Smart Human-Serum-Albumin-As2 O3 Nanodrug with Self-Amplified Folate Receptor-Targeting Ability for Chronic Myeloid Leukemia Treatment

Arsenic trioxide (ATO, As2 O3 ) is currently used to treat acute promyelocytic leukemia. However, expanding its use to include high-dose treatment of other cancers is severely hampered by serious side effects on healthy organs. To address these limitations, we loaded ATO onto folate (FA)-labeled human serum albumin (HSA) pretreated with glutathione (GSH) based on the low pH- and GSH-sensitive arsenic-sulfur bond, and we termed the resulting smart nanodrug as FA-HSA-ATO. FA-HSA-ATO could specifically recognize folate receptor-β-positive (FRβ+) chronic myeloid leukemia (CML) cells, resulting in more intracellular accumulation of ATO. Furthermore, the nanodrug could upregulate FRβ expression in CML cancer cells and xenograft tumor model, facilitating even more recruitment and uptake of FRβ-targeting drugs. In vitro and in vivo experiments indicate that the nanodrug significantly alleviates side effects and improves therapeutic efficacy of ATO on CML and xenograft tumor model.

Arsenoplatin-1 Is a Dual Pharmacophore Anticancer Agent

Arsenoplatins are adducts of two chemically important anticancer drugs, cisplatin and arsenic trioxide, that have a Pt(II) bond to an As(III) hydroxide center. Screens of the NCI-60 human tumor cell lines reveal that arsenoplatin-1 (AP-1), [Pt(μ-NHC(CH3)O)2ClAs(OH)2], the first representative of this novel class of anticancer agents, displays a superior activity profile relative to the parent drugs As2O3 or cisplatin in a majority of cancer cell lines tested. These activity profiles are important because the success of arsenic trioxide in blood cancers (such as APL) has not been seen in solid tumors due to the rapid clearance of arsenous acid from the body. To understand the biological chemistry of these compounds, we evaluated interactions of AP-1 with the two important classes of biomolecules-proteins and DNA. The first structural studies of AP-1 bound to model proteins reveal that platinum(II) binds the Nε of His in a manner that preserves the Pt-As bond. We find that AP-1 readily enters cells and binds to DNA with an intact Pt-As bond (Pt:As ratio of 1). At longer incubation times, however, the Pt:As ratio in DNA samples increases, suggesting that the Pt-As bond breaks and releases the As(OH)2 moiety. We conclude that arsenoplatin-1 has the potential to deliver both Pt and As species to a variety of hematological and solid cancers.

Arsenic trioxide and/or copper sulfate induced apoptosis and autophagy associated with oxidative stress and perturbation of mitochondrial dynamics in the thymus of Gallus gallus

Arsenic (As) and copper (Cu) are ubiquitous environmental contaminants that are hazardous to the immune system. Our objective was to investigate the toxicity and potential mechanisms of thymus exposure to As and/or Cu. A chicken model was established by adding arsenic trioxide (As₂O₃; 30 mg/kg), copper sulfate (CuSO₄; 300 mg/kg), and simultaneously both elements in the basal diet. After the chickens were fed for 12 weeks, a significant reduction in antioxidant enzyme levels or production of malondialdehyde (MDA) emphasized the occurrence of oxidative stress. Furthermore, an imbalance in mitochondrial dynamics along with its abnormal structure certified mitochondrial dysfunction. Additionally, elevated levels of pro-apoptotic and autophagy genes and decreased levels of antiapoptotic genes were found in treated groups. Karyopyknosis and chromatin peripheral condensation were accompanied by an increased apoptosis ratio, as well as accumulation of autophagosomes, thus indicating that apoptosis and autophagy are involved in immune cell death. All of the above thymus lesions and index abnormalities occurred in a time-dependent manner, and the Cu and As co-administered groups showed more deteriorating effects than the Cu and As groups alone. Moreover, in the As or Cu group, the thymus tissue suffered different susceptibilities in oxidative toxicity, which needs further study. Collectively, our results manifested that co-exposure to As and Cu increased the oxidative burden and exacerbated mitochondrial dysfunction on the thymus. Additionally, apoptosis and autophagy may act as partners in inducing cell death in a cooperative manner in chicken thymus after As and/or Cu exposure.

