Towards hybrid biocompatible magnetic rHuman serum albumin-based nanoparticles: Use of ultra-small (CeL_n)^3/4+ cation-doped maghemite nanoparticles as functional shell

Human serum albumin (HSA) is a protein found in human blood. Over the last decade, HSA has been evaluated as a promising drug carrier. However, not being magnetic, HSA cannot be used for biomedical applications such as magnetic resonance imaging (MRI) and magnetic drug targeting. Therefore, subsequent composites building on iron oxide nanoparticles that are already used clinically as MRI contrast agents are extensively studied. Recently and in this context, innovative fully hydrophilic ultra-small CAN-stabilized maghemite ((CeL_n)^3/4+-γ-Fe₂O₃) nanoparticles have been readily fabricated. The present study discusses the design, fabrication, and characterization of a dual phase hybrid core (rHSA)-shell ((CeL_n)^3/4+-γ-Fe₂O₃ NPs) nanosystem. Quite importantly and in contrast to widely used encapsulation strategies, rHSA NP surface-attached (CeL_n)^3/4+-γ-Fe₂O₃ NPs enabled to exploit both rHSA (protein functionalities) and (CeL_n)^3/4+-γ-Fe₂O₃ NP surface functionalities (COOH and ligand L coordinative exchange) in addition to very effective MRI contrast capability due to optimal accessibility of H₂O molecules with the outer magnetic phase. Resulting hybrid nanoparticles might be used as a platform modular system for therapeutic (drug delivery system) and MR diagnostic purposes.