Fabricated HMNPs with Size Approaching ~100 nm for MMC Loading and Sustained-release, as well as Labeling 99Tcm

Abstract

Herein, we developed the dual-function template method to fabricate hollow magnetic nano-spheres (denoted as HMNPs-Cn, n = 16, 18) with a mesoporous shell and hollow interior structure using alkyl chain trimethoxysilane templating. The microstructure of the HMNPs-Cn was investigated by means of XRD, FT-IR, EDS, SEM, TEM and N2-BET analyses. The shorter chain template directed formation of HMNPs-C16 with size of 119 nm, having disordered inkbottle type mesopores and saturation magnetization of 50.01 emu/g. It can be observed that, mitomycin C (MMC) loaded HMNPs-Cn hollow spheres showed a clear pH-dependent drug release behavior, having a higher release rate in acidic environments of pH 5.7. For the pH 5.7 and 7.4 release, the diffusion through HMNPs-Cn hollow spheres is the rate limiting step, the release kinetic for HMNPs-C16-MMC composites follows pseudo-first-order attributable to its special pore structure. For this reason the inner cavity of HMNPs-C16 could be labeled with radioisotope 99Tcm to study the magnetic targeting distribution of HMNPs-C16 in vivo, and its cytotoxicity against in vitro HeLa cells was also studied. These results indicate the potential of HMNPs-C16 in the magnetic targeted drug delivery system.