Nanoparticles with ultrasound-induced afterglow luminescence for tumour-specific theranostics

A dark-state-dominated photochemical upconversion afterglow via triplet energy transfer relay

Photochemical afterglow materials have drawn considerable attention due to their attractive luminescent properties and great application potential. Considering the classical photochemical afterglow materials always exhibit poor luminescence, it is urgent to gain fundamental understanding of the main limiting factors. Here, we identified the existence of a dark-state triplet in the photochemical process, and an overwhelming percentage of ~98.5% was revealed for this non-emissive triplet state. Guided by these observations, we proposed to activate an unprecedented triplet energy transfer relay to simultaneously harness the singlet and triplet energy. Consequently, an upconverted afterglow material was constructed with amazing luminescence performance albeit its moderate fluorescence emission property. The generality of this strategy was evidenced by the adaptation to similar emitters with varied emission wavelengths. The optimized afterglow performance enabled time-gated upconversion bioimaging under ultralow-power excitation. This study not only reveals the energy transfer pathways for photochemical afterglow but also paves the way for rational design of bright upconverted materials with ultralong lifetime.

Selective Lower-Occupied Through-Bond Interactions for Efficient Organic Phosphorescence Enabling High-Resolution Long-Wavelength Afterglow

Persistent organic room-temperature phosphorescence (RTP) enables high-resolution afterglow bioimaging, independent of autofluorescence. However, the yield of organic RTP in the long-wavelength region is generally low, which limits the high-resolution information that can be obtained from the long-wavelength region. Moreover, this makes it impossible to obtain multicolor and high-resolution afterglow images. This report describes a molecule containing no atoms from the fourth or higher period that exhibits efficient red RTP in high yield. A molecule with red phosphorescent chromophores substituted with multiple phenylthio groups reached an RTP yield of 46.3% and an RTP lifetime of 0.43 s in an appropriate crystalline host medium. The selective lower-occupied through-bond or through-space interactions among molecules significantly enhance the phosphorescence in the long-wavelength region. The highly efficient and bright red persistent RTP induces a red afterglow from individual nanoparticles. Tuning the selective lower-occupied through-bond or through-space interactions allows for the design of high-performance RTP dyes and offers a novel approach to explore high-resolution full-color afterglow imaging.

A Nanotherapeutic Agent for Synergistic Tumor Therapy: Co-Activation of Photochemical-Biological Effects

Single-mode photodynamic therapy (PDT) based on photochemical reactions is limited by the tumor microenvironment, which reduces the ablation efficiency for solid tumors. Making it vital to seek ways to improve the tumor therapeutic effect. Based on this, we propose a dual-mode intelligent nanotherapeutic system (HAP@BMPns) based on photochemical-biological effects. HAP@BMPns is composed of an acid-responsive high-calcium biomimetic nanomaterial (HAP) and photosensitizer (BMP), which can spontaneously activate photochemical (Type-I PDT) and biological effects for synergistic cancer therapy. HAP@BMPns breaks down upon entering tumor cells under acidic conditions, releasing a large amount of Ca2+ and BMP. Triggering intracellular Ca2+ overload, which induces mitochondrial damage, leading to apoptosis. Synchronously, Type-I PDT of BMP under two-photon (800 nm) laser irradiation becomes activated, resulting in enhanced destruction of tumor cells by the photochemical effect. Cell studies have indicated that HAP@BMPns (41.6 μg/mL) exhibits a strong inhibitory efficiency on tumor cells growth, with low (22.4 %) survival rate. However, the individual components, i. e. BMP (5.0 μM) and HAP (41.6 μg/mL) display low inhibitory efficiency with high survival rates (55.9 % and 63.0 % respectively). Therefore, this dual-mode synergistic treatment strategy using acid-triggered photochemical-biological effects significantly enhances the ablation of solid tumors, realizing the synergistic effect. We hope that this design strategy can provide guidance for the design and development of a tumor therapeutic platform.

Cyclometalated Iridium(III) Schiff Base Complexes for Chemiluminogenic Bioprobes

Chemiluminogenic bioimaging has emerged as a promising paradigm due to its independence from light excitation, thereby circumventing challenges related to light penetration depth and background autofluorescence. However, the availability of effective chemiluminophores remains limited, which substantially impedes their bio-applications. Herein, we discovered for the first time that cyclometalated iridium(III) Schiff base complexes can unexpectedly generate chemiluminescence. Notably, the chemiluminescence reaction was rapid, with a half-life of only 0.86 s, significantly faster than previously reported examples. Unlike conventional chemiluminescent scaffolds, the distinguishing feature of the chemiluminogenic iridium(III) complex is its unique intramolecular imine-to-amide conversion upon reaction with reactive oxygen species (ROS). Intriguingly, the chemiluminogenicity of these complexes is not influenced by the cyclometalating ligands but is closely associated with the Schiff base ligand, allowing for tuning of the emission colors via altering the cyclometalating ligands. Additionally, we formulated one of the Schiff base complexes (1) as water-soluble chemiluminogenic nanoparticles (CLNPs) and successfully employed them as activatable chemiluminescence bioprobes for precise and rapid imaging of hypochlorite-related biological events both in vitro and in vivo. We believe that this significant finding of the development of chemiluminogenic Schiff base complexes will greatly facilitate the designing of innovative chemiluminophores for theranostic applications.

Activatable Photosensitizers: From Fundamental Principles to Advanced Designs

Photodynamic therapy (PDT) is a promising treatment that uses light to excite photosensitizers in target tissue, producing reactive oxygen species and localized cell death. It is recognized as a minimally invasive, clinically approved cancer therapy with additional preclinical applications in arthritis, atherosclerosis, and infection control. A hallmark of ideal PDT is delivering disease-specific cytotoxicity while sparing healthy tissue. However, conventional photosensitizers often suffer from non-specific photoactivation, causing off-target toxicity. Activatable photosensitizers (aPS) have emerged as more precise alternatives, offering controlled activation. Unlike traditional photosensitizers, they remain inert and photoinactive during circulation and off-target accumulation, minimizing collateral damage. These photosensitizers are designed to "turn on" in response to disease-specific biostimuli, enhancing therapeutic selectivity and reducing off-target effects. This review explores the principles of aPS, including quenching mechanisms stemming from activatable fluorescent probes and applied to activatable photosensitizers (RET, PeT, ICT, ACQ, AIE), as well as pathological biostimuli (pH, enzymes, redox conditions, cellular internalization), and bioresponsive constructs enabling quenching and activation. We also provide a critical assessment of unresolved challenges in aPS development, including limitations in targeting precision, selectivity under real-world conditions, and potential solutions to persistent issues (dual-lock, targeting moieties, biorthogonal chemistry and artificial receptors). Additionally, it provides an in-depth discussion of essential research design considerations needed to develop translationally relevant aPS with improved therapeutic outcomes and specificity.

Chemical Energy Lights Up Europium-Based Ultra-bright Afterglow for Bioanalysis Application

Photochemical afterglow materials are gaining great attention for the property to continuously emit light after the excitation source is removed. However, their limited luminescence quantum yield (QY) and brightness hinder the use in biological applications. In this study, we introduce a novel photochemical afterglow system that combines a newly designed photoenergy cache unit (PCU) with an emitter through coordination covalent bonds. The PCU boasts a dark state to significantly emit photons only through chemiexcitation in the process of photochemical reactions, facilitating direct energy transfer to the emitter and resulting in bright afterglow. The related mechanisms further guided us to achieve the highest reported afterglow luminescence quantum yield of 27.5 %. The system can be encapsulated and dispersed in aqueous solutions for in vivo bioimaging in living mice under mild and simple conditions (low concentration, low excitation power, short excitation time, short exposure time), and also for in vitro diagnostic through lateral flow immunoassay, enabling the highly sensitive detection of the inflammatory biomarker serum amyloid A (SAA) and demonstrating excellent correlation with clinical test results. This study offers new insights into enhancing luminescence QY and brightness of afterglow, highlighting the potential of such systems for further biomedical applications.

