In vivo three-dimensional multispectral photoacoustic imaging of dual enzyme-driven cyclic cascade reaction for tumor catalytic therapy

Multifunctional nanozymes: Promising applications in clinical diagnosis and cancer treatment

Cancer remains one of the greatest challenges in modern medicine. Traditional chemotherapy drugs often cause severe side effects, including nausea, vomiting, diarrhea, neurotoxicity, liver damage, and nephrotoxicity. In addition to these adverse effects, high recurrence and metastasis rates following treatment pose significant challenges for clinicians. There is an urgent need for novel therapeutic strategies to improve cancer treatment outcomes. In this context, nanozymes-artificial enzyme mimetics-have attracted considerable attention due to their unique advantages, including potent tumor-killing effects, enhanced biocompatibility, and reduced toxicity. Notably, nanozymes can dynamically monitor tumors through imaging and tracing. The multifunctional nanozyme (MN) is a promising research focus, integrating multiple catalytic activities, signal enhancement, sensing capabilities, and diverse modifications within a single nanozyme system. MNs can selectively target tumor regions, facilitating synergistic effects with other cancer therapies while enabling real-time imaging and tumor tracking. In this review, we first categorize MNs based on their composition and structural characteristics. We then discuss the primary mechanisms by which MNs exert their anticancer effects. Additionally, we review three types of MN biosensors and four MN-based therapeutic approaches applied in cancer treatment. Finally, we highlight the current challenges in MN research and provide an outlook on future developments in this field.

Visualization of HSP70-regulated mild-photothermal therapy for synergistic tumor treatment: a precise space-time mild-temperature photothermal ablation strategy

Mild-temperature photothermal therapy (MPTT) advances anticancer management by regulating reactive oxygen species (ROS) and lipid peroxides (LPO) to inhibit the overexpression of heat shock protein 70 (HSP70), thus decreasing the cellular heat resistance and increasing the efficacy of tumor ablation. However, formidable challenge remains on the traditional MPTT without imaging-guided optimal treatment time point, thus inadequate HSP70 blockage would potentially further diminish the effectiveness of MPTT. Herein, a novel biomimetic nanoprobe (Cu-ABTS@CCMs) is developed, based on encapsulating the multifunctional Cu nanoparticles and ROS-responsive 2,2'-azino-bis (3-ethylbenzothiazole-6- sulphonic acid) (ABTS) within cancer cell membranes (CCMs) to ensure second near-infrared photoacoustic (NIR-II PA) imaging-guided precise MPTT time point. The core Cu nanoparticles achieve highly effective HSP70 blockage via a nearly simultaneous cascade of photocatalytic O2-generation and dual ROS/LPO accumulation. Triggered by self-enhanced ROS/LPO up-regulation, the ABTS can correspondingly oxidize to ABTS•+, which further leads the real-time ratiometric PA signals (ABTS•+-PA730/Cu-PA960) that show highly accurate visualization of ROS and quantitatively convert into dynamic tracking of the changes in HSP70 blockage. The intelligent dual-modality imaging information will provide more possibilities for the optimal time-point and site-specificity of MPTT and potential avenues for the development of clinical breast cancer treatments.

Refining Single-Atom Catalytic Kinetics for Tumor Homologous-Targeted Catalytic Therapy

Single-atom nanozymes (SAzymes) hold significant potential for tumor catalytic therapy, but their effectiveness is often compromised by low catalytic efficiency within tumor microenvironment. This efficiency is mainly influenced by key factors including hydrogen peroxide (H2O2) availability, acidity, and temperature. Simultaneous optimization of these key factors presents a significant challenge for tumor catalytic therapy. In this study, we developed a comprehensive strategy to refine single-atom catalytic kinetics for enhancing tumor catalytic therapy through dual-enzyme-driven cascade reactions. Iridium (Ir) SAzymes with high catalytic activity and natural enzyme glucose oxidase (GOx) were utilized to construct the cascade reaction system. GOx was loaded by Ir SAzymes due to its large surface area. Then, the dual-enzyme-driven cascade reaction system was modified by cancer cell membranes for improving biocompatibility and achieving tumor homologous targeting ability. GOx catalysis reaction could produce abundant H2O2 and lower the local pH, thereby optimizing key reaction-limiting factors. Additionally, upon laser irradiation, Ir SAzymes could raise local temperature, further enhancing the catalytic efficiency of dual-enzyme system. This comprehensive optimization maximized the performance of Ir SAzymes, significantly improving the efficiency of catalytic therapy. Our findings present a strategy of refining single-atom catalytic kinetics for tumor homologous-targeted catalytic therapy.

Mesoporous Gold Nanospheres Confined Platinum Nanoclusters as Robust ROS and Oxygen Nanogenerators for NIR-II Hyperthermia Cancer Therapy

While massive studies are focused on platinum (Pt)-based nanozyme for antitumor therapies, their therapeutic efficiency is deficient due to the weak catalytic activity in the highly complex tumor microenvironment. Herein, mesoporous gold nanospheres confined platinum nanoclusters (MGNSs@Pt) as robust hydroxyl radical and oxygen nanogenerators are achieved for multimodal therapies. Benefiting from the confinement effect of the mesopores in the MGNSs, the Pt nanoclusters (Pt NCs) demonstrate enhanced stability and catalytic activity, with a catalytic constant (Kcat) of 1.42 × 106 s-1, which is 2 and 5 orders magnitude higher than Kcat values of Pt-decorated non-porous gold nanoparticles and pure Pt NCs respectively. Density functional theory (DFT) calculations reveal the proper interaction of intermediates contributes to the ultra-high catalytic activity of MGNSs@Pt. Meanwhile, owing to the local surface plasmon resonance (LSPR) effect in the second near-infrared (NIR-II) bio-window of MGNSs, the nanozymes exhibited high photothermal conversion efficiency up to 43.4%, which enhanced the nanocatalytic damage on cancer cells. This process can induce robust oxidative stress and oxygenation within the tumor, thereby activating the apoptosis pathway for tumor eradication by mitochondrial dysfunction, cell membrane disruption, HIF-1α downregulation as well as caspase 3 activation, which pave the way for multimodal and effective cancer treatment.

Oxygen-regulated enzymatic nanoplatform for synchronous intervention in glycolysis and oxidative phosphorylation to augment antitumor therapy

Tumor cells typically undergo metabolic reprogramming to obtain substantial energy via glycolysis and oxidative phosphorylation (OXPHOS). Intervening in this reprogramming is expected to have therapeutic effects, but simultaneous intervention in these two metabolic pathways is challenging. Herein, we developed an "open-source and throttling" oxygen (O₂) modulation strategy by which we can simultaneously intervene in these two metabolic pathways. Our O₂ modulation nanoplatform (denoted as OAGO) is fabricated via the self-assembly of glucose oxidase (GOx) and oligomycin A (OA) and is coated with bacterial outer membrane vesicles (OMVs). OAGO elicits simultaneous GOx-mediated inhibition of glycolysis and OA-induced inhibition of OXPHOS. The resulting production of GOx-catalyzed hydrogen peroxide leads to oxidative stress, which exacerbates the inhibition of mitochondrial function. Meanwhile, OA reduces intratumoral O₂ consumption (i.e., the "throttling" strategy), and OMVs increase the tumor blood O₂ level (i.e., the "open-source" strategy). This results in an increase in O₂ levels for GOx catalysis, thereby exacerbating energy consumption. In addition, OMVs increase intratumoral OAGO accumulation and enable photothermal therapy in the 4T1 mouse model, which also raises the tumor blood O₂ level and benefits GOx catalysis. This synchronous intervention in two metabolic pathways alongside O₂ modulation constitutes a promising approach for efficient antitumor therapy.

Triterpenoids with inhibitory effects on lipid accumulation from Ganoderma lucidum

Eight undescribed lanostane-type triterpenes (1-8) and twenty-seven known analogues (9-35) were isolated from the fruiting bodies of cultivated Ganoderma lucidum. The chemical structures of these compounds were elucidated using a combination of spectroscopic techniques. Ganosinenic acid D (1) and ganosinenic acid E (2) were identified as rare pentacyclic triterpenoids with an unusual four-membered carbon ring motif. The inhibitory effects of all compounds on lipid accumulation were evaluated in oleic acid (OA)-induced HepG2 cells. Among the tested compounds, ganolucidic acid G (7), lucidenic acid N (9), methyl lucidenate M (29) showed moderate inhibitory effects. Furthermore, lucidenic acid N inhibited lipid accumulation in a dose-dependent manner. The structure-activity relationship analysis revealed enhanced efficacy in side chain-degraded C27 nor-triterpenoids compared to C24 and C30 analogs.

