RESUMO
Previous studies have shown that the packaging RNA (pRNA) of bacteriophage phi29 DNA packaging motor folds into a compact structure, constituting a RNA nanoparticle that can be modularized with functional groups as a nanodelivery system. pRNA nanoparticles can also be self-assembled by the bipartite approach without altering folding property. The present study demonstrated that 2'-F-modified pRNA nanoparticles were readily manufactured through this scalable bipartite strategy, featuring total chemical synthesis and permitting diverse functional modularizations. The RNA nanoparticles were chemically and metabolically stable and demonstrated a favorable pharmacokinetic (PK) profile in mice (half-life (T(1/2)): 5-10 hours, clearance (Cl): <0.13 l/kg/hour, volume of distribution (V(d)): 1.2 l/kg). It did not induce an interferon (IFN) response nor did it induce cytokine production in mice. Repeat intravenous administrations in mice up to 30 mg/kg did not result in any toxicity. Fluorescent folate-pRNA nanoparticles efficiently and specifically bound and internalized to folate receptor (FR)-bearing cancer cells in vitro. It also specifically and dose-dependently targeted to FR(+) xenograft tumor in mice with minimal accumulation in normal tissues. This first comprehensive pharmacological study suggests that the pRNA nanoparticle had all the preferred pharmacological features to serve as an efficient nanodelivery platform for broad medical applications.
Assuntos
Nanopartículas/química , RNA Interferente Pequeno/administração & dosagem , RNA Viral/química , RNA/síntese química , RNA/genética , Animais , Bacteriófagos/genética , Citometria de Fluxo , Humanos , Masculino , Camundongos , Camundongos Nus , Microscopia Confocal , RNA/administração & dosagem , RNA/química , RNA Viral/genéticaRESUMO
DNA fingerprinting, PCR and other genomic technologies have recently been used to determine sources of fecal bacteria in waterways. Here, we report on the development of a simple and automated optical method for potential use in Microbial Source Tracking (MST) of E. coli. The method employs laser imaging of bacterial colonies and high-resolution optical scattering image analysis for information extraction and classification. Cross validation is used to statistically evaluate the robustness of the classifiers. The entire image analysis procedure can be fully automated, making this a potentially useful tool for future MST studies.