Cascade Amplifiers of Intracellular Reactive Oxygen Species Based on Mitochondria-Targeted Core-Shell ZnO-TPP@D/H Nanorods for Breast Cancer Therapy

The Multifaceted Functions of TRPV4 and Calcium Oscillations in Tissue Repair

The transient receptor potential vanilloid 4 (TRPV4) specifically functions as a mechanosensitive ion channel and is responsible for conveying changes in physical stimuli such as mechanical stress, osmotic pressure, and temperature. TRPV4 enables the entry of cation ions, particularly calcium ions, into the cell. Activation of TRPV4 channels initiates calcium oscillations, which trigger intracellular signaling pathways involved in a plethora of cellular processes, including tissue repair. Widely expressed throughout the body, TRPV4 can be activated by a wide array of physicochemical stimuli, thus contributing to sensory and physiological functions in multiple organs. This review focuses on how TRPV4 senses environmental cues and thereby initiates and maintains calcium oscillations, critical for responses to organ injury, tissue repair, and fibrosis. We provide a summary of TRPV4-induced calcium oscillations in distinct organ systems, along with the upstream and downstream signaling pathways involved. In addition, we delineate current animal and disease models supporting TRPV4 research and shed light on potential therapeutic targets for modulating TRPV4-induced calcium oscillation to promote tissue repair while reducing tissue fibrosis.

Illuminating the Brain: Advances and Perspectives in Optoelectronics for Neural Activity Monitoring and Modulation

Optogenetic modulation of brain neural activity that combines optical and electrical modes in a unitary neural system has recently gained robust momentum. Controlling illumination spatial coverage, designing light-activated modulators, and developing wireless light delivery and data transmission are crucial for maximizing the use of optical neuromodulation. To this end, biocompatible electrodes with enhanced optoelectrical performance, device integration for multiplexed addressing, wireless transmission, and multimodal operation in soft systems have been developed. This review provides an outlook for uniformly illuminating large brain areas while spatiotemporally imaging the neural responses upon optoelectrical stimulation with little artifacts. Representative concepts and important breakthroughs, such as head-mounted illumination, multiple implanted optical fibers, and micro-light-delivery devices, are discussed. Examples of techniques that incorporate electrophysiological monitoring and optoelectrical stimulation are presented. Challenges and perspectives are posed for further research efforts toward high-density optoelectrical neural interface modulation, with the potential for nonpharmacological neurological disease treatments and wireless optoelectrical stimulation.

ZnO Nanorods Create a Hypoxic State with Induction of HIF-1 and EPAS1, Autophagy, and Mitophagy in Cancer and Non-Cancer Cells

Nanomaterials are gaining increasing attention as innovative materials in medicine. Among nanomaterials, zinc oxide (ZnO) nanostructures are particularly appealing because of their opto-electrical, antimicrobial, and photochemical properties. Although ZnO is recognized as a safe material and the Zn ion (Zn²⁺) concentration is strictly regulated at a cellular and systemic level, different studies have demonstrated cellular toxicity of ZnO nanoparticles (ZnO-NPs) and ZnO nanorods (ZnO-NRs). Recently, ZnO-NP toxicity has been shown to depend on the intracellular accumulation of ROS, activation of autophagy and mitophagy, as well as stabilization and accumulation of hypoxia-inducible factor-1α (HIF-1α) protein. However, if the same pathway is also activated by ZnO-NRs and how non-cancer cells respond to ZnO-NR treatment, are still unknown. To answer to these questions, we treated epithelial HaCaT and breast cancer MCF-7 cells with different ZnO-NR concentrations. Our results showed that ZnO-NR treatments increased cell death through ROS accumulation, HIF-1α and endothelial PAS domain protein 1 (EPAS1) activation, and induction of autophagy and mitophagy in both cell lines. These results, while on one side, confirmed that ZnO-NRs can be used to reduce cancer growth, on the other side, raised some concerns on the activation of a hypoxic response in normal cells that, in the long run, could induce cellular transformation.

Advances in nuclei targeted delivery of nanoparticles for the management of cancer

A carrier is inserted into the appropriate organelles (nucleus) in successful medication transport, crucial to achieving very effective illness treatment. Cell-membrane targeting is the major focus of using nuclei to localize delivery. It has been demonstrated that high quantities of anticancer drugs can be injected directly into the nuclei of cancer cells, causing the cancer cells to die and increasing the effectiveness of chemotherapy. There are several effective ways to functionalize Nanoparticles (NPs), including changing their chemical makeup or attaching functional groups to their surface to increase their ability to target organelles. To cause tumor cells to apoptosis, released medicines must engage with molecular targets on particular organelles when their concentration is high enough. Targeted medication delivery studies will increasingly focus on organelle-specific delivery.