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.

PhotoChem Interplays: Lighting the Way for Drug Delivery and Diagnosis

Light, a non-invasive tool integrated with cutting-edge nanotechnologies, has driven transformative advancements in imaging-based diagnosis and drug delivery for cancer and bacterial treatments. This review discusses recent progress in these areas, beginning with emerging imaging technologies. Unlike traditional photosensors activated by visible light, alternative energy sources such as near-infrared (NIR) light, X-rays, and ultrasound have been extensively investigated to activate various photosensors, achieving high sensitivity, wavelength versatility, and spatial resolution for deep-tissue imaging. Moreover, to address challenges like tissue autofluorescence in real-time fluorescence imaging, afterglow luminescent nanoparticles are being developed by integrating these alternative energy sources for real-time imaging and sensing in deep tissue for precise cancer diagnosis and treatment beyond superficial tissues. In addition to deep tissue imaging, light-responsive nanomedicines are revolutionizing anticancer and antimicrobial phototherapy by enabling spatially and temporally controlled drug release. These smart nanoparticles are engineered to release therapeutic cargo at target sites in response to microenvironmental cues specific to tumors or infections. In anticancer phototherapy, these nanoparticles facilitate controlled drug release via photoisomerization, photothermal, and photodynamic processes. To enhance circulation time and specific targeting, biomimetic nanoparticles, which mimic natural anti-tumor responses by our body, have attracted increasing attention. In antimicrobial phototherapy, research has been focused on the chemical modification of the photosensitizer to enable targeted drug delivery. An intriguing strategy has recently emerged involving the development of "pro-photosensitizers" that are specifically activated within bacterial cells upon light irradiation, offering a high margin of safety. These advancements leverage photochemical reactions and nanotechnology to enhance precision therapy and diagnosis in addressing critical health challenges.

Ultrabright difuranfluoreno-dithiophen polymers for enhanced afterglow imaging of atherosclerotic plaques

Cardiovascular diseases, including stroke driven by atherosclerosis, remain a leading global health concern. Current diagnostic imaging modalities such as magnetic resonance imaging fail to characterize oxidative stress within atherosclerotic plaques. Here, we introduce difuranfluoreno-dithiophen-based polymers designed for afterglow imaging, offering ultrabright luminescence, ultralow-power excitation (0.087 milliwatts per square centimeter), and ultrashort acquisition times (0.01 seconds). Through a molecular engineering strategy, we have optimized polymers for enhanced reactive oxygen species (ROS) generation capability, ROS capturing capability, and fluorescence quantum yield, resulting in an increase in afterglow intensity (~130-fold) compared to commonly used 2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene polymer (MEHPPV). Additionally, we have developed ratiometric afterglow nanoparticles doped with oxidative stress-responsive molecules, enabling imaging of oxidative stress markers in atherosclerotic plaque. This approach provides a tool for cardiovascular imaging and diagnostics, which is conducive to the auxiliary diagnosis and risk stratification of atherosclerosis.

Ultrasound-mediated nanomaterials for the treatment of inflammatory diseases

Sterile and infection-associated inflammatory diseases are becoming increasingly prevalent worldwide. Conventional drug therapies often entail significant drawbacks, such as the risk of drug overdose, the development of drug resistance in pathogens, and systemic adverse reactions, all of which can undermine the effectiveness of treatments for these conditions. Nanomaterials (NMs) have emerged as a promising tool in the treatment of inflammatory diseases due to their precise targeting capabilities, tunable characteristics, and responsiveness to external stimuli. Ultrasound (US), a non-invasive and effective treatment method, has been explored in combination with NMs to achieve enhanced therapeutic outcomes. This review provides a comprehensive overview of the recent advances in the use of US-mediated NMs for treating inflammatory diseases. A comprehensive introduction to the application and classification of US was first presented, emphasizing the advantages of US-mediated NMs and the mechanisms through which US and NMs interact to enhance anti-inflammatory therapy. Subsequently, specific applications of US-mediated NMs in sterile and infection-associated inflammation were summarized. Finally, the challenges and prospects of US-mediated NMs in clinical translation were discussed, along with an outline of future research directions. This review aims to provide insights to guide the development and improvement of US-mediated NMs for more effective therapeutic interventions in inflammatory diseases.

Precise modulation of cell activity using sono-responsive nano-transducers

Ultrasound, as a form of mechanical energy, possesses a distinctive ability to deeply penetrate tissues, allowing for non-invasive manipulation of cellular activities. Utilizing nanomaterials in conjunction with ultrasound has enabled simple, efficient, spatiotemporally controllable, and minimally invasive regulation of cellular activities with ultrasound-generated electric, optical, acoustic, or chemical stimuli at the localized nanomaterials interface. This technology allows for precise and localized regulation of cellular activities, which is essential for studying and understanding complex biological processes, and also provides new opportunities for research, diagnostics, and therapeutics in the fields of biology and medicine. In this article, we review the state-of-the-art and ongoing developments in nanomaterials-enabled ultrasound cellular modulation, highlighting potential applications and advancements achieved through the integration of sono-responsive nanomaterials with ultrasound.

Molecular Trojan Based on Membrane-Mimicking Conjugated Electrolyte for Stimuli-Responsive Drug Release

Enhancing payload encapsulation stability while enabling controlled drug release are both critical objectives in drug delivery systems but are challenging to reconcile. This study introduces a zwitterionic conjugated electrolyte (CE) molecule named Zwit, which acts as a molecular Trojan by mimicking the lipid bilayers. When integrated into liposome membranes, Zwit rigidifies the bilayer structure likely due to its hydrophobic interactions providing structural support, thus inhibiting drug leakage. Upon 808 nm laser excitation, Zwit rapidly accelerates DOX release from liposome core, likely due to light-triggered conformational changes or photothermal effects that compromise membrane permeability. These findings demonstrate Zwit's ability to overcome the challenge of simultaneously preventing premature payload leakage and enabling stimuli-responsive drug release with a single component. Additionally, Zwit exhibits excellent biocompatibility with membranes, outperforming its quaternary ammonium counterpart and commonly used dye indocyanine green (ICG). By harnessing its NIR-II emission, Zwit enables durable in vivo biodistribution tracking of nanocarriers, whereas ICG suffers from significant dye leakage. In subcutaneous tumor models, the synergistic effects of chemotherapy and thermotherapy facilitated by this light-triggered system induced a potent antitumor immune response, further enhancing anticancer efficacy. This work underscores the potential of membrane-mimicking CEs as multifunctional tools in advanced drug delivery systems.

Molecular probes for in vivo optical imaging of immune cells

Advancing the understanding of the various roles and components of the immune system requires sophisticated methods and technology for the detection of immune cells in their natural states. Recent advancements in the development of molecular probes for optical imaging have paved the way for non-invasive visualization and real-time monitoring of immune responses and functions. Here we discuss recent progress in the development of molecular probes for the selective imaging of specific immune cells. We emphasize the design principles of the probes and their comparative performance when using various optical modalities across disease contexts. We highlight molecular probes for imaging tumour-infiltrating immune cells, and their applications in drug screening and in the prediction of therapeutic outcomes of cancer immunotherapies. We also discuss the use of these probes in visualizing immune cells in atherosclerosis, lung inflammation, allograft rejection and other immune-related conditions, and the translational opportunities and challenges of using optical molecular probes for further understanding of the immune system and disease diagnosis and prognosis.

