RESUMO
Aggregated ß-amyloid (Aß) is widely considered as a key factor in triggering progressive loss of neuronal function in Alzheimer's disease (AD), so targeting and inhibiting Aß aggregation has been broadly recognized as an efficient therapeutic strategy for curing AD. Herein, we designed and prepared an organic platinum-substituted polyoxometalate, (Me4 N)3 [PW11 O40 (SiC3 H6 NH2 )2 PtCl2 ] (abbreviated as PtII -PW11 ) for inhibiting Aß42 aggregation. The mechanism of inhibition on Aß42 aggregation by PtII -PW11 was attributed to the multiple interactions of PtII -PW11 with Aß42 including coordination interaction of Pt2+ in PtII -PW11 with amino group in Aß42 , electrostatic attraction, hydrogen bonding and van der Waals force. In cell-based assay, PtII -PW11 displayed remarkable neuroprotective effect for Aß42 aggregation-induced cytotoxicity, leading to increase of cell viability from 49 % to 67 % at a dosage of 8â µm. More importantly, the PtII -PW11 greatly reduced Aß deposition and rescued memory loss in APP/PS1 transgenic AD model mice without noticeable cytotoxicity, demonstrating its potential as drugs for AD treatment.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacologia , Doença de Alzheimer/metabolismo , Animais , Dicroísmo Circular , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Modelos Animais de Doenças , Humanos , Masculino , Aprendizagem em Labirinto , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia Eletrônica de Transmissão , Eletricidade Estática , Compostos de Tungstênio/químicaRESUMO
A carbon nanotube (CNT) based nanoarchitecture is developed for rapid, sensitive and specific detection of cancer cells by using real time electrical impedance sensing. The sensor is constructed with carbon nanotube (CNT) multilayers and EpCAM (epithelial cell adhesion molecule) antibodies, which are assembled on an indium tin oxide (ITO) electrode surface. The binding of tumor cells to EpCAM antibodies causes increase of the electron-transfer resistance. The electrochemical impedance of the prepared biosensors is linear with the logarithm of concentration of the liver cancer cell line (HepG2) within the concentration range of 10 to 10(5) cells per mL. The detection limit for HepG2 cells is 5 cells per mL. The proposed impedimetric sensing devices allow for sensitive and specific detection of cancer cells in whole-blood samples without any sample pretreatment steps.