Repurposing Erythrocytes as a "Photoactivatable Bomb": A General Strategy for Site-Specific Drug Release in Blood Vessels.

Tumor vasculature has long been considered as an extremely valuable therapeutic target for cancer therapy, but how to realize controlled and site-specific drug release in tumor blood vessels remains a huge challenge. Despite the widespread use of nanomaterials in constructing drug delivery systems, they are suboptimal in principle for meeting this demand due to their easy blood cell adsorption/internalization and short lifetime in the systemic circulation. Here, natural red blood cells (RBCs) are repurposed as a remote-controllable drug vehicle, which retains RBC's morphology and vessel-specific biodistribution pattern, by installing photoactivatable molecular triggers on the RBC membrane via covalent conjugation with a finely tuned modification density. The molecular triggers can burst the RBC vehicle under short and mild laser irradiation, leading to a complete and site-specific release of its payloads. This cell-based vehicle is generalized by loading different therapeutic agents including macromolecular thrombin, a blood clotting-inducing enzyme, and a small-molecule hypoxia-activatable chemodrug, tirapazamine. In vivo results demonstrate that the repurposed "anticancer RBCs" exhibit long-term stability in systemic circulation but, when tumors receive laser irradiation, precisely releases their cargoes in tumor vessels for thrombosis-induced starvation therapy and local deoxygenation-enhanced chemotherapy. This study proposes a general strategy for blood vessel-specific drug delivery.

DOX-loaded silver nanotriangles and photothermal therapy exert a synergistic antibreast cancer effect via ROS/ERK1/2 signaling pathway.

The combination of multiple therapies has been proved to be more effective than a single therapy for many cancers. This study aimed to investigate the synergistic antibreast cancer effect of doxorubicin-loaded silver nanotriangles (DOX-AgNTs) combined with near-infrared (NIR) irradiation and explore the underlying mechanism. AgNTs were prepared by a chemical method and DOX was loaded via electrostatic adsorption. Characterization was performed by transmission electron microscopy, ultraviolet-visible spectroscopy and dynamic light scattering. The viability of MDA-MB-231 cells was detected by using MTT assay to evaluate the synergistic anticancer effect of DOX-AgNTs combined with NIR irradiation. The intracellular reactive oxygen species (ROS) level and cell apoptosis were analyzed by flow cytometry. Mitochondrial membrane potential (MMP) was measured with fluorescence microscopy. The mechanism was further investigated with ROS scavenger N-acetylcysteine and specific inhibitors of extracellular signal-regulated kinase 1/2 (ERK1/2), C-jun N-terminal kinase and p38 pathways. Characterization results revealed that the prepared AgNTs were mostly triangular and the mean edge length was about 126 nm. The combination of DOX-AgNTs and NIR exhibited a superior synergistic anticancer effect over single DOX-AgNTs or photothermal therapy (PTT). N-acetylcysteine and ERK1/2 inhibitor U0126 were found to significantly rescue the decreased cell viability, declined MMP and increased apoptosis induced by the combined treatment. Our results suggested that DOX-AgNTs combined with PTT performed a synergistic antibreast cancer effect. The synergy might be closely associated with the excessive production of ROS, changed MMP and the activation of ERK1/2 signaling pathway. These findings might provide a new perspective for the development of breast cancer treatments with excellent efficacy.

Application of silver nanotriangles as a novel contrast agent in tumor computed tomography imaging.

This study aimed to prepare chitosan-coated silver nanotriangles (AgNTs) and assess their computed tomography (CT) contrast property byin vitroandin vivoexperiments. AgNTs with a range of sizes were synthesized by a seed-based growth method, and subsequently characterized by transmission electron microscopy (TEM), ultraviolet-visible absorption spectroscopy and dynamic light scattering. The x-ray attenuation capability of all prepared AgNTs was evaluated using micro CT. The CT contrast effect of AgNTs with the highest x-ray attenuation coefficient was investigated in MDA-MB-231 breast cancer cells and a mouse model of breast cancer. The TEM results displayed that all synthesized AgNTs were triangular in shape and their mean edge lengths ranged from 60 to 149 nm. All AgNTs tested exhibited stronger x-ray attenuation capability than iohexol at the same mass concentration of the active elements, and the larger the AgNTs size, the higher the x-ray attenuation coefficient. AgNTs with the largest size were selected for further research, due to their strongest x-ray attenuation capability and best biocompatibility. The attenuation coefficient of breast cancer cells treated with AgNTs increased in a particle concentration-dependent manner.In vivoCT imaging showed that the contrast of the tumor injected with AgNTs was significantly enhanced. These findings indicated that AgNTs could be a promising candidate for highly efficient tumor CT contrast agents.

