Remote Manipulation of ROS-Sensitive Calcium Channel Using Near-Infrared-Responsive Conjugated Oligomer Nanoparticles for Enhanced Tumor Therapy In Vivo

Amplifying Ca2+ overload by engineered biomaterials for synergistic cancer therapy

Ca2+ overload is one of the most widely causes of inducing apoptosis, pyroptosis, immunogenic cell death, autophagy, paraptosis, necroptosis, and calcification of tumor cells, and has become the most valuable therapeutic strategy in the field of cancer treatment. Nevertheless, several challenges remain in translating Ca2+ overload-mediated therapeutic strategies into clinical applications, such as the precise control of Ca2+ dynamics, specificity of Ca2+ homeostasis dysregulation, as well as comprehensive mechanisms of Ca2+ regulation. Given this, we comprehensively reviewed the Ca2+-driven intracellular signaling pathways and the application of Ca2+-based biomaterials (such as CaCO3-, CaP-, CaO2-, CaSi-, CaF2-, and CaH2-) in mediating cancer diagnosis, treatment, and immunotherapy. Meanwhile, the latest researches on Ca2+ overload-mediated therapeutic strategies, as well as those combined with multiple-model therapies in mediating cancer immunotherapy are further highlighted. More importantly, the critical challenges and the future prospects of the Ca2+ overload-mediated therapeutic strategies are also discussed. By consolidating recent findings and identifying future research directions, this review aimed to advance the field of oncology therapy and contribute to the development of more effective and targeted treatment modalities.

Nanographene-Based Polymeric Nanoparticles as Near-Infrared Emissive Neuronal Tracers

Precise tracking of axonal transport is key to deciphering neuronal functions. To achieve long-term imaging at both ultrastructural and macroscopic resolutions, it is critical to develop fluorescent transport tracers with high photostability and biocompatibility. Herein, we report the investigation of nanographene (NG)-based polymeric nanoparticles (NPs) as near-infrared (NIR)-emissive neuronal tracers. Dibenzo[a,m]dinaphtho[3,2,1-ef:1',2',3'-hi]coronene (DBDNC) was employed as the NG, which exhibited a broad NIR emission with a maximum at 711 nm inside the NPs. DBDNC-NPs displayed high photostability and low cytotoxicity, enabling live tracing of retrograde axonal transport in mouse sensory neurons cultured in microfluidic chambers. We also elucidated how DBDNC-NPs undergo retrograde axonal transport following the endolysosomal pathway. This work provides a proof of concept for NIR-emissive, NG-based neuronal tracers with potential for applications in neurobiology.

Engineering a porphyrin COFs encapsulated by hyaluronic acid tumor-targeted nanoplatform for sequential chemo-photodynamic multimodal tumor therapy

Numerous barriers hinder the entry of drugs into cells, limiting the effectiveness of tumor pharmacotherapy. Effective penetration into tumor tissue and facilitated cellular uptake are crucial for the efficacy of nanotherapeutics. Photodynamic therapy (PDT) is a promising approach for tumor suppression. In this study, we developed a size-adjustable porphyrin-based covalent organic framework (COF), further modified with hyaluronic acid (HA), to sequentially deliver drugs for combined chemo-photodynamic tumor therapy. A larger COF (P-COF, approximately 500 nm) was loaded with the antifibrotic drug losartan (LST) to create LST/P-COF@HA (LCH), which accumulates at tumor sites. After injection, LCH releases LST, downregulating tumor extracellular matrix (ECM) component levels and decreasing collagen density, thus reducing tumor solid stress. Additionally, the reactive oxygen species (ROS) generated from LCH under 660 nm laser irradiation induce lipid peroxidation of cell membranes. Owing to its larger particle size, LCH primarily functions extracellularly, paving the way for subsequent treatments. Following intravenous administration, the smaller COF (p-COF, approximately 200 nm) loaded with doxorubicin (DOX) and modified with HA (DOX/p-COF@HA, DCH) readily enters cells in the altered microenvironment. Within tumor cells, ROS generated from DCH facilitates PDT, while the released DOX targets cancer cells via chemotherapy, triggered by disulfide bond cleavage in the presence of elevated glutathione (GSH) levels. This depletion of GSH further enhances the PDT effect. Leveraging the size-tunable properties of the porphyrin COF, this platform achieves a multifunctional delivery system that overcomes specific barriers at optimal times, leading to improved outcomes in chemo-photodynamic multimodal tumor therapy in vivo.