UiO-66 MOFs-Based "Epi-Nano-Sonosensitizer" for Ultrasound-Driven Cascade Immunotherapy against B-Cell Lymphoma

B-cell lymphoma (BCL) is a hematological malignancy with high heterogeneity and represents an aggressive proliferation of mature B-cells. Despite the initial success of traditional treatments for BCL in clinical trials, a majority of patients eventually develop resistance to therapy and have poor clinical outcomes. Epigenetic dysregulation is a major contributor to the pathogenesis of BCL, and therapies targeting epigenetic pathways is a promising alternative strategy for treating BCL. Herein, we developed a metal-organic framework (MOF)-based nano-sonosensitizer for ultrasound-driven cascade immunotherapy against BCL. The nano-sonosensitizer was synthesized by encapsulating copper complex of the m6A-mRNA demethylase inhibitor into UiO-66-NH2, which possesses a Z-scheme heterostructure and allows efficient electron-hole pair separation for generating reactive oxygen species (ROS) under ultrasound activation. These CuR@UiO66 sonosensitizers were functionalized with mPEG-PO3 and anti-CD19 antibody, and the resulting CRUPPA19 particles could specifically accumulate in the BCL tissue and also target lymphoma cells that infiltrated into the bone marrow. Once internalized, CRUPPA19 could induce intracellular ROS production and apoptosis under ultrasound irradiation. Subsequently, ultrasonic stimulation triggered autophagy-mediated release of Cu and Rhein from CRUPPA19, thereby increasing protein lipoylation and global mRNA methylation, which led to cuproptosis and the transcriptional repression PDL1, respectively. These cascades synergistically induced immunogenic cell death in the tumors and promoted activation of CD8+ T cells, eventually leading to an antilymphoma immune response. CRUPPA19-mediated sono-immunotherapy not only eliminated the primary and metastatic lymphomas but also cleared lymphoma cells from the bone marrow. This study provided an insight into a MOF-based nanoepigenetic therapy platform with ultrasound-triggered cascade amplification for enhanced antihematological tumor immunity.

Recent Advances in Reactive Oxygen Species -Mediated Near-Infrared Organic Long-Persistent Luminescence Imaging

Organic luminophores have found extensive applications in cellular and in vivo fluorescence imaging. However, their efficacy is often hindered by formidable challenges, including a low signal-to-noise ratio (SNR), susceptibility to false-positive signals, limited tissue penetration depth, and autofluorescence arising from non-negligible background interference. The emergence of near-infrared (NIR) afterglow imaging has addressed these problems. Organic afterglow imaging distinguishes by its unique capacity to emit light long after the cessation of external excitation, thereby exhibiting extraordinary persistence in luminescence. The integration of deep tissue penetration with prolonged luminescence in NIR organic long-persistent luminescent materials confers a distinct advantage for in vivo biological imaging, effectively minimizing the confounding effects of autofluorescence while enhancing spatial resolution for imaging in deep tissues, which is favorable for biosensing. In this review, we present a comprehensive summary of recent advancements in reactive oxygen species (ROS)-mediated NIR organic afterglow imaging, positioning this emerging technique as an exceptionally promising approach for in vivo biosensing, biological imaging, imaging-guided surgery, and therapeutic applications. Furthermore, we critically examine the challenges facing this field and propose future avenues for its continued evolution and refinement.

Amplifying Persistent Luminescence in Heavily Doped Nanopearls for Bioimaging and Solar-to-Chemical Synthesis

Lanthanides are widely codoped in persistent luminescence phosphors (PLPs) to elevate defect concentration and enhance luminescence efficiency. However, the deleterious cross-relaxation between activators and lanthanides inevitably quenches persistent luminescence, particularly in heavily doped phosphors. Herein, we report a core-shell engineering strategy to minimize the unwanted cross-relaxation but retain the charge trapping capacity of heavily doped persistent luminescence phosphors by confining the activators and lanthanides in the core and shell, respectively. As a proof of concept, we prepared a series of codoped ZnGa2O4:Cr, Ln (CD-Ln, Ln = Nd, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) and core-shell structured ZnGa2O4:Cr@ZnGa2O4:Ln (CS-Ln) nanoparticles. First-principles investigations suggested that lanthanide doping elevated the electron trap concentration for enhancing persistent luminescence, but energy transfer (ET) from Cr3+ to Ln3+ ions quenched the persistent luminescence. The spatial separation of Cr3+ and Ln3+ ions in the core-shell structured CS-Ln nanoparticles suppressed the ET from Cr3+ to Ln3+. Due to the efficient suppression of deleterious ET, the optimal doping concentration of Ln in CS-Ln was elevated 50 times compared to CD-Ln. Moreover, the persistent luminescence intensity of CS-5%Ln was up to 60 times that of the original ZnGa2O4:Cr. The CS-5%Ln displayed significantly improved signal-to-noise ratios in bioimaging. Further, the CS-Ln was interfaced with the lycopene-producing bacteria Rhodopseudomonas palustris for solar-to-chemical synthesis, and the lycopene productivity was increased by 190%. This work provides a reliable solution to fulfill the potential of lanthanides in enhancing persistent luminescence and can further promote the applications of persistent luminescence phosphors in biomedicine and solar-to-chemical synthesis.

Recent advances and design strategies for organic afterglow agents to enhance autofluorescence-free imaging performance

Long-lasting afterglow luminescence imaging that detects photons slowly being released from chemical defects has emerged, eliminating the need for real-time photoexcitation and enabling autofluorescence-free in vivo imaging with high signal-to-background ratios (SBRs). Organic afterglow nano-systems are notable for their tunability and design versatility. However, challenges such as unsatisfactory afterglow intensity, short emission wavelengths, limited activatable strategies, and shallow tissue penetration depth hinder their widespread biomedical applications and clinical translation. Such contradiction between promising prospects and insufficient properties has spurred researchers' efforts to improve afterglow performance. In this review, we briefly outline the general composition and mechanisms of organic afterglow luminescence, with a focus on design strategies and an in-depth understanding of the structure-property relationship to advance afterglow luminescence imaging. Furthermore, pending issues and future perspectives are discussed.

HClO-Activated Near-Infrared Chemiluminescent Probes with a Malononitrile Group for In-Vivo Imaging

Chemiluminescence (CL) imaging has emerged as a powerful approach to molecular imaging that allows exceptional sensitivity with virtually no background interference because of its unique capacity to emit photons without an external excitation source. Despite its high potential, the application of this nascent technique faces challenges because the current chemiluminescent agents have limited reactive sites, require complex synthesis, are insufficiently bright, and lack near-infrared emission. Herein, a series of HClO-activated chemiluminescent probes that exhibit robust near-infrared emission are studied. Specifically engineered to respond to HClO, a known biomarker of acute inflammation, these probes achieve high-contrast in vivo imaging by eliminating the need for constant external excitation. Comprehensive experimental and theoretical investigations demonstrate that the CL of the probes depends on the reactivity of the vinylene bonds, following a concerted decomposition of the oxidized chemiluminescent molecule. The application of these chemiluminescent nanoparticles in vivo facilitates high-contrast imaging of acute inflammation, providing real-time, high-contrast visualization of inflammatory conditions. This advancement signifies a leap forward for chemiluminescent nanoplatforms in biomedical imaging and expands the available methodologies in this field.

