Based on cancer mortality statistics, the World Health Organization estimates that by 2030, approximately 17 million deaths annually will be attributable to cancer[1]. Despite how widespread cancer is, effective treatments for it have yet to be discovered. Nanotechnology has considerable potential for application in medicine to significantly improve cancer screening, diagnostics, and treatment. Magnetic nanoparticles belong among biomedical nanomaterials as they can be used for diagnostic and therapeutic purposes as they can be manipulated using a non-invasive external magnetic field[2][3]. Magnetic Resonance Imaging (MRI) is based on nuclear magnetic resonance and it is used as a diagnostic application for imaging of soft tissue. However, due to its low intrinsic contrast, it is difficult to distinguish between healthy tissue and tumors[4]. As opposed to Computerized Axial Tomography (CAT), Positron Emission Tomography (PET), and Single-Photon Emission Computed Tomography (SPECT), MRI is a non-invasive imaging technique as it does not use radioactive or ionizing radiation.
Using contrast agents (KS) and their magnetic relaxations, it is possible to increase the contrast between healthy tissue and tumors. Due to their magnetic properties, biocompatibility, good target site accumulation[3], and simple surface modification with ligands[5][6], such KS have opened up new approaches in MRI. Superparamagnetic iron oxide (Fe3O4) nanoparticles with a critical upper size limit of 25 nm[7] are suitably sensitive for MRI with T2-weighted imaging, but their clinical application is not widespread due to safety concerns. In order to prove that Fe3O4 KS are safe to use, we first synthesized and characterized them, and then prepared clinically approved carriers, i.e. synthetic liposomes, which are one of the most compatible carriers, for encapsulation. Using this method, we prepared magneto-liposomes. In addition to liposome encapsulation, we also encapsulated Fe3O4 nanoparticles in erythrocyte membranes, which are biocompatible and biodegradable. We compared the properties of synthesized magneto-erythrocyte membranes with the magneto-liposomes. The idea of using erythrocyte membranes to encapsulate Fe3O4 nanoparticles is to use the body’s own cells, thereby ensuring maximum biocompatibility of the encapsulation agent. Encapsulation of (5,0±0,4) nm Fe3O4 nanoparticles in liposomes or erythrocyte membranes showed a significant improvement of r2 relaxivity. The r2 value measured using a 9,4 T MRI scanner for non-encapsulated hydrophilic nanoparticles is 12±1 mM−1s−1, for magneto-liposomes 188±2 mM−1s−1, and for magnetic erythrocyte membranes 270±2 mM−1s−1. We compared the relaxivity analysis with MRI image capture and conducted a hemolysis study which showed suitable hemocompatibility properties of magnetic erythrocyte membranes. With the data we collected we can conclude that synthesized biocompatible magnetic nanoparticles with erythrocyte membranes or liposomer are suitable KS for T2-weighted imaging.
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