TRPA1-Related Diseases and Applications of Nanotherapy

Transient receptor potential (TRP) channels, first identified in Drosophila in 1969, are multifunctional ion channels expressed in various cell types. Structurally, TRP channels consist of six membrane segments and are classified into seven subfamilies. Transient receptor potential ankyrin 1 (TRPA1), the first member of the TRPA family, is a calcium ion affinity non-selective cation channel involved in sensory transduction and responds to odors, tastes, and chemicals. It also regulates temperature and responses to stimuli. Recent studies have linked TRPA1 to several disorders, including chronic pain, inflammatory diseases, allergies, and respiratory problems, owing to its activation by environmental toxins. Mutations in TRPA1 can affect the sensory nerves and microvasculature, potentially causing nerve pain and vascular problems. Understanding the function of TRPA1 is important for the development of treatments for these diseases. Recent developments in nanomedicines that target various ion channels, including TRPA1, have had a significant impact on disease treatment, providing innovative alternatives to traditional disease treatments by overcoming various adverse effects.

Nanohybrid-Based Redox Homeostasis Perturbators Escaped from Early Lysosomes toward Amplified Sensitization of Tumor Cells and Photothermally Maneuvered Pyroptosis Therapy

Reactive oxygen species (ROS) hold great potential in tumor pyroptosis therapy, yet they are still limited by short species lifespan and limited diffusion distance. Inducing cells into a metastable state and then applying external energy can effectively trigger pyroptosis, but systemic sensitization still faces challenges, such as limited ROS content, rapid decay, and short treatment windows. Herein, a nanohybrid-based redox homeostasis-perturbator system was designed that synergistically induce early lysosomal escape, autophagy inhibition, and redox perturbation functions to effectively sensitize cells to address these challenges. Specifically, weakly alkaline layered double hydroxide nanosheets (LDH NSs) with pH-responsive degradation properties enabled early lysosomal escape within 4 h, releasing poly(L-dopa) nanoparticles for inducing catechol-quinone redox cycling in the cytoplasm. The intracellular ROS levels were systematically rebounded by 3-4 times in tumor cells and lasted for over 4 h. Subsequently induced lysosomal stress and Ca2+ signaling activation resulted in severe mitochondrial dysfunction, as well as a perilous metastable state. Thereby, sequential near-infrared light was applied to trigger amplified stress through a local photothermal conversion. This led to sufficiently high levels of cleaved caspase-1 and GSDMD activation (2.5-2.8-fold increment) and subsequent pyroptosis response. In addition, OH- released by LDH elevated pH to alleviate the limitation of glutathione depletion by quinones at acidic pH and inhibit protective autophagy. Largely secreted inflammatory factors (2.5-5.6-fold increment), efficient maturation of dendritic cells, and further immune stimulation were boosted for tumor inhibition as a consequence. This study offers a new paradigm and insights into the synergy of internal systematic cellular sensitization and sequential external energy treatment to achieve tumor suppression through pyroptosis.

Targeting TRPs in autophagy regulation and human diseases

Transient receptor potential channels (TRPs) are widely recognized as a group of ion channels involved in various sensory perceptions, such as temperature, taste, pressure, and vision. While macroautophagy (hereafter referred to as autophagy) is primarily regulated by core machinery, the ion exchange mediated by TRPs between intracellular and extracellular compartments, as well as within organelles and the cytoplasm, plays a crucial role in autophagy regulation as an important signaling transduction mechanism. Moreover, certain TRPs can directly interact with autophagy regulatory proteins to participate in autophagy regulation. In this article, we provide an in-depth review of the current understanding of the regulatory mechanisms of autophagy, with a specific focus on TRPs. Furthermore, we highlight the potential prospects for drug development targeting TRPs in autophagy for the treatment of human diseases.

