Aptamer-conjugated Mn3O4@SiO2 core–shell nanoprobes for targeted magnetic resonance imaging

Abstract

The objective of this study was to evaluate the targeted T1-magnetic resonance imaging (MRI), quantitative biodistribution and toxicity of aptamer (AS411) conjugated Mn3O4@SiO2 core-shell nanoprobes (NPs) in human cervical carcinoma tumor-bearing mice. The NPs were firstly prepared by encapsulating a hydrophobic Mn3O4 core within an amino functionalized silica shell. The fluorophore rhodamine (RB) was doped into the silica shell and the amphiphilic polymer poly(ethylene glycol) (PEG) was modified on the surface of the shell to improve its biocompatibility, then the aptamer AS411 was conjugated onto the end of the PEG chains as targeting ligands. The final NPs were abbreviated as Mn3O4@SiO2(RB)-PEG-Apt. By means of in vitro fluorescence confocal imaging and in vivo MRI, the NPs have been demonstrated to target cancer cells and prominent tumor aggregation effectively. The imaging results were further confirmed by a quantitative biodistribution study. In addition, histological, hematological and biochemistry analysis also proved the low toxicity of NPs in vivo. Our results showed the great potential of the Mn3O4@SiO2(RB)-PEG-Apt NPs could be used as a multifunctional nanoplatform for long-term targeted imaging and therapy of cancer.

Multifunctional Gadolinium-Doped Manganese Carbonate Nanoparticles for Targeted MR/Fluorescence Imaging of Tiny Brain Gliomas

“…4, 5 However, the occurrence of nephrogenic systemic fibrosis (NSF) related to Gd (III) ions restricts widespread application of Gd-based contrast agents in clinical practice. 6,7 Therefore, attention has shifted to alternative agents such as manganese (Mn)-based complexes [8][9][10][11] and nanoparticles (NPs), [12][13][14][15] which has produced encouraging results for both in vitro and in vivo MR imaging of cancer. [16][17][18] For instance, MnO NPs have been successfully used for T 1 -weighted MR imaging of metastatic brain tumors.…”

Aptamer-based biosensors for biomedical diagnostics

“…120 Aptamer-assisted MRI has also been reported with other magnetic nanoparticles or aptamers. 121,122 In another approach, a DNA aptamer-conjugated Gd 3+ complex was developed. Gadolinium compounds are widely used as MRI contrast agents, but they often lack specificity for metabolites.…”

Multifunctional hollow CaF2:Yb3+/Er3+/Mn2+-poly(2-Aminoethyl methacrylate) microspheres for Pt(IV) pro-drug delivery and tri-modal imaging

“…Small amounts of manganese are essential for human body and healthy. Mn 2þ ion has five unpaired d electrons and has been demonstrated as a useful T 1 MR imaging constant agents [56,58,59,75,76]. In our study, we can find that the longitudinal relaxivity (r 1 ) value of nanoparticles after ploymerization is 0.5033 mM À1 s À1 (Fig.…”