Increasing the accumulation of aptamer AS1411 and verapamil conjugated silver nanoparticles in tumor cells to enhance the radiosensitivity of glioma.

Radioresistance significantly decreases the efficacy of radiotherapy, which can ultimately lead to tumor recurrence and metastasis. As a novel type of nano-radiosensitizer, silver nanoparticles (AgNPs) have shown promising radiosensitizing properties in the radiotherapy of glioma, but their ability to efficiently enter and accumulate in tumor cells needs to be improved. In the current study, AS1411 and verapamil (VRP) conjugated bovine serum albumin (BSA) coated AgNPs (AgNPs@BSA-AS-VRP) were synthesized and characterized. Dark-field imaging and inductively coupled plasma mass spectrometry were applied to investigate the accumulation of AgNPs@BSA-AS and AgNPs@BSA-AS-VRP mixed in different ratios in U251 glioma cells. To assess the influences of 19:1 mixed AgNPs@BSA-AS and AgNPs@BSA-AS-VRP on the P-glycoprotein (P-gp) efflux activity, rhodamine 123 accumulation assay was carried out. Colony formation assay and tumor-bearing nude mice model were employed to examine the radiosensitizing potential of 19:1 mixed AgNPs@BSA-AS and AgNPs@BSA-AS-VRP. Thioredoxin Reductase (TrxR) Assay Kit was used to detect the TrxR activity in cells treated with different functionally modified AgNPs. Characterization results revealed that AgNPs@BSA-AS-VRP were successfully constructed. When AgNPs@BSA-AS and AgNPs@BSA-AS-VRP were mixed in a ratio of 19:1, the amount of intracellular nanoparticles increased greatly through AS1411-mediated active targeting and inhibition of P-gp activity. In vitro and in vivo experiments clearly showed that the radiosensitization efficacy of 19:1 mixed AgNPs@BSA-AS and AgNPs@BSA-AS-VRP was much stronger than that of AgNPs@BSA and AgNPs@BSA-AS. It was also found that 19:1 mixed AgNPs@BSA-AS and AgNPs@BSA-AS-VRP significantly inhibited intracellular TrxR activity. These results indicate that 19:1 mixed AgNPs@BSA-AS and AgNPs@BSA-AS-VRP can effectively accumulate in tumor cells and have great potential as high-efficiency nano-radiosensitizers in the radiotherapy of glioma.

Chitosan oligosaccharide decorated liposomes combined with TH302 for photodynamic therapy in triple negative breast cancer.

BACKGROUND: Triple negative breast cancer (TNBC) is an aggressive tumor with extremely high mortality that results from its lack of effective therapeutic targets. As an adhesion molecule related to tumorigenesis and tumor metastasis, cluster of differentiation-44 (also known as CD44) is overexpressed in TNBC. Moreover, CD44 can be effectively targeted by a specific hyaluronic acid analog, namely, chitosan oligosaccharide (CO). In this study, a CO-coated liposome was designed, with Photochlor (HPPH) as the 660 nm light mediated photosensitizer and evofosfamide (also known as TH302) as the hypoxia-activated prodrug. The obtained liposomes can help diagnose TNBC by fluorescence imaging and produce antitumor therapy by synergetic photodynamic therapy (PDT) and chemotherapy. RESULTS: Compared with the nontargeted liposomes, the targeted liposomes exhibited good biocompatibility and targeting capability in vitro; in vivo, the targeted liposomes exhibited much better fluorescence imaging capability. Additionally, liposomes loaded with HPPH and TH302 showed significantly better antitumor effects than the other monotherapy groups both in vitro and in vivo. CONCLUSION: The impressive synergistic antitumor effects, together with the superior fluorescence imaging capability, good biocompatibility and minor side effects confers the liposomes with potential for future translational research in the diagnosis and CD44-overexpressing cancer therapy, especially TNBC.