Natural polymer chitosan-based hydrogels can enhance mechanical properties and produce H2S gas by UV-light to treat scalded wound

The healing of deep second- and third-degree scald wounds is frequently impaired by inflammation, oxidative stress, vascular damage, and neural injury, creating substantial challenges for clinical wound management. To address this, we developed a novel hydrogel dressing strategy utilizing alpha-lipoic acid-modified chitosan (LAMC) combined with a four-armed polyethylene glycol derivative (PEG-NHS). This hydrogel achieves rapid wound coverage through its inherent adhesive properties, followed by ultraviolet (UV)-triggered secondary cross-linking to enhance mechanical stability (average compression strength reaches about 173 KPa). Concurrently, the hydrogel releases hydrogen sulfide (H₂S) gas, which exerts anti-inflammatory, antioxidant, pro-angiogenic, and neuroregenerative effects. Experimental data demonstrated that a 400 μL disulfide-containing hydrogel generated 28.89 ± 3.70 μM H₂S within 30 s of UV exposure. In vivo testing revealed a wound healing rate exceeding 95 % by day 14 in UV-treated hydrogel groups. The combination of these materials and their functional advantages provide a promising new way for the postoperative repair of severe scalded wounds.

Bioengineered nanomaterials for dynamic diagnostics in vivo

In vivo diagnostics obtains real-time physiological information directly from the site of interest in a patient's body, providing more accurate disease diagnosis compared with ex vivo diagnostics. Particularly, in vivo dynamic diagnostics allows the continuous monitoring of physiological signals over a period of time, offering deeper insights into disease pathogenesis and progression. However, achieving in situ dynamic diagnostics in deep tissues presents challenges related to energy and signal penetration as well as dynamic monitoring. Bioengineered nanomaterials serve as an ideal platform for in vivo dynamic diagnostics, leveraging energy conversion and biofunctionalization to enable continuous acquisition of physiological information across temporal and spatial scales. In this review, with reference to the studies from the last five years, we summarize the fundamental components that are essential for dynamic diagnosis in vivo. Firstly, an input energy source with high tissue penetration is needed, such as near-infrared (NIR) light, X-rays, magnetic field and ultrasound. Secondly, a nanomaterial class that is responsive to such an energy source to provide a readable output signal is chosen. Thirdly, bioengineered nanoprobes are designed to exhibit spatial, temporal or spatiotemporal changes in the output signal. Finally, different methods are used to analyse the output signal of nanoprobes, such as detecting changes in optical, radiation, magnetic and ultrasound signals. This review also discusses the obstacles and potential solutions for advancing these bioengineered nanomaterials toward clinical translational applications.

Elongated Magnetic Nanorobots with Multi-Enzymatic Cascades for Active In Vivo Tumor Targeting and Enhanced Chemodynamic Therapy

Targeted delivery of therapeutic agents to malignant tissues is crucial for enhancing clinical outcomes and reducing side effects. Magnetic nanorobots (MNRs) present a promising strategy for controlled delivery, leveraging external magnetic fields to achieve precise in vivo targeting. This work develops elongated MNRs comprising linearly arranged magnetic nanoparticles linked by metal-polyphenol complexes (MPCs) for magnetic-field-directed active tumor targeting and synergistic tumor therapy. The MNRs are created by assembling 30 nm Fe3O4 nanoparticles, tannic acid, and ferrous ions (Fe2+) under a uniform magnetic field, resulting in elongated chain-like structures fixed by MPCs, which also promotes peroxidase-like activity. These structures show a greater magnetic response than individual nanoparticles, offering flexibility in magnetic manipulation. The MPCs coating allows tailored surface modifications with glucose oxidase, copper ions (Cu2+), and human serum albumin (HSA), producing colloidally stable MNRs with a built-in multienzymatic cascade (MNRs@GOx/Cu/HSA) that consumes glucose, generates •OH, and depletes the antioxidant glutathione (GSH). Collectively, surface-engineered multifunctional MNRs demonstrate improved in vivo tumor targeting driven by external magnetic fields, leading to efficient localized chemodynamic therapy. The tailored structural and functional properties of the developed MNRs render them suitable for targeted cargo delivery, minimally invasive surgery, and localized treatments in disease sites.

Nanozyme Cascade Self-Powered H2O2 Strategy for Chemiluminescence Array Sensor to Monitor and Deactivate Multiple Bacteria

Early warning and deactivation of multiple bacteria are highly desirable to prevent pathogen-responsible bacterial infectious illnesses. Here, we developed a nanozyme cascade self-powered H2O2 strategy for a chemiluminescence (CL) array immunosensor to enable high-throughput and simultaneous monitoring of multiple bacteria as well as their deactivation. Specifically, a novel ZIF-67@CoFePBA yolk-shell nanozyme was synthesized through a dissociation and re-coordination mechanism, exhibiting significantly enhanced peroxidase (POD)-like activity due to the confinement and synergistic effects. ZIF-67@CoFePBA nanozyme was utilized to immobilize glucose oxidase (GOx) for constructing the nanozyme cascade self-powered H2O2 system. ZIF-67@CoFePBA nanozyme can catalyze in-situ H2O2 to produce hydroxyl radicals (·OH), resulting in stable glow-type CL to construct array immunosensors without exogenous H2O2. The self-powered CL array sensor was exploited to simultaneously detect numerous bacteria with wide linear ranges of 1.5×10-1.5×107 CFU/mL for Staphylococcus aureus and 1.5×102-1.5×107 CFU/mL for Escherichia coli. Furthermore, the generated ·OH can destroy the internal structure of the bacteria and effectively eliminate them. This study provides a promising insight into the design of self-powered H2O2 sensors for high-throughput and simultaneous detection of multiple bacteria and their subsequent deactivation.

Priming of cancer-immunity cycle by alleviating hypoxia-induced ferroptosis resistance and immunosuppression

Stimulating a robust cancer-immunity cycle (CIC) holds promising potential for eliciting potent and enduring immune responses for cancer immunotherapy. However, designing a therapeutic nanomaterial capable of both enhancing tumor immunogenicity and mitigating immunosuppression is challenging and often associated with complicated design paradigms and immune-related adverse effects. Herein, a multienzyme-mimetic alloy nanosheet incorporating palladium (Pd) and iron (Fe) is developed, which can prime effective CIC by overcoming ferroptosis resistance for enhancing tumor immunogenicity and reprograming the tumor microenvironment for enhanced second near-infrared (NIR-II) photoimmunotherapy. The nanosheets accumulate in tumors when administered intravenously and counteract hypoxia through catalase-like oxygen production and subsequent reduction of hypoxia-inducible factor-1α, M2-like macrophages, regulatory T-cell, and programmed death-ligand 1 (PD-L1) expression. The surface plasmon resonance of the nanosheets enables NIR-II phototherapy and photoacoustic imaging, coupling with its ferroptosis and tumor microenvironment reprogram properties to synergize with anti-PD-L1 checkpoint blockade therapy to achieve satisfactory antitumor outcome. This study offers a strategy for localized tumor treatment and boosting the CIC through a straightforward and inexpensive nanomaterial design.

Cobalt Single-Atom Intercalation in Molybdenum Disulfide Enhances Piezocatalytic and Enzyodynamic Activities for Advanced Cancer Therapeutics

Piezoelectric semiconductor nanomaterials have attracted considerable interest in piezocatalytic tumor treatment. However, piezocatalytic therapy encounters obstacles such as suboptimal piezoelectric responses, rapid electron-hole recombination, inefficient energy harvesting, and the complexities of the tumor microenvironment. In this study, sulfur vacancy-engineered cobalt (Co) single-atom doped molybdenum disulfide (SA-Co@MoS2) nanoflowers are strategically designed, which exhibit enhanced piezoelectric effects. Specifically, the introduction of Co single atom not only induces lattice distortion and out-of-plane polarization but also leads to the formation of numerous sulfur vacancies. These changes collectively narrow the intrinsic bandgap of the material, facilitating effective separation and migration of charge carriers, and enabling efficient production of reactive oxygen species under ultrasound stimulation. Additionally, the SA-Co@MoS2 nanoflowers demonstrate improved enzymatic activity and exhibit glutathione depletion capabilities attributed to the mixed valence states of Co, intensifying oxidative stress in tumor cells, and leading to cell cycle arrest and apoptosis, while the inactivation of glutathione peroxidase 4 induces ferroptosis. Both in vitro and in vivo results indicate that SA-Co@MoS2 nanoflowers can significantly eliminate tumor cells. This study offers valuable insights into the exploration of single-atom doping-enhanced piezoelectric sonosensitizers for cancer treatment, potentially paving the way for advancements in the field of piezocatalytic synergistic enzyodynamic therapy.

