Toward in vivo detection of hydrogen peroxide with ultrasound molecular imaging.
Biomaterials
; 34(35): 8918-24, 2013 Nov.
Article
em En
| MEDLINE
| ID: mdl-23958028
ABSTRACT
We present a new class of ultrasound molecular imaging agents that extend upon the design of micromotors that are designed to move through fluids by catalyzing hydrogen peroxide (H2O2) and propelling forward by escaping oxygen microbubbles. Micromotor converters require 62 mm of H2O2 to move - 1000-fold higher than is expected in vivo. Here, we aim to prove that ultrasound can detect the expelled microbubbles, to determine the minimum H2O2 concentration needed for microbubble detection, explore alternate designs to detect the H2O2 produced by activated neutrophils and perform preliminary in vivo testing. Oxygen microbubbles were detected by ultrasound at 2.5 mm H2O2. Best results were achieved with a 400-500 nm spherical design with alternating surface coatings of catalase and PSS over a silica core. The lowest detection limit of 10-100 µm was achieved when assays were done in plasma. Using this design, we detected the H2O2 produced by freshly isolated PMA-activated neutrophils allowing their distinction from naïve neutrophils. Finally, we were also able to show that direct injection of these nanospheres into an abscess in vivo enhanced ultrasound signal only when they contained catalase, and only when injected into an abscess, likely because of the elevated levels of H2O2 produced by inflammatory mediators.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ultrassom
/
Imagem Molecular
/
Peróxido de Hidrogênio
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Biomaterials
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos