves the phototherapy effect. This in situ assembly approach significantly enhances targeting in cancer therapy and might be of considerable clinical value.

Selenide Heterostructure Nanosheets with Efficient Near-Infrared Photothermal Conversion for Therapy

Photothermal therapy has been regarded as one of promising ways for tumor treatment. However, nanoagents with highly efficient thermal conversion and good bio-compatibility are still needed to be developed in biomedicine. In this work, we prepared two-dimensional heterostructures with bismuth selenide and tungsten selenide nanosheets as photothermal nanoagents. Near-infrared photothermal conversion of selenide heterostructure nanosheets can reach up to 40.75% under 808 nm excitation. It is known that selenium is a critical element to human health. More importantly, our experiments with mice show that the heterostructure nanosheets have low toxicity and high biocompatibility both in vitro and in vivo. The nanoagents based on heterostructures can effectively realize photothermal tumor ablation. It is suggested that the developed selenide nanosheets have great potential application in cancer therapy.

Enhanced mild-temperature photothermal therapy by pyroptosis-boosted ATP deprivation with biodegradable nanoformulation

BACKGROUND

Mild-temperature photothermal therapy (mild PTT) is a safe and promising tumor therapeutic modality by alleviating the damage of healthy tissues around the tumor due to high temperature. However, its therapeutic efficiency is easily restricted by heat shock proteins (HSPs). Thus, exploitation of innovative approaches of inhibiting HSPs to enhance mild PTT efficiency is crucial for the clinical application of PTT.

RESULTS

Herein, an innovative strategy is reported: pyroptosis-boosted mild PTT based on a Mn-gallate nanoformulation. The nanoformulation was constructed via the coordination of gallic acid (GA) and Mn²⁺. It shows an acid-activated degradation and releases the Mn²⁺ and GA for up-regulation of reactive oxygen species (ROS), mitochondrial dysfunction and pyroptosis, which can result in cellular ATP deprivation via both the inhibiton of ATP generation and incresed ATP efflux. The reduction of ATP and accumulation of ROS provide a powerful approach for inhibiting the expression of HSPs, which enables the nanoformulation-mediated mild PTT.

CONCLUSIONS

Our in-vitro and in-vivo results demonstrate that this strategy of pyroptosis-assited PTT can achieve efficient mild PTT efficiency for osteosarcoma therapy.

Ignored role of polyphenol in boosting reactive oxygen species generation for polyphenol/chemodynamic combination therapy

Chemodynamic therapy (CDT) is a promising tumor-specific treatment, but still suffering insufficient reactive oxygen species (ROS) levels due to its limited efficacy of Fenton/Fenton-like reaction. Polyphenol, as a natural reductant, has been applied to promote the efficacy of Fenton/Fenton-like reactions; however, its intrinsic pro-apoptosis effects was ignored. Herein, a novel CDT/polyphenol-combined strategy was designed, based on Avenanthramide C-loaded dendritic mesoporous silica (DMSN)-Au/Fe₃O₄ nanoplatforms with folic acid modification for tumor-site targeting. For the first time, we showed that the nanocomplex (DMSNAF-AVC-FA) induced ROS production in the cytoplasm via Au/Fe₃O₄-mediated Fenton reactions and externally damaged the mitochondrial membrane; simultaneously, the resultant increased mitochondrial membrane permeability can facilitate the migration of AVC into mitochondrial, targeting the DDX3 pathway and impairing the electron transport chain (ETC) complexes, which significantly boosted the endogenous ROS levels inside the mitochondrial. Under the elevated oxidative stress level via both intra- and extra-mitochondrial ROS production, the maximum mitochondrial membrane permeability was achieved by up-regulation of Bax/Bcl-2, and thereby led to massive release of Cytochrome C and maximum tumor cell apoptosis via Caspase-3 pathway. As a result, the as-designed strategy achieved synergistic cytotoxicity to 4T1 tumor cells with the cell apoptosis rate of 99.12% in vitro and the tumor growth inhibition rate of 63.3% in vivo, while very minor cytotoxicity to normal cells with cell viability of 95.4%. This work evidenced that natural bioactive compounds are powerful for synergistically boosting ROS level, providing new insight for accelerating the clinical conversion progress of CDT with minimal side effects.

