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Managing advanced colon cancer is challenging, requiring targeted therapies. This study presents a novel nanoconjugate system, HA-CMD@ETP-MLT-NCs, designed to deliver etoposide (ETP) specifically to colon cancer cells. The system consists of Hyaluronic Acid (HA)-Functionalized Carboxymethyl Dextran (CMD) coated with Melatonin (MLT). The nanoconjugates showed good stability, with a zeta potential of -29.90 mV and a particle size of 199.1 nm. They achieved an 80.3 % yield and a high drug entrapment efficiency of 93.4 %. In vitro release studies demonstrated pH-dependent drug release, with 73.4 % released at pH 5.5 (tumour-like environment) and 42.6 % at pH 7.4 (normal tissue) over 24 h. The nanoconjugates improved cellular uptake, induced apoptosis, and reduced reactive oxygen species (ROS) in HCT116 colon cancer cells. Flow cytometry showed a significant decrease in ROS levels, and lipid peroxidation inhibition increased to 56.67 %. These findings suggest that HA-CMD@ETP-MLT-NCs enhance etoposide delivery and reduce side effects. Further in vivo studies and clinical trials are needed to confirm its therapeutic potential., Competing Interests: Declaration of competing interest Authors declare there are no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Present research work reports the synthesis of Gellan gum (Gg) and methacrylic acid (MA) based grafted hydrogels (Gg-cl-poly(MA)) crosslinked using N, N'- methylene-bis-acrylamide (MBA) and the evaluation of their efficiency to be used as a sustained drug delivery carrier for anticancer drug i.e., etoposide. Various characterization techniques like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) confirmed the grafting of Gg with MA and the formation of crosslinked Gg-cl-poly(MA) hydrogel polymer. The synthesized hydrogel showed pH-dependent swelling properties and exhibited a maximum swelling capacity of 867 % under optimized environmental conditions. The Gg-cl-poly(MA) was biocompatible and non-cytotoxic, which was confirmed by the hemolytic and cytotoxic tests. The release dynamics of etoposide from the Gg-cl-poly(MA) polymer matrix was checked under specific physiological conditions. Drug release was found to be significantly higher in the acidic medium, followed by the neutral and alkaline medium. This clearly indicated that etoposide drug release through synthesized hydrogel was stomach-specific and it is effective for the treatment of stomach cancer. The release mechanism of the etoposide drug was a Fickian-type diffusion mechanism in the acidic medium and a non-Fickian-type diffusion mechanism in the neutral and alkaline medium. The release profile of the etoposide was best fitted to the first-order rate model. The results showed that the synthesized hydrogel (i.e., Gg-cl-poly(MA)) was biocompatible, non-toxic, and could be used for the treatment of stomach cancer., Competing Interests: Declaration of competing interest There is no conflict of interest regarding this manuscript., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Lung cancer has a high incidence rate and a low cure rate, hence the urgent need for effective treatment methods. Current lung cancer drugs have several drawbacks, including low specificity, poor targeting, drug resistance, and irreversible damage to normal tissues. Therefore, there is a need to develop a safe and effective new drug that can target and kill tumor cells. In this study, we combined nanotechnology and biotechnology to develop a CD133 ligand-modified etoposide-liposome complex (Lipo@ETP-CD133) for targeted therapy of lung cancer. The CD133 ligand targeted lung cancer stem cells, causing the composite material to aggregate at the tumor site, where high levels of ETP liposomes could exert a strong tumor-killing effect. Our research results demonstrated that this nano-drug had efficient targeting and tumor-killing effects, indicating its potential for clinical application., (© 2024 American Institute of Chemical Engineers.)

Cholesterol-rich nanoemulsion (LDE) can carry chemotherapeutic agents in the circulation and can concentrate those agents in the neoplastic and inflammatory tissues. This method improves the biodistribution of the drug and reduces toxicity. However, the structural stability of LDE particles, without or with associated drugs, has not been extensively investigated. The aim of the present study is to investigate the structural stability of LDE and LDE associated to paclitaxel, etoposide or methotrexate in aqueous solution over time by small-angle X-ray scattering (SAXS and Ultra SAXS) and dynamic light scattering (DLS). The results show that LDE and LDE associated with those chemotherapeutic agents had reproducible and stable particle diameter, physical structure, and aggregation behavior over 3-month observation period. As estimated from both DLS and Ultra-SAXS methods, performed at pre-established intervals, the average particle diameter of LDE alone was approx. 32 nm, of LDE-paclitaxel was 31 nm, of LDE-methotrexate was 35 nm and of LDE-etoposide was 36 nm. Ultra-SAXS analysis showed that LDE nanoparticles were quasi-spherical, and SAXS showed that drug molecules inside the particles showed a layered-like organization. Formulations of LDE with associated PTX, ETO or MTX were successfully tested in animal experiments and in patients with cancer or with cardiovascular disease, showing markedly low toxicity, good tolerability and possible superior pharmacological action. Our results may be useful for ensuing clinical trials of this novel Nanomedicine tool, by strengthening the knowledge of the structural aspects of those LDE formulations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Neuroblastoma is a pediatric tumor that originates during embryonic development and progresses into aggressive tumors, primarily affecting children under two years old. Many patients are diagnosed as high-risk and undergo chemotherapy, often leading to short- and long-term toxicities. Nanomedicine offers a promising solution to enhance drug efficacy and improve physical properties. In this study, lipid-based nanomedicines were developed with an average size of 140 nm, achieving a high encapsulation efficiency of over 90% for the anticancer drug etoposide. Then, cytotoxicity and apoptosis-inducing effects of these etoposide nanomedicines were assessed in vitro using human cell lines, both cancerous and non-cancerous. The results demonstrated that etoposide nanomedicines exhibited high toxicity and selectively induced apoptosis only in cancerous cells.Next, the biosafety of these nanomedicines in C. elegans, a model organism, was evaluated by measuring survival, body size, and the effect on dividing cells. The findings showed that the nanomedicines had a safer profile than the free etoposide in this model. Notably, nanomedicines exerted etoposide's antiproliferative effect only in highly proliferative germline cells. Therefore, the developed nanomedicines hold promise as safe drug delivery systems for etoposide, potentially leading to an improved therapeutic index for neuroblastoma treatment., (© 2024. The Author(s).)

Herein, we constructed the branch-shaped SiO 2 /nano GO (nGO)/Fe 3 O 4 /selenium quantum dots (QDs) (SeQDs) nanoparticles (SGF/SeQDs) embodying magnetism, fluorescence, and microwave stimulus response properties to enhance the performance of releasing drugs. The SGF/SeQDs composite was characterized by technologies including powder X-ray diffraction, transmission electron microscopy, infrared spectroscopy, etc. In the nanoparticles, the branch-shaped SiO 2 provides a large specific surface area, nGO as the dielectric loss-style material promotes microwave-absorbing performance, and the Fe 3 O 4 serves as a magnetic targeting agent and microwave absorber. Integrating nGO and Fe 3 O 4 could further strengthen the microwave absorption of the entire composite; selenium features both fluorescence and anticancer effects. The synthesized nanoparticles as carriers exhibited a branch-like mesoporous sphere of ∼260 nm, a specific surface area of 258.57 m 2 g -1 , a saturation magnetization of 24.59 emu g -1 , and good microwave thermal conversion performance that the temperature was elevated from 25 to 70 °C under microwave irradiation. These physical characteristics, including large pore volume (5.30 nm), high specific surface area, and fibrous morphology, are in favor of loading drugs. Meanwhile, the cumulative etoposide (VP16) loading rate of the nanoparticles reached to 21 wt % after 360 min. The noncovalent interaction between the VP16 and SGF/SeQDs was mainly the hydrogen-bonding effect during the loading process. Furthermore, the drug release rates at 180 min were up to 81.46, 61.92, and 56.84 wt % at pH 4, 5, and 7, respectively. At 25, 37, and 50 °C, the rates of drug release reach 25.40, 56.84, and 65.32 wt %, respectively. After microwave stimulation at pH 7, the rate of releasing drug increased distinctly from 56.84 to 71.74 wt % compared to that of nonmicrowave irradiation. Cytotoxicity tests manifested that the carrier had good biocompatibility. Therefore, the nanoparticles are looking forward to paving one platform for further applications in biomedicine and drug delivery systems.