Palladium Nanosheets as Safe Radiosensitizers for Radiotherapy.

Many noble metal-based nanoparticles have emerged for applications in cancer radiotherapy in recent years, but few investigations have been carried out for palladium nanoparticles. Herein, palladium nanosheets (Pd NSs), which possess a sheetlike morphology with a diameter of ∼14 nm and a thickness of ∼2 nm, were utilized as a sensitizer to improve the performance of radiotherapy. It was found that Pd NSs alone did not decrease the cell viability after treatment for as long as 130 h, suggesting the excellent cytocompatibility of the nanoagents. However, the viability of cancer cells treated with X-ray irradiation became lower, and the viability became even lower if the cells were co-treated with X-ray and Pd NSs, indicating the radiosensitization effect of Pd NSs. Additionally, compared with X-ray irradiation, the combined treatment of Pd NSs and X-ray irradiation induced the generation of more DNA double-stranded breaks and reactive oxygen species within cancer cells, which eventually caused elevated cell apoptosis. Moreover, in vivo experiments also verified the radiosensitization effect and the favorable biocompatibility of Pd NSs, indicating their potential for acquiring satisfactory in vivo radiotherapeutic effect at lower X-ray doses. It is believed that the present research will open new avenues for the application of noble metal-based nanoparticles in radiosensitization.

Effect of graphene oxide exposure on intestinal Wnt signaling in nematode Caenorhabditis elegans.

Exposure to engineered nanomaterials (ENMs), such as graphene oxide (GO), can potentially induce the response of various molecular signaling pathways, which can mediate the protective function or the toxicity induction. Wnt signaling pathway is conserved evolutionarily in organisms. Using Caenorhabditis elegans as an in vivo assay model, we investigated the effect of GO exposure on intestinal Wnt signaling. In the intestine, GO exposure dysregulated Frizzled receptor MOM-5, Disheveled protein DSH-2, GSK-3 (a component of APC complex), and two ß-catenin proteins (BAR-1 and HMP-2), which mediated the induction of GO toxicity. In GO exposed nematodes, a Hox protein EGL-5 acted as a downstream target of BAR-1, and fatty acid transport ACS-22 acted as a downstream target of HMP-2. Functional analysis on HMP-2 and ACS-22 suggested that the dysregulation of these two proteins provides an important basis for the observed deficit in functional state of intestinal barrier. Our results imply the association of dysregulation in physiological and functional states of intestinal barrier with toxicity induction of GO in organisms.

Enhanced fluorescence of gold nanoclusters composed of HAuCl4 and histidine by glutathione: glutathione detection and selective cancer cell imaging.

Glutathione (GSH) can significantly and selectively enhance the fluorescence intensity of Au nanoclusters (NCs) prepared by blending HAuCl4 and histidine in solution. The quantum yield of the Au NCs after adding GSH can reach above 10%. Besides, GSH capping shifts the excitation peak of Au NCs from ultraviolet (386 nm) to visible light (414 nm) and improves the stability of the Au NCs. The cytotoxicities of the Au NCs with and without GSH for normal lung cells (ATII) and cancerous lung cells (A549) are evaluated. The GSH-capped Au NCs have much less cytotoxicity to both normal and cancer cells, as compared to those without GSH. For Au NCs without GSH, less cytotoxicity is observed in cancer cells than in normal cells. In addtion, the Au NCs can selectively detect GSH over cysteine and homocysteine, the two biothiols which commonly exist in cells that can seriously affect GSH detection. Most importantly, Au NCs without GSH can selectively image the cancer cells, especially for the liver cancer cells whose GSH content is much higher than other cell types. This property makes the Au NCs a powerful probe to distinguish cancer cells from normal cells.

Exposure to silver nanoparticles does not affect cognitive outcome or hippocampal neurogenesis in adult mice.