Self-propelling intelligent nanomotor: A dual-action photothermal and starvation strategy for targeted deep tumor destruction

Delivering nanoparticles to deep tumor tissues while maintaining high therapeutic efficacy and minimizing damage to surrounding tissues has long posed a significant challenge. To address this, we have developed innovative self-propelling bowl-shaped nanomotors MSLA@GOx-PDA composed of mesoporous silica loaded with l-arginine and polydopamine, along with glucose oxidase (GOx). These nanomotors facilitate the generation of hydrogen peroxide through GOx-catalyzed glucose oxidation, thereby initiating nitric oxide production from l-arginine. This dual mechanism equips MSLA@GOx-PDA with the robust motility required for deep tumor tissue penetration while depleting essential nutrients necessary for tumor growth, consequently impeding tumor progression. In addition, near-infrared lasers have the significant advantage of being depth-penetrating and non-invasive, allowing real-time fluorescence imaging and guiding dopamine-mediated mild photothermal therapy. Notably, starvation therapy depletes intracellular adenosine triphosphate and inhibits the synthesis of heat shock proteins, thus overcoming the Achilles' heel of mild photothermal therapy and significantly enhancing the efficacy of this therapy with encouraging synergistic anti-tumour effects. Overall, the integration of biochemical and optics strategies in this nanomotor platform represents a significant advancement in deep-tissue tumor therapy. It has substantial clinical translational value and is expected to have a transformative impact on future cancer treatments.

Biocatalytic cascade reactions for management of diseases

Biocatalytic cascade reactions, which evolve from the confinement of multiple enzymes within living cells, represent a promising strategy for disease management. Using tailor-made nanoplatforms, reactions induced by multiple enzymes and/or nanozymes can be precisely triggered at pathogenic sites. These promote further cascade reactions that generate therapeutic species prompting effective therapeutic outcomes with minimal side effects. Over the past few years, this approach has seen widespread applications in disease management. This review attempts to critically assess and summarize the recent advances in the use of biocatalytic cascade reactions for the management of diseases. Emphasis is placed on the design of cascade catalytic systems of high efficiency and selectivity and the implementation of specific cascade processes that respond to the endogenous substances produced in the pathological processes. The various types of biocatalytic cascade reactions are outlined according to the timeline of the catalytic steps through a series of reported examples. The challenges and outlook in the field are also discussed to encourage the further development of personalized treatments based on biocatalytic cascade reactions.

Rational Design of Nanozymes for Engineered Cascade Catalytic Cancer Therapy

Nanozymes have shown significant potential in cancer catalytic therapy by strategically catalyzing tumor-associated substances and metabolites into toxic reactive oxygen species (ROS) in situ, thereby inducing oxidative stress and promoting cancer cell death. However, within the complex tumor microenvironment (TME), the rational design of nanozymes and factors like activity, reaction substrates, and the TME itself significantly influence the efficiency of ROS generation. To address these limitations, recent research has focused on exploring the factors that affect activity and developing nanozyme-based cascade catalytic systems, which can trigger two or more cascade catalytic processes within tumors, thereby producing more therapeutic substances and achieving efficient and stable cancer therapy with minimal side effects. This area has shown remarkable progress. This Perspective provides a comprehensive overview of nanozymes, covering their classification and fundamentals. The regulation of nanozyme activity and efficient strategies of rational design are discussed in detail. Furthermore, representative paradigms for the successful construction of cascade catalytic systems for cancer treatment are summarized with a focus on revealing the underlying catalytic mechanisms. Finally, we address the current challenges and future prospects for the development of nanozyme-based cascade catalytic systems in biomedical applications.

Immobilized Multi-Enzyme/Nanozyme Biomimetic Cascade Catalysis for Biosensing Applications

Multiple enzyme-induced cascade catalysis has an indispensable role in the process of complex life activities, and is widely used to construct robust biosensors for analyzing various targets. The immobilized multi-enzyme cascade catalysis system is a novel biomimetic catalysis strategy that immobilizes various enzymes with different functions in stable carriers to simulate the synergistic catalysis of multiple enzymes in biological systems, which enables high stability of enzymes and efficiency enzymatic cascade catalysis. Nanozymes, a type of nanomaterial with intrinsic enzyme-like characteristics and excellent stabilities, are also widely applied instead of enzymes to construct immobilized cascade systems, achieving better catalytic performance and reaction stability. Due to good stability, reusability, and remarkably high efficiency, the immobilized multi-enzyme/nanozyme biomimetic cascade catalysis systems show distinct advantages in promoting signal transduction and amplification, thereby attracting vast research interest in biosensing applications. This review focuses on the research progress of the immobilized multi-enzyme/nanozyme biomimetic cascade catalysis systems in recent years. The construction approaches, factors affecting the efficiency, and applications for sensitive biosensing are discussed in detail. Further, their challenges and outlooks for future study are also provided.

Targeted Management of Diabetic Osteoporosis by Biocatalytic Cascade Reaction Nanoplatform

Diabetic osteoporosis (DOP) is a chronic complication of diabetes mellitus (DM) that impairs bone health, and effective management of DOP remains a formidable challenge. In this study, we developed a biocatalytic cascade nanoplatform, GOx@SrCaP-CAT-Tet, offering osteogenic, angiogenic, and anti-inflammatory activities for targeted DOP management. The platform includes glucose oxidase (GOx) and catalase (CAT), encapsulated in strontium-doped calcium phosphate (SrCaP), converting glucose into gluconic acid and hydrogen peroxide (H2O2), alleviating the hyperglycemia and promoting hypoxia-induced vascularization. Both the generated H2O2 and any overabundance of H2O2 in the DOP microenvironment can be scavenged by CAT, thus relieving inflammation. Via a surface modified with tetracycline (Tet) for bone targeting, the release of Sr2+, Ca2+, and PO43- can stimulate osteogenesis and suppress osteoclastogenesis, thereby hastening bone formation and reversing osteoporosis. This nanoplatform shows promise in managing DOP both in vitro and in vivo. Our findings open a new horizon for managing DOP through biocatalytic cascade reactions.

Vacancy engineering enhanced photothermal-catalytic properties of Co9S8-x nanozymes for mild NIR-II hyperthermia-amplified nanocatalytic cancer therapy

While nanozymes are commonly employed in nanocatalytic therapy (NCT), the efficacy of NCT is hampered by the limited catalytic activity of nanozymes and the intricate tumor microenvironment (TME). In this work, we design a high-efficiency nanozyme with NIR-II photothermal property for the mild hyperthermia-augmented NCT. In order to endow a single-component nanomaterial the ability to simultaneously catalyze and exhibit NIR-II photothermal properties, a straightforward template method is utilized to fabricate sulfur vacancies (VS)-doped Co9S8-x nanocages. Introducing VS not only lowers the bandgap structure of Co9S8, enhancing its NIR-II photothermal properties, but also facilitates the control of the Co2+ and Co3+ ratio in Co9S8, leading to a boost in its catalytic activity. Furthermore, the catalytic efficiency of Co9S8-x nanocages was boosted by the mild hyperthermia. Moreover, the Co9S8-x nanocages exhibited high-efficiency GSH-px-mimic catalytic activity, facilitating the cascade amplification of ROS production. Through the integrated multifunctionality of Co9S8-x nanocages, we successfully enhanced the effectiveness of antitumor treatment with a single drug injection and a single 1064 nm laser irradiation for mild hyperthermia-augmented NCT. This work provides a distinct paradigm of endowing nanomaterials with catalytic activity and photothermal property for mild NIR-II PTT-amplified NCT through a vacancy engineering strategy.

NIR-II Fluorescence/Photoacoustic Dual Ratiometric Probes with Unique Recognition Site for Quantitatively Visualizing H2S2 in Vivo

Hydrogen persulfide (H2S2) plays a significant role in redox biology and signal transduction; therefore, quantitative visualization of H2S2 in the deep tissue of living organisms is essential for obtaining reliable information about relevant pathophysiological processes directly. However, currently reported H2S2 probes are unsuitable for this purpose because of their poor selectivity for many polysulfide species or their short wavelength, which hinders precise imaging in deep tissues. Herein, for the first time, we report a unique H2S2-mediated dithiole formation reaction. Based on this reaction, we construct the first NIR-II fluorescence (FL) and photoacoustic (PA) dual-ratiometric probe (NIR-II-H2S2) for quantitatively visualizing H2S2 in vivo. This probe shows dual-ratiometric NIR-II fluorescence (I840/I1000, 107-fold) and photoacoustic (PA800/PA900, 6.5-fold) responses towards Na2S2 species with high specificity, excellent sensitivity (1.8 nM), improved water solubility, and deep-tissue penetration. More importantly, using NIR-II dual-ratiometric FL/PA imaging, we successfully demonstrated that the probe could be used to accurately quantify the fluctuating H2S2 levels in the liver-injury mouse models induced by lipopolysaccharides or metformin drugs. Overall, this study not only presents a promising tool for H2S2-related pathological research, but also provides a unique recognition site that may be generalized for designing more useful H2S2 imaging agents in the future.

