Detection of a fluorescent-labeled avidin-nucleic acid nanoassembly by confocal laser endomicroscopy in the microvasculature of chronically inflamed intestinal mucosa

Abstract

Inflammatory bowel diseases are chronic gastrointestinal pathologies causing great discomfort in both children and adults. The pathogenesis of inflammatory bowel diseases is not yet fully understood and their diagnosis and treatment are often challenging. Nanoparticle-based strategies have been tested in local drug delivery to the inflamed colon. Here, we have investigated the use of the novel avidin-nucleic acid nanoassembly (ANANAS) platform as a potential diagnostic carrier in an experimental model of inflammatory bowel diseases. Fluorescent- labeled ANANAS nanoparticles were administered to mice with chemically induced chronic inflammation of the large intestine. Localization of mucosal nanoparticles was assessed in vivo by dual-band confocal laser endomicroscopy. This technique enables characterization of the mucosal microvasculature and crypt architecture at subcellular resolution. Intravascular nanoparticle distribution was observed in the inflamed mucosa but not in healthy controls, demonstrating the utility of the combination of ANANAS and confocal laser endomicroscopy for highlighting intestinal inflammatory conditions. The specific localization of ANANAS in inflamed tissues supports the potential of this platform as a targeted carrier for bioactive moieties in the treatment of inflammatory bowel disease.

The principles and applications of avidin-based nanoparticles in drug delivery and diagnosis

“…This assembly forms a toroidal structure, which is further complexed with biotinylated polyethylene glycol. [63] Due to the excellent pharmacokinetic properties of avidin, after in vivo administration, fluorescently labeled ANANAS nanoparticles showed substantial subcellular internalization in the mucosal vasculature. This enabled the localization of nanoparticles at the target site, whereas no accumulation was observed in healthy tissues.…”

A New ELISA Using the ANANAS Technology Showing High Sensitivity to diagnose the Bovine Rhinotracheitis from Individual Sera to Pooled Milk

“…When used in combination with analyte-specific biotinylated antibodies and a biotinylated signal generating moiety, they bring to the immobilized analyte higher signal than monomeric avidin so that a strong signal amplification is generated ( Fig 1 ). Compared to poly-HRPs, the ANANAS technology is more versatile as the reagents can be integrated with many signal generating technologies, including fluorescence, chemiluminescence or enzyme-generated colour [ 6 , 10 , 11 ].…”