Optimization of Tyrosine Kinase Inhibitor-Loaded Gold Nanoparticles for Stimuli-Triggered Antileukemic Drug Release.

Tyrosine kinase inhibitor (TKI) therapy is gaining attraction in advanced cancer therapeutics due to the ubiquity of kinases in cell survival and differentiation. Great progress was made in the past years in identifying tyrosine kinases that can function as valuable molecular targets and for the entrapment of their corresponding inhibitors in delivery compounds for triggered release. Herein we present a class of drug-delivery nanocompounds based on TKI Midostaurin-loaded gold nanoparticles that have the potential to be used as theranostic agents for the targeting of the FMS-like tyrosine kinase 3 (FLT3) in acute myeloid leukemia. We optimized the nanocompounds' formulation with loading efficiency in the 84-94% range and studied the drug release behavior in the presence of stimuli-responsive polymers. The therapeutic activity of MDS-loaded particles, superior to that of the free drug, was confirmed with toxicities depending on specific dosage ranges. No effect was observed on FLT3-negative cells or for the unloaded particles. Beyond druggability, we can track this type of nanocarrier inside biological structures as demonstrated via dark field microscopy. These properties might contribute to the facilitation of personalized drug dosage administration, critical for attaining a maximal therapeutic effect.