Nanotherapeutics targeting autophagy regulation for improved cancer therapy

The clinical efficacy of current cancer therapies falls short, and there is a pressing demand to integrate new targets with conventional therapies. Autophagy, a highly conserved self-degradation process, has received considerable attention as an emerging therapeutic target for cancer. With the rapid development of nanomedicine, nanomaterials have been widely utilized in cancer therapy due to their unrivaled delivery performance. Hence, considering the potential benefits of integrating autophagy and nanotechnology in cancer therapy, we outline the latest advances in autophagy-based nanotherapeutics. Based on a brief background related to autophagy and nanotherapeutics and their impact on tumor progression, the feasibility of autophagy-based nanotherapeutics for cancer treatment is demonstrated. Further, emerging nanotherapeutics developed to modulate autophagy are reviewed from the perspective of cell signaling pathways, including modulation of the mammalian target of rapamycin (mTOR) pathway, autophagy-related (ATG) and its complex expression, reactive oxygen species (ROS) and mitophagy, interference with autophagosome-lysosome fusion, and inhibition of hypoxia-mediated autophagy. In addition, combination therapies in which nano-autophagy modulation is combined with chemotherapy, phototherapy, and immunotherapy are also described. Finally, the prospects and challenges of autophagy-based nanotherapeutics for efficient cancer treatment are envisioned.

New Ca2+ based anticancer nanomaterials trigger multiple cell death targeting Ca2+ homeostasis for cancer therapy

Calcium ion (Ca2+) is a necessary element for human and Ca2+ homeostasis plays important roles in various cellular process and functions. Recent reaches have targeted on inducing Ca2+ overload (both intracellular and transcellular) for tumor therapy. With the development of nanotechnology, nanoplatform-mediated Ca2+ overload has been safe theranostic model for cancer therapy, and defined a special calcium overload-induced tumor cell death as "calcicoptosis". However, the underlying mechanism of calcicoptosis in cancer cells remains further identification. In this review, we summarized multiple cell death types due to Ca2+ overload that induced by novel anticancer nanomaterials in tumor cells, including apoptosis, autophagy, pyroptosis, and ferroptosis. We reviewed the roles of these anticancer nanomaterials on Ca2+ homeostasis, including transcellular Ca2+ influx and efflux, and intracellular Ca2+ change in the cytosolic and organelles, and connection of Ca2+ overload with other metal ions. This review provides the knowledge of these nano-anticancer materials-triggered calcicoptosis accompanied with multiple cell death by regulating Ca2+ homeostasis, which could not only enhance their efficiency and specificity, but also enlighten to design new cancer therapeutic strategies and biomedical applications.

Type-I Photodynamic Therapy Induced by Pt-Coordination of Type-II Photosensitizers into Supramolecular Complexes

Platinum supramolecular complexes based on photosensitizers have garnered great interest in photodynamic therapy (PDT) due to Pt (II) centers as chemotherapeutic agents to eliminate tumor cells completely, which greatly improve the antitumor efficacy of PDT. However, in comparison to precursor photosensitizer ligand, the formed platinum supramolecular complexes typically exhibit inferior outcomes in terms of reactive oxygen species (ROS) generation. How to boost ROS generation in the formed platinum supramolecular complexes for enhanced PDT is an enticing yet highly challenging task. Here we report a Pt-coordination-based dimeric photosensitizer complex (Cz-BTZ-Py)2Pt(OTf)2. It is found that comparing with photosensitizer ligand Cz-BTZ-Py, the formed supramolecular complex exhibit redshifts of absorption wavelength as well as enhanced ROS generation efficiency. Moreover, type-I ROS generation (O2⋅-) is produced in the formed platinum supramolecular complexes mainly due to a reduced energy gap ΔEST resulting from exciton coupling between two photosensitizer ligands. And type-I ROS (O2⋅-) generation significantly amplifies the photodynamic therapy (PDT) outcomes. In vitro evaluation shows excellent photochemotherapy performance of (Cz-BTZ-Py)2Pt(OTf)2 nanoparticles. We anticipate this work would provide a novel approach to design type-I photosensitizers for efficient PDT.

