A Pt(II) complex bearing N-heterocycle ring induced ferroptotic cell death in ovarian cancer.

Cisplatin is a widely used chemotherapeutic agent which interacts with DNA to form Pt-DNA adducts, leading to DNA double-strand breaks and apoptosis. Resistance is the major obstacle in the clinical application of cisplatin. A quinoline derivative based Pt(II) complex PtQ was synthesized and characterized. As an analogue of cisplatin, PtQ demonstrated a novel anticancer mechanism in ovarian cancer. PtQ caused excessive production of reactive oxygen species (ROS), which triggered ferroptotic cell death in ovarian cancer. Cystine/glutamate antiporter SLC7A11 and glutathione peroxidase 4 (GPX4) which alleviate lipid peroxidation were both downregulated in PtQ-treated SKOV3 cells. Furthermore, PtQ induced DNA single-strand breaks and suppressed the expression of single-strand breaks repair protein PARP1. Mechanism studies demonstrated that PtQ can hopefully bypass the signaling pathways mediated cisplatin resistance in ovarian cancer.

A monofunctional Pt(II) complex combats triple negative breast cancer by triggering lysosome-dependent cell death.

Monofunctional Pt(II) complexes with potent efficacy to overcome the drawbacks of current platinum drugs represent a promising therapeutic approach for triple negative breast cancer (TNBC). A heterocyclic-ligated monofunctional Pt(II) complex PtL with a unique action of mode was designed and investigated. PtL induced DNA single-strand breaks and caused genomic instability in TNBC cells. Mechanism studies demonstrated that PtL disrupted lysosomal acidity and function, which in turn triggered lysosome-dependent cell death. Furthermore, PtL showed convincing suppression in the tube forming and cell migratory abilities against the metastatic potential of TNBC cells. The synthesis and investigation of PtL revealed its potential value as an anti-TNBC drug and extended the family of monofunctional Pt(II) complexes.

A multiangle polarised imaging-based method for thin section segmentation.

The most crucial task of petroleum geology is to explore oil and gas reservoirs in the deep underground. As one of the analysis techniques in petroleum geological research, rock thin section identification method includes particle segmentation, which is one of the key steps. A conventional sandstone thin section image typically contains hundreds of mineral particles with blurred boundaries and complex microstructures inside the particles. Moreover, the complex lithology and low porosity of tight sandstone make traditional image segmentation methods unsuitable for solving the complex thin section segmentation problems. This paper combines petrology and image processing technologies. First, polarised sequence images are aligned, and then the images are transformed to the HSV colour space to extract pores. Second, particles are extracted according to their extinction characteristics. Last, a concavity and corner detection matching method is used to process the extracted particles, thereby completing the segmentation of sandstone thin section images. The experimental results show that our proposed method can more accurately fit the boundaries of mineral particles in sandstone images than existing image segmentation methods. Additionally, when applied in actual production scenarios, our method exhibits excellent performance, greatly improving thin section identification efficiency and significantly assisting experts in identification.

Naringin inhibits P2X4 receptor expression on satellite glial cells in the neonatal rat dorsal root ganglion.

Naringin inhibits inflammation and oxidative stress, the P2 purinoreceptor X4 receptor (P2X4R) is associated with glial cell activation and inflammation, the purpose of this study is to investigate the effects of naringin on P2X4 receptor expression on satellite glial cells (SGCs) and its possible mechanisms. ATP promoted the SGC activation and upregulated P2X4R expression; naringin inhibited SGC activation, decreased expression of P2X4R, P38 MAPK/ERK, and NF-κB, and reduced levels of Ca2+, TNF-α, and IL-1ß in SGCs in an ATP-containing environment. These findings suggest that naringin attenuates the ATP-induced SGC activation and reduces P2X4R expression via the Ca2+-P38 MAPK/ERK-NF-κB pathway.

A copper complex that combats triple negative breast cancer by restraining angiogenesis.

