Engineered Manganese-Based Nanoparticles as MRI Contrast Agents for Early Tumor Detection

Cancer is a fatal disease, affecting approximately 25% of the population worldwide¹. Given the global impact, early detection of cancer is needed to reduce morbidity and prevent mortality². Unfortunately, not all forms of cancer diagnosis such as blood tests or biopsy can detect the disease during its early stages. Medical imaging has emerged as one of the salient tools for early detection, but not all imaging modalities fit this criterion. Some modalities either offer low penetration depth or spatial resolution while others use radiation for detection, possibly increasing the burden on cancer patients. Magnetic resonance imaging (MRI) circumvents these issues by using non-invasive magnetic field offering unlimited penetration depth and high resolution³. Additionally, MRI provides contrast but with low sensitivity measured by relaxivity r₁, a known stumbling block when it comes to early detection. To overcome low sensitivity, contrast agents such as gadolinium and manganese-based agents are used in conjunction with MRI. Gadolinium has been clinically approved for MRI imaging since the 1980s but suffers from side effects such as brain hypersensitivity, neuronal death and is contraindicated in patients with renal impairment causing nephrogenic systemic failure ⁴. Given these side effects, manganese based-agents have transpired as an alternative to gadolinium for suffering patients. Although safer for patients, manganese-based agents offer lower r₁ values in comparison to gadolinium-based agents, provoking research in improving this value. This talk will focus on enhancing the r₁ values of manganese-based agents by doping manganese with different host materials such as Prussian Blue⁵, clay-like layered double hydroxide⁶ and hydroxy-apatite⁷.

1. www.aicr.org/learn-more-about-cancer/infographics/infographics-mortality
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