Effect of size and processing method on the cytotoxicity of realgar nanoparticles in cancer cell lines

Harness arsenic in medicine: current status of arsenicals and recent advances in drug delivery

INTRODUCTION

Arsenicals have a special place in the history of human health, acting both as poison and medicine. Having been used to treat a variety of diseases in the past, the success of arsenic trioxide (ATO) in treating acute promyelocytic leukemia (APL) in the last century marked its use as a drug in modern medicine. To expand their role against cancer, there have been clinical uses of arsenicals worldwide and progress in the development of drug delivery for various malignancies, especially solid tumors.

AREAS COVERED

In this review, conducted on Google Scholar [1977-2024], we start with various forms of arsenicals, highlighting the well-known ATO. The mechanism of action of arsenicals in cancer therapy is then overviewed. A summary of the research progress in developing new delivery approaches (e.g. polymers, inorganic frameworks, and biomacromolecules) in recent years is provided, addressing the challenges and opportunities in treating various malignant tumors.

EXPERT OPINION

Reducing toxicity and enhancing therapeutic efficacy are guidelines for designing and developing new arsenicals and drug delivery systems. They have shown potential in the fight against cancer and emerging pathogens. New technologies and strategies can help us harness the potency of arsenicals and make better products.

Nano-Traditional Chinese Medicine: a promising strategy and its recent advances

Traditional Chinese medicine(TCM) has been applied to the prevention and treatment of numerous diseases and has an irreplaceable role of rehabilitation and health care. However, the application of TCM is...

Investigation on Green Synthesis, Biocompatibility, and Antibacterial Activity of Silver Nanoparticles Prepared Using Cistus incanus

This paper describes the plant-mediated preparation of silver nanoparticles with aqueous extract and infusion of Cistus incanus leaves. To evaluate aqueous extract and infusion antioxidant capacity and total phenolic content the DPPH and Folin-Ciocalteau methods were utilized. The antioxidant capacity and total phenolic content of extract and infusion were equal to 85.97 ± 6.54 mg gallic acid equivalents per gram of dry weight.; 10.76 ± 0.59 mg/mL and 12.65 ± 1.04 mg gallic acid equivalents per gram of dry weight.; 3.10 ± 0.14 mg/mL, respectively. The formed nanoparticles displayed the characteristic absorption band in the 380-450 nm wavelength range. The average size of particles was in the 68.8-71.2 nm range. Morphology and phase composition analysis revealed the formation of spherical nanoparticles with a face-centred cubic structure. Immune compatibility tests of nanoparticles and plant extracts showed no activation of the THP1-XBlue™ monocyte. Cytotoxicity tests performed with L929 mice fibroblasts showed that nanoparticles should be utilized at a concentration of 16 ppm. The minimum inhibitory concentrations determined with the microdilution method for nanoparticles prepared with plant infusion for S. aureus and S. epidermidis were 2 ppm and 16 ppm, respectively.

Arsenic compounds: The wide application and mechanisms applied in acute promyelocytic leukemia and carcinogenic toxicology

Arsenic (As), as well as its various compounds have been widely used for nearly 4000 years either as drugs or poisons. These compounds are valuable in the treatment of various diseases ranging from dermatosis to cancer, thereby emphasizing their important roles as therapeutic agents. The ability of As compounds, especially arsenic trioxide (ATO) in the treatment of acute promyelocytic leukemia (APL), has fundamentally altered people's understanding of the poison, and has become a major factor in the re-emergence of Western medicine candidates to treat leukemia and other solid tumors. However, long-term exposure to As has been correlated with numerous disadvantageous influences on health, particularly carcinogenesis. Importantly, accumulating evidence suggests that biotransformation of As, as a step to eliminate As from the human body, can induce alterations at the genetic and epigenetic levels, resulting in therapeutic effects or carcinogenesis. In this article, we aimed to provide a systematic overview of the primary contributions associated with As and its compounds, as well as the detailed mechanisms applied in APL cells and carcinogenic toxicology. This review may help to understand the underlying mechanisms and safe wide clinical applications of medicinal As along with its compounds.

