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Anticancer therapies with cisplatin and volasertib (BI-6727) were monitored by fluorescence lifetime imaging microscopy (FLIM) in live SK-Mel-2 melanoma cells. A CdSe/ZnS quantum dot functionalized with a peptide containing D-penicillamine and histidine (CdSe/ZnS-PH) was used as intracellular pH fluorescent probe. A faster cytosol acidification was observed for cells treated with cisplatin when compared to volasertib. The first changes in the intracellular pH were found after 2 hours of treatment with cisplatin and 8 hours with volasertib. Additionally, the relationship between cytosol acidification and apoptosis was investigated using an innovative methodology based on time-resolved fluorescence measurements. Similar low percentages of apoptotic cells were observed after short incubation periods (2 - 8 hours) with both drugs. In contrast, late apoptosis and death were found for a large fraction of cells during 24-hour incubation with cisplatin but not volasertib. Thus, the early acidification observed in cisplatin treatment could accelerate apoptosis and cell death. Despite volasertib treatment shows slower mechanism of action than cisplatin, similar inhibitory effects were found for both drugs at longer incubation periods (72 hours). This study proves the potential of CdSe/ZnS-PH nanoparticle as a fluorescence lifetime probe in the study of the mechanism of action of antitumor drugs., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ivan Bravo reports financial support was provided by Junta de Comunidades de Castilla-La Mancha. Andres Garzon-Ruiz reports financial support was provided by Spain Ministry of Science and Innovation. If there are other authors, they 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 © 2024 Elsevier B.V. All rights reserved.)

The photothermal/photodynamic synergistic therapy is a promising tumor treatment, but developing nanosystems that achieve synchronous photothermal/photodynamic functions is still quite challenging. Here, we use a simple method to synthesize molybdenum selenide nanoparticles (MoSe 2 NPs) with a photothermal effect as a carrier, and load a photosensitizer ICG to form a nanosystem (MoSe 2 @ICG-PDA-HA)with dual photothermal/photodynamic functions under near-infrared irradiation. In addition, the surface modification of the nanosystem with acid-responsive release polydopamine (PDA) and tumor-targeted hyaluronic acid (HA) enhanced the stability of the photosensitizer ICG and the accumulation of ICG at tumor sites. The multicellular sphere assay simulated solid tumors and demonstrated that MoSe 2 @ICG-PDA-HA could significantly inhibit the 4T1 cell growth. The anti-tumor experiments in tumor-bearing mice showed that MoSe 2 @ICG-PDA-HA not only significantly inhibited the growth of 4T1 subcutaneous tumors, but also inhibited their metastasis. This study presented a nanosystem that could improve the photostability of optical materials and enhance the photothermal/photodynamic synergy effect, providing a new idea for finding a way to effectively treat breast cancer., 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.)

Fluorescent inorganic quantum dots are highly promising for biomedical applications as sensing and imaging agents. However, the low internalization of the quantum dots, as well as for most of the nanoparticles, by living cells is a critical issue which should be solved for success in translational research. In order to increase the internalization rate of inorganic CdSe/ZnS quantum dots, they were functionalized with a fluorinated organic ligand. The fluorinated quantum dots displayed an enhanced surface activity, leading to a significant cell uptake as demonstrated by in vitro experiments with HeLa cells. We combined the experimental and computational results of Langmuir monolayers of the DPPC phospholipid as a model cell membrane with in vitro experiments for analyzing the mechanism of internalization of the fluorinated CdSe/ZnS quantum dots. Surface pressure-molecular area isotherms suggested that the physical state of the DPPC molecules was greatly affected by the quantum dots. UV-vis reflection spectroscopy and Brewster Angle Microscopy as in situ experimental techniques further confirmed the significant surface concentration of quantum dots. The disruption of the ordering of the DPPC molecules was assessed. Computer simulations offered detailed insights in the interaction between the quantum dots and the phospholipid, pointing to a significant modification of the physical state of the hydrophobic region of the phospholipid molecules. This phenomenon appeared as the most relevant step in the internalization mechanism of the fluorinated quantum dots by cells. Thus, this work sheds light on the role of fluorine on the surface of inorganic nanoparticles for enhancing their cellular uptake., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Selenium nanoparticles (SeNPs) as a new replacement source of other Se forms applied in nutritional supplements have been associated with health-related issues. Pectin (PEC) as a well-known food-grade polysaccharide has been considered