Due to the unique antimicrobial and many other broad spectrum biotechnological advantages, silver nanoparticles (Ag-NPs) are widely used in biomedical and general applications. However, the current knowledge about the impact of Ag-NPs on the central nervous system is extremely limited. To assess whether Ag-NPs influence spatial cognition and adult hippocampal neurogenesis, male ICR mice received intraperitoneal administration of Ag-NPs (10, 25, and 50 mg/kg body weight) or vehicle every day for 7 days. At the end of this time period, Morris water maze test was performed for the spatial learning and memory. Subsequently, mice were injected with bromodeoxyuridine and sacrificed 1 day or 28 days after the last injection in order to evaluate cell proliferation, survival and differentiation in the hippocampus. Results showed that compared with the control group, both reference memory and working memory were not impaired in Ag-NPs exposed groups. In addition, no differences were observed in hippocampal progenitor proliferation, new born cell survival or differentiation. These data reveal that exposure to Ag-NPs does not affect spatial cognition or hippocampal neurogenesis in mice.

AS1411-conjugated doxorubicin-loaded silver nanotriangles for targeted chemo-photothermal therapy of breast cancer.

Background: Combination therapy has attracted tremendous interest for its great potential in treating cancers. Materials & methods: Based on chitosan-coated silver nanotriangles, polyethylene glycol, AS1411 aptamer and doxorubicin, a multifunctional nanocomposite (AS1411-DOX-AgNTs) was constructed and characterized. Then the photothermal properties, ability to target breast cancer cells and anti-breast cancer effect of AS1411-DOX-AgNTs were evaluated. Results: AS1411-DOX-AgNTs were successfully fabricated and showed excellent photothermal conversion efficiency, breast cancer cell and tumor targeting ability. Compared with single treatments, the combination of AS1411-DOX-AgNTs with near-infrared irradiation possessed the strongest anti-breast cancer effect in vitro and in vivo. Conclusion: AS1411-DOX-AgNTs hold great potential in targeted DOX delivery and combined chemo-photothermal therapy for breast cancer.

This article focuses on nanomaterials, nanomedicine and photothermal therapy (PTT) to treat breast cancer. Nanomaterials refer to materials with at least one dimension in nanometer size (1­100 nm) or materials composed as basic units in a 3D space. Nanomedicine is the application of nanomaterials in medicine. Nanoparticles can deliver drugs to areas that are difficult for the drugs themselves to reach. PTT is a noninvasive tumor therapy that uses photothermal conversion agents to convert light energy into heat energy to kill tumor cells under the irradiation of external near-infrared (NIR) light. In recent years, combination therapy for cancers has drawn more and more attention. In the current study, we investigated the in vitro and in vivo anticancer effects of silver nanocomposites combined with chemotherapy and PTT. The prepared silver nanocomposites showed excellent physicochemical properties and possessed good anti-breast cancer efficacy combined with PTT and chemotherapy drug in vitro and in vivo. The results of this study demonstrated that these prepared silver nanocomposites had exceptional anti-breast cancer effects in combination with PTT and could be promising drug-loaded photothermal conversion agents.

Exposure to mercury causes formation of male-specific structural deficits by inducing oxidative damage in nematodes.

Metal exposure causes reproductive damage in hermaphrodite nematodes, but effects of metals on male development are unclear. We here investigated the effects of mercury chloride exposure on development of males. Hg exposure severely increased the percentage of abnormal males, disrupted the development of male-specific structures, and caused high reactive oxygen species (ROS) production in male tails. Pre-treatment with antioxidant (vitamin E) protected the nematodes against toxicity from Hg exposure on development of male-specific structures. The ROS production in tails was closely correlated with formation of abnormal male-specific structures in males induced by Hg exposure. Moreover, mutations of clk-1, encoding ortholog of COQ7/CAT5, and daf-2, encoding an insulin/IGF receptor, functioned in two different pathways to suppress the formation of deficits in development of male-specific structures. Thus, three different lines of evidence support our conclusion that HgCl(2) causes male structure-specific teratogenesis via production of oxidative stress.

Inhibition of ROS elevation and damage to mitochondrial function prevents lead-induced neurotoxic effects on structures and functions of AFD neurons in Caenorhabditis elegans.