Nanoplatform-Mediated Autophagy Regulation and Combined Anti-Tumor Therapy for Resistant Tumors

The overall cancer incidence and death toll have been increasing worldwide. However, the conventional therapies have some obvious limitations, such as non-specific targeting, systemic toxic effects, especially the multidrug resistance (MDR) of tumors, in which, autophagy plays a vital role. Therefore, there is an urgent need for new treatments to reduce adverse reactions, improve the treatment efficacy and expand their therapeutic indications more effectively and accurately. Combination therapy based on autophagy regulators is a very feasible and important method to overcome tumor resistance and sensitize anti-tumor drugs. However, the less improved efficacy, more systemic toxicity and other problems limit its clinical application. Nanotechnology provides a good way to overcome this limitation. Co-delivery of autophagy regulators combined with anti-tumor drugs through nanoplatforms provides a good therapeutic strategy for the treatment of tumors, especially drug-resistant tumors. Notably, the nanomaterials with autophagy regulatory properties have broad therapeutic prospects as carrier platforms, especially in adjuvant therapy. However, further research is still necessary to overcome the difficulties such as the safety, biocompatibility, and side effects of nanomedicine. In addition, clinical research is also indispensable to confirm its application in tumor treatment.

NIR-II Regulation of Mitochondrial Potassium Channel with Dual-Targeted Conjugated Oligomer Nanoparticles for Efficient Cancer Theranostics In Vivo

Cell fate can be efficiently modulated by switching ion channels. However, the precise regulation of ion channels in cells, especially in specific organelles, remains challenging. Herein, biomimetic second near-infrared (NIR-II) responsive conjugated oligomer nanoparticles with dual-targeted properties are designed and prepared to modulate the ion channels of mitochondria to selectively kill malignant cells in vivo. Upon 1060 nm laser irradiation, the mitochondria-located nanoparticles photothermally release a specific ion inhibitor of the potassium channel via a temperature-sensitive liposome, thus altering the redox balance and pathways of mitochondria. NIR-II responsive nanoparticles can effectively regulate the potassium channels of mitochondria and fully suppress tumor growth. This work provides a new modality based on the NIR-II nanoplatform to regulate ion channels in specific organelles and proposes an effective therapeutic mechanism for malignant tumors.

Dual Activation of Calcium Channels Using Near-Infrared Responsive Conjugated Oligomer Nanoparticles for Precise Regulation of Blood Glucose Homeostasis

The rarity of efficient tools with spatiotemporal resolution and biocompatibility capabilities remains a major challenge for further progress and application of signaling manipulation. Herein, biomimetic conjugated oligomeric nanoparticles (CM-CONs) were developed to precisely modulate blood glucose homeostasis via the two-pronged activation of calcium channels. Under near-infrared (NIR) laser irradiation, CM-CONs efficiently generate local heat and reactive oxygen species (ROS), thereby simultaneously activating thermosensitive transient receptor potential V1 (TRPV1) and ROS-sensitive transient receptor potential A1 (TRPA1) calcium channels in small intestinal endocrine cells. The activation of the channels mediates inward calcium flow and then promotes glucagon-like peptide (GLP-1) secretion. Both in vitro and in vivo studies indicate that CM-CONs effectively regulate glucose homeostasis in diabetic model mice upon NIR light irradiation. This work develops a two-pronged attack strategy for accurately controlling blood glucose homeostasis, holding great prospects in the treatment for diabetes.

Cu single-atom catalyst-based flexible hydrogen peroxide electrochemical sensor with oxygen resistance for monitoring ROS bursts

The study of cellular responses linked to oxidative stress mechanisms is crucial in comprehending diverse physiological and pathological life processes, including mitochondrial dysfunction. Nonetheless, despite the interference of O2, the monitoring of ROS released from cells poses a challenging task. In this study, carbon-based copper single-atom catalysts (Cu SACs) were synthesized that exhibits excellent electrocatalytic performance for H2O2 reduction with an initial potential at 0.23 V and effectively avoids interference from O2. Based on this catalyst, a flexible and stretchable oxygen-tolerant sensor was constructed and applied to monitor the calcium ion-induced ROS burst in human umbilical vein endothelial cells (HUVECs) in a simulated physiological condition. This study effectively eradicates interference that may arise from the reduction of O2 and presents a dependable platform for real-time in situ monitoring of physiologically active molecules by utilizing H2O2 detection.