Phytochlorin-Based Sonosensitizers Combined with Free-Field Ultrasound for Immune-Sonodynamic Cancer Therapy

Phytochlorins, a class of plant-derived tetrapyrroles, show great potential as sonosensitizers in sonodynamic therapy (SDT). The development of new phytochlorin-based sonosensitizers has significantly improved SDT, yet the absence of specialized sonodynamic systems limits their clinical translation. Herein, a dedicated ultrasound system along with a detailed step-by-step sonodynamic process from in vitro to in vivo is developed to activate phytochlorin-based sonosensitizers. Compared to standing-wave ultrasound, free-field ultrasound maintains stable acoustic pressure amplitudes and minimizes mechanical damage to cell membranes. In vitro experiments demonstrate that free-field ultrasound effectively activates naturally occurring phytochlorin, reducing the cavitation threshold for reactive oxygen species production and triggering immunogenic cell death. Furthermore, the intravenously injectable phytochlorin-based sonosensitizer (C34) enhances sonodynamic efficiency by reducing interfacial tension. Driven by in vivo free-field ultrasound, C34 effectively inhibits tumor growth in an orthotopic murine breast cancer model and elicits an immune response, preventing tumor metastasis. The reliable protocol provided by the free-field ultrasound system facilitates the activation of phytochlorin-based sonosensitizers while simultaneously stimulating the immune system, highlighting the potential of immune-sonodynamic therapy.

Activatable red/near-infrared aqueous organic phosphorescence probes for improved time-resolved bioimaging

Organic red/near-infrared (NIR) room-temperature phosphorescence (RTP) holds significant potential for autofluorescence-free bioimaging and biosensing due to its prolonged persistent luminescence and exceptional penetrability. However, achieving activatable red/NIR organic RTP probes with tunable emission in aqueous solution remains a formidable challenge. Here we report on aqueous organic RTP probes with red/NIR phosphorescence intensity and lifetime amplification. These probes consist of supramolecular assemblies comprising macrocyclic cucurbit[8]uril and amine-containing alkyl-bridged pyridiniums, exhibiting viscosity-activatable phosphorescence with enhanced quantum yield (≤20%) and lifetime. Notably, by utilizing this activatable organic RTP probe, we successfully achieve two-photon imaging of lysosomal viscosity and millisecond-scale time-resolved cell imaging. Moreover, intravital phosphorescence imaging by using an RTP probe enables the monitoring of viscosity variations in inflammatory mice, demonstrating a significantly improved signal-to-background ratio compared with fluorescence imaging. This activatable red/NIR supramolecular platform facilitates versatile high-resolution phosphorescence imaging for in vivo tracking of specific biomarkers and physiological events.

Highly Photoreactive Semiconducting Polymers with Cascade Intramolecular Singlet Oxygen and Energy Transfer for Cancer-Specific Afterglow Theranostics

Afterglow luminescence provides ultrasensitive optical detection by minimizing tissue autofluorescence and increasing the signal-to-noise ratio. However, due to the lack of suitable unimolecular afterglow scaffolds, current afterglow agents are nanocomposites containing multiple components with limited afterglow performance and have rarely been applied for cancer theranostics. Herein, we report the synthesis of a series of oxathiine-containing donor-acceptor block semiconducting polymers (PDCDs) and the observation of their high photoreactivity and strong near-infrared (NIR) afterglow luminescence. We reveal that PDCDs absorb NIR light to undergo a photodynamic process to generate singlet oxygen (1O2), which intramolecularly transfers to and efficiently reacts with the oxathiine block to form the afterglow oxathiine intermediates due to the low Gibbs free energy changes required for this photoreaction. Following intramolecular afterglow energy transfer from the oxathiine donor block to the acceptor block, NIR afterglow emission is produced from PDCDs. Owing to the efficient cascade intramolecular photochemical process, PDCD-based nanoparticles achieve a higher brightness and longer NIR emission compared to most reported afterglow agents, even after ultrashort photoirradiation for only 3 s. Furthermore, the cascade photochemical process within PDCD can be inhibited after bioconjugation with a quencher-linked peptide. This allows the construction of a cancer-activatable afterglow theranostic probe (CATP) that only switches on the afterglow signal and photodynamic function in the presence of a cancer-overexpressed enzyme. Thereby, CATP represents the first afterglow phototheranostic probe that permits cancer-specific detection and photodynamic cancer therapy under preclinical settings. In summary, this study provides a molecular guideline to develop afterglow probes from photoreactive polymers.

An Emerging Toolkit of Ho3+ Sensitized Lanthanide Nanocrystals with NIR-II Excitation and Emission for in Vivo Bioimaging

Optical imaging in the second near-infrared window (NIR-II, 1000-1700 nm) holds great promise for biomedical detection due to reduced tissue scattering and autofluorescence. However, the rational design of NIR-II probes with superior excitation wavelengths to balance the effects of tissue scattering and water absorption remains a great challenge. To address this issue, here we developed a series of Ho3+-sensitized lanthanide (Ln) nanocrystals (NaYF4: Ho, Ln@NaYF4) excited at 1143 nm, featuring tunable emissions ranging from 1000 to 2200 nm for in vivo bioimaging. Precise core-shell engineering (β-NaYF4: Ho@NaYF4: Ln@NaYF4 and β-NaYF4: Ho/Yb@NaYbF4@NaYbF4: Ln@NaYF4) further endows the Ho3+-sensitized system with the capability of energy migration within interfaces, enabling more abundant visible and NIR-II emissions that are unattainable in co-doped structures due to detrimental cross relaxation. Tissue phantom studies demonstrated the superior tissue penetration ability of 1143 photons, especially in imaging experiments through the highly photon-scattering skull, where the fluorescence transmittance of 1143 nm excited nanocrystals was 15% and 10% higher than that of the conventional 808 and 980 excitation, respectively. By leveraging these Ho3+-sensitized nanomaterials with multiemission characteristics and well-selected lanthanide nanomaterials with crosstalk-free excitation, we achieved six-channel NIR-II in vivo imaging, enabling the simultaneous visualization of blood vessels, liver, spleen, stomach, intestine, subcutaneous tumors, and lymph nodes in mice. Our research provides new insights into the design of lanthanide nanocrystals with NIR-II excitation and emission and highlights the potential of these materials in in vivo multichannel detection.

Hypoxia-tolerant polymeric photosensitizer prodrug for cancer photo-immunotherapy

Although photodynamic immunotherapy represents a promising therapeutic approach against malignant tumors, its efficacy is often hampered by the hypoxia and immunosuppressive conditions within the tumor microenvironment (TME) following photodynamic therapy (PDT). In this study, we report the design guidelines towards efficient Type-I semiconducting polymer photosensitizer and modify the best-performing polymer into a hypoxia-tolerant polymeric photosensitizer prodrug (HTPSNiclo) for cancer photo-immunotherapy. HTPSNiclo not only performs Type-I PDT process to partially overcome the limitation of hypoxic tumors in PDT by recycling oxygen but also specifically releases a Signal Transducer and Activator of Transcription-3 (STAT3) inhibitor (Niclosamide) in response to a cancer biomarker in the TME. Consequently, HTPSNiclo inhibits the phosphorylation of STAT3, and suppresses the expression of hypoxia-inducible factor-1α. The synergistic effect results in the enhanced activation of immune cells (including mature dendritic cells, cytotoxic T cells) and production of immunostimulatory cytokines compared to Type-I PDT alone. Thus, HTPSNiclo-mediated photodynamic immunotherapy enhances tumor inhibition rate from 75.53% to 91.23%, prolongs the 100% survival from 39 days to 60 days as compared to Type-I PDT alone. This study not only provides the generic approach towards design of polymer-based Type-I photosensitizers but also uncovers effective strategies to counteract the immunosuppressive TME for enhanced photo-immunotherapy in 4T1 tumor bearing female BALB/c mice.