Hollow Nanomaterials in Advanced Drug Delivery Systems: From Single- to Multiple Shells

Hollow-structured nanomaterials (HSNMs) have attracted increased interest in biomedical fields, owing to their excellent potential as drug delivery systems (DDSs) for clinical applications. Among HSNMs, hollow multi-shelled structures (HoMSs) exhibit properties such as high loading capacity, sequential drug release, and multi-functionalized modification and represent a new class of nanoplatforms for clinical applications. The remarkable properties of HoMS-based DDS can simultaneously satisfy and enhance DDSs for delivering small molecular drugs (e.g., antibiotics, chemotherapy drugs, and imaging agents) and macromolecular drugs (e.g., protein/peptide- and nucleic acid-based drugs). First, the latest research advances in delivering small molecular drugs are summarized and highlight the inherent advantages of HoMS-based DDSs for small molecular drug targeting, combining continuous therapeutic drug delivery and theranostics to optimize the clinical benefit. Meanwhile, the macromolecular drugs DDSs are in the initial development stage and currently offer limited delivery modes. There is a growing need to analyze the deficiency of other HSNMs and integrate the advantages of HSNMs, providing solutions for the safe, stable, and cascade delivery of macromolecular drugs to meet vast treatment requirements. Therefore, the latest advances in HoMS-based DDSs are comprehensively reviewed, mainly focusing on the characteristics, research progress by drug category, and future research prospects.

Application Prospects of Triphenylphosphine-Based Mitochondria-Targeted Cancer Therapy

Cancer is one of the leading causes of death and the most important impediments to the efforts to increase life expectancy worldwide. Currently, chemotherapy is the main treatment for cancer, but it is often accompanied by side effects that affect normal tissues and organs. The search for new alternatives to chemotherapy has been a hot research topic in the field of antineoplastic medicine. Drugs targeting diseased tissues or cells can significantly improve the efficacy of drugs. Therefore, organelle-targeted antitumor drugs are being explored, such as mitochondria-targeted antitumor drugs. Mitochondria is the central site of cellular energy production and plays an important role in cell survival and death. Moreover, a large number of studies have shown a close association between mitochondrial metabolism and tumorigenesis and progression, making mitochondria a promising new target for cancer therapy. Combining mitochondrial targeting agents with drug molecules is an effective way of mitochondrial targeting. In addition, hyperpolarized tumor cell membranes and mitochondrial membrane potentially allow selective accumulation of mitochondria-targeted drugs. This enhances the direct killing of tumor cells by drug molecules while minimizing the potential toxicity to normal cells. In this review, we discuss the common pro-mitochondrial agents, the advantages of triphenylphosphine (TPP) in mitochondrial-targeted cancer therapy and systematically summarize various TPP-based mitochondria-targeting anticancer drugs.

Nanoscaled PAMAM Dendrimer Spacer Improved the Photothermal-Photodynamic Treatment Efficiency of Photosensitizer-Decorated Confeito-Like Gold Nanoparticles for Cancer Therapy

A critical factor in developing an efficient photosensitizer-gold nanoparticle (PS-AuNP) hybrid system with improved plasmonic photosensitization is to allocate a suitable space between AuNPs and PS. Poly(amidoamine) (PAMAM) dendrimer is selected as a spacer between the PS and confeito-like gold nanoparticles (confeito-AuNPs), providing the required distance (≈2.5-22.5 nm) for plasmon-enhanced singlet oxygen generation and heat production upon 638-nm laser irradiation and increase the cellular internalization of the nanoconjugates. The loading of the PS, tetrakis(4-carboxyphenyl) porphyrin (TCPP) and modified zinc phthalocyanine (ZnPc1) onto PAMAM-confeito-AuNPs demonstrate better in vitro cancer cell-killing efficacy, as the combined photothermal-photodynamic therapies (PTT-PDTs) outperforms the single treatment modalities (PTT or PDT alone). These PS-PAMAM-confeito-AuNPs also demonstrate higher phototoxicity than photosensitizers directly conjugated to confeito-AuNPs (TCPP-confeito-AuNPs and ZnPc1-confeito-AuNPs) against all breast cancer cell lines tested (MDA-MB-231, MCF7 and 4T1). In the in vivo studies, TCPP-PAMAM-confeito-AuNPs are biocompatible and exhibit a selective tumor accumulation effect, resulting in higher antitumor efficacy than free TCPP, PAMAM-confeito-AuNPs and TCPP-confeito-AuNPs. In vitro and in vivo evaluations confirm PAMAM effectiveness in facilitating cellular uptake, plasmon-enhanced singlet oxygen and heat generation. In summary, this study highlights the potential of integrating a PAMAM spacer in enhancing the plasmon effect-based photothermal-photodynamic anticancer treatment efficiency of PS-decorated confeito-AuNPs. This article is protected by copyright. All rights reserved.