Calcium carbonate-actuated ion homeostasis perturbator for oxidative damage-augmented Ca2+/Mg2+ interference therapy

Ion homeostasis distortion through exogenous overload or underload of intracellular ion species has become an arresting therapeutic approach against malignant tumor. Nevertheless, treatment outcomes of such ion interference are always compromised by the intrinsic ion homeostasis maintenance systems in cancer cells. Herein, an ion homeostasis perturbator (CTC) is facilely designed by co-encapsulation of carvacrol (CAR) and meso-tetra-(4-carboxyphenyl)porphine (TCPP) into pH-sensitive nano-CaCO3, aiming to disrupt the self-defense mechanism during the process of ion imbalance. Upon the endocytosis of CTC into tumor cells, lysosomal acidity can render the decomposition of CaCO3, resulting in the instant Ca2+ overload and CO2 generation in cytoplasm. Simultaneously, CaCO3 disintegration triggers the release of CAR and TCPP, which are devoted to TRPM7 inhibition and sonosensitization, respectively. The malfunction of TRPM7 can impede the influx of Mg2+ and allow unrestricted influx of Ca2+ based on the antagonism relationship between Mg2+ and Ca2+, leading to an aggravated Ca2+/Mg2+ dyshomeostasis through ion channel deactivation. In another aspect, US-triggered cavitation can be significantly enhanced by the presence of inert CO2 microbubbles, further amplifying the generation of reactive oxygen species. Such oxidative damage-augmented Ca2+/Mg2+ interference therapy effectively impairs the mitochondrial function of tumor, which may provide useful insights in cancer therapy.

Dual-Pronged Attack: pH-Driven Membrane-Anchored NIR Dual-Type Nano-Photosensitizer Excites Immunogenic Pyroptosis and Sequester Immune Checkpoint for Enhanced Prostate Cancer Photo-Immunotherapy

Prostate cancer (PCa) is a frustrating immunogenic "cold" tumor and generally receives unsatisfied immunotherapy outcomes in the clinic. Pyroptosis is an excellent immunogenic cell death form that can effectively activate the antitumor immune response, promote cytotoxic T-lymphocyte infiltration, and convert tumors from "cold" to "hot." However, the in vivo application of pyroptosis drugs is seriously limited, and the upregulation of tumor PD-L1 caused by photo-immunotherapy further promotes immune escape. Herein, a new nano-photosensitizer (YBS-BMS NPs-RKC) with pH-response integrating immunogenic pyroptosis induction and immune checkpoint blockade is developed. The pH-responsive polymer equipped with the cell membrane anchoring peptide RKC is used as the carrier and further encapsulated with the near-infrared-activated semiconductor polymer photosensitizer YBS and a PD-1/PD-L1 complex small molecule inhibitor BMS-202. The pH-driven membrane-anchoring and pyroptosis activation of YBS-BMS NPs-RKC is clearly demonstrated. In vitro and in vivo studies have shown that this dual-pronged therapy stimulates a powerful antitumor immune response to suppress primary tumor progression and evokes long-term immune memory to inhibit tumor relapse and metastasis. This work provides an effective self-synergistic platform for PCa immunotherapy and a new idea for developing more biocompatible photo-controlled pyroptosis inducers.

Selenium-integrated conjugated oligomer nanoparticles with high photothermal conversion efficiency for NIR-II imaging-guided cancer phototheranostics in vivo

Second near-infrared (NIR-II) fluorescence imaging in the range of 1000-1700 nm has great prospects for in vivo imaging and theranostics monitoring. At present, few NIR-II probes with theranostics properties have been developed, especially the high-performance organic theranostics material remains underexploited. Herein, we demonstrate a selenium (Se)-tailoring method to develop high-efficient NIR-II imaging-guided material for in vivo cancer phototheranostics. Via Se-tailoring strategy, conjugated oligomer TPSe-based nanoparticles (TPSe NPs) achieve bright NIR-II emission up to 1400 nm and exhibit a relatively high photothermal conversion efficiency of 60% with good stability. Moreover, the TPSe NPs demonstrate their photothermal ablation of cancer cells in vitro and tumor in vivo with the guidance of NIR-II imaging. It is worth noting that the TPSe NPs have good biocompatibility without obvious side effects. Thus, this work provides new insight into the development of NIR-II theranostics agents.

