RESUMEN
Efficient drug delivery is critical to therapy. Using electron microscopy, X-ray, and light microscopy, we have characterized functionalized superparamagnetic iron oxide (SPIO) nanoparticles, and determined their ability for rapid entry and release of the cancer drug doxorubicin in human pancreatic cancer cells. Dextran-coated SPIO nanoparticle ferrofluid, functionalized with the red-autofluorescing doxorubicin and the green-fluorescent dye fluorescein isothiocyanate as a reporter, enables tracking the intracellular nanoparticle transport and drug release. This engineered nanoparticle enables a >20 fold rapid entry and release of the drug in human pancreatic cancer cells, holding therapeutic potential as an advanced drug delivery and imaging platform. The low extracellular pH of most tumors precluding the entry of a number of weakly basic drugs such as doxorubicin, conferring drug resistance, can now be overcome.
Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas de Magnetita/química , Nanopartículas/metabolismo , Antibióticos Antineoplásicos/metabolismo , Línea Celular Tumoral , Doxorrubicina/metabolismo , Compuestos Férricos/química , Fluoresceína-5-Isotiocianato/química , Fluoresceína-5-Isotiocianato/metabolismo , Fluorescencia , Humanos , Nanopartículas de Magnetita/estadística & datos numéricos , Nanopartículas/química , Neoplasias Pancreáticas/tratamiento farmacológicoRESUMEN
A gold nanoparticle (GNP) probe-based assay (GNPA) modified from the bio-barcode assay (BCA) was developed for ultrasensitive detection of ricin, a potential biothreat agent. In the GNPA, a chain of ricin was captured by a GNP probe coated with polyclonal antibodies and single-stranded signal DNA. A magnetic microparticle (MMP) probe coated with ricin A chain monoclonal antibody was then added to form an immuno-complex. After being magnetically separated, the immuno-complex containing the single-stranded signal DNA was characterized by PCR and real-time PCR. A detection limit of 10(-2) fg/ml was determined for the ricin A chain; this is eight orders of magnitude more sensitive than that achieved with an ELISA and two orders more sensitive than that obtained with the BCA. The coefficients of variation (CV) of the intra- and inter-assay values ranged from 3.82-6.46%. The results here show that this novel assay is an ultrasensitive method for detection of ricin proteins and may be suitable for the ultrasensitive detection of other proteins.