Magnetic Endoglin Aptamer Nanoprobe for Targeted Diagnosis of Solid Tumor.

Based on molecular targeting, magnetic resonance imaging (MRI) is an ideal noninvasive approach for tumor diagnosis. Construction of targeting probes to enhance the MRI efficacy has become a research hotspot recently. In this study, magnetic endoglin aptamer (mEND) imaging nanoprobes based on mEND-modified magnetic carboxymethyl chitosan (CMCS) nanoparticles (denoted mEND-Fe₃O₄@CMCS) were developed. The mEND-Fe₃O₄@CMCS naoprobe was prepared using mEND as the recognition molecule and Fe₃O₄@CMCS as the carrier to enhance the MRI efficacy of hepatocellular carcinoma (HCC). On the one hand, the CMCS self-assembled on the surface of Fe₃O₄ improved the biocompatibility and nontoxicity of magnetic nanoparticles. On the other hand, chemical groups provided by CMCS contributed to the modification of more aptamers. More importantly, the assembled aptamers significantly improved the probe targeting ability, thus enhancing the diagnosis efficacy of MRI of HCC. As a result, the average diameter and zeta potential of the nanoprobe was 87.15±1.66 nm and -31.9±0.5 mV, respectively. The MRI imaging result indicated that this probe effectively targeted neovascularization of mouse HCC and improved the imaging contrast of subcutaneous tumor in mice. Cytotoxicity and histological tests confirmed that the constructed probe possessed low toxicity. In conclusion, the mEND-Fe₃O₄@CMCS nanoprobe showed high targeting affinity, enhanced MRI effect and good biocompatibility. This study provides new MRI probes to target CD105 positive cells and is a promising candidate for HCC early diagnosis.