AC and DC magnetic softness enhanced dual-doped γ-Fe2O3 nanoparticles for highly efficient cancer theranostics

Abstract

• Dual-doped (Ni 0.6 Zn 0.4 )-γFe 2 O 3 SPNPs with simultaneously enhanced AC and DC magnetic softness (MSEγ-IO) were innovatively designed and developed. • MSEγ-IO SPNPs showed significantly enhanced both intrinsic loss power (ILP, ∼ 4.0 nH m 2 kg −1 ) and r 2 -relaxivity ( r 2 = 660.4 mM −1 s −1 ). • The significantly enhanced ILP and r 2 -relaxivity were primarily due to the enhanced AC, and DC magnetic softness dominantly controlled by the dual dopants, Ni 2+ , and Zn 2+ cations, respectively. • The evaluation of bio-feasibility and bioavailability demonstrated the promise for a highly efficient cancer theragnosis agent. “Theranostics” by magnetic nanofluid hyperthermia (MNFH) combined with T 2 -weighted MR contrast imaging (MRI) using superparamagnetic nanoparticles (SPNPs) has been drawn a huge attraction in nanomedicine. However, insufficient AC heating power at the biologically safe range of AC magnetic field ( H AC ) ( H appl < 190 Oe, f appl < 120 kHz) and unsatisfactorily low r 2 -relaxivity keep SPNPs challenging for cancer theranostics agent applications. Here, innovatively designed and developed AC and DC magnetic softness enhanced dual-doped (Ni 0.6 Zn 0.4 )-γFe 2 O 3 (MSEγ-IO) SPNPs with significantly enhanced both intrinsic loss power (ILP, ∼ 4.0 nH m 2 kg −1 ) at the H appl ⋅ f appl = 1.23×10 9 A m −1 s −1 and r 2 -relaxivity ( r 2 = 660.4 mM −1 s −1 ) are reported. The significantly enhanced ILP, and r 2 -relaxivity of dual-doped MSEγ-IO SPNPs were primarily attributed to the distinctly enhanced AC magnetic softness directly related to the H AC absorption and f appl resonance efficiency, and the DC magnetic softness dominantly controlled by the occupation and spatial distribution of Ni 2+ in O h vacancies sites, and Zn 2+ cations in T d sites of γ-Fe 2 O 3 , respectively. The biocompatibility and bioavailability experimentally evaluated by in-vitro and in-vivo studies demonstrated that the dual-doped MSEγ-IO SPNPs can be a promising candidate for highly efficient cancer theranostics agent for future nanomedicine.