An electrochemical signal-on apta-cyto-sensor for quantitation of circulating human MDA-MB-231 breast cancer cells by transduction of electro-deposited non-spherical nanoparticles of gold.

A highly simple, sensitive, specific and low-cost electrochemical apta-cyto-sensor for determination of circulating human MDA-MB-231 breast cancer cells was fabricated. Non-spherical nanoparticles of gold were electro-deposited in the presence of ethosuximide as a shape directing and size controlling agent. The nanoparticles had dimensions ranging 50-150 nm, and covered the underlying surface with a roughness factor of 8.03. The Non-spherical nanoparticles were then employed as the apta-cyto-sensor transducer. A 83-mer DNA aptamer that is specific to capturing the cell surface proteins was immobilized on the transducer surface, and binding with the cells was followed using the ferro/ferricyanide redox marker. The aptamer was immobilized within ∼200 min on the transducer surface. The cells were quantified with an equation of regression of ΔIp(µA) = (1.028 ±â€¯0.027) log (C (cell mL-1)) + (0.2199 ±â€¯0.0944), a sensitivity of 1.028 µA (log (concentration / cell mL-1))-1 and a quantitation limit of 2 cell mL-1, in a concentration range of 5 to 2 × 106 cell mL-1. The apta-cyto-sensor selectivity was also evaluated toward AsPC-1, Calu-6, HeLa, MCF-7 and melanoma B16/F10 cell lines. The apta-cyto-sensor had a fabrication reproducibility of 4.2%, regeneration capability of 5.1%, a stability of 35 days, and a potential application for the detection of MDA-MB-231 cells in the spiked blood serum samples with a sensitivity of 0.8975 µA (log (concentration / cell mL-1))-1 and a quantitation limit of 5 cell mL-1, in a concentration range of 10 to 1 × 103 cell mL-1. The apta-cyto-sensor would be applicable for breast cancer diagnosis at early stage.

Evaluation of a self-nanoemulsifying docetaxel delivery system.

A self-nanoemulsifying drug delivery system (SNEDDS) was developed as a novel route to enhance the efficacy of docetaxel lipophilic drug. SNEDDS comprised ethyl oleate, Tween 80 and poly(ethylene glycol) 600, as oil, surfactant and co-surfactant, and formed stabilized monodispersed oil nanodroplets upon dilution in water. SNEDDS represented encapsulation efficiency and loading capacity of 21.4 and 52.7%, respectively. The docetaxel release profile from the drug-loaded SNEDDS was recorded, its effectiveness against MCF-7 cell line was investigated, and an IC50 value of 0.98 ± 0.05 µg mL-1 was attained. The drug-loaded SNEDDS was administrated in rats, and the pharmacokinetic parameters of maximum concentration of 22.2 ± 0.8 µg mL-1, time to attain this maximum concentration of 230 min, and area under the curve of 1.71 ± 0.18 µg min mL-1 were obtained. The developed SNEDDS formulation can be represented as an alternative to docetaxel administration.