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A novel CDT/polyphenol-combined nanoplatform, DMSNAF-AVC-FA was designed.

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DMSNAF-AVC-FA induced ROS production and externally damaged mitochondrial membrane.

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DMSNAF-AVC-FA facilitated AVC targeting the DDX3 pathway and impairing ETC complexes.

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DMSNAF-AVC-FA achieved synergistic antitumor efficacy both in vitro and in vivo.

Precision Nanotoxicology in Drug Development: Current Trends and Challenges in Safety and Toxicity Implications of Customized Multifunctional Nanocarriers for Drug-Delivery Applications

The dire need for the assessment of human and environmental endangerments of nanoparticulate material has motivated the formulation of novel scientific tools and techniques to detect, quantify, and characterize these nanomaterials. Several of these paradigms possess enormous possibilities for applications in many of the realms of nanotoxicology. Furthermore, in a large number of cases, the limited capabilities to assess the environmental and human toxicological outcomes of customized and tailored multifunctional nanoparticles used for drug delivery have hindered their full exploitation in preclinical and clinical settings. With the ever-compounded availability of nanoparticulate materials in commercialized settings, an ever-arising popular debate has been egressing on whether the social, human, and environmental costs associated with the risks of nanomaterials outweigh their profits. Here we briefly review the various health, pharmaceutical, and regulatory aspects of nanotoxicology of engineered multifunctional nanoparticles in vitro and in vivo. Several aspects and issues encountered during the safety and toxicity assessments of these drug-delivery nanocarriers have also been summarized. Furthermore, recent trends implicated in the nanotoxicological evaluations of nanoparticulate matter in vitro and in vivo have also been discussed. Due to the absence of robust and rigid regulatory guidelines, researchers currently frequently encounter a larger number of challenges in the toxicology assessment of nanocarriers, which have also been briefly discussed here. Nanotoxicology has an appreciable and significant part in the clinical translational development as well as commercialization potential of nanocarriers; hence these aspects have also been touched upon. Finally, a brief overview has been provided regarding some of the nanocarrier-based medicines that are currently undergoing clinical trials, and some of those which have recently been commercialized and are available for patients. It is expected that this review will instigate an appreciable interest in the research community working in the arena of pharmaceutical drug development and nanoformulation-based drug delivery.

Multifunctional N,S-doped and methionine functionalized carbon dots for on-off-on Fe3+ and ascorbic acid sensing, cell imaging, and fluorescent ink applying

Fluorescent carbon dots (CDs) have been identified as potential nanosensors and attracted tremendous research interests in wide areas including anti-counterfeiting, environmental and biological sensing and imaging in considering of the attractive optical properties. In this work, we present a CDs based fluorescent sensor from polyvinylpyrrolidone, citric acid, and methionine as precursors by hydrothermal approach. The selective quantifying of Fe3+ and ascorbic acid (AA) are based on the fluorescent on-off-on process, in which the fluorescent quenching is induced by the coordination of the Fe3+ on the surface of the CDs, while the fluorescence recovery is mainly attributed to redox reaction between Fe3+ and AA, breaking the coordination and bringing the fluorescence back. Inspired by the good water solubility and biocompatibility, significant photostability, superior photobleaching resistance as well as high selectivity, sensitivity, and interference immunity, which are constructed mainly from the N,S-doping and methionine surface functionalization, the CDs have not only been employed as fluorescence ink in multiple anti-counterfeiting printing and confidential document writing or transmitting, but also been developed as promising fluorescence sensors in solution and solid by CDs doped test strips and hydrogels for effectively monitoring and removing of Fe3+ and AA in environmental aqueous solution. The CDs have been also implemented as effective diagnostic candidates for imaging and tracking of Fe3+ and AA in living cells, accelerating the understanding of their function and importance in related biological processes for the prevention and treatment specific diseases.

Electronic Supplementary Material

Supplementary material (fluorescence spectra: UV and Xe irradiation, TG, thermo stability, ionic strength, relationship between fluorescence responses at different concentrations of Fe3+ and AA, reaction time-dependent fluorescent responses; XPS spectra of CDs + Fe3+ and Fe3+@CDs + AA; structural characterization; equations about fluorescence lifetime, quantum yield and LOD; comparison of the CDs for the detection of Fe3+ and AA with reported methods; detection of Fe3+ and AA in real samples; absorption of Fe3+ in environmental samples and MTT assay results) is available in the online version of this article at 10.1007/s12274-022-5107-7.