Biological activation of Fenton reaction in polymeric nanoreactors driven by ferrocene-containing membranes: a microenvironment dependent study

Nanocatalytic medicine for treating cancer requires effective, versatile and novel tools and approaches to significantly improve the therapeutic efficiency for the interactions of (non-)enzymatic reactions. However, it is necessary to develop (non-)enzymatic nanotechnologies capable of selectively killing tumour cells without harming normal cells. Their therapeutic characteristics should be the adaption of tumours' extra- and intracellular environment to being specifically active. To contribute to this common goal, we propose the use of pH- and redox-responsive ferrocene containing polymersomes (FcPsomes). This allows the regulation of their biological activities for the controlled production of radicals via the Fenton reaction and the transport and release of cargo molecules via (destroying) host-guest interactions. This is provided by the Fc-membrane composition of FcPsomes showing different pH responsive active membrane, meaning the membrane permeability is triggering the Fenton reaction. The modulation of radical production is validated by various spectroscopic techniques. Moreover, these nanocontainers allow biological action of glucose oxidase (GOx) as therapeutic enzyme to produce glucono-1,5-lactone as proton source and hydrogen peroxide, initiating the Fenton reaction, in their interior. This provides a synergistic cancer therapeutic treatment for the starvation of hydrogen peroxide, but also ROS-mediated chemodynamic therapy at defined pH values. By modulating membrane permeability, we achieve environmentally regulated and locally driven therapeutic activity in the confinement of FcPsomes, ensuring specificity and safety treatments. The versatility of this platform extends beyond their specific application, allowing for their beneficial therapeutic use, for example, in signaling pathways of cells through the integration of various enzymes in FcPsomes.

Lactobacillus gasseri prevents ibrutinib-associated atrial fibrillation through butyrate

BACKGROUND

Ibrutinib, a widely used anti-cancer drug, is known to significantly increase the susceptibility to atrial fibrillation (AF). While it is recognized that drugs can reshape the gut microbiota, influencing both therapeutic effectiveness and adverse events, the role of gut microbiota in ibrutinib-induced AF remains largely unexplored.

METHOD

Utilizing 16S rRNA gene sequencing, faecal microbiota transplantation, metabonomics, electrophysiological examination, and molecular biology methodologies, we sought to validate the hypothesis that gut microbiota dysbiosis promotes ibrutinib-associated AF and to elucidate the underlying mechanisms.

RESULT

We found that ibrutinib administration pre-disposes rats to AF. Interestingly, ibrutinib-associated microbial transplantation conferred increased susceptibility to AF in rats. Notably, ibrutinib induced a significantly decrease in the abundance of Lactobacillus gasseri (L. gasseri), and oral supplementation of L. gasseri or its metabolite, butyrate (BA), effectively prevented rats from ibrutinib-induced AF. Mechanistically, BA inhibits the generation of reactive oxygen species, thereby ameliorating atrial structural remodelling. Furthermore, we demonstrated that ibrutinib inhibited the growth of L. gasseri by disrupting the intestinal barrier integrity.

CONCLUSION

Collectively, our findings provide compelling experimental evidence supporting the potential efficacy of targeting gut microbes in preventing ibrutinib-associated AF, opening new avenues for therapeutic interventions.

Dual-Ligand Assisted Anisotropic Assembly for the Construction of NIR-II Light-Propelled Mesoporous Nanomotors

The advent of autonomous nanomotors presents exciting opportunities for nanodrug delivery. However, significant potential remains for enhancing the asymmetry of nanomotors and advancing the development of second near-infrared (NIR-II) light-propelled nanomotors capable of operating within deep tissues. Herein, we developed a dual-ligand assisted anisotropic assembly strategy that enables precise regulation of the interfacial energy between selenium (Se) nanoparticle and periodic mesoporous organosilica (PMO). This strategy facilitates the controllable anisotropic growth of PMO on the Se nanoparticle, leading to the formation of Se&PMO Janus nanohybrids. The exposure ratio of the Se subunit within the Janus nanohybrids can be finely tuned from 0% to 75%. Leveraging the transformability of the Se subunit, a variety of functional MxSe&PMO Janus nanocomposites (MxSe denotes metal selenide) were further derived. As a proof of concept, CuSe&PMO Janus nanohybrids, with NIR-II photothermal properties, were employed as NIR-II light-driven nanomotors. By precisely controlling the exposure ratio of the CuSe subunit within the Janus nanostructure, these CuSe&PMO nanomotors achieved optimal self-propulsion, thus enhancing cellular uptake and promoting deep tumor penetration. Furthermore, the high loading capacity and hydrophobic framework of the PMO subunit enabled the incorporation of hydrophobic disulfiram, thereby significantly boosting the efficacy of synergistic active-motion photothermal therapy.

In Situ Fabrication of Electrospun Magnetic Film under Laparoscopic Guidance for Preventing Postoperative Recurrence of Hepatocellular Carcinoma

Despite laparoscopic-guided minimally invasive hepatectomy emerging as the primary approach for resecting hepatocellular carcinoma (HCC), there is still a significant gap in suitable biomaterials that seamlessly integrate with these techniques to achieve effective hemostasis and suppress residual tumors at the surgical margin. Electrospun films are increasingly used for wound closure, yet the employment of prefabricated electrospun films for hemostasis during minimally invasive HCC resection is hindered by prolonged operation times, complexity in implementation, limited visibility during surgery, and inadequate postoperative prevention of HCC recurrence. In this study, montmorillonite-iron oxide sheets are integrated into the polyvinylpyrrolidone (PVP) polymer framework, enhancing the resulting electrospun PVP/montmorillonite-iron oxide (MI) film (abbreviated as PMI) with robustness, hemostatic capability, and magnetocaloric properties. In contrast to the in vitro prefabricated electrospun films, the electrospun PMI film is designed to be formed in situ on liver wounds under laparoscopic guidance during hepatectomy. This design affords superior wound adaptability, facilitating meticulous wound closure and expeditious hemostasis, thereby simplifying the operative process and ultimately alleviating the workload of healthcare professionals. Moreover, when exposed to an alternating magnetic field, the film can efficiently ablate residual tumors, significantly augmenting the treatment efficacy of HCC.

Engineering Two-dimensional tungsten-doped molybdenum selenide transformed conformational nanoarchitectonics: Trimodal therapeutic nanoagents for enhanced synergistic Photothermal/Chemodynamic/Chemotherapy of breast carcinoma

Two-dimensional transition metal dichalcogenides (TMDCs) exhibit promising photothermal therapy (PTT) and chemodynamic therapy (CDT) for anti-tumour treatment. Herein, we proposed an engineering strategy to regulate the lattice structure of tungsten-doped molybdenum selenide (MoxW1-xSe2) transformed conformational nanoarchitectonics using a microwave-assisted solvothermal method for enhancing peroxidase (POD)-like catalytic performance by adjusting the ratio of molybdenum (Mo) and tungsten (W). Furthermore, the optimised Mo0.8W0.2Se2 nanoflakes surface was modified with chitosan (CHI) for improved biocompatibility and nanocatalytic efficacy, then the obtained CHI-Mo0.8W0.2Se2 subsequently loaded the chemotherapeutic drug mitoxantrone (MTO) for enhanced 4 T1 cells killing ability, shortly denoted as CHI-Mo0.8W0.2Se2-MTO for PTT-augmented CDT and chemotherapy (CT). A series of performance validations successfully showed that electrons tend to transfer from W to Mo in CHI-Mo0.8W0.2Se2, which resulted in superior POD-like activity (Km = 0.038 mM) of CHI-Mo0.8W0.2Se2 compared with that of horseradish peroxidase. Furthermore, CHI-Mo0.8W0.2Se2-MTO with excellent photothermal conversion efficiency (PCE=63.2 %) in the near-infrared (NIR) region could further promote endogenous •OH generation and MTO controlled release within solid tumours. In vivo studies confirmed the successful achievement of synergistic therapeutic effects (tumour inhibition rate of over 90 %) with minimised side effects. Versatile therapeutic nanoagents hold great potential for personalised therapy of breast cancer and will find their way to the pharmaceutical field.