Tumor-Associated Neutrophil Extracellular Traps Regulating Nanocarrier-Enhanced Inhibition of Malignant Tumor Growth and Distant Metastasis

Tumor-associated neutrophil extracellular traps (NETs) play a critical role in promoting tumor growth and assisting tumor metastasis. Herein, a smart nanocarrier (designated as mP-NPs-DNase/PTX) based on regulating tumor-associated NETs has been developed, which consists of a paclitaxel (PTX) prodrug nanoparticle core and a poly-l-lysine (PLL) conjugated with the matrix metalloproteinase 9 (MMP-9)-cleavable Tat-peptide-coupled deoxyribonuclease I (DNase I) shell. After accumulating at the site of the tumor tissue, the nanocarrier can release DNase I in response to MMP-9 to degrade the structure of NETs. Then, the remaining moiety can uptake the tumor cells via the mediation of exposed cell penetrating peptide, and the PTX prodrug nanoparticles will lyse in response to the high intracellular concentration of reduced glutathione to release PTX to exert a cytotoxic effect of tumor cells. Through in vitro and in vivo evaluations, it has been proven that mP-NPs-DNase/PTX could serve as potential NET-regulated nanocarrier for enhanced inhibition of malignant tumor growth and distant metastasis.

Application of Nano-Drug Delivery System Based on Cascade Technology in Cancer Treatment

In the current cancer treatment, various combination therapies have been widely used, such as photodynamic therapy (PDT) combined with chemokinetic therapy (CDT). However, due to the complexity of the tumor microenvironment (TME) and the limitations of treatment, the efficacy of current treatment options for some cancers is unsatisfactory. Nowadays, cascade technology has been used in cancer treatment and achieved good therapeutic effect. Cascade technology based on nanotechnology can trigger cascade reactions under specific tumor conditions to achieve precise positioning and controlled release, or amplify the efficacy of each drug to improve anticancer efficacy and reduce side effects. Compared with the traditional treatment, the application of cascade technology has achieved the controllability, specificity, and effectiveness of cancer treatment. This paper reviews the application of cascade technology in drug delivery, targeting, and release via nano-drug delivery systems in recent years, and introduces their application in reactive oxygen species (ROS)-induced cancer treatment. Finally, we briefly describe the current challenges and prospects of cascade technology in cancer treatment in the future.

Multifunctional ZnO@CuS nanoparticles cluster synergize chemotherapy and photothermal therapy for tumor metastasis

The poor drug delivery and unsatisfying therapeutic effects remain to be the primary challenges for cancer therapy. Nanosystem that combines multiple functions into a single platform is an ideal strategy. Here, a smart drug delivery nanoplatform (Z@C-D/P) based on ZnO@CuS nanoparticles, loaded with doxorubicin (DOX) and pirfenidone (PFD) was constructed. Importantly, the β-CD-DMA and PEG-DMA could be activated in the mild acidic tumor microenvironment, then the nanosystem underwent charge reversal and PFD release. PFD could inhibit cancer-associated fibroblasts (CAFs) activation and enhance tumor penetration. And the residual nanostructure ZnO@CuS could trigger cascade amplified ROS generation to induce tumor cell death. The photothermal effect further strengthened the anti-tumor efficacy. Finally, the nanosystem showed remarkable inhibition of tumor growth (89.7%) and lung metastasis. The innovatively designed nanosystem integrating chemotherapy and photothermal effect would provide a promising strategy in breast cancer therapy.

Low-intensity focused ultrasound-augmented Cascade chemodynamic therapy via boosting ROS generation