Nanofibrous scaffolds have emerged as promising candidates for localized drug delivery systems in the treatment of cutaneous cancers. In this study, we prepared an electrospun nanofibrous scaffold incorporating 5-fluorouracil (5-FU) and etoposide (ETP) for chemotherapy targeting melanoma cutaneous cancer. The scaffold was composed of polyvinyl alcohol (PVA) and chitosan (CS), prepared via the electrospinning process and loaded with the chemotherapeutic agents. We conducted relevant physicochemical characterizations, assessed cytotoxicity, and evaluated apoptosis against melanoma A375 cells. The prepared 5-FU/ETP co-loaded PVA/CS scaffold exhibited nanofibers (NFs) with an average diameter of 321 ± 61 nm, defect-free and homogenous morphology. FTIR spectroscopy confirmed successful incorporation of chemotherapeutics into the scaffold. Additionally, the scaffold demonstrated a hydrophilic surface, proper mechanical strength, high porosity, and efficient liquid absorption capacity. Notably, sustained and controlled drug release was observed from the nanofibrous scaffold. Furthermore, the scaffold significantly increased cytotoxicity (95%) and apoptosis (74%) in A375 melanoma cells. Consequently, the prepared 5-FU/ETP co-loaded PVA/CS nanofibrous scaffold holds promise as a valuable system for localized eradication of cutaneous melanoma tumors and mitigation of adverse drug reactions associated with chemotherapy., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

T-type calcium channels are considered potential drug targets to combat cancer. Combining T-type calcium channel blockers with conventional chemotherapy drugs represents a promising strategy towards successful cancer treatment. From this perspective, we report in this study the design and synthesis of a novel series of N3-sustituted dihydropyrimidines (DHPMs) as anticancer adjuvants to cisplatin (Cis) and etoposide (Eto). Full spectral characterization of the new compounds was done using FT-IR, 1 H NMR, 13 C NMR, and HRMS. Structure elucidation was confirmed by 2D NMR 1 H-H COSY, HSQC and NOESY experiments. Novel derivatives were tested for their Ca 2+ channel blocking activity by employing the whole cell patch-clamp technique. Results demonstrated that most compounds were potential T-type calcium channel blockers with the triazole-based C12 and C13 being the most selective agents against Ca V 3.2 channel. Further electrophysiological studies demonstrated that C12 and C13 inhibited Ca V 3.2 currents with respective affinity of 2.26 and 1.27 µM, and induced 5 mV hyperpolarizing shifts in the half-inactivation potential. Subsequently, C12 and C13 were evaluated for their anticancer activities alone and in combination with Cis and Eto against A549 and MDA-MB 231 cancer cells. Interestingly, both compounds exhibited potential anticancer effects with IC 50 values < 5 µM. Combination studies revealed that both compounds had synergistic effects (combination index CI < 1) on Cis and Eto through induction of apoptosis (p53 activation and up-regulation of BAX and p21 gene expression). Importantly, in silico physicochemical and ADMET assessment of both compounds revealed their potential drug-like properties with decreased risk of cardiac toxicity. Hence, C12 and C13 are promising anticancer adjuvants through inhibition of Ca V 3.2 T-type calcium channels, thereby serving as eminent leads for further modification., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Colorectal cancer is the third most frequently diagnosed cancer malignancy and the second leading cause of cancer-related deaths worldwide. Therefore, it is of utmost importance to provide new therapeutic options that can improve survival. Sphingomyelin nanosystems (SNs) are a promising type of nanocarriers with potential for association of different types of drugs and, thus, for the development of combination treatments. In this work we propose the chemical modification of uroguanylin, a natural ligand for the Guanylyl Cyclase (GCC) receptor, expressed in metastatic colorectal cancer tumors, to favour its anchoring to SNs (UroGm-SNs). The anti-cancer drug etoposide (Etp) was additionally encapsulated for the development of a combination strategy (UroGm-Etp-SNs). Results from in vitro studies showed that UroGm-Etp-SNs can interact with colorectal cancer cells that express the GCC receptor and mediate an antiproliferative response, which is more remarkable for the drugs in combination. The potential of UroGm-Etp-SNs to treat metastatic colorectal cancer cells was complemented with an in vivo experiment in a xenograft mice model., (© 2021. The Author(s).)

Background: Oral cancer is a significant health problem worldwide. Oral squamous cell carcinoma (OSCC) is a malignant neoplasm of epithelial cells that mostly affects different anatomical sites in the head and neck and derives from the squamous epithelium or displays similar morphological characteristics. Generally, OSCC is often the end stage of several changes in the stratified squamous epithelium, which begin as epithelial dysplasia and progress by breaking the basement membrane and invading adjacent tissues. Several plant-based drugs with potent anti-cancer effects are considered inexpensive treatments with limited side effects for cancer and other diseases., Objective: The aim of this review is to explore whether some Brazilian plant extracts or constituents exhibit anti-tumorigenic activity or have a cytotoxic effect on human oral carcinoma cells., Methods: Briefly, OSCC and several metabolites derived from Brazilian plants (i.e., flavonoids, vinblastine, irinotecan, etoposide and paclitaxel) were used as keywords to search the literature on PubMed, GenBank and GeneCards., Results: The results showed that these five chemical compounds found in Cerrado Biome plants exhibit anti-neoplastic effects. Evaluating the compounds revealed that they play a main role in the regulation of cell proliferation., Conclusion: Preserving and utilising the biodiversity of our planet, especially in unique ecosystems, such as the Cerrado Biome, may prove essential to preserving and promoting human health in modern contexts., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

We developed a new strategy to overcome the MDR of etoposide using self-assembling nanofibers. Compared with the original etoposide, the inhibitory activity of Nap-GFFpYK-etoposide1/2 against murine Lewis lung cancer or breast cancer cells was increased 10 times, and 20 times on these cells with artificially overexpressed MDR1. Our method to synthesize and separate etoposide isomers provides a new strategy for the modification of this drug.

Glioblastoma is a malignant brain tumour with a median survival of 14.6 months from diagnosis. Despite maximal surgical resection and concurrent chemoradiotherapy, reoccurrence is inevitable. To try combating the disease at a stage of low residual tumour burden immediately post-surgery, we propose a localised drug delivery system comprising of a spray device, bioadhesive hydrogel (pectin) and drug nanocrystals coated with polylactic acid-polyethylene glycol (NCPPs), to be administered directly into brain parenchyma adjacent to the surgical cavity. We have repurposed pectin for use within the brain, showing in vitro and in vivo biocompatibility, bio-adhesion to mammalian brain and gelling at physiological brain calcium concentrations. Etoposide and olaparib NCPPs with high drug loading have shown in vitro stability and drug release over 120 h. Pluronic F127 stabilised NCPPs to ensure successful spraying, as determined by dynamic light scattering and transmission electron microscopy. Successful delivery of Cy5-labelled NCPPs was demonstrated in a large ex vivo mammalian brain, with NCPP present in the tissue surrounding the resection cavity. Our data collectively demonstrates the pre-clinical development of a novel localised delivery device based on a sprayable hydrogel containing therapeutic NCPPs, amenable for translation to intracranial surgical resection models for the treatment of malignant brain tumours., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

In this study, a system for oral delivery of etoposide (ETP) was designed to avoid the problems associated with low and variable bioavailability of a commercially available ETP emulsion comprised of polyethylene glycol, glycerol, and citric acid anhydrous. ETP was complexed with low-molecular-weight methylcellulose (ETP/LMC) and loaded into a water-in-oil-in-water multiple nanoemulsion to formulate an ETP/LMC-nanoemulsion (ELNE). To further enhance the oral bioavailability, an ionic complex formed by anionic lipid 1,2-didecanoyl-sn-glycero-3-phosphate (sodium salt) and cationic N α -deoxycholyl-l-lysyl-methylester was incorporated into ELNE, yielding ELNE#7. As expected, ELNE#7 showed 4.07- and 2.25-fold increases in artificial membrane and Caco-2/HT29-MTX-E12 permeability ( P app ), respectively, resulting in 224% greater oral bioavailability compared with the commercially available ETP emulsion. In contrast, inhibition of clathrin- and caveola-mediated endocytosis, macropinocytosis, and bile acid transporters by chlorpromazine, genistein, amiloride, and actinomycin D in Caco-2/HT-29-MTX-E12 monolayers reduced the P app by 45.0%, 20.5%, 28.8%, and 31.1%, respectively. These findings suggest that these routes play important roles in enhancing the oral absorption of ELNE#7. In addition, our mechanistic study suggested that P-glycoprotein did not have an inhibitory effect on the permeation of ELNE#7. Notably, ELNE#7 showed significantly enhanced toxicity in LLC and A549 cells compared with ETP-E. These observations support the improved oral absorption of ETP in ELNE#7, suggesting that it is a better alternative than ETP emulsion.