The role of redox-mediated lysosomal dysfunction and therapeutic strategies

Redox homeostasis refers to the dynamic equilibrium between oxidant and reducing agent in the body which plays a crucial role in maintaining normal physiological activities of the body. The imbalance of redox homeostasis can lead to the development of various human diseases. Lysosomes regulate the degradation of cellular proteins and play an important role in influencing cell function and fate, and lysosomal dysfunction is closely associated with the development of various diseases. In addition, several studies have shown that redox homeostasis plays a direct or indirect role in regulating lysosomes. Therefore, this paper systematically reviews the role and mechanisms of redox homeostasis in the regulation of lysosomal function. Therapeutic strategies based on the regulation of redox exerted to disrupt or restore lysosomal function are further discussed. Uncovering the role of redox in the regulation of lysosomes helps to point new directions for the treatment of many human diseases.

Recent Progress in NIR-II Fluorescence Imaging-guided Drug Delivery for Cancer Theranostics

Fluorescence imaging in the second near-infrared window (NIR-II) has become a prevalent choice owing to its appealing advantages like deep penetration depth, low autofluorescence, decent spatiotemporal resolution, and a high signal-to-background ratio. This would expedite the innovation of NIR-II imaging-guided drug delivery (IGDD) paradigms for the improvement of the prognosis of patients with tumors. This work systematically reviews the recent progress of such NIR-II IGDD-mediated cancer therapeutics and collectively brings its essence to the readers. Special care has been taken to assess their performances based on their design approach, such as enhancing their drug loading and triggering release, designing intrinsic and extrinsic fluorophores, and/ or overcoming biological barriers. Besides, the state-of-the-art NIR-II IGDD platforms for different therapies like chemo-, photodynamic, photothermal, chemodynamic, immuno-, ion channel, gas-therapies, and multiple functions such as stimulus-responsive imaging and therapy, and monitoring of drug release and therapeutic response, have been updated. In addition, for boosting theranostic outcomes and clinical translation, the innovation directions of NIR-II IGDD platforms are summarized, including renal-clearable, biodegradable, sub-cellular targeting, and/or afterglow, chemiluminescence, X-ray excitable NIR-IGDD, and even cell therapy. This review will propel new directions for safe and efficient NIR-II fluorescence-mediated anticancer drug delivery.

Nanoparticles-mediated ion channels manipulation: From their membrane interactions to bioapplications

Ion channels are transmembrane proteins ubiquitously expressed in all cells that control various ions (e.g. Na⁺, K⁺, Ca²⁺ and Cl^- etc) crossing cellular plasma membrane, which play critical roles in physiological processes including regulating signal transduction, cell proliferation as well as excitatory cell excitation and conduction. Abnormal ion channel function is usually associated with dysfunctions and many diseases, such as neurodegenerative disorders, ophthalmic diseases, pulmonary diseases and even cancers. The precise regulation of ion channels not only helps to decipher physiological and pathological processes, but also is expected to become cutting-edge means for disease treatment. Recently, nanoparticles-mediated ion channel manipulation emerges as a highly promising way to meet the increasing requirements with respect to their simple, efficient, precise, spatiotemporally controllable and non-invasive regulation in biomedicine and other research frontiers. Thanks the advantages of their unique properties, nanoparticles can not only directly block the pore sites or kinetics of ion channels through their tiny size effect, and perturb active voltage-gated ion channel by their charged surface, but they can also act as antennas to conduct or enhance external physical stimuli to achieve spatiotemporal, precise and efficient regulation of various ion channel activities (e.g. light-, mechanical-, and temperature-gated ion channels etc). So far, nanoparticles-mediated ion channel regulation has shown potential prospects in many biomedical fields at the interfaces of neuro- and cardiovascular modulation, physiological function regeneration and tumor therapy et al. Towards such important fields, in this typical review, we specifically outline the latest studies of different types of ion channels and their activities relevant to the diseases. In addition, the different types of stimulation responsive nanoparticles, their interaction modes and targeting strategies towards the plasma membrane ion channels will be systematically summarized. More importantly, the ion channel regulatory methods mediated by functional nanoparticles and their bioapplications associated with physiological modulation and therapeutic development will be discussed. Last but not least, current challenges and future perspectives in this field will be covered as well.

