Abstrakt

Non-thermal electromagnetic fields to trigger On-Demand drug release from High-Tm Magnetoliposomes

Stefania Petralito

Magnetic nanoparticles with superparamagnetic properties have attracted increased attention for applications in biomedicine, as they exhibit a strong magnetization only when an external magnetic field is applied. Magnetoliposomes (MLs) are the combination of liposomes with encapsulated magnetic nanoparticles. These hybrid nanocarriers have been showing significant biomedical application possibilities. However, it is essential that nanoparticles exhibit superparamagnetism, this causes nanoparticles to become susceptible to strong magnetization. When the magnetic field is applied, they orient toward this field, but do not retain permanent magnetization in the absence of magnetic field. The magnetic properties of super paramagnetic iron oxide nanoparticles (SPIONs)-based magnetoliposomes allow for alternative therapies through magnetically controlled drug delivery and hyperthermia. In this way they can be viewed as trigger-responsive carriers as they have the potential to act as "remote switch" that can turn on or off the effects of the therapeutics, based on the presence or absence of the stimulus. Recently, a pilot study has demonstrated the feasibility of smart controlled delivery through a magnetic field with intensity significantly lower than the ones usually reported in literature. In this way, a controlled release has been obtained through a magneto-nanomechanical approach without any macroscopic temperature increase. Specifically, signals generated by non-thermal alternating magnetic fields (AMFs) or non-thermal pulsed electromagnetic fields (PEMFs) were applied to high-transition temperature magnetoliposomes (high-Tm MLs) entrapping hydrophilic SPIONs, proving to be interesting and promising stimuli-controlled drug delivery systems.