Molecular Engineering of Direct Activated NIR-II Chemiluminescence Platform for In Vivo Chemiluminescence-fluorescence Duplex Imaging

Chemiluminescence (CL) is a self-illuminating phenomenon fueled by chemical energy instead of extra excited light, which features superiority in sensitivity, signal-to-background ratios, and imaging depth. Strategies to synthesize a CL emission unimolecular skeleton in the second near-infrared window (NIR-II) and a unimolecular probe with direct duplex NIR-II [CL/fluorescence (FL)] emission are lacking. Here, we employ modular synthesis routes to construct a series of directly activated NIR-II CL emission unimolecular probes with a maximum emission wavelength of up to 1060 nm, and use them for real-time and continuous detection of the superoxide anion generated in acetaminophen induced liver injury in a female mice model under both NIR-II CL and NIR-II FL imaging channels. Thus, this study establishes a directly activatable NIR-II CL emission unimolecular skeleton, validating the scalability of this duplex NIR-II CL/FL imaging platform in bioactive molecule detection and disease diagnosis.

Cascade-Activatable Nanoprodrug System Augments Sonochemotherapy of Bladder Cancer

Sonochemotherapy (SCT) has emerged as a powerful modality for cancer treatment by triggering excessive production of reactive oxygen species (ROS) and controlled release of chemotherapeutic agents under ultrasound. However, achieving spatiotemporally controlled release of chemotherapeutic agents during ROS generation is still an enormous challenge. In this work, we developed a cascade-activated nanoprodrug (CAN) system that utilizes a reversible covalent Schiff base mixed with a hypoxia-activatable camptothecin (CPT) prodrug. Briefly, the designed fluorinated CAN system is self-assembled into nanoparticles under aqueous conditions, which could penetrate deep tumors to offer sufficient oxygen for ultrasound-triggered ROS production. Consequently, the nanoparticles substantially exacerbated the hypoxia of the tumor microenvironment (TME) by elevating oxygen consumption. The aggravated hypoxia in turn served as a positive amplifier to boost the tumor-specific CPT release of Azo-CPT prodrug, which made up for the insufficient treatment efficacy of sonodynamic therapy (SDT). On this basis, we observed a substantial reduction, approximately 3.5-fold, in the half-maximal inhibitory concentration (IC50) of the CAN system compared to that of free CPT in bladder cancer cell lines (T24). Furthermore, the CAN system demonstrated potent antitumor efficacy with reduced side effects, resulting in regression and eradication of T24 tumors in various mouse models. In summary, the CAN system can be easily extended by incorporating different chemotherapeutic agents, showing great potential to revolutionize the clinical management paradigm of bladder cancer.

Sonodynamic Nano-LYTACs Reverse Tumor Immunosuppressive Microenvironment for Cancer Immunotherapy

Extracellular and transmembrane proteins, which account for the products of approximately 40% of all protein-encoding genes in tumors, play a crucial role in shaping the tumor immunosuppressive microenvironment (TIME). While protein degradation therapy has been applied to membrane proteins of cancer cells, it has rarely been extended to immune cells. We herein report a polymeric nanolysosome targeting chimera (nano-LYTAC) that undergoes membrane protein degradation on M2 macrophages and generates a sonodynamic effect for combinational cancer immunotherapy. Nano-LYTAC is found to have higher degradation efficacy to the interleukin 4 receptor (IL-4R) compared to traditional inhibitors. More importantly, it is revealed that the effect of nano-LYTAC on the function of the M2 macrophage is concentration-dependent: downregulating CD206 expression and interleukin 10 (IL-10) secretion from M2 macrophages at low concentration, while triggering their apoptosis at high concentration. Moreover, nano-LYTAC is found to possess long tumor retention (>48 h), allowing for multiple sonodynamic treatments with a single dose. Such a synergistic sonodynamic immunotherapy mediated by nano-LYTAC effectively reprograms the TIME via inhibiting the functions of M2 macrophages and regulatory T cells (Tregs), as well as promoting the maturation of dendritic cells (DCs) and tumor infiltration of T effector cells (Teffs), completely suppressing tumor growth, inhibiting pulmonary metastasis, and preventing recurrence under preclinical animal models.

DNA Nanopatch-Specific Modification of Probiotics for Ultrasound-Triggered Inflammatory Bowel Disease Therapy

Probiotics offer promising results for treating inflammatory bowel disease, yet precision therapy remains challenging, particularly in manipulating probiotics spatially and temporally and shielding them from oxidative stress. To address these limitations, herein we synthesized bacteria-specific DNA nanopatches to modify ultrasound-triggered engineered Escherichia coli Nissle 1917. These probiotics produced the anti-inflammatory cytokine interleukin-10 when stimulated by ultrasound and were fortified with DNPs for oxidative stress resistance. The DNPs were composed of rectangular DNA origami nanosheets with reactive oxygen species' scavenging ability and bacterial targeting ligands of maltodextrin molecules. We systematically demonstrated that the DNPs could selectively attach to bacterial surface but not mammalian cell surface via the maltodextrin transporter pathway. To further enhance the bioavailability of engineered probiotics in the gastrointestinal tract, we employed a self-assembly strategy to encapsulate them using chitosan and sodium alginate. In a murine model of ulcerative colitis, this system significantly improved the gut barrier integrity and reduced inflammation. Our results indicate that this DNA nanopatch-bacteria system holds substantial promise for mitigating oxidative stress, correcting microbiota dysbiosis, and enhancing the intestinal barrier function in colitis.

A DNAzyme-Based Nanohybrid for Ultrasound and Enzyme Dual-Controlled mRNA Regulation and Combined Tumor Treatment

Despite the significant potential of RNA-cleaving DNAzymes for gene regulation, their application is limited by low therapeutic efficacy and lack of cell-specific control. Here, a DNAzyme-based nanohybrid designed for ultrasound (US)-controlled, enzyme-activatable mRNA regulation is presented, enabling tumor cell-selective combination therapy. The nanohybrid is constructed by coordination-directed self-assembly of an enzymatically-triggerable therapeutic DNAzyme (En-Dz) and natural sonosensitizer hemoglobin (Hb). Controlled US exposure induces reactive oxygen species generation from Hb units, which not only facilitates efficient endosomal escape of En-Dz, but also promotes the translocation of specific enzyme from the nucleus to the cytoplasm, thereby enhancing gene regulation efficacy. Notably, the enzyme-triggered, spatiotemporally-controlled activation of En-Dz's catalytic activity results in enhanced cancer-cell selectivity in the therapeutic treatment. Furthermore, the combination of enzyme-activated mRNA regulation and sonodynamic therapy significantly enhances anti-tumor efficacy both in vitro and in vivo. This work highlights the potential of integrating a sonodynamic strategy to overcome the current limitations of DNAzyme-based gene regulators, providing a spatiotemporally-controlled approach for precise tumor treatment.