Surface-modified PLGA nanoparticles with PEG/LA-chitosan for targeted delivery of arsenic trioxide for liver cancer treatment: Inhibition effects enhanced and side effects reduced

Arsenic trioxide (As₂O₃), an effective drug for leukemia, is limited to be used for solid tumor treatment due to its high side effects. In this study, polyethylene glycol (PEG) and lactobionic acid (LA) modified chitosan (PLC) was synthesized and was used to coat poly(lactide-co-glycolide) (PLGA) nanoparticles for encapsulation and targeted release of As₂O₃ in liver cancer treatment. The As₂O₃-loaded PLGA/PLC nanoparticles (As₂O₃-PLGA/PLC NPs) were fabricated through double emulsion-solvent evaporation method and were optimized by orthogonal tests. As₂O₃-PLGA/PLC NPs presented suitable physical stability, positive charge, high encapsulation efficiency and drug loading, and good biocompatibility. As expected, the NPs can quickly release enough dose of As₂O₃ in a short time and then sustain the drug concentration. The As₂O₃-PLGA/PLC NPs showed effective inhibition of SMMC-7721 cells while having lower cytotoxicity against normal human liver cells (LO2 cells). Furthermore, In vivo study showed that the NPs did not present toxic effects on kidney and liver, but showed relatively high growth inhibition effect on liver tumor. Therefore, this PLGA/PLC NPs could be an effective and safe drug delivery system for liver cancer chemotherapy.

Zeolitic Imidazolate Framework-8 as pH-Sensitive Nanocarrier for "Arsenic Trioxide" Drug Delivery

Previous results revealed that arsenic trioxide might be used as promising therapeutic agent for the treatment of some solid tumours as atypical teratoid rhabdoid tumours (ATRT). However, in order to become an approved drug for solid tumour treatment, the active formulation has to get more efficient and feasible-but at the same time less toxic. One of the possibilities to achieve this dichotomy is to use nanomedicine tools. Herein, we report on the Zn-based metal-organic framework ZIF-8 (Zeolitic Imidazolate Framework-8) which turned out to be a promising candidate for the delivery of AsIII species. It conjointly features a high drug loading capacity and a prominent pH-triggered release behaviour. AsIII -loaded ZIF-8 nanoparticles coated and non-coated with polyethylene glycol were studied by XRPD, IR, Raman, TGA, TEM, EDX, CHN-elemental analysis, sorption analysis and ICP-OES, and their cytotoxicity was evaluated in vitro.

Characterization of arsenic oxidation and uranium bioremediation potential of arsenic resistant bacteria isolated from uranium ore

Arsenic (As) is often found naturally as the co-contaminant in the uranium (U)-contaminated area, obstructing the bioremediation process. Although the U-contaminated environment harbors microorganisms capable of interacting with U which could be exploited in bioremediation. However, they might be unable to perform with their full potential due to As toxicity. Therefore, potential in arsenic resistance and oxidation is greatly desired among the microorganisms for a continued bioremediation process. In this study, arsenic-resistant bacteria were isolated from U ore collected from Bundugurang U mine, characterized and their As oxidation and U removal potentials were determined. 16S rRNA gene sequencing and phylogenetic analysis showed the affiliation of isolated bacteria with Microbacterium, Micrococcus, Shinella, and Bacillus. Except Bacillus sp. EIKU7, Microbacterium sp. EIKU5, Shinella sp. EIKU6, and Micrococcus sp. EIKU8 were found to resist more than 400 mM As(V); however, all the isolates could survive in 8 mM As(III). The isolates were found to readily oxidize As under different culture conditions and are also resistant towards Cd, Cr, Co, Ni, and Zn. All the isolates could remove more than 350 mg U/g dry cells within 48 h which were found to be highly dependent upon the concentration of U, biomass added initially, and on the time of exposure. Ability of the isolates to grow in nitrogen-free medium indicated that they can flourish in the nutrition deprived environment. Therefore, the recovery of isolates with the potent ability to resist and oxidize As from U ore might play an important role in toxic metal bioremediation including U.