Angiogenesis and metastasis are major factors affecting the growth and invasion of triple negative breast cancer (TNBC). A phenanthroline copper(II) complex CPT8 modified with an alkyl chain-linked triphenylphosphonium group showed potent antiproliferative activity against a series of cancer cells including TNBC MDA-MB-231 cells. CPT8 induced mitophagy through activation of PINK1/Parkin and BNIP3 pathways in cancer cells due to damage to mitochondria. More importantly, CPT8 reduced the tube formation ability of human umbilical vein endothelial cells (HUVEC) through downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2). The anti-angiogenic potential of CPT8 was confirmed by decreased vascular endothelial growth factor (VEGF) and CD34 expression in HUVEC. Moreover, CPT8 suppressed the expression of vascular endothelial cadherin and matrix metalloproteinases MMP2 and MMP9, leading to the inhibition of vasculogenic mimicry formation. CPT8 also weakened the metastatic potential of MDA-MB-231 cells. Downregulation of Ki67 and CD34 expression indicates that CPT8 suppressed tumor proliferation and vascularization in vivo, thus providing a unique metal drug candidate for the treatment of TNBC.

BODIPY-Based Multifunctional Nanoparticles for Dual Mode Imaging-Guided Tumor Photothermal and Photodynamic Therapy.

Multifunctional nanoparticles integrating accurate multi-diagnosis and efficient therapy hold great prospects in tumor theranostics. However, it is still a challenging task to develop multifunctional nanoparticles for imaging-guided effective eradication of tumors. Herein, we developed a near-infrared (NIR) organic agent Aza/I-BDP by coupling 2,6-diiodo-dipyrromethene (2,6-diiodo-BODIPY) with aza-boron-dipyrromethene (Aza-BODIPY). Through encapsulating with an amphiphilic biocompatible copolymer DSPE-mPEG5000, well-distributed Aza/I-BDP nanoparticles (NPs) were developed, which exhibited high 1O2 generation, high photothermal conversion efficiency, and excellent photo-stability. Notably, coassembly of Aza/I-BDP and DSPE-mPEG5000 effectively inhibits H-aggregation of Aza/I-BDP in aqueous solution and enhances the brightness simultaneously up to 31-fold. More importantly, in vivo experiments demonstrated that Aza/I-BDP NPs might be used for NIR fluorescent and photoacoustic imaging-guided photodynamic and photothermal therapy.

Silencing P2X7R Alleviates Diabetic Neuropathic Pain Involving TRPV1 via PKCε/P38MAPK/NF-κB Signaling Pathway in Rats.

Transient receptor potential vanillic acid 1 (TRPV1) is an ion channel activated by heat and inflammatory factors involved in the development of various types of pain. The P2X7 receptor is in the P2X family and is associated with pain mediated by satellite glial cells. There might be some connection between the P2X7 receptor and TRPV1 in neuropathic pain in diabetic rats. A type 2 diabetic neuropathic pain rat model was induced using high glucose and high-fat diet for 4 weeks and low-dose streptozocin (35 mg/kg) intraperitoneal injection to destroy islet B cells. Male Sprague Dawley rats were administrated by intrathecal injection of P2X7 shRNA and p38 inhibitor, and we recorded abnormal mechanical and thermal pain and nociceptive hyperalgesia. One week later, the dorsal root ganglia from the L4-L6 segment of the spinal cord were harvested for subsequent experiments. We measured pro-inflammatory cytokines, examined the relationship between TRPV1 on neurons and P2X7 receptor on satellite glial cells by measuring protein and transcription levels of P2X7 receptor and TRPV1, and measured protein expression in the PKCε/P38 MAPK/NF-κB signaling pathway after intrathecal injection. P2X7 shRNA and p38 inhibitor relieved hyperalgesia in diabetic neuropathic pain rats and modulated inflammatory factors in vivo. P2X7 shRNA and P38 inhibitors significantly reduced TRPV1 expression by downregulating the PKCε/P38 MAPK/NF-κB signaling pathway and inflammatory factors in dorsal root ganglia. Intrathecal injection of P2X7 shRNA alleviates nociceptive reactions in rats with diabetic neuropathic pain involving TRPV1 via PKCε/P38 MAPK/NF-κB signaling pathway.

Platinum-Based Two-Photon Photosensitizer Responsive to NIR Light in Tumor Hypoxia Microenvironment.