A Bicyclic Dioxetane Chemiluminescence Nanoprobe for Peroxynitrite Imaging in Vivo

Peroxynitrite (ONOO-) is a critical biomarker associated with a wide array of diseases including cancer, inflammatory conditions, and neurodegenerative disorders. This study introduces an innovative chemiluminescence nanoprobe (CLNP) based on a bicyclic dioxetane structure, designed for highly sensitive and specific in vivo imaging of ONOO-. Our CLNP demonstrates exceptional capabilities in generating high-contrast imaging of disease lesions, with applications verified across tumor models, acute inflammation, and acute liver injury scenarios. Key findings highlight the probe's rapid response to oxidative species, superior tissue penetration, and high signal-to-noise ratio, underscoring its potential for real-time diagnostic applications. This work represents an important advance in the field of diagnostic imaging using CL probes, offering promising avenues for the early detection and treatment of ONOO--related pathologies.

Diagnostic and therapeutic optical imaging in cardiovascular diseases

Cardiovascular disease (CVD) is one of the most prevalent health threats globally. Traditional diagnostic methods for CVDs, including electrocardiography, ultrasound, and cardiac magnetic resonance imaging, have inherent limitations in real-time monitoring and high-resolution visualization of cardiovascular pathophysiology. In recent years, optical imaging technology has gained considerable attention as a non-invasive, high-resolution, real-time monitoring solution in the study and diagnosis of CVD. This review discusses the latest advancements, and applications of optical techniques in cardiac imaging. We compare the advantages of optical imaging over traditional modalities and especially scrutinize techniques such as optical coherence tomography, photoacoustic imaging, and fluorescence imaging. We summarize their investigations in atherosclerosis, myocardial infarction, and heart valve disease, etc. Additionally, we discuss challenges like deep-tissue imaging and high spatiotemporal resolution adjustment, and review existing solutions such as multimodal integration, artificial intelligence, and enhanced optical probes. This article aims to drive further development in optical imaging technologies to provide more precise and efficient tools for early diagnosis, pathological mechanism exploration, and treatment of CVD.

PEGylated BODIPY Photosensitizer for Type I Dominant Photodynamic Therapy and Afterglow Imaging

Type I photodynamic therapy (PDT) exhibits outstanding therapeutic effects in hypoxic environments in tumors, but the design of type I photosensitizers (PSs), especially those with simple structures but dramatic properties, remains a challenge. Herein, we report a design strategy for developing type I PSs in one molecule with afterglow luminescence. As a proof concept, a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) PS (BIP) bearing water-soluble poly(ethylene glycol) (mPEG550) chains is synthesized, and BIP can self-assemble into nanoparticles (BIPNs). Interestingly, BIPNs exhibit an O2•--triggered afterglow luminescence, which is scarce, especially for BODIPY derivatives. BIPNs demonstrate outstanding type I dominant PDT at an ultralow dose under both hypoxic and normoxic environments, which can significantly inhibit tumor growth under irradiation. This work highlights a high-performance PS with afterglow luminescence and excellent PDT effects, underscoring the significant potential of versatile PSs in clinical tumor theranostics.

Light/X-ray/ultrasound activated delayed photon emission of organic molecular probes for optical imaging: mechanisms, design strategies, and biomedical applications

Conventional optical imaging, particularly fluorescence imaging, often encounters significant background noise due to tissue autofluorescence under real-time light excitation. To address this issue, a novel optical imaging strategy that captures optical signals after light excitation has been developed. This approach relies on molecular probes designed to store photoenergy and release it gradually as photons, resulting in delayed photon emission that minimizes background noise during signal acquisition. These molecular probes undergo various photophysical processes to facilitate delayed photon emission, including (1) charge separation and recombination, (2) generation, stabilization, and conversion of the triplet excitons, and (3) generation and decomposition of chemical traps. Another challenge in optical imaging is the limited tissue penetration depth of light, which severely restricts the efficiency of energy delivery, leading to a reduced penetration depth for delayed photon emission. In contrast, X-ray and ultrasound serve as deep-tissue energy sources that facilitate the conversion of high-energy photons or mechanical waves into the potential energy of excitons or the chemical energy of intermediates. This review highlights recent advancements in organic molecular probes designed for delayed photon emission using various energy sources. We discuss distinct mechanisms, and molecular design strategies, and offer insights into the future development of organic molecular probes for enhanced delayed photon emission.

The advance of ultrasound-enabled diagnostics and therapeutics

Point-of-care ultrasound demonstrates significant potential in biomedical research due to its noninvasive, real-time visualization, cost-effectiveness, and other biological benefits. Ultrasound irradiation can precisely control the mechanical and physicochemical effects on pathogenic lesions, enabling real-time visualization, tunable tissue penetration depth, and therapeutic applications. This review summarizes recent advancements in ultrasound-enabled diagnostics and therapeutics, focusing on mechanochemical effects that can be directly integrated into biomedical applications. Additionally, the structure-functionality relationships of sonotheranostic nanoplatforms are systematically discussed, providing insights into the underlying biological effects. Finally, the limitations of current ultrasonic medicine are discussed, along with potential expansions to facilitate patient-centered translations.

Closed-Loop Control of Macrophage Engineering Enabled by Focused-Ultrasound Responsive Mechanoluminescence Nanoplatform for Precise Cancer Immunotherapy

Macrophage engineering has emerged as a promising approach for modulating the anti-tumor immune response in cancer therapy. However, the spatiotemporal control and real-time feedback of macrophage regulatory process is still challenging, leading to off-targeting effect and delayed efficacy monitoring therefore raising risk of immune overactivation and serious side effects. Herein, a focused ultrasound responsive immunomodulator-loaded optical nanoplatform (FUSION) is designed to achieve spatiotemporal control and status reporting of macrophage engineering in vivo. Under the stimulation of focused ultrasound (FUS), the immune agonist encapsulated in FUSION can be released to induce selective macrophage M1 phenotype differentiation at tumor site and the near-infrared mechanoluminescence of FUSION is generated simultaneously to indicate the initiation of immune activation. Meanwhile, the persistent luminescence of FUSION is enhanced due to hydroxyl radical generation in the pro-inflammatory M1 macrophages, which can report the effectiveness of macrophage regulation. Then, macrophages labeled with FUSION as a living immunotherapeutic agent (FUSION-M) are utilized for tumor targeting and focused ultrasound activated, immune cell-based cancer therapy. By combining the on-demand activation and feedback to form a closed loop, the nanoplatform in this work holds promise in advancing the controllability of macrophage engineering and cancer immunotherapy for precision medicine.

Bimetal-Biligand Frameworks for Spatiotemporal Nitric Oxide-Enhanced Sono-Immunotherapy

Sonodynamic therapy can trigger immunogenic cell death to augment immunotherapy, benefiting from its superior spatiotemporal selectivity and non-invasiveness. However, the practical applications of sonosensitizers are hindered by their low efficacy in killing cancer cells and activating immune responses. Here, two US Food and Drug Administration-approved drug ligands (ferricyanide and nitroprusside) and two types of metals (copper/iron) are selected to construct a bimetal-biligand framework (Cu[PBA-NO]). Through elaborate regulation of multiple metal/ligand coordination, the systemically administered Cu[PBA-NO] nanoagent shows sono-catalytic and NO release ability under ultrasound irradiation, which can be used for effective sono-immunotherapy. Moreover, Cu[PBA-NO] can downregulate intracellular glutathione levels that would destroy intracellular redox homeostasis and facilitate reactive oxygen species accumulation. The released tumor-associated antigens subsequently facilitate dendritic cell maturation within the tumor-draining lymph node, effectively initiating a T cell-mediated immune response and thereby bolstering the capacity to identify and combat cancer cells. This study paves a new avenue for the efficient cancer sono-immunotherapy.