as a potential soft template for the preparation and stabilization of SeNPs in aqueous medium. In this study, therefore, PEC was used as a stabilizer and dispersing agent to form well-dispersed and stable SeNPs under a simple redox system of selenite and ascorbic acid. Se/PEC ratios significantly affected the color of the suspension, particle size, and surface morphology of the as-prepared SeNPs in the presence of PEC. PEC-SeNPs with a Se/PEC ratio of 1:2 appeared amorphous and exhibited a well-dispersed and stable spherical structure with an average size of ∼41 nm, which corresponds to the strong hydrogen bonding between the hydroxyl groups of PEC and SeNPs. The PEC-SeNPs (Se/PEC = 1:2) remained highly stable in different acidic solutions for at least 1 month. Small and highly stable PEC-SeNPs (Se/PEC = 1:2) possessed the strongest DPPH radical scavenging ability and antioxidant capacity among the evaluated PEC-SeNPs. They also possessed a low cytotoxic activity against cancer cells (SPCA-1 and HeLa) and normal cells (RWPE-1) in vitro. These findings suggested that pectin as a surface decorator could be effectively used to improve the stability and antioxidant capacity of SeNPs remarkably., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Selenium nanoparticles have at present picked up a vital prospect in the field of medicine, due to their inquisitive properties when compared to other selenium compounds. They are comparatively better as anticancer, non- toxic, and biocompatible operators than selenite (SeO 3 -2 ) and selenate (SeO 4 -2 ) compounds. The mechanism behind the anticancerous property of SeNps is primarily due to the invasion of the apoptotic pathways and cell cycle arrest, which eventually lead to blockage of other pathways. Conjugation or surface modification of selenium nanoparticles enhances its anticancer adequacy by antibiotics, biomolecules or phytochemical compounds present in microbes or plants. Selenium, being an integral part of enzyme like glutathione peroxidase (GPx) and other seleno-chemical compounds, can enhance the chemotherapeutic activity by acting as a functional division of redox center and inhibiting the tissues from cellular damage by ROS. SeNps can open ways to new regular strategies for treating illnesses like malignancy, and this audit expresses the reasons why these nano measured medications can be the following huge achievement as chemotherapeutic operators., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Chitosan-stabilized selenium nanoparticles (CTS-SeNPs) were prepared through the reduction of selenite acid with ascorbic acid. The optimal synthesis conditions of CTS-SeNPs were obtained by orthogonal experiments. Besides, the size, morphology and stability of CTS-SeNPs were characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM) and dynamic light scattering (DLS). The results showed that, the CTS-SeNPs with diameter of about 54 nm could be obtained under the optimal conditions (temperature of 25 °C, reaction time of 2 h, Vc concentration of 0.04 M and the CTS concentration of 1.0 mg/mL). CTS-SeNPs were uniform spherical and could be stable for approximately 60 days at 4 °C. Further, the antidiabetic activities of CTS-SeNPs in streptozotocin (STZ)-induced diabetic mice were investigated as well. The results revealed that CTS-SeNPs at a dose of 2.0 mg Se/kg bw exhibited higher antidiabetic activity than other doses of CTS-SeNPs and other selenium compounds with the same selenium content., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Selenium (Se) incorporated into organic frameworks has demonstrated anticancer activity against several cancer types. One of the drawbacks of most of these constructs is their poor solubility and bioavailability, which can be overcome with the use of suitable nanocarriers. We have synthesized a series of 5-substituted amide selenodiazoles, based on the parent structure of ebselen, an organoselenium drug with proven cytoprotective activity, and solubilized them in polymeric micelles of poloxamines, poly(ethylene oxide)-poly(propylene oxide) X-shaped tetrablock-copolymers. Scattering methods (SANS and DLS) were employed to characterize the micellar nanocarriers. MTT biological evaluation highlights the selectivity of the Se-compounds towards cancer cells, with MCF-7 standing as the most responsive line. The alkylation of the heterocycle with a 12-carbon hydrophobic tail displays the highest activity, showing a 100-fold increase with respect to ebselen. This compound also exhibits the greatest increase in solubility in poloxamine micelles, overall resulting in a one-fold increase in activity with respect to the non-formulated form, making it a hit compound for further optimization., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Resistance of cancer to radiotherapy and/or chemotherapy is one of the important reasons of clinical treatment failure and recurrence. Chemoradiation is an optional method to over-coming of radioresistance and chemoresistance. Selenium nanoparticles (SeNPs) with special chemical and physical properties, has been identified as a novel nanocarrier and therapy agent with