Here we investigated the possible roles of oxidative stress in the formation of decreased thermotaxis to cultivation temperature in lead (Pb)-exposed nematodes Caenorhabditis elagans. Exposure to Pb at the examined concentrations decreased thermotaxis behaviors, and induced severe deficits in the structural properties of AFD sensory neurons. Meanwhile, Pb exposure caused the induction of severe oxidative damage, reactive oxygen species (ROS) production, and mitochondrial dysfunction in young adults. Moreover, pre-treatment with the antioxidants dimethyl sulfoxide (DMSO), ascorbate and N-acetyl-L-cysteine (NAC), used to inhibit both the ROS elevation and the mitochondrial dysfunction caused by Pb exposure, at the L2-larval stage prevented the induction of oxidative damage and the formation of severe deficits in thermotaxis and structural properties of AFD sensory neurons in Pb-exposed young adults. Therefore, the formation of oxidative stress caused by Pb exposure may be due to both the induction of ROS elevation and damage to mitochondrial function, and oxidative stress may play a key role in inducing the neurotoxic effects on the structures and function of AFD sensory neurons in Pb-exposed nematodes.

GMT8 aptamer conjugated PEGylated Ag@Au core-shell nanoparticles as a novel radiosensitizer for targeted radiotherapy of glioma.

Radiotherapy is one of the main treatment modalities for glioma, but the therapeutic efficacy is often limited by the radioresistance of tumor cells. The radiosensitization effects of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) on tumors have been confirmed by previous studies. To enhance the specific killing effect of irradiation on tumor cells, targeted modification of radiosensitizers is urgently needed. Herein, we developed polyethylene glycol (PEG)-coated Ag@Au core-shell nanoparticles (PSGNPs) modified with GMT8 aptamer (GSGNPs) and evaluated their radiosensitization effects on glioma cells through in vivo and in vitro experiments. Transmission electron microscope image showed that the prepared PSGNPs had a spherical core-shell structure with an average size of 11 nm. The ultraviolet-visible absorption spectra and Fourier transform infrared spectra displayed that GMT8 was successfully conjugated to PSGNPs. The results of dark-field imaging revealed that the targeting ability of GSGNPs to U87 glioma cells was much better than that to normal human microvascular endothelial cells. Additionally, it was also found that the endocytic pathways of GSGNPs mainly involved clathrin-mediated endocytosis and macropinocytosis. The sensitization enhancement ratio of GSGNPs was calculated to be 1.62, which was higher than that of PSGNPs. In vivo imaging results showed that GSGNPs exhibited good tumor targeting and retention capabilities, and the fluorescence intensity ratio of Cy5-GSGNPs to Cy5-PSGNPs reached a peak at 4 h after injection. More importantly, the median survival time of mice bearing U87 glioma was significantly prolonged after intravenous administration of GSGNPs combined with radiotherapy. This work demonstrated that GSGNPs could be used as an effective nano-radiosensitizer for targeted radiotherapy of glioma.

The effect of AS1411 surface density on the tumor targeting properties of PEGylated silver nanotriangles.

Aim: To determine the optimal AS1411 density on polyethylene glycol (PEG)ylated silver nanotriangles (PNTs) for targeting breast cancer cells. Methods: PNTs modified with different AS1411 densities (ANTs) were constructed, characterized and evaluated for their targeting properties in breast cancer cells and a mouse model of breast cancer. Results: AS1411 was successfully conjugated to PNTs. The accumulation and cellular uptake of 10-ANTs were the highest. 10-ANTs plus near-IR laser irradiation displayed the greatest inhibitory effect on cell viability. However, 5-ANTs had the highest accumulation in tumor tissues. When combined with NIR laser, 5-ANTs exhibited the best in vivo photothermal therapy effect. Conclusion: The optimal AS1411 densities at the cellular and animal levels were 10% and 5%, respectively.

Sustained delivery of gemcitabine via in situ injectable mussel-inspired hydrogels for the local therapy of pancreatic cancer.