X-ray/γ-ray/Ultrasound-Activated Persistent Luminescence Phosphors for Deep Tissue Bioimaging and Therapy

Persistent luminescence phosphors (PLPs) can remain luminescent after excitation ceases and have been widely explored in bioimaging and therapy since 2007. In bioimaging, PLPs can efficiently avoid tissue autofluorescence and light scattering interference by collecting persistent luminescence signals after the end of excitation. Outstanding signal-to-background ratios, high sensitivity, and resolution have been achieved in bioimaging with PLPs. In therapy, PLPs can continuously produce therapeutic molecules such as reactive oxygen species after removing excitation sources, which realizes sustained therapeutic activity after a single dose of light stimulation. However, most PLPs are activated by ultraviolet or visible light, which makes it difficult to reactivate the PLPs in vivo, particularly in deep tissues. In recent years, excitation sources with deep tissue penetration have been explored to activate PLPs, including X-ray, γ-ray, and ultrasound. Researchers found that various inorganic and organic PLPs can be activated by X-ray, γ-ray, and ultrasound, making these PLPs valuable in the imaging and therapy of deep-seated tumors. These X-ray/γ-ray/ultrasound-activated PLPs have not been systematically introduced in previous reviews. In this review, we summarize the recently developed inorganic and organic PLPs that can be activated by X-ray, γ-ray, and ultrasound to produce persistent luminescence. The biomedical applications of these PLPs in deep-tissue bioimaging and therapy are also discussed. This review can provide instructions for the design of PLPs with deep-tissue-renewable persistent luminescence and further promote the applications of PLPs in phototheranostics, noninvasive biosensing devices, and energy harvesting.

Sonocatalysis Regulates Tumor Autophagy for Enhanced Immunotherapy

Immunotherapy stands as a groundbreaking strategy for cancer treatment, due to its ability to precisely and safely detect and eradicate tumors. However, the efficacy of immunotherapy is often limited by tumor autophagy, a natural defense mechanism that tumors exploit to resist immune attacks. Herein, we introduce a spatiotemporally controlled method to modulate tumor autophagy via sonocatalysis, aiming to improve immunotherapeutic outcomes. Specifically, we synthesized a tumor-targeting nanocatalyst based on a semiconductor heterojunction composed of Barium Titanate (BTO), Black Phosphorus (BP) integrated with Hyaluronic Acid (HA), referred to as BTO/BP-HA. Compared to traditional catalysts, the heterojunction structure enhances energy band bending and rapid electron-hole separation under ultrasonic stimulation, splitting water to generate H2. This promotes tumor cell apoptosis by inhibiting mitochondrial respiration and induces immunogenic cell death, triggering immune responses to eliminate tumor cells. However, the concurrent activation of autophagy mitigates the cytotoxic effectiveness of nanocatalysts. Within the nanocatalyst, BP undergoes lysosomal degradation to generate PO43-, which subsequently interacts with H+ to generate a conjugated acidic anion, increasing the lysosomal pH. This research ingeniously combines sonocatalysis with tumor autophagy, disrupting the activity of acidic hydrolases to inhibit autophagy, thereby enhancing the immune response and improving the effectiveness of immunotherapy.

Exciton Dissociation and Recombination Afford Narrowband Organic Afterglow Through Efficient FRET

Organic afterglow with long-persistent luminescence (LPL) after photoexcitation is highly attractive, but the realization of narrowband afterglow with small full-width at half-maximum (FWHM) is a huge challenge since it is intrinsically contradictory to the triplet- and solid-state emission nature of organic afterglow. Here, narrow-band, long-lived, and full-color organic LPL is realized by isolating multi-resonant thermally activated delayed fluorescent (MR-TADF) fluorophores in a glassy steroid-type host through a facile melt-cooling treatment. Such prepared host becomes capable of exciton dissociation and recombination (EDR) upon photoirradiation for both long-lived fluorescence and phosphorescence; and, the efficient Förster resonance energy transfer (FRET) from the host to various MR-TADF emitters leads to high-performance LPL, exhibiting small FWHM of 33 nm, long persistent time over 10 s, and facile color-tuning in a wide range from deep-blue to orange (414-600 nm). Moreover, with the extraordinary narrowband LPL and easy processability of the material, centimeter-scale flexible optical waveguide fibers and integrated FWHM/color/lifetime-resolved multilevel encryption/decryption devices have been designed and fabricated. This novel EDR and singlet/triplet-to-singlet FRET strategy to achieve excellent LPL performances illustrates a promising way for constructing flexible organic afterglow with easy preparation methods, shedding valuable scientific insights into the design of narrow-band emission in organic afterglow.

Interference of ATP-Adenosine Axis by Engineered Biohybrid for Amplifying Immunogenic Cell Death-Mediated Antitumor Immunotherapy

Immunogenic cell death (ICD) often results in the production and accumulation of adenosine (ADO), a byproduct that negatively impacts the therapeutic effect as well as facilitates tumor development and metastasis. Here, an innovative strategy is elaborately developed to effectively activate ICD while avoiding the generation of immunosuppressive adenosine. Specifically, ZIF-90, an ATP-responsive consumer, is synthesized as the core carrier to encapsulate AB680 (CD73 inhibitor) and then coated with an iron-polyphenol layer to prepare the ICD inducer (AZTF), which is further grafted onto prebiotic bacteria via the esterification reaction to obtain the engineered biohybrid (Bc@AZTF). Particularly, the designed Bc@AZTF can actively enrich in tumor sites and respond to the acidic tumor microenvironment to offload AZTF nanoparticles, which can consume intracellular ATP (iATP) content and simultaneously inhibit the ATP-adenosine axis to reduce the accumulation of adenosine, thereby alleviating adenosine-mediated immunosuppression and strikingly amplifying ICD effect. Importantly, the synergy of anti-PD-1 (αPD-1) with Bc@AZTF not only establishes a collaborative antitumor immune network to potentiate effective tumoricidal immunity but also activates long-lasting immune memory effects to manage tumor recurrence and rechallenge, presenting a new paradigm for ICD treatment combined with adenosine metabolism.

Near Infrared-Fluorescent Dinuclear Iridium(III) Nanoparticles for Immunogenic Sonodynamic Therapy

Dinuclear iridium(III) complexes activated by light-inducible spatiotemporal control are emerging as promising candidates for cancer therapy. However, broader applications of current light-activated dinuclear iridium(III) complexes are limited by the ineffective tissue penetration and undesirable feedback on guidance activation. Here, an ultrasound (US) triggered near infrared-fluorescent dinuclear iridium(III) nanoparticle, NanoIr, is first reported to precisely and spatiotemporally inhibit tumor growth. It is demonstrated that reactive oxygen species can be generated by NanoIr upon exposure to US irradiation (NanoIr + US), thereby inducing immunogenic cell death. When combined with cisplatin, NanoIr + US elicits synergistic effects in patient-derived tumor xenograft mice models of ovarian cancer. This work first provides a design of dinuclear iridium(III) nanoparticles for immunogenic sonodynamic therapy.

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.

