Fabrication of functional hollow magnetic polymeric nanoparticles with controllable magnetic location.

Hollow magnetic polymeric particles (HoMPs) with controllable location of magnetic nanoparticles and functionality of polymeric double shell were fabricated by means of the facile soft templating method in one-pot. During the in situ miniemulsion polymerization, hexadecane, the Ostwald suppressing agent, acted as a soft template, which later formed a controllable void size. Adjusting ratio and polarity of monomers caused the difference in polymerization kinetics and phase separation, which resulted in HoMPs with two internal architectures, i.e., HoMPs-I with magnetic at the inner shell/void interface and HoMPs-II with magnetic-embedded shell. Both HoMPs-I and II contained high magnetic content (30-50%wt) with sufficient saturation magnetization (16-30 emu/g). With large void volume (>50%) and distinct shell polarity, either hydrophilic Rhodamine B or hydrophobic fluorescein isothiocyanate dye was selectively loaded. After functionalization with a cancer cell targeting ligand, folic acid (FA), the cellular uptake of HoMPs-FA in HeLa cell was improved with 100% cell viability and without cell destruction. This fabrication method provides a facile mean to tailor surface chemistry and architectures of hollow hybrid particles, which would be potentially used for efficient treatment of cancer tumors.