Influence of the capping of biogenic silver nanoparticles on their toxicity and mechanism of action towards Sclerotinia sclerotiorum

BACKGROUND

Biogenic nanoparticles possess a capping of biomolecules derived from the organism employed in the synthesis, which contributes to their stability and biological activity. These nanoparticles have been highlighted for the control of phytopathogens, so there is a need to understand their composition, mechanisms of action, and toxicity. This study aimed to investigate the importance of the capping and compare the effects of capped and uncapped biogenic silver nanoparticles synthesized using the filtrate of Trichoderma harzianum against the phytopathogenic fungus Sclerotinia sclerotiorum. Capping removal, investigation of the composition of the capping and physico-chemical characterization of the capped and uncapped nanoparticles were performed. The effects of the nanoparticles on S. sclerotiorum were evaluated in vitro. Cytotoxicity and genotoxicity of the nanoparticles on different cell lines and its effects on nontarget microorganisms were also investigated.

RESULTS

The capped and uncapped nanoparticles showed spherical morphology, with greater diameter of the uncapped ones. Functional groups of biomolecules, protein bands and the hydrolytic enzymes NAGase, β-1,3-glucanase, chitinase and acid protease from T. harzianum were detected in the capping. The capped nanoparticles showed great inhibitory potential against S. sclerotiorum, while the uncapped nanoparticles were ineffective. There was no difference in cytotoxicity comparing capped and uncapped nanoparticles, however higher genotoxicity of the uncapped nanoparticles was observed towards the cell lines. Regarding the effects on nontarget microorganisms, in the minimal inhibitory concentration assay only the capped nanoparticles inhibited microorganisms of agricultural importance, while in the molecular analysis of the soil microbiota there were major changes in the soils exposed to the uncapped nanoparticles.

CONCLUSIONS

The results suggest that the capping played an important role in controlling nanoparticle size and contributed to the biological activity of the nanoparticles against S. sclerotiorum. This study opens perspectives for investigations concerning the application of these nanoparticles for the control of phytopathogens.

Arsenic sulfide nanoformulation induces erythroid differentiation in chronic myeloid leukemia cells through degradation of BCR-ABL

Background

Chronic myeloid leukemia (CML) is a myeloproliferative disorder due to the existence of BCR-ABL fusion protein that allows the cells to keep proliferating uncontrollably. Although tyrosine kinase inhibitors can inhibit the activity of BCR-ABL fusion protein to trigger the cells apoptosis, drug resistance or intolerance exists in part of CML patients. Arsenic sulfide in its raw form (r-As₄S₄) can be orally administrated and certain therapeutic effects have been found out in the treatment of hematologic malignancies through inducing cell apoptosis.

Methods

In this work, a water-dissolvable arsenic sulfide nanoformualtion (ee-As₄S₄) composed of As₄S₄ particulates with 470 nm in diameter and encapsulated by a kind of hydrophilic polymer was fabricated and applied to the CML cell line K562, K562/AO2 and primary cells from the bone marrow of CML patients.

Results

Results showed that instead of inhibiting the activity of BCR-ABL, ee-As₄S₄ induced direct degradation of BCR-ABL in K562 cells within 6 hr incubation, followed by the occurrence of erythroid differentiation in K562 after 72 hr incubation, evidenced by the significantly upregulated CD235a and benzidine staining, which was not detectable with r-As₄S₄. The ee-As₄S₄-induced erythroid differentiation was also observed in K562/AO2 cells and bone marrow mononuclear cells of CML patients. Mechanistic studies indicated that ee-As₄S₄ induced autophagy by downregulating the level of intracellular ROS and hypoxia-inducible factor-1α significantly, which led to the subsequent degradation of BCR-ABL. When the concentration was increased, ee-As₄S₄ induced much more significant apoptosis and cell cycle arrest than r-As₄S₄, and the cytotoxicity of the former was about 178 times of the latter.

Conclusion

ee-As₄S₄ was capable of inducing significant erythroid differentiation of CML cells by inducing the direct degradation of BCR-ABL; the new effect could improve hematopoietic function of CML patients as well as inhibit the leukemic cell proliferation.

Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use:

https://youtu.be/7J3UZ1zUFrw

Induction by arsenate of cell-type-specific cytotoxic effects in nerve and hepatoma cells

The aim of the study was to compare the effect of sodium arsenate (AsV) on two different cell types: 158N murine oligodendrocytes and HepG2 human hepatoma cells. Exposure of 158N cells to AsV (0.1-400 µM; 48 h) induced a biphasic cytoxic effect defined as hormesis. Thus, low concentrations of AsV stimulate cell proliferation, as shown by phase-contrast microscopy, cell counting with trypan blue, and crystal violet assay, whereas high concentrations induce cell death associated with a loss of cell adhesion. These side effects were confirmed by staining with propidium iodide and cell cycle analysis, characterized by the presence of a subG1 peak, a criterion of apoptosis. The effects of AsV on mitochondrial function, as determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay, the measurement of mitochondrial transmembrane potential with 3,3'-dihexyloxacarbocyanine iodide, and the rate of mitochondrial adenosine triphosphate confirm the impact of AsV on the mitochondria. In contrast to 158N cells, HepG2 cells were susceptible to all AsV concentrations as shown by microscopic observations, by counting with trypan blue. However, no alteration is noted in the cell membrane integrity, which indicated an apoptotic mode of cell death, and this side effect is confirmed by the cycle analysis, which revealed a subG1 peak. Of note, there was a loss of MTT, suggesting that AsV induces mitochondrial complex II dysfunction. Altogether, our data show that the cytotoxic characteristics of AsV depend on the cell type considered.

Evaluation of cytotoxicity, immune compatibility and antibacterial activity of biogenic silver nanoparticles

The study was focused on assessment of antibacterial activity, cytotoxicity and immune compatibility of biogenic silver nanoparticles (AgNPs) synthesized from Streptomyces sp. NH28 strain. Nanoparticles were biosynthesized and characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, nanoparticle tracking analysis system and zeta potential. Antibacterial activity was tested against Gram-positive and Gram-negative bacteria; minimal inhibitory concentration was recorded. Cytotoxicity was estimated using L929 mouse fibroblasts via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Biocompatibility of AgNPs was performed using THP1-XBlue™ cells. Biogenic AgNPs presented high antibacterial activity against all tested bacteria. Minimum inhibitory concentration of AgNPs against bacterial cells was found to be in range of 1.25-10 μg/mL. Silver nanoparticles did not show any harmful interaction to mouse fibroblast cell line, and no activation of nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) cells was observed at concentration below 10 µg/mL. The half-maximal inhibitory concentration (IC₅₀) value was established at 64.5 μg/mL. Biological synthesis of silver can be used as an effective system for formation of metal nanoparticles. Biosynthesized AgNPs can be used as an antibacterial agent, which can be safe for eukaryotic cells.

Fabrication of water-soluble polymer-encapsulated As4S4 to increase oral bioavailability and chemotherapeutic efficacy in AML mice

Realgar (As4S4) has been demonstrated to be effective for the treatment of acute myeloid leukemia (AML); it has the advantages of no drug resistance and oral administration. Nevertheless, its poor solubility has been an obstacle to its bioavailability, requiring high-dose administration over a long period. We investigated whether crushing realgar crystals to the nanoscale and encapsulating the particles in a water-soluble polymer in one step using hot-melt extrusion would increase the bioavailability of As4S4. Raw As4S4 (r-As4S4) and water-soluble polymer were processed via co-rotating twin screw extrusion. The resulting product (e-As4S4) was characterized by SEM, XRD, and DLS. The cytotoxicity and therapeutic effects of e-As4S4 were evaluated in vivo and in vitro. The results show that e-As4S4 dissolved rapidly in water, forming a stable colloid solution. The average size of e-As4S4 particles was 680 nm, which was reduced by more than 40-fold compared with that of r-As4S4. The bioavailability of e-As4S4 was up to 12.6-fold higher than that of r-As4S4, and it inhibited the proliferation of HL-60 cells much more effectively than did r-As4S4, inducing apoptosis and significantly reducing the infiltration of HL-60 cells into the bone marrow, spleen, and liver. This in turn prolonged the survival of AML mice.