Chemistry-Enabled Intercellular Enzymatic Labeling for Monitoring the Immune Effects of Cytotoxic T Lymphocytes In Vivo

Monitoring the effector function of cytotoxic T lymphocytes (CTLs) in vivo remains a great challenge. Here, we develop a chemistry-enabled enzymatic labeling approach to evaluate the tumor-specific immune response of CTLs by precisely monitoring the interaction between CTLs and tumor cells. Staphylococcus aureus sortase A (SrtA) is linked to the CTL surface through bioconjugate chemistry and then catalyzes the transfer of fluorescent-labeled substrate, 5-Tamra-LPETG, to CTLs. Meanwhile, the tumor cells are specifically decorated with N-terminal glycine residues (G5 peptide) through the inherent glycolmetabolism of cathepsin B-specific cleavable triacetylated N-azidoacetyl-d-mannosamine (CB-Ac3ManNAz) and click chemistry. After the infiltration of engineered CTLs into the tumor tissues, the immune-synapse-mediated specific interaction of CTLs and tumor cells leads to the accurate fluorescent labeling of tumor cells through the SrtA-catalyzed 5-Tamra-LPETG transfer. Therefore, the immune effect of CTLs as well as the performance of immune drugs can be determined, providing a novel strategy for pushing ahead immunotherapy.

Sonosynthetic Cyanobacteria Oxygenation for Self-Enhanced Tumor-Specific Treatment

Photosynthesis, essential for life on earth, sustains diverse processes by providing nutrition in plants and microorganisms. Especially, photosynthesis is increasingly applied in disease treatments, but its efficacy is substantially limited by the well-known low penetration depth of external light. Here, ultrasound-mediated photosynthesis is reported for enhanced sonodynamic tumor therapy using organic sonoafterglow (ultrasound-induced afterglow) nanoparticles combined with cyanobacteria, demonstrating the proof-of-concept sonosynthesis (sonoafterglow-induced photosynthesis) in cancer therapy. Chlorin e6, a typical small-molecule chlorine, is formulated into nanoparticles to stimulate cyanobacteria for sonosynthesis, which serves three roles, i.e., overcoming the tissue-penetration limitations of external light sources, reducing hypoxia, and acting as a sonosensitizer for in vivo tumor suppression. Furthermore, sonosynthetic oxygenation suppresses the expression of hypoxia-inducible factor 1α, leading to reduced stability of downstream SLC7A11 mRNA, which results in glutathione depletion and inactivation of glutathione peroxidase 4, thereby inducing ferroptosis of cancer cells. This study not only broadens the scope of microbial nanomedicine but also offers a distinct direction for sonosynthesis.

Harnessing and Mimicking Bacterial Features to Combat Cancer: From Living Entities to Artificial Mimicking Systems

Bacterial-derived micro-/nanomedicine has garnered considerable attention in anticancer therapy, owing to the unique natural features of bacteria, including specific targeting ability, immunogenic benefits, physicochemical modifiability, and biotechnological editability. Besides, bacterial components have also been explored as promising drug delivery vehicles. Harnessing these bacterial features, cutting-edge physicochemical and biotechnologies have been applied to attenuated tumor-targeting bacteria with unique properties or functions for potent and effective cancer treatment, including strategies of gene-editing and genetic circuits. Further, the advent of bacteria-inspired micro-/nanorobots and mimicking artificial systems has furnished fresh perspectives for formulating strategies for developing highly efficient drug delivery systems. Focusing on the unique natural features and advantages of bacteria, this review delves into advances in bacteria-derived drug delivery systems for anticancer treatment in recent years, which has experienced a process from living entities to artificial mimicking systems. Meanwhile, a summary of relative clinical trials is provided and primary challenges impeding their clinical application are discussed. Furthermore, future directions are suggested for bacteria-derived systems to combat cancer.

Preparation of AIEgen-based near-infrared afterglow luminescence nanoprobes for tumor imaging and image-guided tumor resection

Fluorescence imaging represents a vital tool in modern biology, oncology and biomedical applications. Afterglow luminescence (AGL), which circumvents the light scattering and tissue autofluorescence interference associated with real-time excitation source, shows remarkably increased imaging sensitivity and depth. Here we present a protocol for the design and synthesis of AGL nanoprobes with an aggregation-induced emission (AIE) effect to simultaneously red shift and amplify the afterglow signal for tumor imaging and image-guided tumor resection. The nanoprobe (AGL AIE dot) is composed of an enol ether format of Schaap's agent and a near-infrared AIE fluorogen (AIEgen) (tetraphenylethylene-phenyl-dicyanomethylene-4H-chromene, TPE-Ph-DCM) to suppress the nonradiative dissipation pathway. Pre-irradiating AGL AIE dots with white light could generate singlet oxygen to convert Schaap's agent to its 1,2-dioxetane format, thus initializing the AGL process. With the aid of AIEgen, the AGL shows simultaneously red shifted emission maximum (from ~540 nm to ~625 nm) and enhanced intensity (by 3.2-fold), facilitating better signal-to-background ratio, imaging sensitivity and depth. Intriguingly, the activated AGL can last for over 10 days. Compared with conventional approaches, our method provides a new solution to concurrently red shift and amplify afterglow signals for better in vivo imaging outcomes. The preparation of AGL AIE dots takes ~2 days, the in vitro characterization takes ~10 days (less than 1 day if not involving afterglow kinetic profile study) and the tumor imaging and image-guided tumor resection takes ~7 days. These procedures can be easily reproduced and amended after standard laboratory training in chemical synthesis and animal handling.

Michael Addition-Based Neoadjuvant for Enhanced Cancer Immunotherapy

Cancer immunotherapy suffers from inefficient antigen presentation owing to the limited endocytosis of antigen by dendritic cells (DCs) and dysfunction of DCs in the immunosuppressive tumor microenvironment (ITME). Here, we revealed that cinnamaldehyde-grafted polyethylenimine (PC) held the potential to serve as a neoadjuvant to modulate the above processes and thus potentiate immune responses. The PC neoadjuvant could capture the tumor antigen generated during chemotherapy to enhance the crosstalk between the antigen and DCs. Then, it depleted the intracellular glutathione by the in situ Michael addition reaction, which not only activated the NOD-, LRR-, and pyrin domain-containing 3 (NLRP3) pathway to promote DCs maturation but also triggered the antigen release. As a result, it significantly augmented antigen presentation with a 46% ratio of DCs maturation and a 53% ratio of CD8+ T cell infiltration in low immunogenic murine breast cancer.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

Remote Control of Energy Transformation-Based Cancer Imaging and Therapy

Cancer treatment requires precise tumor-specific targeting at specific sites that allows for high-resolution diagnostic imaging and long-term patient-tailorable cancer therapy; while, minimizing side effects largely arising from non-targetability. This can be realized by harnessing exogenous remote stimuli, such as tissue-penetrative ultrasound, magnetic field, light, and radiation, that enable local activation for cancer imaging and therapy in deep tumors. A myriad of nanomedicines can be efficiently activated when the energy of such remote stimuli can be transformed into another type of energy. This review discusses the remote control of energy transformation for targetable, efficient, and long-term cancer imaging and therapy. Such ultrasonic, magnetic, photonic, radiative, and radioactive energy can be transformed into mechanical, thermal, chemical, and radiative energy to enable a variety of cancer imaging and treatment modalities. The current review article describes multimodal energy transformation where a serial cascade or multiple types of energy transformation occur. This review includes not only mechanical, chemical, hyperthermia, and radiation therapy but also emerging thermoelectric, pyroelectric, and piezoelectric therapies for cancer treatment. It also illustrates ultrasound, magnetic resonance, fluorescence, computed tomography, photoluminescence, and photoacoustic imaging-guided cancer therapies. It highlights afterglow imaging that can eliminate autofluorescence for sustained signal emission after the excitation.