Intratumoral synthesis of transformable metal-phenolic nanoaggregates with enhanced tumor penetration and retention for photothermal immunotherapy

Rationale: Effective photothermal therapy (PTT) remains a great challenge due to the difficulties of delivering photothermal agents with both deep penetration and prolonged retention at tumor lesion spatiotemporally. Methods: Here, we report an intratumoral self-assembled nanostructured aggregate named FerH, composed of a natural polyphenol and a commercial iron supplement. FerH assemblies possess size-increasing dynamic kinetics as a pseudo-stepwise polymerization from discrete nanocomplexes to microscale aggregates. Results: The nanocomplex can penetrate deeply into solid tumors, followed by prolonged retention (> 6 days) due to the in vivo growth into nanoaggregates in the tumor microenvironment. FerH performs a targeting ablation of tumors with a high photothermal conversion efficiency (60.2%). Importantly, an enhanced immunotherapeutic effect on the distant tumor can be triggered when co-administrated with checkpoint-blockade PD-L1 antibody. Conclusions: Such a therapeutic approach by intratumoral synthesis of metal-phenolic nanoaggregates can be instructive to address the challenges associated with malignant tumors.

A novel dual MoS2/FeGA quantum dots endowed injectable hydrogel for efficient photothermal and boosting chemodynamic therapy

Due to its responsiveness to the tumour microenvironment (TME), chemodynamic therapy (CDT) based on the Fenton reaction to produce cytotoxic reactive oxygen species (ROS) to destroy tumor has drawn more interest. However, the Fenton's reaction potential for therapeutic use is constrained by its modest efficacy. Here, we develop a novel injectable hydrogel system (FMH) on the basis of FeGA/MoS2 dual quantum dots (QDs), which uses near-infrared (NIR) laser in order to trigger the synergistic catalysis and photothermal effect of FeGA/MoS2 for improving the efficiency of the Fenton reaction. Mo4+ in MoS2 QDs can accelerate the conversion of Fe3+ to Fe2+, thereby promoting the efficiency of Fenton reaction, and benefiting from the synergistically enhanced CDT/PTT, FMH combined with NIR has achieved good anti-tumour effects in vitro and in vivo experiments. Furthermore, the quantum dots are easily metabolized after treatment because of their ultrasmall size, without causing any side effects. This is the first report to study the co-catalytic effect of MoS2 and Fe3+ at the quantum dot level, as well as obtain a good PTT/CDT synergy, which have implications for future anticancer research.

Biomolecule-based Stimuli-responsive Nanohybrids for Tumor-specific and Cascade-enhanced Synergistic Therapy

Poor tumor specificity is one of the key obstacles for clinical applications of nanotheranostic agents, consequently leading to serious side effects and unsatisfactory therapeutic efficacy. Herein, biomolecule-based nanohybrids (named as Hb-PDA-GOx) with multiple stimuli-responsiveness were designed and fabricated to enhance tumor-specific therapy. The nanohybrids embodied two proteins, i.e., hemoglobin (Hb) and glucose oxidase (GOx), which exhibited cascade catalytic activity selectively within the tumor microenvironment (TME). Specifically, GOx catalyzes the overexpressed glucose into gluconic acid and hydrogen peroxide (H₂O₂), which not only initiated starvation therapy (ST) through cutting off the nutrition supply for carcinoma cells, but also provided H₂O₂ for sequential Fenton reaction induced by Hb that generating biotoxic hydroxyl radicals (•OH) for chemodynamic therapy (CDT). Moreover, localized heat generation from polydopamine (PDA) in the nanohybrids can implement photothermal therapy (PTT) and reinforce the CDT efficacy. Excitingly, effective eradication of solid tumors and significant suppression of metastatic tumors growth were achieved by utilizing Hb-PDA-GOx as a versatile theranostic agent. All these results had been verified by in vitro and/or in vivo experiments. In light of the superior anticancer effects and insignificant systemic toxicity, the as-fabricated biomolecule-based nanohybrids could be employed as a promising agent for tumor-specific therapy. More importantly, the high biocompatibility and biodegradability of the selected biomolecules would facilitate subsequent clinical translation. STATEMENT OF SIGNIFICANCE: 1) A facile one-pot synthesis strategy was proposed to fabricate biomolecule-based tumor theranostic agent with high biocompatibility and biodegradability, which would facilitate subsequent clinical translation; 2) The as-developed theranostic agent was endowed with multiple stimuli-responsiveness for achieving tumor-specific and cascade-enhanced synergistic therapy; 3) The in vivo experiments demonstrated that the as-developed theranostic agent can not only effectively eradicate solid tumors, but also significantly suppress metastatic tumors growth.