Trends and developments in 3D photoacoustic imaging systems: A review of recent progress

Photoacoustic imaging (PAI) is a non-invasive diagnostic imaging technique that utilizes the photoacoustic effect by combining optical and ultrasound imaging systems. The development of PAI is mostly centered on the generation of a high-quality 3D reconstruction system for more optimal and accurate identification of tissue abnormalities. This literature study was conducted to analyze the 3D image reconstruction in PAI over 2017-2024. In this review, the collected articles in 3D photoacoustic imaging were categorized based on the approach, design, and purpose of each study. Firstly, the approaches of the studies were classified into three groups: experimental studies, numerical simulation, and numerical simulation with experimental validation. Secondly, the design of the study was assessed based on the photoacoustic modality, laser type, and sensing mechanism. Thirdly, the purpose of the collected studies was summarized into seven subsections, including image quality improvement, frame rate improvement, image segmentation, system integration, inter-systems comparisons, improving computational efficiency, and portable system development. The results of this review revealed that the 3D PAI systems have been developed by various research groups, suggesting the investigation of numerous biological objects. Therefore, 3D PAI has the potential to contribute a wide range of novel biological imaging systems that support real-time biomedical imaging in the future.

Molecular Engineering of Xanthene Dyes with 3D Multimodal-Imaging Ability to Guide Photothermal Therapy

Phototheranostics integrates light-based diagnostic techniques with therapeutic interventions, offering a non-invasive, precise, and swift approach for both disease detection and treatment. The efficacy of this approach hinges on the multimodal imaging potential and photothermal conversion efficiency (PCE) of phototheranostic agents (PTAs). Despite the promise, crafting multifunctional phototheranostic organic small molecules brims with challenges. In this research, four innovative xanthene-derived PTAs are synthesized by fine-tuning the donor-π-acceptor (D-π-A) system to strike a balance between radiative and nonradiative decay. The inherent robust photostability and intense fluorescence of the traditional xanthene core are preserved, meanwhile the addition of highly electron-withdrawing groups boosts the non-radiative decay rate to enhance PCE and photoacoustic imaging capabilities. Remarkably, one of the PTAs, DMBA, demonstrates an exceptional absolute fluorescence quantum yield of 2.46% in PBS, and when encapsulated into nanoparticles, it achieves a high PCE of 79.5%. Consequently, DMBA nanoparticles (DMBA-NPs) are effectively employed in fluorescence, 3D photoacoustic, and photothermal imaging-guiding tumor photothermal therapy. This represents the first instance of a multimodal phototheranostic xanthene agent achieving synergistic fluorescence and photoacoustic imaging for diagnostic purposes. Furthermore, this work paves the way for leveraging xanthene fluorophores as versatile tools in the development of multifunctional reagents.

A pH-Sensitive Glucose Oxidase and Hemin Coordination Micelle for Multi-Enzyme Cascade and Amplified Cancer Chemodynamic Therapy

Chemodynamic therapy (CDT) is an emerging therapeutic paradigm for cancer treatment that utilizes reactive oxygen species (ROS) to induce apoptosis of cancer cells but few biomaterials have been developed to differentiate the cancer cells and normal cells to achieve precise and targeted CDT. Herein, a simple cascade enzyme system is developed, termed hemin-micelles-GOx, based on hemin and glucose oxidase (GOx)-encapsulated Pluronic F127 (F127) micelles with pH-sensitive enzymatic activities. Histidine-tagged GOx can be easily chelated to hemin-F127 micelles via the coordination of histidine and ferrous ions in the center of hemin by simple admixture in an aqueous solution. In tumor microenvironment (TME), hemin-micelles-GOx exhibits enhanced peroxidase (POD)-like activities to generate toxic hydroxyl radicals due to the acidic condition, whereas in normal cells the catalase (CAT)-like, but not POD-like activity is amplified, resulting in the elimination of hydrogen peroxide to generate oxygen. In a murine melanoma model, hemin-micelles-GOx significantly suppresses tumor growth, demonstrating its great potential as a pH-mediated enzymatic switch for tumor management by CDT.

Water-dispersible fluorescent COFs disturb lysosomal autophagy to boost cascading enzymatic chemodynamic-starvation therapy

Cascading enzymatic therapy is a promising approach in cancer treatment. However, its effectiveness is often hindered by enzyme inactivation, limited exposure of active sites, cancer cell self-protection mechanisms such as autophagy, and non-specific toxicity, which can lead to treatment failure. To address these challenges, we used a low-temperature aqueous-phase synthesis method to create semi-crystalline, water-dispersible fluorescent COF nanospheres. These nanospheres can stably load glucose oxidase (GOx) and ultrafine Fe2O3 nanozymes, allowing for convenient coating with tumor cell membranes to form a uniform tumor-targeted cascading enzymatic nanosystem (CFGM). This system promotes a cycle of tumor glucose depletion, reactive oxygen species (ROS) generation, and oxygen production, facilitating tumor-targeted starvation therapy (ST) and chemodynamic therapy (CDT). Notably, the semi-crystalline COF carrier within this system can degrade slowly under mildly acidic conditions, forming large aggregates that damage lysosomes and disrupt lysosomal autophagy, thereby eliminating the autophagy protection of cancer cells activated by the combined ST. This synergistic approach enhances the catalytic inhibition of tumors. Our research thus provides an alternative COF-based platform and strategy for effective cancer treatment.

Dual Enzyme-Driven Cascade Reactions Modulate Immunosuppressive Tumor Microenvironment for Catalytic Therapy and Immune Activation

Lactate-enriched tumor microenvironment (TME) fosters an immunosuppressive milieu to hamper the functionality of tumor-associated macrophages (TAMs). However, tackling the immunosuppressive effects wrought by lactate accumulation is still a big challenge. Herein, we construct a dual enzyme-driven cascade reaction platform (ILH) with immunosuppressive TME modulation for photoacoustic (PA) imaging-guided catalytic therapy and immune activation. The ILH is composed of iridium (Ir) metallene nanozyme, lactate oxidase (LOx), and hyaluronic acid (HA). The combination of Ir nanozyme and LOx can not only efficiently consume lactate to reverse the immunosuppressive TME into an immunoreactive one by promoting the polarization of TAMs from the M2 to M1 phenotype, thus enhancing antitumor defense, but also alleviate tumor hypoxia as well as induce strong oxidative stress, thus triggering immunogenic cell death (ICD) and activating antitumor immunity. Furthermore, the photothermal performance of Ir nanozyme can strengthen the cascade catalytic ability and endow ILH with a PA response. Based on the changes in PA signals from endogenous molecules, three-dimensional multispectral PA imaging was utilized to track the process of cascade catalytic therapy in vivo. This work provides a nanoplatform for dual enzyme-driven cascade catalytic therapy and immune activation by regulating the immunosuppressive TME.

A Self-Cascade Oxygen-Generating Nanomedicine for Multimodal Tumor Therapy

Natural and artificial enzyme oxygen-generating systems for photodynamic therapy (PDT) are developed for tumor treatment, yet they have fallen short of the desired efficacy. Moreover, both the enzymes and photosensitizers usually need carriers for efficient delivery to tumor sites. Here, a self-cascade-enhanced multimodal tumor therapy is developed by ingeniously integrating self-cascade-enhanced PDT with Zn2+-overloading therapy. Manganese-porphyrin (TCPP-Mn) is chosen both as the photosensitizer and catalase (CAT) mimic, which can be encapsulated within glucose oxidase (GOx). Acid-responsive zeolitic imidazolate framework-8 (ZIF-8) is applied as the carrier for TCPP-Mn@GOx (T@G), attaining TCPP-Mn@GOx@ZIF-8 (T@G@Z). T@G@Z demonstrates robust anti-tumor ability as follows: upon the structural degradation of ZIF-8, GOx can mediate the oxidation of glucose and generate hydrogen peroxide (H2O2); TCPP-Mn can catalyze H2O2 into O2 for self-cascade-enhanced PDT; meanwhile, the released Zn2+ can enhance oxidative stress and induce mitochondrial dysfunction by destroying mitochondrial membrane potential; furthermore, immunotherapy can be activated to resist primary tumor and tumor metastasis. The self-cascade-enhanced T@G@Z exhibited its potential application for further tumor management.

Inducing disulfidptosis in tumors:potential pathways and significance

Regulated cell death (RCD) is crucial for the elimination of abnormal cells. In recent years, strategies aimed at inducing RCD, particularly apoptosis, have become increasingly important in cancer therapy. However, the ability of tumor cells to evade apoptosis has led to treatment resistance and relapse, prompting extensive research into alternative death processes in cancer cells. A recent study identified a novel form of RCD known as disulfidptosis, which is linked to disulfide stress. Cancer cells import cystine from the extracellular environment via solute carrier family 7 member 11 (SLC7A11) and convert it to cysteine using nicotinamide adenine dinucleotide phosphate (NADPH). When NADPH is deficient or its utilization is impaired, cystine accumulates, leading to the formation of disulfide bonds in the actin cytoskeleton, triggering disulfidptosis. Disulfidptosis reveals a metabolic vulnerability in tumors, offering new insights into cancer therapy strategies. This review provides a detailed overview of the mechanisms underlying disulfidptosis, the current research progress, and limitations. It also highlights innovative strategies for inducing disulfidptosis and explores the potential of combining these approaches with traditional cancer therapies, particularly immunotherapy, to expedite clinical translation.