Melatonin releasing PLGA micro/nanoparticles and their effect on osteosarcoma cells

Melatonin loaded poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles and microparticles in the diameter of ∼200 nm and 3.5 μm, respectively, were prepared by emulsion-diffusion-evaporation method. Melatonin entrapment into the particles was significantly improved with the addition of 0.2% (w/v) melatonin into the aqueous phase and encapsulation efficiencies were found as 14 and 27% for nanoparticles and microparticles, respectively. At the end of 40 days, ∼70% of melatonin was released from both of particles, with high burst release. Both blank and melatonin loaded PLGA nanoparticles caused toxic effect on the MG-63 cells due to their uptake by the cells. However, when 0.05 mg microparticle that is carrying ∼1.7 μg melatonin was added to the cm(2) of culture, inhibitory effect of melatonin on the cells were obviously observed. The results would provide an expectation about the usage of melatonin as an adjunct to the routine chemotherapy of osteosarcoma by encapsulating it into a polymeric carrier system.

Apoptosis and necrosis induced by novel realgar quantum dots in human endometrial cancer cells via endoplasmic reticulum stress signaling pathway

Realgar (AS4S4) has been used in traditional medicines for malignancy, but the poor water solubility is still a major hindrance to its clinical use. Realgar quantum dots (RQDs) were therefore synthesized with improved water solubility and bioavailability. Human endometrial cancer JEC cells were exposed to various concentrations of RQDs to evaluate their anticancer effects and to explore mechanisms by the MTT assay, transmission electron microscopy (TEM), flow cytometry, real-time reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. Results revealed that the highest photoluminescence quantum yield of the prepared RQDs was up to approximately 70%, with the average size of 5.48 nm. RQDs induced antipro-liferative activity against JEC cells in a concentration-dependent manner. In light microscopy and TEM examinations, RQDs induced vacuolization and endoplasmic reticulum (ER) dilation in JEC cells in a concentration-dependent manner. ER stress by RQDs were further confirmed by increased expression of GADD153 and GRP78 at both mRNA and protein levels. ER stress further led to JEC cell apoptosis and necrosis, as evidenced by flow cytometry and mitochondrial membrane potential detection. Our findings demonstrated that the newly synthesized RQDs were effective against human endometrial cancer cells. The underlying mechanism appears to be, at least partly, due to ER stress leading to apoptotic cell death and necrosis.

Therapeutic and analytical applications of arsenic binding to proteins

Knowledge of arsenic binding to proteins advances the development of bioanalytical techniques and therapeutic drugs.

Realgar nanoparticle-based microcapsules: preparation and in-vitro/in-vivo characterizations

Objectives

The aim of this study was to prepare microcapsules for the oral delivery of realgar nanoparticles (RN) that are also capable of improving its stability.

Methods

RN and RN-based microcapsules (RNM) were prepared using ball milling and solvent evaporation techniques, respectively. Properties such as particle size, ζ-potential (ZP), morphology and X-ray diffractometer (XRD) were investigated. In addition, drug release, bioavailability and antitumour studies were also performed.

Key findings

The nanoparticles appeared round or elliptical in shape with a mean size of 85.4 ± 3.5 nm and a ZP of −34.3 ± 1.7 mV. The obtained RNM appeared spherical and not aggregated with a relatively narrow size distribution. XRD analysis revealed that ball milling technique did not change the crystallinity of the realgar powder. RN and RNM exhibited considerable higher release of As2S2, bioavailability and antitumour efficacies compared with crude realgar. Furthermore, RNM could protect RN directly exposed to the air and light, and therefore increased the stability of the RN.

Conclusions

The developed RNM demonstrated a greater potential as a delivery system for realgar.

Differential cytotoxicity and particle action of hydroxyapatite nanoparticles in human cancer cells

