Fundamental Investigation On Tumor Targeting Novel MRI Nanoprobe Fe₂O₃@PDA-PEG-Affibody In Colorectal Cancer

Objective:To explore the feasibility of tumor-targeted Ferric Oxide Nanoparticle Fe2O3@PDA-PEG-Affibody could be used during the diagnosis and treatment of colorectal cancer mice modeds.Method:The superparamagnetic iron oxide nanoparticle?SPIO?as the core,the dopamine?PDA?shell absorbing near-infrared light?INR?,and the tumor-targeting polypeptide affinity Affibody were connected to construct a novel integrated targeted MRI contrast agent Fe₂O₃@PDA-PEG-Affibody,which was evaluated for its biocompatibility,magnetic resonance imaging?MRI?and photothermal therapy?PTT?experiments were performed on the tumor-bearing mice model of colorectal cancer respectively.The effect of photothermal therapy was evaluated by the manifestination of MRI images and the tumor volume curve.Results:A biocompatible nanotheranostic platform has been constructed on the basis of coating a near-infrared light?NIR?absorbing polydopamine?PDA?shell on oleic acid-capped superparamagnetic ferric oxide nanoparticle,which is termed as Fe2O3@PDA-PEG-Affibody.The integrates T2WI magnetic resonance imaging?MRI?,tumor targeting,and magnetic field?MF?enhanced photothermal therapy?PTT?functionalities into all-in-one system.The results show high negative contrast in MRI of colorectal cancer tumor bearing mouse with decreasing of 68%MRI signal,indicating that Fe₂O₃@PDA-PEG-Affibody can recognize tumor with high efficacy and specificity.Furthermore,high accumulation ratio and enhanced inhibition of tumor growth are achieved under near-infrared?NIR??808 nm?laser irritation with the aid of an external MF focus on the targeted tumor,resulting in completely eradicated mousebearing tumor without regrowth.Conclusion:The constructed Fe2O3@PDA-PEG-Affibody has negligible cytotoxicity and long-term in vivo toxicity and exhibits high accumulation in colorectal cancer tumor-bearing mice.More importantly,the enhanced enrichment of Fe₂O₃@PDA-PEG-Affibody.Throughmagnetic targeting makes photothermal ablation of tumor more efficient at a relative low dosage.This work provides us an efficient and effective pathway to fabricate a theranostic nanoparticle which has potential in the future precisely controlled cancer therapy.