Platinum-based photosensitizers are promising anticancer agents in photodynamic therapy. The cytotoxic effects primarily arise from the production of singlet oxygen and platination of DNA. However, their efficacy is limited by drug resistance and hypoxic tumor microenvironment. A naphthalimide-modified cyclometalated platinum(II) complex PtPAN [PA = N-(2-(diethylamino)ethyl)picolinamide, N = N-(2'-ethylhexyl)-4-ethynyl-1,8-naphthalimide] is designed to conquer these problems. PtPAN generates ROS efficiently under both normoxia and hypoxia. It does not interact with DNA and shows low cytotoxicity in the dark, while it kills tumor cells via ROS under near-infrared light irradiation; moreover, it inhibits tumor growth in mice at a low light dose with negligible side effects. PtPAN is the first reported platinum-based photosensitizer that is unreactive to DNA in the dark but highly cytotoxic upon near-infrared (NIR) irradiation for oxygen-independent photodynamic therapy. Owing to its two-photon excitation property (λ = 825 nm), PtPAN may be suitable for the treatment of deep solid tumors.

Catestatin enhances ATP-induced activation of glial cells mediated by purinergic receptor P2X4.

The activation of glial cells and its possible mechanism play an extremely important role in understanding the pathophysiological process of some clinical diseases, and catestatin (CST) is involved in regulating this activation. In this project, we found that CST could enhance the activation of satellite glial cells (SGCs) and microglial cells and that the expression of P2X4 was increased; the co-expression of the P2X4 receptor with glial fibrillary acidic protein (GFAP) and the P2X4 receptor with CD11b was also increased significantly in glial cells of the ATP + CST group, and TNF-α and IL-1ß also showed a rising trend; the expression of phosphorylated ERK1/2 was also increased in the ATP + CST group. In summary, we conclude that CST could enhance ATP-induced activation of SGCs and microglial cells mediated by the P2X4 receptor and that the ERK1/2 signaling pathway may be involved in this activation process.

The P2X7 Receptor Is Involved in Diabetic Neuropathic Pain Hypersensitivity Mediated by TRPV1 in the Rat Dorsal Root Ganglion.

The purinergic 2X7 (P2X7) receptor expressed in satellite glial cells (SGCs) is involved in the inflammatory response, and transient receptor potential vanilloid 1 (TRPV1) participates in the process of neurogenic inflammation, such as that in diabetic neuropathic pain (DNP) and peripheral neuralgia. The main purpose of this study was to explore the role of the P2X7 receptor in DNP hypersensitivity mediated by TRPV1 in the rat and its possible mechanism. A rat model of type 2 diabetes mellitus-related neuropathic pain (NPP) named the DNP rat model was established in this study. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) of DNP rats were increased after intrathecal injection of the P2X7 receptor antagonist A438079, and the mRNA and protein levels of TRPV1 in the dorsal root ganglion (DRG) were decreased in DNP rats treated with A438079 compared to untreated DNP rats; in addition, A438079 also decreased the phosphorylation of p38 and extracellular signal-regulated kinase 1/2 (ERK1/2) in the DNP group. Based on these results, the P2X7 receptor might be involved in DNP mediated by TRPV1.

Photoinduced synergistic cytotoxicity towards cancer cells via Ru(II) complexes.

Ru(ii) complexes have been recognized as excellent anticancer candidates. However, the poor cell uptake of these complexes has been the major obstacle in improving their anticancer efficacy. Along with the development of the knowledge on the anticancer nature of the Ru(ii) complexes, several strategies have been designed to increase the cellular accumulation of these complexes. Among them, the light-triggered drug uptake approach is most promising. In this study, a bioactive Ru(ii)-polypyridyl complex Ru-1 is constructed via incorporating a modified phenanthroline ligand into the enlarged conjugate structure. The modulation of the ligand makes Ru-1 powerful in generating singlet oxygen and effective in photodynamic therapeutic activity. Moreover, the cell uptake is improved during this photodynamic process and induces further chemotherapeutic effect, which act synergistically to enhance its anticancer activity. The photoinduced synergistic cytotoxicity of Ru-1 towards cancer cells offers an effective way to sensitize the antitumor activity of Ru(ii) complexes.

