Differential response of MCF7, MDA-MB-231, and MCF 10A cells to hyperthermia, silver nanoparticles and silver nanoparticle-induced photothermal therapy.

PURPOSE: Silver nanoparticles (Ag NP) can generate heat upon exposure to infrared light. The in vitro response of breast cell lines to Ag NP, both with and without nanoparticle-induced heating was evaluated. MATERIALS AND METHODS: Ag NP heat generation, intracellular silver concentration, and cell viability of MDA-MB-231, MCF7, and MCF 10A breast cells with Ag NP alone, or after exposure to 0.79 or 2.94 W/cm2 of 800 nm light were evaluated. RESULTS: The concentration of Ag NP to induce sufficient heat for cell death, upon exposure to 800 nm light, was 5-250 µg/mL. Clonogenics assay indicates a cytotoxic response of MCF7 (45% decrease) and MDA-MB-231 (80% decrease) cells to 10 µg/mL, whereas MCF 10A had a 25% increase. Without Ag NP, MDA-MB-231 cells were more susceptible to hyperthermia, compared to MCF7 and MCF 10A cells. Clonogenics assay of Ag NP-induced photothermal ablation demonstrated that MCF 10A cells have the highest survival fraction. MCF7 cells had more silver in the cytoplasm, MDA-MB-231 cells had more in the nuclei, and MCF 10A cells had equivalent concentrations in the cytoplasm and nuclei. CONCLUSIONS: Ag NP are effective photothermal agents. A secondary benefit is the differential response of breast cancer cells to Ag NP-induced hyperthermia, due to increased intracellular silver content, compared to non-tumorigenic breast epithelial cells.

A comparative study of the photothermal efficiency of electrically conducting poly(3,4-ethylenedioxythiophene)-based nanomaterials with cancer cells.

The photothermal efficiency of two similar organic nanomaterials, poly(3,4-ethylenedioxythiophene):poly(4-styrene-sulfonate) (PEDOT:PSS) nanoparticles and poly(3,4-ethylenedioxythiophene) (PEDOT) nanotubes, are compared. The PEDOT:PSS nanoparticles ranged from 100-200 nm in diameter, while the PEDOT nanotubes ranged from 200-400 nm in diameter and 4-10 microm in length. By changing the aspect ratio of the PEDOT nanomaterials from a spherical to a tubular shape, interesting differences in the optical and electronic properties of the materials were realized. Because of this, the PEDOT nanotubes were shown to generate on average approximately to 10 degrees C better internal heating for similar concentrations compared to the PEDOT:PSS nanoparticles. Cytotoxicity studies of both nanomaterials showed no significant toxicity towards RKO or HCT116 colorectal cancer cells in the absence of NIR light. The NIR-mediated photothermal efficiency of the PEDOT:PSS nanoparticles and the PEDOT nanotubes were compared in-vitro. A cell viability assay was performed and at the highest concentration (0.1 mg/mL) of nanomaterial, cell survival was close to 20% for the PEDOT:PSS nanoparticles with both RKO and HCT116 cells. Consequently, cell survival for the PEDOT nanotubes was less than 5% for both RKO and HCT116 cells. An in-vitro three dimensional tumor model was assembled using collagen gel tissue phantoms. The depth of heat penetration from the PEDOT nanotubes into the tissue phantoms, along with cell viability of RKO and HCT116 cells was determined and quantified.

Low band gap donor-acceptor conjugated polymer nanoparticles and their NIR-mediated thermal ablation of cancer cells.

Low band gap D-A conjugated PNs consisting of 2-ethylhexyl cyclopentadithiophene co-polymerized with 2,1,3-benzothiadiazole (for nano-PCPDTBT) or 2,1,3-benzoselenadiazole (for nano-PCPDTBSe) have been developed. The PNs are stable in aqueous media and showed no significant toxicity up to 1 mg · mL(-1) . Upon exposure to 808 nm light, the PNs generated temperatures above 50 °C. Photothermal ablation studies of the PNs with RKO and HCT116 colorectal cancer cells were performed. At concentrations above 100 µg · mL(-1) for nano-PCPDTBSe, cell viability was less than 20%, while at concentrations above 62 µg · mL(-1) for nano-PCPDTBT, cell viability was less than 10%. The results of this work demonstrate that low band gap D-A conjugated polymers 1) can be formed into nanoparticles that are stable in aqueous media; 2) are non-toxic until stimulated by IR light and 3) have a high photothermal efficiency.

A soluble high molecular weight copolymer of benzo[1,2-b:4,5-b']dithiophene and benzoxadiazole for efficient organic photovoltaics.

The synthesis and characterization of a soluble high molecular weight copolymer based on 4,8-bis(1-pentylhexyloxy)benzo[1,2-b:4,5-b']dithiophene and 2,1,3-benzoxadiazole is presented. High efficiency organic photovoltaic (OPV) devices comprised of this polymer and phenyl-C(71) -butyric acid methyl ester (PC(71) BM) were fabricated by additive processing with 1-chloronapthalene (CN). When the active layer is cast from pristine chlorobenzene (CB), power conversion efficiencies (PCEs) average 1.41%. Our best condition-using 2% chloronapthalene as a solvent additive in CB-results in an average PCE of 5.65%, with a champion efficiency of 6.05%.

Bis(µ-dithieno[3,2-b:2',3'-d]thio-phene-2,6-dicarboxyl-ato-κO:O)bis-[bis-(1,10-phenanthroline-κN,N')cobalt(II)] dimethyl-formamide disolvate.

The asymmetric unit of the title compound, [Co(2)(C(10)H(2)O(4)S(3))(2)(C(12)H(8)N(2))(4)]·2C(3)H(7)NO, contains one half of the formula unit, with the rest generated by inversion. The cobalt ion sits in a slightly distorted octa-hedral environment and is ligated to four N atoms of two 1,10-phenanthroline molecules and to two O atoms of two dithieno[3,2-b:2',3'-d]thio-phene-2,6-dicarb-oxy-l-ate anions. The anions act as bridges between the Co(II) centers.