Hak Soo Choi, PhD

My research focuses on the development of novel tissue- and organ-specific theranostic agents for diagnosing, staging, and treating human diseases, including cancers and inflammatory diseases. A particular area of interest is tumor-targeted fluorophores, which enable image-guided surgery by specifically visualizing target tissue with high optical properties while avoiding nonspecific uptake in normal background tissues. Over the past decade, we have systematically explored the relationship among nanoparticle hydrodynamic diameter, shape, charge, and hydrophobicity, as well as small molecule contrast agents, on in vivo biodistribution and clearance (Nature Biotech. 2007, Nano Lett. 2009, Angew Chem Int Ed. 2011).

Using invisible near-infrared (NIR) fluorescence and machine learning modeling, we have delineated the relationship among key independent variables that dictate biodistribution and tissue-specific targeting in areas such as lung and sentinel lymph nodes (Nature Biotech. 2010), human prostate cancers (Nature Nanotech. 2010), and human melanomas (Nature Biotech. 2013). Another area of focus is targeting endocrine glands and their tumors. We have achieved specific targeting of the thyroid/parathyroid glands (Nature Medicine, 2015), pancreas (Theranostics, 2014), thymus, pituitary gland (anterior/posterior separately), and adrenal glands (manuscripts in preparation/review). Additionally, we have developed tissue-specific targeted fluorophores for lymph nodes (Theranostics, 2014), bone and cartilage (Angew Chem Int Ed. 2014), kidneys, liver, lungs, spleen, salivary glands, brown fat, seminal vesicle, and prostate (manuscripts in preparation).

Regenerative medicine with tissue-engineered scaffolds is another area of interest, and we have developed biodegradable NIR scaffolds and cellular trafficking systems for longitudinally monitoring tissue regeneration (Sci Rep. 2013, Biomed Mater. 2013, Bioact Mater 2023). Currently, using dual-channel intraoperative imaging systems, we aim to simultaneously target cancerous tissue/vasculature/nerve (tumors), cardiovascular diseases, and bone/cartilage/inflammation (rheumatoid arthritis) with different colors, laying the foundation for clinical translation to image-guided interventions.