Aim: While hydroxyapatite nanoparticles (HAPNs) have been reported to exhibit anticancer effects on several types of human cancer cells, no investigation has been performed to compare their cytotoxicity with different types of cancer cells. The objective of the present study is to investigate the cytotoxic action of HAPNs in different types of human cancer cell and to explore the possible mechanisms involved. Materials & methods: Rod-shaped HAPNs were prepared by the aqueous precipitation method and then labeled with ?uorescein isothiocyanate to visualize the cellular uptake and distribution. Their cytotoxicity to three human carcinoma cell lines (gastric cancer cells [MGC80-3], cervical adenocarcinoma epithelial cells [HeLa] and hepatoma cells [HepG2], as well as to normal human hepatocyte cells [L-02]) was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was characterized by the changes in nuclear morphology with 4’,6-diamidino-2-phenylindole staining and by ?ow cytometric analysis with Annexin V-?uorescein isothiocyanate/propidium iodide double staining. Furthermore, the activity of apoptotic proteins (caspase-3, -8 and -9), intracellular reactive oxygen species and glutathione levels were analyzed in HAPN-treated cells. The cellular uptake of HAPNs was studied using flow cytometry analysis, and changes in intracellular calcium levels were investigated using the Ca2+-sensitive fluorescent dye, fluo-3 AM. Results: HAPNs significantly inhibited cell proliferation and induced apoptosis of cancer cells with an order of MGC80-3 > HepG2 > HeLa, but had no impact on normal hepatic cells (L-02). The increase in apoptosis was accompanied by the activation of caspase-3 and -9, but not activation of caspase-8. Moreover, HAPN treatment led to reactive oxygen species generation and decreased intracellular glutathione in cancer cells, with the most remarkable reactive oxygen species burst in HeLa cells. The degree of cytotoxicity did not correlate with the cellular uptake efficiency of HAPNs. However, more HAPNs were found inside the nucleus of MGC80-3 cells, and an increase in the intracellular calcium level was observed in all cancer cells, with the highest level also detected in MGC80-3. Conclusion: Varying cytotoxicity of HAPNs was observed in different cancer cell types. Our results suggest that possible mechanisms of cytotoxicity in various types of cancer cells could be different. The elevated calcium concentration and nuclear localization of the particles might be the main mechanism of growth inhibition by HAPNs in cancer cells.

Original submitted 18 April 2012; Revised submitted 14 September 2012; Published online 24 April 2013

Silencing of the human SET gene in vitro with lentivirus-mediated RNA interference

In our previous study, SET was identified as one of the differentially expressed proteins that was associated with tetra-arsenic tetra-sulfide (As4S4)-induced NB4-R1 [retinoic acid-resistant acute promyelocytic leukemia (APL) cell line] apoptosis. However, the mechanism through which SET regulates pathways during this process remains unclear. The aim of this study was to construct lentivirus-mediated short hairpin RNA (shRNA) against SET and investigate the effect of SET on As4S4-induced retinoic acid-resistant APL cell apoptosis. In the present study, 4 different oligonucleotides targeting the human SET gene were synthesized and cloned into the eukaryotic expression plasmid pGCSIL-GFP. The recombinant vectors were introduced into NB4-R1 cells. The silencing efficiency was measured by real-time quantitative PCR (RT-qPCR) and western blotting. Our results showed that the 4 recombinant RNA interference (RNAi) vectors were constructed successfully. Fluorescence microscopy demonstrated that infection efficiency ranged from 70 to 90%. Infection with the 4 different RNAi vectors significantly knocked down the expression of SET by 52.8, 69.1, 48.9 and 90.3% at the mRNA level, and 92.5, 96.3, 91.7 and 98.4% at the protein level, respectively. We attempt to clarify the mechanism of As4S4 treatment on retinoic acid-resistant APL.

Anticancer drugs from traditional toxic Chinese medicines

Many anticancer drugs are obtained from natural sources. Nature produces a variety of toxic compounds, which are often used as anticancer drugs. Up to now, there are at least 120 species of poisonous botanicals, animals and minerals, of which more than half have been found to possess significant anticancer properties. In spite of their clinical toxicity, they exhibit pharmacological effects and have been used as important traditional Chinese medicines for the different stages of cancer. The article reviews many structures such as alkaloids of Camptotheca acuminata, Catharanthus roseus and Cephalotaxus fortunei, lignans of Dysosma versipellis and Podophyllum emodi, ketones of Garcinia hanburyi, terpenoids of Mylabris and Ginkgo biloba, diterpenoids of Tripterygium wilfordii, Euphorbia fischeriana, Euphorbia lathyris, Euphorbia kansui, Daphne genkwa, Pseudolarix kaempferi and Brucea javanica, triterpenoids of Melia toosendan, steroids of Periploca sepium, Paris polyphylla and Venenum Bufonis, and arsenic compounds including Arsenicum and Realgar. By comparing their related phytochemistry, toxic effects and the recent advances in understanding the mechanisms of action, this review puts forward some ideals and examples about how to increase antitumour activity and/or reduce the side effects experienced with Chinese medicine.