2025 AIChE Annual Meeting

(190e) Modification of Iron Oxide Nanoparticles for Contrast-Enhanced MRI

Authors

Allan David, Auburn University
Today, medical errors have emerged as a leading cause of mortality, with 10-26% of these deaths attributed to diagnostic errors. These diagnostic errors, including misdiagnosis, missed diagnosis, and delayed diagnosis are complex and have profound consequences on patient outcomes. The impact of these errors underscores the critical need for advancements in diagnostic tools. Magnetic Resonance Imaging (MRI) is a powerful imaging tool widely used for the early diagnosis of damaged or diseased tissue due to its noninvasive mechanism. High-resolution imaging of soft tissue enables more accurate disease detection, thereby improving treatment outcomes. However, MRI often does not generate enough contrast to distinguish between tissues, necessitating the use of contrast agents to enhance its sensitivity and increase image resolution. This project involves the modification of magnetic nanoparticles, specifically iron oxide nanoparticles (IONPs), for use as contrast agents in contrast-enhanced MRI. Using IONPs as contrast agents is advantageous because iron, being abundant in the body, is safer than other magnetic elements and possesses intrinsic magnetic properties at cellular and molecular levels.

By tuning these magnetic properties, we can control their interaction with spinning protons within water molecules to enhance their contrast properties. This interaction is crucial because it directly influences the contrast properties of the MRI images, making it easier to distinguish between different tissues. A significant challenge is controlling the microenvironment around the nanoparticle, as it is a complex system. Therefore, this project encompasses the synthesis of IONPs, and the modification of their surface and microenvironment, to effectively tune the local environment in response to the magnetic field.

One of the most crucial characteristics of nanoparticles as imaging agents is their blood circulation time. Enhancing magnetic nanoparticles with liposomes improves biocompatibility, facilitates surface modifications, and promotes evasion of the immune system and clearance by the reticuloendothelial system (RES). Polyethylene glycol (PEG), a synthetic polymer, is commonly used as a surface modifier to impart a "stealth" effect to nanoparticles. PEG exhibits anti-fouling properties that resist interactions with blood and serum proteins. Moreover, it enhances the stability of nanoparticles through steric hindrance, preventing aggregation and reducing the risk of thrombosis. Therefore, encapsulating IONPs in Liposome-PEG minimizes non-specific uptake by macrophages in the RES, resulting in prolonged circulation of the nanoparticles in the system to effectively execute their diagnostic functions.

Preliminary results show that the synthesized nanoparticles exhibit high magnetic properties, characterized by superparamagnetism in their magnetic behavior analysis. These nanoparticles show retained magnetic properties following surface modification and exhibit stability over time along with resistance to macrophage uptake. This combination of features makes them efficient for tissue imaging in MRI.