Investigation of HSA as a biocompatible coating material for arsenic trioxide nanoparticles

The anticancer properties of arsenic trioxide (As2O3) are accompanied by highly cytotoxic effects on normal cells. This necessitates developing modalities towards the targeted delivery of As2O3. Albumins, on account of their large structure and presence of several interacting groups, are ideal for encapsulating or carrying various drugs. In the present study, human serum albumin (HSA) was chosen as a coating agent to increase the biocompatibility of As2O3. An in situ chemical precipitation method was adopted for the synthesis of HSA-coated As2O3 nanoparticles (HSA-As2O3NPs) that were further characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectroscopy, inductively coupled plasma atomic emission spectrometry (ICP-AES), zeta potential and transmission electron microscopy (TEM). HSA-As2O3NPs were assessed for their biocompatibility using mouse fibroblast cells (NIH-3T3) and human dermal fibroblast (HDF) cells by a time- and dose-dependent cytocompatibility MTT assay. The safety of the HSA-As2O3 nanoparticles was assessed using haemolysis and blood cell aggregation studies. Molecular simulation studies provided evidence of interaction between HSA and As2O3. Herein, we report the development of a protein-based delivery system for As2O3 with improved biocompatibility.

Thiolated chitosan nanoparticles for stable delivery and smart release of As2O3 for liver cancer through dual actions

In this work, multifunctional thiolated chitosan derivatives (DCA-CS-PEG-FA-NAC) were synthesized, and arsenic trioxide (ATO) was loaded onto the derivatives through glutathione (GSH)-sensitive As^III-S bonds, and stable CS-ATO nanodrugs were prepared by simple self-assembly method. By adjusting the thiol substitution degree of CS, the drug loading capacity of the nanodrugs was significantly improved, which could reach 20 ATO per CS molecule (DCA_10.7-CS-PEG_3.1-FA-NAC_20.2-ATO). In vitro release studies obviously showed the low leakage of ATO under physiological conditions while over 95 % ATO was released after 24 h under GSH. In vitro and in vivo investigations demonstrated that the DCA_10.7-CS-PEG_3.1-FA-NAC_20.2-ATO nanodrug could significantly enhance the tumor intracellular accumulation of ATO, reduce the toxic and side effects of ATO on healthy organs, and improve the therapeutic effect of ATO on the HepG2 mice tumor model (tumor inhibition rate was as high as 86.4 %), indicating the potential application of ATO in clinical treatment of liver cancer.

In vitro stability of arsenic trioxide-liposome encapsulates for acute promyelocytic leukemia treatment

In this work, we investigated the stability of arsenic trioxide (ATO) used in leukemia treatment, encapsulated with nanoliposome, with the aid of ultrasound treatment. Stability studies of As species were followed by liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS), allowing for the detection of the conversion of low amounts of As(III) to As(V) or the formation of other As species. The influence of storage temperature and time on ATO was evaluated. Low amounts of As(III) to As(V) conversions were observed when the As encapsulated with nanoliposome was incubated at 25 °C and 40 °C. However, As(III) was stable if the solution was maintained at 5 °C, even after 90 days. No formation of other As species was observed, indicating good stability of the encapsulated ATO. Next step of the work will focus on spray drying of ATO nanoliposomes-encapsuleted with the aim of long term stability of As.

Iodide Analogs of Arsenoplatins-Potential Drug Candidates for Triple Negative Breast Cancers

Patients with triple negative breast cancers (TNBCs)—highly aggressive tumors that do not express estrogen, progesterone, and human epidermal growth factor 2 receptors—have limited treatment options. Fewer than 30% of women with metastatic TNBC survive five years after their diagnosis, with a mortality rate within three months after a recurrence of 75%. Although TNBCs show a higher response to platinum therapy compared to other breast cancers, drug resistance remains a major obstacle; thus, platinum drugs with novel mechanisms are urgently needed. Arsenoplatins (APs) represent a novel class of anticancer agents designed to contain the pharmacophores of the two FDA approved drugs cisplatin and arsenic trioxide (As₂O₃) as one molecular entity. Here, we present the syntheses, crystal structures, DFT calculations, and antiproliferative activity of iodide analogs of AP-1 and AP-2, i.e., AP-5 and AP-4, respectively. Antiproliferative studies in TNBC cell lines reveal that all AP family members are more potent than cisplatin and As₂O₃ alone. DFT calculations demonstrate there is a low energy barrier for hydrolysis of the platinum-halide bonds in arsenoplatins, possibly contributing to their higher cytotoxicities compared to cisplatin.