Engineering dual catalytic nanomedicine for autophagy-augmented and ferroptosis-involved cancer nanotherapy

Chemodynamic therapy represents a distinct anti-tumor strategy by activating intratumoral chemical catalytic reactions to produce highly toxic reactive oxygen species (ROS) from non-/limited-toxic nanocatalysts. However, the low efficacy of ROS generation still remains a major challenge for further clinical translation. Herein, a liposomal nanosystem which simultaneously encapsulated copper peroxide nanodots (CPNs) and artemisinin (ART) was constructed for autophagy-enhanced and ferroptosis-involved cancer cell death owing to Cu-based dual catalytic strategy. To be specific, the CPN components, served as a H2O2 self-supplying platform, release H2O2 and Cu2+ under acidic tumor environment and endogenously generate .OH via Fenton-like reaction (catalytic reaction I). In addition, Cu2+ species catalyze ART components to produce ROS radicals (catalytic reaction II), further augmenting the intracellular oxidative damage and lipid peroxide accumulation, leading to cancer cell death. Specifically, ART also acted as a potent autophagy inducer increasing the level of intracellular iron pool through degradation of ferritin, which could promote cancer cell ferroptosis, producing the best antineoplastic effect. After accumulation into the tumor sites, ultrasound irradiation was applied to trigger the release of CPNs and ART from liposomal nanosystems, and amplify the efficacy of catalytic reaction for maximum therapeutic effect. Both in vitro and in vivo therapeutic outcomes suggest the outstanding autophagy-augmented ferroptosis-involved cancer-therapeutic efficacy, which was further corroborated by transcriptome sequencing. In this work, Cu was firstly proven to trigger ART to produce ROS species, but also provide a TME-responsive nanoplatform for potentially suppressing tumor growth by autophagy-augmented ferroptosis-involved cancer nanotherapy.

Mn2+ /Fe3+ /Co2+ and Tetrasulfide Bond Co-Incorporated Dendritic Mesoporous Organosilica as Multifunctional Nanocarriers: One-Step Synthesis and Applications for Cancer Therapy

Enriching the application of multifunctional dendritic mesoporous organosilica (DMOS) is still challenging in anti-cancer research. Herein, manganese ions, iron ions, or cobalt ions and tetrasulfide bonds are co-incorporated into the framework of DMOS to yield multifunctional nanoparticles denoted as Mn-DMOS, Fe-DMOS, or Co-DMOS by directly doping metal ions during the synthetic process. Due to co-incorporation of metal ions and tetrasulfide bonds, these designed nanocarriers have more functions rather than only for cargo delivery. As proof of concept, the nanocomposite is established based on Mn-DMOS as an efficient nanocarrier for indocyanine green (ICG) delivery and modification with polyethylene glycol. In the tumor microenvironment, the generated hydrogen sulfide (H₂ S) arising from the reaction between tetrasulfide bond and over-expressed glutathione (GSH) causes mitochondrial injury to reduce cellular respiration. The released Mn²⁺ from the rapidly decomposed nanocomposite catalyzes the endogenous hydrogen peroxide to produce oxygen (O₂ ). The photothermal effect from the released ICG initiated by the near-infrared light induces cancer cells apoptosis and simultaneously enhances the content of blood O₂ at tumor sites. Therefore, due to the GSH depletion and trimodal O₂ compensation, the photodynamic therapy efficiency of ICG has significantly improved. In brief, these designed nanocarriers will play advanced roles in cancer therapy.