Etoposide is a widely-used anticancer agent that targets human type II topoisomerases. Evidence suggests that metabolism of etoposide in myeloid progenitor cells is associated with translocations involved in leukemia development. Previous studies suggest halogenation at the C-2' position of etoposide reduces metabolism. Halogens were introduced into the C-2' position by electrophilic aromatic halogenation onto etoposide (ETOP, 1), podophyllotoxin (PPT, 2), and 4-dimethylepipodophyllotoxin (DMEP, 3), and to bridge the gap of knowledge regarding the activity of these metabolically stable analogs. Five halogenated analogs (6-10) were synthesized. Analogs 8-10 displayed variable ability to inhibit DNA relaxation. Analog 9 was the only analog to show concentration-dependent enhancement of Top2-mediated DNA cleavage. Dose response assay results indicated that 8 and 10 were most effective at decreasing the viability of HCT-116 and A549 cancer cell lines in culture. Flow cytometry with 8 and 10 in HCT-116 cells provide evidence of sub-G1 cell populations indicative of apoptosis. Taken together, these results indicate C-2' halogenation of etoposide and its precursors, although metabolically stable, decreases overall activity relative to etoposide., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Prostate cancer is among the leading causes of death worldwide because its metastatic form is a deadly disease. Therefore, the development of new chemotherapeutics is of immense importance. Nanoparticle technology seems to provide diverse options in this regard. Therefore, poly(N-isopropylacrylamide) (PNIPAM) coated superparamagnetic iron oxide nanoparticles (SPION) loaded with Etoposide were prepared in small sizes (57 nm) and with 3.5 % drug content to improve the efficiency of Etoposide in prostate cancer therapy. Sustained release of the drug was achieved, which found to be sensitive to low pH and high temperature. The anti-growth activity of SPION-PNIPAM-Etoposide formulation against metastatic prostate cancer cells (PC-3, LNCaP) were investigated by SRB assay, then, confirmed by ATP assay. Mode of cell death was evaluated by using flow cytometry analyses. A significant improvement of nanoformulated drug was observed at 5-10 μg/ml doses of the drug in both cell lines. More importantly, this formulation enhanced the cytotoxic effect of Etoposide on PC-3 cells, which is considered more resistant to Etoposide than LNCaP and reduced the IC 50 value by 55 % reaching to 4.5 μg drug/ml, which is a very significant improvement in the literature. It was clearly shown that nanoformulated drug provided about 3-fold increases in caspase-dependent early apoptotic cells in PC-3 cells. The novel formulation seems to successfully cause cell death of especially PC-3 metastatic prostate cancer cells. It should therefore be taken into consideration for further animal studies as a novel potent anticancer agent., (© 2020 Wiley-VHCA AG, Zurich, Switzerland.)

Introduction: Etoposide refers to a derivative of podophyllotoxin, which plays an important role in the treatment of cancer due to its prominent anti-tumor effect. As a BCS IV drug, etoposide exhibits insufficient aqueous solubility and permeability, thereby limiting its oral absorption. To enhance the oral bioavailability of etoposide, this study developed an amorphous nanopowder., Methods: Based on preliminary screening and experimental design, the stabilizer and preparation process of etoposide nanosuspension were explored. Subsequently, using a Box-Behnken design, the effects of independent factors (ultrasonication time, ratio of two phases and stabilizer concentration) on response variables (particle size and polydispersity index) were studied, and then the formulation was optimized. Finally, nanosuspension was further freeze dried with 1% of mannitol resulting in the formation of etoposide amorphous nanopowder., Results: The optimized etoposide nanopowder showed as spherical particles with an average particle size and polydispersity index of 211.7 ± 10.4 nm and 0.125 ± 0.028. X-ray powder diffraction and differential scanning calorimetry confirmed the ETO in the nanopowder was amorphous. Compared with coarse powder and physical mixture, etoposide nanopowder achieved significantly enhanced saturated solubility and dissolution in various pH environments. The C max and AUC 0-t of etoposide nanopowder after oral administration in rats were respectively 2.21 and 2.13 times higher than the crude etoposide suspension. Additionally, the T max value of nanopowder was 0.25 h, compared with 0.5 h of reference group., Discussion: In the present study, the optimized amorphous nanopowder could significantly facilitate the dissolution and oral absorption of etoposide and might act as an effective delivery method to enhance its oral bioavailability., Competing Interests: The authors report no conflicts of interest for this work., (© 2020 Wang et al.)

In this paper, a novel strategy in the application of the parallel factor analysis (PARAFAC) to a four-way voltammetric dataset was improved to evidence the interaction of etoposide (ETO) and calf thymus deoxyribonucleic acid (DNA) to determine the ETO-DNA binding constant. PARAFAC is one of the most commonly used techniques applicable to the decomposition of higher-order data arrays to focus on features of interest and provides a different resolution of the chemical problem of interest. Under optimized conditions, peak current data of a seven-sample set containing DNA in the range of 2.0-90.0 µM in the presence of ETO at a constant concentration (10 µM) at five different pHs were recorded as a function of potential and frequency and then arranged as a four-dimensional array. The characteristic curves of ETO and ETO-DNA complex were monitored from the potential, frequency, pH, and DNA concentration profiles obtained by PARAFAC decomposition of the fourth-order array. The binding constant, which is one of the principal parameters for the estimation of drug-DNA interaction and mechanism, was computed from the DNA concentration profile. The consequence of drug-DNA binding constant (K = 1.26 × 10 6 ) indicated that there was a significant interaction between ETO and DNA with the intercalation mechanism., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