Arsenic trioxide activates yes-associated protein by lysophosphatidic acid metabolism to selectively induce apoptosis of vascular smooth muscle cells

Inhibition of vascular smooth muscle cells (VSMCs) proliferation without dysregulating endothelial cells (ECs) may provide an ideal therapy for in-stent restenosis. Due to its anti-proliferation effect on VSMCs and pro-endothelium effect, arsenic trioxide (ATO) has been used in a drug-eluting stent in a recent clinical trial. However, the underlying mechanism by which ATO achieves this effect has not been determined. In the present work, we showed that ATO induced apoptosis in VSMCs but not in ECs. Mechanistically, ATO achieved this through modulation of cellular metabolism to increase lysophosphatidic acid (LPA) in VSMCs, while LPA concentration was stable in ECs. The elevated LPA facilitated the nuclear accumulation and initiated the transcriptional function of Yes-associated protein (YAP) in VSMCs. YAP regulated the transcription of N6-Methyladenosine (m⁶A) modulators (Mettl14 and Wtap) to increase the m⁶A methylation levels of apoptosis-related genes to induce their high expression and exacerbate VSMCs apoptosis. On the other hand, YAP nuclear accumulation in ECs was not observed. Collectively, our data exhibited the molecular process involved in selective apoptosis of VSMCs induced by ATO.

Metal-organic chelator frameworks for arsenic-based cancer treatment

The off-target toxicity of arsenic trioxide chemotherapy is a common Achilleś heel of metallodrugs. This limitation is usually mitigated by employing various cargo agents capable of transporting arsenic species to specific sites. More specifically, two of the most explored strategies to address arsenic trioxide's off-target toxicity include: (i) the complexation of As(III) species with chelating agents and (ii) their immobilization, either on the surface or, within non-porous and porous nanomaterials. In this work, we have explored the combination of mercaptosuccinic acid, an arsenic chelator, with zirconium oxo-clusters to assemble two new microporous Metal-Organic Frameworks (MOFs), denoted as BCM-1 and BCM-2 (BCM referring to Basque Center for Materials, Applications & Nanostructures). The specific chemical and structural features of these news frameworks have enabled controlling the arsenic loading and release in different scenarios. Specifically, arsenic release accelerates under oxidative conditions due to the rupture of thiol-arsenic bonds, caused by the oxidation of -SH groups to -SO3 within the MOF. Additionally, in acidic conditions typical of cancer microenvironments, the framework itself disassembles, further facilitating arsenic release. The particle size and arsenic loading capacity of BCM-1 can be easily modulated by controlling the synthesis conditions. This strategy has led to the development of micrometric, nanometric and gel-like materials, whose chemical stability in acidic and biological relevant media has been duly assessed. Notably, arsenic release from nano-BCM-1 is able to reverse the growth curve of HeLa cancer cells in approximately 50 h. This discovery paves the way towards the use of metal-chelator organic molecules in assembling new MOF materials capable of controlling the cargo and release of metallodrugs under in-vivo conditions.

Targeted pH-responsive biomimetic nanoparticle-mediated starvation-enhanced chemodynamic therapy combined with chemotherapy for ovarian cancer treatment

In recent years, the use of arsenic trioxide (ATO) in the context of ovarian cancer chemotherapy has attracted significant attention. However, ATO's limited biocompatibility and the occurrence of severe toxic side effects hinder its clinical application. A nanoparticle (NP) drug delivery system using ATO as a therapeutic agent is reported in this study. Achieving a synergistic effect by combining starvation therapy, chemodynamic therapy, and chemotherapy for the treatment of ovarian cancer was the ultimate goal of this system. This nanotechnology-based drug delivery system (NDDS) introduced arsenic-manganese complexes into cancer cells, leading to the subsequent release of lethal arsenic ions (As3+) and manganese ions (Mn2+). The acidic microenvironment of the tumor facilitated this process, and MR imaging offered real-time monitoring of the ATO dose distribution. Simultaneously, to produce reactive oxygen species that induced cell death through a Fenton-like reaction, Mn2+ exploited the surplus of hydrogen peroxide (H2O2) within tumor cells. Glucose oxidase-based starvation therapy further supported this mechanism, which restored H2O2 and lowered the cellular acidity. Consequently, this approach achieved self-enhanced chemodynamic therapy. Homologous targeting of the NPs was facilitated through the use of SKOV3 cell membranes that encapsulated the NPs. Hence, the use of a multimodal NDDS that integrated ATO delivery, therapy, and monitoring exhibited superior efficacy and biocompatibility compared with the nonspecific administration of ATO. This approach presents a novel concept for the diagnosis and treatment of ovarian cancer.