Fenton reaction-mediated chemodynamic therapy (CDT), which destroys tumor cells by converting H₂O₂ into cytotoxic hydroxyl radical (OH) and singlet oxygen (¹O₂) species, is a promising field. However, Fenton-based CDT is severely impaired by the inappropriate tumor environment associated with undesirable intratumoral acidity and insufficient H₂O₂ supply in tumor microenvironment (TME). Therefore, a strategy that can address these concerns is highly desired and beneficial for boosting such treatment. Herein, a magnetic nanoreactor system (denoted as poly (lactic-co-glycolic acid) (PLGA)-superparamagnetic iron oxide (SPIO)&vitamin C (Vc) was constructed with Vc in the core, SPIO on the shell, and PLGA as the building carrier. Upon low-intensity focused ultrasound irradiation, on-demand Vc release can locally decompose into H₂O₂, which can generate a favorable condition for facilitating SPIO-based Fenton-like reaction and result in continuous O₂ and OH/¹O₂ generation. The TME modulation-augmented CDT by this nanoreactor based on the reinforced Fenton reaction tremendously improved the antitumor outcomes, especially under increased accumulation contributed by magnetic targeting combined with enhanced permeability and retention effect. Moreover, the explosive production of oxygen can be monitored by real-time photoacoustic imaging, offering a noninvasive means to forecast the treatment efficacy. Therefore, this established microenvironment modulation strategy for augmenting Fenton reaction-based CDT paves a new avenue to realize highly efficient cancer theranostics.

Dual-Responsive and Deep-Penetrating Nanomicelles for Tumor Therapy via Extracellular Matrix Degradation and Oxidative Stress

Tumor microenvironment (TME), with complex composition, plays a vital role in the occurrence, development, and metastasis of tumors. TME becomes an important obstacle to the accessibility of nanotherapy, thus indicating the need to improve the functional design to overcome this challenge. In this study, we generate an intelligent nano-drug-delivery system (DOX@PssP-Hh NPs) with dual environmental response, which involves heparanase (HPSE) in TME and glutathione (GSH) in tumor cells. The nanosystem consists of a nanoskeleton formed by self-assembly of mPEG-ss-PEI and α-CD (PssP), chemotherapy drug doxorubicin (DOX) for enhancing antitumor efficacy, together with hyaluronidase (HAase), which is designed to degrade extracellular matrix to increase drug penetration, and an outer shell of heparin. Through the process of "responsive disintegration-remodeling tumor microenvironment-enhancing drug penetration-inducing oxidative stress", the semi-rotaxaneself-assembled nanomicelles were constructed to achieve the progressive function. DOX@PssP-Hh NPs with the size of 81.85 ± 1.85 nm exhibited satisfactory cytotoxicity (IC₅₀ = 0.80 ± 0.33 μg/mL). With the disulfide bond-mediated GSH depletion and DOX-mediated reactive oxygen species (ROS) production, treatment with DOX@PssP-Hh NPs prominently reduced glutathione peroxidase 4 (GPX4) level and would lead to enhanced oxidative stresses. Hyaluronic acid (HA), collagen I, and α-smooth muscle actin (α-SMA) were significantly reduced for TME remodulation. Moreover, the antitumor effect in vivo implied that DOX@PssP-Hh NPs could inhibit tumor growth effectively and reduce tumor interstitial fluid pressure (IFP) evidently. In conclusion, DOX@PssP-Hh NPs improved the penetration of drugs and exhibited enhanced antitumor efficacy.

Nanoplatform-based cascade engineering for cancer therapy

Various therapeutic techniques have been studied for treating cancer precisely and effectively, such as targeted drug delivery, phototherapy, tumor-specific catalytic therapy, and synergistic therapy, which, however, evoke numerous challenges due to the inherent limitations of these therapeutic modalities and intricate biological circumstances as well. With the remarkable advances of nanotechnology, nanoplatform-based cascade engineering, as an efficient and booming strategy, has been tactfully introduced to optimize these cancer therapies. Based on the designed nanoplatforms, pre-supposed cascade processes could be triggered under specific conditions to generate/deliver more therapeutic species or produce stronger tumoricidal effects inside tumors, aiming to achieve cancer therapy with increased anti-tumor efficacy and diminished side effects. In this review, the recent advances in nanoplatform-based cascade engineering for cancer therapy are summarized and discussed, with an emphasis on the design of smart nanoplatforms with unique structures, compositions and properties, and the implementation of specific cascade processes by means of endogenous tumor microenvironment (TME) resources and/or exogenous energy inputs. This fascinating strategy presents unprecedented potential in the enhancement of cancer therapies, and offers better controllability, specificity and effectiveness of therapeutic functions compared to the corresponding single components/functions. In the end, challenges and prospects of such a burgeoning strategy in the field of cancer therapy will be discussed, hopefully to facilitate its further development to meet the personalized treatment demands.

miR-31 Modulates Liver Cancer HepG2 Cell Apoptosis and Invasion via ROCK1/F-Actin Pathways

PURPOSE

Liver cancer is one of the most common malignant tumor in the world. miR-31 is downregulated in liver cancer and associated with tumor growth and metastasis. However, the underlying mechanism remains unclear.

