NANOPARTICLE FUNCTIONALIZATION STRATEGIES FOR ORAL DELIVERY EVALUATED BY BIOMAGNETIC TECHNIQUES

Magnetic nanoparticles (MNPs) have been a significant focus of study in recent years owing to their theranostic properties and their substantial potential for guided drug delivery. This capacity is attributed to the functionalization of their coating, which imparts unique characteristics in a biological environment. Currently, the primary route for nanoparticle administration is intravenous, which presents several barriers, including the necessity for a specialized setting and its nature as an invasive technique, alongside a higher risk of overdose compared to alternative routes such as oral administration. Consequently, investigating methods for the functionalization of nanoparticles for oral delivery is of paramount importance, as it introduces the possibility of a new administration route for both disease diagnosis and treatment. The objective of this work is, therefore, to synthesize polyethylene glycol (PEG)-coated magnetic nanoparticles for in vivo application and to evaluate their biodistribution using AC Biosusceptometry (ACB) and Electron Paramagnetic Resonance (EPR). To achieve this, PEG-coated nanoparticles will be synthesized, characterized, and subsequently administered to Wistar rats. The in vivo model will involve six rats, which will be fasted for 12 hours before receiving 1.5 ml of MNPs@PEG via gavage, with a 4-hour absorption period prior to euthanasia and the collection of target organs (spleen, liver, blood, kidney, and heart). To date, studies have been conducted on two rats, which exhibited a prominent magnetic signal in the kidneys when analyzed by ACB, indicating that the MNPs@PEG are being absorbed through the gastrointestinal tract. This finding was corroborated by EPR analysis, which detected a signal in all organs of interest. Although these results are positive, the sample size is not yet sufficient for a statistical analysis to conclusively confirm the findings. Therefore, while it is not yet possible to definitively infer that PEG-functionalized nanoparticles are being absorbed via the gastrointestinal tract, the preliminary results indicate a high probability that this is occurring.