Innovative lipid nanoparticles: A cutting-edge approach for potential renal cell carcinoma therapeutics

The kidney plays a crucial role in regulating homeostasis within the human body. Renal cell carcinoma (RCC) is the most common form of kidney cancer, accounting for nearly 90 % of all renal malignancies. Despite the availability of various therapeutic strategies, RCC remains a challenging disease due to its resistance to conventional treatments. Nanotechnology has emerged as a promising field, offering new opportunities in cancer therapeutics. It presents several advantages over traditional methods, enabling diverse biomedical applications, including drug delivery, prevention, diagnosis, and treatment. Lipid nanoparticles (LNPs), approximately 100 nm in size, are derived from a range of lipids and other biochemical compounds. these particulates are designed to overcome biological barriers, allowing them to selectively accumulate at diseased target sites for effective therapeutic action. Many pharmaceutically important compounds face challenges such as poor solubility in aqueous solutions, chemical and physiological instability, or toxicity. LNP technology stands out as a promising drug delivery system for bioactive organic compounds. This article reviews the applications of LNPs in RCC treatment and explores their potential clinical translation, identifying the most viable LNPs for medical use. With ongoing advancement in LNP-based anticancer strategies, there is a growing potential to improve the management and treatment of renal cancer.

Regenerating Chemotherapeutics through Copper-Based Nanomedicine: Disrupting Protein Homeostasis for Enhanced Tumor Therapy

The bis-(diethyldithiocarbamate)-copper (CuET), the disulfiram (DSF)-Cu complex, has exhibited noteworthy anti-tumor property. However, its efficacy is compromised due to the inadequate oxidative conditions and the limitation of bioavailable copper. Because CuET can inactivate valosin-containing protein (VCP), a bioinformatic pan-cancer analysis of VCP is first conducted in this study to identify CuET as a promising anticancer drug for diverse cancer types. Then, based on the drug action mechanism, a nanocomposite of CuET and copper oxide (CuO) is designed and fabricated utilizing bovine serum albumin (BSA) as the template (denoted as CuET-CuO@BSA, CCB). CCB manifests peroxidase (POD)-mimicking activity to oxidize the tumor endogenous H2O2 to generate reactive oxygen species (ROS), enhancing the chemotherapy effect of CuET. Furthermore, the cupric ions released after enzymatic reaction can regenerate CuET, which markedly perturbs intracellular protein homeostasis and induces apoptosis of tumor cells. Meanwhile, CCB triggers cuproptosis by inducing the aggregation of lipoylated proteins. The multifaceted action of CCB effectively inhibits tumor progression. Therefore, this study presents an innovative CuET therapeutic strategy that creates an oxidative microenvironment in situ and simultaneously self-supply copper source for CuET regeneration through the combination of CuO nanozyme with CuET, which holds promise for application of CuET for effective tumor therapy.

Biodegradable iridium coordinated nanodrugs potentiate photodynamic therapy and immunotherapy of lung cancer

Hypoxia, which is a common characteristic of most solid tumors, not only contributes to the immunosuppressive nature of the tumor microenvironment (TME) but also reduces the efficacy of many oxygen-depleting therapies, including photodynamic therapy (PDT). In this study, we developed acidity-responsive biodegradable iridium-coordinated (IPC) nanodrugs consisting of iridium ions, the photosensitizer chlorin e6 (Ce6), and polyvinylpyrrolidone to potentiate the effects of PDT and immunotherapy by modulating the TME. IPC nanodrugs that accumulate at high levels in tumors catalyze excess hydrogen peroxide to produce oxygen while depleting glutathione levels within cancer cells; thus, the released Ce6 is more efficient at producing reactive oxygen species (ROS) in response to laser irradiation. In addition, IPC nanodrugs alleviate tumor hypoxia, induce more immunogenic cell death by amplifying PDT responses, and synergistically inhibit tumor growth by initiating robust antitumor immunity and reversing the immunosuppressive nature of the TME. As a result, IPC nanodrugs exert pronounced combined therapeutic effects in vitro and in vivo, without obvious toxic effects due to acidity-responsive degradation. These iridium-coordinated nanodrugs have the potential to modulate the TME, amplify the effects of PDT, and substantially inhibit tumors, and they are expected to provide novel ideas for combination therapy of hypoxic cancer.

Promoting chondrogenesis by targeted delivery to the degenerating cartilage in early treatment of osteoarthritis

Osteoarthritis (OA) is a highly incident total joint degenerative disease with cartilage degeneration as the primary pathogenesis. The cartilage matrix is mainly composed of collagen, a matrix protein with a hallmark triple-helix structure, which unfolds with collagen degradation on the cartilage surface. A collagen hybridizing peptide (CHP) is a synthetic peptide that binds the denatured collagen triple helix, conferring a potential disease-targeting possibility for early-stage OA. Here, we constructed an albumin nanoparticle (An) conjugated with CHP, loaded with a chondrogenesis-promoting small molecule drug, kartogenin (KGN). The CHP-KGN-An particle exhibited sustained release of KGN in vitro and prolonged in vivo retention selectively within the degenerated cartilage in the knee joints of model mice with early-stage OA. Compared to treatment with KGN alone, CHP-KGN-An robustly attenuated cartilage degradation, synovitis, osteophyte formation, and subchondral bone sclerosis in OA model mice and exhibited a more prominent effect on physical activity improvement and pain alleviation. Our study showcases that targeting the degenerated cartilage by collagen hybridization can remarkably promote the efficacy of small molecule drugs and may provide a novel delivery strategy for early-stage OA therapeutics.

Nanozymes-Mediated Cascade Reaction System for Tumor-Specific Diagnosis and Targeted Therapy

Cascade reactions are described as efficient and versatile tools, and organized catalytic cascades can significantly improve the efficiency of chemical interworking between nanozymes. They have attracted great interest in many fields such as chromogenic detection, biosensing, tumor diagnosis, and therapy. However, how to selectively kill tumor cells by enzymatic reactions without harming normal cells, as well as exploring two or more enzyme-engineered nanoreactors for cascading catalytic reactions, remain great challenges in the field of targeted and specific cancer diagnostics and therapy. The latest research advances in nanozyme-catalyzed cascade processes for cancer diagnosis and therapy are described in this article. Here, various sensing strategies are summarized, for tumor-specific diagnostics. Targeting mechanisms for tumor treatment using cascade nanozymes are classified and analyzed, "elements" and "dimensions" of cascade nanozymes, types, designs of structure, and assembly modes of highly active and specific cascade nanozymes, as well as a variety of new strategies of tumor targeting based on the cascade reaction of nanozymes. Finally, the integrated application of the cascade nanozymes systems in tumor-targeted and specific diagnostic therapy is summarized, which will lay the foundation for the design of more rational, efficient, and specific tumor diagnostic and therapeutic modalities in the future.

Persistent Luminescence-Based Nanoreservoir for Benign Photothermal-Reinforced Nanozymatic Therapy

Adjusting the catalytic activity of nanozymes for enhanced oncotherapy has attracted significant interest. However, it remains challenging to engineer regulatory tactics with a minimal impact on normal tissues. By exploiting the advantages of energy storage, photostimulated, and long afterglow luminescence of persistent nanoparticles (PLNPs), a persistent luminescence-based nanoreservoir was produced to improve its catalytic activity for benign oncotherapy. In the study, PLNPs in a nanoreservoir with the ability to store photons served as a self-illuminant to promote its peroxidase-like activity and therapeutic efficacy by persistently motivating its photothermal effect before and after external irradiation ceased. The photostimulated and persistent luminescence of PLNPs and spatiotemporal controllability of exogenous light jointly alleviated adverse effects induced by prolonged irradiation and elevated the catalytic capability of the nanoreservoir. Ultimately, the system fulfilled benign photothermal-intensive nanozymatic therapy. This work provides new insights into boosting the catalytic activity of nanozymes for secure disease treatment.