The issue of pervasively enhanced drug resistance of pancreatic cancer is fundamental to a better understanding of gemcitabine-based chemotherapy. Currently available treatment plans involving injectable therapeutics are mainly engineered to improve the performance and broaden their applications in the domain of biomedicine. Fixed-dose-rate infusion of free gemcitabine (Gem) has drawn appropriate attention for its potent anti-tumor efficacy against various solid tumors, whereas it remains a considerable challenge to extend its application and achieve better treatment. Here, we have prepared and demonstrated a long-acting delivery system using gemcitabine and injectable in situ hydrogel for the localized treatment of pancreatic cancer. The hydrogel was prepared using polysaccharide derivatives, oxidized-carboxymethylcellulose (OCMC) and carboxymethylchitosan (CMCS) at optimal ratios by a dopamine-functionalized method for the controlled release of Gem. In vitro drug release behaviors for up to a week indicated sustained drug release of the Gem delivery system. Moreover, desirable apoptosis promotion and apparent cellular proliferation inhibition associated with the drug depot have been found in vitro against BxPC-3 pancreatic cancer cells, bringing minimized side effects to systemic normal tissues. The current findings manifested that the release out of the localized delivery platform in a sustained pattern afforded a durable gemcitabine-based chemotherapy effect and inhibited tumor metastasis more persistently after intratumoral injection of the Gem@Gel system, thereby advancing the development of novel drug-loaded materials with properties not accessed previously.

Gauging surface charge distribution of live cell membrane by ionic current change using scanning ion conductance microscopy.

The distribution of surface charge and potential of cell membrane plays an indispensable role in cellular activities. However, probing surface charge of live cells under physiological conditions, until recently, remains an arduous challenge owing to the lack of effective methods. Scanning ion conductance microscopy (SICM) is an emerging imaging technique for imaging a live cell membrane in its native state. Here, we introduce a simple SICM based imaging technique to effectively map the surface charge contrast distribution of soft substrates including cell membranes by utilizing the higher surface charge sensitivity of the ionic current when the nanopipette tip is close to the substrate with a relatively high current change. This technique was assessed on charged model substrates made of polydimethylsiloxane, and the surface charge sensitivity of ionic current change was supported by finite element method simulations. With this method, we can distinguish the surface charge difference between the cell membrane and the supporting collagen matrix. We also observed the surface charge change induced by the small membrane damage after 1% dimethyl sulfoxide (DMSO) treatment. This new SICM technique provides opportunities to study interfacial and cell membrane processes with high spatial resolution.

AS1411 and EpDT3-conjugated silver nanotriangle-mediated photothermal therapy for breast cancer and cancer stem cells.

Aim: This study aimed to construct AS1411 and EpDT3-conjugated PEGylated silver nanotriangles (AENTs) and assess their ability to target breast cancer and cancer stem cells, as well as the antitumor and antimetastatic effects of AENT-mediated photothermal therapy. Materials & methods: AENTs were constructed and characterized. The targeting properties, as well as antitumor and antimetastatic activities, were evaluated in MDA-MB-231 breast cancer cells, cancer stem cells and breast cancer-bearing mice. Results: AENTs displayed excellent targeting property to breast cancer cells and cancer stem cells. AENT-mediated photothermal therapy greatly inhibited (>45%) the migration and invasion of breast cancer cells, as well as tumor growth and lung metastasis in the mice. Conclusion: AENT-mediated photothermal therapy might be an effective strategy for the treatment of breast cancer.

Immunogenic Cell Death Induced by Chemoradiotherapy of Novel pH-Sensitive Cargo-Loaded Polymersomes in Glioblastoma.

BACKGROUND: Inducing the immunogenic cell death of tumour cells can mediate the occurrence of antitumour immune responses and make the therapeutic effect more significant. Therefore, the development of treatments that can induce ICD to destroy tumour cells most effectively is promising. Previously, a new type of pH-sensitive polymersome was designed for the treatment of glioblastoma which represents a promising nanoplatform for future translational research in glioblastoma therapy. In this study, the aim of this work was to analyse whether chemoradiotherapy of the novel pH-sensitive cargo-loaded polymersomes can induce ICD. METHODS: Cell death in U87-MG and G422 cells was induced by Au-DOX@PO-ANG, and cell death was analysed by CCK-8 and flow cytometry. The release of CRT was determined by using laser scanning confocal microscopy and flow cytometry. ELISA kits were used to detect the release of HMGB1 and ATP. The dying cancer cells treated with different treatments were cocultured with bone-marrow-derived dendritic cells (BMDCs), and then flow cytometry was used to determine the maturation rate of BMDCs (CD11c+CD86+CD80+) to analyse the in vitro immunogenicity. Tumour vaccination experiments were used to evaluate the ability of Au-DOX@PO-ANG to induce ICD in vivo. RESULTS: We determined the optimal treatment strategy to evaluate the ability of chemotherapy combined with radiotherapy to induce ICD and dying cancer cells induced by Au-DOX@PO-ANG+RT could induce calreticulin eversion to the cell membrane, promote the release of HMGB1 and ATP, and induce the maturation of BMDCs. Using dying cancer cells induced by Au-DOX@PO-ANG+RT, we demonstrate the efficient vaccination potential of ICD in vivo. CONCLUSION: These results identify Au-DOX@PO-ANG as a novel immunogenic cell death inducer in vitro and in vivo that could be effectively combined with RT in cancer therapy.

