RESUMO
Enhanced cellular toxicity was observed using X-ray irradiated nanoparticle drug carriers (NDC) consisting of doxorubicin (DOX) conjugated to DNA strands attached to the surface of gold nanoparticles. Kinetic studies showed that X-rays, acting as a triggering modality, generated reactive oxygen species to break DNA strands and release DOX.
Assuntos
Antibióticos Antineoplásicos/química , Doxorrubicina/química , Portadores de Fármacos/química , Nanopartículas Metálicas/química , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/toxicidade , Neoplasias da Mama/tratamento farmacológico , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , DNA/metabolismo , Doxorrubicina/administração & dosagem , Doxorrubicina/toxicidade , Feminino , Ouro/química , Humanos , Células MCF-7 , Espécies Reativas de Oxigênio/metabolismo , Raios XRESUMO
We report here a new phenomenon of dynamic enhancement of chemical reactions by nanomaterials under hard X-ray irradiation. The nanomaterials were gold and platinum nanoparticles, and the chemical reaction employed was the hydroxylation of coumarin carboxylic acid. The reaction yield was enhanced 2000 times over that predicted on the basis of the absorption of X-rays only by the nanoparticles, and the enhancement was found for the first time to depend on the X-ray dose rate. The maximum turnover frequency was measured at 1 × 10(-4) s(-1) Gy(-1). We call this process chemical enhancement, which is defined as the increased yield of a chemical reaction due to the chemical properties of the added materials. The chemical enhancement described here is believed to be ubiquitous and may significantly alter the outcome of chemical reactions under X-ray irradiation with the assistance of nanomaterials.