Femtosecond Laser-Assisted Top-Restricted Self-Growth Re-Entrant Structures on Shape Memory Polymer for Dynamic Pressure Resistance.

Bioinspired surface material with re-entrant texture has been proven effective in exhibiting good pressure resistance to droplets with low surface tension under static conditions. In this work, we combined femtosecond laser cutting with shape memory polymer (SMP) and tape to fabricate re-entrant micropillar arrays by proposing a top-restricted self-growth (TRSG) strategy. Our proposed TRSG strategy simplifies the fabrication process and improves the processing efficiency of the re-entrant structure-based surface material. The structural parameters of the re-entrant micropillar array (microdisk diameter D, center-to-center distance P, and height H) can be adjusted through our TRSG processing method. To better characterize the anti-infiltration ability of various re-entrant micropillars, we studied the dynamic process of ethylene glycol droplet deformation by applying external vertical vibration to the surface material. Three parameters (vibration mode, amplitude, and frequency) of the external excitation and structural parameters of the re-entrant micropillar array were systemically investigated. We found that the surface material had better dynamic pressure resistance when P and D of the re-entrant texture were 650 and 500 µm, respectively, after heating for 6 min. This work provides new insights into the preparation and characterization of the surface material, which may find potential applications in microdroplet manipulation, drug testing, and biological sensors.

A ratiometric fluorescent probe for imaging enzyme dependent hydrogen sulfide variation in the mitochondria and in living mice.

Developing a ratiometric H2S fluorescent probe with fast response is of great importance for studying the H2S physiology. Herein, two hemicyanine-based H2S probes were constructed; the one with a propanoic acid group (CouPa) showed poor sensitivity while the other one with the N,N-diethylpropionamide moiety (CouDE) exhibited distinctly improved performance. CouDE showed the ability to detect mitochondrial H2S level fluctuation, which was triggered by alteration of CBS enzyme activity. Moreover, endogenous H2S change in solid tumours was monitored using CouDE.

A novel luminescent Ir(iii) complex for dual mode imaging: synergistic response to hypoxia and acidity of the tumor microenvironment.

The early detection of cancer shows great promise for the control and prevention of cancer. For early detection, one of the challenges that still exists is searching for methods that can illuminate tumors with high sensitivity. Here, acidity and hypoxia, two typical features that exist universally in a solid tumor microenvironment, were focused on to attain synergistic imaging with an enhanced signal-to-noise ratio. This was realized using an iridium(iii) based optical probe (Ir-1) that could sense acidity and hypoxia simultaneously and synergistically. Through the synergistic sensing of acidic pH and hypoxia, stronger emission signals or larger lifetime changes can be obtained than if a single factor (acidity or hypoxia) is used to induce variations. Furthermore, its potential for biological applications was confirmed by employing Ir-1 for phosphorescence synergistic intensity and lifetime imaging of acidity and hypoxia in live monolayer cells and 3D multicellular spheroids.

Anticancer copper complex with nucleus, mitochondrion and cyclooxygenase-2 as multiple targets.

Copper complexes are hopeful anticancer drugs due to their multifacet biological properties and high biocompatibility. Inflammatory environment plays an important role in tumor progression and affects the body response to chemotherapeutic agents. A copper(II) complex CuLA with a phenanthroline derivative N-(1,10-phenanthrolin-5-yl)-nonanamide (L) and two aspirin anions (A) as the ligands was synthesized. CuLA effectively induces mitochondrial dysfunction and promotes early-apoptosis in SKOV-3 cells; moreover, it suppresses the expression of cyclooxygenase-2, a key enzyme involved in inflammatory response, in lipopolysaccharide stimulated RAW 264.7 cells. By contrast, the analogue complex CuL without aspirin ligand shows similar influences on cellular redox homeostasis and cell cycle progression but relatively low cytotoxic activity due to its mild effect on mitochondrial function; more importantly, it lacks inhibition to cyclooxygenase-2. The results demonstrate that CuLA inhibits cancer cells through dual pathways involving DNA damage and mitochondrial dysfunction. The introduction of aspirin not only enhances the antitumour efficacy but also reduces the inflammatory threat. Copper complexes with both antitumor and anti-inflammatory activities may represent a new type of multifunctional metal complexes in hope to be developed into novel metallodrugs.

