ABSTRACT
INTRODUCTION TO NEAR INFRARED FLUORESCENCE BIOIMAGING Near infrared fluorescence (NIRF) bioimaging, capable of imaging the whole body of small animals in vivo, now reveals the interrelatedness of numerous nanosystems with internal biological environments in the fields of drug delivery and molecular imaging (1,2). Traditional drug delivery nanosystems are coordinated with numerous active moieties including drugs, imaging probes, targeting moieties, antibodies, glycoproteins, peptides, receptor-binding ligands, and aptamers, etc. (2,3). Therefore, studying the in vivo characteristics is very important for understanding the interaction between nanosystems and biological environments. Direct visualization by NIRF bioimaging affords noninvasive real-time monitoring of preferential localization resulting from the interaction of these targeting moieties. Recently, the development of new bioimaging systems and imaging probes allows NIRF bioimaging to detect molecular events, actions of specific molecules, and protein recognition down to the molecular level. These specific identifications can be displayed as an amplified signal at localized body sites, presenting the functional status of target diseases. NIRF bioimaging with spatial and temporal resolution in vivo allows for the assessment of biodistribution, the targeting efficacy of drug carriers and imaging probes via the guidance of passive, active, and activatable molecular targeting. In this chapter, numerous applications of NIRF bioimaging characterizing nanosystems in drug delivery and molecular imaging are reviewed, and strategies of nanosystems are classified for NIRF bioimaging.