It has been suggested that oral absorption of low-permeable P-glycoprotein (P-gp) substrates can be increased through saturation of P-gp. For BCS class IV drug substances, saturating P-gp is challenging due to low aqueous solubility. The present study investigated if the BCS IV drug substance etoposide could be solubilized to a concentration saturating P-gp after oral administration. A formulation consisting of 10% (w/v) of pluronic® F-127 and polyvinylpyrrolidone/vinyl acetate (PVP/VA), and 57% (v/v) ethanol enhanced etoposide's solubility approximately 100 times (16 mg mL -1 ) compared to its aqueous solubility. In vitro, this formulation was stable upon dilution in simulated intestinal fluid. In male Sprague-Dawley rats, oral administration of increasing solubilized etoposide doses using the formulation matrix increased the AUC 0-∞ of etoposide dose-proportionally but resulted in a lower absolute oral bioavailability (F) and rate of absorption as compared to control. At the highest investigated dose (100 mg kg -1 ), AUC 0-∞ and C max were significantly increased by 2.9- and 1.4-fold, respectively, compared to control dosed at 20 mg kg -1 . A single oral dose of 20 mg kg -1 zosuquidar followed by 20 mg kg -1 oral etoposide increased F 8.6-fold. In conclusion, a stable formulation with improved etoposide solubility was developed, yet the formulation did not result in increased oral bioavailability of etoposide., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Proteins form adducts with nucleic acids in a variety of contexts, and these adducts may be cytotoxic if not repaired. Here we apply a proteomic approach to identification of proteins adducted to DNA or RNA in normally proliferating cells. This approach combines RADAR fractionation of proteins covalently bound to nucleic acids with quantitative mass spectrometry (MS). We demonstrate that "RADAR-MS" can quantify induction of TOP1- or TOP2-DNA adducts in cells treated with topotecan or etoposide, respectively, and also identify intermediates in physiological adduct repair. We validate RADAR-MS for discovery of previously unknown adducts by determining the repertoires of adducted proteins in two different normally proliferating human cell lines, CCRF-CEM T cells and GM639 fibroblasts. These repertoires are significantly similar with one another and exhibit robust correlations in their quantitative profiles (Spearman r = 0.52). A very similar repertoire is identified by the classical approach of CsCl buoyant density gradient centrifugation. We find that in normally proliferating human cells, the repertoire of adducted proteins - the "adductome" - is comprised of a limited number of proteins belonging to specific functional groups, and that it is greatly enriched for histones, HMG proteins and proteins involved in RNA splicing. Treatment with low concentrations of formaldehyde caused little change in the composition of the repertoire of adducted proteins, suggesting that reactive aldehydes generated by ongoing metabolic processes may contribute to protein adduction in normally proliferating cells. The identification of an endogenous adductome highlights the importance of adduct repair in maintaining genomic structure and the potential for deficiencies in adduct repair to contribute to cancer., Competing Interests: Declaration of Competing Interest The authors declare that there is no conflict of interest regarding the publication of this article., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The generic Mylan® etoposide (ETP) has been investigated as an alternative for Etopophos®, in part due to a global shortage of the latter. The generic alternative is different both in its formulation and in its very limited stability (6 h at 25 °C against 4 days for Etopophos®) once reconstituted in ready-to-use chloride or glucose solutions. Its intrinsic stability has been thoroughly studied under various conditions. Two degradation products resulting from hydrolysis were characterized by LC-HR-MS n and supported by density functional theory calculations of the frontier molecular orbitals energies, molecular electrostatic potential mapping, and Mulliken charge analysis. Chemical degradation increases with temperature and can be fitted to a zero order kinetic model with a half-life of 119 days and a kinetic constant of 0.0028 mM day -1 . Precipitation was only observed in solutions at 5 °C and -20 °C indicating that at these temperatures the reconstituted solutions are thermodynamically metastable. In conclusion, ETP at concentrations of 0.68 and 1 mM prepared and stored at 25 °C under good manufacturing practices remained unchanged over a period of 21 days irrespective of the nature of the solvents or the type of container., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Etoposide (ETS), topoisomerase-II inhibitor, is a first-line anticancer therapeutics used in diverse cancer types. However, the therapeutic potential of this molecule has mainly impeded due to its detrimental toxicity profile, unfavorable rejection by the cancer cells due to P-glycoprotein (P-gp) efflux activity, and rapid hepatic clearance through extensive metabolism by Cytochrome-P450. To increase the therapeutic potency without significant adverse effects, the implication of novel ETS-nanoformulation strategies have recommended mainly. Nanomedicine based nanoformulation approaches based on nanoparticles (NPs), dendrimers, carbon-nanotubes (CNTs), liposomes, polymeric micelles, emulsions, dendrimers, solid-lipid NPs, etc offers immense potential opportunities to improve the therapeutic potential of pharmaceutically problematic drugs. This review provides an up-to-date argument on the work done in the field of nanomedicine to resolve pharmacokinetic and pharmacodynamic issues associated with ETS. The review also expounds the progress in regards to the regulatory, patenting and clinical trials related to the innovative formulation aspects of ETS., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: According to the manufacturers, the diluted solution of etoposide should not exceed 0.4 mg/mL because precipitation may occur. For high doses or for patients requiring fluid restrictions, etoposide phosphate may be an option but shortages occurs frequently. The objective of this work was to study the stability of etoposide solutions between 0.38 and 1.75 mg/mL, diluted in 0.9% sodium chloride (0.9% NaCl) or 5% glucose (G5%) in polyolefin bags, stored at 25°C and between 2°C to 8°C, in a 61-day period. This study also observed the impact of an infusion pump on the physical and chemical stability of etoposide solutions., Materials and Method: Chemical stability was analysed at days 0, 9, 16, 21, 28 and 61 by high-performance liquid chromatography. Physical stability was evaluated by visual and subvisual inspection. The action of an infusion pump on solutions was evaluated to verify the impact of the mechanical pumping action on the etoposide solutions. This investigation was performed at day 61, at the end of the study., Results: Etoposide solutions diluted at 0.38, 0.74 and 1.26 mg/mL in G5% and stored at 25°C were stable for 61 days and at 1.75 mg/mL for 28 days. In 0.9% NaCl, etoposide was less stable, with more precipitations observed. The action of an infusion pump has not caused any physical modifications., Conclusion: Storage at 25°C and G5% as diluent are recommended for etoposide high concentration with 61-day stability up to a concentration of 1.26 mg/mL and 28-day stability up to a concentration of 1.75 mg/mL. As a precaution, the use of an administration set with an in-line micro-filter is nevertheless recommended. Storage at 2°C to 8°C and the use of 0.9% NaCl increase the risk of precipitation., Competing Interests: Competing interests: None declared., (© European Association of Hospital Pharmacists 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Tubulin is the biochemical target for several clinically used anticancer drugs as it helps in the formation of mitotic spindle during mitosis stage of cell division. Many of the anti-cancer drugs are known to interact with tubulin and microtubules including some plant alkaloids, such as paclitaxel, etoposide and topotecan. In silico drug design of these molecules were performed prior to testing these drugs in vitro. In silico drug design of these anti-cancer drugs becomes a challenge due to the complex structure of target protein. This challenge was overcome by predicting the structure of the target protein (tubulin) by homology modeling., Methods: In this study, computer aided drug designing approach was applied to predict the suitable docking site in target protein and the interaction of tubulin protein with paclitaxel, etoposide and topotecan was explored by molecular docking using Schrödinger software. Docking score and glide energy were determined with ligands to validate their anticancer properties., Results: The results indicate that etoposide is the best drug for tubulin with a docking score of - 4.916 and glide energy of -46.470 kcal/mol compared to paclitaxel and topotecan., Conclusion: The testing of these drugs in silico provides an alternate to in vitro testing of these molecules on cancer cell lines which is a time and cost intensive process. The in silico study of parameters, such as docking score and glide energy, will help pharmacists in developing new molecules as targets for cancers in a time and cost-effective manner., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Some lactones prevent protein Myb-dependent gene expression., Objective: The object is to calculate inhibitors of Myb-brought genetic manifestation., Methods: Linear quantitative structure-potency relations result expanded, among sesquiterpene lactones of a variety of macrocycles (pseudoguaianolides, guaianolides, eudesmanolides and germacranolides), to establish which part of the molecule constitutes their pharmacophore, and predict their inhibitory potency on Myb-reliant genetic manifestation, which may result helpful as leads for antileukaemic therapies with a new mechanism of action., Results: Several count indices are connected with structure-activity. The α-methylene-γ-lactone ML functional groups increase, whereas OH groups decrease the activity. Hydrophobicity provides to increase cell toxicity. Four counts (ML, number of α, β-unsaturated CO groups, etc.), connected with the number of oxygens, present a positive association, owing to the partial negative charge of oxygen. The s-trans-strans- germacranolide molecule presents maximal potency. The OH groups decrease the potency owing to the positive charge of hydrogen. The numbers of π-systems and atoms, and polarizability increase the potency. Following least squares, every standard error of the coefficients is satisfactory in every expression. The most predictive linear expressions for lactones, pseudoguaianolides and germacranolides are corroborated by leave-group-out cross-validation. Quadratic equations do not make the correlation better., Conclusion: Likely action mechanisms for lactones are argued with a diversity of functional groups in the lactone annulus, including artemisinin with its uncommon macrocycle characteristic, 1,2,4-trioxane cycle (pharmacophoric peroxide linkage -O1-O2- in endoperoxide ring), which results in the foundation for its sole antimalarial potency., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Etoposide is one of the most used first-line chemotherapeutic drugs. However, its application is still limited by its side effects. Herein, we designed a novel H 2 O 2 sensitive prodrug 6YT for selectively releasing the anti-cancer drug etoposide in cancer cells. In this paper, etoposide and a hydrogen peroxide (H 2 O 2 ) sensitive aryl borate ester group were linked by a fluorescent coumarin and finally the prodrug 6YT was generated. The fluorescence of coumarin was quenched before the connected aryl borate ester group was cleaved by H 2 O 2 . However, in the high level H 2 O 2 environment of the tumor, the fluorescence could be activated simultaneously with the release of etoposide, and the drug release state of the prodrug was monitored real-time. With the support of 6YT, we obtained direct and visual evidence of etoposide release in a high H 2 O 2 environment both in cells and zebrafish. The prodrug 6YT was also verified with comparable activity and improved safety with etoposide both in cells and in a mouse model. As a safe and effective prodrug, 6YT is expected to be one of the promising candidates in chemotherapy against cancer.