Hypotoxic copper complexes with potent anti-metastatic and anti-angiogenic activities against cancer cells.

Tumor metastasis and angiogenesis are the major obstacles in anticancer therapy. A series of phenanthroline copper(ii) complexes with different alkyl chains (CPTn, n = 1, 4, 6, 8) are synthesized and characterized. Cellular uptake and cytotoxicity assays reveal that the complex with longer chain length exhibits higher cellular Cu accumulation and stronger inhibition against the cancer cells. Both lipophilicity and structure influence the cellular uptake and cytotoxicity of CPTn. CPT8 is the most potent complex in this series. In addition to its promising anticancer activity, CPT8 displays remarkable anti-metastatic properties by inhibiting the migratory and invasive ability of ovarian cancer cells. Furthermore, it shows excellent anti-angiogenic activity in tube formation and spheroid sprouting of human umbilical vein endothelial cells. The vasculogenic mimicry assay confirms that CPT8 can inhibit the vascular channel formation of aggressive mouse melanoma cells. The production of reactive oxygen species (ROS), the expression of matrix metalloprotease (MMP-2), and the character of tumor cells are implicated in the cytotoxicity of CPTn. CPT8 is a typical example that demonstrates the versatility of copper(ii) complexes for cancer therapy through multiple pathways.

Coumarin/BODIPY Hybridisation for Ratiometric Sensing of Intracellular Polarity Oscillation.

With different polarity responses, coumarin and 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) were hybridised to construct polarity fluorescent sensors, CBDP and iso-CBDP, to overcome the disadvantages of solvatochromic sensors in ratiometric polarity sensing. Only CBDP displayed an emission ratio (ICou /IBDP , coumarin to BODIPY emissions) that increased with an exponential dependence on medium relative permittivity over a wide polarity range (ϵr <57.9). This sensing ability of CBDP was not affected by medium pH; viscosity; and most intracellular species, especially reactive oxygen, nitrogen, and sulfur species. Apart from local cytoplasmic polarity quantification through lambda imaging, CBDP enables real-time ratiometric imaging for intracellular polarity oscillation induced by oxidative stimulation. Ratiometric polarity flow cytometry was developed, for the first time, with CBDP, which demonstrated that a high concentration H2 O2 induced cytoplasmic polarity enhancement, whereas pre-incubation with N-acetyl-l-cysteine inhibited this effect.

A New Approach to Sensitize Antitumor Monofunctional Platinum(II) Complexes via Short Time Photo-Irradiation.

Sensitizing the antitumor activity of monofunctional PtII complexes is a reliable approach to developing antitumor agents different from the classic Pt-based drugs. Considering the poor intracellular accumulation of monofunctional PtII complexes, in this study, the photosensitizing monofunctional PtII complex Pt-BA was derived from a weak BODIPY (boron-dipyrromethene)-derived photosensitizer BA, with the purpose to improve its antitumor cytotoxicity via enhancing its intracellular accumulation with a short time photo-irradiation. Photoinduced reactive oxygen species (ROS) determination indicated that the PtII center in Pt-BA is able to improve the photoinduced ROS production ability of BA, which makes Pt-BA a mild photosensitizer. Fluorescence imaging disclosed that dark incubation makes Pt-BA accumulate mainly on the surface of cell membrane, and the later short time photo-irradiation (5 min) promotes distinctly the intracellular accumulation of Pt-BA, which has been confirmed by inductively coupled plasma-mass spectrometry determination. Flow cytometric Annexin V-FITC assay indicated that the short time irradiation of Pt-BA induces in situ the cell membrane damage, which might finally enhance the intracellular accumulation of this monofunctional complex. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay confirmed that the short time photo-irradiation promotes distinctly the antitumor cytotoxicity of Pt-BA against MCF-7, SGC-7901, A549, and HeLa cell lines. The photopromoted antitumor activity of Pt-BA implies that modifying monofunctional PtII complex as a mild photosensitizer to promote its cell accumulation is a useful approach to sensitizing the antitumor activity of monofunctional PtII complex and renders the possibility of monofunctional PtII prodrugs for precise chemotherapy via only short time photoactivation.