Maximizing arsenic trioxide's anticancer potential: Targeted nanocarriers for solid tumor therapy

Arsenic trioxide (ATO) has gained significant attention due to its promising therapeutic effects in treating different diseases, particularly acute promyelocytic leukemia (APL). Its potent anticancer mechanisms have been extensively studied. Despite the great efficacy ATO shows in fighting cancers, drawbacks in the clinical use are obvious, especially for solid tumors, which include rapid renal clearance and short half-life, severe adverse effects, and high toxicity to normal cells. Recently, the emergence of nanomedicine offers a potential solution to these limitations. The enhanced biocompatibility, excellent targeting capability, and desirable effectiveness have attracted much interest. Therefore, we summarized various nanocarriers for targeted delivery of ATO to solid tumors. We also provided detailed anticancer mechanisms of ATO in treating cancers, its clinical trials and shortcomings as well as the combination therapy of ATO and other chemotherapeutic agents for reduced drug resistance and synergistic effects. Finally, the future study direction and prospects were also presented.

A therapeutic strategy integrating ultrasound-guided microwave ablation with nanocomposite hydrogels to enhance autophagy and suppress tumor growth in hepatocellular carcinoma

Microwave ablation (MWA) is widely recognized as an effective radical therapy for hepatocellular carcinoma (HCC). However, local ablation often results in a high risk of tumor recurrence. To address this challenge, we developed an effective anticancer drug delivery system comprising arsenic trioxide (As2O3)-loaded polyethylene glycol-dipalmitoylphosphatidylethanolamine (mPEG-DPPE) calcium phosphate nanoparticles (As2O3NPs) encapsulated within an injectable thermoresponsive hydrogel (ANPs-Gel). This study evaluated the therapeutic efficacy of MWA combined with ANPs-Gel in a rabbit hepatic VX2 tumor model. Ultrasound (US) and contrast-enhanced ultrasound (CEUS) were employed to assess tumor response and angiogenesis following treatment. The results demonstrated that MWA combined with ANPs-Gel significantly enhanced antitumor efficacy compared to other treatments, effectively inhibiting tumor growth and angiogenesis. Mechanistically, the therapeutic effects were associated with autophagy induced by MWA+ANPs-Gel, which played a critical role in promoting tumor cell death and suppressing epithelial-mesenchymal transition (EMT) both in vitro and in vivo. In vivo experiments further highlighted that the injectable thermoresponsive hydrogel system not only prolonged drug retention at the tumor site but also enhanced therapeutic efficacy by reducing EMT and preventing tumor recurrence. These findings suggest that MWA combined with ANPs-Gel provides a promising strategy for improving treatment outcomes in HCC through ultrasound-guided chemotherapy and targeted autophagy modulation. STATEMENT OF SIGNIFICANCE: This study introduces a potent therapeutic strategy that integrates ultrasound-guided microwave ablation (MWA) with a nanocomposite hydrogel to enhance autophagy and suppress tumor growth in hepatocellular carcinoma, as demonstrated in the rabbit VX2 hepatic tumor model. By combining advanced ultrasound guidance with a sophisticated nanomaterial platform, this approach significantly improves the efficacy of localized cancer therapy. Unlike conventional treatments, it not only ablates tumor cells but also regulates key cellular processes, such as autophagy, to amplify therapeutic outcomes. This work repurposes arsenic trioxide (Arsenic Trioxide) within a nanocomposite hydrogel delivery system and provides a detailed exploration of its therapeutic mechanisms when combined with MWA therapy. These findings pave the way for advanced clinical strategies in liver cancer management.

Antibacterial, antifungal and enzymatic activities of azithromycin-heavy metal complexes: Newly synthesized and characterized

As part of our continuous research to understand the interaction mechanism of drug and metallo-elements, heavy metal complexes of azithromycin (AZI) were synthesized with arsenic oxide, lead carbonate and silver chloride salts in molar ratio of 2: 1 (L: M). Synthesized heavy metal complexes have shown good percent yield and characterized through spectroscopic parameters including UV-Visible, TLC, FT-IR, NMR and elemental analysis (CHN). Spectroscopic characterization reveals the binding of ligand AZI with heavy metals in bi-dentate manner involving the hydroxide and 9a-NCH3 group of the aglycone ring of AZI. These newly synthesized heavy metal complexes were evaluated for their antimicrobial response against selected gram positive and gram negative organisms and antifungal species. It was noted that all newly synthesized complexes exhibits increased activity against B.subtilus whereas, AZI itself didn't show any activity, while synthesized complexes have low to moderate response against all the studied organisms. Complex A-M12 possess greater enzymatic response against both urease and alpha chymotrypsin among all the studied complexes. Results obtained were then statistically analyzed through one way ANOVA and Dunnett's test by using SPSS version 20.0 suggesting the significant response of complexes against selected organisms.