In Vivo Fluorescence Imaging-Guided Development of Near-Infrared AIEgens

In vivo fluorescence imaging has received extensive attention due to its distinguished advantages of excellent biosafety, high sensitivity, dual temporal-spatial resolution, real-time monitoring ability, and non-invasiveness. Aggregation-induced emission luminogens (AIEgens) with near-infrared (NIR) absorption and emission wavelengths are ideal candidate for in vivo fluorescence imaging for their large Stokes shift, high brightness and superior photostability. NIR emissive AIEgens provide deep tissue penetration depth as well as low interference from tissue autofluorescence. Here in this review, we summarize the molecular engineering strategies for constructing NIR AIEgens with high performances, including extending π-conjugation system and strengthen donor (D)-acceptor (A) interactions. Then the encapsulation strategies for increasing water solubility and biocompatibility of these NIR AIEgens are highlighted. Finally, the challenges and prospect of fabricating NIR AIEgens for in vivo fluorescence imaging are also discussed. We hope this review would provide some guidelines for further exploration of new NIR AIEgens.

Silver nanoparticles potentiate antitumor and oxidant actions of cisplatin via the stimulation of TRPM2 channel in glioblastoma tumor cells

We investigated the effects of silver nanoparticle (AgNP) and cisplatin (CiSP) exposure via the activation of TRPM2 cation channels in glioblastoma (DBTRG-05MG) cell line. The cells were divided into four groups as control, AgNPs (100 μg/ml for 48 h), CiSP (25 μM for 24 h), and CiSP + AgNPs. We found that the cytotoxic, oxidant and apoptotic actions of CiSP were further stimulated through the activation of TRPM2 (via ADP-ribose and H₂O₂) in the cells by the treatment of AgNPs. The actions were decreased in the cells by the treatments of TRPM2 antagonists (ACA and 2APB). The apoptotic actions of AgNPs were induced by the stimulation of propidium iodide positive DBTRG-05MG rate, caspase -3, caspase -8, and caspase -9 activations, although their oxidant actions were acted by the increase of mitochondrial membrane depolarization, lipid peroxidation, mitochondrial oxygen free radicals (ROS), and cytosolic ROS, but the decrease of total antioxidant status, glutathione, and glutathione peroxidase. The accumulation of cytosolic free Ca²⁺ and Zn²⁺ into mitochondria via the activation of TRPM2 current density and activity accelerated oxidant and apoptotic actions of AgNPs in the cells. We found that the combination of AgNPs and CiSP was synergistic via the stimulation of TRPM2 for treatment of DBTRG-05MG cells. The combination of AgNPs and CiSP showed a favorable action via the stimulation of TRPM2 in the treatment of glioblastoma tumor cells.

Fluorination Enhances NIR-II Emission and Photothermal Conversion Efficiency of Phototheranostic Agents for Imaging-Guided Cancer Therapy

Phototheranostics with second near-infrared (NIR-II) imaging and photothermal effect have become a burgeoning biotechnology for tumor diagnosis and precise treatment. As important parameters of phototheranostic agents (PTAs), fluorescence quantum yield (QY) and photothermal conversion efficiency (PCE) are usually considered as a pair of contradictions that is difficult to be simultaneously enhanced. Herein, a fluorination strategy for designing A-D-A type PTAs with synchronously improved QY and PCE is proposed. Experimental results show that the molar extinction coefficient (ε), NIR-II QY, and PCE of all fluorinated PTAs nanoparticles (NPs) are definitely improved compared with the chlorinated counterparts. Theoretical calculation results demonstrate that fluorination can maximize the electrostatic potential difference by virtue of the high electronegativity of fluorine, which may increase intra/intermolecular D-A interactions, tighten molecule packing, and further promote the increase of ε, ultimately leading to simultaneously enhanced QY and PCE. In these PTA NPs, FY6-NPs display NIR-II emission extended to 1400 nm with the highest NIR-II QY (4.2%) and PCE (80%). These features make FY6-NPs perform well in high-resolution imaging of vasculature and NIR-II imaging-guided photothermal therapy (PTT) of tumors. This study develops a valuable guideline for constructing NIR-II organic PTAs with high performance.