Introduction and objective: Lung cancer is the most common one in terms of outbreak and mortality. Since most modern treatments have many side effects, finding an effective and alternative therapy seems necessary. The present study aimed to determine the effect of PEGylated liposomal etoposide nanoparticles on the lung cancer (A-549 and Calu6 cell lines). Materials and methods: The PEGylated liposomal etoposide nanoparticles were prepared by reverse-phase evaporation method. The particle size and zeta potential of the nanoparticles were measured by Zetasizer. The nanoparticle cytotoxicity was examined by MTT method. The vesicular drug release pattern was examined by dialysis method. The amount of loaded drug and the encapsulation efficiency (EE) was also measured and calculated. Apoptosis test was performed using flow cytometry with Annexin V kit. Results: The mean particle size, size distribution, and zeta potential of PEGylated liposomal etoposide nanoparticles were 122.5 ± 4.8 nm, 0.252 ± 0.12 and -13.7 ± 0.51 mv, respectively. The etoposide release in prepared formulations was detected to be about 15.64% after 50 hr. The cytotoxic effect of etoposide nanoparticles on lung cancer A-549 and Calu6 cell lines showed more anti-tumour activity compared to the free drug used. Conclusion: The results showed that the PEGylated liposomal nanoparticles were used as a suitable nanocarrier for etoposide injection. It was also found that the drug effect on the nanodrug formulations was higher than that of the free drug.

5-Hydroxy-2-phenyl-7-(thiiran-2-ylmethoxy)-4H-chromen-4-one (compound 52) was found as a DNA non-intercalative topo II specific catalytic inhibitor by targeting its ATP-binding domain. Showing changes in interaction with Mg 2+ , it exhibited highly selective properties against the α-isoform with less toxicity, unlike other topo II poisons, such as etoposide.

Temporal and reversible control over protein and cell conjugations holds great potential for traceless release of antibody-drug conjugates (ADCs) on tumor sites as well as on-demand altering or removal of targeting elements on cell surface. We herein developed a bioorthogonal and traceless releasable reaction on proteins and intact cells to fulfill such purposes. A systematic survey of transition metals in catalyzing the bioorthogonal cleavage reactions revealed that copper complexes such as Cu(I)-BTTAA and dual-substituted propargyl (dsPra) or propargyloxycarbonyl (dsProc) moieties offered a bioorthogonal releasable pair for reversible blockage and rescue of primary amines and phenol alcohols on small molecule drugs, protein side chains, as well as intact cell surface. For proof-of-concept, we employed such Cu(I)-BTTAA/dsProc and Cu(I)-BTTAA/dsPra pairs as a "traceless linker" strategy to construct cleavable ADCs to unleash cytotoxic compounds on cancer cells in situ and as a "reversible modification" strategy for cell surface engineering. Furthermore, by coupling with the genetic code expansion strategy, we site-specifically modulated ligand-receptor interactions on live cell membranes. Together, our work expanded the transition-metal-mediated bioorthogonal cleavage tool kit from terminal decaging to internal-linker breakage, which offered a temporal and reversible conjugation strategy on therapeutic proteins and cells.

Etoposide is a widely prescribed anticancer drug that is, however, associated with an increased risk of secondary leukemia. Although the molecular basis underlying the development of these leukemias remains poorly understood, increasing evidence implicates the interaction of etoposide metabolites [i.e., etoposide quinone (EQ)] with topoisomerase II enzymes. However, effects of etoposide quinone on other cellular targets could also be at play. We investigated whether T-cell protein tyrosine phosphatase (TCPTP), a protein tyrosine phosphatase that plays a key role in normal and malignant hematopoiesis through regulation of Janus kinase/signal transducer and activator of transcription signaling, could be a target of EQ. We report here that EQ is an irreversible inhibitor of TCPTP phosphatase (IC 50 = ∼7 μ M, second-order rate inhibition constant of ∼810 M -1 ⋅min -1 ). No inhibition was observed with the parent drug. The inhibition by EQ was found to be due to the formation of a covalent adduct at the catalytic cysteine residue in the active site of TCPTP. Exposure of human hematopoietic cells (HL60 and Jurkat) to EQ led to inhibition of endogenous TCPTP and concomitant increase in STAT1 tyrosine phosphorylation. Our results suggest that in addition to alteration of topoisomerase II functions, EQ could also contribute to etoposide-dependent leukemogenesis through impairment of key hematopoietic signaling enzymes, such as TCPTP., (Copyright © 2019 by The American Society for Pharmacology and Experimental Therapeutics.)

Topoisomerase II (TOP2) relieves torsional stress by forming transient cleavage complex intermediates (TOP2ccs) that contain TOP2-linked DNA breaks (DSBs). While TOP2ccs are normally reversible, they can be "trapped" by chemotherapeutic drugs such as etoposide and subsequently converted into irreversible TOP2-linked DSBs. Here, we have quantified etoposide-induced trapping of TOP2ccs, their conversion into irreversible TOP2-linked DSBs, and their processing during DNA repair genome-wide, as a function of time. We find that while TOP2 chromatin localization and trapping is independent of transcription, it requires pre-existing binding of cohesin to DNA. In contrast, the conversion of trapped TOP2ccs to irreversible DSBs during DNA repair is accelerated 2-fold at transcribed loci relative to non-transcribed loci. This conversion is dependent on proteasomal degradation and TDP2 phosphodiesterase activity. Quantitative modeling shows that only two features of pre-existing chromatin structure-namely, cohesin binding and transcriptional activity-can be used to predict the kinetics of TOP2-induced DSBs., (Published by Elsevier Inc.)

Introduction: During the reconstitution of a drug and during its storage, there are risks of interactions between the drug and the bag used for the preparation. Polyvinyl chloride is a material used in the manufacture of a large part of chemotherapy infusion bags. It is subject to many interactions like sorption of drugs and release of phthalate additives., Material and Methods: Seven anticancer drugs used in pediatric oncology were involved in our study. After reconstitution of the anticancer agents in polyvinyl chloride bags, the adsorption phenomenon between the container and the contents is evaluated by infrared spectroscopy by analyzing the inner surface of the polyvinyl chloride. Subsequently, for the anticancer agents which exhibited an adsorption-container-content, the analysis was carried out by ultraviolet-visible spectrophotometry in order to examine the kinetics of the concentration of reconstituted anticancer drugs., Results: All the polyvinyl chloride bags gave a spectrum identical to the spectrum of the reference bag, except the bags used to reconstitute etoposide whose spectra showed 12 additional peaks. With the absorbances measured by ultraviolet-visible spectrophotometry at different times, the analysis of variance statistical analysis shows that there is a significant difference in absorbances between t 0 and all the other measurement times., Conclusion: This study testifies to the existence of a container-content interaction between etoposide and polyvinyl chloride. Thus, reconstitution of etoposide for intravenous infusion into a polyvinyl chloride bag should be used immediately. For etoposide preparations intended for storage beyond 24 h, it is recommended to use a container other than the polyvinyl chloride bag.

Purpose: Platinum-based chemotherapy, consisting of etoposide and cisplatin (EP), has been the cornerstone of therapy for extensive-stage small-cell lung cancer (ES-SCLC) for decades. Despite the marked initial sensitivity of SCLC to chemotherapy, EP regimens cannot avoid the emergence of drug resistance in clinical practice. With the rise of new chemotherapy regimens in recent years and the primary resistance or insensitivity of ES-SCLC to EP regimens, it is desirable to be able to identify patients with resistant or insensitive ES-SCLC., Methods: The sequencing and drug sensitivity data of SCLC cell lines were provided by The Genomics of Drug Sensitivity in Cancer Project (GDSC). The data regarding sensitivity to etoposide of 54 SCLC cell lines were analyzed, and etoposide-sensitive cell lines and etoposide-resistant cell lines were differentiated according to the IC50 values defined by the GDSC. ROC curve analysis was performed on all mutations and combinations of mutations to select the optimal panel to predict resistance to etoposide., Results: ROC analysis of etoposide resistance revealed that the most significant single gene mutation indicating resistance to etoposide was CSMD3 , and the accuracy of predicting resistance to etoposide proved to be the highest when there was any mutation in CSMD3/PCLO/RYR1/EPB41L3 , area under the curve =0.804 (95% confidence interval: 0.679-0.930, P <0.001 )., Conclusion: This study found that a panel with four genes ( CSMD3, EPB41L3, PCLO, and RYR1 ) can accurately predict sensitivity to etoposide. These findings provide new insights into the overall treatment for patients with ES-SCLC that is resistant or insensitive to etoposide., Competing Interests: The authors report no conflicts of interest in this work.