A Multifunctional Nanoreactor-Induced Dual Inhibition of HSP70 Strategy for Enhancing Mild Photothermal/Chemodynamic Synergistic Tumor Therapy

Mild photothermal therapy (PTT) is a spatiotemporally controllable method that utilizes the photothermal effect at relatively low temperatures (40-45 °C) to especially eliminate tumor tissues with negligible side effects on the surrounding normal tissues. However, the overexpression of heat shock protein 70 (HSP70) and limited effect of single treatment drastically impede the therapeutic efficacy. Herein, the constructed multifunctional core-shell structured Ag-Cu@SiO2-PDA/GOx nanoreactors (APG NRs) that provide a dual inhibition of HSP70 strategy for the second near-infrared photoacoustic (NIR-II PA) imaging-guided combined mild PTT/chemodynamic therapy (CDT). The Ag-Cu cores can convert endogenous H2O2 to hydroxyl radical (•OH), which can induce lipid peroxidation (LPO) and further degrade HSP70. The polydopamine (PDA)/glucose oxidase (GOx) shells are utilized as the NIR-II photothermal agent to generate low temperature, and the GOx can reduce the energy supplies and inhibit energy-dependent HSP70 expression. Furthermore, both the generation of •OH and GOx-mediated energy shortage can reduce HSP70 expression to sensitize mild PTT under 1064 nm laser, and in turn, GOx and laser self-amplify the catalytic reactions of APG NRs for more production of •OH. The multifunctional nanoreactors will provide more potential possibilities for the clinical employment of mild PTT and the advancement of tumor combination therapies.

Semiconducting Polymer Dots for Dual-Wavelength Differential Background-Suppressed Photoacoustic Imaging

Photoacoustic imaging (PAI) can sensitively detect regions and substances with strong optical absorption, which means that diseased tissue can be imaged with high contrast in the presence of surrounding healthy tissue through the photoacoustic effect. However, its signal intensity and resolution may be limited by background signals generated by endogenous chromophores such as melanin and hemoglobin. A feasible method for practical application of this so-called background-suppressed PAI is still lacking. In this work, a dual-wavelength differential background noise-suppressed photoacoustic tomography is developed based on organic semiconducting polymer dots (Pdots). The Pdots have a strong absorption peak at 945 nm, and then the absorption decreases sharply with the increase of wavelength, and the absorption intensity drops to only about a quarter of the original value at 1050 nm. The present system significantly suppresses the strong background noise of blood through dual-wavelength differential PAI, enabling precise monitoring of the distribution information of theranostic agents in diseased tissues. The signal-to-noise ratio of the theranostic agent distribution map is increased by about 20 dB. This work provides a platform for real-time and accurate monitoring of tumors and drugs, which helps avoid damage to healthy tissue during treatment and has clinical significance in cancer treatment.

Catalytic Nanoparticles in Biomedical Applications: Exploiting Advanced Nanozymes for Therapeutics and Diagnostics

Catalytic nanoparticles (CNPs) as heterogeneous catalyst reveals superior activity due to their physio-chemical features, such as high surface-to-volume ratio and unique optical, electric, and magnetic properties. The CNPs, based on their physio-chemical nature, can either increase the reactive oxygen species (ROS) level for tumor and antibacterial therapy or eliminate the ROS for cytoprotection, anti-inflammation, and anti-aging. In addition, the catalytic activity of nanozymes can specifically trigger a specific reaction accompanied by the optical feature change, presenting the feasibility of biosensor and bioimaging applications. Undoubtedly, CNPs play a pivotal role in pushing the evolution of technologies in medical and clinical fields, and advanced strategies and nanomaterials rely on the input of chemical experts to develop. Herein, a systematic and comprehensive review of the challenges and recent development of CNPs for biomedical applications is presented from the viewpoint of advanced nanomaterial with unique catalytic activity and additional functions. Furthermore, the biosafety issue of applying biodegradable and non-biodegradable nanozymes and future perspectives are critically discussed to guide a promising direction in developing span-new nanozymes and more intelligent strategies for overcoming the current clinical limitations.

Reversibly photoswitchable protein assemblies with collagen affinity for in vivo photoacoustic imaging of tumors

Recent advancements in photoacoustic (PA) imaging have leveraged reversibly photoswitchable chromophores, known for their dual absorbance states, to enhance imaging sensitivity through differential techniques. Yet, their deployment in tumor imaging has faced obstacles in achieving targeted delivery with high efficiency and specificity. Addressing this challenge, we introduce innovative protein assemblies, DrBphP-CBD, by genetically fusing a photosensory module from Deinococcus radiodurans bacterial phytochrome (DrBphP) with a collagen-binding domain (CBD). These protein assemblies form sub-100-nanometer structures composed of 24 DrBphP dimers and 12 CBD trimers, presenting 24 protein subunits. Their affinity for collagens, combined with impressive photoswitching contrast, markedly improves PA imaging precision. In various tumor models, intravenous administration of DrBphP-CBD has demonstrated enhanced tumor targeting and retention, augmenting contrast in PA imaging by minimizing background noise. This strategy underscores the clinical potential of DrBphP-CBD as PA contrast agents, propelling photoswitchable chromoproteins to the forefront of precise cancer diagnosis.

Nanoparticle-mediated cell pyroptosis: a new therapeutic strategy for inflammatory diseases and cancer

Pyroptosis, a lytic form of cell death mediated by the gasdermin family, is characterized by cell swelling and membrane rupture. Inducing pyroptosis in cancer cells can enhance antitumor immune responses and is a promising strategy for cancer therapy. However, excessive pyroptosis may trigger the development of inflammatory diseases due to immoderate and continuous inflammatory reactions. Nanomaterials and nanobiotechnology, renowned for their unique advantages and diverse structures, have garnered increasing attention owing to their potential to induce pyroptosis in diseases such as cancer. A nano-delivery system for drug-induced pyroptosis in cancer cells can overcome the limitations of small molecules. Furthermore, nanomedicines can directly induce and manipulate pyroptosis. This review summarizes and discusses the latest advancements in nanoparticle-based treatments with pyroptosis among inflammatory diseases and cancer, focusing on their functions and mechanisms and providing valuable insights into selecting nanodrugs for pyroptosis. However, the clinical application of these strategies still faces challenges owing to a limited understanding of nanobiological interactions. Finally, future perspectives on the emerging field of pyroptotic nanomaterials are presented.

Opportunities for nanomaterials in enzyme therapy

In recent years, enzyme therapy strategies have rapidly evolved to catalyze essential biochemical reactions with therapeutic potential. These approaches hold particular promise in addressing rare genetic disorders, cancer treatment, neurodegenerative conditions, wound healing, inflammation management, and infectious disease control, among others. There are several primary reasons for the utilization of enzymes as therapeutics: their substrate specificity, their biological compatibility, and their ability to generate a high number of product molecules per enzyme unit. These features have encouraged their application in enzyme replacement therapy where the enzyme serves as the therapeutic agent to rectify abnormal metabolic and physiological processes, enzyme prodrug therapy where the enzyme initiates a clinical effect by activating prodrugs, and enzyme dynamic or starving therapy where the enzyme acts upon host substrate molecules. Currently, there are >20 commercialized products based on therapeutic enzymes, but approval rates are considerably lower than other biologicals. This has stimulated nanobiotechnology in the last years to develop nanoparticle-based solutions that integrate therapeutic enzymes. This approach aims to enhance stability, prevent rapid clearance, reduce immunogenicity, and even enable spatio-temporal activation of the therapeutic catalyst. This comprehensive review delves into emerging trends in the application of therapeutic enzymes, with a particular emphasis on the synergistic opportunities presented by incorporating enzymes into nanomaterials. Such integration holds the promise of enhancing existing therapies or even paving the way for innovative nanotherapeutic approaches.

Erythrocyte Membrane Camouflaged Nanotheranostics for Optical Molecular Imaging-Escorted Self-Oxygenation Photodynamic Therapy

Hypoxic tumor microenvironment (TME) hampers the application of oxygen (O2)-dependent photodynamic therapy (PDT) in solid tumors. To address this problem, a biomimetic nanotheranostics (named MMCC@EM) is developed for optical molecular imaging-escorted self-oxygenation PDT. MMCC@EM is synthesized by encapsulating chlorin e6 (Ce6) and catalase (CAT) in metal-organic framework (MOF) nanoparticles with erythrocyte membrane (EM) camouflage. Based on the biomimetic properties of EM, MMCC@EM efficiently accumulates in tumor tissues. The enriched MMCC@EM achieves TME-activatable drug release, thereby releasing CAT and Ce6, and this process can be monitored through fluorescence (FL) imaging. In addition, endogenous hydrogen peroxide (H2O2) will be decomposed by CAT to produce O2, which can be reflected by the measurement of intratumoral oxygen concentration using photoacoustic (PA) imaging. Such self-oxygenation nanotheranostics effectively mitigate tumor hypoxia and improve the generation of singlet oxygen (1O2). The 1O2 disrupts mitochondrial function and triggers caspase-3-mediated cellular apoptosis. Furthermore, MMCC@EM triggers immunogenic cell death (ICD) effect, leading to an increased infiltration of cytotoxic T lymphocytes (CTLs) into tumor tissues. As a result, MMCC@EM exhibits good therapeutic effects in 4T1-tumor bearing mice under the navigation of FL/PA duplex imaging.