Geomechanical aspects of stabilizing arsenic trioxide roaster waste in cemented paste backfill at the Giant Mine, Canada

Giant Mine, an abandoned gold mine near Yellowknife in the Northwest Territories of Canada, generated significant arsenic trioxide roaster waste (ATRW) during its operations, posing a substantial environmental hazard. This study explored the feasibility of stabilizing ATRW by incorporating it into cemented paste backfill (CPB). Using response surface methodology (RSM), CPB samples with varying mixing ratios were analyzed to identify key parameters influencing strength. Unconfined compressive strength (UCS) tests assessed physical stability, while saturated hydraulic conductivity and computed tomography (CT) analyses examined the microstructure of the CPB. The results revealed that CPB samples prepared with general use (GU) cement exhibited significantly higher strength than those with a GU and lime kiln dust (LKD) mixture. Binder and solid contents were identified as the most critical factors influencing UCS, with binder content having a more pronounced influence. Curing time was found to be non-significant. Higher binder and solid contents correlated with higher UCS values in the CPB samples. The addition of 10% wt. ATRW reduced the UCS by over 30%, particularly in samples with lower binder and solid contents. Although microstructure differences were not evident in saturated hydraulic conductivity tests, CT scans showed increased formation of high-density arsenic-containing materials in samples with the highest UCS, especially those using GU binder. These findings suggest that optimizing binder and solid contents is crucial for enhancing CPB strength and effectively stabilizing ATRW.

AS1411aptamer conjugated liposomes for targeted delivery of arsenic trioxide in mouse xenograft model of melanoma cancer

Development of AS1411aptamer-conjugated liposomes for targeted delivery of arsenic trioxide is the primary goal of this study. AS1411aptamer was used as ligand to target nucleolin, which is highly expressed on the surface of melanoma cancer cells. The targeted liposomes were constructed by the thin film method, and arsenic trioxide was loaded as cobalt (II) hydrogen arsenite (CHA) to increase the loading efficiency and stability of the liposomes. The liposomal structure was characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and field emission scanning electron microscopy (FESEM). In addition, particle sizes and zeta potential of the CHA-loaded liposomes (CHAL) and aptamer-functionalized CHA-loaded liposomes (AP-CHAL) were determined. In vitro cytotoxicity of CHAL and AP-CHAL were evaluated using MTT assay in murine melanoma (B16) and mouse embryonic fibroblast (MEF) cell lines. The encapsulation efficiency of CHAL and AP-CHAL was reported as 60.2 ± 6.5% and 58.7 ± 4.2%, respectively. In vivo antitumor activity of CHAL and AP-CHAL in the B16 tumor-xenograft mouse model was dramatically observed. All mice of both groups survived until the end of treatment and showed body weight gain. The tumor protrusion completely disappeared in 50% of the mice in these groups. Furthermore, histopathology studies demonstrated that CHAL and AP-CHAL did not induce significant toxicity in healthy mice tissues. However, unlike the CHAL group, which showed an initial increase in tumor volume, a specific antitumor effect was observed in the AP-CHAL group from the beginning of treatment. The results showed that AP-CHAL can be used as an effective drug delivery system with high potential in the treatment of solid tumors.

