Design and Synthesis of Functional Nanomaterials Towards Autonomous Theranostics

Photoacoustic imaging (PAI) is an emerging non-invasive, biomedical imaging technique that relies on the molecular absorption of monochromatic light and the detection of generated ultrasound. PAI is used for imaging both the functional and anatomical features of tissues; hence, it can be used in different applications, such as early-stage biopsies, imaging angiogenesis, and sentinel lymph node imaging. PAI can greatly benefit from exogenous contrast agents with high optical absorption in the near-infrared (NIR) range to improve the depth of imaging. However, the current repository of NIR exogenous contrast agents for PAI is limited, especially those that are biocompatible, safe, photostable, and stable in physiological environments. Hence, there is a critical need to develop a safe NIR contrast agent that can be synthesized in a reproducible manner and that is versatile for use in various imaging applications. In this study, we synthesized and characterized an indocyanine green (ICG) dye J-aggregate (JA) contrast agent platform, whose size can be precisely tuned from 120 nm to 1400 nm, can be modified with different functional groups and targeting moieties, such as cell membrane-targeting peptides, and is stable for 48 hours under different in vitro conditions. We further demonstrated the in vitro and in vivo applications of ICG-JA as a PA contrast agent (CA). As previous studies have demonstrated that ICG-JA has therapeutic benefits, our ICG-JA CA platform can also perform both therapeutic and diagnostic functions, making it a prospective theranostic agent. Finally, we functionalized ICG-JA with an enzyme such as urease, which gives them the ability to autonomously propel using the enzyme’s substrate (e.g., urea) as a fuel. We quantified the rate of dispersion of these ICG-JA in a gel diffusion assay, which mimics biological tissues, illustrating their potential use as autonomous theranostic particles.

Author

• Singh, Shrishti

• Diagnostic
• Enhanced Diffusion
• Indocyanine Green
• J-aggregates
• Photoacoustic Imaging
• Theranostics

Identifier

hdl:1920/13910

OAI identifier oai:identifier

oai:MARS:1920/13910