Fe<sub>3</sub>O<sub>4</sub> Nanoparticles Embedded in Pectin–Doxorubicin Composites as pH-Responsive Nanoplatforms for Tumor Diagnosis and Therapy by <i>T</i><sub>1</sub>-Weighted Magnetic Imaging
Yinghua Tao, Yucheng Li, Dandan Wei, Min Liang, Pengfei Ren, Jidong Dai, Tianzhu Zhang, Jiandu Lei, Peidang Liu
Abstract
Multifunctional nanomaterials with diagnostic and therapeutic capabilities offer promising customized nanomedicines for cancers. However, achieving good execution of these functions in vivo employing a single nanoframework remains challenging, and only a few of these magnetic nanocarriers have been validated for clinical use. In this study, based on biocompatibility and remarkable multifunctionalities, we describe a novel approach to synthesize small Fe3O4 nanoparticles conjugated with natural polysaccharide pectin and assembled into a pH-responsive T1-weighted magnetic resonance imaging contrast agent, Fe3O4@PD, for better chemotherapeutic efficacy. In vitro studies revealed that the conjugated doxorubicin (DOX) was quickly released in the tumor microenvironment by cleavage of the acid-sensitive acylhydrazone bond at a release rate of 89.72% and exerted a considerable inhibitory effect on breast cancer cells. In vivoT1-weighted images of mice showed that Fe3O4@PD displayed darkening to brightening contrast enhancement at tumor sites, and the relative signal-to-noise ratio of the tumor site reached its maximum (increased to about 2.27-fold) for distinguishing the normal and tumor tissues. Thus, this Fe3O4@PD-based system has the potential to be a multifunctional nanodrug delivery system, and as a smart theragnostic platform, it has broad application prospects in clinical and biological works, such as cell-based diagnostics and in vivo medication monitoring.