Background: The EPOCH regimen, consisting of vincristine sulfate, doxorubicin hydrochloride, and etoposide phosphate, is typically administered by continuous infusion over four days to oncology inpatients. If the EPOCH regimen was available to be administered through portable elastomeric pumps, chemotherapy could be transitioned to an outpatient setting, reducing inpatient bed days and overall healthcare costs. However, a lack of stability data for the admixtures in the elastomeric infusion devices currently prevents the transition of the regime to an outpatient setting. The purpose of this study is to determine the physical and chemical stability of the admixture in polyisoprene elastomeric pumps under different storage conditions to support the transition of the EPOCH regime to an outpatient setting., Methods: The physico-chemical stability of three admixtures at a range of clinically relevant concentrations compounded in polyisoprene elastomeric infusors was determined when refrigerated at 2-6℃ over a 14-day period followed by 35℃ up to 7 days in the dark, and under standardized fluorescent light to simulate scenarios in clinical practice., Results: All tested admixtures were compatible and the drugs were stable in the elastomeric infusors for up to 14 days when stored at 2-6℃ followed by 7 days at 35℃ in the dark, with nominal losses of <5%. The major degradant of etoposide phosphate was its active form etoposide. There was no degradation (<1% loss) found when the admixture was exposed to a standardized fluorescent light dose of 80 klux-h (25℃) for 10 h. The temperature and light conditions the infusors were exposed to during the stability study were more severe than the conditions determine during clinical administration., Conclusion: The extended stability of the three infusional admixtures compounded in elastomeric infusion pumps demonstrated herein permits advance preparation and storage of these drugs, reducing pharmacy compounding resources. The demonstrated stability at 35℃ and under light exposure, conditions more severe than those experienced during clinical practice, support continuous infusions for up to seven days from the elastomeric infusors without a loss of potency. The proven stability of the EPOCH regimens in the tested elastomeric infusion device supports the transition of treatment to an outpatient setting which will reduce inpatient bed days and overall healthcare costs.

Aim: High-dose administration of etoposide (VP16) was limited by its poor aqueous solubility and severe systemic toxicity on lymphoma therapy. Herein, a novel VP16-loaded lipid-based nanosuspensions (VP16-LNS) was developed for improving drug solubility, enhancing antitumor effect and reducing systemic toxicity. Materials & methods: VP16-LNS with soya lecithin and D-α-tocopheryl PEG 1000 succinate (TPGS) as stabilizers were prepared by nanoprecipitation method. Results: VP16-LNS exhibited uniform spherical morphology, small particle size and favorable colloidal stability. The concentration of VP16 in VP16-LNS was high enough (1017.67 μg/ml) for high-dose therapy on lymphoma. Moreover, VP16-LNS displayed long blood circulation time, selective intratumoral accumulation, remarkable antitumor effect and upregulated safety. Conclusion: VP16-LNS would be an efficient nanoformulation for clinical intravenous application against lymphoma.

The study of multifunctional polymer micelles combined with chemotherapy due to reduced systemic toxicity and enhanced efficacy has attracted intensive attention. Herein, a multifunctional core-cross-linked hybrid micelle system based on mPEG- b-PGu(BA-TPE) and OCT-PEG- b-PGu(DA-TPE) with pH- and redox-triggered drug release and aggregation-induced emission (AIE) active imaging has been developed for active targeting of neuroendocrine neoplasms (NENs), especially neuroendocrine carcinomas (NECs) with poor prognosis. These micelles showed excellent biocompatibility and stability. After the formation of borate ester bonds, core-cross-linked micelles (CCLMs) showed enhanced emission properties. In addition, etoposide (ETO), one of the most important anticancer drugs of NECs, was loaded into the hydrophobic core of micelles by self-assembly with an average diameter of 274.6 nm and spherical morphology. Octreotide (OCT) conjugated onto the micelles enhanced cellular uptake by receptor-mediated endocytosis. ETO-loaded micelles demonstrated the dual-responsive triggered intracellular drug release and great tumor suppression ability in vitro. Compared with free ETO, ETO-loaded CCLMs exhibited a considerable antitumor effect and significantly reduced side effects. Considering the active tumor targeting, dual-responsive drug release and the AIE effect, the polymer micelle system will be a potential candidate for diagnosis and oncotherapy of NENs.

An integrated microfluidic system combining 1) an optically-induced-dielectrophoresis (ODEP) module for manipulation of drug-containing particles and 2) an ultraviolet (UV) "direct writing" module capable of patterning hydrogels was established herein for automatic formulation of customized digital drug cocktails. Using the ODEP module, the drug-containing particles were assembled by using moving light patterns generated from a digital projector. The hydrogel, poly(ethylene glycol) diacrylate (PEGDA), was used as the medium in the ODEP module such that the assembled drug-containing particles could be UV-cured and consequently encapsulated in "pills" of specific sizes and shapes by using the UV direct writing module. At an optimal ODEP force of 335 pN, which was achieved in a solution of 15% PEGDA in 0.2 M sucrose, it was possible to manipulate and UV-cure the drug-containing particles. Furthermore, with a digital micromirror device inside the UV direct writing module, different UV patterns could be designed and projected, allowing for the digital drug cocktails to be packaged into different shapes in <60 s. As a demonstration, emulsion droplets containing two different anti-cancer drugs were further tested to show the capability of the developed device. This represents an automatic digital drug cocktail formulating device which stands to revolutionize personalized medicine.

Purpose: To investigate the binding potential of newly developed Annexin V-conjugated ultrasmall superparamagnetic iron oxide (V-USPIO) for detection of drug-induced apoptosis in vitro and in vivo., Methods: Apoptotic cells induced by camptothecin were incubated with or without Annexin V-USPIO at a concentration of 0.089 mmol Fe/L in vitro. T 2 values of the two cell suspensions were measured by 0.47T nuclear magnetic resonance (NMR) spectrometer. Tumor-bearing mice were subjected to 1.5T MR scanner at 2 h after intraperitoneal injection of etoposide and cyclophosphamide. Following the pre-contrast T 1 - and T 2 -weighted imaging (0 h), the post-contrast scan was performed at 2, 4, 6 and 24 h after intravenous injection of Annexin V-USPIO (100 μmol Fe/kg). As a control, MRI was also obtained at 4 h after injection of USPIO without Annexin V. The ratio of tumor signal intensity (SI) on post-MRI for that on pre-MRI (Post/Pre-SI ratio) was calculated. After scanning, tumors were resected for pathological analysis to evaluate the distribution of iron and apoptotic cells., Results: The suspension of apoptotic cells incubated with Annexin V-USPIO showed shorter T 2 value than that without it. On T 1 -weighted imaging post/pre-SI ratio at 4 h after injection of Annexin V-USPIO showed 1.46, while after injection of USPIO without Annexin V was 1.17. The similar distribution of iron and apoptotic cells was observed in concordance with high signal intensity area on post-T 1 -weighted imaging., Conclusion: A newly developed Annexin V-USPIO could have the potential for detection of drug-induced apoptosis.

