PVM/MA-shelled selol nanocapsules promote cell cycle arrest in A549 lung adenocarcinoma cells

Background: Selol is an oily mixture of selenitetriacylglycerides that was obtained as a semi-synthetic compound containing selenite. Selol is effective against cancerous cells and less toxic to normal cells compared with inorganic forms of selenite. However, Selol’s hydrophobicity hinders its administration in vivo. Therefore, the present study aimed to produce a formulation of Selol nanocapsules (SPN) and to test its effectiveness against pulmonary adenocarcinoma cells (A549). Results: Nanocapsules were produced through an interfacial nanoprecipitation method. The polymer shell was composed of poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA) copolymer. The obtained nanocapsules were monodisperse and stable. Both free Selol (S) and SPN reduced the viability of A549 cells, whereas S induced a greater reduction in non-tumor cell viability than SPN. The suppressor effect of SPN was primarily associated to the G2/M arrest of the cell cycle, as was corroborated by the down-regulations of the CCNB1 and CDC25C genes. Apoptosis and necrosis were induced by Selol in a discrete percentage of A549 cells. SPN also increased the production of reactive oxygen species, leading to oxidative cellular damage and to the overexpression of the GPX1, CYP1A1, BAX and BCL2 genes. Conclusions: This study presents a stable formulation of PVM/MA-shelled Selol nanocapsules and provides the first demonstration that Selol promotes G2/M arrest in cancerous cells

Dye adsorption on magnetically modified chlorella vulgaris cells

Dried Chiorelia vulgaris ceIls were magnetically modified by contact with water-based magnetic fluid stabilized with perchloric acid in order to prepare a new type of magnetically responsive biocomposite material. This procedure enabled a simple separation of modified ceIls by means of strong permanent magnets. The prepared material was used as a new inexpensive magnetic adsorbent for the removal of water-soluble dyes. MagneticalIy modified cells were characterized by means of magnetic and microscopic methods. Both isolated magnetic nanoparticles and aggregates of particles were present on the ceIl surlace. The prepared material displayed a super-paramagnetic behavior at room temperature, with a transition to a blocked state at Tв ~ 200 K for the applied magnetic field H =50 Oe. Six dyes (aniline blue, Bismarck brown, congo red, crystal violeI, safranin O and Saturn blue LBRR) were used to study the adsorption processo The dyes' adsorption reached equilibrium in approximately 30-120 mino Langmuir isotherms were successfulIy used to fit lhe experimental data. The maximum adsorption capacities ranged between 24.2 (Saturn blue LBRR) and 257.9 (aniline blue) mg of dye per g of dried magneticalIy modified cells. Change of pH can significantly increase lhe adsorption of some dyes. Ferrofluid-modified Chio relia vulgaris ceIls represent an interesting material for furlher study and potential applications

Co-nanoencapsulation of magnetic nanoparticles and selol for breast tumor treatment: in vitro evaluation of cytotoxicity and magnetohyperthermia efficacy

Antitumor activities have been described in selol, a hydrophobic mixture of molecules containing selenium in their structure, and also in maghemite magnetic nanoparticles (MNPs). Both selol and MNPs were co-encapsulated within poly(lactic-co-glycolic acid) (PLGA) nanocapsules for therapeutic purposes. The PLGA-nanocapsules loaded with MNPs and selol were labeled MSE-NC and characterized by transmission and scanning electron microscopy, electrophoretic mobility, photon correlation spectroscopy, presenting a monodisperse profile, and positive charge. The antitumor effect of MSE-NC was evaluated using normal (MCF-10A) and neoplastic (4T1 and MCF-7) breast cell lines. Nanocapsules containing only MNPs or selol were used as control. MTT assay showed that the cytotoxicity induced by MSE-NC was dose and time dependent. Normal cells were less affected than tumor cells. Cell death occurred mainly by apoptosis. Further exposure of MSE-NC treated neoplastic breast cells to an alternating magnetic field increased the antitumor effect of MSE-NC. It was concluded that selol-loaded magnetic PLGA-nanocapsules (MSE-NC) represent an effective magnetic material platform to promote magnetohyperthermia and thus a potential system for antitumor therapy.Rede CON-NANO/CAPESRede CONNANO/CAPESINCTNanobiotechnologia/MCT/CNPqINCT-Nanobiotechnologia/MCT/CNPqFAP-DFFAPDFFAPESPFAPESP [2009/13208-3]DPP/UnBDPP/UnBCNANO/IB/UnBCNANO/IB/UnBPolish State Committee for Scientific ResearchPolish State Committee for Scientific Research [N N 202 166440, N N 405 360639

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO2-coated lanthanide-doped NaYF4 nanoconstructs

Inorganic nanomaterials able to generate reactive oxygen species (ROS) are promising components for modern medical applications. Activated by near-infrared light, up-converting beta-NaYF4 doped with Er3+ - Yb3+ and Tm3+- Yb3+ pair ions nanoparticles (UCNPs), have a wide range of applications in biological imaging as compared to traditional reagents excited by ultra-violet or visible light. We analysed the green-red and the blue-red luminescence to explain the mechanism of the upconversion depended on the surface condition. The influence of SiO2 coating on the cytotoxicity of the as-produced UCNPs towards HeLa cancer cells was reported. We demonstrated a possibility of a direct UCNPs application to photodynamic therapy, without need to attach additional molecules to their surface. The presence of Tm3+ - Yb3+ pair ions, thus ROS generation capability, renders the SiO2 shell coated nanoparticles to become potentially useful theranostic agent

Nanocapsules for the co-delivery of selol and doxorubicin to breast adenocarcinoma 4T1 cells <i>in vitro</i>

<p>Nanocapsules (NCS-DOX) with an oily core of selol and a shell of poly(methyl vinyl ether-co-maleic anhydride) covalently conjugated to doxorubicin were developed. These nanocapsules are spherical, with an average hydrodynamic diameter of about 170 nm, and with negative zeta potential. NCS-DOX effectively co-delivered the selol and the doxorubicin into 4T1 cells and changed the intracellular distribution of DOX from the nuclei to the mitochondria. Moreover, a significantly increased cytotoxicity against 4T1 cells was observed, which is suggestive of additive or synergic effect of selol and doxorubicin. In conclusion, PVM/MA nanocapsules are suitable platforms to co-deliver drugs into cancer cells.</p