New Water-Soluble Magnetic Field-Induced Drug Delivery System Obtained Via Preferential Molecular Marriage over...

Nanomaterials that respond to stimuli are of considerable interest for drug delivery applications. Drug delivery has been a leading challenge when it comes to the externally triggered controlled release of hydrophobic drugs. The present paper describes a unique arrangement of polymers in a competitive environment derived from the dynamic self-sorting behavior of the hydrophobic chains of amphiphilic mPEG-PLLA and poly-l-lactic acid (PLLA)-coated iron oxide nanoparticles IONP@PLLA to achieve a core-shell structure in which the hydrophobic PLLA part acts as a dense core and poly(ethylene glycol) (PEG) as an uncrowded shell. By using irreversible covalent interactions created by hydrophobic polymer-functionalized IONPs, it was possible to selectively form socially self-sorted nanocarriers (SS-NCs) with a higher hydrophobic core than the hydrophilic shell over narcissistic self-sorted nanocarriers (NS-NCs), that is, homo-micelles of amphiphilic polymers. The higher hydrophobic core of SS-NCs is indeed helpful in achieving higher drug [doxorubicin (DOX)] loading and encapsulation efficiencies of around 17 and 90%, respectively, over 10.3 and 65.6% for NS-NCs. Furthermore, due to the presence of IONPs and the densely packed hydrophobic compartments, the controlled release of DOX was facilitated by direct magnetism and temperature stimulation when an alternating magnetic field (AMF) was applied. An appreciably higher rate of drug release (∼50%) than that without AMF (∼18%) was achieved under ambient conditions in 24 h. The present study, therefore, proposes a new drug delivery system that exceeds homo-micelles and adds an extra feature of manipulating drug release through magnetism and temperature, that is, hyperthermia.