An effective SPR nanosensor based on core-shell nanoparticles (Ag@AuNPs) incorporated hexagonal boron nitride (HBN) nanosheets and molecularly imprinted polymer (MIP) was presented for etoposide (ETO) detection. Scanning electron microscope (SEM), transmission electron microscope (TEM), x-ray diffraction (XRD) method, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) methods were utilized for all characterizations of nanomaterials and polymer surfaces. ETO imprinted SPR nanosensor based on Ag@AuNPs-HBN nanocomposite was developed in the presence of poly(2-hydroxyethyl methacrylate-methacryloylamidoglutamic acid) [p(HEMA-MAGA)]. The results of the study have revealed that 0.001-1.00 ng mL -1 (1.70 × 10 -12 -1.70 × 10 -9 M) and 0.00025 ng mL -1 (4.25 × 10 -13 M) were found as the linearity range and the detection limit (LOD). Furthermore, the prepared SPR nanosensor was examined in terms of stability, repeatability and selectivity. Finally, the imprinted SPR nanosensor was applied to the urine samples having high recovery., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Modification of natural polysaccharides such as chitosan (CS), β‑cyclodextrin (β-CD), and alginic acid offers a promising strategy for the preparation of smart drug carriers, and latest innovations on such carriers are focused on stimuli-responsive biomaterials. In this study, highly hydrophilic three-demensional (3D) porous CS-grafted β-CD (CS-g-β-CD) was prepared through the Williamson ether synthesis reaction with epichlorohydrin (ECH) as the crosslinker and the consequent nucleophilic reaction between the epoxide ring of ECH and the primary amine of CS, which was then characterized by 1 H nuclear ( 1 H NMR), Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), thermogravimetry (TG), and N 2 adsorption/desorption isotherms. When etoposide (VP16), an anti-cancer drug, was encapsulated in the CS-g-β-CD, the encapsulation ratio was up to 73.6%. Finally, the resultant CS-g-β-CD was successfully used as the responsive drug carrier for pH- and thermo-sensitive release of VP16. This work opens a new avenue for the preparation of stimuli-responsive drug carriers with modified natural polysaccharides., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Wheat germ agglutinin (WGA) and folic acid (FA)-grafted methoxy poly(ethylene glycol) (MPEG)‑poly(ε‑caprolactone) (PCL) nanoparticles (WFNPs) were applied to transport anticancer drugs across the blood-brain barrier and treat glioblastoma multiforme (GBM). PCL was copolymerized with MPEG, and MPEG-PCL NPs were stabilized with pluronic F127 using a microemulsion-solvent evaporation technique and crosslinked with WGA and FA. The targeting ability of WFNPs loaded with etoposide (ETO), carmustine (BCNU) and doxorubicin (DOX) was investigated via the binding affinity of drug-loaded NP formulations to N‑acetylglucosamine expressed in human brain microvascular endothelial cells and to folate receptor in malignant U87MG cells. We found that a shorter PCL chain in drug-loaded MPEG-PCL NPs yielded a smaller average size of the particles. An increase in PCL chain length (stronger hydrophobicity) enhanced drug entrapment efficiencies in MPEG-PCL NPs, and reduced drug-releasing rates from NP formulations. In addition, anti-proliferative activity against U87MG cells for the 3 drugs followed the order of WFNPs > FA-grafted NPs > WGA-grafted NPs > MPEG-PCL NPs. Immunofluorescence staining revealed that the ligands of drug-loaded WFNPs connected to N‑acetylglucosamine and folate receptor with the help of surface WGA and FA. WFNPs carrying ETO, BCNU and DOX acted as dual-targeting nanocarriers, and their use can be a promising approach to inhibiting GBM growth in the brain., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The two non-visual subtypes, arrestin-2 and arrestin-3, are ubiquitously expressed and bind hundreds of G protein-coupled receptors. In addition, these arrestins also interact with dozens of non-receptor signaling proteins, including c-Src, ERK and JNK, that regulate cell death and survival. Arrestin-3 facilitates the activation of JNK family kinases, which are important players in the regulation of apoptosis. Here we show that arrestin-3 is specifically cleaved at Asp366, Asp405 and Asp406 by caspases during the apoptotic cell death. This results in the generation of one main cleavage product, arrestin-3-(1-366). The formation of this fragment occurs in a dose-dependent manner with the increase of fraction of apoptotic cells upon etoposide treatment. In contrast to a caspase-resistant mutant (D366/405/406E) the arrestin-3-(1-366) fragment reduces the apoptosis of etoposide-treated cells. We found that caspase cleavage did not affect the binding of the arrestin-3 to JNK3, but prevented facilitation of its activation, in contrast to the caspase-resistant mutant, which facilitated JNK activation similar to WT arrestin-3, likely due to decreased binding of the upstream kinases ASK1 and MKK4/7. The data suggest that caspase-generated arrestin-3-(1-366) prevents the signaling in the ASK1-MKK4/7-JNK1/2/3 cascade and protects cells, thereby suppressing apoptosis., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The targeted or responsive systems are appealing therapeutic platforms for the development of next-generation precision medications. So, we design and prepare acid-controlled release complexes of podophyllotoxin (POD) and etoposide (VP-16) with pH-labile acyclic cucurbit[n]urils, and their characteristics and inclusion complexation behaviors were investigated via fluorescence spectroscopy, nuclear magnetic resonance and X-ray power diffraction. Cells incubated with complexes have been analyzed by high-content analysis (HCA), and cytotoxicity tests have been completed by MTT assay. The results showed that complexes with different binding constants can release the drug substance in the physiological pH environment of cancer cells, maintain good anticancer activity, and have low cytotoxicity. This provides a strategy about targeted and responsive systems of POD and VP-16 for clinical application., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background and Purpose: The biological significance of the multi-site phosphorylation of Bcl-2 at its loop region (T69, S70 and S87) has remained controversial for decades. This is a major obstacle for understanding apoptosis and anti-tumour drug development., Experimental Approach: We established a mathematical model into which a phosphorylation and de-phosphorylation process of Bcl-2 was integrated. Paclitaxel-treated breast cancer cells were used as experimental models. Changes in the kinetics of binding with its critical partners, induced by phosphorylation of Bcl-2 were experimentally obtained by surface plasmon resonance, using a phosphorylation-mimicking mutant EEE-Bcl-2 (T69E, S70E and S87E)., Key Results: Mathematical simulations combined with experimental validation showed that phosphorylation regulates Bcl-2 with different dynamics depending on the extent of Bcl-2 phosphorylation and the phosphorylated Bcl-2-induced changes in binding kinetics. In response to Bcl-2 homology 3 (BH3)-only protein Bmf stress, Bcl-2 phosphorylation switched from diminishing to enhancing the Bcl-2 anti-apoptotic ability with increased phosphorylation of Bcl-2, and the turning point was 50% Bcl-2 phosphorylation induced by 0.2 μM paclitaxel treatment. In contrast, Bcl-2 phosphorylation enhanced the anti-apoptotic ability of Bcl-2 towards other BH3-only proteins Bim, Bad and Puma, throughout the entire phosphorylation procedure., Conclusions and Implications: The model could accurately predict the effects of anti-tumour drugs that involve the Bcl-2 family pathway, as shown with ABT-199 or etoposide., (© 2018 The British Pharmacological Society.)