Efficient capture and detoxification of gaseous arsenic trioxide from flue gas using silicomanganese alloy dust

This study aims to develop efficient capture materials for gaseous arsenic trioxide (As2O3(g)) that can prevent arsenic poisoning in selective catalytic reduction (SCR) systems and reduce atmospheric arsenic emissions from coal-fired power plants. One kind of metallurgical dust from a silicomanganese alloy plant (named as SiMnD) was found to be cost-effective and environmentally friendly for As2O3(g) removal from flue gas for the first time. The sorbent showed excellent performance for gaseous arsenic trioxides capture with a good capacity of 13.82 mg/g at 450 °C in 60 min, which was better than the other reported metal oxides at high temperature. The As2O3(g) capture capacity in 12-h continuous test reached as high as 118.16 mg/g without penetration, and the sorbent showed good long-term durability and pretty good resistance to high concentrations of nitric oxide (NO), sulfur dioxide (SO2) and carbon dioxide (CO2). The sorbent also exhibited good recyclability even after five regeneration cycles. Nearly 92% of As2O3(g) was transformed into manganese (II) pyroarsenate (Mn2As2O7), manganese arsenate (MnAsO4) and diarsenic pentoxide (As2O5) after capture with lower toxicity. The results of Toxicity Characteristic Leaching Procedure (TCLP) and five-step sequential extraction demonstrated that spent SiMnD exhibited low arsenic bioavailability, indicating reduced environmental mobility of arsenic species. Trimanganese tetroxide (Mn3O4) and blythite (Mn3Mn2(SiO4)3) were the most essential active component for As2O3(g) removal and detoxification. The optimal As2O3(g) capture temperature of SiMnD was 450 °C which was suitable to be applied before SCR with little operating cost. SiMnD was proved to be one excellent capture and detoxification agent for As2O3(g) in flue gas at a lower temperature with promising application prospects.

Green-synthesized copper oxide nanoparticles induce apoptosis and up-regulate HOTAIR and HOTTIP in pancreatic cancer cells

Aim: Cu2O nanoparticles were synthesized using an extract from S. latifolium algae (SLCu2O NPs). Their effect on PANC-1 cells and the expression of two drug resistance-related lncRNAs were evaluated in comparison with Arsenic trioxide.Materials & methods: SLCu2O NPs were characterized using XRD, SEM, and TEM microscopies. The effects of SLCu2O NPs on cell cytotoxicity, cell cycle, and apoptosis, and expression of two drug resistance-related lncRNAs were examined using MTT assay, flow cytometry, and real-time PCR, respectively.Results: SLCu2O NPs demonstrated anti-cancer properties against PANC-1 cells comparable to Arsenic trioxide, and the expression of lncRNAs increased upon treatment with them.Conclusion: SLCu2O NPs demonstrate anti-cancer properties against PANC-1 cells; however, using gene silencing strategies along with SLCu2O NPs is suggested.

Conditional Binding of Arsenic Trioxide (ATO) to Cysteine-Rich Zinc Finger Motifs within RBCC Domain of PML Protein

The arsenic trioxide (ATO)-based cure of acute promyelocytic leukemia is attributed to PML/RARα oncoprotein degradation through binding of its RBCC domain (i.e., consist of RING, B-box1, B-box2, and Coiled-coil) with arsenic. Despite ATO being proven to interact with the Cysteine213 triad in the B-box2 trimer of PML-Nuclear Bodies, whether its direct binding to cysteine-rich zinc finger motifs in PML protein, remains unclear. Consequently, we purified the RING, B-box1, and B-box2 domains to assess their potential for arsenic-binding. The results showed that ATO cannot displace zinc ions under physiological conditions but binds with zinc finger domains under zinc-depletion in low-pH conditions, revealing a conditional binding mechanism.

Arsenic sequestration by granular coal gangue functionalized with magnesium: Effects of magnesium and insight of arsenic sorption mechanisms

Leveraging natural waste materials for inorganic contaminant removal in solution offers a novel approach to boost resource recycling and foster sustainable development by enhancing waste use. This research advanced the modest arsenite (As[III]) removal capacity of raw coal gangue through a magnesium-soaking and calcination-based surface modification. Batch experiments showed As(III) removal efficiency was improved from 39.8% to 89.9% after modification, independent of initial pH levels. The Langmuir model estimated the maximum sorption capacity of 0.979 mg/g for the modified coal gangue. Physicochemical analyses confirmed that the modification increased the surface area, pore volume and size of the coal gangue. Furthermore, SEM, and subsequent TEM and SAED analyses identified acicular arsenic trioxide (As2O3) on the modified gangue, enhancing As(III) removal. Variations in sorption kinetics hinted at precipitation, likely due to AsO3 polymer chains formed by As(III)'s sorption onto Mg(OH)2, created from MgO hydration in aqueous conditions. Our findings show that coal gangue has potential applications in the development of sustainable methods for waste recycling.