Formation of a combined Ca/Cd toxicity on lifespan of nematode Caenorhabditis elegans.

We investigated the possible formation of combined toxicity from Ca/Cd exposure on nematode lifespan. Ca exposure at concentrations more than 1.56 mM significantly reduced lifespan, accelerated aging-related declines, and induced severe stress response in wild-type nematodes. Combined Ca (25 mM)/Cd (200 microM) exposure decreased the lifespans compared to Cd (200 microM) exposure; whereas no lifespan differences were found between Ca (1.56 mM)/Cd (200 microM) exposure and Cd (200 microM) exposure. Combined Ca (25 mM)/Cd (200 microM) exposure caused a more significant induction of hsp-16.2::gfp expression, and a more severe increase in oxidative damage than Cd (200 microM) exposure. Moreover, mutation of mev-1, encoding a subunit of succinate dehydrogenase cytochrome b, enhanced the combined Ca/Cd toxicity on lifespan. Furthermore, mutation of daf-16, encoding a fork-head-family transcription factor, enhanced the combined Ca/Cd toxicity on lifespan, and mutation of daf-2, encoding an insulin receptor-like protein, alleviated the combined Ca/Cd toxicity on lifespan.

Silver Nanotriangles and Chemotherapeutics Synergistically Induce Apoptosis in Glioma Cells via a ROS-Dependent Mitochondrial Pathway.

BACKGROUND: The synergistic effect of nanomaterials and chemotherapeutics provides a novel strategy for the treatment of tumors. Silver nanotriangles (AgNTs) exhibited some unique properties in nanomedicine. Studies on the synergy of silver-based nanomaterials and anti-tumor drugs against gliomas are rare. MATERIALS AND METHODS: Chitosan-coated AgNTs were prepared, followed by characterization using transmission electron microscopy, ultraviolet-visible spectroscopy and X-ray diffraction. The anti-glioma effect of cyclophosphamide (CTX), 5-fluorouracil (5-FU), oxaliplatin (OXA), doxorubicin (DOX) or gemcitabine (GEM) combined with AgNTs in different glioma cell lines (U87, U251 and C6) was assessed by the MTT assay to screen out a drug with the most broad-spectrum and strongest synergistic anti-glioma activity. The intracellular reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP) and cell apoptosis were detected by flow cytometry. The possible underlying mechanisms of the synergy were further investigated with ROS scavenger and specific inhibitors of C-jun N-terminal kinase (JNK), p38 and extracellular signal-regulated kinase 1/2 pathways. RESULTS: The synthesized AgNTs were mainly triangular and truncated triangular with an average edge length of 125 nm. A synergistic anti-glioma effect of AgNTs combined with CTX was not observed, and the synergism between AgNTs and 5-FU was cell type-specific. AgNTs combined with OXA, DOX or GEM displayed synergistic effects in various glioma cell lines, and the combination of AgNTs and GEM showed the strongest synergistic activity. A decrease in cell viability, loss of the MMP and an increase in apoptosis rate induced by this synergy could be significantly attenuated by the ROS scavenger N-acetylcysteine and JNK inhibitor SP600125. CONCLUSION: Our results suggested that the combination of AgNTs and GEM possessed broad-spectrum and potent synergistic anti-glioma activity, resulting from cell apoptosis mediated by a ROS-dependent mitochondrial pathway in which JNK might be involved.