METHODS

Cellular apoptosis was detected via MTT, TUNEL assay, LDH release and Annexin V/PI flow-cytometry analysis. Cellular migration and invasion were measured by the Transwell chamber assay. Mitochondrial functions were evaluated via mitochondrial membrane potential JC-1 staining and mPTP opening assessment. The mitophagy activity was examined via Western blots.

RESULTS

In the present study, our results confirm that miR-31 promotes apoptosis and inhibits proliferation and metastasis in liver cancer HepG2 cells. In vitro, miR-31 promotes HepG2 cell apoptosis through the mitochondrial pathway as indicated by mitochondrial potential reduction, increased mPTP opening time, cty-c release and imbalance of pro- and anti-apoptotic proteins. Furthermore, miR-31 reduces the energy generation by inhibiting mitochondrial respiratory function. At last, it is demonstrated that miR-31 triggers the mitochondrial damage via ROCK1/F-actin pathway. Inhibiting the ROCK1/F-actin pathway abolishes the effects of miR-31 mimic on mitochondrial injury, apoptosis, proliferation arrest and migration inhibition.

CONCLUSION

Our results reveal that miR-31 can inhibit HepG2 cell survival and metastasis by activating the ROCK1/F-actin pathway.

An energy-blocking nanoparticle decorated with anti-VEGF antibody to reverse chemotherapeutic drug resistance

Multi-drug resistance (MDR) of tumor cells has greatly hindered the therapeutic efficacy of chemotherapeutic drugs, resulting in chemotherapy failure, while overexpression of ATP-binding cassette (ABC) transporters in cell membranes is the leading cause of MDR. In this study, we reported novel self-assembled triphenylphosphine-quercetin-polyethylene glycol-monoclonal antibody nanoparticles (TQ-PEG-mAb NPs) for overcoming MDR primarily through mitochondrial damage to block ATP supply to ABC transporters both in vitro and in vivo. The doxorubicin (DOX)-loaded NPs (TQ/DOX-PEG-mAb) were composed of two drugs (TQ and DOX) and an outer shielding shell of the PEG-mAb conjugate. Besides, the outer shell could be acid-responsively detached to expose the positive charge of TQ inside the NPs to enhance cellular uptake. TQ was proved to effectively induce mitochondrial damage with increased ROS levels and depolarization of mitochondrial membrane potential (MMP), leading to prominently reduced ATP supply to ABC transporters. Moreover, the involvement of the anti-vascular endothelial growth factor (VEGF) mAb was not only for efficient targeting but also for combined therapy. Consequently, TQ/DOX-PEG-mAb showed that the internalized amount of DOX was largely improved while the efflux amount was dramatically inhibited on MCF-7/ADR cells, indicating excellent reversal of DOX resistance. Importantly, the growth of DOX-resistant breast tumors was significantly inhibited with no evident systemic toxicity. Therefore, the employment of TQ-PEG-mAb is believed to be a new approach to improve the efficacy of chemotherapeutic drugs in MDR tumors.

Evaluation of HOCl-generating anticancer agents by an ultrasensitive dual-mode fluorescent probe

Hypochlorous acid (HOCl), a reactive oxygen species (ROS), plays a crucial role in the process of pathogenic oxidative stress. Some powerful anticancer agents, such as elesclomol, specifically induce cancer cell apoptosis by increasing HOCl levels. However, sensitive tools to monitor subtle changes of biological HOCl in vivo are limited. To achieve this, we herein present rationally designed probes C1-C7 through introducing a bioorthogonal dimethylthiocarbamate receptor. All the probes were shown to sensitively and rapidly detect HOCl in the nanomolar/biologically relevant concentration range with fluorescence turn-on observed in their respective optical regions, resulting in a blue-to-red "fluorescence rainbow" and providing a broad selection of colors for imaging HOCl in vivo. Remarkably, probe C7 exhibited both a turn-on signal at biologically relevant concentrations (LOD1 = 18 nM) and a ratiometric response at the high risk pathogenic concentrations (LOD2 = 0.47 μM), which gives a higher reliability compared to a single signal and avoids cross-talk caused by the combined use of several probes. C7 was used to monitor the oxidative stress process induced by elesclomol in live cancer cells, and using this probe it was further discovered that an evodiamine derivative was capable of generating cancer-cell HOCl.

Intracellular Fenton reaction based on mitochondria-targeted copper(ii)–peptide complex for induced apoptosis

Intracellular Fenton reaction-based mitochondria-targeted copper(ii)–peptide complex and Asc is developed for cancer cell treatment.