Multifunctional nanoplatform for biomedical applications

Abstract

Working machinery in life is nanometric, thus, it is no wonder tliat the development of adequate nanotools would be very helpful in biomedical science. In this direction, the idea behind this work is to build a nanoplatform that can incorporate, in an easy way, multiple physical and biological functionalities. The core of the platform is an hydrophobic polymer that may be used as a matrix for the encapsulation of inorganic nanoparticles (magnetic, luminescent, radioactive, . . .). This matrix contains a Michael acceptor (or an acceptor) on its surface for functionalization. Organic bioactive molecules are attached to one end of a hydrophilic polymer (Le. PEG) terminated on a Michael acceptor (or a donor), and then they are anchored to the hydrophobic core by Michael addition. This system has the advantages of a clean synthesis (no by-products), mild conditions, and an easy and controlled multifunctionalization. The nanoplatform has been functionalized with radiochemical tracers (In111), luminescent dyes (fluorescein, rhodamine, lanthanide compounds), and magnetic nanoparticles, and therefore it can be a powerful tool in imaging. Besides, it has also been functionalized with a therapeutical drug, an antibody, and an optical thermometer made of lanthanide complexes. Health safety of tlhe system has been tested in cellular and in vivo assays. The nanoplatform is highly stable in biological fluids, shows low cell toxicity, high capacity of cell internalization, excellent hematocompatibility, and anticoagulation properties. It is shown that magnetic properties can be tuned up in the whole superparamagnetic range. Moreover, the system has shown excellent performance in magnetic resonance imaging and liyperthermia.