Author(s): Caleb Hoffman, Jackson Sandberg
Mentor(s): Jessica Pullan, Kaitlin Dailey
Institution SUU
Current treatments for pancreatic tumors have had little impact on mortality rates over the last fifty years, with the five-year survival rate remaining a mere 13%. One of the distinct challenges to treating pancreatic tumors is the avascular nature of solid-state tumors. Without vascular access, it is nearly impossible to effectively deliver therapies to tumors through passive diffusion such as is used by traditional therapeutic approaches. This is particularly true for pancreatic tumors with an extra fibrous layer of desmoplasia. Further, solid-state tumors have uniquely harsh biological microenvironments that degrade and reduce therapeutic efficacy. Clostridium novi-NonToxic (NT), an attenuated bacteria fundamentally incapable of sepsis or bacteremia, has been identified as an avenue to develop novel treatments of pancreatic tumors. Targeted gene modification allows for C. novyi-NT spore coat customization to promote tumor localization and penetration. Pre-clinical development of C. novyi-NT therapeutics requires establishing and standardizing methods of tracking biodistribution and localization in vivo. To date, little is known regarding the chemical composition of the C. novyi-NT surface, and thus little is known regarding the efficacy of traditional staining protocols. Such methods are critical to evaluate and quantitatively measure biodistribution, clearance, and the resulting immunological responses. The aim of this study is to evaluate carboxyfluorescein succinimidyl ester (CFSE, also known as fluorescein) and Nile Red, a common microbiological dye, to optimize staining procedures and begin to form a more robust understanding of the C. novyi-NT surface moieties as well as their interaction with the innate and adaptive immune system.