<mods:mods xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-7.xsd"><mods:titleInfo><mods:title>Magnetic Nanocrystals as MRI Contrast Agents: Role of Size, Shape, and Surface Coating</mods:title></mods:titleInfo><mods:typeOfResource authority="primo">dissertations</mods:typeOfResource><mods:name type="personal"><mods:namePart>Villanova, Jake</mods:namePart><mods:role><mods:roleTerm type="text">creator</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Colvin, Vicki</mods:namePart><mods:role><mods:roleTerm type="text">Advisor</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Shukla, Anita</mods:namePart><mods:role><mods:roleTerm type="text">Reader</mods:roleTerm></mods:role></mods:name><mods:name type="personal"><mods:namePart>Chen, Ou</mods:namePart><mods:role><mods:roleTerm type="text">Reader</mods:roleTerm></mods:role></mods:name><mods:name type="corporate"><mods:namePart>Brown University. Department of Chemistry</mods:namePart><mods:role><mods:roleTerm type="text">sponsor</mods:roleTerm></mods:role></mods:name><mods:originInfo><mods:copyrightDate>2023</mods:copyrightDate></mods:originInfo><mods:physicalDescription><mods:extent>xx, 280 p.</mods:extent><mods:digitalOrigin>born digital</mods:digitalOrigin></mods:physicalDescription><mods:note type="thesis">Thesis (Ph. D.)--Brown University, 2023</mods:note><mods:genre authority="aat">theses</mods:genre><mods:abstract>Approximately half of magnetic resonance imaging (MRI) procedures require intravenously administered contrast agents image enhancement and greater diagnostic precision. The current clinical standard for MRI contrast agents, gadolinium chelates, have proven useful but are limited in their broader applicability by short blood circulation times, non-specific biodistribution, toxicity concerns for patients with kidney disease, and sub-optimal contrast performance (relaxivity). Magnetic nanocrystals, with their readily tunable physiochemical parameters (e.g., composition, size, shape, surface coating), can be designed to overcome these challenges, making them a promising alternative to gadolinium chelates. Here, gadolinium and iron oxide nanocrystals are used to understand and address the different challenges associated with developing T1 and T2 contrast agents – the two major classes of MRI contrast agents. Due to their unique shape, gadolinium oxide nanoplates (GONPs) exhibit exceptional and surface coating dependent T1 relaxivity. Their stable crystal structure, robust surface coatings, and interactions with serum proteins, allow GONPs to be successfully applied in the differentiation of non-alcoholic fatty liver disease (NAFLD). Libraries of iron oxide nanocrystals (IONCs) are then used to systematically understand the relationship between surface coating and T2 relaxivity. Insights about water diffusion from IONC coating thickness and grafting density data provide the basis for a paradigm shift in the rational design of highly sensitive, ‘smart’ T2 contrast agents. Finally, manganese- and rare earth-doped IONC clusters are used to discuss the potential utility of dual T1/T2 and fluorescent MRI contrast agents.</mods:abstract><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/01005780"><mods:topic>Magnetic resonance imaging</mods:topic></mods:subject><mods:subject authority="fast" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/01744350"><mods:topic>Nanomedicine</mods:topic></mods:subject><mods:subject><mods:topic>Nanomaterial</mods:topic></mods:subject><mods:subject><mods:topic>Magnetic Nanoparticle</mods:topic></mods:subject><mods:language><mods:languageTerm authority="iso639-2b">English</mods:languageTerm></mods:language><mods:recordInfo><mods:recordContentSource authority="marcorg">RPB</mods:recordContentSource><mods:recordCreationDate encoding="iso8601">20230207</mods:recordCreationDate></mods:recordInfo></mods:mods>