A new strategy is reported for the synthesis of label-free fluorescent mesoporous silica (MS) by the introduction of fluorescent carbon dots in the MSs (MSCDs) in this work. Etoposide (ETO) loaded MSCDs have been used as a drug model. Carboxymethyl β-cyclodextrin (CβCD) used as a gatekeeper agent was attached to amine-functionalized MSCDs to retain ETO molecules inside the nanocarrier. In order to target the nanocarrier to the site of action, folic acid (FA) was grafted onto the MSCDs surface (FA-CβCD-MSCDs). The in vitro release of an entrapped ETO from the formulation in phosphate buffered saline (PBS) (pH 7.4) and citrate buffer (pH 5.4) was investigated. At neutral pH in PBS, the pores are blocked by CβCD which prevent premature ETO release. However, under the weakly acidic intercellular environment of the tumor, the amide bond can be partially hydrolyzed and consequently lead to the ETO release from the nanocarrier. The targeted and ETO-loaded FA-CβCD-MSCDs showed a higher growth inhibition towards FA-positive HeLa cells compared with FA-negative HepG2 cells, as demonstrated by comparison of in vitro cytotoxicity experiments. In addition, the CDs emission was used for the fluorescent microscopic imaging. Moreover, molecular docking and molecular dynamics simulations (MDS) were applied to examine the interactions of ETO molecules with the topoisomerase II (Top II). ETO molecules bind Top II with overall binding constants of 3.08 × 10 10  M -1 , according to docking results. Based on MDS results, ETO-Top II complex is formed through hydrophobic interactions., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Etoposide is an anticancer drug that acts by inducing topoisomerase II-mediated DNA cleavage. Despite its wide use, etoposide is associated with some very serious side-effects including the development of treatment-related acute myelogenous leukemias. Etoposide targets both human topoisomerase IIα and IIβ. However, the contributions of the two enzyme isoforms to the therapeutic vs. leukemogenic properties of the drug are unclear. In order to develop an etoposide-based drug with specificity for cancer cells that express an active polyamine transport system, the sugar moiety of the drug has been replaced with a polyamine tail. To analyze the effects of this substitution on the specificity of hybrid molecules toward the two enzyme isoforms, we analyzed the activity of a series of etoposide-polyamine hybrids toward human topoisomerase IIα and IIβ. All of the compounds displayed an ability to induce enzyme-mediated DNA cleavage that was comparable to or higher than that of etoposide. Relative to the parent drug, the hybrid compounds displayed substantially higher activity toward topoisomerase IIβ than IIα. Modeling studies suggest that the enhanced specificity may result from interactions with Gln778 in topoisomerase IIβ. The corresponding residue in the α isoform is a methionine., (Published by Elsevier Ltd.)

Aim: A Nano-in-Nano approach was exploited to facilitate incorporation of the chemotherapeutic drug etoposide (ETP) as nanosuspension, synergistically with berberine (BER) into hydrophilic albumin nanoparticles (HSA NPs)., Methods: For maximal tumor targeting, HSA was modified with mannose and phenyl-boronic acid. Furthermore, different crosslinkers were investigated for sustained release of water soluble BER from HSA NPs., Results: The elaborated dual-targeted HSA NPs (216.2 nm) were spherical with high BER and ETP entrapment efficiency (69.5 and 87.6%, respectively) and loading (10.52 and 14.04%, respectively). The NPs exhibited sequential release pattern for both ETP and BER (51.55 and 34.33% over 72 h, respectively). Phenyl-boronic acid/mannose-HSA NPs demonstrated powerful cytotoxicity against A549 lung cancer cells (IC 50 : 12.4 μg/ml) correlated to enhanced cellular internalization. Dual-targeted NPs displayed 9.77-fold higher caspase-3 level and 3.5-fold lower VEGF level than positive control mice., Conclusion: Dual-targeted Nano-in-Nano albumin carriers could be beneficial for parenteral ETP/BER delivery to lung cancer.

Background: Silk is a biocompatible and biodegradable material, able to self-assemble into different morphological structures. Silk structures may be used for many biomedical applications, including carriers for drug delivery. The authors designed a new bioengineered spider silk protein, EMS2, and examined its property as a carrier of chemotherapeutics., Materials and Methods: To obtain EMS protein, the MS2 silk monomer (that was based on the MaSp2 spidroin of Nephila clavipes ) was modified by the addition of a glutamic acid residue. Both bioengineered silks were produced in an Escherichia coli expression system and purified by thermal method. The silk spheres were produced by mixing with potassium phosphate buffer. The physical properties of the particles were characterized using scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, and zeta potential measurements. The MTT assay was used to examine the cytotoxicity of spheres. The loading and release profiles of drugs were studied spectrophotometrically., Results: The bioengineered silk variant, EMS2, was constructed, produced, and purified. The EMS2 silk retained the self-assembly property and formed spheres. The spheres made of EMS2 and MS2 silks were not cytotoxic and had a similar secondary structure content but differed in morphology and zeta potential values; EMS2 particles were more negatively charged than MS2 particles. Independently of the loading method (pre- or post-loading), the loading of drugs into EMS2 spheres was more efficient than the loading into MS2 spheres. The advantageous loading efficiency and release rate made EMS2 spheres a good choice to deliver neutral etoposide (ETP). Despite the high loading efficiency of positively charged mitoxantrone (MTX) into EMS2 particles, the fast release rate made EMS2 unsuitable for the delivery of this drug. A faster release rate from EMS2 particles compared to MS2 particles was observed for positively charged doxorubicin (DOX)., Conclusion: By modifying its sequence, silk affinity for drugs can be controlled., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

A multifaceted therapeutic platform has been proposed for controlled delivery of Etoposide (ETS) leading to a synergistic advantage of maximum therapeutic efficacy and diminished toxicity. A state of the art pH responsive nanoparticles (NPs) MSNs-PAA consisting of mesoporous silica nanoparticles core and polymeric shell layers, were developed for controlled release of model anti-cancer drug ETS. Graft onto strategy was employed and amination served as an interim step, laying a vital foundation for functionalization of the MSN core with hydrophilic and pH responsive polyacrylic acid (PAA). MCM-41-PAA were investigated as carriers for loading and regulated release of ETS at different pH for the first time. The PAA-MSNs contained 20.19% grafted PAA as exhibited by thermogravimetric analysis (TGA), which enormously improved the solubility of ETS in aqueous media. The synthesized PAA-MSNs were characterized by various techniques viz, SEM-EDS, TEM, BET, FT-IR and powder XRD. ETS was effectively loaded into the channels of PAA-MSN via electrostatic interactions. The cumulative release was much rapid at extracellular tumor (6.8) and endosomal pH (5.5) than that of blood pH (7.4). Hemolysis study was done for the prepared NPs. MTT assay results showed that the drug-loaded ETS-MCM-41-PAA NPs were more cytotoxic to both prostate cancer cells namely PC-3 and LNCaP than free ETS, which was attributed to their slow and sustained release behavior. The above results confirmed that PAA-MSN hold a great potential as pH responsive carriers with promising future in the field of cancer therapy.

In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously determine the anticancer drugs etoposide and paclitaxel in mouse plasma and tissues including liver, kidney, lung, heart, spleen and brain. The analytes were extracted from the matrices of interest by liquid-liquid extraction using methyl tert-butyl ether-dichloromethane (1:1, v/v). Chromatographic separation was achieved on an Ultimate XB-C 18 column (100 × 2.1 mm, 3 μm) at 40°C and the total run time was 4 min under a gradient elution. Ionization was conducted using electrospray ionization in the positive mode. Stable isotope etoposide-d3 and docetaxel were used as the internal standards. The lower limit of quantitation (LLOQ) of etoposide was 1 ng/g tissue for all tissues and 0.5 ng/mL for plasma. The LLOQ of paclitaxel was 0.4 ng/g tissue and 0.2 ng/mL for all tissues and plasma, respectively. The coefficients of correlation for all of the analytes in the tissues and plasma were >0.99. Both intra- and inter-day accuracy and precision were satisfactory. This method was successfully applied to measure plasma and tissue drug concentrations in mice treated with etoposide and paclitaxel-loaded self-microemulsifying drug-delivery systems., (Copyright © 2018 John Wiley & Sons, Ltd.)

The aim of the present work was to investigate the ability of nonionic surfactants to increase the oral absorption of the P-glycoprotein substrate etoposide in vitro and in vivo. Intestinal absorption was investigated by studying bidirectional permeability of etoposide across filter-grown Caco-2 and MDCKII MDR1 cell monolayers. The oral absorption of etoposide was investigated in wild type (WT) and mdr1a deficient (KO) Sprague-Dawley rats. In cell cultures, polysorbate 20 (PS20) decreased P-glycoprotein mediated efflux of etoposide. When PS20 and etoposide were co-administered to WT rats, the oral absorption of etoposide increased significantly in the presence of 5 and 25% (v/v) PS20. However, in KO rats, the exposure of etoposide after oral co-administration with 5% PS20 was similar to control. Unexpectedly, co-administration of etoposide with 25% PS20 significantly reduced the absorption fraction of etoposide in mdr1a KO rats. In vitro dialysis studies performed on PS20-containing etoposide solutions suggested that the reduced bioavailability may be due to etoposide retention in PS20 micelles and/or through increased viscosity. In conclusion, PS20 increases oral bioavailability of etoposide through inhibition of P-glycoprotein. However, the use of the excipient may be challenged by etoposide retention at higher concentrations., (Copyright © 2018 Elsevier B.V. All rights reserved.)