Confined semiconducting polymers with boosted NIR light-triggered H2O2 production for hypoxia-tolerant persistent photodynamic therapy

Hypoxia featured in malignant tumors and the short lifespan of photo-induced reactive oxygen species (ROS) are two major issues that limit the efficiency of photodynamic therapy (PDT) in oncotherapy. Developing efficient type-I photosensitizers with long-term ˙OH generation ability provides a possible solution. Herein, a semiconducting polymer-based photosensitizer PCPDTBT was found to generate 1O2, ˙OH, and H2O2 through type-I/II PDT paths. After encapsulation within a mesoporous silica matrix, the NIR-II fluorescence and ROS generation are enhanced by 3-4 times compared with the traditional phase transfer method, which can be attributed to the excited-state lifetime being prolonged by one order of magnitude, resulting from restricted nonradiative decay channels, as confirmed by femtosecond spectroscopy. Notably, H2O2 production reaches 15.8 μM min-1 under a 730 nm laser (80 mW cm-2). Further adsorption of Fe2+ ions on mesoporous silica not only improves the loading capacity of the chemotherapy drug doxorubicin but also triggers a Fenton reaction with photo-generated H2O2 in situ to produce ˙OH continuously after the termination of laser irradiation. Thus, semiconducting polymer-based nanocomposites enables NIR-II fluorescence imaging guided persistent PDT under hypoxic conditions. This work provides a promising paradigm to fabricate persistent photodynamic therapy platforms for hypoxia-tolerant phototheranostics.

Noninvasive Photothermal Therapy of Nasopharyngeal Cancer Guided by High Efficiency Optical-Absorption Nanomaterial Enhanced by NIR-II Photoacoustic Imaging

Background

Photothermal therapy (PTT) guided by photoacoustic imaging (PAI) using nanoplatforms has emerged as a promising strategy for cancer treatment due to its efficiency and accuracy. This study aimed to develop and synthesize novel second near-infrared region (NIR-II) absorption-conjugated polymer acceptor acrylate-substituted thiadiazoloquinoxaline-diketopyrrolopyrrole polymers (PATQ-DPP) designed specifically as photothermal and imaging contrast agents for nasopharyngeal carcinoma (NPC).

Methods

The PATQ-DPP nanoparticles were synthesized and characterized for their optical properties, including low optical band gaps. Their potential as PTT agents and imaging contrast agents for NPC was evaluated both in vitro and in vivo. The accumulation of nanoparticles at tumor sites was assessed post-injection, and the efficacy of PTT under near-infrared laser irradiation was investigated in a mouse model of NPC.

Results

Experimental results indicated that the PATQ-DPP nanoparticles exhibited significant photoacoustic contrast enhancement and favorable PTT performance. Safety and non-toxicity evaluations confirmed the biocompatibility of these nanoparticles. In vivo studies showed that PATQ-DPP nanoparticles effectively accumulated at NPC tumor sites and demonstrated excellent tumor growth inhibition upon exposure to near-infrared laser irradiation. Notably, complete elimination of nasopharyngeal tumors was observed within 18 days following PTT.

Discussion

The findings suggest that PATQ-DPP nanoparticles are a promising theranostic agent for NIR-II PAI and PTT of tumors. This innovative approach utilizing PATQ-DPP nanoparticles provides a powerful tool for the early diagnosis and precise treatment of NPC, offering a new avenue in the management of this challenging malignancy.

Biosynthesis of NIR-II Ag2Se Quantum Dots with Bacterial Catalase for Photoacoustic Imaging and Alleviating-Hypoxia Photothermal Therapy

Developing the second near-infrared (NIR-II) photoacoustic (PA) agent is of great interest in bioimaging. Ag2Se quantum dots (QDs) are one kind of potential probe for applications in NIR-II photoacoustic imaging (PAI). However, the surfaces with excess anions of Ag2Se QDs, which increase the probability of nonradiative transitions of excitons benefiting PA imaging, are not conducive to binding electron donor ligands for potential biolabeling and imaging. In this study, Staphylococcus aureus (S. aureus) cells are driven for the biosynthesis of Ag2Se QDs with catalase (CAT). Biosynthesized Ag2Se (bio-Ag2Se-CAT) QDs are produced in Se-enriched environment of S. aureus and have a high Se-rich surface. The photothermal conversion efficiency of bio-Ag2Se-CAT QDs at 808 and 1064 nm is calculated as 75.3% and 51.7%, respectively. Additionally, the PA signal responsiveness of bio-Ag2Se-CAT QDs is ≈10 times that of the commercial PA contrast agent indocyanine green. In particular, the bacterial CAT is naturally attached to bio-Ag2Se-CAT QDs surface, which can effectively relieve tumor hypoxia. The bio-Ag2Se-CAT QDs can relieve heat-initiated oxidative stress while undergoing effective photothermal therapy (PTT). Such biosynthesis method of NIR-II bio-Ag2Se-CAT QDs opens a new avenue for developing multifunctional nanomaterials, showing great promise for PAI, hypoxia alleviation, and PTT.

Tensile Strain-Mediated Bimetallene Nanozyme for Enhanced Photothermal Tumor Catalytic Therapy

Nanozymes have demonstrated significant potential in combating malignant tumor proliferation through catalytic therapy. However, the therapeutic effect is often limited by insufficient catalytic performance. In this study, we propose the utilization of strain engineering in metallenes to fully expose the active regions due to their ultrathin nature. Here, we present the first report on a novel tensile strain-mediated local amorphous RhRu (la-RhRu) bimetallene with exceptional intrinsic photothermal effect and photo-enhanced multiple enzyme-like activities. Through geometric phase analysis, electron diffraction profile, and X-ray diffraction, it is revealed that crystalline-amorphous heterophase boundaries can generate approximately 2 % tensile strain in the bimetallene. The ultrathin structure and in-plane strain of the bimetallene induce an amplified strain effect. Both experimental and theoretical evidence support the notion that tensile strain promotes multiple enzyme-like activities. Functioning as a tumor microenvironment (TME)-responsive nanozyme, la-RhRu exhibits remarkable therapeutic efficacy both in vitro and in vivo. This work highlights the tremendous potential of atomic-scale tensile strain engineering strategy in enhancing tumor catalytic therapy.

Dual Enzyme-Encapsulated Materials for Biological Cascade Chemistry and Synergistic Tumor Starvation

Framework and polymeric nanoreactors (NRs) have distinct advantages in improving chemical reaction efficiency in the tumor microenvironment (TME). Nanoreactor-loaded oxidoreductase enzyme is activated by tumor acidity to produce H2O2 by increasing tumor oxidative stress. High levels of H2O2 induce self-destruction of the vesicles by releasing quinone methide to deplete glutathione and suppress the antioxidant potential of cancer cells. Therefore, the synergistic effect of the enzyme-loaded nanoreactors results in efficient tumor ablation via suppressing cancer-cell metabolism. The main driving force would be to take advantage of the distinct metabolic properties of cancer cells along with the high peroxidase-like activity of metalloenzyme/metalloprotein. A cascade strategy of dual enzymes such as glucose oxidase (GOx) and nitroreductase (NTR) wherein the former acts as an O2-consuming agent such as overexpression of NTR and further amplified NTR-catalyzed release for antitumor therapy. The design of cascade bioreductive hypoxia-responsive drug delivery via GOx regulates NTR upregulation and NTR-responsive nanoparticles. Herein, we discuss tumor hypoxia, reactive oxygen species (ROS) formation, and the effectiveness of these therapies. Nanoclusters in cascaded enzymes along with chemo-radiotherapy with synergistic therapy are illustrated. Finally, we outline the role of the nanoreactor strategy of cascading enzymes along with self-synergistic tumor therapy.

Saliency enhancement method for photoacoustic molecular imaging based on Grüneisen relaxation nonlinear effect

Photoacoustic molecular imaging technology has a wide range of applications in biomedical research. In practical scenarios, both the probes and blood generate signals, resulting in the saliency of the probes in the blood environment being diminished, impacting imaging quality. Although several methods have been proposed for saliency enhancement, they inevitably suffer from moderate generality and detection speed. The Grüneisen relaxation (GR) nonlinear effect offers an alternative for enhancing saliency and can improve generality and speed. In this article, the excitation and detection efficiencies are optimized to enhance the GR signal amplitude. Experimental studies show that the saliency of the probe is enhanced. Moreover, the issue of signal aliasing is studied to ensure the accuracy of enhancement results in the tissues. In a word, the feasibility of the GR-based imaging method in saliency enhancement is successfully demonstrated in the study, showing the superiorities of good generality and detection speed.