broad-spectrum anticancer activities due to generate ROS in cells. Herein, X-ray responsive selenium nanoparticles were facilely fabricated by using PEG as surface decorator and template. This nanosystem (PEG-SeNPs) demonstrated X-ray responsive property that was attributed to its amorphous characteristic. Interestingly, the nanosystem demonstrated significant radiosensitization effects with X-ray. Specifically, co-treatment of cancer cells with PEG-SeNPs and X-ray significantly and synergistically enhanced the cells growth inhibition through induction of cell apoptosis, as evidenced by DNA fragmentation and activation of caspase-3. In the cell model, we found that internalized nanoparticles could degrade upon X-ray exposure, which further confirm the X-ray responsive property of the nanoparticles. Moreover, the nanosystem could significantly induced intracellular ROS generation in a time-dependent manner, which peaked at about 40min and gradually decreased thereafter. As a results, ROS overproduction led to mitochondria fragmentation and the cell apoptosis. Taken together, this study provides a novel strategy for rational design and facile synthesis of chemo-radio therapeutic radiosensitization nanomaterials., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In the present work, the CdSe/ZnS hydrophobic quantum dots were embedded within the polyelectrolyte nanocapsules. The core of the capsules, which consists of a mixture of the linseed oil with chloroform, was prepared using the spontaneous emulsification technique. The obtained emulsions were stabilized with lecithin and encapsulated using the layer-by-layer (LbL) adsorption of polyelectrolytes. The pair of biocompatible polyelectrolytes was used: the cationic poly-l-lysine hydrobromide (PLL) together with the anionic poly-d-glutamic acid sodium salt. The saturation LbL method, which is based on the stepwise formation of consecutive layers on the initial emulsion without the intermediate rinsing step, was applied to form the capsule shells. Their growth was evidenced by the capsule size and electrophoretic mobility measurements. The emulsion and the capsules were deposited on a mica surface and the deposit topology was examined by the means of atomic force microscopy (AFM). The presence of quantum dots within the oil cores was confirmed by recording the fluorescent spectra of the samples containing CdSe/ZnS. In order to evaluate cytotoxicity of the capsules, their influence on the viability of mouse embryonic fibroblasts was examined using the MTT test, followed by optical-microscope observation of morphology of the cells after hematoxylin-eosin staining., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In vitro antiproliferative effects of selenium nanoparticles (nanoSe(0), 10-40 μmol/L) on HeLa (human cervical carcinoma) cells and MDA-MB-231 (human breast carcinoma) cells were examined by optical microscopic inspection and MTT assay in the present study. The nanoSe(0) effectively inhibited the growth of MDA-MB-231 cells and HeLa cells in a dose-dependent manner. The morphology analysis with atomic force microscope showed that the HeLa cells treated with 10 μmol/L nanoSe(0) were rough and shrunken with truncated lamellipodia at terminal part of the cells. Flow cytometric analysis demonstrated that HeLa cells were arrested at S phase of the cell cycle after exposed to nanoSe(0) (10 μmol/L). Taken together, our results suggested that nanoSe(0) may be more helpful in cancer chemoprevention as a potential anticancer drug., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Surface chemistry and molecular interaction mechanisms of Cryptosporidium parvum oocysts with a ZnSe internal reflection element (IRE) surface were investigated as a function of pH and ionic strength in NaCl and CaCl(2) background electrolyte using in-situ ATR-FTIR spectroscopy. Since the surface properties of oocysts play an important role in adhesion behavior, the effects of surface modifications that are commonly employed to inactivate the pathogen for laboratory studies, including viable (control), formalin-, and heat-inactivation, were also examined. The ATR-FTIR spectra of oocyst surfaces exhibit amide, carboxylate, phosphate, and polysaccharide functional groups. Results indicate that changes in solution chemistry strongly impact oocyst adhesion behavior in aqueous systems. Increasing ionic strength from 1 to 100 mM or decreasing pH from 9.0 to 3.0 resulted in an increase in oocyst adhesion to the IRE surface as measured by IR absorbance. For equivalent ionic strength, the adhesion rate was found to be independent of CaCl(2) versus NaCl electrolyte solution, but was increased following formalin and heat treatments. This latter effect correlated with molecular changes reflected in spectral data. The ratio of amide I:amide II band intensities increased, and sugar ring vibrations at 1023 cm(-1) became sharper and more intense following formalin treatment. Similar changes in the polysaccharide region were observed following heat treatment, and protein secondary structure was also altered from mainly parallel beta-sheet to anti-parallel beta-sheet conformation.